Science.gov

Sample records for absolute model ages

  1. Age Dependent Absolute Plate and Plume Motion Modeling

    NASA Astrophysics Data System (ADS)

    Heaton, D. E.; Koppers, A. A. P.

    2015-12-01

    Current absolute plate motion (APM) models from 80 - 0 Ma are constrained by the location of mantle plume related hotspot seamounts, in particular those of the Hawaiian-Emperor and Louisville seamount trails. Originally the 'fixed' hotspot hypothesis was developed to explain past plate motion based on linear age progressive intra-plate volcanism. However, now that 'moving' hotspots are accepted, it is becoming clear that APM models need to be corrected for individual plume motion vectors. For older seamount trails that were active between roughly 50 and 80 Ma the APM models that use 'fixed' hotspots overestimate the measured age progression in those trails, while APM models corrected for 'moving' hotspots underestimate those age progressions. These mismatches are due to both a lack of reliable ages in the older portions of both the Hawaii and Louisville seamount trails and insufficient APM modeling constraints from other seamount trails in the Pacific Basin. Seamounts are difficult to sample and analyze because many are hydrothermally altered and have low potassium concentrations. New 40Ar/39Ar Age results from International Ocean Drilling Project (IODP) Expedition 330 Sites U1372 (n=18), U1375 (n=3), U1376 (n=15) and U1377 (n=7) aid in constraining the oldest end of the Louisville Seamount trail. A significant observation in this study is that the age range recovered in the drill cores match the range of ages that were acquired on dredging cruises at the same seamounts (e.g. Koppers et al., 2011). This is important for determining the inception age of a seamount. The sections recovered from IODP EXP 330 are in-situ volcanoclastic breccia and lava flows. Comparing the seismic interpretations of Louisville guyots (Contreras-Reyes et al., 2010), Holes U1372, U1373 and U1374 penetrated the extrusive and volcanoclastic sections of the seamount. The ages obtained are consistent over stratigraphic intervals >100-450 m thick, providing evidence that these seamounts

  2. Absolute model ages of mantled surfaces in Malea Planum and Utopia Planitia, Mars.

    NASA Astrophysics Data System (ADS)

    Willmes, M.; Hiesinger, H.; Reiss, D.; Zanetti, M.

    2009-04-01

    The surface of Mars is partially covered by a latitude-dependent ice-rich smooth mantle in the middle and high latitudes (±30-60°) [1, 2]. These deposits relate to changes in the obliquity of Mars which have led to major shifts in the Martian climate and repeated global episodes of deposition [3]. The deposits vary in thickness and are usually independent of local geology, topography and elevation. In this study we have determined absolute model ages for the mantled surface units in Utopia Planitia (northern hemisphere) and Malea Planum (southern hemisphere) using crater statistics [4]. These regions show a specific type of mantle degradation called scalloped terrain, and modelled crater retention ages of the easily eroded mantle in these regions reveal the time since the last resurfacing. Images from the High Resolution Imaging Science Experiment (HiRISE) (25-50 cm/pixel spatial resolution) on board the Mars Reconnaissance Orbiter (MRO) were analyzed, continuous areas of smooth mantle were mapped, and small, fresh, unmodified craters were counted. Both regions show degradation features of the mantle in varying degrees. The mantle in Utopia Planitia appears heavily modified by polygonal fractures and scalloped depressions [5]. Scalloped depressions are also found in Malea Planum, but the mantle appears much smoother and less modified by periglacial processes [5, 6]. The study areas totalled 722 km² in Utopia Planitia, and 296 km² in Malea Planum. Model ages for these regions were determined using the chronology function of Hartmann and Neukum [4] and the production function Ivanov [7]. The model ages show that the mantle unit for the area mapped in Utopia Planitia is 0.65 (+0.35/-0.41) to 2.9 (+0.69/-0.75) Myr old and Malea Planum is 3.0 (+1.5/-1.7) to 4.5 (+1.3/-1.4) Myr old, and that both regions represent very recent Amazonian terrain. This is also in agreement with the observed young degradation features described by [6, 8]. We acknowledge that the

  3. Passive absolute age and temperature history sensor

    SciTech Connect

    Robinson, Alex; Vianco, Paul T.

    2015-11-10

    A passive sensor for historic age and temperature sensing, including a first member formed of a first material, the first material being either a metal or a semiconductor material and a second member formed of a second material, the second material being either a metal or a semiconductor material. A surface of the second member is in contact with a surface of the first member such that, over time, the second material of the second member diffuses into the first material of the first member. The rate of diffusion for the second material to diffuse into the first material depends on a temperature of the passive sensor. One of the electrical conductance, the electrical capacitance, the electrical inductance, the optical transmission, the optical reflectance, or the crystalline structure of the passive sensor depends on the amount of the second material that has diffused into the first member.

  4. Urey: to measure the absolute age of Mars

    NASA Technical Reports Server (NTRS)

    Randolph, J. E.; Plescia, J.; Bar-Cohen, Y.; Bartlett, P.; Bickler, D.; Carlson, R.; Carr, G.; Fong, M.; Gronroos, H.; Guske, P. J.; Herring, M.; Javadi, H.; Johnson, D. W.; Larson, T.; Malaviarachchi, K.; Sherrit, S.; Stride, S.; Trebi-Ollennu, A.; Warwick, R.

    2003-01-01

    UREY, a proposed NASA Mars Scout mission will, for the first time, measure the absolute age of an identified igneous rock formation on Mars. By extension to relatively older and younger rock formations dated by remote sensing, these results will enable a new and better understanding of Martian geologic history.

  5. Uranium isotopic composition and absolute ages of Allende chondrules

    NASA Astrophysics Data System (ADS)

    Brennecka, G. A.; Budde, G.; Kleine, T.

    2015-11-01

    A handful of events, such as the condensation of refractory inclusions and the formation of chondrules, represent important stages in the formation and evolution of the early solar system and thus are critical to understanding its development. Compared to the refractory inclusions, chondrules appear to have a protracted period of formation that spans millions of years. As such, understanding chondrule formation requires a catalog of reliable ages, free from as many assumptions as possible. The Pb-Pb chronometer has this potential; however, because common individual chondrules have extremely low uranium contents, obtaining U-corrected Pb-Pb ages of individual chondrules is unrealistic in the vast majority of cases at this time. Thus, in order to obtain the most accurate 238U/235U ratio possible for chondrules, we separated and pooled thousands of individual chondrules from the Allende meteorite. In this work, we demonstrate that no discernible differences exist in the 238U/235U compositions between chondrule groups when separated by size and magnetic susceptibility, suggesting that no systematic U-isotope variation exists between groups of chondrules. Consequently, chondrules are likely to have a common 238U/235U ratio for any given meteorite. A weighted average of the six groups of chondrule separates from Allende results in a 238U/235U ratio of 137.786 ± 0.004 (±0.016 including propagated uncertainty on the U standard [Richter et al. 2010]). Although it is still possible that individual chondrules have significant U isotope variation within a given meteorite, this value represents our best estimate of the 238U/235U ratio for Allende chondrules and should be used for absolute dating of these objects, unless such chondrules can be measured individually.

  6. Absolute ages from crater statistics: Using radiometric ages of Martian samples for determining the Martian cratering chronology

    NASA Technical Reports Server (NTRS)

    Neukum, G.

    1988-01-01

    In the absence of dates derived from rock samples, impact crater frequencies are commonly used to date Martian surface units. All models for absolute dating rely on the lunar cratering chronology and on the validity of its extrapolation to Martian conditions. Starting from somewhat different lunar chronologies, rather different Martian cratering chronologies are found in the literature. Currently favored models are compared. The differences at old ages are significant, the differences at younger ages are considerable and give absolute ages for the same crater frequencies as different as a factor of 3. The total uncertainty could be much higher, though, since the ratio of lunar to Martian cratering rate which is of basic importance in the models is believed to be known no better than within a factor of 2. Thus, it is of crucial importance for understanding the the evolution of Mars and determining the sequence of events to establish an unambiguous Martian cratering chronology from crater statistics in combination with clean radiometric ages of returned Martian samples. For the dating goal, rocks should be as pristine as possible from a geologically simple area with a one-stage emplacement history of the local formation. A minimum of at least one highland site for old ages, two intermediate-aged sites, and one very young site is needed.

  7. Absolute Gravity Datum in the Age of Cold Atom Gravimeters

    NASA Astrophysics Data System (ADS)

    Childers, V. A.; Eckl, M. C.

    2014-12-01

    The international gravity datum is defined today by the International Gravity Standardization Net of 1971 (IGSN-71). The data supporting this network was measured in the 1950s and 60s using pendulum and spring-based gravimeter ties (plus some new ballistic absolute meters) to replace the prior protocol of referencing all gravity values to the earlier Potsdam value. Since this time, gravimeter technology has advanced significantly with the development and refinement of the FG-5 (the current standard of the industry) and again with the soon-to-be-available cold atom interferometric absolute gravimeters. This latest development is anticipated to provide improvement in the range of two orders of magnitude as compared to the measurement accuracy of technology utilized to develop ISGN-71. In this presentation, we will explore how the IGSN-71 might best be "modernized" given today's requirements and available instruments and resources. The National Geodetic Survey (NGS), along with other relevant US Government agencies, is concerned about establishing gravity control to establish and maintain high order geodetic networks as part of the nation's essential infrastructure. The need to modernize the nation's geodetic infrastructure was highlighted in "Precise Geodetic Infrastructure, National Requirements for a Shared Resource" National Academy of Science, 2010. The NGS mission, as dictated by Congress, is to establish and maintain the National Spatial Reference System, which includes gravity measurements. Absolute gravimeters measure the total gravity field directly and do not involve ties to other measurements. Periodic "intercomparisons" of multiple absolute gravimeters at reference gravity sites are used to constrain the behavior of the instruments to ensure that each would yield reasonably similar measurements of the same location (i.e. yield a sufficiently consistent datum when measured in disparate locales). New atomic interferometric gravimeters promise a significant

  8. A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Bell, Cameron P. M.; Mamajek, Eric E.; Naylor, Tim

    2015-11-01

    We present a self-consistent, absolute isochronal age scale for young ( ≲ 200 Myr), nearby ( ≲ 100 pc) moving groups in the solar neighbourhood based on homogeneous fitting of semi-empirical pre-main-sequence model isochrones using the τ2 maximum-likelihood fitting statistic of Naylor & Jeffries in the MV, V - J colour-magnitude diagram. The final adopted ages for the groups are as follows: 149^{+51}_{-19} {Myr} for the AB Dor moving group, 24 ± 3 Myr for the β Pic moving group (BPMG), 45^{+11}_{-7} {Myr} for the Carina association, 42^{+6}_{-4} {Myr} for the Columba association, 11 ± 3 Myr for the η Cha cluster, 45 ± 4 Myr for the Tucana-Horologium moving group (Tuc-Hor), 10 ± 3 Myr for the TW Hya association and 22^{+4}_{-3} {Myr} for the 32 Ori group. At this stage we are uncomfortable assigning a final, unambiguous age to the Argus association as our membership list for the association appears to suffer from a high level of contamination, and therefore it remains unclear whether these stars represent a single population of coeval stars. Our isochronal ages for both the BPMG and Tuc-Hor are consistent with recent lithium depletion boundary (LDB) ages, which unlike isochronal ages, are relatively insensitive to the choice of low-mass evolutionary models. This consistency between the isochronal and LDB ages instils confidence that our self-consistent, absolute age scale for young, nearby moving groups is robust, and hence we suggest that these ages be adopted for future studies of these groups. Software implementing the methods described in this study is available from http://www.astro.ex.ac.uk/people/timn/tau-squared/.

  9. Redefinition of the crater-density and absolute-age boundaries for the chronostratigraphic system of Mars

    USGS Publications Warehouse

    Werner, S.C.; Tanaka, K.L.

    2011-01-01

    For the boundaries of each chronostratigraphic epoch on Mars, we present systematically derived crater-size frequencies based on crater counts of geologic referent surfaces and three proposed " standard" crater size-frequency production distributions as defined by (a) a simple -2 power law, (b) Neukum and Ivanov, (c) Hartmann. In turn, these crater count values are converted to model-absolute ages based on the inferred cratering rate histories. We present a new boundary definition for the Late Hesperian-Early Amazonian transition. Our fitting of crater size-frequency distributions to the chronostratigraphic record of Mars permits the assignment of cumulative counts of craters down to 100. m, 1. km, 2. km, 5. km, and 16. km diameters to martian epochs. Due to differences in the " standard" crater size-frequency production distributions, a generalized crater-density-based definition to the chronostratigraphic system cannot be provided. For the diameter range used for the boundary definitions, the resulting model absolute age fits vary within 1.5% for a given set of production function and chronology model ages. Crater distributions translated to absolute ages utilizing different curve descriptions can result in absolute age differences exceeding 10%. ?? 2011 Elsevier Inc.

  10. Revisiting absolute and relative judgments in the WITNESS model.

    PubMed

    Fife, Dustin; Perry, Colton; Gronlund, Scott D

    2014-04-01

    The WITNESS model (Clark in Applied Cognitive Psychology 17:629-654, 2003) provides a theoretical framework with which to investigate the factors that contribute to eyewitness identification decisions. One key factor involves the contributions of absolute versus relative judgments. An absolute contribution is determined by the degree of match between an individual lineup member and memory for the perpetrator; a relative contribution involves the degree to which the best-matching lineup member is a better match to memory than the remaining lineup members. In WITNESS, the proportional contributions of relative versus absolute judgments are governed by the values of the decision weight parameters. We conducted an exploration of the WITNESS model's parameter space to determine the identifiability of these relative/absolute decision weight parameters, and compared the results to a restricted version of the model that does not vary the decision weight parameters. This exploration revealed that the decision weights in WITNESS are difficult to identify: Data often can be fit equally well by setting the decision weights to nearly any value and compensating with a criterion adjustment. Clark, Erickson, and Breneman (Law and Human Behavior 35:364-380, 2011) claimed to demonstrate a theoretical basis for the superiority of lineup decisions that are based on absolute contributions, but the relationship between the decision weights and the criterion weakens this claim. These findings necessitate reconsidering the role of the relative/absolute judgment distinction in eyewitness decision making. PMID:23943556

  11. A general relativistic model for free-fall absolute gravimeters

    NASA Astrophysics Data System (ADS)

    Tan, Yu-Jie; Shao, Cheng-Gang; Li, Jia; Hu, Zhong-Kun

    2016-04-01

    Although the relativistic manifestations of gravitational fields in gravimetry were first studied 40 years ago, the relativistic effects combined with free-fall absolute gravimeters have rarely been considered. In light of this, we present a general relativistic model for free-fall absolute gravimeters in a local-Fermi coordinates system, where we focus on effects related to the measuring devices: relativistic transverse Doppler effects, gravitational redshift effects and Earth’s rotation effects. Based on this model, a general relativistic expression of the measured gravity acceleration is obtained.

  12. Electroweak absolute, meta-, and thermal stability in neutrino mass models

    NASA Astrophysics Data System (ADS)

    Lindner, Manfred; Patel, Hiren H.; Radovčić, Branimir

    2016-04-01

    We analyze the stability of the electroweak vacuum in neutrino mass models containing right-handed neutrinos or fermionic isotriplets. In addition to considering absolute stability, we place limits on the Yukawa couplings of new fermions based on metastability and thermal stability in the early Universe. Our results reveal that the upper limits on the neutrino Yukawa couplings can change significantly when the top quark mass is allowed to vary within the experimental range of uncertainty in its determination.

  13. GeMS MCAO observations of the Galactic globular cluster NGC 2808: the absolute age

    NASA Astrophysics Data System (ADS)

    Massari, D.; Fiorentino, G.; McConnachie, A.; Bono, G.; Dall'Ora, M.; Ferraro, I.; Iannicola, G.; Stetson, P. B.; Turri, P.; Tolstoy, E.

    2016-02-01

    Context. Globular clusters are the oldest stellar systems in the Milky Way, and they probe the early epoch of the Galaxy formation. However, the uncertainties on their absolute age are still too large to soundly constrain how the Galactic structures have assembled. Aims: The aim of this work is to obtain an accurate estimate of the absolute age of the globular cluster NGC 2808 using deep IR data obtained with the multi-conjugate adaptive optics system operating at the Gemini South telescope (GeMS). Methods: This exquisite photometry, combined with that obtained in V and I-bands with HST, allowed us to detect the faint Main Sequence Knee feature in NGC 2808 colour magnitude diagram. The difference between this point and the main sequence turn-off is a good age estimator that provides ages with unprecedented accuracy. Results: We find that NGC 2808 has an age of t = 10.9 ± 0.7 (intrinsic) ±0.45 (metallicity term) Gyr. A possible contamination by He-enhanced population could make the cluster up to 0.25 Gyr older. Although this age estimate agrees with the age coming from the classical turn-off method (t = 11.0 Gyr), its uncertainty is a factor ~3 better, since it avoids systematics in reddening, distance assumptions, and photometric zero point determination. The final absolute age indicates that NGC 2808 is slightly younger than other Galactic globular clusters with similar metallicity. Tables of the photometry are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A51

  14. Revised Age Constraints on Absolute Age Limits for Mercury's Kuiperian and Mansurian Systems

    NASA Astrophysics Data System (ADS)

    Banks, Maria E.; Zhiyong, Xiao; Braden, Sarah E.; Marchi, Simone S.; Barlow, Nadine G.; Chapman, Clark R.; Fassett, Caleb I.

    2015-11-01

    On the basis of morphologically distinct basin and crater deposits, Mercury’s surface units have been subdivided into five time-stratigraphic systems (youngest to oldest): Kuiperian, Mansurian, Calorian, Tolstojan, and pre-Tolstojan. Approximate age limits were initially suggested for these systems on the basis of the lunar-derived impact-flux history. High-resolution and multi-band image data obtained by the MErcury Surface, Space ENviroment, GEochemistry, and Ranging (MESSENGER) spacecraft were used to catalogue fresh impact craters interpreted to have formed during the Mansurian and Kuiperian systems. Mansurian and Kuiperian craters are characterized as morphologically fresh with crisp morphologies, well-preserved rims, few or no superposed craters, continuous ejecta with radial lineaments, and well-defined secondary craters; Kuiperian craters have bright ray systems while Mansurian craters maintain fresh morphologies but no longer have discernable ray systems.The density of fresh craters in these datasets, along with the recent production and chronology function of Marchi et al. [2009], are used to estimate new limits for the boundaries of the two most recent of Mercury’s systems. Given the effects of strength and other parameters (such as density), we estimate a model age for the population of craters that have formed since the onset of the Mansurian of ~1.9 ±0.3 Gyr. Likewise we estimate a model age for the population of craters that have formed since the onset of the Kuiperian of ~300 ±40 Myr. A particularly good fit for the Mansurian crater size frequency distribution (SFD) was found for the NEO-derived crater distribution. The same is true for the Kuiperian SFD, although the fit is not as robust as for the Mansurian SFD.

  15. Absolute age of lunar regolith material from the Sea of Fertility

    NASA Technical Reports Server (NTRS)

    Vinogradov, A. P.; Artemov, Y. M.

    1974-01-01

    By averaging the absolute age of lunar regolith materials from the Sea of Fertility for the fine regolith fraction from the core zone V, an age of 4.65 10 to the 9th power + 0.4 10 to the 9th power years was obtained, employing as the primordial Sr-87/Sr-86 ratio 0.69884 (ADOR). Also close to this age value is the age estimate based on the Pb-207/Pb-206 ratio. Using the value 0.69898 (BABI) as a primordial Sr-87/Sr-86 ratio reduces the calculated age of the fine regolith fraction to 4.25 X 10 to the 9th power years. The fine fraction of lunar regolith from the Sea of Fertility is also characterized by a minimum addition of radiogenic Sr-87, a minimum Rb/Sr ratio, and a maximum K/Rb ratio compared with analogous lunar material from other points.

  16. Predicting Absolute Risk of Type 2 Diabetes Using Age and Waist Circumference Values in an Aboriginal Australian Community

    PubMed Central

    2015-01-01

    Objectives To predict in an Australian Aboriginal community, the 10-year absolute risk of type 2 diabetes associated with waist circumference and age on baseline examination. Method A sample of 803 diabetes-free adults (82.3% of the age-eligible population) from baseline data of participants collected from 1992 to 1998 were followed-up for up to 20 years till 2012. The Cox-proportional hazard model was used to estimate the effects of waist circumference and other risk factors, including age, smoking and alcohol consumption status, of males and females on prediction of type 2 diabetes, identified through subsequent hospitalisation data during the follow-up period. The Weibull regression model was used to calculate the absolute risk estimates of type 2 diabetes with waist circumference and age as predictors. Results Of 803 participants, 110 were recorded as having developed type 2 diabetes, in subsequent hospitalizations over a follow-up of 12633.4 person-years. Waist circumference was strongly associated with subsequent diagnosis of type 2 diabetes with P<0.0001 for both genders and remained statistically significant after adjusting for confounding factors. Hazard ratios of type 2 diabetes associated with 1 standard deviation increase in waist circumference were 1.7 (95%CI 1.3 to 2.2) for males and 2.1 (95%CI 1.7 to 2.6) for females. At 45 years of age with baseline waist circumference of 100 cm, a male had an absolute diabetic risk of 10.9%, while a female had a 14.3% risk of the disease. Conclusions The constructed model predicts the 10-year absolute diabetes risk in an Aboriginal Australian community. It is simple and easily understood and will help identify individuals at risk of diabetes in relation to waist circumference values. Our findings on the relationship between waist circumference and diabetes on gender will be useful for clinical consultation, public health education and establishing WC cut-off points for Aboriginal Australians. PMID:25876058

  17. Measured and modelled absolute gravity changes in Greenland

    NASA Astrophysics Data System (ADS)

    Nielsen, J. Emil; Forsberg, Rene; Strykowski, Gabriel

    2014-01-01

    In glaciated areas, the Earth is responding to the ongoing changes of the ice sheets, a response known as glacial isostatic adjustment (GIA). GIA can be investigated through observations of gravity change. For the ongoing assessment of the ice sheets mass balance, where satellite data are used, the study of GIA is important since it acts as an error source. GIA consists of three signals as seen by a gravimeter on the surface of the Earth. These signals are investigated in this study. The ICE-5G ice history and recently developed ice models of present day changes are used to model the gravity change in Greenland. The result is compared with the initial measurements of absolute gravity (AG) change at selected Greenland Network (GNET) sites.

  18. Problems determining relative and absolute ages using the small crater population

    NASA Astrophysics Data System (ADS)

    Xiao, Zhiyong; Strom, Robert G.

    2012-07-01

    The small crater populations (diameter smaller than 1 km) are widely used to date planetary surfaces. The reliability of small crater counts is tested by counting small craters at several young and old lunar surfaces, including Mare Nubium and craters Alphonsus, Tycho and Giordano Bruno. Based on high-resolution images from both the Lunar Reconnaissance Orbiter Camera and Kaguya Terrain Camera, small craters in two different diameter ranges are counted for each counting area. Large discrepancies exist in both the cumulative (absolute model ages) and relative plots for the two different size ranges of the same counting areas. The results indicate that dating planetary surfaces using small crater populations is highly unreliable because the contamination of secondaries may invalidate the results of small crater counts. A comparison of the size-frequency distributions of the small crater populations and impact ejected boulders around fresh lunar craters shows the same upturn as typical martian secondaries, which supports the argument that secondaries dominate the small crater populations on the Moon and Mars. Also, the size-frequency distributions of small rayed lunar and martian craters of probable primary origin are similar to that of the Population 2 craters on the inner Solar System bodies post-dating Late Heavy Bombardment. Dating planetary surfaces using the small crater populations requires the separation of primaries from secondaries which is extremely difficult. The results also show that other factors, such as different target properties and the subjective identification of impact craters by different crater counters, may also affect crater counting results. We suggest that dating planetary surfaces using small crater populations should be with highly cautious.

  19. Accurate radiocarbon age estimation using "early" measurements: a new approach to reconstructing the Paleolithic absolute chronology

    NASA Astrophysics Data System (ADS)

    Omori, Takayuki; Sano, Katsuhiro; Yoneda, Minoru

    2014-05-01

    This paper presents new correction approaches for "early" radiocarbon ages to reconstruct the Paleolithic absolute chronology. In order to discuss time-space distribution about the replacement of archaic humans, including Neanderthals in Europe, by the modern humans, a massive data, which covers a wide-area, would be needed. Today, some radiocarbon databases focused on the Paleolithic have been published and used for chronological studies. From a viewpoint of current analytical technology, however, the any database have unreliable results that make interpretation of radiocarbon dates difficult. Most of these unreliable ages had been published in the early days of radiocarbon analysis. In recent years, new analytical methods to determine highly-accurate dates have been developed. Ultrafiltration and ABOx-SC methods, as new sample pretreatments for bone and charcoal respectively, have attracted attention because they could remove imperceptible contaminates and derive reliable accurately ages. In order to evaluate the reliability of "early" data, we investigated the differences and variabilities of radiocarbon ages on different pretreatments, and attempted to develop correction functions for the assessment of the reliability. It can be expected that reliability of the corrected age is increased and the age applied to chronological research together with recent ages. Here, we introduce the methodological frameworks and archaeological applications.

  20. Lunar eclipse photometry: absolute luminance measurements and modeling.

    PubMed

    Hernitschek, Nina; Schmidt, Elmar; Vollmer, Michael

    2008-12-01

    The Moon's time-dependent luminance was determined during the 9 February 1990 and 3 March 2007 total lunar eclipses by using calibrated, industry standard photometers. After the results were corrected to unit air mass and to standard distances for both Moon and Sun, an absolute calibration was accomplished by using the Sun's known luminance and a pre-eclipse lunar albedo of approximately 13.5%. The measured minimum level of brightness in the total phase of both eclipses was relatively high, namely -3.32 m(vis) and -1.7 m(vis), which hints at the absence of pronounced stratospheric aerosol. The light curves were modeled in such a way as to let the Moon move through an artificial Earth shadow composed of a multitude of disk and ring zones, containing a relative luminance data set from an atmospheric radiative transfer calculation. PMID:19037352

  1. Reduced Haemodynamic Response in the Ageing Visual Cortex Measured by Absolute fNIRS

    PubMed Central

    Ward, Laura McKernan; Aitchison, Ross Thomas; Tawse, Melisa; Simmers, Anita Jane; Shahani, Uma

    2015-01-01

    The effect of healthy ageing on visual cortical activation is still to be fully explored. This study aimed to elucidate whether the haemodynamic response (HDR) of the visual cortex altered as a result of ageing. Visually normal (healthy) participants were presented with a simple visual stimulus (reversing checkerboard). Full optometric screening was implemented to identify two age groups: younger adults (n = 12, mean age 21) and older adults (n = 13, mean age 71). Frequency-domain Multi-distance (FD-MD) functional Near-Infrared Spectroscopy (fNIRS) was used to measure absolute changes in oxygenated [HbO] and deoxygenated [HbR] haemoglobin concentrations in the occipital cortices. Utilising a slow event-related design, subjects viewed a full field reversing checkerboard with contrast and check size manipulations (15 and 30 minutes of arc, 50% and 100% contrast). Both groups showed the characteristic response of increased [HbO] and decreased [HbR] during stimulus presentation. However, older adults produced a more varied HDR and often had comparable levels of [HbO] and [HbR] during both stimulus presentation and baseline resting state. Younger adults had significantly greater concentrations of both [HbO] and [HbR] in every investigation regardless of the type of stimulus displayed (p<0.05). The average variance associated with this age-related effect for [HbO] was 88% and [HbR] 91%. Passive viewing of a visual stimulus, without any cognitive input, showed a marked age-related decline in the cortical HDR. Moreover, regardless of stimulus parameters such as check size, the HDR was characterised by age. In concurrence with present neuroimaging literature, we conclude that the visual HDR decreases as healthy ageing proceeds. PMID:25909849

  2. Mathematical Model for Absolute Magnetic Measuring Systems in Industrial Applications

    NASA Astrophysics Data System (ADS)

    Fügenschuh, Armin; Fügenschuh, Marzena; Ludszuweit, Marina; Mojsic, Aleksandar; Sokół, Joanna

    2015-09-01

    Scales for measuring systems are either based on incremental or absolute measuring methods. Incremental scales need to initialize a measurement cycle at a reference point. From there, the position is computed by counting increments of a periodic graduation. Absolute methods do not need reference points, since the position can be read directly from the scale. The positions on the complete scales are encoded using two incremental tracks with different graduation. We present a new method for absolute measuring using only one track for position encoding up to micrometre range. Instead of the common perpendicular magnetic areas, we use a pattern of trapezoidal magnetic areas, to store more complex information. For positioning, we use the magnetic field where every position is characterized by a set of values measured by a hall sensor array. We implement a method for reconstruction of absolute positions from the set of unique measured values. We compare two patterns with respect to uniqueness, accuracy, stability and robustness of positioning. We discuss how stability and robustness are influenced by different errors during the measurement in real applications and how those errors can be compensated.

  3. Is an absolute level of cortical beta suppression required for proper movement? Magnetoencephalographic evidence from healthy aging.

    PubMed

    Heinrichs-Graham, Elizabeth; Wilson, Tony W

    2016-07-01

    Previous research has connected a specific pattern of beta oscillatory activity to proper motor execution, but no study to date has directly examined how resting beta levels affect motor-related beta oscillatory activity in the motor cortex. Understanding this relationship is imperative to determining the basic mechanisms of motor control, as well as the impact of pathological beta oscillations on movement execution. In the current study, we used magnetoencephalography (MEG) and a complex movement paradigm to quantify resting beta activity and movement-related beta oscillations in the context of healthy aging. We chose healthy aging as a model because preliminary evidence suggests that beta activity is elevated in older adults, and thus by examining older and younger adults we were able to naturally vary resting beta levels. To this end, healthy younger and older participants were recorded during motor performance and at rest. Using beamforming, we imaged the peri-movement beta event-related desynchronization (ERD) and extracted virtual sensors from the peak voxels, which enabled absolute and relative beta power to be assessed. Interestingly, absolute beta power during the pre-movement baseline was much stronger in older relative to younger adults, and older adults also exhibited proportionally large beta desynchronization (ERD) responses during motor planning and execution compared to younger adults. Crucially, we found a significant relationship between spontaneous (resting) beta power and beta ERD magnitude in both primary motor cortices, above and beyond the effects of age. A similar link was found between beta ERD magnitude and movement duration. These findings suggest a direct linkage between beta reduction during movement and spontaneous activity in the motor cortex, such that as spontaneous beta power increases, a greater reduction in beta activity is required to execute movement. We propose that, on an individual level, the primary motor cortices have an

  4. Stratigraphy, structure, absolute age, and paleontology of the upper Pleistocene deposits at Sankaty Head, Nantucket Island, Massachusetts

    USGS Publications Warehouse

    Oldale, Robert N.; Valentine, Page C.; Cronin, T. M.; Spiker, E. C.; Blackwelder, B. W.; Belknap, D.F.; Wehmiller, J. F.; Szabo, B. J.

    1982-01-01

    The Sankaty Head cliff exposes drift of at least two glaciations and interglacial marine deposits. Radiocarbon, amino-acid- racemization, and uranium-thorium analyses were used to determine the absolute ages of the beds. The results indicate that 1) the Sankaty Sand correlates with oxygen-isotope stage 5 (Sangamonian), 2) the underlying drift is older than stage 5 (Illinoian or older) , and 3) the overlying drift is Wisconsinan in age. -from Authors

  5. Using peripheral smear review, age and absolute lymphocyte count as predictors of abnormal peripheral blood lymphocytoses diagnosed by flow cytometry.

    PubMed

    Andrews, Jared M; Cruser, Dan L; Myers, Jerome B; Fernelius, Colby A; Holm, Mitchel T; Waldner, Dale L

    2008-09-01

    Absolute lymphocytosis in the elderly raises the possibility of malignancy and generally warrants further investigation. To better correlate clinical variables with the frequency of neoplastic lymphoid processes in this population, we retrospectively reviewed archived flow cytometric analyses from peripheral blood specimens on patients of 50 years of age and older that had been deemed suspicious for a lymphoproliferative process after peripheral smear review. Age, absolute lymphocyte count (ALC), white blood cell count and relative lymphocyte count were correlated with the results of flow cytometry. Of 71 total cases, 42 (59%) had an abnormal immunophenotype. Independent variables that showed significant differences between normal and abnormal immunophenotype were mean age (p = 0.001) and ALC (p = 0.0032). We combined age and absolute lymphocyte count variables to look for the best possible cutoff values to predict the likelihood of an abnormal immunophenotype. ALC cutoff values of >or=4 x 10(9) cells/L for patients over 67 years of age, and >6.7 x 10(9) cells/L for patients between 50 and 67 years of age, had a high sensitivity for detecting an abnormal immunophenotype. PMID:18798107

  6. The Relative and Absolute Ages of Old Globular Clusters in the LCDM Framework

    NASA Astrophysics Data System (ADS)

    Trenti, Michele; Padoan, Paolo; Jimenez, Raul

    2015-08-01

    Old globular clusters (GCs) in the Milky Way have ages of about 13 Gyr, placing their formation time in the reionization epoch. We propose a novel scenario for the formation of these systems based on the merger of two or more atomic cooling halos at high redshift (z\\gt 6). First-generation stars are formed as an intense burst in the center of a minihalo that grows above the threshold for hydrogen cooling (halo mass {M}{{h}}∼ {10}8 {M}ȯ ) by undergoing a major merger within its cooling timescale (∼150 Myr). Subsequent minor mergers and sustained gas infall bring a new supply of pristine gas to the halo center, creating conditions that can trigger new episodes of star formation. The dark-matter halo around the GC is then stripped during assembly of the host-galaxy halo. Minihalo merging is efficient only in a short redshift window, set by the {{Λ }}{CDM} parameters, allowing us to make a strong prediction on the age distribution for old GCs. From cosmological simulations, we derive an average merging redshift < z> =9 and a narrow distribution {{Δ }}z=2, implying average GC age < {t}{age}> =13.0+/- 0.2 {Gyr} including ∼0.2 Gyr of star formation delay. Qualitatively, our scenario reproduces other general old GC properties (characteristic masses and number of objects, metallicity versus galactocentric radius anticorrelation, radial distribution), but unlike age, these generally depend on details of baryonic physics. In addition to improved age measurements, direct validation of the model at z∼ 10 may be within reach with ultradeep gravitationally lensed observations with the James Webb Space Telescope.

  7. Derivation of Absolute Model Ages for Lunar Lobate Scarps

    NASA Astrophysics Data System (ADS)

    van der Bogert, C. H.; Hiesinger, H.; Banks, M. E.; Watters, T. R.; Robinson, M. S.

    2012-03-01

    Crater size-frequency distribution measurements indicate that the Mandel'shtam and Lee-Lincoln scarps were active as recently as ~91 Ma and ~75 Ma, respectively. These results confirm that lobate scarps are some of the youngest features on the Moon.

  8. Relative and Absolute Fit Evaluation in Cognitive Diagnosis Modeling

    ERIC Educational Resources Information Center

    Chen, Jinsong; de la Torre, Jimmy; Zhang, Zao

    2013-01-01

    As with any psychometric models, the validity of inferences from cognitive diagnosis models (CDMs) determines the extent to which these models can be useful. For inferences from CDMs to be valid, it is crucial that the fit of the model to the data is ascertained. Based on a simulation study, this study investigated the sensitivity of various fit…

  9. Ridge-spotting: A new test for Pacific absolute plate motion models

    NASA Astrophysics Data System (ADS)

    Wessel, Paul; Müller, R. Dietmar

    2016-06-01

    Relative plate motions provide high-resolution descriptions of motions of plates relative to other plates. Yet geodynamically, motions of plates relative to the mantle are required since such motions can be attributed to forces (e.g., slab pull and ridge push) acting upon the plates. Various reference frames have been proposed, such as the hot spot reference frame, to link plate motions to a mantle framework. Unfortunately, both accuracy and precision of absolute plate motion models lag behind those of relative plate motion models. Consequently, it is paramount to use relative plate motions in improving our understanding of absolute plate motions. A new technique called "ridge-spotting" combines absolute and relative plate motions and examines the viability of proposed absolute plate motion models. We test the method on six published Pacific absolute plate motions models, including fixed and moving hot spot models as well as a geodynamically derived model. Ridge-spotting reconstructs the Pacific-Farallon and Pacific-Antarctica ridge systems over the last 80 Myr. All six absolute plate motion models predict large amounts of northward migration and monotonic clockwise rotation for the Pacific-Farallon ridge. A geodynamic implication of our ridge migration predictions is that the suggestion that the Pacific-Farallon ridge may have been pinned by a large mantle upwelling is not supported. Unexpected or erratic ridge behaviors may be tied to limitations in the models themselves or (for Indo-Atlantic models) discrepancies in the plate circuits used to project models into the Pacific realm. Ridge-spotting is promising and will be extended to include more plates and other ocean basins.

  10. Two-stage model of African absolute motion during the last 30 million years

    NASA Astrophysics Data System (ADS)

    Pollitz, Fred F.

    1991-07-01

    The absolute motion of Africa (relative to the hotspots) for the past 30 My is modeled with two Euler vectors, with a change occurring at 6 Ma. Because of the high sensitivity of African absolute motions to errors in the absolute motions of the North America and Pacific plates, both the pre-6 Ma and post-6 Ma African absolute motions are determined simultaneously with North America and Pacific absolute motions for various epochs. Geologic data from the northern Atlantic and hotspot tracks from the African plate are used to augment previous data sets for the North America and Pacific plates. The difference between the pre-6 Ma and post-6 Ma absolute plate motions may be represented as a counterclockwise rotation about a pole at 48 °S, 84 °E, with angular velocity 0.085 °/My. This change is supported by geologic evidence along a large portion of the African plate boundary, including the Red Sea and Gulf of Aden spreading systems, the Alpine deformation zone, and the central and southern mid-Atlantic Ridge. Although the change is modeled as one abrupt transition at 6 Ma, it was most likely a gradual change spanning the period 8-4 Ma. As a likely mechanism for the change, we favor strong asthenospheric return flow from the Afar hotspot towards the southwest; this could produce the uniform southwesterly shift in absolute motion which we have inferred as well as provide a mechanism for the opening of the East African Rift. Comparing the absolute motions of the North America and Pacific plates with earlier estimates, the pole positions are revised by up to 5° and the angular velocities are decreased by 10-20%.

  11. Towards an absolute chronology for the Aegean iron age: new radiocarbon dates from Lefkandi, Kalapodi and Corinth.

    PubMed

    Toffolo, Michael B; Fantalkin, Alexander; Lemos, Irene S; Felsch, Rainer C S; Niemeier, Wolf-Dietrich; Sanders, Guy D R; Finkelstein, Israel; Boaretto, Elisabetta

    2013-01-01

    The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8(th) century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11(th) century BCE according to the Conventional Aegean Chronology and in the late 12(th) century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11(th) century BCE. PMID:24386150

  12. A model for predicting individuals' absolute risk of esophageal adenocarcinoma: Moving toward tailored screening and prevention.

    PubMed

    Xie, Shao-Hua; Lagergren, Jesper

    2016-06-15

    Esophageal adenocarcinoma (EAC) is characterized by rapidly increasing incidence and poor prognosis, stressing the need for preventive and early detection strategies. We used data from a nationwide population-based case-control study, which included 189 incident cases of EAC and 820 age- and sex-matched control participants, from 1995 through 1997 in Sweden. We developed risk prediction models based on unconditional logistic regression. Candidate predictors included established and readily identifiable risk factors for EAC. The performance of model was assessed by the area under receiver operating characteristic curve (AUC) with cross-validation. The final model could explain 94% of all case patients with EAC (94% population attributable risk) and included terms for gastro-esophageal reflux symptoms or use of antireflux medication, body mass index (BMI), tobacco smoking, duration of living with a partner, previous diagnoses of esophagitis and diaphragmatic hernia and previous surgery for esophagitis, diaphragmatic hernia or severe reflux or gastric or duodenal ulcer. The AUC was 0.84 (95% confidence interval [CI] 0.81-0.87) and slightly lower after cross-validation. A simpler model, based only on reflux symptoms or use of antireflux medication, BMI and tobacco smoking could explain 91% of the case patients with EAC and had an AUC of 0.82 (95% CI 0.78-0.85). These EAC prediction models showed good discriminative accuracy, but need to be validated in other populations. These models have the potential for future use in identifying individuals with high absolute risk of EAC in the population, who may be considered for endoscopic screening and targeted prevention. PMID:26756848

  13. Insights from fossil coral U-Th age data from the Last Interglacial: Implications for seawater U-isotope composition and interpretation of absolute ages

    NASA Astrophysics Data System (ADS)

    Dutton, A.; Esat, T. M.

    2011-12-01

    significantly higher than that of modern seawater at sites around the globe, raising the possibility that seawater compositions during the Last Interglacial were also correspondingly higher. Unfortunately, without the traditional U-isotope diagenetic screening criterion it remains difficult to separate out 'altered' corals versus 'unaltered' corals; hence interpretation of the distribution of initial [234U/238U] in this Last Interglacial database requires assumptions about the effects of open-system diagenesis on this distribution. The adopted seawater [234U/238U] value for screening closed-system ages or for calculating ages using an open-system model will ultimately have an effect on the interpretation of the absolute age of the coral(s) in question. Adopting a higher seawater [234U/238U] value than modern seawater will result in an older interpreted age than for the scenario where the modern seawater value is adopted. This observation highlights the need to better characterize past uranium isotope variability in the oceans as we seek to provide increasingly stringent chronological constraints on past sea level change.

  14. Constraint on Absolute Accuracy of Metacomprehension Assessments: The Anchoring and Adjustment Model vs. the Standards Model

    ERIC Educational Resources Information Center

    Kwon, Heekyung

    2011-01-01

    The objective of this study is to provide a systematic account of three typical phenomena surrounding absolute accuracy of metacomprehension assessments: (1) the absolute accuracy of predictions is typically quite low; (2) there exist individual differences in absolute accuracy of predictions as a function of reading skill; and (3) postdictions…

  15. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  16. New identification method for Hammerstein models based on approximate least absolute deviation

    NASA Astrophysics Data System (ADS)

    Xu, Bao-Chang; Zhang, Ying-Dan

    2016-07-01

    Disorder and peak noises or large disturbances can deteriorate the identification effects of Hammerstein non-linear models when using the least-square (LS) method. The least absolute deviation technique can be used to resolve this problem; however, its absolute value cannot meet the need of differentiability required by most algorithms. To improve robustness and resolve the non-differentiable problem, an approximate least absolute deviation (ALAD) objective function is established by introducing a deterministic function that exhibits the characteristics of absolute value under certain situations. A new identification method for Hammerstein models based on ALAD is thus developed in this paper. The basic idea of this method is to apply the stochastic approximation theory in the process of deriving the recursive equations. After identifying the parameter matrix of the Hammerstein model via the new algorithm, the product terms in the matrix are separated by calculating the average values. Finally, algorithm convergence is proven by applying the ordinary differential equation method. The proposed algorithm has a better robustness as compared to other LS methods, particularly when abnormal points exist in the measured data. Furthermore, the proposed algorithm is easier to apply and converges faster. The simulation results demonstrate the efficacy of the proposed algorithm.

  17. The Absolute Age of the Globular Cluster M15 Using Near-infrared Adaptive Optics Images from PISCES/LBT.

    NASA Astrophysics Data System (ADS)

    Monelli, M.; Testa, V.; Bono, G.; Ferraro, I.; Iannicola, G.; Fiorentino, G.; Arcidiacono, C.; Massari, D.; Boutsia, K.; Briguglio, R.; Busoni, L.; Carini, R.; Close, L.; Cresci, G.; Esposito, S.; Fini, L.; Fumana, M.; Guerra, J. C.; Hill, J.; Kulesa, C.; Mannucci, F.; McCarthy, D.; Pinna, E.; Puglisi, A.; Quiros-Pacheco, F.; Ragazzoni, R.; Riccardi, A.; Skemer, A.; Xompero, M.

    2015-10-01

    We present deep near-infrared J, {K}{{s}} photometry of the old, metal-poor Galactic globular cluster M15 obtained with images collected with the LUCI1 and PISCES cameras available at the Large Binocular Telescope (LBT). We show how the use of First Light Adaptive Optics (FLAO) system coupled with the PISCES camera allows us to improve the limiting magnitude by ˜2 mag in {K}{{s}}. By analyzing archival Hubble Space Telescope data, we demonstrate that the quality of the LBT/PISCES color-magnitude diagram is fully comparable with analogous space-based data. The smaller field of view is balanced by the shorter exposure time required to reach a similar photometric limit. We investigated the absolute age of M15 by means of two methods: (i) by determining the age from the position of the main-sequence turnoff (MSTO), and (ii) by the magnitude difference between the MSTO and the well-defined knee detected along the faint portion of the MS. We derive consistent values of the absolute age of M15, that is, 12.9 ± 2.6 Gyr and 13.3 ± 1.1 Gyr, respectively. Observations were carried out using the Large Binocular Telescope at Mount Graham, AZ. The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are the University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; the Ohio State University; and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota, and University of Virginia.

  18. A simple model explaining super-resolution in absolute optical instruments

    NASA Astrophysics Data System (ADS)

    Leonhardt, Ulf; Sahebdivan, Sahar; Kogan, Alex; Tyc, Tomáš

    2015-05-01

    We develop a simple, one-dimensional model for super-resolution in absolute optical instruments that is able to describe the interplay between sources and detectors. Our model explains the subwavelength sensitivity of a point detector to a point source reported in previous computer simulations and experiments (Miñano 2011 New J. Phys.13 125009; Miñano 2014 New J. Phys.16 033015).

  19. THE DYNAMICAL DISTANCE, RR LYRAE ABSOLUTE MAGNITUDE, AND AGE OF THE GLOBULAR CLUSTER NGC 6266

    SciTech Connect

    McNamara, Bernard J.; McKeever, Jean E-mail: jeanm12@nmsu.edu

    2011-11-15

    The internal proper motion dispersion of NGC 6266 was measured using Hubble Space Telescope Wide Field Planetary Camera 2 images with an epoch difference of eight years. The dispersion was found to be 0.041 {+-} 0.001 arcsec century{sup -1}. This value was then equated to the cluster's radial velocity dispersion of 13.7 {+-} 1.1 km s{sup -1} to yield a distance to NGC 6266 of 7054 {+-} 583 pc. Based on this distance we find that the NGC 6266 RR Lyrae stars have M{sub V} = 0.51 {+-} 0.18 mag. This magnitude is in good agreement with that predicted by the M{sub V} versus [Fe/H] relation found by Benedict et al. Using an average [Fe/H] of -1.25 for NGC 6266, their relation predicts M{sub V} = 0.49 {+-} 0.06. Based on the RR Lyrae M{sub V} versus age relation determined by Chaboyer et al., we estimate that NGC 6266 has an age of 11.4 {+-} 2.2 Gyr.

  20. Modelling and measurement of the absolute level of power radiated by antenna integrated THz UTC photodiodes.

    PubMed

    Natrella, Michele; Liu, Chin-Pang; Graham, Chris; van Dijk, Frederic; Liu, Huiyun; Renaud, Cyril C; Seeds, Alwyn J

    2016-05-30

    We determine the output impedance of uni-travelling carrier (UTC) photodiodes at frequencies up to 400 GHz by performing, for the first time, 3D full-wave modelling of detailed UTC photodiode structures. In addition, we demonstrate the importance of the UTC impedance evaluation, by using it in the prediction of the absolute power radiated by an antenna integrated UTC, over a broad frequency range and confirming the predictions by experimental measurements up to 185 GHz. This is done by means of 3D full-wave modelling and is only possible since the source (UTC) to antenna impedance match is properly taken into account. We also show that, when the UTC-to-antenna coupling efficiency is modelled using the classical junction-capacitance/series-resistance concept, calculated and measured levels of absolute radiated power are in substantial disagreement, and the maximum radiated power is overestimated by a factor of almost 7 dB. The ability to calculate the absolute emitted power correctly enables the radiated power to be maximised through optimisation of the UTC-to-antenna impedance match. PMID:27410104

  1. Time-series modeling and prediction of global monthly absolute temperature for environmental decision making

    NASA Astrophysics Data System (ADS)

    Ye, Liming; Yang, Guixia; Van Ranst, Eric; Tang, Huajun

    2013-03-01

    A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochastic combined (DSC) approach. Although the development of the framework was based on the characterization of the variation patterns of a global dataset, the methodology could be applied to any monthly absolute temperature record. Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal, involving polynomial functions and the Fourier method, respectively, while stochastic processes were employed to account for any remaining patterns in the temperature signal, involving seasonal autoregressive integrated moving average (SARIMA) models. A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years. The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors, suggesting that DSC models, when coupled with other ecoenvironmental models, can be used as a supplemental tool for short-term (˜10-year) environmental planning and decision making.

  2. The Impact of Different Absolute Solar Irradiance Values on Current Climate Model Simulations

    NASA Technical Reports Server (NTRS)

    Rind, David H.; Lean, Judith L.; Jonas, Jeffrey

    2014-01-01

    Simulations of the preindustrial and doubled CO2 climates are made with the GISS Global Climate Middle Atmosphere Model 3 using two different estimates of the absolute solar irradiance value: a higher value measured by solar radiometers in the 1990s and a lower value measured recently by the Solar Radiation and Climate Experiment. Each of the model simulations is adjusted to achieve global energy balance; without this adjustment the difference in irradiance produces a global temperature change of 0.48C, comparable to the cooling estimated for the Maunder Minimum. The results indicate that by altering cloud cover the model properly compensates for the different absolute solar irradiance values on a global level when simulating both preindustrial and doubled CO2 climates. On a regional level, the preindustrial climate simulations and the patterns of change with doubled CO2 concentrations are again remarkably similar, but there are some differences. Using a higher absolute solar irradiance value and the requisite cloud cover affects the model's depictions of high-latitude surface air temperature, sea level pressure, and stratospheric ozone, as well as tropical precipitation. In the climate change experiments it leads to an underestimation of North Atlantic warming, reduced precipitation in the tropical western Pacific, and smaller total ozone growth at high northern latitudes. Although significant, these differences are typically modest compared with the magnitude of the regional changes expected for doubled greenhouse gas concentrations. Nevertheless, the model simulations demonstrate that achieving the highest possible fidelity when simulating regional climate change requires that climate models use as input the most accurate (lower) solar irradiance value.

  3. Absolute stability and synchronization in neural field models with transmission delays

    NASA Astrophysics Data System (ADS)

    Kao, Chiu-Yen; Shih, Chih-Wen; Wu, Chang-Hong

    2016-08-01

    Neural fields model macroscopic parts of the cortex which involve several populations of neurons. We consider a class of neural field models which are represented by integro-differential equations with transmission time delays which are space-dependent. The considered domains underlying the systems can be bounded or unbounded. A new approach, called sequential contracting, instead of the conventional Lyapunov functional technique, is employed to investigate the global dynamics of such systems. Sufficient conditions for the absolute stability and synchronization of the systems are established. Several numerical examples are presented to demonstrate the theoretical results.

  4. Absolute IGS antenna phase center model igs08.atx: status and potential improvements

    NASA Astrophysics Data System (ADS)

    Schmid, R.; Dach, R.; Collilieux, X.; Jäggi, A.; Schmitz, M.; Dilssner, F.

    2016-04-01

    On 17 April 2011, all analysis centers (ACs) of the International GNSS Service (IGS) adopted the reference frame realization IGS08 and the corresponding absolute antenna phase center model igs08.atx for their routine analyses. The latter consists of an updated set of receiver and satellite antenna phase center offsets and variations (PCOs and PCVs). An update of the model was necessary due to the difference of about 1 ppb in the terrestrial scale between two consecutive realizations of the International Terrestrial Reference Frame (ITRF2008 vs. ITRF2005), as that parameter is highly correlated with the GNSS satellite antenna PCO components in the radial direction.

  5. A California statewide three-dimensional seismic velocity model from both absolute and differential times

    USGS Publications Warehouse

    Lin, G.; Thurber, C.H.; Zhang, H.; Hauksson, E.; Shearer, P.M.; Waldhauser, F.; Brocher, T.M.; Hardebeck, J.

    2010-01-01

    We obtain a seismic velocity model of the California crust and uppermost mantle using a regional-scale double-difference tomography algorithm. We begin by using absolute arrival-time picks to solve for a coarse three-dimensional (3D) P velocity (VP) model with a uniform 30 km horizontal node spacing, which we then use as the starting model for a finer-scale inversion using double-difference tomography applied to absolute and differential pick times. For computational reasons, we split the state into 5 subregions with a grid spacing of 10 to 20 km and assemble our final statewide VP model by stitching together these local models. We also solve for a statewide S-wave model using S picks from both the Southern California Seismic Network and USArray, assuming a starting model based on the VP results and a VP=VS ratio of 1.732. Our new model has improved areal coverage compared with previous models, extending 570 km in the SW-NE directionand 1320 km in the NW-SE direction. It also extends to greater depth due to the inclusion of substantial data at large epicentral distances. Our VP model generally agrees with previous separate regional models for northern and southern California, but we also observe some new features, such as high-velocity anomalies at shallow depths in the Klamath Mountains and Mount Shasta area, somewhat slow velocities in the northern Coast Ranges, and slow anomalies beneath the Sierra Nevada at midcrustal and greater depths. This model can be applied to a variety of regional-scale studies in California, such as developing a unified statewide earthquake location catalog and performing regional waveform modeling.

  6. A strict test of stellar evolution models: The absolute dimensions of the massive benchmark eclipsing binary V578 Mon

    SciTech Connect

    Garcia, E. V.; Stassun, Keivan G.; Pavlovski, K.; Hensberge, H.; Chew, Y. Gómez Maqueo; Claret, A.

    2014-09-01

    We determine the absolute dimensions of the eclipsing binary V578 Mon, a detached system of two early B-type stars (B0V + B1V, P = 2.40848 days) in the star-forming region NGC 2244 of the Rosette Nebula. From the light curve analysis of 40 yr of photometry and the analysis of HERMES spectra, we find radii of 5.41 ± 0.04 R{sub ☉} and 4.29 ± 0.05 R{sub ☉}, and temperatures of 30,000 ± 500 K and 25,750 ± 435 K, respectively. We find that our disentangled component spectra for V578 Mon agree well with previous spectral disentangling from the literature. We also reconfirm the previous spectroscopic orbit of V578 Mon finding that masses of 14.54 ± 0.08 M{sub ☉} and 10.29 ± 0.06 M{sub ☉} are fully compatible with the new analysis. We compare the absolute dimensions to the rotating models of the Geneva and Utrecht groups and the models of the Granada group. We find that all three sets of models marginally reproduce the absolute dimensions of both stars with a common age within the uncertainty for gravity-effective temperature isochrones. However, there are some apparent age discrepancies for the corresponding mass-radius isochrones. Models with larger convective overshoot, >0.35, worked best. Combined with our previously determined apsidal motion of 0.07089{sub −0.00013}{sup +0.00021} deg cycle{sup –1}, we compute the internal structure constants (tidal Love number) for the Newtonian and general relativistic contribution to the apsidal motion as log k {sub 2} = –1.975 ± 0.017 and log k {sub 2} = –3.412 ± 0.018, respectively. We find the relativistic contribution to the apsidal motion to be small, <4%. We find that the prediction of log k {sub 2,theo} = –2.005 ± 0.025 of the Granada models fully agrees with our observed log k {sub 2}.

  7. Borehole magnetostratigraphy, absolute age dating, and correlation of sedimentary rocks, with examples from the Paris Basin, France

    SciTech Connect

    Bouisset, P.M. ); Augustin, A.M. )

    1993-04-01

    Total and CEA have conceived and developed two new logging tools which allow continuous, precise, and accurate in-situ magnetic measurements within weakly magnetized sedimentary rocks encountered in uncased industry drilled wells. The combination of these magnetic measurements permits for the first time continuous determination of natural remanent magnetization (NRM) polarities occurring in the logged section. The resulting well magnetostratigraphic sequence (WMS) which may be recognized from well to well (magnetostratigraphic correlations), may also be correlative to a geomagnetic polarity time scale (GPTS) of reference magnetostratigraphic scale (RMS), given adequate dating tie points and lack of noticeable remagnetizations. Application of this method to the Upper Jurrasic formation in four wells of the Paris basin has yielded promising results for both stratigraphic and near absolute age correlations as well as determination of facies diachronisms. The comparison of results obtained from magnetic measurements and from sequence stratigraphy analysis shows that third-order sequence boundaries may be correlative to geomagnetic reversals, but may also be diachronous in wells 80 km or less apart. The potential of borehole magnetic measurements as presented in this paper is still under investigation. However, these encouraging initial results show that this new investigating and dating method could be of great help in the analysis of subsurface stratigraphy by extending the concepts of magnetostratigraphy from the outcrops and laboratory directly into borehole logging. 81 refs., 18 figs.

  8. Evaluation of Generalized Born Model Accuracy for Absolute Binding Free Energy Calculations.

    PubMed

    Zeller, Fabian; Zacharias, Martin

    2014-06-27

    Generalized Born (GB) implicit solvent models are widely used in molecular dynamics simulations to evaluate the interactions of biomolecular complexes. The continuum treatment of the solvent results in significant computational savings in comparison to an explicit solvent representation. It is, however, not clear how accurately the GB approach reproduces the absolute free energies of biomolecular binding. On the basis of induced dissociation by means of umbrella sampling simulations, the absolute binding free energies of small proline-rich peptide ligands and a protein receptor were calculated. Comparative simulations according to the same protocol were performed by employing an explicit solvent model and various GB-type implicit solvent models in combination with a nonpolar surface tension term. The peptide ligands differed in a key residue at the peptide-protein interface, including either a nonpolar, a neutral polar, a positively charged, or a negatively charged group. For the peptides with a neutral polar or nonpolar interface residue, very good agreement between the explicit solvent and GB implicit solvent results was found. Deviations in the main separation free energy contributions are smaller than 1 kcal/mol. In contrast, for peptides with a charged interface residue, significant deviations of 2-4 kcal/mol were observed. The results indicate that recent GB models can compete with explicit solvent representations in total binding free energy calculations as long as no charged residues are present at the binding interface. PMID:24941018

  9. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  10. ALL AGES LEAD MODEL

    EPA Science Inventory

    The Integrated Exposure Uptake Biokinetic (IEUBK) Model for Lead in Children (version 0.99d) was released in March 1994, and has been widely accepted in the risk assessment community as a tool for implementing the site specific risk assessment process when the issue is childhood...

  11. Age models and their uncertainties

    NASA Astrophysics Data System (ADS)

    Marwan, N.; Rehfeld, K.; Goswami, B.; Breitenbach, S. F. M.; Kurths, J.

    2012-04-01

    The usefulness of a proxy record is largely dictated by accuracy and precision of its age model, i.e., its depth-age relationship. Only if age model uncertainties are minimized correlations or lead-lag relations can be reliably studied. Moreover, due to different dating strategies (14C, U-series, OSL dating, or counting of varves), dating errors or diverging age models lead to difficulties in comparing different palaeo proxy records. Uncertainties in the age model are even more important if an exact dating is necessary in order to calculate, e.g., data series of flux or rates (like dust flux records, pollen deposition rates). Several statistical approaches exist to handle the dating uncertainties themselves and to estimate the age-depth relationship. Nevertheless, linear interpolation is still the most commonly used method for age modeling. The uncertainties of a certain event at a given time due to the dating errors are often even completely neglected. Here we demonstrate the importance of considering dating errors and implications for the interpretation of variations in palaeo-climate proxy records from stalagmites (U-series dated). We present a simple approach for estimating age models and their confidence levels based on Monte Carlo methods and non-linear interpolation. This novel algorithm also allows for removing age reversals. Our approach delivers a time series of a proxy record with a value range for each age depth also, if desired, on an equidistant time axis. The algorithm is implemented in interactive scripts for use with MATLAB®, Octave, and FreeMat.

  12. Improved Strategies and Optimization of Calibration Models for Real-time PCR Absolute Quantification

    EPA Science Inventory

    Real-time PCR absolute quantification applications rely on the use of standard curves to make estimates of DNA target concentrations in unknown samples. Traditional absolute quantification approaches dictate that a standard curve must accompany each experimental run. However, t...

  13. Aging Research Using Mouse Models

    PubMed Central

    Ackert-Bicknell, Cheryl L.; Anderson, Laura; Sheehan, Susan; Hill, Warren G.; Chang, Bo; Churchill, Gary A.; Chesler, Elissa J.; Korstanje, Ron; Peters, Luanne L.

    2015-01-01

    Despite the dramatic increase in human lifespan over the past century, there remains pronounced variability in “health-span”, or the period of time in which one is generally healthy and free of disease. Much of the variability in health-span and lifespan is thought to be genetic in origin. Understanding the genetic mechanisms of aging and identifying ways to boost longevity is a primary goal in aging research. Here, we describe a pipeline of phenotypic assays for assessing mouse models of aging. This pipeline includes behavior/cognition testing, body composition analysis, and tests of kidney function, hematopoiesis, immune function and physical parameters. We also describe study design methods for assessing lifespan and health-span, and other important considerations when conducting aging research in the laboratory mouse. The tools and assays provided can assist researchers with understanding the correlative relationships between age-associated phenotypes and, ultimately, the role of specific genes in the aging process. PMID:26069080

  14. Computations of absolute solvation free energies of small molecules using explicit and implicit solvent model.

    SciTech Connect

    Shivakumar, D.; Deng, Y.; Roux, B.; Biosciences Division; Univ. of Chicago

    2009-01-01

    Accurate determination of absolute solvation free energy plays a critical role in numerous areas of biomolecular modeling and drug discovery. A quantitative representation of ligand and receptor desolvation, in particular, is an essential component of current docking and scoring methods. Furthermore, the partitioning of a drug between aqueous and nonpolar solvents is one of the important factors considered in pharmacokinetics. In this study, the absolute hydration free energy for a set of 239 neutral ligands spanning diverse chemical functional groups commonly found in drugs and drug-like candidates is calculated using the molecular dynamics free energy perturbation method (FEP/MD) with explicit water molecules, and compared to experimental data as well as its counterparts obtained using implicit solvent models. The hydration free energies are calculated from explicit solvent simulations using a staged FEP procedure permitting a separation of the total free energy into polar and nonpolar contributions. The nonpolar component is further decomposed into attractive (dispersive) and repulsive (cavity) components using the Weeks-Chandler-Anderson (WCA) separation scheme. To increase the computational efficiency, all of the FEP/MD simulations are generated using a mixed explicit/implicit solvent scheme with a relatively small number of explicit TIP3P water molecules, in which the influence of the remaining bulk is incorporated via the spherical solvent boundary potential (SSBP). The performances of two fixed-charge force fields designed for small organic molecules, the General Amber force field (GAFF), and the all-atom CHARMm-MSI, are compared. Because of the crucial role of electrostatics in solvation free energy, the results from various commonly used charge generation models based on the semiempirical (AM1-BCC) and QM calculations [charge fitting using ChelpG and RESP] are compared. In addition, the solvation free energies of the test set are also calculated using

  15. Photochirogenesis: Photochemical models on the absolute asymmetric formation of amino acids in interstellar space

    NASA Astrophysics Data System (ADS)

    Meinert, Cornelia; de Marcellus, Pierre; Le Sergeant D'Hendecourt, Louis; Nahon, Laurent; Jones, Nykola C.; Hoffmann, Søren V.; Bredehöft, Jan Hendrik; Meierhenrich, Uwe J.

    2011-10-01

    Proteins of all living organisms including plants, animals, and humans are made up of amino acid monomers that show identical stereochemical L-configuration. Hypotheses for the origin of this symmetry breaking in biomolecules include the absolute asymmetric photochemistry model by which interstellar ultraviolet (UV) circularly polarized light (CPL) induces an enantiomeric excess in chiral organic molecules in the interstellar/circumstellar media. This scenario is supported by a) the detection of amino acids in the organic residues of UV-photo-processed interstellar ice analogues, b) the occurrence of L-enantiomer-enriched amino acids in carbonaceous meteorites, and c) the observation of CPL of the same helicity over large distance scales in the massive star-forming region of Orion. These topics are of high importance in topical biophysical research and will be discussed in this review. Further evidence that amino acids and other molecules of prebiotic interest are asymmetrically formed in space comes from studies on the enantioselective photolysis of amino acids by UV-CPL. Also, experiments have been performed on the absolute asymmetric photochemical synthesis of enantiomer-enriched amino acids from mixtures of astrophysically relevant achiral precursor molecules using UV-circularly polarized photons. Both approaches are based on circular dichroic transitions of amino acids that will be highlighted here as well. These results have strong implications on our current understanding of how life's precursor molecules were possibly built and how life selected the left-handed form of proteinogenic amino acids.

  16. Modeling absolute differences in life expectancy with a censored skew-normal regression approach

    PubMed Central

    Clough-Gorr, Kerri; Zwahlen, Marcel

    2015-01-01

    Parameter estimates from commonly used multivariable parametric survival regression models do not directly quantify differences in years of life expectancy. Gaussian linear regression models give results in terms of absolute mean differences, but are not appropriate in modeling life expectancy, because in many situations time to death has a negative skewed distribution. A regression approach using a skew-normal distribution would be an alternative to parametric survival models in the modeling of life expectancy, because parameter estimates can be interpreted in terms of survival time differences while allowing for skewness of the distribution. In this paper we show how to use the skew-normal regression so that censored and left-truncated observations are accounted for. With this we model differences in life expectancy using data from the Swiss National Cohort Study and from official life expectancy estimates and compare the results with those derived from commonly used survival regression models. We conclude that a censored skew-normal survival regression approach for left-truncated observations can be used to model differences in life expectancy across covariates of interest. PMID:26339544

  17. Surveying implicit solvent models for estimating small molecule absolute hydration free energies

    PubMed Central

    Knight, Jennifer L.

    2011-01-01

    Implicit solvent models are powerful tools in accounting for the aqueous environment at a fraction of the computational expense of explicit solvent representations. Here, we compare the ability of common implicit solvent models (TC, OBC, OBC2, GBMV, GBMV2, GBSW, GBSW/MS, GBSW/MS2 and FACTS) to reproduce experimental absolute hydration free energies for a series of 499 small neutral molecules that are modeled using AMBER/GAFF parameters and AM1-BCC charges. Given optimized surface tension coefficients for scaling the surface area term in the nonpolar contribution, most implicit solvent models demonstrate reasonable agreement with extensive explicit solvent simulations (average difference 1.0-1.7 kcal/mol and R2=0.81-0.91) and with experimental hydration free energies (average unsigned errors=1.1-1.4 kcal/mol and R2=0.66-0.81). Chemical classes of compounds are identified that need further optimization of their ligand force field parameters and others that require improvement in the physical parameters of the implicit solvent models themselves. More sophisticated nonpolar models are also likely necessary to more effectively represent the underlying physics of solvation and take the quality of hydration free energies estimated from implicit solvent models to the next level. PMID:21735452

  18. COnstructing Proxy-Record Age models (COPRA)

    NASA Astrophysics Data System (ADS)

    Marwan, Norbert; Rehfeld, Kira; Goswami, Bedartha; Breitenbach, Sebastian F. M.; Kurths, Jürgen

    2013-04-01

    Reliable age models are fundamental for any palaeoclimate reconstruction. The increasing availability of high-resolution palaeoclimate time series, e.g., based on speleothem archives, has attracted some new activity in the development of alternative and novel approaches for reconstructing chronologies. Challenges in this effort are (semi-)automatic outlier, reversal, and hiatus detection and treatment, as well as the inclusion of information on age uncertainties and independent layer counting to improve the overall precision of the chronology. However, different dating strategies, different kinds of palaeoarchive formation, dating uncertainties, and different chronology construction methods cause a limited comparability of the different palaeoclimate records. We present a recently developed framework which addresses these challenges and which allows the incorporation of layer counting data to improve the reconstructed chronology of a given time series. Moreover, we introduce the concept of an "absolute" time scale, a common time axis which works as an invariant reference allowing the comparison of different palaeoclimate records. This concept translates the age uncertainties into uncertainties in the proxy values. This framework is implemented as an open source software (COPRA) for Octave and Matlab.

  19. Enhanced Cortical Connectivity in Absolute Pitch Musicians: A Model for Local Hyperconnectivity

    PubMed Central

    Loui, Psyche; Charles Li, Hui C.; Hohmann, Anja; Schlaug, Gottfried

    2010-01-01

    Connectivity in the human brain has received increased scientific interest in recent years. Although connection disorders can affect perception, production, learning, and memory, few studies have associated brain connectivity with graded variations in human behavior, especially among normal individuals. One group of normal individuals who possess unique characteristics in both behavior and brain structure is absolute pitch (AP) musicians, who can name the appropriate pitch class of any given tone without a reference. Using diffusion tensor imaging and tractography, we observed hyperconnectivity in bilateral superior temporal lobe structures linked to AP possession. Furthermore, volume of tracts connecting left superior temporal gyrus to left middle temporal gyrus predicted AP performance. These findings extend previous reports of exaggerated temporal lobe asymmetry, may explain the higher incidence of AP in developmental disorders, and may provide a model for understanding the heightened connectivity that is thought to underlie savant skills and cases of exceptional creativity. PMID:20515408

  20. ON A NEW NEAR-INFRARED METHOD TO ESTIMATE THE ABSOLUTE AGES OF STAR CLUSTERS: NGC 3201 AS A FIRST TEST CASE

    SciTech Connect

    Bono, G.; Di Cecco, A.; Sanna, N.; Buonanno, R.; Stetson, P. B.; VandenBerg, D. A.; Calamida, A.; Amico, P.; Marchetti, E.; D'Odorico, S.; Gilmozzi, R.; Dall'Ora, M.; Iannicola, G.; Caputo, F.; Corsi, C. E.; Ferraro, I.; Monelli, M.; Walker, A. R.; Zoccali, M.; Degl'Innocenti, S.

    2010-01-10

    We present a new method to estimate the absolute ages of stellar systems. This method is based on the difference in magnitude between the main-sequence turnoff (MSTO) and a well-defined knee located along the lower main sequence (MSK). This feature is caused by the collisionally induced absorption of molecular hydrogen, and it can easily be identified in near-infrared (NIR) and in optical-NIR color-magnitude diagrams of stellar systems. We took advantage of deep and accurate NIR images collected with the Multi-Conjugate Adaptive Optics Demonstrator temporarily available on the Very Large Telescope and of optical images collected with the Advanced Camera for Surveys Wide Field Camera on the Hubble Space Telescope and with ground-based telescopes to estimate the absolute age of the globular NGC 3201 using both the MSTO and the {delta}(MSTO-MSK). We have adopted a new set of cluster isochrones, and we found that the absolute ages based on the two methods agree to within 1{sigma}. However, the errors of the ages based on the {delta}(MSTO-MSK) method are potentially more than a factor of 2 smaller, since they are not affected by uncertainties in cluster distance or reddening. Current isochrones appear to predict slightly bluer ({approx}0.05 mag) NIR and optical-NIR colors than observed for magnitudes fainter than the MSK.

  1. Nilpotent and absolutely anticommuting symmetries in the Freedman-Townsend model: Augmented superfield formalism

    NASA Astrophysics Data System (ADS)

    Shukla, A.; Krishna, S.; Malik, R. P.

    2014-12-01

    We derive the off-shell nilpotent and absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations, corresponding to the (1-form) Yang-Mills (YM) and (2-form) tensorial gauge symmetries of the four (3+1)-dimensional (4D) Freedman-Townsend (FT) model, by exploiting the augmented version of Bonora-Tonin's (BT) superfield approach to BRST formalism where the 4D flat Minkowskian theory is generalized onto the (4, 2)-dimensional supermanifold. One of the novel observations is the fact that we are theoretically compelled to go beyond the horizontality condition (HC) to invoke an additional set of gauge-invariant restrictions (GIRs) for the derivation of the full set of proper (anti-)BRST symmetries. To obtain the (anti-)BRST symmetry transformations, corresponding to the tensorial (2-form) gauge symmetries within the framework of augmented version of BT-superfield approach, we are logically forced to modify the FT-model to incorporate an auxiliary 1-form field and the kinetic term for the antisymmetric (2-form) gauge field. This is also a new observation in our present investigation. We point out some of the key differences between the modified FT-model and Lahiri-model (LM) of the dynamical non-Abelian 2-form gauge theories. We also briefly mention a few similarities.

  2. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  3. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  4. Absolute vs. weight-related maximum oxygen uptake in firefighters: fitness evaluation with and without protective clothing and self-contained breathing apparatus among age group.

    PubMed

    Perroni, Fabrizio; Guidetti, Laura; Cignitti, Lamberto; Baldari, Carlo

    2015-01-01

    During fire emergencies, firefighters wear personal protective devices (PC) and a self-contained breathing apparatus (S.C.B.A.) to be protected from injuries. The purpose of this study was to investigate the differences of aerobic level in 197 firefighters (age: 34±7 yr; BMI: 24.4±2.3 kg.m-2), evaluated by a Queen's College Step field Test (QCST), performed with and without fire protective garments, and to analyze the differences among age groups (<25 yr; 26-30 yr, 31-35 yr, 36-40 yr and >40 yr). Variance analysis was applied to assess differences (p < 0.05) between tests and age groups observed in absolute and weight-related values, while a correlation was examined between QCST with and without PC+S.C.B.A. The results have shown that a 13% of firefighters failed to complete the test with PC+S.C.B.A. and significant differences between QCST performed with and without PC+S.C.B.A. in absolute (F(1,169) = 42.6, p < 0.0001) and weight-related (F(1,169) = 339.9, p < 0.0001) terms. A better correlation has been found in L•min-1 (r=0.67) than in ml•kg-1•min-1 (r=0.54). Moreover, we found significant differences among age groups both in absolute and weight-related values. The assessment of maximum oxygen uptake of firefighters in absolute term can be a useful tool to evaluate the firefighters' cardiovascular strain. PMID:25764201

  5. An Integrated Model of Choices and Response Times in Absolute Identification

    ERIC Educational Resources Information Center

    Brown, Scott D.; Marley, A. A. J.; Donkin, Christopher; Heathcote, Andrew

    2008-01-01

    Recent theoretical developments in the field of absolute identification have stressed differences between relative and absolute processes, that is, whether stimulus magnitudes are judged relative to a shorter term context provided by recently presented stimuli or a longer term context provided by the entire set of stimuli. The authors developed a…

  6. Model based period analysis of absolute and relative survival with R: data preparation, model fitting and derivation of survival estimates.

    PubMed

    Holleczek, Bernd; Brenner, Hermann

    2013-05-01

    Period analysis is increasingly employed in analyses of long-term survival of patients with chronic diseases such as cancer, as it derives more up-to-date survival estimates than traditional cohort based approaches. It has recently been extended with regression modelling using generalized linear models, which increases the precision of the survival estimates and enables to assess and account for effects of additional covariates. This paper provides a detailed presentation how model based period analysis may be used to derive population-based absolute and relative survival estimates using the freely available R language and statistical environment and already available R programs for period analysis. After an introduction of the underlying regression model and a description of the software tools we provide a step-by-step implementation of two regression models in R and illustrate how estimates and a test for trend over time in relative survival may be derived using data from a population based cancer registry. PMID:23116692

  7. Reinvestigation of age model for relative paleointensity stack and application to Lake Baikal record

    NASA Astrophysics Data System (ADS)

    Oda, H.

    2014-12-01

    The age model for relative paleointensity stack PISO-1500 (Channell et al., 2009) is based on IODP U1308 from North Atlantic. Channell et al. (2008) developed the age model for U1308 by correlating the benthic oxygen isotope curve with LR04 oxygen isotope stack (Lisiecki&Raymo, 2005). LR04 stack is known as oxygen isotope stack for benthic foraminifarra, whose age model is dependent on ice volume model with a certain time lag. On the other hand, Caballero-Gill et al. (2012) developed an absolute age model based on U-Th dating for stalagmites from China and correlated the oxygen isotope curve with that on planctonic foraminiferra for a deep-sea core from South China Sea. The age model based on absolute dating for stalagmite was then transfered to oxygen isotope curve of benthic forraminiferra for the same core. This enables to provide absolute age model on PISO-1500 for the past 350 kyrs. The resulting modified PISO-1500 was applied on paleomagnetic records from Lake Baikal to provide an age model based on relative paleointensity. Finally, this age model was compared with alternative age model based on correlation of biogenic silica record with insolation at the site (Prokopenko et al., 2006) and the reason for the discrepancy will be discussed.

  8. Absolute masses and radii determination in multiplanetary systems without stellar models

    NASA Astrophysics Data System (ADS)

    Almenara, J. M.; Díaz, R. F.; Mardling, R.; Barros, S. C. C.; Damiani, C.; Bruno, G.; Bonfils, X.; Deleuil, M.

    2015-11-01

    The masses and radii of extrasolar planets are key observables for understanding their interior, formation and evolution. While transit photometry and Doppler spectroscopy are used to measure the radii and masses respectively of planets relative to those of their host star, estimates for the true values of these quantities rely on theoretical models of the host star which are known to suffer from systematic differences with observations. When a system is composed of more than two bodies, extra information is contained in the transit photometry and radial velocity data. Velocity information (finite speed-of-light, Doppler) is needed to break the Newtonian MR-3 degeneracy. We performed a photodynamical modelling of the two-planet transiting system Kepler-117 using all photometric and spectroscopic data available. We demonstrate how absolute masses and radii of single-star planetary systems can be obtained without resorting to stellar models. Limited by the precision of available radial velocities (38 m s-1), we achieve accuracies of 20 per cent in the radii and 70 per cent in the masses, while simulated 1 m s-1 precision radial velocities lower these to 1 per cent for the radii and 2 per cent for the masses. Since transiting multiplanet systems are common, this technique can be used to measure precisely the mass and radius of a large sample of stars and planets. We anticipate these measurements will become common when the TESS and PLATO mission provide high-precision light curves of a large sample of bright stars. These determinations will improve our knowledge about stars and planets, and provide strong constraints on theoretical models.

  9. College Students' Role Models, Learning Style Preferences, and Academic Achievement in Collaborative Teaching: Absolute versus Relativistic Thinking

    ERIC Educational Resources Information Center

    Chiou, Wen-Bin

    2008-01-01

    Based on the perspective of postformal operations, this study investigated whether college students' role models (technical teachers vs. lecturing teachers) and preferred learning styles (experience-driven mode vs. theory-driven mode) in collaborative teaching courses would be moderated by their cognitive development (absolute thinking vs.…

  10. ABSOLUTE DIMENSIONS OF THE G7+K7 ECLIPSING BINARY STAR IM VIRGINIS: DISCREPANCIES WITH STELLAR EVOLUTION MODELS

    SciTech Connect

    Morales, Juan Carlos; Marschall, Laurence A.; Brehm, William

    2009-12-10

    We report extensive spectroscopic and differential photometric BVRI observations of the active, detached, 1.309-day double-lined eclipsing binary IM Vir, composed of a G7-type primary and a K7 secondary. With these observations, we derive accurate absolute masses and radii of M {sub 1} = 0.981 +- 0.012 M {sub sun}, M {sub 2} = 0.6644 +- 0.0048 M {sub sun}, R {sub 1} = 1.061 +- 0.016 R {sub sun}, and R {sub 2} = 0.681 +- 0.013 R {sub sun} for the primary and secondary, with relative errors under 2%. The effective temperatures are 5570 +- 100 K and 4250 +- 130 K, respectively. The significant difference in mass makes this a favorable case for comparison with stellar evolution theory. We find that both stars are larger than the models predict, by 3.7% for the primary and 7.5% for the secondary, as well as cooler than expected, by 100 K and 150 K, respectively. These discrepancies are in line with previously reported differences in low-mass stars, and are believed to be caused by chromospheric activity, which is not accounted for in current models. The effect is not confined to low-mass stars: the rapidly rotating primary of IM Vir joins the growing list of objects of near-solar mass (but still with convective envelopes) that show similar anomalies. The comparison with the models suggests an age of 2.4 Gyr for the system, and a metallicity of [Fe/H] approx-0.3 that is consistent with other indications, but requires confirmation.

  11. Evaluation of the Re-Os Geochronometer in Organic-rich Mudrocks as a Method for Constraining the Absolute Ages of Neoproterozoic Glaciogenic Deposits

    NASA Astrophysics Data System (ADS)

    Kendall, B. S.; Creaser, R. A.; Ross, G. M.

    2002-12-01

    Absolute-age constraints on the Neoproterozoic glaciations are generally poor due to a paucity of suitable plutonic and volcanic igneous rocks that are temporally and spatially related to Neoproterozoic glaciogenic deposits and are amenable to radiometric dating methods. In this study, the Re-Os isotope systematics of dark gray, sulfidic slates from the Old Fort Point Formation (OFP) of the Windermere Supergroup (near Jasper, Alberta) were examined to test the ability of the Re-Os geochronometer to provide an absolute age constraint for a Neoproterozoic glaciogenic deposit. The OFP has been interpreted as the deep water expression of post-glacial sea level rise and therefore is comparable stratigraphically to cap carbonates that immediately overlie glaciogenic deposits worldwide. Despite the relatively low Re (6-16 ppb) and Os (0.07-0.14 ppb) concentrations and total organic contents (~ 0.5% TOC) of the slates compared to other organic-rich mudrocks used in previous Re-Os isotope studies, precise well-fitted Re-Os isochrons have been obtained with two different dissolution methods. An age of 620.8 +/- 8.1 Ma (MSWD = 0.9; initial 187Os/188Os = 0.68 +/- 0.06) is obtained using conventional aqua regia dissolution. Using a method designed to selectively dissolve organic matter alone, an age of 609.0 +/- 8.3 Ma (MSWD = 1.5; initial 187Os/188Os = 0.62 +/- 0.05) is obtained. These absolute age results are in accord with existing age constraints (e.g., stratigraphically younger Hamill Group with a U-Pb zircon age of 569 Ma). The well-defined Re-Os systematics of the OFP slates demonstrates for the first time that the Re-Os system is not disturbed in organic-rich sediments during lower greenschist (-chlorite) grade metamorphic conditions. The whole-rock analysis of each individual sample yields consistently higher initial 187Os/188Os isotope ratios than the corresponding organic matter analysis and suggests that a significant radiogenic detrital Os component is present

  12. 3D geomechanical-numerical modelling of the absolute stress state for geothermal reservoir exploration

    NASA Astrophysics Data System (ADS)

    Reiter, Karsten; Heidbach, Oliver; Moeck, Inga

    2013-04-01

    For the assessment and exploration of a potential geothermal reservoir, the contemporary in-situ stress is of key importance in terms of well stability and orientation of possible fluid pathways. However, available data, e.g. Heidbach et al. (2009) or Zang et al. (2012), deliver only point wise information of parts of the six independent components of the stress tensor. Moreover most measurements of the stress orientation and magnitude are done for hydrocarbon industry obvious in shallow depth. Interpolation across long distances or extrapolation into depth is unfavourable, because this would ignore structural features, inhomogeneity's in the crust or other local effects like topography. For this reasons geomechanical numerical modelling is the favourable method to quantify orientations and magnitudes of the 3D stress field for a geothermal reservoir. A geomechanical-numerical modelling, estimating the 3D absolute stress state, requires the initial stress state as model constraints. But in-situ stress measurements within or close by a potential reservoir are rare. For that reason a larger regional geomechanical-numerical model is necessary, which derive boundary conditions for the wanted local reservoir model. Such a large scale model has to be tested against in-situ stress measurements, orientations and magnitudes. Other suitable and available data, like GPS measurements or fault slip rates are useful to constrain kinematic boundary conditions. This stepwise approach from regional to local scale takes all stress field factors into account, from first over second up to third order. As an example we present a large scale crustal and upper mantle 3D-geomechanical-numerical model of the Alberta Basin and the surroundings, which is constructed to describe continuously the full stress tensor. In-situ stress measurements are the most likely data, because they deliver the most direct information's of the stress field and they provide insights into different depths, a

  13. The Case for Absolute Ligand Discrimination: Modeling Information Processing and Decision by Immune T Cells

    NASA Astrophysics Data System (ADS)

    François, Paul; Altan-Bonnet, Grégoire

    2016-03-01

    Some cells have to take decision based on the quality of surroundings ligands, almost irrespective of their quantity, a problem we name "absolute discrimination". An example of absolute discrimination is recognition of not-self by immune T Cells. We show how the problem of absolute discrimination can be solved by a process called "adaptive sorting". We review several implementations of adaptive sorting, as well as its generic properties such as antagonism. We show how kinetic proofreading with negative feedback implement an approximate version of adaptive sorting in the immune context. Finally, we revisit the decision problem at the cell population level, showing how phenotypic variability and feedbacks between population and single cells are crucial for proper decision.

  14. Absolute Entropy and Energy of Carbon Dioxide Using the Two-Phase Thermodynamic Model.

    PubMed

    Huang, Shao-Nung; Pascal, Tod A; Goddard, William A; Maiti, Prabal K; Lin, Shiang-Tai

    2011-06-14

    The two-phase thermodynamic (2PT) model is used to determine the absolute entropy and energy of carbon dioxide over a wide range of conditions from molecular dynamics trajectories. The 2PT method determines the thermodynamic properties by applying the proper statistical mechanical partition function to the normal modes of a fluid. The vibrational density of state (DoS), obtained from the Fourier transform of the velocity autocorrelation function, converges quickly, allowing the free energy, entropy, and other thermodynamic properties to be determined from short 20-ps MD trajectories. The anharmonic effects in the vibrations are accounted for by the broadening of the normal modes into bands from sampling the velocities over the trajectory. The low frequency diffusive modes, which lead to finite DoS at zero frequency, are accounted for by considering the DoS as a superposition of gas-phase and solid-phase components (two phases). The analytical decomposition of the DoS allows for an evaluation of properties contributed by different types of molecular motions. We show that this 2PT analysis leads to accurate predictions of entropy and energy of CO2 over a wide range of conditions (from the triple point to the critical point of both the vapor and the liquid phases along the saturation line). This allows the equation of state of CO2 to be determined, which is limited only by the accuracy of the force field. We also validated that the 2PT entropy agrees with that determined from thermodynamic integration, but 2PT requires only a fraction of the time. A complication for CO2 is that its equilibrium configuration is linear, which would have only two rotational modes, but during the dynamics it is never exactly linear, so that there is a third mode from rotational about the axis. In this work, we show how to treat such linear molecules in the 2PT framework. PMID:26596450

  15. Using a Novel Absolute Ontogenetic Age Determination Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis

    PubMed Central

    Wysocki, M. Aleksander; Feranec, Robert S.; Tseng, Zhijie Jack; Bjornsson, Christopher S.

    2015-01-01

    Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates absolute ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for absolute ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation. PMID:26132165

  16. Absolute Zero

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell J.; Sheibley, D.; Belloni, M.; Stamper-Kurn, D.; Vinen, W. F.

    2006-12-01

    Absolute Zero is a two hour PBS special attempting to bring to the general public some of the advances made in 400 years of thermodynamics. It is based on the book “Absolute Zero and the Conquest of Cold” by Tom Shachtman. Absolute Zero will call long-overdue attention to the remarkable strides that have been made in low-temperature physics, a field that has produced 27 Nobel Prizes. It will explore the ongoing interplay between science and technology through historical examples including refrigerators, ice machines, frozen foods, liquid oxygen and nitrogen as well as much colder fluids such as liquid hydrogen and liquid helium. A website has been established to promote the series: www.absolutezerocampaign.org. It contains information on the series, aimed primarily at students at the middle school level. There is a wealth of material here and we hope interested teachers will draw their student’s attention to this website and its substantial contents, which have been carefully vetted for accuracy.

  17. Investigation of origin for seawater intrusion using geophysical well logs and absolute ages of volcanic cores in the eastern part of Jeju Island

    NASA Astrophysics Data System (ADS)

    Hwang, Seho; Shin, Jehyun

    2010-05-01

    Jeju located in the southern extremity of Korea is volcanic island, one of best-known tourist attractions in Korea. Jeju Province operates the monitoring boreholes for the evaluation of groundwater resources in coastal area. Major rock types identified from drill cores are trachybasalt, acicular basalt, scoria, hyalocastite, tuff, unconsolidated U formation, and seoguipo formation and so on. Various conventional geophysical well loggings including radioactive logs (natural gamma log, dual neutron log, and gamma-gamma log), electrical log (or electromagnetic induction log), caliper log, fluid temperature/ conductivity log, and televiewer logs have been conducted to identify basalt sequences and permeable zone, and verify seawater intrusion in monitoring boreholes. The conductivity logs clearly show the fresh water-saline water boundaries, but we find it hard to identify the permeable zones because of the mixed groundwater within the boreholes. Temperature gradient logs are mostly related with lithologic boundaries and permeable zones intersected by boreholes of eastern coasts. The wide range of periodic electrical conductivity logging in the deeper depth of monitoring boreholes indicates the possibility of submarine groundwater discharge. However we did not clearly understand the origin of seawater intrusion in the eastern coast until now. So we analysis the electrical conductivity profiles, record of sea-level change and 40Ar/39Ar absolute ages of volcanic rock cores from twenty boreholes in east coast. From comparing absolute ages of volcanic rock cores and sea-level of their ages, we find that the almost ages of depth showing high salinity groundwater are about 100 Ka, and from 130Ka to about 180Ka. The former is after the interglacial period and the latter is illinoian. These results indicate that the abrupt raising of sea level after illinoian formed the regional coast, and the zone of present seawater intrusion also are above the depth of illinoin period. So

  18. [Experimental models of human skin aging].

    PubMed

    Nikolakis, G; Zoschke, C; Makrantonaki, E; Hausmann, C; Schäfer-Korting, M; Zouboulis, C C

    2016-02-01

    The skin is a representative model for the study of human aging. Despite the high regenerative capacity of the skin, skin physiology changes over the course of life. Medical and cosmetic research is trying to prevent aging, to slow, to stop, or to reverse it. Effects of age-related DNA damage and of changing skin structure on pharmacological parameters are largely unknown. This review article summarizes the state of scientific knowledge in the field of experimental models of human skin aging and shows approaches to improve organotypic skin models, to develop predictive models of aging, and improve aging research. PMID:26743051

  19. Gender equality and women's absolute status: a test of the feminist models of rape.

    PubMed

    Martin, Kimberly; Vieraitis, Lynne M; Britto, Sarah

    2006-04-01

    Feminist theory predicts both a positive and negative relationship between gender equality and rape rates. Although liberal and radical feminist theory predicts that gender equality should ameliorate rape victimization, radical feminist theorists have argued that gender equality may increase rape in the form of male backlash. Alternatively, Marxist criminologists focus on women's absolute socioeconomic status rather than gender equality as a predictor of rape rates, whereas socialist feminists combine both radical and Marxist perspectives. This study uses factor analysis to overcome multicollinearity limitations of past studies while exploring the relationship between women's absolute and relative socioeconomic status on rape rates in major U.S. cities using 2000 census data. The findings indicate support for both the Marxist and radical feminist explanations of rape but no support for the ameliorative hypothesis. These findings support a more inclusive socialist feminist theory that takes both Marxist and radical feminist hypotheses into account. PMID:16567334

  20. Determining the importance of model calibration for forecasting absolute/relative changes in streamflow from LULC and climate changes

    USGS Publications Warehouse

    Niraula, Rewati; Meixner, Thomas; Norman, Laura M.

    2015-01-01

    Land use/land cover (LULC) and climate changes are important drivers of change in streamflow. Assessing the impact of LULC and climate changes on streamflow is typically done with a calibrated and validated watershed model. However, there is a debate on the degree of calibration required. The objective of this study was to quantify the variation in estimated relative and absolute changes in streamflow associated with LULC and climate changes with different calibration approaches. The Soil and Water Assessment Tool (SWAT) was applied in an uncalibrated (UC), single outlet calibrated (OC), and spatially-calibrated (SC) mode to compare the relative and absolute changes in streamflow at 14 gaging stations within the Santa Cruz River Watershed in southern Arizona, USA. For this purpose, the effect of 3 LULC, 3 precipitation (P), and 3 temperature (T) scenarios were tested individually. For the validation period, Percent Bias (PBIAS) values were >100% with the UC model for all gages, the values were between 0% and 100% with the OC model and within 20% with the SC model. Changes in streamflow predicted with the UC and OC models were compared with those of the SC model. This approach implicitly assumes that the SC model is “ideal”. Results indicated that the magnitude of both absolute and relative changes in streamflow due to LULC predicted with the UC and OC results were different than those of the SC model. The magnitude of absolute changes predicted with the UC and SC models due to climate change (both P and T) were also significantly different, but were not different for OC and SC models. Results clearly indicated that relative changes due to climate change predicted with the UC and OC were not significantly different than that predicted with the SC models. This result suggests that it is important to calibrate the model spatially to analyze the effect of LULC change but not as important for analyzing the relative change in streamflow due to climate change. This

  1. COnstructing Proxy Records from Age models (COPRA)

    NASA Astrophysics Data System (ADS)

    Breitenbach, S. F. M.; Rehfeld, K.; Goswami, B.; Baldini, J. U. L.; Ridley, H. E.; Kennett, D. J.; Prufer, K. M.; Aquino, V. V.; Asmerom, Y.; Polyak, V. J.; Cheng, H.; Kurths, J.; Marwan, N.

    2012-10-01

    Reliable age models are fundamental for any palaeoclimate reconstruction. Available interpolation procedures between age control points are often inadequately reported, and very few translate age uncertainties to proxy uncertainties. Most available modeling algorithms do not allow incorporation of layer counted intervals to improve the confidence limits of the age model in question. We present a framework that allows detection and interactive handling of age reversals and hiatuses, depth-age modeling, and proxy-record reconstruction. Monte Carlo simulation and a translation procedure are used to assign a precise time scale to climate proxies and to translate dating uncertainties to uncertainties in the proxy values. The presented framework allows integration of incremental relative dating information to improve the final age model. The free software package COPRA1.0 facilitates easy interactive usage.

  2. An absolute chronology for early Egypt using radiocarbon dating and Bayesian statistical modelling

    PubMed Central

    Dee, Michael; Wengrow, David; Shortland, Andrew; Stevenson, Alice; Brock, Fiona; Girdland Flink, Linus; Bronk Ramsey, Christopher

    2013-01-01

    The Egyptian state was formed prior to the existence of verifiable historical records. Conventional dates for its formation are based on the relative ordering of artefacts. This approach is no longer considered sufficient for cogent historical analysis. Here, we produce an absolute chronology for Early Egypt by combining radiocarbon and archaeological evidence within a Bayesian paradigm. Our data cover the full trajectory of Egyptian state formation and indicate that the process occurred more rapidly than previously thought. We provide a timeline for the First Dynasty of Egypt of generational-scale resolution that concurs with prevailing archaeological analysis and produce a chronometric date for the foundation of Egypt that distinguishes between historical estimates. PMID:24204188

  3. College students' role models, learning style preferences, and academic achievement in collaborative teaching: absolute versus relativistic thinking.

    PubMed

    Chiou, Wen-Bin

    2008-01-01

    Based on the perspective of postformal operations, this study investigated whether college students' role models (technical teachers vs. lecturing teachers) and preferred learning styles (experience-driven mode vs. theory-driven mode) in collaborative teaching courses would be moderated by their cognitive development (absolute thinking vs. relativistic thinking) and examine whether academic achievement of students would be contingent upon their preferred learning styles. Two hundred forty-four college students who have taken the technical courses with collaborative teaching participated in this study. The results showed that those participants with absolute thinking perceived the modeling advantage of technical teachers was greater than that of lecturing teachers, preferred the experience-driven mode over the theory-driven mode, and displayed differential academic achievement between technical courses and general courses. On the other hand, the students with relativistic thinking revealed no difference in perceived modeling advantage of role models, learning styles preferences, and academic achievement between two categories of courses. In addition, this research indicates that college students' preferred learning styles would interact with course category (technical courses vs. general courses) to display differential academic achievement. Implications and future directions are discussed. PMID:18447085

  4. Aging Successfully: A Four-Factor Model

    ERIC Educational Resources Information Center

    Lee, Pai-Lin; Lan, William; Yen, Tung-Wen

    2011-01-01

    The study was designed to validate a model for a successful aging process and examine the gender differences in the aging process. Three hundred twelve participants who were 65 or older completed a Taiwan Social Change Survey that measures four factors that define successful aging process: including physical, psychological, social support, and…

  5. Estimating Neuronal Ageing with Hidden Markov Models

    NASA Astrophysics Data System (ADS)

    Wang, Bing; Pham, Tuan D.

    2011-06-01

    Neuronal degeneration is widely observed in normal ageing, meanwhile the neurode-generative disease like Alzheimer's disease effects neuronal degeneration in a faster way which is considered as faster ageing. Early intervention of such disease could benefit subjects with potentials of positive clinical outcome, therefore, early detection of disease related brain structural alteration is required. In this paper, we propose a computational approach for modelling the MRI-based structure alteration with ageing using hidden Markov model. The proposed hidden Markov model based brain structural model encodes intracortical tissue/fluid distribution using discrete wavelet transformation and vector quantization. Further, it captures gray matter volume loss, which is capable of reflecting subtle intracortical changes with ageing. Experiments were carried out on healthy subjects to validate its accuracy and robustness. Results have shown its ability of predicting the brain age with prediction error of 1.98 years without training data, which shows better result than other age predition methods.

  6. Stochastic and empirical models of the absolute asymmetric synthesis by the Soai-autocatalysis.

    PubMed

    Barabás, Béla; Zucchi, Claudia; Maioli, Marco; Micskei, Károly; Pályi, Gyula

    2015-02-01

    Absolute asymmetric synthesis (AAS) is the preparation of pure (or excess of one) enantiomer of a chiral compound from achiral precursor(s) by a chemical reaction, without enantiopure chiral additive and/or without applied asymmetric physical field. Only one well-characterized example of AAS is known today: the Soai-autocatalysis. In an attempt at clarification of the mechanism of this particular reaction we have undertaken empirical and stochastic analysis of several parallel AAS experiments. Our results show that the initial steps of the reaction might be controlled by simple normal distribution ("coin tossing") formalism. Advanced stages of the reaction, however, appear to be of a more complicated nature. Symmetric beta distribution formalism could not be brought into correspondence with the experimental observations. A bimodal beta distribution algorithm provided suitable agreement with the experimental data. The parameters of this bimodal beta function were determined by a Pólya-urn experiment (simulated by computer). Interestingly, parameters of the resulting bimodal beta function give a golden section ratio. These results show, that in this highly interesting autocatalysis two or even perhaps three catalytic cycles are cooperating. An attempt at constructing a "designed" Soai-type reaction system has also been made. PMID:25644371

  7. Calibration of models using groundwater age

    USGS Publications Warehouse

    Sanford, W.

    2011-01-01

    There have been substantial efforts recently by geochemists to determine the age of groundwater (time since water entered the system) and its uncertainty, and by hydrologists to use these data to help calibrate groundwater models. This essay discusses the calibration of models using groundwater age, with conclusions that emphasize what is practical given current limitations rather than theoretical possibilities.

  8. Aging behavior and lifetime modeling for polycarbonate

    SciTech Connect

    Kahlen, S.; Wallner, G.M.; Lang, R.W.

    2010-05-15

    In this paper, polycarbonate (PC) as a material candidate for solar absorber applications is investigated as to the aging behavior at different temperatures in air and water. The aging conditioning was performed in air in the temperature range from 120 to 140 C and in water between 70 and 95 C. Tensile tests were performed on unaged and aged PC film specimens at ambient temperature using strain-to-break values as a performance indicator for the degree of aging. For PC the effect of aging was found to strongly depend on the aging conditions. Activation energy based lifetime prediction models according to various methods described in the literature were applied. The activation energies and corresponding lifetime predictions for the temperature range from 40 to 60 C in water and from 90 to 110 C in air derived from these models are compared and interpreted as to their practical relevance. (author)

  9. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  10. Revised Absolute Configuration of Sibiricumin A: Substituent Effects in Simplified Model Structures Used for Quantum Mechanical Predictions of Chiroptical Properties.

    PubMed

    Zhao, Dan; Li, Zheng-Qiu; Cao, Fei; Liang, Miao-Miao; Pittman, Charles U; Zhu, Hua-Jie; Li, Li; Yu, Shi-Shan

    2016-08-01

    This study discusses the choice of different simplified models used in computations of electronic circular dichroism (ECD) spectra and other chiroptical characteristics used to determine the absolute configuration (AC) of the complex natural product sibiricumin A. Sections of molecules containing one chiral center with one near an aromatic group have large effects on the ECD spectra. Conversely, when the phenyl group is present on a substituent without a nonstereogenic center, removal of this section will have little effect on ECD spectra. However, these nonstereogenic-center-containing sections have large effects on calculated optical rotations (OR) values since the OR value is more sensitive to the geometries of sections in a molecule. In this study, the wrong AC of sibiricumin A was reassigned as (7R,8S,1'R,7'R,8'S)-. Chirality 28:612-617, 2016. © 2016 Wiley Periodicals, Inc. PMID:27428019

  11. A 2015 International Geomagnetic Reference Field (IGRF) candidate model based on Swarm's experimental absolute magnetometer vector mode data

    NASA Astrophysics Data System (ADS)

    Vigneron, Pierre; Hulot, Gauthier; Olsen, Nils; Léger, Jean-Michel; Jager, Thomas; Brocco, Laura; Sirol, Olivier; Coïsson, Pierdavide; Lalanne, Xavier; Chulliat, Arnaud; Bertrand, François; Boness, Axel; Fratter, Isabelle

    2015-06-01

    Each of the three satellites of the European Space Agency Swarm mission carries an absolute scalar magnetometer (ASM) that provides the nominal 1-Hz scalar data of the mission for both science and calibration purposes. These ASM instruments, however, also deliver autonomous 1-Hz experimental vector data. Here, we report on how ASM-only scalar and vector data from the Alpha and Bravo satellites between November 29, 2013 (a week after launch) and September 25, 2014 (for on-time delivery of the model on October 1, 2014) could be used to build a very valuable candidate model for the 2015.0 International Geomagnetic Reference Field (IGRF). A parent model was first computed, describing the geomagnetic field of internal origin up to degree and order 40 in a spherical harmonic representation and including a constant secular variation up to degree and order 8. This model was next simply forwarded to epoch 2015.0 and truncated at degree and order 13. The resulting ASM-only 2015.0 IGRF candidate model is compared to analogous models derived from the mission's nominal data and to the now-published final 2015.0 IGRF model. Differences among models mainly highlight uncertainties enhanced by the limited geographical distribution of the selected data set (essentially due to a lack of availability of data at high northern latitude satisfying nighttime conditions at the end of the time period considered). These appear to be comparable to differences classically observed among IGRF candidate models. These positive results led the ASM-only 2015.0 IGRF candidate model to contribute to the construction of the final 2015.0 IGRF model.

  12. A Model of Spirituality for Ageing Muslims.

    PubMed

    Ahmad, Mahjabeen; Khan, Shamsul

    2016-06-01

    Spirituality's influence on general well-being and its association with healthy ageing has been studied extensively. However, a different perspective has to be brought in when dealing with spirituality issues of ageing Muslims. Central to this perspective is the intertwining of religion and spirituality in Islam. This article will contribute to the understanding of the nature of Islamic spirituality and its immense importance in the life of a practicing ageing Muslim. Consequently, it will help care providers to include appropriate spiritual care in the care repertoire of a Muslim care recipient. It is assumed that the framework for a model of spirituality based on Islamic religious beliefs would help contextualise the relationship between spirituality and ageing Muslims. Not only challenges, but also the opportunities that old age provides for charting the spiritual journey have underpinned this model. PMID:25822881

  13. The Dynamics of Scaling: A Memory-Based Anchor Model of Category Rating and Absolute Identification

    ERIC Educational Resources Information Center

    Petrov, Alexander A.; Anderson, John R.

    2005-01-01

    A memory-based scaling model--ANCHOR--is proposed and tested. The perceived magnitude of the target stimulus is compared with a set of anchors in memory. Anchor selection is probabilistic and sensitive to similarity, base-level strength, and recency. The winning anchor provides a reference point near the target and thereby converts the global…

  14. A probabilistic model of absolute auditory thresholds and its possible physiological basis.

    PubMed

    Heil, Peter; Neubauer, Heinrich; Tetschke, Manuel; Irvine, Dexter R F

    2013-01-01

    Detection thresholds for auditory stimuli, specified in terms of their -amplitude or level, depend on the stimulus temporal envelope and decrease with increasing stimulus duration. The neural mechanisms underlying these fundamental across-species observations are not fully understood. Here, we present a "continuous look" model, according to which the stimulus gives rise to stochastic neural detection events whose probability of occurrence is proportional to the 3rd power of the low-pass filtered, time-varying stimulus amplitude. Threshold is reached when a criterion number of events have occurred (probability summation). No long-term integration is required. We apply the model to an extensive set of thresholds measured in humans for tones of different envelopes and durations and find it to fit well. Subtle differences at long durations may be due to limited attention resources. We confirm the probabilistic nature of the detection events by analyses of simple reaction times and verify the exponent of 3 by validating model predictions for binaural thresholds from monaural thresholds. The exponent originates in the auditory periphery, possibly in the intrinsic Ca(2+) cooperativity of the Ca(2+) sensor involved in exocytosis from inner hair cells. It results in growth of the spike rate of auditory-nerve fibers (ANFs) with the 3rd power of the stimulus amplitude before saturating (Heil et al., J Neurosci 31:15424-15437, 2011), rather than with its square (i.e., with stimulus intensity), as is commonly assumed. Our work therefore suggests a link between detection thresholds and a key biochemical reaction in the receptor cells. PMID:23716205

  15. Rodent models of aging bone: an update.

    PubMed

    Syed, Farhan A; Melim, Terry

    2011-12-01

    With an increase in the average life span especially in the Western hemisphere, there is renewed interest in treating maladies of old age including osteoporosis. Age-related bone loss and resultant osteoporosis substantially increase risk of fractures and morbidity in the geriatric population leading to both a decline in the quality of life for the elderly as well as a substantial burden on the health care system. Herein, we review recent research in murine and rodent models looking at how both extrinsic and intrinsic factors such as hormones, biochemicals, neuromodulators, inflammatory cytokines, oxidative stress, nutrition, and exercise influence the skeleton with age. Recent studies on the relationship between bone and fat in the marrow, and the fate of the marrow mesenchymal stromal cell population, which can give rise to either bone-forming osteoblasts or fat-forming adipocytic cells as a function of age, have also been highlighted. An appreciable range of studies using aging murine as well as cellular models are discussed, as these studies have broadened our understanding of the pathways and players in the aging bone. Impactful information regarding aging and the bone may then allow the application of better pharmacologic as well as nonpharmacologic regimens to alleviate bone loss due to aging. PMID:21918858

  16. Inherently mass-conservative version of the semi-Lagrangian Absolute Vorticity (SL-AV) atmospheric model dynamical core

    NASA Astrophysics Data System (ADS)

    Shashkin, V. V.; Tolstykh, M. A.

    2013-09-01

    The semi-Lagrangian Absolute Vorticity (SL-AV) atmospheric model is the global semi-Lagrangian hydrostatic model used for operational medium-range and seasonal forecasts at Hydrometeorological centre of Russia. The distinct feature of SL-AV dynamical core is the semi-implicit semi-Lagrangian vorticity-divergence formulation on the unstaggered grid. Semi-implicit semi-Lagrangian approach allows for long time steps while violates the global and local mass-conservation. In particular, the total mass in simulations with semi-Lagrangian models can drift significantly if no aposteriori mass-fixing algorithms are applied. However, the global mass-fixing algorithms degrade the local mass conservation. The inherently mass-conservative version of SL-AV model dynamical core presented in the article ensures global and local mass conservation without mass-fixing algorithms. The mass conservation is achieved with the introduction of the finite-volume semi-Lagrangian discretization for continuity equation based on the 3-D extension of the conservative cascade semi-Lagrangian transport scheme (CCS). The numerical experiments show that the presented new version of SL-AV dynamical core combines the accuracy and stability of the standard SL-AV dynamical core with the mass-conservation properties. The results of the mountain induced Rossby wave test and baroclinic instability test for mass-conservative dynamical core are found to be in agreement with the results available in literature.

  17. Inherently mass-conservative version of the semi-Lagrangian absolute vorticity (SL-AV) atmospheric model dynamical core

    NASA Astrophysics Data System (ADS)

    Shashkin, V. V.; Tolstykh, M. A.

    2014-02-01

    The semi-Lagrangian absolute vorticity (SL-AV) atmospheric model is the global semi-Lagrangian hydrostatic model used for operational medium-range and seasonal forecasts at the Hydrometeorological Centre of Russia. The distinct feature of the SL-AV dynamical core is the semi-implicit, semi-Lagrangian vorticity-divergence formulation on the unstaggered grid. A semi-implicit, semi-Lagrangian approach allows for long time steps but violates the global and local mass conservation. In particular, the total mass in simulations with semi-Lagrangian models can drift significantly if no a posteriori mass-fixing algorithm is applied. However, the global mass-fixing algorithms degrade the local mass conservation. The new inherently mass-conservative version of the SL-AV model dynamical core presented here ensures global and local mass conservation without mass-fixing algorithms. The mass conservation is achieved with the introduction of the finite-volume, semi-Lagrangian discretization for a continuity equation based on the 3-D extension of the conservative cascade semi-Lagrangian transport scheme (CCS). Numerical experiments show that the new version of the SL-AV dynamical core presented combines the accuracy and stability of the standard SL-AV dynamical core with the mass-conservation properties. The results of the mountain-induced Rossby-wave test and baroclinic instability test for the mass-conservative dynamical core are found to be in agreement with the results available in the literature.

  18. Dependency of slab geometry on absolute velocities and conditions for cyclicity: insights from numerical modelling

    NASA Astrophysics Data System (ADS)

    Gibert, G.; Gerbault, M.; Hassani, R.; Tric, E.

    2012-05-01

    The aim of this study is to quantify the relationship between the kinematics of subduction, deformation in the overriding plate and the evolution of slab geometry. A 2-D finite element numerical code is used, and a first objective consists in benchmarking previously published analogue models. Far-field plate velocities are applied, and once the subducting plate reaches the 660 km discontinuity, modelled as a rigid base, we obtain two different forms or styles of subduction that depend on the overriding plate velocity vop: if vop > 0, the slab lies forwards on the 660 km discontinuity (style 1), and if vop≤ 0, the slab lies backwards on the discontinuity (style 2). We also obtain a cyclic pattern with the slab folding on itself repeatedly when vsp > 0 and 2vop+vsp > 0 (where vsp is the subducting plate velocity). These conditions result from the analysis of several simulations in which the subduction velocities and plate viscosities are varied. When the slab periodically folds on the 660 km discontinuity, periods of shallow slab dip and compression in the overriding plate are followed by periods of slab steepening and relative extension in the overriding plate. Folding periodicity is controlled by the slab viscosity and subduction velocity. When a low-viscosity zone is included in the overriding plate, the trench motion is effectively decoupled from the overriding plate velocity, therefore allowing it to be directly controlled by the deep dynamics of the slab. For the cyclic style 2 corresponding to forward folding of the slab, the low-viscosity region in the overriding plate increases the stress amplitudes oscillations, the trench motion and the folding periodicity with time. Therefore the strength of the entire overriding plate is shown to directly control the dynamics of subduction. Using the Nazca and South American plate velocities we produce models of cyclic folding with a period of ca. 22 Ma and a minimal dip angle of ca. 10°. Episodic folding of the slab

  19. Pathology of Mouse Models of Accelerated Aging.

    PubMed

    Harkema, L; Youssef, S A; de Bruin, A

    2016-03-01

    Progeroid mouse models display phenotypes in multiple organ systems that suggest premature aging and resemble features of natural aging of both mice and humans. The prospect of a significant increase in the global elderly population within the next decades has led to the emergence of "geroscience," which aims at elucidating the molecular mechanisms involved in aging. Progeroid mouse models are frequently used in geroscience as they provide insight into the molecular mechanisms that are involved in the highly complex process of natural aging. This review provides an overview of the most commonly reported nonneoplastic macroscopic and microscopic pathologic findings in progeroid mouse models (eg, osteoporosis, osteoarthritis, degenerative joint disease, intervertebral disc degeneration, kyphosis, sarcopenia, cutaneous atrophy, wound healing, hair loss, alopecia, lymphoid atrophy, cataract, corneal endothelial dystrophy, retinal degenerative diseases, and vascular remodeling). Furthermore, several shortcomings in pathologic analysis and descriptions of these models are discussed. Progeroid mouse models are valuable models for aging, but thorough knowledge of both the mouse strain background and the progeria-related phenotype is required to guide interpretation and translation of the pathology data. PMID:26864891

  20. Species ages in neutral biodiversity models.

    PubMed

    Chisholm, Ryan A; O'Dwyer, James P

    2014-05-01

    Biogeography seeks to understand the mechanisms that drive biodiversity across long temporal and large spatial scales. Theoretical models of biogeography can be tested by comparing their predictions of quantities such as species ages against empirical estimates. It has previously been claimed that the neutral theory of biodiversity and biogeography predicts species ages that are unrealistically long. Any improved theory of biodiversity must rectify this problem, but first it is necessary to quantify the problem precisely. Here we provide analytical expressions for species ages in neutral biodiversity communities. We analyse a spatially implicit metacommunity model and solve for both the zero-sum and non-zero-sum cases. We explain why our new expressions are, in the context of biodiversity, usually more appropriate than those previously imported from neutral molecular evolution. Because of the time symmetry of the spatially implicit neutral model, our expressions also lead directly to formulas for species persistence times and species lifetimes. We use our new expressions to estimate species ages of forest trees under a neutral model and find that they are about an order of magnitude shorter than those predicted previously but still unrealistically long. In light of our results, we discuss different models of biogeography that may solve the problem of species ages. PMID:24530891

  1. Decent wage is more important than absolution of debts: A smallholder socio-hydrological modelling framework

    NASA Astrophysics Data System (ADS)

    Pande, Saket; Savenije, Hubert

    2015-04-01

    We present a framework to understand the socio-hydrological system dynamics of a small holder. Small holders are farmers who own less than 2 ha of farmland. It couples the dynamics of 6 main variables that are most relevant at the scale of a small holder: local storage (soil moisture and other water storage), capital, knowledge, livestock production, soil fertility and grass biomass production. The hydroclimatic variability is at sub-annual scale and influences the socio-hydrology at annual scale. The model incorporates rule-based adaptation mechanisms (for example: adjusting expenditures on food and fertilizers, selling livestocks etc.) of small holders when they face adverse socio-hydrological conditions, such as low annual rainfall, higher intra-annual variability in rainfall or variability in agricultural prices. We apply the framework to understand the socio-hydrology of a sugarcane small holder in Aurangabad, Maharashtra. This district has witnessed suicides of many sugarcane farmers who could not extricate themselves out of the debt trap. These farmers lack irrigation and are susceptible to fluctuating sugar prices and intra-annual hydro-climatic variability. We study the sensitivity of annual total capital averaged over 30 years, an indicator of small holder wellbeing, to initial capital that a small holder starts with and the prevalent wage rates. We find that a smallholder well being is low (below Rs 30000 per annum, a threshold above which a smallholder can afford a basic standard of living) and is rather insensitive to initial capital at low wage rates. Initial capital perhaps matters to small holder livelihoods at higher wage rates. Further, the small holder system appears to be resilient at around Rs 115/mandays in the sense that small perturbations in wage rates around this rate still sustains the smallholder above the basic standard of living. Our results thus indicate that government intervention to absolve the debt of farmers is not enough. It

  2. Comparing Absolute Error with Squared Error for Evaluating Empirical Models of Continuous Variables: Compositions, Implications, and Consequences

    NASA Astrophysics Data System (ADS)

    Gao, J.

    2014-12-01

    Reducing modeling error is often a major concern of empirical geophysical models. However, modeling errors can be defined in different ways: When the response variable is continuous, the most commonly used metrics are squared (SQ) and absolute (ABS) errors. For most applications, ABS error is the more natural, but SQ error is mathematically more tractable, so is often used as a substitute with little scientific justification. Existing literature has not thoroughly investigated the implications of using SQ error in place of ABS error, especially not geospatially. This study compares the two metrics through the lens of bias-variance decomposition (BVD). BVD breaks down the expected modeling error of each model evaluation point into bias (systematic error), variance (model sensitivity), and noise (observation instability). It offers a way to probe the composition of various error metrics. I analytically derived the BVD of ABS error and compared it with the well-known SQ error BVD, and found that not only the two metrics measure the characteristics of the probability distributions of modeling errors differently, but also the effects of these characteristics on the overall expected error are different. Most notably, under SQ error all bias, variance, and noise increase expected error, while under ABS error certain parts of the error components reduce expected error. Since manipulating these subtractive terms is a legitimate way to reduce expected modeling error, SQ error can never capture the complete story embedded in ABS error. I then empirically compared the two metrics with a supervised remote sensing model for mapping surface imperviousness. Pair-wise spatially-explicit comparison for each error component showed that SQ error overstates all error components in comparison to ABS error, especially variance-related terms. Hence, substituting ABS error with SQ error makes model performance appear worse than it actually is, and the analyst would more likely accept a

  3. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  4. Mathematical Modelling of Metabolic Regulation in Aging

    PubMed Central

    Mc Auley, Mark T.; Mooney, Kathleen M.; Angell, Peter J.; Wilkinson, Stephen J.

    2015-01-01

    The underlying cellular mechanisms that characterize aging are complex and multifaceted. However, it is emerging that aging could be regulated by two distinct metabolic hubs. These hubs are the pathway defined by the mammalian target of rapamycin (mTOR) and that defined by the NAD+-dependent deacetylase enzyme, SIRT1. Recent experimental evidence suggests that there is crosstalk between these two important pathways; however, the mechanisms underpinning their interaction(s) remains poorly understood. In this review, we propose using computational modelling in tandem with experimentation to delineate the mechanism(s). We briefly discuss the main modelling frameworks that could be used to disentangle this relationship and present a reduced reaction pathway that could be modelled. We conclude by outlining the limitations of computational modelling and by discussing opportunities for future progress in this area. PMID:25923415

  5. Mathematical modelling of metabolic regulation in aging.

    PubMed

    Auley, Mark T Mc; Mooney, Kathleen M; Angell, Peter J; Wilkinson, Stephen J

    2015-01-01

    The underlying cellular mechanisms that characterize aging are complex and multifaceted. However, it is emerging that aging could be regulated by two distinct metabolic hubs. These hubs are the pathway defined by the mammalian target of rapamycin (mTOR) and that defined by the NAD+-dependent deacetylase enzyme, SIRT1. Recent experimental evidence suggests that there is crosstalk between these two important pathways; however, the mechanisms underpinning their interaction(s) remains poorly understood. In this review, we propose using computational modelling in tandem with experimentation to delineate the mechanism(s). We briefly discuss the main modelling frameworks that could be used to disentangle this relationship and present a reduced reaction pathway that could be modelled. We conclude by outlining the limitations of computational modelling and by discussing opportunities for future progress in this area. PMID:25923415

  6. The reaction H + C4H2 - Absolute rate constant measurement and implication for atmospheric modeling of Titan

    NASA Astrophysics Data System (ADS)

    Nava, D. F.; Mitchell, M. B.; Stief, L. J.

    1986-04-01

    The absolute rate constant for the reaction H + C4H2 has been measured over the temperature (T) interval 210-423 K, using the technique of flash photolysis-resonance fluorescence. At each of the five temperatures employed, the results were independent of variations in C4H2 concentration, total pressure of Ar or N2, and flash intensity (i.e., the initial H concentration). The rate constant, k, was found to be equal to 1.39 x 10 to the -10th exp (-1184/T) cu cm/s, with an error of one standard deviation. The Arrhenius parameters at the high pressure limit determined here for the H + C4H2 reaction are consistent with those for the corresponding reactions of H with C2H2 and C3H4. Implications of the kinetic carbon chemistry results, particularly those at low temperature, are considered for models of the atmospheric carbon chemistry of Titan. The rate of this reaction, relative to that of the analogous, but slower, reaction of H + C2H2, appears to make H + C4H2 a very feasible reaction pathway for effective conversion of H atoms to molecular hydrogen in the stratosphere of Titan.

  7. Love Kills:. Simulations in Penna Ageing Model

    NASA Astrophysics Data System (ADS)

    Stauffer, Dietrich; Cebrat, Stanisław; Penna, T. J. P.; Sousa, A. O.

    The standard Penna ageing model with sexual reproduction is enlarged by adding additional bit-strings for love: Marriage happens only if the male love strings are sufficiently different from the female ones. We simulate at what level of required difference the population dies out.

  8. Modeling and measuring extravascular hemoglobin: aging contusions

    NASA Astrophysics Data System (ADS)

    Lines, Collin; Kim, Oleg; Duffy, Susan; Alber, Mark; Crawford, Gregory P.

    2011-07-01

    Medical expertise is frequently elicited to aid in determining the age and the cause of the trauma or injury. Child protection and law enforcement frequently rely on the physical assessment of the trauma which involves delineating intentional from unintentional types of trauma. Recent studies have shown that current methods to assess the age of traumatic injuries are highly inaccurate and do not give reasonable predictions. Hemoglobin is one of the strongest chromophores in human tissues. Transport of hemoglobin and its breakdown products in tissue determines the spectrophotometric characteristics of the skin and its variations in time. Therefore, measurements of diffuse reflective spectra of the skin allow noninvasive screening. This paper reviews potential transmission and diffusive reflection spectroscopy based techniques and predictive and quantitative modeling methods assisting in efficient retrieval of the age of extravascular contusions. This paper then presents a novel Monte Carlo technique for 3D photon tracking and blood transport model. In future studies, clinically obtained spectra will be used to validate the model as well as fine-tune coefficients for absorption. It is the goal of this study to develop a model that would allow a non-invasive, accurate determination of the age of a bruise.

  9. Constraining the Absolute Orientation of eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission

    NASA Technical Reports Server (NTRS)

    Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.

    2011-01-01

    We present a three-dimensional (3-D) dynamical model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA(theta) that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38deg, and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i approx. = 130deg to 145deg, Theta approx. = -15deg to +30deg, and an orbital axis projected on the sky at a P A approx. = 302deg to 327deg east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3-D. The companion star, Eta(sub B), thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modeling to determine the stellar masses.

  10. Normal brain ageing: models and mechanisms

    PubMed Central

    Toescu, Emil C

    2005-01-01

    Normal ageing is associated with a degree of decline in a number of cognitive functions. Apart from the issues raised by the current attempts to expand the lifespan, understanding the mechanisms and the detailed metabolic interactions involved in the process of normal neuronal ageing continues to be a challenge. One model, supported by a significant amount of experimental evidence, views the cellular ageing as a metabolic state characterized by an altered function of the metabolic triad: mitochondria–reactive oxygen species (ROS)–intracellular Ca2+. The perturbation in the relationship between the members of this metabolic triad generate a state of decreased homeostatic reserve, in which the aged neurons could maintain adequate function during normal activity, as demonstrated by the fact that normal ageing is not associated with widespread neuronal loss, but become increasingly vulnerable to the effects of excessive metabolic loads, usually associated with trauma, ischaemia or neurodegenerative processes. This review will concentrate on some of the evidence showing altered mitochondrial function with ageing and also discuss some of the functional consequences that would result from such events, such as alterations in mitochondrial Ca2+ homeostasis, ATP production and generation of ROS. PMID:16321805

  11. Hydra, a powerful model for aging studies

    PubMed Central

    Tomczyk, Szymon; Fischer, Kathleen; Austad, Steven; Galliot, Brigitte

    2015-01-01

    Cnidarian Hydra polyps escape senescence, most likely due to the robust activity of their three stem cell populations. These stem cells continuously self-renew in the body column and differentiate at the extremities following a tightly coordinated spatial pattern. Paul Brien showed in 1953 that in one particular species, Hydra oligactis, cold-dependent sexual differentiation leads to rapid aging and death. Here, we review the features of this inducible aging phenotype. These cellular alterations, detected several weeks after aging was induced, are characterized by a decreasing density of somatic interstitial cell derivatives, a disorganization of the apical nervous system, and a disorganization of myofibers of the epithelial cells. Consequently, tissue replacement required to maintain homeostasis, feeding behavior, and contractility of the animal are dramatically affected. Interestingly, this aging phenotype is not observed in all H. oligactis strains, thus providing a powerful experimental model for investigations of the genetic control of aging. Given the presence in the cnidarian genome of a large number of human orthologs that have been lost in ecdysozoans, such approaches might help uncover novel regulators of aging in vertebrates. PMID:26120246

  12. Animal models of age related macular degeneration

    PubMed Central

    Pennesi, Mark E.; Neuringer, Martha; Courtney, Robert J.

    2013-01-01

    Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations. PMID:22705444

  13. Using Multivariate Regression Model with Least Absolute Shrinkage and Selection Operator (LASSO) to Predict the Incidence of Xerostomia after Intensity-Modulated Radiotherapy for Head and Neck Cancer

    PubMed Central

    Ting, Hui-Min; Chang, Liyun; Huang, Yu-Jie; Wu, Jia-Ming; Wang, Hung-Yu; Horng, Mong-Fong; Chang, Chun-Ming; Lan, Jen-Hong; Huang, Ya-Yu; Fang, Fu-Min; Leung, Stephen Wan

    2014-01-01

    Purpose The aim of this study was to develop a multivariate logistic regression model with least absolute shrinkage and selection operator (LASSO) to make valid predictions about the incidence of moderate-to-severe patient-rated xerostomia among head and neck cancer (HNC) patients treated with IMRT. Methods and Materials Quality of life questionnaire datasets from 206 patients with HNC were analyzed. The European Organization for Research and Treatment of Cancer QLQ-H&N35 and QLQ-C30 questionnaires were used as the endpoint evaluation. The primary endpoint (grade 3+ xerostomia) was defined as moderate-to-severe xerostomia at 3 (XER3m) and 12 months (XER12m) after the completion of IMRT. Normal tissue complication probability (NTCP) models were developed. The optimal and suboptimal numbers of prognostic factors for a multivariate logistic regression model were determined using the LASSO with bootstrapping technique. Statistical analysis was performed using the scaled Brier score, Nagelkerke R2, chi-squared test, Omnibus, Hosmer-Lemeshow test, and the AUC. Results Eight prognostic factors were selected by LASSO for the 3-month time point: Dmean-c, Dmean-i, age, financial status, T stage, AJCC stage, smoking, and education. Nine prognostic factors were selected for the 12-month time point: Dmean-i, education, Dmean-c, smoking, T stage, baseline xerostomia, alcohol abuse, family history, and node classification. In the selection of the suboptimal number of prognostic factors by LASSO, three suboptimal prognostic factors were fine-tuned by Hosmer-Lemeshow test and AUC, i.e., Dmean-c, Dmean-i, and age for the 3-month time point. Five suboptimal prognostic factors were also selected for the 12-month time point, i.e., Dmean-i, education, Dmean-c, smoking, and T stage. The overall performance for both time points of the NTCP model in terms of scaled Brier score, Omnibus, and Nagelkerke R2 was satisfactory and corresponded well with the expected values. Conclusions

  14. A life span model of successful aging.

    PubMed

    Schulz, R; Heckhausen, J

    1996-07-01

    To lay the foundation for our model, we first describe existing conceptions of successful aging, underlying assumptions of development, and criteria for success. The model presented extends the discourse on this topic in three directions: (a) It frames the discussion of successful aging in the broader context of life course development; (b) it accounts for both normative and nonnormative (i.e., exceptional) success; and (c) it integrates motivational processes into a theory of successful aging. Successful aging is equated with the development and maintenance of primary control throughout the life course, which is achieved through control-related processes that optimize selection and failure compensation functions. Selection processes regulate the choice of action goals so that diversity is maintained and positive and negative trade-offs between performance domains and life stages are taken into account. Compensation mechanisms serve to maintain, enhance, and remediate competencies and motivational resources after failure experiences. Both compensation and selection processes are motivated by desires for primary control and can be characterized in terms of primary and secondary control processes. PMID:8694390

  15. Methodology to predict long-term cancer survival from short-term data using Tobacco Cancer Risk and Absolute Cancer Cure models

    NASA Astrophysics Data System (ADS)

    Mould, R. F.; Lederman, M.; Tai, P.; Wong, J. K. M.

    2002-11-01

    Three parametric statistical models have been fully validated for cancer of the larynx for the prediction of long-term 15, 20 and 25 year cancer-specific survival fractions when short-term follow-up data was available for just 1-2 years after the end of treatment of the last patient. In all groups of cases the treatment period was only 5 years. Three disease stage groups were studied, T1N0, T2N0 and T3N0. The models are the Standard Lognormal (SLN) first proposed by Boag (1949 J. R. Stat. Soc. Series B 11 15-53) but only ever fully validated for cancer of the cervix, Mould and Boag (1975 Br. J. Cancer 32 529-50), and two new models which have been termed Tobacco Cancer Risk (TCR) and Absolute Cancer Cure (ACC). In each, the frequency distribution of survival times of defined groups of cancer deaths is lognormally distributed: larynx only (SLN), larynx and lung (TCR) and all cancers (ACC). All models each have three unknown parameters but it was possible to estimate a value for the lognormal parameter S a priori. By reduction to two unknown parameters the model stability has been improved. The material used to validate the methodology consisted of case histories of 965 patients, all treated during the period 1944-1968 by Dr Manuel Lederman of the Royal Marsden Hospital, London, with follow-up to 1988. This provided a follow-up range of 20- 44 years and enabled predicted long-term survival fractions to be compared with the actual survival fractions, calculated by the Kaplan and Meier (1958 J. Am. Stat. Assoc. 53 457-82) method. The TCR and ACC models are better than the SLN model and for a maximum short-term follow-up of 6 years, the 20 and 25 year survival fractions could be predicted. Therefore the numbers of follow-up years saved are respectively 14 years and 19 years. Clinical trial results using the TCR and ACC models can thus be analysed much earlier than currently possible. Absolute cure from cancer was also studied, using not only the prediction models which

  16. Eosinophil count - absolute

    MedlinePlus

    Eosinophils; Absolute eosinophil count ... the white blood cell count to give the absolute eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...

  17. Constraining the absolute orientation of η Carinae's binary orbit: a 3D dynamical model for the broad [Fe III] emission

    NASA Astrophysics Data System (ADS)

    Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.

    2012-03-01

    We present a three-dimensional (3D) dynamical model for the broad [Fe III] emission observed in η Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (STIS). This model is based on full 3D smoothed particle hydrodynamics simulations of η Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectroimages of [Fe III] emission-line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA θ that the orbital plane projection of the line of sight makes with the apastron side of the semimajor axis and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3D orientation of the binary orbit. To simultaneously reproduce the blueshifted emission arcs observed at orbital phase 0.976, STIS slit PA =+38° and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i≈ 130° to 145°, θ≈-15° to +30° and an orbital axis projected on the sky at a PA ≈ 302° to 327° east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3D. The companion star, ηB, thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modelling to determine the stellar masses. Footnotes<label>1</label>Low- and high-ionization refer here to atomic species with ionizations potentials (IPs) below and above the IP of hydrogen, 13.6 eV.<label>2</label>Measured in degrees from north to east.<label>3</label>θ is the same as the angle φ defined in fig. 3 of O08.<label>4</label>The outer edge looks circular only because this marks the edge of the spherical computational domain of the SPH simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1028098','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1028098"><span id="translatedtitle">Atmospheric Longwave Irradiance Uncertainty: Pyrgeometers Compared to an <span class="hlt">Absolute</span> Sky-Scanning Radiometer, Atmospheric Emitted Radiance Interferometer, and Radiative Transfer <span class="hlt">Model</span> Calculations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Philipona, J. R.; Dutton, Ellsworth G.; Stoffel, T.; Michalsky, Joseph J.; Reda, I.; Stifter, Armin; Wendling, Peter; Wood, Norm; Clough, Shepard A.; Mlawer, Eli J.; Anderson, Gail; Revercomb, Henry E.; Shippert, Timothy R.</p> <p>2001-06-04</p> <p>Because atmospheric longwave radiation is one of the most fundamental elements of an expected climate change, there has been a strong interest in improving measurements and <span class="hlt">model</span> calculations in recent years. Important questions are how reliable and consistent are atmospheric longwave radiation measurements and calculations and what are the uncertainties? The First International Pyrgeometer and <span class="hlt">Absolute</span> Sky-scanning Radiometer Comparison, which was held at the Atmospheric Radiation Measurement program's Souther Great Plains site in Oklahoma, answers these questions at least for midlatitude summer conditions and reflects the state of the art for atmospheric longwave radiation measurements and calculations. The 15 participating pyrgeometers were all calibration-traced standard instruments chosen from a broad international community. Two new chopped pyrgeometers also took part in the comparison. And <span class="hlt">absolute</span> sky-scanning radiometer (ASR), which includes a pyroelectric detector and a reference blackbody source, was used for the first time as a reference standard instrument to field calibrate pyrgeometers during clear-sky nighttime measurements. Owner-provided and uniformly determined blackbody calibration factors were compared. Remarkable improvements and higher pyrgeometer precision were achieved with field calibration factors. Results of nighttime and daytime pyrgeometer precision and <span class="hlt">absolute</span> uncertainty are presented for eight consecutive days of measurements, during which period downward longwave irradiance varied between 260 and 420 W m-2. Comparisons between pyrgeometers and the <span class="hlt">absolute</span> ASR, the atmospheric emitted radiance interferometer, and radiative transfer <span class="hlt">models</span> LBLRTM and MODTRAN show a surprisingly good agreement of <2 W m-2 for nighttime atmospheric longwave irradiance measurements and calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4669521','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4669521"><span id="translatedtitle">A novel strategy for forensic <span class="hlt">age</span> prediction by DNA methylation and support vector regression <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Cheng; Qu, Hongzhu; Wang, Guangyu; Xie, Bingbing; Shi, Yi; Yang, Yaran; Zhao, Zhao; Hu, Lan; Fang, Xiangdong; Yan, Jiangwei; Feng, Lei</p> <p>2015-01-01</p> <p>High deviations resulting from prediction <span class="hlt">model</span>, gender and population difference have limited <span class="hlt">age</span> estimation application of DNA methylation markers. Here we identified 2,957 novel <span class="hlt">age</span>-associated DNA methylation sites (P < 0.01 and R2 > 0.5) in blood of eight pairs of Chinese Han female monozygotic twins. Among them, nine novel sites (false discovery rate < 0.01), along with three other reported sites, were further validated in 49 unrelated female volunteers with <span class="hlt">ages</span> of 20–80 years by Sequenom Massarray. A total of 95 CpGs were covered in the PCR products and 11 of them were built the <span class="hlt">age</span> prediction <span class="hlt">models</span>. After comparing four different <span class="hlt">models</span> including, multivariate linear regression, multivariate nonlinear regression, back propagation neural network and support vector regression, SVR was identified as the most robust <span class="hlt">model</span> with the least mean <span class="hlt">absolute</span> deviation from real chronological <span class="hlt">age</span> (2.8 years) and an average accuracy of 4.7 years predicted by only six loci from the 11 loci, as well as an less cross-validated error compared with linear regression <span class="hlt">model</span>. Our novel strategy provides an accurate measurement that is highly useful in estimating the individual <span class="hlt">age</span> in forensic practice as well as in tracking the <span class="hlt">aging</span> process in other related applications. PMID:26635134</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22340019','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22340019"><span id="translatedtitle"><span class="hlt">Absolute</span> properties of the eclipsing binary system AQ Serpentis: A stringent test of convective core overshooting in stellar evolution <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Torres, Guillermo; Vaz, Luiz Paulo R.; Sandberg Lacy, Claud H.; Claret, Antonio E-mail: lpv@fisica.ufmg.br E-mail: claret@iaa.es</p> <p>2014-02-01</p> <p>We report differential photometric observations and radial-velocity measurements of the detached, 1.69 day period, double-lined eclipsing binary AQ Ser. Accurate masses and radii for the components are determined to better than 1.8% and 1.1%, respectively, and are M {sub 1} = 1.417 ± 0.021 M {sub ☉}, M {sub 2} = 1.346 ± 0.024 M {sub ☉}, R {sub 1} = 2.451 ± 0.027 R {sub ☉}, and R {sub 2} = 2.281 ± 0.014 R {sub ☉}. The temperatures are 6340 ± 100 K (spectral type F6) and 6430 ± 100 K (F5), respectively. Both stars are considerably evolved, such that predictions from stellar evolution theory are particularly sensitive to the degree of extra mixing above the convective core (overshoot). The component masses are different enough to exclude a location in the H-R diagram past the point of central hydrogen exhaustion, which implies the need for extra mixing. Moreover, we find that current main-sequence <span class="hlt">models</span> are unable to match the observed properties at a single <span class="hlt">age</span> even when allowing the unknown metallicity, mixing length parameter, and convective overshooting parameter to vary freely and independently for the two components. The <span class="hlt">age</span> of the more massive star appears systematically younger. AQ Ser and other similarly evolved eclipsing binaries showing the same discrepancy highlight an outstanding and largely overlooked problem with the description of overshooting in current stellar theory.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4453283','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4453283"><span id="translatedtitle">Towards an Analytical <span class="hlt">Age</span>-Dependent <span class="hlt">Model</span> of Contrast Sensitivity Functions for an <span class="hlt">Ageing</span> Society</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Joulan, Karine; Brémond, Roland</p> <p>2015-01-01</p> <p>The Contrast Sensitivity Function (CSF) describes how the visibility of a grating depends on the stimulus spatial frequency. Many published CSF data have demonstrated that contrast sensitivity declines with <span class="hlt">age</span>. However, an <span class="hlt">age</span>-dependent analytical <span class="hlt">model</span> of the CSF is not available to date. In this paper, we propose such an analytical CSF <span class="hlt">model</span> based on visual mechanisms, taking into account the <span class="hlt">age</span> factor. To this end, we have extended an existing <span class="hlt">model</span> from Barten (1999), taking into account the dependencies of this <span class="hlt">model</span>'s optical and physiological parameters on <span class="hlt">age</span>. <span class="hlt">Age</span>-dependent <span class="hlt">models</span> of the cones and ganglion cells densities, the optical and neural MTF, and optical and neural noise are proposed, based on published data. The proposed <span class="hlt">age</span>-dependent CSF is finally tested against available experimental data, with fair results. Such an <span class="hlt">age</span>-dependent <span class="hlt">model</span> may be beneficial when designing real-time <span class="hlt">age</span>-dependent image coding and display applications. PMID:26078994</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=challenges+AND+diversity+AND+workplace&pg=5&id=ED464749','ERIC'); return false;" href="http://eric.ed.gov/?q=challenges+AND+diversity+AND+workplace&pg=5&id=ED464749"><span id="translatedtitle">Creating Better School-<span class="hlt">Age</span> Care Jobs: <span class="hlt">Model</span> Work Standards.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Haack, Peggy</p> <p></p> <p>Built on the premise that good school-<span class="hlt">age</span> care jobs are the cornerstone of high-quality services for school-<span class="hlt">age</span> youth and their families, this guide presents <span class="hlt">model</span> work standards for school-<span class="hlt">age</span> care providers. The guide begins with a description of the strengths and challenges of the school-<span class="hlt">age</span> care profession. The <span class="hlt">model</span> work standards are…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999IJMPC..10..717A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999IJMPC..10..717A"><span id="translatedtitle">Virginia Opossums, Minimum Reproduction <span class="hlt">Age</span> and Predators in the Penna <span class="hlt">Aging</span> <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Altevolmer, A. K.</p> <p></p> <p><span class="hlt">Age</span>-specific predators are introduced into the Penna <span class="hlt">model</span> of biological <span class="hlt">aging</span>. It is shown that populations with a variable minimum reproduction <span class="hlt">age</span> find a stable state with an earlier onset of reproduction, if older <span class="hlt">ages</span> are eaten by the predators. This behavior agrees with the demographic data of the Virgina opossum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11798109','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11798109"><span id="translatedtitle">Source apportionment of gaseous atmospheric pollutants by means of an <span class="hlt">absolute</span> principal component scores (APCS) receptor <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bruno, P; Caselli, M; de Gennaro, G; Traini, A</p> <p>2001-12-01</p> <p>A multivariate statistical method has been applied to apportion the atmospheric pollutant concentrations measured by automatic gas analyzers placed on a mobile laboratory for air quality monitoring in Taranto (Italy). In particular, Principal Component Analysis (PCA) followed by <span class="hlt">Absolute</span> Principal Component Scores (APCS) technique was performed to identify the number of emission sources and their contribution to measured concentrations of CO, NOx, benzene toluene m+p-Xylene (BTX). This procedure singled out two different sources that explain about 85% of collected data variance. PMID:11798109</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AAS...22513816M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AAS...22513816M"><span id="translatedtitle">Testing Stellar Evolution <span class="hlt">Models</span>: <span class="hlt">Absolute</span> Dimensions of the Low-Mass Eclipsing Binary Star V651 Cassiopeiae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matthews, Allison; Torres, Guillermo</p> <p>2015-01-01</p> <p>We report accurate values of several key quantities for the low-mass, 0.9968096 day period, double-lined eclipsing binary V651 Cas. We determine accurate values for the masses, radii and temperatures of the primary and secondary as follows: M = 0.8553(81) solar masses, R = 0.957(17) solar radii, and effective temperature = 5733(100) K for the primary component, and M = 0.7564(48) solar masses, R = 0.771(15) solar radii, and effective temperature = 5113(105) for the secondary component, with formal uncertainties shown in parentheses. A comparison with the stellar evolution <span class="hlt">models</span> from the Dartmouth Stellar Evolution Program suggests an <span class="hlt">age</span> of 11(1) Gyr for a best-fit metallicity of [Fe/H] = -0.2. While the isochrone mentioned correctly reproduces the measured radii and temperatures of the stars within the current uncertainties, we note that the secondary radius appears marginally larger and the temperature marginally cooler than <span class="hlt">models</span> would predict. This is consistent with similar discrepancies found for other low-mass stars, generally accredited to surface activity. With further improvement in the measurement errors, and a spectroscopic measure of the metallicity, V651 Cas should be a valuable system for understanding the effects of magnetic activity on the global structure of low-mass stars and for providing guidance to improve stellar evolution <span class="hlt">models</span>.This work was supported in part by the NSF REU and DoD ASSURE programs under NSF grant no. 1262851 and by the Smithsonian Institution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.V23C1555B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.V23C1555B"><span id="translatedtitle">Preliminary Monazite U-Th-Total Pb <span class="hlt">Absolute</span> <span class="hlt">Age</span> Constraints on Crustal Thickening and Siluro-Devonian Dextral Transpression: Central Appalachian Piedmont, SE Pennsylvania</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bosbyshell, H.; Srogi, L.; Pyle, J. M.; Blackmer, G. C.</p> <p>2007-12-01</p> <p>High grade metamorphic rocks in the Central Appalachian piedmont of SE Pa. occur in at least three distinct lithotectonic belts that are bounded by steeply dipping, NE-striking transcurrent or transpressional shear zones. From NW to SE these belts consist of rocks of Laurentian-, uncertain-, and arc-affinity. The central belt is characterized by basement gneiss-cored nappes and associated shallowly to moderately SE dipping S2 foliation. This belt followed a clockwise metamorphic P-T path; maximum temperatures (T ~ 640 °C at P ~ 0.7 GPa) are associated with syn- to post-S2 garnet growth. An increase in pressure of ~ 0.1 GPa is inferred from post- kinematic high-Ca garnet rims. This paper reports preliminary EPMA results on monazite from two samples, WG- 216 and U-154, from the Glenarm Wissahickon, the metasedimentary cover sequence in the central belt. A few monazite grains from WG-216 exhibit small low-Th cores which give latest Cambrian <span class="hlt">ages</span> (492 +/- 10 Ma, n = 10; n = # of analyses, all precision is reported as 2 s.e.). All grains in WG-216 contain cores with irregular, patchy zoning that yield late Ordovician <span class="hlt">ages</span> (454 +/- 6 Ma, n = 31). High-Th, low-Y rims, which yield early Devonian <span class="hlt">ages</span> (410 +/- 11 Ma, n = 12), are present on monazite inclusions in the outer portions of garnet and staurolite, but are absent in monazite inclusions within microlithons characterized by S1 foliation. High-Th, low-Y rims grow along 001 cleavage in S2 foliation-forming micas, so S2 can be no younger than monazite rims. Similar EPMA monazite results were obtained from U-154, also from the Glenarm Wissahickon. At least one Ordovician core is present (455 +/- 4 Ma, n = 8); pre-S2 matrix monazite and one inclusion in staurolite yield late Silurian <span class="hlt">ages</span> (422 +/- 4 Ma, n = 29); and one inclusion within outermost garnet yields a Devonian <span class="hlt">age</span> (415 +/- 8 Ma, n = 8). These results constrain the timing of S2 formation and peak metamorphism in the central belt to the early Devonian. The SE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhRvE..69b1903B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhRvE..69b1903B"><span id="translatedtitle">Evolutionary <span class="hlt">model</span> with genetics, <span class="hlt">aging</span>, and knowledge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bustillos, Armando Ticona; de Oliveira, Paulo Murilo</p> <p>2004-02-01</p> <p>We represent a process of learning by using bit strings, where 1 bits represent the knowledge acquired by individuals. Two ways of learning are considered: individual learning by trial and error, and social learning by copying knowledge from other individuals or from parents in the case of species with parental care. The <span class="hlt">age</span>-structured bit string allows us to study how knowledge is accumulated during life and its influence over the genetic pool of a population after many generations. We use the Penna <span class="hlt">model</span> to represent the genetic inheritance of each individual. In order to study how the accumulated knowledge influences the survival process, we include it to help individuals to avoid the various death situations. Modifications in the Verhulst factor do not show any special feature due to its random nature. However, by adding years to life as a function of the accumulated knowledge, we observe an improvement of the survival rates while the genetic fitness of the population becomes worse. In this latter case, knowledge becomes more important in the last years of life where individuals are threatened by diseases. Effects of offspring overprotection and differences between individual and social learning can also be observed. Sexual selection as a function of knowledge shows some effects when fidelity is imposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17460185','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17460185"><span id="translatedtitle">Mitochondrial DNA-deficient <span class="hlt">models</span> and <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Olgun, Abdullah; Akman, Serif</p> <p>2007-04-01</p> <p>Human mitochondrial DNA (mtDNA) encodes 13 subunits of oxidative phosphorylation (OXPHOS) enzyme complexes I, III, IV, and V except complex II. MtDNA is more sensitive to oxidative damage than nuclear DNA. MtDNA defects are involved in many pathologies including <span class="hlt">aging</span>. Several mtDNA-deficient cell culture, yeast, and animal <span class="hlt">models</span> were generated to study the role of mtDNA in many physiological processes. Ethidium bromide (EB), an agent that is known to inhibit mtDNA replication with a negligible effect on nuclear DNA, is generally used to generate mtDNA-deficient <span class="hlt">models</span>. The antibiotics chloramphenicol and doxycycline, which were known to inhibit mitochondrial translation, were also used to generate the same phenotype. Cultured mtDNA-deficient cells need uridine and pyruvate to survive. At the organismal level, uridine can be supplemented, but pyruvate supplementation can cause a worser phenotype because of lactic acidosis. In C. elegans, EB, when used during larval development, increases life span, but decreases, when used after the beginning of adult stage. This should be kept in mind since mitochondria-related genes are generally detected in genome-wide screening studies for longevity. We believe that conditional knockout studies need to be carried out for these genes after reaching adulthood. MtDNA mutator mouse did not show an increase of free radical production. Therefore, the downstream phenomena to mtDNA defects are likely ineffective pyrimidine synthesis (dihydroorotate dehydrogenase, DHODH, needs a functional respiratory chain) and excess NADH (decreased NAD pool) in addition to free radicals. PMID:17460185</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25916590','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25916590"><span id="translatedtitle"><span class="hlt">Models</span> to explore genetics of human <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karasik, David; Newman, Anne</p> <p>2015-01-01</p> <p>Genetic studies have bestowed insight into the biological mechanisms underlying inter-individual differences in susceptibility to (or resistance to) organisms’ <span class="hlt">aging</span>. Recent advances in molecular and genetic epidemiology provide tools to explore the genetic sources of the variability in biological <span class="hlt">aging</span> in humans. To be successful, the genetic study of a complex condition such as <span class="hlt">aging</span> requires the clear definition of essential traits that can characterize the <span class="hlt">aging</span> process phenotypically. Phenotypes of human <span class="hlt">aging</span> have long relied on mortality rate or exceptional longevity. Genome-wide association studies (GWAS) have been shown to present an unbiased approach to the identification of new candidate genes for human diseases. The GWAS approach can also be used for positive health phenotypes such as longevity or a delay in <span class="hlt">age</span>-related chronic disease, as well as for other <span class="hlt">age</span> related changes such as loss of telomere length or lens transparency. Sequencing, either in targeted regions or across the whole genome can further identify rare variation that may contribute to the biological <span class="hlt">aging</span> mechanisms. To date, the results of the GWAS for longevity are rather disappointing, possibly in part due to the small number of individuals with GWAS data who have reached advanced old <span class="hlt">age</span>.Human <span class="hlt">aging</span> phenotypes are needed that can be assessed prior to death, and should be both heritable and validated as predictors of longevity. Potentially, phenotypes that focus on “successful” or “healthy” <span class="hlt">aging</span> will be more powerful as they can be measured in large numbers of people and also are clinically relevant.We postulate that construction of an integrated phenotype of <span class="hlt">aging</span> can be achieved capitalizing on multiple traits that may have weak correlations, but a shared underlying genetic architecture. This is based on a hypothesis that convergent results from multiple individual <span class="hlt">aging</span>-related traits will point out the pleiotropic signals responsible for the overall rate of <span class="hlt">aging</span> of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23586876','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23586876"><span id="translatedtitle"><span class="hlt">Absolute</span> biological needs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McLeod, Stephen</p> <p>2014-07-01</p> <p><span class="hlt">Absolute</span> needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended <span class="hlt">absolute</span> needs on the grounds that the verb 'need' has instrumental and <span class="hlt">absolute</span> senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are <span class="hlt">absolute</span> biological needs. The <span class="hlt">absolute</span> nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of <span class="hlt">absolute</span> need is not inherently normative in either of the first two senses. PMID:23586876</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPC.1382...49W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPC.1382...49W"><span id="translatedtitle"><span class="hlt">Absolute</span> neutrino mass measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wolf, Joachim</p> <p>2011-10-01</p> <p>The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2β) searches, single β-decay experiments provide a direct, <span class="hlt">model</span>-independent way to determine the <span class="hlt">absolute</span> neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy. Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium β-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope (137Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R&D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2β decay and single β-decay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21611867','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21611867"><span id="translatedtitle"><span class="hlt">Absolute</span> neutrino mass measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wolf, Joachim</p> <p>2011-10-06</p> <p>The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, <span class="hlt">model</span>-independent way to determine the <span class="hlt">absolute</span> neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1211631W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1211631W"><span id="translatedtitle">The 238U/235U isotope ratio of the Earth and the solar system: Constrains from a gravimetrically calibrated U double spike and implications for <span class="hlt">absolute</span> Pb-Pb <span class="hlt">ages</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weyer, Stefan; Noordmann, Janine; Brennecka, Greg; Richter, Stephan</p> <p>2010-05-01</p> <p>The ratio of 238U and 235U, the two primordial U isotopes, has been assumed to be constant on Earth and in the solar system. The commonly accepted value for the 238U/235U ratio, which has been used in Pb-Pb dating for the last ~ 30 years, was 137.88. Within the last few years, it has been shown that 1) there are considerable U isotope variations (~1.3‰) within terrestrial material produced by isotope fractionation during chemical reactions [1-3] and 2) there are even larger isotope variations (at least 3.5‰) in calcium-aluminum-rich inclusions (CAIs) in meoteorites that define the currently accepted <span class="hlt">age</span> of the solar system [4]. These findings are dramatic for geochronology, as a known 238U/235U is a requirement for Pb-Pb dating, the most precise dating technique for <span class="hlt">absolute</span> <span class="hlt">ages</span>. As 238U/235U variations can greatly affect the reported <span class="hlt">absolute</span> Pb-Pb <span class="hlt">age</span>, understanding and accurately measuring variation of the 238U/235U ratio in various materials is critical, With these new findings, the questions also arises of "How well do we know the average U isotope composition of the Earth and the solar system?" and "How accurate can <span class="hlt">absolute</span> Pb-Pb <span class="hlt">ages</span> be?" Our results using a gravimetrically calibrated 233U/236U double spike IRMM 3636 [5] indicate that the U standard NBL 950a, which was commonly used to define the excepted "natural" 238U/235U isotope ratio, has a slightly lower 238U/235U of 137.836 ± 0.024. This value is indistinguishable from the U isotope compositions for NBL 960 and NBL112A, which have been determined by several laboratories, also using the newly calibrated U double spike IRMM 3636 [6]. These findings provide new implications about the average U isotope composition of the Earth and the solar system. Basalts display a very tight range of U isotope variations (~0.25-0.32‰ relative to SRM 950a). Their U isotope composition is also very similar to that of chondrites [4], which however appear to show a slightly larger spread. Accepting terrestrial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=origin+AND+algebra&pg=3&id=EJ458199','ERIC'); return false;" href="http://eric.ed.gov/?q=origin+AND+algebra&pg=3&id=EJ458199"><span id="translatedtitle">Inequalities, <span class="hlt">Absolute</span> Value, and Logical Connectives.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Parish, Charles R.</p> <p>1992-01-01</p> <p>Presents an approach to the concept of <span class="hlt">absolute</span> value that alleviates students' problems with the traditional definition and the use of logical connectives in solving related problems. Uses a <span class="hlt">model</span> that maps numbers from a horizontal number line to a vertical ray originating from the origin. Provides examples solving <span class="hlt">absolute</span> value equations and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22734119W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22734119W"><span id="translatedtitle">Using A New <span class="hlt">Model</span> for Main Sequence Turnoff <span class="hlt">Absolute</span> Magnitudes to Measure Stellar Streams in the Milky Way Halo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weiss, Jake; Newberg, Heidi Jo; Arsenault, Matthew; Bechtel, Torrin; Desell, Travis; Newby, Matthew; Thompson, Jeffery M.</p> <p>2016-01-01</p> <p>Statistical photometric parallax is a method for using the distribution of <span class="hlt">absolute</span> magnitudes of stellar tracers to statistically recover the underlying density distribution of these tracers. In previous work, statistical photometric parallax was used to trace the Sagittarius Dwarf tidal stream, the so-called bifurcated piece of the Sagittaritus stream, and the Virgo Overdensity through the Milky Way. We use an improved knowledge of this distribution in a new algorithm that accounts for the changes in the stellar population of color-selected stars near the photometric limit of the Sloan Digital Sky Survey (SDSS). Although we select bluer main sequence turnoff stars (MSTO) as tracers, large color errors near the survey limit cause many stars to be scattered out of our selection box and many fainter, redder stars to be scattered into our selection box. We show that we are able to recover parameters for analogues of these streams in simulated data using a maximum likelihood optimization on MilkyWay@home. We also present the preliminary results of fitting the density distribution of major Milky Way tidal streams in SDSS data. This research is supported by generous gifts from the Marvin Clan, Babette Josephs, Manit Limlamai, and the MilkyWay@home volunteers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3320804','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3320804"><span id="translatedtitle">Successful <span class="hlt">Aging</span> as a Continuum of Functional Independence: Lessons from Physical Disability <span class="hlt">Models</span> of <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lowry, Kristin A.; Vallejo, Abbe N.; Studenski, Stephanie A.</p> <p>2011-01-01</p> <p>Successful <span class="hlt">aging</span> is a multidimensional construct that could be viewed as a continuum of achievement. Based on the disability <span class="hlt">model</span> proposed by the WHO International Classification of Functioning, Disability and Health, successful <span class="hlt">aging</span> includes not only the presence or absence of disease, but also aspects of mobility and social participation. Here we review definitions of successful <span class="hlt">aging</span> and discuss relevance of the disability <span class="hlt">model</span> in the evaluation of successful <span class="hlt">aging</span> and frailty. In particular, we summarize evidences that highlight the importance of measures of mobility (ability to walk and perform activities of daily living), and social participation in identifying and locating older adults across the range of the successful <span class="hlt">aging</span> continuum. Lastly, we discuss the role of inflammation in <span class="hlt">age</span>-related decline and in frailty. Future research directions are proposed, including identifying causal pathways among inflammatory markers, disability, and frailty. A better understanding of immunological functioning in late life may help unlock novel ways to promote successful <span class="hlt">aging</span>. PMID:22500268</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4496O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4496O"><span id="translatedtitle">Possibilities of <span class="hlt">modelling</span> of local and global hydrological changes from high-resolution Global Hydrological <span class="hlt">Model</span> in the <span class="hlt">absolute</span> gravity observations - the case of Józefosław Observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olszak, Tomasz; Barlik, Marcin; Pachuta, Andrzej; Próchniewicz, Dominik</p> <p>2014-05-01</p> <p>Geodynamical use of epoch gravimetric relative and <span class="hlt">absolute</span> observations requires the elimination of one from the most significant effect related to local and global changes of hydrological conditions. It is understood that hydrological effect is associated with changes in groundwater levels and soil moisture around the gravimetric station. In Poland, the quasi - permanent observations of gravity changes by <span class="hlt">absolute</span> method carried out since 2005 on gravity station located in the Astronomical - Geodetic Observatory in Józefosław. In the poster will be shortly described measurement strategy of <span class="hlt">absolute</span> observations and different approaches to the elimination of the local and global effects associated with changes in hydrology. This paper will discuss the results of the analysis of tidal observations relevant to the development of <span class="hlt">absolute</span> observations - seasonal changes in barometric correction factor and differences in the locally designated tidal corrections <span class="hlt">model</span>. Analysis of the possibility of elimination the impact of global hydrological influence is based on the <span class="hlt">model</span> GLDAS a spatial resolution of 0.25 degree independently on a local scale and global. Józefosław Observatory is equipped with additional sensors linked to the monitoring of local hydrological conditions. It gives a possibility to verify the quality of <span class="hlt">modeling</span> of hydrological changes using global <span class="hlt">models</span> in local and global scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1231575-absolute-path-command','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1231575-absolute-path-command"><span id="translatedtitle">The <span class="hlt">absolute</span> path command</span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p>2012-05-11</p> <p>The ap command traveres all symlinks in a given file, directory, or executable name to identify the final <span class="hlt">absolute</span> path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the <span class="hlt">absolute</span> path to a relative directory from the current working directory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1231575','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1231575"><span id="translatedtitle">The <span class="hlt">absolute</span> path command</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moody, A.</p> <p>2012-05-11</p> <p>The ap command traveres all symlinks in a given file, directory, or executable name to identify the final <span class="hlt">absolute</span> path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the <span class="hlt">absolute</span> path to a relative directory from the current working directory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4294461','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4294461"><span id="translatedtitle">Efficacy of Female Rat <span class="hlt">Models</span> in Translational Cardiovascular <span class="hlt">Aging</span> Research</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rice, K. M.; Fannin, J. C.; Gillette, C.; Blough, E. R.</p> <p>2014-01-01</p> <p>Cardiovascular disease is the leading cause of death in women in the United States. <span class="hlt">Aging</span> is a primary risk factor for the development of cardiovascular disease as well as cardiovascular-related morbidity and mortality. <span class="hlt">Aging</span> is a universal process that all humans undergo; however, research in <span class="hlt">aging</span> is limited by cost and time constraints. Therefore, most research in <span class="hlt">aging</span> has been done in primates and rodents; however it is unknown how well the effects of <span class="hlt">aging</span> in rat <span class="hlt">models</span> translate into humans. To compound the complication of <span class="hlt">aging</span> gender has also been indicated as a risk factor for various cardiovascular diseases. This review addresses the systemic pathophysiology of the cardiovascular system associated with <span class="hlt">aging</span> and gender for <span class="hlt">aging</span> research with regard to the applicability of rat derived data for translational application to human <span class="hlt">aging</span>. PMID:25610649</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27547370','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27547370"><span id="translatedtitle">A comparison of <span class="hlt">absolute</span> performance of different correlative and mechanistic species distribution <span class="hlt">models</span> in an independent area.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shabani, Farzin; Kumar, Lalit; Ahmadi, Mohsen</p> <p>2016-08-01</p> <p>To investigate the comparative abilities of six different bioclimatic <span class="hlt">models</span> in an independent area, utilizing the distribution of eight different species available at a global scale and in Australia. Global scale and Australia. We tested a variety of bioclimatic <span class="hlt">models</span> for eight different plant species employing five discriminatory correlative species distribution <span class="hlt">models</span> (SDMs) including Generalized Linear <span class="hlt">Model</span> (GLM), MaxEnt, Random Forest (RF), Boosted Regression Tree (BRT), Bioclim, together with CLIMEX (CL) as a mechanistic niche <span class="hlt">model</span>. These <span class="hlt">models</span> were fitted using a training dataset of available global data, but with the exclusion of Australian locations. The capabilities of these techniques in projecting suitable climate, based on independent records for these species in Australia, were compared. Thus, Australia is not used to calibrate the <span class="hlt">models</span> and therefore it is as an independent area regarding geographic locations. To assess and compare performance, we utilized the area under the receiver operating characteristic (ROC) curves (AUC), true skill statistic (TSS), and fractional predicted areas for all SDMs. In addition, we assessed satisfactory agreements between the outputs of the six different bioclimatic <span class="hlt">models</span>, for all eight species in Australia. The <span class="hlt">modeling</span> method impacted on potential distribution predictions under current climate. However, the utilization of sensitivity and the fractional predicted areas showed that GLM, MaxEnt, Bioclim, and CL had the highest sensitivity for Australian climate conditions. Bioclim calculated the highest fractional predicted area of an independent area, while RF and BRT were poor. For many applications, it is difficult to decide which bioclimatic <span class="hlt">model</span> to use. This research shows that variable results are obtained using different SDMs in an independent area. This research also shows that the SDMs produce different results for different species; for example, Bioclim may not be good for one species but works better</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JVGR..310..172S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JVGR..310..172S"><span id="translatedtitle">The oscillation <span class="hlt">model</span> of hydrothermal dynamics beneath Aso volcano, southwest Japan after small eruption on May 2011: A new understanding <span class="hlt">model</span> using repeated <span class="hlt">absolute</span> and relative gravity measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sofyan, Yayan; Nishijima, Jun; Fujimitsu, Yasuhiro; Yoshikawa, Shin; Kagiyama, Tsuneomi; Ohkura, Takahiro</p> <p>2016-01-01</p> <p>At the end of 2010, the seismic activity in Aso volcano intensely increased and water level in the Nakadake crater decreased until early in 2011, then was followed by a small eruption in May 2011. After the eruption and heavy rain, the volcanic activity subsided to calm period, crater bottom was refilled with water, and water level increased in the Nakadake crater. The next tremor reappeared in 2014 and tracked to eruption in November 2014. This eruptive pattern and water level variation in the crater repeatedly appeared on the surface, and it should be related to the hydrothermal dynamics beneath Aso volcano. We initiated the gravity measurements in relation to hydrothermal dynamics in the subsurface of Aso volcano using Scintrex CG-5 (549) and LaCoste Romberg type G-1016 relative gravimeter at 28 benchmarks in April 2011, one month before the eruption. The repeated gravity measurements continue to monitor Aso volcano with a series of the measurement after the eruption in every three months to a half year. We analyze the gravity variation from 2011 to 2014 between the time of the phreatic and strombolian eruption. The measurements covered the area more than 60 km2 in the west side of Aso caldera. A new gravity network was also installed in May 2010 at seven benchmarks using A10-017 <span class="hlt">absolute</span> gravimeter, which re-occupied in October 2010, June 2011 and two benchmarks in June 2014. As a result, the gravity changes distinguish hydrothermal dynamic in the subsurface, which has a direct correlation to water level fluctuation in the crater, after the first eruption and before the second discharge. The monitoring data notice large gravity changes between the surveys at benchmarks around Nakadake crater and Kusasenri area. The simple 3D inversion <span class="hlt">models</span> of the 4-D gravity data deduce the density contrast distribution beneath Aso volcano. The inversion and mass change result generate the oscillation typical as a new understanding <span class="hlt">model</span>. The variation of the mass shows a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950064077&hterms=IA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DIA','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950064077&hterms=IA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DIA"><span id="translatedtitle">Delayed detonation <span class="hlt">models</span> for normal and subluminous type Ia sueprnovae: <span class="hlt">Absolute</span> brightness, light curves, and molecule formation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoflich, P.; Khokhlov, A. M.; Wheeler, J. C.</p> <p>1995-01-01</p> <p>We compute optical and infrared light curves of the pulsating class of delayed detonation <span class="hlt">models</span> for Type Ia supernovae (SN Ia's) using an elaborate treatment of the Local Thermodynamic Equilbrium (LTE) radiation transport, equation of state and ionization balance, expansion opacity including the cooling by CO, Co(+), and SiO, and a Monte Carlo gamma-ray deposition scheme. The <span class="hlt">models</span> have an amount of Ni-56 in the range from approximately or equal to 0.1 solar mass up to 0.7 solar mass depending on the density at which the transition from a deflagration to a detonation occurs. <span class="hlt">Models</span> with a large nickel production give light curves comparable to those of typical Type Ia supernovae. Subluminous supernovae can be explained by <span class="hlt">models</span> with a low nickel production. Multiband light curves are presented in comparison with the normally bright event SN 1992bc and the subluminous events Sn 1991bg and SN 1992bo to establish the principle that the delayed detonation paradigm in Chandrasekhar mass <span class="hlt">models</span> may give a common explosion mechanism accounting for both normal and subluminous SN Ia's. Secondary IR-maxima are formed in the <span class="hlt">models</span> of normal SN Ia's as a photospheric effect if the photospheric radius continues to increase well after maximum light. Secondary maxima appear later and stronger in <span class="hlt">models</span> with moderate expansion velocities and with radioactive material closer to the surface. <span class="hlt">Model</span> light curves for subluminous SN Ia's tend to show only one 'late' IR-maximum. In some delayed detonation <span class="hlt">models</span> shell-like envelopes form, which consist of unburned carbon and oxygen. The formation of molecules in these envelopes is addressed. If the <span class="hlt">model</span> retains a C/O-envelope and is subluminous, strong vibration bands of CO may appear, typically several weeks past maximum light. CO should be very weak or absent in normal Sn Ia's.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1183624','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1183624"><span id="translatedtitle"><span class="hlt">Age</span> and gender specific biokinetic <span class="hlt">model</span> for strontium in humans</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.</p> <p>2015-03-01</p> <p>A biokinetic <span class="hlt">model</span> for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic <span class="hlt">model</span> for strontium has limitation for use in a population study, because it is not gender specific and does not cover all <span class="hlt">age</span> ranges. The extensive Techa River data set on 90Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all <span class="hlt">ages</span> at intake. These, as well as published data, were used for evaluation of <span class="hlt">age</span>- and gender-specific parameters for a new compartment biokinetic <span class="hlt">model</span> for strontium (Sr-<span class="hlt">AGe</span> <span class="hlt">model</span>). The Sr-<span class="hlt">AGe</span> <span class="hlt">model</span> has similar structure as the ICRP <span class="hlt">model</span> for the alkaline earth elements. The following parameters were mainly reevaluated: gastro-intestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-<span class="hlt">AGe</span> <span class="hlt">model</span> satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different <span class="hlt">ages</span> (0–80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-<span class="hlt">AGe</span> <span class="hlt">model</span> can be used for dose assessment in epidemiological studies of general population exposed to ingested strontium radioisotopes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25574605','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25574605"><span id="translatedtitle"><span class="hlt">Age</span> and gender specific biokinetic <span class="hlt">model</span> for strontium in humans.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shagina, N B; Tolstykh, E I; Degteva, M O; Anspaugh, L R; Napier, B A</p> <p>2015-03-01</p> <p>A biokinetic <span class="hlt">model</span> for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic <span class="hlt">model</span> for strontium has limitations for use in a population study, because it is not gender specific and does not cover all <span class="hlt">age</span> ranges. The extensive Techa River data set on (90)Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all <span class="hlt">ages</span> at intake. These, as well as published data, were used for evaluation of <span class="hlt">age</span>- and gender-specific parameters for a new compartment biokinetic <span class="hlt">model</span> for strontium (Sr-<span class="hlt">AGe</span> <span class="hlt">model</span>). The Sr-<span class="hlt">AGe</span> <span class="hlt">model</span> has a similar structure to the ICRP <span class="hlt">model</span> for the alkaline earth elements. The following parameters were mainly re-evaluated: gastrointestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-<span class="hlt">AGe</span> <span class="hlt">model</span> satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different <span class="hlt">ages</span> (0-80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-<span class="hlt">AGe</span> <span class="hlt">model</span> can be used for dose assessment in epidemiological studies of general populations exposed to ingested strontium radioisotopes. PMID:25574605</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1009256','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1009256"><span id="translatedtitle">Role of <span class="hlt">Modeling</span> When Designing for <span class="hlt">Absolute</span> Energy Use Intensity Requirements in a Design-Build Framework: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hirsch, A.; Pless, S.; Guglielmetti, R.; Torcellini, P. A.; Okada, D.; Antia, P.</p> <p>2011-03-01</p> <p>The Research Support Facility was designed to use half the energy of an equivalent minimally code-compliant building, and to produce as much renewable energy as it consumes on an annual basis. These energy goals and their substantiation through simulation were explicitly included in the project's fixed firm price design-build contract. The energy <span class="hlt">model</span> had to be continuously updated during the design process and to match the final building as-built to the greatest degree possible. Computer <span class="hlt">modeling</span> played a key role throughout the design process and in verifying that the contractual energy goals would be met within the specified budget. The main tool was a whole building energy simulation program. Other <span class="hlt">models</span> were used to provide more detail or to complement the whole building simulation tool. Results from these specialized <span class="hlt">models</span> were fed back into the main whole building simulation tool to provide the most accurate possible inputs for annual simulations. This paper will detail the <span class="hlt">models</span> used in the design process and how they informed important program and design decisions on the path from preliminary design to the completed building.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARR43012F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARR43012F"><span id="translatedtitle">A network <span class="hlt">model</span> of human <span class="hlt">aging</span>: Limits, errors, and information</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farrell, Spencer; Mitnitski, Arnold; Rockwood, Kenneth; Rutenberg, Andrew</p> <p></p> <p>The Frailty Index (FI) quantifies human <span class="hlt">aging</span> using the fraction of accumulated <span class="hlt">age</span>-related deficits. The FI correlates strongly with mortality and accumulates non-linearly and stochastically with <span class="hlt">age</span>. Clinical data shows a nearly universal limit of FI <= 0 . 7 . We computationally <span class="hlt">model</span> an <span class="hlt">aging</span> population using a network <span class="hlt">model</span> of interacting deficits. Deficits damage and repair at rates that depend upon the average damage of connected nodes. The <span class="hlt">model</span> is parametrized to fit clinical data. We find that attribution errors, especially false negative, allow the <span class="hlt">model</span> to recover the frailty limit. Mutual information allows us to assess how well the FI can predict mortality. Mutual information provides a non-parametric measure of how the FI predicts mortality. We find that attribution errors have a small effect on the mutual information when many deficits are included in the <span class="hlt">model</span>. The mutual information of our <span class="hlt">model</span> and of the clinical data are comparable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015SPIE.9443E..0AA&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015SPIE.9443E..0AA&link_type=ABSTRACT"><span id="translatedtitle">An integrated <span class="hlt">modeling</span> approach to <span class="hlt">age</span> invariant face recognition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alvi, Fahad Bashir; Pears, Russel</p> <p>2015-03-01</p> <p>This Research study proposes a novel method for face recognition based on Anthropometric features that make use of an integrated approach comprising of a global and personalized <span class="hlt">models</span>. The system is aimed to at situations where lighting, illumination, and pose variations cause problems in face recognition. A Personalized <span class="hlt">model</span> covers the individual <span class="hlt">aging</span> patterns while a Global <span class="hlt">model</span> captures general <span class="hlt">aging</span> patterns in the database. We introduced a de-<span class="hlt">aging</span> factor that de-<span class="hlt">ages</span> each individual in the database test and training sets. We used the k nearest neighbor approach for building a personalized <span class="hlt">model</span> and global <span class="hlt">model</span>. Regression analysis was applied to build the <span class="hlt">models</span>. During the test phase, we resort to voting on different features. We used FG-Net database for checking the results of our technique and achieved 65 percent Rank 1 identification rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AIPC.1637.1416H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AIPC.1637.1416H"><span id="translatedtitle">Eddy current <span class="hlt">modeling</span> by finite element method for evaluation of mechanical properties of the structure cracked in <span class="hlt">absolute</span> probe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harzallah, Salaheddine; Chabaat, Mohamed; Belgacem, Fethi Bin Muhammad</p> <p>2014-12-01</p> <p>In this paper, a nondestructive evaluation by sensor Eddy current is used as a tool to control cracks and micro-cracks in materials. A simulation by a numerical approach based on the finite element method is employed to detect cracks in materials and eventually to study their propagation using a crucial parameter such as a Stress Intensity Factor (SIF). This method has emerged as one of the most efficient techniques for prospecting cracks in materials, evaluating SIFs and analyzing crack's growth in the context of linear elastic fracture mechanics (LEFM). This technique uses extrapolation of displacements from results compared with those obtained by the integral interaction. On the other hand, crack's growth is analyzed as a <span class="hlt">model</span> by combining the maximum circumferential stress criteria with the critical plane for predicting the direction of crack growth. Moreover, a constant crack growth increment is determined using the modified Paris's <span class="hlt">model</span>. Furthermore, stress intensity factors needed for these <span class="hlt">models</span> are calculated using the domain form of the J-integral interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19658536','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19658536"><span id="translatedtitle">Numerical solution of the Penna <span class="hlt">model</span> of biological <span class="hlt">aging</span> with <span class="hlt">age</span>-modified mutation rate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Magdoń-Maksymowicz, M S; Maksymowicz, A Z</p> <p>2009-06-01</p> <p>In this paper we present results of numerical calculation of the Penna bit-string <span class="hlt">model</span> of biological <span class="hlt">aging</span>, modified for the case of a -dependent mutation rate m(a), where a is the parent's <span class="hlt">age</span>. The mutation rate m(a) is the probability per bit of an extra bad mutation introduced in offspring inherited genome. We assume that m(a) increases with <span class="hlt">age</span> a. As compared with the reference case of the standard Penna <span class="hlt">model</span> based on a constant mutation rate m , the dynamics of the population growth shows distinct changes in <span class="hlt">age</span> distribution of the population. Here we concentrate on mortality q(a), a fraction of items eliminated from the population when we go from <span class="hlt">age</span> (a) to (a+1) in simulated transition from time (t) to next time (t+1). The experimentally observed q(a) dependence essentially follows the Gompertz exponential law for a above the minimum reproduction <span class="hlt">age</span>. Deviation from the Gompertz law is however observed for the very old items, close to the maximal <span class="hlt">age</span>. This effect may also result from an increase in mutation rate m with <span class="hlt">age</span> a discussed in this paper. The numerical calculations are based on analytical solution of the Penna <span class="hlt">model</span>, presented in a series of papers by Coe et al. [J. B. Coe, Y. Mao, and M. E. Cates, Phys. Rev. Lett. 89, 288103 (2002)]. Results of the numerical calculations are supported by the data obtained from computer simulation based on the solution by Coe et al. PMID:19658536</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED060180.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED060180.pdf"><span id="translatedtitle">An <span class="hlt">Age</span>-Graded <span class="hlt">Model</span> for Career Development Education.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tuckman, Bruce W.</p> <p></p> <p>This paper presents a career developmental <span class="hlt">model</span> covering the <span class="hlt">ages</span> of 5 to 18. Career development education includes experiences which facilitate self-awareness, career-awareness and career decision-making. Before choosing a <span class="hlt">model</span> for career development, it is necessary to decide on a <span class="hlt">model</span> for child development. The <span class="hlt">model</span> developed here borrows…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JPS...325..273B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JPS...325..273B&link_type=ABSTRACT"><span id="translatedtitle">Lithium battery <span class="hlt">aging</span> <span class="hlt">model</span> based on Dakin's degradation approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baghdadi, Issam; Briat, Olivier; Delétage, Jean-Yves; Gyan, Philippe; Vinassa, Jean-Michel</p> <p>2016-09-01</p> <p>This paper proposes and validates a calendar and power cycling <span class="hlt">aging</span> <span class="hlt">model</span> for two different lithium battery technologies. The <span class="hlt">model</span> development is based on previous SIMCAL and SIMSTOCK project data. In these previous projects, the effect of the battery state of charge, temperature and current magnitude on <span class="hlt">aging</span> was studied on a large panel of different battery chemistries. In this work, data are analyzed using Dakin's degradation approach. In fact, the logarithms of battery capacity fade and the increase in resistance evolves linearly over <span class="hlt">aging</span>. The slopes identified from straight lines correspond to battery <span class="hlt">aging</span> rates. Thus, a battery <span class="hlt">aging</span> rate expression function of <span class="hlt">aging</span> factors was deduced and found to be governed by Eyring's law. The proposed <span class="hlt">model</span> simulates the capacity fade and resistance increase as functions of the influencing <span class="hlt">aging</span> factors. Its expansion using Taylor series was consistent with semi-empirical <span class="hlt">models</span> based on the square root of time, which are widely studied in the literature. Finally, the influence of the current magnitude and temperature on <span class="hlt">aging</span> was simulated. Interestingly, the <span class="hlt">aging</span> rate highly increases with decreasing and increasing temperature for the ranges of -5 °C-25 °C and 25 °C-60 °C, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6986947','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6986947"><span id="translatedtitle">A comprehensive approach to <span class="hlt">age</span>-dependent dosimetric <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Leggett, R.W.; Cristy, M.; Eckerman, K.F.</p> <p>1986-01-01</p> <p>In the absence of <span class="hlt">age</span>-specific biokinetic <span class="hlt">models</span>, current retention <span class="hlt">models</span> of the International Commission on Radiological Protection (ICRP) frequently are used as a point of departure for evaluation of exposures to the general population. These <span class="hlt">models</span> were designed and intended for estimation of long-term integrated doses to the adult worker. Their format and empirical basis preclude incorporation of much valuable physiological information and physiologically reasonable assumptions that could be used in characterizing the <span class="hlt">age</span>-specific behavior of radioelements in humans. In this paper we discuss a comprehensive approach to <span class="hlt">age</span>-dependent dosimetric <span class="hlt">modeling</span> in which consideration is given not only to changes with <span class="hlt">age</span> in masses and relative geometries of body organs and tissues but also to best available physiological and radiobiological information relating to the <span class="hlt">age</span>-specific biobehavior of radionuclides. This approach is useful in obtaining more accurate estimates of long-term dose commitments as a function of <span class="hlt">age</span> at intake, but it may be particularly valuable in establishing more accurate estimates of dose rate as a function of <span class="hlt">age</span>. <span class="hlt">Age</span>-specific dose rates are needed for a proper analysis of the potential effects on estimates or risk of elevated dose rates per unit intake in certain stages of life, elevated response per unit dose received during some stages of life, and <span class="hlt">age</span>-specific non-radiogenic competing risks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NewA...34..234O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NewA...34..234O"><span id="translatedtitle">Galactic <span class="hlt">model</span> parameters of cataclysmic variables: Results from a new <span class="hlt">absolute</span> magnitude calibration with 2MASS and WISE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Özdönmez, A.; Ak, T.; Bilir, S.</p> <p>2015-01-01</p> <p>In order to determine the spatial distribution, Galactic <span class="hlt">model</span> parameters and luminosity function of cataclysmic variables (CVs), a J-band magnitude limited sample of 263 CVs has been established using a newly constructed period-luminosity-colours (PLCs) relation which includes J,Ks and W1-band magnitudes in 2MASS and WISE photometries, and the orbital periods of the systems. This CV sample is assumed to be homogeneous regarding to distances as the new PLCs relation is calibrated with new or re-measured trigonometric parallaxes. Our analysis shows that the scaleheight of CVs is increasing towards shorter periods, although selection effects for the periods shorter than 2.25 h dramatically decrease the scaleheight: the scaleheight of the systems increases from 192 pc to 326 pc as the orbital period decreases from 12 to 2.25 h. The z-distribution of all CVs in the sample is well fitted by an exponential function with a scaleheight of 213-10+11 pc. However, we suggest that the scaleheight of CVs in the Solar vicinity should be ∼300 pc and that the scaleheights derived using the sech2 function should be also considered in the population synthesis <span class="hlt">models</span>. The space density of CVs in the Solar vicinity is found 5.58(1.35)×10-6 pc-3 which is in the range of previously derived space densities and not in agreement with the predictions of the population <span class="hlt">models</span>. The analysis based on the comparisons of the luminosity function of white dwarfs with the luminosity function of CVs in this study show that the best fits are obtained by dividing the luminosity functions of white dwarfs by a factor of 350-450.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3444043','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3444043"><span id="translatedtitle">Nutraceutical Interventions for Promoting Healthy <span class="hlt">Aging</span> in Invertebrate <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dong, Yuqing; Guha, Sujay; Sun, Xiaoping; Cao, Min; Wang, Xiaoxia; Zou, Sige</p> <p>2012-01-01</p> <p><span class="hlt">Aging</span> is a complex and inevitable biological process that is associated with numerous chronically debilitating health effects. Development of effective interventions for promoting healthy <span class="hlt">aging</span> is an active but challenging area of research. Mechanistic studies in various <span class="hlt">model</span> organisms, noticeably two invertebrates, Caenorhabditis elegans and Drosophila melanogaster, have identified many genes and pathways as well as dietary interventions that modulate lifespan and healthspan. These studies have shed light on some of the mechanisms involved in <span class="hlt">aging</span> processes and provide valuable guidance for developing efficacious <span class="hlt">aging</span> interventions. Nutraceuticals made from various plants contain a significant amount of phytochemicals with diverse biological activities. Phytochemicals can modulate many signaling pathways that exert numerous health benefits, such as reducing cancer incidence and inflammation, and promoting healthy <span class="hlt">aging</span>. In this paper, we outline the current progress in <span class="hlt">aging</span> intervention studies using nutraceuticals from an evolutionary perspective in invertebrate <span class="hlt">models</span>. PMID:22991584</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016SPIE.9788E..0IH&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016SPIE.9788E..0IH&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Modeling</span> the brain morphology distribution in the general <span class="hlt">aging</span> population</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huizinga, W.; Poot, D. H. J.; Roshchupkin, G.; Bron, E. E.; Ikram, M. A.; Vernooij, M. W.; Rueckert, D.; Niessen, W. J.; Klein, S.</p> <p>2016-03-01</p> <p>Both normal <span class="hlt">aging</span> and neurodegenerative diseases such as Alzheimer's disease cause morphological changes of the brain. To better distinguish between normal and abnormal cases, it is necessary to <span class="hlt">model</span> changes in brain morphology owing to normal <span class="hlt">aging</span>. To this end, we developed a method for analyzing and visualizing these changes for the entire brain morphology distribution in the general <span class="hlt">aging</span> population. The method is applied to 1000 subjects from a large population imaging study in the elderly, from which 900 were used to train the <span class="hlt">model</span> and 100 were used for testing. The results of the 100 test subjects show that the <span class="hlt">model</span> generalizes to subjects outside the <span class="hlt">model</span> population. Smooth percentile curves showing the brain morphology changes as a function of <span class="hlt">age</span> and spatiotemporal atlases derived from the <span class="hlt">model</span> population are publicly available via an interactive web application at agingbrain.bigr.nl.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7260358','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7260358"><span id="translatedtitle">Econometric <span class="hlt">model</span> for <span class="hlt">age</span>- and population-dependent radiation exposures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sandquist, G.M.; Slaughter, D.M. ); Rogers, V.C.</p> <p>1991-01-01</p> <p>The economic impact associated with ionizing radiation exposures in a given human population depends on numerous factors including the individual's mean economic status as a function <span class="hlt">age</span>, the <span class="hlt">age</span> distribution of the population, the future life expectancy at each <span class="hlt">age</span>, and the latency period for the occurrence of radiation-induced health effects. A simple mathematical <span class="hlt">model</span> has been developed that provides an analytical methodology for estimating the societal econometrics associated with radiation effects are to be assessed and compared for economic evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMPP51A2273W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMPP51A2273W"><span id="translatedtitle">Probabilistically Constraining <span class="hlt">Age-Depth-Models</span> of Glaciogenic Sediments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Werner, J.; van der Bilt, W.; Tingley, M.</p> <p>2015-12-01</p> <p>Reconstructions of the late-Holocene climate rely heavily upon proxies that are assumed to be accurately dated by layer counting. All of these proxies, such as measurements of tree rings, ice cores, and varved lake sediments do carry some inherent dating uncertainty that is not always fully accounted for. Considerable advances could be achieved if time uncertainties were recognized and correctly <span class="hlt">modeled</span>, also for proxies commonly treated as free of <span class="hlt">age</span> <span class="hlt">model</span> errors. Current approaches for accounting for time uncertainty are generally limited to repeating the reconstruction using each one of an ensemble of <span class="hlt">age</span> <span class="hlt">models</span>, thereby inflating the final estimated uncertainty - in effect, each possible <span class="hlt">age</span> <span class="hlt">model</span> is given equal weighting. Uncertainties can be reduced by exploiting the inferred space-time covariance structure of the climate to re-weight the possible <span class="hlt">age</span> <span class="hlt">models</span>. Werner and Tingley (2015) demonstrated how Bayesian hierarchical climate reconstruction <span class="hlt">models</span> can be augmented to account for time-uncertain proxies. In their method, probabilities associated with the <span class="hlt">age</span> <span class="hlt">models</span> are formally updated within the Bayesian framework, thereby reducing uncertainties. Numerical experiments (Werner and Tingley 2015) show that updating the <span class="hlt">age</span> <span class="hlt">model</span> probabilities decreases uncertainty in the resulting reconstructions, as compared with the current de facto standard of sampling over all <span class="hlt">age</span> <span class="hlt">models</span>, provided there is sufficient information from other data sources in the spatial region of the time-uncertain proxy. We show how this novel method can be applied to high resolution, sub-annually sampled lacustrine sediment records to constrain their respective <span class="hlt">age</span> depth <span class="hlt">models</span>. The results help to quantify the signal content and extract the regionally representative signal. The single time series can then be used as the basis for a reconstruction of glacial activity. van der Bilt et al. in prep. Werner, J.P. and Tingley, M.P. Clim. Past (2015)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000IJMPC..11.1283M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000IJMPC..11.1283M"><span id="translatedtitle">Selection Experiments in the Penna <span class="hlt">Model</span> for Biological <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Medeiros, G.; Idiart, M. A.; de Almeida, R. M. C.</p> <p></p> <p>We consider the Penna <span class="hlt">model</span> for biological <span class="hlt">aging</span> to investigate correlations between early fertility and late life survival rates in populations at equilibrium. We consider inherited initial reproduction <span class="hlt">ages</span> together with a reproduction cost translated in a probability that mother and offspring die at birth, depending on the mother <span class="hlt">age</span>. For convenient sets of parameters, the equilibrated populations present genetic variability in what regards both genetically programmed death <span class="hlt">age</span> and initial reproduction <span class="hlt">age</span>. In the asexual Penna <span class="hlt">model</span>, a negative correlation between early life fertility and late life survival rates naturally emerges in the stationary solutions. In the sexual Penna <span class="hlt">model</span>, selection experiments are performed where individuals are sorted by initial reproduction <span class="hlt">age</span> from the equilibrated populations and the separated populations are evolved independently. After a transient, a negative correlation between early fertility and late <span class="hlt">age</span> survival rates also emerges in the sense that populations that start reproducing earlier present smaller average genetically programmed death <span class="hlt">age</span>. These effects appear due to the <span class="hlt">age</span> structure of populations in the steady state solution of the evolution equations. We claim that the same demographic effects may be playing an important role in selection experiments in the laboratory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMD.....8.2079K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMD.....8.2079K"><span id="translatedtitle">14C-<span class="hlt">age</span> tracers in global ocean circulation <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koeve, W.; Wagner, H.; Kähler, P.; Oschlies, A.</p> <p>2015-07-01</p> <p>The natural abundance of 14C in total CO2 dissolved in seawater (DIC) is a property applied to evaluate the water <span class="hlt">age</span> structure and circulation in the ocean and in ocean <span class="hlt">models</span>. In this study we use three different representations of the global ocean circulation augmented with a suite of idealised tracers to study the potential and limitations of using natural 14C to determine water <span class="hlt">age</span>, which is the time elapsed since a body of water has been in contact with the atmosphere. We find that, globally, bulk 14C-<span class="hlt">age</span> is dominated by two equally important components, one associated with <span class="hlt">ageing</span>, i.e. the time component of circulation, and one associated with a "preformed 14C-<span class="hlt">age</span>". The latter quantity exists because of the slow and incomplete atmosphere-ocean equilibration of 14C particularly in high latitudes where many water masses form. In the ocean's interior, preformed 14C-<span class="hlt">age</span> behaves like a passive tracer. The relative contribution of the preformed component to bulk 14C-<span class="hlt">age</span> varies regionally within a given <span class="hlt">model</span>, but also between <span class="hlt">models</span>. Regional variability in the Atlantic Ocean is associated with the mixing of waters with very different end members of preformed 14C-<span class="hlt">age</span>. Here, variations in the preformed component over space and time mask the circulation component to an extent that its patterns are not detectable from bulk 14C-<span class="hlt">age</span>. Between <span class="hlt">models</span>, the variability of preformed 14C-<span class="hlt">age</span> can also be considerable (factor of 2), related to the combination of physical <span class="hlt">model</span> parameters, which influence circulation dynamics or gas exchange. The preformed component was found to be very sensitive to gas exchange and moderately sensitive to ice cover. In our <span class="hlt">model</span> evaluation, the choice of the gas-exchange constant from within the currently accepted range of uncertainty had such a strong influence on preformed and bulk 14C-<span class="hlt">age</span> that if <span class="hlt">model</span> evaluation would be based on bulk 14C-<span class="hlt">age</span>, it could easily impair the evaluation and tuning of a <span class="hlt">model</span>'s circulation on global and regional</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1223389','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1223389"><span id="translatedtitle">Multiscale Concrete <span class="hlt">Modeling</span> of <span class="hlt">Aging</span> Degradation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hammi, Yousseff; Gullett, Philipp; Horstemeyer, Mark F.</p> <p>2015-07-31</p> <p>In this work a numerical finite element framework is implemented to enable the integration of coupled multiscale and multiphysics transport processes. A User Element subroutine (UEL) in Abaqus is used to simultaneously solve stress equilibrium, heat conduction, and multiple diffusion equations for 2D and 3D linear and quadratic elements. Transport processes in concrete structures and their degradation mechanisms are presented along with the discretization of the governing equations. The multiphysics <span class="hlt">modeling</span> framework is theoretically extended to the linear elastic fracture mechanics (LEFM) by introducing the eXtended Finite Element Method (XFEM) and based on the XFEM user element implementation of Giner et al. [2009]. A damage <span class="hlt">model</span> that takes into account the damage contribution from the different degradation mechanisms is theoretically developed. The total contribution of damage is forwarded to a Multi-Stage Fatigue (MSF) <span class="hlt">model</span> to enable the assessment of the fatigue life and the deterioration of reinforced concrete structures in a nuclear power plant. Finally, two examples are presented to illustrate the developed multiphysics user element implementation and the XFEM implementation of Giner et al. [2009].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22034529','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22034529"><span id="translatedtitle"><span class="hlt">MODELING</span> MULTI-WAVELENGTH STELLAR ASTROMETRY. III. DETERMINATION OF THE <span class="hlt">ABSOLUTE</span> MASSES OF EXOPLANETS AND THEIR HOST STARS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coughlin, J. L.; Lopez-Morales, Mercedes</p> <p>2012-05-10</p> <p>Astrometric measurements of stellar systems are becoming significantly more precise and common, with many ground- and space-based instruments and missions approaching 1 {mu}as precision. We examine the multi-wavelength astrometric orbits of exoplanetary systems via both analytical formulae and numerical <span class="hlt">modeling</span>. Exoplanets have a combination of reflected and thermally emitted light that causes the photocenter of the system to shift increasingly farther away from the host star with increasing wavelength. We find that, if observed at long enough wavelengths, the planet can dominate the astrometric motion of the system, and thus it is possible to directly measure the orbits of both the planet and star, and thus directly determine the physical masses of the star and planet, using multi-wavelength astrometry. In general, this technique works best for, though is certainly not limited to, systems that have large, high-mass stars and large, low-mass planets, which is a unique parameter space not covered by other exoplanet characterization techniques. Exoplanets that happen to transit their host star present unique cases where the physical radii of the planet and star can be directly determined via astrometry alone. Planetary albedos and day-night contrast ratios may also be probed via this technique due to the unique signature they impart on the observed astrometric orbits. We develop a tool to examine the prospects for near-term detection of this effect, and give examples of some exoplanets that appear to be good targets for detection in the K to N infrared observing bands, if the required precision can be achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014GMDD....7.7033K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014GMDD....7.7033K&link_type=ABSTRACT"><span id="translatedtitle">14C-<span class="hlt">age</span> tracers in global ocean circulation <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koeve, W.; Wagner, H.; Kähler, P.; Oschlies, A.</p> <p>2014-10-01</p> <p>The natural abundance of 14C in total CO2 dissolved in seawater is a property applied to evaluate the water <span class="hlt">age</span> structure and circulation in the ocean and in ocean <span class="hlt">models</span>. In this study we use three different representations of the global ocean circulation augmented with a suite of idealised tracers to study the potential and limitations of using natural 14C to determine water <span class="hlt">age</span>, the time elapsed since a body of water had contact with the atmosphere. We find that, globally, bulk 14C-<span class="hlt">age</span> is dominated by two equally important components, one associated with <span class="hlt">aging</span>, i.e. the time component of circulation and one associated with a "preformed 14C-<span class="hlt">age</span>". This latter quantity exists because of the slow and incomplete atmosphere/ocean equilibration of 14C in particular in high latitudes where many water masses form. The relative contribution of the preformed component to bulk 14C-<span class="hlt">age</span> varies regionally within a given <span class="hlt">model</span>, but also between <span class="hlt">models</span>. Regional variability, e.g. in the Atlantic Ocean is associated with the mixing of waters with very different end members of preformed 14C-<span class="hlt">age</span>. In the Atlantic, variations in the preformed component over space and time mask the circulation component to an extent that its patterns are not detectable from bulk 14C-<span class="hlt">age</span> alone. Between <span class="hlt">models</span> the variability of <span class="hlt">age</span> can also be considerable (factor of 2), related to the combinations of physical <span class="hlt">model</span> parameters, which influence circulation dynamics, and gas exchange in the <span class="hlt">models</span>. The preformed component was found to be very sensitive to gas exchange and moderately sensitive to ice cover. In our <span class="hlt">model</span> evaluation exercise, the choice of the gas exchange constant from within the current range of uncertainty had such a strong influence on preformed and bulk 14C-<span class="hlt">age</span> that if <span class="hlt">model</span> evaluation would be based on bulk 14C-<span class="hlt">age</span> it could easily impair the evaluation and tuning of a <span class="hlt">models</span> circulation on global and regional scales. Based on the results of this study, we propose that considering</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010OcSci...6..361P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010OcSci...6..361P"><span id="translatedtitle">A <span class="hlt">model</span> for predicting changes in the electrical conductivity, practical salinity, and <span class="hlt">absolute</span> salinity of seawater due to variations in relative chemical composition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pawlowicz, R.</p> <p>2010-03-01</p> <p>Salinity determination in seawater has been carried out for almost 30 years using the Practical Salinity Scale 1978. However, the numerical value of so-called practical salinity, computed from electrical conductivity, differs slightly from the true or <span class="hlt">absolute</span> salinity, defined as the mass of dissolved solids per unit mass of seawater. The difference arises because more recent knowledge about the composition of seawater is not reflected in the definition of practical salinity, which was chosen to maintain historical continuity with previous measures, and because of spatial and temporal variations in the relative composition of seawater. Accounting for these spatial variations in density calculations requires the calculation of a correction factor δSA, which is known to range from 0 to 0.03 g kg-1 in the world oceans. Here a mathematical <span class="hlt">model</span> relating compositional perturbations to δSA is developed, by combining a chemical <span class="hlt">model</span> for the composition of seawater with a mathematical <span class="hlt">model</span> for predicting the conductivity of multi-component aqueous solutions. <span class="hlt">Model</span> calculations for this estimate of δSA, denoted δSRsoln, generally agree with estimates of δSA based on fits to direct density measurements, denoted δSRdens, and show that biogeochemical perturbations affect conductivity only weakly. However, small systematic differences between <span class="hlt">model</span> and density-based estimates remain. These may arise for several reasons, including uncertainty about the biogeochemical processes involved in the increase in Total Alkalinity in the North Pacific, uncertainty in the carbon content of IAPSO standard seawater, and uncertainty about the haline contraction coefficient for the constituents involved in biogeochemical processes. This <span class="hlt">model</span> may then be important in constraining these processes, as well as in future efforts to improve parameterizations for δSA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009OcScD...6.2861P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009OcScD...6.2861P"><span id="translatedtitle">A <span class="hlt">model</span> for predicting changes in the electrical conductivity, practical salinity, and <span class="hlt">absolute</span> salinity of seawater due to variations in relative chemical composition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pawlowicz, R.</p> <p>2009-11-01</p> <p>Salinity determination in seawater has been carried out for almost 30 years using the 1978 Practical Salinity Standard. However, the numerical value of so-called practical salinity, computed from electrical conductivity, differs slightly from the true or <span class="hlt">absolute</span> salinity, defined as the mass of dissolved solids per unit mass of seawater. The difference arises because more recent knowledge about the composition of seawater is not reflected in the definition of practical salinity, which was chosen to maintain historical continuity with previous measures, and because of spatial and temporal variations in the relative composition of seawater. Accounting for these variations in density calculations requires the calculation of a correction factor δSA, which is known to range from 0 to 0.03 g kg-1 in the world oceans. Here a mathematical <span class="hlt">model</span> relating compositional perturbations to δSA is developed, by combining a chemical <span class="hlt">model</span> for the composition of seawater with a mathematical <span class="hlt">model</span> for predicting the conductivity of multi-component aqueous solutions. <span class="hlt">Model</span> calculations generally agree with estimates of δSA based on fits to direct density measurements, and show that biogeochemical perturbations affect conductivity only weakly. However, small systematic differences between <span class="hlt">model</span> and density-based estimates remain. These may arise for several reasons, including uncertainty about the biogeochemical processes involved in the increase in Total Alkalinity in the North Pacific, uncertainty in the carbon content of IAPSO standard seawater, and uncertainty about the haline contraction coefficient for the constituents involved in biogeochemical processes. This <span class="hlt">model</span> may then be important in constraining these processes, as well as in future efforts to improve parameterizations for δSA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013051','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013051"><span id="translatedtitle">Electronic <span class="hlt">Absolute</span> Cartesian Autocollimator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Leviton, Douglas B.</p> <p>2006-01-01</p> <p>An electronic <span class="hlt">absolute</span> Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term <span class="hlt">absolute</span> in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based <span class="hlt">absolutely</span> on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic <span class="hlt">absolute</span> Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26549639','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26549639"><span id="translatedtitle"><span class="hlt">Aging</span> mechanism in <span class="hlt">model</span> Pickering emulsion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fouilloux, Sarah; Malloggi, Florent; Daillant, Jean; Thill, Antoine</p> <p>2016-01-21</p> <p>We study the stability of a <span class="hlt">model</span> Pickering emulsion system using fluorinated oil and functionalized silica nanoparticles. A special counter-flow microfluidic set-up was used to prepare monodisperse oil droplets in water. The wettability of the monodisperse silica nanoparticles (NPs) could be tuned by surface grafting and the surface coverage of the droplets was controlled using the microfluidic setup. For surface coverage as low as 23%, we observed a regime of Pickering emulsion stability where the surface coverage of emulsion droplets of constant size increases with time, coexisting with an excess of oil phase. Our results demonstrate that the previously observed limited coalescence regime where surface coverage tends to control the average size of the final droplets must be put in a broader perspective. PMID:26549639</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20723030','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20723030"><span id="translatedtitle"><span class="hlt">Absolute</span> solvation free energy of Li{sup +} and Na{sup +} ions in dimethyl sulfoxide solution: A theoretical ab initio and cluster-continuum <span class="hlt">model</span> study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Westphal, Eduard; Pliego, Josefredo R. Jr.</p> <p>2005-08-15</p> <p>The solvation of the lithium and sodium ions in dimethyl sulfoxide solution was theoretically investigated using ab initio calculations coupled with the hybrid cluster-continuum <span class="hlt">model</span>, a quasichemical theory of solvation. We have investigated clusters of ions with up to five dimethyl sulfoxide (DMSO) molecules, and the bulk solvent was described by a dielectric continuum <span class="hlt">model</span>. Our results show that the lithium and sodium ions have four and five DMSO molecules into the first coordination shell, and the calculated solvation free energies are -135.5 and -108.6 kcal mol{sup -1}, respectively. These data suggest a solvation free energy value of -273.2 kcal mol{sup -1} for the proton in dimethyl sulfoxide solution, a value that is more negative than the present uncertain experimental value. This and previous studies on the solvation of ions in water solution indicate that the tetraphenylarsonium tetraphenylborate assumption is flawed and the <span class="hlt">absolute</span> value of the free energy of transfer of ions from water to DMSO solution is higher than the present experimental values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27293889','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27293889"><span id="translatedtitle"><span class="hlt">Modeling</span> <span class="hlt">Age</span>-Friendly Environment, Active <span class="hlt">Aging</span>, and Social Connectedness in an Emerging Asian Economy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lai, Ming-Ming; Lein, Shi-Ying; Lau, Siok-Hwa; Lai, Ming-Ling</p> <p>2016-01-01</p> <p>This paper empirically tested eight key features of WHO guidelines to <span class="hlt">age</span>-friendly community by surveying 211 informal caregivers and 402 self-care adults (<span class="hlt">aged</span> 45 to 85 and above) in Malaysia. We examined the associations of these eight features with active <span class="hlt">aging</span> and social connectedness through exploratory and confirmatory factor analyses. A structural <span class="hlt">model</span> with satisfactory goodness-of-fit indices (CMIN/df = 1.11, RMSEA = 0.02, NFI = 0.97, TLI = 1.00, CFI = 1.00, and GFI = 0.96) indicates that transportation and housing, community support and health services, and outdoor spaces and buildings are statistically significant in creating an <span class="hlt">age</span>-friendly environment. We found a statistically significant positive relationship between an <span class="hlt">age</span>-friendly environment and active <span class="hlt">aging</span>. This relationship is mediated by social connectedness. The results indicate that built environments such as accessible public transportations and housing, affordable and accessible healthcare services, and elderly friendly outdoor spaces and buildings have to be put into place before social environment in building an <span class="hlt">age</span>-friendly environment. Otherwise, the structural barriers would hinder social interactions for the <span class="hlt">aged</span>. The removal of the environmental barriers and improved public transportation services provide short-term solutions to meet the varied and growing needs of the older population. PMID:27293889</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4887625','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4887625"><span id="translatedtitle"><span class="hlt">Modeling</span> <span class="hlt">Age</span>-Friendly Environment, Active <span class="hlt">Aging</span>, and Social Connectedness in an Emerging Asian Economy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lai, Ming-Ming; Lein, Shi-Ying; Lau, Siok-Hwa; Lai, Ming-Ling</p> <p>2016-01-01</p> <p>This paper empirically tested eight key features of WHO guidelines to <span class="hlt">age</span>-friendly community by surveying 211 informal caregivers and 402 self-care adults (<span class="hlt">aged</span> 45 to 85 and above) in Malaysia. We examined the associations of these eight features with active <span class="hlt">aging</span> and social connectedness through exploratory and confirmatory factor analyses. A structural <span class="hlt">model</span> with satisfactory goodness-of-fit indices (CMIN/df = 1.11, RMSEA = 0.02, NFI = 0.97, TLI = 1.00, CFI = 1.00, and GFI = 0.96) indicates that transportation and housing, community support and health services, and outdoor spaces and buildings are statistically significant in creating an <span class="hlt">age</span>-friendly environment. We found a statistically significant positive relationship between an <span class="hlt">age</span>-friendly environment and active <span class="hlt">aging</span>. This relationship is mediated by social connectedness. The results indicate that built environments such as accessible public transportations and housing, affordable and accessible healthcare services, and elderly friendly outdoor spaces and buildings have to be put into place before social environment in building an <span class="hlt">age</span>-friendly environment. Otherwise, the structural barriers would hinder social interactions for the <span class="hlt">aged</span>. The removal of the environmental barriers and improved public transportation services provide short-term solutions to meet the varied and growing needs of the older population. PMID:27293889</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhRvE..60.3234O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhRvE..60.3234O"><span id="translatedtitle">Exact solution of an evolutionary <span class="hlt">model</span> without <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Onody, Roberto N.; de Medeiros, Nazareno G. F.</p> <p>1999-09-01</p> <p>We introduce an <span class="hlt">age</span>-structured asexual population <span class="hlt">model</span> containing all the relevant features of evolutionary <span class="hlt">aging</span> theories. Beneficial as well as deleterious mutations, heredity, and arbitrary fecundity are present and managed by natural selection. An exact solution without <span class="hlt">aging</span> is found. We show that fertility is associated with generalized forms of the Fibonacci sequence, while mutations and natural selection are merged into an integral equation which is solved by Fourier series. Average survival probabilities and Malthusian growth exponents are calculated and indicate that the system may exhibit mutational meltdown. The relevance of the <span class="hlt">model</span> in the context of fissile reproduction groups like many protozoa and coelenterates is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22720504R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22720504R"><span id="translatedtitle">Dynamical Masses Demonstrate the Discordant <span class="hlt">Model</span> <span class="hlt">Ages</span> for Upper Scorpius</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rizzuto, Aaron C.; Ireland, Michael; Kraus, Adam L.; Dupuy, Trent J.</p> <p>2016-01-01</p> <p>We present the results of a long term orbit monitoring program, using sparse aperture masking observations taken with NIRC2 on the Keck-II telescope, of seven G to M-type members of the Upper Scorpius subgroup of the Sco-Cen OB association. We present astrometry and derived orbital elements of the binary systems we have monitored, and also determine the <span class="hlt">age</span>, component masses, distance and reddening for each system using the orbital solutions and multi-band photometry, including Hubble Space Telescope photometry, and a Bayesian fitting procedure. We find that the <span class="hlt">models</span> can be forced into agreement with any individual system by assuming an <span class="hlt">age</span>, but that ageis not consistent across the mass range of our sample. The G-type binary systems in our sample have <span class="hlt">model</span> <span class="hlt">ages</span> of ~11.5 Myr, which is consistent with the latest <span class="hlt">age</span> estimates for Upper Scorpius, while the M-type binary systems have significantly younger <span class="hlt">model</span> <span class="hlt">ages</span> of ~7 Myr. Based on our fits to the data, this <span class="hlt">age</span> discrepancy in the <span class="hlt">models</span> corresponds to a luminosity under-prediction of 0.8-0.15 dex, or equivalently an effective temperature over-prediction of 100-300 K for M-type stars at a given premain-sequence <span class="hlt">age</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4422641','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4422641"><span id="translatedtitle">The Development of Small Primate <span class="hlt">Models</span> for <span class="hlt">Aging</span> Research</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fischer, Kathleen E.; Austad, Steven N.</p> <p>2015-01-01</p> <p>Nonhuman primate (NHP) <span class="hlt">aging</span> research has traditionally relied mainly on the rhesus macaque. But the long lifespan, low reproductive rate, and relatively large body size of macaques and related Old World monkeys make them less than ideal <span class="hlt">models</span> for <span class="hlt">aging</span> research. Manifold advantages would attend the use of smaller, more rapidly developing, shorter-lived NHP species in <span class="hlt">aging</span> studies, not the least of which are lower cost and the ability to do shorter research projects. Arbitrarily defining “small” primates as those weighing less than 500 g, we assess small, relatively short-lived species among the prosimians and callitrichids for suitability as <span class="hlt">models</span> for human <span class="hlt">aging</span> research. Using the criteria of availability, knowledge about (and ease of) maintenance, the possibility of genetic manipulation (a hallmark of 21st century biology), and similarities to humans in the physiology of <span class="hlt">age</span>-related changes, we suggest three species—two prosimians (Microcebus murinus and Galago senegalensis) and one New World monkey (Callithrix jacchus)—that deserve scrutiny for development as major NHP <span class="hlt">models</span> for <span class="hlt">aging</span> studies. We discuss one other New World monkey group, Cebus spp., that might also be an effective NHP <span class="hlt">model</span> of <span class="hlt">aging</span> as these species are longer-lived for their body size than any primate except humans. PMID:21411860</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..717D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..717D"><span id="translatedtitle"><span class="hlt">Absolute</span> magnitudes of trans-neptunian objects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duffard, R.; Alvarez-candal, A.; Pinilla-Alonso, N.; Ortiz, J. L.; Morales, N.; Santos-Sanz, P.; Thirouin, A.</p> <p>2015-10-01</p> <p>Accurate measurements of diameters of trans- Neptunian objects are extremely complicated to obtain. Radiomatric techniques applied to thermal measurements can provide good results, but precise <span class="hlt">absolute</span> magnitudes are needed to constrain diameters and albedos. Our objective is to measure accurate <span class="hlt">absolute</span> magnitudes for a sample of trans- Neptunian objects, many of which have been observed, and <span class="hlt">modelled</span>, by the "TNOs are cool" team, one of Herschel Space Observatory key projects grantes with ~ 400 hours of observing time. We observed 56 objects in filters V and R, if possible. These data, along with data available in the literature, was used to obtain phase curves and to measure <span class="hlt">absolute</span> magnitudes by assuming a linear trend of the phase curves and considering magnitude variability due to rotational light-curve. In total we obtained 234 new magnitudes for the 56 objects, 6 of them with no reported previous measurements. Including the data from the literature we report a total of 109 <span class="hlt">absolute</span> magnitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/921934','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/921934"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> POLARIMETRY AT RHIC.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.</p> <p>2007-09-10</p> <p>Precise and <span class="hlt">absolute</span> beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The <span class="hlt">absolute</span> polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26362219','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26362219"><span id="translatedtitle">The heuristic value of redundancy <span class="hlt">models</span> of <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boonekamp, Jelle J; Briga, Michael; Verhulst, Simon</p> <p>2015-11-01</p> <p>Molecular studies of <span class="hlt">aging</span> aim to unravel the cause(s) of <span class="hlt">aging</span> bottom-up, but linking these mechanisms to organismal level processes remains a challenge. We propose that complementary top-down data-directed <span class="hlt">modelling</span> of organismal level empirical findings may contribute to developing these links. To this end, we explore the heuristic value of redundancy <span class="hlt">models</span> of <span class="hlt">aging</span> to develop a deeper insight into the mechanisms causing variation in senescence and lifespan. We start by showing (i) how different redundancy <span class="hlt">model</span> parameters affect projected <span class="hlt">aging</span> and mortality, and (ii) how variation in redundancy <span class="hlt">model</span> parameters relates to variation in parameters of the Gompertz equation. Lifestyle changes or medical interventions during life can modify mortality rate, and we investigate (iii) how interventions that change specific redundancy parameters within the <span class="hlt">model</span> affect subsequent mortality and actuarial senescence. Lastly, as an example of data-directed <span class="hlt">modelling</span> and the insights that can be gained from this, (iv) we fit a redundancy <span class="hlt">model</span> to mortality patterns observed by Mair et al. (2003; Science 301: 1731-1733) in Drosophila that were subjected to dietary restriction and temperature manipulations. Mair et al. found that dietary restriction instantaneously reduced mortality rate without affecting <span class="hlt">aging</span>, while temperature manipulations had more transient effects on mortality rate and did affect <span class="hlt">aging</span>. We show that after adjusting <span class="hlt">model</span> parameters the redundancy <span class="hlt">model</span> describes both effects well, and a comparison of the parameter values yields a deeper insight in the mechanisms causing these contrasting effects. We see replacement of the redundancy <span class="hlt">model</span> parameters by more detailed sub-<span class="hlt">models</span> of these parameters as a next step in linking demographic patterns to underlying molecular mechanisms. PMID:26362219</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4464166','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4464166"><span id="translatedtitle">Invertebrates as <span class="hlt">model</span> organisms for research on <span class="hlt">aging</span> biology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Murthy, Mahadev; Ram, Jeffrey L.</p> <p>2015-01-01</p> <p>Invertebrate <span class="hlt">model</span> systems, such as nematodes and fruit flies, have provided valuable information about the genetics and cellular biology involved in <span class="hlt">aging</span>. However, limitations of these simple, genetically tractable organisms suggest the need for other <span class="hlt">model</span> systems, some of them invertebrate, to facilitate further advances in the understanding of mechanisms of <span class="hlt">aging</span> and longevity in mammals, including humans. This paper introduces 10 review articles about the use of invertebrate <span class="hlt">model</span> systems for the study of <span class="hlt">aging</span> by authors who participated in an ‘NIA-NIH symposium on <span class="hlt">aging</span> in invertebrate <span class="hlt">model</span> systems’ at the 2013 International Congress for Invertebrate Reproduction and Development. In contrast to the highly derived characteristics of nematodes and fruit flies as members of the superphylum Ecdysozoa, cnidarians, such as Hydra, are more ‘basal’ organisms that have a greater number of genetic orthologs in common with humans. Moreover, some other new <span class="hlt">model</span> systems, such as the urochordate Botryllus schlosseri, the tunicate Ciona, and the sea urchins (Echinodermata) are members of the Deuterostomia, the same superphylum that includes all vertebrates, and thus have mechanisms that are likely to be more closely related to those occurring in humans. Additional characteristics of these new <span class="hlt">model</span> systems, such as the recent development of new molecular and genetic tools and a more similar pattern to humans of regeneration and stem cell function suggest that these new <span class="hlt">model</span> systems may have unique advantages for the study of mechanisms of <span class="hlt">aging</span> and longevity. PMID:26241448</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8879R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8879R"><span id="translatedtitle">A new <span class="hlt">age</span> <span class="hlt">model</span> for the early-middle Miocene in the North Alpine Foreland Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reichenbacher, Bettina; Krijgsman, Wout; Pippèrr, Martina; Sant, Karin; Kirscher, Uwe</p> <p>2016-04-01</p> <p>The establishment of high-resolution <span class="hlt">age</span> <span class="hlt">models</span> for sedimentary successions is crucial for numerous research questions in the geosciences and related disciplines. Such <span class="hlt">models</span> provide an <span class="hlt">absolute</span> chronology that permits precise dating of depositional episodes and related processes such as mountain uplift or climate change. Recently, our work in the Miocene sediments of the North Alpine Foreland Basin (NAFB) has revealed a significantly younger <span class="hlt">age</span> (16.6 Myr) for sediments that were thought to have been deposited 18 Myr ago. This implies that a fundamentally revised new <span class="hlt">age</span> <span class="hlt">model</span> is needed for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB (20 to 15-Myr). Our new data also indicate that previously published reconstructions of early-middle Miocene palaeogeography, sedimentation dynamics, mountain uplift and climate change in the NAFB all require a critical review and revision. Further, the time-span addressed is of special interest, since it encompasses the onset of a global warming phase. However, it appears that a fundamentally revised new <span class="hlt">age</span> <span class="hlt">model</span> for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB can only be achieved based on a 500 m deep drilling in the NAFB for which we currently seek collaboration partners to develop a grant application to the International Continental Deep Drilling Program (ICDP). Reference: Reichenbacher, B., W. Krijgsman, Y. Lataster, M. Pippèrr, C. G. C. Van Baak, L. Chang, D. Kälin, J. Jost, G. Doppler, D. Jung, J. Prieto, H. Abdul Aziz, M. Böhme, J. Garnish, U. Kirscher, and V. Bachtadse. 2013. A new magnetostratigraphic framework for the Lower Miocene (Burdigalian/Ottnangian, Karpatian) in the North Alpine Foreland Basin. Swiss Journal of Geosciences 106:309-334.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1850850','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1850850"><span id="translatedtitle"><span class="hlt">Age</span>-related Cardiac Disease <span class="hlt">Model</span> of Drosophila</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ocorr, Karen; Akasaka, Takeshi; Bodmer, Rolf</p> <p>2007-01-01</p> <p>We have begun to study the genetic basis of deterioration of cardiac function in the fruit fly Drosophila melanogaster as an <span class="hlt">age</span>-related cardiac disease <span class="hlt">model</span>. For this purpose we have developed heart function assays in Drosophila and found that the fly's cardiac performance, as that of the human heart, deteriorates with <span class="hlt">age</span>: <span class="hlt">aging</span> fruit flies exhibit a progressive increase in electrical pacing-induced heart failure as well as in arrhythmias. The insulin receptor and associated pathways have a dramatic and heart-autonomous influence on <span class="hlt">age</span>-related cardiac performance in flies, suggestive of potentially similar mechanisms in regulating cardiac <span class="hlt">aging</span> in vertebrates. Compromised KCNQ and KATP ion channel functions also seem to contribute to the decline in heart performance in <span class="hlt">aging</span> flies, suggesting that the corresponding vertebrate gene functions may similarly decline with <span class="hlt">age</span>, in addition to their conserved role in protecting against arrhythmias and hypoxia/ischemia, respectively. The fly heart is thus emerging as a promising genetic <span class="hlt">model</span> for studying the <span class="hlt">age</span>-dependent decline in organ function. PMID:17125816</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3501803','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3501803"><span id="translatedtitle">Active <span class="hlt">Ageing</span>: An Empirical Approach to the WHO <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Paúl, Constança; Ribeiro, Oscar; Teixeira, Laetitia</p> <p>2012-01-01</p> <p>Background. In the beginning of the 21st century, the world summit on population taking place in Madrid approved active <span class="hlt">ageing</span>, WHO (2002) as the main objective of health and social policies for old people. Few studies have been done on the scientific validity of the construct. This study aims to validate the construct of active <span class="hlt">ageing</span> and test empirically the WHO (2002) <span class="hlt">model</span> of Active <span class="hlt">Ageing</span> in a sample of community-dwelling seniors. Methods. 1322 old people living in the community were interviewed using an extensive assessment protocol to measure WHO's determinants of active <span class="hlt">ageing</span> and performed an exploratory factor analysis followed by a confirmatory factor analyses. Results. We did not confirm the active <span class="hlt">ageing</span> <span class="hlt">model</span>, as most of the groups of determinants are either not independent or not significant. We got to a six-factor <span class="hlt">model</span> (health, psychological component, cognitive performance, social relationships, biobehavioural component, and personality) explaining 54.6% of total variance. Conclusion. The present paper shows that there are objective as well as subjective variables contributing to active <span class="hlt">ageing</span> and that psychological variables seem to give a very important contribute to the construct. The profile of active <span class="hlt">ageing</span> is expected to vary between contexts and cultures and can be used to guide specific community and individually based interventions. PMID:23193396</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26814019','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26814019"><span id="translatedtitle"><span class="hlt">Age</span>-space-time CAR <span class="hlt">models</span> in Bayesian disease mapping.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goicoa, T; Ugarte, M D; Etxeberria, J; Militino, A F</p> <p>2016-06-30</p> <p>Mortality counts are usually aggregated over <span class="hlt">age</span> groups assuming similar effects of both time and region, yet the spatio-temporal evolution of cancer mortality rates may depend on changing <span class="hlt">age</span> structures. In this paper, mortality rates are analyzed by region, time period and <span class="hlt">age</span> group, and <span class="hlt">models</span> including space-time, space-<span class="hlt">age</span>, and <span class="hlt">age</span>-time interactions are considered. The integrated nested Laplace approximation method, known as INLA, is adopted for <span class="hlt">model</span> fitting and inference in order to reduce computing time in comparison with Markov chain Monte Carlo (McMC) methods. The methodology provides full posterior distributions of the quantities of interest while avoiding complex simulation techniques. The proposed <span class="hlt">models</span> are used to analyze prostate cancer mortality data in 50 Spanish provinces over the period 1986-2010. The results reveal a decline in mortality since the late 1990s, particularly in the <span class="hlt">age</span> group [65,70), probably because of the inclusion of the PSA (prostate-specific antigen) test and better treatment of early-stage disease. The decline is not clearly observed in the oldest <span class="hlt">age</span> groups. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26814019</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950032338&hterms=old+age+work&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dold%2Bage%2Bwork','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950032338&hterms=old+age+work&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dold%2Bage%2Bwork"><span id="translatedtitle">Comprehensive stellar population <span class="hlt">models</span> and the disentanglement of <span class="hlt">age</span> and metallicity effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Worthey, Guy</p> <p>1994-01-01</p> <p>The construction of detailed <span class="hlt">models</span> for intermediate and old stellar populations is described. Input parameters include metallicity (-2 less than (Fe/H) less than 0.5), single-burst <span class="hlt">age</span> (between 1.5 and 17 Gyr), and initial mass function (IMF) exponent. Quantities output include broadband magnitudes, spectral energy distributions, surface brightness fluctuation magnitudes, and a suite of 21 absorption feature indices. The <span class="hlt">models</span> are checked against a wide variety of available observations. Examinations of <span class="hlt">model</span> output yield the following conclusions. (1) If the percentage change delta <span class="hlt">age</span>/delta Z approximately equals 3/2 for two populations, they will appear almost identical in most indices. A few indices break this degeneracy by being either more abundance sensitive (Fe4668, Fe5015, Fe5709, and Fe5782) or more <span class="hlt">age</span> sensitive (G4300, H beta, and presumably higher order Balmer lines) than usual. (2) Present uncertainties in stellar evolution are of the same magnitude as the effects of IMF and Y in the indices studied. (3) Changes in abundance ratios (like (Mg/Fe)) are predicted to be readily apparent in the spectra of old stellar populations. (4) The I-band flux of a stellar population is predicted to be nearly independent of metallicity and only modestly sensitive to <span class="hlt">age</span>. The I band is therefore recommended for standard candle work or studies of M/L in galaxies. Other conclusions stem from this work. (1) Intercomparison of <span class="hlt">models</span> and observations of two TiO indices seem to indicate variation of the (V/Ti) ratio among galaxies, but it is not clear how this observation ties into the standard picture of chemical enrichment. (2) Current estimates of (Fe/H) for the most metal-rich globulars that are based on integrated indices are probably slightly too high. (3) Colors of population <span class="hlt">models</span> from different authors exhibit a substantial range. At solar metallicity and 13 Gyr, this range corresponds to an <span class="hlt">age</span> error of roughly +/- 7 Gyr. <span class="hlt">Model</span> colors from different authors</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27364351','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27364351"><span id="translatedtitle">A full-dimensional <span class="hlt">model</span> of ozone forming reaction: the <span class="hlt">absolute</span> value of the recombination rate coefficient, its pressure and temperature dependencies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Teplukhin, Alexander; Babikov, Dmitri</p> <p>2016-07-28</p> <p>Rigorous calculations of scattering resonances in ozone are carried out for a broad range of rotational excitations. The accurate potential energy surface of Dawes is adopted, and a new efficient method for calculations of ro-vibrational energies, wave functions and resonance lifetimes is employed (which uses hyper-spherical coordinates, the sequential diagonalization/truncation approach, grid optimization and complex absorbing potential). A detailed analysis is carried out to characterize distributions of resonance energies and lifetimes, their rotational/vibrational content and their positions with respect to the centrifugal barrier. Emphasis is on the contribution of these resonances to the recombination process that forms ozone. It is found that major contributions come from localized resonances at energies near the top of the barrier. Delocalized resonances at higher energies should also be taken into account, while very narrow resonances at low energies (trapped far behind the centrifugal barrier) should be treated as bound states. The <span class="hlt">absolute</span> value of the recombination rate coefficient, its pressure and temperature dependencies are obtained using the energy-transfer <span class="hlt">model</span> developed in the earlier work. Good agreement with experimental data is obtained if one follows the suggestion of Troe, who argued that the energy transfer mechanism of recombination is responsible only for 55% of the recombination rate (with the remaining 45% coming from the competing chaperon mechanism). PMID:27364351</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21471260','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21471260"><span id="translatedtitle"><span class="hlt">MODELING</span> MULTI-WAVELENGTH STELLAR ASTROMETRY. II. DETERMINING <span class="hlt">ABSOLUTE</span> INCLINATIONS, GRAVITY-DARKENING COEFFICIENTS, AND SPOT PARAMETERS OF SINGLE STARS WITH SIM LITE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coughlin, Jeffrey L.; Harrison, Thomas E.; Gelino, Dawn M.</p> <p>2010-11-10</p> <p>We present a novel technique to determine the <span class="hlt">absolute</span> inclination of single stars using multi-wavelength submilliarcsecond astrometry. The technique exploits the effect of gravity darkening, which causes a wavelength-dependent astrometric displacement parallel to a star's projected rotation axis. We find that this effect is clearly detectable using SIM Lite for various giant stars and rapid rotators, and present detailed <span class="hlt">models</span> for multiple systems using the REFLUX code. We also explore the multi-wavelength astrometric reflex motion induced by spots on single stars. We find that it should be possible to determine spot size, relative temperature, and some positional information for both giant and nearby main-sequence stars utilizing multi-wavelength SIM Lite data. These data will be extremely useful in stellar and exoplanet astrophysics, as well as supporting the primary SIM Lite mission through proper multi-wavelength calibration of the giant star astrometric reference frame, and reduction of noise introduced by starspots when searching for extrasolar planets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26022836','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26022836"><span id="translatedtitle"><span class="hlt">Absolutely</span> relative or relatively <span class="hlt">absolute</span>: violations of value invariance in human decision making.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Teodorescu, Andrei R; Moran, Rani; Usher, Marius</p> <p>2016-02-01</p> <p>Making decisions based on relative rather than <span class="hlt">absolute</span> information processing is tied to choice optimality via the accumulation of evidence differences and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to <span class="hlt">absolute</span> intensities that maintain differences and ratios, respectively. While information about the <span class="hlt">absolute</span> values of the choice alternatives is not necessary for choosing the best alternative, it may nevertheless hold valuable information about the context of the decision. To test the sensitivity of human decision making to <span class="hlt">absolute</span> values, we manipulated the intensities of brightness stimuli pairs while preserving either their differences or their ratios. Although asked to choose the brighter alternative relative to the other, participants responded faster to higher <span class="hlt">absolute</span> values. Thus, our results provide empirical evidence for human sensitivity to task irrelevant <span class="hlt">absolute</span> values indicating a hard-wired mechanism that precedes executive control. Computational investigations of several <span class="hlt">modelling</span> architectures reveal two alternative accounts for this phenomenon, which combine <span class="hlt">absolute</span> and relative processing. One account involves accumulation of differences with activation dependent processing noise and the other emerges from accumulation of <span class="hlt">absolute</span> values subject to the temporal dynamics of lateral inhibition. The potential adaptive role of such choice mechanisms is discussed. PMID:26022836</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16463910','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16463910"><span id="translatedtitle">Implants as <span class="hlt">absolute</span> anchorage.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rungcharassaeng, Kitichai; Kan, Joseph Y K; Caruso, Joseph M</p> <p>2005-11-01</p> <p>Anchorage control is essential for successful orthodontic treatment. Each tooth has its own anchorage potential as well as propensity to move when force is applied. When teeth are used as anchorage, the untoward movements of the anchoring units may result in the prolonged treatment time, and unpredictable or less-than-ideal outcome. To maximize tooth-related anchorage, techniques such as differential torque, placing roots into the cortex of the bone, the use of various intraoral devices and/or extraoral appliances have been implemented. Implants, as they are in direct contact with bone, do not possess a periodontal ligament. As a result, they do not move when orthodontic/orthopedic force is applied, and therefore can be used as "<span class="hlt">absolute</span> anchorage." This article describes different types of implants that have been used as orthodontic anchorage. Their clinical applications and limitations are also discussed. PMID:16463910</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040110742','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040110742"><span id="translatedtitle"><span class="hlt">Absolute</span> Equilibrium Entropy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shebalin, John V.</p> <p>1997-01-01</p> <p>The entropy associated with <span class="hlt">absolute</span> equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GMD.....7..725F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GMD.....7..725F"><span id="translatedtitle">Snow water equivalent <span class="hlt">modeling</span> components in New<span class="hlt">Age</span>-JGrass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Formetta, G.; Kampf, S. K.; David, O.; Rigon, R.</p> <p>2014-05-01</p> <p>This paper presents a package of modified temperature-index-based snow water equivalent <span class="hlt">models</span> as part of the hydrological <span class="hlt">modeling</span> system New<span class="hlt">Age</span>-JGrass. Three temperature-based snow <span class="hlt">models</span> are integrated into the New<span class="hlt">Age</span>-JGrass <span class="hlt">modeling</span> system and use many of its components such as those for radiation balance (short wave radiation balance, SWRB), kriging (KRIGING), automatic calibration algorithms (particle swarm optimization) and tests of goodness of fit (New<span class="hlt">Age</span>-V), to build suitable <span class="hlt">modeling</span> solutions (MS). Similarly to all the New<span class="hlt">Age</span>-JGrass components, the <span class="hlt">models</span> can be executed both in raster and in vector mode. The simulation time step can be daily, hourly or sub-hourly, depending on user needs and availability of input data. The MS are applied on the Cache la Poudre River basin (CO, USA) using three test applications. First, daily snow water equivalent is simulated for three different measurement stations for two snow <span class="hlt">model</span> formulations. Second, hourly snow water equivalent is simulated using all the three different snow <span class="hlt">model</span> formulae. Finally, a raster mode application is performed to compute snow water equivalent maps for the whole Cache la Poudre Basin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27157786','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27157786"><span id="translatedtitle">Mathematically <span class="hlt">modelling</span> the dynamics of cholesterol metabolism and <span class="hlt">ageing</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morgan, A E; Mooney, K M; Wilkinson, S J; Pickles, N A; Mc Auley, M T</p> <p>2016-07-01</p> <p>Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the UK. This condition becomes increasingly prevalent during <span class="hlt">ageing</span>; 34.1% and 29.8% of males and females respectively, over 75 years of <span class="hlt">age</span> have an underlying cardiovascular problem. The dysregulation of cholesterol metabolism is inextricably correlated with cardiovascular health and for this reason low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) are routinely used as biomarkers of CVD risk. The aim of this work was to use mathematical <span class="hlt">modelling</span> to explore how cholesterol metabolism is affected by the <span class="hlt">ageing</span> process. To do this we updated a previously published whole-body mathematical <span class="hlt">model</span> of cholesterol metabolism to include an additional 96 mechanisms that are fundamental to this biological system. Additional mechanisms were added to cholesterol absorption, cholesterol synthesis, reverse cholesterol transport (RCT), bile acid synthesis, and their enterohepatic circulation. The sensitivity of the <span class="hlt">model</span> was explored by the use of both local and global parameter scans. In addition, acute cholesterol feeding was used to explore the effectiveness of the regulatory mechanisms which are responsible for maintaining whole-body cholesterol balance. It was found that our <span class="hlt">model</span> behaves as a hypo-responder to cholesterol feeding, while both the hepatic and intestinal pools of cholesterol increased significantly. The <span class="hlt">model</span> was also used to explore the effects of <span class="hlt">ageing</span> in tandem with three different cholesterol ester transfer protein (CETP) genotypes. <span class="hlt">Ageing</span> in the presence of an atheroprotective CETP genotype, conferring low CETP activity, resulted in a 0.6% increase in LDL-C. In comparison, <span class="hlt">ageing</span> with a genotype reflective of high CETP activity, resulted in a 1.6% increase in LDL-C. Thus, the <span class="hlt">model</span> has illustrated the importance of CETP genotypes such as I405V, and their potential role in healthy <span class="hlt">ageing</span>. PMID:27157786</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhyA..294..191S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhyA..294..191S"><span id="translatedtitle">Justification of sexual reproduction by modified Penna <span class="hlt">model</span> of <span class="hlt">ageing</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sá Martins, J. S.; Stauffer, D.</p> <p>2001-05-01</p> <p>We generalize the standard Penna bit-string <span class="hlt">model</span> of biological <span class="hlt">ageing</span> by assuming that each deleterious mutation diminishes the survival probability in every time interval by a small percentage. This effect is added to the usual lethal but <span class="hlt">age</span>-dependent effect of the same mutation. We then find strong advantages or disadvantages of sexual reproduction (with males and females) compared to asexual cloning, depending on parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRG..120.2473Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRG..120.2473Z"><span id="translatedtitle"><span class="hlt">Age</span>-dependent forest carbon sink: Estimation via inverse <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Tao; Shi, Peijun; Jia, Gensuo; Dai, Yongjiu; Zhao, Xiang; Shangguan, Wei; Du, Ling; Wu, Hao; Luo, Yiqi</p> <p>2015-12-01</p> <p>Forests have been recognized to sequester a substantial amount of carbon (C) from the atmosphere. However, considerable uncertainty remains regarding the magnitude and time course of the C sink. Revealing the intrinsic relationship between forest <span class="hlt">age</span> and C sink is crucial for reducing uncertainties in prediction of forest C sink potential. In this study, we developed a stepwise data assimilation approach to combine a process-based Terrestrial ECOsystem Regional <span class="hlt">model</span>, observations from multiple sources, and stochastic sampling to inversely estimate carbon cycle parameters including carbon sink at different forest <span class="hlt">ages</span> for evergreen needle-leaved forests in China. The new approach is effective to estimate <span class="hlt">age</span>-dependent parameter of maximal light-use efficiency (R2 = 0.99) and, accordingly, can quantify a relationship between forest <span class="hlt">age</span> and the vegetation and soil C sinks. The estimated ecosystem C sink increases rapidly with <span class="hlt">age</span>, peaks at 0.451 kg C m-2 yr-1 at <span class="hlt">age</span> 22 years (ranging from 0.421 to 0.465 kg C m-2 yr-1), and gradually decreases thereafter. The dynamic patterns of C sinks in vegetation and soil are significantly different. C sink in vegetation first increases rapidly with <span class="hlt">age</span> and then decreases. C sink in soil, however, increases continuously with <span class="hlt">age</span>; it acts as a C source when the <span class="hlt">age</span> is less than 20 years, after which it acts as a sink. For the evergreen needle-leaved forest, the highest C sink efficiency (i.e., C sink per unit net primary productivity) is approximately 60%, with <span class="hlt">age</span> between 11 and 43 years. Overall, the inverse estimation of carbon cycle parameters can make reasonable estimates of <span class="hlt">age</span>-dependent C sequestration in forests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JMAA..331.1396Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JMAA..331.1396Z"><span id="translatedtitle">A SIRS epidemic <span class="hlt">model</span> with infection-<span class="hlt">age</span> dependence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Zhonghua; Peng, Jigen</p> <p>2007-07-01</p> <p>Based on J. Mena-Lorca and H.W. Hethcote's epidemic <span class="hlt">model</span>, a SIRS epidemic <span class="hlt">model</span> with infection-<span class="hlt">age</span>-dependent infectivity and general nonlinear contact rate is formulated. Under general conditions, the unique existence of its global positive solutions is obtained. Moreover, under more general assumptions than the existing, the existence and asymptotical stability of its equilibria are discussed. In the end, the condition on the stability of endemic equilibrium is verified by a special <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26325590','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26325590"><span id="translatedtitle">Why is the dog an ideal <span class="hlt">model</span> for <span class="hlt">aging</span> research?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gilmore, Keiva M; Greer, Kimberly A</p> <p>2015-11-01</p> <p>With many caveats to the traditional vertebrate species pertaining to biogerontology investigations, it has been suggested that a most informative <span class="hlt">model</span> is the one which: 1) examines closely related species, or various members of the same species with naturally occurring lifespan variation, 2) already has adequate medical procedures developed, 3) has a well annotated genome, 4) does not require artificial housing, and can live in its natural environment while being investigated, and 5) allows considerable information to be gathered within a relatively short period of time. The domestic dog unsurprisingly fits each criterion mentioned. The dog has already become a key <span class="hlt">model</span> system in which to evaluate surgical techniques and novel medications because of the remarkable similarity between human and canine conditions, treatments, and response to therapy. The dog naturally serves as a disease <span class="hlt">model</span> for study, obviating the need to construct artificial genetically modified examples of disease. Just as the dog offers a natural <span class="hlt">model</span> for human conditions and diseases, simple observation leads to the conclusion that the canine <span class="hlt">aging</span> phenotype also mimics that of the human. Genotype information, biochemical information pertaining to the GH/IGF-1 pathway, and some limited longitudinal investigations have begun the establishment of the domestic dog as a <span class="hlt">model</span> of <span class="hlt">aging</span>. Although we find that dogs indeed are a <span class="hlt">model</span> to study <span class="hlt">aging</span> and there are many independent pieces of canine <span class="hlt">aging</span> data, there are many more "open" areas, ripe for investigation. PMID:26325590</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ACP....13.6329H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ACP....13.6329H"><span id="translatedtitle">Impact of <span class="hlt">aging</span> mechanism on <span class="hlt">model</span> simulated carbonaceous aerosols</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Y.; Wu, S.; Dubey, M. K.; French, N. H. F.</p> <p>2013-07-01</p> <p>Carbonaceous aerosols including organic carbon and black carbon have significant implications for both climate and air quality. In the current global climate or chemical transport <span class="hlt">models</span>, a fixed hydrophobic-to-hydrophilic conversion lifetime for carbonaceous aerosol (τ) is generally assumed, which is usually around one day. We have implemented a new detailed <span class="hlt">aging</span> scheme for carbonaceous aerosols in a chemical transport <span class="hlt">model</span> (GEOS-Chem) to account for both the chemical oxidation and the physical condensation-coagulation effects, where τ is affected by local atmospheric environment including atmospheric concentrations of water vapor, ozone, hydroxyl radical and sulfuric acid. The updated τ exhibits large spatial and temporal variations with the global average (up to 11 km altitude) calculated to be 2.6 days. The chemical <span class="hlt">aging</span> effects are found to be strongest over the tropical regions driven by the low ozone concentrations and high humidity there. The τ resulted from chemical <span class="hlt">aging</span> generally decreases with altitude due to increases in ozone concentration and decreases in humidity. The condensation-coagulation effects are found to be most important for the high-latitude areas, in particular the polar regions, where the τ values are calculated to be up to 15 days. When both the chemical <span class="hlt">aging</span> and condensation-coagulation effects are considered, the total atmospheric burdens and global average lifetimes of BC, black carbon, (OC, organic carbon) are calculated to increase by 9% (3%) compared to the control simulation, with considerable enhancements of BC and OC concentrations in the Southern Hemisphere. <span class="hlt">Model</span> evaluations against data from multiple datasets show that the updated <span class="hlt">aging</span> scheme improves <span class="hlt">model</span> simulations of carbonaceous aerosols for some regions, especially for the remote areas in the Northern Hemisphere. The improvement helps explain the persistent low <span class="hlt">model</span> bias for carbonaceous aerosols in the Northern Hemisphere reported in literature. Further</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013PhRvE..88e2702P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013PhRvE..88e2702P&link_type=ABSTRACT"><span id="translatedtitle">Cellular senescence in the Penna <span class="hlt">model</span> of <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Periwal, Avikar</p> <p>2013-11-01</p> <p>Cellular senescence is thought to play a major role in <span class="hlt">age</span>-related diseases, which cause nearly 67% of all human deaths worldwide. Recent research in mice showed that exercising mice had higher levels of telomerase, an enzyme that helps maintain telomere length, than nonexercising mice. A commonly used <span class="hlt">model</span> for biological <span class="hlt">aging</span> was proposed by Penna. I propose a modification of the Penna <span class="hlt">model</span> that incorporates cellular senescence and find an analytical steady-state solution following Coe, Mao, and Cates [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.89.288103 89, 288103 (2002)]. I find that <span class="hlt">models</span> corresponding to delayed cellular senescence have younger populations that live longer. I fit the <span class="hlt">model</span> to the United Kingdom's death distribution, which the original Penna <span class="hlt">model</span> cannot do.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25750699','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25750699"><span id="translatedtitle">Computationally <span class="hlt">Modeling</span> Lipid Metabolism and <span class="hlt">Aging</span>: A Mini-review.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mc Auley, Mark T; Mooney, Kathleen M</p> <p>2015-01-01</p> <p>One of the greatest challenges in biology is to improve the understanding of the mechanisms which underpin <span class="hlt">aging</span> and how these affect health. The need to better understand <span class="hlt">aging</span> is amplified by demographic changes, which have caused a gradual increase in the global population of older people. <span class="hlt">Aging</span> western populations have resulted in a rise in the prevalence of <span class="hlt">age</span>-related pathologies. Of these diseases, cardiovascular disease is the most common underlying condition in older people. The dysregulation of lipid metabolism due to <span class="hlt">aging</span> impinges significantly on cardiovascular health. However, the multifaceted nature of lipid metabolism and the complexities of its interaction with <span class="hlt">aging</span> make it challenging to understand by conventional means. To address this challenge computational <span class="hlt">modeling</span>, a key component of the systems biology paradigm is being used to study the dynamics of lipid metabolism. This mini-review briefly outlines the key regulators of lipid metabolism, their dysregulation, and how computational <span class="hlt">modeling</span> is being used to gain an increased insight into this system. PMID:25750699</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4348429','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4348429"><span id="translatedtitle">Computationally <span class="hlt">Modeling</span> Lipid Metabolism and <span class="hlt">Aging</span>: A Mini-review</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mc Auley, Mark T.; Mooney, Kathleen M.</p> <p>2014-01-01</p> <p>One of the greatest challenges in biology is to improve the understanding of the mechanisms which underpin <span class="hlt">aging</span> and how these affect health. The need to better understand <span class="hlt">aging</span> is amplified by demographic changes, which have caused a gradual increase in the global population of older people. <span class="hlt">Aging</span> western populations have resulted in a rise in the prevalence of <span class="hlt">age</span>-related pathologies. Of these diseases, cardiovascular disease is the most common underlying condition in older people. The dysregulation of lipid metabolism due to <span class="hlt">aging</span> impinges significantly on cardiovascular health. However, the multifaceted nature of lipid metabolism and the complexities of its interaction with <span class="hlt">aging</span> make it challenging to understand by conventional means. To address this challenge computational <span class="hlt">modeling</span>, a key component of the systems biology paradigm is being used to study the dynamics of lipid metabolism. This mini-review briefly outlines the key regulators of lipid metabolism, their dysregulation, and how computational <span class="hlt">modeling</span> is being used to gain an increased insight into this system. PMID:25750699</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26478959','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26478959"><span id="translatedtitle">Stimulus probability effects in <span class="hlt">absolute</span> identification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kent, Christopher; Lamberts, Koen</p> <p>2016-05-01</p> <p>This study investigated the effect of stimulus presentation probability on accuracy and response times in an <span class="hlt">absolute</span> identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of presentation probability on both proportion correct and response times. The effects were moderated by the ubiquitous stimulus position effect. The accuracy and response time data were predicted by an exemplar-based <span class="hlt">model</span> of perceptual cognition (Kent & Lamberts, 2005). The bow in discriminability was also attenuated when presentation probability for middle items was relatively high, an effect that will constrain future <span class="hlt">model</span> development. The study provides evidence for item-specific learning in <span class="hlt">absolute</span> identification. Implications for other theories of <span class="hlt">absolute</span> identification are discussed. (PsycINFO Database Record PMID:26478959</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035501','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035501"><span id="translatedtitle">An evaluation of sex-<span class="hlt">age</span>-kill (SAK) <span class="hlt">model</span> performance</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Millspaugh, Joshua J.; Skalski, John R.; Townsend, Richard L.; Diefenbach, Duane R.; Boyce, Mark S.; Hansen, Lonnie P.; Kammermeyer, Kent</p> <p>2009-01-01</p> <p>The sex-<span class="hlt">age</span>-kill (SAK) <span class="hlt">model</span> is widely used to estimate abundance of harvested large mammals, including white-tailed deer (Odocoileus virginianus). Despite a long history of use, few formal evaluations of SAK performance exist. We investigated how violations of the stable <span class="hlt">age</span> distribution and stationary population assumption, changes to male or female harvest, stochastic effects (i.e., random fluctuations in recruitment and survival), and sampling efforts influenced SAK estimation. When the simulated population had a stable <span class="hlt">age</span> distribution and λ > 1, the SAK <span class="hlt">model</span> underestimated abundance. Conversely, when λ < 1, the SAK overestimated abundance. When changes to male harvest were introduced, SAK estimates were opposite the true population trend. In contrast, SAK estimates were robust to changes in female harvest rates. Stochastic effects caused SAK estimates to fluctuate about their equilibrium abundance, but the effect dampened as the size of the surveyed population increased. When we considered both stochastic effects and sampling error at a deer management unit scale the resultant abundance estimates were within ±121.9% of the true population level 95% of the time. These combined results demonstrate extreme sensitivity to <span class="hlt">model</span> violations and scale of analysis. Without changes to <span class="hlt">model</span> formulation, the SAK <span class="hlt">model</span> will be biased when λ ≠ 1. Furthermore, any factor that alters the male harvest rate, such as changes to regulations or changes in hunter attitudes, will bias population estimates. Sex-<span class="hlt">age</span>-kill estimates may be precise at large spatial scales, such as the state level, but less so at the individual management unit level. Alternative <span class="hlt">models</span>, such as statistical <span class="hlt">age</span>-at-harvest <span class="hlt">models</span>, which require similar data types, might allow for more robust, broad-scale demographic assessments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70156592','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70156592"><span id="translatedtitle">Development of a bioenergetics <span class="hlt">model</span> for <span class="hlt">age</span>-0 American Shad</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sauter, Sally T.</p> <p>2011-01-01</p> <p>Bioenergetics <span class="hlt">modeling</span> can be used as a tool to investigate the impact of non-native <span class="hlt">age</span>-0 American shad (<i>Alosa sapidissima</i>) on reservoir and estuary food webs. The <span class="hlt">model</span> can increase our understanding of how these fish influence lower trophic levels as well as predatory fish populations that feed on juvenile salmonids. Bioenergetics <span class="hlt">modeling</span> can be used to investigate ecological processes, evaluate alternative research hypotheses, provide decision support, and quantitative prediction. Bioenergetics <span class="hlt">modeling</span> has proven to be extremely useful in fisheries research (Ney et al. 1993,Chips and Wahl 2008, Petersen et al. 2008). If growth and diet parameters are known, the bioenergetics <span class="hlt">model</span> can be used to quantify the relative amount of zooplankton or insects consumed by <span class="hlt">age</span>-0 American shad. When linked with spatial and temporal information on fish abundance, <span class="hlt">model</span> output can guide inferential hypothesis development to demonstrate where the greatest impacts of <span class="hlt">age</span>-0 American shad might occur.</p> <br/> <p>Bioenergetics <span class="hlt">modeling</span> is particularly useful when research questions involve multiple species and trophic levels (e.g. plankton communities). Bioenergetics <span class="hlt">models</span> are mass-balance equations where the energy acquired from food is partitioned between maintenance costs, waste products, and growth (Winberg 1956). Specifically, the Wisconsin bioenergetics <span class="hlt">model</span> (Hanson et al. 1997) is widely used in fisheries science. Researchers have extensively tested, reviewed, and improved on this <span class="hlt">modeling</span> approach for over 30 years (Petersen et al. 2008). Development of a bioenergetics <span class="hlt">model</span> for any species requires three key components: 1) determine physiological parameters for the <span class="hlt">model</span> through laboratory experiments or incorporate data from a closely related species, 2) corroboration of the <span class="hlt">model</span> with growth and consumption estimates from independent research, and 3) error analysis of <span class="hlt">model</span> parameters.</p> <br/> <p>Wisconsin bioenergetics <span class="hlt">models</span> have been parameterized for</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16352410','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16352410"><span id="translatedtitle">Recent female mouse <span class="hlt">models</span> displaying advanced reproductive <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Danilovich, Natalia; Ram Sairam, M</p> <p>2006-02-01</p> <p>Reproductive senescence occurs in all female mammals with resultant changes in numerous body functional systems and several important features may be species-specific. Those features that appear to parallel human menopause and <span class="hlt">aging</span> include general similarity of hormone profiles across the menopausal transition, progression to cycle termination through irregular cycles, declining fertility with <span class="hlt">age</span>, disturbances in thermogenesis, <span class="hlt">age</span>-related gains in body weight, fat distribution and disposition towards metabolic syndrome. Structural and hormonal changes in the brain and ovary play a critical role in determining the onset of reproductive senescence. The short life span of rodents such as mice (compared to humans) and the ability to generate specific and timed gene deletions, provide powerful experimental paradigms to understand the molecular and functional changes that precede and follow the loss of reproductive capacity. In theory, any manipulation that compromises ovarian function either partly or totally would impact reproductive events at various levels followed by other dysfunctions. In this article, we provide an overview of three mouse <span class="hlt">models</span> for the study of female reproductive <span class="hlt">aging</span>. They are derived from different strategies and their <span class="hlt">age</span> related phenotypes have been characterized to varying degrees. The follitropin receptor knockout (FORKO) mouse, in its null and haploinsufficient state as well as the dioxin/aryl hydrocarbon receptor (AhR) knockout mouse, serve as two examples of single gene deletions. A third <span class="hlt">model</span>, using administration of a chemical toxicant such as 4-vinylcyclohexene diepoxide (VCD) in the adult state, produces ovarian deficiencies accompanied by <span class="hlt">aging</span> changes. These will serve as useful alternatives to previously used radical ovariectomy in young adults. It is anticipated that these new <span class="hlt">models</span> and more that will be forthcoming will extend opportunities to understand reproductive <span class="hlt">aging</span> and resolve controversies that abound on issues</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26748955','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26748955"><span id="translatedtitle">Reconciling Two Computational <span class="hlt">Models</span> of Working Memory in <span class="hlt">Aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoareau, Violette; Lemaire, Benoît; Portrat, Sophie; Plancher, Gaën</p> <p>2016-01-01</p> <p>It is well known that working memory performance changes with <span class="hlt">age</span>. Two recent computational <span class="hlt">models</span> of working memory, TBRS* and SOB-CS, developed from young adults WM performances are opposed regarding the postulated causes of forgetting, namely time-based decay and interference for TBRS* and SOB-CS, respectively. In the present study, these <span class="hlt">models</span> are applied on a set of complex span data produced by young and older adults. As expected, these <span class="hlt">models</span> are unable to account for the older adult data. An investigation on the effect of the main parameters of these <span class="hlt">models</span> showed that the poorer performance of older adults does not come from a weaker encoding of item but rather from difficulties during the free time that immediately follows each distractor, as well as from a higher level of confusion between items. These results are discussed with respect to the current theories of working memory and <span class="hlt">aging</span>. PMID:26748955</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7766791','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7766791"><span id="translatedtitle">Testing a <span class="hlt">model</span> of <span class="hlt">aging</span> in animal experiments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tyurin YuN; Yakovlev AYu; Shi, J; Bass, L</p> <p>1995-03-01</p> <p>A stochastic <span class="hlt">model</span> of <span class="hlt">aging</span> is developed in terms of accumulation and expression of intracellular lesions caused by environment or intrinsic genetic program. In contrast to the commonly used Gompertz-Makeham approach to the parametric analysis of mortality data, the <span class="hlt">model</span> yields a hazard function that is bounded from above. For testing the <span class="hlt">model</span> in experiments aimed at studying animal longevity, a Kolmogorov-type statistical test is presented with regard to the hypothesis involving unknown parameters. Examples concerning longevity of intact animals of two different species, as well as the effect of a prolonged irradiation at a low dose rate, are given to illustrate the <span class="hlt">model</span> application and goodness-of-fit testing. The results of the analysis of published data show that the rate of lesion formation is not sustained at a constant level throughout life, though in some cases its variations with <span class="hlt">age</span> can be considered negligible. PMID:7766791</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRB..120.6758A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRB..120.6758A"><span id="translatedtitle">Magneto- and cyclostratigraphy in the red clay sequence: New <span class="hlt">age</span> <span class="hlt">model</span> and paleoclimatic implication for the eastern Chinese Loess Plateau</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anwar, Taslima; Kravchinsky, Vadim A.; Zhang, Rui</p> <p>2015-10-01</p> <p>The Chinese Loess Plateau red clay sequences display a continuous alternation of sedimentary cycles that represent recurrent climatic fluctuations from 2.58 Ma to the Miocene. Deciphering such a record can provide us with vital information on global and Asian climatic variations. Lack of fossils and failure of <span class="hlt">absolute</span> dating methods made magnetostratigraphy a leading method to build <span class="hlt">age</span> <span class="hlt">models</span> for the red clay sequences. Here we test the magnetostratigraphic <span class="hlt">age</span> <span class="hlt">model</span> against cyclostratigraphy. For this purpose we investigate the climate cyclicity recorded in magnetic susceptibility and sedimentary grain size in a red clay section previously dated 11 Myr old with magnetostratigraphy alone. Magnetostratigraphy dating based on only visual correlation could potentially lead to erroneous <span class="hlt">age</span> <span class="hlt">model</span>. In this study the correlation is executed through the iteration procedure until it is supported by cyclostratigraphy; i.e., Milankovitch cycles are resolved in the best possible manner. Our new <span class="hlt">age</span> <span class="hlt">model</span> provides an <span class="hlt">age</span> of 5.2 Ma for the Shilou profile. Based on the new <span class="hlt">age</span> <span class="hlt">model</span>, wavelet analysis reveals the well-preserved 400 kyr and possible 100 kyr eccentricity cycles on the eastern Chinese Loess Plateau. Further, paleomonsoon evolution during 2.58-5.2 Ma is reconstructed and divided into three intervals (2.58-3.6 Ma, 3.6-4.5 Ma, and 4.5-5.2 Ma). The upper part, the youngest stage, is characterized by a relatively intensified summer monsoon, the middle stage reflects an intensification of the winter monsoon and aridification in Asia, and the earliest stage indicates that summer and winter monsoon cycles may have rapidly altered. The use of cyclostratigraphy along with magnetostratigraphy gives us an effective method of dating red clay sequences, and our results imply that many presently published <span class="hlt">age</span> <span class="hlt">models</span> for the red clay deposits should be perhaps re-evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004IJMPC..15..569S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004IJMPC..15..569S"><span id="translatedtitle">Advertising, Consensus, and <span class="hlt">Aging</span> in Multilayer Sznajd <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schulze, Christian</p> <p></p> <p>In the Sznajd consensus <span class="hlt">model</span> on the square lattice, two people who agree in their opinions convince their neighbors of this opinion. We generalize it to many layers representing many <span class="hlt">age</span> levels, and check if a consensus among all layers is possible. Advertising sometimes, but not always, produces a consensus on the advertised opinion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6665028','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6665028"><span id="translatedtitle"><span class="hlt">Modeling</span> sugarcane growth in response to <span class="hlt">age</span>, insolation, and temperature</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>How, K.T.S.</p> <p>1986-01-01</p> <p><span class="hlt">Modeling</span> sugarcane growth in response to <span class="hlt">age</span> of cane, insolation and air temperature using first-order multiple regression analysis and a nonlinear approach is investigated. Data are restricted to one variety from irrigated fields to eliminate the impact of varietal response and rainfall. Ten first-order <span class="hlt">models</span> are investigated. The predictant is cane yield from 600 field tests. The predictors are cumulative values of insolation, maximum temperature, and minimum temperature for 3, 6, 12, and 18 months, or for each crop period derived from weather observations near the test plots. The low R-square values indicate that the selected predictor variables could not account for a substantial proportion of the variations of cane yield and the <span class="hlt">models</span> have limited predictive values. The nonlinear <span class="hlt">model</span> is based on known functional relationships between growth and <span class="hlt">age</span>, growth and insolation, and growth and maximum temperature. A mathematical expression that integrates the effect of <span class="hlt">age</span>, insolation and maximum temperature is developed. The constant terms and coefficients of the equation are determined from the requirement that the <span class="hlt">model</span> must produce results that are reasonable when compared with observed monthly elongation data. The nonlinear <span class="hlt">model</span> is validated and tested using another set of data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7174E..0LH','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7174E..0LH"><span id="translatedtitle"><span class="hlt">Absolute</span> near-infrared oximetry for urology: a quantitative study of the tissue hemoglobin saturation before and after testicular torsion in a rabbit <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hallacoglu, Bertan; Matulewicz, Richard S.; Paltiel, Harriet J.; Padua, Horacio; Gargollo, Patricio; Cannon, Glenn; Alomari, Ahmad; Sassaroli, Angelo; Fantini, Sergio</p> <p>2009-02-01</p> <p>We present an experimental study on four rabbits to demonstrate the feasibility of near-infrared spectroscopy in the noninvasive assessment of testicular torsion. We used a multi-distance frequency-domain method, based on a fixed detector position and a 9-mm linear scan of the illumination optical fibers, to measure <span class="hlt">absolute</span> values of pre- and post-operative testicular oxygen saturation. Unilateral testicular torsions (by 0°, 540° or 720°) on experimental testes and contralateral sham surgeries (no torsion) on control testes were performed and studied. Our results showed (a) a consistent baseline <span class="hlt">absolute</span> tissue oxygen saturation value of 78% +/- 5%; (b) a comparable <span class="hlt">absolute</span> saturation of 77% +/- 6% on the control side (testes after sham surgery); and (c) a significantly lower tissue oxygen saturation of 36% +/- 2% on the experimental side (testes after 540° or 720° torsion surgery). These results demonstrate the capability of frequency domain nearinfrared spectroscopy in the assessment of <span class="hlt">absolute</span> testicular hemoglobin desaturation caused by torsion, and show promise as a potential method to serve as a complement to conventional color and spectral Doppler ultrasonography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27106402','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27106402"><span id="translatedtitle">Muscle wasting and <span class="hlt">aging</span>: Experimental <span class="hlt">models</span>, fatty infiltrations, and prevention.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brioche, Thomas; Pagano, Allan F; Py, Guillaume; Chopard, Angèle</p> <p>2016-08-01</p> <p>Identification of cost-effective interventions to maintain muscle mass, muscle strength, and physical performance during muscle wasting and <span class="hlt">aging</span> is an important public health challenge. It requires understanding of the cellular and molecular mechanisms involved. Muscle-deconditioning processes have been deciphered by means of several experimental <span class="hlt">models</span>, bringing together the opportunities to devise comprehensive analysis of muscle wasting. Studies have increasingly recognized the importance of fatty infiltrations or intermuscular adipose tissue for the <span class="hlt">age</span>-mediated loss of skeletal-muscle function and emphasized that this new important factor is closely linked to inactivity. The present review aims to address three main points. We first mainly focus on available experimental <span class="hlt">models</span> involving cell, animal, or human experiments on muscle wasting. We next point out the role of intermuscular adipose tissue in muscle wasting and <span class="hlt">aging</span> and try to highlight new findings concerning <span class="hlt">aging</span> and muscle-resident mesenchymal stem cells called fibro/adipogenic progenitors by linking some cellular players implicated in both FAP fate modulation and advancing <span class="hlt">age</span>. In the last part, we review the main data on the efficiency and molecular and cellular mechanisms by which exercise, replacement hormone therapies, and β-hydroxy-β-methylbutyrate prevent muscle wasting and sarcopenia. Finally, we will discuss a potential therapeutic target of sarcopenia: glucose 6-phosphate dehydrogenase. PMID:27106402</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3199952','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3199952"><span id="translatedtitle">Mindspan: Lessons from Rat <span class="hlt">Models</span> of Neurocognitive <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gallagher, Michela; Stocker, Amy; Koh, Ming Teng</p> <p>2011-01-01</p> <p>Research on the biology of <span class="hlt">aging</span> seeks to enhance understanding of basic mechanisms and thus support improvements in outcomes throughout the lifespan, including longevity itself, susceptibility to disease, and life-long adaptive capacities. The focus of this review is the use of rats as an animal <span class="hlt">model</span> of cognitive change during <span class="hlt">aging</span>, and specifically lessons learned from <span class="hlt">aging</span> rats in behavioral studies of cognitive processes mediated by specialized neural circuitry. An advantage of this approach is the ability to compare brain <span class="hlt">aging</span> across species where functional homology exists for specific neural systems; in this article we focus on behavioral assessments that target the functions of the medial temporal lobe and prefrontal cortex. We also take a critical look at studies using calorie restriction (CR) as a well-defined experimental approach to manipulating biological <span class="hlt">aging</span>. We conclude that the effects of CR on cognitive <span class="hlt">aging</span> in rats are less well established than commonly assumed, with much less supportive evidence relative to its benefits on longevity and susceptibility to disease, and that more research in this area is necessary. PMID:21411856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014CliPD..10.4499W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014CliPD..10.4499W"><span id="translatedtitle">Technical Note: Probabilistically constraining proxy <span class="hlt">age</span>-depth <span class="hlt">models</span> within a Bayesian hierarchical reconstruction <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Werner, J. P.; Tingley, M. P.</p> <p>2014-12-01</p> <p>Reconstructions of late-Holocene climate rely heavily upon proxies that are assumed to be accurately dated by layer counting, such as measurement on tree rings, ice cores, and varved lake sediments. Considerable advances may be achievable if time uncertain proxies could be included within these multiproxy reconstructions, and if time uncertainties were recognized and correctly <span class="hlt">modeled</span> for proxies commonly treated as free of <span class="hlt">age</span> <span class="hlt">model</span> errors. Current approaches to accounting for time uncertainty are generally limited to repeating the reconstruction using each of an ensemble of <span class="hlt">age</span> <span class="hlt">models</span>, thereby inflating the final estimated uncertainty - in effect, each possible <span class="hlt">age</span> <span class="hlt">model</span> is given equal weighting. Uncertainties can be reduced by exploiting the inferred space-time covariance structure of the climate to re-weight the possible <span class="hlt">age</span> <span class="hlt">models</span>. Here we demonstrate how Bayesian Hierarchical climate reconstruction <span class="hlt">models</span> can be augmented to account for time uncertain proxies. Critically, while a priori all <span class="hlt">age</span> <span class="hlt">models</span> are given equal probability of being correct, the probabilities associated with the <span class="hlt">age</span> <span class="hlt">models</span> are formally updated within the Bayesian framework, thereby reducing uncertainties. Numerical experiments show that updating the <span class="hlt">age-model</span> probabilities decreases uncertainty in the climate reconstruction, as compared with the current de-facto standard of sampling over all <span class="hlt">age</span> <span class="hlt">models</span>, provided there is sufficient information from other data sources in the region of the time-uncertain proxy. This approach can readily be generalized to non-layer counted proxies, such as those derived from marine sediments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CliPa..11..533W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CliPa..11..533W"><span id="translatedtitle">Technical Note: Probabilistically constraining proxy <span class="hlt">age</span>-depth <span class="hlt">models</span> within a Bayesian hierarchical reconstruction <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Werner, J. P.; Tingley, M. P.</p> <p>2015-03-01</p> <p>Reconstructions of the late-Holocene climate rely heavily upon proxies that are assumed to be accurately dated by layer counting, such as measurements of tree rings, ice cores, and varved lake sediments. Considerable advances could be achieved if time-uncertain proxies were able to be included within these multiproxy reconstructions, and if time uncertainties were recognized and correctly <span class="hlt">modeled</span> for proxies commonly treated as free of <span class="hlt">age</span> <span class="hlt">model</span> errors. Current approaches for accounting for time uncertainty are generally limited to repeating the reconstruction using each one of an ensemble of <span class="hlt">age</span> <span class="hlt">models</span>, thereby inflating the final estimated uncertainty - in effect, each possible <span class="hlt">age</span> <span class="hlt">model</span> is given equal weighting. Uncertainties can be reduced by exploiting the inferred space-time covariance structure of the climate to re-weight the possible <span class="hlt">age</span> <span class="hlt">models</span>. Here, we demonstrate how Bayesian hierarchical climate reconstruction <span class="hlt">models</span> can be augmented to account for time-uncertain proxies. Critically, although a priori all <span class="hlt">age</span> <span class="hlt">models</span> are given equal probability of being correct, the probabilities associated with the <span class="hlt">age</span> <span class="hlt">models</span> are formally updated within the Bayesian framework, thereby reducing uncertainties. Numerical experiments show that updating the <span class="hlt">age</span> <span class="hlt">model</span> probabilities decreases uncertainty in the resulting reconstructions, as compared with the current de facto standard of sampling over all <span class="hlt">age</span> <span class="hlt">models</span>, provided there is sufficient information from other data sources in the spatial region of the time-uncertain proxy. This approach can readily be generalized to non-layer-counted proxies, such as those derived from marine sediments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9212W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9212W"><span id="translatedtitle">Probabilistically constraining proxy <span class="hlt">age</span>-depth <span class="hlt">models</span> within a Bayesian hierarchical reconstruction <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Werner, Johannes; Tingley, Martin</p> <p>2015-04-01</p> <p>Reconstructions of late-Holocene climate rely heavily upon proxies that are assumed to be accurately dated by layer counting, such as measurement on tree rings, ice cores, and varved lake sediments. Considerable advances may be achievable if time uncertain proxies could be included within these multiproxy reconstructions, and if time uncertainties were recognized and correctly <span class="hlt">modeled</span> for proxies commonly treated as free of <span class="hlt">age</span> <span class="hlt">model</span> errors. Current approaches to accounting for time uncertainty are generally limited to repeating the reconstruction using each of an ensemble of <span class="hlt">age</span> <span class="hlt">models</span>, thereby inflating the final estimated uncertainty - in effect, each possible <span class="hlt">age</span> <span class="hlt">model</span> is given equal weighting. Uncertainties can be reduced by exploiting the inferred space-time covariance structure of the climate to re-weight the possible <span class="hlt">age</span> <span class="hlt">models</span>. Here we demonstrate how Bayesian Hierarchical climate reconstruction <span class="hlt">models</span> can be augmented to account for time uncertain proxies. Critically, while a priori all <span class="hlt">age</span> <span class="hlt">models</span> are given equal probability of being correct, the probabilities associated with the <span class="hlt">age</span> <span class="hlt">models</span> are formally updated within the Bayesian framework, thereby reducing uncertainties. Numerical experiments show that updating the <span class="hlt">age</span> <span class="hlt">model</span> probabilities decreases uncertainty in the climate reconstruction, as compared with the current de-facto standard of sampling over all <span class="hlt">age</span> <span class="hlt">models</span>, provided there is sufficient information from other data sources in the region of the time-uncertain proxy. This approach can readily be generalized to non-layer counted proxies, such as those derived from marine sediments. Werner and Tingley, Climate of the Past Discussions (2014)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4004354','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4004354"><span id="translatedtitle">Rotifers as <span class="hlt">models</span> for the biology of <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Snell, Terry W.</p> <p>2013-01-01</p> <p>It has been two decades since 1993 when research on the biology of rotifer <span class="hlt">aging</span> was last reviewed by Enesco. Much has transpired during this time as rotifer biologists have adapted to the “omics” revolution and incorporated these techniques into the experimental analysis of rotifers. Rotifers are amenable to many of these approaches and getting adequate quantities of DNA, RNA, and protein from rotifers is not difficult. Analysis of rotifer genomes, transcriptomes, and proteomes is rapidly yielding candidate genes that likely regulate a variety of features of rotifer biology. Parallel developments in <span class="hlt">aging</span> biology have recognized the limitations of standard animal <span class="hlt">models</span> like worms and flies and that comparative <span class="hlt">aging</span> research has essentially ignored a large fraction of animal phylogeny in the lophotrochozoans. As experimentally tractable members of this group, rotifers have attracted interest as <span class="hlt">models</span> of <span class="hlt">aging</span>. In this paper, I review advances over the past 20 years in the biology of <span class="hlt">aging</span> in rotifers, with emphasis on the unique contributions of rotifer <span class="hlt">models</span> for understanding <span class="hlt">aging</span>. The majority of experimental work has manipulated rotifer diet and followed changes in survival and reproductive dynamics like mean lifespan, maximum lifespan, reproductive lifespan, and mortality rate doubling time. The main dietary manipulation has been some form of caloric restriction, withholding food for some period or feeding continuously at low levels. There have been comparative studies of several rotifer species, with some species responding to caloric restriction with life extension, but others not, at least under the tested food regimens. Other aspects of diet are less explored, like nutritional properties of different algae species and their capacity to extend rotifer lifespan. Several descriptive studies have reported many genes involved in rotifer <span class="hlt">aging</span> by comparing gene expression in young and old individuals. Classes of genes up or down-regulated during <span class="hlt">aging</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&id=EJ765743','ERIC'); return false;" href="http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&id=EJ765743"><span id="translatedtitle">Be Resolute about <span class="hlt">Absolute</span> Value</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kidd, Margaret L.</p> <p>2007-01-01</p> <p>This article explores how conceptualization of <span class="hlt">absolute</span> value can start long before it is introduced. The manner in which <span class="hlt">absolute</span> value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1738.0003K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1738.0003K"><span id="translatedtitle"><span class="hlt">Modelling</span> safety of multistate systems with <span class="hlt">ageing</span> components</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna</p> <p>2016-06-01</p> <p>An innovative approach to safety analysis of multistate <span class="hlt">ageing</span> systems is presented. Basic notions of the <span class="hlt">ageing</span> multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety <span class="hlt">models</span> to the evaluation and prediction of the safty characteristics of the consecutive "m out of n: F" is presented as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000IJMPC..11.1209D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000IJMPC..11.1209D"><span id="translatedtitle">Scaling in a Continuous Time <span class="hlt">Model</span> for Biological <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Almeida, R. M. C.; Thomas, G. L.</p> <p></p> <p>In this paper, we consider a generalization to the asexual version of Penna <span class="hlt">model</span> for biological <span class="hlt">aging</span>, where we take a continuous time limit. The genotype associated to each individual is an interval of real numbers over which Dirac δ-functions are defined, representing genetically programmed diseases to be switched on at defined <span class="hlt">ages</span> of the individual life. We discuss two different continuous limits for the evolution equation and two different mutation protocols, to be implemented during reproduction. Exact stationary solutions are obtained and scaling properties are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006PhyA..368..147G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006PhyA..368..147G&link_type=ABSTRACT"><span id="translatedtitle">Computer simulation of Aphis gossypii insects using Penna <span class="hlt">aging</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giarola, L. T. P.; Martins, S. G. F.; Toledo Costa, M. C. P.</p> <p>2006-08-01</p> <p>A computer simulation was made for the population dynamics of Aphis gossypii in laboratory and field conditions. The <span class="hlt">age</span> structure was inserted in the dynamics through bit string <span class="hlt">model</span> for biological <span class="hlt">aging</span>, proposed by Penna in 1995. The influence of different host plants and of climatic factors such as temperature and precipitation was considered in the simulation starting from experimental data. The results obtained indicate that the simulation is an appropriate instrument for understanding of the population dynamics of these species and for the establishment of biological control strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25768548','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25768548"><span id="translatedtitle">Anomalous scaling in an <span class="hlt">age</span>-dependent branching <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Keller-Schmidt, Stephanie; Tuğrul, Murat; Eguíluz, Víctor M; Hernández-García, Emilio; Klemm, Konstantin</p> <p>2015-02-01</p> <p>We introduce a one-parametric family of tree growth <span class="hlt">models</span>, in which branching probabilities decrease with branch <span class="hlt">age</span> τ as τ(-α). Depending on the exponent α, the scaling of tree depth with tree size n displays a transition between the logarithmic scaling of random trees and an algebraic growth. At the transition (α=1) tree depth grows as (logn)(2). This anomalous scaling is in good agreement with the trend observed in evolution of biological species, thus providing a theoretical support for <span class="hlt">age</span>-dependent speciation and associating it to the occurrence of a critical point. PMID:25768548</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..91b2803K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..91b2803K"><span id="translatedtitle">Anomalous scaling in an <span class="hlt">age</span>-dependent branching <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keller-Schmidt, Stephanie; Tuǧrul, Murat; Eguíluz, Víctor M.; Hernández-García, Emilio; Klemm, Konstantin</p> <p>2015-02-01</p> <p>We introduce a one-parametric family of tree growth <span class="hlt">models</span>, in which branching probabilities decrease with branch <span class="hlt">age</span> τ as τ-α. Depending on the exponent α , the scaling of tree depth with tree size n displays a transition between the logarithmic scaling of random trees and an algebraic growth. At the transition (α =1 ) tree depth grows as (logn) 2. This anomalous scaling is in good agreement with the trend observed in evolution of biological species, thus providing a theoretical support for <span class="hlt">age</span>-dependent speciation and associating it to the occurrence of a critical point.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3733585','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3733585"><span id="translatedtitle"><span class="hlt">Aging</span>, Neurogenesis, and Caloric Restriction in Different <span class="hlt">Model</span> Organisms</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Arslan-Ergul, Ayca; Ozdemir, A Tugrul; Adams, Michelle M</p> <p>2013-01-01</p> <p>Brain <span class="hlt">aging</span> is a multifactorial process that is occurring across multiple cognitive domains. A significant complaint that occurs in the elderly is a decrement in learning and memory ability. Both rodents and zebrafish exhibit a similar problem with memory during <span class="hlt">aging</span>. The neurobiological changes that underlie this cognitive decline are complex and undoubtedly influenced by many factors. Alterations in the birth of new neurons and neuron turnover may contribute to <span class="hlt">age</span>-related cognitive problems. Caloric restriction is the only non-genetic intervention that reliably increases life span and healthspan across multiple organisms although the molecular mechanisms are not well-understood. Recently the zebrafish has become a popular <span class="hlt">model</span> organism for understanding the neurobiological consequences but to date very little work has been performed. Similarly, few studies have examined the effects of dietary restriction in zebrafish. Here we review the literature related to memory decline, neurogenesis, and caloric restriction across <span class="hlt">model</span> organisms and suggest that zebrafish has the potential to be an important animal <span class="hlt">model</span> for understanding the complex interactions between <span class="hlt">age</span>, neurobiological changes in the brain, and dietary regimens or their mimetics as interventions. PMID:23936746</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22034370','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22034370"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> PROPERTIES OF THE ECLIPSING BINARY STAR V335 SERPENTIS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lacy, Claud H. Sandberg; Fekel, Francis C.; Claret, Antonio E-mail: fekel@evans.tsuniv.edu</p> <p>2012-08-15</p> <p>V335 Ser is now known to be an eccentric double-lined A1+A3 binary star with fairly deep (0.5 mag) partial eclipses. Previous studies of the system are improved with 7456 differential photometric observations from the URSA WebScope and 5666 from the NFO WebScope, and 67 high-resolution spectroscopic observations from the Tennessee State University 2 m automatic spectroscopic telescope. From dates of minima, the apsidal period is about 880 years. Accurate (better than 2%) masses and radii are determined from analysis of the two new light curves and the radial velocity curve. Theoretical <span class="hlt">models</span> match the <span class="hlt">absolute</span> properties of the stars at an <span class="hlt">age</span> of about 380 Myr, though the <span class="hlt">age</span> agreement for the two components is poor. Tidal theory correctly confirms that the orbit should still be eccentric, but we find that standard tidal theory is unable to match the observed asynchronous rotation rates of the components' surface layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3809914','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3809914"><span id="translatedtitle">Impact of <span class="hlt">aging</span> mechanism on <span class="hlt">model</span> simulated carbonaceous aerosols</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Huang, Y.; Wu, S.; Dubey, M.K.; French, N. H. F.</p> <p>2013-01-01</p> <p>Carbonaceous aerosols including organic carbon and black carbon have significant implications for both climate and air quality. In the current global climate or chemical transport <span class="hlt">models</span>, a fixed hydrophobic-to-hydrophilic conversion lifetime for carbonaceous aerosol (τ) is generally assumed, which is usually around one day. We have implemented a new detailed <span class="hlt">aging</span> scheme for carbonaceous aerosols in a chemical transport <span class="hlt">model</span> (GEOS-Chem) to account for both the chemical oxidation and the physical condensation-coagulation effects, where τ is affected by local atmospheric environment including atmospheric concentrations of water vapor, ozone, hydroxyl radical and sulfuric acid. The updated τ exhibits large spatial and temporal variations with the global average (up to 11 km altitude) calculated to be 2.6 days. The chemical <span class="hlt">aging</span> effects are found to be strongest over the tropical regions driven by the low ozone concentrations and high humidity there. The τ resulted from chemical <span class="hlt">aging</span> generally decreases with altitude due to increases in ozone concentration and decreases in humidity. The condensation-coagulation effects are found to be most important for the high-latitude areas, in particular the polar regions, where the τ values are calculated to be up to 15 days. When both the chemical <span class="hlt">aging</span> and condensation-coagulation effects are considered, the total atmospheric burdens and global average lifetimes of BC, black carbon, (OC, organic carbon) are calculated to increase by 9% (3%) compared to the control simulation, with considerable enhancements of BC and OC concentrations in the Southern Hemisphere. <span class="hlt">Model</span> evaluations against data from multiple datasets show that the updated <span class="hlt">aging</span> scheme improves <span class="hlt">model</span> simulations of carbonaceous aerosols for some regions, especially for the remote areas in the Northern Hemisphere. The improvement helps explain the persistent low <span class="hlt">model</span> bias for carbonaceous aerosols in the Northern Hemisphere reported in literature. Further</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.2436H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.2436H&link_type=ABSTRACT"><span id="translatedtitle">Geophysical <span class="hlt">Age</span> Dating of Seamounts using Dense Core Flexure <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hwang, Gyuha; Kim, Seung-Sep</p> <p>2016-04-01</p> <p>Lithospheric flexure of oceanic plate is thermo-mechanical response of an elastic plate to the given volcanic construct (e.g., seamounts and ocean islands). If the shape and mass of such volcanic loads are known, the flexural response is governed by the thickness of elastic plate, Te. As the <span class="hlt">age</span> of oceanic plate increases, the elastic thickness of oceanic lithosphere becomes thicker. Thus, we can relate Te with the <span class="hlt">age</span> of plate at the time of loading. To estimate the amount of the driving force due to seamounts on elastic plate, one needs to approximate their density structure. The most common choice is uniform density <span class="hlt">model</span>, which utilizes constant density value for a seamount. This approach simplifies computational processes for gravity prediction and error estimates. However, the uniform density <span class="hlt">model</span> tends to overestimate the total mass of the seamount and hence produces more positive gravitational contributions from the load. Minimization of gravity misfits using uniform density, therefore, favors thinner Te in order to increase negative contributions from the lithospheric flexure, which can compensate for the excessive positives from the seamount. An alternative approach is dense core <span class="hlt">model</span>, which approximate the heterogeneity nature of seamount density as three bodies of infill sediment, edifice, and dense core. In this study, we apply the dense core <span class="hlt">model</span> to the Louisville Seamount Chain for constraining flexural deformation. We compare Te estimates with the loading time of the examined seamounts to redefine empirical geophysical <span class="hlt">age</span> dating of seamounts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1227359','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1227359"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay using count distribution (LAMBDA) space</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2015-12-01</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a <span class="hlt">model</span> to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1055713','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1055713"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay using count distribution (LAMBDA) space</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2012-06-05</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a <span class="hlt">model</span> to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27174949','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27174949"><span id="translatedtitle">Mechanical Regulation of Cardiac <span class="hlt">Aging</span> in <span class="hlt">Model</span> Systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sessions, Ayla O; Engler, Adam J</p> <p>2016-05-13</p> <p>Unlike diet and exercise, which individuals can modulate according to their lifestyle, <span class="hlt">aging</span> is unavoidable. With normal or healthy <span class="hlt">aging</span>, the heart undergoes extensive vascular, cellular, and interstitial molecular changes that result in stiffer less compliant hearts that experience a general decline in organ function. Although these molecular changes deemed cardiac remodeling were once thought to be concomitant with advanced cardiovascular disease, they can be found in patients without manifestation of clinical disease. It is now mostly acknowledged that these <span class="hlt">age</span>-related mechanical changes confer vulnerability of the heart to cardiovascular stresses associated with disease, such as hypertension and atherosclerosis. However, recent studies have aimed at differentiating the initial compensatory changes that occur within the heart with <span class="hlt">age</span> to maintain contractile function from the maladaptive responses associated with disease. This work has identified new targets to improve cardiac function during <span class="hlt">aging</span>. Spanning invertebrate to vertebrate <span class="hlt">models</span>, we use this review to delineate some hallmarks of physiological versus pathological remodeling that occur in the cardiomyocyte and its microenvironment, focusing especially on the mechanical changes that occur within the sarcomere, intercalated disc, costamere, and extracellular matrix. PMID:27174949</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.445.1213S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.445.1213S"><span id="translatedtitle">Spectral <span class="hlt">age</span> <span class="hlt">modelling</span> of the `Sausage' cluster radio relic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stroe, Andra; Harwood, Jeremy J.; Hardcastle, Martin J.; Röttgering, Huub J. A.</p> <p>2014-12-01</p> <p>CIZA J2242.8+5301 is a post-core passage, binary merging cluster that hosts a large, thin, arc-like radio relic, nicknamed the `Sausage', tracing a relatively strong shock front. We perform spatially resolved spectral fitting to the available radio data for this radio relic, using a variety of spectral <span class="hlt">ageing</span> <span class="hlt">models</span>, with the aim of finding a consistent set of parameters for the shock and radio plasma. We determine an injection index of 0.77^{+0.03}_{-0.02} for the relic plasma, significantly steeper than was found before. Standard particle acceleration at the shock front implies a Mach number M=2.90^{+0.10}_{-0.13}, which now matches X-ray measurements. The shock advance speed is vshock ≈ 2500 km s-1, which places the core passage of the two subclusters 0.6-0.8 Gyr ago. We find a systematic spectral <span class="hlt">age</span> increase from 0 at the northern side of the relic up to ˜60 Myr at ˜145 kpc into the downstream area, assuming a 0.6 nT magnetic field. Under the assumption of freely <span class="hlt">ageing</span> electrons after acceleration by the `Sausage' shock, the spectral <span class="hlt">ages</span> are hard to reconcile with the shock speed derived from X-ray and radio observations. Re-acceleration or unusually efficient transport of particle in the downstream area and line-of-sight mixing could help explain the systematically low spectral <span class="hlt">ages</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24846014','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24846014"><span id="translatedtitle">Predicting mortality from burns: the need for <span class="hlt">age</span>-group specific <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Taylor, Sandra L; Lawless, MaryBeth; Curri, Terese; Sen, Soman; Greenhalgh, David G; Palmieri, Tina L</p> <p>2014-09-01</p> <p>Traditional burn mortality <span class="hlt">models</span> are derived using all <span class="hlt">age</span> groups. We hypothesized that <span class="hlt">age</span> variably impacts mortality after burn and that <span class="hlt">age</span>-specific <span class="hlt">models</span> for children, adults, and seniors will more accurately predict mortality than an all-<span class="hlt">ages</span> <span class="hlt">model</span>. We audited data from the American Burn Association (ABA) National Burn Repository (NBR) from 2000 to 2009 and used mixed effect logistic regression <span class="hlt">models</span> to assess the influence of <span class="hlt">age</span>, total body surface area (TBSA) burn, and inhalation injury on mortality. Mortality <span class="hlt">models</span> were constructed for all <span class="hlt">ages</span> and <span class="hlt">age</span>-specific <span class="hlt">models</span>: children (<18 years), adults (18-60 years), and seniors (>60 years). <span class="hlt">Model</span> performance was assessed by area under the receiver operating curve (AUC). Main effect and two-way interactions were used to construct <span class="hlt">age</span>-group specific mortality <span class="hlt">models</span>. Each <span class="hlt">age</span>-specific <span class="hlt">model</span> was compared to the All <span class="hlt">Ages</span> <span class="hlt">model</span>. Of 286,293 records 100,051 had complete data. Overall mortality was 4% but varied by <span class="hlt">age</span> (17% seniors, <1% children). <span class="hlt">Age</span>, TBSA, and inhalation injury were significant mortality predictors for all <span class="hlt">models</span> (p<0.05). Differences in predicted mortality between the All <span class="hlt">Ages</span> <span class="hlt">model</span> and the <span class="hlt">age</span>-specific <span class="hlt">models</span> occurred in children and seniors. In the <span class="hlt">age</span>-specific pediatric <span class="hlt">model</span>, predicted mortality decreased with <span class="hlt">age</span>; inhalation injury had greater effect on mortality than in the All <span class="hlt">Ages</span> <span class="hlt">model</span>. In the senior <span class="hlt">model</span> mortality increased with <span class="hlt">age</span>. Seniors had greater increase in mortality per 1% increment in burn size and 1 year increase in <span class="hlt">age</span> than other <span class="hlt">ages</span>. The predicted mortality in seniors using the senior-specific <span class="hlt">model</span> was higher than in the All <span class="hlt">Ages</span> <span class="hlt">model</span>. "One size fits all" <span class="hlt">models</span> for predicting burn outcomes do not accurately reflect the outcomes for seniors and children. <span class="hlt">Age</span>-specific <span class="hlt">models</span> for children and seniors may be advisable. PMID:24846014</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24316042','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24316042"><span id="translatedtitle">Zebrafish (Danio rerio) as a <span class="hlt">model</span> for the study of <span class="hlt">aging</span> and exercise: physical ability and trainability decrease with <span class="hlt">age</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gilbert, Matthew J H; Zerulla, Tanja C; Tierney, Keith B</p> <p>2014-02-01</p> <p>A rapidly <span class="hlt">aging</span> global population has motivated the development and use of <span class="hlt">models</span> for human <span class="hlt">aging</span>. Studies on <span class="hlt">aging</span> have shown parallels between zebrafish and humans at the internal organization level; however, few parallels have been studied at the whole-organism level. Furthermore, the effectiveness of exercise as a method to mitigate the effects of <span class="hlt">aging</span> has not been studied in zebrafish. We investigated the effects of <span class="hlt">aging</span> and intermittent exercise on swimming performance, kinematics and behavior. Young, middle-<span class="hlt">aged</span> and old zebrafish (20-29, 36-48 and 60-71% of average lifespan, respectively) were exercised to exhaustion in endurance and sprint swimming tests once a week for four weeks. Both endurance and sprint performance decreased with increased <span class="hlt">age</span>. Swimming performance improved with exercise training in young and middle-<span class="hlt">aged</span> zebrafish, but not in old zebrafish. Tail-beat amplitude, which is akin to stride length in humans, increased for all <span class="hlt">age</span> groups with training. Zebrafish turning frequency, which is an indicator of routine activity, decreased with <span class="hlt">age</span> but showed no change with exercise. In sum, our results show that zebrafish exhibit a decline in whole-organism performance and trainability with <span class="hlt">age</span>. These findings closely resemble the senescence-related declines in physical ability experienced by humans and mammalian <span class="hlt">aging</span> <span class="hlt">models</span> and therefore support the use of zebrafish as a <span class="hlt">model</span> for human exercise and <span class="hlt">aging</span>. PMID:24316042</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JNET...41...79S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JNET...41...79S"><span id="translatedtitle"><span class="hlt">Modeling</span> <span class="hlt">Aging</span> and Mechanical Rejuvenation of Amorphous Solids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Semkiv, Mykhailo; Hütter, Markus</p> <p>2016-04-01</p> <p>The elasto-viscoplasticity of amorphous solids is <span class="hlt">modeled</span>, with a focus on the effects of physical <span class="hlt">aging</span> and mechanical rejuvenation. Using nonequilibrium thermodynamics, the concept of kinetic and configurational subsystems has been employed. The Hamiltonian structure of reversible dynamics is exploited to derive a constitutive relation for the stress tensor. Furthermore, it is demonstrated that accounting for mechanical rejuvenation results in a modification of the driving force for viscoplastic flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014CMT....26..247D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014CMT....26..247D"><span id="translatedtitle"><span class="hlt">Ageing</span> of polymer bonds: a coupled chemomechanical <span class="hlt">modelling</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dippel, Benedikt; Johlitz, Michael; Lion, Alexander</p> <p>2014-05-01</p> <p>With the increasing number of requirements on joinings, it gets more and more important to understand and predict an assemblies properties. Nowadays, in industrial applications, combinations of different materials get more common. In most of those cases, it is, besides other advantages, useful to connect such parts with adhesives to avoid local cells. Thus, the knowledge about the mechanical behaviour of adhesives over the whole time of utilisation is an essential element of engineering. As it is well known, <span class="hlt">ageing</span> due to environmental influences such as oxygen, radiation, ozone and others plays a major role in polymers properties. So, for the prediction of applicability over the whole lifetime of a technical component, the change in mechanical properties due to <span class="hlt">ageing</span> is necessary. In this contribution, we introduce a material <span class="hlt">model</span> which takes into account the internal structure of an adhesive. Therefore, an interphase zone is introduced. In the interphase, which is developed due to the contact of an adhesive with an adherent, the materials properties change continuously from the surface to the centre of the joint, where the polymer is in a bulky state. Built up on this geometry dependency, the materials <span class="hlt">ageing</span> as a function of the position is described. To <span class="hlt">model</span> the change of the polymers state, we use a parameter representing chain scission processes and another one for the reformation of a new network. In a last step, the <span class="hlt">model</span> is transferred into a finite element code for exemplary calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7101393','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7101393"><span id="translatedtitle">[Geriatrics: an <span class="hlt">absolute</span> necessity].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oostvogel, F J</p> <p>1982-02-01</p> <p>The medical care for elderly people could be greatly improved. If no specific attention is paid immediately, namely through the various training courses and by way of further and part-time schooling, then this medical care will remain unsatisfactory. This situation worsens continually due to the growing number of elderly people and, within this group, a much higher rate of very <span class="hlt">aged</span> people. Increasing the care in institutions is altogether unsatisfactory. The problem should be dealt with structurally and the emphasis placed upon prevention and early-diagnosis. There is an urgent need for an integrated method, keeping in mind the limits of the elderly person, from the physical, psychological and social aspects. This demands teamwork in a multidisciplinary system inside as well as outside the institutions. It demands a thorough knowledge of geriatrics based upon gerontology. Geriatricians are urgently needed in this development together with doctors in nursing homes, general practitioners and specialists, so that the necessary care may be established as quickly as possible. PMID:7101393</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24653904','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24653904"><span id="translatedtitle"><span class="hlt">Aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Dong Choon; Yeo, Seung Geun</p> <p>2013-09-01</p> <p><span class="hlt">Aging</span> is initiated based on genetic and environmental factors that operate from the time of birth of organisms. <span class="hlt">Aging</span> induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological <span class="hlt">aging</span>. Despite the efforts from many researchers, the progression and the mechanisms of <span class="hlt">aging</span> are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent <span class="hlt">aging</span> and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3936540','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3936540"><span id="translatedtitle"><span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Park, Dong Choon</p> <p>2013-01-01</p> <p><span class="hlt">Aging</span> is initiated based on genetic and environmental factors that operate from the time of birth of organisms. <span class="hlt">Aging</span> induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological <span class="hlt">aging</span>. Despite the efforts from many researchers, the progression and the mechanisms of <span class="hlt">aging</span> are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent <span class="hlt">aging</span> and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AIPC.1587...95S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AIPC.1587...95S&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Age</span> structured dynamical <span class="hlt">model</span> for an endangered lizard Eulamprus leuraensis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Supriatna, A. K.; Rachmadani, Q.; Ilahi, F.; Anggriani, N.; Nuraini, N.</p> <p>2014-02-01</p> <p>The Blue Mountains Water Skink, Eulamprus leuraensis, is listed as an endangered species under the IUCN Red List. This lizard species has a typical characteristic of growth with a low fecundity. It is known that the offspring quality may decline with maternal <span class="hlt">age</span> of the parents despite they can grow rapidly from neonatal size to adult size within two to three years. It is also believed that low adult survival rates and specialization on rare and fragmented type of habitat are the main cause leading to the endangered status of the lizard. A mathematical <span class="hlt">model</span> with <span class="hlt">age</span> structure for Eulamprus leuraensis, taking into account the variation of survival rate in each structure and the declining of offspring quality with respect to maternal <span class="hlt">age</span> is considered here. Stable coexistence of non-trivial equilibriumis shown. It is also shown that an endangered status is due to combination oflow reproductive output and low rates of adult survival. Further, understanding the <span class="hlt">age</span> structure within populations can facilitate efective management of the endangered species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22089793','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22089793"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> PROPERTIES OF THE TRIPLE STAR CF TAURI</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lacy, Claud H. Sandberg; Torres, Guillermo; Claret, Antonio E-mail: gtorres@cfa.harvard.edu</p> <p>2012-12-01</p> <p>CF Tau is now known to be an eclipsing triple star with relatively deep total and annular eclipses. New light and radial velocity curves as well as new times of minima were obtained and used for further <span class="hlt">modeling</span> of the system. Very accurate (better than 0.9%) masses and radii of the eclipsing pair are determined from analysis of the two new light curves, the radial velocity curve, and the times of minimum light. The mass and luminosity of the distant third component is accurately determined as well. Theoretical <span class="hlt">models</span> of the detached, evolved eclipsing pair match the observed <span class="hlt">absolute</span> properties of the stars at an <span class="hlt">age</span> of about 4.3 Gyr and [Fe/H] = -0.14.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4181310','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4181310"><span id="translatedtitle">Re-Evaluating Neonatal-<span class="hlt">Age</span> <span class="hlt">Models</span> for Ungulates: Does <span class="hlt">Model</span> Choice Affect Survival Estimates?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Grovenburg, Troy W.; Monteith, Kevin L.; Jacques, Christopher N.; Klaver, Robert W.; DePerno, Christopher S.; Brinkman, Todd J.; Monteith, Kyle B.; Gilbert, Sophie L.; Smith, Joshua B.; Bleich, Vernon C.; Swanson, Christopher C.; Jenks, Jonathan A.</p> <p>2014-01-01</p> <p>New-hoof growth is regarded as the most reliable metric for predicting <span class="hlt">age</span> of newborn ungulates, but variation in estimated <span class="hlt">age</span> among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry <span class="hlt">models</span>. We used known-<span class="hlt">age</span> newborns to evaluate variation in <span class="hlt">age</span> estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001–2009, we captured and radiocollared 174 newborn (≤24-hrs old) ungulates: 76 white-tailed deer (Odocoileus virginianus) in Minnesota and South Dakota, 61 mule deer (O. hemionus) in California, and 37 pronghorn (Antilocapra americana) in South Dakota. Estimated <span class="hlt">age</span> of known-<span class="hlt">age</span> newborns differed among hoof-growth <span class="hlt">models</span> and varied by >15 days for white-tailed deer, >20 days for mule deer, and >10 days for pronghorn. Accuracy (i.e., the proportion of neonates assigned to the correct <span class="hlt">age</span>) in <span class="hlt">aging</span> newborns using published equations ranged from 0.0% to 39.4% in white-tailed deer, 0.0% to 3.3% in mule deer, and was 0.0% for pronghorns. Results of survival <span class="hlt">modeling</span> indicated that variability in estimates of <span class="hlt">age</span>-at-capture affected short-term estimates of survival (i.e., 30 days) for white-tailed deer and mule deer, and survival estimates over a longer time frame (i.e., 120 days) for mule deer. Conversely, survival estimates for pronghorn were not affected by estimates of <span class="hlt">age</span>. Our analyses indicate that <span class="hlt">modeling</span> survival in daily intervals is too fine a temporal scale when <span class="hlt">age</span>-at-capture is unknown given the potential inaccuracies among equations used to estimate <span class="hlt">age</span> of neonates. Instead, weekly survival intervals are more appropriate because most <span class="hlt">models</span> accurately predicted <span class="hlt">ages</span> within 1 week of the known <span class="hlt">age</span>. Variation among results of neonatal-<span class="hlt">age</span> <span class="hlt">models</span> on short- and long-term estimates of survival for known-<span class="hlt">age</span> young emphasizes the importance of selecting an appropriate hoof-growth equation and appropriately defining intervals (i.e., weekly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70173639','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70173639"><span id="translatedtitle">Re-evaluating neonatal-<span class="hlt">age</span> <span class="hlt">models</span> for ungulates: Does <span class="hlt">model</span> choice affect survival estimates?</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Grovenburg, Troy W.; Monteith, Kevin L.; Jacques, Christopher N.; Klaver, Robert W.; DePerno, Christopher S.; Brinkman, Todd J.; Monteith, Kyle B.; Gilbert, Sophie L.; Smith, Joshua B.; Bleich, Vernon C.; Swanson, Christopher C.; Jenks, Jonathan A.</p> <p>2014-01-01</p> <p>New-hoof growth is regarded as the most reliable metric for predicting <span class="hlt">age</span> of newborn ungulates, but variation in estimated <span class="hlt">age</span> among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry <span class="hlt">models</span>. We used known-<span class="hlt">age</span> newborns to evaluate variation in <span class="hlt">age</span> estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001–2009, we captured and radiocollared 174 newborn (≤24-hrs old) ungulates: 76 white-tailed deer (Odocoileus virginianus) in Minnesota and South Dakota, 61 mule deer (O. hemionus) in California, and 37 pronghorn (Antilocapra americana) in South Dakota. Estimated <span class="hlt">age</span> of known-<span class="hlt">age</span> newborns differed among hoof-growth <span class="hlt">models</span> and varied by >15 days for white-tailed deer, >20 days for mule deer, and >10 days for pronghorn. Accuracy (i.e., the proportion of neonates assigned to the correct <span class="hlt">age</span>) in <span class="hlt">aging</span> newborns using published equations ranged from 0.0% to 39.4% in white-tailed deer, 0.0% to 3.3% in mule deer, and was 0.0% for pronghorns. Results of survival <span class="hlt">modeling</span> indicated that variability in estimates of <span class="hlt">age</span>-at-capture affected short-term estimates of survival (i.e., 30 days) for white-tailed deer and mule deer, and survival estimates over a longer time frame (i.e., 120 days) for mule deer. Conversely, survival estimates for pronghorn were not affected by estimates of <span class="hlt">age</span>. Our analyses indicate that <span class="hlt">modeling</span> survival in daily intervals is too fine a temporal scale when <span class="hlt">age</span>-at-capture is unknown given the potential inaccuracies among equations used to estimate <span class="hlt">age</span> of neonates. Instead, weekly survival intervals are more appropriate because most <span class="hlt">models</span> accurately predicted <span class="hlt">ages</span> within 1 week of the known <span class="hlt">age</span>. Variation among results of neonatal-<span class="hlt">age</span> <span class="hlt">models</span> on short- and long-term estimates of survival for known-<span class="hlt">age</span> young emphasizes the importance of selecting an appropriate hoof-growth equation and appropriately defining intervals (i.e., weekly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22037144','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22037144"><span id="translatedtitle">Mixing in <span class="hlt">age</span>-structured population <span class="hlt">models</span> of infectious diseases.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Glasser, John; Feng, Zhilan; Moylan, Andrew; Del Valle, Sara; Castillo-Chavez, Carlos</p> <p>2012-01-01</p> <p>Infectious diseases are controlled by reducing pathogen replication within or transmission between hosts. <span class="hlt">Models</span> can reliably evaluate alternative strategies for curtailing transmission, but only if interpersonal mixing is represented realistically. Compartmental <span class="hlt">modelers</span> commonly use convex combinations of contacts within and among groups of similarly <span class="hlt">aged</span> individuals, respectively termed preferential and proportionate mixing. Recently published face-to-face conversation and time-use studies suggest that parents and children and co-workers also mix preferentially. As indirect effects arise from the off-diagonal elements of mixing matrices, these observations are exceedingly important. Accordingly, we refined the formula published by Jacquez et al. [19] to account for these newly-observed patterns and estimated <span class="hlt">age</span>-specific fractions of contacts with each preferred group. As the <span class="hlt">ages</span> of contemporaries need not be identical nor those of parents and children to differ by exactly the generation time, we also estimated the variances of the Gaussian distributions with which we replaced the Kronecker delta commonly used in theoretical studies. Our formulae reproduce observed patterns and can be used, given contacts, to estimate probabilities of infection on contact, infection rates, and reproduction numbers. As examples, we illustrate these calculations for influenza based on "attack rates" from a prospective household study during the 1957 pandemic and for varicella based on cumulative incidence estimated from a cross-sectional serological survey conducted from 1988-94, together with contact rates from the several face-to-face conversation and time-use studies. Susceptibility to infection on contact generally declines with <span class="hlt">age</span>, but may be elevated among adolescents and adults with young children. PMID:22037144</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARF45011M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARF45011M"><span id="translatedtitle">Nonequilibrium equalities in <span class="hlt">absolutely</span> irreversible processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murashita, Yuto; Funo, Ken; Ueda, Masahito</p> <p>2015-03-01</p> <p>Nonequilibrium equalities have attracted considerable attention in the context of statistical mechanics and information thermodynamics. Integral nonequilibrium equalities reveal an ensemble property of the entropy production σ as <e-σ > = 1 . Although nonequilibrium equalities apply to rather general nonequilibrium situations, they break down in <span class="hlt">absolutely</span> irreversible processes, where the forward-path probability vanishes and the entropy production diverges. We identify the mathematical origins of this inapplicability as the singularity of probability measure. As a result, we generalize conventional integral nonequilibrium equalities to <span class="hlt">absolutely</span> irreversible processes as <e-σ > = 1 -λS , where λS is the probability of the singular part defined based on Lebesgue's decomposition theorem. The acquired equality contains two physical quantities related to irreversibility: σ characterizing ordinary irreversibility and λS describing <span class="hlt">absolute</span> irreversibility. An inequality derived from the obtained equality demonstrates the <span class="hlt">absolute</span> irreversibility leads to the fundamental lower bound on the entropy production. We demonstrate the validity of the obtained equality for a simple <span class="hlt">model</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1019385','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1019385"><span id="translatedtitle"><span class="hlt">AGING</span> PERFORMANCE OF <span class="hlt">MODEL</span> 9975 PACKAGE FLUOROELASTOMER O-RINGS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hoffman, E.; Daugherty, W.; Skidmore, E.; Dunn, K.; Fisher, D.</p> <p>2011-05-31</p> <p>The influence of temperature and radiation on Viton{reg_sign} GLT and GLT-S fluoroelastomer O-rings is an ongoing research focus at the Savannah River National Laboratory. The O-rings are credited for leaktight containment in the <span class="hlt">Model</span> 9975 shipping package used for transportation of plutonium-bearing materials. At the Savannah River Site, the <span class="hlt">Model</span> 9975 packages are being used for interim storage. Primary research efforts have focused on surveillance of O-rings from actual packages, leak testing of seals at bounding <span class="hlt">aging</span> conditions and the effect of <span class="hlt">aging</span> temperature on compression stress relaxation behavior, with the goal of service life prediction for long-term storage conditions. Recently, an additional effort to evaluate the effect of <span class="hlt">aging</span> temperature on the oxidation of the materials has begun. Degradation in the mechanical properties of elastomers is directly related to the oxidation of the polymer. Sensitive measurements of the oxidation rate can be performed in a more timely manner than waiting for a measurable change in mechanical properties, especially at service temperatures. Measuring the oxidation rate therefore provides a means to validate the assumption that the degradation mechanisms(s) do not change from the elevated temperatures used for accelerated <span class="hlt">aging</span> and the lower service temperatures. Monitoring the amount of oxygen uptake by the material over time at various temperatures can provide increased confidence in lifetime predictions. Preliminary oxygen consumption analysis of a Viton GLT-based fluoroelastomer compound (Parker V0835-75) using an Oxzilla II differential oxygen analyzer in the temperature range of 40-120 C was performed. Early data suggests oxygen consumption rates may level off within the first 100,000 hours (10-12 years) at 40 C and that sharp changes in the degradation mechanism (stress-relaxation) are not expected over the temperature range examined. This is consistent with the known long-term heat <span class="hlt">aging</span> resistance of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26866587','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26866587"><span id="translatedtitle"><span class="hlt">Aging</span> and associative recognition: A view from the DRYAD <span class="hlt">model</span> of <span class="hlt">age</span>-related memory deficits.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Benjamin, Aaron S</p> <p>2016-02-01</p> <p>How do we best characterize the memory deficits that accompany <span class="hlt">aging</span>? A popular hypothesis, articulated originally by Naveh-Benjamin (2000) and reviewed in the accompanying article by Smyth and Naveh-Benjamin (2016), suggests that older adults are selectively deficient in establishing associations between to-be-learned memoranda and as a result have deficits in memory for sources or contexts. An alternative proposal, called density of representations yields <span class="hlt">age</span>-related deficits (DRYAD) and outlined in recent articles by Benjamin (2010) and colleagues (Benjamin, Diaz, Matzen, & Johnson, 2012), attributes disproportionate deficits in memory to a global, rather than a selective, deficit of memory. In an attempt to adjudicate between these competing positions, Smyth and Naveh-Benjamin (2016) discussed 2 sets of experimental data that they claim speak against the global deficit <span class="hlt">model</span>. Here I review some general principles of how the global-deficit view is applied to experimental paradigms and demonstrate that even a simplified form of DRYAD can comfortably accommodate the critical findings cited by Smyth and Naveh-Benjamin. I also evaluate aspects of their results that may be problematic for DRYAD and describe ways in which DRYAD's account of associative recognition can be falsified. I end with a discussion of the complementary strengths and weaknesses of the 2 approaches and consider ways in which the associative deficit hypothesis and DRYAD might work more profitably together than apart. PMID:26866587</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120012063','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120012063"><span id="translatedtitle">Orion <span class="hlt">Absolute</span> Navigation System Progress and Challenge</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Holt, Greg N.; D'Souza, Christopher</p> <p>2012-01-01</p> <p>The <span class="hlt">absolute</span> navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an <span class="hlt">Agee</span>-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are <span class="hlt">modeled</span> as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4462993','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4462993"><span id="translatedtitle">Cognitive <span class="hlt">aging</span> and hearing acuity: <span class="hlt">modeling</span> spoken language comprehension</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wingfield, Arthur; Amichetti, Nicole M.; Lash, Amanda</p> <p>2015-01-01</p> <p>The comprehension of spoken language has been characterized by a number of “local” theories that have focused on specific aspects of the task: <span class="hlt">models</span> of word recognition, <span class="hlt">models</span> of selective attention, accounts of thematic role assignment at the sentence level, and so forth. The ease of language understanding (ELU) <span class="hlt">model</span> (Rönnberg et al., 2013) stands as one of the few attempts to offer a fully encompassing framework for language understanding. In this paper we discuss interactions between perceptual, linguistic, and cognitive factors in spoken language understanding. Central to our presentation is an examination of aspects of the ELU <span class="hlt">model</span> that apply especially to spoken language comprehension in adult <span class="hlt">aging</span>, where speed of processing, working memory capacity, and hearing acuity are often compromised. We discuss, in relation to the ELU <span class="hlt">model</span>, conceptions of working memory and its capacity limitations, the use of linguistic context to aid in speech recognition and the importance of inhibitory control, and language comprehension at the sentence level. Throughout this paper we offer a constructive look at the ELU <span class="hlt">model</span>; where it is strong and where there are gaps to be filled. PMID:26124724</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFM.H21A1165F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFM.H21A1165F&link_type=ABSTRACT"><span id="translatedtitle">The OMS3 JGrass-New<span class="hlt">Age</span> Environmental <span class="hlt">Modelling</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Formetta, G.; David, O.; Rigon, R.</p> <p>2012-12-01</p> <p>The need for integrated analysis, and the multiplicity of possible goals in analyses that require hydro-biophysical <span class="hlt">modelling</span>, necessitates more than ever the capability of composing <span class="hlt">modelling</span> solutions with parts of known quality, which are transparent to users and consist of reusable <span class="hlt">model</span> components. Moreover, modern hydrological <span class="hlt">modelling</span> requires interaction with GIS tools to allow visualizations and the data-processing necessary to synthesise knowledge from high volumes of inputs and outputs data. Last but not least, doing science that is reproducible has requirements that go beyond the computational issues to embrace the possibility to inspection the tools, and easy compare <span class="hlt">modelling</span> solutions by third party groups. The JGrass-New<span class="hlt">Age</span> system was born in order to satisfy these requirements. It is based on the geographic information system uDig-JGrass, and is composed of two parts: (i) the system of visualization of the data and of the results based on uDig; (ii) the <span class="hlt">modelling</span> components. The latter are implemented as OMS3 components which can be connected or excluded at runtime, according to the needs and works seamlessly inside the uDig Spatial Toolbox. The system is based on a hillslope-link geometrical partition of the landscape, thus the basic unit, where the water budget is evaluated, is the hillslope, and each one of them drains into a single associated link rather than cells or pixels. To this conceptual partition corresponds an implementation of informatics that uses vectorial features for channels, and raster data for hillslopes. The mass budget for each hillslope can be performed in two ways: according to a modification of Duffy dynamical <span class="hlt">model</span> of hillslope runoff or according to HyMod lumped <span class="hlt">model</span>. Differently from traditional rainfall-runoff <span class="hlt">models</span> where the discharge is usually given at the outlet of a catchment, the discharge is evaluated in each link of the river network according to a procedure presented in Cuencas <span class="hlt">model</span>. The system includes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26752233','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26752233"><span id="translatedtitle">Learning in the temporal bisection task: Relative or <span class="hlt">absolute</span>?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>de Carvalho, Marilia Pinheiro; Machado, Armando; Tonneau, François</p> <p>2016-01-01</p> <p>We examined whether temporal learning in a bisection task is <span class="hlt">absolute</span> or relational. Eight pigeons learned to choose a red key after a t-seconds sample and a green key after a 3t-seconds sample. To determine whether they had learned a relative mapping (short→Red, long→Green) or an <span class="hlt">absolute</span> mapping (t-seconds→Red, 3t-seconds→Green), the pigeons then learned a series of new discriminations in which either the relative or the <span class="hlt">absolute</span> mapping was maintained. Results showed that the generalization gradient obtained at the end of a discrimination predicted the pattern of choices made during the first session of a new discrimination. Moreover, most acquisition curves and generalization gradients were consistent with the predictions of the learning-to-time <span class="hlt">model</span>, a Spencean <span class="hlt">model</span> that instantiates <span class="hlt">absolute</span> learning with temporal generalization. In the bisection task, the basis of temporal discrimination seems to be <span class="hlt">absolute</span>, not relational. PMID:26752233</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/941398','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/941398"><span id="translatedtitle">Overview of <span class="hlt">Modeling</span> and Simulations of Plutonium <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schwartz, A J; Wolfer, W G</p> <p>2007-04-24</p> <p>Computer-aided materials research is now an integral part of science and technology. It becomes particularly valuable when comprehensive experimental investigations and materials testing are too costly, hazardous, or of excessive duration; then, theoretical and computational studies can supplement and enhance the information gained from limited experimental data. Such is the case for improving our fundamental understanding of the properties of <span class="hlt">aging</span> plutonium in the nuclear weapons stockpile. The question of the effects of plutonium <span class="hlt">aging</span> on the safety, security, and reliability of the nuclear weapons stockpile emerged after the United States closed its plutonium manufacturing facility in 1989 and decided to suspend any further underground testing of nuclear weapons in 1992. To address this, the Department of Energy's National Nuclear Security Administration (NNSA) initiated a research program to investigate plutonium <span class="hlt">aging</span>, i.e., the changes with time of properties of Pu-Ga alloys employed in the nuclear weapons and to develop <span class="hlt">models</span> describing these changes sufficiently reliable to forecast them for several decades. The November 26, 2006 press release by the NNSA summarizes the conclusions of the investigation, '...there appear to be no serious or sudden changes occurring, or expected to occur, in plutonium that would affect performance of pits beyond the well-understood, gradual degradation of plutonium materials'. Furthermore, 'These studies show that the degradation of plutonium in our nuclear weapons will not affect warhead reliability for decades', then NNSA Administrator Linton Brooks said. 'It is now clear that although plutonium <span class="hlt">aging</span> contributes, other factors control the overall life expectancy of nuclear weapons systems'. The origin of plutonium <span class="hlt">aging</span> is the natural decay of certain plutonium isotopes. Specifically, it is the process of alpha decay in which a plutonium atom spontaneously splits into a 5 MeV alpha particle and an 85keV uranium recoil</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26056340','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26056340"><span id="translatedtitle">Blood pressure targets and <span class="hlt">absolute</span> cardiovascular risk.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Odutayo, Ayodele; Rahimi, Kazem; Hsiao, Allan J; Emdin, Connor A</p> <p>2015-08-01</p> <p>In the Eighth Joint National Committee guideline on hypertension, the threshold for the initiation of blood pressure-lowering treatment for elderly adults (≥60 years) without chronic kidney disease or diabetes mellitus was raised from 140/90 mm Hg to 150/90 mm Hg. However, the committee was not unanimous in this decision, particularly because a large proportion of adults ≥60 years may be at high cardiovascular risk. On the basis of Eighth Joint National Committee guideline, we sought to determine the <span class="hlt">absolute</span> 10-year risk of cardiovascular disease among these adults through analyzing the National Health and Nutrition Examination Survey (2005-2012). The primary outcome measure was the proportion of adults who were at ≥20% predicted <span class="hlt">absolute</span> cardiovascular risk and above goals for the Seventh Joint National Committee guideline but reclassified as at target under the Eighth Joint National Committee guideline (reclassified). The Framingham General Cardiovascular Disease Risk Score was used. From 2005 to 2012, the surveys included 12 963 adults <span class="hlt">aged</span> 30 to 74 years with blood pressure measurements, of which 914 were reclassified based on the guideline. Among individuals reclassified as not in need of additional treatment, the proportion of adults 60 to 74 years without chronic kidney disease or diabetes mellitus at ≥20% <span class="hlt">absolute</span> risk was 44.8%. This corresponds to 0.8 million adults. The proportion at high cardiovascular risk remained sizable among adults who were not receiving blood pressure-lowering treatment. Taken together, a sizable proportion of reclassified adults 60 to 74 years without chronic kidney disease or diabetes mellitus was at ≥20% <span class="hlt">absolute</span> cardiovascular risk. PMID:26056340</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/990960','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/990960"><span id="translatedtitle"><span class="hlt">Age</span>-aware solder performance <span class="hlt">models</span> : level 2 milestone completion.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Neilsen, Michael K.; Vianco, Paul Thomas; Neidigk, Matthew Aaron; Holm, Elizabeth Ann</p> <p>2010-09-01</p> <p>Legislated requirements and industry standards are replacing eutectic lead-tin (Pb-Sn) solders with lead-free (Pb-free) solders in future component designs and in replacements and retrofits. Since Pb-free solders have not yet seen service for long periods, their long-term behavior is poorly characterized. Because understanding the reliability of Pb-free solders is critical to supporting the next generation of circuit board designs, it is imperative that we develop, validate and exercise a solder lifetime <span class="hlt">model</span> that can capture the thermomechanical response of Pb-free solder joints in stockpile components. To this end, an ASC Level 2 milestone was identified for fiscal year 2010: Milestone 3605: Utilize experimentally validated constitutive <span class="hlt">model</span> for lead-free solder to simulate <span class="hlt">aging</span> and reliability of solder joints in stockpile components. This report documents the completion of this milestone, including evidence that the milestone completion criteria were met and a summary of the milestone Program Review.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17092751','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17092751"><span id="translatedtitle">The <span class="hlt">aging</span> feline kidney: a <span class="hlt">model</span> mortality antagonist?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lawler, Dennis F; Evans, Richard H; Chase, Kevin; Ellersieck, Mark; Li, Qinghong; Larson, Brian T; Satyaraj, Ebenezer; Heininger, Kurt</p> <p>2006-12-01</p> <p>Traditional thinking views apparently non-programmed disruptions of <span class="hlt">aging</span>, which medical science calls geriatric diseases, as separate from 'less harmful' morphological and physiological <span class="hlt">aging</span> phenotypes that are more universally expected with passage of time (loss of skin elasticity, graying of hair coat, weight gain, increased sleep time, behavioral changes, etc). Late-life disease phenotypes, especially those involving chronic processes, frequently are complex and very energy-expensive. A non-programmed process of homeostatic disruption leading into a death trajectory seems inconsistent with energy intensive processes. That is, evolutionary mechanisms do not favor complex and prolonged energy investment in death. Taking a different view, the naturally occurring feline (Felis silvestris catus) renal <span class="hlt">model</span> suggests that at least some diseases of late life represent only the point of failure in essentially survival-driven adaptive processes. In the feline renal <span class="hlt">model</span>, individuals that succumbed to failure most frequently displayed progressive tubular deletion and peritubular interstitial fibrosis, but had longer mean life span than cats that died from other causes. Additionally, among cats that died from non-renal causes, those that had degrees of renal tubular deletion and peritubular interstitial fibrosis also had longer mean life span than those cats with no changes, even though causes of death differed minimally between these latter two groups. The data indicate that selective tubular deletion very frequently begins early in adult life, without a clear initiating phase or event. The observations support a hypothesis that this prolonged process may be intrinsic and protective prior to an ultimate point of failure. Moreover, given the genetic complexity and the interplay with associated risk factors, existing data also do not support the ideas that these changes are simple compensatory responses and that breed- or strain-based 'default' diseases are inevitable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFM.H24F..01S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFM.H24F..01S&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Absolute</span> Humidity and the Seasonality of Influenza (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shaman, J. L.; Pitzer, V.; Viboud, C.; Grenfell, B.; Goldstein, E.; Lipsitch, M.</p> <p>2010-12-01</p> <p>Much of the observed wintertime increase of mortality in temperate regions is attributed to seasonal influenza. A recent re-analysis of laboratory experiments indicates that <span class="hlt">absolute</span> humidity strongly modulates the airborne survival and transmission of the influenza virus. Here we show that the onset of increased wintertime influenza-related mortality in the United States is associated with anomalously low <span class="hlt">absolute</span> humidity levels during the prior weeks. We then use an epidemiological <span class="hlt">model</span>, in which observed <span class="hlt">absolute</span> humidity conditions temper influenza transmission rates, to successfully simulate the seasonal cycle of observed influenza-related mortality. The <span class="hlt">model</span> results indicate that direct modulation of influenza transmissibility by <span class="hlt">absolute</span> humidity alone is sufficient to produce this observed seasonality. These findings provide epidemiological support for the hypothesis that <span class="hlt">absolute</span> humidity drives seasonal variations of influenza transmission in temperate regions. In addition, we show that variations of the basic and effective reproductive numbers for influenza, caused by seasonal changes in <span class="hlt">absolute</span> humidity, are consistent with the general timing of pandemic influenza outbreaks observed for 2009 A/H1N1 in temperate regions. Indeed, <span class="hlt">absolute</span> humidity conditions correctly identify the region of the United States vulnerable to a third, wintertime wave of pandemic influenza. These findings suggest that the timing of pandemic influenza outbreaks is controlled by a combination of <span class="hlt">absolute</span> humidity conditions, levels of susceptibility and changes in population mixing and contact rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=product+AND+advertisement&pg=4&id=EJ271019','ERIC'); return false;" href="http://eric.ed.gov/?q=product+AND+advertisement&pg=4&id=EJ271019"><span id="translatedtitle">Effect of <span class="hlt">Age</span> of <span class="hlt">Models</span> in Print Ads on Evaluation of Product and Sponsor.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rotfeld, Herbert J.; And Others</p> <p>1982-01-01</p> <p>Details a study that investigated how middle-<span class="hlt">aged</span> housewives responded to different <span class="hlt">age</span> portrayals for different <span class="hlt">age</span>-oriented products in advertisements. Concludes that there was a clear interaction between <span class="hlt">age</span>-orientation of product and <span class="hlt">age</span> of <span class="hlt">model</span> in an advertisement, but no pervasive "younger is better" effect. (FL)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMDI22A..05K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMDI22A..05K&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Modeling</span> Diverse Pathways to <span class="hlt">Age</span> Progressive Volcanism in Subduction Zones.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kincaid, C. R.; Szwaja, S.; Sylvia, R. T.; Druken, K. A.</p> <p>2015-12-01</p> <p>One of the best, and most challenging clues to unraveling mantle circulation patterns in subduction zones comes in the form of <span class="hlt">age</span> progressive volcanic and geochemical trends. Hard fought geological data from many subduction zones, like Tonga-Lau, the Cascades and Costa-Rica/Nicaragua, reveal striking temporal patterns used in defining mantle flow directions and rates. We summarize results from laboratory subduction <span class="hlt">models</span> showing a range in circulation and thermal-chemical transport processes. These interaction styles are capable of producing such trends, often reflecting apparent instead of actual mantle velocities. Lab experiments use a glucose working fluid to represent Earth's upper mantle and kinematically driven plates to produce a range in slab sinking and related wedge transport patterns. Kinematic forcing assumes most of the super-adiabatic temperature gradient available to drive major downwellings is in the tabular slabs. Moreover, sinking styles for fully dynamic subduction depend on many complicating factors that are only poorly understood and which can vary widely even for repeated parameter combinations. Kinematic <span class="hlt">models</span> have the benefit of precise, repeatable control of slab motions and wedge flow responses. Results generated with these techniques show the evolution of near-surface thermal-chemical-rheological heterogeneities leads to <span class="hlt">age</span> progressive surface expressions in a variety of ways. One set of experiments shows that rollback and back-arc extension combine to produce distinct modes of linear, <span class="hlt">age</span> progressive melt delivery to the surface through a) erosion of the rheological boundary layer beneath the overriding plate, and deformation and redistribution of both b) mantle residuum produced from decompression melting and c) formerly active, buoyant plumes. Additional experiments consider buoyant diapirs rising in a wedge under the influence of rollback, back-arc spreading and slab-gaps. Strongly deflected diapirs, experiencing variable rise</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22340056','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22340056"><span id="translatedtitle"><span class="hlt">Absolute</span> properties of the triple star HP Aurigae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lacy, Claud H. Sandberg; Burks, Charles L.; Torres, Guillermo; Wolf, Marek E-mail: clburks@email.uark.edu E-mail: wolf@cesnet.cz</p> <p>2014-01-01</p> <p>New photometric, spectroscopic, and eclipse timing observations of the eclipsing binary star HP Aur allow for very accurate orbital determinations, even in the presence of a third body and transient starspot activity. The eclipsing binary masses are determined to an accuracy of ±0.4% and the radii to ±0.6%. The masses are 0.9543 ± 0.0041 and 0.8094 ± 0.0036 solar masses, and the radii are 1.0278 ± 0.0042 and 0.7758 ± 0.0034 solar radii, respectively. The orbital period in the outer orbit is accurately determined for the first time: 4.332 ± 0.011 yr. A comparison with current theories of stellar evolution shows that the components' <span class="hlt">absolute</span> properties can be well-matched by the current <span class="hlt">models</span> at an <span class="hlt">age</span> of about 7 billion years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22034343','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22034343"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> PROPERTIES OF THE ECLIPSING BINARY STAR HY VIRGINIS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sandberg Lacy, Claud H.; Fekel, Francis C. E-mail: fekel@evans.tsuniv.edu</p> <p>2011-12-15</p> <p>HY Vir is found to be a double-lined F0m+F5 binary star with relatively shallow (0.3 mag) partial eclipses. Previous studies of the system are improved with 7509 differential photometric observations from the URSA WebScope and 8862 from the NFO WebScope, and 68 high-resolution spectroscopic observations from the Tennessee State University 2 m automatic spectroscopic telescope, and the 1 m coude-feed spectrometer at Kitt Peak National Observatory. Very accurate (better than 0.5%) masses and radii are determined from analysis of the new light curves and radial velocity curves. Theoretical <span class="hlt">models</span> match the <span class="hlt">absolute</span> properties of the stars at an <span class="hlt">age</span> of about 1.35 Gy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=isolated+neutral&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Disolated%2Bneutral','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=isolated+neutral&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Disolated%2Bneutral"><span id="translatedtitle"><span class="hlt">Absolute</span> transition probabilities of phosphorus.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, M. H.; Roig, R. A.; Bengtson, R. D.</p> <p>1971-01-01</p> <p>Use of a gas-driven shock tube to measure the <span class="hlt">absolute</span> strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25505567','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25505567"><span id="translatedtitle"><span class="hlt">Modeling</span> of <span class="hlt">age</span>-dependent amyloid accumulation and γ-secretase inhibition of soluble and insoluble Aβ in a transgenic mouse <span class="hlt">model</span> of amyloid deposition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Parkinson, Joanna; Ploeger, Bart; Appelkvist, Paulina; Bogstedt, Anna; Dillner Bergstedt, Karin; Eketjäll, Susanna; Visser, Sandra A G</p> <p>2013-12-01</p> <p>According to the "amyloid hypothesis," accumulation of amyloid beta (Aβ) peptides in the brain is linked to the development of Alzheimer's disease. The aims of this investigation were to develop a <span class="hlt">model</span> for the <span class="hlt">age</span>-dependent amyloid accumulation and to quantify the <span class="hlt">age</span>- and treatment-duration-dependent efficacy of the γ-secretase inhibitor MRK-560 in the Tg2576 transgenic mouse <span class="hlt">model</span> of amyloid deposition. Soluble and insoluble Aβ40 and Aβ42 brain concentrations were compiled from multiple naïve, vehicle, and MRK-560-treated animals. The <span class="hlt">age</span> of Tg2576 mice in the studies ranged between 3.5 and 26 months. Single doses of MRK-560 inhibited soluble Aβ40 levels in animals up to 9 months old. In contrast, MRK-560 did not cause significant acute effects on soluble Aβ40 levels in animals older than 13 months. <span class="hlt">Absolute</span> levels of Aβ variants increased exponentially over <span class="hlt">age</span> and reached a plateau at ∼20 months. In the final <span class="hlt">model</span>, it was assumed that MRK-560 inhibited the Aβ production rate with an Aβ level-dependent IC50.The <span class="hlt">age</span>-dependent increase in Aβ levels was best described by a logistic <span class="hlt">model</span> that stimulated the production rate of soluble Aβ. The increase in insoluble Aβ was defined as a function of soluble Aβ by using a scaling factor and a different turnover rate. The turnover half-life for insoluble Aβ was estimated at 30 days, explaining that at least a 4-week treatment in young animals was required to demonstrate a reduction in insoluble Aβ. Taken together, the derived knowledge could be exploited for an improved design of new experiments in Tg2576 mice. PMID:25505567</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870055286&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsaturn%2Brings','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870055286&hterms=saturn+rings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsaturn%2Brings"><span id="translatedtitle">A micrometeorite erosion <span class="hlt">model</span> and the <span class="hlt">age</span> of Saturn's rings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Northrop, T. G.; Connerney, J. E. P.</p> <p>1987-01-01</p> <p>An erosional <span class="hlt">model</span> of Saturn's rings is proposed based on theoretical studies of the high charge-to-mass ratio particles in Saturn's ring plane, and assuming that the B and C rings were initially formed as one ring with the optical thickness of the present B ring. The erosion rate is calculated using data from observed micrometeorite fluxes, and a ring <span class="hlt">age</span> of 4.4-76 Myr is determined which is inconsistent with the 4.5-Gyr ring lifetime required by the cosmogonic ring hypothesis. The sharpness of the transition between the B and C rings suggests that the principal mass loss is through particles moving at a few m/sec with respect to the parent bodies from which they were eroded.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhyA..361..239L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhyA..361..239L"><span id="translatedtitle">Ploidy, sex and crossing over in an evolutionary <span class="hlt">aging</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lobo, Matheus P.; Onody, Roberto N.</p> <p>2006-02-01</p> <p>Nowadays, many forms of reproduction coexist in nature: Asexual, sexual, apomictic and meiotic parthenogenesis, hermaphroditism and parasex. The mechanisms of their evolution and what made them successful reproductive alternatives are very challenging and debated questions. Here, using a simple evolutionary <span class="hlt">aging</span> <span class="hlt">model</span>, we give a possible scenario. By studying the performance of populations where individuals may have diverse characteristics-different ploidies, sex with or without crossing over, as well as the absence of sex-we find an evolution sequence that may explain why there are actually two major or leading groups: Sexual and asexual. We also investigate the dependence of these characteristics on different conditions of fertility and deleterious mutations. Finally, if the primeval organisms on Earth were, in fact, asexual individuals we conjecture that the sexual form of reproduction could have more easily been set and found its niche during a period of low-intensity mutations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4415892','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4415892"><span id="translatedtitle">Cellular <span class="hlt">models</span> and therapies for <span class="hlt">age</span>-related macular degeneration</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Forest, David L.; Johnson, Lincoln V.; Clegg, Dennis O.</p> <p>2015-01-01</p> <p>ABSTRACT <span class="hlt">Age</span>-related macular degeneration (AMD) is a complex neurodegenerative visual disorder that causes profound physical and psychosocial effects. Visual impairment in AMD is caused by the loss of retinal pigmented epithelium (RPE) cells and the light-sensitive photoreceptor cells that they support. There is currently no effective treatment for the most common form of this disease (dry AMD). A new approach to treating AMD involves the transplantation of RPE cells derived from either human embryonic or induced pluripotent stem cells. Multiple clinical trials are being initiated using a variety of cell therapies. Although many animal <span class="hlt">models</span> are available for AMD research, most do not recapitulate all aspects of the disease, hampering progress. However, the use of cultured RPE cells in AMD research is well established and, indeed, some of the more recently described RPE-based <span class="hlt">models</span> show promise for investigating the molecular mechanisms of AMD and for screening drug candidates. Here, we discuss innovative cell-culture <span class="hlt">models</span> of AMD and emerging stem-cell-based therapies for the treatment of this vision-robbing disease. PMID:26035859</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4211934','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4211934"><span id="translatedtitle"><span class="hlt">Age</span>-Related Effects of Alcohol from Adolescent, Adult, and <span class="hlt">Aged</span> Populations Using Human and Animal <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Squeglia, Lindsay M.; Boissoneault, Jeff; Van Skike, Candice E.; Nixon, Sara Jo; Matthews, Douglas B.</p> <p>2014-01-01</p> <p>Background This review incorporates current research examining alcohol's differential effects on adolescents, adults, and <span class="hlt">aged</span> populations in both animal and clinical <span class="hlt">models</span>. Methods The studies presented range from cognitive, behavioral, molecular, and neuroimaging techniques, leading to a more comprehensive understanding of how acute and chronic alcohol use affects the brain throughout the life span. Results <span class="hlt">Age</span> of life is a significant factor in determining the effect of alcohol on brain functioning. Adolescents and <span class="hlt">aged</span> populations may be more negatively affected by heavy alcohol use when compared to adults. Conclusions Investigations limiting alcohol effects to a single <span class="hlt">age</span> group constrains understanding of differential trajectories and outcomes following acute and chronic use. To meaningfully address the sequencing and interaction effects of alcohol and <span class="hlt">age</span>, the field must incorporate collaborative and integrated research efforts focused on interdisciplinary questions facilitated by engaging basic and applied scientists with expertise in a range of disciplines including alcohol, neurodevelopment, and <span class="hlt">aging</span>. PMID:25156779</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035416','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035416"><span id="translatedtitle">Radiocarbon <span class="hlt">ages</span> and <span class="hlt">age</span> <span class="hlt">models</span> for the past 30,000 years in Bear Lake, Utah and Idaho</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Colman, Steven M.; Rosenbaum, J.G.; Kaufman, D.S.; Dean, W.E.; McGeehin, J.P.</p> <p>2009-01-01</p> <p>Radiocarbon analyses of pollen, ostracodes, and total organic carbon (TOC) provide a reliable chronology for the sediments deposited in Bear Lake over the past 30,000 years. The differences in apparent <span class="hlt">age</span> between TOC, pollen, and carbonate fractions are consistent and in accord with the origins of these fractions. Comparisons among different fractions indicate that pollen sample <span class="hlt">ages</span> are the most reliable, at least for the past 15,000 years. The post-glacial radiocarbon data also agree with <span class="hlt">ages</span> independently estimated from aspartic acid racemization in ostracodes. <span class="hlt">Ages</span> in the red, siliclastic unit, inferred to be of last glacial <span class="hlt">age</span>, appear to be several thousand years too old, probably because of a high proportion of reworked, refractory organic carbon in the pollen samples. <span class="hlt">Age</span>-depth <span class="hlt">models</span> for five piston cores and the Bear Lake drill core (BL00-1) were constructed by using two methods: quadratic equations and smooth cubic-splinefits. The two types of <span class="hlt">age</span> <span class="hlt">models</span> differ only in detail for individual cores, and each approach has its own advantages. Specific lithological horizons were dated in several cores and correlated among them, producing robust average <span class="hlt">ages</span> for these horizons. The <span class="hlt">age</span> of the correlated horizons in the red, siliclastic unit can be estimated from the <span class="hlt">age</span> <span class="hlt">model</span> for BL00-1, which is controlled by <span class="hlt">ages</span> above and below the red, siliclastic unit. These <span class="hlt">ages</span> were then transferred to the correlative horizons in the shorter piston cores, providing control for the sections of the <span class="hlt">age</span> <span class="hlt">models</span> in those cores in the red, siliclastic unit. These <span class="hlt">age</span> <span class="hlt">models</span> are the backbone for reconstructions of past environmental conditions in Bear Lake. In general, sedimentation rates in Bear Lake have been quite uniform, mostly between 0.3 and 0.8 mm yr-1 in the Holocene, and close to 0.5 mm yr-1 for the longer sedimentary record in the drill core from the deepest part of the lake. Copyright ?? 2009 The Geological Society of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011BSRSL..80..694M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011BSRSL..80..694M"><span id="translatedtitle">Constraining the Properties of the Eta Carinae System via 3-D SPH <span class="hlt">Models</span> of Space-Based Observations: The <span class="hlt">Absolute</span> Orientation of the Binary Orbit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.</p> <p>2011-01-01</p> <p>The extremely massive (> 90 M_⊙) and luminous ( = 5 × 10^{6} L_⊙) star Eta Carinae, with its spectacular bipolar ``Homunculus'' nebula, comprises one of the most remarkable and intensely observed stellar systems in the Galaxy. However, many of its underlying physical parameters remain unknown. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e ˜ 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to tightly constrain the <span class="hlt">absolute</span> orientation of the binary orbit on the sky. An orbit with an inclination of i ˜ 40°, an argument of periapsis ω ˜ 255°, and a projected orbital axis with a position angle of ˜ 312° east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-D space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023552','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023552"><span id="translatedtitle">Constraining the Properties of the Eta Carinae System via 3-D SPH <span class="hlt">Models</span> of Space-Based Observations: The <span class="hlt">Absolute</span> Orientation of the Binary Orbit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.</p> <p>2011-01-01</p> <p>The extremely massive (> 90 Stellar Mass) and luminous (= 5 x 10(exp 6) Stellar Luminosity) star Eta Carinae, with its spectacular bipolar "Homunculus" nebula, comprises one of the most remarkable and intensely observed stellar systems in the Galaxy. However, many of its underlying physical parameters remain unknown. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e approx. 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to tightly constrain the <span class="hlt">absolute</span> orientation of the binary orbit on the sky. An orbit with an inclination of approx. 40deg, an argument of periapsis omega approx. 255deg, and a projected orbital axis with a position angle of approx. 312deg east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-D space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110007197','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110007197"><span id="translatedtitle">Constraining the Properties of the Eta Carinae System via 3-D SPH <span class="hlt">Models</span> of Space-Based Observations: The <span class="hlt">Absolute</span> Orientation of the Binary Orbit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.</p> <p>2010-01-01</p> <p>The extremely massive (> 90 Solar Mass) and luminous (= 5 x 10(exp 6) Solar Luminosity) star Eta Carinae, with its spectacular bipolar "Homunculus" nebula, comprises one of the most remarkable and intensely observed stellar systems in the galaxy. However, many of its underlying physical parameters remain a mystery. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e approx. 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision in Eta Car, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to constrain the <span class="hlt">absolute</span> orientation of the binary orbit on the sky. An orbit with an inclination of i approx. 40deg, an argument of periapsis omega approx. 255deg, and a projected orbital axis with a position angle of approx. 312deg east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-1) space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2390776','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2390776"><span id="translatedtitle">Oxidative Stress, <span class="hlt">Aging</span> and CNS disease in the Canine <span class="hlt">Model</span> of Human Brain <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Head, Elizabeth; Rofina, Jaime; Zicker, Steven</p> <p>2008-01-01</p> <p>SYNOPSIS Decline in cognitive functions that accompany <span class="hlt">aging</span> in dogs may have a biological basis, and many of the disorders associated with <span class="hlt">aging</span> in canines may be mitigated through dietary modifications that incorporate specific nutraceuticals. Based on previous research and the results of both laboratory and clinical studies – antioxidants may be one class of nutraceutical that provides benefits to <span class="hlt">aged</span> dogs. Brains of <span class="hlt">aged</span> dogs accumulate oxidative damage to proteins and lipids, which may lead to dysfunction of neuronal cells. The production of free radicals and lack of increase in compensatory antioxidant enzymes may lead to detrimental modifications to important macromolecules within neurons. Reducing oxidative damage through food ingredients rich in a broad spectrum of antioxidants significantly improves, or slows the decline of, learning and memory in <span class="hlt">aged</span> dogs. However, determining all effective compounds and combinations, dosage ranges, as well as when to initiate intervention and long term effects constitute gaps in our current knowledge. PMID:18249248</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT........58Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT........58Z"><span id="translatedtitle"><span class="hlt">Modeling</span> dynamic strain <span class="hlt">aging</span> of aluminum-magnesium alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Dawei</p> <p></p> <p>This thesis presents atomistic studies and continuum <span class="hlt">modeling</span> of solute clustering and solute diffusion in Al-Mg alloys, which are considered elements of the mechanism of dynamic strain <span class="hlt">aging</span> (DSA). Solute clustering in Al-Mg binary alloys is first studied by means of Monte-Carlo simulations. In the undistorted lattice, Mg has a tendency to form a coherent phase. The binding energy of this structure is rather low and it dissolves at room temperature when only dynamic associations of doublets or triples of solute atoms are observed. In presence of dislocations and at room temperature, Mg clusters at cores forming the coherent phase observed in the undistorted lattice at lower temperatures. The size, shape and structure of the cluster cannot be predicted by elementary calculations based on the pressure field generated by the unclustered dislocation. Then diffusion for Mg in Al-Mg alloys is investigated by Molecular Statics and the Nudged Elastic Band method. The activation energy for diffusion of Mg in the bulk is evaluated in the dilute solution limit for the nearest neighbor and the ring mechanisms. It is concluded that bulk diffusion at low and moderate temperatures must be assisted by vacancies. Further, diffusion of Mg along the core of edge, 60° and screw dislocations is studied. The vacancy formation energy in the core and the migration energy for vacancy-assisted Mg is evaluated for a large number of diffusion paths in the core region. The analysis shows that pipe diffusion; which is currently considered as the leading mechanism responsible for dynamic strain <span class="hlt">aging</span> in these alloys, is too slow in absence of excess vacancies. Finally, the time-dependent Mg solute clustering process is studied using a continuum <span class="hlt">model</span> calibrated based on atomistic information. The solute atmosphere around an edge dislocation is evaluated in terms of a chemical potential gradient, which is obtained from Monte-Carlo simulations. The solute clustering process is <span class="hlt">modeled</span> by coupled</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AIPC.1482...47A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AIPC.1482...47A&link_type=ABSTRACT"><span id="translatedtitle">Sensitivity analysis of the <span class="hlt">age</span>-structured malaria transmission <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Addawe, Joel M.; Lope, Jose Ernie C.</p> <p>2012-09-01</p> <p>We propose an <span class="hlt">age</span>-structured malaria transmission <span class="hlt">model</span> and perform sensitivity analyses to determine the relative importance of <span class="hlt">model</span> parameters to disease transmission. We subdivide the human population into two: preschool humans (below 5 years) and the rest of the human population (above 5 years). We then consider two sets of baseline parameters, one for areas of high transmission and the other for areas of low transmission. We compute the sensitivity indices of the reproductive number and the endemic equilibrium point with respect to the two sets of baseline parameters. Our simulations reveal that in areas of either high or low transmission, the reproductive number is most sensitive to the number of bites by a female mosquito on the rest of the human population. For areas of low transmission, we find that the equilibrium proportion of infectious pre-school humans is most sensitive to the number of bites by a female mosquito. For the rest of the human population it is most sensitive to the rate of acquiring temporary immunity. In areas of high transmission, the equilibrium proportion of infectious pre-school humans and the rest of the human population are both most sensitive to the birth rate of humans. This suggests that strategies that target the mosquito biting rate on pre-school humans and those that shortens the time in acquiring immunity can be successful in preventing the spread of malaria.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ClDy...30..225R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ClDy...30..225R"><span id="translatedtitle">Investigating lower stratospheric <span class="hlt">model</span> transport: Lagrangian calculations of mean <span class="hlt">age</span> and <span class="hlt">age</span> spectra in the GCM ECHAM4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reithmeier, Christian; Sausen, Robert; Grewe, Volker</p> <p>2008-02-01</p> <p>The Lagrangian scheme ATTILA is used to calculate <span class="hlt">age</span> spectra and the mean <span class="hlt">age</span> of air in the general circulation <span class="hlt">model</span> ECHAM4. The advantage of the Lagrangian method is that temporal variation in transport is taken into account and that beyond transport times the actual transport pathways can be investigated. We found a strong seasonal cycle in mean <span class="hlt">age</span> and <span class="hlt">age</span> spectra, especially at high latitudes. When plotting polar <span class="hlt">age</span> spectra against time, it can clearly be seen that the edge of the polar vortex acts as an efficient transport barrier and that exchange with extra-polar air takes place only for a short period of approximately two months after the polar vortex has broken down. Compared to observations the mean <span class="hlt">age</span> is reproduced satisfactorily below approximately 20 km. Above that level however, the mean <span class="hlt">age</span> is underestimated, especially at high latitudes. Furthermore, the observed sharp meridional gradient is located too far polewards in the <span class="hlt">model</span>, which indicates that the subtropical transport barrier is too weak. There is a distinct variation in the shape of the <span class="hlt">age</span> spectra with latitude. At low latitudes the <span class="hlt">age</span> spectra consist of one single peak, whereas at higher latitudes secondary peaks appear, which are one year apart and whose positions in the spectrum are independent of the location. At polar latitudes there are even several peaks of approximately equal size. We explain these peaks with two superposing processes. First, the seasonal cycle of the upward mass flux at the tropical tropopause produces a single peak <span class="hlt">age</span> distribution. And second, at polar latitudes, the temporal evolution of the polar vortex allows mixing of polar and subtropical air only once a year, which results in a superposition of these single peak <span class="hlt">age</span> distributions. A final investigation of the transport pathways gave indications for predominant routes from the tropics to high latitudes resulting in altitude dependent meridional transport, however, more detailed studies of 3D</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvA..94a3808D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvA..94a3808D&link_type=ABSTRACT"><span id="translatedtitle">Optomechanics for <span class="hlt">absolute</span> rotation detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davuluri, Sankar</p> <p>2016-07-01</p> <p>In this article, we present an application of optomechanical cavity for the <span class="hlt">absolute</span> rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of <span class="hlt">absolute</span> rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp"><span id="translatedtitle">The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kogut, A. J.</p> <p>2010-01-01</p> <p>The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP) is an Explorer-class mission to map the <span class="hlt">absolute</span> intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175308','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175308"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of optical flats</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sommargren, Gary E.</p> <p>2005-04-05</p> <p>The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of <span class="hlt">absolute</span> flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the <span class="hlt">absolute</span> phase error of the optical flat is obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CMaPh.309..459F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CMaPh.309..459F"><span id="translatedtitle"><span class="hlt">Aging</span> Through Hierarchical Coalescence in the East <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faggionato, A.; Martinelli, F.; Roberto, C.; Toninelli, C.</p> <p>2012-01-01</p> <p>We rigorously analyze the low temperature non-equilibrium dynamics of the East <span class="hlt">model</span>, a special example of a one dimensional oriented kinetically constrained particle <span class="hlt">model</span>, when the initial distribution is different from the reversible one and for times much smaller than the global relaxation time. This setting has been intensively studied in the physics literature to analyze the slow dynamics which follows a sudden quench from the liquid to the glass phase. In the limit of zero temperature (i.e. a vanishing density of vacancies) and for initial distributions such that the vacancies form a renewal process, we prove that the density of vacancies, the persistence function and the two-time autocorrelation function behave as staircase functions with several plateaux. Furthermore the two-time autocorrelation function displays an <span class="hlt">aging</span> behavior. We also provide a sharp description of the statistics of the domain length as a function of time, a domain being the interval between two consecutive vacancies. When the initial renewal process has finite mean, our results confirm (and generalize) previous findings of the physicists for the restricted case of a product Bernoulli measure. However we show that a different behavior appears when the initial domain distribution is in the attraction domain of a α-stable law. All the above results actually follow from a more general result which says that the low temperature dynamics of the East <span class="hlt">model</span> is very well described by that of a certain hierarchical coalescence process, a probabilistic object which can be viewed as a hierarchical sequence of suitably linked coalescence processes and whose asymptotic behavior has been recently studied in Faggionato et al. (Universality in one dimensional hierarchical 1059 coalescence processes. Preprint, 2011).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T34A..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T34A..03M"><span id="translatedtitle">Constraining <span class="hlt">age</span> and rate of deformation in the northern Bolivian Andes from cross sections, cooling <span class="hlt">ages</span>, and thermokinematic <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McQuarrie, N.; Ehlers, T. A.; Rak, A. J.</p> <p>2015-12-01</p> <p>A critical component in assessing the viability of proposed plate tectonic or geodynamic processes in regions of convergence is the expected or predicted <span class="hlt">age</span> and rate of deformation in the overriding plate. Commonly, <span class="hlt">age</span> of deformation is inferred through geochronology of foreland basin and wedge-top sedimentary rocks and bedrock thermochronometer cooling signals. In Bolivia the original pulse of deformation of the fold-thrust belt is argue to be as young as 38-25 Ma based on the <span class="hlt">age</span> of synorogenic strata or as old as 65-45 Ma due to proposed foreland basin rocks deposited in the Bolivian Altiplano. The large discrepancies in proposed <span class="hlt">age</span>, rate and magnitude of deformation through the Bolivian Andes limit our ability to relate <span class="hlt">age</span> and rate of shortening to internal geodynamic or external plate tectonic processes. We evaluate permissible ranges in <span class="hlt">age</span> of initiation and rate of deformation through a forward kinematic <span class="hlt">model</span> of the northern Bolivian fold-thrust belt. Each step of deformation accounts for isostatic loading from thrust faults and subsequent erosional of structural highs. The kinematic <span class="hlt">model</span> predicts an evolution of flexural basins into which synorogenic sediments are deposited allowing us to fully integrate <span class="hlt">age</span> of exhumation and deposition to <span class="hlt">age</span> and magnitude of deformation. By assigning an <span class="hlt">age</span> to each deformation step, we create a range of velocity vectors that are input into the thermokinematic <span class="hlt">model</span> Pecube, which predicts thermochronometer cooling histories based on kinematics, topography, thermal parameters and shortening rates. We match the pattern of predicted <span class="hlt">ages</span> with the across strike pattern of measured zircon fission track, apatite fission track and apatite (U-Th)/ He cooling <span class="hlt">ages</span>. The sensitivity of <span class="hlt">modeled</span> thermochronologic data to the <span class="hlt">age</span> at which deformation initiates indicate that northern Bolivian EC started deforming at 50 Ma and may have begun as early as 55 Ma. The acceptable velocity envelope for the <span class="hlt">modeled</span> section permits either a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFM.G11B0924M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFM.G11B0924M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Absolute</span> Antenna Calibration at the US National Geodetic Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mader, G. L.; Bilich, A. L.</p> <p>2012-12-01</p> <p>Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna <span class="hlt">models</span> and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these <span class="hlt">models</span> into analysis software. Determination of antenna phase center behavior is known as "antenna calibration". Since 1994, NGS has computed relative antenna calibrations for more than 350 antennas. In recent years, the geodetic community has moved to <span class="hlt">absolute</span> calibrations - the IGS adopted <span class="hlt">absolute</span> antenna phase center calibrations in 2006 for use in their orbit and clock products, and NGS's CORS group began using <span class="hlt">absolute</span> antenna calibration upon the release of the new CORS coordinates in IGS08 epoch 2005.00 and NAD 83(2011,MA11,PA11) epoch 2010.00. Although NGS relative calibrations can be and have been converted to <span class="hlt">absolute</span>, it is considered best practice to independently measure phase center characteristics in an <span class="hlt">absolute</span> sense. Consequently, NGS has developed and operates an <span class="hlt">absolute</span> calibration system. These <span class="hlt">absolute</span> antenna calibrations accommodate the demand for greater accuracy and for 2-dimensional (elevation and azimuth) parameterization. NGS will continue to provide calibration values via the NGS web site www.ngs.noaa.gov/ANTCAL, and will publish calibrations in the ANTEX format as well as the legacy ANTINFO</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3439638','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3439638"><span id="translatedtitle">Characterizing cognitive <span class="hlt">aging</span> in humans with links to animal <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Alexander, Gene E.; Ryan, Lee; Bowers, Dawn; Foster, Thomas C.; Bizon, Jennifer L.; Geldmacher, David S.; Glisky, Elizabeth L.</p> <p>2012-01-01</p> <p>With the population of older adults expected to grow rapidly over the next two decades, it has become increasingly important to advance research efforts to elucidate the mechanisms associated with cognitive <span class="hlt">aging</span>, with the ultimate goal of developing effective interventions and prevention therapies. Although there has been a vast research literature on the use of cognitive tests to evaluate the effects of <span class="hlt">aging</span> and <span class="hlt">age</span>-related neurodegenerative disease, the need for a set of standardized measures to characterize the cognitive profiles specific to healthy <span class="hlt">aging</span> has been widely recognized. Here we present a review of selected methods and approaches that have been applied in human research studies to evaluate the effects of <span class="hlt">aging</span> on cognition, including executive function, memory, processing speed, language, and visuospatial function. The effects of healthy <span class="hlt">aging</span> on each of these cognitive domains are discussed with examples from cognitive/experimental and clinical/neuropsychological approaches. Further, we consider those measures that have clear conceptual and methodological links to tasks currently in use for non-human animal studies of <span class="hlt">aging</span>, as well as those that have the potential for translation to animal <span class="hlt">aging</span> research. Having a complementary set of measures to assess the cognitive profiles of healthy <span class="hlt">aging</span> across species provides a unique opportunity to enhance research efforts for cross-sectional, longitudinal, and intervention studies of cognitive <span class="hlt">aging</span>. Taking a cross-species, translational approach will help to advance cognitive <span class="hlt">aging</span> research, leading to a greater understanding of associated neurobiological mechanisms with the potential for developing effective interventions and prevention therapies for <span class="hlt">age</span>-related cognitive decline. PMID:22988439</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70011263','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70011263"><span id="translatedtitle"><span class="hlt">Ages</span> estimated from a diffusion equation <span class="hlt">model</span> for scarp degradation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Colman, Steven M.; Watson, K.E.N.</p> <p>1983-01-01</p> <p>The diffusion equation derived from the continuity equation for hillslopes is applied to scarp erosion in unconsolidated materials. Solutions to this equation allow direct calculation of the product of the rate coefficient and the <span class="hlt">age</span> of the scarp from measurements of scarp morphology. Where the rate coefficient can be estimated or can be derived from scarps of known <span class="hlt">age</span>, this method allows direct calculation of unknown <span class="hlt">ages</span> of scarps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=intelligent+AND+catalyst&id=ED305048','ERIC'); return false;" href="http://eric.ed.gov/?q=intelligent+AND+catalyst&id=ED305048"><span id="translatedtitle">U.S. Telecommunications and Trade Policies: The Need for an Effective Information <span class="hlt">Age</span> <span class="hlt">Model</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tirman, W. Robert</p> <p></p> <p>This paper examines the need for telecommunications and international trade policies in the Information <span class="hlt">Age</span> and presents a <span class="hlt">model</span> for developing such policies. The first of seven sections discusses the need for an Information <span class="hlt">Age</span> <span class="hlt">Model</span>, and the technological changes that are giving rise to increasingly integrated Information <span class="hlt">Age</span> networks are…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25966656','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25966656"><span id="translatedtitle">Four-vessel occlusion <span class="hlt">model</span> using <span class="hlt">aged</span> male Wistar rats: a reliable <span class="hlt">model</span> to resolve the discrepancy related to <span class="hlt">age</span> in cerebral ischemia research.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ancer-Rodríguez, Jesús; Villarreal-Silva, Eliud Enrique; Salazar-Ybarra, Rodolfo Amador; Quiroga-García, Oscar; Rodríguez-Rocha, Humberto; García-García, Aracely; Morales-Avalos, Rodolfo; Morales-Gómez, Jesús Alberto; Quiroga-Garza, Alejandro; Saucedo-Cárdenas, Odila; Xu, Zao Cheng; Elizondo-Omaña, Rodrigo Enrique; Martínez-Ponce-de-León, Angel Raymundo; Guzmán-López, Santos</p> <p>2016-06-01</p> <p>Animal <span class="hlt">models</span> of cerebral ischemia have typically been established and performed using young animals, even though cerebral ischemia (CI) affects primarily elderly patients. This situation represents a discrepancy that complicates the translation of novel therapeutic strategies for CI. <span class="hlt">Models</span> of transient global CI using <span class="hlt">aged</span> animals have demonstrated an apparent neuroprotective effect on CA1 hippocampal neurons; however, this effect is not completely understood. Our study used a <span class="hlt">model</span> in which young (3-6 months) and <span class="hlt">aged</span> (18-21 months) male Wistar rats were subjected to 15 min of transient global CI using the four-vessel occlusion (4 VO) <span class="hlt">model</span>. We determined that the 4 VO <span class="hlt">model</span> can be performed on <span class="hlt">aged</span> rats with a slight increase in mortality rate. In <span class="hlt">aged</span> rats, the morphological damage was completely established by the 4th day after reperfusion, displaying no difference from their younger counterparts. These results demonstrated the lack of a neuroprotective effect of <span class="hlt">aging</span> on CA1 hippocampal neurons in <span class="hlt">aged</span> male Wistar rats. This study determined and characterized the morphological damage to the CA1 area after 15 min of 4 VO in <span class="hlt">aged</span> male Wistar rats, validating the use of this <span class="hlt">model</span> in CI and <span class="hlt">aging</span> research. PMID:25966656</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989ngs..rept.....P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989ngs..rept.....P"><span id="translatedtitle">The National Geodetic Survey <span class="hlt">absolute</span> gravity program</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peter, George; Moose, Robert E.; Wessells, Claude W.</p> <p>1989-03-01</p> <p>The National Geodetic Survey <span class="hlt">absolute</span> gravity program will utilize the high precision afforded by the JILAG-4 instrument to support geodetic and geophysical research, which involves studies of vertical motions, identification and <span class="hlt">modeling</span> of other temporal variations, and establishment of reference values. The scientific rationale of these objectives is given, the procedures used to collect gravity and environmental data in the field are defined, and the steps necessary to correct and remove unwanted environmental effects are stated. In addition, site selection criteria, methods of concomitant environmental data collection and relative gravity observations, and schedule and logistics are discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1186..443A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1186..443A"><span id="translatedtitle">Continuous <span class="hlt">Age</span>-Structured <span class="hlt">Model</span> for Bovine Tuberculosis in African buffalo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anguelov, R.; Kojouharov, H.</p> <p>2009-10-01</p> <p>The paper deals with a <span class="hlt">model</span> of the spread of bovine tuberculosis in the buffalo population in the Kruger National Park in South Africa. The <span class="hlt">model</span> uses continuous <span class="hlt">age</span> structure and it is formulated in terms of partial differential equations using eight epidemiological classes (compartments). More precisely, the <span class="hlt">age</span> density for each class at time t satisfies a one way wave equation, where the <span class="hlt">age</span> is the space variable. The continuous <span class="hlt">age</span> <span class="hlt">model</span> discussed here is derived from a 2006 <span class="hlt">age</span> groups <span class="hlt">model</span> by P. C. Cross and W. M. Getz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15193354','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15193354"><span id="translatedtitle">Towards a unified and interdisciplinary <span class="hlt">model</span> of <span class="hlt">ageing</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jameson, C W</p> <p>2004-01-01</p> <p>Researchers currently disagree about the appropriate biomarkers to monitor when measuring the <span class="hlt">ageing</span> process. The major problem is identifying symptoms that are an end in and of themselves, from symptoms that are tied directly to the root cause, or causes, of <span class="hlt">ageing</span>. This is most likely the reason that numerous, diverse and plausible theories for <span class="hlt">ageing</span> co-exist. When young and old nuclei are exchanged between cells, the <span class="hlt">age</span> of the resulting cell correlated with the nucleus. This suggests a large role of the nucleus as the target of <span class="hlt">ageing</span>, although the sources of <span class="hlt">ageing</span> may originate externally. There are three processes that occur when eukaryotes <span class="hlt">age</span>. They are: (1) a progressive and patterned alteration of the structure of chromosomes after young adulthood has been reached, (2) a progressive and patterned malfunction of the degradation systems, and (3) <span class="hlt">age</span>-altered post-translational modifications of proteins. A change in any one of these processes often causes a ripple effect that affects the other two processes. This paper begins by stating that the above three processes are the appropriate biomarkers of <span class="hlt">ageing</span>. These three processes are coordinated with one another under normal physiological conditions. For example, proteasomes and their subunits have been found to regulate excision repair, transcription, and the turnover of nuclear/cytoplasmic receptors. The degradation system is also responsible for the removal of oxidized histones and other factors, which influence chromosome structure. Regulatory post-translational modifications at the histone level include methylation, phosphorylation, and acetylation. In addition, the above three processes undergo <span class="hlt">age</span> related changes. Some of these modifications represent valid responses by the cell, but many do not. The effect of these <span class="hlt">age</span>-altered macromolecules is perverse and unpredictable. For example, the cell's <span class="hlt">age</span>-compromised degradation allows the accumulation of signaling complexes, which no longer match the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890031959&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DVALUE%2BABSOLUTE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890031959&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DVALUE%2BABSOLUTE"><span id="translatedtitle">Radial velocity studies and <span class="hlt">absolute</span> parameters of contact binaries. I - AB Andromedae</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hrivnak, Bruce J.</p> <p>1988-01-01</p> <p>New radial velocity curves have been obtained for the contact binary AB And, using the cross-correlation technique. A mass ratio of 0.479 is determined, which is revised to 0.491 when the velocities are corrected for proximity effects using a light curve <span class="hlt">model</span>. These values differ by less than ten percent from the photometric mass ratio. An analysis of the symmetric B and V light curves reported by Rigterink in 1973 using the spectroscopic mass ratio yields a consistent set of light and velocity curve elements. These also produce a reasonably good fit to the infrared J and K light curves reported by Jameson and Akinci in 1979. <span class="hlt">Absolute</span> elements are determined, and these indicate that both components have a main-sequence internal structure. These <span class="hlt">absolute</span> parameters, together with the Galactic kinematics, suggest an <span class="hlt">age</span> for the system similar to or greater than that of the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16231945','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16231945"><span id="translatedtitle"><span class="hlt">Absolute</span> rates of hole transfer in DNA.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Senthilkumar, Kittusamy; Grozema, Ferdinand C; Guerra, Célia Fonseca; Bickelhaupt, F Matthias; Lewis, Frederick D; Berlin, Yuri A; Ratner, Mark A; Siebbeles, Laurens D A</p> <p>2005-10-26</p> <p><span class="hlt">Absolute</span> rates of hole transfer between guanine nucleobases separated by one or two A:T base pairs in stilbenedicarboxamide-linked DNA hairpins were obtained by improved kinetic analysis of experimental data. The charge-transfer rates in four different DNA sequences were calculated using a density-functional-based tight-binding <span class="hlt">model</span> and a semiclassical superexchange <span class="hlt">model</span>. Site energies and charge-transfer integrals were calculated directly as the diagonal and off-diagonal matrix elements of the Kohn-Sham Hamiltonian, respectively, for all possible combinations of nucleobases. Taking into account the Coulomb interaction between the negative charge on the stilbenedicarboxamide linker and the hole on the DNA strand as well as effects of base pair twisting, the relative order of the experimental rates for hole transfer in different hairpins could be reproduced by tight-binding calculations. To reproduce quantitatively the <span class="hlt">absolute</span> values of the measured rate constants, the effect of the reorganization energy was taken into account within the semiclassical superexchange <span class="hlt">model</span> for charge transfer. The experimental rates could be reproduced with reorganization energies near 1 eV. The quantum chemical data obtained were used to discuss charge carrier mobility and hole-transport equilibria in DNA. PMID:16231945</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790013324','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790013324"><span id="translatedtitle">The AFGL <span class="hlt">absolute</span> gravity program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hammond, J. A.; Iliff, R. L.</p> <p>1978-01-01</p> <p>A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in <span class="hlt">absolute</span> gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26839399','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26839399"><span id="translatedtitle">The short-lived African turquoise killifish: an emerging experimental <span class="hlt">model</span> for <span class="hlt">ageing</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Yumi; Nam, Hong Gil; Valenzano, Dario Riccardo</p> <p>2016-02-01</p> <p>Human <span class="hlt">ageing</span> is a fundamental biological process that leads to functional decay, increased risk for various diseases and, ultimately, death. Some of the basic biological mechanisms underlying human <span class="hlt">ageing</span> are shared with other organisms; thus, animal <span class="hlt">models</span> have been invaluable in providing key mechanistic and molecular insights into the common bases of biological <span class="hlt">ageing</span>. In this Review, we briefly summarise the major applications of the most commonly used <span class="hlt">model</span> organisms adopted in <span class="hlt">ageing</span> research and highlight their relevance in understanding human <span class="hlt">ageing</span>. We compare the strengths and limitations of different <span class="hlt">model</span> organisms and discuss in detail an emerging <span class="hlt">ageing</span> <span class="hlt">model</span>, the short-lived African turquoise killifish. We review the recent progress made in using the turquoise killifish to study the biology of <span class="hlt">ageing</span> and discuss potential future applications of this promising animal <span class="hlt">model</span>. PMID:26839399</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4770150','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4770150"><span id="translatedtitle">The short-lived African turquoise killifish: an emerging experimental <span class="hlt">model</span> for <span class="hlt">ageing</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kim, Yumi; Nam, Hong Gil; Valenzano, Dario Riccardo</p> <p>2016-01-01</p> <p>ABSTRACT Human <span class="hlt">ageing</span> is a fundamental biological process that leads to functional decay, increased risk for various diseases and, ultimately, death. Some of the basic biological mechanisms underlying human <span class="hlt">ageing</span> are shared with other organisms; thus, animal <span class="hlt">models</span> have been invaluable in providing key mechanistic and molecular insights into the common bases of biological <span class="hlt">ageing</span>. In this Review, we briefly summarise the major applications of the most commonly used <span class="hlt">model</span> organisms adopted in <span class="hlt">ageing</span> research and highlight their relevance in understanding human <span class="hlt">ageing</span>. We compare the strengths and limitations of different <span class="hlt">model</span> organisms and discuss in detail an emerging <span class="hlt">ageing</span> <span class="hlt">model</span>, the short-lived African turquoise killifish. We review the recent progress made in using the turquoise killifish to study the biology of <span class="hlt">ageing</span> and discuss potential future applications of this promising animal <span class="hlt">model</span>. PMID:26839399</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhyA..428...52G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhyA..428...52G&link_type=ABSTRACT"><span id="translatedtitle">An agent-based computational <span class="hlt">model</span> for tuberculosis spreading on <span class="hlt">age</span>-structured populations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graciani Rodrigues, C. C.; Espíndola, Aquino L.; Penna, T. J. P.</p> <p>2015-06-01</p> <p>In this work we present an agent-based computational <span class="hlt">model</span> to study the spreading of the tuberculosis (TB) disease on <span class="hlt">age</span>-structured populations. The <span class="hlt">model</span> proposed is a merge of two previous <span class="hlt">models</span>: an agent-based computational <span class="hlt">model</span> for the spreading of tuberculosis and a bit-string <span class="hlt">model</span> for biological <span class="hlt">aging</span>. The combination of TB with the population <span class="hlt">aging</span>, reproduces the coexistence of health states, as seen in real populations. In addition, the universal exponential behavior of mortalities curves is still preserved. Finally, the population distribution as function of <span class="hlt">age</span> shows the prevalence of TB mostly in elders, for high efficacy treatments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHyd..535..652A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHyd..535..652A"><span id="translatedtitle">Urban groundwater <span class="hlt">age</span> <span class="hlt">modeling</span> under unconfined condition - Impact of underground structures on groundwater <span class="hlt">age</span>: Evidence of a piston effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Attard, Guillaume; Rossier, Yvan; Eisenlohr, Laurent</p> <p>2016-04-01</p> <p>In this paper, underground structures are shown to have a major influence on the groundwater mean <span class="hlt">age</span> distribution described as a dispersive piston effect. Urban underground development does not occur without impacts on subsoil resources. In particular, groundwater resources can be vulnerable and generate disturbances when this space is exploited. Groundwater <span class="hlt">age</span> spatial distribution data are fundamental for resource management as it can provide operational sustainability indicators. However, the application of groundwater <span class="hlt">age</span> <span class="hlt">modeling</span> is neglected regarding the potential effect of underground structures in urban areas. A three dimensional <span class="hlt">modeling</span> approach was conducted to quantify the impact of two underground structures: (1) an impervious structure and (2) a draining structure. Both structures are shown to cause significant mixing processes occurring between shallow and deeper aquifers. The design technique used for draining structures is shown to have the greatest impact, generating a decrease in mean <span class="hlt">age</span> of more than 80% under the structure. Groundwater <span class="hlt">age</span> <span class="hlt">modeling</span> is shown to be relevant for highlighting the role played by underground structures in advective-dispersive flows in urban areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22109384','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22109384"><span id="translatedtitle"><span class="hlt">Modelling</span> <span class="hlt">aging</span> effects on a thermal cycling absorption process column</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Laquerbe, C.; Contreras, S.; Demoment, J.</p> <p>2008-07-15</p> <p>Palladium coated on alumina is used in hydrogen separation systems operated at CEA/Valduc, and more particularly in Thermal Cycling Absorption Process columns. With such materials, tritium decay is known to induce <span class="hlt">aging</span> effects which have direct side effects on hydrogen isotopes absorption isotherms. Furthermore in a TCAP column, <span class="hlt">aging</span> occurs in an heterogeneous way. The possible impacts of these intrinsic material evolutions on the separation performances are investigated here through a numerical approach. (authors)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=climate+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dclimate%2Bchange','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=climate+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dclimate%2Bchange"><span id="translatedtitle">Achieving Climate Change <span class="hlt">Absolute</span> Accuracy in Orbit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.</p> <p>2013-01-01</p> <p>The Climate <span class="hlt">Absolute</span> Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high <span class="hlt">absolute</span> radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high <span class="hlt">absolute</span> accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate <span class="hlt">model</span> predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21177306','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21177306"><span id="translatedtitle">Bivariate random effects <span class="hlt">models</span> for meta-analysis of comparative studies with binary outcomes: methods for the <span class="hlt">absolute</span> risk difference and relative risk.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chu, Haitao; Nie, Lei; Chen, Yong; Huang, Yi; Sun, Wei</p> <p>2012-12-01</p> <p>Multivariate meta-analysis is increasingly utilised in biomedical research to combine data of multiple comparative clinical studies for evaluating drug efficacy and safety profile. When the probability of the event of interest is rare, or when the individual study sample sizes are small, a substantial proportion of studies may not have any event of interest. Conventional meta-analysis methods either exclude such studies or include them through ad hoc continuality correction by adding an arbitrary positive value to each cell of the corresponding 2 × 2 tables, which may result in less accurate conclusions. Furthermore, different continuity corrections may result in inconsistent conclusions. In this article, we discuss a bivariate Beta-binomial <span class="hlt">model</span> derived from Sarmanov family of bivariate distributions and a bivariate generalised linear mixed effects <span class="hlt">model</span> for binary clustered data to make valid inferences. These bivariate random effects <span class="hlt">models</span> use all available data without ad hoc continuity corrections, and accounts for the potential correlation between treatment (or exposure) and control groups within studies naturally. We then utilise the bivariate random effects <span class="hlt">models</span> to reanalyse two recent meta-analysis data sets. PMID:21177306</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15016469','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15016469"><span id="translatedtitle">Source apportionment of ambient non-methane hydrocarbons in Hong Kong: application of a principal component analysis/<span class="hlt">absolute</span> principal component scores (PCA/APCS) receptor <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, H; Wang, T; Louie, P K K</p> <p>2004-06-01</p> <p>Receptor-oriented source apportionment <span class="hlt">models</span> are often used to identify sources of ambient air pollutants and to estimate source contributions to air pollutant concentrations. In this study, a PCA/APCS <span class="hlt">model</span> was applied to the data on non-methane hydrocarbons (NMHCs) measured from January to December 2001 at two sampling sites: Tsuen Wan (TW) and Central & Western (CW) Toxic Air Pollutants Monitoring Stations in Hong Kong. This multivariate method enables the identification of major air pollution sources along with the quantitative apportionment of each source to pollutant species. The PCA analysis identified four major pollution sources at TW site and five major sources at CW site. The extracted pollution sources included vehicular internal engine combustion with unburned fuel emissions, use of solvent particularly paints, liquefied petroleum gas (LPG) or natural gas leakage, and industrial, commercial and domestic sources such as solvents, decoration, fuel combustion, chemical factories and power plants. The results of APCS receptor <span class="hlt">model</span> indicated that 39% and 48% of the total NMHCs mass concentrations measured at CW and TW were originated from vehicle emissions, respectively. 32% and 36.4% of the total NMHCs were emitted from the use of solvent and 11% and 19.4% were apportioned to the LPG or natural gas leakage, respectively. 5.2% and 9% of the total NMHCs mass concentrations were attributed to other industrial, commercial and domestic sources, respectively. It was also found that vehicle emissions and LPG or natural gas leakage were the main sources of C(3)-C(5) alkanes and C(3)-C(5) alkenes while aromatics were predominantly released from paints. Comparison of source contributions to ambient NMHCs at the two sites indicated that the contribution of LPG or natural gas at CW site was almost twice that at TW site. High correlation coefficients (R(2) > 0.8) between the measured and predicted values suggested that the PCA/APCS <span class="hlt">model</span> was applicable for estimation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27114843','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27114843"><span id="translatedtitle"><span class="hlt">Aging</span> and Neurodegeneration: A Tangle of <span class="hlt">Models</span> and Mechanisms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chakrabarti, Sasanka; Mohanakumar, Kochupurackal P</p> <p>2016-03-01</p> <p>The research on <span class="hlt">aging</span> and <span class="hlt">age</span>-related diseases, especially the neurodegenerative diseases, is on the fast track. However, the results have so far not been translated to actual benefit for the patients in terms of treatment or diagnosis of <span class="hlt">age</span>-related degenerative diseases including those of the CNS. As far as the prevention of the cognitive decline during non-pathological <span class="hlt">aging</span> is concerned, there is nothing much to offer other than calorie restriction and physical exercise. Needless to say, the benefits are not up to our expectations. However, over the years at the experimental level it has been possible to identify several cellular and molecular mechanisms that are intricately associated with <span class="hlt">aging</span> in general and neurodegenerative diseases in particular. These include oxidative stress and altered redox-signaling, mitochondrial dysfunction, inflammation, proteotoxicity and altered gene expressions. These inter-dependent pathways mediate cellular senescence and often culminate in programmed cell death like apoptosis and autophagy, and in the context of brain these changes are manifested clinically as cognitive decline and pathologically as neurodegeneration. This special issue provides the readers with glimpses of this complex scenario from different angles primarily in the context of brain and also attempts to identify the potential drug targets against neurodegenerative diseases. PMID:27114843</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4809602','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4809602"><span id="translatedtitle"><span class="hlt">Aging</span> and Neurodegeneration: A Tangle of <span class="hlt">Models</span> and Mechanisms</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chakrabarti, Sasanka; Mohanakumar, Kochupurackal P.</p> <p>2016-01-01</p> <p>The research on <span class="hlt">aging</span> and <span class="hlt">age</span>-related diseases, especially the neurodegenerative diseases, is on the fast track. However, the results have so far not been translated to actual benefit for the patients in terms of treatment or diagnosis of <span class="hlt">age</span>-related degenerative diseases including those of the CNS. As far as the prevention of the cognitive decline during non-pathological <span class="hlt">aging</span> is concerned, there is nothing much to offer other than calorie restriction and physical exercise. Needless to say, the benefits are not up to our expectations. However, over the years at the experimental level it has been possible to identify several cellular and molecular mechanisms that are intricately associated with <span class="hlt">aging</span> in general and neurodegenerative diseases in particular. These include oxidative stress and altered redox-signaling, mitochondrial dysfunction, inflammation, proteotoxicity and altered gene expressions. These inter-dependent pathways mediate cellular senescence and often culminate in programmed cell death like apoptosis and autophagy, and in the context of brain these changes are manifested clinically as cognitive decline and pathologically as neurodegeneration. This special issue provides the readers with glimpses of this complex scenario from different angles primarily in the context of brain and also attempts to identify the potential drug targets against neurodegenerative diseases. PMID:27114843</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4637594','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4637594"><span id="translatedtitle">Abnormal glutamate release in <span class="hlt">aged</span> BTBR mouse <span class="hlt">model</span> of autism</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wei, Hongen; Ding, Caiyun; Jin, Guorong; Yin, Haizhen; Liu, Jianrong; Hu, Fengyun</p> <p>2015-01-01</p> <p>Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. Most of the available research on autism is focused on children and young adults and little is known about the pathological alternation of autism in older adults. In order to investigate the neurobiological alternation of autism in old <span class="hlt">age</span> stage, we compared the morphology and synaptic function of excitatory synapses between the BTBR mice with low level sociability and B6 mice with high level sociability. The results revealed that the number of excitatory synapse colocalized with pre- and post-synaptic marker was not different between <span class="hlt">aged</span> BTBR and B6 mice. The <span class="hlt">aged</span> BTBR mice had a normal structure of dendritic spine and the expression of Shank3 protein in the brain as well as that in B6 mice. The baseline and KCl-evoked glutamate release from the cortical synaptoneurosome in <span class="hlt">aged</span> BTBR mice was lower than that in <span class="hlt">aged</span> B6 mice. Overall, the data indicate that there is a link between disturbances of the glutamate transmission and autism. These findings provide new evidences for the hypothesis of excitation/inhibition imbalance in autism. Further work is required to determine the cause of this putative abnormality. PMID:26617779</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JCAP...08..060V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JCAP...08..060V&link_type=ABSTRACT"><span id="translatedtitle">Cosmology with negative <span class="hlt">absolute</span> temperatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony</p> <p>2016-08-01</p> <p>Negative <span class="hlt">absolute</span> temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < ‑1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998JCP....95..357S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998JCP....95..357S&link_type=ABSTRACT"><span id="translatedtitle">NMR and molecular <span class="hlt">modeling</span>: application to wine <span class="hlt">ageing</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saucier, C.; Pianet, I.; Laguerre, M.; Glories, Y.</p> <p>1998-02-01</p> <p>Red wine contains polyphenols called tannins which are very important for its taste and longevity. These polymers consist in repeating units of catechin and its epimer epicatechin. During <span class="hlt">ageing</span>, slow condensation reactions take place which lead to new chemical structures. Among the possible reactions, we have focused our attention on acetaldehyde cross-linking. Catechin was used as a <span class="hlt">model</span> for the production of polymers with acetaldehyde. Two reaction product fractions have been isolated by liquid chromatography. Mass measurement indicated that these fractions contain dimers. NMR (1D and 2D) and molecular <span class="hlt">modelling</span> were then used to study the structure and conformations of these products. The first product consist in a pure dimer with the two catechin moieties connected with an ethyl bridge on the carbon 6 and 8. The second fraction was a mixture of two dimers (50/50). NMR measurements showed that it could be two symmetrical dimers involving the same carbon for each catechin moiety (6 or8). Le vin rouge contient des polyphénols appelés tanins qui sont très importants pour son goût et sa longévité. Il s'agit principalement de polymères de catéchine et d'épicatéchine. Durant le vieillissement du vin, des réactions de condensation interviennent lentement et conduisent à de nouvelles structures. Parmi les réactions possibles, nous avons plus spécialement étudié la polymérisation par pontage avec l'éthanal. La catéchine a été utilisée comme modèle de tannin et mise en présence d'éthanal en milieu acide proche du vin. Deux fractions de produits de réaction ont été isolées par chromatographie liquide. La spectrométrie de masse a révélé la présence de dimères. La RMN (1D et 2D) et la modélisation moléculaire ont ensuite été utilisées pour déterminer la structure et la conformation de ces produits. La première fraction a été identifiée comme étant un dimère de deux unités catéchines reliées par un pont éthyle par leur</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.P43A0910F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.P43A0910F"><span id="translatedtitle">Maximum <span class="hlt">Age</span> Predictions for Optical Dating on Mars Based on Dose/Depth <span class="hlt">Models</span> and Martian Meteorite Compositions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Franklund, R. T.; Lepper, K.</p> <p>2004-12-01</p> <p>A fundamental need in the Mars exploration portfolio is in-situ <span class="hlt">absolute</span> dating. Optical dating has been proposed for determining the <span class="hlt">age</span> of Mars surface features and landforms as well as the rates of martian surface processes. On Earth, the method is employed for Quaternary studies because the technique currently has a terrestrial maximum <span class="hlt">age</span> limit of approximately 350 ka. This maximum <span class="hlt">age</span> limit is a function of the saturation dose of the dosimeter material (silicate sediments) and the local ionizing radiation dose rate. The sources of ionizing radiation germane to optical dating are K, Rb, U, Th in the sediment/soil environment and cosmic rays. On Mars the near surface dose rate will be dominated by cosmic rays, however, at depth the decay of radioisotopes will be the principle contributor of ionizing radiation. In this work we present an evaluation of the maximum <span class="hlt">age</span> limits for OSL dating on Mars as a function of depth. At this time we have considered only static burial. Our calculations are based on published <span class="hlt">models</span> of and data for: (i) Mars surface cosmic dose rate and its attenuation by martian regolith, (ii) elemental analyses of Mars meteorites, (iii) an experimental evaluation of the saturation dose for the martian soil simulant JSC Mars-1. Our analysis confirms earlier inferences that optical dating should have a greater effective <span class="hlt">age</span> range on Mars than on Earth. At depths easily accessible by penetrators or moles (1-3 m), maximum optical <span class="hlt">ages</span> greater than 600 ka are possible. Geochronology on this scale would include at least two stadial/interstadial cycles within Mars' last "Glacial Epoch" (synchronized insolation variations between the poles). A wide range of landforms and surface processes associated with climate variability -- e.g. outwash and lacustrine deposition, large-scale eolian activation -- could potentially be optically dated. At greater depths, that could be reached by mobile drilling rigs or cryobots (10-30m), optical <span class="hlt">age</span> maximums of 4</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhFl...27a4110R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhFl...27a4110R"><span id="translatedtitle"><span class="hlt">Absolute</span>/convective instability of planar viscoelastic jets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ray, Prasun K.; Zaki, Tamer A.</p> <p>2015-01-01</p> <p>Spatiotemporal linear stability analysis is used to investigate the onset of local <span class="hlt">absolute</span> instability in planar viscoelastic jets. The influence of viscoelasticity in dilute polymer solutions is <span class="hlt">modeled</span> with the FENE-P constitutive equation which requires the specification of a non-dimensional polymer relaxation time (the Weissenberg number, We), the maximum polymer extensibility, L, and the ratio of solvent and solution viscosities, β. A two-parameter family of velocity profiles is used as the base state with the parameter, S, controlling the amount of co- or counter-flow while N-1 sets the thickness of the jet shear layer. We examine how the variation of these fluid and flow parameters affects the minimum value of S at which the flow becomes locally <span class="hlt">absolutely</span> unstable. Initially setting the Reynolds number to Re = 500, we find that the first varicose jet-column mode dictates the presence of <span class="hlt">absolute</span> instability, and increasing the Weissenberg number produces important changes in the nature of the instability. The region of <span class="hlt">absolute</span> instability shifts towards thin shear layers, and the amount of back-flow needed for <span class="hlt">absolute</span> instability decreases (i.e., the influence of viscoelasticity is destabilizing). Additionally, when We is sufficiently large and N-1 is sufficiently small, single-stream jets become <span class="hlt">absolutely</span> unstable. Numerical experiments with approximate equations show that both the polymer and solvent contributions to the stress become destabilizing when the scaled shear rate, η = /W e dU¯1/dx 2L ( /d U ¯ 1 d x 2 is the base-state velocity gradient), is sufficiently large. These qualitative trends are largely unchanged when the Reynolds number is reduced; however, the relative importance of the destabilizing stresses increases tangibly. Consequently, <span class="hlt">absolute</span> instability is substantially enhanced, and single-stream jets become <span class="hlt">absolutely</span> unstable over a sizable portion of the parameter space.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=tuckman+AND+model&pg=3&id=EJ102298','ERIC'); return false;" href="http://eric.ed.gov/?q=tuckman+AND+model&pg=3&id=EJ102298"><span id="translatedtitle">An <span class="hlt">Age</span>-Graded <span class="hlt">Model</span> for Career Development Education</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tuckman, Bruce W.</p> <p>1974-01-01</p> <p>This paper attempts to provide a framework by which educators interested in stimulating career development can choose the learning experiences most likely to have payoffs for different <span class="hlt">age</span> youth. Eight stages of child development are described with career development themes suggested for each stage along with sample activities. (Author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=encode&pg=7&id=EJ1005699','ERIC'); return false;" href="http://eric.ed.gov/?q=encode&pg=7&id=EJ1005699"><span id="translatedtitle"><span class="hlt">Aging</span> and Predicting Inferences: A Diffusion <span class="hlt">Model</span> Analysis</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>McKoon, Gail; Ratcliff, Roger</p> <p>2013-01-01</p> <p>In the domain of discourse processing, it has been claimed that older adults (60-0-year-olds) are less likely to encode and remember some kinds of information from texts than young adults. The experiment described here shows that they do make a particular kind of inference to the same extent that college-<span class="hlt">age</span> adults do. The inferences examined were…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=sibling+AND+rivalry&pg=3&id=ED227385','ERIC'); return false;" href="http://eric.ed.gov/?q=sibling+AND+rivalry&pg=3&id=ED227385"><span id="translatedtitle">An Attachment <span class="hlt">Model</span> of Sibling Helping Behavior in Old <span class="hlt">Age</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Cicirelli, Victor G.</p> <p></p> <p>Sibling relationships are not only maintained throughout life in most cases, but assume considerable importance in old <span class="hlt">age</span>. Siblings provide psychological support for each other as well as more tangible forms of helping and caregiving. In order to investigate variables leading to sibling help in the area of psychological support, a path model…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4255604','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4255604"><span id="translatedtitle">Phospholipase A2 – nexus of <span class="hlt">aging</span>, oxidative stress, neuronal excitability, and functional decline of the <span class="hlt">aging</span> nervous system? Insights from a snail <span class="hlt">model</span> system of neuronal <span class="hlt">aging</span> and <span class="hlt">age</span>-associated memory impairment</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hermann, Petra M.; Watson, Shawn N.; Wildering, Willem C.</p> <p>2014-01-01</p> <p>The <span class="hlt">aging</span> brain undergoes a range of changes varying from subtle structural and physiological changes causing only minor functional decline under healthy normal <span class="hlt">aging</span> conditions, to severe cognitive or neurological impairment associated with extensive loss of neurons and circuits due to <span class="hlt">age</span>-associated neurodegenerative disease conditions. Understanding how biological <span class="hlt">aging</span> processes affect the brain and how they contribute to the onset and progress of <span class="hlt">age</span>-associated neurodegenerative diseases is a core research goal in contemporary neuroscience. This review focuses on the idea that changes in intrinsic neuronal electrical excitability associated with (per)oxidation of membrane lipids and activation of phospholipase A2 (PLA2) enzymes are an important mechanism of learning and memory failure under normal <span class="hlt">aging</span> conditions. Specifically, in the context of this special issue on the biology of cognitive <span class="hlt">aging</span> we portray the opportunities offered by the identifiable neurons and behaviorally characterized neural circuits of the freshwater snail Lymnaea stagnalis in neuronal <span class="hlt">aging</span> research and recapitulate recent insights indicating a key role of lipid peroxidation-induced PLA2 as instruments of <span class="hlt">aging</span>, oxidative stress and inflammation in <span class="hlt">age</span>-associated neuronal and memory impairment in this <span class="hlt">model</span> system. The findings are discussed in view of accumulating evidence suggesting involvement of analogous mechanisms in the etiology of <span class="hlt">age</span>-associated dysfunction and disease of the human and mammalian brain. PMID:25538730</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.2540T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.2540T&link_type=ABSTRACT"><span id="translatedtitle">All <span class="hlt">age</span>-depth <span class="hlt">models</span> are wrong, but are getting better</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trachsel, Mathias; Chipperfield, Joseph D.; Telford, Richard J.</p> <p>2015-04-01</p> <p>Construction of accurate <span class="hlt">age</span>-depth relationships and realistic assessment of their uncertainties is one of the fundamental prerequisites for comparing and correlating Late Quaternary stratigraphic proxy records. Four widely used <span class="hlt">age</span>-depth <span class="hlt">modelling</span> routines: i) clam, ii) OxCal, iii) Bacon, and iv) Bchron were tested using radiocarbon dates simulated from varved sediment stratigraphies. All methods produced average <span class="hlt">age</span>-depth <span class="hlt">models</span> that were close to the true varve <span class="hlt">age</span>, but the uncertainty estimation differed considerably among <span class="hlt">models</span>. <span class="hlt">Age</span> uncertainties were underestimated by clam, whereas <span class="hlt">age</span> uncertainties produced by Bchron were too large. Using OxCal and Bacon, setting of <span class="hlt">model</span> specific parameters influenced the estimated uncertainties, which varied from too large to too small. Still, compared to the study by Telford et al. (2004), the use of Bayesian <span class="hlt">age</span>-depth <span class="hlt">models</span> greatly improved on the assessment of uncertainties of <span class="hlt">age</span>-depth <span class="hlt">models</span>. Reference: Telford et al. (2004), All <span class="hlt">age</span>-depth <span class="hlt">models</span> are wrong: but how badly? Quaternary Science Reviews, 23,1-5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100012866','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100012866"><span id="translatedtitle"><span class="hlt">Modeling</span> the Information <span class="hlt">Age</span> Combat <span class="hlt">Model</span>: An Agent-Based Simulation of Network Centric Operations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deller, Sean; Rabadi, Ghaith A.; Bell, Michael I.; Bowling, Shannon R.; Tolk, Andreas</p> <p>2010-01-01</p> <p>The Information <span class="hlt">Age</span> Combat <span class="hlt">Model</span> (IACM) was introduced by Cares in 2005 to contribute to the development of an understanding of the influence of connectivity on force effectiveness that can eventually lead to quantitative prediction and guidelines for design and employment. The structure of the IACM makes it clear that the Perron-Frobenius Eigenvalue is a quantifiable metric with which to measure the organization of a networked force. The results of recent experiments presented in Deller, et aI., (2009) indicate that the value of the Perron-Frobenius Eigenvalue is a significant measurement of the performance of an Information <span class="hlt">Age</span> combat force. This was accomplished through the innovative use of an agent-based simulation to <span class="hlt">model</span> the IACM and represents an initial contribution towards a new generation of combat <span class="hlt">models</span> that are net-centric instead of using the current platform-centric approach. This paper describes the intent, challenges, design, and initial results of this agent-based simulation <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70025069','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70025069"><span id="translatedtitle"><span class="hlt">Absolute</span> irradiance of the Moon for on-orbit calibration</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stone, T.C.; Kieffer, H.H.</p> <p>2002-01-01</p> <p>The recognized need for on-orbit calibration of remote sensing imaging instruments drives the ROLO project effort to characterize the Moon for use as an <span class="hlt">absolute</span> radiance source. For over 5 years the ground-based ROLO telescopes have acquired spatially-resolved lunar images in 23 VNIR (Moon diameter ???500 pixels) and 9 SWIR (???250 pixels) passbands at phase angles within ??90 degrees. A numerical <span class="hlt">model</span> for lunar irradiance has been developed which fits hundreds of ROLO images in each band, corrected for atmospheric extinction and calibrated to <span class="hlt">absolute</span> radiance, then integrated to irradiance. The band-coupled extinction algorithm uses absorption spectra of several gases and aerosols derived from MODTRAN to fit time-dependent component abundances to nightly observations of standard stars. The <span class="hlt">absolute</span> radiance scale is based upon independent telescopic measurements of the star Vega. The fitting process yields uncertainties in lunar relative irradiance over small ranges of phase angle and the full range of lunar libration well under 0.5%. A larger source of uncertainty enters in the <span class="hlt">absolute</span> solar spectral irradiance, especially in the SWIR, where solar <span class="hlt">models</span> disagree by up to 6%. Results of ROLO <span class="hlt">model</span> direct comparisons to spacecraft observations demonstrate the ability of the technique to track sensor responsivity drifts to sub-percent precision. Intercomparisons among instruments provide key insights into both calibration issues and the <span class="hlt">absolute</span> scale for lunar irradiance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26648865','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26648865"><span id="translatedtitle"><span class="hlt">Age</span>-Related Changes in Predictive Capacity Versus Internal <span class="hlt">Model</span> Adaptability: Electrophysiological Evidence that Individual Differences Outweigh Effects of <span class="hlt">Age</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bornkessel-Schlesewsky, Ina; Philipp, Markus; Alday, Phillip M; Kretzschmar, Franziska; Grewe, Tanja; Gumpert, Maike; Schumacher, Petra B; Schlesewsky, Matthias</p> <p>2015-01-01</p> <p>Hierarchical predictive coding has been identified as a possible unifying principle of brain function, and recent work in cognitive neuroscience has examined how it may be affected by <span class="hlt">age</span>-related changes. Using language comprehension as a test case, the present study aimed to dissociate <span class="hlt">age</span>-related changes in prediction generation versus internal <span class="hlt">model</span> adaptation following a prediction error. Event-related brain potentials (ERPs) were measured in a group of older adults (60-81 years; n = 40) as they read sentences of the form "The opposite of black is white/yellow/nice." Replicating previous work in young adults, results showed a target-related P300 for the expected antonym ("white"; an effect assumed to reflect a prediction match), and a graded N400 effect for the two incongruous conditions (i.e. a larger N400 amplitude for the incongruous continuation not related to the expected antonym, "nice," versus the incongruous associated condition, "yellow"). These effects were followed by a late positivity, again with a larger amplitude in the incongruous non-associated versus incongruous associated condition. Analyses using linear mixed-effects <span class="hlt">models</span> showed that the target-related P300 effect and the N400 effect for the incongruous non-associated condition were both modulated by <span class="hlt">age</span>, thus suggesting that <span class="hlt">age</span>-related changes affect both prediction generation and <span class="hlt">model</span> adaptation. However, effects of <span class="hlt">age</span> were outweighed by the interindividual variability of ERP responses, as reflected in the high proportion of variance captured by the inclusion of by-condition random slopes for participants and items. We thus argue that - at both a neurophysiological and a functional level - the notion of general differences between language processing in young and older adults may only be of limited use, and that future research should seek to better understand the causes of interindividual variability in the ERP responses of older adults and its relation to cognitive performance. PMID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED374240.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED374240.pdf"><span id="translatedtitle">The Statewide Training <span class="hlt">Model</span> for a Continuing Education Certificate in Gerontology in Religion and <span class="hlt">Aging</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Thompson, Barbara, Ed.; Payne, Barbara, Ed.</p> <p></p> <p>This training <span class="hlt">model</span> is a guide for developing statewide training for a continuing education certificate in gerontology in religion and <span class="hlt">aging</span>. It is designed for use by gerontology educators, state office of <span class="hlt">aging</span> executives, and leaders of religious judicatories. Section I begins with a description of the training <span class="hlt">model</span> and covers where and how to…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4496580','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4496580"><span id="translatedtitle">Muscle wasting in myotonic dystrophies: a <span class="hlt">model</span> of premature <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mateos-Aierdi, Alba Judith; Goicoechea, Maria; Aiastui, Ana; Fernández-Torrón, Roberto; Garcia-Puga, Mikel; Matheu, Ander; López de Munain, Adolfo</p> <p>2015-01-01</p> <p>Myotonic dystrophy type 1 (DM1 or Steinert’s disease) and type 2 (DM2) are multisystem disorders of genetic origin. Progressive muscular weakness, atrophy and myotonia are the most prominent neuromuscular features of these diseases, while other clinical manifestations such as cardiomyopathy, insulin resistance and cataracts are also common. From a clinical perspective, most DM symptoms are interpreted as a result of an accelerated <span class="hlt">aging</span> (cataracts, muscular weakness and atrophy, cognitive decline, metabolic dysfunction, etc.), including an increased risk of developing tumors. From this point of view, DM1 could be described as a progeroid syndrome since a notable <span class="hlt">age</span>-dependent dysfunction of all systems occurs. The underlying molecular disorder in DM1 consists of the existence of a pathological (CTG) triplet expansion in the 3′ untranslated region (UTR) of the Dystrophia Myotonica Protein Kinase (DMPK) gene, whereas (CCTG)n repeats in the first intron of the Cellular Nucleic acid Binding Protein/Zinc Finger Protein 9 (CNBP/ZNF9) gene cause DM2. The expansions are transcribed into (CUG)n and (CCUG)n-containing RNA, respectively, which form secondary structures and sequester RNA-binding proteins, such as the splicing factor muscleblind-like protein (MBNL), forming nuclear aggregates known as foci. Other splicing factors, such as CUGBP, are also disrupted, leading to a spliceopathy of a large number of downstream genes linked to the clinical features of these diseases. Skeletal muscle regeneration relies on muscle progenitor cells, known as satellite cells, which are activated after muscle damage, and which proliferate and differentiate to muscle cells, thus regenerating the damaged tissue. Satellite cell dysfunction seems to be a common feature of both <span class="hlt">age</span>-dependent muscle degeneration (sarcopenia) and muscle wasting in DM and other muscle degenerative diseases. This review aims to describe the cellular, molecular and macrostructural processes involved in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhRvL..74.2114F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhRvL..74.2114F"><span id="translatedtitle">Glassy Transition and <span class="hlt">Aging</span> in a <span class="hlt">Model</span> Without Disorder</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Franz, Silvio; Hertz, John</p> <p>1995-03-01</p> <p>We study the off-equilibrium relaxational dynamics of the Amit-Roginsky φ3 field theory, for which the mode coupling approximation is exact. We show that complex phenomena such as <span class="hlt">aging</span> and ergodicity breaking are present at low temperature, similar to what is found in long range spin glasses. This is an example of how the mode coupling theory of the structural glass transition can be generalized to off-equilibrium situations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5013733','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5013733"><span id="translatedtitle">Joint Bayesian analysis of birthweight and censored gestational <span class="hlt">age</span> using finite mixture <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schwartz, Scott L.; Gelfand, Alan E.; Miranda, Marie L.</p> <p>2016-01-01</p> <p>Birthweight and gestational <span class="hlt">age</span> are closely related and represent important indicators of a healthy pregnancy. Customary <span class="hlt">modeling</span> for birthweight is conditional on gestational <span class="hlt">age</span>. However, joint <span class="hlt">modeling</span> directly addresses the relationship between gestational <span class="hlt">age</span> and birthweight, and provides increased flexibility and interpretation as well as a strategy to avoid using gestational <span class="hlt">age</span> as an intermediate variable. Previous proposals have utilized finite mixtures of bivariate regression <span class="hlt">models</span> to incorporate well-established risk factors into analysis (e.g. sex and birth order of the baby, maternal <span class="hlt">age</span>, race, and tobacco use) while examining the non-Gaussian shape of the joint birthweight and gestational <span class="hlt">age</span> distribution. We build on this approach by demonstrating the inferential (prognostic) benefits of joint <span class="hlt">modeling</span> (e.g. investigation of `<span class="hlt">age</span> inappropriate' outcomes like small for gestational <span class="hlt">age</span>) and hence re-emphasize the importance of capturing the non-Gaussian distributional shapes. We additionally extend current <span class="hlt">models</span> through a latent specification which admits interval-censored gestational <span class="hlt">age</span>. We work within a Bayesian framework which enables inference beyond customary parameter estimation and prediction as well as exact uncertainty assessment. The <span class="hlt">model</span> is applied to a portion of the 2003–2006 North Carolina Detailed Birth Record data (n=336129) available through the Children's Environmental Health Initiative and is fitted using the Bayesian methodology and Markov chain Monte Carlo approaches. PMID:20575047</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4096444','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4096444"><span id="translatedtitle">Evaluation and clinical significance of the stomach <span class="hlt">age</span> <span class="hlt">model</span> for evaluating <span class="hlt">aging</span> of the stomach-a multicenter study in China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background A higher prevalence of chronic atrophic gastritis (CAG) occurs in younger adults in Asia. We used Stomach <span class="hlt">Age</span> to examine the different mechanisms of CAG between younger adults and elderly individuals, and established a simple <span class="hlt">model</span> of cancer risk that can be applied to CAG surveillance. Methods Stomach <span class="hlt">Age</span> was determined by FISH examination of telomere length in stomach biopsies. Δψm was also determined by flow cytometry. Sixty volunteers were used to confirm the linear relationship between telomere length and <span class="hlt">age</span> while 120 subjects were used to build a mathematical <span class="hlt">model</span> by a multivariate analysis. Overall, 146 subjects were used to evaluate the validity of the <span class="hlt">model</span>, and 1,007 subjects were used to evaluate the relationship between prognosis and Δ<span class="hlt">age</span> (calculated from the mathematical <span class="hlt">model</span>). ROC curves were used to evaluate the relationship between prognosis and Δ<span class="hlt">age</span> and to determine the cut-off point for Δ<span class="hlt">age</span>. Results We established that a tight linear relationship between the telomere length and the <span class="hlt">age</span>. The telomere length was obvious different between patients with and without CAG even in the same <span class="hlt">age</span>. Δψm decreased in individuals whose Stomach <span class="hlt">Age</span> was greater than real <span class="hlt">age</span>, especially in younger adults. A mathematical <span class="hlt">model</span> of Stomach <span class="hlt">Age</span> (real age + Δ<span class="hlt">age</span>) was successfully constructed which was easy to apply in clinical work. A higher Δ<span class="hlt">age</span> was correlated with a worse outcome. The criterion of Δ<span class="hlt">age</span> >3.11 should be considered as the cut-off to select the subgroup of patients who require endoscopic surveillance. Conclusion Variation in Stomach <span class="hlt">Age</span> between individuals of the same biological <span class="hlt">age</span> was confirmed. Attention should be paid to those with a greater Stomach <span class="hlt">Age</span>, especially in younger adults. The Δ<span class="hlt">age</span> in the Simple <span class="hlt">Model</span> can be used as a criterion to select CAG patients for gastric cancer surveillance. PMID:25057261</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1867306','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1867306"><span id="translatedtitle">Progressive <span class="hlt">Age</span>-Related Changes Similar to <span class="hlt">Age</span>-Related Macular Degeneration in a Transgenic Mouse <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rakoczy, Piroska Elizabeth; Zhang, Dan; Robertson, Terry; Barnett, Nigel L.; Papadimitriou, John; Constable, Ian Jeffrey; Lai, Chooi-May</p> <p>2002-01-01</p> <p><span class="hlt">Age</span>-related macular degeneration (AMD) is the major cause of blindness in the developed world. Its pathomechanism is unknown and its late onset, complex genetics and strong environmental components have all hampered investigations. Here we demonstrate the development of an animal <span class="hlt">model</span> for AMD that reproduces features associated with geographic atrophy; a transgenic mouse line (mcd/mcd) expressing a mutated form of cathepsin D that is enzymatically inactive thus impairing processing of phagocytosed photoreceptor outer segments in the retinal pigment epithelial (RPE) cells. Pigmentary changes indicating RPE cell atrophy and a decreased response to flash electroretinograms were observed in 11- to 12-month-old mcd/mcd mice. Histological studies showed RPE cell proliferation, photoreceptor degeneration, shortening of photoreceptor outer segments, and accumulation of immunoreactive photoreceptor breakdown products in the RPE cells. An accelerated photoreceptor cell death was detected in 12-month-old mcd/mcd mice. Transmission electron microscopy demonstrated presence of basal laminar and linear deposits that are considered to be the hallmarks of AMD. Small hard drusen associated with human <span class="hlt">age</span>-related maculopathy were absent in the mcd/mcd mouse <span class="hlt">model</span> at the <span class="hlt">ages</span> analyzed. In summary, this <span class="hlt">model</span> presents several features of AMD, thus providing a valuable tool for investigating the underlying biological processes and pathomechanism of AMD. PMID:12368224</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AAS...210.8602L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AAS...210.8602L"><span id="translatedtitle">Improving HST Pointing & <span class="hlt">Absolute</span> Astrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lallo, Matthew; Nelan, E.; Kimmer, E.; Cox, C.; Casertano, S.</p> <p>2007-05-01</p> <p>Accurate <span class="hlt">absolute</span> astrometry is becoming increasingly important in an era of multi-mission archives and virtual observatories. Hubble Space Telescope's (HST's) Guidestar Catalog II (GSC2) has reduced coordinate error to around 0.25 arcsecond, a factor 2 or more compared with GSC1. With this reduced catalog error, special attention must be given to calibrate and maintain the Fine Guidance Sensors (FGSs) and Science Instruments (SIs) alignments in HST to a level well below this in order to ensure that the accuracy of science product's astrometry keywords and target positioning are limited only by the catalog errors. After HST Servicing Mission 4, such calibrations' improvement in "blind" pointing accuracy will allow for more efficient COS acquisitions. Multiple SIs and FGSs each have their own footprints in the spatially shared HST focal plane. It is the small changes over time in primarily the whole-body positions & orientations of these instruments & guiders relative to one another that is addressed by this work. We describe the HST Cycle 15 program CAL/OTA 11021 which, along with future variants of it, determines and maintains positions and orientations of the SIs and FGSs to better than 50 milli- arcseconds and 0.04 to 0.004 degrees of roll, putting errors associated with the alignment sufficiently below GSC2 errors. We present recent alignment results and assess their errors, illustrate trends, and describe where and how the observer sees benefit from these calibrations when using HST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/3777908','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/3777908"><span id="translatedtitle"><span class="hlt">Absolute</span> oral bioavailability of ciprofloxacin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Drusano, G L; Standiford, H C; Plaisance, K; Forrest, A; Leslie, J; Caldwell, J</p> <p>1986-09-01</p> <p>We evaluated the <span class="hlt">absolute</span> bioavailability of ciprofloxacin, a new quinoline carboxylic acid, in 12 healthy male volunteers. Doses of 200 mg were given to each of the volunteers in a randomized, crossover manner 1 week apart orally and as a 10-min intravenous infusion. Half-lives (mean +/- standard deviation) for the intravenous and oral administration arms were 4.2 +/- 0.77 and 4.11 +/- 0.74 h, respectively. The serum clearance rate averaged 28.5 +/- 4.7 liters/h per 1.73 m2 for the intravenous administration arm. The renal clearance rate accounted for approximately 60% of the corresponding serum clearance rate and was 16.9 +/- 3.0 liters/h per 1.73 m2 for the intravenous arm and 17.0 +/- 2.86 liters/h per 1.73 m2 for the oral administration arm. Absorption was rapid, with peak concentrations in serum occurring at 0.71 +/- 0.15 h. Bioavailability, defined as the ratio of the area under the curve from 0 h to infinity for the oral to the intravenous dose, was 69 +/- 7%. We conclude that ciprofloxacin is rapidly absorbed and reliably bioavailable in these healthy volunteers. Further studies with ciprofloxacin should be undertaken in target patient populations under actual clinical circumstances. PMID:3777908</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPJO6008H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPJO6008H"><span id="translatedtitle"><span class="hlt">Absolute</span> Instability in Coupled-Cavity TWTs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hung, D. M. H.; Rittersdorf, I. M.; Zhang, Peng; Lau, Y. Y.; Simon, D. H.; Gilgenbach, R. M.; Chernin, D.; Antonsen, T. M., Jr.</p> <p>2014-10-01</p> <p>This paper will present results of our analysis of <span class="hlt">absolute</span> instability in a coupled-cavity traveling wave tube (TWT). The structure mode at the lower and upper band edges are respectively approximated by a hyperbola in the (omega, k) plane. When the Briggs-Bers criterion is applied, a threshold current for onset of <span class="hlt">absolute</span> instability is observed at the upper band edge, but not the lower band edge. The nonexistence of <span class="hlt">absolute</span> instability at the lower band edge is mathematically similar to the nonexistence of <span class="hlt">absolute</span> instability that we recently demonstrated for a dielectric TWT. The existence of <span class="hlt">absolute</span> instability at the upper band edge is mathematically similar to the existence of <span class="hlt">absolute</span> instability in a gyroton traveling wave amplifier. These interesting observations will be discussed, and the practical implications will be explored. This work was supported by AFOSR, ONR, and L-3 Communications Electron Devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhRvE..75b7301G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhRvE..75b7301G"><span id="translatedtitle"><span class="hlt">Absolute</span> instability of a viscous hollow jet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gañán-Calvo, Alfonso M.</p> <p>2007-02-01</p> <p>An investigation of the spatiotemporal stability of hollow jets in unbounded coflowing liquids, using a general dispersion relation previously derived, shows them to be <span class="hlt">absolutely</span> unstable for all physical values of the Reynolds and Weber numbers. The roots of the symmetry breakdown with respect to the liquid jet case, and the validity of asymptotic <span class="hlt">models</span> are here studied in detail. Asymptotic analyses for low and high Reynolds numbers are provided, showing that old and well-established limiting dispersion relations [J. W. S. Rayleigh, The Theory of Sound (Dover, New York, 1945); S. Chandrasekhar, Hydrodynamic and Hydromagnetic Stability (Dover, New York, 1961)] should be used with caution. In the creeping flow limit, the analysis shows that, if the hollow jet is filled with any finite density and viscosity fluid, a steady jet could be made arbitrarily small (compatible with the continuum hypothesis) if the coflowing liquid moves faster than a critical velocity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26328769','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26328769"><span id="translatedtitle">A statistical <span class="hlt">model</span> including <span class="hlt">age</span> to predict passenger postures in the rear seats of automobiles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Jangwoon; Ebert, Sheila M; Reed, Matthew P; Hallman, Jason J</p> <p>2016-06-01</p> <p>Few statistical <span class="hlt">models</span> of rear seat passenger posture have been published, and none has taken into account the effects of occupant <span class="hlt">age</span>. This study developed new statistical <span class="hlt">models</span> for predicting passenger postures in the rear seats of automobiles. Postures of 89 adults with a wide range of <span class="hlt">age</span> and body size were measured in a laboratory mock-up in seven seat configurations. Posture-prediction <span class="hlt">models</span> for female and male passengers were separately developed by stepwise regression using <span class="hlt">age</span>, body dimensions, seat configurations and two-way interactions as potential predictors. Passenger posture was significantly associated with <span class="hlt">age</span> and the effects of other two-way interaction variables depended on <span class="hlt">age</span>. A set of posture-prediction <span class="hlt">models</span> are presented for women and men, and the prediction results are compared with previously published <span class="hlt">models</span>. This study is the first study of passenger posture to include a large cohort of older passengers and the first to report a significant effect of <span class="hlt">age</span> for adults. The presented <span class="hlt">models</span> can be used to position computational and physical human <span class="hlt">models</span> for vehicle design and assessment. Practitioner Summary: The significant effects of <span class="hlt">age</span>, body dimensions and seat configuration on rear seat passenger posture were identified. The <span class="hlt">models</span> can be used to accurately position computational human <span class="hlt">models</span> or crash test dummies for older passengers in known rear seat configurations. PMID:26328769</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70012502','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70012502"><span id="translatedtitle"><span class="hlt">Aging</span> and strain softening <span class="hlt">model</span> for episodic faulting</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stuart, W.D.</p> <p>1979-01-01</p> <p>Episodic slip on shallow crustal faults can be qualitatively explained by postulating a fault constitutive law that is the superposition of two limiting material responses: (1) strain softening after peak stress during large strain rates, and (2) strength (peak stress) recovery during <span class="hlt">aging</span> at small strain rates. A single law permits a variety of seismic and aseismic phenomena to occur over a range of space and time scales. Specific cases are determined by the spatial variation of material constants, recent deformation history, crustal rigidity, and remote forcing. ?? 1979.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23686614','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23686614"><span id="translatedtitle">Population-based <span class="hlt">absolute</span> risk estimation with survey data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kovalchik, Stephanie A; Pfeiffer, Ruth M</p> <p>2014-04-01</p> <p><span class="hlt">Absolute</span> risk is the probability that a cause-specific event occurs in a given time interval in the presence of competing events. We present methods to estimate population-based <span class="hlt">absolute</span> risk from a complex survey cohort that can accommodate multiple exposure-specific competing risks. The hazard function for each event type consists of an individualized relative risk multiplied by a baseline hazard function, which is <span class="hlt">modeled</span> nonparametrically or parametrically with a piecewise exponential <span class="hlt">model</span>. An influence method is used to derive a Taylor-linearized variance estimate for the <span class="hlt">absolute</span> risk estimates. We introduce novel measures of the cause-specific influences that can guide <span class="hlt">modeling</span> choices for the competing event components of the <span class="hlt">model</span>. To illustrate our methodology, we build and validate cause-specific <span class="hlt">absolute</span> risk <span class="hlt">models</span> for cardiovascular and cancer deaths using data from the National Health and Nutrition Examination Survey. Our applications demonstrate the usefulness of survey-based risk prediction <span class="hlt">models</span> for predicting health outcomes and quantifying the potential impact of disease prevention programs at the population level. PMID:23686614</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyA..439....1O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyA..439....1O"><span id="translatedtitle"><span class="hlt">Absolute</span> negative mobility of interacting Brownian particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ou, Ya-li; Hu, Cai-tian; Wu, Jian-chun; Ai, Bao-quan</p> <p>2015-12-01</p> <p>Transport of interacting Brownian particles in a periodic potential is investigated in the presence of an ac force and a dc force. From Brownian dynamic simulations, we find that both the interaction between particles and the thermal fluctuations play key roles in the <span class="hlt">absolute</span> negative mobility (the particle noisily moves backwards against a small constant bias). When no the interaction acts, there is only one region where the <span class="hlt">absolute</span> negative mobility occurs. In the presence of the interaction, the <span class="hlt">absolute</span> negative mobility may appear in multiple regions. The weak interaction can be helpful for the <span class="hlt">absolute</span> negative mobility, while the strong interaction has a destructive impact on it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4768636','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4768636"><span id="translatedtitle">Oxidative Damage in the <span class="hlt">Aging</span> Heart: an Experimental Rat <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Marques, Gustavo Lenci; Neto, Francisco Filipak; Ribeiro, Ciro Alberto de Oliveira; Liebel, Samuel; de Fraga, Rogério; Bueno, Ronaldo da Rocha Loures</p> <p>2015-01-01</p> <p>Introduction: Several theories have been proposed to explain the cause of ‘aging’; however, the factors that affect this complex process are still poorly understood. Of these theories, the accumulation of oxidative damage over time is among the most accepted. Particularly, the heart is one of the most affected organs by oxidative stress. The current study, therefore, aimed to investigate oxidative stress markers in myocardial tissue of rats at different <span class="hlt">ages</span>. Methods: Seventy-two rats were distributed into 6 groups of 12 animals each and maintained for 3, 6, 9, 12, 18 and 24 months. After euthanasia, the heart was removed and the levels of non-protein thiols, lipid peroxidation, and protein carbonylation, as well as superoxide dismutase and catalase activities were determined. Results: Superoxide dismutase, catalase activity and lipid peroxidation were reduced in the older groups of animals, when compared with the younger group. However, protein carbonylation showed an increase in the 12-month group followed by a decrease in the older groups. In addition, the levels of non-protein thiols were increased in the 12-month group and not detected in the older groups. Conclusion: Our data showed that oxidative stress is not associated with <span class="hlt">aging</span> in the heart. However, an increase in non-protein thiols may be an important factor that compensates for the decrease of superoxide dismutase and catalase activity in the oldest rats, to maintain appropriate antioxidant defenses against oxidative insults. PMID:27006709</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.418...66W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.418...66W"><span id="translatedtitle"><span class="hlt">Absolute</span> plate motions since 130 Ma constrained by subduction zone kinematics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, Simon; Flament, Nicolas; Dietmar Müller, R.; Butterworth, Nathaniel</p> <p>2015-05-01</p> <p>The <span class="hlt">absolute</span> motions of the lithospheric plates relative to the Earth's deep interior are commonly constrained using observations from paleomagnetism and <span class="hlt">age</span>-progressive seamount trails. In contrast, an <span class="hlt">absolute</span> plate motion (APM) <span class="hlt">model</span> linking surface plate motions to subducted slab remnants mapped from seismic tomography has recently been proposed. <span class="hlt">Absolute</span> plate motion <span class="hlt">models</span> (or "reference frames") derived using different methodologies, different subsets of hotspots, or differing assumptions of hotspot motion, have contrasting implications for parameters that describe the long term state of the plate-mantle system, such as the balance between advance and retreat of subduction zones, plate velocities, and net lithospheric rotation. Previous studies of contemporary plate motions have used subduction zone kinematics as a constraint on the most likely APM <span class="hlt">model</span>. Here we use a relative plate motion <span class="hlt">model</span> to compute these values for the last 130 Myr for a range of alternative reference frames, and quantitatively compare the results. We find that hotspot and tomographic slab-remnant reference frames yield similar results for the last 70 Myr. For the 130-70 Ma period, where hotspot reference frames are less well constrained, these <span class="hlt">models</span> yield a much more dispersed distribution of slab advance and retreat velocities. By contrast, plate motions calculated using the slab-remnant reference frame, or using a reference frame designed to minimise net rotation, yield more consistent subduction zone kinematics for times older than 70 Ma. Introducing the global optimisation of trench migration characteristics as a key criterion in the construction of APM <span class="hlt">models</span> forms the foundation of a new method of constraining APMs (and in particular paleolongitude) in deep geological time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003APS..MAR.Z9014A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003APS..MAR.Z9014A"><span id="translatedtitle">Stochastic Process <span class="hlt">Model</span> of Physiological Regeneration, Fertility and <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akushevich, Igor; Manton, Kenneth</p> <p>2003-03-01</p> <p>A state space <span class="hlt">model</span> of human birth, death processes is presented based upon a generalization of the Fokker-Planck-Kolmogorov (F-P-K) diffusion equation. In the <span class="hlt">model</span> it is assumed that males and females are linked through the birth process and that birth and fetal growth, itself possibly described by a F-P-K equation, generates new probability mass in the population state space. Specific case of radiation as a risk factor is considered and analyzed. Life time generator is constructed on the basis of the developed <span class="hlt">model</span> and its results are compared with existent physiological longitudinal data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...817..164R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...817..164R"><span id="translatedtitle">Dynamical Masses of Young Stars. I. Discordant <span class="hlt">Model</span> <span class="hlt">Ages</span> of Upper Scorpius</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rizzuto, Aaron C.; Ireland, Michael J.; Dupuy, Trent J.; Kraus, Adam L.</p> <p>2016-02-01</p> <p>We present the results of a long-term orbit monitoring program, using sparse aperture masking observations taken with NIRC2 on the Keck-II telescope, of seven G- to M-type members of the Upper Scorpius subgroup of the Sco-Cen OB association. We present astrometry and derived orbital elements of the binary systems we have monitored, and also determine the <span class="hlt">age</span>, component masses, distance, and reddening for each system using the orbital solutions and multi-band photometry, including Hubble Space Telescope photometry, and a Bayesian fitting procedure. We find that the <span class="hlt">models</span> can be forced into agreement with any individual system by assuming an <span class="hlt">age</span>, but that <span class="hlt">age</span> is not consistent across the mass range of our sample. The G-type binary systems in our sample have <span class="hlt">model</span> <span class="hlt">ages</span> of ˜11.5 Myr, which is consistent with the latest <span class="hlt">age</span> estimates for Upper Scorpius, while the M-type binary systems have significantly younger <span class="hlt">model</span> <span class="hlt">ages</span> of ˜7 Myr. Based on our fits, this <span class="hlt">age</span> discrepancy in the <span class="hlt">models</span> corresponds to a luminosity underprediction of 0.8-0.15 dex, or equivalently an effective temperature overprediction of 100-300 K for M-type stars at a given pre-main-sequence <span class="hlt">age</span>. We also find that the M-type binary system RXJ 1550.0-2312 has an <span class="hlt">age</span> (˜16 Myr) and distance (˜85 pc) consistent with membership in the Upper Centaurus Lupus subgroup.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25840344','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25840344"><span id="translatedtitle">In vitro 3-D <span class="hlt">model</span> based on extending time of culture for studying chronological epidermis <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dos Santos, Morgan; Metral, Elodie; Boher, Aurélie; Rousselle, Patricia; Thepot, Amélie; Damour, Odile</p> <p>2015-09-01</p> <p>Skin <span class="hlt">aging</span> is a complex phenomenon in which several mechanisms operate simultaneously. Among them, intrinsic <span class="hlt">aging</span> is a time-dependent process, which leads to gradual skin changes affecting its structure and function such as thinning down of both epidermal and dermal compartments and a flattening and fragility of the dermo-epidermal junction. Today, several approaches have been proposed for the generation of <span class="hlt">aged</span> skin in vitro, including skin explants from <span class="hlt">aged</span> donors and three-dimensional skin equivalent treated by <span class="hlt">aging</span>-inducing chemical compounds or engineered with human cells isolated from <span class="hlt">aged</span> donors. The aim of this study was to develop and validate a new in vitro <span class="hlt">model</span> of <span class="hlt">aging</span> based on skin equivalent demonstrating the same phenotypic changes that were observed in chronological <span class="hlt">aging</span>. By using prolonged culture as a proxy for cellular <span class="hlt">aging</span>, we extended to 120 days the culture time of a skin equivalent <span class="hlt">model</span> based on collagen-glycosaminoglycan-chitosan porous polymer and engineered with human skin cells from photo-protected sites of young donors. Morphological, immunohistological and ultrastructural analysis at different time points of the culture allowed characterizing the phenotypic changes observed in our <span class="hlt">model</span> in comparison to samples of non photo-exposed normal human skin from different <span class="hlt">ages</span>. We firstly confirmed that long-term cultured skin equivalents are still morphologically consistent and functionally active even after 120 days of culture. However, similar to in vivo chronological skin <span class="hlt">aging</span> a significant decrease of the epidermis thickness as well as the number of keratinocyte expressing proliferation marker Ki67 are observed in extended culture time skin equivalent. Epidermal differentiation markers loricrin, filaggrin, involucrin and transglutaminase, also strongly decreased. Ultrastructural analysis of basement membrane showed typical features of <span class="hlt">aged</span> skin such as duplication of lamina densa and alterations of hemidesmosomes. Moreover, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22340220','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22340220"><span id="translatedtitle"><span class="hlt">Absolute</span> properties of the eclipsing binary star AP Andromedae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sandberg Lacy, Claud H.; Torres, Guillermo; Fekel, Francis C.; Muterspaugh, Matthew W. E-mail: gtorres@cfa.harvard.edu E-mail: matthew1@coe.tsuniv.edu</p> <p>2014-06-01</p> <p>AP And is a well-detached F5 eclipsing binary star for which only a very limited amount of information was available before this publication. We have obtained very extensive measurements of the light curve (19,097 differential V magnitude observations) and a radial velocity curve (83 spectroscopic observations) which allow us to fit orbits and determine the <span class="hlt">absolute</span> properties of the components very accurately: masses of 1.277 ± 0.004 and 1.251 ± 0.004 M {sub ☉}, radii of 1.233 ± 0.006 and 1.1953 ± 0.005 R {sub ☉}, and temperatures of 6565 ± 150 K and 6495 ± 150 K. The distance to the system is about 400 ± 30 pc. Comparison with the theoretical properties of the stellar evolutionary <span class="hlt">models</span> of the Yonsei-Yale series of Yi et al. shows good agreement between the observations and the theory at an <span class="hlt">age</span> of about 500 Myr and a slightly sub-solar metallicity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22034456','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22034456"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> PROPERTIES OF THE ECLIPSING BINARY STAR BF DRACONIS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sandberg Lacy, Claud H.; Torres, Guillermo; Fekel, Francis C.; Sabby, Jeffrey A.; Claret, Antonio E-mail: gtorres@cfa.harvard.edu E-mail: jsabby@siue.edu</p> <p>2012-06-15</p> <p>BF Dra is now known to be an eccentric double-lined F6+F6 binary star with relatively deep (0.7 mag) partial eclipses. Previous studies of the system are improved with 7494 differential photometric observations from the URSA WebScope and 9700 from the NFO WebScope, 106 high-resolution spectroscopic observations from the Tennessee State University 2 m automatic spectroscopic telescope and the 1 m coude-feed spectrometer at Kitt Peak National Observatory, and 31 accurate radial velocities from the CfA. Very accurate (better than 0.6%) masses and radii are determined from analysis of the two new light curves and four radial velocity curves. Theoretical <span class="hlt">models</span> match the <span class="hlt">absolute</span> properties of the stars at an <span class="hlt">age</span> of about 2.72 Gyr and [Fe/H] = -0.17, and tidal theory correctly confirms that the orbit should still be eccentric. Our observations of BF Dra constrain the convective core overshooting parameter to be larger than about 0.13 H{sub p}. We find, however, that standard tidal theory is unable to match the observed slow rotation rates of the components' surface layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4835678','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4835678"><span id="translatedtitle">Mathematical <span class="hlt">Model</span> of Three <span class="hlt">Age</span>-Structured Transmission Dynamics of Chikungunya Virus</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Agusto, Folashade B.; Easley, Shamise; Freeman, Kenneth; Thomas, Madison</p> <p>2016-01-01</p> <p>We developed a new <span class="hlt">age</span>-structured deterministic <span class="hlt">model</span> for the transmission dynamics of chikungunya virus. The <span class="hlt">model</span> is analyzed to gain insights into the qualitative features of its associated equilibria. Some of the theoretical and epidemiological findings indicate that the stable disease-free equilibrium is globally asymptotically stable when the associated reproduction number is less than unity. Furthermore, the <span class="hlt">model</span> undergoes, in the presence of disease induced mortality, the phenomenon of backward bifurcation, where the stable disease-free equilibrium of the <span class="hlt">model</span> coexists with a stable endemic equilibrium when the associated reproduction number is less than unity. Further analysis of the <span class="hlt">model</span> indicates that the qualitative dynamics of the <span class="hlt">model</span> are not altered by the inclusion of <span class="hlt">age</span> structure. This is further emphasized by the sensitivity analysis results, which shows that the dominant parameters of the <span class="hlt">model</span> are not altered by the inclusion of <span class="hlt">age</span> structure. However, the numerical simulations show the flaw of the exclusion of <span class="hlt">age</span> in the transmission dynamics of chikungunya with regard to control implementations. The exclusion of <span class="hlt">age</span> structure fails to show the <span class="hlt">age</span> distribution needed for an effective <span class="hlt">age</span> based control strategy, leading to a one size fits all blanket control for the entire population. PMID:27190548</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRD..118.2304M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRD..118.2304M"><span id="translatedtitle">Development and validation of a black carbon mixing state resolved three-dimensional <span class="hlt">model</span>: <span class="hlt">Aging</span> processes and radiative impact</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsui, H.; Koike, M.; Kondo, Y.; Moteki, N.; Fast, J. D.; Zaveri, R. A.</p> <p>2013-03-01</p> <p>A new two-dimensional aerosol bin scheme, which resolves both aerosol size and black carbon (BC) mixing state for BC <span class="hlt">aging</span> processes (e.g., condensation and coagulation) with 12 size × 10 mixing state bins, has been developed and implemented into the WRF-chem <span class="hlt">model</span> (MS-resolved WRF-chem). The mixing state of BC simulated by this <span class="hlt">model</span> is compared with direct measurements over the East Asian region in spring 2009. <span class="hlt">Model</span> simulations generally reproduce the observed features of the BC mixing state, such as the size-dependent number fractions of BC-containing and BC-free particles and the coating thickness of BC-containing particles. This result shows that the <span class="hlt">model</span> can simulate realistic BC mixing states in the atmosphere if condensation and coagulation processes are calculated explicitly with the detailed treatment of BC mixing state. Sensitivity simulations show that the condensation process is dominant for the growth of thinly coated BC particles, while the coagulation process is necessary to produce thickly coated BC particles. Off-line optical and radiative calculations assuming an average mixing state for each size bin show that the domain- and period-averaged absorption coefficient and heating rate by aerosols are overestimated by 30-40% in the boundary layer, compared with a benchmark simulation with the detailed treatment of mixing state. The <span class="hlt">absolute</span> value of aerosol radiative forcing is also overestimated (10%, 3 W m-2) at the surface. However, these overestimations are reduced considerably when all the parameters (including mass and number concentration) are calculated with the simple treatment of mixing state. This is because the overestimation of radiative parameters due to higher absorption efficiency (compared with the benchmark simulation) is largely canceled by the underestimation of BC concentrations due to efficient wet removal processes. The overall errors in radiative forcing can be much smaller because of this cancellation, but for the wrong</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21826153','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21826153"><span id="translatedtitle">Molecular mechanisms and in vivo mouse <span class="hlt">models</span> of skin <span class="hlt">aging</span> associated with dermal matrix alterations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hwang, Kyung-A; Yi, Bo-Rim; Choi, Kyung-Chul</p> <p>2011-03-01</p> <p>Skin is the most superficial body organ and plays an important role in protecting the body from environmental damage and in forming social relations. With the increase of the <span class="hlt">aging</span> population in our society, dermatological and cosmetic concerns of skin <span class="hlt">aging</span> are rapidly increasing. Skin <span class="hlt">aging</span> is a complex process combined with intrinsic and extrinsic factors. Intrinsic or chronological skin <span class="hlt">aging</span> results from the passage of time and is influenced by genetic factors. Extrinsic skin <span class="hlt">aging</span> is mainly determined by UV irradiation, also called photoaging. These two types of <span class="hlt">aging</span> processes are superimposed on sun-exposed skin, and have a common feature of causing dermal matrix alterations that mostly contribute to the formation of wrinkles, laxity, and fragility of <span class="hlt">aged</span> skin. The dermal matrix contains extracellular matrix proteins such as collagen, elastin, and proteoglycans that confer the strength and resiliency of skin. Skin <span class="hlt">aging</span> associated with dermal matrix alterations and atrophy can be caused by cellular senescence of dermal cells like fibroblasts, and decreased synthesis and accelerated degradation of dermal matrix components, especially collagen fibers. Both intrinsic <span class="hlt">aging</span> and photoaging exert influence during each step of dermal matrix alteration via different mechanisms. Mouse <span class="hlt">models</span> of skin <span class="hlt">aging</span> have been extensively developed to elucidate intrinsic <span class="hlt">aging</span> and photoaging processes, to validate in vitro biochemical data, and to test the effects of pharmacological tools for retarding skin <span class="hlt">aging</span> because they have the advantages of being genetically similar to humans and are easily available. PMID:21826153</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2934899','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2934899"><span id="translatedtitle">GPU-Accelerated Molecular <span class="hlt">Modeling</span> Coming Of <span class="hlt">Age</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stone, John E.; Hardy, David J.; Ufimtsev, Ivan S.</p> <p>2010-01-01</p> <p>Graphics processing units (GPUs) have traditionally been used in molecular <span class="hlt">modeling</span> solely for visualization of molecular structures and animation of trajectories resulting from molecular dynamics simulations. Modern GPUs have evolved into fully programmable, massively parallel co-processors that can now be exploited to accelerate many scientific computations, typically providing about one order of magnitude speedup over CPU code and in special cases providing speedups of two orders of magnitude. This paper surveys the development of molecular <span class="hlt">modeling</span> algorithms that leverage GPU computing, the advances already made and remaining issues to be resolved, and the continuing evolution of GPU technology that promises to become even more useful to molecular <span class="hlt">modeling</span>. Hardware acceleration with commodity GPUs is expected to benefit the overall computational biology community by bringing teraflops performance to desktop workstations and in some cases potentially changing what were formerly batch-mode computational jobs into interactive tasks. PMID:20675161</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGP41B1117M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGP41B1117M"><span id="translatedtitle">Direct comparisons between <span class="hlt">absolute</span> and relative geomagnetic paleointensities: <span class="hlt">Absolute</span> calibration of a relative paleointensity stack</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mochizuki, N.; Yamamoto, Y.; Hatakeyama, T.; Shibuya, H.</p> <p>2013-12-01</p> <p><span class="hlt">Absolute</span> geomagnetic paleointensities (APIs) have been estimated from igneous rocks, while relative paleomagnetic intensities (RPIs) have been reported from sediment cores. These two datasets have been treated separately, as correlations between APIs and RPIs are difficult on account of <span class="hlt">age</span> uncertainties. High-resolution RPI stacks have been constructed from globally distributed sediment cores with high sedimentation rates. Previous studies often assumed that the RPI stacks have a linear relationship with geomagnetic axial dipole moments, and calibrated the RPI values to API values. However, the assumption of a linear relationship between APIs and RPIs has not been evaluated. Also, a quantitative calibration method for the RPI is lacking. We present a procedure for directly comparing API and RPI stacks, thus allowing reliable calibrations of RPIs. Direct comparisons between APIs and RPIs were conducted with virtually no associated <span class="hlt">age</span> errors using both tephrochronologic correlations and RPI minima. Using the stratigraphic positions of tephra layers in oxygen isotope stratigraphic records, we directly compared the RPIs and APIs reported from welded tuffs contemporaneously extruded with the tephra layers. In addition, RPI minima during geomagnetic reversals and excursions were compared with APIs corresponding to the reversals and excursions. The comparison of APIs and RPIs at these exact points allowed a reliable calibration of the RPI values. We applied this direct comparison procedure to the global RPI stack PISO-1500. For six independent calibration points, virtual axial dipole moments (VADMs) from the corresponding APIs and RPIs of the PISO-1500 stack showed a near-linear relationship. On the basis of the linear relationship, RPIs of the stack were successfully calibrated to the VADMs. The direct comparison procedure provides an <span class="hlt">absolute</span> calibration method that will contribute to the recovery of temporal variations and distributions of geomagnetic axial dipole</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060044287&hterms=metrology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmetrology','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060044287&hterms=metrology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmetrology"><span id="translatedtitle"><span class="hlt">Absolute</span> optical metrology : nanometers to kilometers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.</p> <p>2005-01-01</p> <p>We provide and overview of the developments in the field of high-accuracy <span class="hlt">absolute</span> optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for <span class="hlt">Absolute</span> Ranging (MSTAR) sensor is described along with novel applications of the sensor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1261596','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1261596"><span id="translatedtitle">Monolithically integrated <span class="hlt">absolute</span> frequency comb laser system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wanke, Michael C.</p> <p>2016-07-12</p> <p>Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an <span class="hlt">absolute</span> frequency without the need of a frequency-comb synthesizer. The monolithic, <span class="hlt">absolute</span> frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&pg=2&id=EJ1050985','ERIC'); return false;" href="http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&pg=2&id=EJ1050985"><span id="translatedtitle">Introducing the Mean <span class="hlt">Absolute</span> Deviation "Effect" Size</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gorard, Stephen</p> <p>2015-01-01</p> <p>This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean <span class="hlt">absolute</span> deviation as a measure of variation, as opposed to the more complex standard deviation. The mean <span class="hlt">absolute</span> deviation is easier to use and understand, and more tolerant of extreme…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ853800.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ853800.pdf"><span id="translatedtitle">Investigating <span class="hlt">Absolute</span> Value: A Real World Application</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kidd, Margaret; Pagni, David</p> <p>2009-01-01</p> <p>Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of <span class="hlt">absolute</span> values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that <span class="hlt">absolute</span> value simply…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=happiness&pg=7&id=EJ804151','ERIC'); return false;" href="http://eric.ed.gov/?q=happiness&pg=7&id=EJ804151"><span id="translatedtitle"><span class="hlt">Absolute</span> Income, Relative Income, and Happiness</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ball, Richard; Chernova, Kateryna</p> <p>2008-01-01</p> <p>This paper uses data from the World Values Survey to investigate how an individual's self-reported happiness is related to (i) the level of her income in <span class="hlt">absolute</span> terms, and (ii) the level of her income relative to other people in her country. The main findings are that (i) both <span class="hlt">absolute</span> and relative income are positively and significantly…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED217360.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED217360.pdf"><span id="translatedtitle"><span class="hlt">Aging</span> and Interdependence: A Theoretical <span class="hlt">Model</span> for Close Relationships.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Blieszner, Rosemary</p> <p></p> <p>This paper demonstrates the utility of interdependence theory for understanding older persons' social relationships. Using friendship as an exemplary case, a <span class="hlt">model</span> of expectations for and reactions to social exchanges is described. Exchanges which are perceived to be motivated by obligation are distinguished from those which are perceived to…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998APS..DFD..JF05D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998APS..DFD..JF05D"><span id="translatedtitle"><span class="hlt">Absolute</span> and Convective Instability in Fluid-Conveying Flexible Pipes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Langre, E.; Ouvrard, A. E.</p> <p>1998-11-01</p> <p>The effect of internal plug flow on the lateral stability of fluid conveying flexible pipes is investigated by determining the <span class="hlt">absolute</span>/convective nature of the instability from the analytically derived linear dispersion relation. The fluid-structure interaction is <span class="hlt">modeled</span> following the work of Gregory and Paidoussis (1966). The different domains of stability, convective instability, and <span class="hlt">absolute</span> instability are explicitly derived in parameter space. The effect of flow velocity, mass ratio between the fluid and the structure, stiffness of the elastic foundation and axial tension is considered. <span class="hlt">Absolute</span> instability prevails over a wide range of parameters. Convective instability only takes place at very high mass ratio, small stiffness and small axial tension. Relation is made with previous work of Brazier-Smith & Scott (1984) and Crighton (1991), considered here as a short wave approximation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10158171','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10158171"><span id="translatedtitle">In vivo animal <span class="hlt">models</span> of body composition in <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yasumura, S. |; Jones, K.; Spanne, P.; Schidlovsky, G.; Wielopolski, L.; Ren, X.; Glaros, D.; Xatzikonstantinou, Y. |</p> <p>1992-12-31</p> <p>We developed several techniques that provide data on body elemental composition from in vivo measurements in rats. These methods include total body potassium by whole-body counting of endogenous {sup 40}K; total body calcium (TBCa), sodium and chloride by in vivo neutron activation analysis and total body phosphorus (TBP) and nitrogen (TBN) by photon activation analysis. These elements provide information on total body fat, total body protein and skeletal mass. Measurements were made in 6-, 12- and 24-month-old rats. TBN Increased slightly between 6 and 12 months but was significantly lower by 24 months, indicating a substantial loss in total body protein. Working at the National Synchrotron light Source, we studied rat femurs by computed microtomography (CMT), and the elemental profile of the femur cortex by synchrotron-radiation induced X-ray emission (SRIXE). Although there were no significant changes in TBCA and TBP, indices of skeletal mass, CMT revealed a marked increase in the size and number of cavities in the endosteal region of the femur cortex with increasing <span class="hlt">age</span>. The SRIXE analysis of this cortical bone revealed a parallel decrease in the endosteal Ca/P ratio. Thus, there are major alterations in bone morphology and regional elemental composition despite only modest changes in total skeletal mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020080815','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020080815"><span id="translatedtitle">A Comparison of the <span class="hlt">Age</span>-Spectra from Data Assimilation <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schoeberl, Mark R.; Douglass, Anne R.; Zhu, Zheng-Xin; Pawson, Steven; Einaudi, Franco (Technical Monitor)</p> <p>2002-01-01</p> <p>We use kinematic and diabatic back trajectory calculations, driven by winds from a general circulation <span class="hlt">model</span> (GCM) and two different data assimilation systems (DAS), to compute the <span class="hlt">age</span> spectrum at three latitudes in the lower stratosphere. The <span class="hlt">age</span>-spectra are compared to chemical transport <span class="hlt">model</span> (CTM) calculations, and the mean <span class="hlt">ages</span> from all of these studies are compared to observations. The <span class="hlt">age</span> spectra computed using the GCM winds show a reasonably well-isolated tropics in good agreement with observations; however, the <span class="hlt">age</span> spectra determined from the DAS differ from the GCM spectra. For the diabatic trajectory calculations, the <span class="hlt">age</span> spectrum is too broad as a result of too much exchange between the tropics and mid-latitudes. The <span class="hlt">age</span> spectrum determined using the kinematic trajectory calculation is less broad and lacks an <span class="hlt">age</span> offset; both of these features are due to excessive vertical dispersion of parcels. The tropical and mid-latitude mean <span class="hlt">age</span> difference between the diabatically and kinematically determined <span class="hlt">age</span>-spectra is about one year, the former being older. The CTM calculation of the <span class="hlt">age</span> spectrum using the DAS winds shows the same dispersive characteristics of the kinematic trajectory calculation. These results suggest that the current DAS products will not give realistic trace gas distributions for long integrations; they also help explain why the mean <span class="hlt">ages</span> determined in a number of previous DAS driven CTM's are too young compared with observations. Finally, we note trajectory-generated <span class="hlt">age</span> spectra show significant <span class="hlt">age</span> anomalies correlated with the seasonal cycles, and these anomalies can be linked to year-to-year variations in the tropical heating rate. These anomalies are suppressed in the CTM spectra suggesting that the CTM transport is too diffusive.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..93b2309T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..93b2309T"><span id="translatedtitle">Dynamical network <span class="hlt">model</span> for <span class="hlt">age</span>-related health deficits and mortality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taneja, Swadhin; Mitnitski, Arnold B.; Rockwood, Kenneth; Rutenberg, Andrew D.</p> <p>2016-02-01</p> <p>How long people live depends on their health, and how it changes with <span class="hlt">age</span>. Individual health can be tracked by the accumulation of <span class="hlt">age</span>-related health deficits. The fraction of <span class="hlt">age</span>-related deficits is a simple quantitative measure of human <span class="hlt">aging</span>. This quantitative frailty index (F ) is as good as chronological <span class="hlt">age</span> in predicting mortality. In this paper, we use a dynamical network <span class="hlt">model</span> of deficits to explore the effects of interactions between deficits, deficit damage and repair processes, and the connection between the F and mortality. With our <span class="hlt">model</span>, we qualitatively reproduce Gompertz's law of increasing human mortality with <span class="hlt">age</span>, the broadening of the F distribution with <span class="hlt">age</span>, the characteristic nonlinear increase of the F with <span class="hlt">age</span>, and the increased mortality of high-frailty individuals. No explicit time-dependence in damage or repair rates is needed in our <span class="hlt">model</span>. Instead, implicit time-dependence arises through deficit interactions—so that the average deficit damage rates increase, and deficit repair rates decrease, with <span class="hlt">age</span>. We use a simple mortality criterion, where mortality occurs when the most connected node is damaged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3869774','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3869774"><span id="translatedtitle">A Genome-Wide Longitudinal Transcriptome Analysis of the <span class="hlt">Aging</span> <span class="hlt">Model</span> Podospora anserine</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Philipp, Oliver; Hamann, Andrea; Servos, Jörg; Werner, Alexandra; Koch, Ina; Osiewacz, Heinz D.</p> <p>2013-01-01</p> <p><span class="hlt">Aging</span> of biological systems is controlled by various processes which have a potential impact on gene expression. Here we report a genome-wide transcriptome analysis of the fungal <span class="hlt">aging</span> <span class="hlt">model</span> Podospora anserina. Total RNA of three individuals of defined <span class="hlt">age</span> were pooled and analyzed by SuperSAGE (serial analysis of gene expression). A bioinformatics analysis identified different molecular pathways to be affected during <span class="hlt">aging</span>. While the abundance of transcripts linked to ribosomes and to the proteasome quality control system were found to decrease during <span class="hlt">aging</span>, those associated with autophagy increase, suggesting that autophagy may act as a compensatory quality control pathway. Transcript profiles associated with the energy metabolism including mitochondrial functions were identified to fluctuate during <span class="hlt">aging</span>. Comparison of wild-type transcripts, which are continuously down-regulated during <span class="hlt">aging</span>, with those down-regulated in the long-lived, copper-uptake mutant grisea, validated the relevance of <span class="hlt">age</span>-related changes in cellular copper metabolism. Overall, we (i) present a unique <span class="hlt">age</span>-related data set of a longitudinal study of the experimental <span class="hlt">aging</span> <span class="hlt">model</span> P. anserina which represents a reference resource for future investigations in a variety of organisms, (ii) suggest autophagy to be a key quality control pathway that becomes active once other pathways fail, and (iii) present testable predictions for subsequent experimental investigations. PMID:24376646</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2527630','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2527630"><span id="translatedtitle">Comparative and alternative approaches and novel animal <span class="hlt">models</span> for <span class="hlt">aging</span> research</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kristan, D. M.</p> <p>2008-01-01</p> <p>This special issue of <span class="hlt">AGE</span> showcases powerful alternative or unconventional approaches to basic <span class="hlt">aging</span> research, including the use of exceptionally long-lived animal <span class="hlt">model</span> species and comparative methods from evolutionary biology. In this opening paper, we introduce several of these alternative <span class="hlt">aging</span> research themes, including the comparative phylogenetic approach. This approach applies modern inferential methods for dissecting basic physiological and biochemical mechanisms correlated with phenotypic traits including longevity, slow <span class="hlt">aging</span>, sustained somatic maintenance, and repair of molecular damage. Comparative methods can be used to assess the general relevance of specific <span class="hlt">aging</span> mechanisms—including oxidative processes—to diverse animal species, as well as to assess their potential clinical relevance to humans and other mammals. We also introduce several other novel, underexploited approaches with particular relevance to biogerontology, including the use of <span class="hlt">model</span> animal species or strains that retain natural genetic heterogeneity, studies of effects of infectious disease and parasites on <span class="hlt">aging</span> and responses to caloric restriction, studies of reproductive <span class="hlt">aging</span>, and naturally occurring sex differences in <span class="hlt">aging</span>. We emphasize the importance of drawing inferences from <span class="hlt">aging</span> phenomena in laboratory studies that can be applied to clinically relevant <span class="hlt">aging</span> syndromes in long-lived, outbred animals, including humans. PMID:19424857</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880033615&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DVALUE%2BABSOLUTE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880033615&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DVALUE%2BABSOLUTE"><span id="translatedtitle"><span class="hlt">Absolute</span> instability of the Gaussian wake profile</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hultgren, Lennart S.; Aggarwal, Arun K.</p> <p>1987-01-01</p> <p>Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local <span class="hlt">absolute</span> instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or <span class="hlt">absolute</span>, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. <span class="hlt">Absolute</span> instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of <span class="hlt">absolute</span> instability with decreasing wake Reynolds number. If backflow is not allowed, <span class="hlt">absolute</span> instability does not occur for wake Reynolds numbers smaller than about 38.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Baton+AND+Rouge&pg=6&id=ED244176','ERIC'); return false;" href="http://eric.ed.gov/?q=Baton+AND+Rouge&pg=6&id=ED244176"><span id="translatedtitle">A <span class="hlt">Model</span> for Incorporating Content on <span class="hlt">Aging</span> into the Curriculum: K-12.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Blackwell, David L.; Hunt, Sara Stockard</p> <p></p> <p>Following a statement of the problem of putting <span class="hlt">aging</span> education in the elementary secondary curriculum, and a review of the relevant literature, a <span class="hlt">model</span> for developing a curriculum on <span class="hlt">aging</span> is presented. An overview of the 3-year project, developed in Baton Rouge, Louisiana schools for grades K-12, is offered, including activities and yearly…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=time&pg=6&id=EJ1044863','ERIC'); return false;" href="http://eric.ed.gov/?q=time&pg=6&id=EJ1044863"><span id="translatedtitle"><span class="hlt">Modeling</span> the Phenotypic Architecture of Autism Symptoms from Time of Diagnosis to <span class="hlt">Age</span> 6</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Georgiades, Stelios; Boyle, Michael; Szatmari, Peter; Hanna, Steven; Duku, Eric; Zwaigenbaum, Lonnie; Bryson, Susan; Fombonne, Eric; Volden, Joanne; Mirenda, Pat; Smith, Isabel; Roberts, Wendy; Vaillancourt, Tracy; Waddell, Charlotte; Bennett, Teresa; Elsabbagh, Mayada; Thompson, Ann</p> <p>2014-01-01</p> <p>The latent class structure of autism symptoms from the time of diagnosis to <span class="hlt">age</span> 6 years was examined in a sample of 280 children with autism spectrum disorder. Factor mixture <span class="hlt">modeling</span> was performed on 26 algorithm items from the Autism Diagnostic Interview-Revised at diagnosis (Time 1) and again at <span class="hlt">age</span> 6 (Time 2). At Time 1, a…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=adaptive+AND+syndrome&pg=6&id=EJ666156','ERIC'); return false;" href="http://eric.ed.gov/?q=adaptive+AND+syndrome&pg=6&id=EJ666156"><span id="translatedtitle">Adaptive Behavior and Cognitive Function of Adults with Down Syndrome: <span class="hlt">Modeling</span> Change with <span class="hlt">Age</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hawkins, Barbara A.; Eklund, Susan J.; James, David R.; Foose, Alice K.</p> <p>2003-01-01</p> <p>Fifty-eight adults with Down syndrome were assessed longitudinally over 10 years for the purpose of <span class="hlt">modeling</span> <span class="hlt">aging</span>-related change in cognitive function and adaptive behavior. Findings provide further evidence of changes in performance with <span class="hlt">age</span> and include selected effects for participants who completed the study and those lost to follow-up.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=aging&pg=5&id=EJ965005','ERIC'); return false;" href="http://eric.ed.gov/?q=aging&pg=5&id=EJ965005"><span id="translatedtitle"><span class="hlt">Aging</span> Well and the Environment: Toward an Integrative <span class="hlt">Model</span> and Research Agenda for the Future</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wahl, Hans-Werner; Iwarsson, Susanne; Oswald, Frank</p> <p>2012-01-01</p> <p>Purpose of the Study: The effects of the physical-spatial-technical environment on <span class="hlt">aging</span> well have been overlooked both conceptually and empirically. In the spirit of M. Powell Lawton's seminal work on <span class="hlt">aging</span> and environment, this article attempts to rectify this situation by suggesting a new <span class="hlt">model</span> of how older people interact with their…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=IQ+AND+testing&pg=7&id=EJ724231','ERIC'); return false;" href="http://eric.ed.gov/?q=IQ+AND+testing&pg=7&id=EJ724231"><span id="translatedtitle"><span class="hlt">Age</span> Differences within Secular IQ Trends: An Individual Growth <span class="hlt">Modeling</span> Approach</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kanaya, Tomoe; Ceci, Stephen J.; Scullin, Matthew H.</p> <p>2005-01-01</p> <p><span class="hlt">Age</span> differences within the yo-yo trend in IQ, caused when <span class="hlt">aging</span> norms that produce inflated scores are replaced with new norms, were examined using longitudinal WISC, WISC-R and WISC-III records of students tested for special education services from 10 school districts. Descriptive and individual growth <span class="hlt">modeling</span> analyses revealed that while the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23244406','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23244406"><span id="translatedtitle">Conscientiousness, health, and <span class="hlt">aging</span>: the life course of personality <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shanahan, Michael J; Hill, Patrick L; Roberts, Brent W; Eccles, Jacquelynne; Friedman, Howard S</p> <p>2014-05-01</p> <p>The Conscientiousness (C) of the self and significant others influences health by way of mediational chains involving socioeconomic attainment, the avoidance and neutralization of stressors, the promotion of health behaviors and the minimization of risk behaviors, and the management of symptoms and diseases. Yet, meta-analyses reveal that these associations are moderated by factors that are not well understood. We propose the Life Course of Personality <span class="hlt">Model</span> (LCP <span class="hlt">Model</span>), which comprises a series of hypotheses that suggest how such mediational chains are subject to 2 sources of contingency. First, the mechanisms by which C translates into health and the avoidance of risk change from early childhood to late adulthood, involving processes that are specific to phases of the life course; also, however, C influences health by way of continuous processes extending over many decades of life. Second, C may be more consequential in some social contexts than in others, and when accompanied by some constellations of personality characteristics than by others. That is, the mediational processes by which C translates into health and the avoidance of disease are likely moderated by timing, social context (including the C of others), and other aspects of the individual's personality. We consider methodological implications of the LCP <span class="hlt">Model</span>. PMID:23244406</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1084175','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1084175"><span id="translatedtitle">Development and validation of a black carbon mixing state resolved three-dimensional <span class="hlt">model</span>: <span class="hlt">Aging</span> processes and radiative impact</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Matsui, H.; Koike, Makoto; Kondo, Yutaka; Moteki, N.; Fast, Jerome D.; Zaveri, Rahul A.</p> <p>2013-03-16</p> <p>: A new two-dimensional aerosol bin scheme, which resolves both aerosol size and black carbon (BC) mixing state for BC <span class="hlt">aging</span> processes (e.g., condensation and coagulation), has been developed and implemented into the WRF-chem <span class="hlt">model</span> (MS-resolved WRF-chem). The mixing state of BC simulated by this <span class="hlt">model</span> is compared with direct measurements over the East Asian region in spring 2009. <span class="hlt">Model</span> simulations generally reproduce the observed features of the BC mixing state, such as the size-dependent number fractions of BC-containing and BC-free particles and the coating thickness of BC-containing particles. Sensitivity simulations show that the condensation process is dominant for the growth of thinly coated BC particles, while the coagulation process is necessary to produce thickly coated BC particles. Off-line optical and radiative calculations assuming an average mixing state for each size bin show that the domain- and period-averaged absorption coefficient and heating rate by aerosols are overestimated by 30 – 40% in the boundary layer compared with a benchmark simulation with the detailed treatment of mixing state. The <span class="hlt">absolute</span> value of aerosol radiative forcing is also overestimated (10%, 3 W m-2) at the surface. However, these overestimations are reduced considerably when all the parameters (including mass and number concentration) are calculated with the simple treatment of mixing state. This is because the overestimation of radiative parameters due to higher absorption efficiency (compared with the benchmark simulation) is largely canceled by the underestimation of BC concentrations due to efficient wet removal processes. The overall errors in radiative forcing can be much smaller because of this cancellation but for the wrong reasons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4142703','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4142703"><span id="translatedtitle"><span class="hlt">Modeling</span> old-<span class="hlt">age</span> wealth with endogenous early-life outcomes: The case of Mexico</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>DeGraff, Deborah S.; Wong, Rebeca</p> <p>2014-01-01</p> <p>This paper contributes to the literature on the life course and <span class="hlt">aging</span> by examining the association between early-life outcomes and late-life well being, using data from the Mexican Health and <span class="hlt">Aging</span> Study. Empirical research in this area has been challenged by the potential endogeneity of the early-life outcomes of interest, an issue which most studies ignore or downplay. Our contribution takes two forms: (1) we examine in detail the potential importance of two key life-cycle outcomes, <span class="hlt">age</span> at marriage (a measure of family formation) and years of educational attainment (a measure of human capital investment) for old-<span class="hlt">age</span> wealth, and (2) we illustrate the empirical value of past context variables that could help <span class="hlt">model</span> the association between early-life outcomes and late-life well being. Our illustrative approach, matching macro-level historical policy and census variables to individual records to use as instruments in <span class="hlt">modeling</span> the endogeneity of early-life behaviors, yields a statistically identified two-stage <span class="hlt">model</span> of old-<span class="hlt">age</span> wealth with minimum bias. We use simulations to show that the results for the <span class="hlt">model</span> of wealth in old <span class="hlt">age</span> are meaningfully different when comparing the approach that accounts for endogeneity with an approach that assumes exogeneity of early-life outcomes. Furthermore, our results suggest that in the Mexican case, <span class="hlt">models</span> which ignore the potential endogeneity of early-life outcomes are likely to under-estimate the effects of such variables on old-<span class="hlt">age</span> wealth. PMID:25170434</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25170434','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25170434"><span id="translatedtitle"><span class="hlt">Modeling</span> old-<span class="hlt">age</span> wealth with endogenous early-life outcomes: The case of Mexico.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>DeGraff, Deborah S; Wong, Rebeca</p> <p>2014-04-01</p> <p>This paper contributes to the literature on the life course and <span class="hlt">aging</span> by examining the association between early-life outcomes and late-life well being, using data from the Mexican Health and <span class="hlt">Aging</span> Study. Empirical research in this area has been challenged by the potential endogeneity of the early-life outcomes of interest, an issue which most studies ignore or downplay. Our contribution takes two forms: (1) we examine in detail the potential importance of two key life-cycle outcomes, <span class="hlt">age</span> at marriage (a measure of family formation) and years of educational attainment (a measure of human capital investment) for old-<span class="hlt">age</span> wealth, and (2) we illustrate the empirical value of past context variables that could help <span class="hlt">model</span> the association between early-life outcomes and late-life well being. Our illustrative approach, matching macro-level historical policy and census variables to individual records to use as instruments in <span class="hlt">modeling</span> the endogeneity of early-life behaviors, yields a statistically identified two-stage <span class="hlt">model</span> of old-<span class="hlt">age</span> wealth with minimum bias. We use simulations to show that the results for the <span class="hlt">model</span> of wealth in old <span class="hlt">age</span> are meaningfully different when comparing the approach that accounts for endogeneity with an approach that assumes exogeneity of early-life outcomes. Furthermore, our results suggest that in the Mexican case, <span class="hlt">models</span> which ignore the potential endogeneity of early-life outcomes are likely to under-estimate the effects of such variables on old-<span class="hlt">age</span> wealth. PMID:25170434</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23281647','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23281647"><span id="translatedtitle">Mathematical <span class="hlt">modeling</span> of left ventricular dimensional changes in mice during <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Tianyi; Chiao, Ying Ann; Wang, Yunji; Voorhees, Andrew; Han, Hai-Chao; Lindsey, Merry L; Jin, Yu-Fang</p> <p>2012-01-01</p> <p>Cardiac <span class="hlt">aging</span> is characterized by diastolic dysfunction of the left ventricle (LV), which is due in part to increased LV wall stiffness. In the diastolic phase, myocytes are relaxed and extracellular matrix (ECM) is a critical determinant to the changes of LV wall stiffness. To evaluate the effects of ECM composition on cardiac <span class="hlt">aging</span>, we developed a mathematical <span class="hlt">model</span> to predict LV dimension and wall stiffness changes in <span class="hlt">aging</span> mice by integrating mechanical laws and our experimental results. We measured LV dimension, wall thickness, LV mass, and collagen content for wild type (WT) C57/BL6J mice of <span class="hlt">ages</span> ranging from 7.3 months to those of 34.0 months. The <span class="hlt">model</span> was established using the thick wall theory and stretch-induced tissue growth to an isotropic and homogeneous elastic composite with mixed constituents. The initial conditions of the simulation were set based on the data from the young mice. Matlab simulations of this mathematical <span class="hlt">model</span> demonstrated that the <span class="hlt">model</span> captured the major features of LV remodeling with <span class="hlt">age</span> and closely approximated experimental results. Specifically, the temporal progression of the LV interior and exterior dimensions demonstrated the same trend and order-of-magnitude change as our experimental results. In conclusion, we present here a validated mathematical <span class="hlt">model</span> of cardiac <span class="hlt">aging</span> that applies the thick-wall theory and stretch-induced tissue growth to LV remodeling with <span class="hlt">age</span>. PMID:23281647</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3524011','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3524011"><span id="translatedtitle">Mathematical <span class="hlt">modeling</span> of left ventricular dimensional changes in mice during <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Cardiac <span class="hlt">aging</span> is characterized by diastolic dysfunction of the left ventricle (LV), which is due in part to increased LV wall stiffness. In the diastolic phase, myocytes are relaxed and extracellular matrix (ECM) is a critical determinant to the changes of LV wall stiffness. To evaluate the effects of ECM composition on cardiac <span class="hlt">aging</span>, we developed a mathematical <span class="hlt">model</span> to predict LV dimension and wall stiffness changes in <span class="hlt">aging</span> mice by integrating mechanical laws and our experimental results. We measured LV dimension, wall thickness, LV mass, and collagen content for wild type (WT) C57/BL6J mice of <span class="hlt">ages</span> ranging from 7.3 months to those of 34.0 months. The <span class="hlt">model</span> was established using the thick wall theory and stretch-induced tissue growth to an isotropic and homogeneous elastic composite with mixed constituents. The initial conditions of the simulation were set based on the data from the young mice. Matlab simulations of this mathematical <span class="hlt">model</span> demonstrated that the <span class="hlt">model</span> captured the major features of LV remodeling with <span class="hlt">age</span> and closely approximated experimental results. Specifically, the temporal progression of the LV interior and exterior dimensions demonstrated the same trend and order-of-magnitude change as our experimental results. In conclusion, we present here a validated mathematical <span class="hlt">model</span> of cardiac <span class="hlt">aging</span> that applies the thick-wall theory and stretch-induced tissue growth to LV remodeling with <span class="hlt">age</span>. PMID:23281647</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhyA..245...99M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhyA..245...99M"><span id="translatedtitle">Dynamical properties of the Penna <span class="hlt">aging</span> <span class="hlt">model</span> applied to the population of wolves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Makowiec, Danuta</p> <p>1997-02-01</p> <p>The parameters of th Penna bit-string <span class="hlt">model</span> of <span class="hlt">aging</span> of biological systems are systematically tested to better understand the <span class="hlt">model</span> itself as well as the results arising from applying this <span class="hlt">model</span> to studies of the development of the stationary population of Alaska wolves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005EPJB...45..533L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005EPJB...45..533L"><span id="translatedtitle">Degeneration of the Y chromosome in evolutionary <span class="hlt">aging</span> <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lobo, M. P.; Onody, R. N.</p> <p>2005-06-01</p> <p>The Y chromosomes are genetically degenerated and do not recombine with their matching partners X. Recombination of XX pairs is pointed out as the key factor for the Y chromosome degeneration. However, there is an additional evolutionary force driving sex-chromosomes evolution. Here we show this mechanism by means of two different evolutionary <span class="hlt">models</span>, in which sex chromosomes with non-recombining XX and XY pairs of chromosomes is considered. Our results show three curious effects. First, we observed that even when both XX and XY pairs of chromosomes do not recombine, the Y chromosomes still degenerate. Second, the accumulation of mutations on Y chromosomes followed a completely different pattern then those accumulated on X chromosomes. And third, the <span class="hlt">models</span> may differ with respect to sexual proportion. These findings suggest that a more primeval mechanism rules the evolution of Y chromosomes due exclusively to the sex-chromosomes asymmetry itself, i.e., the fact that Y chromosomes never experience female bodies. Over aeons, natural selection favored X chromosomes spontaneously, even if at the very beginning of evolution, both XX and XY pairs of chromosomes did not recombine.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2866528','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2866528"><span id="translatedtitle"><span class="hlt">Age</span>-dependent cognitive impairment in a Drosophila Fragile X <span class="hlt">model</span> and its pharmacological rescue</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Choi, Catherine H.; Schoenfeld, Brian P.; Liebelt, David A.; Ferreiro, David; Ferrick, Neal J.; Hinchey, Paul; Kollaros, Maria; Rudominer, Rebecca L.; Terlizzi, Allison M.; Koenigsberg, Eric; Wang, Yan; Sumida, Ai; Nguyen, Hanh T.; Bell, Aaron J.; McDonald, Thomas V.</p> <p>2010-01-01</p> <p>Fragile X syndrome afflicts 1 in 2,500 individuals and is the leading heritable cause of mental retardation worldwide. The overriding clinical manifestation of this disease is mild to severe cognitive impairment. <span class="hlt">Age</span>-dependent cognitive decline has been identified in Fragile X patients, although it has not been fully characterized nor examined in animal <span class="hlt">models</span>. A Drosophila <span class="hlt">model</span> of this disease has been shown to display phenotypes bearing similarity to Fragile X symptoms. Most notably, we previously identified naive courtship and memory deficits in young adults with this <span class="hlt">model</span> that appear to be due to enhanced metabotropic glutamate receptor (mGluR) signaling. Herein we have examined <span class="hlt">age</span>-related cognitive decline in the Drosophila Fragile X <span class="hlt">model</span> and found an <span class="hlt">age</span>-dependent loss of learning during training. We demonstrate that treatment with mGluR antagonists or lithium can prevent this <span class="hlt">age</span>-dependent cognitive impairment. We also show that treatment with mGluR antagonists or lithium during development alone displays differential efficacy in its ability to rescue naive courtship, learning during training and memory in <span class="hlt">aged</span> flies. Furthermore, we show that continuous treatment during <span class="hlt">aging</span> effectively rescues all of these phenotypes. These results indicate that the Drosophila <span class="hlt">model</span> recapitulates the <span class="hlt">age</span>-dependent cognitive decline observed in humans. This places Fragile X in a category with several other diseases that result in <span class="hlt">age</span>-dependent cognitive decline. This demonstrates a role for the Drosophila Fragile X Mental Retardation Protein (dFMR1) in neuronal physiology with regard to cognition during the <span class="hlt">aging</span> process. Our results indicate that misregulation of mGluR activity may be causative of this <span class="hlt">age</span> onset decline and strengthens the possibility that mGluR antagonists and lithium may be potential pharmacologic compounds for counteracting several Fragile X symptoms. PMID:20039205</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4663277','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4663277"><span id="translatedtitle"><span class="hlt">Age</span>-Related Changes in Predictive Capacity Versus Internal <span class="hlt">Model</span> Adaptability: Electrophysiological Evidence that Individual Differences Outweigh Effects of <span class="hlt">Age</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bornkessel-Schlesewsky, Ina; Philipp, Markus; Alday, Phillip M.; Kretzschmar, Franziska; Grewe, Tanja; Gumpert, Maike; Schumacher, Petra B.; Schlesewsky, Matthias</p> <p>2015-01-01</p> <p>Hierarchical predictive coding has been identified as a possible unifying principle of brain function, and recent work in cognitive neuroscience has examined how it may be affected by age–related changes. Using language comprehension as a test case, the present study aimed to dissociate <span class="hlt">age</span>-related changes in prediction generation versus internal <span class="hlt">model</span> adaptation following a prediction error. Event-related brain potentials (ERPs) were measured in a group of older adults (60–81 years; n = 40) as they read sentences of the form “The opposite of black is white/yellow/nice.” Replicating previous work in young adults, results showed a target-related P300 for the expected antonym (“white”; an effect assumed to reflect a prediction match), and a graded N400 effect for the two incongruous conditions (i.e. a larger N400 amplitude for the incongruous continuation not related to the expected antonym, “nice,” versus the incongruous associated condition, “yellow”). These effects were followed by a late positivity, again with a larger amplitude in the incongruous non-associated versus incongruous associated condition. Analyses using linear mixed-effects <span class="hlt">models</span> showed that the target-related P300 effect and the N400 effect for the incongruous non-associated condition were both modulated by <span class="hlt">age</span>, thus suggesting that <span class="hlt">age</span>-related changes affect both prediction generation and <span class="hlt">model</span> adaptation. However, effects of <span class="hlt">age</span> were outweighed by the interindividual variability of ERP responses, as reflected in the high proportion of variance captured by the inclusion of by-condition random slopes for participants and items. We thus argue that – at both a neurophysiological and a functional level – the notion of general differences between language processing in young and older adults may only be of limited use, and that future research should seek to better understand the causes of interindividual variability in the ERP responses of older adults and its relation to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4829813','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4829813"><span id="translatedtitle">Oxidative stress and <span class="hlt">age</span>-related changes in T cells: is thalassemia a <span class="hlt">model</span> of accelerated immune system <span class="hlt">aging</span>?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ghatreh-Samani, Mahdi; Esmaeili, Nafiseh; Soleimani, Masoud; Asadi-Samani, Majid; Ghatreh-Samani, Keihan</p> <p>2016-01-01</p> <p>Iron overload in β-thalassemia major occurs mainly due to blood transfusion, an essential treatment for β-thalassemia major patients, which results in oxidative stress. It has been thought that oxidative stress causes elevation of immune system senescent cells. Under this condition, cells normally enhance in <span class="hlt">aging</span>, which is referred to as premature immunosenescence. Because there is no animal <span class="hlt">model</span> for immunosenescence, most knowledge on the immunosenescence pattern is based on induction of immunosenescence. In this review, we describe iron overload and oxidative stress in β-thalassemia major patients and how they make these patients a suitable human <span class="hlt">model</span> for immunosenescence. We also consider oxidative stress in some kinds of chronic virus infections, which induce changes in the immune system similar to β-thalassemia major. In conclusion, a therapeutic approach used to improve the immune system in such chronic virus diseases, may change the immunosenescence state and make life conditions better for β-thalassemia major patients. PMID:27095931</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP51F..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP51F..05L"><span id="translatedtitle">Dune Morphometry in the <span class="hlt">Age</span> of Digital Elevation <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lancaster, N.</p> <p>2014-12-01</p> <p>Dune patterns can be characterized in many different ways. Relationships between dune height, width and spacing, and the spatial variation in these parameters have been widely employed to provide quantitative information that can be used to describe dune patterns and make comparisons between dunes in widely separated areas, as well as to identify different generations of dunes. Digital elevation <span class="hlt">models</span> (e.g. ASTER GDEM) provide a rich resource of data for analyses of dune patterns at landscape scales in several ways, including: (1) more extensive analyses using traditional measures, such as relationships between dune height and spacing, and the spatial variation in these parameters; and (2) estimation of sediment thickness on a regional scale. Analyses of data for Arabian and Namibian sand seas and dune fields show that dune height and spacing relationships are much more variable than previously reported and call into question existing <span class="hlt">models</span>. Regional patterns of sediment thickness reveal areas of erosion, bypass, and accumulation that can be related to transport pathways and wind regimes. The widespread occurrence of complex dune patterns as well as the magnitude of the newly available data sets however requires more sophisticated analyses than simple extraction of dune morphometric parameters using GIS approaches. Geostatistical analyses using spatial autocorrelation, Fourier, and Wavelet methods have been employed in analyses of sub-aqueous bedforms and show promise for dune systems. Automated or semi-automated identification of dune length, width, spacing, and trends using advanced image analysis techniques such as linear segment detection is a potentially transformative approach. The strengths and weaknesses of these methods to provide pertinent geomorphic information are currently being evaluated, but they have the potential to provide new insights into the nature of dune patterns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3922947','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3922947"><span id="translatedtitle">Systems integrity in health and <span class="hlt">aging</span> - an animal <span class="hlt">model</span> approach</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>Human lifespan is positively correlated with childhood intelligence, as measured by psychometric (IQ) tests. The strength of this correlation is similar to the negative effect that smoking has on the life course. This result suggests that people who perform well on psychometric tests in childhood may remain healthier and live longer. The correlation, however, is debated: is it caused exclusively by social-environmental factors or could it also have a biological component? Biological traits of systems integrity that might result in correlations between brain function and lifespan have been suggested but are not well-established, and it is questioned what useful knowledge can come from understanding such mechanisms. In a recent study, we found a positive correlation between brain function and longevity in honey bees. Honey bees are highly social, but relevant social-environmental factors that contribute to cognition-survival correlations in humans are largely absent from insect colonies. Our results, therefore, suggest a biological explanation for the correlation in the bee. Here, we argue that individual differences in stress handling (coping) mechanisms, which both affect the bees’ performance in tests of brain function and their survival could be a trait of systems integrity. Individual differences in coping are much studied in vertebrates, and several species provide attractive <span class="hlt">models</span>. Here, we discuss how pigs are an interesting <span class="hlt">model</span> for studying behavioural, physiological and molecular mechanisms that are recruited during stress and that can drive correlations between health, cognition and longevity traits. By revealing biological factors that make individuals susceptible to stress, it might be possible to alleviate health and longevity disparities in people. PMID:24472488</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24472488','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24472488"><span id="translatedtitle">Systems integrity in health and <span class="hlt">aging</span> - an animal <span class="hlt">model</span> approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oostindjer, Marije; Amdam, Gro V</p> <p>2013-01-01</p> <p>Human lifespan is positively correlated with childhood intelligence, as measured by psychometric (IQ) tests. The strength of this correlation is similar to the negative effect that smoking has on the life course. This result suggests that people who perform well on psychometric tests in childhood may remain healthier and live longer. The correlation, however, is debated: is it caused exclusively by social-environmental factors or could it also have a biological component? Biological traits of systems integrity that might result in correlations between brain function and lifespan have been suggested but are not well-established, and it is questioned what useful knowledge can come from understanding such mechanisms. In a recent study, we found a positive correlation between brain function and longevity in honey bees. Honey bees are highly social, but relevant social-environmental factors that contribute to cognition-survival correlations in humans are largely absent from insect colonies. Our results, therefore, suggest a biological explanation for the correlation in the bee. Here, we argue that individual differences in stress handling (coping) mechanisms, which both affect the bees' performance in tests of brain function and their survival could be a trait of systems integrity. Individual differences in coping are much studied in vertebrates, and several species provide attractive <span class="hlt">models</span>. Here, we discuss how pigs are an interesting <span class="hlt">model</span> for studying behavioural, physiological and molecular mechanisms that are recruited during stress and that can drive correlations between health, cognition and longevity traits. By revealing biological factors that make individuals susceptible to stress, it might be possible to alleviate health and longevity disparities in people. PMID:24472488</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26538520','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26538520"><span id="translatedtitle">The zebrafish as a gerontology <span class="hlt">model</span> in nervous system <span class="hlt">aging</span>, disease, and repair.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Houcke, Jessie; De Groef, Lies; Dekeyster, Eline; Moons, Lieve</p> <p>2015-11-01</p> <p>Considering the increasing number of elderly in the world's population today, developing effective treatments for <span class="hlt">age</span>-related pathologies is one of the biggest challenges in modern medical research. <span class="hlt">Age</span>-related neurodegeneration, in particular, significantly impacts important sensory, motor, and cognitive functions, seriously constraining life quality of many patients. Although our understanding of the causal mechanisms of <span class="hlt">aging</span> has greatly improved in recent years, animal <span class="hlt">model</span> systems still have much to tell us about this complex process. Zebrafish (Danio rerio) have gained enormous popularity for this research topic over the past decade, since their life span is relatively short but, like humans, they are still subject to gradual <span class="hlt">aging</span>. In addition, the extensive characterization of its well-conserved molecular and cellular physiology makes the zebrafish an excellent <span class="hlt">model</span> to unravel the underlying mechanisms of <span class="hlt">aging</span>, disease, and repair. This review provides a comprehensive overview of the progress made in zebrafish gerontology, with special emphasis on nervous system <span class="hlt">aging</span>. We review the evidence that classic hallmarks of <span class="hlt">aging</span> can also be recognized within this small vertebrate, both at the molecular and cellular level. Moreover, we illustrate the high level of similarity with <span class="hlt">age</span>-associated human pathologies through a survey of the functional deficits that arise as zebrafish <span class="hlt">age</span>. PMID:26538520</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26150061','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26150061"><span id="translatedtitle">Understanding the link between sexual selection, sexual conflict and <span class="hlt">aging</span> using crickets as a <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Archer, C Ruth; Hunt, John</p> <p>2015-11-01</p> <p><span class="hlt">Aging</span> evolved because the strength of natural selection declines over the lifetime of most organisms. Weak natural selection late in life allows the accumulation of deleterious mutations and may favor alleles that have positive effects on fitness early in life, but costly pleiotropic effects expressed later on. While this decline in natural selection is central to longstanding evolutionary explanations for <span class="hlt">aging</span>, a role for sexual selection and sexual conflict in the evolution of lifespan and <span class="hlt">aging</span> has only been identified recently. Testing how sexual selection and sexual conflict affect lifespan and <span class="hlt">aging</span> is challenging as it requires quantifying male <span class="hlt">age</span>-dependent reproductive success. This is difficult in the invertebrate <span class="hlt">model</span> organisms traditionally used in <span class="hlt">aging</span> research. Research using crickets (Orthoptera: Gryllidae), where reproductive investment can be easily measured in both sexes, has offered exciting and novel insights into how sexual selection and sexual conflict affect the evolution of <span class="hlt">aging</span>, both in the laboratory and in the wild. Here we discuss how sexual selection and sexual conflict can be integrated alongside evolutionary and mechanistic theories of <span class="hlt">aging</span> using crickets as a <span class="hlt">model</span>. We then highlight the potential for research using crickets to further advance our understanding of lifespan and <span class="hlt">aging</span>. PMID:26150061</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26022140','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26022140"><span id="translatedtitle">Grape powder treatment prevents anxiety-like behavior in a rat <span class="hlt">model</span> of <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Patki, Gaurav; Ali, Quaisar; Pokkunuri, Indira; Asghar, Mohammad; Salim, Samina</p> <p>2015-06-01</p> <p>Earlier, we have reported that grape powder (GP) treatment prevented pharmacologic and psychological stress-induced anxiety-like behavior and memory impairment in rats. Protective effects of GP were attributed to its antioxidant effects. In this study, we tested the hypothesis that <span class="hlt">age</span>-associated behavioral and cognitive deficits such as anxiety and memory impairment will be ameliorated with GP treatment. Using a National Institute of <span class="hlt">Aging</span> recommended rodent <span class="hlt">model</span> of <span class="hlt">aging</span>, we examined a potentially protective role of antioxidant-rich GP in <span class="hlt">age</span>-associated anxiety-like behavior and memory impairment. Male Fischer 344 rats were randomly assigned into 4 groups: young rats (3 months old) provided with tap water or with 15 g/L GP dissolved in tap water for 3 weeks, <span class="hlt">aged</span> rats (21 months old) provided with tap water or with GP-treated tap water for 3 weeks (AG-GP). Anxiety-like behavior was significantly greater in <span class="hlt">aged</span> rats compared with young rats, GP-treated young rats, or <span class="hlt">aged</span> control rats (P < .05). Also, GP treatment prevented <span class="hlt">age</span>-induced anxiety-like behavior in AG-GP rats (P < .05). Neither short-term nor long-term <span class="hlt">age</span>-associated memory deficits improved with GP treatment in AG-GP rats. Furthermore, <span class="hlt">aged</span> rats showed increased level of physiological stress (corticosterone) and increased oxidative stress in the plasma (8-isoprostane) as well as in selected brain areas (protein carbonylation). Grape powder treatment prevented <span class="hlt">age</span>-induced increase in corticosterone levels and plasma 8-isoprostane levels in <span class="hlt">aged</span> rats (P < .05), whereas protein carbonylation was recovered in the amygdala region only (P < .05). Grape powder by regulating oxidative stress ameliorates <span class="hlt">age</span>-induced anxiety-like behavior in rats, whereas <span class="hlt">age</span>-associated memory deficits seem unaffected with GP treatment. PMID:26022140</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24315443','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24315443"><span id="translatedtitle">Human iPSC-based <span class="hlt">modeling</span> of late-onset disease via progerin-induced <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miller, Justine D; Ganat, Yosif M; Kishinevsky, Sarah; Bowman, Robert L; Liu, Becky; Tu, Edmund Y; Mandal, Pankaj K; Vera, Elsa; Shim, Jae-won; Kriks, Sonja; Taldone, Tony; Fusaki, Noemi; Tomishima, Mark J; Krainc, Dimitri; Milner, Teresa A; Rossi, Derrick J; Studer, Lorenz</p> <p>2013-12-01</p> <p>Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) resets their identity back to an embryonic <span class="hlt">age</span> and, thus, presents a significant hurdle for <span class="hlt">modeling</span> late-onset disorders. In this study, we describe a strategy for inducing <span class="hlt">aging</span>-related features in human iPSC-derived lineages and apply it to the <span class="hlt">modeling</span> of Parkinson's disease (PD). Our approach involves expression of progerin, a truncated form of lamin A associated with premature <span class="hlt">aging</span>. We found that expression of progerin in iPSC-derived fibroblasts and neurons induces multiple <span class="hlt">aging</span>-related markers and characteristics, including dopamine-specific phenotypes such as neuromelanin accumulation. Induced <span class="hlt">aging</span> in PD iPSC-derived dopamine neurons revealed disease phenotypes that require both <span class="hlt">aging</span> and genetic susceptibility, such as pronounced dendrite degeneration, progressive loss of tyrosine hydroxylase (TH) expression, and enlarged mitochondria or Lewy-body-precursor inclusions. Thus, our study suggests that progerin-induced <span class="hlt">aging</span> can be used to reveal late-onset <span class="hlt">age</span>-related disease features in hiPSC-based disease <span class="hlt">models</span>. PMID:24315443</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4153390','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4153390"><span id="translatedtitle">Human iPSC-based <span class="hlt">Modeling</span> of Late-Onset Disease via Progerin-induced <span class="hlt">Aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Miller, Justine D.; Ganat, Yosif M.; Kishinevsky, Sarah; Bowman, Robert L.; Liu, Becky; Tu, Edmund Y.; Mandal, Pankaj; Vera, Elsa; Shim, Jae-won; Kriks, Sonja; Taldone, Tony; Fusaki, Noemi; Tomishima, Mark J.; Krainc, Dimitri; Milner, Teresa A.; Rossi, Derrick J.; Studer, Lorenz</p> <p>2014-01-01</p> <p>Summary Reprogramming somatic cells to induced pluripotent stem cells (iPSCs), resets their identity back to an embryonic <span class="hlt">age</span>, and thus presents a significant hurdle for <span class="hlt">modeling</span> late-onset disorders. In this study, we describe a strategy for inducing <span class="hlt">aging</span>-related features in human iPSC-derived lineages and apply it to the <span class="hlt">modeling</span> of Parkinson’s disease (PD). Our approach involves expression of progerin, a truncated form of lamin A associated with premature <span class="hlt">aging</span>. We found that expression of progerin in iPSC-derived fibroblasts and neurons induces multiple <span class="hlt">aging</span>-related markers and characteristics, including dopamine-specific phenotypes such as neuromelanin accumulation. Induced <span class="hlt">aging</span> in PD-iPSC-derived dopamine neurons revealed disease phenotypes that require both <span class="hlt">aging</span> and genetic susceptibility, such as pronounced dendrite degeneration, progressive loss of tyrosine-hydroxylase (TH) expression and enlarged mitochondria or Lewy body-precursor inclusions. Thus, our study suggests that progerin-induced <span class="hlt">aging</span> can be used to reveal late-onset <span class="hlt">age</span>-related disease features in hiPSC-based disease <span class="hlt">models</span>. PMID:24315443</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26030468','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26030468"><span id="translatedtitle"><span class="hlt">Modelling</span> Anopheles gambiae s.s. Population Dynamics with Temperature- and <span class="hlt">Age</span>-Dependent Survival.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Christiansen-Jucht, Céline; Erguler, Kamil; Shek, Chee Yan; Basáñez, María-Gloria; Parham, Paul E</p> <p>2015-06-01</p> <p>Climate change and global warming are emerging as important threats to human health, particularly through the potential increase in vector- and water-borne diseases. Environmental variables are known to affect substantially the population dynamics and abundance of the poikilothermic vectors of disease, but the exact extent of this sensitivity is not well established. Focusing on malaria and its main vector in Africa, Anopheles gambiae sensu stricto, we present a set of novel mathematical <span class="hlt">models</span> of climate-driven mosquito population dynamics motivated by experimental data suggesting that in An. gambiae, mortality is temperature and <span class="hlt">age</span> dependent. We compared the performance of these <span class="hlt">models</span> to that of a "standard" <span class="hlt">model</span> ignoring <span class="hlt">age</span> dependence. We used a longitudinal dataset of vector abundance over 36 months in sub-Saharan Africa for comparison between <span class="hlt">models</span> that incorporate <span class="hlt">age</span> dependence and one that does not, and observe that <span class="hlt">age</span>-dependent <span class="hlt">models</span> consistently fitted the data better than the reference <span class="hlt">model</span>. This highlights that including <span class="hlt">age</span> dependence in the vector component of mosquito-borne disease <span class="hlt">models</span> may be important to predict more reliably disease transmission dynamics. Further data and studies are needed to enable improved fitting, leading to more accurate and informative <span class="hlt">model</span> predictions for the An. gambiae malaria vector as well as for other disease vectors. PMID:26030468</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4483682','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4483682"><span id="translatedtitle"><span class="hlt">Modelling</span> Anopheles gambiae s.s. Population Dynamics with Temperature- and <span class="hlt">Age</span>-Dependent Survival</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Christiansen-Jucht, Céline; Erguler, Kamil; Shek, Chee Yan; Basáñez, María-Gloria; Parham, Paul E.</p> <p>2015-01-01</p> <p>Climate change and global warming are emerging as important threats to human health, particularly through the potential increase in vector- and water-borne diseases. Environmental variables are known to affect substantially the population dynamics and abundance of the poikilothermic vectors of disease, but the exact extent of this sensitivity is not well established. Focusing on malaria and its main vector in Africa, Anopheles gambiae sensu stricto, we present a set of novel mathematical <span class="hlt">models</span> of climate-driven mosquito population dynamics motivated by experimental data suggesting that in An. gambiae, mortality is temperature and <span class="hlt">age</span> dependent. We compared the performance of these <span class="hlt">models</span> to that of a “standard” <span class="hlt">model</span> ignoring <span class="hlt">age</span> dependence. We used a longitudinal dataset of vector abundance over 36 months in sub-Saharan Africa for comparison between <span class="hlt">models</span> that incorporate <span class="hlt">age</span> dependence and one that does not, and observe that <span class="hlt">age</span>-dependent <span class="hlt">models</span> consistently fitted the data better than the reference <span class="hlt">model</span>. This highlights that including <span class="hlt">age</span> dependence in the vector component of mosquito-borne disease <span class="hlt">models</span> may be important to predict more reliably disease transmission dynamics. Further data and studies are needed to enable improved fitting, leading to more accurate and informative <span class="hlt">model</span> predictions for the An. gambiae malaria vector as well as for other disease vectors. PMID:26030468</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/929929','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/929929"><span id="translatedtitle">Atomistic <span class="hlt">Model</span> of Physical <span class="hlt">Ageing</span> in Se-rich As-Se Glasses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Golovchak,R.; Shpotyuk, O.; Kozdras, A.; Bureau, B.; Vlcek, M.; Ganjoo, A.; Jain, H.</p> <p>2007-01-01</p> <p>Thermal, optical, X-ray excited and magnetic methods were used to develop a microstructural <span class="hlt">model</span> of physical <span class="hlt">ageing</span> in Se-rich glasses. The glass composition As10Se90, possessing a typical cross-linked chain structure, was chosen as a <span class="hlt">model</span> object for the investigations. The effect of physical <span class="hlt">ageing</span> in this glass was revealed by differential scanning calorimetry, whereas the corresponding changes in its atomic arrangement were studied by extended X-ray absorption fine structure, Raman and solid-state 77Se nuclear magnetic resonance spectroscopy. Straightening-shrinkage processes are shown to be responsible for the physical <span class="hlt">ageing</span> in this Se-rich As-Se glass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4404219','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4404219"><span id="translatedtitle">A Dimensional Liability <span class="hlt">Model</span> of <span class="hlt">Age</span> Differences in Mental Disorder Prevalence: Evidence from a National Sample</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hoertel, Nicolas; McMahon, Kibby; Olfson, Mark; Wall, Melanie M.; Rodríguez-Fernández, Jorge Mario; Lemogne, Cédric; Limosin, Frédéric; Blanco, Carlos</p> <p>2015-01-01</p> <p>Recent theories have proposed a metastructure that organizes related mental disorders into broad dimensions of psychopathology (i.e., internalizing and externalizing dimensions). Prevalence rates of most mental disorders, when examined independently, are substantially lower in older than in younger adults, which may affect this metastructure. Within a nationally representative sample, the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; N = 43,093), we developed a dimensional liability <span class="hlt">model</span> of common psychiatric disorders to clarify whether <span class="hlt">aging</span> affects specific disorders or general dimensions of psychopathology. Significant <span class="hlt">age</span> differences existed across <span class="hlt">age</span> groups (18-24, 25-34, 35-44, 45-54, 55-64, 65-75 and 75+), such that older adults showed lower prevalence rates of most disorders compared to younger adults. We next investigated patterns of disorder comorbidity for past-year psychiatric disorders and found that a distress-fear-externalizing liability <span class="hlt">model</span> fit the data well. This <span class="hlt">model</span> was <span class="hlt">age</span>-group invariant and indicated that that the observed lower prevalence of mental disorders with advancing <span class="hlt">age</span> originates from lower average means on externalizing and internalizing liability dimensions. This unifying dimensional liability <span class="hlt">model</span> of <span class="hlt">age</span> and mental disorder comorbidity can help inform the role of <span class="hlt">aging</span> on mental disorder prevalence for research and intervention efforts, and service planning for the impending crisis in geriatric mental health. PMID:25858414</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25858414','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25858414"><span id="translatedtitle">A dimensional liability <span class="hlt">model</span> of <span class="hlt">age</span> differences in mental disorder prevalence: evidence from a national sample.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoertel, Nicolas; McMahon, Kibby; Olfson, Mark; Wall, Melanie M; Rodríguez-Fernández, Jorge Mario; Lemogne, Cédric; Limosin, Frédéric; Blanco, Carlos</p> <p>2015-05-01</p> <p>Recent theories have proposed a metastructure that organizes related mental disorders into broad dimensions of psychopathology (i.e., internalizing and externalizing dimensions). Prevalence rates of most mental disorders, when examined independently, are substantially lower in older than in younger adults, which may affect this metastructure. Within a nationally representative sample, the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; N = 43,093), we developed a dimensional liability <span class="hlt">model</span> of common psychiatric disorders to clarify whether <span class="hlt">aging</span> affects specific disorders or general dimensions of psychopathology. Significant <span class="hlt">age</span> differences existed across <span class="hlt">age</span> groups (18-24, 25-34, 35-44, 45-54, 55-64, 65-75 and 75+), such that older adults showed lower prevalence rates of most disorders compared to younger adults. We next investigated patterns of disorder comorbidity for past-year psychiatric disorders and found that a distress-fear-externalizing liability <span class="hlt">model</span> fit the data well. This <span class="hlt">model</span> was <span class="hlt">age</span>-group invariant and indicated that the observed lower prevalence of mental disorders with advancing <span class="hlt">age</span> originates from lower average means on externalizing and internalizing liability dimensions. This unifying dimensional liability <span class="hlt">model</span> of <span class="hlt">age</span> and mental disorder comorbidity can help inform the role of <span class="hlt">aging</span> on mental disorder prevalence for research and intervention efforts, and service planning for the impending crisis in geriatric mental health. PMID:25858414</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16938867','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16938867"><span id="translatedtitle">A Drosophila <span class="hlt">model</span> for <span class="hlt">age</span>-associated changes in sleep:wake cycles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koh, Kyunghee; Evans, Joshua M; Hendricks, Joan C; Sehgal, Amita</p> <p>2006-09-12</p> <p>One of the most consistent behavioral changes that occurs with <span class="hlt">age</span> in humans is the loss of sleep consolidation. This can be quite disruptive and yet little is known about its underlying basis. To better understand the effects of <span class="hlt">aging</span> on sleep:wake cycles, we sought to study this problem in Drosophila melanogaster, a powerful system for research on <span class="hlt">aging</span> and behavior. By assaying flies of different <span class="hlt">ages</span> as well as monitoring individual flies constantly over the course of their lifetime, we found that the strength of sleep:wake cycles decreased and that sleep became more fragmented with <span class="hlt">age</span> in Drosophila. These changes in sleep:wake cycles became faster or slower with manipulations of ambient temperature that decreased or increased lifespan, respectively, demonstrating that they are a function of physiological rather than chronological <span class="hlt">age</span>. The effect of temperature on lifespan was not mediated by changes in overall activity level or sleep amount. Flies treated with the oxidative stress-producing reagent paraquat showed a breakdown of sleep:wake cycles similar to that seen with <span class="hlt">aging</span>, leading us to propose that the accumulation of oxidative damage with <span class="hlt">age</span> contributes to the changes in rhythm and sleep. Together, these findings establish Drosophila as a valuable <span class="hlt">model</span> for studying <span class="hlt">age</span>-associated sleep fragmentation and breakdown of rhythm strength, and indicate that these changes in sleep:wake cycles are an integral part of the physiological <span class="hlt">aging</span> process. PMID:16938867</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26768998','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26768998"><span id="translatedtitle">Compensatory renal hypertrophy and the handling of an acute nephrotoxicant in a <span class="hlt">model</span> of <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oliveira, Cláudia S; Joshee, Lucy; Zalups, Rudolfs K; Bridges, Christy C</p> <p>2016-03-01</p> <p><span class="hlt">Aging</span> often results in progressive losses of functioning nephrons, which can lead to a significant reduction in overall renal function. Because of <span class="hlt">age</span>-related pathological changes, the remaining functional nephrons within <span class="hlt">aged</span> kidneys may be unable to fully counteract physiological and/or toxicological challenges. We hypothesized that when the total functional renal mass of <span class="hlt">aged</span> rats is reduced by 50%, the nephrons within the remnant kidney do not fully undergo the functional and physiological changes that are necessary to maintain normal fluid and solute homeostasis. We also tested the hypothesis that the disposition and handling of a nephrotoxicant are altered significantly in <span class="hlt">aged</span> kidneys following an acute, 50% reduction in functional renal mass. To test these hypotheses, we examined molecular indices of renal cellular hypertrophy and the disposition of inorganic mercury (Hg(2+)), a <span class="hlt">model</span> nephrotoxicant, in young control, young uninephrectomized (NPX), <span class="hlt">aged</span> control and <span class="hlt">aged</span> NPX Wistar rats. We found that the process of <span class="hlt">aging</span> reduces the ability of the remnant kidney to undergo compensatory renal growth. In addition, we found that an additional reduction in renal mass in <span class="hlt">aged</span> animals alters the disposition of Hg(2+) and potentially alters the risk of renal intoxication by this nephrotoxicant. To our knowledge, this study represents the first report of the handling of a nephrotoxicant in an <span class="hlt">aged</span> animal following a 50% reduction in functional renal mass. PMID:26768998</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvA..92e3827T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvA..92e3827T"><span id="translatedtitle"><span class="hlt">Absolute</span> optical instruments without spherical symmetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tyc, Tomáš; Dao, H. L.; Danner, Aaron J.</p> <p>2015-11-01</p> <p>Until now, the known set of <span class="hlt">absolute</span> optical instruments has been limited to those containing high levels of symmetry. Here, we demonstrate a method of mathematically constructing refractive index profiles that result in asymmetric <span class="hlt">absolute</span> optical instruments. The method is based on the analogy between geometrical optics and classical mechanics and employs Lagrangians that separate in Cartesian coordinates. In addition, our method can be used to construct the index profiles of most previously known <span class="hlt">absolute</span> optical instruments, as well as infinitely many different ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3215613','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3215613"><span id="translatedtitle"><span class="hlt">Age</span> equity in different <span class="hlt">models</span> of primary care practice in Ontario</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dahrouge, Simone; Hogg, William; Tuna, Meltem; Russell, Grant; Devlin, Rose Ann; Tugwell, Peter; Kristjansson, Elizabeth</p> <p>2011-01-01</p> <p>Abstract Objective To assess whether the <span class="hlt">model</span> of service delivery affects the equity of the care provided across <span class="hlt">age</span> groups. Design Cross-sectional study. Setting Ontario. Participants One hundred thirty-seven practices, including traditional fee-for-service practices, salaried community health centres (CHCs), and capitation-based family health networks and health service organizations. Main outcome measures To compare the quality of care across <span class="hlt">age</span> groups using multilevel linear or logistic regressions. Health service delivery measures and health promotion were assessed through patient surveys (N = 5111), which were based on the Primary Care Assessment Tool, and prevention and chronic disease management were assessed, based on Canadian recommendations for care, through chart abstraction (N = 4 108). Results Older individuals reported better health service delivery in all <span class="hlt">models</span>. This <span class="hlt">age</span> effect ranged from 1.9% to 5.7%, and was larger in the 2 capitation-based <span class="hlt">models</span>. Individuals <span class="hlt">aged</span> younger than 30 years attending CHCs had more features of disadvantage (ie, living below the poverty line and without high school education) and were more likely than older individuals to report discussing at least 1 health promotion subject at the index visit. These differences were deemed an appropriate response to greater needs in these younger individuals. The prevention score showed an <span class="hlt">age</span>-sex interaction in all <span class="hlt">models</span>, with adherence to recommended care dropping with <span class="hlt">age</span> for women. These results are largely attributable to the fact that maneuvers recommended for younger women are considerably more likely to be performed than other maneuvers. Chronic disease management scores showed an inverted U relationship with <span class="hlt">age</span> in fee-for-service practices, family health networks, and health service organizations but not in CHCs. Conclusion The salaried <span class="hlt">model</span> might have an organizational structure that is more conducive to providing appropriate care across <span class="hlt">age</span> groups. The thrust toward</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4697781','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4697781"><span id="translatedtitle">Verification of relationship <span class="hlt">model</span> between Korean new elderly class’s recovery resilience and productive <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cho, Gun-Sang; Kim, Dae-Sung; Yi, Eun-Surk</p> <p>2015-01-01</p> <p>The purpose of this study is to verification of relationship <span class="hlt">model</span> between Korean new elderly class’s recovery resilience and productive <span class="hlt">aging</span>. As of 2013, this study sampled preliminary elderly people in Gyeonggi-do and other provinces nationwide. Data from a total of effective 484 subjects was analyzed. The collected data was processed using the IBM SPSS 20.0 and AMOS 20.0, and underwent descriptive statistical analysis, confirmatory factor analysis, and structure <span class="hlt">model</span> verification. The path coefficient associated with <span class="hlt">model</span> fitness was examined. The standardization path coefficient between recovery resilience and productive <span class="hlt">aging</span> is β=0.975 (t=14.790), revealing a statistically significant positive effect. Thus, it was found that the proposed basic <span class="hlt">model</span> on the direct path of recovery resilience and productive <span class="hlt">aging</span> was fit for the <span class="hlt">model</span>. PMID:26730383</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27297494','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27297494"><span id="translatedtitle">Specific <span class="hlt">age</span>-related molecular alterations in the cerebellum of Down syndrome mouse <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Créau, Nicole; Cabet, Eva; Daubigney, Fabrice; Souchet, Benoit; Bennaï, Soumia; Delabar, Jean</p> <p>2016-09-01</p> <p>Down syndrome, or trisomy 21, has been <span class="hlt">modeled</span> with various trisomic and transgenic mice to help understand the consequences of an altered gene dosage in brain development and function. Though Down syndrome has been associated with premature <span class="hlt">aging</span>, little is known about the molecular and cellular alterations that target brain function. To help identify alterations at specific <span class="hlt">ages</span>, we analyzed the cerebellum of Ts1Cje mice, trisomic for 77 HSA21 orthologs, at three <span class="hlt">ages</span>-young (4 months), middle-<span class="hlt">age</span> (12 months), and old (17 months)-compared to <span class="hlt">age</span>-matched controls. Quantification of neuronal and glial markers (n=11) revealed increases in GFAP, with an <span class="hlt">age</span> effect, and S100B, with <span class="hlt">age</span> and genotype effects. The genotype effect on S100B with <span class="hlt">age</span> was unexpected as Ts1Cje has only two copies of the S100b gene. Interestingly, the different increase in GFAP observed between Ts1Cje (trisomic segment includes Pcp4 gene) and controls was magnified in TgPCP4 mice (1 extra copy of the human PCP4 gene) at the same <span class="hlt">age</span>. S100B increase was not found in the TgPCP4 confirming a difference of regulation with <span class="hlt">aging</span> for GFAP and S100B and excluding the calcium signaling regulator, Pcp4, as a potential candidate for increase of S100B in the Ts1Cje. To understand these differences, comparison of GFAP and S100B immunostainings at young and middle-<span class="hlt">age</span> were performed. Immunohistochemical detection of differences in GFAP and S100B localization with <span class="hlt">aging</span> implicate S100B+ oligodendrocytes as a new phenotypic target in this specific <span class="hlt">aging</span> process. PMID:27297494</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26500044','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26500044"><span id="translatedtitle">Chronic and progressive Parkinson's disease MPTP <span class="hlt">model</span> in adult and <span class="hlt">aged</span> mice.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Muñoz-Manchado, Ana B; Villadiego, Javier; Romo-Madero, Sonia; Suárez-Luna, Nela; Bermejo-Navas, Alfonso; Rodríguez-Gómez, José A; Garrido-Gil, Pablo; Labandeira-García, José L; Echevarría, Miriam; López-Barneo, José; Toledo-Aral, Juan J</p> <p>2016-01-01</p> <p>Despite the different animal <span class="hlt">models</span> of Parkinson's disease developed during the last years, they still present limitations <span class="hlt">modelling</span> the slow and progressive process of neurodegeneration. Here, we undertook a histological, neurochemical and behavioural analysis of a new chronic parkinsonian mouse <span class="hlt">model</span> generated by the subcutaneous administration of low doses of MPTP (20 mg/kg, 3 times per week) for 3 months, using both young adult and <span class="hlt">aged</span> mice. The MPTP-induced nigrostriatal neurodegeneration was progressive and was accompanied by a decrease in striatal dopamine levels and motor impairment. We also demonstrated the characteristic neuroinflammatory changes (microglial activation and astrogliosis) associated with the neurodegenerative process. <span class="hlt">Aged</span> animals showed both a faster time course of neurodegeneration and an altered neuroinflammatory response. The long-term systemic application of low MPTP doses did not induce any increase in mortality in either young adult or <span class="hlt">aged</span> mice and better resembles the slow evolution of the neurodegenerative process. This treatment could be useful to <span class="hlt">model</span> different stages of Parkinson's disease, providing a better understanding of the pathophysiology of the disease and facilitating the testing of both protective and restorative treatments. Here, we show a new chronic and progressive parkinsonian mouse <span class="hlt">model</span>, in young and <span class="hlt">aged</span> mice. This <span class="hlt">model</span> produces a stable degeneration of the dopaminergic nigrostriatal pathway, continuous neuroinflammatory reaction and motor deficits. <span class="hlt">Aged</span> animals showed a faster neurodegeneration and an altered neuroinflammatory response. This treatment could be useful to <span class="hlt">model</span> different stages of PD and to test both protective and restorative therapeutic approaches. PMID:26500044</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140001056','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140001056"><span id="translatedtitle">Evaluation of the <span class="hlt">Absolute</span> Regional Temperature Potential</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shindell, D. T.</p> <p>2012-01-01</p> <p>The <span class="hlt">Absolute</span> Regional Temperature Potential (ARTP) is one of the few climate metrics that provides estimates of impacts at a sub-global scale. The ARTP presented here gives the time-dependent temperature response in four latitude bands (90-28degS, 28degS-28degN, 28-60degN and 60-90degN) as a function of emissions based on the forcing in those bands caused by the emissions. It is based on a large set of simulations performed with a single atmosphere-ocean climate <span class="hlt">model</span> to derive regional forcing/response relationships. Here I evaluate the robustness of those relationships using the forcing/response portion of the ARTP to estimate regional temperature responses to the historic aerosol forcing in three independent climate <span class="hlt">models</span>. These ARTP results are in good accord with the actual responses in those <span class="hlt">models</span>. Nearly all ARTP estimates fall within +/-20%of the actual responses, though there are some exceptions for 90-28degS and the Arctic, and in the latter the ARTP may vary with forcing agent. However, for the tropics and the Northern Hemisphere mid-latitudes in particular, the +/-20% range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 39-45% and 9-39% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-scale latitude bands and land areas within those bands to inhomogeneous radiative forcing and thus potentially to emissions as well. Hence this metric could allow rapid evaluation of the effects of emissions policies at a finer scale than global metrics without requiring use of a full climate <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.G31A0939M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.G31A0939M&link_type=ABSTRACT"><span id="translatedtitle">GNSS <span class="hlt">Absolute</span> Antenna Calibration at the National Geodetic Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mader, G. L.; Bilich, A. L.; Geoghegan, C.</p> <p>2011-12-01</p> <p>Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna <span class="hlt">models</span> and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these <span class="hlt">models</span> into analysis software. To help meet the needs of the high-precision GNSS community, the National Geodetic Survey (NGS) now operates an <span class="hlt">absolute</span> antenna calibration facility. Located in Corbin, Virginia, this facility uses field measurements and actual GNSS satellite signals to quantitatively determine the carrier phase advance/delay introduced by the antenna element. The NGS facility was built to serve traditional NGS constituents such as the surveying and geodesy communities, however calibration services are open and available to all GNSS users as the calibration schedule permits. All phase center patterns computed by this facility will be publicly available and disseminated in both the ANTEX and NGS formats. We describe the NGS calibration facility, and discuss the observation <span class="hlt">models</span> and strategy currently used to generate NGS <span class="hlt">absolute</span> calibrations. We demonstrate that NGS <span class="hlt">absolute</span> phase center variation (PCV) patterns are consistent with published values determined by other <span class="hlt">absolute</span> antenna calibration facilities, and compare <span class="hlt">absolute</span> calibrations to the traditional NGS relative calibrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...586A.155A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...586A.155A"><span id="translatedtitle"><span class="hlt">Absolute</span> magnitudes and phase coefficients of trans-Neptunian objects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alvarez-Candal, A.; Pinilla-Alonso, N.; Ortiz, J. L.; Duffard, R.; Morales, N.; Santos-Sanz, P.; Thirouin, A.; Silva, J. S.</p> <p>2016-02-01</p> <p>Context. Accurate measurements of diameters of trans-Neptunian objects (TNOs) are extremely difficult to obtain. Thermal <span class="hlt">modeling</span> can provide good results, but accurate <span class="hlt">absolute</span> magnitudes are needed to constrain the thermal <span class="hlt">models</span> and derive diameters and geometric albedos. The <span class="hlt">absolute</span> magnitude, HV, is defined as the magnitude of the object reduced to unit helio- and geocentric distances and a zero solar phase angle and is determined using phase curves. Phase coefficients can also be obtained from phase curves. These are related to surface properties, but only few are known. Aims: Our objective is to measure accurate V-band <span class="hlt">absolute</span> magnitudes and phase coefficients for a sample of TNOs, many of which have been observed and <span class="hlt">modeled</span> within the program "TNOs are cool", which is one of the Herschel Space Observatory key projects. Methods: We observed 56 objects using the V and R filters. These data, along with those available in the literature, were used to obtain phase curves and measure V-band <span class="hlt">absolute</span> magnitudes and phase coefficients by assuming a linear trend of the phase curves and considering a magnitude variability that is due to the rotational light-curve. Results: We obtained 237 new magnitudes for the 56 objects, six of which were without previously reported measurements. Including the data from the literature, we report a total of 110 <span class="hlt">absolute</span> magnitudes with their respective phase coefficients. The average value of HV is 6.39, bracketed by a minimum of 14.60 and a maximum of -1.12. For the phase coefficients we report a median value of 0.10 mag per degree and a very large dispersion, ranging from -0.88 up to 1.35 mag per degree.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4598651','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4598651"><span id="translatedtitle">Markov Chain-Like Quantum Biological <span class="hlt">Modeling</span> of Mutations, <span class="hlt">Aging</span>, and Evolution</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Djordjevic, Ivan B.</p> <p>2015-01-01</p> <p>Recent evidence suggests that quantum mechanics is relevant in photosynthesis, magnetoreception, enzymatic catalytic reactions, olfactory reception, photoreception, genetics, electron-transfer in proteins, and evolution; to mention few. In our recent paper published in Life, we have derived the operator-sum representation of a biological channel based on codon basekets, and determined the quantum channel <span class="hlt">model</span> suitable for study of the quantum biological channel capacity. However, this <span class="hlt">model</span> is essentially memoryless and it is not able to properly <span class="hlt">model</span> the propagation of mutation errors in time, the process of <span class="hlt">aging</span>, and evolution of genetic information through generations. To solve for these problems, we propose novel quantum mechanical <span class="hlt">models</span> to accurately describe the process of creation spontaneous, induced, and adaptive mutations and their propagation in time. Different biological channel <span class="hlt">models</span> with memory, proposed in this paper, include: (i) Markovian classical <span class="hlt">model</span>, (ii) Markovian-like quantum <span class="hlt">model</span>, and (iii) hybrid quantum-classical <span class="hlt">model</span>. We then apply these <span class="hlt">models</span> in a study of <span class="hlt">aging</span> and evolution of quantum biological channel capacity through generations. We also discuss key differences of these <span class="hlt">models</span> with respect to a multilevel symmetric channel-based Markovian <span class="hlt">model</span> and a Kimura <span class="hlt">model</span>-based Markovian process. These <span class="hlt">models</span> are quite general and applicable to many open problems in biology, not only biological channel capacity, which is the main focus of the paper. We will show that the famous quantum Master equation approach, commonly used to describe different biological processes, is just the first-order approximation of the proposed quantum Markov chain-like <span class="hlt">model</span>, when the observation interval tends to zero. One of the important implications of this <span class="hlt">model</span> is that the <span class="hlt">aging</span> phenotype becomes determined by different underlying transition probabilities in both programmed and random (damage) Markov chain-like <span class="hlt">models</span> of <span class="hlt">aging</span>, which are mutually</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26330290','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26330290"><span id="translatedtitle">Hutchinson-Gilford progeria syndrome as a <span class="hlt">model</span> for vascular <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brassard, Jonathan A; Fekete, Natalie; Garnier, Alain; Hoesli, Corinne A</p> <p>2016-02-01</p> <p>Hutchinson-Gilford progeria syndrome (HGPS) is a premature <span class="hlt">aging</span> disorder caused by a de novo genetic mutation that leads to the accumulation of a splicing isoform of lamin A termed progerin. Progerin expression alters the organization of the nuclear lamina and chromatin. The life expectancy of HGPS patients is severely reduced due to critical cardiovascular defects. Progerin also accumulates in an <span class="hlt">age</span>-dependent manner in the vascular cells of adults that do not carry genetic mutations associated with HGPS. The molecular mechanisms that lead to vascular dysfunction in HGPS may therefore also play a role in vascular <span class="hlt">aging</span>. The vascular phenotypic and molecular changes observed in HGPS are strikingly similar to those seen with <span class="hlt">age</span>, including increased senescence, altered mechanotransduction and stem cell exhaustion. This article discusses the similarities and differences between <span class="hlt">age</span>-dependent and HGPS-related vascular <span class="hlt">aging</span> to highlight the relevance of HGPS as a <span class="hlt">model</span> for vascular <span class="hlt">aging</span>. Induced pluripotent stem cells derived from HGPS patients are suggested as an attractive <span class="hlt">model</span> to study vascular <span class="hlt">aging</span> in order to develop novel approaches to treat cardiovascular disease. PMID:26330290</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22019846','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22019846"><span id="translatedtitle">Down syndrome as a <span class="hlt">model</span> of DNA polymerase beta haploinsufficiency and accelerated <span class="hlt">aging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Patterson, David; Cabelof, Diane C</p> <p>2012-04-01</p> <p>Down syndrome is a condition of intellectual disability characterized by accelerated <span class="hlt">aging</span>. As with other <span class="hlt">aging</span> syndromes, evidence accumulated over the past several decades points to a DNA repair defect inherent in Down syndrome. This evidence has led us to suggest that Down syndrome results in reduced DNA base excision repair (BER) capacity, and that this contributes to the genomic instability and the <span class="hlt">aging</span> phenotype of Down syndrome. We propose important roles for microRNA and/or folate metabolism and oxidative stress in the dysregulation of BER in Down syndrome. Further, we suggest these pathways are involved in the leukemogenesis of Down syndrome. We have reviewed the role of BER in the processing of oxidative stress, and the impact of folate depletion on BER capacity. Further, we have reviewed the role that loss of BER, specifically DNA polymerase beta, plays in accelerating the rate of <span class="hlt">aging</span>. Like that seen in the DNA polymerase beta heterozygous mouse, the <span class="hlt">aging</span> phenotype of Down syndrome is subtle, unlike the <span class="hlt">aging</span> phenotypes seen in the classical progeroid syndromes and mouse <span class="hlt">models</span> of <span class="hlt">aging</span>. As such, Down syndrome may provide a <span class="hlt">model</span> for elucidating some of the basic mechanisms of <span class="hlt">aging</span>. PMID:22019846</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=organic+AND+carbon&pg=5&id=EJ288694','ERIC'); return false;" href="http://eric.ed.gov/?q=organic+AND+carbon&pg=5&id=EJ288694"><span id="translatedtitle">A New Gimmick for Assigning <span class="hlt">Absolute</span> Configuration.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ayorinde, F. O.</p> <p>1983-01-01</p> <p>A five-step procedure is provided to help students in making the assignment <span class="hlt">absolute</span> configuration less bothersome. Examples for both single (2-butanol) and multi-chiral carbon (3-chloro-2-butanol) molecules are included. (JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6760D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6760D"><span id="translatedtitle">Using remotely-sensed multispectral imagery to build <span class="hlt">age</span> <span class="hlt">models</span> for alluvial fan surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Arcy, Mitch; Mason, Philippa J.; Roda Boluda, Duna C.; Whittaker, Alexander C.; Lewis, James</p> <p>2016-04-01</p> <p>Accurate exposure <span class="hlt">age</span> <span class="hlt">models</span> are essential for much geomorphological field research, and generally depend on laboratory analyses such as radiocarbon, cosmogenic nuclide, or luminescence techniques. These approaches continue to revolutionise geomorphology, however they cannot be deployed remotely or in situ in the field. Therefore other methods are still needed for producing preliminary <span class="hlt">age</span> <span class="hlt">models</span>, performing relative dating of surfaces, or selecting sampling sites for the laboratory analyses above. With the widespread availability of detailed multispectral imagery, a promising approach is to use remotely-sensed data to discriminate surfaces with different <span class="hlt">ages</span>. Here, we use new Landsat 8 Operational Land Imager (OLI) multispectral imagery to characterise the reflectance of 35 alluvial fan surfaces in the semi-arid Owens Valley, California. Alluvial fans are useful landforms to date, as they are widely used to study the effects of tectonics, climate and sediment transport processes on source-to-sink sedimentation. Our target fan surfaces have all been mapped in detail in the field, and have well-constrained exposure <span class="hlt">ages</span> ranging from modern to ~ 125 ka measured using a high density of 10Be cosmogenic nuclide samples. Despite all having similar granitic compositions, the spectral properties of these surfaces vary systematically with their exposure <span class="hlt">ages</span>. Older surfaces demonstrate a predictable shift in reflectance across the visible and short-wave infrared spectrum. Simple calculations, such as the brightness ratios of different wavelengths, generate sensitive power law relationships with exposure <span class="hlt">age</span> that depend on post-depositional alteration processes affecting these surfaces. We investigate what these processes might be in this dryland location, and evaluate the potential for using remotely-sensed multispectral imagery for developing surface <span class="hlt">age</span> <span class="hlt">models</span>. The ability to remotely sense relative exposure <span class="hlt">ages</span> has useful implications for preliminary mapping, selecting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4760935','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4760935"><span id="translatedtitle">Depot-Specific Changes in Fat Metabolism with <span class="hlt">Aging</span> in a Type 2 Diabetic Animal <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Park, Se Eun; Choi, Jung Mook; Chang, Eugene; Rhee, Eun-Jung; Lee, Won-Young; Oh, Ki Won; Park, Sung Woo; Kang, Eun Seok; Lee, Hyun Chul</p> <p>2016-01-01</p> <p>Visceral fat accretion is a hallmark of <span class="hlt">aging</span> and is associated with <span class="hlt">aging</span>-induced metabolic dysfunction. PPARγ agonist was reported to improve insulin sensitivity by redistributing fat from visceral fat to subcutaneous fat. The purpose of this study was to investigate the underlying mechanisms by which <span class="hlt">aging</span> affects adipose tissue remodeling in a type 2 diabetic animal <span class="hlt">model</span> and through which PPARγ activation modulates <span class="hlt">aging</span>-related fat tissue distribution. At the <span class="hlt">ages</span> of 21, 31 and 43 weeks, OLETF rats as an animal <span class="hlt">model</span> of type 2 diabetes were evaluated for <span class="hlt">aging</span>-related effects on adipose tissue metabolism in subcutaneous and visceral fat depots. During <span class="hlt">aging</span>, the ratio of visceral fat weight to subcutaneous fat weight (V/S ratio) increased. <span class="hlt">Aging</span> significantly increased the mRNA expression of genes involved in lipogenesis such as lipoprotein lipase, fatty acid binding protein aP2, lipin 1, and diacylglycerol acyltransferase 1, which were more prominent in visceral fat than subcutaneous fat. The mRNA expression of adipose triglyceride lipase, which is involved in basal lipolysis and fatty acid recycling, was also increased, more in visceral fat compared to subcutaneous fat during <span class="hlt">aging</span>. The mRNA levels of the genes associated with lipid oxidation were increased, whereas the mRNA levels of genes associated with energy expenditure showed no significant change during <span class="hlt">aging</span>. PPARγ agonist treatment in OLETF rats resulted in fat redistribution with a decreasing V/S ratio and improved glucose intolerance. The genes involved in lipogenesis decreased in visceral fat of the PPARγ agonist-treated rats. During <span class="hlt">aging</span>, fat distribution was changed by stimulating lipid uptake and esterification in visceral fat rather than subcutaneous fat, and by altering the lipid oxidation. PMID:26894429</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26894429','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26894429"><span id="translatedtitle">Depot-Specific Changes in Fat Metabolism with <span class="hlt">Aging</span> in a Type 2 Diabetic Animal <span class="hlt">Model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Se Eun; Park, Cheol-Young; Choi, Jung Mook; Chang, Eugene; Rhee, Eun-Jung; Lee, Won-Young; Oh, Ki Won; Park, Sung Woo; Kang, Eun Seok; Lee, Hyun Chul; Cha, Bong Soo</p> <p>2016-01-01</p> <p>Visceral fat accretion is a hallmark of <span class="hlt">aging</span> and is associated with <span class="hlt">aging</span>-induced metabolic dysfunction. PPARγ agonist was reported to improve insulin sensitivity by redistributing fat from visceral fat to subcutaneous fat. The purpose of this study was to investigate the underlying mechanisms by which <span class="hlt">aging</span> affects adipose tissue remodeling in a type 2 diabetic animal <span class="hlt">model</span> and through which PPARγ activation modulates <span class="hlt">aging</span>-related fat tissue distribution. At the <span class="hlt">ages</span> of 21, 31 and 43 weeks, OLETF rats as an animal <span class="hlt">model</span> of type 2 diabetes were evaluated for <span class="hlt">aging</span>-related effects on adipose tissue metabolism in subcutaneous and visceral fat depots. During <span class="hlt">aging</span>, the ratio of visceral fat weight to subcutaneous fat weight (V/S ratio) increased. <span class="hlt">Aging</span> significantly increased the mRNA expression of genes involved in lipogenesis such as lipoprotein lipase, fatty acid binding protein aP2, lipin 1, and diacylglycerol acyltransferase 1, which were more prominent in visceral fat than subcutaneous fat. The mRNA expression of adipose triglyceride lipase, which is involved in basal lipolysis and fatty acid recycling, was also increased, more in visceral fat compared to subcutaneous fat during <span class="hlt">aging</span>. The mRNA levels of the genes associated with lipid oxidation were increased, whereas the mRNA levels of genes associated with energy expenditure showed no significant change during <span class="hlt">aging</span>. PPARγ agonist treatment in OLETF rats resulted in fat redistribution with a decreasing V/S ratio and improved glucose intolerance. The genes involved in lipogenesis decreased in visceral fat of the PPARγ agonist-treated rats. During <span class="hlt">aging</span>, fat distribution was changed by stimulating lipid uptake and esterification in visceral fat rather than subcutaneous fat, and by altering the lipid oxidation. PMID:26894429</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://dceg.cancer.gov/tools/risk-assessment/bcrasasmacro','NCI'); return false;" href="http://dceg.cancer.gov/tools/risk-assessment/bcrasasmacro"><span id="translatedtitle">Breast Cancer Risk Assessment SAS Macro (Gail <span class="hlt">Model</span>)</span></a></p> <p><a target="_blank" href="http://www.cancer.gov">Cancer.gov</a></p> <p></p> <p></p> <p>A SAS macro (commonly referred to as the Gail <span class="hlt">Model</span>) that projects <span class="hlt">absolute</span> risk of invasive breast cancer according to NCI’s Breast Cancer Risk Assessment Tool (BCRAT) algorithm for specified race/ethnic groups and <span class="hlt">age</span> intervals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25520096','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25520096"><span id="translatedtitle"><span class="hlt">Modeling</span> <span class="hlt">age</span>-specific cancer incidences using logistic growth equations: implications for data collection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Xing-Rong; Feng, Rui; Chai, Jing; Cheng, Jing; Wang, De-Bin</p> <p>2014-01-01</p> <p>Large scale secular registry or surveillance systems have been accumulating vast data that allow mathematical <span class="hlt">modeling</span> of cancer incidence and mortality rates. Most contemporary <span class="hlt">models</span> in this regard use time series and APC (<span class="hlt">age</span>-period-cohort) methods and focus primarily on predicting or analyzing cancer epidemiology with little attention being paid to implications for designing cancer registry, surveillance or evaluation initiatives. This research <span class="hlt">models</span> <span class="hlt">age</span>-specific cancer incidence rates using logistic growth equations and explores their performance under different scenarios of data completeness in the hope of deriving clues for reshaping relevant data collection. The study used China Cancer Registry Report 2012 as the data source. It employed 3-parameter logistic growth equations and <span class="hlt">modeled</span> the <span class="hlt">age</span>-specific incidence rates of all and the top 10 cancers presented in the registry report. The study performed 3 types of <span class="hlt">modeling</span>, namely full <span class="hlt">age</span>-span by fitting, multiple 5-year- segment fitting and single-segment fitting. Measurement of <span class="hlt">model</span> performance adopted adjusted goodness of fit that combines sum of squred residuals and relative errors. Both <span class="hlt">model</span> simulation and performance evalation utilized self-developed algorithms programed using C# languade and MS Visual Studio 2008. For <span class="hlt">models</span> built upon full <span class="hlt">age</span>-span data, predicted <span class="hlt">age</span>-specific cancer incidence rates fitted very well with observed values for most (except cervical and breast) cancers with estimated goodness of fit (Rs) being over 0.96. When a given cancer is concerned, the R valuae of the logistic growth <span class="hlt">model</span> derived using observed data from urban residents was greater than or at least equal to that of the same <span class="hlt">model</span> built on data from rural people. For <span class="hlt">models</span> based on multiple-5-year-segment data, the Rs remained fairly high (over 0.89) until 3-fourths of the data segments were excluded. For <span class="hlt">models</span> using a fixed length single-segment of observed data, the older the <span class="hlt">age</span> covered by the corresponding</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2788179','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2788179"><span id="translatedtitle">Antioxidant effect of garlic and <span class="hlt">aged</span> black garlic in animal <span class="hlt">model</span> of type 2 diabetes mellitus</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Young-Min; Gweon, Oh-Cheon; Seo, Yeong-Ju; Im, Jieun; Kang, Min-Jung; Kim, Myo-Jeong</p> <p>2009-01-01</p> <p>Hyperglycemia in the diabetic state increases oxidative stress and antioxidant therapy can be strongly correlated with decreased risks for diabetic complications. The purpose of this study is to determine antioxidant effect of garlic and <span class="hlt">aged</span> black garlic in animal <span class="hlt">model</span> of type 2 diabetes. The antioxidant activity of garlic and <span class="hlt">aged</span> black garlic was measured as the activity in scavenging free radicals by the trolox equivalent antioxidant capacity (TEAC) assay. Three week-old db/db mice were fed AIN-93G diet or diet containing 5% freeze-dried garlic or <span class="hlt">aged</span> black garlic for 7 weeks after 1 week of adaptation. Hepatic levels of lipid peroxides and activities of antioxidant enzymes were measured. TEAC values of garlic and <span class="hlt">aged</span> black garlic were 13.3 ± 0.5 and 59.2 ± 0.8 µmol/g wet weight, respectively. Consumption of <span class="hlt">aged</span> black garlic significantly decreased hepatic thiobarbituric acid reactive substances (TBARS) level compared with the garlic group which showed lower TBARS level than control group (p<0.05). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of garlic and <span class="hlt">aged</span> black garlic group were significantly elevated compared to the control group. Catalase (CAT) activity of <span class="hlt">aged</span> black garlic group was increased compared with the control group. These results show that <span class="hlt">aged</span> black garlic exerts stronger antioxidant activity than garlic in vitro and in vivo, suggesting garlic and <span class="hlt">aged</span> black garlic, to a greater extent, could be useful in preventing diabetic complications. PMID:20016716</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3404643','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3404643"><span id="translatedtitle">Increasing pulse wave velocity in a realistic cardiovascular <span class="hlt">model</span> does not increase pulse pressure with <span class="hlt">age</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mohiuddin, Mohammad W.; Rihani, Ryan J.; Laine, Glen A.</p> <p>2012-01-01</p> <p>The mechanism of the well-documented increase in aortic pulse pressure (PP) with <span class="hlt">age</span> is disputed. Investigators assuming a classical windkessel <span class="hlt">model</span> believe that increases in PP arise from decreases in total arterial compliance (Ctot) and increases in total peripheral resistance (Rtot) with <span class="hlt">age</span>. Investigators assuming a more sophisticated pulse transmission <span class="hlt">model</span> believe PP rises because increases in pulse wave velocity (cph) make the reflected pressure wave arrive earlier, augmenting systolic pressure. It has recently been shown, however, that increases in cph do not have a commensurate effect on the timing of the reflected wave. We therefore used a validated, large-scale, human arterial system <span class="hlt">model</span> that includes realistic pulse wave transmission to determine whether increases in cph cause increased PP with <span class="hlt">age</span>. First, we made the realistic arterial system <span class="hlt">model</span> <span class="hlt">age</span> dependent by altering cardiac output (CO), Rtot, Ctot, and cph to mimic the reported changes in these parameters from <span class="hlt">age</span> 30 to 70. Then, cph was theoretically maintained constant, while Ctot, Rtot, and CO were altered. The predicted increase in PP with <span class="hlt">age</span> was similar to the observed increase in PP. In a complementary approach, Ctot, Rtot, and CO were theoretically maintained constant, and cph was increased. The predicted increase in PP was negligible. We found that increases in cph have a limited effect on the timing of the reflected wave but cause the system to degenerate into a windkessel. Changes in PP can therefore be attributed to a decrease in Ctot. PMID:22561301</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H53F1490E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H53F1490E"><span id="translatedtitle">Realistic <span class="hlt">modeling</span> of environmental tracer migration and composite <span class="hlt">age</span> distributions in a pine beetle impacted watershed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Engdahl, N. B.; Maxwell, R. M.</p> <p>2013-12-01</p> <p>Descriptions of <span class="hlt">age</span> in hydrologic systems are often limited to the residence time in the surface water system or the subsurface with little consideration of the interaction between the two, or the different ways geochemical tracers are altered in each domain. Understanding the way tracer concentrations change in each domain is essential to accurate estimation of <span class="hlt">age</span>, but few <span class="hlt">models</span> have explicitly <span class="hlt">modeled</span> the fully coupled system or considered distributions of <span class="hlt">age</span>. This work presents a numerical laboratory that is specifically designed to investigate composite <span class="hlt">age</span> distributions (CADs) and their connections to tracer concentrations. The CAD is defined here as the combination of the residence time distributions for surface flows, vadose zone, and groundwater systems, providing an accounting for the total time a discrete fluid parcel has spent within the integrated hydrologic system. CADs are generated by particle tracking through a fully integrated flow <span class="hlt">model</span> and it is straight forward to realistically simulate the transport of environmental tracers such as 85-Krypton and 39-Argon that can be used for estimating water <span class="hlt">ages</span>. This framework allows explicit <span class="hlt">modeling</span> of the different processes in each domain that affect tracer concentrations including the mixing of different source waters, partial equilibrium with the atmosphere through the vadose zone, evaporative enrichment in surface flows, and diffusive fractionation in the subsurface. Transient forcings, such as seasonal or daily variations in precipitation, can also be simulated and the effects of this transience on concentrations and <span class="hlt">age</span> distributions can easily be investigated. The <span class="hlt">model</span> domain used to demonstrate these tools is based on a well-defined watershed within Rocky Mountain National Park. The mountain pine beetle has devastated the park's forests and the massive tree-kill has begun to affect the quality and distribution of the water resources. Accurate <span class="hlt">modeling</span> of the CADs in the park is a crucial step</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=70299&keyword=anatomical&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77122441&CFTOKEN=63605673','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=70299&keyword=anatomical&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77122441&CFTOKEN=63605673"><span id="translatedtitle">METHODS FOR <span class="hlt">MODELING</span> PARTICLE DEPOSITION AS A FUNCTION OF <span class="hlt">AGE</span>. (R827352C004)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p><p>The purpose of this paper is to review the application of mathematical <span class="hlt">models</span> of inhaled particle deposition to people of various <span class="hlt">ages</span>. The basic considerations of aerosol physics, biological characteristics and <span class="hlt">model</span> structure are presented along with limitations inherent in ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=sutton%2c+kevin&id=EJ628431','ERIC'); return false;" href="http://eric.ed.gov/?q=sutton%2c+kevin&id=EJ628431"><span id="translatedtitle">Multilevel Risk <span class="hlt">Models</span> for Retrospective <span class="hlt">Age</span>-of-Onset Data: School Children's First Cigarette.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Pickles, Andrew; Pickering, Kevin; Taylor, Colin; Sutton, Stephen; Yang, Shuying</p> <p>2001-01-01</p> <p>Describes a random effects discrete time survival <span class="hlt">model</span> that addresses problems of measurement error and sample design complexities. Demonstrates the effectiveness of the <span class="hlt">model</span> in an analysis of retrospective report data on the <span class="hlt">age</span> of onset of smoking from two cross-sectional school-based studies. (JPB)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=relegation&pg=2&id=EJ351264','ERIC'); return false;" href="http://eric.ed.gov/?q=relegation&pg=2&id=EJ351264"><span id="translatedtitle">A Third Note on <span class="hlt">Ageing</span> in a Library Circulation <span class="hlt">Model</span>: Applications to Future Use and Relegation.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Burrell, Quentin L.</p> <p>1987-01-01</p> <p>Describes a circulation <span class="hlt">model</span> for academic research libraries which uses the mixed Poisson <span class="hlt">model</span>, incorporating <span class="hlt">ageing</span> of library materials, to predict future use of monographs and to suggest weeding procedures based on frequency of circulation. Longitudinal studies are examined and statistical details are appended. (Author/LRW)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GMDD....6.4447F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GMDD....6.4447F"><span id="translatedtitle">The Cache la Poudre river basin snow water equivalent <span class="hlt">modeling</span> with New<span class="hlt">Age</span>-JGrass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Formetta, G.; Kampf, S. K.; David, O.; Rigon, R.</p> <p>2013-08-01</p> <p>The paper presents a snow water equivalent <span class="hlt">model</span> as part of the hydrological <span class="hlt">modeling</span> system New<span class="hlt">Age</span>-JGrass. The <span class="hlt">model</span> take in account of the main physical processes influencing the snow melting (precipitation form separation, melting and freezing <span class="hlt">modeling</span>) coupled with the snowpack mass conservation equation. The snow melting depends not only on the air temperature but also on the radiation received by the pixel. The <span class="hlt">model</span> is perfectly integrated in the New<span class="hlt">Age</span>-JGrass <span class="hlt">modeling</span> system and uses many of its components such as shortwave radiation balance, krigings and automatic calibration algorithms. As all the New<span class="hlt">Age</span>-JGrass components, the presented <span class="hlt">model</span> can be executed both in raster and in vector mode and the simulation time step can be daily, hourly or sub-hourly as the user needs. The <span class="hlt">model</span> is applied on the Cache la Poudre river basin (CO, USA). Three are the applications presented in the paper. Firstly, the simulation of snow water equivalent in three different measurement stations is performed. <span class="hlt">Model</span> parameters are calibrated and <span class="hlt">model</span> performances are quantitatively computed by comparing simulated and measured snow water equivalent time series. Indices of goodness of fit such as Kling-Gupta Efficiency, Index of Agreement and Percentage Bias are computed. Secondly, the representativeness of the <span class="hlt">model</span> parameters in different locations is discussed. Finally a raster mode application is performed: snow water equilvalent maps on the whole Cache la Poudre river are computed. In all the applications the <span class="hlt">model</span> performance are satisfactory in term of goodness of fitting measured snow water equivalent time series. The integration of the <span class="hlt">model</span> in the New<span class="hlt">Age</span>-JGrass system allows the used to o enjoy all the component of the system: input data computation, output maps visualizetion in the GIS JGrass, <span class="hlt">model</span> parameters automatic calibration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/973702','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/973702"><span id="translatedtitle">Estimating Black Carbon <span class="hlt">Aging</span> Time-Scales with a Particle-Resolved Aerosol <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Riemer, Nicole; West, Matt; Zaveri, Rahul A.; Easter, Richard C.</p> <p>2010-01-13</p> <p>Understanding the <span class="hlt">aging</span> process of aerosol particles is important for assessing their chemical reactivity, cloud condensation nuclei activity, radiative properties and health impacts. In this study we investigate the <span class="hlt">aging</span> of black carbon containing particles in an idealized urban plume using a new approach, the particleresolved aerosol <span class="hlt">model</span> PartMC-MOSAIC. We present a method to estimate <span class="hlt">aging</span> time-scales using an <span class="hlt">aging</span> criterion based on cloud condensation nuclei activation. The results show a separation into a daytime regime where condensation dominates and a nighttime regime where coagulation dominates. For the chosen urban plume scenario, depending on the supersaturation threshold, the values for the <span class="hlt">aging</span> timescales vary between 0.06 hours and 10 hours during the day, and between 6 hours and 20 hours during the night.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20719395','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20719395"><span id="translatedtitle">Behavior problems at <span class="hlt">ages</span> 6 and 11 and high school academic achievement: longitudinal latent variable <span class="hlt">modeling</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Breslau, Naomi; Breslau, Joshua; Miller, Elizabeth; Raykov, Tenko</p> <p>2011-02-28</p> <p>Previous studies documented long-run effects of behavior problems at the start of school on academic achievement. However, these studies did not examine whether the observed effects of early behavior problems are explained by more proximate behavior problems, given the tendency of children's behavior problems to persist. Latent variable <span class="hlt">modeling</span> was applied to estimate the effects of behavior problems at <span class="hlt">ages</span> 6 and 11 on academic achievement at <span class="hlt">age</span> 17, using data from a longitudinal study (n=823). Behavior problems at <span class="hlt">ages</span> 6 and 11, each stage independently of the other, predicted lower math and reading test scores at <span class="hlt">age</span> 17, controlling for intelligence quotient (IQ), birth weight, maternal characteristics, family and community environment, and taking into account behavior problems at <span class="hlt">age</span> 17. Behavior problems at the start of school, independent of later behavior problems, exert lingering effects on achievement by impeding the acquisition of cognitive skills that are the foundation for later academic progress. PMID:20719395</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26459146','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26459146"><span id="translatedtitle">Lens opacity based <span class="hlt">modelling</span> of the <span class="hlt">age</span>-related straylight increase.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rozema, Jos J; Sanchez, Victoria; Artal, Natalia; Gramajo, Ana L; Torres, Eduardo; Luna, Jose D; Iribarren, Rafael; Tassignon, Marie-José; Juarez, Claudio P</p> <p>2015-12-01</p> <p>This work studies ethnic and geographical differences in the <span class="hlt">age</span>-related straylight increase by means of a stochastic <span class="hlt">model</span> and unpublished lens opacity data of 559 residents of Villa Maria (Argentina), as well as data of 912 Indonesian subjects published previously by Husain et al. For both cohorts the prevalence of each type and grade of lens opacity was determined as a function of <span class="hlt">age</span>, from which a stochastic <span class="hlt">model</span> was derived capable of simulating the lens opacity prevalence for both populations. These simulated lens opacity data were then converted to estimated straylight by means of an equation derived from previously recorded data of 107 eyes with varying degrees of cataract. Based on these opacity templates 2500 random sets of subject <span class="hlt">age</span> and lens opacity data were generated by the stochastic <span class="hlt">model</span> for each dataset, from which estimated straylight could be calculated. For the Argentinian data the estimated straylight was found to closely resemble the published <span class="hlt">models</span> for <span class="hlt">age</span>-related straylight increase. For younger eyes the straylight variation of the <span class="hlt">model</span> was the same as what was previously published (in both cases ±0.200logunits), which doubled in size for older eyes. For the Indonesian data, however, this <span class="hlt">age</span>-related straylight increase was found to be fundamentally different from the published <span class="hlt">age</span> <span class="hlt">model</span>. This suggests that current normative curves for <span class="hlt">age</span>-related straylight increase may not always be appropriate for non-European populations, and that the inter-individual straylight variations in young, healthy eyes may possibly be due to variations in lens opacities. PMID:26459146</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPS...324..694L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPS...324..694L"><span id="translatedtitle">Lithium-ion Open Circuit Voltage (OCV) curve <span class="hlt">modelling</span> and its <span class="hlt">ageing</span> adjustment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavigne, L.; Sabatier, J.; Francisco, J. Mbala; Guillemard, F.; Noury, A.</p> <p>2016-08-01</p> <p>This paper is a contribution to lithium-ion batteries <span class="hlt">modelling</span> taking into account <span class="hlt">aging</span> effects. It first analyses the impact of <span class="hlt">aging</span> on electrode stoichiometry and then on lithium-ion cell Open Circuit Voltage (OCV) curve. Through some hypotheses and an appropriate definition of the cell state of charge, it shows that each electrode equilibrium potential, but also the whole cell equilibrium potential can be <span class="hlt">modelled</span> by a polynomial that requires only one adjustment parameter during <span class="hlt">aging</span>. An adjustment algorithm, based on the idea that for two fixed OCVs, the state of charge between these two equilibrium states is unique for a given <span class="hlt">aging</span> level, is then proposed. Its efficiency is evaluated on a battery pack constituted of four cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhDT........73K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhDT........73K"><span id="translatedtitle">Assignment of <span class="hlt">absolute</span> stereochemistry by computation of optical rotation angles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kondru, Rama Krishna</p> <p></p> <p>We have developed simple wire and molecular orbital <span class="hlt">models</span> to qualitatively and quantitatively understand optical rotation angles of molecules. We reported the first ab initio theoretical approach to determine the <span class="hlt">absolute</span> stereochemistry of a complex natural product by calculating molar rotation angles, [M]D. We applied this method for an unambiguous assignment of the <span class="hlt">absolute</span> stereochemistry of the hennoxazole A. A protocol analogous to population analysis was devised to analyze atomic contributions to the rotation angles for oxiranes, orthoesters, and other organic compounds. The molar rotations for an indoline, an indonone, menthol and menthone were calculated using ab inito methods and compared with experimental values. We reported the first prediction of the <span class="hlt">absolute</span> configuration of a natural product, i.e. an a priori assignment of the relative and <span class="hlt">absolute</span> stereochemistry of pitiamide A. Furthermore, we described a strategy that may help to establish structure-function relations for rotation angles by visualizing the electric and magnetic-field perturbations to a molecule's molecular orbitals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4150363','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4150363"><span id="translatedtitle">The effects of <span class="hlt">aging</span> on the BTBR mouse <span class="hlt">model</span> of autism spectrum disorder</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jasien, Joan M.; Daimon, Caitlin M.; Wang, Rui; Shapiro, Bruce K.; Martin, Bronwen; Maudsley, Stuart</p> <p>2014-01-01</p> <p>Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder characterized by alterations in social functioning, communicative abilities, and engagement in repetitive or restrictive behaviors. The process of <span class="hlt">aging</span> in individuals with autism and related neurodevelopmental disorders is not well understood, despite the fact that the number of individuals with ASD <span class="hlt">aged</span> 65 and older is projected to increase by over half a million individuals in the next 20 years. To elucidate the effects of <span class="hlt">aging</span> in the context of a modified central nervous system, we investigated the effects of <span class="hlt">age</span> on the BTBR T + tf/j mouse, a well characterized and widely used mouse <span class="hlt">model</span> that displays an ASD-like phenotype. We found that a reduction in social behavior persists into old <span class="hlt">age</span> in male BTBR T + tf/j mice. We employed quantitative proteomics to discover potential alterations in signaling systems that could regulate <span class="hlt">aging</span> in the BTBR mice. Unbiased proteomic analysis of hippocampal and cortical tissue of BTBR mice compared to <span class="hlt">age</span>-matched wild-type controls revealed a significant decrease in brain derived neurotrophic factor and significant increases in multiple synaptic markers (spinophilin, Synapsin I, PSD 95, NeuN), as well as distinct changes in functional pathways related to these proteins, including “Neural synaptic plasticity regulation” and “Neurotransmitter secretion regulation.” Taken together, these results contribute to our understanding of the effects of <span class="hlt">aging</span> on an ASD-like mouse <span class="hlt">model</span> in regards to both behavior and protein alterations, though additional studies are needed to fully understand the complex interplay underlying <span class="hlt">aging</span> in mouse <span class="hlt">models</span> displaying an ASD-like phenotype. PMID:25225482</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3392540','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3392540"><span id="translatedtitle">The Quadratic Hazard <span class="hlt">Model</span> for Analyzing Longitudinal Data on <span class="hlt">Aging</span>, Health, and the Life Span</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yashin, A.I.; Arbeev, K.G.; Akushevich, I.; Kulminski, A.; Ukraintseva, S.V.; Stallard, E.; Land, K.C.</p> <p>2012-01-01</p> <p>A better understanding of processes and mechanisms linking human <span class="hlt">aging</span> with changes in health status and survival requires methods capable of analyzing new data that take into account knowledge about these processes accumulated in the field. In this paper, we describe an approach to analyses of longitudinal data based on the use of stochastic process <span class="hlt">models</span> of human <span class="hlt">aging</span>, health, and longevity which allows for incorporating state of the art advances in <span class="hlt">aging</span> research into the <span class="hlt">model</span> structure. In particular, the <span class="hlt">model</span> incorporates the notions of resistance to stresses, adaptive capacity, and “optimal” (normal) physiological states. To capture the effects of exposure to persistent external disturbances, the notions of allostatic adaptation and allostatic load are introduced. These notions facilitate the description and explanation of deviations of individuals’ physiological indices from their normal states, which increase the chances of disease development and death. The <span class="hlt">model</span> provides a convenient conceptual framework for comprehensive systemic analyses of <span class="hlt">aging</span>-related changes in humans using longitudinal data and linking these changes with genotyping profiles, morbidity, and mortality risks. The <span class="hlt">model</span> is used for developing new statistical methods for analyzing longitudinal data on <span class="hlt">aging</span>, health, and longevity. PMID:22633776</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9609813','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9609813"><span id="translatedtitle">Predictors of <span class="hlt">age</span>-associated decline in maximal aerobic capacity: a comparison of four statistical <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rosen, M J; Sorkin, J D; Goldberg, A P; Hagberg, J M; Katzel, L I</p> <p>1998-06-01</p> <p>Studies assessing changes in maximal aerobic capacity (VO2 max) associated with <span class="hlt">aging</span> have traditionally employed the ratio of VO2 max to body weight. Log-linear, ordinary least-squares, and weighted least-squares <span class="hlt">models</span> may avoid some of the inherent weaknesses associated with the use of ratios. In this study we used four different methods to examine the <span class="hlt">age</span>-associated decline in VO2 max in a cross-sectional sample of 276 healthy men, <span class="hlt">aged</span> 45-80 yr. Sixty-one of the men were aerobically trained athletes, and the remainder were sedentary. The <span class="hlt">model</span> that accounted for the largest proportion of variance was a weighted least-squares <span class="hlt">model</span> that included <span class="hlt">age</span>, fat-free mass, and an indicator variable denoting exercise training status. The <span class="hlt">model</span> accounted for 66% of the variance in VO2 max and satisfied all the important general linear <span class="hlt">model</span> assumptions. The other approaches failed to satisfy one or more of these assumptions. The results indicated that VO2 max declines at the same rate in athletic and sedentary men (0.24 l/min or 9%/decade) and that 35% of this decline (0.08 l . min-1 . decade-1) is due to the <span class="hlt">age</span>-associated loss of fat-free mass. PMID:9609813</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996AIPC..361..381V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996AIPC..361..381V&link_type=ABSTRACT"><span id="translatedtitle">Government, industry, and university partnerships: A <span class="hlt">model</span> for the knowledge <span class="hlt">age</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varner, Michael O.</p> <p>1996-03-01</p> <p>New technologies are transforming the industrial economy into a marketplace driven by information and knowledge. The depth, breadth, and rate of technology development, however, overwhelms our ability to absorb, process, and recall new information. Moreover, the bright future enabled by the knowledge <span class="hlt">age</span> cannot be realized without the development of new organizational <span class="hlt">models</span> and philosophies. This paper discusses the necessity for business, government, and universities to create inter-institutional partnerships in order to accommodate change and flourish in the knowledge <span class="hlt">age</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4806321','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4806321"><span id="translatedtitle"><span class="hlt">Age</span>-Dependent Metastatic Spread and Survival: Cancer of Unknown Primary as a <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hemminki, Kari; Pavlidis, Nicholas; Tsilidis, Konstantinos K.; Sundquist, Kristina; Ji, Jianguang</p> <p>2016-01-01</p> <p>In order to describe a novel approach for the clinical study of metastases, we provide here <span class="hlt">age</span>-specific incidence and survival data for cancer of unknown primary (CUP). Metastases in various organs are found at CUP diagnosis, which have implications for prognosis, and we hypothesize similar prognostic implications for metastases found at diagnosis of primary cancers. We identified 33,224 CUP patients from the Swedish Cancer Registry and calculated incidence rates (IRs) for CUP development. Cox proportional hazards regression <span class="hlt">models</span> were performed to estimate hazard ratios (HRs) for relative survival in CUP patients compared to the general population. In <span class="hlt">age</span>-group specific analyses, a maximal IR was reached at <span class="hlt">age</span> 85–89 years, followed by a marked decline to <span class="hlt">age</span> 90+ (7-fold in men and 3-fold in women). The overall HR for relative survival declined systematically by <span class="hlt">age</span>. CUP may be applied as an epidemiological <span class="hlt">age</span>-incidence <span class="hlt">model</span> for cancer metastases providing evidence in line with autopsy data that the metastatic potential, as shown by the incidence of CUP, appears to weaken markedly at <span class="hlt">age</span> 85 years, depending on metastatic locations. The relative death rates were highest among young patients, which was probably entirely due to the low death rates in young background population. PMID:27009354</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhRvE..72c1911S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhRvE..72c1911S"><span id="translatedtitle">Simulations of a mortality plateau in the sexual Penna <span class="hlt">model</span> for biological <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwämmle, V.; de Oliveira, S. Moss</p> <p>2005-09-01</p> <p>The Penna <span class="hlt">model</span> is a strategy to simulate the genetic dynamics of <span class="hlt">age</span>-structured populations, in which the individual genomes are represented by bit strings. It provides a simple metaphor for the evolutionary process in terms of the mutation accumulation theory. In its original version, an individual dies due to inherited diseases when its current number of accumulated mutations, n , reaches a threshold value T . Since the mean number of diseases increases with <span class="hlt">age</span>, the probability to die is zero for very young <span class="hlt">ages</span> (n<T) and equals 1 for the old ones (n⩾T) . Here, instead of using a step function to determine the genetic death <span class="hlt">age</span>, we test several other functions that may or may not slightly increase the death probability at young <span class="hlt">ages</span> (n<T) , but that decrease this probability at old ones. Our purpose is to study the oldest old effect, that is, a plateau in the mortality curves at advanced <span class="hlt">ages</span>. By imposing certain conditions, it has been possible to obtain a clear plateau using the Penna <span class="hlt">model</span>. However, a more realistic one appears when a modified version, that keeps the population size fixed without fluctuations, is used. We also find a relation between the birth rate, the <span class="hlt">age</span> structure of the population, and the death probability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27051508','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27051508"><span id="translatedtitle">Understanding the physiology of the <span class="hlt">ageing</span> individual: computational <span class="hlt">modelling</span> of changes in metabolism and endurance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Beek, Johannes H G M; Kirkwood, Thomas B L; Bassingthwaighte, James B</p> <p>2016-04-01</p> <p><span class="hlt">Ageing</span> and lifespan are strongly affected by metabolism. The maximal possible uptake of oxygen is not only a good predictor of performance in endurance sports, but also of life expectancy. Figuratively speaking, healthy <span class="hlt">ageing</span> is a competitive sport. Although the root cause of <span class="hlt">ageing</span> is damage to macromolecules, it is the balance with repair processes that is decisive. Reduced or intermittent nutrition, hormones and intracellular signalling pathways that regulate metabolism have strong effects on <span class="hlt">ageing</span>. Homeostatic regulatory processes tend to keep the environment of the cells within relatively narrow bounds. On the other hand, the body is constantly adapting to physical activity and food consumption. Spontaneous fluctuations in heart rate and other processes indicate youth and health. A (homeo)dynamic aspect of homeostasis deteriorates with <span class="hlt">age</span>. We are now in a position to develop computational <span class="hlt">models</span> of human metabolism and the dynamics of heart rhythm and oxygen transport that will advance our understanding of <span class="hlt">ageing</span>. Computational <span class="hlt">modelling</span> of the connections between dietary restriction, metabolism and protein turnover may increase insight into homeostasis of the proteins in our body. In this way, the computational reconstruction of human physiological processes, the Physiome, can help prevent frailty and <span class="hlt">age</span>-related disease. PMID:27051508</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4943626','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4943626"><span id="translatedtitle">Voluntary Medical Male Circumcision for HIV Prevention in Swaziland: <span class="hlt">Modeling</span> the Impact of <span class="hlt">Age</span> Targeting</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kripke, Katharine; Okello, Velephi; Maziya, Vusi; Benzerga, Wendy; Mirira, Munamato; Gold, Elizabeth; Schnure, Melissa; Sgaier, Sema; Castor, Delivette; Reed, Jason</p> <p>2016-01-01</p> <p>Background Voluntary medical male circumcision (VMMC) for HIV prevention has been a priority for Swaziland since 2009. Initially focusing on men <span class="hlt">ages</span> 15–49, the Ministry of Health reduced the minimum <span class="hlt">age</span> for VMMC from 15 to 10 years in 2012, given the existing demand among 10- to 15-year-olds. To understand the implications of focusing VMMC service delivery on specific <span class="hlt">age</span> groups, the MOH undertook a <span class="hlt">modeling</span> exercise to inform policy and implementation in 2013–2014. Methods and Findings The impact and cost of circumcising specific <span class="hlt">age</span> groups were assessed using the Decision Makers’ Program Planning Tool, Version 2.0 (DMPPT 2.0), a simple compartmental <span class="hlt">model</span>. We used <span class="hlt">age</span>-specific HIV incidence from the Swaziland HIV Incidence Measurement Survey (SHIMS). Population, mortality, births, and HIV prevalence were imported from a national Spectrum/Goals <span class="hlt">model</span> recently updated in consultation with country stakeholders. Baseline male circumcision prevalence was derived from the most recent Swaziland Demographic and Health Survey. The lowest numbers of VMMCs per HIV infection averted are achieved when males <span class="hlt">ages</span> 15–19, 20–24, 25–29, and 30–34 are circumcised, although the uncertainty bounds for the estimates overlap. Circumcising males <span class="hlt">ages</span> 25–29 and 20–24 provides the most immediate reduction in HIV incidence. Circumcising males <span class="hlt">ages</span> 15–19, 20–24, and 25–29 provides the greatest magnitude incidence reduction within 15 years. The lowest cost per HIV infection averted is achieved by circumcising males <span class="hlt">ages</span> 15–34: $870 U.S. dollars (USD). Conclusions The potential impact, cost, and cost-effectiveness of VMMC scale-up in Swaziland are not uniform. They vary by the <span class="hlt">age</span> group of males circumcised. Based on the results of this <span class="hlt">modeling</span> exercise, the Ministry of Health’s Swaziland Male Circumcision Strategic and Operational Plan 2014–2018 adopted an implementation strategy that calls for circumcision to be scaled up to 50% coverage for neonates, 80</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3466803','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3466803"><span id="translatedtitle">Trajectories of Sleep Complaints From Early Midlife to Old <span class="hlt">Age</span>: Longitudinal <span class="hlt">Modeling</span> Study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Salo, Paula; Vahtera, Jussi; Ferrie, Jane E.; Akbaraly, Tasnime; Goldberg, Marcel; Zins, Marie; Pentti, Jaana; Virtanen, Marianna; Shipley, Martin J.; Singh-Manoux, Archana; Dauvilliers, Yves; Kivimaki, Mika</p> <p>2012-01-01</p> <p>Study Objectives: To estimate trajectories of sleep lost over worry as a function of <span class="hlt">age</span>, using longitudinal <span class="hlt">modeling</span>, and compare these trajectories with those for insomnia symptoms. Design and Setting: Data from two prospective, occupational cohorts (the Whitehall II and Finnish Public Sector studies) comprising 84,384 observations from four to eight repeat measurements in 1985-2010. Participants: There were 16,408 men and women <span class="hlt">age</span> 34-79 yr. Measurements and Results: <span class="hlt">Age</span>-related trajectories of sleep lost over worry and insomnia symptoms (sleep initiation or maintenance problems, nonrefreshing sleep) were estimated using repeated-measures log-binomial regression analysis and generalized estimating equations. These analyses were adjusted for year of birth and time of measurement to minimize confounding by cohort or period effects. The prevalence ratio for insomnia symptoms was higher in older <span class="hlt">age</span> groups compared with participants <span class="hlt">age</span> 34-45 yr. In contrast, the <span class="hlt">age</span>-related trajectory of sleep lost over worry included two phases: a period of high prevalence of sleep complaints at <span class="hlt">age</span> 34-60 yr followed by a declining trajectory at older <span class="hlt">ages</span>. Compared with participants <span class="hlt">age</span> 34-45 yr, prevalence ratios for sleep lost over worry were 0.63 (0.49-0.80) and 0.59 (0.41-0.84) in the Whitehall II study participants <span class="hlt">ages</span> 61-65 and 71-79 years. Corresponding figures were 0.62 (0.52-0.75) and 0.46 (0.32-0.66) in the Finnish Public Sector study. Conclusion: This study shows a general <span class="hlt">age</span>-related decrease in sleep lost over worry between late midlife and old <span class="hlt">age</span>, a pattern strikingly different from the <span class="hlt">age</span>-related increase in insomnia symptoms. Citation: Salo P; Vahtera J; Ferrie JE; Akbaraly T; Goldberg M; Zins M; Pentti J; Virtanen M; Shipley MJ; Singh-Manoux A; Dauvilliers Y; Kivimaki M. Trajectories of sleep complaints from early midlife to old <span class="hlt">age</span>: longitudinal <span class="hlt">modeling</span> study. SLEEP 2012;35(11):1559-1568. PMID:23115405</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AIPC..978...98A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AIPC..978...98A&link_type=ABSTRACT"><span id="translatedtitle">Evaluation of <span class="hlt">Aged</span> Garlic Extract Neuroprotective Effect in a Focal <span class="hlt">Model</span> of Cerebral Ischemia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aguilera, Penélope; Maldonado, Perla D.; Ortiz-Plata, Alma; Barrera, Diana; Chánez-Cárdenas, María Elena</p> <p>2008-02-01</p> <p>The oxidant species generated in cerebral ischemia have been implicated as important mediators of neuronal injury through damage to lipids, DNA, and proteins. Since ischemia as well as reperfusion insults generate oxidative stress, the administration of antioxidants may limit oxidative damage and ameliorate disease progression. The present work shows the transitory neuroprotective effect of the <span class="hlt">aged</span> garlic extract (<span class="hlt">AGE</span>) administration (a proposed antioxidant compound) in a middle cerebral artery occlusion (MCAO) <span class="hlt">model</span> in rats and established its therapeutic window. To determine the optimal time of administration, animal received <span class="hlt">AGE</span> (1.2 mL/kg) intraperitoneally 30 min before onset of reperfusion (-0.5 R), at the beginning of reperfusion (0R), or 1 h after onset of reperfusion (1R). Additional doses were administrated after 1, 2, or 3 h after onset of reperfusion. To establish the therapeutic window of <span class="hlt">AGE</span>, the infarct area was determined for each treatment after different times of reperfusion. Results show that the administration of <span class="hlt">AGE</span> at the onset of reperfusion reduced the infarct area by 70% (evaluated after 2 h reperfusion). The therapeutic window of <span class="hlt">AGE</span> was determined. Repeated doses did not extend the temporal window of protection. A significant reduction in the nitrotyrosine level was observed in the brain tissue subjected to MCAO after <span class="hlt">AGE</span> treatment at the onset of reperfusion. Data in the present work show that <span class="hlt">AGE</span> exerts a transitory neuroprotective effect in response to ischemia/reperfusion-induced neuronal injury.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26642856','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26642856"><span id="translatedtitle">The African Turquoise Killifish: A <span class="hlt">Model</span> for Exploring Vertebrate <span class="hlt">Aging</span> and Diseases in the Fast Lane.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Harel, Itamar; Brunet, Anne</p> <p>2015-01-01</p> <p>Why and how organisms <span class="hlt">age</span> remains a mystery, and it defines one of the biggest challenges in biology. <span class="hlt">Aging</span> is also the primary risk factor for many human pathologies, such as cancer, diabetes, cardiovascular diseases, and neurodegenerative diseases. Thus, manipulating the <span class="hlt">aging</span> rate and potentially postponing the onset of these devastating diseases could have a tremendous impact on human health. Recent studies, relying primarily on nonvertebrate short-lived <span class="hlt">model</span> systems, have shown the importance of both genetic and environmental factors in modulating the <span class="hlt">aging</span> rate. However, relatively little is known about <span class="hlt">aging</span> in vertebrates or what processes may be unique and specific to these complex organisms. Here we discuss how advances in genomics and genome editing have significantly expanded our ability to probe the <span class="hlt">aging</span> process in a vertebrate system. We highlight recent findings from a naturally short-lived vertebrate, the African turquoise killifish, which provides an attractive platform for exploring mechanisms underlying vertebrate <span class="hlt">aging</span> and <span class="hlt">age</span>-related diseases. PMID:26642856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3634046','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3634046"><span id="translatedtitle">Accounting for <span class="hlt">Age</span> Uncertainty in Growth <span class="hlt">Modeling</span>, the Case Study of Yellowfin Tuna (Thunnus albacares) of the Indian Ocean</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dortel, Emmanuelle; Massiot-Granier, Félix; Rivot, Etienne; Million, Julien; Hallier, Jean-Pierre; Morize, Eric; Munaron, Jean-Marie; Bousquet, Nicolas; Chassot, Emmanuel</p> <p>2013-01-01</p> <p><span class="hlt">Age</span> estimates, typically determined by counting periodic growth increments in calcified structures of vertebrates, are the basis of population dynamics <span class="hlt">models</span> used for managing exploited or threatened species. In fisheries research, the use of otolith growth rings as an indicator of fish <span class="hlt">age</span> has increased considerably in recent decades. However, otolith readings include various sources of uncertainty. Current <span class="hlt">ageing</span> methods, which converts an average count of rings into <span class="hlt">age</span>, only provide periodic <span class="hlt">age</span> estimates in which the range of uncertainty is fully ignored. In this study, we describe a hierarchical <span class="hlt">model</span> for estimating individual <span class="hlt">ages</span> from repeated otolith readings. The <span class="hlt">model</span> was developed within a Bayesian framework to explicitly represent the sources of uncertainty associated with <span class="hlt">age</span> estimation, to allow for individual variations and to include knowledge on parameters from expertise. The performance of the proposed <span class="hlt">model</span> was examined through simulations, and then it was coupled to a two-stanza somatic growth <span class="hlt">model</span> to evaluate the impact of the <span class="hlt">age</span> estimation method on the <span class="hlt">age</span> composition of commercial fisheries catches. We illustrate our approach using the saggital otoliths of yellowfin tuna of the Indian Ocean collected through large-scale mark-recapture experiments. The simulation performance suggested that the <span class="hlt">ageing</span> error <span class="hlt">model</span> was able to estimate the <span class="hlt">ageing</span> biases and provide accurate <span class="hlt">age</span> estimates, regardless of the <span class="hlt">age</span> of the fish. Coupled with the growth <span class="hlt">model</span>, this approach appeared suitable for <span class="hlt">modeling</span> the growth of Indian Ocean yellowfin and is consistent with findings of previous studies. The simulations showed that the choice of the <span class="hlt">ageing</span> method can strongly affect growth estimates with subsequent implications for <span class="hlt">age</span>-structured data used as inputs for population <span class="hlt">models</span>. Finally, our <span class="hlt">modeling</span> approach revealed particularly useful to reflect uncertainty around <span class="hlt">age</span> estimates into the process of growth estimation and it can be applied to any</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23637773','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23637773"><span id="translatedtitle">Accounting for <span class="hlt">age</span> uncertainty in growth <span class="hlt">modeling</span>, the case study of yellowfin tuna (Thunnus albacares) of the Indian Ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dortel, Emmanuelle; Massiot-Granier, Félix; Rivot, Etienne; Million, Julien; Hallier, Jean-Pierre; Morize, Eric; Munaron, Jean-Marie; Bousquet, Nicolas; Chassot, Emmanuel</p> <p>2013-01-01</p> <p><span class="hlt">Age</span> estimates, typically determined by counting periodic growth increments in calcified structures of vertebrates, are the basis of population dynamics <span class="hlt">models</span> used for managing exploited or threatened species. In fisheries research, the use of otolith growth rings as an indicator of fish <span class="hlt">age</span> has increased considerably in recent decades. However, otolith readings include various sources of uncertainty. Current <span class="hlt">ageing</span> methods, which converts an average count of rings into <span class="hlt">age</span>, only provide periodic <span class="hlt">age</span> estimates in which the range of uncertainty is fully ignored. In this study, we describe a hierarchical <span class="hlt">model</span> for estimating individual <span class="hlt">ages</span> from repeated otolith readings. The <span class="hlt">model</span> was developed within a Bayesian framework to explicitly represent the sources of uncertainty associated with <span class="hlt">age</span> estimation, to allow for individual variations and to include knowledge on parameters from expertise. The performance of the proposed <span class="hlt">model</span> was examined through simulations, and then it was coupled to a two-stanza somatic growth <span class="hlt">model</span> to evaluate the impact of the <span class="hlt">age</span> estimation method on the <span class="hlt">age</span> composition of commercial fisheries catches. We illustrate our approach using the sagittal otoliths of yellowfin tuna of the Indian Ocean collected through large-scale mark-recapture experiments. The simulation performance suggested that the <span class="hlt">ageing</span> error <span class="hlt">model</span> was able to estimate the <span class="hlt">ageing</span> biases and provide accurate <span class="hlt">age</span> estimates, regardless of the <span class="hlt">age</span> of the fish. Coupled with the growth <span class="hlt">model</span>, this approach appeared suitable for <span class="hlt">modeling</span> the growth of Indian Ocean yellowfin and is consistent with findings of previous studies. The simulations showed that the choice of the <span class="hlt">ageing</span> method can strongly affect growth estimates with subsequent implications for <span class="hlt">age</span>-structured data used as inputs for population <span class="hlt">models</span>. Finally, our <span class="hlt">modeling</span> approach revealed particularly useful to reflect uncertainty around <span class="hlt">age</span> estimates into the process of growth estimation and it can be applied to any</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H53F1480E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H53F1480E"><span id="translatedtitle"><span class="hlt">Modeling</span> transient groundwater <span class="hlt">age</span> in the Middle Wairarapa Valley, New Zealand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evison, R.; Daughney, C.; Jackson, B. M.; Toews, M. W.; Cornaton, F. J.; Gyopari, M.; McAllister, D.</p> <p>2013-12-01</p> <p><span class="hlt">Age</span> information provides insights into groundwater flow and transport processes and thus enables better groundwater management. It is accepted that groundwater is composed of a mixture of water with different <span class="hlt">ages</span>. For example, a groundwater sample with an old mean <span class="hlt">age</span> may still contain a fraction of young water; recent contamination is therefore a potential risk that may not be conveyed by consideration of the mean <span class="hlt">age</span> alone. This project focuses on catchment-scale evaluation of the full distribution of groundwater <span class="hlt">age</span> as a function of space and time in the 270 km2 Middle Wairarapa Valley, New Zealand. The Wairarapa Valley exhibits complex interactions between its rivers and shallow aquifers. Agriculture is an integral part of the region with widespread irrigation and nutrient application. This requires effective regional management due to the risk of contamination and depletion of groundwater reservoirs. The starting point was a transient finite-element groundwater flow <span class="hlt">model</span> originally developed by Greater Wellington Regional Council (GWRC). The GWRC flow <span class="hlt">model</span> was converted to simulate transport of the <span class="hlt">age</span> tracer tritium using Ground Water (GW) software. There are several techniques to calibrate groundwater <span class="hlt">models</span> and assess appropriate parameter values, all of which have the problem of non-uniqueness. In this study the Gauss-Marquardt-Levenberg method was utilized to calibrate the <span class="hlt">model</span> (through PEST), but in order to increase robustness, a classic Monte Carlo method with uniform random sampling was also used to sample the domain's global range of flow and transport parameters. This provided an increased measure of confidence in <span class="hlt">model</span> output, as the global range of parameter values could be explored, which is not achieved via the localized Gauss-Marquardt-Levenberg parameter estimation scheme. The calibration objective with both methods used least squares minimization between the simulated and observed hydraulic head levels and tritium concentrations. GW</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19831037','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19831037"><span id="translatedtitle">Jasminum flexile flower <span class="hlt">absolute</span> from India--a detailed comparison with three other jasmine <span class="hlt">absolutes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Braun, Norbert A; Kohlenberg, Birgit; Sim, Sherina; Meier, Manfred; Hammerschmidt, Franz-Josef</p> <p>2009-09-01</p> <p>Jasminum flexile flower <span class="hlt">absolute</span> from the south of India and the corresponding vacuum headspace (VHS) sample of the <span class="hlt">absolute</span> were analyzed using GC and GC-MS. Three other commercially available Indian jasmine <span class="hlt">absolutes</span> from the species: J. sambac, J. officinale subsp. grandiflorum, and J. auriculatum and the respective VHS samples were used for comparison purposes. One hundred and twenty-one compounds were characterized in J. flexile flower <span class="hlt">absolute</span>, with methyl linolate, benzyl salicylate, benzyl benzoate, (2E,6E)-farnesol, and benzyl acetate as the main constituents. A detailed olfactory evaluation was also performed. PMID:19831037</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014CNSNS..19.2466Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014CNSNS..19.2466Z&link_type=ABSTRACT"><span id="translatedtitle">Dynamic analysis of a hepatitis B <span class="hlt">model</span> with three-<span class="hlt">age</span>-classes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Suxia; Zhou, Yicang</p> <p>2014-07-01</p> <p>Based on the fact that the likelihood of becoming chronically infected is dependent on <span class="hlt">age</span> at primary infection Kane (1995) [2], Edmunds et al. (1993) [3], Medley et al. (2001) [4], and Ganem and Prince (2004) [6], we formulate a hepatitis B transmission <span class="hlt">model</span> with three <span class="hlt">age</span> classes. The reproduction number, R0 is defined and the dynamical behavior of the <span class="hlt">model</span> is analyzed. It is proved that the disease-free equilibrium is globally stable if R0<1, and there exists at least one endemic equilibrium and that the disease is uniformly persistent if R0>1. The unique endemic equilibrium and its global stability is obtained in a special case. Simulations are also conducted to compare the dynamical behavior of the <span class="hlt">model</span> with and without <span class="hlt">age</span> classes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15533791','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15533791"><span id="translatedtitle">The use of mature zebrafish (Danio rerio) as a <span class="hlt">model</span> for human <span class="hlt">aging</span> and disease.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Keller, Evan T; Murtha, Jill M</p> <p>2004-07-01</p> <p>Zebrafish (Danio rerio) have been extensively utilized for understanding mechanisms of development. These studies have led to a wealth of resources including genetic tools, informational databases, and husbandry methods. In spite of all these resources, zebrafish have been underutilized for exploring pathophysiology of disease and the <span class="hlt">aging</span> process. Zebrafish offer several advantages over mammalian <span class="hlt">models</span> for these studies, including the ability to perform saturation mutagenesis and the capability to contain thousands of animals in a small space. In this review, we will discuss the use of mature zebrafish as an animal <span class="hlt">model</span> and provide specific examples to support this novel use of zebrafish. Examples include demonstrating that clinical pathology can be performed in mature zebrafish and that <span class="hlt">age</span>-associated changes in heat shock response can be observed in zebrafish. These highlights demonstrate the utility of zebrafish as a <span class="hlt">model</span> for disease and <span class="hlt">aging</span>. PMID:15533791</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25295520','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25295520"><span id="translatedtitle">A validated <span class="hlt">age</span>-related normative <span class="hlt">model</span> for male total testosterone shows increasing variance but no decline after <span class="hlt">age</span> 40 years.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kelsey, Thomas W; Li, Lucy Q; Mitchell, Rod T; Whelan, Ashley; Anderson, Richard A; Wallace, W Hamish B</p> <p>2014-01-01</p> <p>The diagnosis of hypogonadism in human males includes identification of low serum testosterone levels, and hence there is an underlying assumption that normal ranges of testosterone for the healthy population are known for all <span class="hlt">ages</span>. However, to our knowledge, no such reference <span class="hlt">model</span> exists in the literature, and hence the availability of an applicable biochemical reference range would be helpful for the clinical assessment of hypogonadal men. In this study, using <span class="hlt">model</span> selection and validation analysis of data identified and extracted from thirteen studies, we derive and validate a normative <span class="hlt">model</span> of total testosterone across the lifespan in healthy men. We show that total testosterone peaks [mean (2.5-97.5 percentile)] at 15.4 (7.2-31.1) nmol/L at an average <span class="hlt">age</span> of 19 years, and falls in the average case [mean (2.5-97.5 percentile)] to 13.0 (6.6-25.3) nmol/L by <span class="hlt">age</span> 40 years, but we find no evidence for a further fall in mean total testosterone with increasing <span class="hlt">age</span> through to old <span class="hlt">age</span>. However we do show that there is an increased variation in total testosterone levels with advancing <span class="hlt">age</span> after <span class="hlt">age</span> 40 years. This <span class="hlt">model</span> provides the <span class="hlt">age</span> related reference ranges needed to support research and clinical decision making in males who have symptoms that may be due to hypogonadism. PMID:25295520</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.7593P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.7593P"><span id="translatedtitle">Validation of GOCE by <span class="hlt">absolute</span> and relative gravimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pettersen, B. R.; Sprlak, M.; Lysaker, D. I.; Omang, O. C. D.; Sekowski, M.; Dykowski, P.</p> <p>2012-04-01</p> <p><span class="hlt">Absolute</span> gravimetry has been performed in 2011 by FG5 and A10 instruments in selected sites of the Norwegian first order gravity network. These observations are used as reference values to transform a large number of relative gravity values collected in 1968-1972. The outcome is a database at current epoch in a reference frame defined by the <span class="hlt">absolute</span> gravity values. This constitutes our test field for validation of GOCE results. In the test fields, validation of GOCE-derived gravity anomalies was performed. The spectral enhancement method was applied to avoid the spectral inconsistency between the terrestrial and the satellite data. For this purpose, contributions of the EGM2008 <span class="hlt">model</span> and a gravitational effect of a residual terrain <span class="hlt">model</span> were calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10665203','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10665203"><span id="translatedtitle"><span class="hlt">Modeling</span> computer interest in older adults: the role of <span class="hlt">age</span>, education, computer knowledge, and computer anxiety.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ellis, D; Allaire, J C</p> <p>1999-09-01</p> <p>We proposed a mediation <span class="hlt">model</span> to examine the effects of <span class="hlt">age</span>, education, computer knowledge, and computer anxiety on computer interest in older adults. We hypothesized that computer knowledge and computer anxiety would fully mediate the effects of <span class="hlt">age</span> and education on computer interest. A sample of 330 older adults from local senior-citizen apartment buildings completed a survey that included an assessment of the constructs included in the <span class="hlt">model</span>. Using structural equation <span class="hlt">modeling</span>, we found that the results supported the hypothesized mediation <span class="hlt">model</span>. In particular, the effect of computer knowledge operated on computer interest through computer anxiety. The effect of <span class="hlt">age</span> was not fully mitigated by the other <span class="hlt">model</span> variables, indicating the need for future research that identifies and <span class="hlt">models</span> other correlates of <span class="hlt">age</span> and computer interest. The most immediate application of this research is the finding that a simple 3-item instrument can be used to assess computer interest in older populations. This will help professionals plan and implement computer services in public-access settings for older adults. An additional application of this research is the information it provides for training program designers. PMID:10665203</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4631373','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4631373"><span id="translatedtitle">A New, Discontinuous 2 Phases of <span class="hlt">Aging</span> <span class="hlt">Model</span>: Lessons from Drosophila melanogaster</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tricoire, Hervé; Rera, Michael</p> <p>2015-01-01</p> <p><span class="hlt">Aging</span> is commonly described as being a continuous process affecting progressively organisms as time passes. This process results in a progressive decrease in individuals fitness through a wide range of both organismal–decreased motor activity, fertility, resistance to stress–and molecular phenotypes–decreased protein and energy homeostasis, impairment of insulin signaling. In the past 20 years, numerous genes have been identified as playing a major role in the <span class="hlt">aging</span> process, yet little is known about the events leading to that loss of fitness. We recently described an event characterized by a dramatic increase of intestinal permeability to a blue food dye in <span class="hlt">aging</span> flies committed to die within a few days. Importantly, flies showing this so called ‘Smurf’ phenotype are the only ones, among a population, to show various <span class="hlt">age</span>-related changes and exhibit a high-risk of impending death whatever their chronological <span class="hlt">age</span>. Thus, these observations suggest that instead of being one continuous phenomenon, <span class="hlt">aging</span> may be a discontinuous process well described by at least two distinguishable phases. In this paper we addressed this hypothesis by implementing a new 2 Phases of <span class="hlt">Aging</span> mathematiCal <span class="hlt">model</span> (2PAC <span class="hlt">model</span>) to simulate longevity curves based on the simple hypothesis of two consecutive phases of lifetime presenting different properties. We first present a unique equation for each phase and discuss the biological significance of the 3 associated parameters. Then we evaluate the influence of each parameter on the shape of survival curves. Overall, this new mathematical <span class="hlt">model</span>, based on simple biological observations, is able to reproduce many experimental longevity curves, supporting the existence of 2 phases of <span class="hlt">aging</span> exhibiting specific properties and separated by a dramatic transition that remains to be characterized. Moreover, it indicates that Smurf survival can be approximated by one single constant parameter for a broad range of genotypes that we have tested under</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ufm..conf..509K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ufm..conf..509K&link_type=ABSTRACT"><span id="translatedtitle">Universal Cosmic <span class="hlt">Absolute</span> and Modern Science</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kostro, Ludwik</p> <p></p> <p>The official Sciences, especially all natural sciences, respect in their researches the principle of methodic naturalism i.e. they consider all phenomena as entirely natural and therefore in their scientific explanations they do never adduce or cite supernatural entities and forces. The purpose of this paper is to show that Modern Science has its own self-existent, self-acting, and self-sufficient Natural All-in Being or Omni-Being i.e. the entire Nature as a Whole that justifies the scientific methodic naturalism. Since this Natural All-in Being is one and only It should be considered as the own scientifically justified Natural <span class="hlt">Absolute</span> of Science and should be called, in my opinion, the Universal Cosmic <span class="hlt">Absolute</span> of Modern Science. It will be also shown that the Universal Cosmic <span class="hlt">Absolute</span> is ontologically enormously stratified and is in its ultimate i.e. in its most fundamental stratum trans-reistic and trans-personal. It means that in its basic stratum. It is neither a Thing or a Person although It contains in Itself all things and persons with all other sentient and conscious individuals as well, On the turn of the 20th century the Science has begun to look for a theory of everything, for a final theory, for a master theory. In my opinion the natural Universal Cosmic <span class="hlt">Absolute</span> will constitute in such a theory the radical all penetrating Ultimate Basic Reality and will substitute step by step the traditional supernatural personal <span class="hlt">Absolute</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.7814M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.7814M"><span id="translatedtitle">Four Years of <span class="hlt">Absolute</span> Gravity in the Taiwan Orogen (AGTO)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mouyen, Maxime; Masson, Frédéric; Hwang, Cheinway; Cheng, Ching-Chung; Le Moigne, Nicolas; Lee, Chiung-Wu; Kao, Ricky; Hsieh, Nicky</p> <p>2010-05-01</p> <p>AGTO is a scientific project between Taiwanese and French institutes, which aim is to improve tectonic knowledge of Taiwan primarily using <span class="hlt">absolute</span> gravity measurements and permanent GPS stations. Both tools are indeed useful to study vertical movements and mass transfers involved in mountain building, a major process in Taiwan located at the convergent margin between Philippine Sea plate and Eurasian plate. This convergence results in two subductions north and south of Taiwan (Ryukyu and Manilla trenches, respectively), while the center is experiencing collision. These processes make Taiwan very active tectonically, as illustrated by numerous large earthquakes and rapid uplift of the Central Range. High slopes of Taiwan mountains and heavy rains brought by typhoons together lead to high landslides and mudflows risks. Practically, <span class="hlt">absolute</span> gravity measurements have been yearly repeated since 2006 along a transect across south Taiwan, from Penghu to Lutao islands, using FG5 <span class="hlt">absolute</span> gravimeters. This transect contains ten sites for <span class="hlt">absolute</span> measurements and has been densified in 2008 by incorporating 45 sites for relative gravity measurements with CG5 gravimeters. The last relative and <span class="hlt">absolute</span> measurements have been performed in November 2009. Most of the <span class="hlt">absolute</span> sites have been measured with a good accuracy, about 1 or 2 ?Gal. Only the site located in Tainan University has higher standard deviation, due to the city noise. We note that <span class="hlt">absolute</span> gravity changes seem to follow a trend in every site. However, straightforward tectonic interpretation of these trends is not valuable as many non-tectonic effects are supposed to change g with time, like groundwater or erosion. Estimating and removing these effects leads to a tectonic gravity signal, which has theoretically two origins : deep mass transfers around the site and vertical movements of the station. The latter can be well constrained by permanent GPS stations located close to the measurement pillar. Deep mass</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4258866','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4258866"><span id="translatedtitle">Quantification the Effect of <span class="hlt">Ageing</span> on Characteristics of the Photoplethysmogram Using an Optimized Windkessel <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Doostdar, H; Khalilzadeh, MA</p> <p>2014-01-01</p> <p>Background: With increasing <span class="hlt">age</span>, some changes appeared in specifications of vessels which including dimensions and elasticity in theirs. The changes in parameters such as resistance, inertance and compliance vessels appear and eventually changes in the environmental pulse releases are in circulation. These changes clearly appear in specification of photoplethysmogram particularly in the size and position signals second peak is observed. Aim and scope: The aim of study was to Circulatory system <span class="hlt">modeling</span> using windkessel electrical <span class="hlt">model</span>  for evalution blood flow  and Its matching with the photoplethysmogram’s signal for investigate the reasons for changes of Characteristics of the Photoplethysmogram. The first purpose of this paper is to examine the <span class="hlt">age</span>-related parameters in the Photoplethysmogram’s signal and finally the diagnosis of cardiovascular disease using the <span class="hlt">model</span> and photoplethysmogram’s signal. Methods: In this study we followed some of these effects to the circulatory system by using the windkessel electrical <span class="hlt">model</span>. The algorithm in this project appeared by optimization with the matrix coefficients of state space windkessel electrical <span class="hlt">model</span>. Optimize of the coefficients matching with the output of the <span class="hlt">model</span> and the photoplethysmogram’s signal. Photoplethysmogram’s signals from 50 healthy subjects with the <span class="hlt">age</span> range of 20 to 50 years, shows that outputs the <span class="hlt">model</span> and photoplethysmogram’s signal in terms of error rate and cross-correlation algorithm in a fully automate, was consistent. Wavelength of the Photoplethysmogram’s signals were 950 nm and The sampling rate was set at 50 Hz. Results: Simulation results show that <span class="hlt">aging</span> reduces the signal amplitude and delay of the second peak occurs. These changes were seen as reduce the rate of compliance and increase the rate of resistance and inertance windkessel electrical <span class="hlt">model</span> of circulation. Conclusion: The high accuracy of the results led to being able to identify the <span class="hlt">age</span> range and some</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFM.A53W..04H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFM.A53W..04H&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Modeling</span> the formation and <span class="hlt">aging</span> of secondary organic aerosols during CalNex 2010</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayes, P. L.; Ortega, A. M.; Ahmadov, R.; McKeen, S. A.; Washenfelder, R. A.; Alvarez, S.; Rappenglueck, B.; Holloway, J. S.; Gilman, J. B.; Kuster, W. C.; De Gouw, J. A.; Zotter, P.; Prevot, A. S.; Kleindienst, T. E.; Offenberg, J. H.; Jimenez, J. L.</p> <p>2012-12-01</p> <p>Several traditional and recently proposed <span class="hlt">models</span> are applied to predict the concentrations and properties of secondary organic aerosols (SOA) and organic gases at the Pasadena ground site during the CalNex campaign. The <span class="hlt">models</span> are constrained with and compared against results from available observations. The CalNex campaign and specifically the Pasadena ground site featured a large and sophisticated suite of aerosol and gas phase instrumentation, and thus, it provides a unique opportunity to test SOA <span class="hlt">models</span> under conditions of strong urban emissions at a range of low photochemical <span class="hlt">ages</span>. The oxidation of volatile organic compounds (VOCs) using an updated traditional <span class="hlt">model</span> cannot explain the observed ambient SOA, and under-predicts the measurements by a factor of ~40. Similarly, after accounting for the multi-generation oxidation of VOCs using a volatility basis set (VBS) approach as described by Tsimpidi et al. (2010), SOA is still under-predicted by a factor of ~8. For SOA formed from VOCs (V-SOA) the dominant precursors are aromatics (xylenes, toluene, and trimethylbenzenes). The <span class="hlt">model</span> SOA formed from the oxidation of primary semivolatile and intermediate volatility organic compounds (P-S/IVOCs, producing SI-SOA) is also predicted using the parameterizations of Robinson et al. (2007) and Grieshop et al. (2009), and the properties of V-SOA + SI-SOA are compared against the measured O:C and volatility. We also compare the results of the different <span class="hlt">models</span> against fossil/non-fossil carbon measurements as well as tracers of different SOA precursors. Potential Aerosol Mass (PAM) measurements of the SOA forming potential of the Pasadena air masses are also compared against that predicted by the <span class="hlt">models</span>. The PAM analysis allows for <span class="hlt">model</span>/measurement comparisons of SOA properties over a range of photochemical <span class="hlt">ages</span> spanning almost two weeks. Using the V-SOA <span class="hlt">model</span>, at low photochemical <span class="hlt">ages</span> (< 1 day) the <span class="hlt">modeled</span> PAM V-SOA is less than the measured PAM SOA, similar to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015JSP...159..158B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015JSP...159..158B&link_type=ABSTRACT"><span id="translatedtitle">On the <span class="hlt">Absolute</span> Continuity of the Blackwell Measure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bárány, Balázs; Kolossváry, István</p> <p>2015-04-01</p> <p>In 1957, Blackwell expressed the entropy of hidden Markov chains using a measure which can be characterised as an invariant measure for an iterated function system with place-dependent weights. This measure, called the Blackwell measure, plays a central role in understanding the entropy rate and other important characteristics of fundamental <span class="hlt">models</span> in information theory. We show that for a suitable set of parameter values the Blackwell measure is <span class="hlt">absolutely</span> continuous for almost every parameter in the case of binary symmetric channels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9585593','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9585593"><span id="translatedtitle">A <span class="hlt">model</span> for antagonistic pleiotropic gene action for mortality and advanced <span class="hlt">age</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Toupance, B; Godelle, B; Gouyon, P H; Schächter, F</p> <p>1998-06-01</p> <p>Association or linkage studies involving control and long-lived populations provide information on genes that influence longevity. However, the relationship between allele-specific differences in survival and the genetic structure of <span class="hlt">aging</span> cohorts remains unclear. We <span class="hlt">model</span> a heterogeneous cohort comprising several genotypes differing in <span class="hlt">age</span>-specific mortality. In its most general form, without any specific assumption regarding the shape of mortality curves, the <span class="hlt">model</span> permits derivation of a fundamental property underlying abrupt <span class="hlt">age</span>-related changes in the composition of a cohort. The <span class="hlt">model</span> is applied to sex-specific survival curves taken from period life tables, and Gompertz-Makeham mortality coefficients are calculated for the French population. Then, adjustments are performed under Gompertz-Makeham mortality functions for three genotypes composing a heterogeneous cohort, under the constraint of fitting the resultant mortality to the real French population mortality obtained from life tables. Multimodal curves and divergence after the 8th decade appear as recurrent features of the frequency trajectories. Finally, a fit to data previously obtained at the angiotensin-converting-enzyme locus is realized, explaining what had seemed to be paradoxical results-namely, that the frequency of a genotype known as a cardiovascular risk factor was increased in centenarians. Our results help explain the well-documented departure from Gompertz-Makeham mortality kinetics at older <span class="hlt">ages</span>. The implications of our <span class="hlt">model</span> are discussed in the context of known genetic effects on human longevity and <span class="hlt">age</span>-related pathologies. Since antagonistic pleiotropy between early and late survival emerges as a general rule, extrapolating the effects measured for a gene in a particular <span class="hlt">age</span> class to other <span class="hlt">ages</span> could be misleading. PMID:9585593</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4824877','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4824877"><span id="translatedtitle"><span class="hlt">Aging</span> and serum MCP-1 are associated with gut microbiome composition in a murine <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Conley, Melissa N.; Wong, Carmen P.; Duyck, Kyle M.; Hord, Norman; Ho, Emily</p> <p>2016-01-01</p> <p>Introduction. <span class="hlt">Age</span> is the primary risk factor for major human chronic diseases, including cardiovascular disorders, cancer, type 2 diabetes, and neurodegenerative diseases. Chronic, low-grade, systemic inflammation is associated with <span class="hlt">aging</span> and the progression of immunosenescence. Immunosenescence may play an important role in the development of <span class="hlt">age</span>-related chronic disease and the widely observed phenomenon of increased production of inflammatory mediators that accompany this process, referred to as “inflammaging.” While it has been demonstrated that the gut microbiome and immune system interact, the relationship between the gut microbiome and <span class="hlt">age</span> remains to be clearly defined, particularly in the context of inflammation. The aim of our study was to clarify the associations between <span class="hlt">age</span>, the gut microbiome, and pro-inflammatory marker serum MCP-1 in a C57BL/6 murine <span class="hlt">model</span>. Results. We used 16S rRNA gene sequencing to profile the composition of fecal microbiota associated with young and <span class="hlt">aged</span> mice. Our analysis identified an association between microbiome structure and mouse <span class="hlt">age</span> and revealed specific groups of taxa whose abundances stratify young and <span class="hlt">aged</span> mice. This includes the Ruminococcaceae, Clostridiaceae, and Enterobacteriaceae. We also profiled pro-inflammatory serum MCP-1 levels of each mouse and found that <span class="hlt">aged</span> mice exhibited elevated serum MCP-1, a phenotype consistent with inflammaging. Robust correlation tests identified several taxa whose abundance in the microbiome associates with serum MCP-1 status, indicating that they may interact with the mouse immune system. We find that taxonomically similar organisms can exhibit differing, even opposite, patterns of association with the host immune system. We also find that many of the OTUs that associate with serum MCP-1 stratify individuals by <span class="hlt">age</span>. Discussion. Our results demonstrate that gut microbiome composition is associated with <span class="hlt">age</span> and the pro-inflammatory marker, serum MCP-1. The correlation between <span class="hlt">age</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27069796','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27069796"><span id="translatedtitle"><span class="hlt">Aging</span> and serum MCP-1 are associated with gut microbiome composition in a murine <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Conley, Melissa N; Wong, Carmen P; Duyck, Kyle M; Hord, Norman; Ho, Emily; Sharpton, Thomas J</p> <p>2016-01-01</p> <p>Introduction. <span class="hlt">Age</span> is the primary risk factor for major human chronic diseases, including cardiovascular disorders, cancer, type 2 diabetes, and neurodegenerative diseases. Chronic, low-grade, systemic inflammation is associated with <span class="hlt">aging</span> and the progression of immunosenescence. Immunosenescence may play an important role in the development of <span class="hlt">age</span>-related chronic disease and the widely observed phenomenon of increased production of inflammatory mediators that accompany this process, referred to as "inflammaging." While it has been demonstrated that the gut microbiome and immune system interact, the relationship between the gut microbiome and <span class="hlt">age</span> remains to be clearly defined, particularly in the context of inflammation. The aim of our study was to clarify the associations between <span class="hlt">age</span>, the gut microbiome, and pro-inflammatory marker serum MCP-1 in a C57BL/6 murine <span class="hlt">model</span>. Results. We used 16S rRNA gene sequencing to profile the composition of fecal microbiota associated with young and <span class="hlt">aged</span> mice. Our analysis identified an association between microbiome structure and mouse <span class="hlt">age</span> and revealed specific groups of taxa whose abundances stratify young and <span class="hlt">aged</span> mice. This includes the Ruminococcaceae, Clostridiaceae, and Enterobacteriaceae. We also profiled pro-inflammatory serum MCP-1 levels of each mouse and found that <span class="hlt">aged</span> mice exhibited elevated serum MCP-1, a phenotype consistent with inflammaging. Robust correlation tests identified several taxa whose abundance in the microbiome associates with serum MCP-1 status, indicating that they may interact with the mouse immune system. We find that taxonomically similar organisms can exhibit differing, even opposite, patterns of association with the host immune system. We also find that many of the OTUs that associate with serum MCP-1 stratify individuals by <span class="hlt">age</span>. Discussion. Our results demonstrate that gut microbiome composition is associated with <span class="hlt">age</span> and the pro-inflammatory marker, serum MCP-1. The correlation between <span class="hlt">age</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27493076','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27493076"><span id="translatedtitle">Advanced <span class="hlt">age</span> negatively impacts survival in an experimental brain tumor <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ladomersky, Erik; Zhai, Lijie; Gritsina, Galina; Genet, Matthew; Lauing, Kristen L; Wu, Meijing; James, C David; Wainwright, Derek A</p> <p>2016-09-01</p> <p>Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, with an average <span class="hlt">age</span> of 64 years at the time of diagnosis. To study GBM, a number of mouse brain tumor <span class="hlt">models</span> have been utilized. In these animal <span class="hlt">models</span>, subjects tend to range from 6 to 12 weeks of <span class="hlt">age</span>, which is analogous to that of a human teenager. Here, we examined the impact of <span class="hlt">age</span> on host immunity and the gene expression associated with immune evasion in immunocompetent mice engrafted with syngeneic intracranial GL261. The data indicate that, in mice with brain tumors, youth conveys an advantage to survival. While <span class="hlt">age</span> did not affect the tumor-infiltrating T cell phenotype or quantity, we discovered that old mice express higher levels of the immunoevasion enzyme, IDO1, which was decreased by the presence of brain tumor. Interestingly, other genes associated with promoting immunosuppression including CTLA-4, PD-L1 and FoxP3, were unaffected by <span class="hlt">age</span>. These data highlight the possibility that IDO1 contributes to faster GBM outgrowth with advanced <span class="hlt">age</span>, providing rationale for future investigation into immunotherapeutic targeting in the future. PMID:27493076</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/964073','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/964073"><span id="translatedtitle">230Th-234U <span class="hlt">Model-Ages</span> of Some Uranium Standard Reference Materials</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Williams, R W; Gaffney, A M; Kristo, M J; Hutcheon, I D</p> <p>2009-05-28</p> <p>The '<span class="hlt">age</span>' of a sample of uranium is an important aspect of a nuclear forensic investigation and of the attribution of the material to its source. To the extent that the sample obeys the standard rules of radiochronometry, then the production <span class="hlt">ages</span> of even very recent material can be determined using the {sup 230}Th-{sup 234}U chronometer. These standard rules may be summarized as (a) the daughter/parent ratio at time=zero must be known, and (b) there has been no daughter/parent fractionation since production. For most samples of uranium, the '<span class="hlt">ages</span>' determined using this chronometer are semantically '<span class="hlt">model-ages</span>' because (a) some assumption of the initial {sup 230}Th content in the sample is required and (b) closed-system behavior is assumed. The uranium standard reference materials originally prepared and distributed by the former US National Bureau of Standards and now distributed by New Brunswick Laboratory as certified reference materials (NBS SRM = NBL CRM) are good candidates for samples where both rules are met. The U isotopic standards have known purification and production dates, and closed-system behavior in the solid form (U{sub 3}O{sub 8}) may be assumed with confidence. We present here {sup 230}Th-{sup 234}U <span class="hlt">model-ages</span> for several of these standards, determined by isotope dilution mass spectrometry using a multicollector ICP-MS, and compare these <span class="hlt">ages</span> with their known production history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4758832','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4758832"><span id="translatedtitle"><span class="hlt">Modeling</span> early-onset post-ischemic seizures in <span class="hlt">aging</span> mice</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, Chiping; Wang, Justin; Peng, Jessie; Patel, Nisarg; Huang, Yayi; Gao, Xiaoxing; Aljarallah, Salman; Eubanks, James H; McDonald, Robert; Zhang, Liang</p> <p>2016-01-01</p> <p>Stroke is the leading cause of seizures and epilepsy in the <span class="hlt">aged</span> population, with post-stroke seizures being a poor prognostic factor. The pathological processes underlying post-stroke seizures are not well understood and studies of these seizures in <span class="hlt">aging/aged</span> animals remain scarce. Therefore, our primary objective was to <span class="hlt">model</span> post-stroke seizures in <span class="hlt">aging</span> mice (C57 black strain, 16–20 month-old), with a focus on early-onset, convulsive seizures that occur within 24-hours of brain ischemia. We utilized a middle cerebral artery occlusion <span class="hlt">model</span> and examined seizure activity and brain injury using combined behavioral and electroencephalographic monitoring and histological assessments. <span class="hlt">Aging</span> mice exhibited vigorous convulsive seizures within hours of the middle cerebral artery occlusion. These seizures manifested with jumping, rapid running, barrel-rolling and/or falling all in the absence of hippocampal-cortical electrographic discharges. Seizure development was closely associated with severe brain injury and acute mortality. Anticonvulsive treatments after seizure occurrence offered temporary seizure control but failed to improve animal survival. A separate cohort of adult mice (6–8 months-old) exhibited analogous early-onset convulsive seizures following the middle cerebral artery occlusion but had better survival outcomes following anticonvulsive treatment. Collectively, our data suggest that early-onset convulsive seizures are a result of severe brain ischemia in <span class="hlt">aging</span> animals. PMID:25943585</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985GeCoA..49..835N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985GeCoA..49..835N"><span id="translatedtitle"><span class="hlt">Absolute</span> isotopic abundances of TI in meteorites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niederer, F. R.; Papanastassiou, D. A.; Wasserburg, G. J.</p> <p>1985-03-01</p> <p>The <span class="hlt">absolute</span> isotope abundance of Ti has been determined in Ca-Al-rich inclusions from the Allende and Leoville meteorites and in samples of whole meteorites. The <span class="hlt">absolute</span> Ti isotope abundances differ by a significant mass dependent isotope fractionation transformation from the previously reported abundances, which were normalized for fractionation using 46Ti/48Ti. Therefore, the <span class="hlt">absolute</span> compositions define distinct nucleosynthetic components from those previously identified or reflect the existence of significant mass dependent isotope fractionation in nature. The authors provide a general formalism for determining the possible isotope compositions of the exotic Ti from the measured composition, for different values of isotope fractionation in nature and for different mixing ratios of the exotic and normal components.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/371207','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/371207"><span id="translatedtitle">Molecular iodine <span class="hlt">absolute</span> frequencies. Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sansonetti, C.J.</p> <p>1990-06-25</p> <p>Fifty specified lines of {sup 127}I{sub 2} were studied by Doppler-free frequency modulation spectroscopy. For each line the classification of the molecular transition was determined, hyperfine components were identified, and one well-resolved component was selected for precise determination of its <span class="hlt">absolute</span> frequency. In 3 cases, a nearby alternate line was selected for measurement because no well-resolved component was found for the specified line. <span class="hlt">Absolute</span> frequency determinations were made with an estimated uncertainty of 1.1 MHz by locking a dye laser to the selected hyperfine component and measuring its wave number with a high-precision Fabry-Perot wavemeter. For each line results of the <span class="hlt">absolute</span> measurement, the line classification, and a Doppler-free spectrum are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6063303','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6063303"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration in vivo measurement systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kruchten, D.A.; Hickman, D.P.</p> <p>1991-02-01</p> <p>Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining <span class="hlt">absolute</span> calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. <span class="hlt">Absolute</span> calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The <span class="hlt">absolute</span> calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3945218','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3945218"><span id="translatedtitle">Ovarian <span class="hlt">Aging</span>-Like Phenotype in the Hyperandrogenism-Induced Murine <span class="hlt">Model</span> of Polycystic Ovary</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rezvanfar, Mohammad Amin; Shojaei Saadi, Habib A.; Gooshe, Maziar; Abdolghaffari, Amir Hosein; Baeeri, Maryam; Abdollahi, Mohammad</p> <p>2014-01-01</p> <p>There are prominently similar symptoms, effectors, and commonalities in the majority of characteristics between ovarian <span class="hlt">aging</span> and polycystic ovarian syndrome (PCOS). Despite the approved role of oxidative stress in the pathogenesis of PCOS and <span class="hlt">aging</span>, to our knowledge, the link between the PCO(S) and <span class="hlt">aging</span> has not been investigated yet. In this study we investigated the possible exhibition of ovarian <span class="hlt">aging</span> phenotype in murine <span class="hlt">model</span> of PCO induced by daily oral administration of letrozole (1 mg/kg body weight) for 21 consecutive days in the female Wistar rats. Hyperandrogenization showed irregular cycles and histopathological characteristics of PCO which was associated with a significant increase in lipid peroxidation (LPO) and reactive oxygen species (ROS) and decrease in total antioxidant capacity (TAC) in serum and ovary. Moreover, serum testosterone, insulin and tumor necrosis factor-alpha (TNF-α) levels, and ovarian matrix metalloproteinase-2 (MMP-2) were increased in PCO rats compared with healthy controls, while estradiol and progesterone diminished. Almost all of these findings are interestingly found to be common with the characteristics identified with (ovarian) <span class="hlt">aging</span> showing that hyperandrogenism-induced PCO in rat is associated with ovarian <span class="hlt">aging</span>-like phenotypes. To our knowledge, this is the first report that provides evidence regarding the phenomenon of <span class="hlt">aging</span> in PCO. PMID:24693338</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4798846','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4798846"><span id="translatedtitle"><span class="hlt">Age</span>-associated changes in DNA methylation across multiple tissues in an inbred mouse <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Spiers, Helen; Hannon, Eilis; Wells, Sara; Williams, Brenda; Fernandes, Cathy; Mill, Jonathan</p> <p>2016-01-01</p> <p>Epigenetic disruption has been implicated in many diseases of <span class="hlt">aging</span>, and <span class="hlt">age</span>-associated DNA methylation changes at specific genomic loci in humans are strongly correlated with chronological <span class="hlt">age</span>. The aim of this study was to explore the specificity of selected <span class="hlt">age</span>-associated differentially methylated positions (aDMPs) identified in human epidemiological studies by quantifying DNA methylation across multiple tissues in homologous regions of the murine genome. We selected four high-confidence aDMPs (located in the vicinity of the ELOVL2, GLRA1, MYOD1 and PDE4C genes) and quantified DNA methylation across these regions in four tissues (blood, lung, cerebellum and hippocampus) from male and female C57BL/6J mice, ranging in <span class="hlt">age</span> from fetal (embryonic day 17) to 630 days. We observed tissue-specific <span class="hlt">age</span>-associated changes in DNA methylation that was directionally consistent with those observed in humans. These findings lend further support to the notion that changes in DNA methylation are associated with chronological <span class="hlt">age</span> and suggest that these processes are often conserved across tissues and between mammalian species. Our data highlight the relevance of utilizing <span class="hlt">model</span> systems, in which environmental and genetic influences can be carefully controlled, for the further study of these phenomena. PMID:26861500</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24693338','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24693338"><span id="translatedtitle">Ovarian <span class="hlt">aging</span>-like phenotype in the hyperandrogenism-induced murine <span class="hlt">model</span> of polycystic ovary.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rezvanfar, Mohammad Amin; Shojaei Saadi, Habib A; Gooshe, Maziar; Abdolghaffari, Amir Hosein; Baeeri, Maryam; Abdollahi, Mohammad</p> <p>2014-01-01</p> <p>There are prominently similar symptoms, effectors, and commonalities in the majority of characteristics between ovarian <span class="hlt">aging</span> and polycystic ovarian syndrome (PCOS). Despite the approved role of oxidative stress in the pathogenesis of PCOS and <span class="hlt">aging</span>, to our knowledge, the link between the PCO(S) and <span class="hlt">aging</span> has not been investigated yet. In this study we investigated the possible exhibition of ovarian <span class="hlt">aging</span> phenotype in murine <span class="hlt">model</span> of PCO induced by daily oral administration of letrozole (1 mg/kg body weight) for 21 consecutive days in the female Wistar rats. Hyperandrogenization showed irregular cycles and histopathological characteristics of PCO which was associated with a significant increase in lipid peroxidation (LPO) and reactive oxygen species (ROS) and decrease in total antioxidant capacity (TAC) in serum and ovary. Moreover, serum testosterone, insulin and tumor necrosis factor-alpha (TNF-α) levels, and ovarian matrix metalloproteinase-2 (MMP-2) were increased in PCO rats compared with healthy controls, while estradiol and progesterone diminished. Almost all of these findings are interestingly found to be common with the characteristics identified with (ovarian) <span class="hlt">aging</span> showing that hyperandrogenism-induced PCO in rat is associated with ovarian <span class="hlt">aging</span>-like phenotypes. To our knowledge, this is the first report that provides evidence regarding the phenomenon of <span class="hlt">aging</span> in PCO. PMID:24693338</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26861500','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26861500"><span id="translatedtitle"><span class="hlt">Age</span>-associated changes in DNA methylation across multiple tissues in an inbred mouse <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Spiers, Helen; Hannon, Eilis; Wells, Sara; Williams, Brenda; Fernandes, Cathy; Mill, Jonathan</p> <p>2016-03-01</p> <p>Epigenetic disruption has been implicated in many diseases of <span class="hlt">aging</span>, and <span class="hlt">age</span>-associated DNA methylation changes at specific genomic loci in humans are strongly correlated with chronological <span class="hlt">age</span>. The aim of this study was to explore the specificity of selected <span class="hlt">age</span>-associated differentially methylated positions (aDMPs) identified in human epidemiological studies by quantifying DNA methylation across multiple tissues in homologous regions of the murine genome. We selected four high-confidence aDMPs (located in the vicinity of the ELOVL2, GLRA1, MYOD1 and PDE4C genes) and quantified DNA methylation across these regions in four tissues (blood, lung, cerebellum and hippocampus) from male and female C57BL/6J mice, ranging in <span class="hlt">age</span> from fetal (embryonic day 17) to 630 days. We observed tissue-specific <span class="hlt">age</span>-associated changes in DNA methylation that was directionally consistent with those observed in humans. These findings lend further support to the notion that changes in DNA methylation are associated with chronological <span class="hlt">age</span> and suggest that these processes are often conserved across tissues and between mammalian species. Our data highlight the relevance of utilizing <span class="hlt">model</span> systems, in which environmental and genetic influences can be carefully controlled, for the further study of these phenomena. PMID:26861500</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AIPC.1571.1062H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1571.1062H"><span id="translatedtitle">Structural <span class="hlt">modeling</span> of <span class="hlt">age</span> specific fertility curves in Peninsular Malaysia: An approach of Lee Carter method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanafiah, Hazlenah; Jemain, Abdul Aziz</p> <p>2013-11-01</p> <p>In recent years, the study of fertility has been getting a lot of attention among research abroad following fear of deterioration of fertility led by the rapid economy development. Hence, this study examines the feasibility of developing fertility forecasts based on <span class="hlt">age</span> structure. Lee Carter <span class="hlt">model</span> (1992) is applied in this study as it is an established and widely used <span class="hlt">model</span> in analysing demographic aspects. A singular value decomposition approach is incorporated with an ARIMA <span class="hlt">model</span> to estimate <span class="hlt">age</span> specific fertility rates in Peninsular Malaysia over the period 1958-2007. Residual plots is used to measure the goodness of fit of the <span class="hlt">model</span>. Fertility index forecast using random walk drift is then utilised to predict the future <span class="hlt">age</span> specific fertility. Results indicate that the proposed <span class="hlt">model</span> provides a relatively good and reasonable data fitting. In addition, there is an apparent and continuous decline in <span class="hlt">age</span> specific fertility curves in the next 10 years, particularly among mothers' in their early 20's and 40's. The study on the fertility is vital in order to maintain a balance between the population growth and the provision of facilities related resources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26501233','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26501233"><span id="translatedtitle">A four-component <span class="hlt">model</span> of <span class="hlt">age</span>-related memory change.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Healey, M Karl; Kahana, Michael J</p> <p>2016-01-01</p> <p>We develop a novel, computationally explicit, theory of <span class="hlt">age</span>-related memory change within the framework of the context maintenance and retrieval (CMR2) <span class="hlt">model</span> of memory search. We introduce a set of benchmark findings from the free recall and recognition tasks that include aspects of memory performance that show both <span class="hlt">age</span>-related stability and decline. We test <span class="hlt">aging</span> theories by lesioning the corresponding mechanisms in a <span class="hlt">model</span> fit to younger adult free recall data. When effects are considered in isolation, many theories provide an adequate account, but when all effects are considered simultaneously, the existing theories fail. We develop a novel theory by fitting the full <span class="hlt">model</span> (i.e., allowing all parameters to vary) to individual participants and comparing the distributions of parameter values for older and younger adults. This theory implicates 4 components: (a) the ability to sustain attention across an encoding episode, (b) the ability to retrieve contextual representations for use as retrieval cues, (c) the ability to monitor retrievals and reject intrusions, and (d) the level of noise in retrieval competitions. We extend CMR2 to simulate a recognition memory task using the same mechanisms the free recall <span class="hlt">model</span> uses to reject intrusions. Without fitting any additional parameters, the 4-component theory that accounts for <span class="hlt">age</span> differences in free recall predicts the magnitude of <span class="hlt">age</span> differences in recognition memory accuracy. Confirming a prediction of the <span class="hlt">model</span>, free recall intrusion rates correlate positively with recognition false alarm rates. Thus, we provide a 4-component theory of a complex pattern of <span class="hlt">age</span> differences across 2 key laboratory tasks. PMID:26501233</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990004341','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990004341"><span id="translatedtitle">Constitutive <span class="hlt">Modeling</span> and Testing of Polymer Matrix Composites Incorporating Physical <span class="hlt">Aging</span> at Elevated Temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Veazie, David R.</p> <p>1998-01-01</p> <p>Advanced polymer matrix composites (PMC's) are desirable for structural materials in diverse applications such as aircraft, civil infrastructure and biomedical implants because of their improved strength-to-weight and stiffness-to-weight ratios. For example, the next generation military and commercial aircraft requires applications for high strength, low weight structural components subjected to elevated temperatures. A possible disadvantage of polymer-based composites is that the physical and mechanical properties of the matrix often change significantly over time due to the exposure of elevated temperatures and environmental factors. For design, long term exposure (i.e. <span class="hlt">aging</span>) of PMC's must be accounted for through constitutive <span class="hlt">models</span> in order to accurately assess the effects of <span class="hlt">aging</span> on performance, crack initiation and remaining life. One particular aspect of this <span class="hlt">aging</span> process, physical <span class="hlt">aging</span>, is considered in this research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4567220','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4567220"><span id="translatedtitle">Mechanisms of Muscle Denervation in <span class="hlt">Aging</span>: Insights from a Mouse <span class="hlt">Model</span> of Amyotrophic Lateral Sclerosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Park, Kevin H.J</p> <p>2015-01-01</p> <p>Muscle denervation at the neuromuscular junction (NMJ) is thought to be a contributing factor in <span class="hlt">age</span>-related muscle weakness. Therefore, understanding the mechanisms that modulate NMJ innervation is a key to developing therapies to combat <span class="hlt">age</span>-related muscle weakness affecting the elderly. Two mouse <span class="hlt">models</span>, one lacking the Cu/Zn superoxide dismutase (SOD1) gene and another harboring the transgenic mutant human SOD1 gene, display progressive changes at the NMJ, including muscle endplate fragmentation, nerve terminal sprouting, and denervation. These changes at the NMJ share many of the common features observed in the NMJs of <span class="hlt">aged</span> mice. In this review, research findings demonstrating the effects of PGC-1α, IGF-1, GDNF, MyoD, myogenin, and miR-206 on NMJ innervation patterns in the G93A SOD1 mice will be highlighted in the context of <span class="hlt">age</span>-related muscle denervation. PMID:26425392</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16307858','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16307858"><span id="translatedtitle">Decreased plasma cholesterol levels during <span class="hlt">aging</span> in transgenic mouse <span class="hlt">models</span> of Alzheimer's disease.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wirths, Oliver; Thelen, Karin; Breyhan, Henning; Luzón-Toro, Berta; Hoffmann, Karl-Heinz; Falkai, Peter; Lütjohann, Dieter; Bayer, Thomas A</p> <p>2006-02-01</p> <p>A large number of studies deals with the association of cholesterol and Abeta levels, however, the results are so far controversial. Whereas some studies report on increased cholesterol levels, other authors refer to an association of decreased peripheral cholesterol and the incidence of Alzheimer's disease. It is also questionable whether plasma cholesterol levels could be used as a predictive biomarker for the incidence of Alzheimer's disease. In the present report, we studied the relationship between these two parameters during <span class="hlt">aging</span> in different transgenic mouse <span class="hlt">models</span> of Alzheimer's disease, expressing both mutant human amyloid precursor protein and mutant human presenilin-1. Measurements of plasma cholesterol levels revealed a significant reduction in <span class="hlt">aged</span> APP/PS1 and APP/PS1ki mice, whereas plasma levels in young and <span class="hlt">aged</span> control mice remained almost unchanged. Furthermore, statistical analysis revealed a significant negative correlation between plasma cholesterol and brain Abeta42 levels during <span class="hlt">aging</span> in the mice expressing both APP and PS1. PMID:16307858</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.138lA528S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.138lA528S"><span id="translatedtitle">Evolution of collective motion in a <span class="hlt">model</span> glass-forming liquid during physical <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shavit, Amit; Douglas, Jack F.; Riggleman, Robert A.</p> <p>2013-03-01</p> <p>At temperatures moderately below their glass transition temperature, the properties of many glass-forming materials can evolve slowly with time in a process known as physical <span class="hlt">aging</span> whereby the thermodynamic, mechanical, and dynamic properties all drift towards their equilibrium values. In this work, we study the evolution of the thermodynamic and dynamic properties during physical <span class="hlt">aging</span> for a <span class="hlt">model</span> polymer glass. Specifically, we test the relationship between an estimate of the size of the cooperative rearrangements taking the form of strings and the effective structural relaxation time predicted by the Adam-Gibbs relationship for both an equilibrium supercooled liquid and the same fluid undergoing physical <span class="hlt">aging</span> towards equilibrium after a series of temperature jumps. We find that there is apparently a close correlation between a structural feature of the fluid, the size of the string-like rearrangements, and the structural relaxation time, although the relationship for the <span class="hlt">aging</span> fluid appears to be distinct from that of the fluid at equilibrium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940024091&hterms=beer+lambert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbeer%2Blambert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940024091&hterms=beer+lambert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbeer%2Blambert"><span id="translatedtitle"><span class="hlt">Absolute</span> determination of local tropospheric OH concentrations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Armerding, Wolfgang; Comes, Franz-Josef</p> <p>1994-01-01</p> <p>Long path absorption (LPA) according to Lambert Beer's law is a method to determine <span class="hlt">absolute</span> concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with <span class="hlt">model</span> calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3738220','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3738220"><span id="translatedtitle"><span class="hlt">Age</span>-Dependent Changes in FasL (CD95L) Modulate Macrophage Function in a <span class="hlt">Model</span> of <span class="hlt">Age</span>-Related Macular Degeneration</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhao, Hui; Roychoudhury, Jayeeta; Doggett, Teresa A.; Apte, Rajendra S.; Ferguson, Thomas A.</p> <p>2013-01-01</p> <p>Purpose. We examined the effect of <span class="hlt">aging</span> on Fas ligand (FasL) function in a mouse <span class="hlt">model</span> of choroidal neovascularization (CNV). Methods. Young and <span class="hlt">aged</span> mice were laser treated to induce CNV. Bone marrow chimeras were performed between young and <span class="hlt">aged</span> mice. FasL protein expression was examined in the eye and soluble FasL (sFasL) was measured in the blood. Young and <span class="hlt">aged</span> mice were treated with a matrix metalloprotease (MMP) inhibitor and systemic sFasL was neutralized by antibody treatment. Macrophages from young and <span class="hlt">aged</span> mice were tested for sFasL-mediated cytokine production and migration. Results. The elevated CNV response observed with <span class="hlt">aging</span> was dependent on bone marrow–derived cells. FasL expression in the eye was increased with <span class="hlt">age</span>, but decreased following laser treatment. <span class="hlt">Aged</span> mice had higher levels of sFasL in the blood compared to young mice. Systemic treatment with an MMP inhibitor decreased bloodborne sFasL, and reduced CNV in young and <span class="hlt">aged</span> mice. Systemic neutralization of sFasL reduced CNV only in <span class="hlt">aged</span> mice. sFasL increased cytokine production in <span class="hlt">aged</span> macrophages and proangiogenic M2 macrophages. <span class="hlt">Aged</span> M2 macrophages had elevated Fas (CD95) expression and displayed increased migration in response to sFasL compared to M1 macrophages derived from young animals. Conclusions. <span class="hlt">Age</span> modulates FasL function where increased MMP cleavage leads to a loss of function in the eye. The released form of FasL (sFasL) preferentially induces the migration of proangiogenic M2 macrophages into the laser lesions and increases proangiogenic cytokines promoting CNV. FasL may be a viable target for therapeutic intervention in <span class="hlt">aged</span>-related neovascular disease. PMID:23821188</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27169673','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27169673"><span id="translatedtitle"><span class="hlt">Age</span> estimation based on pelvic ossification using regression <span class="hlt">models</span> from conventional radiography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Kui; Dong, Xiao-Ai; Fan, Fei; Deng, Zhen-Hua</p> <p>2016-07-01</p> <p>To establish regression <span class="hlt">models</span> for <span class="hlt">age</span> estimation from the combination of the ossification of iliac crest and ischial tuberosity. One thousand three hundred and seventy-nine conventional pelvic radiographs at the West China Hospital of Sichuan University between January 2010 and June 2012 were evaluated retrospectively. The receiver operating characteristic analysis was performed to measure the value of estimation of 18 years of <span class="hlt">age</span> with the classification scheme for the iliac crest and ischial tuberosity. Regression analysis was performed, and formulas for calculating approximate chronological <span class="hlt">age</span> according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity were developed. The areas under the receiver operating characteristic (ROC) curves were above 0.9 (p < 0.001), indicating a good prediction of the grading systems, and the cubic regression <span class="hlt">model</span> was found to have the highest R-square value (R (2) = 0.744 for female and R (2) = 0.753 for male). The present classification scheme for apophyseal iliac crest ossification and the ischial tuberosity may be used for <span class="hlt">age</span> estimation. And the present established cubic regression <span class="hlt">model</span> according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity can be used for <span class="hlt">age</span> estimation. PMID:27169673</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4158465','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4158465"><span id="translatedtitle">Active <span class="hlt">Aging</span> for Individuals with Parkinson's Disease: Definitions, Literature Review, and <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lökk, Johan</p> <p>2014-01-01</p> <p>Active <span class="hlt">aging</span> has been emerged to optimize different aspects of health opportunities during the <span class="hlt">aging</span> process in order to enhance quality of life. Yet, most of the efforts are on normal <span class="hlt">aging</span> and less attention has been paid for the elderly suffering from a chronic illness such as Parkinson's disease (PD). The aim of this review was to investigate how the concept of “active aging” fit for the elderly with PD and to propose a new <span class="hlt">model</span> for them using the recent improvements in caring <span class="hlt">models</span> and management approaches. For this purpose, biomedical databases have been assessed using relevant keywords to find out appropriate articles. Movement problems of PD affect physical activity, psychiatric symptoms lessen social communication, and cognitive impairment could worsen mental well-being in elderly with PD, all of which could lead to earlier retirement and poorer quality of life compared with healthy elderly. Based on the multisystematic nature of PD, a new “Active <span class="hlt">Aging</span> <span class="hlt">Model</span> for Parkinson's Disease” is proposed consisting of self-care, multidisciplinary and interdisciplinary care, palliative care, patient-centered care, and personalized care. These strategies could potentially help the individuals with PD to have a better management approach for their condition towards the concept of active <span class="hlt">aging</span>. PMID:25225618</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4905658','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4905658"><span id="translatedtitle">A Validated Normative <span class="hlt">Model</span> for Human Uterine Volume from Birth to <span class="hlt">Age</span> 40 Years</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ginbey, Eleanor; Chowdhury, Moti M.; Bath, Louise E.; Anderson, Richard A.; Wallace, W. Hamish B.</p> <p>2016-01-01</p> <p>Transabdominal pelvic ultrasound and/or pelvic Magnetic Resonance Imaging are safe, accurate and non-invasive means of determining the size and configuration of the internal female genitalia. The assessment of uterine size and volume is helpful in the assessment of many conditions including disorders of sex development, precocious or delayed puberty, infertility and menstrual disorders. Using our own data from the assessment of MRI scans in healthy young females and data extracted from four studies that assessed uterine volume using transabdominal ultrasound in healthy females we have derived and validated a normative <span class="hlt">model</span> of uterine volume from birth to <span class="hlt">age</span> 40 years. This shows that uterine volume increases across childhood, with a faster increase in adolescence reflecting the influence of puberty, followed by a slow but progressive rise during adult life. The <span class="hlt">model</span> suggests that around 84% of the variation in uterine volumes in the healthy population up to <span class="hlt">age</span> 40 is due to <span class="hlt">age</span> alone. The derivation of a validated normative <span class="hlt">model</span> for uterine volume from birth to <span class="hlt">age</span> 40 years has important clinical applications by providing <span class="hlt">age</span>-related reference values for uterine volume. PMID:27295032</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.......118G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.......118G"><span id="translatedtitle">Experimental characterization and <span class="hlt">modeling</span> of isothermal and nonisothermal physical <span class="hlt">aging</span> in glassy polymer films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Yunlong</p> <p></p> <p>This dissertation focuses on nonisothermal physical <span class="hlt">aging</span> of polymers from both experimental and theoretical aspects. The study concentrates on pure polymers rather than fiber-reinforced composites; this step removes several complicating factors to simplify the study. It is anticipated that the findings of this work can then be applied to composite materials applications. The physical <span class="hlt">aging</span> tests in this work are performed using a dynamic mechanical analyzer (DMA). The viscoelastic response of glassy polymers under various loading and thermal histories are observed as stress-strain data at a series of time points. The first stage of the experimental work involves the characterization of the isothermal physical <span class="hlt">aging</span> behavior of two advanced thermoplastics. The second stage conducts tests on the same materials with varying thermal histories and with long-term test duration. This forms the basis to assess and modify a nonisothermal physical <span class="hlt">aging</span> <span class="hlt">model</span> (KAHR-ate <span class="hlt">model</span>). Based on the experimental findings, the KAHR-ate <span class="hlt">model</span> has been revised by new correlations between <span class="hlt">aging</span> shift factors and volume response; this revised <span class="hlt">model</span> performed well in predicting the nonisothermal physical <span class="hlt">aging</span> behavior of glassy polymers. In the work on isothermal physical <span class="hlt">aging</span>, short-term creep and stress relaxation tests were performed at several temperatures within 15-35°C below the glass transition temperature (Tg) at various <span class="hlt">aging</span> times, using the short-term test method established by Struik. Stress and strain levels were such that the materials remained in the linear viscoelastic regime. These curves were then shifted together to determine momentary master curves and shift rates. In order to validate the obtained isothermal physical <span class="hlt">aging</span> behavior, the results of creep and stress relaxation testing were compared and shown to be consistent with one another using appropriate interconversion of the viscoelastic material functions. Time-temperature superposition of the master curves</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPC.1367...29A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPC.1367...29A"><span id="translatedtitle">Precise Measurement of the <span class="hlt">Absolute</span> Fluorescence Yield</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ave, M.; Bohacova, M.; Daumiller, K.; Di Carlo, P.; di Giulio, C.; San Luis, P. Facal; Gonzales, D.; Hojvat, C.; Hörandel, J. R.; Hrabovsky, M.; Iarlori, M.; Keilhauer, B.; Klages, H.; Kleifges, M.; Kuehn, F.; Monasor, M.; Nozka, L.; Palatka, M.; Petrera, S.; Privitera, P.; Ridky, J.; Rizi, V.; D'Orfeuil, B. Rouille; Salamida, F.; Schovanek, P.; Smida, R.; Spinka, H.; Ulrich, A.; Verzi, V.; Williams, C.</p> <p>2011-09-01</p> <p>We present preliminary results of the <span class="hlt">absolute</span> yield of fluorescence emission in atmospheric gases. Measurements were performed at the Fermilab Test Beam Facility with a variety of beam particles and gases. <span class="hlt">Absolute</span> calibration of the fluorescence yield to 5% level was achieved by comparison with two known light sources--the Cherenkov light emitted by the beam particles, and a calibrated nitrogen laser. The uncertainty of the energy scale of current Ultra-High Energy Cosmic Rays experiments will be significantly improved by the AIRFLY measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24615881','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24615881"><span id="translatedtitle">Structured additive regression <span class="hlt">modeling</span> of <span class="hlt">age</span> of menarche and menopause in a breast cancer screening program.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duarte, Elisa; de Sousa, Bruno; Cadarso-Suarez, Carmen; Rodrigues, Vitor; Kneib, Thomas</p> <p>2014-05-01</p> <p>Breast cancer risk is believed to be associated with several reproductive factors, such as early menarche and late menopause. This study is based on the registries of the first time a woman enters the screening program, and presents a spatio-temporal analysis of the variables <span class="hlt">age</span> of menarche and <span class="hlt">age</span> of menopause along with other reproductive and socioeconomic factors. The database was provided by the Portuguese Cancer League (LPCC), a private nonprofit organization dealing with multiple issues related to oncology of which the Breast Cancer Screening Program is one of its main activities. The registry consists of 259,652 records of women who entered the screening program for the first time between 1990 and 2007 (45-69-year <span class="hlt">age</span> group). Structured Additive Regression (STAR) <span class="hlt">models</span> were used to explore spatial and temporal correlations with a wide range of covariates. These <span class="hlt">models</span> are flexible enough to deal with a variety of complex datasets, allowing us to reveal possible relationships among the variables considered in this study. The analysis shows that early menarche occurs in younger women and in municipalities located in the interior of central Portugal. Women living in inland municipalities register later <span class="hlt">ages</span> for menopause, and those born in central Portugal after 1933 show a decreasing trend in the <span class="hlt">age</span> of menopause. Younger <span class="hlt">ages</span> of menarche and late menopause are observed in municipalities with a higher purchasing power index. The analysis performed in this study portrays the time evolution of the <span class="hlt">age</span> of menarche and <span class="hlt">age</span> of menopause and their spatial characterization, adding to the identification of factors that could be of the utmost importance in future breast cancer incidence research. PMID:24615881</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012EGUGA..14.3080M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012EGUGA..14.3080M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Absolute</span> GNSS Antenna Calibration at the National Geodetic Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mader, G.; Bilich, A.; Geoghegan, C.</p> <p>2012-04-01</p> <p>Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna <span class="hlt">models</span> and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these <span class="hlt">models</span> into analysis software. To help meet the needs of the high-precision GNSS community, the National Geodetic Survey (NGS) now operates an <span class="hlt">absolute</span> antenna calibration facility. Located in Corbin, Virginia, this facility uses field measurements and actual GNSS satellite signals to quantitatively determine the carrier phase advance/delay introduced by the antenna element. The NGS facility was built to serve traditional NGS constituents such as the surveying and geodesy communities, however calibration services are open and available to all GNSS users as the calibration schedule permits. All phase center patterns computed by this facility will be publicly available and disseminated in both the ANTEX and NGS formats. We describe the NGS calibration facility, and discuss the observation <span class="hlt">models</span> and strategy currently used to generate NGS <span class="hlt">absolute</span> calibrations. We demonstrate that NGS <span class="hlt">absolute</span> phase center variation (PCV) patterns are consistent with published values determined by other <span class="hlt">absolute</span> antenna calibration facilities, and outline future planned refinements to the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999EPJB....9..365S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999EPJB....9..365S"><span id="translatedtitle">The Penna <span class="hlt">model</span> for biological <span class="hlt">ageing</span> on a lattice: spatial consequences of child-care</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sousa, A. O.; Moss de Oliveira, S.</p> <p></p> <p>We introduce a square lattice into the Penna bit-string <span class="hlt">model</span> for biological <span class="hlt">ageing</span> and study the evolution of the spatial distribution of the population considering different strategies of child-care. Two of the strategies are related to the movements of a whole family on the lattice: in one case the mother cannot move if she has any child younger than a given <span class="hlt">age</span>, and in the other case if she moves, she brings these young children with her. A stronger condition has also been added to the second case, considering that young children die with a higher probability if their mothers die, this probability decreasing with <span class="hlt">age</span>. We show that a highly non uniform occupation can be obtained when child-care is considered, even for an uniform initial occupation per site. We also compare the standard survival rate of the <span class="hlt">model</span> with that obtained when the spacial lattice is considered (without any kind of child-care).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991A%26A...245...57M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991A%26A...245...57M"><span id="translatedtitle">The <span class="hlt">age</span>-metallicity-velocity dispersion relation in the solar neighborhood and a simple evolution <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meusinger, H.; Stecklum, B.; Reimann, H.-G.</p> <p>1991-05-01</p> <p>An analysis of the <span class="hlt">age</span>-metallicity relation (AMR) based on previous data is conducted again and the <span class="hlt">age</span>-velocity relation (AVR) is estimated for some nearby stars to examine connections between the relations. In the period of evolution of the galactic disk, an important relationship with <span class="hlt">age</span> is determined for both AMR and AVR. The observed metallicity-velocity relation is compared to the predicted relation to verify the AVR and AMR derivations. A <span class="hlt">model</span> is presented in which the star formation rate, the infall rate of gas, and the initial mass function are constant. The <span class="hlt">model</span> is found to agree with observed constraints on star counts in the solar neighborhood and constraints on the chemical and kinematical evolution of the local disk. A theory regarding the primary heating mechanism of the galactic disk is developed in terms of the AVR, and possible explanations - massive gas clouds and transient spiral waves - are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JPhCS.705a2029A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JPhCS.705a2029A&link_type=ABSTRACT"><span id="translatedtitle">Arterial pulse pressure amplification described by means of a nonlinear wave <span class="hlt">model</span>: characterization of human <span class="hlt">aging</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alfonso, M.; Cymberknop, L.; Armentano, R.; Pessana, F.; Wray, S.; Legnani, W.</p> <p>2016-04-01</p> <p>The representation of blood pressure pulse as a combination of solitons captures many of the phenomena observed during its propagation along the systemic circulation. The aim of this work is to analyze the applicability of a compartmental <span class="hlt">model</span> for propagation regarding the pressure pulse amplification associated with arterial <span class="hlt">aging</span>. The <span class="hlt">model</span> was applied to blood pressure waveforms that were synthesized using solitons, and then validated by waveforms obtained from individuals from differentiated <span class="hlt">age</span> groups. Morphological changes were verified in the blood pressure waveform as a consequence of the <span class="hlt">aging</span> process (i.e. due to the increase in arterial stiffness). These changes are the result of both a nonlinear interaction and the phenomena present in the propagation of nonlinear mechanic waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2855888','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2855888"><span id="translatedtitle"><span class="hlt">Age</span> at First Birth and Fathers' Subsequent Health: Evidence From Sibling and Twin <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pudrovska, Tetyana; Carr, Deborah</p> <p>2010-01-01</p> <p>Using a sample of 540 siblings and twins from the National Survey of Midlife Development in the United States, this study examines the relationship between the <span class="hlt">age</span> at which men become biological fathers and their subsequent health. The analysis includes both between-family <span class="hlt">models</span> that treat brothers as independent observations and within-family <span class="hlt">models</span> that account for unobserved genetic and early-life environmental endowments shared by brothers within families. Findings indicate that <span class="hlt">age</span> at first birth has a positive, linear effect on men's health, and this relationship is not explained by the confounding influences of unobserved early-life characteristics. However, the effect of <span class="hlt">age</span> at first birth on fathers' health is explained by men's socioeconomic and family statuses. Whereas most research linking birth timing to specific diseases focuses narrowly on biological mechanisms among mothers, this study demonstrates the importance of reproductive decisions for men's health and well-being. PMID:19477723</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3126862','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3126862"><span id="translatedtitle">Neuroscientists as Cartographers: Mapping the Crossroads of Gonadal Hormones, Memory and <span class="hlt">Age</span> Using Animal <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bimonte-Nelson, Heather A.; Acosta, Jazmin I.; Talboom, Joshua S.</p> <p>2010-01-01</p> <p>Cognitive function is multidimensional and complex, and research in multiple species indicates it is considerably impacted by <span class="hlt">age</span> and gonadal hormone milieu. One domain of cognitive function particularly susceptible to <span class="hlt">age</span>-related decrements is spatial memory. Gonadal hormones can alter spatial memory, and they are potent modulators of brain microstructure and function in many of the same brain areas affected by <span class="hlt">aging</span>. In this paper, we review decades of animal and human literature to support a tertiary <span class="hlt">model</span> representing interactions between gonadal hormones, spatial cognition and <span class="hlt">age</span> given that: 1) gonadal hormones change with <span class="hlt">age</span>, 2) <span class="hlt">age</span> impacts spatial learning and memory, and 3) gonadal hormones impact spatial learning and memory. While much has been discovered regarding these individual tenets, the compass for future <span class="hlt">aging</span> research points toward clarifying the interactions that exist between these three points, and understanding mediating variables. Indeed, identifying and aligning the various components of the complex interactions between these tenets, including evaluations using basic science, systems, and clinical perspectives, is the optimal approach to attempt to converge the many findings that may currently appear contradictory. In fact, as discoveries are being made it is becoming clear that the findings across studies that appear contradictory are not contradictory at all. Rather, there are mediating variables that are influencing outcome and affecting the extent, and even the direction, of the effects that gonadal hormones have on cognition during <span class="hlt">aging</span>. These mediating variables are just starting to be understood. By aligning basic scientific discoveries with clinical interpretations, we can maximize the opportunities for discoveries and subsequent interventions to allow individuals to “optimize their aging” and find their own map to cognitive health as <span class="hlt">aging</span> ensues. PMID:20877209</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3272099','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3272099"><span id="translatedtitle">The hierarchical factor <span class="hlt">model</span> of ADHD: Invariant across <span class="hlt">age</span> and national groupings?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Toplak, Maggie E.; Sorge, Geoff B.; Flora, David B.; Chen, Wai; Banaschewski, Tobias; Buitelaar, Jan; Ebstein, Richard; Eisenberg, Jacques; Franke, Barbara; Gill, Michael; Miranda, Ana; Oades, Robert D.; Roeyers, Herbert; Rothenberger, Aribert; Sergeant, Joseph; Sonuga-Barke, Edmund; Steinhausen, Hans-Christoph; Thompson, Margaret; Tannock, Rosemary; Asherson, Philip; Faraone, Stephen V.</p> <p>2011-01-01</p> <p>Objective To examine the factor structure of Attention-Deficit/Hyperactivity Disorder (ADHD) in a clinical sample of 1373 children and adolescents with ADHD and their 1772 unselected siblings recruited from different countries across a large <span class="hlt">age</span> range. Hierarchical and correlated factor analytic <span class="hlt">models</span> were compared separately in the ADHD and sibling samples, across three different instruments and across parent and teacher informants. Specific consideration was given to factorial invariance analyses across different <span class="hlt">ages</span> and different countries in the ADHD sample. Method A sample of children and adolescents between 5 and 17 years of <span class="hlt">age</span> with ADHD and their unselected siblings was assessed. Participants were recruited from seven European countries and Israel. ADHD symptom data came from a clinical interview with parents (PACS) and questionnaires from parents and teachers (Conners Parent and Teacher). Results A hierarchical general factor <span class="hlt">model</span> with two specific factors best represented the structure of ADHD in both the ADHD and unselected sibling groups, and across informants and instruments. The <span class="hlt">model</span> was robust and invariant with regard to <span class="hlt">age</span> differences in the ADHD sample. The <span class="hlt">model</span> was not strongly invariant across different national groups in the ADHD sample, likely reflecting severity differences across the different centers and not any substantial difference in the clinical presentation of ADHD. Conclusions The results replicate previous studies of a <span class="hlt">model</span> with a unitary ADHD component and separable specific traits of inattention and hyperactivity/impulsivity. The unique contribution of this study was finding support for this <span class="hlt">model</span> across a large developmental and multinational/multicultural sample and its invariance across <span class="hlt">ages</span>. PMID:22084976</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002Tectp.358...17A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002Tectp.358...17A"><span id="translatedtitle">Seismic tomography of continental rifts revisited: from relative to <span class="hlt">absolute</span> heterogeneities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Achauer, Ulrich; Masson, Frédéric</p> <p>2002-11-01</p> <p>Tomographic images for four major continental rift zones, namely the southern Rhine Graben (SRG, Germany/France), the Gregory rift (Kenya) which is the central part of the East African rift system, the Rio Grande rift (RGR) in the United States and the Lake Baikal rift zone (LBR) in Russia have been revisited by calculating and comparing <span class="hlt">absolute</span> velocity <span class="hlt">models</span>. The four rifts exhibit strong structural differences in the uppermost mantle down to more than 300-km depth, suggesting major differences in their geodynamic evolution albeit their similarity in <span class="hlt">age</span> and similar surface expression. The comparative analysis suggests that tomographic images of rift zones can be used to characterize continental rifts, once the corrections to obtain <span class="hlt">absolute</span> velocities have been carried out. Our results suggest that while the Kenya and the Rio Grande rift may be considered active with large upwelling plumes being the main controlling factor in the evolution, the southern Rhine Graben and the Lake Baikal rift are more likely passive rifts, where complex regional stress fields and inherited structures play the governing role in the evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1235324-compact-modeling-total-ionizing-dose-aging-effects-mos-technologies','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1235324-compact-modeling-total-ionizing-dose-aging-effects-mos-technologies"><span id="translatedtitle">Compact <span class="hlt">modeling</span> of total ionizing dose and <span class="hlt">aging</span> effects in MOS technologies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Esqueda, Ivan S.; Barnaby, Hugh J.; King, Michael Patrick</p> <p>2015-06-18</p> <p>This paper presents a physics-based compact <span class="hlt">modeling</span> approach that incorporates the impact of total ionizing dose (TID) and stress-induced defects into simulations of metal-oxide-semiconductor (MOS) devices and integrated circuits (ICs). This approach utilizes calculations of surface potential (ψs) to capture the charge contribution from oxide trapped charge and interface traps and to describe their impact on MOS electrostatics and device operating characteristics as a function of ionizing radiation exposure and <span class="hlt">aging</span> effects. The <span class="hlt">modeling</span> approach is demonstrated for bulk and silicon-on-insulator (SOI) MOS device. The formulation is verified using TCAD simulations and through the comparison of <span class="hlt">model</span> calculations and experimentalmore » I-V characteristics from irradiated devices. The presented approach is suitable for <span class="hlt">modeling</span> TID and <span class="hlt">aging</span> effects in advanced MOS devices and ICs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1235324','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1235324"><span id="translatedtitle">Compact <span class="hlt">modeling</span> of total ionizing dose and <span class="hlt">aging</span> effects in MOS technologies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Esqueda, Ivan S.; Barnaby, Hugh J.; King, Michael Patrick</p> <p>2015-06-18</p> <p>This paper presents a physics-based compact <span class="hlt">modeling</span> approach that incorporates the impact of total ionizing dose (TID) and stress-induced defects into simulations of metal-oxide-semiconductor (MOS) devices and integrated circuits (ICs). This approach utilizes calculations of surface potential (ψs) to capture the charge contribution from oxide trapped charge and interface traps and to describe their impact on MOS electrostatics and device operating characteristics as a function of ionizing radiation exposure and <span class="hlt">aging</span> effects. The <span class="hlt">modeling</span> approach is demonstrated for bulk and silicon-on-insulator (SOI) MOS device. The formulation is verified using TCAD simulations and through the comparison of <span class="hlt">model</span> calculations and experimental I-V characteristics from irradiated devices. The presented approach is suitable for <span class="hlt">modeling</span> TID and <span class="hlt">aging</span> effects in advanced MOS devices and ICs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21526601','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21526601"><span id="translatedtitle">Relative and <span class="hlt">absolute</span> stability in perceived parenting behaviour: a longitudinal study with children and adolescents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carrasco, M A; Rodríguez, M A; Del Barrio, M V; Holgado, F P</p> <p>2011-02-01</p> <p>Patterns of relative and <span class="hlt">absolute</span> stability in parental behaviour with children and adolescents are reported. The sample comprised 523 youth (58.7% girls). Data were collected at three time periods: T1 (M <span class="hlt">age</span> = 11.1 yr.), T2 (M <span class="hlt">age</span> = 12.2 yr.), and T3 (M <span class="hlt">age</span> = 13.2 yr.), each separated by one year. According to children's reports, relative consistency was moderate in both mothers and fathers, particularly as regards communication and strict control. In contrast, as children got older, parental rearing practices related to strict control and hostility decreased. There was a similarity between fathers and mothers in terms of relative and <span class="hlt">absolute</span> stability. Relative stability was affected by the child's sex, the parenting variable, and the time period; however, the patterns of <span class="hlt">absolute</span> stability reveal no differences by sex. PMID:21526601</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22561301','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22561301"><span id="translatedtitle">Increasing pulse wave velocity in a realistic cardiovascular <span class="hlt">model</span> does not increase pulse pressure with <span class="hlt">age</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mohiuddin, Mohammad W; Rihani, Ryan J; Laine, Glen A; Quick, Christopher M</p> <p>2012-07-01</p> <p>The mechanism of the well-documented increase in aortic pulse pressure (PP) with <span class="hlt">age</span> is disputed. Investigators assuming a classical windkessel <span class="hlt">model</span> believe that increases in PP arise from decreases in total arterial compliance (C(tot)) and increases in total peripheral resistance (R(tot)) with <span class="hlt">age</span>. Investigators assuming a more sophisticated pulse transmission <span class="hlt">model</span> believe PP rises because increases in pulse wave velocity (c(ph)) make the reflected pressure wave arrive earlier, augmenting systolic pressure. It has recently been shown, however, that increases in c(ph) do not have a commensurate effect on the timing of the reflected wave. We therefore used a validated, large-scale, human arterial system <span class="hlt">model</span> that includes realistic pulse wave transmission to determine whether increases in c(ph) cause increased PP with <span class="hlt">age</span>. First, we made the realistic arterial system <span class="hlt">model</span> <span class="hlt">age</span> dependent by altering cardiac output (CO), R(tot), C(tot), and c(ph) to mimic the reported changes in these parameters from <span class="hlt">age</span> 30 to 70. Then, c(ph) was theoretically maintained constant, while C(tot), R(tot), and CO were altered. The predicted increase in PP with <span class="hlt">age</span> was similar to the observed increase in PP. In a complementary approach, C(tot), R(tot), and CO were theoretically maintained constant, and c(ph) was increased. The predicted increase in PP was negligible. We found that increases in c(ph) have a limited effect on the timing of the reflected wave but cause the system to degenerate into a windkessel. Changes in PP can therefore be attributed to a decrease in C(tot). PMID:22561301</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGP43D..04A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGP43D..04A"><span id="translatedtitle">Cyclostratigraphy for Chinese red clay sequences: Implications to changing previous <span class="hlt">age</span> <span class="hlt">models</span> and paleoclimate interpretations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anwar, T.; Kravchinsky, V. A.; Zhang, R.</p> <p>2015-12-01</p> <p>The Chinese Loess Plateau contains red clay sequence which has continuous alternation of sedimentary cycles with recurrent paleoclimatic fluctuations. Absence of abundant fossils and inability of radiometric dating method made magnetostratigraphy a leading method to build <span class="hlt">age</span> <span class="hlt">model</span> for the red clay. Here magnetostratigraphic <span class="hlt">age</span> <span class="hlt">model</span> in red clay sequence is tested using cyclostratigraphy as orbital parameters of Earth are known. Milankovitch periodicities recorded in magnetic susceptibility and grain size in the Shilou red clay section are investigated and previously found <span class="hlt">age</span> of 11 Ma for this section is re-evaluated. Magnetostratigraphy dating based on only visual correlation could potentially lead to erroneous <span class="hlt">age</span> <span class="hlt">model</span>. In this study the correlation is executed through the iteration procedure until it is supported by cyclostratigraphy; i.e. Milankovitch cycles are resolved in the best possible manner. Our new approach provides an <span class="hlt">age</span> of 5.2 Ma for the Shilou profile. Wavelet analysis reveals that a 400 kyr eccentricity cycle is well preserved and the existence of a 100 kyr eccentricity in the red clay sequence on the eastern Chinese Loess Plateau suggests that eccentricity plays a vital role in Pliocene climate evolution. Paleomonsoon evolution is reconstructed and divided into three intervals (5.2-4.5 Ma, 4.5-3.6 Ma and 3.6-2.58 Ma). The earliest stage indicates that summer and winter monsoon cycles may rapidly alter, whereas the middle stage reflects an intensification of winter monsoon and aridification in Asia, and the youngest stage is characterized by relatively intensified summer monsoon. This study demonstrates that cyclostratigraphy can greatly assist magnetostratigraphy in dating the red clay sequences, and implies that many published <span class="hlt">age</span> <span class="hlt">models</span> for the red clay sequences should likely be re-assessed where possible. An evaluation of the monsoon system and climate change in eastern Asia might prominently benefit from this approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4298821','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4298821"><span id="translatedtitle">Effects of Exendin-4 on Male Reproductive Parameters of D-Galactose Induced <span class="hlt">Aging</span> Mouse <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ahangarpour, Akram; Heidari, Hamid</p> <p>2014-01-01</p> <p>Purpose The purpose of this study was to evaluate the role of exendin-4 on reproductive alteration in a D-galactose-induced <span class="hlt">aging</span> mouse <span class="hlt">model</span>. Materials and Methods In this experimental study, 72 male Naval Medical Research Institute mice (20~25 g) were randomly divided into six groups: control, exendin-4 (1 nmol/kg), exendin-4 (10 nmol/kg), D-galactose (500 mg/kg), D-galactose+exendin-4 (1 nmol/kg), and D-galactose+exendin-4 (10 nmol/kg). The <span class="hlt">aging</span> <span class="hlt">model</span> animals were gavaged with D-galactose for six weeks, and exendin-4 was injected intraperitoneally in the last 10 days. At the end of treatment serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone levels were evaluated and the cauda epididymis and testis were removed to analyze the sperm count and testis morphology. Results The testis weight and volume decreased in the D-galactose group (p<0.01 and p<0.05) respectively. Exendin-4 (1, 10 nmol/kg) increased these parameters in the normal and <span class="hlt">aging</span> mouse <span class="hlt">models</span>. Serum LH and FSH levels increased and the sperm count decreased in the D-galactose group (p<0.05). Further, exendin-4 (1 nmol/kg) decreased LH and FSH levels and increased the serum testosterone level and sperm count in both normal and <span class="hlt">aging</span> animals. Conclusions D-galactose can induce <span class="hlt">aging</span> alternations in the male reproductive system such as decreased sperm count and increased serum LH and FSH levels through reactive oxygen species over production and reduced antioxidant enzyme activity. Further, co-administration of exendin-4 reduced reproductive complications of D-galactose in an <span class="hlt">aging</span> mouse <span class="hlt">model</span>. PMID:25606567</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4975122','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4975122"><span id="translatedtitle"><span class="hlt">Model</span> Fitting Versus Curve Fitting: A <span class="hlt">Model</span> of Renormalization Provides a Better Account of <span class="hlt">Age</span> Aftereffects Than a <span class="hlt">Model</span> of Local Repulsion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mac, Amy; Rhodes, Gillian; Webster, Michael A.</p> <p>2015-01-01</p> <p>Recently, we proposed that the aftereffects of adapting to facial <span class="hlt">age</span> are consistent with a renormalization of the perceived <span class="hlt">age</span> (e.g., so that after adapting to a younger or older <span class="hlt">age</span>, all <span class="hlt">ages</span> appear slightly older or younger, respectively). This conclusion has been challenged by arguing that the aftereffects can also be accounted for by an alternative <span class="hlt">model</span> based on repulsion (in which facial <span class="hlt">ages</span> above or below the adapting <span class="hlt">age</span> are biased away from the adaptor). However, we show here that this challenge was based on allowing the fitted functions to take on values which are implausible and incompatible across the different adapting conditions. When the fits are constrained or interpreted in terms of standard assumptions about normalization and repulsion, then the two analyses both agree in pointing to a pattern of renormalization in <span class="hlt">age</span> aftereffects. PMID:27551353</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED117048.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED117048.pdf"><span id="translatedtitle">Improvement, Supervision, and Dissemination of a <span class="hlt">Model</span> Cross-<span class="hlt">Age</span> Tutoring Program.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Breedlove, Donnie L.</p> <p></p> <p>This practicum was developed (1) to improve, supervise, and disseminate a <span class="hlt">model</span> cross-<span class="hlt">age</span> tutoring program, and (2) to determine if a tutorial program would increase the sight vocabulary of 100 second grade students in the Dallas Independent School District. A secondary purpose was to determine if such a program would improve the reading grades,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=separate%7e&pg=5&id=EJ955240','ERIC'); return false;" href="http://eric.ed.gov/?q=separate%7e&pg=5&id=EJ955240"><span id="translatedtitle">The Hierarchical Factor <span class="hlt">Model</span> of ADHD: Invariant across <span class="hlt">Age</span> and National Groupings?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Toplak, Maggie E.; Sorge, Geoff B.; Flora, David B.; Chen, Wai; Banaschewski, Tobias; Buitelaar, Jan; Ebstein, Richard; Eisenberg, Jacques; Franke, Barbara; Gill, Michael; Miranda, Ana; Oades, Robert D.; Roeyers, Herbert; Rothenberger, Aribert; Sergeant, Joseph; Sonuga-Barke, Edmund; Steinhausen, Hans-Christoph; Thompson, Margaret; Tannock, Rosemary; Asherson, Philip; Faraone, Stephen V.</p> <p>2012-01-01</p> <p>Objective: To examine the factor structure of attention-deficit/hyperactivity disorder (ADHD) in a clinical sample of 1,373 children and adolescents with ADHD and their 1,772 unselected siblings recruited from different countries across a large <span class="hlt">age</span> range. Hierarchical and correlated factor analytic <span class="hlt">models</span> were compared separately in the ADHD and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4932605','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4932605"><span id="translatedtitle">The reemergence of long-term potentiation in <span class="hlt">aged</span> Alzheimer’s disease mouse <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Huh, Seonghoo; Baek, Soo-Ji; Lee, Kyung-Hwa; Whitcomb, Daniel J.; Jo, Jihoon; Choi, Seong-Min; Kim, Dong Hyun; Park, Man-Seok; Lee, Kun Ho; Kim, Byeong C.</p> <p>2016-01-01</p> <p>Mouse <span class="hlt">models</span> of Alzheimer’s disease (AD) have been developed to study the pathophysiology of amyloid β protein (Aβ) toxicity, which is thought to cause severe clinical symptoms such as memory impairment in AD patients. However, inconsistencies exist between studies using these animal <span class="hlt">models</span>, specifically in terms of the effects on synaptic plasticity, a major cellular <span class="hlt">model</span> of learning and memory. Whereas some studies find impairments in plasticity in these <span class="hlt">models</span>, others do not. We show that long-term potentiation (LTP), in the CA1 region of hippocampal slices from this mouse, is impared at Tg2576 adult 6–7 months old. However, LTP is inducible again in slices taken from Tg2576 <span class="hlt">aged</span> 14–19 months old. In the <span class="hlt">aged</span> Tg2576, we found that the percentage of parvalbumin (PV)-expressing interneurons in hippocampal CA1-3 region is significantly decreased, and LTP inhibition or reversal mediated by NRG1/ErbB signaling, which requires ErbB4 receptors in PV interneurons, is impaired. Inhibition of ErbB receptor kinase in adult Tg2576 restores LTP but impairs depotentiation as shown in <span class="hlt">aged</span> Tg2576. Our study suggests that hippocampal LTP reemerges in <span class="hlt">aged</span> Tg2576. However, this reemerged LTP is an insuppressible form due to impaired NRG1/ErbB signaling, possibly through the loss of PV interneurons. PMID:27377368</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27377368','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27377368"><span id="translatedtitle">The reemergence of long-term potentiation in <span class="hlt">aged</span> Alzheimer's disease mouse <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huh, Seonghoo; Baek, Soo-Ji; Lee, Kyung-Hwa; Whitcomb, Daniel J; Jo, Jihoon; Choi, Seong-Min; Kim, Dong Hyun; Park, Man-Seok; Lee, Kun Ho; Kim, Byeong C</p> <p>2016-01-01</p> <p>Mouse <span class="hlt">models</span> of Alzheimer's disease (AD) have been developed to study the pathophysiology of amyloid β protein (Aβ) toxicity, which is thought to cause severe clinical symptoms such as memory impairment in AD patients. However, inconsistencies exist between studies using these animal <span class="hlt">models</span>, specifically in terms of the effects on synaptic plasticity, a major cellular <span class="hlt">model</span> of learning and memory. Whereas some studies find impairments in plasticity in these <span class="hlt">models</span>, others do not. We show that long-term potentiation (LTP), in the CA1 region of hippocampal slices from this mouse, is impared at Tg2576 adult 6-7 months old. However, LTP is inducible again in slices taken from Tg2576 <span class="hlt">aged</span> 14-19 months old. In the <span class="hlt">aged</span> Tg2576, we found that the percentage of parvalbumin (PV)-expressing interneurons in hippocampal CA1-3 region is significantly decreased, and LTP inhibition or reversal mediated by NRG1/ErbB signaling, which requires ErbB4 receptors in PV interneurons, is impaired. Inhibition of ErbB receptor kinase in adult Tg2576 restores LTP but impairs depotentiation as shown in <span class="hlt">aged</span> Tg2576. Our study suggests that hippocampal LTP reemerges in <span class="hlt">aged</span> Tg2576. However, this reemerged LTP is an insuppressible form due to impaired NRG1/ErbB signaling, possibly through the loss of PV interneurons. PMID:27377368</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=design+AND+village&id=EJ965017','ERIC'); return false;" href="http://eric.ed.gov/?q=design+AND+village&id=EJ965017"><span id="translatedtitle">The "Village" <span class="hlt">Model</span>: A Consumer-Driven Approach for <span class="hlt">Aging</span> in Place</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Scharlach, Andrew; Graham, Carrie; Lehning, Amanda</p> <p>2012-01-01</p> <p>Purpose of the Study: This study examines the characteristics of the "Village" <span class="hlt">model</span>, an innovative consumer-driven approach that aims to promote <span class="hlt">aging</span> in place through a combination of member supports, service referrals, and consumer engagement. Design and Methods: Thirty of 42 fully operational Villages completed 2 surveys. 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