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Sample records for age specific rates

  1. 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)

  2. Age-Specific Morbidity and Mortality Rates Among U.S. Navy Enlisted Divers and Controls

    DTIC Science & Technology

    1984-07-01

    The purpose of this study was to compare age-specific hospitalization, disability, and mortality rates for diving-related and stress- induced...actions for stress-related disorders were observed among controls than divers. For both groups, medical board, physical evaluation board, and mortality ... rates increased with age as did hospitalization for musculoskeletal disorders, stress-related disorders, and circulatory diseases. Subsequent research

  3. Effects of Maternal Age and Age-Specific Preterm Birth Rates on Overall Preterm Birth Rates - United States, 2007 and 2014.

    PubMed

    Ferré, Cynthia; Callaghan, William; Olson, Christine; Sharma, Andrea; Barfield, Wanda

    2016-11-04

    Reductions in births to teens and preterm birth rates are two recent public health successes in the United States (1,2). From 2007 to 2014, the birth rate for females aged 15-19 years declined 42%, from 41.5 to 24.2 per 1,000 females. The preterm birth rate decreased 8.4%, from 10.41% to 9.54% of live births (1). Rates of preterm births vary by maternal age, being higher among the youngest and oldest mothers. It is unknown how changes in the maternal age distribution in the United States have affected preterm birth rates. CDC used birth data to assess the relative contributions of changes in the maternal age distribution and in age-specific preterm birth rates to the overall decrease in preterm birth rates. The preterm birth rate declined in all age groups. The effects of age distribution changes on the preterm birth rate decrease were different in younger and older mothers. The decrease in the proportion of births to mothers aged ≤19 and 20-24 years and reductions in age-specific preterm rates in all age groups contributed to the overall decline in the preterm birth rate. The increase in births to mothers aged ≥30 years had no effect on the overall preterm birth rate decrease. The decline in preterm births from 2007 to 2014 is related, in part, to teen pregnancy prevention and the changing maternal age distribution. Effective public health strategies for further reducing preterm birth rates need to be tailored to different age groups.

  4. 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

  5. Method for projecting age-specific mortality rates for certain causes of death

    SciTech Connect

    Leggett, R.W.; Crawford, D.J.

    1981-01-01

    A method is presented for projecting mortality rates for certain causes on the basis of observed rates during past years. This method arose from a study of trends in age-specific mortality rates for respiratory cancers, and for heuristic purposes it is shown how the method can be developed from certain theories of cancer induction. However, the method is applicable in the more common situation in which the underlying physical processes cannot be modeled with any confidence but the mortality rates are approximable over short time intervals by functions of the form a exp(bt), where b may vary in a continuous, predictable fashion as the time interval is varied. It appears from applications to historical data that this projection method is in some cases a substantial improvement over conventional curve-fitting methods and often uncovers trends which are not apparent from observed data.

  6. A method for projecting age-specific mortality rates for certain causes of death

    SciTech Connect

    Leggett, R.W.; Crawford, D.J.

    1981-09-01

    A method is presented for projecting mortality rates for certain causes on the basis of observed rates during past years. This method arose from a study of trends in age-specific mortality rates for respiratory cancers, and for heuristic purposes it is shown how the method can be developed from certain theories of cancer induction. However, the method is applicable in the more common situation in which the underlying physical processes cannot be modeled with any confidence but the mortality rates are approximable over short time intervals by functions of the form a exp(bt), where b may vary in a continuous, predictable fashion as the time interval is varied. It appears from applications to historical data that this projection method is in some cases a substantial improvement over conventional curve-fitting methods and often uncovers trends which are not from observed data.

  7. Age-Related Differences of Organism-Specific Peritonitis Rates: A Single-Center Experience.

    PubMed

    Kotera, Nagaaki; Tanaka, Mototsugu; Aoe, Mari; Chikamori, Masatomo; Honda, Tomoko; Ikenouchi, Ayako; Miura, Rika; Sugahara, Mai; Furuse, Satoshi; Saito, Katsunori; Mise, Naobumi

    2016-12-01

    Peritonitis remains an important cause of morbidity and mortality in peritoneal dialysis (PD) patients, but its incidence and the distribution of causative organisms vary widely between institutions and age groups. This study was performed to investigate the recent status and risk factors of PD-related peritonitis and to clarify differences between age groups. We retrospectively reviewed the medical records of 119 PD patients treated at our department between January 2002 and January 2013. We calculated both overall and organism-specific peritonitis rates and also analyzed risk factors. Sixty-three episodes of peritonitis occurred during 261.5 patient-years for an incident rate of 0.24 episodes/patient-year. Multivariate analysis showed that older age (≥65 years) and hypoalbuminemia (<3.0 g/dL) were associated with an increased risk of peritonitis (P = 0.035 and P = 0.029, respectively). In elderly patients (≥65 years old), the rate of peritonitis due to Gram-positive and Gram-negative bacteria was 0.17 and 0.08 episodes/patient-year, respectively, and Gram-positive peritonitis was markedly more frequent than in younger patients (<65 years old). In particular, there was a high frequency of Staphylococcus aureus peritonitis in elderly patients (0.09 episodes/patient-year) and it had a poor outcome. At our department, the risk of peritonitis was increased in older patients and patients with hypoalbuminemia. The distribution of causative organisms was markedly different between age groups and analysis of organism-specific peritonitis rates helped to identify current problems with our PD program.

  8. Age-Specific Variation in Adult Mortality Rates in Developed Countries

    PubMed Central

    Zheng, Hui; Yang, Y. Claire; Land, Kenneth C.

    2016-01-01

    This paper investigates historical changes in both single-year-of-age adult mortality rates and variation of the single-year mortality rates around expected values within age intervals over the past two centuries in 15 developed countries. We apply an integrated Hierarchical Age-Period-Cohort—Variance Function Regression Model to data from the Human Mortality Database. We find increasing variation of the single-year rates within broader age intervals over the life course for all countries, but the increasing variation slows down at age 90 and then increases again after age 100 for some countries; the variation significantly declined across cohorts born after the early 20th century; and the variation continuously declined over much of the last two centuries but has substantially increased since 1980. Our further analysis finds the recent increases in mortality variation are not due to increasing proportions of older adults in the population, trends in mortality rates, or disproportionate delays in deaths from degenerative and man-made diseases, but rather due to increasing variations in young and middle-age adults. PMID:28133402

  9. Comparison of age- and sex-specific incidence rate patterns of the leukemia complex in the cat and the dog.

    PubMed

    Schneider, R

    1983-05-01

    Data on cancer cases in cats and dogs were collected systematically by the Animal Neoplasm Registry of Alameda and Contra Costa Counties, Calif., a population-based animal tumor registry. Etiologic relationships were evaluated on the basis of comparisons of age-specific, sex-specific, and age-neutered-specific incidence rate patterns of the leukemias. Age-adjusted annual incidence rates for all leukemias per 100,000 cats or dogs were 224.3 and 30.5, respectively. The cat had 6.1 times more malignant lymphomas and 15.7 times more myeloproliferative disease than the dog. Feline age-specific rates indicated a bimodal age pattern for all leukemias and for malignant lymphoma alone and a single early peak for myeloproliferative disease. In the dog, all age-specific patterns increased with age and peaked later in life. Feline sex-specific, age-adjusted rates showed that the neutered female was at lowest risk, followed by the neutered male, entire female, and entire male. In the dog, the neutered male was at lowest risk while the other three sex categories were clustered. However, the magnitude of expression within each species separately was the same for the neutered male, entire male, and entire female, but not for the neutered female. Neutering decreased the risk of leukemias in the female cat by approximately one-half but did not affect the risk of leukemias in the female dog.

  10. Age-Specific Incidence Rates for Norovirus in the Community and Presenting to Primary Healthcare Facilities in the United Kingdom

    PubMed Central

    O'Brien, Sarah J.; Donaldson, Anna L.; Iturriza-Gomara, Miren; Tam, Clarence C.

    2016-01-01

    In a prospective, population-based cohort study and a study of primary-healthcare consultations, we had a rare opportunity to estimate age-specific rates of norovirus-associated infectious intestinal disease in the United Kingdom. Rates in children aged <5 years were significantly higher than those for other age groups in the community (142.6 cases per 1000 person-years [95% confidence interval {CI}, 99.8–203.9] vs 37.6 [95% CI, 31.5–44.7]) and those for individuals presenting to primary healthcare (14.4 cases per 1000 person-years [95% CI, 8.5–24.5] vs 1.4 [95% CI, .9–2.0]). Robust incidence estimates are crucial for vaccination policy makers. This study emphasises the impact of norovirus-associated infectious intestinal disease, especially in children aged <5 years. PMID:26744427

  11. 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

  12. 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

  13. 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, John 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).

  14. 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…

  15. Multiple Metazoan Life-span Interventions Exhibit a Sex-specific Strehler-Mildvan Inverse Relationship Between Initial Mortality Rate and Age-dependent Mortality Rate Acceleration.

    PubMed

    Shen, Jie; Landis, Gary N; Tower, John

    2017-01-01

    The Gompertz equation describes survival in terms of initial mortality rate (parameter a), indicative of health, and age-dependent acceleration in mortality rate (parameter b), indicative of aging. Gompertz parameters were analyzed for several published studies. In Drosophila females, mating increases egg production and decreases median life span, consistent with a trade-off between reproduction and longevity. Mating increased parameter a, causing decreased median life span, whereas time parameter b was decreased. The inverse correlation between parameters indicates the Strehler-Mildvan (S-M) relationship, where loss of low-vitality individuals yields a cohort with slower age-dependent mortality acceleration. The steroid hormone antagonist mifepristone/RU486 reversed these effects. Mating and mifepristone showed robust S-M relationships across genotypes, and dietary restriction showed robust S-M relationship across diets. Because nutrient optima differed between females and males, the same manipulation caused opposite effects on mortality rates in females versus males across a range of nutrient concentrations. Similarly, p53 mutation in Drosophila and mTOR mutation in mice caused increased median life span associated with opposite direction changes in mortality rate parameters in females versus males. The data demonstrate that dietary and genetic interventions have sex-specific and sometimes sexually opposite effects on mortality rates consistent with sexual antagonistic pleiotropy.

  16. 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)

  17. 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.

  18. 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

  19. Maternal Age-Specific Rates for Trisomy 21 and Common Autosomal Trisomies in Fetuses from a Single Diagnostic Center in Thailand

    PubMed Central

    Jaruthamsophon, Kanoot; Sriplung, Hutcha; Charalsawadi, Chariyawan

    2016-01-01

    To provide maternal age-specific rates for trisomy 21 (T21) and common autosomal trisomies (including trisomies 21, 18 and 13) in fetuses. We retrospectively reviewed prenatal cytogenetic results obtained between 1990 and 2009 in Songklanagarind Hospital, a university teaching hospital, in southern Thailand. Maternal age-specific rates of T21 and common autosomal trisomies were established using different regression models, from which only the fittest models were used for the study. A total of 17,819 records were included in the statistical analysis. The fittest models for predicting rates of T21 and common autosomal trisomies were regression models with 2 parameters (Age and Age2). The rate of T21 ranged between 2.67 per 1,000 fetuses at the age of 34 and 71.06 per 1,000 at the age of 48. The rate of common autosomal trisomies ranged between 4.54 per 1,000 and 99.65 per 1,000 at the same ages. This report provides the first maternal age-specific rates for T21 and common autosomal trisomies fetuses in a Southeast Asian population and the largest case number of fetuses have ever been reported in Asians. PMID:27812158

  20. Standardization of age-adjusted mortality rates

    SciTech Connect

    Selvin, S.; Sacks, S.T.; Merrill, D.W.

    1980-02-01

    Because age is a significant variable in the occurrence and frequency of human disease, any comparison of disease or mortality rates, to be useful, must be age-specific or age-adjusted. Age-specific comparisons are not always appropriate or possible, however. A common method of eliminating the influence of age in comparing mortality rates from one community to another is to employ statistical methods of age-adjustment. While a variety of methods will accomplish this task, most are weighted averages of the age-specific rates. Two widely used adjustment procedures are direct and indirect age-adjustment.

  1. Avian growth and development rates and age-specific mortality: the roles of nest predation and adult mortality.

    PubMed

    Remes, V

    2007-01-01

    Previous studies have shown that avian growth and development covary with juvenile mortality. Juveniles of birds under strong nest predation pressure grow rapidly, have short incubation and nestling periods, and leave the nest at low body mass. Life-history theory predicts that parental investment increases with adult mortality rate. Thus, developmental traits that depend on the parental effort exerted (pre- and postnatal growth rate) should scale positively with adult mortality, in contrast to those that do not have a direct relationship with parental investment (timing of developmental events, e.g. nest leaving). I tested this prediction on a sample of 84 North American songbirds. Nestling growth rate scaled positively and incubation period duration negatively with annual adult mortality rates even when controlled for nest predation and other covariates, including phylogeny. On the contrary, neither the duration of the nestling period nor body mass at fledging showed any relationship. Proximate mechanisms generating the relationship of pre- and postnatal growth rates to adult mortality may include increased feeding, nest attentiveness during incubation and/or allocation of hormones, and deserve further attention.

  2. Age-Specific Morbidity among Navy Pilots

    DTIC Science & Technology

    1983-10-01

    categories. Younger pilots have the highest rates for disorders of tooth development and eruption and accidental ...rates among aviation officers for accidental injuries were attributed prim.arily to athletic or sports activities. Comparisons of hospitalizations...important age-specific health problems (i.e., accidental injuries among young pilots and cardiovascular conditions among older pilots). In order for

  3. Sex-specific and race-specific hip fracture rates.

    PubMed Central

    Kellie, S E; Brody, J A

    1990-01-01

    Sex-, race- and age-specific hip fracture rates were determined using Health Care Financing Administration data for Medicare-reimbursed hip fracture hospitalizations from 1980 to 1982. Rates were highest in White women, lowest in Black men, and intermediate in White men and Black women. Proportions of hip fracture patients dying during hospitalization and those discharged to nursing homes, respectively, were: White men (10.5%; 49%); Black men (9.3%; 32%); White women (5.0%; 54%); and Black women (8.2%; 30%). PMID:2305917

  4. 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)].

  5. Age-specific bone tumour incidence rates are governed by stem cell exhaustion influencing the supply and demand of progenitor cells.

    PubMed

    Richardson, Richard B

    2014-07-01

    Knudson's carcinogenic model, which simulates incidence rates for retinoblastoma, provides compelling evidence for a two-stage mutational process. However, for more complex cancers, existing multistage models are less convincing. To fill this gap, I hypothesize that neoplasms preferentially arise when stem cell exhaustion creates a short supply of progenitor cells at ages of high proliferative demand. To test this hypothesis, published datasets were employed to model the age distribution of osteochondroma, a benign lesion, and osteosarcoma, a malignant one. The supply of chondrogenic stem-like cells in femur growth plates of children and adolescents was evaluated and compared with the progenitor cell demand of longitudinal bone growth. Similarly, the supply of osteoprogenitor cells from birth to old age was compared with the demands of bone formation. Results show that progenitor cell demand-to-supply ratios are a good risk indicator, exhibiting similar trends to the unimodal and bimodal age distributions of osteochondroma and osteosarcoma, respectively. The hypothesis also helps explain Peto's paradox and the finding that taller individuals are more prone to cancers and have shorter lifespans. The hypothesis was tested, in the manner of Knudson, by its ability to convincingly explain and demonstrate, for the first time, a bone tumour's bimodal age-incidence curve.

  6. Quantifying the risk of sports injury: a systematic review of activity‐specific rates for children under 16 years of age

    PubMed Central

    Spinks, Anneliese B; McClure, Roderick J

    2007-01-01

    Injuries caused by sports and other forms of physical activity in young children constitute a significant public health burden. It is important to quantify this risk to ensure that the benefits of sport participation are not outweighed by the potential harms. This review summarises the literature reporting exposure‐based injury rates for various forms of physical activity in children aged 15 years and younger. Forty eight studies were found, of which 27 reported injury rates per hourly based exposure measured and 21 reported injury rates according to some other measure. Fourteen different sports and activities were covered, mostly team ball sports, with soccer being the most widely studied. Injury definition and the method of ascertaining and measuring injuries differed between studies, which created a large variation in reported injury rates that did not necessarily represent actual differences in injury risk between activities. The highest hourly based injury rates were reported for ice hockey, and the lowest were for soccer, although the range of injury rates for both of these activities was wide. Very few studies have investigated sports‐related injuries in children younger than 8 years or in unorganised sports situations. PMID:17473004

  7. 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

  8. The utility of age-specific cut-offs for visual rating of medial temporal atrophy in classifying Alzheimer's disease, MCI and cognitively normal elderly subjects

    PubMed Central

    Duara, Ranjan; Loewenstein, David A.; Shen, Qian; Barker, Warren; Varon, Daniel; Greig, Maria T.; Curiel, Rosie; Agron, Joscelyn; Santos, Isael; Potter, Huntington

    2013-01-01

    Background: New research criteria for diagnosing Alzheimer's disease (AD) in the mild cognitive impairment stage (MCI-AD) incorporate biomarkers to assign a level of certainty to the diagnosis. Structural MRI is widely available but greatly under-utilized for assessing atrophy of structures affected in early AD, such as the hippocampus (HP), because the quantification of HP volumes (HP-v) requires special expertise, and normative values have not been established. Methods: Elderly subjects (n =273) from the Florida ADRC were classified as having no cognitive impairment (cognitively normal, CN), amnestic mild cognitive impairment (aMCI) or AD. Volumes for the hippocampus (HP-v) were measured on structural MRI scans. A validated visual rating system for measuring medial temporal atrophy (VRS-MTA), including hippocampal, entorhinal cortex and perirhinal cortex atrophy was employed. The participants were subdivided into younger (less than or equal to 75 years of age) and older (greater than 75 years of age) subgroups. Results: Volumetric and VRS-MTA measures were equivalent in predicting classification of CN vs. aMCI for older (area under the receiver operator curves [aROC]: 0.652 vs. 0.723) and younger subjects (aROC: 0.764 vs. 0.736). However, for younger AD subjects, aROC values were significantly higher for VRS-MTA measures (0.920) than for volumetric measures (0.847). Relative to HP-v, VRS-MTA score was significantly more correlated to impairment on a range of memory tests and was more associated with progression of aMCI to AD than HP-v. Conclusion: Structural MRI with VRS-MTA assessment can serve as a biomarker for supporting the diagnosis of MCI-AD. Age-adjusted VRS-MTA scores are at least as effective as HP-v for distinguishing aMCI and AD from CN and for predicting progression from aMCI to AD. VRS-MTA is convenient for use in the clinic as well as for clinical trials and can readily be incorporated into a standardized radiological report. PMID:24065917

  9. 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...

  10. 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...

  11. Age-Specific Correlates of Child Growth.

    PubMed

    Rieger, Matthias; Trommlerová, Sofia Karina

    2016-02-01

    Growth faltering describes a widespread phenomenon that height- and weight-for-age of children in developing countries collapse rapidly in the first two years of life. We study age-specific correlates of child nutrition using Demographic and Health Surveys from 56 developing countries to shed light on the potential drivers of growth faltering. Applying nonparametric techniques and exploiting within-mother variation, we find that maternal and household factors predict best the observed shifts and bends in child nutrition age curves. The documented interaction between age and maternal characteristics further underlines the need not only to provide nutritional support during the first years of life but also to improve maternal conditions.

  12. Pulsed-wave Doppler tissue imaging velocities in normal geriatric cats and geriatric cats with primary or systemic diseases linked to specific cardiomyopathies in humans, and the influence of age and heart rate upon these velocities.

    PubMed

    Simpson, Kerry E; Gunn-Moore, Danièlle A; Shaw, Darren J; French, Anne T; Dukes-McEwan, Joanna; Moran, Carmel M; Corcoran, Brendan M

    2009-04-01

    Pulsed-wave Doppler tissue imaging (pw-DTI) techniques allow the non-invasive assessment of myocardial dynamics. pw-DTI has demonstrated regional and global diastolic impairment in various forms of human and feline cardiomyopathy. We hypothesise that in geriatric cats with systemic diseases that have been linked to specific cardiomyopathies in human beings, the myocardial velocity profile will be altered when compared to either normal or hypertrophic cardiomyopathy (HCM) cats; and that both age and heart rate have a significant affect upon pw-DTI velocities. The aims of this study were to determine whether the feline M-mode or myocardial velocity profile is altered in geriatric cats with disease states that have been linked to specific cardiomyopathies in humans when compared to normal geriatric cats or geriatric cats with HCM and to determine whether age or heart rate has a significant effect upon pw-DTI velocities within these groups of cats. Sixty-six cats aged 8 years or above were included in the study, and were divided as follows: Unaffected (n=8), basilar septal bulge (BSB) (17), HCM (14), hyperthyroid (HiT(4)) (12) and chronic renal failure (CRF) (15). Systolic blood pressure was normal in all the cats. pw-DTI systolic (S'), early (E') and late diastolic (A') velocities were assessed from standardised sites within the myocardium, and the relationships between these and disease group, age and heart rate were then assessed. In cats with HCM, the E' velocity was decreased at various sites. Conversely, the HiT(4) cats demonstrated increased S' velocities. The only site at which the age of the cat was significantly related to myocardial velocities was the S' velocity from the apical mid-septum. There were also significant positive relationships between heart rate and the magnitude of myocardial S', E' and A' velocities of radial motion and S' and A' velocities of longitudinal motion. pw-DTI detected diastolic dysfunction in untreated cats with HCM and increased

  13. Age-Specific Morbidity Among Naval Aviators.

    DTIC Science & Technology

    1983-01-01

    health problems (i.e., accidental injuries among young pilots and cardiovascular conditions among older pilots). In order for the Navy’s medical de...conditions. With increasing age, differences in rates for most categories narrowed substantially across groups although rates for accidental injuries...order to ensure the pilot’s and aircrew member’s total concentration during flight. The higher rates among aviation officers for accidental injuries

  14. 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.

  15. Antioxidants, metabolic rate and aging in Drosophila.

    PubMed

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

    1982-09-01

    In line with the (metabolic) rate-of-living theory of aging, previous work from this laboratory showed that the life-prolonging effect of the antioxidant thiazolidine carboxylic acid (TCA) in Drosophila was paralleled by a similar reduction of the oxygen consumption rate of the flies. To assess the generality of this phenomenon, several life-prolonging antioxidants were dietarily administered to the flies (in standard medium with 1% w/v of tocopherol-stripped corn oil) and their effects on metabolic rate and life span were determined. Respiration rate of groups of continuously agitated flies was measured in the Gilson respirometer. The studied antioxidants were as follows: (the numbers in parentheses are consecutively the antioxidant concentration in the medium in % wt/vol.; mean life span in days; and metabolic rate in microliter O2/mg fly per 24 h): vitamin E (0.4; 46.3; 58.5); 2,4-dinitrophenol (0.1; 45.7; 66.2); nordihydroguaiaretic acid (0.5; 45.6; 69.1); thiazolidine carboxylic acid (0.3; 53.1; 55.8); and control with no antioxidant added (0; 40.7; 73.3). All of these antioxidants at the tested concentrations reduced oxygen consumption rate and increased mean life span; there was a significant negative linear correlation (r = -0.87) between mean life span and metabolic rate. These data suggest that some antioxidants may inhibit respiration rate in addition to their protective effect against free radical-induced cellular damage.

  16. 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.

  17. 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…

  18. Age-and Brain Region-Specific Differences in Mitochondrial ...

    EPA Pesticide Factsheets

    Mitochondria are central regulators of energy homeostasis and play a pivotal role in mechanisms of cellular senescence. The objective of the present study was to evaluate mitochondrial bio­-energetic parameters in five brain regions [brainstem (BS), frontal cortex (FC), cerebellum (CER), striatum (STR), hippocampus (HIP)] of four diverse age groups [1 Month (young), 4 Month (adult), 12 Month (middle-aged), 24 Month (old age)] to understand age-related differences in selected brain regions and their contribution to age-related chemical sensitivity. Mitochondrial bioenergetics parameters and enzyme activity were measured under identical conditions across multiple age groups and brain regions in Brown Norway rats (n = 5). The results indicate age- and brain region-specific patterns in mitochondrial functional endpoints. For example, an age-specific decline in ATP synthesis (State 111 respiration) was observed in BS and HIP. Similarly, the maximal respiratory capacities (State V1 and V2) showed age-specific declines in all brain regions examined (young > adult > middle-aged > old age). Amongst all regions, HIP had the greatest change in mitochondrial bioenergetics, showing declines in the 4, 12 and 24 Month age groups. Activities of mitochondrial pyruvate dehydrogenase complex (PDHC) and electron transport chain (ETC) complexes I, II, and IV enzymes were also age- and brain-region specific. In general changes associated with age were more pronounced, with

  19. Suicide rates: age-associated trends and their correlates

    PubMed Central

    Shah, Ajit

    2012-01-01

    Abstract: Background: Suicide rates traditionally increased with ageing. There is a paucity of studies examining factors associated with age-associated trends in suicide rates. Methods: The relationship between suicide rates and ageing was examined by ascertaining suicide rates in the seven age-bands 16-24 years to 75+ years from the World Health Organisation for 97 countries. The relationship between socio-economic status, income inequality, healthcare expenditure, child mortality rates and life expectancy and countries with an increase, a decline and no change in suicide rates with ageing was examined using data from the United Nations. Results: In males and females there was a decline in 5 and 10 countries, an increase in 33 and 37 countries and no change in 59 and 50 countries respectively in suicide rates with ageing. Age-associated trends in suicide rates were significantly associated with socio-economic status (males) or income inequality (females), per capita expenditure in healthcare, the proportion of gross-national domestic product spent on healthcare, child mortality rates and life expectancy. Conclusion: The current study, of factors associated with age-associated trends in suicide rates, confirmed a previously developed five sequential stage model to explain the relationship between elderly suicide rates and socio-economic status and income inequality, quality and quantity of healthcare services, child mortality rates and life expectancy. PMID:21502781

  20. Inter-provincial migration in Spain: temporal trends and age-specific patterns.

    PubMed

    Garcia Coll, A; Stillwell, J

    1999-01-01

    "This paper provides interpretation of the changing patterns of internal migration in Spain at the inter-provincial scale, and new analysis of age-specific migration during the 1980s using a 10% sample of anonymised records from the 1991 census. Schedules of age-specific gross migration rates are constructed and classified according to their shape and level relative to the national schedule, and the relationships between in-migration and out-migration rates are examined for four selected age groups to demonstrate how aggregate patterns of inter-provincial migration conceal a wide diversity of age specific experience."

  1. Estimating survival rates with age-structure data

    USGS Publications Warehouse

    Udevitz, M.S.; Ballachey, B.E.

    1998-01-01

    We developed a general statistical model that provides a comprehensive framework for inference about survival rates based on standing age-structure and ages-at-death data. Previously available estimators are maximum likelihood under the general model, but they use only 1 type of data and require the assumption of a stable age structure and a known population growth rate. We used the general model to derive new survival rate estimators that use both types of data and require only the assumption of a stable age structure or a known population growth rate. Our likelihood-based approach allows use of standard model-selection procedures to test hypotheses about age-structure stability, population growth rates, and age-related patterns in survival. We used this approach to estimate survival rates for female sea otters (Enhydra lutris) in Prince William Sound, Alaska.

  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. Age-specific mortality among advanced-age Chinese citizens and its difference between the two genders.

    PubMed

    Gan, J; Zheng, Z; Li, G

    1998-01-01

    This study describes the patterns of age-specific mortality among the elderly in China. Data were obtained from the 1990 census. The age groups ending in zero were validated with the Weber Index and found to be of good quality among those aged under 97 years. Differences were found between censuses and genders. The data for the aged were adjusted with 2-year moving averages in order to smooth the data. The end age of interval mortality is used. Tables provide single years of age between 60 years and 104 years by sex for the actual number and the adjusted number of each census year: 1953, 1964, 1982, and 1990. The pattern of change in age specific mortality rates (ASMRs) was similar in all census years. Mortality rates were highest among infants aged under 1 year, declined with increased age, and were lowest among 10 year olds. Mortality rose gradually after 10 years and sharply after 40-50 years. ASMRs were "U" shaped. Age-specific interval mortality rates among the elderly show that mortality increased drastically as it approached 90 years of age and then grew more slowly or declined. The Gompers rule about exponential increases among the extremely old (over 90 years) does not apply. Male mortality was higher than female mortality until the very old ages, which showed lower male mortality. The ratio declined with rising age until the two genders were equal. Mortality rose to a point and then declined to a lesser extent. The peak was 93 years in 1953, with a sex ratio (SR) of 32.48; 90 years in 1964, with an SR of 35.22; 93 years in 1982, with an SR of 35.96; and 95 years in 1990, with an SR of 32.94.

  4. Structure and Age Jointly Influence Rates of Protein Evolution

    PubMed Central

    Toll-Riera, Macarena; Bostick, David; Albà, M. Mar; Plotkin, Joshua B.

    2012-01-01

    What factors determine a protein's rate of evolution are actively debated. Especially unclear is the relative role of intrinsic factors of present-day proteins versus historical factors such as protein age. Here we study the interplay of structural properties and evolutionary age, as determinants of protein evolutionary rate. We use a large set of one-to-one orthologs between human and mouse proteins, with mapped PDB structures. We report that previously observed structural correlations also hold within each age group – including relationships between solvent accessibility, designabililty, and evolutionary rates. However, age also plays a crucial role: age modulates the relationship between solvent accessibility and rate. Additionally, younger proteins, despite being less designable, tend to evolve faster than older proteins. We show that previously reported relationships between age and rate cannot be explained by structural biases among age groups. Finally, we introduce a knowledge-based potential function to study the stability of proteins through large-scale computation. We find that older proteins are more stable for their native structure, and more robust to mutations, than younger ones. Our results underscore that several determinants, both intrinsic and historical, can interact to determine rates of protein evolution. PMID:22693443

  5. Age effects on atrophy rates of entorhinal cortex and hippocampus

    PubMed Central

    Du, An-Tao; Schuff, Norbert; Chao, Linda L.; Kornak, John; Jagust, William J.; Kramer, Joel H.; Reed, Bruce R.; Miller, Bruce L.; Norman, David; Chui, Helena C.; Weiner, Michael W.

    2007-01-01

    The effects of age, subcortical vascular disease, apolipoprotein E (APOE) ɛ4 allele and hypertension on entorhinal cortex (ERC) and hippocampal atrophy rates were explored in a longitudinal MRI study with 42 cognitively normal (CN) elderly subjects from 58 to 87 years old. The volumes of the ERC, hippocampus, and white matter hyperintensities (WMH) and the presence of lacunes were assessed on MR images. Age was significantly associated with increased atrophy rates of 0.04 ± 0.02% per year for ERC and 0.05 ± 0.02% per year for hippocampus. Atrophy rates of hippocampus, but not that of ERC increased with presence of lacunes, in addition to age. WMH, APOE ɛ4 and hypertension had no significant effect on atrophy rates. In conclusion, age and presence of lacunes should be taken into consideration in imaging studies of CN subjects and AD patients to predict AD progression and assess the response to treatment trials. PMID:15961190

  6. Age Differences in Recollection: Specificity Effects at Retrieval

    ERIC Educational Resources Information Center

    Luo, Lin; Craik, Fergus I. M.

    2009-01-01

    Three experiments were conducted to examine the effect of specificity at retrieval on the size of age differences in recollection. Participants encoded words in different contexts and were given recognition tests. Some of the test lists were constructed so that participants had to recollect specific aspects of the initial encoding events, whereas…

  7. Age-specific MRI templates for pediatric neuroimaging

    PubMed Central

    Sanchez, Carmen E.; Richards, John E.; Almli, C. Robert

    2012-01-01

    This study created a database of pediatric age-specific MRI brain templates for normalization and segmentation. Participants included children from 4.5 through 19.5 years, totaling 823 scans from 494 subjects. Open-source processing programs (FSL, SPM, ANTS) constructed head, brain and segmentation templates in 6 month intervals. The tissue classification (WM, GM, CSF) showed changes over age similar to previous reports. A volumetric analysis of age-related changes in WM and GM based on these templates showed expected increase/decrease pattern in GM and an increase in WM over the sampled ages. This database is available for use for neuroimaging studies (blindedforreview). PMID:22799759

  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. 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

  10. 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.

  11. 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...

  12. 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

    2016-05-03

    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.

  13. 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.

  14. 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.

  15. Decelerating Mortality Rates in Older Ages and its Prospects through Lee-Carter Approach

    PubMed Central

    Yadav, Awdhesh; Yadav, Suryakant; Kesarwani, Ranjana

    2012-01-01

    The present study attempts to study the age pattern mortality and prospects through Lee-Carter approach. The objectives of the study are to examine the trend of mortality decline and life expectancy. Contemporaneously, we have projected life expectancy up to 2025, projecting ASDR using Lee-Carter method. Life table aging rate (LAR) used to estimate the rate of mortality deceleration. Overtime, LAR increased and during recent decade it remained more or less unchanged. By age, LAR significant increased in the oldest of old. The slope is steepest in the oldest of old in the recent decade. The rates of mortality increased in oldest of old as the age group is more vulnerable to chronic disease and vulnerable to identifiable risk factors for virtually every disease, marked by senility. The analysis revealed that the level of mortality is not declining but rate of acceleration is declining and is further expected to decline. By the year 2025, the age specific death rates for the age group 5–9 and 10–14 will go below one per thousand.Life expectancy will attained as high as 73 and 79 years for male and female and is further expected to increase linearly. 71 percent of total female birth and 57 percent of total male birth will survive up to age 70+. Also the findings revealed that mortality rate is declining with constant rate up to age 70 and thereafter, the mortality rate accelerates and this holds true for both sexes. PMID:23236414

  16. 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

  17. 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…

  18. The Relationship between Age Structure and Homicide Rates in the United States, 1970 to 1999

    ERIC Educational Resources Information Center

    Phillips, Julie A.

    2006-01-01

    The nature of the temporal association between age structure and homicide rates between 1970 and 1999 is examined using U.S. county data. Specifically, the following questions are asked: (a) does the strong temporal association between the relative size of the young population and homicide rates demonstrated at the U.S. national level hold at a…

  19. 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.

  20. 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…

  1. Low income, unemployment, and suicide mortality rates for middle-age persons in Japan.

    PubMed

    Yamasaki, Akiko; Sakai, Ryoji; Shirakawa, Taro

    2005-04-01

    The relationships between age-specific suicide mortality rates and social life factors for all 47 Japanese prefectures in 1980, 1985, and 1990 were assessed by multiple regression analysis after factor analysis on 20 social life indicators. During this period, Japan experienced a secondary oil crisis in 1980-1983 and a bubble economy in 1986-1990. It was concluded that (1) low income was the major determinant which positively affected suicide mortality rate in middle-aged men during a previous 20-yr. period (1970-1990), (2) urbanization was negatively associated with male suicide mortality rates in most of the age classes in the 1980s, (3) unemployment was one of the major determinants of increased suicide mortality rate in middle-age men in the 1980s, and (4) unemployment was the major factor which was inversely associated with suicide mortality rate for elderly women from 1980 to 1990 in Japan.

  2. Recommendations for the treatment of aging in standard technical specifications

    SciTech Connect

    Orton, R.D.; Allen, R.P.

    1995-09-01

    As part of the US Nuclear Regulatory Commission`s Nuclear Plant Aging Research Program, Pacific Northwest Laboratory (PNL) evaluated the standard technical specifications for nuclear power plants to determine whether the current surveillance requirements (SRs) were effective in detecting age-related degradation. Nuclear Plant Aging Research findings for selected systems and components were reviewed to identify the stressors and operative aging mechanisms and to evaluate the methods available to detect, differentiate, and trend the resulting aging degradation. Current surveillance and testing requirements for these systems and components were reviewed for their effectiveness in detecting degraded conditions and for potential contributions to premature degradation. When the current surveillance and testing requirements appeared ineffective in detecting aging degradation or potentially could contribute to premature degradation, a possible deficiency in the SRs was identified that could result in undetected degradation. Based on this evaluation, PNL developed recommendations for inspection, surveillance, trending, and condition monitoring methods to be incorporated in the SRs to better detect age- related degradation of these selected systems and components.

  3. Changing pattern of age-specific breast cancer incidence in the Swiss canton of Geneva.

    PubMed

    Bouchardy, Christine; Usel, Massimo; Verkooijen, Helena M; Fioretta, Gérald; Benhamou, Simone; Neyroud-Caspar, Isabelle; Schaffar, Robin; Vlastos, Georges; Wespi, Yves; Schäfer, Peter; Rapiti, Elisabetta

    2010-04-01

    Hormone replacement therapy (HRT) use declined sharply after mid-2002, when the Women's Health Initiative trial reported an association between breast cancer occurrence and HRT. Hypothesized mechanism behind this association is that HRT promotes growth of pre-existing small tumors, leading to earlier tumor detection. We evaluated the impact of the sudden decline in HRT use on age distribution of breast cancer in Geneva. We included all incident breast cancer cases recorded from 1975 to 2006 at the Geneva cancer registry. We calculated mean annual incidence rates per 100,000 for 2 year periods for three age groups and assessed temporal changes by joinpoint regression. We compared age-specific incidence curves for different periods, reflecting different prevalence rates of HRT use. After increasing constantly between 1986 and 2002 among women aged 50-69 years [annual percent change (APC): +4.4, P < 0.0001], rates declined sharply after 2003 (APC: -6.0; P = 0.0264). Age-specific breast cancer rates changed dramatically with changes in prevalence of HRT use. During low HRT prevalence, breast cancer incidence increased progressively with age, when HRT prevalence was reaching its maximum (1995-2002), higher rates were seen in 60- to 64-year-old women, with a concomitant decrease in risk among elderly. After the sudden decline in HRT use, the incidence peak diminished significantly and incidence increased again with age. Following the abrupt decline in HRT use in Geneva, breast cancer incidence rates among post-menopausal women decreased considerably with striking changes in age-specific incidence rates before, during and after the peak in HRT prevalence.

  4. 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.

  5. Age-Of Dependent Mutation Rate and Weak Children in the Penna Model in Biological Ageing

    NASA Astrophysics Data System (ADS)

    Berntsen, K. Nikolaj

    We investigate the effect of an age-dependent mutation rate in the Penna model of ageing and then we observe that the high mortality for human babies can be reproduced by the model if one assumes babies to be weaker than adults.

  6. 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

  7. Reading multifractal spectra: Aging by multifractal analysis of heart rate

    NASA Astrophysics Data System (ADS)

    Makowiec, D.; Rynkiewicz, A.; Gałaska, R.; Wdowczyk-Szulc, J.; Żarczyńska-Buchowiecka, M.

    2011-06-01

    The method of effective reading of multifractal properties is proposed. The method consists in the analysis of a given signal together with the analysis of an integrated signal. A practical way to separate monofractal-type signals from other signals is given. The method is applied to 24-hour ECG recordings of RR-interbeat intervals to assess the effect of aging on autonomic regulation of the heart in healthy adults. Heart rate variability is evaluated by multifractal analysis in the VLF band. A switch from mono- to multifractality is observed between diurnal and nocturnal parts of series in the group of young adults. With aging the multifractal structure of nocturnal signals declines. The observed changes can be related to the circadian alternation in the central mechanisms controlling the cardiovascular system which becomes impaired with advance in age in human. Indices for age impairment of autonomic regulation are proposed.

  8. Online aging study of a high rate MRPC

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Wang, Yi; Feng, S. Q.; Xie, Bo; Lv, Pengfei; Wang, Fuyue; Guo, Baohong; Han, Dong; Li, Yuanjing

    2016-05-01

    With the constant increase of accelerator luminosity, the rate requirements of MRPC detectors have become very important, and the aging characteristics of the detector have to be studied meticulously. An online aging test system has been set up in our lab, and in this paper the setup of the system is described and the performance stability of a high-rate MRPC studied over a long running time under a high luminosity environment. The high rate MRPC was irradiated by X-rays for 36 days and the accumulated charge density reached 0.1 C/cm2. No obvious performance degradation was observed for the detector. Supported by National Natural Science Foundation of China (11420101004, 11461141011, 11275108), Ministry of Science and Technology (2015CB856905)

  9. 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.

  10. Slowing of mortality rates at older ages in large medfly cohorts.

    PubMed

    Carey, J R; Liedo, P; Orozco, D; Vaupel, J W

    1992-10-16

    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.

  11. Molecular dating, evolutionary rates, and the age of the grasses.

    PubMed

    Christin, Pascal-Antoine; Spriggs, Elizabeth; Osborne, Colin P; Strömberg, Caroline A E; Salamin, Nicolas; Edwards, Erika J

    2014-03-01

    Many questions in evolutionary biology require an estimate of divergence times but, for groups with a sparse fossil record, such estimates rely heavily on molecular dating methods. The accuracy of these methods depends on both an adequate underlying model and the appropriate implementation of fossil evidence as calibration points. We explore the effect of these in Poaceae (grasses), a diverse plant lineage with a very limited fossil record, focusing particularly on dating the early divergences in the group. We show that molecular dating based on a data set of plastid markers is strongly dependent on the model assumptions. In particular, an acceleration of evolutionary rates at the base of Poaceae followed by a deceleration in the descendants strongly biases methods that assume an autocorrelation of rates. This problem can be circumvented by using markers that have lower rate variation, and we show that phylogenetic markers extracted from complete nuclear genomes can be a useful complement to the more commonly used plastid markers. However, estimates of divergence times remain strongly affected by different implementations of fossil calibration points. Analyses calibrated with only macrofossils lead to estimates for the age of core Poaceae ∼51-55 Ma, but the inclusion of microfossil evidence pushes this age to 74-82 Ma and leads to lower estimated evolutionary rates in grasses. These results emphasize the importance of considering markers from multiple genomes and alternative fossil placements when addressing evolutionary issues that depend on ages estimated for important groups.

  12. 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.

  13. Specific Rate of Protein Crystallization Determined by the Guggenheim Method

    NASA Astrophysics Data System (ADS)

    Baird, James K.; McFeeters, Robert L.; Caraballo, Katiuska G.

    2014-05-01

    The biological function of a protein is intimately related to its three-dimensional molecular structure. Although X-ray diffraction from single crystals can be employed to solve for the molecular structure, use of this method is often impeded by the slow rate of precipitation of crystals from the pH buffered, aqueous solutions of strong electrolytes which ordinarily serve as growth media. The rate of crystallization can be measured as a function of growth solution conditions by growing the crystals in a dilatometer. As the crystallization progresses, the rate of change of the system volume caused by the difference in density between the crystals and the solution is reflected in the rate of change of the height of the fluid in the capillary side arm of the dilatometer. In the case of the proteins, lysozyme, and canavalin, this height changes exponentially with time, which serves to define a first-order rate constant or specific crystallization rate, k. A dozen such experiments may be needed to determine how depends upon pH, electrolyte concentration, and temperature. Each experiment can require 4 or 5 days to reach equilibrium. If height measurements are made equally spaced in time, however, early time data can be combined according to the Guggenheim procedure, and the value of k can be determined without the experiment having to reach equilibrium. By using this method, the time required to complete an experiment can be reduced by as much as 50 %.

  14. 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…

  15. Endogenous endothelin-1and femoral artery shear rate: impact of age and implications for atherosclerosis

    PubMed Central

    Trinity, Joel D.; Barrett-O’Keefe, Zachary; Ives, Stephen J.; Morgan, Garrett; Rossman, Matthew J.; Donato, Anthony J.; Runnels, Sean; Morgan, David E.; Gmelch, Benjamin S.; Bledsoe, Amber D.; Richardson, Russell S.; Wray, D. Walter

    2017-01-01

    Background Both altered shear rate and endothelin-1 (ET-1) are associated with the age-related development of atherosclerosis. However, the role of ET-1, a potent endogenous vasoconstrictor, in altering shear rate in humans, especially in the atherosclerotic-prone vasculature of the leg, is unknown. Therefore, this study examined the contribution of ET-1 to the age-related alterations in common femoral artery (CFA) shear rate. Method BQ-123, a specific endothelin type A (ETA) receptor antagonist, was infused into the CFA, and diameter and blood velocity were measured by Doppler ultrasound in young (n = 8, 24 ± 2 years) and old (n = 9, 70 ± 2 years) study participants. Results and conclusion The old had greater intima–media thickening in the CFA, indicative of a preatherogenic phenotype. Prior to infusion, the old study participants exhibited reduced mean shear rate (27 ± 3/s) compared with the young study participants (62 ± 9/s). This difference was likely driven by attenuated antegrade shear rate in the old as retrograde shear rate was similar in the young and old. Inhibition of ETA receptors, by BQ-123, increased leg blood flow in the old, but not in the young, abolishing age-related differences. Older study participants had a larger CFA (young: 0.82 ± 0.03 cm, old: 0.99 ± 0.03 cm) in which BQ-123 induced significant vasodilation (5.1 ± 1.0%), but had no such effect in the young (−0.8 ± 0.8%). Interestingly, despite the age-specific, BQ-123-induced increase in leg blood flow and CFA diameter, shear rate patterns remained largely unchanged. Therefore, ET-1, acting through the ETA receptors, exerts a powerful age-specific vasoconstriction. However, removal of this vasoconstrictor stimulus does not augment mean shear rate in the old. PMID:26599223

  16. Age at first reproduction and growth rate are independent of basal metabolic rate in mammals.

    PubMed

    Lovegrove, Barry G

    2009-05-01

    This study tested an emergent prediction from the Metabolic Theory of Ecology (MTE) that the age at first reproduction (alpha) of a mammal is proportional to the inverse of its mass-corrected basal metabolic rate: alpha proportional (B / M)-1 The hypothesis was tested with multiple regression models of conventional species data and phylogenetically independent contrasts of 121 mammal species. Since age at first reproduction is directly influenced by an individual's growth rate, the hypothesis that growth rate is proportional to BMR was also tested. Although the overall multiple regression model was significant, age at first reproduction was not partially correlated with either body mass, growth rate or BMR. Similarly, growth rate was not correlated with BMR. Thus at least for mammals in general, there is no evidence to support the fundamental premise of the MTE that individual metabolism governs the rate at which energy is converted to growth and reproduction at the species level. The exponents of the BMR allometry calculated using phylogenetic generalized least squares regression models were significantly lower than the three-quarter value predicted by the MTE.

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

    PubMed

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

    2014-02-07

    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.

  18. Rates and predictors of remission in young women with specific phobia: a prospective community study.

    PubMed

    Trumpf, Julia; Becker, Eni S; Vriends, Noortje; Meyer, Andrea H; Margraf, Jürgen

    2009-10-01

    This prospective study reports rates and predictors of remission in young women with specific phobia. Data came from a prospective community study, in which German women (aged 18-25 years) completed an extended version of the Anxiety Disorders Interview Schedule (ADIS-IV-L) at two time points. Of the 137 women with specific phobia at baseline, 41.6% were partially remitted and an additional 19.0% were fully remitted at follow-up, defined as absence of any specific fears. A remitting course of specific phobia was predicted by residual protective factors at baseline, especially participants' positive mental health and life satisfaction. Baseline levels of stress, coping skills, cognitive factors, psychopathology, and specific phobia characteristics did not predict remission. Results show that specific phobia in young women rarely takes a stable course at the full diagnostic threshold. The factors that influence remission of specific phobia are different from those that predict the incidence.

  19. Societal integration and age-standardized suicide rates in 21 developed countries, 1955-1989.

    PubMed

    Fernquist, R M; Cutright, P

    1998-01-01

    Gender-specific age-standardized suicide rates for 21 developed countries over seven 5-year periods (1955-59...1985-89) form the two dependent variables. Durkheim's theory of societal integration is the framework used to generate the independent variables, although several recent theories are also examined. The results from a MGLS multiple regression analysis of both male and female rates provide overwhelming support for a multidimensional theory of societal integration and suicide, as first suggested by Durkheim.

  20. Bunch mode specific rate corrections for PILATUS3 detectors

    DOE PAGES

    Trueb, P.; Dejoie, C.; Kobas, M.; ...

    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

  1. 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.

  2. 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

  3. Modeling Neisseria meningitidis B metabolism at different specific growth rates.

    PubMed

    Baart, Gino J E; Willemsen, Marieke; Khatami, Elnaz; de Haan, Alex; Zomer, Bert; Beuvery, E Coen; Tramper, Johannes; Martens, Dirk E

    2008-12-01

    Neisseria meningitidis is a human pathogen that can infect diverse sites within the human host. The major diseases caused by N. meningitidis are responsible for death and disability, especially in young infants. At the Netherlands Vaccine Institute (NVI) a vaccine against serogroup B organisms is currently being developed. This study describes the influence of the growth rate of N. meningitidis on its macro-molecular composition and its metabolic activity and was determined in chemostat cultures. In the applied range of growth rates, no significant changes in RNA content and protein content with growth rate were observed in N. meningitidis. The DNA content in N. meningitidis was somewhat higher at the highest applied growth rate. The phospholipid and lipopolysaccharide content in N. meningitidis changed with growth rate but no specific trends were observed. The cellular fatty acid composition and the amino acid composition did not change significantly with growth rate. Additionally, it was found that the PorA content in outer membrane vesicles was significantly lower at the highest growth rate. The metabolic fluxes at various growth rates were calculated using flux balance analysis. Errors in fluxes were calculated using Monte Carlo Simulation and the reliability of the calculated flux distribution could be indicated, which has not been reported for this type of analysis. The yield of biomass on substrate (Y(x/s)) and the maintenance coefficient (m(s)) were determined as 0.44 (+/-0.04) g g(-1) and 0.04 (+/-0.02) g g(-1) h(-1), respectively. The growth associated energy requirement (Y(x/ATP)) and the non-growth associated ATP requirement for maintenance (m(ATP)) were estimated as 0.13 (+/-0.04) mol mol(-1) and 0.43 (+/-0.14) mol mol(-1) h(-1), respectively. It was found that the split ratio between the Entner-Doudoroff and the pentose phosphate pathway, the sole glucose utilizing pathways in N. meningitidis, had a minor effect on ATP formation rate but a major

  4. 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.

  5. 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.

  6. 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.

  7. Region-Specific Genetic Alterations in the Aging Hippocampus: Implications For Cognitive Aging

    PubMed Central

    Burger, Corinna

    2010-01-01

    Aging is associated with cognitive decline in both humans and animals and of all brain regions, the hippocampus appears to be particularly vulnerable to senescence. Age-related spatial learning deficits result from alterations in hippocampal connectivity and plasticity. These changes are differentially expressed in each of the hippocampal fields known as cornu ammonis 1 (CA1), cornu ammonis 3 (CA3), and the dentate gyrus. Each sub-region displays varying degrees of susceptibility to aging. For example, the CA1 region is particularly susceptible in Alzheimer's disease while the CA3 region shows vulnerability to stress and glucocorticoids. Further, in animals, aging is the main factor associated with the decline in adult neurogenesis in the dentate gyrus. This review discusses the relationship between region-specific hippocampal connectivity, morphology, and gene expression alterations and the cognitive deficits associated with senescence. In particular, data are reviewed that illustrate how the molecular changes observed in the CA1, CA3, and dentate regions are associated with age-related learning deficits. This topic is of importance because increased understanding of how gene expression patterns reflect individual differences in cognitive performance is critical to the process of identifying new and clinically useful biomarkers for cognitive aging. PMID:21048902

  8. Region-specific genetic alterations in the aging hippocampus: implications for cognitive aging.

    PubMed

    Burger, Corinna

    2010-01-01

    Aging is associated with cognitive decline in both humans and animals and of all brain regions, the hippocampus appears to be particularly vulnerable to senescence. Age-related spatial learning deficits result from alterations in hippocampal connectivity and plasticity. These changes are differentially expressed in each of the hippocampal fields known as cornu ammonis 1 (CA1), cornu ammonis 3 (CA3), and the dentate gyrus. Each sub-region displays varying degrees of susceptibility to aging. For example, the CA1 region is particularly susceptible in Alzheimer's disease while the CA3 region shows vulnerability to stress and glucocorticoids. Further, in animals, aging is the main factor associated with the decline in adult neurogenesis in the dentate gyrus. This review discusses the relationship between region-specific hippocampal connectivity, morphology, and gene expression alterations and the cognitive deficits associated with senescence. In particular, data are reviewed that illustrate how the molecular changes observed in the CA1, CA3, and dentate regions are associated with age-related learning deficits. This topic is of importance because increased understanding of how gene expression patterns reflect individual differences in cognitive performance is critical to the process of identifying new and clinically useful biomarkers for cognitive aging.

  9. 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.

  10. 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.

  11. Prey behavior, age-dependent vulnerability, and predation rates.

    PubMed

    Lingle, Susan; Feldman, Alex; Boyce, Mark S; Wilson, W Finbarr

    2008-11-01

    Variation in the temporal pattern of vulnerability can provide important insights into predator-prey relationships and the evolution of antipredator behavior. We illustrate these points with a system that has coyotes (Canis latrans) as a predator and two species of congeneric deer (Odocoileus spp.) as prey. The deer employ different antipredator tactics (aggressive defense vs. flight) that result in contrasting patterns of age-dependent vulnerability in their probability of being captured when encountered by coyotes. We use long-term survival data and a simple mathematical model to show that (1) species differences in age-dependent vulnerability are reflected in seasonal predation rates and (2) seasonal variation in prey vulnerability and predator hunt activity, which can be associated with the availability of alternative prey, interact to shape seasonal and annual predation rates for each prey species. Shifting hunt activity from summer to winter, or vice versa, alleviated annual mortality on one species and focused it on the other. Our results indicate that seasonal variation in prey vulnerability and hunt activity interact to influence the impact that a predator has on any particular type of prey. Furthermore, these results indicate that seasonal variation in predation pressure is an important selection pressure shaping prey defenses.

  12. Human actuarial aging increases faster when background death rates are lower: a consequence of differential heterogeneity?

    PubMed

    Hawkes, Kristen; Smith, Ken R; Blevins, James K

    2012-01-01

    Many analyses of human populations have found that age-specific mortality rates increase faster across most of adulthood when overall mortality levels decline. This contradicts the relationship often expected from Williams' classic hypothesis about the effects of natural selection on the evolution of senescence. More likely, much of the within-species difference in actuarial aging is not due to variation in senescence, but to the strength of filters on the heterogeneity of frailty in older survivors. A challenge to this differential frailty hypothesis was recently posed by an analysis of life tables from historical European populations and traditional societies that reported variation in actuarial aging consistent with Williams' hypothesis after all. To investigate the challenge, we reconsidered those cases and aging measures. Here we show that the discrepancy depends on Ricklefs' aging rate measure, ω, which decreases as mortality levels drop because it is an index of mortality level itself, not the rate of increase in mortality with age. We also show unappreciated correspondence among the parameters of Gompertz-Makeham and Weibull survival models. Finally, we compare the relationships among mortality parameters of the traditional societies and the historical series, providing further suggestive evidence that differential heterogeneity has strong effects on actuarial aging.

  13. 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.

  14. Developmentally Sensitive Markers of Personality Functioning in Adolescents: Age-Specific and Age-Neutral Expressions.

    PubMed

    Debast, Inge; Rossi, Gina; Feenstra, Dineke; Hutsebaut, Joost

    2016-05-23

    Criterion D of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association [APA], 2013) refers to a possible onset of personality disorders (PDs) in adolescence and in Section II the development/course in adolescence is described by some typical characteristics for several PDs. Yet, age-specific expressions of PDs are lacking in Section III. We urgently need a developmentally sensitive assessment instrument that differentiates developmental and contextual changes on the one hand from expressions of personality pathology on the other hand. Therefore we investigated which items of the Severity Indices for Personality Problems-118 (SIPP-118) were developmentally sensitive throughout adolescence and adulthood and which could be considered more age-specific markers requiring other content or thresholds over age groups. Applying item response theory (IRT) we detected differential item functioning (DIF) in 36% of the items in matched samples of 639 adolescents versus 639 adults. The DIF across age groups mainly reflected a different degree of symptom expressions for the same underlying level of functioning. The threshold for exhibiting symptoms given a certain degree of personality dysfunction was lower in adolescence for areas of personality functioning related to the Self and Interpersonal domains. Some items also measured a latent construct of personality functioning differently across adolescents and adults. This suggests that several facets of the SIPP-118 do not solely measure aspects of personality pathology in adolescents, but likely include more developmental issues. (PsycINFO Database Record

  15. Modeling age-specific cancer incidences using logistic growth equations: implications for data collection.

    PubMed

    Shen, Xing-Rong; Feng, Rui; Chai, Jing; Cheng, Jing; Wang, De-Bin

    2014-01-01

    Large scale secular registry or surveillance systems have been accumulating vast data that allow mathematical modeling of cancer incidence and mortality rates. Most contemporary models in this regard use time series and APC (age-period-cohort) methods and focus primarily on predicting or analyzing cancer epidemiology with little attention being paid to implications for designing cancer registry, surveillance or evaluation initiatives. This research models age-specific cancer incidence rates using logistic growth equations and explores their performance under different scenarios of data completeness in the hope of deriving clues for reshaping relevant data collection. The study used China Cancer Registry Report 2012 as the data source. It employed 3-parameter logistic growth equations and modeled the age-specific incidence rates of all and the top 10 cancers presented in the registry report. The study performed 3 types of modeling, namely full age-span by fitting, multiple 5-year- segment fitting and single-segment fitting. Measurement of model performance adopted adjusted goodness of fit that combines sum of squred residuals and relative errors. Both model simulation and performance evalation utilized self-developed algorithms programed using C# languade and MS Visual Studio 2008. For models built upon full age-span data, predicted age-specific cancer incidence rates fitted very well with observed values for most (except cervical and breast) cancers with estimated goodness of fit (Rs) being over 0.96. When a given cancer is concerned, the R valuae of the logistic growth model derived using observed data from urban residents was greater than or at least equal to that of the same model built on data from rural people. For models based on multiple-5-year-segment data, the Rs remained fairly high (over 0.89) until 3-fourths of the data segments were excluded. For models using a fixed length single-segment of observed data, the older the age covered by the corresponding

  16. A Web Tool for Age-Period-Cohort Analysis of Cancer Incidence and Mortality Rates

    PubMed Central

    Rosenberg, Philip S.; Check, David P.; Anderson, William F.

    2014-01-01

    BACKGROUND Age-period-cohort (APC) analysis can inform registry-based studies of cancer incidence and mortality, but concerns about statistical identifiability and interpretability, as well as the learning curves of statistical software packages, have limited its uptake. METHODS We implemented a panel of easy-to-interpret estimable APC functions and corresponding Wald tests in R code that can be accessed through a user-friendly web tool. RESULTS Input data for the web tool consist of age-specific numbers of events and person-years over time, in the form of a rate matrix of paired columns. Output functions include model-based estimators of cross-sectional and longitudinal age-specific rates; period and cohort rate ratios that incorporate the overall annual percentage change (net drift); and estimators of the age-specific annual percentage change (local drifts). The web tool includes built-in examples for teaching and demonstration. User data can be input from a Microsoft Excel worksheet or by uploading a comma-separated-value (csv) file. Model outputs can be saved in a variety of formats including R and Excel. CONCLUSIONS APC methodology can now be carried out through a freely-available user-friendly web tool. The tool can be accessed at http://analysistools.nci.nih.gov/apc/. IMPACT The web tool can help cancer surveillance researchers make important discoveries about emerging cancer trends and patterns. PMID:25146089

  17. 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.

  18. 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.

  19. [Ageing rate in workers of mechanic workshops of machinery construction industry in Armenia].

    PubMed

    Sarkisian, G T; Barkhudarov, M S; Kogan, V Iu

    2004-01-01

    Studies of biologic age formation and ageing rate in workers of mechanic workshops revealed that able-bodied population grew old demographically. That is proved by absent age group of 20-29 years and increased share of able-bodied workers older than 50. Young workers aged 30-39 appeared the most vulnerable for occupational hazards--they demonstrated increased ageing rate and maximal excess of biologic age over chronological age and due biologic age.

  20. Determinants of intra-specific variation in basal metabolic rate.

    PubMed

    Konarzewski, Marek; Książek, Aneta

    2013-01-01

    Basal metabolic rate (BMR) provides a widely accepted benchmark of metabolic expenditure for endotherms under laboratory and natural conditions. While most studies examining BMR have concentrated on inter-specific variation, relatively less attention has been paid to the determinants of within-species variation. Even fewer studies have analysed the determinants of within-species BMR variation corrected for the strong influence of body mass by appropriate means (e.g. ANCOVA). Here, we review recent advancements in studies on the quantitative genetics of BMR and organ mass variation, along with their molecular genetics. Next, we decompose BMR variation at the organ, tissue and molecular level. We conclude that within-species variation in BMR and its components have a clear genetic signature, and are functionally linked to key metabolic process at all levels of biological organization. We highlight the need to integrate molecular genetics with conventional metabolic field studies to reveal the adaptive significance of metabolic variation. Since comparing gene expressions inter-specifically is problematic, within-species studies are more likely to inform us about the genetic underpinnings of BMR. We also urge for better integration of animal and medical research on BMR; the latter is quickly advancing thanks to the application of imaging technologies and 'omics' studies. We also suggest that much insight on the biochemical and molecular underpinnings of BMR variation can be gained from integrating studies on the mammalian target of rapamycin (mTOR), which appears to be the major regulatory pathway influencing the key molecular components of BMR.

  1. 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.

  2. 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

  3. 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

  4. Trends in hip fracture rates in Canada: an age-period-cohort analysis.

    PubMed

    Jean, Sonia; O'Donnell, Siobhan; Lagacé, Claudia; Walsh, Peter; Bancej, Christina; Brown, Jacques P; Morin, Suzanne; Papaioannou, Alexandra; Jaglal, Susan B; Leslie, William D

    2013-06-01

    Age-standardized rates of hip fracture in Canada declined during the period 1985 to 2005. We investigated whether this incidence pattern is explained by period effects, cohort effects, or both. All hospitalizations during the study period with primary diagnosis of hip fracture were identified. Age- and sex-specific hip fracture rates were calculated for nineteen 5-year age groups and four 5-year calendar periods, resulting in 20 birth cohorts. The effect of age, calendar period, and birth cohort on hip fracture rates was assessed using age-period-cohort models as proposed by Clayton and Schiffers. From 1985 to 2005, a total of 570,872 hospitalizations for hip fracture were identified. Age-standardized rates for hip fracture have progressively declined for females and males. The annual linear decrease in rates per 5-year period were 12% for females and 7% for males (both p < 0.0001). Significant birth cohort effects were also observed for both sexes (p < 0.0001). Cohorts born before 1950 had a higher risk of hip fracture, whereas those born after 1954 had a lower risk. After adjusting for age and constant annual linear change (drift term common to both period and cohort effects), we observed a significant nonlinear birth cohort effect for males (p = 0.0126) but not for females (p = 0.9960). In contrast, the nonlinear period effect, after adjustment for age and drift term, was significant for females (p = 0.0373) but not for males (p = 0.2515). For males, we observed no additional nonlinear period effect after adjusting for age and birth cohort, whereas for females, we observed no additional nonlinear birth cohort effect after adjusting for age and period. Although hip fracture rates decreased in both sexes, different factors may explain these changes. In addition to the constant annual linear decrease, nonlinear birth cohort effects were identified for males, and calendar period effects were identified for females as possible explanations.

  5. 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.

  6. Age-specific response of a migratory bird to an experimental alteration of its habitat.

    PubMed

    Haché, Samuel; Villard, Marc-André

    2010-07-01

    1. Recruitment, i.e. the influx of new breeding individuals into a population, is an important demographic parameter, especially in species with a short life span. Few studies have measured this parameter in solitary-breeding animal populations even though it may yield critical information on habitat suitability and functional connectivity. 2. Using a before-after, control-impact pairs (BACIP) experimental design, we measured: (i) the return rate and apparent survival rate of individually marked territorial males of a neotropical migrant bird species, the Ovenbird Seiurus aurocapilla Linnaeus and (ii) the age-specific recruitment rate. Study plots (n = 10) were paired: one was treated through single-tree selection harvesting (30-40% basal area removal) and the other acted as a control. We hypothesized that experienced males would out-compete inexperienced ones and tend to avoid settling in lower-quality, treated stands. 3. In the first year post-harvest, the mean density of territorial males was significantly lower in treated plots (-41%) than in controls and the difference remained relatively stable thereafter. This lower density mainly reflected a lower recruitment rate compared to controls (17.9 vs. 49.0% of males present), itself driven by a lower recruitment rate of experienced males (2.8 vs. 22.8%). Return rate was similar between controls and treated plots in the first year post-harvest (59 vs. 55%, respectively) but it decreased in treated plots during the second (-15.8% relative to controls) and third (-12.7%) year post-harvest. The trend was even stronger when considering only experienced males. The treatment was followed by a major expansion in mean territory size in treated plots (+49% relative to controls, 3rd year post-treatment). 4. Neither apparent survival rate nor recruitment rate varied as predicted. There was a strong year effect but no treatment effect on apparent survival rate, whereas male recruitment patterns were both year- and age-specific

  7. 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.

  8. Pupillary Response as an Age-Specific Measure of Sexual Interest.

    PubMed

    Attard-Johnson, Janice; Bindemann, Markus; Ó Ciardha, Caoilte

    2016-05-01

    In the visual processing of sexual content, pupil dilation is an indicator of arousal that has been linked to observers' sexual orientation. This study investigated whether this measure can be extended to determine age-specific sexual interest. In two experiments, the pupillary responses of heterosexual adults to images of males and females of different ages were related to self-reported sexual interest, sexual appeal to the stimuli, and a child molestation proclivity scale. In both experiments, the pupils of male observers dilated to photographs of women but not men, children, or neutral stimuli. These pupillary responses corresponded with observer's self-reported sexual interests and their sexual appeal ratings of the stimuli. Female observers showed pupil dilation to photographs of men and women but not children. In women, pupillary responses also correlated poorly with sexual appeal ratings of the stimuli. These experiments provide initial evidence that eye-tracking could be used as a measure of sex-specific interest in male observers, and as an age-specific index in male and female observers.

  9. 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

  10. Age-Specific Frequencies and Characteristics of Ovarian Cysts in Children and Adolescents

    PubMed Central

    Emeksiz, Hamdi Cihan; Derinöz, Okşan; Akkoyun, Esra Betül; Güçlü Pınarlı, Faruk; Bideci, Aysun

    2017-01-01

    Objective: The aim of the present study was to document ovarian cyst frequency and characteristics as well as distribution of these parameters with respect to age in children and adolescents. Methods: We retrospectively analyzed the medical records of 1009 girls between the ages of 5-18 years who presented to our pediatric emergency department (PED) with pelvic pain and therefore underwent pelvic ultrasound examination between June 2011 and May 2014. Results: In total, 132 of 1009 girls (13.1%) were identified as having ovarian cysts ≥1 cm in diameter. The frequency of ovarian cysts was found to be 1.8% (6/337) in children aged 5-9 years and 18.8% (126/672) in those aged 10-18 years. All the cysts detected in children aged 5-9 years were small (<3 cm) and simple with age-specific frequencies ranging between 1.5-2.7%. With the onset of adolescence, ovarian cyst frequency started to increase with age and ranged between 3.8-31.3% throughout adolescence. Age of peak ovarian cyst frequency was 15 years with a rate of 31.3%. Large ovarian cysts (>5 cm) were identified in 19 adolescents (15.1%) with most occurring during middle adolescence. Of the 19 adolescents, five were found to have cyst-related significant ovarian pathologies including cystadenoma (n=3) and ovarian torsion (n=2). Conclusion: In children aged 5-9 years, ovarian cysts were infrequent and small (<3 cm). Peak ovarian cyst frequency was detected at the age of 15 years. All patients diagnosed with cyst-related significant ovarian pathologies were adolescents having a cyst >5 cm in diameter with a complex appearance in most. PMID:28044991

  11. 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.

  12. 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.

  13. Age-Specific Characteristics of Serious Suicide Attempters in China

    ERIC Educational Resources Information Center

    Zhao, Pengcheng; Yang, Rong; Phillips, Michael R.

    2010-01-01

    Characteristics of four age groups of patients with medically serious suicide attempts from nine general hospitals in China (N = 617) were compared. There were no significant age-group differences by residence (rural vs. urban), method of attempt, proportion with prior attempts, or level of family functioning. Attempters [less than or equal to]20…

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

    PubMed

    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.

  15. 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

  16. [Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

    PubMed

    Vladimirova, I G; Kleĭmenov, S Iu; Alekseeva, T A; Radzinskaia, L I

    2003-01-01

    Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

  17. 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…

  18. ENVIRONMENTAL DEPENDENCE OF THE STAR FORMATION RATE AND THE SPECIFIC STAR FORMATION RATE AT FIXED MORPHOLOGY

    SciTech Connect

    Deng Xinfa

    2010-09-20

    From the Main galaxy sample of the Sloan Digital Sky Survey Data Release 7, I construct two volume-limited samples with luminosities -20.5 {<=} M{sub r} {<=} -18.5 and -22.5{<=}M{sub r} {<=}-20.5, respectively, to explore the environmental dependence of the star formation rate (SFR) and the specific star formation rate (SSFR) at fixed morphology. It is found that in these two volume-limited samples, galaxies in the lowest density regime preferentially have higher SFR and SSFR than galaxies in the densest regime. I divide each volume-limited Main galaxy sample into two distinct populations, the early type and the late type, and observe that the environmental dependence of the SFR and SSFR of galaxies remains true at fixed morphology: the SFR and SSFR of galaxies in the densest regime is still preferentially lower than that of the ones in the lowest density regime with the same morphological type. I also note that the environmental dependence of the SFR and SSFR of late-type galaxies is stronger than that of early-type galaxies.

  19. 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

  20. Rate of cognitive decline in relation to sex after 60 years-of-age: a systematic review.

    PubMed

    Ferreira, Leandro; Ferreira Santos-Galduróz, Ruth; Ferri, Cleusa Pinheiro; Fernandes Galduróz, José Carlos

    2014-01-01

    Some studies have shown differences in specific cognitive ability domains between the sexes at 60 years-of-age. However is important to analyze whether the rate of cognitive decline is also similar between the sexes after this age. The present study examined previously published literature to investigate whether cognitive decline is distinct between men and women after the age of 60 years. A systematic review was carried out with the PubMed, LILACS and PsycINFO databases (2001-2011) using the following search terms: aging, aged, cognitive function, mild cognitive impairment, mental health and cognition. We analyzed longitudinal research that used neuropsychological tests for evaluating cognitive function, showed results separated by sex and that excluded participants with dementia. Elderly women showed better performance in tests of episodic memory, whereas elderly men had a better visuospatial ability. Only one study detected distinct rates of cognitive decline in specific tests between the sexes. Despite differences observed in some domains, most of the studies showed that this rate is similar between the sexes until the age of 80 years. It is unclear whether sex influences the rate of cognitive decline after the age of 80 years. The present review observed that sex does not determine the rate of cognitive decline between 60 and 80 years-of-age. The contextual and cultural factors that involve men and women might determine a distinct decline between them, rather than sex alone.

  1. 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.

  2. 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.

  3. Age-specific incidence of neutralization antibodies of Herpes simplex virus.

    PubMed Central

    Terzin, A. L.; Masic, M. G.

    1976-01-01

    Sera of 1255 individuals from Novi Sad, varying in age from less than 1 month to 69 years, have been tested for neutralization antibodies to Herpes implex virus type 1. The eight newborns tested and 97% of the 507 adults were positive, with titres ranging from 1/4 to 1/256. The titres in newborns were significantly lower than the titres in adults. After birth the maternal antibodies declined rapidly and 94% of infants at the age of greater than 6 months and less than 2 years were negative. After the first year infants in Novi Sad start to acquire herpes-neutralizing antibodies actively, reaching a 50% incidence of positives between the 2nd and 3rd year of age. Age-specific incidence rates of herpes positives found in Novi Sad have been compared with those reported from Edinburgh, Freiburg i. Br. and Louisiana. Possible influences of several circumstances upon the incidence rate of positives detected by the neutralization test are discussed. PMID:185287

  4. Specific food structures supress appetite through reduced gastric emptying rate.

    PubMed

    Mackie, Alan R; Rafiee, Hameed; Malcolm, Paul; Salt, Louise; van Aken, George

    2013-06-01

    The aim of this study was to determine the extent to which gastric layering and retention of a meal could be used to reduce appetite using the same caloric load. Liquid (control) and semi-solid (active) meals were produced with the same protein, fat, carbohydrate, and mass. These were fed to 10 volunteers on separate days in a crossover study, and subjective appetite ratings, gastric contents, and plasma cholecystokinin (CCK) were assessed over a period of 3 h. The active meal showed food boluses in the stomach persisting for ~45 min, slower emptying rates, and lower plasma CCK levels over the first hour. After the first hour, both gastric emptying rates and plasma CCK levels were similar for both systems and slightly increased compared with the unfed situation. Despite the lower plasma CCK levels for the active meal over the first hour, this meal reduced appetite more than the control meal over the 3 h of the study. For a moderately increased plasma CCK level in the fed state, appetite was correlated with the volume of gastric contents rather than gastric emptying rates or plasma CCK. This suggests that enhanced gastric retention was the key factor in decreasing appetite and was probably mediated by a combination of intestinal nutrient sensing and increased viscosity in the stomach.

  5. Optimal Dynamic Advertising Strategy Under Age-Specific Market Segmentation

    NASA Astrophysics Data System (ADS)

    Krastev, Vladimir

    2011-12-01

    We consider the model proposed by Faggian and Grosset for determining the advertising efforts and goodwill in the long run of a company under age segmentation of consumers. Reducing this model to optimal control sub problems we find the optimal advertising strategy and goodwill.

  6. Effect of compost temperature on oxygen uptake rate, specific growth rate and enzymatic activity of microorganisms in dairy cattle manure.

    PubMed

    Miyatake, Fumihito; Iwabuchi, Kazunori

    2006-05-01

    Investigations were carried out to find out the relationship between temperature and microbial activity in dairy cattle manure composting using oxygen uptake rate, specific growth rate and enzymatic activities during autothermal and isothermal composting experiments. In autothermal composting, oxygen uptake rate and specific growth rate were found to be most intensive in order of 43 degrees C, 60 degrees C and 54 degrees C. Isothermal composting at 54 degrees C resulted highest levels of enzymatic activity and promoted the volatile solids reduction. Based on the maximum enzymatic activity, specific growth rate appeared to be more closely linked with microbial activity in compost than with oxygen uptake rate. The enhancement of specific growth rate, enzymatic activity and volatile solids reduction were induced at 54 degrees C in cattle manure composting.

  7. A stochastic version of the brass PF ratio adjustment of age-specific fertility schedules.

    PubMed

    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.

  8. 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.

  9. Age-specific seroprevalence of hepatitis A in Antananarivo (Madagascar)

    PubMed Central

    Raharimanga, Vaomalala; Carod, Jean-François; Ramarokoto, Charles-Emile; Chrétien, Jean-Baptiste; Rakotomanana, Fanjasoa; Talarmin, Antoine; Richard, Vincent

    2008-01-01

    Background Hepatitis A virus (HAV) is an enteric, viral, infectious disease endemic in many developing countries such as Madagascar. Infection is often subclinical or asymptomatic in children; however, symptomatic acute infections become more common with increasing age. In some developing countries, improvements in living conditions have led to changes in the epidemiological pattern of HAV infection. There are very few reports on the prevalence of HAV in Madagascar. This study was to determine the seroprevalence of hepatitis A virus antibodies in relation to age in the city of Antananarivo, Madagascar. Methods Serum samples collected in 2004 during a cross-sectional survey of individuals aged between two and 24 years from Antananarivo were tested for anti-HAV antibody using a commercial enzyme immunoassay kit. Subjects were investigated using a standardized social and medical history questionnaire. Results 926 subjects were enrolled including 406 males and 520 females. There were 251 children under 10 years old and 675 subjects between 10 and 24 years old. Of the 926 serum samples tested, 854 (92.2%) were positive for anti-HAV antibodies. The number of seropositive samples was similar for males and females. The overall seroprevalence was 83.7% (210/251) for children under 10 years old and 95.5% (644/675) for subjects aged between 10 and 24 years (p < 0.001). Conclusion Despite improvements in sanitary conditions and hygiene over the last few years, the prevalence of HAV in Antananarivo is high. Only children under five years old remain susceptible to HAV infection. Immunization against HAV is not needed at the present time in the Madagascan population, but should be recommended for travellers. PMID:18538023

  10. Tissue-specific accelerated aging in nucleotide excision repair deficiency

    PubMed Central

    Niedernhofer, Laura J.

    2008-01-01

    Nucleotide excision repair (NER) is a multi-step DNA repair mechanism that removes helix-distorting modified nucleotides from the genome. NER is divided into two subpathways depending on the location of DNA damage in the genome and how it is first detected. Global genome NER identifies and repairs DNA lesions throughout the genome. This subpathway of NER primarily protects against the accumulation of mutations in the genome. Transcription-coupled (TC) NER rapidly repairs lesions in the transcribed strand of DNA that block transcription by RNA polymerase II. TC-NER prevents cell death in response to stalled transcription. Defects in NER cause three distinct human diseases: xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy. Each of these syndromes is characterized by premature onset of pathologies that overlap with those associated with old age in humans. This reveals the contribution of DNA damage to multiple age-related diseases. Tissues affected include the skin, eye, bone marrow, nervous system and endocrine axis. This review emphasizes accelerated aging associated with xeroderma pigmentosum and discusses the cause of these pathologies, either mutation accumulation or cell death as a consequence of failure to repair DNA damage. PMID:18538374

  11. Specific heat flow rate: an on-line monitor and potential control variable of specific metabolic rate in animal cell culture that combines microcalorimetry with dielectric spectroscopy.

    PubMed

    Guan, Y; Evans, P M; Kemp, R B

    1998-06-05

    One of the requirements for enhanced productivity by the animal culture systems used in biotechnology is the direct assessment of the metabolic rate by on-line biosensors. Based on the fact that cell growth is associated with an enthalpy change, it is shown that the specific heat flow rate is stoichiometrically related to the net specific rates of substrates, products, and indeed to specific growth rate, and therefore a direct reflection of metabolic rate. Heat flow rate measured by conduction calorimetry has a technical advantage over estimates for many material flows which require assays at a minimum of two discrete times to give the rate. In order to make heat flow rate specific to the amount of the living cellular system, it would be advantageous to divide it by viable biomass. This requirement has been fulfilled by combining a continuous flow microcalorimeter ex situ with a dielectric spectroscope in situ, the latter measuring the viable cell mass volume fraction. The quality of the resulting biosensor for specific heat flow rate was illustrated using batch cultures of Chinese hamster ovary cells (CHO 320) producing recombinant human interferon-gamma (IFN-gamma) during growth in a stirred tank bioreactor under fully aerobic conditions. The measuring scatter of the probe was decreased significantly by applying the moving average technique to the two participant signals. It was demonstrated that the total metabolic rate of the cells, as indicated by the specific heat flow rate sensor, decreased with increasing time in batch culture, coincident with the decline in the two major substrates, glucose and glutamine, and the accumulation of the by-products, ammonia and lactate. Furthermore, the specific heat flow rate was an earlier indicator of substrate depletion than the flow rate alone. The calorimetric-respirometric ratio showed the intensive participation of anaerobic processes during growth and the related IFN-gamma production. Specific heat flow rate was

  12. Short-Term Heart Rate Variability—Influence of Gender and Age in Healthy Subjects

    PubMed Central

    Voss, Andreas; Schroeder, Rico; Heitmann, Andreas; Peters, Annette; Perz, Siegfried

    2015-01-01

    In the recent years, short-term heart rate variability (HRV) describing complex variations of beat-to-beat interval series that are mainly controlled by the autonomic nervous system (ANS) has been increasingly analyzed to assess the ANS activity in different diseases and under various conditions. In contrast to long-term HRV analysis, short-term investigations (<30 min) provide a test result almost immediately. Thus, short-term HRV analysis is suitable for ambulatory care, patient monitoring and all those applications where the result is urgently needed. In a previous study, we could show significant variations of 5-min HRV indices according to age in almost all domains (linear and nonlinear) in 1906 healthy subjects from the KORA S4 cohort. Based on the same group of subjects, general gender-related influences on HRV indices are to be determined in this study. Short-term 5-min HRV indices from linear time and frequency domain and from nonlinear methods (compression entropy, detrended fluctuation analysis, traditional and segmented Poincaré plot analysis, irreversibility analysis, symbolic dynamics, correlation and mutual information analysis) were determined from 782 females and 1124 males. First, we examined the gender differences in two age clusters (25–49 years and 50–74 years). Secondly, we investigated the gender-specific development of HRV indices in five age decade categories, namely for ages 25–34, 35–44, 45–54, 55–64 and 65–74 years. In this study, significant modifications of the indices according to gender could be obtained, especially in the frequency domain and correlation analyses. Furthermore, there were significant modifications according to age in nearly all of the domains. The gender differences disappeared within the last two age decades and the age dependencies disappeared in the last decade. To summarize gender and age influences need to be considered when performing HRV studies even if these influences only partly differ. PMID

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. 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…

  18. 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…

  19. 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.

  20. 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.

  1. 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

  2. Prediction of adult Sheldon somatotypes I and II from ratings and measurements at childhood ages.

    PubMed

    Walker, R N; Tanner, J M

    1980-01-01

    The photographs of 82 boys from the Harpenden Growth Study were assigned somatotype ratings at ages 5, 8, 11, 14, and 18 years, using both Sheldon's earlier, anthroposcopic method and his revised, objective method (somatotype II). Inter-judge correlations for the anthroposcopic ratings of the 18-year-olds ranged from 0.79 to 0.93 for the three components; correlations for the somatotype II ratings ranged from 0.94 to 0.99. The three components of the somatotype II ratings showed greater independence of one another than did those of the anthroposcopic method, which tended to collapse towards two dimensions. Correlations for corresponding components between the anthroposcopic and somatotype II ratings at the same age were mostly in the low 0.80s. Mean somatotype ratings changed little with age in either method, but the somatotype II ratings were consistently higher in endomorphy and mesomorphy and lower in ectomorphy than the anthroposcopic ratings. Patterns of inter-age correlations were similar within methods: endomorphy showed lower age-to-age correlations than did mesomorphy and ectomorphy. Correlations of anthroposcopic component ratings with ratings at age 18 increased distinctly from age 5 to age 8, less sharply thereafter. Between ages 8 and 18, within observer, they were 0.72, 0.83, and 0.82, for endomorphy, mesomorphy, and ectomorphy. These 8-to-18 correlations for mesomorphy and ectomorphy are similar in magnitude to those for height.

  3. 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…

  4. Spatial protein quality control and the evolution of lineage-specific ageing

    PubMed Central

    Nyström, Thomas

    2011-01-01

    Propagation of a species requires periodic cell renewal to avoid clonal extinction. Sexual reproduction and the separation of germ cells from the soma provide a mechanism for such renewal, but are accompanied by an apparently mandatory ageing of the soma. Data obtained during the last decade suggest that a division of labour exists also between cells of vegetatively reproducing unicellular organisms, leading to the establishment of a soma-like and germ-like lineage with distinct fitness and longevity characteristics. This division of labour in both bacteria and yeast entails segregation of damaged and aggregated proteins such that the germ-like lineage is kept free of damage to the detriment of the soma-like lineage. In yeast, this spatial protein quality control (SQC) encompasses a CCT-chaperonin-dependent translocation and merging of cytotoxic protein aggregates. This process is regulated by Sir2, a protein deacetylase that modulates the rate of ageing in organisms ranging from yeast to worms and flies. Recent data also demonstrate that SQC is intimately integrated with the machinery establishing proper cell polarity and that this machinery is required for generating a soma-like and germ-like lineage in yeast. Deciphering the details of the SQC network may increase our understanding of the development of age-related protein folding disorders and shed light on the selective forces that paved the way for polarity and lineage-specific ageing to evolve. PMID:21115532

  5. Task factor usability ratings for different age groups writing Chinese.

    PubMed

    Chan, A H S; So, J C Y

    2009-11-01

    This study evaluated how different task factors affect performance and user subjective preferences for three different age groups of Chinese subjects (6-11, 20-23, 65-70 years) when hand writing Chinese characters. The subjects copied Chinese character sentences with different settings for the task factors of writing plane angle (horizontal 0 degrees , slanted 15 degrees ), writing direction (horizontal, vertical), and line spacing (5 mm, 7 mm and no lines). Writing speed was measured and subjective preferences (effectiveness and satisfaction) were assessed for each of the task factor settings. The result showed that there was a conflict between writing speed and personal preference for the line spacing factor; 5 mm line spacing increased writing speed but it was the least preferred. It was also found that: vertical and horizontal writing directions and a slanted work surface suited school-aged children; a horizontal work surface and horizontal writing direction suited university students; and a horizontal writing direction with either a horizontal or slanted work surface suited the older adults.

  6. 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

  7. 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.

  8. Penetration rates over 30 years in the space age

    NASA Astrophysics Data System (ADS)

    McDonnell, J. A. M.; Baron, J. M.

    1995-02-01

    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. 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.

  10. 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

  11. The effect of sampling on estimates of lexical specificity and error rates.

    PubMed

    Rowland, Caroline F; Fletcher, Sarah L

    2006-11-01

    Studies based on naturalistic data are a core tool in the field of language acquisition research and have provided thorough descriptions of children's speech. However, these descriptions are inevitably confounded by differences in the relative frequency with which children use words and language structures. The purpose of the present work was to investigate the impact of sampling constraints on estimates of the productivity of children's utterances, and on the validity of error rates. Comparisons were made between five different sized samples of wh-question data produced by one child aged 2;8. First, we assessed whether sampling constraints undermined the claim (e.g. Tomasello, 2000) that the restricted nature of early child speech reflects a lack of adultlike grammatical knowledge. We demonstrated that small samples were equally likely to under- as overestimate lexical specificity in children's speech, and that the reliability of estimates varies according to sample size. We argued that reliable analyses require a comparison with a control sample, such as that from an adult speaker. Second, we investigated the validity of estimates of error rates based on small samples. The results showed that overall error rates underestimate the incidence of error in some rarely produced parts of the system and that analyses on small samples were likely to substantially over- or underestimate error rates in infrequently produced constructions. We concluded that caution must be used when basing arguments about the scope and nature of errors in children's early multi-word productions on analyses of samples of spontaneous speech.

  12. 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

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

    PubMed

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

    2015-08-06

    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.

  14. "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…

  15. 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…

  16. Improved Estimates of Cancer-Specific Survival Rates From Population-Based Data

    PubMed Central

    Ries, Lynn A. G.; Mariotto, Angela B.; Reichman, Marsha E.; Ruhl, Jennifer; Cronin, Kathleen A.

    2010-01-01

    Background Accurate estimates of cancer survival are important for assessing optimal patient care and prognosis. Evaluation of these estimates via relative survival (a ratio of observed and expected survival rates) requires a population life table that is matched to the cancer population by age, sex, race and/or ethnicity, socioeconomic status, and ideally risk factors for the cancer under examination. Because life tables for all subgroups in a study may be unavailable, we investigated whether cause-specific survival could be used as an alternative for relative survival. Methods We used data from the Surveillance, Epidemiology, and End Results Program for 2 330 905 cancer patients from January 1, 1992, through December 31, 2004. We defined cancer-specific deaths according to the following variables: cause of death, only one tumor or the first of multiple tumors, site of the original cancer diagnosis, and comorbidities. Estimates of relative survival and cause-specific survival that were derived by use of an actuarial method were compared. Results Among breast cancer patients who were white, black, or of Asian or Pacific Islander descent and who were older than 65 years, estimates of 5-year relative survival (107.5%, 106.6%, and 103.0%, respectively) were higher than estimates of 5-year cause-specific survival (98.6%, 95% confidence interval [CI] = 98.4% to 98.8%; 97.4%, 95% CI = 96.2% to 98.2%; and 99.2%, 95% CI = 98.4%, 99.6%, respectively). Relative survival methods likely underestimated rates for cancers of the oral cavity and pharynx (eg, for white cancer patients aged ≥65 years, relative survival = 54.2%, 95% CI = 53.1% to 55.3%, and cause-specific survival = 60.1%, 95% CI = 59.1% to 60.9%) and the lung and bronchus (eg, for black cancer patients aged ≥65 years, relative survival = 10.5%, 95% CI = 9.9% to 11.2%, and cause-specific survival = 11.9%, 95% CI = 11.2 % to 12.6%), largely because of mismatches between the population with these diseases and

  17. 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

  18. 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

  19. 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.

  20. 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…

  1. 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…

  2. 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…

  3. Ratings of managerial skill requirements: comparison of age- and job-related factors.

    PubMed

    Avolio, B J; Waldman, D A

    1989-12-01

    This article examines how individual characteristics (age, experience) and organizational characteristics (department, level) influence the skill requirements rated as being important for managerial jobs. One hundred ninety-seven managerial employees completed a survey composed of 20 skill dimensions pertinent to supervisory positions in the mining industry. Organizational level and departmental affiliation were correlated with job skill importance ratings. Ratings of skill importance were also correlated with the age of the person being rated, years of experience, and the age of the rater. As predicted, correlations with ratee age varied across different skill dimensions. This study has implications for fair employment practices to the degree that raters base evaluations of a job on the age of incumbents vs. job relevant characteristics.

  4. 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

  5. Effect of temperature on the rate of ageing: an experimental study of the blowfly Calliphora stygia.

    PubMed

    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.

  6. Tuberculosis in ageing: high rates, complex diagnosis and poor clinical outcomes

    PubMed Central

    Cruz-Hervert, Luis Pablo; García-García, Lourdes; Ferreyra-Reyes, Leticia; Bobadilla-del-Valle, Miriam; Cano-Arellano, Bulmaro; Canizales-Quintero, Sergio; Ferreira-Guerrero, Elizabeth; Báez-Saldaña, Renata; Téllez-Vázquez, Norma; Nava-Mercado, Ariadna; Juárez-Sandino, Luis; Delgado-Sánchez, Guadalupe; Fuentes-Leyra, César Alejandro; Montero-Campos, Rogelio; Martínez-Gamboa, Rosa Areli; Small, Peter M.; Sifuentes-Osornio, José; Ponce-de-León, Alfredo

    2012-01-01

    Background: worldwide, the frequency of tuberculosis among older people almost triples that observed among young adults. Objective: to describe clinical and epidemiological consequences of pulmonary tuberculosis among older people. Methods: we screened persons with a cough lasting more than 2 weeks in Southern Mexico from March 1995 to February 2007. We collected clinical and mycobacteriological information (isolation, identification, drug-susceptibility testing and IS6110-based genotyping and spoligotyping) from individuals with bacteriologically confirmed pulmonary tuberculosis. Patients were treated in accordance with official norms and followed to ascertain treatment outcomes, retreatment, and vital status. Results: eight hundred ninety-three tuberculosis patients were older than 15 years of age; of these, 147 (16.5%) were 65 years of age or older. Individuals ≥65 years had significantly higher rates of recently transmitted and reactivated tuberculosis. Older age was associated with treatment failure (OR = 5.37; 95% CI: 1.06–27.23; P = 0.042), and death due to tuberculosis (HR = 3.52; 95% CI: 1.78–6.96; P < 0.001) adjusting for sociodemographic and clinical variables. Conclusions: community-dwelling older individuals participate in chains of transmission indicating that tuberculosis is not solely due to the reactivation of latent disease. Untimely and difficult diagnosis and a higher risk of poor outcomes even after treatment completion emphasise the need for specific strategies for this vulnerable group. PMID:22431155

  7. 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.

  8. 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

  9. Trends in age-adjusted coronary heart disease mortality rates in Slovakia between 1993 and 2009.

    PubMed

    Psota, Marek; Pekarciková, Jarmila; O'Mullane, Monica; Rusnák, Martin

    2013-06-01

    Cardiovascular diseases (CVD) and especially coronary heart disease (CHD) are the main causes of death in the Slovak Republic (SR). The aim of this study is to explore trends in age-adjusted coronary heart disease mortality rates in the whole Slovak population and in the population of working age between the years 1993 and 2009. A related indicator - potential years of life lost (PYLL) due to CHD--was calculated in the same period for males and females. Crude CHD mortality rates were age-adjusted using European standard population. The joinpoint Poisson regression was performed in order to find out the annual percentage change in trends. The age-adjusted CHD mortality rates decreased in the Slovak population and also in the population of working age. The change was significant only within the working-age sub-group. We found that partial diagnoses (myocardial infarction and chronic ischaemic heart disease) developed in the mirror-like manner. PYLL per 100,000 decreased during the observed period and the decline was more prominent in males. For further research we recommend to focus on several other issues, namely, to examine the validity of cause of death codes, to examine the development of mortality rates in selected age groups, to find out the cause of differential development of mortality rates in the Slovak Republic in comparison with the Czech Republic and Poland, and to explain the causes of decrease of the age-adjusted CHD mortality rates in younger age groups in Slovakia.

  10. Reliable Ratings or Reading Tea Leaves: Can Parent, Teacher, and Clinician Behavioral Ratings of Preschoolers Predict ADHD at Age Six?

    PubMed Central

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

    2013-01-01

    Objective 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. Method Hyperactive/inattentive preschoolers [N=104, 75% boys, Mean (SD) age = 4.37 (.47) years] were followed over two 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 (.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. Results 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. Conclusion 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. PMID:24085388

  11. Rated age-of-acquisition norms for over 3,200 German words.

    PubMed

    Birchenough, Julia M H; Davies, Robert; Connelly, Vincent

    2016-03-04

    Words that have been learned early in life are responded to faster than words that have been acquired later. Subjective ratings of acquisition ages have been successfully employed to study the effect of age of acquisition (AoA). Although a large number of norms exist in many languages, fewer are available for German. Therefore, subjective AoA ratings for 3,259 German words were collected online, including 2,363 nouns and 473 verbs. These words were presented in lists of 140 words, and participants rated the age in years at which they had first learned each word. A split-half correlation testified to a high internal reliability. There were also high correlations with rated AoA values for subsets of the items that had been collected in previous studies, in both German and English. Age and gender were found to influence the ratings very weakly, in that older and male participants tended to give slightly higher age ratings. Education, multilingualism, and frequent usage of languages other than German did not exert an influence on the rating values. These new ratings will extend the currently existing norms available for language and reading research across languages and will provide researchers with a wider choice of word stimuli. The ratings are available expressed in two measurements: age in years, and AoA rated on a 7-point Likert scale.

  12. Heart rate responses of women aged 23–67 years during competitive orienteering

    PubMed Central

    Bird, S; George, M; Balmer, J; Davison, R

    2003-01-01

    Objectives: To compare the heart rate responses of women orienteers of different standards and to assess any relation between heart rate responses and age. Methods: Eighteen competitive women orienteers completed the study. They were divided into two groups: eight national standard orienteers (ages 23–67 years); 10 club standard orienteers (ages 24–67 years). Each participant had her heart rate monitored during a race recognised by the British Orienteering Federation. Peak heart rate (HRPEAK), mean heart rate (HRMEAN), standard deviation of her heart rate during each orienteering race (HRSD), and mean change in heart rate at each control point (ΔHRCONTROL) were identified. The data were analysed using analysis of covariance with age as a covariate. Results: National standard orienteers displayed a lower within orienteering race standard deviation in heart rate (6 (2) v 12 (2) beats/min, p<0.001) and a lower ΔHRCONTROL (5 (1) v 17 (4) beats/min, p<0.001). The mean heart rate during competition was higher in the national standard group (170 (11) v 158 (11) beats/min, p = 0.025). The HRMEAN for the national and club standard groups were 99 (8)% and 88 (9)% of their age predicted maximum heart rate (220-age) respectively. All orienteers aged >55 years (n = 4) recorded HRMEAN greater than their age predicted maximum. Conclusions: The heart rate responses indicate that national and club standard women orienteers of all ages participate in the sport at a vigorous intensity. The higher ΔHRCONTROL of club standard orienteers is probably due to failing to plan ahead before arriving at the controls and this, coupled with slowing down to navigate or relocate when lost, produced a higher HRSD. PMID:12782552

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

    USGS Publications Warehouse

    Bodkin, James L.; Mulcahy, Daniel M.; Lensink, Calvin J.

    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 oil 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 were similiar to those reported in the literature based on in situ observations of marked individuals.

  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. Biomarkers of aging in women and the rate of longitudinal changes.

    PubMed

    Ueno, Linda Massako; Yamashita, Yoshinori; Moritani, Toshio; Nakamura, Eitaro

    2003-01-01

    The purposes of this study were (1) to estimate biological age score (BAS) in Japanese healthy women based on the 4-7 years longitudinal data for physiological, hematological and biochemical examinations and (2) to examine the rate of aging changes in adult women based on the estimated BAS. The samples consisted of cross-sectional (n=981) and longitudinal (n=110) groups. Out of 31 variables examined, five variables (forced expiratory volume in 1.0 s, systolic blood pressure, mean corpuscular hemoglobin, glucose, albumin/globulin ratio) that met the following criteria: 1) significant cross-sectional correlation with age; 2) significant longitudinal change in the same direction as the cross-sectional correlation; and (3) assessment of redundancy, were selected as candidate biomarkers of aging. This variable set was then submitted into a principal component analysis, and the first principal component obtained from this analysis was used as an equation for assessing one's BAS. Individual BAS showed a high longitudinal stability of age-related changes, suggesting high predictive validity of our newly developed aging measurement equation. However, changes in the aging rate based on the estimated BAS were not constant. The mean slopes of the regression lines of BAS for the three age groups (age<45, 45age<65 yrs, 65age) were 0.095, 0.065, 0.138, respectively. One-way analysis of variance detected a significant difference (F=5.14, p<0.01) among the three age groups. These results suggest that the rate of aging in adult women is relatively slower until 65 years of age, but after 65, the rate of aging shows a rapid increase. We concluded that the longitudinal method used for selection of variables to compute the BAS was useful and theoretically valid compared to those obtained from cross-sectional data analysis.

  16. 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.

  17. 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.

  18. The Gifted Rating Scales-School Form: A Validation Study Based on Age, Gender, and Race

    ERIC Educational Resources Information Center

    Pfeiffer, Steven; Petscher, Yaacov; Kumtepe, Alper

    2008-01-01

    This study examined the internal consistency and validity of a new rating scale to identify gifted students, the Gifted Rating Scales-School Form (GRS-S). The study explored the effect of gender, race/ethnicity, age, and rater familiarity on GRS-S ratings. One hundred twenty-two students in first to eighth grade from elementary and middle schools…

  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. [The characteristics of aging rate among elderly people on the European North of Russia].

    PubMed

    Golubeva, E Iu; Danilova, R I

    2012-01-01

    Social factors and the role of environment which influence to the aging process on the cohort of the elderly people on European North of Russia have been discussed. The indicators of aging of elderly people stated in the different living conditions with defining risk factors have been analyzed. The predominance of the individuals with high rates of aging in the men's cohort living in the rural areas has been considered. Consume alcohol is the aggravating factor accelerating the significant aging rate of women addicted to alcohol.

  1. Gender and age-specific seroprevalence of human papillomavirus 16 and 18 in general population in Tehran, Iran.

    PubMed

    Aghakhani, Arezoo; Mamishi, Setareh; Sabeti, Shahram; Bidari-Zerehpoosh, Farahnaz; Banifazl, Mohammad; Bavand, Anahita; Ramezani, Amitis

    2017-04-01

    The assessment of the gender and age-specific seroprevalence of human papillomavirus (HPV) is essential for planning of HPV vaccine implementation into the preventive programs. In this study, we aimed to determine the age-specific seroprevalence of HPV-16 and 18 in both males and females in Tehran, Iran. Three hundred and seventy-eight women (10-35 years) and 162 men (10-25 years) from Tehran, Iran, were enrolled. Anti-HPV IgG antibodies against HPV-16 and HPV-18 were detected by ELISA using papillomavirus type 16 and 18 L1-capsids as antigen. HPV-16 antibody was detected in 15.6 and 13.6% of women and men, respectively. Antibody against HPV-18 was found positive in 12.7 and 8% of women and men, respectively. The highest seroprevalence of HPV-16 and 18 were seen in women aged 26-30 years (22.2 and 19.4%, respectively), and the lowest HPV-16 and 18 seropositivity rates were seen in males and females aged 10-15 years (9.3 and 1.9%, respectively). In our cohort of study, in males, both anti-HPV-16 and 18 increased after age 15 years, peaking in men aged 21-25 years. In women, both HPV-16 and 18 seropositivity increased after 15 years, declined at 21-25 years, peaked in women aged 26-30 years and again decreased after 30 years. Our data showed increasing exposure rate to high-risk HPV vaccine types in our studied population over 15 years of age. In order to prevent the HPV-related cancers, implementation of HPV vaccine into the national immunization program in Iran and vaccination of females and males less than 15 years of age are suggested.

  2. 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.

  3. 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.

  4. Approach for an improved experimental evaluation of the specific absorption rate in magnetic fluid hyperthermia

    NASA Astrophysics Data System (ADS)

    Iacob, N.; Schinteie, G.; Palade, P.; Kuncser, V.

    2015-04-01

    A new methodology for the accurate determination of the specific absorption rate of ferrofluids with magnetite nanoparticles of average size of about 10 nm subjected to alternative current magnetic fields is proposed. A simple numerical compensation of the heating rates by the cooling rates obtained at similar temperatures is employed. Comparisons of the as-obtained adiabatic heating curves with theoretical evaluations are discussed.

  5. Age- and Brain Region-Specific Differences in Mitochondrial Bioenergetics in Brown Norway Rats

    EPA Pesticide Factsheets

    Differences in various mitochondrial bioenergetics parameters in different brain regions in different age groups.This dataset is associated with the following publication:Pandya, J.D., J. Royland , R.C. McPhail, P.G. Sullivan, and P. Kodavanti. Age-and Brain Region-Specific Differences in Mitochondrial Bioenergetics in Brown Norway Rats. NEUROBIOLOGY OF AGING. Elsevier Science Ltd, New York, NY, USA, 42: 25-34, (2016).

  6. Mortality rates for chronic lower respiratory diseases in Italy from 1979 to 2010: an age-period-cohort analysis.

    PubMed

    Pesce, Giancarlo

    2016-01-01

    Chronic lower respiratory diseases (CLRDs) are a major cause of morbidity and mortality worldwide. The objectives of this study were to estimate the trends in CLRD mortality in Italy, and the specific contributions of age, time period and birth cohort in driving these trends. Population and cause-of-death data in Italy between 1979 and 2010 were collected from the World Health Organization website. Age-specific mortality rates for CLRDs, and effects for age, time period and birth cohort on mortality trends were estimated using age-period-cohort models. Chronic obstructive pulmonary disease (COPD) and chronic bronchitis represent nearly 98% of the deaths from CLRDs. Despite the overall number of deaths have been stable (in men) or increasing (in women), the age-standardised rates have been steadily decreasing from 1979 to 2010, passing from 104.3 to 55.4 per 100 000 person-years in men and from 32.2 to 19.6 per 100 000 person-years in women. The average relative annual decrease was -3.6% in men and -2.7% in women. Since the end of the 1990s, the decreasing trend of CLRD mortality has started to level off, in particular in women. The decrease in CLRD mortality rates has been more accentuated in more recent cohorts and in younger age groups. Both birth cohort and time period significantly affected the CLRD mortality rates, suggesting that changes in the spread of risk factors (smoking habits, early-life and occupational exposures) across different birth cohorts, as well as in advanced in healthcare and medical practice, may have played a major role in secular changes in COPD mortality rates in Italy.

  7. 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.

  8. Parental Age Affects Somatic Mutation Rates in the Progeny of Flowering Plants1

    PubMed Central

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

    2015-01-01

    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

  9. 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.

  10. “IDEAL” Aging is Associated with Lower Resting Metabolic Rate: The Baltimore Longitudinal Study of Aging

    PubMed Central

    Schrack, Jennifer A.; Knuth, Nicolas D.; Simonsick, Eleanor M.; Ferrucci, Luigi

    2014-01-01

    Objectives To assess the associations among age, health status, and resting metabolic rate (RMR) in a large population of older adults. Design Cross-Sectional Analysis Setting Community-dwelling volunteers from the Baltimore Longitudinal Study of Aging (BLSA) Participants Four hundred twenty persons aged 40 – 96 (mean 68.2 ± 11.0) who underwent a comprehensive physical examination, cognitive assessment, resting metabolic rate testing, body composition assessment, and physical function testing during a three-day clinic visit. Measurements Participants were assigned to “IDEAL” (Insight into the Determination of Exceptional Aging and Longevity) or “non-IDEAL” categories based on health status. IDEAL participants were defined by the absence of: physical and cognitive impairments, chronic conditions/comorbidities and blood profile alterations. A three-stage linear regression model was used to assess the relationship between RMR and age, using IDEAL classification as a predictor, adjusting for sex and body composition. Results RMR averaged 1512.4 (± 442.9) kcal/day and was lower with advancing age (β = −8.55, p < 0.001). After adjusting for age, sex, and body composition RMR was 109.6 kcals/day lower in IDEAL than non-IDEAL participants (p < 0.005). Conclusions Individuals who are fully functional and free of major medical conditions have lower RMR than those affected by disease and functional impairments. These findings suggest that health status plays a role in energy utilization and regulation independent of age and body composition and that elevated RMR may be a global biomarker of poor health in older persons. PMID:24635835

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

    PubMed Central

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

    2017-01-01

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

  12. 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.

  13. 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.

  14. Site-Specific Characteristics of Bone Marrow Mesenchymal Stromal Cells Modify the Effect of Aging on the Skeleton.

    PubMed

    Wang, Xing; Zou, Xuan; Zhao, Jing; Wu, Xia; E, Lingling; Feng, Lin; Wang, Dongsheng; Zhang, Guilan; Xing, Helin; Liu, Hongchen

    2016-03-15

    Bone is a self-renewing tissue. Bone marrow mesenchymal stromal cells (BMSCs) are located in the adult skeleton and are believed to be involved in the maintenance of skeletal homeostasis throughout life. With increasing age, the ability of the skeleton to repair itself decreases, possibly due to the reduced functional capacity of BMSCs. Recent evidence has suggested the existence of at least two populations of BMSCs with different embryonic origins that cannot be interchanged during stem cell recruitment: craniofacial BMSCs (neural crest origin) and appendicular BMSCs (mesoderm origin). Questions arise as to whether the site-specific characteristics alter the effect of aging on the skeleton. In this study, the effects of biological aging on human BMSCs were compared with BMSCs derived from the craniofacial bone versus those derived from the appendicular skeleton. The phenotype, proliferation, and functional characteristics (osteogenic differentiation, cytokine secretion, and bone formation in vivo) of the BMSCs were investigated. The results demonstrated that the proliferative capacity and osteogenic differentiation of the BMSCs decrease significantly with age both in vitro and in vivo. For age-matched groups, the osteogenic differentiation capacity of alveolar BMSCs was higher than that of femoral BMSCs in the middle-aged and old groups, while there was no significant difference for the young groups. Compared with old alveolar BMSCs, old femoral BMSCs had a significantly longer population doubling time, a smaller colony-forming population, and less bone formation in vivo, while there was no significant difference for the young and middle-aged groups. Distinct differences in the expression of cytokine factors were also found. In conclusion, human BMSCs display an age-related decrease in functional capacity, and embryonic origins may play a critical role in mediating the aging rate of BMSCs. These data provide novel insights into the skeletal site-specific

  15. The heritability of level and rate-of-change in cognitive functioning in Danish twins aged 70 years and older.

    PubMed

    McGue, Matt; Christensen, Kaare

    2002-01-01

    To investigate heritable influences on overall level and rate-of-change in cognitive ability, biometric growth models were fit to cognitive data from nearly 1000 Danish twins age 70 years and older. Twins are participants in the ongoing Longitudinal Study of Aging Danish Twins, a cohort-sequential study of twins assessed every 2 years for up to four waves. Cognitive ability was assessed by five brief cognitive tasks: a fluency measure, forward and backward digit span, and immediate and delayed list recall. Model-fitting results indicated that although the overall level of cognitive functioning was highly heritable (h(2) = .76, 95% confidence interval of .68 to .82), the rate of linear change was not (h(2) = .06, 95% confidence interval of .00 to .57). These findings suggest that the search for specific genes might reasonably focus on average level of cognitive performance, whereas specific environmental influences might account for cognitive change.

  16. Age of Entrance Into the First Grade as Related to Rate of Scholastic Achievement.

    ERIC Educational Resources Information Center

    Ilika, Joseph

    The influence of age of entrance to first grade on subsequent rate of scholastic development was tested in this longitudinal investigation. Forty-one pairs of boys and forty-nine pairs of girls, matched according to sex, intelligence, and socioeconomic status, were subjects. The mean chronological age of late entrants was 81 months, opposed to 72…

  17. 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.

  18. The Mitochondrial Lon Protease Is Required for Age-Specific and Sex-Specific Adaptation to Oxidative Stress.

    PubMed

    Pomatto, Laura C D; Carney, Caroline; Shen, Brenda; Wong, Sarah; Halaszynski, Kelly; Salomon, Matthew P; Davies, Kelvin J A; Tower, John

    2017-01-09

    Multiple human diseases involving chronic oxidative stress show a significant sex bias, including neurodegenerative diseases, cancer, immune dysfunction, diabetes, and cardiovascular disease. However, a possible molecular mechanism for the sex bias in physiological adaptation to oxidative stress remains unclear. Here, we report that Drosophila melanogaster females but not males adapt to hydrogen peroxide stress, whereas males but not females adapt to paraquat (superoxide) stress. Stress adaptation in each sex requires the conserved mitochondrial Lon protease and is associated with sex-specific expression of Lon protein isoforms and proteolytic activity. Adaptation to oxidative stress is lost with age in both sexes. Transgenic expression of transformer gene during development transforms chromosomal males into pseudo-females and confers the female-specific pattern of Lon isoform expression, Lon proteolytic activity induction, and H2O2 stress adaptation; these effects were also observed using adult-specific transformation. Conversely, knockdown of transformer in chromosomal females eliminates the female-specific Lon isoform expression, Lon proteolytic activity induction, and H2O2 stress adaptation and produces the male-specific paraquat (superoxide) stress adaptation. Sex-specific expression of alternative Lon isoforms was also observed in mouse tissues. The results develop Drosophila melanogaster as a model for sex-specific stress adaptation regulated by the Lon protease, with potential implications for understanding sexual dimorphism in human disease.

  19. Aging and memory for numerical information: the role of specificity and expertise in associative memory.

    PubMed

    Castel, Alan D

    2007-05-01

    In order to examine the nature of associative memory deficits in old age, the present study examined how younger and older adults link numerical and object information to other items. The hypothesis was that there would be large age differences for numerical information caused by the arbitrariness and specificity of this type of information, but that this could be reduced by expertise. Participants studied sentences that contained numeric quantity, object, and location information (e.g., 26 cherries in the bowl); they were later cued with the location and had to recall the object and quantity. In general, there were significant age differences for quantity recall but negligible age differences for recall of related objects but not unrelated objects. However, a group of older retired accountants and bookkeepers showed exceptional memory for quantity information. The findings suggest that the associative deficit in old age is based on the linking of specific arbitrary information.

  20. [Age- and sex-specific features of new-onset pulmonary tuberculosis in the Krasnoyarsk Territory].

    PubMed

    Koretskaia, N M

    2007-01-01

    A total of 1150 cases of new-onset pulmonary tuberculosis were analyzed. A higher liability to the disease was shown in young females and males of ripe age. There was evidence for that the severer pattern of clinical forms and the nature of the process were directly proportional to the age of patients. Age-specific differences were found in the ways of detecting the disease and in the regularity of control fluorographic studies. The inclusion of persons aged 60 years or older into an increased risk group was justified. A severer pattern of clinical forms and characteristics of the process were established in males, which are largely caused by that the latter had irregularly underwent control fluorographic studies. Age- and gender-specific features of tuberculosis, which are typical of this region, have been identified.

  1. Age specific differences in efficacy and safety for the CYD-tetravalent dengue vaccine.

    PubMed

    Wilder-Smith, Annelies; Massad, Eduardo

    2016-01-01

    CYD-TDV is the first dengue vaccine to have completed Phase 3 efficacy trials. Efficacy was consistently higher in those aged 9 and above for all variables studied: efficacy against virologically confirmed dengue of any severity and serotype, serotype specific efficacy, efficacy dependent on baseline seropositivity, efficacy against hospitalizations and efficacy against severe disease. Because of the higher efficacy and the absence of a safety signal, the age group with the best benefit of the use of CYD-TDV is individuals aged 9 and above - the age group for which licensure is now being sought.

  2. Vocal Age Disguise: The Role of Fundamental Frequency and Speech Rate and Its Perceived Effects

    PubMed Central

    Skoog Waller, Sara; Eriksson, Mårten

    2016-01-01

    The relationship between vocal characteristics and perceived age is of interest in various contexts, as is the possibility to affect age perception through vocal manipulation. A few examples of such situations are when age is staged by actors, when ear witnesses make age assessments based on vocal cues only or when offenders (e.g., online groomers) disguise their voice to appear younger or older. This paper investigates how speakers spontaneously manipulate two age related vocal characteristics (f0 and speech rate) in attempt to sound younger versus older than their true age, and if the manipulations correspond to actual age related changes in f0 and speech rate (Study 1). Further aims of the paper is to determine how successful vocal age disguise is by asking listeners to estimate the age of generated speech samples (Study 2) and to examine whether or not listeners use f0 and speech rate as cues to perceived age. In Study 1, participants from three age groups (20–25, 40–45, and 60–65 years) agreed to read a short text under three voice conditions. There were 12 speakers in each age group (six women and six men). They used their natural voice in one condition, attempted to sound 20 years younger in another and 20 years older in a third condition. In Study 2, 60 participants (listeners) listened to speech samples from the three voice conditions in Study 1 and estimated the speakers’ age. Each listener was exposed to all three voice conditions. The results from Study 1 indicated that the speakers increased fundamental frequency (f0) and speech rate when attempting to sound younger and decreased f0 and speech rate when attempting to sound older. Study 2 showed that the voice manipulations had an effect in the sought-after direction, although the achieved mean effect was only 3 years, which is far less than the intended effect of 20 years. Moreover, listeners used speech rate, but not f0, as a cue to speaker age. It was concluded that age disguise by voice can

  3. Vocal Age Disguise: The Role of Fundamental Frequency and Speech Rate and Its Perceived Effects.

    PubMed

    Skoog Waller, Sara; Eriksson, Mårten

    2016-01-01

    The relationship between vocal characteristics and perceived age is of interest in various contexts, as is the possibility to affect age perception through vocal manipulation. A few examples of such situations are when age is staged by actors, when ear witnesses make age assessments based on vocal cues only or when offenders (e.g., online groomers) disguise their voice to appear younger or older. This paper investigates how speakers spontaneously manipulate two age related vocal characteristics (f0 and speech rate) in attempt to sound younger versus older than their true age, and if the manipulations correspond to actual age related changes in f0 and speech rate (Study 1). Further aims of the paper is to determine how successful vocal age disguise is by asking listeners to estimate the age of generated speech samples (Study 2) and to examine whether or not listeners use f0 and speech rate as cues to perceived age. In Study 1, participants from three age groups (20-25, 40-45, and 60-65 years) agreed to read a short text under three voice conditions. There were 12 speakers in each age group (six women and six men). They used their natural voice in one condition, attempted to sound 20 years younger in another and 20 years older in a third condition. In Study 2, 60 participants (listeners) listened to speech samples from the three voice conditions in Study 1 and estimated the speakers' age. Each listener was exposed to all three voice conditions. The results from Study 1 indicated that the speakers increased fundamental frequency (f0) and speech rate when attempting to sound younger and decreased f0 and speech rate when attempting to sound older. Study 2 showed that the voice manipulations had an effect in the sought-after direction, although the achieved mean effect was only 3 years, which is far less than the intended effect of 20 years. Moreover, listeners used speech rate, but not f0, as a cue to speaker age. It was concluded that age disguise by voice can be

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Variability in heart rate recovery measurements over 1 year in healthy, middle-aged adults.

    PubMed

    Mellis, M G; Ingle, L; Carroll, S

    2014-02-01

    This study assessed the longer-term (12-month) variability in post-exercise heart rate recovery following a submaximal exercise test. Longitudinal data was analysed for 97 healthy middle-aged adults (74 male, 23 female) from 2 occasions, 12 months apart. Participants were retrospectively selected if they had stable physical activity habits, submaximal treadmill fitness and anthropometric measurements between the 2 assessment visits. A submaximal Bruce treadmill test was performed to at least 85% age-predicted maximum heart rate. Absolute heart rate and Δ heart rate recovery (change from peak exercise heart rate) were recorded for 1 and 2 min post-exercise in an immediate supine position. Heart rate recovery at both time-points was shown to be reliable with intra-class correlation coefficient values ≥ 0.714. Absolute heart rate 1-min post-exercise showed the strongest agreement between repeat tests (r = 0.867, P < 0.001). Lower coefficient of variation (≤ 10.2%) and narrower limits of agreement were found for actual heart rate values rather than Δ heart rate recovery, and for 1-min rather than 2-min post-exercise recovery time points. Log-transformed values generated better variability with acceptable coefficient of variation for all measures (2.2-10%). Overall, 1 min post-exercise heart rate recovery data had least variability over the 12-month period in apparently healthy middle-aged adults.

  17. 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.

  18. Experimental evidence of environmental effects on age-specific reproductive success: the importance of resource quality.

    PubMed Central

    Pärt, T.

    2001-01-01

    Age-specific access to high-quality resources (e.g. territory or nest site) might be an important determinant for improved reproductive performance with increasing age. I experimentally investigated the effects of territory quality versus other age-related improvements in breeding competence (e.g. foraging skills, breeding experience and local knowledge) on age-specific reproductive success. Territory quality (i.e. territory field layer height) was manipulated in year 2 of northern wheatears (Oenanthe oenanthe) that were breeding in the same territory in two consecutive years. Changing territory quality by changing field layer height had a strong effect on within-individual change in the reproductive success of wheatears. This effect was mainly due to a corresponding change in nest predation risk. When territory quality was kept constant (i.e. no between-year change in territory field layer height), within-individual reproductive success did not change between subsequent years. Thus, age-related improvements in foraging skills, breeding experience and local familiarity had no significant effect on within-individual changes in reproductive success. Increased reproductive success with increased age in northern wheatears is therefore mainly explained by an improved access to high-quality territories with increasing age. I conclude that age-dependent access to high-quality breeding resources might be a widespread phenomenon in nature. PMID:11674875

  19. Excretion rates of indigestible plastic balls of different specific gravities and diameters in dairy cattle.

    PubMed

    Seyama, Tomohiro; Hirayasu, Hirofumi; Kasai, Koji

    2017-01-01

    We used plastic balls to investigate how their specific gravity and diameter affect excretion rate and rumination in dairy cattle, to develop a capsule that can be used for reaching the lower gastrointestinal tract without physical breakdown and/or degradation in the rumen. Twelve types of indigestible plastic balls composed of a combination of four specific gravities (0.95, 1.19, 1.41, or 2.20) and three diameters (3.97, 6.35, or 7.94 mm) were orally administered to lactating dairy cows, and the balls were collected from feces, after 120 h post-administration, to evaluate the recovery rate. Recovery rate of the balls with specific gravity 1.19 or 1.41 and diameter 6.35 or 7.94 mm was higher than those with specific gravity 0.95 or 2.20 and diameter 3.97 mm. The cumulative recovery rate at 24 and 48 h post-administration was higher for balls with specific gravity 1.19 than that for balls with other specific gravities. These results suggest that specific gravity 1.19 or 1.41 and diameters 6.35-7.94 mm are optimal for use in bypass capsules for administration to cattle. In addition, the passage time of capsules differed between specific gravities 1.19 and 1.41.

  20. 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

  1. 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…

  2. 42 CFR 412.332 - Payment based on the hospital-specific rate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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...

  3. 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.

  4. The receptor for advanced glycation end products (RAGE) specifically recognizes methylglyoxal-derived AGEs.

    PubMed

    Xue, Jing; Ray, Rashmi; Singer, David; Böhme, David; Burz, David S; Rai, Vivek; Hoffmann, Ralf; Shekhtman, Alexander

    2014-05-27

    Diabetes-induced hyperglycemia increases the extracellular concentration of methylglyoxal. Methylglyoxal-derived hydroimidazolones (MG-H) form advanced glycation end products (AGEs) that accumulate in the serum of diabetic patients. The binding of hydroimidozolones to the receptor for AGEs (RAGE) results in long-term complications of diabetes typified by vascular and neuronal injury. Here we show that binding of methylglyoxal-modified albumin to RAGE results in signal transduction. Chemically synthesized peptides containing hydroimidozolones bind specifically to the V domain of RAGE with nanomolar affinity. The solution structure of an MG-H1-V domain complex revealed that the hydroimidazolone moiety forms multiple contacts with a positively charged surface on the V domain. The high affinity and specificity of hydroimidozolones binding to the V domain of RAGE suggest that they are the primary AGE structures that give rise to AGEs-RAGE pathologies.

  5. Heart rate responses of male orienteers aged 21-67 years during competition.

    PubMed

    Bird, S; George, M; Theakston, S; Balmer, J; Davison, R C R

    2003-03-01

    Orienteering is a sport in which it is common for most participants to be aged over 40 years, but research into the demands of the sport has focused almost exclusively on elite participants aged 21-35 years. The aim of the present study was to examine the heart rate responses of older male orienteers. Thirty-nine competitive male orienteers were divided into three groups: group 1 (international competitive standard, n = 11, age 21-67 years), group 2 (national competitive standard, n = 15, age 24-66 years) and group 3 (club competitive standard, n = 13, age 23-60 years). Each participant had his heart rate monitored during two orienteering races of contrasting technical difficulty. The results were analysed using analysis of covariance, with age as a covariate, and Pearson product-moment correlation coefficients to determine whether age was related to the observed heart rate responses. The groups did not differ in their peak (175 +/- 12 beats x min(-1), P = 0.643) or mean (159 +/- 13 beats x min(-1), P = 0.171) heart rates during the races. There was a decline of 6 beats x min(-1) x decade(-1) (P = 0.001) for peak heart rate and 5 beats x min(-1) x decade(-1) (P < 0.001) for mean heart rate. Mean heart rates were 86 +/- 6% of the participants' maximal heart rates and were not associated with age. The orienteers in group 1 displayed a lower (P < 0.005) within-race standard deviation in heart rate (6 +/- 2 beats x min(-1)) than those in groups 2 and 3 (10 +/- 3 and 10 +/- 4 beats x min(-1), respectively). In conclusion, the mean heart rates indicated that all three groups of orienteers ran at a relative high intensity and the international competitive standard orienteers displayed a less variable heart rate, which may have been related to fewer instances of slowing down to relocate and being able to navigate while running at relatively high speeds.

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

    PubMed

    Roth, Timothy C; Krochmal, Aaron R

    2015-02-02

    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.

  7. An International Contrast of Rates of Placental Abruption: An Age-Period-Cohort Analysis

    PubMed Central

    Ananth, Cande V.; Keyes, Katherine M.; Hamilton, Ava; Gissler, Mika; Wu, Chunsen; Liu, Shiliang; Luque-Fernandez, Miguel Angel; Skjærven, Rolv; Williams, Michelle A.; Tikkanen, Minna; Cnattingius, Sven

    2015-01-01

    Background Although rare, placental abruption is implicated in disproportionately high rates of perinatal morbidity and mortality. Understanding geographic and temporal variations may provide insights into possible amenable factors of abruption. We examined abruption frequencies by maternal age, delivery year, and maternal birth cohorts over three decades across seven countries. Methods Women that delivered in the US (n = 863,879; 1979–10), Canada (4 provinces, n = 5,407,463; 1982–11), Sweden (n = 3,266,742; 1978–10), Denmark (n = 1,773,895; 1978–08), Norway (n = 1,780,271, 1978–09), Finland (n = 1,411,867; 1987–10), and Spain (n = 6,151,508; 1999–12) were analyzed. Abruption diagnosis was based on ICD coding. Rates were modeled using Poisson regression within the framework of an age-period-cohort analysis, and multi-level models to examine the contribution of smoking in four countries. Results Abruption rates varied across the seven countries (3–10 per 1000), Maternal age showed a consistent J-shaped pattern with increased rates at the extremes of the age distribution. In comparison to births in 2000, births after 2000 in European countries had lower abruption rates; in the US there was an increase in rate up to 2000 and a plateau thereafter. No birth cohort effects were evident. Changes in smoking prevalence partially explained the period effect in the US (P = 0.01) and Sweden (P<0.01). Conclusions There is a strong maternal age effect on abruption. While the abruption rate has plateaued since 2000 in the US, all other countries show declining rates. These findings suggest considerable variation in abruption frequencies across countries; differences in the distribution of risk factors, especially smoking, may help guide policy to reduce abruption rates. PMID:26018653

  8. Rates and risk factors for progression to incident dementia vary by age in a population cohort

    PubMed Central

    Lee, Ching-Wen; Snitz, Beth E.; Hughes, Tiffany F.; McDade, Eric; Chang, Chung-Chou H.

    2015-01-01

    Objective: To estimate rate of progression from normal cognition or mild impairment to dementia, and to identify potential risk and protective factors for incident dementia, based on age at dementia onset in a prospective study of a population-based cohort (n = 1,982) aged 65 years and older. Methods: Following the cohort annually for up to 5 years, we estimated incidence of dementia (Clinical Dementia Rating ≥1) among individuals previously normal or mildly impaired (Clinical Dementia Rating 0 or 0.5). In the whole cohort, and also stratified by median onset age, we examined several vascular, metabolic, and inflammatory variables as potential risk factors for developing dementia, using interval-censored survival models. Results: Based on 67 incident cases of dementia, incidence rate (per 1,000 person-years) was 10.0 overall, 5.8 in those with median onset age of 87 years or younger, and 31.5 in those with onset age after 87 years. Adjusting for demographics, the risk of incident dementia with onset age of 87 years or younger (n = 33) was significantly increased by baseline smoking, stroke, low systolic blood pressure, and APOE*4 genotype, and reduced by current alcohol use. Among those with dementia with onset after 87 years (n = 34), no risk or protective factor was significant. Conclusion: Risk and protective factors were only found for incident dementia with onset before the median onset age of 87 years, and not for those with later onset. Either unexplored risk factors explain the continued increase in incidence with age, or unknown protective factors are allowing some individuals to delay onset into very old age. PMID:25471390

  9. Aging

    PubMed Central

    Park, Dong Choon

    2013-01-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological aging. Despite the efforts from many researchers, the progression and the mechanisms of aging are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  10. 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.

  11. 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.

  12. The gender-specific association between age at first drink and later alcohol drinking patterns in Korea.

    PubMed

    Kang, Minsun; Kim, Jae-Hyun; Cho, Woo-Hyun; Park, Eun-Cheol

    2014-01-01

    This study investigated the association between the age at first drink and later alcohol drinking patterns, and analyzed whether differences in the association exist among Korean adults according to gender. The subjects included 10,649 adults (5,405 men and 5,244 women) from the fourth Korean National Health and Nutrition Examination Survey between 2007 and 2009, which extracted the standard survey household by using the proportional systematic sampling method. Baseline individual characteristics, the age at first drink, and individual alcohol drinking patterns were obtained by specially trained interviewers or examiners. The association between the age at first drink and the adult alcohol drinking patterns was summarized with odds ratios and their confidence intervals obtained from multiple logistic regression analysis with sampling weights of KNHANES complex sample survey design. The results of this study show that age, co-habitation, occupation, smoking, and self-rated stress level were significantly related to the drinking patterns for men, whereas education, co-habitation, smoking, and self-rated stress level were significant factors for the drinking patterns of women. The association between the age at first drink and the adult alcohol consumption was significant for both genders and, interestingly, the alcohol drinking patterns were significantly differed by gender even after controlling for the individual characteristics. These results imply a need for gender-specific strategies to prevent hazardous alcohol consumption at a later time for Korean.

  13. Age-specific variation in immune response in Drosophila melanogaster has a genetic basis.

    PubMed

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

    2012-07-01

    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.

  14. Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration.

    PubMed

    Elabd, Christian; Cousin, Wendy; Upadhyayula, Pavan; Chen, Robert Y; Chooljian, Marc S; Li, Ju; Kung, Sunny; Jiang, Kevin P; Conboy, Irina M

    2014-06-10

    The regenerative capacity of skeletal muscle declines with age. Previous studies suggest that this process can be reversed by exposure to young circulation; however, systemic age-specific factors responsible for this phenomenon are largely unknown. Here we report that oxytocin--a hormone best known for its role in lactation, parturition and social behaviours--is required for proper muscle tissue regeneration and homeostasis, and that plasma levels of oxytocin decline with age. Inhibition of oxytocin signalling in young animals reduces muscle regeneration, whereas systemic administration of oxytocin rapidly improves muscle regeneration by enhancing aged muscle stem cell activation/proliferation through activation of the MAPK/ERK signalling pathway. We further show that the genetic lack of oxytocin does not cause a developmental defect in muscle but instead leads to premature sarcopenia. Considering that oxytocin is an FDA-approved drug, this work reveals a potential novel and safe way to combat or prevent skeletal muscle ageing.

  15. [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.

  16. Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration

    PubMed Central

    Upadhyayula, Pavan; Chen, Robert Y.; Chooljian, Marc S.; Li, Ju; Kung, Sunny; Jiang, Kevin P.; Conboy, Irina M.

    2014-01-01

    The regenerative capacity of skeletal muscle declines with age. Previous studies suggest that this process can be reversed by exposure to young circulation, but systemic age-specific factors responsible for this phenomenon are largely unknown. Here we report that oxytocin- a hormone best known for its role in lactation, parturition, and social behaviors - is required for proper muscle tissue regeneration and homeostasis, and that plasma levels of oxytocin decline with age. Inhibition of oxytocin signaling in young animals reduces muscle regeneration, whereas systemic administration of oxytocin rapidly improves muscle regeneration by enhancing aged muscle stem cell activation/proliferation throughactivation of the MAPK/ERK signalling pathway. We further show that the genetic lack of oxytocin does not cause a developmental defect in muscle, but instead leads to premature sarcopenia. Considering that oxytocin is an FDA approved drug, this work reveals a potential novel and safe way to combat or prevent skeletal muscle aging. PMID:24915299

  17. Deriving age-specific incidence from prevalence with an ordinary differential equation.

    PubMed

    Brinks, Ralph; Landwehr, Sandra; Icks, Andrea; Koch, Michael; Giani, Guido

    2013-05-30

    This article describes new relationships between the age-specific incidence of, the prevalence of and mortality from a chronic disease. We express these relationships in terms of an ordinary differential equation and form the methodological basis for a novel approach to estimating incidences from age-specific prevalence data. We examine practical aspects of the relationships and a comparison with a known stochastic method in a simulation study. Finally, we apply the novel method to a data set of renal replacement therapy recorded from patients with chronic kidney failure in a region of Germany with approximately 310,000 inhabitants from 2002 to 2010.

  18. 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

  19. 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

  20. Derivation of site-specific skeletal masses within the current ICRP age series.

    PubMed

    Watchman, Christopher J; Hasenauer, Deanna; Bolch, Wesley E

    2007-06-07

    The calculation of absorbed dose to the radiosensitive tissues of the skeleton is routinely performed using reference masses provided in publications from the International Commission on Radiological Protection (ICRP). These values typically include total skeleton tissue masses by reference subject age, but not by individual bone site at a given age. Site-specific variations in absorbed fractions are known to occur for internal alpha-particle and beta-particle emitters, and in certain medical dose reconstructions, site-specific estimates of marrow dose may be desirable. Furthermore, bone-site-specific tissue masses are required to properly estimate skeletal-averaged absorbed fractions and, more importantly, specific absorbed fractions for internalized radionuclides and radiopharmaceuticals. Reference masses by skeletal site are also needed in the development of ICRP compliant tomographic phantoms, as this organ system is initially segmented from medical images only as a homogeneous tissue region. ICRP reference skeletal masses are assigned based upon several independent data sources, many of which may not be entirely consistent with one another. In this study, a methodology is presented, using data from the various ICRP publications, to derive site-specific skeletal tissue masses for each member of the ICRP age series. Active marrow masses are calculated and differences are shown with respect to ICRP Publications 70 and 89 values. New data for a revised surrogate tissue region for the osteoprogenitor cells within bone marrow is presented with estimates of its total mass throughout the skeleton and for different subject ages.

  1. 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.

  2. 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).

  3. Relation of rate of urine production to oxygen tension in small-for-gestational-age fetuses.

    PubMed

    Nicolaides, K H; Peters, M T; Vyas, S; Rabinowitz, R; Rosen, D J; Campbell, S

    1990-02-01

    Hourly fetal urine production rate was determined by real-time ultrasonography immediately before cordocentesis for blood gas analysis in 27 small-for-gestational-age fetuses at 20 to 37 weeks' gestation; in 14 cases there was associated oligohydramnios. The values were compared with those of 101 appropriate-for-gestational-age fetuses. The hourly fetal urine production rate was significantly lower in the small-for-gestational-age fetuses than in the appropriate-for-gestational-age fetuses. Furthermore, there was a significant correlation between the degree of decrease in urine production and both the degree of fetal hypoxemia and the degree of fetal smallness. There was no significant difference between the oligohydramnios and nonoligohydramnios groups in either the degree of decrease in urine production or the degree of fetal hypoxemia.

  4. Age-associated Epstein–Barr virus-specific T cell responses in seropositive healthy adults

    PubMed Central

    Cárdenas Sierra, D; Vélez Colmenares, G; Orfao de Matos, A; Fiorentino Gómez, S; Quijano Gómez, S M

    2014-01-01

    Epstein–Barr virus (EBV) is present in 95% of the world's adult population. The immune response participates in immune vigilance and persistent infection control, and this condition is maintained by both a good quality (functionality) and quantity of specific T cells throughout life. In the present study, we evaluated EBV-specific CD4+ and CD8+ T lymphocyte responses in seropositive healthy individuals younger and older than 50 years of age. The assessment comprised the frequency, phenotype, functionality and clonotypic distribution of T lymphocytes. We found that in both age groups a similar EBV-specific T cell response was found, with overlapping numbers of tumour necrosis factor (TNF)-α+ T lymphocytes (CD4+ and CD8+) within the memory and effector cell compartments, in addition to monofunctional and multi-functional T cells producing interleukin (IL)-2 and/or interferon (IFN)-γ. However, individuals aged more than 50 years showed significantly higher frequencies of IL-2-producing CD4+ T lymphocytes in association with greater production of soluble IFN-γ, TNF-α and IL-6 than subjects younger than 50 years. A polyclonal T cell receptor (TCR)-variable beta region (Vβ) repertoire exists in both age groups under basal conditions and in response to EBV; the major TCR families found in TNF-α+/CD4+ T lymphocytes were Vβ1, Vβ2, Vβ17 and Vβ22 in both age groups, and the major TCR family in TNF-α+/CD8+ T cells was Vβ13·1 for individuals younger than 50 years and Vβ9 for individuals aged more than 50 years. Our findings suggest that the EBV-specific T cell response (using a polyclonal stimulation model) is distributed throughout several T cell differentiation compartments in an age-independent manner and includes both monofunctional and multi-functional T lymphocytes. PMID:24666437

  5. 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.

  6. The Effect of Different Enlistment Ages on First-Term Attrition Rate

    DTIC Science & Technology

    2014-03-01

    as Black, White, Hispanic, other race, and unknown; education level; different enlistment age dummies between 18 and 42; female or male; and AFQT Cat... education level; different enlistment age dummies between 18 and 42; female or male; and AFQT Cat. Unemployment rates by states were included in the...Delayed Entry Program DMDC The Defense Manpower Data Center DOD Department of Defense GED General Education Development JROTC Junior Reserve

  7. 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.

  8. Effects of Nutrients on Specific Growth Rate of Bacterioplankton in Oligotrophic Lake Water Cultures †

    PubMed Central

    Coveney, Michael F.; Wetzel, Robert 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-μm-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. PMID:16348620

  9. 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

  10. Age-Specific Anti-Hepatitis A Virus Seroepidemiology in Italian Travelers: Indications for Anti-Hepatitis A Vaccination.

    PubMed

    Castelli; Carosi; Tebaldi; Pizzocolo; Pisani; Rossitto; Boffelli; Crevatin; Pettoello; Fausti; Messino; Brunelli; Costa; Ronca

    1996-12-01

    Background: Hepatitis A virus (HAV) circulation in the environment is decreasing in most industrialized Western countries. This decrease has lead to low seroprevalence rates in adults. As a consequence, many nonimmune unprotected travelers from areas of low prevalence are considered at risk of acquiring HAV infection when traveling to high HAV endemic areas in developing countries. The recent HAV inactivated vaccine has proved safe and effective, and its use in different geographic areas should be guided by local age-specific HAV seroprevalence rates. The aim of this paper is to describe the age-specific sero-epidemiology of HAV infection in travelers from a highly industrialized region in Northern Italy (Lombardy). Methods: Seven hundred and forty-four consecutive travelers aged from 20 to 59 years, subdivided in 10-year age groups, gave blood samples in the collaborative Health Centers in the Lombardy region and sera were tested for HAV IgG antibodies. A questionnaire was given to travelers that investigated alimentary habits and a history of previous travel. Results: Anti-HAV seroprevalence was 18.0%, 58.0%, 75.8%, and 89.5% in the 20-29, 30-39, 40-49, and 50-59 age groups, respectively. Age was the single most important determinant of anti-HAV seroprevalence. The influence of previous travels, eating shellfish, or ingestion of self-cultivated vegetables was ruled out by multivariate analysis. Conclusions: In the Lombardy region (Northern Italy), age specific anti-HAV seroprevalence rates are much higher than those reported in other Western European countries. The cost-benefit analysis suggested that travelers born after 1960 do not need serologic screening before vaccination. Whenever possible, however, HAV serologic screening is advisable for travelers born before 1960. However, the severity of the disease in older subjects, and the proved safety of HAV vaccination in immune subjects, may advise d'emblée HAV vaccination without prior screening, when serologic

  11. Age- and sex-specific estimation of dose to a normal thyroid from clinical administration of iodine-131

    SciTech Connect

    Killough, G.G.; Eckerman, K.F.

    1986-09-01

    This report describes the derivation of an age- and sex-dependent model of radioiodine dosimetry in the thyroid and the application of the model to estimating the thyroid dose for each of 4215 patients who were exposed to /sup 131/I in diagnostic and therapeutic procedures. In most cases, the data available consisted of the patient's age at the time of administration, the patient's sex, the quantity of activity administered, the clinically determined uptake of radioiodine by the thyroid, and the time after administration at which the uptake was determined. The model was made to conform to these data requirements by the use of age-specific estimates of the biological half-time of iodine in the thyroid and an age- and sex-dependent representation of the mass of the thyroid. Also, it was assumed that the thyroid burden was maximum at 24 hours after administration (the /sup 131/I dose is not critically sensitive to this assumption). The metabolic model is of the form A(t) = K x (exp(-..mu../sub 1/t) - exp(-..mu../sub 2/t)) ..mu..Ci where ..mu../sub i/ = lambda/sub r/ + lambda/sub i//sup b/ (i = 1, 2), lambda/sub r/ is the radiological decay-rate coefficient, and the lambda/sub i//sup b/ are biological removal-rate coefficients. The values of lambda/sub i//sup b/ are determined by solving a nonlinear equation that depends on assumptions about the time of maximum uptake and the eventual biological loss rate (through which age dependence enters). An addendum (Appendix C) extends the method to other radioiodines and gives age- and sex-dependent dose conversion factors for most isotopes.

  12. Effects of aging on mouse tongue epithelium focusing on cell proliferation rate and morphological aspects.

    PubMed

    Carrard, Vinicius Coelho; Pires, Aline Segatto; Badauy, Cristiano Macabu; Rados, Pantelis Varvaki; Lauxen, Isabel Silva; Sant'Ana Filho, Manoel

    2008-11-01

    The aim of this study was to investigate cell proliferation rate and certain morphological features of mouse epithelium as aging progresses. Tongue biopsies were performed on female mice (Mus domesticus domesticus) at 2, 8, 14 and 20 months of age as indicative of adolescence, adulthood, early senescence and senescence, respectively. Histological sections of tongue were stained with hematoxylin-eosin and subjected to silver staining for active nucleolar organizer region counting. Cell proliferation rate and epithelial thickness analysis were carried out. Analysis of variance detected no differences between the groups in terms of numbers of silver-stained dots associated with nucleolar proteins. There was an increase in mean epithelial thickness in adult animals, followed by a gradual reduction until senescence. Mean keratin thickness presented an increase at 8 and 20 months of age. This difference is probably related to puberty, growth or dietary habits. Aging has no influence on oral epithelial proliferation rate in mice. A gradual reduction in epithelial thickness is a feature of aging in mammals. A conspicuous increase in the keratin layer was observed in senescence as an adaptative response to the reduction in epithelial thickness. These results suggest that aging affects the oral epithelium maturation process through a mechanism that is not related to cell proliferation.

  13. 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.

  14. 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.

  15. Effects of maternal age and environment on offspring vital rates in the oleander aphid (Hemiptera: Aphididae).

    PubMed

    Zehnder, Caralyn B; Parris, Melissa A; Hunter, Mark D

    2007-08-01

    Maternal effects have the potential to affect population dynamics and evolution. To affect population dynamics, maternal effects must influence offspring vital rates (birth, death, or movement). Here, we explore the magnitude of nongenetic maternal influence on the vital rates of an insect herbivore and explore predictability of maternal effects with reference to published studies. We experimentally studied the effects of maternal age, host plant species (two Asclepias spp.), and density on offspring vital rates in Aphis nerii, the oleander aphid. Older mothers produced offspring that lived shorter lives, consistent with the "Lansing Effect." Older mothers also produced offspring that matured at a younger age. As maternal age increased, offspring mass at maturity decreased when mothers were on Asclepias syriaca. However, offspring mass was highest from intermediate aged mothers on A. viridis. The absence of maternal density effects seems to exclude maternal density as a potential source of delayed density dependence in A. nerii. Our results indicate that maternal effects have some influence on A. nerii vital rates. However, references to published studies suggest that only the Lansing Effect is a predictable response to maternal age in insects. Moreover, the magnitude of observed effects was generally low.

  16. Division of labour influences the rate of ageing in weaver ant workers.

    PubMed Central

    Chapuisat, Michel; Keller, Laurent

    2002-01-01

    The evolutionary theory of ageing predicts that the timing of senescence has been primarily shaped by the extrinsic mortality rate, which causes selection intensity to decline over time. One difficulty in testing the evolutionary theory of ageing is that extrinsic mortality risk is often confounded with body size and fecundity, which may also directly affect lifespan. Social insects with a pronounced division of labour between worker castes provide a unique opportunity to study the direct effect of extrinsic mortality on the evolution of ageing rates independently of body size, reproductive effort and genetic configuration. In the weaver ant, Oecophylla smaragdina, the major (large) workers perform the risky tasks outside the nest, while the minor (small) workers stay within the highly protected arboreal nest. Hence, this pronounced division of labour is associated with high differences in extrinsic mortality risks. The evolutionary theory of ageing predicts that the minor workers should have a longer intrinsic lifespan than the major workers. In line with this prediction, we found that in a protected environment the minor workers lived significantly longer than the major workers did. Hence, the ageing rate appears to have been moulded by variation in the extrinsic mortality rate independently of size, reproductive effort and genetic configuration. PMID:12028773

  17. The rate of change in declining steroid hormones: a new parameter of healthy aging in men?

    PubMed Central

    Walther, Andreas; Philipp, Michel; Lozza, Niclà; Ehlert, Ulrike

    2016-01-01

    Research on healthy aging in men has increasingly focused on age-related hormonal changes. Testosterone (T) decline is primarily investigated, while age-related changes in other sex steroids (dehydroepiandrosterone [DHEA], estradiol [E2], progesterone [P]) are mostly neglected. An integrated hormone parameter reflecting aging processes in men has yet to be identified. 271 self-reporting healthy men between 40 and 75 provided both psychometric data and saliva samples for hormone analysis. Correlation analysis between age and sex steroids revealed negative associations for the four sex steroids (T, DHEA, E2, and P). Principal component analysis including ten salivary analytes identified a principal component mainly unifying the variance of the four sex steroid hormones. Subsequent principal component analysis including the four sex steroids extracted the principal component of declining steroid hormones (DSH). Moderation analysis of the association between age and DSH revealed significant moderation effects for psychosocial factors such as depression, chronic stress and perceived general health. In conclusion, these results provide further evidence that sex steroids decline in aging men and that the integrated hormone parameter DSH and its rate of change can be used as biomarkers for healthy aging in men. Furthermore, the negative association of age and DSH is moderated by psychosocial factors. PMID:27589836

  18. The rate of change in declining steroid hormones: a new parameter of healthy aging in men?

    PubMed

    Walther, Andreas; Philipp, Michel; Lozza, Niclà; Ehlert, Ulrike

    2016-09-20

    Research on healthy aging in men has increasingly focused on age-related hormonal changes. Testosterone (T) decline is primarily investigated, while age-related changes in other sex steroids (dehydroepiandrosterone [DHEA], estradiol [E2], progesterone [P]) are mostly neglected. An integrated hormone parameter reflecting aging processes in men has yet to be identified. 271 self-reporting healthy men between 40 and 75 provided both psychometric data and saliva samples for hormone analysis. Correlation analysis between age and sex steroids revealed negative associations for the four sex steroids (T, DHEA, E2, and P). Principal component analysis including ten salivary analytes identified a principal component mainly unifying the variance of the four sex steroid hormones. Subsequent principal component analysis including the four sex steroids extracted the principal component of declining steroid hormones (DSH). Moderation analysis of the association between age and DSH revealed significant moderation effects for psychosocial factors such as depression, chronic stress and perceived general health. In conclusion, these results provide further evidence that sex steroids decline in aging men and that the integrated hormone parameter DSH and its rate of change can be used as biomarkers for healthy aging in men. Furthermore, the negative association of age and DSH is moderated by psychosocial factors.

  19. Age and rate of diversification of the Hawaiian silversword alliance (Compositae)

    PubMed Central

    Baldwin, Bruce G.; Sanderson, Michael J.

    1998-01-01

    Comparisons between insular and continental radiations have been hindered by a lack of reliable estimates of absolute diversification rates in island lineages. We took advantage of rate-constant rDNA sequence evolution and an “external” calibration using paleoclimatic and fossil data to determine the maximum age and minimum diversification rate of the Hawaiian silversword alliance (Compositae), a textbook example of insular adaptive radiation in plants. Our maximum-age estimate of 5.2 ± 0.8 million years ago for the most recent common ancestor of the silversword alliance is much younger than ages calculated by other means for the Hawaiian drosophilids, lobelioids, and honeycreepers and falls approximately within the history of the modern high islands (≤5.1 ± 0.2 million years ago). By using a statistically efficient estimator that reduces error variance by incorporating clock-based estimates of divergence times, a minimum diversification rate for the silversword alliance was estimated to be 0.56 ± 0.17 species per million years. This exceeds average rates of more ancient continental radiations and is comparable to peak rates in taxa with sufficiently rich fossil records that changes in diversification rate can be reconstructed. PMID:9689092

  20. 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.

  1. Estimation of waste component-specific landfill decay rates using laboratory-scale decomposition data.

    PubMed

    De la Cruz, Florentino B; Barlaz, Morton A

    2010-06-15

    The current methane generation model used by the U.S. EPA (Landfill Gas Emissions Model) treats municipal solid waste (MSW) as a homogeneous waste with one decay rate. However, component-specific decay rates are required to evaluate the effects of changes in waste composition on methane generation. Laboratory-scale rate constants, k(lab), for the major biodegradable MSW components were used to derive field-scale decay rates (k(field)) for each waste component using the assumption that the average of the field-scale decay rates for each waste component, weighted by its composition, is equal to the bulk MSW decay rate. For an assumed bulk MSW decay rate of 0.04 yr(-1), k(field) was estimated to be 0.298, 0.171, 0.015, 0.144, 0.033, 0.02, 0.122, and 0.029 yr(-1), for grass, leaves, branches, food waste, newsprint, corrugated containers, coated paper, and office paper, respectively. The effect of landfill waste diversion programs on methane production was explored to illustrate the use of component-specific decay rates. One hundred percent diversion of yard waste and food waste reduced the year 20 methane production rate by 45%. When a landfill gas collection schedule was introduced, collectable methane was most influenced by food waste diversion at years 10 and 20 and paper diversion at year 40.

  2. 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.

  3. School-Age Prework Experiences of Young People with a History of Specific Language Impairment

    ERIC Educational Resources Information Center

    Durkin, Kevin; Fraser, Jill; Conti-Ramsden, Gina

    2012-01-01

    Young people with specific language impairment (SLI) are at risk for poorer outcomes with respect to employment in adulthood, yet little is known of how early school-age prework experiences prepare them for the job market. This study examined whether young people with SLI engage in similar types of early work experiences as their typically…

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

    PubMed

    Immonen, E; Collet, M; Goenaga, J; Arnqvist, G

    2016-03-01

    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 that 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 not only 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.

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

    PubMed Central

    Immonen, E; Collet, M; Goenaga, J; Arnqvist, G

    2016-01-01

    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 that 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 not only 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. 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…

  7. 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

  8. Socioeconomic inequalities in mortality rates in old age in the World Health Organization Europe region.

    PubMed

    Huisman, Martijn; Read, Sanna; Towriss, Catriona A; Deeg, Dorly J H; Grundy, Emily

    2013-01-01

    Socioeconomic adversity is among the foremost fundamental causes of human suffering, and this is no less true in old age. Recent reports on socioeconomic inequalities in mortality rate in old age suggest that a low socioeconomic position continues to increase the risk of death even among the oldest old. We aimed to examine the evidence for socioeconomic mortality rate inequalities in old age, including information about associations with various indicators of socioeconomic position and for various geographic locations within the World Health Organization Region for Europe. The articles included in this review leave no doubt that inequalities in mortality rate by socioeconomic position persist into the oldest ages for both men and women in all countries for which information is available, although the relative risk measures observed were rarely higher than 2.00. Still, the available evidence base is heavily biased geographically, inasmuch as it is based largely on national studies from Nordic and Western European countries and local studies from urban areas in Southern Europe. This bias will hamper the design of European-wide policies to reduce inequalities in mortality rate. We call for a continuous update of the empiric evidence on socioeconomic inequalities in mortality rate.

  9. 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

  10. Facilitating interdisciplinary design specification of "smart" homes for aging in place.

    PubMed

    Demiris, George; Skubic, Marjorie; Rantz, Marilyn J; Courtney, Karen L; Aud, Myra A; Tyrer, Harry W; He, Zhihai; Lee, Jia

    2006-01-01

    "Smart homes" are defined as residences equipped with sensors and other advanced technology applications that enhance residents' independence and can be used for aging in place. The objective of this study is to determine design specifications for smart residences as defined by professional groups involved both in care delivery to senior citizens and development of devices and technologies to support aging. We assessed the importance of specific devices and sensors and their advantages and disadvantages as perceived by the interdisciplinary expert team. This work lays the ground for the implementation of smart home residencies and confirms that only an interdisciplinary design approach can address all the technical, clinical and human factors related challenges associated with home-based technologies that support aging. Our findings indicate that the use of adaptive technology that can be installed in the home environment has the potential to not only support but also empower individual senior users.

  11. Semi-parametric estimation of age-time specific infection incidence from serial prevalence data.

    PubMed

    Nagelkerke, N; Heisterkamp, S; Borgdorff, M; Broekmans, J; Van Houwelingen, H

    1999-02-15

    Many infections cause lasting detectable immune responses, whose prevalence can be estimated from cross-sectional surveys. However, such surveys do not provide direct information on the incidence of infection. We address the issue of estimating age and time specific incidence from a series of prevalence surveys under the assumption that incidence changes exponentially with time, but make no assumption about the age specific incidence. We show that these assumptions lead to a proportional hazards model and estimate its parameters using semi-parametric maximum likelihood methods. The method is applied to tuberculin surveys in The Netherlands to explore age dependence of the risk of tuberculous infection in the presence of a strong secular decline in this risk.

  12. 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.

  13. Wuchereria bancrofti filariasis in French Polynesia: age-specific patterns of microfilaremia, circulating antigen, and specific IgG and IgG4 responses according to transmission level.

    PubMed

    Chanteau, S; Glaziou, P; Plichart, C; Luquiaud, P; Moulia-Pelat, J P; N'Guyen, L; Cartel, J L

    1995-01-01

    The age-specific patterns of microfilaremia, Og4C3 antigenemia, anti-Brugia malayi IgG and IgG4 were assessed in 3 villages of low, medium and high transmission level for Wuchereria bancrofti filariasis. The prevalence rates for each of the 4 markers were clearly age dependent and their patterns strongly associated with the transmission level. The antigenemia prevalence rate was consistently higher than the microfilaremia prevalence rate, in all age groups. The prevalences of anti-B. malayi IgG and IgG4 responses were very similar and much higher than those of microfilaremia or antigenemia. Antibody responses reached the plateau at an earlier age and at a higher prevalence with increased intensity of transmission. For all the markers, the prevalence rates were significantly higher in males than in females.

  14. 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

  15. Experimental evidence that age-specific reproductive success is independent of environmental effects

    PubMed Central

    Daunt, F.; Wanless, S.; Harris, M. P.; Monaghan, P.

    1999-01-01

    An age-specific improvement in reproductive performance has been reported in many iteroparous breeders. However, whether this is a consequence of intrinsic differences in competence amongst age classes or extrinsic differences in the environment they experience is unclear since the timing of breeding within a season generally also differs with age. To disentangle these effects, we experimentally manipulated the timing of breeding in shags, Phalacrocorax aristotelis. Old and young individuals thus reared their chicks at the same time both early and late in the breeding season. When breeding in the same environmental conditions, old pairs performed consistently better than young pairs. These data clearly demonstrate that the age-related differences in reproductive performance are not a result of environmental effects, but rather a consequence of intrinsic differences in brood rearing capacity.

  16. Age-Dependent Changes in the Cerebrospinal Fluid Proteome by Slow Off-Rate Modified Aptamer Array

    PubMed Central

    Baird, Geoffrey S.; Nelson, Sally K.; Keeney, Tracy R.; Stewart, Alex; Williams, Stephen; Kraemer, Stephan; Peskind, Elaine R.; Montine, Thomas J.

    2012-01-01

    An important precondition for the successful development of diagnostic assays of cerebrospinal fluid (CSF) biomarkers of age-related neurodegenerative diseases is an understanding of the dynamic nature of the CSF proteome during the normal aging process. In this study, a novel proteomic technology was used to quantify hundreds of proteins simultaneously in the CSF from 90 cognitively normal adults 21 to 85 years of age. SomaLogic's highly multiplexed proteomic platform can measure more than 800 proteins simultaneously from small volumes of biological fluids using novel slow off-rate modified aptamer (SOMAmer) protein affinity reagents with sensitivity, specificity, and dynamic ranges that meet or exceed those of enzyme-linked immunosorbent assays. In the first application of this technology to CSF, we detected 248 proteins that possessed signals greater than twofold over background. Several novel correlations between detected protein concentrations and age were discovered that indicate that both inflammation and response to injury in the central nervous system may increase with age. Applying this powerful proteomic approach to CSF provides potential new insight into the aging of the human central nervous system that may have utility in discovering new disease-related changes in the CSF proteome. PMID:22122984

  17. 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

  18. Does Bioavailability Limit Biodegradability? A Comparison of Hydrocarbon Biodegradation and Desorption Rates in Aged Soils

    SciTech Connect

    Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

    2004-08-01

    In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons do not need to be transferred into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment period when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.

  19. Does bioavailability limit biodegradation? A comparison of hydrocarbon biodegradation and desorption rates in aged soils.

    PubMed

    Huesemann, Michael H; Hausmann, Tom S; Fortman, Tim J

    2004-08-01

    In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons apparently do not need to be dissolved into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment period when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.

  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. 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

  2. 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…

  3. 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,…

  4. Rate of de novo mutations and the importance of father's age to disease risk.

    PubMed

    Kong, Augustine; Frigge, Michael L; Masson, Gisli; Besenbacher, Soren; Sulem, Patrick; Magnusson, Gisli; Gudjonsson, Sigurjon A; Sigurdsson, Asgeir; Jonasdottir, Aslaug; Jonasdottir, Adalbjorg; Wong, Wendy S W; Sigurdsson, Gunnar; Walters, G Bragi; Steinberg, Stacy; Helgason, Hannes; Thorleifsson, Gudmar; Gudbjartsson, Daniel F; Helgason, Agnar; Magnusson, Olafur Th; Thorsteinsdottir, Unnur; Stefansson, Kari

    2012-08-23

    Mutations generate sequence diversity and provide a substrate for selection. The rate of de novo mutations is therefore of major importance to evolution. Here we conduct a study of genome-wide mutation rates by sequencing the entire genomes of 78 Icelandic parent-offspring trios at high coverage. We show that in our samples, with an average father's age of 29.7, the average de novo mutation rate is 1.20 × 10(-8) per nucleotide per generation. Most notably, the diversity in mutation rate of single nucleotide polymorphisms is dominated by the age of the father at conception of the child. The effect is an increase of about two mutations per year. An exponential model estimates paternal mutations doubling every 16.5 years. After accounting for random Poisson variation, father's age is estimated to explain nearly all of the remaining variation in the de novo mutation counts. These observations shed light on the importance of the father's age on the risk of diseases such as schizophrenia and autism.

  5. 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.

  6. 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…

  7. 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

  8. 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.

  9. Incidence rates of specific histological types of lung cancer in Singapore Chinese dialect groups, and their aetiological significance.

    PubMed

    Law, C H; Day, N E; Shanmugaratnam, K

    1976-03-15

    Significant differences in the incidence levels of lung cancer have been observed among major Chinese dialect groups or communities (Kokkien, Teochew and Cantonese) in Singapore. Among males, the incidence rate is highest in the Hokkiens (age-standardized incidence rate per 100,000 persons per year in Hokkien 67.8, Teochew 55.3, Cantonese 54.0) and among females, it is highest in the Cantonese (Hokkien 12.4, Teochew 12.8, Cantonese 27.2). The present investigation was undertaken to determine the incidence rates of each of the main histological types of lung cancer in the Chinese population and to determine whether there are any correlations between histological patterns and the dialect group differentials that may be of aetiological significance. During the period 1968-1972, a total of 1,747 cases of lung cancer (1,285 males and 462 females) were reported to the Singapore Cancer Registry. It proved possible to type the neoplasms histologically in 476 males (37.0%) and 154 females (33.3%). Age-standardized rates by histological type were computed on the assumption that those histologically typed were a representative sample of all lung cancers. This study shows that Hokkien males have a significantly higher incidence rate of epidermoid carcinoma than the other dialect groups (Hokkien 36.1, Teochew 21.1, Cantonese 17.3). The Cantonese females have significantly higher incidence rates of both epidermoid carcinoma (Hokkien 3.7, Teochew 2.3, Cantonese 5.9) and adenocarcinoma (Hokkien 4.6, Teochew 3.6, Cantonese 11.9). Various sources of bias in studied of this type were examined; it is concluded that the differences in the histologic-specific incidence rates of lung cancer among the various Chinese dialect groups in Singapore are real and not artefactual. The significance of these findings in relation to possible aetiological factors is discussed.

  10. Age-specific measles mortality during the late 19th-early 20th centuries.

    PubMed

    Shanks, G D; Waller, M; Briem, H; Gottfredsson, M

    2015-12-01

    Measles mortality fell prior to the introduction of vaccines or antibiotics. By examining historical mortality reports we sought to determine how much measles mortality was due to epidemiological factors such as isolation from major population centres or increased age at time of infection. Age-specific records were available from Aberdeen; Scotland; New Zealand and the states of Australia at the end of the 19th and beginning of the 20th centuries. Despite the relative isolation of Australia, measles mortality was concentrated in very young children similar to Aberdeen. In the more isolated states of Tasmania, Western Australia and Queensland adults made up 14-15% of measles deaths as opposed to 8-9% in Victoria, South Australia and New South Wales. Mortality in Iceland and Faroe Islands during the 1846 measles epidemic was used as an example of islands isolated from respiratory pathogens. The transition from crisis mortality across all ages to deaths concentrated in young children occurred prior to the earliest age-specific mortality data collected. Factors in addition to adult age of infection and epidemiological isolation such as nutritional status and viral virulence may have contributed to measles mortality outcomes a century ago.

  11. Specific Age-Associated DNA Methylation Changes in Human Dermal Fibroblasts

    PubMed Central

    Lin, Qiong; Bork, Simone; Goergens, Maria; Joussen, Sylvia; Pallua, Norbert; Ho, Anthony D.; Zenke, Martin; Wagner, Wolfgang

    2011-01-01

    Epigenetic modifications of cytosine residues in the DNA play a critical role for cellular differentiation and potentially also for aging. In mesenchymal stromal cells (MSC) from human bone marrow we have previously demonstrated age-associated methylation changes at specific CpG-sites of developmental genes. In continuation of this work, we have now isolated human dermal fibroblasts from young (<23 years) and elderly donors (>60 years) for comparison of their DNA methylation profiles using the Infinium HumanMethylation27 assay. In contrast to MSC, fibroblasts could not be induced towards adipogenic, osteogenic and chondrogenic lineage and this is reflected by highly significant differences between the two cell types: 766 CpG sites were hyper-methylated and 752 CpG sites were hypo-methylated in fibroblasts in comparison to MSC. Strikingly, global DNA methylation profiles of fibroblasts from the same dermal region clustered closely together indicating that fibroblasts maintain positional memory even after in vitro culture. 75 CpG sites were more than 15% differentially methylated in fibroblasts upon aging. Very high hyper-methylation was observed in the aged group within the INK4A/ARF/INK4b locus and this was validated by pyrosequencing. Age-associated DNA methylation changes were related in fibroblasts and MSC but they were often regulated in opposite directions between the two cell types. In contrast, long-term culture associated changes were very consistent in fibroblasts and MSC. Epigenetic modifications at specific CpG sites support the notion that aging represents a coordinated developmental mechanism that seems to be regulated in a cell type specific manner. PMID:21347436

  12. Time Outdoors at Specific Ages During Early Childhood and the Risk of Incident Myopia

    PubMed Central

    Shah, Rupal L.; Huang, Yu; Guggenheim, Jeremy A.; Williams, Cathy

    2017-01-01

    Purpose Time outdoors during childhood is negatively associated with incident myopia. Consequently, additional time outdoors has been suggested as a public health intervention to reduce the prevalence of myopia. We investigated whether there were specific ages during early childhood when the time outdoors versus incident myopia association was strongest. Methods Children participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) were studied from age 2 to 15 years. Parentally reported time outdoors and time spent reading were assessed longitudinally in early childhood (ages 2, 3, 4, 5, 7, and 9 years). Noncycloplegic autorefraction was carried out longitudinally in later childhood (ages 10, 11, 12, and 15 years). Information was available for 2833 participants. Cox proportional hazards regression was used to test for association between time outdoors and incident myopia. Results From 3 years of age onward, greater time outdoors was associated with a reduced risk of incident myopia. The hazard ratio for myopia changed progressively from 0.90 (95% CI 0.83–0.98, P = 0.012) at age 3 years, to 0.86 (95% CI 0.78–0.93, P = 0.001) at age 9 years, for each additional SD of time spent outdoors per day. These associations were independent of two major risk factors for myopia: time reading and number of myopic parents. Conclusions Additional time spent outdoors across the 3 to 9 years age range was associated with a reduced incidence of myopia between ages 10 and 15 years. There was a trend for the association to increase toward the older end of the 3 to 9 years range. PMID:28245296

  13. The age-specific force of natural selection and biodemographic walls of death

    PubMed Central

    Wachter, Kenneth W.; Evans, Steven N.; Steinsaltz, David

    2013-01-01

    W. D. Hamilton’s celebrated formula for the age-specific force of natural selection furnishes predictions for senescent mortality due to mutation accumulation, at the price of reliance on a linear approximation. Applying to Hamilton’s setting the full nonlinear demographic model for mutation accumulation recently developed by Evans, Steinsaltz, and Wachter, we find surprising differences. Nonlinear interactions cause the collapse of Hamilton-style predictions in the most commonly studied case, refine predictions in other cases, and allow walls of death at ages before the end of reproduction. Haldane’s principle for genetic load has an exact but unfamiliar generalization. PMID:23657010

  14. Exploring the specificity of age-related differences in theory of mind tasks.

    PubMed

    Slessor, Gillian; Phillips, Louise H; Bull, Rebecca

    2007-09-01

    Tasks assessing theory of mind (ToM) and non-mental state control tasks were administered to young and older adults to examine previous contradictory findings about age differences in mental state decoding. Age differences were found on a verbal ToM task after controlling for vocabulary levels. Older adults achieved significantly lower scores than did younger adults on static and dynamic visual ToM tasks, and a similar pattern was found on non-ToM control tasks. Rather than a specific ToM deficit, older adults exhibited a more general impairment in the ability to decode cues from verbal and visual information about people.

  15. Age-specific occurrence of HPV16- and HPV18-related cervical cancer

    PubMed Central

    Quint, Wim G. V.; Hunt, William C.; Joste, Nancy E.; Alemany, Laia; Bosch, F. Xavier; Myers, Evan R.; Castle, Philip E.

    2014-01-01

    The age-specific of occurrence of cervical cancer related to human papillomavirus genotypes HPV16 and HPV18, the two targeted by current HPV vaccines, is not well described. We therefore used data from two large, tissue-based HPV genotyping studies of cervical cancer, one conducted in New Mexico (USA) (n = 744) and an international study restricted to cancers (n = 1,729) from Europe, North America, and Australia to represent those regions with widely available cervical cancer screening facilities. HPV results were categorized as HPV16 or HPV18 positive (HPV16/18) versus other HPV genotype. We observed a decreasing proportion of HPV16/18-positive cancers with increasing age in the international study (ptrend < 0.001) and New Mexico study (ptrend < 0.001). There was no heterogeneity in the relationship between age of diagnosis and the proportion of HPV16/18-positive cancers between studies (p = 0.8). Combining results from the two studies (n = 2,473), the percentages of HPV16/18-positive cases were 77.0% (95%CI: 75.1%-78.9%) for women less than 65 years old and 62.7% (95%CI: 58.4%-66.9%) for women aged 65 and older (p < 0.001). In women who are under the age of 25 and have been vaccinated before becoming sexually active, the cervical cancer incidence is expected to be approximately 3.5 per million by 2020. HPV vaccination against HPV16/18 may have a greater impact on cervical cancers in women under 65 than in women aged 65 and older. These data will inform the age-specific impact of HPV vaccination and its integration with cervical cancer screening activities. PMID:23632816

  16. Integration of aerial imaging and variable-rate technology for site-specific aerial herbicide application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As remote sensing and variable rate technology are becoming more available for aerial applicators, practical methodologies on effective integration of these technologies are needed for site-specific aerial applications of crop production and protection materials. The objectives of this study were to...

  17. B1-based specific energy absorption rate determination for nonquadrature radiofrequency excitation.

    PubMed

    Katscher, Ulrich; Findeklee, Christian; Voigt, Tobias

    2012-12-01

    The current gold standard to estimate local and global specific energy absorption rate for MRI involves numerically modeling the patient and the transmit radiofrequency coil. Recently, a patient-individual method was presented, which estimated specific energy absorption rate from individually measured B(1) maps. This method, however, was restricted to quadrature volume coils due to difficulties distinguishing phase contributions from radiofrequency transmission and reception. In this study, a method separating these two phase contributions by comparing the electric conductivity reconstructed from different transmit channels of a parallel radiofrequency transmission system is presented. This enables specific energy absorption rate estimation not only for quadrature excitation but also for the nonquadrature excitation of the single elements of the transmit array. Though the contributions of the different phases are known, unknown magnetic field components and tissue boundary artifacts limit the technique. Nevertheless, the high agreement between simulated and experimental results found in this study is promising. B(1)-based specific energy absorption rate determination might become possible for arbitrary radiofrequency excitation on a patient-individual basis.

  18. 42 CFR 412.79 - Determination of the hospital-specific rate for inpatient operating costs for Medicare-dependent...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... amount (target amount) for a particular covered discharge. (f) Notice of hospital-specific rate. The... adjustment to the hospital-specific rate to ensure that changes to the DRG classifications and...

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. Scattering rates and specific heat jumps in high-Tc cuprates

    NASA Astrophysics Data System (ADS)

    Storey, James

    Inspired by recent ARPES and tunneling studies on high-Tc cuprates, we examine the effect of a pair-breaking term in the self-energy on the shape of the electronic specific heat jump. It is found that the observed specific heat jump can be described in terms of a superconducting gap, that persists above the observed Tc, in the presence of a strongly temperature dependent pair-breaking scattering rate. An increase in the scattering rate is found to explain the non-BCS-like suppression of the specific heat jump with magnetic field. A discussion of these results in the context of other properties such as the superfluid density and Raman spectra will also be presented. Supported by the Marsden Fund Council from Government funding, administered by the Royal Society of New Zealand.

  4. The appropriate threshold for declaring linkage when allowing sex-specific recombination rates.

    PubMed Central

    Lander, E S; Lincoln, S E

    1988-01-01

    In human genetics, two loci are declared to be linked when the lod score at the maximum likelihood recombination fraction theta exceeds the threshold of 3.0. Since recombination rates differ between the sexes, one can alternatively detect linkage by estimating separate recombination rates, theta m and theta f, for male and female meiosis and examining the corresponding sex-specific lod scores. The question arises: In order to maintain the same chance of falsely declaring linkage, what is the correct threshold for declaring linkage when sex-specific lod scores are used? We show here that the appropriate threshold is about 3.5. If the restriction that theta f greater than theta m is added, the appropriate threshold falls to about 3.25. We also discuss the relative efficiency of detecting linkage by using sex-specific and sex-averaged lod scores. PMID:3177382

  5. National sex-specific trends in hospital-based stroke rates.

    PubMed

    Ovbiagele, Bruce

    2011-11-01

    Mounting regional and national evidence suggests a decline in primary in-hospital stroke diagnoses. However, these data do not include secondary diagnoses of stroke, and little is known about whether this decline varies significantly by sex. Compared with men, women are less likely to have optimal control of stroke risk factors, which may be leading to less impressive declines in stroke incidence in women. This study evaluated sex trends in hospital-based stroke diagnoses in the United States. The study was a time-trend analysis by sex of national age-adjusted rates of primary or secondary hospital-based stroke diagnosis per 100,000 persons (identified by ICD-9 procedure codes) among patients for 1997-2006 using data from all US states contributing to the Nationwide Inpatient Sample. Adjustments were made to correct for some inaccuracies in diagnostic codes. Between 1997 and 2006, total hospital-based stroke diagnoses decreased from 680,607 to 609,359. The age-adjusted hospital-based stroke diagnosis rate per 100,000 persons decreased in a roughly linear pattern from 282.7 to 210.4 in men (26%; P < .001) and from 240.5 to 184.7 in women (23%; P < .05). The average rate of decrease (slope) in hospital-based stroke diagnosis rates was greater in men than in women (-8.7 vs -7.5 per 100,000 persons; P = .003). Age-adjusted rates of hospital-based stroke diagnoses have decreased substantially in the United States during the last decade, but slightly less so in women. These results are generally encouraging, but nonetheless indicate that more intensive preventive efforts are warranted to completely eliminate sex disparities in stroke occurrence.

  6. Genetic contribution to rate of change in functional abilities among Danish twins aged 75 years or more.

    PubMed

    Christensen, Kaare; Gaist, David; Vaupel, James W; McGue, Matt

    2002-01-15

    In a previous cross-sectional study of twins, the authors found evidence of a substantial genetic influence on functional abilities among elderly women. It has been suggested that rate of change in functional abilities over time could underlie such findings and that rate-of-change phenotypes may have an even larger genetic component than "level" phenotypes (e.g., functional abilities per se). If so, rate-of-change phenotypes could be more powerful than level phenotypes in studies aimed at identifying specific polymorphisms of importance for aging. In 1995, the authors assessed a population-based sample of 2,401 Danish twins aged 75 years or more. The survivors were recontacted after 2 years and again after 4 years. Consistent mean-level declines, high within-person correlations over time, and substantial heritability in the female sample were observed for functional abilities. Nonetheless, structural-equation analyses revealed only a very modest and nonsignificant heritability for rate of change in functional abilities: 16% (95% confidence interval: 0, 35) for women and 9% (95% confidence interval: 0, 44) for men. This study had a large initial sample size, high participation rates, and a valid and reliable measure of rate of change in a phenotype that had previously shown substantial heritability in cross-sectional analyses in the same twin population. Still, the present study revealed only a modest and nonsignificant genetic influence on rate of change, which suggests that detection of polymorphisms influencing rate of change in functional abilities among the elderly may prove to be difficult.

  7. Phytoplankton production and taxon-specific growth rates in the Costa Rica Dome

    PubMed Central

    Selph, Karen E.; Landry, Michael R.; Taylor, Andrew G.; Gutiérrez-Rodríguez, Andrés; Stukel, Michael R.; Wokuluk, John; Pasulka, Alexis

    2016-01-01

    During summer 2010, we investigated phytoplankton production and growth rates at 19 stations in the eastern tropical Pacific, where winds and strong opposing currents generate the Costa Rica Dome (CRD), an open-ocean upwelling feature. Primary production (14C-incorporation) and group-specific growth and net growth rates (two-treatment seawater dilution method) were estimated from samples incubated in situ at eight depths. Our cruise coincided with a mild El Niño event, and only weak upwelling was observed in the CRD. Nevertheless, the highest phytoplankton abundances were found near the dome center. However, mixed-layer growth rates were lowest in the dome center (∼0.5–0.9 day−1), but higher on the edge of the dome (∼0.9–1.0 day−1) and in adjacent coastal waters (0.9–1.3 day−1). We found good agreement between independent methods to estimate growth rates. Mixed-layer growth rates of Prochlorococcus and Synechococcus were largely balanced by mortality, whereas eukaryotic phytoplankton showed positive net growth (∼0.5–0.6 day−1), that is, growth available to support larger (mesozooplankton) consumer biomass. These are the first group-specific phytoplankton rate estimates in this region, and they demonstrate that integrated primary production is high, exceeding 1 g C m−2 day−1 on average, even during a period of reduced upwelling. PMID:27275025

  8. 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.

  9. 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

  10. Reduction in single muscle fiber rate of force development with aging is not attenuated in world class older masters athletes.

    PubMed

    Power, Geoffrey A; Minozzo, Fábio C; Spendiff, Sally; Filion, Marie-Eve; Konokhova, Yana; Purves-Smith, Maddy F; Pion, Charlotte; Aubertin-Leheudre, Mylène; Morais, José A; Herzog, Walter; Hepple, Russell T; Taivassalo, Tanja; Rassier, Dilson E

    2016-02-15

    Normal adult aging is associated with impaired muscle contractile function; however, to what extent cross-bridge kinetics are altered in aging muscle is not clear. We used a slacken restretch maneuver on single muscle fiber segments biopsied from the vastus lateralis of young adults (∼23 yr), older nonathlete (NA) adults (∼80 yr), and age-matched world class masters athletes (MA; ∼80 yr) to assess the rate of force redevelopment (ktr) and cross-bridge kinetics. A post hoc analysis was performed, and only the mechanical properties of "slow type" fibers based on unloaded shortening velocity (Vo) measurements are reported. The MA and NA were ∼54 and 43% weaker, respectively, for specific force compared with young. Similarly, when force was normalized to cross-sectional area determined via the fiber shape angularity data, both old groups did not differ, and the MA and NA were ∼43 and 48% weaker, respectively, compared with young (P < 0.05). Vo for both MA and NA old groups was 62 and 46% slower, respectively, compared with young. Both MA and NA adults had approximately two times slower values for ktr compared with young. The slower Vo in both old groups relative to young, coupled with a similarly reduced ktr, suggests impaired cross-bridge kinetics are responsible for impaired single fiber contractile properties with aging. These results challenge the widely accepted resilience of slow type fibers to cellular aging.

  11. 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.

  12. 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.

  13. [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.

  14. Tissue-specific Insulin Signaling in the Regulation of Metabolism and Aging

    PubMed Central

    Zhang, Jingjing

    2014-01-01

    In mammals, insulin signaling regulates glucose homeostasis and plays an essential role in metabolism, organ growth, development, fertility, and lifespan. Defects in this signaling pathway contribute to various metabolic diseases such as type 2 diabetes, polycystic ovarian disease, hypertension, hyperlipidemia, and atherosclerosis. However, reducing the insulin signaling pathway has been found to increase longevity and delay the aging-associated diseases in various animals, ranging from nematodes to mice. These seemly paradoxical findings raise an interesting question as to how modulation of the insulin signaling pathway could be an effective approach to improve metabolism and aging. In this review, we summarize current understanding on tissue-specific functions of insulin signaling in the regulation of metabolism and lifespan. We also discuss potential benefits and limitations in modulating tissue-specific insulin signaling pathway to improve metabolism and healthspan. PMID:25087968

  15. 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.

  16. Age-Stratified Treatment Response Rates in Hospitalized Patients with Clostridium difficile Infection Treated with Metronidazole.

    PubMed

    Pham, Vy P; Luce, Andrea M; Ruppelt, Sara C; Wei, Wenjing; Aitken, Samuel L; Musick, William L; Roux, Ryan K; Garey, Kevin W

    2015-10-01

    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.

  17. 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

  18. 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

  19. 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.

  20. Optimal control of an influenza model with seasonal forcing and age-dependent transmission rates.

    PubMed

    Lee, Jeehyun; Kim, Jungeun; Kwon, Hee-Dae

    2013-01-21

    This study considers an optimal intervention strategy for influenza outbreaks. Variations in the SEIAR model are considered to include seasonal forcing and age structure, and control strategies include vaccination, antiviral treatment, and social distancing such as school closures. We formulate an optimal control problem by minimizing the incidence of influenza outbreaks while considering intervention costs. We examine the effects of delays in vaccine production, seasonal forcing, and age-dependent transmission rates on the optimal control and suggest some optimal strategies through numerical simulations.

  1. Interpretation and expectation in childhood anxiety disorders: age effects and social specificity.

    PubMed

    Creswell, Cathy; Murray, Lynne; Cooper, Peter

    2014-01-01

    Theory and treatment for childhood anxiety disorders typically implicates children's negative cognitions, yet little is known about the characteristics of thinking styles of clinically anxious children. In particular, it is unclear whether differences in thinking styles between children with anxiety disorders and non-anxious children vary as a function of child age, whether particular cognitive distortions are associated with childhood anxiety disorders at different child ages, and whether cognitive content is disorder-specific. The current study addressed these questions among 120 7-12 year old children (53% female) who met diagnostic criteria for social anxiety disorder, other anxiety disorder, or who were not currently anxious. Contrary to expectations, threat interpretation was not inflated amongst anxious compared to non-anxious children at any age, although older (10-12 year old) anxious children did differ from non-anxious children on measures of perceived coping. The notion of cognitive-content specificity was not supported across the age-range. The findings challenge current treatment models of childhood anxiety, and suggest that a focus on changing anxious children's cognitions is not warranted in mid-childhood, and in late childhood cognitive approaches may be better focussed on promoting children's perceptions of control rather than challenging threat interpretations.

  2. Specific protein changes contribute to the differential muscle mass loss during ageing.

    PubMed

    Capitanio, Daniele; Vasso, Michele; De Palma, Sara; Fania, Chiara; Torretta, Enrica; Cammarata, Francesco P; Magnaghi, Valerio; Procacci, Patrizia; Gelfi, Cecilia

    2016-02-01

    In the skeletal muscle, the ageing process is characterized by a loss of muscle mass and strength, coupled with a decline of mitochondrial function and a decrease of satellite cells. This profile is more pronounced in hindlimb than in forelimb muscles, both in humans and in rodents. Utilizing light and electron microscopy, myosin heavy chain isoform distribution, proteomic analysis by 2D-DIGE, MALDI-TOF MS and quantitative immunoblotting, this study analyzes the protein levels and the nuclear localization of specific molecules, which can contribute to a preferential muscle loss. Our results identify the molecular changes in the hindlimb (gastrocnemius) and forelimb (triceps) muscles during ageing in rats (3- and 22-month-old). Specifically, the oxidative metabolism contributes to tissue homeostasis in triceps, whereas respiratory chain disruption and oxidative-stress-induced damage imbalance the homeostasis in gastrocnemius muscle. High levels of dihydrolipoyllysine-residue acetyltransferase (Dlat) and ATP synthase subunit alpha (Atp5a1) are detected in triceps and gastrocnemius, respectively. Interestingly, in triceps, both molecules are increased in the nucleus in aged rats and are associated to an increased protein acetylation and myoglobin availability. Furthermore, autophagy is retained in triceps whereas an enhanced fusion, decrement of mitophagy and of regenerative potential is observed in aged gastrocnemius muscle.

  3. Assessment of ganglioside age-related and topographic specificity in human brain by Orbitrap mass spectrometry.

    PubMed

    Sarbu, Mirela; Dehelean, Liana; Munteanu, Cristian V A; Vukelić, Željka; Zamfir, Alina D

    2017-03-15

    The gangliosides (GGs) of the central nervous system (CNS) exhibit age and topographic specificity and these patterns may correlate with the functions and pathologies of the brain regions. Here, chloroform extraction, nanoelectrospray (nanoESI) negative ionization, together with Orbitrap high resolution mass spectrometry (MS) determined the topographic and age-related GG specificity in normal adult human brain. Mapping of GG mixtures extracted from 20 to 82 year old frontal and occipital lobes revealed besides a decrease in the GG number with age, a variability of sialylation degree within the brain regions. From the 111 species identified, 105 were distinguished in the FL20, 74 in OL20, 46 in FL82 and 56 in OL82. The results emphasize that within the juvenile brain, GG species exhibit a higher expression in the FL than in OL, while in the aged brain the number of GG species is higher in the OL. By applying MS/MS analysis, the generated fragment ions confirmed the incidence of GT1c (d18:1/18:0) and GT1c (d18:1/20:0) in the investigated samples. The present findings are of major value for further clinical studies carried out using Orbitrap MS in order to correlate gangliosides with CNS disorders.

  4. Evolution of the rate of biological aging using a phenotype based computational model.

    PubMed

    Kittas, Aristotelis

    2010-10-07

    In this work I introduce a simple model to study how natural selection acts upon aging, which focuses on the viability of each individual. It is able to reproduce the Gompertz law of mortality and can make predictions about the relation between the level of mutation rates (beneficial/deleterious/neutral), age at reproductive maturity and the degree of biological aging. With no mutations, a population with low age at reproductive maturity R stabilizes at higher density values, while with mutations it reaches its maximum density, because even for large pre-reproductive periods each individual evolves to survive to maturity. Species with very short pre-reproductive periods can only tolerate a small number of detrimental mutations. The probabilities of detrimental (P(d)) or beneficial (P(b)) mutations are demonstrated to greatly affect the process. High absolute values produce peaks in the viability of the population over time. Mutations combined with low selection pressure move the system towards weaker phenotypes. For low values in the ratio P(d)/P(b), the speed at which aging occurs is almost independent of R, while higher values favor significantly species with high R. The value of R is critical to whether the population survives or dies out. The aging rate is controlled by P(d) and P(b) and the amount of the viability of each individual is modified, with neutral mutations allowing the system more "room" to evolve. The process of aging in this simple model is revealed to be fairly complex, yielding a rich variety of results.

  5. Impact of Age and Myopia on the Rate of Visual Field Progression in Glaucoma Patients.

    PubMed

    Park, Hae-Young Lopilly; Hong, Kyung Euy; Park, Chan Kee

    2016-05-01

    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 change in the VF only in

  6. 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.

  7. 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

  8. Specific growth rate and substrate dependent polyhydroxybutyrate production in Saccharomyces cerevisiae.

    PubMed

    Kocharin, Kanokarn; Nielsen, Jens

    2013-03-21

    Production of the biopolymer polyhydroxybutyrate (PHB) in Saccharomyces cerevisiae starts at the end of exponential phase particularly when the specific growth rate is decreased due to the depletion of glucose in the medium. The specific growth rate and the type of carbon source (fermentable/non-fermentable) have been known to influence the cell physiology and hence affect the fermentability of S. cerevisiae. The production of PHB utilizes cytosolic acetyl-CoA as a precursor and the S. cerevisiae employed in this study is therefore a strain with the enhanced cytosolic acetyl-CoA supply. Growth and PHB production at different specific growth rates were evaluated on glucose, ethanol and a mixture of glucose and ethanol as carbon source. Ethanol as carbon source yielded a higher PHB production compared to glucose since it can be directly used for cytosolic acetyl-CoA production and hence serves as a precursor for PHB production. However, this carbon source results in lower biomass yield and hence it was found that to ensure both biomass formation and PHB production a mixture of glucose and ethanol was optimal, and this resulted in the highest volumetric productivity of PHB, 8.23 mg/L · h-1, at a dilution rate of 0.1 h-1.

  9. 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

  10. Handling Age Specification in the SNOMED CT to ICD-10-CM Cross-map

    PubMed Central

    Xu, Junchuan; Fung, Kin Wah

    2012-01-01

    A SNOMED CT-encoded problem list will be required to satisfy the Certification Criteria for Stage 2 “Meaningful Use” of the EHR incentive program. ICD-10-CM will be replacing ICD-9-CM as the reimbursement code set in the near future. Having a cross-map from SNOMED CT to ICD-10-CM will promote the use of SNOMED CT as the primary problem list terminology, while easing the transition to ICD-10-CM. This rule-based map will support semi-automatic generation of ICD-10-CM codes from SNOMED CT-encoded data. Among the different types of rules, the age rule is used to handle age-specific code assignment in ICD-10-CM. To supplement the manual process of creation of age rules, a special QA process was implemented to flag maps that were potentially missing age rules. The QA flagged 342 concepts for review (out of 7,277), of which 172 concepts (50.3%) were true positives. Without the special QA, many of the age rules would have been missed. PMID:23304377

  11. 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

  12. A software system to collect expert relevance ratings of medical record items for specific clinical tasks.

    PubMed

    Harvey, H Benjamin; Krishnaraj, Arun; Alkasab, Tarik K

    2014-02-28

    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.

  13. 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

  14. 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

  15. Do age-specific survival patterns of wild boar fit current evolutionary theories of senescence?

    PubMed

    Gamelon, Marlène; Focardi, Stefano; Gaillard, Jean-Michel; Gimenez, Olivier; Bonenfant, Christophe; Franzetti, Barbara; Choquet, Rémi; Ronchi, Francesca; Baubet, Eric; Lemaître, Jean-François

    2014-12-01

    Actuarial senescence is widespread in age-structured populations. In growing populations, the progressive decline of Hamiltonian forces of selection with age leads to decreasing survival. As actuarial senescence is overcompensated by a high fertility, actuarial senescence should be more intense in species with high reproductive effort, a theoretical prediction that has not been yet explicitly tested across species. Wild boar (Sus scrofa) females have an unusual life-history strategy among large mammals by associating both early and high reproductive effort with potentially long lifespan. Therefore, wild boar females should show stronger actuarial senescence than similar-sized related mammals. Moreover, being polygynous and much larger than females, males should display higher senescence rates than females. Using a long-term monitoring (18 years) of a wild boar population, we tested these predictions. We provided clear evidence of actuarial senescence in both sexes. Wild boar females had earlier but not stronger actuarial senescence than similar-sized ungulates. Both sexes displayed similar senescence rates. Our study indicates that the timing of senescence, not the rate, is associated with the magnitude of fertility in ungulates. This demonstrates the importance of including the timing of senescence in addition to its rate to understand variation in senescence patterns in wild populations.

  16. The research on aging failure rate and optimization estimation of protective relay under haze conditions

    NASA Astrophysics Data System (ADS)

    Wang, Ying-kang; Zhou, Meng-ran; Yang, Jie; Zhou, Pei-qiang; Xie, Ying

    2017-01-01

    In the fog and haze, the air contains large amounts of H2S, SO2, SO3 and other acids, air conductivity is greatly improved, the relative humidity is also greatly increased, Power transmission lines and electrical equipment in such an environment will increase in the long-running failure ratedecrease the sensitivity of the detection equipment, impact protection device reliability. Weibull distribution is widely used in component failure distribution fitting. It proposes a protection device aging failure rate estimation method based on the least squares method and the iterative method,.Combined with a regional power grid statistics, computing protective equipment failure rate function. Binding characteristics of electrical equipment operation status under haze conditions, optimization methods, get more in line with aging protection equipment failure under conditions of haze characteristics.

  17. 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.

  18. 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.

  19. Heart rate recovery in elite athletes: the impact of age and exercise capacity.

    PubMed

    Suzic Lazic, Jelena; Dekleva, Milica; Soldatovic, Ivan; Leischik, Roman; Suzic, Slavica; Radovanovic, Dragan; Djuric, Biljana; Nesic, Dejan; Lazic, Milivoje; Mazic, Sanja

    2017-03-01

    There is compelling evidence that postexercise heart rate recovery (HRR) is a valid indicator of sympaticovagal balance. It is also used in prescription and monitoring of athletic training. The purpose of our study was to determine HRR after maximal exercise among elite athletes with respect to age. A total of 274 elite male Caucasian athletes were randomly selected from the larger sample and divided into two groups: adolescent (group Y) and adult athletes (≥18 years; group A). They performed maximal cardiopulmonary exercise testing on a treadmill. Heart rate recovery was calculated as the rate of decline of HR from peak exercise to rates 1, 2 and 3 min after cessation of exercise (HRR1, HRR2 and HRR3). A significantly higher HRR1 was found in group A (29·5 ± 15·6 versus 22·4 ± 10·8, P<0·001), but HRR3 was higher in group Y (82·7 ± 10·2 versus 79·9 ± 12·25; P = 0·04). Stepwise multivariate linear regression analysis showed that, among all subjects, the HRR1 alone was independently associated with age (P<0·001). The maximal oxygen consumption (VO2 max) was in a negative relationship with HRR1 and in a positive one with HRR3 (P<0·05) with respect to all athletes. The HRR during 3 min postexercise should be reported for the purpose of better assessing functional adaptation to exercise among elite athletes as well as the age-associated differences in recovery. Higher values of HRR1 should be expected in older athletes, and HRR3 could be used as an index of aerobic capacity, irrespective of age.

  20. Apolipoprotein E and Alzheimer disease: genotype-specific risks by age and sex.

    PubMed Central

    Bickeböller, H; Campion, D; Brice, A; Amouyel, P; Hannequin, D; Didierjean, O; Penet, C; Martin, C; Pérez-Tur, J; Michon, A; Dubois, B; Ledoze, F; Thomas-Anterion, C; Pasquier, F; Puel, M; Demonet, J F; Moreaud, O; Babron, M C; Meulien, D; Guez, D; Chartier-Harlin, M C; Frebourg, T; Agid, Y; Martinez, M; Clerget-Darpoux, F

    1997-01-01

    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 epsilon3 allele, an increased risk associated with the APOE epsilon4 allele (odds ratio [OR] [epsilon4] = 2.7 with 95% confidence interval [CI] = 2.0-3.6; P < .001) and a protective effect of the APOE epsilon2 allele (OR[epsilon2] = 0.5 with 95% CI = 0.3-0.98; P = .012) were retrieved. An effect of the epsilon4 allele dosage on susceptibility was confirmed (OR[epsilon4/epsilon4] vs. the epsilon3/epsilon3 genotype = 11.2 [95% CI = 4.0-31.6]; OR[epsilon3/epsilon4] vs. the epsilon3/epsilon3 genotype = 2.2 [95% CI = 1.5-3.5]). The frequency of the epsilon4 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 epsilon4 allele versus the epsilon3 allele, OR(epsilon4), were not equal in all age classes: OR(epsilon4) 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 epsilon3/epsilon4 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. PMID:9012418

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. A comprehensive database of quality-rated fossil ages for Sahul’s Quaternary vertebrates

    NASA Astrophysics Data System (ADS)

    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.

    2016-07-01

    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.

  6. 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

  7. 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…

  8. Age-specific and sex-specific incidence of systemic lupus erythematosus: an estimate from cross-sectional claims data of 2.3 million people in the German statutory health insurance 2002

    PubMed Central

    Brinks, Ralph; Hoyer, Annika; Weber, Sergej; Fischer-Betz, Rebecca; Sander, Oliver; Richter, Jutta G; Chehab, Gamal; Schneider, Matthias

    2016-01-01

    Objective To provide an estimate of age-specific incidence rate of physician-diagnosed systemic lupus erythematosus (SLE) for German men and women. Methods The age-specific and sex-specific prevalence of diagnosed SLE in claims data is used to estimate the incidence in the German male and female population. The claims data set stems from a representative sample of the statutory health insurance in 2002 and comprises 2.3 million people. The statutory health insurance covers >85% of the German population. Results The estimated incidence rates are 0.9 (95% CI 0.7 to 1.1) per 100 000 person-years for men and 1.9 (95% CI 1.7 to 2.2) per 100 000 person-years for women. The age-specific incidence rate of SLE in the male population has a maximum of 2.2 (95% CI 1.0 to 3.4) per 100 000 person-years at the age of 65–70 years. In women, the incidence is peaking at the rate of 3.6 (95% CI 2.9 to 4.3) cases per 100 000 person-years at the age of 20–25 years, but has a second local maximum (2.6, 95% CI 1.5 to 3.8) at menopausal age. Conclusions For the first time, representative data on the incidence of SLE in Germany are provided. The estimated incidence rates of SLE for men and women in Germany are at the lower end of other estimates from comparable European countries. PMID:27933200

  9. 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.

  10. Speech evoked cortical potentials: effects of age and stimulus presentation rate.

    PubMed

    Tremblay, Kelly L; Billings, Curtis; Rohila, Neeru

    2004-03-01

    We examined the effects of stimulus complexity and stimulus presentation rate in ten younger and ten older normal-hearing adults. A 1 kHz tone burst as well as a speech syllable were used to elicit the N1 -P2 complex. Three different interstimulus intervals (ISI) were used (510, 910, and 1510 msec). When stimuli were presented at the medium presentation rate (910 msec ISI), N1 and P2 latencies were prolonged for older listeners in response to the speech stimulus but not the tone stimulus. These age effects were absent when stimuli were presented at a slower rate (1510 msec ISI). Results from this study suggest that rapidly occurring stimulus onsets, either within a stimulus or between stimuli, result in prolonged N1 and P2 responses in older adults. This is especially true when processing complex stimuli such as speech. One potential explanation for this age effect might be age-related refractory differences in younger and older auditory systems. Refractory issues might in turn affect synchronized neural activity underlying the perception of critical time-varying speech cues and may partially explain some of the difficulties older people experience understanding speech.

  11. 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.

  12. 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.

  13. Using the BASC-2 Parent Rating Scales to Screen for Autism Spectrum Disorder in Toddlers and Preschool-Aged Children.

    PubMed

    Bradstreet, Lauren E; Juechter, Julia I; Kamphaus, Randy W; Kerns, Connor M; Robins, Diana L

    2017-02-01

    Early identification of toddlers and preschool-aged children with autism spectrum disorder (ASD) is important for ensuring that these youth receive targeted early intervention services. Identifying young children with ASD is complicated by overlap among symptoms of ASD and other developmental delays. Additionally, youth with ASD have a higher risk of experiencing co-occurring challenging behaviors that are beyond the diagnostic criteria for ASD (e.g., attention difficulties, anxiety). Given this, broadband behavioral assessments that measure symptoms of ASD as well as other behavioral and emotional challenges offer a cost-effective method for screening young children. The present study evaluated the utility of one such assessment, the Behavior Assessment System for Children, Second Edition, Parent Rating Scale-Preschool (BASC-2 PRS-P), for identifying young children with ASD from those with other diagnoses (including other developmental delays) and those without diagnoses. The sample included 224 toddlers and preschoolers (age range: 24-63 months, males n = 153 [68 % total sample]) who screened positive on an ASD-specific screening tool. Results demonstrated that the Developmental Social Disorders (DSD) scale on the BASC-2 PRS-P had adequate sensitivity and specificity values when distinguishing youth with ASD from those without any diagnoses, but not when differentiating between youth with ASD and those with other diagnoses. Similar to other multidimensional behavior rating scales, the BASC-2 PRS-P may be most useful for identifying young children who require comprehensive diagnostic evaluations.

  14. 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

  15. Ra isotopes in trees: Their application to the estimation of heartwood growth rates and tree ages

    NASA Astrophysics Data System (ADS)

    Hancock, Gary J.; Murray, Andrew S.; Brunskill, Gregg J.; Argent, Robert M.

    2006-12-01

    The difficulty in estimating growth rates and ages of tropical and warm-temperate tree species is well known. However, this information has many important environmental applications, including the proper management of native forests and calculating uptake and release of atmospheric carbon. We report the activities of Ra isotopes in the heartwood, sapwood and leaves of six tree species, and use the radial distribution of the 228Ra/226Ra activity ratio in the stem of the tree to estimate the rate of accretion of heartwood. A model is presented in which dissolved Ra in groundwater is taken up by tree roots, translocated to sapwood in a chemically mobile (ion-exchangeable) form, and rendered immobile as it is transferred to heartwood. Uptake of 232Th and 230Th (the parents of 228Ra and 226Ra) is negligible. The rate of heartwood accretion is determined from the radioactive decay of 228Ra (half-life 5.8 years) relative to long-lived 226Ra (half-life 1600 years), and is relevant to growth periods of up to 50 years. By extrapolating the heartwood accretion rate to the entire tree ring record the method also appears to provide realistic estimates of tree age. Eight trees were studied (three of known age, 72, 66 and 35 years), including three Australian hardwood eucalypt species, two mangrove species, and a softwood pine (P. radiata). The method indicates that the rate of growth ring formation is species and climate dependent, varying from 0.7 rings yr-1 for a river red gum (E. camaldulensis) to around 3 rings yr-1 for a tropical mangrove (X. mekongensis).

  16. 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

  17. The Rate of Nonallelic Homologous Recombination in Males Is Highly Variable, Correlated between Monozygotic Twins and Independent of Age

    PubMed Central

    MacArthur, Jacqueline A. L.; Spector, Timothy D.; Lindsay, Sarah J.; Mangino, Massimo; Gill, Raj; Small, Kerrin S.; Hurles, Matthew E.

    2014-01-01

    Nonallelic homologous recombination (NAHR) between highly similar duplicated sequences generates chromosomal deletions, duplications and inversions, which can cause diverse genetic disorders. Little is known about interindividual variation in NAHR rates and the factors that influence this. We estimated the rate of deletion at the CMT1A-REP NAHR hotspot in sperm DNA from 34 male donors, including 16 monozygotic (MZ) co-twins (8 twin pairs) aged 24 to 67 years old. The average NAHR rate was 3.5×10−5 with a seven-fold variation across individuals. Despite good statistical power to detect even a subtle correlation, we observed no relationship between age of unrelated individuals and the rate of NAHR in their sperm, likely reflecting the meiotic-specific origin of these events. We then estimated the heritability of deletion rate by calculating the intraclass correlation (ICC) within MZ co-twins, revealing a significant correlation between MZ co-twins (ICC = 0.784, p = 0.0039), with MZ co-twins being significantly more correlated than unrelated pairs. We showed that this heritability cannot be explained by variation in PRDM9, a known regulator of NAHR, or variation within the NAHR hotspot itself. We also did not detect any correlation between Body Mass Index (BMI), smoking status or alcohol intake and rate of NAHR. Our results suggest that other, as yet unidentified, genetic or environmental factors play a significant role in the regulation of NAHR and are responsible for the extensive variation in the population for the probability of fathering a child with a genomic disorder resulting from a pathogenic deletion. PMID:24603440

  18. State-Specific Rates of Primary and Secondary Syphilis Among Men Who Have Sex with Men - United States, 2015.

    PubMed

    de Voux, Alex; Kidd, Sarah; Grey, Jeremy A; Rosenberg, Eli S; Gift, Thomas L; Weinstock, Hillard; Bernstein, Kyle T

    2017-04-07

    In 2015, the rate of reported primary and secondary syphilis in the United States was 7.5 cases per 100,000 population, nearly four times the previous lowest documented rate of 2.1 in 2000 (1). In 2015, 81.7% of male primary and secondary syphilis cases with information on the sex of the sex partner were among gay, bisexual, and other men who have sex with men (collectively referred to as MSM) (1). These data suggest a disproportionate incidence of disease among MSM. However, attempts to quantify this disparity have been hindered by limited data on the size of the MSM population at the state level. To produce the first estimates of state-specific rates of primary and secondary syphilis among MSM, CDC used MSM population estimates based on a new methodology (2) and primary and secondary syphilis case counts reported in 2015 to the National Notifiable Diseases Surveillance System. Among 44 states reporting information on the sex of sex partners for ≥70% of male cases, the overall rate of primary and secondary syphilis among all men (aged ≥18 years) in the United States in 2015 was 17.5 per 100,000, compared with 309.0 among MSM and 2.9 among men who reported sex with women only. The overall rate of primary and secondary syphilis among MSM was 106.0 times the rate among men who have sex with women only and 167.5 times the rate among women.* These data highlight the disproportionate impact of syphilis among MSM and underscore the need for innovative and targeted syphilis prevention measures at the state and local level, especially among MSM. It is important that health care providers recognize the signs and symptoms of syphilis, screen sexually active MSM for syphilis at least annually, and provide timely treatment according to national sexually transmitted diseases treatment guidelines (3).

  19. Age- and sex-specific causal effects of adiposity on cardiovascular risk factors.

    PubMed

    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; Ingelsson, Erik

    2015-05-01

    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.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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

  5. The Gifted Rating Scales-School Form: A Validation Study Based on Age, Gender, and Race

    PubMed Central

    Pfeiffer, Steven I.; Petscher, Yaacov; Kumtepe, Alper

    2015-01-01

    This study examined the internal consistency and validity of a new rating scale to identify gifted students, the Gifted Rating Scales-School Form (GRS-S). The study explored the effect of gender, race/ethnicity, age, and rater familiarity on GRS-S ratings. One hundred twenty-two students in first to eighth grade from elementary and middle schools in the southeastern United States participated in the investigation. Results indicated high internal consistency for the six GRS-S scales: Intellectual Ability, Academic Ability, Creativity, Artistic Talent, Leadership, and Motivation. Results revealed no effect of race/ethnicity, age, or rater familiarity with the student. There was no significant effect for gender, although a trend was noted for girls rated slightly higher than boys across all scales. This trend was consistent with analyses of the standardization data and with cross-cultural findings using translated versions of the GRS-S. The present findings provided support for the GRS-S as a valid gifted screening instrument. PMID:26366036

  6. 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.

  7. Modeling and prediction of HIV in China: transmission rates structured by infection ages.

    PubMed

    Zhou, Yican; Shao, Yiming; Ruan, Yuhua; Xu, Jianqing; Ma, Zhien; Mei, Changlin; Wu, Jianhong

    2008-04-01

    HIV transmission process involves a long incubation and infection period, and the transmission rate varies greatly with infection stage. Consequently, modeling analysis based on the assumption of a constant transmission rate during the entire infection period yields an inaccurate description of HIV transmission dynamics and long-term projections. Here we develop a general framework of mathematical modeling that takes into account this heterogeneity of transmission rate and permits rigorous estimation of important parameters using a regression analysis of the twenty-year reported HIV infection data in China. Despite the large variation in this statistical data attributable to the knowledge of HIV, surveillance efforts, and uncertain events, and although the reported data counts individuals who might have been infected many years ago, our analysis shows that the model structured on infection age can assist us in extracting from this data set very useful information about transmission trends and about effectiveness of various control measures.

  8. 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.

  9. 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.

  10. 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

  11. Age-of-acquisition ratings for 30,000 English words.

    PubMed

    Kuperman, Victor; Stadthagen-Gonzalez, Hans; Brysbaert, Marc

    2012-12-01

    We present age-of-acquisition (AoA) ratings for 30,121 English content words (nouns, verbs, and adjectives). For data collection, this megastudy used the Web-based crowdsourcing technology offered by the Amazon Mechanical Turk. Our data indicate that the ratings collected in this way are as valid and reliable as those collected in laboratory conditions (the correlation between our ratings and those collected in the lab from U.S. students reached .93 for a subsample of 2,500 monosyllabic words). We also show that our AoA ratings explain a substantial percentage of the variance in the lexical-decision data of the English Lexicon Project, over and above the effects of log frequency, word length, and similarity to other words. This is true not only for the lemmas used in our rating study, but also for their inflected forms. We further discuss the relationships of AoA with other predictors of word recognition and illustrate the utility of AoA ratings for research on vocabulary growth.

  12. Age-, gender-, and socioeconomic status-specific incidence of Parkinson's disease and parkinsonism in northeast Scotland: the PINE study.

    PubMed

    Caslake, Robert; Taylor, Kate; Scott, Neil; Gordon, Joanna; Harris, Clare; Wilde, Katie; Murray, Alison; Counsell, Carl

    2013-05-01

    There have been few high quality incidence studies of Parkinson's disease (PD). We measured age-, gender- and socioeconomic-specific incidence rates for parkinsonism and PD in north-east Scotland, and compared our results with those of previous high quality studies. Incident patients were identified prospectively over three years by several overlapping methods from primary care practices (total population 311,357). Parkinsonism was diagnosed if patients had two or more cardinal motor signs. Drug-induced parkinsonism was excluded. Patients had yearly follow-up to improve diagnostic accuracy. Incidence rates using clinical diagnosis at latest follow-up were calculated for all parkinsonism and for PD by age, gender and socioeconomic status. Meta-analysis with similar studies was performed. Of 377 patients identified at baseline with possible or probable parkinsonism, 363 were confirmed as incident patients after median follow-up of 26 months (mean age 74.8 years, SD 9.8; 61% men). The crude annual incidence of parkinsonism was 28.7 per 100,000 (95% confidence interval (CI) 25.7-31.8) and PD 17.9 per 100,000 (95% CI 15.5-20.4). PD was more common in men (age-adjusted male to female ratio 1.87:1, 95% CI 1.55-2.23) but there was no difference by socioeconomic status. Meta-analysis of 12 studies showed an incidence of PD (adjusted to the 1990 Scottish population) of 14.6 per 100,000 (95% CI 12.2-17.3) with considerable heterogeneity (I(2) 95%), partially explained by population size and recruitment duration. The incidence of PD was similar to other high quality studies. The incidence of PD was not affected by socioeconomic status.

  13. 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.

  14. General and URTI-specific antibiotic prescription rates in a Malaysian primary care setting.

    PubMed

    Teng, C L; Achike, F I; Phua, K L; Norhayati, Y; Nurjahan, M I; Nor, A H; Koh, C N

    2004-11-01

    Antibiotic prescribing by primary care doctors has received renewed interest due to the continuing emergence of antibiotic resistance and the attendant cost to healthcare. We examined the antibiotic prescribing rate in relation to selected socio-demographic characteristics of the prescribers at the Seremban Health Clinic, a large public primary care clinic, designated for teaching, in the state of Negeri Sembilan, Malaysia. Data were obtained from: (1) retrospective review of prescriptions for the month of June 2002 and (2) a questionnaire survey of prescribers. A total of 10667 prescriptions were reviewed. The overall antibiotic prescribing rate was 15%; the rate (16%) was higher for the general Outpatient Department (OPD) than the 3% for the Maternal & Child Health Clinic (MCH). The antibiotic prescription rates for upper respiratory tract infection (URTI) were 26% and 16%, respectively, for the OPD and MCH. Half of all the antibiotic prescriptions were for URTI making prescribing for URTI an appropriate target for educational intervention. The URTI-specific antibiotic prescription rate did not correlate with the prescribers' intention to specialise, patient load, perceived patient's expectation for an antibiotic, or the score for knowledge of streptococcal tonsillitis. Prescribing behaviours and record-keeping practices requiring correction were identified.

  15. Multi-item direct behavior ratings: Dependability of two levels of assessment specificity.

    PubMed

    Volpe, Robert J; Briesch, Amy M

    2015-09-01

    Direct Behavior Rating-Multi-Item Scales (DBR-MIS) have been developed as formative measures of behavioral assessment for use in school-based problem-solving models. Initial research has examined the dependability of composite scores generated by summing all items comprising the scales. However, it has been argued that DBR-MIS may offer assessment of 2 levels of behavioral specificity (i.e., item-level, global composite-level). Further, it has been argued that scales can be individualized for each student to improve efficiency without sacrificing technical characteristics. The current study examines the dependability of 5 items comprising a DBR-MIS designed to measure classroom disruptive behavior. A series of generalizability theory and decision studies were conducted to examine the dependability of each item (calls out, noisy, clowns around, talks to classmates and out of seat), as well as a 3-item composite that was individualized for each student. Seven graduate students rated the behavior of 9 middle-school students on each item over 3 occasions. Ratings were based on 10-min video clips of students during mathematics instruction. Separate generalizability and decision studies were conducted for each item and for a 3-item composite that was individualized for each student based on the highest rated items on the first rating occasion. Findings indicate favorable dependability estimates for 3 of the 5 items and exceptional dependability estimates for the individualized composite.

  16. 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

  17. 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.

  18. 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

  19. Site specific rates of mitochondrial genomes and the phylogeny of eutheria

    PubMed Central

    Kjer, Karl M; Honeycutt, Rodney L

    2007-01-01

    Background Traditionally, most studies employing data from whole mitochondrial genomes to diagnose relationships among the major lineages of mammals have attempted to exclude regions that potentially complicate phylogenetic analysis. Components generally excluded are 3rd codon positions of protein-encoding genes, the control region, rRNAs, tRNAs, and the ND6 gene (encoded on the opposite strand). We present an approach that includes all the data, with the exception of the control region. This approach is based on a site-specific rate model that accommodates excessive homoplasy and that utilizes secondary structure as a reference for proper alignment of rRNAs and tRNAs. Results Mitochondrial genomic data for 78 eutherian mammals, 8 metatherians, and 3 monotremes were analyzed with a Bayesian analysis and our site specific rate model. The resultant phylogeny revealed strong support for most nodes and was highly congruent with more recent phylogenies based on nuclear DNA sequences. In addition, many of the conflicting relationships observed by earlier mitochondrial-based analyses were resolved without need for the exclusion of large subsets of the data. Conclusion Rather than exclusion of data to minimize presumed noise associated with non-protein encoding genes in the mitochondrial genome, our results indicate that selection of an appropriate model that accommodates rate heterogeneity across data partitions and proper treatment of RNA genes can result in a mitochondrial genome-based phylogeny of eutherian mammals that is reasonably congruent with recent phylogenies derived from nuclear genes. PMID:17254354

  20. Identification of UK sickness certification rates, standardised for age and sex

    PubMed Central

    Wynne-Jones, Gwenllian; Mallen, Christian D; Mottram, Sara; Main, Chris J; Dunn, Kate M

    2009-01-01

    Background There is growing interest in tackling the perceived ‘sick note’ culture in the UK. Aim The aim of this paper was to report the rates of sickness certification in a UK population, using sick certification rates as a precursor to addressing fitness for work. Method Electronic records from all 14 practices included in the Keele GP Research Network were reviewed; all sickness certification records from 2005 were retrieved and corresponding consultation records were examined. Participants were 148 176 patients registered during 2005, including 6398 patients who received at least one sickness certificate during the same year. Results The rate of sickness certification was 101.67 certificates per 1000 person years (95% confidence interval [CI] = 100.13 to 103.21). This rate was significantly higher in women, at 109.76 certificates per 1000 person years (95% CI = 107.550 to 112.02), compared to men who had a rate of 93.68 certificates per 1000 person years (95% CI = 91.59 to 95.78; P<0.001). The rate of sickness certification was greatest for mental health conditions, followed closely by musculoskeletal conditions. Conclusion On average, one in 10 patients will receive a sickness certificate each year, with the highest rates occurring around 50 years of age, in women. Mental health and musculoskeletal conditions were associated with the highest rates of certification. These results provide important information to underpin the national ‘Fit for Work’ scheme, by providing targets for intervention and a benchmark against which the impact of public health initiatives to reduce certified sickness absence due to health conditions can be evaluated and monitored. PMID:19566999

  1. Capturing Age-group Differences and Developmental Change with the BASC Parent Rating Scales

    PubMed Central

    Barbot, Baptiste; Hein, Sascha; Luthar, Suniya S.; Grigorenko, Elena L.

    2014-01-01

    Estimation of age-group differences and intra-individual change across distinct developmental periods is often challenged by the use of age-appropriate (but non-parallel) measures. We present a short version of the Behavior Assessment System (Reynolds & Kamphaus, 1998), Parent Rating Scales for Children (PRS-C) and Adolescents (PRS-A), which uses only their common-items to derive estimates of the initial constructs optimized for developmental studies. Measurement invariance of a three-factor model (Externalizing, Internalizing, Adaptive Skills) was tested across age-groups (161 mothers using PRS-C; 200 mothers using PRS-A) and over time (115 mothers using PRS-C at baseline and PRS-A five years later) with the original versus short PRS. Results indicated that the short PRS holds a sufficient level of invariance for a robust estimation of age-group differences and intra-individual change, as compared to the original PRS, which held only weak invariance leading to flawed developmental inferences. Importance of test-content parallelism for developmental studies is discussed. PMID:25045196

  2. Age-period-cohort analysis of hepatitis A incidence rates in Korea from 2002 to 2012

    PubMed Central

    2016-01-01

    OBJECTIVES This study aimed to evaluate the epidemiology of hepatitis A in Korea from 2002 to 2012 using age-period-cohort analyses. METHODS We used claims data from the Korean National Health Insurance Corporation for the entire population. Census data from 2010 were used as the standard population. The incidence of hepatitis A was assumed to have a Poisson distribution, and the models and effects were evaluated using the intrinsic estimator method, the likelihood ratio, and the Akaike information criterion. RESULTS The incidence of hepatitis A gradually increased until 2007 (from 17.55 to 35.72 per 100,000 population) and peaked in 2009 (177.47 per 100,000 population). The highest incidence was observed among 27-29-year-old individuals when we omitted data from 2005 to 2007. From 2005 to 2007, the peak incidence was observed among 24-26-year-old individuals, followed by 27-29-year-olds. The best model fits were observed when the age-period-cohort variables were all considered at the same time for males, females, and the whole population. CONCLUSIONS The incidence of hepatitis A exhibited significant age-period-cohort effects; its incidence peaked in 2009 and was especially high among Koreans 20-39 years of age. These epidemiological patterns may help predict when high incidence rates of hepatitis A may occur in developing countries during their socioeconomic development. PMID:27703127

  3. 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.

  4. 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

  5. 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.

  6. Waterborne cues from crabs induce thicker skeletons, smaller gonads and size-specific changes in growth rate in sea urchins.

    PubMed

    Selden, Rebecca; Johnson, Amy S; Ellers, Olaf

    2009-01-01

    Indirect predator-induced effects on growth, morphology and reproduction have been extensively studied in marine invertebrates but usually without consideration of size-specific effects and not at all in post-metamorphic echinoids. Urchins are an unusually good system, in which, to study size effects because individuals of various ages within one species span four orders of magnitude in weight while retaining a nearly isometric morphology. We tracked growth of urchins, Strongylocentrotus droebachiensis (0.013-161.385 g), in the presence or absence of waterborne cues from predatory Jonah crabs, Cancer borealis. We ran experiments at ambient temperatures, once for 4 weeks during summer and again, with a second set of urchins, for 22 weeks over winter. We used a scaled, cube-root transformation of weight for measuring size more precisely and for equalizing variance across sizes. Growth rate of the smallest urchins (summer: <17 mm diameter; winter: <7 mm diameter) decreased by 40-42% in response to crab cues. In contrast, growth rate of larger urchins was unaffected in the summer and increased in response to crab scent by 7% in the winter. At the end of the 22-week experiment, additional gonadal and skeletal variables were measured. Cue-exposed urchins developed heavier, thicker skeletons and smaller gonads, but no differences in spine length or jaw size. The differences depended on urchin size, suggesting that there are size-specific shifts in gonadal and somatic investment in urchins.

  7. The rate of meiotic gene conversion varies by sex and age

    PubMed Central

    Halldorsson, Bjarni V.; Hardarson, Marteinn T.; Kehr, Birte; Styrkarsdottir, Unnur; Gylfason, Arnaldur; Thorleifsson, Gudmar; Zink, Florian; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Sulem, Patrick; Masson, Gisli; Thorsteinsdottir, Unnur; Helgason, Agnar; Kong, Augustine; Gudbjartsson, Daniel F.; Stefansson, Kari

    2016-01-01

    Meiotic recombination involves a combination of gene conversion and crossover events that along with mutations produce germline genetic diversity. Here, we report the discovery of 3,176 SNP and 61 indel gene conversions. Our estimate of the non-crossover (NCO) gene conversion rate (G) is 7.0 for SNPs and 5.8 for indels per Mb per generation, and the GC bias is 67.6%. For indels we demonstrate a 65.6% preference for the shorter allele. NCO gene conversions from mothers are longer than those from fathers and G is 2.17 times greater in mothers. Notably, G increases with the age of mothers, but not fathers. A disproportionate number of NCO gene conversions in older mothers occur outside double strand break (DSB) regions and in regions with relatively low GC content. This points to age-related changes in the mechanisms of meiotic gene conversions in oocytes. PMID:27643539

  8. Patterns and Trends in Age-Specific Black-White Differences in Breast Cancer Incidence and Mortality - United States, 1999-2014.

    PubMed

    Richardson, Lisa C; Henley, S Jane; Miller, Jacqueline W; Massetti, Greta; Thomas, Cheryll C

    2016-10-14

    Breast cancer continues to be the most commonly diagnosed cancer and the second leading cause of cancer deaths among U.S. women (1). Compared with white women, black women historically have had lower rates of breast cancer incidence and, beginning in the 1980s, higher death rates (1). This report examines age-specific black-white disparities in breast cancer incidence during 1999-2013 and mortality during 2000-2014 in the United States using data from United States Cancer Statistics (USCS) (2). Overall rates of breast cancer incidence were similar, but death rates remained higher for black women compared with white women. During 1999-2013, breast cancer incidence decreased among white women but increased slightly among black women resulting in a similar average incidence at the end of the period. Breast cancer incidence trends differed by race and age, particularly from 1999 to 2004-2005, when rates decreased only among white women aged ≥50 years. Breast cancer death rates decreased significantly during 2000-2014, regardless of age with patterns varying by race. For women aged ≥50 years, death rates declined significantly faster among white women compared with black women; among women aged <50 years, breast cancer death rates decreased at the same rate among black and white women. Although some of molecular factors that lead to more aggressive breast cancer are known, a fuller understanding of the exact mechanisms might lead to more tailored interventions that could decrease mortality disparities. When combined with population-based approaches to increase knowledge of family history of cancer, increase physical activity, promote a healthy diet to maintain a healthy bodyweight, and increase screening for breast cancer, targeted treatment interventions could reduce racial disparities in breast cancer.

  9. 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

  10. Tissue-specific autophagy responses to aging and stress in C. elegans

    PubMed Central

    Chapin, Hannah C.; Okada, Megan; Merz, Alexey J.; Miller, Dana L.

    2015-01-01

    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. PMID:26142908

  11. 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.

  12. 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.

  13. Age-specific survival and reproductive probabilities: evidence for senescence in male fallow deer (Dama dama).

    PubMed Central

    McElligott, Alan G; Altwegg, Res; Hayden, Thomas J

    2002-01-01

    Survival and reproduction are key features in the evolution of life-history strategies. In this study, we use capture-mark-resighting and multi-state models to examine survival senescence and reproductive senescence in six successive cohorts of fallow bucks that were studied for 16 years. We found that the overall age-specific survival probabilities of males were highly variable and the best-fitting model revealed that fallow bucks have four life-history stages: yearling, pre-reproductive, prime-age and senescent. Pre-reproductive males (2 and 3 years old) had the highest survival. Survival declined sharply after the age of 9 years, indicating that senescence had begun. When we considered reproducing and non-reproducing males separately, there was no evidence of senescence in the former, and steadily decreasing survival after the onset of social maturity in the latter. Reproduction probability also declined in older males, and thus we provide very strong evidence of senescence. Reproducers had a greater chance of reproducing again in the following year than non-reproducers. Furthermore, there were differences in the survival probabilities, with reproducers consistently surviving better than non-reproducers. In our study population, reproducers allocate more to the effort to reproduce than non-reproducers. Therefore our results indicate the generally higher phenotypic quality of reproducing males. These results, along with earlier studies on the same population, could indicate positive relationships between fitness correlates. PMID:12061956

  14. 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.

  15. Methylomic Aging As a Window on Lifestyle Impact: Tobacco and Alcohol Use Alter the Rate of Biological Aging

    PubMed Central

    Beach, Steven R. H.; Dogan, Meeshanthini V.; Lei, Man-Kit; Cutrona, Carolyn E.; Gerrard, Meg; Gibbons, Frederick X.; Simons, Ronald L.; Brody, Gene H.; Philibert, Robert A.

    2016-01-01

    Objectives To examine the effect of the relationship between alcohol and cigarette consumption on biological aging using deoxyribonucleic acid (DNA) methylation-based indices. Design We examined the association between DNA methylation indices of smoking and alcohol to those for biological aging in two independent cohorts using the epigenetic “clock” provided by Hannum and colleagues. Setting Longitudinal studies of aging and the effect of psychosocial stress. Participants Publicly available genome-wide methylation data from participants in two ethnically informative cohorts (n=656 white, n=180 black). Measurements Deviation of biological age from chronological age as a result of smoking and alcohol consumption. Results Greater cigarette consumption was associated with accelerated biological aging, with strong effects evident at even low levels of exposure. In contrast, alcohol consumption was associated with a mixed effect on biological aging and pronounced nonlinear effects. At low and heavy levels of alcohol consumption, there was accelerated biological aging, whereas at intermediate levels of consumption there was a relative decelerating effect. The decelerating effects of alcohol were particularly notable at loci for which methylation increased with age. Conclusion These data support prior epidemiological studies indicating that moderate alcohol use is associated with healthy aging, but we urge caution in interpreting these results. Conversely, smoking has strong negative effects at all levels of consumption. These results also support the use of methylomic indices as a tool for assessing the impact of lifestyle on aging. PMID:26566992

  16. Accurate measurement of the specific absorption rate using a suitable adiabatic magnetothermal setup

    NASA Astrophysics Data System (ADS)

    Natividad, Eva; Castro, Miguel; Mediano, Arturo

    2008-03-01

    Accurate measurements of the specific absorption rate (SAR) of solids and fluids were obtained by a calorimetric method, using a special-purpose setup working under adiabatic conditions. Unlike in current nonadiabatic setups, the weak heat exchange with the surroundings allowed a straightforward determination of temperature increments, avoiding the usual initial-time approximations. The measurements performed on a commercial magnetite aqueous ferrofluid revealed a good reproducibility (4%). Also, the measurements on a copper sample allowed comparison between experimental and theoretical values: adiabatic conditions gave SAR values only 3% higher than the theoretical ones, while the typical nonadiabatic method underestimated SAR by 21%.

  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 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

  19. 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.

  20. Instantaneous Metabolic Cost of Walking: Joint-Space Dynamic Model with Subject-Specific Heat Rate

    PubMed Central

    Roberts, Dustyn; Hillstrom, Howard; Kim, Joo H.

    2016-01-01

    A subject-specific model of instantaneous cost of transport (ICOT) is introduced from the joint-space formulation of metabolic energy expenditure using the laws of thermodynamics and the principles of multibody system dynamics. Work and heat are formulated in generalized coordinates as functions of joint kinematic and dynamic variables. Generalized heat rates mapped from muscle energetics are estimated from experimental walking metabolic data for the whole body, including upper-body and bilateral data synchronization. Identified subject-specific energetic parameters—mass, height, (estimated) maximum oxygen uptake, and (estimated) maximum joint torques—are incorporated into the heat rate, as opposed to the traditional in vitro and subject-invariant muscle parameters. The total model metabolic energy expenditure values are within 5.7 ± 4.6% error of the measured values with strong (R2 > 0.90) inter- and intra-subject correlations. The model reliably predicts the characteristic convexity and magnitudes (0.326–0.348) of the experimental total COT (0.311–0.358) across different subjects and speeds. The ICOT as a function of time provides insights into gait energetic causes and effects (e.g., normalized comparison and sensitivity with respect to walking speed) and phase-specific COT, which are unavailable from conventional metabolic measurements or muscle models. Using the joint-space variables from commonly measured or simulated data, the models enable real-time and phase-specific evaluations of transient or non-periodic general tasks that use a range of (aerobic) energy pathway similar to that of steady-state walking. PMID:28030598

  1. 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

  2. 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…

  3. Correlations Between the Porteus Maze Test Qualitative Score and Age and Recidivism Rates of Female Correctional Inmates.

    ERIC Educational Resources Information Center

    Pearson, Virginia L.

    This study investigated correlations between the Qualitative score of the Porteus Maze Test and age and rates of recidivism of correctional institution inmates. In addition, the study was structured to provide answers to the following questions: (1) Is there a relationship between age and rates of recidivism and the Conformity-Variability score of…

  4. Scheduling Maintenance Operations Which Cause Age-Dependent Failure Rate Changes,

    DTIC Science & Technology

    1983-06-01

    ENGI.. UNCLASSIFIED B EBRAHIMIAN ET AL I JUN 83 F/G 5/1 NLmEEmmEEmmmmEE EEIhEIIhEEIII EEIIIIIIIEIIIE EIIIEIIIIIIIEE IEEIhIhEIhEIhE EIIIEEEEEIhIhE...OPERATIONS WHICH CAUSE AGE-DEPENDENT FAILURE RATE CHANGES BY BEHNAM EBRAHIMIAN AND LEONARD SHAW Prepared for Office of Naval Research Contract N00014-75-C-0858... EBRAHIMIAN AND LEONARD SHAW Prepared for Office of Naval Research Contract N00014-75-C-0858 Report No. POLY EE/CS 83-002 Polytechnic Institute of New York

  5. 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.

  6. Parameterizing age patterns of demographic rates with the multiexponential model schedule.

    PubMed

    Rogers, A; Little, J S

    1994-02-01

    "For nearly 200 years actuaries, statisticians, and demographers have sought to summarize the age pattern of mortality rates by means of a limited number of parameters. Such 'model schedules' have also been useful in representing schedules of rates other than mortality....This paper illustrates a particular general functional form for such model schedules: the multiexponential function. It discusses the changing behavior of this function as its parameters take on different values and examines the quality of the fits of this function to observed data on mortality, fertility, and migration." This is a revised version of a paper originally presented at the 1993 Annual Meeting of the Population Association of America. (SUMMARY IN FRE)

  7. A mesoscopic stochastic model for the specific consumption rate in substrate-limited microbial growth

    PubMed Central

    2017-01-01

    The specific consumption rate of substrate, as well as the associated specific growth rate, is an essential parameter in the mathematical description of substrate-limited microbial growth. In this paper we develop a completely new kinetic model of substrate transport, based on recent knowledge on the structural biology of transport proteins, which correctly describes very accurate experimental results at near-zero substrate concentration values found in the literature, where the widespread Michaelis-Menten model fails. Additionally, our model converges asymptotically to Michaelis-Menten predictions as substrate concentration increases. Instead of the single active site enzymatic reaction of Michaelis-Menten type, the proposed model assumes a multi-site kinetics, simplified as an apparent all-or-none mechanism for the transport, which is controlled by means of the local substrate concentration in the close vicinity of the transport protein. Besides, the model also assumes that this local concentration is not equal to the mean substrate concentration experimentally determined in the culture medium. Instead, we propose that it fluctuates with a mostly exponential distribution of Weibull type. PMID:28187189

  8. Biodiversity in models of cyclic dominance is preserved by heterogeneity in site-specific invasion rates

    NASA Astrophysics Data System (ADS)

    Szolnoki, Attila; Perc, Matjaž

    2016-12-01

    Global, population-wide oscillations in models of cyclic dominance may result in the collapse of biodiversity due to the accidental extinction of one species in the loop. Previous research has shown that such oscillations can emerge if the interaction network has small-world properties, and more generally, because of long-range interactions among individuals or because of mobility. But although these features are all common in nature, global oscillations are rarely observed in actual biological systems. This begets the question what is the missing ingredient that would prevent local oscillations to synchronize across the population to form global oscillations. Here we show that, although heterogeneous species-specific invasion rates fail to have a noticeable impact on species coexistence, randomness in site-specific invasion rates successfully hinders the emergence of global oscillations and thus preserves biodiversity. Our model takes into account that the environment is often not uniform but rather spatially heterogeneous, which may influence the success of microscopic dynamics locally. This prevents the synchronization of locally emerging oscillations, and ultimately results in a phenomenon where one type of randomness is used to mitigate the adverse effects of other types of randomness in the system.

  9. Biodiversity in models of cyclic dominance is preserved by heterogeneity in site-specific invasion rates

    PubMed Central

    Szolnoki, Attila; Perc, Matjaž

    2016-01-01

    Global, population-wide oscillations in models of cyclic dominance may result in the collapse of biodiversity due to the accidental extinction of one species in the loop. Previous research has shown that such oscillations can emerge if the interaction network has small-world properties, and more generally, because of long-range interactions among individuals or because of mobility. But although these features are all common in nature, global oscillations are rarely observed in actual biological systems. This begets the question what is the missing ingredient that would prevent local oscillations to synchronize across the population to form global oscillations. Here we show that, although heterogeneous species-specific invasion rates fail to have a noticeable impact on species coexistence, randomness in site-specific invasion rates successfully hinders the emergence of global oscillations and thus preserves biodiversity. Our model takes into account that the environment is often not uniform but rather spatially heterogeneous, which may influence the success of microscopic dynamics locally. This prevents the synchronization of locally emerging oscillations, and ultimately results in a phenomenon where one type of randomness is used to mitigate the adverse effects of other types of randomness in the system. PMID:27917952

  10. 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.

  11. Age- and sex-specific mortality patterns in an emerging wildlife epidemic: the phocine distemper in European harbour seals.

    PubMed

    Härkönen, Tero; Harding, Karin; Rasmussen, Thomas Dau; Teilmann, Jonas; Dietz, Rune

    2007-09-12

    Analyses of the dynamics of diseases in wild populations typically assume all individuals to be identical. However, profound effects on the long-term impact on the host population can be expected if the disease has age and sex dependent dynamics. The Phocine Distemper Virus (PDV) caused two mass mortalities in European harbour seals in 1988 and in 2002. We show the mortality patterns were highly age specific on both occasions, where young of the year and adult (>4 yrs) animals suffered extremely high mortality, and sub-adult seals (1-3 yrs) of both sexes experienced low mortality. Consequently, genetic differences cannot have played a main role explaining why some seals survived and some did not in the study region, since parents had higher mortality levels than their progeny. Furthermore, there was a conspicuous absence of animals older than 14 years among the victims in 2002, which strongly indicates that the survivors from the previous disease outbreak in 1988 had acquired and maintained immunity to PDV. These specific mortality patterns imply that contact rates and susceptibility to the disease are strongly age and sex dependent variables, underlining the need for structured epidemic models for wildlife diseases. Detailed data can thus provide crucial information about a number of vital parameters such as functional herd immunity. One of many future challenges in understanding the epidemiology of the PDV and other wildlife diseases is to reveal how immune system responses differ among animals in different stages during their life cycle. The influence of such underlying mechanisms may also explain the limited evidence for abrupt disease thresholds in wild populations.

  12. Ipsilateral coordination at preferred rate: effects of age, body side and task complexity.

    PubMed

    Van Impe, Annouchka; Coxon, James P; Goble, Daniel J; Wenderoth, Nici; Swinnen, Stephan Patrick

    2009-10-01

    Functional imaging studies have shown that elderly individuals activate widespread additional brain networks, compared to young subjects, when performing motor tasks. However, the parameters that effect this unique neural activation, including the spatial distribution of this activation across hemispheres, are still largely unknown. Here, we examined the effect of task complexity and body side on activation differences between older and younger adults while performing cyclical flexion-extension movements of the ipsilateral hand and foot. In particular, easy (isodirectional) and more difficult (non-isodirectional) coordination patterns were performed with either the left or right body side at a self-selected, comfortable rate. Even in the absence of imposed pacing the older group activated a larger brain network, suggestive of increased attentional deployment for monitoring the spatial relationships between the simultaneously moving segments and enhanced sensory processing and integration. Evidence of age-dependent underactivation was also found in contralateral M1, SMA and bilateral putamen, possibly reflecting a functional decline of the basal ganglia-mesial cortex pathway in the older group. An ANOVA model revealed significant main effects of task complexity and body side. However the interaction of these factors with age did not reach significance. Consequently, we conclude that under self-paced conditions, task complexity and body side did not have a modulatory effect on age-related brain activation.

  13. Electroencephalogram and heart rate measures of working memory at 5 and 10 months of age.

    PubMed

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

    2012-07-01

    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 electrode pairs) at both ages. WM-related decreases in HR were only present at 5 months, and WM-related increases in EEG coherence became more localized by 10 months. Regression analyses revealed that baseline-to-task changes in psychophysiology accounted for variability in WM performance at 10 but not 5 months. HR and EEG power (medial frontal and lateral frontal electrodes) were unique predictors of variability in 10-month WM performance. These findings are discussed in relation to frontal lobe development and represent the first comprehensive longitudinal analysis of age-related changes in the behavioral and psychophysiological correlates of WM.

  14. Do cognitive interventions alter the rate of age-related cognitive change?

    PubMed Central

    Salthouse, Timothy A.

    2015-01-01

    There has recently been a great deal of interest in cognitive interventions, particularly when applied in older adults with the goal of slowing or reversing age-related cognitive decline. Although seldom directly investigated, one of the fundamental questions concerning interventions is whether the intervention alters the rate of cognitive change, or affects the level of certain cognitive measures with no effect on the trajectory of change. This question was investigated with a very simple intervention consisting of the performance of three versions (treatment) or one version (control) of the relevant cognitive tests at an initial occasion. Participants were retested at intervals ranging from less than 1 to 12 years, which allowed rates of change to be examined in the control and treatment groups. Although the intervention can be considered modest, participants in the treatment group had about .25 standard deviations less negative cognitive change over an interval of approximately three years than those in the control group, which is comparable to effect sizes reported with more intensive interventions. However, there were no interactions of the intervention with length of the interval between occasions, and thus there was no evidence that the intervention affected the course of age-related cognitive decline. PMID:26478640

  15. 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.

  16. 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.

  17. 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

  18. Mutation and mutation rates at Y chromosome specific Short Tandem Repeat Polymorphisms (STRs): a reappraisal.

    PubMed

    Pinto, Nádia; Gusmão, Leonor; Amorim, António

    2014-03-01

    Mutation is a topic of intense research and raises important problems in forensics. Since the markers of choice in current forensic genetics analyses are microsatellites or Short Tandem Repeat Polymorphisms (STRs), mutation is sufficiently common to cause difficulties in evaluating DNA evidence in a significant proportion of cases but at the same time rare enough to turn the estimation of the corresponding probability of occurrence into a hard task. We address these issues using the simplest model of transmission: the Y chromosome specific STRs. Within this model, and under an explicit set of definitions and involved assumptions, we developed the theoretical framework required for the study of allelic transitions in gametogenesis, identifying the required parameters and associated probabilities and finally we discuss the estimation of these parameters and their application in forensics. We conclude that (i) for forensic casework the relevant parameter for incorporation in a likelihood ratio is biallelic specific (i.e. the mutation rate estimate corresponds to the probability of the specific allelic transition observed) and (ii) for these estimates as well as in order to provide data for testing mutation models the absolute frequency of mutated and non-mutated transmissions per allele, along with the description of the observed mutations should be reported.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. [Age-related dynamics of roach infection rate with Ligula intestinalis (Cestoda: Ligulidae) plerocercoids and probability of its usage for the calculation of host death rate].

    PubMed

    Pronin, N M; Pronina, S V

    2014-01-01

    Results of special parasitological dissections of roach samples from catches with the same fishing gear and at the same station (Monakhovo Cove, Chivyrkui Bay of the Lake Baikal) and at the same time in different years (1998-2002) are given. Stability of age-related dynamics of roach infection rate with Ligula intestinalisis in different years with the maximum of prevalence and mean abundance in fish of 3+ age, and the following sharp decrease in these rates in elder age groups, was revealed. Basing on prevalence decreasing of a single roach generation, the rate of fish mortality during its growth from age group 3+ to 4+ was estimated as 15.9-20.7%.

  5. The Effects of Age, Adiposity, and Physical Activity on the Risk of Seven Site-Specific Fractures in Postmenopausal Women.

    PubMed

    Lacombe, Jason; Cairns, Benjamin J; Green, Jane; Reeves, Gillian K; Beral, Valerie; Armstrong, Miranda Eg

    2016-08-01

    Risk factors for fracture of the neck of the femur are relatively well established, but those for fracture at other sites are little studied. In this large population study we explore the role of age, body mass index (BMI), and physical activity on the risk of fracture at seven sites in postmenopausal women. As part of the Million Women Study, 1,154,821 postmenopausal UK women with a mean age of 56.0 (SD 4.8) years provided health and lifestyle data at recruitment in 1996 to 2001. All participants were linked to National Health Service (NHS) hospital records for day-case or overnight admissions with a mean follow-up of 11 years per woman. Adjusted absolute and relative risks for seven site-specific incident fractures were calculated using Cox regression models. During follow-up, 4931 women had a fracture of the humerus; 2926 of the forearm; 15,883 of the wrist; 9887 of the neck of the femur; 1166 of the femur (not neck); 3199 a lower leg fracture; and 10,092 an ankle fracture. Age-specific incidence rates increased gradually with age for fractures of forearm, lower leg, ankle, and femur (not neck), and steeply with age for fractures of neck of femur, wrist, and humerus. When compared to women with desirable BMI (20.0 to 24.9 kg/m(2) ), higher BMI was associated with a reduced risk of fracture of the neck of femur, forearm, and wrist, but an increased risk of humerus, femur (not neck), lower leg, and ankle fractures (p < 0.001 for all). Strenuous activity was significantly associated with a decreased risk of fracture of the humerus and femur (both neck and remainder of femur) (p < 0.001), but was not significantly associated with lower leg, ankle, wrist, and forearm fractures. Postmenopausal women are at a high lifetime risk of fracture. BMI and physical activity are modifiable risk factors for fracture, but their associations with fracture risk differ substantially across fracture sites. © 2016 The Authors. Journal of Bone and Mineral Research published

  6. Tissue-Specific Effects of Loss of Estrogen during Menopause and Aging

    PubMed Central

    Wend, Korinna; Wend, Peter; Krum, Susan A.

    2012-01-01

    The roles of estrogens have been best studied in the breast, breast cancers, and in the female reproductive tract. However, estrogens have important functions in almost every tissue in the body. Recent clinical trials such as the Women’s Health Initiative have highlighted both the importance of estrogens and how little we know about the molecular mechanism of estrogens in these other tissues. In this review, we illustrate the diverse functions of estrogens in the bone, adipose tissue, skin, hair, brain, skeletal muscle and cardiovascular system, and how the loss of estrogens during aging affects these tissues. Early transcriptional targets of estrogen are reviewed in each tissue. We also describe the tissue-specific effects of selective estrogen receptor modulators (SERMs) used for the treatment of breast cancers and postmenopausal symptoms. PMID:22654856

  7. Muscle specific miRNAs are induced by testosterone and independently upregulated by age

    PubMed Central

    Nielsen, Søren; Hvid, Thine; Kelly, Meghan; Lindegaard, Birgitte; Dethlefsen, Christine; Winding, Kamilla; Mathur, Neha; Scheele, Camilla; Pedersen, Bente K.; Laye, Matthew J.

    2014-01-01

    Age dependent decline in skeletal muscle function leads to impaired metabolic flexibility in elderly individuals. Physical activity and testosterone treatment have proven efficient strategies for delaying this condition. However, a common molecular pathway has not been identified. Muscle specific miRNAs (myomiRs) regulate metabolic pathways in skeletal muscle, are regulated by physical activity, and have response elements for testosterone in their promoter region. We therefore hypothesized that myomiRs would be regulated in skeletal muscle during aging. We further investigated any potential gender-dependent regulation of these miRNAs. We found that the myomiRs miR-1, miR-133a, and miR-133b were increased in skeletal muscle of elderly men compared to younger men. In addition, miR-133a/133b expression was markedly higher in women compared to men. Elimination of circulating testosterone in men was associated with lower levels of miR-133a and miR-133b. A positive regulatory effect of testosterone on miR-133a/133b expression was confirmed in castrated male C57BL/6J mice and in a model of primary human myocytes. Yet, an improvement of fitness level in the testosterone depleted men resulted in a down-regulation of miR133a/b. In conclusion, alterations in fitness level and circulating testosterone seem to represent two independent regulatory events where testosterone is a specific regulator of miR-133a/b expression. PMID:24478708

  8. 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.

  9. 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

  10. Concurrent and Construct Validity of Oral Language Measures with School Age Children with Specific Language Impairment

    PubMed Central

    Hoffman, LaVae M.; Loeb, Diane Frome; Brandel, Jayne; Gillam, Ronald B.

    2013-01-01

    Purpose: This study investigated the psychometric properties of two oral language measures that are commonly used for diagnostic purposes with school age children who have language impairments. Methods: 216 children with SLI were assessed with the Test of Language Development-Primary, 3rd edition (TOLD-P:3) and the Comprehensive Assessment of Spoken Language (CASL) within a three-month period. The concurrent and construct validity of these two published tests were explored through correlation analysis and principle component factor analysis. Results: The TOLD-P:3 Spoken Language Quotient and CASL Core Composite scores were found to have an inter-test correlation value of r = .596 within this sample, and a paired samples t-test revealed a statistically significant difference between these scores. Principle component factor analyses revealed a two factor structure solution for the TOLD-P:3, while data from the CASL supported a single factor model. Conclusions: Analyses of assessment measure performance data from a sample of school age children with specific language impairment revealed concurrent validity values and construct validity patterns that differed from those found in the norming samples as cited in examiner’s manuals. Implications for practice patterns and future research are discussed. PMID:21930614

  11. 47,XXY Klinefelter syndrome: clinical characteristics and age-specific recommendations for medical management.

    PubMed

    Aksglaede, Lise; Link, Katarina; Giwercman, Aleksander; Jørgensen, Niels; Skakkebaek, Niels E; Juul, Anders

    2013-02-15

    47,XXY (Klinefelter syndrome) is the most frequent sex chromosomal disorder and affects approximately one in 660 newborn boys. The syndrome is characterized by varying degrees of cognitive, social, behavioral, and learning difficulties and in adulthood additionally primary testicular failure with small testes, hypergonadotropic hypogonadism, tall stature, and eunuchoid body proportions. The phenotype is variable ranging from "near-normal" to a significantly affected individual. In addition, newborns with Klinefelter syndrome generally present with a normal male phenotype and the only consistent clinical finding in KS is small testes, that are most often not identified until after puberty. Decreased awareness of this syndrome among health professionals and a general perception that all patients with 47,XXY exhibit the classic textbook phenotype results in a highly under-diagnosed condition with up to 75% of the patients left undetected. Typically, diagnosis is delayed with the majority of patients identified during fertility workup in adulthood, and only 10% of patients diagnosed prior to puberty. Early detection of this syndrome is recommended in order to offer treatment and intervention at the appropriate ages and stages of development for the purpose of preventing osteopenia/osteoporosis, metabolic syndrome, and other medical conditions related to hypogonadism and to the XXY as well as minimizing potential learning and psychosocial problems. The aim of this review is to present the clinical aspects of XXY and the age-specific recommendations for medical management. © 2013 Wiley Periodicals, Inc.

  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. 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.

  14. 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

  15. 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

  16. 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

    2014-10-02

    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.

  17. 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

    2016-06-30

    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.

  18. 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.

  19. Age-related changes in brain activity are specific for high order cognitive processes during successful encoding of information in working memory.

    PubMed

    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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. Precipitation Type Specific Radar Reflectivity-Rain Rate Relationships for Warsaw, Poland

    NASA Astrophysics Data System (ADS)

    Licznar, Paweł; Krajewski, Witold F.

    2016-10-01

    Implementation of weather radar precipitation estimates into hydrology, especially urban hydrology practice in Poland, requires the introduction of more precise radar reflectivity versus rain rate (Z-R) relationships accounting for drop size distribution (DSD) specific for different precipitation phases. We explored the development of precipitation type dependent Z-R relationship on the basis of approximately two years of DSD recordings at high temporal resolution of ten seconds. We divided the recorded data into four separate precipitation-type groups: rain, snow, rain-with-snow, and hail. The Z-R relationships for rain and rainwith- snow showed a strong resemblance to the well-known Marshall- Palmer Z-R power-type relationship for rain. In the case of snowfall, we found that both the multiplication factor and the exponent coefficients in the Z-R formula have smaller values than for rain. In contrast, for hail precipitation these parameters are higher than for rain, especially the multiplication factor.

  5. 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.

  6. 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

  7. Adiabatic vs. non-adiabatic determination of specific absorption rate of ferrofluids

    NASA Astrophysics Data System (ADS)

    Natividad, Eva; Castro, Miguel; Mediano, Arturo

    2009-05-01

    The measurement of temperature variations in adiabatic conditions allows the determination of the specific absorption rate of magnetic nanoparticles and ferrofluids from the correct incremental expression, SAR=(1/ m MNP) C(Δ T/Δ t). However, when measurements take place in non-adiabatic conditions, one must approximate this expression by SAR≈ Cβ/ m MNP, where β is the initial slope of the temperature vs. time curve during alternating field application. The errors arising from the use of this approximation were estimated through several experiments with different isolating conditions, temperature sensors and sample-sensor contacts. It is concluded that small to appreciable errors can appear, which are difficult to infer or control.

  8. 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

  9. Design of Miniaturized Double-Negative Material for Specific Absorption Rate Reduction in Human Head

    PubMed Central

    Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

    2014-01-01

    In this study, a double-negative triangular metamaterial (TMM) structure, which exhibits a resounding electric response at microwave frequency, was developed by etching two concentric triangular rings of conducting materials. A finite-difference time-domain method in conjunction with the lossy-Drude model was used in this study. Simulations were performed using the CST Microwave Studio. The specific absorption rate (SAR) reduction technique is discussed, and the effects of the position of attachment, the distance, and the size of the metamaterials on the SAR reduction are explored. The performance of the double-negative TMMs in cellular phones was also measured in the cheek and the tilted positions using the COMOSAR system. The TMMs achieved a 52.28% reduction for the 10 g SAR. These results provide a guideline to determine the triangular design of metamaterials with the maximum SAR reducing effect for a mobile phone. PMID:25350398

  10. Resting heart rate and the development of antisocial behavior from age 9 to 14: Genetic and environmental influences

    PubMed Central

    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. PMID:19583891

  11. 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

  12. 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

  13. Specific light uptake rates can enhance astaxanthin productivity in Haematococcus lacustris.

    PubMed

    Lee, Ho-Sang; Kim, Z-Hun; Park, Hanwool; Lee, Choul-Gyun

    2016-05-01

    Lumostatic operation was applied for efficient astaxanthin production in autotrophic Haematococcus lacustris cultures using 0.4-L bubble column photobioreactors. The lumostatic operation in this study was performed with three different specific light uptake rates (q(e)) based on cell concentration, cell projection area, and fresh weight as one-, two- and three-dimensional characteristics values, respectively. The q(e) value from the cell concentration (q(e1D)) obtained was 13.5 × 10⁻⁸ μE cell⁻¹ s⁻¹, and the maximum astaxanthin concentration was increased to 150 % compared to that of a control with constant light intensity. The other optimum q e values by cell projection area (q(e2D)) and fresh weight (q( e3D)) were determined to be 195 μE m⁻² s⁻¹ and 10.5 μE g⁻¹ s⁻¹ for astaxanthin production, respectively. The maximum astaxanthin production from the lumostatic cultures using the parameters controlled by cell projection area (2D) and fresh weight (3D) also increased by 36 and 22% over that of the controls, respectively. When comparing the optimal q e values among the three different types, the lumostatic cultures using q(e) based on fresh weight showed the highest astaxanthin productivity (22.8 mg L⁻¹ day⁻¹), which was a higher level than previously reported. The lumostatic operations reported here demonstrated that more efficient and effective astaxanthin production was obtained by H. lacustris than providing a constant light intensity, regardless of which parameter is used to calculate the specific light uptake rate.

  14. 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

  15. Variable rate application of nematicides on cotton fields: a promising site-specific management strategy.

    PubMed

    Ortiz, Brenda V; Perry, Calvin; Sullivan, Dana; Lu, Ping; Kemerait, Robert; Davis, Richard F; Smith, Amanda; Vellidis, George; Nichols, Robert

    2012-03-01

    Field tests were conducted to determine if differences in response to nematicide application (i.e., root-knot nematode (RKN) populations, cotton yield, and profitability) occurred among RKN management zones (MZ). The MZ were delineated using fuzzy clustering of five terrain (TR) and edaphic (ED) field features related to soil texture: apparent soil electrical conductivity shallow (ECa-shallow) and deep (ECa-deep), elevation (EL), slope (SL), and changes in bare soil reflectance. Zones with lowest mean values of ECa- shallow, ECa- deep, NDVI, and SL were designated as at greater risk for high RKN levels. Nematicide-treated plots (4 rows wide and 30 m long) were established in a randomized complete block design within each zone, but the number of replications in each zone varied from four to six depending on the size of the zone.The nematicides aldicarb (Temik 15 G) and 1,3-dichloropropene (1,3-D,Telone II) were applied at two rates (0.51 and 1.0 kg a.i./ha for aldicarb, and 33.1 and 66.2 kg a.i./ha for 1,3-D) to RKN MZ in commercial fields between 2007 and 2009. A consolidated analysis over the entire season showed that regardless of the zone, there were not differences between aldicarb rates and 1,3-D rates. The result across zones showed that 1,3-D provided better RKN control than did aldicarb in zones with low ECa values (high RKN risk zones exhibiting more coarse-textured sandy soils). In contrast, in low risk zones with relatively higher ECa values (heavier textured soil), the effects of 1,3-D and aldicarb were equal and application of any of the treatments provided sufficient control. In low RKN risk zones, a farmer would often have lost money if a high rate of 1,3-D was applied. This study showed that the effect of nematicide type and rate on RKN control and cotton yield varied across management zones (MZ) with the most expensive treatment likely to provide economic benefit only in zones with coarser soil texture. This study demonstrates the value of site

  16. Volcanic Event Recurrence Rate Model (VERRM): Incorporating Radiometric Ages, Volcanic Stratigraphy and Paleomagnetic Data into a Monte Carlo Simulation to Estimate Uncertainty in Recurrence Rate through Time

    NASA Astrophysics Data System (ADS)</