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Sample records for age specific rates

  1. Age-specific divorce rates.

    PubMed

    Kunz, P R; England, J L

    1988-01-01

    This paper examines the various types of US divorce rates in 1970 and 1980 and concludes that the age-specific rate is most precise. Using data from the states' vital statistics reports and the 1980 census reports for states, the authors conclude that the teen and early 20s marriages are most at risk to divorce. Rates have increased from 1970 to 1980 with the most dramatic increases occurring in the 25-35 and 40-44 age groups. Study needs to be done to see what factors have led to such disproportionate increases in divorce rates in these age categories. Similarly, research is needed to understand why the 55 and over groups show no change of decline in rates between 1970 and 1980 in light of increases in other age groups. Contrary to general belief, however, divorce does not increase during the 'mid-life crisis' or ' after the children leave home.' PMID:12281968

  2. Age specific xerophthalmia rates among displaced Ethiopians.

    PubMed

    Pizzarello, L D

    1986-11-01

    The recent famine in Ethiopia has resulted in the dislocation of millions of people. Many of these individuals have moved to refugee camps in Sudan or to feeding centres within Ethiopia. A total of 1325 children up to the age of 15 years were examined by an ophthalmologist in January 1985 at several sites in these two countries. The rates of Bitot's spots were three times greater in those between the ages of 7 and 10 compared with those under 7. Rates of corneal xerosis were comparable for each group. Previously, xerophthalmia was considered predominantly to affect children aged under 6. These data document the presence of the disease in older children and raise questions regarding future modifications in the prevention and treatment of xerophthalmia.

  3. The Application of Age-Specific Rates to Divorce

    ERIC Educational Resources Information Center

    England, J. Lynn; Kunz, Phillip R.

    1975-01-01

    Age-Specific divorce rates and weighted divorce rates are evaluated in comparison with several traditional rates. The analysis reversals of the ranking of some states in comparison with rankings based on other divorce rates, and the age-specific rates for young married couples is lower than expected. (Author)

  4. Age-Specific Citation Rates and the Egghe-Rao Function.

    ERIC Educational Resources Information Center

    Burrell, Quentin L.

    2003-01-01

    Extends connections between retrospective citation age studies and reliability theory by considering the failure rate function from reliability, re-interpreted as the age-specific citation rate (ASCR). This is linked to earlier studies of retrospective citation distributions by Egghe and Ravichandra Rao who introduced a function claimed to…

  5. Problems in estimating age-specific survival rates from recovery data of birds ringed as young

    USGS Publications Warehouse

    Anderson, D.R.; Burnham, Kenneth P.; White, Gary C.

    1985-01-01

    (1) The life table model is frequently employed in the analysis of ringer samples of young in bird populations. The basic model is biologically unrealistic and of little use in making inferences concerning age-specific survival probabilities. (2) This model rests on a number of restrictive assumptions, the failure of which causes serious biases. Several important assumptions are not met with real data and the estimators of age-specific survival are not robust enough to these failures. (3) Five major problems in the use of the life table method are reviewed. Examples are provided to illustrate several of the problems involved in using this method in making inferences about survival rates and its age-specific nature. (4) We conclude that this is an invalid procedure and it should not be used. Furthermore, ringing studies involving only young birds are pointless as regards survival estimation because no valid method exists for estimating age-specific or time-specific survival rates from such data. (5) In our view, inferences about age-specific survival rates are possible only if both young and adult (or young, subadult and adult) age classes are ringed each year for k years (k ≥ 2).

  6. Age effects in monetary valuation of reduced mortality risks: the relevance of age-specific hazard rates.

    PubMed

    Leiter, Andrea M

    2011-08-01

    This paper highlights the relevance of age-specific hazard rates in explaining the age variation in "value of statistical life" (VSL) figures. The analysis-which refers to a stated preference framework-contributes to the ongoing discussion of whether benefits resulting from reduced mortality risk should be valued differently depending on the age of the beneficiaries. By focussing on a life-threatening environmental phenomenon I show that the consideration of the individual's age-specific hazard rate is important. If a particular risk affects all individuals regardless of their age so that their hazard rate is age-independent, VSL is rather constant for people at different age; if hazard rate varies with age, VSL estimates are sensitive to age. The results provide an explanation for the mixed outcomes in empirical studies and illustrate in which cases an adjustment to age may or may not be justified. Efficient provision of live-saving measures requires that such differences to be taken into account.

  7. A study of the effects of cause specific death rates on age-specific death rates with special reference to Tamil Nadu.

    PubMed

    Navaneethan, K

    1983-10-01

    The objective of this study is to determine the effect of cause specific death rates on age specific death rates for Tamil Nadu rural females during the period 1970-75 in various age groups. 2 regression lines have been fitted. The age specific death rates were taken as dependent variables and time as an independent variable; the age-cause specific death rates were dependent variables and time was an independent variable. In the analysis, the ratio of regression coefficients of 2 regression lines gives the effect of age specific death rates due to the j-th cause in the i-th group. The trend of mortality in the age groups (0-4) and (5-14) declines over the period 1970-75 and increases in the age groups (15-34), (34-54) and 55 and older. The causes of declining mortality in the 0-4 age group are cough, fever, other clear symptoms and other causes. The %s of contribution for this decline are respectively 14%, 41%, 21% and 72% to the overall decline in that age group. The cause group violence and injury, digestive disorders and causes peculiar to infancy have contributed to increase in the 0-4 age group death rates. Digestive disorders, coughs and other causes have contributed to declining mortality in the 5-14 age group. The cause group accidents and injury, digestive disorders, other clear symptoms, child births and pregnancy and other causes are promoted to increase the mortality of the 15-34 age group. The causes contributing to the increasing trend of mortality in the 35-54 age group are violence and injury, digestive disorders, coughs, other clear symptoms, child births and pregnancy. Digestive disorders and other causes contributed to the mortality increase in the over 55 age group. PMID:12266915

  8. Age-specificity of black-capped chickadee survival rates: Analysis of capture-recapture data

    USGS Publications Warehouse

    Loery, G.; Pollock, K.H.; Nichols, J.D.; Hines, J.E.

    1987-01-01

    The ornithological literature indicates a widespread belief in two generalizations about the age-specificity of avian survival rates: (1) survival rates of young birds for some period following fledging are lower than those of adults, and (2) after reaching adulthood survival rates are constant for birds of all ages. There is a growing body of evidence in support of the first generalization, although little is known about how long the survival difference between young and adults lasts. This latter question can be addressed with capture-recapture or band recovery studies based on birds marked in the winter, but the inability to determine age in many species during winter has prevented the use of standard methods. There is very little evidence supporting the second generalization, and we are in need of methods and actual analyses that address this question. In the present paper we restate the two generalizations as hypotheses and test them using data from a wintering Black-capped Chickadee (Parus atricapillus) population in Connecticut, which has been studied by Loery for 26 yr. We use a cohort-based Jolly-Seber approach, which should be useful in other investigations of this nature. We found strong evidence of lower survival rates in 1st-yr birds than in adults, but could not determine whether this was the result of higher mortality rates, higher emigration rates, or a combination of the two. We also found evidence that survival rates of adult birds were not constant with age but decreased at a rate of ? 3.5%/yr. As adult birds are very faithful to their wintering areas, we believe that almost all this decrease can be attributed to an increase in mortality with age. Simulation results suggest that heterogeneity of capture probabilities could not explain the magnitude of the decrease in survival with age. Age-dependent tag loss is also discussed as an alternative explanation, but is dismissed as very unlikely in this situation. This analysis thus provides some of the

  9. Temporal and spatial variation in age-specific survival rates of a long-lived mammal, the Hawaiian monk seal.

    PubMed

    Baker, Jason D; Thompson, Paul M

    2007-02-01

    Estimates of variability in pinniped survival rates are generally based on observations at single sites, so it is not certain whether observed rates represent the whole population. Here, we provide a comprehensive analysis of spatio-temporal variation in age-specific survival rates for endangered Hawaiian monk seals (Monachus schauinslandi) based on capture-recapture analyses of more than 85% of the pups weaned in this population over the last two decades. Uniquely, these data have been collected from six subpopulations, encompassing all major breeding sites across its 1800 km long core range. Analyses of individual subpopulations revealed similar patterns in age-specific survival, characterized by the relatively low survival rates from weaning to 2 years of age, intermediate rates to 4 years of age, and then by relatively high 'mature' survival rates until 17 years of age, after which a senescent decline was observed. Juvenile, subadult and adult survival rates all varied significantly over time. Trends in survival among subpopulations were coherent with their relative geographical positions, suggesting regional structuring and connectedness within the archipelago. Survival rates for different age classes tended to be positively correlated, suggesting that similar factors may influence the survival for seals of all ages. PMID:17164205

  10. Age- and gender-specific estimates of partnership formation and dissolution rates in the Seattle Sex Survey

    PubMed Central

    Nelson, Sara J.; Hughes, James P.; Foxman, Betsy; Aral, Sevgi O.; Holmes, King K.; White, Peter J.; Golden, Matthew R.

    2009-01-01

    Purpose: Partnership formation and dissolution rates are primary determinants of sexually transmitted infection (STI) transmission dynamics. Methods: The authors used data on persons' lifetime sexual experiences from a 2003-2004 random digit dialing survey of Seattle residents aged 18-39 years (N=1,194) to estimate age- and gender-specific partnership formation and dissolution rates. Partnership start and end dates were used to estimate participants' ages at the start of each partnership and partnership durations, and partnerships not enumerated in the survey were imputed. Results: Partnership formation peaked at age 19 at 0.9 (95% CI: 0.76, 1.04) partnerships per year and decreased to 0.1-0.2 after age 30 for women and peaked at age 20 at 1.4 (95% CI: 1.08, 1.64) and declined to 0.5 after age 30 for men. Nearly a quarter (23.7%) of partnerships ended within 1 week and over one-half (51.2%) ended within 12 weeks. Most (63.5%) individuals aged 30-39 had not formed a new sexual partnership in the past 3 years. Conclusion: A large proportion of the heterosexual population is no longer at substantial STI risk by their early 30s, but similar analyses among high-risk populations may give insight into reasons for the profound disparities in STI rates across populations. PMID:20071193

  11. Using skew-logistic probability density function as a model for age-specific fertility rate pattern.

    PubMed

    Asili, Sahar; Rezaei, Sadegh; Najjar, Lotfollah

    2014-01-01

    Fertility rate is one of the most important global indexes. Past researchers found models which fit to age-specific fertility rates. For example, mixture probability density functions have been proposed for situations with bi-modal fertility patterns. This model is less useful for unimodal age-specific fertility rate patterns, so a model based on skew-symmetric (skew-normal) pdf was proposed by Mazzuco and Scarpa (2011) which was flexible for unimodal and bimodal fertility patterns. In this paper, we introduce skew-logistic probability density function as a better model: its residuals are less than those of the skew-normal model and it can more precisely estimate the parameters of the model. PMID:24967404

  12. Exposure-Specific and Age-Specific Attack Rates for Ebola Virus Disease in Ebola-Affected Households, Sierra Leone

    PubMed Central

    Bower, Hilary; Johnson, Sembia; Bangura, Mohamed S.; Kamara, Alie Joshua; Kamara, Osman; Mansaray, Saidu H.; Sesay, Daniel; Turay, Cecilia; Checchi, Francesco

    2016-01-01

    Using histories of household members of Ebola virus disease (EVD) survivors in Sierra Leone, we calculated risk of EVD by age and exposure level, adjusting for confounding and clustering, and estimated relative risks. Of 937 household members in 94 households, 448 (48%) had had EVD. Highly correlated with exposure, EVD risk ranged from 83% for touching a corpse to 8% for minimal contact and varied by age group: 43% for children <2 years of age; 30% for those 5–14 years of age; and >60% for adults >30 years of age. Compared with risk for persons 20–29 years of age, exposure-adjusted relative risks were lower for those 5–9 (0.70), 10–14 (0.64), and 15–19 (0.71) years of age but not for children <2 (0.92) or 2–4 (0.97) years of age. Lower risk for 5–19-year-olds, after adjustment for exposure, suggests decreased susceptibility in this group. PMID:27144428

  13. Exposure-Specific and Age-Specific Attack Rates for Ebola Virus Disease in Ebola-Affected Households, Sierra Leone.

    PubMed

    Bower, Hilary; Johnson, Sembia; Bangura, Mohamed S; Kamara, Alie Joshua; Kamara, Osman; Mansaray, Saidu H; Sesay, Daniel; Turay, Cecilia; Checchi, Francesco; Glynn, Judith R

    2016-08-01

    Using histories of household members of Ebola virus disease (EVD) survivors in Sierra Leone, we calculated risk of EVD by age and exposure level, adjusting for confounding and clustering, and estimated relative risks. Of 937 household members in 94 households, 448 (48%) had had EVD. Highly correlated with exposure, EVD risk ranged from 83% for touching a corpse to 8% for minimal contact and varied by age group: 43% for children <2 years of age; 30% for those 5-14 years of age; and >60% for adults >30 years of age. Compared with risk for persons 20-29 years of age, exposure-adjusted relative risks were lower for those 5-9 (0.70), 10-14 (0.64), and 15-19 (0.71) years of age but not for children <2 (0.92) or 2-4 (0.97) years of age. Lower risk for 5-19-year-olds, after adjustment for exposure, suggests decreased susceptibility in this group. PMID:27144428

  14. Sex- and age- specific relations between economic development, economic inequality and homicide rates in people aged 0-24 years: a cross-sectional analysis.

    PubMed Central

    Butchart, Alexander; Engström, Karin

    2002-01-01

    OBJECTIVE: To test whether relations between economic development, economic inequality, and child and youth homicide rates are sex- and age-specific, and whether a country's wealth modifies the impact of economic inequality on homicide rates. METHODS: Outcome variables were homicide rates around 1994 in males and females in the age ranges 0-4, 5-9, 10-14, 15-19 and 20-24 years from 61 countries. Predictor variables were per capita gross domestic product (GDP), GINI coefficient, percentage change in per capita gross national product (GNP) and female economic activity as a percentage of male economic activity. Relations were analysed by ordinary least squares regression. FINDINGS: All predictors explained significant variances in homicide rates in those aged 15-24. Associations were stronger for males than females and weak for children aged 0-9. Models that included female economic inequality and percentage change in GNP increased the effect in children aged 0-9 and the explained variance in females aged 20-24. For children aged 0-4, country clustering by income increased the explained variance for both sexes. For males aged 15-24, the association with economic inequality was strong in countries with low incomes and weak in those with high incomes. CONCLUSION: Relations between economic factors and child and youth homicide rates varied with age and sex. Interventions to target economic factors would have the strongest impact on rates of homicide in young adults and late adolescent males. In societies with high economic inequality, redistributing wealth without increasing per capita GDP would reduce homicide rates less than redistributions linked with overall economic development. PMID:12471400

  15. Age-specific vibrissae growth rates: a tool for determining the timing of ecologically important events in Steller sea lions

    USGS Publications Warehouse

    Rea, L.D.; Christ, A.M.; Hayden, A.B.; Stegall, V.K.; Farley, S.D.; Stricker, Craig A.; Mellish, J.E.; Maniscalco, J.M.; Waite, J.N.; Burkanov, V.N.; Pitcher, K.W.

    2015-01-01

    Steller sea lions (SSL; Eumetopias jubatus) grow their vibrissae continually, providing a multiyear record suitable for ecological and physiological studies based on stable isotopes. An accurate age-specific vibrissae growth rate is essential for registering a chronology along the length of the record, and for interpreting the timing of ecologically important events. We utilized four methods to estimate the growth rate of vibrissae in fetal, rookery pup, young-of-the-year (YOY), yearling, subadult, and adult SSL. The majority of vibrissae were collected from SSL live-captured in Alaska and Russia between 2000 and 2013 (n = 1,115), however, vibrissae were also collected from six adult SSL found dead on haul-outs and rookeries during field excursions to increase the sample size of this underrepresented age group. Growth rates of vibrissae were generally slower in adult (0.44 ± 0.15 cm/mo) and subadult (0.61 ± 0.10 cm/mo) SSL than in YOY (0.87 ± 0.28 cm/mo) and fetal (0.73 ± 0.05 cm/mo) animals, but there was high individual variability in these growth rates within each age group. Some variability in vibrissae growth rates was attributed to the somatic growth rate of YOY sea lions between capture events (P = 0.014, r2 = 0.206, n = 29).

  16. What can we learn from the age- and race/ethnicity- specific rates of inflammatory breast carcinoma?

    PubMed

    Il'yasova, Dora; Siamakpour-Reihani, Sharareh; Akushevich, Igor; Akushevich, Lucy; Spector, Neil; Schildkraut, Joellen

    2011-11-01

    Inflammatory Breast Carcinoma (IBC), the most aggressive type of breast tumor with unique clinicopathological presentation, is hypothesized to have distinct etiology with a socioeconomic status (SES) component. Using the Surveillance, Epidemiology and End Results (SEER) Program data for 2004-2007, we compare incidence rates of IBC to non-inflammatory locally advanced breast cancer (LABC) among racial/ethnic groups with different SES. The analysis includes women 20-84 years of age. To examine evidence for the distinct etiology of IBC, we analyzed age-distribution patterns of IBC and non-inflammatory LABC, using a mathematical carcinogenesis model. Based on the Collaborative Staging Extension codes, 2,942 incident IBC cases (codes 71 and 73) and 5,721 non-inflammatory LABC cases (codes 40-62) were identified during the four-year study period. Age-adjusted rates of IBC among non-Hispanic White and Hispanic women were similar (2.5/100,000 in both groups). Similar rates were also found in non-inflammatory LABC in these two groups (4.8/100,000 and 4.2/100,000, respectively). In African-American women, the IBC (3.91/100,000) and non-inflammatory LABC (8.47/100,000) rates were greater compared with other ethnic/racial sub-groups. However, the ratio of rates of IBC/non-inflammatory LABC was similar among all the racial/ethnic groups, suggesting that African-American women are susceptible to aggressive breast tumors in general but not specifically to IBC. The mathematical model successfully predicted the observed age-specific rates of both examined breast tumors and revealed distinct patterns. IBC rates increased until age 65 and then slightly decreased, whereas non-inflammatory LABC rates steadily increased throughout the entire age interval. The number of critical transition carcinogenesis stages (m-stages) predicted by the model were 6.3 and 8.5 for IBC and non-inflammatory LABC, respectively, supporting different etiologies of these breast tumors.

  17. Correlation between Age and Education Specific In and Out Migration Rates.

    ERIC Educational Resources Information Center

    Voth, Donald E.; Ramey, Kevin

    Although in-migration and out-migration levels of communities or counties are usually positively correlated, little work has been done on the correlation between in-migration and out-migration within population subcategories. Using a special 1980 data source from the U.S. Census Bureau, this paper examines migration patterns in 30 age/education…

  18. Conners' Teacher Rating Scale for Preschool Children: A Revised, Brief, Age-Specific Measure

    ERIC Educational Resources Information Center

    Purpura, David J.; Lonigan, Christopher J.

    2009-01-01

    The Conners' Teacher Rating Scale-Revised (CTRS-R) is one of the most commonly used measures of child behavior problems. However, the scale length and the appropriateness of some of the items on the scale may reduce the usefulness of the CTRS-R for use with preschoolers. In this study, a Graded Response Model analysis based on Item Response Theory…

  19. Age-specific and age-standardised incidence rates for intraoral squamous cell carcinoma in blacks on the Witwatersrand, South Africa.

    PubMed

    Altini, M; Kola, A H

    1985-12-01

    All new cases of intraoral squamous cell carcinoma which occurred in Blacks resident on the Witwatersrand during the 10-yr period 1971-80 were traced by examining the records of all the hospital pathology departments in this area. The population at risk at the mid-point of the study (1975) was calculated from the National Population Censuses of 1970 and 1980, and consisted of 1125960 men and 880269 women. Age-specific incidence rates and age-standardised incidence rates were calculated for each intraoral site for men and women. In the latter calculation a standard World population was used. All rates are expressed as average number of cases per 100000 population per annum. The age-specific incidence rates and age-standardised incidence rates (in brackets) for men and women respectively are: tongue, 1.43 and 0.26 (2.69 and 0.41); gingiva and alveolar ridge, 0.04 and 0.01 (0.07 and 0.01); floor of mouth, 0.87 and 0.22 (1.64 and 0.38); buccal mucosa, 0.05 and 0.04 (0.13 and 0.05); hard and soft palate, 0.34 and 0.05 (0.63 and 0.08). There appears to have been an increase in the incidence of intraoral cancer in Black South Africans since the first survey in 1953-55, which can probably be ascribed to the urbanization process. In Europe, North America and in other population groups in South Africa, the palate is least frequently affected. In contrast, in Black South Africans lesions of the palate are much more common, being less frequent only than tongue and floor of mouth lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Age-Specific Incidence Rates for Dementia and Alzheimer Disease in NIA-LOAD/NCRAD and EFIGA Families

    PubMed Central

    Vardarajan, Badri N.; Faber, Kelley M.; Bird, Thomas D.; Bennett, David A.; Rosenberg, Roger; Boeve, Bradley F.; Graff-Radford, Neill R.; Goate, Alison M.; Farlow, Martin; Sweet, Robert A.; Lantigua, Rafael; Medrano, Martin Z.; Ottman, Ruth; Schaid, Daniel J.; Foroud, Tatiana M.; Mayeux, Richard

    2014-01-01

    IMPORTANCE Late-onset Alzheimer disease (LOAD), defined as onset of symptoms after age 65 years, is the most common form of dementia. Few reports investigate incidence rates in large family-based studies in which the participants were selected for family history of LOAD. OBJECTIVE To determine the incidence rates of dementia and LOAD in unaffected members in the National Institute on Aging Genetics Initiative for Late-Onset Alzheimer Disease/National Cell Repository for Alzheimer Disease (NIA-LOAD/NCRAD) and Estudio Familiar de Influencia Genetica en Alzheimer (EFIGA) family studies. DESIGN, SETTING, AND PARTICIPANTS Families with 2 or more affected siblings who had a clinical or pathological diagnosis of LOAD were recruited as a part of the NIA-LOAD/NCRAD Family Study. A cohort of Caribbean Hispanics with familial LOAD was recruited in a different study at the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain in New York and from clinics in the Dominican Republic as part of the EFIGA study. MAIN OUTCOMES AND MEASURES Age-specific incidence rates of LOAD were estimated in the unaffected family members in the NIA-LOAD/NCRAD and EFIGA data sets. We restricted analyses to families with follow-up and complete phenotype information, including 396 NIA-LOAD/NCRAD and 242 EFIGA families. Among the 943 at-risk family members in the NIA-LOAD/NCRAD families, 126 (13.4%) developed dementia, of whom 109 (86.5%) met criteria for LOAD. Among 683 at-risk family members in the EFIGA families, 174 (25.5%) developed dementia during the study period, of whom 145 (83.3%) had LOAD. RESULTS The annual incidence rates of dementia and LOAD in the NIA-LOAD/NCRAD families per person-year were 0.03 and 0.03, respectively, in participants aged 65 to 74 years; 0.07 and 0.06, respectively, in those aged 75 to 84 years; and 0.08 and 0.07, respectively, in those 85 years or older. Incidence rates in the EFIGA families were slightly higher, at 0.03 and 0.02, 0.06 and 0.05, 0

  1. Age specific survival rates of Steller sea lions at rookeries with divergent population trends in the Russian Far East.

    PubMed

    Altukhov, Alexey V; Andrews, Russel D; Calkins, Donald G; Gelatt, Thomas S; Gurarie, Eliezer D; Loughlin, Thomas R; Mamaev, Evgeny G; Nikulin, Victor S; Permyakov, Peter A; Ryazanov, Sergey D; Vertyankin, Vladimir V; Burkanov, Vladimir N

    2015-01-01

    After a dramatic population decline, Steller sea lions have begun to recover throughout most of their range. However, Steller sea lions in the Western Aleutians and Commander Islands are continuing to decline. Comparing survival rates between regions with different population trends may provide insights into the factors driving the dynamics, but published data on vital rates have been extremely scarce, especially in regions where the populations are still declining. Fortunately, an unprecedented dataset of marked Steller sea lions at rookeries in the Russian Far East is available, allowing us to determine age and sex specific survival in sea lions up to 22 years old. We focused on survival rates in three areas in the Russian range with differing population trends: the Commander Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery) and the Kuril Islands (four rookeries). Survival rates differed between these three regions, though not necessarily as predicted by population trends. Pup survival was higher where the populations were declining (Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island rookeries. The lowest adult (> 3 years old) female survival was found on Medny Island and this may be responsible for the continued population decline there. However, the highest adult survival was found at Kozlov Cape, not in the Kuril Islands where the population is increasing, so we suggest that differences in birth rates might be an important driver of these divergent population trends. High pup survival on the Commander Islands and Kamchatka Coast may be a consequence of less frequent (e.g. biennial) reproduction there, which may permit females that skip birth years to invest more in their offspring, leading to higher pup survival, but this hypothesis awaits measurement of birth rates in these areas.

  2. Age Specific Survival Rates of Steller Sea Lions at Rookeries with Divergent Population Trends in the Russian Far East

    PubMed Central

    Altukhov, Alexey V.; Andrews, Russel D.; Calkins, Donald G.; Gelatt, Thomas S.; Gurarie, Eliezer D.; Loughlin, Thomas R.; Mamaev, Evgeny G.; Nikulin, Victor S.; Permyakov, Peter A.; Ryazanov, Sergey D.; Vertyankin, Vladimir V.; Burkanov, Vladimir N.

    2015-01-01

    After a dramatic population decline, Steller sea lions have begun to recover throughout most of their range. However, Steller sea lions in the Western Aleutians and Commander Islands are continuing to decline. Comparing survival rates between regions with different population trends may provide insights into the factors driving the dynamics, but published data on vital rates have been extremely scarce, especially in regions where the populations are still declining. Fortunately, an unprecedented dataset of marked Steller sea lions at rookeries in the Russian Far East is available, allowing us to determine age and sex specific survival in sea lions up to 22 years old. We focused on survival rates in three areas in the Russian range with differing population trends: the Commander Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery) and the Kuril Islands (four rookeries). Survival rates differed between these three regions, though not necessarily as predicted by population trends. Pup survival was higher where the populations were declining (Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island rookeries. The lowest adult (> 3 years old) female survival was found on Medny Island and this may be responsible for the continued population decline there. However, the highest adult survival was found at Kozlov Cape, not in the Kuril Islands where the population is increasing, so we suggest that differences in birth rates might be an important driver of these divergent population trends. High pup survival on the Commander Islands and Kamchatka Coast may be a consequence of less frequent (e.g. biennial) reproduction there, which may permit females that skip birth years to invest more in their offspring, leading to higher pup survival, but this hypothesis awaits measurement of birth rates in these areas. PMID:26016772

  3. Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and metropolitan Atlanta, 1970-1989.

    PubMed Central

    Huether, C A; Ivanovich, J; Goodwin, B S; Krivchenia, E L; Hertzberg, V S; Edmonds, L D; May, D S; Priest, J H

    1998-01-01

    Our primary objective was to estimate, by one year and five year intervals, maternal age specific risk rates for Down syndrome among whites and among other races from two different populations, metropolitan Atlanta and south west Ohio, using live birth and prenatally diagnosed cases ascertained during 1970-1989. The five year estimates were also calculated separately for each of the five four year periods during these 20 years. Additionally, we compared two different methods of estimating these risk rates by using a third population of whites, and compared two different statistical methods of smoothing the risk rates. The results indicate good agreement between the metropolitan Atlanta and south west Ohio estimates within races, but show a statistically significant difference between the two race categories. Because 86% of live births in the "other races" category in the combined population are to blacks, these data may be seen as the first estimates of maternal age specific risk rates for Down syndrome among blacks calculated by one year intervals. We found excellent agreement in the risk rate estimates among the five four year time periods, between the estimates obtained by using the two different methods of estimation, and between the estimates obtained using the two different methods of statistical smoothing. Our estimated risk rates for white women in their 20s strongly reinforce those from previous studies currently being used for genetic counselling purposes. While we did find somewhat higher rates for women under 20, and increasingly higher rates for those over 30 years of age, these differences are not substantial. Thus, this study in general supports the risk rates estimated from data collected mostly during the 1960s and 1970s. PMID:9643290

  4. Predictive intervals for age-specific fertility.

    PubMed

    Keilman, N; Pham, D Q

    2000-03-01

    A multivariate ARIMA model is combined with a Gamma curve to predict confidence intervals for age-specific birth rates by 1-year age groups. The method is applied to observed age-specific births in Norway between 1900 and 1995, and predictive intervals are computed for each year up to 2050. The predicted two-thirds confidence intervals for Total Fertility (TF) around 2010 agree well with TF errors in old population forecasts made by Statistics Norway. The method gives useful predictions for age-specific fertility up to the years 2020-30. For later years, the intervals become too wide. Methods that do not take into account estimation errors in the ARIMA model coefficients underestimate the uncertainty for future TF values. The findings suggest that the margin between high and low fertility variants in official population forecasts for many Western countries are too narrow. PMID:12158991

  5. Observational, longitudinal study of delirium in consecutive unselected acute medical admissions: age-specific rates and associated factors, mortality and re-admission

    PubMed Central

    Pendlebury, ST; Lovett, NG; Smith, SC; Dutta, N; Bendon, C; Lloyd-Lavery, A; Mehta, Z; Rothwell, PM

    2015-01-01

    Objectives We aimed to determine age-specific rates of delirium and associated factors in acute medicine, and the impact of delirium on mortality and re-admission on long-term follow-up. Design Observational study. Consecutive patients over two 8-week periods (2010, 2012) were screened for delirium on admission, using the confusion assessment method (CAM), and reviewed daily thereafter. Delirium diagnosis was made using the Diagnostic and Statistical Manual Fourth Edition (DSM IV) criteria. For patients aged ≥65 years, potentially important covariables identified in previous studies were collected with follow-up for death and re-admission until January 2014. Participants 503 consecutive patients (age median=72, range 16–99 years, 236 (48%) male). Setting Acute general medicine. Results Delirium occurred in 101/503 (20%) (71 on admission, 30 during admission, 17 both), with risk increasing from 3% (6/195) at <65 years to 14% (10/74) for 65–74 years and 36% (85/234) at ≥75 years (p<0.0001). Among 308 patients aged >65 years, after adjustment for age, delirium was associated with previous falls (OR=2.47, 95% CI 1.45 to 4.22, p=0.001), prior dementia (2.08, 1.10 to 3.93, p=0.024), dependency (2.58, 1.48 to 4.48, p=0.001), low cognitive score (5.00, 2.50 to 9.99, p<0.0001), dehydration (3.53, 1.91 to 6.53, p<0.0001), severe illness (1.98, 1.17 to 3.38, p=0.011), pressure sore risk (5.56, 2.60 to 11.88, p<0.0001) and infection (4.88, 2.85 to 8.36, p<0.0001). Patients with delirium were more likely to fall (OR=4.55, 1.47 to 14.05, p=0.008), be incontinent of urine (3.76, 2.15 to 6.58, p<0.0001) or faeces (3.49, 1.81–6.73, p=0.0002) and be catheterised (5.08, 2.44 to 10.54, p<0.0001); and delirium was associated with stay >7 days (2.82, 1.68 to 4.75, p<0.0001), death (4.56, 1.71 to 12.17, p=0.003) and an increase in dependency among survivors (2.56, 1.37 to 4.76, p=0.003) with excess mortality still evident at 2-year follow-up. Patients with

  6. Differential effect of age, gender and puberty on bone formation rate assessed by measurement of bone-specific alkaline phosphatase in healthy Italian children and adolescents.

    PubMed

    Mora, Stefano; Cafarelli, Laura; Erba, Paola; Puzzovio, Maria; Zamproni, Ilaria; Giacomet, Vania; Viganò, Alessandra

    2009-01-01

    Bones undergo intensive modeling during growth, a process involving both formation and resorption processes. Bone formation can be accurately monitored by measurements of bone-specific alkaline phosphatase (BAP) in serum. The lack of appropriate reference values has hampered the use of BAP in pediatric subjects. The purposes of the present study were to verify the effect of age, gender, and puberty on BAP concentration in healthy children, and to generate reference curves. Morning blood samples were collected from 239 healthy children and adolescents (113 boys), aged 4.5-20.9 years. Anthropometric measurements and pubertal stage were recorded. Blood samples were also obtained from 37 healthy young adults (13 men), aged 21.5-30.2 years. BAP concentration varied significantly with age, showing a peak at age 10-12 years in girls and 12-14 years in boys. Prepubertal concentration of BAP was six- to sevenfold higher than in healthy adults. We observed significantly higher BAP values at the beginning of puberty (stage II) compared to prepubertal stage in both sexes. The effect of puberty was independent from age and gender. We demonstrated that BAP serum concentration varies with age in children and adolescents, and we provided equations to calculate reference values. Because BAP concentrations vary markedly according to the pubertal stage, the values of BAP obtained in single patients should be compared to reference considering not only age and sex, but also the stage of pubertal development.

  7. Age-specific breeding in Emperor Geese

    USGS Publications Warehouse

    Schmutz, J.A.

    2000-01-01

    I studied the frequency with which Emperor Geese (Chen canagica) of known age were observed breeding on the Yukon-Kuskokwim Delta, Alaska. No one- or two-year old geese were observed on nests. Three-year old geese bred at a lower rate than four-year old geese. These data suggest that patterns of age-specific breeding in Emperor Geese are similar to other sympatrically nesting, large bodied geese [Greater White-fronted Geese (Anser albifrons)] but delayed relative to smaller bodied geese [Cackling Canada Geese (Branta canadensis minima) and Pacific Black Brant (B. bernicla nigricans)].

  8. Investigating the Effect of Social Changes on Age-Specific Gun-Related Homicide Rates in New York City During the 1990s

    PubMed Central

    Messner, Steven F.; Tracy, Melissa; Vlahov, David; Goldmann, Emily; Tardiff, Kenneth J.; Galea, Sandro

    2010-01-01

    Objectives. We assessed whether New York City's gun-related homicide rates in the 1990s were associated with a range of social determinants of homicide rates. Methods. We used cross-sectional time-series data for 74 New York City police precincts from 1990 through 1999, and we estimated Bayesian hierarchical models with a spatial error term. Homicide rates were estimated separately for victims aged 15–24 years (youths), 25–34 years (young adults), and 35 years or older (adults). Results. Decreased cocaine consumption was associated with declining homicide rates in youths (posterior median [PM] = 0.25; 95% Bayesian confidence interval [BCI] = 0.07, 0.45) and adults (PM = 0.07; 95% BCI = 0.02, 0.12), and declining alcohol consumption was associated with fewer homicides in young adults (PM = 0.14; 95% BCI = 0.02, 0.25). Receipt of public assistance was associated with fewer homicides for young adults (PM = –104.20; 95% BCI = –182.0, –26.14) and adults (PM = –28.76; 95% BCI = –52.65, –5.01). Misdemeanor policing was associated with fewer homicides in adults (PM = –0.01; 95% BCI = –0.02, –0.001). Conclusions. Substance use prevention policies and expansion of the social safety net may be able to cause major reductions in homicide among age groups that drive city homicide trends. PMID:20395590

  9. Cancer-specific incidence rates of tuberculosis

    PubMed Central

    Seo, Gi Hyeon; Kim, Min Jae; Seo, Soyoung; Hwang, Boram; Lee, Eugene; Yun, Yujin; Choi, Minsun; Kim, Moonsuk; Kim, Jin Won; Kim, Eu Suk; Kim, Hong Bin; Song, Kyoung-Ho

    2016-01-01

    Abstract Population-based studies of the incidence of tuberculosis in cancer patients according to the type of cancer are limited. We investigated the cancer-specific incidence of tuberculosis in a nationwide population-based cohort in a country with an intermediate burden of tuberculosis. We used mandatory National Health Insurance claims data to construct a cancer cohort of adults (aged 20–99 years) with newly diagnosed malignancies other than lung cancer, from January 2008 to December 2012. Patients who developed tuberculosis in this period were identified in the cancer cohort and the general population. Standardized incidence ratios (SIRs) of tuberculosis in the cancer cohort according to type of cancer and time after cancer diagnosis were calculated by comparing the observed incidence rates with those inferred from the age- and gender-specific incidence rates in the general population. A total of 855,382 cancer patients and 1589,876 person-years (py) were observed. A total of 5745 patients developed tuberculosis; the mean incidence rate was 361.3 per 100,000 py, and the SIR was 2.22 (95% confidence interval [CI], 2.17–2.27). The incidence rate was highest for hematologic malignancy and lowest for thyroid cancer. It was also highest as 650.1 per 100,000 py, with SIR of 3.70 (CI, 3.57–3.83) for the first 6 months after diagnosis of malignancy and then declined. However, it still remained higher than that of the general population after 24 months (SIR = 1.43, CI, 1.36–1.51). The incidence of tuberculosis increases after diagnosis in patients with malignancies. The risk of tuberculosis differs according to the type of cancer and remains elevated even 24 months after cancer diagnosis. Tuberculosis should be considered an important comorbidity in patients with malignancies. PMID:27661041

  10. Estimating Stage-Specific Vital Rate Responses to Stress within Mixed Age Populations of the Opossum Shrimp Americamysis Bahia Using Digital Imaging (NAC SETAC 2011)

    EPA Science Inventory

    Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

  11. Estimating Stage Specific Vital Rate Responses to Stress Within Mixed Age Populations of the Opossum Shrimp Americamysis bahia Using Digital Imaging

    EPA Science Inventory

    Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

  12. Global and Specific Ratings: Are They Related?

    ERIC Educational Resources Information Center

    Goodwin, Stephanie S.; Raths, James

    The purpose of this study was to determine if making specific changes in teaching, changes that were validated by experts, would change the overall student ratings of instructors. Thirty graduate teaching assistants who participated in a workshop on improving lecturing skills significantly improved their scores on specific lecturing behaviors that…

  13. Antioxidants, metabolic rate and aging in Drosophila

    NASA Technical Reports Server (NTRS)

    Miquel, J.; Fleming, J.; Economos, A. C.

    1982-01-01

    The metabolic rate-of-living theory of aging was investigated by determining the effect of several life-prolonging antioxidants on the metabolic rate and life span of Drosophila. The respiration rate of groups of continuously agitated flies was determined in a Gilson respirometer. Vitamin E, 2,4-dinitrophenol, nordihydroguaiaretic acid, and thiazolidine carboxylic acid were employed as antioxidants. Results show that all of these antioxidants reduced the oxygen consumption rate and increased the mean life span, and a significant negative linear correlation was found between the mean life span and the metabolic rate. It is concluded that these findings indicate that some antioxidants may inhibit respiration rate in addition to their protective effect against free radical-induced cellular damage.

  14. Effects of age on speech and voice quality ratings.

    PubMed

    Goy, Huiwen; Kathleen Pichora-Fuller, M; van Lieshout, Pascal

    2016-04-01

    The quality of communication may be affected by listeners' perception of talkers' characteristics. This study examined if there were effects of talker and listener age on the perception of speech and voice qualities. Younger and older listeners judged younger and older talkers' gender and age, then rated speech samples on pleasantness, naturalness, clarity, ease of understanding, loudness, and the talker's suitability to be an audiobook reader. For the same talkers, listeners also rated voice samples on pleasantness, roughness, and power. Younger and older talkers were perceived to be similar on most qualities except age. Younger and older listeners rated talkers similarly, except that younger listeners perceived younger voices to be more pleasant and less rough than older voices. For vowel samples, younger listeners were more accurate than older listeners at age estimation, while older listeners were more accurate than younger listeners at gender identification, suggesting that younger and older listeners differ in their evaluation of specific talker characteristics. Thus, the perception of quality was generally more affected by the age of the listener than the age of the talker, and age-related differences between listeners depended on whether voice or speech samples were used and the rating being made. PMID:27106312

  15. Articulation rate across dialect, age, and gender.

    PubMed

    Jacewicz, Ewa; Fox, Robert A; O'Neill, Caitlin; Salmons, Joseph

    2009-07-01

    The understanding of sociolinguistic variation is growing rapidly, but basic gaps still remain. Whether some languages or dialects are spoken faster or slower than others constitutes such a gap. Speech tempo is interconnected with social, physical and psychological markings of speech. This study examines regional variation in articulation rate and its manifestations across speaker age, gender and speaking situations (reading vs. free conversation). The results of an experimental investigation show that articulation rate differs significantly between two regional varieties of American English examined here. A group of Northern speakers (from Wisconsin) spoke significantly faster than a group of Southern speakers (from North Carolina). With regard to age and gender, young adults read faster than older adults in both regions; in free speech, only Northern young adults spoke faster than older adults. Effects of gender were smaller and less consistent; men generally spoke slightly faster than women. As the body of work on the sociophonetics of American English continues to grow in scope and depth, we argue that it is important to include fundamental phonetic information as part of our catalog of regional differences and patterns of change in American English.

  16. Age-specific transcriptional response to stroke.

    PubMed

    Sieber, Matthias W; Guenther, Madlen; Jaenisch, Nadine; Albrecht-Eckardt, Daniela; Kohl, Matthias; Witte, Otto W; Frahm, Christiane

    2014-07-01

    Increased age is a major risk factor for stroke incidence and post-ischemic mortality. To develop age-adjusted therapeutic interventions, a clear understanding of the complexity of age-related post-ischemic mechanisms is essential. Transient occlusion of the middle cerebral artery--a model that closely resembles human stroke--was used to induce cerebral infarction in mice of 4 different ages (2, 9, 15, 24 months). By using Illumina cDNA microarrays and quantitative PCR we detected a distinct age-dependent response to stroke involving 350 differentially expressed genes. Our analyses also identified 327 differentially expressed genes that responded to stroke in an age-independent manner. These genes are involved in different aspects of the inflammatory and immune response, oxidative stress, cell cycle activation and/or DNA repair, apoptosis, cytoskeleton reorganization and/or astrogliosis, synaptic plasticity and/or neurotransmission, and depressive disorders and/or dopamine-, serotonin-, GABA-signaling. In agreement with our earlier work, aged brains displayed an attenuated inflammatory and immune response (Sieber et al., 2011) and a reduced impairment of post-stroke synaptic plasticity. Our data also revealed a distinct age-related susceptibility for post-ischemic depression, the most common neuropsychiatric consequence of stroke, which has a major influence on functional outcome.

  17. Specific Impulse and Mass Flow Rate Error

    NASA Technical Reports Server (NTRS)

    Gregory, Don A.

    2005-01-01

    Specific impulse is defined in words in many ways. Very early in any text on rocket propulsion a phrase similar to .specific impulse is the thrust force per unit propellant weight flow per second. will be found.(2) It is only after seeing the mathematics written down does the definition mean something physically to scientists and engineers responsible for either measuring it or using someone.s value for it.

  18. California Divorce Rates by Age at First Marriage and Duration of First Marriage

    ERIC Educational Resources Information Center

    Schoen, Robert

    1975-01-01

    The proposition that age at first marriage is inversely related to the risk of divorce was examined by means of detailed age-duration-specific divorce rates for California 1969. A strong inverse relationship was found for male ages at marriage 18 through 25 and female ages at marriage 16 through 24. (Author)

  19. Antidepressant Prescription and Suicide Rates: Effect of Age and Gender

    ERIC Educational Resources Information Center

    Kalmar, Sandor; Szanto, Katalin; Rihmer, Zoltan; Mazumdar, Sati; Harrison, Katrin; Mann, J. John

    2008-01-01

    To determine whether the effect of antidepressant exposure on suicide rate is modified by age and gender in Hungary, annual antidepressant prescription rates and suicide rates of about 10 million inhabitants between 1999-2005 were analyzed by age and gender groups. The suicide rate was inversely related to the increased use of antidepressants in…

  20. Peroxisomes, cell senescence, and rates of aging.

    PubMed

    Giordano, Courtney R; Terlecky, Stanley R

    2012-09-01

    The peroxisome is functionally integrated into an exquisitely complex network of communicating endomembranes which is only beginning to be appreciated. Despite great advances in identifying essential components and characterizing molecular mechanisms associated with the organelle's biogenesis and function, there is a large gap in our understanding of how peroxisomes are incorporated into metabolic pathways and subcellular communication networks, how they contribute to cellular aging, and where their influence is manifested on the initiation and progression of degenerative disease. In this review, we summarize recent evidence pointing to the organelle as an important regulator of cellular redox balance with potentially far-reaching effects on cell aging and the genesis of human disease. The roles of the organelle in lipid homeostasis, anaplerotic reactions, and other critical metabolic and biochemical processes are addressed elsewhere in this volume. This article is part of a Special Issue entitled: Metabolic Functions and Biogenesis of Peroxisomes in Health and Disease.

  1. Antidepressant prescription and suicide rates: effect of age and gender.

    PubMed

    Kalmar, Sandor; Szanto, Katalin; Rihmer, Zoltan; Mazumdar, Sati; Harrison, Katrin; Mann, J John

    2008-08-01

    To determine whether the effect of antidepressant exposure on suicide rate is modified by age and gender in Hungary, annual antidepressant prescription rates and suicide rates of about 10 million inhabitants between 1999-2005 were analyzed by age and gender groups. The suicide rate was inversely related to the increased use of antidepressants in both genders. The strongest association was found in the oldest age groups, where the increase in antidepressant use was highest, while there was no association in the under 20 or 50-69 age groups in either gender. Antidepressant prescription rate was related to suicide rate after controlling for divorce rate or unemployment rate, but not after controlling for alcohol consumption rate.

  2. Age-adjusted Labor Force Participation Rates, 1960-2045.

    ERIC Educational Resources Information Center

    Szafran, Robert F.

    2002-01-01

    A proposed new age-adjusted measure for calculating labor force participation rate eliminates the effect of changes in the age distribution. According to the new criterion, increases in women's labor force participation from 1960-2000 would have been even greater of shifts in the age distribution had not occurred. (Contains 12 references.) (JOW)

  3. Effect of Age and Other Factors on Maximal Heart Rate.

    ERIC Educational Resources Information Center

    Londeree, Ben R.; Moeschberger, Melvin L.

    1982-01-01

    To reduce confusion regarding reported effects of age on maximal exercise heart rate, a comprehensive review of the relevant English literature was conducted. Data on maximal heart rate after exercising with a bicycle, a treadmill, and after swimming were analyzed with regard to physical fitness and to age, sex, and racial differences. (Authors/PP)

  4. Some Statistical Properties of Item Specificity in Student Ratings.

    ERIC Educational Resources Information Center

    Brandenburg, Dale C.

    Prior research has indicated that items administered to college students for rating their instructors, can be empirically as well as logically classified on a continuum from very general to specific. Three of these hypothesized classifications of item specificity--global, general concept, and specific--were chosen to represent this continuum.…

  5. Impact of age and basic heart rate on heart rate turbulence in healthy persons.

    PubMed

    Schwab, Jörg Otto; Eichner, Gerrit; Shlevkov, Nikolay; Schrickel, Jan; Yang, Alexander; Balta, Osman; Lewalter, Thorsten; Lüderitz, Berndt

    2005-01-01

    Postextrasystolic acceleration of heart rate (HR), known as HR turbulence (HRT) is attenuated in patients with coronary artery disease at increased risk of adverse events. The influence of age and basic HR on HRT have not been evaluated in a large cohort of persons. In 95 healthy individuals, HRT onset (TO) and slope (TS) were calculated from 24-hour ambulatory electrocardiograms, as well as the turbulence timing (TT). Gender specific differences in TO and TS were compared in simple, linear, weighted regression model. The influence of age and the basic HR preceding ventricular premature contractions on HRT were examined. We found that, in men and women, TO decreases as basic HR increases (P < 0.01). In contrast, in men, TS decreased as basic HR increases, whereas in women, basic HR influenced TS only slightly (P < 0.01). A multiple, linear regression model revealed a decrease in HRT with increasing age in men. In conclusion, physiological acceleration of the HR within the first 11 beats after premature ventricular complex (VPC) was observed in >75% of healthy individuals. An accelerating HR preceding the VPC influenced HRT in men. An increasing age was associated with a decrease in HRT in men and a decrease in TO in women. These results illustrate the importance of physiological modulations of HRT when used for risk stratification, especially in older populations.

  6. Specific premature epigenetic aging of cartilage in osteoarthritis

    PubMed Central

    Vidal-Bralo, Laura; Lopez-Golan, Yolanda; Mera-Varela, Antonio; Rego-Perez, Ignacio; Horvath, Steve; Zhang, Yuhua; del Real, Álvaro; Zhai, Guangju; Blanco, Francisco J; Riancho, Jose A.; Gomez-Reino, Juan J; Gonzalez, Antonio

    2016-01-01

    Osteoarthritis (OA) is a disease affecting multiple tissues of the joints in the elderly, but most notably articular cartilage. Premature biological aging has been described in this tissue and in blood cells, suggesting a systemic component of premature aging in the pathogenesis of OA. Here, we have explored epigenetic aging in OA at the local (cartilage and bone) and systemic (blood) levels. Two DNA methylation age-measures (DmAM) were used: the multi-tissue age estimator for cartilage and bone; and a blood-specific biomarker for blood. Differences in DmAM between OA patients and controls showed an accelerated aging of 3.7 years in articular cartilage (95 % CI = 1.1 to 6.3, P = 0.008) of OA patients. By contrast, no difference in epigenetic aging was observed in bone (0.04 years; 95 % CI = −1.8 to 1.9, P = 0.3) and in blood (−0.6 years; 95 % CI = −1.5 to 0.3, P = 0.2) between OA patients and controls. Therefore, premature epigenetic aging according to DNA methylation changes was specific of OA cartilage, adding further evidence and insight on premature aging of cartilage as a component of OA pathogenesis that reflects damage and vulnerability. PMID:27689435

  7. Estimating survival rates with time series of standing age-structure data.

    PubMed

    Udevitz, Mark S; Gogan, Peter J P

    2012-04-01

    It has long been recognized that age-structure data contain useful information for assessing the status and dynamics of wildlife populations. For example, age-specific survival rates can be estimated with just a single sample from the age distribution of a stable, stationary population. For a population that is not stable, age-specific survival rates can be estimated using techniques such as inverse methods that combine time series of age-structure data with other demographic data. However, estimation of survival rates using these methods typically requires numerical optimization, a relatively long time series of data, and smoothing or other constraints to provide useful estimates. We developed general models for possibly unstable populations that combine time series of age-structure data with other demographic data to provide explicit maximum likelihood estimators of age-specific survival rates with as few as two years of data. As an example, we applied these methods to estimate survival rates for female bison (Bison bison) in Yellowstone National Park, USA. This approach provides a simple tool for monitoring survival rates based on age-structure data.

  8. Estimating survival rates with time series of standing age-structure data

    USGS Publications Warehouse

    Udevitz, Mark S.; Gogan, Peter J.

    2014-01-01

    It has long been recognized that age-structure data contain useful information for assessing the status and dynamics of wildlife populations. For example, age-specific survival rates can be estimated with just a single sample from the age distribution of a stable, stationary population. For a population that is not stable, age-specific survival rates can be estimated using techniques such as inverse methods that combine time series of age-structure data with other demographic data. However, estimation of survival rates using these methods typically requires numerical optimization, a relatively long time series of data, and smoothing or other constraints to provide useful estimates. We developed general models for possibly unstable populations that combine time series of age-structure data with other demographic data to provide explicit maximum likelihood estimators of age-specific survival rates with as few as two years of data. As an example, we applied these methods to estimate survival rates for female bison (Bison bison) in Yellowstone National Park, USA. This approach provides a simple tool for monitoring survival rates based on age-structure data.

  9. Growing Fixed With Age: Lay Theories of Malleability Are Target Age-Specific.

    PubMed

    Neel, Rebecca; Lassetter, Bethany

    2015-11-01

    Beliefs about whether people can change ("lay theories" of malleability) are known to have wide-ranging effects on social motivation, cognition, and judgment. Yet rather than holding an overarching belief that people can or cannot change, perceivers may hold independent beliefs about whether different people are malleable-that is, lay theories may be target-specific. Seven studies demonstrate that lay theories are target-specific with respect to age: Perceivers hold distinct, uncorrelated lay theories of people at different ages, and younger targets are considered to be more malleable than older targets. Both forms of target-specificity are consequential, as target age-specific lay theories predict policy support for learning-based senior services and the rehabilitation of old and young drug users. The implications of target age-specific lay theories for a number of psychological processes, the social psychology of aging, and theoretical frameworks of malleability beliefs are discussed.

  10. Aging and the rate of visual information processing.

    PubMed

    Guest, Duncan; Howard, Christina J; Brown, Louise A; Gleeson, Harriet

    2015-01-01

    Multiple methods exist for measuring how age influences the rate of visual information processing. The most advanced methods model the processing dynamics in a task in order to estimate processing rates independently of other factors that might be influenced by age, such as overall performance level and the time at which processing onsets. However, such modeling techniques have produced mixed evidence for age effects. Using a time-accuracy function (TAF) analysis, Kliegl, Mayr, and Krampe (1994) showed clear evidence for age effects on processing rate. In contrast, using the diffusion model to examine the dynamics of decision processes, Ratcliff and colleagues (e.g., Ratcliff, Thapar, & McKoon, 2006) found no evidence for age effects on processing rate across a range of tasks. Examination of these studies suggests that the number of display stimuli might account for the different findings. In three experiments we measured the precision of younger and older adults' representations of target stimuli after different amounts of stimulus exposure. A TAF analysis found little evidence for age differences in processing rate when a single stimulus was presented (Experiment 1). However, adding three nontargets to the display resulted in age-related slowing of processing (Experiment 2). Similar slowing was observed when simply presenting two stimuli and using a post-cue to indicate the target (Experiment 3). Although there was some interference from distracting objects and from previous responses, these age-related effects on processing rate seem to reflect an age-related difficulty in processing multiple objects, particularly when encoding them into visual working memory. PMID:26473319

  11. The estimation of age-related rates of infection from case notifications and serological data.

    PubMed Central

    Grenfell, B. T.; Anderson, R. M.

    1985-01-01

    The paper describes a maximum-likelihood method for the estimation of age-related changes in the per capita rate of infection, from case notification records or serological data. The methods are applied to records of measles incidence in the UK and USA, for which the estimated rates of infection tend to rise to a maximum value at around 10 years of age and then to decline in the older age-classes. Longer-term and seasonal trends are analysed by reference to changes in the estimated average age at infection; a statistic derived from a knowledge of the age-specific rates of infection. Future data needs in the epidemiological study of directly transmitted viral and bacterial diseases are discussed with reference to the detection and interpretation of age-dependent rates of disease transmission. PMID:4067297

  12. Age and gender specific biokinetic model for strontium in humans.

    PubMed

    Shagina, N B; Tolstykh, E I; Degteva, M O; Anspaugh, L R; Napier, B A

    2015-03-01

    A biokinetic model for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic model for strontium has limitations for use in a population study, because it is not gender specific and does not cover all age ranges. The extensive Techa River data set on (90)Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all ages at intake. These, as well as published data, were used for evaluation of age- and gender-specific parameters for a new compartment biokinetic model for strontium (Sr-AGe model). The Sr-AGe model has a similar structure to the ICRP model for the alkaline earth elements. The following parameters were mainly re-evaluated: gastrointestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-AGe model satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different ages (0-80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-AGe model can be used for dose assessment in epidemiological studies of general populations exposed to ingested strontium radioisotopes.

  13. Age and gender specific biokinetic model for strontium in humans

    SciTech Connect

    Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.

    2015-03-01

    A biokinetic model for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic model for strontium has limitation for use in a population study, because it is not gender specific and does not cover all age ranges. The extensive Techa River data set on 90Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all ages at intake. These, as well as published data, were used for evaluation of age- and gender-specific parameters for a new compartment biokinetic model for strontium (Sr-AGe model). The Sr-AGe model has similar structure as the ICRP model for the alkaline earth elements. The following parameters were mainly reevaluated: gastro-intestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-AGe model satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different ages (0–80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-AGe model can be used for dose assessment in epidemiological studies of general population exposed to ingested strontium radioisotopes.

  14. Genetic Background, Maternal Age, and Interaction Effects Mediate Rates of Crossing Over in Drosophila melanogaster Females.

    PubMed

    Hunter, Chad M; Robinson, Matthew C; Aylor, David L; Singh, Nadia D

    2016-01-01

    Meiotic recombination is a genetic process that is critical for proper chromosome segregation in many organisms. Despite being fundamental for organismal fitness, rates of crossing over vary greatly between taxa. Both genetic and environmental factors contribute to phenotypic variation in crossover frequency, as do genotype-environment interactions. Here, we test the hypothesis that maternal age influences rates of crossing over in a genotypic-specific manner. Using classical genetic techniques, we estimated rates of crossing over for individual Drosophila melanogaster females from five strains over their lifetime from a single mating event. We find that both age and genetic background significantly contribute to observed variation in recombination frequency, as do genotype-age interactions. We further find differences in the effect of age on recombination frequency in the two genomic regions surveyed. Our results highlight the complexity of recombination rate variation and reveal a new role of genotype by maternal age interactions in mediating recombination rate.

  15. Genetic Background, Maternal Age, and Interaction Effects Mediate Rates of Crossing Over in Drosophila melanogaster Females

    PubMed Central

    Hunter, Chad M.; Robinson, Matthew C.; Aylor, David L.; Singh, Nadia D.

    2016-01-01

    Meiotic recombination is a genetic process that is critical for proper chromosome segregation in many organisms. Despite being fundamental for organismal fitness, rates of crossing over vary greatly between taxa. Both genetic and environmental factors contribute to phenotypic variation in crossover frequency, as do genotype–environment interactions. Here, we test the hypothesis that maternal age influences rates of crossing over in a genotypic-specific manner. Using classical genetic techniques, we estimated rates of crossing over for individual Drosophila melanogaster females from five strains over their lifetime from a single mating event. We find that both age and genetic background significantly contribute to observed variation in recombination frequency, as do genotype–age interactions. We further find differences in the effect of age on recombination frequency in the two genomic regions surveyed. Our results highlight the complexity of recombination rate variation and reveal a new role of genotype by maternal age interactions in mediating recombination rate. PMID:26994290

  16. Enhancing adoption of site-specific variable rate sprinkler systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than twenty years of private and public research on site-specific variable-rate sprinkler irrigation (SS-VRI) has resulted in very limited commercial adoption of the technology. Documented and proven water conservation strategies using site-specific irrigation are quite limited, and its cost-ef...

  17. [Sex Specificity in Age-Related Thyroid Hormone Responsiveness].

    PubMed

    Suzuki, Satoru

    2016-01-01

    Similar to other systems, the endocrine system is affected by aging. Thyroid hormone, the action of which is affected by many factors, has been shown to be associated with longevity. The most useful marker for assessment of the thyroid hormone action is the TSH level. Although age and sex are believed to modify the pituitary set point or response to the free thyroid hormone concentration, the precise age- and sex-dependent responses to thyroid hormone have yet to be reported. In this lecture, molecular aspects of resistance to thyroid hormone are initially overviewed. After presentation of the evidence that the TSH-thyroid hormone axis is evolutionarily modified, and that negative feedback mechanisms may start to play roles in homeostatic regulation at the time of delivery, the rationale of age-dependent thyroid hormone resistance is introduced. To assess the age- and sex-dependent resistance to thyroid hormone, the index is provided by the formula based on the relationship between thyroid hormone and TSH levels. The index is calculated by the results of thyroid function tests obtained from the two individual clinical groups. From the results, there were negative relationships between the free T3 resistance index and age in males of both groups, while there were no apparent relationships in females. These findings indicate that there is a male-specific response to thyroid hormone with aging. Furthermore, the specific features of the response may not be affected by environmental factors such as the presence of disorders or medical treatments. PMID:27192800

  18. Uncertainty in age-specific harvest estimates and consequences for white-tailed deer management

    USGS Publications Warehouse

    Collier, B.A.; Krementz, D.G.

    2007-01-01

    Age structure proportions (proportion of harvested individuals within each age class) are commonly used as support for regulatory restrictions and input for deer population models. Such use requires critical evaluation when harvest regulations force hunters to selectively harvest specific age classes, due to impact on the underlying population age structure. We used a stochastic population simulation model to evaluate the impact of using harvest proportions to evaluate changes in population age structure under a selective harvest management program at two scales. Using harvest proportions to parameterize the age-specific harvest segment of the model for the local scale showed that predictions of post-harvest age structure did not vary dependent upon whether selective harvest criteria were in use or not. At the county scale, yearling frequency in the post-harvest population increased, but model predictions indicated that post-harvest population size of 2.5 years old males would decline below levels found before implementation of the antler restriction, reducing the number of individuals recruited into older age classes. Across the range of age-specific harvest rates modeled, our simulation predicted that underestimation of age-specific harvest rates has considerable influence on predictions of post-harvest population age structure. We found that the consequence of uncertainty in harvest rates corresponds to uncertainty in predictions of residual population structure, and this correspondence is proportional to scale. Our simulations also indicate that regardless of use of harvest proportions or harvest rates, at either the local or county scale the modeled SHC had a high probability (>0.60 and >0.75, respectively) of eliminating recruitment into >2.5 years old age classes. Although frequently used to increase population age structure, our modeling indicated that selective harvest criteria can decrease or eliminate the number of white-tailed deer recruited into older

  19. Psychiatric Outcomes at Age Seven for Very Preterm Children: Rates and Predictors

    ERIC Educational Resources Information Center

    Treyvaud, Karli; Ure, Alexandra; Doyle, Lex W.; Lee, Katherine J.; Rogers, Cynthia E.; Kidokoro, Hiroyuki; Inder, Terrie E.; Anderson, Peter J.

    2013-01-01

    Background: Uncertainty remains about the rate of specific psychiatric disorders and associated predictive factors for very preterm (VPT) children. The aims of this study were to document rates of psychiatric disorders in VPT children aged 7 years compared with term born children, and to examine potential predictive factors for psychiatric…

  20. Body growth considerations in age-specific dosimetry. Final report

    SciTech Connect

    Eckerman, K.F.

    1993-09-30

    This report describes the manner in which the age-specific dosimetric calculations of the International Commission on Radiological Protection (ICRP) addressed changes in organ size that occur with age. The approach involves an interpolation of dosimetric information derived for six reference individuals using the inverse of the total body mass as the interpolation variable. An alternative formulation is investigated that employs a functional representation of the organ mass as a function of age in conjunction with an explicit formulation of the dosimetric factors in terms of organ mass. Using an exponential-logistic growth function as suggested by Walker, this report demonstrates, through application to the dosimetry of radioiodines in the thyroid, that the alternative formulation can be formulated and implemented. Although either approach provides a workable basis for age-specific dosimetry, it is clear that the functional representation of organ growth has some attractive features. However, without question, the major difficulty is the quality and quantity of data available to address the age- and gender-specific parameters in the dosimetric formulations.

  1. Age-Specific Preferences for Infant-Directed Affective Intent

    ERIC Educational Resources Information Center

    Kitamura, Christine; Lam, Christa

    2009-01-01

    This study examined the developmental course of infants' attentional preferences for 3 types of infant-directed affective intent, which have been shown to be commonly used at particular ages in the first year of life. Specifically, Kitamura and Burnham (2003) found mothers' tone of voice in infant-directed speech is most comforting between birth…

  2. Estimating cause-specific mortality rates using recovered carcasses.

    PubMed

    Joly, Damien O; Heisey, Dennis M; Samuel, Michael D; Ribic, Christine A; Thomas, Nancy J; Wright, Scott D; Wright, Irene E

    2009-01-01

    Stranding networks, in which carcasses are recovered and sent to diagnostic laboratories for necropsy and determination of cause of death, have been developed to monitor the health of marine mammal and bird populations. These programs typically accumulate comprehensive, long-term datasets on causes of death that can be used to identify important sources of mortality or changes in mortality patterns that lead to management actions. However, the utility of these data in determining cause-specific mortality rates has not been explored. We present a maximum likelihood-based approach that partitions total mortality rate, estimated by independent sources, into cause-specific mortality rates. We also demonstrate how variance estimates are derived for these rates. We present examples of the method using mortality data for California sea otters (Enhydra lutris nereis) and Florida manatees (Trichechus manatus latirostris). PMID:19204341

  3. Radiocarbon Based Ages and Growth Rates: Hawaiian Deep Sea Corals

    SciTech Connect

    Roark, E B; Guilderson, T P; Dunbar, R B; Ingram, B L

    2006-01-13

    The radial growth rates and ages of three different groups of Hawaiian deep-sea 'corals' were determined using radiocarbon measurements. Specimens of Corallium secundum, Gerardia sp., and Leiopathes glaberrima, were collected from 450 {+-} 40 m at the Makapuu deep-sea coral bed using a submersible (PISCES V). Specimens of Antipathes dichotoma were collected at 50 m off Lahaina, Maui. The primary source of carbon to the calcitic C. secundum skeleton is in situ dissolved inorganic carbon (DIC). Using bomb {sup 14}C time markers we calculate radial growth rates of {approx} 170 {micro}m y{sup -1} and ages of 68-75 years on specimens as tall as 28 cm of C. secundum. Gerardia sp., A. dichotoma, and L. glaberrima have proteinaceous skeletons and labile particulate organic carbon (POC) is their primary source of architectural carbon. Using {sup 14}C we calculate a radial growth rate of 15 {micro}m y{sup -1} and an age of 807 {+-} 30 years for a live collected Gerardia sp., showing that these organisms are extremely long lived. Inner and outer {sup 14}C measurements on four sub-fossil Gerardia spp. samples produce similar growth rate estimates (range 14-45 {micro}m y{sup -1}) and ages (range 450-2742 years) as observed for the live collected sample. Similarly, with a growth rate of < 10 {micro}m y{sup -1} and an age of {approx}2377 years, L. glaberrima at the Makapuu coral bed, is also extremely long lived. In contrast, the shallow-collected A. dichotoma samples yield growth rates ranging from 130 to 1,140 {micro}m y{sup -1}. These results show that Hawaiian deep-sea corals grow more slowly and are older than previously thought.

  4. Numerical solution of the Penna model of biological aging with age-modified mutation rate

    NASA Astrophysics Data System (ADS)

    Magdoń-Maksymowicz, M. S.; Maksymowicz, A. Z.

    2009-06-01

    In this paper we present results of numerical calculation of the Penna bit-string model of biological aging, modified for the case of a -dependent mutation rate m(a) , where a is the parent’s age. The mutation rate m(a) is the probability per bit of an extra bad mutation introduced in offspring inherited genome. We assume that m(a) increases with age a . As compared with the reference case of the standard Penna model based on a constant mutation rate m , the dynamics of the population growth shows distinct changes in age distribution of the population. Here we concentrate on mortality q(a) , a fraction of items eliminated from the population when we go from age (a) to (a+1) in simulated transition from time (t) to next time (t+1) . The experimentally observed q(a) dependence essentially follows the Gompertz exponential law for a above the minimum reproduction age. Deviation from the Gompertz law is however observed for the very old items, close to the maximal age. This effect may also result from an increase in mutation rate m with age a discussed in this paper. The numerical calculations are based on analytical solution of the Penna model, presented in a series of papers by Coe [J. B. Coe, Y. Mao, and M. E. Cates, Phys. Rev. Lett. 89, 288103 (2002)]. Results of the numerical calculations are supported by the data obtained from computer simulation based on the solution by Coe

  5. Age and Self-Rated Health in Korea

    ERIC Educational Resources Information Center

    Park, Hyunjoon

    2005-01-01

    I examine age variation in the effects of socioeconomic status (SES) on self-rated health in Korea by including three alternative indicators of SES--liquid assets, home ownership, and real estate ownership--as well as two standard measures of education and household income. Furthermore, I consider the SES-health relationship and its variation by…

  6. Adoption of site-specific variable rate sprinkler irrigation systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than twenty years of private and public research on site-specific variable-rate sprinkler irrigation (SS-VRI) technology has resulted in limited commercial adoption of the technology. Competing patents, liability and proprietary software have affected industry’s willingness to move into a new t...

  7. Slowing of Mortality Rates at Older Ages in Large Medfly Cohorts

    NASA Astrophysics Data System (ADS)

    Carey, James R.; Liedo, Pablo; Orozco, Dina; Vaupel, James W.

    1992-10-01

    It is generally assumed for most species that mortality rates increase monotonically at advanced ages. Mortality rates were found to level off and decrease at older ages in a population of 1.2 million medflies maintained in cages of 7,200 and in a group of approximately 48,000 adults maintained in solitary confinement. Thus, life expectancy in older individuals increased rather than decreased with age. These results cast doubt on several central concepts in gerontology and the biology of aging: (i) that senescence can be characterized by an increase in age-specific mortality, (ii) that the basic pattern of mortality in nearly all species follows the same unitary pattern at older ages, and (iii) that species have absolute life-span limits.

  8. Does the Aging Process Significantly Modify the Mean Heart Rate?

    PubMed Central

    Santos, Marcos Antonio Almeida; Sousa, Antonio Carlos Sobral; Reis, Francisco Prado; Santos, Thayná Ramos; Lima, Sonia Oliveira; Barreto-Filho, José Augusto

    2013-01-01

    Background The Mean Heart Rate (MHR) tends to decrease with age. When adjusted for gender and diseases, the magnitude of this effect is unclear. Objective To analyze the MHR in a stratified sample of active and functionally independent individuals. Methods A total of 1,172 patients aged ≥ 40 years underwent Holter monitoring and were stratified by age group: 1 = 40-49, 2 = 50-59, 3 = 60-69, 4 = 70-79, 5 = ≥ 80 years. The MHR was evaluated according to age and gender, adjusted for Hypertension (SAH), dyslipidemia and non-insulin dependent diabetes mellitus (NIDDM). Several models of ANOVA, correlation and linear regression were employed. A two-tailed p value <0.05 was considered significant (95% CI). Results The MHR tended to decrease with the age range: 1 = 77.20 ± 7.10; 2 = 76.66 ± 7.07; 3 = 74.02 ± 7.46; 4 = 72.93 ± 7.35; 5 = 73.41 ± 7.98 (p < 0.001). Women showed a correlation with higher MHR (p <0.001). In the ANOVA and regression models, age and gender were predictors (p < 0.001). However, R2 and ETA2 < 0.10, as well as discrete standardized beta coefficients indicated reduced effect. Dyslipidemia, hypertension and DM did not influence the findings. Conclusion The MHR decreased with age. Women had higher values of MHR, regardless of the age group. Correlations between MHR and age or gender, albeit significant, showed the effect magnitude had little statistical relevance. The prevalence of SAH, dyslipidemia and diabetes mellitus did not influence the results. PMID:24029962

  9. Does age matter? The influence of age on response rates in a mixed-mode survey

    USGS Publications Warehouse

    Gigliotti, Larry M.; Dietsch, Alia

    2014-01-01

    The appeal of cost savings and faster results has fish and wildlife management agencies considering the use of Internet surveys instead of traditional mail surveys to collect information from their constituents. Internet surveys, however, may suffer from differential age-related response rates, potentially producing biased results if certain age groups respond to Internet surveys differently than they do to mail surveys. We examined this concern using data from a mixed-mode angler survey conducted in South Dakota following the 2011 fishing season. Results indicated that young anglers (16–18) had the lowest return rates and senior anglers (65+) had the highest, regardless of survey mode. Despite this consistency in response rates, we note two concerns: (a) lower Internet response rates and (b) different age groups represented by the Internet and mail survey samples differed dramatically. Findings indicate that constituent groups may be represented differently with the use of various survey modes.

  10. The composite dynamic method as evidence for age-specific waterfowl mortality

    USGS Publications Warehouse

    Burnham, Kenneth P.; Anderson, David R.

    1979-01-01

    For the past 25 years estimation of mortality rates for waterfowl has been based almost entirely on the composite dynamic life table. We examined the specific assumptions for this method and derived a valid goodness of fit test. We performed this test on 45 data sets representing a cross section of banded sampled for various waterfowl species, geographic areas, banding periods, and age/sex classes. We found that: (1) the composite dynamic method was rejected (P <0.001) in 37 of the 45 data sets (in fact, 29 were rejected at P <0.00001) and (2) recovery and harvest rates are year-specific (a critical violation of the necessary assumptions). We conclude that the restrictive assumptions required for the composite dynamic method to produce valid estimates of mortality rates are not met in waterfowl data. Also we demonstrate that even when the required assumptions are met, the method produces very biased estimates of age-specific mortality rates. We believe the composite dynamic method should not be used in the analysis of waterfowl banding data. Furthermore, the composite dynamic method does not provide valid evidence for age-specific mortality rates in waterfowl.

  11. The surface age of Venus: Applying the terrestrial cratering rate

    NASA Technical Reports Server (NTRS)

    Schaber, Gerald G.; Shoemaker, Eugene M.; Kozak, Richard C.

    1987-01-01

    The population of Venusian craters having suspected impact crater morphology has been reported from 115 x 10 to the 6th power sq km of the northern hemisphere of the planet with the estimated average age of the surface to be approx. 1 b.y. (+ or - 0.5 b.y.) on the basis of lunar crater production curves corrected for Venus. Such an old average age is somewhat difficult to reconcile with the similarity in size and mass of Venus and Earth and with Earth's high heat flow and crustal resurfacing rate. Given the present uncertainties in the role of both active and inactive comet nuclei in the cratering history of Earth, it is concluded that the average age of the observed surface in the northern hemisphere of Venus could be as great as the 450 m.y. mean age of the Earth's crust. The surface of Venus might be even older, but no evidence from the crater observations support an age as great as 1 b.y.

  12. Is basal metabolic rate influenced by age in a long-lived seabird, the snow petrel?

    PubMed

    Moe, Børge; Angelier, Frédéric; Bech, Claus; Chastel, Olivier

    2007-10-01

    Ageing is associated with a decline in basal metabolic rate (BMR) in many species, including humans. The evolutionary and physiological causes underlying the relationship between age and BMR are poorly understood. Studies of procellariiform seabirds may provide valuable insight because they have a longer maximum lifespan than expected from their body size and rates of energy metabolism. Such studies are rare, however, because there are few populations with a high proportion of individuals of known age. We performed a cross-sectional study of energy metabolism in relation to age in a long-lived seabird, the snow petrel Pagodroma nivea. In an Antarctic population that has been subject to a long-term research program, including annual banding of chicks since 1963, we measured BMR of individuals aged between 8 and 39 years. We show that the BMR of the snow petrel does not decrease with increasing age. BMR seems to be sustained at a fixed level throughout the investigated age-span. We review this result in light of the disposable soma theory of ageing, and we discuss whether species-specific relationships between age and basal metabolic rate can be related to differences in maximum lifespan. PMID:17872994

  13. Why Do Older Men Report Low Stress Ratings? Findings from the Veterans Affairs Normative Aging Study

    ERIC Educational Resources Information Center

    Boeninger, Daria K.; Shiraishi, Ray W.; Aldwin, Carolyn M.; Spiro, Avron, III

    2009-01-01

    We examined the interplay between three explanatory hypotheses for why older adults appear to rate their problems as less stressful than do younger adults: age-related differences in personality, in types of problems, and in the appraisal process--specifically, the number of primary stress appraisals. A sample of 1,054 men from the Normative Aging…

  14. Country- and age-specific optimal allocation of dengue vaccines.

    PubMed

    Ndeffo Mbah, Martial L; Durham, David P; Medlock, Jan; Galvani, Alison P

    2014-02-01

    Several dengue vaccines are under development, and some are expected to become available imminently. Concomitant with the anticipated release of these vaccines, vaccine allocation strategies for dengue-endemic countries in Southeast Asia and Latin America are currently under development. We developed a model of dengue transmission that incorporates the age-specific distributions of dengue burden corresponding to those in Thailand and Brazil, respectively, to determine vaccine allocations that minimize the incidence of dengue hemorrhagic fever, taking into account limited availability of vaccine doses in the initial phase of production. We showed that optimal vaccine allocation strategies vary significantly with the demographic burden of dengue hemorrhagic fever. Consequently, the strategy that is optimal for one country may be sub-optimal for another country. More specifically, we showed that, during the first years following introduction of a dengue vaccine, it is optimal to target children for dengue mass vaccination in Thailand, whereas young adults should be targeted in Brazil.

  15. Preliminary Transportation, Aging and Disposal Canister System Performance Specification

    SciTech Connect

    C.A Kouts

    2006-11-22

    This document provides specifications for selected system components of the Transportation, Aging and Disposal (TAD) canister-based system. A list of system specified components and ancillary components are included in Section 1.2. The TAD canister, in conjunction with specialized overpacks will accomplish a number of functions in the management and disposal of spent nuclear fuel. Some of these functions will be accomplished at purchaser sites where commercial spent nuclear fuel (CSNF) is stored, and some will be performed within the Office of Civilian Radioactive Waste Management (OCRWM) transportation and disposal system. This document contains only those requirements unique to applications within Department of Energy's (DOE's) system. DOE recognizes that TAD canisters may have to perform similar functions at purchaser sites. Requirements to meet reactor functions, such as on-site dry storage, handling, and loading for transportation, are expected to be similar to commercially available canister-based systems. This document is intended to be referenced in the license application for the Monitored Geologic Repository (MGR). As such, the requirements cited herein are needed for TAD system use in OCRWM's disposal system. This document contains specifications for the TAD canister, transportation overpack and aging overpack. The remaining components and equipment that are unique to the OCRWM system or for similar purchaser applications will be supplied by others.

  16. Bunch mode specific rate corrections for PILATUS3 detectors

    DOE PAGES

    Trueb, P.; Dejoie, C.; Kobas, M.; Pattison, P.; Peake, D. J.; Radicci, V.; Sobott, B. A.; Walko, D. A.; Broennimann, C.

    2015-04-09

    PILATUS X-ray detectors are in operation at many synchrotron beamlines around the world. This article reports on the characterization of the new PILATUS3 detector generation at high count rates. As for all counting detectors, the measured intensities have to be corrected for the dead-time of the counting mechanism at high photon fluxes. The large number of different bunch modes at these synchrotrons as well as the wide range of detector settings presents a challenge for providing accurate corrections. To avoid the intricate measurement of the count rate behaviour for every bunch mode, a Monte Carlo simulation of the counting mechanismmore » has been implemented, which is able to predict the corrections for arbitrary bunch modes and a wide range of detector settings. This article compares the simulated results with experimental data acquired at different synchrotrons. It is found that the usage of bunch mode specific corrections based on this simulation improves the accuracy of the measured intensities by up to 40% for high photon rates and highly structured bunch modes. For less structured bunch modes, the instant retrigger technology of PILATUS3 detectors substantially reduces the dependency of the rate correction on the bunch mode. The acquired data also demonstrate that the instant retrigger technology allows for data acquisition up to 15 million photons per second per pixel.« less

  17. Bunch mode specific rate corrections for PILATUS3 detectors

    PubMed Central

    Trueb, P.; Dejoie, C.; Kobas, M.; Pattison, P.; Peake, D. J.; Radicci, V.; Sobott, B. A.; Walko, D. A.; Broennimann, C.

    2015-01-01

    PILATUS X-ray detectors are in operation at many synchrotron beamlines around the world. This article reports on the characterization of the new PILATUS3 detector generation at high count rates. As for all counting detectors, the measured intensities have to be corrected for the dead-time of the counting mechanism at high photon fluxes. The large number of different bunch modes at these synchrotrons as well as the wide range of detector settings presents a challenge for providing accurate corrections. To avoid the intricate measurement of the count rate behaviour for every bunch mode, a Monte Carlo simulation of the counting mechanism has been implemented, which is able to predict the corrections for arbitrary bunch modes and a wide range of detector settings. This article compares the simulated results with experimental data acquired at different synchrotrons. It is found that the usage of bunch mode specific corrections based on this simulation improves the accuracy of the measured intensities by up to 40% for high photon rates and highly structured bunch modes. For less structured bunch modes, the instant retrigger technology of PILATUS3 detectors substantially reduces the dependency of the rate correction on the bunch mode. The acquired data also demonstrate that the instant retrigger technology allows for data acquisition up to 15 million photons per second per pixel. PMID:25931086

  18. Bunch mode specific rate corrections for PILATUS3 detectors

    SciTech Connect

    Trueb, P.; Dejoie, C.; Kobas, M.; Pattison, P.; Peake, D. J.; Radicci, V.; Sobott, B. A.; Walko, D. A.; Broennimann, C.

    2015-04-09

    PILATUS X-ray detectors are in operation at many synchrotron beamlines around the world. This article reports on the characterization of the new PILATUS3 detector generation at high count rates. As for all counting detectors, the measured intensities have to be corrected for the dead-time of the counting mechanism at high photon fluxes. The large number of different bunch modes at these synchrotrons as well as the wide range of detector settings presents a challenge for providing accurate corrections. To avoid the intricate measurement of the count rate behaviour for every bunch mode, a Monte Carlo simulation of the counting mechanism has been implemented, which is able to predict the corrections for arbitrary bunch modes and a wide range of detector settings. This article compares the simulated results with experimental data acquired at different synchrotrons. It is found that the usage of bunch mode specific corrections based on this simulation improves the accuracy of the measured intensities by up to 40% for high photon rates and highly structured bunch modes. For less structured bunch modes, the instant retrigger technology of PILATUS3 detectors substantially reduces the dependency of the rate correction on the bunch mode. The acquired data also demonstrate that the instant retrigger technology allows for data acquisition up to 15 million photons per second per pixel.

  19. Parasite Rates of Discovery, Global Species Richness and Host Specificity.

    PubMed

    Costello, Mark John

    2016-10-01

    If every metazoan species has at least one host-specific parasite, as several local scale studies have suggested, then half of all species could be parasites. However, host specificity varies significantly depending on host phylogeny, body size, habitat, and geographic distribution. The best studied hosts tend to be vertebrates, larger animals, and/or widespread, and thus have a higher number of parasites and host-specific parasites. Thus, host specificity for these well-known taxa cannot be simply extrapolated to other taxa, notably invertebrates, small sized, and more endemic species, which comprise the major portion of yet to be discovered species. At present, parasites of animals comprise about 5% of named species. This article analyzed the rate of description of several largely parasitic taxa within crustaceans (copepods, amphipods, isopods, pentastomids, cirripeds), marine helminths (nematodes, acanthocephalans, flukes), gastropod molluscs, insects (ticks, fleas, biting flies, strepispterans), and microsporidia. The period of highest discovery has been most recent for the marine helminths and microsporids. The number of people describing parasites has been increasing since the 1960s, as it has for all other taxa. However, the number of species being described per decade relative to the number of authors has been decreasing except for the helminths. The results indicate that more than half of all parasites have been described, and two-thirds of host taxa, although the proportion varies between taxa. It is highly unlikely that the number of named species of parasites will ever approach that of their hosts. This contrast between the proportion that parasites comprise of local and global faunas suggests that parasites are less host specific and more widespread than local scale studies suggest.

  20. Site- and species-specific hydrolysis rates of heroin.

    PubMed

    Szöcs, Levente; Orgován, Gábor; Tóth, Gergő; Kraszni, Márta; Gergó, Lajos; Hosztafi, Sándor; Noszál, Béla

    2016-06-30

    The hydroxide-catalyzed non-enzymatic, simultaneous and consecutive hydrolyses of diacetylmorphine (DAM, heroin) are quantified in terms of 10 site- and species-specific rate constants in connection with also 10 site- and species-specific acid-base equilibrium constants, comprising all the 12 coexisting species in solution. This characterization involves the major and minor decomposition pathways via 6-acetylmorphine and 3-acetylmorphine, respectively, and morphine, the final product. Hydrolysis has been found to be 18-120 times faster at site 3 than at site 6, depending on the status of the amino group and the rest of the molecule. Nitrogen protonation accelerates the hydrolysis 5-6 times at site 3 and slightly less at site 6. Hydrolysis rate constants are interpreted in terms of intramolecular inductive effects and the concomitant local electron densities. Hydrolysis fraction, a new physico-chemical parameter is introduced and determined to quantify the contribution of the individual microspecies to the overall hydrolysis. Hydrolysis fractions are depicted as a function of pH. PMID:27130543

  1. Determination of specific growth rate by measurement of specific rate of ribosome synthesis in growing and nongrowing cultures of Acinetobacter calcoaceticus.

    PubMed

    Cutter, Matthew R; Stroot, Peter G

    2008-02-01

    RT-RiboSyn measures the specific rate of ribosome synthesis in distinct microbial populations by measuring the generation rate of precursor 16S rRNA relative to that of mature 16S rRNA when precursor 16S rRNA processing is inhibited. Good agreement was demonstrated between specific rate of ribosome synthesis and specific growth rate of Acinetobacter calcoaceticus.

  2. Effects of simulated increased gravity on the rate of aging of rats - Implications for the rate of living theory of aging

    NASA Technical Reports Server (NTRS)

    Economos, A. C.; Ballard, R. C.; Blunden, M.; Miquel, J.; Lindseth, K. A.; Fleming, J.; Philpott, D. E.; Oyama, J.

    1982-01-01

    It was found that the rate of aging of 17 month old rats which had been exposed to 3.14 times normal gravity in an animal centrifuge for 8 months was larger than that of the controls as determined by the apparently elevated lipofuscin content in heart and kidney, reduced numbers and increased size of mitochondria of heart tissue, and inferior liver mitochondria respiration. Steady-state food intake per day per kg body weight, which is presumably proportional to rate of living or specific basal metabolic expenditure, was found to be about 18 percent higher than in the controls after an initial 2 month adaptation period. Although half of the centrifuged animals lived only a little shorter than the controls (average about 343 vs. 364 days on the average, statistically nonsignificant), the remaining half (longest survivors) lived on the centrifuge an average of 520 days (range 483-572) compared to an average of 574 days (range 502-615) for the controls, computed from the onset of centrifugation, or 11 percent shorter. These findings indicate that a moderate increase of the level of basal metabolism of young adult rats adapted to hypergravity compared to controls in normal gravity is accompanied by a roughly similar increase in the rate of organ aging and reduction of survival, in agreement with Pearl's (1928) rate of living theory of aging, previously experimentally demonstrated only in poikilotherms.

  3. Basis for the ICRP`s age-specific biokinetic model for uranium

    SciTech Connect

    Leggett, R.W.

    1994-12-01

    In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is developing age-specific biokinetic models and dose coefficients for environmentally important radionuclides. This paper describes the ICRP`s age-specific biokinetic model for uranium. The model is constructed within a physiologically based framework originally developed for application to the alkaline earth elements but sufficiently general to apply to the larger class of bone-volume-seeking elements. Transfer rates for a reference adult are based mainly on: (1) measurements of uranium in blood and excreta of several human subjects who were intravenously injected with uranium; (2) postmortem measurements of uranium in tissues of some of those subjects; (3) postmortem measurements of uranium in tissues of occupationally and non-occupationally exposed subjects; (4) data on baboons, dogs, and smaller laboratory animals exposed to uranium for experimental purposes; and (5) consideration of the physiological processes thought to control retention and translocation of uranium in the body. Transfer rates for the adult are extended to children by application of a set of generic assumptions applied by the ICRP to calcium-like elements. These assumptions were derived mainly from observations of the age-specific biokinetics of the alkaline earth elements and lead in humans and laboratory animals but are consistent with available age-specific biokinetic data on uranium. 82 refs., 17 figs., 8 tabs.

  4. Age, growth rates, and paleoclimate studies of deep sea corals

    USGS Publications Warehouse

    Prouty, Nancy G; Roark, E. Brendan; Andrews, Allen; Robinson, Laura; Hill, Tessa; Sherwood, Owen; Williams, Branwen; Guilderson, Thomas P.; Fallon, Stewart

    2015-01-01

    Deep-water corals are some of the slowest growing, longest-lived skeletal accreting marine organisms. These habitat-forming species support diverse faunal assemblages that include commercially and ecologically important organisms. Therefore, effective management and conservation strategies for deep-sea corals can be informed by precise and accurate age, growth rate, and lifespan characteristics for proper assessment of vulnerability and recovery from perturbations. This is especially true for the small number of commercially valuable, and potentially endangered, species that are part of the black and precious coral fisheries (Tsounis et al. 2010). In addition to evaluating time scales of recovery from disturbance or exploitation, accurate age and growth estimates are essential for understanding the life history and ecology of these habitat-forming corals. Given that longevity is a key factor for population maintenance and fishery sustainability, partly due to limited and complex genetic flow among coral populations separated by great distances, accurate age structure for these deep-sea coral communities is essential for proper, long-term resource management.

  5. Trait compensation and sex-specific aging of performance in male and female professional basketball players.

    PubMed

    Lailvaux, Simon P; Wilson, Robbie; Kasumovic, Michael M

    2014-05-01

    Phenotypic traits are often influenced by dynamic resource allocation trade-offs which, when occurring over the course of individual lifespan, may manifest as trait aging. Although aging is studied for a variety of traits that are closely tied to reproduction or reproductive effort, the aging of multiple traits related to fitness in other ways are less well understood. We took advantage of almost 30 years of data on human whole-organism performance in the National Basketball Association (USA) to examine trends of aging in performance traits associated with scoring. Given that patterns of aging differ between sexes in other animal species, we also analyzed a smaller dataset on players in the Women's National Basketball Association to test for potential sex differences in the aging of comparable traits. We tested the hypothesis that age-related changes in a specific aspect of overall performance can be compensated for by elevated expression of another, related aspect. Our analyses suggest that the aging of performance traits used in basketball is generally characterized by senescence in males, whereas age-related changes in basketball performance are less evident in females. Our data also indicate a different rate of senescence of different performance traits associated with scoring over a male's lifetime.

  6. Age of acquisition predicts rate of lexical evolution.

    PubMed

    Monaghan, Padraic

    2014-12-01

    The processes taking place during language acquisition are proposed to influence language evolution. However, evidence demonstrating the link between language learning and language evolution is, at best, indirect, constituting studies of laboratory-based artificial language learning studies or computational simulations of diachronic change. In the current study, a direct link between acquisition and evolution is established, showing that for two hundred fundamental vocabulary items, the age at which words are acquired is a predictor of the rate at which they have changed in studies of language evolution. Early-acquired words are more salient and easier to process than late-acquired words, and these early-acquired words are also more stably represented within the community's language. Analysing the properties of these early-acquired words potentially provides insight into the origins of communication, highlighting features of words that have been ultra-conserved in language.

  7. Modelling the strategies for age specific vaccination scheduling during influenza pandemic outbreaks.

    PubMed

    Knipl, Diána H; Röst, Gergely

    2011-01-01

    Finding optimal policies to reduce the morbidity and mortality of the ongoing pandemic is a top public health priority. Using a compartmental model with age structure and vaccination status, we examined the effect of age specific scheduling of vaccination during a pandemic influenza outbreak, when there is a race between the vaccination campaign and the dynamics of the pandemic. Our results agree with some recent studies on that age specificity is paramount to vaccination planning. However, little is known about the effectiveness of such control measures when they are applied during the outbreak. Comparing five possible strategies, we found that age specific scheduling can have a huge impact on the outcome of the epidemic. For the best scheme, the attack rates were up to 10% lower than for other strategies. We demonstrate the importance of early start of the vaccination campaign, since ten days delay may increase the attack rate by up to 6%. Taking into account the delay between developing immunity and vaccination is a key factor in evaluating the impact of vaccination campaigns. We provide a general framework which will be useful for the next pandemic waves as well. PMID:21361404

  8. Commodity specific rates of temporal discounting: does metabolic function underlie differences in rates of discounting?

    PubMed

    Charlton, Shawn R; Fantino, Edmund

    2008-03-01

    Discounting rates vary as a function of commodity type. Previous studies suggest five potential characteristics of the commodity that could explain these differences: type of reinforcer (primary or secondary), if the commodity is perishable, if the commodity is satiable, if the commodity can be directly consumed, and immediacy of consumption. This paper suggests that these characteristics may best be viewed as related to a more fundamental characteristic: metabolic processing. In order to explore the possibility that metabolic processing underlies changes in discount rates, the difference in discounting between food, money, music CDs, DVDs, and books are compared. Music CDs, DVDs, and books share many characteristics in common with food, including gaining value through a physiological process, but are not directly metabolized. Results are consistent with previous findings of commodity specific discount rates and show that metabolic function plays a role in determining discount rates with those commodities that are metabolized being discounted at a higher rate. These results are interpreted as evidence that the discount rate for different commodities lies along a continuum with those that serve an exchange function rather than a direct function (money) anchoring the low end and those that serve a direct metabolic function capping the high end (food, alcohol, drugs). PMID:17919848

  9. Effects of Applied Strain on Rates of Ageing: Project Overview

    NASA Technical Reports Server (NTRS)

    Campion, R. P.

    1997-01-01

    One of the stated intents of this project has been to make some assessment of effects of strain on rates of ageing of project thermoplastics exposed to project fluids. To this end, certain straining jigs which apply in various modes - tensile, four-point bending and crack growth using compact tension samples - were designed and made for holding samples during fluid exposures. During testing, features of the thermoplastics have been observed which have tended to confuse apparent strain effects on the polymers' aged performance, but recent assessments of the topic and its data have led to considerable progress being made in identifying test procedures necessary for strain and related effects on chemical deterioration to manifest themselves. It is the intent of this report to provide a summary of what has been determined on strain and related effects thus far, and provide recommendations for clarifying them in Phase 2 by means of further test procedures which will increase and focus the severity of the conditions applying. The choice of flexible pipe rather than umbilicals service for assessing service strain conditions reflects the major interest of project members. However, Tefzel data are still provided.

  10. Age and weathering rate of sediments in small catchments: the role of hillslope erosion

    NASA Astrophysics Data System (ADS)

    Dosseto, A.; Buss, H. L.; Chabaux, F.

    2014-12-01

    Erosion is intimately linked to chemical weathering, however we lack quantitative constraints on how erosion processes impact mineral weathering rates. Here we use the uranium-series isotope composition of river-borne material in small catchments of Puerto Rico and southeastern Australia to study the effect of contrasting erosion regimes on weathering. The U-series isotope composition of stream sediments was modelled to infer a weathering age, i.e. the average time elapsed since the sediment's minerals have started weathering. In southeastern Australia, the weathering age of stream sediments ranges between 346 ± 12 kyr and 1.78 ± 0.16 Myr, similar to values inferred from weathering profiles in the same catchment. Old weathering ages likely reflect the shallow origin of sediments mobilised via near-surface soil transport, the main mechanism of erosion in this catchment. Contrastingly, in Puerto Rico weathering ages are much younger, ranging from 5.1 ± 0.1 to 19.4 ± 0.4 kyr, reflecting that sediments are derived from less weathered, deeper saprolite, mobilised by landslides. Weathering ages of stream sediments are used to infer catchment-wide, mineral-specific weathering rates that are one to two orders of magnitude faster for Puerto Rico than for southeastern Australia. Thus, the type of erosion (near-surface soil transport vs. landslide) also affects the weathering rate of river sediments, because their weathering ages determine the potential for further weathering during sediment transport and storage in alluvial plains.

  11. Tissue-specific implications of mitochondrial alterations in aging

    PubMed Central

    Liu, Danhui; Li, Hongzhi; Lu, Jianxin; Bai, Yidong

    2016-01-01

    Aging is a multifactorial process during which physiological alterations occur in all tissues. A decline in mitochondrial function plays an important role in the process of aging and in aging-associated diseases. The mitochondrial genome encodes 13 essential subunits of protein complexes belonging to the oxidative phosphorylation system, while most of the mitochondria-related genes are encoded by the nuclear genome. Coordination between the nucleus and mitochondria is crucial for the regulation of mitochondrial biogenesis and function. In this review, we will discuss aging-related mitochondrial dysfunction in various tissues and its implication in aging-related diseases and the aging process. PMID:23277028

  12. Is the rate of metabolic ageing and survival determined by Basal metabolic rate in the zebra finch?

    PubMed

    Rønning, Bernt; Moe, Børge; Berntsen, Henrik H; Noreen, Elin; Bech, Claus

    2014-01-01

    The relationship between energy metabolism and ageing is of great interest because aerobic metabolism is the primary source of reactive oxygen species which is believed to be of major importance in the ageing process. We conducted a longitudinal study on captive zebra finches where we tested the effect of age on basal metabolic rate (BMR), as well as the effect of BMR on the rate of metabolic ageing (decline in BMR with age) and survival. Basal metabolic rate declined with age in both sexes after controlling for the effect of body mass, indicating a loss of functionality with age. This loss of functionality could be due to accumulated oxidative damage, believed to increase with increasing metabolic rate, c.f. the free radical theory of ageing. If so, we would expect the rate of metabolic ageing to increase and survival to decrease with increasing BMR. However, we found no effect of BMR on the rate of metabolic ageing. Furthermore, survival was not affected by BMR in the males. In female zebra finches there was a tendency for survival to decrease with increasing BMR, but the effect did not reach significance (P<0.1). Thus, the effect of BMR on the rate of functional deterioration with age, if any, was not strong enough to influence neither the rate of metabolic ageing nor survival in the zebra finches.

  13. Age and Sex Differences in Rates of Influenza-Associated Hospitalizations in Hong Kong.

    PubMed

    Wang, Xi-Ling; Yang, Lin; Chan, Kwok-Hung; Chan, King-Pan; Cao, Pei-Hua; Lau, Eric Ho-Yin; Peiris, J S Malik; Wong, Chit-Ming

    2015-08-15

    Few studies have explored age and sex differences in the disease burden of influenza, although men and women probably differ in their susceptibility to influenza infections. In this study, quasi-Poisson regression models were applied to weekly age- and sex-specific hospitalization numbers of pneumonia and influenza cases in the Hong Kong SAR, People's Republic of China, from 2004 to 2010. Age and sex differences were assessed by age- and sex-specific rates of excess hospitalization for influenza A subtypes A(H1N1), A(H3N2), and A(H1N1)pdm09 and influenza B, respectively. We found that, in children younger than 18 years, boys had a higher excess hospitalization rate than girls, with the male-to-female ratio of excess rate (MFR) ranging from 1.1 to 2.4. MFRs of hospitalization associated with different types/subtypes were less than 1.0 for adults younger than 40 years except for A(H3N2) (MFR = 1.6), while all the MFRs were equal to or higher than 1.0 in adults aged 40 years or more except for A(H1N1)pdm09 in elderly persons aged 65 years or more (MFR = 0.9). No MFR was found to be statistically significant (P < 0.05) for hospitalizations associated with influenza type/subtype. There is some limited evidence on age and sex differences in hospitalization associated with influenza in the subtropical city of Hong Kong.

  14. Site-specific hydrogen diffusion rates during clinopyroxene dehydration

    NASA Astrophysics Data System (ADS)

    Ferriss, Elizabeth; Plank, Terry; Walker, David

    2016-06-01

    The rate of hydrogen diffusion in clinopyroxene is relevant to interpreting hydrogen ("water") concentrations in xenoliths, phenocrysts, and clinopyroxene-hosted melt inclusions to provide insight into the deep-earth water cycle and volcanic explosivity. Here, we determine bulk and site-specific hydrogen diffusivities in two diopsides and an augite by heating initially homogeneous water-bearing samples in a 1-atm CO/CO2 gas-mixing furnace at 800-1000 °C and oxygen fugacity at the quartz-fayalite-magnetite buffer and observing H-loss profiles. The O-H stretching range between wavenumbers 3000 and 4000 cm-1 in FTIR spectra is resolved into 4-6 peaks, each of which is assumed to represent a distinct defect site for the hydrogen, to determine peak-specific diffusivities using our previously published whole-block method. For the diopside from the Kunlun Mts. in China, Arrhenius relations are reported for peaks at 3645, 3617, 3540, 3443, and 3355 cm-1 based on measurements at 816, 904, and 1000 °C. Bulk and site-specific diffusivities are determined for the same set of peaks at 904 °C for the second diopside (Jaipur). The augite (PMR-53) was a triangular thin slab, and hydrogen diffusivities were determined for bulk hydrogen and peaks at 3620, 3550, 3460, and 3355 cm-1 in the thickness direction at 800 °C. Bulk hydrogen diffusivity in the Jaipur diopside is consistent with previous work, and hydrogen diffusivity in augite PMR-53 is slightly lower than the fast direction diffusivities measured || [100] and [001]* in Jaipur diopside. Both diopsides show 1-2 orders of magnitude differences in the peaks-specific diffusivities, with the fastest diffusivities at 3450 cm-1 and the slowest at 3645 cm-1. However, the hydrogen diffusivities in Jaipur diopside are 2-4 orders of magnitude higher than those in Kunlun diopside for bulk hydrogen and all peaks. Thus, peak-specific differences cannot by themselves adequately explain the 5 orders of magnitude range in hydrogen

  15. Age-specific survival estimates of King Eiders derived from satellite telemetry

    USGS Publications Warehouse

    Oppel, Steffen; Powell, Abby N.

    2010-01-01

    Age- and sex-specific survival and dispersal are important components in the dynamics and genetic structure of bird populations. For many avian taxa survival rates at the adult and juvenile life stages differ, but in long-lived species juveniles' survival is logistically challenging to study. We present the first estimates of hatch-year annual survival rates for a sea duck, the King Eider (Somateria spectabilis), estimated from satellite telemetry. From 2006 to 2008 we equipped pre-fiedging King Eiders with satellite transmitters on breeding grounds in Alaska and estimated annual survival rates during their first 2 years of life with known-fate models. We compared those estimates to survival rates of adults marked in the same area from 2002 to 2008. Hatch-year survival varied by season during the first year of life, and model-averaged annual survival rate was 0.67 (95% CI: 0.48–0.80). We did not record any mortality during the second year and were therefore unable to estimate second-year survival rate. Adults' survival rate was constant through the year (0.94, 95% CI: 0.86–0.97). No birds appeared to breed during their second summer. While 88% of females with an active transmitter (n = 9) returned to their natal area at the age of 2 years, none of the 2-year old males (n = 3) did. This pattern indicates that females' natal philopatry is high and suggests that males' higher rates of dispersal may account for sex-specific differences in apparent survival rates of juvenile sea ducks when estimated with mark—recapture methods.

  16. Age-standardized incidence rates of primordial cyst (keratocyst) on the Witwatersrand.

    PubMed

    Rachanis, C C; Shear, M

    1978-11-01

    Cases of primordial cysts derived from the records of all the hospital pathology departments and private pathology practices on the Witwatersrand, were recorded for the 10-year period 1965-74. The population at risk (1970 census) was 974,390 Whites and 1,567,280 Blacks. Age-specific morbidity rates for each sex and race were calculated, as well as age-standardized incidence rates standardized against African, World and European standard populations. The age-standardized incidence rates for primordial cysts, standardized against a World standard population, per million per year are 0.61, 0, 4.86 and 3.50 for Black males and females and White males and females, respectively. In the population at risk, primordial cysts are much more common in Whites than in Blacks, the incidence being eight times higher in White males than in Black males. The present study confirms that there is a bimodal age distribution but with a higher incidence of the cyst in the age group 50-64 years than previously suspected. This may be either because a substantial number of cases remain undiagnosed for many years or because there are two groups of primordial cyst: one which is triggered in young patients and the other in older patients.

  17. On the cosmic evolution of the specific star formation rate

    NASA Astrophysics Data System (ADS)

    Lehnert, M. D.; van Driel, W.; Le Tiran, L.; Di Matteo, P.; Haywood, M.

    2015-05-01

    The apparent correlation between the specific star formation rate (sSFR) and total stellar mass (M⋆) of galaxies is a fundamental relationship indicating how they formed their stellar populations. To attempt to understand this relation, we hypothesize that the relation and its evolution is regulated by the increase in the stellar and gas mass surface density in galaxies with redshift, which is itself governed by the angular momentum of the accreted gas, the amount of available gas, and by self-regulation of star formation. With our model, we can reproduce the specific SFR - M⋆ relations at z ~ 1-2 by assuming gas fractions and gas mass surface densities similar to those observed for z = 1-2 galaxies. We further argue that it is the increasing angular momentum with cosmic time that causes a decrease in the surface density of accreted gas. The gas mass surface densities in galaxies are controlled by the centrifugal support (i.e., angular momentum), and the sSFR is predicted to increase as, sSFR(z) = (1 + z)3/tH0, as observed (where tH0 is the Hubble time and no free parameters are necessary). In addition, the simple evolution for the star-formation intensity we propose is in agreement with observations of Milky Way-like galaxies selected through abundance matching. At z ≳ 2, we argue that star formation is self-regulated by high pressures generated by the intense star formation itself. The star formation intensity must be high enough to either balance the hydrostatic pressure (a rather extreme assumption) or to generate high turbulent pressure in the molecular medium which maintains galaxies near the line of instability (i.e. Toomre Q ~ 1). We provide simple prescriptions for understanding these self-regulation mechanisms based on solid relationships verified through extensive study. In all cases, the most important factor is the increase in stellar and gas mass surface density with redshift, which allows distant galaxies to maintain high levels of s

  18. Trends in age-specific cerebrovascular disease in the European Union

    PubMed Central

    Wang, Hui; Sun, Wei; Ji, Yue; Shi, Jing; Xuan, Qinkao; Wang, Xiuzhi; Xiao, Junjie; Kong, Xiangqing

    2014-01-01

    Although the mortality of cerebrovascular disease (CVD) has been steadily declined in the European Union (EU), CVD remains among the major causes of death in EU. As risk factors such asobesity and diabetes mellitus are increasing, the trends of European CVD mortality remains unknown. To understand the variation in CVD mortality of different EU countries, we studied the trends in CVD mortality in EU countries over the last three decades between males and females. Age- and sex-specific mortality rates between 1980 and 2011 were calculated by data from the WHO mortality database. Joinpoint software was used to calculate annual percentage changes and to characterize trends in mortality rates over time. Our study showed that between 1980 and 2011, CVD mortality significantly decreased in both men and women across all age groups. The specific mortality trends varied largely between EU countries. The plateau trend was observed in little regions at different age groups, however, the EU as a whole displayed declined trend CVD mortality. During the last three decades, CVD mortality decreased substantially in the entire population of EU. However, despite this overall decline in CVD mortality, several areas were identified as having no change in their CVD mortality rates at different period. The whole EU needs to establish strict prevention measures toreduce the incidence of CVD risk factors. PMID:25550927

  19. Decreased specific star formation rates in AGN host galaxies

    NASA Astrophysics Data System (ADS)

    Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio; Koss, Michael; Rosario, David J.

    2015-09-01

    We investigate the location of an ultra-hard X-ray selected sample of active galactic nuclei (AGN) from the Swift Burst Alert Telescope (BAT) catalogue with respect to the main sequence (MS) of star-forming galaxies using Herschel-based measurements of the star formation rate (SFR) and M*'s from Sloan Digital Sky Survey photometry where the AGN contribution has been carefully removed. We construct the MS with galaxies from the Herschel Reference Survey and Herschel Stripe 82 Survey using the exact same methods to measure the SFR and M* as the Swift/BAT AGN. We find that a large fraction of the Swift/BAT AGN lie below the MS indicating decreased specific SFR (sSFR) compared to non-AGN galaxies. The Swift/BAT AGN are then compared to a high-mass galaxy sample (CO Legacy Database for GALEX Arecibo SDSS Survey, COLD GASS), where we find a similarity between the AGN in COLD GASS and the Swift/BAT AGN. Both samples of AGN lie firmly between star-forming galaxies on the MS and quiescent galaxies far below the MS. However, we find no relationship between the X-ray luminosity and distance from the MS. While the morphological distribution of the BAT AGN is more similar to star-forming galaxies, the sSFR of each morphology is more similar to the COLD GASS AGN. The merger fraction in the BAT AGN is much higher than the COLD GASS AGN and star-forming galaxies and is related to distance from the MS. These results support a model in which bright AGN tend to be in high-mass star-forming galaxies in the process of quenching which eventually starves the supermassive black hole itself.

  20. Structural modeling of age specific fertility curves in Peninsular Malaysia: An approach of Lee Carter method

    NASA Astrophysics Data System (ADS)

    Hanafiah, Hazlenah; Jemain, Abdul Aziz

    2013-11-01

    In recent years, the study of fertility has been getting a lot of attention among research abroad following fear of deterioration of fertility led by the rapid economy development. Hence, this study examines the feasibility of developing fertility forecasts based on age structure. Lee Carter model (1992) is applied in this study as it is an established and widely used model in analysing demographic aspects. A singular value decomposition approach is incorporated with an ARIMA model to estimate age specific fertility rates in Peninsular Malaysia over the period 1958-2007. Residual plots is used to measure the goodness of fit of the model. Fertility index forecast using random walk drift is then utilised to predict the future age specific fertility. Results indicate that the proposed model provides a relatively good and reasonable data fitting. In addition, there is an apparent and continuous decline in age specific fertility curves in the next 10 years, particularly among mothers' in their early 20's and 40's. The study on the fertility is vital in order to maintain a balance between the population growth and the provision of facilities related resources.

  1. Age-specific patterns of genetic variance in Drosophila melanogaster. I. Mortality

    SciTech Connect

    Promislow, D.E.L.; Tatar, M.; Curtsinger, J.W.

    1996-06-01

    Peter Medawar proposed that senescence arises from an age-related decline in the force of selection, which allows late-acting deleterious mutations to accumulate. Subsequent workers have suggested that mutation accumulation could produce an age-related increase in additive genetic variance (V{sub A}) for fitness traits, as recently found in Drosophila melanogaster. Here we report results from a genetic analysis of mortality in 65,134 D. melanogaster. Additive genetic variance for female mortality rates increases from 0.007 in the first week of life to 0.325 by the third week, and then declines to 0.002 by the seventh week. Males show a similar pattern, though total variance is lower than in females. In contrast to a predicted divergence in mortality curves, mortality curves of different genotypes are roughly parallel. Using a three-parameter model, we find significant V{sub A} for the slope and constant term of the curve describing age-specific mortality rates, and also for the rate at which mortality decelerates late in life. These results fail to support a prediction derived from Medawar`s {open_quotes}mutation accumulation{close_quotes} theory for the evolution of senescence. However, our results could be consistent with alternative interpretations of evolutionary models of aging. 65 refs., 2 figs., 2 tabs.

  2. Can you hear my age? Influences of speech rate and speech spontaneity on estimation of speaker age

    PubMed Central

    Skoog Waller, Sara; Eriksson, Mårten; Sörqvist, Patrik

    2015-01-01

    Cognitive hearing science is mainly about the study of how cognitive factors contribute to speech comprehension, but cognitive factors also partake in speech processing to infer non-linguistic information from speech signals, such as the intentions of the talker and the speaker’s age. Here, we report two experiments on age estimation by “naïve” listeners. The aim was to study how speech rate influences estimation of speaker age by comparing the speakers’ natural speech rate with increased or decreased speech rate. In Experiment 1, listeners were presented with audio samples of read speech from three different speaker age groups (young, middle aged, and old adults). They estimated the speakers as younger when speech rate was faster than normal and as older when speech rate was slower than normal. This speech rate effect was slightly greater in magnitude for older (60–65 years) speakers in comparison with younger (20–25 years) speakers, suggesting that speech rate may gain greater importance as a perceptual age cue with increased speaker age. This pattern was more pronounced in Experiment 2, in which listeners estimated age from spontaneous speech. Faster speech rate was associated with lower age estimates, but only for older and middle aged (40–45 years) speakers. Taken together, speakers of all age groups were estimated as older when speech rate decreased, except for the youngest speakers in Experiment 2. The absence of a linear speech rate effect in estimates of younger speakers, for spontaneous speech, implies that listeners use different age estimation strategies or cues (possibly vocabulary) depending on the age of the speaker and the spontaneity of the speech. Potential implications for forensic investigations and other applied domains are discussed. PMID:26236259

  3. Age-specific risk factors for lead absorption in children

    SciTech Connect

    Walter, S.D.; Yankel, A.J.; von Lindern, I.H.

    1980-01-01

    The relationship of blood lead levels to environmental and individual characteristics is analyzed in a large sample of children residing near a lead smelting complex, with particular emphasis on the identification of age-related risk factors. Exceptional variation in both blood leads and its determinants within the study region facilitated the simultaneous detection of several significant risk factors for each year of age from 1 to 9 y. The strongest predictor of blood lead at all ages was air lead, but the secondary risk factors were age dependent. Household dustiness was significantly related to blood lead in young children, especially those under 2 y of age; soil lead may be an important source of ingested lead for children between 2 and 7 y. Other significant effects included that of pica at about 2 y of age, a slight effect of the occupational category of the fathers of 5- to 8-y-old children, and a tendency for 8- and 9-y-old boys to have higher blood leads than girls of the same age. Lead concentration in household paint was not a significant risk factor. These results suggest that a multifactorial approach to the prevention of excessive lead absorption by children is required.

  4. Predicting mortality from burns: the need for age-group specific models.

    PubMed

    Taylor, Sandra L; Lawless, MaryBeth; Curri, Terese; Sen, Soman; Greenhalgh, David G; Palmieri, Tina L

    2014-09-01

    Traditional burn mortality models are derived using all age groups. We hypothesized that age variably impacts mortality after burn and that age-specific models for children, adults, and seniors will more accurately predict mortality than an all-ages model. We audited data from the American Burn Association (ABA) National Burn Repository (NBR) from 2000 to 2009 and used mixed effect logistic regression models to assess the influence of age, total body surface area (TBSA) burn, and inhalation injury on mortality. Mortality models were constructed for all ages and age-specific models: children (<18 years), adults (18-60 years), and seniors (>60 years). Model performance was assessed by area under the receiver operating curve (AUC). Main effect and two-way interactions were used to construct age-group specific mortality models. Each age-specific model was compared to the All Ages model. Of 286,293 records 100,051 had complete data. Overall mortality was 4% but varied by age (17% seniors, <1% children). Age, TBSA, and inhalation injury were significant mortality predictors for all models (p<0.05). Differences in predicted mortality between the All Ages model and the age-specific models occurred in children and seniors. In the age-specific pediatric model, predicted mortality decreased with age; inhalation injury had greater effect on mortality than in the All Ages model. In the senior model mortality increased with age. Seniors had greater increase in mortality per 1% increment in burn size and 1 year increase in age than other ages. The predicted mortality in seniors using the senior-specific model was higher than in the All Ages model. "One size fits all" models for predicting burn outcomes do not accurately reflect the outcomes for seniors and children. Age-specific models for children and seniors may be advisable. PMID:24846014

  5. Predicting Mortality from Burn Injuries: The need for age-group specific models

    PubMed Central

    Taylor, Sandra L.; Lawless, MaryBeth; Curri, Terese; Sen, Soman; Greenhalgh, David G.; Palmieri, Tina L.

    2014-01-01

    Traditional burn mortality models are derived using all age groups. We hypothesized that age variably impacts mortality after burn and that age-specific models for children, adults, and seniors will more accurately predict mortality than an all-ages model. We audited data from the American Burn Association (ABA) National Burn Repository (NBR) from 2000-2009 and used mixed effect logistic regression models to assess the influence of age, total body surface area (TBSA) burn, and inhalation injury on mortality. Mortality models were constructed for all ages and age-specific models: children (<18 years), adults (18-60 years), and seniors (>60 years). Model performance was assessed by area under the receiver operating curve (AUC). Main effect and two-way interactions were used to construct age-group specific mortality models. Each age-specific model was compared to the All Ages model. Of 286,293 records 100,051 had complete data. Overall mortality was 4% but varied by age (17% seniors, <1% children). Age, TBSA, and inhalation injury were significant mortality predictors for all models (p<0.05). Differences in predicted mortality between the All Ages model and the age-specific models occurred in children and seniors. In the age-specific pediatric model, predicted mortality decreased with age; inhalation injury had greater effect on mortality than in the All Ages model. In the senior model mortality increased with age. Seniors had greater increase in mortality per 1% increment in burn size and 1 year increase in age than other ages. The predicted mortality in seniors using the senior-specific model was higher than in the All Ages model. “One size fits all” models for predicting burn outcomes do not accurately reflect the outcomes for seniors and children. Age-specific models for children and seniors may be advisable. PMID:24846014

  6. Relations between Perceived Competence, Importance Ratings, and Self-Worth among African American School-Age Children

    ERIC Educational Resources Information Center

    Grier, Leslie K.

    2013-01-01

    The purpose of this research was to investigate how domain-specific importance ratings affect relations between perceived competence and self-worth among African American school-age children. Importance ratings have been found to affect the strength of the relationship between perceived competence and self-worth and have implications for…

  7. Age differences in personal values: Universal or cultural specific?

    PubMed

    Fung, Helene H; Ho, Yuan Wan; Zhang, Rui; Zhang, Xin; Noels, Kimberly A; Tam, Kim-Pong

    2016-05-01

    Prior studies on value development across adulthood have generally shown that as people age, they espouse communal values more strongly and agentic values less strongly. Two studies investigated whether these age differences in personal values might differ according to cultural values. Study 1 examined whether these age differences in personal values, and their associations with subjective well-being, showed the same pattern across countries that differed in individualism-collectivism. Study 2 compared age differences in personal values in the Canadian culture that emphasized agentic values more and the Chinese culture that emphasized communal values more. Personal and cultural values of each individual were directly measured, and their congruence were calculated and compared across age and cultures. Findings revealed that across cultures, older people had lower endorsement of agentic personal values and higher endorsement of communal personal values than did younger people. These age differences, and their associations with subjective well-being, were generally not influenced by cultural values. (PsycINFO Database Record PMID:26950224

  8. Age differences in personal values: Universal or cultural specific?

    PubMed

    Fung, Helene H; Ho, Yuan Wan; Zhang, Rui; Zhang, Xin; Noels, Kimberly A; Tam, Kim-Pong

    2016-05-01

    Prior studies on value development across adulthood have generally shown that as people age, they espouse communal values more strongly and agentic values less strongly. Two studies investigated whether these age differences in personal values might differ according to cultural values. Study 1 examined whether these age differences in personal values, and their associations with subjective well-being, showed the same pattern across countries that differed in individualism-collectivism. Study 2 compared age differences in personal values in the Canadian culture that emphasized agentic values more and the Chinese culture that emphasized communal values more. Personal and cultural values of each individual were directly measured, and their congruence were calculated and compared across age and cultures. Findings revealed that across cultures, older people had lower endorsement of agentic personal values and higher endorsement of communal personal values than did younger people. These age differences, and their associations with subjective well-being, were generally not influenced by cultural values. (PsycINFO Database Record

  9. The Influence of Subordinate Age on Performance Ratings and Causal Attributions.

    ERIC Educational Resources Information Center

    Ferris, Gerald R.; And Others

    1985-01-01

    Examined the role of subordinate age in performance evaluations. Results found that supervisors rated older subordinates lower than younger subordinates doing the same job; differences between self-ratings of performance and supervisory ratings seemed to be a function of the subordinate's age; and a significant age by performance interaction was…

  10. [Ambivalence, old age and agency: Meaning of age-specific ambivalence for the construction of narrative identity].

    PubMed

    Richter, Anna Sarah

    2016-01-01

    Different models of the formation of age identity explain the empirically determined difference between the chronological age and the age which is subjectively perceived by elderly people themselves. From a biographical point of view and on the basis of two maximally contrasting empirical cases, this article investigates the ways ambivalence appears in the narrations of elderly people about personal aging and the narrative strategies of coping with this experience of ambivalence. The results of the analysis indicate that the conceptualization of age identity in the different models should be seen more as descriptions of potential but not necessary forms of coping with age-specific ambivalences.

  11. Aged venous thrombi: radioimmunoimaging with fibrin-specific monoclonal antibody

    SciTech Connect

    Rosebrough, S.F.; Grossman, Z.D.; McAfee, J.G.; Kudryk, B.J.; Subramanian, G.; Ritter-Hrncirik, C.A.; Witanowski, L.S.; Tillapaugh-Fay, G.; Urrutia, E.

    1987-02-01

    Radioimmunoimaging of fresh canine venous thrombi with a murine monoclonal antibody specific for human and dog fibrin has been reported. Successful imaging of canine deep venous thrombi 1, 3, and 5 days old at the time of antibody injection is reported. Images were positive in all dogs, and the uptake of fibrin-specific antibody was equivalent to that of fresh thrombi.

  12. Phonological skills of children with specific expressive language impairment (SLI-E): outcome at age 3.

    PubMed

    Roberts, J; Rescorla, L; Giroux, J; Stevens, L

    1998-04-01

    Naturalistic speech samples of 29 3-year-olds diagnosed with specific expressive language delay (SU-E) were compared to those produced by 19 age-matched normally developing peers in order to determine their improvement in phonological skills since age 2, when Rescorla and Ratner (1996) studied them. Specifically, the groups were compared with regard to vocalization rate, verbalizations, fully intelligible utterances, phonetic inventories, percentages of consonants correct (PCC), phonological processes, and mean length of utterance (MLU). Results revealed that there was no significant difference between the groups in their numbers of vocalizations (as there had been at age 2), although there continued to be differences in their phonetic inventories, PCC scores, and overall intelligibility. These findings suggest that at age 2 the children with SU-E were not only less phonologically skilled but less talkative, whereas by age 3 they were equally vocal. Analysis of the phonetic inventories of the children demonstrated that for most consonants, the SLI-E group followed the some pattern of development as the comparison children, but more of the normally developing group had productive control of each consonant, consistent with findings of Rescorla and Ratner. There continued to be differences in intelligibility as measured by rates of verbalization (those utterances with at least one intelligible word) and fully intelligible utterances. Using these measures, we found that approximately half the SU-E children had caught up with their normally developing peers in terms of articulation, whereas half of them continued to be significantly delayed. Finally, although some of the late-bloomer group had caught up to the comparison children in language skills, as measured by MLU, many had not, suggesting that there was a tendency for the children to catch up in some articulation skills before catching up in language abilities. PMID:9570589

  13. Calculating summary statistics for population chemical biomonitoring in women of childbearing age with adjustment for age-specific natality.

    PubMed

    Axelrad, Daniel A; Cohen, Jonathan

    2011-01-01

    The effects of chemical exposures during pregnancy on children's health have been an increasing focus of environmental health research in recent years, leading to greater interest in biomonitoring of chemicals in women of childbearing age in the general population. Measurements of mercury in blood from the National Health and Nutrition Examination Survey are frequently reported for "women of childbearing age," defined to be of ages 16-49 years. The intent is to represent prenatal chemical exposure, but blood mercury levels increase with age. Furthermore, women of different ages have different probabilities of giving birth. We evaluated options to address potential bias in biomonitoring summary statistics for women of childbearing age by accounting for age-specific probabilities of giving birth. We calculated median and 95th percentile levels of mercury, PCBs, and cotinine using these approaches: option 1: women aged 16-49 years without natality adjustment; option 2: women aged 16-39 years without natality adjustment; option 3: women aged 16-49 years, adjusted for natality by age; option 4: women aged 16-49 years, adjusted for natality by age and race/ethnicity. Among the three chemicals examined, the choice of option has the greatest impact on estimated levels of serum PCBs, which are strongly associated with age. Serum cotinine levels among Black non-Hispanic women of childbearing age are understated when age-specific natality is not considered. For characterizing in utero exposures, adjustment using age-specific natality provides a substantial improvement in estimation of biomonitoring summary statistics. PMID:21035114

  14. Age-dependent tissue-specific exposure of cell phone users

    NASA Astrophysics Data System (ADS)

    Christ, Andreas; Gosselin, Marie-Christine; Christopoulou, Maria; Kühn, Sven; Kuster, Niels

    2010-04-01

    The peak spatial specific absorption rate (SAR) assessed with the standardized specific anthropometric mannequin head phantom has been shown to yield a conservative exposure estimate for both adults and children using mobile phones. There are, however, questions remaining concerning the impact of age-dependent dielectric tissue properties and age-dependent proportions of the skull, face and ear on the global and local absorption, in particular in the brain tissues. In this study, we compare the absorption in various parts of the cortex for different magnetic resonance imaging-based head phantoms of adults and children exposed to different models of mobile phones. The results show that the locally induced fields in children can be significantly higher (>3 dB) in subregions of the brain (cortex, hippocampus and hypothalamus) and the eye due to the closer proximity of the phone to these tissues. The increase is even larger for bone marrow (>10 dB) as a result of its significantly high conductivity. Tissues such as the pineal gland show no increase since their distances to the phone are not a function of age. This study, however, confirms previous findings saying that there are no age-dependent changes of the peak spatial SAR when averaged over the entire head.

  15. Estimating dose rates to organs as a function of age following internal exposure to radionuclides

    SciTech Connect

    Leggett, R.W.; Eckerman, K.F.; Dunning, D.E. Jr.; Cristy, M.; Crawford-Brown, D.J.; Williams, L.R.

    1984-03-01

    The AGEDOS methodology allows estimates of dose rates, as a function of age, to radiosensitive organs and tissues in the human body at arbitrary times during or after internal exposure to radioactive material. Presently there are few, if any, radionuclides for which sufficient metabolic information is available to allow full use of all features of the methodology. The intention has been to construct the methodology so that optimal information can be gained from a mixture of the limited amount of age-dependent, nuclide-specific data and the generally plentiful age-dependent physiological data now available. Moreover, an effort has been made to design the methodology so that constantly accumulating metabolic information can be incorporated with minimal alterations in the AGEDOS computer code. Some preliminary analyses performed by the authors, using the AGEDOS code in conjunction with age-dependent risk factors developed from the A-bomb survivor data and other studies, has indicated that the doses and subsequent risks of eventually experiencing radiogenic cancers may vary substantially with age for some exposure scenarios and may be relatively invariant with age for other scenarios. We believe that the AGEDOS methodology provides a convenient and efficient means for performing the internal dosimetry.

  16. A Stochastic Version of the Brass PF Ratio Adjustment of Age-Specific Fertility Schedules

    PubMed Central

    Baker, Jack; Alcantara, Adélamar; Ruan, Xiaomin

    2011-01-01

    Estimates of age-specific fertility rates based on survey data are known to suffer down-bias associated with incomplete reporting. Previously, William Brass (1964, 1965, 1968) proposed a series of adjustments of such data to reflect more appropriate levels of fertility through comparison with data on children-ever-born by age, a measure of cohort-specific cumulative fertility. His now widely-used Parity/Fertility or PF ratio method makes a number of strong assumptions, which have been the focus of an extended discussion in the literature on indirect estimation. However, while it is clear that the measures used in making adjusted age-specific fertility estimates with this method are captured with statistical uncertainty, little discussion of the nature of this uncertainty around PF-ratio based estimates of fertility has been entertained in the literature. Since both age-specific risk of childbearing and cumulative parity (children ever born) are measured with statistical uncertainty, an unknown credibility interval must surround every PF ratio-based estimate. Using the standard approach, this is unknown, limiting the ability to make statistical comparisons of fertility between groups or to understand stochasticity in population dynamics. This paper makes use of approaches applied to similar problems in engineering, the natural sciences, and decision analysis—often discussed under the title of uncertainty analysis or stochastic modeling—to characterize this uncertainty and to present a new method for making PF ratio-based fertility estimates with 95 percent uncertainty intervals. The implications for demographic analysis, between-group comparisons of fertility, and the field of statistical demography are explored. PMID:21829718

  17. Mathematical phantoms for evaluation of age-specific internal dose

    SciTech Connect

    Cristy, M.

    1980-01-01

    A series of mathematical phantoms representing children has been developed for use with photon transport codes. These phantoms, patterned after the Fisher-Snyder adult phantom, consist of simple mathematical expressions for the boundaries of the major organs and body sections. The location and shape of the organs are consistent with drawings depicting developmental anatomy, with the organ volumes assigned such that the masses at the various ages conform closely with the data presented in Reference Man. The explicit mathematical expressions for the various ages overcome the potential misrepresentation of organ sizes that occurred in phantoms derived from simple mathematical transformations of the adult phantom. Female breast tissue has been added to the phantoms, including the adult, now allowing assessment of doses to this organ.

  18. Lifestyle Modifications Versus Antihypertensive Medications in Reducing Cardiovascular Events in an Aging Society: A Success Rate-oriented Simulation.

    PubMed

    Ohno, Yoichi; Shibazaki, Satomi; Araki, Ryuichiro; Miyazaki, Takashi; Sato, Makiko; Takahashi, Sachiko; Suwa, Emi; Takenaka, Tsuneo; Suzuki, Hiromichi

    2016-01-01

    Objective It is difficult to compare directly the practical effects of lifestyle modifications and antihypertensive medications on reducing cardiovascular disease (CVD). The purpose of this study was to compare the hypothetical potential of lifestyle modifications with that of antihypertensive medications in reducing CVD in an aging society using a success rate-oriented simulation. Methods We constructed a simulation model for virtual Japanese subpopulations according to sex and age at 10-year intervals from 40 years of age as an example of an aging society. The fractional incidence rate of CVD was calculated as the product of the incidence rate at each systolic blood pressure (SBP) level and the proportion of the SBP frequency distribution in the fractional subpopulations of each SBP. The total incidence rate was calculated by the definite integral of the fractional incidence rate at each SBP level in the sex- and age-specific subpopulations. Results If we consider the effects of lifestyle modifications on metabolic factors and transfer them onto SBP, the reductions in the total incidence rate of CVD were competitive between lifestyle modifications and antihypertensive medications in realistic scenarios. In middle-aged women, the preventive effects of both approaches were limited due to a low incidence rate. In middle-aged men and extremely elderly subjects whose adherence to antihypertensive medications is predicted to be low, lifestyle modifications could be an alternative choice. Conclusion The success rate-oriented simulation suggests that the effectiveness of lifestyle modifications or antihypertensive medications in preventing cardiovascular events largely depends on the baseline incidence rate and sex- and age-specific behavioral factors. PMID:27522993

  19. Osteocalcin and bone-specific alkaline phosphatase in Asian elephants (Elephas maximus) at different ages.

    PubMed

    Arya, Nlin; Moonarmart, Walasinee; Cheewamongkolnimit, Nareerat; Keratikul, Nutcha; Poon-Iam, Sawinee; Routh, Andrew; Bumpenpol, Pitikarn; Angkawanish, Taweepoke

    2015-11-01

    Bone turnover markers could offer a potential alternative means for the early diagnosis of metabolic bone disease in young growing elephants although the baseline of bone turnover markers in elephant is not well established. The aim of this study was to determine any relationship between the age of captive Asian elephants (Elephas maximus) and markers of bone formation. Serum samples from 24 female Asian elephants were collected to evaluate levels of two bone formation markers, namely, osteocalcin (OC) and bone-specific alkaline phosphatase (BAP). Both intact and N-terminal midfragment OC and BAP were negatively correlated with age. The findings demonstrate that younger elephants have a higher rate of bone turnover than older elephants. Use of these and additional bone markers could lead to the establishment of validated protocols for the monitoring of bone disease in elephants. PMID:26361748

  20. Enhancement of germination rate of aged seeds by ethylene.

    PubMed

    Takayanagi, K; Harrington, J F

    1971-04-01

    Naturally and artificially aged seeds of rape, Brassica napus L., produced less ethylene than freshly harvested seed during the early stage of germination. With freshly harvested seeds one peak of ethylene production was observed during germination, which coincided with the emergence and elongation of root and cotyledon, accompanied by splitting of the seed coat. Application of exogenous ethylene was effective in accelerating germination in aged seeds but did not significantly improve the percentage of germination. Ethylene as a hormone was considered to serve as a stimulator of germination and growth. One of the factors causing seed aging might be the degeneration of an ethylene-producing system in the seed. Exogenous ethylene may be effective only for the seeds in which the ethylene-producing system is weakened but the following responding systems are still functional.

  1. Age-specific breeding success in a wild mammalian population: selection, constraint, restraint and senescence.

    PubMed

    Dugdale, Hannah L; Pope, Lisa C; Newman, Chris; Macdonald, David W; Burke, Terry

    2011-08-01

    The Selection, Constraint, Restraint and Senescence Hypotheses predict how breeding success should vary with age. The Selection Hypothesis predicts between-individual variation arising from quality differences; the other hypotheses predict within-individual variation due to differing skills or physiological condition (Constraint), residual reproductive lifespan (Restraint), or somatic and reproductive investment (Senescence). Studies tend to focus on either the initial increase in breeding success or later decrease; however, both require consideration when unravelling the underlying evolutionary processes. Additionally, few studies present genetic fitness measures and rarely for both sexes. We therefore test these four hypotheses, which are not mutually exclusive, in a high-density population of European badgers Meles meles. Using an 18-year data set (including 22 microsatellite loci), we show an initial improvement in breeding success with age, followed by a later and steeper rate of reproductive senescence in male than in female badgers. Breeding success was skewed within age-classes, indicating the influence of factors other than age-class. This was partly attributable to selective appearance and disappearance of badgers (Selection Hypothesis). Individuals with a late age of last breeding showed a concave-down relationship between breeding success and experience (Constraint Hypothesis). There was no evidence of abrupt terminal effects; rather, individuals showed a concave-down relationship between breeding success and residual reproductive lifespan (Restraint Hypothesis), with an interaction with age of first breeding only in female badgers. Our results demonstrate the importance of investigating a comprehensive suite of factors in age-specific breeding success analyses, in both sexes, to fully understand evolutionary and population dynamics. PMID:21714821

  2. The ligand activity of AGE-proteins to scavenger receptors is dependent on their rate of modification by AGEs.

    PubMed

    Nagai, Ryoji; Mera, Katsumi; Nakajou, Keisuke; Fujiwara, Yukio; Iwao, Yasunori; Imai, Hiroki; Murata, Toshinori; Otagiri, Masaki

    2007-12-01

    The cellular interaction of proteins modified with advanced glycation end-products (AGEs) is believed to induce several different biological responses, which are involved in the development of diabetic vascular complications. We report here that the ratio of protein glycation is implicated in its ligand activity to scavenger receptors. Although highly-modified AGE-bovine serum albumin (high-AGE-BSA) was significantly recognized by human monocyte-derived macrophages and Chinese hamster ovary cells which overexpress such scavenger receptors as CD36, SR-BI (scavenger receptor class B type-I), and LOX-1 (Lectin-like Ox-LDL receptor-1), the mildly-modified-AGE-BSA (mild-AGE-BSA) did not show any ligand activity to these cells. Furthermore, when (111)In-labeled high- or mild-AGE-BSA were injected into the tail vein of mice, the high-AGE-BSA was rapidly cleared from the circulation whereas the clearance rate of the mild-AGE-BSA was very slow, similar to the native BSA. These results demonstrate the first evidence that the ligand activity of the AGE-proteins to the scavenger receptors and its pharmacokinetic properties depend on their rate of modification by AGEs, and we should carefully prepare the AGE-proteins in vitro to clarify the physiological significance of the interaction between the AGE-receptors and AGE-proteins.

  3. Age-specific patterns of genetic variance in Drosophila melanogaster. II. Fecundity and its genetic covariance with age-specific mortality

    SciTech Connect

    Tatar, M.; Promislow, D.E.L.; Khazaeli, A.A.; Curtsinger, J.W.

    1996-06-01

    Under the mutation accumulation model of senescence, it was predicted that the additive genetic variance (V{sub A}) for fitness traits will increase with age. We measured age-specific mortality and fecundity from 65,134 Drosophila melanogaster and estimated genetic variance components, based on reciprocal crosses of extracted second chromosome lines. Elsewhere we report the results for mortality. Here, for fecundity, we report a biomodal pattern for V{sub A} with peaks at 3 days and at 17-31 days. Under the antagonistic pleiotropy model of senescence, it was predicted that negative correlations will exist between early and late life history traits. For fecundity itself we find positive genetic correlations among age classes >3 days but negative nonsignificant correlations between fecundity at 3 days and at older age classes. For fecundity vs. age-specific mortality, we find positive fitness correlations (negative genetic correlations) among the traits at all ages >3 days but a negative fitness correlation between fecundity at 3 days and mortality at the oldest ages (positive genetic correlations). For age-specific mortality itself we find overwhelmingly positive genetic correlations among all age classes. The data suggest that mutation accumulation may be a major source of standing genetic variance for senescence. 75 refs., 4 figs., 1 tab.

  4. Autobiographical Memory Specificity among Preschool-Aged Children

    ERIC Educational Resources Information Center

    Nuttall, Amy K.; Valentino, Kristin; Comas, Michelle; McNeill, Anne T.; Stey, Paul C.

    2014-01-01

    "Overgeneral memory" refers to difficulty retrieving specific autobiographical memories and is consistently associated with depression and/or trauma. The present study developed a downward extension of the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986) given the need to document normative developmental changes in…

  5. [Rate of erythrocyte sedimentation in buffaloes in related to age].

    PubMed

    d'Angelo, A; Zicarelli, L; Damiano, B; Avallone, L; Crasto, A

    1984-03-30

    The behavior of the ERS was studied in water buffalo of both sexes from one week to nine years of age. A progressive and considerable increase in the values of the ERS, with a respective increase in the animal's age, was noted. Concerning the factors conditioning such peculiarities, the authors attribute importance to the following items: the number of erythrocytes, the plasmatic viscosity, and the total proteinemia (especially in the region of the gamma-globulins that, among those taken in the study, exhibited the greatest variations).

  6. Prototype Operational Advances for Atmospheric Radiation Dose Rate Specification

    NASA Astrophysics Data System (ADS)

    Tobiska, W. K.; Bouwer, D.; Bailey, J. J.; Didkovsky, L. V.; Judge, K.; Garrett, H. B.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R. W.; Bell, D.; Mertens, C. J.; Xu, X.; Crowley, G.; Reynolds, A.; Azeem, I.; Wiltberger, M. J.; Wiley, S.; Bacon, S.; Teets, E.; Sim, A.; Dominik, L.

    2014-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. The coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has developed innovative, new space weather observations that will become part of the toolset that is transitioned into operational use. One prototype operational system for providing timely information about the effects of space weather is SET's Automated Radiation Measurements for Aerospace Safety (ARMAS) system. ARMAS will provide the "weather" of the radiation environment to improve aircraft crew and passenger safety. Through several dozen flights the ARMAS project has successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time via Iridium satellites, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. We are extending the dose measurement domain above commercial aviation altitudes into the stratosphere with a collaborative project organized by NASA's Armstrong Flight Research Center (AFRC) called Upper-atmospheric Space and Earth Weather eXperiment (USEWX). In USEWX we will be flying on the ER-2 high altitude aircraft a micro dosimeter for

  7. Professor Age Affects Student Ratings: Halo Effect for Younger Teachers

    ERIC Educational Resources Information Center

    Wilson, Janie H.; Beyer, Denise; Monteiro, Heather

    2014-01-01

    Student evaluations of teaching provide valued information about teaching effectiveness, and studies support the reliability and validity of such measures. However, research also illustrates potential moderation of student perceptions based on teacher gender, attractiveness, and even age, although the latter receives little research attention. In…

  8. 47 CFR 51.509 - Rate structure standards for specific elements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall...

  9. 47 CFR 51.509 - Rate structure standards for specific elements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall...

  10. 47 CFR 51.509 - Rate structure standards for specific elements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall...

  11. 47 CFR 51.509 - Rate structure standards for specific elements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall...

  12. Control of Rate-Bounded Hybrid Systems with Liveness Specifications

    NASA Technical Reports Server (NTRS)

    Heymann, Michael; Lin, Feng; Meyer, George

    1998-01-01

    In the present paper we examine the control problem for a class of composite hybrid machines (CHMs) that consist of concurrent operation (employing synchronous composition) of elementary hybrid machines (EHMs), that allows both signal sharing and event synchronization. A controller can then be coupled with the plant by means of synchronous composition. We confine our attention to controllers that interact with the system only through event synchronization. We present an initial investigation of synthesis of liveness controllers for hybrid machines. To this end we define open hybrid machines as systems that can interact with the environment through event synchronization and can be therefor be "driven" to their marked configuration by user (controller). Liveness specifications must be associated with timing constraints. We may require that for a specified time limit, every run reach a marked configuration within that time limit. Alternatively, a more relaxed specification may be that, for some (unspecified) global time bound, every run of the system reach a marked configuration within that time bound. Finally, the least restrictive liveness requirement is that every run reach a marked configuration within a finite time limit (but we do not insist on the existence of a global time bound for all runs).

  13. Measuring aging rates of mice subjected to caloric restriction and genetic disruption of growth hormone signaling.

    PubMed

    Koopman, Jacob J E; van Heemst, Diana; van Bodegom, David; Bonkowski, Michael S; Sun, Liou Y; Bartke, Andrzej

    2016-03-01

    Caloric restriction and genetic disruption of growth hormone signaling have been shown to counteract aging in mice. The effects of these interventions on aging are examined through age-dependent survival or through the increase in age-dependent mortality rates on a logarithmic scale fitted to the Gompertz model. However, these methods have limitations that impede a fully comprehensive disclosure of these effects. Here we examine the effects of these interventions on murine aging through the increase in age-dependent mortality rates on a linear scale without fitting them to a model like the Gompertz model. Whereas these interventions negligibly and non-consistently affected the aging rates when examined through the age-dependent mortality rates on a logarithmic scale, they caused the aging rates to increase at higher ages and to higher levels when examined through the age-dependent mortality rates on a linear scale. These results add to the debate whether these interventions postpone or slow aging and to the understanding of the mechanisms by which they affect aging. Since different methods yield different results, it is worthwhile to compare their results in future research to obtain further insights into the effects of dietary, genetic, and other interventions on the aging of mice and other species.

  14. Measuring aging rates of mice subjected to caloric restriction and genetic disruption of growth hormone signaling

    PubMed Central

    Koopman, Jacob J.E.; van Heemst, Diana; van Bodegom, David; Bonkowski, Michael S.; Sun, Liou Y.; Bartke, Andrzej

    2016-01-01

    Caloric restriction and genetic disruption of growth hormone signaling have been shown to counteract aging in mice. The effects of these interventions on aging are examined through age-dependent survival or through the increase in age-dependent mortality rates on a logarithmic scale fitted to the Gompertz model. However, these methods have limitations that impede a fully comprehensive disclosure of these effects. Here we examine the effects of these interventions on murine aging through the increase in age-dependent mortality rates on a linear scale without fitting them to a model like the Gompertz model. Whereas these interventions negligibly and non-consistently affected the aging rates when examined through the age-dependent mortality rates on a logarithmic scale, they caused the aging rates to increase at higher ages and to higher levels when examined through the age-dependent mortality rates on a linear scale. These results add to the debate whether these interventions postpone or slow aging and to the understanding of the mechanisms by which they affect aging. Since different methods yield different results, it is worthwhile to compare their results in future research to obtain further insights into the effects of dietary, genetic, and other interventions on the aging of mice and other species. PMID:26959761

  15. Sex-specific age association with primary DNA transfer.

    PubMed

    Manoli, Panayiotis; Antoniou, Antonis; Bashiardes, Evy; Xenophontos, Stavroulla; Photiades, Marinos; Stribley, Vaso; Mylona, Michalis; Demetriou, Christiana; Cariolou, Marios A

    2016-01-01

    Practicing forensic scientists who are called to provide expert witness testimony are often asked to explain both the presence and the absence of DNA on objects that have been handled by perpetrators with bare hands. Unwashed hands, depending on what they have come in contact with previously, may become the vehicle of both primary and secondary transfer of DNA. In this study, we investigated the propensity of primary and secondary transfer of DNA from unwashed bare hands of 128 individuals onto plastic tubes. Our experiments, carried out in triplicate, have shown that DNA was not detected on all the touched tubes, secondary transfer of DNA, through unwashed hands, was small, and in the majority of cases primary DNA transfer could be distinguished from secondary DNA transfer. A statistically significant association was demonstrated between percent DNA profile deposited on plastic tubes, through unwashed hands, and the age of male individuals. PMID:26582043

  16. Sex-specific age association with primary DNA transfer.

    PubMed

    Manoli, Panayiotis; Antoniou, Antonis; Bashiardes, Evy; Xenophontos, Stavroulla; Photiades, Marinos; Stribley, Vaso; Mylona, Michalis; Demetriou, Christiana; Cariolou, Marios A

    2016-01-01

    Practicing forensic scientists who are called to provide expert witness testimony are often asked to explain both the presence and the absence of DNA on objects that have been handled by perpetrators with bare hands. Unwashed hands, depending on what they have come in contact with previously, may become the vehicle of both primary and secondary transfer of DNA. In this study, we investigated the propensity of primary and secondary transfer of DNA from unwashed bare hands of 128 individuals onto plastic tubes. Our experiments, carried out in triplicate, have shown that DNA was not detected on all the touched tubes, secondary transfer of DNA, through unwashed hands, was small, and in the majority of cases primary DNA transfer could be distinguished from secondary DNA transfer. A statistically significant association was demonstrated between percent DNA profile deposited on plastic tubes, through unwashed hands, and the age of male individuals.

  17. ALGORITHMS FOR ESTIMATING RESTING METABOLIC RATE AND ACTIVITY SPECIFIC VENTILATION RATES FOR USE IN COMPLEX EXPOSURE AND INTAKE DOSE MODELS

    EPA Science Inventory

    This work summarizes advancements made that allow for better estimation of resting metabolic rate (RMR) and subsequent estimation of ventilation rates (i.e., total ventilation (VE) and alveolar ventilation (VA)) for individuals of both genders and all ages. ...

  18. Age-Related Differences in Speech Rate Perception Do Not Necessarily Entail Age-Related Differences in Speech Rate Use

    ERIC Educational Resources Information Center

    Heffner, Christopher C.; Newman, Rochelle S.; Dilley, Laura C.; Idsardi, William J.

    2015-01-01

    Purpose: A new literature has suggested that speech rate can influence the parsing of words quite strongly in speech. The purpose of this study was to investigate differences between younger adults and older adults in the use of context speech rate in word segmentation, given that older adults perceive timing information differently from younger…

  19. Domain-Specific Impulsivity in School-Age Children

    PubMed Central

    Tsukayama, Eli; Duckworth, Angela Lee; Kim, Betty

    2013-01-01

    Impulsivity is a salient individual difference in children with well-established predictive validity for life outcomes. The current investigation proposes that impulsive behaviors vary systematically by domain. In a series of studies with ethnically and socioeconomically diverse samples of middle school students, we find that schoolwork-related and interpersonal-related impulsivity, as observed by teachers, parents, and the students themselves, are distinct, moderately correlated behavioral tendencies. Each demonstrates differentiated relationships with dimensions of childhood temperament, Big Five personality factors, and outcomes, such as sociometric popularity, report card grades, and classroom conduct. Implications for theoretical conceptions of impulsivity as well as for practical applications (e.g., domain-specific interventions) are discussed. PMID:24118714

  20. Parents' and Teachers' Ratings of the Social Skills of Elementary-Age Students Who Are Blind.

    ERIC Educational Resources Information Center

    Buhrow, Melissa M.; Hartshorne, Timothy S.; Bradley-Johnson, Sharon

    1998-01-01

    Ratings by 23 parents and 21 regular education teachers of 20 elementary-aged students with blindness on the Social Skills Rating Scale (SSRS) were compared to ratings for the SSRS sighted-norm group. Although no significant differences were found for overall ratings, students with blindness were rated as less academically competent and higher on…

  1. Fetal autonomic brain age scores, segmented heart rate variability analysis, and traditional short term variability

    PubMed Central

    Hoyer, Dirk; Kowalski, Eva-Maria; Schmidt, Alexander; Tetschke, Florian; Nowack, Samuel; Rudolph, Anja; Wallwitz, Ulrike; Kynass, Isabelle; Bode, Franziska; Tegtmeyer, Janine; Kumm, Kathrin; Moraru, Liviu; Götz, Theresa; Haueisen, Jens; Witte, Otto W.; Schleußner, Ekkehard; Schneider, Uwe

    2014-01-01

    Disturbances of fetal autonomic brain development can be evaluated from fetal heart rate patterns (HRP) reflecting the activity of the autonomic nervous system. Although HRP analysis from cardiotocographic (CTG) recordings is established for fetal surveillance, temporal resolution is low. Fetal magnetocardiography (MCG), however, provides stable continuous recordings at a higher temporal resolution combined with a more precise heart rate variability (HRV) analysis. A direct comparison of CTG and MCG based HRV analysis is pending. The aims of the present study are: (i) to compare the fetal maturation age predicting value of the MCG based fetal Autonomic Brain Age Score (fABAS) approach with that of CTG based Dawes-Redman methodology; and (ii) to elaborate fABAS methodology by segmentation according to fetal behavioral states and HRP. We investigated MCG recordings from 418 normal fetuses, aged between 21 and 40 weeks of gestation. In linear regression models we obtained an age predicting value of CTG compatible short term variability (STV) of R2 = 0.200 (coefficient of determination) in contrast to MCG/fABAS related multivariate models with R2 = 0.648 in 30 min recordings, R2 = 0.610 in active sleep segments of 10 min, and R2 = 0.626 in quiet sleep segments of 10 min. Additionally segmented analysis under particular exclusion of accelerations (AC) and decelerations (DC) in quiet sleep resulted in a novel multivariate model with R2 = 0.706. According to our results, fMCG based fABAS may provide a promising tool for the estimation of fetal autonomic brain age. Beside other traditional and novel HRV indices as possible indicators of developmental disturbances, the establishment of a fABAS score normogram may represent a specific reference. The present results are intended to contribute to further exploration and validation using independent data sets and multicenter research structures. PMID:25505399

  2. Constraining age and rate of deformation in the northern Bolivian Andes from cross sections, cooling ages, and thermokinematic modeling

    NASA Astrophysics Data System (ADS)

    McQuarrie, N.; Ehlers, T. A.; Rak, A. J.

    2015-12-01

    A critical component in assessing the viability of proposed plate tectonic or geodynamic processes in regions of convergence is the expected or predicted age and rate of deformation in the overriding plate. Commonly, age of deformation is inferred through geochronology of foreland basin and wedge-top sedimentary rocks and bedrock thermochronometer cooling signals. In Bolivia the original pulse of deformation of the fold-thrust belt is argue to be as young as 38-25 Ma based on the age of synorogenic strata or as old as 65-45 Ma due to proposed foreland basin rocks deposited in the Bolivian Altiplano. The large discrepancies in proposed age, rate and magnitude of deformation through the Bolivian Andes limit our ability to relate age and rate of shortening to internal geodynamic or external plate tectonic processes. We evaluate permissible ranges in age of initiation and rate of deformation through a forward kinematic model of the northern Bolivian fold-thrust belt. Each step of deformation accounts for isostatic loading from thrust faults and subsequent erosional of structural highs. The kinematic model predicts an evolution of flexural basins into which synorogenic sediments are deposited allowing us to fully integrate age of exhumation and deposition to age and magnitude of deformation. By assigning an age to each deformation step, we create a range of velocity vectors that are input into the thermokinematic model Pecube, which predicts thermochronometer cooling histories based on kinematics, topography, thermal parameters and shortening rates. We match the pattern of predicted ages with the across strike pattern of measured zircon fission track, apatite fission track and apatite (U-Th)/ He cooling ages. The sensitivity of modeled thermochronologic data to the age at which deformation initiates indicate that northern Bolivian EC started deforming at 50 Ma and may have begun as early as 55 Ma. The acceptable velocity envelope for the modeled section permits either a

  3. Comparison of whole saliva flow rates and mucin concentrations in healthy Caucasian young and aged adults.

    PubMed

    Navazesh, M; Mulligan, R A; Kipnis, V; Denny, P A; Denny, P C

    1992-06-01

    Unstimulated and chewing-stimulated whole saliva samples were obtained from 42 healthy Caucasians; 21 were between 18 and 35 years of age, and 21 between 65 and 83 years of age. The unstimulated salivary flow rate was significantly lower in the aged group, but the stimulated flow rate was significantly higher in the aged than in the young group. Both groups showed significantly increased flow during salivary stimulation. MG1 and MG2 concentrations in unstimulated and stimulated saliva samples were significantly lower in the aged group. There were no significant correlations between salivary flow rates and MG1 and MG2 concentrations.

  4. High Basal Metabolic Rate Is a Risk Factor for Mortality: The Baltimore Longitudinal Study of Aging

    PubMed Central

    Ruggiero, Carmelinda; Metter, E. Jeffrey; Melenovsky, Vojtech; Cherubini, Antonio; Najjar, Samer S.; Ble, Alessandro; Senin, Umberto; Longo, Dan L.; Ferrucci, Luigi

    2016-01-01

    Background Despite longstanding controversies from animal studies on the relationship between basal metabolic rate (BMR) and longevity, whether BMR is a risk factor for mortality has never been tested in humans. We evaluate the longitudinal changes in BMR and the relationship between BMR and mortality in the Baltimore Longitudinal Study of Aging (BLSA) participants. Methods BMR and medical information were collected at the study entry and approximately every 2 years in 1227 participants (972 men) over a 40-year follow-up. BMR, expressed as kcal/m2/h, was estimated from the basal O2 consumption and CO2 production measured by open-circuit method. Data on all-cause and specific-cause mortality were also obtained. Result BMR declined with age at a rate that accelerated at older ages. Independent of age, participants who died had a higher BMR compared to those who survived. BMR was a significant risk factor for mortality independent of secular trends in mortality and other well-recognized risk factors for mortality, such as age, body mass index, smoking, white blood cell count, and diabetes. BMR was nonlinearly associated with mortality. The lowest mortality rate was found in the BMR range 31.3–33.9 kcal/m2/h. Participants with BMR in the range 33.9–36.4 kcal/m2/h and above the threshold of 36.4 kcal/m2/h experienced 28% (hazard ratio: 1.28; 95% confidence interval, 1.02–1.61) and 53% (hazard ratio: 1.53; 95% confidence interval, 1.19–1.96) higher mortality risk compared to participants with BMR 31.3–33.9 kcal/m2/h. Conclusion We confirm previous findings of an age-related decline of BMR. In our study, a blunted age-related decline in BMR was associated with higher mortality, suggesting that such condition reflects poor health status. PMID:18693224

  5. Competition, breeding success and ageing rates in female meerkats.

    PubMed

    Sharp, S P; Clutton-Brock, T H

    2011-08-01

    Competition between females is particularly intense in cooperatively breeding mammals, where one female monopolises reproduction in each group. Chronic competition often affects stress and may therefore have long-term consequences for fitness, but no studies have yet investigated whether intrasexual competition has effects of this kind and, in particular, whether it affects rates of reproductive senescence. Here, we use long-term data from a wild population of meerkats to test whether reproductive success and senescence in dominant females are affected by the degree of intrasexual competition experienced prior to dominance acquisition. Females that experienced greater competition had lower breeding success and higher rates of reproductive senescence. Furthermore, females that were evicted from the group more frequently as subordinates had lower breeding success when dominant. We conclude that the intense intrasexual competition between females in cooperatively breeding groups may carry fitness costs over a longer period than is usually recognised.

  6. Competition, breeding success and ageing rates in female meerkats.

    PubMed

    Sharp, S P; Clutton-Brock, T H

    2011-08-01

    Competition between females is particularly intense in cooperatively breeding mammals, where one female monopolises reproduction in each group. Chronic competition often affects stress and may therefore have long-term consequences for fitness, but no studies have yet investigated whether intrasexual competition has effects of this kind and, in particular, whether it affects rates of reproductive senescence. Here, we use long-term data from a wild population of meerkats to test whether reproductive success and senescence in dominant females are affected by the degree of intrasexual competition experienced prior to dominance acquisition. Females that experienced greater competition had lower breeding success and higher rates of reproductive senescence. Furthermore, females that were evicted from the group more frequently as subordinates had lower breeding success when dominant. We conclude that the intense intrasexual competition between females in cooperatively breeding groups may carry fitness costs over a longer period than is usually recognised. PMID:21599775

  7. Relationship of Bacterial Richness to Organic Degradation Rate and Sediment Age in Subseafloor Sediment

    PubMed Central

    Walsh, Emily A.; Kirkpatrick, John B.; Pockalny, Robert; Sauvage, Justine; Spivack, Arthur J.; Murray, Richard W.; Sogin, Mitchell L.

    2016-01-01

    ABSTRACT Subseafloor sediment hosts a large, taxonomically rich, and metabolically diverse microbial ecosystem. However, the factors that control microbial diversity in subseafloor sediment have rarely been explored. Here, we show that bacterial richness varies with organic degradation rate and sediment age. At three open-ocean sites (in the Bering Sea and equatorial Pacific) and one continental margin site (Indian Ocean), richness decreases exponentially with increasing sediment depth. The rate of decrease in richness with increasing depth varies from site to site. The vertical succession of predominant terminal electron acceptors correlates with abundance-weighted community composition but does not drive the vertical decrease in richness. Vertical patterns of richness at the open-ocean sites closely match organic degradation rates; both properties are highest near the seafloor and decline together as sediment depth increases. This relationship suggests that (i) total catabolic activity and/or electron donor diversity exerts a primary influence on bacterial richness in marine sediment and (ii) many bacterial taxa that are poorly adapted for subseafloor sedimentary conditions are degraded in the geologically young sediment, where respiration rates are high. Richness consistently takes a few hundred thousand years to decline from near-seafloor values to much lower values in deep anoxic subseafloor sediment, regardless of sedimentation rate, predominant terminal electron acceptor, or oceanographic context. IMPORTANCE Subseafloor sediment provides a wonderful opportunity to investigate the drivers of microbial diversity in communities that may have been isolated for millions of years. Our paper shows the impact of in situ conditions on bacterial community structure in subseafloor sediment. Specifically, it shows that bacterial richness in subseafloor sediment declines exponentially with sediment age, and in parallel with organic-fueled oxidation rate. This result

  8. Penetration rates over 30 years in the space age

    NASA Technical Reports Server (NTRS)

    Mcdonnell, J. A. M.; Baron, J. M.

    1995-01-01

    Experimental data from spacecraft providing impact penetration rates and cratering for metallic targets is reviewed. Data includes NASA Explorers 16 and 23 and the Pegasus series, the second US-UK satellite Ariel 2, Space Shuttle STS-3 (MFE), recovered surfaces on Solar Max Satellite, The Long Duration Exposure Facility (LDEF) and EuReCa TiCCE. Factors concerning exposure to the environment are considered and, especially, material properties which affect the penetration resistance. Reference to a common material, Aluminum alloy 2024-T3, is effected and the data then compared to define firstly an average impact flux over the period. The data is examined, in the context of possible satellite and space debris growth rates, to determine the constancy of the flux. This also provides strong constraints on the current space debris component. It is found that the impact data are consistent with domination by natural meteoroid sources. Growth rates are not evident within the period 1980-1990 and Eureca TiCCE fluxes in 1993, for particles penetrating foils of around 10 microns thickness, supports the constancy of the flux. At larger dimensions the 1993 Eureca TiCCE fluxes show an 8-fold increase but this is considered not inconsistent with the selective exposure to meteoroid streams of a satellite stabilized in heliocentric co-ordinates for an 11 month period.

  9. Effect of Temperature on the Aging rate of Li Ion Battery Operating above Room Temperature

    PubMed Central

    Leng, Feng; Tan, Cher Ming; Pecht, Michael

    2015-01-01

    Temperature is known to have a significant impact on the performance, safety, and cycle lifetime of lithium-ion batteries (LiB). However, the comprehensive effects of temperature on the cyclic aging rate of LiB have yet to be found. We use an electrochemistry-based model (ECBE) here to measure the effects on the aging behavior of cycled LiB operating within the temperature range of 25 °C to 55 °C. The increasing degradation rate of the maximum charge storage of LiB during cycling at elevated temperature is found to relate mainly to the degradations at the electrodes, and that the degradation of LCO cathode is larger than graphite anode at elevated temperature. In particular, the formation and modification of the surface films on the electrodes as well as structural/phase changes of the LCO electrode, as reported in the literatures, are found to be the main contributors to the increasing degradation rate of the maximum charge storage of LiB with temperature for the specific operating temperature range. Larger increases in the Warburg elements and cell impedance are also found with cycling at higher temperature, but they do not seriously affect the state of health (SoH) of LiB as shown in this work. PMID:26245922

  10. Development of Planning Abilities in Normal Aging: Differential Effects of Specific Cognitive Demands

    ERIC Educational Resources Information Center

    Köstering, Lena; Stahl, Christoph; Leonhart, Rainer; Weiller, Cornelius; Kaller, Christoph P.

    2014-01-01

    In line with the frontal hypothesis of aging, the ability to plan ahead undergoes substantial change during normal aging. Although impairments on the Tower of London planning task were reported earlier, associations between age-related declines and specific cognitive demands on planning have not been studied. Here we investigated the impact of…

  11. "Life Stage-Specific" Variations in Performance in Response to Age Stereotypes

    ERIC Educational Resources Information Center

    Hehman, Jessica A.; Bugental, Daphne Blunt

    2013-01-01

    In a test of life stage-specific responses to age-based stigma, older (n = 54, ages 62-92) and younger (n = 81, ages 17-22) adults were told that a task (Weschler Adult Intelligence Scale-III block design) required either (a) speed/contemporary knowledge (YA; "youth advantage") or (b) life experience/wisdom (OA; "age…

  12. Changes in Cesarean Delivery Rates by Gestational Age: United States, 1996-2011

    MedlinePlus

    ... Cesarean delivery rates at 38 weeks declined for all maternal age groups, but increased at 39 weeks. ... Cesarean delivery rates at 38 weeks declined for all racial and ethnic groups, but rose at 39 ...

  13. Gestational age-specific associations between infantile acute bronchiolitis and asthma after age five

    PubMed Central

    Strickland, Matthew J.; Marsh, Caitlin A.; Darrow, Lyndsey A.

    2014-01-01

    Background Infantile acute bronchiolitis is a risk factor for the development of pediatric asthma. The associations might differ according to gestational age. Methods Datasets of emergency department (ED) visits (Jan 2002 to June 2010) and live birth records (Jan 2002 to Dec 2004) from the state of Georgia were linked for all children who survived one year. Exposure was an ED visit for acute bronchiolitis during infancy (AB), and the outcome was an ED visit for asthma after age five years. The risk of asthma among children with AB (n = 11,564) was compared with the risk of asthma among children who did not have an ED visit for AB but who utilized the ED for another reason during infancy (n = 131,694). Associations were estimated using log-binomial regression models that controlled for several plausible confounders. Effect measure modification of the risk ratio by gestational age was investigated. Results Crude asthma risks (per 100 children) through June 2010 were 4.5 for children with AB and 2.3 for children without AB. The adjusted risk ratio for the overall association was 1.89 (95% confidence interval (CI) 1.73, 2.108). We did not observe effect modification of the risk ratio by gestational age. Conclusion A positive association was observed between ED visits for AB and subsequent asthma ED visits after age five; associations did not vary meaningfully by gestational age. Sensitivity analyses did not suggest large biases due to differences in ED utilization across socio-demographic groups or loss to follow-up from residential migration. PMID:25256755

  14. Age, Race and Regional Disparities in Colorectal Cancer Incidence Rates in Georgia between 2000 and 2012

    PubMed Central

    Yoo, Wonsuk; De, Subhendu; Wilkins, Thad; Smith, Selina A.; Blumenthal, Daniel

    2016-01-01

    Colorectal cancer (CRC) incidence rates and mortality have been decreasing in the United States. Currently, states in the South have the smallest reduction in CRC mortality. The trends of CRC incidence rates in Georgia in comparison to the United States have not been investigated. We analyzed age-adjusted incidence rates of CRC in Georgia and the United States from 2000 to 2012 using data from SEER 18 registries. Age-adjusted incidence rates (95% CI) were calculated as cases per 100,000 to the 2000 US Standard population. CRC incidence rates were calculated for groupings based on age at time of diagnosis, race, sex, and geographic location within Georgia. Incidence rates were higher in males compared to females in Georgia. In Georgians age 50–64, incidence rates were higher compared to the US, while those ages 65+ displayed lower incidence rates. Black Georgians age 50–64 generally exhibited higher incidence rates of CRC and lower rates of decrease in incidence compared to other races in Georgia. Asian/Pacific Islander females age 50–64 in Georgia exhibited an increasing trend in incidence rate. Whites and blacks Georgians age 50–64 displayed higher incidence rates compared to the US, while Asian/Pacific Islanders displayed lower incidence rates. Greater incidence rates of CRC in rural and Greater Georgia were seen across all races when compared to overall rates in Georgia. Efforts should be made to address disparities in Georgia based on race and geographic location. Increased screening by colonoscopy or fecal occult blood testing, reduction of risk factors and promotion of healthy lifestyles can reduce CRC incidence rates. PMID:27042701

  15. Context-specific influence of water temperature on brook trout growth rates in the field

    USGS Publications Warehouse

    Xu, C.; Letcher, B.H.; Nislow, K.H.

    2010-01-01

    1. Modelling the effects of climate change on freshwater fishes requires robust field-based estimates accounting for interactions among multiple factors.2. We used data from an 8-year individual-based study of a wild brook trout (Salvelinus fontinalis) population to test the influence of water temperature on season-specific growth in the context of variation in other environmental (i.e. season, stream flow) or biotic factors (local brook trout biomass density and fish age and size) in West Brook, a third-order stream in western Massachusetts, U.S.A.3. Changes in ambient temperature influenced individual growth rates. In general, higher temperatures were associated with higher growth rates in winter and spring and lower growth rates in summer and autumn. However, the effect of temperature on growth was strongly context-dependent, differing in both magnitude and direction as a function of season, stream flow and fish biomass density.4. We found that stream flow and temperature had strong and complex interactive effects on trout growth. At the coldest temperatures (in winter), high stream flows were associated with reduced trout growth rates. During spring and autumn and in typical summers (when water temperatures were close to growth optima), higher flows were associated with increased growth rates. In addition, the effect of flow at a given temperature (the flow-temperature interaction) differed among seasons.5. Trout density negatively affected growth rate and had strong interactions with temperature in two of four seasons (i.e. spring and summer) with greater negative effects at high temperatures.6. Our study provided robust, integrative field-based estimates of the effects of temperature on growth rates for a species which serves as a model organism for cold-water adapted ectotherms facing the consequences of environmental change. Results of the study strongly suggest that failure to derive season-specific estimates, or to explicitly consider interactions with

  16. Age Dependence and Isotype Specificity of Influenza Virus Hemagglutinin Stalk-Reactive Antibodies in Humans

    PubMed Central

    Nachbagauer, Raffael; Choi, Angela; Izikson, Ruvim; Cox, Manon M.; Palese, Peter

    2016-01-01

    ABSTRACT Influenza remains a major global health burden. Seasonal vaccines offer protection but can be rendered less effective when the virus undergoes extensive antigenic drift. Antibodies that target the highly conserved hemagglutinin stalk can protect against drifted viruses, and vaccine constructs designed to induce such antibodies form the basis for a universal influenza virus vaccine approach. In this study, we analyzed baseline and postvaccination serum samples of children (6 to 59 months), adults (18 to 49 years), and elderly individuals (≥65 years) who participated in clinical trials with a recombinant hemagglutinin-based vaccine. We found that baseline IgG and IgA antibodies against the H1 stalk domain correlated with the ages of patients. Children generally had very low baseline titers and did not respond well to the vaccine in terms of making stalk-specific antibodies. Adults showed the highest induction of stalk-specific antibodies, but the elderly had the highest absolute antibody titers against the stalk. Importantly, the stalk antibodies measured by enzyme-linked immunosorbent assay (ELISA) showed neutralizing activity in neutralization assays and protected mice in a passive-transfer model in a stalk titer-dependent manner. Finally, we found similar patterns of stalk-specific antibodies directed against the H3 and influenza B virus hemagglutinins, albeit at lower levels than those measured against the H1 stalk. The relatively high levels of stalk-specific antibodies in the elderly patients may explain the previously reported low influenza virus infection rates in this age group. (This study has been registered at ClinicalTrials.gov under registration no. NCT00336453, NCT00539981, and NCT00395174.) PMID:26787832

  17. Role of metabolic rate and DNA-repair in Drosophila aging Implications for the mitochondrial mutation theory of aging

    NASA Technical Reports Server (NTRS)

    Miquel, J.; Binnard, R.; Fleming, J. E.

    1983-01-01

    The notion that injury to mitochondrial DNA is a cause of intrinsic aging was tested by correlating the different respiration rates of several wild strains of Drosophila melanogaster with the life-spans. Respiration rate and aging in a mutant of D. melanogaster deficient in postreplication repair were also investigated. In agreement with the rate of living theory, there was an inverse relation between oxygen consumption and median life-span in flies having normal DNA repair. The mutant showed an abnormally low life-span as compared to the controls and also exhibited significant deficiency in mating fitness and a depressed metabolic rate. Therefore, the short life-span of the mutant may be due to the congenital condition rather than to accelerated aging.

  18. Branch age and light conditions determine leaf-area-specific conductivity in current shoots of Scots pine.

    PubMed

    Grönlund, Leila; Hölttä, Teemu; Mäkelä, Annikki

    2016-08-01

    Shoot size and other shoot properties more or less follow the availability of light, but there is also evidence that the topological position in a tree crown has an influence on shoot development. Whether the hydraulic properties of new shoots are more regulated by the light or the position affects the shoot acclimation to changing light conditions and thereby to changing evaporative demand. We investigated the leaf-area-specific conductivity (and its components sapwood-specific conductivity and Huber value) of the current-year shoots of Scots pine (Pinus sylvestris L.) in relation to light environment and topological position in three different tree classes. The light environment was quantified in terms of simulated transpiration and the topological position was quantified by parent branch age. Sample shoot measurements included length, basal and tip diameter, hydraulic conductivity of the shoot, tracheid area and density, and specific leaf area. In our results, the leaf-area-specific conductivity of new shoots declined with parent branch age and increased with simulated transpiration rate of the shoot. The relation to transpiration demand seemed more decisive, since it gave higher R(2) values than branch age and explained the differences between the tree classes. The trend of leaf-area-specific conductivity with simulated transpiration was closely related to Huber value, whereas the trend of leaf-area-specific conductivity with parent branch age was related to a similar trend in sapwood-specific conductivity. PMID:27217528

  19. Branch age and light conditions determine leaf-area-specific conductivity in current shoots of Scots pine.

    PubMed

    Grönlund, Leila; Hölttä, Teemu; Mäkelä, Annikki

    2016-08-01

    Shoot size and other shoot properties more or less follow the availability of light, but there is also evidence that the topological position in a tree crown has an influence on shoot development. Whether the hydraulic properties of new shoots are more regulated by the light or the position affects the shoot acclimation to changing light conditions and thereby to changing evaporative demand. We investigated the leaf-area-specific conductivity (and its components sapwood-specific conductivity and Huber value) of the current-year shoots of Scots pine (Pinus sylvestris L.) in relation to light environment and topological position in three different tree classes. The light environment was quantified in terms of simulated transpiration and the topological position was quantified by parent branch age. Sample shoot measurements included length, basal and tip diameter, hydraulic conductivity of the shoot, tracheid area and density, and specific leaf area. In our results, the leaf-area-specific conductivity of new shoots declined with parent branch age and increased with simulated transpiration rate of the shoot. The relation to transpiration demand seemed more decisive, since it gave higher R(2) values than branch age and explained the differences between the tree classes. The trend of leaf-area-specific conductivity with simulated transpiration was closely related to Huber value, whereas the trend of leaf-area-specific conductivity with parent branch age was related to a similar trend in sapwood-specific conductivity.

  20. Human dental age estimation using third molar developmental stages: Accuracy of age predictions not using country specific information.

    PubMed

    Thevissen, P W; Alqerban, A; Asaumi, J; Kahveci, F; Kaur, J; Kim, Y K; Pittayapat, P; Van Vlierberghe, M; Zhang, Y; Fieuws, S; Willems, G

    2010-09-10

    Unquestionable forensic age investigations are based on statistical models constructed on a sample containing subjects of identical origin as the examined individual. In cases where corresponding models are unavailable, the established report has to describe the possible effects of this unrelated information on the predicted age outcome. The aim of this study is to collect country specific databases of third molar development and to verify how the related dental age estimations are influenced if we were to use dental developmental information only from Belgium or from all collected countries together. Data containing third molar developmental stages scored following Gleiser and Hunt (modified by Köhler) were collected from 9 country specific populations (Belgium, China, Japan, Korea, Poland, Thailand, Turkey, Saudi-Arabia and South-India). Age predictions were obtained from a training dataset and validated on a test dataset. Bayes rule using the repeated third molar scores is applied to get age predictions and prediction intervals. Three age predictions were compared for males and females separately. For the first prediction, the training dataset contains only Belgian subjects. For the second prediction, the training dataset for each country consists only of subjects of the country itself. For the final prediction, subjects from all countries are pooled into one common training dataset. Besides the (absolute) difference between the chronological age and the predicted age, specific interest lies in the juvenile-adult distinction. In the age range from 16 to 22 years 6982 subjects (3189 male and 3793 female) were analyzed. Using information on third molar development from Belgium compared to information from the country specific databases hardly increased the mean absolute differences (MAD) and mean squared errors (MSE): the MAD and MSE increased on average with 0.5 and 2.5 months with maximal increases of, respectively 1.6 and 7.3 months. Using information from all

  1. Human dental age estimation using third molar developmental stages: Accuracy of age predictions not using country specific information.

    PubMed

    Thevissen, P W; Alqerban, A; Asaumi, J; Kahveci, F; Kaur, J; Kim, Y K; Pittayapat, P; Van Vlierberghe, M; Zhang, Y; Fieuws, S; Willems, G

    2010-09-10

    Unquestionable forensic age investigations are based on statistical models constructed on a sample containing subjects of identical origin as the examined individual. In cases where corresponding models are unavailable, the established report has to describe the possible effects of this unrelated information on the predicted age outcome. The aim of this study is to collect country specific databases of third molar development and to verify how the related dental age estimations are influenced if we were to use dental developmental information only from Belgium or from all collected countries together. Data containing third molar developmental stages scored following Gleiser and Hunt (modified by Köhler) were collected from 9 country specific populations (Belgium, China, Japan, Korea, Poland, Thailand, Turkey, Saudi-Arabia and South-India). Age predictions were obtained from a training dataset and validated on a test dataset. Bayes rule using the repeated third molar scores is applied to get age predictions and prediction intervals. Three age predictions were compared for males and females separately. For the first prediction, the training dataset contains only Belgian subjects. For the second prediction, the training dataset for each country consists only of subjects of the country itself. For the final prediction, subjects from all countries are pooled into one common training dataset. Besides the (absolute) difference between the chronological age and the predicted age, specific interest lies in the juvenile-adult distinction. In the age range from 16 to 22 years 6982 subjects (3189 male and 3793 female) were analyzed. Using information on third molar development from Belgium compared to information from the country specific databases hardly increased the mean absolute differences (MAD) and mean squared errors (MSE): the MAD and MSE increased on average with 0.5 and 2.5 months with maximal increases of, respectively 1.6 and 7.3 months. Using information from all

  2. Increases in Cognitive and Linguistic Processing Primarily Account for Increases in Speaking Rate with Age

    ERIC Educational Resources Information Center

    Nip, Ignatius S. B.; Green, Jordan R.

    2013-01-01

    Age-related increases of speaking rate are not fully understood, but have been attributed to gains in biologic factors and learned skills that support speech production. This study investigated developmental changes in speaking rate and articulatory kinematics of participants aged 4 ("N" = 7), 7 ("N" = 10), 10…

  3. Speaking Rate Characteristics of Elementary-School-Aged Children Who Do and Do Not Stutter

    ERIC Educational Resources Information Center

    Logan, Kenneth J.; Byrd, Courtney T.; Mazzocchi, Elizabeth M.; Gillam, Ronald B.

    2011-01-01

    Purpose: To compare articulation and speech rates of school-aged children who do and do not stutter across sentence priming, structured conversation, and narration tasks and to determine factors that predict children's speech and articulation rates. Method: 34 children who stutter (CWS) and 34 age- and gender-matched children who do not stutter…

  4. Age-of-Recall Effects on Family-of-Origin Ratings.

    ERIC Educational Resources Information Center

    Hampson, Robert B.; And Others

    1994-01-01

    College students (n=141) completed Self-Report Family Inventory on Beavers Systems Model of Family Functioning, rating current family, family when they were 10 years old, and family when they were 16 years old. Found significant differences between age-of-recall groups, with recall ratings from age 10 significantly more competent, cohesive, and…

  5. The Gulf War era multiple sclerosis cohort: age and incidence rates by race, sex and service.

    PubMed

    Wallin, Mitchell T; Culpepper, William J; Coffman, Parisa; Pulaski, Sarah; Maloni, Heidi; Mahan, Clare M; Haselkorn, Jodie K; Kurtzke, John F

    2012-06-01

    We characterize here a new nationwide incident cohort of multiple sclerosis from the US military-veteran population. This cohort provides an update to the only other US nationwide incidence study of multiple sclerosis performed during the 1970s. Medical records and data from the Department of Defense and Department of Veterans Affairs for cases of multiple sclerosis who served in the military between 1990, the start of the Gulf War era, and 2007 and who were service-connected for this disorder by the Department of Veterans Affairs from 1990 on, were reviewed. A total of 2691 patients were confirmed as having multiple sclerosis: 2288 definite, 190 possible, 207 clinically isolated syndrome and six neuromyelitis optica. Overall racial categories were White, Black and other, which included all Hispanics. There were 1278 White males and 556 females; 360 Black males and 296 females; and 200 others, 153 (77%) of whom were Hispanic. Mean age at onset of 30.7 years did not differ significantly by race or sex. Age at onset was 17-50 years in 99%, the same age range as 99% of the military. Average annual age specific (age 17-50 years) incidence rates per 100 000 for the entire series were 9.6 with 95% confidence interval of 9.3-10.0. Rates for Blacks were highest at 12.1 with confidence interval 11.2-13.1, Whites were 9.3 (interval 8.9-9.8) and others 6.9 (interval 6.0-7.9). For 83 Hispanics defined for 2000-07, the rate was 8.2 (interval 6.5-10.1). Much smaller numbers gave rates of 3.3 for Asian/Pacific Islanders and 3.1 for native Americans. Rates by sex for Whites were 7.3 and 25.8 male and female, respectively, for Blacks 8.4 and 26.3, and for Hispanics 6.6 and 17.0. Rates by service were high for Air Force (10.9) and Army (10.6), medium for Navy (9.1) and Coast Guard (7.9), and low for Marines (5.3). Relative risk of multiple sclerosis was 3.39 female:male and 1.27 Black:White. These new findings indicate that females of all races now have incidence rates for multiple

  6. The Gulf War era multiple sclerosis cohort: age and incidence rates by race, sex and service.

    PubMed

    Wallin, Mitchell T; Culpepper, William J; Coffman, Parisa; Pulaski, Sarah; Maloni, Heidi; Mahan, Clare M; Haselkorn, Jodie K; Kurtzke, John F

    2012-06-01

    We characterize here a new nationwide incident cohort of multiple sclerosis from the US military-veteran population. This cohort provides an update to the only other US nationwide incidence study of multiple sclerosis performed during the 1970s. Medical records and data from the Department of Defense and Department of Veterans Affairs for cases of multiple sclerosis who served in the military between 1990, the start of the Gulf War era, and 2007 and who were service-connected for this disorder by the Department of Veterans Affairs from 1990 on, were reviewed. A total of 2691 patients were confirmed as having multiple sclerosis: 2288 definite, 190 possible, 207 clinically isolated syndrome and six neuromyelitis optica. Overall racial categories were White, Black and other, which included all Hispanics. There were 1278 White males and 556 females; 360 Black males and 296 females; and 200 others, 153 (77%) of whom were Hispanic. Mean age at onset of 30.7 years did not differ significantly by race or sex. Age at onset was 17-50 years in 99%, the same age range as 99% of the military. Average annual age specific (age 17-50 years) incidence rates per 100 000 for the entire series were 9.6 with 95% confidence interval of 9.3-10.0. Rates for Blacks were highest at 12.1 with confidence interval 11.2-13.1, Whites were 9.3 (interval 8.9-9.8) and others 6.9 (interval 6.0-7.9). For 83 Hispanics defined for 2000-07, the rate was 8.2 (interval 6.5-10.1). Much smaller numbers gave rates of 3.3 for Asian/Pacific Islanders and 3.1 for native Americans. Rates by sex for Whites were 7.3 and 25.8 male and female, respectively, for Blacks 8.4 and 26.3, and for Hispanics 6.6 and 17.0. Rates by service were high for Air Force (10.9) and Army (10.6), medium for Navy (9.1) and Coast Guard (7.9), and low for Marines (5.3). Relative risk of multiple sclerosis was 3.39 female:male and 1.27 Black:White. These new findings indicate that females of all races now have incidence rates for multiple

  7. Toward an alternative representation for disentangling age-associated differences in general and specific cognitive abilities.

    PubMed

    Schmiedek, Florian; Li, Shu-Chen

    2004-03-01

    Much of cognitive aging research concerns whether age-associated differences in various cognitive performances can be accounted for by general explanatory constructs or whether several specific processes are involved. Structural equation models have been proposed to disentangle general and specific age-associated differences in cognitive performance. This article demonstrates that existing methods that employ stepwise procedures run the risk of biasing results toward general resource accounts. An alternative model representation (i.e., the nested factor model) is proposed that affords simultaneous estimation of general and specific effects and is applied to data from the Berlin Aging Study. Using the nested factor model allowed the authors to detect that specific group factors explained 25% of the age-associated variance in addition to the general factor.

  8. Soccer-Specific Warm-Up and Lower Extremity Injury Rates in Collegiate Male Soccer Players

    PubMed Central

    Grooms, Dustin R.; Palmer, Thomas; Onate, James A.; Myer, Gregory D.; Grindstaff, Terry

    2013-01-01

    Context: A number of comprehensive injury-prevention programs have demonstrated injury risk-reduction effects but have had limited adoption across athletic settings. This may be due to program noncompliance, minimal exercise supervision, lack of exercise progression, and sport specificity. A soccer-specific program described as the F-MARC 11+ was developed by an expert group in association with the Federation Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) to require minimal equipment and implementation as part of regular soccer training. The F-MARC 11+ has been shown to reduce injury risk in youth female soccer players but has not been evaluated in an American male collegiate population. Objective: To investigate the effects of a soccer-specific warm-up program (F-MARC 11+) on lower extremity injury incidence in male collegiate soccer players. Design: Cohort study. Setting: One American collegiate soccer team followed for 2 seasons. Patients or Other Participants: Forty-one male collegiate athletes aged 18–25 years. Intervention(s): The F-MARC 11+ program is a comprehensive warm-up program targeting muscular strength, body kinesthetic awareness, and neuromuscular control during static and dynamic movements. Training sessions and program progression were monitored by a certified athletic trainer. Main Outcome Measure(s): Lower extremity injury risk and time lost to lower extremity injury. Results: The injury rate in the referent season was 8.1 injuries per 1000 exposures with 291 days lost and 2.2 injuries per 1000 exposures and 52 days lost in the intervention season. The intervention season had reductions in the relative risk (RR) of lower extremity injury of 72% (RR = 0.28, 95% confidence interval = 0.09, 0.85) and time lost to lower extremity injury (P < .01). Conclusions: This F-MARC 11+ program reduced overall risk and severity of lower extremity injury compared with controls in collegiate-aged male soccer

  9. Speech Disruptions in the Sentence Formulation of School-Age Children with Specific Language Impairment

    PubMed Central

    Leonard, Laurence B.; Miller, Carol A.

    2009-01-01

    Background Many school-age children with specific language impairment (SLI)produce sentences that appear to conform to the adult grammar. It may be premature to conclude from this, however, that their language formulation ability is age appropriate. Aims In this study, we sought to determine whether a more subtle measure of language use, speech disruptions during sentence formulation, might serve to distinguish children with SLI from their typically-developing (TD) peers at an age when grammatical accuracy was high. We analyzed the rate of speech disruptions in simple sentence production in school-age children with SLI and TD age-matched peers. We predicted that (1) the SLI group would exhibit more speech disruptions than the TD group as a result of reduced language proficiency even when grammatical accuracy was high and, (2) the SLI group would demonstrate greater reductions in disruption frequency as compared to the TD group when given sentences that model the target syntactic structures. Methods & Procedures Twenty-eight children (17 SLI, 11 TD, M = 8;10 years) with no history of stuttering were presented with a series of picture pairs. The examiner described the first picture using a simple sentence and asked the child to repeat the sentence; the child then described the second picture. There were two priming conditions: Matching Syntax condition (paired pictures requiring the same syntactic structure) and Different Syntax condition (paired pictures requiring different syntactic structures). All testing was audio-recorded and speech disruptions (repetitions, revisions, fillers, long silent pauses) were transcribed and tabulated for each target response. The data were analyzed in an analysis of variance (ANOVA). Outcomes & Results T he SLI group demonstrated a significantly greater number of speech disruptions when compared to the TD group. There was no effect for priming. Conclusions & Implications School-age children with SLI appear to have difficulty with

  10. Hepatitis A virus age-specific sero-prevalence and risk factors among Jordanian children.

    PubMed

    Hayajneh, Wail A; Balbeesi, Adel; Faouri, Samir

    2015-04-01

    Hepatitis A Virus (HAV) has been a significant cause of infections among the children and adolescents of Jordan. Availability of safe vaccines made it necessary to identify the ill-defined temporal immunity trends for HAV and possible age-specific prevalence transitions. This community-based cross sectional study was conducted during the period July-August 2008 on 3,066 recruited subjects from the 12 governorates of Jordan, with pre-defined criteria. Several households were chosen at random within each selected block to enroll the subjects. They were interviewed and data were collected. Their sera were tested for total antibodies against HAV. A multivariate model was then performed to identify the possible risk factors. The HAV sero-prevalence rates among the age categories-second year, 2-4 years, 5-9 years, 10-14 years, 15-19 years, and those above 20 years were 26%, 32%, 44%, 63%, 78%, and 94%, respectively. The model revealed the association of several risk factors for higher HAV sero-prevalence rates: (i) older age groups; (ii) lower maternal education levels; (iii) residing in certain governorates; (iv) using public net drinking water; and (v) avoiding use of public net sewage system. This study provided strong evidence for continuous transition of HAV epidemiology towards intermediate endemicity in Jordan, with more susceptible adolescents and adults. Following the World Health Organization (WHO) recommendations for countries with intermediate endemicity, large-scale hepatitis A vaccination is recommended for children in Jordan. This is strengthened by the availability of effective and safe HAV vaccines, improving the socio-economic status of the Jordanians, and increasing life expectancy among Jordanians.

  11. Effect of Temperature on the Rate of Ageing: An Experimental Study of the Blowfly Calliphora stygia

    PubMed Central

    Kelly, Megan A.; Zieba, Adam P.; Buttemer, William A.; Hulbert, A. J.

    2013-01-01

    All organisms age, the rate of which can be measured by demographic analysis of mortality rates. The rate of ageing is thermally sensitive in ectothermic invertebrates and we examined the effects of temperature on both demographic rates of ageing and on cellular senescence in the blowfly, Calliphora stygia. The short lifespan of these flies is advantageous for demographic measurements while their large body size permits individual-based biochemical characterisation. Blowflies maintained at temperatures from 12°C to 34°C had a five to six-fold decrease in maximum and average longevity, respectively. Mortality rates were best described by a two-phase Gompertz relation, which revealed the first-phase of ageing to be much more temperature sensitive than the second stage. Flies held at low temperatures had both a slower first-phase rate of ageing and a delayed onset of second-phase ageing, which significantly extended their longevity compared with those at high temperatures. Blowflies that were transferred from 29°C to 15°C had higher first-phase mortality rates than those of flies held at constant 15°C, but their onset of second-phase ageing was deferred beyond that of flies held constantly at this temperature. The accumulation of fluorescent AGE pigment, a measure of cellular oxidative damage, increased steadily over time in all blowflies, irrespective of the temporal pattern of mortality. Pigment accumulated steadily during periods of ‘negligible senescence’, as measured by minimal rate of mortality, and the rate of accumulation was significantly affected by temperature. Thus accumulation of AGE pigment is more representative of chronological age than a reflection of biological age or a cause of mortality. PMID:24019937

  12. Age-specific reproduction in female sea otters (Enhydra lutris) from south-central Alaska: analysis of reproductive tracts

    USGS Publications Warehouse

    Bodkin, J.; Mulcahy, D.; Lensink, C.

    1993-01-01

    We estimated age at sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from south-central Alaska, Primarily from western Prince William Sound, as a result of the T/V Exxon Valdez oit spill in 1989. We found 65% of our sample to be sexually mature. Sexual maturity was first attained at age 2. The proportion of sexually mature animals increased from 30% at age 2 to 100% at age 5. Annual reproductive rates increased from 22% at age 2 to 78% at age 5 and remained relatively stable (75-88%) through to age 15. the sex ratio (female:male) of 49 fetal sea otters was 18:37 and differed significantly from parity. Females younger than 8 tended to produce more female fetuses, while older mothers did not. Our estimates of the reproductive characteristics of female sea otters obtained by examination of reproductive tracts wre similiar to those reported in the literature based on in situ observations of marked individuals.

  13. The dissimilar costs of love and war: age-specific mortality as a function of the operational sex ratio.

    PubMed

    Adler, M I; Bonduriansky, R

    2011-06-01

    Lifespan and ageing are strongly affected by many environmental factors, but the effects of social environment on these life-history traits are not well understood. We examined effects of social interaction on age-specific mortality rate in the sexually dimorphic neriid fly Telostylinus angusticollis. We found that although interaction with other individuals reduced longevity of both sexes, the costs associated with variation in operational sex ratio were sex specific: males' early-life mortality rate increased, and lifespan decreased, with increasing male bias in the sex ratio, whereas surprisingly, the presence of males had no effect on early-life mortality or lifespan of females. Intriguingly, early-life (immediate) mortality costs did not covary with late-life (latent) costs. Rather, both sexes aged most rapidly in a social environment dominated by the opposite sex. Our findings suggest that distinct reproductive activities, such as mating and fighting, impose different age-specific patterns of mortality, and that such costs are strongly sex specific.

  14. Professor Age and Research Assistant Ratings of Passive-Avoidant and Proactive Leadership: The Role of Age-Related Work Concerns and Age Stereotypes

    ERIC Educational Resources Information Center

    Zacher, Hannes; Bal, P. Matthijs

    2012-01-01

    Recent research has shown that, in general, older professors are rated to have more passive-avoidant leadership styles than younger professors by their research assistants. The current study investigated professors' age-related work concerns and research assistants' favorable age stereotypes as possible explanations for this finding. Data came…

  15. Analysis of mortality trends by specific ethnic groups and age groups in Malaysia

    NASA Astrophysics Data System (ADS)

    Ibrahim, Rose Irnawaty; Siri, Zailan

    2014-07-01

    The number of people surviving until old age has been increasing worldwide. Reduction in fertility and mortality have resulted in increasing survival of populations to later life. This study examines the mortality trends among the three main ethnic groups in Malaysia, namely; the Malays, Chinese and Indians for four important age groups (adolescents, adults, middle age and elderly) for both gender. Since the data on mortality rates in Malaysia is only available in age groups such as 1-5, 5-9, 10-14, 15-19 and so on, hence some distribution or interpolation method was essential to expand it to the individual ages. In the study, the Heligman and Pollard model will be used to expand the mortality rates from the age groups to the individual ages. It was found that decreasing trend in all age groups and ethnic groups. Female mortality is significantly lower than male mortality, and the difference may be increasing. Also the mortality rates for females are different than that for males in all ethnic groups, and the difference is generally increasing until it reaches its peak at the oldest age category. Due to the decreasing trend of mortality rates, the government needs to plan for health program to support more elderly people in the coming years.

  16. Rates of stillbirth by gestational age and cause in Inuit and First Nations populations in Quebec

    PubMed Central

    Auger, Nathalie; Park, Alison L.; Zoungrana, Hamado; McHugh, Nancy Gros-Louis; Luo, Zhong-Cheng

    2013-01-01

    Background: Inuit and First Nations populations have higher rates of stillbirth than non-Aboriginal populations in Canada do, but little is known about the timing and cause of stillbirth in Aboriginal populations. We compared gestational age– and cause-specific stillbirth rates in Inuit and First Nations populations with the rates in the non-Aboriginal population in Quebec. Methods: Data included singleton stillbirths and live births at 24 or more gestational weeks among Quebec residents from 1981 to 2009. We calculated odds ratios (ORs), rate differences and 95% confidence intervals (CIs) for the retrospective cohort of Inuit and First Nations births relative to non-Aboriginal births using fetuses at risk (i.e., ongoing pregnancies) as denominators and adjusting for maternal characteristics. The main outcomes were stillbirth by gestational age (24–27, 28–36, ≥ 37 wk) and cause of death. Results: Rates of stillbirth per 1000 births were greater among Inuit (6.8) and First Nations (5.7) than among non-Aboriginal (3.6) residents. Relative to the non-Aboriginal population, the risk of stillbirth was greater at term (≥ 37 wk) than before term for both Inuit (OR 3.1, 95% CI 1.9 to 4.8) and First Nations (OR 2.6, 95% CI 2.1 to 3.3) populations. Causes most strongly associated with stillbirth were poor fetal growth, placental disorders and congenital anomalies among the Inuit, and hypertension and diabetes among the First Nations residents. Interpretation: Stillbirth rates in Aboriginal populations were particularly high at term gestation. Poor fetal growth, placental disorders and congenital anomalies were important causes of stillbirth among the Inuit, and diabetic and hypertensive complications were important causes in the First Nations population. Prevention may require improvements in pregnancy and obstetric care. PMID:23422443

  17. Targeting tissue-specific metabolic signaling pathways in aging: the promise and limitations.

    PubMed

    Hu, Fang; Liu, Feng

    2014-01-01

    It has been well established that most of the age-related diseases such as insulin resistance, type 2 diabetes, hypertension, cardiovascular disease, osteoporosis, and atherosclerosis are all closely related to metabolic dysfunction. On the other hand, interventions on metabolism such as calorie restriction or genetic manipulations of key metabolic signaling pathways such as the insulin and mTOR signaling pathways slow down the aging process and improve healthy aging. These findings raise an important question as to whether improving energy homeostasis by targeting certain metabolic signaling pathways in specific tissues could be an effective anti-aging strategy. With a more comprehensive understanding of the tissue-specific roles of distinct metabolic signaling pathways controlling energy homeostasis and the cross-talks between these pathways during aging may lead to the development of more effective therapeutic interventions not only for metabolic dysfunction but also for aging.

  18. Prostate-Specific Antigen Bounce After High-Dose-Rate Monotherapy for Prostate Cancer

    SciTech Connect

    Mehta, Niraj H.; Kamrava, Mitchell; Wang, Pin-Chieh; Steinberg, Michael; Demanes, Jeffrey

    2013-07-15

    Purpose: To characterize the magnitude and kinetics of prostate-specific antigen (PSA) bounces after high-dose-rate (HDR) monotherapy and determine relationships between certain clinical factors and PSA bounce. Methods and Materials: Longitudinal PSA data and various clinical parameters were examined in 157 consecutive patients treated with HDR monotherapy between 1996 and 2005. We used the following definition for PSA bounce: rise in PSA ≥threshold, after which it returns to the prior level or lower. Prostate-specific antigen failure was defined per the Phoenix definition (nadir +2 ng/mL). Results: A PSA bounce was noted in 67 patients (43%). The number of bounces per patient was 1 in 45 cases (67%), 2 in 19 (28%), 3 in 2 (3%), 4 in 0, and 5 in 1 (1%). The median time to maximum PSA bounce was 1.3 years, its median magnitude was 0.7, and its median duration was 0.75 years. Three patients (2%) were noted to have PSA failure. None of the 3 patients who experienced biochemical failure exhibited PSA bounce. In the fully adjusted model for predicting each bounce, patients aged <55 years had a statistically significant higher likelihood of experiencing a bounce (odds ratio 2.22, 95% confidence interval 1.38-3.57, P=.001). There was also a statistically significant higher probability of experiencing a bounce for every unit decrease in Gleason score (odds ratio 1.52, 95% confidence interval 1.01-2.04, P=.045). Conclusions: A PSA bounce occurs in a significant percentage of patients treated with HDR monotherapy, with magnitudes varying from <1 in 28% of cases to ≥1 in 15%. The median duration of bounce is <1 year. More bounces were identified in patients with lower Gleason score and age <55 years. Further investigation using a model to correlate magnitude and frequency of bounces with clinical variables are under way.

  19. Cause-specific mortality rates in sub-Saharan Africa and Bangladesh.

    PubMed Central

    Adjuik, Martin; Smith, Tom; Clark, Sam; Todd, Jim; Garrib, Anu; Kinfu, Yohannes; Kahn, Kathy; Mola, Mitiki; Ashraf, Ali; Masanja, Honorati; Adazu, Kubaje; Adazu, Ubaje; Sacarlal, Jahit; Alam, Nurul; Marra, Adama; Gbangou, Adjima; Mwageni, Eleuther; Binka, Fred

    2006-01-01

    OBJECTIVE: To provide internationally comparable data on the frequencies of different causes of death. METHODS: We analysed verbal autopsies obtained during 1999 -2002 from 12 demographic surveillance sites in sub-Saharan Africa and Bangladesh to find cause-specific and age-specific mortality rates. The cause-of-death codes used by the sites were harmonized to conform to the ICD-10 system, and summarized with the classification system of the Global Burden of Disease 2000 (Version 2). FINDINGS: Causes of death in the African sites differ strongly from those in Bangladesh, where there is some evidence of a health transition from communicable to noncommunicable diseases, and little malaria. HIV dominates in causes of mortality in the South African sites, which contrast with those in highly malaria endemic sites elsewhere in sub-Saharan Africa (even in neighbouring Mozambique). The contributions of measles and diarrhoeal diseases to mortality in sub-Saharan Africa are lower than has been previously suggested, while malaria is of relatively greater importance. CONCLUSION: The different patterns of mortality we identified may be a result of recent changes in the availability and effectiveness of health interventions against childhood cluster diseases. PMID:16583076

  20. Real-Time Language Processing in School-Age Children with Specific Language Impairment

    ERIC Educational Resources Information Center

    Montgomery, James W.

    2006-01-01

    Background:School-age children with specific language impairment (SLI) exhibit slower real-time (i.e. immediate) language processing relative to same-age peers and younger, language-matched peers. Results of the few studies that have been done seem to indicate that the slower language processing of children with SLI is due to inefficient…

  1. Speech Disruptions in the Sentence Formulation of School-Age Children with Specific Language Impairment

    ERIC Educational Resources Information Center

    Finneran, Denise A.; Leonard, Laurence B.; Miller, Carol A.

    2009-01-01

    Background: Many school-age children with specific language impairment produce sentences that appear to conform to the adult grammar. It may be premature to conclude from this, however, that their language formulation ability is age appropriate. Aims: To determine whether a more subtle measure of language use, speech disruptions during sentence…

  2. The Age Specific Incidence Anomaly Suggests that Cancers Originate During Development

    NASA Astrophysics Data System (ADS)

    Brody, James P.

    2014-05-01

    The accumulation of genetic alterations causes cancers. Since this accumulation takes time, the incidence of most cancers is thought to increase exponentially with age. However, careful measurements of the age-specific incidence show that the specific incidence for many forms of cancer rises with age to a maximum, and then decreases. This decrease in the age-specific incidence with age is an anomaly. Understanding this anomaly should lead to a better understanding of how tumors develop and grow. Here we derive the shape of the age-specific incidence, showing that it should follow the shape of a Weibull distribution. Measurements indicate that the age-specific incidence for colon cancer does indeed follow a Weibull distribution. This analysis leads to the interpretation that for colon cancer two subpopulations exist in the general population: a susceptible population and an immune population. Colon tumors will only occur in the susceptible population. This analysis is consistent with the developmental origins of disease hypothesis and generalizable to many other common forms of cancer.

  3. The Age Specific Incidence Anomaly Suggests that Cancers Originate During Development

    NASA Astrophysics Data System (ADS)

    Brody, James P.

    The accumulation of genetic alterations causes cancers. Since this accumulation takes time, the incidence of most cancers is thought to increase exponentially with age. However, careful measurements of the age-specific incidence show that the specific incidence for many forms of cancer rises with age to a maximum, and then decreases. This decrease in the age-specific incidence with age is an anomaly. Understanding this anomaly should lead to a better understanding of how tumors develop and grow. Here we derive the shape of the age-specific incidence, showing that it should follow the shape of a Weibull distribution. Measurements indicate that the age-specific incidence for colon cancer does indeed follow a Weibull distribution. This analysis leads to the interpretation that for colon cancer two subpopulations exist in the general population: a susceptible population and an immune population. Colon tumors will only occur in the susceptible population. This analysis is consistent with the developmental origins of disease hypothesis and generalizable to many other common forms of cancer.

  4. Mass-Specific Metabolic Rate Influences Sperm Performance through Energy Production in Mammals.

    PubMed

    Tourmente, Maximiliano; Roldan, Eduardo R S

    2015-01-01

    Mass-specific metabolic rate, the rate at which organisms consume energy per gram of body weight, is negatively associated with body size in metazoans. As a consequence, small species have higher cellular metabolic rates and are able to process resources at a faster rate than large species. Since mass-specific metabolic rate has been shown to constrain evolution of sperm traits, and most of the metabolic activity of sperm cells relates to ATP production for sperm motility, we hypothesized that mass-specific metabolic rate could influence sperm energetic metabolism at the cellular level if sperm cells maintain the metabolic rate of organisms that generate them. We compared data on sperm straight-line velocity, mass-specific metabolic rate, and sperm ATP content from 40 mammalian species and found that the mass-specific metabolic rate positively influences sperm swimming velocity by (a) an indirect effect of sperm as the result of an increased sperm length, and (b) a direct effect independent of sperm length. In addition, our analyses show that species with higher mass-specific metabolic rate have higher ATP content per sperm and higher concentration of ATP per μm of sperm length, which are positively associated with sperm velocity. In conclusion, our results suggest that species with high mass-specific metabolic rate have been able to evolve both long and fast sperm. Moreover, independently of its effect on the production of larger sperm, the mass-specific metabolic rate is able to influence sperm velocity by increasing sperm ATP content in mammals.

  5. Parental age affects somatic mutation rates in the progeny of flowering plants.

    PubMed

    Singh, Amit Kumar; Bashir, Tufail; Sailer, Christian; Gurumoorthy, Viswanathan; Ramakrishnan, Anantha Maharasi; Dhanapal, Shanmuhapreya; Grossniklaus, Ueli; Baskar, Ramamurthy

    2015-05-01

    In humans, it is well known that the parental reproductive age has a strong influence on mutations transmitted to their progeny. Meiotic nondisjunction is known to increase in older mothers, and base substitutions tend to go up with paternal reproductive age. Hence, it is clear that the germinal mutation rates are a function of both maternal and paternal ages in humans. In contrast, it is unknown whether the parental reproductive age has an effect on somatic mutation rates in the progeny, because these are rare and difficult to detect. To address this question, we took advantage of the plant model system Arabidopsis (Arabidopsis thaliana), where mutation detector lines allow for an easy quantitation of somatic mutations, to test the effect of parental age on somatic mutation rates in the progeny. Although we found no significant effect of parental age on base substitutions, we found that frameshift mutations and transposition events increased in the progeny of older parents, an effect that is stronger through the maternal line. In contrast, intrachromosomal recombination events in the progeny decrease with the age of the parents in a parent-of-origin-dependent manner. Our results clearly show that parental reproductive age affects somatic mutation rates in the progeny and, thus, that some form of age-dependent information, which affects the frequency of double-strand breaks and possibly other processes involved in maintaining genome integrity, is transmitted through the gametes. PMID:25810093

  6. Age-related changes in auditory and visual interactions in temporal rate perception

    PubMed Central

    Brooks, Cassandra J.; Anderson, Andrew J.; Roach, Neil W.; McGraw, Paul V.; McKendrick, Allison M.

    2015-01-01

    We investigated how aging affects the integration of temporal rate for auditory flutter (amplitude modulation) presented with visual flicker. Since older adults were poorer at detecting auditory amplitude modulation, modulation depth was individually adjusted so that temporal rate was equally discriminable for 10 Hz flutter and flicker, thereby balancing the reliability of rate information available to each sensory modality. With age-related sensory differences normalized in this way, rate asynchrony skewed both auditory and visual rate judgments to the same extent in younger and older adults. Therefore, reliability-based weighting of temporal rate is preserved in older adults. Concurrent presentation of synchronous 10 Hz flicker and flutter improved temporal rate discrimination consistent with statistically optimal integration in younger but not older adults. In a control experiment, younger adults were presented with the same physical auditory stimulus as older adults. This time, rate asynchrony skewed perceived rate with greater auditory weighting rather than balanced integration. Taken together, our results indicate that integration of discrepant auditory and visual rates is not altered due to the healthy aging process once sensory deficits are accounted for, but that aging does abolish the minor improvement in discrimination performance seen in younger observers when concordant rates are integrated. PMID:26624937

  7. Age-specific fitness components and their temporal variation in the barn owl.

    PubMed

    Altwegg, Res; Schaub, Michael; Roulin, Alexandre

    2007-01-01

    Theory predicts that temporal variability plays an important role in the evolution of life histories, but empirical studies evaluating this prediction are rare. In constant environments, fitness can be measured by the population growth rate lambda, and the sensitivity of lambda to changes in fitness components estimates selection on these traits. In variable environments, fitness is measured by the stochastic growth rate lambda(S), and stochastic sensitivities estimate selection pressure. Here we examine age-specific schedules for reproduction and survival in a barn owl population (Tyto alba). We estimated how temporal variability affected fitness and selection, accounting for sampling variance. Despite large sample sizes of old individuals, we found no strong evidence for senescence. The most variable fitness components were associated with reproduction. Survival was less variable. Stochastic simulations showed that the observed variation decreased fitness by about 30%, but the sensitivities of lambda and lambda(S) to changes in all fitness components were almost equal, suggesting that temporal variation had negligible effects on selection. We obtained these results despite high observed variability in the fitness components and relatively short generation time of the study organism, a situation in which temporal variability should be particularly important for natural selection and early senescence is expected. PMID:17206584

  8. Estimation of age-specific per capita home-produced food intake among populations that garden, farm, or raise animals.

    PubMed

    Phillips, Linda; Moya, Jacqueline

    2012-01-01

    Intake of home-produced foods may be a concern in areas where chemical contamination exists. Estimating exposure to contaminants in home-produced foods requires knowledge of the amount of these foods consumed. The US Environmental Protection Agency's (US EPA's) Exposure Factors Handbook provides data on consumption of home-produced foods based on the US Department of Agriculture's (USDA's) 1987-1988 Nationwide Food Consumption Survey (NFCS), the most recent national food survey that contains the information necessary to estimate home-produced consumption. These data represent "consumer-only" intake rate distributions for various age and demographic categories. "Consumers-only" information is also provided for households who garden, farm, and raise animals for all age groups combined. However, these "consumer-only" values may not always be appropriate when assessing chronic exposures. Furthermore, data for all ages combined may not be useful for estimating exposure among age groups that may be of particular concern. This paper provides age-specific "per capita" intake rate distributions of home-produced foods specifically for the populations that garden, farm, and raise animals, using data from EPA's Exposure Factors Handbook. PMID:21522189

  9. Estimation of age-specific per capita home-produced food intake among populations that garden, farm, or raise animals.

    PubMed

    Phillips, Linda; Moya, Jacqueline

    2012-01-01

    Intake of home-produced foods may be a concern in areas where chemical contamination exists. Estimating exposure to contaminants in home-produced foods requires knowledge of the amount of these foods consumed. The US Environmental Protection Agency's (US EPA's) Exposure Factors Handbook provides data on consumption of home-produced foods based on the US Department of Agriculture's (USDA's) 1987-1988 Nationwide Food Consumption Survey (NFCS), the most recent national food survey that contains the information necessary to estimate home-produced consumption. These data represent "consumer-only" intake rate distributions for various age and demographic categories. "Consumers-only" information is also provided for households who garden, farm, and raise animals for all age groups combined. However, these "consumer-only" values may not always be appropriate when assessing chronic exposures. Furthermore, data for all ages combined may not be useful for estimating exposure among age groups that may be of particular concern. This paper provides age-specific "per capita" intake rate distributions of home-produced foods specifically for the populations that garden, farm, and raise animals, using data from EPA's Exposure Factors Handbook.

  10. Basis and implications of the CAP88 age-specific dose coefficients

    SciTech Connect

    Leggett, Richard Wayne; Scofield, Patricia A; Eckerman, Keith F

    2013-01-01

    Recent versions of CAP88 incorporate age-specific dose coefficients based on biokinetic and dosimetric models applied in Federal Guidance Report 13, Cancer Risk Coefficients for Environmental Exposure to Radionuclides (EPA 1999). With a few exceptions the models are those recommended in a series of reports by the International Commission on Radiological Protection (ICRP) on estimation of doses to the public from environmental radionuclides. This paper describes the basis for the ICRP s age-specific biokinetic and dosimetric models and examines differences with age in the derived dose coefficients and in estimates of dose per unit exposure based on those coefficients.

  11. Small impact craters in the lunar regolith - Their morphologies, relative ages, and rates of formation

    NASA Technical Reports Server (NTRS)

    Moore, H. J.; Boyce, J. M.; Hahn, D. A.

    1980-01-01

    The size frequency distributions, relative ages, and absolute age determination of lunar impact craters ranging in diameter from 1 to 100 m are discussed in relation to present-day and past impact rates. The size frequency distributions of craters produced by impacts on the lunar surface and of craters remaining after degradation with time and later impacts are examined, together with the steady state frequency curves for various crater morphologies. Relations between the relative ages of craters, their morphologies and their diameters are discussed, and the calibration of this kind of relationship with absolute crater ages by the location of individual craters with known absolute ages, diameters and frequency distribution statistics is considered. Estimates of present and past cratering rates based on crater size-frequency distributions are presented which suggest that the rate of impacting objects producing small lunar craters could have been constant over the last 100 million years.

  12. Age-related disappearance of Mayer-like heart rate waves

    NASA Technical Reports Server (NTRS)

    Jarisch, W. R.; Ferguson, J. J.; Shannon, R. P.; Wei, J. Y.; Goldberger, A. L.

    1987-01-01

    The effect of age on the principal spectral components of heart rate obtained immediately after passive upright tilt was investigated in human subjects who underwent a 60-deg tilt over 9 sec. Two groups were examined, the first of which consisting of healthy male subjects aged 22-26 years, while the second was comprised of subjects aged 65-84 years on no medication; radiograms were recorded continuously beginning just prior to tilt until 3 min posttilt. The results of spectral analysis showed that elderly subjects did not exhibit the Mayer-like heart rate waves (the 0.07-0.09 Hz oscillations) that were present in the spectra of young subjects immediately after passive upright tilt. The findings are consistent with the concept of a 'dysautonomia of aging'. It is suggested that postural stress testing with spectral analysis of heart rate fluctuations may provide a useful way of assessing physiologic vs chronologic age.

  13. Reliable ratings or reading tea leaves: can parent, teacher, and clinician behavioral ratings of preschoolers predict ADHD at age six?

    PubMed

    O'Neill, Sarah; Schneiderman, Robyn L; Rajendran, Khushmand; Marks, David J; Halperin, Jeffrey M

    2014-05-01

    To assess the relative ability of parent, teacher, and clinician behavioral ratings of preschoolers to predict ADHD severity and diagnosis at 6 years of age. Hyperactive/inattentive preschoolers [N = 104, 75 % boys, Mean (SD) age = 4.37 (0.47) years] were followed over 2 years (mean = 26.44 months, SD = 5.66). At baseline (BL), parents and teachers completed the ADHD-RS-IV and clinicians completed the Behavioral Rating Inventory for Children following a psychological testing session. At age 6, [Mean (SD) age = 6.62 (0.35) years], parents were interviewed with the K-SADS-PL; teachers completed the ADHD-RS-IV; and laboratory measures of hyperactivity, impulsivity, and inattention were obtained from children. Hierarchical logistic and linear regression analyses examined which combination of BL ratings best predicted 6-year-old ADHD diagnosis and severity, respectively. At age 6, 56 (53.8 %) children met DSM-IV criteria for a diagnosis of ADHD. BL ratings from parent/teacher/clinician, parent/teacher and parent/clinician combinations significantly predicted children who had an ADHD diagnosis at age 6. Parent and clinician, but not teacher, behavior ratings were significant independent predictors of ADHD diagnosis and severity at 6-years-old. However, only clinician reports of preschoolers' behaviors predicted laboratory measures of over-activity and inattention at follow-up. Cross-situationality is important for a diagnosis of ADHD during the preschool years. Among parents, teachers and clinicians, positive endorsements from all three informants, parent/teacher or parent/clinician appear to have prognostic value. Clinicians' ratings of preschoolers' inattention, impulsivity and hyperactivity are valid sources of information for predicting ADHD diagnosis and severity over time.

  14. Longitudinal Examination of Age-Predicted Symptom-Limited Exercise Maximum Heart Rate

    PubMed Central

    Zhu, Na; Suarez, Jose; Sidney, Steve; Sternfeld, Barbara; Schreiner, Pamela J.; Carnethon, Mercedes R.; Lewis, Cora E.; Crow, Richard S.; Bouchard, Claude; Haskell, William; Jacobs, David R.

    2010-01-01

    Purpose To estimate the association of age with maximal heart rate (MHR). Methods Data were obtained in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants were black and white men and women aged 18-30 in 1985-86 (year 0). A symptom-limited maximal graded exercise test was completed at years 0, 7, and 20 by 4969, 2583, and 2870 participants, respectively. After exclusion 9622 eligible tests remained. Results In all 9622 tests, estimated MHR (eMHR, beats/minute) had a quadratic relation to age in the age range 18 to 50 years, eMHR=179+0.29*age-0.011*age2. The age-MHR association was approximately linear in the restricted age ranges of consecutive tests. In 2215 people who completed both year 0 and 7 tests (age range 18 to 37), eMHR=189–0.35*age; and in 1574 people who completed both year 7 and 20 tests (age range 25 to 50), eMHR=199–0.63*age. In the lowest baseline BMI quartile, the rate of decline was 0.20 beats/minute/year between years 0-7 and 0.51 beats/minute/year between years 7-20; while in the highest baseline BMI quartile there was a linear rate of decline of approximately 0.7 beats/minute/year over the full age of 18 to 50 years. Conclusion Clinicians making exercise prescriptions should be aware that the loss of symptom-limited MHR is much slower at young adulthood and more pronounced in later adulthood. In particular, MHR loss is very slow in those with lowest BMI below age 40. PMID:20639723

  15. Increases in cognitive and linguistic processing primarily account for increases in speaking rate with age.

    PubMed

    Nip, Ignatius S B; Green, Jordan R

    2013-01-01

    Age-related increases of speaking rate are not fully understood, but have been attributed to gains in biologic factors and learned skills that support speech production. This study investigated developmental changes in speaking rate and articulatory kinematics of participants aged 4 (N = 7), 7 (N = 10), 10 (N = 9), 13 (N = 7), 16 (N = 9) years, and young adults (N = 11) in speaking tasks varying in task demands. Speaking rate increased with age, with decreases in pauses and articulator displacements but not increases in articulator movement speed. Movement speed did not appear to constrain the speaking. Rather, age-related increases in speaking rate are due to gains in cognitive and linguistic processing and speech motor control.

  16. 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.

  17. Age-related differences in valence and arousal ratings of pictures from the International Affective Picture System (IAPS): do ratings become more extreme with age?

    PubMed

    Grühn, Daniel; Scheibe, Susanne

    2008-05-01

    The International Affective Picture System (IAPS) has been widely used in aging-oriented research on emotion. However, no ratings for older adults are available. The aim of the present study was to close this gap by providing ratings of valence and arousal for 504 IAPS pictures by 53 young and 53 older adults. Both age groups rated positive pictures as less arousing, resulting in a stronger linear association between valence and arousal, than has been found in previous studies. This association was even stronger in older than in young adults. Older adults perceived negative pictures as more negative and more arousing and positive pictures as more positive and less arousing than young adults did. This might indicate a dedifferentiation of emotional processing in old age. On the basis of a picture recognition task, we also report memorability scores for individual pictures and how they relate to valence and arousal ratings. Data for all the pictures are archived at www.psychonomic.org/archive/.

  18. Variation in Prostate-Specific Antigen Screening in Men Aged 80 and Older in Fee-for-Service Medicare

    PubMed Central

    Bynum, Julie; Song, Yunjie; Fisher, Elliott

    2010-01-01

    OBJECTIVES To determine the rate of prostate-specific antigen (PSA) screening in men aged 80 and older in Medicare and to examine geographic variation in screening rates across the U.S. DESIGN Retrospective cohort study of variation across hospital referral regions using administrative data. SETTING National random sample in fee-for-service Medicare. PARTICIPANTS Medicare beneficiaries aged 80 and older in 2003. MEASUREMENTS Percentage of men aged 80 and older screened using the PSA test. RESULTS The national rate of PSA screening in men aged 80 and older was 17.2%, but there was wide variation across regions (<2–38%). Higher PSA screening in a region was positively associated with greater total costs (correlation coefficient (r) = 0.49, P<.001), greater intensive care unit use at the end of life (r = 0.46, P<.001), and greater number of unique physicians seen (r = 0.36, P<.001). PSA screening was negatively associated with proportion of beneficiaries using a primary care physician as opposed to a medical subspecialist for the predominance of ambulatory care (r = −0.38, P<.001). CONCLUSION PSA screening in men aged 80 and older is common practice, although its frequency is highly variable across the United States. Its association with fragmented physician care and aggressive end-of-life care may reflect less reliance on primary care and consequent difficulty informing patients of the potential harms and low likelihood of benefit of this procedure. PMID:20345867

  19. Differential Effect of Culture Temperature and Specific Growth Rate on CHO Cell Behavior in Chemostat Culture

    PubMed Central

    Vergara, Mauricio; Becerra, Silvana; Berrios, Julio; Osses, Nelson; Reyes, Juan; Rodríguez-Moyá, María; Gonzalez, Ramon; Altamirano, Claudia

    2014-01-01

    Mild hypothermia condition in mammalian cell culture technology has been one of the main focuses of research for the development of breeding strategies to maximize productivity of these production systems. Despite the large number of studies that show positive effects of mild hypothermia on specific productivity of r-proteins, no experimental approach has addressed the indirect effect of lower temperatures on specific cell growth rate, nor how this condition possibly affects less specific productivity of r-proteins. To separately analyze the effects of mild hypothermia and specific growth rate on CHO cell metabolism and recombinant human tissue plasminogen activator productivity as a model system, high dilution rate (0.017 h−1) and low dilution rate (0.012 h−1) at two cultivation temperatures (37 and 33°C) were evaluated using chemostat culture. The results showed a positive effect on the specific productivity of r-protein with decreasing specific growth rate at 33°C. Differential effect was achieved by mild hypothermia on the specific productivity of r-protein, contrary to the evidence reported in batch culture. Interestingly, reduction of metabolism could not be associated with a decrease in culture temperature, but rather with a decrease in specific growth rate. PMID:24699760

  20. Specific age-related molecular alterations in the cerebellum of Down syndrome mouse models.

    PubMed

    Créau, Nicole; Cabet, Eva; Daubigney, Fabrice; Souchet, Benoit; Bennaï, Soumia; Delabar, Jean

    2016-09-01

    Down syndrome, or trisomy 21, has been modeled with various trisomic and transgenic mice to help understand the consequences of an altered gene dosage in brain development and function. Though Down syndrome has been associated with premature aging, little is known about the molecular and cellular alterations that target brain function. To help identify alterations at specific ages, we analyzed the cerebellum of Ts1Cje mice, trisomic for 77 HSA21 orthologs, at three ages-young (4 months), middle-age (12 months), and old (17 months)-compared to age-matched controls. Quantification of neuronal and glial markers (n=11) revealed increases in GFAP, with an age effect, and S100B, with age and genotype effects. The genotype effect on S100B with age was unexpected as Ts1Cje has only two copies of the S100b gene. Interestingly, the different increase in GFAP observed between Ts1Cje (trisomic segment includes Pcp4 gene) and controls was magnified in TgPCP4 mice (1 extra copy of the human PCP4 gene) at the same age. S100B increase was not found in the TgPCP4 confirming a difference of regulation with aging for GFAP and S100B and excluding the calcium signaling regulator, Pcp4, as a potential candidate for increase of S100B in the Ts1Cje. To understand these differences, comparison of GFAP and S100B immunostainings at young and middle-age were performed. Immunohistochemical detection of differences in GFAP and S100B localization with aging implicate S100B+ oligodendrocytes as a new phenotypic target in this specific aging process. PMID:27297494

  1. Protein crystal growth rates are face-specifically modified by structurally related contaminants

    NASA Astrophysics Data System (ADS)

    Hirschler, Joachim; Fontecilla-Camps, Juan Carlos

    1997-02-01

    Growth rates of turkey egg-white lysozyme (TEWL) crystal faces have been measured in uncontaminated solutions as well as in solutions contaminated by the homologous hen egg-white lysozyme (HEWL). Comparison of growth rates from uncontaminated and contaminated solutions shows that the growth rate of the {112} faces drops significantly in the presence of the contaminant, whereas the growth rate of the {110} faces does not change. This demonstrates that HEWL acts specifically on the growth process of the {112} faces.

  2. Development of planning abilities in normal aging: differential effects of specific cognitive demands.

    PubMed

    Köstering, Lena; Stahl, Christoph; Leonhart, Rainer; Weiller, Cornelius; Kaller, Christoph P

    2014-01-01

    In line with the frontal hypothesis of aging, the ability to plan ahead undergoes substantial change during normal aging. Although impairments on the Tower of London planning task were reported earlier, associations between age-related declines and specific cognitive demands on planning have not been studied. Here we investigated the impact of search depth and goal ambiguity on planning, which impose demands on the depth and breadth of look-ahead processes, respectively. Besides an overall age-related decline in planning accuracy of 106 healthy older adults, differential search depth effects were found: Whereas planning accuracy of subjects in the early 60s was not affected by variations in search depth, between the ages of 65 and 76 years, accuracy was significantly decreased for high versus low levels of search depth. For subjects older than 76, different search depth levels did not further impact on accuracy, which was lowest overall. This nonlinear pattern may reflect differential impairments in fluid abilities and working memory capacity across various stages of older age. As no age-related effects of goal ambiguity were found, normal aging seems to be specifically sensitive to planning demands on the depth but not the breadth of anticipatory search processes. Hence, cognitive functions subserved by the prefrontal cortex experience differential development over the course of normal aging.

  3. Age, time, and cohort effects on functional status and self-rated health in elderly men.

    PubMed Central

    Hoeymans, N; Feskens, E J; van den Bos, G A; Kromhout, D

    1997-01-01

    OBJECTIVES: This study investigated age-related changes in functional status and self-rated health in elderly men, taking into account changes over time and differences between birth cohorts. METHODS: The Zutphen Elderly Study is a longitudinal study of men born in the Netherlands between 1900 and 1920. Functional status and self-rated health were measured in 513 men in 1990, in 381 men in 1993, and in 340 men in 1995. Age, time, and cohort effects were analyzed in a mixed longitudinal model. RESULTS: Longitudinal analyses showed that during 5 years of follow-up, the proportion of men without disabilities decreased from 53% to 39%, whereas the percentage who rated themselves as healthy decreased from 50% to 35%. Cross-sectional analyses confirmed changes in functional status, suggesting an age effect. Time-series analyses confirmed changes in self-rated health, suggesting a time effect. No birth-cohort effects were found. CONCLUSIONS: Functional status deteriorates with age, whereas self-rated health is not related to age in men aged 70 years and older. The observed 5-year decline in self-rated health seemed to be due to a secular trend. PMID:9357342

  4. The feasibility of developing a standards rating system for all Australian government aged care homes.

    PubMed

    Koch, Susan; Nay, Rhonda; McAuliffe, Linda; Koch, Bill

    2008-06-01

    Aims and objectives.  The main objective of this project was to investigate the likelihood of creating an easily understood rating system for all aged care homes. A secondary objective was to canvas the feasibility of alternative systems that could better inform aged care consumers. Background.  Standards rating systems are used internationally to enable comparisons in healthcare. In Australia, the performance of numerous services and products are measured according to the star system of ratings, yet despite their widespread use, star ratings remain absent from the healthcare industry. Methods.  A National Consultative Group (NCG) consisting of key stakeholder representatives was consulted, and a literature review performed on existing standards (or 'star') rating systems. Telephone interviews were conducted with representatives from aged care homes, as well as consumers. Results.  A standards rating system for aged care homes was not found to be feasible in the current climate. However, an alternative system that emphasises empowering aged care consumers, such as one that allows consumers to search for an aged care home using their own criteria of preference, was considered more feasible. Conclusion.  The need for information to assist consumer choice - limited as it may be - is real. Ways of providing more consumer friendly, useful information need to be further explored and developed. Recommendations are made for future work in this area.

  5. Reaction rate constants of H-abstraction by OH from large ketones: measurements and site-specific rate rules.

    PubMed

    Badra, Jihad; Elwardany, Ahmed E; Farooq, Aamir

    2014-06-28

    Reaction rate constants of the reaction of four large ketones with hydroxyl (OH) are investigated behind reflected shock waves using OH laser absorption. The studied ketones are isomers of hexanone and include 2-hexanone, 3-hexanone, 3-methyl-2-pentanone, and 4-methl-2-pentanone. Rate constants are measured under pseudo-first-order kinetics at temperatures ranging from 866 K to 1375 K and pressures near 1.5 atm. The reported high-temperature rate constant measurements are the first direct measurements for these ketones under combustion-relevant conditions. The effects of the position of the carbonyl group (C=O) and methyl (CH3) branching on the overall rate constant with OH are examined. Using previously published data, rate constant expressions covering, low-to-high temperatures, are developed for acetone, 2-butanone, 3-pentanone, and the hexanone isomers studied here. These Arrhenius expressions are used to devise rate rules for H-abstraction from various sites. Specifically, the current scheme is applied with good success to H-abstraction by OH from a series of n-ketones. Finally, general expressions for primary and secondary site-specific H-abstraction by OH from ketones are proposed as follows (the subscript numbers indicate the number of carbon atoms bonded to the next-nearest-neighbor carbon atom, the subscript CO indicates that the abstraction is from a site next to the carbonyl group (C=O), and the prime is used to differentiate different neighboring environments of a methylene group):

  6. Use of age-adjusted rates of suicide in time series studies in Israel.

    PubMed

    Bridges, F Stephen; Tankersley, William B

    2009-01-01

    Durkheim's modified theory of suicide was examined to explore how consistent it was in predicting Israeli rates of suicide from 1965 to 1997 when using age-adjusted rates rather than crude ones. In this time-series study, Israeli male and female rates of suicide increased and decreased, respectively, between 1965 and 1997. Conforming to Durkheim's modified theory, the Israeli male rate of suicide was lower in years when rates of marriage and birth are higher, while rates of suicide are higher in years when rates of divorce are higher, the opposite to that of Israeli women. The corrected regression coefficients suggest that the Israeli female rate of suicide remained lower in years when rate of divorce is higher, again the opposite suggested by Durkheim's modified theory. These results may indicate that divorce affects the mental health of Israeli women as suggested by their lower rate of suicide. Perhaps the "multiple roles held by Israeli females creates suicidogenic stress" and divorce provides some sense of stress relief, mentally speaking. The results were not as consistent with predictions suggested by Durkheim's modified theory of suicide as were rates from the United States for the same period nor were they consistent with rates based on "crude" suicide data. Thus, using age-adjusted rates of suicide had an influence on the prediction of the Israeli rate of suicide during this period.

  7. Metabolism and aging: effects of cold exposure on metabolic rate, body composition, and longevity in mice.

    PubMed

    Vaanholt, Lobke M; Daan, Serge; Schubert, Kristin A; Visser, G Henk

    2009-01-01

    The proposition that increased energy expenditure shortens life has a long history. The rate-of-living theory (Pearl 1928 ) states that life span and average mass-specific metabolic rate are inversely proportional. Originally based on interspecific allometric comparisons between species of mammals, the theory was later rejected on the basis of comparisons between taxa (e.g., birds have higher metabolic rates than mammals of the same size and yet live longer). It has rarely been experimentally tested within species. Here, we investigated the effects of increased energy expenditure, induced by cold exposure, on longevity in mice. Longevity was measured in groups of 60 male mice maintained at either 22 degrees C (WW) or 10 degrees C (CC) throughout adult life. Forty additional mice were maintained at both of these temperatures to determine metabolic rate (by stable isotope turnover, gas exchange, and food intake) as well as the mass of body and organs of subsets of animals at four different ages. Because energy expenditure might affect longevity by either accumulating damage or by instantaneously affecting mortality rate, we included a third group of mice exposed to 10 degrees C early in life and to 22 degrees C afterward (CW). Exposure to cold increased mean daily energy expenditure by ca. 48% (from 47.8 kJ d(-1) in WW to 70.6 kJ d(-1) in CC mice, with CW intermediate at 59.9 kJ d(-1)). However, we observed no significant differences in median life span among the groups (WW, 832 d; CC, 834 d; CW, 751 d). CC mice had reduced body mass (lifetime mean 30.7 g) compared with WW mice (33.8 g), and hence their lifetime energy potential (LEP) per gram whole-body mass had an even larger excess than per individual. Greenberg ( 1999 ) has pointed out that the size of the energetically costly organs, rather than that of the whole body, may be relevant for the rate-of-living idea. We therefore expressed LEP also in terms of energy expenditure per gram dry lean mass or per gram

  8. Effect of growth rate from 6 to 16 months of age on sexual development and reproductive function in beef bulls.

    PubMed

    Brito, L F C; Barth, A D; Wilde, R E; Kastelic, J P

    2012-04-15

    Sexual development and reproductive function were studied in 22 Angus × Charolais and 17 Angus bulls from 6 to 16 mo of age. Associations of average daily gain (ADG) and body weight with ages at puberty and at maturity (satisfactory semen quality), scrotal circumference, paired-testes volume and weight, testicular vascular cone diameter and fat thickness, scrotal temperature, sperm production and morphology, and testicular histology, were determined. There were no significant correlations between cumulative average daily gain and any of the end points investigated. Body weight at various ages was negatively correlated with ages at puberty and maturity in Angus × Charolais bulls, positively correlated with paired-testes weight in Angus × Charolais and Angus bulls, and positively correlated with seminiferous tubule volume in Angus bulls (P < 0.05). Semen quality improved gradually with age and the interval between puberty and maturity (mean ± SD; 309.4 ± 29.7 and 357 ± 42 days of age) was approximately 50 days. Age, weight, scrotal circumference, and paired-testes volume were all good predictors of pubertal and mature status, with moderate to high sensitivity and specificity (71.6% to 92.4%). In summary, growth rate between 6 and 16 mo of age did not affect sexual development and reproductive function in beef bulls. However, greater body weight at various ages was associated with reduced age at puberty and maturity, and with larger testes at 16 mo of age, indicating that improved nutrition might be beneficial, but only when offered before 6 mo of age. Average daily gains of approximately 1 to 1.6 kg/day did not result in excessive fat accumulation in the scrotum, increased scrotal temperature, or reduction in sperm production and semen quality, and could be considered "safe" targets for growing beef bulls.

  9. Mass-Specific Metabolic Rate and Sperm Competition Determine Sperm Size in Marsupial Mammals

    PubMed Central

    Tourmente, Maximiliano; Gomendio, Montserrat; Roldan, Eduardo R. S.

    2011-01-01

    Two complementary hypotheses have been proposed to explain variation in sperm size. The first proposes that post-copulatory sexual selection favors an increase in sperm size because it enhances sperm swimming speed, which is an important determinant of fertilization success in competitive contexts. The second hypothesis proposes that mass-specific metabolic rate acts as a constraint, because large animals with low mass-specific metabolic rates will not be able to process resources at the rates needed to produce large sperm. This constraint is expected to be particularly pronounced among mammals, given that this group contains some of the largest species on Earth. We tested these hypotheses among marsupials, a group in which mass-specific metabolic rates are roughly 30% lower than those of eutherian mammals of similar size, leading to the expectation that metabolic rate should be a major constraint. Our findings support both hypotheses because levels of sperm competition are associated with increases in sperm size, but low mass-specific metabolic rate constrains sperm size among large species. We also found that the relationship between sperm size and mass-specific metabolic rate is steeper among marsupials and shallower among eutherian mammals. This finding has two implications: marsupials respond to changes in mass-specific metabolic rate by modifying sperm length to a greater extent, suggesting that they are more constrained by metabolic rate. In addition, for any given mass-specific metabolic rate, marsupials produce longer sperm. We suggest that this is the consequence of marsupials diverting resources away from sperm numbers and into sperm size, due to their efficient sperm transport along the female tract and the existence of mechanisms to protect sperm. PMID:21731682

  10. Automated tissue classification of pediatric brains from magnetic resonance images using age-specific atlases

    NASA Astrophysics Data System (ADS)

    Metzger, Andrew; Benavides, Amanda; Nopoulos, Peg; Magnotta, Vincent

    2016-03-01

    The goal of this project was to develop two age appropriate atlases (neonatal and one year old) that account for the rapid growth and maturational changes that occur during early development. Tissue maps from this age group were initially created by manually correcting the resulting tissue maps after applying an expectation maximization (EM) algorithm and an adult atlas to pediatric subjects. The EM algorithm classified each voxel into one of ten possible tissue types including several subcortical structures. This was followed by a novel level set segmentation designed to improve differentiation between distal cortical gray matter and white matter. To minimize the req uired manual corrections, the adult atlas was registered to the pediatric scans using high -dimensional, symmetric image normalization (SyN) registration. The subject images were then mapped to an age specific atlas space, again using SyN registration, and the resulting transformation applied to the manually corrected tissue maps. The individual maps were averaged in the age specific atlas space and blurred to generate the age appropriate anatomical priors. The resulting anatomical priors were then used by the EM algorithm to re-segment the initial training set as well as an independent testing set. The results from the adult and age-specific anatomical priors were compared to the manually corrected results. The age appropriate atlas provided superior results as compared to the adult atlas. The image analysis pipeline used in this work was built using the open source software package BRAINSTools.

  11. Medical innovation and age-specific trends in health care utilization: findings and implications.

    PubMed

    Wong, Albert; Wouterse, Bram; Slobbe, Laurentius C J; Boshuizen, Hendriek C; Polder, Johan J

    2012-01-01

    Health care utilization is expected to rise in the coming decades. Not only will the aggregate need for health care grow by changing demographics, so too will per capita utilization. It has been suggested that trends in health care utilization may be age-specific. In this paper, age-specific trends in health care utilization are presented for different health care sectors in the Netherlands, for the period 1981-2009. For the hospital sector we also explore the link between these trends and the state of medical technology. Using aggregated data from a Dutch health survey and a nationwide hospital register, regression analysis was used to examine age-specific trends in the probability of utilizing health care. To determine the influence of medical technology, the growth in age-specific probabilities of hospital care was regressed on the number of medical patents while adjusting for confounders related to demographics, health status, supply and institutional factors. The findings suggest that for most health care sectors, the trend in the probability of health care utilization is highest for ages 65 and up. Larger advances in medical technology are found to be significantly associated with a higher growth of hospitalization probability, particularly for the higher ages. Age-specific trends will raise questions on the sustainability of intergenerational solidarity in health care, as solidarity will not only be strained by the ageing population, but also might find itself under additional pressure as the gap in health care utilization between elderly and non-elderly grows over time. For hospital care utilization, this process might well be accelerated by advances in medical technology.

  12. Regional specificity of sex effects on subcortical volumes across the lifespan in healthy aging.

    PubMed

    Li, Wenjing; van Tol, Marie-José; Li, Meng; Miao, Wen; Jiao, Yonghong; Heinze, Hans-Jochen; Bogerts, Bernhard; He, Huiguang; Walter, Martin

    2014-01-01

    When conceptualizing age-specific onsets and sex-specific characteristics of neuropsychiatric diseases in a neurobiological context, it may be crucially important to consider differential trajectories of aging. Here, we investigated effects of age, sex, and their interactions on absolute and relative volumes of subcortical structures with known involvement in psychiatric disorders, including the basal ganglia, thalamus, hippocampus, and amygdala. Structural MRI data of 76 healthy subjects (38 males, 19-70 years) from the ICBM database were analyzed. Age-related absolute atrophy was generally found in the basal ganglia and thalamus, while in the hippocampus decline was only observed in males, and was generally absent in the amygdala. Disproportionate degeneration in the basal ganglia and thalamus, exceeding cortical decline was specific for females. When allowing higher-order models, a quadratic model could better describe the negative relation of absolute volume and age in the basal ganglia in males, and generally in the hippocampus and amygdala. We could show that negative age-relations are highly specific for certain subcortical structures in either gender. Importantly these findings also emphasize the significant impact of analytical strategies when deciding for correction of subcortical volumes to the whole-brain decline. Specifically, in the basal ganglia disproportionate shrinkage in females was suggested by the relative analysis while absolute volume analysis rather stressed an accelerating decline in older males. Given strong involvement of the basal ganglia in both cognitive aging and emotional regulation, our findings may be crucial for studies investigating the onset and prevalence of dementia and depressive symptoms in male and female aging.

  13. Effects of age, signal level, and signal rate on the auditory middle latency response.

    PubMed

    Tucker, D A; Ruth, R A

    1996-04-01

    The effects of age, signal rate, and signal level on the maturing auditory middle latency response (AMLR) were evaluated in 50 normal-hearing subjects ranging in age from 2 days to 35 years. Ipsilateral and contralateral AMLR waveforms were recorded in newborns (n = 10), children (n = 10), preteens (n = 10), teens (n = 10), and adults (n = 10). The AMLR Pa waveform was obtained in 70 to 100 percent of all subjects. The variables of age, signal level, and site of recording significantly affected Pa peak amplitude and absolute latency. However, stimulus rate did not significantly affect the response.

  14. Effects of age, signal level, and signal rate on the auditory middle latency response.

    PubMed

    Tucker, D A; Ruth, R A

    1996-04-01

    The effects of age, signal rate, and signal level on the maturing auditory middle latency response (AMLR) were evaluated in 50 normal-hearing subjects ranging in age from 2 days to 35 years. Ipsilateral and contralateral AMLR waveforms were recorded in newborns (n = 10), children (n = 10), preteens (n = 10), teens (n = 10), and adults (n = 10). The AMLR Pa waveform was obtained in 70 to 100 percent of all subjects. The variables of age, signal level, and site of recording significantly affected Pa peak amplitude and absolute latency. However, stimulus rate did not significantly affect the response. PMID:8652873

  15. 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

  16. Crossing beef x beef and beef x Brown Swiss: pregnancy rate, calf survival, weaning age and rate.

    PubMed

    Reynolds, W L; Bellows, R A; Urick, J J; Knapp, B W

    1986-07-01

    October pregnancy rate, calf survival to weaning, weaning age, weaning rate and actual kg of calf weaned/cow exposed were determined in a 4-yr study involving 880 matings of Angus (A), Hereford (H) and Charolais (C) sires to A, H, C and Brown Swiss (BS) dams. Cows were mated in single-sire herds for 45 or 60 d under pasture conditions; heifers were bred to produce their first calf at 3 yr of age. Pregnancy rate of lactating dams was 9.4% higher (P less than .01) than for non-lactating dams. Pregnancy rates for straightbred matings were 87.5%, 80.6% and 75.4%, respectively, for A, H and C groups (P less than .05). No differences (P greater than .10) due to sire breed were found for any of the traits studied except for calf age at weaning. Calves from C sires were younger (P less than .01) at weaning than calves from H and A sires. Breed-of-dam differences (P less than .05 to P less than .01) were found for all traits studied except calf survival rate. All BS dams produced crossbred calves and had lower pregnancy and weaning rates (both P less than .01), calves were younger at weaning (P less than .05), had lower kg of calf weaned/cow exposed (P less than .05) than for beef-breed dams producing crossbred calves. Crossbred calves from BS dams were 4.9, 11.0 and 3.4 d younger (P less than .05 to P less than .01) at weaning, respectively, than crossbred calves from H, A and C dams.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Nature or nurture? Clues from the distribution of specific star formation rates in SDSS galaxies

    NASA Astrophysics Data System (ADS)

    Casado, J.; Ascasibar, Y.; Gavilán, M.; Terlevich, R.; Terlevich, E.; Hoyos, C.; Díaz, A. I.

    2015-07-01

    This work investigates the main mechanism(s) that regulate the specific star formation rate (SSFR) in nearby galaxies, cross-correlating two proxies of this quantity - the equivalent width of the Hα line and the (u - r) colour - with other physical properties (mass, metallicity, environment, morphology, and the presence of close companions) in a sample of ˜82 500 galaxies extracted from the Sloan Digital Sky Survey. The existence of a relatively tight `ageing sequence' in the colour-equivalent width plane favours a scenario where the secular conversion of gas into stars (i.e. nature) is the main physical driver of the instantaneous SSFR and the gradual transition from a `chemically primitive' (metal-poor and intensely star-forming) state to a `chemically evolved' (metal-rich and passively evolving) system. Nevertheless, environmental factors (i.e. nurture) are also important. In the field, galaxies may be temporarily affected by discrete `quenching' and `rejuvenation' episodes, but such events show little statistical significance in a probabilistic sense, and we find no evidence that galaxy interactions are, on average, a dominant driver of star formation. Although visually classified mergers tend to display systematically higher EW(Hα) and bluer (u - r) colours for a given luminosity, most galaxies with high SSFR have uncertain morphologies, which could be due to either internal or external processes. Field galaxies of early and late morphological types are consistent with the gradual `ageing' scenario, with no obvious signatures of a sudden decrease in their SSFR. In contrast, star formation is significantly reduced and sometimes completely quenched on a short time-scale in dense environments, where many objects are found on a `quenched sequence' in the colour-equivalent width plane.

  18. Is rate of skin wound healing associated with aging or longevity phenotype?

    PubMed

    Yanai, Hagai; Budovsky, Arie; Tacutu, Robi; Fraifeld, Vadim E

    2011-12-01

    Wound healing (WH) is a fundamental biological process. Is it associated with a longevity or aging phenotype? In an attempt to answer this question, we compared the established mouse models with genetically modified life span and also an altered rate of WH in the skin. Our analysis showed that the rate of skin WH in advanced ages (but not in the young animals) may be used as a marker for biological age, i.e., to be indicative of the longevity or aging phenotype. The ability to preserve the rate of skin WH up to an old age appears to be associated with a longevity phenotype, whereas a decline in WH-with an aging phenotype. In the young, this relationship is more complex and might even be inversed. While the aging process is likely to cause wounds to heal slowly, an altered WH rate in younger animals could indicate a different cellular proliferation and/or migration capacity, which is likely to affect other major processes such as the onset and progression of cancer. As a point for future studies on WH and longevity, using only young animals might yield confusing or misleading results, and therefore including older animals in the analysis is encouraged.

  19. Supervisor-subordinate age dissimilarity and performance ratings: the buffering effects of supervisory relationship and practice.

    PubMed

    Van der Heijden, Beatrice I J M; Scholarios, Dora; Van der Schoot, Esther; Jedrzejowicz, Piotr; Bozionelos, Nikos; Epitropaki, Olga; Knauth, Peter; Marzec, Izabela; Mikkelsen, Aslaug; Van der Heijde, Claudia

    2010-01-01

    Using 394 pairs of employees and their immediate supervisors working in the Information and Communication Technology (ICT) sector in three northern European countries, this study examined the effect of workplace moderators on the link between relational demography and supervisor ratings of performance. Directional age differences between superior and subordinate (i.e., status incongruence caused when the supervisor is older or younger than his/her subordinate) and non-directional age differences were used as predictors of supervisor ratings of occupational expertise. The quality of the supervisor-subordinate relationship and the existence of positive age-related supervisory practices were examined as moderators of this relationship. The results provide no support for a relationship between directional age differences and age-related stereotyping by supervisors in ratings of performance, neither for the effects of age-related supervisory practices. However, high quality supervisor-subordinate relationships did moderate the effects of age dissimilarity on supervisory ratings. The implications of these findings for performance appraisal methodologies and recommendations for further research are discussed. PMID:21174640

  20. 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."

  1. Cosmogenic Ne-21 Production Rates in H-Chondrites Based on Cl-36 - Ar-36 Ages

    NASA Technical Reports Server (NTRS)

    Leya, I.; Graf, Th.; Nishiizumi, K.; Guenther, D.; Wieler, R.

    2000-01-01

    We measured Ne-21 production rates in 14 H-chondrites in good agreement with model calculations. The production rates are based on Ne-21 concentrations measured on bulk samples or the non-magnetic fraction and Cl-36 - Ar-36 ages determined from the metal phase.

  2. Growth Kinetics and Morphology of Barite Crystals Derived from Face-Specific Growth Rates

    SciTech Connect

    Godinho, Jose R. A.; Stack, Andrew G.

    2015-03-30

    Here we investigate the growth kinetics and morphology of barite (BaSO4) crystals by measuring the growth rates of the (001), (210), (010), and (100) surfaces using vertical scanning interferometry. Solutions with saturation indices 1.1, 2.1, and 3.0 without additional electrolyte, in 0.7 M NaCl, or in 1.3 mM SrCl2 are investigated. Face-specific growth rates are inhibited in the SrCl2 solution relative to a solution without electrolyte, except for (100). Contrarily, growth of all faces is promoted in the NaCl solution. The variation of face-specific rates is solution-specific, which leads to a. change of the crystal morphology and overall growth rate of crystals. The measured face-specific growth rates are used to model the growth of single crystals. Modeled crystals have a morphology and size similar to those grown from solution. Based on the model the time dependence of surface area and growth rates is analyzed. Growth rates change with time due to surface area normalization for small crystals and large growth intervals. By extrapolating rates to crystals with large surfaces areas, time-independent growth rates are 0.783, 2.96, and 0.513 mmol∙m-2∙h-1, for saturation index 2.1 solutions without additional electrolyte, NaCl, and SrCl2, respectively.

  3. Effects of age, dysphoria, and emotion-focusing on autobiographical memory specificity in children.

    PubMed

    O'Carroll, Ronan E; Dalgleish, Tim; Drummond, Lyndsey E; Dritschel, Barbara; Astell, Arlene

    2006-04-01

    Overgeneral autobiographical memory (OGM) is strongly associated with depression in adults and appears to reflect a stable cognitive bias. However, it is not known whether this bias exists in children or what factors contribute to its development. We examined the roles of age, dysphoria, and a new variable, emotion-focusing (EF), on the production of specific autobiographical memory (AM) in children, using the standard Autobiographical Memory Test (AMT; Williams & Broadbent, 1986 ). Results show that older children are more specific than younger children, irrespective of cue valence. Dysphoria was linked to less specific retrieval of positive memories in children. A three-way interaction between age, valence, and dysphoria was also found, such that older dysphoric children demonstrated a difficulty in retrieving specific negative memories. In addition, emotion-focusing was associated with specific AM recall, especially to negative cues. Results are discussed with reference to the development of depressogenic biases. PMID:26529217

  4. Effects of age, dysphoria, and emotion-focusing on autobiographical memory specificity in children.

    PubMed

    O'Carroll, Ronan E; Dalgleish, Tim; Drummond, Lyndsey E; Dritschel, Barbara; Astell, Arlene

    2006-04-01

    Overgeneral autobiographical memory (OGM) is strongly associated with depression in adults and appears to reflect a stable cognitive bias. However, it is not known whether this bias exists in children or what factors contribute to its development. We examined the roles of age, dysphoria, and a new variable, emotion-focusing (EF), on the production of specific autobiographical memory (AM) in children, using the standard Autobiographical Memory Test (AMT; Williams & Broadbent, 1986 ). Results show that older children are more specific than younger children, irrespective of cue valence. Dysphoria was linked to less specific retrieval of positive memories in children. A three-way interaction between age, valence, and dysphoria was also found, such that older dysphoric children demonstrated a difficulty in retrieving specific negative memories. In addition, emotion-focusing was associated with specific AM recall, especially to negative cues. Results are discussed with reference to the development of depressogenic biases.

  5. The Characterization of Varicella Zoster Virus Specific T Cells In Skin and Blood During Ageing

    PubMed Central

    Vukmanovic-Stejic, Milica; Sandhu, Daisy; Seidel, Judith A.; Patel, Neil; Sobande, Toni O.; Agius, Elaine; Jackson, Sarah E.; Fuentes-Duculan, Judilyn; Suarez-Farinas, Mayte; Mabbott, Neil A.; Lacy, Katie E.; Ogg, Graham; Nestle, Frank O; Krueger, James G.; Rustin, Malcolm H.A.; Akbar, Arne N.

    2015-01-01

    The varicella-zoster virus (VZV) re-activation increases during ageing. Although the effects of VZV re-activation are observed in the skin (shingles) the number or functional capacity of cutaneous VZV specific T cells have not been investigated. The numbers of circulating IFN-γ secreting VZV specific CD4+ T cells are significantly decreased in old subjects however other measures of VZV-specific CD4+ T cells, including proliferative capacity to VZV antigen stimulation and identification of VZV-specific CD4+ T cells with a MHC class II tetramer (epitope of IE-63 protein), were similar in both age groups. The majority of T cells in the skin of both age groups expressed CD69, a characteristic of skin resident T cells. VZV-specific CD4+ T cells were significantly increased in the skin compared to the blood in young and old subjects and their function was similar in both age groups. In contrast the number of Foxp3+ regulatory T cells (Tregs) and expression of the inhibitory receptor PD-1 on CD4+ T cells were significantly increased in the skin of older humans. Therefore VZV-specific CD4+ T cells in the skin of older individuals are functionally competent. However their activity may be restricted by multiple inhibitory influences in situ. PMID:25734814

  6. Disposal rate in different age groups of Karan Fries (Crossbred) males in organized herd

    PubMed Central

    Panmei, Achun; Gupta, A. K.; Shivahre, P. R.; Bhakat, M.; Singh, K. Mahesh

    2015-01-01

    Aim: The present study was carried out to analyze the disposal rate in different age groups of Karan Fries (KF) males in National Dairy Research Institute herd. Materials and Methods: Records on 1740 KF crossbred bulls born during the period 1997-2012 were collected with an objective to ascertain the effect of genetic and non-genetic (Period of birth and season of birth) factors on the disposal pattern of KF males. The percent of animals disposed from the herd due to mortality and culling was calculated by proportion using descriptive statistics. The data were subjected to Chi-square test to test the difference due to different factors. Results: Overall disposal rate for the different age groups of 0-1 m, 1-2 m, 2-3 m, 3-6 m, 6-18 m, 18 m-3 year and 3-5 year were calculated as 17.9, 16.3, 14.2, 25.8, 49.0, 37.6 and 51.65%, respectively. In the age groups, 3-6 m, 6-18 m and 3-5 year, effect of periods of birth were found to be statistically significant (p<0.01) for overall disposal rate. Across different seasons of birth, overall disposal rates differed significantly (p<0.01) in different age group except in 3-5 year age group. Differences in overall disposal rate due to genetic group were statistically significant (p<0.01) in 1-2 m, 2-3 m, 3-6 m, 6-18 m, 18-3 year and 3-5 year age groups. Conclusion: Overview of the results indicated that higher overall disposal rate in age group of 1 month was due to mortality while, in the age groups of >1 month, culling was the primary cause. PMID:27047071

  7. Age at marriage as a factor in state divorce rate differentials.

    PubMed

    Weed, J A

    1974-08-01

    The prominent East-to-West gradient in state divorce rates has frequently been partially attributed to an ecological factor called "frontier atmosphere," which incorporates the effects of mobility on social integration. This paper employs linear statistical procedures to show that, after adjustment of state divorce rates for age distribution, the percent ever married among teenage females is the best statistical predictor of 1960 and 1970 divorce rates, whereas "frontierness," conventionally measured by population mobility, is shown to have negligible effect, controlling for other selected legal and nonlegal factors. This finding suggests that previous ecological studies of divorce have overemphasized the effect of mobility and social stability on geographic divorce rate differentials, perhaps due to the neglect of demographic variables such as age distribution and especially age at marriage.

  8. The role of age-specific learning and experience for turtles navigating a changing landscape.

    PubMed

    Roth, Timothy C; Krochmal, Aaron R

    2015-02-01

    The severity of the environment often influences animal cognition [1-6], as does the rate of change within that environment [7-10]. Rapid alteration of habitat places limitations on basic resources such as energy, water, nesting sites, and refugia [8, 10]. How animals respond to these situations provides insight into the mechanisms of cognition and the role of behavior in adaptation [11-13]. We tested the hypothesis that learning plays a role in the navigation of the painted turtle (Chrysemys picta) within a model of environmental change. We radiotracked experienced and naive turtles at different developmental stages from two different populations as they sought out new habitats when their pond was destroyed. Our data suggest that the ability of turtles to navigate is facilitated in part by experience during a critical period. Resident adults repeatedly used specific routes with exceptional precision, while translocated adults failed to find water. Naive juveniles (1-3 years old) from both populations used the same paths taken by resident adults; the ability to follow paths was lost by age 4. We also used laboratory behavioral assays to examine the possible cues facilitating this precise navigation. Turtles responded to manipulation of the local ultraviolet environment, but not the olfactory environment. This is the first evidence to suggest that learning during a critical period may be important for how animals respond to changing environments. Our work emphasizes the need for the examination of learning in navigation and the breadth of critical learning periods across vertebrates. PMID:25578905

  9. 42 CFR 412.332 - Payment based on the hospital-specific rate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Payment based on the hospital-specific rate. 412... HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates...

  10. Growth Kinetics and Morphology of Barite Crystals Derived from Face-Specific Growth Rates

    DOE PAGES

    Godinho, Jose R. A.; Stack, Andrew G.

    2015-03-30

    Here we investigate the growth kinetics and morphology of barite (BaSO4) crystals by measuring the growth rates of the (001), (210), (010), and (100) surfaces using vertical scanning interferometry. Solutions with saturation indices 1.1, 2.1, and 3.0 without additional electrolyte, in 0.7 M NaCl, or in 1.3 mM SrCl2 are investigated. Face-specific growth rates are inhibited in the SrCl2 solution relative to a solution without electrolyte, except for (100). Contrarily, growth of all faces is promoted in the NaCl solution. The variation of face-specific rates is solution-specific, which leads to a. change of the crystal morphology and overall growth ratemore » of crystals. The measured face-specific growth rates are used to model the growth of single crystals. Modeled crystals have a morphology and size similar to those grown from solution. Based on the model the time dependence of surface area and growth rates is analyzed. Growth rates change with time due to surface area normalization for small crystals and large growth intervals. By extrapolating rates to crystals with large surfaces areas, time-independent growth rates are 0.783, 2.96, and 0.513 mmol∙m-2∙h-1, for saturation index 2.1 solutions without additional electrolyte, NaCl, and SrCl2, respectively.« less

  11. Can Sample-Specific Simulations Help Detect Low Base-Rate Taxonicity?

    ERIC Educational Resources Information Center

    Beach, Steven R. H.; Amir, Nader; Bau, Jinn Jonp

    2005-01-01

    The authors examined the role of the sample-specific simulations (SSS; A. M. Ruscio & J. Ruscio, 2002; J. Ruscio & A. M. Ruscio, 2004) procedure in detecting low base-rate taxa that might otherwise prove elusive. The procedure preserved key distributional characteristics for moderate to high base-rate taxa, but it performed inadequately for low…

  12. 42 CFR 412.332 - Payment based on the hospital-specific rate.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.332 Payment based on the hospital-specific rate. The payment amount for...

  13. 42 CFR 412.328 - Determining and updating the hospital-specific rate.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... AND HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.328 Determining and updating the hospital-specific rate. (a)...

  14. 42 CFR 412.332 - Payment based on the hospital-specific rate.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.332 Payment based on the hospital-specific rate. The payment amount for...

  15. 42 CFR 412.328 - Determining and updating the hospital-specific rate.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... AND HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.328 Determining and updating the hospital-specific rate. (a)...

  16. 42 CFR 412.328 - Determining and updating the hospital-specific rate.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... AND HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.328 Determining and updating the hospital-specific rate. (a)...

  17. 42 CFR 412.328 - Determining and updating the hospital-specific rate.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AND HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.328 Determining and updating the hospital-specific rate. (a)...

  18. 42 CFR 412.332 - Payment based on the hospital-specific rate.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.332 Payment based on the hospital-specific rate. The payment amount for...

  19. 42 CFR 412.332 - Payment based on the hospital-specific rate.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period Payment Rates for Capital-Related Costs § 412.332 Payment based on the hospital-specific rate. The payment amount for...

  20. Age at first reproduction explains rate variation in the strepsirrhine molecular clock

    PubMed Central

    Tsantes, C.; Steiper, M. E.

    2009-01-01

    Although the molecular clock hypothesis posits that the rate of molecular change is constant over time, there is evidence that rates vary among lineages. Some of the strongest evidence for variable molecular rates comes from the primates; e.g., the “hominoid slowdown.” These rate differences are hypothesized to correlate with certain species attributes, such as generation time and body size. Here, we examine rates of molecular change in the strepsirrhine suborder of primates and test whether body size or age at first reproduction (a proxy for generation time) explains patterns of rate variation better than a null model where the molecular clock is independent of these factors. To examine these models, we analyzed DNA sequences from four pairs of recently diverged strepsirrhine sister taxa to estimate molecular rates by using sign tests, likelihood ratio tests, and regression analyses. Our analysis does not support a model where body weight or age at first reproduction strongly influences rates of molecular evolution across mitochondrial and nuclear sites. Instead, our analysis supports a model where age at first reproduction influences neutral evolution in the nuclear genome. This study supports the generation time hypothesis for rate variation in the nuclear molecular clock. Molecular clock variation due to generation time may help to resolve the discordance between molecular and paleontological estimates for divergence date estimates in primate evolution. PMID:19841267

  1. The contributions of age and sex to variation in common tern population growth rate.

    PubMed

    Ezard, T H G; Becker, P H; Coulson, T

    2006-11-01

    1. The decomposition of population growth rate into contributions from different demographic rates has many applications, ranging from evolutionary biology to conservation and management. Demographic rates with low variance may be pivotal for population persistence, but variable rates can have a dramatic influence on population growth rate. 2. In this study, the mean and variance in population growth rate (lambda) is decomposed into contributions from different ages and demographic rates using prospective and retrospective matrix analyses for male and female components of an increasing common tern (Sterna hirundo) population. 3. Three main results emerged: (1) subadult return was highly influential in prospective and retrospective analyses; (2) different age-classes made different contributions to variation in lambda: older age classes consistently produced offspring whereas young adults performed well only in high quality years; and (3) demographic rate covariation explained a significant proportion of variation in both sexes. A large contribution to lambda did not imply a large contribution to its variation. 4. This decomposition strengthens the argument that the relationship between variation in demographic rates and variation in lambda is complex. Understanding this relationship and its consequences for population persistence and evolutionary change demands closer examination of the lives, and deaths, of the individuals within populations within species.

  2. Age at first reproduction explains rate variation in the strepsirrhine molecular clock.

    PubMed

    Tsantes, C; Steiper, M E

    2009-10-27

    Although the molecular clock hypothesis posits that the rate of molecular change is constant over time, there is evidence that rates vary among lineages. Some of the strongest evidence for variable molecular rates comes from the primates; e.g., the "hominoid slowdown." These rate differences are hypothesized to correlate with certain species attributes, such as generation time and body size. Here, we examine rates of molecular change in the strepsirrhine suborder of primates and test whether body size or age at first reproduction (a proxy for generation time) explains patterns of rate variation better than a null model where the molecular clock is independent of these factors. To examine these models, we analyzed DNA sequences from four pairs of recently diverged strepsirrhine sister taxa to estimate molecular rates by using sign tests, likelihood ratio tests, and regression analyses. Our analysis does not support a model where body weight or age at first reproduction strongly influences rates of molecular evolution across mitochondrial and nuclear sites. Instead, our analysis supports a model where age at first reproduction influences neutral evolution in the nuclear genome. This study supports the generation time hypothesis for rate variation in the nuclear molecular clock. Molecular clock variation due to generation time may help to resolve the discordance between molecular and paleontological estimates for divergence date estimates in primate evolution.

  3. Age-Specific Variation in Immune Response in Drosophila melanogaster Has a Genetic Basis

    PubMed Central

    Felix, Tashauna M.; Hughes, Kimberly A.; Stone, Eric A.; Drnevich, Jenny M.; Leips, Jeff

    2012-01-01

    Immunosenescence, the age-related decline in immune system function, is a general hallmark of aging. While much is known about the cellular and physiological changes that accompany immunosenescence, we know little about the genetic influences on this phenomenon. In this study we combined age-specific measurements of bacterial clearance ability following infection with whole-genome measurements of the transcriptional response to infection and wounding to identify genes that contribute to the natural variation in immunosenescence, using Drosophila melanogaster as a model system. Twenty inbred lines derived from nature were measured for their ability to clear an Escherichia coli infection at 1 and 4 weeks of age. We used microarrays to simultaneously determine genome-wide expression profiles in infected and wounded flies at each age for 12 of these lines. Lines exhibited significant genetically based variation in bacterial clearance at both ages; however, the genetic basis of this variation changed dramatically with age. Variation in gene expression was significantly correlated with bacterial clearance ability only in the older age group. At 4 weeks of age variation in the expression of 247 genes following infection was associated with genetic variation in bacterial clearance. Functional annotation analyses implicate genes involved in energy metabolism including those in the insulin signaling/TOR pathway as having significant associations with bacterial clearance in older individuals. Given the evolutionary conservation of the genes involved in energy metabolism, our results could have important implications for understanding immunosenescence in other organisms, including humans. PMID:22554890

  4. Contrasted patterns of age-specific reproduction in long-lived seabirds.

    PubMed

    Berman, M; Gaillard, J-M; Weimerskirch, H

    2009-01-22

    While the number of studies providing evidence of actuarial senescence is increasing, and covers a wide range of taxa, the process of reproductive senescence remains poorly understood. In fact, quite high reproductive output until the last years of life has been reported in several vertebrate species, so that whether or not reproductive senescence is widespread remains unknown. We compared age-specific changes of reproductive parameters between two closely related species of long-lived seabirds: the small-sized snow petrel Pagodroma nivea, and the medium-sized southern fulmar Fulmarus glacialoides. Both are sympatric in Antarctica. We used an exceptional dataset collected over more than 40 years to assess age-specific variations of both breeding probability and breeding success. We found contrasted age-specific reproductive patterns between the two species. Reproductive senescence clearly occurred from 21 years of age onwards in the southern fulmar, in both breeding probability and success, whereas we did not report any decline in the breeding success of the snow petrel, although a very late decrease in the proportion of breeders occurred at 34 years. Such a contrasted age-specific reproductive pattern was rather unexpected. Differences in life history including size or migratory behaviour are the most likely candidates to account for the difference we reported in reproductive senescence between these sympatric seabird species. PMID:18832060

  5. Senescence and age-specific trade-offs between reproduction and survival in female Asian elephants.

    PubMed

    Robinson, Matthew R; Mar, Khyne U; Lummaa, Virpi

    2012-03-01

    Although studies on laboratory species and natural populations of vertebrates have shown reproduction to impair later performance, little is known of the age-specific associations between reproduction and survival, and how such findings apply to the ageing of large, long-lived species. Herein we develop a framework to examine population-level patterns of reproduction and survival across lifespan in long-lived organisms, and decompose those changes into individual-level effects, and the effects of age-specific trade-offs between fitness components. We apply this to an extensive longitudinal dataset on female semi-captive Asian timber elephants (Elephas maximus) and report the first evidence of age-specific fitness declines that are driven by age-specific associations between fitness components in a long-lived mammal. Associations between reproduction and survival are positive in early life, but negative in later life with up to 71% of later-life survival declines associated with investing in the production of offspring within this population of this critically endangered species.

  6. [The age-specific features of palm dermatoglyphics in the adults subjects].

    PubMed

    Teplov, K V; Bozhchenko, A P; Tolmachev, I A; Moiseenko, S A

    2016-01-01

    This article was designed to consider the congenital age-specific features of palm dermatoglyphics in the adults subjects (including the type of the papillary patterns, axial tri-radii, the termini of palmar main lines, the rudiments of palmar lines, the dermatoglyphic ridge count between the stable anatomical structures). The objective of the study was to look for the new diagnostic markers of the biological age. It included the identification of the palm prints obtained from 180 Caucasoid men and 120 women at the age varying from 16 to 80 years. The results of the mathematical and statistical analysis provided the basis for drawing up the list of 18 attributes of palm dermatoglyphics significantly (p<0.05) differing in the frequency of occurrence between the representatives of individual age groups. The methods are proposed allowing to use these findings for the expert evaluation of the age of unknown subjects.

  7. Realistic Hot Water Draw Specification for Rating Solar Water Heaters: Preprint

    SciTech Connect

    Burch, J.

    2012-06-01

    In the United States, annual performance ratings for solar water heaters are simulated, using TMY weather and specified water draw. A more-realistic ratings draw is proposed that eliminates most bias by improving mains inlet temperature and by specifying realistic hot water use. This paper outlines the current and the proposed draws and estimates typical ratings changes from draw specification changes for typical systems in four cities.

  8. Tissue-Specific Suppression of Thyroid Hormone Signaling in Various Mouse Models of Aging.

    PubMed

    Visser, W Edward; Bombardieri, Cíntia R; Zevenbergen, Chantal; Barnhoorn, Sander; Ottaviani, Alexandre; van der Pluijm, Ingrid; Brandt, Renata; Kaptein, Ellen; van Heerebeek, Ramona; van Toor, Hans; Garinis, George A; Peeters, Robin P; Medici, Marco; van Ham, Willy; Vermeij, Wilbert P; de Waard, Monique C; de Krijger, Ronald R; Boelen, Anita; Kwakkel, Joan; Kopchick, John J; List, Edward O; Melis, Joost P M; Darras, Veerle M; Dollé, Martijn E T; van der Horst, Gijsbertus T J; Hoeijmakers, Jan H J; Visser, Theo J

    2016-01-01

    DNA damage contributes to the process of aging, as underscored by premature aging syndromes caused by defective DNA repair. Thyroid state changes during aging, but underlying mechanisms remain elusive. Since thyroid hormone (TH) is a key regulator of metabolism, changes in TH signaling have widespread effects. Here, we reveal a significant common transcriptomic signature in livers from hypothyroid mice, DNA repair-deficient mice with severe (Csbm/m/Xpa-/-) or intermediate (Ercc1-/Δ-7) progeria and naturally aged mice. A strong induction of TH-inactivating deiodinase D3 and decrease of TH-activating D1 activities are observed in Csbm/m/Xpa-/- livers. Similar findings are noticed in Ercc1-/Δ-7, in naturally aged animals and in wild-type mice exposed to a chronic subtoxic dose of DNA-damaging agents. In contrast, TH signaling in muscle, heart and brain appears unaltered. These data show a strong suppression of TH signaling in specific peripheral organs in premature and normal aging, probably lowering metabolism, while other tissues appear to preserve metabolism. D3-mediated TH inactivation is unexpected, given its expression mainly in fetal tissues. Our studies highlight the importance of DNA damage as the underlying mechanism of changes in thyroid state. Tissue-specific regulation of deiodinase activities, ensuring diminished TH signaling, may contribute importantly to the protective metabolic response in aging. PMID:26953569

  9. Tissue-Specific Suppression of Thyroid Hormone Signaling in Various Mouse Models of Aging.

    PubMed

    Visser, W Edward; Bombardieri, Cíntia R; Zevenbergen, Chantal; Barnhoorn, Sander; Ottaviani, Alexandre; van der Pluijm, Ingrid; Brandt, Renata; Kaptein, Ellen; van Heerebeek, Ramona; van Toor, Hans; Garinis, George A; Peeters, Robin P; Medici, Marco; van Ham, Willy; Vermeij, Wilbert P; de Waard, Monique C; de Krijger, Ronald R; Boelen, Anita; Kwakkel, Joan; Kopchick, John J; List, Edward O; Melis, Joost P M; Darras, Veerle M; Dollé, Martijn E T; van der Horst, Gijsbertus T J; Hoeijmakers, Jan H J; Visser, Theo J

    2016-01-01

    DNA damage contributes to the process of aging, as underscored by premature aging syndromes caused by defective DNA repair. Thyroid state changes during aging, but underlying mechanisms remain elusive. Since thyroid hormone (TH) is a key regulator of metabolism, changes in TH signaling have widespread effects. Here, we reveal a significant common transcriptomic signature in livers from hypothyroid mice, DNA repair-deficient mice with severe (Csbm/m/Xpa-/-) or intermediate (Ercc1-/Δ-7) progeria and naturally aged mice. A strong induction of TH-inactivating deiodinase D3 and decrease of TH-activating D1 activities are observed in Csbm/m/Xpa-/- livers. Similar findings are noticed in Ercc1-/Δ-7, in naturally aged animals and in wild-type mice exposed to a chronic subtoxic dose of DNA-damaging agents. In contrast, TH signaling in muscle, heart and brain appears unaltered. These data show a strong suppression of TH signaling in specific peripheral organs in premature and normal aging, probably lowering metabolism, while other tissues appear to preserve metabolism. D3-mediated TH inactivation is unexpected, given its expression mainly in fetal tissues. Our studies highlight the importance of DNA damage as the underlying mechanism of changes in thyroid state. Tissue-specific regulation of deiodinase activities, ensuring diminished TH signaling, may contribute importantly to the protective metabolic response in aging.

  10. Tissue-Specific Suppression of Thyroid Hormone Signaling in Various Mouse Models of Aging

    PubMed Central

    Visser, W. Edward; Barnhoorn, Sander; Ottaviani, Alexandre; van der Pluijm, Ingrid; Brandt, Renata; Kaptein, Ellen; van Heerebeek, Ramona; van Toor, Hans; Garinis, George A.; Peeters, Robin P.; Medici, Marco; van Ham, Willy; Vermeij, Wilbert P.; de Waard, Monique C.; de Krijger, Ronald R.; Boelen, Anita; Kwakkel, Joan; Kopchick, John J.; List, Edward O.; Melis, Joost P. M.; Darras, Veerle M.; Dollé, Martijn E. T.; van der Horst, Gijsbertus T. J.; Hoeijmakers, Jan H. J.; Visser, Theo J.

    2016-01-01

    DNA damage contributes to the process of aging, as underscored by premature aging syndromes caused by defective DNA repair. Thyroid state changes during aging, but underlying mechanisms remain elusive. Since thyroid hormone (TH) is a key regulator of metabolism, changes in TH signaling have widespread effects. Here, we reveal a significant common transcriptomic signature in livers from hypothyroid mice, DNA repair-deficient mice with severe (Csbm/m/Xpa-/-) or intermediate (Ercc1-/Δ-7) progeria and naturally aged mice. A strong induction of TH-inactivating deiodinase D3 and decrease of TH-activating D1 activities are observed in Csbm/m/Xpa-/- livers. Similar findings are noticed in Ercc1-/Δ-7, in naturally aged animals and in wild-type mice exposed to a chronic subtoxic dose of DNA-damaging agents. In contrast, TH signaling in muscle, heart and brain appears unaltered. These data show a strong suppression of TH signaling in specific peripheral organs in premature and normal aging, probably lowering metabolism, while other tissues appear to preserve metabolism. D3-mediated TH inactivation is unexpected, given its expression mainly in fetal tissues. Our studies highlight the importance of DNA damage as the underlying mechanism of changes in thyroid state. Tissue-specific regulation of deiodinase activities, ensuring diminished TH signaling, may contribute importantly to the protective metabolic response in aging. PMID:26953569

  11. Metabolomic profiling reveals severe skeletal muscle group-specific perturbations of metabolism in aged FBN rats.

    PubMed

    Garvey, Sean M; Dugle, Janis E; Kennedy, Adam D; McDunn, Jonathan E; Kline, William; Guo, Lining; Guttridge, Denis C; Pereira, Suzette L; Edens, Neile K

    2014-06-01

    Mammalian skeletal muscles exhibit age-related adaptive and pathological remodeling. Several muscles in particular undergo progressive atrophy and degeneration beyond median lifespan. To better understand myocellular responses to aging, we used semi-quantitative global metabolomic profiling to characterize trends in metabolic changes between 15-month-old adult and 32-month-old aged Fischer 344 × Brown Norway (FBN) male rats. The FBN rat gastrocnemius muscle exhibits age-dependent atrophy, whereas the soleus muscle, up until 32 months, exhibits markedly fewer signs of atrophy. Both gastrocnemius and soleus muscles were analyzed, as well as plasma and urine. Compared to adult gastrocnemius, aged gastrocnemius showed evidence of reduced glycolytic metabolism, including accumulation of glycolytic, glycogenolytic, and pentose phosphate pathway intermediates. Pyruvate was elevated with age, yet levels of citrate and nicotinamide adenine dinucleotide were reduced, consistent with mitochondrial abnormalities. Indicative of muscle atrophy, 3-methylhistidine and free amino acids were elevated in aged gastrocnemius. The monounsaturated fatty acids oleate, cis-vaccenate, and palmitoleate also increased in aged gastrocnemius, suggesting altered lipid metabolism. Compared to gastrocnemius, aged soleus exhibited far fewer changes in carbohydrate metabolism, but did show reductions in several glycolytic intermediates, fumarate, malate, and flavin adenine dinucleotide. Plasma biochemicals showing the largest age-related increases included glycocholate, heme, 1,5-anhydroglucitol, 1-palmitoleoyl-glycerophosphocholine, palmitoleate, and creatine. These changes suggest reduced insulin sensitivity in aged FBN rats. Altogether, these data highlight skeletal muscle group-specific perturbations of glucose and lipid metabolism consistent with mitochondrial dysfunction in aged FBN rats. PMID:24652515

  12. Evolution of morphology in UHMWPE following accelerated aging: the effect of heating rates.

    PubMed

    Kurtz, S M; Pruitt, L A; Crane, D J; Edidin, A A

    1999-07-01

    Accelerated aging methods are used to evaluate the oxidative stability of UHMWPE components for total joint replacements. In this study, we traced the evolution of the crystalline morphology during accelerated thermal aging of UHMWPE in air with the intent of explaining previous, counterintuitive heating rate effects. GUR4150HP extruded rod stock material was machined into miniature (0.5 mm thick) specimens that were either gamma irradiated in air or in nitrogen (27 +/- 3 kGy) or left unirradiated (control). Accelerated aging in an air furnace (at 80 degrees C, atmospheric pressure) was performed on half of the test samples at a heating rate of 0.1 degrees C/min and at 5 degrees C/min for the remaining half. Although the initial heating rate, as measured by changes in density, did influence the absolute degradation rate by up to 214%, the heating rate effect did not appear to influence the relative ranking of UHMWPE in terms of its oxidative stability. The heating rate effect is more consistent with a kinetic mechanism of the oxidation process than it is with a previously hypothesized diffusion mechanism. UHMWPE morphology, as characterized using a transmission electron microscope (TEM), demonstrated considerable rearrangement of the crystalline regions as a result of the accelerated aging. The stacking of the lamellae observed after accelerated aging was not consistent with the morphology of naturally aged UHMWPE components. The observed differences in crystalline morphology likely result from the enhanced mobility of the polymer chains due to thermal aging and may be analogous to an annealing process.

  13. Simple simulation of the annual variation of the specific photosynthesis rate in Jiaozhou Bay

    NASA Astrophysics Data System (ADS)

    Ren, Ling; Zhang, Man-Ping; Lu, Xian-Kun; Feng, Shi-Zuo; Brockmann, Uwe H.

    2001-03-01

    A simple diagnostic simulation of the annual cycling of the surface specific photosynthesis rate (SPR) in Jiaozhou Bay is described in this paper. Light intensity, temperature and nutrients (nitrate+ammonia, phosphate) were considered as main factors controlling photosynthesis of phytoplankton and were introduced into the model by different function equations. The simulated variation of specific photosynthesis rate coincided with the measured data. Analysis of the effect of every factor on photosynthesis indicated that the variation of photosynthesis rate was controlled by all these three factors, while temperature showed good correlation with SPR as measurement showed. This diagnostic simulation yielded the values of some parameter relating with the photosynthesis in Jiaozhou Bay.

  14. Decreased growth rate of P. falciparum blood stage parasitemia with age in a holoendemic population.

    PubMed

    Pinkevych, Mykola; Petravic, Janka; Chelimo, Kiprotich; Vulule, John; Kazura, James W; Moormann, Ann M; Davenport, Miles P

    2014-04-01

    In malaria holoendemic settings, decreased parasitemia and clinical disease is associated with age and cumulative exposure. The relative contribution of acquired immunity against various stages of the parasite life cycle is not well understood. In particular, it is not known whether changes in infection dynamics can be best explained by decreasing rates of infection, or by decreased growth rates of parasites in blood. Here, we analyze the dynamics of Plasmodium falciparum infection after treatment in a cohort of 197 healthy study participants of different ages. We use both polymerase chain reaction (PCR) and microscopy detection of parasitemia in order to understand parasite growth rates and infection rates over time. The more sensitive PCR assay detects parasites earlier than microscopy, and demonstrates a higher overall prevalence of infection than microscopy alone. The delay between PCR and microscopy detection is significantly longer in adults compared with children, consistent with slower parasite growth with age. We estimated the parasite multiplication rate from delay to PCR and microscopy detections of parasitemia. We find that both the delay between PCR and microscopy infection as well as the differing reinfection dynamics in different age groups are best explained by a slowing of parasite growth with age.

  15. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    NASA Technical Reports Server (NTRS)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in

  16. Cost and Impact of Voluntary Medical Male Circumcision in South Africa: Focusing the Program on Specific Age Groups and Provinces

    PubMed Central

    Kripke, Katharine; Thambinayagam, Ananthy; Pillay, Yogan; Loykissoonlal, Dayanund; Bonnecwe, Collen; Barron, Peter; Kiwango, Eva; Castor, Delivette

    2016-01-01

    Background In 2012, South Africa set a goal of circumcising 4.3 million men ages 15–49 by 2016. By the end of March 2014, 1.9 million men had received voluntary medical male circumcision (VMMC). In an effort to accelerate progress, South Africa undertook a modeling exercise to determine whether circumcising specific client age groups or geographic locations would be particularly impactful or cost-effective. Results will inform South Africa’s efforts to develop a national strategy and operational plan for VMMC. Methods and Findings The study team populated the Decision Makers’ Program Planning Tool, Version 2.0 (DMPPT 2.0) with HIV incidence projections from the Spectrum/AIDS Impact Module (AIM), as well as national and provincial population and HIV prevalence estimates. We derived baseline circumcision rates from the 2012 South African National HIV Prevalence, Incidence and Behaviour Survey. The model showed that circumcising men ages 20–34 offers the most immediate impact on HIV incidence and requires the fewest circumcisions per HIV infection averted. The greatest impact over a 15-year period is achieved by circumcising men ages 15–24. When the model assumes a unit cost increase with client age, men ages 15–29 emerge as the most cost-effective group. When we assume a constant cost for all ages, the most cost-effective age range is 15–34 years. Geographically, the program is cost saving in all provinces; differences in the VMMC program’s cost-effectiveness across provinces were obscured by uncertainty in HIV incidence projections. Conclusion The VMMC program’s impact and cost-effectiveness vary by age-targeting strategy. A strategy focusing on men ages 15–34 will maximize program benefits. However, because clients older than 25 access VMMC services at low rates, South Africa could consider promoting demand among men ages 25–34, without denying services to those in other age groups. Uncertainty in the provincial estimates makes them

  17. Estimation of methane emission rate changes using age-defined waste in a landfill site.

    PubMed

    Ishii, Kazuei; Furuichi, Toru

    2013-09-01

    Long term methane emissions from landfill sites are often predicted by first-order decay (FOD) models, in which the default coefficients of the methane generation potential and the methane generation rate given by the Intergovernmental Panel on Climate Change (IPCC) are usually used. However, previous studies have demonstrated the large uncertainty in these coefficients because they are derived from a calibration procedure under ideal steady-state conditions, not actual landfill site conditions. In this study, the coefficients in the FOD model were estimated by a new approach to predict more precise long term methane generation by considering region-specific conditions. In the new approach, age-defined waste samples, which had been under the actual landfill site conditions, were collected in Hokkaido, Japan (in cold region), and the time series data on the age-defined waste sample's methane generation potential was used to estimate the coefficients in the FOD model. The degradation coefficients were 0.0501/y and 0.0621/y for paper and food waste, and the methane generation potentials were 214.4 mL/g-wet waste and 126.7 mL/g-wet waste for paper and food waste, respectively. These coefficients were compared with the default coefficients given by the IPCC. Although the degradation coefficient for food waste was smaller than the default value, the other coefficients were within the range of the default coefficients. With these new coefficients to calculate methane generation, the long term methane emissions from the landfill site was estimated at 1.35×10(4)m(3)-CH(4), which corresponds to approximately 2.53% of the total carbon dioxide emissions in the city (5.34×10(5)t-CO(2)/y).

  18. Assessment of the primary effect of aging on heart rate variability in humans.

    PubMed

    Fukusaki, C; Kawakubo, K; Yamamoto, Y

    2000-06-01

    Beat-to-beat heart rate variability (HRV), reflecting cardiac autonomic control mechanisms, is known to change with age. However, the degree to which this change is mediated by aging per se or by physiologic changes characteristic of normative aging is still unclear. This study was designed to examine the association of aerobic fitness, body habitus or obesity, and blood pressure with age-related changes in HRV. Resting HRV data was recorded from 373 healthy subjects (124 men, 249 women; age range, 16-69 y) and analyzed by coarse-graining spectral analysis to decompose the total spectral power into its harmonic and fractal components. The low- and high-frequency (LF, 0.0-0.15 Hz; HF, >0.15 Hz) harmonic components were calculated from the former, whereas the latter was used to calculate the integrated power (FR) and the spectral exponent , beta, which were, in turn, used to evaluate the overall complexity of HRV. Factor analysis was performed to test whether potentially age-related changes in the components of HRV might be observed secondarily through other variables affecting HRV. Significant (p <0.05) age-related changes in the harmonic (HF and LF) and fractal (FR and beta) components of HRV were generally consistent with those described in the literature. In addition, factor analysis showed that there was a unique common factor that primarily explained correlations among age, HF, and beta (p <0.05) without the contributions from LF, FR, aerobic fitness, body habitus or obesity, and blood pressure. It was concluded that, in this population-based sample, age-related changes in HF and beta, both of which reflect vagal modulation of heart rate, were primarily mediated by aging per se and not by physiologic changes characteristic of normative aging.

  19. Gender-specific regulation of response to thyroid hormone in aging

    PubMed Central

    2012-01-01

    Background Similar to other systems, the endocrine system is affected by aging. Thyroid hormone, the action of which is affected by many factors, has been shown to be associated with longevity. The most useful marker for the assessment of thyroid hormone action is TSH level. Although age and gender are believed to modify the pituitary set point or response to free thyroid hormone concentration, the precise age- and gender-dependent responses to thyroid hormone have yet to be reported. Methods We analyzed the results of 3564 thyroid function tests obtained from patients who received medication at both out- and inpatient clinics of Shinshu University Hospital. Subjects were from among those with thyroid function test results in the normal or mildly abnormal range. Based on a log-linear relationship between the concentrations of FHs and TSH, we established the putative resistance index to assess the relation between serum FH and TSH levels. Results Free thyroid hormone and TSH concentration showed an inverse log-linear relation. In males, there was a negative relationship between the free T3 resistance index and age. In females, although there were no relationships between age and FHs, the indices were positively related to age. Conclusions These findings indicated that there is a gender-specific response to thyroid hormone with aging. Although the TSH level is a useful marker for the assessment of peripheral thyroid hormone action, the values should be interpreted carefully, especially with regard to age- and gender-related differences. PMID:22280879

  20. Age-specific reference values for serum FSH and estradiol levels throughout the reproductive period.

    PubMed

    Grisendi, Valentina; Spada, Elena; Argento, Cindy; Plebani, Maddalena; Milani, Silvano; Seracchioli, Renato; Volpe, Annibale; La Marca, Antonio

    2014-06-01

    High serum day 3 FSH levels are associated with poor ovarian reserve and reduced fertility, but the interpretation of FSH values according to age is still not univocal. The purpose of this study was to determine age-dependent reference values in women with regular menstrual cycles and FSH as a guide for specialists. The study was performed at the Department of Mother-Infant of a University-based tertiary care centre. One-hundred ninety-two healthy normal menstruating women were recruited for the study. All patients attended the department on menstrual cycle day 3 for a blood sample for FSH and estradiol determination. A linear relationship between FSH or estradiol serum levels and age was observed. The FSH level increased by 0.11 IU for every year of age (1 IU for every 9 years of age). The values of FSH and estradiol corresponding to the 5th, 25th, 50th, 75th, 95th centiles for any specific age have been calculated. Serum FSH levels need to be interpreted according to age-dependent reference values. Serum FSH levels on 95th centile for any age may represent a warning sign for reduced ovarian reserve.

  1. A review of the equine age-related changes in the immune system: comparisons between human and equine aging, with focus on lung-specific immune-aging.

    PubMed

    Hansen, S; Baptiste, K E; Fjeldborg, J; Horohov, D W

    2015-03-01

    The equine aging process involves many changes to the immune system that may be related to genetics, the level of nutrition, the environment and/or an underlying subclinical disease. Geriatric horses defined as horses above the age of 20, exhibit a decline in body condition, muscle tone and general well-being. It is not known whether these changes contribute to decreased immune function or are the result of declining immune function. Geriatric years are characterized by increased susceptibility to infections and a reduced antibody response to vaccination as a result of changes in the immune system. Humans and horses share many of these age-related changes, with only a few differences. Thus, inflamm-aging and immunosenescence are well-described phenomena in both human and equine research, particularly in relation to the peripheral blood and especially the T-cell compartment. However, the lung is faced with unique challenges because of its constant interaction with the external environment and thus may not share similarities to peripheral blood when considering age-related changes in immune function. Indeed, recent studies have shown discrepancies in cytokine mRNA and protein expression between the peripheral blood and bronchoalveolar lavage immune cells. These results provide important evidence that age-related immune changes or 'dys-functions' are organ-specific.

  2. Optimal Control of Markov Processes with Age-Dependent Transition Rates

    SciTech Connect

    Ghosh, Mrinal K. Saha, Subhamay

    2012-10-15

    We study optimal control of Markov processes with age-dependent transition rates. The control policy is chosen continuously over time based on the state of the process and its age. We study infinite horizon discounted cost and infinite horizon average cost problems. Our approach is via the construction of an equivalent semi-Markov decision process. We characterise the value function and optimal controls for both discounted and average cost cases.

  3. Quantitative Analysis of Age Specific Variation in the Abundance of Human Female Parotid Salivary Proteins

    PubMed Central

    Ambatipudi, Kiran S.; Lu, Bingwen; Hagen, Fred K; Melvin, James E.; Yates, John R.

    2010-01-01

    Summary Human saliva is a protein-rich, easily accessible source of potential local and systemic biomarkers to monitor changes that occur under pathological conditions; however little is known about the changes in abundance associated with normal aging. In this study, we performed a comprehensive proteomic profiling of pooled saliva collected from the parotid glands of healthy female subjects, divided into two age groups 1 and 2 (20–30 and 55–65 years old, respectively). Hydrophobic charge interaction chromatography was used to separate high from low abundant proteins prior to characterization of the parotid saliva using multidimensional protein identification technology (MudPIT). Collectively, 532 proteins were identified in the two age groups. Of these proteins, 266 were identified exclusively in one age group, while 266 proteins were common to both groups. The majority of the proteins identified in the two age groups belonged to the defense and immune response category. Of note, several defense related proteins (e.g. lysozyme, lactoferrin and histatin-1) were significantly more abundant in group 2 as determined by G-test. Selected representative mass spectrometric findings were validated by western blot analysis. Our study reports the first quantitative analysis of differentially regulated proteins in ductal saliva collected from young and older female subjects. This study supports the use of high-throughput proteomics as a robust discovery tool. Such results provide a foundation for future studies to identify specific salivary proteins which may be linked to age-related diseases specific to women. PMID:19764810

  4. Adolescents' Domain-Specific Judgments about Different Forms of Civic Involvement: Variations by Age and Gender

    ERIC Educational Resources Information Center

    Metzger, Aaron; Ferris, Kaitlyn

    2013-01-01

    Domain-specific judgments about different forms of civic engagement were assessed in a sample 467 primarily White adolescents (M age = 15.26, range = 11-19). Adolescents reported on the obligatory nature and social praiseworthiness (respect) of different forms of civic involvement. Adolescents distinguished among four different categories of civic…

  5. Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing

    PubMed Central

    Collet, M.; Goenaga, J.; Arnqvist, G.

    2015-01-01

    Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex differences in the efficacy of selection on mitonuclear genotypes, which should result in differences between females and males in mitochondrial genetic effects. Mitonuclear genotype of a focal individual may also indirectly affect trait expression in the mating partner. We tested these predictions in the seed beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity, egg size, longevity). These results demonstrate important consequences of sex-specific mitonuclear epistasis for both mating partners, consistent with a role for mitonuclear genetic constraints upon sex-specific adaptive evolution. PMID:26732015

  6. Homicide rates among persons aged 10-24 years - United States, 1981-2010.

    PubMed

    2013-07-12

    Homicide disproportionately affects persons aged 10-24 years in the United States and consistently ranks in the top three leading causes of death in this age group, resulting in approximately 4,800 deaths and an estimated $9 billion in lost productivity and medical costs in 2010. To investigate trends in homicide among persons aged 10-24 years for the period 1981-2010, CDC analyzed National Vital Statistics System data on deaths caused by homicide of persons in this age group and examined trends by sex, age, race/ethnicity, and mechanism of injury. This report describes the results of that analysis, which indicated that homicide rates varied substantially during the study period, with a sharp rise from 1985 to 1993 followed by a decline that has slowed since 1999. During the period 2000-2010, rates declined for all groups, although the decline was significantly slower for males compared with females and for blacks compared with Hispanics and persons of other racial/ethnic groups. By mechanism of injury, the decline for firearm homicides from 2000 to 2010 was significantly slower than for nonfirearm homicides. The homicide rate among persons aged 10-24 years in 2010 was 7.5 per 100,000, the lowest in the 30-year study period. Primary prevention strategies remain critical, particularly among groups at increased risk for homicide.

  7. Mammography outcomes in a practice setting by age: prognostic factors, sensitivity, and positive biopsy rate.

    PubMed

    Linver, M N; Paster, S B

    1997-01-01

    The separate unplanned analysis of women ages 40-49 in population-based randomized controlled trials has resulted in demonstration of statistically significant breast cancer mortality reduction due to screening mammography in only two of the individual trials, and in all such trials only through meta-analysis. Therefore, many researchers have utilized the surrogate endpoints of tumor size and axillary lymph node status to evaluate screening efficacy. For the present study, these endpoints were evaluated in an audit of 854 screen-detected cancers found in 147,125 mammographic examinations performed in women over 40 between 1988 and 1994 in a community practice setting. The concerns that mammography in the 40-49 group has a lower sensitivity and higher biopsy rate were also addressed. Median invasive tumor size and lymph node positivity were found to be equally small (1.0-1.1 cm and 13.5-12.2%, respectively), and the sensitivity and overall biopsy rate were found to be constant over all ages 40 and above. Positive biopsy rate (PBR) varied directly with increasing age, paralleling the measured cancer detection rate in each decade, with no abrupt change at age 50. We conclude that modern mammography in a community practice setting can successfully detect breast cancers with favorable prognostic factors and achieve constant sensitivity and acceptable PBRs in all women over 40. Our data also suggest that many of the large differences seen by inappropriately dividing data at age 50 decrease or disappear when analysis is performed by decade.

  8. Particulate Air Pollution, Exceptional Aging, and Rates of Centenarians: A Nationwide Analysis of the United States, 1980–2010

    PubMed Central

    Baccarelli, Andrea A.; Hales, Nick; Burnett, Richard T.; Jerrett, Michael; Mix, Carter; Dockery, Douglas W.; Pope, C. Arden

    2016-01-01

    Background: Exceptional aging, defined as reaching age 85 years, shows geographic inequalities that may depend on local environmental conditions. Links between particulate pollution—a well-recognized environmental risk factor—and exceptional aging have not been investigated. Objectives: We conducted a nationwide analysis of ~28 million adults in 3,034 United States counties to determine whether local PM2.5 levels (particulate matter < 2.5 μm in aerodynamic diameter) affected the probability of becoming 85- to 94-year-olds or centenarians (100- to 104-year-olds) in 2010 for individuals who were 55–64 or 70–74 years old, respectively, in 1980. Methods: We used population-weighted regression models including county-level PM2.5 from hybrid land-use regression and geostatistical interpolation, smoking, obesity, sociodemographic, and age-specific migration variables. Results: On average, 2,295 and 71.4 per 10,000 of the 55- to 64- and 70- to 74-year-olds in 1980, respectively, remained in the 85- to 94- and 100- to 104-year-old population in 2010. An interquartile range (4.19 μg/m3) increase in PM2.5 was associated with 93.7 fewer 85- to 94-year-olds (p < 0.001) and 3.5 fewer centenarians (p < 0.05). These associations were nearly linear, were stable to model specification, and were detectable below the annual PM2.5 national standard. Exceptional aging was strongly associated with smoking, with an interquartile range (4.77%) increase in population who smoked associated with 181.9 fewer 85- to 94-year-olds (p < 0.001) and 6.4 fewer centenarians (p < 0.001). Exceptional aging was also associated with obesity rates and median income. Conclusions: Communities with the most exceptional aging have low ambient air pollution and low rates of smoking, poverty, and obesity. Improvements in these determinants may contribute to increasing exceptional aging. Citation: Baccarelli AA, Hales N, Burnett RT, Jerrett M, Mix C, Dockery DW, Pope CA III. 2016. Particulate air

  9. Effects of nutrients on specific growth rate of bacterioplankton in oligotrophic lake water cultures

    SciTech Connect

    Coveney, M.F.; Wetzel, R.G. )

    1992-01-01

    The effects of organic and inorganic nutrient additions on the specific growth rates of bacterioplankton in oligotrophic lake water cultures were investigated. Lake water was first passed through 0.8-{mu}m-pore-size filters (prescreening) to remove bacterivores and to minimize confounding effects of algae. Specific growth rates were calculated from changes in both bacterial cell numbers and biovolumes over 36 h. Gross specific growth rates in unmanipulated control samples were estimated through separate measurements of grazing losses by use of penicillin. The addition of mixed organic substrates alone to prescreened water did not significantly increase bacterioplankton specific growth rates. The addition of inorganic phosphorus alone significantly increased one or both specific growth rates in three of four experiments, and one experiment showed a secondary stimulation by organic substrates. The stimulatory effects of phosphorus addition were greatest concurrently with the highest alkaline phosphatase activity in the lake water. Because bacteria have been shown to dominate inorganic phosphorus uptake in other P-deficient systems, the demonstration that phosphorus, rather than organic carbon, can limit bacterioplankton growth suggests direct competition between phytoplankton and bacterioplankton for inorganic phosphorus.

  10. Heterogeneous Rates of Molecular Evolution and Diversification Could Explain the Triassic Age Estimate for Angiosperms.

    PubMed

    Beaulieu, Jeremy M; O'Meara, Brian C; Crane, Peter; Donoghue, Michael J

    2015-09-01

    Dating analyses based on molecular data imply that crown angiosperms existed in the Triassic, long before their undisputed appearance in the fossil record in the Early Cretaceous. Following a re-analysis of the age of angiosperms using updated sequences and fossil calibrations, we use a series of simulations to explore the possibility that the older age estimates are a consequence of (i) major shifts in the rate of sequence evolution near the base of the angiosperms and/or (ii) the representative taxon sampling strategy employed in such studies. We show that both of these factors do tend to yield substantially older age estimates. These analyses do not prove that younger age estimates based on the fossil record are correct, but they do suggest caution in accepting the older age estimates obtained using current relaxed-clock methods. Although we have focused here on the angiosperms, we suspect that these results will shed light on dating discrepancies in other major clades.

  11. Effect of ageing on CMV-specific CD8 T cells from CMV seropositive healthy donors

    PubMed Central

    Pita-Lopez, María Luisa; Gayoso, Inmaculada; DelaRosa, Olga; Casado, Javier G; Alonso, Corona; Muñoz-Gomariz, Elisa; Tarazona, Raquel; Solana, Rafael

    2009-01-01

    Background Ageing is associated with changes in the immune system with substantial alterations in T-lymphocyte subsets. Cytomegalovirus (CMV) is one of the factors that affect functionality of T cells and the differentiation and large expansions of CMV pp65-specific T cells have been associated with impaired responses to other immune challenges. Moreover, the presence of clonal expansions of CMV-specific T cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious diseases in the elderly. In this study, we analyse the effect of ageing on the phenotype and frequency of CMV pp65-specific CD8 T cell subsets according to the expression of CCR7, CD45RA, CD27, CD28, CD244 and CD85j. Results Peripheral blood from HLA-A2 healthy young, middle-aged and elderly donors was analysed by multiparametric flow cytometry using the HLA-A*0201/CMV pp65495–504 (NLVPMVATV) pentamer and mAbs specific for the molecules analysed. The frequency of CMV pp65-specific CD8 T cells was increased in the elderly compared with young and middle-aged donors. The proportion of naïve cells was reduced in the elderly, whereas an age-associated increase of the CCR7null effector-memory subset, in particular those with a CD45RAdim phenotype, was observed, both in the pentamer-positive and pentamer-negative CD8 T cells. The results also showed that most CMV pp65-specific CD8 T cells in elderly individuals were CD27/CD28 negative and expressed CD85j and CD244. Conclusion The finding that the phenotype of CMV pp65-specific CD8 T cells in elderly individuals is similar to the predominant phenotype of CD8 T cells as a whole, suggests that CMV persistent infections contributes to the age-related changes observed in the CD8 T cell compartment, and that chronic stimulation by other persistent antigens also play a role in T cell immunosenescence. Differences in subset distribution in elderly individuals showing a decrease in naive and an increase in

  12. Metabolic states with maximal specific rate carry flux through an elementary flux mode.

    PubMed

    Wortel, Meike T; Peters, Han; Hulshof, Josephus; Teusink, Bas; Bruggeman, Frank J

    2014-03-01

    Specific product formation rates and cellular growth rates are important maximization targets in biotechnology and microbial evolution. Maximization of a specific rate (i.e. a rate expressed per unit biomass amount) requires the expression of particular metabolic pathways at optimal enzyme concentrations. In contrast to the prediction of maximal product yields, any prediction of optimal specific rates at the genome scale is currently computationally intractable, even if the kinetic properties of all enzymes are available. In the present study, we characterize maximal-specific-rate states of metabolic networks of arbitrary size and complexity, including genome-scale kinetic models. We report that optimal states are elementary flux modes, which are minimal metabolic networks operating at a thermodynamically-feasible steady state with one independent flux. Remarkably, elementary flux modes rely only on reaction stoichiometry, yet they function as the optimal states of mathematical models incorporating enzyme kinetics. Our results pave the way for the optimization of genome-scale kinetic models because they offer huge simplifications to overcome the concomitant computational problems.

  13. The sensitivity and specificity of the social communication questionnaire for autism spectrum with respect to age.

    PubMed

    Barnard-Brak, Lucy; Brewer, Adam; Chesnut, Steven; Richman, David; Schaeffer, Anna Marie

    2016-08-01

    The age neutrality of the Social Communication Questionnaire (SCQ) was examined as a common screener for ASD. Mixed findings have been reported regarding the recommended cutoff score's ability to accurately classify an individual as at-risk for autism spectrum disorder (ASD) (sensitivity) versus accurately classifying an individual as not at-risk for ASD (specificity). With a sample from the National Database for Autism Research, this study examined the SCQ's sensitivity versus specificity. Analyses indicated that the actual sensitivity and specificity scores were lower than initially reported by the creators of the SCQ. Autism Res 2016, 9: 838-845. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  14. Proteomic analysis of specific brain proteins in aged SAMP8 mice treated with alpha-lipoic acid: implications for aging and age-related neurodegenerative disorders.

    PubMed

    Poon, H Fai; Farr, Susan A; Thongboonkerd, Visith; Lynn, Bert C; Banks, William A; Morley, John E; Klein, Jon B; Butterfield, D Allan

    2005-01-01

    Free radical-mediated damage to neuronal membrane components has been implicated in the etiology of Alzheimer's disease (AD) and aging. The senescence accelerated prone mouse strain 8 (SAMP8) exhibits age-related deterioration in memory and learning along with increased oxidative markers. Therefore, SAMP8 is a suitable model to study brain aging and, since aging is the major risk factor for AD and SAMP8 exhibits many of the biochemical findings of AD, perhaps as a model for and the early phase of AD. Our previous studies reported higher oxidative stress markers in brains of 12-month-old SAMP8 mice when compared to that of 4-month-old SAMP8 mice. Further, we have previously shown that injecting the mice with alpha-lipoic acid (LA) reversed brain lipid peroxidation, protein oxidation, as well as the learning and memory impairments in SAMP8 mice. Recently, we reported the use of proteomics to identify proteins that are expressed differently and/or modified oxidatively in aged SAMP8 brains. In order to understand how LA reverses the learning and memory deficits of aged SAMP8 mice, in the current study, we used proteomics to compare the expression levels and specific carbonyl levels of proteins in brains from 12-month-old SAMP8 mice treated or not treated with LA. We found that the expressions of the three brain proteins (neurofilament triplet L protein, alpha-enolase, and ubiquitous mitochondrial creatine kinase) were increased significantly and that the specific carbonyl levels of the three brain proteins (lactate dehydrogenase B, dihydropyrimidinase-like protein 2, and alpha-enolase) were significantly decreased in the aged SAMP8 mice treated with LA. These findings suggest that the improved learning and memory observed in LA-injected SAMP8 mice may be related to the restoration of the normal condition of specific proteins in aged SAMP8 mouse brain. Moreover, our current study implicates neurofilament triplet L protein, alpha-enolase, ubiquitous mitochondrial

  15. Relations between Concurrent Longitudinal Changes in Cognition, Depressive Symptoms, Self-Rated Health and Everyday Function in Normally Aging Octogenarians

    PubMed Central

    2016-01-01

    Ability to predict and prevent incipient functional decline in older adults may help prolong independence. Cognition is related to everyday function and easily administered, sensitive cognitive tests may help identify at-risk individuals. Factors like depressive symptoms and self-rated health are also associated with functional ability and may be as important as cognition. The purpose of this study was to investigate the relationship between concurrent longitudinal changes in cognition, depression, self-rated health and everyday function in a well-defined cohort of healthy 85 year olds that were followed-up at the age of 90 in the Elderly in Linköping Screening Assessment 85 study. Regression analyses were used to determine if cognitive decline as assessed by global (the Mini-Mental State Examination) and domain specific (the Cognitive Assessment Battery, CAB) cognitive tests predicted functional decline in the context of changes in depressive symptoms and self-rated health. Results showed deterioration in most variables and as many as 83% of these community-dwelling elders experienced functional difficulties at the age of 90. Slowing-down of processing speed as assessed by the Symbol Digits Modality Test (included in the CAB) accounted for 14% of the variance in functional decline. Worsening self-rated health accounted for an additional 6%, but no other variables reached significance. These results are discussed with an eye to possible preventive interventions that may prolong independence for the steadily growing number of normally aging old-old citizens. PMID:27551749

  16. Relations between Concurrent Longitudinal Changes in Cognition, Depressive Symptoms, Self-Rated Health and Everyday Function in Normally Aging Octogenarians.

    PubMed

    Classon, Elisabet; Fällman, Katarina; Wressle, Ewa; Marcusson, Jan

    2016-01-01

    Ability to predict and prevent incipient functional decline in older adults may help prolong independence. Cognition is related to everyday function and easily administered, sensitive cognitive tests may help identify at-risk individuals. Factors like depressive symptoms and self-rated health are also associated with functional ability and may be as important as cognition. The purpose of this study was to investigate the relationship between concurrent longitudinal changes in cognition, depression, self-rated health and everyday function in a well-defined cohort of healthy 85 year olds that were followed-up at the age of 90 in the Elderly in Linköping Screening Assessment 85 study. Regression analyses were used to determine if cognitive decline as assessed by global (the Mini-Mental State Examination) and domain specific (the Cognitive Assessment Battery, CAB) cognitive tests predicted functional decline in the context of changes in depressive symptoms and self-rated health. Results showed deterioration in most variables and as many as 83% of these community-dwelling elders experienced functional difficulties at the age of 90. Slowing-down of processing speed as assessed by the Symbol Digits Modality Test (included in the CAB) accounted for 14% of the variance in functional decline. Worsening self-rated health accounted for an additional 6%, but no other variables reached significance. These results are discussed with an eye to possible preventive interventions that may prolong independence for the steadily growing number of normally aging old-old citizens. PMID:27551749

  17. Increased Age and Race-Specific Incidence of Cervical Cancer After Correction for Hysterectomy Prevalence in the United States From 2000 to 2009

    PubMed Central

    Rositch, Anne F.; Nowak, Rebecca G.; Gravitt, Patti E.

    2014-01-01

    BACKGROUND Invasive cervical cancer is thought to decline in women over 65 years old, the age at which cessation of routine cervical cancer screening is recommended. However, national cervical cancer incidence rates do not account for the high prevalence of hysterectomy in the United States. METHODS Using estimates of hysterectomy prevalence from the Behavioral Risk Factor Surveillance System (BRFSS), hysterectomy-corrected age-standardized and age-specific incidence rates of cervical cancer were calculated from the Surveillance, Epidemiology, and End Results (SEER) 18 registry in the United States from 2000 to 2009. Trends in corrected cervical cancer incidence across age were analyzed using Joinpoint regression. RESULTS Unlike the relative decline in uncorrected rates, corrected rates continue to increase after age 35–39 (APCCORRECTED = 10.43) but at a slower rate than in 20–34 years (APCCORRECTED = 161.29). The highest corrected incidence was among 65- to 69-year-old women, with a rate of 27.4 cases per 100,000 women as opposed to the highest uncorrected rate of 15.6 cases per 100,000 aged 40 to 44 years. Correction for hysterectomy had the largest impact on older, black women given their high prevalence of hysterectomy. CONCLUSIONS Correction for hysterectomy resulted in higher age-specific cervical cancer incidence rates, a shift in the peak incidence to older women, and an increase in the disparity in cervical cancer incidence between black and white women. Given the high and nondeclining rate of cervical cancer in women over the age of 60 to 65 years, when women are eligible to exit screening, risk and screening guidelines for cervical cancer in older women may need to be reconsidered. PMID:24821088

  18. Correlation between relative growth rate and specific leaf area requires associations of specific leaf area with nitrogen absorption rate of roots.

    PubMed

    Osone, Yoko; Ishida, Atsushi; Tateno, Masaki

    2008-07-01

    Close correlations between specific leaf area (SLA) and relative growth rate (RGR) have been reported in many studies. However, theoretically, SLA by itself has small net positive effect on RGR because any increase in SLA inevitably causes a decrease in area-based leaf nitrogen concentration (LNCa), another RGR component. It was hypothesized that, for a correlation between SLA and RGR, SLA needs to be associated with specific nitrogen absorption rate of roots (SAR), which counteracts the negative effect of SLA on LNCa. Five trees and six herbs were grown under optimal conditions and relationships between SAR and RGR components were analyzed using a model based on balanced growth hypothesis. SLA varied 1.9-fold between species. Simulations predicted that, if SAR is not associated with SLA, this variation in SLA would cause a47% decrease in LNCa along the SLA gradient, leading to a marginal net positive effect on RGR. In reality, SAR was positively related to SLA, showing a 3.9-fold variation, which largely compensated for the negative effect of SLA on LNCa. Consequently, LNCa values were almost constant across species and a positive SLA-RGR relationship was achieved. These results highlight the importance of leaf-root interactions in understanding interspecific differences in RGR.

  19. p53 mutations associated with aging-related rise in cancer incidence rates.

    PubMed

    Richardson, Richard B

    2013-08-01

    TP53's role as guardian of the genome diminishes with age, as the probability of mutation increases. Previous studies have shown an association between p53 gene mutations and cancer. However, the role of somatic TP53 mutations in the steep rise in cancer rates with aging has not been investigated at a population level. This relationship was quantified using the International Agency for Research on Cancer (IARC) TP53 and GLOBOCAN cancer databases. The power function exponent of the cancer rate was calculated for 5-y age-standardized incidence or mortality rates for up to 25 cancer sites occurring in adults of median age 42 to 72 y. Linear regression analysis of the mean percentage of a cancer's TP53 mutations and the corresponding cancer exponent was conducted for four populations: worldwide, Japan, Western Europe, and the United States. Significant associations (P ≤ 0.05) were found for incidence rates but not mortality rates. Regardless of the population studied, positive associations were found for all cancer sites, with more significant associations for solid tumors, excluding the outlier prostate cancer or sex-related tumors. Worldwide and Japanese populations yielded P values as low as 0.002 and 0.005, respectively. For the United States, a significant association was apparent only when analysis utilized the Surveillance, Epidemiology, and End Results (SEER) database. This study found that TP53 mutations accounts for approximately one-quarter and one-third of the aging-related rise in the worldwide and Japanese incidence of all cancers, respectively. These significant associations between TP53 mutations and the rapid rise in cancer incidence with aging, considered with previously published literature, support a causal role for TP53 according to the Bradford-Hill criteria. However, questions remain concerning the contribution of TP53 mutations to neoplastic development and the role of factors such as genetic instability, obesity, and gene deficiencies other

  20. Evaluation of combined effects of ageing period and freezing rate on quality attributes of beef loins.

    PubMed

    Kim, Yuan H Brad; Liesse, Charlotte; Kemp, Robert; Balan, Prabhu

    2015-12-01

    The objective of our study was to evaluate the combined effects of ageing period and different freezing rates on meat quality attributes of beef loins. Pairs of loins (M. longissimus at 1 day post mortem) from 12 carcasses were divided into four equal portions and randomly assigned to four ageing/freezing treatments (aged only, frozen only, and 3 or 4 weeks ageing at -1.5°C then frozen). Two freezing methods (fast freezing by calcium chloride immersion or slow freezing by air freezer at -18°C) were applied to the loin sections. Fast freezing had no effect on shear force (P>0.05), but significantly improved the water-holding capacity of the aged/frozen loins by reducing purge and drip losses. Ageing-then-freezing significantly improved shear force values of loins compared to both the aged only and frozen only loins. These observations suggest that fast freezing will add more value to the aged/frozen/thawed meat by minimising the amount of water-loss due to the freezing/thawing process.

  1. Racial and ethnic differences in hospitalization rates among aged Medicare beneficiaries, 1998.

    PubMed

    Eggers, P W; Greenberg, L G

    2000-01-01

    Efforts to study racial variations in access to health care for minorities other than black persons have been hampered by a paucity of data. The Health Care Financing Administration (HCFA) has made efforts in the past few years to enhance the racial codes on the Medicare enrollment files to include Hispanic, Asian American, and Native American designations. This study examines hospitalization rates by these more detailed racial/ethnic groupings. The results show black, Hispanic, and Native American aged beneficiaries compared with white beneficiaries have higher hospitalization rates. Asian American beneficiaries have lower hospitalization rates. Rates of revascularization--coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA)--are lower for black, Hispanic, and Native American beneficiaries compared with white beneficiaries, while rates for Asian Americans are similar to rates for white beneficiaries.

  2. Racial and Ethnic Differences in Hospitalization Rates Among Aged Medicare Beneficiaries, 1998.

    PubMed

    Eggers, Paul W; Greenberg, Linda G

    2000-01-01

    Efforts to study racial variations in access to health care for minorities other than black persons have been hampered by a paucity of data. The Health Care Financing Administration (HCFA) has made efforts in the past few years to enhance the racial codes on the Medicare enrollment files to include Hispanic, Asian American, and Native American designations. This study examines hospitalization rates by these more detailed racial/ethnic groupings. The results show black, Hispanic, and Native American aged beneficiaries compared with white beneficiaries have higher hospitalization rates. Asian American beneficiaries have lower hospitalization rates. Rates of revascularization-coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA)-are lower for black, Hispanic, and Native American beneficiaries compared with white beneficiaries, while rates for Asian Americans are similar to rates for white beneficiaries.

  3. Generalized Treanor-Marrone model for state-specific dissociation rate coefficients

    NASA Astrophysics Data System (ADS)

    Kunova, O.; Kustova, E.; Savelev, A.

    2016-08-01

    We propose a simple and accurate model for state-specific dissociation rate coefficients based on the widely used Treanor-Marrone model. It takes into account the dependence of its parameter on temperature and vibrational level and can be used with arbitrary vibrational ladder. The model is validated by comparisons with state-specific dissociation rate coefficients of O2 and N2 obtained using molecular dynamics, and its good accuracy is demonstrated. Non-equilibrium kinetics of O2/O and N2/N mixtures under heat bath conditions is studied; applying the optimized Treanor-Marrone model leads to more efficient dissociation and vibrational relaxation.

  4. Can Neglected Tropical Diseases Compromise Human Wellbeing in Sex-, Age-, and Trait-Specific Ways?

    PubMed Central

    Geary, David C.

    2016-01-01

    Traits that facilitate competition for reproductive resources or that influence mate choice have evolved to signal resilience to infectious disease and other stressors. As a result, the dynamics of competition and choice can, in theory, be used to generate predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species, including humans. These dynamics and associated vulnerabilities are reviewed for nonhuman species, focusing on traits that are compromised by exposure to parasites. Using the same approach, sex-, age-, and trait-specific vulnerabilities to parasitic disease are illustrated for children’s and adolescent’s physical growth and fitness. Suggestions are then provided for widening the assessment of human vulnerabilities to include age-appropriate measures of behavioral (e.g., children’s play) and cognitive (e.g., language fluency) traits. These are traits that are likely to be compromised by infection in age- and sex-specific ways. Inclusion of these types of measures in studies of neglected tropic diseases has the potential to provide a more nuanced understanding of how these diseases undermine human wellbeing and may provide a useful means to study the efficacy of associated treatments. PMID:27077746

  5. Can Neglected Tropical Diseases Compromise Human Wellbeing in Sex-, Age-, and Trait-Specific Ways?

    PubMed

    Geary, David C

    2016-04-01

    Traits that facilitate competition for reproductive resources or that influence mate choice have evolved to signal resilience to infectious disease and other stressors. As a result, the dynamics of competition and choice can, in theory, be used to generate predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species, including humans. These dynamics and associated vulnerabilities are reviewed for nonhuman species, focusing on traits that are compromised by exposure to parasites. Using the same approach, sex-, age-, and trait-specific vulnerabilities to parasitic disease are illustrated for children's and adolescent's physical growth and fitness. Suggestions are then provided for widening the assessment of human vulnerabilities to include age-appropriate measures of behavioral (e.g., children's play) and cognitive (e.g., language fluency) traits. These are traits that are likely to be compromised by infection in age- and sex-specific ways. Inclusion of these types of measures in studies of neglected tropic diseases has the potential to provide a more nuanced understanding of how these diseases undermine human wellbeing and may provide a useful means to study the efficacy of associated treatments. PMID:27077746

  6. Retrospective Ratings of Emotions: the Effects of Age, Daily Tiredness, and Personality

    PubMed Central

    Mill, Aire; Realo, Anu; Allik, Jüri

    2016-01-01

    Remembering the emotions we have experienced in the past is the core of one's unique life-experience. However, there are many factors, both at the state and trait level that can affect the way past feelings are seen. The main aim of the current study was to examine the impact of individual differences on systematic biases in retrospective ratings compared to the momentary experience of basic emotions such as sadness, fear, happiness, and anger. To this end, an experience sampling study across 2 weeks was conducted using a younger and an older age-group; the experience of momentary emotions was assessed on 7 randomly determined occasions per day, the retrospective ratings being collected at the end of each day about that day, as well as at the end of the study about the previous 2 weeks. The results indicated that age and daily tiredness have significant effects on retrospective emotion ratings over a 1-day period (state level), enhancing the retrospective ratings of negative emotions and decreasing the ratings of felt happiness. Whereas personality traits influence the more long-term emotion experience (trait level), with all Big Five personality traits having selective impact on retrospective emotion ratings of fear, sadness, happiness, and anger. Findings provide further evidence about the systematic biases in retrospective emotion ratings, suggesting that, although retrospective ratings are based on momentary experience, daily tiredness and personality traits systematically influence the way in which past feelings are seen. PMID:26793142

  7. Quantitative physiology of Saccharomyces cerevisiae at near-zero specific growth rates.

    PubMed

    Boender, Léonie G M; de Hulster, Erik A F; van Maris, Antonius J A; Daran-Lapujade, Pascale A S; Pronk, Jack T

    2009-09-01

    Growth at near-zero specific growth rates is a largely unexplored area of yeast physiology. To investigate the physiology of Saccharomyces cerevisiae under these conditions, the effluent removal pipe of anaerobic, glucose-limited chemostat culture (dilution rate, 0.025 h(-1)) was fitted with a 0.22-microm-pore-size polypropylene filter unit. This setup enabled prolonged cultivation with complete cell retention. After 22 days of cultivation, specific growth rates had decreased below 0.001 h(-1) (doubling time of >700 h). Over this period, viability of the retentostat cultures decreased to ca. 80%. The viable biomass concentration in the retentostats could be accurately predicted by a maintenance coefficient of 0.50 mmol of glucose g(-1) of biomass h(-1) calculated from anaerobic, glucose-limited chemostat cultures grown at dilution rates of 0.025 to 0.20 h(-1). This indicated that, in contrast to the situation in several prokaryotes, maintenance energy requirements in S. cerevisiae do not substantially change at near-zero specific growth rates. After 22 days of retentostat cultivation, glucose metabolism was predominantly geared toward alcoholic fermentation to meet maintenance energy requirements. The strict correlation between glycerol production and biomass formation observed at higher specific growth rates was not maintained at the near-zero growth rates reached in the retentostat cultures. In addition to glycerol, the organic acids acetate, d-lactate, and succinate were produced at low rates during prolonged retentostat cultivation. This study identifies robustness and by-product formation as key issues in attempts to uncouple growth and product formation in S. cerevisiae.

  8. Quantitative Physiology of Saccharomyces cerevisiae at Near-Zero Specific Growth Rates

    PubMed Central

    Boender, Léonie G. M.; de Hulster, Erik A. F.; van Maris, Antonius J. A.; Daran-Lapujade, Pascale A. S.; Pronk, Jack T.

    2009-01-01

    Growth at near-zero specific growth rates is a largely unexplored area of yeast physiology. To investigate the physiology of Saccharomyces cerevisiae under these conditions, the effluent removal pipe of anaerobic, glucose-limited chemostat culture (dilution rate, 0.025 h−1) was fitted with a 0.22-μm-pore-size polypropylene filter unit. This setup enabled prolonged cultivation with complete cell retention. After 22 days of cultivation, specific growth rates had decreased below 0.001 h−1 (doubling time of >700 h). Over this period, viability of the retentostat cultures decreased to ca. 80%. The viable biomass concentration in the retentostats could be accurately predicted by a maintenance coefficient of 0.50 mmol of glucose g−1 of biomass h−1 calculated from anaerobic, glucose-limited chemostat cultures grown at dilution rates of 0.025 to 0.20 h−1. This indicated that, in contrast to the situation in several prokaryotes, maintenance energy requirements in S. cerevisiae do not substantially change at near-zero specific growth rates. After 22 days of retentostat cultivation, glucose metabolism was predominantly geared toward alcoholic fermentation to meet maintenance energy requirements. The strict correlation between glycerol production and biomass formation observed at higher specific growth rates was not maintained at the near-zero growth rates reached in the retentostat cultures. In addition to glycerol, the organic acids acetate, d-lactate, and succinate were produced at low rates during prolonged retentostat cultivation. This study identifies robustness and by-product formation as key issues in attempts to uncouple growth and product formation in S. cerevisiae. PMID:19592533

  9. Ageing gender-specific "Biomarkers of Homeostasis", to protect ourselves against the diseases of the old age.

    PubMed

    Berghella, Anna Maria; Contasta, Ida; Marulli, Giuseppe; D'Innocenzo, Carlo; Garofalo, Ferdinando; Gizzi, Francesca; Bartolomucci, Marco; Laglia, Giacomo; Valeri, Marisa; Gizzi, Mario; Friscioni, Mauro; Barone, Mario; Del Beato, Tiziana; Secinaro, Enzo; Pellegrini, Patrizia

    2014-01-01

    Low-grade inflammatory state causes the development of the principal chronic-degenerative pathologies related with ageing. Consequently, it is required a better comprehension of the physiologic origins and the consequences of the low-grade inflammatory state for the identification of 1) the basic mechanisms that lead to the chronic inflammatory state and, after that, to the progression toward the pathologies and 2) the parallel identification of the prognostic biomarkers typical of these passages. These biomarkers could bring to several improvements in the health quality, allowing an early diagnosis and more effective treatments for: a) the prevention strategies on the healthy population, to assure a healthy longevity and b) the identification of personalized treatment in patients, to assure the benefit of the therapy. For the identification of these biomarkers it is necessary to consider that the ageing processes produce alterations of the physiologic systems and that these modifications compromise the communications between these networks: this state constitutes an obstacle for an appropriate physiologic homeostasis, that plays a fundamental role for the safeguard of the health. It is also to be considered that immune senescence affects both men and women, but it does it in different ways: a sexual dimorphism of immune pathways in the setting of immune response homeostasis is normally present, as we previously underlined. Therefore we hypothesize that, in order to prevent the development of the chronic-degenerative pathologies related with ageing, it is important to identify "Biomarkers of Homeostasis " specific for each gender: these are biologic molecules that should be measurable in a practical and no-invasive way and whose variations can quantify the male and female risk of losing the physiologic system homeostatic capacity. This competence is not only critical in the control of inflammation, but it is also prognostic for the passages from low

  10. Age-specific Parkinson disease risk in GBA mutation carriers: information for genetic counseling

    PubMed Central

    Rana, Huma Q.; Balwani, Manisha; Bier, Louise; Alcalay, Roy N.

    2012-01-01

    Purpose We sought to estimate age-specific risk of Parkinson disease in relatives of patients with Gaucher disease, who are obligate carriers of GBA mutations and who were not ascertained by family history of Parkinson disease. Methods A validated family history of Parkinson disease questionnaire was administered to 119 patients with Gaucher disease who were evaluated at the Mount Sinai School of Medicine from 2009 to 2012; the ages of their parents, siblings, and children, history of Parkinson disease, age at onset of Parkinson disease, and ethnic background were obtained. Kaplan–Meier survival curves were used to estimate age-specific Parkinson disease penetrance among parents of patients with Gaucher disease, who are obligatory GBA mutation carriers. Results Two participants with Gaucher disease were affected by Parkinson disease (5.4% of those who were 60 years or older). Of the 224 informative parents of patients with Gaucher disease, 11 had Parkinson disease (4.9%). Among the parents (obligatory carriers), cumulative risk of Parkinson disease by ages 65 and 85 was estimated to be 2.2% ±2.1% and 10.9% ±7.2%, respectively. Conclusion We provide useful age-specific estimates of Parkinson disease penetrance in patients with Gaucher disease and GBA heterozygous carriers for genetic counseling. Although GBA mutations may increase the risk for PD, the vast majority of patients with Gaucher disease and heterozygotes may not develop the disease. Further studies are needed to identify what modifies the risk of Parkinson disease in GBA mutation carriers. PMID:22935721

  11. Taste perception with age: generic or specific losses in supra-threshold intensities of five taste qualities?

    PubMed

    Mojet, Jos; Heidema, Johannes; Christ-Hazelhof, Elly

    2003-06-01

    The influence of ageing on supra-threshold intensity perception of NaCl, KCl, sucrose, aspartame, acetic acid, citric acid, caffeine, quinine HCl, monosodium glutamate (MSG) and inosine 5'-monophosphate (IMP) dissolved in water and in 'regular' product was studied in 21 young (19-33 years) and 21 elderly (60-75 years) persons. While the relative perception (intensity discrimination) seems to be remarkably resistant to the effect of ageing, the absolute perception (intensity rating) decreased with age for all tastants in water, but only for the salty and sweet tastants in product. When assessed while wearing a nose clip, only the perception of salty tastants was diminished with age. The slopes of the psychophysical functions were flatter in the elderly than in the young for the sweet, bitter and umami tastants in water, and for the sour tastants in product only. The age effects found were almost exclusively generic and never compound-specific within a taste. This study indicates that the relevance of determining intensities of tastants dissolved in water for the 'real life' perception of taste in complex food is rather limited.

  12. Primary care presentations at emergency departments: rates and reasons by age and sex.

    PubMed

    Siminski, Peter; Bezzina, Andrew J; Lago, Luise P; Eagar, Kathy

    2008-11-01

    Primary care presentations at emergency departments (EDs) have been the subject of much attention in recent years. This paper is a demographic analysis using administrative data from the Emergency Department Information System (EDIS) for 2005 of such presentations in New South Wales EDs and of self-reported reasons for presentation. Age and sex differences in the reasons given by patients for such presentations are analysed using data from a survey of patients conducted in a subset of EDs in 2004. The rate of "potential primary care" presentations varies greatly with age and to a lesser extent with sex. Almost half (47%) of these presentations are made by people under 25 years of age. Children aged 0-4 years account for 14% of the total. The pattern is distinctly different to the corresponding rate of ED presentations that do not fit the "potential primary care" definition. Reasons given for "potential primary care" presentations are consistent across all age groups, reflecting self-assessed urgency, access to diagnostics and self-assessed complexity. Older "primary care" patients are particularly unlikely to give reasons associated with GP affordability or availability for their presentations. Young adults' responses are consistent with the overall population, and children under the age of five seem most susceptible to availability issues.

  13. Diabetes death rates among youths aged ≤ 19 years--United States, 1968-2009.

    PubMed

    2012-11-01

    Although diabetes mellitus most often is diagnosed in adulthood, it remains one of the most common serious chronic diseases of childhood. Youths with diabetes are at risk for diabetes-related mortality because of acute complications that can result from the condition, including diabetic ketoacidosis and hypoglycemia. In the United States in 2010, an estimated 215,000 persons aged ≤ 19 years had diagnosed diabetes. Medical care for diabetes has improved considerably in recent decades, leading to improved survival rates. However, recent trends in diabetes death rates among youths aged <10 years and 10-19 years in the United States have not been reported. To assess these trends, CDC analyzed data from the National Vital Statistics System for deaths in the United States with diabetes listed as the underlying cause during 1968-2009. This report highlights the results of that analysis, which found that diabetes-related mortality decreased 61%, from an annual rate of 2.69 per million for the period 1968-1969 to a rate of 1.05 per million in 2008-2009. The percentage decrease was greater among youths aged <10 years (78%) than among youths aged 10-19 years (52%). These findings demonstrate improvements in diabetes mortality among youths but also indicate a need for continued improvement in diabetes diagnosis and care. PMID:23114253

  14. Measuring Impulsivity in School-Aged Boys and Examining Its Relationship with ADHD and Odd Ratings

    ERIC Educational Resources Information Center

    Avila, Cesar; Cuenca, Isabel; Felix, Vicente; Parcet, Maria-Antonia; Miranda, Ana

    2004-01-01

    Seven different laboratory measures of impulsivity were administered to a group of 165 school-aged boys. Parents' and teachers' ratings of Attention Deficit and Hyperactivity Disorder and Oppositional/Defiant Disorder were also obtained. Factor analyses of impulsivity measures revealed the existence of a strong Inhibitory Control Factor including…

  15. Accounting for Recent Declines in Employment Rates among Working-Aged Men and Women with Disabilities.

    ERIC Educational Resources Information Center

    Bound, John; Waidmann, Timothy

    2002-01-01

    During the 1990s, employment rates of people with disabilities fell and the number of working-age people receiving Social Security Disability Insurance (SSDI) benefits increased dramatically, Analysis of Current Population Survey and disability insurance data suggests that growth in the SSDI program accounts for much of the decline in employment…

  16. Supervisor-Subordinate Age Dissimilarity and Performance Ratings: The Buffering Effects of Supervisory Relationship and Practice

    ERIC Educational Resources Information Center

    Van der Heijden, Beatrice I. J. M.; Scholarios, Dora; Van der Schoot, Esther; Jedrzejowicz, Piotr; Bozionelos, Nikos; Epitropaki, Olga; Knauth, Peter; Marzec, Izabela; Mikkelsen, Aslaug; Van der Heijde, Claudia

    2010-01-01

    Using 394 pairs of employees and their immediate supervisors working in the Information and Communication Technology (ICT) sector in three northern European countries, this study examined the effect of workplace moderators on the link between relational demography and supervisor ratings of performance. Directional age differences between superior…

  17. At the heart of aging: is it metabolic rate or stability?

    PubMed

    Olshansky, S Jay; Rattan, Suresh I S

    2005-01-01

    Foundational changes in science are rare, but in the field of biogerontology there is a new theory of aging that may shake things up. The conventional wisdom about duration of life is based on an old idea known as the "rate of living" theory, which suggests that aging is caused by the loss of some vital substance. The modern version of this theory is that duration of life is influenced by the relative speed of a species' resting metabolism. However, empirical evidence does not consistently support this hypothesis. In an article published recently by mathematician/biologist Lloyd Demetrius, it is suggested that the most important factor involved in duration of life is not metabolic rate or oxidative stress, but metabolic stability. If Demetrius is correct, his theory will have important implications for intervention research. For example, if the metabolic rate/oxidative stress theory is correct, efforts to intervene in the aging process should be directed at finding ways to reduce metabolic rate, lessen the production of reactive oxygen species (ROS), improve antioxidant defenses, or increase the quantity of antioxidants. If the metabolic stability hypothesis is correct, efforts to intervene in the aging process should be directed at finding ways to increase the stability of the steady state values of ROS, increase the robustness of metabolic networks, or improve the stability of antioxidant enzymes. For now there is reason to believe that Demetrius' theory deserves further consideration - whether it meets the test of a paradigm shift has yet to be determined. PMID:16333763

  18. Electroencephalogram and Heart Rate Measures of Working Memory at 5 and 10 Months of Age

    ERIC Educational Resources Information Center

    Cuevas, Kimberly; Bell, Martha Ann; Marcovitch, Stuart; Calkins, Susan D.

    2012-01-01

    We recorded electroencephalogram (EEG; 6-9 Hz) and heart rate (HR) from infants at 5 and 10 months of age during baseline and performance on the looking A-not-B task of infant working memory (WM). Longitudinal baseline-to-task comparisons revealed WM-related increases in EEG power (all electrodes) and EEG coherence (medial frontal-occipital…

  19. Age-Adjustment and Related Epidemiology Rates in Education and Research

    ERIC Educational Resources Information Center

    Baker, John D.; Kruckman, Laurence; George, Joyce

    2006-01-01

    A quick review of introductory textbooks reveals that while gerontology authors and instructors introduce some aspect of demography and epidemiology data, there is limited focus on age adjustment or other important epidemiology rates. The goal of this paper is to reintroduce a variety of basic epidemiology strategies such as incidence, prevalence,…

  20. Testing the effect of metabolic rate on DNA variability at the intra-specific level.

    PubMed

    McGaughran, Angela; Holland, Barbara R

    2010-01-01

    We tested the metabolic rate hypothesis (whereby rates of mtDNA evolution are postulated to be mediated primarily by mutagenic by-products of respiration) by examining whether mass-specific metabolic rate was correlated with root-to-tip distance on a set of mtDNA trees for the springtail Cryptopygus antarcticus travei from sub-Antarctic Marion Island.Using Bayesian analyses and a novel application of the comparative phylogenetic method, we did not find significant evidence that contemporary metabolic rates directly correlate with mutation rate (i.e., root-to-tip distance) once the underlying phylogeny is taken into account. However, we did find significant evidence that metabolic rate is dependent on the underlying mtDNA tree, or in other words, lineages with related mtDNA also have similar metabolic rates.We anticipate that future analyses which apply this methodology to datasets with longer sequences, more taxa, or greater variability will have more power to detect a significant direct correlation between metabolic rate and mutation rate. We conclude with suggestions for future analyses that would extend the preliminary approach applied here, in particular highlighting ways to tease apart oxidative stress effects from the effects of population size and/or selection coefficients operating on the molecular evolutionary rate. PMID:20300626

  1. Isolating global and specific factors in developmental dyslexia: a study based on the rate and amount model (RAM).

    PubMed

    Zoccolotti, Pierluigi; De Luca, Maria; Judica, Anna; Spinelli, Donatella

    2008-04-01

    Using the reading-age match approach, research on developmental dyslexia focuses on specific (e.g., phonological) deficits and disregards the possible role of global influences in determining the disturbance. In the present study, we set out to investigate the role of both global and specific factors in Italian developmental dyslexics using the rate-amount model (RAM; Faust et al. in Psychol Bull 125:777-799, 1999). Vocal reaction times (RT) in naming pictures, words and non-words of varying length were measured in a group of 26 sixth- to eighth-grade dyslexics and 81 age-matched control readers. Dyslexics' raw RTs showed greater lexicality (longer RTs to non-words than words) and length (longer RTs to long stimuli than short ones) effects than controls'. We found that one global factor predicted most individual variation in naming words and non-words, but not pictures. When data transformations, effective in controlling for the global factor, were applied to the data, the greater lexicality effect in dyslexics vanished, due to the influence of the global factor and not a specific failure in the non-lexical reading procedure. Conversely, the greater length effect in dyslexics persisted. Overall, dyslexics' reading performance was best explained as due to the influence of both a global factor for processing orthographic material prelexically and to the specific influence of stimulus length. This conceptualisation appears more promising for bridging the gap between behavioural and functional imaging studies than traditional approaches, which focus on the detection of specific reading deficits. It is concluded that RAM is a useful tool for disentangling the components that are impaired in reading and for defining the characteristics of the global factor, because the paradigm is more powerful for studying developmental dyslexia than the reading-age match method.

  2. Age-specific cost of first reproduction in female southern elephant seals.

    PubMed

    Desprez, Marine; Harcourt, Robert; Hindell, Mark A; Cubaynes, Sarah; Gimenez, Olivier; McMahon, Clive R

    2014-05-01

    When to commence breeding is a crucial life-history decision that may be the most important determinant of an individual's lifetime reproductive output and can have major consequences on population dynamics. The age at which individuals first reproduce is an important factor influencing the intensity of potential costs (e.g. reduced survival) involved in the first breeding event. However, quantifying age-related variation in the cost of first reproduction in wild animals remains challenging because of the difficulty in reliably recording the first breeding event. Here, using a multi-event capture-recapture model that accounts for both imperfect detection and uncertainty in the breeding status on an 18-year dataset involving 6637 individuals, we estimated age and state-specific survival of female elephant seals (Mirounga leonina) in the declining Macquarie Island population. We detected a clear cost of first reproduction on survival. This cost was higher for both younger first-time breeders and older first-time breeders compared with females recruiting at age four, the overall mean age at first reproduction. Neither earlier primiparity nor delaying primiparity appear to confer any evolutionary advantage, rather the optimal strategy seems to be to start breeding at a single age, 4 years.

  3. Gene Expression in the Hippocampus: Regionally Specific Effects of Aging and Caloric Restriction

    PubMed Central

    Zeier, Zane; Madorsky, Irina; Xu, Ying; Ogle, William O.; Notterpek, Lucia; Foster, Thomas C.

    2010-01-01

    We measured changes in gene expression, induced by aging and caloric restriction (CR), in three hippocampal subregions. When analysis included all regions, aging was associated with expression of genes linked to mitochondrial dysfunction, inflammation, and stress responses, and in some cases, expression was reversed by CR. An age-related increase in ubiquintination was observed, including increased expression of ubiquitin conjugating enzyme genes and cytosolic ubiquitin immunoreactivity. CR decreased cytosolic ubiquitin and upregulated deubiquitinating genes. Region specific analyses indicated that CA1 was more susceptible to aging stress, exhibiting a greater number of altered genes relative to CA3 and the dentate gyrus (DG), and an enrichment of genes related to the immune response and apoptosis. CA3 and the DG were more responsive to CR, exhibiting marked changes in the total number of genes across diet conditions, reversal of age-related changes in p53 signaling, glucocorticoid receptor signaling, and enrichment of genes related to cell survival and neurotrophic signaling. Finally, CR differentially influenced genes for synaptic plasticity in CA1 and CA3. It is concluded that regional disparity in response to aging and CR relates to differences in vulnerability to stressors, the availability of neurotrophic, and cell survival mechanisms, and differences in cell function. PMID:21055414

  4. Age-specific toxicity of copper to larval topsmelt Atherinops affinis

    SciTech Connect

    McNulty, H.R.; Anderson, B.S.; Hunt, J.W.; Turpen, S.L.; Singer, M.M. . Inst. of Marine Sciences)

    1994-03-01

    The age-specific sensitivity of topsmelt (Atherinops affinis) larvae to copper was assessed. A series of 7-d growth and survival experiments were conducted using cohorts of larval fish isolated into different age groups of 0, 1, 3, 5, 7, 9, 11, 15, and 20 d post-hatch. Fish aged 0, 3, and 5 d were less sensitive to copper chloride than fish [>=] 7 d old. The median lethal concentration (LC50) for copper ranged from 365 [mu]g L[sup [minus]1] in 0-d larvae, to 137 [mu]g L[sup [minus]1] in 20-d larvae. NOECs remained relatively constant for all ages: 180 [mu]g L[sup [minus]1] for 1- and 3-d-old fish, 100 [mu]g L[sup [minus]1] for all other cohorts. Regression analysis indicated a significant negative correlation between LC50 and gill surface area and cutaneous surface area. Although these correlations were expected because both morphometrics increase with age, the relationships between increasing respiratory surface area and LC50 may indicate that the increase in sensitivity with larval age is related to an increase in copper uptake, either cutaneously or branchially. GSA increased more than seven fold between hatch and 20 d, whereas CSA increased only threefold throughout the same period.

  5. Age-specific cost of first reproduction in female southern elephant seals

    PubMed Central

    Desprez, Marine; Harcourt, Robert; Hindell, Mark A.; Cubaynes, Sarah; Gimenez, Olivier; McMahon, Clive R.

    2014-01-01

    When to commence breeding is a crucial life-history decision that may be the most important determinant of an individual's lifetime reproductive output and can have major consequences on population dynamics. The age at which individuals first reproduce is an important factor influencing the intensity of potential costs (e.g. reduced survival) involved in the first breeding event. However, quantifying age-related variation in the cost of first reproduction in wild animals remains challenging because of the difficulty in reliably recording the first breeding event. Here, using a multi-event capture–recapture model that accounts for both imperfect detection and uncertainty in the breeding status on an 18-year dataset involving 6637 individuals, we estimated age and state-specific survival of female elephant seals (Mirounga leonina) in the declining Macquarie Island population. We detected a clear cost of first reproduction on survival. This cost was higher for both younger first-time breeders and older first-time breeders compared with females recruiting at age four, the overall mean age at first reproduction. Neither earlier primiparity nor delaying primiparity appear to confer any evolutionary advantage, rather the optimal strategy seems to be to start breeding at a single age, 4 years. PMID:24872464

  6. Age-specific cost of first reproduction in female southern elephant seals.

    PubMed

    Desprez, Marine; Harcourt, Robert; Hindell, Mark A; Cubaynes, Sarah; Gimenez, Olivier; McMahon, Clive R

    2014-05-01

    When to commence breeding is a crucial life-history decision that may be the most important determinant of an individual's lifetime reproductive output and can have major consequences on population dynamics. The age at which individuals first reproduce is an important factor influencing the intensity of potential costs (e.g. reduced survival) involved in the first breeding event. However, quantifying age-related variation in the cost of first reproduction in wild animals remains challenging because of the difficulty in reliably recording the first breeding event. Here, using a multi-event capture-recapture model that accounts for both imperfect detection and uncertainty in the breeding status on an 18-year dataset involving 6637 individuals, we estimated age and state-specific survival of female elephant seals (Mirounga leonina) in the declining Macquarie Island population. We detected a clear cost of first reproduction on survival. This cost was higher for both younger first-time breeders and older first-time breeders compared with females recruiting at age four, the overall mean age at first reproduction. Neither earlier primiparity nor delaying primiparity appear to confer any evolutionary advantage, rather the optimal strategy seems to be to start breeding at a single age, 4 years. PMID:24872464

  7. Switching rates in health insurance markets decrease with age: empirical evidence and policy implications from the Netherlands.

    PubMed

    Duijmelinck, Daniëlle M I D; van de Ven, Wynand P M M

    2016-04-01

    All consumer groups with specific preferences must feel free to easily switch insurer in order to discipline insurers to be responsive to consumers' heterogeneous preferences. This paper provides insight into the switching behaviour of low-risks (i.e. young or healthy consumers) and high-risks (i.e. elderly or unhealthy consumers) in the Netherlands in the period 2009-2012. We analysed: (1) administrative data with objective health status information (i.e. medically diagnosed diseases and pharmaceutical use) and information on health care expenses of nearly the entire Dutch population (n=15.3 million individuals) and (2) three-year sample data (n=1152 individuals). Our findings indicate that switching rates strongly decrease with age. For example, in 2009, consumers aged 25-44 switched 10 times more than consumers aged 75 or older. Another finding is that switching rates decrease as the predicted health care expenses increase. Although healthy consumers switch twice as much as unhealthy consumers, this difference becomes much smaller after adjusting for age. We conclude that our findings can be explained by higher perceived switching costs by elderly consumers than by young consumers. Consequently, insurers have low incentives to act as quality-conscious purchasers of care for the elderly consumers. Therefore, strategies should be developed to increase the choice of insurer of elderly consumers.

  8. Switching rates in health insurance markets decrease with age: empirical evidence and policy implications from the Netherlands.

    PubMed

    Duijmelinck, Daniëlle M I D; van de Ven, Wynand P M M

    2016-04-01

    All consumer groups with specific preferences must feel free to easily switch insurer in order to discipline insurers to be responsive to consumers' heterogeneous preferences. This paper provides insight into the switching behaviour of low-risks (i.e. young or healthy consumers) and high-risks (i.e. elderly or unhealthy consumers) in the Netherlands in the period 2009-2012. We analysed: (1) administrative data with objective health status information (i.e. medically diagnosed diseases and pharmaceutical use) and information on health care expenses of nearly the entire Dutch population (n=15.3 million individuals) and (2) three-year sample data (n=1152 individuals). Our findings indicate that switching rates strongly decrease with age. For example, in 2009, consumers aged 25-44 switched 10 times more than consumers aged 75 or older. Another finding is that switching rates decrease as the predicted health care expenses increase. Although healthy consumers switch twice as much as unhealthy consumers, this difference becomes much smaller after adjusting for age. We conclude that our findings can be explained by higher perceived switching costs by elderly consumers than by young consumers. Consequently, insurers have low incentives to act as quality-conscious purchasers of care for the elderly consumers. Therefore, strategies should be developed to increase the choice of insurer of elderly consumers. PMID:26173559

  9. Changing predictors of self-rated health: Disentangling age and cohort effects.

    PubMed

    Spuling, Svenja M; Wurm, Susanne; Tesch-Römer, Clemens; Huxhold, Oliver

    2015-06-01

    Previous studies have shown that some predictors of self-rated health (SRH) become more important with age, while others become less important. Although based on cross-sectional data, these findings are often interpreted as age-related changes in evaluation criteria. However, results could be due to cohort effects as well. We attempted to disentangle age and cohort effects by combining and comparing cross-sectional and longitudinal data from a large-scale longitudinal survey. The sample consisted of 2,982 community-dwelling participants from 2 measurement occasions of the German Ageing Survey ages 40-81 years at baseline. Multigroup latent regression models were used to examine whether associations between various predictors and SRH differed between age groups and whether they changed over time. Comparisons of cross-sectional age differences in SRH-predictor associations and longitudinal age changes in the same associations allow the identification of cohort effects. Number of chronic conditions showed a constant negative association with SRH independently of age and cohort. In contrast, the association between SRH and all other predictors (physical functioning, exercise, life satisfaction, depressive symptoms, and positive affect) changed longitudinally, pointing to an age effect. Prediction of SRH by depressive symptoms and positive affect showed an additional cohort effect: The negative associations between depressive symptoms and SRH and the positive associations between positive affect and SRH were stronger among younger cohorts. The findings provide not only longitudinal support for previous cross-sectional studies, but also show the impact of historical change: Emotional facets of psychological well-being increase in relevance for SRH across cohorts.

  10. Age influences the relation between subjective valence ratings and emotional word use during autobiographical memory retrieval.

    PubMed

    Ford, Jaclyn H; DiGirolamo, Marissa A; Kensinger, Elizabeth A

    2016-09-01

    Recent research reveals an age-related increase in positive autobiographical memory retrieval using a number of positivity measures, including valence ratings and positive word use. It is currently unclear whether the positivity shift in each of these measures co-occurs, or if age uniquely influences multiple components of autobiographical memory retrieval. The current study examined the correspondence between valence ratings and emotional word use in young and older adults' autobiographical memories. Positive word use in narratives was associated with valence ratings only in young adults' narratives. Older adults' narratives contained a consistent level of positive word use regardless of valence rating, suggesting that positive words and concepts may be chronically accessible to older adults during memory retrieval, regardless of subjective valence. Although a relation between negative word use in narratives and negative valence ratings was apparent in both young and older adults, it was stronger in older adults' narratives. These findings confirm that older adults do vary their word use in accordance with subjective valence, but they do so in a way that is different from young adults. The results also point to a potential dissociation between age-related changes in subjective valence and in positive word use. PMID:26274398

  11. Occurence and implications of radiation dose-rate effects for material aging studies

    NASA Astrophysics Data System (ADS)

    Gillen, Kenneth T.; Clough, Roger L.

    A number of commercial cable materials, including ethylene propylene rubber and crosslinked polyolefin insulations and chloroprene and chlorosulfonated polyethylene jackets have been radiation aged in air and nitrogen at radiation dose rates ranging from approximately 10 3 to 10 6{rad}/{hr}. Material degradation was followed using ultimate tensile properties (elongation and tensile strength), swelling measurements and infrared spectroscopy. The tensile results indicate that in air environments radiation dose rate effects are important for all four materials, with more mechanical damage occurring as the dose rate is lowered. These results are interpreted as coming from a competition between crosslinking and oxidative scission in which scission becomes more important as the dose rate is lowered. The swelling results offer direct evidence in support of this interpretation. In addition the infrared results show increased carbonyl content at lower dose rates, also indicative of increased oxidation. The conclusions of this study have important implications for the qualification of elastomeric materials for nuclear applications, since they clearly indicate that the mechanism of degradation is quite different (and the amount usually more severe) under low dose rate exposures compared to the mechanism occurring under the high dose rate exposures normally utilized for stimulating the natural aging.

  12. Cosmogenic in situ production of radionuclides: Exposure ages and erosion rates

    NASA Astrophysics Data System (ADS)

    Heisinger, B.; Nolte, E.

    2000-10-01

    Experimental data for the cosmogenic in situ production of radionuclides and its depth dependence are used for two applications, the determination of exposure ages and of erosion rates. Concentrations of the long-lived radionuclides 10Be, 14C and 26Al in quartz are presented as function of exposure age, depth before exposure and erosion rate after exposure. It is shown that the cosmogenic production before exposure can introduce important corrections to the representation without consideration of pre-exposure production. Depth profiles of 10Be, 14C and 26Al in quartz and sulfur, of 36Cl in K 2O, CaCO 3, granite and concrete and of 53Mn in Fe 2O 3 are given as function of erosion rate. Consequences to determinations of neutron fluences in Hiroshima are discussed.

  13. 40 CFR 75.12 - Specific provisions for monitoring NOX emission rate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Specific provisions for monitoring NOX... provisions for monitoring NOX emission rate. (a) Coal-fired units, gas-fired nonpeaking units or oil-fired... for a NOX continuous emission monitoring system (CEMS) for each affected coal-fired unit,...

  14. 40 CFR 75.12 - Specific provisions for monitoring NOX emission rate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Specific provisions for monitoring NOX... provisions for monitoring NOX emission rate. (a) Coal-fired units, gas-fired nonpeaking units or oil-fired... for a NOX continuous emission monitoring system (CEMS) for each affected coal-fired unit,...

  15. 40 CFR 75.12 - Specific provisions for monitoring NOX emission rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Specific provisions for monitoring NOX... provisions for monitoring NOX emission rate. (a) Coal-fired units, gas-fired nonpeaking units or oil-fired... for a NOX continuous emission monitoring system (CEMS) for each affected coal-fired unit,...

  16. 42 CFR 412.328 - Determining and updating the hospital-specific rate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Determining and updating the hospital-specific rate... AND HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Inpatient Hospital Capital Costs Determination of Transition Period...

  17. Trimester-Specific Gestational Weight Gain and Infant Size for Gestational Age

    PubMed Central

    Sridhar, Sneha B.; Xu, Fei; Hedderson, Monique M.

    2016-01-01

    Gestational weight gain is known to influence fetal growth. However, it is unclear whether the associations between gestational weight gain and fetal growth vary by trimester. In a diverse cohort of 8,977 women who delivered a singleton between 2011 and 2013, we evaluated the associations between trimester-specific gestational weight gain and infant size for gestational age. Gestational weight gain was categorized per the 2009 Institute of Medicine (IOM) recommendations; meeting the recommendations was the referent. Large for gestational age and small for gestational age were defined as birthweight > 90th percentile or <10th percentile, respectively, based on a national reference standard birthweight distribution. Logistic regression models estimated the odds of having a large or small for gestational age versus an appropriate for gestational age infant. Only gestational weight gain exceeding the IOM recommendations in the 2nd and 3rd trimesters independently increased the odds of delivering a large for gestational age infant (Odds Ratio (95% Confidence Interval): 1st: 1.17 [0.94, 1.44], 2nd: 1.47 [1.13, 1.92], 3rd: 1.70 [1.30, 2.22]). Gestational weight gain below the IOM recommendations increased the likelihood of having a small for gestational age infant in the 2nd trimester only (1.76 [1.23, 2.52]). There was effect modification, and gestational weight gain below the IOM recommendations increased the likelihood of having a small for gestational age infant in the 2nd trimester and only among women with a pre-pregnancy body mass index from 18.5–24.9 kg/m2 (2.06 [1.35, 3.15]). These findings indicate that gestational weight gain during the 2nd and 3rd trimesters is more strongly associated with infant growth. Interventions to achieve appropriate gestational weight gain may optimize infant size at birth. PMID:27442137

  18. Age-specific mortality trends in France and Italy since 1900: period and cohort effects.

    PubMed

    Caselli, G; Vallin, J; Vaupel, J W; Yashin, A

    1987-11-01

    The age/sex-specific mortality trends of France and Italy were studied over the 1899-1979 period in as much detail as possible in an effort to distinguish between cohort effects and those related to period changes. Complete series of mortality data by individual years of age and calendar years were available from 1869 to 1979 for Italy and from 1899 to 1982 for France. For both countries, these data include the military and civil deaths not registered in vital statistics during the war periods. They cover each national territory as defined by its present boundaries. The graphical representation method of mortality surfaces, elaborated by Vaupel, Gambill, and Yashin (1985), was adopted. The age/sex-specific mortality patterns of France and Italy have not followed the same trends, and the differences observed today are not those of 100 years ago. The mean death probabilities for the 1975-79 period were used to illustrate the age-specific patterns of mortality. Although infant mortality was higher in Italy than in France, the death probabilities at ages 1-15 for both sexes were roughly the same for both countries. At ages 15-23, they were much higher in France than in Italy, and they remained considerably higher in France up to age 55. From then on, the sexes differ: for males, the 2 countries showed similar patterns, whereas for females the probabilities were noticeably higher for France. The situation was very different for both countries at the beginning of the century. For both sexes, higher mortality was observed in Italy not only during infancy but throughout childhood and the adolescent years up to age 15. The 2 countries showed similar patterns from 15-25. Above age 25, the 2 countries had similar patterns for females, whereas male mortality was higher in France right up to the old age groups. Such differences in the age-specific mortality trends depend in part on a different development of health and social conditions but also may be due to factors concerning

  19. Mother-child reminiscing and autobiographical memory specificity among preschool-age children.

    PubMed

    Valentino, Kristin; Nuttall, Amy K; Comas, Michelle; McDonnell, Christina G; Piper, Brianna; Thomas, Taylor E; Fanuele, Suzanne

    2014-04-01

    Overgeneral memory (OGM) refers to difficulty in retrieving specific autobiographical memories. The tendency to be overgeneral in autobiographical memory recall is more commonly observed among individuals with emotional disorders compared with those without. Despite significant advances in theory and identification of mechanisms that underlie the etiology of OGM, there has been little integration between normative research on the development of autobiographical memory and research on OGM. Informed by a developmental psychopathology perspective and drawing on normative developmental research on the social construction of autobiographical memory, the current investigation examined whether the elaborative quantity and elaborative quality of maternal reminiscing are predictive of preschool-age children's autobiographical memory specificity. Additionally, this investigation tested whether children's positive self-representations may explain these hypothesized associations. Participants consisted of 95 mother-child dyads. Children's ages ranged between 3.5 and 6 years, and the sample was predominantly low income and of minority race/ethnicity. Dyads participated in a joint reminiscing task about 4 past events, and children participated in assessments of autobiographical memory specificity and self-representations. Results indicated that the elaborative quality, defined by maternal-sensitive guidance and emotional narrative coherence, but not the elaborative quantity, of maternal reminiscing style was significantly associated with children's autobiographical memory specificity. Additionally, there was support for an indirect pathway between maternal reminiscing quality and child memory specificity through children's positive self-representations. Directions for future research are discussed, and potential clinical implications are addressed.

  20. Age-Specific Peculiarities of Modulation of Blood Aldo-Keto Reductase Isoenzyme Spectrum.

    PubMed

    Davydov, V V

    2015-12-01

    The aldo-keto reductase spectrum of the blood was studied at different stages of ontogeny to elucidate the role of reduction pathway in utilization of the carbonyl products of free radical oxidation in modulation of organism sensitivity to the damaging effect of stress during ontogeny. The studies revealed the age-specific changes in aldo-keto reductase spectrum in the blood. An analogy of the aldo-keto reductase spectrum structure in animals of early maturity and in old rats was found. The appearance of age specificity of the aldo-keto reductase spectrum in the blood creates metabolic prerequisites for changes in the efficiency of utilization of carbonyl products of free radical oxidation via their reductive transformation.

  1. [Age-specific effects at the beginning of in-/out-/day patient welfare measures].

    PubMed

    Rücker, Stefan; Büttner, Peter; Petermann, Ulrike; Petermann, Franz

    2014-01-01

    The study presented examines age-specific differences in emotional and behaviour problems as well as resources at the beginning of in-, out- and day-patient youth welfare measures. Additionally, parenting-skills were investigated. A sample of N = 126 was divided by the median (10.1 years) thus leading to two groups: ages six to ten (version for parents) versus eleven to sixteen (self-completion). Children and adolescents were evaluated with the SDQ, parenting skills with the DEAPQ-EL-GS. Values of both groups were compared cross-sectionally with multivariate, one-factorial variance analysis. Parents of younger children achieve significantly better results for parenting-skills. Compared to the older ones, younger children show significantly greater behaviour problems. Younger children belong to the group especially affected in youth welfare measures. Therefore, measures should be specifically adapted for this group to reduce symptoms. PMID:24693805

  2. Age-related and site-specific changes in the pulpodentinal morphology of rat molars.

    PubMed

    Lovschall, H; Fejerskov, O; Josephsen, K

    2002-05-01

    The rat molars are frequently used as experimental models in endodontic research, but there is little systematic information available on the influence of age on the pulpodentinal organ in Wistar rat molars and it is often difficult to evaluate more subtle changes following experimental interventions. The aim here was to describe changes with age in first upper Wistar rat molars with specific reference to the pulpodentinal organ. Animals were perfused with glutaraldehyde at 19 days, 1, 3, 6, 8, 12, 16, or 24 months of age. First upper molars from 56 animals were demineralized in EDTA, embedded in Epon, and processed for light and transmission electron microscopy. Substantial variation in the structure of the dentine and odontoblasts was observed within the root canals and the coronal pulp chamber. In general, odontoblasts changed from a tall, columnar morphology in the coronal pulp chamber to a more cuboidal or flattened shape near the apex, particularly towards the interradicular space. Secondary dentine formation was more pronounced along the mesial aspect of the root chamber and corresponding to the bottom of fissures. Local tertiary dentine formation was layered in the upper pulp chamber, corresponding to occlusal attrition of the cusp. In several molars a local formation of irregular tertiary dentine was observed cervically in the mesial pulp chamber. After 1 year, a distinct protrusion of irregular dentine extended into the mesiocervical pulp, apparently corresponding to a denudation of cervical root dentine. Experimental pulp-capping studies frequently use first upper rat molars with perforations made through the mesial aspect of the crown; such perforations might be close to the irregular dentine in the mesiocervical region. In conclusion, this study identifies age-associated and regional changes of pulpodentinal morphology in first upper rat molars. Therefore, evaluation of morphological alterations following vital-pulp experiments should be done in

  3. An Atypical Age-Specific Pattern of Hepatocellular Carcinoma in Peru: A Threat for Andean Populations

    PubMed Central

    Loli, Sebastian; Moura, Julien; Zimic, Mirko; Deharo, Eric; Ruiz, Eloy

    2013-01-01

    Background In South America, the highest incidence of primary liver cancer is observed in Peru. However, national estimations on hepatocellular carcinoma incidence and mortality are approximated using aggregated data from surrounding countries. Thus, there is a lack of tangible information from Peru that impairs an accurate description of the local incidence, presentation, and outcomes of hepatocellular carcinoma. The present study attempts to fill this gap and assesses the clinical epidemiology of hepatocellular carcinoma in this country. Methods A retrospective cohort study was conducted by analysing the medical charts of 1,541 patients with hepatocellular carcinoma admitted between 1997 and 2010 at the Peruvian national institute for cancer. The medical records including liver function, serologic status, and tumor pathology and stage were monitored. Statistical analyses were performed in order to characterize tumor presentation according to demographic features, risk factors, and regional origin. Results Surprisingly, the age distribution of the patient population displayed bimodality corresponding to two distinct age-based subpopulations. While an older group was in keeping with the age range observed for hepatocellular carcinoma around the world, a younger population displayed an abnormally juvenile mean age of 25.5 years old. In addition, each subpopulation displayed age-specific pathophysiological and clinical characteristics. Conclusions The analysis suggests two different age-specific natural histories of hepatocellular carcinoma in the Peruvian patient population. This otherwise unusual tumor process that is ongoing in younger patients leads to the hypothesis that there may be a Peru-endemic risk factor driving hepatocarcinogenesis in the local population. PMID:23840771

  4. Age-related differences in celiac disease: Specific characteristics of adult presentation

    PubMed Central

    Vivas, Santiago; Vaquero, Luis; Rodríguez-Martín, Laura; Caminero, Alberto

    2015-01-01

    Celiac disease may appear both in early childhood and in elderly subjects. Current knowledge of the disease has revealed some differences associated to the age of presentation. Furthermore, monitoring and prognosis of celiac subjects can vary depending on the pediatric or adult stage. The main objective of this review is to provide guidance for the adult diagnostic and follow-up processes, which must be tailored specifically for adults and be different from pediatric patients. PMID:26558154

  5. Brain site-specific proteome changes in aging-related dementia

    PubMed Central

    Manavalan, Arulmani; Mishra, Manisha; Feng, Lin; Sze, Siu Kwan; Akatsu, Hiroyasu; Heese, Klaus

    2013-01-01

    This study is aimed at gaining insights into the brain site-specific proteomic senescence signature while comparing physiologically aged brains with aging-related dementia brains (for example, Alzheimer's disease (AD)). Our study of proteomic differences within the hippocampus (Hp), parietal cortex (pCx) and cerebellum (Cb) could provide conceptual insights into the molecular mechanisms involved in aging-related neurodegeneration. Using an isobaric tag for relative and absolute quantitation (iTRAQ)-based two-dimensional liquid chromatography coupled with tandem mass spectrometry (2D-LC-MS/MS) brain site-specific proteomic strategy, we identified 950 proteins in the Hp, pCx and Cb of AD brains. Of these proteins, 31 were significantly altered. Most of the differentially regulated proteins are involved in molecular transport, nervous system development, synaptic plasticity and apoptosis. Particularly, proteins such as Gelsolin (GSN), Tenascin-R (TNR) and AHNAK could potentially act as novel biomarkers of aging-related neurodegeneration. Importantly, our Ingenuity Pathway Analysis (IPA)-based network analysis further revealed ubiquitin C (UBC) as a pivotal protein to interact with diverse AD-associated pathophysiological molecular factors and suggests the reduced ubiquitin proteasome degradation system (UPS) as one of the causative factors of AD. PMID:24008896

  6. Age, differential growth and mortality rates in unexploited populations of Florida gar, an apex predator in the Florida Everglades

    USGS Publications Warehouse

    Murie, D.J.; Parkyn, D.C.; Nico, L.G.; Herod, J.J.; Loftus, W.F.

    2009-01-01

    Florida gar, Lepisosteus platyrhincus DeKay, were sampled in two canal systems in south Florida during 2000-2001 to estimate age, growth and mortality as part of the Everglades ecosystem-restoration effort. Tamiami (C-4) and L-31W canal systems had direct connections to natural wetlands of the Everglades and harboured large Florida gar populations. Of 476 fish aged, maximum ages were 19 and 10years for females and males, respectively. Maximum sizes were also larger for females compared with males (817 vs 602 mm total length). Overall, female Florida gar from both Tamiami and L-31W were larger at age than males from L-31W that, in turn, were larger at any given age than males from Tamiami. Females also had lower rates of annual mortality (Z = 0.21) than males from L-31W (Z = 0.31) or males from Tamiami (Z = 0.54). As a large and long-lived apex predator in the Everglades, Florida gar may structure lower trophic levels. Regional- and sex-specific population parameters for Florida gar will contribute to the simulation models designed to evaluate Everglades restoration alternatives. ?? 2009 Blackwell Publishing Ltd.

  7. Crustal subsidence rate off Hawaii determined from 234U/238U ages of drowned coral reefs

    USGS Publications Warehouse

    Ludwig, K. R.; Szabo, B. J.; Moore, J.G.; Simmons, K.R.

    1991-01-01

    A series of submerged coral reefs off northwestern Hawaii was formed during (largely glacial) intervals when the rate of local sea-level rise was less than the maximum upward growth rate of the reefs. Mass-spectrometric 234U/238U ages for samples from six such reefs range from 17 to 475 ka and indicate that this part of the Hawaiian Ridge has been subsiding at a roughly uniform rate of 2.6 mm/yr for the past 475 ka. The 234U/238U ages are in general agreement with model ages of reef drowning (based on estimates of paleo-sea-level stands derived from oxygen-isotope ratios of deep-sea sediments), but there are disagreements in detail. The high attainable precision (??10 ka or better on samples younger than ~800 ka), large applicable age range, relative robustness against open-system behavior, and ease of analysis for this technique hold great promise for future applications of dating of 50-1000 ka coral. -Authors

  8. The effects of low dose rate irradiation and thermal aging on reactor structural alloys

    NASA Astrophysics Data System (ADS)

    Allen, T. R.; Trybus, C. L.; Cole, J. I.

    As part of the EBR-II reactor materials surveillance program, test samples of fifteen different alloys were placed into EBR-II in 1965. The surveillance (SURV) program was intended to determine property changes in reactor structural materials caused by irradiation and thermal aging. In this work, the effect of low dose rate (approximately 2 × 10 -8 dpa/s) irradiation at 380-410°C and long term thermal aging at 371°C on the properties of 20% cold worked 304 stainless steel, 420 stainless steel, Inconel X750, 304/308 stainless weld material, and 17-4 PH steel are evaluated. Doses of up to 6.8 dpa and thermal aging to 2994 days did not significantly affect the density of these alloys. The strength of 304 SS, X750, 17-4 PH, and 304/308 weld material increased with irradiation. In contrast, the strength of 420 stainless steel decreased with irradiation. Irradiation decreased the impact energy in both Inconel X750 and 17-4 PH steel. Thermal aging decreased the impact energy in 17-4 PH steel and increased the impact energy in Inconel X750. Tensile property comparisons of 304 SURV samples with 304 samples irradiated in EBR-II at a higher dose rate show that the higher dose rate samples had greater increases in strength and greater losses in ductility.

  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. Age-Stratified Treatment Response Rates in Hospitalized Patients with Clostridium difficile Infection Treated with Metronidazole

    PubMed Central

    Pham, Vy P.; Luce, Andrea M.; Ruppelt, Sara C.; Wei, Wenjing; Aitken, Samuel L.; Musick, William L.; Roux, Ryan K.

    2015-01-01

    Consensus on the optimal treatment of Clostridium difficile infection (CDI) is rapidly changing. Treatment with metronidazole has been associated with increased clinical failure rates; however, the reasons for this are unclear. The purpose of this study was to assess age-related treatment response rates in hospitalized patients with CDI treated with metronidazole. This was a retrospective, multicenter cohort study of hospitalized patients with CDI. Patients were assessed for refractory CDI, defined as persistent diarrhea after 7 days of metronidazole therapy, and stratified by age and clinical characteristics. A total of 242 individuals, aged 60 ± 18 years (Charlson comorbidity index, 3.8 ± 2.4; Horn's index, 1.7 ± 1.0) were included. One hundred twenty-eight patients (53%) had severe CDI. Seventy patients (29%) had refractory CDI, a percentage that increased from 22% to 28% and to 37% for patients aged less than 50 years, for patients from 50 to 70 years, and for patients aged >70 years, respectively (P = 0.05). In multivariate analysis, Horn's index (odds ratio [OR], 2.04; 95% confidence interval [CI], 1.50 to 2.77; P < 0.001), severe CDI (OR, 2.25; 95% CI, 1.15 to 4.41; P = 0.018), and continued use of antibiotics (OR, 2.65; 95% CI, 1.30 to 5.39; P = 0.0072) were identified as significant predictors of refractory CDI. Age was not identified as an independent risk factor for refractory CDI. Therefore, hospitalized elderly patients with CDI treated with metronidazole had increased refractory CDI rates likely due to increased underlying severity of illness, severity of CDI, and concomitant antibiotic use. These results may help identify patients that may benefit from alternative C. difficile treatments other than metronidazole. PMID:26195522

  11. Tendency for age-specific mortality with hypertension in the European Union from 1980 to 2011.

    PubMed

    Tao, Lichan; Pu, Cunying; Shen, Shutong; Fang, Hongyi; Wang, Xiuzhi; Xuan, Qinkao; Xiao, Junjie; Li, Xinli

    2015-01-01

    Tendency for mortality in hypertension has not been well-characterized in European Union (EU). Mortality data from 1980 to 2011 in EU were used to calculate age-standardized mortality rate (ASMR, per 100,000), annual percentage change (APC) and average annual percentage change (AAPC). The Joinpoint Regression Program was used to compare the changes in tendency. Mortality rates in the most recent year studied vary between different countries, with the highest rates observed in Slovakia men and Estonia women. A downward trend in ASMR was demonstrated over all age groups. Robust decreases in ASMR were observed for both men (1991-1994, APC = -13.54) and women (1996-1999, APC = -14.80) aged 55-65 years. The tendency of systolic blood pressure (SBP) from 1980 to 2009 was consistent with ASMR, and the largest decrease was observed among Belgium men and France women. In conclusion, SBP associated ASMR decreased significantly on an annual basis from 1980 to 2009 while a slight increase was observed after 2009. Discrepancies in ASMR from one country to another in EU are significant during last three decades. With a better understanding of the tendency of the prevalence of hypertension and its mortality, efforts will be made to improve awareness and help strict control of hypertension. PMID:25932090

  12. Tendency for age-specific mortality with hypertension in the European Union from 1980 to 2011

    PubMed Central

    Tao, Lichan; Pu, Cunying; Shen, Shutong; Fang, Hongyi; Wang, Xiuzhi; Xuan, Qinkao; Xiao, Junjie; Li, Xinli

    2015-01-01

    Tendency for mortality in hypertension has not been well-characterized in European Union (EU). Mortality data from 1980 to 2011 in EU were used to calculate age-standardized mortality rate (ASMR, per 100,000), annual percentage change (APC) and average annual percentage change (AAPC). The Joinpoint Regression Program was used to compare the changes in tendency. Mortality rates in the most recent year studied vary between different countries, with the highest rates observed in Slovakia men and Estonia women. A downward trend in ASMR was demonstrated over all age groups. Robust decreases in ASMR were observed for both men (1991-1994, APC = -13.54) and women (1996-1999, APC = -14.80) aged 55-65 years. The tendency of systolic blood pressure (SBP) from 1980 to 2009 was consistent with ASMR, and the largest decrease was observed among Belgium men and France women. In conclusion, SBP associated ASMR decreased significantly on an annual basis from 1980 to 2009 while a slight increase was observed after 2009. Discrepancies in ASMR from one country to another in EU are significant during last three decades. With a better understanding of the tendency of the prevalence of hypertension and its mortality, efforts will be made to improve awareness and help strict control of hypertension. PMID:25932090

  13. Tendency for age-specific mortality with hypertension in the European Union from 1980 to 2011.

    PubMed

    Tao, Lichan; Pu, Cunying; Shen, Shutong; Fang, Hongyi; Wang, Xiuzhi; Xuan, Qinkao; Xiao, Junjie; Li, Xinli

    2015-01-01

    Tendency for mortality in hypertension has not been well-characterized in European Union (EU). Mortality data from 1980 to 2011 in EU were used to calculate age-standardized mortality rate (ASMR, per 100,000), annual percentage change (APC) and average annual percentage change (AAPC). The Joinpoint Regression Program was used to compare the changes in tendency. Mortality rates in the most recent year studied vary between different countries, with the highest rates observed in Slovakia men and Estonia women. A downward trend in ASMR was demonstrated over all age groups. Robust decreases in ASMR were observed for both men (1991-1994, APC = -13.54) and women (1996-1999, APC = -14.80) aged 55-65 years. The tendency of systolic blood pressure (SBP) from 1980 to 2009 was consistent with ASMR, and the largest decrease was observed among Belgium men and France women. In conclusion, SBP associated ASMR decreased significantly on an annual basis from 1980 to 2009 while a slight increase was observed after 2009. Discrepancies in ASMR from one country to another in EU are significant during last three decades. With a better understanding of the tendency of the prevalence of hypertension and its mortality, efforts will be made to improve awareness and help strict control of hypertension.

  14. Maximising electricity production by controlling the biofilm specific growth rate in microbial fuel cells.

    PubMed

    Ledezma, Pablo; Greenman, John; Ieropoulos, Ioannis

    2012-08-01

    The aim of this work is to study the relationship between growth rate and electricity production in perfusion-electrode microbial fuel cells (MFCs), across a wide range of flow rates by co-measurement of electrical output and changes in population numbers by viable counts and optical density. The experiments hereby presented demonstrate, for the first time to the authors' knowledge, that the anodic biofilm specific growth rate can be determined and controlled in common with other loose matrix perfusion systems. Feeding with nutrient-limiting conditions at a critical flow rate (50.8 mL h(-1)) resulted in the first experimental determination of maximum specific growth rate μ(max) (19.8 day(-1)) for Shewanella spp. MFC biofilms, which is considerably higher than those predicted or assumed via mathematical modelling. It is also shown that, under carbon-energy limiting conditions there is a strong direct relationship between growth rate and electrical power output, with μ(max) coinciding with maximum electrical power production.

  15. Age differences in intercorrelations between regional cerebral metabolic rates for glucose

    SciTech Connect

    Horwitz, B.; Duara, R.; Rapoport, S.I.

    1986-01-01

    Patterns of cerebral metabolic intercorrelations were compared in the resting state in 15 healthy young men (ages 20 to 32 years) and 15 healthy elderly men (ages 64 to 83 years). Controlling for whole-brain glucose metabolism, partial correlation coefficients were determined between pairs of regional cerebral metabolic rates for glucose determined by positron emission tomography using (18F)fluorodeoxyglucose and obtained in 59 brain regions. Compared with the young men, the elderly men had fewer statistically significant correlations, with the most notable reductions observed between the parietal lobe regions, and between the parietal and frontal lobe regions. These results suggest that cerebral functional interactions are reduced in healthy elderly men.

  16. Association of suicide rates for elderly age bands with gender equality.

    PubMed

    Shah, Ajit

    2008-06-01

    A lower sex ratio (male to female) of elderly suicide rates in several Asian countries have been attributed to gender inequality on several parameters. The association of two proxy measures of gender equality (value of the gender empowerment measure and the gender-related development index) and the male to female sex ratio of suicide rates in the age bands 65-74 yr. and 75+ yr. was examined using multiple linear regression. The two proxy measures of gender equality did not account for significant variance in the male to female sex ratio of suicide rates in the age bands 65-74 yr. and 75+ yr. Association of gender equality with the male to female sex ratio of suicide rates requires further clarification in both cross-sectional studies across different countries and longitudinal studies within individual countries for all age bands. Such studies should, in addition to the GEM and the GDI, include other measures of gender equality including sex differences in educational attainment, income, poverty, housing, employment, access to healthcare and social welfare services, and urbanisation.

  17. Region-specific changes in mitochondrial D-loop in aged rat CNS.

    PubMed

    McInerny, Simone C; Brown, Amanda L; Smith, Doug W

    2009-05-01

    Impaired mitochondrial oxidative phosphorylation (OXPHOS) is considered a cause of aging. A reduction in mitochondrial DNA (mtDNA) replication and/or transcription may contribute to this OXPHOS diminution. Impairments in the displacement (D) loop, or non-coding, region of the mitochondrial genome, or accumulation of mtDNA mutations, may affect mtDNA replication and transcription. We determined the effects of age on the D-loop and on mtDNA deletion mutations in the spinal cord, medulla, midbrain, cerebellum, striatum, and cerebral cortex of Fischer 344 rats. D-loop, 7S DNA levels were reduced by 3-fold in striatum, 2.5-fold in cortex, and 2-fold in the spinal cord of older animals. We did not detect a population of mtDNA affected by the most prevalent known (ND4-containing) deletions, indicating they do not comprise a significant portion of total mtDNA. However, we detected an age-related and region-specific increase in the common deletion, which comprised 0.0003-0.0007% of total mtDNA. Mitochondrial genome copy number varied between regions, in addition to an overall 18% decrease with age across the whole brain. These results suggest the age-related decline in OXPHOS may be related to a reduction in D-loop function. PMID:19428453

  18. Memory impairment in aged primates is associated with region-specific network dysfunction

    PubMed Central

    Thomé, Alexander; Gray, Daniel T.; Erickson, Cynthia A.; Lipa, Peter; Barnes, Carol A.

    2015-01-01

    Age-related deficits in episodic memory result, in part, from declines in the integrity of medial temporal lobe structures, such as the hippocampus, but are not thought to be due to widespread loss of principal neurons. Studies in rodents suggest, however, that inhibitory interneurons may be particularly vulnerable in advanced age. Optimal encoding and retrieval of information depend on a balance of excitatory and inhibitory transmission. It is not known whether a disruption of this balance is observed in aging nonhuman primates, and whether such changes affect network function and behavior. To examine this question we combine large scale electrophysiological recordings with cell type-specific imaging in the medial temporal lobe of cognitively-assessed, aged rhesus macaques. We found that neuron excitability in hippocampal region CA3 is negatively correlated with the density of the somatostatin-expressing inhibitory interneurons in the vicinity of the recording electrodes in stratum oriens. By contrast, no hyperexcitability or interneuron loss was observed in the perirhinal cortex of these aged, memory-impaired monkeys. These data provide a link, for the first time, between selective increases in principal cell excitability and declines in a molecularly-defined population of interneurons that regulate network inhibition. PMID:26503764

  19. Specific ablation of Nampt in adult neural stem cells recapitulates their functional defects during aging

    PubMed Central

    Stein, Liana R; Imai, Shin-ichiro

    2014-01-01

    Neural stem/progenitor cell (NSPC) proliferation and self-renewal, as well as insult-induced differentiation, decrease markedly with age. The molecular mechanisms responsible for these declines remain unclear. Here, we show that levels of NAD+ and nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme in mammalian NAD+ biosynthesis, decrease with age in the hippocampus. Ablation of Nampt in adult NSPCs reduced their pool and proliferation in vivo. The decrease in the NSPC pool during aging can be rescued by enhancing hippocampal NAD+ levels. Nampt is the main source of NSPC NAD+ levels and required for G1/S progression of the NSPC cell cycle. Nampt is also critical in oligodendrocytic lineage fate decisions through a mechanism mediated redundantly by Sirt1 and Sirt2. Ablation of Nampt in the adult NSPCs in vivo reduced NSPC-mediated oligodendrogenesis upon insult. These phenotypes recapitulate defects in NSPCs during aging, giving rise to the possibility that Nampt-mediated NAD+ biosynthesis is a mediator of age-associated functional declines in NSPCs. PMID:24811750

  20. Impact of Age and Myopia on the Rate of Visual Field Progression in Glaucoma Patients

    PubMed Central

    Park, Hae-Young Lopilly; Hong, Kyung Euy; Park, Chan Kee

    2016-01-01

    Abstract Myopia is rapidly increasing in young populations and patients with glaucoma associated with myopia are reported to be young aged in East Asia. These young patients have a longer life expectancy, which increases their risk of end-of-life visual disabilities. There is a need to understand the clinical course of myopic glaucoma patients, which may be important for the care of these myopic populations. In this study, we evaluated the relationship between the age at presentation and the rate of glaucoma progression in the visual field (VF) according to the presence of myopia. The study was conducted as a prospective observational study including 179 patients with open-angle glaucoma who had undergone at least 5 VF examinations with a follow-up of at least 5 years. The progression rate of the mean deviation (MD) and the pattern standard deviation (PSD) are expressed as change in decibels (dB) per year. The slopes of the MD and PSD were calculated by linear regression analyses. Factors related to the slope of VF MD changes were analyzed with correlation and regression analyses. The slope of the linear fit line plotted against age at presentation and the rate of change in the VF MD was −0.026 (P < 0.001) in the myopic group and −0.008 (P = 0.167) in the nonmyopic group; the relationship was more prominent in the myopic group than the nonmyopic group. In the myopic group, age (β = −0.417; 95% confidence intervals (CI), −0.651 to −0.200; P = 0.050) and baseline untreated intraocular pressure (β = −0.179; 95% CI, −0.331 to −0.028; P = 0.022) were significantly related to the rate of change in the MD, which was only the presence of disc hemorrhage (β = −0.335; 95% CI, −0.568 to −0.018; P = 0.022) in the nonmyopic group. Age at presentation was significantly related to the rate of change in the VF in glaucomatous eyes with myopia compared to eyes without myopia. Older age was significantly related to the rate of

  1. Age-Specific Effects of Voluntary Exercise on Memory and the Older Brain

    PubMed Central

    Siette, Joyce; Westbrook, R. Frederick; Cotman, Carl; Sidhu, Kuldip; Zhu, Wanlin; Sachdev, Perminder; Valenzuela, Michael J.

    2014-01-01

    Background Physical exercise in early adulthood and mid-life improves cognitive function and enhances brain plasticity, but the effects of commencing exercise in late adulthood are not well-understood. Method We investigated the effects of voluntary exercise in the restoration of place recognition memory in aged rats and examined hippocampal changes of synaptic density and neurogenesis. Results We found a highly selective age-related deficit in place recognition memory that is stable across retest sessions and correlates strongly with loss of hippocampal synapses. Additionally, 12 weeks of voluntary running at 20 months of age removed the deficit in the hippocampally dependent place recognition memory. Voluntary running restored presynaptic density in the dentate gyrus and CA3 hippocampal subregions in aged rats to levels beyond those observed in younger animals, in which exercise had no functional or synaptic effects. By contrast, hippocampal neurogenesis, a possible memory-related mechanism, increased in both young and aged rats after physical exercise but was not linked with performance in the place recognition task. We used graph-based network analysis based on synaptic covariance patterns to characterize efficient intrahippocampal connectivity. This analysis revealed that voluntary running completely reverses the profound degradation of hippocampal network efficiency that accompanies sedentary aging. Furthermore, at an individual animal level, both overall hippocampal presynaptic density and subregional connectivity independently contribute to prediction of successful place recognition memory performance. Conclusions Our findings emphasize the unique synaptic effects of exercise on the aged brain and their specific relevance to a hippocampally based memory system for place recognition. PMID:22795967

  2. Adjuvant-induced Human Monocyte Secretome Profiles Reveal Adjuvant- and Age-specific Protein Signatures.

    PubMed

    Oh, Djin-Ye; Dowling, David J; Ahmed, Saima; Choi, Hyungwon; Brightman, Spencer; Bergelson, Ilana; Berger, Sebastian T; Sauld, John F; Pettengill, Matthew; Kho, Alvin T; Pollack, Henry J; Steen, Hanno; Levy, Ofer

    2016-06-01

    Adjuvants boost vaccine responses, enhancing protective immunity against infections that are most common among the very young. Many adjuvants activate innate immunity, some via Toll-Like Receptors (TLRs), whose activities varies with age. Accordingly, characterization of age-specific adjuvant-induced immune responses may inform rational adjuvant design targeting vulnerable populations. In this study, we employed proteomics to characterize the adjuvant-induced changes of secretomes from human newborn and adult monocytes in response to Alum, the most commonly used adjuvant in licensed vaccines; Monophosphoryl Lipid A (MPLA), a TLR4-activating adjuvant component of a licensed Human Papilloma Virus vaccine; and R848 an imidazoquinoline TLR7/8 agonist that is a candidate adjuvant for early life vaccines. Monocytes were incubated in vitro for 24 h with vehicle, Alum, MPLA, or R848 and supernatants collected for proteomic analysis employing liquid chromatography-mass spectrometry (LC-MS) (data available via ProteomeXchange, ID PXD003534). 1894 non-redundant proteins were identified, of which ∼30 - 40% were common to all treatment conditions and ∼5% were treatment-specific. Adjuvant-stimulated secretome profiles, as identified by cluster analyses of over-represented proteins, varied with age and adjuvant type. Adjuvants, especially Alum, activated multiple innate immune pathways as assessed by functional enrichment analyses. Release of lactoferrin, pentraxin 3, and matrix metalloproteinase-9 was confirmed in newborn and adult whole blood and blood monocytes stimulated with adjuvants alone or adjuvanted licensed vaccines with distinct clinical reactogenicity profiles. MPLA-induced adult monocyte secretome profiles correlated in silico with transcriptome profiles induced in adults immunized with the MPLA-adjuvanted RTS,S malaria vaccine (Mosquirix™). Overall, adjuvants such as Alum, MPLA and R848 give rise to distinct and age-specific monocyte secretome profiles

  3. Adjuvant-induced Human Monocyte Secretome Profiles Reveal Adjuvant- and Age-specific Protein Signatures*

    PubMed Central

    Oh, Djin-Ye; Dowling, David J.; Ahmed, Saima; Choi, Hyungwon; Brightman, Spencer; Bergelson, Ilana; Berger, Sebastian T.; Sauld, John F.; Pettengill, Matthew; Kho, Alvin T.; Pollack, Henry J.; Steen, Hanno; Levy, Ofer

    2016-01-01

    Adjuvants boost vaccine responses, enhancing protective immunity against infections that are most common among the very young. Many adjuvants activate innate immunity, some via Toll-Like Receptors (TLRs), whose activities varies with age. Accordingly, characterization of age-specific adjuvant-induced immune responses may inform rational adjuvant design targeting vulnerable populations. In this study, we employed proteomics to characterize the adjuvant-induced changes of secretomes from human newborn and adult monocytes in response to Alum, the most commonly used adjuvant in licensed vaccines; Monophosphoryl Lipid A (MPLA), a TLR4-activating adjuvant component of a licensed Human Papilloma Virus vaccine; and R848 an imidazoquinoline TLR7/8 agonist that is a candidate adjuvant for early life vaccines. Monocytes were incubated in vitro for 24 h with vehicle, Alum, MPLA, or R848 and supernatants collected for proteomic analysis employing liquid chromatography-mass spectrometry (LC-MS) (data available via ProteomeXchange, ID PXD003534). 1894 non-redundant proteins were identified, of which ∼30 - 40% were common to all treatment conditions and ∼5% were treatment-specific. Adjuvant-stimulated secretome profiles, as identified by cluster analyses of over-represented proteins, varied with age and adjuvant type. Adjuvants, especially Alum, activated multiple innate immune pathways as assessed by functional enrichment analyses. Release of lactoferrin, pentraxin 3, and matrix metalloproteinase-9 was confirmed in newborn and adult whole blood and blood monocytes stimulated with adjuvants alone or adjuvanted licensed vaccines with distinct clinical reactogenicity profiles. MPLA-induced adult monocyte secretome profiles correlated in silico with transcriptome profiles induced in adults immunized with the MPLA-adjuvanted RTS,S malaria vaccine (Mosquirix™). Overall, adjuvants such as Alum, MPLA and R848 give rise to distinct and age-specific monocyte secretome profiles

  4. Effects of safety warnings on prescription rates of cough and cold medicines in children below 2 years of age

    PubMed Central

    Sen, E Fatma; Verhamme, Katia M C; Felisi, Mariagrazia; 't Jong, Geert W; Giaquinto, Carlo; Picelli, Gino; Ceci, Adriana; Sturkenboom, Miriam C J M

    2011-01-01

    AIM The aim of the study was to assess the influence of national and international warnings on the prescription rates of cough and cold medicines (CCMs) in the youngest children (<2 years) in the Netherlands and Italy. METHODS Analysis of outpatient electronic medical records of children <2 years in Italy and the Netherlands was carried out. Age and country specific prescription prevalence rates were calculated for the period 2005–08. Comparisons of prescription rates in 2005 (pre) and 2008 (post) warnings were done by means of a chi-square test. RESULTS The cohort consisted of 99 176 children <2 years of age. After international warnings, overall prescription rates for CCMs decreased slightly from 83 to 77/1000 person years (P = 0.05) in Italy and increased in the Netherlands from 74 to 92/1000 children per year. Despite the international warnings, prescription rates for nasal sympathomimetics and opium alkaloids increased in the Netherlands (P < 0.01). In Italy a significant decrease in the prescription rates of opium alkaloids and other cough suppressants (P < 0.01) was observed, and also a significant reduction in use of combinations of nasal sympathomimetics. CONCLUSION Despite the international safety warnings and negative benefit-risk profiles, prescription rates of cough and cold medicines remain substantial and were hardly affected by the warnings, especially in the Netherlands where no warning was issued. The hazards of use of these medicines in young children should be explicitly stipulated by the European Medicines Agency and all national agencies, in order to increase awareness amongst physicians and caretakers and reduce heterogeneity across the EU. PMID:21564162

  5. ERK1 nucleocytoplasmic shuttling rate depends on specific N-terminal aminoacids

    SciTech Connect

    Marchi, Matilde; Pancrazi, Laura; Maffei, Margherita; Ratto, G. Michele; Costa, Mario

    2010-07-23

    Despite ERK1 and ERK2 were considered interchangeable isoforms for a long time, their roles are now emerging as only partially overlapping. We recently reported that the nucleocytoplasmic trafficking of GFP-tagged ERK1 is slower than that of ERK2, this difference being caused by a unique domain of ERK1 located at its N-terminus (ERK1-Nt). In the present report we further investigated this issue by asking which were the specific aminoacids involved in such process. By photobleaching strategy, we demonstrated that ERK1-Nt is a domain capable to slow down the nucleocytoplasmic shuttling rate even of a small cargo protein. ERK1-Nt was then dissected into three regions as follows: 1 (aa 1-9), 2 (aa 10-29) and 3, (aa 30-39) that were deleted or mutated at specific sites. Dynamic imaging assessment of the role played by each region in determining the shuttling rate revealed that: region 1 has no significant role, region 2 and specific aminoacids of region 3 (V{sub 31}, K{sub 33,} P{sub 36}) are critical, but singularly do not totally account for the difference in the shuttling rate between ERK1 and 2. Finally, we demonstrated that the nucleocytoplasmic shuttling rate of a passively diffusing protein (mRED) is inversely related to ERK1-Nt-GFP concentrations inside the cell, thus suggesting that ERK1-Nt-GFP occupies the nuclear pore perhaps because of an important affinity of ERK1-Nt for nucleoporins. In conclusion, ERK1-Nt is a domain able per se to confer a slower shuttling rate to a cargo protein. Specific regions within this domain were identified as responsible for this biophysical property.

  6. Gestational Age-specific Cut-off Values Are Needed for Diagnosis of Subclinical Hypothyroidism in Early Pregnancy.

    PubMed

    Kim, Hye Sung; Kim, Byoung Jae; Oh, Sohee; Lee, Da Young; Hwang, Kyu Ri; Jeon, Hye Won; Lee, Seung Mi

    2015-09-01

    During the first trimester of pregnancy, thyroid-stimulating hormone (TSH) >2.5 mIU/L has been suggested as the universal criterion for subclinical hypothyroidism. However, TSH levels change continuously during pregnancy, even in the first trimester. Therefore the use of a fixed cut-off value for TSH may result in a different diagnosis rate of subclinical hypothyroidism according to gestational age. The objective of this study was to obtain the normal reference range of TSH during the first trimester in Korean gravida and to determine the diagnosis rate of subclinical hypothyroidism using the fixed cut-off value (TSH >2.5 mIU/L). The study population consisted of pregnant women who were measured for TSH during the first trimester of pregnancy (n=492) and nonpregnant women (n=984). Median concentration of TSH in pregnant women was lower than in non-pregnant women. There was a continuous decrease of median TSH concentration during the first trimester of pregnancy (median TSH concentration: 1.82 mIU/L for 3+0 to 6+6 weeks; 1.53 mIU/L for 7+0 to 7+6 weeks; and 1.05 mIU/L for 8+0 to 13+6 weeks). Using the fixed cut-off value of TSH >2.5 mIU/L, the diagnosis rate of subclinical hypothyroidism decreased significantly according to the gestational age (GA) at TSH (25% in 3+0 to 6+6 weeks, 13% in 7+0 to 7+6 weeks, and 9% for 8+0 to 13+6 weeks, P<0.001), whereas the diagnosis rate was 5% in all GA with the use of a GA-specific cut-off value (P=0.995). Therefore, GA-specific criteria might be more appropriate for the diagnosis of subclinical hypothyroidism.

  7. Protein synthesis rates in rat brain regions and subcellular fractions during aging

    SciTech Connect

    Avola, R.; Condorelli, D.F.; Ragusa, N.; Renis, M.; Alberghina, M.; Giuffrida Stella, A.M.; Lajtha, A.

    1988-04-01

    In vivo protein synthesis rates in various brain regions (cerebral cortex, cerebellum, hippocampus, hypothalamus, and striatum) of 4-, 12-, and 24-month-old rats were examined after injection of a flooding dose of labeled valine. The incorporation of labeled valine into proteins of mitochondrial, microsomal, and cytosolic fractions from cerebral cortex and cerebellum was also measured. At all ages examined, the incorporation rate was 0.5% per hour in cerebral cortex, cerebellum, hippocampus, and hypothalamus and 0.4% per hour in striatum. Of the subcellular fractions examined, the microsomal proteins were synthesized at the highest rate, followed by cytosolic and mitochondrial proteins. The results obtained indicate that the average synthesis rate of proteins in the various brain regions and subcellular fractions examined is fairly constant and is not significantly altered in the 4 to 24-month period of life of rats.

  8. Apolipoprotein E and Alzheimer disease: Genotype-specific risks by age and sex

    SciTech Connect

    Bickeboeller, H. |; Babron, M.C.; Clerget-Darpoux, F.

    1997-02-01

    The distribution of apolipoprotein E (APOE) genotypes as a function of age and sex has been examined in a French population of 417 Alzheimer disease (AD) patients and 1,030 control subjects. When compared to the APOE {epsilon}3 allele, an increased risk associated with the APOE {epsilon}4 allele (odds ratio [OR] [{epsilon}4] = 2.7 with 95% confidence interval [CI] = 2.0-3.6; P < .001) and a protective effect of the APOE {epsilon}2 allele (OR[{epsilon}2] = 0.5 with 95% CI = 0.3-0.98; P = .012) were retrieved. An effect of the {epsilon}4 allele dosage on susceptibility was confirmed (OR[{epsilon}4/{epsilon}4] vs. the {epsilon}3/{epsilon}3 genotype = 11.2 [95% CI = 4.0-31.6]; OR[{epsilon}3/{epsilon}4] vs. the {epsilon}3/{epsilon}3 genotype = 2.2 [95% Cl = 1.5-3.5]). The frequency of the {epsilon}4 allele was lower in male cases than in female cases, but, since a similar difference was found in controls, this does not lead to a difference in OR between sex. ORs for the {epsilon}4 allele versus the {epsilon}3 allele, OR({epsilon}4), were not equal in all age classes: OR({epsilon}4) in the extreme groups with onset at < 60 years or > 79 years were significantly lower than those from the age groups 60-79 years. In {epsilon}3/{epsilon}4 individuals, sex-specific lifetime risk estimates by age 85 years (i.e., sex-specific penetrances by age 85 years) were 0.14 (95% CI 0.04-0.30) for men and 0.17 (95% CI 0.09-0.28) for women. 53 refs., 1 fig., 3 tabs.

  9. 38 CFR 4.17 - Total disability ratings for pension based on unemployability and age of the individual.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Total disability ratings for pension based on unemployability and age of the individual. 4.17 Section 4.17 Pensions, Bonuses... Rating § 4.17 Total disability ratings for pension based on unemployability and age of the...

  10. 38 CFR 4.17 - Total disability ratings for pension based on unemployability and age of the individual.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Total disability ratings for pension based on unemployability and age of the individual. 4.17 Section 4.17 Pensions, Bonuses... Rating § 4.17 Total disability ratings for pension based on unemployability and age of the...

  11. A Software System to Collect Expert Relevance Ratings of Medical Record Items for Specific Clinical Tasks

    PubMed Central

    Krishnaraj, Arun; Alkasab, Tarik K

    2014-01-01

    Development of task-specific electronic medical record (EMR) searches and user interfaces has the potential to improve the efficiency and safety of health care while curbing rising costs. The development of such tools must be data-driven and guided by a strong understanding of practitioner information requirements with respect to specific clinical tasks or scenarios. To acquire this important data, this paper describes a model by which expert practitioners are leveraged to identify which components of the medical record are most relevant to a specific clinical task. We also describe the computer system that was created to efficiently implement this model of data gathering. The system extracts medical record data from the EMR of patients matching a given clinical scenario, de-identifies the data, breaks the data up into separate medical record items (eg, radiology reports, operative notes, laboratory results, etc), presents each individual medical record item to experts under the hypothetical of the given clinical scenario, and records the experts’ ratings regarding the relevance of each medical record item to that specific clinical scenario or task. After an iterative process of data collection, these expert relevance ratings can then be pooled and used to design point-of-care EMR searches and user interfaces tailored to the task-specific needs of practitioners. PMID:25600925

  12. Overdispersion of the molecular clock: temporal variation of gene-specific substitution rates in Drosophila.

    PubMed

    Bedford, Trevor; Hartl, Daniel L

    2008-08-01

    Simple models of molecular evolution assume that sequences evolve by a Poisson process in which nucleotide or amino acid substitutions occur as rare independent events. In these models, the expected ratio of the variance to the mean of substitution counts equals 1, and substitution processes with a ratio greater than 1 are called overdispersed. Comparing the genomes of 10 closely related species of Drosophila, we extend earlier evidence for overdispersion in amino acid replacements as well as in four-fold synonymous substitutions. The observed deviation from the Poisson expectation can be described as a linear function of the rate at which substitutions occur on a phylogeny, which implies that deviations from the Poisson expectation arise from gene-specific temporal variation in substitution rates. Amino acid sequences show greater temporal variation in substitution rates than do four-fold synonymous sequences. Our findings provide a general phenomenological framework for understanding overdispersion in the molecular clock. Also, the presence of substantial variation in gene-specific substitution rates has broad implications for work in phylogeny reconstruction and evolutionary rate estimation.

  13. State-specific Dissociation Rates for H2(v, j) + H2(v‧, j‧)

    NASA Astrophysics Data System (ADS)

    Mandy, M. E.

    2016-08-01

    State-specific rate coefficients for the dissociation of H2 as the result of collisions with H2 were calculated for all combinations of (v, j) with an internal energy below 1 eV. Full-dimensional quasiclassical trajectories were calculated using the BMKP2 interaction potential with a minimum of 80,000 trajectories at each translational energy. Additional large batches of trajectories were carried out to calculate the cross sections near the threshold to dissociation to attain the desired precision of the rate coefficients. A piecewise linear excitation function was used to calculate the rate coefficient between 100 and 100,000 K. The resulting state-specific rate coefficients, γ, were parametrized as a function of temperature over the range 600-10,000 K using: {{log}}10 γ (t)=a+{bz}+{{cz}}2-d≤ft(\\displaystyle \\frac{1}{t}-1\\right) where t=T/4500 K and z={{log}}10 t. The values of the resulting rate coefficients were sensitive to the internal energy of both molecules, with initial vibrational energy having a slightly greater effect than rotational energy. This effect diminished as temperature increased.

  14. Sodium sulfate impacts feeding, specific dynamic action, and growth rate in the freshwater bivalve Corbicula fluminea.

    PubMed

    Soucek, David John

    2007-08-01

    Sodium sulfate is a ubiquitous salt that reaches toxic concentrations due to mining and other industrial activities, yet is currently unregulated at the Federal level in the United States. Previous studies have documented reduced growth of clams downstream of sulfate-dominated effluents, altered bioenergetics in filter-feeding invertebrates, and interactions between sulfate and other toxicants. Therefore, the purpose of this study was to determine if sodium sulfate affects the bioenergetics of the filter-feeding, freshwater bivalve, Corbicula fluminea, and the mechanism by which the effects are elicited. In addition to measuring effects on feeding, respiration and growth rates, I evaluated the relative sensitivity of a green algae consumed by clams to determine if top-down or bottom-up effects might be exhibited under field conditions. This study demonstrated that sodium sulfate had no effect on basal metabolic rates, but significantly reduced the feeding, post-feeding metabolic, and growth rates of C. fluminea. The proposed mechanism for these impacts is that filtering rates are reduced upon exposure, resulting in reduced food consumption and therefore, preventing increased metabolic rates normally associated with post-feeding specific dynamic action (SDA). In the field, these effects may cause changes in whole stream respiration rates and organic matter dynamics, as well as alter uptake rates of other food-associated contaminants like selenium, the toxicity of which is known to be antagonized by sulfate, in filter-feeding bivalves.

  15. p53 mutations associated with aging-related rise in cancer incidence rates

    PubMed Central

    Richardson, Richard B

    2013-01-01

    TP53’s role as guardian of the genome diminishes with age, as the probability of mutation increases. Previous studies have shown an association between p53 gene mutations and cancer. However, the role of somatic TP53 mutations in the steep rise in cancer rates with aging has not been investigated at a population level. This relationship was quantified using the International Agency for Research on Cancer (IARC) TP53 and GLOBOCAN cancer databases. The power function exponent of the cancer rate was calculated for 5-y age-standardized incidence or mortality rates for up to 25 cancer sites occurring in adults of median age 42 to 72 y. Linear regression analysis of the mean percentage of a cancer’s TP53 mutations and the corresponding cancer exponent was conducted for four populations: worldwide, Japan, Western Europe, and the United States. Significant associations (P ≤ 0.05) were found for incidence rates but not mortality rates. Regardless of the population studied, positive associations were found for all cancer sites, with more significant associations for solid tumors, excluding the outlier prostate cancer or sex-related tumors. Worldwide and Japanese populations yielded P values as low as 0.002 and 0.005, respectively. For the United States, a significant association was apparent only when analysis utilized the Surveillance, Epidemiology, and End Results (SEER) database. This study found that TP53 mutations accounts for approximately one-quarter and one-third of the aging-related rise in the worldwide and Japanese incidence of all cancers, respectively. These significant associations between TP53 mutations and the rapid rise in cancer incidence with aging, considered with previously published literature, support a causal role for TP53 according to the Bradford-Hill criteria. However, questions remain concerning the contribution of TP53 mutations to neoplastic development and the role of factors such as genetic instability, obesity, and gene deficiencies

  16. Radiocarbon-Based Ages and Growth Rates of Bamboo Corals from the Gulf of Alaska

    SciTech Connect

    Roark, E B; Guilderson, T P; Flood-Page, S; Dunbar, R B; Ingram, B L; Fallon, S J; McCulloch, M

    2004-12-12

    Deep-sea coral communities have long been recognized by fisherman as areas that support large populations of commercial fish. As a consequence, many deep-sea coral communities are threatened by bottom trawling. Successful management and conservation of this widespread deep-sea habitat requires knowledge of the age and growth rates of deep-sea corals. These organisms also contain important archives of intermediate and deep-water variability, and are thus of interest in the context of decadal to century-scale climate dynamics. Here, we present {Delta}{sup 14}C data that suggest that bamboo corals from the Gulf of Alaska are long-lived (75-126 years) and that they acquire skeletal carbon from two distinct sources. Independent verification of our growth rate estimates and coral ages is obtained by counting seasonal Sr/Ca cycles and probable lunar cycle growth bands.

  17. A comprehensive database of quality-rated fossil ages for Sahul's Quaternary vertebrates.

    PubMed

    Rodríguez-Rey, Marta; Herrando-Pérez, Salvador; Brook, Barry W; Saltré, Frédérik; Alroy, John; Beeton, Nicholas; Bird, Michael I; Cooper, Alan; Gillespie, Richard; Jacobs, Zenobia; Johnson, Christopher N; Miller, Gifford H; Prideaux, Gavin J; Roberts, Richard G; Turney, Chris S M; Bradshaw, Corey J A

    2016-07-19

    The study of palaeo-chronologies using fossil data provides evidence for past ecological and evolutionary processes, and is therefore useful for predicting patterns and impacts of future environmental change. However, the robustness of inferences made from fossil ages relies heavily on both the quantity and quality of available data. We compiled Quaternary non-human vertebrate fossil ages from Sahul published up to 2013. This, the FosSahul database, includes 9,302 fossil records from 363 deposits, for a total of 478 species within 215 genera, of which 27 are from extinct and extant megafaunal species (2,559 records). We also provide a rating of reliability of individual absolute age based on the dating protocols and association between the dated materials and the fossil remains. Our proposed rating system identified 2,422 records with high-quality ages (i.e., a reduction of 74%). There are many applications of the database, including disentangling the confounding influences of hypothetical extinction drivers, better spatial distribution estimates of species relative to palaeo-climates, and potentially identifying new areas for fossil discovery.

  18. A comprehensive database of quality-rated fossil ages for Sahul's Quaternary vertebrates.

    PubMed

    Rodríguez-Rey, Marta; Herrando-Pérez, Salvador; Brook, Barry W; Saltré, Frédérik; Alroy, John; Beeton, Nicholas; Bird, Michael I; Cooper, Alan; Gillespie, Richard; Jacobs, Zenobia; Johnson, Christopher N; Miller, Gifford H; Prideaux, Gavin J; Roberts, Richard G; Turney, Chris S M; Bradshaw, Corey J A

    2016-01-01

    The study of palaeo-chronologies using fossil data provides evidence for past ecological and evolutionary processes, and is therefore useful for predicting patterns and impacts of future environmental change. However, the robustness of inferences made from fossil ages relies heavily on both the quantity and quality of available data. We compiled Quaternary non-human vertebrate fossil ages from Sahul published up to 2013. This, the FosSahul database, includes 9,302 fossil records from 363 deposits, for a total of 478 species within 215 genera, of which 27 are from extinct and extant megafaunal species (2,559 records). We also provide a rating of reliability of individual absolute age based on the dating protocols and association between the dated materials and the fossil remains. Our proposed rating system identified 2,422 records with high-quality ages (i.e., a reduction of 74%). There are many applications of the database, including disentangling the confounding influences of hypothetical extinction drivers, better spatial distribution estimates of species relative to palaeo-climates, and potentially identifying new areas for fossil discovery. PMID:27434208

  19. A comprehensive database of quality-rated fossil ages for Sahul’s Quaternary vertebrates

    PubMed Central

    Rodríguez-Rey, Marta; Herrando-Pérez, Salvador; Brook, Barry W.; Saltré, Frédérik; Alroy, John; Beeton, Nicholas; Bird, Michael I.; Cooper, Alan; Gillespie, Richard; Jacobs, Zenobia; Johnson, Christopher N.; Miller, Gifford H.; Prideaux, Gavin J.; Roberts, Richard G.; Turney, Chris S.M.; Bradshaw, Corey J.A.

    2016-01-01

    The study of palaeo-chronologies using fossil data provides evidence for past ecological and evolutionary processes, and is therefore useful for predicting patterns and impacts of future environmental change. However, the robustness of inferences made from fossil ages relies heavily on both the quantity and quality of available data. We compiled Quaternary non-human vertebrate fossil ages from Sahul published up to 2013. This, the FosSahul database, includes 9,302 fossil records from 363 deposits, for a total of 478 species within 215 genera, of which 27 are from extinct and extant megafaunal species (2,559 records). We also provide a rating of reliability of individual absolute age based on the dating protocols and association between the dated materials and the fossil remains. Our proposed rating system identified 2,422 records with high-quality ages (i.e., a reduction of 74%). There are many applications of the database, including disentangling the confounding influences of hypothetical extinction drivers, better spatial distribution estimates of species relative to palaeo-climates, and potentially identifying new areas for fossil discovery. PMID:27434208

  20. Are age-related trends in suicide rates associated with life expectancy and socio-economic factors?

    PubMed

    Shah, Ajit

    2009-01-01

    Background. A recent cross-national study reported that suicide rates increased, decreased or remained unchanged with increasing age in individual countries. The relationship between age-related trends in suicide rates and child mortality rates, life expectancy and socio-economic factors was examined. Methods. Countries with an increase, decrease and no change in suicide rates with increasing age were ascertained from an earlier study (Shah, 2007a, International Psychogeriatrics, 19, 1141), which analysed data from the World Health Organisation (WHO). The relationship between age-related trends in suicide rates and (i) child mortality rates, (ii) life expectancy and (iii) markers of socio-economic status (per capita gross national domestic product (GDP) and the Gini coeffcient) was examined using data from the WHO and the United Nations. Results. The main findings were: (i) child mortality rates were significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; (ii) life expectancy was significantly higher in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; and (iii) the Gini coefficient was significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change or a decline in suicide rates with increasing age in females. Conclusions. Potential explanations for these findings and the interaction of life expectancy and socio-economic factors with other factors that differentially influence suicide rates in different age and sex groups requires further examination. PMID:24946117

  1. Are age-related trends in suicide rates associated with life expectancy and socio-economic factors?

    PubMed

    Shah, Ajit

    2009-01-01

    Background. A recent cross-national study reported that suicide rates increased, decreased or remained unchanged with increasing age in individual countries. The relationship between age-related trends in suicide rates and child mortality rates, life expectancy and socio-economic factors was examined. Methods. Countries with an increase, decrease and no change in suicide rates with increasing age were ascertained from an earlier study (Shah, 2007a, International Psychogeriatrics, 19, 1141), which analysed data from the World Health Organisation (WHO). The relationship between age-related trends in suicide rates and (i) child mortality rates, (ii) life expectancy and (iii) markers of socio-economic status (per capita gross national domestic product (GDP) and the Gini coeffcient) was examined using data from the WHO and the United Nations. Results. The main findings were: (i) child mortality rates were significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; (ii) life expectancy was significantly higher in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; and (iii) the Gini coefficient was significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change or a decline in suicide rates with increasing age in females. Conclusions. Potential explanations for these findings and the interaction of life expectancy and socio-economic factors with other factors that differentially influence suicide rates in different age and sex groups requires further examination.

  2. Notch Fracture Toughness of Glasses: Dependence on Rate, Age, and Geometry

    NASA Astrophysics Data System (ADS)

    Vasoya, Manish; Rycroft, Chris H.; Bouchbinder, Eran

    2016-08-01

    Understanding the fracture toughness (resistance) of glasses is a fundamental problem of prime theoretical and practical importance. Here we theoretically study its dependence on the loading rate, the age (history) of the glass, and the notch radius ρ . Reduced-dimensionality analysis suggests that the notch fracture toughness results from a competition between the initial, age- and history-dependent, plastic relaxation time scale τ0pl and an effective loading time scale τext(K˙ I,ρ ) , where K˙ I is the tensile stress-intensity-factor rate. The toughness is predicted to scale with √{ρ } independently of ξ ≡τext/τ0pl for ξ ≪1 , to scale as T √{ρ }log (ξ ) for ξ ≫1 (related to thermal activation, where T is the temperature), and to feature a nonmonotonic behavior in the crossover region ξ ˜O (1 ) (related to plastic yielding dynamics). These predictions are verified using 2D computations, providing a unified picture of the notch fracture toughness of glasses. The theory highlights the importance of time-scale competition and far-from-steady-state elasto-viscoplastic dynamics for understanding the toughness and shows that the latter varies quite significantly with the glass age (history) and applied loading rate. Experimental support for bulk metallic glasses is presented, and possible implications for applications are discussed.

  3. Aging and loading rate effects on the mechanical behavior of equine bone

    NASA Astrophysics Data System (ADS)

    Kulin, Robb M.; Jiang, Fengchun; Vecchio, Kenneth S.

    2008-06-01

    Whether due to a sporting accident, high-speed impact, fall, or other catastrophic event, the majority of clinical bone fractures occur under dynamic loading conditions. However, although extensive research has been performed on the quasi-static fracture and mechanical behavior of bone to date, few high-quality studies on the fracture behavior of bone at high strain rates have been performed. Therefore, many questions remain regarding the material behavior, including not only the loading-rate-dependent response of bone, but also how this response varies with age. In this study, tests were performed on equine femoral bone taken post-mortem from donors 6 months to 28 years of age. Quasi-static and dynamic tests were performed to determine the fracture toughness and compressive mechanical behavior as a function of age at varying loading rates. Fracture paths were then analyzed using scanning confocal and scanning-electron microscopy techniques to assess the role of various microstructural features on toughening mechanisms.

  4. Surface Ages and Resurfacing Rates of the Polar Layered Deposits on Mars

    USGS Publications Warehouse

    Herkenhoff, K. E.; Plaut, J.J.

    2000-01-01

    Interpretation of the polar stratigraphy of Mars in terms of global climate changes is complicated by the significant difference in surface ages between the north and south polar layered terrains inferred from crater statistics. We have reassessed the cratering record in both polar regions using Viking Orbiter and Mariner 9 images. No craters have been found in the north polar layered terrain, but the surface of most of the south polar layered deposits appears to have been stable for many of the orbital/axial cycles that are thought to have induced global climate changes on Mars. The inferred surface age of the south polar layered deposits (about 10 Ma) is two orders of magnitude greater than the surface age of the north polar layered deposits and residual cap (at most 100 ka). Similarly, modeled resurfacing rates are at least 20 times greater in the north than in the south. These results are consistent with the hypotheses that polar layered deposit resurfacing rates are highest in areas covered by perennial ice and that the differences in polar resurfacing rates result from the 6.4 km difference in elevation between the polar regions. Deposition on the portion of the south polar layered deposits that is not covered by the perennial ice cap may have ceased about 5 million years ago when the obliquity of Mars no longer exceeded 40??. ?? 2000 Academic Press.

  5. Labor Force Participation Rates among Working-Age Individuals with Visual Impairments

    ERIC Educational Resources Information Center

    Kelly, Stacy M.

    2013-01-01

    The present study analyzes four consecutive years of monthly labor force participation rates reported by the Current Population Survey that included nationally representative samples of the general U.S. population and nationally representative samples of the U.S. population with specifically identified disabilities. Visual impairment is one of the…

  6. Specific absorption rate determination of magnetic nanoparticles through hyperthermia measurements in non-adiabatic conditions

    NASA Astrophysics Data System (ADS)

    Coïsson, M.; Barrera, G.; Celegato, F.; Martino, L.; Vinai, F.; Martino, P.; Ferraro, G.; Tiberto, P.

    2016-10-01

    An experimental setup for magnetic hyperthermia operating in non-adiabatic conditions is described. A thermodynamic model that takes into account the heat exchanged by the sample with the surrounding environment is developed. A suitable calibration procedure is proposed that allows the experimental validation of the model. Specific absorption rate can then be accurately determined just from the measurement of the sample temperature at the equilibrium steady state. The setup and the measurement procedure represent a simplification with respect to other systems requiring calorimeters or crucial corrections for heat flow. Two families of magnetic nanoparticles, one superparamagnetic and one characterised by larger sizes and static hysteresis, have been characterised as a function of field intensity, and specific absorption rate and intrinsic loss power have been obtained.

  7. Specific absorption rate analysis of broadband mobile antenna with negative index metamaterial

    NASA Astrophysics Data System (ADS)

    Alam, Touhidul; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

    2016-03-01

    This paper presents a negative index metamaterial-inspired printed mobile wireless antenna that can support most mobile applications such as GSM, UMTS, Bluetooth and WLAN frequency bands. The antenna consists of a semi-circular patch, a 50Ω microstrip feed line and metamaterial ground plane. The antenna occupies a very small space of 37 × 47 × 0.508 mm3, making it suitable for mobile wireless application. The perceptible novelty shown in this proposed antenna is that reduction of specific absorption rate using the negative index metamaterial ground plane. The proposed antenna reduced 72.11 and 75.53 % of specific absorption rate at 1.8 and 2.4 GHz, respectively.

  8. Physiological optimization underlies growth rate-independent chlorophyll-specific gross and net primary production.

    PubMed

    Halsey, Kimberly H; Milligan, Allen J; Behrenfeld, Michael J

    2010-02-01

    Characterization of physiological variability in phytoplankton photosynthetic efficiencies is one of the greatest challenges in assessing ocean net primary production (NPP) from remote sensing of surface chlorophyll (Chl). Nutrient limitation strongly influences phytoplankton intracellular pigmentation, but its impact on Chl-specific NPP (NPP(*)) is debated. We monitored six indices of photosynthetic activity in steady-state Dunaliella tertiolecta cultures over a range of nitrate-limited growth rates (μ), including photosynthetic efficiency of PSII (F(v)/F(m)), O(2)-based gross and net production, 20 min and 24 h carbon assimilation, and carbon- and μ-based NPP. Across all growth rates, O(2)-based Chl-specific gross primary production (GPP(*)(O(2))), NPP(*), and F(v)/F(m) were constant. GPP(*)(O(2)) was 3.3 times greater than NPP(*). In stark contrast, Chl-specific short-term C fixation showed clear linear dependence on μ, reflecting differential allocation of photosynthate between short-lived C products and longer-term storage products. Indeed, (14)C incorporation into carbohydrates was five times greater in cells growing at 1.2 day(-1) than 0.12 day(-1). These storage products are catabolized for ATP and reductant generation within the period of a cell cycle. The relationship between Chl-specific gross and net O(2) production, short-term (14)C-uptake, NPP(*), and growth rate reflects cellular-level regulation of fundamental metabolic pathways in response to nutrient limitation. We conclude that growth rate-dependent photosynthate metabolism bridges the gap between gross and net production and resolves a controversial question regarding nutrient limitation effects on primary production measures.

  9. 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

  10. Theory of mind and specific language impairment in school-age children.

    PubMed

    Spanoudis, George

    2016-01-01

    Research on the relationship between aspects of language development and Theory of Mind (ToM) in children with language impairments suggests that children with language impairment show a delay in ToM development. This study aimed to examine the relationships of the syntactic, semantic, and pragmatic skills with ToM in school-age children. Twenty children with Specific Language Impairment (SLI) aged 9-12 years and two control groups, one matched for chronological age (CA) and one for language ability (LA) (aged 8-10 years) were compared on a set of language tasks tapping syntactic, semantic, and pragmatic skills and on an advanced test of ToM. Results showed that children with SLI performed poorly on the ToM task compared to the CA matches. Also, analysis showed that language skills and ToM are related and that syntactic and pragmatic abilities contributed significantly to the prediction of ToM performance in the SLI group. It is concluded that the syntax/pragmatic aspects of the language impact on ToM understanding in children with SLI.

  11. Fat-specific Dicer deficiency accelerates aging and mitigates several effects of dietary restriction in mice

    PubMed Central

    Reis, Felipe C. G.; Branquinho, Jéssica L. O.; Brandão, Bruna B.; Guerra, Beatriz A.; Silva, Ismael D.; Frontini, Andrea; Thomou, Thomas; Sartini, Loris; Cinti, Saverio; Kahn, C. Ronald; Festuccia, William T.; Kowaltowski, Alicia J.; Mori, Marcelo A.

    2016-01-01

    Aging increases the risk of type 2 diabetes, and this can be prevented by dietary restriction (DR). We have previously shown that DR inhibits the downregulation of miRNAs and their processing enzymes - mainly Dicer - that occurs with aging in mouse white adipose tissue (WAT). Here we used fat-specific Dicer knockout mice (AdicerKO) to understand the contributions of adipose tissue Dicer to the metabolic effects of aging and DR. Metabolomic data uncovered a clear distinction between the serum metabolite profiles of Lox control and AdicerKO mice, with a notable elevation of branched-chain amino acids (BCAA) in AdicerKO. These profiles were associated with reduced oxidative metabolism and increased lactate in WAT of AdicerKO mice and were accompanied by structural and functional changes in mitochondria, particularly under DR. AdicerKO mice displayed increased mTORC1 activation in WAT and skeletal muscle, where Dicer expression is not affected. This was accompanied by accelerated age-associated insulin resistance and premature mortality. Moreover, DR-induced insulin sensitivity was abrogated in AdicerKO mice. This was reverted by rapamycin injection, demonstrating that insulin resistance in AdicerKO mice is caused by mTORC1 hyperactivation. Our study evidences a DR-modulated role for WAT Dicer in controlling metabolism and insulin resistance. PMID:27241713

  12. 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

  13. Cartilage-Specific Knockout of the Mechanosensory Ion Channel TRPV4 Decreases Age-Related Osteoarthritis.

    PubMed

    O'Conor, Christopher J; Ramalingam, Sendhilnathan; Zelenski, Nicole A; Benefield, Halei C; Rigo, Isaura; Little, Dianne; Wu, Chia-Lung; Chen, Di; Liedtke, Wolfgang; McNulty, Amy L; Guilak, Farshid

    2016-01-01

    Osteoarthritis (OA) is a progressive degenerative disease of articular cartilage and surrounding tissues, and is associated with both advanced age and joint injury. Biomechanical factors play a critical role in the onset and progression of OA, yet the mechanisms through which physiologic or pathologic mechanical signals are transduced into a cellular response are not well understood. Defining the role of mechanosensory pathways in cartilage during OA pathogenesis may yield novel strategies or targets for the treatment of OA. The transient receptor potential vanilloid 4 (TRPV4) ion channel transduces mechanical loading of articular cartilage via the generation of intracellular calcium ion transients. Using tissue-specific, inducible Trpv4 gene-targeted mice, we demonstrate that loss of TRPV4-mediated cartilage mechanotransduction in adulthood reduces the severity of aging-associated OA. However, loss of chondrocyte TRPV4 did not prevent OA development following destabilization of the medial meniscus (DMM). These results highlight potentially distinct roles of TRPV4-mediated cartilage mechanotransduction in age-related and post-traumatic OA, and point to a novel disease-modifying strategy to therapeutically target the TRPV4-mediated mechanotransduction pathway for the treatment of aging-associated OA. PMID:27388701

  14. Cartilage-Specific Knockout of the Mechanosensory Ion Channel TRPV4 Decreases Age-Related Osteoarthritis

    PubMed Central

    O’Conor, Christopher J.; Ramalingam, Sendhilnathan; Zelenski, Nicole A.; Benefield, Halei C.; Rigo, Isaura; Little, Dianne; Wu, Chia-Lung; Chen, Di; Liedtke, Wolfgang; McNulty, Amy L.; Guilak, Farshid

    2016-01-01

    Osteoarthritis (OA) is a progressive degenerative disease of articular cartilage and surrounding tissues, and is associated with both advanced age and joint injury. Biomechanical factors play a critical role in the onset and progression of OA, yet the mechanisms through which physiologic or pathologic mechanical signals are transduced into a cellular response are not well understood. Defining the role of mechanosensory pathways in cartilage during OA pathogenesis may yield novel strategies or targets for the treatment of OA. The transient receptor potential vanilloid 4 (TRPV4) ion channel transduces mechanical loading of articular cartilage via the generation of intracellular calcium ion transients. Using tissue-specific, inducible Trpv4 gene-targeted mice, we demonstrate that loss of TRPV4-mediated cartilage mechanotransduction in adulthood reduces the severity of aging-associated OA. However, loss of chondrocyte TRPV4 did not prevent OA development following destabilization of the medial meniscus (DMM). These results highlight potentially distinct roles of TRPV4-mediated cartilage mechanotransduction in age-related and post-traumatic OA, and point to a novel disease-modifying strategy to therapeutically target the TRPV4-mediated mechanotransduction pathway for the treatment of aging-associated OA. PMID:27388701

  15. Age- and Sex-Specific Causal Effects of Adiposity on Cardiovascular Risk Factors

    PubMed Central

    Fall, Tove; Hägg, Sara; Ploner, Alexander; Mägi, Reedik; Fischer, Krista; Draisma, Harmen H.M.; Sarin, Antti-Pekka; Benyamin, Beben; Ladenvall, Claes; Åkerlund, Mikael; Kals, Mart; Esko, Tõnu; Nelson, Christopher P.; Kaakinen, Marika; Huikari, Ville; Mangino, Massimo; Meirhaeghe, Aline; Kristiansson, Kati; Nuotio, Marja-Liisa; Kobl, Michael; Grallert, Harald; Dehghan, Abbas; Kuningas, Maris; de Vries, Paul S.; de Bruijn, Renée F.A.G.; Willems, Sara M.; Heikkilä, Kauko; Silventoinen, Karri; Pietiläinen, Kirsi H.; Legry, Vanessa; Giedraitis, Vilmantas; Goumidi, Louisa; Syvänen, Ann-Christine; Strauch, Konstantin; Koenig, Wolfgang; Lichtner, Peter; Herder, Christian; Palotie, Aarno; Menni, Cristina; Uitterlinden, André G.; Kuulasmaa, Kari; Havulinna, Aki S.; Moreno, Luis A.; Gonzalez-Gross, Marcela; Evans, Alun; Tregouet, David-Alexandre; Yarnell, John W.G.; Virtamo, Jarmo; Ferrières, Jean; Veronesi, Giovanni; Perola, Markus; Arveiler, Dominique; Brambilla, Paolo; Lind, Lars; Kaprio, Jaakko; Hofman, Albert; Stricker, Bruno H.; van Duijn, Cornelia M.; Ikram, M. Arfan; Franco, Oscar H.; Cottel, Dominique; Dallongeville, Jean; Hall, Alistair S.; Jula, Antti; Tobin, Martin D.; Penninx, Brenda W.; Peters, Annette; Gieger, Christian; Samani, Nilesh J.; Montgomery, Grant W.; Whitfield, John B.; Martin, Nicholas G.; Groop, Leif; Spector, Tim D.; Magnusson, Patrik K.; Amouyel, Philippe; Boomsma, Dorret I.; Nilsson, Peter M.; Järvelin, Marjo-Riitta; Lyssenko, Valeriya; Metspalu, Andres; Strachan, David P.; Salomaa, Veikko; Ripatti, Samuli; Pedersen, Nancy L.; Prokopenko, Inga; McCarthy, Mark I.

    2015-01-01

    Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian randomization approach, applying a set of 32 genetic markers to estimate the causal effect of adiposity on blood pressure, glycemic indices, circulating lipid levels, and markers of inflammation and liver disease in up to 67,553 individuals. All analyses were stratified by age (cutoff 55 years of age) and sex. The genetic score was associated with BMI in both nonstratified analysis (P = 2.8 × 10−107) and stratified analyses (all P < 3.3 × 10−30). We found evidence of a causal effect of adiposity on blood pressure, fasting levels of insulin, C-reactive protein, interleukin-6, HDL cholesterol, and triglycerides in a nonstratified analysis and in the <55-year stratum. Further, we found evidence of a smaller causal effect on total cholesterol (P for difference = 0.015) in the ≥55-year stratum than in the <55-year stratum, a finding that could be explained by biology, survival bias, or differential medication. In conclusion, this study extends previous knowledge of the effects of adiposity by providing sex- and age-specific causal estimates on cardiovascular risk factors. PMID:25712996

  16. Emergent literacy profiles of preschool-age children with specific language impairment.

    PubMed

    Cabell, Sonia Q; Lomax, Richard G; Justice, Laura M; Breit-Smith, Allison; Skibbe, Lori E; McGinty, Anita S

    2010-12-01

    The primary aim of the present study was to explore the heterogeneity of emergent literacy skills among preschool-age children with specific language impairment (SLI) through examination of profiles of performance. Fifty-nine children with SLI were assessed on a battery of emergent literacy skills (i.e., alphabet knowledge, print concepts, emergent writing, rhyme awareness) and oral language skills (i.e., receptive/expressive vocabulary and grammar). Cluster analysis techniques identified three emergent literacy profiles: (1) Highest Emergent Literacy, Strength in Alphabet Knowledge; (2) Average Emergent Literacy, Strength in Print Concepts; and (3) Lowest Emergent Literacy across Skills. After taking into account the contribution of child age, receptive and expressive language skills made a small contribution to the prediction of profile membership. The present findings, which may be characterized as exploratory given the relatively modest sample size, suggest that preschool-age children with SLI display substantial individual differences with regard to their emergent literacy skills and that these differences cannot be fully determined by children's age or oral language performance. Replication of the present findings with a larger sample of children is needed.

  17. Reduced specificity of functional connectivity in the aging brain during task performance.

    PubMed

    Geerligs, Linda; Maurits, Natasha M; Renken, Remco J; Lorist, Monicque M

    2014-01-01

    The importance of studying connectivity in the aging brain is increasingly recognized. Recent studies have shown that connectivity within the default mode network is reduced with age and have demonstrated a clear relation of these changes with cognitive functioning. However, research on age-related changes in other functional networks is sparse and mainly focused on prespecified functional networks. Using functional magnetic resonance imaging, we investigated age-related changes in functional connectivity during a visual oddball task in a range of functional networks. It was found that compared with young participants, elderly showed a decrease in connectivity between areas belonging to the same functional network. This was found in the default mode network and the somatomotor network. Moreover, in all identified networks, elderly showed increased connectivity between areas within these networks and areas belonging to different functional networks. Decreased connectivity within functional networks was related to poorer cognitive functioning in elderly. The results were interpreted as a decrease in the specificity of functional networks in older participants.

  18. Emergent literacy profiles of preschool-age children with specific language impairment.

    PubMed

    Cabell, Sonia Q; Lomax, Richard G; Justice, Laura M; Breit-Smith, Allison; Skibbe, Lori E; McGinty, Anita S

    2010-12-01

    The primary aim of the present study was to explore the heterogeneity of emergent literacy skills among preschool-age children with specific language impairment (SLI) through examination of profiles of performance. Fifty-nine children with SLI were assessed on a battery of emergent literacy skills (i.e., alphabet knowledge, print concepts, emergent writing, rhyme awareness) and oral language skills (i.e., receptive/expressive vocabulary and grammar). Cluster analysis techniques identified three emergent literacy profiles: (1) Highest Emergent Literacy, Strength in Alphabet Knowledge; (2) Average Emergent Literacy, Strength in Print Concepts; and (3) Lowest Emergent Literacy across Skills. After taking into account the contribution of child age, receptive and expressive language skills made a small contribution to the prediction of profile membership. The present findings, which may be characterized as exploratory given the relatively modest sample size, suggest that preschool-age children with SLI display substantial individual differences with regard to their emergent literacy skills and that these differences cannot be fully determined by children's age or oral language performance. Replication of the present findings with a larger sample of children is needed. PMID:20586530

  19. Fat-specific Dicer deficiency accelerates aging and mitigates several effects of dietary restriction in mice.

    PubMed

    Reis, Felipe C G; Branquinho, Jéssica L O; Brandão, Bruna B; Guerra, Beatriz A; Silva, Ismael D; Frontini, Andrea; Thomou, Thomas; Sartini, Loris; Cinti, Saverio; Kahn, C Ronald; Festuccia, William T; Kowaltowski, Alicia J; Mori, Marcelo A

    2016-06-01

    Aging increases the risk of type 2 diabetes, and this can be prevented by dietary restriction (DR). We have previously shown that DR inhibits the downregulation of miRNAs and their processing enzymes - mainly Dicer - that occurs with aging in mouse white adipose tissue (WAT). Here we used fat-specific Dicer knockout mice (AdicerKO) to understand the contributions of adipose tissue Dicer to the metabolic effects of aging and DR. Metabolomic data uncovered a clear distinction between the serum metabolite profiles of Lox control and AdicerKO mice, with a notable elevation of branched-chain amino acids (BCAA) in AdicerKO. These profiles were associated with reduced oxidative metabolism and increased lactate in WAT of AdicerKO mice and were accompanied by structural and functional changes in mitochondria, particularly under DR. AdicerKO mice displayed increased mTORC1 activation in WAT and skeletal muscle, where Dicer expression is not affected. This was accompanied by accelerated age-associated insulin resistance and premature mortality. Moreover, DR-induced insulin sensitivity was abrogated in AdicerKO mice. This was reverted by rapamycin injection, demonstrating that insulin resistance in AdicerKO mice is caused by mTORC1 hyperactivation. Our study evidences a DR-modulated role for WAT Dicer in controlling metabolism and insulin resistance. PMID:27241713

  20. Markov models of breast tumor progression: some age-specific results.

    PubMed

    Duffy, S W; Day, N E; Tabár, L; Chen, H H; Smith, T C

    1997-01-01

    Researchers have noted that mammographic screening has a reduced effect on breast cancer mortality in women in their forties compared to older women. Explanations for this include poorer sensitivity in younger women due to denser breast tissue, as well as more rapid tumor progression, giving a shorter mean sojourn time (the average duration of the preclinical screen-detectable period). To test these hypotheses, we developed a series of Markov-chain models to estimate tumor progression rates and sensitivity. Parameters were estimated using tumor data from the Swedish two-county trial of mammographic screening for breast cancer. The mean sojourn time was shorter in women aged 40-49 compared to women aged 50-59 and 60-69 (2.44, 3.70, and 4.17 years, respectively). Sensitivity was lower in the 40-49 age group compared to the two older groups (83%, 100%, and 100%, respectively). Thus, both rapid progression and poorer sensitivity are associated with the 40-49 age group. We also modeled tumor size, node status, and malignancy grade together with subsequent breast cancer mortality and found that, to achieve a reduction in mortality commensurate with that in women over 50, the interscreening interval for women in their forties should be less than two years. We conclude that Markov models and the use of tumor size, node status, and malignancy grade as surrogates for mortality can be useful in design and analysis of future studies of breast cancer screening.

  1. Markov models of breast tumor progression: some age-specific results.

    PubMed

    Duffy, S W; Day, N E; Tabár, L; Chen, H H; Smith, T C

    1997-01-01

    Researchers have noted that mammographic screening has a reduced effect on breast cancer mortality in women in their forties compared to older women. Explanations for this include poorer sensitivity in younger women due to denser breast tissue, as well as more rapid tumor progression, giving a shorter mean sojourn time (the average duration of the preclinical screen-detectable period). To test these hypotheses, we developed a series of Markov-chain models to estimate tumor progression rates and sensitivity. Parameters were estimated using tumor data from the Swedish two-county trial of mammographic screening for breast cancer. The mean sojourn time was shorter in women aged 40-49 compared to women aged 50-59 and 60-69 (2.44, 3.70, and 4.17 years, respectively). Sensitivity was lower in the 40-49 age group compared to the two older groups (83%, 100%, and 100%, respectively). Thus, both rapid progression and poorer sensitivity are associated with the 40-49 age group. We also modeled tumor size, node status, and malignancy grade together with subsequent breast cancer mortality and found that, to achieve a reduction in mortality commensurate with that in women over 50, the interscreening interval for women in their forties should be less than two years. We conclude that Markov models and the use of tumor size, node status, and malignancy grade as surrogates for mortality can be useful in design and analysis of future studies of breast cancer screening. PMID:9709283

  2. Chronographic Imprint of Age-Induced Alterations in Heart Rate Dynamical Organization

    PubMed Central

    Makowiec, Danuta; Wejer, Dorota; Kaczkowska, Agnieszka; Żarczyńska-Buchowiecka, Marta; Struzik, Zbigniew R.

    2015-01-01

    Beat-to-beat changes in the heart period are transformed into a network of increments between subsequent RR-intervals, which enables graphical descriptions of short-term heart period variability. Three types of such descriptions are considered: (1) network graphs arising from a set of vertices and directed edges, (2) contour plots of adjacency matrices A, representing the networks and transition matrices T, resulting from A, and (3) vector plots of gradients of the matrices A and T. Two indices are considered which summarize properties of A and T: the approximate deceleration capacity and the entropy rate. The method, applied to time series of nocturnal RR-intervals recorded from healthy subjects of different ages, reveals important aspect of changes in the autonomic activity caused by biological aging. Independent of the subject’s age, following accelerations, a pendulum-like dynamics appears. With decelerations, this dynamics develops in line with the subject’s age. This aging transition can be graphically visualized by vectors connecting the maxima of the transition probabilities of T, which, metaphorically, resemble a chronometer or the hands of a clock. PMID:26236241

  3. Position specific variation in the rate of evolution intranscription factor binding sites

    SciTech Connect

    Moses, Alan M.; Chiang, Derek Y.; Kellis, Manolis; Lander, EricS.; Eisen, Michael B.

    2003-08-28

    The binding sites of sequence specific transcription factors are an important and relatively well-understood class of functional non-coding DNAs. Although a wide variety of experimental and computational methods have been developed to characterize transcription factor binding sites, they remain difficult to identify. Comparison of non-coding DNA from related species has shown considerable promise in identifying these functional non-coding sequences, even though relatively little is known about their evolution. Here we analyze the genome sequences of the budding yeasts Saccharomyces cerevisiae, S. bayanus, S. paradoxus and S. mikataeto study the evolution of transcription factor binding sites. As expected, we find that both experimentally characterized and computationally predicted binding sites evolve slower than surrounding sequence, consistent with the hypothesis that they are under purifying selection. We also observe position-specific variation in the rate of evolution within binding sites. We find that the position-specific rate of evolution is positively correlated with degeneracy among binding sites within S. cerevisiae. We test theoretical predictions for the rate of evolution at positions where the base frequencies deviate from background due to purifying selection and find reasonable agreement with the observed rates of evolution. Finally, we show how the evolutionary characteristics of real binding motifs can be used to distinguish them from artifacts of computational motif finding algorithms. As has been observed for protein sequences, the rate of evolution in transcription factor binding sites varies with position, suggesting that some regions are under stronger functional constraint than others. This variation likely reflects the varying importance of different positions in the formation of the protein-DNA complex. The characterization of the pattern of evolution in known binding sites will likely contribute to the effective use of comparative

  4. Reduced neural specificity in middle-aged HIV+ women in the absence of behavioral deficits.

    PubMed

    Liu, Chenglong; Wang, Cuiwei; Leclair, Matthew; Young, Mary; Jiang, Xiong

    2015-01-01

    In the post combination antiretroviral therapy (cART) era, the prevalence of mild forms of HIV-associated neurocognitive disorders (HAND) in individuals with HIV-infection remains high. There is a pressing need to find biomarkers that can aid clinical assessment of HAND, especially in those with mild or no neurocognitive symptoms. Here we hypothesized that a reduction in neural specificity, or the specificity of neuronal tuning, could serve as a potential biomarker of asymptomatic HAND. To directly test this hypothesis, we applied two advanced fMRI techniques to examine the difference in neural specificity between middle-aged HIV+ women and age-matched negative controls, with a focus on the fusiform face area (FFA), a critical region in face processing. Face discrimination performance was assessed outside of the scanner. While the behavioral performance of face discrimination was comparable between the two groups, a reduced neural specificity in the FFA of HIV-positive women was revealed by a novel fMRI analysis technique, local regional heterogeneity analysis, or Hcorr , as well as an established technique, fMRI-rapid adaptation. In contrast, conventional fMRI techniques were insensitive to these early changes. These results suggest that, prior to the onset of detectable behavioral deficits, significant neuronal dysfunctions are already present in HIV+ individuals, and these early neuronal dysfunctions can be detected and assessed via neural specificity, which, in combining with the novel Hcorr technique, has a strong potential to serve as a biomarker of asymptomatic HAND and other neurodegenerative diseases. PMID:26288750

  5. Nanotechnology-based drug delivery treatments and specific targeting therapy for age-related macular degeneration.

    PubMed

    Lin, Tai-Chi; Hung, Kuo-Hsuan; Peng, Chi-Hsien; Liu, Jorn-Hon; Woung, Lin-Chung; Tsai, Ching-Yao; Chen, Shih-Jen; Chen, Yan-Ting; Hsu, Chih-Chien

    2015-11-01

    Nanoparticles combined with cells, drugs, and specially designed genes provide improved therapeutic efficacy in studies and clinical setting, demonstrating a new era of treatment strategy, especially in retinal diseases. Nanotechnology-based drugs can provide an essential platform for sustaining, releasing and a specific targeting design to treat retinal diseases. Poly-lactic-co-glycolic acid is the most widely used biocompatible and biodegradable polymer approved by the Food and Drug Administration. Many studies have attempted to develop special devices for delivering small-molecule drugs, proteins, and other macromolecules consistently and slowly. In this article, we first review current progress in the treatment of age-related macular degeneration. Then, we discuss the function of vascular endothelial growth factor (VEGF) and the pharmacological effects of anti-VEGF-A antibodies and soluble or modified VEGF receptors. Lastly, we summarize the combination of antiangiogenic therapy and nanomedicines, and review current potential targeting therapy in age-related macular degeneration.

  6. Age-specific inhalation radiation dose commitment factors for selected radionuclides

    SciTech Connect

    Strenge, D.L.; Peloquin, R.A.; Baker, D.A.

    1982-08-01

    Inhalation dose commitment factors are presented for selected radionuclides for exposure of individuals in four age groups: infant, child, teen and adult. Radionuclides considered are /sup 35/S, /sup 36/Cl, /sup 45/Ca, /sup 67/Ga, /sup 75/Se, /sup 85/Sr, /sup 109/Cd, /sup 113/Sn, /sup 125/I, /sup 133/Ba, /sup 170/Tm, /sup 169/Yb, /sup 182/Ta, /sup 192/Ir, /sup 198/Au, /sup 201/Tl, /sup 204/Tl, and /sup 236/Pu. The calculational method is based on the human metabolic model of ICRP as defined in Publication 2 (ICRP 1959) and as used in previous age-specific dose factor calculations by Hoenes and Soldat (1977). Dose commitment factors are presented for the following organs of reference: total body, bone, liver, kidney, thyroid, lung and lower large intestine.

  7. Sensitivity and Specificity of Portable Hearing Screening in Middle-Aged and Older Adults

    PubMed Central

    Cardoso, Carolina Louise; Bós, Ângelo José Gonçalves; Gonçalves, Andréa Krüger; Olchik, Maira Rozenfeld; Flores, Leticia Sousa; Seimetz, Bruna Macagnin; Bauer, Magda Aline; Coradini, Patricia Pérez; Teixeira, Adriane Ribeiro

    2013-01-01

    Introduction Hearing screening allows the identification of individuals with hearing loss. Aim To determine the sensitivity and specificity of a portable hearing screening device in middle-aged and older adults using the manufacturer scoring and a scoring system proposed by the researchers. Methods In this transversal study, participants underwent anamnesis, otoscopy, and hearing screening using portable equipment. After this, a pure tone audiometry was performed, with participants classified into two groups: with and without hearing loss. The sensitivity and specificity of the hearing screening were calculated for the right and left ears using two methods of interpretation: the original method recommended by the manufacturer (criteria 1) and the method proposed by researchers (criteria 2). Results The sample consisted of 55 individuals, 83.6% (n = 46) of whom were women. Per criteria 1, the sensitivities were 26.3 (right ear) and 21.4% (left ear). The specificity was 100% for both ears. Using criteria 2, the sensitivity was 94.7 (right ear) and 100% (left ear). The specificity was 74.3 (right ear) and 65.9% (left ear). Conclusion This study showed that the criteria proposed by the manufacturer presented low sensitivity in the hearing screening. The criteria proposed by the researchers to achieve a more efficient performance reached high and balanced values for sensitivity and specificity. PMID:25992058

  8. The development of global and domain-specific self-esteem from age 13 to 31.

    PubMed

    von Soest, Tilmann; Wichstrøm, Lars; Kvalem, Ingela Lundin

    2016-04-01

    This study examines the development of global self-esteem and self-esteem in 6 specific domains across adolescence and young adulthood. Using a cohort-sequential design, we analyzed longitudinal data on 3,116 Norwegian men and women from 13 to 31 years of age by means of growth curve modeling. Questionnaire data provided information on global self-esteem and self-esteem in social, academic, athletic, and appearance domains. Data on important life outcomes was provided by register linkages. Results showed increasing levels of global self-esteem and self-esteem in most domains with increasing age. Being male, higher parental education, and reported higher levels of parental care were related to higher levels of global self-esteem and self-esteem in several domains. Self-esteem in the appearance domain showed high and stable correlations with global self-esteem, whereas in social domains, correlations with global self-esteem increased over age, with a particularly steep increase for romantic appeal self-esteem. As to the prospective relationship between self-esteem and important life outcomes, results showed that participants high in academic self-esteem attained higher education levels and higher income, but most of the relationship was explained by covariates such as parents' socioeconomic status and school grades. Low global self-esteem predicted later prescription of antidepressants, even after controlling for covariates. This study is the first to provide a comprehensive picture of the development of global and domain-specific self-esteem throughout adolescence and young adulthood using long-term longitudinal data. The results underscore the importance of examining development of self-esteem in specific domains in addition to global self-esteem. PMID:26167796

  9. The development of global and domain-specific self-esteem from age 13 to 31.

    PubMed

    von Soest, Tilmann; Wichstrøm, Lars; Kvalem, Ingela Lundin

    2016-04-01

    This study examines the development of global self-esteem and self-esteem in 6 specific domains across adolescence and young adulthood. Using a cohort-sequential design, we analyzed longitudinal data on 3,116 Norwegian men and women from 13 to 31 years of age by means of growth curve modeling. Questionnaire data provided information on global self-esteem and self-esteem in social, academic, athletic, and appearance domains. Data on important life outcomes was provided by register linkages. Results showed increasing levels of global self-esteem and self-esteem in most domains with increasing age. Being male, higher parental education, and reported higher levels of parental care were related to higher levels of global self-esteem and self-esteem in several domains. Self-esteem in the appearance domain showed high and stable correlations with global self-esteem, whereas in social domains, correlations with global self-esteem increased over age, with a particularly steep increase for romantic appeal self-esteem. As to the prospective relationship between self-esteem and important life outcomes, results showed that participants high in academic self-esteem attained higher education levels and higher income, but most of the relationship was explained by covariates such as parents' socioeconomic status and school grades. Low global self-esteem predicted later prescription of antidepressants, even after controlling for covariates. This study is the first to provide a comprehensive picture of the development of global and domain-specific self-esteem throughout adolescence and young adulthood using long-term longitudinal data. The results underscore the importance of examining development of self-esteem in specific domains in addition to global self-esteem.

  10. Heart rate variability and cardiac reflexes in small for gestational age infants.

    PubMed

    Galland, Barbara C; Taylor, Barry J; Bolton, David P G; Sayers, Rachel M

    2006-03-01

    To assess the influence of intrauterine growth retardation and postnatal development on heart rate variability (HRV) and cardiac reflexes, we studied 27 healthy small for gestational age (SGA) and 23 appropriate for gestational age (AGA) infants during a nap study. Resting HRV was assessed by point dispersion of Poincaré plots for overall (SDRR) and instantaneous beat-to-beat variability (SDDeltaRR) and the ratio (SDRR/SDDeltaRR). Heart rate reflex and arousal responses to a 60 degrees head-up tilt were determined. All tests/measures were repeated twice in quiet and active sleep and in prone and supine sleep positions at 1 and 3 mo of age. SGA infants exhibited higher resting sympathetic tone [SDRR/SDDeltaRR: 1.9 (95% confidence interval: 1.7, 2.0) and 1.7 (95% confidence interval: 1.5, 1.8) in SGA and AGA, respectively; P=0.046] and a tendency for a smaller tachycardic reflex response to the tilt [Deltaheart rate: 24 beats/min (95% confidence interval: 20, 28) and 30 (95% confidence interval: 25, 34)] in SGA and AGA, respectively; P=0.06]. HRV indexes were reduced in the prone compared with supine position (P<0.0001), but reflex tilt responses were unchanged with position. SGA/AGA differences were independent of sleep position. Gestational age weight status did not influence the likelihood of arousal, but prone sleeping per se reduced the odds 2.5-fold. The findings suggest reduced autonomic activity and cardiac reflexes in SGA infants. The finding that the sympathetic component of the control of HRV was higher in SGA infants could link with findings in adulthood of an association between being born SGA and a higher risk of cardiovascular disease. PMID:16306252

  11. Effects of age and loading rate on equine cortical bone failure.

    PubMed

    Kulin, Robb M; Jiang, Fengchun; Vecchio, Kenneth S

    2011-01-01

    Although clinical bone fractures occur predominantly under impact loading (as occurs during sporting accidents, falls, high-speed impacts or other catastrophic events), experimentally validated studies on the dynamic fracture behavior of bone, at the loading rates associated with such events, remain limited. In this study, a series of tests were performed on femoral specimens obtained post-mortem from equine donors ranging in age from 6 months to 28 years. Fracture toughness and compressive tests were performed under both quasi-static and dynamic loading conditions in order to determine the effects of loading rate and age on the mechanical behavior of the cortical bone. Fracture toughness experiments were performed using a four-point bending geometry on single and double-notch specimens in order to measure fracture toughness, as well as observe differences in crack initiation between dynamic and quasi-static experiments. Compressive properties were measured on bone loaded parallel and transverse to the osteonal growth direction. Fracture propagation was then analyzed using scanning electron and scanning confocal microscopy to observe the effects of microstructural toughening mechanisms at different strain rates. Specimens from each horse were also analyzed for dry, wet and mineral densities, as well as weight percent mineral, in order to investigate possible influences of composition on mechanical behavior. Results indicate that bone has a higher compressive strength, but lower fracture toughness when tested dynamically as compared to quasi-static experiments. Fracture toughness also tends to decrease with age when measured quasi-statically, but shows little change with age under dynamic loading conditions, where brittle "cleavage-like" fracture behavior dominates.

  12. Longitudinal Assessment of Global and Regional Rate of Grey Matter Atrophy in 1,172 Healthy Older Adults: Modulation by Sex and Age

    PubMed Central

    Crivello, Fabrice; Tzourio-Mazoyer, Nathalie; Tzourio, Christophe; Mazoyer, Bernard

    2014-01-01

    To characterize the neuroanatomical changes in healthy older adults is important to differentiate pathological from normal brain structural aging. The present study investigated the annualized rate of GM atrophy in a large sample of older participants, focusing on the hippocampus, and searching for modulation by age and sex. In this 4-year longitudinal community cohort study, we used a VBM analysis to estimate the annualized rate of GM loss, at both the global and regional levels, in 1,172 healthy older adults (65–82 years) scanned at 1.5T. The global annualized rate of GM was −4.0 cm3/year (−0.83%/year). The highest rates of regional GM loss were found in the frontal and parietal cortices, middle occipital gyri, temporal cortex and hippocampus. The rate of GM atrophy was higher in women (−4.7 cm3/year, −0.91%/year) than men (−3.3 cm3/year, −0.65%/year). The global annualized rate of GM atrophy remained constant throughout the age range of the cohort, in both sexes. This pattern was replicated at the regional level, with the exception of the hippocampi, which showed a rate of GM atrophy that accelerated with age (2.8%/year per year of age) similarly for men and women. The present study reports a global and regional description of the annualized rate of grey matter loss and its evolution after the age of 65. Our results suggest greater anatomical vulnerability of women in late life and highlight a specific vulnerability of the hippocampus to the aging processes after 65 years of age. PMID:25469789

  13. Age-specific responses to spring temperature in a migratory songbird: older females attempt more broods in warmer springs

    PubMed Central

    Bulluck, L; Huber, S; Viverette, C; Blem, C

    2013-01-01

    Increasing global temperature has led to an interest in plasticity in the timing of annual events; however, little is known about the demographic consequences of changing phenology. Annual reproductive success varies significantly among individuals within a population, and some of that variation has to do with the number of broods attempted by reproducing adults. In birds, female age and the timing of reproduction are often predictors of multiple breeding. We hypothesize that double brooding rates may be affected by spring temperature and that the response may vary with female age. We used a long-term reproductive data set for a migratory songbird, the prothonotary warbler (Protonotaria citrea) to assess which factors influence (a) an individual female's probability of double brooding and (b) the annual variation in population-level double brooding rates. We found that older and earlier nesting birds are more likely to double brood, and that there is no evidence for senescence with regard to this trait such that the oldest females were most likely to double brood. Previous experience with double brooding (i.e., whether the female double brooded in the previous year) significantly increased the probability of doing so again. When assessing annual variation in the double brooding rate, we found an interaction between spring temperature and the proportion of older females in the population. Specifically, older females are more likely to double brood in years with warmer springs, but this relationship was not seen for younger females. Previous studies have shown that warmer temperatures lead to earlier and narrower peaks in resources and we hypothesize that these peaks are more available to older and earlier arriving females, enabling them to successfully raise more than one brood in a season. Understanding how different age classes respond to changing environmental conditions will be imperative to managing declining species. PMID:24223269

  14. Age-specific survival and philopatry in three species of European ducks: a long-term study

    USGS Publications Warehouse

    Blums, P.; Mednis, A.; Bauga, I.; Nichols, J.D.; Hines, J.E.

    1996-01-01

    Capture-recapture and band recovery models were used to estimate age-specific survival probabilities for female Northern Shovelers (Anas clypeata), Common Pochards (Aythya ferina), and Tufted Ducks (Aythya.fuligula) at Engure Marsh, Latvia, in 1964-1993. We banded more than 65,100 day-old ducklings of both sexes and captured 10,211 incubating females (3,713 new bandings and 6,498 recaptures). We developed a set of 3-age capture-recapture models to estimate annual survival rates for female ducklings, yearlings (SY), and adults (ASY) using programs SURGE and SURVIV and selected parsimonious models using a method developed bv Akaike (1973). Survival rates of SY and ASY females were highest-for Tufted Ducks intermediate for Common Pochards, and lowest for Northern Shovelers. Survival rates of SY and ASY females varied in parallel for shovelers and pochards. We believe that much of the difference in survival estimates between SY and ASY birds was caused by mortality rather than permanent emigration. Estimates of day-old duckling survival, reflecting both mortality and permanent emigration, were 0.12 for shoveler, 0.06 for pochard, and 0.03 for Tufted Duck. For all species, duckling survival varied over years, but the pattern of variation was not similar to that of the other age classes. Estimates of survival using band recovery data for SY + ASY female pochards and Tufted Ducks were similar to the capture-recapturee stimates, suggestingt hat surviving females returned to the breeding marsh with probabilities approaching 1.

  15. Updating UK estimates of age, sex and period specific cumulative constant tar cigarette consumption per adult

    PubMed Central

    Forey, B.; Lee, P.; Fry, J.

    1998-01-01

    BACKGROUND—In 1993 we presented age and sex specific estimates of cumulative constant tar cigarette consumption (CCTCC) per adult for five year periods to 1986-90. These were derived from annual surveys conducted for the Tobacco Manufacturers' Association (TMA) since 1946, extrapolated back to 1891 for men and to 1921 for women and corrected for the decline in average (machine smoked) tar levels. We now provide estimates for 1991-5.
METHODS—TMA surveys having ceased, 1991-5 estimates of manufactured cigarette consumption per adult (MCA) were derived from the General Household Survey (GHS) and corrected for the continuing decline in tar. These estimates were divided by 0.75 (men) and 0.80 (women), based on a comparison of GHS and TMA data for 1971-90, to allow accumulation with the TMA derived estimates prior to 1991.
RESULTS—For both sexes the GHS/TMA ratio of MCA varied little by age or five year period, justifying the use of the correction factors when adjusting GHS estimates for 1991-95. TMA estimates were higher than GHS estimates as only TMA sales-corrected their data for understatement of smoking and the surveys differed in questions on handrolled cigarette smoking. The 1991-95 data confirm the continuing decline in CCTCC at all ages in men. Women show a less steep decline for ages 30-64 and an increase for ages 65-84.
CONCLUSION—The GHS data can validly be used to update the CCTCC estimates. Some reservations about the use of CCTCC are discussed.

 PMID:10193376

  16. Reference Ranges of Age-Related Prostate-Specific Antigen in Men without Cancer from Beijing Area

    PubMed Central

    Liu, Xin; Wang, Jie; Zhang, Shun-Xin; Lin, Qian

    2013-01-01

    Abstract Background To determine the normal ranges of serum age-related prostate-specific antigen (PSA) level in men from Beijing area without cancer. Methods In this cross sectional study, form April 2010 to October 2011, 1611 healthy men undergoing a routine health check-up in our hospital and all men received three examinations including serum PSA test, digital rectal ex-amination and transrectal ultrasound. Men with any two abnormal results of the three examinations were undergone a prostate biopsy. Men with any two normal results of the three examinations or with negative biopsy were defined as men without cancer. Men with a prior history of prostate cancer/surgery or with urinary tract infection/obstruction were excluded. 1572 men without cancer were recruited into the study finally and were stratified into 10-year age groups: 40 to 49, 50 to 59, 60 to 69, 70 to 79, and older than 80. Results The median PSA value (95th percentile range) was 0.506(1.565), 1.04(2.920), 1.16(4.113), 1.34(5.561)and 2.975 (7.285) for each age group respectively, and the 25th percentile to 75 percentile was 0.343 to 0.923, 0.663 to 1.580, 0.693 to 2.203, 0.789 to 2.368 and 1.188 to 4.295 respectively. The serum PSA value is directly correlated with age (r=0.314, P<0.001). Conclusions Use the age-related range for PSA increases the sensitivity in younger men and decreases the biopsy rate in older patients. PMID:26171333

  17. The Aging Males' Symptoms rating scale: cultural and linguistic validation into Thai.

    PubMed

    Leungwattanakij, Somboon; Lersithichai, Panuwat; Ratana-Olarn, Krisda

    2003-12-01

    The interest in clinically investigating the health-related quality of life and symptoms of aging males has increased in recent years. Recently, a couple of validated questionnaires have been proposed for either screening, diagnosing and assessing response to therapy. Among these, the Aging Males' Symptom (AMS) questionnaire has been one of the most accepted questionnaires used in aging male clinics worldwide. The AMS questionnaire was originally developed and standardized in Germany in accordance with psychometric tests, and translated into English. The objective of this study was to develop the Thai AMS questionnaire, which is culturally and linguistically validated, and to present the translation process from English to Thai. The translation for the Thai speaking culture was planned specifically for use in Thailand. The forward translation into Thai was performed independently by two Thai-English translators with clinical experience in the aging male field. Another two Thai-English translators performed the back translation into English. Reconciliation of problematic items or explanations with the investigators was performed point by point to get the final version. The test and retest of Thai AMS questionnaire were performed within the time interval of 14 days by 20 Thai men aged 41-62 who came from different social classes and had various levels of education. The correlation between the first and the second questionnaires was statistically analyzed using Pearson correlation coefficient (r). The results of the linguistic and cultural adaptation of the English AMS scale led to a Thai AMS questionnaire. The results of the test and retest reliability demonstrated good correlation and were promising (r = 0.87). Therefore, this scale can be used as a valuable tool for assessing symptoms in the aging males in Thailand.

  18. Strong evidence for lineage and sequence specificity of substitution rates and patterns in Drosophila.

    PubMed

    Singh, Nadia D; Arndt, Peter F; Clark, Andrew G; Aquadro, Charles F

    2009-07-01

    Rates of single nucleotide substitution in Drosophila are highly variable within the genome, and several examples illustrate that evolutionary rates differ among Drosophila species as well. Here, we use a maximum likelihood method to quantify lineage-specific substitutional patterns and apply this method to 4-fold degenerate synonymous sites and introns from more than 8,000 genes aligned in the Drosophila melanogaster group. We find that within species, different classes of sequence evolve at different rates, with long introns evolving most slowly and short introns evolving most rapidly. Relative rates of individual single nucleotide substitutions vary approximately 3-fold among lineages, yielding patterns of substitution that are comparatively less GC-biased in the melanogaster species complex relative to Drosophila yakuba and Drosophila erecta. These results are consistent with a model coupling a mutational shift toward reduced GC content, or a shift in mutation-selection balance, in the D. melanogaster species complex, with variation in selective constraint among different classes of DNA sequence. Finally, base composition of coding and intronic sequences is not at equilibrium with respect to substitutional patterns, which primarily reflects the slow rate of the substitutional process. These results thus support the view that mutational and/or selective processes are labile on an evolutionary timescale and that if the process is indeed selection driven, then the distribution of selective constraint is variable across the genome.

  19. Quasi-static magnetic measurements to predict specific absorption rates in magnetic fluid hyperthermia experiments

    NASA Astrophysics Data System (ADS)

    Coral, D. F.; Mendoza Zélis, P.; de Sousa, M. E.; Muraca, D.; Lassalle, V.; Nicolás, P.; Ferreira, M. L.; Fernández van Raap, M. B.

    2014-01-01

    In this work, the issue on whether dynamic magnetic properties of polydispersed magnetic colloids modeled using physical magnitudes derived from quasi-static magnetic measurement can be extrapolated to analyze specific absorption rate data acquired at high amplitudes and frequencies of excitation fields is addressed. To this end, we have analyzed two colloids of magnetite nanoparticles coated with oleic acid and chitosan in water displaying, under a radiofrequency field, high and low specific heat power release. Both colloids are alike in terms of liquid carrier, surfactant and magnetic phase composition but differ on the nanoparticle structuring. The colloid displaying low specific dissipation consists of spaced magnetic nanoparticles of mean size around 4.8 nm inside a large chitosan particle of 52.5 nm. The one displaying high specific dissipation consists of clusters of magnetic nanoparticles of mean size around 9.7 nm inside a chitosan particle of 48.6 nm. The experimental evaluation of Néel and Brown relaxation times (˜10-10 s and 10-4 s, respectively) indicate that the nanoparticles in both colloids magnetically relax by Néel mechanism. The isothermal magnetization curves analysis for this mechanism show that the magnetic nanoparticles behave in the interacting superparamagnetic regime. The specific absorption rates were determined calorimetrically at 260 kHz and up to 52 kA/m and were well modeled within linear response theory using the anisotropy density energy retrieved from quasi-static magnetic measurement, validating their use to predict heating ability of a given polydispersed particle suspension. Our findings provide new insight in the validity of quasi-static magnetic characterization to analyze the high frequency behavior of polydispersed colloids within the framework of the linear response and Wohlfarth theories and indicate that dipolar interactions play a key role being their strength larger for the colloid displaying higher dissipation, i

  20. Single-nephron filtration rate and proximal reabsorption in aging rats.

    PubMed

    Corman, B; Roinel, N

    1991-01-01

    Age-related changes in the function of individual nephrons were investigated by micropuncture experiments measuring single-nephron filtration rates (SNGFR) and proximal reabsorptions in 10-, 20-, and 30-mo-old rats. The animals were female WAG/Rij rats with low incidence of chronic progressive nephropathy, no loss of nephrons, and renal hypertrophy of both kidneys in the oldest animals. Mean SNGFR values per gram kidney weight were 41.4 +/- 1.1, 37.1 +/- 1.5, and 32.2 +/- 1.1 nl.min-1.g kidney wt-1 (n = 41) in the 10-, 20-, and 30-mo-old animals, respectively. This age-related decrease in filtration was no longer apparent when SNGFR values were expressed per nephron (means 24.3 +/- 0.7, 23.7 +/- 0.9, and 24.4 +/- 0.9 nl/min. Individual filtered loads of sodium, potassium, calcium, and magnesium and their absolute reabsorption by the proximal tubule were not different in the three age groups; however, absolute and fractional reabsorptions of phosphate decreased significantly in the 30-mo-old rats. These results indicate that, with the exception of phosphate, individual filtrations and proximal reabsorptions are well maintained in aging rats free of disease. This may be related to the observed renal hypertrophy. PMID:1992782

  1. A Bayesian Approach to Inferring Rates of Selfing and Locus-Specific Mutation.

    PubMed

    Redelings, Benjamin D; Kumagai, Seiji; Tatarenkov, Andrey; Wang, Liuyang; Sakai, Ann K; Weller, Stephen G; Culley, Theresa M; Avise, John C; Uyenoyama, Marcy K

    2015-11-01

    We present a Bayesian method for characterizing the mating system of populations reproducing through a mixture of self-fertilization and random outcrossing. Our method uses patterns of genetic variation across the genome as a basis for inference about reproduction under pure hermaphroditism, gynodioecy, and a model developed to describe the self-fertilizing killifish Kryptolebias marmoratus. We extend the standard coalescence model to accommodate these mating systems, accounting explicitly for multilocus identity disequilibrium, inbreeding depression, and variation in fertility among mating types. We incorporate the Ewens sampling formula (ESF) under the infinite-alleles model of mutation to obtain a novel expression for the likelihood of mating system parameters. Our Markov chain Monte Carlo (MCMC) algorithm assigns locus-specific mutation rates, drawn from a common mutation rate distribution that is itself estimated from the data using a Dirichlet process prior model. Our sampler is designed to accommodate additional information, including observations pertaining to the sex ratio, the intensity of inbreeding depression, and other aspects of reproduction. It can provide joint posterior distributions for the population-wide proportion of uniparental individuals, locus-specific mutation rates, and the number of generations since the most recent outcrossing event for each sampled individual. Further, estimation of all basic parameters of a given model permits estimation of functions of those parameters, including the proportion of the gene pool contributed by each sex and relative effective numbers. PMID:26374460

  2. Jumping Stand Apparatus Reveals Rapidly Specific Age-Related Cognitive Impairments in Mouse Lemur Primates.

    PubMed

    Picq, Jean-Luc; Villain, Nicolas; Gary, Charlotte; Pifferi, Fabien; Dhenain, Marc

    2015-01-01

    The mouse lemur (Microcebus murinus) is a promising primate model for investigating normal and pathological cerebral aging. The locomotor behavior of this arboreal primate is characterized by jumps to and from trunks and branches. Many reports indicate insufficient adaptation of the mouse lemur to experimental devices used to evaluate its cognition, which is an impediment to the efficient use of this animal in research. In order to develop cognitive testing methods appropriate to the behavioral and biological traits of this species, we adapted the Lashley jumping stand apparatus, initially designed for rats, to the mouse lemur. We used this jumping stand apparatus to compare performances of young (n = 12) and aged (n = 8) adults in acquisition and long-term retention of visual discriminations. All mouse lemurs completed the tasks and only 25 trials, on average, were needed to master the first discrimination problem with no age-related differences. A month later, all mouse lemurs made progress for acquiring the second discrimination problem but only the young group reached immediately the criterion in the retention test of the first discrimination problem. This study shows that the jumping stand apparatus allows rapid and efficient evaluation of cognition in mouse lemurs and demonstrates that about half of the old mouse lemurs display a specific deficit in long-term retention but not in acquisition of visual discrimination.

  3. Age- and sex-specific mortality and population structure in sea otters

    USGS Publications Warehouse

    Bodkin, J.L.; Burdin, A.M.; Ryazanov, D.A.

    2000-01-01

    We used 742 beach-cast carcasses to characterize age- and sex-specific sea otter mortality during the winter of 1990-1991 at Bering Island, Russia. We also examined 363 carcasses recovered after the 1989 grounding of the T/V Exxon Valdez, to characterize age and sex composition in the living western Prince William Sound (WPWS) sea otter population. At Bering Island, mortality was male-biased (81%), and 75% were adults. The WPWS population was female-biased (59%) and most animals were subadult (79% of the males and 45% of the females). In the decade prior to 1990-1991 we found increasing sea otter densities (particularly among males), declining prey resources, and declining weights in adult male sea otters at Bering Island. Our findings suggest the increased mortality at Bering Island in 1990-1991 was a density-dependent population response. We propose male-maintained breeding territories and exclusion of juvenile females by adult females, providing a mechanism for potentially moderating the effects of prey reductions on the female population. Increased adult male mortality at Bearing Island in 1990-1991 likely modified the sex and age class structure there toward that observed in Prince William Sound.

  4. Jumping Stand Apparatus Reveals Rapidly Specific Age-Related Cognitive Impairments in Mouse Lemur Primates

    PubMed Central

    Picq, Jean-Luc; Villain, Nicolas; Gary, Charlotte; Pifferi, Fabien; Dhenain, Marc

    2015-01-01

    The mouse lemur (Microcebus murinus) is a promising primate model for investigating normal and pathological cerebral aging. The locomotor behavior of this arboreal primate is characterized by jumps to and from trunks and branches. Many reports indicate insufficient adaptation of the mouse lemur to experimental devices used to evaluate its cognition, which is an impediment to the efficient use of this animal in research. In order to develop cognitive testing methods appropriate to the behavioral and biological traits of this species, we adapted the Lashley jumping stand apparatus, initially designed for rats, to the mouse lemur. We used this jumping stand apparatus to compare performances of young (n = 12) and aged (n = 8) adults in acquisition and long-term retention of visual discriminations. All mouse lemurs completed the tasks and only 25 trials, on average, were needed to master the first discrimination problem with no age-related differences. A month later, all mouse lemurs made progress for acquiring the second discrimination problem but only the young group reached immediately the criterion in the retention test of the first discrimination problem. This study shows that the jumping stand apparatus allows rapid and efficient evaluation of cognition in mouse lemurs and demonstrates that about half of the old mouse lemurs display a specific deficit in long-term retention but not in acquisition of visual discrimination. PMID:26716699

  5. [Age-related changes in the rat lacrimal gland: specific morphology and unknown nature].

    PubMed

    Gancharova, O S; Manskikh, V N

    2014-01-01

    The rat lacrimal apparatus includes several glands; among them, the exorbital gland plays the central role. Its parenchyma and stroma undergo prominent morphologic changes with age. The parenchymal transformation includes metaplasia of some of its acini and their turning into Harderian gland-like structures (harderization), accumulation of gland ducts ("ductularization"), and morphologic dysplasia-cytomegaly, karyomegaly, and'cell and nuclearpolymorphism in the other part of acini. All these transformations are hormone-dependent andsex-specific: theyoften appear in males. On the final stages of age-related transformations, the lacrimal gland tissue is morphologically similar to the neoplasm and has neoplastic morphology but no other features of a tumor. Therefore, the rat lacrimal gland is an interesting object to study tissue and cell atypia. In the rat glandular stroma, lymphocytic infiltration and fibrosis appear with age; these changes are similar to processes taking place in human lacrimal apparatus involved in the pathogenesis of senile dry eye syndrome. The spontaneous changes in the rat lacrimal gland, predominantly in male rats, can be used as a model of the human lacrimal apparatus disorders.

  6. Pharmacokinetics of digoxin-specific Fab: effects of decreased renal function and age

    PubMed Central

    Renard, C.; Grene-Lerouge, N.; Beau, N.; Baud, F.; Scherrmann, J. M.

    1997-01-01

    Aims To study the influence of age and renal function on digoxin-specific Fab (DS-Fab) pharmacokinetics. Methods Sixteen patients (35–91 years) with creatinine clearance ranging from 10.6 to 122.1 ml min−1 who had been admitted to hospital with severe digoxin or digitoxin self-poisoning were treated with DS-Fab (80 to 800 mg). Plasma DS-Fab concentrations were determined by radioimmunoassay. Results The mean (±s.d.) distribution and elimination half-lives, apparent volume of distribution and total body clearance were 1.1±0.4 h, 20.2±7.3 h, 13.1±5.8 l, and 17.6±10.8 ml min−1, respectively. Interindividual variability of DS-Fab total body clearance was linked linearly with the decrease in creatinine clearance or with the increase in age and DS-Fab distribution volume was not dependent on creatinine clearance or age. Conclusions The data suggest that DS-Fab should be given to elderly and renal-impaired patients at doses similar to those given to younger or normal renal function patients. PMID:9278197

  7. Jumping Stand Apparatus Reveals Rapidly Specific Age-Related Cognitive Impairments in Mouse Lemur Primates.

    PubMed

    Picq, Jean-Luc; Villain, Nicolas; Gary, Charlotte; Pifferi, Fabien; Dhenain, Marc

    2015-01-01

    The mouse lemur (Microcebus murinus) is a promising primate model for investigating normal and pathological cerebral aging. The locomotor behavior of this arboreal primate is characterized by jumps to and from trunks and branches. Many reports indicate insufficient adaptation of the mouse lemur to experimental devices used to evaluate its cognition, which is an impediment to the efficient use of this animal in research. In order to develop cognitive testing methods appropriate to the behavioral and biological traits of this species, we adapted the Lashley jumping stand apparatus, initially designed for rats, to the mouse lemur. We used this jumping stand apparatus to compare performances of young (n = 12) and aged (n = 8) adults in acquisition and long-term retention of visual discriminations. All mouse lemurs completed the tasks and only 25 trials, on average, were needed to master the first discrimination problem with no age-related differences. A month later, all mouse lemurs made progress for acquiring the second discrimination problem but only the young group reached immediately the criterion in the retention test of the first discrimination problem. This study shows that the jumping stand apparatus allows rapid and efficient evaluation of cognition in mouse lemurs and demonstrates that about half of the old mouse lemurs display a specific deficit in long-term retention but not in acquisition of visual discrimination. PMID:26716699

  8. Tissue-specific autophagy responses to aging and stress in C. elegans.

    PubMed

    Chapin, Hannah C; Okada, Megan; Merz, Alexey J; Miller, Dana L

    2015-06-01

    Cellular function relies on a balance between protein synthesis and breakdown. Macromolecular breakdown through autophagy is broadly required for cellular and tissue development, function, and recovery from stress. While Caenorhabditis elegans is frequently used to explore cellular responses to development and stress, the most common assays for autophagy in this system lack tissue-level resolution. Different tissues within an organism have unique functional characteristics and likely vary in their reliance on autophagy under different conditions. To generate a tissue-specific map of autophagy in C. elegans we used a dual fluorescent protein (dFP) tag that releases monomeric fluorescent protein (mFP) upon arrival at the lysosome. Tissue-specific expression of dFP::LGG-1 revealed autophagic flux in all tissues, but mFP accumulation was most dramatic in the intestine. We also observed variable responses to stress: starvation increased autophagic mFP release in all tissues, whereas anoxia primarily increased intestinal autophagic flux. We observed autophagic flux with tagged LGG-1, LGG-2, and two autophagic cargo reporters: a soluble cytoplasmic protein, and mitochondrial TOMM-7. Finally, an increase in mFP in older worms was consistent with an age-dependent shift in proteostasis. These novel measures of autophagic flux in C. elegans reveal heterogeneity in autophagic response across tissues during stress and aging.

  9. Diversity of burial rates in convergent settings decreased as Earth aged.

    PubMed

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-01-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth's geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma(-1)) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision. PMID:27216133

  10. Diversity of burial rates in convergent settings decreased as Earth aged.

    PubMed

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-05-24

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth's geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma(-1)) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision.

  11. Diversity of burial rates in convergent settings decreased as Earth aged

    PubMed Central

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-01-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth’s geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma−1) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision. PMID:27216133

  12. Diversity of burial rates in convergent settings decreased as Earth aged

    NASA Astrophysics Data System (ADS)

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-05-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth’s geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma‑1) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision.

  13. Diversity of burial rates in convergent settings decreased as Earth aged

    NASA Astrophysics Data System (ADS)

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-05-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth’s geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma-1) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision.

  14. Occupational exposure and 25-year incidence rate of non-specific lung disease: the Zutphen Study.

    PubMed

    Heederik, D; Kromhout, H; Burema, J; Biersteker, K; Kromhout, D

    1990-12-01

    Information gathered in the Zutphen Study, the Dutch contribution to the Seven Countries Study that started in the 1960s, was used for the present study. In 1960 878 men participated in the physical examination and they were followed for 25 years until 1 July 1985. During this follow-up, their morbidity status was verified regularly. With this information the occurrence of chronic non-specific lung disease (CNSLD) at a specific time was coded by one physician, using strict criteria. The CNSLD diagnosis was based on the following criteria: episodes of respiratory symptoms such as regular cough and phlegm for longer than three months or episodes of wheezing and shortness of breath reported to the survey physician, or: diagnosis of CNSLD, including chronic bronchitis or emphysema by a clinical specialist. Occupation in 1960 was coded and used to generate specific occupational exposures with a Job Exposure Matrix. Because the exact time of diagnosis of CNSLD was known, incidence densities could be calculated. For 804 men a complete set of data was available. A Poisson regression analysis was used to analyse the relationships between the incidence density and independent variables like age, calendar period, occupation and specific occupational exposures. Blue collar workers had a significantly elevated incidence density ratio (IDR) compared to white collar workers (1.82, 95% confidence limits (CL): 1.35, 2.46). Subgroups of blue collar workers, wood and paper workers, textile workers, and tailors, construction workers and transport workers had significantly elevated IDRs also. Of the specific exposures heavy metals, mineral dust and adhesives had a significantly elevated IDR.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2084026

  15. Incorporating harvest rates into the sex-age-kill model for white-tailed deer

    USGS Publications Warehouse

    Norton, Andrew S.; Diefenbach, Duane R.; Rosenberry, Christopher S.; Wallingford, Bret D.

    2013-01-01

    Although monitoring population trends is an essential component of game species management, wildlife managers rarely have complete counts of abundance. Often, they rely on population models to monitor population trends. As imperfect representations of real-world populations, models must be rigorously evaluated to be applied appropriately. Previous research has evaluated population models for white-tailed deer (Odocoileus virginianus); however, the precision and reliability of these models when tested against empirical measures of variability and bias largely is untested. We were able to statistically evaluate the Pennsylvania sex-age-kill (PASAK) population model using realistic error measured using data from 1,131 radiocollared white-tailed deer in Pennsylvania from 2002 to 2008. We used these data and harvest data (number killed, age-sex structure, etc.) to estimate precision of abundance estimates, identify the most efficient harvest data collection with respect to precision of parameter estimates, and evaluate PASAK model robustness to violation of assumptions. Median coefficient of variation (CV) estimates by Wildlife Management Unit, 13.2% in the most recent year, were slightly above benchmarks recommended for managing game species populations. Doubling reporting rates by hunters or doubling the number of deer checked by personnel in the field reduced median CVs to recommended levels. The PASAK model was robust to errors in estimates for adult male harvest rates but was sensitive to errors in subadult male harvest rates, especially in populations with lower harvest rates. In particular, an error in subadult (1.5-yr-old) male harvest rates resulted in the opposite error in subadult male, adult female, and juvenile population estimates. Also, evidence of a greater harvest probability for subadult female deer when compared with adult (≥2.5-yr-old) female deer resulted in a 9.5% underestimate of the population using the PASAK model. Because obtaining

  16. Construction Industry Apprentices' Substance Use: A Survey of Prevalence Rates, Reasons for Use, and Regional and Age Differences

    ERIC Educational Resources Information Center

    du Plessis, Karin; Corney, Tim

    2011-01-01

    Prevalence rates and reasons for substance use were studied in a sample of 172 male construction industry apprentices who had a mean age of 20 years. Results were compared with those of men in similar age groups in Victoria, and regional and age differences were explored. Findings indicate that more metropolitan apprentices had experimented with…

  17. Effects of Age, Exercise Duration, and Test Conditions on Heart Rate Variability in Young Endurance Horses.

    PubMed

    Younes, Mohamed; Robert, Céline; Barrey, Eric; Cottin, François

    2016-01-01

    Although cardiac recovery is an important criterion for ranking horses in endurance competitions, heart rate variability (HRV) has hardly ever been studied in the context of this equestrian discipline. In the present study, we sought to determine whether HRV is affected by parameters such as age, exercise duration and test site. Accordingly, HRV might be used to select endurance horses with the fastest cardiac recovery. The main objective of the present study was to determine the effects of age, exercise duration, and test site on HRV variables at rest and during exercise and recovery in young Arabian endurance horses. Over a 3-year period, 77 young Arabian horses aged 4-6 years performed one or more exercise tests (consisting of a warm-up, cantering at 22 km.h(-1)and a final 500 m gallop at full speed) at four different sites. Beat-to-beat RR intervals were continuously recorded and then analyzed (using a time-frequency approach) to determine the instantaneous HRV components before, during and after the test. At rest, the root-mean-square of successive differences in RR intervals (RMSSD) was higher in the 4-year-olds (54.4 ± 14.5 ms) than in the 5-or 6-year-olds (44.9 ± 15.5 and 49.1 ± 11.7 ms, respectively). During the first 15 min of exercise (period T), the heart rate (HR) and RMSSD decreased with age. In 6-year-olds, RMSSD decreased as the exercise duration increased (T: 3.0 ± 1.4 vs. 2T: 3.6 ± 2.2 vs. 3T: 2.8 ± 1.0). During recovery, RMSSD was negatively correlated with the cardiac recovery time (CRT) and the recovery heart rate (RHR; R = -0.56 and -0.53, respectively; p < 0.05). At rest and during exercise and recovery, RMSSD and several HRV variables differed significantly as a function of the test conditions. HRV in endurance horses appears to be strongly influenced by age and environmental factors (such as ambient temperature, ambient humidity, and track quality). Nevertheless, RMSSD can be used to select endurance horses with the fastest cardiac

  18. Effects of Age, Exercise Duration, and Test Conditions on Heart Rate Variability in Young Endurance Horses.

    PubMed

    Younes, Mohamed; Robert, Céline; Barrey, Eric; Cottin, François

    2016-01-01

    Although cardiac recovery is an important criterion for ranking horses in endurance competitions, heart rate variability (HRV) has hardly ever been studied in the context of this equestrian discipline. In the present study, we sought to determine whether HRV is affected by parameters such as age, exercise duration and test site. Accordingly, HRV might be used to select endurance horses with the fastest cardiac recovery. The main objective of the present study was to determine the effects of age, exercise duration, and test site on HRV variables at rest and during exercise and recovery in young Arabian endurance horses. Over a 3-year period, 77 young Arabian horses aged 4-6 years performed one or more exercise tests (consisting of a warm-up, cantering at 22 km.h(-1)and a final 500 m gallop at full speed) at four different sites. Beat-to-beat RR intervals were continuously recorded and then analyzed (using a time-frequency approach) to determine the instantaneous HRV components before, during and after the test. At rest, the root-mean-square of successive differences in RR intervals (RMSSD) was higher in the 4-year-olds (54.4 ± 14.5 ms) than in the 5-or 6-year-olds (44.9 ± 15.5 and 49.1 ± 11.7 ms, respectively). During the first 15 min of exercise (period T), the heart rate (HR) and RMSSD decreased with age. In 6-year-olds, RMSSD decreased as the exercise duration increased (T: 3.0 ± 1.4 vs. 2T: 3.6 ± 2.2 vs. 3T: 2.8 ± 1.0). During recovery, RMSSD was negatively correlated with the cardiac recovery time (CRT) and the recovery heart rate (RHR; R = -0.56 and -0.53, respectively; p < 0.05). At rest and during exercise and recovery, RMSSD and several HRV variables differed significantly as a function of the test conditions. HRV in endurance horses appears to be strongly influenced by age and environmental factors (such as ambient temperature, ambient humidity, and track quality). Nevertheless, RMSSD can be used to select endurance horses with the fastest cardiac

  19. Effects of Age, Exercise Duration, and Test Conditions on Heart Rate Variability in Young Endurance Horses

    PubMed Central

    Younes, Mohamed; Robert, Céline; Barrey, Eric; Cottin, François

    2016-01-01

    Although cardiac recovery is an important criterion for ranking horses in endurance competitions, heart rate variability (HRV) has hardly ever been studied in the context of this equestrian discipline. In the present study, we sought to determine whether HRV is affected by parameters such as age, exercise duration and test site. Accordingly, HRV might be used to select endurance horses with the fastest cardiac recovery. The main objective of the present study was to determine the effects of age, exercise duration, and test site on HRV variables at rest and during exercise and recovery in young Arabian endurance horses. Over a 3-year period, 77 young Arabian horses aged 4–6 years performed one or more exercise tests (consisting of a warm-up, cantering at 22 km.h−1and a final 500 m gallop at full speed) at four different sites. Beat-to-beat RR intervals were continuously recorded and then analyzed (using a time-frequency approach) to determine the instantaneous HRV components before, during and after the test. At rest, the root-mean-square of successive differences in RR intervals (RMSSD) was higher in the 4-year-olds (54.4 ± 14.5 ms) than in the 5-or 6-year-olds (44.9 ± 15.5 and 49.1 ± 11.7 ms, respectively). During the first 15 min of exercise (period T), the heart rate (HR) and RMSSD decreased with age. In 6-year-olds, RMSSD decreased as the exercise duration increased (T: 3.0 ± 1.4 vs. 2T: 3.6 ± 2.2 vs. 3T: 2.8 ± 1.0). During recovery, RMSSD was negatively correlated with the cardiac recovery time (CRT) and the recovery heart rate (RHR; R = −0.56 and −0.53, respectively; p < 0.05). At rest and during exercise and recovery, RMSSD and several HRV variables differed significantly as a function of the test conditions. HRV in endurance horses appears to be strongly influenced by age and environmental factors (such as ambient temperature, ambient humidity, and track quality). Nevertheless, RMSSD can be used to select endurance horses with the fastest

  20. Growth Rate and Relocation Movements of Common Nighthawk (Chordeiles minor) Nestlings in Relation to Age

    USGS Publications Warehouse

    Kramer, Gunnar R.; Chalfoun, Anna D.

    2012-01-01

    Relocation by dependent young is a survival strategy that occurs among a wide range of taxa. The Common Nighthawk (Chordeiles minor) lays its eggs on bare substrate and, once hatched, nestlings may relocate to new sites daily. We located and monitored eight Common Nighthawk nests in Grand Teton National Park, Wyoming, quantified inter-use-site distances in relation to nestling age, and calculated a nestling growth rate curve. Common Nighthawk nestlings grow in a nearly linear fashion. Nestlings moved up to 48 m in a single day and larger, older nestlings tended to move greater distances between daily use-sites.

  1. Quantifying ages of river terraces and basin wide denudation rates in Pamir

    NASA Astrophysics Data System (ADS)

    Sulaymonova, Vasila A.; Fuchs, Margret C.; Gloaguen, Richard; Merchel, Silke; Rugel, Georg

    2014-05-01

    The Pamir is located at the western edge of the Indian indenter and results from the India-Asia collision. The Pamir also lies at the transition between zones dominated either by the Westerlies or the Indian Summer Monsoon. The ongoing tectonic deformation together with the climatic gradients from the two prevailing atmospheric circulation systems provide a natural laboratory to study surface processes and their rates. To determine and quantify the interaction between tectonics and the drainage system in the Tajik Pamir we use cosmogenic nuclide based techniques. We measured 10Be and 26Al concentrations of modern fluvial sediments sampled from drainage system of Pamirs. Depth profiles enable to determine exposure ages of fluvial terraces, while the modern river sediments reveal basin-wide erosion rates. However, accurate measurement results depend on the quality of the sample preparation. The samples from Pamir contain a high amount of various feldspars that are very difficult to separate from quartz using standard procedures such as magnetic or density separation. Unclean samples cause uncertainties in chemical procedures, especially in the case of combined 10Be and 26Al analysis. We developed a feldspar flotation in addition to our sample preparation procedure that allowed an almost complete separation of the quartz, up to 95%. Several depth profiles were analyzed to determine the exposure age of fluvial terraces. The first results of one terrace along the southern Panj River east of Langar, and one along the Shakhdara River are promising. The AMS results demonstrated that the depth profiles are consistent, with 10Be and 26Al concentrations decreasing with depth. The results of both fluvial terraces show similar denudation rates 0.5mm/yr., while exposure age analysis yields 3.5 ka for the Langar and 19 ka Shakhdara terrace. Further analyses are ongoing. These ages are validated by OSL dates at or nearby the same sites. 10Be denudation rates on modern river

  2. Specific Growth Rate Determines the Sensitivity of Escherichia coli to Thermal, UVA, and Solar Disinfection

    PubMed Central

    Berney, Michael; Weilenmann, Hans-Ulrich; Ihssen, Julian; Bassin, Claudio; Egli, Thomas

    2006-01-01

    Knowledge about the sensitivity of the test organism is essential for the evaluation of any disinfection method. In this work we show that sensitivity of Escherichia coli MG1655 to three physical stresses (mild heat, UVA light, and sunlight) that are relevant in the disinfection of drinking water with solar radiation is determined by the specific growth rate of the culture. Batch- and chemostat-cultivated cells from cultures with similar specific growth rates showed similar stress sensitivities. Generally, fast-growing cells were more sensitive to the stresses than slow-growing cells. For example, slow-growing chemostat-cultivated cells (D = 0.08 h−1) and stationary-phase bacteria from batch culture that were exposed to mild heat had very similar T90 (time until 90% of the population is inactivated) values (T90, chemostat = 2.66 h; T90, batch = 2.62 h), whereas T90 for cells growing at a μ of 0.9 h−1 was 0.2 h. We present evidence that the stress sensitivity of E. coli is correlated with the intracellular level of the alternative sigma factor RpoS. This is also supported by the fact that E. coli rpoS mutant cells were more stress sensitive than the parent strain by factors of 4.9 (mild heat), 5.3 (UVA light), and 4.1 (sunlight). Furthermore, modeling of inactivation curves with GInaFiT revealed that the shape of inactivation curves changed depending on the specific growth rate. Inactivation curves of cells from fast-growing cultures (μ = 1.0 h−1) that were irradiated with UVA light showed a tailing effect, while for slow-growing cultures (μ = 0.3 h−1), inactivation curves with shoulders were obtained. Our findings emphasize the need for accurate reporting of specific growth rates and detailed culture conditions in disinfection studies to allow comparison of data from different studies and laboratories and sound interpretation of the data obtained. PMID:16597961

  3. Residue-specific NH exchange rates studied by NMR diffusion experiments

    NASA Astrophysics Data System (ADS)

    Brand, Torsten; Cabrita, Eurico J.; Morris, Gareth A.; Günther, Robert; Hofmann, Hans-Jörg; Berger, Stefan

    2007-07-01

    We present a novel approach to the investigation of rapid (>2 s -1) NH exchange rates in proteins, based on residue-specific diffusion measurements. 1H, 15N-DOSY-HSQC spectra are recorded in order to observe resolved amide proton signals for most residues of the protein. Human ubiquitin was used to demonstrate the proposed method. Exchange rates are derived directly from the decay data of the diffusion experiment by applying a model deduced from the assumption of a two-site exchange with water and the "pure" diffusion coefficients of water and protein. The "pure" diffusion coefficient of the protein is determined in an experiment with selective excitation of the amide protons in order to suppress the influence of magnetization transfer from water to amide protons on the decay data. For rapidly exchanging residues a comparison of our results with the exchange rates obtained in a MEXICO experiment showed good agreement. Molecular dynamics (MD) and quantum mechanical calculations were performed to find molecular parameters correlating with the exchangeability of the NH protons. The RMS fluctuations of the amide protons, obtained from the MD simulations, together with the NH coupling constants provide a bilinear model which shows a good correlation with the experimental NH exchange rates.

  4. Ambulatory heart rate range predicts mode-specific mortality and hospitalisation in chronic heart failure

    PubMed Central

    Cubbon, Richard M; Ruff, Naomi; Groves, David; Eleuteri, Antonio; Denby, Christine; Kearney, Lorraine; Ali, Noman; Walker, Andrew M N; Jamil, Haqeel; Gierula, John; Gale, Chris P; Batin, Phillip D; Nolan, James; Shah, Ajay M; Fox, Keith A A; Sapsford, Robert J; Witte, Klaus K; Kearney, Mark T

    2016-01-01

    Objective We aimed to define the prognostic value of the heart rate range during a 24 h period in patients with chronic heart failure (CHF). Methods Prospective observational cohort study of 791 patients with CHF associated with left ventricular systolic dysfunction. Mode-specific mortality and hospitalisation were linked with ambulatory heart rate range (AHRR; calculated as maximum minus minimum heart rate using 24 h Holter monitor data, including paced and non-sinus complexes) in univariate and multivariate analyses. Findings were then corroborated in a validation cohort of 408 patients with CHF with preserved or reduced left ventricular ejection fraction. Results After a mean 4.1 years of follow-up, increasing AHRR was associated with reduced risk of all-cause, sudden, non-cardiovascular and progressive heart failure death in univariate analyses. After accounting for characteristics that differed between groups above and below median AHRR using multivariate analysis, AHRR remained strongly associated with all-cause mortality (HR 0.991/bpm increase in AHRR (95% CI 0.999 to 0.982); p=0.046). AHRR was not associated with the risk of any non-elective hospitalisation, but was associated with heart-failure-related hospitalisation. AHRR was modestly associated with the SD of normal-to-normal beats (R2=0.2; p<0.001) and with peak exercise-test heart rate (R2=0.33; p<0.001). Analysis of the validation cohort revealed AHRR to be associated with all-cause and mode-specific death as described in the derivation cohort. Conclusions AHRR is a novel and readily available prognosticator in patients with CHF, which may reflect autonomic tone and exercise capacity. PMID:26674986

  5. Variation in rates of early development in Haliotis asinina generate competent larvae of different ages

    PubMed Central

    2012-01-01

    Introduction Inter-specific comparisons of metazoan developmental mechanisms have provided a wealth of data concerning the evolution of body form and the generation of morphological novelty. Conversely, studies of intra-specific variation in developmental programs are far fewer. Variation in the rate of development may be an advantage to the many marine invertebrates that posses a biphasic life cycle, where fitness commonly requires the recruitment of planktonically dispersing larvae to patchily distributed benthic environments. Results We have characterised differences in the rate of development between individuals originating from a synchronised fertilisation event in the tropical abalone Haliotis asinina, a broadcast spawning lecithotrophic vetigastropod. We observed significant differences in the time taken to complete early developmental events (time taken to complete third cleavage and to hatch from the vitelline envelope), mid-larval events (variation in larval shell development) and late larval events (the acquisition of competence to respond to a metamorphosis inducing cue). We also provide estimates of the variation in maternally provided energy reserves that suggest maternal provisioning is unlikely to explain the majority of the variation in developmental rate we report here. Conclusions Significant differences in the rates of development exist both within and between cohorts of synchronously fertilised H. asinina gametes. These differences can be detected shortly after fertilisation and generate larvae of increasingly divergent development states. We discuss the significance of our results within an ecological context, the adaptive significance of mechanisms that might maintain this variation, and potential sources of this variation. PMID:22339806

  6. Measuring impulsivity in school-aged boys and examining its relationship with ADHD and ODD ratings.

    PubMed

    Avila, César; Cuenca, Isabel; Félix, Vicente; Parcet, Maria-Antònia; Miranda, Ana

    2004-06-01

    Seven different laboratory measures of impulsivity were administered to a group of 165 school-aged boys. Parents' and teachers' ratings of Attention Deficit and Hyperactivity Disorder and Oppositional/Defiant Disorder were also obtained. Factor analyses of impulsivity measures revealed the existence of a strong Inhibitory Control Factor including measures derived from Stop Task, the Continuous Performance Test, the Matching Familiar Figures Test, and the Circle Tracing Task. Other forms of impulsivity like resistance to interference, the Wisconsin Card Sorting Test and efficiency in the DRL Task loaded on a second independent factor. The Inhibitory Control factor was correlated with ADHD ratings, whereas the second factor was slightly related to the presence of ODD symptoms. Discussion is focused on the relevance of inhibitory control in impulsivity and ADHD research.

  7. Effects of age, replicative lifespan and growth rate of human nucleus pulposus cells on selecting age range for cell-based biological therapies for degenerative disc diseases.

    PubMed

    Lee, J S; Lee, S M; Jeong, S W; Sung, Y G; Lee, J H; Kim, K W

    2016-07-01

    Autologous disc cell implantation, growth factors and gene therapy appear to be promising therapies for disc regeneration. Unfortunately, the replicative lifespan and growth kinetics of human nucleus pulposus (NP) cells related to host age are unclear. We investigated the potential relations among age, replicative lifespan and growth rate of NP cells, and determined the age range that is suitable for cell-based biological therapies for degenerative disc diseases. We used NP tissues classified by decade into five age groups: 30s, 40s, 50s, 60s and 70s. The mean cumulative population doubling level (PDL) and population doubling rate (PDR) of NP cells were assessed by decade. We also investigated correlations between cumulative PDL and age, and between PDR and age. The mean cumulative PDL and PDR decreased significantly in patients in their 60s. The mean cumulative PDL and PDR in the younger groups (30s, 40s and 50s) were significantly higher than those in the older groups (60s and 70s). There also were significant negative correlations between cumulative PDL and age, and between PDR and age. We found that the replicative lifespan and growth rate of human NP cells decreased with age. The replicative potential of NP cells decreased significantly in patients 60 years old and older. Young individuals less than 60 years old may be suitable candidates for NP cell-based biological therapies for treating degenerative disc diseases.

  8. An age-specific kinetic model of lead metabolism in humans.

    PubMed Central

    Leggett, R W

    1993-01-01

    Although considerable progress has been made in recent years in reducing human exposures to lead, the potential for high intake of this contaminant still exists in millions of homes and in many occupational settings. Moreover, there is growing evidence that levels of lead intake considered inconsequential just a few years ago can result in subtle, adverse health effects, particularly in children. Consequently, there have been increased efforts by health protection agencies to develop credible, versatile methods for relating levels of lead in environmental media to levels in blood and tissues of exposed humans of all ages. In a parallel effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is assembling a set of age-specific biokinetic models for calculating radiation doses from environmentally important radionuclides, including radioisotopes of lead. This paper describes a new age-specific biokinetic model for lead originally developed for the ICRP but expanded to include additional features that are useful for consideration of lead as a chemical toxin. The model is developed within a generic, physiologically motivated framework designed to address a class of calciumlike elements. This framework provides a useful setting in which to synthesize experimental, occupational, and environmental data on lead and exploit common physiological properties of lead and the alkaline earth elements. The modular design is intended to allow researchers to modify specific parameter values or model components to address special problems in lead toxicology or to incorporate new information. Transport of lead between compartments is assumed to follow linear, first-order kinetics provided the concentration in red blood cells remains below a nonlinear threshold level, but a nonlinear relation between plasma lead and red blood cell lead is modeled for concentrations above that level. The model is shown to be consistent

  9. Comparison of the diagnostic accuracy, sensitivity and specificity of four odontological methods for age evaluation in Italian children at the age threshold of 14 years using ROC curves.

    PubMed

    Pinchi, Vilma; Pradella, Francesco; Vitale, Giulia; Rugo, Dario; Nieri, Michele; Norelli, Gian-Aristide

    2016-01-01

    The age threshold of 14 years is relevant in Italy as the minimum age for criminal responsibility. It is of utmost importance to evaluate the diagnostic accuracy of every odontological method for age evaluation considering the sensitivity, or the ability to estimate the true positive cases, and the specificity, or the ability to estimate the true negative cases. The research aims to compare the specificity and sensitivity of four commonly adopted methods of dental age estimation - Demirjian, Haavikko, Willems and Cameriere - in a sample of Italian children aged between 11 and 16 years, with an age threshold of 14 years, using receiver operating characteristic curves and the area under the curve (AUC). In addition, new decision criteria are developed to increase the accuracy of the methods. Among the four odontological methods for age estimation adopted in the research, the Cameriere method showed the highest AUC in both female and male cohorts. The Cameriere method shows a high degree of accuracy at the age threshold of 14 years. To adopt the Cameriere method to estimate the 14-year age threshold more accurately, however, it is suggested - according to the Youden index - that the decision criterion be set at the lower value of 12.928 for females and 13.258 years for males, obtaining a sensitivity of 85% and specificity of 88% in females, and a sensitivity of 77% and specificity of 92% in males. If a specificity level >90% is needed, the cut-off point should be set at 12.959 years (82% sensitivity) for females.

  10. Relationship of medical status, medications, and salivary flow rates in adults of different ages.

    PubMed

    Navazesh, M; Brightman, V J; Pogoda, J M

    1996-02-01

    Multiple systemic disorders and medications have been reported to cause xerostomia or salivary gland hypofunction. The purpose of this study was to evaluate the relationship among systemic disorders, medications, and salivary flow rates. Sixty-three ambulatory dental patients aged 23 to 82 years were randomly selected. The nature, duration, and number of systemic disorders and medications were documented. Repeated measurements of unstimulated whole, chewing-stimulated whole, acid-stimulated parotid, and candy-stimulated parotid salivary flow rates were obtained. Data were analyzed with the Wilcoxon rank-sum test, nonparametric multivariate analysis of variance, and Fisher's exact test. For persons with systemic disorders who were taking medication, all salivary flow rates were significantly (p = 0.03 - 0.001) lower than the flow rates in healthy persons. Among persons with at least one systemic disorder who were taking medication, those who had been taking medication for longer than 2 years had significantly lower unstimulated whole saliva (p = 0.002), chewing-stimulated whole saliva (p = 0.0004), and candy-stimulated parotid saliva (p = 0.02) flow rates than those who had been taking medication for 1 to 2 years. The number of systemic disorders significantly (p = 0.02) and negatively affected the acid-stimulated parotid salivary rates. The prevalence of salivary hypofunction determined on the basis of unstimulated whole saliva and acid-stimulated parotid saliva was significantly higher (p = < 0.001, p = 0.007) in the those persons with systemic disorders and taking medications. The results suggest that salivary secretion is affected by the number of systemic disorders and duration of the potentially xerogenic medications.

  11. Specific ion effects on the growth rates of Staphylococcus aureus and Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    Lo Nostro, Pierandrea; Ninham, Barry W.; Lo Nostro, Antonella; Pesavento, Giovanna; Fratoni, Laura; Baglioni, Piero

    2005-03-01

    Motivated by recent advances in the physical and chemical basis of the Hofmeister effect, we measured the rate cell growth of S. aureus—a halophilic pathogenic bacterium—and of P. aeruginosa, an opportunistic pathogen, in the presence of different aqueous salt solutions at different concentrations (0.2, 0.6 and 0.9 M). Microorganism growth rates depend strongly on the kind of anion in the growth medium. In the case of S. aureus, chloride provides a favorable growth medium, while both kosmotropes (water structure makers) and chaotropes (water structure breakers) reduce the microorganism growth. In the case of P. aeruginosa, all ions affect adversely the bacterial survival. In both cases, the trends parallel the specific ion, or Hofmeister, sequences observed in a wide range of physico-chemical systems. The correspondence with specific ion effect obtained in other studies, on the activities of a DNA restriction enzyme, of horseradish peroxidase, and of Lipase A (Aspergillus niger) is particularly striking. This work provides compelling evidence for Hofmeister effects, physical chemistry in action, in these organisms.

  12. The feasibility of age-specific travel restrictions during influenza pandemics

    PubMed Central

    2011-01-01

    Background Epidemiological studies have shown that imposing travel restrictions to prevent or delay an influenza pandemic may not be feasible. To delay an epidemic substantially, an extremely high proportion of trips (~99%) would have to be restricted in a homogeneously mixing population. Influenza is, however, strongly influenced by age-dependent transmission dynamics, and the effectiveness of age-specific travel restrictions, such as the selective restriction of travel by children, has yet to be examined. Methods A simple stochastic model was developed to describe the importation of infectious cases into a population and to model local chains of transmission seeded by imported cases. The probability of a local epidemic, and the time period until a major epidemic takes off, were used as outcome measures, and travel restriction policies in which children or adults were preferentially restricted were compared to age-blind restriction policies using an age-dependent next generation matrix parameterized for influenza H1N1-2009. Results Restricting children from travelling would yield greater reductions to the short-term risk of the epidemic being established locally than other policy options considered, and potentially could delay an epidemic for a few weeks. However, given a scenario with a total of 500 imported cases over a period of a few months, a substantial reduction in the probability of an epidemic in this time period is possible only if the transmission potential were low and assortativity (i.e. the proportion of contacts within-group) were unrealistically high. In all other scenarios considered, age-structured travel restrictions would not prevent an epidemic and would not delay the epidemic for longer than a few weeks. Conclusions Selectively restricting children from traveling overseas during a pandemic may potentially delay its arrival for a few weeks, depending on the characteristics of the pandemic strain, but could have less of an impact on the economy

  13. AgeStandardized Incidence Rates and Survival of Osteosarcoma in Northern Thailand.

    PubMed

    Pruksakorn, Dumnoensun; Phanphaisarn, Areerak; Pongnikorn, Donsuk; Daoprasert, Karnchana; Teeyakasem, Pimpisa; Chaiyawat, Parunya; Katruang, Narisara; Settakorn, Jongkolnee

    2016-01-01

    Osteosarcoma is a common primary malignant bone tumor in children and adolescents. Recent worldwide average incidences of osteosarcoma in people aged 0 to 24 years were 4.3 and 3.4 per million, respectively, with a ratio of 1.4:1. However, data on the incidence of osteosarcoma in Thailand are limited. This study analyzed the incidence of osteosarcoma in the upper northern region of Thailand, with a population of 5.85 million people (8.9% of the total Thai population), using data for the years 1998 to 2012, obtained from the Chiang Mai Cancer Registry (CMCR) at Chiang Mai University Hospital and the Lampang Cancer Registry (LCR) at the Lampang Cancer Hospital, a total of 144 cases. The overall annual incidence of osteosarcoma was 1.67 per million with a male:female ratio of 1.36:1. Incidences by age group (male and female) at 0 to 24, 25 to 59 and over 60 years were 3.5 (3.9 and 3.0), 0.8 (0.9 and 0.6), and 0.7 (0.8 and 0.5), respectively. The peak incidence occurred at 15 to 19 years for males and at 10 to 14 years for females. The median survival time was 18 months with a 5year survival rate of 43%. Neither the age group nor the 5year interval period of treatment was significantly correlated with survival during the 15year period studied. PMID:27509991

  14. Oxidative damage, skin aging, antioxidants and a novel antioxidant rating system.

    PubMed

    Palmer, Debbie M; Kitchin, Jennifer Silverman

    2010-01-01

    It is believed that oxidative stress is caused by an imbalance between the production of reactive oxygen and a biological system's ability to neutralize the reactive intermediates. Oxidative damage occurs because of both intrinsic and extrinsic mechanisms. Together, intrinsic and extrinsic damage are the primary causes of skin aging. The skin uses a series of intrinsic antioxidants to protect itself from free radical damage. Naturally occurring extrinsic antioxidants have also been widely shown to offset and alleviate these changes. Unlike sunscreens, which have an SPF rating system to guide consumers in their purchases, there is no widely accepted method to choose antioxidant anti-aging products. ORAC (Oxygen Radical Absorbance Capacity) and ABEL-RAC (Analysis By Emitted Light-Relative Antioxidant Capacity), are both accepted worldwide as a standard measure of the antioxidant capacity of foods, and are rating systems that could be applied to all antioxidant skincare products. The standardization of antioxidant creams could revolutionize the cosmeceutical market and give physicians and consumers the ability to compare and choose effectively.

  15. Incorporating Age-Specific Plans of Care to Achieve Optimal Perioperative Outcomes.

    PubMed

    Mower, Juliana

    2015-10-01

    When developing a nursing plan of care, a perioperative nurse identifies nursing diagnoses during the preoperative patient assessment. The ability to identify age-specific outcomes (ie, infant/child, adolescent, adult, elderly adult) in addition to those that are universally applicable is a major responsibility of the perioperative RN. Having an individualized plan of care is one of the best ways to determine whether desired patient outcomes have been successfully attained. Nursing care plans address intraoperative and postoperative risks and allow for a smooth transfer of care throughout the perioperative experience. A good nursing care plan also includes education for the patient and his or her caregiver. Within an overall plan of care, the use of methods such as a concept or mind map can visually demonstrate the relationships between systems, nursing diagnoses, nursing interventions, and desirable outcomes.

  16. Race-, gender- and age-specific differences in dietary micronutrient intakes of US children.

    PubMed

    Ganji, Vijay; Hampl, Jeffrey S; Betts, Nancy M

    2003-11-01

    Race-, gender- and age-specific differences in dietary micronutrient intakes of 1- to 10-year-old US children were evaluated. Three-day, dietary intakes from the US Department of Agriculture's Continuing Survey of Food Intakes by Individuals were evaluated. Data from 1895 children (967 males, 928 females; 1,540 Whites, 355 Blacks) who resided in the 48 conterminous states were analyzed. Micronutrient intakes, intakes as percent of the Recommended Dietary Allowance (RDA) and percent of children who consumed < or =67% of the RDA were computed. Black males compared with White males, Black females compared with White females and White females compared with White males had significantly lower dietary intakes for several micronutrients. More Black males than White males had intakes < or =67% of the RDA for vitamin E, calcium and zinc. Blacks and female children were at a greater risk for vitamin A, vitamin E, calcium, iron and zinc deficiency. PMID:14522694

  17. Incidence rate of pathogen-specific clinical mastitis on conventional and organic Canadian dairy farms.

    PubMed

    Levison, L J; Miller-Cushon, E K; Tucker, A L; Bergeron, R; Leslie, K E; Barkema, H W; DeVries, T J

    2016-02-01

    Mastitis is a common and costly production disease on dairy farms. In Canada, the incidence rate of clinical mastitis (IRCM) has been determined for conventionally managed dairy farms; however, no studies to date have assessed rates in organically managed systems. The objectives of this observational study were (1) to determine the producer-reported IRCM and predominant pathogen types on conventional and organic dairy farms in Southern Ontario, Canada, and (2) to evaluate the association of both mean overall IRCM and pathogen-specific IRCM with management system, housing type, and pasture access. Data from 59 dairy farms in Southern Ontario, Canada, distributed across conventional (n=41) and organic management (n=18) systems, were collected from April 2011 to May 2012. In addition to management system, farms were categorized by housing method (loose or tie-stall) and pasture access for lactating cows. Participating producers identified and collected samples from 936 cases of clinical mastitis. The most frequently isolated mastitis pathogens were coagulase-negative staphylococci, Bacillus spp., Streptococcus spp., Staphylococcus aureus, and Escherichia coli. The IRCM was higher on conventional farms than organic (23.7 vs. 13.2 cases per 100 cow-years) and was not associated with housing type (loose or tie-stall), pasture access, or herd-average milk yield. Bulk tank somatic cell count tended to be lower on conventional farms than organic (222,000 vs. 272,000 cells/mL). Pathogen-specific IRCM attributed to Staph. aureus, Bacillus spp., and E. coli was greater on conventional than organic farms, but was not associated with housing or any other factors. In conclusion, organic management was associated with reduced overall and pathogen-specific IRCM. PMID:26686728

  18. Age determinations and growth rates of Pacific ferromanganese deposits using strontium isotopes

    USGS Publications Warehouse

    Ingram, B.L.; Hein, J.R.; Farmer, G.L.

    1990-01-01

    87Sr 86Sr ratios, trace element and REE compositions, and textural characteristics were determined for three hydrogenetic Fe-Mn crusts, one hydrothermal deposit, and two mixed hydrothermalhydrogenetic crusts from the Pacific. The Sr isotope data are compared to the Sr seawater curve for the Cenozoic to determine the ages and growth rates of the crusts. The 87Sr 86Sr in the crusts does not increase monotonically with depth as expected if the Sr were solely derived from seawater and perfectly preserved since deposition. This indicates post-depositional exchange of Sr or heterogeneous sources for the Sr originally contained in the crusts. Textures of hydrogenetic crusts generally correlate with Sr isotopic variations. The highest porosity intervals commonly exhibit the highest 87Sr 86Sr ratios, indicating exchange with younger seawater. Intervals with the lowest porosity commonly have lower 87Sr 86Sr and may preserve the original Sr isotopic ratios. Minimum ages of crust growth inception were calculated from dense, low porosity intervals. Growth of the hydrogenetic crusts began at or after 23 Ma, although their substrates are Cretaceous. Estimated average growth rates of the three hydrogenetic crusts vary between 0.9 and 2.7 mm/Ma, consistent with published rates determined by other techniques. Within the Marshall Islands crust, growth rates for individual layers varied greatly between 1.0 and 5.4 mm/Ma. For one crust, very low 87Sr 86Sr ratios occurred in detrital-rich intervals. Hydrothermal Fe-Mn oxide from the active Lau Basin back-arc spreading axis (Valu Fa Ridge) has an 87Sr 86Sr ratio with a predominantly seawater signature ( 87Sr 86Sr 0.709196), indicating a maximum age of 0.9 Ma. One crust from an off-axis seamount west of Gorda Ridge may have begun precipitating hydrogenetically at 0.5 Ma (0.709211), and had increasing hydrothermal or volcanic input in the top half of the crust, indicated by a significantly lower 87Sr 86Sr ratio (0.709052). ?? 1990.

  19. Age-related changes in brain activity are specific for high order cognitive processes during successful encoding of information in working memory

    PubMed Central

    Pinal, Diego; Zurrón, Montserrat; Díaz, Fernando

    2015-01-01

    Memory capacity suffers an age-related decline, which is supposed to be due to a generalized slowing of processing speed and to a reduced availability of processing resources. Information encoding in memory has been demonstrated to be very sensitive to age-related changes, especially when carried out through self-initiated strategies or under high cognitive demands. However, most event-related potentials (ERP) research on age-related changes in working memory (WM) has used tasks that preclude distinction between age-related changes in encoding and retrieval processes. Here, we used ERP recording and a delayed match to sample (DMS) task with two levels of memory load to assess age-related changes in electrical brain activity in young and old adults during successful information encoding in WM. Age-related decline was reflected in lower accuracy rates and longer reaction times in the DMS task. Beside, only old adults presented lower accuracy rates under high than low memory load conditions. However, effects of memory load on brain activity were independent of age and may indicate an increased need of processing after stimulus classification as reflected in larger mean voltages in high than low load conditions between 550 and 1000 ms post-stimulus for young and old adults. Regarding age-related effects on brain activity, results also revealed smaller P2 and P300 amplitudes that may signal the existence of an age dependent reduction in the processing resources available for stimulus evaluation and categorization. Additionally, P2 and N2 latencies were longer in old than in young participants. Furthermore, longer N2 latencies were related to greater accuracy rates on the DMS task, especially in old adults. These results suggest that age-related slowing of processing speed may be specific for target stimulus analysis and evaluation processes. Thus, old adults seem to improve their performance the longer they take to evaluate the stimulus they encode in visual WM. PMID

  20. Age-specific survival of tundra swans on the lower Alaska Peninsula

    USGS Publications Warehouse

    Meixell, Brandt W.; Lindberg, Mark S.; Conn, Paul B.; Dau, Christian P.; Sarvis, John E.; Sowl, Kristine M.

    2013-01-01

    The population of Tundra Swans (Cygnus columbianus columbianus) breeding on the lower Alaska Peninsula represents the southern extremity of the species' range and is uniquely nonmigratory. We used data on recaptures, resightings, and recoveries of neck-collared Tundra Swans on the lower Alaska Peninsula to estimate collar loss, annual apparent survival, and other demographic parameters for the years 1978–1989. Annual collar loss was greater for adult males fitted with either the thinner collar type (0.34) or the thicker collar type (0.15) than for other age/sex classes (thinner: 0.10, thicker: 0.04). The apparent mean probability of survival of adults (0.61) was higher than that of immatures (0.41) and for both age classes varied considerably by year (adult range: 0.44–0.95, immature range: 0.25–0.90). To assess effects of permanent emigration by age and breeding class, we analyzed post hoc the encounter histories of swans known to breed in our study area. The apparent mean survival of known breeders (0.65) was generally higher than that of the entire marked sample but still varied considerably by year (range 0.26–1.00) and indicated that permanent emigration of breeding swans was likely. We suggest that reductions in apparent survival probability were influenced primarily by high and variable rates of permanent emigration and that immigration by swans from elsewhere may be important in sustaining a breeding population at and near Izembek National Wildlife Refuge.

  1. Physiological and Transcriptional Responses of Different Industrial Microbes at Near-Zero Specific Growth Rates

    PubMed Central

    Ercan, Onur; Bisschops, Markus M. M.; Overkamp, Wout; Jørgensen, Thomas R.; Ram, Arthur F.; Smid, Eddy J.; Pronk, Jack T.; Kuipers, Oscar P.

    2015-01-01

    The current knowledge of the physiology and gene expression of industrially relevant microorganisms is largely based on laboratory studies under conditions of rapid growth and high metabolic activity. However, in natural ecosystems and industrial processes, microbes frequently encounter severe calorie restriction. As a consequence, microbial growth rates in such settings can be extremely slow and even approach zero. Furthermore, uncoupling microbial growth from product formation, while cellular integrity and activity are maintained, offers perspectives that are economically highly interesting. Retentostat cultures have been employed to investigate microbial physiology at (near-)zero growth rates. This minireview compares information from recent physiological and gene expression studies on retentostat cultures of the industrially relevant microorganisms Lactobacillus plantarum, Lactococcus lactis, Bacillus subtilis, Saccharomyces cerevisiae, and Aspergillus niger. Shared responses of these organisms to (near-)zero growth rates include increased stress tolerance and a downregulation of genes involved in protein synthesis. Other adaptations, such as changes in morphology and (secondary) metabolite production, were species specific. This comparison underlines the industrial and scientific significance of further research on microbial (near-)zero growth physiology. PMID:26048933

  2. Specific growth rate observer for the growing phase of a Polyhydroxybutyrate production process.

    PubMed

    Jamilis, Martín; Garelli, Fabricio; Mozumder, Md Salatul Islam; Volcke, Eveline; De Battista, Hernán

    2015-03-01

    This paper focuses on the specific growth rate estimation problem in a Polyhydroxybutyrate bioplastic production process by industrial fermentation. The kinetics of the process are unknown and there are uncertainties in the model parameters and inputs. During the first hours of the growth phase of the process, biomass concentration can be measured online by an optical density sensor, but as cell density increases this method becomes ineffective and biomass measurement is lost. An asymptotic observer is developed to estimate the growth rate for the case without biomass measurement based on corrections made by a pH control loop. Furthermore, an exponential observer based on the biomass measurement is developed to estimate the growth rate during the first hours, which gives the initial condition to the asymptotic observer. Error bounds and robustness to uncertainties in the models and in the inputs are found. The estimation is independent of the kinetic models of the microorganism. The characteristic features of the observer are illustrated by numerical simulations and validated by experimental results. PMID:25307471

  3. Physiological and Transcriptional Responses of Different Industrial Microbes at Near-Zero Specific Growth Rates.

    PubMed

    Ercan, Onur; Bisschops, Markus M M; Overkamp, Wout; Jørgensen, Thomas R; Ram, Arthur F; Smid, Eddy J; Pronk, Jack T; Kuipers, Oscar P; Daran-Lapujade, Pascale; Kleerebezem, Michiel

    2015-09-01

    The current knowledge of the physiology and gene expression of industrially relevant microorganisms is largely based on laboratory studies under conditions of rapid growth and high metabolic activity. However, in natural ecosystems and industrial processes, microbes frequently encounter severe calorie restriction. As a consequence, microbial growth rates in such settings can be extremely slow and even approach zero. Furthermore, uncoupling microbial growth from product formation, while cellular integrity and activity are maintained, offers perspectives that are economically highly interesting. Retentostat cultures have been employed to investigate microbial physiology at (near-)zero growth rates. This minireview compares information from recent physiological and gene expression studies on retentostat cultures of the industrially relevant microorganisms Lactobacillus plantarum, Lactococcus lactis, Bacillus subtilis, Saccharomyces cerevisiae, and Aspergillus niger. Shared responses of these organisms to (near-)zero growth rates include increased stress tolerance and a downregulation of genes involved in protein synthesis. Other adaptations, such as changes in morphology and (secondary) metabolite production, were species specific. This comparison underlines the industrial and scientific significance of further research on microbial (near-)zero growth physiology.

  4. Age- and Sex-Specific Social Contact Patterns and Incidence of Mycobacterium tuberculosis Infection

    PubMed Central

    Dodd, Peter J.; Looker, Clare; Plumb, Ian D.; Bond, Virginia; Schaap, Ab; Shanaube, Kwame; Muyoyeta, Monde; Vynnycky, Emilia; Godfrey-Faussett, Peter; Corbett, Elizabeth L.; Beyers, Nulda; Ayles, Helen; White, Richard G.

    2016-01-01

    We aimed to model the incidence of infection with Mycobacterium tuberculosis among adults using data on infection incidence in children, disease prevalence in adults, and social contact patterns. We conducted a cross-sectional face-to-face survey of adults in 2011, enumerating “close” (shared conversation) and “casual” (shared indoor space) social contacts in 16 Zambian communities and 8 South African communities. We modeled the incidence of M. tuberculosis infection in all age groups using these contact patterns, as well as the observed incidence of M. tuberculosis infection in children and the prevalence of tuberculosis disease in adults. A total of 3,528 adults participated in the study. The reported rates of close and casual contact were 4.9 per adult per day (95% confidence interval: 4.6, 5.2) and 10.4 per adult per day (95% confidence interval: 9.3, 11.6), respectively. Rates of close contact were higher for adults in larger households and rural areas. There was preferential mixing of close contacts within age groups and within sexes. The estimated incidence of M. tuberculosis infection in adults was 1.5–6 times higher (2.5%–10% per year) than that in children. More than 50% of infections in men, women, and children were estimated to be due to contact with adult men. We conclude that estimates of infection incidence based on surveys in children might underestimate incidence in adults. Most infections may be due to contact with adult men. Treatment and control of tuberculosis in men is critical to protecting men, women, and children from tuberculosis. PMID:26646292

  5. Age-specific effect of heterozygosity on survival in alpine marmots, Marmota marmota.

    PubMed

    Cohas, Aurélie; Bonenfant, Christophe; Kempenaers, Bart; Allainé, Dominique

    2009-04-01

    The fitness consequences of heterozygosity and the mechanisms underpinning them are still highly controversial. Using capture-mark-recapture models, we investigated the effects of individual heterozygosity, measured at 16 microsatellite markers, on age-dependent survival and access to dominance in a socially monogamous mammalian species, the alpine marmot. We found a positive correlation between standardized multilocus heterozygosity and juvenile survival. However, there was no correlation between standardized multilocus heterozygosity and either survival of older individuals or access to dominance. The disappearance of a significant heterozygosity fitness correlation when individuals older than juveniles are considered is consistent with the prediction that differences in survival among individuals are maximal early in life. The lack of a correlation between heterozygosity and access to dominance may be a consequence of few homozygous individuals attaining the age at which they might reach dominance. Two hypotheses have been proposed to explain heterozygosity-fitness correlations: genome-wide effects reflected by all markers or local effects of specific markers linked to genes that determine fitness. In accordance with genome-wide effects of heterozygosity, we found significant correlations between heterozygosities calculated across single locus or across two sets of eight loci. Thus, the genome-wide heterozygosity effect seems to explain the observed heterozygosity-fitness correlation in the alpine marmot.

  6. Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

    PubMed

    Perry, John R B; Day, Felix; Elks, Cathy E; Sulem, Patrick; Thompson, Deborah J; Ferreira, Teresa; He, Chunyan; Chasman, Daniel I; Esko, Tõnu; Thorleifsson, Gudmar; Albrecht, Eva; Ang, Wei Q; Corre, Tanguy; Cousminer, Diana L; Feenstra, Bjarke; Franceschini, Nora; Ganna, Andrea; Johnson, Andrew D; Kjellqvist, Sanela; Lunetta, Kathryn L; McMahon, George; Nolte, Ilja M; Paternoster, Lavinia; Porcu, Eleonora; Smith, Albert V; Stolk, Lisette; Teumer, Alexander; Tšernikova, Natalia; Tikkanen, Emmi; Ulivi, Sheila; Wagner, Erin K; Amin, Najaf; Bierut, Laura J; Byrne, Enda M; Hottenga, Jouke-Jan; Koller, Daniel L; Mangino, Massimo; Pers, Tune H; Yerges-Armstrong, Laura M; Hua Zhao, Jing; Andrulis, Irene L; Anton-Culver, Hoda; Atsma, Femke; Bandinelli, Stefania; Beckmann, Matthias W; Benitez, Javier; Blomqvist, Carl; Bojesen, Stig E; Bolla, Manjeet K; Bonanni, Bernardo; Brauch, Hiltrud; Brenner, Hermann; Buring, Julie E; Chang-Claude, Jenny; Chanock, Stephen; Chen, Jinhui; Chenevix-Trench, Georgia; Collée, J Margriet; Couch, Fergus J; Couper, David; Coviello, Andrea D; Cox, Angela; Czene, Kamila; D'adamo, Adamo Pio; Davey Smith, George; De Vivo, Immaculata; Demerath, Ellen W; Dennis, Joe; Devilee, Peter; Dieffenbach, Aida K; Dunning, Alison M; Eiriksdottir, Gudny; Eriksson, Johan G; Fasching, Peter A; Ferrucci, Luigi; Flesch-Janys, Dieter; Flyger, Henrik; Foroud, Tatiana; Franke, Lude; Garcia, Melissa E; García-Closas, Montserrat; Geller, Frank; de Geus, Eco E J; Giles, Graham G; Gudbjartsson, Daniel F; Gudnason, Vilmundur; Guénel, Pascal; Guo, Suiqun; Hall, Per; Hamann, Ute; Haring, Robin; Hartman, Catharina A; Heath, Andrew C; Hofman, Albert; Hooning, Maartje J; Hopper, John L; Hu, Frank B; Hunter, David J; Karasik, David; Kiel, Douglas P; Knight, Julia A; Kosma, Veli-Matti; Kutalik, Zoltan; Lai, Sandra; Lambrechts, Diether; Lindblom, Annika; Mägi, Reedik; Magnusson, Patrik K; Mannermaa, Arto; Martin, Nicholas G; Masson, Gisli; McArdle, Patrick F; McArdle, Wendy L; Melbye, Mads; Michailidou, Kyriaki; Mihailov, Evelin; Milani, Lili; Milne, Roger L; Nevanlinna, Heli; Neven, Patrick; Nohr, Ellen A; Oldehinkel, Albertine J; Oostra, Ben A; Palotie, Aarno; Peacock, Munro; Pedersen, Nancy L; Peterlongo, Paolo; Peto, Julian; Pharoah, Paul D P; Postma, Dirkje S; Pouta, Anneli; Pylkäs, Katri; Radice, Paolo; Ring, Susan; Rivadeneira, Fernando; Robino, Antonietta; Rose, Lynda M; Rudolph, Anja; Salomaa, Veikko; Sanna, Serena; Schlessinger, David; Schmidt, Marjanka K; Southey, Mellissa C; Sovio, Ulla; Stampfer, Meir J; Stöckl, Doris; Storniolo, Anna M; Timpson, Nicholas J; Tyrer, Jonathan; Visser, Jenny A; Vollenweider, Peter; Völzke, Henry; Waeber, Gerard; Waldenberger, Melanie; Wallaschofski, Henri; Wang, Qin; Willemsen, Gonneke; Winqvist, Robert; Wolffenbuttel, Bruce H R; Wright, Margaret J; Boomsma, Dorret I; Econs, Michael J; Khaw, Kay-Tee; Loos, Ruth J F; McCarthy, Mark I; Montgomery, Grant W; Rice, John P; Streeten, Elizabeth A; Thorsteinsdottir, Unnur; van Duijn, Cornelia M; Alizadeh, Behrooz Z; Bergmann, Sven; Boerwinkle, Eric; Boyd, Heather A; Crisponi, Laura; Gasparini, Paolo; Gieger, Christian; Harris, Tamara B; Ingelsson, Erik; Järvelin, Marjo-Riitta; Kraft, Peter; Lawlor, Debbie; Metspalu, Andres; Pennell, Craig E; Ridker, Paul M; Snieder, Harold; Sørensen, Thorkild I A; Spector, Tim D; Strachan, David P; Uitterlinden, André G; Wareham, Nicholas J; Widen, Elisabeth; Zygmunt, Marek; Murray, Anna; Easton, Douglas F; Stefansson, Kari; Murabito, Joanne M; Ong, Ken K

    2014-10-01

    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition. PMID:25231870

  7. Age-Specific Lipid and Fatty Acid Profiles of Atlantic Salmon Juveniles in the Varzuga River

    PubMed Central

    Murzina, Svetlana A.; Nefedova, Zinaida A.; Pekkoeva, Svetlana N.; Veselov, Alexey E.; Efremov, Denis A.; Nemova, Nina N.

    2016-01-01

    The age-specific lipid and fatty acid profiles of juvenile Atlantic salmon at different ages (0+, 1+, and 2+ years) after hatching from nests located in the mainstream of a large Arctic River, the Varzuga River, and resettling to the favorable Sobachji shoal in autumn before overwinter are herein presented. The contemporary methods of the lipid analysis were used: thin layer chromatography and gas chromatography. The results show that the stability of the regulation of important functions in developing organisms is maintained through structural alterations in lipids. These alterations can be considered as a sequence of the modifications and changes in the ratios of certain lipid classes and fatty acids constituents. In general, changes in the lipids and fatty acids (FAs) maintained the physiological limits and controls through the adaptive systems of the organism. The mechanisms of juvenile fish biochemical adaptation to the environmental conditions in the studied biotope include the modification of the energy metabolism and anabolism, and here belongs to the energy characteristics of metabolic processes. PMID:27376274

  8. Parent-of-origin specific allelic associations among 106 genomic loci for age at menarche

    PubMed Central

    Thompson, Deborah J; Ferreira, Teresa; He, Chunyan; Chasman, Daniel I; Esko, Tõnu; Thorleifsson, Gudmar; Albrecht, Eva; Ang, Wei Q; Corre, Tanguy; Cousminer, Diana L; Feenstra, Bjarke; Franceschini, Nora; Ganna, Andrea; Johnson, Andrew D; Kjellqvist, Sanela; Lunetta, Kathryn L; McMahon, George; Nolte, Ilja M; Paternoster, Lavinia; Porcu, Eleonora; Smith, Albert V; Stolk, Lisette; Teumer, Alexander; Tšernikova, Natalia; Tikkanen, Emmi; Ulivi, Sheila; Wagner, Erin K; Amin, Najaf; Bierut, Laura J; Byrne, Enda M; Hottenga, Jouke-Jan; Koller, Daniel L; Mangino, Massimo; Pers, Tune H; Yerges-Armstrong, Laura M; Zhao, Jing Hua; Andrulis, Irene L; Anton-Culver, Hoda; Atsma, Femke; Bandinelli, Stefania; Beckmann, Matthias W; Benitez, Javier; Blomqvist, Carl; Bojesen, Stig E; Bolla, Manjeet K; Bonanni, Bernardo; Brauch, Hiltrud; Brenner, Hermann; Buring, Julie E; Chang-Claude, Jenny; Chanock, Stephen; Chen, Jinhui; Chenevix-Trench, Georgia; Collée, J. Margriet; Couch, Fergus J; Couper, David; Coveillo, Andrea D; Cox, Angela; Czene, Kamila; D’adamo, Adamo Pio; Smith, George Davey; De Vivo, Immaculata; Demerath, Ellen W; Dennis, Joe; Devilee, Peter; Dieffenbach, Aida K; Dunning, Alison M; Eiriksdottir, Gudny; Eriksson, Johan G; Fasching, Peter A; Ferrucci, Luigi; Flesch-Janys, Dieter; Flyger, Henrik; Foroud, Tatiana; Franke, Lude; Garcia, Melissa E; García-Closas, Montserrat; Geller, Frank; de Geus, Eco EJ; Giles, Graham G; Gudbjartsson, Daniel F; Gudnason, Vilmundur; Guénel, Pascal; Guo, Suiqun; Hall, Per; Hamann, Ute; Haring, Robin; Hartman, Catharina A; Heath, Andrew C; Hofman, Albert; Hooning, Maartje J; Hopper, John L; Hu, Frank B; Hunter, David J; Karasik, David; Kiel, Douglas P; Knight, Julia A; Kosma, Veli-Matti; Kutalik, Zoltan; Lai, Sandra; Lambrechts, Diether; Lindblom, Annika; Mägi, Reedik; Magnusson, Patrik K; Mannermaa, Arto; Martin, Nicholas G; Masson, Gisli; McArdle, Patrick F; McArdle, Wendy L; Melbye, Mads; Michailidou, Kyriaki; Mihailov, Evelin; Milani, Lili; Milne, Roger L; Nevanlinna, Heli; Neven, Patrick; Nohr, Ellen A; Oldehinkel, Albertine J; Oostra, Ben A; Palotie, Aarno; Peacock, Munro; Pedersen, Nancy L; Peterlongo, Paolo; Peto, Julian; Pharoah, Paul DP; Postma, Dirkje S; Pouta, Anneli; Pylkäs, Katri; Radice, Paolo; Ring, Susan; Rivadeneira, Fernando; Robino, Antonietta; Rose, Lynda M; Rudolph, Anja; Salomaa, Veikko; Sanna, Serena; Schlessinger, David; Schmidt, Marjanka K; Southey, Mellissa C; Sovio, Ulla; Stampfer, Meir J; Stöckl, Doris; Storniolo, Anna M; Timpson, Nicholas J; Tyrer, Jonathan; Visser, Jenny A; Vollenweider, Peter; Völzke, Henry; Waeber, Gerard; Waldenberger, Melanie; Wallaschofski, Henri; Wang, Qin; Willemsen, Gonneke; Winqvist, Robert; Wolffenbuttel, Bruce HR; Wright, Margaret J; Boomsma, Dorret I; Econs, Michael J; Khaw, Kay-Tee; Loos, Ruth JF; McCarthy, Mark I; Montgomery, Grant W; Rice, John P; Streeten, Elizabeth A; Thorsteinsdottir, Unnur; van Duijn, Cornelia M; Alizadeh, Behrooz Z; Bergmann, Sven; Boerwinkle, Eric; Boyd, Heather A; Crisponi, Laura; Gasparini, Paolo; Gieger, Christian; Harris, Tamara B; Ingelsson, Erik; Järvelin, Marjo-Riitta; Kraft, Peter; Lawlor, Debbie; Metspalu, Andres; Pennell, Craig E; Ridker, Paul M; Snieder, Harold; Sørensen, Thorkild IA; Spector, Tim D; Strachan, David P; Uitterlinden, André G; Wareham, Nicholas J; Widen, Elisabeth; Zygmunt, Marek; Murray, Anna; Easton, Douglas F

    2014-01-01

    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality1. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation2,3, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P<5×10−8) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1/WDR25, MKRN3/MAGEL2 and KCNK9) demonstrating parent-of-origin specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and gamma-aminobutyric acid-B2 receptor signaling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition. PMID:25231870

  9. Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

    PubMed

    Perry, John R B; Day, Felix; Elks, Cathy E; Sulem, Patrick; Thompson, Deborah J; Ferreira, Teresa; He, Chunyan; Chasman, Daniel I; Esko, Tõnu; Thorleifsson, Gudmar; Albrecht, Eva; Ang, Wei Q; Corre, Tanguy; Cousminer, Diana L; Feenstra, Bjarke; Franceschini, Nora; Ganna, Andrea; Johnson, Andrew D; Kjellqvist, Sanela; Lunetta, Kathryn L; McMahon, George; Nolte, Ilja M; Paternoster, Lavinia; Porcu, Eleonora; Smith, Albert V; Stolk, Lisette; Teumer, Alexander; Tšernikova, Natalia; Tikkanen, Emmi; Ulivi, Sheila; Wagner, Erin K; Amin, Najaf; Bierut, Laura J; Byrne, Enda M; Hottenga, Jouke-Jan; Koller, Daniel L; Mangino, Massimo; Pers, Tune H; Yerges-Armstrong, Laura M; Hua Zhao, Jing; Andrulis, Irene L; Anton-Culver, Hoda; Atsma, Femke; Bandinelli, Stefania; Beckmann, Matthias W; Benitez, Javier; Blomqvist, Carl; Bojesen, Stig E; Bolla, Manjeet K; Bonanni, Bernardo; Brauch, Hiltrud; Brenner, Hermann; Buring, Julie E; Chang-Claude, Jenny; Chanock, Stephen; Chen, Jinhui; Chenevix-Trench, Georgia; Collée, J Margriet; Couch, Fergus J; Couper, David; Coviello, Andrea D; Cox, Angela; Czene, Kamila; D'adamo, Adamo Pio; Davey Smith, George; De Vivo, Immaculata; Demerath, Ellen W; Dennis, Joe; Devilee, Peter; Dieffenbach, Aida K; Dunning, Alison M; Eiriksdottir, Gudny; Eriksson, Johan G; Fasching, Peter A; Ferrucci, Luigi; Flesch-Janys, Dieter; Flyger, Henrik; Foroud, Tatiana; Franke, Lude; Garcia, Melissa E; García-Closas, Montserrat; Geller, Frank; de Geus, Eco E J; Giles, Graham G; Gudbjartsson, Daniel F; Gudnason, Vilmundur; Guénel, Pascal; Guo, Suiqun; Hall, Per; Hamann, Ute; Haring, Robin; Hartman, Catharina A; Heath, Andrew C; Hofman, Albert; Hooning, Maartje J; Hopper, John L; Hu, Frank B; Hunter, David J; Karasik, David; Kiel, Douglas P; Knight, Julia A; Kosma, Veli-Matti; Kutalik, Zoltan; Lai, Sandra; Lambrechts, Diether; Lindblom, Annika; Mägi, Reedik; Magnusson, Patrik K; Mannermaa, Arto; Martin, Nicholas G; Masson, Gisli; McArdle, Patrick F; McArdle, Wendy L; Melbye, Mads; Michailidou, Kyriaki; Mihailov, Evelin; Milani, Lili; Milne, Roger L; Nevanlinna, Heli; Neven, Patrick; Nohr, Ellen A; Oldehinkel, Albertine J; Oostra, Ben A; Palotie, Aarno; Peacock, Munro; Pedersen, Nancy L; Peterlongo, Paolo; Peto, Julian; Pharoah, Paul D P; Postma, Dirkje S; Pouta, Anneli; Pylkäs, Katri; Radice, Paolo; Ring, Susan; Rivadeneira, Fernando; Robino, Antonietta; Rose, Lynda M; Rudolph, Anja; Salomaa, Veikko; Sanna, Serena; Schlessinger, David; Schmidt, Marjanka K; Southey, Mellissa C; Sovio, Ulla; Stampfer, Meir J; Stöckl, Doris; Storniolo, Anna M; Timpson, Nicholas J; Tyrer, Jonathan; Visser, Jenny A; Vollenweider, Peter; Völzke, Henry; Waeber, Gerard; Waldenberger, Melanie; Wallaschofski, Henri; Wang, Qin; Willemsen, Gonneke; Winqvist, Robert; Wolffenbuttel, Bruce H R; Wright, Margaret J; Boomsma, Dorret I; Econs, Michael J; Khaw, Kay-Tee; Loos, Ruth J F; McCarthy, Mark I; Montgomery, Grant W; Rice, John P; Streeten, Elizabeth A; Thorsteinsdottir, Unnur; van Duijn, Cornelia M; Alizadeh, Behrooz Z; Bergmann, Sven; Boerwinkle, Eric; Boyd, Heather A; Crisponi, Laura; Gasparini, Paolo; Gieger, Christian; Harris, Tamara B; Ingelsson, Erik; Järvelin, Marjo-Riitta; Kraft, Peter; Lawlor, Debbie; Metspalu, Andres; Pennell, Craig E; Ridker, Paul M; Snieder, Harold; Sørensen, Thorkild I A; Spector, Tim D; Strachan, David P; Uitterlinden, André G; Wareham, Nicholas J; Widen, Elisabeth; Zygmunt, Marek; Murray, Anna; Easton, Douglas F; Stefansson, Kari; Murabito, Joanne M; Ong, Ken K

    2014-10-01

    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition.

  10. Development of age-specific Japanese head phantoms for dose evaluation in paediatric head CT examinations.

    PubMed

    Yamauchi-Kawaura, C; Fujii, K; Akahane, K; Yamauchi, M; Narai, K; Aoyama, T; Katsu, T; Obara, S; Imai, K; Ikeda, M

    2015-02-01

    In this study, the authors developed age-specific physical head phantoms simulating the physique of Japanese children for dose evaluation in paediatric head computed tomography (CT) examinations. Anatomical structures at 99 places in 0-, 0.5-, 1- and 3-y-old Japanese patients were measured using DICOM viewer software from CT images, and the head phantom of each age was designed. For trial manufacture, a 3-y-old head phantom consisting of acrylic resin and gypsum was produced by machine processing. Radiation doses for the head phantom were measured with radiophotoluminescence glass dosemeters and Si-pin photodiode dosemeters. To investigate whether the phantom shape was suitable for dose evaluation, organ doses in the same scan protocol were compared between the 3-y-old head and commercially available anthropomorphic phantoms having approximately the same head size. The doses of organs in both phantoms were equivalent. The authors' designed paediatric head phantom will be useful for dose evaluation in paediatric head CT examinations.

  11. Age-Specific Lipid and Fatty Acid Profiles of Atlantic Salmon Juveniles in the Varzuga River.

    PubMed

    Murzina, Svetlana A; Nefedova, Zinaida A; Pekkoeva, Svetlana N; Veselov, Alexey E; Efremov, Denis A; Nemova, Nina N

    2016-01-01

    The age-specific lipid and fatty acid profiles of juvenile Atlantic salmon at different ages (0+, 1+, and 2+ years) after hatching from nests located in the mainstream of a large Arctic River, the Varzuga River, and resettling to the favorable Sobachji shoal in autumn before overwinter are herein presented. The contemporary methods of the lipid analysis were used: thin layer chromatography and gas chromatography. The results show that the stability of the regulation of important functions in developing organisms is maintained through structural alterations in lipids. These alterations can be considered as a sequence of the modifications and changes in the ratios of certain lipid classes and fatty acids constituents. In general, changes in the lipids and fatty acids (FAs) maintained the physiological limits and controls through the adaptive systems of the organism. The mechanisms of juvenile fish biochemical adaptation to the environmental conditions in the studied biotope include the modification of the energy metabolism and anabolism, and here belongs to the energy characteristics of metabolic processes.

  12. Age-specific survival of reintroduced swift fox in Badlands National Park and surrounding lands

    USGS Publications Warehouse

    Sasmal, Indrani; Klaver, Robert W.; Jenks, Jonathan A.; Schroeder, Greg M.

    2016-01-01

    In 2003, a reintroduction program was initiated at Badlands National Park (BNP), South Dakota, USA, with swift foxes (Vulpes velox) translocated from Colorado and Wyoming, USA, as part of a restoration effort to recover declining swift fox populations throughout its historical range. Estimates of age-specific survival are necessary to evaluate the potential for population growth of reintroduced populations. We used 7 years (2003–2009) of capture–recapture data of 243 pups, 29 yearlings, and 69 adult swift foxes at BNP and the surrounding area to construct Cormack–Jolly–Seber model estimates of apparent survival within a capture–mark–recapture framework using Program MARK. The best model for estimating recapture probabilities included no differences among age classes, greater recapture probabilities during early years of the monitoring effort than later years, and variation among spring, winter, and summer. Our top ranked survival model indicated pup survival differed from that of yearlings and adults and varied by month and year. The apparent annual survival probability of pups (0.47, SE = 0.10) in our study area was greater than the apparent annual survival probability of yearlings and adults (0.27, SE = 0.08). Our results indicate low survival probabilities for a reintroduced population of swift foxes in the BNP and surrounding areas. Management of reintroduced populations and future reintroductions of swift foxes should consider the effects of relative low annual survival on population demography.

  13. Age-Specific Lipid and Fatty Acid Profiles of Atlantic Salmon Juveniles in the Varzuga River.

    PubMed

    Murzina, Svetlana A; Nefedova, Zinaida A; Pekkoeva, Svetlana N; Veselov, Alexey E; Efremov, Denis A; Nemova, Nina N

    2016-01-01

    The age-specific lipid and fatty acid profiles of juvenile Atlantic salmon at different ages (0+, 1+, and 2+ years) after hatching from nests located in the mainstream of a large Arctic River, the Varzuga River, and resettling to the favorable Sobachji shoal in autumn before overwinter are herein presented. The contemporary methods of the lipid analysis were used: thin layer chromatography and gas chromatography. The results show that the stability of the regulation of important functions in developing organisms is maintained through structural alterations in lipids. These alterations can be considered as a sequence of the modifications and changes in the ratios of certain lipid classes and fatty acids constituents. In general, changes in the lipids and fatty acids (FAs) maintained the physiological limits and controls through the adaptive systems of the organism. The mechanisms of juvenile fish biochemical adaptation to the environmental conditions in the studied biotope include the modification of the energy metabolism and anabolism, and here belongs to the energy characteristics of metabolic processes. PMID:27376274

  14. Initiation age and incision rates of inner gorges: Do they record multiple glacial-interglacial cycles?

    NASA Astrophysics Data System (ADS)

    Delunel, Romain; Casagrande, Jan; Schlunegger, Fritz; Akçar, Naki; Kubik, Peter W.

    2015-04-01

    Inner gorges represent some of the most conspicuous landforms in the European Alps. They form narrow and deep active-channel incisions that link hanging tributaries with trunk valleys in glacially-conditioned environments. Despite abundant research carried out on these objects, both their origin and evolution have remained unclear. In particular, the age of initiation, the rate of incision, and the respective contribution of fluvial and subglacial processes in the evolution of inner gorges have still been a matter of scientific debate. Indeed, answering these questions has been complicated by the lack of appropriate quantitative methods and/or suitable sampling strategies for studying inner gorges. Here, we report 10Be concentrations measured in alluvial sediments that have been collected along the main stream of a ~20-km2-catchment in the Swiss foreland (Central European Alps). This catchment hosts a ca. 100-m-deep and 2-km-long inner gorge that has been cut mainly in glacial till. Catchment wide denudation rates inferred from 10Be analyses (n = 15) vary from ~120 to 650 mm/ka and show a general downstream increasing trend. Additional field observations and GIS analyses reveal that the denudation rates within the catchment increase from the headwaters, characterized by relict glacial/periglacial landscapes, to the downstream end of the basin where the inner gorge has been formed. Using a 10Be-based sediment budget approach and the delineation of topographic domains from a 2-m-resolution LIDAR, we provide an estimate of erosion rates within the gorge that are higher than 2.5 m/ka and can reach up to ~ 7 m/ka. Combining these estimated erosion rates with the reconstruction of eroded volumes within the gorge, we obtain a rough initiation age in the early Holocene, in general agreement with previous studies reporting a postglacial origin for the inner gorges. Our results therefore appear contradictory with recent findings arguing for a gradual formation of inner

  15. Nitrogen Isotope Fractionation Increases with the Cell-Specific Dissimilatory Nitrate Reduction Rate

    NASA Astrophysics Data System (ADS)

    Kritee, K.; Sigman, D. M.; Granger, J.

    2009-12-01

    The use of the nitrogen (N) isotopes to estimate the impacts and rates of different N transformations depends on knowledge of their extent of isotope fractionation under environmentally relevant physico-chemical conditions. Though the extent of N isotope fractionation during denitrification by pure cultures of bacteria has been determined in the past, relatively large variation in the isotope effect during apparently replicate experiments has been perplexing and the values that should be most relevant for environmental applications have not been clear. We measured the extent of N and O isotope fractionation during nitrate reduction by two bacterial denitrifiers, Pseudomonas chlororaphis ATCC 43928 and Paracoccus denitrificans ATCC 19367 that were grown in 1L batch reactors in the presence of differing carbon sources that included complex organic (e.g, bactopeptone and casein) or defined (e.g., glucose and acetate) carbon compounds and varying concentrations of dissolved oxygen (0 - 4 mM) and nitrate (25 - 800 mM) in the assay medium. For P. denitrificans and P. Chlororaphis , the total range of the N isotope effect (15ɛ) varied from 22.3 to 9.3 ‰ and 34.3 to 15.6 ‰, respectively. Despite this large variation, the O-to-N isotope effect ratio centered around 1, consistent with our previous work. A systematic pattern that has emerged from these studies is that the N and O isotope effect during denitrification increases with increasing cell specific nitrate reduction (CSNR) rate. This sense of variation runs counter to expectations from studies of carbon and sulfur isotope effects during methanogenesis and sulfate reduction, respectively, in which higher substrate consumption rates are associated with lower isotope effects. As with many multi-step microbial processes, variability in the dissimilatory nitrate reduction isotope effect may arise from variation in the “relative” rate and reversibility of (1) nitrate uptake into the denitrifying cell, and/or (2

  16. Self-Rated Health among Urban Adolescents: The Roles of Age, Gender, and Their Associated Factors

    PubMed Central

    Meireles, Adriana Lúcia; Xavier, César Coelho; de Souza Andrade, Amanda Cristina; Proietti, Fernando Augusto; Caiaffa, Waleska Teixeira

    2015-01-01

    Health status is often analyzed in population surveys. Self-rated health (SRH) is a single-item summary measure of the perception of one’s health. In Brazil, studies on the SRH of adolescents remain scarce, especially those aiming to understand the domains that compose this construct. Therefore, the aim of this study is to determine the prevalence of poor SRH and its associated factors among 11- to 13-year-olds and 14- to 17-year-olds living in a large urban center in Brazil. This cross-sectional study was conducted using a household survey across Belo Horizonte that included 1,042 adolescents. Stratified logistic regression models were used for each age group to assess the associations between worse SRH and the following variables: socio-demographic, social and family support, lifestyles, psychological health, and anthropometry. Approximately 11% (95% CIs = 8.7–13.6) of the studied adolescents rated their health as poor, and SHR decreased with age among males and females. This trend was more pronounced among girls (from 6.9% among 11- to 13-year-old girls to 16.9% among 14- to 17-year-old girls) than boys (from 8.3% among 11- to 13-year-old boys to 11% among 14- to 17-year-old boys). Worse SRH was associated with family support (as assessed by the absence of parent-adolescent conversations; odds ratio [OR] = 3.5 among 11- to 13-year-olds), family structure (OR = 2.8 among 14- to 17-year-olds), and argument reporting (OR = 8.2 among 14- to 17-year-olds). Among older adolescents, the consumption of fruit fewer than five times per week (OR = 2.4), life dissatisfaction (OR = 2.8), underweight status (OR = 6.7), and overweight status (OR = 2.7) were associated with poor SRH. As adolescents age, their universe expands from their relationship with their parents to include more complex issues, such as their lifestyles and life satisfaction. Therefore, these results suggest the importance of evaluating SRH across adolescent age groups and demonstrate the influence of

  17. Self-Rated Health among Urban Adolescents: The Roles of Age, Gender, and Their Associated Factors.

    PubMed

    Meireles, Adriana Lúcia; Xavier, César Coelho; de Souza Andrade, Amanda Cristina; Proietti, Fernando Augusto; Caiaffa, Waleska Teixeira

    2015-01-01

    Health status is often analyzed in population surveys. Self-rated health (SRH) is a single-item summary measure of the perception of one's health. In Brazil, studies on the SRH of adolescents remain scarce, especially those aiming to understand the domains that compose this construct. Therefore, the aim of this study is to determine the prevalence of poor SRH and its associated factors among 11- to 13-year-olds and 14- to 17-year-olds living in a large urban center in Brazil. This cross-sectional study was conducted using a household survey across Belo Horizonte that included 1,042 adolescents. Stratified logistic regression models were used for each age group to assess the associations between worse SRH and the following variables: socio-demographic, social and family support, lifestyles, psychological health, and anthropometry. Approximately 11% (95% CIs = 8.7-13.6) of the studied adolescents rated their health as poor, and SHR decreased with age among males and females. This trend was more pronounced among girls (from 6.9% among 11- to 13-year-old girls to 16.9% among 14- to 17-year-old girls) than boys (from 8.3% among 11- to 13-year-old boys to 11% among 14- to 17-year-old boys). Worse SRH was associated with family support (as assessed by the absence of parent-adolescent conversations; odds ratio [OR] = 3.5 among 11- to 13-year-olds), family structure (OR = 2.8 among 14- to 17-year-olds), and argument reporting (OR = 8.2 among 14- to 17-year-olds). Among older adolescents, the consumption of fruit fewer than five times per week (OR = 2.4), life dissatisfaction (OR = 2.8), underweight status (OR = 6.7), and overweight status (OR = 2.7) were associated with poor SRH. As adolescents age, their universe expands from their relationship with their parents to include more complex issues, such as their lifestyles and life satisfaction. Therefore, these results suggest the importance of evaluating SRH across adolescent age groups and demonstrate the influence of the

  18. Self-Rated Health among Urban Adolescents: The Roles of Age, Gender, and Their Associated Factors.

    PubMed

    Meireles, Adriana Lúcia; Xavier, César Coelho; de Souza Andrade, Amanda Cristina; Proietti, Fernando Augusto; Caiaffa, Waleska Teixeira

    2015-01-01

    Health status is often analyzed in population surveys. Self-rated health (SRH) is a single-item summary measure of the perception of one's health. In Brazil, studies on the SRH of adolescents remain scarce, especially those aiming to understand the domains that compose this construct. Therefore, the aim of this study is to determine the prevalence of poor SRH and its associated factors among 11- to 13-year-olds and 14- to 17-year-olds living in a large urban center in Brazil. This cross-sectional study was conducted using a household survey across Belo Horizonte that included 1,042 adolescents. Stratified logistic regression models were used for each age group to assess the associations between worse SRH and the following variables: socio-demographic, social and family support, lifestyles, psychological health, and anthropometry. Approximately 11% (95% CIs = 8.7-13.6) of the studied adolescents rated their health as poor, and SHR decreased with age among males and females. This trend was more pronounced among girls (from 6.9% among 11- to 13-year-old girls to 16.9% among 14- to 17-year-old girls) than boys (from 8.3% among 11- to 13-year-old boys to 11% among 14- to 17-year-old boys). Worse SRH was associated with family support (as assessed by the absence of parent-adolescent conversations; odds ratio [OR] = 3.5 among 11- to 13-year-olds), family structure (OR = 2.8 among 14- to 17-year-olds), and argument reporting (OR = 8.2 among 14- to 17-year-olds). Among older adolescents, the consumption of fruit fewer than five times per week (OR = 2.4), life dissatisfaction (OR = 2.8), underweight status (OR = 6.7), and overweight status (OR = 2.7) were associated with poor SRH. As adolescents age, their universe expands from their relationship with their parents to include more complex issues, such as their lifestyles and life satisfaction. Therefore, these results suggest the importance of evaluating SRH across adolescent age groups and demonstrate the influence of the

  19. A statistical method for estimating rates of soil development and ages of geologic deposits: A design for soil-chronosequence studies

    USGS Publications Warehouse

    Switzer, P.; Harden, J.W.; Mark, R.K.

    1988-01-01

    A statistical method for estimating rates of soil development in a given region based on calibration from a series of dated soils is used to estimate ages of soils in the same region that are not dated directly. The method is designed specifically to account for sampling procedures and uncertainties that are inherent in soil studies. Soil variation and measurement error, uncertainties in calibration dates and their relation to the age of the soil, and the limited number of dated soils are all considered. Maximum likelihood (ML) is employed to estimate a parametric linear calibration curve, relating soil development to time or age on suitably transformed scales. Soil variation on a geomorphic surface of a certain age is characterized by replicate sampling of soils on each surface; such variation is assumed to have a Gaussian distribution. The age of a geomorphic surface is described by older and younger bounds. This technique allows age uncertainty to be characterized by either a Gaussian distribution or by a triangular distribution using minimum, best-estimate, and maximum ages. The calibration curve is taken to be linear after suitable (in certain cases logarithmic) transformations, if required, of the soil parameter and age variables. Soil variability, measurement error, and departures from linearity are described in a combined fashion using Gaussian distributions with variances particular to each sampled geomorphic surface and the number of sample replicates. Uncertainty in age of a geomorphic surface used for calibration is described using three parameters by one of two methods. In the first method, upper and lower ages are specified together with a coverage probability; this specification is converted to a Gaussian distribution with the appropriate mean and variance. In the second method, "absolute" older and younger ages are specified together with a most probable age; this specification is converted to an asymmetric triangular distribution with mode at the

  20. Resting heart rate and the development of antisocial behavior from age 9 to 14: genetic and environmental influences.

    PubMed

    Baker, Laura A; Tuvblad, Catherine; Reynolds, Chandra; Zheng, Mo; Lozano, Dora Isabel; Raine, Adrian

    2009-01-01

    The genetic and environmental basis of a well-replicated association between antisocial behavior (ASB) and resting heart rate was investigated in a longitudinal twin study, based on two measurements between the ages of 9 and 14 years. ASB was defined as a broad continuum of externalizing behavior problems, assessed at each occasion through a composite measure based on parent ratings of trait aggression, delinquent behaviors, and psychopathic traits in their children. Parent ratings of ASB significantly decreased across age from childhood to early adolescence, although latent growth models indicated significant variation and twin similarity in the growth patterns, which were explained almost entirely by genetic influences. Resting heart rate at age 9-10 years old was inversely related to levels of ASB but not change patterns of ASB across age or occasions. Biometrical analyses indicated significant genetic influences on heart rate during childhood, as well as ASB throughout development from age 9 to 14. Both level and slope variation were significantly influenced by genetic factors. Of importance, the low resting heart rate and ASB association was significantly and entirely explained by their genetic covariation, although the heritable component of heart rate explained only a small portion (1-4%) of the substantial genetic variance in ASB. Although the effect size is small, children with low resting heart rate appear to be genetically predisposed toward externalizing behavior problems as early as age 9 years old.

  1. Air pollution and gene-specific methylation in the Normative Aging Study

    PubMed Central

    Bind, Marie-Abele; Lepeule, Johanna; Zanobetti, Antonella; Gasparrini, Antonio; Baccarelli, Andrea A; Coull, Brent A; Tarantini, Letizia; Vokonas, Pantel S; Koutrakis, Petros; Schwartz, Joel

    2014-01-01

    The mechanisms by which air pollution has multiple systemic effects in humans are not fully elucidated, but appear to include inflammation and thrombosis. This study examines whether concentrations of ozone and components of fine particle mass are associated with changes in methylation on tissue factor (F3), interferon gamma (IFN-γ), interleukin 6 (IL-6), toll-like receptor 2 (TLR-2), and intercellular adhesion molecule 1 (ICAM-1). We investigated associations between air pollution exposure and gene-specific methylation in 777 elderly men participating in the Normative Aging Study (1999–2009). We repeatedly measured methylation at multiple CpG sites within each gene’s promoter region and calculated the mean of the position-specific measurements. We examined intermediate-term associations between primary and secondary air pollutants and mean methylation and methylation at each position with distributed-lag models. Increase in air pollutants concentrations was significantly associated with F3, ICAM-1, and TLR-2 hypomethylation, and IFN-γ and IL-6 hypermethylation. An interquartile range increase in black carbon concentration averaged over the four weeks prior to assessment was associated with a 12% reduction in F3 methylation (95% CI: -17% to -6%). For some genes, the change in methylation was observed only at specific locations within the promoter region. DNA methylation may reflect biological impact of air pollution. We found some significant mediated effects of black carbon on fibrinogen through a decrease in F3 methylation, and of sulfate and ozone on ICAM-1 protein through a decrease in ICAM-1 methylation. PMID:24385016

  2. Gender differences in age-related decline in glomerular filtration rates in healthy people and chronic kidney disease patients

    PubMed Central

    2010-01-01

    Background Since men with chronic kidney disease (CKD) progress faster than women, an accurate assessment of CKD progression rates should be based on gender differences in age-related decline of glomerular filtration rate (GFR) in healthy individuals. Methods A Chinese sample population from a stratified, multistage, and clustered CKD screening study was classified into healthy, at-risk, and CKD groups. The gender differences in estimated GFR (eGFR) and age-related eGFR decline were calculated for each group after controlling for blood pressure, fasting glucose levels, serum lipids levels, education level, and smoking status. After referencing to the healthy group, gender-specific multivariate-adjusted rates of decline in eGFR and differences in the rates of decline were calculated for both CKD and at-risk groups. Results The healthy, at-risk, and CKD groups consisted of 4569, 7434, and 1573 people, respectively. In all the 3 groups, the multivariate-adjusted eGFRs in men were lower than the corresponding eGFRs in women. In addition, in the healthy and at-risk groups, the rates of decline in eGFR in men were lower than the corresponding rates of decline in women (healthy group: 0.51 mL·min-1·1.73 m-2·yr-1 vs. 0.74 mL·min-1·1.73 m-2·yr-1 and at-risk group: 0.60 mL·min-1·1.73 m-2·yr-1 vs. 0.73 mL·min-1·1.73 m-2·yr-1). However, in the CKD group, the rates of decline in eGFR in men were similar to those in women (0.96 mL·min-1·1.73 m-2·yr-1 vs. 0.91 mL·min-1·1.73 m-2·yr-1). However, after referencing to the healthy group, the rates of decline in eGFR in men in the at-risk and CKD groups were greater faster than the corresponding rates in women (at-risk group: 0.10 mL·min-1·1.73 m-2·yr-1 vs. -0.03 mL·min-1·1.73 m-2·yr-1 and CKD group: 0.44 mL·min-1·1.73 m-2·yr-1 vs. 0.15 mL·min-1·1.73 m-2·yr-1). Conclusion To accurately assess gender differences in CKD progression rates, gender differences in age-related decline in GFR should be considered

  3. Trends in Stage-Specific Incidence Rates for Urothelial Carcinoma of the Bladder in the United States: 1988 to 2006

    PubMed Central

    Nielsen, Matthew E.; Smith, Angela B.; Meyer, Anne-Marie; Kuo, Tzy-Mey; Tyree, Seth; Kim, William Y.; Milowsky, Matthew I.; Pruthi, Raj S.; Millikan, Robert C.

    2014-01-01

    BACKGROUND: Bladder cancer is notable for a striking heterogeneity of disease-specific risks. Among the approximately 75% of incident cases found to be superficial to the muscularis propria at the time of presentation (non-muscle-invasive bladder cancer), the risk of progression to the lethal phenotype of muscle-invasive disease is strongly associated with stage and grade of disease. Given the suggestion of an increasing percentage of low-risk cases in hospital-based registry data in recent years, the authors hypothesized that population-based data may reveal changes in the stage distribution of early-stage cases. METHODS: Surveillance, Epidemiology, and End Results (SEER) data were used to examine trends for the stage-specific incidence of bladder cancer between 1988 and 2006, adjusted for age, race, and sex, using Joinpoint and nonparametric tests. RESULTS: The adjusted incidence rate of papillary noninvasive (Ta) predominantly low grade (77%) disease was found to increase from 5.52 to 9.09 per 100,000 population (P <.0001), with an average annual percentage change of +3.3. Over the same period, concomitant, albeit smaller, decreases were observed for flat in situ (Tis) and lamina propria-invasive (T1) disease (2.57 to 1.19 and 6.65 to 4.61 per 100,000 population [both P <.0001]; average annual percent change of −5.0 and −1.6, respectively). The trend was most dramatic among patients in the oldest age strata, suggesting a previously unappreciated cohort phenomenon. CONCLUSIONS: The findings of the current study should motivate further epidemiological investigations of differential associations of genetic and environmental factors with different bladder cancer phenotypes as well as further scrutiny of clinical practice guideline recommendations for the growing subgroup of predominantly older patients with lower-risk disease. PMID:24122346

  4. Information Processing by School-Age Children with Specific Language Impairment: Evidence from a Modality Effect Paradigm.

    ERIC Educational Resources Information Center

    Gillam, Ronald B.; Cowan, Nelson; Marler, Jeffrey A.

    1998-01-01

    Sixteen school-age children with specific language impairment (SLI) and 16 age-matched controls were tested for immediate recall of digits presented visually, auditorily, or audiovisually. Recall tasks compared speaking and pointing response modalities. SLI children showed small recency effects as well as an unusually poor recall when visually…

  5. Fe /Fe oxide nanocomposite particles with large specific absorption rate for hyperthermia

    NASA Astrophysics Data System (ADS)

    Zeng, Q.; Baker, I.; Loudis, J. A.; Liao, Y.; Hoopes, P. J.; Weaver, J. B.

    2007-06-01

    Using a water-in-oil microemulsion with cetyl trimethyl ammonium bromide as the surfactant, iron was reduced to form a metallic core on which a passivating oxide shell was grown. Transmission electron microscopy, vibrating sample magnetometry, and heating measurements were used to characterize these monodispersed magnetic Fe /Fe3O4 composite nanoparticles with respect to the possible application for magnetic hyperthermia treatments of cancer. The aim is to utilize the fact that an iron core (high saturation magnetization) will give a greater heating effect than iron oxide, while the iron oxide coating will allow the nanoparticles to be observed using magnetic resonance imaging so that therapy can be effectively monitored and targeted. The largest specific absorption rate obtained was 345W/g under an alternating magnetic field of 150Oe at 250kHz.

  6. Specific absorption rate in models of man and monkey at 225 and 2000 MHz

    SciTech Connect

    Olsen, R.G.; Griner, T.A.

    1987-01-01

    Full-size models of a man and a rhesus monkey were exposed to radiofrequency (RF) radiation at 225 MHz. The model of man was also exposed to 2000 MHz. Specific absorption rates (SARs) were measured in partial-body sections, such as the arms, legs, etc., using gradient-layer calorimeters. Also, front-surface thermographic images were obtained to qualitatively show the heating patterns. For all of the configurations used, the SAR in the limbs was much higher than in the torso. Agreement (whole-body SARs) with spheroidal models was better for both models at 225 MHz than at 2000 MHz. These results indicate that in the frequency range two orders of magnitude above whole-body resonance, SAR in the limbs significantly contributes to the whole-body average SAR.

  7. Magnetic Nanoparticles with High Specific Absorption Rate at Low Alternating Magnetic Field

    PubMed Central

    Kekalo, K.; Baker, I.; Meyers, R.; Shyong, J.

    2015-01-01

    This paper describes the synthesis and properties of a new type of magnetic nanoparticle (MNP) for use in the hyperthermia treatment of tumors. These particles consist of 2–4 nm crystals of gamma-Fe2O3 gathered in 20–40 nm aggregates with a coating of carboxymethyl-dextran, producing a zetasize of 110–120 nm. Despite their very low saturation magnetization (1.5–6.5 emu/g), the specific absorption rate (SAR) of the nanoparticles is 22–200 W/g at applied alternating magnetic field (AMF) with strengths of 100–500 Oe at a frequency of 160 kHz. PMID:26884816

  8. Determination of ultimate carbonaceous BOD and the specific rate constant (K1)

    USGS Publications Warehouse

    Stamer, J.K.; Bennett, J.P.; McKenzie, Stuart W.

    1982-01-01

    Ultimate carbonaceous biochemical oxygen demand (BODu) and the specific rate constant (K1) at which the demand is exerted are important parameters in designing biological wastewater treatment plants and in assessing the impact of wastewater on receiving streams. An analytical method is presented which uses time-series concentrations of BOD, defined as the calculated sum of dissolved oxygen (DO) losses at each time of measurement, for determining BODu and K1. Time-series DO measurements are obtained from a water sample that is incubated in darkness at 20 degrees Celsius in the presence of nitrapyrin, a chemical nitrification inhibitor. Time-series concentrations of BOD that approximate first order kinetics can be analyzed graphically or mathematically to compute BODu and K1.

  9. MRI-based anatomical model of the human head for specific absorption rate mapping

    PubMed Central

    Makris, Nikos; Angelone, Leonardo; Tulloch, Seann; Sorg, Scott; Kaiser, Jonathan; Kennedy, David

    2009-01-01

    In this study, we present a magnetic resonance imaging (MRI)-based, high-resolution, numerical model of the head of a healthy human subject. In order to formulate the model, we performed quantitative volumetric segmentation on the human head, using T1-weighted MRI. The high spatial resolution used (1 × 1 × 1 mm3), allowed for the precise computation and visualization of a higher number of anatomical structures than provided by previous models. Furthermore, the high spatial resolution allowed us to study individual thin anatomical structures of clinical relevance not visible by the standard model currently adopted in computational bioelectromagnetics. When we computed the electromagnetic field and specific absorption rate (SAR) at 7 Tesla MRI using this high-resolution model, we were able to obtain a detailed visualization of such fine anatomical structures as the epidermis/dermis, bone structures, bone-marrow, white matter and nasal and eye structures. PMID:18985401

  10. THE SPECIFIC ACCELERATION RATE IN LOOP-STRUCTURED SOLAR FLARES-IMPLICATIONS FOR ELECTRON ACCELERATION MODELS

    SciTech Connect

    Guo, Jingnan; Emslie, A. Gordon; Piana, Michele E-mail: piana@dima.unige.it

    2013-03-20

    We analyze electron flux maps based on RHESSI hard X-ray imaging spectroscopy data for a number of extended coronal-loop flare events. For each event, we determine the variation of the characteristic loop length L with electron energy E, and we fit this observed behavior with models that incorporate an extended acceleration region and an exterior 'propagation' region, and which may include collisional modification of the accelerated electron spectrum inside the acceleration region. The models are characterized by two parameters: the plasma density n in, and the longitudinal extent L{sub 0} of, the acceleration region. Determination of the best-fit values of these parameters permits inference of the volume that encompasses the acceleration region and of the total number of particles within it. It is then straightforward to compute values for the emission filling factor and for the specific acceleration rate (electrons s{sup -1} per ambient electron above a chosen reference energy). For the 24 events studied, the range of inferred filling factors is consistent with a value of unity. The inferred mean value of the specific acceleration rate above E{sub 0} = 20 keV is {approx}10{sup -2} s{sup -1}, with a 1{sigma} spread of about a half-order-of-magnitude above and below this value. We compare these values with the predictions of several models, including acceleration by large-scale, weak (sub-Dreicer) fields, by strong (super-Dreicer) electric fields in a reconnecting current sheet, and by stochastic acceleration processes.

  11. The effect of mare's age on multiple ovulation rate, embryo recovery, post-transfer pregnancy rate, and interovulatory interval in a commercial embryo transfer program in Argentina.

    PubMed

    Marinone, A I; Losinno, L; Fumuso, E; Rodríguez, E M; Redolatti, C; Cantatore, S; Cuervo-Arango, J

    2015-07-01

    Advanced maternal age is an important predisposing factor on the reduction of reproductive efficiency. The aim of this study was to evaluate the effect of donor's age on several reproductive parameters in a commercial equine embryo transfer program. Donors were classified into 3 age groups: Group 1=fillies (3 and 4 years old), Group 2=middle age mares (aged 5-10) and Group 3=old mares (aged 13-25). Embryo recovery, multiple ovulation and pregnancy rates and interovulatory intervals were compared amongst age groups. Group 1 (171/244, 70.1%) and Group 2 (774/1081, 71.6%) had a higher (P<0.005) embryo recovery rate than Group 3 (385/701, 54.9%). Groups 2 and 3 were 2.5 and 3.4 times more likely to have multiple ovulations than Group 1 (P<0.05), respectively. The effect of age group on pregnancy rate was not significant (P>0.05). The interovulatory intervals length was influenced by individual mare (P<0.001), age (P<0.04), Day of flushing (P=0.009) and by month (P<0.012). The overall mean interovulatory interval of Group 1 (16.4±0.17 days) and Group 2 (16.6±0.12 days) was not different (P>0.05), but was shorter than the one of Group 3 (17.4±0.15 days; P<0.04). The embryo recovery rate of flushings from Groups 1 and 2 was influenced by the length of the previous interovulatory interval (P=0.03). PMID:25981675

  12. The effect of mare's age on multiple ovulation rate, embryo recovery, post-transfer pregnancy rate, and interovulatory interval in a commercial embryo transfer program in Argentina.

    PubMed

    Marinone, A I; Losinno, L; Fumuso, E; Rodríguez, E M; Redolatti, C; Cantatore, S; Cuervo-Arango, J

    2015-07-01

    Advanced maternal age is an important predisposing factor on the reduction of reproductive efficiency. The aim of this study was to evaluate the effect of donor's age on several reproductive parameters in a commercial equine embryo transfer program. Donors were classified into 3 age groups: Group 1=fillies (3 and 4 years old), Group 2=middle age mares (aged 5-10) and Group 3=old mares (aged 13-25). Embryo recovery, multiple ovulation and pregnancy rates and interovulatory intervals were compared amongst age groups. Group 1 (171/244, 70.1%) and Group 2 (774/1081, 71.6%) had a higher (P<0.005) embryo recovery rate than Group 3 (385/701, 54.9%). Groups 2 and 3 were 2.5 and 3.4 times more likely to have multiple ovulations than Group 1 (P<0.05), respectively. The effect of age group on pregnancy rate was not significant (P>0.05). The interovulatory intervals length was influenced by individual mare (P<0.001), age (P<0.04), Day of flushing (P=0.009) and by month (P<0.012). The overall mean interovulatory interval of Group 1 (16.4±0.17 days) and Group 2 (16.6±0.12 days) was not different (P>0.05), but was shorter than the one of Group 3 (17.4±0.15 days; P<0.04). The embryo recovery rate of flushings from Groups 1 and 2 was influenced by the length of the previous interovulatory interval (P=0.03).

  13. Growth rates and ages of deep-sea corals impacted by the Deepwater Horizon oil spill

    USGS Publications Warehouse

    Prouty, Nancy G.; Fisher, Charles R.; Demopoulos, Amanda W. J.; Druffel, Ellen R. M.

    2016-01-01

    The impact of the April 2010 Deepwater Horizon (DWH) spill on deep-sea coral communities in the Gulf of Mexico (GoM) is still under investigation, as is the potential for these communities to recover. Impacts from the spill include observation of corals covered with flocculent material, with bare skeleton, excessive mucous production, sloughing tissue, and subsequent colonization of damaged areas by hydrozoans. Information on growth rates and life spans of deep-sea corals is important for understanding the vulnerability of these ecosystems to both natural and anthropogenic perturbations, as well as the likely duration of any observed adverse impacts. We report radiocarbon ages and radial and linear growth rates based on octocorals (Paramuricea spp. and Chrysogorgia sp.) collected in 2010 and 2011 from areas of the DWH impact. The oldest coral radiocarbon ages were measured on specimens collected 11 km to the SW of the oil spill from the Mississippi Canyon (MC) 344 site: 599 and 55 cal yr BP, suggesting continuous life spans of over 600 years for Paramuricea biscaya, the dominant coral species in the region. Calculated radial growth rates, between 0.34 μm yr−1 and 14.20 μm yr−1, are consistent with previously reported proteinaceous corals from the GoM. Anomalously low radiocarbon (Δ14C) values for soft tissue from some corals indicate that these corals were feeding on particulate organic carbon derived from an admixture of modern surface carbon and a low 14C carbon source. Results from this work indicate fossil carbon could contribute 5–10% to the coral soft tissue Δ14C signal within the area of the spill impact. The influence of a low 14C carbon source (e.g., petro-carbon) on the particulate organic carbon pool was observed at all sites within 30 km of the spill site, with the exception of MC118, which may have been outside of the dominant northeast-southwest zone of impact. The quantitatively assessed extreme longevity and slow growth rates documented

  14. The Specific Star-formation Rates Of z 2 ULIRGs: DOGs And SMGs

    NASA Astrophysics Data System (ADS)

    Bussmann, R. Shane; Dey, A.; Desai, V.; Melbourne, J.; Soifer, B. T.

    2010-01-01

    The advent of the Spitzer Space Telescope has revolutionized the field of IR astronomy by resolving a significant fraction of the Cosmic IR background at wavelengths up to 160um. A new population of z 2 ULIRGs has been identified via the combination of Spitzer IR imaging with ground-based imaging in the optical. In this contribution, we undertake a systematic comparison of the intrinsic properties of an important subset of this population, dust-obscured galaxies (DOGs), and another z 2 ULIRG population that is well-studied, sub-millimeter galaxies (SMGs). We utilize far-IR + radio imaging of DOGs to estimate star formation rates and mid-IR + optical imaging to estimate stellar masses and thereby obtain specific star formation rates. We compare our results with predictions from hydrodynamical N-body simulations of quiescent and merging systems to place contraints on the relative evolutionary status of the 24um and sub-mm selected z 2 ULIRG populations.

  15. Mechanistic Insights into the Rate-Limiting Step in Purine-Specific Nucleoside Hydrolase.

    PubMed

    Chen, Nanhao; Zhao, Yuan; Lu, Jianing; Wu, Ruibo; Cao, Zexing

    2015-07-14

    A full enzymatic catalysis cycle in the inosine-adenosine-guanosine specific nucleoside hydrolase (IAG-NH) was assumed to be comprised of four steps: substrate binding, chemical reaction, base release, and ribose