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Sample records for age class distribution

  1. 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.

  2. Distribution of age-classes of striped weakfish ( Cynoscion guatucupa) along an estuarine-marine gradient: Correlations with the environmental parameters

    NASA Astrophysics Data System (ADS)

    Jaureguizar, Andres J.; Ruarte, Claudio; Guerrero, Raúl A.

    2006-03-01

    The age-class distribution of the striped weakfish ( Cynoscion guatucupa) and its relationship with environmental factors were evaluated along the coast between Argentina and Uruguay, including the Río de la Plata estuary (36° S, 56° W). One hundred and seven stations were sampled between 2001 and 2003 during autumn, winter, and spring. Multivariate analyses (Cluster and MDS) were used to define sampling station groups, and a BIO-ENV procedure used to estimate the association of stations with environmental factors (depth, stratification, temperature and salinity of surface and bottom waters). The BIO-ENV procedure indicated that the salinity during autumn-winter and the temperature in spring had a significant influence on the spatial age-class pattern. The proportion of the youngest age-classes decreased from the estuarine area to the marine coastal area, except during spring where it showed the reverse pattern. The older age-classes inhabited the marine coastal area (more saline) toward the deepest zone, while the youngest individuals inhabited the outer estuarine area. Examination of the coastal circulation associated with the spatial distribution, and of the age-class frequency in the estuarine and marine coastal area, suggested that spawning took place in inshore coastal waters at very shallow depths.

  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. 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.

  5. Age-class determination of canvasbacks

    USGS Publications Warehouse

    Serie, J.R.; Trauger, D.L.; Doty, H.A.; Sharp, D.E.

    1982-01-01

    A technique was developed to distinguish yearling from adult canvasbacks (Aythya valisineria) in the field during spring on the basis of white flecking on the distal ends of selected wing feathers. Covert feathers from adults had well-defined vermiculation patterns whereas feathers from yearlings lacked such markings. These age-related characters were confirmed by paired comparisons of feathers from the same captive birds in consecutive years and by discriminant analysis of feathers using densitometric measurements from known-age wild birds. Reflective densitometric measurements of greater secondary coverts for females and males were significantly different between 1- and 2-year-old and between 2- and 3-year-old canvasbacks. Greater secondary coverts were the best feathers for recognizing age-classes of males and females. Densitometric values indicate low variability among different observers and within samples.

  6. Age distribution of anginose mononucleosis.

    PubMed Central

    Spirer, Z; Holtzman, M; Melamed, I; Shalit, I

    1987-01-01

    The age distribution of anginose infectious mononucleosis in children was analysed retrospectively for the years 1966-85. During that period the disease became significantly more common in children of a young age and less common in older children. This shift could not be attributed either to socioeconomic conditions or to the diagnostic methods used. PMID:3619480

  7. Distribution of P, K, Ca, Mg, Cd, Cu, Fe, Mn, Pb and Zn in wood and bark age classes of willows and poplars used for phytoextraction on soils contaminated by risk elements.

    PubMed

    Zárubová, Pavla; Hejcman, Michal; Vondráčková, Stanislava; Mrnka, Libor; Száková, Jiřina; Tlustoš, Pavel

    2015-12-01

    Fast-growing clones of Salix and Populus have been studied for remediation of soils contaminated by risk elements (RE) using short-rotation coppice plantations. Our aim was to assess biomass yield and distributions of elements in wood and bark of highly productive willow (S1--[Salix schwerinii × Salix viminalis] × S. viminalis, S2--Salix × smithiana clone S-218) and poplar (P1--Populus maximowiczii × Populus nigra, P2--P. nigra) clones with respect to aging. The field experiment was established in April 2008 on moderately Cd-, Pb- and Zn- contaminated soil. Shoots were harvested after four seasons (February 2012) and separated into annual classes of wood and bark. All tested clones grew on contaminated soils, with highest biomass production and lowest mortality exhibited by P1 and S2. Concentrations of elements, with exception of Ca and Pb, decreased with age and were higher in bark than in wood. The Salix clones were characterised by higher removal of Cd, Mn and Zn compared to the Populus clones. Despite generally higher RE content in young shoots, partly due to lower wood/bark ratios and higher RE concentrations in bark, the overall removal of RE was higher in older wood classes due to higher biomass yield. Thus, longer rotations seem to be more effective when phytoextraction strategy is considered. Of the four selected clones, S1 exhibited the best removal of Cd and Zn and is a good candidate for phytoextraction.

  8. The Effect of Mixed-Age Classes in Sweden

    ERIC Educational Resources Information Center

    Lindstrom, Elly-Ann; Lindahl, Erica

    2011-01-01

    Mixed-aged (MA) classes are a common phenomenon around the world. In Sweden, these types of classes increased rapidly during the 1980s and 1990s, despite the fact that existing empirical support for MA classes is weak. In this paper, the effect of attending an MA class during grades 4-6 on students' cognitive skills is estimated. Using a unique…

  9. Aging and the statistical learning of grammatical form classes.

    PubMed

    Schwab, Jessica F; Schuler, Kathryn D; Stillman, Chelsea M; Newport, Elissa L; Howard, James H; Howard, Darlene V

    2016-08-01

    Language learners must place unfamiliar words into categories, often with few explicit indicators about when and how that word can be used grammatically. Reeder, Newport, and Aslin (2013) showed that college students can learn grammatical form classes from an artificial language by relying solely on distributional information (i.e., contextual cues in the input). Here, 2 experiments revealed that healthy older adults also show such statistical learning, though they are poorer than young at distinguishing grammatical from ungrammatical strings. This finding expands knowledge of which aspects of learning vary with aging, with potential implications for second language learning in late adulthood. (PsycINFO Database Record PMID:27294711

  10. Distributed One-Class Support Vector Machine.

    PubMed

    Castillo, Enrique; Peteiro-Barral, Diego; Berdiñas, Bertha Guijarro; Fontenla-Romero, Oscar

    2015-11-01

    This paper presents a novel distributed one-class classification approach based on an extension of the ν-SVM method, thus permitting its application to Big Data data sets. In our method we will consider several one-class classifiers, each one determined using a given local data partition on a processor, and the goal is to find a global model. The cornerstone of this method is the novel mathematical formulation that makes the optimization problem separable whilst avoiding some data points considered as outliers in the final solution. This is particularly interesting and important because the decision region generated by the method will be unaffected by the position of the outliers and the form of the data will fit more precisely. Another interesting property is that, although built in parallel, the classifiers exchange data during learning in order to improve their individual specialization. Experimental results using different datasets demonstrate the good performance in accuracy of the decision regions of the proposed method in comparison with other well-known classifiers while saving training time due to its distributed nature. PMID:26173907

  11. Food item use by coyote sex and age classes

    SciTech Connect

    Cypher, B.L.; Spencer, K.A.; Scrivner, J.H.

    1995-10-01

    Food item use by coyotes was compared between sexes and among age classes at the Naval Petroleum Reserves, California. Item use did not differ significantly between males and females. Although leporid was the item most frequently used by all age classes, item use differed significantly between pups (< 1 year), yearlings (1 year), and adults (> 1 year), probably due to differential use of secondary items. Variation in item use among age classes could potentially bias results of coyote food habit studies.

  12. Some bounds in the class of L-distributions

    SciTech Connect

    Kotlyar, V.Yu.

    1995-09-01

    The L-property is the most general {open_quotes}aging{close_quotes} property of distribution functions (d.f.s.). According to this property, the Laplace-Stieltjes transform (LST) of the corresponding d.f. F satisfies the inequality F(s){le}(1+{mu}s){sup {minus}1}, where F(s) = {integral}{sub 0} e{sup {minus}su}dF(u) and {mu} is the mean. The -property has been introduced and is widely used in reliability theory. An important component of probabilistic analysis of systems is the ability to estimate the closeness of the probability of normal operation to the exponential distribution. The {open_quotes}exponential approximation{close_quotes} error has been studied in detail for particular {open_quotes}aging{close_quotes} properties. In this article, we consider this problem for L-distributions. For d.f.s with this property we also derive other bounds that are already known for narrower classes {open_quotes}aging{close_quotes} distributions.

  13. Class Stratification in Introductory Textbooks: Relational or Distributional Models?

    ERIC Educational Resources Information Center

    Lucal, Betsy

    1994-01-01

    Maintains that most students learn how sociologists study social stratification in introductory sociology courses. Presents a content analysis of 15 introductory college textbooks to determine whether they use distributional or relational approaches as the basis for their treatment of social class. Finds that depictions of class are…

  14. 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.

  15. Aging evaluation of class 1E batteries: Seismic testing

    SciTech Connect

    Edson, J.L. )

    1990-08-01

    This report presents the results of a seismic testing program on naturally aged class 1E batteries obtained from a nuclear plant. The testing program is a Phase 2 activity resulting from a Phase 1 aging evaluation of class 1E batteries in safety systems of nuclear power plants, performed previously as a part of the US Nuclear Regulatory Commission's Nuclear Plant Aging Research Program and reported in NUREG/CR-4457. The primary purpose of the program was to evaluate the seismic ruggedness of naturally aged batteries to determine if aged batteries could have adequate electrical capacity, as determined by tests recommended by IEEE Standards, and yet have inadequate seismic ruggedness to provide needed electrical power during and after a safe shutdown earthquake (SSE) event. A secondary purpose of the program was to evaluate selected advanced surveillance methods to determine if they were likely to be more sensitive to the aging degradation that reduces seismic ruggedness. The program used twelve batteries naturally aged to about 14 years of age in a nuclear facility and tested them at four different seismic levels representative of the levels of possible earthquakes specified for nuclear plants in the United States. Seismic testing of the batteries did not cause any loss of electrical capacity. 19 refs., 29 figs., 7 tabs.

  16. Locational distribution of gene functional classes in Arabidopsis thaliana

    PubMed Central

    Riley, Michael C; Clare, Amanda; King, Ross D

    2007-01-01

    Background We are interested in understanding the locational distribution of genes and their functions in genomes, as this distribution has both functional and evolutionary significance. Gene locational distribution is known to be affected by various evolutionary processes, with tandem duplication thought to be the main process producing clustering of homologous sequences. Recent research has found clustering of protein structural families in the human genome, even when genes identified as tandem duplicates have been removed from the data. However, this previous research was hindered as they were unable to analyse small sample sizes. This is a challenge for bioinformatics as more specific functional classes have fewer examples and conventional statistical analyses of these small data sets often produces unsatisfactory results. Results We have developed a novel bioinformatics method based on Monte Carlo methods and Greenwood's spacing statistic for the computational analysis of the distribution of individual functional classes of genes (from GO). We used this to make the first comprehensive statistical analysis of the relationship between gene functional class and location on a genome. Analysis of the distribution of all genes except tandem duplicates on the five chromosomes of A. thaliana reveals that the distribution on chromosomes I, II, IV and V is clustered at P = 0.001. Many functional classes are clustered, with the degree of clustering within an individual class generally consistent across all five chromosomes. A novel and surprising result was that the locational distribution of some functional classes were significantly more evenly spaced than would be expected by chance. Conclusion Analysis of the A. thaliana genome reveals evidence of unexplained order in the locational distribution of genes. The same general analysis method can be applied to any genome, and indeed any sequential data involving classes. PMID:17397552

  17. 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.

  18. The peculiar distribution of class I and class II aldolases in diatoms and in red algae.

    PubMed

    Kroth, Peter G; Schroers, Yvonne; Kilian, Oliver

    2005-12-01

    Diatom plastids probably evolved by secondary endocytobiosis from a red alga that was up by a eukaryotic host cell. Apparently, this process increased the complexity of the intracellular distribution of metabolic enzymes. We identified genes encoding fructose-bisphosphate aldolases (FBA) in two centric (Odontella sinensis, Thalassiosira pseudonana) and one pennate (Phaeodactylum tricornutum) diatoms and found that four different aldolases are present in both groups: two plastid targeted class II enzymes (FBAC1 and FBAC2), one cytosolic class II (FBA3) and one cytosolic class I (FBA4) enzyme. The pennate Phaeodactylum possesses an additional plastidic class I enzyme (FBAC5). We verified the classification of the different aldolases in the diatoms by enzymatic characterization of isolated plastids and whole cell extracts. Interestingly, our results imply that in plastids of centric and pennate diatoms mainly either class I or class II aldolases are active. We also identified genes for both class I and class II aldolases in red algal EST databases, thus presenting a fascinating example of the reutilization and recompartmentalization of different aldolase isoenzymes during secondary endocytobiosis but as well demonstrating the limited use of metabolic enzymes as markers for the interpretation of phylogenetic histories in algae.

  19. A Study of Chinese Undergraduates' MI Distribution in EFL Class

    ERIC Educational Resources Information Center

    Liu, Ning

    2008-01-01

    This paper initiates an investigation of the college students' MI (multiple intelligences) distribution in English class. The participants are a group of Chinese sophomores from different majors: city planning, tourism, software engineering, financial administration and arts of English. With a view to make the investigation more specified in…

  20. Age structure and income distribution policy.

    PubMed

    Von Weizsacker, R K

    1988-01-01

    The dependence of earnings on age is a firmly established empirical fact. A simple microeconomic model of educational choice, being consistent with this observation, is designed. The model lends itself readily to aggregation over individuals and age groups. Thus, relations can be set up between economic variables influencing the aggregate distribution of labor incomes and demographic variables determining the age structure of the population. The main results of the present study are: 1) overall earnings inequality is shown to be an increasing function of life expectancy and a decreasing function of fertility. 2) The effectiveness of redistributive policies is sensitive to the age composition. In particular, the inequality-reducing effect of a 1% income tax rise is shown to be smaller the older the population.

  1. Spectral Energy Distribution Analysis of Class I and Class II FU Orionis Stars

    NASA Astrophysics Data System (ADS)

    Gramajo, Luciana V.; Rodón, Javier A.; Gómez, Mercedes

    2014-06-01

    FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ~80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ~10-7 M ⊙ yr-1 versus ~10-5 M ⊙ yr-1 for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (~70%) have envelope mass accretion rates above 10-7 M ⊙ yr-1. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.

  2. Spectral energy distribution analysis of class I and class II FU Orionis stars

    SciTech Connect

    Gramajo, Luciana V.; Gómez, Mercedes; Rodón, Javier A. E-mail: mercedes@oac.uncor.edu

    2014-06-01

    FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ∼80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ∼10{sup –7} M {sub ☉} yr{sup –1} versus ∼10{sup –5} M {sub ☉} yr{sup –1} for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (∼70%) have envelope mass accretion rates above 10{sup –7} M {sub ☉} yr{sup –1}. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.

  3. "Distribution and functional identification of complex class 1 integrons".

    PubMed

    Quiroga, María Paula; Arduino, Sonia Marina; Merkier, Andrea Karina; Quiroga, Cecilia; Petroni, Alejandro; Roy, Paul H; Centrón, Daniela

    2013-10-01

    The emergence of extended-spectrum β-lactamases and plasmid-mediated resistance to quinolones has been previously found to be associated with the dissemination of complex class 1 integrons in Argentina. In this study, we analyzed their distribution through time and evaluated the functionality of the Orf513 protein, which is the putative recombinase of the ISCR1 mobile element. We investigated the presence of the orf513, blaCTX-M-2, dfrA3b, qnrB10 and blaDHA-1 genes by PCR and DNA sequencing as well as their linkage to class 1 integrons in 451 non-epidemiologically related nosocomial strains resistant to at least one expanded-spectrum cephalosporin and to one aminoglycoside, isolated between 1989 and 2010 from 7 hospitals from Buenos Aires City. The epidemiology of complex class 1 integrons was found to be notably different among fermenting (94/171) and non-fermenting clinical bacilli isolates (1/280). The ISCR1::qnrB10 positive isolates were found since 1993, confirming its presence in clinical isolates more than a decade before its first description. As expected, In35::ISCR1::blaCTX-M-2 was the most common complex class 1 integron among Enterobacteriaceae isolates, particularly in Proteus mirabilis. Experimental analysis corroborated the activity of the Orf513 protein, which was found to bind specific DNA sequences containing the previously suggested oriIS region. These findings showed the high dispersion and maintenance of complex class 1 integrons across time in our nosocomial isolates. The contribution of the ISCR1 mobile element to multidrug resistant phenotypes is significant due to its sustained association to class 1 integrons. PMID:23838285

  4. Age-class structure and variability of two populations of the bluemask darter etheostoma (Doration) sp.

    USGS Publications Warehouse

    Simmons, J.W.; Layzer, J.B.; Smith, D.D.

    2008-01-01

    The bluemask darter Etheostoma (Doration) sp. is an endangered fish endemic to the upper Caney Fork system in the Cumberland River drainage in central Tennessee. Darters (Etheostoma spp.) are typically short-lived and exhibit rapid growth that quickly decreases with age. Consequently, estimating age of darters from length-frequency distributions can be difficult and subjective. We used a nonparametric kernel density estimator to reduce subjectivity in estimating ages of bluemask darters. Data were collected from a total of 2926 bluemask darters from the Collins River throughout three growing seasons. Additionally, data were collected from 842 bluemask darters from the Rocky River during one growing season. Analysis of length-frequencies indicated the presence of four age classes in both rivers. In each river, the majority of the population was comprised of fish 0.05). In both rivers, females were more abundant than males.

  5. Distribution of class 1 integrons among enteropathogenic Escherichia coli.

    PubMed

    Najibi, S; Bakhshi, B; Fallahzad, S; Pourshafie, M R; Katouli, M; Sattari, M; Alebouyeh, M; Tajbakhsh, M

    2012-05-01

    The aim of this study was to investigate the incidence of and resistance gene content of class 1 integrons among enteropathogenic Escherichia coli (EPEC) and non-EPEC and to investigate intraspecies genetic diversity of EPEC strains isolated from children with diarrhea in Iran. Twenty-eight EPEC and 16 non-EPEC strains isolated from children with diarrhea were tested for the presence of a class 1 integron associated integrase gene (int1). Sequence analysis was performed to identify the resistance gene content of integrons. Genetic diversity and cluster analysis of EPEC isolates were also investigated using enterobacterial repetitive intergenic concensus-polymerase chain reaction (ERIC-PCR) fingerprinting. Twenty-three (82%) EPEC isolates and 11 (68.7%) non-EPEC isolates harbored the int1 gene specific to the conserved integrase region of class 1 integrons. Sequence analysis revealed the dominance of dfrA and aadA gene cassettes among the isolates of both groups. ERIC-PCR fingerprinting of EPEC isolates revealed a high diversity among these isolates. The widespread distribution of 2 resistance gene families (dfrA and aadA) among both groups of EPEC and non-EPEC isolates indicates the significance of integrons in antibiotic resistance transfer among these bacteria. Furthermore, clonal diversity of EPEC isolates harbouring a class 1 integron also suggests the circulation of these mobile elements among a diverse population of EPEC in this country. PMID:22540184

  6. Design of Object-Oriented Distributed Simulation Classes

    NASA Technical Reports Server (NTRS)

    Schoeffler, James D.

    1995-01-01

    Distributed simulation of aircraft engines as part of a computer aided design package being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for "Numerical Propulsion Simulation System". NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT "Actor" model of a concurrent object and uses "connectors" to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has not

  7. Design of object-oriented distributed simulation classes

    NASA Technical Reports Server (NTRS)

    Schoeffler, James D. (Principal Investigator)

    1995-01-01

    Distributed simulation of aircraft engines as part of a computer aided design package is being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for 'Numerical Propulsion Simulation System'. NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT 'Actor' model of a concurrent object and uses 'connectors' to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has

  8. Inverted rank distributions: Macroscopic statistics, universality classes, and critical exponents

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo; Cohen, Morrel H.

    2014-01-01

    An inverted rank distribution is an infinite sequence of positive sizes ordered in a monotone increasing fashion. Interlacing together Lorenzian and oligarchic asymptotic analyses, we establish a macroscopic classification of inverted rank distributions into five “socioeconomic” universality classes: communism, socialism, criticality, feudalism, and absolute monarchy. We further establish that: (i) communism and socialism are analogous to a “disordered phase”, feudalism and absolute monarchy are analogous to an “ordered phase”, and criticality is the “phase transition” between order and disorder; (ii) the universality classes are characterized by two critical exponents, one governing the ordered phase, and the other governing the disordered phase; (iii) communism, criticality, and absolute monarchy are characterized by sharp exponent values, and are inherently deterministic; (iv) socialism is characterized by a continuous exponent range, is inherently stochastic, and is universally governed by continuous power-law statistics; (v) feudalism is characterized by a continuous exponent range, is inherently stochastic, and is universally governed by discrete exponential statistics. The results presented in this paper yield a universal macroscopic socioeconophysical perspective of inverted rank distributions.

  9. Distribution and Features of the Six Classes of Peroxiredoxins

    PubMed Central

    Poole, Leslie B.; Nelson, Kimberly J.

    2016-01-01

    Peroxiredoxins are cysteine-dependent peroxide reductases that group into 6 different, structurally discernable classes. In 2011, our research team reported the application of a bioinformatic approach called active site profiling to extract active site-proximal sequence segments from the 29 distinct, structurally-characterized peroxiredoxins available at the time. These extracted sequences were then used to create unique profiles for the six groups which were subsequently used to search GenBank(nr), allowing identification of ∼3500 peroxiredoxin sequences and their respective subgroups. Summarized in this minireview are the features and phylogenetic distributions of each of these peroxiredoxin subgroups; an example is also provided illustrating the use of the web accessible, searchable database known as PREX to identify subfamily-specific peroxiredoxin sequences for the organism Vitis vinifera (grape). PMID:26810075

  10. First in the Class? Age and the Education Production Function

    ERIC Educational Resources Information Center

    Cascio, Elizabeth U.; Schanzenbach, Diane Whitmore

    2016-01-01

    We estimate the effects of relative age in kindergarten using data from an experiment where children of the same age were randomly assigned to different kindergarten classmates. We exploit the resulting experimental variation in relative age in conjunction with variation in expected kindergarten entry age based on birth date to account for…

  11. Geophagy in chacma baboons: patterns of soil consumption by age class, sex, and reproductive state.

    PubMed

    Pebsworth, Paula A; Bardi, Massimo; Huffman, Michael A

    2012-01-01

    Despite baboons' widespread distribution across Africa, geophagy among all subspecies has been poorly documented. We used video camera traps and soil analyses to investigate geophagy in chacma baboons (Papio cynocephalus ursinus) inhabiting the Western Cape of South Africa. During an 18-month study, from August 2009 to January 2011, we continually monitored the largest and most frequently visited geophagy sites with camera traps for 545 days and captured soil consumption at one or more sites on 266 of those days (49%). In 3,500 baboon visits to geophagy sites, video camera traps captured 58.6 hr of geophagy. From these data, we evaluated site preference based on time spent consuming soil among these four geophagy sites. One hundred and seventy days of soil consumption data from the most frequently visited geophagy site allowed us to look for demographic trends in geophagy. Selected consumed soils from geophagy sites were analyzed for mineral, physical, and chemical properties. The baboons spent more time consuming white alkaline soils with high percentages of clay and fine silt, which contained higher concentrations of sodium than non-white acidic soils that contained higher concentrations of iron. Our data indicate that pregnant chacma baboons spent more time consuming soil at monitored geophagy sites than baboons of any other age class, sex, or reproductive state. Based on analytical results, the soils consumed would be effective at alleviating gastrointestinal distress and possibly supplementing minerals for all age/sex classes, but potentially for different age/sex requirements. PMID:21969111

  12. Distributional Phonetic Learning at 10 Months of Age

    ERIC Educational Resources Information Center

    Yoshida, Katherine A.; Pons, Ferran; Maye, Jessica; Werker, Janet F.

    2010-01-01

    Infant phonetic perception reorganizes in accordance with the native language by 10 months of age. One mechanism that may underlie this perceptual change is distributional learning, a statistical analysis of the distributional frequency of speech sounds. Previous distributional learning studies have tested infants of 6-8 months, an age at which…

  13. Latent Trajectory Classes for Alcohol-Related Blackouts from Age 15 to 19 in ALSPAC

    PubMed Central

    Schuckit, Marc A.; Smith, Tom L.; Heron, Jon; Hickman, Matthew; Macleod, John; Munafo, Marcus R.; Kendler, Kenneth S.; Dick, Danielle M.; Davey-Smith, George

    2014-01-01

    Background Alcohol-related blackouts (ARBs) are reported by ~50% of drinkers. While much is known about the prevalence of ARBs in young adults and their cross-sectional correlates, there are few prospective studies regarding their trajectories over time during mid-adolescence. This paper reports latent trajectory classes of alcohol-related blackouts between ages 15 and 19, along with predictors of those patterns. Methods Latent Class Growth Analysis (LCGA) was used to evaluate the pattern of occurrence of ARBs across four time points for 1402 drinking adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC). Multinomial regression analyses evaluated age 15 demography, substance-related items, externalizing characteristics, and estimated peer substance use as predictors of latent class membership. Results ARBs were reported at age 15 in 30% and at age 19 in 74% of these subjects. Four latent trajectory classes were identified: Class 1 (5.1%) reported no blackouts; for Class 2 (29.5%) ARBs rapidly increased with age; for Class 3 (44.9%) blackouts slowly increased; and for Class 4 (20.5%) ARBs were consistently reported. Using Class 2 (rapid increasers) as the reference, predictors of class membership included female sex, higher drinking quantities, smoking, externalizing characteristics, and estimated peer substance involvement (pseudo R2 =.22). Conclusions ARBs were common and repetitive in these young subjects, and predictors of their trajectories over time involved multiple domains representing diverse characteristics. PMID:25516068

  14. Age-class separation of blue-winged ducks

    USGS Publications Warehouse

    Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.

    1995-01-01

    Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual

  15. Short-term memory development: differences in serial position curves between age groups and latent classes.

    PubMed

    Koppenol-Gonzalez, Gabriela V; Bouwmeester, Samantha; Vermunt, Jeroen K

    2014-10-01

    In studies on the development of cognitive processes, children are often grouped based on their ages before analyzing the data. After the analysis, the differences between age groups are interpreted as developmental differences. We argue that this approach is problematic because the variance in cognitive performance within an age group is considered to be measurement error. However, if a part of this variance is systematic, it can provide very useful information about the cognitive processes used by some children of a certain age but not others. In the current study, we presented 210 children aged 5 to 12 years with serial order short-term memory tasks. First we analyze our data according to the approach using age groups, and then we apply latent class analysis to form latent classes of children based on their performance instead of their ages. We display the results of the age groups and the latent classes in terms of serial position curves, and we discuss the differences in results. Our findings show that there are considerable differences in performance between the age groups and the latent classes. We interpret our findings as indicating that the latent class analysis yielded a much more meaningful way of grouping children in terms of cognitive processes than the a priori grouping of children based on their ages.

  16. 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.

  17. Does 3rd Age + 3rd World = 3rd Class?

    ERIC Educational Resources Information Center

    Tout, Ken

    1992-01-01

    Demographic changes, migration, and industrialization are having drastic effects on older adults in developing nations. Local programs such as Pro Vida in Colombia, supported by Help Age International, rely on the support of volunteers to improve the quality of life for elderly people. (SK)

  18. A Distribution-class Locational Marginal Price (DLMP) Index for Enhanced Distribution Systems

    NASA Astrophysics Data System (ADS)

    Akinbode, Oluwaseyi Wemimo

    The smart grid initiative is the impetus behind changes that are expected to culminate into an enhanced distribution system with the communication and control infrastructure to support advanced distribution system applications and resources such as distributed generation, energy storage systems, and price responsive loads. This research proposes a distribution-class analog of the transmission LMP (DLMP) as an enabler of the advanced applications of the enhanced distribution system. The DLMP is envisioned as a control signal that can incentivize distribution system resources to behave optimally in a manner that benefits economic efficiency and system reliability and that can optimally couple the transmission and the distribution systems. The DLMP is calculated from a two-stage optimization problem; a transmission system OPF and a distribution system OPF. An iterative framework that ensures accurate representation of the distribution system's price sensitive resources for the transmission system problem and vice versa is developed and its convergence problem is discussed. As part of the DLMP calculation framework, a DCOPF formulation that endogenously captures the effect of real power losses is discussed. The formulation uses piecewise linear functions to approximate losses. This thesis explores, with theoretical proofs, the breakdown of the loss approximation technique when non-positive DLMPs/LMPs occur and discusses a mixed integer linear programming formulation that corrects the breakdown. The DLMP is numerically illustrated in traditional and enhanced distribution systems and its superiority to contemporary pricing mechanisms is demonstrated using price responsive loads. Results show that the impact of the inaccuracy of contemporary pricing schemes becomes significant as flexible resources increase. At high elasticity, aggregate load consumption deviated from the optimal consumption by up to about 45 percent when using a flat or time-of-use rate. Individual load

  19. A Way Forward: Nurturing the Imagination at the Intersection of Race, Class, Gender, and Age

    ERIC Educational Resources Information Center

    Lockhart-Gilroy, Annie A.

    2016-01-01

    Those who are oppressed often find themselves internalizing voices that limit their ability. This article focuses on a population that falls on the non-hegemonic side of the intersection of race, class, gender, and age: Black girls from poor and working-class backgrounds. From my work with youth, I have noticed that internalizing these limiting…

  20. Age class differences in the feeding behavior of captive Japanese macaques (Macaca fuscataia) in the forested and nonvegetated enclosure groups.

    PubMed

    Jaman, M Firoj; Huffman, Michael A

    2011-01-01

    Age class differences in feeding behavior of primates are affected by many factors, including feeding competition, foraging skills, habitat type, food abundance and distribution, body mass, and food types. Two captive groups of Japanese macaques (Macaca fuscata), one housed in a forested enclosure and the other in a nonvegetated enclosure, were studied to examine the effect of environmental enrichment on age class differences in feeding behavior. Although there was no significant age class difference in time spent feeding on provisioned foods in either enclosure, the feeding rate (intake of unit food/minute) of adults consuming provisioned monkey chow was significantly higher than that of immatures in both enclosures, and was faster for both age groups in the nonvegetated than in the forested enclosure. Overall, feeding time was greatly extended for individuals of both age classes in the forested enclosure compared with their counterparts in the nonvegetated enclosure. Immatures in the forested enclosure utilized a significantly greater number of plant species and food items, exploiting many food items available among the terminal branches, and spent significantly more time feeding than adults. Perhaps constrained by larger body size, adults fed more often on the ground or middle height of the trees, likely reducing competition over plant food resources between adults and immatures. The natural vegetation played an important role in extending feeding time and segregating substrate use during feeding by adults and immatures. This study revealed the benefits concerning environmental enrichment of a naturally forested enclosure, which provides captive primates the opportunity to exhibit age class and species-typical feeding behaviors of importance for their dietary maintenance and general health.

  1. Comparison of Statistical Population Reconstruction Using Full and Pooled Adult Age-Class Data

    PubMed Central

    Skalski, John R.; Millspaugh, Joshua J.; Clawson, Michael V.

    2012-01-01

    Background Age-at-harvest data are among the most commonly collected, yet neglected, demographic data gathered by wildlife agencies. Statistical population construction techniques can use this information to estimate the abundance of wild populations over wide geographic areas and concurrently estimate recruitment, harvest, and natural survival rates. Although current reconstruction techniques use full age-class data (0.5, 1.5, 2.5, 3.5, … years), it is not always possible to determine an animal's age due to inaccuracy of the methods, expense, and logistics of sample collection. The ability to inventory wild populations would be greatly expanded if pooled adult age-class data (e.g., 0.5, 1.5, 2.5+ years) could be successfully used in statistical population reconstruction. Methodology/Principal Findings We investigated the performance of statistical population reconstruction models developed to analyze full age-class and pooled adult age-class data. We performed Monte Carlo simulations using a stochastic version of a Leslie matrix model, which generated data over a wide range of abundance levels, harvest rates, and natural survival probabilities, representing medium-to-big game species. Results of full age-class and pooled adult age-class population reconstructions were compared for accuracy and precision. No discernible difference in accuracy was detected, but precision was slightly reduced when using the pooled adult age-class reconstruction. On average, the coefficient of variation increased by 0.059 when the adult age-class data were pooled prior to analyses. The analyses and maximum likelihood model for pooled adult age-class reconstruction are illustrated for a black-tailed deer (Odocoileus hemionus) population in Washington State. Conclusions/Significance Inventorying wild populations is one of the greatest challenges of wildlife agencies. These new statistical population reconstruction models should expand the demographic capabilities of wildlife agencies

  2. Who tweets? Deriving the demographic characteristics of age, occupation and social class from twitter user meta-data.

    PubMed

    Sloan, Luke; Morgan, Jeffrey; Burnap, Pete; Williams, Matthew

    2015-01-01

    This paper specifies, designs and critically evaluates two tools for the automated identification of demographic data (age, occupation and social class) from the profile descriptions of Twitter users in the United Kingdom (UK). Meta-data data routinely collected through the Collaborative Social Media Observatory (COSMOS: http://www.cosmosproject.net/) relating to UK Twitter users is matched with the occupational lookup tables between job and social class provided by the Office for National Statistics (ONS) using SOC2010. Using expert human validation, the validity and reliability of the automated matching process is critically assessed and a prospective class distribution of UK Twitter users is offered with 2011 Census baseline comparisons. The pattern matching rules for identifying age are explained and enacted following a discussion on how to minimise false positives. The age distribution of Twitter users, as identified using the tool, is presented alongside the age distribution of the UK population from the 2011 Census. The automated occupation detection tool reliably identifies certain occupational groups, such as professionals, for which job titles cannot be confused with hobbies or are used in common parlance within alternative contexts. An alternative explanation on the prevalence of hobbies is that the creative sector is overrepresented on Twitter compared to 2011 Census data. The age detection tool illustrates the youthfulness of Twitter users compared to the general UK population as of the 2011 Census according to proportions, but projections demonstrate that there is still potentially a large number of older platform users. It is possible to detect "signatures" of both occupation and age from Twitter meta-data with varying degrees of accuracy (particularly dependent on occupational groups) but further confirmatory work is needed.

  3. Who Tweets? Deriving the Demographic Characteristics of Age, Occupation and Social Class from Twitter User Meta-Data

    PubMed Central

    Sloan, Luke; Morgan, Jeffrey; Burnap, Pete; Williams, Matthew

    2015-01-01

    This paper specifies, designs and critically evaluates two tools for the automated identification of demographic data (age, occupation and social class) from the profile descriptions of Twitter users in the United Kingdom (UK). Meta-data data routinely collected through the Collaborative Social Media Observatory (COSMOS: http://www.cosmosproject.net/) relating to UK Twitter users is matched with the occupational lookup tables between job and social class provided by the Office for National Statistics (ONS) using SOC2010. Using expert human validation, the validity and reliability of the automated matching process is critically assessed and a prospective class distribution of UK Twitter users is offered with 2011 Census baseline comparisons. The pattern matching rules for identifying age are explained and enacted following a discussion on how to minimise false positives. The age distribution of Twitter users, as identified using the tool, is presented alongside the age distribution of the UK population from the 2011 Census. The automated occupation detection tool reliably identifies certain occupational groups, such as professionals, for which job titles cannot be confused with hobbies or are used in common parlance within alternative contexts. An alternative explanation on the prevalence of hobbies is that the creative sector is overrepresented on Twitter compared to 2011 Census data. The age detection tool illustrates the youthfulness of Twitter users compared to the general UK population as of the 2011 Census according to proportions, but projections demonstrate that there is still potentially a large number of older platform users. It is possible to detect “signatures” of both occupation and age from Twitter meta-data with varying degrees of accuracy (particularly dependent on occupational groups) but further confirmatory work is needed. PMID:25729900

  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. Discriminating between Survivors and Nonsurvivors among Working Class Aged Living in the Community.

    ERIC Educational Resources Information Center

    Harel, Zev

    1979-01-01

    The predictive significance of select variables on survival was ascertained among community-living aged of working class background. Sex and performance of daily routines were found to be better initial discriminators, while age and a perceptual style variable termed field dependence/independence were found to have better long-range predictive…

  6. 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

  7. 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.

  8. 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

  9. 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. PMID:25946335

  10. Epidemiology of Neisseria meningitidis infections: case distribution by age and relevance of carriage.

    PubMed

    Gabutti, G; Stefanati, A; Kuhdari, P

    2015-01-01

    Notwithstanding different meningococcal serogroups have changed their distribution and their impact in different age classes over time, N. meningitidis' invasive diseases are a major public health issue worldwide, due to the related complications and severe sequelae. Nowadays, the highest rates of invasive disease are registered in children younger than 1 year of age, with a second lesser peak in adolescents and young adults (15-25 years of age). On the contrary, the prevalence of carriage is low in newborns and in school-age children, and increases during adolescence and young-adult age; then it decreases again in older age. N. meningitidis' infection prevalence has greatly decreased in Europe and North America thanks to the use of conjugate vaccines (MenC and MenACWY) as well as the incidence of invasive disease due to serogroup A in sub-saharian Africa after the introduction of MenAfriVac conjugate vaccine. The great success of conjugate vaccines is related not only to the direct protection from disease but also to the impact on carriage; this latter allows an indirect protection of unimmunized subjects. For these reasons, the implementation of immunization with the new generation vaccines in the age classes most impacted by disease and carriage (first year of life, adolescence and young adulthood) could permit to achieve an extraordinary decrease of the incidence of meningococcal disease. PMID:26788731

  11. Social Skills Expression of Senior High School Age Students in Physical Education Classes

    ERIC Educational Resources Information Center

    Akelaitis, Arturas V.

    2015-01-01

    The main purpose of the present study is to reveal the peculiarities of social skills expression of senior high school age students in physical education classes. The independent random sample consisted of 244 (15-16 years old) students and 258 (17-18 years old) students, of which there were 224 boys and 278 girls. L. Bulotaite and V. Gudžinskiene…

  12. Effects of Age, Gender, School Class on Cardiopulmonary Resuscitation Skills of Nigerian Secondary School Students

    ERIC Educational Resources Information Center

    Onyeaso, Adedamola Olutoyin; Onyeaso, Chukwudi Ochi

    2016-01-01

    Background: The need for training of schoolchildren on cardiopulmonary resuscitation (CPR) as potential bystander CPR providers is growing globally but Nigeria is still behind and lacks basic necessary data. Purpose: The purpose of this study was to investigate the effects of age, gender and school class on CPR skills of Nigerian secondary school…

  13. Polymorphic mountain whitefish (Prosopium williamsoni) in a coastal riverscape: size class assemblages, distribution, and habitat associations

    USGS Publications Warehouse

    Starr, James C.; Torgersen, Christian

    2015-01-01

    We compared the assemblage structure, spatial distributions, and habitat associations of mountain whitefish (Prosopium williamsoni) morphotypes and size classes. We hypothesised that morphotypes would have different spatial distributions and would be associated with different habitat features based on feeding behaviour and diet. Spatially continuous sampling was conducted over a broad extent (29 km) in the Calawah River, WA (USA). Whitefish were enumerated via snorkelling in three size classes: small (10–29 cm), medium (30–49 cm), and large (≥50 cm). We identified morphotypes based on head and snout morphology: a pinocchio form that had an elongated snout and a normal form with a blunted snout. Large size classes of both morphotypes were distributed downstream of small and medium size classes, and normal whitefish were distributed downstream of pinocchio whitefish. Ordination of whitefish assemblages with nonmetric multidimensional scaling revealed that normal whitefish size classes were associated with higher gradient and depth, whereas pinocchio whitefish size classes were positively associated with pool area, distance upstream, and depth. Reach-scale generalised additive models indicated that normal whitefish relative density was associated with larger substrate size in downstream reaches (R2 = 0.64), and pinocchio whitefish were associated with greater stream depth in the reaches farther upstream (R2 = 0.87). These results suggest broad-scale spatial segregation (1–10 km), particularly between larger and more phenotypically extreme individuals. These results provide the first perspective on spatial distributions and habitat relationships of polymorphic mountain whitefish.

  14. Estimating the Age Distribution of Oceanic Dissolved Organic Carbon

    NASA Astrophysics Data System (ADS)

    Follett, C. L.; Forney, D. C.; Repeta, D.; Rothman, D.

    2010-12-01

    Dissolved organic carbon (DOC) is a large, ubiquitous component of open ocean water at all depths and impacts atmospheric carbon dioxide levels at both short and long timescales. It is currently believed that oceanic DOC contains a multi-thousand-year-old refractory deep-water component which is mixed with a young labile component in surface waters. Unfortunately, the only evidence for this comes from a few isolated depth profiles of both DOC concentration and bulk radiocarbon. Although the profile data is consistent with a two-component mixing model, directly separating the two components has proven to be a challenge. We explore the validity of the two component mixing model by directly estimating the age distribution of oceanic DOC. The two-component model suggests that the age distribution is composed of two distinct peaks. In order to obtain an estimate of the age distribution we first record changes in both concentration and percent radiocarbon as a sample is oxidized under ultra-violet radiation [1]. We formulate a mathematical model relating the age distribution to these changes, assuming that they result from components of different radiocarbon age and UV-reactivity. This allows us to numerically invert the data and estimate the age distribution. We apply our procedure to DOC samples collected from three distinct depths (50, 500, and 2000 meters) in the north-central Pacific Ocean. [1] S.R. Beaupre, E.R.M. Druffel, and S. Griffin. A low-blank photochemical extraction system for concentration and isotopic analyses of marine dissolved organic carbon. Limnol. Oceanogr. Methods, 5:174-184, 2007.

  15. Effects of intraborehole flow on groundwater age distribution

    USGS Publications Warehouse

    Zinn, B.A.; Konikow, L.F.

    2007-01-01

    Environmental tracers are used to estimate groundwater ages and travel times, but the strongly heterogeneous nature of many subsurface environments can cause mixing between waters of highly disparate ages, adding additional complexity to the age-estimation process. Mixing may be exacerbated by the presence of wells because long open intervals or long screens with openings at multiple depths can transport water and solutes rapidly over a large vertical distance. The effect of intraborehole flow on groundwater age was examined numerically using direct age transport simulation coupled with the Multi-Node Well Package of MODFLOW. Ages in a homogeneous, anisotropic aquifer reached a predevelopment steady state possessing strong depth dependence. A nonpumping multi-node well was then introduced in one of three locations within the system. In all three cases, vertical transport along the well resulted in substantial changes in age distributions within the system. After a pumping well was added near the nonpumping multi-node well, ages were further perturbed by a flow reversal in the nonpumping multi-node well. Results indicated that intraborehole flow can substantially alter groundwater ages, but the effects are highly dependent on local or regional flow conditions and may change with time. ?? Springer-Verlag 2007.

  16. Dynamic analysis of a hepatitis B model with three-age-classes

    NASA Astrophysics Data System (ADS)

    Zhang, Suxia; Zhou, Yicang

    2014-07-01

    Based on the fact that the likelihood of becoming chronically infected is dependent on age at primary infection Kane (1995) [2], Edmunds et al. (1993) [3], Medley et al. (2001) [4], and Ganem and Prince (2004) [6], we formulate a hepatitis B transmission model with three age classes. The reproduction number, R0 is defined and the dynamical behavior of the model is analyzed. It is proved that the disease-free equilibrium is globally stable if R0<1, and there exists at least one endemic equilibrium and that the disease is uniformly persistent if R0>1. The unique endemic equilibrium and its global stability is obtained in a special case. Simulations are also conducted to compare the dynamical behavior of the model with and without age classes.

  17. Relative Age Effects in Mathematics and Reading: Investigating the Generalizability across Students, Time and Classes

    PubMed Central

    Thoren, Katharina; Heinig, Elisa; Brunner, Martin

    2016-01-01

    A child's age in comparison to the age of her or his classmates (relative age) has been found to be an influential factor on academic achievement, particularly but not exclusively at the beginning of formal schooling. However, few studies have focused on the generalizability of relative age effects. To close this gap, the present study analyzes the generalizability across students with and without immigrant backgrounds, across three student cohorts that entered school under a changing law of school enrollment, and across classes. To this end, we capitalized on representative large-scale data sets from three student cohorts attending public schools in Berlin, the capital of Germany. We analyzed the data using a multilevel framework. Our results for the overall student sample indicate relative age effects for reading and mathematics in favor of the relatively older students in Grade 2 that become somewhat smaller in size in Grade 3. By Grade 8, relative age effects had vanished in reading and had even reversed in favor of the relatively young in mathematics. Furthermore, relative age effects were not found to be systematically different among students with and without immigrant backgrounds, student cohorts, or across classes. Taken together, these results empirically underscore the broad generalizability of the findings as found for the overall student population and replicate the pattern of findings on relative effects as identified by the majority of previous studies. PMID:27242593

  18. Relative Age Effects in Mathematics and Reading: Investigating the Generalizability across Students, Time and Classes.

    PubMed

    Thoren, Katharina; Heinig, Elisa; Brunner, Martin

    2016-01-01

    A child's age in comparison to the age of her or his classmates (relative age) has been found to be an influential factor on academic achievement, particularly but not exclusively at the beginning of formal schooling. However, few studies have focused on the generalizability of relative age effects. To close this gap, the present study analyzes the generalizability across students with and without immigrant backgrounds, across three student cohorts that entered school under a changing law of school enrollment, and across classes. To this end, we capitalized on representative large-scale data sets from three student cohorts attending public schools in Berlin, the capital of Germany. We analyzed the data using a multilevel framework. Our results for the overall student sample indicate relative age effects for reading and mathematics in favor of the relatively older students in Grade 2 that become somewhat smaller in size in Grade 3. By Grade 8, relative age effects had vanished in reading and had even reversed in favor of the relatively young in mathematics. Furthermore, relative age effects were not found to be systematically different among students with and without immigrant backgrounds, student cohorts, or across classes. Taken together, these results empirically underscore the broad generalizability of the findings as found for the overall student population and replicate the pattern of findings on relative effects as identified by the majority of previous studies.

  19. Relative Age Effects in Mathematics and Reading: Investigating the Generalizability across Students, Time and Classes.

    PubMed

    Thoren, Katharina; Heinig, Elisa; Brunner, Martin

    2016-01-01

    A child's age in comparison to the age of her or his classmates (relative age) has been found to be an influential factor on academic achievement, particularly but not exclusively at the beginning of formal schooling. However, few studies have focused on the generalizability of relative age effects. To close this gap, the present study analyzes the generalizability across students with and without immigrant backgrounds, across three student cohorts that entered school under a changing law of school enrollment, and across classes. To this end, we capitalized on representative large-scale data sets from three student cohorts attending public schools in Berlin, the capital of Germany. We analyzed the data using a multilevel framework. Our results for the overall student sample indicate relative age effects for reading and mathematics in favor of the relatively older students in Grade 2 that become somewhat smaller in size in Grade 3. By Grade 8, relative age effects had vanished in reading and had even reversed in favor of the relatively young in mathematics. Furthermore, relative age effects were not found to be systematically different among students with and without immigrant backgrounds, student cohorts, or across classes. Taken together, these results empirically underscore the broad generalizability of the findings as found for the overall student population and replicate the pattern of findings on relative effects as identified by the majority of previous studies. PMID:27242593

  20. Pension benefits among the aged: conflicting measures, unequal distributions.

    PubMed

    Woods, J R

    1996-01-01

    Estimates of total benefits paid by employer sponsored pension plans seem to vary widely between different data sources and measures. Such discrepancies have been used to support differing conclusions about the effectiveness of the pension system. This article examines several measures of aggregate pension benefits in 1990, a year particularly rich in available data. Exploratory analysis suggests that the greatest source of discrepancy lies in differing treatments of lump-sum distributions, although the study also identifies several other types of payments that are variously, and erroneously, counted as pension income. Age of recipients is an important factor in analyzing different measures of aggregate pension benefits; discrepancies are much smaller among the aged than in the population as a whole. The analysis also provides new evidence about the unequal distribution of pension benefits among the aged, confirming from two data sources that benefits are heavily concentrated among higher income groups.

  1. The relation between overweight and subjective health according to age, social class, slimming behavior and smoking habits in Dutch adults.

    PubMed Central

    Seidell, J C; Bakx, K C; Deurenberg, P; Burema, J; Hautvast, J G; Huygen, F J

    1986-01-01

    Subjective health status was assessed in relation to overweight by administering a list of 51 health complaints to adult men and women who were either chronically overweight as defined by Body Mass Index (BMI) or not overweight, in a continuous morbidity registration in four general practices during the period 1967-83. Responses were received from 455 men (182 overweight) and 790 women (386 overweight), ages 26-66 years. Response rate (71 per cent) and age distribution (mean age 48) were similar in overweight and non-overweight groups of both sexes. BMI was correlated with the total number of complaints in women (r = 0.15) but not in men (r = 0.07). Multiple regression analysis revealed, however, that age was an effect modifier in this relation, there being a negative association between BMI and subjective health in younger men and a positive association in older men, whereas in women the association between BMI and subjective health was much more pronounced at younger ages than at older ages. In addition, current smoking habits and social class (in men and women) and reported slimming behavior (in women) had an independent relation to the total number of health complaints. BMI was also related to specific complaints and groups of complaints, particularly in women. PMID:3777287

  2. 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.

  3. 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). PMID:27661270

  4. A finite class of q-orthogonal polynomials corresponding to inverse gamma distribution

    NASA Astrophysics Data System (ADS)

    Soleyman, F.; Masjed-Jamei, M.; Area, I.

    2016-09-01

    In this paper, a class of finite q-orthogonal polynomials is studied whose weight function corresponds to the inverse gamma distribution as q → 1 . Via Sturm-Liouville theory in q-difference spaces, the orthogonality of this class is proved and its norm square value is computed. Also, its general properties such as q-weight function, q-difference equation and the basic hypergeometric representation are recovered in the continuous case.

  5. [Spatial patterns of different age-class individuals in Pinus tabulaeformis forest in Songshan Nature Reserve of Beijing, China].

    PubMed

    Niu, Li-Li; Yu, Xin-Xiao; Yue, Yong-Jie

    2008-07-01

    By the method of point pattern analysis, this paper studied the spatial patterns of different age-class individuals in the Pinus tabulaeformis forest in Songshan Nature Reserve of Beijing, and the spatial association between the individuals. The results showed that there existed greater differences in the densities of different age-class P. tabulaeformis individuals, e.g., age-class I had the density of 15 plants per hectare, while age-class III had the density of 924 plants per hectare. The spatial patterns of different age-class individuals and the spatial association between the individuals had a close relationship with the spatial scale. In the scale of < 40 m, the individuals of all age-classes tended to clump, and there was a stronger spatial association between the individuals of different age-classes. When the scale was larger than 30 m or 40 m, the individuals of all age-classes would disperse randomly, and their spatial association would be weakened greatly. PMID:18839896

  6. Circadian variation in salivary testosterone across age classes in Ache Amerindian males of Paraguay.

    PubMed

    Bribiescas, Richard G; Hill, Kim R

    2010-01-01

    Testosterone levels exhibit a circadian rhythm in healthy men, with morning levels tending to be higher compared to evening titers. However, circadian rhythms wane with age. Although this has been described in males living within industrialized settings, age-related changes have not received similar attention in populations outside these contexts. Because many nonindustrialized populations, such as Ache Amerindians of Paraguay, exhibit testosterone levels that are lower than what is commonly reported in the clinical literature and lack age-associated variation in testosterone, it was hypothesized that Ache men would not show age-related variation in testosterone circadian rhythms. Diurnal rhythmicity in testosterone within and between Ache men in association with age (n = 52; age range, 18-64) was therefore examined. A significant negative association was evident between the ratio of morning and evening salivary testosterone and age (r = -0.28, P = 0.04). Men in their third decade of life exhibited significant diurnal variation (P = 0.0003), whereas older and younger age classes did not. Men between the ages of 30 and 39 also exhibited a higher AM:PM testosterone ratio compared to 40-49 and 50< year old men (P = 0.002, 0.006). Overall, declines in testosterone with aging may not be universal among human males, however, within-individual analyses of diurnal variation capture age-related contrasts in daily testosterone fluctuations. Circadian rhythmicity differs with age among the Ache and may be a common aspect of reproductive senescence among men regardless of ecological context.

  7. Aged Boreal Biomass Burning Size Distributions from Bortas 2011

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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 strong 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 concentrations and forcing estimates derived from these models. The BORTAS-B 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 ~ 1.5 - 2 days) from boreal wildfires in Northwestern Ontario. The composite median size-distribution yields a single dominant accumulation mode with Dpm = 232 nm, σ = 1.7, 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 0.08-0.18 μg m-3 ppbv-1 with no significant trend with distance from the source. This lack of enhancement ratio increase/decrease with distance suggests no detectable net OA production/evaporation within the aged plume over the sampling period. A Lagrangian microphysical model was used to determine an estimate of the freshly emitted size distribution and flux corresponding to the BORTAS-B aged size-distributions. The model was restricted to coagulation and dilution processes only based on the insignificant net OA production/evaporation derived from the ΔOA/ΔCO enhancement ratios. Depending on the, we estimate that the fresh-plume median diameter was in the range of 59-94 nm with modal widths in the range of 1.7-2.8. Thus, the size of the freshly emitted particles is somewhat unconstrained due to the uncertainties in the plume dilution rates.

  8. 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.

    2014-09-01

    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 concentrations and forcing estimates derived from these models. The BORTAS-B 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), σ = 1.7, 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 0.05-0.18 μg m-3 ppbv-1 with no significant trend with distance from the source. This lack of enhancement ratio increase/decrease with distance suggests no detectable net OA production/evaporation within the aged plume over the sampling period. 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 estimate that the fresh-plume median diameter was in the range of 59-94 nm with modal widths in the range of 1.7-2.8 (the ranges are due to uncertainty in the entrainment rate). Thus, the size of the freshly emitted particles is relatively unconstrained due to the uncertainties in

  9. Age related distributive justice and claims on resources.

    PubMed

    Irwin, S

    1996-03-01

    The ageing population structure, and claims on resources by non-working groups, are seen by many to be contributing to a growing welfare crisis. In their arguments, relations between age groups and generations will become increasingly fraught, and welfare arrangements will be undermined, as 'unacceptable' levels of taxation blight the experience of a contracting workforce, required to resource a growing welfare population. However, more seems to be known about researchers' views on distributive justice than is known about the perceptions of their subject populations. It has not been demonstrated that members of age groups share interests which are consonant with their cohort experience, or perceive their interests to be in conflict with those members of other age groups or generations. This paper analyses empirical evidence on people's perceptions of who should get, and do, what, in developing an argument that standard processes do not place age groups or generations in antagonistic relationship. Understanding the relations between age groups and generations is essential to explaining change in patterns of inequality, but the interdependence of these relations suggest that they are part of a coherent social structure, and not likely to give rise to crisis in the ways predicted.

  10. Unimodal tree size distributions possibly result from relatively strong conservatism in intermediate size classes.

    PubMed

    Bin, Yue; Ye, Wanhui; Muller-Landau, Helene C; Wu, Linfang; Lian, Juyu; Cao, Honglin

    2012-01-01

    Tree size distributions have long been of interest to ecologists and foresters because they reflect fundamental demographic processes. Previous studies have assumed that size distributions are often associated with population trends or with the degree of shade tolerance. We tested these associations for 31 tree species in a 20 ha plot in a Dinghushan south subtropical forest in China. These species varied widely in growth form and shade-tolerance. We used 2005 and 2010 census data from that plot. We found that 23 species had reversed J shaped size distributions, and eight species had unimodal size distributions in 2005. On average, modal species had lower recruitment rates than reversed J species, while showing no significant difference in mortality rates, per capita population growth rates or shade-tolerance. We compared the observed size distributions with the equilibrium distributions projected from observed size-dependent growth and mortality. We found that observed distributions generally had the same shape as predicted equilibrium distributions in both unimodal and reversed J species, but there were statistically significant, important quantitative differences between observed and projected equilibrium size distributions in most species, suggesting that these populations are not at equilibrium and that this forest is changing over time. Almost all modal species had U-shaped size-dependent mortality and/or growth functions, with turning points of both mortality and growth at intermediate size classes close to the peak in the size distribution. These results show that modal size distributions do not necessarily indicate either population decline or shade-intolerance. Instead, the modal species in our study were characterized by a life history strategy of relatively strong conservatism in an intermediate size class, leading to very low growth and mortality in that size class, and thus to a peak in the size distribution at intermediate sizes. PMID:23300714

  11. 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. PMID:26251058

  12. 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.

  13. 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.

  14. Evaluation of bursal depth as an indicator of age class of harlequin ducks

    USGS Publications Warehouse

    Mather, D.D.; Esler, Daniel

    1999-01-01

    We contrasted the estimated age class of recaptured Harlequin Ducks (Histrionicus histrionicus) (n = 255) based on bursal depth with expected age class based on bursal depth at first capture and time since first capture. Although neither estimated nor expected ages can be assumed to be correct, rates of discrepancies between the two for within-year recaptures indicate sampling error, while between-year recaptures test assumptions about rates of bursal involution. Within-year, between-year, and overall discrepancy rates were 10%, 24%, and 18%, respectively. Most (86%) between-year discrepancies occurred for birds expected to be after-third-year (ATY) but estimated to be third-year (TY). Of these ATY-TY discrepancies, 22 of 25 (88%) birds had bursal depths of 2 or 3 mm. Further, five of six between-year recaptures that were known to be ATY but estimated to be TY had 2 mm bursas. Reclassifying birds with 2 or 3 mm bursas as ATY resulted in reduction in between-year (24% to 10%) and overall (18% to 11%) discrepancy rates. We conclude that age determination of Harlequin Ducks based on bursal depth, particularly using our modified criteria, is a relatively consistent and reliable technique.

  15. Pathogens and Indicators in United States Class B Biosolids: National and Historic Distributions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reports on the first major study of the incidence of indicator organisms and pathogens found within Class B biosolids across the U.S. since the promulgation of the EPA Part 503 Rule in 1993. National distributions collected between 2005 and 2008, show that the incidence of bacterial and v...

  16. Effects of predation and oxygen deficiency on different age classes of the amphipod Monoporeia affinis

    NASA Astrophysics Data System (ADS)

    Sandberg, E.; Bonsdorff, E.

    1996-06-01

    Predation by the big brackish-water isopod Saduria entomon on two age-classes (juveniles and adults) of the small deposit-feeding amphipod Monoporeia (syn. Pontoporeia) affinis was studied at different oxygen conditions (normoxia>11 mg/l O 2, and moderate hypoxia 4 mg/l O 2). Vulnerability of juvenile and adult M. affinis was studied in single and mixed age-class treatments. The proportions of juveniles and adults were varied at one total numerical density. The predatory effects were measured as numbers of individuals consumed and of total biomass intake (mg ash-free dry weight). The highest predation rate (in numbers) was detected in the single-prey treatment with juvenile M. affinis, both in normoxia and moderate hypoxia. No preference for any of the two size classes was found in the treatment with equal numbers of adults and juveniles. In normoxia, the total number of prey consumed decreased with increasing proportions of adults, while intake increased in terms of biomass. In moderate hypoxia, high proportions of adults reduced the predation rate of S. entomon to such an extent that also the intake in terms of biomass was significantly negatively affected.

  17. Age changes in the distribution of visual attention.

    PubMed

    McCalley, L T; Bouwhuis, D G; Juola, J F

    1995-11-01

    Two experiments examined adult age differences in the controlled allocation of visual selective attention. Both experiments were identical with the exception of the stimulus display where targets and distractors were linearly increased with eccentricity in Experiment 2. A spatial cuing task was used with four cue-target presentation intervals (SOAs) of 250, 500, 1000, and 2000 msec (Experiment 1) and 250, 500, 750, and 1000 msec (Experiment 2). Results were fit to three quantitative models based on attentional distribution metaphors (spotlight, zoom lens, and ring) in order to determine the best fitting model of attentional distribution. Data from Experiment 1 indicated that older subjects distributed attention in a qualitatively different manner than younger subjects and suggested a different time course of processing. When stimuli visibility was controlled a single flexible resource allocation (ring) model of attention could account for the results of both age groups at all SOAs. Results further suggested that older adults employ compensatory strategies to offset visual processing difficulties. PMID:7583811

  18. Mass/age distribution of organic carbon for the Phanerozoic

    SciTech Connect

    Hay, W.W.; Wold, C.N. Geomar, Kiel )

    1991-03-01

    The mass/age distribution of organic carbon in Phanerozoic sedimentary rocks is dominated by disseminated organic carbon in pelitic rocks. Even during the major times of coal formation, the mass of organic carbon in coal is small compared with that included in fine-grained marine sediments. The mass/age distribution shows maxima in the Middle and Late Ordovician, Late Devonian, Late Jurassic and Early Cretaceous, and Neogene. Minima in accumulation of organic carbon mark the Early Ordovician, Early Devonian, Permian and Triassic, Late Cretaceous and Paleogene. Reconstruction of the ancient fluxes of organic carbon into the sediments shows that the distribution is almost symmetrical about the Paleozoic-Mesozoic boundary. Major hydrocarbon source rock accumulations coincide with peaks of organic carbon deposition, but modes of formation of the source rocks at each peak may have been different. The peaks of organic carbon accumulation correspond to times of flooding of the continents. The Ordovician, Late Jurassic-Early Cretaceous peaks also correspond to an increase in the ratio of carbon being deposited as organic carbon relative to that deposited as carbonate; they also correspond to times of deposition of large amounts of siliceous sediment. The Lake Devonian peak also formed at a time of flooding of the continents, but shows a low ratio of organic carbon to carbonate, and few siliceous rocks accumulated contemporaneously. The Neogene peak may represent a fundamentally different accumulation mechanism, resulting mostly from coastal upwelling during a time of emergence of the continents.

  19. Sweepnet captures of Lygus hesperus (Hemiptera:Miridae) adult genders and age-classes in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management of the western tarnished plant bug, Lygus hesperus Knight, in cotton usually relies on population estimates obtained using the sweepnet. Recent studies indicated adult L. hesperus gender and physiological age influence feeding behavior, within-plant distribution, and injury to cotton. W...

  20. Restoration of Retarded Influenza Virus-specific Immunoglobulin Class Switch in Aged Mice

    PubMed Central

    Zhang, Yongxin; Wang, Ying; Zhang, Monica; Liu, Lin; Mbawuike, Innocent N

    2016-01-01

    Objective The declined immune response to infection causes significant higher morbidity and mortality in aging in spite of the coexisted hyperimmunoglobulinemia (HIG). This study is to reveal the cellular basis of HIG and mechanism of weakened HA-specific IgG response in aged mice and to test cell therapy in the treatment of age-related IgG antibody production deficiency with immunocyte adoptive transfer. Methods BALB/c mice was immunized with Influenza A/Taiwan vaccine and challenged with the same strain of virus. ELISA was used to assess the levels of total immunoglobulins and antigen specific antibody response. The flow cytometry and ELISPOT were used to evaluate the frequencies of total immunoglobulin- and specific antibody-producing and secreting B lymphocytes. In vitro expanded mononuclear cells, CD4+ T lymphocytes and CD20+ B lymphocytes from old and young mice were adoptively transferred into influenza virus-challenged aged mice, and HA-specific IgG responses were observed. Results It is found that old mice exhibited higher levels of total serum IgG, IgM and IgA, higher frequencies of IgG+, IgM+ and IgA+ cells, and greater antigen-specific IgM and IgA responses to influenza infection, in comparison to young mice. However, influenza antigen- specific IgG and its subclass responses in old mice were significantly lower. Conclusion The retarded specific IgG response could be attributed to an insufficiency of immunoglobulin class switch in aging. Correlation analysis indicated that HIG and deficient specific IgG production in aged mice could be independent to each other in their pathogenesis. Correction of deficient specific IgG production by adoptive transfer of in vitro expanded and unexpanded CD4+ cells from immunized young mice suggests the CD4+ cell dysfunction contributes to the insufficiency of immunoglobulin class switch in aged mice. The transfusion of in vitro expanded lymphocytes could be a potential effective therapy for the age

  1. Multichannel imaging to quantify four classes of pharmacokinetic distribution in tumors

    PubMed Central

    Bhatnagar, Sumit; Deschenes, Emily; Liao, Jianshan; Cilliers, Cornelius; Thurber, Greg M.

    2014-01-01

    Low and heterogeneous delivery of drugs and imaging agents to tumors results in decreased efficacy and poor imaging results. Systemic delivery involves a complex interplay of drug properties and physiological factors, and heterogeneity in the tumor microenvironment makes predicting and overcoming these limitations exceptionally difficult. Theoretical models have indicated that there are four different classes of pharmacokinetic behavior in tissue, depending on the fundamental steps in distribution. In order to study these limiting behaviors, we used multichannel fluorescence microscopy and stitching of high-resolution images to examine the distribution of four agents in the same tumor microenvironment. A validated generic partial differential equation model with a graphical user interface was used to select fluorescent agents exhibiting these four classes of behavior, and the imaging results agreed with predictions. BODIPY-FL exhibited higher concentrations in tissue with high blood flow, cetuximab gave perivascular distribution limited by permeability, high plasma protein and target binding resulted in diffusion-limited distribution for Hoechst 33342, and Integrisense 680 was limited by the number of binding sites in the tissue. Together, the probes and simulations can be used to investigate distribution in other tumor models, predict tumor drug distribution profiles, and design and interpret in vivo experiments. PMID:25048378

  2. Multichannel imaging to quantify four classes of pharmacokinetic distribution in tumors.

    PubMed

    Bhatnagar, Sumit; Deschenes, Emily; Liao, Jianshan; Cilliers, Cornelius; Thurber, Greg M

    2014-10-01

    Low and heterogeneous delivery of drugs and imaging agents to tumors results in decreased efficacy and poor imaging results. Systemic delivery involves a complex interplay of drug properties and physiological factors, and heterogeneity in the tumor microenvironment makes predicting and overcoming these limitations exceptionally difficult. Theoretical models have indicated that there are four different classes of pharmacokinetic behavior in tissue, depending on the fundamental steps in distribution. In order to study these limiting behaviors, we used multichannel fluorescence microscopy and stitching of high-resolution images to examine the distribution of four agents in the same tumor microenvironment. A validated generic partial differential equation model with a graphical user interface was used to select fluorescent agents exhibiting these four classes of behavior, and the imaging results agreed with predictions. BODIPY-FL exhibited higher concentrations in tissue with high blood flow, cetuximab gave perivascular distribution limited by permeability, high plasma protein and target binding resulted in diffusion-limited distribution for Hoechst 33342, and Integrisense 680 was limited by the number of binding sites in the tissue. Together, the probes and simulations can be used to investigate distribution in other tumor models, predict tumor drug distribution profiles, and design and interpret in vivo experiments. PMID:25048378

  3. Differential Range Use between Age Classes of Southern African Bearded Vultures Gypaetus barbatus

    PubMed Central

    Krüger, Sonja; Reid, Timothy; Amar, Arjun

    2014-01-01

    Bearded Vulture Gypaetus barbatus movements were investigated in southern Africa to determine whether an individual's age, sex or breeding status influenced its ranging behaviour and to provide the information required to guide conservation activities. Data from satellite transmitters fitted to 18 individuals of four age classes were used to determine range size and use. Because of the nature of the movements of marked individuals, these data could be used to determine the overall foraging range of the entire population, which was estimated to be 51 767 km2. Although juvenile, immature and sub-adult birds used different parts of the overall range, their combined foraging range was 65% (33 636 km2) of the overall range. Average adult home ranges (286 km2) were only around 1% the size of the average foraging ranges of non-adults (10 540 –25 985 km2), with those of breeding adults being even smaller (95 km2). Home ranges of breeding adults did not vary in size between seasons but adults utilized their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period. Range size and use increased as non-adults aged. Immatures and sub-adults had larger range sizes during winter, but range use of non-adults did not vary seasonally. Range size and use did not differ between the sexes in any of the age classes. Information on home range size and use enables specific areas within the species' range to be targeted for management planning, education and conservation action. PMID:25551614

  4. Differential range use between age classes of southern African Bearded Vultures Gypaetus barbatus.

    PubMed

    Krüger, Sonja; Reid, Timothy; Amar, Arjun

    2014-01-01

    Bearded Vulture Gypaetus barbatus movements were investigated in southern Africa to determine whether an individual's age, sex or breeding status influenced its ranging behaviour and to provide the information required to guide conservation activities. Data from satellite transmitters fitted to 18 individuals of four age classes were used to determine range size and use. Because of the nature of the movements of marked individuals, these data could be used to determine the overall foraging range of the entire population, which was estimated to be 51 767 km(2). Although juvenile, immature and sub-adult birds used different parts of the overall range, their combined foraging range was 65% (33 636 km(2)) of the overall range. Average adult home ranges (286 km(2)) were only around 1% the size of the average foraging ranges of non-adults (10 540 -25 985 km(2)), with those of breeding adults being even smaller (95 km(2)). Home ranges of breeding adults did not vary in size between seasons but adults utilized their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period. Range size and use increased as non-adults aged. Immatures and sub-adults had larger range sizes during winter, but range use of non-adults did not vary seasonally. Range size and use did not differ between the sexes in any of the age classes. Information on home range size and use enables specific areas within the species' range to be targeted for management planning, education and conservation action. PMID:25551614

  5. Differential range use between age classes of southern African Bearded Vultures Gypaetus barbatus.

    PubMed

    Krüger, Sonja; Reid, Timothy; Amar, Arjun

    2014-01-01

    Bearded Vulture Gypaetus barbatus movements were investigated in southern Africa to determine whether an individual's age, sex or breeding status influenced its ranging behaviour and to provide the information required to guide conservation activities. Data from satellite transmitters fitted to 18 individuals of four age classes were used to determine range size and use. Because of the nature of the movements of marked individuals, these data could be used to determine the overall foraging range of the entire population, which was estimated to be 51 767 km(2). Although juvenile, immature and sub-adult birds used different parts of the overall range, their combined foraging range was 65% (33 636 km(2)) of the overall range. Average adult home ranges (286 km(2)) were only around 1% the size of the average foraging ranges of non-adults (10 540 -25 985 km(2)), with those of breeding adults being even smaller (95 km(2)). Home ranges of breeding adults did not vary in size between seasons but adults utilized their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period. Range size and use increased as non-adults aged. Immatures and sub-adults had larger range sizes during winter, but range use of non-adults did not vary seasonally. Range size and use did not differ between the sexes in any of the age classes. Information on home range size and use enables specific areas within the species' range to be targeted for management planning, education and conservation action.

  6. Distribution of a Population of Rhizobium leguminosarum bv. trifolii among Different Size Classes of Soil Aggregates.

    PubMed

    Mendes, I C; Bottomley, P J

    1998-03-01

    A combination of the plant infection-soil dilution technique (most-probable-number [MPN] technique) and immunofluorescence direct count (IFDC) microscopy was used to examine the effects of three winter cover crop treatments on the distribution of a soil population of Rhizobium leguminosarum bv. trifolii across different size classes of soil aggregates (<0.25, 0.25 to 0.5, 0.5 to 1.0, 1.0 to 2.0, and 2.0 to 5.0 mm). The aggregates were prepared from a Willamette silt loam soil immediately after harvest of broccoli (September 1995) and before planting and after harvest of sweet corn (June and September 1996, respectively). The summer crops were grown in soil that had been either fallowed or planted with a cover crop of red clover (legume) or triticale (cereal) from September to April. The Rhizobium soil population was heterogeneously distributed across the different size classes of soil aggregates, and the distribution was influenced by cover crop treatment and sampling time. On both September samplings, the smallest size class of aggregates (<0.25 mm) recovered from the red clover plots carried between 30 and 70% of the total nodulating R. leguminosarum population, as estimated by the MPN procedure, while the same aggregate size class from the June sampling carried only approximately 6% of the population. In June, IDFC microscopy revealed that the 1.0- to 2.0-mm size class of aggregates from the red clover treatment carried a significantly greater population density of the successful nodule-occupying serotype, AR18, than did the aggregate size classes of <0.5 mm, and 2 to 5 mm. In September, however, the population profile of AR18 had shifted such that the density was significantly greater in the 0.25- to 0.5-mm size class than in aggregates of <0.25 mm and >1.0 mm. The populations of two other Rhizobium serotypes (AR6 and AS36) followed the same trends of distribution in the June and September samplings. These data indicate the existence of structural microsites

  7. Age Differences Explain Social Class Differences in Students' Friendship at University: Implications for Transition and Retention

    ERIC Educational Resources Information Center

    Rubin, Mark; Wright, Chrysalis L.

    2015-01-01

    The present research tested the hypotheses that (a) working-class students have fewer friends at university than middle-class students and (b) this social class difference occurs because working-class students tend to be older than middle-class students. A sample of 376 first-year undergraduate students from an Australian university completed an…

  8. Microcystin distribution in physical size class separations of natural plankton communities

    USGS Publications Warehouse

    Graham, J.L.; Jones, J.R.

    2007-01-01

    Phytoplankton communities in 30 northern Missouri and Iowa lakes were physically separated into 5 size classes (>100 ??m, 53-100 ??m, 35-53 ??m, 10-35 ??m, 1-10 ??m) during 15-21 August 2004 to determine the distribution of microcystin (MC) in size fractionated lake samples and assess how net collections influence estimates of MC concentration. MC was detected in whole water (total) from 83% of takes sampled, and total MC values ranged from 0.1-7.0 ??g/L (mean = 0.8 ??g/L). On average, MC in the > 100 ??m size class comprised ???40% of total MC, while other individual size classes contributed 9-20% to total MC. MC values decreased with size class and were significantly greater in the >100 ??m size class (mean = 0.5 ??g /L) than the 35-53 ??m (mean = 0.1 ??g/L), 10-35 ??m (mean = 0.0 ??g/L), and 1-10 ??m (mean = 0.0 ??g/L) size classes (p < 0.01). MC values in nets with 100-??m, 53-??m, 35-??m, and 10-??m mesh were cumulatively summed to simulate the potential bias of measuring MC with various size plankton nets. On average, a 100-??m net underestimated total MC by 51%, compared to 37% for a 53-??m net, 28% for a 35-??m net, and 17% for a 10-??m net. While plankton nets consistently underestimated total MC, concentration of algae with net sieves allowed detection of MC at low levels (???0.01 ??/L); 93% of lakes had detectable levels of MC in concentrated samples. Thus, small mesh plankton nets are an option for documenting MC occurrence, but whole water samples should be collected to characterize total MC concentrations. ?? Copyright by the North American Lake Management Society 2007.

  9. Distributed fault diagnosis in a class of interconnected nonlinear uncertain systems

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaodong; Zhang, Qi

    2012-11-01

    In this article, a distributed fault detection and isolation (FDI) method is developed for a class of interconnected nonlinear uncertain systems. In the distributed FDI architecture, a FDI component is designed for each subsystem in the interconnected system. For each subsystem, its corresponding local FDI component is designed by utilising local measurements and certain communicated information from neighbouring FDI components associated with subsystems that are directly interconnected to the particular subsystem under consideration. Under certain assumptions, adaptive thresholds for distributed FDI in each subsystem are derived, ensuring robustness with respect to interactions among subsystems and system modelling uncertainty. Moreover, the fault detectability and isolability conditions are rigorously investigated, characterising the class of faults in each subsystem that are detectable and isolable by the proposed distributed FDI method. Additionally, the stability and learning capability of the local adaptive fault isolation estimators designed for each subsystem is established. A simulation example of interconnected inverted pendulums mounted on carts is used to illustrate the effectiveness of the method.

  10. A class of multivariate distribution-free tests of independence based on graphs

    PubMed Central

    Gorfine, M.; Heller, Y.

    2013-01-01

    A class of distribution-free tests is proposed for the independence of two subsets of response coordinates. The tests are based on the pairwise distances across subjects within each subset of the response. A complete graph is induced by each subset of response coordinates, with the sample points as nodes and the pairwise distances as the edge weights. The proposed test statistic depends only on the rank order of edges in these complete graphs. The response vector may be of any dimensions. In particular, the number of samples may be smaller than the dimensions of the response. The test statistic is shown to have a normal limiting distribution with known expectation and variance under the null hypothesis of independence. The exact distribution free null distribution of the test statistic is given for a sample of size 14, and its Monte-Carlo approximation is considered for larger sample sizes. We demonstrate in simulations that this new class of tests has good power properties for very general alternatives. PMID:23956488

  11. Aging IQ Intervention with Older Korean Americans: A Comparison of Internet-Based and In-Class Education

    ERIC Educational Resources Information Center

    Jang, Yuri; Yoon, Hyunwoo; Marti, C. Nathan; Kim, Miyong T.

    2015-01-01

    Using the translated contents of the National Institute on Aging (NIA)'s Aging IQ, an educational intervention was delivered to older Korean Americans. The educational program was delivered via two different modalities, Internet-based education (n = 12) and in-class education (n = 11), and the overall feasibility and efficacy were evaluated by the…

  12. 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.

  13. Middle-Class Mythology in an Age of Immigration and Segmented Assimilation: Implication for Counseling Psychology

    ERIC Educational Resources Information Center

    Lee, Richard M.; Dean, Brooke L.

    2004-01-01

    W. M. Liu, S. R. Ali, et al. (2004) provide a useful framework to understand the relevance of social class to counseling psychology research, but they overlook the intersection of race and social class in their review. The authors critique the middle-class mythology that pervades social class research in psychology and introduce segmented…

  14. 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

  15. Body build classes as a method for systematization of age-related anthropometric changes in girls aged 7-8 and 17-18 years.

    PubMed

    Kasmel, Jaan; Kaarma, Helje; Koskel, Säde; Tiit, Ene-Margit

    2004-03-01

    A total of 462 schoolgirls aged 7-8 and 17-18 years were examined anthropometrically (45 body measurements and 10 skinfolds) in a cross-sectional study. The data were processed in two age groups: 7-8-year-olds (n = 205) and 17-18-year-olds (n = 257). Relying on average height and weight in the groups, both groups were divided into five body build classes: small, medium, large, pyknomorphous and leptomorphous. In these classes, the differences in all other body measurements were compared, and in both age groups, analogous systematic differences were found in length, width and depth measurements and circumferences. This enabled us to compare proportional changes in body measurements during ten years, using for this ratios of averages of basic measurements and measurement groups in the same body build classes. Statistical analysis by the sign test revealed statistically significant differences between various body build classes in the growth of averages. Girls belonging to the small class differed from the girls of the large class by an essentially greater increase in their measurements. Our results suggest that the growth rate of body measurements of girls with different body build can be studied by the help of body build classification.

  16. 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.

  17. Synthesis and biology of cyclic imine toxins, an emerging class of potent, globally distributed marine toxins.

    PubMed

    Stivala, Craig E; Benoit, Evelyne; Aráoz, Rómulo; Servent, Denis; Novikov, Alexei; Molgó, Jordi; Zakarian, Armen

    2015-03-01

    From a small group of exotic compounds isolated only two decades ago, Cyclic Imine (CI) toxins have become a major class of marine toxins with global distribution. Their distinct chemical structure, biological mechanism of action, and intricate chemistry ensures that CI toxins will continue to be the subject of fascinating fundamental studies in the broad fields of chemistry, chemical biology, and toxicology. The worldwide occurrence of potent CI toxins in marine environments, their accumulation in shellfish, and chemical stability are important considerations in assessing risk factors for human health. This review article aims to provide an account of chemistry, biology, and toxicology of CI toxins from their discovery to the present day.

  18. [Root system spatial distribution of different aged Armeniaca vulgaris cv. Luntaibaixing in arid oasis under irrigation].

    PubMed

    Wang, Shi-Wei; Pan, Cun-De

    2012-09-01

    By the methods of layered digging and image scanning analysis, this paper studied the root system spatial distribution of different aged Armeniaca vulgaris cv. Luntaibaixing in arid oasis under irrigation. The root system of A. vulgaris cv. Luntaibaixing was mainly constituted by fine roots (d < or = 1 mm), while medium roots (12 mm) only had a small proportion. For the trees aged 5-year old, 10-year old, and 15-year old, the percentage of fine root length in the total root length was 90.9%, 88.4%, and 79.9% respectively, the root length density increased with tree age, and the length density of the roots with different diameter classes was 15-year old>10-year old>5-year old. In vertical direction, the root length density decreased after an initial decrease, and the root dry mass density had a significant difference between soil layers. The intensive distribution region of the root biomass density for the trees aged 5-year old, 10-year old, and 15-year old was 30-80 cm, 30-100 cm, and 30-100 cm soil depth within the 200 cm range from the trees, respectively. In horizontal direction, the root dry mass density at different distances from the trees had significant difference, i. e., the farther the distance from the tree trunk, the smaller the root dry mass density. In order to decrease the overlap between the tree line and to reduce water and nutrient competition, the row ledge of A. vulgaris cv. Luntaibaixing in arid oasis under irrigation should not be less than 6 m. PMID:23285988

  19. [Root system spatial distribution of different aged Armeniaca vulgaris cv. Luntaibaixing in arid oasis under irrigation].

    PubMed

    Wang, Shi-Wei; Pan, Cun-De

    2012-09-01

    By the methods of layered digging and image scanning analysis, this paper studied the root system spatial distribution of different aged Armeniaca vulgaris cv. Luntaibaixing in arid oasis under irrigation. The root system of A. vulgaris cv. Luntaibaixing was mainly constituted by fine roots (d < or = 1 mm), while medium roots (12 mm) only had a small proportion. For the trees aged 5-year old, 10-year old, and 15-year old, the percentage of fine root length in the total root length was 90.9%, 88.4%, and 79.9% respectively, the root length density increased with tree age, and the length density of the roots with different diameter classes was 15-year old>10-year old>5-year old. In vertical direction, the root length density decreased after an initial decrease, and the root dry mass density had a significant difference between soil layers. The intensive distribution region of the root biomass density for the trees aged 5-year old, 10-year old, and 15-year old was 30-80 cm, 30-100 cm, and 30-100 cm soil depth within the 200 cm range from the trees, respectively. In horizontal direction, the root dry mass density at different distances from the trees had significant difference, i. e., the farther the distance from the tree trunk, the smaller the root dry mass density. In order to decrease the overlap between the tree line and to reduce water and nutrient competition, the row ledge of A. vulgaris cv. Luntaibaixing in arid oasis under irrigation should not be less than 6 m.

  20. Lipid composition of the Antarctic fish Pleuragramma antarcticum. Influence of age class

    NASA Astrophysics Data System (ADS)

    Mayzaud, P.; Chevallier, J.; Tavernier, E.; Moteki, M.; Koubbi, P.

    2011-08-01

    Larvae and juvenile stages of Pleuragramma antarcticum have been collected in the Dumont D’Urville Sea (East Antarctica) during summer 2008 on board the TRV Umitaka Maru during the CEAMARC survey. Detailed analyses of their lipid class and fatty acid compositions were carried out. P. antarcticum showed a pronounced ontogenic lipid accumulation with increasing size. Larvae displayed a dominance of polar lipids (83% of total lipids) and low percentage of triglycerides (7%). Conversely juveniles showed an increasing accumulation of triglycerides (up to 72.4%). The fatty acid composition of polar lipids remained rather stable between stages with 22:6n-3 and 20:5n-3 as dominant contributors. The relatively minor ontogenic changes, e.g. increase of monounsaturated and decrease of C18 polyunsaturated fatty acids, may reflect the influence of differences in diet. Triglycerides showed that all three age classes are well segregated in term of fatty acid composition. Larvae triglycerides are characterized by significant percentages of 16:0, 20:5n-3, 20:6n-3 and to a minor extent 18:4n-3, which suggest a prymnesiophyte based diet. Juveniles are characterized by larger percentages of C20:1 and C22:1 acids, considered as markers of Calanus type copepods. The increasing contribution of 18:1n-9 in the triglycerides of the older juveniles suggests a gradual and increasing shift from a copepod dominant diet to an euphausiid dominant diet. Fatty acid trophic markers pattern suggests a shift from a phytophagous and omnivorous diet for larvae to a carnivorous diet for juveniles.

  1. The effect of small class sizes on mortality through age 29 years: evidence from a multicenter randomized controlled trial.

    PubMed

    Muennig, Peter; Johnson, Gretchen; Wilde, Elizabeth Ty

    2011-06-15

    Limiting the number of students per classroom in the early years has been shown to improve educational outcomes. Improved education is, in turn, hypothesized to improve health. The authors examined whether smaller class sizes affect mortality through age 29 years and whether cognitive factors play a role. They used data from the Project Student Teacher Achievement Ratio, a 4-year multicenter randomized controlled trial of reduced class sizes in Tennessee involving 11,601 students between 1985 and 1989. Children randomized to small classes (13-17 students) experienced improved measures of cognition and academic performance relative to those assigned to regular classes (22-25 students). As expected, these cognitive measures were significantly inversely associated with mortality rates (P < 0.05). However, through age 29 years, students randomized to small class size nevertheless experienced higher mortality rates than those randomized to regular size classes (hazard ratio (HR) = 1.58, 95% confidence interval (CI): 1.07, 2.32). The groups at risk included males (HR = 1.73, 95% CI: 1.05, 2.85), whites/Asians (HR = 1.68, 95% CI: 1.04, 2.72), and higher income students (HR = 2.20, 95% CI: 1.06, 4.57). The authors speculate that small classes might produce behavior changes that increase mortality through young adulthood that are stronger than the protective effects of enhanced cognition. PMID:21540326

  2. The effect of small class sizes on mortality through age 29 years: evidence from a multicenter randomized controlled trial.

    PubMed

    Muennig, Peter; Johnson, Gretchen; Wilde, Elizabeth Ty

    2011-06-15

    Limiting the number of students per classroom in the early years has been shown to improve educational outcomes. Improved education is, in turn, hypothesized to improve health. The authors examined whether smaller class sizes affect mortality through age 29 years and whether cognitive factors play a role. They used data from the Project Student Teacher Achievement Ratio, a 4-year multicenter randomized controlled trial of reduced class sizes in Tennessee involving 11,601 students between 1985 and 1989. Children randomized to small classes (13-17 students) experienced improved measures of cognition and academic performance relative to those assigned to regular classes (22-25 students). As expected, these cognitive measures were significantly inversely associated with mortality rates (P < 0.05). However, through age 29 years, students randomized to small class size nevertheless experienced higher mortality rates than those randomized to regular size classes (hazard ratio (HR) = 1.58, 95% confidence interval (CI): 1.07, 2.32). The groups at risk included males (HR = 1.73, 95% CI: 1.05, 2.85), whites/Asians (HR = 1.68, 95% CI: 1.04, 2.72), and higher income students (HR = 2.20, 95% CI: 1.06, 4.57). The authors speculate that small classes might produce behavior changes that increase mortality through young adulthood that are stronger than the protective effects of enhanced cognition.

  3. The distribution of compositional classes in the asteroid belt: A cosmochemical fingerprint?

    NASA Technical Reports Server (NTRS)

    Gradie, J.

    1985-01-01

    Studies of the physical properties of the asteroids show a nonrandom distribution of types across the belt for asteroid classes E, S, M, F, C, P, and D. The general trend is for asteroids in the inner belt to have higher albedos and stronger mafic silicate absorption features than those asteroids located further out in the belt. One interpretation of this trend is that the asteroids, which occupy the region between the silicate rich terrestrial planets and the volatile rich outer planets, have preserved in their heliocentric compositional distribution a cosmochemical fingerprint of the thermodynamic conditions present in the solar nebula at the time of their formation. This hypothesis predicts that the differences in the spectral properties among the low albedo classes (C, P, F, P, and D) are due to temperature controlled processes which formed carbonaceous opaques. If this is true then the exact composition of the opaque components could, in principle, be used to determine the thermodynamic conditions between the orbits of Mars and Jupiter during the formation of the asteroids.

  4. Opportunities for injury reduction in US frontal crashes: an overview by structural engagement, vehicle class, and occupant age.

    PubMed

    Samaha, Randa Radwan; Prasad, Priya; Nix, Lilly

    2013-11-01

    An overview NASS study of US frontal crashes was performed to investigate crash involvement, driver injury distributions and rates in airbag equipped vehicles by vehicle class and structural engagement. Frontal crash bins were based on taxonomy of structural engagement, i.e., Full Engagement, Offset, Between Rails and Corner impact crashes. A new classification of Corner impacts included frontal small overlap impacts with side damage as coded by NASS CDS. Belted drivers of two age groups, between 16 and 50 and over 50 years old, were considered. Vehicles were grouped into light and heavy passenger cars and lights trucks, and vans. A method to identify and address overly influential NASS weights was developed based on considerations of weighting factor statistics. The new taxonomy, with an expanded definition of corner impacts, allowed a more comprehensive classification of frontal crash modes. Results highlight the need to address upper extremities injuries and to better address lower extremities injuries for both the younger and older drivers. For all body regions studied, the vast majority of all serious and moderate injuries occurred in Full Engagement and Offset crash modes for both the younger and older drivers. Corner impacts, which have been the focus of recent research and testing programs, are the smallest contributors to serious and moderate injuries in frontal crashes. Greater opportunities to mitigate injuries in frontal crashes for vehicles have been shown to exist in lower speed full frontal and offset crash modes.

  5. Classes of Multivariate Exponential and Multivariate Geometric Distributions Derived from Markov Processes. Program Statistics Research Technical Report No. 89-87.

    ERIC Educational Resources Information Center

    Longford, Nicholas T.

    A class of multivariate exponential distributions is defined as the distributions of occupancy times in upwards skip-free Markov processes in continuous time. These distributions are infinitely divisible, and the multivariate gamma class defined by convolutions and fractions is a substantial generalization of the class defined by N. L. Johnson and…

  6. Age, occupational class and sickness absence during pregnancy: a retrospective analysis study of the Norwegian population registry

    PubMed Central

    Ariansen, Anja M S

    2014-01-01

    Objective Western women increasingly delay having children to advance their career, and pregnancy is considered to be riskier among older women. In Norway, this development surprisingly coincides with increased sickness absence among young pregnant women, rather than their older counterparts. This paper tests the hypothesis that young pregnant women have a higher number of sick days because this age group includes a higher proportion of working class women, who are more prone to sickness absence. Design A zero-inflated Poisson regression was conducted on the Norwegian population registry. Participants All pregnant employees giving birth in 2004–2008 were included in the study. A total number of 216 541 pregnancies were observed among 180 483 women. Outcome measure Number of sick days. Results Although the association between age and number of sick days was U-shaped, pregnant women in their early 20s had a higher number of sick days than those in their mid-40s. This was particularly the case for pregnant women with previous births. In this group, 20-year-olds had 12.6 more sick days than 45-year-olds; this age difference was reduced to 6.3 after control for class. Among women undergoing their first pregnancy, 20-year-olds initially had 1.2 more sick days than 45-year-olds, but control for class altered this age difference. After control for class, 45-year-old first-time pregnant women had 2.9 more sick days than 20-year-olds with corresponding characteristics. Conclusions The negative association between age and sickness absence was partly due to younger age groups including more working class women, who were more prone to sickness absence. Young pregnant women's needs for job adjustments should not be underestimated. PMID:24793246

  7. Predictors of Adult Men's Gender-Role Conflict: Race, Class, Unemployment, Age, Instrumentality-Expressiveness, and Personal Strain.

    ERIC Educational Resources Information Center

    Stillson, Richard W.; And Others

    1991-01-01

    Men (n=134) of different ages, races, classes, personality characteristics, and work statuses were assessed with Gender Role Conflict Scale, Personal Strain Questionnaire, and Personal Attributes Questionnaire. Two meaningful and independent male constellations linking 9 of 13 demographic, psychological, and strain variables with 3 patterns of…

  8. 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.

  9. Discriminating different classes of biological networks by analyzing the graphs spectra distribution.

    PubMed

    Takahashi, Daniel Yasumasa; Sato, João Ricardo; Ferreira, Carlos Eduardo; Fujita, André

    2012-01-01

    The brain's structural and functional systems, protein-protein interaction, and gene networks are examples of biological systems that share some features of complex networks, such as highly connected nodes, modularity, and small-world topology. Recent studies indicate that some pathologies present topological network alterations relative to norms seen in the general population. Therefore, methods to discriminate the processes that generate the different classes of networks (e.g., normal and disease) might be crucial for the diagnosis, prognosis, and treatment of the disease. It is known that several topological properties of a network (graph) can be described by the distribution of the spectrum of its adjacency matrix. Moreover, large networks generated by the same random process have the same spectrum distribution, allowing us to use it as a "fingerprint". Based on this relationship, we introduce and propose the entropy of a graph spectrum to measure the "uncertainty" of a random graph and the Kullback-Leibler and Jensen-Shannon divergences between graph spectra to compare networks. We also introduce general methods for model selection and network model parameter estimation, as well as a statistical procedure to test the nullity of divergence between two classes of complex networks. Finally, we demonstrate the usefulness of the proposed methods by applying them to (1) protein-protein interaction networks of different species and (2) on networks derived from children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) and typically developing children. We conclude that scale-free networks best describe all the protein-protein interactions. Also, we show that our proposed measures succeeded in the identification of topological changes in the network while other commonly used measures (number of edges, clustering coefficient, average path length) failed.

  10. Buying into the Computer Age: A Look at the Hispanic Middle Class.

    ERIC Educational Resources Information Center

    Wilhelm, Anthony G.

    The Tomas Rivera Policy Institute conducted focus groups in the summer of 1997 to gain insight into why there is a gap in computer ownership between Hispanic middle-class families and non-Hispanic families of the same middle class income bracket (between 25 and 50 thousand dollars). Results from 6 focus groups of 15 to 20 heads of household each…

  11. 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

  12. A new class of solutions of compact stars with charged distributions on pseudo-spheroidal spacetime

    NASA Astrophysics Data System (ADS)

    Thomas, V. O.; Pandya, D. M.

    2015-12-01

    In this paper a new class of exact solutions of Einstein's field equations for compact stars with charged distributions is obtained on the basis of pseudo-spheroidal spacetime characterized by the metric potential g_{rr}=1+K{r2/R2}/{1+r2/R2}, where K and R are geometric parameters of the spacetime. The expressions for radial pressure (pr) and electric field intensity (E) are chosen in such a way that the model falls in the category of physically acceptable one. The bounds of geometric parameter K and the physical parameters p0 and α are obtained by imposing the physical requirements and regularity conditions. The present model is in good agreement with the observational data of various compact stars like 4U 1820-30, PSR J1903+327, 4U 1608-52, Vela X-1, SMC X-4, Cen X-3 given by Gangopadhyay et al. (Mon. Not. R. Astron. Soc. 431:3216, 2013). When α = 0, the model reduces to the uncharged anisotropic distribution given by Thomas and Pandya (arXiv:1506.08698v1 [gr-qc], 2015).

  13. A new class of solutions of anisotropic charged distributions on pseudo-spheroidal spacetime

    NASA Astrophysics Data System (ADS)

    Ratanpal, B. S.; Thomas, V. O.; Pandya, D. M.

    2015-12-01

    In the present article a new class of exact solutions of Einstein's field equations for charged anisotropic distribution is obtained on the background of pseudo-spheroidal spacetime characterized by the metric potential g_{rr}=1+K {r2/R2}/{1+r2/R2}, where K and R are geometric parameters of the spacetime. The radial pressure pr and electric field intensity E are taken in the form 8π pr=K-1/R2 (1-{r2/R2)}/{ (1+Kr2/R2 )2} and E2=α(K-1){r2/R2}/{R2 (1+Kr2/R2 )2}. The bounds of geometric parameter K and the parameter α appearing in the expression of E2 are obtained by imposing the requirements for a physically acceptable model. It is found that the model is in good agreement with the observational data of number of compact stars like 4U 1820-30, PSR J1903+327, 4U 1608-52, Vela X-1, PSR J1614-2230, Cen X-3 given by Gangopadhyay et al. (Mon. Not. R. Astron. Soc. 431:3216, 2013). When α= 0, the model reduces to the uncharged anisotropic distribution given by Ratanpal et al. (arXiv:1506.08512 [gr-qc], 2015).

  14. 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.

  15. Spatial distribution of the human enamel fracture toughness with aging.

    PubMed

    Zheng, Qinghua; Xu, Haiping; Song, Fan; Zhang, Lan; Zhou, Xuedong; Shao, Yingfeng; Huang, Dingming

    2013-10-01

    A better understanding of the fracture toughness (KIC) of human enamel and the changes induced by aging is important for the clinical treatment of teeth cracks and fractures. We conducted microindentation tests and chemical content measurements on molar teeth from "young" (18 ≤ age ≤ 25) and "old" (55 ≤ age) patients. The KIC and the mineral contents (calcium and phosphorus) in the outer, the middle, and the inner enamel layers within the cuspal and the intercuspal regions of the crown were measured through the Vickers toughness test and Energy Dispersive X-Ray Spectroscopy (EDS), respectively. The elastic modulus used for the KIC calculation was measured through atomic force microscope (AFM)-based nanoindentation tests. In the outer enamel layer, two direction-specific values of the KIC were calculated separately (direction I, crack running parallel to the occlusal surface; direction II, perpendicular to direction I). The mean KIC of the outer enamel layer was lower than that of the internal layers (p<0.05). No other region-related differences in the mechanical properties were found in both groups. In the outer enamel layer, old enamel has a lower KIC, II and higher mineral contents than young enamel (p<0.05). The enamel surface becomes more prone to cracks with aging partly due to the reduction in the interprismatic organic matrix observed with the maturation of enamel.

  16. Two-Class Structure of Income Distribution in the Usa:. Exponential Bulk and Power-Law Tail

    NASA Astrophysics Data System (ADS)

    Yakovenko, V. M.; Silva, A. Christian

    2007-07-01

    Personal income distribution in the USA has a well-defined two-class structure. The majority of population (97-99 %) belongs to the lower class characterized by the exponential Boltzmann-Gibbs ("thermal") distribution, whereas the upper class (1-3 % of population) has a Pareto power-law ("superthermal") distribution. By analyzing income data for 1983-2001, we show that the "thermal" part is stationary in time, save for a gradual increase of the effective temperature, whereas the "superthermal" tail swells and shrinks following the stock market. We discuss the concept of equilibrium inequality in a society, based on the principle of maximal entropy, and quantitatively show that it applies to the majority of population.

  17. Aging of safety class 1E transformers in safety systems of nuclear power plants

    SciTech Connect

    Roberts, E.W.; Edson, J.L.; Udy, A.C.

    1996-02-01

    This report discusses aging effects on safety-related power transformers in nuclear power plants. It also evaluates maintenance, testing, and monitoring practices with respect to their effectiveness in detecting and mitigating the effects of aging. The study follows the US Nuclear Regulatory Commission`s (NRC`s) Nuclear Plant-Aging Research approach. It investigates the materials used in transformer construction, identifies stressors and aging mechanisms, presents operating and testing experience with aging effects, analyzes transformer failure events reported in various databases, and evaluates maintenance practices. Databases maintained by the nuclear industry were analyzed to evaluate the effects of aging on the operation of nuclear power plants.

  18. Incidence, age distribution and complications of gonorrhoea in Sweden*

    PubMed Central

    Gisslén, H.; Hellgren, L.; Starck, V.

    1961-01-01

    The incidence of gonorrhoea in Sweden has shown a tendency to increase in recent years, particularly in the age-groups 15-19 and 20-24 years. However, an extrapolation of the annual incidence curve to 1970 for the 15-19-year age-group suggests that some deceleration in that increase may be expected. Study of gonococcal complications seen at Göteborg hospitals during the period 1950-59 indicates that the frequency of gonococcal salpingitis is higher than had previously been reported; this is attributed to the inclusion in the material studied of patients from departments other than those exclusively concerned with the venereal diseases. The authors conclude that, in view of the high frequency of gonorrhoea in the young and of gonococcal complications, gonorrhoea in Sweden cannot be considered an unimportant public health problem. PMID:13705767

  19. Carbon-based phytoplankton size classes retrieved via ocean color estimates of the particle size distribution

    NASA Astrophysics Data System (ADS)

    Kostadinov, Tihomir S.; Milutinović, Svetlana; Marinov, Irina; Cabré, Anna

    2016-04-01

    Owing to their important roles in biogeochemical cycles, phytoplankton functional types (PFTs) have been the aim of an increasing number of ocean color algorithms. Yet, none of the existing methods are based on phytoplankton carbon (C) biomass, which is a fundamental biogeochemical and ecological variable and the "unit of accounting" in Earth system models. We present a novel bio-optical algorithm to retrieve size-partitioned phytoplankton carbon from ocean color satellite data. The algorithm is based on existing methods to estimate particle volume from a power-law particle size distribution (PSD). Volume is converted to carbon concentrations using a compilation of allometric relationships. We quantify absolute and fractional biomass in three PFTs based on size - picophytoplankton (0.5-2 µm in diameter), nanophytoplankton (2-20 µm) and microphytoplankton (20-50 µm). The mean spatial distributions of total phytoplankton C biomass and individual PFTs, derived from global class="text">SeaWiFS monthly ocean color data, are consistent with current understanding of oceanic ecosystems, i.e., oligotrophic regions are characterized by low biomass and dominance of picoplankton, whereas eutrophic regions have high biomass to which nanoplankton and microplankton contribute relatively larger fractions. Global climatological, spatially integrated phytoplankton carbon biomass standing stock estimates using our PSD-based approach yield ˜ 0.25 Gt of C, consistent with analogous estimates from two other ocean color algorithms and several state-of-the-art Earth system models. Satisfactory in situ closure observed between PSD and POC measurements lends support to the theoretical basis of the PSD-based algorithm. Uncertainty budget analyses indicate that absolute carbon concentration uncertainties are driven by the PSD parameter No which determines particle number concentration to first order, while uncertainties in PFTs' fractional contributions to total C biomass

  20. Distribution of microRNA co-targets exhibit universality across a wide class of species

    NASA Astrophysics Data System (ADS)

    Basu, Mahashweta; Bhattacharyya, Nitai P.; Mohanty, P. K.

    2014-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs which regulate gene expression by binding to the 3' UTR of the corresponding messenger RNAs. We construct miRNA co-target networks for a wide class of species (22 in total) using a target prediction database, MicroCosm Targets. For each species, miRNA pairs having one or more common target genes are connected and the number of co-targets are assigned as the weight of these links. We show that the link-weight distributions of all the species collapse remarkably onto each other when scaled suitably —the scale-factor turns out to be a measure of complexity of the species. A simple model, where targets are chosen randomly by miRNAs, could provide the correct scaling function and suggest that the increase of species complexity is related to the increase of the fraction of genes typically targeted by their miRNAs.

  1. 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.

  2. A New Class of Risk-Importance Measures to Support Reactor Aging Management and the Prioritization of Materials Degradation Research

    SciTech Connect

    Unwin, Stephen D.; Lowry, Peter P.; Toyooka, Michael Y.

    2010-06-07

    As the US fleet of light water reactors ages, the risks of operation might be expected to increase. Although probabilistic risk assessment has proven a critical resource in risk-informed regulatory decision-making, limitations in current methods and models have constrained their prospective value in reactor aging management. These limitations stem principally from the use of static component failure rate models (which do not allow the impact of component aging on failure rates to be represented) and a very limited treatment of passive components (which would be expected to have an increasingly significant risk contribution in an aging system). Yet, a PRA captures a substantial knowledge base that could be of significant value in addressing plant aging. In this paper we will describe a methodology and a new class of risk importance measures that allow the use of an existing PRA model to support the management of plant aging, the prioritization of improvements to non-destructive examination and monitoring techniques, and the establishment of research emphases in materials science. This methodology makes use of data resources generated under the USNRC Proactive Management of Materials Degradation program which addresses the anticipated effects of numerous aging degradation mechanisms on a wide variety of component types.

  3. Identity, Age, Proportion of Online Classes, and Success among Students in a Predominantly Online Degree Program

    ERIC Educational Resources Information Center

    Carlsen-Landy, Bev

    2012-01-01

    Most colleges and universities in the US offer at least some classes online, and a significant number of colleges and universities offer degree programs either all online or predominantly online. Many of the distance learning courses and programs emerge from traditional courses and programs; however, in the past decade we have seen the emergence…

  4. Correlation of age with distribution of periodontitis-related bacteria in Japanese dogs.

    PubMed

    Hirai, Norihiko; Shirai, Mitsuyuki; Kato, Yukio; Murakami, Masaru; Nomura, Ryota; Yamasaki, Yoshie; Takahashi, Soraaki; Kondo, Chihiro; Matsumoto-Nakano, Michiyo; Nakano, Kazuhiko; Asai, Fumitoshi

    2013-07-31

    We analyzed the distribution of 11 periodontitis-related bacterial species in dental plaque collected from 176 Japanese dogs divided into young (less than 2 years of age), middle-aged (2-7 years of age) and elderly (more than 8 years of age) groups using a polymerase chain reaction method. Clinical examination revealed that no dogs in the young group were affected by periodontitis, whereas the rates for gingivitis and periodontitis were high in the middle-aged and elderly groups. In addition, the total numbers of bacterial species in the middle-aged and elderly groups were significantly greater than in the young group. Our findings suggest that age is an important factor associated with the distribution of periodontitis-related bacteria and periodontal conditions in dogs.

  5. 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.

  6. Mind the gap: the distributional effects of raising the early eligibility age and full retirement age.

    PubMed

    Olsen, Anya

    2012-01-01

    Policymakers have proposed increases to the early eligibility age (EEA) and/or full retirement age (FRA) to address increasing life expectancy and Social Security solvency issues. This analysis uses the Social Security Administration's Modeling Income in the Near Term, version 6 (MINT6) model to compare three retirement-age increases suggested by the Social Security Advisory Board: increase the gap between the EEA and FRA by raising only the FRA, increase both the EEA and FRA to maintain a 4-year gap between them, and increase both the EEA and FRA to maintain a 5-year gap between them. Although all three options would improve system solvency by similar proportions, their effect on individual beneficiaries in the future would vary. Benefit reductions are greater under the proposals with more months between the EEA and FRA, while the option that maintains a 4-year gap results in benefit increases for some beneficiaries compared with current law. PMID:23397744

  7. Seismic-fragility tests of new and accelerated-aged Class 1E battery cells

    SciTech Connect

    Bonzon, L.L.; Janis, W.J.; Black, D.A.; Paulsen, G.A.

    1987-01-01

    The seismic-fragility response of naturally-aged nuclear station safety-related batteries is of interest for two reasons: (1) to determine actual failure modes and thresholds and (2) to determine the validity of using the electrical capacity of individual cells as an indicator of the potential survivability of a battery given a seismic event. Prior reports in this series discussed the seismic-fragility tests and results for three specific naturally-aged cell types: 12-year old NCX-2250, 10-year old LCU-13, and 10-year old FHC-19. This report focuses on the complementary approach, namely, the seismic-fragility response of accelerated-aged batteries. Of particular interest is the degree to which such approaches accurately reproduce the actual failure modes and thresholds. In these tests the significant aging effects observed, in terms of seismic survivability, were: embrittlement of cell cases, positive bus material and positive plate grids; and excessive sulphation of positive plate active material causing hardening and expansion of positive plates. The IEEE Standard 535 accelerated aging method successfully reproduced seismically significant aging effects in new cells but accelerated grid embrittlement an estimated five years beyond the conditional age of other components.

  8. Distribution and origin of bovine major histocompatibility complex class II DQA1 genes in Japan.

    PubMed

    Takeshima, S; Chen, S; Miki, M; Kado, M; Aida, Y

    2008-09-01

    We sequenced the major histocompatibility complex (MHC) class II DQA1 gene in 352 Japanese cattle (95 Japanese Black, 91 Holstein, 102 Japanese Shorthorn and 64 Jersey cattle) using a new sequence-based typing method. In total, 19 bovine MHC (BoLA)-DQA1 alleles, of which two were novel alleles, were detected. The Holstein, Jersey, Japanese Shorthorn and Japanese Black breeds had 13, 12, 10 and 15 alleles, respectively. The dendrogram that was constructed by the neighbor-joining method on the basis of the DQA1 gene allele frequencies of the four Japanese cattle breeds showed that the Holstein and Japanese Black breeds were closest to each other, with Jersey being farther from these two breeds than Japanese Shorthorn. In addition, Wu-Kabat analysis showed that the DQA1 alleles of the Holstein and Japanese Black were the most and least polymorphic, respectively. Phylogenetic analyses indicated that the DQA1 gene of Bovidae such as cattle, sheep, bison and goat were more similar to pig SLA-DQA genes than to human HLA-DQA1 and dog DLA-DQA genes. The cattle, goat, bison, sheep, human and pig DQA1 molecules had similar rates of amino acid sequence polymorphism, but the distribution of their polymorphic residues differed from that in the dog DQA1 protein. However, the Bovidae DQA1 molecule had more polymorphic residues than the human, pig and dog DQA molecules at two regions, namely positions 52-53 and 65-66. This indicates that the Bovidae DQA1 locus is more polymorphic than the DQA loci of other species.

  9. 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

  10. 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

  11. Major Histocompatibility Complex class I proteins are critical for maintaining neuronal structural complexity in the aging brain.

    PubMed

    Lazarczyk, Maciej J; Kemmler, Julia E; Eyford, Brett A; Short, Jennifer A; Varghese, Merina; Sowa, Allison; Dickstein, Daniel R; Yuk, Frank J; Puri, Rishi; Biron, Kaan E; Leist, Marcel; Jefferies, Wilfred A; Dickstein, Dara L

    2016-01-01

    Major histocompatibility complex class I (MHCI) proteins have been implicated in neuronal function through the modulation of neuritogenesis, synaptogenesis, synaptic plasticity, and memory consolidation during development. However, the involvement of MHCI in the aged brain is unclear. Here we demonstrate that MHCI deficiency results in significant dendritic atrophy along with an increase in thin dendritic spines and a reduction in stubby spines in the hippocampus of aged (12 month old) mice. Ultrastructural analyses revealed a decrease in spine head diameter and post synaptic density (PSD) area, as well as an increase in overall synapse density, and non-perforated, small spines. Interestingly, we found that the changes in synapse density and morphology appear relatively late (after the age of 6 months). Finally, we found a significant age dependent increase in the levels of the glutamate receptor, GluN2B in aged MHCI knockout mice, with no change in GluA2/3, VGluT1, PSD95 or synaptophysin. These results indicate that MHCI may be also be involved in maintaining brain integrity at post-developmental stages notably in the modulation of neuronal and spine morphology and synaptic function during non-pathological aging which could have significant implications for cognitive function. PMID:27229916

  12. Robust Framework to Combine Diverse Classifiers Assigning Distributed Confidence to Individual Classifiers at Class Level

    PubMed Central

    Arshad, Sannia; Rho, Seungmin

    2014-01-01

    We have presented a classification framework that combines multiple heterogeneous classifiers in the presence of class label noise. An extension of m-Mediods based modeling is presented that generates model of various classes whilst identifying and filtering noisy training data. This noise free data is further used to learn model for other classifiers such as GMM and SVM. A weight learning method is then introduced to learn weights on each class for different classifiers to construct an ensemble. For this purpose, we applied genetic algorithm to search for an optimal weight vector on which classifier ensemble is expected to give the best accuracy. The proposed approach is evaluated on variety of real life datasets. It is also compared with existing standard ensemble techniques such as Adaboost, Bagging, and Random Subspace Methods. Experimental results show the superiority of proposed ensemble method as compared to its competitors, especially in the presence of class label noise and imbalance classes. PMID:25295302

  13. Expectation-maximization algorithms for learning a finite mixture of univariate survival time distributions from partially specified class values

    SciTech Connect

    Lee, Youngrok

    2013-05-15

    Heterogeneity exists on a data set when samples from di erent classes are merged into the data set. Finite mixture models can be used to represent a survival time distribution on heterogeneous patient group by the proportions of each class and by the survival time distribution within each class as well. The heterogeneous data set cannot be explicitly decomposed to homogeneous subgroups unless all the samples are precisely labeled by their origin classes; such impossibility of decomposition is a barrier to overcome for estimating nite mixture models. The expectation-maximization (EM) algorithm has been used to obtain maximum likelihood estimates of nite mixture models by soft-decomposition of heterogeneous samples without labels for a subset or the entire set of data. In medical surveillance databases we can find partially labeled data, that is, while not completely unlabeled there is only imprecise information about class values. In this study we propose new EM algorithms that take advantages of using such partial labels, and thus incorporate more information than traditional EM algorithms. We particularly propose four variants of the EM algorithm named EM-OCML, EM-PCML, EM-HCML and EM-CPCML, each of which assumes a specific mechanism of missing class values. We conducted a simulation study on exponential survival trees with five classes and showed that the advantages of incorporating substantial amount of partially labeled data can be highly signi cant. We also showed model selection based on AIC values fairly works to select the best proposed algorithm on each specific data set. A case study on a real-world data set of gastric cancer provided by Surveillance, Epidemiology and End Results (SEER) program showed a superiority of EM-CPCML to not only the other proposed EM algorithms but also conventional supervised, unsupervised and semi-supervised learning algorithms.

  14. EFFECTS OF MIXING AND AGING ON WATER QUALITY IN DISTRIBUTION SYSTEM STORAGE FACILITIES

    EPA Science Inventory

    Aging of water in distribution system storage facilities can lead to deterioration of the water quality due to loss of disinfectant residual and bacterial regrowth. Facilities should be operated to insure that the age of the water is not excessive taking into account the quality...

  15. Long-term frequency aging for unpowered space-class oscillators.

    PubMed

    Bloch, Martin; Ho, John; Mancini, Oleandro; Terracciano, Louis; Mallette, Leo A

    2009-10-01

    Very little data exists regarding the long-term aging performance of space-rated oscillators in the non-operating mode. This paper provides empirical evidence that may be used to estimate the performance of unpowered oscillators for long-term space missions, as well as an aid in validating the worst-case analyses that are routinely performed on these oscillators. The proper operation of any space vehicle is dependent on the performance of the onboard master oscillator. For maximum reliability, the onboard clock is often provided as a dual-or triple-redundant ensemble, with one active oscillator. The backup oscillator(s) are usually powered off and may be off for a significant percentage of the mission. A significant parameter of importance for oscillator performance is the aging rate. Papers have been presented on the aging performance of active oscillators in space, but very little data exists regarding the long-term aging performance of oscillators in the nonoperating mode. The aging rate data are extremely important for predicting the expected performance of these backup oscillators after 10 or 15 years in of non-operation in space. This paper presents performance data derived from temperature controlled crystal oscillators and oven controlled crystal oscillators that have been dormant for decades.

  16. An analysis of the size distribution of Italian firms by age

    NASA Astrophysics Data System (ADS)

    Cirillo, Pasquale

    2010-02-01

    In this paper we analyze the size distribution of Italian firms by age. In other words, we want to establish whether the way that the size of firms is distributed varies as firms become old. As a proxy of size we use capital. In [L.M.B. Cabral, J. Mata, On the evolution of the firm size distribution: Facts and theory, American Economic Review 93 (2003) 1075-1090], the authors study the distribution of Portuguese firms and they find out that, while the size distribution of all firms is fairly stable over time, the distributions of firms by age groups are appreciably different. In particular, as the age of the firms increases, their size distribution on the log scale shifts to the right, the left tails becomes thinner and the right tail thicker, with a clear decrease of the skewness. In this paper, we perform a similar analysis with Italian firms using the CEBI database, also considering firms’ growth rates. Although there are several papers dealing with Italian firms and their size distribution, to our knowledge a similar study concerning size and age has not been performed yet for Italy, especially with such a big panel.

  17. 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...

  18. 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…

  19. Social Orders and Interactions among Children in Age-Mixed Classes in Primary Schools--New Perspectives from a Synthesis of Ethnographic Data

    ERIC Educational Resources Information Center

    Huf, Christina; Raggl, Andrea

    2015-01-01

    The article synthesises data from two ethnographic projects, which both explore interactions of children in age-mixed groups in primary schools. It illuminates critical perspectives on social orders and children's interactions in age-mixed classes by showing how pupils in age-mixed groups become involved in power relations and how the teacher's…

  20. Cephalometric effects of face mask/expansion therapy in Class III children: a comparison of three age groups.

    PubMed

    Kapust, A J; Sinclair, P M; Turley, P K

    1998-02-01

    The purpose of this investigation was to determine the skeletal, dental, and soft tissue effects of face mask/expansion therapy and to examine the effect of age on treatment response. Pretreatment and posttreatment cephalometric radiographs from 63 subjects (4 to 13 years) who had a Class III malocclusion were analyzed. Serial cephalometric tracings of 32 subjects with Class I occlusion made at 4, 6, 8, 10, 12, and 14 years were used as controls. Landmarks were digitized on each tracing and treatment effects were measured by using cranial base and maxillary superimposition techniques. Annual rate differences were compared with t tests for the combined treated group (N = 63) and between stratified treated groups (4 to 7 years N = 15, 7 to 10 years N = 32, 10 to 14 years N = 16). The treated group (N = 63) demonstrated significant (p < 0.001) hard and soft tissue changes that resulted from treatment. Skeletal change was primarily a result of anterior and vertical movement of the maxillae. Mandibular position was directed in a downward and backward vector. Orthodontic changes contributed to the correction, and soft tissue effects resulted in a more convex profile. Minimal significant differences were observed between age groups when comparing angular and linear measurements alone. However, when analyzing the algebraic sum of treatment effects (Johnston analysis), significantly (p < 0.01) greater differences were observed in apical base change (ABCH) and total molar correction (6/6) in the younger age groups. This study demonstrates that face mask/expansion therapy produces dentofacial changes that combine to improve the Class III malocclusion. Although early treatment may be most effective, face mask therapy can provide a viable option for older children as well.

  1. 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.

  2. [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.

  3. Pitch-class distribution modulates the statistical learning of atonal chord sequences.

    PubMed

    Daikoku, Tatsuya; Yatomi, Yutaka; Yumoto, Masato

    2016-10-01

    The present study investigated whether neural responses could demonstrate the statistical learning of chord sequences and how the perception underlying a pitch class can affect the statistical learning of chord sequences. Neuromagnetic responses to two chord sequences of augmented triads that were presented every 0.5s were recorded from fourteen right-handed participants. One sequence was a series of 360 chord triplets, each of which consisted of three chords in the same pitch class (clustered pitch-classes sequences). The other sequence was a series of 360 chord triplets, each of which consisted of three chords in different pitch classes (dispersed pitch-classes sequences). The order of the triplets was constrained by a first-order Markov stochastic model such that a forthcoming triplet was statistically defined by the most recent triplet (80% for one; 20% for the other two). We performed a repeated-measures ANOVA with the peak amplitude and latency of the P1m, N1m and P2m. In the clustered pitch-classes sequences, the P1m responses to the triplets that appeared with higher transitional probability were significantly reduced compared with those with lower transitional probability, whereas no significant result was detected in the dispersed pitch-classes sequences. Neuromagnetic significance was concordant with the results of familiarity interviews conducted after each learning session. The P1m response is a useful index for the statistical learning of chord sequences. Domain-specific perception based on the pitch class may facilitate the domain-general statistical learning of chord sequences. PMID:27429093

  4. Wide tissue distribution of axolotl class II molecules occurs independently of thyroxin.

    PubMed

    Völk, H; Charlemagne, J; Tournefier, A; Ferrone, S; Jost, R; Parisot, R; Kaufman, J

    1998-04-01

    Unlike most salamanders, the Mexican axolotl (Ambystoma mexicanum) fails to produce enough thyroxin to undergo anatomical metamorphosis, although a "cryptic metamorphosis" involving a change from fetal to adult hemoglobins has been described. To understand to what extent the development of the axolotl hemopoietic system is linked to anatomical metamorphosis, we examined the appearance and thyroxin dependence of class II molecules on thymus, blood, and spleen cells, using both flow cytometry and biosynthetic labeling followed by immunoprecipitation. Class II molecules are present on B cells as early as 7 weeks after hatching, the first time analyzed. At this time, most thymocytes, all T cells, and all erythrocytes lack class II molecules, but first thymocytes at 17 weeks, then T cells at 22 weeks, and finally erythrocytes at 26-27 weeks virtually all bear class II molecules. Class II molecules and adult hemoglobin appear at roughly the same time in erythrocytes. These data are most easily explained by populations of class II-negative cells being replaced by populations of class II-positive cells, and they show that the hemopoietic system matures at a variety of times unrelated to the increase of thyroxin that drives anatomical metamorphosis. We found that administration of thyroxin during axolotl ontogeny does not accelerate or otherwise affect the acquisition of class II molecules, nor does administration of drugs that inhibit thyroxin (sodium perchlorate, thiourea, methimazole, and 1-methyl imidazole) retard or abolish this acquisition, suggesting that the programs for anatomical metamorphosis and some aspects of hemopoietic development are entirely separate. PMID:9510551

  5. 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.

  6. 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.

  7. Stratified at Seven: In-Class Ability Grouping and the Relative Age Effect

    ERIC Educational Resources Information Center

    Campbell, Tammy

    2014-01-01

    There is an established body of evidence indicating that a pupil's relative age within their school year cohort is associated with academic attainment throughout compulsory education. In England, autumn-born pupils consistently attain at higher levels than summer-born pupils. Analysis here investigates a possible channel of this relative age…

  8. First in the Class? Age and the Education Production Function. NBER Working Paper No. 13663

    ERIC Educational Resources Information Center

    Cascio, Elizabeth; Schanzenbach, Diane Whitmore

    2007-01-01

    Older children outperform younger children in a school-entry cohort well into their school careers. The existing literature has provided little insight into the causes of this phenomenon, leaving open the possibility that school-entry age is zero-sum game, where relatively young students lose what relatively old students gain. In this paper, we…

  9. Middle-Aged Working Class Americans at Home. Changing Expectations of Manhood

    ERIC Educational Resources Information Center

    Shostak, Arthur B.

    1972-01-01

    Describes the changing role expectations of the middle-aged blue-collar male as a husband, lover, father, and son, from a formerly stereotyped Archie Bunker" type of role model to one that is aware of improved performance needed in these family roles. (AG)

  10. Distribution and determinants of functioning and disability in aged adults - results from the German KORA-Age study

    PubMed Central

    2013-01-01

    Background Today industrialized countries face a burgeoning aged population. Thus, there is increasing attention on the functioning and disabilities of aged adults as potential determinants of autonomy and independent living. However, there are few representative findings on the prevalence and determinants of disability in aged persons in the German population. The objective of our study is to examine the frequency, distribution and determinants of functioning and disability in aged persons and to assess the contribution of diseases to the prevalence of disability. Methods Data originate from the MONICA/KORA study, a population-based epidemiological cohort. Survivors of the original cohorts who were 65 and older were examined by telephone interview in 2009. Disability was assessed with the Health Assessment Questionnaire Disability Index (HAQ-DI). Minimal disability was defined as HAQ-DI > 0. Logistic regression was used to adjust for potential confounders and additive regression to estimate the contribution of diseases to disability prevalence. Results We analyzed a total of 4117 persons (51.2% female) with a mean age of 73.6 years (SD = 6.1). Minimal disability was present in 44.7% of all participants. Adjusted for age and diseases, disability was positively associated with female sex, BMI, low income, marital status, physical inactivity and poor nutritional status, but not with smoking and education. Problems with joint functions and eye diseases contributed most to disability prevalence in all age groups. Conclusions In conclusion, this study could show that there are vulnerable subgroups of aged adults who should receive increased attention, specifically women, those with low income, those over 80, and persons with joint or eye diseases. Physical activity, obesity and malnutrition were identified as modifiable factors for future targeted interventions. PMID:23410010

  11. CLASS plans for providing archive, access, and distribution services for GOES-R data

    NASA Astrophysics Data System (ADS)

    Rank, Robert; Kidd, Alexander; Cremidis, Constantino

    2006-08-01

    The Comprehensive Large Array-data Stewardship System (CLASS), a National Oceanic and Atmospheric Administration (NOAA) IT enterprise solution supporting NOAA's data archive and science data stewardship missions by providing the IT portion of an archive for environmental data. CLASS requirements are defined by NOAA's Archive Requirements Working Group (ARWG), which serves as a clearinghouse for requirement planning and ensures that science and other user requirements are clearly defined with respect to NOAA's archive. Currently, CLASS is part of a major 10-year growth program to add new data sets and functionality to support a broader user base. NOAA needs to define the types of data to be archived, metadata managing standards, and the data search, display, and delivery services that CLASS will provide to users. These requirements are captured in documents that include MOAs, ICDs and OAIS-compliant Data Submission Agreements that drive the software and hardware architecture changes needed to handle the expected future increases in user and data volumes. The paper will present CLASS' approach for other major data campaigns such as Metop, NPP, NPOESS and EOS, historical data and its plans for going forward with the GOES-R data campaign.

  12. Inhibitory Control Efficiency in a Piaget-Like Class-Inclusion Task in School-Age Children and Adults: A Developmental Negative Priming Study

    ERIC Educational Resources Information Center

    Borst, G.; Poirel, N.; Pineau, A.; Cassotti, M.; Houdé, O.

    2013-01-01

    Most children under 7 years of age presented with 10 daisies and 2 roses fail to indicate that there are more flowers than daisies. Instead of the appropriate comparison of the relative numerosities of the superordinate class (flowers) to its subordinate class (daisies), they perform a direct perceptual comparison of the extensions of the 2…

  13. Evaluation of efficacies of different classes of antidepressants in the forced swimming test in mice at different ages.

    PubMed

    Bourin, M; Colombel, M C; Redrobe, J P; Nizard, J; Hascoët, M; Baker, G B

    1998-02-01

    1. The efficacies of different classes of antidepressants were investigated using the forced swimming test with mice at different ages. 2. Imipramine (4-32 mg/kg), desipramine (2-16 mg/kg) and bupropion (32, 64 mg/kg) showed activity in all age groups. 3. The selective serotonin reuptake inhibitors (SSRIs) citalopram (16 and 32 mg) and paroxetine (4 and 8 mg) were inactive in the oldest (40 weeks) group of mice, despite showing activity at the same doses in mice ranging in age from 4-24 weeks old. 4. Both SSRIs showed anti-immobility effects at low doses, (paroxetine: 1 and 2 mg/kg; citalopram: 4 and 8 mg/kg) in the 40-week old mice. These effects were not evident in the three younger groups of mice. 5. Moclobemide, a reversible selective inhibitor of monoamine oxidase-A, showed activity only at a high dose (128 mg/kg) and only in 12-week old animals. 6. Since SSRIs have been reported to have relatively selective effects on 5-HT1B receptors, the present results suggest that further studies comparing the effectiveness of SSRIs and other antidepressants in elderly patients should be done. Studies of the effects of aging on the density and/or affinity of 5-HT1A and 5-HT1B/1D receptors are also warranted.

  14. A Program for Partitioning Shifted Truncated Lognormal Distributions into Size-Class Bins

    USGS Publications Warehouse

    Attanasi, E.D.; Charpentier, Ronald R.

    2007-01-01

    In recent years, oil and gas accumulation-size frequency distributions have become a standard way to characterize undiscovered conventional oil and gas resources that have been postulated by geologic assessments. The preparation of such distributions requires the assessment geologists to explicitly choose parameters for the probability distribution for the sizes of undiscovered accumulations. The purpose of this report is to present a computational scheme for obtaining a binned size frequency distribution of undiscovered accumulations when the undiscovered accumulation size distribution is shifted truncated lognormal.

  15. 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.

  16. Revisiting the thermal and superthermal two-class distribution of incomes. A critical perspective

    NASA Astrophysics Data System (ADS)

    Schneider, Markus P. A.

    2015-01-01

    This paper offers a two-pronged critique of the empirical investigation of the income distribution performed by physicists over the past decade. Their finding rely on the graphical analysis of the observed distribution of normalized incomes. Two central observations lead to the conclusion that the majority of incomes are exponentially distributed, but neither each individual piece of evidence nor their concurrent observation robustly proves that the thermal and superthermal mixture fits the observed distribution of incomes better than reasonable alternatives. A formal analysis using popular measures of fit shows that while an exponential distribution with a power-law tail provides a better fit of the IRS income data than the log-normal distribution (often assumed by economists), the thermal and superthermal mixture's fit can be improved upon further by adding a log-normal component. The economic implications of the thermal and superthermal distribution of incomes, and the expanded mixture are explored in the paper.

  17. LIPID CLASS DISTRIBUTION OF HIGHLY UNSATURATED LONG CHAIN FATTY ACIDS IN MARINE DINOFLAGELLATES.

    EPA Science Inventory

    The very long chain highly unsaturated C28 fatty acids, octacosaheptaenoic [28:7(n-6)] and octacosaoctaenoic acid [28:8(n-3)], were found to be associated with phospholipids, obtained by fractionation of total lipid extracts into distinct lipid classes, in 4 and 6, respectively, ...

  18. On the Asymptotic Distributions of Two Statistics for Two-Level Covariance Structure Models within the Class of Elliptical Distributions

    ERIC Educational Resources Information Center

    Yuan, Ke-Hai; Bentler, Peter M.

    2004-01-01

    Since data in social and behavioral sciences are often hierarchically organized, special statistical procedures for covariance structure models have been developed to reflect such hierarchical structures. Most of these developments are based on a multivariate normality distribution assumption, which may not be realistic for practical data. It is…

  19. Paleomagnetic Age for the World-class Century Zn-Pb-Ag Deposit, Australia

    NASA Astrophysics Data System (ADS)

    Kawasaki, K.; Symons, D. T.; Dawborn, T.

    2009-05-01

    Paleomagnetic results are reported for the Century Zn-Pb-Ag SEDEX deposit in northwestern Queensland, Australia. The stratiform mineralization occurs in fine parallel lamellae in ˜1595 Ma siderite-rich siltstones and black shales of the upper Lawn Hill Formation in the Proterozoic McNamara Group. Galena from the deposit has given a Pb/Pb model age of ˜1575 Ma. Paleomagnetic analysis of 333 specimens from ore zones (15 sites), and hanging wall (4 sites) and footwall (5 sites) siltstones using mostly thermal and then alternating field step demagnetization, isolates a stable characteristic remanent magnetization (ChRM) for the ore sites only. Step demagnetization, rock magnetic tests and thermomagnetic analyses of ore, Zn and Pb concentrates and tailings show that the main remanence carriers are single- or pseudosingle-domain inclusions of titanomagnetite in sphalerite and gangue, and pyrrhotite in galena with modern goethite and/or hematite from the weathering of siderite. A paleomagnetic fold test using the ore sites is positive, showing that the ore ChRM predates D2 deformation in the ˜1595 to ˜1500 Ma Isan orogeny. The orogeny folded the main-stage mineralization, indicating that the ore retains a primary magnetization. The optimum 80% tilt-corrected unit mean ChRM direction for the ore gives a Mesoproterozoic paleopole at ˜1560 Ma on the northern Australian apparent polar wander path. Thus this result both constrains the timing of mineralization and provides an upper age limit for D2 deformation in the orogeny.

  20. A simple class of singular, two species Vlasov equilibria sustaining nonmonotonic potential distributions

    SciTech Connect

    Nocera, L.; Palumbo, L. J.

    2013-01-15

    We present new elementary, exact weak singular solutions of the steady state, two species, electrostatic, one dimensional Vlasov-Poisson equations. The distribution of the hot, finite mass, mobile ions is assumed to be log singular at the position of the electric potential's minimum. We show that the electron energy distributions on opposite sides of this minimum are not equal. This leads to a jump discontinuity of the electron distribution across its separatrix. A simple relation exists between the difference of these two electron distributions and that of the ions. The velocity Fourier transform of the electron singular distribution is smooth and appears as a simple Neumann series. Elementary, finite amplitude profiles of the electric potential result from Poisson equation, which are smoothly, but nonmonotonically and asymmetrically distributed in space. Two such profiles are given explicitly as appropriate for a nonmonotonic double layer and for a plasma bounded by a surface. The distributions of both electrons and ions supporting such potential meet smooth and kinetically stable boundary conditions at one plasma boundary. For sufficiently small potential to electron temperature ratios, the nonthermal, discontinuous electron distribution resulting at the other plasma boundary is also stable against Landau damped perturbations of the electron distribution.

  1. Multiple plumage traits convey information about age and within-age-class qualities of a canopy-dwelling songbird, the Cerulean Warbler

    USGS Publications Warehouse

    Boves, Than J.; Buehler, David A.; Wood, Petra Bohall; Rodewald, Amanda D.; Larkin, Jeffrey L.; Keyser, Patrick D.; Wigley, T. Ben

    2014-01-01

    Colorful plumage traits in birds may convey multiple, redundant, or unreliable messages about an individual. Plumage may reliably convey information about disparate qualities such as age, condition, and parental ability because discrete tracts of feathers may cause individuals to incur different intrinsic or extrinsic costs. Few studies have examined the information content of plumage in a species that inhabits forest canopies, a habitat with unique light environments and selective pressures. We investigated the information content of four plumage patches (blue-green crown and rump, tail white, and black breast band) in a canopy-dwelling species, the Cerulean Warbler (Setophaga cerulea), in relation to age, condition, provisioning, and reproduction. We found that older males displayed wider breast bands, greater tail white, and crown and rump feathers with greater blue-green (435–534 nm) chroma and hue than males in their first potential breeding season. In turn, older birds were in better condition (short and long term) and were reproductively superior to younger birds. We propose that these age-related plumage differences (i.e. delayed plumage maturation) were not a consequence of a life history strategy but instead resulted from constraints during early feather molts. Within age classes, we found evidence to support the multiple messages hypothesis. Birds with greater tail white molted tails in faster, those with more exaggerated rump plumage (lower hue, greater blue-green chroma) provisioned more, and those with lower rump blue-green chroma were in better condition. Despite evidence of reliable signaling in this species, we found no strong relationships between plumage and reproductive performance, potentially because factors other than individual differences more strongly influenced fecundity.

  2. Necessity of Periodic Ophthalmological Examinations in Binocular B Class Driving Licence Holders Over 50 Years of Age

    PubMed Central

    Kurt, Ali; Öktem, Çağlar; Karabıçak Acer, Ayşe; Kocamış, Özkan; Taşdemir, Sedat

    2016-01-01

    Objective: To determine whether binocular B class driving licence (BBCDL) holders over 50 years old are in compliance with the BBCDL criteria for visual acuity, to determine the age-based prevalence of ophthalmological disorders reducing visual acuity in this group, and to investigate whether periodic ophthalmological examinations are needed in licence holders over 50 years of age. Materials and Methods: This prospective study enrolled 451 adults over 50 years old having a BBCDL. The study subjects were categorized into 3 age groups as group 1 (51-60 years), group 2 (61-70 years), and group 3 (over 71 years). Results: The mean age of the subjects was 60.02±7.27 years; 338 (74.9%) were male and 113 (25.1%) were female. The BBCDL criteria were met by 353 (78.3%) subjects whereas 98 (21.7%) subjects did not meet them. Eighty-four (85.7%) of 98 patients not meeting BBCDL criteria still drove. The mean age of the subjects meeting BBCDL criteria (58.82±6.77 years) was significantly lower than the subjects not meeting them (64.34±7.40 years) (p<0.001). The most common pathologies in the individuals still driving despite not meeting BBCDL criteria were senile cataract (38.5%) and diabetic retinopathy (23.1%) in group 1, senile cataract (55.3%) and diabetic retinopathy (14.9%) in group 2, and senile cataract (63.6%) and senile macular degeneration+senile cataract (18.2%) in group 3. Conclusion: More than a fifth of individuals over 50 years old did not meet the BBCDL criteria, due predominantly to senile cataract, and the majority of these individuals continue to drive. Therefore, we believe that individuals over 50 years old who have a BBCDL should undergo periodic ophthalmological examinations.

  3. Harnessing heredity in Gilded Age America: middle class mores and industrial breeding in a cultural context.

    PubMed

    Thurtle, Phillip

    2002-01-01

    By investigating the practices and beliefs of Gilded Age trotting horse breeders, this article demonstrates the relationship between industrial economic development and the growth of genetic reasoning in the United States. As most historians of biology already know, E. H. Harriman, Leland Stanford, and John D. Rockefeller not only transformed American business practice, they donated heavily to institutions that promoted eugenic research programs. What is not widely known, however, is that these same industrialists were accomplished trotting horse breeders with well-developed theories of inheritance. The article that follows uses these theories to place the rise of eugenic and genetic research into the context of the rapid development of industry in post Civil War America. Specifically, the study identifies how functional utility as defined through the narrow concerns of industrial practices were privileged over form and pedigree in American horse breeding. Even more importantly, this article suggests that the continuity established between the practices of the industrial philanthropists and the scientific research institutions that they established occurred at two levels: through the values privileged by the development of the dynamics of a mass society and through the tools used to process the large amounts of information necessary to understand breeding patterns in slow breeding organisms. PMID:12068894

  4. In silico Identification and Taxonomic Distribution of Plant Class C GH9 Endoglucanases

    PubMed Central

    Kundu, Siddhartha; Sharma, Rita

    2016-01-01

    The glycoside hydrolase 9 superfamily, mainly comprising the endoglucanases, is represented in all three domains of life. The current division of GH9 enzymes, into three subclasses, namely A, B, and C, is centered on parameters derived from sequence information alone. However, this classification is ambiguous, and is limited by the paralogous ancestry of classes B and C endoglucanases, and paucity of biochemical and structural data. Here, we extend this classification schema to putative GH9 endoglucanases present in green plants, with an emphasis on identifying novel members of the class C subset. These enzymes cleave the β(1 → 4) linkage between non-terminal adjacent D-glucopyranose residues, in both, amorphous and crystalline regions of cellulose. We utilized non redundant plant GH9 enzymes with characterized molecular data, as the training set to construct Hidden Markov Models (HMMs) and train an Artificial Neural Network (ANN). The parameters that were used for predicting dominant enzyme function, were derived from this training set, and subsequently refined on 147 sequences with available expression data. Our knowledge-based approach, can ascribe differential endoglucanase activity (A, B, or C) to a query sequence with high confidence, and was used to construct a local repository of class C GH9 endoglucanases (GH9C = 241) from 32 sequenced green plants. PMID:27570528

  5. In silico Identification and Taxonomic Distribution of Plant Class C GH9 Endoglucanases.

    PubMed

    Kundu, Siddhartha; Sharma, Rita

    2016-01-01

    The glycoside hydrolase 9 superfamily, mainly comprising the endoglucanases, is represented in all three domains of life. The current division of GH9 enzymes, into three subclasses, namely A, B, and C, is centered on parameters derived from sequence information alone. However, this classification is ambiguous, and is limited by the paralogous ancestry of classes B and C endoglucanases, and paucity of biochemical and structural data. Here, we extend this classification schema to putative GH9 endoglucanases present in green plants, with an emphasis on identifying novel members of the class C subset. These enzymes cleave the β(1 → 4) linkage between non-terminal adjacent D-glucopyranose residues, in both, amorphous and crystalline regions of cellulose. We utilized non redundant plant GH9 enzymes with characterized molecular data, as the training set to construct Hidden Markov Models (HMMs) and train an Artificial Neural Network (ANN). The parameters that were used for predicting dominant enzyme function, were derived from this training set, and subsequently refined on 147 sequences with available expression data. Our knowledge-based approach, can ascribe differential endoglucanase activity (A, B, or C) to a query sequence with high confidence, and was used to construct a local repository of class C GH9 endoglucanases (GH9C = 241) from 32 sequenced green plants. PMID:27570528

  6. The histories of ordinary chondrite parent bodies - U, Th-He age distributions

    SciTech Connect

    Wasson, J.T.; Wang, Sichao Purple Mountain Observatory, Nanjing )

    1991-06-01

    Age patterns observed in meteorite groups reflect the different thermal or impact histories experienced by their parent bodies. To assess the number of ordinary chondrite (OC) parent bodies, rare-gas data in the Schultz and Kruse (1989) data base were used to calculate U, Th-He gas-retention ages. Most H- and LL-chondrite ages are high; about 81 percent are greater than 2.2 Ga. In contrast, most L-chondrite ages are low; about 69 percent are not greater than 2.2 Ga, and about 35 percent are not greater than 0.9 Ga. The latter fraction is substantially lower than the value of 44 percent given by Heymann (1967). The difference is attributed to the preferential inclusion of shocked L chondrites in early studies. Broad age peaks in the H and LL groups near 3.4 Ga probably reflect thermal loss during metamorphism, but in the H distribution there is a hint of minor outgassing 'events' near 1 Ga. The L/LL chondrites have chemical properties intermediate between and unresolvable from L and LL chondrites. The high ages of most L/LL chondrites are evidence against these originating on the L parent body; the L/LL age distribution is consistent with an origin on the LL parent body or on an independent body. 22 refs.

  7. The histories of ordinary chondrite parent bodies - U, Th-He age distributions

    NASA Astrophysics Data System (ADS)

    Wasson, John T.; Wang, Sichao

    1991-06-01

    Age patterns observed in meteorite groups reflect the different thermal or impact histories experienced by their parent bodies. To assess the number of ordinary chondrite (OC) parent bodies, rare-gas data in the Schultz and Kruse (1989) data base were used to calculate U, Th-He gas-retention ages. Most H- and LL-chondrite ages are high; about 81 percent are greater than 2.2 Ga. In contrast, most L-chondrite ages are low; about 69 percent are not greater than 2.2 Ga, and about 35 percent are not greater than 0.9 Ga. The latter fraction is substantially lower than the value of 44 percent given by Heymann (1967). The difference is attributed to the preferential inclusion of shocked L chondrites in early studies. Broad age peaks in the H and LL groups near 3.4 Ga probably reflect thermal loss during metamorphism, but in the H distribution there is a hint of minor outgassing "events" near 1 Ga. The L/LL chondrites have chemical properties intermediate between and unresolvable from L and LL chondrites. The high ages of most L/LL chondrites are evidence against these originating on the L parent body; the L/LL age distribution is consistent with an origin on the LL parent body or on an independent body.

  8. 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.

  9. Apparent inferiority of first-time breeders in the kittiwake: The role of heterogeneity among age classes

    USGS Publications Warehouse

    Cam, E.; Monnat, J.-Y.

    2000-01-01

    1. Many studies have provided evidence that first-time breeders have a lower survival, a lower probability of success, or of breeding, in the following year. Hypotheses based on reproductive costs have often been proposed to explain this. However, because of the intrinsic relationship between age and experience, the apparent inferiority of first-time breeders at the population level may result from selection, and experience may not influence performance within each individual. In this paper we address the question of phenotypic correlations between fitness components. This addresses differences in individual quality, a prerequisite for a selection process to occur. We also test the hypothesis of an influence of experience on these components while taking age and reproductive success into account: two factors likely to play a key role in a selection process. 2. Using data from a long-term study on the kittiwake, we found that first-time breeders have a lower probability of success, a lower survival and a lower probability of breeding in the next year than experienced breeders. However, neither experienced nor inexperienced breeders have a lower survival or a lower probability of breeding in the following year than birds that skipped a breeding opportunity. This suggests heterogeneity in quality among individuals. 3. Failed birds have a lower survival and a lower probability of breeding in the following year regardless of experience. This can be interpreted in the light of the selection hypothesis. The inferiority of inexperienced breeders may be linked to a higher proportion of lower-quality individuals in younger age classes. When age and breeding success are controlled for, there is no evidence of an influence of experience on survival or future breeding probability. 4. Using data from individuals whose reproductive life lasted the same number of years, we investigated the influence of experience on reproductive performance within individuals. There is no strong

  10. Transient water age distributions in environmental flow systems: The time-marching Laplace transform solution technique

    NASA Astrophysics Data System (ADS)

    Cornaton, F. J.

    2012-03-01

    Environmental fluid circulations are very often characterized by analyzing the fate and behavior of natural and anthropogenic tracers. Among these tracers, age is taken as an ideal tracer which can yield interesting diagnoses, as for example the characterization of the mixing and renewal of water masses, of the fate and mixing of contaminants, or the calibration of hydrodispersive parameters used by numerical models. Such diagnoses are of great interest in atmospheric and ocean circulation sciences, as well in surface and subsurface hydrology. The temporal evolution of groundwater age and its frequency distributions can display important changes as flow regimes vary due to natural change in climate and hydrologic conditions and/or human induced pressures on the resource to satisfy the water demand. Groundwater age being nowadays frequently used to investigate reservoir properties and recharge conditions, special attention needs to be put on the way this property is characterized, would it be using isotopic methods or mathematical modeling. Steady state age frequency distributions can be modeled using standard numerical techniques since the general balance equation describing age transport under steady state flow conditions is exactly equivalent to a standard advection-dispersion equation. The time-dependent problem is however described by an extended transport operator that incorporates an additional coordinate for water age. The consequence is that numerical solutions can hardly be achieved, especially for real 3-D applications over large time periods of interest. A novel algorithm for solving the age distribution problem under time-varying flow regimes is presented and, for some specific configurations, extended to the problem of generalized component exposure time. The algorithm combines the Laplace transform technique applied to the age (or exposure time) coordinate with standard time-marching schemes. The method is validated and illustrated using analytical

  11. 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

  12. A New Framework for Analysis on Stability and Bifurcation in a Class of Neural Networks With Discrete and Distributed Delays.

    PubMed

    Xu, Wenying; Cao, Jinde; Xiao, Min; Ho, Daniel W C; Wen, Guanghui

    2015-10-01

    This paper studies the stability and Hopf bifurcation in a class of high-dimension neural network involving the discrete and distributed delays under a new framework. By introducing some virtual neurons to the original system, the impact of distributed delay can be described in a simplified way via an equivalent new model. This paper extends the existing works on neural networks to high-dimension cases, which is much closer to complex and real neural networks. Here, we first analyze the Hopf bifurcation in this special class of high dimensional model with weak delay kernel from two aspects: one is induced by the time delay, the other is induced by a rate parameter, to reveal the roles of discrete and distributed delays on stability and bifurcation. Sufficient conditions for keeping the original system to be stable, and undergoing the Hopf bifurcation are obtained. Besides, this new framework can also apply to deal with the case of the strong delay kernel and corresponding analysis for different dynamical behaviors is provided. Finally, the simulation results are presented to justify the validity of our theoretical analysis.

  13. Impact of Hydrologic Variability on Nutrient Age Distribution in Intensively Managed Landscapes

    NASA Astrophysics Data System (ADS)

    Kumar, P.; Woo, D. K.

    2014-12-01

    The distribution, concentration, and transport of nutrients in agricultural landscapes are of significant societal concern. Our interests in reactive nitrogen and the nitrogen cycle have shifted from increasing the efficiency of nitrogen delivery to target crop species to decreasing environmental damage caused by intensive agricultural practices. Enhancing the reactive nitrogen use efficiency to increase food production to meet future demand inevitably contributes to an increase in the reactive nitrogen load in the ecosystem, and damaging the environment. However, due to the complexity of the nitrogen cycle, the dynamics of nitrogen in soils and its interactions with ecohydrological processes at the watershed and regional scales are not well understood to enable adequate remedial measures. To unravel the complexity of this dynamics we have developed a model for characterizing the nitrogen age (elapsed time) distribution. The goal of our study is to develop and analyze the dynamics of nitrogen in the context of age and transit times resulting from advection, mixing, and production/destruction processes; evaluate the effects of micro-topographic variability on the nitrogen age distributions; and investigate how the temporal dynamics of the nitrogen age distribution are affected by changes in the variability of climate drivers. Our study is performed for the Upper Sangamon River Basin in the Critical Zone Observatory for Intensively Managed Landscapes (IML-CZO).

  14. 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...

  15. 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.

  16. Recent Changes in the U.S. Age at Death Distribution: Further Observations.

    ERIC Educational Resources Information Center

    Myers, George C.; Manton, Kenneth G.

    1984-01-01

    Responds to discussion (Fries, 1984) of an earlier article (Myers and Manton, 1984) presenting empirical evidence on changes in the distribution of ages at death. Further analysis of the data is presented, including life expectancy changes from 1950-1978 and comparison of data for men and women from several countries. (JAC)

  17. Age distribution curve in psychiatric admissions inversely correlates with Life Satisfaction.

    PubMed

    Le Bon, Olivier; Le Bon, Serge-Daniel

    2014-09-30

    A strong inverse correlation was found between the age-distribution curve of psychiatric admissions and the U-bend Life Satisfaction curve. It may indicate that the peak of mental disorders at midlife reflects a less satisfactory period of life or, conversely, that the mental health load burdens of Life Satisfaction.

  18. 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

  19. Constraining age distributions of groundwater from public supply wells in diverse hydrogeological settings in Scania, Sweden

    NASA Astrophysics Data System (ADS)

    Åkesson, Maria; Suckow, Axel; Visser, Ate; Sültenfuβ, Jürgen; Laier, Troels; Purtschert, Roland; Sparrenbom, Charlotte J.

    2015-09-01

    Twenty-five public supply wells throughout the hydrogeologically diverse region of Scania, southern Sweden are subjected to environmental tracer analysis (3H-3He, 4He, CFCs, SF6 and for one well only also 85Kr and 39Ar) to study well and aquifer vulnerability and evaluate possibilities of groundwater age distribution assessment. We find CFC and SF6 concentrations well above solubility equilibrium with modern atmosphere, indicating local contamination, as well as indications of CFC degradation. The tracer-specific complications considerably constrain possibilities for sound quantitative regional groundwater age distribution assessments and demonstrate the importance of initial qualitative assessment of tracer-specific reliability, as well a need for additional, complementary tracers (e.g. 85Kr, 39Ar and potentially also 14C). Lumped parameter modelling yields credible age distribution assessments for representative wells in four type aquifers. Pollution vulnerability of the aquifer types was based on the selected LPM models and qualitative age characterisation. Most vulnerable are unconfined dual porosity and fractured bedrock aquifers, due to a large component of very young groundwater. Unconfined sedimentary aquifers are vulnerable due to young groundwater and a small pre-modern component. Less vulnerable are semi-confined sedimentary or dual-porosity aquifers, due to older age of the modern component and a larger pre-modern component. Confined aquifers appear least vulnerable, due an entirely pre-modern groundwater age distribution (recharged before 1963). Tracer complications aside, environmental tracer analyses and lumped parameter modelling aid in vulnerability assessment and protection of regional groundwater resources.

  20. Prevalence of dominant mutations in Spain: effect of changes in maternal age distribution.

    PubMed

    Martínez-Frías, M L; Herranz, I; Salvador, J; Prieto, L; Ramos-Arroyo, M A; Rodríguez-Pinilla, E; Cordero, J F

    1988-12-01

    We studied the birth prevalence of autosomal dominant mutations in Spain and estimated how a decrease in maternal age distribution may lead to reduction in dominant mutations. The data were collected by the Estudio Colaborativo Español de Malformaciones Congénitas from April, 1976, to December, 1985. Among 553,270 liveborn infants monitored during the period, 66 infants with autosomal dominant conditions were identified. These included Apert, Crouzon, Hay-Wells, Treacher-Collins, Robinow, Stickler, Adams-Oliver, and the blepharophimosis syndromes, achondroplasia, cleidocranial dysostosis, and thanatophoric dysplasia. The overall rate of autosomal dominant conditions was 1.2 per 10,000 liveborn infants. Thirteen (20%) had an affected relative, and 52 (79%) had a negative family history. One case was excluded because of insufficient family data. The rate of autosomal dominant mutations was 0.9 per 10,000 liveborn infants, or 47 per 1 million gametes. A reduction in the maternal age distribution of mothers age 35 years and older from the current 10.8% to 4.9%, as in Atlanta, Georgia, would reduce the rate of Down syndrome in Spain by 33% and through a change in parternal age distribution may lead to a reduction in dominant mutations of about 9.6%. This suggests that a public health campaign to reduce older maternal age distribution in Spain may also lead to a reduction in dominant mutations and emphasizes the potential that a direct campaign for fathers to complete their families before age 35 years may have a small, but measurable, effect in the primary prevention of dominant mutations.

  1. Divergent patterns of abundance and age-class structure of headwater stream tadpoles in burned and unburned watersheds

    USGS Publications Warehouse

    Hossack, B.R.; Corn, P.S.; Fagre, D.B.

    2006-01-01

    Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphus montanus Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams in northwestern Montana to determine the effects of wildfire on A. montanus. All streams were initially sampled in 2001, 2 years before four of them burned in a large wildfire, and were resampled during the 2 years following the fire. Counts of tadpoles were similar in the two groups of streams before the fire. After the fire, tadpoles were almost twice as abundant in unburned streams than in burned streams. The fire seemed to have the greatest negative effect on abundance of age-1 tadpoles, which was reflected in the greater variation in same-stream age-class structure compared with those in unburned streams. Despite the apparent effect on tadpoles, we do not expect the wildfire to be an extirpation threat to populations in the streams that we sampled. Studies spanning a chronosequence of fires, as well as in other areas, are needed to assess the effects of fires on streams with A. montanus and to determine the severity and persistence of these effects.

  2. Site and age class variation of hematologic parameters for female Greater Sage Grouse (Centrocercus urophasianus) of Northern Nevada.

    PubMed

    Dyer, Kathryn J; Perryman, Barry L; Holcombe, Dale W

    2010-01-01

    Decreases in Greater Sage Grouse (Centrocercus urophasianus) numbers throughout the western United States have been attributed to declining habitat quantity and quality. Improving our understanding of how interannual ecologic site variability affects nutritional status and fitness of different bird age classes will lead to improved land management and conservation strategies. Greater Sage Grouse were sampled from two Population Management Units located in northern Nevada, United States: Tuscarora (TU) and Lone Willow (LW) during 15 March-11 April 2004 and 14-20 March 2005. Twenty (16 yearlings, four adults) and 17 (7 yearlings, 10 adults) female Sage Grouse were captured and bled during 2004, and 12 (four yearlings, eight adults) and 14 (10 yearlings, four adults) were sampled during 2005 in TU and LW, respectively. Samples were evaluated to examine the effect of site, age, and year on specific hematologic and serum chemistry parameters. Several differences between age classes, sites, and years were detected for a number of fitness indicators; however, actual values fell within normal ranges of variation for Sage Grouse or other avian species. Differences were also detected for several parameters more closely related to reproductive fitness, including total plasma and serum proteins, and serum calcium and phosphorus. Yearlings had lower plasma protein (P<0.0001) and lower serum protein than did adults (P=0.0003). In 2004, TU yearlings had lower serum calcium levels than the adults, and in 2005, LW yearlings had lower levels than adults (P=0.008). Females on the TU site had lower serum phosphorus than the LW females (P<0.0001). Overall, adult females weighed more than yearlings (P=0.0004). Lower values found in yearlings, and on the TU management unit, indicate a lower production potential, particularly in unfavorable years. A lower intrinsic ability of yearlings to reproduce, combined with lower nutrition potentials and associated annual variations on certain types

  3. Inhibitory control efficiency in a Piaget-like class-inclusion task in school-age children and adults: a developmental negative priming study.

    PubMed

    Borst, G; Poirel, N; Pineau, A; Cassotti, M; Houdé, O

    2013-07-01

    Most children under 7 years of age presented with 10 daisies and 2 roses fail to indicate that there are more flowers than daisies. Instead of the appropriate comparison of the relative numerosities of the superordinate class (flowers) to its subordinate class (daisies), they perform a direct perceptual comparison of the extensions of the 2 subordinate classes (daisies vs. roses). In our experiment, we investigated whether increasing efficiency in solving the Piagetian class-inclusion task is related to increasing efficiency in the ability to resist (inhibit) this direct comparison of the subordinate classes' extensions. Ten-year-old and young adult participants performed a computerized priming version of a Piaget-like class-inclusion task. The experimental design was such that the misleading perceptual strategy to inhibit on the prime (in which a superordinate class had to be compared with a subordinate class) became a congruent strategy to activate on the probe (in which the two subordinate classes' extensions were directly compared). We found a negative priming effect of 291 ms in children and 129 ms in adults. These results provide evidence for the first time (a) that adults still need to inhibit the comparison of the subordinate classes' extensions in class-inclusion tasks and (b) that the ability to inhibit this heuristic increases with age (resulting in a lower executive cost). Taken together, these findings provide additional support for the neo-Piagetian approach of cognitive development that suggests that the acquisition of increasingly complex knowledge is based on the ability to resist (inhibit) heuristics and previously acquired knowledge. PMID:22889392

  4. Inhibitory control efficiency in a Piaget-like class-inclusion task in school-age children and adults: a developmental negative priming study.

    PubMed

    Borst, G; Poirel, N; Pineau, A; Cassotti, M; Houdé, O

    2013-07-01

    Most children under 7 years of age presented with 10 daisies and 2 roses fail to indicate that there are more flowers than daisies. Instead of the appropriate comparison of the relative numerosities of the superordinate class (flowers) to its subordinate class (daisies), they perform a direct perceptual comparison of the extensions of the 2 subordinate classes (daisies vs. roses). In our experiment, we investigated whether increasing efficiency in solving the Piagetian class-inclusion task is related to increasing efficiency in the ability to resist (inhibit) this direct comparison of the subordinate classes' extensions. Ten-year-old and young adult participants performed a computerized priming version of a Piaget-like class-inclusion task. The experimental design was such that the misleading perceptual strategy to inhibit on the prime (in which a superordinate class had to be compared with a subordinate class) became a congruent strategy to activate on the probe (in which the two subordinate classes' extensions were directly compared). We found a negative priming effect of 291 ms in children and 129 ms in adults. These results provide evidence for the first time (a) that adults still need to inhibit the comparison of the subordinate classes' extensions in class-inclusion tasks and (b) that the ability to inhibit this heuristic increases with age (resulting in a lower executive cost). Taken together, these findings provide additional support for the neo-Piagetian approach of cognitive development that suggests that the acquisition of increasingly complex knowledge is based on the ability to resist (inhibit) heuristics and previously acquired knowledge.

  5. [Anthropometric-nutritional status of a Spanish middle-class juvenile population. Study by age and sex groups].

    PubMed

    Gargallo Fernández, M A; de la Cruz Iglesias, A I; Garrudo Benito, D; de Cos Blanco, A I

    1993-01-01

    To make an initial approach to the current nutritional situation of the Spanish infant population, we carried out an anthropometric study of the children from 6 to 15 years of age in two schools in Fuenlabrada (Madrid) in a middle to lower class social environment. A total of 1,026 children were studied, to determine weight, height, tricipital fold and arm circumference. These parameters were used to calculate the weight/height ratio (w/h) and the muscular circumference of the arm. All these parameters were tabulated in percentile terms for comparison. The sample was divided into groups according to sex and to age (under 9, 9 to 12 and over 12). We found an overall w/h ratio of 108.8 +/- 17.4, more than the theoretical 100% (p < 0.001); 20.6% of the children over 120%. The Tricipital Fold (TFp) percentile was 62.5 +/- 27, with no differences according to age or sex. The percentile for arm muscular circumference (AMCp) was 48.8 +/- 27 for girls and 41.6 +/- 28 for boys (p < 0.001). Finally, we found a positive and significant correlation (p < 0.05) between w/h and AMCp (r = 0.51) and between w/h and TFp (r = 0.57). We conclude that the population studied is significantly overweight, confirming previous studies. Girls showed better nutritional parameters than the boys, apparently less nutritionally affected by the middle to low social environment. Finally, the w/h ratio, as an isolated parameter, is a good overall index of the nutritional state of children.

  6. CLASS 0 PROTOSTARS IN THE PERSEUS MOLECULAR CLOUD: A CORRELATION BETWEEN THE YOUNGEST PROTOSTARS AND THE DENSE GAS DISTRIBUTION

    SciTech Connect

    Sadavoy, S. I.; Di Francesco, J.; André, Ph.; Maury, A.; Men'shchikov, A.; Motte, F.; Hennemann, M.; Könyves, V.; Louvet, F.; Roy, A.; Bernard, J.-P.; Nguyên-Lu'o'ng, Q.; Schneider, N.; Bontemps, S.; Arzoumanian, D.; Hill, T.; Peretto, N.; and others

    2014-06-01

    We use PACS and SPIRE continuum data at 160 μm, 250 μm, 350 μm, and 500 μm from the Herschel Gould Belt Survey to sample seven clumps in Perseus: B1, B1-E, B5, IC 348, L1448, L1455, and NGC 1333. Additionally, we identify and characterize the embedded Class 0 protostars using detections of compact Herschel sources at 70 μm as well as archival Spitzer catalogs and SCUBA 850 μm photometric data. We identify 28 candidate Class 0 protostars, four of which are newly discovered sources not identified with Spitzer. We find that the star formation efficiency of clumps, as traced by Class 0 protostars, correlates strongly with the flatness of their respective column density distributions at high values. This correlation suggests that the fraction of high column density material in a clump reflects only its youngest protostellar population rather than its entire source population. We propose that feedback from either the formation or evolution of protostars changes the local density structure of clumps.

  7. The Age, Mass, and Size Distributions of Star Clusters in M51

    NASA Astrophysics Data System (ADS)

    Chandar, Rupali; Whitmore, Bradley C.; Dinino, Daiana; Kennicutt, Robert C.; Chien, L.-H.; Schinnerer, Eva; Meidt, Sharon

    2016-06-01

    We present a new catalog of 3816 compact star clusters in the grand design spiral galaxy M51 based on observations taken with the Hubble Space Telescope. The age distribution of the clusters declines starting at very young ages, and can be represented by a power law, {dN}/dτ \\propto {τ }γ , with γ =-0.65+/- 0.15. No significant changes in the shape of the age distribution at different masses is observed. The mass function of the clusters younger than τ ≈ 400 {{Myr}} can also be described by a power law, {dN}/{dM}\\propto {M}β , with β ≈ \\-2.1+/- 0.2. We compare these distributions with the predictions from various cluster disruption models, and find that they are consistent with models where clusters disrupt approximately independent of their initial mass, but not with models where lower mass clusters are disrupted earlier than their higher mass counterparts. We find that the half-light radii of clusters more massive than M ≈ 3× {10}4 {M}⊙ and with ages between 100 and 400 {{Myr}} are larger by a factor of ≈3-4 than their counterparts that are younger than 107 years old, suggesting that the clusters physically expand during their early life.

  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. Distribution of immunoglobulin classes and IgG subclasses against a culture filtrate antigen of Burkholderia pseudomallei in melioidosis patients.

    PubMed

    Chenthamarakshan, V; Kumutha, M V; Vadivelu, J; Puthucheary, S D

    2001-01-01

    The class and subclass distribution of antibody response to the culture filtrate antigen (CFA) of Burkholderia pseudomallei was examined in the sera of 45 septicaemic and 17 localised melioidosis cases and 40 cases clinically suspected of melioidosis and the results were compared with those from high-risk and healthy control groups. The geometric mean titre index (GMTI) values for all classes and subclasses of immunoglobulins examined were higher for sera from the proven and clinically suspected melioidosis cases than for the control groups. However, the highest response in the three patient groups was that of IgG with GMTIs ranging from 219.4 to 291.6 and the lowest was for IgM with GMTIs of 22.5, 24.3 and 28.7. The IgA response was intermediate with GMTIs ranging from 119.2 to 170. The GMTIs were highest for IgG in septicaemic and localised infections and for IgA and IgM in localised infections. As regards IgG subclass distribution, IgG1 and IgG2 were the predominant subclasses produced against the CFA in contrast to IgG3 and IgG4, which were produced in low amounts. None of the sera from the control groups had any significant titres of antibodies.

  10. 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

  11. The Coming of age of Low-cost Nanosatellites as Enablers for Constellation-class Space Weather Networks

    NASA Astrophysics Data System (ADS)

    Klumpar, D. M.

    2006-12-01

    Recent progress in the development of satellite-borne space science instrumentation has focused on increased sophistication resulting in a tremendous increase in understanding of microphysical processes in space. These tremendous advancements, however, have been made without sufficient concomitant experimental characterization of the dynamic behavior of the large-scale geospace system. Global theoretical models of the geospace system need distributed measurements for authentication. Thus there is a need to acquire in-situ space weather data at higher spatio-temporal density than currently planned. Nanosatellites (i.e. 1-10 kg spacecraft) have emerged as technically capable carriers for a variety of on-orbit missions. Advances in electronic miniaturization, reductions in power consumption, increased communications capabilities and miniaturized propulsion systems for station-keeping have enabled development of highly capable miniature satellite buses. Led primarily by universities, kg-class satellites have been developed and launched for a variety of purposes. As recently as July 2006, 18 satellites were lost in a launch booster failure in what was billed as the single largest cluster launch of satellites to date. Thirteen of the 14 one kg-class satellites in this cluster launch were designed, developed, and built in university laboratories. They were built at a fraction of the cost of typical satellites. While, in this instance, these 14 satellites had, for the most part, unrelated mission goals it is perfectly reasonable to envision that a launch of several dozen related satellites is technically feasible at a cost much lower than studies based on traditional methods have shown. This paper will review current nanosatellite capabilities and explore the application of constellations of nanosatellies as carriers of relatively unsophisticated space weather instruments where the value lies in the ability to make a network of measurements that provide unprecedented

  12. Fast Airborne Size Distribution Measurements of an Aerosol Processes and Aging

    NASA Astrophysics Data System (ADS)

    Kapustin, V.; Clarke, A. D.; Zhou, J.; Brekhovskikh, V.; McNaughton, C. S.; Howell, S.

    2009-12-01

    During MILAGRO/INTEX experiment the Hawaii Group for Environmental Aerosol Research (HIGEAR) deployed a wide range of aerosol instrumentation aboard NSF C-130 and NASA DC-8. These were designed to provide rapid information on aerosol composition, state of mixing (internal or external), spectral optical properties (scattering and absorption), the humidity dependence of light scattering - f(RH), and the role of condensed species in changing the absorption properties of black carbon (BC) and inferred properties of organic carbon (OC). We also flew the Fast Mobility Particle Spectrometer (FMPS, TSI Inc.) to measure aerosol size distributions in a range 5.6 - 560 nm. For all our flights around Mexico City, an aerosol number concentration usually was well above the nominal FMPS sensitivity (from ~100 particles/cc @ Dp = 5.6 nm to 1 part/cc @ 560nm), providing us with reliable size distributions even at 1 sec resolution. FMPS measurements revealed small scale structure of an aerosol and allowed us to examine size distributions varying over space and time associated with mixing processes previously unresolved. These 1-Hz measurements during aircraft profiles captured variations in size distributions within shallow layers. Other dynamic processes observed included orography induced aerosol layers and evolution of the nanoparticles formed by nucleation. We put FMPS high resolution size distribution data in a context of aerosol evolution and aging, using a range of established (for MIRAGE/INTEX) chemical, aerosol and transport aging parameters.

  13. Strain Distribution in a Kennedy Class I Implant Assisted Removable Partial Denture under Various Loading Conditions

    PubMed Central

    Shahmiri, Reza; Aarts, John M.; Bennani, Vincent; Swain, Michael V.

    2013-01-01

    Purpose. This in vitro study investigates how unilateral and bilateral occlusal loads are transferred to an implant assisted removable partial denture (IARPD). Materials and Methods. A duplicate model of a Kennedy class I edentulous mandibular arch was made and then a conventional removable partial denture (RPD) fabricated. Two Straumann implants were placed in the second molar region, and the prosthesis was modified to accommodate implant retained ball attachments. Strain gages were incorporated into the fitting surface of both the framework and acrylic to measure microstrain (μStrain). The IARPD was loaded to 120Ns unilaterally and bilaterally in three different loading positions. Statistical analysis was carried out using SPSS version 18.0 (SPSS, Inc., Chicago, IL, USA) with an alpha level of 0.05 to compare the maximum μStrain values of the different loading conditions. Results. During unilateral and bilateral loading the maximum μStrain was predominantly observed in a buccal direction. As the load was moved anteriorly the μStrain increased in the mesial area. Unilateral loading resulted in a twisting of the structure and generated a strain mismatch between the metal and acrylic surfaces. Conclusions. Unilateral loading created lateral and vertical displacement of the IARPD. The curvature of the dental arch resulted in a twisting action which intensified as the unilateral load was moved anteriorly. PMID:23737788

  14. 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.

  15. Spatial and temporal simulation of groundwater age distributions of a small mountainous catchment

    NASA Astrophysics Data System (ADS)

    Gundel, Anita; Weiler, Markus; Schirmer, Mario

    2013-04-01

    The spatial and temporal storage characteristics of catchments are relevant to identify the vulnerability of catchments to climate change. Areas with high mean groundwater ages imply long residence times of water particles in the aquifer and are therefore a good indicator for high storage capacity of a catchment. Groundwater age in general is strongly influenced by porosity, flow direction and flow velocity. Hence, the great challenge for moutainous catchments is the steep topography and the complex geology which has the greatest impact on the groundwater age distribution. The main purpose of this study is the simulation of the groundwater age of a well-instrumented pre-alpine catchment in time and space to identify storage characteristics. One possibility to simulate groundwater age distributions in space and time is the application of a numerical groundwater model, which takes into account complex geological structures as well as the flow and transport processes of the unsaturated and saturated zone. In our study, we used the numerical 3D-finite-element groundwater flow and transport model FEFLOW with a transient direct mean age simulation method based on a mass-weighted average age. The study catchment Rietholzbach is located in the north-east of Switzerland, for which an adequate data set of discharge, groundwater level, and isotopic composition of the groundwater and stream water exists. First of all, a steady-state groundwater flow model was developed to validate the stability and accuracy of the flow simulation and model structure. Secondly, the steady-state results provide the initial conditions for the transient flow and transport simulation of the groundwater age distribution. Residence time simulations of this model were benchmarked against the stable isotope signal δ18O of groundwater and discharge. The results show that less water is stored along the creek in the shallow aquifer (young water) whereas substantial storage capacities (old water) are

  16. SAT-Based (Parametric) Reachability for a Class of Distributed Time Petri Nets

    NASA Astrophysics Data System (ADS)

    Penczek, Wojciech; Pòłrola, Agata; Zbrzezny, Andrzej

    Formal methods - among them the model checking techniques - play an important role in the design and production of both systems and software. In this paper we deal with an adaptation of the bounded model checking methods for timed systems, developed for timed automata, to the case of time Petri nets. We consider distributed time Petri nets and parametric reachability checking, but the approach can be easily adapted to verification of other kinds of properties for which the bounded model checking methods exist. A theoretical description is supported by some experimental results, generated using an extension of the model checker verICS.

  17. The Work of Power and the Power of Work: Teaching for Class Consciousness in the Neo-Liberal Age

    ERIC Educational Resources Information Center

    Weiner, Eric J.

    2004-01-01

    As workers throughout the globe struggle to gain control over the conditions in which they labor as well as the means by which capital is produced, the importance of understanding class struggle, class formation and class consciousness as they relate to education and schooling takes on a new urgency. In the early part of the twenty-first century,…

  18. Leaf area and light use efficiency patterns of Norway spruce under different thinning regimes and age classes

    PubMed Central

    Gspaltl, Martin; Bauerle, William; Binkley, Dan; Sterba, Hubert

    2013-01-01

    Silviculture focuses on establishing forest stand conditions that improve the stand increment. Knowledge about the efficiency of an individual tree is essential to be able to establish stand structures that increase tree resource use efficiency and stand level production. Efficiency is often expressed as stem growth per unit leaf area (leaf area efficiency), or per unit of light absorbed (light use efficiency). We tested the hypotheses that: (1) volume increment relates more closely with crown light absorption than leaf area, since one unit of leaf area can receive different amounts of light due to competition with neighboring trees and self-shading, (2) dominant trees use light more efficiently than suppressed trees and (3) thinning increases the efficiency of light use by residual trees, partially accounting for commonly observed increases in post-thinning growth. We investigated eight even-aged Norway spruce (Picea abies (L.) Karst.) stands at Bärnkopf, Austria, spanning three age classes (mature, immature and pole-stage) and two thinning regimes (thinned and unthinned). Individual leaf area was calculated with allometric equations and absorbed photosynthetically active radiation was estimated for each tree using the three-dimensional crown model Maestra. Absorbed photosynthetically active radiation was only a slightly better predictor of volume increment than leaf area. Light use efficiency increased with increasing tree size in all stands, supporting the second hypothesis. At a given tree size, trees from the unthinned plots were more efficient, however, due to generally larger tree sizes in the thinned stands, an average tree from the thinned treatment was superior (not congruent in all plots, thus only partly supporting the third hypothesis). PMID:25540477

  19. 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.

  20. 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.

  1. Spectral class distribution of circumstellar material in main-sequence stars

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.

    1988-01-01

    A detailed statistical evaluation of IRAS survey data of main-sequence stars within 25 pc indicates that the presence of cool shells around A, F, and G main-sequence stars is the rule, rather than the exception. While luminosity bias favors A and F stars, the typical G star still appears to have almost three orders of magnitude more excess than the excess of the solar system due to known zodiacal dust and all planets combined. The Vega effect is thus not restricted to stars of particularly young age. The finding that the 'archetypical' solar system appears to have much less far-IR excess than the majority of G stars supports a speculation that the sun could have a cloud of cold particles beyond the outer planets, undetected by IRAS viewing from earth.

  2. Age-related changes in endothelial permeability and distribution volume of albumin in rat aorta.

    PubMed

    Belmin, J; Corman, B; Merval, R; Tedgui, A

    1993-03-01

    Age-related changes in macromolecular transport across the arterial wall were investigated in 10-, 20-, and 30-mo-old WAG/Rij rats. Animals were injected with 125I- and 131I-labeled albumin, 90 and 5 min before they were killed, respectively. The transmural distribution of relative concentration of tracers in the aortic wall was obtained using en face serial sectioning technique. The apparent endothelial permeability to albumin calculated from the distribution of 5-min 131I-labeled albumin concentrations was significantly enhanced in 20- and 30-mo-old rats compared with 10-mo-old rats. The apparent distribution volume of albumin within the media, estimated as the mean medial 125I-labeled albumin concentration, was not significantly changed in 20-mo-old rats but was significantly decreased in the 30-mo-old animals. These age-related changes in the macromolecular transport suggest that the entry of plasma macromolecules in the aged arterial wall might be enhanced, whereas the efflux through the media may be impeded, possibly contributing to their trapping in the subendothelium. PMID:8456970

  3. Carbon-based phytoplankton size classes retrieved via ocean color estimates of the particle size distribution

    NASA Astrophysics Data System (ADS)

    Kostadinov, T. S.; Milutinović, S.; Marinov, I.; Cabré, A.

    2015-05-01

    Owing to their important roles in biogeochemical cycles, phytoplankton functional types (PFTs) have been the aim of an increasing number of ocean color algorithms. Yet, none of the existing methods are based on phytoplankton carbon (C) biomass, which is a fundamental biogeochemical and ecological variable and the "unit of accounting" in Earth System models. We present a novel bio-optical algorithm to retrieve size-partitioned phytoplankton carbon from ocean color satellite data. The algorithm is based on existing algorithms to estimate particle volume from a power-law particle size distribution (PSD). Volume is converted to carbon concentrations using a compilation of allometric relationships. We quantify absolute and fractional biomass in three PFTs based on size - picophytoplankton (0.5-2 μm in diameter), nanophytoplankton (2-20 μm) and microphytoplankton (20-50 μm). The mean spatial distributions of total phytoplankton C biomass and individual PFTs, derived from global SeaWiFS monthly ocean color data, are consistent with current understanding of oceanic ecosystems, i.e. oligotrophic regions are characterized by low biomass and dominance of picoplankton, whereas eutrophic regions have large biomass to which nanoplankton and microplankton contribute relatively larger fractions. Global spatially integrated phytoplankton carbon biomass standing stock estimates using our PSD-based approach yield on average ~0.2-0.3 Gt of C, consistent with analogous estimates from two other ocean color algorithms, and several state-of-the-art Earth System models. However, the range of phytoplankton C biomass spatial variability globally is larger than estimated by any other models considered here, because the PSD-based algorithm is not a priori empirically constrained and introduces improvement over the assumptions of the other approaches. Satisfactory in situ closure observed between PSD and POC measurements lends support to the theoretical basis of the PSD-based algorithm

  4. A comprehensive study of metal distribution in three main classes of seaweed.

    PubMed

    Ryan, Siobhan; McLoughlin, Peter; O'Donovan, Orla

    2012-08-01

    This paper provides one of the most comprehensive studies of metal distributions in three main macroalgae species. In this novel study, levels of total, intracellular and surface bound Pb, Zn, As, Cd, Co, Cr, Cu, Mn and Ni associated with Polysiphonia lanosa (L) Tandy, Ascophyllum nodosum (L) Le Jolis, Fucus vesiculosus (L) and Ulva sp. were determined. Additionally, water and sediment metal levels were analysed to gain an insight into the relative uptake efficiencies of different macroalgal species. Samples were collected from a clean site in Fethard-on-Sea, Wexford, Ireland (52°11'53.68'N, 6°49'34.64'W), in May 2008. Results demonstrated that total, intracellular and surface bound metal levels varied according to metal and seaweed species, with the highest proportion of metals found to be intracellular. Inhibition of Mn uptake by Zn was indicated for P. lanosa. Furthermore, P. lanosa had enhanced bioaccumulation ability, with the highest Concentration Factor reported of any seaweed to date. PMID:22575098

  5. 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.

  6. Mapping post-disturbance stand age distribution in Siberian larch forest based on a novel method

    NASA Astrophysics Data System (ADS)

    Chen, D.; Loboda, T. V.; Krylov, A.; Potapov, P.

    2014-12-01

    The Siberian larch forest, which accounts for nearly 20% of the global boreal forest biome, is unique, important, yet significantly understudied. These deciduous needleleaf forests with a single species dominance over a large continuous area are not found anywhere except the extreme continental zones of Siberia and the Russian Far East. Most of these forests are located in remote and sparsely populated areas and, therefore, little is known about spatial variability of their structure and dynamics. Wall-to-wall repeated observations of this area are available only since the 2000s. Previously, we developed methods for reconstruction of stand-age distribution from a sample of 1980-2000 disturbances in Landsat TM and ETM+ imagery. However, availability of those images in Siberian larch forests is particularly limited. Built upon the hypothesis that the spectral characteristics of the disturbed forest in the region change with time consistently, this paper proposes a novel method utilizing the newly released Global Forest Change (GFC) 2000-2012 dataset. We exploit the data-rich era of annual forest disturbance samples identified between 2000 and 2012 in the Siberian larch forest by the GFC dataset to build a robust training set of spectral signatures from regrowing larch forests as they appear in Landsat imagery in 2012. The extracted statistics are ingested into a random forest, which predicts the approximate stand age for every forested pixel in the circa 2000 composite. After merging the estimated stand age distribution for 1989-2000 with the observed disturbance records for 2001-2012, a gap-free 30 m resolution 24-year long record of stand age distribution is obtained. A preliminary accuracy assessment against the Advanced Very High Resolution Radiometer (AVHRR) burned area product suggested satisfactory performance of the proposed method.

  7. Variation of Meat Quality Parameters Due to Conformation and Fat Class in Limousin Bulls Slaughtered at 25 to 27 Months of Age

    PubMed Central

    Guzek, Dominika; Głąska, Dominika; Pogorzelski, Grzegorz; Kozań, Karolina; Pietras, Jacek; Konarska, Małgorzata; Sakowska, Anna; Głąski, Krzysztof; Pogorzelska, Ewelina; Barszczewski, Jerzy; Wierzbicka, Agnieszka

    2013-01-01

    The aim of the present study was to determine the influence of age of animal, hot carcass weight, pH, conformation and fat class on basic beef quality attributes (tenderness, sarcomere length, basic chemical composition, marbling and colour) in a group of purebred animals. The object of the study was beef of Limousin bulls (25 to 27 months, hot carcass weight - 432±31 kg, “U” conformation class, “2”–“3” fat class). Analysed cuts were Infraspinatus muscle from the blade and Longissimus dorsi muscle from the cube roll and the striploin. Tenderness was analysed with universal testing machine, colour - chromometer analysis, sarcomere length - microscopic method, basic chemical composition - near-infrared spectroscopy and marbling - computer image analysis. No differences in tenderness and sarcomere length were observed within the age groups of Limousin bulls (age of 25, 26, 27 months) (p>0.05). Moisture (p = 0.0123) and fat (p = 0.0250) content were significantly different for meat of animals slaughtered at the age of 25 and 27 months. No influence of pH value on tenderness was observed, but at the same time, influence on sarcomere length (p = 0.039) and b* component of colour (0.045) was found. For “U” conformation class, in subclasses, as well as for fat classes “2”–“3”, there were no differences in tenderness, sarcomere length and colour components. Higher fat content was observed in the higher fat class, rather than in lower, however this feature was not associated with marbling. PMID:25049844

  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.

  9. 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

  10. 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.

  11. Epigenetic contribution to age distribution of mortality within the Penna model.

    PubMed

    Magdoń-Maksymowicz, M S; Maksymowicz, A Z

    2015-06-01

    Some modifications of the simple asexual Penna model, enriched by epigenetic contributions, are presented. The standard bit-string Penna model of biological aging and population evolution is based on an inherited DNA structure which defines the future life of a newly born individuals, when genes are activated by the biological clock, and the predefined genetic death is fully controlled by the number of defected genes. Epigenomes allow to introduce additional mechanism of gene activation or silencing without affecting the DNA genome itself. It may be either inherited or may reflect external, environmental factors. In the presented model, information read from the introduced epigenome may alter gene expression that may be stopped or re-activated. We concentrate on the influence of epigenetics on the age a distribution of genetic mortality m(a). Changes in m(a) are strong for the case of inherited epigenetic contribution with nearly perfect inheritance and 'positive' epigenome that partly ignores the 'bad' mutations. We conclude that the epigenetic contribution may influence population structure m(a) and could be, at least partly, responsible for deviation of m(a) distribution from the Gompertz law. In short, we claim that proposed epigenetic contribution may be seen as a candidate for possible explanation of observed deviation from the Gompertz law, also among senior members of society. A very simple model was used in this paper and many crucial mechanisms of biological aging were omitted. Therefore, further work based on a more realistic models is necessary. PMID:25666268

  12. Differential Predation by Age and Sex Classes in Blue Wildebeest in Serengeti: Study of a Modern Carnivore Den in Olduvai Gorge (Tanzania)

    PubMed Central

    Arriaza, Mari Carmen; Domínguez-Rodrigo, Manuel; Martínez-Maza, Cayetana; Mabulla, Audax; Baquedano, Enrique

    2015-01-01

    Age and sex selection of prey is an aspect of predator ecology which has been extensively studied in both temperate and African ecosystems. This dimension, along with fecundity, survival rates of prey and mortality factors other than predation are important in laying down the population dynamics of prey and have important implications in the management of species. A carnivore den located in the short-grassland ecological unit of the Serengeti was studied. Sex- and age- class (using five age categories) of the wildebeest remains recovered were analyzed through horn morphology, biometrics of the bones and tooth wear patterns. We compared our results with previous studies from lion and hyaena kills through multivariate analyses. Seasonality of the accumulation was analyzed through tooth histology. PCA and CVA results show that age class selection by predators depends on season, habitat-type, and growth rate of the wildebeest population. Female-biased predation was found to contradict classical hypotheses based on territorial male behaviour. The lion and spotted hyaena showed strong selection on age classes, contrary to previous studies. Migratory wildebeest sex ratio is regulated through differential predation by seasons and female deaths in the wet season are a trade-off for population stability. These data are crucial for an effective management of the species and the new method created may be useful for different carnivore species and their prey. PMID:26017363

  13. Differential predation by age and sex classes in blue wildebeest in Serengeti: study of a modern carnivore den in Olduvai Gorge (Tanzania).

    PubMed

    Arriaza, Mari Carmen; Domínguez-Rodrigo, Manuel; Martínez-Maza, Cayetana; Mabulla, Audax; Baquedano, Enrique

    2015-01-01

    Age and sex selection of prey is an aspect of predator ecology which has been extensively studied in both temperate and African ecosystems. This dimension, along with fecundity, survival rates of prey and mortality factors other than predation are important in laying down the population dynamics of prey and have important implications in the management of species. A carnivore den located in the short-grassland ecological unit of the Serengeti was studied. Sex- and age- class (using five age categories) of the wildebeest remains recovered were analyzed through horn morphology, biometrics of the bones and tooth wear patterns. We compared our results with previous studies from lion and hyaena kills through multivariate analyses. Seasonality of the accumulation was analyzed through tooth histology. PCA and CVA results show that age class selection by predators depends on season, habitat-type, and growth rate of the wildebeest population. Female-biased predation was found to contradict classical hypotheses based on territorial male behaviour. The lion and spotted hyaena showed strong selection on age classes, contrary to previous studies. Migratory wildebeest sex ratio is regulated through differential predation by seasons and female deaths in the wet season are a trade-off for population stability. These data are crucial for an effective management of the species and the new method created may be useful for different carnivore species and their prey. PMID:26017363

  14. Differential predation by age and sex classes in blue wildebeest in Serengeti: study of a modern carnivore den in Olduvai Gorge (Tanzania).

    PubMed

    Arriaza, Mari Carmen; Domínguez-Rodrigo, Manuel; Martínez-Maza, Cayetana; Mabulla, Audax; Baquedano, Enrique

    2015-01-01

    Age and sex selection of prey is an aspect of predator ecology which has been extensively studied in both temperate and African ecosystems. This dimension, along with fecundity, survival rates of prey and mortality factors other than predation are important in laying down the population dynamics of prey and have important implications in the management of species. A carnivore den located in the short-grassland ecological unit of the Serengeti was studied. Sex- and age- class (using five age categories) of the wildebeest remains recovered were analyzed through horn morphology, biometrics of the bones and tooth wear patterns. We compared our results with previous studies from lion and hyaena kills through multivariate analyses. Seasonality of the accumulation was analyzed through tooth histology. PCA and CVA results show that age class selection by predators depends on season, habitat-type, and growth rate of the wildebeest population. Female-biased predation was found to contradict classical hypotheses based on territorial male behaviour. The lion and spotted hyaena showed strong selection on age classes, contrary to previous studies. Migratory wildebeest sex ratio is regulated through differential predation by seasons and female deaths in the wet season are a trade-off for population stability. These data are crucial for an effective management of the species and the new method created may be useful for different carnivore species and their prey.

  15. Development of integrated damage detection system for international America's Cup class yacht structures using a fiber optic distributed sensor

    NASA Astrophysics Data System (ADS)

    Akiyoshi, Shimada; Naruse, Hiroshi; Uzawa, Kyoshi; Murayama, Hideaki; Kageyama, Kazuro

    2000-06-01

    We constructed a new health monitoring system to detect damage using a fiber optic distributed sensor, namely a Brillouin optical time domain reflectometer (BOTDR), and installed it in International America's Cup Class (IACC) yachts, the Japanese entry in America's Cup 2000. IACC yachts are designed to be as fast as possible, so it is essential that they are lightweight and encounter minimum water resistance. Advanced composite sandwich structures, made with carbon fiber reinforced plastic (CFRP) skins and a honeycomb core, are used to achieve the lightweight structure. Yacht structure designs push the strength of the materials to their limit and so it is important to detect highly stressed or damaged regions that might cause a catastrophic fracture. The BOTDR measures changes in the Brillouin frequency shift caused by distributed strain along one optical fiber. We undertook two experiments: a pulling test and a four point bending test on a composite beam. The former showed that no slippage occurred between the optical fiber glass and its coating. The latter confirmed that a debonding between the skin and the core of 300 mm length could be found with the BOTDR. Next we examined the effectiveness with which this system can assess the structural integrity of IACC yachts. The results show that our system has the potential for use as a damage detection system for smart structures.

  16. Social Class and Income Inequality in the United States: Ownership, Authority, and Personal Income Distribution from 1980 to 2010.

    PubMed

    Wodtke, Geoffrey T

    2016-03-01

    This study outlines a theory of social class based on workplace ownership and authority relations, and it investigates the link between social class and growth in personal income inequality since the 1980s. Inequality trends are governed by changes in between-class income differences, changes in the relative size of different classes, and changes in within-class income dispersion. Data from the General Social Survey are used to investigate each of these changes in turn and to evaluate their impact on growth in inequality at the population level. Results indicate that between-class income differences grew by about 60% since the 1980s and that the relative size of different classes remained fairly stable. A formal decomposition analysis indicates that changes in the relative size of different social classes had a small dampening effect and that growth in between-class income differences had a large inflationary effect on trends in personal income inequality.

  17. Social Class and Income Inequality in the United States: Ownership, Authority, and Personal Income Distribution from 1980 to 2010.

    PubMed

    Wodtke, Geoffrey T

    2016-03-01

    This study outlines a theory of social class based on workplace ownership and authority relations, and it investigates the link between social class and growth in personal income inequality since the 1980s. Inequality trends are governed by changes in between-class income differences, changes in the relative size of different classes, and changes in within-class income dispersion. Data from the General Social Survey are used to investigate each of these changes in turn and to evaluate their impact on growth in inequality at the population level. Results indicate that between-class income differences grew by about 60% since the 1980s and that the relative size of different classes remained fairly stable. A formal decomposition analysis indicates that changes in the relative size of different social classes had a small dampening effect and that growth in between-class income differences had a large inflationary effect on trends in personal income inequality. PMID:27087695

  18. 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.

  19. 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

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

    PubMed

    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

  1. Prevalence, age distribution and aetiology of bronchiectasis: a retrospective study on 144 symptomatic patients.

    PubMed

    Scala, R; Aronne, D; Palumbo, U; Montella, L; Giacobbe, R; Martucci, P; Del Prato, B

    2000-04-01

    The incidence of bronchiectasis (BCT) has probably decreased in developed countries in recent years, but reliable statistical data on its occurrence are still lacking. The aim of the present study was to retrospectively evaluate the prevalence, age distribution and aetiology of BCT, diagnosed in a selected series of symptomatic patients of a Western country by using bronchography. The authors analysed the main known predisposing and associated conditions (PACs), and the occurrence and age distribution of BCT in 144 consecutive patients who underwent bronchological examination (fibreoptic bronchoscopy and bronchography) in the years 1987-1994 because of recurrent purulent bronchitis and/or haemoptysis. The overall prevalence of BCT was 34% (49/144); its age distribution was: 17.2% (0-10 yrs), 43.7% (11-20 yrs), 38% (21-30 yrs), 37.5% (31-40 yrs), 33.3% (41-50 yrs), 40% (51-60 yrs), and 20% (61-70 yrs). Thirty-one PACs were found in 29/144 patients of the whole study group. The prevalence of BCT was significantly higher in the subgroup of 29 patients with PACs than in the subgroup of 115 patients without PACs (75.9% versus 23.5%; p < 0000001). The aetiology of BCT was mainly unexplained, as it was only possible to detect 24 PACs in 22/49 patients with BCT (44.9%): congenital, genetic and immune disorders (eight), localized airways obstructive diseases (five), pulmonary infections (three), bronchial asthma (two), pulmonary lobar fibrosis (two), ulcerative colitis (two), dermatomiositis (one), and toxin inhalation (one). The authors conclude that bronchiectasis still occurs in a large percentage of symptomatic patients of a developed country in the post-antimicrobial era, especially in the second to sixth decades, as well as in the presence of predisposing and associated conditions; its aetiology remains unknown in more than half of cases.

  2. 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.

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

    PubMed

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

    2004-01-01

    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.

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

    USGS Publications Warehouse

    Jurgens, Bryant; Bohlke, 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.

  5. The MHC class II ligand lymphocyte activation gene-3 is co-distributed with CD8 and CD3-TCR molecules after their engagement by mAb or peptide-MHC class I complexes.

    PubMed

    Hannier, S; Triebel, F

    1999-11-01

    Previous studies indicated that signaling through lymphocyte activation gene-3 (LAG-3), a MHC class II ligand, induced by multivalent anti-receptor antibodies led to unresponsiveness to TCR stimulation. Here, lateral distribution of the LAG-3 molecules and its topological relationship (mutual proximity) to the TCR, CD8, CD4, and MHC class I and II molecules were studied in the plasma membrane of activated human T cells in co-capping experiments and conventional fluorescence microscopy. Following TCR engagement by either TCR-specific mAb or MHC-peptide complex recognition in T-B cell conjugates, LAG-3 was found to be specifically associated with the CD3-TCR complex. Similarly, following CD8 engagement LAG-3 and CD8 were co-distributed on the cell surface while only a low percentage of CD4-capped cells displayed LAG-3 co-caps. In addition, LAG-3 was found to be associated with MHC class II (i.e. DR, DP and DQ) and partially with MHC class I molecules. The supramolecular assemblies described here between LAG-3, CD3, CD8 and MHC class II molecules may result from an organization in raft microdomains, a phenomenon known to regulate early events of T cell activation.

  6. Effect of backpack position on foot weight distribution of school-aged children

    PubMed Central

    Kim, Kyung; Kim, Chang Ju; Oh, Duck-Won

    2015-01-01

    [Purpose] In the present study, we aimed to determine the effects of backpack position on foot weight distribution of standing school-aged children. [Subjects] Thirty school-aged children volunteered to participate in this study. [Methods] The subjects randomly performed four types of carrying a backpack: no backpack (condition-1), carrying a backpack at C7 (condition-2), carrying a backpack at 10 cm below C7 (condition-3), and carrying a backpack at 20 cm below C7 (condition-4). [Results] Statistically significant differences were noted in the anterior and posterior pressure values, and in the anterior-to-posterior ratio, among the four conditions (p < 0.05). Post-hoc analysis indicated that the pressure value of condition-4 was significantly lower in the anterior foot region and higher in the posterior foot region than in condition-2 and condition-3. In addition, the anterior-to-posterior ratio was lower in condition-4 than in condition-2 and condition-3. [Conclusion] These findings suggest that carrying a backpack in a higher position, with fastening of the shoulder strap, may be more favorable for normalizing the foot weight distribution. PMID:25931722

  7. Effect of backpack position on foot weight distribution of school-aged children.

    PubMed

    Kim, Kyung; Kim, Chang Ju; Oh, Duck-Won

    2015-03-01

    [Purpose] In the present study, we aimed to determine the effects of backpack position on foot weight distribution of standing school-aged children. [Subjects] Thirty school-aged children volunteered to participate in this study. [Methods] The subjects randomly performed four types of carrying a backpack: no backpack (condition-1), carrying a backpack at C7 (condition-2), carrying a backpack at 10 cm below C7 (condition-3), and carrying a backpack at 20 cm below C7 (condition-4). [Results] Statistically significant differences were noted in the anterior and posterior pressure values, and in the anterior-to-posterior ratio, among the four conditions (p < 0.05). Post-hoc analysis indicated that the pressure value of condition-4 was significantly lower in the anterior foot region and higher in the posterior foot region than in condition-2 and condition-3. In addition, the anterior-to-posterior ratio was lower in condition-4 than in condition-2 and condition-3. [Conclusion] These findings suggest that carrying a backpack in a higher position, with fastening of the shoulder strap, may be more favorable for normalizing the foot weight distribution. PMID:25931722

  8. 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.

  9. Societal preferences for distributive justice in the allocation of health care resources: a latent class discrete choice experiment.

    PubMed

    Skedgel, Chris; Wailoo, Allan; Akehurst, Ron

    2015-01-01

    Economic theory suggests that resources should be allocated in a way that produces the greatest outputs, on the grounds that maximizing output allows for a redistribution that could benefit everyone. In health care, this is known as QALY (quality-adjusted life-year) maximization. This justification for QALY maximization may not hold, though, as it is difficult to reallocate health. Therefore, the allocation of health care should be seen as a matter of distributive justice as well as efficiency. A discrete choice experiment was undertaken to test consistency with the principles of QALY maximization and to quantify the willingness to trade life-year gains for distributive justice. An empirical ethics process was used to identify attributes that appeared relevant and ethically justified: patient age, severity (decomposed into initial quality and life expectancy), final health state, duration of benefit, and distributional concerns. Only 3% of respondents maximized QALYs with every choice, but scenarios with larger aggregate QALY gains were chosen more often and a majority of respondents maximized QALYs in a majority of their choices. However, respondents also appeared willing to prioritize smaller gains to preferred groups over larger gains to less preferred groups. Marginal analyses found a statistically significant preference for younger patients and a wider distribution of gains, as well as an aversion to patients with the shortest life expectancy or a poor final health state. These results support the existence of an equity-efficiency tradeoff and suggest that well-being could be enhanced by giving priority to programs that best satisfy societal preferences. Societal preferences could be incorporated through the use of explicit equity weights, although more research is required before such weights can be used in priority setting. PMID:25145575

  10. Societal preferences for distributive justice in the allocation of health care resources: a latent class discrete choice experiment.

    PubMed

    Skedgel, Chris; Wailoo, Allan; Akehurst, Ron

    2015-01-01

    Economic theory suggests that resources should be allocated in a way that produces the greatest outputs, on the grounds that maximizing output allows for a redistribution that could benefit everyone. In health care, this is known as QALY (quality-adjusted life-year) maximization. This justification for QALY maximization may not hold, though, as it is difficult to reallocate health. Therefore, the allocation of health care should be seen as a matter of distributive justice as well as efficiency. A discrete choice experiment was undertaken to test consistency with the principles of QALY maximization and to quantify the willingness to trade life-year gains for distributive justice. An empirical ethics process was used to identify attributes that appeared relevant and ethically justified: patient age, severity (decomposed into initial quality and life expectancy), final health state, duration of benefit, and distributional concerns. Only 3% of respondents maximized QALYs with every choice, but scenarios with larger aggregate QALY gains were chosen more often and a majority of respondents maximized QALYs in a majority of their choices. However, respondents also appeared willing to prioritize smaller gains to preferred groups over larger gains to less preferred groups. Marginal analyses found a statistically significant preference for younger patients and a wider distribution of gains, as well as an aversion to patients with the shortest life expectancy or a poor final health state. These results support the existence of an equity-efficiency tradeoff and suggest that well-being could be enhanced by giving priority to programs that best satisfy societal preferences. Societal preferences could be incorporated through the use of explicit equity weights, although more research is required before such weights can be used in priority setting.

  11. 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. PMID:26994555

  12. 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

  13. 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.

  14. Molecular size and molecular size distribution affecting traditional balsamic vinegar aging.

    PubMed

    Falcone, Pasquale Massimiliano; Giudici, Paolo

    2008-08-27

    A first attempt at a semiquantitative study of molecular weight (MW) and molecular weight distribution (MWD) in cooked grape must and traditional balsamic vinegar (TBV) with increasing well-defined age was performed by high-performance liquid size exclusion chromatography (SEC) using dual detection, that is, differential refractive index (DRI) and absorbance (UV-vis) based detectors. With this aim, MW and MWD, including number- and weight-average MW and polydispersity, were determined with respect to a secondary standard and then analyzed. All investigated vinegar samples were recognized as compositionally and structurally heterogeneous blends of copolymers (melanoidins) spreading over a wide range of molecular sizes: the relative MW ranged from 2 to >2000 kDa. The extent of the polymerization reactions was in agreement with the TBV browning kinetics. MWD parameters varied asymptotically toward either upper or lower limits during aging, reflecting a nonequilibrium status of the balance between polymerization and depolymerization reactions in TBV. MWD parameters were proposed as potential aging markers of TBV. PMID:18656930

  15. 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.

  16. Analysis of phytoplankton distribution and community structure in the German Bight with respect to the different size classes

    NASA Astrophysics Data System (ADS)

    Wollschläger, Jochen; Wiltshire, Karen Helen; Petersen, Wilhelm; Metfies, Katja

    2015-05-01

    Investigation of phytoplankton biodiversity, ecology, and biogeography is crucial for understanding marine ecosystems. Research is often carried out on the basis of microscopic observations, but due to the limitations of this approach regarding detection and identification of picophytoplankton (0.2-2 μm) and nanophytoplankton (2-20 μm), these investigations are mainly focused on the microphytoplankton (20-200 μm). In the last decades, various methods based on optical and molecular biological approaches have evolved which enable a more rapid and convenient analysis of phytoplankton samples and a more detailed assessment of small phytoplankton. In this study, a selection of these methods (in situ fluorescence, flow cytometry, genetic fingerprinting, and DNA microarray) was placed in complement to light microscopy and HPLC-based pigment analysis to investigate both biomass distribution and community structure of phytoplankton. As far as possible, the size classes were analyzed separately. Investigations were carried out on six cruises in the German Bight in 2010 and 2011 to analyze both spatial and seasonal variability. Microphytoplankton was identified as the major contributor to biomass in all seasons, followed by the nanophytoplankton. Generally, biomass distribution was patchy, but the overall contribution of small phytoplankton was higher in offshore areas and also in areas exhibiting higher turbidity. Regarding temporal development of the community, differences between the small phytoplankton community and the microphytoplankton were found. The latter exhibited a seasonal pattern regarding number of taxa present, alpha- and beta-diversity, and community structure, while for the nano- and especially the picophytoplankton, a general shift in the community between both years was observable without seasonality. Although the reason for this shift remains unclear, the results imply a different response of large and small phytoplankton to environmental influences.

  17. 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...

  18. Occurrence and distribution of conventional and new classes of per- and polyfluoroalkyl substances (PFASs) in the South China Sea.

    PubMed

    Kwok, Karen Y; Wang, Xin-Hong; Ya, Miaolei; Li, Yongyu; Zhang, Xiao-Hua; Yamashita, Nobuyoshi; Lam, James C W; Lam, Paul K S

    2015-03-21

    Concentrations of 23 per- and polyfluoroalkyl substances (PFASs), including new classes of PFASs, in seawater samples were investigated for their occurrence and the interaction of the ocean currents with the distribution of PFASs in the South China Sea. This study revealed that socio-economic development was associated with the PFAS contamination in coastal regions of South China. Significant correlations between concentration of total PFASs with gross domestic product (GDP) per capita and population density were found in the areas, suggesting that the influence of intense human activities in these areas may have resulted in higher PFAS contamination to the adjacent environment. Di-substituted polyfluoroalkyl phosphate (diPAP), one of the potential replacements for PFASs, was only detected in the heavily developed region, namely Pearl River Delta (PRD). Total PFAS concentrations, ranging from 195 to 4925 pg/L, were detected at 51 sampling stations of the South China Sea. The results also confirmed that PFAS contamination in the South China Sea is strongly affected by the ocean currents. In comparison to perfluoroactane sulfonate (PFOS) concentrations measured nine years ago at the same locations, the concentrations in this study were found to be two times higher. This indicated that the use and production of perfluoroalkyl sulfonates (PFSAs) has been continuing in the region. PMID:25528239

  19. Occurrence and distribution of conventional and new classes of per- and polyfluoroalkyl substances (PFASs) in the South China Sea.

    PubMed

    Kwok, Karen Y; Wang, Xin-Hong; Ya, Miaolei; Li, Yongyu; Zhang, Xiao-Hua; Yamashita, Nobuyoshi; Lam, James C W; Lam, Paul K S

    2015-03-21

    Concentrations of 23 per- and polyfluoroalkyl substances (PFASs), including new classes of PFASs, in seawater samples were investigated for their occurrence and the interaction of the ocean currents with the distribution of PFASs in the South China Sea. This study revealed that socio-economic development was associated with the PFAS contamination in coastal regions of South China. Significant correlations between concentration of total PFASs with gross domestic product (GDP) per capita and population density were found in the areas, suggesting that the influence of intense human activities in these areas may have resulted in higher PFAS contamination to the adjacent environment. Di-substituted polyfluoroalkyl phosphate (diPAP), one of the potential replacements for PFASs, was only detected in the heavily developed region, namely Pearl River Delta (PRD). Total PFAS concentrations, ranging from 195 to 4925 pg/L, were detected at 51 sampling stations of the South China Sea. The results also confirmed that PFAS contamination in the South China Sea is strongly affected by the ocean currents. In comparison to perfluoroactane sulfonate (PFOS) concentrations measured nine years ago at the same locations, the concentrations in this study were found to be two times higher. This indicated that the use and production of perfluoroalkyl sulfonates (PFSAs) has been continuing in the region.

  20. Role of body fat distribution in the decline in insulin sensitivity and glucose tolerance with age.

    PubMed

    Coon, P J; Rogus, E M; Drinkwater, D; Muller, D C; Goldberg, A P

    1992-10-01

    The relationships of body composition and physical fitness [maximal aerobic capacity (VO2max)] to the decline in insulin sensitivity with age were examined in healthy older (47-73 yr; n = 36) and young (19-36 yr; n = 13) men. In 18 older men with normal glucose tolerance (OGTT), glucose disposal rates (M) during hyperinsulinemic euglycemic clamps correlated negatively with the waist to hip ratio (WHR; r = -0.77; P < .001) and percent body fat (r = -0.46; P < 0.05) and positively with VO2max (r = 0.54; P < 0.05), but not with age. Similar relationships existed in the 36 older men with a spectrum of OGTT responses; however, only WHR was independently related to M (r2 = 0.32; P < 0.01). In the older men with normal OGTT, M (mean +/- SEM, 7.88 +/- 0.43 mg/kg fat-free mass.min) was not different from that in the young men (8.56 +/- 0.47; P = NS). Furthermore, in older and young men with normal OGTT matched for WHR, percent fat, or VO2max, glucose disposal was comparable at sequential 15-min intervals during the clamp and in its relationship to insulin concentrations at the tissue level (multicompartmental analysis). In contrast, despite higher steady state plasma insulin levels during the clamp, M was significantly lower in the older men with a higher WHR, greater percent fat, lower VO2max, or impaired OGTT. Thus, in healthy older men up to the age of 73 yr, insulin sensitivity and glucose tolerance are affected primarily by the regional body fat distribution, not age, obesity, or VO2max.

  1. Linking chemostatic behaviour of streams to storage dynamics and long tails in water age distributions

    NASA Astrophysics Data System (ADS)

    Hrachowitz, Markus; Savenije, Hubert; Soulsby, Chris; Tetzlaff, Doerthe

    2013-04-01

    The water storage and release dynamics at the catchment scale are still incompletely understood. This is in particular true when considering actual particle transport rather than only the hydraulic response. Environmental tracers are frequently instrumental in inferring transport process dynamics. Several recent research papers for example highlight the importance of difference time scales in transport dynamics. While on the short term, particle transport patterns can exhibit considerable variability, many catchments are characterized by near-chemostatic behaviour on the long term. In other words although the tracer response can show considerable fluctuations on the intra-annual scale, it remains surprisingly stable at the inter-annual scale. This suggests (1) that at the long term the composition of water can be largely independent of flow volumes and (2) that water as well as tracers/contaminants, once stored in a catchment can remain in the system for a very long time. Here we use long term (< 20 years) precipitation, flow and tracer (chloride) data of three contrasting upland catchments in the Scottish Highlands to inform integrated conceptual models investigating different mixing assumptions. Using the models as diagnostic tools in a functional comparison, water and tracer fluxes were then tracked with the objective of exploring the origin and pattern of near-chemostatic behaviour which manifests itself in long, power-law tails of water age distributions. The results highlight the potential importance of partial mixing processes in the generation of long tails in water age distributions. However, the degree to which partial mixing influences the generation of long tails is dependent on the hydrological functioning of a catchment. As second influential factor controlling the tailing behaviour of water age distributions was identified to be the interplay of flow path connectivity with the relative importance and timing of different flow paths. This understanding

  2. Vertical distribution of ozone and nitrogenous pollutants in an air quality class I area, the San Gorgonio wilderness, southern California.

    PubMed

    Alonso, Rocío; Bytnerowicz, Andrzej; Arbaugh, Michael

    2002-01-01

    Information about spatial and temporal distribution of air pollutants is essential for better understanding of environmental stresses affecting forests and estimation of potential risks associated with air pollutants. Ozone and nitrogenous air pollutants were monitored along an elevation gradient in the Class I San Gorgonio Wilderness area (San Bernardino Mountains, California, U.S.) during the summer of 2000 (mid-June to mid-October). Passive samplers were exposed for 2-week periods at six sampling sites located at 300 m intervals ranging from 1200 to 2700 m elevation. Elevated concentrations of ozone were found in this area with summer 24-h hourly means ranging from 53 to 59 ppb. The highest ozone concentrations were detected in the period July 25-August 8, reaching values of 64 to 72 ppb expressed as 2-week mean. Passive-sampler ozone data did not show a clear relationship with elevation, although during the periods with higher ozone levels, ozone concentrations were higher at those sites below 2000 m than at sites located above that elevation. All nitrogenous pollutants studied showed a consistent decrease of concentrations with elevation. Nitrogen dioxide (NO2) levels were low, decreasing with increasing elevation from 6.4 to 1.5 ppb summer means. Nitric oxide (NO) concentrations were around 1 to 2 ppb, which is within the range of the detection levels of the devices used. Nitric acid (HNO3) vapor concentrations were lower at higher elevations (summer means 1.9-2.5 microg m(-3) than at lower elevations (summer means 4.3-5.1 microg m(-3). Summer concentrations of ammonia (NH3) were slightly higher than nitric acid ranging from 6 microg m(-3) at the lowest site to 2.5 microg m(-3) registered at the highest elevation. Since complex interactions between ozone and nitrogenous air pollutants have already been described for forests, simultaneous information about the distribution of these pollutants is needed. This is particularly important in mountain terrain where

  3. Prevalence, Type, Distribution, and Severity of Cerebral Palsy in Relation to Gestational Age: A Meta-Analytic Review

    ERIC Educational Resources Information Center

    Himpens, E.; Van den Broeck, C.; Oostra, A.; Calders, P.; Vanhaesebrouck, P.

    2008-01-01

    The aim of this review is to determine the relationship between gestational age (GA) and prevalence, type, distribution, and severity of cerebral palsy (CP). Epidemiological studies with cohorts expressed by GA were assessed. A comprehensive meta-analysis and meta-regression was performed on four fetal age categories. Studies of children with CP…

  4. [Health Care Insurance in France: its impact on income distribution between age and social groups].

    PubMed

    Fourcade, N; Duval, J; Lardellier, R

    2013-08-01

    Our study, based on microsimulation models, evaluates the redistributive impact of health care insurance in France on income distribution between age and social groups. This work sheds light on the debate concerning the respective role of the public health care insurance (PHI) and the private supplemental health care insurance (SHI) in France. The analysis points out that the PHI enables the lowest-income households and the pensioners a better access to health care than they would have had under a complete private SHI. Due to the progressivity of taxes, low-income households contribute less to the PHI and get higher benefits because of a weaker health. Pensioners have low contributions to public health care finance but the highest health care expenditures.

  5. Age rationing and the just distribution of health care: is there a duty to die?

    PubMed

    Battin, Margaret Pabst

    1987-01-01

    The author analyzes the argument that a policy involving distributive justice in the allocation of scarce health care resources, based on the strategy of rational self interest maximation under a veil of ignorance (Rawls/Daniels), would result in an age rationing system of voluntary, socially encouraged, direct termination of the lives of the elderly rather than their medical abandonment. She maintains that such a policy would be a fair response only in a situation of substantial scarcity of resources that cannot be relieved without introducing greater injustices. Battin suggests that some of the current pressure on resources could be reduced by pruning waste and the expenses attributable to paternalistic imposition of treatment and to the practice of defensive medicine. She also advocates reconsideration of societal priorities assigned to various social goods.

  6. Distribution, geochemistry and age of the Millennium eruptives of Changbaishan volcano, Northeast China -- A review

    NASA Astrophysics Data System (ADS)

    Sun, Chunqing; You, Haitao; Liu, Jiaqi; Li, Xin; Gao, Jinliang; Chen, Shuangshuang

    2014-04-01

    Large explosive volcanic eruptions generate extensive regional tephra deposits that provide favorable conditions for identifying the source of volcanoes, comparing the sedimentary strata of a region and determining their ages. The tephra layer, referred to as BTm, generated by the Millennium eruption of Changbaishan volcano, is widely distributed in Northeast China, Japan, D.P.R. Korea, and the nearby coastal area of Russia. It forms part of the widespread northeast Asian strata and is significant for establishing an isochronal stratigraphic framework. However, research on the temporal characterization and stratigraphic correlation of associated strata using this tephra layer is mainly concentrated in and near Japan. In northeastern China, this tephra layer is seldom seen and its application in stratigraphic correlations is even rarer. More importantly, the determination of accurate ages for both distal and proximal tephras has been debated, leading to controversy in discussions of its environmental impacts. Stratigraphic records from both distal and proximal Changbaishan ash show that this eruption generally occurred between 1,012 and 1,004 cal yr BP. Geochemical comparison between Changbaishan ash and the Quaternary widespread ash around Japan illustrates that Changbaishan ash is a continuous composition from rhyolitic to trachytic and its ratio of FeOT to CaO is usually greater than 4, which can be used as a distinguishing identifier among worldwide contemporary eruptions.

  7. Distribution, geochemistry and age of the Millennium eruptives of Changbaishan volcano, Northeast China — A review

    NASA Astrophysics Data System (ADS)

    Sun, Chunqing; You, Haitao; Liu, Jiaqi; Li, Xin; Gao, Jinliang; Chen, Shuangshuang

    2014-06-01

    Large explosive volcanic eruptions generate extensive regional tephra deposits that provide favorable conditions for identifying the source of volcanoes, comparing the sedimentary strata of a region and determining their ages. The tephra layer, referred to as B-Tm, generated by the Millennium eruption of Changbaishan volcano, is widely distributed in Northeast China, Japan, D.P.R. Korea, and the nearby coastal area of Russia. It forms part of the widespread northeast Asian strata and is significant for establishing an isochronal stratigraphic framework. However, research on the temporal characterization and stratigraphic correlation of associated strata using this tephra layer is mainly concentrated in and near Japan. In northeastern China, this tephra layer is seldom seen and its application in stratigraphic correlations is even rarer. More importantly, the determination of accurate ages for both distal and proximal tephras has been debated, leading to controversy in discussions of its environmental impacts. Stratigraphic records from both distal and proximal Changbaishan ash show that this eruption generally occurred between 1,012 and 1,004 cal yr BP. Geochemical comparison between Changbaishan ash and the Quaternary widespread ash around Japan illustrates that Changbaishan ash is a continuous composition from rhyolitic to trachytic and its ratio of FeOT to CaO is usually greater than 4, which can be used as a distinguishing identifier among worldwide contemporary eruptions.

  8. Educating Other People's Children: Race, Class, Ethnicity, Aging, and the Politics of School Funding in Long Island, New York.

    ERIC Educational Resources Information Center

    Singer, Alan

    Long Island, New York, including Nassau and Suffolk Counties, is a patchwork of small ethnically, racially, and economically segregated towns organized into 126 school districts. School funding patterns and problems conform to racial, ethnic, and class lines. Predominantly minority school districts generally have higher property tax rates, fewer…

  9. The Relation of Age and Social Class Factors in Children's Social Pretend Play to Cognitive and Symbolic Ability.

    ERIC Educational Resources Information Center

    Doyle, Anna-Beth; And Others

    1991-01-01

    The amount of social pretend play in free-play sessions of small groups of five to seven year olds, and the symbolic features of this play, were noted. Conservation, verbal symbol substitution, and role-playing skills, were assessed as measures of cognitive symbolic skill. Results provide no evidence that these social class differences reflect…

  10. 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. PMID:15003584

  11. Impact of the Hapagea surpercontinental aggregation on American Cordilleras and the seafloor age distribution

    NASA Astrophysics Data System (ADS)

    Husson, L.; Conrad, C. P.

    2009-12-01

    The ongoing aggregation of Africa, Arabia, India and Australia onto Eurasia is forming a supercontinent that we refer to as Hapagea. Although not as large as the older Pangea and Rodinia, Hapageais nevertheless large enough to profoundly modify Cenozoic plate kinematics as it gradually becomes a hub apart from which American continents spread. The continuation of Atlantic spreading is carried out at the expense of the Pacific Ocean, forcing the Farallon / Nazca plates down into eastern Pacific subduction zones, despite the fact that this seafloor is theoretically too young and too buoyant to subduct efficiently. This process occurred later for South America, where the subduction of the Tethys buffered the impact of the Atlantic expansion, and earlier for North America where this configuration was never met. The implications of the current plate tectonics are multiple and include (i) increased compression on the western coasts of the Americas, leading to Cordillera formation in North America (Sevier and Laramide) and later in South America (Andean), (ii) the transition from a rectangular distribution of seafloor ages to a triangular distribution as westward progress of the Americas engulfs young Farallon/Nazca seafloor, and (iii) a decrease in the convective efficiency of mantle flow that results in decreased rates of lithospheric productionat ridges, a situation that is cyclically met during the Wilson cycle and diminishes both mantle heat flow and sea level. These results imply that mantle drag causes the Atlantic spread and dominates the force balance of the Earth’s lithospheric shell.

  12. Age distributions and dynamically changing hydrologic systems: Exploring topography-driven flow

    NASA Astrophysics Data System (ADS)

    Gomez, J. D.; Wilson, J. L.

    2013-03-01

    Natural systems are driven by dynamic forcings that change in time as well as space, behavior that is inherited by the system flow field and results in time-varying age distributions (ADs). This work presents a review of the mathematical tools and solution approaches used to model ADs in dynamic time-varying flow systems. A simple conceptual, numerical model is then used to explore the role of flow dynamics in ADs for topography-driven flow systems. This model is an analog for regional groundwater systems and hyporheic zones. This model demonstrates that relatively small fluctuations in the forcing, even though importantly affecting the flow in the system, can have minimal effects in ADs. However, as the intensity of fluctuation increases, still within the bounds observed in natural systems, ADs in shallow parts of the system become highly sensitive to dynamic flow conditions, leading to considerable changes in the moments and modality of the distributions with time. In particular, transient flow can lead to emergence of new modes in the AD, which would not be present under steady flow conditions. The discrepancy observed between ADs under steady and transient flow conditions is explained by enhancement of mixing due to temporal variations in the flow field. ADs in deeper parts of the system are characterized by multimodality and tend to be more stable over time even for large forcing fluctuations.

  13. The effect of a senior jazz dance class on static balance in healthy women over 50 years of age: a pilot study.

    PubMed

    Wallmann, Harvey W; Gillis, Carrie B; Alpert, Patricia T; Miller, Sally K

    2009-01-01

    The purpose of this pilot study is to assess the impact of a senior jazz dance class on static balance for healthy women over 50 years of age using the NeuroCom Smart Balance Master System (Balance Master). A total of 12 healthy women aged 54-88 years completed a 15-week jazz dance class which they attended 1 time per week for 90 min per class. Balance data were collected using the Sensory Organization Test (SOT) at baseline (pre), at 7 weeks (mid), and after 15 weeks (post). An equilibrium score measuring postural sway was calculated for each of six different conditions. The composite equilibrium score (all six conditions integrated to 1 score) was used as an overall measure of balance. Repeated measures analyses of variance (ANOVAs) were used to compare the means of each participant's SOT composite equilibrium score in addition to the equilibrium score for each individual condition (1-6) across the 3 time points (pre, mid, post). There was a statistically significant difference among the means, p < .0005. Pairwise (Bonferroni) post hoc analyses revealed the following statistically significant findings for SOT composite equilibrium scores for the pre (67.33 + 10.43), mid (75.25 + 6.97), and post (79.00 + 4.97) measurements: premid (p = .008); prepost (p < .0005); midpost (p = .033). In addition, correlational statistics were used to determine any relationship between SOT scores and age. Results indicated that administration of a 15-week jazz dance class 1 time per week was beneficial in improving static balance as measured by the Balance Master SOT.

  14. 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

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

    DOE PAGES

    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.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

  16. 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

  17. Effects of United States Department of Agriculture carcass maturity on sensory attributes of steaks produced by cattle representing two dental age classes.

    PubMed

    Semler, M L; Woerner, D R; Belk, K E; Enns, K J; Tatum, J D

    2016-05-01

    This study examined the effects of USDA carcass maturity on sensory properties of LM steaks produced by cattle representing 2 dental age classes. Carcasses identified for use in the experiment were produced by steers and heifers classified as either <30 mo of age (MOA) or ≥30 MOA at the time of slaughter using dentition. Within each dental age class, carcasses were selected to represent 2 maturity groups and 3 marbling categories, resulting in 12 dental age × maturity × marbling subclasses, each consisting of 50 carcasses. Maturity groups consisted of carcasses classified by USDA graders as either A to A (A) overall maturity or B to D (B-D) overall maturity; marbling categories consisted of carcasses with instrument marbling scores of Slight to Slight (SL), Small to Small (SM), or Modest to Moderate (MT-MD). Carcasses were selected in pairs so that each carcass chosen to represent the B-D-maturity group was paired with an A-maturity carcass of the same sex and marbling score (±50 marbling units). Strip loin (LM) steaks were obtained from both sides of each carcass. After a 14-d aging period, 1 LM steak was measured for Warner-Bratzler shear force (WBSF) and slice shear force (SSF), whereas the other LM steak was used for sensory analysis by a trained descriptive attribute panel. No differences ( > 0.05) in LM tenderness, juiciness, or flavor were detected between carcass maturity groups in either dental age class. Advanced dental age (≥30 MOA), however, was associated with more intense ( < 0.05) grassy and bloody/serumy flavors and decreased ( < 0.05) tenderness within the SL marbling group. Marbling score effectively stratified carcasses (MT-MD > SM > SL) according to differences ( < 0.0001) in LM tenderness, juiciness, beefy/brothy flavor, and buttery/beef fat flavor. In addition, increased marbling was associated with lesser ( < 0.01) intensities of bloody/serumy, livery/organy, and grassy flavors as well as smaller ( < 0.0001) values for WBSF and SSF

  18. 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

  19. NewAge: a semi-distributed hydrological model as a dynamical system, and something more.

    NASA Astrophysics Data System (ADS)

    Rigon, Riccardo; Franceschi, Silvia; Antonello, Andrea; Endrizzi, Stefano; Formetta, Giuseppe

    2010-05-01

    We describe and analyse the performances of the semi-distributed hydrological model NewAGE. This model itself is made-up of five main parts: the radiation budget estimation, the snow modelling, the evapotranspiration part, the hillslope runoff budget and the runoff aggregation in the river network, and finally the flood propagation. The model concept is based on the idea the elementary units are the hillslopes for each one the model gives the estimates of the prognostic simulated variables (one estimate for variable). Each "hillslope" does not need to coincide to the real hillslope, and can actually cover a small basin, up to some square kilometres. It constitutes the elementary "grid" element of the model. Each "hillslope" is connected to the others by the channel network. In turn, this is represented by an oriented graph, whose links are numbered through a generalisation of the Pfafstetter ordering. The topological partition of the basin is performed by a proper set of tools in JGrass. The mass budget for each hillslope is performed according to a suitable modification of Duffy (1996) dynamical model of hillslope runoff. Discharge in each link of the river network is evaluated according to Cuencas (2005). Radiation is calculated accounting for the sub-hillslope-variability in accord to a suitable scheme described in this contribution. Evapotranspiration estimation uses the Penman-Monteith formula, and includes hillslope variability in land use, soil cover and hydrological state. Flood wave propagation for the main streams can be estimated with a solver of the 1D de Saint Venant equation. Snow is modelled by a custom implementation of the Utah Energy Balance concepts. This model can simulate all the parts of the hydrological cycle, but besides being also a model of the physical processes, it also implements the infrastructure dealing with human works and reservoirs. These modelling parts are supported by appropriate ancillary modules for the treatment of the

  20. 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

  1. Socio-occupational class, region of birth and maternal age: influence on time to detection of cryptorchidism (undescended testes): a Danish nationwide register study

    PubMed Central

    2014-01-01

    Background Cryptorchidism (undescended testes) is associated with poor male fertility, but can be alleviated and fertility preserved to some degree by early detection and treatment. Here we assess the influence of socio-occupational class, geographical region, maternal age and birth cohort on time to detection and correction of cryptorchidism. Methods All boys born in Denmark, 1981 to 1987 or 1988 to 1994, with a diagnosis of cryptorchidism were identified in nationwide registers. The boys were followed for a diagnosis until their 16th birthday. The age at first diagnosis was noted and used as proxy for time to detection of cryptorchidism. Parental employment in the calendar year preceding birth was grouped into one of five socio-occupational classes. Geographical region was defined by place of birth in one of 15 Danish counties. Detection rate ratios of cryptorchidism were analyzed as a function of parental socio-occupational group, county, maternal age and birth cohort by use of Poisson regression. Results Some 6,059 boys in the early and 5,947 boys in the late cohort received a diagnosis of cryptorchidism. Time to detection was independent of parental socio-occupational group and maternal age but differed slightly between geographical regions. A similar pattern was obtained for surgical correction after a diagnosis. Age at diagnosis decreased by 2.7 years from the early to the late cohort. Conclusions These results indicate that childhood socio-occupational inequality in detection and correction of cryptorchidism would play a negligible role in male infertility in a life course perspective. Geographical region may have exerted some influence, especially for the oldest cohort. PMID:24581337

  2. The Left Hand Second to Fourth Digit Ratio (2D:4D) Does Not Discriminate World-Class Female Gymnasts from Age Matched Sedentary Girls

    PubMed Central

    Peeters, Maarten W.; Claessens, Albrecht L.

    2012-01-01

    Introduction The second to fourth-digit-ratio (2D:4D), a putative marker of prenatal androgen action and a sexually dimorphic trait, has been suggested to be related with sports performance, although results are not univocal. If this relation exists, it is most likely to be detected by comparing extreme groups on the continuum of sports performance. Methods In this study the 2D:4D ratio of world-class elite female artistic gymnasts (n = 129), competing at the 1987 Rotterdam World-Championships was compared to the 2D:4D ratio of sedentary age-matched sedentary girls (n = 129), alongside with other anthropometric characteristics including other sexually dimorphic traits such as an androgyny index (Bayer & Bayley) and Heath-Carter somatotype components (endomorphy, mesomorphy, ectomorphy) using AN(C)OVA. 2D:4D was measured on X-rays of the left hand. Results Left hand 2D:4D digit ratio in world class elite female gymnasts (0.921±0.020) did not differ significantly from 2D:4D in age-matched sedentary girls (0.924±0.018), either with or without inclusion of potentially confounding covariates such as skeletal age, height, weight, somatotype components or androgyny index. Height (161.9±6.4 cm vs 155.4±6.6 cm p<0.01), weight (53.9±7.6 kg vs 46.2 6.3 kg p<0.01), BMI (20.51±2.41 kg/m2 vs 19.05±1.56 kg/m2), skeletal age (15.2±1.1 y vs 14.5±1.2 y p>0.01), somatotype components (4.0/3.0/2.9 vs 1.7/3.7/3.2 for endomorphy (p<0.01), mesomorphy (p<0.01) and ectomorphy (p<0.05) respectively) all differed significantly between sedentary girls and elite gymnasts. As expressed by the androgyny index, gymnasts have, on average, broader shoulders relative to their hips, compared to the reference sample. Correlations between the 2D:4D ratio and chronological age, skeletal age, and the anthropometric characteristics are low and not significant. Conclusion Although other anthropometric characteristics of sexual dimorphism were significantly different between the two samples

  3. Occupational class inequalities in all-cause and cause-specific mortality among middle-aged men in 14 European populations during the early 2000s.

    PubMed

    Toch-Marquardt, Marlen; Menvielle, Gwenn; Eikemo, Terje A; Kulhánová, Ivana; Kulik, Margarete C; Bopp, Matthias; Esnaola, Santiago; Jasilionis, Domantas; Mäki, Netta; Martikainen, Pekka; Regidor, Enrique; Lundberg, Olle; Mackenbach, Johan P

    2014-01-01

    This study analyses occupational class inequalities in all-cause mortality and four specific causes of death among men, in Europe in the early 2000s, and is the most extensive comparative analysis of occupational class inequalities in mortality in Europe so far. Longitudinal data, obtained from population censuses and mortality registries in 14 European populations, from around the period 2000-2005, were used. Analyses concerned men aged 30-59 years and included all-cause mortality and mortality from all cancers, all cardiovascular diseases (CVD), all external, and all other causes. Occupational class was analysed according to five categories: upper and lower non-manual workers, skilled and unskilled manual workers, and farmers and self-employed combined. Inequalities were quantified with mortality rate ratios, rate differences, and population attributable fractions (PAF). Relative and absolute inequalities in all-cause mortality were more pronounced in Finland, Denmark, France, and Lithuania than in other populations, and the same countries (except France) also had the highest PAF values for all-cause mortality. The main contributing causes to these larger inequalities differed strongly between countries (e.g., cancer in France, all other causes in Denmark). Relative and absolute inequalities in CVD mortality were markedly lower in Southern European populations. We conclude that relative and absolute occupational class differences in all-cause and cause specific mortality have persisted into the early 2000's, although the magnitude differs strongly between populations. Comparisons with previous studies suggest that the relative gap in mortality between occupational classes has further widened in some Northern and Western European populations.

  4. Occupational Class Inequalities in All-Cause and Cause-Specific Mortality among Middle-Aged Men in 14 European Populations during the Early 2000s

    PubMed Central

    Toch-Marquardt, Marlen; Menvielle, Gwenn; Eikemo, Terje A.; Kulhánová, Ivana; Kulik, Margarete C.; Bopp, Matthias; Esnaola, Santiago; Jasilionis, Domantas; Mäki, Netta; Martikainen, Pekka; Regidor, Enrique; Lundberg, Olle; Mackenbach, Johan P.

    2014-01-01

    This study analyses occupational class inequalities in all-cause mortality and four specific causes of death among men, in Europe in the early 2000s, and is the most extensive comparative analysis of occupational class inequalities in mortality in Europe so far. Longitudinal data, obtained from population censuses and mortality registries in 14 European populations, from around the period 2000–2005, were used. Analyses concerned men aged 30–59 years and included all-cause mortality and mortality from all cancers, all cardiovascular diseases (CVD), all external, and all other causes. Occupational class was analysed according to five categories: upper and lower non-manual workers, skilled and unskilled manual workers, and farmers and self-employed combined. Inequalities were quantified with mortality rate ratios, rate differences, and population attributable fractions (PAF). Relative and absolute inequalities in all-cause mortality were more pronounced in Finland, Denmark, France, and Lithuania than in other populations, and the same countries (except France) also had the highest PAF values for all-cause mortality. The main contributing causes to these larger inequalities differed strongly between countries (e.g., cancer in France, all other causes in Denmark). Relative and absolute inequalities in CVD mortality were markedly lower in Southern European populations. We conclude that relative and absolute occupational class differences in all-cause and cause specific mortality have persisted into the early 2000's, although the magnitude differs strongly between populations. Comparisons with previous studies suggest that the relative gap in mortality between occupational classes has further widened in some Northern and Western European populations. PMID:25268702

  5. 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.

  6. Recent changes in earnings distributions in the United States: age and cohort effects.

    PubMed

    Utendorf, K R

    1999-01-01

    In this article, the author uses large, Social Security administrative data sets to examine changes in earnings distributions in the United States over the 1980s through the mid-1990s. Because the earnings information contained in these data sets comes directly from the W-2 forms field by employers, self-reporting errors and top-coding problems, common in other data used for this type of analysis, are minimized. Previous research has documented an increase in overall earnings inequality during the 1970s and the 1980s. The author finds that this upward trend in overall earnings inequality continues into the mid-1990s, despite a period of nearly constant or slightly decreasing earnings inequality from 1988 through 1992. The data also suggest that between-group earnings inequality, whether dividing the sample into groups by age group or by birth cohort, is increasing. Despite the increase in between-group earnings inequality over the period examined, however, within-group earnings inequality remains by far the largest contributor to overall earnings inequality.

  7. The Evolution of an Undergraduate Service Course--How To Cope with Success of an Age of Dinosaurs Class.

    ERIC Educational Resources Information Center

    Montgomery, Homer

    2003-01-01

    Discusses how to address the issue of a course becoming too popular. Uses as an example the Age of Dinosaurs course at the University of Texas at Dallas. Describes some issues that can arise such as classroom overflow, overwhelmed labs, cheating, testing methods, and asynchronous instruction. Recommends looking to web-based course management…

  8. Academic Success as a Function of the Gender, Class, Age, Study Habits, and Employment of College Students.

    ERIC Educational Resources Information Center

    Lammers, William J.; Onwuegbuzie, Anthony J.; Slate, John R.

    2001-01-01

    Studied the predominant study skills and weaknesses of college students in a sample of 366 undergraduates. Study skill weaknesses were identified in the areas of note-taking, reading skills, and time management. Study skills were also related to age, grade point average, and the number of hours spent studying each week. (SLD)

  9. Chemical structure of cement aged at normal and elevated temperatures and pressures, Part II: Low permeability class G oilwell cement

    SciTech Connect

    Le Saout, Gwenn . E-mail: gwenn.lesaout@epfl.ch; Lecolier, Eric; Rivereau, Alain; Zanni, Helene

    2006-03-15

    Recently, Low Permeability Cement formulation has been developed for oilwell cementing. Therefore, it is important to understand the physical and chemical processes causing cement degradation in the downhole environment. In this study, we have characterised a Low Permeability Class G oilwell Cement immersed for one year in brine at T = 293 K, p = 10{sup 5} Pa and T = 353 K, p = 7 x 10{sup 6} Pa using {sup 29}Si, {sup 27}Al NMR and XRD techniques. Elevated temperature and pressure conditions increase the rate of the pozzolanic reaction and have significant effects on the polymerisation of C-S-H and on the incorporation of Al in the C-S-H structure. Leaching resulted in the formation of calcite and a more polymerised C-S-H with the appearance of tobermorite in the sample cured at elevated temperature and pressure.

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

    PubMed

    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

  12. Qualitative characteristics of meat from cull cows of different genotypes and age class slaughter under different finishing systems: a meta-analytic approach.

    PubMed

    Pacheco, Rangel F; Mayer, Andrei R; Vaz, Marcos A B; Pötter, Luciana; Cattelam, Jonatas; Callegaro, Álisson M; Pizzuti, Luiz Angelo D; Brondani, Ivan L; Alves Filho, Dari C; Pacheco, Paulo S

    2015-01-01

    The aim of this study was to evaluate, by meta-analysis, the quality of the meat of the cows according to genotype, termination system and age class slaughter. During an online research were identified 15 articles with information related to meat quality of slaughtered cows. The data were grouped according of the genotype of cows being: zebu or continental defined, crossed zebu x british or zebu x continental; according to termination system: feedlot or grassland; according to age of slaughter, where: up to 4 years old (young), 4-8 years old (adult) or more than 8 years old (old). The meat of the continental crossbred cows was softer than the other genotypes, both panel of evaluators and by Shear. The meat of cows finished in feedlot showed higher marbling degree in relation to meat of females finished on grassland. The reduction of the slaughter age of cows improved the meat color. The cow's genotype affects the organoleptic aspects of meat while the finished system and slaughter age affects the sensory aspects of meat.

  13. PCR/oligonucleotide probe typing of HLA class II alleles in a Filipino population reveals an unusual distribution of HLA haplotypes

    SciTech Connect

    Bugawan, T.L.; Chang, J.D.; Erlich, H.A. ); Klitz, W. )

    1994-02-01

    The authors have analyzed the distribution of HLA class II alleles and haplotypes in a Filipino population by PCR amplification of the DRB1, DQB1, and DPB1 second-exon sequences from buccal swabs obtained from 124 family members and 53 unrelated individuals. The amplified DNA was typed by using nonradioactive sequence-specific oligonucleotide probes. Twenty-two different DRB1 alleles, including the novel Filipino *1105, and 46 different DRB1/DQB1 haplotypes, including the unusual DRB1*0405-DQB1*0503, were identified. An unusually high frequency (f = .383) of DPB1*0101, a rare allele in other Asian populations, was also observed. In addition, an unusual distribution of DRB1 alleles and haplotypes was seen in this population, with DR2 (f = .415) and DRB1*1502-DQB1*0502 (f = .233) present at high frequencies. This distribution of DRB1 alleles differs from the typical HLA population distribution, in which the allele frequencies are more evenly balanced. The distribution of HLA class II alleles and haplotypes in this Filipino population is different from that of other Asian and Pacific groups: of those populations studied to date, the Indonesian population is the most similar. DRB1*1502-DQB1*0502 was in strong linkage disequilibrium (D[prime] = .41) with DPB 1*0101 (f = .126, for the extended haplotype), which is consistent with selection for this DR, DQ, DP haplotype being responsible for the high frequency of these three class II alleles in this populations. 30 refs., 2 figs., 6 tabs.

  14. 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.

  15. How to evaluate an agent's behavior to infrequent events?—Reliable performance estimation insensitive to class distribution

    PubMed Central

    Straube, Sirko; Krell, Mario M.

    2014-01-01

    In everyday life, humans and animals often have to base decisions on infrequent relevant stimuli with respect to frequent irrelevant ones. When research in neuroscience mimics this situation, the effect of this imbalance in stimulus classes on performance evaluation has to be considered. This is most obvious for the often used overall accuracy, because the proportion of correct responses is governed by the more frequent class. This imbalance problem has been widely debated across disciplines and out of the discussed treatments this review focusses on performance estimation. For this, a more universal view is taken: an agent performing a classification task. Commonly used performance measures are characterized when used with imbalanced classes. Metrics like Accuracy, F-Measure, Matthews Correlation Coefficient, and Mutual Information are affected by imbalance, while other metrics do not have this drawback, like AUC, d-prime, Balanced Accuracy, Weighted Accuracy and G-Mean. It is pointed out that one is not restricted to this group of metrics, but the sensitivity to the class ratio has to be kept in mind for a proper choice. Selecting an appropriate metric is critical to avoid drawing misled conclusions. PMID:24782751

  16. "We Haven't Done Enough for White Working-Class Children": Issues of Distributive Justice and Ethnic Identity Politics

    ERIC Educational Resources Information Center

    Keddie, Amanda

    2015-01-01

    This article explores the politically contentious issue of White working-class student under-achievement within one particular school--a large and culturally diverse comprehensive secondary school in the greater London area. The article examines the equity philosophies and identity politics articulated by staff in their understanding of and…

  17. Test series 1: seismic-fragility tests of naturally-aged Class 1E Gould NCX-2250 battery cells

    SciTech Connect

    Bonzon, L. L.; Hente, D. B.; Kukreti, B. M.; Schendel, J. S.; Tulk, J. D.; Janis, W. J.; Black, D A; Paulsen, G. D.; Aucoin, B. D.

    1984-09-01

    The seismic-fragility response of naturally-aged, nuclear station, safety-related batteries is of interest for two reasons: (1) to determine actual failure modes and thresholds; and (2) to determine the validity of using the electrical capacity of individual cells as an indicator of the end-of-life of a battery, given a seismic event. This report covers the first test series of an extensive program using 12-year old, lead-calcium, Gould NCX-2250 cells, from the James A. Fitzpatrick Nuclear Power Station operated by the New York Power Authority. Seismic tests with three cell configurations were performed using a triaxial shake table: single-cell tests, rigidly mounted; multi-cell (three) tests, mounted in a typical battery rack; and single-cell tests specifically aimed towards examining propagation of pre-existing case cracks. In general the test philosophy was to monitor the electrical properties including discharge capacity of cells through a graduated series of g-level step increases until either the shake-table limits were reached or until electrical failure of the cells occurred. Of nine electrically active cells, six failed during seismic testing over a range of imposed g-level loads in excess of a 1-g ZPA. Post-test examination revealed a common failure mode, the cracking at the abnormally brittle, positive lead bus-bar/post interface; further examination showed that the failure zone was extremely coarse grained and extensively corroded. Presently accepted accelerated-aging methods for qualifying batteries, per IEEE Std. 535-1979, are based on plate growth, but these naturally-aged 12-year old cells showed no significant plate growth.

  18. Age-related changes in the distributions of depressive symptom items in the general population: a cross-sectional study using the exponential distribution model.

    PubMed

    Tomitaka, Shinichiro; Kawasaki, Yohei; Ide, Kazuki; Yamada, Hiroshi; Furukawa, Toshiaki A; Ono, Yutaka

    2016-01-01

    Background. Previous research has reported inconsistent evidence of the trajectory of depressive symptoms across the adult lifespan. We investigated how the distributions of each item score change with age and determined whether the trajectory of depressive symptoms varied with the scoring methods of the questionnaire. Methods. We analyzed data collected from 21,040 subjects who participated in the national survey in Japan. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The CES-D has 20 items, each of which is scored in four grades of "rarely," "some," "much," and "most of the time." We used the exponential distribution model which fits the distributions of 16 negative symptom items of CES-D, with the probabilities of "some," "much," "most," and "rarely" expressed as P, Pr, Pr (2), and 1 - P × (r (2) + r + 1). Results. The distributions of the responses to 16 negative symptom items followed the common exponential model across all age groups. The mean of the estimated parameter r of 16 negative items showed a U-shape pattern, being high during 12-29 years, remaining low during 30-50 years, and then increasing again over 60 years. The trajectory of depressive symptom scores simulating the binary method was different from that of the empirical scores using the Likert method. Conclusions. Our findings show that the increase in the depressive symptoms score during older age is based on the increase of the parameter r. The differences in the scoring method may contribute to the different age-related patterns across the adult lifespan. PMID:26788427

  19. Estimating survival of precocial chicks during the prefledging period using a catch-curve analysis and count-based age-class data

    USGS Publications Warehouse

    McGowan, C.P.; Millspaugh, J.J.; Ryan, M.R.; Kruse, C.D.; Pavelka, G.

    2009-01-01

    Estimating reproductive success for birds with precocial young can be difficult because chicks leave nests soon after hatching and individuals or broods can be difficult to track. Researchers often turn to estimating survival during the prefledging period and, though effective, mark-recapture based approaches are not always feasible due to cost, time, and animal welfare concerns. Using a threatened population of Piping Plovers (Charadrius melodus) that breeds along the Missouri River, we present an approach for estimating chick survival during the prefledging period using long-term (1993-2005), count-based, age-class data. We used a modified catch-curve analysis, and data collected during three 5-day sampling periods near the middle of the breeding season. The approach has several ecological and statistical assumptions and our analyses were designed to minimize the probability of violating those assumptions. For example, limiting the sampling periods to only 5 days gave reasonable assurance that population size was stable during the sampling period. Annual daily survival estimates ranged from 0.825 (SD = 0.03) to 0.931 (0.02) depending on year and sampling period, with these estimates assuming constant survival during the prefledging period and no change in the age structure of the population. The average probability of survival to fledging ranged from 0.126 to 0.188. Our results are similar to other published estimates for this species in similar habitats. This method of estimating chick survival may be useful for a variety of precocial bird species when mark-recapture methods are not feasible and only count-based age class data are available. ?? 2009 Association of Field Ornithologists.

  20. Distribution of age-related thymulin titres in normal subjects through the course of life

    PubMed Central

    Consolini, R; Legitimo, A; Calleri, A; Milani, M

    2000-01-01

    The thymus has a dominant immunological role in utero and in early childhood, being a primary source of T lymphopoiesis, and its investigation may be particularly relevant for the immunological study of paediatric patients. Thymulin, a nonapeptide secreted by the thymus, is an essential hormone for T lymphocyte differentiation and function. As thymulin values in the normal population have not been well documented, especially for children under the age of 1 year, we detail thymic endocrine function by presenting age-related plasma thymulin levels in a large series (n = 93) of healthy individuals, ranging from birth to old age. We demonstrate that thymulin is already detectable at birth; it then gradually increases with age, reaching the highest level in children aged 5–10 years. Starting at adolescence, thymulin titres gradually start to fall, reaching the lowest value at 36 years of age and remaining steady until 80 years (the oldest person tested). PMID:10971509

  1. Test Series 2: seismic-fragility tests of naturally-aged Class 1E Exide FHC-19 battery cells

    SciTech Connect

    Bonzon, L. L.; Hente, D. B.; Kukreti, B. M.; Schendel, J.; Tulk, J. D.; Janis, W. J.; Black, D. A.; Paulsen, G. D.; Aucoin, B. D.

    1985-03-01

    The seismic-fragility of naturally-aged nuclear station safety-related batteries is of interest for two reasons: (1) to determine actual failure modes and their thresholds and (2) to determine the validity of using the electrical capacity of individual cells as an indicator of the ''end-of-life'' of a battery if subjected to a seismic event. This report, the second in a test series of an extensive seismic research program, covers the testing of 10-year old lead-calcium Exide FHC-19 cells from the Calvert Cliffs Nuclear Power Station operated by the Baltimore Gas and Electric Company. The Exide cells were tested in two configurations using a triaxial shake table: single-cell tests, both rigidly and loosely mounted; and multicell (three-cell) tests, mounted in a typical battery rack. A total of six electrically active cells was used in the two different cell configurations.

  2. Transport and intracellular distribution of MHC class II molecules and associated invariant chain in normal and antigen-processing mutant cell lines.

    PubMed

    Riberdy, J M; Avva, R R; Geuze, H J; Cresswell, P

    1994-06-01

    We have compared the intracellular transport and subcellular distribution of MHC class II-invariant chain complexes in a wild-type HLA-DR3 homozygous cell line and a mutant cell line, T2.DR3. The latter has a defect in antigen processing and accumulates HLA-DR3 molecules associated with an invariant chain-derived peptide (CLIP) rather than the normal complement of peptides derived from endocytosed proteins. We find that in the wild-type cells, CLIP is transiently associated with HLA-DR3 molecules, suggesting that the peptide is a normal class II-associated intermediate generated during proteolysis of the invariant chain. In the mutant cell line proteolysis of the invariant chain is less efficient, and HLA-DR3/CLIP complexes are generated much more slowly. Examination of the mutant cell line by immunoelectronmicroscopy shows that class II-invariant chain complexes accumulate intracellularly in large acidic vesicles which contain lysosomal markers, including beta-hexosaminidase, cathepsin D, and the lysosomal membrane protein CD63. The markers in these vesicles are identical to those seen in the class II-containing vesicles (MIICs) seen in the wild-type cells but the morphology is drastically different. The vesicles in the mutant cells are endocytic, as measured by the internalization of BSA-gold conjugates. The implication of these findings for antigen processing in general and the nature of the mutation in particular are discussed.

  3. Fractional representation theory - Robustness results with applications to finite dimensional control of a class of linear distributed systems

    NASA Technical Reports Server (NTRS)

    Nett, C. N.; Jacobson, C. A.; Balas, M. J.

    1983-01-01

    This paper reviews and extends the fractional representation theory. In particular, new and powerful robustness results are presented. This new theory is utilized to develop a preliminary design methodology for finite dimensional control of a class of linear evolution equations on a Banach space. The design is for stability in an input-output sense, but particular attention is paid to internal stability as well.

  4. Haplotype distribution in the class I sirtuin genes and their associations with ultrasound carcass traits in Qinchuan cattle (Bos taurus).

    PubMed

    Gui, Linsheng; Hao, Ruijie; Zhang, Yaran; Zhao, Xianlin; Zan, Linsen

    2015-06-01

    Class I sirtuin genes including SIRT1, SIRT2 and SIRT3, are members of the nicotinamide adenine dinucleotide (NAD)-dependent family of histone deacetylases, and play essential roles in senescence, metabolism, and apoptosis. This study was conducted to detect potential polymorphisms of the bovine class I sirtuin genes and explore their relationships with ultrasound carcass traits in Qinchuan cattle. Four non-coding mutations in the 3'UTR (SIRT1: g.25751A > C, SIRT1: g.25846A > G, SIRT2: g.19676G > A and SIRT3: g. 25702C > T) and three mutations in exons (SIRT2: g.4062C > T; SIRT2: g.4406C > T and SIRT3: g.25557A > G) were identified in 468 individuals of Qinchuan cattle. Chi-square tests showed that g.25751A > C, g.19676G > A, and g.25702C > T were in Hardy-Weinberg disequilibrium (χ(2) < χ0.05(2)). The statistical analyses indicated that six SNPs were significantly associated with the ultrasound carcass traits (P < 0.05) except g.4062C > T (SIRT2) (P > 0.05). These results indicate that the variations in the class I sirtuin genes and their corresponding genotypes may be considered as molecular markers for economic traits in cattle breeding.

  5. 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.

  6. The Length Distribution of Class I-Restricted T Cell Epitopes Is Determined by Both Peptide Supply and MHC Allele-Specific Binding Preference.

    PubMed

    Trolle, Thomas; McMurtrey, Curtis P; Sidney, John; Bardet, Wilfried; Osborn, Sean C; Kaever, Thomas; Sette, Alessandro; Hildebrand, William H; Nielsen, Morten; Peters, Bjoern

    2016-02-15

    HLA class I-binding predictions are widely used to identify candidate peptide targets of human CD8(+) T cell responses. Many such approaches focus exclusively on a limited range of peptide lengths, typically 9 aa and sometimes 9-10 aa, despite multiple examples of dominant epitopes of other lengths. In this study, we examined whether epitope predictions can be improved by incorporating the natural length distribution of HLA class I ligands. We found that, although different HLA alleles have diverse length-binding preferences, the length profiles of ligands that are naturally presented by these alleles are much more homogeneous. We hypothesized that this is due to a defined length profile of peptides available for HLA binding in the endoplasmic reticulum. Based on this, we created a model of HLA allele-specific ligand length profiles and demonstrate how this model, in combination with HLA-binding predictions, greatly improves comprehensive identification of CD8(+) T cell epitopes. PMID:26783342

  7. Changes in the mineral density distribution in human bone with age: image analysis using backscattered electrons in the SEM.

    PubMed

    Reid, S A; Boyde, A

    1987-02-01

    We report a study to test the feasibility of studying mineral density distributions in bone using the backscattered electron signal in scanning electron microscopy. Samples were human sixth ribs ranging in age from 8 weeks to 59 years, embedded in polymethylmethacrylate (PMMA), cut, polished, and carbon coated. The proportions of pixels falling in a uniform set of gray level slices of the BSE signal were determined using a microcomputer-based image analysis system interfaced directly to the SEM. The amount of high-density bone gradually increased with age at the expense of low-density bone, and there was an associated compression of the range of the mineral density distribution. Age-related differences were noted between the density distributions in the outer and inner rib cortices. The distribution in the inner cortex in neonates was influenced by the inclusion of densely mineralized endochondral bone and cartilage trabeculae formed at the growth cartilage zone. In adults it appeared that greater bone turnover occurred in the outer cortex, perhaps reflecting a differential mechanical loading across the rib. The technique enabled rapid, unbiased discrimination between the bone of neonates, children, and adults. PMID:3455153

  8. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27029648

  10. 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

    2016-01-01

    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. PMID:27029648

  11. [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

  12. [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

  13. The Indris Have Got Rhythm! Timing and Pitch Variation of a Primate Song Examined between Sexes and Age Classes

    PubMed Central

    Gamba, Marco; Torti, Valeria; Estienne, Vittoria; Randrianarison, Rose M.; Valente, Daria; Rovara, Paolo; Bonadonna, Giovanna; Friard, Olivier; Giacoma, Cristina

    2016-01-01

    A crucial, common feature of speech and music is that they show non-random structures over time. It is an open question which of the other species share rhythmic abilities with humans, but in most cases the lack of knowledge about their behavioral displays prevents further studies. Indris are the only lemurs who sing. They produce loud howling cries that can be heard at several kilometers, in which all members of a group usually sing. We tested whether overlapping and turn-taking during the songs followed a precise pattern by analysing the temporal structure of the individuals' contribution to the song. We found that both dominants (males and females) and non-dominants influenced the onset timing one another. We have found that the dominant male and the dominant female in a group overlapped each other more frequently than they did with the non-dominants. We then focused on the temporal and frequency structure of particular phrases occurring during the song. Our results show that males and females have dimorphic inter-onset intervals during the phrases. Moreover, median frequencies of the unit emitted in the phrases also differ between the sexes, with males showing higher frequencies when compared to females. We have not found an effect of age on the temporal and spectral structure of the phrases. These results indicate that singing in indris has a high behavioral flexibility and varies according to social and individual factors. The flexible spectral structure of the phrases given during the song may underlie perceptual abilities that are relatively unknown in other non-human primates, such as the ability to recognize particular pitch patterns. PMID:27378834

  14. Neural convergence for language comprehension and grammatical class production in highly proficient bilinguals is independent of age of acquisition.

    PubMed

    Consonni, Monica; Cafiero, Riccardo; Marin, Dario; Tettamanti, Marco; Iadanza, Antonella; Fabbro, Franco; Perani, Daniela

    2013-05-01

    In bilinguals, native (L1) and second (L2) languages are processed by the same neural resources that can be modulated by age of second language acquisition (AOA), proficiency level, and daily language exposure and usage. AOA seems to particularly affect grammar processing, where a complete neural convergence has been shown only in bilinguals with parallel language acquisition from birth. Despite the fact that proficiency-related neuroanatomical differences have been well documented in language comprehension (LC) and production, few reports have addressed the influence of language exposure. A still unanswered question pertains to the role of AOA, when proficiency is comparably high across languages, with respect to its modulator effects both on LC and production. Here, we evaluated with fMRI during sentence comprehension and verb and noun production tasks, two groups of highly proficient bilinguals only differing in AOA. One group learned Italian and Friulian in parallel from birth, whereas the second group learned Italian between 3 and 6 years. All participants were highly exposed to both languages, but more to Italian than Friulian. The results indicate a complete overlap of neural activations for the comprehension of both languages, not only in bilinguals from birth, but also in late bilinguals. A slightly extra activation in the left thalamus for the less-exposed language confirms that exposure may affect language processing. Noteworthy, we report for the first time that, when proficiency and exposure are kept high, noun and verb production recruit the same neural networks for L1 and L2, independently of AOA. These results support the neural convergence hypothesis.

  15. Intergenerational transfers in industrialised countries: effects of age distribution and economic institutions.

    PubMed

    Ermisch, J

    1989-01-01

    In Great Britain, using mid 1980s data and assuming no productivity increase over generations thereby making the discount rate and population growth rate 0, the average ages of household consumption and production stood at 46.3 and 41.3 respectively. Further, assuming 2% annual productivity growth and discount rates, the average consumption age was 41.7 and the average production age was 38.7. Therefore, net transfers here passed from the younger to older generations. In Japan, 1985 data shows that, under the same assumptions as Great Britain, the average ages of household consumption and production stood at 50.8 and 44.3 respectively. When assuming 2% annual productivity growth and discount rates, Japan's average consumption age was 41.7 and it's average production age was 38.7. Like Great Britain, Japan's net transfers passed from the younger to older generations. Specifically, production was significantly higher than consumption in the 20-60 year old age group and the reverse occurred in the older age groups. Even though there were similar patterns between the 2 countries, the difference between the average ages of consumption and production for Japan is much larger than for Great Britain. Further, it is even greater than the United States' whose estimates correspond to Japan's and Great Britain's. Specifically, the strength of the transfer effect is higher for Japan than Great Britain or the US because of the longer life expectancy among the Japanese. In addition, due to changes in fertility and mortality, the proportion of the 15 year olds has decreased and the proportion of those or = 65 years old has increased. Therefore net transfers have shifted in favor of the older generations.

  16. The sex distribution of suicides by age in nations of the world.

    PubMed

    Lester, D

    1990-03-01

    The ratio of the male suicide rate to the female suicide rate for each age group in 31 nations of the world was found to be associated with the wealth of the nations. The male/female suicide rate ratio was lower in wealthier nations for older adults and higher in wealthier nations for youths. The male/female suicide rate ratio was associated over the nations among the younger age groups and also among the older age groups. These results suggest that the sex ratio may be differently determined in youths and in older adults.

  17. 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.

  18. Amino acid sequences of lysozymes newly purified from invertebrates imply wide distribution of a novel class in the lysozyme family.

    PubMed

    Ito, Y; Yoshikawa, A; Hotani, T; Fukuda, S; Sugimura, K; Imoto, T

    1999-01-01

    Lysozymes were purified from three invertebrates: a marine bivalve, a marine conch, and an earthworm. The purified lysozymes all showed a similar molecular weight of 13 kDa on SDS/PAGE. Their N-terminal sequences up to the 33rd residue determined here were apparently homologous among them; in addition, they had a homology with a partial sequence of a starfish lysozyme which had been reported before. The complete sequence of the bivalve lysozyme was determined by peptide mapping and subsequent sequence analysis. This was composed of 123 amino acids including as many as 14 cysteine residues and did not show a clear homology with the known types of lysozymes. However, the homology search of this protein on the protein or nucleic acid database revealed two homologous proteins. One of them was a gene product, CELF22 A3.6 of C. elegans, which was a functionally unknown protein. The other was an isopeptidase of a medicinal leech, named destabilase. Thus, a new type of lysozyme found in at least four species across the three classes of the invertebrates demonstrates a novel class of protein/lysozyme family in invertebrates. The bivalve lysozyme, first characterized here, showed extremely high protein stability and hen lysozyme-like enzymatic features.

  19. Amino acid sequences of lysozymes newly purified from invertebrates imply wide distribution of a novel class in the lysozyme family.

    PubMed

    Ito, Y; Yoshikawa, A; Hotani, T; Fukuda, S; Sugimura, K; Imoto, T

    1999-01-01

    Lysozymes were purified from three invertebrates: a marine bivalve, a marine conch, and an earthworm. The purified lysozymes all showed a similar molecular weight of 13 kDa on SDS/PAGE. Their N-terminal sequences up to the 33rd residue determined here were apparently homologous among them; in addition, they had a homology with a partial sequence of a starfish lysozyme which had been reported before. The complete sequence of the bivalve lysozyme was determined by peptide mapping and subsequent sequence analysis. This was composed of 123 amino acids including as many as 14 cysteine residues and did not show a clear homology with the known types of lysozymes. However, the homology search of this protein on the protein or nucleic acid database revealed two homologous proteins. One of them was a gene product, CELF22 A3.6 of C. elegans, which was a functionally unknown protein. The other was an isopeptidase of a medicinal leech, named destabilase. Thus, a new type of lysozyme found in at least four species across the three classes of the invertebrates demonstrates a novel class of protein/lysozyme family in invertebrates. The bivalve lysozyme, first characterized here, showed extremely high protein stability and hen lysozyme-like enzymatic features. PMID:9914527

  20. 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

  1. Body size and fat distribution as predictors of coronary heart disease among middle-aged and older US men.

    PubMed

    Rimm, E B; Stampfer, M J; Giovannucci, E; Ascherio, A; Spiegelman, D; Colditz, G A; Willett, W C

    1995-06-15

    Obesity, android fat distribution, and other anthropometric measures have been associated with coronary heart disease in long-term prospective studies. However, fluctuations in weight due to age-related hormonal changes and changes in lifestyle practices may bias relative risk estimates over a long follow-up period. The authors prospectively studied the association between body mass index (BMI) (kg/m2), waist-to-hip ratio, and height as independent predictors of incident coronary heart disease in a 3-year prospective study among 29,122 US men aged 40-75 years in 1986. The authors documented 420 incident coronary events during the follow-up period. Body mass index, waist-to-hip ratio, short stature, and weight gain since age 21 were associated with an increased risk of coronary heart disease. Among men younger than 65, after adjusting for other coronary risk factors, the relative risk was 1.72 (95% confidence interval (CI) 1.10-2.69) for men with BMI of 25-28.9, 2.61 (95% CI 1.54-4.42) for BMI of 29.0-32.9, and 3.44 (95% CI 1.67-7.09) for obese men with BMI > or = 33 compared with lean men with BMI < 23.0. Among men > or = 65 years of age, the association between BMI and risk of coronary heart disease was much weaker. However, in this age group, the waist-to-hip ratio was a much stronger predictor of risk (relative risk = 2.76, 95% CI 1.22-6.23 between extreme quintiles). These results suggest that for younger men, obesity, independent of fat distribution, is a strong risk factor for coronary heart disease. For older men, measures of fat distribution may be better than body mass index at predicting risk of coronary disease.

  2. 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.

  3. Age-related changes in distribution of body weight on soles of feet for selected actions and postures.

    PubMed

    Yanagida, T; Asami, T

    1997-12-01

    We investigated age-related changes in the distribution of body weight on soles of feet in 878 healthy subjects ranging from 5 to 80 years of age. By modifying Morton's Staticometer, we constructed an instrument for measuring body-weight distribution over three areas of soles of the feet, the big toe (inner forefoot), the other four toes combined (outer forefoot) and the heels for both feet, thus a total of six areas. The weights in the six areas were recorded at the completion of nine selected actions and postures. We observed that for inhaling and exhaling standing postures, generally younger subjects had a ratio close to 1:2:3 for weights recorded for the inner toe:outer toes:heels as observed by Morton, but elderly subjects had a smaller value than 3 for the heel. The body-weight distribution tended to shift from heels to outer toes across age groups, which was more distinctly observed in women than in men.

  4. 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.

  5. 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.

  6. Alterations in the molecular weight distribution of proteins in rat brain synaptosomes during aging and centrophenoxine treatment of old rats.

    PubMed

    Nagy, K; Nagy, I

    1984-12-01

    Properly prepared membrane proteins of brain synaptosomes of 2-, 12- and 24-month-old CFY female rats were filtrated on a Sepharose 2B gel. The molecular weight distribution showed an age-dependence: there was a clear shift toward the higher molecular weights in the adult and old rats. The observed alterations reflect an increased cross-linking of the proteins during aging due most probably to the OH free radical damage of the cell components. Centrophenoxine treatment for 2 months reversed this phenomenon in the old animals: the high molecular weight fractions decreased and the lower ones increased in the treated animals as compared to the old, untreated rats. The results support the membrane hypothesis of aging and contribute to a better understanding of the biological effects of centrophenoxine.

  7. 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. PMID:16295466

  8. 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. PMID:26440040

  9. 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.

  10. Changes in the divorce rate and age distribution in China since the 1980s.

    PubMed

    Zeng, Y; Wu, D

    1997-01-01

    "The divorce rate in China during the 1980s was much higher than before for a number of reasons. In order to understand this phenomenon, the authors will make a comparison between the divorce rates, and the age and duration of the marriage at the time of divorce in the early 1980s and in the late 1980s and early 1990s."

  11. 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

  12. 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...

  13. 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…

  14. 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.

  15. A new method for evaluating age distributions of detrital zircon datasets by incorporating discordant data

    NASA Astrophysics Data System (ADS)

    Reimink, Jesse; Davies, Joshua; Rojas, Xavier; Waldron, John

    2015-04-01

    U-Pb ages from detrital zircons play an important role in sediment provenance studies. However, U-Pb ages from detrital zircon populations often contain a discordant component, which is traditionally removed before the age data are interpreted. Many different processes can create discordant analyses, with the most important being Pb-loss and mixing of distinct zircon age domains during analysis. Discordant ages contain important information regarding the history of a detrital zircon population, for example the timing of Pb-loss or metamorphism, and removing these analyses may significantly bias a zircon dataset. Here we present a new technique for analyzing detrital zircon populations that uses all U-Pb analyses, independent of discordance. We have developed computer code that evaluates the relative likelihood of discordia lines based on their proximity to discordant data points. When two or more data points lie on or near a discordia line the likelihood associated with that line increases. The upper and lower intercepts of each discordia line, as well as the relative likelihood along that line, are stored, and the likelihood of upper and lower intercepts are plotted with age. There are many benefits to using this technique for analysis of detrital zircon datasets. By utilizing the discordant analyses we allow for the addition of upper and lower intercept information to conventional analysis techniques (i.e. probability density functions or kernel density estimators). We are then able to use a much stricter discordance filter (e.g. < 3%) when analyzing 'concordant' data, thereby increasing the reliability of Pb/Pb ages used in the traditional analysis. Additionally, by not rejecting discordant data from zircon datasets we potentially reduce the overall bias in the analysis, which is a critical step in detrital zircon studies. This new technique is relatively quick and uses traditional analytical results, while the upper and lower intercept information is obtained

  16. Effects of aging on the fraction distribution and bioavailability of selenium in three different soils.

    PubMed

    Li, Jun; Peng, Qin; Liang, Dongli; Liang, Sijie; Chen, Juan; Sun, Huan; Li, Shuqi; Lei, Penghui

    2016-02-01

    Aging refers to the processes by which the mobility and bioavailability of metals in soil decline with time. Although long-term aging is a key process that needs to be considered in risk assessment of metals, few investigations has been attempted to determine whether and how residence time influences the selenium (Se) fractions and bioavailability in soil. In this study, the fractions of Se in soils was evaluated, and bioavailability were assessed by measuring Se concentration in pak choi (Brassica chinensis L.). Results showed that the change of soil available Se in all tested soils divided into two phases: rapid decrease at the initial time (42 d) and slow decline thereafter. The second-order equation could describe the decrease processes of available Se in tested soils during the entire incubation time (R(2) > 0.99), while parabolic diffusion equation had less goodness of fit. Those results indicated that Se aging was controlled not only by diffusion process but also by other processes such as nucleation/precipitation, adsorption/desorption with soil component, occlusion by organic matter and reduction reaction. Soil available Se fractions tended to transform to more stable fractions during aging. The changes of Se concentration in pak choi were consistent with the variation in soil available Se content. In addition, 21 d could be reference for the time of Se aging reaching stabilization in krasnozems and fluvo-aquic soil, and 30 d for black soil. Results could provide theoretical basis to formulate environmental quality criterion and choose the equilibrium time before implementing a pot experiment in Se-spiked soils. PMID:26606190

  17. Social Class and Participation in Further Education: Evidence from the Youth Cohort Study of England and Wales

    ERIC Educational Resources Information Center

    Thompson, Ron

    2009-01-01

    This paper examines the class distribution of young people, aged 16-17 years, in colleges of further education (FE) using data from the Youth Cohort Study. It finds that, contrary to popular perceptions of FE colleges as being for "other people's children", middle-class students as well as working-class students are well represented. However, this…

  18. 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

  19. 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.

  20. 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.

  1. Study of 500 patients with limb joint osteoarthritis. I. Analysis by age, sex, and distribution of symptomatic joint sites.

    PubMed Central

    Cushnaghan, J; Dieppe, P

    1991-01-01

    Five hundred subjects with symptomatic limb joint osteoarthritis, who had been referred to a rheumatologist, were enrolled into a continuing study. They comprised 342 women (mean age 65.3) and 158 men (mean age 59.7), with a mean symptom duration of 15.4 years at entry. Only 31 patients (6%) had symptomatic osteoarthritis of one joint alone; however, in a further 205 (41%) the disease was limited to one site. One hundred and eighty two (36.4%) had two sites affected and 82 (16.4%) three or more sites of symptomatic osteoarthritis. Of 847 affected joints the most commonly involved were 349 (41.2%) knees, 254 (30%) hands, and 161 (19%) hips. Hip disease stood out as a separate entity, often occurring alone, and having a stronger male preponderance and different associations than osteoarthritis at other joint sites. Knee and hand disease were significantly associated in women. Obesity, hypertension, and Heberden's nodes were common. The number of sites affected, as well as the distribution, was strongly related to age as well as sex, suggesting that polyarticular osteoarthritis arises from slow acquisition of new joint sites in a non-random distribution. 'Generalised' osteoarthritis did not emerge as a distinct entity. PMID:1994877

  2. 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.

  3. Distribution of epiphytic bacteria on olive leaves and the influence of leaf age and sampling time.

    PubMed

    Ercolani, G L

    1991-12-01

    Mesophilic heterotrophic, aerobic or facultatively anaerobic bacteria that grow on yeast tryptone glucose extract agar were isolated from the surface of olive leaves of 3 or 4 different ages in January, April, July, and October from 1984 to 1989. Unweighted average linkage cluster analysis on either the Jaccard coefficient or the simple matching coefficient recovered 1,701 representative strains in 32 phena defined at the 70% and 80% similarity level, respectively. Of these, 25 were identified to genus or lower level. From the identity of the representative strains, the frequency of occurrence among the phylloplane bacteria over the 6-year period was estimated at 51% forPseudomonas syringae, followed byXanthomonas campestris (6.7%),Erwinia herbicola (6%),Acetobacter aceti (4.7%),Gluconobacter oxydans (4.3%),Pseudomonas fluorescens (3.9%),Bacillus megaterium (3.8%),Leuconostoc mesenteroides subsp.dextranicum (3.1%),Lactobacillus plantarum (2.8%),Curtobacterium plantarum (2.2%),Micrococcus luteus (2.2%),Arthrobacter globiformis (1.4%),Klebsiella planticola (1.2%),Streptococcus faecium (1.2%),Clavibacter sp. (0.98%),Micrococcus sp. (0.82%),Serratia marcescens (0.81%),Bacillus subtilis (0.57%),Cellulomonas flavigena (0.4%),Erwinia sp. (0.37%),Zymomonas mobilis (0.3%),Bacillus sp. (0.29%),Alcaligenes faecalis (0.27%),Erwinia carotovora (0.08%), andPseudomonas aeruginosa (0.04%). Bacterial communities on leaves of a given age at a given time during any one year displayed a very similar structure but differed significantly from those on the leaves of the same age at a different time or on the leaves of a different age at any time during any one year. Communities on the leaves of a given age at a given time of the year were invariably dominated by one or another of only 9 taxa, which accounted for 22 to 98.5% of the isolates from those leaves. The communities on 10- and 13-month-old leaves were invariably made up of fewer taxa than those on younger leaves at the same time

  4. 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.

  5. 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. PMID:27339748

  6. 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.

  7. Star-cluster mass and age distributions of two fields in M83 based on HST/WFC3 observations

    SciTech Connect

    Chandar, Rupali; Whitmore, Bradley C.; Calzetti, Daniela; O'Connell, Robert

    2014-05-20

    We study star clusters in two fields in the nearby spiral galaxy M83 using broadband and narrowband optical imaging taken with the Wide Field Camera 3 onboard the Hubble Space Telescope. We present results on the basis of several different catalogs of star clusters in inner and outer fields, and we conclude that different methods of selection do not strongly affect the results, particularly for clusters older than ≈10 Myr. The age distributions can be described by a power law, dN/dτ∝τ{sup γ}, with γ ≈ –0.84 ± 0.12 in the inner field, and γ ≈ –0.48 ± 0.12 in the outer field for τ ≳ 10 Myr. We bracket the difference, Δγ, between the two fields to be in the 0.18 to 0.36 range, based on estimates of the relative star-formation histories. The mass functions can also be described by a power law, dN/dM∝M {sup β}, with β ≈ –1.98 ± 0.14 and β ≈ –2.34 ± 0.26 in the inner and outer fields, respectively. We conclude that the shapes of the mass and age distributions of the clusters in the two fields are similar, as predicted by the quasi-universal model. Any differences between the two fields are at the ≈2σ-3σ (≈1σ-2σ) level for the age (mass) distributions. Therefore, any dependence of these distributions on the local environment is probably weak. We compare the shapes of the distributions with those predicted by two popular cluster disruption models. We find that both show evidence that the clusters are disrupted at a rate that is approximately independent of their mass. We compare the shapes of the distributions with those predicted by two popular cluster disruption models, and find that both show evidence that the clusters are disrupted at a rate that is approximately independent of their mass, and that observational results do not support the earlier disruption of lower-mass clusters relative to their higher-mass counterparts.

  8. Hippocampal Laminar Distribution of Tau Relates to Alzheimer's Disease and Age of Onset

    PubMed Central

    Seifan, Alon; Marder, Karen S.; Mez, Jesse; Noble, James M.; Cortes, Etty P.; Vonsattel, Jean Paul; Honig, Lawrence S.

    2015-01-01

    Background Cerebral deposition of phospho-tau in Alzheimer's disease (AD) occurs with varying patterns within hippocampus. Lamina-specific tau changes in AD may reflect trans-synaptic propagation of phospho-tau along neuroanatomical pathways. Objective To study patterns of tau deposition within inner (IML) and outer (OML) molecular layers of dentate gyrus and their clinical and neuropathological correlates. Methods 98 consecutive autopsied brains from the Columbia University Brain Bank were stained for phospho-tau using AT-8. Staining density was rated as High versus Low within IML and OML. Four patterns were observed among the 98 brains: High IML&OML, n = 44; High OML Only (n = 35); High IML Only (n = 5); and Low IML&OML (n = 14). Demographic, clinical, and neuropathological characteristics of these four groups were compared. Results High IML&OML subjects, versus High OML Only, were more likely to fulfill CERAD criteria for Definite AD (93% versus 66%, p < 0.01) and to have higher median Braak stage (6 versus 5, p < 0.01) and earlier mean age of onset (65.9 versus 73.7 y, p = 0.02), with similar symptom duration. Using logistic regression, the association between High IML&OML and AD remained significant after adjustment for demographics but not symptom duration. In the 70 subjects with Definite AD, High IML&OML was associated with younger age of onset (mean difference 3.7 years, 95%CI −6.7 to −0.7, p < 0.01), after adjustment for demographics and symptom duration. Conclusions Phospho-tau pathology, when prominent within both IML and OML, is associated with CERAD diagnosis of Definite AD and earlier age of onset in AD. Laminar patterns of tau deposition reflect regional involvements during disease course. PMID:25079799

  9. 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.

  10. Trends in maternal age distribution and the live birth prevalence of Down's syndrome in England and Wales: 1938-2010.

    PubMed

    Wu, Jianhua; Morris, Joan K

    2013-09-01

    There have been concerns about the effects of increases in maternal age since the 1980s on the prevalence of Down's syndrome. This study examined changes in the distribution of maternal age in England and Wales from 1938 to 2010. The live birth prevalence of Down's syndrome in the absence of screening and subsequent termination was estimated using the numbers of babies born in England and Wales according to maternal age and the maternal age-related risk of a birth with Down's syndrome. The proportion of women age 35 years or older at the time of giving birth reached a peak of 20% in 1945, declined to 5.5% in 1977 and rose to 20% in 2007. In the absence of screening and subsequent termination, the estimated live birth prevalence of Down's syndrome would have mirrored these changes (2.3 per 1000 births in 1945, 1.2 per 1000 in 1976 and 2.2 per 1000 in 2007). The observed live birth prevalence (recorded by the National Down Syndrome Cytogenetic Register) was1.0 per 1000 from 1989 to 2010, due to screening and subsequent termination. In conclusion since the 1980s there has been an increase in the mean maternal age and in the expected prevalence of Down's syndrome. When put in a longer historical context the current expected live birth prevalence is similar to that in the 1940s and the observed live birth prevalence is about 54% less than expected, due to screening and subsequent termination, and has remained reasonably constant since 1989 at 1.0 per 1000 births.

  11. 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.

  12. Provenance from zircon U-Pb age distributions in crustally contaminated granitoids

    NASA Astrophysics Data System (ADS)

    Bahlburg, Heinrich; Berndt, Jasper

    2016-05-01

    The basement of sedimentary basins is often entirely covered by a potentially multi-stage basin fill and therefore removed from direct observation and sampling. Melts intruding through the basin stratigraphy at a subsequent stage in the geological evolution of a region may assimilate significant volumes of country rocks. This component may be preserved in the intrusive body either as xenoliths or it may be reflected only by the age spectrum of incorporated zircons. Here we present the case of an Ordovician calc-alkaline intrusive belt in NW Argentina named the "Faja Eruptiva de la Puna Oriental" (Faja Eruptiva), which in the course of intrusion sampled the unexposed and unknown basement of the Ordovician basin in this region, and parts of the basin stratigraphy. We present new LA-ICP-MS U-Pb ages on zircons from 9 granodiorites and granites of the Faja Eruptiva. The main part of the Faja Eruptiva intruded c. 445 Ma in the Late Ordovician. The zircon ages obtained from the intrusive rocks have a large spread between 2683.5 ± 21.6 and 440.0 ± 4.9 Ma and reflect the underlying crust and may be interpreted in several ways. The inherited zircons may have been derived from the oldest known unit in the region, the thick siliciclastic turbidite successions of the upper Neoproterozoic-lower Cambrian Puncoviscana Formation, which is inferred to represent the basement of the NW Argentina. The basement to the Puncoviscana Formation is not known. Alternatively, the inherited zircons may reflect the geochronological structure of the entire unexposed Early Paleozoic crust underlying this region of which the Puncoviscana Formation was only one component. This crust likely contained rocks pertaining to and detritus derived from earlier orogenic cycles of the southwestern Amazonia craton, including sources of Early Meso- and Paleoproterozoic age. Detritus derived, in turn, from the Faja Eruptiva intrusive belt reflects the origin of the granitoids as well as the inherited

  13. Marginal adaptation of an etch-and-rinse adhesive with a new type of solvent in class II cavities after artificial aging.

    PubMed

    Manhart, Juergen; Trumm, Cordula

    2010-12-01

    This in vitro study evaluated the marginal adaptation of etch-and-rinse adhesives. Standardized class II cavities were cut in 40 human molars with one proximal box limited within enamel and one proximal box extending into dentin. Teeth were assigned randomly to five groups (n = 8) and restored with incrementally placed composite restorations. Five combinations were tested: G1, XP Bond + Ceram-X Mono; G2, P&B NT + Ceram-X Mono; G3, Optibond Solo Plus + Ceram-X Mono; R1, Syntac Classic + Tetric EvoCeram; R2, Scotchbond 1 XT + Z250. After finishing and polishing, teeth were stored for 48 h in water at 37°C before subjected to artificial aging by thermal stress (5/55°C; ×2,000; 30 s) and mechanical loading (50 N; ×50,000). Marginal adaptation of the restorations was evaluated in a SEM (×200) using a replica technique. Statistical analysis was performed with nonparametric test methods (p < 0.05). The percentages of "perfect margin" after aging ranged from 95.9% to 99.6% in enamel and 85.9% to 96.0% in dentin. "Marginal opening" was observed between 0.1% to 2.6% in enamel and 2.6% to 11.8% in dentin. In enamel and dentin, both, G3 showed significantly more gap formation than G1 and G2. Comparing marginal adaptation to enamel and dentin within each group yielded only for G1 no significant differences. Tert-butanol-based XP Bond showed excellent marginal adaptation in both enamel and dentin.

  14. Impact of Hydrologic and Micro-topographic Variabilities on Spatial Distribution of Mean Soil-Nitrogen Age

    NASA Astrophysics Data System (ADS)

    Woo, D.; Kumar, P.

    2015-12-01

    Excess reactive nitrogen in soils of intensively managed agricultural fields 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 3-dimensional model to characterize the spatially distributed ``age" of soil-nitrogen (nitrate and ammonia-ammonium) across a watershed. We use the general theory of age, which provides an assessment of the elapsed time since nitrogen is introduced into the soil system. Micro-topographic variability incorporates heterogeneity of nutrient transformations and transport associated with topographic depressions that form temporary ponds and produce prolonged periods of anoxic conditions, and roadside agricultural ditches that support rapid surface movement. This modeling effort utilizes 1-m Light Detection and Ranging (LiDAR) data. We find a significant correlation between hydrologic variability and mean nitrate age that enables assessment of preferential flow paths of nitrate leaching. The estimation of the mean nitrogen age can thus serve as a tool to disentangle complex nitrogen dynamics by providing the analysis of the time scales of soil-nitrogen transformation and transport processes without introducing additional parameters.

  15. 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.

  16. Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking

    SciTech Connect

    Volkán-Kacsó, Sándor

    2014-06-14

    A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of “bright” and “dark” states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a “bright” and a “dark” maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed.

  17. Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking

    NASA Astrophysics Data System (ADS)

    Volkán-Kacsó, Sándor

    2014-06-01

    A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of "bright" and "dark" states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a "bright" and a "dark" maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed.

  18. Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking.

    PubMed

    Volkán-Kacsó, Sándor

    2014-06-14

    A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of "bright" and "dark" states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a "bright" and a "dark" maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed.

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

    PubMed

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

    2015-03-01

    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, that is, 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 this study, we used functional magnetic resonance imaging 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 (9-14 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 on the type of relation.

  20. 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

  1. Comparisons of the galaxy age, stellar velocity dispersion and K-band luminosity distributions between grouped galaxies and isolated ones

    NASA Astrophysics Data System (ADS)

    Wu, Ping; Deng, Xin-Fa

    2016-02-01

    In two volume-limited Main galaxy samples of the Sloan Digital Sky Survey Data Release 10 (SDSS DR10), we compare the age, stellar velocity dispersion and K-band luminosity distributions of grouped galaxies with those of isolated galaxies, to explore the environmental dependence of these properties of galaxies. It is found that grouped galaxies have preferentially larger stellar velocity dispersions and are preferentially older than isolated galaxies. We also note apparent difference of K-band luminosity distribution at both extremes of density in the luminous volume-limited Main galaxy sample: grouped galaxies are preferentially more luminous than isolated galaxies, while this difference in the faint volume-limited Main galaxy sample is very small.

  2. 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

  3. 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.

  4. PIK3CA-associated developmental disorders exhibit distinct classes of mutations with variable expression and tissue distribution

    PubMed Central

    Timms, Andrew E.; Conti, Valerio; Girisha, Katta M.; Martin, Beth; Olds, Carissa; Collins, Sarah; Park, Kaylee; Carter, Melissa; Krägeloh-Mann, Inge; Chitayat, David; Parikh, Aditi Shah; Bradshaw, Rachael; Torti, Erin; Braddock, Stephen; Burke, Leah; Ghedia, Sondhya; Stephan, Mark; Stewart, Fiona; Prasad, Chitra; Napier, Melanie; Saitta, Sulagna; Straussberg, Rachel; Gabbett, Michael; O’Connor, Bridget C.; Yin, Lim Jiin; Lai, Angeline Hwei Meeng; Martin, Nicole; McKinnon, Margaret; Addor, Marie-Claude; Schwartz, Charles E.; Lanoel, Agustina; Conway, Robert L.; Devriendt, Koenraad; Tatton-Brown, Katrina; Pierpont, Mary Ella; Painter, Michael; Worgan, Lisa; Reggin, James; Hennekam, Raoul; Pritchard, Colin C.; Aracena, Mariana; Gripp, Karen W.; Cordisco, Maria; Van Esch, Hilde; Garavelli, Livia; Curry, Cynthia; Goriely, Anne; Kayserilli, Hulya; Shendure, Jay; Graham, John; Guerrini, Renzo; Dobyns, William B.

    2016-01-01

    Mosaicism is increasingly recognized as a cause of developmental disorders with the advent of next-generation sequencing (NGS). Mosaic mutations of PIK3CA have been associated with the widest spectrum of phenotypes associated with overgrowth and vascular malformations. We performed targeted NGS using 2 independent deep-coverage methods that utilize molecular inversion probes and amplicon sequencing in a cohort of 241 samples from 181 individuals with brain and/or body overgrowth. We identified PIK3CA mutations in 60 individuals. Several other individuals (n = 12) were identified separately to have mutations in PIK3CA by clinical targeted-panel testing (n = 6), whole-exome sequencing (n = 5), or Sanger sequencing (n = 1). Based on the clinical and molecular features, this cohort segregated into three distinct groups: (a) severe focal overgrowth due to low-level but highly activating (hotspot) mutations, (b) predominantly brain overgrowth and less severe somatic overgrowth due to less-activating mutations, and (c) intermediate phenotypes (capillary malformations with overgrowth) with intermediately activating mutations. Sixteen of 29 PIK3CA mutations were novel. We also identified constitutional PIK3CA mutations in 10 patients. Our molecular data, combined with review of the literature, show that PIK3CA-related overgrowth disorders comprise a discontinuous spectrum of disorders that correlate with the severity and distribution of mutations. PMID:27631024

  5. PIK3CA-associated developmental disorders exhibit distinct classes of mutations with variable expression and tissue distribution

    PubMed Central

    Mirzaa, Ghayda; Timms, Andrew E.; Conti, Valerio; Boyle, Evan August; Girisha, Katta M.; Martin, Beth; Kircher, Martin; Olds, Carissa; Juusola, Jane; Collins, Sarah; Park, Kaylee; Carter, Melissa; Glass, Ian; Krägeloh-Mann, Inge; Chitayat, David; Parikh, Aditi Shah; Bradshaw, Rachael; Torti, Erin; Braddock, Stephen; Burke, Leah; Ghedia, Sondhya; Stephan, Mark; Stewart, Fiona; Prasad, Chitra; Napier, Melanie; Saitta, Sulagna; Straussberg, Rachel; Gabbett, Michael; O’Connor, Bridget C.; Keegan, Catherine E.; Yin, Lim Jiin; Lai, Angeline Hwei Meeng; Martin, Nicole; McKinnon, Margaret; Addor, Marie-Claude; Boccuto, Luigi; Schwartz, Charles E.; Lanoel, Agustina; Conway, Robert L.; Devriendt, Koenraad; Tatton-Brown, Katrina; Pierpont, Mary Ella; Painter, Michael; Worgan, Lisa; Reggin, James; Hennekam, Raoul; Tsuchiya, Karen; Pritchard, Colin C.; Aracena, Mariana; Gripp, Karen W.; Cordisco, Maria; Esch, Hilde Van; Garavelli, Livia; Curry, Cynthia; Goriely, Anne; Kayserilli, Hulya; Shendure, Jay; Graham, John; Guerrini, Renzo; Dobyns, William B.

    2016-01-01

    Mosaicism is increasingly recognized as a cause of developmental disorders with the advent of next-generation sequencing (NGS). Mosaic mutations of PIK3CA have been associated with the widest spectrum of phenotypes associated with overgrowth and vascular malformations. We performed targeted NGS using 2 independent deep-coverage methods that utilize molecular inversion probes and amplicon sequencing in a cohort of 241 samples from 181 individuals with brain and/or body overgrowth. We identified PIK3CA mutations in 60 individuals. Several other individuals (n = 12) were identified separately to have mutations in PIK3CA by clinical targeted-panel testing (n = 6), whole-exome sequencing (n = 5), or Sanger sequencing (n = 1). Based on the clinical and molecular features, this cohort segregated into three distinct groups: (a) severe focal overgrowth due to low-level but highly activating (hotspot) mutations, (b) predominantly brain overgrowth and less severe somatic overgrowth due to less-activating mutations, and (c) intermediate phenotypes (capillary malformations with overgrowth) with intermediately activating mutations. Sixteen of 29 PIK3CA mutations were novel. We also identified constitutional PIK3CA mutations in 10 patients. Our molecular data, combined with review of the literature, show that PIK3CA-related overgrowth disorders comprise a discontinuous spectrum of disorders that correlate with the severity and distribution of mutations.

  6. 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.

  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. "Racializing" Class

    ERIC Educational Resources Information Center

    Hatt-Echeverria, Beth; Urrieta, Luis, Jr.

    2003-01-01

    In an effort to explore how racial and class oppressions intersect, the authors use their autobiographical narratives to depict cultural and experiential continuity and discontinuity in growing up white working class versus Chicano working class. They specifically focus on "racializing class" due to the ways class is often used as a copout by…

  9. Barrier height distribution and dipolar relaxation in metal-insulator-semiconductor junctions with molecular insulator: Ageing effects

    NASA Astrophysics Data System (ADS)

    Fadjie-Djomkam, A. B.; Ababou-Girard, S.; Godet, C.

    2012-12-01

    Electrical transport through molecular monolayers being very sensitive to disorder effects, admittance and current density characteristics of Hg//C12H25 - n Si junctions incorporating covalently bonded n-alkyl molecular layers, were investigated at low temperature (150-300 K), in the as-grafted state and after ageing at the ambient. This comparison reveals local oxidation effects both at the submicron scale in the effective barrier height distribution and at the molecular scale in the dipolar relaxation. In the bias range dominated by thermionic emission and modified by the tunnel barrier (TB) attenuation, exp(-β0dT), where dT is the thickness of the molecular tunnel barrier and β0 is the inverse attenuation length at zero applied bias, some excess current is attributed to a distribution of low barrier height patches. Complementary methods are used to analyze the current density J(V, T) characteristics of metal-insulator-semiconductor tunnel diodes. Assuming a Gaussian distribution of barrier heights centered at qΦB provides an analytical expression of the effective barrier height, qΦEFF(T)=qΦB+(kT)β0dT-(qδΦ)2/2kT; this allows fitting of the distribution standard deviation δΦ and tunnel parameter (β0dT) over a wide temperature range. In a more realistic modeling including the voltage dependence of barrier height and circular patch area, the so-called "pinch-off" effect is described by a distribution of parameter γ =3(ΔPRP2/4)1/3, which combines interface potential modulation and patch area variations. An arbitrary distribution of γ values, fitted to low-temperature J(V) data, is equally well described by Gaussian or exponential functions. Ageing in air also increases the interface oxidation of Si substrate and affects the density of localized states near mid gap, which typically rises to the high 1011 eV-1 cm-2 range, as compared with DS < 1011 eV-1 cm-2 in the as-grafted state. The bias-independent relaxation observed near 1 kHz at low temperature

  10. HLA class II profile and distribution of HLA-DRB1 and HLA-DQB1 alleles and haplotypes among Lebanese and Bahraini Arabs.

    PubMed

    Almawi, Wassim Y; Busson, Marc; Tamim, Hala; Al-Harbi, Einas M; Finan, Ramzi R; Wakim-Ghorayeb, Saria F; Motala, Ayesha A

    2004-07-01

    The gene frequencies of HLA class II alleles were studied in 95 healthy Lebanese Arab and 72 healthy Bahraini Arab subjects. Our aim was to establish the genetic relationship between Bahraini and Lebanese Arabs in terms of HLA class II gene and haplotype frequencies and to compare these results with frequencies for other countries with populations of Caucasian and non-Caucasian descent. Subjects were unrelated and of both sexes, and HLA-DRB1 and -DQB1 genotyping was done by the PCR sequence-specific primer technique. Comparative analysis of the HLA-DR and -DQ alleles revealed differences in the allelic distribution among Bahraini and Lebanese subjects. Analysis of the 25 HLA-DRB1 alleles that have been investigated showed that the DRB1*040101 and DRB1*110101 alleles were more frequent among Lebanese, whereas DRB1*030101 and DRB1*160101 alleles were more frequent among Bahrainis. Similarly, of the seven HLA-DQB1 alleles analyzed, the presence of DQB1*0201 was more frequent among Bahrainis, whereas DQB1*030101 was more frequent among Lebanese. The DRB1*160101-DQB1*050101 (0.1318 versus 0.0379%) and DRB1*030101-DQB1*0201 (0.1202 versus 0.0321%) haplotypes were more frequent among Bahrainis, while the DRB1*110101-DQB1*030101 (0.3142 versus 0.1198%) and DRB1*040101-DQB1*0302 (0.1416 versus 0.0278%) haplotypes were more frequent in Lebanese subjects. Furthermore, a high prevalence of the DRB1*040101-DRB1*110101-DQB1*0302-DQB1*030101 (12.63 versus 1.35%, P = 0.015) and the homozygous DRB1*110101-DRB1*110101-DQB1*030101-DQB1*030101 (7.37 versus 0.00%, P = 0.046) genotypes was seen among Lebanese, and DRB1*070101-DRB1*160101-DQB1*0201-DQB1*050101 (6.76 versus 0.00%, P = 0.034) was seen more frequently among Bahraini subjects. Our results underline significant differences between these two populations in HLA class II distribution, provide basic information for further studies of major histocompatibility complex heterogeneity among Arabic-speaking countries, and serve as a

  11. HLA Class II Profile and Distribution of HLA-DRB1 and HLA-DQB1 Alleles and Haplotypes among Lebanese and Bahraini Arabs

    PubMed Central

    Almawi, Wassim Y.; Busson, Marc; Tamim, Hala; Al-Harbi, Einas M.; Finan, Ramzi R.; Wakim-Ghorayeb, Saria F.; Motala, Ayesha A.

    2004-01-01

    The gene frequencies of HLA class II alleles were studied in 95 healthy Lebanese Arab and 72 healthy Bahraini Arab subjects. Our aim was to establish the genetic relationship between Bahraini and Lebanese Arabs in terms of HLA class II gene and haplotype frequencies and to compare these results with frequencies for other countries with populations of Caucasian and non-Caucasian descent. Subjects were unrelated and of both sexes, and HLA-DRB1 and -DQB1 genotyping was done by the PCR sequence-specific primer technique. Comparative analysis of the HLA-DR and -DQ alleles revealed differences in the allelic distribution among Bahraini and Lebanese subjects. Analysis of the 25 HLA-DRB1 alleles that have been investigated showed that the DRB1*040101 and DRB1*110101 alleles were more frequent among Lebanese, whereas DRB1*030101 and DRB1*160101 alleles were more frequent among Bahrainis. Similarly, of the seven HLA-DQB1 alleles analyzed, the presence of DQB1*0201 was more frequent among Bahrainis, whereas DQB1*030101 was more frequent among Lebanese. The DRB1*160101-DQB1*050101 (0.1318 versus 0.0379%) and DRB1*030101-DQB1*0201 (0.1202 versus 0.0321%) haplotypes were more frequent among Bahrainis, while the DRB1*110101-DQB1*030101 (0.3142 versus 0.1198%) and DRB1*040101-DQB1*0302 (0.1416 versus 0.0278%) haplotypes were more frequent in Lebanese subjects. Furthermore, a high prevalence of the DRB1*040101-DRB1*110101-DQB1*0302-DQB1*030101 (12.63 versus 1.35%, P = 0.015) and the homozygous DRB1*110101-DRB1*110101-DQB1*030101-DQB1*030101 (7.37 versus 0.00%, P = 0.046) genotypes was seen among Lebanese, and DRB1*070101-DRB1*160101-DQB1*0201-DQB1*050101 (6.76 versus 0.00%, P = 0.034) was seen more frequently among Bahraini subjects. Our results underline significant differences between these two populations in HLA class II distribution, provide basic information for further studies of major histocompatibility complex heterogeneity among Arabic-speaking countries, and serve as a

  12. 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

  13. 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

  14. 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

  15. 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.

  16. AGE AND MASS CONSTRAINTS FOR A YOUNG MASSIVE CLUSTER IN M31 BASED ON SPECTRAL ENERGY DISTRIBUTION FITTING

    SciTech Connect

    Ma Jun; Wang Song; Wu Zhenyu; Fan Zhou; Yang Yanbin; Zhang Tianmeng; Wu Jianghua; Zhou Xu; Jiang Zhaoji; Chen Jiansheng

    2011-03-15

    VDB0-B195D is a massive, blue star cluster in M31. It was observed as part of the Beijing-Arizona-Taiwan-Connecticut (BATC) Multicolor Sky Survey using 15 intermediate-band filters covering a wavelength range of 3000-10000 A. Based on aperture photometry, we obtain its spectral energy distribution (SED) as defined by the 15 BATC filters. We apply previously established relations between the BATC intermediate-band and the Johnson-Cousins UBVRI broadband systems to convert our BATC photometry to the standard system. A detailed comparison shows that our newly derived VRI magnitudes are fully consistent with previous results, while our new B magnitude agrees to within 2{sigma}. In addition, we determine the cluster's age and mass by comparing its SED (from 3000 to 20000 A, comprising photometric data in the 15 BATC intermediate bands, optical broadband BVRI, and Two Micron All Sky Survey near-infrared JHK{sub s} data) with theoretical stellar population synthesis models, resulting in age and mass determinations of 60.0 {+-} 8.0 Myr and (1.1-1.6) x 10{sup 5} M{sub sun}, respectively. This age and mass confirms previous suggestions that VDB0-B195D is a young massive cluster in M31.

  17. Identification of defect distribution at ferroelectric domain walls from evolution of nonlinear dielectric response during the aging process

    NASA Astrophysics Data System (ADS)

    Mokrý, Pavel; Sluka, Tomáš

    2016-02-01

    The motion of ferroelectric domain walls greatly contributes to the macroscopic dielectric and piezoelectric response of ferroelectric materials. The domain-wall motion through the ferroelectric material is, however, hindered by pinning on crystal defects, which substantially reduces these contributions. Here, using thermodynamic models based on the Landau-Ginzburg-Devonshire theory, we find a relation between the microscopic reversible motion of nonferroelastic 180∘ domain walls interacting with a periodic array of pinning centers and the nonlinear macroscopic permittivity. We show that the reversible motion of domain walls can be split into two basic modes: first, the bending of a domain wall between pinning centers, and, second, the uniform movement of the domain-wall plane. We show that their respective contributions may change when the distribution of pinning centers is rearranged during the material aging. We demonstrate that it is possible to indicate which mechanism of the domain-wall motion is affected during material aging. This allows one to judge whether the defects only homogeneously accumulate at domain walls or prefer to align in certain directions inside the domain-wall plane. We suggest that this information can be obtained using simple macroscopic dielectric measurements and a proper analysis of the nonlinear response. Our results may therefore serve as a simple and useful tool to obtain details on domain-wall pinning in an aging process.

  18. Geographic distribution of HIV stigma among women of childbearing age in rural Kenya

    PubMed Central

    Akullian, Adam; Kohler, Pamela; Kinuthia, John; Laserson, Kayla; Mills, Lisa A.; Okanda, John; Olilo, George; Ombok, Maurice; Odhiambo, Frank; Rao, Deepa; Wakefield, Jonathan; John-Stewart, Grace

    2015-01-01

    Objective(s) HIV stigma is considered to be a major driver of the HIV/AIDS pandemic, yet there is a limited understanding of its occurrence. We describe the geographic patterns of two forms of HIV stigma in a cross-sectional sample of women of childbearing age from western Kenya: internalized stigma (associated with shame) and externalized stigma (associated with blame). Design Geographic studies of HIV stigma provide a first step in generating hypotheses regarding potential community-level causes of stigma and may lead to more effective community-level interventions. Methods Spatial regression using generalized additive models and point pattern analyses using K-functions were used to assess the spatial scale(s) at which each form of HIV stigma clusters, and to assess whether the spatial clustering of each stigma indicator was present after adjustment for individual-level characteristics. Results There was evidence that externalized stigma (blame) was geographically heterogeneous across the study area, even after controlling for individual-level factors (P=0.01). In contrast, there was less evidence (P=0.70) of spatial trend or clustering of internalized stigma (shame). Conclusion Our results may point to differences in the underlying social processes motivating each form of HIV stigma. Externalized stigma may be driven more by cultural beliefs disseminated within communities, whereas internalized stigma may be the result of individual-level characteristics outside the domain of community influence. These data may inform community-level interventions to decrease HIV-related stigma, and thus impact the HIV epidemic. PMID:24835356

  19. Event-based distributed set-membership filtering for a class of time-varying non-linear systems over sensor networks with saturation effects

    NASA Astrophysics Data System (ADS)

    Wei, Guoliang; Liu, Shuai; Wang, Licheng; Wang, Yongxiong

    2016-07-01

    In this paper, based on the event-triggered mechanism, the problem of distributed set-membership filtering is concerned for a class of time-varying non-linear systems over sensor networks subject to saturation effects. Different from the traditional periodic sample-data approach, the filter is updated only when the predefined event is satisfied, which the event is defined according to the measurement output. For each node, the proposed novel event-triggered mechanism can reduce the unnecessary information transmission between sensors and filters. The purpose of the addressed problem is to design a series of distributed set-membership filters, for all the admissible unknown but bounded noises, non-linearities and sensor saturation, such that the set of all possible states can be determined. The desired filter parameters are obtained by solving a recursive linear matrix inequality that can be computed recursively using the available MATLAB toolbox. Finally, a simulation example is exploited to show the effectiveness of the proposed design approach in this paper.

  20. Possibility of a gas-cooled Peltier current lead in the 200 m-class superconducting direct current transmission and distribution system of CASER-2

    NASA Astrophysics Data System (ADS)

    Kawahara, Toshio; Emoto, Masahiko; Watanabe, Hirofumi; Hamabe, Makoto; Yamaguchi, Sataro; Hikichi, Yasuo; Minowa, Masahiro

    Global energy problems should be solved quickly, and superconducting applications are highly demanded as energy saving technologies. Among them, long-distance superconducting transmission seems to be one of the most promising for energy saving by energy sharing. On the other hand, such large systems can be constructed from smaller network systems that can be enhanced by scaling up to the superconducting grid. Reducing heat leak to the low temperature end is the most important aspect of technology for practical superconducting applications, and heat leak reduction at the terminal is a key goal especially for small-length applications. At Chubu University, we have developed a 200 m-class superconducting direct current transmission and distribution system (CASER-2), in which we also used a Peltier current lead (PCL) as heat insulation at the terminal. PCL is composed of a thermoelectric material and a copper lead. In actual transmission and distribution applications, the cables are also cooled by the coolant. After the circulation, the coolant could also be used to cool the current lead. We will discuss the performance of such gas-cooled systems as the total performance of applied superconducting systems using the experimental parameters obtained in CASER-2.

  1. Sorption and distribution of aged atrazine residues in the drainage system of an outdoor lysimeter experiment

    NASA Astrophysics Data System (ADS)

    Jablonowski, N. D.; Schäffer, A.; Burauel, P.

    2009-04-01

    Even though the environmental impact of the herbicide atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is a matter of controversy, it is still extensively applied for agricultural purposes. Particularly in the US, atrazine has been applied to approximately 70% of all corn acreages in the last 18 years. Atrazine is banned in the EU but its use is increasing in countries like China, Brazil and India. Therefore, the worldwide soil burden of this compound must be enormous. Atrazine has been found to be highly persistent in the environment and it has been suggested that it is moderately mobile in the soil profile. As a result, it is found in most groundwater aquifers and surface waters in agricultural areas in the US. Even in Germany, where it was prohibited in 1991, it is still found in groundwater wells below agriculturally used land where it was formerly applied. For a long-term outdoor lysimeter experiment with a disturbed soil column, a drainage system of fine gravel was originally embedded at the bottom of the lysimeter. In this drainage system, atrazine and its metabolite 2-hydroxy-atrazine were extracted as long as 22 years after the last atrazine application. Due to the radiolabelling, the spatial distribution of the atrazine residues can be evaluated in fractions like fine clay particles attached to the gravel or in the gravel itself. Approximately 2% of the total gravel consisted of carbonaceous, slag-like particles which might retain most of the atrazine and its residues. The latest data will be presented at the session.

  2. The morphologic and neurochemical basis of dementia: aging, hierarchical patterns of lesion distribution and vulnerable neuronal phenotype.

    PubMed

    Hof, P R; Giannakopoulos, P; Vickers, J C; Bouras, C; Morrison, J H

    1995-01-01

    Alzheimer's disease is the most common form of dementia in elderly individuals. Approximately 11% of the population older than 65, and up to 50% of individuals over 85 qualify as having "probable Alzheimer's disease" on the basis of clinical evaluation. Since the early description of the clinical symptoms and neuropathologic features of Alzheimer's disease, there has been an extraordinary growth in the knowledge of the morphologic and molecular characteristics of Alzheimer's disease. Although the pathogenetic events that lead to dementia are not yet fully understood, several hypotheses regarding the formation of the hallmark pathologic structures of Alzheimer's disease have been proposed. In this context, the use of specific histochemical techniques in the primate brain has greatly expanded our understanding of neuron typology, connectivity and circuit distribution in relation to neurochemical identity. In this respect, very specific subsets of cortical neurons and cortical afferents can be identified by their particular content of certain neurotransmitters and structural proteins. In this article, we discuss the possible relationships between the distribution of pathologic changes in aging, Alzheimer's disease, and possibly related dementing conditions, in the context of the specific elements of the cortical circuitry that are affected by these alterations. Also, evidence for links between the neurochemical phenotype of a given neuron and its relative vulnerability or resistance to the degenerative process are presented in order to correlate the distribution of cellular pathologic changes, neurochemical characteristics related to vulnerability, and affected cortical circuits.

  3. MitoTimer probe reveals the impact of autophagy, fusion, and motility on subcellular distribution of young and old mitochondrial protein and on relative mitochondrial protein age.

    PubMed

    Ferree, Andrew W; Trudeau, Kyle; Zik, Eden; Benador, Ilan Y; Twig, Gilad; Gottlieb, Roberta A; Shirihai, Orian S

    2013-11-01

    To study mitochondrial protein age dynamics, we targeted a time-sensitive fluorescent protein, MitoTimer, to the mitochondrial matrix. Mitochondrial age was revealed by the integrated portions of young (green) and old (red) MitoTimer protein. Mitochondrial protein age was dependent on turnover rates as pulsed synthesis, decreased import, or autophagic inhibition all increased the proportion of aged MitoTimer protein. Mitochondrial fusion promotes the distribution of young mitochondrial protein across the mitochondrial network as cells lacking essential fusion genes Mfn1 and Mfn2 displayed increased heterogeneity in mitochondrial protein age. Experiments in hippocampal neurons illustrate that the distribution of older and younger mitochondrial protein within the cell is determined by subcellular spatial organization and compartmentalization of mitochondria into neurites and soma. This effect was altered by overexpression of mitochondrial transport protein, RHOT1/MIRO1. Collectively our data show that distribution of young and old protein in the mitochondrial network is dependent on turnover, fusion, and transport.

  4. 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

  5. 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.

  6. Age and spatial distribution of Holocene permafrost in Norway - model results and implications for glacier-permafrost interaction

    NASA Astrophysics Data System (ADS)

    Lilleoren, K. S.; Etzelmuller, B.; Gisnås, K.; Humlum, O.

    2011-12-01

    Following the last glaciation, cryogenic processes related to valley and cirque glaciers, permafrost and seasonal frost have dominated the Norwegian landscape development in high-mountain environments. This is evident by different landscape and landform features, like rock glaciers, block fields, palsas, ice-wedge polygons and ice-cored moraines. For Scandinavia the present regional distribution of mountain permafrost is reasonably well known, both through ground temperature measurements in boreholes, geophysical soundings and spatial modelling exercises. An important question in this context is the dynamics of permafrost during the Holocene, as a major factor for landscape development and geomorphological processes in high mountain areas of Scandinavia. In the present study mean annual air temperature deviation curves through Holocene have been compiled to drive a 1D heat flow model over the last 10 ka period for several mountain sites in Norway. At each site temperature-monitored boreholes were used to calibrate the model. Both an annual run and a seasonal run including monthly temperature variations were performed for each site. In addition the spatial distribution of permafrost during selected time periods of the Holocene were addressed using an equilibrium permafrost model on a 1*1 km resolution. The results of this study indicate an altitudinal zonation of relative permafrost age in Norway, where permafrost has existed continuously since the deglaciation in the highest areas, while large areas that is underlain by permafrost today were degraded during the Holocene Thermal Maximum (HTM). In all boreholes the deepest simulated permafrost occurred during the Little Ice Age (LIA), and also the largest areal distribution of Holocene permafrost in Norway is connected to the LIA. In addition, there exist a clear connection between the distribution of permafrost and presence of blockfields. These findings have several implications, such as for the subglacial

  7. Quantitative changes in the frequency and distribution of the C-cell population in the rat thyroid gland with age.

    PubMed

    Martín-Lacave, I; Conde, E; Montero, C; Galera-Davidson, H

    1992-10-01

    The development of calcitonin cells (C-cells) was investigated in rat thyroid glands from birth to 120 days, using an immunoperoxidase technique and a point-counting method. The proportion of C-cells to follicular cells was 4.5% on the day of birth and increased progressively to 10.4% by 120 days. The highest density of C-cells was noted in the mid-region of the lobes along a longitudinal axis. The caudal and cephalic regions of the lobes contained smaller numbers of C-cells. The C-cells tended to be more numerous in the posterior aspects of the lobes. Although the numbers of C-cells in 120-day-old animal were markedly increased as compared to animals at the time of birth, the cell distributions within the glands were similar at all ages.

  8. The Modeling of Time-Varying Stream Water Age Distributions: Preliminary Investigations with Non-Conservative Solutes

    NASA Astrophysics Data System (ADS)

    Wilusz, D. C.; Harman, C. J.; Ball, W. P.

    2014-12-01

    Modeling the dynamics of chemical transport from the landscape to streams is necessary for water quality management. Previous work has shown that estimates of the distribution of water age in streams, the transit time distribution (TTD), can improve prediction of the concentration of conservative tracers (i.e., ones that "follow the water") based on upstream watershed inputs. A major challenge however has been accounting for climate and transport variability when estimating TDDs at the catchment scale. In this regard, Harman (2014, in review) proposed the Omega modeling framework capable of using watershed hydraulic fluxes to approximate the time-varying TTD. The approach was previously applied to the Plynlimon research watershed in Wales to simulate stream concentration dynamics of a conservative tracer (chloride) including 1/f attenuation of the power spectra density. In this study we explore the extent to which TTDs estimated by the Omega model vary with the concentration of non-conservative tracers (i.e., ones whose concentrations are also affected by transformations and interactions with other phases). First we test the hypothesis that the TTD calibrated in Plynlimon can explain a large part of the variation in non-conservative stream water constituents associated with storm flow (acidity, Al, DOC, Fe) and base flow (Ca, Si). While controlling for discharge, we show a correlation between the percentage of water of different ages and constituent concentration. Second, we test the hypothesis that TTDs help explain variation in stream nitrate concentration, which is of particular interest for pollution control but can be highly non-conservative. We compare simulation runs from Plynlimon and the agricultural Choptank watershed in Maryland, USA. Following a top-down approach, we estimate nitrate concentration as if it were a conservative tracer and examine the structure of residuals at different temporal resolutions. Finally, we consider model modifications to

  9. 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.

  10. Population density, biomass, and age-class structure of the invasive clam Corbicula fluminea in rivers of the lower San Joaquin River watershed, California

    USGS Publications Warehouse

    Brown, L.R.; Thompson, J.K.; Higgins, K.; Lucas, L.V.

    2007-01-01

    Corbicula fluminea is well known as an invasive filter-feeding freshwater bivalve with a variety of effects on ecosystem processes. However. C. fluminea has been relatively unstudied in the rivers of the western United States. In June 2003, we sampled C. fluminea at 16 sites in the San Joaquin River watershed of California, which was invaded by C. fluminea in the 1940s. Corbicula fluminea was common in 2 tributaries to the San Joaquin River, reaching densities of 200 clams??m-2, but was rare in the San Joaquin River. Biomass followed a similar pattern. Clams of the same age were shorter in the San Joaquin River than in the tributaries. Distribution of clams was different in the 2 tributaries, but the causes of the difference are unknown. The low density and biomass of clams in the San Joaquin River was likely due to stressful habitat or to water quality, because food was abundant. The success of C. fluminea invasions and subsequent effects on trophic processes likely depends on multiple factors. As C. fluminea continues to expand its range around the world, questions regarding invasion success and effects on ecosystems will become important in a wide array of environmental settings.

  11. A cross-cultural comparison between Spain and the USA: temperament and character distribution by sex and age.

    PubMed

    Al-Halabí, Susana; Herrero, Rocío; Sáiz, Pilar A; García-Portilla, María Paz; Errasti, José M; Corcoran, Paul; Bascarán, María Teresa; Bousoño, Manuel; Lemos, Serafín; Bobes, Julio

    2011-04-30

    The Unified Biosocial Theory of Personality developed by Cloninger has been applied in different cultures. Distribution by age and sex of the Temperament and Character Inventory (TCI) dimensions were assessed cross-culturally for samples in Spain and the USA. Three non-clinical samples were included: i) 404 participants from Asturias (Spain); ii) 240 participants from Burgos (Spain); and iii) 300 adults from St. Louis (USA). Each participant was assessed by means of the TCI. A significant negative correlation between NS and both HA (r=-0.329; P<0.01) and P (r=-0.217; P<0.01) was found in the study sample, as well as significant effects of age in NS, HA, RD, and C for women and in NS and HA for men, and also of sex in HA and RD. Personality dimensions for the two Spanish samples appear to be similar (differences in HA4 and RD) compared to those for the US sample (differences in NS, HA, RD and P). Findings support Cloninger's theory about differences between men and women, but not regarding the intercorrelations between temperament dimensions.

  12. 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.

  13. Quantifying the distribution of nanodiamonds in pre-Younger Dryas to recent age deposits along Bull Creek, Oklahoma Panhandle, USA

    NASA Astrophysics Data System (ADS)

    Bement, Leland C.; Madden, Andrew S.; Carter, Brian J.; Simms, Alexander R.; Swindle, Andrew L.; Alexander, Hanna M.; Fine, Scott; Benamara, Mourad

    2014-02-01

    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.

  14. 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

  15. 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.

  16. EMISSION HEIGHT AND TEMPERATURE DISTRIBUTION OF WHITE-LIGHT EMISSION OBSERVED BY HINODE/SOT FROM THE 2012 JANUARY 27 X-CLASS SOLAR FLARE

    SciTech Connect

    Watanabe, Kyoko; Shimizu, Toshifumi; Masuda, Satoshi; Ichimoto, Kiyoshi; Ohno, Masanori

    2013-10-20

    White-light emissions were observed from an X1.7 class solar flare on 2012 January 27, using three continuum bands (red, green, and blue) of the Solar Optical Telescope on board the Hinode satellite. This event occurred near the solar limb, and so differences in the locations of the various emissions are consistent with differences in heights above the photosphere of the various emission sources. Under this interpretation, our observations are consistent with the white-light emissions occurring at the lowest levels of where the Ca II H emission occurs. Moreover, the centers of the source regions of the red, green, and blue wavelengths of the white-light emissions are significantly displaced from each other, suggesting that those respective emissions are emanating from progressively lower heights in the solar atmosphere. The temperature distribution was also calculated from the white-light data, and we found the lower-layer emission to have a higher temperature. This indicates that high-energy particles penetrated down to near the photosphere, and deposited heat into the ambient lower layers of the atmosphere.

  17. Age- and gender-related changes in the distribution of osteocalcin in the extracellular matrix of normal male and female bone. Possible involvement of osteocalcin in bone remodeling.

    PubMed Central

    Ingram, R T; Park, Y K; Clarke, B L; Fitzpatrick, L A

    1994-01-01

    With increasing age, bone undergoes changes in remodeling that ultimately compromise the structural integrity of the skeleton. The presence of osteocalcin in bone matrix may alter bone remodeling by promoting osteoclast activity. Whether age- and/or gender-related differences exist in the distribution of osteocalcin within individual bone remodeling units is not known. In this study, we determined the immunohistochemical distribution of osteocalcin in the extracellular matrix of iliac crest bone biopsies obtained from normal male and female volunteers, 20-80 yr old. Four different distribution patterns of osteocalcin within individual osteons were arbitrarily defined as types I, II, III, or IV. The frequency of appearance of each osteon type was determined as a percent of the total osteons per histologic section. The proportion of osteons that stained homogeneously throughout the concentric lamellae (type I) decreased in females and males with increasing age. The proportion of osteons that lack osteocalcin in the matrix immediately adjacent to Haversian canals (type III) increased in females and males with age. Osteons staining intensely in the matrix adjacent to Haversian canals (type II) increased in females and was unchanged in aging males. Osteons that contained osteocalcin-positive resting lines (type IV) increased in bone obtained from males with increasing age but were unchanged in females. Sections of bone immunostained for osteopontin (SPP-I), osteonectin, and decorin did not reveal multiple patterns or alterations in staining with gender or increasing age. We suggest that the morphology of individual bone remodeling units is heterogeneous and the particular morphologic pattern of osteocalcin distribution changes with age and gender. These results suggest that differences in the distribution of osteocalcin in bone matrix may be responsible, in part, for the altered remodeling of bone associated with gender and aging. Images PMID:8132785

  18. Age distribution patterns of patients with conventional ductal adenocarcinoma of the pancreas. A single-institution study of 580 cases re-evaluated using current histopathological diagnostic criteria.

    PubMed

    Liszka, Łukasz; Pająk, Jacek; Mrowiec, Sławomir; Zielińska-Pająk, Ewa; Lampe, Paweł; Gołka, Dariusz

    2010-01-01

    There are a few studies concerning epidemiology of pancreatic ductal adenocarcinoma (PDAC) in the Polish population. Analysis of age distribution patterns of patients with different types of cancer may be useful for studying their specific biology. In the present study we aimed to describe age distribution patterns of 580 patients with PDAC diagnosed in one centre during a 25-year period. All the histopathological diagnoses were re-reviewed using current histopathological diagnostic criteria. Age distributions of selected subpopulations of patients (defined based on gender, potential tumour resectability and type of the surgery) were compared using mean values, medians, age frequency density plots and logarithmic plots of age-specific frequencies. The mean and median values of patients' age were 60.8 y and 61.0 y, respectively. Females were approximately 2 y older than males at the time of PDAC diagnosis. Females with non-resectable PDAC were approximately 2 y older than females with resectable tumours. Mean age values of males with non-resectable and resectable PDAC were similar. Patients treated with pancreaticoduodenectomy were approximately 2 y older than patients undergoing other types of resections. Age distribution density plots showed that some subgroups of patients studied were somewhat heterogeneous and might include several yet poorly recognized clinico-pathological entities. Logarithmic plots of age-specific frequencies showed that PDAC epidemiology is in concordance with a multistage theory of carcinogenesis. PDAC is an age-dependent cancer. Single-institutional pathology-oriented cancer epidemiological databases may add some information to population-based cancer registries.

  19. Class network routing

    DOEpatents

    Bhanot, Gyan; Blumrich, Matthias A.; Chen, Dong; Coteus, Paul W.; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Steinmacher-Burow, Burkhard D.; Takken, Todd E.; Vranas, Pavlos M.

    2009-09-08

    Class network routing is implemented in a network such as a computer network comprising a plurality of parallel compute processors at nodes thereof. Class network routing allows a compute processor to broadcast a message to a range (one or more) of other compute processors in the computer network, such as processors in a column or a row. Normally this type of operation requires a separate message to be sent to each processor. With class network routing pursuant to the invention, a single message is sufficient, which generally reduces the total number of messages in the network as well as the latency to do a broadcast. Class network routing is also applied to dense matrix inversion algorithms on distributed memory parallel supercomputers with hardware class function (multicast) capability. This is achieved by exploiting the fact that the communication patterns of dense matrix inversion can be served by hardware class functions, which results in faster execution times.

  20. 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

  1. 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.

  2. Visualizing disease associations: graphic analysis of frequency distributions as a function of age using moving average plots (MAP) with application to Alzheimer's and Parkinson's disease.

    PubMed

    Payami, Haydeh; Kay, Denise M; Zabetian, Cyrus P; Schellenberg, Gerard D; Factor, Stewart A; McCulloch, Colin C

    2010-01-01

    Age-related variation in marker frequency can be a confounder in association studies, leading to both false-positive and false-negative findings and subsequently to inconsistent reproducibility. We have developed a simple method, based on a novel extension of moving average plots (MAP), which allows investigators to inspect the frequency data for hidden age-related variations. MAP uses the standard case-control association data and generates a birds-eye view of the frequency distributions across the age spectrum; a picture in which one can see if, how, and when the marker frequencies in cases differ from that in controls. The marker can be specified as an allele, genotype, haplotype, or environmental factor; and age can be age-at-onset, age when subject was last known to be unaffected, or duration of exposure. Signature patterns that emerge can help distinguish true disease associations from spurious associations due to age effects, age-varying associations from associations that are uniform across all ages, and associations with risk from associations with age-at-onset. Utility of MAP is illustrated by application to genetic and epidemiological association data for Alzheimer's and Parkinson's disease. MAP is intended as a descriptive method, to complement standard statistical techniques. Although originally developed for age patterns, MAP is equally useful for visualizing any quantitative trait.

  3. Class Size.

    ERIC Educational Resources Information Center

    Ellis, Thomas I.

    1985-01-01

    After a brief introduction identifying current issues and trends in research on class size, this brochure reviews five recent studies bearing on the relationship of class size to educational effectiveness. Part 1 is a review of two interrelated and highly controversial "meta-analyses" or statistical integrations of research findings on class size,…

  4. Class Matters

    ERIC Educational Resources Information Center

    Valdata, Patricia

    2005-01-01

    Ever since George Washington opted for the title of president rather than king, Americans have been uncomfortable with the idea of class distinctions. This article presents an interview with Dr. Janet Galligani Casey regarding the idea of class distinctions. Galligani Casey, who grew up in a working-class neighborhood in Somerville, Massachusetts,…

  5. 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.

  6. Levels, tissue distribution, and age-related accumulation of synthetic musk fragrances in Chinese sturgeon (Acipenser sinensis): comparison to organochlorines.

    PubMed

    Wan, Yi; Wei, Qiwei; Hu, Jianying; Jin, Xiaohui; Zhang, Zhaobin; Zhen, Huajun; Liu, Jianyi

    2007-01-15

    Chinese sturgeon (Acipenser sinensis) was listed as a Grade I protected animal in China in 1989, and the observed intersexual phenomenon and sex ratio deviation have suggested that chemicals have posed a risk as environment pollutants. This study analyzed seven musk fragrances in liver, muscle, heart, gonad, stomach, intestines, adipose, gill, pancreas, kidney, gallbladder, and roe from 13 female Chinese sturgeons, and the toxicokinetic behavior of musks were studied and compared with some organochlorines. Of the seven musks, HHCB, AHTN, and musk xylene were detected, and the highest concentrations were observed in adipose tissue: from 33.7 to 62.1 ng/g wet weight (ww), from 1.0 to 5.4 ng/g ww, and from 1.1 to 13 ng/g ww, respectively. Similar to the tissue distribution of DDTs and HCB, musks were detected frequently in high lipid content tissues such as roe, adipose, and liver, suggesting that tissue distribution of musks is controlled by the affinity to lipids. The concentration ratios based on lipid weight between roe and adipose were estimated to be 0.47 for HHCB, 0.58 for AHTN, and 0.51 for musk xylene, and those for the total DDTs and HCB were 0.27 and 0.61, which were relatively low compared with mammals. Relatively high concentrations of p,p'-DDE (68.4-449 ng/g ww) were detected in 10 of total 11 samples, which would cause the feminization of Chinese sturgeons during embryonic development. It was found that lipid-corrected concentrations of HHCB, AHTN, p,p'-DDE, and p,p'-DDD increased with age in female sturgeon, of which the trends were similar to those in fishes and different from those in mammals.

  7. Distribution and partial characterization of seasonally expressed proteins in different aged shoots and roots of 'Loring' peach (Prunus persica).

    PubMed

    Wisniewski, Michael; Bassett, Carole; Arora, Rajeev

    2004-03-01

    During autumnal leaf senescence, leaf nitrogen in deciduous trees is translocated to storage sites, especially bark and xylem tissues. Proteins that accumulate in large amounts in bark and xylem in winter and are absent from these organs in summer are called storage proteins, and are believed to be vehicles for storing nitrogen reserves. These reserves are important for spring growth and help trees tolerate or recover from both abiotic and biotic stresses. Based on seasonal patterns of accumulation, we previously identified three storage proteins with molecular masses of 60, 19 and 16 kDa in bark tissues of 'Loring' peach (Prunus persica (L.) Batsch). To characterize the distribution of these proteins in different-aged tissues and to determine if they have any function other than nitrogen storage, we examined their seasonal distribution in bark tissues of current-year and 1-year-old shoots, scaffold branches, main trunks and 4-5-year-old roots of 'Loring' peach. Verification of protein identity was based on molecular mass and reactions with antibodies directed against each specific protein. Protein distribution was variable. For all three proteins, the greatest amount was present in mid-winter in current-year and 1-year-old shoots. These tissues also showed the greatest seasonal variation in the amount of protein present. The 16 kDa protein was present only in the youngest shoots, whereas the 19 kDa protein was present in all tissues examined. The 60 kDa protein was absent in root tissue. The amino acid composition and sequence of each protein were determined. The 60 kDa protein was identified as a dehydrin, and the 19 kDa protein appeared to be related to a family of allergen proteins in Rosaceous plants, some members of which are associated with pathogenesis-related proteins. The amino acid sequence of the 16 kDa protein appeared to have no homology with any proteins in the SwissProt database. Therefore, it is likely that the 16 kDa protein, in a strict sense, is

  8. Cloning, characterization and tissue distribution of a pi-class glutathione S-transferase from clam (Venerupis philippinarum): Response to benzo[alpha]pyrene exposure.

    PubMed

    Xu, Chaoqun; Pan, Luqing; Liu, Na; Wang, Lin; Miao, Jingjing

    2010-08-01

    Glutathione S-transferases (GSTs) are phase II enzymes involved in major detoxification reactions of xenobiotics in many organisms. In this study, a full-length cDNA of GST-pi was cloned from the gill of Venerupis philippinarum by rapid amplification of cDNA ends (RACE) method for the first time. The full-length cDNA of V. philippinarum GST-pi (denoted as VpGSTp) was 1142bp, with a 5' untranslated region (UTR) of 87bp, a 3' UTR of 438bp, and an open reading frame (ORF) of 618bp encoding a protein of 205 amino acid residues with an estimated molecular mass of 23.9kDa and an predicted isoelectric point (pI) of 7.9. The comparison of the deduced amino acid sequences with GSTs from other species showed that the enzyme belongs to the pi-class, and the amino acids defining the binding sites of glutathione (G-site) and for xenobiotic substrates (H-site) were highly conserved. Tissue distribution analysis of the VpGSTp mRNA revealed that the GST-pi expression level was observed higher in gill, adductor muscle, mantle and foot while lower in digestive gland. Using quantitative real-time PCR, the dose- and time-related effects of benzo[alpha]pyrene (B[alpha]P) on VpGSTp mRNA expression were investigated in gills and digestive gland. The results showed that a time-dependant increase in the expression of VpGSTp was induced by B[alpha]P and appeared a good linear relationship with B[alpha]P concentrations. All these results suggested that GST-pi in bivalve had an antioxidant role and VpGSTp expression may be a useful biomarker candidate for monitoring environmental contaminants such as PAHs.

  9. 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.

  10. SURVEY OF THE STEROL COMPOSITION OF THE MARINE DINOFLAGELLATES KARENIA BREVIS, KARENIA MIKIMOTOI, AND KARLODINIUM MICRUM: DISTRIBUTION OF STEROLS WITHIN OTHER MEMBERS OF THE CLASS DINOPHYCEAE

    EPA Science Inventory

    The sterol composition of different marine microalgae was examined to determine the utility of sterols as biomarkers to distinguish members of various algal classes. For example, members of the class Dinophyceae possess certain 4-methyl sterols, such as dinosterol, which are rare...

  11. Genetic differentiation in populations with different classes of individuals.

    PubMed

    Rousset, F

    1999-06-01

    I formulate and analyse a model of population structure with different classes of individuals. These different classes may be age classes, other demographic classes, or different types of habitats homogeneously distributed over a geographical area. The value of population differentiation under an island model of dispersal and the increase of differentiation with geographical distance in one- and two-dimensional "isolation by distance" models are then obtained for a generalization of the FST measure of population structure, as a function of "effective" mutation, migration, and population size parameters. The relevant effective subpopulation size is related to the "mutation effective population size" of a single isolated subpopulation and, in models of age-structured populations, to the inbreeding effective population size.

  12. Age- and direction-related adaptations of lumbar vertebral trabecular bone with respect to apparent stiffness and tissue level stress distribution

    NASA Astrophysics Data System (ADS)

    Gong, He; Fan, Yubo; Zhang, Ming; Qin, Ling

    2009-02-01

    The objective of this study was to study the age-related adaptation of lumbar vertebral trabecular bone at the apparent level, as well as the tissue level in three orthogonal directions. Ninety trabecular specimens were obtained from six normal L4 vertebral bodies of six male cadavers in two age groups, three aged 62 years and three aged 69 years, and were scanned using a high-resolution micro-computed tomography (micro-CT) system, then converted to micro-finite element models to do micro-finite element analyses. The relationship between apparent stiffness and bone volume fraction, and the tissue level von Mises stress distribution for each trabecular specimen when compressed separately in the longitudinal direction, medial-lateral and anterior-posterior directions (transverse directions) were derived and compared between two age groups. The results showed that at the apparent level, trabecular bones from 69-year group had stiffer bone structure relative to their volume fractions in all three directions, and in both age groups, changes in bone volume fraction could explain more variations in apparent stiffness in the longitudinal direction than the transverse directions; at the tissue level, aging had little effect on the tissue von Mises stress distributions for the compressions in all the three directions. The novelty of the present study was that it provided quantitative assessments on the age and direction-related adaptation of Chinese male lumbar vertebral trabecular bone from two different levels: stiffness at the apparent level and stress distribution at the tissue level. It may help to understand the failure mechanisms and fracture risks of vertebral body associated with aging and direction for the prevention of fracture risks in elder individuals.

  13. 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

  14. ESTROGEN AND AGING AFFECT THE SYNAPTIC DISTRIBUTION OF ESTROGEN RECEPTOR BETA-IMMUNOREACTIVITY IN THE CA1 REGION OF FEMALE RAT HIPPOCAMPUS

    PubMed Central

    Waters, Elizabeth M.; Yildirim, Murat; Janssen, William G.M.; Lou, W.Y. Wendy; McEwen, Bruce S.; Morrison, John H.; Milner, Teresa A.

    2010-01-01

    Estradiol (E) mediates increased synaptogenesis in the hippocampal CA1 stratum radiatum (sr) and enhances memory in young and some aged female rats, depending on dose and age. Young females rats express more estrogen receptor α (ERα) immunolabeling in CA1sr spine synapse complexes than aged rats and ERα regulation is E sensitive in young but not aged rats. The current study examined whether estrogen receptor β (ERβ) expression in spine synapse complexes may be altered by age or E treatment. Young (3–4 months) and aged (22–23 months) female rats were ovariectomized 7 days prior to implantation of silastic capsules containing either vehicle (cholesterol) or E (10% in cholesterol) for 2 days. ERβ immunoreactivity (ir) in CA1sr was quantitatively analyzed using post-embedding electron microscopy. ERβ-ir was more prominent postsynaptically than presynaptically and both age and E treatment affected its synaptic distribution. While age decreased the spine synaptic complex localization of ERβ-ir (i.e., within 60 nm of the pre- and post-synaptic membranes), E treatment increased synaptic ERβ in both young and aged rats. In addition, the E treatment, but not age, increased dendritic shaft labeling. This data demonstrates that like ERα the levels of ERβ-ir decrease in CA1 axospinous synapses with age, however, unlike ERα the levels of ERβ-ir increase in these synapses in both young and aged rats in response to E. This suggests that synaptic ERβ may be a more responsive target to E, particularly in aged females. PMID:20875808

  15. [Relation between cardiorespiratory indicators, blood lipids, and the amount and distribution of adipose tissue in middle-aged men].

    PubMed

    Parízková, J; Vĕtvicka, J; Pousek, L; Liska, O

    1995-06-28

    BACKGROUND. In middle-aged and elderly men the cardiovascular mortality in this country is still relatively high. The objective of the presented work was therefore the validation of simple parameters of fat deposition as a risk factor in order to select subjects at risk where preventive measures are called for. METHODS AND RESULTS. In 68 men aged 43.8 +/- 7.4 years from a sample of managers of a Prague bank the case-history we evaluated, as well as a basic physical examination, a loading test on a bicycle ergometer (performance evaluated in W/kg body weight or lean body mass) and ECG; serum lipids were examined (total and HDL-cholesterol, triacyglycerols), the body mass index (BMI), the ratio of depot fat (by evaluation of 10 skinfolds measured by means of a caliper) and the distribution of body fat (indices relating either only the subscapular and tricipital skinfold or all skinfolds on the trunk to all skinfolds on the extremities, and the waist/hip ratio). The basic physical examination did not reveal any serious acute diseases. Mean BMI values (26.7 +/- 3.4 kg/m2) and body fat ratio (20.8 +/- 4.2%) were higher than standard values. 24.1% of the men were obese, the W/H ratio was 0.9 +/- 0.1 but this index, similarly as the other mentioned indices, were elevated, indicating risk. The mean values of the heart rate and blood pressure at rest and after a load were normal, however 11.5% of the men had an elevated diastolic pressure after a load and a similar percentage of men manifested during a load certain signs of myocardial ischaemia. The prevalence of hypertension according to WHO criteria was 9.6%. On average, however, the physical performance (W/kg of the total body weight or lean body mass) was 108% of the Czech standard assessed previously within the framework of the International Biological Programme. The total cholesterol was 5.35 +/- 1.04, HDL 1.11 +/- 0.19, total triacylglycerols 1.81 +/- 0.77 mmol/l. The ratio of total and HDL cholesterol was 4.9 +/- 1

  16. 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

    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

  17. 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

  18. 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

    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

  19. A Modern Analog to the Depositional Age Problem: Zircon and Apatite Fission Track and U-Pb Age Distributions by LA-ICP-MS

    NASA Astrophysics Data System (ADS)

    Donelick, H. M.; Donelick, M. B.; Donelick, R. A.

    2012-12-01

    Sand from three river systems in North Idaho (Snake River near Lewiston, Clearwater River near Lewiston and the Salmon River near White Bird) and two regional ash fall events (Mt. Mazama and Mt. St. Helens) were collected for zircon U-Pb detrital age analysis. Up to 120 grains of zircon per sample were ablated using a Resonetics M-50 193 nm ArF Excimer laser ablation (LA) system and the Pb, Th, and U isotopic signals were quantified using an Agilent 7700x quadrupole inductively coupled plasma-mass spectrometer (ICP-MS). Isotopic signals for major, minor, and trace elements, including all REEs, were also monitored. The youngest zircon U-Pb ages from the river samples were approximately 44 Ma; Cenozoic Idaho Batholith and Precambrian Belt Supergroup ages were well represented. Significant common Pb contamination of the Clearwater River sample (e.g., placer native Cu was observed in the sample) precluded detailed analysis of the zircon U-Pb ages but no interpretable ages <44 Ma were observed. Interestingly, not one of the river samples yielded zircon U-Pb ages near 0 Ma, despite all three catchment areas having received significant ash from Mt. St. Helens in 1980, and Mount Mazama 7,700 years ago, and no doubt other events during the Quaternary. Work currently in progress seeks to address bias against near 0 Ma ages in the catchment areas due to: a) small, local ash fall grain sizes and b) overwhelming number of older grains relative to the ash fall grains. Data from Mt. St. Helens ash from several localities near the mountain (Toutle River and Maple Flats, WA) and several far from the mountain (Spokane, WA; Princeton, ID; Kalispell, MT) and Mt. Mazama ash fall deposits near Lewiston, ID and Spokane, WA will be presented to address these possibilities. Additionally, fission track and U-Pb ages from apatites collected from these river and ash fall samples will also be shown to help constrain the problem.

  20. 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

  1. 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.

  2. MitoTimer probe reveals the impact of autophagy, fusion, and motility on subcellular distribution of young and old mitochondrial protein and on relative mitochondrial protein age

    PubMed Central

    Ferree, Andrew W; Trudeau, Kyle; Zik, Eden; Benador, Ilan Y; Twig, Gilad; Gottlieb, Roberta A; Shirihai, Orian S

    2013-01-01

    To study mitochondrial protein age dynamics, we targeted a time-sensitive fluorescent protein, MitoTimer, to the mitochondrial matrix. Mitochondrial age was revealed by the integrated portions of young (green) and old (red) MitoTimer protein. Mitochondrial protein age was dependent on turnover rates as pulsed synthesis, decreased import, or autophagic inhibition all increased the proportion of aged MitoTimer protein. Mitochondrial fusion promotes the distribution of young mitochondrial protein across the mitochondrial network as cells lacking essential fusion genes Mfn1 and Mfn2 displayed increased heterogeneity in mitochondrial protein age. Experiments in hippocampal neurons illustrate that the distribution of older and younger mitochondrial protein within the cell is determined by subcellular spatial organization and compartmentalization of mitochondria into neurites and soma. This effect was altered by overexpression of mitochondrial transport protein, RHOT1/MIRO1. Collectively our data show that distribution of young and old protein in the mitochondrial network is dependent on turnover, fusion, and transport. PMID:24149000

  3. Mortality estimates from ovarian age distributions of the tsetse fly Glossina pallidipes Austen sampled in Zimbabwe suggest the need for new analytical approaches

    PubMed Central

    HARGROVE, JOHN W.; ACKLEY, SARAH F.

    2016-01-01

    Mortality estimates are central to understanding tsetse fly population dynamics, but are difficult to acquire from wild populations. They can be obtained from age distribution data but, with limited data, it is unclear whether the assumptions required to make the estimates are satisfied and, if not, how violations affect the estimates. We evaluate the assumptions required for existing mortality estimation techniques using long-term longitudinal ovarian dissection data from 144,106 female tsetse, Glossina pallidipes Austen, captured in Zimbabwe between 1988 and 1999. At the end of the hot dry season each year, mean ovarian ages peaked, and maximum likelihood mortality estimates declined to low levels, contrary to mark-recapture estimates, suggesting violations of the assumptions underlying the estimation technique. We demonstrate that age distributions are seldom stable for G. pallidipes at our study site, and hypothesize that this is a consequence of a disproportionate increase in the mortality of pupae and young adults at the hottest times of the year. Assumptions of age-independent mortality and capture probability are also violated, the latter bias varying with capture method and with pregnancy and nutritional status. As a consequence, mortality estimates obtained from ovarian dissection data are unreliable. To overcome these problems we suggest simulating female tsetse populations, using dynamical modelling techniques that make no assumptions about the stability of the age distribution. PMID:25804211

  4. 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

  5. A comparison of the age distributions in the dengue hemorrhagic fever epidemics in Santiago de Cuba (1997) and Thailand (1998).

    PubMed

    Pongsumpun, P; Yoksan, S; Tan, I M

    2002-06-01

    The age profiles of the infected populations of two dengue hemorrhagic fever (DHF) epidemics, the 1997 epidemic, in Santiago de Cuba and the 1998 epidemic in Thailand, are compared. Using an age-structured model of disease transmission, the dependence of the forces of infection on age was determined for each epidemic. The difference in the behavior of the two epidemics and the role of primary and secondary infection in the development of DHF are discussed.

  6. Distribution patterns during winter and fidelity to wintering areas of American black ducks

    USGS Publications Warehouse

    Diefenbach, D.R.; Nichols, J.D.; Hines, J.E.

    1988-01-01

    The distribution patterns during winter of American black ducks were compared among age-sex classes using band recivery data. In addition, fidelity to wintering areas was compared between sexes and between coastal and inland wintering sites.

  7. The Effects of Maxillary Protraction with or without Rapid Maxillary Expansion and Age Factors in Treating Class III Malocclusion: A Meta-Analysis

    PubMed Central

    Zhang, Wei; Qu, Hong-Chen; Yu, Mo; Zhang, Yang

    2015-01-01

    We conducted a comprehensive meta-analysis of 12 studies to examine whether maxillary protraction face mask associated with rapid maxillary expansion (FM/RME) could be an effective treatment for Class III malocclusion and to evaluate the effect of timing on treatment response. Patients with a maxillary deficiency who were treated with FM with or without RME were compared with those who had an untreated Class III malocclusion. In both treatment groups, forward displacement of the maxilla and skeletal changes were found to be statistically significant. In addition, posterior rotation of the mandible and increased facial height were more evident in the FM group compared with the control group. However, no significant differences were observed between the early treatment groups and late treatment groups. The results indicated that both FM/RME and FM therapy produced favorable skeletal changes for correcting anterior crossbite, and the curative time was not affected by the presence of deciduous teeth, early mixed dentition or late mixed dentition in the patient. PMID:26068221

  8. 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.

  9. Student Self-Reports of Metacognitive Activity in Physical Education Classes. Age-Group Differences and the Effect of Goal Orientations and Perceived Motivational Climate

    ERIC Educational Resources Information Center

    Theodosiou, Argiris; Mantis, Konstantinos; Papaioannou, Athanasios

    2008-01-01

    The present study examined age-group differences in students' self-reports of metacognitive activity in physical education settings. Five hundred and ten students of public elementary, junior and senior high school provided self-reports concerning the metacognitive processes they use during physical education lessons, their goal orientations and…

  10. Teaching Mathematics in Rudolf Steiner Schools for Classes I-VIII. How To Become Imaginative and Holistic. Volume 1, Up to Age 14.

    ERIC Educational Resources Information Center

    Jarman, Ron

    This book aims to present helpful, practical ideas and suggestions for mathematics teaching. Focus is on how teaching can be developed in a Rudolf Steiner (Waldorf) School and includes treatment of mathematical topics applicable to the 7-14 age group. Suggestions for curriculum and examples for children to work on are presented with a very wide…

  11. Age Distribution and Determinants of Invasive Cervical Cancer in a “Screen-and-Treat” Program Integrated With HIV/AIDS Care in Zambia

    PubMed Central

    Kapambwe, Sharon; Sahasrabuddhe, Vikrant V.; Blevins, Meridith; Mwanahamuntu, Mulindi H.; Mudenda, Victor; Shepherd, Bryan E.; Chibwesha, Carla J.; Pfaendler, Krista S.; Hicks, Michael L.; Vermund, Sten H.; Stringer, Jeffrey S. A.; Parham, Groesbeck P.

    2016-01-01

    Background Cervical cancer screening efforts linked to HIV/ AIDS care programs are being expanded across sub-Saharan Africa. Evidence on the age distribution and determinants of invasive cervical cancer (ICC) cases detected in such programs is limited. Methods We analyzed program operations data from the Cervical Cancer Prevention Program in Zambia, the largest public sector programs of its kind in sub-Saharan Africa. We examined age distribution patterns by HIV serostatus of histologically confirmed ICC cases and used multivariable logistic regression to evaluate independent risk factors for ICC among younger (≤35 years) and older (>35 years) women. Results Between January 2006 and April 2010, of 48,626 women undergoing screening, 571 (1.2%) were diagnosed with ICC, including 262 (46%) HIV seropositive (median age: 35 years), 131 (23%) HIV seronegative (median age: 40 years), and 178 (31%) of unknown HIV serostatus (median age: 38 years). Among younger (≤35 years) women, being HIV seropositive was associated with a 4-fold higher risk of ICC [adjusted odds ratio = 4.1 (95% confidence interval: 2.8, 5.9)] than being HIV seronegative. The risk of ICC increased with increasing age among HIV-seronegative women and women with unknown HIV serostatus, but among HIV-seropositive women, the risk peaked around age 35 and non-significantly declined with increasing ages. Other factors related to ICC included being married (vs. being unmarried/widowed) in both younger and older women, and with having 2+ (vs. ≤1) lifetime sexual partners among younger women. Conclusions HIV infection seems to have increased the risk of cervical cancer among younger women in Zambia, pointing to the urgent need for expanding targeted screening interventions. PMID:26322673

  12. Social Occupational Classes and Higher-Education Opportunities in Contemporary China: A Study on the Distribution of a Scarce Social Capital

    ERIC Educational Resources Information Center

    Zhang, Yulin; Liu, Baojun

    2006-01-01

    Based on the several surveys conducted since the 1990s onward, this paper aims to demonstrate that in terms of the access to higher education, social class differentiation is far starker than that of urban/rural income in contemporary China. According to the investigation that focused on students enrolled in 37 universities, the chance of farmers…

  13. Evaluation of an Education, Restraint Distribution, and Fitting Program to Promote Correct Use of Age-Appropriate Child Restraints for Children Aged 3 to 5 Years: A Cluster Randomized Trial

    PubMed Central

    Hunter, Kate; Brown, Julie; Simpson, Judy M.; Bilston, Lynne E.; Elliott, Maureen; Stevenson, Mark; Ivers, Rebecca Q.

    2012-01-01

    Objectives. We evaluated an education, distribution, and fitting program for increasing age-appropriate and correct child restraint use. Methods. We performed a cluster randomized trial involving 28 early childhood education centers in low socioeconomic status areas in Sydney, Australia. The main outcome was optimal restraint use defined as age-appropriate restraints, installed into the vehicle correctly and used correctly. Results. One service withdrew after randomization, so data are presented for 689 child passengers, aged 3 to 5 years, from 27 centers. More children attending intervention centers were optimally restrained (43% vs 31%; P = .01; allowing for clustering). More 3-year-olds were using forward-facing seats rather than booster seats, more 4- to 5-year-olds were using booster seats instead of seat belts alone, and there were fewer errors in use at intervention centers. Among non–English-speaking families, more children attending intervention centers were optimally restrained (43% vs 17%; P = .002; allowing for clustering). Conclusions. The program increased use of age-appropriate restraints and correct use of restraints, which translates to improved crash injury protection. Multifaceted education, seat distribution, and fitting enhanced legislation effects, and the effect size was larger in non–English-speaking families. PMID:23078492

  14. The Impact of Cooking Classes on Food-Related Preferences, Attitudes, and Behaviors of School-Aged Children: A Systematic Review of the Evidence, 2003–2014

    PubMed Central

    Perdue, Laura; Ambroz, Teresa; Boucher, Jackie L.

    2014-01-01

    Introduction Cooking programs have been used to promote healthful eating among people of all ages. This review assesses the evidence on childhood cooking programs and their association with changes in food-related preferences, attitudes, and behaviors of school-aged children. Methods We systematically searched PubMed, Ovid-Medline, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases. We included primary research articles that involved cooking education programs for children and searched reference lists for eligible articles. Studies considered for review contained a hands-on cooking intervention; had participants aged 5 to 12 years; were published in a peer-reviewed journal on or after January 1, 2003; and were written in English. We used the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies to rate the strength of each article and assess bias. The following information was extracted from each study: study design, sample size, location, duration, intervention components, data collection methods, and outcomes. Results Eight studies met the inclusion criteria and used cooking education to influence children’s food-related preferences, attitudes, and behaviors. Programs varied in duration, evaluation methods, and outcomes of interest. Self-reported food preparation skills, dietary intake, cooking confidence, fruit and vegetable preferences, attitudes toward food and cooking, and food-related knowledge were among the outcomes measured. Program exposure ranged from 2 sessions to regular instruction over 2 years, and the effect of cooking programs on children’s food-related preferences, attitudes, and behaviors varied among the reviewed studies. Conclusions Findings suggest that cooking programs may positively influence children’s food-related preferences, attitudes, and behaviors. However, because study measurements varied widely, determining best practices was difficult. Further research is

  15. Effects of topography, soil type and forest age on the frequency and size distribution of canopy gap disturbances in a tropical forest

    NASA Astrophysics Data System (ADS)

    Lobo, E.; Dalling, J. W.

    2013-11-01

    Treefall gaps are the major source of disturbance in most tropical forests. The frequency and size of these gaps have important implications for forest ecosystem processes as they can influence the functional trait distribution of tree communities, stand-level aboveground biomass and productivity. However, we still know little about the relative importance of environmental drivers of gap disturbance regimes because existing studies vary greatly in criteria used for defining gaps, in the spatial extent of the study area, and the spatial resolution of canopy height measurements. Here we use lidar (light detecting and ranging) to explore how forest age, topography and soil type affect canopy disturbance patterns across a 1500 ha tropical forest landscape in central Panama. We characterize disturbance based on the frequency distribution of gap sizes (the "gap size distribution"), and the area of the forest affected by gaps (the "gap area fraction"). We found that slope and forest age had significant effects on the gap size distribution, with a higher frequency of large gaps associated with old-growth forests and more gentle slopes. Slope and forest age had similar effects on the gap area fraction, however gap area fraction was also affected by soil type and by aspect. We conclude that variation in disturbance patterns across the landscape can be linked to factors that act at the fine scale (such as aspect or slope), and factors that show heterogeneity at coarser scales (such as forest age or soil type). Awareness of the role of different environmental factors influencing gap formation can help scale up the impacts of canopy disturbance on forest communities measured at the plot scale to landscape and regional scales.

  16. Effects of topography, soil type and forest age on the frequency and size distribution of canopy gap disturbances in a tropical forest

    NASA Astrophysics Data System (ADS)

    Lobo, E.; Dalling, J. W.

    2013-04-01

    Treefall gaps are the major source of disturbance in most tropical forests. The frequency and size of these gaps have important implications for forest ecosystem processes as they can influence the functional trait distribution of tree communities, stand-level above-ground biomass and productivity. However, we still know little about the relative importance of environmental drivers of gap disturbance regimes because existing studies vary greatly in criteria used for defining gaps, in the spatial extent of the study area, and the spatial resolution of canopy height measurements. Here we use LiDAR (light detecting and ranging) to explore how forest age, topography and soil type affect canopy disturbance patterns across a 1500 ha tropical forest landscape in central Panama. We characterize disturbance based on the frequency distribution of gap sizes (the "gap size distribution"), and the area of the forest affected by gaps (the "gap area fraction"). We found that slope and forest age had significant effects on the gap size distribution, with a higher frequency of large gaps associated with old-growth forests and more gentle slopes. Slope and forest age had similar effects on the gap area fraction, however gap area fraction was also affected by soil type and by aspect. We conclude that variation in disturbance patterns across the landscape can be linked to factors that act at the fine scale (such as aspect or slope), and factors that show heterogeneity at coarser scales (such as forest age or soil type). Awareness of the role of different environmental factors influencing gap formation can help scale-up the impacts of canopy disturbance on forest communities measured at the plot scale to landscape and regional scales.

  17. The Distribution of SIgA and IgG Antibody-Secreting Cells in the Small Intestine of Bactrian Camels (Camelus bactrianus) of Different Ages

    PubMed Central

    Zhang, Wang-Dong; Wang, Wen-Hui; Jia, Shuai

    2016-01-01

    Secretory immunoglobulin A (SIgA) and immunoglobulin G (IgG) antibody-secreting cells (ASCs) are two important cell types in the mucosal immune system. This study aimed to explore the distribution of these ASC populations in the small intestine of Bactrian camels of different ages. Twenty-four Alashan Bactrian camels were divided into the following four age groups: young (1–2 years), pubertal (3–5 years), middle-aged (6–16 years) and old (17–20 years). SIgA and IgG ASCs in the intestinal mucosa lamina propria (LP) were observed and analyzed using immunohistochemcal techniques. The results from all age groups show that both SIgA and IgG ASCs were diffusely distributed in the intestinal LP, and some cells aggregated around the crypts. Moreover, the densities of the two ASC populations gradually increased from the duodenum to the jejunum and then decreased in the ileum. Meanwhile, there were more SIgA ASCs than IgG ASCs in the duodenum, jejunum, and ileum, and these differences were significant in the young and pubertal groups (P<0.05). In addition, the SIgA and IgG ASC densities increased from the young to the pubertal period, peaked at puberty, and then gradually decreased with age. The results demonstrate that the SIgA and IgG ASC distributions help to form two immunoglobulin barriers in the intestinal mucosa to provide full protection, helping to maintain homeostasis. These findings also underscore the importance of researching the development and degeneration of intestinal mucosal immunity in Bactrian camels. PMID:27249417

  18. Age classes and sex differences in the skull of the Mediterranean monk seal, Monachus monachus (Hermann, 1779). A study based on bone shape and density.

    PubMed

    Mo, Giulia; Zotti, Alessandro; Agnesi, Sabrina; Finoia, Maria Grazia; Bernardini, Daniele; Cozzi, Bruno

    2009-04-01

    This study analyzes morphometrically 17 skulls of the Mediterranean monk seal Monachus monachus housed in different Italian Museums and collections. We considered several morphometric variables (31 linear, 1 volumetric and 1 surface area measurements). In addition, we identified, measured and compared two nonmorphometric variables, namely, the bone densities of selected areas obtained using a dual-energy X-ray absorptiometry (DXA) device. The high correlation coefficient of all variables indicated continuous growth with the onset of age. The ranking of the hierarchical cluster analysis identified the presence of three main groups containing individuals of similar sizes: lactating pups and yearlings; subadult individuals and adult females; and adult males. Smaller groups were identified within these clusters, and their respective allocations into two subgroups were argued on the basis of skull development and other factors. The discriminant analysis of the three main groups indicated a discriminant diagnostic key, based on condilobasilar length (CBlr-L); maximum mandibular branch height (MB-H); and surface area of the bulla tympanica. The proposed diagnostic key is useful to classify monk seal skulls of unidentified age and sex. The data reported here suggest that in this species certain adult skull growth features (enhanced tympanic bullae surface area extension, occipital bone density) are sexually dimorphic and possibly related to specific anatomical functions. These functions may include an enhanced auditory capacity; an increased development of the cranial musculature capable of supporting a large skull and guaranteeing the mandibular strength necessary for mastication; and male to male social interactions. PMID:19301280

  19. 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. PMID:27069502

  20. 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

  1. 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.

  2. EFFECTS OF ESTROGEN AND AGING ON THE SYNAPTIC DISTRIBUTION OF PHOSPHORYLATED AKT-IMMUNOREACTIVITY IN THE CA1 REGION OF THE FEMALE RAT HIPPOCAMPUS

    PubMed Central

    Yildirim, Murat; Janssen, William G.M.; Lou, W.Y. Wendy; Akama, Keith T.; McEwen, Bruce S.; Milner, Teresa A.; Morrison, John H.

    2013-01-01

    The estrogen 17β-estradiol (E) increases the axospinous synaptic density and plasticity in the hippocampal CA1 region of young female rats but fails to do so in aged female rats. This E stimulus on synaptic plasticity is associated with the phosphorylation-dependent activation of Akt kinase. Our previous findings demonstrated that increased estrogen levels subsequently increase phosphorylated Akt (pAkt)-immunoreactivity (-IR) within the dendritic shafts and spines of pyramidal neurons in young female rats. Therefore, because Akt can promote cell survival and growth, we tested the hypothesis that the less plastic synapses of aged female rats would contain less E-stimulated pAkt-IR. Here, young (3-4 months) and aged (22-23 months) female rats were ovariectomized seven days prior to a 48-hour administration of either vehicle or E. The pAkt-IR synaptic distribution was then analyzed using post-embedding electron microscopy. In both young and aged rats, pAkt-IR was found in dendritic spines and terminals, and pAkt-IR was particularly abundant at the post-synaptic density. Quantitative analyses revealed that the percentage of pAkt-labeled synapses was significantly greater in young rats compared to aged rats. Nonetheless, E treatment significantly increased pAkt-IR in pre- and post-synaptic profiles of both young and aged rats, although the stimulus in young rats was notably more widespread. These data support the evidence that hormone-activated signaling associated with cell growth and survival is diminished in the aged brain. However, the observation that E can still increase pAkt-IR in aged synapses presents this signaling component as a candidate target for hormone replacement therapies. PMID:20709039

  3. Using the overdispersed exponential family to estimate the distribution of usual daily intakes of people aged between 18 and 28 in Taiwan.

    PubMed

    Chang, H Y; Suchindran, C M; Pan, W H

    2001-08-15

    Assessment of usual dietary intake of a population is essential to understand the nutrition status of the population. Methods like 24-hour dietary recall and food records are commonly used for this task. However, within-individual variation exists in the food record data. Methods considering measurement errors have been used to evaluate the association between nutrient intakes and diseases. Few have been devoted to estimating the distribution of usual daily intakes. This paper proposes applying the formulation of the overdispersed exponential family to estimate the distribution of usual nutrient intake and applies the adjustments developed by Liu to reduce the variance of the distribution. The proposed method has the advantages of working on the original scale of data and implementation convenience. The adjustment of the variance is carried out by dividing the variance into within-individual variance and among-individual variance. The adjusted variance, then, is used to estimate the distribution of the usual daily intake. Sampling weights are considered in all the steps, except the estimation of the ratio of within to among variance. The data for this study are from the Nutritional and Health Survey in Taiwan conducted between 1993 and 1996 (NAHSIT, 1993-1996). An independent external set of data for people aged between 18 and 28 years (49 males and 20 females) is used to estimate the ratio of within to among individual variance. Due to the availability of data in estimating the ratio of within to among individual variance, 430 males and 422 females in the NAHSIT sample are used to estimate the distribution of usual daily intakes for people aged between 18 and 28 in Taiwan. The distribution also allows us to estimate the proportion of people who do not meet the recommended daily nutrient allowance (RDNA). The results show that the intakes of calcium and vitamin E of this group of people fall far below RDNA. PMID:11468767

  4. 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

  5. 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 ...

  6. 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.

  7. Statistical Descriptors of School Classes

    ERIC Educational Resources Information Center

    Lohnes, Paul R.

    1972-01-01

    It may be useful in evaluation research to employ the class as the unit of analysis, assessing its syntality by a vector of distribution cumulants or indices for each of several input tests administered. (Author)

  8. An objective method to determine the probability distribution of the minimum apparent age of a sample of radio-isotopic dates

    NASA Astrophysics Data System (ADS)

    Ickert, R. B.; Mundil, R.

    2012-12-01

    Dateable minerals (especially zircon U-Pb) that crystallized at high temperatures but have been redeposited, pose both unique opportunities and challenges for geochronology. Although they have the potential to provide useful information on the depositional age of their host rocks, their relationship to the host is not always well constrained. For example, primary volcanic deposits will often have a lag time (time between eruption and deposition) that is smaller than can be resolved using radiometric techniques, and the age of eruption and of deposition will be coincident within uncertainty. Alternatively, ordinary clastic sedimentary rocks will usually have a long and variable lag time, even for the youngest minerals. Intermediate cases, for example moderately reworked volcanogenic material, will have a short, but unknown lag time. A compounding problem with U-Pb zircon is that the residence time of crystals in their host magma chamber (time between crystallization and eruption) can be high and is variable, even within the products of a single eruption. In cases where the lag and/or residence time suspected to be large relative to the precision of the date, a common objective is to determine the minimum age of a sample of dates, in order to constrain the maximum age of the deposition of the host rock. However, both the extraction of that age as well as assignment of a meaningful uncertainty is not straightforward. A number of ad hoc techniques have been employed in the literature, which may be appropriate for particular data sets or specific problems, but may yield biased or misleading results. Ludwig (2012) has developed an objective, statistically justified method for the determination of the distribution of the minimum age, but it has not been widely adopted. Here we extend this algorithm with a bootstrap (which can show the effect - if any - of the sampling distribution itself). This method has a number of desirable characteristics: It can incorporate all data

  9. Class Trash.

    ERIC Educational Resources Information Center

    Chemecology, 1992

    1992-01-01

    Presents a classroom activity in which students calculate the amount and types of trash thrown out by their class at school to investigate how much trash is generated, where it goes, and speculate about alternatives. Students need to be familiar with the concepts of weight, volume, and numbers. (MCO)

  10. 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. PMID:23676481

  11. 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.

  12. Distribution of the HLA class I allele in chronic hepatitis C and its association with serum ALT level in chronic hepatitis C.

    PubMed

    Kondo, Yasuteru; Kobayashi, Koju; Kobayashi, Tomoo; Shiina, Masaaki; Ueno, Yoshiyuki; Satoh, Takaomi; Shimosegawa, Tooru

    2003-10-01

    An essential process for resolution of viral infections is the efficient recognition and elimination of intracellular virus. Recognition of viral antigens in the form of short peptides associated with HLA class I molecule is a major task of CD8+ cytotoxic T lymphocytes. In this study, we have evaluated the frequency of the HLA class I alleles in patients with chronic hepatitis C. HLA-B51, -B52, -B55, -B56, -B61, B70, -Cw1, -Cw3, and -Cw4 are less frequent in patients with chronic hepatitis C than in Japanese individuals. The frequency of HLA-A2 is slightly lower in the patients but tends to be higher in patients with normal alanine aminotransferase (ALT) level than in those with elevated ALT level (p = 0.07). Other HLA alleles are not significantly different between two groups. Comparison of HLA homozygosity at HLA-A and -B or -C or at two or three loci did not show a significant association with levels of serum ALT or with the clinical outcome of interferon therapy in patients with hepatitis C. These results suggest a possibility that the alterations of host response, which depends on genetic background, influence disease activities of HCV infection.

  13. A DISTINCT PEAK-FLUX DISTRIBUTION OF THE THIRD CLASS OF GAMMA-RAY BURSTS: A POSSIBLE SIGNATURE OF X-RAY FLASHES?

    SciTech Connect

    Veres, P.; Bagoly, Z.; Meszaros, A.; Balazs, L. G.

    2010-12-20

    Gamma-ray bursts (GRBs) are the most luminous events in the universe. Going beyond the short-long classification scheme, we work in the context of three burst populations with the third group of intermediate duration and softest spectrum. We are looking for physical properties which discriminate the intermediate duration bursts from the other two classes. We use maximum likelihood fits to establish group memberships in the duration-hardness plane. To confirm these results we also use k-means and hierarchical clustering. We use Monte Carlo simulations to test the significance of the existence of the intermediate group and we find it with 99.8% probability. The intermediate duration population has a significantly lower peak flux (with 99.94% significance). Also, long bursts with measured redshift have higher peak fluxes (with 98.6% significance) than long bursts without measured redshifts. As the third group is the softest, we argue that we have related them with X-ray flashes among the GRBs. We give a new, probabilistic definition for this class of events.

  14. Comparison of the Northeast Arctic cod year class strength (at the age of 3+) with the SST anomalies in main spawning ground (the Norwegian Shelf Waters) by results of analysis satellite monitoring data during last years.

    NASA Astrophysics Data System (ADS)

    Vanyushin, George

    2015-04-01

    Continuous long-term database (1998-2014) on the sea surface temperature (SST) comprising results of regional satellite monitoring (the Norwegian and the Barents seas) is used to resolve several applied problems. Authors have analyzed indirect influence the SST (the NOAA satellite data) on modern cod total stock biomass (abundance of the Northeast Arctic cod at age 3+). In this study, we went on the consideration of the relationship between the SST anomalies for March-April in the main spawning ground of the cod off the Lofoten islands in the Norwegian Shelf Waters and forecasting assessment of future cod generation success and its future abundance of 3 year old. Mean monthly SST and SST anomalies are computed for the selected area on the basis of the weekly SST maps which made by using the NOAA satellites data for the period 1998-2014. Comparison of the SST anomalies in the main spawning ground with abundance of the cod year class at age 3+ shows that survival of the cod generations was inhibited on the whole as negative (below -0,1C) well as positive SST anomalies (above +1,3C) during March and April. Finally, the results indicate that poor and low middle generations of cod at age 3+ (2002, 2004, 2010) occurred in years with negative or extremely high positive the SST anomalies in the spawning area. The SST anomalies in years which were close to normal significances provide conditions for appearance middle or strong generations of cod (2001-2003, 2005-2009, 2011-2013). So, the SST and SST anomalies (by the NOAA satellite data) characterize of increase in input of warm Atlantic waters which form numerous eddies along the main stream thus creating favorable conditions for spawning and development of the cod larvae and fry and provide them with food stock, finally direct influence on forming total stock biomass of cod and helping its population forecast. Key words: satellite monitoring of SST, the Northeast Arctic cod, spawning ground, forecast of the cod year class

  15. Classroom Research: Assessment of Student Understanding of Sampling Distributions of Means and the Central Limit Theorem in Post-Calculus Probability and Statistics Classes

    ERIC Educational Resources Information Center

    Lunsford, M. Leigh; Rowell, Ginger Holmes; Goodson-Espy, Tracy

    2006-01-01

    We applied a classroom research model to investigate student understanding of sampling distributions of sample means and the Central Limit Theorem in post-calculus introductory probability and statistics courses. Using a quantitative assessment tool developed by previous researchers and a qualitative assessment tool developed by the authors, we…

  16. 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.

  17. Clues to tRNA Evolution from the Distribution of Class II tRNAs and Serine Codons in the Genetic Code.

    PubMed

    Bernhardt, Harold S

    2016-01-01

    We have previously proposed that tRNA(Gly) was the first tRNA and glycine was the first amino acid incorporated into the genetic code. The next two amino acids incorporated would have been the other two small hydrophilic amino acids serine and aspartic acid, which occurred through the duplication of the tRNA(Gly) sequence, followed by mutation of its anticodon by single C to U transition mutations, possibly through spontaneous deamination. Interestingly, however, tRNA(Ser) has a different structure than most other tRNAs, possessing a long variable arm; because of this tRNA(Ser) is classified as a class II tRNA. Also, serine codons are found not only in the bottom right-hand corner of the genetic code table next to those for glycine and aspartic acid, but also in the top row of the table, next to those for two of the most hydrophobic amino acids, leucine and phenylalanine. In the following, I propose that the class II tRNA structure of tRNA(Ser) and the arrangement of serine codons in the genetic code provide clues to the early evolution of tRNA and the genetic code. In addition, I address Di Giulio's recent criticism of our proposal that tRNA(Gly) was the first tRNA, and discuss how early peptides produced from a restricted amino acid alphabet of glycine, serine and aspartic acid might have possessed proteolytic activity, which is possibly important for the early recycling of amino acid monomers. PMID:26927183

  18. Clues to tRNA Evolution from the Distribution of Class II tRNAs and Serine Codons in the Genetic Code

    PubMed Central

    Bernhardt, Harold S.

    2016-01-01

    We have previously proposed that tRNAGly was the first tRNA and glycine was the first amino acid incorporated into the genetic code. The next two amino acids incorporated would have been the other two small hydrophilic amino acids serine and aspartic acid, which occurred through the duplication of the tRNAGly sequence, followed by mutation of its anticodon by single C to U transition mutations, possibly through spontaneous deamination. Interestingly, however, tRNASer has a different structure than most other tRNAs, possessing a long variable arm; because of this tRNASer is classified as a class II tRNA. Also, serine codons are found not only in the bottom right-hand corner of the genetic code table next to those for glycine and aspartic acid, but also in the top row of the table, next to those for two of the most hydrophobic amino acids, leucine and phenylalanine. In the following, I propose that the class II tRNA structure of tRNASer and the arrangement of serine codons in the genetic code provide clues to the early evolution of tRNA and the genetic code. In addition, I address Di Giulio’s recent criticism of our proposal that tRNAGly was the first tRNA, and discuss how early peptides produced from a restricted amino acid alphabet of glycine, serine and aspartic acid might have possessed proteolytic activity, which is possibly important for the early recycling of amino acid monomers. PMID:26927183

  19. Synaptic distributions of GluA2 and PKMζ in the monkey dentate gyrus and their relationships with aging and memory.

    PubMed

    Hara, Yuko; Punsoni, Michael; Yuk, Frank; Park, C Sehwan; Janssen, William G M; Rapp, Peter R; Morrison, John H

    2012-05-23

    Rhesus monkeys provide a valuable model for studying the neurobiological basis of cognitive aging, because they are vulnerable to age-related memory decline in a manner similar to humans. In this study, young and aged monkeys were first tested on a well characterized recognition memory test (delayed nonmatching-to-sample; DNMS). Then, electron microscopic immunocytochemistry was performed to determine the subcellular localization of two proteins in the hippocampal dentate gyrus (DG): the GluA2 subunit of the glutamate AMPA receptor and the atypical protein kinase C ζ isoform (PKMζ). PKMζ promotes memory storage by regulating GluA2-containing AMPA receptor trafficking. Thus, we examined whether the distribution of GluA2 and PKMζ is altered with aging in DG axospinous synapses and whether it is coupled with memory deficits. Monkeys with faster DNMS task acquisition and more accurate recognition memory exhibited higher proportions of dendritic spines coexpressing GluA2 and PKMζ. These double-labeled spines had larger synapses, as measured by postsynaptic density area, than single-labeled and unlabeled spines. Within this population of double-labeled spines, aged monkeys compared with young expressed a lower density of synaptic GluA2 immunogold labeling, which correlated with lower recognition accuracy. Additionally, higher density of synaptic PKMζ labeling in double-labeled spines correlated with both faster task acquisition and better retention. Together, these findings suggest that age-related impairment in maintenance of GluA2 at the synapse in the primate hippocampus is coupled with memory deficits.

  20. 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, E.O.; Box, S.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.

  1. Hindcasting of the Gulf of Mexico Circulation and Age and Distribution of the Oil Plume Arising from the Deepwater Horizon Spill

    NASA Astrophysics Data System (ADS)

    He, R.; Zhang, W.; Hyun, K.; Chen, K.; Qian, H.

    2010-12-01

    We used a realistic regional ocean model to investigate the Gulf of Mexico circulation and 3-dimensional distributions of oil released from the BP Deepwater Horizon (DH) well. Circulation hindcast was generated by NCSU SABGOM, a ROMS model of the Gulf of Mexico and South Atlantic Bight. We ran this model for the time period of the oil spill starting on April 20, 2010. Simulated ocean states were gauged against in-situ observations, including ship CTD, glider transects, AXBT profiles, drifter trajectories, and HF surface currents. Along with the circulation prediction, an online Eulerian age tracer simulation was used to model the dispersion and age of oil plume over time, the latter information indicates how long the BP DH sourced constituents at a given location ( lon, lat, depth) and time have been in the ocean. The tracer prediction and its skill assessment against subsurface dissolved oxygen anomaly observations (as the proxy of oil plume) will be presented and discussed.

  2. Frequency distribution and discrimination probability of twelve protein genetic variants in human blood as functions of race, sex, and age.

    PubMed

    Grunbaum, B W; Selvin, S; Pace, N; Black, D M

    1978-07-01

    Fresh blood samples were obtained from 6004 whites, 1025 blacks, 1596 Chicano/Amerindians, and 3053 Asians of California and Hawaii. The samples were typed for ABO and Rh groups and were analyzed electrophoretically for ten genetically determined protein variant systems. The effects of race, age, and sex on phenotypic frequencies within each of the twelve genetic systems were investigated. Large frequency differences were found between races but not between different age and sex subgroups within races. It was also demonstrated that the twelve genetic systems behaved statistically independently. Discrimination probabilities were computed for each of the four ethnic groups. These serve as a measure of the effectiveness of the twelve genetic systems examined in individualizing blood samples. The method is discussed for computing the probability that a randomly chosen individual of a given ethnic group possesses the same blood phenotypes as found in a predetermined sample of blood. The results presented here should prove useful in the investigation of civil and criminal cases involving blood samples.

  3. 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.

  4. 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

  5. Biochemical distributions (amino acids, neutral sugars, and lignin phenols) among size-classes of modern marine sediments from the Washington coast

    NASA Astrophysics Data System (ADS)

    Keil, Richard G.; Tsamakis, Elizabeth; Giddings, J. Calvin; Hedges, John I.

    1998-04-01

    lignin phenol yields and low acid/aldehyde ratios. Clay-size fractions are enriched in nitrogenous components, as reflected by elevated yields of total and basic amino acids (especially lysine). Silt- and sand-size fractions rich in quartz and albite show slightly higher yields of neutral amino acids. Consistent trends across all size classes and among the different depositional settings illustrates that only a small portion of the organic matter is present as distinct organic debris (e.g. pollen, vascular plant tissues, etc.), but that this debris can be isolated in specific size classes. The data for surface-associated organic matter are consistent with, but not conclusive of, selective partitioning of some organic matter to specific mineral surfaces. The dominant size class-specific trends in organic matter composition are due to changes in both source and diagenetic alteration.

  6. Class distinction

    NASA Astrophysics Data System (ADS)

    White, M. Catherine

    Typical 101 courses discourage many students from pursuing higher level science and math courses. Introductory classes in science and math serve largely as a filter, screening out all but the most promising students, and leaving the majority of college graduates—including most prospective teachers—with little understanding of how science works, according to a study conducted for the National Science Foundation. Because few teachers, particularly at the elementary level, experience any collegiate science teaching that stresses skills of inquiry and investigation, they simply never learn to use those methods in their teaching, the report states.

  7. Regional Differences in Carbon Storage Based on Distribution of Forest Age across Russia Using the FAREAST Gap Model and Detailed Forest Inventory Data

    NASA Astrophysics Data System (ADS)

    Shuman, J. K.; Krankina, O. N.; Shugart, H. H.

    2007-12-01

    The FAREAST model, an individual-based forest-dynamics model, was developed to simulate forests of Changbai Mountain in northern China. It was then applied to forests at selected sites in Siberia and the Russian Far East. More recently, the model was used to generate results for expected biomass and species composition of mature forest landscapes for 223 sites across all of Russia. After these results were published, we became aware of actual forest survey data (developed by one of the authors, Krankina) arranged in 10-year intervals based on the age of the forest. Age in this case refers the age of the dominant tree cohort in a stand. These data were in percent coverage of total forest area surveyed for 36 forest sites aggregated in three regions denoted the northwest, south, and far eastern regions of Russia. This presented the opportunity to predict an expected biomass for the three regions corrected for age structure. The original simulation data was sorted to match the field data for regional forest age-cohort structure of the three regions. Thirty-four simulation sites from the original paper were distributed in the three regions used in the field study. This simulation data was re-compiled as biomass (tCha-1) for simulation plots summed at each 10 year interval from year zero to mature forests (250 years) and multiplied times the relative percent coverage in each age category. Using the expected biomass for the three regions derived from the inventory data, we obtain a picture of the current carbon storage across Russia. The potential change in carbon storage for these regions was found by calculating the difference between the expected biomass of a mature forest (250 years), the current forest state (derived from inventory data), and a managed forest condition characterized by an even distribution of age cohorts for each 10-year interval. The simulation biomass data was validated using novel cohort data arranged according to species biomass (tCha-1) from

  8. The implications of small stem cell niche sizes and the distribution of fitness effects of new mutations in aging and tumorigenesis.

    PubMed

    Cannataro, Vincent L; McKinley, Scott A; St Mary, Colette M

    2016-04-01

    Somatic tissue evolves over a vertebrate's lifetime due to the accumulation of mutations in stem cell populations. Mutations may alter cellular fitness and contribute to tumorigenesis or aging. The distribution of mutational effects within somatic cells is not known. Given the unique regulatory regime of somatic cell division, we hypothesize that mutational effects in somatic tissue fall into a different framework than whole organisms; one in which there are more mutations of large effect. Through simulation analysis, we investigate the fit of tumor incidence curves generated using exponential and power-law distributions of fitness effects (DFE) to known tumorigenesis incidence. Modeling considerations include the architecture of stem cell populations, that is, a large number of very small populations, and mutations that do and do not fix neutrally in the stem cell niche. We find that the typically quantified DFE in whole organisms is sufficient to explain tumorigenesis incidence. Further, deleterious mutations are predicted to accumulate via genetic drift, resulting in reduced tissue maintenance. Thus, despite there being a large number of stem cells throughout the intestine, its compartmental architecture leads to the accumulation of deleterious mutations and significant aging, making the intestinal stem cell niche a prime example of Muller's Ratchet.

  9. Optimal Communication Network-Based H∞ Quantized Control With Packet Dropouts for a Class of Discrete-Time Neural Networks With Distributed Time Delay.

    PubMed

    Han, Qing-Long; Liu, Yurong; Yang, Fuwen

    2016-02-01

    This paper is concerned with optimal communication network-based H∞ quantized control for a discrete-time neural network with distributed time delay. Control of the neural network (plant) is implemented via a communication network. Both quantization and communication network-induced data packet dropouts are considered simultaneously. It is assumed that the plant state signal is quantized by a logarithmic quantizer before transmission, and communication network-induced packet dropouts can be described by a Bernoulli distributed white sequence. A new approach is developed such that controller design can be reduced to the feasibility of linear matrix inequalities, and a desired optimal control gain can be derived in an explicit expression. It is worth pointing out that some new techniques based on a new sector-like expression of quantization errors, and the singular value decomposition of a matrix are developed and employed in the derivation of main results. An illustrative example is presented to show the effectiveness of the obtained results.

  10. 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

  11. SEASONAL PATTERNS OF FINE ROOT PRODUCTION AND TURNOVER IN PONDEROSA PINE STANDS OF DIFFERENT AGES

    EPA Science Inventory

    Root minirhizotron tubes were installed in two ponderosa pine (Pinus ponderosa Laws.) stands around three different tree age classes (16, 45, and > 250 yr old) to examine root spatial distribution in relation to canopy size and tree distribution, and to determine if rates of fine...

  12. Impact of the aging process of black carbon aerosols on their spatial distribution, hygroscopicity, and radiative forcing in a global climate model

    NASA Astrophysics Data System (ADS)

    Goto, D.; Oshima, N.; Nakajima, T.; Takemura, T.; Ohara, T.

    2012-11-01

    Black carbon (BC) absorbs shortwave radiation more strongly than any other type of aerosol, and an accurate simulation of the aging processes of BC-containing particle is required to properly predict aerosol radiative forcing (ARF) and climate change. However, BC aging processes have been simplified in general circulation models (GCMs) due to limited computational resources. In particular, differences in the representation of the mixing states of BC-containing particles between GCMs constitute one of main reasons for the uncertainty in ARF estimates. To understand an impact of the BC aging processes and the mixing state of BC on the spatial distribution of BC and ARF caused by BC (BC-ARF), we implemented three different methods of incorporating BC aging processes into a global aerosol transport model, SPRINTARS: (1) the "AGV" method, using variable conversion rates of BC aging based on a new type of parameterization depending on both BC amount and sulfuric acid; (2) the "AGF" method, using a constant conversion rate used worldwide in GCMs; and (3) the "ORIG" method, which is used in the original SPRINTARS. First, we found that these different methods produced different BC burden within 10% over industrial areas and 50% over remote oceans. Second, a ratio of water-insoluble BC to total BC (WIBC ratio) was very different among the three methods. Near the BC source region, for example, the WIBC ratios were estimated to be 80-90% (AGV and AGF) and 50-60% (ORIG). Third, although the BC aging process in GCMs had small impacts on the BC burden, they had a large impact on BC-ARF through a change in both the WIBC ratio and non-BC compounds coating on BC cores. As a result, possible differences in the treatment of the BC aging process between aerosol modeling studies can produce a difference of approximately 0.3 Wm-2 in the magnitude of BC-ARF, which is comparable to the uncertainty suggested by results from a global aerosol modeling intercomparison project, AeroCom. The

  13. Purkinje cell age-distribution in fissures and in foliar crowns: a comparative study in the weaver cerebellum.

    PubMed

    Martí, Joaquín; Santa-Cruz, M C; Bayer, Shirley A; Ghetti, Bernardino; Hervás, José P

    2007-12-01

    Generation and settling of Purkinje cells (PCs) are investigated in the weaver mouse cerebellum in order to determine possible relationships with the fissuration pattern. Tritiated thymidine was supplied to pregnant females at the time that these neurons were being produced. Autoradiography was then applied on brain sections obtained from control and weaver offspring at postnatal (P) day 90. This makes it possible to assess the differential survival of neurons born at distinct embryonic times on the basis of the proportion of labeled cells located at the two foliar compartments: fissures and foliar crowns. Our data show that throughout the surface contour of the vermal lobes, generative programs of PCs were close between wild type and homozygous weaver. Similar data were found in the lobules of the lateral hemisphere. On the other hand, the loss of PCs in weaver cerebella can be related to foliar concavities or convexities depending on the vermal lobe or the hemispheric lobule studied. Lastly, we have obtained evidence that late-generated PCs of both normal and mutant mice were preferentially located in fissures. These quantitative relationships lead us to propose a model in which the final distribution of PCs through the vermal contour would be coupled to two factors: the cortical fissuration patterning and a "time-sequential effect" of weaver mutation.

  14. How Consistent Are Class Size Effects?

    ERIC Educational Resources Information Center

    Konstantopoulos, Spyros

    2011-01-01

    Thus far researchers have focused on computing average differences in student achievement between smaller and larger classes. In this study, the author focus on the distribution of the small class effects at the school level and compute the inconsistency of the small class effects across schools. The author use data from Project STAR to estimate…

  15. 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

  16. Class Size, Class Composition, and the Distribution of Student Achievement

    ERIC Educational Resources Information Center

    Bosworth, Ryan

    2014-01-01

    Using richly detailed data on fourth- and fifth-grade students in the North Carolina public school system, I find evidence that students are assigned to classrooms in a non-random manner based on observable characteristics for a substantial portion of classrooms. Moreover, I find that this non-random assignment is statistically related to class…

  17. Molecular distributions and stable carbon isotopic compositions of dicarboxylic acids and related compounds in aerosols from Sapporo, Japan: Implications for photochemical aging during long-range atmospheric transport

    NASA Astrophysics Data System (ADS)

    Aggarwal, Shankar G.; Kawamura, Kimitaka

    2008-07-01

    Molecular and stable carbon isotopic (δ13C value) compositions of dicarboxylic acids, ketoacids, and dicarbonyls in aerosol samples (i.e., total suspended particles) collected in Sapporo, northern Japan during spring and summer were determined to better understand the photochemical aging of organic aerosols during long-range transport from East Asia and Siberia. Their molecular distributions were characterized by the predominance of oxalic acid (C2) followed by malonic (C3) or occasionally succinic (C4) acids. Concentrations of total diacids ranged from 106-787 ng m-3 with ketoacids (13-81 ng m-3) and dicarbonyls (2.6-28 ng m-3) being less abundant. Water-soluble organic carbon (WSOC) comprised 23-69% of aerosol organic carbon (OC). OC to elemental carbon (EC) ratios were high (3.6-19, mean: 8.7). The ratios of C3/C4 and WSOC/OC did not show significant diurnal changes, suggesting that the Sapporo aerosols were not seriously affected by local photochemical processes and instead they were already aged. δ13C values of the dominant diacids (C2 - C4) ranged from -14.0 to -25.3‰. Largest δ13C values (-14.0 to -22.4‰, mean: -18.8‰) were obtained for C2, whereas smallest values (-25.1 to -31.4‰, mean: -28.1‰) were for azelaic acid (C9). In general, δ13C values of C2 - C4 diacids became less negative with aerosol aging (i.e., WSOC/OC), presumably due to isotopic fractionation during photochemical degradation of diacids. By comparing the δ13C values of diacids in the Sapporo aerosols with different air mass source regions, we suggest that although initial δ13C values of diacids depend on their precursor sources, the enrichment in 13C can be ascribed to aerosol photochemical aging.

  18. 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

  19. Phylogenetic Distribution and Prevalence of Genes Encoding Class I Integrons and CTX-M-15 Extended-Spectrum β-Lactamases in Escherichia coli Isolates from Healthy Humans in Chandigarh, India

    PubMed Central

    Dureja, Chetna; Mahajan, Sakshi; Raychaudhuri, Saumya

    2014-01-01

    Escherichia coli is generally considered as a commensal inhabitant of gastrointestinal tract of humans and animals. The aim of this study was to gain insight on the distribution of phylotypes and presence of genes encoding integrons, extended β-lactamases and resistance to other antimicrobials in the commensal E. coli isolates from healthy adults in Chandigarh, India. PCR and DNA sequencing were used for phylogenetic classification, detections of integrase genes, gene cassettes within the integron and extended β-lactamases. The genetic structure of E. coli revealed a non-uniform distribution of isolates among the seven phylogenetic groups with significant representation of group A. Integron-encoded integrases were detected in 25 isolates with class 1 integron-encoded intI1 integrase being in the majority (22 isolates). The gene cassettes identified were those for trimethoprim, streptomycin, spectinomycin and streptothricin. The dfrA12-orfF-aadA2 was the most commonly found gene cassette in intI1 positive isolates. Phenotypic assay for screening the potential ESBL producers suggested 16 isolates to be ESBL producers. PCR detection using gene-specific primers showed that 15 out of these 16 ESBL-producing E. coli harboured the blaCTX-M-15 gene. Furthermore, molecular studies helped in characterizing the genes responsible for tetracycline, chloramphenicol and sulphonamides resistance. Collectively, our study outlines the intra-species phylogenetic structure and highlights the prevalence of class 1 integron and blaCTX-M-15 in commensal E. coli isolates of healthy adults in Chandigarh, India. Our findings further reinforce the relevance of commensal E. coli strains on the growing burden of antimicrobial resistance. PMID:25409321

  20. 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

  1. 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.

  2. Influence of dietary fat on metabolism of (14-/sup 14/C)erucic acid in the perfused rat liver. Distribution of metabolites in lipid classes

    SciTech Connect

    Holmer, G.; Ronneberg, R.

    1986-06-01

    Two groups of rats were fed diets containing 20% by weight of either partially hydrogenated marine oil supplemented with sunflower seed oil (PHMO) or palm oil (PO) for 8 wk. Using a liver perfusion system, the effect of dietary long chain monoenoic fatty acids on the uptake and metabolism of (14-/sup 14/C)erucic acid was studied. The perfusion times were 15 and 60 min, respectively. The two groups showed equal ability for erucic acid uptake in the liver but differed in the channeling of the fatty acids into various metabolic pathways. A higher metabolic turnover of 22:1 in the PHMO livers relative to the PO livers was demonstrated by an increased recovery of total (/sup 14/C)labeling in the triglyceride (TG) and phospholipid (PL) fractions, already evident after 15 min of perfusion. The chain-shortening capacity was highest in the PHMO group, reflected by a higher (/sup 14/C)18:1 incorporation in both TG and PL, and increasing from 15 to 60 min of perfusion. The amount of (/sup 14/C)18:1 found in PL and TG after 60 min of perfusion of livers from rats fed PO corresponded to that shown for the PHMO group after 15 min. The PL demonstrated a discrimination against 22:1 compared to TG, and, when available, 18:1 was highly preferred for PL-synthesis. The total fatty acid distribution in the TG, as determined by gas liquid chromatography (GLC), reflected the composition of the dietary fats. In the total liver PL, 22:1 and 20:1 were present in negligible amounts, although the PHMO diet contained 12-13% of both 22:1 and 20:1. In the free fatty acid fraction (FFA), the major part of the radioactivity (approximately 80%) was (14-/sup 14/C)erucic acid, and only small amounts of (/sup 14/C)18:1 (less than 2%) were present, even after 60 min of perfusion. The shortened-chain 18:1 was readily removed from the FFA pool and preferentially used for lipid esterification.

  3. Geographic distribution, age pattern and sites of lesions in a cohort of Buruli ulcer patients from the Mapé Basin of Cameroon.

    PubMed

    Bratschi, Martin W; Bolz, Miriam; Minyem, Jacques C; Grize, Leticia; Wantong, Fidèle G; Kerber, Sarah; Njih Tabah, Earnest; Ruf, Marie-Thérèse; Mou, Ferdinand; Noumen, Djeunga; Um Boock, Alphonse; Pluschke, Gerd

    2013-01-01

    Buruli ulcer (BU), a neglected tropical disease of the skin, caused by Mycobacterium ulcerans, occurs most frequently in children in West Africa. Risk factors for BU include proximity to slow flowing water, poor wound care and not wearing protective clothing. Man-made alterations of the environment have been suggested to lead to increased BU incidence. M. ulcerans DNA has been detected in the environment, water bugs and recently also in mosquitoes. Despite these findings, the mode of transmission of BU remains poorly understood and both transmission by insects or direct inoculation from contaminated environment have been suggested. Here, we investigated the BU epidemiology in the Mapé basin of Cameroon where the damming of the Mapé River since 1988 is believed to have increased the incidence of BU. Through a house-by-house survey in spring 2010, which also examined the local population for leprosy and yaws, and continued surveillance thereafter, we identified, till June 2012, altogether 88 RT-PCR positive cases of BU. We found that the age adjusted cumulative incidence of BU was highest in young teenagers and in individuals above the age of 50 and that very young children (<5) were underrepresented among cases. BU lesions clustered around the ankles and at the back of the elbows. This pattern neither matches any of the published mosquito biting site patterns, nor the published distribution of small skin injuries in children, where lesions on the knees are much more frequent. The option of multiple modes of transmission should thus be considered. Analyzing the geographic distribution of cases in the Mapé Dam area revealed a closer association with the Mbam River than with the artificial lake. PMID:23785529

  4. A Reactive Transport Model for the Distribution and Age of Carbon in Soils and Sediments Through Direct Simulation of the Stable and Radiogenic Isotopologues

    NASA Astrophysics Data System (ADS)

    Druhan, J. L.; Lawrence, C. R.

    2015-12-01

    We present a reactive transport (RT) approach to link hydrologic transport, geochemical transformations and microbial activity influencing the magnitude and residence time of different carbon pools under variably saturated conditions. This model explicitly simulates the simultaneous transport, transformation, fractionation and decay of the three isotopes of carbon (12C, 13C and 14C) through a mechanistic framework. This is demonstrated with a modification of the CrunchTope multi-component RT software to extend the isotope-specific versions of both microbially-mediated and transition state theory (TST) rate laws to accommodate a three-isotope system. In addition both aqueous and solid phase decay of 14C are tracked, yielding in an implicit means of accounting for the 13C/12C correction in normalized radiocarbon ages. The capacity of this approach to quantify the storage and flux of carbon through subsurface compartments is demonstrated using two examples distinguished by timescale. The first considers a simplified flow path in which an influent containing labile organic carbon is distributed by biogenic reduction and mineralization into a suite of reaction products. The residence time of these pools and their characteristic stable isotope ratios are tracked through a variety of transient processes occurring at short timescales (e.g. months). These include a change in fluid flow rate, a limitation of ammonium supporting anabolic growth and an influx of oxygenated fluid. The second example considers the distribution of carbon over the timescale of soil development (e.g., millennia), using a dataset of stable isotope ratios and radiocarbon ages of organic and inorganic carbon present in both dissolved and solid phases from a soil chronosequence near Santa Cruz, CA. The results of these model simulations suggest the promise of this tool for improving our understanding of coupling between hydrologic transport and biogeochemical reactions in soils.

  5. Geographic Distribution, Age Pattern and Sites of Lesions in a Cohort of Buruli Ulcer Patients from the Mapé Basin of Cameroon

    PubMed Central

    Bratschi, Martin W.; Bolz, Miriam; Minyem, Jacques C.; Grize, Leticia; Wantong, Fidèle G.; Kerber, Sarah; Njih Tabah, Earnest; Ruf, Marie-Thérèse; Mou, Ferdinand; Noumen, Djeunga; Um Boock, Alphonse; Pluschke, Gerd

    2013-01-01

    Buruli ulcer (BU), a neglected tropical disease of the skin, caused by Mycobacterium ulcerans, occurs most frequently in children in West Africa. Risk factors for BU include proximity to slow flowing water, poor wound care and not wearing protective clothing. Man-made alterations of the environment have been suggested to lead to increased BU incidence. M. ulcerans DNA has been detected in the environment, water bugs and recently also in mosquitoes. Despite these findings, the mode of transmission of BU remains poorly understood and both transmission by insects or direct inoculation from contaminated environment have been suggested. Here, we investigated the BU epidemiology in the Mapé basin of Cameroon where the damming of the Mapé River since 1988 is believed to have increased the incidence of BU. Through a house-by-house survey in spring 2010, which also examined the local population for leprosy and yaws, and continued surveillance thereafter, we identified, till June 2012, altogether 88 RT-PCR positive cases of BU. We found that the age adjusted cumulative incidence of BU was highest in young teenagers and in individuals above the age of 50 and that very young children (<5) were underrepresented among cases. BU lesions clustered around the ankles and at the back of the elbows. This pattern neither matches any of the published mosquito biting site patterns, nor the published distribution of small skin injuries in children, where lesions on the knees are much more frequent. The option of multiple modes of transmission should thus be considered. Analyzing the geographic distribution of cases in the Mapé Dam area revealed a closer association with the Mbam River than with the artificial lake. PMID:23785529

  6. Age and gender distribution of Hepatitis C virus prevalence and genotypes of individuals of physical examination in WuHan, Central China.

    PubMed

    Niu, ZhiLi; Zhang, PingAn; Tong, YongQing

    2016-01-01

    Approximately 170 million people in the world are infected with Hepatitis C virus (HCV). There are no published population based studies about the prevalence of HCV genotypes and the associations of genotype and Infection frequency with gender and age in WuHan. We aimed to investigate the distribution of HCV prevalence and genotypes among different gender and age patients with chronic HCV infection in WuHan from 2011 to 2015. A total of 2685 anti-HCV positive serum samples from individuals of physical examinationwere recruited from the Renmin Hospital of WuHan University, Hubei Province in China from January 2011 to December 2015. From these 2685 anti-HCV positive serum samples, 496 samples were with a positive PCR for HCV RNA. The number of HCV infection showed an increase with year, but the annual infection rate has remained similar (χ(2) = 2.94, P = 0.568). 2685 cases were infected with HCV from 2011 to 2015 in WuHan city of China. Blood transfusion (18.14 %) was the main routs of transmission, followed by Surgery (8.94 %). The highest prevalence of HCV infection was at the age group 50-59 (25.85 % of 2685) and the lowest prevalence was 0-9 (0.93 % of 2685). HCV genotype 1 was the most prevalent (73.39 %), followed by genotypes 2 (17.14 %), 3 (5.25 %) and 6 (3.22 %). Genotype 4 and 5 was not detected in these patients. The most prevalent subtype was subtype 1b (71.98 %), followed by genotypes 2a (17.14 %). Five patients had mixed infection across the HCV subtypes. Among all genotypes, genotype 1 was highest in both male (73.27 %) and female (73.47 %) patients, followed by genotype 2. Genotype 1 (male: 29.84 % of 496, vs female: 43.55 % of 496, χ(2) = 20.07, P < 0.0001), genotype 2 (male: 6.25 % of 496, vs female: 10.89 % of 496, χ(2) = 6.81, P = 0.009), and 6 (male: 1.41 % of 496, vs female: 1.81 % of 496, χ(2) = 0.626, P = 0.401) were more common in female patients than males, while no significant gender differences were

  7. Age and gender distribution of Hepatitis C virus prevalence and genotypes of individuals of physical examination in WuHan, Central China.

    PubMed

    Niu, ZhiLi; Zhang, PingAn; Tong, YongQing

    2016-01-01

    Approximately 170 million people in the world are infected with Hepatitis C virus (HCV). There are no published population based studies about the prevalence of HCV genotypes and the associations of genotype and Infection frequency with gender and age in WuHan. We aimed to investigate the distribution of HCV prevalence and genotypes among different gender and age patients with chronic HCV infection in WuHan from 2011 to 2015. A total of 2685 anti-HCV positive serum samples from individuals of physical examinationwere recruited from the Renmin Hospital of WuHan University, Hubei Province in China from January 2011 to December 2015. From these 2685 anti-HCV positive serum samples, 496 samples were with a positive PCR for HCV RNA. The number of HCV infection showed an increase with year, but the annual infection rate has remained similar (χ(2) = 2.94, P = 0.568). 2685 cases were infected with HCV from 2011 to 2015 in WuHan city of China. Blood transfusion (18.14 %) was the main routs of transmission, followed by Surgery (8.94 %). The highest prevalence of HCV infection was at the age group 50-59 (25.85 % of 2685) and the lowest prevalence was 0-9 (0.93 % of 2685). HCV genotype 1 was the most prevalent (73.39 %), followed by genotypes 2 (17.14 %), 3 (5.25 %) and 6 (3.22 %). Genotype 4 and 5 was not detected in these patients. The most prevalent subtype was subtype 1b (71.98 %), followed by genotypes 2a (17.14 %). Five patients had mixed infection across the HCV subtypes. Among all genotypes, genotype 1 was highest in both male (73.27 %) and female (73.47 %) patients, followed by genotype 2. Genotype 1 (male: 29.84 % of 496, vs female: 43.55 % of 496, χ(2) = 20.07, P < 0.0001), genotype 2 (male: 6.25 % of 496, vs female: 10.89 % of 496, χ(2) = 6.81, P = 0.009), and 6 (male: 1.41 % of 496, vs female: 1.81 % of 496, χ(2) = 0.626, P = 0.401) were more common in female patients than males, while no significant gender differences were

  8. 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.

  9. Effects of age and reproductive experience on the distribution of prolactin and growth hormone secreting cells in the anterior pituitary of a passerine.

    PubMed

    Christensen, Debora; Vleck, Carol M

    2015-10-01

    Plasma prolactin (PRL) is released from lactotrophs in the anterior pituitary. As plasma PRL levels rise during incubation in domestic fowl, the number of lactotrophs (PRL-immunoreactive, PRL-IR cells) increases while the number of growth hormone secreting cells, somatotrophs (GH-IR cells), declines. We measured plasma PRL levels using radioimmunoassay (RIA) and examined the distribution of lactotrophs and somatotrophs in the anterior pituitary of breeding and nonbreeding zebra finches of known ages with and without prior breeding experience using fluorescent immunohistochemistry (IHC). Plasma PRL levels were higher in breeding than in nonbreeding birds, regardless of age, sex, or previous breeding history. PRL-IR cells were localized primarily, but not exclusively, to the cephalic aspect of the anterior pituitary (AP) and along the ventral margin. Birds with prior reproductive experience had more PRL-IR cells than birds with no prior reproductive experience and breeders had slightly higher PRL-IR cell counts than did nonbreeders, but there was no correlation between the number of PRL-IR cells and plasma PRL levels. GH-IR cells were concentrated in the caudal aspect of the AP with some cells in the cephalic lobe, but numbers did not differ between any of the groups studied. An increase in PRL-IR cells corresponded with an increase in GH-IR cells. An increase in lactotroph number with reproductive experience in zebra finches may facilitate future reproductive events by allowing for more robust PRL secretion and increased reproductive success.

  10. 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.

  11. Evolution of alanine:glyoxylate aminotransferase 1 peroxisomal and mitochondrial targeting. A survey of its subcellular distribution in the livers of various representatives of the classes Mammalia, Aves and Amphibia.

    PubMed

    Danpure, C J; Fryer, P; Jennings, P R; Allsop, J; Griffiths, S; Cunningham, A

    1994-08-01

    As part of a wider study on the molecular evolution of alanine:glyoxylate aminotransferase 1 (AGT1) intracellular compartmentalization, we have determined the subcellular distribution of immunoreactive AGT1, using postembedding protein A-gold immunoelectron microscopy, in the livers of various members of the classes Mammalia, Aves, and Amphibia. As far as organellar distribution is concerned, three categories could be distinguished. In members of the first category (type I), all, or nearly all, of the immunoreactive AGT1 was concentrated within the peroxisomes. In the second category (type II), AGT1 was found more evenly distributed in both peroxisomes and mitochondria. In the third category (type III), AGT1 was localized mainly within the mitochondria with much lower, but widely variable, amounts in the peroxisomes. Type I animals include the human, two great apes (gorilla, orangutan), two Old World monkeys (anubis baboon, Japanese macaque), a New World monkey (white-faced Saki monkey), a lago, morph (European rabbit), a bat (Seba's short-tailed fruit bat), two caviomorph rodents (guinea pig, orange-rumped agouti), and two Australian marsupials (koala, Bennett's wallaby). Type II animals include two New World monkeys (common marmoset, cotton-top tamarin), three prosimians (brown lemur, fat-tailed dwarf lemur, pygmy slow loris), five rodents (a hybrid crested porcupine, Colombian ground squirrel, laboratory rat, laboratory mouse, golden hamster), an American marsupial (grey short-tailed opossum), and a bird (raven). Type III animals include the large tree shrew, three insectivores (common Eurasian mole, European hedgehog, house shrew), four carnivores (domestic cat, ocelot, domestic dog, polecat ferret), and an amphibian (common frog). In addition to these categories, some animals (e.g. guinea pig, common frog) possessed significant amounts of cytosolic AGT1. Whereas the subcellular distribution of AGT1 in some orders (e.g. Insectivora and Carnivora) did not appear

  12. Geodynamic setting of mineralization of Mississippi Valley-type deposits in world-class Sichuan-Yunnan-Guizhou Zn-Pb triangle, southwest China: Implications from age-dating studies in the past decade and the Sm-Nd age of Jinshachang deposit

    NASA Astrophysics Data System (ADS)

    Zhang, Changqing; Wu, Yue; Hou, Lin; Mao, Jingwen

    2015-05-01

    The Sichuan-Yunnan-Guizhou (S-Y-G) Zn-Pb triangle is a world-class metallogenic belt in southwestern China that contains hundreds of carbonate-hosted giant-to-small epigenetic Zn-Pb deposits. Here, we provide an overview of the ore geology, geochemistry and ore-forming fluids of the major Zn-Pb deposits in this area. These deposits are most likely Mississippi Valley-type (MVT) deposits that formed as a result of the regional migration of basinal brines along large fault systems and more minor secondary structures. The Sm-Nd age (201 ± 6.2 Ma) of ore-stage fluorite from the Jinshachang Zn-Pb deposit, within northeast Yunnan province, China, reveals this deposit formed during the Late Triassic, consistent with the majority of the published isotopic ages for other Zn-Pb deposits in the S-Y-G MVT triangle. These fluorite samples have initial 87Sr/86Sr ratios of 0.711385-0.711463 and εNd values of -8.4 to -8.7, confirming the basin-related nature of the mineralizing fluids. Published geochronological data combined with basic features of MVT deposits (e.g., geology, geochemistry, and ore-forming fluids) and the geological evolution of the study area has enabled us to develop a model for the Zn-Pb mineralization, where this word-class MVT belt has formed as a result of the regional-scale migration of basinal fluids coincident with tectonic activity along ore-controlling structures (e.g., thrust-fold systems). Both the fluid migration and the tectonic activity were probably triggered by the late Indosinian Orogeny, which in turn was a response to the closure of the Paleo-Tethys Ocean.

  13. 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.;