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Sample records for age distribution similar

  1. Bilateral Trade Flows and Income Distribution Similarity

    PubMed Central

    2016-01-01

    Current models of bilateral trade neglect the effects of income distribution. This paper addresses the issue by accounting for non-homothetic consumer preferences and hence investigating the role of income distribution in the context of the gravity model of trade. A theoretically justified gravity model is estimated for disaggregated trade data (Dollar volume is used as dependent variable) using a sample of 104 exporters and 108 importers for 1980–2003 to achieve two main goals. We define and calculate new measures of income distribution similarity and empirically confirm that greater similarity of income distribution between countries implies more trade. Using distribution-based measures as a proxy for demand similarities in gravity models, we find consistent and robust support for the hypothesis that countries with more similar income-distributions trade more with each other. The hypothesis is also confirmed at disaggregated level for differentiated product categories. PMID:27137462

  2. On distributional assumptions and whitened cosine similarities.

    PubMed

    Loog, Marco

    2008-06-01

    Recently, an interpretation of the whitened cosine similarity measure as a Bayes decision rule was proposed (C. Liu, "The Bayes Decision Rule Induced Similarity Measures,'' IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 29, no. 6, pp. 1086-1090, June 2007. This communication makes the observation that some of the distributional assumptions made to derive this measure are very restrictive and, considered simultaneously, even inconsistent.

  3. Age Distribution of Groundwater

    NASA Astrophysics Data System (ADS)

    Morgenstern, U.; Daughney, C. J.

    2012-04-01

    Groundwater at the discharge point comprises a mixture of water from different flow lines with different travel time and therefore has no discrete age but an age distribution. The age distribution can be assessed by measuring how a pulse shaped tracer moves through the groundwater system. Detection of the time delay and the dispersion of the peak in the groundwater compared to the tracer input reveals the mean residence time and the mixing parameter. Tritium from nuclear weapons testing in the early 1960s resulted in a peak-shaped tritium input to the whole hydrologic system on earth. Tritium is the ideal tracer for groundwater because it is an isotope of hydrogen and therefore is part of the water molecule. Tritium time series data that encompass the passage of the bomb tritium pulse through the groundwater system in all common hydrogeologic situations in New Zealand demonstrate a semi-systematic pattern between age distribution parameters and hydrologic situation. The data in general indicate high fraction of mixing, but in some cases also indicate high piston flow. We will show that still, 45 years after the peak of the bomb tritium, it is possible to assess accurately the parameters of age distributions by measuring the tail of the bomb tritium.

  4. Exploring similarities among many species distributions

    USGS Publications Warehouse

    Simmerman, Scott; Wang, Jingyuan; Osborne, James; Shook, Kimberly; Huang, Jian; Godsoe, William; Simons, Theodore R.

    2012-01-01

    Collecting species presence data and then building models to predict species distribution has been long practiced in the field of ecology for the purpose of improving our understanding of species relationships with each other and with the environment. Due to limitations of computing power as well as limited means of using modeling software on HPC facilities, past species distribution studies have been unable to fully explore diverse data sets. We build a system that can, for the first time to our knowledge, leverage HPC to support effective exploration of species similarities in distribution as well as their dependencies on common environmental conditions. Our system can also compute and reveal uncertainties in the modeling results enabling domain experts to make informed judgments about the data. Our work was motivated by and centered around data collection efforts within the Great Smoky Mountains National Park that date back to the 1940s. Our findings present new research opportunities in ecology and produce actionable field-work items for biodiversity management personnel to include in their planning of daily management activities.

  5. LMC clusters - Age calibration and age distribution revisited

    NASA Technical Reports Server (NTRS)

    Elson, Rebecca A.; Fall, S. Michael

    1988-01-01

    The empirical age relation for star clusters in the Large Magellanic Cloud presented by Elson and Fall (1985) are reexamined using ages based only on main-sequence turnoffs. The present sample includes 57 clusters, 24 of which have color-magnitude diagrams published since 1985. The new calibration is very similar to that found previously, and the scatter in the relation corresponds to uncertainties of about a factor of 2 in age. The age distribution derived from the new calibration does not differ significantly from that derived in earlier work. It is compared with age distributions estimated by other authors for different samples of clusters, and the results are discussed.

  6. Modeled ground water age distributions

    USGS Publications Warehouse

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  7. Modeled ground water age distributions.

    PubMed

    Woolfenden, Linda R; Ginn, Timothy R

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  8. The global age distribution of granitic pegmatites

    USGS Publications Warehouse

    McCauley, Andrew; Bradley, Dwight C.

    2014-01-01

    An updated global compilation of 377 new and previously published ages indicates that granitic pegmatites range in age from Mesoarchean to Neogene and have a semi-periodic age distribution. Undivided granitic pegmatites show twelve age maxima: 2913, 2687, 2501, 1853, 1379, 1174, 988, 525, 483, 391, 319, and 72 Ma. These peaks correspond broadly with various proxy records of supercontinent assembly, including the age distributions of granites, detrital zircon grains, and passive margins. Lithium-cesium-tantalum (LCT) pegmatites have a similar age distribution to the undivided granitic pegmatites, with maxima at 2638, 1800, 962, 529, 485, 371, 309, and 274 Ma. Lithium and Ta resources in LCT pegmatites are concentrated in the Archean and Phanerozoic. While there are some Li resources from the Proterozoic, the dominantly bimodal distribution of resources is particularly evident for Ta. This distribution is similar to that of orogenic gold deposits, and has been interpreted to reflect the preservation potential of the orogenic belts where these deposits are formed. Niobium-yttrium-fluorine (NYF) pegmatites show similar age distributions to LCT pegmatites, but with a strong maximum at ca. 1000 Ma.

  9. Exact Score Distribution Computation for Similarity Searches in Ontologies

    NASA Astrophysics Data System (ADS)

    Schulz, Marcel H.; Köhler, Sebastian; Bauer, Sebastian; Vingron, Martin; Robinson, Peter N.

    Semantic similarity searches in ontologies are an important component of many bioinformatic algorithms, e.g., protein function prediction with the Gene Ontology. In this paper we consider the exact computation of score distributions for similarity searches in ontologies, and introduce a simple null hypothesis which can be used to compute a P-value for the statistical significance of similarity scores. We concentrate on measures based on Resnik’s definition of ontological similarity. A new algorithm is proposed that collapses subgraphs of the ontology graph and thereby allows fast score distribution computation. The new algorithm is several orders of magnitude faster than the naive approach, as we demonstrate by computing score distributions for similarity searches in the Human Phenotype Ontology.

  10. Automatic search for maximum similarity between molecular electrostatic potential distributions

    NASA Astrophysics Data System (ADS)

    Manaut, Francesc; Sanz, Ferran; José, Jaume; Milesi, Massimo

    1991-08-01

    A new computer program has been developed to automatically obtain the relative position of two molecules in which the similarity between molecular electrostatic-potential distributions is greatest. These distributions are considered in a volume around the molecules, and the similarity is measured by the Spearman rank coefficient. The program has been tested using several pairs of molecules: water vs. water; phenylethylamine and phenylpropylamine vs. benzylamine; and methotrexate vs. dihydrofolic acid.

  11. Similarity between humans and foams in aging dynamics

    NASA Astrophysics Data System (ADS)

    Weon, Byung Mook; Stewart, Peter S.

    2014-03-01

    Foams are cellular networks between two immiscible phases. Foams are initially unstable and finally evolve toward a state of lower energy through sequential coalescences of bubbles. In physics, foams are model systems for materials that minimize surface energy. We study coalescence dynamics of clean foams using numerical simulations with a network model. Initial clean foams consist of equally pressurized bubbles and a low fraction of liquid films without stabilizing agents. Aging of clean foams occurs with time as bubbles rapidly coalesce by film rupture and finally evolve toward a new quasi-equilibrium state. Here we find that foam aging is analogous to biological aging: the death rate of bubbles increases exponentially with time, which is similar to the Gompertz mortality law for biological populations. The coalescence evolution of foams is self-similar regardless of initial conditions. The population change of bubbles is well described by a Boltzmann sigmoidal function, indicating that the foam aging is a phase transition phenomenon. This result suggests that foams can be useful model systems for giving insights into biological aging. Suwon 440-746, South Korea.

  12. Similarity estimators for irregular and age-uncertain time series

    NASA Astrophysics Data System (ADS)

    Rehfeld, K.; Kurths, J.

    2014-01-01

    Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many data sets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age-uncertain time series. We compare the Gaussian-kernel-based cross-correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case, coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

  13. Similarity estimators for irregular and age uncertain time series

    NASA Astrophysics Data System (ADS)

    Rehfeld, K.; Kurths, J.

    2013-09-01

    Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many datasets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age uncertain time series. We compare the Gaussian-kernel based cross correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

  14. Similarity of Symbol Frequency Distributions with Heavy Tails

    NASA Astrophysics Data System (ADS)

    Gerlach, Martin; Font-Clos, Francesc; Altmann, Eduardo G.

    2016-04-01

    Quantifying the similarity between symbolic sequences is a traditional problem in information theory which requires comparing the frequencies of symbols in different sequences. In numerous modern applications, ranging from DNA over music to texts, the distribution of symbol frequencies is characterized by heavy-tailed distributions (e.g., Zipf's law). The large number of low-frequency symbols in these distributions poses major difficulties to the estimation of the similarity between sequences; e.g., they hinder an accurate finite-size estimation of entropies. Here, we show analytically how the systematic (bias) and statistical (fluctuations) errors in these estimations depend on the sample size N and on the exponent γ of the heavy-tailed distribution. Our results are valid for the Shannon entropy (α =1 ), its corresponding similarity measures (e.g., the Jensen-Shanon divergence), and also for measures based on the generalized entropy of order α . For small α 's, including α =1 , the errors decay slower than the 1 /N decay observed in short-tailed distributions. For α larger than a critical value α*=1 +1 /γ ≤2 , the 1 /N decay is recovered. We show the practical significance of our results by quantifying the evolution of the English language over the last two centuries using a complete α spectrum of measures. We find that frequent words change more slowly than less frequent words and that α =2 provides the most robust measure to quantify language change.

  15. Distribution of similar earthquakes in aftershocks of inland earthquakes

    NASA Astrophysics Data System (ADS)

    Hayashi, M.; Hiramatsu, Y.; Aftershock Observations Of 2007 Noto Hanto, G.

    2010-12-01

    Frictional properties control the slip behavior on a fault surface such as seismic slip and aseismic slip. Asperity, as a seismic slip area, is characterized by a strong coupling in the interseismic period and large coseismic slip. On the other hand, steady slip or afterslip occurs in an aseismic slip area around the asperity. If an afterslip area includes small asperities, a repeating rupture of single asperity can generate similar earthquakes due to the stress accumulation caused by the afterslip. We here investigate a detail distribution of similar earthquakes in the aftershocks of the 2007 Noto Hanto earthquake (Mjma 6.9) and the 2000 Western Tottori earthquake (Mjma 7.3), inland large earthquakes in Japan. We use the data obtained by the group for the aftershock observations of the 2007 Noto Hanto Earthquake and by the group for the aftershock observations of the 2000 Western Tottori earthquake. First, we select pairs of aftershocks whose cross correlation coefficients in 10 s time window of band-pass filtered waveforms of 1~4 Hz are greater than 0.95 at more than 5 stations and divide those into groups by a link of the cross correlation coefficients. Second, we reexamine the arrival times of P and S waves and the maximum amplitude for earthquakes of each group and apply the double-difference method (Waldhouser and Ellsworth, 2000) to relocate them. As a result of the analysis, we find 24 groups of similar earthquakes in the aftershocks on the source fault of the 2007 Noto Hanto Earthquake and 86 groups of similar earthquakes in the aftershocks on the source fault of the 2000 Western Tottori Earthquake. Most of them are distributed around or outside the asperity of the main shock. Geodetic studies reported that postseismic deformation was detected for the both earthquakes (Sagiya et al., 2002; Hashimoto et al., 2008). The source area of similar earthquakes seems to correspond to the afterslip area. These features suggest that the similar earthquakes observed

  16. Similarity

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1990-01-01

    In this 'Project Mathematics! series, sponsored by the California Institute for Technology (CalTech), the mathematical concept of similarity is presented. he history of and real life applications are discussed using actual film footage and computer animation. Terms used and various concepts of size, shape, ratio, area, and volume are demonstrated. The similarity of polygons, solids, congruent triangles, internal ratios, perimeters, and line segments using the previous mentioned concepts are shown.

  17. Enhancer Responses to Similarly Distributed Antagonistic Gradients in Development

    PubMed Central

    Zinzen, Robert P; Papatsenko, Dmitri

    2007-01-01

    Formation of spatial gene expression patterns in development depends on transcriptional responses mediated by gene control regions, enhancers. Here, we explore possible responses of enhancers to overlapping gradients of antagonistic transcriptional regulators in the Drosophila embryo. Using quantitative models based on enhancer structure, we demonstrate how a pair of antagonistic transcription factor gradients with similar or even identical spatial distributions can lead to the formation of distinct gene expression domains along the embryo axes. The described mechanisms are sufficient to explain the formation of the anterior and the posterior knirps expression, the posterior hunchback expression domain, and the lateral stripes of rhomboid expression and of other ventral neurogenic ectodermal genes. The considered principles of interaction between antagonistic gradients at the enhancer level can also be applied to diverse developmental processes, such as domain specification in imaginal discs, or even eyespot pattern formation in the butterfly wing. PMID:17500585

  18. Age-related similarities and differences in monitoring spatial cognition.

    PubMed

    Ariel, Robert; Moffat, Scott D

    2017-03-31

    Spatial cognitive performance is impaired in later adulthood but it is unclear whether the metacognitive processes involved in monitoring spatial cognitive performance are also compromised. Inaccurate monitoring could affect whether people choose to engage in tasks that require spatial thinking and also the strategies they use in spatial domains such as navigation. The current experiment examined potential age differences in monitoring spatial cognitive performance in a variety of spatial domains including visual-spatial working memory, spatial orientation, spatial visualization, navigation, and place learning. Younger and older adults completed a 2D mental rotation test, 3D mental rotation test, paper folding test, spatial memory span test, two virtual navigation tasks, and a cognitive mapping test. Participants also made metacognitive judgments of performance (confidence judgments, judgments of learning, or navigation time estimates) on each trial for all spatial tasks. Preference for allocentric or egocentric navigation strategies was also measured. Overall, performance was poorer and confidence in performance was lower for older adults than younger adults. In most spatial domains, the absolute and relative accuracy of metacognitive judgments was equivalent for both age groups. However, age differences in monitoring accuracy (specifically relative accuracy) emerged in spatial tasks involving navigation. Confidence in navigating for a target location also mediated age differences in allocentric navigation strategy use. These findings suggest that with the possible exception of navigation monitoring, spatial cognition may be spared from age-related decline even though spatial cognition itself is impaired in older age.

  19. Spontaneous Object Recognition Memory in Aged Rats: Complexity versus Similarity

    ERIC Educational Resources Information Center

    Gamiz, Fernando; Gallo, Milagros

    2012-01-01

    Previous work on the effect of aging on spontaneous object recognition (SOR) memory tasks in rats has yielded controversial results. Although the results at long-retention intervals are consistent, conflicting results have been reported at shorter delays. We have assessed the potential relevance of the type of object used in the performance of…

  20. Engaging the aging workforce: the relationship between perceived age similarity, satisfaction with coworkers, and employee engagement.

    PubMed

    Avery, Derek R; McKay, Patrick F; Wilson, David C

    2007-11-01

    Business publications and the popular press have stressed the importance of creating conditions for meaningful employee expression in work roles, also known as engagement. Few empirical studies, however, have examined how individual or situational factors relate to engagement. Consequently, this study examines the interplay between employee age, perceived coworker age composition, and satisfaction with older (older than 55) and younger (younger than 40) coworkers on engagement using a sample of 901 individuals employed in the United Kingdom. Results indicated that satisfaction with one's coworkers related significantly to engagement. Moreover, perceived age similarity was associated with higher levels of engagement among older workers when they were highly satisfied with their coworkers over 55 and lower levels of engagement when they were not.

  1. Age Similarities in Recognizing Threat From Faces and Diagnostic Cues

    PubMed Central

    Zebrowitz, Leslie A.; Franklin, Robert G.; McCormick, Cheryl M.; Carré, Justin M.

    2014-01-01

    Background. Previous research indicates that younger adults (YA) can identify men’s tendency to be aggressive based merely on their neutral expression faces. We compared older adults (OA) and YA accuracy and investigated contributing facial cues. Method. In Study 1, YA and OA rated the aggressiveness of young men depicted in facial photographs in a control, distraction, or accuracy motivation condition. In Study 2, YA and OA rated how angry, attractive, masculine, and babyfaced the men looked in addition to rating their aggressiveness. These measures plus measured facial width-to-height ratio (FWHR) were used to examine cues to aggressiveness. Results. Accuracy coefficients, calculated by correlating rated aggressiveness with the men’s previously measured actual aggressiveness, were significant and equal for OA and YA. Accuracy was not moderated by distraction or accuracy motivation, suggesting automatic processing. A greater FWHR, lower attractiveness, and higher masculinity independently influenced rated aggressiveness by both age groups and also were valid cues to actual aggressiveness. Discussion. Despite previous evidence for positivity biases in OA, they can be just as accurate as YA when it comes to discerning actual differences in the aggressiveness of young men. PMID:23743626

  2. Transient age distributions in subsurface hydrologic systems

    NASA Astrophysics Data System (ADS)

    Engdahl, Nicholas B.; McCallum, James L.; Massoudieh, Arash

    2016-12-01

    Transient age distributions have received relatively little attention in the literature over the years compared to their steady-state counterparts. All natural systems are transient given enough time and it is becoming increasingly clear that understanding these effects and how they deviate from steady conditions will be important in the future. This article provides a high-level overview of the equations, techniques, and challenges encountered when considering transient age distributions. The age distribution represents the amount of water in a sample belonging to a particular age and the transient case implies that sampling the same location at two different times will result in different age distributions. These changes may be caused by transience in the boundary conditions, forcings (inputs), or physical changes in the geometry of the flow system. The governing equation for these problems contains separate dimensions for age and time and its solutions are more involved than the solute transport or steady-state age equations. Despite the complexity, many solutions have been derived for simplified, but transient, approximations and several numerical techniques exist for modeling more complex transient age distributions. This paper presents an overview of the existing solutions and contributes new examples of transient characteristic solutions and transient particle tracking simulations. The limitations for applying the techniques described herein are no longer theoretical or technological, but are now dominated by uncertainty in the physical properties of the flow systems and the lack of data for the historic inputs.

  3. Quantization of probability distributions under norm-based distortion measures II: Self-similar distributions

    NASA Astrophysics Data System (ADS)

    Delattre, Sylvain; Graf, Siegfried; Luschgy, Harald; Pages, Gilles

    2006-06-01

    For a probability measure P on and consider where the infimum is taken over all subsets [alpha] of with card([alpha])[less-than-or-equals, slant]n and V is a nondecreasing function. Under certain conditions on V, we derive the precise n-asymptotics of en for self-similar distributions P and we find the asymptotic performance of optimal quantizers using weighted empirical measures.

  4. Linking age, survival, and transit time distributions

    NASA Astrophysics Data System (ADS)

    Calabrese, Salvatore; Porporato, Amilcare

    2015-10-01

    Although the concepts of age, survival, and transit time have been widely used in many fields, including population dynamics, chemical engineering, and hydrology, a comprehensive mathematical framework is still missing. Here we discuss several relationships among these quantities by starting from the evolution equation for the joint distribution of age and survival, from which the equations for age and survival time readily follow. It also becomes apparent how the statistical dependence between age and survival is directly related to either the age dependence of the loss function or the survival-time dependence of the input function. The solution of the joint distribution equation also allows us to obtain the relationships between the age at exit (or death) and the survival time at input (or birth), as well as to stress the symmetries of the various distributions under time reversal. The transit time is then obtained as a sum of the age and survival time, and its properties are discussed along with the general relationships between their mean values. The special case of steady state case is analyzed in detail. Some examples, inspired by hydrologic applications, are presented to illustrate the theory with the specific results. This article was corrected on 11 Nov 2015. See the end of the full text for details.

  5. The Elderly's Reactions toward the Dying: The Effects of Perceived Age Similarity.

    ERIC Educational Resources Information Center

    Smith, Robert J.; And Others

    1982-01-01

    Investigated female older adults' (N=76) attitudes toward a similar- or dissimilar-aged dying patient versus a nondying patient. Confirmed less positive attitudes toward a terminal cancer patient. Age similarity did not appear to have strong effects on subjects' perceptions of patients. (Author/JAC)

  6. Magnesium and fluoride distribution in human cementum with age.

    PubMed

    Tsuboi, S; Nakagaki, H; Takami, Y; Eba, H; Kirkham, J; Robinson, C

    2000-12-01

    Sixty-two human teeth, obtained from subjects aged 11 to 80 years, were used to determine the magnesium and fluoride concentration and distribution with age in human cementum. Transverse sections were prepared from the root region of teeth. Samples, each 30 microm thick, were abraded in sequence from the cementum surface and the cemento-dentine junction by an abrasive micro-sampling technique. Magnesium concentrations were lower in the cementum surface, and increased towards the cemento-dentine junction (CDJ), while fluoride concentrations were higher in cementum surfaces and tended to decrease towards CDJ. Fluoride distribution patterns were similar to that reported earlier while average fluoride concentration increased with age, however, either no change or decreasing tendencies were observed with magnesium.

  7. Self-similarity in the chemical evolution of galaxies and the delay-time distribution of SNe Ia

    NASA Astrophysics Data System (ADS)

    Walcher, C. J.; Yates, R. M.; Minchev, I.; Chiappini, C.; Bergemann, M.; Bruzual, G.; Charlot, S.; Coelho, P. R. T.; Gallazzi, A.; Martig, M.

    2016-10-01

    Recent improvements in the age dating of stellar populations and single stars allow us to study the ages and abundance of stars and galaxies with unprecedented accuracy. We here compare the relation between age and α-element abundances for stars in the solar neighborhood to that of local, early-type galaxies. We find these two relations to be very similar. Both fall into two regimes with a shallow slope for ages younger than ~9 Gyr and a steeper slope for ages older than that value. This quantitative similarity seems surprising because of the different types of galaxies and scales involved. For the sample of early-type galaxies we also show that the data are inconsistent with literature delay-time distributions of either single- or double-Gaussian shape. The data are consistent with a power-law delay-time distribution. We thus confirm that the delay-time distribution inferred for the Milky Way from chemical evolution arguments must also apply to massive early-type galaxies. We also offer a tentative explanation for the seeming universality of the age-[α/Fe] relation: it is the manifestation of averaging different stellar populations with varying chemical evolution histories.

  8. Age-related impairments in discriminating perceptually similar objects parallel those observed in humans.

    PubMed

    Johnson, Sarah A; Turner, Sean M; Santacroce, Lindsay A; Carty, Katelyn N; Shafiq, Leila; Bizon, Jennifer L; Maurer, Andrew P; Burke, Sara N

    2017-03-25

    The ability to accurately remember distinct episodes is supported by high-level sensory discrimination. Performance on mnemonic similarity tasks, which test high-level discrimination, declines with advancing age in humans and these deficits have been linked to altered activity in hippocampal CA3 and dentate gyrus. Lesion studies in animal models, however, point to the perirhinal cortex as a brain region critical for sensory discriminations that serve memory. Reconciliation of the contributions of different regions within the cortical-hippocampal circuit requires the development of a discrimination paradigm comparable to the human mnemonic similarity task that can be used in rodents. In the present experiments, young and aged rats were cross-characterized on a spatial water maze task and two variants of an object discrimination task: one in which rats incrementally learned which object of a pair was rewarded and different pairs varied in their similarity (Experiment 1), and a second in which rats were tested on their ability to discriminate a learned target object from multiple lure objects with an increasing degree of feature overlap (Experiment 2). In Experiment 1, aged rats required more training than young to correctly discriminate between similar objects. Comparably, in Experiment 2, aged rats were impaired in discriminating a target object from lures when the pair shared more features. Discrimination deficits across experiments were correlated within individual aged rats, though, for the cohort tested, aged rats were not impaired overall in spatial learning and memory. This could suggest discrimination deficits emerging with age precede declines in spatial or episodic memory, an observation that has been made in humans. Findings of robust impairments in object discrimination abilities in the aged rats parallel results from human studies, supporting use of the developed tasks for mechanistic investigation of cortical-hippocampal circuit dysfunction in aging and

  9. Self-similar optical pulses in competing cubic-quintic nonlinear media with distributed coefficients

    SciTech Connect

    Zhang Jiefang; Tian Qing; Wang Yueyue; Dai Chaoqing; Wu Lei

    2010-02-15

    We present a systematic analysis of the self-similar propagation of optical pulses within the framework of the generalized cubic-quintic nonlinear Schroedinger equation with distributed coefficients. By appropriately choosing the relations between the distributed coefficients, we not only retrieve the exact self-similar solitonic solutions, but also find both the approximate self-similar Gaussian-Hermite solutions and compact solutions. Our analytical and numerical considerations reveal that proper choices of the distributed coefficients could make the unstable solitons stable and could restrict the nonlinear interaction between the neighboring solitons.

  10. Composition and acidification of the culture medium influences chronological aging similarly in vineyard and laboratory yeast.

    PubMed

    Murakami, Christopher J; Wall, Valerie; Basisty, Nathan; Kaeberlein, Matt

    2011-01-01

    Chronological aging has been studied extensively in laboratory yeast by culturing cells into stationary phase in synthetic complete medium with 2% glucose as the carbon source. During this process, acidification of the culture medium occurs due to secretion of organic acids, including acetic acid, which limits survival of yeast cells. Dietary restriction or buffering the medium to pH 6 prevents acidification and increases chronological life span. Here we set out to determine whether these effects are specific to laboratory-derived yeast by testing the chronological aging properties of the vineyard yeast strain RM11. Similar to the laboratory strain BY4743 and its haploid derivatives, RM11 and its haploid derivatives displayed increased chronological life span from dietary restriction, buffering the pH of the culture medium, or aging in rich medium. RM11 and BY4743 also displayed generally similar aging and growth characteristics when cultured in a variety of different carbon sources. These data support the idea that mechanisms of chronological aging are similar in both the laboratory and vineyard strains.

  11. Rapidly Developing Yeast Microcolonies Differentiate in a Similar Way to Aging Giant Colonies

    PubMed Central

    Váchová, Libuše; Hatáková, Ladislava; Čáp, Michal; Pokorná, Michaela; Palková, Zdena

    2013-01-01

    During their development and aging on solid substrates, yeast giant colonies produce ammonia, which acts as a quorum sensing molecule. Ammonia production is connected with alkalization of the surrounding medium and with extensive reprogramming of cell metabolism. In addition, ammonia signaling is important for both horizontal (colony centre versus colony margin) and vertical (upper versus lower cell layers) colony differentiations. The centre of an aging differentiated giant colony is thus composed of two major cell subpopulations, the subpopulation of long-living, metabolically active and stress-resistant cells that form the upper layers of the colony and the subpopulation of stress-sensitive starving cells in the colony interior. Here, we show that microcolonies originating from one cell pass through similar developmental phases as giant colonies. Microcolony differentiation is linked to ammonia signaling, and cells similar to the upper and lower cells of aged giant colonies are formed even in relatively young microcolonies. A comparison of the properties of these cells revealed a number of features that are similar in microcolonies and giant colonies as well as a few that are only typical of chronologically aged giant colonies. These findings show that colony age per se is not crucial for colony differentiation. PMID:23970946

  12. Predicting human age using regional morphometry and inter-regional morphological similarity

    NASA Astrophysics Data System (ADS)

    Wang, Xun-Heng; Li, Lihua

    2016-03-01

    The goal of this study is predicting human age using neuro-metrics derived from structural MRI, as well as investigating the relationships between age and predictive neuro-metrics. To this end, a cohort of healthy subjects were recruited from 1000 Functional Connectomes Project. The ages of the participations were ranging from 7 to 83 (36.17+/-20.46). The structural MRI for each subject was preprocessed using FreeSurfer, resulting in regional cortical thickness, mean curvature, regional volume and regional surface area for 148 anatomical parcellations. The individual age was predicted from the combination of regional and inter-regional neuro-metrics. The prediction accuracy is r = 0.835, p < 0.00001, evaluated by Pearson correlation coefficient between predicted ages and actual ages. Moreover, the LASSO linear regression also found certain predictive features, most of which were inter-regional features. The turning-point of the developmental trajectories in human brain was around 40 years old based on regional cortical thickness. In conclusion, structural MRI could be potential biomarkers for the aging in human brain. The human age could be successfully predicted from the combination of regional morphometry and inter-regional morphological similarity. The inter-regional measures could be beneficial to investigating human brain connectome.

  13. Stability of age-related deficits in the mnemonic similarity task across task variations.

    PubMed

    Stark, Shauna M; Stevenson, Rebecca; Wu, Claudia; Rutledge, Samantha; Stark, Craig E L

    2015-06-01

    Several studies in our lab and others have demonstrated age-related declines in mnemonic discrimination during a recognition memory paradigm using repeated items, similar lures, and novel foils. In particular, older adults exhibit a shift in lure discriminability, identifying similar lures as old items at a greater rate than young adults. This shift likely reflects deficits in pattern separation processing as a result of underlying changes in the dentate gyrus of the hippocampus. Here, we explored whether alterations in the task design could rescue the age-related impairment or whether it was ubiquitous as one might expect if the neurobiological mechanisms were truly disturbed by typical aging. Despite overt instructions to study item details during encoding, we replicated the age-related deficit in mnemonic discrimination. We established reliable effects with short lists of stimuli and with repeated testing. Altering the task design from a study/test to a continuous recognition paradigm replicated the age-related shift in lure discrimination as well. Modifying the task to an old/new response (rather than old/similar/new) showed the same effect and a d' analysis showed that lure items were more akin to target items in older adults. Finally, we varied the test instructions in order to promote gist or veridical responses in the old/new task. Even these overt veridical test instructions did not ameliorate older adults' lure discrimination problems. Together, these findings demonstrate the robust nature of this age-related deficit and support the hypothesis that typical aging results in neurobiological changes that underlie this impairment.

  14. Similar verbal memory impairments in schizophrenia and healthy aging. Implications for understanding of neural mechanisms.

    PubMed

    Silver, Henry; Bilker, Warren B

    2015-03-30

    Memory is impaired in schizophrenia patients but it is not clear whether this is specific to the illness and whether different types of memory (verbal and nonverbal) or memories in different cognitive domains (executive, object recognition) are similarly affected. To study relationships between memory impairments and schizophrenia we compared memory functions in 77 schizophrenia patients, 58 elderly healthy individuals and 41 young healthy individuals. Tests included verbal associative and logical memory and memory in executive and object recognition domains. We compared relationships of memory functions to each other and to other cognitive functions including psychomotor speed and verbal and spatial working memory. Compared to the young healthy group, schizophrenia patients and elderly healthy individuals showed similar severe impairment in logical memory and in the ability to learn new associations (NAL), and similar but less severe impairment in spatial working memory and executive and object memory. Verbal working memory was significantly more impaired in schizophrenia patients than in the healthy elderly. Verbal episodic memory impairment in schizophrenia may share common mechanisms with similar impairment in healthy aging. Impairment in verbal working memory in contrast may reflect mechanisms specific to schizophrenia. Study of verbal explicit memory impairment tapped by the NAL index may advance understanding of abnormal hippocampus dependent mechanisms common to schizophrenia and aging.

  15. Collaborative distribution of remote sensing data based on user profile similarity

    NASA Astrophysics Data System (ADS)

    Li, Xinguang; Liu, Yang; Li, Yunhua; Wang, Yuhua

    2015-12-01

    With the rapid development of earth observation technology and the rapid increase of remote sensors, the amount of remote sensing data rapidly expands, which leads to increasingly outstanding contradiction of "more and less" remote sensing data. According to the user's preference characteristics, intelligent distribution of remote sensing data is an effective solution to the problem. The user profile model is the basis of intelligent distribution of remote sensing data. This paper intends to (1) establish the user profile model which describes the user's preference characteristics of remote sensing data; (2) develop similarity measure methods of user profile models, according to which similarities of user preference characteristics can be calculated; (3) put forward prediction methods of the user's ratings of remote sensing data, based on which remote sensing data can be collaboratively distributed.

  16. Self-similar distribution function and the production of runaway electrons

    SciTech Connect

    Silin, V.P.; Uryupin, S.A.

    1992-09-01

    The theory of the suppression of anomalous plasma resistivity due to ion-cyclotron turbulence resulting from the formation of runaway electrons has long attracted the attention of researchers. The purpose of this communication was to describe how the approach to the asymptotic regime noted in Vekshtein, et al. occurs, and how the electron distribution is transformed as a result. It was shown that over a time much larger than that required for the temperature to double, a self-similar distribution is obtained for the bulk of the electrons. It was concluded that the self-similar distribution occurs for the bulk of the particles, followed by leakage at times much larger than the already anomalously large time t{sub 0}.

  17. Predicting Lexical Priming Effects from Distributional Semantic Similarities: A Replication with Extension

    PubMed Central

    Günther, Fritz; Dudschig, Carolin; Kaup, Barbara

    2016-01-01

    In two experiments, we attempted to replicate and extend findings by Günther et al. (2016) that word similarity measures obtained from distributional semantics models—Latent Semantic Analysis (LSA) and Hyperspace Analog to Language (HAL)—predict lexical priming effects. To this end, we used the pseudo-random method to generate item material while systematically controlling for word similarities introduced by Günther et al. (2016) which was based on LSA cosine similarities (Experiment 1) and HAL cosine similarities (Experiment 2). Extending the original study, we used semantic spaces created from far larger corpora, and implemented several additional methodological improvements. In Experiment 1, we only found a significant effect of HAL cosines on lexical decision times, while we found significant effects for both LSA and HAL cosines in Experiment 2. As further supported by an analysis of the pooled data from both experiments, this indicates that HAL cosines are a better predictor of priming effects than LSA cosines. Taken together, the results replicate the finding that priming effects can be predicted from distributional semantic similarity measures. PMID:27822195

  18. Hind limb unloading, a model of spaceflight conditions, leads to decreased B lymphopoiesis similar to aging.

    PubMed

    Lescale, Chloé; Schenten, Véronique; Djeghloul, Dounia; Bennabi, Meriem; Gaignier, Fanny; Vandamme, Katleen; Strazielle, Catherine; Kuzniak, Isabelle; Petite, Hervé; Dosquet, Christine; Frippiat, Jean-Pol; Goodhardt, Michele

    2015-02-01

    Within the bone marrow, the endosteal niche plays a crucial role in B-cell differentiation. Because spaceflight is associated with osteoporosis, we investigated whether changes in bone microstructure induced by a ground-based model of spaceflight, hind limb unloading (HU), could affect B lymphopoiesis. To this end, we analyzed both bone parameters and the frequency of early hematopoietic precursors and cells of the B lineage after 3, 6, 13, and 21 d of HU. We found that limb disuse leads to a decrease in both bone microstructure and the frequency of B-cell progenitors in the bone marrow. Although multipotent hematopoietic progenitors were not affected by HU, a decrease in B lymphopoiesis was observed as of the common lymphoid progenitor (CLP) stage with a major block at the progenitor B (pro-B) to precursor B (pre-B) cell transition (5- to 10-fold decrease). The modifications in B lymphopoiesis were similar to those observed in aged mice and, as with aging, decreased B-cell generation in HU mice was associated with reduced expression of B-cell transcription factors, early B-cell factor (EBF) and Pax5, and an alteration in STAT5-mediated IL-7 signaling. These findings demonstrate that mechanical unloading of hind limbs results in a decrease in early B-cell differentiation resembling age-related modifications in B lymphopoiesis.

  19. Altitude Investigation of Gas Temperature Distribution at Turbine of Three Similar Axial-Flow Turbojet Engines

    NASA Technical Reports Server (NTRS)

    Prince, W.R.; Schulze, F.W.

    1952-01-01

    An investigation of the effect of inlet pressure, corrected engine speed, and turbine temperature level on turbine-inlet gas temperature distributions was conducted on a J40-WE-6, interim J40-WE-6, and prototype J40-WE-8 turbojet engine in the altitude wind tunnel at the NAC.4 Lewis laboratory. The engines were investigated over a range of simulated pressure altitudes from 15,000 to 55,000 feet, flight Mach numbers from 0.12 to 0.64, and corrected engine speeds from 7198 to 8026 rpm, The gas temperature distribution at the turbine of the three engines over the range of operating conditions investigated was considered satisfactory from the standpoint of desired temperature distribution with one exception - the distribution for the J40-WE-6 engine indicated a trend with decreasing engine-inlet pressure for the temperature to exceed the desired in the region of the blade hub. Installation of a compressor-outlet mixer vane assembly remedied this undesirable temperature distribution, The experimental data have shown that turbine-inlet temperature distributions are influenced in the expected manner by changes in compressor-outlet pressure or mass-flow distribution and by changes in combustor hole-area distribution. The similarity between turbine-inlet and turbine-outlet temperature distribution indicated only a small shift in temperature distribution imposed by the turbine rotors. The attainable jet thrusts of the three engines were influenced in different degrees and directions by changes in temperature distributions with change in engine-inlet pressure. Inability to match the desired temperature distribution resulted, for the J40-WE-6 engine, in an 11-percent thrust loss based on an average turbine-inlet temperature of 1500 F at an engine-inlet pressure of 500 pounds per square foot absolute. Departure from the desired temperature distribution in the Slade tip region results, for the prototype J40-WE-8 engine, in an attainable thrust increase of 3 to 4 percent as

  20. Data-Dependent Label Distribution Learning for Age Estimation.

    PubMed

    He, Zhouzhou; Li, Xi; Zhang, Zhongfei; Wu, Fei; Geng, Xin; Zhang, Yaqing; Yang, Ming-Hsuan; Zhuang, Yueting

    2017-01-18

    As an important and challenging problem in computer vision, face age estimation is typically cast as a classification or regression problem over a set of face samples with respect to several ordinal age labels, which have intrinsically cross-age correlations across adjacent age dimensions. As a result, such correlations usually lead to the age label ambiguities of the face samples. Namely, each face sample is associated with a latent label distribution that encodes the cross-age correlation information on label ambiguities. Motivated by this observation, we propose a totally data-driven label distribution learning approach to adaptively learn the latent label distributions. The proposed approach is capable of effectively discovering the intrinsic age distribution patterns for cross-age correlation analysis on the basis of the local context structures of face samples. Without any prior assumptions on the forms of label distribution learning, our approach is able to flexibly model the sample-specific context aware label distribution properties by solving a multi-task problem, which jointly optimizes the tasks of age-label distribution learning and age prediction for individuals. Experimental results demonstrate the effectiveness of our approach.

  1. Martian crater size distributions and terrain age

    NASA Technical Reports Server (NTRS)

    Barlow, N. G.; Strom, R. G.

    1984-01-01

    The crater size/frequency distributions of large ( 8 km) craters on the Moon and terrestrial planets display two very different curves representing two crater populations. The heavily cratered regions of the Moon, Mercury, and Mars show the same highly structured curve which cannot be represented by a single slope distribution function. In contrast, the lunar post mare crater population has a size/frequency distribution which differs significantly from that in the highlands over the same diameter range, and can be represented by a single-slope distribution function of -2.8 differential. On areas of martian lightly cratered northern plains, the crater population is essentially identical to that of the post mare population. This indicates that the same two families of impacting objects were responsible for the cratering records on both Moon and Mars. The thickness of mantling material varies among the various plains units, and can be calculated from the depth/diameter scaling relations for martian craters.

  2. Efficient string similarity join in multi-core and distributed systems

    PubMed Central

    Yan, Cairong; Zhao, Xue; Zhang, Qinglong; Huang, Yongfeng

    2017-01-01

    In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets. PMID:28278177

  3. Efficient string similarity join in multi-core and distributed systems.

    PubMed

    Yan, Cairong; Zhao, Xue; Zhang, Qinglong; Huang, Yongfeng

    2017-01-01

    In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets.

  4. A Comparison of the Sexual Behaviors and Attitudes of Adolescent Girls with Older vs. Similar-Aged Boyfriends

    ERIC Educational Resources Information Center

    Gowen, L. Kris; Feldman, S. Shirley; Diaz, Rafael; Yisrael, Donnovan Somera

    2004-01-01

    Sexual behaviors and attitudes of female adolescents were studied as a function of age of boyfriend. Boyfriend's age was dichotomized: similar-aged was defined as within 2 years of the girls' age; older aged was 3 or more years older than the girl. A school-based, ethnically diverse sample of 9th-grade girls (N = 146) who had been in a serious…

  5. Age distribution among NASA scientists and engineers

    NASA Technical Reports Server (NTRS)

    Ciancone, Michael L.

    1989-01-01

    The loss of technical expertise through attrition in NASA and the aerospace industry is discussed. This report documents historical age-related information for scientific and engineering personnel in general and the NASA Lewis Research Center in particular, for 1968 through 1987. Recommendations are made to promote discussion and to establish the groundwork for action.

  6. PATTERNS OF ROOT GROWTH, TURNOVER, AND DISTRIBUTION IN DIFFERENT AGED PONDEROSA PINE STANDS

    EPA Science Inventory

    The objectives of this study are to examine the spatial distribution of roots in relation to canopy size and tree distribution, and to determine if rates of fine root production and turnover are similar in the different aged stands. During the fall of 1998, 54 clear plexiglass t...

  7. Size distribution of dust grains: A problem of self-similarity

    NASA Technical Reports Server (NTRS)

    Henning, TH.; Dorschner, J.; Guertler, J.

    1989-01-01

    Distribution functions describing the results of natural processes frequently show the shape of power laws, e.g., mass functions of stars and molecular clouds, velocity spectrum of turbulence, size distributions of asteroids, micrometeorites and also interstellar dust grains. It is an open question whether this behavior is a result simply coming about by the chosen mathematical representation of the observational data or reflects a deep-seated principle of nature. The authors suppose the latter being the case. Using a dust model consisting of silicate and graphite grains Mathis et al. (1977) showed that the interstellar extinction curve can be represented by taking a grain radii distribution of power law type n(a) varies as a(exp -p) with 3.3 less than or equal to p less than or equal to 3.6 (example 1) as a basis. A different approach to understanding power laws like that in example 1 becomes possible by the theory of self-similar processes (scale invariance). The beta model of turbulence (Frisch et al., 1978) leads in an elementary way to the concept of the self-similarity dimension D, a special case of Mandelbrot's (1977) fractal dimension. In the frame of this beta model, it is supposed that on each stage of a cascade the system decays to N clumps and that only the portion beta N remains active further on. An important feature of this model is that the active eddies become less and less space-filling. In the following, the authors assume that grain-grain collisions are such a scale-invarient process and that the remaining grains are the inactive (frozen) clumps of the cascade. In this way, a size distribution n(a) da varies as a(exp -(D+1))da (example 2) results. It seems to be highly probable that the power law character of the size distribution of interstellar dust grains is the result of a self-similarity process. We can, however, not exclude that the process leading to the interstellar grain size distribution is not fragmentation at all. It could be, e

  8. Strategic Decision-Making Learning from Label Distributions: An Approach for Facial Age Estimation

    PubMed Central

    Zhao, Wei; Wang, Han

    2016-01-01

    Nowadays, label distribution learning is among the state-of-the-art methodologies in facial age estimation. It takes the age of each facial image instance as a label distribution with a series of age labels rather than the single chronological age label that is commonly used. However, this methodology is deficient in its simple decision-making criterion: the final predicted age is only selected at the one with maximum description degree. In many cases, different age labels may have very similar description degrees. Consequently, blindly deciding the estimated age by virtue of the highest description degree would miss or neglect other valuable age labels that may contribute a lot to the final predicted age. In this paper, we propose a strategic decision-making label distribution learning algorithm (SDM-LDL) with a series of strategies specialized for different types of age label distribution. Experimental results from the most popular aging face database, FG-NET, show the superiority and validity of all the proposed strategic decision-making learning algorithms over the existing label distribution learning and other single-label learning algorithms for facial age estimation. The inner properties of SDM-LDL are further explored with more advantages. PMID:27367691

  9. Self-similar structure and experimental signatures of suprathermal ion distribution in inertial confinement fusion implosions

    SciTech Connect

    Kagan, Grigory; Svyatskiy, D.; Rinderknecht, H. G.; Rosenberg, M. J.; Zylstra, A. B.; Huang, C. -K.; McDevitt, C. J.

    2015-09-03

    The distribution function of suprathermal ions is found to be self-similar under conditions relevant to inertial confinement fusion hot spots. By utilizing this feature, interference between the hydrodynamic instabilities and kinetic effects is for the first time assessed quantitatively to find that the instabilities substantially aggravate the fusion reactivity reduction. Thus, the ion tail depletion is also shown to lower the experimentally inferred ion temperature, a novel kinetic effect that may explain the discrepancy between the exploding pusher experiments and rad-hydro simulations and contribute to the observation that temperature inferred from DD reaction products is lower than from DT at the National Ignition Facility.

  10. Prediction of oil contamination distribution in aquifers using self similar solutions

    NASA Astrophysics Data System (ADS)

    Pistiner, Arieh

    2016-12-01

    Oil contaminant migration in an aquifer is analyzed by applying some power law relationships between the porous medium parameters and oil saturation. Such an application generates a self-similar model whose solutions are used to analyze the effect of the porous structure and the oil properties on the oil migration in the aquifer. By using hypothetical saturation data, the model was used to find the characteristic length and time scales of the aquifer, and then to predict the temporal saturation distribution of the oil contamination in the aquifer.

  11. Martian valleys: morphology, distribution, age, and origin.

    PubMed

    Pieri, D C

    1980-11-21

    Branching valley networks throughout the heavily cratered terrain of Mars exhibit no compelling evidence for formation by rainfall-fed erosion. The networks are diffuse and inefficient, with irregular tributary junction angles and large, undissected intervalley areas. Rather, the deeply entrenched canyons, with blunt amphitheater terminations, cliff-bench wall topography, lack of evidence of interior erosion by flow, and clear structural control, suggest headward extension by basal sapping. The size-frequency distributions of impact craters in these valleys and in the heavily cratered terrain that surrounds them are statistically indistinguishable, suggesting that valley formation has not occurred on Mars for billions of years.

  12. Spatio-Temporal Distribution Characteristics and Trajectory Similarity Analysis of Tuberculosis in Beijing, China

    PubMed Central

    Li, Lan; Xi, Yuliang; Ren, Fu

    2016-01-01

    Tuberculosis (TB) is an infectious disease with one of the highest reported incidences in China. The detection of the spatio-temporal distribution characteristics of TB is indicative of its prevention and control conditions. Trajectory similarity analysis detects variations and loopholes in prevention and provides urban public health officials and related decision makers more information for the allocation of public health resources and the formulation of prioritized health-related policies. This study analysed the spatio-temporal distribution characteristics of TB from 2009 to 2014 by utilizing spatial statistics, spatial autocorrelation analysis, and space-time scan statistics. Spatial statistics measured the TB incidence rate (TB patients per 100,000 residents) at the district level to determine its spatio-temporal distribution and to identify characteristics of change. Spatial autocorrelation analysis was used to detect global and local spatial autocorrelations across the study area. Purely spatial, purely temporal and space-time scan statistics were used to identify purely spatial, purely temporal and spatio-temporal clusters of TB at the district level. The other objective of this study was to compare the trajectory similarities between the incidence rates of TB and new smear-positive (NSP) TB patients in the resident population (NSPRP)/new smear-positive TB patients in the TB patient population (NSPTBP)/retreated smear-positive (RSP) TB patients in the resident population (RSPRP)/retreated smear-positive TB patients in the TB patient population (RSPTBP) to detect variations and loopholes in TB prevention and control among the districts in Beijing. The incidence rates in Beijing exhibited a gradual decrease from 2009 to 2014. Although global spatial autocorrelation was not detected overall across all of the districts of Beijing, individual districts did show evidence of local spatial autocorrelation: Chaoyang and Daxing were Low-Low districts over the six

  13. Martian valleys - Morphology, distribution, age, and origin

    NASA Technical Reports Server (NTRS)

    Pieri, D. C.

    1980-01-01

    The article summarizes the geological and geomorphological evidence concerning the formation of the valley networks of Mars which were observed in the Mariner 9 and Viking Orbiter images. There is no clear evidence of direct fluid erosion in any Martian valley. The networks are diffuse and inefficient, with irregular tributary junction angles and large, undissected intervalley regions. The deeply entrenched canyons, with steep-walled amphitheater terminations suggest headward extension (sapping) by basal undermining and wall collapse. It is believed that valley formation has not occurred on Mars for billions of years because the size-frequency distributions of impact craters in these valleys and in the heavily cratered terrain which surrounds them are statistically insignificant.

  14. HTRA1 variant confers similar risks to geographic atrophy and neovascular age-related macular degeneration.

    PubMed

    Cameron, D Joshua; Yang, Zhenglin; Gibbs, Daniel; Chen, Haoyu; Kaminoh, Yuuki; Jorgensen, Adam; Zeng, Jiexi; Luo, Ling; Brinton, Eric; Brinton, Gregory; Brand, John M; Bernstein, Paul S; Zabriskie, Norman A; Tang, Shibo; Constantine, Ryan; Tong, Zongzhong; Zhang, Kang

    2007-05-02

    Age-related macular degeneration (AMD) is the most common cause of irreversible visual impairment in the developed world. The two forms of advanced AMD, geographic atrophy (GA) and choroidal neovascularization (wet AMD), represent two types of degenerative processes in the macula that lead to loss of central vision. Soft confluent drusen, characterized by deposits in macula without visual loss are considered a precursor of advanced AMD. A single nucleotide polymorphism, rs11200638, in the promoter of HTRA1 has been shown to increases the risk for wet AMD. However, its impact on soft confluent drusen and GA or the relationship between them is unclear. To better understand the role the HTRA1 polymorphism plays in AMD subtypes, we genotyped an expanded Utah population with 658 patients having advanced AMD or soft confluent drusen and 294 normal controls and found that the rs11200638 was significantly associated with GA. This association remains significant conditional on LOC387715 rs10490924. In addition, rs11200638 was significantly associated with soft confluent drusen, which are strongly immunolabeled with HTRA1 antibody in an AMD eye with GA similar to wet AMD. Two-locus analyses were performed for CFH Y402H variant at 1q31 and the HTRA1 polymorphism. Together CFH and HTRA1 risk variants increase the odds of having AMD by more than 40 times. These findings expand the role of HTRA1 in AMD. Understanding the underlying molecular mechanism will provide an important insight in pathogenesis of AMD.

  15. Distributed Similarity based Clustering and Compressed Forwarding for wireless sensor networks.

    PubMed

    Arunraja, Muruganantham; Malathi, Veluchamy; Sakthivel, Erulappan

    2015-11-01

    Wireless sensor networks are engaged in various data gathering applications. The major bottleneck in wireless data gathering systems is the finite energy of sensor nodes. By conserving the on board energy, the life span of wireless sensor network can be well extended. Data communication being the dominant energy consuming activity of wireless sensor network, data reduction can serve better in conserving the nodal energy. Spatial and temporal correlation among the sensor data is exploited to reduce the data communications. Data similar cluster formation is an effective way to exploit spatial correlation among the neighboring sensors. By sending only a subset of data and estimate the rest using this subset is the contemporary way of exploiting temporal correlation. In Distributed Similarity based Clustering and Compressed Forwarding for wireless sensor networks, we construct data similar iso-clusters with minimal communication overhead. The intra-cluster communication is reduced using adaptive-normalized least mean squares based dual prediction framework. The cluster head reduces the inter-cluster data payload using a lossless compressive forwarding technique. The proposed work achieves significant data reduction in both the intra-cluster and the inter-cluster communications, with the optimal data accuracy of collected data.

  16. Growth of river delta networks: Thresholds, periodicity, aging and self similarity (Invited)

    NASA Astrophysics Data System (ADS)

    Jerolmack, D. J.; Reitz, M. D.

    2010-12-01

    The surfaces of river deltas and alluvial fans (collectively fans) are often dissected by a small number of channels radiating from the fan apex. These dispersive, depositional systems do not exhibit the fractal scaling typical of erosional drainage networks. On long timescales, fan channels migrate via avulsion - the process of channel bed deposition and abandonment. What governs the selection of new flow paths, or the ultimate number of active channels, is poorly understood. Here we present results of an experimental fan that allow us to examine the growth of a depositional channel network. Flow over the fan collapses into a single channel whose dimensions adjust to threshold transport conditions for the imposed sediment load. This channelization causes localized shoreline growth, which diminishes transport capacity of the channel until the slope drops below the threshold value. This leads to deposition within the channel and widespread flooding; avulsion is completed when a new channel path is selected. This cycle is remarkably periodic, and dynamics suggest that fan slope oscillates between two thresholds - entrainment and distrainment - analogous to static and dynamic angles of repose in grain flows. Selection of a new flow path is inherently stochastic, but previously abandoned channels act as significant attractors for the flow. In the early stages of fan growth, new channels are likely to be created. Once a critical density of flow paths has been established, however, the flow oscillates among the same 3-5 channels indefinitely. These dynamics are similar to the aging phenomenon observed in the growth of fractures in brittle materials under stress. We demonstrate that a directed random walk model with memory quantitatively reproduces these dynamics and limiting behavior, and is consistent with natural fans. Because our experimental fan is built by the recurring avulsion sequence, its shoreline shape is a series of lobes that indicate persistent upstream

  17. Phytoplankton distribution in three thermally different but edaphically similar reactor cooling reservoirs

    SciTech Connect

    Wilde, E W

    1982-01-01

    Phytoplankton community structure and the physicochemical characteristics of three reactor cooling reservoirs in close proximity and of similar age and bottom type were studied during 1978. The three reservoirs differed in thermal alteration resulting from reactor cooling water as follows: (1) considerable heating with lake-wide temperatures >30/sup 0/C, even in winter; (2) a maximal 5/sup 0/C increase occurring in only one of three major arms of the reservoir; and (3) no thermal effluent received during the study period. Considerable spatial and temporal differences in water quality and phytoplankton community structure were observed; however, water temperature independent of other environmental factors (e.g., light and nutrients) was found to be a relatively unimportant variable for explaining phytoplankton periodicity.

  18. The distribution of lobate debris aprons and similar flows on Mars

    NASA Technical Reports Server (NTRS)

    Squyres, S. W.

    1979-01-01

    Planet-wide mapping of lobate debris aprons and other similar flows on Mars shows a strong concentration in two latitudinal bands roughly 25 deg wide and centered at 40 deg N and 45 deg S. This distribution supports the idea that these flows form when erosional debris is transported downslope and becomes mixed with ice deposited from the atmosphere, as these latitudes should receive high seasonal H2O frost deposition relative to the rest of the planet. Flows are found in the northern hemisphere band wherever old highland surfaces occur but are found in the southern hemisphere only near the two major impact basins, Argyre and Hellas. These areas are apparently characterized by mass wasting that is rapid relative to most of the southern hemisphere highlands. The rate of mass wasting may be related to the degree of consolidation of highland material.

  19. Self-similar structure and experimental signatures of suprathermal ion distribution in inertial confinement fusion implosions

    DOE PAGES

    Kagan, Grigory; Svyatskiy, D.; Rinderknecht, H. G.; ...

    2015-09-03

    The distribution function of suprathermal ions is found to be self-similar under conditions relevant to inertial confinement fusion hot spots. By utilizing this feature, interference between the hydrodynamic instabilities and kinetic effects is for the first time assessed quantitatively to find that the instabilities substantially aggravate the fusion reactivity reduction. Thus, the ion tail depletion is also shown to lower the experimentally inferred ion temperature, a novel kinetic effect that may explain the discrepancy between the exploding pusher experiments and rad-hydro simulations and contribute to the observation that temperature inferred from DD reaction products is lower than from DT atmore » the National Ignition Facility.« less

  20. Aging of distribution composite insulators under environmental and electrical stresses

    SciTech Connect

    de Oliveira, S.M. ); de Tourreil, C.H

    1990-04-01

    Seven types of commercially available distribution composite insulators with sheds made of EPR or epoxy resin have been subjected to various functional aging tests recommended by the IEC or the IEEE. The influence of UV radiation on the aging of the shed materials was also evaluated. The usefulness of the various aging and diagnostic tests is discussed and a modification of the recommended test procedures is proposed in order to improve the evaluation of the long term performance of these insulators.

  1. Early Visual Tagging: Effects of Target-Distractor Similarity and Old Age on Search, Subitization, and Counting

    ERIC Educational Resources Information Center

    Watson, Derrick G.; Maylor, Elizabeth A.; Allen, Gareth E. J.; Bruce, Lucy A. M.

    2007-01-01

    Three experiments examined the effects of target-distractor (T-D) similarity and old age on the efficiency of searching for single targets and enumerating multiple targets. Experiment 1 showed that increasing T-D similarity selectively reduced the efficiency of enumerating small (less than 4) numerosities (subitizing) but had little effect on…

  2. Influence of the source distribution on the age distribution of galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Lerche, I.; Schlickeiser, R.

    1985-01-01

    The age distribution of galactic cosmic rays in the diffusion approximation is calculated. The influence of the scale height of the spatial source distribution on the mean age of particles arriving at the solar system is discussed. The broader the source distribution with respect to the galactic plane, the longer the mean age. This result provides a natural explanation for the shorter mean age of secondary cosmic rays compared to primary cosmic rays necessary for the understanding of the observed secondary/primary ratio.

  3. A lognormal distribution of the lengths of terminal twigs on self-similar branches of elm trees.

    PubMed

    Koyama, Kohei; Yamamoto, Ken; Ushio, Masayuki

    2017-01-11

    Lognormal distributions and self-similarity are characteristics associated with a wide range of biological systems. The sequential breakage model has established a link between lognormal distributions and self-similarity and has been used to explain species abundance distributions. To date, however, there has been no similar evidence in studies of multicellular organismal forms. We tested the hypotheses that the distribution of the lengths of terminal stems of Japanese elm trees (Ulmus davidiana), the end products of a self-similar branching process, approaches a lognormal distribution. We measured the length of the stem segments of three elm branches and obtained the following results: (i) each occurrence of branching caused variations or errors in the lengths of the child stems relative to their parent stems; (ii) the branches showed statistical self-similarity; the observed error distributions were similar at all scales within each branch and (iii) the multiplicative effect of these errors generated variations of the lengths of terminal twigs that were well approximated by a lognormal distribution, although some statistically significant deviations from strict lognormality were observed for one branch. Our results provide the first empirical evidence that statistical self-similarity of an organismal form generates a lognormal distribution of organ sizes.

  4. Theoretical foundation for measuring the groundwater age distribution.

    SciTech Connect

    Gardner, William Payton; Arnold, Bill Walter

    2014-01-01

    In this study, we use PFLOTRAN, a highly scalable, parallel, flow and reactive transport code to simulate the concentrations of 3H, 3He, CFC-11, CFC-12, CFC-113, SF6, 39Ar, 81Kr, 4He and themean groundwater age in heterogeneous fields on grids with an excess of 10 million nodes. We utilize this computational platform to simulate the concentration of multiple tracers in high-resolution, heterogeneous 2-D and 3-D domains, and calculate tracer-derived ages. Tracer-derived ages show systematic biases toward younger ages when the groundwater age distribution contains water older than the maximum tracer age. The deviation of the tracer-derived age distribution from the true groundwater age distribution increases with increasing heterogeneity of the system. However, the effect of heterogeneity is diminished as the mean travel time gets closer the tracer age limit. Age distributions in 3-D domains differ significantly from 2-D domains. 3D simulations show decreased mean age, and less variance in age distribution for identical heterogeneity statistics. High-performance computing allows for investigation of tracer and groundwater age systematics in high-resolution domains, providing a platform for understanding and utilizing environmental tracer and groundwater age information in heterogeneous 3-D systems. Groundwater environmental tracers can provide important constraints for the calibration of groundwater flow models. Direct simulation of environmental tracer concentrations in models has the additional advantage of avoiding assumptions associated with using calculated groundwater age values. This study quantifies model uncertainty reduction resulting from the addition of environmental tracer concentration data. The analysis uses a synthetic heterogeneous aquifer and the calibration of a flow and transport model using the pilot point method. Results indicate a significant reduction in the uncertainty in permeability with the addition of environmental tracer data, relative

  5. Age- and Hypertension-Associated Protein Aggregates in Mouse Heart Have Similar Proteomic Profiles.

    PubMed

    Ayyadevara, Srinivas; Mercanti, Federico; Wang, Xianwei; Mackintosh, Samuel G; Tackett, Alan J; Prayaga, Sastry V S; Romeo, Francesco; Shmookler Reis, Robert J; Mehta, Jawahar L

    2016-05-01

    Neurodegenerative diseases are largely defined by protein aggregates in affected tissues. Aggregates contain some shared components as well as proteins thought to be specific for each disease. Aggregation has not previously been reported in the normal, aging heart or the hypertensive heart. Detergent-insoluble protein aggregates were isolated from mouse heart and characterized on 2-dimensional gels. Their levels increased markedly and significantly with aging and after sustained angiotensin II-induced hypertension. Of the aggregate components identified by high-resolution proteomics, half changed in abundance with age (392/787) or with sustained hypertension (459/824), whereas 30% (273/901) changed concordantly in both, each P<0.05. One fifth of these proteins were previously associated with age-progressive neurodegenerative or cardiovascular diseases, or both (eg, ApoE, ApoJ, ApoAIV, clusterin, complement C3, and others involved in stress-response and protein-homeostasis pathways). Because fibrosis is a characteristic of both aged and hypertensive hearts, we posited that aging of fibroblasts may contribute to the aggregates observed in cardiac tissue. Indeed, as cardiac myofibroblasts "senesced" (approached their replicative limit) in vitro, they accrued aggregates with many of the same constituent proteins observed in vivo during natural aging or sustained hypertension. In summary, we have shown for the first time that compact (detergent-insoluble) protein aggregates accumulate during natural aging, chronic hypertension, and in vitro myofibroblast senescence, sharing many common proteins. Thus, aggregates that arise from disparate causes (aging, hypertension, and replicative senescence) may have common underlying mechanisms of accrual.

  6. Transcriptional analysis of histone deacetylase family members reveal similarities between differentiating and aging spermatogonial stem cells.

    PubMed

    Kofman, Amber E; Huszar, Jessica M; Payne, Christopher J

    2013-02-01

    The differentiation of adult stem cells involves extensive chromatin remodeling, mediated in part by the gene products of histone deacetylase (HDAC) family members. While the transcriptional downregulation of HDACs can impede stem cell self-renewal in certain contexts, it may also promote stem cell maintenance under other circumstances. In self-renewing, differentiating, and aging spermatogonial stem cells (SSCs), the gene expression dynamics of HDACs have not yet been characterized. To gain further insight with these studies, we analyzed the transcriptional profiles of six HDAC family members, previously identified to be the most highly expressed in self-renewing SSCs, during stem cell differentiation and aging. Here we discovered that in both differentiating and aging SSCs the expression of Sirt4 increases, while the expression of Hdac2, Hdac6, and Sirt1 decreases. When SSCs are exposed to the lifespan-enhancing drug rapamycin in vivo, the resultant HDAC gene expression patterns are opposite of those seen in the differentiating and aging SSCs, with increased Hdac2, Hdac6, and Sirt1 and decreased Hdac8, Hdac9, and Sirt4. Our findings suggest that HDACs important for stem cell maintenance and oxidative capacity are downregulated as adult stem cells differentiate or age. These results provide important insights into the epigenetic regulation of stem cell differentiation and aging in mammals.

  7. Self-similar distribution of oil spills in European coastal waters

    NASA Astrophysics Data System (ADS)

    Redondo, Jose M; Platonov, Alexei K

    2009-01-01

    Marine pollution has been highlighted thanks to the advances in detection techniques as well as increasing coverage of catastrophes (e.g. the oil tankers Amoco Cadiz, Exxon Valdez, Erika, and Prestige) and of smaller oil spills from ships. The new satellite based sensors SAR and ASAR and new methods of oil spill detection and analysis coupled with self-similar statistical techniques allow surveys of environmental pollution monitoring large areas of the ocean. We present a statistical analysis of more than 700 SAR images obtained during 1996-2000, also comparing the detected small pollution events with the historical databases of great marine accidents during 1966-2004 in European coastal waters. We show that the statistical distribution of the number of oil spills as a function of their size corresponds to Zipf's law, and that the common small spills are comparable to the large accidents due to the high frequency of the smaller pollution events. Marine pollution from tankers and ships, which has been detected as oil spills between 0.01 and 100 km2, follows the marine transit routes. Multi-fractal methods are used to distinguish between natural slicks and spills, in order to estimate the oil spill index in European coastal waters, and in particular, the north-western Mediterranean Sea, which, due to the influence of local winds, shows optimal conditions for oil spill detection.

  8. Interaction between age and perceptual similarity in olfactory discrimination learning in F344 rats: relationships with spatial learning.

    PubMed

    Yoder, Wendy M; Gaynor, Leslie S; Burke, Sara N; Setlow, Barry; Smith, David W; Bizon, Jennifer L

    2017-02-07

    Emerging evidence suggests that aging is associated with a reduced ability to distinguish perceptually similar stimuli in one's environment. As the ability to accurately perceive and encode sensory information is foundational for explicit memory, understanding the neurobiological underpinnings of discrimination impairments that emerge with advancing age could help elucidate the mechanisms of mnemonic decline. To this end, there is a need for preclinical approaches that robustly and reliably model age-associated perceptual discrimination deficits. Taking advantage of rodents' exceptional olfactory abilities, the present study applied rigorous psychophysical techniques to the evaluation of discrimination learning in young and aged F344 rats. Aging did not influence odor detection thresholds or the ability to discriminate between perceptually distinct odorants. In contrast, aged rats were disproportionately impaired relative to young on problems that required discriminations between perceptually similar olfactory stimuli. Importantly, these disproportionate impairments in discrimination learning did not simply reflect a global learning impairment in aged rats, as they performed other types of difficult discriminations on par with young rats. Among aged rats, discrimination deficits were strongly associated with spatial learning deficits. These findings reveal a new, sensitive behavioral approach for elucidating the neural mechanisms of cognitive decline associated with normal aging.

  9. Age Differences in Trade-off Decisions: Different Strategies but Similar Outcomes.

    PubMed

    Ma, Xiaodong; Chen, Yiwei

    2015-06-01

    The primary purpose of this study was to examine age differences in processing strategies of emotionally difficult trade-off decisions. In addition, the study tested the relevant contributions of the cognitive and emotional mechanisms to age differences in processing strategies. Altogether, 40 younger adults and 40 older adults were randomly assigned to either a high or low emotionally difficult condition of a car-purchasing decision task. MouselabWEB software was used to trace participants' processing strategies. Results showed that older adults were more likely to use attribute-based processing strategies, whereas younger adults were more likely to use alternative-based processing strategies in the high-emotion condition. In the low-emotion condition, on the other hand, both younger and older adults preferred to use alternative-based processing strategies. Furthermore, the results suggested that the cognitive measure (i.e., digit symbol coding) was not correlated with the age effects on processing strategies.

  10. Aging in the natural world: comparative data reveal similar mortality patterns across primates.

    PubMed

    Bronikowski, Anne M; Altmann, Jeanne; Brockman, Diane K; Cords, Marina; Fedigan, Linda M; Pusey, Anne; Stoinski, Tara; Morris, William F; Strier, Karen B; Alberts, Susan C

    2011-03-11

    Human senescence patterns-late onset of mortality increase, slow mortality acceleration, and exceptional longevity-are often described as unique in the animal world. Using an individual-based data set from longitudinal studies of wild populations of seven primate species, we show that contrary to assumptions of human uniqueness, human senescence falls within the primate continuum of aging; the tendency for males to have shorter life spans and higher age-specific mortality than females throughout much of adulthood is a common feature in many, but not all, primates; and the aging profiles of primate species do not reflect phylogenetic position. These findings suggest that mortality patterns in primates are shaped by local selective forces rather than phylogenetic history.

  11. Aging in the Natural World: Comparative Data Reveal Similar Mortality Patterns Across Primates

    PubMed Central

    Bronikowski, Anne M.; Altmann, Jeanne; Brockman, Diane K.; Cords, Marina; Fedigan, Linda M.; Pusey, Anne; Stoinski, Tara; Morris, William F.; Strier, Karen B.; Alberts, Susan C.

    2012-01-01

    Human senescence patterns—late onset of mortality increase, slow mortality acceleration, and exceptional longevity—are often described as unique in the animal world. Using an individual-based data set from longitudinal studies of wild populations of seven primate species, we show that contrary to assumptions of human uniqueness, human senescence falls within the primate continuum of aging; the tendency for males to have shorter life spans and higher age-specific mortality than females throughout much of adulthood is a common feature in many, but not all, primates; and the aging profiles of primate species do not reflect phylogenetic position. These findings suggest that mortality patterns in primates are shaped by local selective forces rather than phylogenetic history. PMID:21393544

  12. Spatial distribution of attentional inhibition is not altered in healthy aging

    PubMed Central

    Gayzur, Nora D.; Saville, Alyson L.; Morlock, Shanna L.; Bagne, Angela G.

    2011-01-01

    Inhibition of return (IOR) is a phenomenon of attentional orienting that is indexed by slower responses to targets presented at previously attended locations. The purpose of this study was to examine adult age differences in the distribution of IOR to multiple locations. In three experiments, young adults (ages 18–30 years) and older adults (ages 60–87 years) completed an IOR task that varied in the number of simultaneous onset cues (one to seven) and the number of display locations (four or eight). Analyses were conducted to explore whether IOR patterns were most consistent with limited inhibitory resources, with regional distribution of inhibition, or with vector averaging of cues. The IOR effects were most consistent with vector averaging, such that multiple cues initiated a directional gradient of inhibition centered on the average direction of the cues. The IOR patterns varied minimally with age, consistent with the conclusion that older adults and young adults distributed inhibition in a similar manner. PMID:21264706

  13. Early visual tagging: effects of target-distractor similarity and old age on search, subitization, and counting.

    PubMed

    Watson, Derrick G; Maylor, Elizabeth A; Allen, Gareth E J; Bruce, Lucy A M

    2007-06-01

    Three experiments examined the effects of target-distractor (T-D) similarity and old age on the efficiency of searching for single targets and enumerating multiple targets. Experiment 1 showed that increasing T-D similarity selectively reduced the efficiency of enumerating small (< 4) numerosities (subitizing) but had little effect on enumerating larger numerosities (counting) or searching for a single target. Experiment 2 provided converging evidence using fixation frequencies and a finer range of T-D similarities. Experiment 3 showed that T-D similarity had a greater impact on older than on young adults, but only for subitizing. The data are discussed in terms of the mechanisms and architecture of early visual tagging, dissociable effects in search and enumeration, and the effects of aging on visual processing.

  14. Student and Professor Similarity: Exploring the Effects of Gender and Relative Age

    ERIC Educational Resources Information Center

    Gehrt, Kenneth; Louie, Therese A.; Osland, Asbjorn

    2015-01-01

    The authors examined student responses to faculty traits. Earlier findings revealing a preference for male instructors were obtained before female faculty and students were prevalent on college campuses and may have reflected a male demographic similarity effect. It was hypothesized that students would more favorably evaluate faculty who were…

  15. Child-Parent and Child-Peer Interaction: Observational Similarities and Differences at Age Seven

    ERIC Educational Resources Information Center

    Gerrits, Marleen H.; Goudena, Paul P.; van Aken, Marcel A. G.

    2005-01-01

    According to Russell et al. ("Developmental Rev" 1998; 18: 313) child-parent interaction could contain horizontal qualities, similar to child-peer interactions. To study this, child-parent and child-peer play interactions were compared on several observed horizontal and vertical characteristics in 55 7-year-old children interacting with their…

  16. The Nominal Passover Effect Depends on Addressee Age, Speaker Goal, and Object Similarity

    ERIC Educational Resources Information Center

    Merriman, William E.; Evey, Julie A.

    2005-01-01

    If after teaching a label for 1 object, a speaker does not name a nearby object, 3-year-olds tend to reject the label for the nearby object (W.E. Merriman, J.M. Marazita, L.H. Jarvis, J.A. Evey-Burkey, and M. Biggins, 1995a). In Studies 1 (5-year-olds) and 3 (3-year-olds), this effect depended on object similarity. In Study 2, when a speaker used…

  17. Modeling the brain morphology distribution in the general aging population

    NASA Astrophysics Data System (ADS)

    Huizinga, W.; Poot, D. H. J.; Roshchupkin, G.; Bron, E. E.; Ikram, M. A.; Vernooij, M. W.; Rueckert, D.; Niessen, W. J.; Klein, S.

    2016-03-01

    Both normal aging 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 model changes in brain morphology owing to normal aging. To this end, we developed a method for analyzing and visualizing these changes for the entire brain morphology distribution in the general aging 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 model and 100 were used for testing. The results of the 100 test subjects show that the model generalizes to subjects outside the model population. Smooth percentile curves showing the brain morphology changes as a function of age and spatiotemporal atlases derived from the model population are publicly available via an interactive web application at agingbrain.bigr.nl.

  18. The nominal passover effect depends on addressee age, speaker goal, and object similarity.

    PubMed

    Merriman, William E; Evey, Julie A

    2005-01-01

    If after teaching a label for 1 object, a speaker does not name a nearby object, 3-year-olds tend to reject the label for the nearby object (W.E. Merriman, J.M. Marazita, L.H. Jarvis, J.A. Evey-Burkey, and M. Biggins, 1995a). In Studies 1 (5-year-olds) and 3 (3-year-olds), this effect depended on object similarity. In Study 2, when a speaker used a label without teaching it, 5-year-olds showed no passover effect. 3-year-olds showed none for inanimate objects, but one for animate objects. When extraneous factors that may have promoted animate object individuation were eliminated (Study 3), 3-year-olds showed the effect when a label was taught, but not when it was merely used. Children honor rational restrictions on when the unacceptability of a name can be inferred from its nonoccurrence.

  19. Similarities and life cycle distributions of floras of 22 national parks in the midwestern United States

    USGS Publications Warehouse

    Bennett, James P.

    1996-01-01

    Twenty-two midwestern U.S. national parks were studied to examine the similarities of their floras and analyses of the floras in each national park were used to construct groupings of these smaller sample areas at various similarity levels in order to classify larger floristic areas. The parks were not on average very similar based on Jaccard's similarity index. The maximum average park similarity was 21% (St. Croix National Scenic Riverway), and the maximum park pair similarity was just over 55% for Isle Royale National Park and Pictured Rocks National Lakeshore. The average similarity of parks increased with park area and numbers of native species, and weakly decreased with the percentage of non-native species. Weak trends were observed with latitude and negative trends with longitude. Four park groups were partitioned by cluster analysis of species relative abundance data: 7 prairie parks, 6 northern parks, 4 intermediate parks and 5 southern parks. The average percentage of non-native species was ~33% in the prairie and southern park clusters, while percentage of evergreen perennials was 2 to 4 times greater in the northern parks (8%) compared with other clusters. Deciduous perennials approached 80% in the northern and intermediate park clusters, compared with about 70% for the prairie and southern clusters. Percentage of annuals was almost double in the prairie and southern clusters (average 24%) compared with the northern and intermediate clusters (average 13%).

  20. Distribution of GPs in Scotland by age, gender and deprivation.

    PubMed

    Blane, David N; McLean, Gary; Watt, Graham

    2015-11-01

    General practice in the UK is widely reported to be in crisis, with particular concerns about recruitment and retention of family doctors. This study assessed the distribution of GPs in Scotland by age, gender and deprivation, using routinely available data. We found that there are more GPs (and fewer patients per GP) in the least deprived deciles than there are in the most deprived deciles. Furthermore, there are a higher proportion of older GPs in the most deprived deciles. There are also important gender differences in the distribution of GPs. We discuss the implications of these findings for policymakers and practitioners.

  1. Constrained invariant mass distributions in cascade decays. The shape of the “mqll-threshold” and similar distributions

    NASA Astrophysics Data System (ADS)

    Lester, Christopher G.

    2007-10-01

    Considering the cascade decay D → cC → cbB → cbaA in which D, C, B, A are massive particles and c, b, a are massless particles, we determine for the shape of the distribution of the invariant mass of the three massless particles mabc for the sub-set of decays in which the invariant mass mab of the last two particles in the chain is (optionally) constrained to lie inside an arbitrary interval, mab ∈ [mabcut min, mabcut max]. An example of an experimentally important distribution of this kind is the “mqll threshold”—which is the distribution of the combined invariant mass of the visible Standard Model particles radiated from the hypothesised decay of a squark to the lightest neutralino via successive two body decay: q˜ → qχ˜20 → qll˜ → qllχ˜10, in which the experimenter requires additionally that mll be greater than mllmax /√{ 2}. The location of the “foot” of this distribution is often used to constrain sparticle mass scales. The new results presented here permit the location of this foot to be better understood as the shape of the distribution is derived. The effects of varying the position of the mll cut(s) may now be seen more easily.

  2. Effects of Contextual Similarity and Target-Repetition Proportion on Negative Priming in RT Distributional Analyses

    ERIC Educational Resources Information Center

    Tse, Chi-Shing; Hutchison, Keith A.; Li, Yongna

    2011-01-01

    Participants' reaction time (RT) data in a prime-probe flanker task (e.g., ABA-CAC) were analyzed in terms of the characteristics of RT distribution to examine possible mechanisms that produce negative priming. When the prime and probe were presented in the same context and the proportion of repetition-target trials (TRP) was 0.33, negative…

  3. Distribution system water age can create premise plumbing corrosion hotspots.

    PubMed

    Masters, Sheldon; Parks, Jeffrey; Atassi, Amrou; Edwards, Marc A

    2015-09-01

    Cumulative changes in chemical and biological properties associated with higher "water age" in distribution systems may impact water corrosivity and regulatory compliance with lead and copper action levels. The purpose of this study was to examine the effects of water age and chemistry on corrosivity of various downstream premise plumbing pipe materials and configurations using a combination of controlled laboratory studies and a field survey. Examination of lead pipe, copper pipe with lead solder, and leaded brass materials in a replicated lab rig simulating premise plumbing stagnation events indicated that lead or copper release could increase as much as ∼440 % or decrease as much as 98 % relative to water treatment plant effluent. In field studies at five utilities, trends in lead and copper release were highly dependent on circumstance; for example, lead release increased with water age in 13 % of cases and decreased with water age in 33 % of conditions tested. Levels of copper in the distribution system were up to 50 % lower and as much as 30 % higher relative to levels at the treatment plant. In many cases, high-risks of elevated lead and copper did not co-occur, demonstrating that these contaminants will have to be sampled separately to identify "worst case" conditions for human exposure and monitoring.

  4. Target-distractor similarity has a larger impact on visual search in school-age children than spacing.

    PubMed

    Huurneman, Bianca; Boonstra, F Nienke

    2015-01-22

    In typically developing children, crowding decreases with increasing age. The influence of target-distractor similarity with respect to orientation and element spacing on visual search performance was investigated in 29 school-age children with normal vision (4- to 6-year-olds [N = 16], 7- to 8-year-olds [N = 13]). Children were instructed to search for a target E among distractor Es (feature search: all flanking Es pointing right; conjunction search: flankers in three orientations). Orientation of the target was manipulated in four directions: right (target absent), left (inversed), up, and down (vertical). Spacing was varied in four steps: 0.04°, 0.5°, 1°, and 2°. During feature search, high target-distractor similarity had a stronger impact on performance than spacing: Orientation affected accuracy until spacing was 1°, and spacing only influenced accuracy for identifying inversed targets. Spatial analyses showed that orientation affected oculomotor strategy: Children made more fixations in the "inversed" target area (4.6) than the vertical target areas (1.8 and 1.9). Furthermore, age groups differed in fixation duration: 4- to 6-year-old children showed longer fixation durations than 7- to 8-year-olds at the two largest element spacings (p = 0.039 and p = 0.027). Conjunction search performance was unaffected by spacing. Four conclusions can be drawn from this study: (a) Target-distractor similarity governs visual search performance in school-age children, (b) children make more fixations in target areas when target-distractor similarity is high, (c) 4- to 6-year-olds show longer fixation durations than 7- to 8-year-olds at 1° and 2° element spacing, and (d) spacing affects feature but not conjunction search-a finding that might indicate top-down control ameliorates crowding in children.

  5. Transformation and Self-Similarity Properties of Gamma and Weibull Fragment Size Distributions

    DTIC Science & Technology

    2015-12-01

    Journal of Colloid and Interface Science, 22(2), 126–132, 1966 D. E. Grady and M. E. Kipp, Dynamic Rock Fragmentation, In B. K. Atkinson, Editor...Solutions to Smoluchowski’s Coagulation Equation with Gamma Distributions as Initial Size Spectra, Journal of Colloid and Interface Science, 283, 267...Journal of Colloid and Interface Science, 309, 440- 444, 2007 A. A. Lushnikov, Introduction to Aerosols, In I. Agranovski, Editor, Aerosols

  6. Detecting the presence of two hydrogen bearing fluids through the T2 distribution under circumstances similar

    NASA Astrophysics Data System (ADS)

    Martin, Kathryn

    The use of low field nuclear magnetic resonance is becoming more common as equipment becomes more advanced. There is a rising interest in using low field NMR for various applications like identifying the presence of multiple hydrogen bearing fluids in the near surface. A common way to detect multiple fluid types using NMR is by resolving multiple peaks in the T2 distribution. Certain types of sediments that we might find in the near surface make it difficult to do this. In higher field NMR it is easy to manipulate measurements to suppress the wetting fluid signal which manifests as a separate peak shifted to a lower T 2 time. We can then interpret this peak separation to indicate the presence of multiple hydrogen bearing fluids. One way of manipulating the measurements is to perform the enhanced diffusion method (EDM). It has been suggested that this should be performed with the highest possible gradient, i.e. higher field, to maximize the T2 contrast. However, this has not been explored in lower field settings. Here we begin to look at some of the practical aspects of performing EDM in lower field NMR. We anticipate that performing EDM in a low field will cause a significant decrease in data points. This leads to a loss in resolution in the recovered T 2 distribution so that even though we are efficiently shifting a portion of the recovered T2 we cannot tell when we look at the T2 distribution. For this reason a large part of this work is implementing a Tikhonov inversion algorithm to gain back some resolution in the T2 distribution. We implement the logarithmic barrier method to enforce boundary constraints on the T2 amplitude, and then pick the regularization parameter using the generalized cross validation (GCV) method. In our experience other methods for picking the tradeoff parameter result in over-regularization. We then test this algorithm on EDM data produced using a low field 275 kHz laboratory NMR system. Prior information about the samples used gives us

  7. Deciphering relative timing of fabric development in granitoids with similar absolute ages based on AMS study (Dharwar Craton, South India)

    NASA Astrophysics Data System (ADS)

    Bhatt, Sandeep; Rana, Virendra; Mamtani, Manish A.

    2017-01-01

    Anisotropy of Magnetic Susceptibility (AMS) data are presented from the Koppal Granitoid (Dharwar Craton, South India) that has U-Pb zircon age of 2528 ± 9 Ma. The magnetic fabric is oriented in NNE-SSW direction. This is parallel to the planar structures that developed during regional D3 deformation, but oblique to the NNW-SSE oriented magnetic foliation as well as field foliation (D1/D2 deformation) recorded in the country rock Peninsular Gneiss. Variation in the intensity of fabric within the granitoid is mapped. It is inferred that the emplacement of Koppal Granitoid took place by ballooning and fabric development within the pluton was syntectonic with regional D3. These results are compared with the time-relationship between emplacement/fabric development and regional deformation reported from the Mulgund Granite (2555 ± 6 Ma; U-Pb zircon), which is also located in the Dharwar Craton and is equivalent to the Koppal Granitoid in age. This granite is known to have emplaced syntectonically with regional D1/D2 deformation, and is thus not related to the same deformation event as the Koppal Granitoid, despite their similar absolute ages. It is argued that in the study area, D3 is ≤2537 Ma, while D1/D2 is ≥2549 Ma in age. Thus, this study highlights the use of AMS in (a) deciphering the relative timing of regional deformation and emplacement of granitoids of equivalent age and (b) constraining the timing of regional superposed deformation events.

  8. Are the prevalence and treatment of asthma similar in elite athletes and the aged-matched non-athlete population?

    PubMed

    Locke, S; Marks, G

    2007-12-01

    The objective of this study was to determine the prevalence of asthma and use of asthma medications in elite athletes compared with an age-matched non-athlete population. Data were collected from the respiratory component of annual medical screening of 424 elite athletes from the Queensland Academy of Sport. Measures included the prevalence of current asthma and ever doctor-diagnosed asthma, and the prevalence of use of treatment for asthma including beta-agonists and inhaled corticosteroid medication. The prevalence of current asthma in athletes aged 18-29 years was 14% (95% CI, 9-19%), which did not differ significantly from the prevalence in the non-athlete control population (11%; 95% CI, 9-12%, P=0.3). Of athletes with current asthma, 27% were not taking any medications for asthma, and 25% were treated with short-acting beta-agonist medications alone and were not taking inhaled corticosteroids. These data indicate that the overall cumulative and period prevalence of asthma in Queensland athletes is similar to that in the general age-matched population. Athletes use beta-agonists with a frequency similar to the general population.

  9. Learning of a simple grapho-motor task by young children and adults: similar acquisition but age-dependent retention

    PubMed Central

    Julius, Mona S.; Adi-Japha, Esther

    2015-01-01

    Many new skills are acquired during early childhood. Typical laboratory skill learning tasks are not applicable for developmental studies that involve children younger than 8 years of age. It is not clear whether young children and adults share a basic underlying skill learning mechanism. In the present study, the learning and retention of a simple grapho-motor pattern were studied in three age groups: 5–6, 7–8, and 19–29 years. Each block of the task consists of identical patterns arranged in a spaced writing array. Progression across the block involves on-page movements while producing the pattern, and off-page movements between patterns. The participants practiced the production of the pattern using a digitizing tablet and were tested at 24 h and 2 weeks post-practice. All age groups produced the task blocks more quickly with practice, and the learning rate was inversely related to the initial production time. All groups exhibited additional gains 24 h post-practice that were well-retained 2 weeks later. The accuracy of the participants was maintained throughout the 2-weeks period. These findings suggest that young children and young adults use a similar mechanism when learning the task. Nevertheless, the 6-years-old spent more time off-page during retention testing than when tested at 24 h post-practice, thus supporting the notion that an age advantage may exists in the long-term retention of skills due to planning-dependent aspects. PMID:25798120

  10. Negative strain rate sensitivity in bulk metallic glass and its similarities with the dynamic strain aging effect during deformation

    SciTech Connect

    Dalla Torre, Florian H.; Dubach, Alban; Siegrist, Marco E.; Loeffler, Joerg F.

    2006-08-28

    Detailed investigations were carried out on the deformation behavior of Zr-based monolithic bulk metallic glass and bulk metallic glass matrix composites. The latter, due to splitting and multiplication of shear bands, exhibits larger compressive strains than the former, without significant loss of strength. Serrated flow in conjunction with a negative strain rate sensitivity was observed in both materials. This observation, together with an increase in stress drops with increasing strain and their decrease with increasing strain rate, indicates phenomenologically close similarities with the dynamic strain aging deformation mechanism known for crystalline solids. The micromechanical mechanism of a shear event is discussed in light of these results.

  11. Characteristic age distribution of Plasmodium vivax infections after malaria elimination on Aneityum Island, Vanuatu.

    PubMed

    Kaneko, Akira; Chaves, Luis F; Taleo, George; Kalkoa, Morris; Isozumi, Rie; Wickremasinghe, Renu; Perlmann, Hedvig; Takeo, Satoru; Tsuboi, Takafumi; Tachibana, Shin-ichiro; Kimura, Masatsugu; Björkman, Anders; Troye-Blomberg, Marita; Tanabe, Kazuyuki; Drakeley, Chris

    2014-01-01

    Resurgence is a major concern after malaria elimination. After the initiation of the elimination program on Aneityum Island in 1991, microscopy showed that Plasmodium falciparum disappeared immediately, whereas P. vivax disappeared from 1996 onward, until P. vivax cases were reported in January 2002. By conducting malariometric surveys of the entire population of Aneityum, we investigated the age distribution of individuals with parasites during this epidemic in the context of antimalarial antibody levels and parasite antigen diversity. In July 2002, P. vivax infections were detected by microscopy in 22/759 individuals: 20/298 born after the beginning of the elimination program in 1991, 2/126 born between 1982 and 1991, and none of 335 born before 1982. PCR increased the number of infections detected to 77, distributed among all age groups. Prevalences were 12.1%, 16.7%, and 6.0%, respectively (P < 0.001). In November, a similar age pattern was found, but with fewer infections: 6/746 and 39/741 individuals were found to be infected by microscopy and PCR, respectively. The frequencies of antibody responses to P. vivax were significantly higher in individuals born before 1991 than in younger age groups and were similar to those on Malakula Island, an area of endemicity. Remarkably low antigen diversity (h, 0.15) of P. vivax infections was observed on Aneityum compared with the other islands (h, 0.89 to 1.0). A P. vivax resurgence was observed among children and teenagers on Aneityum, an age distribution similar to those before elimination and on islands where P. vivax is endemic, suggesting that in the absence of significant exposure, immunity may persist, limiting infection levels in adults. The limited parasite gene pool on islands may contribute to this protection.

  12. Effect of river sediment on phosphorus chemistry of similarly aged natural and created wetlands in the Atchafalaya Delta, Louisiana, USA.

    PubMed

    Poach, M E; Faulkner, S P

    2007-01-01

    The goal of wetland creation is to produce an artificial wetland that functions as a natural wetland. Studies comparing created wetlands to similarly aged natural wetlands provide important information about creation techniques and their improvement so as to attain that goal. We hypothesized that differences in sediment phosphorus accretion, deposition, and chemistry between created and natural wetlands in the Atchafalaya Delta, Louisiana, USA were a function of creation technique and natural river processes. Sediment deposition was determined with feldspar marker horizons located in created and natural wetlands belonging to three age classes (<3, 5-10, and 15-20 yr old). Phosphorus fractions were measured in these deposited sediments and in suspended and bedload sediment from the Atchafalaya River. Bedload sediment had significantly lower iron- and aluminum-bound, reductant-soluble, and total phosphorus than suspended sediment due to its high sand percentage. This result indicates that wetlands artificially created in the Atchafalaya Delta using bedload sediment will initially differ from natural wetlands of the same age. Even so, similarities between the mudflat stratum of the <1- to 3-yr-old created wetland and the mudflat stratum of the 15- to 20-yr-old natural wetland support the contention that created wetlands in the Atchafalaya Delta can develop natural characteristics through the deposition of river suspended sediment. Differences between three created wetland strata, the 15- to 20-yr-old willow stratum and the <1- to 3-yr-old willow and mixed marsh strata, and their natural counterparts were linked to design elements of the created wetlands that prevented the direct deposition of the river's suspended sediment.

  13. Effect of river sediment on phosphorus chemistry of similarly aged natural and created wetlands in the Atchafalaya Delta, Louisiana, USA

    USGS Publications Warehouse

    Poach, M.E.; Faulkner, S.P.

    2007-01-01

    The goal of wetland creation is to produce an artificial wetland that functions as a natural wetland. Studies comparing created wetlands to similarly aged natural wetlands provide important information about creation techniques and their improvement so as to attain that goal. We hypothesized that differences in sediment phosphorus accretion, deposition, and chemistry between created and natural wetlands in the Atchafalaya Delta, Louisiana, USA were a function of creation technique and natural river processes. Sediment deposition was determined with feldspar marker horizons located in created and natural wetlands belonging to three age classes (<3, 5-10, and 15-20 yr old). Phosphorus fractions were measured in these deposited sediments and in suspended and bedload sediment from the Atchafalaya River. Bedload sediment had significantly lower iron- and aluminum-bound, reductant-soluble, and total phosphorus than suspended sediment due to its high sand percentage. This result indicates that wetlands artificially created in the Atchafalaya Delta using bedload sediment will initially differ from natural wetlands of the same age. Even so, similarities between the mudflat stratum of the <1- to 3-yr-old created wetland and the mudflat stratum of the 15- to 20-yr-old natural wetland support the contention that created wetlands in the Atchafalaya Delta can develop natural characteristics through the deposition of river suspended sediment. Differences between three created wetland strata, the 15- to 20-yr-old willow stratum and the < 1- to 3-yr-old willow and mixed marsh strata, and their natural counterparts were linked to design elements of the created wetlands that prevented the direct deposition of the river's suspended sediment. ?? ASA, CSSA, SSSA.

  14. Similarities in Gene Expression Profiles during In Vitro Aging of Primary Human Embryonic Lung and Foreskin Fibroblasts.

    PubMed

    Marthandan, Shiva; Priebe, Steffen; Baumgart, Mario; Groth, Marco; Cellerino, Alessandro; Guthke, Reinhard; Hemmerich, Peter; Diekmann, Stephan

    2015-01-01

    Replicative senescence is of fundamental importance for the process of cellular aging, since it is a property of most of our somatic cells. Here, we elucidated this process by comparing gene expression changes, measured by RNA-seq, in fibroblasts originating from two different tissues, embryonic lung (MRC-5) and foreskin (HFF), at five different time points during their transition into senescence. Although the expression patterns of both fibroblast cell lines can be clearly distinguished, the similar differential expression of an ensemble of genes was found to correlate well with their transition into senescence, with only a minority of genes being cell line specific. Clustering-based approaches further revealed common signatures between the cell lines. Investigation of the mRNA expression levels at various time points during the lifespan of either of the fibroblasts resulted in a number of monotonically up- and downregulated genes which clearly showed a novel strong link to aging and senescence related processes which might be functional. In terms of expression profiles of differentially expressed genes with age, common genes identified here have the potential to rule the transition into senescence of embryonic lung and foreskin fibroblasts irrespective of their different cellular origin.

  15. Self-similar clustering distribution of structural features on Ascraeus Mons (Mars): implications for magma chamber depth

    NASA Astrophysics Data System (ADS)

    Pozzobon, R.; Mazzarini, F.; Massironi, M.; Cremonese, G.

    2012-04-01

    The occurrence and spatial distribution of monogenic eruptive structures within volcanic areas are linked to fracture systems and associated stress fields. Moreover, they testify the presence of deep crustal or subcrustal magma reservoirs directly connected to the surface by a percolating fracture network. The correlation between vent distribution and fracture network properties (the so called backbone) can thus be studied in terms of self-similar (fractal) clustering. Self-similarity in vent distribution is described by a power law distribution with fractal exponent D and defined over a range of lengths (l) comprised between a lower limit (lower cutoff, Lco) and an upper limit (upper cutoff, Uco). The upper cutoff (Uco) for fractal clustering was compared with the respective crustal thickness obtained by existing independent geophysical data in the East African Rift System (Mazzarini and Isola, 2010). The computed Ucos for this sector well match the crustal thickness in these volcanic fields. More in detail this computational model verified the strong linear relationship existing between the upper cutoff of the power law distribution and the magma source depth. This method was thus applied to Ascraeus Mons on Mars, which displays basaltic magmatism and hundreds of collapse pits and vents around its flanks, giving a robust statistic to the calculations. Basing on a structural mapping performed on HRSC (High Resolution Stereo Camera onboard the ESA Mars Express mission) at 12 m/px and CTX (Context Camera, Mars Reconnaissance Orbiter mission) at 6 m/px mosaics, more than 2300 collapse pits and vents were analysed. Data analyses displayed a clustering in the structures distribution, showing two distinct populations. The obtained Uco values revealed the presence and the likely depth of both a deep big magma chamber and a small shallower chamber placed below the main caldera. Moreover, the resulting magma source depths are completely consistent and comparable with those

  16. Effects of surface source/sink distributions on the flux-gradient similarity in the unstable surface layer

    NASA Astrophysics Data System (ADS)

    Huo, Qing; Cai, Xuhui; Kang, Ling; Zhang, Hongsheng; Song, Yu

    2015-01-01

    Based on the micrometeorological measurements at a heterogeneous farmland in the North China Plain, this study focused on the effects of surface source/sink distributions on the flux-gradient similarity theory in the unstable surface layer. Firstly, the quality of the micrometeorological measurements was evaluated by the analysis of the surface energy balance closure and the integral turbulence characteristics. In general, a 22 % deficit of energy balance was found at this site, with the sum of sensible and latent heat being smaller than the available energy. The normalized standard deviations of turbulent quantities behaved in accordance with Monin-Obukhov similarity theory. However, slight departures from the classical formulations might be caused by the surface heterogeneity. Then, the applicability of flux-gradient similarity over the heterogeneous surface was examined. The observed normalized wind gradients agreed with the classical universal function established over homogeneous surface. However, due to the effects of surface source/sink distributions, the observed normalized humidity and temperature gradients deviated from the classical universal functions. Our study shows that the classical universal functions, when adjusted by a coefficient considering the effects of surface heterogeneity, can be utilized to estimate fluxes via gradient method even though over the heterogeneous surface. This adjustment coefficient was found to decrease linearly from unity with the increase of the absolute value of the vertical flux divergence.

  17. Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men.

    PubMed

    Mitchell, Cameron J; McGregor, Robin A; D'Souza, Randall F; Thorstensen, Eric B; Markworth, James F; Fanning, Aaron C; Poppitt, Sally D; Cameron-Smith, David

    2015-10-21

    The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring (13)C₆ phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h(-1) in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h(-1) in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein.

  18. Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men

    PubMed Central

    Mitchell, Cameron J.; McGregor, Robin A.; D’Souza, Randall F.; Thorstensen, Eric B.; Markworth, James F.; Fanning, Aaron C.; Poppitt, Sally D.; Cameron-Smith, David

    2015-01-01

    The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring 13C6 phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h−1 in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h−1 in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein. PMID:26506377

  19. Malattia Leventinese/Doyne Honeycomb Retinal Dystrophy: Similarities to Age-Related Macular Degeneration and Potential Therapies.

    PubMed

    Hulleman, John D

    2016-01-01

    Fibulin-3 (F3) is a secreted, disulfide-rich glycoprotein which is expressed in a variety of tissues within the body, including the retina. An Arg345Trp (R345W) mutation in F3 was identified as the cause of a rare retinal dystrophy, Malattia Leventinese/Doyne Honeycomb Retinal Dystrophy (ML/DHRD). ML/DHRD shares many phenotypic similarities with age-related macular degeneration (AMD). The most prominent feature of ML/DHRD is the development of radial or honeycomb patterns of drusen which can develop as early as adolescence. Two independent mouse models of ML/DHRD show evidence of complement activation as well as retinal pigment epithelium (RPE) atrophy, strengthening the phenotypic connection with AMD. Because of its similarities with AMD, ML/DHRD is receiving increasing interest as a potential surrogate disease to study the underpinnings of AMD. This mini-review summarizes the current knowledge of F3 and points toward potential therapeutic strategies which directly or indirectly target cellular dysfunction associated with R345W F3.

  20. Paleodemographic age-at-death distributions of two Mexican skeletal collections: a comparison of transition analysis and traditional aging methods.

    PubMed

    Bullock, Meggan; Márquez, Lourdes; Hernández, Patricia; Ruíz, Fernando

    2013-09-01

    Traditional methods of aging adult skeletons suffer from the problem of age mimicry of the reference collection, as described by Bocquet-Appel and Masset (1982). Transition analysis (Boldsen et al., 2002) is a method of aging adult skeletons that addresses the problem of age mimicry of the reference collection by allowing users to select an appropriate prior probability. In order to evaluate whether transition analysis results in significantly different age estimates for adults, the method was applied to skeletal collections from Postclassic Cholula and Contact-Period Xochimilco. The resulting age-at-death distributions were then compared with age-at-death distributions for the two populations constructed using traditional aging methods. Although the traditional aging methods result in age-at-death distributions with high young adult mortality and few individuals living past the age of 50, the age-at-death distributions constructed using transition analysis indicate that most individuals who lived into adulthood lived past the age of 50.

  1. Tree Age Distributions Reveal Large-Scale Disturbance-Recovery Cycles in Three Tropical Forests.

    PubMed

    Vlam, Mart; van der Sleen, Peter; Groenendijk, Peter; Zuidema, Pieter A

    2016-01-01

    Over the past few decades there has been a growing realization that a large share of apparently 'virgin' or 'old-growth' tropical forests carries a legacy of past natural or anthropogenic disturbances that have a substantial effect on present-day forest composition, structure and dynamics. Yet, direct evidence of such disturbances is scarce and comparisons of disturbance dynamics across regions even more so. Here we present a tree-ring based reconstruction of disturbance histories from three tropical forest sites in Bolivia, Cameroon, and Thailand. We studied temporal patterns in tree regeneration of shade-intolerant tree species, because establishment of these trees is indicative for canopy disturbance. In three large areas (140-300 ha), stem disks and increment cores were collected for a total of 1154 trees (>5 cm diameter) from 12 tree species to estimate the age of every tree. Using these age estimates we produced population age distributions, which were analyzed for evidence of past disturbance. Our approach allowed us to reconstruct patterns of tree establishment over a period of around 250 years. In Bolivia, we found continuous regeneration rates of three species and a peaked age distribution of a long-lived pioneer species. In both Cameroon and Thailand we found irregular age distributions, indicating strongly reduced regeneration rates over a period of 10-60 years. Past fires, windthrow events or anthropogenic disturbances all provide plausible explanations for the reported variation in tree age across the three sites. Our results support the recent idea that the long-term dynamics of tropical forests are impacted by large-scale disturbance-recovery cycles, similar to those driving temperate forest dynamics.

  2. Tree Age Distributions Reveal Large-Scale Disturbance-Recovery Cycles in Three Tropical Forests

    PubMed Central

    Vlam, Mart; van der Sleen, Peter; Groenendijk, Peter; Zuidema, Pieter A.

    2017-01-01

    Over the past few decades there has been a growing realization that a large share of apparently ‘virgin’ or ‘old-growth’ tropical forests carries a legacy of past natural or anthropogenic disturbances that have a substantial effect on present-day forest composition, structure and dynamics. Yet, direct evidence of such disturbances is scarce and comparisons of disturbance dynamics across regions even more so. Here we present a tree-ring based reconstruction of disturbance histories from three tropical forest sites in Bolivia, Cameroon, and Thailand. We studied temporal patterns in tree regeneration of shade-intolerant tree species, because establishment of these trees is indicative for canopy disturbance. In three large areas (140–300 ha), stem disks and increment cores were collected for a total of 1154 trees (>5 cm diameter) from 12 tree species to estimate the age of every tree. Using these age estimates we produced population age distributions, which were analyzed for evidence of past disturbance. Our approach allowed us to reconstruct patterns of tree establishment over a period of around 250 years. In Bolivia, we found continuous regeneration rates of three species and a peaked age distribution of a long-lived pioneer species. In both Cameroon and Thailand we found irregular age distributions, indicating strongly reduced regeneration rates over a period of 10–60 years. Past fires, windthrow events or anthropogenic disturbances all provide plausible explanations for the reported variation in tree age across the three sites. Our results support the recent idea that the long-term dynamics of tropical forests are impacted by large-scale disturbance-recovery cycles, similar to those driving temperate forest dynamics. PMID:28105034

  3. Aged boreal biomass-burning aerosol size distributions from BORTAS 2011

    NASA Astrophysics Data System (ADS)

    Sakamoto, K. M.; Allan, J. D.; Coe, H.; Taylor, J. W.; Duck, T. J.; Pierce, J. R.

    2015-02-01

    Biomass-burning aerosols contribute to aerosol radiative forcing on the climate system. The magnitude of this effect is partially determined by aerosol size distributions, which are functions of source fire characteristics (e.g. fuel type, MCE) and in-plume microphysical processing. The uncertainties in biomass-burning emission number-size distributions in climate model inventories lead to uncertainties in the CCN (cloud condensation nuclei) concentrations and forcing estimates derived from these models. The BORTAS-B (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellite) measurement campaign was designed to sample boreal biomass-burning outflow over eastern Canada in the summer of 2011. Using these BORTAS-B data, we implement plume criteria to isolate the characteristic size distribution of aged biomass-burning emissions (aged ~ 1-2 days) from boreal wildfires in northwestern Ontario. The composite median size distribution yields a single dominant accumulation mode with Dpm = 230 nm (number-median diameter) and σ = 1.5, which are comparable to literature values of other aged plumes of a similar type. The organic aerosol enhancement ratios (ΔOA / ΔCO) along the path of Flight b622 show values of 0.09-0.17 μg m-3 ppbv-1 (parts per billion by volume) with no significant trend with distance from the source. This lack of enhancement ratio increase/decrease with distance suggests no detectable net OA (organic aerosol) production/evaporation within the aged plume over the sampling period (plume age: 1-2 days), though it does not preclude OA production/loss at earlier stages. A Lagrangian microphysical model was used to determine an estimate of the freshly emitted size distribution corresponding to the BORTAS-B aged size distributions. The model was restricted to coagulation and dilution processes based on the insignificant net OA production/evaporation derived from the ΔOA / ΔCO enhancement ratios. We

  4. Martian channels and valleys - Their characteristics, distribution, and age

    NASA Technical Reports Server (NTRS)

    Carr, M. H.; Clow, G. D.

    1981-01-01

    The distribution and ages of Martian channels and valleys, which are generally believed to have been cut by running water, are examined with particular emphasis on the small branching networks referred to as runoff channels or valley networks. Valleys at latitudes from 65 deg S to 65 deg N were surveyed on Viking images at resolutions between 125 and 300 m. Almost all of the valleys are found in the old cratered terrain, in areas characterized by high elevations, low albedos and low violet/red ratios. The networks are deduced to have formed early in the history of the planet, with a formation rate declining rapidly shortly after the decline of the cratering rate 3.9 billion years ago. Two types of outflow channels are distinguished: unconfined, in which broad swaths of terrain are scoured, and confined, in which flow is restricted to discrete channels. Both types start at local sources, and have formed episodically throughout Martian history. Fretted channels, found mainly in two latitude belts characterized by relatively rapid erosion along escarpments, are explained by the lateral enlargement of other channels by mass wasting.

  5. Distribution of counterions and interaction between two similarly charged dielectric slabs: roles of charge discreteness and dielectric inhomogeneity.

    PubMed

    Pezeshkian, Weria; Nikoofard, Narges; Norouzi, Davood; Mohammad-Rafiee, Farshid; Fazli, Hossein

    2012-06-01

    The distribution of counterions and the electrostatic interaction between two similarly charged dielectric slabs is studied in the strong coupling limit. Dielectric inhomogeneities and discreteness of charge on the slabs have been taken into account. It is found that the amount of dielectric constant difference between the slabs and the environment, and the discreteness of charge on the slabs have opposing effects on the equilibrium distribution of the counterions. At small interslab separations, increasing the amount of dielectric constant difference increases the tendency of the counterions toward the middle of the intersurface space between the slabs and the discreteness of charge pushes them to the surfaces of the slabs. In the limit of point charges, independent of the strength of dielectric inhomogeneity, counterions distribute near the surfaces of the slabs. The interaction between the slabs is attractive at low temperatures and its strength increases with the dielectric constant difference. At room temperature, the slabs may completely attract each other, reach to an equilibrium separation, or have two equilibrium separations with a barrier in between, depending on the system parameters.

  6. Internal calibration of a distributed hydrological model using satellite data of land surface temperature similarly to ground discharge measurements

    NASA Astrophysics Data System (ADS)

    Corbari, C.; Ravazzani, G.; Mancini, M.; Li, J.; Su, B.

    2012-04-01

    This study proposes a new methodology for the calibration of distributed hydrological models at basin scale through the constraints on an internal model variable using remote sensing data of land surface temperature. The model algorithm solves the system of energy and mass balances in term of the equilibrium pixel temperature or representative equilibrium temperature that governs the fluxes of energy and mass over the basin domain. This equilibrium surface temperature, which is a critical model state variable, is compared to land surface temperature from MODIS. So soil hydraulic parameters and vegetation variables will be calibrated according to the comparison between observed and simulated land surface temperature minimizing the errors. A similar procedure will also be applied performing the traditional calibration using only discharge measurements. The distributed energy water balance model, Flash-flood Event-based Spatially-distributed rainfall-runoff Transformation - Energy Water Balance model (FEST-EWB), will be used to test this approach for the Upper Yangtze River basin (China). This work was supported in the framework of the Dragon 2 Programme between the European Space Agency (ESA) together with the National Remote Sensing Centre of China (NRSCC).

  7. Sex and age differences in mercury distribution and excretion in methylmercury-administered mice

    SciTech Connect

    Hirayama, K.; Yasutake, A.

    1986-01-01

    Sex differences in mercury distribution and excretion after single administration of methylmercury chloride (MMC, 5 mg/kg were studied in mice. A sex difference in urinary mercury excretion was found in sexually mature mice (age of 7 wk) of C57BL/6N and BALB/cA strains. Males showed higher mercury levels in urine than females, though no significant difference was found in fecal mercury levels 24 h post exposure to MMC. The higher urinary excretion rates in males accounted for significant lowering of mercury levels in the brain, liver, and blood, but not in the kidney, which showed higher values. At 5 min, however, the sex difference was found only in the kidney, showing higher levels in males. Changes in mercury distribution with time were studied in C57BL/6N mice. The brain mercury increased in both sexes up to 3 d, and decreased only in males on d 5. Liver and blood mercury decreased with time in both sexes, and these were constantly higher in females than in males. Renal mercury in males decreased to similar levels to females on d 3. The sex differences at various ages were studied with C57BL/6N mice 24 h after dosing. Two-week-old mice did not show significant sex differences in the mercury distribution and excretion, and their urinary mercury levels were much lower as compared to the older mice. Urinary mercury excretion in both sexes increased at 4 wk of age and then decreased at 45 wk of age. At 4, 7, 10, and 45 wk of age, males showed higher urinary mercury levels than females. From these findings, it has been suggested that urinary mercury excretion may be related to sex hormones, especially androgens.

  8. Conformational distributions of denatured and unstructured proteins are similar to those of 20 × 20 blocked dipeptides.

    PubMed

    Oh, Kwang-Im; Jung, Young-Sang; Hwang, Geum-Sook; Cho, Minhaeng

    2012-05-01

    Understanding intrinsic conformational preferences of amino-acids in unfolded proteins is important for elucidating the underlying principles of their stability and re-folding on biological timescales. Here, to investigate the neighbor interaction effects on the conformational propensities of amino-acids, we carried out (1)H NMR experiments for a comprehensive set of blocked dipeptides and measured the scalar coupling constants between alpha protons and amide protons as well as their chemical shifts. Detailed inspection of these NMR properties shows that, irrespective of amino-acid side-chain properties, the distributions of the measured coupling constants and chemical shifts of the dipeptides are comparatively narrow, indicating small variances of their conformation distributions. They are further compared with those of blocked amino-acids (Ac-X-NHMe), oligopeptides (Ac-GGXGG-NH(2)), and native (lysozyme), denatured (lysozyme and outer membrane protein X from Escherichia coli), unstructured (Domain 2 of the protein 5A of Hepatitis C virus), and intrinsically disordered (hNlg3cyt: intracellular domain of human NL3) proteins. These comparative investigations suggest that the conformational preferences and local solvation environments of the blocked dipeptides are quite similar to not only those of other short oligopeptides but also those of denatured and natively unfolded proteins.

  9. Age distribution patterns of human gene families: divergent for Gene Ontology categories and concordant between different subcellular localizations.

    PubMed

    Liu, Gangbiao; Zou, Yangyun; Cheng, Qiqun; Zeng, Yanwu; Gu, Xun; Su, Zhixi

    2014-04-01

    The age distribution of gene duplication events within the human genome exhibits two waves of duplications along with an ancient component. However, because of functional constraint differences, genes in different functional categories might show dissimilar retention patterns after duplication. It is known that genes in some functional categories are highly duplicated in the early stage of vertebrate evolution. However, the correlations of the age distribution pattern of gene duplication between the different functional categories are still unknown. To investigate this issue, we developed a robust pipeline to date the gene duplication events in the human genome. We successfully estimated about three-quarters of the duplication events within the human genome, along with the age distribution pattern in each Gene Ontology (GO) slim category. We found that some GO slim categories show different distribution patterns when compared to the whole genome. Further hierarchical clustering of the GO slim functional categories enabled grouping into two main clusters. We found that human genes located in the duplicated copy number variant regions, whose duplicate genes have not been fixed in the human population, were mainly enriched in the groups with a high proportion of recently duplicated genes. Moreover, we used a phylogenetic tree-based method to date the age of duplications in three signaling-related gene superfamilies: transcription factors, protein kinases and G-protein coupled receptors. These superfamilies were expressed in different subcellular localizations. They showed a similar age distribution as the signaling-related GO slim categories. We also compared the differences between the age distributions of gene duplications in multiple subcellular localizations. We found that the distribution patterns of the major subcellular localizations were similar to that of the whole genome. This study revealed the whole picture of the evolution patterns of gene functional

  10. Mean age distribution of inorganic soil-nitrogen

    NASA Astrophysics Data System (ADS)

    Woo, Dong K.; Kumar, Praveen

    2016-07-01

    Excess reactive nitrogen in soils of intensively managed landscapes causes adverse environmental impact, and continues to remain a global concern. Many novel strategies have been developed to provide better management practices and, yet, the problem remains unresolved. The objective of this study is to develop a model to characterize the "age" of inorganic soil-nitrogen (nitrate, and ammonia/ammonium). We use the general theory of age, which provides an assessment of the time elapsed since inorganic nitrogen has been introduced into the soil system. We analyze a corn-corn-soybean rotation, common in the Midwest United States, as an example application. We observe two counter-intuitive results: (1) the mean nitrogen age in the topsoil layer is relatively high; and (2) mean nitrogen age is lower under soybean cultivation compared to corn although no fertilizer is applied for soybean cultivation. The first result can be explained by cation-exchange of ammonium that retards the leaching of nitrogen, resulting in an increase in the mean nitrogen age near the soil surface. The second result arises because the soybean utilizes the nitrogen fertilizer left from the previous year, thereby removing the older nitrogen and reducing mean nitrogen age. Estimating the mean nitrogen age can thus serve as an important tool to disentangle complex nitrogen dynamics by providing a nuanced characterization of the time scales of soil-nitrogen transformation and transport processes.

  11. Clusters and cycles in the cosmic ray age distributions of meteorites

    NASA Technical Reports Server (NTRS)

    Woodard, M. F.; Marti, K.

    1985-01-01

    Statistically significant clusters in the cosmic ray exposure age distributions of some groups of iron and stone meteorites were observed, suggesting epochs of enhanced collision and breakups. Fourier analyses of the age distributions of chondrites reveal no significant periods, nor does the same analysis when applied to iron meteorite clusters.

  12. Association between obesity and femoral neck strength according to age, sex, and fat distribution.

    PubMed

    Kim, H; Lee, S H; Kim, B J; Koh, J M

    2017-03-29

    Indicators of total and abdominal obesity were negatively associated with femoral neck strength indices. There are age-, sex-, and fat distribution-specific differences in the magnitude of these associations. These suggested that indicators of obesity with different magnitude according to age, sex, and fat distribution associated with poor bone health.

  13. Child-Child Similarity on Attachment and Temperament as Predictors of Positive Interaction during Acquaintanceship at Age 3

    ERIC Educational Resources Information Center

    McElwain, Nancy L.; Ogolsky, Brian G.; Engle, Jennifer M.; Holland, Ashley S.; Mitchell, Elissa Thomann

    2016-01-01

    Child-child similarity on attachment and temperament were examined, in turn, as predictors of interaction quality between previously unacquainted children. At 33 months, child-mother attachment security was assessed, and parents reported on child temperament. At 39 months, 114 children were randomly paired into 57 same-sex dyads and observed…

  14. Further Evidence on the Relation Between Age of Separation and Similarity in IQ Among Pairs of Separated Identical Twins.

    ERIC Educational Resources Information Center

    Vandenberg, Steven G.; Johnson, Ronald C.

    Ronald C. Johnson argued that if early environmental stimulation or deprivation has a significant effect on intellectual ability, then individuals who are genetically identical and who are exposed to a common early environment should resemble one another more closely in IQ than similar individuals who have not shared a common environment. Johnson…

  15. Deficiency and supplementation of PUFA in the diet have similar effects on the age-associated changes in rat-plasma cholesterol levels.

    PubMed

    Straniero, Sara; Cavallini, Gabriella; Donati, Alessio; Metelli, Maria Rita; Tamburini, Ilaria; Pietrini, Pietro; Bergamini, Ettore

    2008-12-01

    Levels of plasma cholesterol, particularly LDL cholesterol, increase with increasing age in humans and rodents. Feeding a fish oil-rich diet may exert hypocholesterolemic effects. The aim of this work was to examine the effects of a life-long administration of a PUFA-enriched diet and of a PUFA-deficient diet in male Sprague-Dawley rats on the age-associated increases in plasma cholesterol and triglycerides. Diet had small effects on body-weight, and had dramatic effects on liver phospholipids-fatty acids. Surprisingly, both diets counteracted the age-associated changes in plasma cholesterol and triglycerides similarly and benefits were already visible in adult rats.

  16. Biomarkers of vascular function in premenopausal and recent postmenopausal women of similar age: effect of exercise training.

    PubMed

    Nyberg, Michael; Seidelin, Kaare; Andersen, Thomas Rostgaard; Overby, Nickie Neumann; Hellsten, Ylva; Bangsbo, Jens

    2014-04-01

    Menopause is associated with an accelerated decline in vascular function; however, whether this is an effect of age and/or menopause and how exercise training may affect this decline remains unclear. We examined a range of molecular measures related to vascular function in matched premenopausal and postmenopausal women before and after 12 wk of exercise training. Thirteen premenopausal and 10 recently postmenopausal [1.6 ± 0.3 (means ± SE) years after final menstrual period] women only separated by 3 yr (48 ± 1 vs. 51 ± 1 yr) were included. Before training, diastolic blood pressure, soluble intercellular adhesion molecule-1 (sICAM-1), and skeletal muscle expression of thromboxane A synthase were higher in the postmenopausal women compared with the premenopausal women, all indicative of impaired vascular function. In both groups, exercise training lowered diastolic blood pressure, the levels of sICAM-1, soluble vascular adhesion molecule-1 (sVCAM-1), as well as plasma and skeletal muscle endothelin-1. The vasodilator prostacyclin tended (P = 0.061) to be higher in plasma with training in the postmenopausal women only. These findings demonstrate that already within the first years after menopause, several biomarkers of vascular function are adversely altered, indicating that these biomarker changes are more related to hormonal changes than aging. Exercise training appears to have a positive impact on vascular function, as indicated by a marked improvement in the biomarker profile, in both premenopausal and postmenopausal women.

  17. Mathematical results new and revisited on the distribution of groundwater age

    NASA Astrophysics Data System (ADS)

    Ginn, T. R.; Massoudieh, A.; Foglia, L.

    2009-12-01

    The equation governing the distribution of groundwater age under transient, 3D flow conditions is analyzed under several simplifying cases to illustrate some relations among groundwater age equations and some results about steady-state and transient age distributions. First linkages are made among the various groundwater age equations recently published, showing them all to be different simplifications of the same equation. The most basic analysis in 1D shows that groundwater age is at lease inverse-Gaussian distributed. More generally, steady state age moments, when they exist, are given by breakthrough curve moments and this allows us to use the temporal moment results from the solute transport literature as steady state age moments. In particular, age moment equations with arbitrary diffusive mass transfer (two-domain, radial microscopic, powerlaw) at steady state are already available as the temporal flux moment equations for solute transport under analogous boundary conditions. Lastly transient simulations of age in 1D are calculated to illustrate several aspects of the evolution of groundwater age distributions in time in the presences of multidomain diffusive transport.

  18. The Aging Teaching Workforce: A Snapshot. Age Distribution of Public School Teachers, by State, 2003-2004

    ERIC Educational Resources Information Center

    Ingersoll, Richard

    2009-01-01

    This analysis on the age distribution of public school teachers have been prepared by Dr. Richard Ingersoll for the National Commission on Teaching and America's Future (NCTAF), using data gathered through the U.S. Department of Education's Schools and Staffing Survey (SASS), which is administered every four years. The data for this analysis are…

  19. Similar immunogenicity of measles-mumps-rubella (MMR) vaccine administrated at 8 months versus 12 months age in children.

    PubMed

    He, Hanqing; Chen, Enfu; Chen, Haiping; Wang, Zhifang; Li, Qian; Yan, Rui; Guo, Jing; Zhou, Yang; Pan, Jinren; Xie, Shuyun

    2014-06-30

    Two doses of measles-mumps-rubella (MMR) strategy has been recommended by World Health Organization and is also widely adopted in many countries. In order to provide the evidence for perfecting the immunization strategy of MMR, this study evaluated the safety and immunogenicity of MMR with different two-dose schedule in infants. 280 participants were enrolled and randomly allocated to Group 1 (first dose at 8 months) or Group 2 (first dose at 12 months), and both groups administered the second dose at 10 months later. Solicited local and general symptoms after each vaccination with MMR were mild and infrequent in all participants of two groups. After administration of the first dose of MMR, seropositive rates were 100% in both groups for measles, 89.3% in Group 1 and 87.1% in Group 2 for mumps (P=0.578), 92.0% in Group 1 and 92.9% in Group 2 (P=0.393). The seropositive rates of mumps decreased significantly (from >86% to <65%) both in two groups (P<0.001) 10 months after the first dose of MMR, but no significant change was found in measles and rubella. All children get the positive titer for three vaccines in two groups after given the second dose MMR, higher seroconversion rate was found for mumps both in two groups (71.7% vs 77.2%, P=0.370). In conclusion, this study indicated that the MMR was well tolerated and immunogenic against measles, mumps and rubella with schedule of first dose both at 8 months and 12 months age. Our findings strongly supported that two doses of MMR can be introduced by replacing the first dose of MR in current EPI with MMR at 8 months age and the second dose at 18 months in China.

  20. [Distribution of the different patterns of aging over the system of animal world].

    PubMed

    Popov, I Iu

    2011-01-01

    Since the system of animal world reflects evolutionary trends, an analysis of distribution of patterns of aging over this system provides information on the causes of the formation of differences among them. In this paper the system of the main animal groups in form of a table is presented, and the distribution of patterns demonstrating minimum and maximum of aging is discussed. Meanwhile the colonial animals are considered as a "minimum of aging", the animals demonstrating drastic self-liquidation after reproduction are considered as a "maximum of aging" (the most well-known example is the pink salmon). It is shown, that as far as the degree of difference from the simplest ancestor increases in process of evolution, the increase of the manifestations of aging takes place. Slow aging of relatively simple organisms cannot be a direct source of measures to prevent aging of complex ones.

  1. Martian channels and valleys: Their characteristics, distribution, and age

    USGS Publications Warehouse

    Carr, M.H.; Clow, G.D.

    1981-01-01

    All Martian channels and valleys visible at a resolution of 125 to 300 meters between 65??N and 65??S were mapped at a scale of 1:5,000,000 and the maps then digitized. Correlations of valley presence with other surface features show that almost all valleys are in the old cratered terrain. preferentially in areas of low albedo, low violet/red ratios, and high elevation. The networks are open, the individual drainage basins are small relative to Earth, and large distances separate the basins, features which all suggest an immature drainage system. The simplest explanation of the correlations and the restriction of valley networks to old terrain is that the channels themselves are old, and that the climatic conditions necessary for their formation did not prevail for long after the decline in the cratering rate around 3.9 billion years ago. Two types of outflow channel are distinguished: unconfined, in which broad swaths of terrain are scoured, and confined, in which flow is restricted to discrete channels. The outflow channels have a wide range of ages and may form under present climatic conditions. Fretted channels are largely restrited to two latitude belts centered on 40??N and 45??S, where relatively rapid erosion along escarpments results from mass wasting. They probably form by enlargement of preexisting channels by escarpment retreat. ?? 1981.

  2. Paleoclimate Signals and Age Distributions from 41 Public Water Works in the Netherlands

    NASA Astrophysics Data System (ADS)

    Broers, H. P.; Weert, J. D.; Sültenfuß, J.; Aeschbach, W.; Vonhof, H.; Casteleijns, J.

    2015-12-01

    Knowing the age distribution of water abstracted from public water supply wells is of prime importance to ensure customer trust and to underpin predictions of water quality evolution in time. Especially, age distributions enable the assessment of the vulnerability of well fields, both in relation to surface sources of contamination as in relation to subsurface sources, such as possibly related to shale gas extraction. We sampled the raw water of 41 large public supply well fields which represents a mixture of groundwaters and used the a discrete travel time distribution model (DTTDM, Visser et al. 2013, WRR) in order to quantify the age distribution of the mixture. Measurements included major ion chemistry, 3H, 3He, 4He, 18O, 2H, 14C, 13CDIC and 13CCH4 and the full range of noble gases. The heavier noble gases enable the calculation of the Noble Gas Temperature (NGT) which characterizes the temperature of past recharge conditions. The 14C apparent age of each mixture was derived correcting for dead carbon sources. The DTTDM used the 3H and 4He concentrations, the 14C apparent age and the NGT as the four distinctive tracers to estimate the age distributions. Especially 4He and NGT provide extra information on the older part of the age distributions and showed that the 14C apparent ages are often the result of mixing of waters ranging between 2.000 and 35.000 years old, instead of being discrete ages with a limited .variance as sometimes assumed.The results show a large range of age distributions, comprising vulnerable well fields with >60% young water (< 100 yrs) and well-protected well fields with >85% very old groundwater (> 25 kyrs) and all forms of TTD's in between. The age distributions are well in correspondence with the hydrogeological setting of the well fields; all well fields with an age distribution skewed towards older ages are in the Roer Valley Graben structure, where fluvial and marine aquitards provide protection from recent recharge. Especially

  3. Paleoclimate signals and age distributions from 41 public water works in the Netherlands

    NASA Astrophysics Data System (ADS)

    Broers, Hans Peter; de Weert, Jasperien; Sueltenfuss, Juergen; Aeschbach-Hertig, Werner; Vonhof, Hubert; Casteleijns, Jeroen

    2015-04-01

    Knowing the age distribution of water abstracted from public water supply wells is of prime importance to ensure customer trust and to underpin predictions of water quality evolution in time. Especially, age distributions enable the assessment of the vulnerability of well fields, both in relation to surface sources of contamination as in relation to subsurface sources, such as possibly related to shale gas extraction. We sampled the raw water of 41 large public supply well fields which represents a mixture of groundwaters and used the a discrete travel time distribution model (DTTDM, Visser et al. 2013, WRR) in order to quantify the age distribution of the mixture. Measurements included major ion chemistry, 3H, 3He, 4He, 18O, 2H, 14C, 13CDIC and 13CCH4 and the full range of noble gases. The heavier noble gases enable the calculation of the Noble Gas Temperature (NGT) which characterizes the temperature of past recharge conditions. The 14C apparent age of each mixture was derived correcting for dead carbon sources and included carbonate dissolution and methanogenesis as the defining processes. The DTTDM used the 3H and 4He concentrations, the 14C apparent age and the NGT as the four distinctive tracers to estimate the age distributions. The use of 18O was less effective because the processes that led to more enriched values are too uncertain . Especially 4He and NGT provide extra information on the older part of the age distributions and showed that the 14C apparent ages are often the result of mixing of waters ranging between 2.000 and 35.000 years old, instead of being discrete ages with a limited .variance as sometimes assumed. The results show a large range of age distributions, comprising vulnerable well fields with >60% young water (< 100 yrs) and well-protected well fields with >85% very old groundwater (> 25 kyrs) and all forms of TTD's in between. The age distributions are well in correspondence with the hydrogeological setting of the well fields; all well

  4. Older age is associated with greater central aortic blood pressure following the exercise stress test in subjects with similar brachial systolic blood pressure.

    PubMed

    Kobayashi, Masatake; Oshima, Kazutaka; Iwasaki, Yoichi; Kumai, Yuto; Avolio, Alberto; Yamashina, Akira; Takazawa, Kenji

    2016-08-01

    Brachial systolic pressure (BSP) is often monitored during exercise by the stress test; however, central systolic pressure (CSP) is thought to be a more direct measure of cardiovascular events. Although some studies reported that exercise and aging may play roles in changes of both BSP and CSP, the relationship between BSP and CSP with age following the exercise stress test remains unclear. The aim of this study was to evaluate the effect of age on the relationship between BSP and CSP measured after exercise. Ninety-six subjects underwent the diagnostic treadmill exercise stress test, and we retrospectively divided them into the following 3 groups by age: the younger age group (43 ± 4 years), middle age group (58 ± 4 years), and older age group (70 ± 4 years). Subjects exercised according to the Bruce protocol, to achieve 85 % of their age-predicted maximum heart rate or until the appearance of exercise-associated symptoms. BSP, CSP, and pulse rate (PR) were measured using a HEM-9000AI (Omron Healthcare, Japan) at rest and after exercise. BSP, CSP, and PR at rest were not significantly different among the 3 groups (p = 0.92, 0.21, and 0.99, respectively). BSP and PR immediately after exercise were not significantly different among the groups (p = 0.70 and 0.38, respectively). However, CSP immediately after exercise was 144 ± 18 mmHg (younger age), 149 ± 17 mmHg (middle age), and 158 ± 19 mmHg (older age). CSP in the older age group was significantly higher than that in the younger age group (p < 0.01). Despite similar BSPs in all age groups after exercise, CSP was higher in the older age group. Therefore, older subjects have a higher CSP after exercise, which is not readily assessed by conventional measurements of BSP.

  5. Comparison of particle-tracking and lumped-parameter age-distribution models for evaluating vulnerability of production wells to contamination

    NASA Astrophysics Data System (ADS)

    Eberts, S. M.; Böhlke, J. K.; Kauffman, L. J.; Jurgens, B. C.

    2012-03-01

    Environmental age tracers have been used in various ways to help assess vulnerability of drinking-water production wells to contamination. The most appropriate approach will depend on the information that is available and that which is desired. To understand how the well will respond to changing nonpoint-source contaminant inputs at the water table, some representation of the distribution of groundwater ages in the well is needed. Such information for production wells is sparse and difficult to obtain, especially in areas lacking detailed field studies. In this study, age distributions derived from detailed groundwater-flow models with advective particle tracking were compared with those generated from lumped-parameter models to examine conditions in which estimates from simpler, less resource-intensive lumped-parameter models could be used in place of estimates from particle-tracking models. In each of four contrasting hydrogeologic settings in the USA, particle-tracking and lumped-parameter models yielded roughly similar age distributions and largely indistinguishable contaminant trends when based on similar conceptual models and calibrated to similar tracer data. Although model calibrations and predictions were variably affected by tracer limitations and conceptual ambiguities, results illustrated the importance of full age distributions, rather than apparent tracer ages or model mean ages, for trend analysis and forecasting.

  6. Comparison of particle-tracking and lumped-parameter age-distribution models for evaluating vulnerability of production wells to contamination

    USGS Publications Warehouse

    Eberts, S.M.; Böhlke, J.K.; Kauffman, L.J.; Jurgens, B.C.

    2012-01-01

    Environmental age tracers have been used in various ways to help assess vulnerability of drinking-water production wells to contamination. The most appropriate approach will depend on the information that is available and that which is desired. To understand how the well will respond to changing nonpoint-source contaminant inputs at the water table, some representation of the distribution of groundwater ages in the well is needed. Such information for production wells is sparse and difficult to obtain, especially in areas lacking detailed field studies. In this study, age distributions derived from detailed groundwater-flow models with advective particle tracking were compared with those generated from lumped-parameter models to examine conditions in which estimates from simpler, less resource-intensive lumped-parameter models could be used in place of estimates from particle-tracking models. In each of four contrasting hydrogeologic settings in the USA, particle-tracking and lumped-parameter models yielded roughly similar age distributions and largely indistinguishable contaminant trends when based on similar conceptual models and calibrated to similar tracer data. Although model calibrations and predictions were variably affected by tracer limitations and conceptual ambiguities, results illustrated the importance of full age distributions, rather than apparent tracer ages or model mean ages, for trend analysis and forecasting.

  7. Investigating the age distribution of fracture discharge using multiple environmental tracers, Bedrichov Tunnel, Czech Republic

    SciTech Connect

    Gardner, W. Payton; Hokr, Milan; Shao, Hua; Balvin, Ales; Kunz, Herbert; Wang, Yifeng

    2016-10-19

    We investigated the transit time distribution (TTD) of discharge collected from fractures in the Bedrichov Tunnel, Czech Republic, using lumped parameter models and multiple environmental tracers. We then utilize time series of δ18O, δ2H and 3H along with CFC measurements from individual fractures in the Bedrichov Tunnel of the Czech Republic to investigate the TTD, and the uncertainty in estimated mean travel time in several fracture networks of varying length and discharge. We also compare several TTDs, including the dispersion distribution, the exponential distribution, and a developed TTD which includes the effects of matrix diffusion. The effect of seasonal recharge is explored by comparing several seasonal weighting functions to derive the historical recharge concentration. We identify best fit mean ages for each TTD by minimizing the error-weighted, multi-tracer χ2 residual for each seasonal weighting function. We use this methodology to test the ability of each TTD and seasonal input function to fit the observed tracer concentrations, and the effect of choosing different TTD and seasonal recharge functions on the mean age estimation. We find that the estimated mean transit time is a function of both the assumed TTD and seasonal weighting function. Best fits as measured by the χ2 value were achieved for the dispersion model using the seasonal input function developed here for two of the three modeled sites, while at the third site, equally good fits were achieved with the exponential model and the dispersion model and our seasonal input function. The average mean transit time for all TTDs and seasonal input functions converged to similar values at each location. The sensitivity of the estimated mean transit time to the seasonal weighting function was equal to that of the TTD. These results indicated that understanding seasonality of recharge is at least as important as the uncertainty in the flow path distribution in

  8. Investigating the age distribution of fracture discharge using multiple environmental tracers, Bedrichov Tunnel, Czech Republic

    DOE PAGES

    Gardner, W. Payton; Hokr, Milan; Shao, Hua; ...

    2016-10-19

    We investigated the transit time distribution (TTD) of discharge collected from fractures in the Bedrichov Tunnel, Czech Republic, using lumped parameter models and multiple environmental tracers. We then utilize time series of δ18O, δ2H and 3H along with CFC measurements from individual fractures in the Bedrichov Tunnel of the Czech Republic to investigate the TTD, and the uncertainty in estimated mean travel time in several fracture networks of varying length and discharge. We also compare several TTDs, including the dispersion distribution, the exponential distribution, and a developed TTD which includes the effects of matrix diffusion. The effect of seasonal rechargemore » is explored by comparing several seasonal weighting functions to derive the historical recharge concentration. We identify best fit mean ages for each TTD by minimizing the error-weighted, multi-tracer χ2 residual for each seasonal weighting function. We use this methodology to test the ability of each TTD and seasonal input function to fit the observed tracer concentrations, and the effect of choosing different TTD and seasonal recharge functions on the mean age estimation. We find that the estimated mean transit time is a function of both the assumed TTD and seasonal weighting function. Best fits as measured by the χ2 value were achieved for the dispersion model using the seasonal input function developed here for two of the three modeled sites, while at the third site, equally good fits were achieved with the exponential model and the dispersion model and our seasonal input function. The average mean transit time for all TTDs and seasonal input functions converged to similar values at each location. The sensitivity of the estimated mean transit time to the seasonal weighting function was equal to that of the TTD. These results indicated that understanding seasonality of recharge is at least as important as the uncertainty in the flow path distribution in fracture networks and that

  9. Sex and age distribution in transport-related injuries in Tehran.

    PubMed

    Roudsari, Bahman Sayyar; Sharzei, Kaveh; Zargar, Moosa

    2004-05-01

    Intercountry or regional differences in patterns of injury by the road user type have significant implication for prevention policies. In order to have an estimate from the existing conditions of transport-related injuries (TRIs) and especially to evaluate sex and age distribution of traffic accident victims, we analyzed information of 8426 hospitalized trauma patients during 13 months of data gathering process. Forty-five percent of the injuries were related to car accidents and men/women ratio in these patients was 4.2/1. The highest men/women ratio was (16/1) for motorcyclists, while the lowest ratio (1/1), was for rear seat car passengers. Mean (+/-S.D.) age of the patients was 31 (+/-18), and men were nearly 2 years younger than women (33 versus 31). Sixty-seven percent of the females' and 44% of the males' injuries were related to pedestrian crashes. Motorcycle-related injuries in men and car passenger related injuries in women were the second most common type of crash (42 and 22%, respectively). The use of protective devices in our population was worrisome. In only 6% of the male motorcyclists helmet use was reported, and 3% of the male car occupants had used seatbelts at the time of the accident. The condition in the female population was much worse and no use of the protective devices was reported in this group of the patients. Crude mortality rate in men was nearly two times that of women (6.2% versus 3.8%). After adjustment for age, injury severity score (ISS) and category of the road users, men and women had similar mortality rate.

  10. Age- and sex-dependent distribution of persistent organochlorine pollutants in urban foxes.

    PubMed

    Dip, Ramiro; Hegglin, Daniel; Deplazes, Peter; Dafflon, Oscar; Koch, Herbert; Naegeli, Hanspeter

    2003-10-01

    The colonization of urban and suburban habitats by red foxes (Vulpes vulpes) provides a novel sentinel species to monitor the spread of anthropogenic pollutants in densely populated human settlements. Here, red foxes were collected in the municipal territory of Zürich, Switzerland, and their perirenal adipose tissue was examined for persistent organochlorine residues. This pilot study revealed an unexpected pattern of contamination by polychlorinated biphenyls (PCBs), with significantly higher levels of the predominant congeners PCB-138, PCB-153, and PCB-180 in juvenile foxes relative to adult animals. Further data analysis demonstrated that the observed difference was attributable to an age-dependent reduction of PCB concentrations in females, whereas male foxes retained approximately the same PCB burden throughout their life span. A similar sex-related bias between population members has been observed, primarily in marine mammals. Interestingly, the reduction of organochlorine contents with progressive age is reminiscent of human studies, where an extensive maternal transfer of xenobiotics to the offspring has been shown to result in increased exposure levels of infants relative to adults. To our knowledge, this is the first example of an urban wildlife species that faithfully reflects the dynamic distribution of toxic contaminants in the corresponding human population. Suburban and urban foxes occupy habitats in close proximity to humans, depend on anthropogenic food supplies, are relatively long-lived and readily available for sampling, can be easily aged and sexed, have a limited home range, and, therefore, meet several important requirements to serve as a surrogate species for the assessment of toxic health hazards.

  11. College and University Age Distribution of Students New York State, Fall 1987.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Information Center on Education.

    Data summaries on college and university age distribution of New York State students in the fall of 1987 are presented. Information was obtained from the 1987-88 HEDS/IPEDS survey from NYSED-2.6, "Enrollment by Level, Age, Cohort, and Sex, Fall 1987." The 12 tables are as follows (all for institutions of higher education by institutional…

  12. Using groundwater age distributions to estimate the effective parameters of Fickian and non-Fickian models of solute transport

    PubMed Central

    Engdahl, Nicholas B.; Ginn, Timothy R.; Fogg, Graham E.

    2015-01-01

    Groundwater age distributions are used to estimate the parameters of Fickian, and non-Fickian, effective models of solute transport. Based on the similarities between the transport and age equations, we develop a deconvolution based approach that describes transport between two monitoring wells. We show that the proposed method gives exact estimates of the travel time distribution between two wells when the domain is stationary and that the method still provides useful information on transport when the domain is non-stationary. The method is demonstrated using idealized uniform and layered 2-D aquifers. Homogeneous transport is determined exactly and non-Fickian transport in a layered aquifer was also approximated very well, even though this example problem is shown to be scale-dependent. This work introduces a method that addresses a significant limitation of tracer tests and non-Fickian transport modeling which is the difficulty in determining the effective parameters of the transport model. PMID:25821342

  13. Creating Composite Age Groups to Smooth Percentile Rank Distributions of Small Samples

    ERIC Educational Resources Information Center

    Lopez, Francesca; Olson, Amy; Bansal, Naveen

    2011-01-01

    Individually administered tests are often normed on small samples, a process that may result in irregularities within and across various age or grade distributions. Test users often smooth distributions guided by Thurstone assumptions (normality and linearity) to result in norms that adhere to assumptions made about how the data should look. Test…

  14. Past and present seafloor age distributions and the temporal evolution of plate tectonic heat transport

    NASA Astrophysics Data System (ADS)

    Becker, Thorsten W.; Conrad, Clinton P.; Buffett, Bruce; Müller, R. Dietmar

    2009-02-01

    Variations in Earth's rates of seafloor generation and recycling have far-reaching consequences for sea level, ocean chemistry, and climate. However, there is little agreement on the correct parameterization for the time-dependent evolution of plate motions. A strong constraint is given by seafloor age distributions, which are affected by variations in average spreading rate, ridge length, and the age distribution of seafloor being removed by subduction. Using a simplified evolution model, we explore which physical parameterizations of these quantities are compatible with broad trends in the area per seafloor age statistics for the present-day and back to 140 Ma from paleo-age reconstructions. We show that a probability of subduction based on plate buoyancy (slab-pull, or "sqrt(age)") and a time-varying spreading rate fits the observed age distributions as well as, or better than, a subduction probability consistent with an unvarying "triangular" age distribution and age-independent destruction of ocean floor. Instead, we interpret the present near-triangular distribution of ages as a snapshot of a transient state of the evolving oceanic plate system. Current seafloor ages still contain hints of a ˜ 60 Myr periodicity in seafloor production, and using paleoages, we find that a ˜ 250 Myr period variation is consistent with geologically-based reconstructions of production rate variations. These long-period variations also imply a decrease of oceanic heat flow by ˜ - 0.25%/Ma during the last 140 Ma, caused by a 25-50% decrease in the rate of seafloor production. Our study offers an improved understanding of the non-uniformitarian evolution of plate tectonics and the interplay between continental cycles and the self-organization of the oceanic plates.

  15. [Maternal mortality in Spain, 1980-1992. Relationship with birth distributions according to the mother's age].

    PubMed

    Valero Juan, L F; Sáenz González, M C

    1997-11-01

    The maternal mortality evolution in Spain during the 1980-1992 period is reported. The influence of birth distribution according to maternal age is analyzed. The information was gathered from vital statistics published by Instituto Nacional de Estadística. The mortality rates have stabilized since 1985 (4.8 per 10(5) for 1992) associated with the increase in the proportion of births in women aged > or = 30 years (40.6% for 1992). Birth distributions according to maternal age account for 13.1% of the deaths observed. The predictions point to an increase in maternal mortality for the year 2000.

  16. Sensitivity to thermal extremes in Australian Drosophila implies similar impacts of climate change on the distribution of widespread and tropical species.

    PubMed

    Overgaard, Johannes; Kearney, Michael R; Hoffmann, Ary A

    2014-06-01

    Climatic factors influence the distribution of ectotherms, raising the possibility that distributions of many species will shift rapidly under climate change and/or that species will become locally extinct. Recent studies have compared performance curves of species from different climate zones and suggested that tropical species may be more susceptible to climate change than those from temperate environments. However, in other comparisons involving responses to thermal extremes it has been suggested that mid-latitude populations are more susceptible. Using a group of 10 closely related Drosophila species with known tropical or widespread distribution, we undertake a detailed investigation of their growth performance curves and their tolerance to thermal extremes. Thermal sensitivity of life history traits (fecundity, developmental success, and developmental time) and adult heat resistance were similar in tropical and widespread species groups, while widespread species had higher adult cold tolerance under all acclimation regimes. Laboratory measurements of either population growth capacity or acute tolerance to heat and cold extremes were compared to daily air temperature under current (2002-2007) and future (2100) conditions to investigate if these traits could explain current distributions and, therefore, also forecast future effects of climate change. Life history traits examining the thermal sensitivity of population growth proved to be a poor predictor of current species distributions. In contrast, we validate that adult tolerance to thermal extremes provides a good correlate of current distributions. Thus, in their current distribution range, most of the examined species experience heat exposure close to, but rarely above, the functional heat resistance limit. Similarly, adult functional cold resistance proved a good predictor of species distribution in cooler climates. When using the species' functional tolerance limits under a global warming scenario, we

  17. Distribution of Groundwater Ages at Public-Supply Wells: Comparison of Results from Lumped Parameter and Numerical Inverse Models with Multiple Environmental Tracers

    NASA Astrophysics Data System (ADS)

    Eberts, S.; Bohlke, J. K.

    2009-12-01

    Estimates of groundwater age distributions at public-supply wells can provide insight into the vulnerability of these wells to contamination. Such estimates can be used to explore past and future water-quality trends and contaminant peak concentrations when combined with information on contaminant input at the water table. Information on groundwater age distributions, however, is not routinely applied to water quality issues at public-supply wells. This may be due, in part, to the difficulty in obtaining such estimates from poorly characterized aquifers with limited environmental tracer data. To this end, we compared distributions of groundwater ages in discharge from public-supply wells estimated from age tracer data (SF6, CFCs, 3H, 3He) using two different inverse modeling approaches: relatively simple lumped parameter models and more complex distributed-parameter numerical flow models with particle tracking. These comparisons were made in four contrasting hydrogeologic settings across the United States: unconsolidated alluvial fan sediments, layered confined unconsolidated sediments, unconsolidated valley-fill sediments, and carbonate rocks. In all instances, multiple age tracer measurements for the public-supply well of interest were available. We compared the following quantities, which were derived from simulated breakthrough curves that were generated using the various estimated age distributions for the selected wells and assuming the same hypothetical contaminant input: time lag to peak concentration, dilution at peak concentration, and contaminant arrival and flush times. Apparent tracer-based ages and mean and median simulated ages also were compared. For each setting, both types of models yielded similar age distributions and concentration trends, when based on similar conceptual models of local hydrogeology and calibrated to the same tracer measurements. Results indicate carefully chosen and calibrated simple lumped parameter age distribution models

  18. Decay of passive scalars under the action of single scale smooth velocity fields in bounded two-dimensional domains: from non-self-similar probability distribution functions to self-similar eigenmodes.

    PubMed

    Sukhatme, Jai; Pierrehumbert, Raymond T

    2002-11-01

    We examine the decay of passive scalars with small, but nonzero, diffusivity in bounded two-dimensional (2D) domains. The velocity fields responsible for advection are smooth (i.e., they have bounded gradients) and of a single large scale. Moreover, the scale of the velocity field is taken to be similar to the size of the entire domain. The importance of the initial scale of variation of the scalar field with respect to that of the velocity field is strongly emphasized. If these scales are comparable and the velocity field is time periodic, we see the formation of a periodic scalar eigenmode. The eigenmode is numerically realized by means of a deterministic 2D map on a lattice. Analytical justification for the eigenmode is available from theorems in the dynamo literature. Weakening the notion of an eigenmode to mean statistical stationarity, we provide numerical evidence that the eigenmode solution also holds for aperiodic flows (represented by random maps). Turning to the evolution of an initially small scale scalar field, we demonstrate the transition from an evolving (i.e., non-self-similar) probability distribution function (pdf) to a stationary (self-similar) pdf as the scale of variation of the scalar field progresses from being small to being comparable to that of the velocity field (and of the domain). Furthermore, the non-self-similar regime itself consists of two stages. Both stages are examined and the coupling between diffusion and the distribution of the finite time Lyapunov exponents is shown to be responsible for the pdf evolution.

  19. Uranium distribution and 'excessive' U-He ages in iron meteoritic troilite

    NASA Technical Reports Server (NTRS)

    Fisher, D. E.

    1985-01-01

    Fission tracking techniques were used to measure the uranium distribution in meteoritic troilite and graphite. The obtained fission tracking data showed a heterogeneous distribution of tracks with a significant portion of track density present in the form of uranium clusters at least 10 microns in size. The matrix containing the clusters was also heterogeneous in composition with U concentrations of about 0.2-4.7 ppb. U/He ages could not be estimated on the basis of the heterogeneous U distributions, so previously reported estimates of U/He ages in the presolar range are probably invalid.

  20. A theory of the cancer age-specific incidence data based on extreme value distributions

    NASA Astrophysics Data System (ADS)

    Soto-Ortiz, Luis; Brody, James P.

    2012-03-01

    The incidence of cancers varies with age, if normalized this is called the age-specific incidence. A mathematical model that describes this variation should provide a better understanding of how cancers develop. We suggest that the age-specific incidence should follow an extreme value distribution, based on three widely accepted assumptions: (1) a tumor develops from a single cell, (2) many potential tumor progenitor cells exist in a tissue, and (3) cancer is diagnosed when the first of these many potential tumor cells develops into a tumor. We tested this by comparing the predicted distribution to the age-specific incidence data for colon and prostate carcinomas collected by the Surveillance, Epidemiology and End Results network of 17 cancer registries. We found that colon carcinoma age-specific incidence data is consistent with an extreme value distribution, while prostate carcinomas age-specific incidence data generally follows the distribution. This model indicates that both colon and prostate carcinomas only occur in a subset of the population (22% for prostate and 13.5% for colon.) Because of their very general nature, extreme value distributions might be applicable to understanding other chronic human diseases.

  1. Similar patterns of clonally expanded somatic mtDNA mutations in the colon of heterozygous mtDNA mutator mice and ageing humans

    PubMed Central

    Baines, Holly L.; Stewart, James B.; Stamp, Craig; Zupanic, Anze; Kirkwood, Thomas B.L.; Larsson, Nils-Göran; Turnbull, Douglass M.; Greaves, Laura C.

    2014-01-01

    Clonally expanded mitochondrial DNA (mtDNA) mutations resulting in focal respiratory chain deficiency in individual cells are proposed to contribute to the ageing of human tissues that depend on adult stem cells for self-renewal; however, the consequences of these mutations remain unclear. A good animal model is required to investigate this further; but it is unknown whether mechanisms for clonal expansion of mtDNA mutations, and the mutational spectra, are similar between species. Here we show that mice, heterozygous for a mutation disrupting the proof-reading activity of mtDNA polymerase (PolgA+/mut) resulting in an increased mtDNA mutation rate, accumulate clonally expanded mtDNA point mutations in their colonic crypts with age. This results in focal respiratory chain deficiency, and by 81 weeks of age these animals exhibit a similar level and pattern of respiratory chain deficiency to 70-year-old human subjects. Furthermore, like in humans, the mtDNA mutation spectrum appears random and there is an absence of selective constraints. Computer simulations show that a random genetic drift model of mtDNA clonal expansion can accurately model the data from the colonic crypts of wild-type, PolgA+/mut animals, and humans, providing evidence for a similar mechanism for clonal expansion of mtDNA point mutations between these mice and humans. PMID:24915468

  2. Mortality Associated with Severe Sepsis Among Age-Similar Women with and without Pregnancy-Associated Hospitalization in Texas: A Population-Based Study

    PubMed Central

    Oud, Lavi

    2016-01-01

    Background The reported mortality among women with pregnancy-associated severe sepsis (PASS) has been considerably lower than among severely septic patients in the general population, with the difference being attributed to the younger age and lack of chronic illness among the women with PASS. However, no comparative studies were reported to date between patients with PASS and age-similar women with severe sepsis not associated with pregnancy (NPSS). Material/Methods We used the Texas Inpatient Public Use Data File to compare the crude and adjusted hospital mortality between women with severe sepsis, aged 20–34 years, with and without pregnancy-associated hospitalizations during 2001–2010, following exclusion of those with reported chronic comorbidities, as well as alcohol and drug abuse. Results Crude hospital mortality among PASS vs. NPSS hospitalizations was lower for the whole cohort (6.7% vs. 14.1% [p<0.0001]) and those with ≥3 organ failures (17.6% vs. 33.2% [p=0.0100]). Adjusted PASS mortality (odds ratio [95% CI]) was 0.57 (0.38–0.86) [p=0.0070]. Conclusions Hospital mortality was unexpectedly markedly and consistently lower among women with severe sepsis associated with pregnancy, as compared with contemporaneous, age-similar women with severe sepsis not associated with pregnancy, without reported chronic comorbidities. Further studies are warranted to examine the sources of the observed differences and to corroborate our findings. PMID:27286326

  3. Reinstatement of individual past events revealed by the similarity of distributed activation patterns during encoding and retrieval.

    PubMed

    Wing, Erik A; Ritchey, Maureen; Cabeza, Roberto

    2015-04-01

    Neurobiological memory models assume memory traces are stored in neocortex, with pointers in the hippocampus, and are then reactivated during retrieval, yielding the experience of remembering. Whereas most prior neuroimaging studies on reactivation have focused on the reactivation of sets or categories of items, the current study sought to identify cortical patterns pertaining to memory for individual scenes. During encoding, participants viewed pictures of scenes paired with matching labels (e.g., "barn," "tunnel"), and, during retrieval, they recalled the scenes in response to the labels and rated the quality of their visual memories. Using representational similarity analyses, we interrogated the similarity between activation patterns during encoding and retrieval both at the item level (individual scenes) and the set level (all scenes). The study yielded four main findings. First, in occipitotemporal cortex, memory success increased with encoding-retrieval similarity (ERS) at the item level but not at the set level, indicating the reactivation of individual scenes. Second, in ventrolateral pFC, memory increased with ERS for both item and set levels, indicating the recapitulation of memory processes that benefit encoding and retrieval of all scenes. Third, in retrosplenial/posterior cingulate cortex, ERS was sensitive to individual scene information irrespective of memory success, suggesting automatic activation of scene contexts. Finally, consistent with neurobiological models, hippocampal activity during encoding predicted the subsequent reactivation of individual items. These findings show the promise of studying memory with greater specificity by isolating individual mnemonic representations and determining their relationship to factors like the detail with which past events are remembered.

  4. Determination of the age distribution of sea ice from Lagrangian observations of ice motion

    SciTech Connect

    Kwok, R.; Cunningham, G.F.; Rothrock, D.A.; Stern, H.L.

    1995-03-01

    A procedure for monitoring the local age distribution of the Arctic sea ice cover is presented. The age distribution specifies the area covered by ice in different age classes. In the authors` approach, a regular array of grid points is defined initially on the first image of a long time series, and an ice tracker finds the positions of those points in all subsequent images of the series. These Lagrangian points mark the corners of a set of cells that move and deform with the ice cover. The area of each cell changes with each new image or time step. A positive change indicates that ice in a new age class was formed in the cell. A negative change is assumed to have ridged the youngest ice in the cell, reducing its area. The ice in each cell ages as it progresses through the time series. The area of multiyear ice in each cell is computed using an ice classification algorithm. Any area that is not accounted for by the young ice or multiyear ice is assigned to a category of older first-year ice. They thus have a fine age resolution in the young end of the age distribution, and coarse resolution for older ice. The age distribution of the young ice can be converted to a thickness distribution using a simple empirical relation between accumulated freezing-degree days and ice thickness, or using a more complicated thermodynamic model. They describe a general scheme for implementing this procedure for the Arctic Ocean from fall freeze-up until the onset of melt in the spring. The concept is illustrated with a time series of five ERS-1 SAR images spanning a period of 12 days. Such a scheme could be implemented with RADARSAT SAR imagery to provide basin-wide ice age and thickness information.

  5. Seasonal Distribution and Diversity of Ground Arthropods in Microhabitats Following a Shrub Plantation Age Sequence in Desertified Steppe

    PubMed Central

    Liu, Rentao; Zhu, Fan; Song, Naiping; Yang, Xinguo; Chai, Yongqing

    2013-01-01

    In desertified regions, shrub-dominated patches are important microhabitats for ground arthropod assemblages. As shrub age increases, soil, vegetation and microbiological properties can change remarkably and spontaneously across seasons. However, relatively few studies have analyzed how ground arthropods respond to the microhabitats created by shrubs of different plantation ages across seasons. Using 6, 15, 24 and 36 year-old plantations of re-vegetated shrubs (Caragana koushinskii) in the desert steppe of northwestern China as a model system, we sampled ground arthropod communities using a pitfall trapping method in the microhabitats under shrubs and in the open areas between shrubs, during the spring, summer and autumn. The total ground arthropod assemblage was dominated by Carabidae, Melolonthidae, Curculionidae, Tenebrionidae and Formicidae that were affected by plantation age, seasonal changes, or the interaction between these factors, with the later two groups also influenced by microhabitat. Overall, a facilitative effect was observed, with more arthropods and a greater diversity found under shrubs as compared to open areas, but this was markedly affected by seasonal changes. There was a high degree of similarity in arthropod assemblages and diversity between microhabitats in summer and autumn. Shrub plantation age significantly influenced the distribution of the most abundant groups, and also the diversity indices of the ground arthropods. However, there was not an overall positive relationship between shrub age and arthropod abundance, richness or diversity index. The influence of plantation age on arthropod communities was also affected by seasonal changes. From spring through summer to autumn, community indices of ground arthropods tended to decline, and a high degree of similarity in these indices (with fluctuation) was observed among different ages of shrub plantation in autumn. Altogether the recovery of arthropod communities was markedly affected by

  6. Seasonal distribution and diversity of ground arthropods in microhabitats following a shrub plantation age sequence in desertified steppe.

    PubMed

    Liu, Rentao; Zhu, Fan; Song, Naiping; Yang, Xinguo; Chai, Yongqing

    2013-01-01

    In desertified regions, shrub-dominated patches are important microhabitats for ground arthropod assemblages. As shrub age increases, soil, vegetation and microbiological properties can change remarkably and spontaneously across seasons. However, relatively few studies have analyzed how ground arthropods respond to the microhabitats created by shrubs of different plantation ages across seasons. Using 6, 15, 24 and 36 year-old plantations of re-vegetated shrubs (Caragana koushinskii) in the desert steppe of northwestern China as a model system, we sampled ground arthropod communities using a pitfall trapping method in the microhabitats under shrubs and in the open areas between shrubs, during the spring, summer and autumn. The total ground arthropod assemblage was dominated by Carabidae, Melolonthidae, Curculionidae, Tenebrionidae and Formicidae that were affected by plantation age, seasonal changes, or the interaction between these factors, with the later two groups also influenced by microhabitat. Overall, a facilitative effect was observed, with more arthropods and a greater diversity found under shrubs as compared to open areas, but this was markedly affected by seasonal changes. There was a high degree of similarity in arthropod assemblages and diversity between microhabitats in summer and autumn. Shrub plantation age significantly influenced the distribution of the most abundant groups, and also the diversity indices of the ground arthropods. However, there was not an overall positive relationship between shrub age and arthropod abundance, richness or diversity index. The influence of plantation age on arthropod communities was also affected by seasonal changes. From spring through summer to autumn, community indices of ground arthropods tended to decline, and a high degree of similarity in these indices (with fluctuation) was observed among different ages of shrub plantation in autumn. Altogether the recovery of arthropod communities was markedly affected by

  7. The abundance and age distributions of 500 F stars in the solar neighbourhood

    NASA Technical Reports Server (NTRS)

    Clegg, R. E. S.; Bell, R. A.

    1973-01-01

    The uvby catalog of Perry has been used, in conjunction with theoretical uvby colors and stellar evolutionary tracks, to obtain the metal abundance distribution and age distribution of F and G type dwarf stars within 100 pc of the sun. Eighty-three per cent of stars with spectral type F5-G2 have metal content within a factor of 2.5 of the solar abundance, and only 2% have less than one-quarter the solar abundance. The metal abundance distribution, which contains more metal-rich stars than found in previous investigations of F and G dwarfs, has also been compared with the observed metal abundance distribution of G and K giants and the model galaxy calculations of Truran and Cameron (1971). A comparison of the age distribution with evolutionary calculations implies that the rate of star formation in the galaxy may not have decreased by a large factor in the last 10 billion years.

  8. Ages of Globally Distributed Lunar Paleoregoliths and Soils from 3.9 Ga to the Present

    NASA Astrophysics Data System (ADS)

    Fagan, Amy L.; Joy, Katherine H.; Bogard, Donald D.; Kring, David A.

    2014-08-01

    This study determines the ages of 191 discrete lunar regolith samples from the Apollo, Luna, and meteorite collections. Model closure ages (for lithified breccias) and appearance ages (for unconsolidated soils) are calculated using the trapped 40Ar and 36Ar abundances of each sample, determined from published Ar data. Model closure ages of regolith breccias span ~3.9 to 0.01 Ga and appearance ages of soils range from ~3.6 to 0.03 Ga; 169 of these ages are published here for the first time, while 22 are recalculated ages. The regolith breccias with the oldest closure ages originate from the ancient highlands and oldest mare surfaces sampled by the Apollo missions. Soils generally have similar ages to each other, regardless of location and collection depth, with most model ages <2.0 Ga. Together, the soils and regolith breccias represent a record of regolith processes over the past 3.9 Ga. The data illustrate that individual landing sites can provide a diversity of ages, which has implications for planning future missions. Differences in maturity between older and younger regolith samples may reflect a change in collisional regimes over time. We note, too, that the closure ages published here are critical data needed for selecting temporally appropriate regolith samples used to decipher the diversity of impactors hitting the lunar surface over time and how the Sun has changed in time.

  9. Transit times and age distributions for reservoir models represented as nonlinear non-autonomuous systems

    NASA Astrophysics Data System (ADS)

    Müller, Markus; Meztler, Holger; Glatt, Anna; Sierra, Carlos

    2016-04-01

    We present theoretical methods to compute dynamic residence and transit time distributions for non-autonomous systems of pools governed by coupled nonlinear differential equations. Although transit time and age distributions have been used to describe reservoir models for a long time, a closer look to their assumptions reveals two major restrictions of generality in previous studies. First, the systems are assumed to be in equilibrium; and second, the equations under consideration are assumed to be linear. While both these assumptions greatly ease the computation and interpretation of transit time and age distributions they are not applicable to a wide range of problems. Moreover, the transfer of previous results learned from linear systems in steady state to the more complex nonlinear non-autonomous systems that do not even need to have equilibria, can be dangerously misleading. Fortunately the topic of time dependent age and transit time distributions has received some attention recently in hydrology, we aim to compute these distributions for systems of multiple reservoirs. We will discuss how storage selection functions can augment the information represented in an ODE system describing a system of reservoirs. We will present analytical and numerical algorithms and a Monte Carlo simulator to compute solutions for system transit time and age distributions for system-wide storage selection functions including the most simple, but important case of well mixed pools.

  10. Peculiarities of distributions of the cosmic-ray exposure ages of H chondrite falls and finds

    NASA Technical Reports Server (NTRS)

    Alexeev, V. A.

    1993-01-01

    Well known peak in the distribution of the cosmic-ray exposure ages of H chondrites at 6-7 My can be employed as mark in comparison of different populations of H chondrites. It is found the age corresponding to maximum of peak for non-Antarctic falls is higher by (15+/-5) percent of this for non-Antarctic finds. Antarctic H chondrites occupy intermediate position. This effect is probably due to process of weathering.

  11. Spatial distribution of Ar-40/Ar-39 ages in lunar breccia 14301.

    NASA Technical Reports Server (NTRS)

    Megrue, G. H.

    1973-01-01

    The distribution of stable and radioactive argon isotopes in a lunar breccia has been measured in situ by laser probe mass spectrometry. This new technique determines the spatial distribution of Ar-40/Ar-39 ages on less than .1 milligram of material. Calculated Ar-40/Ar-39 ages of clasts within this breccia are 3.7 and 2.9 b.y. Parentless radiogenic Ar-40 exists within the fine-grained matrix and appears to have been trapped simultaneously with solar argon. This 'atmosphere' of ambient gas appears to have been incorporated into the rock by an impact event not more than 3 b.y. ago.

  12. Apparent Transition in the Human Height Distribution Caused by Age-Dependent Variation during Puberty Period

    NASA Astrophysics Data System (ADS)

    Iwata, Takaki; Yamazaki, Yoshihiro; Kuninaka, Hiroto

    2013-08-01

    In this study, we examine the validity of the transition of the human height distribution from the log-normal distribution to the normal distribution during puberty, as suggested in an earlier study [Kuninaka et al.: J. Phys. Soc. Jpn. 78 (2009) 125001]. Our data analysis reveals that, in late puberty, the variation in height decreases as children grow. Thus, the classification of a height dataset by age at this stage leads us to analyze a mixture of distributions with larger means and smaller variations. This mixture distribution has a negative skewness and is consequently closer to the normal distribution than to the log-normal distribution. The opposite case occurs in early puberty and the mixture distribution is positively skewed, which resembles the log-normal distribution rather than the normal distribution. Thus, this scenario mimics the transition during puberty. Additionally, our scenario is realized through a numerical simulation based on a statistical model. The present study does not support the transition suggested by the earlier study.

  13. Influence of anisotropy on velocity and age distribution at Scharffenbergbotnen blue ice area

    NASA Astrophysics Data System (ADS)

    Zwinger, T.; Schäfer, M.; Martín, C.; Moore, J. C.

    2013-06-01

    We use a full-Stokes thermo-mechanically coupled ice-flow model to study the dynamics of the glacier inside Scharffenbergbotnen valley, Dronning Maud Land, Antarctica. The domain encompasses a high accumulation rate region and, downstream a sublimation-dominated bare ice ablation area. The ablation ice area is notable for having old ice at its surface since the vertical velocity is upwards, and horizontal velocities are almost stagnant there. We compare the model simulation with field observations of velocities and the age distribution of the surface ice. A satisfactory match with simulations using an isotropic flow law was not found because of too high horizontal velocities and too slow vertical ones. However, the existence of a pronounced ice fabric may explain the present day surface velocity distribution in the inner Scharffenbergbotnen blue ice area. Near absence of data on the temporal evolution of Scharffenbergbotnen since the Late Glacial Maximum necessitates exploration of the impact of anisotropy using prescribed ice fabrics: isotropic, single maximum, and linear variation with depth, in both two-dimensional and three dimensional flow models. The realistic velocity field simulated with a non-collinear orthotropic flow law, however produced surface ages in significant disagreement with the few reliable age measurements and suggests that the age field is not in a steady state and that the present distribution is a result of a flow reorganization at about 15 000 yr BP. In order to fully understand the surface age distribution a transient simulation starting from the Late Glacial Maximum including the correct initial conditions for geometry, age, fabric and temperature distribution would be needed. It is the first time that the importance of anisotropy has been demonstrated in the ice dynamics of a blue ice area. This is useful to understand ice flow in order to better interpret archives of ancient ice for paleoclimate research.

  14. Influence of anisotropy on velocity and age distribution at Scharffenbergbotnen blue ice area

    NASA Astrophysics Data System (ADS)

    Zwinger, T.; Schäfer, M.; Martín, C.; Moore, J. C.

    2014-04-01

    We use a full-Stokes thermo-mechanically coupled ice-flow model to study the dynamics of the glacier inside Scharffenbergbotnen valley, Dronning Maud Land, Antarctica. The domain encompasses a high accumulation rate region and, downstream, a sublimation-dominated bare ice ablation area. The ablation ice area is notable for having old ice at its surface since the vertical velocity is upwards, and horizontal velocities are almost stagnant there. We compare the model simulation with field observations of velocities and the age distribution of the surface ice. No satisfactory match using an isotropic flow law could be found because of too high vertical velocities and much too high horizontal ones in simulations despite varying enhancement factor, geothermal heat flux and surface temperatures over large ranges. However, the existence of a pronounced ice fabric may explain the observed present-day surface velocity and mass balance distribution in the inner Scharffenbergbotnen blue ice area. Near absence of data on the temporal evolution of Scharffenbergbotnen since the Late Glacial Maximum necessitates exploration of the impact of anisotropy using prescribed ice fabrics: isotropic, single maximum, and linear variation with depth, in both two-dimensional and three-dimensional flow models. The realistic velocity field simulated with a noncollinear orthotropic flow law, however, produced surface ages in significant disagreement with the few reliable age measurements and suggests that the age field is not in a steady state and that the present distribution is a result of a flow reorganization at about 15 000 yr BP. In order to fully understand the surface age distribution, a transient simulation starting from the Late Glacial Maximum including the correct initial conditions for geometry, age, fabric and temperature distribution would be needed. This is the first time that the importance of anisotropy has been demonstrated in the ice dynamics of a blue ice area and

  15. Stability of the age distribution of measles cases over time during outbreaks in Bangladesh, 2004-2006.

    PubMed

    Wiesen, Eric; Wannemuehler, Kathleen; Goodson, James L; Anand, Abhijeet; Mach, Ondrej; Thapa, Arun; O'Connor, Patrick; Linayage, Jayantha; Diorditsa, Serguei; Hasan, A S M Mainul; Uzzaman, Sharif; Jalil Mondal, M D Abdul

    2011-07-01

    Despite recommendations from WHO to conduct measles outbreak response vaccination campaigns based on the age distribution of cases at the beginning of an outbreak, few data exist to specifically examine whether the age distribution of cases remains constant over time in a measles outbreak. This analysis explores this question with use of measles outbreak surveillance data from Bangladesh from the period 2004-2006. Pearson χ(2) tests were conducted of age distributions over 2 periods during 41 large laboratory-confirmed measles outbreaks. Statistically significant changes in age distribution over time were observed in 24% of the outbreaks. No single pattern was detected in the shifts in age distribution; however, an increase in the proportion of cases occurring among infants <9 months of age was evident in 6 outbreaks. These findings suggest a need to consider the possibility of a shift in the age distribution over time when planning an outbreak response vaccination campaign.

  16. Aging Management Guideline for commercial nuclear power plants: Power and distribution transformers

    SciTech Connect

    Toman, G.; Gazdzinski, R.

    1994-05-01

    This Aging Management Guideline (AMG) provides recommended methods for effective detection and mitigation of age-related degradation mechanisms in power and distribution transformers important to license renewal in commercial nuclear power plants. The intent of this AMG to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner which allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  17. The age distribution of self-reported personality disorder traits in a household population.

    PubMed

    Ullrich, Simone; Coid, Jeremy

    2009-04-01

    Stability over time is an essential criterion for the diagnosis of a personality disorder (PD) according to DSM-IV and ICD-10. However, both longitudinal and cross-sectional studies have demonstrated considerable changes of personality disorder traits during life-span, an observation which challenges this assumption. We measured self-reported DSM-IV personality disorder traits in a nationally representative community sample using a cross-sectional design. We investigated the association of dimensional PD scores with age. Our analyses confirmed a decreasing prevalence of personality disorder mean scores across age groups in the population, particularly Cluster B, with an increase in self-reported schizoid and obsessive-compulsive scores. Furthermore, specific interactions of demographic characteristics and age were identified. Analyses of transition points in the distribution of personality disorders across different age groups did not demonstrate increasing stability after age 30 as previously observed for normal personality traits. Significant changes occurred primarily after the third decade.

  18. Grafted Subventricular Zone Neural Stem Cells Display Robust Engraftment and Similar Differentiation Properties and Form New Neurogenic Niches in the Young and Aged Hippocampus

    PubMed Central

    Hattiangady, Bharathi

    2016-01-01

    As clinical application of neural stem cell (NSC) grafting into the brain would also encompass aged people, critical evaluation of engraftment of NSC graft-derived cells in the aged hippocampus has significance. We examined the engraftment and differentiation of alkaline phosphatase-positive NSCs expanded from the postnatal subventricular zone (SVZ), 3 months after grafting into the intact young or aged rat hippocampus. Graft-derived cells engrafted robustly into both young and aged hippocampi. Although most graft-derived cells pervasively migrated into different hippocampal layers, the graft cores endured and contained graft-derived neurons expressing neuron-specific nuclear antigen (NeuN) and γ-amino butyric acid in both groups. A fraction of migrated graft-derived cells in the neurogenic subgranular zone-granule cell layer also expressed NeuN. Neuronal differentiation was, however, occasionally seen amid graft-derived cells that had migrated into non-neurogenic regions, where substantial fractions differentiated into S-100β+ astrocytes, NG2+ oligodendrocyte progenitors, or Olig2+ putative oligodendrocytes. In both age groups, graft cores located in non-neurogenic regions displayed many doublecortin-positive (DCX+) immature neurons at 3 months after grafting. Analyses of cells within graft cores using birth dating and putative NSC markers revealed that DCX+ neurons were newly born neurons derived from engrafted cells and that putative NSCs persisted within the graft cores. Thus, both young and aged hippocampi support robust engraftment and similar differentiation of SVZ-NSC graft-derived cells. Furthermore, some grafted NSCs retain the “stemness” feature and produce new neurons even at 3 months after grafting, implying that grafting of SVZ-NSCs into the young or aged hippocampus leads to establishment of new neurogenic niches in non-neurogenic regions. Significance The results demonstrate that advanced age of the host at the time of grafting has no major

  19. Past and present seafloor age distributions and the temporal evolution of plate tectonic heat transport

    NASA Astrophysics Data System (ADS)

    Becker, T. W.; Conrad, C. P.; Buffett, B.; Muller, D.; Loyd, S.; Lithgow-Bertelloni, C.; Corsetti, F.

    2008-12-01

    Variations in the rates of seafloor generation and recycling have potentially far-reaching consequences for sea level, ocean chemistry and climate. A parameterized framework to describe such variations could guide the study of non-uniformitarian plate tectonic activity, but there is little agreement on the appropriate mechanical description of the surface boundary layer. A strong constraint on the statistics of oceanic convection systems comes from the preserved seafloor age distribution, and additional inferences are possible when paleo-seafloor is modeled based on plate motion reconstructions. Based on previously reconstructed seafloor ages, we recently inferred that oceanic heat flow was larger by ~15% at 60~Ma than today. This signal is mainly caused by the smaller plates that existed previously in the Pacific basin with relatively larger ridge-proximal area of young seafloor. The associated decrease in heat flow is larger than any plausible decrease due to cooling, and therefore hint at cyclic behavior in plate tectonics. We also consider area-per-age statistics for the present-day and back to 140~Ma from new paleo-age reconstructions. Using a simplified seafloor age evolution model we explore which physical parameterizations for the average behavior of the oceanic lithosphere are compatible with broad trends in the data. In particular, we show that a subduction probability based on lithospheric buoyancy ("sqrt(age)") leads to results that are comparable to, or better than, that of the probability distribution that is required to obtain the "triangular" age distribution with age-independent destruction of ocean floor. The current, near triangular distribution of ages and the relative lull in heat flow are likely only snapshots of a transient state during the Wilson cycle. Current seafloor ages still contain hints of a ≤sssim 60~Myr period, cyclic variation of seafloor production, and using paleo-ages for 140~Ma, we find a ~ 400~Myr best-fitting variation

  20. Age Dating Fluvial Sediment Storage Reservoirs to Construct Sediment Waiting Time Distributions

    NASA Astrophysics Data System (ADS)

    Skalak, K.; Pizzuto, J. E.; Benthem, A.; Karwan, D. L.; Mahan, S.

    2015-12-01

    Suspended sediment transport is an important geomorphic process that can often control the transport of nutrients and contaminants. The time a particle spends in storage remains a critical knowledge gap in understanding particle trajectories through landscapes. We dated floodplain deposits in South River, VA, using fallout radionuclides (Pb-210, Cs-137), optically stimulated luminescence (OSL), and radiocarbon dating to determine sediment ages and construct sediment waiting time distributions. We have a total of 14 age dates in two eroding banks. We combine these age dates with a well-constrained history of mercury concentrations on suspended sediment in the river from an industrial release. Ages from fallout radionuclides document sedimentation from the early 1900s to the present, and agree with the history of mercury contamination. OSL dates span approximately 200 to 17,000 years old. We performed a standard Weibull analysis of nonexceedance to construct a waiting time distribution of floodplain sediment for the South River. The mean waiting time for floodplain sediment is 2930 years, while the median is approximately 710 years. When the floodplain waiting time distribution is combined with the waiting time distribution for in-channel sediment storage (available from previous studies), the mean waiting time shifts to approximately 680 years, suggesting that quantifying sediment waiting times for both channel and floodplain storage is critical in advancing knowledge of particle trajectories through watersheds.

  1. Cobalt Distribution and Speciation: Effect of Aging, Intermittent Submergence, In situ Rice Roots

    EPA Science Inventory

    The speciation and distribution of cobalt (Co) in soils is poorly understood. This study was conducted using X-ray absorption spectroscopy (XAS) techniques to examine the influence of soluble Co(II) aging, submergence-dried cycling, and the presence of in vivo rice roots on the...

  2. Aging and Faculty Distribution of Their Work Effort. ASHE 1986 Annual Meeting Paper.

    ERIC Educational Resources Information Center

    Lawrence, Janet H.; Blackburn, Robert T.

    The relative impact of the aging process, pervasive changes in higher education, and career socialization experiences on college faculty members' distributions of work effort was studied. Secondary analyses were completed on the following surveys: the Carnegie Commission on Higher Education Survey (1969) and the Survey of the American…

  3. Bayesian evaluation of groundwater age distribution using radioactive tracers and anthropogenic chemicals

    NASA Astrophysics Data System (ADS)

    Massoudieh, Arash; Sharifi, Soroosh; Solomon, D. Kip

    2012-09-01

    The development of a Bayesian modeling approach for estimation of the age distribution of groundwater using radioactive isotopes and anthropogenic chemicals is described. The model considers the uncertainties associated with the measured tracer concentrations as well as the parameters affecting the concentration of tracers in the groundwater, and it provides the posterior probability densities of the parameters defining the groundwater age distribution using a Markov chain Monte Carlo method. The model also incorporates the effect of dissolution of aquifer minerals on diluting the 14C signature and the uncertainties associated with this process on the inferred age distribution parameters. Two demonstration modeling cases have been performed. First, the method was applied to simulated tracer concentrations at a discharge point of a hypothetical 2-D vertical aquifer with two recharge zones, leading to a mixed groundwater age distribution under different presumed uncertainties. When the error variance of the observed tracer concentrations is considered unknown, the method can estimate the parameters of the fitted exponential-lognormal distribution with a relatively narrow credible interval when five hypothetical samples are assumed to be collected at the discharge point. However, when a single sample is assumed, the credible intervals become wider, and credible estimations of the parameters are not obtained. Second, the method was applied to the data collected at La Selva Biological Station in Costa Rica. In this demonstration application, nine different forms of presumed groundwater age distributions have been considered, including four single forms and five mixed forms, assuming the groundwater consists of distinct young and old fractions. For the medium geometrical standard deviationδc,i = 1.41, the model estimates a young groundwater age of between 0 and 350 years, with the largest odds being given to a mean age of approximately 100 years, and a fraction of young

  4. Thermal and tectonic evolution of the central and southern Appalachians: evidence from distribution, age, and origin of granitic rocks

    SciTech Connect

    Sinha, A.K.; Guy, R.; Hund, E.; Tamburro, E.

    1985-01-01

    The distribution and resolution of thermal events and associated igneous activity can discriminate between tectonic processes that form orogenic terrains, i.e., accretion of terranes, overthrusting of terranes versus thrust stacking within terranes. Reinterpretation of regional tectonics (Higgins et al., 1984) coupled with the authors interpretation of the age, origin, and distribution of granitic rocks suggest a very different mechanism for the evolution of the central and southern Appalachian orogenic belt. The Cambro-Ordovician magmatic arc (weakly bimodal) separated from the North American Margin by a Back arc basin, was thrust over the North American plate margin during the middle Ordovician. The Avalon terrane (Little River allochthon of Higgins et al., 1984) arrived during the late Silurian - but unlike earlier models that require subduction zone related with its arrival, the authors postulate strike-slip tectonics. The gabbro-diorite-syenite association in the Charlotte belt (Macon melange of Higgins) is probably related to grabens associated with the strike-slip accretion. Rocks of similar age (Siluro-Devonian) in the present day Blue Ridge and Inner Piedmont blocks are related to decompressional melting after the Ordovician thrusting. The high pressure metamorphism and associated melting show a range in ages indicating variations in uplift rates or thickness of the crust caused by the initial overthrusting, and do not require a discrete subduction or orogenic event. The Permo-Carboniferous igneous activity, and associated uplift and thrusting with a strike-slip component are related to oblique subduction and post-subduction collision processes.

  5. Simulation of Transient Groundwater Age Distribution in Space and Time, Wairarapa Valley, New Zealand

    NASA Astrophysics Data System (ADS)

    Toews, M. W.; Daughney, C.; Morgenstern, U.; Petrus, K.; Evison, R.; Jackson, B. M.; Cornaton, F. J.

    2013-12-01

    The 3000 km2 Wairarapa Valley is an important agricultural region near Wellington, New Zealand. Improved management of land and water within the region requires understanding of the spatial and temporal variations of water age. This study combines the two main methods currently available for determination of water age: numerical groundwater models and hydrological tracers. A transient finite element groundwater flow and mass transport model was calibrated to match time series measurements of groundwater level and tritium concentration. The groundwater flow model incorporates spatio-temporal recharge, variable stream flow and levels, and variable pump rates. The time-marching Laplace transform Galerkin (TMLTG) technique was then used to evaluate the full spectrum of groundwater age (i.e. age distribution) at each model node and at each time step. To our knowledge this study is the first application of the TMLTG technique to a real-world example, made possible by the rich time-series dataset of tritium measurements that exists for the Wairarapa Valley. Results showed that travel time from the land surface through the aquifer system varies from a few years to several decades and is strongly dependent on location and time. Results also demonstrated important differences between the transient age distributions derived from the TMLTG technique compared to the much simpler steady-state lumped parameter models that are frequently applied to interpret age tracer data. Finally, results had direct application to land and water management, for example for identification of land areas where age distributions vary seasonally, affecting the security of groundwater supplies used for drinking water.

  6. Heart Rate and Blood Pressure Centile Curves and Distributions by Age of Hospitalized Critically Ill Children

    PubMed Central

    Eytan, Danny; Goodwin, Andrew J.; Greer, Robert; Guerguerian, Anne-Marie; Laussen, Peter C.

    2017-01-01

    Heart rate (HR) and blood pressure (BP) form the basis for monitoring the physiological state of patients. Although norms have been published for healthy and hospitalized children, little is known about their distributions in critically ill children. The objective of this study was to report the distributions of these basic physiological variables in hospitalized critically ill children. Continuous data from bedside monitors were collected and stored at 5-s intervals from 3,677 subjects aged 0–18 years admitted over a period of 30 months to the pediatric and cardiac intensive care units at a large quaternary children’s hospital. Approximately 1.13 billion values served to estimate age-specific distributions for these two basic physiological variables: HR and intra-arterial BP. Centile curves were derived from the sample distributions and compared to common reference ranges. Properties such as kurtosis and skewness of these distributions are described. In comparison to previously published reference ranges, we show that children in these settings exhibit markedly higher HRs than their healthy counterparts or children hospitalized on in-patient wards. We also compared commonly used published estimates of hypotension in children (e.g., the PALS guidelines) to the values we derived from critically ill children. This is a first study reporting the distributions of basic physiological variables in children in the pediatric intensive care settings, and the percentiles derived may serve as useful references for bedside clinicians and clinical trials. PMID:28367430

  7. Molecular similarity and property similarity.

    PubMed

    Barbosa, Frédérique; Horvath, Dragos

    2004-01-01

    This paper reviews the main efforts undertaken up to date in order to understand, rationalize and apply the similarity principle (similar compounds=>similar properties) as a computational tool in modern drug discovery. The best suited mathematical expression of this classical working hypothesis of medicinal chemistry needs to be carefully chosen (out of the virtually infinite possible implementations in terms of molecular descriptors and molecular similarity metrics), in order to achieve an optimal validation of the hypothesis that molecules that are neighbors in the Structural Space will also display similar properties. This overview will show why no single "absolute" measure of molecular similarity can be conceived, and why molecular similarity scores should be considered tunable tools that need to be adapted to each problem to solve.

  8. Reconstructing merger timelines using star cluster age distributions: the case of MCG+08-11-002

    NASA Astrophysics Data System (ADS)

    Davies, Rebecca L.; Medling, Anne M.; U, Vivian; Max, Claire E.; Sanders, David; Kewley, Lisa J.

    2016-05-01

    We present near-infrared imaging and integral field spectroscopy of the centre of the dusty luminous infrared galaxy merger MCG+08-11-002, taken using the Near InfraRed Camera 2 (NIRC2) and the OH-Suppressing InfraRed Imaging Spectrograph (OSIRIS) on Keck II. We achieve a spatial resolution of ˜25 pc in the K band, allowing us to resolve 41 star clusters in the NIRC2 images. We calculate the ages of 22/25 star clusters within the OSIRIS field using the equivalent widths of the CO 2.3 μm absorption feature and the Br γ nebular emission line. The star cluster age distribution has a clear peak at ages ≲ 20 Myr, indicative of current starburst activity associated with the final coalescence of the progenitor galaxies. There is a possible second peak at ˜65 Myr which may be a product of the previous close passage of the galaxy nuclei. We fit single and double starburst models to the star cluster age distribution and use Monte Carlo sampling combined with two-sided Kolmogorov-Smirnov tests to calculate the probability that the observed data are drawn from each of the best-fitting distributions. There is a >90 per cent chance that the data are drawn from either a single or double starburst star formation history, but stochastic sampling prevents us from distinguishing between the two scenarios. Our analysis of MCG+08-11-002 indicates that star cluster age distributions provide valuable insights into the timelines of galaxy interactions and may therefore play an important role in the future development of precise merger stage classification systems.

  9. Hatching, dispersal, and bathymetric distribution of age-0 wild lake trout at the Gull Island Shoal complex, Lake Superior

    USGS Publications Warehouse

    Bronte, Charles R.; Selgeby, James H.; Saylor, James H.; Miller, Gerald S.; Foster, Neal R.

    1995-01-01

    We studied age-0 lake trout (Salvelinus namaycush) associated with spawning and nursery areas of the Gull Island Shoal complex in western Lake Superior. Post-emergent age-0 lake trout were captured on rocky spawning substrate with a 3-m beam trawl and at the nursery area with a bottom trawl from June to September 1990 and June to August 1991. Catch data suggested that age-0 lake trout move distances of 7–11 km to the nursery area over a 3-month period. Water currents, measured at Gull Island Shoal, may be a part of the transport mechanism. Examination of daily-growth increments on the sagittae and back-calculation from the date of capture revealed that most fish hatched between 6 June and 19 July in 1990 and between 30 April and 30 May in 1991. The duration of the hatch was 100 days in 1990 and 120 days in 1991, and the estimated incubation period is about 7 months for lake trout eggs at this site. Similar hatch-date distributions of age-0 captured on different sampling dates suggested that natural mortality was low.

  10. X-Ray induced cataract is preceded by LEC loss, and coincident with accumulation of cortical DNA, and ROS; similarities with age-related cataracts

    PubMed Central

    Zitnik, Galynn; Tsai, Ryan; Wolf, Norman

    2010-01-01

    -eyes were examined for ROS damage to DNA with antibodies specific for 8-OH-G lesions. The frequency of 8-OH-G lesions increased dramatically in lenses from old unirradiated mice over 24 months of age, and similarly in X-irradiated lenses by 9–11 months post irradiation. The accumulation of cortical nuclei was not the result of conversion or invasion by myofibroblasts as tested by antibodies to a marker for such cells, alpha smooth muscle actin. Conclusions X-irradiation damage induces a large decrease in surface LECs over a period of 3–11 months post X-irradiation of young mice. These changes are similar in extent to those seen in 24–29 months-old control mouse lenses with age-related cataracts. In 24+ month-old unirradiated mice the secondary lens fibers are not able to degrade nuclei or nuclear DNA efficiently and accumulate large numbers of cortical nuclei and nuclear fragments as well as ROS and 8-OHG lesions. X-irradiated lenses develop the same abnormalities in a more accelerated fashion. The extensive loss of LECS and accumulation of undegraded nuclei, ROS, and ROS damage may play a causal role in cataract generation in both unirradiated old mice and in previously irradiated young adult mice. PMID:20806081

  11. IDH mutant diffuse and anaplastic astrocytomas have similar age at presentation and little difference in survival: a grading problem for WHO.

    PubMed

    Reuss, David E; Mamatjan, Yasin; Schrimpf, Daniel; Capper, David; Hovestadt, Volker; Kratz, Annekathrin; Sahm, Felix; Koelsche, Christian; Korshunov, Andrey; Olar, Adriana; Hartmann, Christian; Reijneveld, Jaap C; Wesseling, Pieter; Unterberg, Andreas; Platten, Michael; Wick, Wolfgang; Herold-Mende, Christel; Aldape, Kenneth; von Deimling, Andreas

    2015-06-01

    The WHO 2007 classification of tumors of the CNS distinguishes between diffuse astrocytoma WHO grade II (A II(WHO2007)) and anaplastic astrocytoma WHO grade III (AA III(WHO2007)). Patients with A II(WHO2007) are significantly younger and survive significantly longer than those with AA III(WHO2007). So far, classification and grading relies on morphological grounds only and does not yet take into account IDH status, a molecular marker of prognostic relevance. We here demonstrate that WHO 2007 grading performs poorly in predicting prognosis when applied to astrocytoma carrying IDH mutations. Three independent series including a total of 1360 adult diffuse astrocytic gliomas with IDH mutation containing 683 A II(IDHmut), 562 AA III(IDHmut) and 115 GBM(IDHmut) have been examined for age distribution and survival. In all three series patients with A II(IDHmut )and AA III(IDHmut) were of identical age at presentation of disease (36-37 years) and the difference in survival between grades was much less (10.9 years for A II(IDHmut), 9.3 years for AA III(IDHmut)) than that reported for A II(WHO2007) versus AA III(WHO2007). Our analyses imply that the differences in age and survival between A II(WHO2007) and AA III(WHO2007) predominantly depend on the fraction of IDH-non-mutant astrocytomas in the cohort. This data poses a substantial challenge for the current practice of astrocytoma grading and risk stratification and is likely to have far-reaching consequences on the management of patients with IDH-mutant astrocytoma.

  12. Professional ballet dancers have a similar prevalence of articular cartilage defects compared to age- and sex-matched non-dancing athletes.

    PubMed

    Mayes, Susan; Ferris, April-Rose; Smith, Peter; Garnham, Andrew; Cook, Jill

    2016-12-01

    Ballet exposes the hip joint to repetitive loading in extreme ranges of movement and may predispose a dancer to pain and osteoarthritis (OA). The aims of this study were to compare the prevalence of cartilage defects in professional ballet dancers and athletes and to determine the relationship of clinical signs and symptoms. Forty-nine male and female, current and retired professional ballet dancers and 49 age- and sex-matched non-dancing athletes completed hip pain questionnaires, including the Copenhagen Hip and Groin Outcome Score (HAGOS), and underwent hip range of movement (ROM) testing and 3-Tesla magnetic resonance imaging to score cartilage defects (no defect, grade 1: focal partial defect and grade 2: diffuse or full thickness defect). Thirty (61 %) dancers and 27 (55 %) athletes had cartilage defects (p = 0.54). The frequency of grade 1 and 2 cartilage defects did not differ between dancers and athletes (p = 0.83). The frequency of cartilage defects was similar in male and female dancers (p = 0.34), and male and female athletes (p = 0.24). Cartilage defects were not related to history of hip pain (p = 0.34), HAGOS pain (p = 0.14), sports/rec (p = 0.15) scores or hip internal rotation ≤20° (p > 0.01). Cartilage defects were related to age in male dancers (p = 0.002). Ballet dancers do not appear to be at a greater risk of cartilage injury compared to non-dancing athletes. Male dancers develop cartilage defects at an earlier age than athletes and female dancers. Cartilage defects were not related to clinical signs and symptoms; thus, prospective studies are required to determine which cartilage defects progress to symptomatic hip OA.

  13. Phylogeographic Analysis Elucidates the Influence of the Ice Ages on the Disjunct Distribution of Relict Dragonflies in Asia

    PubMed Central

    Büsse, Sebastian; von Grumbkow, Philipp; Hummel, Susanne; Shah, Deep Narayan; Tachamo Shah, Ram Devi; Li, Jingke; Zhang, Xueping; Yoshizawa, Kazunori; Wedmann, Sonja; Hörnschemeyer, Thomas

    2012-01-01

    Unusual biogeographic patterns of closely related groups reflect events in the past, and molecular analyses can help to elucidate these events. While ample research on the origin of disjunct distributions of different organism groups in the Western Paleartic has been conducted, such studies are rare for Eastern Palearctic organisms. In this paper we present a phylogeographic analysis of the disjunct distribution pattern of the extant species of the strongly cool-adapted Epiophlebia dragonflies from Asia. We investigated sequences of the usually more conserved 18 S rDNA and 28 S rDNA genes and the more variable sequences of ITS1, ITS2 and CO2 of all three currently recognised Epiophlebia species and of a sample of other odonatan species. In all genes investigated the degrees of similarity between species of Epiophlebia are very high and resemble those otherwise found between different populations of the same species in Odonata. This indicates that substantial gene transfer between these populations occurred in the comparatively recent past. Our analyses imply a wide distribution of the ancestor of extant Epiophlebia in Southeast Asia during the last ice age, when suitable habitats were more common. During the following warming phase, its range contracted, resulting in the current disjunct distribution. Given the strong sensitivity of these species to climatic parameters, the current trend to increasing global temperatures will further reduce acceptable habitats and seriously threaten the existences of these last representatives of an ancient group of Odonata. PMID:22666462

  14. Phylogeographic analysis elucidates the influence of the ice ages on the disjunct distribution of relict dragonflies in Asia.

    PubMed

    Büsse, Sebastian; von Grumbkow, Philipp; Hummel, Susanne; Shah, Deep Narayan; Tachamo Shah, Ram Devi; Li, Jingke; Zhang, Xueping; Yoshizawa, Kazunori; Wedmann, Sonja; Hörnschemeyer, Thomas

    2012-01-01

    Unusual biogeographic patterns of closely related groups reflect events in the past, and molecular analyses can help to elucidate these events. While ample research on the origin of disjunct distributions of different organism groups in the Western Paleartic has been conducted, such studies are rare for Eastern Palearctic organisms. In this paper we present a phylogeographic analysis of the disjunct distribution pattern of the extant species of the strongly cool-adapted Epiophlebia dragonflies from Asia. We investigated sequences of the usually more conserved 18 S rDNA and 28 S rDNA genes and the more variable sequences of ITS1, ITS2 and CO2 of all three currently recognised Epiophlebia species and of a sample of other odonatan species. In all genes investigated the degrees of similarity between species of Epiophlebia are very high and resemble those otherwise found between different populations of the same species in Odonata. This indicates that substantial gene transfer between these populations occurred in the comparatively recent past. Our analyses imply a wide distribution of the ancestor of extant Epiophlebia in Southeast Asia during the last ice age, when suitable habitats were more common. During the following warming phase, its range contracted, resulting in the current disjunct distribution. Given the strong sensitivity of these species to climatic parameters, the current trend to increasing global temperatures will further reduce acceptable habitats and seriously threaten the existences of these last representatives of an ancient group of Odonata.

  15. Behavioral responses to and brain distribution of morphine in mature adult and aged mice

    SciTech Connect

    Burton, C.K.; Ho, I.K.; Hoskins, B.

    1986-03-01

    Mature adult (3-6 mo old) and aged (2 yr old) male ICR mice were injected with 10 to 100 mg/kg morphine, s.c. The ED50 values for running behavior (as measured using Stoelting activity monitors and having each mouse serve as its own control) representing 5 times control activity was approximately 7.5 mg/kg for aged mice and approximately 17.5 mg/kg for the mature adults. The ED50 values for analgesia 1 hr after morphine administration using the tail-flick method (max. response time = 8 sec) were approx. 70 mg/kg for the aged mice and 15 mg/kg for the mature adults. One hour after injecting /sup 3/H-morphine at doses of 30 and 100 mg/kg, 0.13 and 0.14% of the doses appeared in brains of aged and mature adult mice, respectively. Regional distribution of the morphine was the same for both age groups. Expressed as percent of total brain morphine, it was as follows: cortex, 30%; midbrain, 18%; cerebellum, 17%; medulla, 12%; pons, 9%; striatum, 8% and periaqueductal gray, 6%. Expressed as g morphine/g tissue for the 2 doses, the distribution was; periaqueductal gray, 30 and 80; striatum, 9 and 34; medulla, 6 and 20 pons; 5 and 19; cerebellum, 4 and 13; midbrain 2.5 and 8.5 and cortex, 2 and 8. These results suggest that the differences in response to morphine by the two age groups were due to age-related differences in opioid receptor populations and/or affinities.

  16. How old is this bird? The age distribution under some phase sampling schemes.

    PubMed

    Hautphenne, Sophie; Massaro, Melanie; Taylor, Peter

    2017-04-03

    In this paper, we use a finite-state continuous-time Markov chain with one absorbing state to model an individual's lifetime. Under this model, the time of death follows a phase-type distribution, and the transient states of the Markov chain are known as phases. We then attempt to provide an answer to the simple question "What is the conditional age distribution of the individual, given its current phase"? We show that the answer depends on how we interpret the question, and in particular, on the phase observation scheme under consideration. We then apply our results to the computation of the age pyramid for the endangered Chatham Island black robin Petroica traversi during the monitoring period 2007-2014.

  17. Analyzing nutrient distribution in different particle-size municipal aged refuse.

    PubMed

    Li, Guangke; Hou, Fen; Guo, Zhen; Yao, Gaoyi; Sang, Nan

    2011-11-01

    To investigate the feasibility of using aged municipal solid waste as farmland soil, it is essential to study its nutritive compositions for plant growth. Previous studies have demonstrated that the properties of different particle-size aged refuse are very different, therefore, the present study was conducted to evaluate the adequacy of three elements (N, P, K) and the fractionation of inorganic P in the aged refuse with a particle-size distribution of 900 to 300, 300 to 150, 150 to 105, 105 to 90 and 90 to 0 μm. The results indicate that (1) total quantities of N, P, K were much larger than that in the general soil and the quantities of available N, P and K were also adequate; (2) total content of P was sufficient, but the ratio of available-P to total P was not high enough; (3) with the decrease of particle size, the contents of these elements presented different trends. The results implicate that total contents of N, P and K were enough for the aged refuse being exploited as cultivated soil, and different gradation of aged refuse could be added to improve poor soils. It provides scientific evidence for utilizing different particle-size aged refuse comprehensively.

  18. Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in northern Alaska

    USGS Publications Warehouse

    Dusel-Bacon, Cynthia; Brosge, William Peters; Till, Alison B.; Doyle, Elizabeth O.; Mayfield, Charles F.; Reiser, Hillard N.; Miller, Thomas P.

    1989-01-01

    Approximately half of the exposed bedrock in northern Alaska has been regionally metamorphosed. The most widespread metamorphic episode that affected northern Alaska occurred under low-grade, initially high-pressure (blueschist-facies) conditions during Mesozoic time. This episode is thought to have been related to the obduction of one or more oceanic terranes onto the continental margin of North America. Rocks whose metamorphism is considered to have been part of this major episode have an aerial distribution of approximately 10,000 km2 in the southern Brooks Range, 5,000 km2 across much of the Seward Peninsula, and 800 km2 in the Ruby geanticline within the southeastern borderlands of the Yukon-Koyukuk basin. In the southern Brooks Range and on the Seward Peninsula, continental rocks experienced a clockwise pressure-temperature path that evolved during Middle Jurassic to late Early Cretaceous time from the low- to high-temperature subfacies of the blueschist facies and, finally, due to decreasing pressure, evolved to the greenschist facies. Metamorphism in the southern Brooks Range was associated with north-vergent compression along a south-dipping subduction zone that emplaced the oceanic rocks of the Angayucham terrane (represented by klippen of ultramafic rocks and prehnite-pumpellyite-facies metabasite, metatuff, metachert, and metasedimentary rocks) onto the continental margin. The present structural and metamorphic relation between the continental blueschistand greenschist-facies rocks and the structurally overlying lower temperature and pressure oceanic prehnite-pumpellyite-facies rocks to the south indicates that postmetamorphic or late metamorphic down-to-the-south, low-angle extensional faulting has dismembered the upper plate and removed much of the section that originally buried the blueschists. High-pressure metamorphism on the Seward Peninsula probably had a similar origin to that in the southern Brooks Range, but remnants of the overriding plate

  19. Competition and Habitat Quality Influence Age and Sex Distribution in Wintering Rusty Blackbirds

    PubMed Central

    Mettke-Hofmann, Claudia; Hamel, Paul B.; Hofmann, Gerhard; Zenzal Jr., Theodore J.; Pellegrini, Anne; Malpass, Jennifer; Garfinkel, Megan; Schiff, Nathan

    2015-01-01

    Bird habitat quality is often inferred from species abundance measures during the breeding and non-breeding season and used for conservation management decisions. However, during the non-breeding season age and sex classes often occupy different habitats which suggest a need for more habitat-specific data. Rusty Blackbird (Euphagus carolinus) is a forested wetland specialist wintering in bottomland hardwood forests in the south-eastern U. S. and belongs to the most steeply declining songbirds in the U.S. Little information is available to support priority birds such as the Rusty Blackbird wintering in this threatened habitat. We assessed age and sex distribution and body condition of Rusty Blackbirds among the three major habitats used by this species in the Lower Mississippi Alluvial Valley and also measured food availability. Overall, pecan groves had the highest biomass mainly driven by the amount of nuts. Invertebrate biomass was highest in forests but contributed only a small percentage to overall biomass. Age and sex classes were unevenly distributed among habitats with adult males primarily occupying pecan groves containing the highest nut biomass, females being found in forests which had the lowest nut biomass and young males primarily staying in forest fragments along creeks which had intermediate nut biomass. Males were in better body condition than females and were in slightly better condition in pecan groves. The results suggest that adult males occupy the highest quality habitat and may competitively exclude the other age and sex classes. PMID:25946335

  20. Competition and habitat quality influence age and sex distribution in wintering rusty blackbirds.

    PubMed

    Mettke-Hofmann, Claudia; Hamel, Paul B; Hofmann, Gerhard; Zenzal, Theodore J; Pellegrini, Anne; Malpass, Jennifer; Garfinkel, Megan; Schiff, Nathan; Greenberg, Russell

    2015-01-01

    Bird habitat quality is often inferred from species abundance measures during the breeding and non-breeding season and used for conservation management decisions. However, during the non-breeding season age and sex classes often occupy different habitats which suggest a need for more habitat-specific data. Rusty Blackbird (Euphagus carolinus) is a forested wetland specialist wintering in bottomland hardwood forests in the south-eastern U. S. and belongs to the most steeply declining songbirds in the U.S. Little information is available to support priority birds such as the Rusty Blackbird wintering in this threatened habitat. We assessed age and sex distribution and body condition of Rusty Blackbirds among the three major habitats used by this species in the Lower Mississippi Alluvial Valley and also measured food availability. Overall, pecan groves had the highest biomass mainly driven by the amount of nuts. Invertebrate biomass was highest in forests but contributed only a small percentage to overall biomass. Age and sex classes were unevenly distributed among habitats with adult males primarily occupying pecan groves containing the highest nut biomass, females being found in forests which had the lowest nut biomass and young males primarily staying in forest fragments along creeks which had intermediate nut biomass. Males were in better body condition than females and were in slightly better condition in pecan groves. The results suggest that adult males occupy the highest quality habitat and may competitively exclude the other age and sex classes.

  1. Age-related change of technetium-99m-HMDP distribution in the skeleton

    SciTech Connect

    Kigami, Yusuke; Yamamoto, Itsuo; Ohnishi, Hideo

    1996-05-01

    To understand age-related changes of whole-body and regional skeletal metabolism, it is important to investigate the mechanisms of age-related bone loss and to develop suitable treatments for it. Bone biopsies show metabolism of the particular site examined while biochemical markers for bone metabolism reflect total skeletal metabolis. Bone scintigraphy is a convenient and simple way to analyze whole-body and regional skeletal metabolism. We attempted to study and understand age-related changes in bone metabolism by quantifying the bone scan and correlating it with biochemical bone metabolic markers. The whole-body skeletal uptake (WBSU) and whole-body skeletal tracer distribution pattern were studied in men and women by bone scintigraphy using {sup 99m}Tc-hydroxy-methane-diphosphonate (HMDP). Bone scans were performed using a standard protocol and quantified by setting regions of interest (ROIs) on selected regions. WBSU and the skeletal distribution pattern were compared with simultaneously obtained serum biochemical markers. WBSU showed an increase with age in both sexes, but in women, uptake in the head and legs increased more relatively than in the thoracic region, while in men no such tendency was observed. Increase of WBSU and relative increase of uptakes in the head demonstrated a weak correlation with the serum levels of alkaline phosphatase and type 1 collagen metabolites. These results show an age-related increase of skeletal turnover and sex-dependent regional skeletal metabolism. The age-related changes seen in bone scintigrams might be a sign of progressive bone loss, reflecting changes in local bone matabolism. 23 refs., 3 figs., 1 tab.

  2. Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach

    PubMed Central

    Nonaka, Kouichi; Ohata, Ken; Ban, Shinichi; Ichihara, Shin; Takasugi, Rumi; Minato, Yohei; Tashima, Tomoaki; Matsuyama, Yasushi; Takita, Maiko; Matsuhashi, Nobuyuki; Neumann, Helmut

    2015-01-01

    Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared

  3. Similarity of the CDC and WHO weight-for-length growth charts in predicting risk of obesity at age 5 years.

    PubMed

    Rifas-Shiman, Sheryl L; Gillman, Matthew W; Oken, Emily; Kleinman, Ken; Taveras, Elsie M

    2012-06-01

    The World Health Organization (WHO) 2006 weight-for-length (WFL) or BMI growth charts are now recommended as the new standard for children under 24 months. The objective of this study was to examine associations of ever being overweight during 1-24 months, based on the older Centers for Disease Control and Prevention (CDC) and WHO cutpoints, with risk of obesity at age 5 years. From well-child visits to a Massachusetts multi-site group practice during 1980-2008, we studied 15,488 children with length/height and weight measurements at 1, 6, 12, 18, and 24 months, and at 5 years. The main exposures were ever being overweight during 1-24 months using each of three cutpoints: CDC WFL ≥ 95th percentile, WHO WFL or BMI ≥ 97.7th percentile. The main outcome was obesity at 5 years (CDC BMI ≥ 95th percentile). We calculated multivariable odds ratios (ORs), adjusted for age, sex, race/ethnicity, and year. At 5 years, 10.8% of participants were obese. During 1-24 months, 21.3, 18.3, and 20.2% were ever overweight using CDC WFL, WHO WFL, and WHO BMI cutpoints, respectively. ORs (95% confidence interval (CI)) for associations of ever being overweight during 1-24 months with obesity at 5 years were 6.0 (5.4, 6.6), 6.3 (5.7, 7.0), and 6.0 (5.4, 6.7), respectively. Ever being overweight in the first 2 years of life is a strong predictor of obesity at 5 years. CDC WFL, WHO WFL, and WHO BMI cutpoints for overweight in early childhood provided similar estimates of later obesity risk.

  4. Maize Varieties Released in Different Eras Have Similar Root Length Density Distributions in the Soil, Which Are Negatively Correlated with Local Concentrations of Soil Mineral Nitrogen

    PubMed Central

    Ning, Peng; Li, Sa; White, Philip J.; Li, Chunjian

    2015-01-01

    Larger, and deeper, root systems of new maize varieties, compared to older varieties, are thought to have enabled improved acquisition of soil resources and, consequently, greater grain yields. To compare the spatial distributions of the root systems of new and old maize varieties and their relationships with spatial variations in soil concentrations of available nitrogen (N), phosphorus (P) and potassium (K), two years of field experiments were performed using six Chinese maize varieties released in different eras. Vertical distributions of roots, and available N, P and K in the 0–60 cm soil profile were determined in excavated soil monoliths at silking and maturity. The results demonstrated that new maize varieties had larger root dry weight, higher grain yield and greater nutrient accumulation than older varieties. All varieties had similar total root length and vertical root distribution at silking, but newer varieties maintained greater total root length and had more roots in the 30–60 cm soil layers at maturity. The spatial variation of soil mineral N (Nmin) in each soil horizon was larger than that of Olsen-P and ammonium-acetate-extractable K, and was inversely correlated with root length density (RLD), especially in the 0–20 cm soil layer. It was concluded that greater acquisition of mineral nutrients and higher yields of newer varieties were associated with greater total root length at maturity. The negative relationship between RLD and soil Nmin at harvest for all varieties suggests the importance of the spatial distribution of the root system for N uptake by maize. PMID:25799291

  5. A decade plus of snow distribution observations in a mountain catchment: assessing variability, self-similarity, and the representativeness of an index site

    NASA Astrophysics Data System (ADS)

    Winstral, A. H.; Marks, D. G.

    2012-12-01

    This study presents an analysis of eleven years of manually sampled snow depth and SWE data at the drift-dominated Reynolds Mountain East catchment (0.36 km^2) in southwestern Idaho, U.S.A. The dataset includes eleven mid-winter surveys and ten surveys that targeted peak accumulation in the early spring. Depths were sampled on the same 30-meter grid covering the entire catchment in each survey. Densities were sampled at a coarser resolution using a depth-stratified random sampling scheme. In 19 of the 21 surveys, snow density increased with increasing depth until an upper limit was attained in the drifts. The coefficient of variation (CV) for mid-winter snow depths varied from 0.46 to 0.75 and was significantly related to seasonal wind speeds (p = 0.02). Energy inputs, correlated inversely to accumulation rates in this catchment, caused variability to increase as melt increased through the season. The CV for all three surveys that took place after peak accumulation exceeded 1.0. Inter-seasonal distributions were strongly correlated - correlation coefficients ranged from 0.70 to 0.97 with a mean of 0.84. An index site with similar site characteristics to NRCS Snotel sites gave reasonable approximations of average catchment SWE in drier years, however as snowfall increased this site increasingly over-estimated basin-wide SWE. Though others have found snow distributions to be reasonably approximated by two-parameter lognormal distributions, Kolmogorov-Smirnov goodness of fit tests rejected this hypothesis (p < 0.01) in 20 of the 21 observed distributions.

  6. DISTRIBUTION OF CARIOUS AND NON-CARIOUS CERVICAL LESIONS AND GINGIVAL RECESSION AT AGE RELATED ASPECTS.

    PubMed

    Mamaladze, M; Khutsishvili, L; Zarkua, E

    2016-07-01

    The current study aims at differentiating carious and/or non-carious diseases developed in Class 5 region and detecting the distribution rate at the age aspects. The study was conducted at the Dental Clinicand Educational-Research Center "Unident" LTD and Dental Clinic "Dens". 256 patients were involved in the study. All patients underwent a routine dental examination, while rentgenovisiography and CT were performed in case of need. For gathering the detailed medical history and integrated study of Class 5 defects, a special questionnaire/survey, providing detailed information on each patient, was developed. The conducted study revealed the following: The patients were divided into 3 age groups: 16-30 of ages (77 patients, I study group), 30-50 of ages (97 patients, II study group) and 50-70 of ages (82, III study group), respectively. In total 5802 teeth were examined. The subject of our interest was identification of intact and damaged teeth (affected with caries and non-carious diseases) in the above-mentioned contingent. It was found that carious disease of cervical zone of tooth (Class 5) most often was revealed in 30-50 age group (202 cases), which is 1.8-fold higher than the same index in the I study group (144) and 1.4-fold higher in the III study group (183), respectively; The highest rate of non-carious lesions (erosion, abrasion, abfraction) of dental neck was recorded in examined 50-70 age group (294 cases), which was 4.6 -fold higher than in the I study group (64) and 2.1 -fold higher in II study group (140), respectively; The lowest incidence of gingival recession was in the I study group (65 cases), which is 6.3 -fold lower than in the II study group (412) and 7.5-fold lower than - the III group (493).

  7. Comparison of particle-tracking and lumped-parameter models for determining groundwater age distributions and nitrate in water-supply wells, Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Jurgens, B. C.; Bohlke, J. K.; Kauffman, L. J.; Belitz, K.

    2013-12-01

    Age distributions for 30 production wells (mostly public-supply) were determined using two methods: 1) calibration of age tracer data with lumped parameter models (LPMs) and 2) by advective particle tracking (PT) simulations using MODPATH and a regional steady-state groundwater flow model. The LPMs were calibrated with measurements of 3H, 3He(trit), and 14C by minimizing the Chi-square test statistic using a non-linear solver. A partial exponential model (PEM) was the primary LPM used in this study and a combination of two PEMs were used in cases where binary age mixtures were identified. The PEM is a reformulated version of the exponential model that is parameterized to simulate the age distribution in a well that is screened over any finite interval within the aquifer. The regional numerical model was calibrated to water-levels and gradients, and simulated PT age tracer concentrations were calibrated to the MODPATH porosity value. Age distributions were then used to predict nitrate concentrations in wells using agricultural application rates of nitrate in the central eastside of the San Joaquin Valley, California. Both methods showed that wells in the study area captured groundwater with a broad range of ages, spanning decades to millennia. Age distributions from the LPMs predicted age tracer and nitrate concentrations more accurately than the regional PT simulation; whereas PT simulations incorporating more detailed information about water-levels and hydraulic gradients near wells also provided good fits. 14C concentrations were not simulated well by the regional steady-state model, especially for wells with a significant fraction of old groundwater, because the model simulates the current, perturbed system and does not simulate recharge rates and velocities of the predevelopment system. Results from the LPMs yielded an average recharge rate of 0.55 m/yr, which was similar to the average recharge rate of 0.54 m/yr determined from a water budget analysis for the

  8. Differential Protein Distribution between the Nucleus and Mitochondria: Implications in Aging

    PubMed Central

    Lionaki, Eirini; Gkikas, Ilias; Tavernarakis, Nektarios

    2016-01-01

    The coordination of nuclear and mitochondrial genomes plays a pivotal role in maintenance of mitochondrial biogenesis and functionality during stress and aging. Environmental and cellular inputs signal to nucleus and/or mitochondria to trigger interorganellar compensatory responses. Loss of this tightly orchestrated coordination results in loss of cellular homeostasis and underlies various pathologies and age-related diseases. Several signaling cascades that govern interorganellar communication have been revealed up to now, and have been classified as part of the anterograde (nucleus to mitochondria) or retrograde (mitochondrial to nucleus) response. Many of these molecular pathways rely on the dual distribution of nuclear or mitochondrial components under basal or stress conditions. These dually localized components usually engage in specific tasks in their primary organelle of function, whilst upon cellular stimuli, they appear in the other organelle where they engage in the same or a different task, triggering a compensatory stress response. In this review, we focus on protein factors distributed between the nucleus and mitochondria and activated to exert their functions upon basal or stress conditions. We further discuss implications of bi-organellar targeting in the context of aging. PMID:27695477

  9. Do predators influence the distribution of age-0 kokanee in a Colorado Reservoir?

    USGS Publications Warehouse

    Hardiman, J.M.; Johnson, B.M.; Martinez, P.J.

    2004-01-01

    Seasonal changes in reservoir conditions such as productivity, light, and temperature create spatiotemporal variation in habitat that may segregate or aggregate predators and prey, producing implications for the distribution, growth, and survival of fishes. We used hydroacoustics to document the diel vertical distribution of age-0 kokanee Oncorhynchus nerka relative to environmental gradients at Blue Mesa Reservoir, Colorado, during May-August of 2002. Temperature, light, and zooplankton density profiles were examined relative to foraging conditions for kokanee and their primary predator, lake trout Salvelinus namaycush. Age-0 kokanee displayed large diel vertical migrations in May despite the lack of an energetic advantage before reservoir stratification. Age-0 kokanee minimized near-surface foraging at this time, perhaps to avoid predation by visual predators, such as lake trout, in the well-lit surface waters. Strong reservoir stratification in midsummer appeared to provide a thermal refuge from lake trout that the kokanee exploited. By August vertical migrations were shallow and most kokanee remained in the epilimnion throughout the day. Although the energetic implications of the late-summer strategy are unclear, it appears that kokanee were responding to changes in their predator environment. A robust model for kokanee diel vertical migration across a range of systems should include a predator avoidance component.

  10. Asteroid age distributions determined by space weathering and collisional evolution models

    NASA Astrophysics Data System (ADS)

    Willman, Mark; Jedicke, Robert

    2011-01-01

    We provide evidence of consistency between the dynamical evolution of main belt asteroids and their color evolution due to space weathering. The dynamical age of an asteroid's surface (Bottke, W.F., Durda, D.D., Nesvorný, D., Jedicke, R., Morbidelli, A., Vokrouhlický, D., Levison, H. [2005]. Icarus 175 (1), 111-140; Nesvorný, D., Jedicke, R., Whiteley, R.J., Ivezić, Ž. [2005]. Icarus 173, 132-152) is the time since its last catastrophic disruption event which is a function of the object's diameter. The age of an S-complex asteroid's surface may also be determined from its color using a space weathering model (e.g. Willman, M., Jedicke, R., Moskovitz, N., Nesvorný, D., Vokrouhlický, D., Mothé-Diniz, T. [2010]. Icarus 208, 758-772; Jedicke, R., Nesvorný, D., Whiteley, R.J., Ivezić, Ž., Jurić, M. [2004]. Nature 429, 275-277; Willman, M., Jedicke, R., Nesvorny, D., Moskovitz, N., Ivezić, Ž., Fevig, R. [2008]. Icarus 195, 663-673. We used a sample of 95 S-complex asteroids from SMASS and obtained their absolute magnitudes and u, g, r, i, z filter magnitudes from SDSS. The absolute magnitudes yield a size-derived age distribution. The u, g, r, i, z filter magnitudes lead to the principal component color which yields a color-derived age distribution by inverting our color-age relationship, an enhanced version of the 'dual τ' space weathering model of Willman et al. (2010). We fit the size-age distribution to the enhanced dual τ model and found characteristic weathering and gardening times of τw = 2050 ± 80 Myr and τg=4400-500+700Myr respectively. The fit also suggests an initial principal component color of -0.05 ± 0.01 for fresh asteroid surface with a maximum possible change of the probable color due to weathering of Δ PC = 1.34 ± 0.04. Our predicted color of fresh asteroid surface matches the color of fresh ordinary chondritic surface of PC1 = 0.17 ± 0.39.

  11. Chlorine decay in drinking-water transmission and distribution systems: pipe service age effect.

    PubMed

    Al-Jasser, A O

    2007-01-01

    Water quality can deteriorate in the transmission and distribution system beyond the treatment plant. Minimizing the potential for biological regrowth can be attained by chlorinating the finished water. While flowing through pipes, the chlorine concentration decreases for different reasons. Reaction with the pipe material itself and the reaction with both the biofilm and tubercles formed on the pipe wall are known as pipe wall demand, which may vary with pipe parameters. The aim of this paper was to assess the impact of the service age of pipes on the effective chlorine wall decay constant. Three hundred and two pipe sections of different sizes and eight different pipe materials were collected and tested for their chlorine first-order wall decay constants. The results showed that pipe service age was an important factor that must not be ignored in some pipes such as cast iron, steel, cement-lined ductile iron (CLDI), and cement-lined cast iron (CLCI) pipes especially when the bulk decay is not significant relative to the wall decay. For the range of the 55 years of pipe service age used in this study, effective wall decay constants ranged from a decrease by -92% to an increase by +431% from the corresponding values in the recently installed pipes. The effect of service age on the effective wall decay constants was most evident in cast iron pipes, whereas steel pipes were less affected. Effective chlorine wall decay for CLCI and CLDI pipes was less affected by service age as compared to steel and cast iron pipes. Chlorine wall decay constants for PVC, uPVC, and polyethylene pipes were affected negatively by pipe service age and such effect was relatively small.

  12. Age distribution, polyps and rectal cancer in the Egyptian population-based cancer registry

    PubMed Central

    Veruttipong, Darlene; Soliman, Amr S; Gilbert, Samuel F; Blachley, Taylor S; Hablas, Ahmed; Ramadan, Mohamed; Rozek, Laura S; Seifeldin, Ibrahim A

    2012-01-01

    AIM: To describe the clinical and epidemiologic profiles of the disease and to compare the findings with those generated from the previous hospital-based studies. METHODS: The Gharbiah cancer registry is the only population-based cancer registry in Egypt since 1998. We analyzed the data of all colorectal cancer patients included in the registry for the period of 1999-2007. All medical records of the 1364 patients diagnosed in Gharbiah during the study period were retrieved and the following information abstracted: age, residence, diagnosis date, grade, stage, topology, clinical characteristics, and histology variables. Egyptian census data for 1996 and 2006 were used to provide the general population’s statistics on age, sex, residence and other related demographic factors. In addition to age- and sex-specific incidence rate analyses, we analyze the data to explore the incidence distribution by rural-urban differences among the 8 districts of the province. We also compared the incidence rates of Gharbiah to the rates of the Surveillance Epidemiology and End Results (SEER) data of the United States. RESULTS: Over the 9 year-period, 1364 colorectal cancer cases were included. The disease incidence under age 40 years was relatively high (1.3/105) while the incidence in the age groups 40 and over was very low (12.0/105, 19.4/105 and 21.2/105 in the age groups 40-59 years, 60-69 years and > 70 years, respectively). The vast majority of tumors (97.2%) had no polyps and 37.2% of the patients presented with primary lesions in the rectum. Colorectal cancer was more common in patients from urban (55%) than rural (45%) areas. Regional differences in colon and rectal cancer incidence in the 8 districts of the study province may reflect different etiologic patterns in this population. The registry data of Egypt shows a slightly higher incidence of colorectal cancer than the United States in subjects under age 40 years. The results also shows significantly lower incidence of

  13. The Old Imbrium Hypothesis. [revision for KREEP materials formation age and distribution

    NASA Technical Reports Server (NTRS)

    Schonfeld, E.; Meyer, C., Jr.

    1973-01-01

    It is proposed that the order of lunar events was such that the Imbrium event predates the formation of the lunar rock type called KREEP. This hypothesis is used to explain the distribution of KREEP in the regions of Imbrium ejecta and the location of KREEP within the Imbrium and Procellarum mare regions. Model ages of KREEP materials have been previously interpreted to mean that their 'formation' age (time of initial extrusion) is about 4.3 to 4.4 AE. Consequently it is suggested that the Imbrium impact was before 4.3 to 4.4 AE rather than at about 3.9 AE, as is currently believed. This Old Imbrium Hypothesis is not yet proven, but seems to be consistent with a large variety of basic lunar observations.

  14. Gender- and Age-Specific REE and REE/FFM Distributions in Healthy Chinese Adults

    PubMed Central

    Cheng, Yu; Yang, Xue; Na, Li-Xin; Li, Ying; Sun, Chang-Hao

    2016-01-01

    Basic data on the resting energy expenditure (REE) of healthy populations are currently rare, especially for developing countries. The aims of the present study were to describe gender- and age-specific REE distributions and to evaluate the relationships among glycolipid metabolism, eating behaviors, and REE in healthy Chinese adults. This cross-sectional survey included 540 subjects (343 women and 197 men, 20–79 years old). REE was measured by indirect calorimetry and expressed as kcal/day/kg total body weight. The data were presented as the means and percentiles for REE and the REE to fat-free mass (FFM) ratio; differences were described by gender and age. Partial correlation analysis was used to analyze the correlations between REE, tertiles of REE/FFM, and glycolipid metabolism and eating behaviors. In this study, we confirmed a decline in REE with age in women (p = 0.000) and men (p = 0.000), and we found that men have a higher REE (p = 0.000) and lower REE/FFM (p = 0.021) than women. Furthermore, we observed no associations among glycolipid metabolism, eating behaviors, and REE in healthy Chinese adults. In conclusion, the results presented here may be useful to clinicians and nutritionists for comparing healthy and ill subjects and identifying changes in REE that are related to aging, malnutrition, and chronic diseases. PMID:27598192

  15. The galactic habitable zone and the age distribution of complex life in the Milky Way.

    PubMed

    Lineweaver, Charles H; Fenner, Yeshe; Gibson, Brad K

    2004-01-02

    We modeled the evolution of the Milky Way Galaxy to trace the distribution in space and time of four prerequisites for complex life: the presence of a host star, enough heavy elements to form terrestrial planets, sufficient time for biological evolution, and an environment free of life-extinguishing supernovae. We identified the Galactic habitable zone (GHZ) as an annular region between 7 and 9 kiloparsecs from the Galactic center that widens with time and is composed of stars that formed between 8 and 4 billion years ago. This GHZ yields an age distribution for the complex life that may inhabit our Galaxy. We found that 75% of the stars in the GHZ are older than the Sun.

  16. Lipid and lipoprotein profile in menopausal transition. Effects of hormones, age and fat distribution.

    PubMed

    Berg, G; Mesch, V; Boero, L; Sayegh, F; Prada, M; Royer, M; Muzzio, M L; Schreier, L; Siseles, N; Benencia, H

    2004-04-01

    The behavior of lipoproteins during the menopausal transition and their relationship with sex hormones and body fat distribution is still unclear. Our aim was to evaluate atherogenic IDL, LDL, Lp(a) and antiatherogenic HDL lipoproteins in four groups of women: premenopausal (n = 20), menopausal transition women with menstrual bleeding (n = 31), menopausal transition women with 3 to 6 months amenorrhea (n = 36), and postmenopausal women (n = 30). We also measured their FSH, LH and estradiol levels along with BMI and waist circumference. Menopausal transition and postmenopausal women showed higher values of waist circumference (p < 0.0032), LDL-cholesterol (p < 0.002), IDL-cholesterol (p < 0.002) and apoprotein B (p < 0.0001) than premenopausal women. Total-cholesterol (p < 0.0001), triglycerides (p < 0.004), IDL-cholesterol and Lp(a) were higher in menopausal transition women with amenorrhea and in postmenopausal women in comparison with premenopausal women. After adjustment according to age and waist circumference, multiple regression analysis showed the increase in total-cholesterol and LDL-cholesterol to be linearly associated to menopausal status and estradiol concentration, whereas Lp(a) was only related to menopausal status. Age was found to be an independent variable in relation to apoprotein B concentration changes. The effect of menopausal status on TG levels did not remain in the model when age, waist and BMI were included (beta = 0.05, p = 0.356). HDL-cholesterol levels were the same in all the groups. Menopause, age and the increase in abdominal fat distribution were three independent and significant factors impairing lipoprotein profiles from the beginning of the menopausal transition.

  17. Methods and evaluation of frequency aging in distributed-feedback laser diodes for rubidium atomic clocks

    NASA Astrophysics Data System (ADS)

    Matthey, Renaud; Affolderbach, Christoph; Mileti, Gaetano

    2011-09-01

    Distributed-feedback laser diodes emitting at 780nm have been evaluated, with respect to the aging of the injection current required for reaching the rubidium D2 resonance line. Results obtained for lasers operating in air and in vacuum for 9 months are reported. When operated at constant temperature, the laser current required for emission at the wavelength of the desired atomic resonance is found to decrease by 50 to 80μA per month. The impact of this result on the lifetime and long-term performances of laser-pumped rubidium atomic clocks is discussed.

  18. Methods and evaluation of frequency aging in distributed-feedback laser diodes for rubidium atomic clocks.

    PubMed

    Matthey, Renaud; Affolderbach, Christoph; Mileti, Gaetano

    2011-09-01

    Distributed-feedback laser diodes emitting at 780 nm have been evaluated, with respect to the aging of the injection current required for reaching the rubidium D2 resonance line. Results obtained for lasers operating in air and in vacuum for 9 months are reported. When operated at constant temperature, the laser current required for emission at the wavelength of the desired atomic resonance is found to decrease by 50 to 80 μA per month. The impact of this result on the lifetime and long-term performances of laser-pumped rubidium atomic clocks is discussed.

  19. Mapping for maternal and newborn health: the distributions of women of childbearing age, pregnancies and births

    PubMed Central

    2014-01-01

    Background The health and survival of women and their new-born babies in low income countries has been a key priority in public health since the 1990s. However, basic planning data, such as numbers of pregnancies and births, remain difficult to obtain and information is also lacking on geographic access to key services, such as facilities with skilled health workers. For maternal and newborn health and survival, planning for safer births and healthier newborns could be improved by more accurate estimations of the distributions of women of childbearing age. Moreover, subnational estimates of projected future numbers of pregnancies are needed for more effective strategies on human resources and infrastructure, while there is a need to link information on pregnancies to better information on health facilities in districts and regions so that coverage of services can be assessed. Methods This paper outlines demographic mapping methods based on freely available data for the production of high resolution datasets depicting estimates of numbers of people, women of childbearing age, live births and pregnancies, and distribution of comprehensive EmONC facilities in four large high burden countries: Afghanistan, Bangladesh, Ethiopia and Tanzania. Satellite derived maps of settlements and land cover were constructed and used to redistribute areal census counts to produce detailed maps of the distributions of women of childbearing age. Household survey data, UN statistics and other sources on growth rates, age specific fertility rates, live births, stillbirths and abortions were then integrated to convert the population distribution datasets to gridded estimates of births and pregnancies. Results and conclusions These estimates, which can be produced for current, past or future years based on standard demographic projections, can provide the basis for strategic intelligence, planning services, and provide denominators for subnational indicators to track progress. The datasets

  20. A partial exponential lumped parameter model to evaluate groundwater age distributions and nitrate trends in long-screened wells

    NASA Astrophysics Data System (ADS)

    Jurgens, Bryant C.; Böhlke, J. K.; Kauffman, Leon J.; Belitz, Kenneth; Esser, Bradley K.

    2016-12-01

    A partial exponential lumped parameter model (PEM) was derived to determine age distributions and nitrate trends in long-screened production wells. The PEM can simulate age distributions for wells screened over any finite interval of an aquifer that has an exponential distribution of age with depth. The PEM has 3 parameters - the ratio of saturated thickness to the top and bottom of the screen and mean age, but these can be reduced to 1 parameter (mean age) by using well construction information and estimates of the saturated thickness. The PEM was tested with data from 30 production wells in a heterogeneous alluvial fan aquifer in California, USA. Well construction data were used to guide parameterization of a PEM for each well and mean age was calibrated to measured environmental tracer data (3H, 3He, CFC-113, and 14C). Results were compared to age distributions generated for individual wells using advective particle tracking models (PTMs). Age distributions from PTMs were more complex than PEM distributions, but PEMs provided better fits to tracer data, partly because the PTMs did not simulate 14C accurately in wells that captured varying amounts of old groundwater recharged at lower rates prior to groundwater development and irrigation. Nitrate trends were simulated independently of the calibration process and the PEM provided good fits for at least 11 of 24 wells. This work shows that the PEM, and lumped parameter models (LPMs) in general, can often identify critical features of the age distributions in wells that are needed to explain observed tracer data and nonpoint source contaminant trends, even in systems where aquifer heterogeneity and water-use complicate distributions of age. While accurate PTMs are preferable for understanding and predicting aquifer-scale responses to water use and contaminant transport, LPMs can be sensitive to local conditions near individual wells that may be inaccurately represented or missing in an aquifer-scale flow model.

  1. A partial exponential lumped parameter model to evaluate groundwater age distributions and nitrate trends in long-screened wells

    USGS Publications Warehouse

    Jurgens, Bryant; Böhlke, John Karl; Kauffman, Leon J.; Belitz, Kenneth; Esser, Bradley K.

    2016-01-01

    A partial exponential lumped parameter model (PEM) was derived to determine age distributions and nitrate trends in long-screened production wells. The PEM can simulate age distributions for wells screened over any finite interval of an aquifer that has an exponential distribution of age with depth. The PEM has 3 parameters – the ratio of saturated thickness to the top and bottom of the screen and mean age, but these can be reduced to 1 parameter (mean age) by using well construction information and estimates of the saturated thickness. The PEM was tested with data from 30 production wells in a heterogeneous alluvial fan aquifer in California, USA. Well construction data were used to guide parameterization of a PEM for each well and mean age was calibrated to measured environmental tracer data (3H, 3He, CFC-113, and 14C). Results were compared to age distributions generated for individual wells using advective particle tracking models (PTMs). Age distributions from PTMs were more complex than PEM distributions, but PEMs provided better fits to tracer data, partly because the PTMs did not simulate 14C accurately in wells that captured varying amounts of old groundwater recharged at lower rates prior to groundwater development and irrigation. Nitrate trends were simulated independently of the calibration process and the PEM provided good fits for at least 11 of 24 wells. This work shows that the PEM, and lumped parameter models (LPMs) in general, can often identify critical features of the age distributions in wells that are needed to explain observed tracer data and nonpoint source contaminant trends, even in systems where aquifer heterogeneity and water-use complicate distributions of age. While accurate PTMs are preferable for understanding and predicting aquifer-scale responses to water use and contaminant transport, LPMs can be sensitive to local conditions near individual wells that may be inaccurately represented or missing in an aquifer-scale flow model.

  2. Size frequency distribution of Martian craters and relative age of light and dark terrains.

    NASA Technical Reports Server (NTRS)

    Woronow, A.; King, E. A., Jr.

    1972-01-01

    Light and dark terrains in and around Meridiani Sinus, mapped on the imagery from Mariner 6 and Mariner 7, were found to have significantly different cumulative size frequency distributions of craters. The light terrain on a mosaic of frames 6N11, 6N13, and 6N19 has a greater proportion of large craters and a lesser proportion of smaller craters than the dark terrain on the same frames. The light terrain is interpreted to be generally older than the dark terrain. The filling or partial filling of the smaller craters on the light terrain by surface detritus is suggested. Several wide-angle frames have remarkably similar cumulative crater size frequency distributions that may be representative of a large portion of the Martian surface.

  3. Temperature, age and crust thickness distributions of Loki Patera on Io: implications for resurfacing mechanism

    NASA Technical Reports Server (NTRS)

    Davies, A. G.

    2003-01-01

    A high-spatial-resolution, multi-wavelength observation by the Galileo NIMS instrument has been analysed to determine the temperature and area distribution of a large portion of the ionian volcano Loki Patera. The temperatures of the cooler components from a two-temperature fit to the data can be used to determine ages of the surface. The age of the floor along a profile across the floor of the caldera ranges from 10 to 80 days. This puts the start of the resurfacing in July/early August 2001, yielding a resurfacing rate of approximately 1 km/day, with the new lava spreading from the SW corner of the caldera in a NE direction. This rate is consistent with resurfacing by foundering of the crust on a lava lake. However,the temperature distribution may also result from the emplacement of flows. Implied crust thicknesses (derived using a lava cooling model) range from 2.6 to 0.9 m.

  4. Distribution pattern and the risks of OPCs, PHAs and PCBs in aged refuses from landfill.

    PubMed

    Lou, Ziyang; Li, Anding; Tai, Jun; Yuan, Wenxiang; Zhu, Nanwen; Zhao, Youcai

    2016-09-01

    Persistent organic pollutants (POPs) are the urgent risk for landfill, and should be considered before the landfill reclamation and resource. In this work, the distribution pattern of selected POPs in landfill and their ecological risks were investigated and assessed. The Σ20OCPs, Σ16PAHs and Σ19PCBs were around 157.4-329.2, 4103-19,190, and 79.1-340.3μgkg(-1) in aged refuses, with the mean value of 206.6, 8645.4, and 155.1μgkg(-1). While those in soil covers were only 6.3-75.4, 125.5-515.3 and 2.6-43.4μgkg(-1), with the mean value of 33.7, 257.7, and 24.0μgkg(-1), respectively. The maximum OPCs, PHAs and PCBs were in aged refuse with 13, 7, 10 disposal years. Whereas, the corresponding top content in soil covers were in 10, 13 and 16years, meaning that aged refuses were not the direct source for soil covers. Among 20 OCPs measured, α-HCH, δ-HCH, Dieldrin, and Endrin were presented in all aged refuses, with the mean concentration of 93.6, 52.1, 3.9 and 4.7μgkg(-1), respectively. For PAHs, PHE, FLU and PYR were the main composition, and reached to 1535, 1224, 1187μgkg(-1). The Σ7CarPAHs occupied around 33.3-49.9% of total Σ16PAHs tested, and could be used as the indictor for PAHs pollutant in landfill. PCB-5 content was around 40.7-263.3μgkg(-1) in aged refuses, and occupied around 51.5-81.8% of Σ19PCBs measured. The HCHs and DDTs in aged refuses were below the national standard GB15618-1995, and the corresponding Σ19PCBs concentrations met the standard of GB 13015-91, suggesting that aged refuse are accepted for the further utilization process.

  5. A mitochondrial location for haemoglobins--dynamic distribution in ageing and Parkinson's disease.

    PubMed

    Shephard, Freya; Greville-Heygate, Oliver; Marsh, Oliver; Anderson, Susan; Chakrabarti, Lisa

    2014-01-01

    Haemoglobins are iron-containing proteins that transport oxygen in the blood of most vertebrates. The mitochondrion is the cellular organelle which consumes oxygen in order to synthesise ATP. Mitochondrial dysfunction is implicated in neurodegeneration and ageing. We find that α and β haemoglobin (Hba and Hbb) proteins are altered in their distribution in mitochondrial fractions from degenerating brain. We demonstrate that both Hba and Hbb are co-localised with the mitochondrion in mammalian brain. The precise localisation of the Hbs is within the inner membrane space and associated with inner mitochondrial membrane. Relative mitochondrial to cytoplasmic ratios of Hba and Hbb show changing distributions of these proteins during the process of neurodegeneration in the pcd(5j) mouse brain. A significant difference in mitochondrial Hba and Hbb content in the mitochondrial fraction is seen at 31 days after birth, this corresponds to a stage when dynamic neuronal loss is measured to be greatest in the Purkinje Cell Degeneration mouse. We also report changes in mitochondrial Hba and Hbb levels in ageing brain and muscle. Significant differences in mitochondrial Hba and Hbb can be seen when comparing aged brain to muscle, suggesting tissue specific functions of these proteins in the mitochondrion. In muscle there are significant differences between Hba levels in old and young mitochondria. To understand whether the changes detected in mitochondrial Hbs are of clinical significance, we examined Parkinson's disease brain, immunohistochemistry studies suggest that cell bodies in the substantia nigra accumulate mitochondrial Hb. However, western blotting of mitochondrial fractions from PD and control brains indicates significantly less Hb in PD brain mitochondria. One explanation could be a specific loss of cells containing mitochondria loaded with Hb proteins. Our study opens the door to an examination of the role of Hb function, within the context of the mitochondrion

  6. Ages, distributions, and origins of upland coastal dune sheets in Oregon, USA

    USGS Publications Warehouse

    Peterson, C.D.; Stock, E.; Price, D.M.; Hart, R.; Reckendorf, F.; Erlandson, J.M.; Hostetler, S.W.

    2007-01-01

    A total of ten upland dune sheets, totaling 245??km in combined length, have been investigated for their origin(s) along the Oregon coast (500??km in length). The ages of dune emplacement range from 0.1 to 103??ka based on radiocarbon (36 samples) and luminescence (46 samples) dating techniques. The majority of the emplacement dates fall into two periods of late-Pleistocene age (11-103??ka) and mid-late-Holocene age (0.1-8??ka) that correspond to marine low-stand and marine high-stand conditions, respectively. The distribution of both the late-Pleistocene dune sheets (516??km2 total surface area) and the late-Holocene dune sheets (184??km2) are concentrated (90% of total surface area) along a 100??km coastal reach of the south-central Oregon coast. This coastal reach lies directly landward of a major bight (Heceta-Perpetua-Stonewall Banks) on the continental shelf, at depths of 30-200??m below present mean sea level (MSL). The banks served to trap northward littoral drift during most of the late-Pleistocene conditions of lowered sea level (- 50 ?? 20??m MSL). The emerged inner-shelf permitted cross-shelf, eolian sand transport (10-50??km distance) by onshore winds. The depocenter sand deposits were reworked by the Holocene marine transgression and carried landward by asymmetric wave transport during early- to mid-Holocene time. The earliest dated onset of Holocene dune accretion occurred at 8??ka in the central Oregon coast. A northward migration of Northeast Pacific storm tracks to the latitude of the shelf depocenter (Stonewall, Perpetua, Heceta Banks) in Holocene time resulted in eastward wave transport from the offshore depocenter. The complex interplay of coastal morphology, paleosea-level, and paleoclimate yielded the observed peak distribution of beach and dune sand observed along the south-central Oregon coast. ?? 2007 Elsevier B.V. All rights reserved.

  7. Aging affects spatial distribution of leg muscle oxygen saturation during ramp cycling exercise.

    PubMed

    Takagi, Shun; Kime, Ryotaro; Murase, Norio; Watanabe, Tsubasa; Osada, Takuya; Niwayama, Masatsugu; Katsumura, Toshihito

    2013-01-01

    We compared muscle oxygen saturation (SmO2) responses in several leg muscles and within a single muscle during ramp cycling exercise between elderly men (n = 8; age, 65 ± 3 years; ELD) and young men (n = 10; age, 23 ± 3 years; YNG). SmO2 was monitored at the distal site of the vastus lateralis (VLd), proximal site of the vastus lateralis (VLp), rectus femoris (RF), vastus medialis (VM), biceps femoris (BF), gastrocnemius lateralis (GL), gastrocnemius medialis (GM), and tibialis anterior (TA) by near-infrared spatial resolved spectroscopy. During submaximal exercise, significantly lower SmO2 at a given absolute work rate was observed in VLd, RF, BF, GL, and TA but not in VLp, VM, and GM in ELD than in YNG. In contrast, at all measurement sites, SmO2 at peak exercise was not significantly different between groups. These results indicate that the effects of aging on SmO2 responses are heterogeneous between leg muscles and also within a single muscle. The lower SmO2 in older men may have been caused by reduced muscle blood flow or altered blood flow distribution.

  8. Genotype-phenotype relationship for localization and age distribution of telangiectases in hereditary hemorrhagic telangiectasia.

    PubMed

    Letteboer, Tom G W; Mager, Hans-Jurgen; Snijder, Repke J; Lindhout, Dick; Ploos van Amstel, Hans-Kristian; Zanen, Pieter; Westermann, Kees J J

    2008-11-01

    Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by arteriovenous malformations (AVMs) ranging from telangiectases to larger AVMs. Mutations in two genes cause HHT; ENG (HHT1) and ACVRL1 (HHT2). Although the hallmark for clinical diagnosis is the presence of telangiectases, there are few publications reporting the relative distribution and frequency of these features between HHT1 and HHT2. Here, the results of such analysis of telangiectases in 268 patients with HHT1 and 130 patients with HHT2 are described. Localization of the telangiectases is reported, and patients were clustered by age to estimate the site prevalence for different age categories. We show that telangiectases of the nasal mucosa are present at a higher prevalence and start to appear earlier in life than those of the oral mucosa or dermal sites in patients with either HHT1 or HHT2. Oral and nasal mucosal telangiectases are present earlier in life in patients with HHT1 compared to patients with HHT2, whereas dermal lesions are more frequent and appear earlier in life in patients with HHT2. In patients with either HHT1 or HHT2, the number of sites affected increases with age. In patients with HHT1, more women than men had skin telangiectases, particularly on the face. These results confirm that the frequency of AVMs differ between patients with HHT1 and HHT2, and that these differences can be detected on physical examination.

  9. Propagated but Topologically Distributed Forebrain Neurons Expressing Alpha-Synuclein in Aged Macaques

    PubMed Central

    Kimura, Katsuo; Inoue, Ken-ichi; Kuroiwa, Yoshiyuki; Tanaka, Fumiaki; Takada, Masahiko

    2016-01-01

    In neurodegenerative disorders, such as Parkinson's disease (PD), alpha-synuclein (α-syn) accumulates to induce cell death and/or form a cytoplasmic inclusion called Lewy body (LB). This α-syn-related pathology is termed synucleinopathy. It remains unclear how α-syn accumulation expands during the progress of synucleinopathy in the human brain. In our study, we investigated the patterns of distribution and propagation of forebrain neurons expressing α-syn in aged macaques. It was found that the occurrence of α-syn-positive neurons proceeded topologically based on the midbrain dopamine pathways arising from the substantia nigra and the ventral tegmental area where they were primarily observed. In the nigrostriatal or mesolimbic dopamine pathway, the age-dependent increase in α-syn-positive neurons was evident in the striatum or the nucleus accumbens, respectively. Concerning the nigrostriatal pathway, a mediolateral or rostrocaudal gradient was seen in the substantia nigra or the striatum, respectively, and a compensatory increase in dopamine transporter occurred in the striatum regardless of the decreased dopamine level. In the mesocortical dopamine pathway, α-syn-positive neurons appeared in the prefrontal and then motor areas of the frontal lobe. Given that neither LB formation nor clinical phenotype manifestation was detected in any of the monkeys examined in the present study, aged macaques may be useful as a potential presymptomatic model for PD and LB-related neuropsychiatric disorders. PMID:27861638

  10. Age-dependent chromosomal distribution of male-biased genes in Drosophila.

    PubMed

    Zhang, Yong E; Vibranovski, Maria D; Krinsky, Benjamin H; Long, Manyuan

    2010-11-01

    We investigated the correlation between the chromosomal location and age distribution of new male-biased genes formed by duplications via DNA intermediates (DNA-level) or by de novo origination in Drosophila. Our genome-wide analysis revealed an excess of young X-linked male-biased genes. The proportion of X-linked male-biased genes then diminishes through time, leading to an autosomal excess of male-biased genes. The switch between X-linked and autosomal enrichment of male-biased genes was also present in the distribution of both protein-coding genes on the D. pseudoobscura neo-X chromosome and microRNA genes of D. melanogaster. These observations revealed that the evolution of male-biased genes is more complicated than the previously detected one-step X→A gene traffic and the enrichment of the male-biased genes on autosomes. The pattern we detected suggests that the interaction of various evolutionary forces such as the meiotic sex chromosome inactivation (MSCI), faster-X effect, and sexual antagonism in the male germline might have shaped the chromosomal distribution of male-biased genes on different evolutionary time scales.

  11. Age-dependent chromosomal distribution of male-biased genes in Drosophila

    PubMed Central

    Zhang, Yong E.; Vibranovski, Maria D.; Krinsky, Benjamin H.; Long, Manyuan

    2010-01-01

    We investigated the correlation between the chromosomal location and age distribution of new male-biased genes formed by duplications via DNA intermediates (DNA-level) or by de novo origination in Drosophila. Our genome-wide analysis revealed an excess of young X-linked male-biased genes. The proportion of X-linked male-biased genes then diminishes through time, leading to an autosomal excess of male-biased genes. The switch between X-linked and autosomal enrichment of male-biased genes was also present in the distribution of both protein-coding genes on the D. pseudoobscura neo-X chromosome and microRNA genes of D. melanogaster. These observations revealed that the evolution of male-biased genes is more complicated than the previously detected one-step X→A gene traffic and the enrichment of the male-biased genes on autosomes. The pattern we detected suggests that the interaction of various evolutionary forces such as the meiotic sex chromosome inactivation (MSCI), faster-X effect, and sexual antagonism in the male germline might have shaped the chromosomal distribution of male-biased genes on different evolutionary time scales. PMID:20798392

  12. ANALYSIS OF AGED IN-HOME CARPETING TO DETERMINE THE DISTRIBUTION OF PESTICIDE RESIDUES BETWEEN DUST, CARPET, AND PAD COMPARTMENTS

    EPA Science Inventory

    This report presents results of a study to determine the distribution of pesticides, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) between dust and carpet components in aged carpeting. Carpeting in eight homes in the Research Triangle Area, which...

  13. Age distribution of passive margins through earth history and tectonic implications

    NASA Astrophysics Data System (ADS)

    Bradley, D. C.

    2007-05-01

    The ages and lifespans of all existing passive (Atlantic-type) margins plus 59 ancient ones were compiled. Passive margins have existed on Earth almost continually since at least 2685 Ma. Their abundance has fluctuated dramatically, and most of the fluctuations have clear tectonic causes. For the past 2200 Ma, the compiled age distribution of passive margins appears to be robust and not an artifact of an incomplete rock record or flaws in the compilation. It closely tracks all the first-order highs and lows of the seawater 87Sr/86Sr curve, which has been derived from utterly independent data. The main features of the age distribution are as follows: (1) A present-day maximum in number and aggregate length of passive margins corresponds to a time of continental dispersal following breakup of Pangea. (2) A 250- 350-Ma minimum corresponds to Pangea's greatest extent. (3) A 500-600-Ma maximum represents a time of continental dispersal following staged breakup from 600 to 1000 Ma of one or more larger continents (Rodinia in most models). (4) Passive margins are rare between 1000 and 1650 Ma, and none are known at all between 1650 and 1750 Ma. This 750-m.y. low in the passive margin record coincides with the heyday of massif anorthosites. Whereas the Mesoproterozoic may have seen few modern-style Wilson Cycles involving the opening and closing of Atlantic-type oceans, it nonetheless was a time of plate tectonics involving subduction and collision (e.g., Grenville orogeny). (5) Passive margins were abundant between 1750 to 2250 Ma. The close of this interval at 1750-1800 Ma was marked by the collisional assembly of Laurentia, Baltica, and other cratons, which may have been part of a supercontinent (Columbia in some models). A maximum at 1850-2050 Ma corresponds to a time of dispersed small continents. (6) The record of passive margins before 2250 Ma is patchy. It definitely extends back to 2685 Ma (Kaapvaal craton, W margin), and possibly to about 3000 Ma. For all but a

  14. Submarine Landslides along the U.S. Atlantic Margin: Their Distribution, Failure Processes, and Age

    NASA Astrophysics Data System (ADS)

    Chaytor, J. D.; ten Brink, U. S.; Twichell, D. C.; Baxter, C. D.; Hallam, T. D.; Brothers, D. S.

    2011-12-01

    We have investigated the size, distribution, failure mode, and age of submarine landslides on the seafloor along the U.S. Atlantic continental slope and rise, using near-complete multibeam bathymetry coverage, together with new and existing seismic reflection, core, and photographic data sets. These data show that open-slope and canyon-related landslides are ubiquitous features of the continental margin and in places have been a dominant mechanism of downslope sediment transport and slope-rise modification. Retrogressive and translational mechanisms are prevailing modes of failure, although earth-flows, rare in the marine realm, are present along seafloor gradients of less than 1o on the upper rise. Individual and composite open-slope landslides with scar dimensions that exceed 900 km2 in area and 100 km3 in volume and deposit run-out distances greater than 200 km are present off Georges Bank (Munson-Nygren-Retriever complex), southern New England, Cape Hatteras (Currituck and Cape Lookout landslides), and the Blake Plateau (Cape Fear landslide). While dating of several landslides along the margin suggests a link to mechanisms driven by environmental changes at the end of the Last Glacial Maximum, the ages of the majority of the observed landslides are still unknown. In an effort to address the scarcity of age information required to investigate failure process and geohazards, we are utilizing both absolute (radiocarbon and oxygen isotope) and relative dating techniques. Radiocarbon dating of shallow water mollusks from recently collected piston cores in landslide scars and debris deposits offshore of southern New England record multiple landslide events over the last 50,000 years originating from both the continental slope and upper rise. Relative ages of landslide features are obtained from cross-cutting relationships between canyons and landslide scars and related mass-transport deposits.

  15. Age and height distribution of holocene transgressive deposits in eastern North Island, New Zealand

    USGS Publications Warehouse

    Ota, Y.; Berryman, K.R.; Hull, A.G.; Miyauchi, T.; Iso, N.

    1988-01-01

    Holocene transgressive deposits are frequently exposed near the present-day coastline of the study area along eastern North Island, New Zealand. They occur in sites of former estuaries that were filled during the postglacial rise in sea level. We present one hundred radiocarbon dates of Holocene transgressive deposits from the study area, ranging in age from ca. 10,000 to 5500 yr B.P. Relative sea level curves up to ca. 6000 yr B.P. were reconstructed for six locations. The curves have similar slopes prior to about 7000 yr B.P., indicating that sea level rise was much more rapid than any tectonic uplift at that time. The postglacial rise in sea level in New Zealand is considered, in general, to have culminated at about 6500 yr B.P. but the upper limit ages of transgressive deposits in our study area vary from ca. 5500 to 7000 yr B.P. At sites where the uplift rate is high the postglacial transgression culminated rather earlier than ca. 6500 yr B.P., and at sites where there is subsidence or there is very low uplift the culmination is later than ca. 6500 yr B.P. Nine of fourteen dates from fossil trees in growth position, that grew in and were buried by estuarine silt, cluster in the age range ca. 8000-8400 yr B.P. These data support the view that there was a minor regression or stillstand in the eustatic sea level rise at that time. Eleven tectonic subregions are recognized in the study area on the basis of average uplift rate. Most of these subregions coincide with those established from the number and ages of younger Holocene marine terraces of probable coseismic origin. ?? 1988.

  16. Age distribution and seasonal dynamics of abomasal helminths in wild red deer from central Spain.

    PubMed

    Santín-Durán, Mónica; Alunda, José M; Hoberg, Eric P; de la Fuente, Concepción

    2008-10-01

    A study on age distribution and seasonal dynamics of abomasal helminths in wild red deer was conducted in central Spain, by monthly samplings of fawns (<1 yr), subadult (1-2 yr), and adult (>2 yr) animals. Both intensity and prevalence of abomasal parasitism were higher in older animals, particularly in males. A bimodal pattern for intensity of infection by gastrointestinal parasites was observed. Maximum values attained in winter and summer may be related to variation in climate and the shifting availability of forage resources. The pattern was largely due to the contribution of Spiculopteragia asymmetrica/Spiculopteragia quadrispiculata, whereas the other species found (Ostertagia leptospicularis/Ostertagia kolchida and Ostertagia drozdzi/Ostertagia ryjikovi) occurred with lower prevalence and intensity of infection. Among these ostertagiines, the ratio for major and minor morphotypes of males of respective species and the relative abundance of males and females were stable through the annual cycle.

  17. Estimation of demographic measures for India, 1881-1961, based on census age distributions.

    PubMed

    Das Gupta, P

    1971-11-01

    Abstract India is one of the very few developing countries which have a relatively long history of population censuses. The first census was taken in 1872, the second in 1881 and since then there has been a census every ten years, the latest in 1971. Yet the registration of births and deaths in India, even at the present time, is too inadequate to be of much help in estimating fertility and mortality conditions in the country. From time to time Indian census actuaries have indirectly constructed life tables by comparing one census age distribution with the preceding one. Official life tables are available for all the decades from 1872-1881 to 1951-1961, except for 1911-1921 and 1931-1941. Kingsley Davis(1) filled in the gap by constructing life tables for the latter two decades. He also estimated the birth and death rates ofIndia for the decades from 1881-1891 to 1931-1941. Estimates of these rates for the following two decades, 1941-1951 and 1951-1961, were made by Indian census actuaries. The birth rates of Davis and the Indian actuaries were obtained basically by the reverse survival method from the age distribution and the computed life table of the population. Coale and Hoover(2), however, estimated the birth and death rates and the life table of the Indian population in 1951 by applying stable population theory. The most recent estimates of the birth rate and death rate for 1963-1964 are based on the results of the National Sample Survey. All these estimates are presented in summary form in Table 1.

  18. Cost-effective age structure and geographical distribution of boreal forest reserves.

    PubMed

    Lundström, Johanna; Ohman, Karin; Perhans, Karin; Rönnqvist, Mikael; Gustafsson, Lena; Bugman, Harald

    2011-02-01

    1. Forest reserves are established to preserve biodiversity, and to maintain natural functions and processes. Today there is heightened focus on old-growth stages, with less attention given to early successional stages. The biodiversity potential of younger forests has been overlooked, and the cost-effectiveness of incorporating different age classes in reserve networks has not yet been studied.2. We performed a reserve selection analysis in boreal Sweden using the Swedish National Forest Inventory plots. Seventeen structural variables were used as biodiversity indicators, and the cost of protecting each plot as a reserve was assessed using the Heureka system. A goal programming approach was applied, which allowed inclusion of several objectives and avoided a situation in which common indicators affected the result more than rare ones. The model was limited either by budget or area.3. All biodiversity indicators were found in all age classes, with more than half having the highest values in ages ≥ 100 years. Several large-tree indicators and all deadwood indicators had higher values in forests 0-14 years than in forests 15-69 years.4. It was most cost-effective to protect a large proportion of young forests since they generally have a lower net present value compared to older forests, but still contain structures of importance for biodiversity. However, it was more area-effective to protect a large proportion of old forests since they have a higher biodiversity potential per area.5. The geographical distribution of reserves selected with the budget-constrained model was strongly biassed towards the north-western section of boreal Sweden, with a large proportion of young forest, whereas the area-constrained model focussed on the south-eastern section, with dominance by the oldest age class.6.Synthesis and applications. We show that young forests with large amounts of structures important to biodiversity such as dead wood and remnant trees are cheap and cost

  19. Cost-effective age structure and geographical distribution of boreal forest reserves

    PubMed Central

    Lundström, Johanna; Öhman, Karin; Perhans, Karin; Rönnqvist, Mikael; Gustafsson, Lena; Bugman, Harald

    2011-01-01

    1. Forest reserves are established to preserve biodiversity, and to maintain natural functions and processes. Today there is heightened focus on old-growth stages, with less attention given to early successional stages. The biodiversity potential of younger forests has been overlooked, and the cost-effectiveness of incorporating different age classes in reserve networks has not yet been studied. 2. We performed a reserve selection analysis in boreal Sweden using the Swedish National Forest Inventory plots. Seventeen structural variables were used as biodiversity indicators, and the cost of protecting each plot as a reserve was assessed using the Heureka system. A goal programming approach was applied, which allowed inclusion of several objectives and avoided a situation in which common indicators affected the result more than rare ones. The model was limited either by budget or area. 3. All biodiversity indicators were found in all age classes, with more than half having the highest values in ages ≥ 100 years. Several large-tree indicators and all deadwood indicators had higher values in forests 0–14 years than in forests 15–69 years. 4. It was most cost-effective to protect a large proportion of young forests since they generally have a lower net present value compared to older forests, but still contain structures of importance for biodiversity. However, it was more area-effective to protect a large proportion of old forests since they have a higher biodiversity potential per area. 5. The geographical distribution of reserves selected with the budget-constrained model was strongly biassed towards the north-western section of boreal Sweden, with a large proportion of young forest, whereas the area-constrained model focussed on the south-eastern section, with dominance by the oldest age class. 6. Synthesis and applications. We show that young forests with large amounts of structures important to biodiversity such as dead wood and remnant trees are cheap and

  20. Red Cell Distribution Width and the Risk of Death in Middle-aged and Older Adults

    PubMed Central

    Patel, Kushang V.; Ferrucci, Luigi; Ershler, William B.; Longo, Dan L.; Guralnik, Jack M.

    2009-01-01

    Background Red cell distribution width (RDW), a component of an electronic complete blood count, is a measure of heterogeneity in the size of circulating erythrocytes. In patients with symptomatic cardiovascular disease (CVD), RDW is associated with mortality. However, it has not been demonstrated that RDW is a predictor of mortality independent of nutritional deficiencies or in the general population. Methods RDW was measured in a national sample of 8175 community-dwelling adults aged 45 and older who participated in the 1988–1994 National Health and Nutrition Examination Survey; mortality follow-up occurred through December 31, 2000. Deaths from all causes, CVD, cancer, and other causes were examined as a function of RDW. Results Higher RDW values were strongly associated with an increased risk of death. Compared to the lowest quintile of RDW, the following were adjusted hazard ratios (HR) for all-cause mortality (and 95 percent confidence intervals): second quintile, 1.1 (0.9–1.3); third quintile, 1.2 (1.0–1.4); fourth quintile, 1.4 (1.2–1.8); fifth quintile, 2.1 (1.7–2.6). For every 1 percent increment in RDW, all-cause mortality risk increased by 22% [HR = 1.22 (1.15–1.30); p<0.001]. Even when analyses were restricted to non-anemic participants or to those in the normal range of RDW (11–15%) without iron, folate, or vitamin B12 deficiency, RDW remained strongly associated with mortality. The prognostic effect of RDW was observed in both middle-aged and older adults for multiple causes of death. Conclusions RDW is a widely-available test that is a strong predictor of mortality in the general population of adults aged 45 and older. PMID:19273783

  1. ADNP: A major autism mutated gene is differentially distributed (age and gender) in the songbird brain.

    PubMed

    Hacohen Kleiman, Gal; Barnea, Anat; Gozes, Illana

    2015-10-01

    ADNP is a protein necessary for brain development, important for brain plasticity, cognitive and social functioning, characteristics that are all impaired in autism and in the Adnp(+/-) mouse model, in a sex-dependent manner. ADNP was originally discovered as a protein that is secreted from glial cells in response to vasoactive intestinal peptide (VIP). VIP is a major neuroprotective peptide in the CNS and PNS and was also associated with social recognition in rodents and aggression, pair-bonding and parental behaviors in birds. Comparative sequence alignment revealed high evolutionary conservation of ADNP in Chordata. Despite its importance in brain function, ADNP has never been studied in birds. Zebra finches (Taeniopygia guttata) are highly social songbirds that have a sexually dichotomous anatomical brain structure, with males demonstrating a developed song system, presenting a model to study behavior and potential sexually dependent fundamental differences. Here, using quantitative real time polymerase chain reaction (qRT-PCR), we discovered sexually dichotomous and age related differences in ADNP mRNA expression in three different regions of the song bird brain-cerebellum, cerebrum, and brain stem. Higher levels of ADNP mRNA were specifically found in young male compared to the female cerebrum, while aging caused a significant 2 and 3-fold decrease in the female and male cerebrum, respectively. Furthermore, a comparison between the three tested brain regions revealed unique sex-dependent ADNP mRNA distribution patterns, affected by aging. Future studies are aimed at deciphering the function of ADNP in birds, toward a better molecular understanding of sexual dichotomy in singing behavior in birds.

  2. Kilauea summit overflows: Their ages and distribution in the Puna District, Hawai'i

    USGS Publications Warehouse

    Clague, D.A.; Hagstrum, J.T.; Beeson, M.H.; Champion, D.E.

    1999-01-01

    The tube-fed pahoehoe lava flows covering much of the northeast flank of Kilauea Volcano are named the 'Aila'au flows. Their eruption age, based on published and six new radiocarbon dates, is approximately AD 1445. The flows have distinctive paleomagnetic directions with steep inclinations (40??-50??) and easterly declinations (0??-10??E). The lava was transported ~40 km from the vent to the coast in long, large-diameter lava tubes; the longest tube (Kazumura Cave) reaches from near the summit to within several kilometers of the coast near Kaloli Point. The estimated volume of the 'Aila'au flow field is 5.2 ?? 0.8 km3, and the eruption that formed it probably lasted for approximately 50 years. Summit overflows from Kilauea may have been nearly continuous between approximately AD 1290 and 1470, during which time a series of shields formed at and around the summit. The 'Aila'au shield was either the youngest or the next to youngest in this series of shields. Site-mean paleomagnetic directions for lava flows underlying the 'Aila'au flows form only six groups. These older pahoehoe flows range in age from 2750 to 2200 years. Lava flows from most of these summit eruptions also reached the coast, but none appears as extensive as the 'Aila'au flow field. The chemistry of the melts erupted during each of these summit overflow events is remarkably similar, averaging approximately 6.3 wt.% MgO near the coast and 6.8 wt.% MgO near the summit. The present-day caldera probably formed more recently than the eruption that formed the 'Aila'au flows (estimated termination ca. AD 1470). The earliest explosive eruptions that formed the Keanakako'i Ash, which is stratigraphically above the 'Aila'au flows, cannot be older than this age.

  3. Ground water age and nitrate distribution within a glacial aquifer beneath a thick unsaturated zone

    USGS Publications Warehouse

    Johnston, C.T.; Cook, P.G.; Frape, S.K.; Plummer, L.N.; Busenberg, E.; Blackport, R.J.

    1998-01-01

    The impact on ground water quality from increasing fertilizer application rates over the past 40 years is evaluated within a glacial aquifer system beneath a thick unsaturated zone. Ground water ages within the aquifer could not be accurately determined from the measured distribution of 3H and as a result, chlorofluorocarbon (CFC) and 3H/3He dating techniques were applied. Beneath a 25 m thick unsaturated zone, ground water ages based on CFC-11 concentrations were greater than 3H/3He ground water ages by 6 to 10 years, due to the time lag associated with the diffusion of CFCs through the unsaturated zone. Using the corrected CFC-11 and 3H/3He ground water ages and the estimated travel time of 3H within the unsaturated zone, the approximate position of ground water recharged since the mid-1960s was determined. Nitrate concentrations within post mid-1960s recharge were generally elevated and near or above the drinking water limit of 10 mg-N/L. In comparison, pre mid-1960s recharge had nitrate concentrations <2.5 mg-N/L. The elevated NO3- concentrations in post mid-1960s recharge are attributed mainly to increasing fertilizer application rates between 1970 and the mid- to late 1980s. Anaerobic conditions suitable for denitrification are present within pre mid-1960s recharge indicating that removal of DO is a slow process taking tens of years. Over the next 10 to 20 years, nitrate concentrations at municipal well fields that are currently capturing aerobic ground water recharged near the mid-1960s are expected to increase because of the higher fertilizer application rates beginning in the 1970s and 1980s.The impact on ground water quality from increasing fertilizer application rates over the past 40 years is evaluated within a glacial aquifer system beneath a thick unsaturated zone. Beneath a 25 m thick unsaturated zone, ground water ages based on CFC-11 concentrations were greater than 3H/3He ground water ages by 6 to 10 years, due to the time lag associated with the

  4. Age and sex distribution of some retinal macular diseases: senile and presenile macular degeneration and central serous retinitis.

    PubMed

    Knave, B; Tengroth, B; Voss, M

    1984-01-01

    The age and sex distribution of senile macular degeneration (SMD) was investigated at the Low Vision Clinic in Stockholm. SMD increased with age and was found to be more common among women than men. This difference was not due to the fact that women live longer than men or related to women consulting ophthalmologists more often than men because of visual handicap. The age and sex distribution of presenile macular degeneration ( PSMD ) and central serous retinitis (CSR) was investigated at the Department of Ophthalmology of Falun Hospital. Also PSMD increased with age and was found to be more common among women than men, even if the sex difference was not as clear as for SMD. CSR was found to be more frequent at younger ages and, contrary to SMD and PSMD , more common among men. The reasons for these sex differences in frequencies of SMD, PSMD and CSR are not known.

  5. The gender similarities hypothesis.

    PubMed

    Hyde, Janet Shibley

    2005-09-01

    The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses support the gender similarities hypothesis. Gender differences can vary substantially in magnitude at different ages and depend on the context in which measurement occurs. Overinflated claims of gender differences carry substantial costs in areas such as the workplace and relationships.

  6. A Bayesian Modeling Approach for Estimation of a Shape-Free Groundwater Age Distribution using Multiple Tracers

    SciTech Connect

    Massoudieh, Arash; Visser, Ate; Sharifi, Soroosh; Broers, Hans Peter

    2013-10-15

    The mixing of groundwaters with different ages in aquifers, groundwater age is more appropriately represented by a distribution rather than a scalar number. To infer a groundwater age distribution from environmental tracers, a mathematical form is often assumed for the shape of the distribution and the parameters of the mathematical distribution are estimated using deterministic or stochastic inverse methods. We found that the prescription of the mathematical form limits the exploration of the age distribution to the shapes that can be described by the selected distribution. In this paper, the use of freeform histograms as groundwater age distributions is evaluated. A Bayesian Markov Chain Monte Carlo approach is used to estimate the fraction of groundwater in each histogram bin. This method was able to capture the shape of a hypothetical gamma distribution from the concentrations of four age tracers. The number of bins that can be considered in this approach is limited based on the number of tracers available. The histogram method was also tested on tracer data sets from Holten (The Netherlands; 3H, 3He, 85Kr, 39Ar) and the La Selva Biological Station (Costa-Rica; SF 6, CFCs, 3H, 4He and 14C), and compared to a number of mathematical forms. According to standard Bayesian measures of model goodness, the best mathematical distribution performs better than the histogram distributions in terms of the ability to capture the observed tracer data relative to their complexity. Among the histogram distributions, the four bin histogram performs better in most of the cases. The Monte Carlo simulations showed strong correlations in the posterior estimates of bin contributions, indicating that these bins cannot be well constrained using the available age tracers. The fact that mathematical forms overall perform better than the freeform histogram does not undermine the benefit of the

  7. A Bayesian Modeling Approach for Estimation of a Shape-Free Groundwater Age Distribution using Multiple Tracers

    DOE PAGES

    Massoudieh, Arash; Visser, Ate; Sharifi, Soroosh; ...

    2013-10-15

    The mixing of groundwaters with different ages in aquifers, groundwater age is more appropriately represented by a distribution rather than a scalar number. To infer a groundwater age distribution from environmental tracers, a mathematical form is often assumed for the shape of the distribution and the parameters of the mathematical distribution are estimated using deterministic or stochastic inverse methods. We found that the prescription of the mathematical form limits the exploration of the age distribution to the shapes that can be described by the selected distribution. In this paper, the use of freeform histograms as groundwater age distributions is evaluated.more » A Bayesian Markov Chain Monte Carlo approach is used to estimate the fraction of groundwater in each histogram bin. This method was able to capture the shape of a hypothetical gamma distribution from the concentrations of four age tracers. The number of bins that can be considered in this approach is limited based on the number of tracers available. The histogram method was also tested on tracer data sets from Holten (The Netherlands; 3H, 3He, 85Kr, 39Ar) and the La Selva Biological Station (Costa-Rica; SF 6, CFCs, 3H, 4He and 14C), and compared to a number of mathematical forms. According to standard Bayesian measures of model goodness, the best mathematical distribution performs better than the histogram distributions in terms of the ability to capture the observed tracer data relative to their complexity. Among the histogram distributions, the four bin histogram performs better in most of the cases. The Monte Carlo simulations showed strong correlations in the posterior estimates of bin contributions, indicating that these bins cannot be well constrained using the available age tracers. The fact that mathematical forms overall perform better than the freeform histogram does not undermine the benefit of the freeform approach, especially for the cases where a larger amount of observed data is

  8. Aging

    PubMed Central

    Park, Dong Choon

    2013-01-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging 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 aging. Despite the efforts from many researchers, the progression and the mechanisms of aging 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 aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  9. Age-specific absolute and relative organ weight distributions for Fischer 344 rats.

    PubMed

    Marino, Dale J

    2012-01-01

    The Fischer 344 (F344) rat has been the standard rat strain used in toxicology studies conducted by the National Cancer Institute (NCI) and the National Toxicology Program (NTP). However, the numerous reports published to date on growth, survival, and tumor incidence have not included an overall compilation of organ weight data. Notably, dose-related organ weight effects are endpoints used by regulatory agencies to develop toxicity reference values (TRVs) for use in human health risk assessments. In addition, physiologically-based pharmacokinetic (PBPK) models, which utilize relative organ weights, are increasingly being used to develop TRVs. Because a compilation of organ weights for F344 rats could prove beneficial for TRV development and PBPK modeling, all available absolute and relative organ weight data for untreated control F344 rats were collected from NCI/NTP feed, drinking-water, and inhalation studies in order to develop age-specific distributions. Results showed that organ weights were collected more frequently at 2-wk (59 studies), 3-mo (148 studies), and 15-mo (38 studies) intervals than at other intervals and more frequently from feeding and inhalation than from drinking-water studies. Liver, right kidney, lung, heart, thymus, and brain weights were most frequently collected. From the collected data, the mean and standard deviation for absolute and relative organ weights were calculated. Findings showed age-related increases in absolute weights and decreases in relative weights for brain, liver, right kidney, lung, heart, thyroid, and right testis. The results suggest a general variability trend in absolute organ weights of brain < right testis < heart < right kidney < liver < lung < thymus < thyroid.

  10. Patterns and age distribution of ground-water flow to streams

    USGS Publications Warehouse

    Modica, E.; Reilly, T.E.; Pollock, D.W.

    1997-01-01

    Simulations of ground-water flow in a generic aquifer system were made to characterize the topology of ground-water flow in the stream subsystem and to evaluate its relation to deeper ground-water flow. The flow models are patterned after hydraulic characteristics of aquifers of the Atlantic Coastal Plain and are based on numerical solutions to three-dimensional, steady-state, unconfined flow. The models were used to evaluate the effects of aquifer horizontal-to-vertical hydraulic conductivity ratios, aquifer thickness, and areal recharge rates on flow in the stream subsystem. A particle tracker was used to determine flow paths in a stream subsystem, to establish the relation between ground-water seepage to points along a simulated stream and its source area of flow, and to determine ground-water residence time in stream subsystems. In a geometrically simple aquifer system with accretion, the source area of flow to streams resembles an elongated ellipse that tapers in the downgradient direction. Increased recharge causes an expansion of the stream subsystem. The source area of flow to the stream expands predominantly toward the stream headwaters. Baseflow gain is also increased along the reach of the stream. A thin aquifer restricts ground-water flow and causes the source area of flow to expand near stream headwaters and also shifts the start-of-flow to the drainage basin divide. Increased aquifer anisotropy causes a lateral expansion of the source area of flow to streams. Ground-water seepage to the stream channel originates both from near- and far-recharge locations. The range in the lengths of flow paths that terminate at a point on a stream increase in the downstream direction. Consequently, the age distribution of ground water that seeps into the stream is skewed progressively older with distance downstream. Base flow ia an integration of ground water with varying age and potentially different water quality, depending on the source within the drainage basin

  11. TracerLPM (Version 1): An Excel® workbook for interpreting groundwater age distributions from environmental tracer data

    USGS Publications Warehouse

    Jurgens, Bryant C.; Böhlke, J.K.; Eberts, Sandra M.

    2012-01-01

    TracerLPM is an interactive Excel® (2007 or later) workbook program for evaluating groundwater age distributions from environmental tracer data by using lumped parameter models (LPMs). Lumped parameter models are mathematical models of transport based on simplified aquifer geometry and flow configurations that account for effects of hydrodynamic dispersion or mixing within the aquifer, well bore, or discharge area. Five primary LPMs are included in the workbook: piston-flow model (PFM), exponential mixing model (EMM), exponential piston-flow model (EPM), partial exponential model (PEM), and dispersion model (DM). Binary mixing models (BMM) can be created by combining primary LPMs in various combinations. Travel time through the unsaturated zone can be included as an additional parameter. TracerLPM also allows users to enter age distributions determined from other methods, such as particle tracking results from numerical groundwater-flow models or from other LPMs not included in this program. Tracers of both young groundwater (anthropogenic atmospheric gases and isotopic substances indicating post-1940s recharge) and much older groundwater (carbon-14 and helium-4) can be interpreted simultaneously so that estimates of the groundwater age distribution for samples with a wide range of ages can be constrained. TracerLPM is organized to permit a comprehensive interpretive approach consisting of hydrogeologic conceptualization, visual examination of data and models, and best-fit parameter estimation. Groundwater age distributions can be evaluated by comparing measured and modeled tracer concentrations in two ways: (1) multiple tracers analyzed simultaneously can be evaluated against each other for concordance with modeled concentrations (tracer-tracer application) or (2) tracer time-series data can be evaluated for concordance with modeled trends (tracer-time application). Groundwater-age estimates can also be obtained for samples with a single tracer measurement at one

  12. Age distribution of permfrost soil & surface water particulate organic carbon in the Lena Delta, Siberia

    NASA Astrophysics Data System (ADS)

    Winterfeld, M.; Flerus, R.; Koch, B.; Mollenhauer, G.

    2012-04-01

    Since several millennia huge amounts of organic carbon (OC) are stored frozen in circumarctic permafrost soils making up almost twice the amount of carbon currently present in the atmosphere. During the course of a proposed rapid climate change in the Arctic large quantities of this old OC are expected to be remobilized in dissolved (DOC) and particulate phases (POC) and exported to the Arctic shelf seas. Previous studies have shown that at present, DOC in Arctic river runoff is predominantly composed of relatively fresh organic material likely derived from the uppermost soil horizons. POC age data are scarce and where present show that it is substantially older than DOC. With our study we want to add information on the riverine POC exported by the Lena River to the Laptev Sea. Permafrost soil samples and surface water particulate matter (SPM) were collected in July/August 2009/2010 throughout the delta. Additional SPM samples were taken May/June 2011 during the spring flood and shortly after off the Island of Samoylov within the delta. Particulate organic carbon (POC) contents for 2009 vary between 280µg/L and 2155µg/L with an average of 918µg/L which is within the range of previously reported values. The Δ14C concentrations for POC of the same year show a broad range from -262‰ to -55‰ (average -158‰), which translates into ages of 2380±30yrs BP and 395±35yrs BP respectively (average ca. 1300yrs BP). The POC Δ14C concentrations reflect the age distribution found in the upper 1.4m of a permafrost peat cliff on Samoylov Island (-274‰ or 2510±30yrs BP). Karlsson et al (2011) found that POC samples in the SE Laptev Sea just off the Lena Delta contain young and bioavailable material interpreted to be derived from surface soils, which is in agreement with our late summer data. With the surface water POC contents in the Lena Delta of three consecutive years including one spring flood event presented here we improve our understanding of the interannual

  13. Iron concentrations and distributions in the parkinsonian substantia nigra of aged and young primate models

    NASA Astrophysics Data System (ADS)

    Ren, M. Q.; Xie, J. P.; Wang, X. S.; Ong, W. Y.; Leong, S. K.; Watt, F.

    2001-07-01

    Parkinson's disease (PD) is a progressive neuronal degenerative brain disease of the elderly, and is caused by the selective degeneration of neurons in the substantia nigra (SN) region of the brain, resulting in a reduced production of the neurotransmitter dopamine. Iron has been linked to dopaminergic cell death in Parkinson's disease because of its potential to promote free radicals, leading to oxidative stress. The present study is aimed at using the techniques of nuclear microscopy to elucidate the iron concentrations and distributions in the SN of both young and old monkeys following unilateral 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioning. A group of three old monkeys (older than 7 years) and a group of three young monkeys (younger than 7 years) were unilaterally MPTP-lesioned (right side) to induce parkinsonism and sacrificed after 35 days. The left side SN was used as a control. This time interval was chosen to correspond to an average 50% loss of dopamine producing cells in the lesioned right side SN. We have observed a significant difference in iron concentrations between the SNs of the young and old monkeys (increasing from an average of 233 to 1092 parts per million dry weight). When comparing the lesioned and non-lesioned SNs of the same animal, we found no significant difference in iron levels for each young monkey. However we have found a slight increase in iron (approximately 10%) between the lesioned SN and control SN for old monkeys. We have also observed that in the SN of younger primates, there is a weak anti-correlation in the SN iron levels with the neuron distribution. In the older monkeys, however, we have observed a proliferation of iron-rich granules, which appear to be more strongly anti-correlated with the distribution of neurons. The iron-cell anti-correlation occurs both in the control as well as the lesioned SN. Our results suggest that iron, particularly in the form of iron-rich deposits, accumulates in specific sites

  14. Increased Microbial Translocation in ≤180 Days Old Perinatally Human Immunodeficiency Virus Positive Infants as Compared with Human Immunodeficiency Virus -Exposed/Uninfected Infants of Similar Age

    PubMed Central

    PAPASAVVAS, EMMANOUIL; AZZONI, LIVIO; FOULKES, ANDREA; VIOLARI, AVY; COTTON, MARK F.; PISTILLI, MAXWELL; REYNOLDS, GRIFFIN; YIN, XIANGFAN; GLENCROSS, DEBORAH K.; STEVENS, WENDY S.; MCINTYRE, JAMES A.; MONTANER, LUIS J.

    2011-01-01

    Background We investigated the effect of early versus deferred antiretroviral treatment (ART) on plasma concentration of lipopolysaccharide (LPS) and host LPS-binding molecules in HIV-infected infants up to 1 year of age. Methods We evaluated 54 perinatally HIV-infected and 22 HIV-exposed/uninfected infants (controls) at the first and second semester of life. All HIV-infected infants had a baseline CD4≥25%, participated in the CIPRA-SA Children with HIV Early Antiretroviral Therapy (CHER) trial in South Africa and were randomized in: Group 1 (n=20), ART deferred until CD4<25% or severe HIV disease, and Group 2 (n=34), ART initiation within 6-12 weeks of age. LPS, endotoxin-core antibodies (EndoCAb), soluble (s)CD14, and LPS-binding protein (LBP) were measured in cryopreserved plasma. T cell activation was measured in fresh whole blood. Results At the first semester, LPS concentration was higher in HIV-infected infants than in controls; sCD14, LBP and T cell activation were higher in Group 1 than in Group 2 and controls. While LPS was not correlated with study variables, viral load was positively associated with sCD14, LBP or EndoCAb. At the second semester, LPS was not detectable and elevated host LPS-control molecules values were sustained, in all groups and in conjunction with ART in all HIV-infected infants. Conclusions While plasma concentration of LPS is higher in perinatally HIV-infected infants 0-6 months of age than in controls independent of ART initiation strategy, LPS-control molecules concentration is higher in infants with deferred ART, suggesting the presence of increased microbial translocation in HIV-infected infants with sustained early viral replication. PMID:21552185

  15. Crater size-frequency distribution measurements and age of the Compton-Belkovich Volcanic Complex

    NASA Astrophysics Data System (ADS)

    Shirley, K. A.; Zanetti, M.; Jolliff, B.; van der Bogert, C. H.; Hiesinger, H.

    2016-07-01

    The Compton-Belkovich Volcanic Complex (CBVC) is a 25 × 35 km feature on the lunar farside marked by elevated topography, high albedo, high thorium concentration, and high silica content. Morphologies indicate that the complex is volcanic in origin and compositions indicate that it represents rare silicic volcanism on the Moon. Constraining the timing of silicic volcanism at the complex is necessary to better understand the development of evolved magmas and when they were active on the lunar surface. We employ image analysis and crater size-frequency distribution (CSFD) measurements on several locations within the complex and at surrounding impact craters, Hayn (87 km diameter), and Compton (160 km diameter), to determine relative and absolute model ages of regional events. Using CSFD measurements, we establish a chronology dating regional resurfacing events and the earliest possible onset of CBVC volcanism at ∼3.8 Ga, the formation of Compton Crater at 3.6 Ga, likely resurfacing by volcanism at the CBVC at ∼3.5 Ga, and the formation of Hayn Crater at ∼1 Ga. For the CBVC, we find the most consistent results are obtained using craters larger than 300 m in diameter; the small crater population is affected by their approach to an equilibrium condition and by the physical properties of regolith at the CBVC.

  16. Age-related environmental gradients influence invertebrate distribution in the Prince Charles Mountains, East Antarctica.

    PubMed

    Czechowski, Paul; White, Duanne; Clarke, Laurence; McKay, Alan; Cooper, Alan; Stevens, Mark I

    2016-12-01

    The potential impact of environmental change on terrestrial Antarctic ecosystems can be explored by inspecting biodiversity patterns across large-scale gradients. Unfortunately, morphology-based surveys of Antarctic invertebrates are time-consuming and limited by the cryptic nature of many taxa. We used biodiversity information derived from high-throughput sequencing (HTS) to elucidate the relationship between soil properties and invertebrate biodiversity in the Prince Charles Mountains, East Antarctica. Across 136 analysed soil samples collected from Mount Menzies, Mawson Escarpment and Lake Terrasovoje, we found invertebrate distribution in the Prince Charles Mountains significantly influenced by soil salinity and/or sulfur content. Phyla Tardigrada and Arachnida occurred predominantly in low-salinity substrates with abundant nutrients, whereas Bdelloidea (Rotifera) and Chromadorea (Nematoda) were more common in highly saline substrates. A significant correlation between invertebrate occurrence, soil salinity and time since deglaciation indicates that terrain age indirectly influences Antarctic terrestrial biodiversity, with more recently deglaciated areas supporting greater diversity. Our study demonstrates the value of HTS metabarcoding to investigate environmental constraints on inconspicuous soil biodiversity across large spatial scales.

  17. Predicting water age distribution in the Pearl River Estuary using a three-dimensional model

    NASA Astrophysics Data System (ADS)

    Ren, Yuheng; Lin, Binliang; Sun, Jian; Pan, Shunqi

    2014-11-01

    The age of water (AW) concept is applied to investigate the water exchange process in a large and density stratified estuary, namely the Pearl River Estuary. A three-dimensional AW model has been built based on an existing hydrodynamic and solute transport model. The model is used to determine the AW distributions inside the Pearl River Estuary under various hydrodynamic conditions. The predicted mean AW values during the dry and wet seasons are approximately 25 and 10 days, respectively. In general, lower AW values are observed in the upper layers near the water surface, while higher values are observed in the lower layers near the bed. The difference becomes more pronounced during the wet season when the river discharge is very large. The tidal influence is relatively small. The variation of tidal forcing impacts mainly on the AW fluctuation range, but it has limited impact on the tidally averaged AW value. Moreover, the AW vertical difference is enhanced during neap tides. A comparison between the predictions using barotropic and baroclinic models indicates that the density-induced circulation has a significant impact on the water exchange rate.

  18. Age-related environmental gradients influence invertebrate distribution in the Prince Charles Mountains, East Antarctica

    PubMed Central

    White, Duanne; Clarke, Laurence; McKay, Alan; Cooper, Alan; Stevens, Mark I.

    2016-01-01

    The potential impact of environmental change on terrestrial Antarctic ecosystems can be explored by inspecting biodiversity patterns across large-scale gradients. Unfortunately, morphology-based surveys of Antarctic invertebrates are time-consuming and limited by the cryptic nature of many taxa. We used biodiversity information derived from high-throughput sequencing (HTS) to elucidate the relationship between soil properties and invertebrate biodiversity in the Prince Charles Mountains, East Antarctica. Across 136 analysed soil samples collected from Mount Menzies, Mawson Escarpment and Lake Terrasovoje, we found invertebrate distribution in the Prince Charles Mountains significantly influenced by soil salinity and/or sulfur content. Phyla Tardigrada and Arachnida occurred predominantly in low-salinity substrates with abundant nutrients, whereas Bdelloidea (Rotifera) and Chromadorea (Nematoda) were more common in highly saline substrates. A significant correlation between invertebrate occurrence, soil salinity and time since deglaciation indicates that terrain age indirectly influences Antarctic terrestrial biodiversity, with more recently deglaciated areas supporting greater diversity. Our study demonstrates the value of HTS metabarcoding to investigate environmental constraints on inconspicuous soil biodiversity across large spatial scales. PMID:28083092

  19. The application of age distribution theory in the analysis of cytofluorimetric DNA histogram data.

    PubMed

    Watson, J V

    1977-03-01

    Age distribution theory has been employed in a model to analyse a variety of histograms of the DNA content of single cells in samples from experimental tumours growing in tissue culture. The method has produced satisfactory correspondence with the experimental data in which there was a wide variation in the proportions of cells in the intermitotic phases, and generally good agreement between the 3H-thymidine labelling index and the computed proportion in S phase. The model has the capacity to analyse data from populations which contain a proportion of non-cycling cells. However, it is concluded that reliable results for the growth fraction and also for the relative durations of the intermitotic phase times cannot be obtained for the data reported here from the DNA histograms alone. To obtain reliable estimates of the growth fraction the relative durations of the phase time must be known, and conversely, reliable estimates of the relative phase durations can only be obtained if the growth fraction is known.

  20. [Bacterial isolates from respiratory samples of pediatric patients with cystic fibrosis and their distribution by ages].

    PubMed

    Busquets, Natalia P; Baroni, María R; Ochoteco, María C; Zurbriggen, María L; Virgolini, Stella; Meneghetti, Fernando G

    2013-01-01

    The bacterial isolates from respiratory samples of 50 pediatric patients with cystic fibrosis, their distribution by ages and antimicrobial resistance pattern as well as the intermittence of isolations and coinfections, were investigated. Staphylococcus aureus was isolated in 72 % of patients, followed by Pseudomonas aeruginosa (58 %), Haemophilus. influenzae (56 %), and the Burkholderia cepacia complex (12 %). The frequency of resistance of P. aeruginosa isolates to β-lactam antibiotics was low (13.8 %). Fifty percent of S. aureus isolates was methicillin-resistant, and 57.1 % of H. influenza was ampicillin resistant due to β-lactamase production. In children under 4 years-old, S. aureus was predominant, followed by P. aeruginosa and H. influenzae. This order of predominance was observed in all the groups studied, except in that of children between 10 and 14 years-old. Stenotrophomonas maltophilia and Achromobacter xylosoxidans isolates were intermittent and accompanied by other microorganisms. Finally, we observed a great variety of bacterial species, which imposes stringent performance requirements for microbiological studies in all respiratory samples of these patients.

  1. Understanding reliance on automation: effects of error type, error distribution, age and experience

    PubMed Central

    Sanchez, Julian; Rogers, Wendy A.; Fisk, Arthur D.; Rovira, Ericka

    2015-01-01

    An obstacle detection task supported by “imperfect” automation was used with the goal of understanding the effects of automation error types and age on automation reliance. Sixty younger and sixty older adults interacted with a multi-task simulation of an agricultural vehicle (i.e. a virtual harvesting combine). The simulator included an obstacle detection task and a fully manual tracking task. A micro-level analysis provided insight into the way reliance patterns change over time. The results indicated that there are distinct patterns of reliance that develop as a function of error type. A prevalence of automation false alarms led participants to under-rely on the automation during alarm states while over relying on it during non-alarms states. Conversely, a prevalence of automation misses led participants to over-rely on automated alarms and under-rely on the automation during non-alarm states. Older adults adjusted their behavior according to the characteristics of the automation similarly to younger adults, although it took them longer to do so. The results of this study suggest the relationship between automation reliability and reliance depends on the prevalence of specific errors and on the state of the system. Understanding the effects of automation detection criterion settings on human-automation interaction can help designers of automated systems make predictions about human behavior and system performance as a function of the characteristics of the automation. PMID:25642142

  2. Numerical simulation of transient groundwater age distributions assisting land and water management in the Middle Wairarapa Valley, New Zealand

    NASA Astrophysics Data System (ADS)

    Toews, Michael W.; Daughney, Christopher J.; Cornaton, Fabien J.; Morgenstern, Uwe; Evison, Ryan D.; Jackson, Bethanna M.; Petrus, Karine; Mzila, Doug

    2016-12-01

    This study used numerical models to simulate transient groundwater age distributions using a time-marching Laplace transform Galerkin (TMLTG) technique. First, the TMLTG technique was applied to simple box models configured to match idealized lumped parameter models (LPMs). Even for simple box models, time-varying recharge can generate groundwater age distributions with highly irregular shapes that vary over time in response to individual recharge events. Notably, the transient numerical simulations showed that the breakthrough and mean ages are younger than in the steady flow case, and that this difference is greater for sporadic recharge time series than for more regular recharge time series. Second, the TMLTG technique was applied to a transient numerical model of the 270 km2 Middle Wairarapa Valley, New Zealand. To our knowledge this study is the first application of the TMLTG technique to a real-world example, made possible by the data set of tritium measurements that exists for the Wairarapa Valley. Results from a transient mean age simulation shows variation from a few days to over a decade in either temporal or spatial dimensions. Temporal variations of mean age are dependent on seasonal climate and groundwater abstraction. Results also demonstrated important differences between the transient age distributions derived from the TMLTG technique compared to the much simpler steady-state LPMs that are frequently applied to interpret age tracer data. Finally, results had direct application to land and water management, for example for identification of land areas where age distributions vary seasonally, affecting the security of groundwater supplies used for drinking water.

  3. Age-dependence of the optomechanical responses of ex vivo human lenses from India and the USA, and the force required to produce these in a lens stretcher: the similarity to in vivo disaccommodation

    PubMed Central

    Augusteyn, Robert C; Mohamed, Ashik; Nankivil, Derek; Veerendranath, Pesala; Arrieta, Esdras; Taneja, Mukesh; Manns, Fabrice; Ho, Arthur; Parel, Jean-Marie

    2011-01-01

    The purpose of this study was to study the age-dependence of the optomechanical properties of human lenses during simulated disaccommodation in a mechanical lens stretcher, designed to determine accommodative forces as a function of stretch distance, to compare the results with in vivo disaccommodation and to examine whether differences exist between eyes harvested in the USA and India. Post-mortem human eyes obtained in the USA (n=46, age = 6 to 83 years) and India (n=91, age = 1 day to 85 years) were mounted in an optomechanical lens stretching system and dissected to expose the lens complete with its accommodating framework, including zonules, ciliary body, anterior vitreous and a segmented rim of sclera. Disaccommodation was simulated through radial stretching of the sectioned globe by 2 mm in increments of 0.25 mm. The load, inner ciliary ring diameter, lens equatorial diameter, central thickness and power were measured at each step. Changes in these parameters were examined as a function of age, as were the dimension/load and power/load responses. Unstretched lens diameter and thickness increased over the whole age range examined and were indistinguishable from those of in vivo lenses as well as those of in vitro lenses freed from zonular attachments. Stretching increased the diameter and decreased the thickness in all lenses examined but the amount of change decreased with age. Unstretched lens power decreased with age and the accommodative amplitude decreased to zero by age 45-50. The load required to produce maximum stretch was independent of age (median 80 mN) whereas the change in lens diameter and power per unit load decreased significantly with age. The age related changes in the properties of human lenses, as observed in the lens stretching device, are similar to those observed in vivo and are consistent with the classical Helmholtz theory of accommodation. The response of lens diameter and power to disaccommodative (stretching) forces decreases with

  4. Maternal leptin concentrations are similar in African Americans and Caucasians in normal pregnancy, preeclampsia and small-for-gestational-age infants.

    PubMed

    Jenkins, Laura D; Powers, Robert W; Adotey, Mary; Gallaher, Marcia J; Markovic, Nina; Ness, Roberta B; Roberts, James M

    2007-01-01

    Leptin concentrations were measured in African American women in order to assess leptin's role in the increased frequency and severity of preeclampsia. In addition, leptin concentrations were measured in women who delivered small-for-gestational-age (SGA) infants. A case-control study of African American and Caucasian women with normal pregnancies, preeclampsia, or SGA infants was done. Plasma leptin was quantitated by radio-immunoassay. The previously recognized pattern of increased leptin concentrations in preeclampsia was replicated. Leptin concentrations did not differ by race in any diagnostic category, and concentrations in women with SGA infants were not higher than those in healthy women. Differences in the frequency and severity of preeclampsia in African Americans cannot be explained by higher leptin concentrations.

  5. Ultraviolet to near-infrared spectral distributions of star-forming galaxies: Metallicity and age effects

    NASA Technical Reports Server (NTRS)

    Storchi-Bergmann, Thaisa; Calzetti, Daniela; Kinney, Anne L.

    1994-01-01

    Spectral distributions from the UV to the near-IR of a sample of 44 star-forming galaxies are used to calculate the metallicity (O/H), star-formation rate (SFR) and age of the starbursts. The oxygen abundance covers the range 8.3 less than O/H less than 9.4 and nitrogen (N) is found to be mostly a product of secondary nucleosynthesis for O/H greater than 8.4. Due to its secondary origin, N/O ratios up to approximately equals 4 times the solar value can be obtained for metal-rich starbursts. The SFR ranges 0.01 to 100 solar mass/year. The lower metallicity galaxies seem to be experiencing an instantaneous burst of star formation, with ages ranging from under 5 x 10(exp 6) to 10(exp 7) yr. The highest metallicity galaxies are most probably experiencing a continuous burst. Correlations between the calculated quantities and several spectral features are investigated. We found a highly significant correlation between the equivalent width W(C IV lambda 1550)-a stellar (absorption) feature- and the oxygen abundance of the emitting gas (O/H). Thus we show for the first time that the stellar metallicity is well correlated with the gas metallicity in star-bursting galaxies. The equivalent width W(Si IV lambda 1400) and the emission line ratio (N II) lambda lambda 6548.84/H(sub alpha) also correlate well with O/H, and all three features can be used as metallicity indicators for star-forming galaxies. The continuum color between lambda 1400 and lambda 3500 (C(14 - 35)) is shown to correlate with O/H, although it is better correlated with E(B - V). It was not possible to disentangle the metallicity from the reddening effect in C(14- 35). We estimate that the reddening affecting the UV continuum is about half the one derived from the Balmer decrement of the emitting gas. The SFR correlates well with the galaxy luminosity and there is no dependence of the continuum color on the SFR. The higher metallicities are only found in the more luminous galaxies, while low metallicities are

  6. Age-related prevalence, intensity and frequency distribution of gastrointestinal helminth infection in urban slum children from Kuala Lumpur, Malaysia.

    PubMed

    Bundy, D A; Kan, S P; Rose, R

    1988-01-01

    The gastrointestinal helminth infection status of 1574 children living in a slum area of Kuala Lumpur, Malaysia was assessed by quantitative coprology. Almost two-thirds were infected with Trichuris trichiura, 49.6% with Ascaris lumbricoides, and 5.3% with hookworm. Infection prevalence rose rapidly to a stable asymptote at 7 years of age, and the age-intensity profile was convex with maximal values in the 5-10 year age classes. This pattern was the same for males and females, but differed markedly between different ethnic groups. The frequency distributions of A. lumbricoides and T. trichiura were highly overdispersed (k values were 0.21 and 0.27, respectively), and age-dependent over the 0-8 year age classes. This suggests that the force of infection with these nematodes is lower in infants than in older children.

  7. Distribution of terrestrial age and petrologic type of meteorites from western Libya

    NASA Technical Reports Server (NTRS)

    Jull, A. J. T.; Donahue, D. J.; Wlotzka, F.; Palme, H.

    1990-01-01

    A group of 54 meteorites have been recovered from Daraj, Western Libya. After assessment of pairing of samples, using petrologic criteria, C-14 terrestrial ages were obtained on 13 samples selected from 9 different fall events. Eleven of the ages range from 3500 to 7600 years, with only two samples having ages in excess of 10,000 years. The cutoff in ages may be related to the timing of climatic changes in the Hammadah al Hamra.

  8. Prevalence and Distribution of Abdominal Aortic Calcium by Sex and Age-Group in a Community-based Cohort (From The Framingham Heart Study)

    PubMed Central

    Chuang, Michael L.; Massaro, Joseph M.; Levitzky, Yamini S.; Fox, Caroline S.; Manders, Emily S.; Hoffmann, Udo; O'Donnell, Christopher J.

    2012-01-01

    Abdominal aortic calcium (AAC) is associated with incident cardiovascular disease but the age and sex-related distribution of AAC in a community-dwelling population free of standard cardiovascular disease risk factors has not been described. A total of 3285 participants (aged 50.2±9.9 years) in the Framingham Heart Study Offspring and Third Generation cohorts underwent abdominal multidetector computed tomography (MDCT) scanning during 1998-2005. The presence and amount of AAC was quantified (Agatston score) by an experienced reader using standardized criteria. A healthy referent subsample (N=1656, 803 men) free of hypertension, hyperlipidemia, diabetes, obesity and smoking was identified, and participants were stratified by sex and age group (<45, 45-54, 55-64, 65-74, ≥75 years). The prevalence and burden of AAC increased monotonically and supralinearly with age in both sexes but was greater in men than women in each age group. Below age 45 <16% of referent-subsample participants had any quantifiable AAC, while above age 65 nearly 90% of referent participants had >0 AAC. Across the entire study sample, AAC prevalence and burden similarly increased with greater age. Defining the 90th percentile of referent group AAC as “high,” the prevalence of high AAC was 19% for each sex in the overall study sample. AAC also increased across categories of 10-year coronary heart disease risk, as calculated using the Framingham Risk Score, in the entire study sample. We found AAC to be widely prevalent, with the burden of AAC associated with 10-year coronary risk, in a white, free-living adult cohort. PMID:22727181

  9. A Lateglacial to late Holocene glacial chronology for the Cairngorm Mountains (Scotland): effects of boulder inheritance and snow shielding on age distributions.

    NASA Astrophysics Data System (ADS)

    Kirkbride, Martin; Everest, Jez; Benn, Doug

    2014-05-01

    It is thought that British glaciers disappeared after the Younger Dryas Stadial (YDS, 12.9 - 11.7 k yr). We present cosmogenic 10Be ages of cirque moraines in the Cairngorm Mountains which include two Lateglacial advances, a speculative early Holocene advance, and a late Holocene moraine probably deposited by a Little Ice Age glacier ( 17th - 18th century AD). One cirque (CLE) contains evidence of a YDS advance peaking at c. 12.3 k yr, and a probable Little Ice Age (LIA) advance dated to <0.9 k yr. Another cirque (CLW) has an outer moraine dated to between 15.3 and 12.0 k yr. An inner moraine, conventionally regarded as YDS in age, yields 10Be ages of 11.5 to 8.3 k yr (Lal/Stone time-dependent production model). The putative YDS moraines are well dated in cirque CLE, but appear too "young" in CLW. We consider how snow-shielding and boulder recycling may have affected age distributions. If these ages are minima from a YDS moraine, snow-shielding and delayed deposition from debris-covered ice may explain low 10Be concentrations, but this does not explain why similar adjustments are not needed in the neighbouring cirque. Alternatively, ages may be maxima from an early Holocene moraine which incorporated existing boulders. The LIA moraine in CLE contains a high proportion of inherited boulders, but the YDS moraine here contains few. Therefore the proportion of inherited boulders is estimated to be a function of the ratio of debris production during the glacial period and debris production during the preceding paraglacial period. The ratio describes the likelihood of sampling an inherited boulder if the geomorphological history is understood. By this reasoning, an alternative interpretation of the "YDS" moraine in CLW is that an early Holocene glacier (speculatively, the 8.2 k event?) incorporated post-YDS paraglacial rock fall debris.

  10. Changes in Angiotensin Receptor Distribution and in Aortic Morphology Are Associated with Blood Pressure Control in Aged Metabolic Syndrome Rats

    PubMed Central

    Guarner-Lans, Verónica; Soria-Castro, Elizabeth; Torrico-Lavayen, Rocío; Patrón-Soberano, Araceli; Carvajal-Aguilera, Karla G.; Castrejón-Tellez, Vicente; Rubio-Ruiz, María Esther

    2016-01-01

    The role of the renin-angiotensin system (RAS) in blood pressure regulation in MS during aging is unknown. It participates in metabolic syndrome (MS) and aging regulating vascular tone and remodeling. RAS might participate in a compensatory mechanism decreasing blood pressure and allowing MS rats to reach 18 months of age and it might form part of therapeutical procedures to ameliorate MS. We studied histological changes and distribution of RAS receptors in aortas of MS aged rats. Electron microscopy images showed premature aging in MS since the increased fibrosis, enlarged endothelium, and invasion of this layer by muscle cells that was present in control 18-month-old aortas were also found in 6-month-old aortas from MS rats. AT1, AT2, and Mas receptors mediate the effects of Ang II and Ang 1-7, respectively. Fluorescence from AT2 decreased with age in control and MS aortas, while fluorescence of AT1 increased in aortas from MS rats at 6 months and diminished during aging. Mas expression increased in MS rats and remained unchanged in control rats. In conclusion, there is premature aging in the aortas from MS rats and the elevated expression of Mas receptor might contribute to decrease blood pressure during aging in MS. PMID:27293881

  11. Similar Occurrence of Febrile Episodes Reported in Non-Atopic Children at Three to Five Years of Age after Prebiotics Supplemented Infant Formula

    PubMed Central

    van Stuijvenberg, Margriet; Stam, José; Grüber, Christoph; Mosca, Fabio; Arslanoglu, Sertac; Chirico, Gaetano; Braegger, Christian P.; Riedler, Josef; Boehm, Günther; Sauer, Pieter J. J.

    2015-01-01

    This is a follow up study of a multicenter randomised placebo-controlled trial in seven centres in five West European countries. The RCT assessed the effect of infant formula supplemented with a mixture of prebiotics (with neutral short-chain and long-chain oligosaccharides and pectin-derived acidic oligosaccharides) during infancy in term-born children (n=1130). In the follow-up study 672 children (60% of the study population) participated: 232 (56%) from the prebiotics group (PG), 243 (58%) from the control group (CG), and 197 (66%) from the non-randomised breast-fed group (BG). The primary outcome was the occurrence of febrile episodes at three to five years of age prospectively documented by the parents: in the PG 1.17 (interquartile range 0.50-2.08) episodes per year versus 1.20 (0.52-2.57) in the CG; and 1.48 (0.65-2.60) in the BG. This specific prebiotics mixture given during infancy in healthy non-atopic subjects does not decrease febrile episodes and therefore seems not to prevent infection between their third and fifth birthday. PMID:26076141

  12. Similar Occurrence of Febrile Episodes Reported in Non-Atopic Children at Three to Five Years of Age after Prebiotics Supplemented Infant Formula.

    PubMed

    van Stuijvenberg, Margriet; Stam, José; Grüber, Christoph; Mosca, Fabio; Arslanoglu, Sertac; Chirico, Gaetano; Braegger, Christian P; Riedler, Josef; Boehm, Günther; Sauer, Pieter J J

    2015-01-01

    This is a follow up study of a multicenter randomised placebo-controlled trial in seven centres in five West European countries. The RCT assessed the effect of infant formula supplemented with a mixture of prebiotics (with neutral short-chain and long-chain oligosaccharides and pectin-derived acidic oligosaccharides) during infancy in term-born children (n=1130). In the follow-up study 672 children (60% of the study population) participated: 232 (56%) from the prebiotics group (PG), 243 (58%) from the control group (CG), and 197 (66%) from the non-randomised breast-fed group (BG). The primary outcome was the occurrence of febrile episodes at three to five years of age prospectively documented by the parents: in the PG 1.17 (interquartile range 0.50-2.08) episodes per year versus 1.20 (0.52-2.57) in the CG; and 1.48 (0.65-2.60) in the BG. This specific prebiotics mixture given during infancy in healthy non-atopic subjects does not decrease febrile episodes and therefore seems not to prevent infection between their third and fifth birthday.

  13. Distribution of terrestrial age and petrologic type of meteorites from western Libya

    SciTech Connect

    Jull, A.J.T.; Donahue, D.J. ); Wlotzka, F.; Palme, H. )

    1990-10-01

    A group of 54 meteorites have been recovered from Daraj, Western Libya. After assessment of pairing of samples, using petrologic criteria, {sup 14}C terrestrial ages were obtained on 13 samples selected from 9 different fall events. Eleven of the ages range from 3,500 to 7,600 years, with only two samples having ages in excess of 10,000 years. The cut-off in ages may be related to the timing of climatic changes in the Hammadah al Hamra.

  14. Some bounds in classes of {open_quotes}aging{close_quotes} distributions

    SciTech Connect

    Kotlyar, V.Yu.

    1995-03-01

    Reliability of technical systems is closely linked with {open_quotes}aging{close_quotes} properties of the components. So-called monotone systems whose components have certain aging characteristics are of considerable importance in this field of research. Efficient bounds of reliability, mean time to failure, and other parameters can be obtained for such systems. The bounds in literature were obtained under the least restrictive assumptions on aging. In this paper, we generalize some results of literature to the case of even more general aging principles, specifically, when the system components are HNBUE, HNWUE, NBAFR, NWAFR in terms of their reliability properties. We start with a definition of these properties.

  15. The age, growth, and bathymetric distribution of Reighard's chub, Leucichthys reighardi koelz, in Lake Michigan

    USGS Publications Warehouse

    1943-01-01

    The females were always strongly dominant in the samples except during May and June 1931 and May 1932 when the sexes occurred in about equal numbers. The relative abundance of the sexes did not change materially in age-groups II to V. There were no males assigned to age-groups VI and VII.

  16. Similarity and difference of global reanalysis datasets (WFD and APHRODITE) in driving lumped and distributed hydrological models in a humid region of China

    NASA Astrophysics Data System (ADS)

    Xu, Hongliang; Xu, Chong-Yu; Chen, Sidian; Chen, Hua

    2016-11-01

    Different conclusions have been drawn in literature as using reanalysis rainfall products to drive hydrological models for the simulation of streamflow, which warrant a need of further investigation before a generalised conclusion can be drawn. This paper assesses the utility of two widely used reanalysis rainfall datasets (WFD (developed by the WATCH project) and APHRODITE (Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation of the water resources)) against the gauged rainfall in terms of flood simulation in lumped (Xinanjiang Model) and distributed (SWAT Model) hydrological models in a tributary basin of Yangtze River with 94,660 km2 drainage area in humid region of southern China. Differences in terms of rainfall accumulation, number of rainy days, spatial patterns of the rainfall amount and frequency distribution of the rain rates are evaluated. The APHRODITE product shows high consistency with the gauged rainfall while WFD data gives large errors in various statistical indices in the study region. Simulated discharges from the gauged and reanalysis rainfall data, respectively, are analysed and compared with the observed discharge in basin outlet over the period 1991-2005. The APHRODITE data show relatively high ability in modelling hydrological responses while the WFD data based models give large error in simulating the discharge. For the assessment of the high flows, both datasets exhibit some skills in flood prediction, however, APHRODITE data perform better than the WFD data when forcing into the lumped Xinanjiang Model than into the distributed SWAT Model in terms of flood duration, Probability of Detection, False Alarm Rate, regressions of annual peaks and partial duration series.

  17. Characterization and distribution of a maize cDNA encoding a peptide similar to the catalytic region of second messenger dependent protein kinases

    NASA Technical Reports Server (NTRS)

    Biermann, B.; Johnson, E. M.; Feldman, L. J.

    1990-01-01

    Maize (Zea mays) roots respond to a variety of environmental stimuli which are perceived by a specialized group of cells, the root cap. We are studying the transduction of extracellular signals by roots, particularly the role of protein kinases. Protein phosphorylation by kinases is an important step in many eukaryotic signal transduction pathways. As a first phase of this research we have isolated a cDNA encoding a maize protein similar to fungal and animal protein kinases known to be involved in the transduction of extracellular signals. The deduced sequence of this cDNA encodes a polypeptide containing amino acids corresponding to 33 out of 34 invariant or nearly invariant sequence features characteristic of protein kinase catalytic domains. The maize cDNA gene product is more closely related to the branch of serine/threonine protein kinase catalytic domains composed of the cyclic-nucleotide- and calcium-phospholipid-dependent subfamilies than to other protein kinases. Sequence identity is 35% or more between the deduced maize polypeptide and all members of this branch. The high structural similarity strongly suggests that catalytic activity of the encoded maize protein kinase may be regulated by second messengers, like that of all members of this branch whose regulation has been characterized. Northern hybridization with the maize cDNA clone shows a single 2400 base transcript at roughly similar levels in maize coleoptiles, root meristems, and the zone of root elongation, but the transcript is less abundant in mature leaves. In situ hybridization confirms the presence of the transcript in all regions of primary maize root tissue.

  18. Deep-sea scleractinian coral age and depth distributions in the northwest Atlantic for the last 225,000 years

    USGS Publications Warehouse

    Robinson, L.F.; Adkins, J.F.; Scheirer, D.S.; Fernandez, D.P.; Gagnon, A.; Waller, R.G.

    2007-01-01

    Deep-sea corals have grown for over 200,000 yrs on the New England Seamounts in the northwest Atlantic, and this paper describes their distribution both with respect to depth and time. Many thousands of fossil scleractinian corals were collected on a series of cruises from 2003-2005; by contrast, live ones were scarce. On these seamounts, the depth distribution of fossil Desmophyllum dianthus (Esper, 1794) is markedly different to that of the colonial scleractinian corals, extending 750 m deeper in the water column to a distinct cut-off at 2500 m. This cut-off is likely to be controlled by the maximum depth of a notch-shaped feature in the seamount morphology. The ages of D. dianthus corals as determined by U-series measurements range from modern to older than 200,000 yrs. The age distribution is not constant over time, and most corals have ages from the last glacial period. Within the glacial period, increases in coral population density at Muir and Manning Seamounts coincided with times at which large-scale ocean circulation changes have been documented in the deep North Atlantic. Ocean circulation changes have an effect on coral distributions, but the cause of the link is not known. ?? 2007 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.

  19. Lipid-laden cells differentially distributed in the aging brain are functionally active and correspond to distinct phenotypes.

    PubMed

    Shimabukuro, Marilia Kimie; Langhi, Larissa Gutman Paranhos; Cordeiro, Ingrid; Brito, José M; Batista, Claudia Maria de Castro; Mattson, Mark P; Mello Coelho, Valeria de

    2016-03-31

    We characterized cerebral Oil Red O-positive lipid-laden cells (LLC) of aging mice evaluating their distribution, morphology, density, functional activities and inflammatory phenotype. We identified LLC in meningeal, cortical and neurogenic brain regions. The density of cerebral LLC increased with age. LLC presenting small lipid droplets were visualized adjacent to blood vessels or deeper in the brain cortical and striatal parenchyma of aging mice. LLC with larger droplets were asymmetrically distributed in the cerebral ventricle walls, mainly located in the lateral wall. We also found that LLC in the subventricular region co-expressed beclin-1 or LC3, markers for autophagosome or autophagolysosome formation, and perilipin (PLIN), a lipid droplet-associated protein, suggesting lipophagic activity. Some cerebral LLC exhibited β galactosidase activity indicating a senescence phenotype. Moreover, we detected production of the pro-inflammatory cytokine TNF-α in cortical PLIN(+) LLC. Some cortical NeuN(+) neurons, GFAP(+) glia limitans astrocytes, Iba-1(+) microglia and S100β(+) ependymal cells expressed PLIN in the aging brain. Our findings suggest that cerebral LLC exhibit distinct cellular phenotypes and may participate in the age-associated neuroinflammatory processes.

  20. [Dynamics of elements distribution in blood, depending on age, by example of Moscow Region residents].

    PubMed

    Yuvs, G G; Ignatova, T N; Anuchin, A M; Lebedeva, V L; Shilov, V V; Khapalyuk, A V

    2015-01-01

    Elemental status of a person determines the qualitative and quantitative content of chemical elements in the human body. This marker allows us to estimate the level of imbalance of chemical elements and therefore health risks. The method for simultaneous quantitative and qualitative analysis of 67 elements in biomaterials has been proposed. The detailed elemental analysis of whole blood samples of 1711 healthy people (age range 0-100 years) of Moscow Region has been performed. A number of patterns of age-related changes of the element status conditionally healthy people has been estimated. Na content in the samples increased with the age of the person. Presumably, this result reflects the studied populations nutrition disorders associated with immoderate consumption of table salt. The maximum content of Ca was observed in blood samples of people age range 0-20 years (66-69 mg/kg), the Ca content in the blood samples of people age range 26-85 years was significantly lower (59-62 mg/kg). The maximum decrease of Ca was detected in blood samples of people age range of 85-100 years (57-59 mg/kg). Thisreductionin the concentration of Ca, apparently due to age-related changes of Ca balance, correlates with decrease of bone mineral density and bone mass. Iron content decreased in the blood samples of people age range 10-100 years from 480 to 390 mg/kg. Selenium content in blood of people age range 0-25 years linearly increased, remained stable high in the blood of people age range 25-55 years (0,13-0,136 mg/kg) and then gradually decreased. A graph of As content dependence from a person's age is a mirror image of the graph of Se content dependence from a person's age, which is evidence of the antagonistic effects of these elements. Graphic changes in the content of rare earth elements Eu and Ho reflect the unidirectional trend of these elements accumulation. The maximum content of these elements was observed in blood samples of people age range of 25-65 years. Perhaps a

  1. [The specific distribution of erythrocytes and blood platelets according to the volume of cells in different-age children].

    PubMed

    Matiushichev, V B; Sharmatova, V G

    2005-01-01

    The reference volumes of erythrocytes and blood platelets were evaluated for different age groups of children. The mean volume of cells and the parameters of its distribution, i.e. SD, As and Ex, were found. The mean volume of erythrocytes and the value of positive Ex for the volume of blood platelets were shown to be reliably higher in adults. The investigated blood parameters in children were proven to depend in children on their age and sex. It was concluded that the mentioned peculiarities should be considered in the practice of clinical laboratory examinations.

  2. Refugia in glacial ages led to the current discontinuous distribution patterns of the dark red-backed vole Myodes rex on Hokkaido, Japan.

    PubMed

    Kawai, Kuniko; Hailer, Frank; de Guia, Anna Pauline; Ichikawa, Hideo; Saitoh, Takashi

    2013-08-01

    The terrestrial mammalian fauna of the North Japanese island, Hokkaido, is more similar to that of Southern Siberia than to the main island of Japan, Honshu. Three species of the genus Myodes (Muridae, Rodentia) are found on Hokkaido, but not on Honshu. While Myodes rufocanus and M. rutilus are widely distributed across Hokkaido as well as the Eurasian continent, M. rex, which is endemic to Hokkaido and its adjacent islands, shows a discontinuous distribution pattern. We analyzed the phylogeographic history of M. rex using the mitochondrial DNA control region in order to interpret their discontinuous distribution pattern. Phylogenetic relationships among 54 distinct haplotypes showed that M. rex can be divided into four clades that occur on the northern, central, and southern regions of the Hokkaido mainland and on Rishiri Island, respectively. The phylogroups in the northern and central regions were largely separated in space, although several areas of sympatry were found. The phylogroup in the southern region, which was clearly separated from other phylogroups, showed markedly low genetic variability. All analyzed individuals from the population on Rishiri belonged to a separate lineage. Across a range of divergence rate estimates, we dated the basal divergence of all phylogroups to the mid to late Pleistocene, with subsequent signals of population expansion within lineages. We conclude that current phylogeographic structure in M. rex likely reflects Pleistocene survival in several separate refugia in situ. Past glacial ages have thus played an important role in shaping the current distribution patterns of mammalian species on Hokkaido.

  3. A new study of shower age distribution in near vertical showers by EAS air shower array

    NASA Technical Reports Server (NTRS)

    Chaudhuri, N.; Basak, D. K.; Goswami, G. C.; Ghosh, B.

    1984-01-01

    The air shower array has been developed since it started operation in 1931. The array covering an area of 900 sq m now incorporates 21 particle density sampling detectors around two muon magnetic spectrographs. The air showers are detected in the size range 10 to the 4th power to 10 to the 6th power particles. A total of 11000 showers has so far been detected. Average values of shower age have been obtained in various shower size ranges to study the dependence of shower age on shower size. The core distance dependence of shower age parameter has also been analyzed for presentation.

  4. Prevalence and distribution of abdominal aortic calcium by gender and age group in a community-based cohort (from the Framingham Heart Study).

    PubMed

    Chuang, Michael L; Massaro, Joseph M; Levitzky, Yamini S; Fox, Caroline S; Manders, Emily S; Hoffmann, Udo; O'Donnell, Christopher J

    2012-09-15

    Abdominal aortic calcium (AAC) is associated with incident cardiovascular disease. However, the age- and gender-related distribution of AAC in a community-dwelling population free of standard cardiovascular disease risk factors has not been described. A total of 3,285 participants (aged 50.2 ± 9.9 years) in the Framingham Heart Study Offspring and Third Generation cohorts underwent abdominal multidetector computed tomography from 1998 to 2005. The presence and amount of AAC was quantified (Agatston score) by an experienced reader using standardized criteria. A healthy referent subsample (n = 1,656, 803 men) free of hypertension, hyperlipidemia, diabetes, obesity, and smoking was identified, and participants were stratified by gender and age (<45, 45 to 54, 55 to 64, 65 to 74, and ≥75 years). The prevalence and burden of AAC increased monotonically and supra-linearly with age in both genders but was greater in men than in women in each age group. For those <45 years old, <16% of the referent subsample participants had any quantifiable AAC. However, for those >65 years old, nearly 90% of the referent participants had >0 AAC. Across the entire study sample, AAC prevalence and burden similarly increased with greater age. Defining the 90th percentile of the referent group AAC as "high," the prevalence of high AAC was 19% for each gender in the overall study sample. The AAC also increased across categories of 10-year coronary heart disease risk, as calculated using the Framingham Risk Score, in the entire study sample. We found AAC to be widely prevalent, with the burden of AAC associated with 10-year coronary risk, in a white, free-living adult cohort.

  5. FUNDAMENTAL PARAMETERS AND SPECTRAL ENERGY DISTRIBUTIONS OF YOUNG AND FIELD AGE OBJECTS WITH MASSES SPANNING THE STELLAR TO PLANETARY REGIME

    SciTech Connect

    Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L.

    2015-09-10

    We combine optical, near-infrared, and mid-infrared spectra and photometry to construct expanded spectral energy distributions for 145 field age (>500 Myr) and 53 young (lower age estimate <500 Myr) ultracool dwarfs (M6-T9). This range of spectral types includes very low mass stars, brown dwarfs, and planetary mass objects, providing fundamental parameters across both the hydrogen and deuterium burning minimum masses for the largest sample assembled to date. A subsample of 29 objects have well constrained ages as probable members of a nearby young moving group. We use 182 parallaxes and 16 kinematic distances to determine precise bolometric luminosities (L{sub bol}) and radius estimates from evolutionary models give semi-empirical effective temperatures (T{sub eff}) for the full range of young and field age late-M, L, and T dwarfs. We construct age-sensitive relationships of luminosity, temperature, and absolute magnitude as functions of spectral type and absolute magnitude to disentangle the effects of degenerate physical parameters such as T{sub eff}, surface gravity, and clouds on spectral morphology. We report bolometric corrections in J for both field age and young objects and find differences of up to a magnitude for late-L dwarfs. Our correction in Ks shows a larger dispersion but not necessarily a different relationship for young and field age sequences. We also characterize the NIR–MIR reddening of low gravity L dwarfs and identify a systematically cooler T{sub eff} of up to 300 K from field age objects of the same spectral type and 400 K cooler from field age objects of the same M{sub H} magnitude.

  6. National survey on edentulism and its geographic distribution, among Mexicans 18 years of age and older (with emphasis in WHO age groups).

    PubMed

    Medina-Solís, C E; Pérez-Núñez, R; Maupomé, G; Avila-Burgos, L; Pontigo-Loyola, A P; Patiño-Marín, N; Villalobos-Rodelo, J J

    2008-04-01

    To determine the prevalence of edentulism in adults aged 18 years and older in Mexico and to describe its distribution in 20 of the 32 States in Mexico, highlighting the experience in the WHO age groups. A secondary analysis of the National Performance Evaluation Survey 2002-2003 (representative at the state level and part of the Word Health Survey) was undertaken. The sample design was probabilistic, stratified and through conglomerates. Data on dental conditions were available only for 20 of the 32 states of Mexico, leading to a total of 24 159 households (N = 54 638 654). The percentage of edentulism was determined as the proportion of subjects that self-reported complete loss of teeth. Data were analyzed using the SVY module for complex surveys in STATA 8.2. The mean age was 41.3 +/- 17.0 years (range 18-99). An estimated 6.3% (N = 3 437 816) of the population > or =18 years was edentulous. Lowest prevalences were observed in the states of Tlaxcala, Puebla and the Estado de Mexico with 3.4%, 3.8% and 4.5%, respectively. Highest prevalences were observed in San Luis Potosí, Colima, and Michoacán with 10.3%, 10.2% and 10.1%, respectively. Following the WHO age groups, the prevalence ranged from 2.4% in the 35-44 group through 25.5% in the 65-74 group. No obvious association between socio-economic and socio-demographic indicators at the state level and prevalence of edentulism was found. The prevalence of complete tooth loss observed in the present study varied greatly across states, although no straightforward association was found with socio-economic and socio-demographic indicators at the state level. This study could serve as a baseline to enable future evaluations of the oral status of Mexican adults and elders, following WHO age groups.

  7. Trends in the Distribution of Gestational Age and Contribution of Planned Births in New South Wales, Australia

    PubMed Central

    Nassar, Natasha; Schiff, Michal; Roberts, Christine L.

    2013-01-01

    Background There is concern that the rate of planned births (by pre-labour caesarean section or induction of labour) is increasing and that the gestation at which they are being conducted is decreasing. The aim of this study was to describe trends in the distribution of gestational age, and assess the contribution of planned birth to any such changes. Methods We utilised the New South Wales (NSW) Perinatal Data Collection to undertake a population-based study of all births in NSW, Australia 1994–2009. Trends in gestational age were determined by year, labour onset and plurality of birth. Results From 1994–2009, there was a gradual and steady left-shift in overall distribution of gestational age at birth, with a decline in the modal gestational age from 40 to 39 weeks. For singletons, there was a steady but significant reduction in the proportion of spontaneous births. Labour inductions increased in the proportion performed, with a gradual and changing shift in the distribution from a majority at 40 weeks to an increase at both 37–39 weeks and 41 weeks gestation. The proportion of pre-labour caesareans also increased steadily at each gestational age and doubled since 1994, with most performed at 39 weeks in 2009 compared with 38 weeks up to 2001. Conclusions Findings suggest a changing pattern towards births at earlier gestations, fewer births commencing spontaneously and increasing planned births. Factors associated with changing clinical practice and long-term implications on the health and well-being of mothers and babies should be assessed. PMID:23437101

  8. Distribution of blood lead levels in a birth cohort of New Zealanders at age 21.

    PubMed Central

    Fawcett, J P; Williams, S M; Heydon, J L; Walmsley, T A; Menkes, D B

    1996-01-01

    Little is known about lead exposure in the general population of young adults. In this study, whole blood lead concentration (PbB) was determined in a sample of the Dunedin Multidisciplinary Health and Development Study, a well-documented birth cohort of New Zealanders aged 21 years in 1993-1994. PbB in those who consented to venipuncture at 21 years of age (n = 779; 411 males, 368 females) was compared to PbB for the same cohort at age 11 years. The PbB at age 21 ranged from 0.4 to 56 micrograms/dl with a geometric mean of 4.5 micrograms/dl (95% CI, 4.3-4.7 micrograms/dl). Only three individuals had a PbB above 30 micrograms/dl. Males had significantly higher PbB than females (geometric mean 6.0 vs. 3.2 micrograms/dl; p < 0.0001). The PbB at age 21 was 53% lower than in the same individuals at age 11 (geometric mean 4.8 vs. 10.2 micrograms/dl; p < 0.001; n = 480) and the correlation between corresponding values was weak (r = 0.19; p < 0.001). PbB at age 21 showed significant associations with high risk occupational activities, recreational exposure, domicile close to a main road, smoking, and male sex. Blood lead concentrations continue to fall in New Zealand, but occupational and recreational activities remain a significant source of lead exposure. Images Figure 1. PMID:9118875

  9. Assessing variation in skeletal production from surface death assemblages on the basis of age-frequency distributions

    NASA Astrophysics Data System (ADS)

    Tomasovych, Adam; Kidwell, Susan M.; Foygel Barber, Rina

    2015-04-01

    Age-frequency distributions of dead skeletal material that capture information on the elapsed time since death of individuals on the landscape or seabed provide decadal- to millennial-scale windows into the history of production and on the processes that lead to skeletal disintegration and burial. However, models quantifying the dynamics of skeletal loss assumed that skeletal production has been constant during accumulation of death assemblages. Here, we assess the joint effects of temporally-variable production and skeletal loss on the shape of postmortem age-frequency distributions. We show that the modes of such distributions will tend to be shifted to younger age cohorts relative to the true timing of past production pulses. This shift in the timing of a past production will be higher where loss rates are high and/or the rate of decline in production is slow. We apply the models combining the dynamic of loss and production to death assemblages with the deposit-feeding bivalve Nuculana taphria from the Southern California continental shelf, finding that (1) an onshore-offshore gradient in time averaging is dominated by a gradient in the timing of production, corresponding to the tracking of shallow-water habitats under a sea-level rise, and (2) model estimates of the timing of past production are in good agreement with an independent sea-level curve.

  10. Age-distribution estimation for karst groundwater: Issues of parameterization and complexity in inverse modeling by convolution

    NASA Astrophysics Data System (ADS)

    Long, Andrew J.; Putnam, Larry D.

    2009-10-01

    SummaryConvolution modeling is useful for investigating the temporal distribution of groundwater age based on environmental tracers. The framework of a quasi-transient convolution model that is applicable to two-domain flow in karst aquifers is presented. The model was designed to provide an acceptable level of statistical confidence in parameter estimates when only chlorofluorocarbon (CFC) and tritium ( 3H) data are available. We show how inverse modeling and uncertainty assessment can be used to constrain model parameterization to a level warranted by available data while allowing major aspects of the flow system to be examined. As an example, the model was applied to water from a pumped well open to the Madison aquifer in central USA with input functions of CFC-11, CFC-12, CFC-113, and 3H, and was calibrated to several samples collected during a 16-year period. A bimodal age distribution was modeled to represent quick and slow flow less than 50 years old. The effects of pumping and hydraulic head on the relative volumetric fractions of these domains were found to be influential factors for transient flow. Quick flow and slow flow were estimated to be distributed mainly within the age ranges of 0-2 and 26-41 years, respectively. The fraction of long-term flow (>50 years) was estimated but was not dateable. The different tracers had different degrees of influence on parameter estimation and uncertainty assessments, where 3H was the most critical, and CFC-113 was least influential.

  11. Age-distribution estimation for karst groundwater: Issues of parameterization and complexity in inverse modeling by convolution

    USGS Publications Warehouse

    Long, A.J.; Putnam, L.D.

    2009-01-01

    Convolution modeling is useful for investigating the temporal distribution of groundwater age based on environmental tracers. The framework of a quasi-transient convolution model that is applicable to two-domain flow in karst aquifers is presented. The model was designed to provide an acceptable level of statistical confidence in parameter estimates when only chlorofluorocarbon (CFC) and tritium (3H) data are available. We show how inverse modeling and uncertainty assessment can be used to constrain model parameterization to a level warranted by available data while allowing major aspects of the flow system to be examined. As an example, the model was applied to water from a pumped well open to the Madison aquifer in central USA with input functions of CFC-11, CFC-12, CFC-113, and 3H, and was calibrated to several samples collected during a 16-year period. A bimodal age distribution was modeled to represent quick and slow flow less than 50 years old. The effects of pumping and hydraulic head on the relative volumetric fractions of these domains were found to be influential factors for transient flow. Quick flow and slow flow were estimated to be distributed mainly within the age ranges of 0-2 and 26-41 years, respectively. The fraction of long-term flow (>50 years) was estimated but was not dateable. The different tracers had different degrees of influence on parameter estimation and uncertainty assessments, where 3H was the most critical, and CFC-113 was least influential.

  12. Identification of the most common cutaneous neoplasms in dogs and evaluation of breed and age distributions for selected neoplasms.

    PubMed

    Villamil, J Armando; Henry, Carolyn J; Bryan, Jeffrey N; Ellersieck, Mark; Schultz, Loren; Tyler, Jeff W; Hahn, Allen W

    2011-10-01

    OBJECTIVE-To identify the most common cutaneous neoplasms in dogs and evaluate breed and age distributions for selected neoplasms. DESIGN-Retrospective epidemiological study. SAMPLE-Records available through the Veterinary Medical Database of dogs examined at veterinary teaching hospitals in North America between 1964 and 2002. PROCEDURES-Information on tumor type and patient breed and age was collected. Incidence and odds ratios with 95% confidence intervals were calculated. RESULTS-Records of 1,139,616 dogs were reviewed. Cutaneous neoplasms were diagnosed in 25,996 of these dogs; records for the remaining 1,113,620 dogs did not indicate that cutaneous neoplasms had been diagnosed, and these dogs were considered controls. The most frequent age range for dogs with cutaneous neoplasms was 10 to 15 years. Lipoma, adenoma, and mast cell tumor were the most common skin tumor types. CONCLUSIONS AND CLINICAL RELEVANCE-Results supported previously reported data regarding cutaneous neoplasia in dogs but provided updated information on the most common skin tumors and on age and breed distributions.

  13. Incidence, and Gender, Age and Ethnic Distribution of Sarcomas in the Republic of Suriname from 1980 to 2008

    PubMed Central

    Mans, DRA; Lall, AE Budhu; Macnack, VL; van Tholl, JA; Zandveld, EB; Vrede, MA

    2014-01-01

    Objective: We report on the incidence and the gender, age and ethnic distribution of sarcomas diagnosed between 1980 and 2008 in the multi-ethnic Republic of Suriname. Methods: Total and average yearly number of cases, crude rates, as well as relevant population data were derived from the records of the Pathologic Anatomy Laboratory and the General Bureau of Statistics, respectively, and stratified according to gender, age groups 0–19, 20–49 and 50+ years, and the largest ethnic groups (Hindustani, Creole, Javanese and Maroons). Results: Between 1980 and 2008, 258 sarcomas were diagnosed in Suriname, ie at a frequency of nine per year and an annual rate of two per 100 000. Overall, there was 0.9 male per female, two to four cases per year in each age group, and one to three patients in each ethnic group. Soft-tissue sarcomas comprised approximately 80% of overall cases, with a male/female ratio that was approximately 0.5; almost 90% of patients were older than 20 years; more than one-third was Creole. Leiomyosarcoma, fibrosarcoma and liposarcoma were most frequently encountered (90 cases), particularly above 20 years of age, while leiomyosarcomas seemed, additionally, more common in women and Creoles or Maroons. The most numerous bone tumours were primitive neuroectodermal tumour/Ewing tumour and osteosarcoma (37 cases). They were more common in males, the youngest age group, and Hindustanis and Creoles. Conclusions: The incidence of sarcomas in Suriname, and their gender, age and ethnic distribution in general, seemed comparable with international data. The main exception might be leiomyosarcoma which might have a predilection for Afro-Surinamese. PMID:25303244

  14. Relationship of oral cancer with age, sex, site distribution and habits.

    PubMed

    Patel, Mandakini Mansukh; Pandya, Amrish N

    2004-04-01

    Many studies are carried out regarding age incidence, tobacco smoking and sites of oral cancer, but in Gujarat tobacco chewing in form of Gutkha is more common than smoking and start during preteen years. Tobacco chewing causing chronic inflammation, submucous fibrosis and oral cancer. This study was conducted on 504 patients to find out if there is increasing incidence of oral cancer in lower age group and its relation with sex as well which site was commonly affected. There was statistically significant increase in oral cancer in lower age group, and anatomically anterior part of oral cavity showed involvement in 61.32% of cases. Though males were affected more but female cases were 25%. So tobacco chewing has got detrimental effect on oral cavity.

  15. Distribution of uranium in drinking water and associated age-dependent radiation dose in India.

    PubMed

    Sahoo, S K; Mohapatra, S; Chakrabarty, A; Sumesh, C G; Jha, V N; Tripathi, R M; Puranik, V D

    2009-09-01

    Exposure due to natural radiation is of particular importance because it accounts for the largest contribution (nearly 85 %) to the total collective dose of the world population. An attempt has been made to present the feasibility of uranium occurrence in drinking water samples from different states of India, by laser-induced fluorimetry. The associated age-dependent radiation dose was estimated by taking the prescribed water intake values of different age groups. The concentration of uranium obtained, i.e. 0.1 +/- 0.01 to 19.6 +/- 1.8 microg l(-1), is well below the drinking water guideline value of 30 microg l(-1). The annual ingestion dose due to uranium in drinking water for various age groups is found to vary from 0.14 to 48 microSv y(-1).

  16. The Prevalence and Distribution of Aging-Friendly Human Resource Practices.

    PubMed

    Segel-Karpas, Dikla; Bamberger, Peter A; Bacharach, Samuel B

    2015-07-01

    The aging of the workforce in the developed world has prompted organizations to implement human resource (HR) policies and practices encouraging older workers to defer retirement. However, little is known about the prevalence of such practices, and the organizational factors associated with their adoption. In this study, we used data collected from 2008 to 2009 from a national probability sample of retirement eligible workers in the United States (N = 407) to assess the prevalence of aging-friendly human resource practices (AFHRP), and their organizational predictors. Results indicate that employee wellness programs, unpaid leave, and reassignment based on physical needs are among the most prevalent AFHRP. However, in the vast majority of enterprises, AFHRP are limited. Results also indicate that projected organizational growth and a focus on internal labor market practices are positively associated with the adoption of AFHRP. Organizational size and the degree of unionization, while positively associated with aging-friendly benefits, were inversely associated with flexibility practices.

  17. Molecular seasonal, age and gender distributions of Cryptosporidium in diarrhoeic Egyptians: distinct endemicity.

    PubMed

    El-Badry, A A; Al-Antably, A S A; Hassan, M A; Hanafy, N A; Abu-Sarea, E Y

    2015-12-01

    Cryptosporidiosis is a worldwide gastrointestinal disease caused by the protozoan Cryptosporidium parasite. It has a broad range of seasonal and age-related prevalence. We aimed to study the molecular prevalence and seasonality of Cryptosporidium over a period of 1 year in a cohort of Egyptian diarrhoeic patients. Stool samples were collected from 865 diarrhoeic patients attending outpatient clinics of Cairo University hospitals, from all age groups over a 12-month period, examined microscopically for faecal Cryptosporidium oocysts by the acid-fast staining method and for copro-DNA detection using nested polymerase chain reaction (nPCR) assays. PCR-positive samples were characterised molecularly by nPCR-restriction fragment length polymorphism (RFLP) to determine Cryptosporidium genotypes. Cryptosporidium copro-DNA was detected in 19.5% of the collected samples throughout the year, with a major peak in summer (August) and a small rise in spring (April). Infection was mainly C. hominis (95.8%) followed by C. parvum (3.0%), affecting all age groups, with predominance in the pre-school age group, and decrease with age. There were statistically significant associations between the detection of Cryptosporidium and season, diarrhoea, patient age and drinking water, while gender, contact with animals and presence of mucus in stool showed no association. Cryptosporidium in diarrhoeic Egyptians was of distinct endemicity, with the bi-model mostly influenced by population dynamics, with a clear high prevalence in pre-school children and predominating anthroponotic (C. hominis) transmission throughout the year. The obtained results highlight Cryptosporidium as a water contaminant and an important cause of health problems in Egypt, necessitating further studies of the risk factors.

  18. Growth rate and age distribution of deep-sea black corals in the Gulf of Mexico

    USGS Publications Warehouse

    Prouty, N.G.; Roark, E.B.; Buster, N.A.; Ross, S.W.

    2011-01-01

    Black corals (order Antipatharia) are important long-lived, habitat-forming, sessile, benthic suspension feeders that are found in all oceans and are usually found in water depths greater than 30 m. Deep-water black corals are some of the slowest-growing, longest-lived deep-sea corals known. Previous age dating of a limited number of black coral samples in the Gulf of Mexico focused on extrapolated ages and growth rates based on skeletal 210Pb dating. Our results greatly expand the age and growth rate data of black corals from the Gulf of Mexico. Radiocarbon analysis of the oldest Leiopathes sp. specimen from the upper De Soto Slope at 300 m water depth indicates that these animals have been growing continuously for at least the last 2 millennia, with growth rates ranging from 8 to 22 µm yr–1. Visual growth ring counts based on scanning electron microscopy images were in good agreement with the 14C-derived ages, suggestive of annual ring formation. The presence of bomb-derived 14C in the outermost samples confirms sinking particulate organic matter as the dominant carbon source and suggests a link between the deep-sea and surface ocean. There was a high degree of reproducibility found between multiple discs cut from the base of each specimen, as well as within duplicate subsamples. Robust 14C-derived chronologies and known surface ocean 14C reservoir age constraints in the Gulf of Mexico provided reliable calendar ages with future application to the development of proxy records.

  19. Age and evolution of the lower NW flank of the Hecates Tholus volcano, Mars, based on crater size-frequency distribution on CTX images

    NASA Astrophysics Data System (ADS)

    de Pablo, M. A.; Michael, G. G.; Centeno, J. D.

    2013-09-01

    We present results of crater size-frequency distribution (SFD) analysis of the lower NW flank of the Hecates Tholus volcano, Elysium volcanic province of Mars, by the use of images acquired by the Context (CTX) instrument on board of Mars Reconnaissance Orbiter (6 m/pixel in resolution). Previous similar works were focused on the caldera complex of the volcano and some sectors of the lower NW flank. In this study, we analyzed the complete crater population of the main geomorphological units characterizing this sector of the volcano (de Pablo, M.A., Centeno, J.D. [2012]. Journal of Maps 8(3), 208-2014), discarding areas with possible clustering to avoid erroneous results. In total, 16 areas corresponding to 10 geomorphological units were measured and absolute model ages were derived for them. The ages correspond to ages of origin as well as of the end of resurfacing events, depending on the analyzed sector, resulting in some cases in more than one age per area. Our results are in general in agreement with previous works, and establish that the age of the origin of the Hecates Tholus volcano could be at least 3.8 Ga, with possible volcanic eruptions occurring until at least 335 Ma. Glacial events were also dated at 90 Ma, 30 Ma, 16 Ma, and 6 Ma, although it is possible to recognize ages which could also be related to the recent ice ages of Mars, between 2 and 0.4 Ma. Our results allowed us to determine that glacial processes could have been active as far back as 1.4 Ga, with possible events at intermediate ages. We deduced from the resulting ages and our observations on CTX images and the available geomorphological map of the area, that glacial-related processes played an important role in sculpting this flank of the volcano, and the possible level of the glacial sheet at the edge of the main depression of this flank was also deduced, with altitudes ranging between -2035 m and -2490 m, in agreement with the presence of smooth outcrops and roche moutonnées in the

  20. Delayed Adulthood, Delayed Desistance? Trends in the Age Distribution of Problem Behaviors

    ERIC Educational Resources Information Center

    Hayford, Sarah R.; Furstenberg, Frank F., Jr.

    2008-01-01

    As the transition to adulthood becomes more protracted and less orderly, fewer young people occupy adult roles and experience the social control associated with these roles. One might therefore expect behaviors associated with the teenage years to spill over into older age groups, reflecting postponed entrance into full social adulthood. We test…

  1. Age, Dose, and Time-Dependency of Plasma and Tissue Distribution of Deltamethrine in Immature Rats

    EPA Science Inventory

    The major objective of this project was to characterize the systemic disposition of the pyrethroid, deltamethrin (DLT), in immature rats, with emphasis on the age-dependence of target organ (brain) dosimetry. Postnatal day (PND) 10, 21, and 40 male Sprague-Dawley rats received 0...

  2. Age distribution of Serra Geral (Paraná) flood basalts, southern Brazil

    USGS Publications Warehouse

    Fodor, R.V.; McKee, E.H.; Roisenberg, A.

    1989-01-01

    We evaluated 193 K-Ar ages (10 newly determined) of basaltic and differentiated rocks of the Serra Geral (Paraná) flood-basalt province for indications of magmatism occurring systematically with progressive rifting and complete separation ( ≈130-105 Ma) of South America from Africa. The K-Ar ages represent basalt emplacement between 35° and 19°S covering about 1,200,000 km2. We note that volcanism appears ubiquitous across the province between about 140 and 115 Ma, and that there are no significant age differences within that relate directly to progressive south-to-north tectonism. On the other hand, the oldest samples, about 140–160 Ma, are among those nearest the Brazil coastline (rift margin), perhaps suggesting migration of activity away from the rift with time. Studies of other flood-basalt provinces now indicate short (<3 m.y.) eruption periods, thereby pointing to the need for re-examination of Serra Geral ages by 40Ar-39Ar incremental heating techniques.

  3. The age, growth, and distribution of the longjaw cisco, Leucichthys alpenae Koelz, in Lake Michigan

    USGS Publications Warehouse

    Jobes, Frank W.

    1949-01-01

    The sex ratio was determined from 7,457 individuals taken in 1930–1932 and 373 of the 1923 and 1928 specimens whose ages were determined. The percentage of females was relatively low in May 1931 and relatively high in October, but in the other months it remained more or less constant. In 1932 the femal

  4. Genetic linkage in the horse. II. Distribution of male recombination estimates and the influence of age, breed and sex on recombination frequency.

    PubMed

    Andersson, L; Sandberg, K

    1984-01-01

    In the present study an extensive amount of data, comprising more than 30,000 offspring in total, was analyzed to evaluate the influence of age and sex on the recombination frequency in the K-PGD segment of the equine linkage group (LG) I and the influence of age, breed and sex on recombination in the Al-Es segment of LG II. A highly significant sex difference is reported for both segments. Male and female recombination values in the K-PGD segment were estimated at 25.8 +/- 0.8 and 33.3 +/- 2.5%, respectively. Similarly, recombination was less frequent in the male (36.6 +/- 0.7%) than in the female (46.6 +/- 1.2%) in the Al-Es segment. Comparison of data from two Swedish horse breeds revealed no significant breed differences in either sex for recombination in the Al-Es segment. No evidence of an age effect was found in any segment or sex. The distribution of individual male recombination estimates was also investigated, and a significant heterogeneity among stallions was revealed in the K-PGD segment. The results are discussed in relation to previous studies on factors affecting recombination in mammals.

  5. AIDS in adults 50 years of age and over: characteristics, trends and spatial distribution of the risk1

    PubMed Central

    Nogueira, Jordana de Almeida; Silva, Antônia Oliveira; de Sá, Laísa Ribeiro; de Almeida, Sandra Aparecida; Monroe, Aline Aparecida; Villa, Tereza Cristina Scatena

    2014-01-01

    Objective to analyze the sociodemographic characteristics, epidemic trend and spatial distribution of the risk of AIDS in adults 50 years of age and over. Method population-based, ecological study, that used secondary data from the Notifiable Disease Information System (Sinan/AIDS) of Paraíba state from the period January 2000 to December 2010. Results during the study period, 307 cases of AIDS were reported among people 50 years of age or over. There was a predominance of males (205/66, 8%), mixed race, and low education levels. The municipalities with populations above 100 thousand inhabitants reported 58.5% of the cases. There was a progressive increase in cases among women; an increasing trend in the incidence (positive linear correlation); and an advance in the geographical spread of the disease, with expansion to the coastal region and to the interior of the state, reaching municipalities with populations below 30 thousand inhabitants. In some locations the risk of disease was 100 times greater than the relative risk for the state. Conclusion aging, with the feminization and interiorization of the epidemic in adults 50 years of age and over, confirms the need for the induction of affirmative policies targeted toward this age group. PMID:25029044

  6. Influence of Water Age on Reclaimed Water Quality in Distribution Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated chemical and microbial water quality changes in two reclaimed waters as a function of residence time within distribution systems or storage time in tanks. Here we report the microbial water quality changes with particular focus on the incidence of waterborne and waterbased patho...

  7. Prevalence of factor V Leiden and prothrombin G20210A mutation in a large French population selected for nonthrombotic history: geographical and age distribution.

    PubMed

    Mazoyer, Elisabeth; Ripoll, Laurent; Gueguen, René; Tiret, Laurence; Collet, Jean-Philippe; dit Sollier, Claire Bal; Roussi, Jacqueline; Drouet, Ludovic

    2009-10-01

    Among inherited risk factors for venous thrombosis, the most common are the FV-G1691A and FII-G20210A polymorphisms. The FV-G1691A polymorphism is preferentially observed in Europe, with differences between European countries. The FII-G20210A polymorphism is observed all over the world. The study was designed to compare the prevalence of the FV-G1691A and FII-G20210A polymorphisms in a large French population of unrelated individuals with no thrombotic disease history and to determine the age and geographical distributions. Over a period of 18 months, 6154 individuals were included throughout France and FV-G1691A and FII-G20210A polymorphisms were determined. The FV-G1691A prevalence was 3.84% (95% confidence interval 3.35-4.33) and the FII-G20210A prevalence was 3.07% (95% CI 2.63-3.51). A north-east/south-west gradient was observed in the FV-G1691A geographical distribution. No difference was observed in the geographical distribution of FII-G20210A polymorphism nor in the age distribution of the two polymorphisms. The prevalence of the two polymorphisms was similar whatever the blood group (O or non-O). Plasma D-dimers were significantly higher in healthy individuals with FV-G1691A but not in individuals with FII-G20210A. Thirty percent of variation in plasma prothrombin level was explained by environmental factors (serum cholesterol, age, oral contraception, hormonal replacement therapy, body mass index, sex) and genetic factors (FII-G20210A). As expected, individuals with FII-G20210A displayed higher plasma prothrombin level compared with individuals with wild type. However, this was not associated with a modification of the fibrin clot elastic modulus. This study shows a differential distribution of the two polymorphisms among the French territory. These polymorphisms confer a very mild hypercoagulable state as shown by the limited increased in basal D-dimers in mutated FV-G1691A populations and only a trend that does not reach statistical significance for FII

  8. Storage Dynamics and Non-Linear Connectivity between Landscape Units Control Runoff Generation and Stream Water Age Distributions

    NASA Astrophysics Data System (ADS)

    Soulsby, C.; Birkel, C.; Geris, J.; Tetzlaff, D.

    2015-12-01

    We assess the influence of storage dynamics and non-linearities in hydrological connectivity on runoff generation and stream water ages, using a long-term record of daily isotopes in precipitation and stream flow. These were used to test a parsimonious tracer-aided runoff model for a Scottish catchment. The model tracks tracers and the ages of water fluxes through and between conceptual stores representing steeper hillslopes, dynamically saturated riparian peatlands and deeper groundwater (i.e. the main landscape units involved in runoff generation). Storage is largest in groundwater and on the steep hillslopes, though most dynamic mixing occurs in smaller stores in the riparian peat. The model also couples the ecohydrological effects of different vegetation communities in contrasting landscape units, by estimating evaporation, resulting moisture deficits and the ages of evaporated waters, which also affect the generation and age of runoff. Both stream flow and isotope variations are well-captured by the model, and the simulated storage and tracer dynamics in the main landscape units are consistent with independent measurements. The model predicts the mean age of runoff as ~1.8 years. On a daily basis, this varies from ~1 month in storm events, when younger waters draining the riparian peatland dominate, to around 4 years in dry periods, when groundwater sustains flow. Hydrological connectivity between the units varies non-linearly with storage which depends upon antecedent conditions and event characteristics. This, in turn, determines the spatial distribution of flow paths and the integration of their contrasting non-stationary ages. Improving the representation of storage dynamics and quantifying the ages of water fluxes in such models gives a more complete conceptualisation of the importance of the soil water fluxes in critical zone processes and a framework for tracking diffuse pollutants in water quality assessment.

  9. Relationship of depression in participants with nonspecific acute or subacute low back pain and no-pain by age distribution

    PubMed Central

    Calvo-Lobo, Cesar; Vilar Fernández, Juan Manuel; Becerro-de-Bengoa-Vallejo, Ricardo; Losa-Iglesias, Marta Elena; Rodríguez-Sanz, David; Palomo López, Patricia; López López, Daniel

    2017-01-01

    Background and purpose Nonspecific low back pain (LBP) is the most prevalent musculoskeletal condition in various age ranges and is associated with depression. The aim of this study was to determine the Beck Depression Inventory (BDI) scores in participants with nonspecific LBP and no-pain by age distribution. Methods A case–control study was carried out following the Strengthening the Reporting of Observational Studies in Epidemiology criteria. A sample of 332 participants, divided into the following age categories: 19–24 (n=11), 25–39 (n=66), 40–64 (n=90), 65–79 (n=124), and ≥80 (n=41) years was recruited from domiciliary visits and an outpatient clinic. The BDI scores were self-reported in participants with nonspecific acute or subacute (≤3 months) LBP (n=166) and no-pain (n=166). Results The BDI scores, mean ± standard deviation, showed statistically significant differences (p<0.001) between participants with nonspecific acute or subacute LBP (9.590±6.370) and no-pain (5.825±5.113). Significantly higher BDI scores were obtained from participants with nonspecific acute and subacute LBP in those aged 40–64 years (p<0.001; 9.140±6.074 vs 4.700±3.777) and 65–79 years (p<0.001; 10.672±6.126 vs 6.210±5.052). Differences were not significant in younger patients aged 19–24 (p=0.494; 5.000±2.646 vs 8.250±7.498), 25–39 (p=0.138; 5.440±5.245 vs 3.634±4.397), and in those aged ≥80 years (p=0.094; 13.625±6.1331 vs 10.440±5.591). Conclusion Participants with nonspecific acute and subacute LBP present higher BDI depression scores, influenced by age distribution. Specifically, patients in the age range from 40 to 80 years with LBP could require more psychological care in addition to any medical or physical therapy. Nevertheless, physical factors, different outcomes, and larger sample size should be considered in future studies. PMID:28138263

  10. Limiting extensibility constitutive model with distributed fibre orientations and ageing of abdominal aorta.

    PubMed

    Horný, Lukáš; Netušil, Marek; Daniel, Matěj

    2014-10-01

    The abdominal aorta is susceptible to age-related pathological changes (arteriosclerosis, atherosclerosis, aneurysm, and tortuosity). Computational biomechanics and mechanobiology provide models capable of predicting mutual interactions between a changing mechanical environment and patho-physiological processes in ageing. However, a key factor is a constitutive equation which should reflect the internal tissue architecture. Our study investigates three microstructurally-motivated invariant-based hyperelastic anisotropic models suitable for description of the passive mechanical behaviour of the human abdominal aorta at a multiaxial state of stress known from recent literature. The three adopted models have also been supplemented with a newly proposed constitutive model (limiting extensibility with fibre dispersion). All models additively decouple the mechanical response of the isotropic (elastin and smooth muscle cells represented by the neo-Hookean term) and the anisotropic (collagen) parts. Two models use exponential functions to capture large strain stiffening ascribed to the engagement of collagen fibres into the load-bearing process. The other two models are based on the concept of limiting extensibility. Perfect alignment of reinforcing fibres with two preferred directions as well as fibre dispersion are considered. Constitutive models are calibrated to the inflation-extension response adopted from the literature based on the computational model of the residually-stressed thick-walled tube. A correlation analysis of determined material parameters was performed to reveal dependence on the age. The results of the nonlinear regression suggest that limiting fibre extensibility is the concept which is suitable to be used for the constitutive description of the aorta at multiaxial stress states and is highly sensitive to ageing-induced changes in mechanical response.

  11. Lunar crater arcs. [origins, distribution and age classification of Pre-Imbrian families

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.; Bulkley, E. O.

    1976-01-01

    An analysis has been made of the tendency of large lunar craters to lie along circles. A catalog of the craters at least 50 km in diameter was prepared first, noting position, diameter, rim sharpness and completion, nature of underlying surface, and geological age. The subset of those craters 50-400 km in diameter was then used as input to computer programs which identified each 'family' of four or more craters of selected geological age lying on a circular arc. For comparison, families were also identified for randomized crater models in which the crater spatial density was matched to that on the moon, either overall or separately for mare and highland areas. The observed frequency of lunar arcuate families was statistically highly significantly greater than for the randomized models, for craters classified as either late-pre-Imbrian (Nectarian), middle pre-Imbrian, or early pre-Imbrian, as well as for a number of larger age-classes. The lunar families tend to center in specific areas of the moon; these lie in highlands rather than maria and are different for families of Nectarian craters than for pre-Nectarian. The origin of the arcuate crater groupings is not understood.

  12. Cholesterol distribution in the bulk tissues of man: variation with age

    PubMed Central

    Crouse, J. R.; Grundy, S. M.; Ahrens, E. H.

    1972-01-01

    Lacking reliable data on cholesterol concentrations in muscle, adipose tissue, skin, and connective tissues (i.e., the “bulk tissues”) in “normal” man, we have completed these analyses in 21 men and 8 women who died suddenly and unexpectedly; their ages ranged from 23 to 78 yr. In 11 of these subjects aged 20-40 yr, the mean cholesterol concentrations ranged from 180-440 mg/100 g dry tissue. In contrast, in 13 subjects aged 60-80 yr the values were 23-28% higher in muscle, adipose, and skin, while in dura mater, biceps, and psoas tendons the concentrations were 130, 260, and 460% higher (respectively). Esterified cholesterol in these connective tissues was found to be the major contributor, increasing 5- to 10-fold in the older group as opposed to a less than 5-fold rise in free cholesterol. In view of the large proportion of total body weight represented by these tissues, it is clear that large amounts of cholesterol can be accumulated there over a lifetime; indeed, the dense connective tissues appear to act uniquely as a trap for cholesterol, especially in the esterified form. Whether analyses of tendinous tissues in man, accessible during life, mirror the pattern of cholesterol deposition in arterial connective tissue remains to be determined. PMID:5020436

  13. Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age.

    PubMed

    Kuang, Yuan Wen; Wen, Da Zhi; Zhou, Guoyi; Liu, Shi Zhong

    2007-02-01

    Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al.

  14. Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age.

    PubMed

    Kuang, Yuan Wen; Wen, Da Zhi; Zhou, Guo Yi; Liu, Shi Zhong

    2007-01-01

    Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd) and Al concentrations as well as values of Ca/Al in the tip, middle, base sections and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al.

  15. Spatial distributions of phosphorylated membrane proteins aquaporin 0 and MP20 across young and aged human lenses.

    PubMed

    Gutierrez, Danielle B; Garland, Donita L; Schwacke, John H; Hachey, David L; Schey, Kevin L

    2016-08-01

    In the human ocular lens it is now realized that post-translational modifications can alter protein function and/or localization in fiber cells that no longer synthesize proteins. The specific sites of post-translational modification to the abundant ocular lens membrane proteins AQP0 and MP20 have been previously identified and their functional effects are emerging. To further understand how changes in protein function and/or localization induced by these modifications alter lens homeostasis, it is necessary to determine the spatial distributions of these modifications across the lens. In this study, a quantitative LC-MS approach was used to determine the spatial distributions of phosphorylated AQP0 and MP20 peptides from manually dissected, concentric layers of fiber cells from young and aged human lenses. The absolute amounts of phosphorylation were determined for AQP0 Ser235 and Ser229 and for MP20 Ser170 in fiber cells from the lens periphery to the lens center. Phosphorylation of AQP0 Ser229 represented a minor portion of the total phosphorylated AQP0. Changes in spatial distributions of phosphorylated APQ0 Ser235 and MP20 Ser170 correlated with regions of physiological interest in aged lenses, specifically, where barriers to water transport and extracellular diffusion form.

  16. Simulating the grain-size distribution of Wisconsinan age glaciofluvial sediments: Applications to fluid transport

    SciTech Connect

    Webb, E.K.; Anderson, M.P. )

    1991-03-01

    A sedimentary deposition model, SEDSIM, was used to simulate the deposition of glaciofluvial sediments in south-central Wisconsin. These types of deposits are present at or near the surface over much of the northern United States and have a high contamination potential. They also represent relatively recent analogs for ancient braided stream systems. Sixty sediment samples were used to determine the average sediment properties for a facies assemblage located 8-10 km from the ice margin. A regional depositional system was simulated, using SEDSIM, to determine the range of input values that reproduced the observed average sediment characteristics. Progressively smaller scale models were constructed to produce more detailed estimates of the grain-size distribution. the grain-size estimates from the finest scale model were translated into relative hydraulic conductivity values using the method of Hazen. The resulting conductivities were incorporated into a fluid flow model to illustrate the control that heterogeneity of petrologic properties has on the direction and rate of fluid movement. This work indicates that a wide range of input parameters will reproduce the bulk sediment properties. Furthermore, small-scale features may not be reproduced under the assumptions incorporated in the current SEDSIM code. Thus, for sedimentary depositional models to be used to predict permeability and porosity distributions, or to interpret paleo-flow conditions, one must determine calibration targets that are more sensitive to flow parameters than bulk grain-size distributions.

  17. Distribution and Quantification of Choroidal Macrophages in Human Eyes With Age-Related Macular Degeneration

    PubMed Central

    McLeod, D. Scott; Bhutto, Imran; Edwards, Malia M.; Silver, Rachel E.; Seddon, Johanna M.; Lutty, Gerard A.

    2016-01-01

    Purpose Increasing evidence suggests a role for macrophages in the pathogenesis of age-related macular degeneration (AMD). This study examined choroidal macrophages and their activation in postmortem eyes from subjects with and without AMD. Methods Choroids were incubated with anti-ionized calcium-binding adapter molecule 1 (anti-IBA1) to label macrophages, anti-human leukocyte antigen-antigen D-related (anti-HLA-DR) as a macrophage activation marker, and Ulex europaeus agglutinin lectin to label blood vessels. Whole mounts were imaged using confocal microscopy. IBA1- and HLA-DR–positive (activated) cells were counted in submacula, paramacula, and nonmacula, and cell volume and sphericity were determined using computer-assisted image analysis. Results In aged control eyes, the mean number of submacular IBA1+ and HLA-DR+ macrophages was 433/mm2 and 152/mm2, respectively. In early AMD eyes, there was a significant increase in IBA1+ and HLA-DR+ cells in submacula compared to those in controls (P = 0.0015 and P = 0.008, respectively). In eyes with neovascular AMD, there were significantly more HLA-DR+ cells associated with submacular choroidal neovascularization (P = 0.001). Mean cell volume was significantly lower (P ≤ 0.02), and sphericity was significantly higher (P ≤ 0.005) in all AMD groups compared to controls. Conclusions The average number of IBA1+ macrophages in submacular and paramacular choroid was significantly higher in early/intermediate AMD compared to that in aged controls. HLA-DR+ submacular macrophages were significantly increased in all stages of AMD, and they were significantly more round and smaller in size in the submacular AMD choroid, suggesting their activation. These findings support the concept that AMD is an inflammatory disease. PMID:27802514

  18. Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime

    NASA Astrophysics Data System (ADS)

    Filippazzo, Joe; Rice, Emily L.; Faherty, Jacqueline K.; Cruz, Kelle L.; Godfrey, Paige A.; BDNYC

    2016-01-01

    The physical and atmospheric properties of ultracool dwarfs are deeply entangled due to the degenerate effects of mass, age, metallicity, clouds and dust, activity, rotation, and possibly even formation mechanism on observed spectra. Accurate determination of fundamental parameters for a wide diversity of objects at the low end of the IMF is thus crucial to testing stellar and planetary formation theories. To determine these quantities, we constructed and flux calibrated nearly-complete spectral energy distributions (SEDs) for 221 M, L, T, and Y dwarfs using published parallaxes and 0.3-40 μm spectra and photometry. From these homogeneous SEDs, we calculated bolometric luminosity (Lbol), effective temperature (Teff), mass, surface gravity, radius, spectral indexes, synthetic photometry, and bolometric corrections (BCs) for each object. We used these results to derive Lbol, Teff, and BC polynomial relations across the entire very-low-mass star/brown dwarf/planetary mass regime. We use a subsample of objects with age constraints based on nearby young moving group membership, companionship with a young star, or spectral signatures of low surface gravity to define new age-sensitive diagnostics and characterize the reddening of young substellar atmospheres as a redistribution of flux from the near-infrared into the mid-infrared. Consequently we find the SED flux pivots at Ks band, making BCKs as a function of spectral type a tight and age independent relationship. We find that young L dwarfs are systematically 300 K cooler than field age objects of the same spectral type and up to 600 K cooler than field age objects of the same absolute H magnitude. Finally, we present preliminary comparisons of these empirical results to best fit parameters from four different model atmosphere grids via Markov-Chain Monte Carlo analysis in order to create prescriptions for the reliable and efficient characterization of new ultracool dwarfs.

  19. Effects of Nitrogen Application Rate and Leaf Age on the Distribution Pattern of Leaf SPAD Readings in the Rice Canopy

    PubMed Central

    Yang, Jingping; Wang, Hua; Zou, Junliang; He, Junjun

    2014-01-01

    A Soil-Plant Analysis Development (SPAD) chlorophyll meter can be used as a simple tool for evaluating N concentration of the leaf and investigating the combined effects of nitrogen rate and leaf age on N distribution. We conducted experiments in a paddy field over two consecutive years (2008–2009) using rice plants treated with six different N application levels. N distribution pattern was determined by SPAD readings based on the temporal dynamics of N concentrations in individual leaves. At 62 days after transplantation (DAT) in 2008 and DAT 60 in 2009, leaf SPAD readings increased from the upper to lower in the rice canopy that received N levels of 150 to 375 kg ha−1The differences in SPAD readings between the upper and lower leaf were larger under higher N application rates. However, as plants grew, this atypical distribution of SPAD readings in canopy leaf quickly reversed to the general order. In addition, temporal dynamics of the leaf SPAD readings (N concentrations) were fitted to a piecewise function. In our model, changes in leaf SPAD readings were divided into three stages: growth, functioning, and senescence periods. The leaf growth period lasted approximately 6 days, and cumulative growing days were not affected by N application rates. The leaf functioning period was represented with a relatively stable SPAD reading related to N application rate, and cumulative growing days were extended with increasing N application rates. A quadratic equation was utilized to describe the relationship between SPAD readings and leaf age during the leaf senescence period. The rate of decrease in SPAD readings increased with the age of leaves, but the rate was slowed by N application. As leaves in the lower canopy were physiologically older than leaves in the upper canopy, the rate of decrease in SPAD readings was faster in the lower leaves. PMID:24520386

  20. Intrasite spatial variation of the Omo Kibish Middle Stone Age assemblages: artifact refitting and distribution patterns.

    PubMed

    Sisk, Matthew L; Shea, John J

    2008-09-01

    The middle-late Pleistocene Kibish Formation of the Lower Omo Valley (Ethiopia) contains some of the oldest dated Homo sapiens fossils. Archaeological excavations at the Omo Kibish between 2002 and 2003 recovered numerous stone tools from extensive horizontal exposures of two sites, KHS (dated to 195+/-5 kyr) and BNS (dated to at least 104+/-7 kyr). Analysis of artifact distributions, lithic-debris densities, and refitting artifact sets sheds light on site-formation processes. Both localities reveal weak patterns of differentiation, and BNS seems to have a preferred refit orientation.

  1. Distributed neural representations of logical arguments in school-age children

    PubMed Central

    Mathieu, Romain; Booth, James R.; Prado, Jérôme

    2016-01-01

    Children’s understanding of linear-order (e.g., Dan is taller than Lisa, Lisa is taller than Jess) and set-inclusion (i.e., All tulips are flowers, All flowers are plants) relationships is critical for the acquisition of deductive reasoning, i.e., the ability to reach logically valid conclusions from given premises. Behavioral and neuroimaging studies in adults suggest processing differences between these relations: While arguments that involve linear-orders may be preferentially associated with spatial processing, arguments that involve set-inclusions may be preferentially associated with verbal processing. In the present study, we used functional magnetic resonance imaging (fMRI) to investigate whether these processing differences appear during the period of elementary school in development. Consistent with previous studies in adults, we found that arguments that involve linear-order and set-inclusion relationships preferentially involve spatial and verbal brain mechanisms (respectively) in school-age children (9 to 14 year olds). Because this neural sensitivity was not related to age, it likely emerges before the period of elementary education. However, the period of elementary education might play an important role in shaping the neural processing of logical reasoning, as indicated by developmental changes in frontal and parietal regions that were dependent upon the type of relation. PMID:25355487

  2. [Age distribution of urinary tract infections (UTIs) and their severity grade in children (author's transl)].

    PubMed

    Elo, J; Tallgren, L G; Sarna, S

    1982-03-01

    Urinary tract infections in 339 children (77 boys and 262 girls) have been followed up. An excretory urography and a urethrocystography were done for all the children. The frequency of functional and anatomical abnormalities is given. The severity grade of UTI was determined according to the classification of Elo and Stenström. Almost all episodes of UTI among boys occurred during the first three years of life and were mostly severe. After the 3rd year of life the occurrence of UTI among the boys was sporadic. Among the girls the severe episodes dominates during the first three years of life, but after that the episodes tended to become milder in character becoming mostly asymptomatic. The peak of asymptomatic episodes among girls was at 10 years of age. After that age the number of episodes dropped abruptly. The classification used, based on the erythrocyte sedimentation rate (ESR) and on white blood cell count (WBC), has shown to be useful and makes it possible to differentiate between renal (pyelonephritic) episodes and the lower tract episodes.

  3. Spatial and Seasonal Distribution of American Whaling and Whales in the Age of Sail

    PubMed Central

    Smith, Tim D.; Reeves, Randall R.; Josephson, Elizabeth A.; Lund, Judith N.

    2012-01-01

    American whalemen sailed out of ports on the east coast of the United States and in California from the 18th to early 20th centuries, searching for whales throughout the world’s oceans. From an initial focus on sperm whales (Physeter macrocephalus) and right whales (Eubalaena spp.), the array of targeted whales expanded to include bowhead whales (Balaena mysticetus), humpback whales (Megaptera novaeangliae), and gray whales (Eschrichtius robustus). Extensive records of American whaling in the form of daily entries in whaling voyage logbooks contain a great deal of information about where and when the whalemen found whales. We plotted daily locations where the several species of whales were observed, both those caught and those sighted but not caught, on world maps to illustrate the spatial and temporal distribution of both American whaling activity and the whales. The patterns shown on the maps provide the basis for various inferences concerning the historical distribution of the target whales prior to and during this episode of global whaling. PMID:22558102

  4. Spatial and seasonal distribution of American whaling and whales in the age of sail.

    PubMed

    Smith, Tim D; Reeves, Randall R; Josephson, Elizabeth A; Lund, Judith N

    2012-01-01

    American whalemen sailed out of ports on the east coast of the United States and in California from the 18(th) to early 20(th) centuries, searching for whales throughout the world's oceans. From an initial focus on sperm whales (Physeter macrocephalus) and right whales (Eubalaena spp.), the array of targeted whales expanded to include bowhead whales (Balaena mysticetus), humpback whales (Megaptera novaeangliae), and gray whales (Eschrichtius robustus). Extensive records of American whaling in the form of daily entries in whaling voyage logbooks contain a great deal of information about where and when the whalemen found whales. We plotted daily locations where the several species of whales were observed, both those caught and those sighted but not caught, on world maps to illustrate the spatial and temporal distribution of both American whaling activity and the whales. The patterns shown on the maps provide the basis for various inferences concerning the historical distribution of the target whales prior to and during this episode of global whaling.

  5. A preliminary analysis of lunar extra-mare basalts - Distribution, compositions, ages, volumes, and eruption styles

    NASA Technical Reports Server (NTRS)

    Whitford-Stark, J. L.

    1982-01-01

    Extra-mare basalts occupy 8.5% of the lunar basalt area and comprise 1% of the total mare basalt volume. They are preferentially located where the crust is thin and topographically low. In terms of age, eruption style, and composition they are as variable as the mare basalts. In some instances extrusion in extra-mare craters was preceded by floor-fracturing whereas in other cases it apparently was not. The volume of lava erupted may have been controlled more by the volume of magma produced than by hydrostatic effects. A minimum of nearly 1300 separate basalt eruptions is indicated; the true value could be nearer 30,000 separate eruptions.

  6. Effect of age on body distribution of Tityustoxin from Tityus serrulatus scorpion venom in rats.

    PubMed

    Nunan, Elzíria A; Moraes, Márcio F D; Cardoso, Valbert N; Moraes-Santos, Tasso

    2003-06-06

    Previous research from our Laboratory has shown a greater susceptibility of young animals, when compared to adults, to envenomation by tityustoxin (TsTX), one of the main toxins from Tityus serrulatus scorpion venom. Our hypothesis is that a differential body distribution of TsTX among adult and young animals could account for the worse prognosis of scorpion envenomation in infants. Thus, TsTX labeled with technetium-99m was injected (6 microg, subcutaneous) in adult (150-160 day-old) and young (21-22 day-old) male rats. Groups of animals were sacrificed at different times after TsTX injection (0.08, 1.0, 3.0, 6.0, 12.0 and 24.0 hours) under Urethane anesthesia (140 mg/100 g, i.p.). The brain, heart, lungs, liver, kidneys, spleen and thyroid were excised and blood collected. Young rats presented a shorter latency toxin concentration peak in all studied organs except for the liver and the kidney, when compared to adults. The ratio between the area under the curve of the toxin concentration in each organ and that in blood (Kp) indicates higher accumulation in the organs of young animals mainly for brain, liver and heart. These observations suggest a faster toxin distribution in the organs of young rats. The higher uptake of TsTX in the brain is suggestive of a greater permeability for the toxin along the blood-brain barrier of young rats. In conclusion, the higher uptake in heart, together with data from the brain, may help to elucidate the clinical manifestations frequently observed in children under scorpion envenomation.

  7. Stream water age distributions controlled by storage dynamics and nonlinear hydrologic connectivity: Modeling with high‐resolution isotope data

    PubMed Central

    Birkel, C.; Geris, J.; Dick, J.; Tunaley, C.; Tetzlaff, D.

    2015-01-01

    Abstract To assess the influence of storage dynamics and nonlinearities in hydrological connectivity on time‐variant stream water ages, we used a new long‐term record of daily isotope measurements in precipitation and streamflow to calibrate and test a parsimonious tracer‐aided runoff model. This can track tracers and the ages of water fluxes through and between conceptual stores in steeper hillslopes, dynamically saturated riparian peatlands, and deeper groundwater; these represent the main landscape units involved in runoff generation. Storage volumes are largest in groundwater and on the hillslopes, though most dynamic mixing occurs in the smaller stores in riparian peat. Both streamflow and isotope variations are generally well captured by the model, and the simulated storage and tracer dynamics in the main landscape units are consistent with independent measurements. The model predicts that the average age of stream water is ∼1.8 years. On a daily basis, this varies between ∼1 month in storm events, when younger waters draining the hillslope and riparian peatland dominates, to around 4 years in dry periods when groundwater sustains flow. This variability reflects the integration of differently aged water fluxes from the main landscape units and their mixing in riparian wetlands. The connectivity between these spatial units varies in a nonlinear way with storage that depends upon precipitation characteristics and antecedent conditions. This, in turn, determines the spatial distribution of flow paths and the integration of their contrasting nonstationary ages. This approach is well suited for constraining process‐based modeling in a range of northern temperate and boreal environments. PMID:27478255

  8. Percentile Distributions of Birth Weight according to Gestational Ages in Korea (2010-2012)

    PubMed Central

    2016-01-01

    The Pediatric Growth Chart (2007) is used as a standard reference to evaluate weight and height percentiles of Korean children and adolescents. Although several previous studies provided a useful reference range of newborn birth weight (BW) by gestational age (GA), the BW reference analyzed by sex and plurality is not currently available. Therefore, we aimed to establish a national reference range of neonatal BW percentiles considering GA, sex, and plurality of newborns in Korea. The raw data of all newborns (470,171 in 2010, 471,265 in 2011, and 484,550 in 2012) were analyzed. Using the Korean Statistical Information Service data (2010–2012), smoothed percentile curves (3rd–97th) by GA were created using the lambda-mu-sigma method after exclusion and the data were distinguished by all live births, singleton births, and multiple births. In the entire cohort, male newborns were heavier than female newborns and singletons were heavier than twins. As GA increased, the difference in BW between singleton and multiples increased. Compared to the previous data published 10 years ago in Korea, the BW of newborns 22–23 gestational weeks old was increased, whereas that of others was smaller. Other countries' data were also compared and showed differences in BW of both singleton and multiple newborns. We expect this updated data to be utilized as a reference to improve clinical assessments of newborn growth. PMID:27247504

  9. Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in northern Alaska

    SciTech Connect

    Dusel-Bacon, C.; Brosge, W.P.; Till, A.B.; Doyle, E.O.; Mayfield, C.F.; Reiser, H.N.; Miller, T.P.

    1989-01-01

    Approximately half of the exposed bedrock in northern Alaska has been regionally metamorphosed. In the southern Brooks Range and on the Seward Peninsula, continental rocks experienced a clockwise pressure-temperature path that evolved during Middle Jurassic to late Early Cretaceous time from the low- to high-temperature subfacies of the blueschist facies and, finally, due to decreasing pressure, evolved to the greenschist facies. Metamorphism in the southern Brooks Range was associated with north-vergent compression along a south-dipping subduction zone that emplaced the oceanic rocks of the Angayucham terrane onto the continental margin. High-pressure metamorphism on the Seward Peninsula probably had a similar origin to that in the southern Brooks Range, but remnants of the overriding plate have not been identified, and the mechanism by which the high-pressure rocks in the two areas were separated is not known. In the Ruby geanticline, glaucophane, attesting to high-pressure metamorphism, is sporadically developed both within the continental rocks of the lower plate and, less commonly, near the base of the overlying oceanic thrust sheets. Although the majority of the metamorphic episodes that affected northern Alaska occurred during the Mesozoic, older episodes have been documented or are suspected in a few areas.

  10. The Spatio-temporal Distribution of Japanese Encephalitis Cases in Different Age Groups in Mainland China, 2004 – 2014

    PubMed Central

    Wang, Huanyu; Song, Miao; Li, Minghua; Fu, Shihong; Lv, Zhi; He, Ying; Lei, Wenwen; Wang, Bin; Lu, Xiaoqing; Liang, Guodong

    2016-01-01

    Background Japanese encephalitis (JE) is very prevalent in China, but the incidence of JE among children has been greatly reduced by extensive promotion of vaccinations. The incidence of JE among adults, however, has increased in some parts of China. Methods/Principal Findings Data on JE in mainland China, in terms of incidence, gender, and age, were collected between 2004 and 2014. We conducted spatial and temporal analyses on data from different age groups. Generally, children aged 0–15 years still represent the major population of JE cases in China, despite the gradual decrease in incidence over years. However, the incidence of JE among adults in several provinces is notably higher than the national average, especially during the epidemic waves in 2006, 2009, and 2013. The JE cases in the 0–15-year-old group are distributed mainly in the area south of the Yangtze River, with peak incidence occurring from July to September. In the adult group, especially for those over 40 years old, the JE cases are concentrated mainly in the area north of the Yangtze River. JE incidence in the adult group in September and October is significantly greater compared to the other groups. Further analysis using Local Indicators of Spatial Association (LISA) reveals that the distribution of adult JE cases in the six provinces north of the Yangtze River, between north 30–35° latitude and east 110–130° longitude, is a hotspot for adult JE cases. Conclusions/Significance The rate of JE case increase for adults is much greater than for children and has become a public health issue. Therefore, studies on the necessity and feasibility of vaccinating adults who live in JE-endemic areas, but have never been vaccinated for JE, should become a new focus of JE prevention in the future. PMID:27050414

  11. Prospective microglia and brain macrophage distribution pattern in normal rat brain shows age sensitive dispersal and stabilization with development.

    PubMed

    Ghosh, Payel; Mukherjee, Nabanita; Ghosh, Krishnendu; Mallick, Suvadip; Pal, Chiranjib; Laskar, Aparna; Ghosh, Anirban

    2015-09-01

    The monocytic lineage cells in brain, generally speaking brain macrophage and/or microglia show some dissimilar distribution patterns and disagreement regarding their origin and onset in brain. Here, we investigated its onset and distribution/colonization pattern in normal brain with development. Primarily, early and late embryonic stages, neonate and adult brains were sectioned for routine H/E staining; a modified silver-gold staining was used for discriminating monocytic lineage cells in brain; and TEM to deliver ultramicroscopic details of these cells in brain. Immunofluorescence study with CD11b marker revealed the distribution of active microglia/macrophage like cells. Overall, in early embryonic day 12, the band of densely stained cells are found at the margin of developing ventricles and cells sprout from there dispersed towards the outer edge. However, with development, this band shrunk and the dispersion trend decreased. The deeply stained macrophage like cell population migration from outer cortex to ventricle observed highest in late embryonic days, continued with decreased amount in neonates and settled down in adult. In adult, a few blood borne macrophage like cells were observed through the vascular margins. TEM study depicted less distinguishable features of cells in brain in early embryo, whereas from late embryo to adult different neuroglial populations and microglia/macrophages showed distinctive features and organization in brain. CD11b expression showed some similarity, though not fully, with the distribution pattern depending on the differentiation/activation status of these macrophage lineage cells. This study provides some generalized spatial and temporal pattern of macrophage/microglia distribution in rat brain, and further indicates some intrigue areas that need to be addressed.

  12. Data on the distribution of cancer incidence and death across age and sex groups visualized using multilevel spie charts.

    PubMed

    Feitelson, Dror G

    2016-04-01

    Cancer incidence and death statistics are typically recorded for multiple age and sex brackets, leading to large data tables which are difficult to digest. Effective visualizations of this data would allow practitioners, policy makers, and the general public to comprehend the data more readily and act on it appropriately. We introduce multilevel spie charts to create a combined visualization of cancer incidence and death statistics. Spie charts combine multiple pie charts, where the base pie chart (representing the general population) is used to set the angles of slices, and the superimposed ones use variable radii to portray the cancer data. Spie charts of cancer incidence and death statistics from Israel for 2009-2011 are used as an illustration. These charts clearly show various patterns of how cancer incidence and death distribute across age and sex groups, illustrating (1) absolute numbers and (2) rates per 100,000 population for different age and sex brackets. In addition, drawing separate charts for different cancer types illustrates relative mortality, both (3) across cancer types and (4) mortality relative to incidence. Naturally, this graphical depiction can be used for other diseases as well.

  13. Age-dependent changes in neuronal distribution of CacyBP/SIP: comparison to tubulin and the tau protein.

    PubMed

    Filipek, Anna; Schneider, Gabriela; Mietelska, Anna; Figiel, Izabela; Niewiadomska, Grazyna

    2008-09-01

    CacyBP/SIP was originally identified as an S100A6 (calcyclin) target and later on as a Siah-1 interacting protein. Recently, we have shown that CacyBP/SIP interacts with tubulin, which suggests its involvement in the reorganization of microtubules. In this work we examined the localization of CacyBP/SIP in cultured neurons and in brain neurons of young and aged rats, and compared this localization with that of tubulin and the tau protein. We have found that in neurons of young rats CacyBP/SIP, tubulin and tau are present in the cytoplasm and in the neuronal processes, whereas in aged animals CacyBP/SIP and tau are mainly seen in the cytoplasm of the neuronal somata. In aged rats, these changes are also accompanied by a different localization pattern of tubulin. Thus, our results show that localization of CacyBP/SIP in brain neurons is similar to that observed for tau and tubulin, which points to the involvement of CacyBP/SIP in cytoskeletal physiology.

  14. Dyslexic and skilled reading dynamics are self-similar.

    PubMed

    Holden, John G; Greijn, Lieke T; van Rooij, Marieke M J W; Wijnants, Maarten L; Bosman, Anna M T

    2014-10-01

    The shape of a word pronunciation time distribution supplies information about the dynamic interactions that support reading performance. Speeded word-naming pronunciation and response time distributions were collected from 20 sixth grade Dutch students with dyslexia and 23 age-matched controls. The participants' pronunciation times were modeled and contrasted with a lognormal inverse power-law mixture distribution. Identical contrasts were also conducted on the same participants' response time distributions derived from flanker, color-naming, and arithmetic tasks. Results indicated that children with dyslexia yield slower, broader, and more variable pronunciation time distributions than their age-matched counterparts. This difference approximated a self-similar rescaling between the two group's aggregate pronunciation time distributions. Moreover, children with dyslexia produced similar, but less prominent trends toward slower and more variable performance across the three non-reading tasks. The outcomes support a proportional continuum rather than a localized deficit account of dyslexia. The mixture distribution's success at describing the participants' pronunciation and response time distributions suggests that differences in proportional contingencies among low-level neurophysiological, perceptual, and cognitive processes likely play a prominent role in the etiology of dyslexia.

  15. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    USGS Publications Warehouse

    Zeigenfuss, Linda C.; Binkley, Dan; Tuskan, Gerald A.; Romme, William H.; Yin, Tongming; DiFazio, Stephen; Singer, Francis J.

    2008-01-01

    Lack of recruitment and canopy replacement of aspen (Populus tremuloides) stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado have been a cause of concern for more than 70 years. We used a combination of traditional dendrochronology and genetic techniques as well as measuring the characteristics of regenerating and nonregenerating stands on the elk winter range to determine when and under what conditions and estimated elk densities these stands established and through what mechanisms they may regenerate. The period from 1975 to 1995 at low elevation on the east side had 80-95 percent fewer aspen stems than would be expected based on the trend from 1855 through 1965. The age structure of aspen in the park indicates that the interacting effects of fires, elk population changes, and livestock grazing had more-or-less consistent effects on aspen from 1855 to 1965. The lack of a significant change in aspen numbers in recent decades in the higher elevation and west side parts of the park supports the idea that the extensive effects of elk browsing have been more important in reducing aspen numbers than other factors. The genetic variation of aspen populations in RMNP is high at the molecular level. We expected to find that most patches of aspen in the park were composed of a single clone of genetically identical trees, but in fact just 7 percent of measured aspen patches consisted of a single clone. A large frequency of polyploid (triploid and tetraploid) genotypes were found on the low elevation, east-side elk winter range. Nonregenerating aspen stands on the winter range had greater annual offtake, shorter saplings, and lower density of mid-height (1.5-2.5 m) saplings than regenerating stands. Overwinter elk browsing, however, did not appear to inhibit the leader length of aspen saplings. The winter range aspen stands of RMNP appear to be highly resilient in the face of

  16. Spatial distributions of glutathione and its endogenous conjugates in normal bovine lens and a model of lens aging.

    PubMed

    Nye-Wood, Mitchell G; Spraggins, Jeffrey M; Caprioli, Richard M; Schey, Kevin L; Donaldson, Paul J; Grey, Angus C

    2016-11-09

    Glutathione (GSH) is the archetypal antioxidant, and plays a central role in the protection of the ocular lens from cataract formation. High levels of GSH are maintained in the transparent lens, but with advancing age, GSH levels fall in the lens nucleus relative to outer cortical cells, thereby exposing the nucleus of the lens to the damaging effects of oxygen radicals, which ultimately leads to age-related nuclear (ARN) cataract. Under normal conditions, GSH also forms endogenous conjugates to detoxify the lens of reactive cellular metabolites and to maintain cell homeostasis. Due to the intrinsic gradient of lens fibre cell age, the lens contains distinct regions with different metabolic requirements for GSH. To investigate the impact of fibre cell and lens aging on the varied roles that GSH plays in the lens, we have utilised high mass resolution MALDI mass spectrometry profiling and imaging analysis of lens tissue sections. High Dynamic Range (HDR)-MALDI FTICR mass spectrometry was used as an initial screening method to detect regional differences in lens metabolites from normal bovine lenses and in those subjected to hyperbaric oxygen as a model of lens aging. Subsequent MALDI imaging analysis was used to spatially map GSH and its endogenous conjugates throughout all lenses. Accurate mass measurement by MALDI FTICR analysis and LC-MS/MS mass spectrometry of lens region homogenates were subsequently used to identify endogenous GSH conjugates. While the distribution and relative abundance of GSH-related metabolic intermediates involved in detoxification pathways remained relatively unchanged upon HBO treatment, those involved in its antioxidant function were altered under conditions of oxidative stress. For example, reduced glutathione levels were decreased in the lens cortex while oxidised glutathione levels were elevated in the lens outer cortex upon HBO treatment. Interestingly, cysteineglutathione disulfide, was detected in the inner cortex of the normal

  17. Influence of the age and sex of human hosts on the distribution of Escherichia coli ECOR groups and virulence traits.

    PubMed

    Gordon, David M; Stern, Steven E; Collignon, Peter J

    2005-01-01

    Escherichia coli were isolated from the faeces of 266 individuals living in the Canberra region of Australia. The isolates were characterized for their ECOR group membership (A, B1, B2 or D) and for the presence of 29 virulence-associated traits. Overall, 19.5 % of the strains were members of group A, 12.4 % B1, 45.1 % B2 and 22.9 % D. The frequency with which strains belonging to the four ECOR groups were observed varied with the age and sex of the hosts from which they were isolated. In males, the probability of isolating A or D strains increased with host age, whilst the probability of detecting a group B2 strain declined. In females, the probability of recovering A or B2 strains increased with increasing host age and there was a concomitant decline in the likelihood of isolating B1 or D strains. Of the 29 virulence-associated traits examined, 24 were detected in more than one strain. The likelihood of detecting most traits varied with a strain's ECOR membership, with the exception of afa/draBC, astA, cvaC, eaeA, iss and iutA, for which there was no statistically significant evidence of an association with ECOR group. The frequency with which fimH, iha, eaeA, iroN, hlyD, iss, ompT and K1 were detected in a strain depended on the age or sex of the host from which the strain was isolated. In group B2 strains many of the virulence traits were non-randomly associated, with some co-occurring in a strain less often than expected by chance, whilst others were co-associated. In 17 cases, the extent to which two virulence traits were co-associated was found to depend on host sex and age. The results of this study suggest that the morphological, physiological and dietary differences that occur among human individuals of different sex or age may influence the distribution of E. coli genotypes.

  18. Distribution patterns, properties and ages of Pleistocene periglacial slope deposits in the eastern Rhenish Massif

    NASA Astrophysics Data System (ADS)

    Sauer, Daniela; Scholten, Thomas; Felix-Henningsen, Peter; Kadereit, Annette

    2010-05-01

    between an Upper Layer and the rock in all expositions. The total thickness of the PPSD sequence on quartzite grows downslope, mainly due to an increasing thickness of the Basal Layer. In addition, Intermediate Layers contribute to the thickness of the PPSD profile on the lower slopes in SE- and NE-exposition. This can be partly explained by enhanced loess sedimentation on the leeward slopes in an area of predominantly westerly winds. Additionally, sediments were best preserved on E slopes, because thaw-processes leading to remobilization and removal of formerly deposited sediments were less intensive there. In most of the upper slope profiles on diabase, an Upper Layer covers directly the rock. A Basal Layer starts between the upper and middle slope sites. In SE exposition, an Intermediate Layer appears already on the mid slope. The total thickness of the PPSD sequence reaches its maximum on the footslope, where several Basal Layers may occur on top of one another. With regard to the formation time of the different layers, it is assumed that Basal and Intermediate Layers could have formed during several cold periods of the Pleistocene. It is however most likely that pre-Wurmian layers were preserved only on footslopes, where several Basal Layers occur on top of each other. All other layers are probably of Wurmian age, because the steep slopes did not allow preservation of older sediments (in contrast to areas of Tertiary peneplains in the central Rhenish Massif). Infrared stimulated luminescence datings confirm the assumption that the Upper Layer was subject to gelisolifluction for the last time during the Younger Dryas, and that the remarkably constant thickness of about 50 cm of the Upper Layer represents the thickness of the active layer at that time.

  19. Distributions.

    ERIC Educational Resources Information Center

    Bowers, Wayne A.

    This monograph was written for the Conference of the New Instructional Materials in Physics, held at the University of Washington in summer, 1965. It is intended for students who have had an introductory college physics course. It seeks to provide an introduction to the idea of distributions in general, and to some aspects of the subject in…

  20. Age-related development and tissue distribution of T cell markers (CD4 and CD8a) in Chinese goose.

    PubMed

    Chen, Shun; Zhou, Qin; Cheng, Beibei; Yan, Bing; Yan, Xiaoling; Zhao, Qiurong; Wang, Mingshu; Jia, Renyong; Zhu, Dekang; Liu, Mafeng; Chen, Xiaoyue; Cheng, Anchun

    2015-06-01

    Aquatic birds play n critical role in the transmission and dissemination of many important pathogens such as avian influenza virus. The cell-mediated immunity is very important in eliminating the intracellular antigens. Expression of CD4 and CD8 on T cell surface is essential for cell-mediated immune defence and T-cell development. However, the ontogeny of T lymphocytes in waterfowl is scarce and fragmentary. To address these questions, here we report the development and tissues distribution of CD4 and CD8α in goose embryo, gosling and goose by immunocytochemistry assay using monoclonal antibodies. Moreover, the age-related mRNA level of goose CD4 and CD8α in different immune tissues were study by real time quantitative PCR. Our results suggested that the high expression of CD4 and CD8α were readily found in thymus, which peaked at the first week post-hatch. And the highest expression level of CD4 and CD8α were detected in bursa of Fabricius, caecal tonsils, spleen and intestine at the second week, after that the expression level were gradually decreased. Interestingly, the remarkably high expression of CD4 and CD8α in Harderian gland were detected at the first week, which is about hundreds times more than that in other tissues. Our findings demonstrated that the development and the distribution of CD4 and CD8α are partly changed in an age-related way. Moreover, the histological morphogenesis of immune tissues were also discussed. Our results may shed lights on the better understand of T-cell mediate immunity in goose.

  1. Age, geochemical composition, and distribution of Oligocene ignimbrites in the northern Sierra Nevada, California: Implications for landscape morphology, elevation, and drainage divide geography of the Nevadaplano

    USGS Publications Warehouse

    Cassel, E.J.; Calvert, A.T.; Graham, S.A.

    2009-01-01

    To gain a better understanding of the topographic and landscape evolution of the Cenozoic Sierra Nevada and Basin and Range, we combine geochemical and isotopic age correlations with palaeoaltimetry data from widely distributed ignimbrites in the northern Sierra Nevada, California. A sequence of Oligocene rhyolitic ignimbrites is preserved across the modern crest of the range and into the western foothills. Using trace and rare earth element geochemical analyses of volcanic glass, these deposits have been correlated to ignimbrites described and isotopically dated in the Walker Lane fault zone and in central Nevada (Henry et al., 2004, Geologic map of the Dogskin mountain quadrangle; Washoe County, Nevada; Faulds et al., 2005, Geology, v. 33, p. 505-508). Ignimbrite deposits were sampled within the northern Sierra Nevada and western Nevada, and four distinct geochemical compositions were identified. The majority of samples from within the northern Sierra Nevada have compositions similar to the tuffs of Axehandle Canyon or Rattlesnake Canyon, both likely sourced from the same caldera complex in either the Clan Alpine Mountains or the Stillwater Range, or to the tuff of Campbell Creek, sourced from the Desatoya Mountains caldera. New 40Ar/39Ar age determinations from these samples of 31.2, 30.9, and 28.7Ma, respectively, support these correlations. Based on an Oligocene palinspastic reconstruction of the region, our results show that ignimbrites travelled over 200km from their source calderas across what is now the crest of the Sierra Nevada, and that during that time, no drainage divide existed between the ignimbrite source calderas in central Nevada and sample locations 200km to the west. Palaeoaltimetry data from Sierra Nevada ignimbrites, based on the hydrogen isotopic composition of hydration water in glass, reflect the effect of a steep western slope on precipitation and indicate that the area had elevations similar to the present-day range. These combined

  2. Age-specific absolute and relative organ weight distributions for B6C3F1 mice.

    PubMed

    Marino, Dale J

    2012-01-01

    The B6C3F1 mouse is the standard mouse strain used in toxicology studies conducted by the National Cancer Institute (NCI) and the National Toxicology Program (NTP). While numerous reports have been published on growth, survival, and tumor incidence, no overall compilation of organ weight data is available. Importantly, organ weight change is an endpoint used by regulatory agencies to develop toxicity reference values (TRVs) for use in human health risk assessments. Furthermore, physiologically based pharmacokinetic (PBPK) models, which utilize relative organ weights, are increasingly being used to develop TRVs. Therefore, all available absolute and relative organ weight data for untreated control B6C3F1 mice were collected from NCI/NTP studies in order to develop age-specific distributions. Results show that organ weights were collected more frequently in NCI/NTP studies at 2-wk (60 studies), 3-mo (147 studies), and 15-mo (40 studies) intervals than at other intervals, and more frequently from feeding and inhalation than drinking water studies. Liver, right kidney, lung, heart, thymus, and brain weights were most frequently collected. From the collected data, the mean and standard deviation for absolute and relative organ weights were calculated. Results show age-related increases in absolute liver, right kidney, lung, and heart weights and relatively stable brain and right testis weights. The results suggest a general variability trend in absolute organ weights of brain < right testis < right kidney < heart < liver < lung < spleen < thymus. This report describes the results of this effort.

  3. Stochastic Modulations of the Pace and Patterns of Ageing: Impacts on Quasi-Stochastic Distributions of Multiple Geriatric Pathologies

    PubMed Central

    Martin, George M.

    2011-01-01

    All phenotypes result from interactions between Nature, Nurture and Chance. The constitutional genome is clearly the dominant factor in explaining the striking differences in the pace and patterns of ageing among species. We are now in a position to reveal salient features underlying these differential modulations, which are likely to be dominated by regulatory domains. By contrast, I shall argue that stochastic events are the major players underlying the surprisingly large intra-specific variations in lifespan and healthspan. I shall review well established as well as more speculative categories of chance events – somatic mutations, protein synthesis error catastrophe and variegations of gene expression (epigenetic drift), with special emphasis upon the latter. I shall argue that stochastic drifts in variegated gene expression are the major contributors to intra-specific differences in the pace and patterns of ageing within members of the same species. They may be responsible for the quasi-stochastic distributions of major types of geriatric pathologies, including the “big three” of Alzheimer's disease, atherosclerosis and, via the induction of hyperplasis, cancer. They may be responsible for altered stoichiometries of heteromultimeric mitochondrial complexes, potentially leading to such disorders as sarcopenia, nonischemic cardiomyopathy and Parkinson's disease. PMID:21963385

  4. Distribution of blood pressure & correlates of hypertension in school children aged 5-14 years from North east India

    PubMed Central

    Borah, Prasanta Kr.; Devi, Utpala; Biswas, Dipankar; Kalita, Hem Ch.; Sharma, Meenakshi; Mahanta, Jagadish

    2015-01-01

    Background & objectives: Elevated blood pressure (BP) in the young predicts serious cardiovascular events in the adults. High prevalence of adult hypertension reported from Assam, North East (NE) India may be linked with elevated blood pressure in the childhood. The present study was an attempt to describe the distribution of BP and correlates of hypertension in children aged 5-14 yr. Methods: A total of 10,003 school children from 99 schools of Dibrugarh district, Assam, NE India, were surveyed by stratified random cluster method. Blood pressure, demographic and anthropometric information were recorded. Blood pressure was categorized in to normal, prehypertension, stage I and stage II hypertension. Results: Girls had significantly higher (104.2 ± 12.0 vs. 103.2 ± 11.6 mm Hg, P<0.001) mean systolic blood pressure (SBP) than boys. Both SBP and diastolic blood pressure (DBP) revealed significant correlation with age, height, weight and BMI in overall and in gender specific analysis. Hypertension was found in 7.6 per cent school children (Boys: 7.3%, Girls: 7.8%). In multivariable analysis older age (OR 3.3, 95% CI: 2.82-3.91), children from tea garden community (OR 1.3, 95% CI: 1.08-1.55) and other community (OR 1.4, 95% CI: 1.18-1.73) and overweight (OR 1.5, 95% CI: 1.1-2.1) were independently associated with hypertension. Interpretation & conclusions: Mean blood pressure in the young school children of 5-14 yr was high. A programme comprising screening, early detection and health promotion through school health programmes may help prevent future complications of hypertension. PMID:26458345

  5. Quantifying the distribution of nanodiamonds in pre-Younger Dryas to recent age deposits along Bull Creek, Oklahoma Panhandle, USA

    PubMed Central

    Bement, Leland C.; Madden, Andrew S.; Carter, Brian J.; Simms, Alexander R.; Swindle, Andrew L.; Alexander, Hanna M.; Fine, Scott; Benamara, Mourad

    2014-01-01

    High levels of nanodiamonds (nds) have been used to support the transformative hypothesis that an extraterrestrial (ET) event (comet explosion) triggered Younger Dryas changes in temperature, flora and fauna assemblages, and human adaptations [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104(41):16016–16021]. We evaluate this hypothesis by establishing the distribution of nds within the Bull Creek drainage of the Beaver River basin in the Oklahoma panhandle. The earlier report of an abundance spike of nds in the Bull Creek I Younger Dryas boundary soil is confirmed, although no pure cubic diamonds were identified. The lack of hexagonal nds suggests Bull Creek I is not near any impact site. Potential hexagonal nds at Bull Creek were found to be more consistent with graphene/graphane. An additional nd spike is found in deposits of late Holocene through the modern age, indicating nds are not unique to the Younger Dryas boundary. Nd distributions do not correlate with depositional environment, pedogenesis, climate perturbations, periods of surface stability, or cultural activity. PMID:24449875

  6. Age, composition, and areal distribution of the Pliocene Lawlor Tuff, and three younger Pliocene tuffs, California and Nevada

    USGS Publications Warehouse

    Sarna-Wojcicki, A. M.; Deino, A.L.; Fleck, R.J.; McLaughlin, R.J.; Wagner, D.; Wan, E.; Wahl, D.; Hillhouse, J.W.; Perkins, Michael

    2011-01-01

    The Lawlor Tuff is a widespread dacitic tephra layer produced by Plinian eruptions and ash flows derived from the Sonoma Volcanics, a volcanic area north of San Francisco Bay in the central Coast Ranges of California, USA. The younger, chemically similar Huichica tuff, the tuff of Napa, and the tuff of Monticello Road sequentially overlie the Lawlor Tuff, and were erupted from the same volcanic field. We obtain new laser-fusion and incremental-heating 40Ar/39Ar isochron and plateau ages of 4.834 ?? 0.011, 4.76 ?? 0.03, ???4.70 ?? 0.03, and 4.50 ?? 0.02 Ma (1 sigma), respectively, for these layers. The ages are concordant with their stratigraphic positions and are significantly older than those determined previously by the K-Ar method on the same tuffs in previous studies. Based on offsets of the ash-flow phase of the Lawlor Tuff by strands of the eastern San Andreas fault system within the northeastern San Francisco Bay area, total offset east of the Rodgers Creek-Healdsburg fault is estimated to be in the range of 36 to 56 km, with corresponding displacement rates between 8.4 and 11.6 mm/yr over the past ~4.83 Ma. We identify these tuffs by their chemical, petrographic, and magnetic characteristics over a large area in California and western Nevada, and at a number of new localities. They are thus unique chronostratigraphic markers that allow correlation of marine and terrestrial sedimentary and volcanic strata of early Pliocene age for their region of fallout. The tuff of Monticello Road is identified only near its eruptive source. ?? 2011 Geological Society of America.

  7. Regional Evaluation of Groundwater Age Distributions Using Lumped Parameter Models with Large, Sparse Datasets: Example from the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Jurgens, B. C.; Bohlke, J. K.; Voss, S.; Fram, M. S.; Esser, B.

    2015-12-01

    Tracer-based, lumped parameter models (LPMs) are an appealing way to estimate the distribution of age for groundwater because the cost of sampling wells is often less than building numerical groundwater flow models sufficiently complex to provide groundwater age distributions. In practice, however, tracer datasets are often incomplete because of anthropogenic or terrigenic contamination of tracers, or analytical limitations. While age interpretations using such datsets can have large uncertainties, it may still be possible to identify key parts of the age distribution if LPMs are carefully chosen to match hydrogeologic conceptualization and the degree of age mixing is reasonably estimated. We developed a systematic approach for evaluating groundwater age distributions using LPMs with a large but incomplete set of tracer data (3H, 3Hetrit, 14C, and CFCs) from 535 wells, mostly used for public supply, in the Central Valley, California, USA that were sampled by the USGS for the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment or the USGS National Water Quality Assessment Programs. In addition to mean ages, LPMs gave estimates of unsaturated zone travel times, recharge rates for pre- and post-development groundwater, the degree of age mixing in wells, proportion of young water (<60 yrs), and the depth of the boundary between post-development and predevelopment groundwater throughout the Central Valley. Age interpretations were evaluated by comparing past nitrate trends with LPM predicted trends, and whether the presence or absence of anthropogenic organic compounds was consistent with model results. This study illustrates a practical approach for assessing groundwater age information at a large scale to reveal important characteristics about the age structure of a major aquifer, and of the water supplies being derived from it.

  8. Relative controls of external and internal variability on time-variable transit time distributions, and the importance of StorAge Selection function approaches

    NASA Astrophysics Data System (ADS)

    Kim, M.; Pangle, L. A.; Cardoso, C.; Lora, M.; Meira, A.; Volkmann, T. H. M.; Wang, Y.; Harman, C. J.; Troch, P. A. A.

    2015-12-01

    Transit time distributions (TTDs) are an efficient way of characterizing complex transport dynamics of a hydrologic system. Time-invariant TTD has been studied extensively, but TTDs are time-varying under unsteady hydrologic systems due to both external variability (e.g., time-variability in fluxes), and internal variability (e.g., time-varying flow pathways). The use of "flow-weighted time" has been suggested to account for the effect of external variability on TTDs, but neglects the role of internal variability. Recently, to account both types of variability, StorAge Selection (SAS) function approaches were developed. One of these approaches enables the transport characteristics of a system - how the different aged water in the storage is sampled by the outflow - to be parameterized by time-variable probability distribution called the rank SAS (rSAS) function, and uses it directly to determine the time-variable TTDs resulting from a given timeseries of fluxes in and out of a system. Unlike TTDs, the form of the rSAS function varies only due to changes in flow pathways, but is not affected by the timing of fluxes alone. However, the relation between physical mechanisms and the time-varying rSAS functions are not well understood. In this study, relative effects of internal and external variability on the TTDs are examined using observations from a homogeneously packed 1 m3 sloping soil lysimeter. The observations suggest the importance of internal variability on TTDs, and reinforce the need to account for this variability using time-variable rSAS functions. Furthermore, the relative usefulness of two other formulations of SAS functions and the mortality rate (which plays a similar role to SAS functions in the McKendrick-von Foerster model of age-structured population dynamics) are also discussed. Finally, numerical modeling is used to explore the role of internal and external variability for hydrologic systems with diverse geomorphic and climate characteristics

  9. Aging, Alzheimer's, and APOE genotype influence the expression and neuronal distribution patterns of microtubule motor protein dynactin-P50

    PubMed Central

    Aboud, Orwa; Parcon, Paul A.; DeWall, K. Mark; Liu, Ling; Mrak, Robert E.; Griffin, W. Sue T.

    2015-01-01

    Reports from neural cell cultures and experimental animal studies provide evidence of age- and disease-related changes in retrograde transport of spent or misfolded proteins destined for degradation or recycling. However, few studies address these issues in human brain from those who either age without dementia and overt neuropathology, or succumb to Alzheimer's; especially as such propensity may be influenced by APOE genotype. We studied the expression and distribution of the dynein subunit dynactin-P50, the β amyloid precursor protein (βAPP), and hyperphosphorylated tau (P-tau) in tissues and tissue sections of brains from non-demented, neuropathology-free patients and from Alzheimer patients, with either APOE ε3,3 or APOE ε4,4. We found that advanced age in patients without dementia or neuropathological change was associated with coordinated increases in dynactin-P50 and βAPP in neurons in pyramidal layers of the hippocampus. In contrast, in Alzheimer's, βAPP and dynactin were significantly reduced. Furthermore, the dynactin-P50 and βAPP that was present was located primarily in dystrophic neurites in Aβ plaques. Tissues from Alzheimer patients with APOE ε3,3 had less P-tau, more βAPP, dynactin-P50, and synaptophysin than did tissues from Alzheimer patients carrying APOE ε4,4. It is logical to conclude, then, that as neurons age successfully, there is coordination between retrograde delivery and maintenance and repair, as well as between retrograde delivery and degradation and/or recycling of spent proteins. The buildup of proteins slated for repair, synaptic viability, transport, and re-cycling in neuron soma and dystrophic neurites suggest a loss of this coordination in Alzheimer neurons. Inheritance of APOE ε3,3 rather than APOE ε4,4, is associated with neuronal resilience, suggestive of better repair capabilities, more synapses, more efficient transport, and less hyperphosphorylation of tau. We conclude that even in disease the ε3 allele is

  10. Associations of disordered sleep with body fat distribution, physical activity and diet among overweight middle-aged men.

    PubMed

    Tan, Xiao; Alén, Markku; Cheng, Shu Mei; Mikkola, Tuija M; Tenhunen, Jarkko; Lyytikäinen, Arja; Wiklund, Petri; Cong, Fengyu; Saarinen, Antti; Tarkka, Ina; Partinen, Markku; Cheng, Sulin

    2015-08-01

    This cross-sectional study aimed to investigate whether body fat distribution, physical activity levels and dietary intakes are associated with insomnia and/or obstructive sleep apnea among overweight middle-aged men. Participants were 211 Finnish men aged 30-65 years. Among the 163 overweight or obese participants, 40 had insomnia only, 23 had obstructive sleep apnea only, 24 had comorbid insomnia and obstructive sleep apnea and 76 were without sleep disorder. The remaining 48 participants had normal weight without sleep disorder. Fat mass, levels of physical activity and diet were assessed by dual-energy X-ray densitometry, physical activity questionnaire and 3-day food diary, respectively. Among the overweight participants, we found that: (i) groups with sleep disorders had higher fat mass in trunk and android regions than the group without sleep disorder (P = 0.048-0.004); (ii) the insomnia-only group showed a lower level of leisure-time physical activity (436.9 versus 986.5 MET min week(-1) , P = 0.009) and higher intake of saturated fatty acids (14.8 versus 12.7 E%, P = 0.011) than the group without sleep disorder; and (iii) the comorbid group had a lower level of leisure-time physical activity (344.4 versus 986.5 MET min week(-1) , P = 0.007) and lower folate intake (118.9 versus 152.1 μg, P = 0.002) than the group without sleep disorder, which were independent of body mass index. The results suggest that central obesity is associated with insomnia and/or obstructive sleep apnea. In addition, low levels of leisure-time physical activity and poor dietary intakes are related to insomnia or comorbid insomnia and obstructive sleep apnea among overweight men.

  11. Effect of data length and bin numbers on distribution entropy (DistEn) measurement in analyzing healthy aging.

    PubMed

    Udhayakumar, Radhagayathri K; Karmakar, Chandan; Peng Li; Palaniswami, Marimuthu

    2015-01-01

    Complexity analysis of a given time series is executed using various measures of irregularity, the most commonly used being Approximate entropy (ApEn), Sample entropy (SampEn) and Fuzzy entropy (FuzzyEn). However, the dependence of these measures on the critical parameter of tolerance `r' leads to precarious results, owing to random selections of r. Attempts to eliminate the use of r in entropy calculations introduced a new measure of entropy namely distribution entropy (DistEn) based on the empirical probability distribution function (ePDF). DistEn completely avoids the use of a variance dependent parameter like r and replaces it by a parameter M, which corresponds to the number of bins used in the histogram to calculate it. When tested for synthetic data, M has been observed to produce a minimal effect on DistEn as compared to the effect of r on other entropy measures. Also, DistEn is said to be relatively stable with data length (N) variations, as far as synthetic data is concerned. However, these claims have not been analyzed for physiological data. Our study evaluates the effect of data length N and bin number M on the performance of DistEn using both synthetic and physiologic time series data. Synthetic logistic data of `Periodic' and `Chaotic' levels of complexity and 40 RR interval time series belonging to two groups of healthy aging population (young and elderly) have been used for the analysis. The stability and consistency of DistEn as a complexity measure as well as a classifier have been studied. Experiments prove that the parameters N and M are more influential in deciding the efficacy of DistEn performance in the case of physiologic data than synthetic data. Therefore, a generalized random selection of M for a given data length N may not always be an appropriate combination to yield good performance of DistEn for physiologic data.

  12. Self-similar aftershock rates

    NASA Astrophysics Data System (ADS)

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise—an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes—the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting.

  13. Self-similar aftershock rates.

    PubMed

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise-an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes-the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting.

  14. Biosimilar Insulins: How Similar is Similar?

    PubMed Central

    Heinemann, Lutz; Hompesch, Marcus

    2011-01-01

    Biosimilar insulins (BIs) are viewed as commercially attractive products by a number of companies. In order to obtain approval in the European Union or the United States, where there is not a single BI currently on the market, a manufacturer needs to demonstrate that a given BI has a safety and efficacy profile that is similar to that of the “original” insulin formulation that is already on the market. As trivial as this may appear at first glance, it is not trivial at all for a good number of reasons that will be discussed in this commentary. As with protein manufacturing, modifications in the structure of the insulin molecule can take place (which can have serious consequences for the biological effects induced), so a rigid and careful assessment is absolutely necessary. The example of Marvel's failed application with the European Medicines Agency provides insights into the regulatory and clinical challenges surrounding the matter of BI. Although a challenging BI approval process might be regarded as a hurdle to keep companies out of certain markets, it is fair to say that the potential safety and efficacy issues surrounding BI are substantial and relevant and do warrant a careful and evidence-driven approval process. PMID:21722590

  15. Quaternary sea level high-stand deposits of the southeast U.S. Atlantic Coastal Plain: Age, distribution, and implications.

    NASA Astrophysics Data System (ADS)

    Poirier, R. K.; Cronin, T. M.; Ghaleb, B.; Portell, R.; Hillaire-Marcel, C.; Wehmiller, J. F.; Thompson, W. G.; Oches, E. A.; Willard, D. A.; Katz, M. E.

    2015-12-01

    Emerged Quaternary paleo-shorelines and marine deposits provide a more direct way to reconstruct and analyze sea-level variability than methods using oxygen isotope analyses of deep ocean benthic foraminifera. New Uranium-series dates on fossil corals (primarily Astrangia spp. and Septastrea spp.) combined with previously published dates have allowed us to constrain the age, elevation, and geographical distribution of marine sediments deposited in the United States Atlantic Coastal Plain (ACP) from Virginia to Florida during periods of past high relative sea level (SL). We present new dates from deposits (VA/NC: Tabb/Norfolk, Nassawadox, & Omar Formations; SC: Wando, Socastee, & Canepatch Formations; FL: Anastasia, Ft. Thompson, & Bermont Formations) representing interglacial high-stands during Marine Isotope Stages (MIS) 5, 7, 9, and 11. In addition, we incorporate stratigraphic, marine micropaleontologic, and palynologic records with our SL chronology to reconstruct a more complete history of middle-to-late Pleistocene interglacial climates of the ACP. Ultimately, these results will test modeled sea-level fingerprint studies based on various melting scenarios of the Greenland and/or Antarctic ice sheets.

  16. Age-related shifts in the density and distribution of genetic marker water quality indicators in cow and calf feces.

    PubMed

    Shanks, Orin C; Kelty, Catherine A; Peed, Lindsay; Sivaganesan, Mano; Mooney, Thomas; Jenkins, Michael

    2014-03-01

    Calves make up about 16% of the current bovine population in the United States and can excrete high levels of human pathogens in their feces. We describe the density and distribution of genetic markers from 9 PCR- and real-time quantitative PCR-based assays, including CF128, CF193, CowM2, CowM3, GenBac3, Entero1, EC23S857, CampF2, and ttr-6, commonly used to help assess ambient surface water quality. Each assay was tested against a collection of 381 individual bovine fecal samples representing 31 mother and calf pairings collected over a 10-month time period from time of birth through weaning. Genetic markers reported to be associated with ruminant and/or bovine fecal pollution were virtually undetected in calves for up to 115 days from birth, suggesting that physiological changes in calf ruminant function impact host-associated genetic marker shedding. In addition, general fecal indicator markers for Bacteroidales, Escherichia coli, and Enterococcus spp. exhibited three separate trends across time, indicating that these bacteria respond differently to age-related physiological and dietary changes during calf development. The results of this study suggest that currently available PCR-based water quality indicator technologies can under- or overestimate fecal pollution originating from calves and identify a need for novel calf-associated source identification methods.

  17. Molecular similarity measures.

    PubMed

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2011-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of chemical space. Although all three concepts - molecular similarity, molecular representation, and chemical space - are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations that are of the same mathematical form into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another. An expanded account of the material on chemical spaces presented in the first edition of this book is also provided. It includes a discussion of the topography of activity landscapes and the role that activity cliffs in these landscapes play in structure-activity studies.

  18. Molecular similarity measures.

    PubMed

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2004-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of a chemistry space. Although all three concepts molecular similarity, molecular representation, and chemistry space are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations, that is, representations of the same mathematical form, into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another.

  19. The Gender Similarities Hypothesis

    ERIC Educational Resources Information Center

    Hyde, Janet Shibley

    2005-01-01

    The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses…

  20. Temporal development of total chlorine in the high-latitude stratosphere based on reference distributions of mean age derived from CO2 and SF6

    NASA Astrophysics Data System (ADS)

    Engel, Andreas; Strunk, Martin; Müller, Melanie; Haase, Hans-Peter; Poss, Christian; Levin, Ingeborg; Schmidt, Ulrich

    2002-06-01

    We present balloon-borne observations of CO2 and SF6 and derived vertical profiles of mean age for polar winter (inside vortex) and for midlatitude (nonwinter) conditions. For SF6-derived mean ages above 5 years a mesospheric SF6 sink may lead to an overestimation of mean age, while for younger mean ages (below 2 years) the seasonal cycle of CO2 may influence the mean age determination based on CO2. We suggest that SF6 be used as an age tracer in the lower part of the stratosphere (i.e., for low mean age), whereas CO2 will be the better age tracer for older air. The mean age distributions together with an estimate of the width of the age spectrum are used to estimate the stratospheric chlorine loading. On the basis of an emission scenario and the lifetimes of chlorine-containing compounds we estimate the future stratospheric chlorine loading. Inside the polar vortex, at an altitude of 20 km, we expect total chlorine to return to the values present in this region in 1980, when the ozone hole first appeared, around the year 2060. This estimate is based on the assumption that the general transport characteristics will not change over the period of the analysis and can thus be regarded as a best estimate based on stationary transport, the assumed set of lifetimes and emissions, and the mean age distribution derived from our measurements. As other factors influencing ozone may undergo temporal changes, this does not mean that ozone will necessarily recover at this time. While total chlorine is probably a good proxy for inorganic chlorine at altitudes above 20 km inside the polar vortex, the changing halocarbon mix may actually lead to an earlier return of inorganic chlorine to pre-ozone-hole values at lower altitudes.

  1. U-Th age distribution of coral fragments from multiple rubble ridges within the Frankland Islands, Great Barrier Reef: Implications for past storminess history

    NASA Astrophysics Data System (ADS)

    Liu, Entao; Zhao, Jian-xin; Feng, Yue-xing; Leonard, Nicole D.; Clark, Tara R.; Roff, George

    2016-07-01

    Prograded coral rubble ridges have been widely used as archives for reconstructing long-term storm or storminess history. Chronologies of ridge systems in previous studies are often based on a limited number of low-resolution radiocarbon or optically-stimulated luminescence (OSL) ages per ridge (usually only one age per ridge), which carry intrinsic age uncertainties and make interpretation of storm histories problematic. To test the fidelity of storm ridges as palaeo-storm archives, we used high-precision U-Th dating to examine whether different samples from a single ridge are temporally constrained. We surveyed three transects of ridge systems from two continental islands (Normanby Island and High Island) within the Frankland Islands, Great Barrier Reef (GBR), and obtained 96 U-Th dates from coral rubble samples collected from within and between different ridges. Our results revealed significant differences in age ranges between the two islands. The steeper and more defined rubble ridges present on Normanby Island revealed that the majority of U-Th ages (over 60%) from a single ridge clustered within a narrow age range (∼100 years). By contrast, the lower and less defined ridges on High Island, which were more likely formed during both storm and non-storm high-energy events, revealed significant scatter in age distribution (>>200 years) with no notable clustering. The narrower age ranges obtained from the steeper and more defined rubble ridges suggest that previous approaches of using either limited samples from a single ridge or low-precision dating methods to establish chronologies are generally valid at centennial to millennial timescales, although caution must be taken to use such approaches for storm history reconstruction on shorter timescales (e.g. decadal). The correlation between U-Th mortality ages of coral rubble and historical stormy periods highlights the possibility of using coral rubble age distribution from rubble ridges to reconstruct the long

  2. Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in east- and south-central Alaska

    USGS Publications Warehouse

    Dusel-Bacon, Cynthia; Csejtey, Bela; Foster, Helen L.; Doyle, Elizabeth O.; Nokleberg, Warren J.; Plafker, George

    1993-01-01

    Most of the exposed bedrock in east- and south-central Alaska has been regionally metamorphosed and deformed during Mesozoic and early Cenozoic time. All the regionally metamorphosed rocks are assigned to metamorphic-facies units on the basis of their temperature and pressure conditions and metamorphic age. North of the McKinley and Denali faults, the crystalline rocks of the Yukon- Tanana upland and central Alaska Range compose a sequence of dynamothermally metamorphosed Paleozoic and older(?) metasedimentary rocks and metamorphosed products of a Devonian and Mississippian continental-margin magmatic arc. This sequence was extensively intruded by postmetamorphic mid-Cretaceous and younger granitoids. Many metamorphic-unit boundaries in the Yukon-Tanana upland are low-angle faults that juxtapose units of differing metamorphic grade, which indicates that metamorphism predated final emplacement of the fault-bounded units. In some places, the relation of metamorphic grade across a fault is best explained by contractional faulting; in other places, it is suggestive of extensional faulting.Near the United States-Canadian border in the central Yukon- Tanana upland, metamorphism, plutonism, and thrusting occurred during a latest Triassic and Early Jurassic event that presumably resulted from the accretion of a terrane that had affinities to the Stikinia terrane onto the continental margin of North America. Elsewhere in the Yukon-Tanana upland, metamorphic rocks give predominantly late Early Cretaceous isotopic ages. These ages are interpreted to date either the timing of a subsequent Early Cretaceous episode of crustal thickening and metamorphism or, assuming that these other areas were also originally heated during the latest Triassic to Early Jurassic and remained buried, the timing of their uplift and cooling. This uplift and cooling may have resulted from extension.South of the McKinley and Denali faults and north of the Border Ranges fault system, medium

  3. Nutrition as a part of healthy aging and reducing cardiovascular risk: improving functionality in later life using quality protein, with optimized timing and distribution.

    PubMed

    Dawson, Beryl M; Axford, Samantha

    2014-09-01

    Aging is associated with many physiological changes, which may in time lead to numerous pathophysiological outcomes, including adverse vascular events. For example, senescence of the immune system and cellular senescence both contribute to rising inflammation with age, potentially induced by the overall burden of comorbid illness, adipose tissue mass, diet, socioeconomic status, and physical activity. In turn, this chronic inflammation decreases physical and cognitive performance, and promotes sarcopenia and the syndrome of frailty. These events and others decrease the functionality of life as we age and include an increased risk of thrombosis and adverse cardiovascular outcomes. In this review, we aim to overview the aging process primarily as related to functional impairment, and provide evidence for the role of protein, and specifically differential quality protein, in particular whey protein, and timing and distribution of intake, to help reduce some of the morbid effects of aging, including reducing obesity, improving glycemic control, and improving vascular function.

  4. Time-slice maps showing age, distribution, and style of deformation in Alaska north of 60° N.

    USGS Publications Warehouse

    Moore, Thomas E.; Box, Stephen E.

    2016-08-29

    The structural architecture of Alaska is the product of a complex history of tectonism that occurred along the Cordilleran and Arctic margins of North America through interactions with ancient and modern ocean plates and with continental elements derived from Laurentia, Siberia, and Baltica. To unravel the tectonic history of Alaska, we constructed maps showing the age, distribution, structural style, and kinematics of contractional and penetrative extensional deformation in Alaska north of latitude 60° N. at a scale of 1:5,000,000. These maps use the Geologic Map of the Arctic (Harrison and others, 2011) as a base map and follow the guidelines in the Tectonic Map of the Arctic project (Petrov and others, 2013) for construction, including use of the International Commission on Stratigraphy time scale (Cohen and others, 2013) divided into 20 time intervals. We find evidence for deformation in 14 of the 20 time intervals and present maps showing the known or probable extent of deformation for each time interval. Maps and descriptions of deformational style, age constraints, kinematics, and information sources for each deformational episode are discussed in the text and are reported in tabular form. This report also contains maps showing the lithologies and structural geology of Alaska, a terrane map, and the distribution of tectonically important units including post-tectonic sedimentary basins, accretionary complexes, ophiolites, metamorphic rocks.These new maps show that most deformational belts in Alaska are relatively young features, having developed during the late Mesozoic and Cenozoic. The oldest episode of deformation recognized anywhere in Alaska is found in the basement of the Farewell terrane (~1.75 Ga). Paleozoic and early Mesozoic deformational events, including Devonian deformation in the Arctic Alaska terrane, Pennsylvanian deformation in the Alexander terrane, Permian deformation in the Yukon Composite (Klondike orogeny) and Farewell terranes (Browns

  5. Red Blood Cell Distribution Width and the Platelet Count in Iron-deficient Children Aged 0.5-3 Years.

    PubMed

    Akkermans, M D; Uijterschout, L; Vloemans, J; Teunisse, P P; Hudig, F; Bubbers, S; Verbruggen, S; Veldhorst, M; de Leeuw, T G; van Goudoever, J B; Brus, F

    2015-01-01

    Early detection of iron deficiency (ID) and iron deficiency anemia (IDA) in young children is important to prevent impaired neurodevelopment. Unfortunately, many biomarkers of ID are influenced by infection, thus limiting their usefulness. The aim of this study was to investigate the value of red blood cell distribution width (RDW) and the platelet count for detecting ID(A) among otherwise healthy children. A multicenter prospective observational study was conducted in the Netherlands to investigate the prevalence of ID(A) in 400 healthy children aged 0.5-3 years. ID was defined as serum ferritin (SF) <12 μg/L in the absence of infection (C-reactive protein [CRP] <5 mg/L) and IDA as hemoglobin <110 g/L combined with ID. RDW (%) and the platelet count were determined in the complete blood cell count. RDW was inversely correlated with SF and not associated with CRP. Calculated cutoff values for RDW to detect ID and IDA gave a relatively low sensitivity (53.1% and 57.1%, respectively) and specificity (64.7% and 69.9%, respectively). Anemic children with a RDW >14.3% had a 2.7 higher odds (95% confidence interval [CI]: 1.2-6.3) to be iron deficient, compared with anemic children with a RDW <14.3%. The platelet count showed a large range in both ID and non-ID children. In conclusion, RDW can be helpful for identifying ID as the cause of anemia in 0.5- to 3-year-old children, but not as primary biomarker of ID(A). RDW values are not influenced by the presence of infection. There appears to be no role for the platelet count in diagnosing ID(A) in this group of children.

  6. Additive Similarity Trees

    ERIC Educational Resources Information Center

    Sattath, Shmuel; Tversky, Amos

    1977-01-01

    Tree representations of similarity data are investigated. Hierarchical clustering is critically examined, and a more general procedure, called the additive tree, is presented. The additive tree representation is then compared to multidimensional scaling. (Author/JKS)

  7. The Relationship of Loss, Mean Age of Air and the Distribution of CFC's to Stratospheric Circulation and Implications for Atmospheric Lifetimes

    NASA Technical Reports Server (NTRS)

    Douglas, A. R.; Stolarski, R. S.; Schoeberl, M. R.; Jackman, C. H.; Gupta, M. L.; Newman, P. A.; Nielsen, J. E.; Fleming, E. L.

    2008-01-01

    Model-derived estimates of the annually integrated destruction and lifetime for various ozone depleting substances (ODSs) depend on the simulated stratospheric transport and mixing in the global model used to produce the estimate. Observations in the middle and high latitude lower stratosphere show that the mean age of an air parcel (i.e., the time since its stratospheric entry) is related to the fractional release for the ODs (i.e., the amount of the ODS that has been destroyed relative to the amount at the time of stratospheric entry). We use back trajectory calculations to produce an age spectrum, and explain the relationship between the mean age and the fractional release by showing that older elements in the age spectrum have experienced higher altitudes and greater ODs destruction than younger elements. In our study, models with faster circulations produce distributions for the age-of-air that are 'young' compared to a distribution derived from observations. These models also fail to reproduce the observed relationship between the mean age of air and the fractional release. Models with slower circulations produce both realistic distributions for mean age and a realistic relationship between mean age and fractional release. These models also produce a CFCl3 lifetime of approximately 56 years, longer than the 45 year lifetime used to project future mixing ratios. We find that the use of flux boundary conditions in assessment models would have several advantages, including consistency between ODS evolution and simulated loss even if the simulated residual circulation changes due to climate change.

  8. Enabling data science in the Gaia mission archive: The present-day mass function and age distribution

    NASA Astrophysics Data System (ADS)

    Tapiador, D.; Berihuete, A.; Sarro, L. M.; Julbe, F.; Huedo, E.

    2017-04-01

    Recent advances in large scale computing architectures enable new opportunities to extract value out of the vast amounts of data being currently generated. However, their successful adoption is not straightforward in areas like science, as there are still some barriers that need to be overcome. Those comprise (i) the existence of legacy code that needs to be ported, (ii) the lack of high-level and use case specific frameworks that facilitate a smoother transition, or (iii) the scarcity of profiles with the balanced skill sets between the technological and scientific domains. The European Space Agency's Gaia mission will create the largest and most precise three dimensional chart of our galaxy (the Milky Way), providing unprecedented position, parallax and proper motion measurements for about one billion stars. The successful exploitation of this data archive will depend on the ability to offer the proper infrastructure upon which scientists will be able to do exploration and modelling with this huge data set. In this paper, we present and contextualize these challenges by building two probabilistic models using Hierarchical Bayesian Modelling. These models represent a key challenge in astronomy and are of paramount importance for the Gaia mission itself. Moreover, we approach the implementation by leveraging a generic distributed processing engine through an existing software package for Markov chain Monte Carlo sampling. The two computationally intensive models are then validated with simulated data in different scenarios under specific restrictions, and their performance is assessed to prove their scalability. We argue that this approach will not only serve for the models in hand but also for exemplifying how to address similar problems in science, which may need to both scale to bigger data sets and reuse existing software as much as possible. This will lead to shorter time to science in massive data archives.

  9. Age, Distribution, and Style of Deformation in Alaska North of 60°N: Implications for Assembly of Alaska

    NASA Astrophysics Data System (ADS)

    Moore, T. E.; Box, S. E.

    2015-12-01

    The structural architecture of Alaska is the product of a complex history of deformation along both the Cordilleran and Arctic margins of North America through interactions with ocean plates and with continental elements of Laurentia, Siberia, and Baltica. We use geological constraints to assign areal deformation to 14 time intervals and map their distributions in Alaska. Alaska can be divided into three domains with differing histories of deformation. The northern domain experienced the Early Cretaceous Brookian orogeny, an oceanic arc-continent collisional orogeny, followed by a mid-Cretaceous extensional overprint. Opening of the oceanic Canada Basin rifted the orogen from the Canadian Arctic margin, producing the bent trends of the orogen. The second domain constitutes the Phanerozoic Peninsular-Wrangellia-Alexander arc terrane and its paired Mesozoic accretionary prisms. Its structural history is unrelated to domains to the north until a shared history of Late Cretaceous deformation. The third domain, situated between the first two domains and roughly bounded by the Cenozoic dextral Denali and Tintina faults, includes the Yukon Composite terrane (Laurentian origin) and the large Farewell (Baltica origin) terrane. These terranes are not linked until Late Cretaceous sedimentary overlap, but we have not identified a shared deformation between these two terranes that might mark their juxtaposition by collisional processes. Similar early Late Cretaceous sedimentary linkages stitch the northern and central domains. Late Late Cretaceous folding and thrusting across much of Alaska south of the Brooks Range correlates temporally with the collision of the southern domain with the remainder of Alaska. Early Cenozoic shortening is mild across much of the state but is significant in the Brooks Range, and correlates in time with dextral faulting, ridge subduction, and rotation of western Alaska. Late Cenozoic shortening is significant in southern Alaska inboard of the

  10. Estimating Age Distributions of Base Flow in Watersheds Underlain by Single and Dual Porosity Formations Using Groundwater Transport Simulation and Weighted Weibull Functions

    NASA Astrophysics Data System (ADS)

    Sanford, W. E.

    2015-12-01

    Age distributions of base flow to streams are important to estimate for predicting the timing of water-quality responses to changes in distributed inputs of nutrients or pollutants at the land surface. Simple models of shallow aquifers will predict exponential age distributions, but more realistic 3-D stream-aquifer geometries will cause deviations from an exponential curve. In addition, in fractured rock terrains the dual nature of the effective and total porosity of the system complicates the age distribution further. In this study shallow groundwater flow and advective transport were simulated in two regions in the Eastern United States—the Delmarva Peninsula and the upper Potomac River basin. The former is underlain by layers of unconsolidated sediment, while the latter consists of folded and fractured sedimentary rocks. Transport of groundwater to streams was simulated using the USGS code MODPATH within 175 and 275 watersheds, respectively. For the fractured rock terrain, calculations were also performed along flow pathlines to account for exchange between mobile and immobile flow zones. Porosities at both sites were calibrated using environmental tracer data (3H, 3He, CFCs and SF6) in wells and springs, and with a 30-year tritium record from the Potomac River. Carbonate and siliciclastic rocks were calibrated to have mobile porosity values of one and six percent, and immobile porosity values of 18 and 12 percent, respectively. The age distributions were fitted to Weibull functions. Whereas an exponential function has one parameter that controls the median age of the distribution, a Weibull function has an extra parameter that controls the slope of the curve. A weighted Weibull function was also developed that potentially allows for four parameters, two that control the median age and two that control the slope, one of each weighted toward early or late arrival times. For both systems the two-parameter Weibull function nearly always produced a substantially

  11. The Qualitative Similarity Hypothesis

    ERIC Educational Resources Information Center

    Paul, Peter V.; Lee, Chongmin

    2010-01-01

    Evidence is presented for the qualitative similarity hypothesis (QSH) with respect to children and adolescents who are d/Deaf or hard of hearing. The primary focus is on the development of English language and literacy skills, and some information is provided on the acquisition of English as a second language. The QSH is briefly discussed within…

  12. Diel distribution of age-0 largemouth bass, Micropterus salmoides, in B. E. Jordan Lake, North Carolina (USA) and its relation to cover

    USGS Publications Warehouse

    Irwin, E.R.; Noble, R.L.

    2000-01-01

    We used prepositioned area electrofishers (PAEs, 10X1.5 m) to assess diel differences in distribution of age-0 largemouth bass, Micropterus salmoides, in August 1992-1993 in a paired sampling design. PAEs were placed parallel to shore in an embayment of an unvegetated reservoir (B. E. Jordan Lake, North Carolina, USA). The catch per unit effort (CPUE=fish/PAE) was significantly higher at night than during the day in both years, indicating that age-0 largemouth bass exhibit nocturnal inshore movements. Age-0 largemouth bass captured inshore during day were smaller than those captured at night, indicating that movement patterns may change ontogenetically. Inshore-offshore movements of age-0 largemouth bass were significantly reduced in the presence of cover, suggesting that diel movements were influenced by specific habitat components. Diel movements likely were related to foraging, resting and predator avoidance behavior and could affect population dynamics and introduce bias in assessment programs.

  13. Temporal-spatial distribution of archaeological sites in the Nihewan-Huliu Basin during the Paleolithic-Neolithic and Iron Age in northern China

    NASA Astrophysics Data System (ADS)

    Zhang, J. X.; Wang, X. Y.; Yang, R. X.; Li, X. Z.; Zhang, W.

    2016-11-01

    The Nihewan-Huliu Basin is one of the great regions of human evolution, located in geographical transition zone. This study reveals the temporal-spatial distribution of archaeological sites based on the DEM (Digital Elevation Model) data, and analyses the changes for four periods (Paleolithic-Neolithic transition, Neolithic Age, Bronze Age and Iron Age). These sites expanded from the Sanggan River to the Huliu River and from the central and lower Huliu River to its upper reaches. The population and cultural development in the Nihewan Basin gradually lagged behind the Huliu River Baisin after the Paleolithic-Neolithic transition Age, because of the environmental impacts. The results may aid the understanding and study of the cultural heritage and civilization evolution in northern China.

  14. [The incidence, age dependence and sex distribution of the calcaneal spur. An analysis of its x-ray morphology in 1027 patients of the central European population].

    PubMed

    Riepert, T; Drechsler, T; Urban, R; Schild, H; Mattern, R

    1995-06-01

    In 1027 lateral radiograms of the ankle in a Caucasian population, 161 plantar and/or dorsal calcaneal spurs (15.7%) were diagnosed. Plantar spurs were more common than dorsal spurs (11.2 and 9.3% respectively). Prevalence of both spurs increases considerably with the rising age. Dorsal spurs appear slightly earlier than plantar spurs. The spur frequencies are similar in left and right feet. The plantar spurs were significantly (p < 0.0001) more common in women than in men in general, while dorsal spurs were more frequent in men than in women up to the age of 70. The previously reported higher frequencies of plantar and dorsal calcaneal spurs in women than in men are probably a result of a disproportionally higher number of women in higher age in the groups studied. In forensic medicine, calcaneal spurs provide evidence for identity and age of unknown corpses, and to certain extend their profession, physical activities and constitution during life.

  15. Quantile Regression Analysis of the Distributional Effects of Air Pollution on Blood Pressure, Heart Rate Variability, Blood Lipids, and Biomarkers of Inflammation in Elderly American Men: The Normative Aging Study

    PubMed Central

    Bind, Marie-Abele; Peters, Annette; Koutrakis, Petros; Coull, Brent; Vokonas, Pantel; Schwartz, Joel

    2016-01-01

    Background: Previous studies have observed associations between air pollution and heart disease. Susceptibility to air pollution effects has been examined mostly with a test of effect modification, but little evidence is available whether air pollution distorts cardiovascular risk factor distribution. Objectives: This paper aims to examine distributional and heterogeneous effects of air pollution on known cardiovascular biomarkers. Methods: A total of 1,112 men from the Normative Aging Study and residents of the greater Boston, Massachusetts, area with mean age of 69 years at baseline were included in this study during the period 1995–2013. We used quantile regression and random slope models to investigate distributional effects and heterogeneity in the traffic-related responses on blood pressure, heart rate variability, repolarization, lipids, and inflammation. We considered 28-day averaged exposure to particle number, PM2.5 black carbon, and PM2.5 mass concentrations (measured at a single monitor near the site of the study visits). Results: We observed some evidence suggesting distributional effects of traffic-related pollutants on systolic blood pressure, heart rate variability, corrected QT interval, low density lipoprotein (LDL) cholesterol, triglyceride, and intercellular adhesion molecule-1 (ICAM-1). For example, among participants with LDL cholesterol below 80 mg/dL, an interquartile range increase in PM2.5 black carbon exposure was associated with a 7-mg/dL (95% CI: 5, 10) increase in LDL cholesterol, while among subjects with LDL cholesterol levels close to 160 mg/dL, the same exposure was related to a 16-mg/dL (95% CI: 13, 20) increase in LDL cholesterol. We observed similar heterogeneous associations across low versus high percentiles of the LDL distribution for PM2.5 mass and particle number. Conclusions: These results suggest that air pollution distorts the distribution of cardiovascular risk factors, and that, for several outcomes, effects may be

  16. Comparison of hydrological similarity measures

    NASA Astrophysics Data System (ADS)

    Rianna, Maura; Ridolfi, Elena; Manciola, Piergiorgio; Napolitano, Francesco; Russo, Fabio

    2016-04-01

    The use of a traditional at site approach for the statistical characterization and simulation of spatio-temporal precipitation fields has a major recognized drawback. Indeed, the weakness of the methodology is related to the estimation of rare events and it involves the uncertainty of the at-site sample statistical inference, because of the limited length of records. In order to overcome the lack of at-site observations, regional frequency approach uses the idea of substituting space for time to estimate design floods. The conventional regional frequency analysis estimates quantile values at a specific site from multi-site analysis. The main idea is that homogeneous sites, once pooled together, have similar probability distribution curves of extremes, except for a scaling factor. The method for pooling groups of sites can be based on geographical or climatological considerations. In this work the region of influence (ROI) pooling method is compared with an entropy-based one. The ROI is a flexible pooling group approach which defines for each site its own "region" formed by a unique set of similar stations. The similarity is found through the Euclidean distance metric in the attribute space. Here an alternative approach based on entropy is introduced to cluster homogeneous sites. The core idea is that homogeneous sites share a redundant (i.e. similar) amount of information. Homogeneous sites are pooled through a hierarchical selection based on the mutual information index (i.e. a measure of redundancy). The method is tested on precipitation data in Central Italy area.

  17. Interneurons targeting similar layers receive synaptic inputs with similar kinetics.

    PubMed

    Cossart, Rosa; Petanjek, Zdravko; Dumitriu, Dani; Hirsch, June C; Ben-Ari, Yehezkel; Esclapez, Monique; Bernard, Christophe

    2006-01-01

    GABAergic interneurons play diverse and important roles in controlling neuronal network dynamics. They are characterized by an extreme heterogeneity morphologically, neurochemically, and physiologically, but a functionally relevant classification is still lacking. Present taxonomy is essentially based on their postsynaptic targets, but a physiological counterpart to this classification has not yet been determined. Using a quantitative analysis based on multidimensional clustering of morphological and physiological variables, we now demonstrate a strong correlation between the kinetics of glutamate and GABA miniature synaptic currents received by CA1 hippocampal interneurons and the laminar distribution of their axons: neurons that project to the same layer(s) receive synaptic inputs with similar kinetics distributions. In contrast, the kinetics distributions of GABAergic and glutamatergic synaptic events received by a given interneuron do not depend upon its somatic location or dendritic arborization. Although the mechanisms responsible for this unexpected observation are still unclear, our results suggest that interneurons may be programmed to receive synaptic currents with specific temporal dynamics depending on their targets and the local networks in which they operate.

  18. The cosmic-ray path length (age) distribution in the Galaxy - Experimental limits on the deviation from an exponential

    NASA Technical Reports Server (NTRS)

    Webber, W. R.

    1993-01-01

    A systematic examination is presented of the observational effects that can provide information on the departure of the cosmic-ray path length distribution (PLD) for propagation in the Galaxy from a simple exponential distribution. The possible physical causes for this departure are examined in order to set realistic limits on how well a simple exponential PLD actually describes the distribution of sources and propagation of cosmic rays in the galaxy. From the findings, it is argued that the cosmic ray source distribution must be quite uniform, probably on a scale of about 50 pc or less near the sun. Extending this uniformity to the Galaxy as a whole would imply more than 100,000 active sources. The cosmic-ray propagation can be described quite well by a leaky box model which is equivalent to observing the particles through a dense fog.

  19. Aging Water Infrastructure Program at U.S. EPA: Rehabilitation of Water Distribution and Wastewater Collection Systems

    EPA Science Inventory

    Several EPA projects are currently underway to encourage technology development and dissemination in key aspects of the condition assessment and rehabilitation of water and wastewater systems. The progress on one of these projects, "Rehabilitation of Water Distribution and Waste...

  20. Ages and stratigraphy of lunar mare basalts in Mare Frigoris and other nearside maria based on crater size-frequency distribution measurements

    NASA Astrophysics Data System (ADS)

    Hiesinger, H.; Head, J. W.; Wolf, U.; Jaumann, R.; Neukum, G.

    2010-03-01

    , basalts in the northeast are 3.60-3.79 Gyr old. These results confirm and extend the general distribution of ages of mare basalt volcanism and further underline the predominance of older mare basalt ages in the eastern and southern nearside and in patches of mare peripheral to the larger maria, in contrast to the younger basalt ages on the western nearside (Oceanus Procellarum).

  1. Similar enzymes, different structures

    PubMed Central

    Tarasev, Michael; Kaddis, Catherine S.; Yin, Sheng; Loo, Joseph A.; Burgner, John; Ballou, David P.

    2007-01-01

    Phthalate dioxygenase (PDO) is a member of a class of bacterial oxygenases that contain both Rieske [2Fe-2S] and Fe(II) mononuclear centers. Recent crystal structures of several Rieske dioxygenases showed that they exist as α3β3 multimers with subunits arranged head-to-tail in α and β stacked planar consists of only α-subunits, remains to be solved. Although similar to other Rieske dioxygenases in many aspects, PDO was shown to differ in the mechanism of catalysis. Gel filtration and analytical centrifugation experiments, supplemented with mass spectrometric analysis (both ESI-MS and ESI-GEMMA), in this work showed a hexameric arrangement of subunits in the PDO multimer. Our proposed model for the subunit arrangement in PDO postulates two α3 planar rings one on top the other, similar to the α3β3 arrangement in other Rieske dioxygenases. Unlike other Rieske dioxygenases, this arrangement brings two Rieske and two mononuclear centers, all on separate subunits, into proximity, allowing their cooperation for catalysis. Potential reasons necessitating this unusual structural arrangement are discussed. PMID:17764654

  2. Using groundwater age distributions to understand changes in methyl tert-butyl ether (MtBE) concentrations in ambient groundwater, northeastern United States

    USGS Publications Warehouse

    Lindsey, Bruce; Ayotte, Joseph; Jurgens, Bryant; DeSimone, Leslie

    2017-01-01

    Temporal changes in methyl tert-butyl ether (MtBE) concentrations in groundwater were evaluated in the northeastern United States, an area of the nation with widespread low-level detections of MtBE based on a national survey of wells selected to represent ambient conditions. MtBE use in the U.S. peaked in 1999 and was largely discontinued by 2007. Six well networks, each representing specific areas and well types (monitoring or supply wells), were each sampled at 10 year intervals between 1996 and 2012. Concentrations were decreasing or unchanged in most wells as of 2012, with the exception of a small number of wells where concentrations continue to increase. Statistically significant increasing concentrations were found in one network sampled for the second time shortly after the peak of MtBE use, and decreasing concentrations were found in two networks sampled for the second time about 10 years after the peak of MtBE use. Simulated concentrations from convolutions of estimates for concentrations of MtBE in recharge water with age distributions from environmental tracer data correctly predicted the direction of MtBE concentration changes in about 65 percent of individual wells. The best matches between simulated and observed concentrations were found when simulating recharge concentrations that followed the pattern of national MtBE use. Some observations were matched better when recharge was modeled as a plume moving past the well from a spill at one point in time. Modeling and sample results showed that wells with young median ages and narrow age distributions responded more quickly to changes in the contaminant source than wells with older median ages and broad age distributions. Well depth and aquifer type affect these responses. Regardless of the timing of decontamination, all of these aquifers show high susceptibility for contamination by a highly soluble, persistent constituent.

  3. Residence times and age distributions of spring waters at the Semmering catchment area, Eastern Austria, as inferred from tritium, CFCs and stable isotopes.

    PubMed

    Han, Liangfeng; Hacker, Peter; Gröning, Manfred

    2007-03-01

    The groundwater system in the mountainous area of Semmering, Austria, was studied by environmental tracers in several karst springs. The tracers used included stable isotopes ((18)O, (2)H), tritium ((3)H) and chlorofluorocarbons (CFCs). The tracers provided valuable information in regard to (1) the mean altitude of the spring catchment areas; (2) the residence time and age distribution of the spring waters; and (3) the interconnection of the springs to a sinkhole. The combination of the stable isotopic data and the topography/geology provided the estimates of the mean altitudes of the catchment areas. Based on the stable isotopic data the recharge temperature of the spring waters was estimated. The smoothing of precipitation's isotopic signal in spring discharge provided information on the minimum transit time of the spring waters. Due to short observation time, (3)H data alone cannot be used for describing the mean residence time of the karst waters. CFCs, though useful in recognizing the co-existence of young (post-1993) water with old (CFC-free) water, could not be used to resolve age distribution models. It is shown in this article, however, that the combined use of tritium and CFCs can provide a better assessment of models to account for different groundwater age distributions. In Appendix A, a simplified method for collecting groundwater samples for the analysis of CFCs is described. The method provides a real facilitation for fieldwork. Test data are given for this sampling method in regard to potential contamination by atmospheric CFCs.

  4. Modelling of the Electric Field Distribution in Deep Transcranial Magnetic Stimulation in the Adolescence, in the Adulthood, and in the Old Age.

    PubMed

    Fiocchi, Serena; Longhi, Michela; Ravazzani, Paolo; Roth, Yiftach; Zangen, Abraham; Parazzini, Marta

    2016-01-01

    In the last few years, deep transcranial magnetic stimulation (dTMS) has been used for the treatment of depressive disorders, which affect a broad category of people, from adolescents to aging people. To facilitate its clinical application, particular shapes of coils, including the so-called Hesed coils, were designed. Given their increasing demand and the lack of studies which accurately characterize their use, this paper aims to provide a picture of the distribution of the induced electric field in four realistic human models of different ages and gender. In detail, the electric field distributions were calculated by using numerical techniques in the brain structures potentially involved in the progression of the disease and were quantified in terms of both amplitude levels and focusing power of the distribution. The results highlight how the chosen Hesed coil (H7 coil) is able to induce the maxima levels of E mainly in the prefrontal cortex, particularly for the younger model. Moreover, growing levels of induced electric fields with age were found by going in deep in the brain, as well as a major capability to penetrate in the deepest brain structures with an electric field higher than 50%, 70%, and 90% of the peak found in the cortex.

  5. Modelling of the Electric Field Distribution in Deep Transcranial Magnetic Stimulation in the Adolescence, in the Adulthood, and in the Old Age

    PubMed Central

    Fiocchi, Serena; Longhi, Michela; Ravazzani, Paolo; Roth, Yiftach; Zangen, Abraham; Parazzini, Marta

    2016-01-01

    In the last few years, deep transcranial magnetic stimulation (dTMS) has been used for the treatment of depressive disorders, which affect a broad category of people, from adolescents to aging people. To facilitate its clinical application, particular shapes of coils, including the so-called Hesed coils, were designed. Given their increasing demand and the lack of studies which accurately characterize their use, this paper aims to provide a picture of the distribution of the induced electric field in four realistic human models of different ages and gender. In detail, the electric field distributions were calculated by using numerical techniques in the brain structures potentially involved in the progression of the disease and were quantified in terms of both amplitude levels and focusing power of the distribution. The results highlight how the chosen Hesed coil (H7 coil) is able to induce the maxima levels of E mainly in the prefrontal cortex, particularly for the younger model. Moreover, growing levels of induced electric fields with age were found by going in deep in the brain, as well as a major capability to penetrate in the deepest brain structures with an electric field higher than 50%, 70%, and 90% of the peak found in the cortex. PMID:27069502

  6. Similarity transformed semiclassical dynamics

    NASA Astrophysics Data System (ADS)

    Van Voorhis, Troy; Heller, Eric J.

    2003-12-01

    In this article, we employ a recently discovered criterion for selecting important contributions to the semiclassical coherent state propagator [T. Van Voorhis and E. J. Heller, Phys. Rev. A 66, 050501 (2002)] to study the dynamics of many dimensional problems. We show that the dynamics are governed by a similarity transformed version of the standard classical Hamiltonian. In this light, our selection criterion amounts to using trajectories generated with the untransformed Hamiltonian as approximate initial conditions for the transformed boundary value problem. We apply the new selection scheme to some multidimensional Henon-Heiles problems and compare our results to those obtained with the more sophisticated Herman-Kluk approach. We find that the present technique gives near-quantitative agreement with the the standard results, but that the amount of computational effort is less than Herman-Kluk requires even when sophisticated integral smoothing techniques are employed in the latter.

  7. Statistical self-similarity of hotspot seamount volumes modeled as self-similar criticality

    USGS Publications Warehouse

    Tebbens, S.F.; Burroughs, S.M.; Barton, C.C.; Naar, D.F.

    2001-01-01

    The processes responsible for hotspot seamount formation are complex, yet the cumulative frequency-volume distribution of hotspot seamounts in the Easter Island/Salas y Gomez Chain (ESC) is found to be well-described by an upper-truncated power law. We develop a model for hotspot seamount formation where uniform energy input produces events initiated on a self-similar distribution of critical cells. We call this model Self-Similar Criticality (SSC). By allowing the spatial distribution of magma migration to be self-similar, the SSC model recreates the observed ESC seamount volume distribution. The SSC model may have broad applicability to other natural systems.

  8. HIV Infection Is Associated with Increased Fatty Infiltration of the Thigh Muscle with Aging Independent of Fat Distribution

    PubMed Central

    Sellmeyer, Deborah E.; Haberlen, Sabina A.; Margolick, Joseph; Jacobson, Lisa P.; Palella, Frank J.; Koletar, Susan L.; Lake, Jordan E.; Post, Wendy S.; Brown, Todd T.

    2017-01-01

    Background Lower muscle density on computed tomography (CT) provides a measure of fatty infiltration of muscle, an aspect of muscle quality that has been associated with metabolic abnormalities, weakness, decreased mobility, and increased fracture risk in older adults. We assessed the cross-sectional relationship between HIV serostatus, age, thigh muscle attenuation, and thigh muscle cross-sectional area (CSA). Methods Mean CT-quantified Hounsfield units (HU) of the thigh muscle bundle and CSA were evaluated in 368 HIV-infected and 145 HIV-uninfected men enrolled in the Multicenter AIDS Cohort Study (MACS) Cardiovascular Substudy using multivariable linear regression. Models all were adjusted for HIV serostatus, age, race, and body mass index (BMI); each model was further adjusted for covariates that differed by HIV serostatus, including insulin resistance, hepatitis C, malignancy, smoking, alcohol use, and self-reported limitation in physical activity. Results HIV-infected men had greater thigh muscle CSA (p<0.001) but lower muscle density (p<0.001) compared to HIV-uninfected men. Muscle density remained lower in HIV-infected men (p = 0.001) when abdominal visceral adiposity, and thigh subcutaneous adipose tissue area were substituted for BMI in a multivariable model. Muscle density decreased by 0.16 HU per year (p<0.001) of increasing age among the HIV-infected men, but not in the HIV-uninfected men (HIV x age interaction -0.20 HU; p = 0.002). Conclusion HIV-infected men had lower thigh muscle density compared to HIV-uninfected men, and a more pronounced decline with increasing age, indicative of greater fatty infiltration. These findings suggest that lower muscle quality among HIV-infected persons may be a risk factor for impairments in physical function with aging. PMID:28060856

  9. Structures in the Milky Way’s Halo System using the Age Distribution of Field Horizontal-Branch Stars

    NASA Astrophysics Data System (ADS)

    Lentner, Geoffrey; Beers, Timothy C.; Placco, Vinicius M.; Carollo, Daniela; Whitten, Deven; Denissenkov, Pavel; Santucci, Rafael; Rossi, Silvia

    2017-01-01

    Twenty five years ago it was demonstrated that the colors of blue horizontal-branch (BHB) stars in the halo of the Milky Way correlate with age (Preston et al., 1991). More recently, this property of BHB stars has been used to construct chronographic (age) maps of the Galaxy (Santucci et al., 2015; Carollo et al., 2016), which revealed the presence of substructures on the basis of the age contrast between younger accreted satellites with respect to the diffuse halo field stars, and, for the first time, obtained an empirical estimate of the age gradient for the halo of the Galaxy based on field BHB stars. These maps also indicated the presence of an ancient chronographic sphere, including the oldest BHB stars, extending from close to the Galactic center out to some 10-15 kpc.We extend these studies making use of deeper u-band photometry from the recent public data release of the SCUSS survey (Zou et al., 2016). We also describe application of a new grid of ages that takes into account both metallicity and colors for BHB stars.By building deeper chronographic maps we can better explore the age structures that are revealed. Up- coming large surveys, including the public release of Pan-STARRS, as well as photometry from the Dark Energy Survey, will further add to these efforts.This work received partial support from PHY 14-30152; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE), awarded by the US National Science Foundation.

  10. Protein repair L-isoaspartyl methyltransferase in plants. Phylogenetic distribution and the accumulation of substrate proteins in aged barley seeds.

    PubMed Central

    Mudgett, M B; Lowenson, J D; Clarke, S

    1997-01-01

    Protein L-isoaspartate (D-aspartate) O-methyltransferases (MTs; EC 2.1.1.77) can initiate the conversion of detrimental L-isoaspartyl residues in spontaneously damaged proteins to normal L-aspartyl residues. We detected this enzyme in 45 species from 23 families representing most of the divisions of the plant kingdom. MT activity is often localized in seeds, suggesting that it has a role in their maturation, quiescence, and germination. The relationship among MT activity, the accumulation of abnormal protein L-isoaspartyl residues, and seed viability was explored in barley (Hordeum vulgare cultivar Himalaya) seeds, which contain high levels of MT. Natural aging of barley seeds for 17 years resulted in a significant reduction in MT activity and in seed viability, coupled with increased levels of "unrepaired" L-isoaspartyl residues. In seeds heated to accelerate aging, we found no reduction of MT activity, but we did observe decreased seed viability and the accumulation of isoaspartyl residues. Among populations of accelerated aged seed, those possessing the highest levels of L-isoaspartyl-containing proteins had the lowest germination percentages. These results suggest that the MT present in seeds cannot efficiently repair all spontaneously damaged proteins containing altered aspartyl residues, and their accumulation during aging may contribute to the loss of seed viability. PMID:9414558

  11. Age-related shifts in the density and distribution of genetic marker water quality indicators in cow and calf feces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent studies have shown that different adult bovine animal feeding practices dramatically influence fecal indicator bacteria shedding, however very little is known about milk-fed calves. Calves (= 6 months of age) make up about 16% of the current bovine population in the United States and can exc...

  12. Age-Related Shifts in the Density and Distribution of Genetic Marker Water Quality Indicators in Cow and Calf Feces

    EPA Science Inventory

    Recent studies have shown that different adult bovine animal feeding practices dramatically influence fecal indicator bacteria shedding, however very little is known about juvenile milk-fed calves. Calves (≤ 6 months of age) make up about 16% of the current bovine population in ...

  13. Size and age distributions of Juvenile Connecticut River American shad above Hadley Falls: Influence on outmigration representation and timing

    USGS Publications Warehouse

    O'Donnell, M. J.; Letcher, B.H.

    2008-01-01

    Age- and size-based habitat use and movement patterns of young-of-year American shad in rivers are not well understood. Adult females reach their natal rivers at different times and ascend the river at different rates, which may lead to variation of hatch dates at a single location. Also, shad are serial spawners, so eggs of the same female may be released at different distances from the river mouth. It has long been hypothesized that juvenile shad emigration is a function of size or age, and not necessarily keyed only to a decrease in water temperature during the fall. We seined three sites in the Connecticut River biweekly to collect pre-migrant shad during river residence (spring to fall). During emigration, samples were also collected weekly at two hydroelectric facilities. Otoliths were removed from ???20% of the fish to obtain age and growth rate information. We found increases in length and age over time until late in the season, after which such increases were mostly insigniftlant. Cohorts collected early in the year as pre-migrants were never sampled as migrants later in the year at the hydroelectric projects. Cohorts collected late in the year as migrants were never collected earlier in the year as pre-migrants. Only during a narrow window of time were fish collected as both pre-migrants and migrants. Fish that were hatched later in the season exhibited higher growth rates than fish that were hatched earlier in the season. Copyright ?? 2008 John Wiley & Sons, Ltd.

  14. Shifts in depth distributions of alewives, rainbow smelt, and age-2 lake trout in southern Lake Ontario following establishment of Dreissenids

    USGS Publications Warehouse

    O'Gorman, Robert; Elrod, Joseph H.; Owens, Randall W.; Schneider, Clifford P.; Eckert, Thomas H.; Lantry, Brian F.

    2000-01-01

    In the mid-1990s, biologists conducting assessments of fish stocks in Lake Ontario reported finding alewives Alosa pseudoharengus, rainbow smelt Osmerus mordax, and juvenile lake trout Salvelinus namaycush at greater depths than in the mid-1980s. To determine if depth distributions shifted coincident with the early 1990s colonization of Lake Ontario by exotic Dreissena mussels, we calculated mean depth of capture for each of the three species during trawl surveys conducted annually during 1978–1997 and examined the means for significant deviations from established patterns. We found that mean capture depth of alewives, rainbow smelt, and age-2 lake trout shifted deeper during the build up of the dreissenid population in Lake Ontario but that timing of the shift varied among seasons and species. Depth shifts occurred first for rainbow smelt and age-2 lake trout in June 1991. In 1992, alewives shifted deeper in June followed by age-2 lake trout in July–August. Finally, in 1993 and 1994, the distribution of lake trout and alewives shifted in April–May. Reasons why the three fishes moved to deeper water are not clear, but changes in distribution were not linked to temperature. Mean temperature of capture after the depth shift was significantly lower than before the depth shift except for alewives in April–May. Movement of alewives, rainbow smelt, and age-2 lake trout to colder, deeper water has the potential to alter growth and reproduction schedules by exposing the fish to different temperature regimes and to alter the food chain, increasing predation on Mysis relicta in deep water and decreasing alewife predation on lake trout fry over nearshore spawning grounds in spring.

  15. Changes in sex and non-sex hormones and distribution of erythrocyte antigens in reproductive age women with tumors of body of uterus in Adjara.

    PubMed

    Nakashidze, I; Kotrikadze, N; Diasamidze, A; Nagervadze, M; Ramishvili, L

    2013-04-01

    The aim the research was to study the hormonal state of reproductive age women with tumors of body of uterus. The quantitative changes of sex steroid hormones: progesterone (P), estradiol (E), testosterone (T), gonadotropine -Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) were investigated. Distribution of ABO blood group antigens and Rh-Hr systems genetic variants in the blood of women living in Adjara Region was also studied. For study was used reproductive age women's blood with benign (fibromioma) and malignant (endometrial cancer) tumors of body of uterus (the middle age was 20-45 years). The determination of hormones was made by the enzymatic analysis method (ELAIZA). For the research of blood groups, were used the immunoserologic methods. The study have revealed that in blood of reproductive age women with benign and malignant tumors of body of uterus, level of estradiol was increased while levels of progesterone and testosterone were sharply reduced. Amount of Follicle-stimulating hormone and Luteinizing hormone were also increased. It's significant that, both hormones were sharply increased in case of cancer of body of uterus, in comparison with control group and benign tumor. According to distribution of ABO blood group phenotypes - O (I) phenotypic group of ABO system has its highest frequency in blood of women with cancer of body of uterus. Cancer of body of uterus is associated with O (I) phenotypic groups; benign tumor of body of uterus - with A(II) and AB(IV) phenotypic groups. Women with cc and EE genetic variants of Rh-Hr system have sensitivity to the development of benign and malignant tumors of body of uterus; women with ee genetic variant have lower sensitivity towards body of uterus cancer and sharply expressed sensitivity to uterus benign tumors. In women with malignant tumors of body of uterus the frequency of distribution of Rh-Hr system CC genetic variant was sharply reduced.

  16. Phylogenetically related and ecologically similar carnivores harbour similar parasite assemblages.

    PubMed

    Huang, Shan; Bininda-Emonds, Olaf R P; Stephens, Patrick R; Gittleman, John L; Altizer, Sonia

    2014-05-01

    Most parasites infect multiple hosts, but what factors determine the range of hosts a given parasite can infect? Understanding the broad scale determinants of parasite distributions across host lineages is important for predicting pathogen emergence in new hosts and for estimating pathogen diversity in understudied host species. In this study, we used a new data set on 793 parasite species reported from free-ranging populations of 64 carnivore species to examine the factors that influence parasite sharing between host species. Our results showed that parasites are more commonly shared between phylogenetically related host species pairs. Additionally, host species with higher similarity in biological traits and greater geographic range overlap were also more likely to share parasite species. Of three measures of phylogenetic relatedness considered here, the number divergence events that separated host species pairs most strongly influenced the likelihood of parasite sharing. We also showed that viruses and helminths tend to infect carnivore hosts within more restricted phylogenetic ranges than expected by chance. Overall, our results underscore the importance of host evolutionary history in determining parasite host range, even when simultaneously considering other factors such as host ecology and geographic distribution.

  17. Intima-media thickness of the carotid artery and the distribution of lipoprotein subclasses in men aged 40 to 49 years between whites in the United States and the Japanese in Japan for the ERA JUMP study.

    PubMed

    Sekikawa, Akira; Ueshima, Hirotsugu; Sutton-Tyrrell, Kim; Kadowaki, Takashi; El-Saed, Aiman; Okamura, Tomonori; Takamiya, Tomoko; Ueno, Yoshiki; Evans, Rhobert W; Nakamura, Yasuyuki; Edmundowicz, Daniel; Kashiwagi, Atsunori; Maegawa, Hiroshi; Kuller, Lewis H

    2008-02-01

    In men in the post-World War II birth cohort, that is, men aged 40 to 49 years, whites in the United States had significantly higher levels of intima-media thickness of the carotid arteries (IMT) than the Japanese in Japan (Electron-Beam Tomography and Risk Assessment Among Japanese and US Men in the Post World War II Birth Cohort [ERA JUMP] study). The difference remained after adjusting for traditional risk factors. Primary genetic effects are unlikely, given the degree to which IMT is increased in the Japanese who migrated to the United States. We investigated whether the differences in the distributions of lipoprotein subclasses explain the difference in IMT between the 2 populations. We examined population-based samples of 466 randomly selected men aged 40 to 49 years (215 whites from Allegheny County, Pennsylvania, and 241 Japanese from Kusatsu, Shiga, Japan). Lipoprotein subclasses were determined by nuclear magnetic resonance (NMR) spectroscopy. The whites had significantly higher levels of large very low-density lipoprotein particles and significantly lower levels of large high-density lipoprotein particles than the Japanese, whereas the 2 populations had similar levels of small low-density lipoprotein particles. The 2 populations had similar associations of IMT with NMR lipoproteins. Adjusting for NMR lipoproteins did not attenuate the significant difference in IMT between the 2 populations (0.671 +/- 0.006 mm for the whites and 0.618 +/- 0.006 mm for the Japanese, P = .01, mean +/- SE). Differences in the distributions of NMR lipoproteins between the 2 populations did not explain the higher IMT in the whites.

  18. Age- and Sex-Dependent Values of the Distribution of Body Composition Parameters Among Chinese Children Using the Hattori Chart.

    PubMed

    Guo, Bin; Hu, Li; Wu, Qiulian; Gong, Jian; Xu, Hao

    This study aimed to examine the relationship between the fat-free mass (FFM) and fat mass (FM) and between the fat-free mass index (FFMI) and fat mass index (FMI) in Chinese children using the Hattori chart and to compare the changing pattern with Korean counterparts. In this study, 1541 (764 girls) children and adolescents aged 5-19 yr were recruited from southern China. The subjects' body composition was measured using dual-energy X-ray absorptiometry. The relationship between FFM and FM and between FFMI and FMI were delineated using the Hattori chart. Between 5 and 12 yr, a concurrent increase in FFM and FM and in FFMI and FMI was found in both sexes. After 12 yr, the age-related changing patterns are generally characterized by a sharp increase in FM, with a relatively small increase in FFM for girls, and a sharp increase in FFM, with a relatively little fluctuation in FM for boys. The increase in weight and BMI with age for this stage is largely due to the increase in FFM and FFMI in boys and in both the FFM and FM and FFMI and FMI components in girls. Sex differences in the patterns of body composition were found in Chinese children and adolescents.

  19. Distribution of molar mass and branching index of natural rubber from Hevea brasiliensis trees of different age by size exclusion chromatography coupled with online viscometry.

    PubMed

    Phan, T N; Lan, N T; Nga, N T

    2004-05-01

    Natural rubber from hevea brasiliensis trees (Thailand, RRIM 600 clone) of different age (8, 20, and 35 years) were characterized by size exclusion chromatography coupled with online viscometry according to their distribution of molar mass and branching index at a temperature of 70 degrees C using cyclohexane as solvent. Washing with an aqueous solution of sodium dodecylsulfate and subsequent saponification purified the natural rubber samples. With this procedure physical branching points caused by phospholipids, proteins and hydrophobic terminal units, mainly fatty acids, of the natural rubber (cis-1,4-polyisoprene) molecule, could be removed leading to completely soluble polymer samples. All samples investigated possess a very broad (10 to 50,000 kg/mol) and distinct bimodal molar mass distribution. With increasing age the peak area in the low molar mass region decreases favoring the peak area in the high molar mass region. By plotting the branching index as a function of the both, the molar mass and the age of the trees.

  20. A cross-sectional study of age-related changes in plantar pressure distribution between 4 and 7 years: a comparison of regional and pixel-level analyses.

    PubMed

    Phethean, Jill; Pataky, Todd C; Nester, Christopher J; Findlow, Andrew H

    2014-01-01

    Quantifying morphological and functional development in children's feet, and thereby establishing development norms is difficult. In addition to practical challenges of experimentation on children, measurement equipment like plantar pressure (PP) platforms are almost exclusively geared towards adult-sized feet. These PP quantification problems may be exacerbated by typical regional data analysis techniques, which further reduce spatial resolution. The goal of this study was to quantify PP distributions in developing children, and also to compare the results obtained from typical (regional) techniques with those obtained from a higher-resolution (pixel-level) technique. Ninety-eight children between four and seven years of age were assessed in a cross-sectional design. Maximum PP distributions were collected for each child, and these pressures were linearly regressed against age. Present results agree with previous investigations in that maximum pressures and maximum pressure changes occurred in the forefoot. However, results from the present pixel-level technique suggest that these changes are limited to the central metatarsals, and that regional methods can suggest significance where none exists in the actual raw (pixel-level) data, due to signal aliasing and, in particular, to conflation of regional boundaries. We postulate that increased central metatarsal pressures are reflective of the coupling between generalised joint laxity decreases and relatively increasingly inclined central metatarsal bones with age.

  1. Classical distributive justice and the European healthcare system: rethinking the foundations of European health care in an age of crises.

    PubMed

    Bauzon, Stéphane

    2015-04-01

    The state subvention and distribution of health care not only jeopardize the financial sustainability of the state, but also restrict without a conclusive rational basis the freedom of patients to decide how much health care and of what quality is worth what price. The dominant biopolitics of European health care supports a healthcare monopoly in the hands of the state and the medical profession, which health care should be (re)opened to the patient's authority to deal directly for better basic health care. In a world where it is impossible for all to receive equal access to the best of basic health care, one must critically examine the plausible scope of the authority of the state to limit access to better basic health care. Classical distributive justice affords a basis for re-examining the current European ideology of equality, human dignity, and solidarity that supports healthcare systems with unsustainable egalitarian concerns.

  2. Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in Southwestern Alaska and the Alaska Peninsula

    USGS Publications Warehouse

    Dusel-Bacon, Cynthia; Doyle, Elizabeth O.; Box, Stephen E.

    1996-01-01

    The oldest dated metamorphic sequence in Alaska, the fault-bounded Kilbuck Terrane, consists of continental rocks that were metamorphosed under amphibolite-facies conditions during early Proterozoic (1.77 Ga) time. Proterozoic or early Paleozoic metamorphic ages are also possible for greenschist- and amphibolite-facies continental rocks in interior Alaska (Ruby and Nixon Fork terranes). Medium-grade metamorphism on the Alaska Peninsula accompanied intrusion of a Jurassic arc. North of Bristol Bay, low-grade, locally high-pressure Mesozoic metamorphism is attributed to the progressive underthrusting of a subduction complex beneath an oceanic arc followed by underthrusting of the Kilbuck Terrane beneath the subduction complex.

  3. The Q-CHAT (Quantitative CHecklist for Autism in Toddlers): a normally distributed quantitative measure of autistic traits at 18-24 months of age: preliminary report.

    PubMed

    Allison, Carrie; Baron-Cohen, Simon; Wheelwright, Sally; Charman, Tony; Richler, Jennifer; Pasco, Greg; Brayne, Carol

    2008-09-01

    We report a major revision of the CHecklist for Autism in Toddlers (CHAT). This quantitative CHAT (Q-CHAT) contains 25 items, scored on a 5 point scale (0-4). The Q-CHAT was completed by parents of n = 779 unselected toddlers (mean age 21 months) and n = 160 toddlers and preschoolers (mean age 44 months) with an Autism Spectrum Condition (ASC). The ASC group (mean (SD) = 51.8 (14.3)) scored higher on the Q-CHAT than controls (26.7 (7.8)). Boys in the control group (27.5 (7.8)) scored higher than girls (25.8 (7.7)). The intraclass correlation for test-retest reliability was 0.82 (n = 330). The distribution in the control group was close to normal. Full examination of the clinical validity of the Q-CHAT and test properties is underway.

  4. Weight-for-age standard score - distribution and effect on in-hospital mortality: A retrospective analysis in pediatric cardiac surgery

    PubMed Central

    George, Antony; Jagannath, Pushpa; Joshi, Shreedhar S.; Jagadeesh, A. M.

    2015-01-01

    Objective: To study the distribution of weight for age standard score (Z score) in pediatric cardiac surgery and its effect on in-hospital mortality. Introduction: WHO recommends Standard Score (Z score) to quantify and describe anthropometric data. The distribution of weight for age Z score and its effect on mortality in congenital heart surgery has not been studied. Methods: All patients of younger than 5 years who underwent cardiac surgery from July 2007 to June 2013, under single surgical unit at our institute were enrolled. Z score for weight for age was calculated. Patients were classified according to Z score and mortality across the classes was compared. Discrimination and calibration of the for Z score model was assessed. Improvement in predictability of mortality after addition of Z score to Aristotle Comprehensive Complexity (ACC) score was analyzed. Results: The median Z score was -3.2 (Interquartile range -4.24 to -1.91] with weight (mean±SD) of 8.4 ± 3.38 kg. Overall mortality was 11.5%. 71% and 52.59% of patients had Z score < -2 and < -3 respectively. Lower Z score classes were associated with progressively increasing mortality. Z score as continuous variable was associated with O.R. of 0.622 (95% CI- 0.527 to 0.733, P < 0.0001) for in-hospital mortality and remained significant predictor even after adjusting for age, gender, bypass duration and ACC score. Addition of Z score to ACC score improved its predictability for in-hosptial mortality (δC - 0.0661 [95% CI - 0.017 to 0.0595, P = 0.0169], IDI- 3.83% [95% CI - 0.017 to 0.0595, P = 0.00042]). Conclusion: Z scores were lower in our cohort and were associated with in-hospital mortality. Addition of Z score to ACC score significantly improves predictive ability for in-hospital mortality. PMID:26139742

  5. The Value of Measurement of Macular Carotenoid Pigment Optical Densities and Distributions in Age-Related Macular Degeneration and Other Retinal Disorders

    PubMed Central

    Bernstein, Paul S.; Delori, François C.; Richer, Stuart; van Kuijk, Frederik J. M.; Wenzel, Adam J.

    2009-01-01

    There is increasing recognition that the optical and antioxidant properties of the xanthophyll carotenoids lutein and zeaxanthin play an important role in maintaining the health and function of the human macula. In this review article, we assess the value of non-invasive quantification of macular pigment levels and distributions to identify individuals potentially at risk for visual disability or catastrophic vision loss from age-related macular degeneration, and we consider the strengths and weaknesses of the diverse measurement methods currently available. PMID:19854211

  6. Influence of secondary preparative parameters and aging effects on PLGA particle size distribution: a sedimentation field flow fractionation investigation.

    PubMed

    Contado, Catia; Vighi, Eleonora; Dalpiaz, Alessandro; Leo, Eliana

    2013-01-01

    Poly(lactic-co-glycolic acid) particles in the 200-400-nm size range were formulated through nanoprecipitation and solvent evaporation methods. Different concentrations of the polymer and stabilizer (Pluronic® F 68) were tested in order to identify the best conditions for making poly(lactic-co-glycolic acid) particles of suitable size, stable in time, and to be used as carriers for brain-targeting drugs. The particles with the best characteristics for delivery system design were those formulated by nanoprecipitation with an organic/water phase ratio of 2:30, a polymer concentration of 25 mg/mL, and a surfactant concentration of 0.83 mg/mL; their surface charge was reasonably negative (approximately -27 mV) and the average size of the almost monodisperse population was roughly 250 nm. Particle characterization was obtained through ζ-potential measurements, scanning electron microscope observations, and particle size distribution determinations; the latter achieved by both photon-correlation spectroscopy and sedimentation field flow fractionation. Sedimentation field flow fractionation, which is considered more reliable than photon-correlation spectroscopy in describing the possible particle size distribution modifications, was used to investigate the effects of 3 months of storage at 4 °C had on the lyophilized particles. Figure Particle size ditribution from the SdFFF and the PCS techniques.

  7. Three ages of Venus

    NASA Technical Reports Server (NTRS)

    Wood, Charles A.; Coombs, Cassandra R.

    1989-01-01

    A central question for any planet is the age of its surface. Based on comparative planetological arguments, Venus should be as young and active as the Earth (Wood and Francis). The detection of probable impact craters in the Venera radar images provides a tool for estimating the age of the surface of Venus. Assuming somewhat different crater production rates, Bazilevskiy et al. derived an age of 1 + or - 0.5 billion years, and Schaber et al. and Wood and Francis estimated an age of 200 to 400 million years. The known impact craters are not randomly distributed, however, thus some area must be older and others younger than this average age. Ages were derived for major geologic units on Venus using the Soviet catalog of impact craters (Bazilevskiy et al.), and the most accessible geologic unit map (Bazilevskiy). The crater counts are presented for (diameters greater than 20 km), areas, and crater densities for the 7 terrain units and coronae. The procedure for examining the distribution of craters is superior to the purely statistical approaches of Bazilevskiy et al. and Plaut and Arvidson because the bins are larger (average size 16 x 10(6) sq km) and geologically significant. Crater densities define three distinct groups: relatively heavily cratered (Lakshmi, mountain belts), moderately cratered (smooth and rolling plains, ridge belts, and tesserae), and essentially uncratered (coronae and domed uplands). Following Schaber et al., Grieve's terrestrial cratering rate of 5.4 + or - 2.7 craters greater than 20 km/10(9) yrs/10(6) sq km was used to calculate ages for the geologic units on Venus. To improve statistics, the data was aggregated into the three crater density groups, deriving the ages. For convenience, the three similar age groups are given informal time stratigraphic unit names, from youngest to oldest: Ulfrunian, Sednaian, Lakshmian.

  8. Variation in Carbon Storage and Its Distribution by Stand Age and Forest Type in Boreal and Temperate Forests in Northeastern China

    PubMed Central

    Wei, Yawei; Li, Maihe; Chen, Hua; Lewis, Bernard J.; Yu, Dapao; Zhou, Li; Zhou, Wangming; Fang, Xiangmin; Zhao, Wei; Dai, Limin

    2013-01-01

    The northeastern forest region of China is an important component of total temperate and boreal forests in the northern hemisphere. But how carbon (C) pool size and distribution varies among tree, understory, forest floor and soil components, and across stand ages remains unclear. To address this knowledge gap, we selected three major temperate and two major boreal forest types in northeastern (NE) China. Within both forest zones, we focused on four stand age classes (young, mid-aged, mature and over-mature). Results showed that total C storage was greater in temperate than in boreal forests, and greater in older than in younger stands. Tree biomass C was the main C component, and its contribution to the total forest C storage increased with increasing stand age. It ranged from 27.7% in young to 62.8% in over-mature stands in boreal forests and from 26.5% in young to 72.8% in over-mature stands in temperate forests. Results from both forest zones thus confirm the large biomass C storage capacity of old-growth forests. Tree biomass C was influenced by forest zone, stand age, and forest type. Soil C contribution to total forest C storage ranged from 62.5% in young to 30.1% in over-mature stands in boreal and from 70.1% in young to 26.0% in over-mature in temperate forests. Thus soil C storage is a major C pool in forests of NE China. On the other hand, understory and forest floor C jointly contained less than 13% and <5%, in boreal and temperate forests respectively, and thus play a minor role in total forest C storage in NE China. PMID:23977252

  9. Variation in carbon storage and its distribution by stand age and forest type in boreal and temperate forests in northeastern China.

    PubMed

    Wei, Yawei; Li, Maihe; Chen, Hua; Lewis, Bernard J; Yu, Dapao; Zhou, Li; Zhou, Wangming; Fang, Xiangmin; Zhao, Wei; Dai, Limin

    2013-01-01

    The northeastern forest region of China is an important component of total temperate and boreal forests in the northern hemisphere. But how carbon (C) pool size and distribution varies among tree, understory, forest floor and soil components, and across stand ages remains unclear. To address this knowledge gap, we selected three major temperate and two major boreal forest types in northeastern (NE) China. Within both forest zones, we focused on four stand age classes (young, mid-aged, mature and over-mature). Results showed that total C storage was greater in temperate than in boreal forests, and greater in older than in younger stands. Tree biomass C was the main C component, and its contribution to the total forest C storage increased with increasing stand age. It ranged from 27.7% in young to 62.8% in over-mature stands in boreal forests and from 26.5% in young to 72.8% in over-mature stands in temperate forests. Results from both forest zones thus confirm the large biomass C storage capacity of old-growth forests. Tree biomass C was influenced by forest zone, stand age, and forest type. Soil C contribution to total forest C storage ranged from 62.5% in young to 30.1% in over-mature stands in boreal and from 70.1% in young to 26.0% in over-mature in temperate forests. Thus soil C storage is a major C pool in forests of NE China. On the other hand, understory and forest floor C jointly contained less than 13% and <5%, in boreal and temperate forests respectively, and thus play a minor role in total forest C storage in NE China.

  10. Obesity and related consequences to ageing.

    PubMed

    Jura, Magdalena; Kozak, Leslie P

    2016-02-01

    Obesity has become a major public health problem. Given the current increase in life expectancy, the prevalence of obesity also raises steadily among older age groups. The increase in life expectancy is often accompanied with additional years of susceptibility to chronic ill health associated with obesity in the elderly. Both obesity and ageing are conditions leading to serious health problems and increased risk for disease and death. Ageing is associated with an increase in abdominal obesity, a major contributor to insulin resistance and the metabolic syndrome. Obesity in the elderly is thus a serious concern and comprehension of the key mechanisms of ageing and age-related diseases has become a necessary matter. Here, we aimed to identify similarities underlying mechanisms related to both obesity and ageing. We bring together evidence that age-related changes in body fat distribution and metabolism might be key factors of a vicious cycle that can accelerate the ageing process and onset of age-related diseases.

  11. Distribution and inferred age of exfoliation joints in the Aar Granite of the central Swiss Alps and relationship to Quaternary landscape evolution

    NASA Astrophysics Data System (ADS)

    Ziegler, Martin; Loew, Simon; Moore, Jeffrey R.

    2013-11-01

    Exfoliation joints are well-known natural fractures limited to near the ground surface. Relatively few details, however, are known about their distribution and age in the Swiss Alps. Exfoliation joints follow the landscape surface at the time of their formation; the age of the associated landscape feature then provides a maximum age of exfoliation joints. While landscape forms can change through time, exfoliation joints preserve elements of former landscape morphologies by their undisturbed orientations. The Grimsel region of the Central Alps is well-suited for analyzing the impact of erosional episodes, and accompanying stress changes, on exfoliation joint formation in granitic rocks. Mapping above and below ground revealed that exfoliation joints are widespread and occur between valley bottoms and mountain crests within glacial (inner and hanging U-shaped trough valleys, glacial cirques, and steep mountain crests) and predominantly fluvial landforms (gently inclined linear slopes above the inner trough valleys, narrow inner-valley gorges, and steep V-shaped side gullies). Based primarily on their geometric properties at the ground surface, three exfoliation joint types were distinguished in our study area: (1) closely spaced (< 1 m) joints oriented distinctly parallel to the present-day ground surface, (2) intermediately spaced (0.6-2 m) joints that are nearly parallel (< 10° difference) to today's mean ground surface at a 10-m scale, and (3) widely spaced (≫ 2 m) joints not parallel to the ground surface. Relating the mapped distribution of exfoliation joint types to identified erosional episodes and landscape features of known and inferred ages, respectively, enables us to distinguish four exfoliation joint generations in the Grimsel area, which most likely formed during the lower Pleistocene (~ 1.5-1 Ma), middle Pleistocene (~ 0.7-0.4 Ma), upper Pleistocene (0.1-0.02 Ma), and Late Glacial/Holocene (< 0.02 Ma). We demonstrate that the most prominent and

  12. Cosmic rays in a dynamical halo. I - Age and matter traversal distributions and anisotropy for nuclei. II - Electrons

    NASA Technical Reports Server (NTRS)

    Owens, A. J.; Jokipii, J. R.

    1977-01-01

    Recent measurements of the mean lifetime of galactic cosmic rays (at least 10 million yr) have suggested a dynamical halo model of cosmic-ray confinement to the Galaxy. A one-dimensional version of the model is analyzed to determine the ranges of parameters required to give self-consistent values of the mean lifetime, matter traversed, anisotropy, and interstellar gamma-ray flux. It is found that the ranges of the parameters are: disk scale height of 4000-10,000 pc, average convection velocity of no more than 60 km/s, and diffusion coefficient of (3-10) by 10 to the 28th power sq cm/sec for particles with charges of the order of 10 GV. Some consequences for this model of a much shorter lifetime are also discussed. The energy spectrum and spatial distribution of electrons in the dynamical halo model are considered. A gradual steepening of the electron energy spectrum beginning at several GeV energy is found, as indicated by observations. The decrease of electron density with height in the halo depends on the particle energy and may be much steeper than that for nuclei. The models give a halo with a scale height of the order of 3 kpc for several-GeV electrons, which is shown to be consistent with radio observations.

  13. Distribution of body composition index and the relationship with blood pressure among children aged 7 to 12 years in Shandong, China.

    PubMed

    Zhang, Ying-Xiu; Wang, Shu-Rong

    2012-11-01

    Body mass index (BMI) is widely used to assess the prevalence of childhood obesity in populations, and the relationship of BMI with blood pressure has been observed. However, no study has reported on the distribution of body composition index and the relationship with blood pressure. The present study examined the distribution of body composition index and the relationship with blood pressure among children aged 7 to 12 years in Shandong, China. A total of 4326 students (2165 boys and 2161 girls) aged 7 to 12 years participated in this study. Height, weight, skinfold thickness, and blood pressure of all the subjects were measured. Body fat percentage (BF%) was calculated by regression equation, and fat mass index (FMI) and fat-free mass index (FFMI) were calculated according to following expressions: FMI = BF% × weight/height(2) and FFMI = (weight - BF% × weight)/height(2). The 50th percentile values of FMI and FFMI increased with age in both sexes. The mean values of FFMI were significantly higher in boys than in girls (P < .01), but no statistically significant differences in mean FMI between the 2 sexes were observed (P > .05). Both systolic blood pressure and diastolic blood pressure were significantly positively related to FMI and FFMI in both boys and girls (P < .05). FMI and FFMI are potentially useful in evaluating the body composition of individuals with different stature. There is a strong positive relationship between FMI and blood pressure in children; these findings emphasize the importance of the prevention of obesity in children and adolescents.

  14. Age, distribution and style of deformation in Alaska north of 60°N: Implications for assembly of Alaska

    USGS Publications Warehouse

    Moore, Thomas; Box, Stephen E.

    2016-01-01

    The structural architecture of Alaska is the product of a complex history of deformation along both the Cordilleran and Arctic margins of North America involving oceanic plates, subduction zones and strike-slip faults and with continental elements of Laurentia, Baltica, and Siberia. We use geological constraints to assign regions of deformation to 14 time intervals and to map their distributions in Alaska. Alaska can be divided into three domains with differing deformational histories. Each domain includes a crustal fragment that originated near Early Paleozoic Baltica. The Northern domain experienced the Early Cretaceous Brookian orogeny, an oceanic arc-continent collision, followed by mid-Cretaceous extension. Early Cretaceous opening of the oceanic Canada Basin rifted the orogen from the Canadian Arctic margin, producing the bent trends of the orogen. The second (Southern) domain consists of Neoproterozoic and younger crust of the amalgamated Peninsular-Wrangellia-Alexander arc terrane and its paired Mesozoic accretionary prism facing the Pacific Ocean basin. The third (Interior) domain, situated between the first two domains and roughly bounded by the Cenozoic dextral Denali and Tintina faults, includes the large continental Yukon Composite and Farewell terranes having different Permian deformational episodes. Although a shared deformation that might mark their juxtaposition by collisional processes is unrecognized, sedimentary linkage between the two terranes and depositional overlap of the boundary with the Northern domain occurred by early Late Cretaceous. Late Late Cretaceous deformation is the first deformation shared by all three domains and correlates temporally with emplacement of the Southern domain against the remainder of Alaska. Early Cenozoic shortening is mild across interior Alaska but is significant in the Brooks Range, and correlates in time with dextral faulting, ridge subduction and counter-clockwise rotation of southern Alaska. Late Cenozoic

  15. Age, distribution and style of deformation in Alaska north of 60°N: Implications for assembly of Alaska

    NASA Astrophysics Data System (ADS)

    Moore, Thomas E.; Box, Stephen E.

    2016-11-01

    The structural architecture of Alaska is the product of a complex history of deformation along both the Cordilleran and Arctic margins of North America involving oceanic plates, subduction zones and strike-slip faults and with continental elements of Laurentia, Baltica, and Siberia. We use geological constraints to assign regions of deformation to 14 time intervals and to map their distributions in Alaska. Alaska can be divided into three domains with differing deformational histories. Each domain includes a crustal fragment that originated near Early Paleozoic Baltica. The Northern domain experienced the Early Cretaceous Brookian orogeny, an oceanic arc-continent collision, followed by mid-Cretaceous extension. Early Cretaceous opening of the oceanic Canada Basin rifted the orogen from the Canadian Arctic margin, producing the bent trends of the orogen. The second (Southern) domain consists of Neoproterozoic and younger crust of the amalgamated Peninsular-Wrangellia-Alexander arc terrane and its paired Mesozoic accretionary prism facing the Pacific Ocean basin. The third (Interior) domain, situated between the first two domains and roughly bounded by the Cenozoic dextral Denali and Tintina faults, includes the large continental Yukon Composite and Farewell terranes having different Permian deformational episodes. Although a shared deformation that might mark their juxtaposition by collisional processes is unrecognized, sedimentary linkage between the two terranes and depositional overlap of the boundary with the Northern domain occurred by early Late Cretaceous. Late Late Cretaceous deformation is the first deformation shared by all three domains and correlates temporally with emplacement of the Southern domain against the remainder of Alaska. Early Cenozoic shortening is mild across interior Alaska but is significant in the Brooks Range, and correlates in time with dextral faulting, ridge subduction and counter-clockwise rotation of southern Alaska. Late Cenozoic

  16. Age, distribution, and significance within a sediment budget, of in-channel depositional surfaces in the Normanby River, Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Pietsch, T. J.; Brooks, A. P.; Spencer, J.; Olley, J. M.; Borombovits, D.

    2015-06-01

    We present the results of investigations into alluvial deposition in the catchment of the Normanby River, which flows into Princess Charlotte Bay (PCB) in the northern part of the Great Barrier Reef Lagoon. Our focus is on the fine fraction (< ~ 63 μm) of alluvial deposits that sit above the sand and gravel bars of the channel floor, but below the expansive flat surface generally referred to as the floodplain. Variously described as benches, bank attached bars or inset or inner floodplains, these more or less flat-lying surfaces within the macro-channel have hitherto received little attention in sediment budgeting models. We use high resolution LiDAR based mapping combined with optical dating of exposures cut into these in-channel deposits to compare their aggradation rates with those found in other depositional zones in the catchment, namely the floodplain and coastal plain. In total 59 single grain OSL dates were produced across 21 stratigraphic profiles at 14 sites distributed though the 24 226 km2 catchment. In-channel storage in these inset features is a significant component of the contemporary fine sediment budget (i.e. recent decades/last century), annually equivalent to more than 50% of the volume entering the channel network from hillslopes and subsoil sources. Therefore, at the very least, in-channel storage of fine material needs to be incorporated into sediment budgeting exercises. Furthermore, deposition within the channel has occurred in multiple locations coincident in time with accelerated sediment production following European settlement. Generally, this has occurred on a subset of the features we have examined here, namely linear bench features low in the channel. This suggests that accelerated aggradation on in-channel depositional surfaces has been in part a response to accelerated erosion within the catchment. The entire contribution of ~ 370 kilotonnes per annum of fine sediment estimated to have been produced by alluvial gully erosion over

  17. Etiology of acute otitis media and serotype distribution of Streptococcus pneumoniae and Haemophilus influenzae in Chilean children <5 years of age.

    PubMed

    Rosenblut, Andres; Napolitano, Carla; Pereira, Angelica; Moreno, Camilo; Kolhe, Devayani; Lepetic, Alejandro; Ortega-Barria, Eduardo

    2017-02-01

    The impact of bacterial conjugate vaccines on acute otitis media (AOM) is affected by several factors including population characteristics, bacterial etiology and vaccine conjugation method, carrier, and coverage. This study estimated the baseline etiology, distribution, and antibiotic susceptibility of bacterial serotypes that causes AOM in children aged <5 years in a public setting in Santiago, Chile.Children aged ≥3 months and <5 years referred to the physician for treatment of AOM episodes (with an onset of symptoms <72 h) were enrolled between September 2009 and September 2010. Middle ear fluid (MEF) was collected by tympanocentesis or by otorrhea for identification and serotyping of bacteria. Antibacterial susceptibility was tested using E-test (etrack: 112671).Of 160 children (mean age 27.10 ± 15.83 months) with AOM episodes, 164 MEF samples (1 episode each from 156 children; 2 episodes each from 4 children) were collected. Nearly 30% of AOM episodes occurred in children aged 12 to 23 months. Streptococcus pneumoniae (41.7% [58/139]) and Haemophilus influenzae (40.3% [56/139]) were predominant among the cultures that showed bacterial growth (85% [139/164]). All Streptococcus pneumoniae positive episodes were serotyped, 19F (21%) and 14 (17%) were the predominant serotypes; all Haemophilus influenzae strains were nontypeable. Streptococcus pneumoniae were resistant to penicillin (5%) and erythromycin (33%); Haemophilus influenzae were resistant to ampicillin (14%) and cefuroxime and cefotaxime (2% each).AOM in Chilean children is predominantly caused by Streptococcus pneumoniae and nontypeable Haemophilus influenzae. Use of a broad spectrum vaccine against these pathogens might aid the reduction of AOM in Chile.

  18. DUSTiNGS. III. Distribution of Intermediate-age and Old Stellar Populations in Disks and Outer Extremities of Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    McQuinn, Kristen B. W.; Boyer, Martha L.; Mitchell, Mallory B.; Skillman, Evan D.; Gehrz, R. D.; Groenewegen, Martin A. T.; McDonald, Iain; Sloan, G. C.; van Loon, Jacco Th.; Whitelock, Patricia A.; Zijlstra, Albert A.

    2017-01-01

    We have traced the spatial distributions of intermediate-age and old stars in nine dwarf galaxies in the distant parts of the Local Group, using multi-epoch 3.6 and 4.5 μm data from the DUST in Nearby Galaxies with Spitzer (DUSTiNGS) survey. Using complementary optical imaging from the Hubble Space Telescope, we identify the tip of the red giant branch (TRGB) in the 3.6 μm photometry, separating thermally pulsating asymptotic giant branch stars from the larger red giant branch populations. Unlike the constant TRGB in the I band, at 3.6 μm, the TRGB magnitude varies by ∼0.7 mag, making it unreliable as a distance indicator. The intermediate-age and old stars are well mixed in two-thirds of the sample, with no evidence of a gradient in the ratio of the intermediate-age to old stellar populations outside the central ∼1‧–2‧. Variable AGB stars are detected in the outer extremities of the galaxies, indicating that chemical enrichment from these dust-producing stars may occur in the outer regions of galaxies with some frequency. Theories of structure formation in dwarf galaxies must account for the lack of radial gradients in intermediate-age populations and the presence of these stars in the outer extremities of dwarfs. Finally, we identify unique features in individual galaxies, such as extended tidal features in Sex A and Sag DIG and a central concentration of AGB stars in the inner regions of NGC 185 and NGC 147.

  19. Etiology of acute otitis media and serotype distribution of Streptococcus pneumoniae and Haemophilus influenzae in Chilean children <5 years of age

    PubMed Central

    Rosenblut, Andres; Napolitano, Carla; Pereira, Angelica; Moreno, Camilo; Kolhe, Devayani; Lepetic, Alejandro; Ortega-Barria, Eduardo

    2017-01-01

    Abstract The impact of bacterial conjugate vaccines on acute otitis media (AOM) is affected by several factors including population characteristics, bacterial etiology and vaccine conjugation method, carrier, and coverage. This study estimated the baseline etiology, distribution, and antibiotic susceptibility of bacterial serotypes that causes AOM in children aged <5 years in a public setting in Santiago, Chile. Children aged ≥3 months and <5 years referred to the physician for treatment of AOM episodes (with an onset of symptoms <72 h) were enrolled between September 2009 and September 2010. Middle ear fluid (MEF) was collected by tympanocentesis or by otorrhea for identification and serotyping of bacteria. Antibacterial susceptibility was tested using E-test (etrack: 112671). Of 160 children (mean age 27.10 ± 15.83 months) with AOM episodes, 164 MEF samples (1 episode each from 156 children; 2 episodes each from 4 children) were collected. Nearly 30% of AOM episodes occurred in children aged 12 to 23 months. Streptococcus pneumoniae (41.7% [58/139]) and Haemophilus influenzae (40.3% [56/139]) were predominant among the cultures that showed bacterial growth (85% [139/164]). All Streptococcus pneumoniae positive episodes were serotyped, 19F (21%) and 14 (17%) were the predominant serotypes; all Haemophilus influenzae strains were nontypeable. Streptococcus pneumoniae were resistant to penicillin (5%) and erythromycin (33%); Haemophilus influenzae were resistant to ampicillin (14%) and cefuroxime and cefotaxime (2% each). AOM in Chilean children is predominantly caused by Streptococcus pneumoniae and nontypeable Haemophilus influenzae. Use of a broad spectrum vaccine against these pathogens might aid the reduction of AOM in Chile. PMID:28178138

  20. French registry of acute leukemia and myelodysplastic syndromes. Age distribution and hemogram analysis of the 4496 cases recorded during 1982-1983 and classified according to FAB criteria. Groupe Francais de Morphologie Hematologique

    SciTech Connect

    Not Available

    1987-09-15

    During 1982 and 1983, 4496 new cases were recorded in the French Registry of acute leukemia and myelodysplastic syndromes by the French Group of Hematologic Morphology. This cooperative group associated members of 37 university centers spread throughout France; these centers handle the overwhelming majority of acute leukemias diagnoses. The cases were all classified according to FAB guidelines. Two thousand four hundred ninety-nine cases of acute myeloid leukemia were recorded, with similar total recruitment and distribution by cytologic subclass for both years. Hemogram data analysis revealed significant differences between different classes for certain parameters, particularly leukocytosis. A greater proportion of the acute myelogenous leukemias (AMLs) secondary to chemotherapy and/or radiotherapy (n = 145) were unclassifiable according to the French-American-British (FAB) system than the de novo AMLs (n = 1954). Eight hundred twenty cases of myelodysplastic syndromes were analyzed. Their frequency was underestimated due to optional reporting during the first year and the less favorable position of the university centers for recruiting these syndromes. The characteristics of the hemograms were established for acquired idiopathic sideroblastic anemia (n = 107), refractory anemia with excess blasts (RAEB) (n = 329), chronic myelomonocytic leukemia (n = 129) and RAEB in transformation (n = 65). Analysis of the 1177 acute lymphoblastic leukemias (ALLs) recorded showed good stability from one year to the next in terms of numbers of cases and distribution in the subclasses L1, L2, and L3. The distribution among these three subclasses by age also was determined. For L1 and L2 the hemogram data were examined separately for adults and children. The study of 74 cases of type L3 ALL enabled us to detail the hematologic presentation of this rare form of leukemia.

  1. Fatal accident distribution by age, gender and head injury, and death probability at accident scene in Mashhad, Iran, 2006-2009.

    PubMed

    Zangooei Dovom, Hossein; Shafahi, Yousef; Zangooei Dovom, Mehdi

    2013-01-01

    Several studies have investigated road traffic deaths, but few have compared by road user type. Iran, with an estimated 44 road traffic deaths per 100,000 population in 2002 had higher road traffic deaths than any other country for which reliable estimates can be made. So, the present study was conducted on road death data and identified fatal accident distribution by age, gender and head injury as well as the influences of age and gender on deaths at accident scenes for all road user groups. Data used in this study are on fatal road accidents recorded by forensic medicine experts of the Khorasan Razavi province in Mashhad, the capital of the province, the second largest city and the largest place of pilgrimage, immigration and tourism in Iran. Chi-square test and odds ratio were used to identify the relation of death place with age and gender in 2495 fatal road accidents from 2006 to 2009. The t-test and analysis of variance were employed for continues variable, age, to compare males' and females' mean age for all road user categories. For two genders, all three groups of fatalities (pedestrian, motorcyclist and motor vehicle occupant) had a peak at the ages of 21-30. The youngest were male motorcyclists (mean age = 28). Old pedestrians were included in road deaths very much, too. Male/female overall ratio was 3.41 and the highest male/female ratio was related to motorcyclists (14). The overall ratio of head injury to other organ injuries (torso and underbody) was 2.51 and pedestrians had the largest amount of head injury (38.2%). Regarding death at accident scene, for all road users, gender did not have any significant relation with death at the scene (P-value > 0.1); on the contrary, age had significant relation (P-value < 0.05). Females were more vulnerable at accident scenes (male/female ratio at accident sense < 1). Pedestrians aged 21-30, motorcyclists 41-50 and motor vehicle occupants 31-40 died the most at accident scenes. Identifying the most

  2. Middle Stone Age (MSA) site distributions in eastern Africa and their relationship to Quaternary environmental change, refugia and the evolution of Homo sapiens

    NASA Astrophysics Data System (ADS)

    Basell, Laura S.

    2008-12-01

    This paper considers the evolution of Homo sapiens in eastern Africa in relation to refugia and bottlenecks around ˜200 ka BP, at a macro scale. Middle Stone Age (MSA) lithics, site distributions and locations are analysed in relation to palaeovegetation maps of the last glacial/interglacial cycle, which are used as a proxy for earlier climate cycles. A "push and pull" model is then postulated for the spread of Homo sapiens out of refugia in eastern Africa, involving both volcanism (push) and habitat availability (pull). A date within OIS 5 is suggested for this expansion to other parts of the continent, and potentially further afield, contrary to a frequently proposed expansion within OIS 3.

  3. Magnesium and healthy aging.

    PubMed

    Veronese, Nicola; Zanforlini, Bruno Micael; Manzato, Enzo; Sergi, Giuseppe

    2015-01-01

    Magnesium (Mg) is relatively stable in the intracellular compartment, although decreases linearly with advancing age. This begs the question as to whether Mg could be used as biomarker of aging. A biomarker of aging is a biological parameter of an organism that, in the absence of disease, better predicts functional capability at a later age than the chronological age. Bone and muscle Mg content might be useful biomarkers, but the need for biopsies and the heterogeneous distribution of Mg in bones and muscles strongly limit the application of these methods in clinical practice. Similar considerations can be made for urinary Mg assessment, particularly after a loading test. Markers of Mg in blood seem fairly unreliable as biomarkers of aging since they are strongly dependent upon renal function, do not reflect the intracellular Mg status, and, in some investigations, are within normal ranges although other Mg parameters are not. Other investigations (e.g. nuclear magnetic resonance with fluorescent probes) seem to be promising, but their availability remains limited.

  4. Estimating Groundwater-Age Distributions Contributing to Streams in the Fractured-Rock Terrain of the Upper Potomac River Basin, USA (Invited)

    NASA Astrophysics Data System (ADS)

    Sanford, W. E.; Fleming, B.; Pope, J.

    2013-12-01

    Base flow to individual streams has discharging groundwater with ages that vary widely between values of days to centuries or more. This distribution of ages has important repercussions for the response time of a watershed between change in land-use practices and the discharge of contaminants, such as nitrogen, to streams or coastal waterways. Lumped parameter models are frequently used to predict such watershed responses in shallow aquifers, but these usually assume homogeneous hydraulic properties. In the Chesapeake Bay watershed, however, over half of the terrain is underlain by fractured-rock, where heterogeneous hydraulic properties do not fit standard lumped-parameter model assumptions. In order to better understand the response behavior of a regional fractured-rock terrain, we developed a seven-million node, three-dimensional groundwater model of the Upper Potomac River Basin (~24,000 sq. km) using MODFLOW that includes siliciclastic, carbonate, and metamorphic rocks. Inverse modeling was undertaken to estimate regional values of hydraulic conductivity (K) using 200 water-level measurements in wells, and effective porosity using >100 environmental tracer (CFC-113, SF6, 3H, 3He) measurements from wells, springs and the Potomac River at the basin outlet. Results indicate a very strong depth-dependence of K, with values declining by 4-6 orders of magnitude within 100 m of land surface, with the bulk of the transmissivity being focused in the upper 10 m. This depth-dependent behavior has major implications for the watershed response time, as the base flows have ages that range over four orders of magnitude, as opposed to a shallow homogenous aquifer that usually has an equivalent range of less than two orders of magnitude. A tritium record from 1961-1991 in the Potomac River at the basin outflow can be reproduced by the model using advective transport and a single regional porosity value of 2-3 percent. In addition, the fit to the data can be improved at early

  5. Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 2: Crater Size-frequency Distribution Curves and Geomorphic Unit Ages

    NASA Technical Reports Server (NTRS)

    Parker, T. J.; Pieri, D. C.

    1985-01-01

    In assessing the relative ages of the geomorphic/geologic units, crater counts of the entire unit or nearly the entire unit were made and summed in order to get a more accurate value than obtainable by counts of isolated sections of each unit. Cumulative size-frequency counts show some interesting relationships. Most of the units show two distinct crater populations with a flattening out of the distribution curve at and below 10 km diameter craters. Above this crater size the curves for the different units diverge most notably. In general, the variance may reflect the relative ages of these units. At times, however, in the larger crater size range, these curves can overlap and cross on another. Also the error bars at these larger sizes are broader (and thus more suspect), since counts of larger craters show more scatter, whereas the unit areas remain constant. Occasional clusters of relatively large craters within a given unit, particularly one of limited areal extent, can affect the curve so that the unit might seem to be older than units which it overlies or cuts.

  6. Efficacy of various chiropractic treatments, age distribution and incidence of accident- and nonaccident-caused low back pain in male and female patients.

    PubMed

    Sheladia, V L; Johnston, D A

    1986-12-01

    From a total pool of 1189 male and female patients with accident- (AC) and nonaccident- (NA) caused low back pain, 465 cases with completed therapy were studied for effectiveness of various chiropractic treatments. For those who completed therapy, the age distribution and incidence of this disorder were also studied. At the completion of the therapy, the response was evaluated as very good (pain-free, cured), better (very small degree of discomfort), relief (some reduction in pain) or no response to the treatment. The females with NA responded better than AC cases (p less than .001). However, male NA cases showed an increase in "no relief," but it was not significant (p = 0.052). The response of male AC cases was better than that of female AC cases (p less than 0.001). The cervical, thoracic, lumbar and ilium adjustment levels in female and male NA did not show any differences in response (p = 0.15, female; p = 0.46, male). The incidence of NA back pain disorders in both male and female was higher as compared to AC-caused back problems (p less than 0.001). The lower back pain problems did not show any age-specific association in either sex. Manipulative approaches in addition to nonmanipulative methods are superior to nonmanipulative measures alone, and females responded better to nonmanipulative care than did males.

  7. Application Of A Dynamic Model to Assess Geomorphic and Hydrologic Controls on Age-0 Colorado Pikeminnow Distribution in the Green River, Colorado And Utah

    NASA Astrophysics Data System (ADS)

    Schmidt, J. C.

    2005-05-01

    Analysis of field data and development and application of a dynamic model indicate that water releases from Flaming Gorge Dam have a large potential effect on larval drift and distribution of age-0 Colorado pikeminnow (Ptychocheilus lucius) in the middle Green River. The model predicts that high releases at the time of drift greatly increase the proportion of the population transported beyond the study area to unfavorable river environments. The model also predicts that channel simplification caused by flow regulation results in a more even longitudinal distribution of larval fish habitat. Colorado pikeminnow are a federally endangered species endemic to the Colorado River basin that utilize backwaters during their larval stage. The present agency-mandated field-sampling program for backwater habitats is probably inadequate, because it takes place at a time when the model predicts that most larval fish have drifted beyond the study area. Development of the model shows that the role of the geomorphic and hydraulic attributes that control larval drift and transport into backwaters, and that were parameterized in the model, are not well known.

  8. Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration

    USGS Publications Warehouse

    Flinn, Jane M; Kakalec, Peter; Tappero, Ryan; Jones, Blair F.; Lengyel, Imre

    2014-01-01

    Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.

  9. The Age and Qualifications of Special Education Staff in Australia

    ERIC Educational Resources Information Center

    Thomas, Tony

    2009-01-01

    This article reports on the results of a survey distributed in April 2007 to government special education schools and settings throughout Australia. The survey collected information about the age and special education qualifications of teaching staff. It followed a similar survey that was distributed in May 2006 to Victorian special schools that…

  10. Self-similarity in active colloid motion

    NASA Astrophysics Data System (ADS)

    Constant, Colin; Sukhov, Sergey; Dogariu, Aristide

    The self-similarity of displacements among randomly evolving systems has been used to describe the foraging patterns of animals and predict the growth of financial systems. At micron scales, the motion of colloidal particles can be analyzed by sampling their spatial displacement in time. For self-similar systems in equilibrium, the mean squared displacement increases linearly in time. However, external forces can take the system out of equilibrium, creating active colloidal systems, and making this evolution more complex. A moment scaling spectrum of the distribution of particle displacements quantifies the degree of self-similarity in the colloid motion. We will demonstrate that, by varying the temporal and spatial characteristics of the external forces, one can control the degree of self-similarity in active colloid motion.

  11. Trends and spatial distribution of deaths of children aged 12-60 months in São Paulo, Brazil, 1980-98.

    PubMed Central

    Antunes, José Leopoldo Ferreira; Waldman, Eliseu Alves

    2002-01-01

    OBJECTIVE: To describe trends in the mortality of children aged 12-60 months and to perform spatial data analysis of its distribution at the inner city district level in São Paulo from 1980 to 1998. METHODS: Official mortality data were analysed in relation to the underlying causes of death. The population of children aged 12-60 months, disaggregated by sex and age, was estimated for each year. Educational levels, income, employment status, and other socioeconomic indices were also assessed. Statistical Package for Social Sciences software was used for the statistical processing of time series. The Cochrane-Orcutt procedure of generalized least squares regression analysis was used to estimate the regression parameters with control of first-order autocorrelation. Spatial data analysis employed the discrimination of death rates and socioeconomic indices at the inner city district level. For classifying area-level death rates the method of K-means cluster analysis was used. Spatial correlation between variables was analysed by the simultaneous autoregressive regression method. FINDINGS: There was a steady decline in death rates during the 1980s at an average rate of 3.08% per year, followed by a levelling off. Infectious diseases remained the major cause of mortality, accounting for 43.1% of deaths during the last three years of the study. Injuries accounted for 16.5% of deaths. Mortality rates at the area level clearly demonstrated inequity in the city's health profile: there was an increasing difference between the rich and the underprivileged social strata in this respect. CONCLUSION: The overall mortality rate among children aged 12-60 months dropped by almost 30% during the study period. Most of the decline happened during the 1980s. Many people still live in a state of deprivation in underserved areas. Time-series and spatial data analysis provided indications of potential value in the planning of social policies promoting well-being, through the identification

  12. Effectiveness of community-based complementary food supplement (Yingyangbao) distribution in children aged 6-23 months in poor areas in China

    PubMed Central

    Zhao, Liyun; Yu, Wentao; Zhang, Jian; Man, Qingqing; He, Li; Duan, Yifan; Wang, Hui; Scherpbier, Robert; Yin, Shi-an

    2017-01-01

    Background Poor growth and micronutrient deficiency mainly attack older infants and young children. Some countries have adopted clinically effective measures to combat malnutrition, but the compliance and improvement in efficacy of intervention vehicles in national programs require evaluation. Methods Baseline and follow-up cross-sectional surveys were conducted before and after a nutrition intervention program in 3 national poverty counties in China. Soybean-based complementary food supplements called Yingyangbao (YYB) in Chinese and training materials on child feeding were distributed to households with children aged 6–23 months for 18 months. Representative children were selected by probability proportional to size sampling methods to assess compliance of YYB and the intervention efficacy. A questionnaire was designed to collect data on basic characteristics of children, breastfeeding, 24-hour dietary intake, and consumption and appetite of YYB. Anthropometrics and hemoglobin were measured in the field, and anemia prevalence was evaluated. Venous blood was drawn from children aged 12–35 months to evaluate micronutrient status. Logistic regression was used to identify the risk factors for children’s anemia. Results Of the children involved in the follow-up survey (n = 693), the P50 (P25, P75) intake of YYB was 6.7 (3.5, 7.0) sachets weekly, and 54.7% of the children liked the taste of YYB. Compared with the baseline situation (n = 823), the proportion of children fed a diverse diet and foods rich in iron or vitamin A increased (P < 0.01) in the follow-up study. The prevalence of stunting and underweight decreased (P < 0.05), the prevalence of anemia decreased from 28.0% to 19.9% (P < 0.01), and the prevalence of vitamin B12 deficiency decreased from 26.8% to 15.4% (P < 0.01). For children aged 12–23 months, those who liked YYB and consumed 6 or more sachets of YYB weekly were at lower risk for anemia (OR = 0.34, 95% CI 0.13–0.90, P < 0.05), but the risk

  13. Heterogeneous ageing of skeletal muscle microvascular function.

    PubMed

    Muller-Delp, Judy M

    2016-04-15

    The distribution of blood flow to skeletal muscle during exercise is altered with advancing age. Changes in arteriolar function that are muscle specific underlie age-induced changes in blood flow distribution. With advancing age, functional adaptations that occur in resistance arterioles from oxidative muscles differ from those that occur in glycolytic muscles. Age-related adaptations of morphology, as well as changes in both endothelial and vascular smooth muscle signalling, differ in muscle of diverse fibre type. Age-induced endothelial dysfunction has been reported in most skeletal muscle arterioles; however, unique alterations in signalling contribute to the dysfunction in arterioles from oxidative muscles as compared with those from glycolytic muscles. In resistance arterioles from oxidative muscle, loss of nitric oxide signalling contributes significantly to endothelial dysfunction, whereas in resistance arterioles from glycolytic muscle, alterations in both nitric oxide and prostanoid signalling underlie endothelial dysfunction. Similarly, adaptations of the vascular smooth muscle that occur with advancing age are heterogeneous between arterioles from oxidative and glycolytic muscles. In both oxidative and glycolytic muscle, late-life exercise training reverses age-related microvascular dysfunction, and exercise training appears to be particularly effective in reversing endothelial dysfunction. Patterns of microvascular ageing that develop among muscles of diverse fibre type and function may be attributable to changing patterns of physical activity with ageing. Importantly, aerobic exercise training, initiated even at an advanced age, restores muscle blood flow distribution patterns and vascular function in old animals to those seen in their young counterparts.

  14. Learning similarity with multikernel method.

    PubMed

    Tang, Yi; Li, Luoqing; Li, Xuelong

    2011-02-01

    In the field of machine learning, it is a key issue to learn and represent similarity. This paper focuses on the problem of learning similarity with a multikernel method. Motivated by geometric intuition and computability, similarity between patterns is proposed to be measured by their included angle in a kernel-induced Hilbert space. Having noticed that the cosine of such an included angle can be represented by a normalized kernel, it can be said that the task of learning similarity is equivalent to learning an appropriate normalized kernel. In addition, an error bound is also established for learning similarity with the multikernel method. Based on this bound, a boosting-style algorithm is developed. The preliminary experiments validate the effectiveness of the algorithm for learning similarity.

  15. Genome-wide analysis of copy number variations reveals that aging processes influence body fat distribution in Korea Associated Resource (KARE) cohorts.

    PubMed

    Lee, Bo-Young; Shin, Dong Hyun; Cho, Seoae; Seo, Kang-Seok; Kim, Heebal

    2012-11-01

    Many anthropometric measures, including body mass index (BMI), waist-to-hip ratio (WHR), and subcutaneous fat thickness, are used as indicators of nutritional status, fertility and predictors of future health outcomes. While BMI is currently the best available estimate of body adiposity, WHR and skinfold thickness at various sites (biceps, triceps, suprailiac, and subscapular) are used as indices of body fat distribution. Copy number variation (CNV) is an attractive emerging approach to the study of associations with various diseases. In this study, we investigated the dosage effect of genes in the CNV genome widely associated with fat distribution phenotypes in large cohorts. We used the Affymetrix genome-wide human SNP Array 5.0 data of 8,842 healthy unrelated adults in KARE cohorts and identified CNVs associated with BMI and fat distribution-related traits including WHR and subcutaneous skinfold thickness at suprailiac (SUP) and subscapular (SUB) sites. CNV segmentation of each chromosome was performed using Golden Helix SVS 7.0, and single regression analysis was used to identify CNVs associated with each phenotype. We found one CNV for BMI, 287 for WHR, 2,157 for SUP, and 2,102 for SUB at the 5% significance level after Holm-Bonferroni correction. Genes included in the CNV were used for the analysis of functional annotations using the Database for Annotation, Visualization and Integrated Discovery (DAVID v6.7b) tool. Functional gene classification analysis identified five significant gene clusters (metallothionein, ATP-binding proteins, ribosomal proteins, kinesin family members, and zinc finger proteins) for SUP, three (keratin-associated proteins, zinc finger proteins, keratins) for SUB, and one (protamines) for WHR. BMI was excluded from this analysis because the entire structure of no gene was identified in the CNV. Based on the analysis of genes enriched in the clusters, the fat distribution traits of KARE cohorts were related to the fat redistribution

  16. Similarity Learning of Manifold Data.

    PubMed

    Chen, Si-Bao; Ding, Chris H Q; Luo, Bin

    2015-09-01

    Without constructing adjacency graph for neighborhood, we propose a method to learn similarity among sample points of manifold in Laplacian embedding (LE) based on adding constraints of linear reconstruction and least absolute shrinkage and selection operator type minimization. Two algorithms and corresponding analyses are presented to learn similarity for mix-signed and nonnegative data respectively. The similarity learning method is further extended to kernel spaces. The experiments on both synthetic and real world benchmark data sets demonstrate that the proposed LE with new similarity has better visualization and achieves higher accuracy in classification.

  17. Aging gauge

    DOEpatents

    Betts, Robert E.; Crawford, John F.

    1989-01-01

    An aging gauge comprising a container having a fixed or a variable sized t opening with a cap which can be opened to control the sublimation rate of a thermally sublimational material contained within the container. In use, the aging gauge is stored with an item to determine total heat the item is subjected to and also the maximum temperature to which the item has been exposed. The aging gauge container contains a thermally sublimational material such as naphthalene or similar material which has a low sublimation rate over the temperature range from about 70.degree. F. to about 160.degree. F. The aging products determined by analyses of a like item aged along with the aging gauge for which the sublimation amount is determined is employed to establish a calibration curve for future aging evaluation. The aging gauge is provided with a means for determining the maximum temperature exposure (i.e., a thermally indicating material which gives an irreversible color change, Thermocolor pigment). Because of the relationship of doubling reaction rates for increases of 10.degree. C., equivalency of item used in accelerated aging evaluation can be obtained by referring to a calibration curve depicting storage temperature on the abscissa scale and multiplier on the ordinate scale.

  18. Aging gauge

    DOEpatents

    Betts, Robert E.; Crawford, John F.

    1989-04-04

    An aging gauge comprising a container having a fixed or a variable sized t opening with a cap which can be opened to control the sublimation rate of a thermally sublimational material contained within the container. In use, the aging gauge is stored with an item to determine total heat the item is subjected to and also the maximum temperature to which the item has been exposed. The aging gauge container contains a thermally sublimational material such as naphthalene or similar material which has a low sublimation rate over the temperature range from about 70.degree. F. to about 160.degree. F. The aging products determined by analyses of a like item aged along with the aging gauge for which the sublimation amount is determined is employed to establish a calibration curve for future aging evaluation. The aging gauge is provided with a means for determining the maximum temperature exposure (i.e., a thermally indicating material which gives an irreversible color change, Thermocolor pigment). Because of the relationship of doubling reaction rates for increases of 10.degree. C., equivalency of item used in accelerated aging evaluation can be obtained by referring to a calibration curve depicting storage temperature on the abscissa scale and multiplier on the ordinate scale.

  19. Age and sex distribution of Dirofilaria immitis among dogs in Meshkin-Shahr, northwest Iran and molecular analysis of the isolates based on COX1 gene

    PubMed Central

    Zarei, Zabiholah; Kia, Eshrat Beigom; Heidari, Zahra; Mikaeili, Fattaneh; Mohebali, Mehdi; Sharifdini, Meysam

    2016-01-01

    Dirofilaria immitis is an important filarial nematode in dogs. In this study, age and sex distribution of this zoonotic nematode among dogs were investigated in northwest of Iran in Meshkin-Shahr city. Molecular characteristics of the isolates, based on cytochrome oxidase subunit 1 (COX1) gene were compared to the isolates from other areas of the world.Blood samples were collected from 91 dogs which were selected by simple classified accidental sampling. Thin and thick blood smear examinations were used to find out infectivity with D. immitis. DNA extraction was performed from adult D. immitis recovered from heart of infected dogs. The COX1 gene was amplified and sequenced. Phylogenetic analysis was carried out using sequences obtained in this study along with relevant sequences deposited in the GenBank. Phylogenetic analysis and sequence variation was performed using MEGA software in comparison with those COX1 sequences deposited in GenBank. Out of 91 dogs, 19 (20.87%) were found positive for infection with D. immitis. There was no statistically significant difference between males and females of dogs in terms of D. immitis infection. However, the rate of infection in dogs more than 2 years old was significantly higher than those with lower age. Both sequences analyzed in this study showed 100% homology to each other. Intra-species variation of these isolates with those from other areas of the world amounted to 0 to 0.50%. Phylogenetic analysis of the COX1 gene suggested that it is conserved, and can be used for study on genetic diversity and classification of filarial nematodes. PMID:28144425

  20. Relative risk of Alzheimer disease and age-at-onset distributions, based on APOE genotypes among elderly African Americans, caucasians, and hispanics in New York City

    SciTech Connect

    Tang, M.X.; Liu, X.H.; Stern, Y.

    1996-03-01

    Apolipoprotein-E {epsilon}4 (APOE-{epsilon}4) has been consistently associated with Alzheimer disease (AD) and may be responsible for an earlier age at onset. We have previously reported a diminished association between APOE-{epsilon}4 and AD in African Americans. Using a new method, which allows inclusion of censored information, we compared relative risks by APOE genotypes in an expanded collection of cases and controls from three ethnic groups in a New York community. The relative risk for AD associated with APOE-{epsilon}4 homozygosity was increased in all ethnic groups (African American relative risk [RR] = 3.0; 95% confidence interval [CI] = 1.5-5.9; Caucasian RR = 7.3, 95% CI = 2.5-21.6; and Hispanic RR = 2.5, 95% CI = 1.1-5.7), compared with those with APOE-{epsilon}3/{epsilon}3 genotypes. The risk was also increased for APOE-{epsilon}4 heterozygous Caucasians (RR = 2.9, 95% CI = 1.7-5.1) and Hispanics (RR = 1.6,95% CI = 1.1-2.3), but not for African Americans (RR = 0.6, 95% CI = 0.4-0.9). The age distribution of the proportion of Caucasians and Hispanics without AD was consistently lower for APOE-{epsilon}4 homozygous and APOE-{epsilon}4 heterozygous individuals than for those with other APOE genotypes. In African Americans this relationship was observed only in APOE-{epsilon}4 homozygotes. These results confirm that APOE genotypes influence the RR of AD in Caucasians and Hispanics. Differences in risk among APOE-{epsilon}4 heterozygote African Americans suggest that other genetic or environmental factors may modify the effect of APOE-{epsilon}4 in some populations. 58 refs., 3 figs., 4 tabs.

  1. Influence of alternating soil drying and wetting on the desorption and distribution of aged 14C-labeled pesticide residues in soil organic fractions

    NASA Astrophysics Data System (ADS)

    Jablonowski, N. D.; Mucha, M.; Thiele, B.; Hofmann, D.; Burauel, P.

    2012-04-01

    A laboratory experiment was conducted to evaluate the effect of alternating soil drying and wetting on the release of aged 14C-labeled pesticide residues and their distribution in soil organic fractions (humic acids, fulvic acids, and humin substances). The used soils (gleyic cambisol; Corg 1.2%, pH 7.2) were obtained from the upper soil layer of two individual outdoor lysimeter studies containing either environmentally long-term aged 14C residues of the herbicide ethidimuron (ETD; 0-10 cm depth; time of aging: 9 years) or methabenzthiazuron (MBT; 0-30 cm depth; time of aging: 17 years). Triplicate soil samples (10 g dry soil equivalents) were (A=dry/wet) previously dried (45° C) or (B=wet/wet) directly mixed with pure water (1+2, w:w), shaken (150 rpm, 1 h), and centrifuged (~2000 g). The resulting supernatant was removed, filtered (0.45 μm) and subjected to 14C activity analysis via liquid scintillation counter (LSC), dissolved organic carbon (DOC) analysis, and LC-MS-MS analysis. This extraction procedure was repeated 15 individual times, for both setups (A) and (B). To determine the distribution of the aged 14C labelled pesticide residues in the soil organic matter fractions, the soil samples were subject to humic and fulvic acids fractionations at cycles 0, 4, 10, and 15. The residual pesticide 14C activity associated with the humic, fulvic, and humin substances (organic fraction remaining in the soil) fractions was determined via LSC. The water-extracted residual 14C activity was significantly higher in the extracts of the dry/wet, compared to the wet/wet soil samples for both pesticides. The total extracted 14C activity in the dry/wet soil extracts accounted for 51.0% (ETD) and 15.4% (MBT) in contrast to 19.0% (ETD) and 4.7% (MBT) in the wet/wet extracts after 15 water extractions. LC-MS-MS analysis revealed the parent compound ETD 27.9 μg kg-1 soil (dry/wet) and 10.7 μg kg-1 soil (wet/wet), accounting for 3.45 and 1.35% of total parent compound

  2. Discuss Similarity Using Visual Intuition

    ERIC Educational Resources Information Center

    Cox, Dana C.; Lo, Jane-Jane

    2012-01-01

    The change in size from a smaller shape to a larger similar shape (or vice versa) is created through continuous proportional stretching or shrinking in every direction. Students cannot solve similarity tasks simply by iterating or partitioning a composed unit, strategies typically used on numerical proportional tasks. The transition to thinking…

  3. Dynamic similarity in erosional processes

    USGS Publications Warehouse

    Scheidegger, A.E.

    1963-01-01

    A study is made of the dynamic similarity conditions obtaining in a variety of erosional processes. The pertinent equations for each type of process are written in dimensionless form; the similarity conditions can then easily be deduced. The processes treated are: raindrop action, slope evolution and river erosion. ?? 1963 Istituto Geofisico Italiano.

  4. Anal human papillomavirus genotype distribution in HIV-infected men who have sex with men by geographical origin, age, and cytological status in a Spanish cohort.

    PubMed

    Torres, Montserrat; González, Cristina; del Romero, Jorge; Viciana, Pompeyo; Ocampo, Antonio; Rodríguez-Fortúnez, Patricia; Masiá, Mar; Blanco, José Ramón; Portilla, Joaquín; Rodríguez, Carmen; Hernández-Novoa, Beatriz; del Amo, Julia; Ortiz, Marta

    2013-11-01

    Knowledge of human papillomavirus (HPV) type distribution in populations at risk for anal cancer is needed. Here, we describe the anal HPV genotype distribution in a large Spanish cohort (Cohort of the Spanish HIV Research Network HPV [CoRIS-HPV]) of HIV-positive men who have sex with men (MSM) according to geographical origin, age, and cytological status. A cross-sectional analysis of baseline data from 1,439 HIV-infected MSM (2007 to 2012) was performed. Anal HPV genotyping was performed using the Linear Array HPV genotyping test. Descriptive analyses of subject characteristics, prevalences, and 95% confidence intervals (CI) were performed. The global prevalences of HPV, high-risk HPV (HR-HPV), and low-risk HPV (LR-HPV) types were 95.8%, 83.0%, and 72.7%, respectively. Among the HR-HPV types, HPV16 was the most common, followed by HPV59, -39, -51, -18, and -52. The prevalence of multiple HR-HPV infections was 58.5%. There were no differences in the crude analyses between Spanish and Latin-American MSM for most HPV types, and a peak in prevalence for most HPV types was seen in patients in their late thirties. Globally and by specific HPV groups, men with abnormal anal cytologies had a higher prevalence of infection than those with normal cytologies. This study has the largest number of HIV-positive MSM with HPV genotype data analyzed according to cytological status as far as we know. The information gained from this study can help with the design of anal cancer prevention strategies in HIV-positive patients.

  5. Anal Human Papillomavirus Genotype Distribution in HIV-Infected Men Who Have Sex with Men by Geographical Origin, Age, and Cytological Status in a Spanish Cohort

    PubMed Central

    Torres, Montserrat; González, Cristina; del Romero, Jorge; Viciana, Pompeyo; Ocampo, Antonio; Rodríguez-Fortúnez, Patricia; Masiá, Mar; Blanco, José Ramón; Portilla, Joaquín; Rodríguez, Carmen; Hernández-Novoa, Beatriz; del Amo, Julia

    2013-01-01

    Knowledge of human papillomavirus (HPV) type distribution in populations at risk for anal cancer is needed. Here, we describe the anal HPV genotype distribution in a large Spanish cohort (Cohort of the Spanish HIV Research Network HPV [CoRIS-HPV]) of HIV-positive men who have sex with men (MSM) according to geographical origin, age, and cytological status. A cross-sectional analysis of baseline data from 1,439 HIV-infected MSM (2007 to 2012) was performed. Anal HPV genotyping was performed using the Linear Array HPV genotyping test. Descriptive analyses of subject characteristics, prevalences, and 95% confidence intervals (CI) were performed. The global prevalences of HPV, high-risk HPV (HR-HPV), and low-risk HPV (LR-HPV) types were 95.8%, 83.0%, and 72.7%, respectively. Among the HR-HPV types, HPV16 was the most common, followed by HPV59, -39, -51, -18, and -52. The prevalence of multiple HR-HPV infections was 58.5%. There were no differences in the crude analyses between Spanish and Latin-American MSM for most HPV types, and a peak in prevalence for most HPV types was seen in patients in their late thirties. Globally and by specific HPV groups, men with abnormal anal cytologies had a higher prevalence of infection than those with normal cytologies. This study has the largest number of HIV-positive MSM with HPV genotype data analyzed according to cytological status as far as we know. The information gained from this study can help with the design of anal cancer prevention strategies in HIV-positive patients. PMID:23966501

  6. Towards personalized medicine: leveraging patient similarity and drug similarity analytics.

    PubMed

    Zhang, Ping; Wang, Fei; Hu, Jianying; Sorrentino, Robert

    2014-01-01

    The rapid adoption of electronic health records (EHR) provides a comprehensive source for exploratory and predictive analytic to support clinical decision-making. In this paper, we investigate how to utilize EHR to tailor treatments to individual patients based on their likelihood to respond to a therapy. We construct a heterogeneous graph which includes two domains (patients and drugs) and encodes three relationships (patient similarity, drug similarity, and patient-drug prior associations). We describe a novel approach for performing a label propagation procedure to spread the label information representing the effectiveness of different drugs for different patients over this heterogeneous graph. The proposed method has been applied on a real-world EHR dataset to help identify personalized treatments for hypercholesterolemia. The experimental results demonstrate the effectiveness of the approach and suggest that the combination of appropriate patient similarity and drug similarity analytics could lead to actionable insights for personalized medicine. Particularly, by leveraging drug similarity in combination with patient similarity, our method could perform well even on new or rarely used drugs for which there are few records of known past performance.

  7. Self-similar scalar field collapse

    NASA Astrophysics Data System (ADS)

    Banerjee, Narayan; Chakrabarti, Soumya

    2017-01-01

    A spherically symmetric collapsing scalar field model is discussed with a dissipative fluid which includes a heat flux. This vastly general matter distribution is analyzed at the expense of a high degree of symmetry in the space-time, that of conformal flatness and self-similarity. Indeed collapsing models terminating into a curvature singularity can be obtained. The formation of black holes or the occurrence of naked singularities depends on the initial collapsing profiles.

  8. Age distribution of Ocean Drill sites across the Central Walvis Ridge indicates plate boundary control of plume volcanism in the South Atlantic

    NASA Astrophysics Data System (ADS)

    O'Connor, John M.; Jokat, Wilfried

    2015-08-01

    The Tristan-Gough hotspot trail on the African plate consists of the Walvis Ridge and a younger province of seamounts and islands. In order to determine the relative motion between the African plate and the Tristan-Gough hotspot it is essential to resolve changes in the age and morphology of the Walvis Ridge. A significant problem is, however, to establish how the vigor and flow of hotspot material to the mid-ocean ridge constructed the Walvis Ridge. We have addressed this issue by measuring an 40Ar/39Ar stratigraphy at three sites across the central Walvis Ridge sampled by Ocean Drilling (DSDP Leg 74). The age-distance relation of volcanism, together with geophysical, geochemical and paleodepth information, suggests collectively that hotspot volcanism was occurring locally c. 72 Ma on an elevated segment of the mid-ocean ridge located close to the Tristan-Gough hotspot. As the mid-ocean ridge migrated away from the hotspot (c. 36 km/Ma) between c. 72 Ma and 68 Ma, hotspot material continued flowing to the mid-ocean ridge and the Walvis Ridge shoaled rapidly (c. 500 m/Ma) to the west, on seafloor that might have been subsiding at a rate consistent with normal crustal cooling. This apparent correlation points to the possibility of an inverse relation between the volume flux of hotspot volcanism and the distance between the mid-ocean ridge and the Tristan-Gough hotspot. We infer that since c. 93 Ma the geometry and motion of the mid-ocean ridge determined where the hotspot material that built the Walvis Ridge was channeled to the plate surface. Furthermore, interplay between hotspot flow, and the changing geometry of the mid-ocean ridge as it migrated relative to the Tristan-Gough hotspot, might explain the age and morphology of the Walvis Ridge. Our finding provides further evidence that the distribution of hotspot volcanism in the southeast Atlantic expresses interaction between deep mantle (plume) and shallow plate tectonic and asthenosphere processes.

  9. THE LUMINOSITY, MASS, AND AGE DISTRIBUTIONS OF COMPACT STAR CLUSTERS IN M83 BASED ON HUBBLE SPACE TELESCOPE/WIDE FIELD CAMERA 3 OBSERVATIONS

    SciTech Connect

    Chandar, Rupali; Whitmore, Bradley C.; Mutchler, Max; Bond, Howard; Kim, Hwihyun; Kaleida, Catherine; Calzetti, Daniela; Saha, Abhijit; O'Connell, Robert; Balick, Bruce; Carollo, Marcella; Disney, Michael; Dopita, Michael A.; Frogel, Jay A.; Hall, Donald; Holtzman, Jon A.; Kimble, Randy A.; McCarthy, Patrick; Paresce, Francesco; Silk, Joe

    2010-08-10

    The newly installed Wide Field Camera 3 (WFC3) on the Hubble Space Telescope has been used to obtain multi-band images of the nearby spiral galaxy M83. These new observations are the deepest and highest resolution images ever taken of a grand-design spiral, particularly in the near-ultraviolet, and allow us to better differentiate compact star clusters from individual stars and to measure the luminosities of even faint clusters in the U band. We find that the luminosity function (LF) for clusters outside of the very crowded starburst nucleus can be approximated by a power law, dN/dL {proportional_to} L {sup {alpha}}, with {alpha} = -2.04 {+-} 0.08, down to M{sub V} {approx} -5.5. We test the sensitivity of the LF to different selection techniques, filters, binning, and aperture correction determinations, and find that none of these contribute significantly to uncertainties in {alpha}. We estimate ages and masses for the clusters by comparing their measured UBVI, H{alpha} colors with predictions from single stellar population models. The age distribution of the clusters can be approximated by a power law, dN/d{tau} {proportional_to} {tau}{sup {gamma}}, with {gamma} = -0.9 {+-} 0.2, for M {approx}> few x 10{sup 3} M {sub sun} and {tau} {approx}< 4 x 10{sup 8} yr. This indicates that clusters are disrupted quickly, with {approx}80%-90% disrupted each decade in age over this time. The mass function of clusters over the same M-{tau} range is a power law, dN/dM {proportional_to} M {sup {beta}}, with {beta} = -1.94 {+-} 0.16, and does not have bends or show curvature at either high or low masses. Therefore, we do not find evidence for a physical upper mass limit, M{sub C} , or for the earlier disruption of lower mass clusters when compared with higher mass clusters, i.e., mass-dependent disruption. We briefly discuss these implications for the formation and disruption of the clusters.

  10. Does language about similarity play a role in fostering similarity comparison in children?

    PubMed

    Ozçalişkan, Seyda; Goldin-Meadow, Susan; Gentner, Dedre; Mylander, Carolyn

    2009-08-01

    Commenting on perceptual similarities between objects stands out as an important linguistic achievement, one that may pave the way towards noticing and commenting on more abstract relational commonalities between objects. To explore whether having a conventional linguistic system is necessary for children to comment on different types of similarity comparisons, we observed four children who had not been exposed to usable linguistic input--deaf children whose hearing losses prevented them from learning spoken language and whose hearing parents had not exposed them to sign language. These children developed gesture systems that have language-like structure at many different levels. Here we ask whether the deaf children used their gestures to comment on similarity relations and, if so, which types of relations they expressed. We found that all four deaf children were able to use their gestures to express similarity comparisons (point to cat+point to tiger) resembling those conveyed by 40 hearing children in early gesture+speech combinations (cat+point to tiger). However, the two groups diverged at later ages. Hearing children, after acquiring the word like, shifted from primarily expressing global similarity (as in cat/tiger) to primarily expressing single-property similarity (as in crayon is brown like my hair). In contrast, the deaf children, lacking an explicit term for similarity, continued to primarily express global similarity. The findings underscore the robustness of similarity comparisons in human communication, but also highlight the importance of conventional terms for comparison as likely contributors to routinely expressing more focused similarity relations.

  11. Renewing the respect for similarity.

    PubMed

    Edelman, Shimon; Shahbazi, Reza

    2012-01-01

    In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemming from its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problem at hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, by surveying established results and new developments in the theory and methods of similarity-preserving associative lookup and dimensionality reduction-critical components of many cognitive functions, as well as of intelligent data management in computer vision. We focus in particular on the growing family of algorithms that support associative memory by performing hashing that respects local similarity, and on the uses of similarity in representing structured objects and scenes. Insofar as these similarity-based ideas and methods are useful in cognitive modeling and in AI applications, they should be included in the core conceptual toolkit of computational neuroscience. In support of this stance, the present paper (1) offers a discussion of conceptual, mathematical, computational, and empirical aspects of similarity, as applied to the problems of visual object and scene representation, recognition, and interpretation, (2) mentions some key computational problems arising in attempts to put similarity to use, along with their possible solutions, (3) briefly states a previously developed similarity-based framework for visual object representation, the Chorus of Prototypes, along with the empirical support it enjoys, (4) presents new mathematical insights into the effectiveness of this framework, derived from its relationship to locality-sensitive hashing (LSH) and to concomitant statistics, (5) introduces a new model, the Chorus of Relational Descriptors (ChoRD), that extends this framework to scene representation and interpretation, (6) describes its implementation and testing, and finally (7) suggests possible directions in which the present research program can be

  12. Renewing the respect for similarity

    PubMed Central

    Edelman, Shimon; Shahbazi, Reza

    2012-01-01

    In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemming from its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problem at hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, by surveying established results and new developments in the theory and methods of similarity-preserving associative lookup and dimensionality reduction—critical components of many cognitive functions, as well as of intelligent data management in computer vision. We focus in particular on the growing family of algorithms that support associative memory by performing hashing that respects local similarity, and on the uses of similarity in representing structured objects and scenes. Insofar as these similarity-based ideas and methods are useful in cognitive modeling and in AI applications, they should be included in the core conceptual toolkit of computational neuroscience. In support of this stance, the present paper (1) offers a discussion of conceptual, mathematical, computational, and empirical aspects of similarity, as applied to the problems of visual object and scene representation, recognition, and interpretation, (2) mentions some key computational problems arising in attempts to put similarity to use, along with their possible solutions, (3) briefly states a previously developed similarity-based framework for visual object representation, the Chorus of Prototypes, along with the empirical support it enjoys, (4) presents new mathematical insights into the effectiveness of this framework, derived from its relationship to locality-sensitive hashing (LSH) and to concomitant statistics, (5) introduces a new model, the Chorus of Relational Descriptors (ChoRD), that extends this framework to scene representation and interpretation, (6) describes its implementation and testing, and finally (7) suggests possible directions in which the present research program can be

  13. Age distributions of sea otters found dead in Prince William Sound, Alaska, following the Exxon Valdez oil spill. Marine mammal study 6-15. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Monson, D.H.; Ballachey, B.

    1995-06-01

    Age distribution of sea otters (Enhydra lutris) found dead on beaches in western Prince William Sound Alaska, from 1976 to 1984, were compared to those of sea otters found dead from 1989 to 1993, following the Exxon Valdez oil spill. The age distribution of sea otters recovered in western Prince William Sound prior to the spill was bimodal and composed of primarily young and old animals. The high proportion of prime-age otters recovered immediately following the spill indicates significant losses occurred within a segment of the population which normally experiences very low mortality. The high proportion of prime-age otters recovered in 1990-1991 may be evidence of a prolonged, spill-related effect on the western Prince William Sound sea otter population.

  14. Predicting spatial similarity of freshwater fish biodiversity

    PubMed Central

    Azaele, Sandro; Muneepeerakul, Rachata; Maritan, Amos; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

    2009-01-01

    A major issue in modern ecology is to understand how ecological complexity at broad scales is regulated by mechanisms operating at the organismic level. What specific underlying processes are essential for a macroecological pattern to emerge? Here, we analyze the analytical predictions of a general model suitable for describing the spatial biodiversity similarity in river ecosystems, and benchmark them against the empirical occurrence data of freshwater fish species collected in the Mississippi–Missouri river system. Encapsulating immigration, emigration, and stochastic noise, and without resorting to species abundance data, the model is able to reproduce the observed probability distribution of the Jaccard similarity index at any given distance. In addition to providing an excellent agreement with the empirical data, this approach accounts for heterogeneities of different subbasins, suggesting a strong dependence of biodiversity similarity on their respective climates. Strikingly, the model can also predict the actual probability distribution of the Jaccard similarity index for any distance when considering just a relatively small sample. The proposed framework supports the notion that simplified macroecological models are capable of predicting fundamental patterns—a theme at the heart of modern community ecology. PMID:19359481

  15. Privacy-preserving matching of similar patients.

    PubMed

    Vatsalan, Dinusha; Christen, Peter

    2016-02-01

    The identification of similar entities represented by records in different databases has drawn considerable attention in many application areas, including in the health domain. One important type of entity matching application that is vital for quality healthcare analytics is the identification of similar patients, known as similar patient matching. A key component of identifying similar records is the calculation of similarity of the values in attributes (fields) between these records. Due to increasing privacy and confidentiality concerns, using the actual attribute values of patient records to identify similar records across different organizations is becoming non-trivial because the attributes in such records often contain highly sensitive information such as personal and medical details of patients. Therefore, the matching needs to be based on masked (encoded) values while being effective and efficient to allow matching of large databases. Bloom filter encoding has widely been used as an efficient masking technique for privacy-preserving matching of string and categorical values. However, no work on Bloom filter-based masking of numerical data, such as integer (e.g. age), floating point (e.g. body mass index), and modulus (numbers wrap around upon reaching a certain value, e.g. date and time), which are commonly required in the health domain, has been presented in the literature. We propose a framework with novel methods for masking numerical data using Bloom filters, thereby facilitating the calculation of similarities between records. We conduct an empirical study on publicly available real-world datasets which shows that our framework provides efficient masking and achieves similar matching accuracy compared to the matching of actual unencoded patient records.

  16. Similarity of the Velocity Profile

    DTIC Science & Technology

    2014-10-01

    su x (with 0 constantb = ) is the empirically derived velocity scale developed by Zagarola and Smits [5] for turbulent boundary layer flow...Zagarola and Smits and others have shown that the velocity scaling factor given by Eq. 5 with sδ as the boundary layer thickness can collapse certain...and Smits , it is important to point out that the fact that the similarity length scale factor and the similarity velocity scale factor must follow

  17. Distribution, diet, and energetic condition of age-0 walleye pollock (Gadus chalcogrammus) and pacific cod (Gadus macrocephalus) inhabiting the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Moss, Jamal H.; Zaleski, Marilyn F.; Heintz, Ron A.

    2016-10-01

    Walleye pollock (Gadus chalcogrammus) and Pacific cod (Gadus macrocephalus) are commercially and ecologically important species in Alaska waters. Little is known about their ecology after transitioning from larvae to free swimming fish until settlement to nursery habitats in the eastern Gulf of Alaska. Differences in the distribution, diet, body size, and energetic status between the eastern and central Gulf of Alaska were investigated during summer months to better understand regional and interspecific differences in life history and ecology. The composition of zooplankton prey in the diets of walleye pollock and Pacific cod inhabiting shelf waters was more varied relative to those inhabiting the slope and basin. Body condition and total energy content of Pacific cod was greater than walleye pollock, however total energy content increased with length at a similar rate for both species. Walleye pollock inhabiting continental slope waters had higher energy stores relative to those inhabiting the continental shelf and basin, indicating an energetic advantage for individuals remaining off the shelf during summer months or potentially the advection of fish with higher energy reserves off of the shelf. Previous studies have documented the importance of energy stores for surviving winter and future studies should focus on understanding the mechanisms influencing lipid storage and somatic growth for walleye pollock and Pacific cod inhabiting the eastern and central Gulf of Alaska.

  18. [Neuronal ageing].

    PubMed

    Piechota, Małgorzata; Sunderland, Piotr

    2014-01-01

    Ageing leads to irreversible alterations in the nervous system, which to various extent impair its functions such as capacity to learn and memory. In old neurons and brain, similarly to what may take place in other cells, there is increased oxidative stress, disturbed energetic homeostasis and metabolism, accumulation of damage in proteins and nucleic acids. Characteristic of old neurons are alterations in plasticity, synaptic transmission, sensitivity to neurotrophic factors and cytoskeletal changes. Some markers of senescence, whose one of them is SA-beta-galactosidase were used to show the process of neuronal ageing both in vitro, and in vivo. Some research suggest that, despite the fact that neurons are postmitotic cells, it is cell cycle proteins which play a certain role in their biology, e.g. differentiation. However, their role in neuronal ageing is not known or explained. Ageing is the serious factor of development of neurodegenerative diseases among others Alzheimer disease.

  19. Quantifying Similarity in Seismic Polarizations

    NASA Astrophysics Data System (ADS)

    Eaton, D. W. S.; Jones, J. P.; Caffagni, E.

    2015-12-01

    Measuring similarity in seismic attributes can help identify tremor, low S/N signals, and converted or reflected phases, in addition to diagnosing site noise and sensor misalignment in arrays. Polarization analysis is a widely accepted method for studying the orientation and directional characteristics of seismic phases via. computed attributes, but similarity is ordinarily discussed using qualitative comparisons with reference values. Here we introduce a technique for quantitative polarization similarity that uses weighted histograms computed in short, overlapping time windows, drawing on methods adapted from the image processing and computer vision literature. Our method accounts for ambiguity in azimuth and incidence angle and variations in signal-to-noise (S/N) ratio. Using records of the Mw=8.3 Sea of Okhotsk earthquake from CNSN broadband sensors in British Columbia and Yukon Territory, Canada, and vertical borehole array data from a monitoring experiment at Hoadley gas field, central Alberta, Canada, we demonstrate that our method is robust to station spacing. Discrete wavelet analysis extends polarization similarity to the time-frequency domain in a straightforward way. Because histogram distance metrics are bounded by [0 1], clustering allows empirical time-frequency separation of seismic phase arrivals on single-station three-component records. Array processing for automatic seismic phase classification may be possible using subspace clustering of polarization similarity, but efficient algorithms are required to reduce the dimensionality.

  20. What difference reveals about similarity.

    PubMed

    Sagi, Eyal; Gentner, Dedre; Lovett, Andrew

    2012-08-01

    Detecting that two images are different is faster for highly dissimilar images than for highly similar images. Paradoxically, we showed that the reverse occurs when people are asked to describe how two images differ--that is, to state a difference between two images. Following structure-mapping theory, we propose that this disassociation arises from the multistage nature of the comparison process. Detecting that two images are different can be done in the initial (local-matching) stage, but only for pairs with low overlap; thus, "different" responses are faster for low-similarity than for high-similarity pairs. In contrast, identifying a specific difference generally requires a full structural alignment of the two images, and this alignment process is faster for high-similarity pairs. We described four experiments that demonstrate this dissociation and show that the results can be simulated using the Structure-Mapping Engine. These results pose a significant challenge for nonstructural accounts of similarity comparison and suggest that structural alignment processes play a significant role in visual comparison.

  1. Earthquake detection through computationally efficient similarity search.

    PubMed

    Yoon, Clara E; O'Reilly, Ossian; Bergen, Karianne J; Beroza, Gregory C

    2015-12-01

    Seismology is experiencing rapid growth in the quantity of data, which has outpaced the development of processing algorithms. Earthquake detection-identification of seismic events in continuous data-is a fundamental operation for observational seismology. We developed an efficient method to detect earthquakes using waveform similarity that overcomes the disadvantages of existing detection methods. Our method, called Fingerprint And Similarity Thresholding (FAST), can analyze a week of continuous seismic waveform data in less than 2 hours, or 140 times faster than autocorrelation. FAST adapts a data mining algorithm, originally designed to identify similar audio clips within large databases; it first creates compact "fingerprints" of waveforms by extracting key discriminative features, then groups similar fingerprints together within a database to facilitate fast, scalable search for similar fingerprint pairs, and finally generates a list of earthquake detections. FAST detected most (21 of 24) cataloged earthquakes and 68 uncataloged earthquakes in 1 week of continuous data from a station located near the Calaveras Fault in central California, achieving detection performance comparable to that of autocorrelation, with some additional false detections. FAST is expected to realize its full potential when applied to extremely long duration data sets over a distributed network of seismic stations. The widespread application of FAST has the potential to aid in the discovery of unexpected seismic signals, improve seismic monitoring, and promote a greater understanding of a variety of earthquake processes.

  2. Earthquake detection through computationally efficient similarity search

    PubMed Central

    Yoon, Clara E.; O’Reilly, Ossian; Bergen, Karianne J.; Beroza, Gregory C.

    2015-01-01

    Seismology is experiencing rapid growth in the quantity of data, which has outpaced the development of processing algorithms. Earthquake detection—identification of seismic events in continuous data—is a fundamental operation for observational seismology. We developed an efficient method to detect earthquakes using waveform similarity that overcomes the disadvantages of existing detection methods. Our method, called Fingerprint And Similarity Thresholding (FAST), can analyze a week of continuous seismic waveform data in less than 2 hours, or 140 times faster than autocorrelation. FAST adapts a data mining algorithm, originally designed to identify similar audio clips within large databases; it first creates compact “fingerprints” of waveforms by extracting key discriminative features, then groups similar fingerprints together within a database to facilitate fast, scalable search for similar fingerprint pairs, and finally generates a list of earthquake detections. FAST detected most (21 of 24) cataloged earthquakes and 68 uncataloged earthquakes in 1 week of continuous data from a station located near the Calaveras Fault in central California, achieving detection performance comparable to that of autocorrelation, with some additional false detections. FAST is expected to realize its full potential when applied to extremely long duration data sets over a distributed network of seismic stations. The widespread application of FAST has the potential to aid in the discovery of unexpected seismic signals, improve seismic monitoring, and promote a greater understanding of a variety of earthquake processes. PMID:26665176

  3. A REST-FRAME OPTICAL VIEW ON z {approx} 4 GALAXIES. I. COLOR AND AGE DISTRIBUTIONS FROM DEEP IRAC PHOTOMETRY OF THE IUDF10 AND GOODS SURVEYS

    SciTech Connect

    Oesch, P. A.; Illingworth, G. D.; Gonzalez, V.; Holden, B. P.; Magee, D.; Trenti, M.; Van Dokkum, P. G.

    2013-08-01

    We present a study of rest-frame UV-to-optical color distributions for z {approx} 4 galaxies based on the combination of deep HST/ACS+WFC3/IR data with Spitzer/IRAC imaging. In particular, we use new, ultra-deep data from the IRAC Ultradeep Field program (IUDF10), together with previous, public IRAC data over the GOODS fields. Our sample contains a total of {approx}2600 galaxies selected as B-dropout Lyman-break Galaxies in the HUDF and its deep parallel field HUDF09-2, as well as GOODS-North/South. This sample is used to investigate the UV continuum slopes {beta} and Balmer break colors (J{sub 125} - [4.5]) as a function of rest-frame optical luminosity (using [4.5] to avoid optical emission lines). We find that galaxies at M{sub z} < -21.5 (roughly corresponding to L{sup *}{sub z{approx}4}) are significantly redder than their lower luminosity counterparts. The UV continuum slopes and the J{sub 125} - [4.5] colors are well correlated, indicating that the dust reddening at these redshifts is better described by an SMC-like extinction curve, rather than the typically assumed Calzetti reddening. After dust correction, we find that the galaxy population shows mean stellar population ages in the range 10{sup 8.5} to 10{sup 9} yr, with a dispersion of {approx}0.5 dex, and only weak trends as a function of luminosity. Only a small fraction of galaxies shows Balmer break colors consistent with extremely young ages, younger than 100 Myr. Under the assumption of smooth star-formation histories, this fraction is 12%-19% for galaxies at M{sub z} < -19.75. Our results are consistent with a gradual build-up of stars and dust in galaxies at z > 4 with only a small fraction of stars being formed in short, intense bursts of star-formation.

  4. Age, Growth and Spatial Distribution of the Life Stages of the Shortfin Mako, Isurus oxyrinchus (Rafinesque, 1810) Caught in the Western and Central Atlantic

    PubMed Central

    Barreto, Rodrigo R.; de Farias, Wialla K. T.; Andrade, Humber; Santana, Francisco M.; Lessa, Rosangela

    2016-01-01

    The shortfin mako (Isurus oxyrinchus) is a highly migratory pelagic shark that preferentially inhabits oceanic regions in practically all oceans. The wide distribution range of this species renders it susceptible to coastal and oceanic fishing operations. The International Union for Conservation of Nature (IUCN) and the International Commission for the Conservation of Atlantic Tunas (ICCAT) consider this species to be highly vulnerable, especially due to its biological parameters, which are different from those of other sharks that occupy the same niche (e.g., Prionace glauca). Consequently, considerable declines in abundance have been detected over various parts of its range, most of which are linked to oceanic longline fishing. The species has conflicting life history parameters in studies conducted in the last 30 years, especially with regard to age and growth. The main discrepancies regard the interpretation of the periodicity of the deposition of band pairs (BPs) on vertebrae and the possibility of ontogenetic variations in growth. Shortfin mako sharks (n = 1325) were sampled by onboard observers of the Brazilian chartered pelagic longline fleet based in northeast Brazil from 2005 to 2011. Lengths were 79 to 250 and 73 to 296 cm (fork length, FL) for males and females, respectively, with a statistically significant difference in size between sexes and differences in the proportion of individuals in each size class. The onboard observers collected a subsample of vertebrae (n = 467), only 234 of which were suitable for analyses. Reliability between readings was satisfactory. However, it was not possible to validate periodicity in the formation of age bands in the sample. Thus, the von Bertalanffy growth function was used to calculate growth rates for the species through the interpretation of BPs in different scenarios: one BP per year (s1), two BPs per year (s2) and two BPs per year until five years of life (s3). Growth parameters varied for both females (Linf

  5. New Experiments and a Model-Driven Approach for Interpreting Middle Stone Age Lithic Point Function Using the Edge Damage Distribution Method.

    PubMed

    Schoville, Benjamin J; Brown, Kyle S; Harris, Jacob A; Wilkins, Jayne

    2016-01-01

    The Middle Stone Age (MSA) is associated with early evidence for symbolic material culture and complex technological innovations. However, one of the most visible aspects of MSA technologies are unretouched triangular stone points that appear in the archaeological record as early as 500,000 years ago in Africa and persist throughout the MSA. How these tools were being used and discarded across a changing Pleistocene landscape can provide insight into how MSA populations prioritized technological and foraging decisions. Creating inferential links between experimental and archaeological tool use helps to establish prehistoric tool function, but is complicated by the overlaying of post-depositional damage onto behaviorally worn tools. Taphonomic damage patterning can provide insight into site formation history, but may preclude behavioral interpretations of tool function. Here, multiple experimental processes that form edge damage on unretouched lithic points from taphonomic and behavioral processes are presented. These provide experimental distributions of wear on tool edges from known processes that are then quantitatively compared to the archaeological patterning of stone point edge damage from three MSA lithic assemblages-Kathu Pan 1, Pinnacle Point Cave 13B, and Die Kelders Cave 1. By using a model-fitting approach, the results presented here provide evidence for variable MSA behavioral strategies of stone point utilization on the landscape consistent with armature tips at KP1, and cutting tools at PP13B and DK1, as well as damage contributions from post-depositional sources across assemblages. This study provides a method with which landscape-scale questions of early modern human tool-use and site-use can be addressed.

  6. Transit time distributions and StorAge Selection functions in a sloping soil lysimeter with time-varying flow paths: Direct observation of internal and external transport variability

    NASA Astrophysics Data System (ADS)

    Kim, Minseok; Pangle, Luke A.; Cardoso, Charléne; Lora, Marco; Volkmann, Till H. M.; Wang, Yadi; Harman, Ciaran J.; Troch, Peter A.

    2016-09-01

    Transit times through hydrologic systems vary in time, but the nature of that variability is not well understood. Transit times variability was investigated in a 1 m3 sloping lysimeter, representing a simplified model of a hillslope receiving periodic rainfall events for 28 days. Tracer tests were conducted using an experimental protocol that allows time-variable transit time distributions (TTDs) to be calculated from data. Observed TTDs varied with the storage state of the system, and the history of inflows and outflows. We propose that the observed time variability of the TTDs can be decomposed into two parts: "internal" variability associated with changes in the arrangement of, and partitioning between, flow pathways; and "external" variability driven by fluctuations in the flow rate along all flow pathways. These concepts can be defined quantitatively in terms of rank StorAge Selection (rSAS) functions, which is a theory describing lumped transport dynamics. Internal variability is associated with temporal variability in the rSAS function, while external is not. The rSAS function variability was characterized by an "inverse storage effect," whereby younger water is released in greater proportion under wetter conditions than drier. We hypothesize that this effect is caused by the rapid mobilization of water in the unsaturated zone by the rising water table. Common approximations used to model transport dynamics that neglect internal variability were unable to reproduce the observed breakthrough curves accurately. This suggests that internal variability can play an important role in hydrologic transport dynamics, with implications for field data interpretation and modeling.

  7. New Experiments and a Model-Driven Approach for Interpreting Middle Stone Age Lithic Point Function Using the Edge Damage Distribution Method

    PubMed Central

    Schoville, Benjamin J.; Brown, Kyle S.; Harris, Jacob A.; Wilkins, Jayne

    2016-01-01

    The Middle Stone Age (MSA) is associated with early evidence for symbolic material culture and complex technological innovations. However, one of the most visible aspects of MSA technologies are unretouched triangular stone points that appear in the archaeological record as early as 500,000 years ago in Africa and persist throughout the MSA. How these tools were being used and discarded across a changing Pleistocene landscape can provide insight into how MSA populations prioritized technological and foraging decisions. Creating inferential links between experimental and archaeological tool use helps to establish prehistoric tool function, but is complicated by the overlaying of post-depositional damage onto behaviorally worn tools. Taphonomic damage patterning can provide insight into site formation history, but may preclude behavioral interpretations of tool function. Here, multiple experimental processes that form edge damage on unretouched lithic points from taphonomic and behavioral processes are presented. These provide experimental distributions of wear on tool edges from known processes that are then quantitatively compared to the archaeological patterning of stone point edge damage from three MSA lithic assemblages—Kathu Pan 1, Pinnacle Point Cave 13B, and Die Kelders Cave 1. By using a model-fitting approach, the results presented here provide evidence for variable MSA behavioral strategies of stone point utilization on the landscape consistent with armature tips at KP1, and cutting tools at PP13B and DK1, as well as damage contributions from post-depositional sources across assemblages. This study provides a method with which landscape-scale questions of early modern human tool-use and site-use can be addressed. PMID:27736886

  8. What Difference Reveals about Similarity

    ERIC Educational Resources Information Center

    Sagi, Eyal; Gentner, Dedre; Lovett, Andrew

    2012-01-01

    Detecting that two images are different is faster for highly dissimilar images than for highly similar images. Paradoxically, we showed that the reverse occurs when people are asked to describe "how" two images differ--that is, to state a difference between two images. Following structure-mapping theory, we propose that this…

  9. Phylogenetic metrics of community similarity.

    PubMed

    Ives, Anthony R; Helmus, Matthew R

    2010-11-01

    We derive a new metric of community similarity that takes into account the phylogenetic relatedness among species. This metric, phylogenetic community dissimilarity (PCD), can be partitioned into two components, a nonphylogenetic component that reflects shared species between communities (analogous to Sørensen' s similarity metric) and a phylogenetic component that reflects the evolutionary relationships among nonshared species. Therefore, even if a species is not shared between two communities, it will increase the similarity of the two communities if it is phylogenetically related to species in the other community. We illustrate PCD with data on fish and aquatic macrophyte communities from 59 temperate lakes. Dissimilarity between fish communities associated with environmental differences between lakes often has a phylogenetic component, whereas this is not the case for macrophyte communities. With simulations, we then compare PCD with two other metrics of phylogenetic community similarity, II(ST) and UniFrac. Of the three metrics, PCD was best at identifying environmental drivers of community dissimilarity, showing lower variability and greater statistical power. Thus, PCD is a statistically powerful metric that separates the effects of environmental drivers on compositional versus phylogenetic components of community structure.

  10. What causes similarity in catchments?

    NASA Astrophysics Data System (ADS)

    Savenije, Hubert

    2014-05-01

    One of the biggest issues in hydrology is how to handle the heterogeneity of catchment properties at different scales. But is this really such a big issue? Is this problem not merely the consequence of how we conceptualise and how we model catchments? Is there not far more similarity than we observe. Maybe we are not looking at the right things or at the right scale to see the similarity. The identity of catchments is largely determined by: the landscape, the ecosystem living on the landscape, and the geology, in that order. Soils, which are often seen as a crucial aspect of hydrological behaviour, are far less important, as will be demonstrated. The main determinants of hydrological behaviour are: the landscape composition, the rooting depth and the phenology. These determinants are a consequence of landscape and ecosystem evolution, which, in turn, are the manifestations of entropy production. There are striking similarities between catchments. The different runoff processes from hillslopes are linked and similar in different environments (McDonnell, 2013). Wetlands behave similarly all over the world. The key is to classify landscapes and to link the ecosystems living on them to climate. The ecosystem then is the main controller of hydrological behaviour. Besides phenology, the rooting depth is key in determining runoff behaviour. Both are strongly linked to climate and much less to soil properties. An example is given of how rooting depth is determined by climate, and how rooting depth can be predicted without calibration, providing a strong constraints on the prediction of rainfall partitioning and catchment runoff.

  11. Older Patients with Myeloma Derive Similar Benefit from Autologous Transplantation

    PubMed Central

    Sharma, Manish; Zhang, Mei-Jie; Zhong, Xiaobo; Abidi, Muneer H.; Akpek, Görgün; Bacher, Ulrike; Callander, Natalie S.; Dispenzieri, Angela; Freytes, César O.; Fung, Henry C.; Gale, Robert Peter; Gasparetto, Cristina; Gibson, John; Holmberg, Leona A.; Kindwall-Keller, Tamila L.; Klumpp, Thomas R.; Krishnan, Amrita Y.; Landau, Heather J.; Lazarus, Hillard M.; Lonial, Sagar; Maiolino, Angelo; Marks, David I.; Mehta, Paulette; Med, Joseph R. Mikhael; Nishihori, Taiga; Olsson, Richard; Ramanathan, Muthalagu; Roy, Vivek; Savani, Bipin N.; Schouten, Harry C.; Scott, Emma; Tay, Jason; To, Luen Bik; Vesole, David H.; Vogl, Dan T.; Hari, Parameswaran

    2014-01-01

    Autologous hematopoietic cell transplantation (AHCT) for plasma cell myeloma is performed less often in people >70 years old than in people ≤70 years old. We analyzed 11,430 AHCT recipients for plasma cell myeloma prospectively reported to the Center for International Blood and Marrow Transplant Research between 2008 and 2011, representing the majority of US AHCT activity during this period. Survival (OS) was compared in 3 cohorts: ages 18 to 59 years (n = 5818), 60 to 69 years (n = 4666), and >70 years (n = 946). Median OS was not reached for any cohort. In multivariate analysis, increasing age was associated with mortality (P = .0006). Myeloma-specific mortality was similar among cohorts at 12%, indicating an age-related effect on nonmyeloma mortality. Analyses were performed in a representative subgroup comparing relapse rate, progression-free survival (PFS), and nonrelapse mortality (NRM). One-year NRM was 0% for age >70 years and 2% for other ages (P = not significant). The three-year relapse rate was 56% in age 18 to 59 years, 61% in age 60 to 69 years, and 63% age >70 (P = not significant). Three-year PFS was similar at 42% in age 18 to 59 years, 38% in age 60 to 69 years, and 33% in age >70 years (P = not significant). Po