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Sample records for age time spent

  1. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Time spent traveling. 551.422 Section 551... Activities § 551.422 Time spent traveling. (a) Time spent traveling shall be considered hours of work if: (1... who is permitted to use an alternative mode of transportation, or an employee who travels at a...

  2. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Time spent traveling. 551.422 Section 551... Activities § 551.422 Time spent traveling. (a) Time spent traveling shall be considered hours of work if: (1... who is permitted to use an alternative mode of transportation, or an employee who travels at a...

  3. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Time spent traveling. 551.422 Section 551... Activities § 551.422 Time spent traveling. (a) Time spent traveling shall be considered hours of work if: (1... who is permitted to use an alternative mode of transportation, or an employee who travels at a...

  4. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Time spent traveling. 551.422 Section 551... Activities § 551.422 Time spent traveling. (a) Time spent traveling shall be considered hours of work if: (1... who is permitted to use an alternative mode of transportation, or an employee who travels at a...

  5. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Time spent traveling. 551.422 Section 551... Activities § 551.422 Time spent traveling. (a) Time spent traveling shall be considered hours of work if: (1... who is permitted to use an alternative mode of transportation, or an employee who travels at a...

  6. 5 CFR 551.425 - Time spent receiving medical attention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Time spent receiving medical attention... Relation to Other Activities § 551.425 Time spent receiving medical attention. (a) Time spent waiting for and receiving medical attention for illness or injury shall be considered hours of work if: (1)...

  7. Adolescent Depression and Time Spent with Parents and Siblings

    ERIC Educational Resources Information Center

    Desha, Laura N.; Nicholson, Jan M.; Ziviani, Jenny M.

    2011-01-01

    This study examines adolescent depressive symptoms and the quantity and quality of time spent by adolescents with their parents and siblings. We use measures of the quality of relationships with parents and siblings as proxy indicators for the quality of time spent with these social partners. The study emphasizes the salience of parent…

  8. Do Workplace Flexibility Policies Influence Time Spent in Domestic Labor?

    ERIC Educational Resources Information Center

    Noonan, Mary C.; Estes, Sarah Beth; Glass, Jennifer L.

    2007-01-01

    Using data from a U.S. midwestern sample of mothers and fathers, the authors examine whether using workplace flexibility policies alters time spent in housework and child care. They hypothesize that an individual's policy use will lead to more time in domestic labor and that his or her spouse's policy use will lead to less time in domestic labor.…

  9. Measuring Time Spent on Teaching Native Language.

    ERIC Educational Resources Information Center

    Otter, Martha E.; And Others

    1992-01-01

    Mail survey, telephone survey, and keeping time were compared as methods of assessing teaching time for 74 sixth grade teachers teaching language in the Netherlands. Results suggest that each of the three methods can be used to assess the mean total score, but none can assess individual scores. (SLD)

  10. Time Spent in Indirect Nursing Care

    DTIC Science & Technology

    1983-09-01

    Part of the FY 83 Army Study Program and intended to augment the FY 81 completed study titled ’ Nursing Care Hours Standards’ by providing valid and...reliable percentages for hospital patient nursing care unit requirements (i.e., direct care, indirect care, and non-productive time). These data

  11. Time Spent Eating and Its Implications for Americans' Energy Balance

    ERIC Educational Resources Information Center

    Zick, Cathleen D.; Stevens, Robert B.

    2011-01-01

    The upward trend in Americans' weight has precipitated research aimed at identifying its underlying causes. In this paper we examine trends in Americans' time spent eating in an attempt to gain a better understanding of Americans' changing eating habits and their predictors. Data used in the analyses come from four national time use surveys…

  12. High-Ability Students' Time Spent outside the Classroom

    ERIC Educational Resources Information Center

    Makel, Matthew C.; Li, Yan; Putallaz, Martha; Wai, Jonathan

    2011-01-01

    This study considered how three groups of academically talented high school students--those who attended an academic summer program (TIP), those who qualified for the program but chose not to attend (QNA), and those who did not qualify (DNQ)--spent time outside the classroom. These groupings differentiated students by ability (QNA vs. DNQ) and…

  13. Time Spent on the Internet and Adolescent Blood Pressure

    ERIC Educational Resources Information Center

    Cassidy-Bushrow, Andrea E.; Johnson, Dayna A.; Peters, Rosalind M.; Burmeister, Charlotte; Joseph, Christine L. M.

    2015-01-01

    Internet use is nearly ubiquitous among adolescents. Growing evidence suggests heavy Internet use negatively impacts health, yet the relationship between time spent on the Internet and adolescent blood pressure (BP) is unknown. We examined the association between Internet use and elevated BP in a racially diverse cross-sectional sample of 331…

  14. Time spent with smoking parents and smoking topography in adolescents.

    PubMed

    Collins, Charles C; Lippmann, Brad M; Lo, Suzanne J; Moolchan, Eric T

    2008-12-01

    Although the relationship between parental and adolescent smoking has been linked to health consequences of smoking, limited study has explored the specific association between exposure to smoking and adolescent smoking topography (the way a cigarette is smoked). As a first step in this line of enquiry, smoking topography measures were collected from 67 adolescent dependent smokers. Participants smoked one cigarette of their own brand while being monitored by a computer-based smoking-topography unit and completed questionnaires about their time spent daily with parents who smoke. Pearson's correlation analysis revealed that time spent daily with parents who smoke was significantly associated with maximum puff velocity (r=0.285, p=.019), a parameter predicting later pulmonary morbidity. ANOVAs, after a median split, were consistent with correlation analyses. There was a significant group effect on puff velocity (F(2,66)=5.197, p=.008); no significant relationship was found with puff volume (F(2,66)=.617) or puff duration (F(2,66)=.776). A post hoc Tukey HSD test indicated puff velocity was higher in the "high time spent" (M=54.37, SD=12.03) than in the "low time spent" group (M=45.59, SD=9.91) and in the group with non-smoking parents (M=44.96, SD=10.17). Future research with a larger non-treatment seeking sample of adolescents aimed at preventing tobacco smoking related diseases should further examine parental influences on adolescent smoking, including potential modeling effects.

  15. Time Spent on the Internet and Adolescent Blood Pressure.

    PubMed

    Cassidy-Bushrow, Andrea E; Johnson, Dayna A; Peters, Rosalind M; Burmeister, Charlotte; Joseph, Christine L M

    2015-10-01

    Internet use is nearly ubiquitous among adolescents. Growing evidence suggests heavy Internet use negatively impacts health, yet the relationship between time spent on the Internet and adolescent blood pressure (BP) is unknown. We examined the association between Internet use and elevated BP in a racially diverse cross-sectional sample of 331 healthy adolescents (ages 14-17 years). Heavy Internet use was defined as ≥ 2 hr/day, moderate use as <2 hr/day and ≥ 5 days/week, and light use as < 2 hr/day and ≤ 4 days/week. Elevated BP was defined as systolic or diastolic BP ≥ 90 th percentile. Heavy Internet users had statistically significantly higher odds of elevated BP compared to light Internet users. School nurses can play an important role in preventing high BP through assessment of BP and other health behaviors including Internet use, and health teaching to individuals, student groups, faculty, and parents to increase awareness of the relationship between Internet use and health.

  16. The independent relationship between trouble controlling Facebook use, time spent on the site and distress

    PubMed Central

    Muench, Fredrick; Hayes, Marie; Kuerbis, Alexis; Shao, Sijing

    2015-01-01

    Background and Aims There is an emerging literature base on the relationship between maladaptive traits and “addiction” to social networking sites. These studies have operationalized addiction as either spending excessive amounts of time on social networking sites (SNS) or trouble controlling SNS use, but have not assessed the unique contribution of each of these constructs on outcomes in the same models. Moreover, these studies have exclusively been conducted with younger people rather than a heterogeneous sample. This study examined the independent relationship of a brief Facebook addiction scale, time spent on Facebook, and Facebook checking on positive and negative social domains, while controlling for self-esteem and social desirability. Methods Participants were recruited using e-mail, SNS posts and through Amazon’s MTurk system. The sample included 489 respondents ages from 18 to approximately 70, who completed a 10–15 minute survey. Results Results indicate that neither time spent on Facebook nor Facebook checking was significantly associated with either self-esteem, fear of negative social evaluation or social comparison, while SNS addiction symptoms were each independently associated with Facebook usage. Neither time spent on Facebook nor SNS addiction symptoms were associated with positive social relationships. Discussion Overall results suggest that time on SNS and trouble controlling use should be considered independent constructs and that interventions should target underlying loss of control as the primary intervention target above ego syntonic time spent on the site. PMID:26551906

  17. Spent fuel temperature and age determination from the analysis of uranium and plutonium isotopics

    SciTech Connect

    Scott, Mark R; Eccleston, George W; Bedell, Jeffrey J; Lockard, Chanelle M

    2009-01-01

    The capability to determine the age (time since irradiation) of spent fuel can be useful for verification and safeguards. While the age of spent fuel can be determined based on measurements of short-lived fission products, these measurements are not routinely done nor generally reported. As an alternative, age can also be determined if the uranium (U) and plutonium (Pu) isotopic values are available. Uranium isotopics are not strongly affected by fuel temperature, and bumup is determined from the {sup 235}U and {sup 236}U isotopic values. Age is calculated after estimating the {sup 241}Pu at the end of irradiation while accounting for the fuel temperature, which is determined from {sup 239}Pu or {sup 240}Pu. Burnup and age determinations are calibrated to reactor models that provide uranium and plutonium isotopics over the range of fuel irradiation. The reactor model must contain sufficient fidelity on details of the reactor type, fuel burnup, irradiation history, initial fuel enrichment and fuel temperature to obtain accurate isotopic calculations. If the latter four are unknown, they can be derived from the uranium and plutonium isotopics. Fuel temperature has a significant affect on the production of plutonium isotopics; therefore, one group cross section reactor models, such as ORIGEN, cannot be used for these calculations. Multi-group cross section set codes, such as Oak Ridge National Laboratory's TRITON code, must be used.

  18. Associations between Parental and Friend Social Support and Children's Physical Activity and Time Spent outside Playing

    PubMed Central

    Tsangaridou, Niki

    2017-01-01

    The purpose of this study was to examine the structural validity of a parent and a child questionnaire that assessed parental and friends' influences on children's physical activity and investigate the associations between the derived factors, physical activity, and time spent outside. Children (N = 154, mean age = 11.7) and 144 of their parents completed questionnaires assessing parental and friends' influences on children's physical activity. Children wore a pedometer for six days. Exploratory factor analyses revealed four factors for the parental and five for the child's questionnaire that explained 66.71% and 63.85% of the variance, respectively. Five factors were significantly associated with physical activity and five significantly associated with time spent outside. Higher correlations were revealed between “general friend support,” “friends' activity norms,” and physical activity (r = 0.343 and 0.333 resp., p < 0.001) and between “general friend support” and time spent outside (r = 0.460, p < 0.001). Obtaining information relating to parental and friends' influences on physical activity from both parents and children may provide a more complete picture of influences. Parents and friends seem to influence children's physical activity behavior and time spent outside, but friends' influences may have a stronger impact on children's behaviors. PMID:28348605

  19. Determinants of Children's Use of and Time Spent in Fast-Food and Full-Service Restaurants

    ERIC Educational Resources Information Center

    McIntosh, Alex; Kubena, Karen S.; Tolle, Glen; Dean, Wesley; Kim, Mi-Jeong; Jan, Jie-Sheng; Anding, Jenna

    2011-01-01

    Objective: Identify parental and children's determinants of children's use of and time spent in fast-food (FF) and full-service (FS) restaurants. Design: Analysis of cross-sectional data. Setting: Parents were interviewed by phone; children were interviewed in their homes. Participants: Parents and children ages 9-11 or 13-15 from 312 families…

  20. Racing Against the Clock: Internal Medicine Residents' Time Spent On Electronic Health Records

    PubMed Central

    Chen, Lu; Guo, Uta; Illipparambil, Lijo C.; Netherton, Matt D.; Sheshadri, Bhairavi; Karu, Eric; Peterson, Stephen J.; Mehta, Parag H.

    2016-01-01

    Background Since the late 1980s, resident physicians have spent increasing amounts of time on electronic health record (EHR) data entry and retrieval. Objective longitudinal data measuring time spent on the EHR are lacking. Objective We sought to quantify the time actually spent using the EHR by all first-year internal medicine residents in a single program (N = 41). Methods Active EHR usage data were collected from the audit logs for May, July, and October 2014 and January 2015. Per recommendations from our EHR vendor (Cerner Corporation), active EHR usage time was defined as more than 15 keystrokes, or 3 mouse clicks, or 1700 “mouse miles” per minute. Active EHR usage time was tallied for each patient chart viewed each day and termed an electronic patient record encounter (EPRE). Results In 4 months, 41 interns accumulated 18 322 hours of active EHR usage in more than 33 733 EPREs. Each intern spent on average 112 hours per month on 206 EPREs. Interns spent more time in July compared to January (41 minutes versus 30 minutes per EPRE, P < .001). Time spent on the EHR in January echoed that of the previous May (30 minutes versus 29 minutes, P = .40). Conclusions First-year residents spent a significant amount of time actively using the EHR, achieving maximal proficiency on or before January of the academic year. Decreased time spent on the EHR may reflect greater familiarity with the EHR, growing EHR efficiencies, or other factors. PMID:26913101

  1. Time Spent, Workload, and Student and Faculty Perceptions in a Blended Learning Environment

    PubMed Central

    Schumacher, Christie; Arif, Sally

    2016-01-01

    Objective. To evaluate student perception and time spent on asynchronous online lectures in a blended learning environment (BLE) and to assess faculty workload and perception. Methods. Students (n=427) time spent viewing online lectures was measured in three courses. Students and faculty members completed a survey to assess perceptions of a BLE. Faculty members recorded time spent creating BLEs. Results. Total time spent in the BLE was less than the allocated time for two of the three courses by 3-15%. Students preferred online lectures for their flexibility, students’ ability to apply information learned, and congruence with their learning styles. Faculty members reported the BLE facilitated higher levels of learning during class sessions but noted an increase in workload. Conclusion. A BLE increased faculty workload but was well received by students. Time spent viewing online lectures was less than what was allocated in two of the three courses. PMID:27667839

  2. Time Spent, Workload, and Student and Faculty Perceptions in a Blended Learning Environment.

    PubMed

    Phillips, Jennifer A; Schumacher, Christie; Arif, Sally

    2016-08-25

    Objective. To evaluate student perception and time spent on asynchronous online lectures in a blended learning environment (BLE) and to assess faculty workload and perception. Methods. Students (n=427) time spent viewing online lectures was measured in three courses. Students and faculty members completed a survey to assess perceptions of a BLE. Faculty members recorded time spent creating BLEs. Results. Total time spent in the BLE was less than the allocated time for two of the three courses by 3-15%. Students preferred online lectures for their flexibility, students' ability to apply information learned, and congruence with their learning styles. Faculty members reported the BLE facilitated higher levels of learning during class sessions but noted an increase in workload. Conclusion. A BLE increased faculty workload but was well received by students. Time spent viewing online lectures was less than what was allocated in two of the three courses.

  3. Teacher Time Spent on Student Health Issues and School Nurse Presence

    ERIC Educational Resources Information Center

    Hill, Nina Jean; Hollis, Marianne

    2012-01-01

    Elementary school teacher time spent on student health issues and the relationship to school nurse services was the focus of this 2-year study. A cross-sectional design was used to survey traditional and exceptional (special needs) classroom teachers about the time they spent on health issues and their perception of school nurse presence. The…

  4. Time Spent on Homework, Mathematics Anxiety and Mathematics Achievement: Evidence from a US Sample

    ERIC Educational Resources Information Center

    Cheema, Jehanzeb R.; Sheridan, Kimberly

    2015-01-01

    This study investigated the effect of time spent on homework and mathematics anxiety on mathematics achievement. Data from a nationally representative US sample consisting of 4,978 cases was used to predict mathematics achievement from time spent on homework and mathematics anxiety while controlling for demographic differences such as gender,…

  5. Time spent sitting during and outside working hours in bus drivers: A pilot study

    PubMed Central

    Varela-Mato, Veronica; Yates, Thomas; Stensel, David J.; Biddle, Stuart J.H.; Clemes, Stacy A.

    2015-01-01

    This cross-sectional pilot study objectively measured sedentary and non-sedentary time in a sample of bus drivers from the East Midlands, United Kingdom. Participants wore an activPAL3 inclinometer for 7 days and completed a daily diary. Driver's blood pressure, heart rate, waist circumference and body composition were measured objectively at the outset. The proportions of time spent sedentary and non-sedentary were calculated during waking hours on workdays and non-workdays and during working-hours and non-working-hours on workdays. 28 (85% of those enrolled into the study) provided valid objective monitoring data (89.3% male, [median ± IQR] age: 45.2 ± 12.8 years, BMI 28.1 ± 5.8 kg/m2). A greater proportion of time was spent sitting on workdays than non-workdays (75% [724 ± 112 min/day] vs. 62% [528 ± 151 min/day]; p < 0.001), and during working-hours than non-working-hours (83% [417 ± 88 min/day] vs. 68% [307 ± 64 min/day]; p < 0.001) on workdays. Drivers spent less than 3% of their overall time stepping. Bus drivers accumulate high levels of sitting time during working-hours and outside working-hours. Interventions are urgently needed in this at-risk group, which should focus on reducing sitting and increasing movement during breaks and increasing physical activity during leisure time to improve cardiovascular health. PMID:26844184

  6. Time spent sitting during and outside working hours in bus drivers: A pilot study.

    PubMed

    Varela-Mato, Veronica; Yates, Thomas; Stensel, David J; Biddle, Stuart J H; Clemes, Stacy A

    2016-06-01

    This cross-sectional pilot study objectively measured sedentary and non-sedentary time in a sample of bus drivers from the East Midlands, United Kingdom. Participants wore an activPAL3 inclinometer for 7 days and completed a daily diary. Driver's blood pressure, heart rate, waist circumference and body composition were measured objectively at the outset. The proportions of time spent sedentary and non-sedentary were calculated during waking hours on workdays and non-workdays and during working-hours and non-working-hours on workdays. 28 (85% of those enrolled into the study) provided valid objective monitoring data (89.3% male, [median ± IQR] age: 45.2 ± 12.8 years, BMI 28.1 ± 5.8 kg/m(2)). A greater proportion of time was spent sitting on workdays than non-workdays (75% [724 ± 112 min/day] vs. 62% [528 ± 151 min/day]; p < 0.001), and during working-hours than non-working-hours (83% [417 ± 88 min/day] vs. 68% [307 ± 64 min/day]; p < 0.001) on workdays. Drivers spent less than 3% of their overall time stepping. Bus drivers accumulate high levels of sitting time during working-hours and outside working-hours. Interventions are urgently needed in this at-risk group, which should focus on reducing sitting and increasing movement during breaks and increasing physical activity during leisure time to improve cardiovascular health.

  7. Estimation of sensitivity depending on sojourn time and time spent in preclinical state.

    PubMed

    Kim, Seongho; Wu, Dongfeng

    2016-04-01

    The probability model for periodic screening was extended to provide statistical inference for sensitivity depending on sojourn time, in which the sensitivity was modeled as a function of time spent in the preclinical state and the sojourn time. The likelihood function with the proposed sensitivity model was then evaluated with simulated data to check its reliability in terms of the mean estimation and the standard error. Simulation results showed that the maximum likelihood estimates of the proposed model have little bias and small standard errors. The extended probability model was further applied to the Johns Hopkins Lung Project data using both maximum likelihood estimation and Bayesian Markov chain Monte Carlo.

  8. Racial/ethnic and gender differences among older adults in nonmonogamous partnerships, time spent single, and HIV testing

    PubMed Central

    Harawa, Nina T.; Leng, Mei; Kim, Junyeop; Cunningham, William Emery

    2011-01-01

    Background A higher frequency of nonmonogamy, due in part to lower marriage prevalence, may contribute to elevated HIV/STD rates among older Blacks. Methods To examine race and gender differences in nonmonogamy, time spent single (i.e., not married or cohabiting), and HIV testing in older adults, we analyzed U.S. population-based data from the 2005-06 National Social Life, Health, and Aging Project (NSHAP) for 2,825 heterosexual participants ages 57-85 years. Results Blacks spent greater portions of their adult lives single than did Hispanics or Whites and were far more likely to report recent nonmonogamous partnerships (23.4% vs. 10.0% and 8.2%). Among individuals reporting sex in the prior 5 years, nonmonogamous partnerships were strongly associated with time spent single during the period. Control for time spent single and other covariates reduced the association of Black race with nonmonogamous partnerships for men but increased it for women. Less than 20% reported ever testing for HIV; less than 6% had been recommended testing by a provider. Testing rates, highest in Black men and White women, differed little by history of nonmonogamous partnerships within gender strata. Conclusions Singlehood helps to explain higher nonmonogamous partnership rates in older Black men but not older Black women. Older adults rarely receive or are recommended HIV testing, a key strategy for reducing heterosexual HIV transmission. PMID:22082721

  9. Muddy conditions reduce hygiene and lying time in dairy cattle and increase time spent on concrete.

    PubMed

    Chen, Jennifer M; Stull, Carolyn L; Ledgerwood, David N; Tucker, Cassandra B

    2017-03-01

    Dairy cattle spend less time lying and show signs of increased stress when housed in rainy and windy conditions, but no work has separated the effects of exposure to inclement weather from muddy conditions underfoot. Our objective was to evaluate the effects of muddy conditions alone on lying behavior, hygiene, and physiological responses. We housed pairs of pregnant, nonlactating dairy cattle (n = 12; 6 primigravid heifers, 6 multiparous cows) in enclosed pens with dirt floors and a concrete feed apron. Cattle were exposed to 3 levels of soil moisture: 90 (dry), 74 (muddy), or 67% (very muddy) dry matter for 5 d each in a replicated 3 × 3 Latin square design. Lying time was measured on all days with data loggers, and lying locations and postures were recorded on the final day of each treatment. Before and after each treatment, blood samples were collected, and the percentage of dirty surface area was measured on the udder, hind leg, and side of each animal. Cattle spent less time lying down in muddier conditions, especially in the first 24 h of exposure, when cows and heifers spent only 3.2 and 5.8 h, respectively, lying down in the muddiest treatment compared with 12.5 and 12.7 h on dry soil. When the soil was dry, cattle never chose to lie down on concrete, but in muddier conditions they spent a greater proportion of their lying time on concrete (mean ± SE: 56 ± 14 and 10 ± 8% in the very muddy and muddy treatments, respectively). The shift in lying location was more marked for heifers, and all 6 spent ≥87% of their lying time on concrete in the muddiest treatment. When cattle chose to lie down on wetter soil, they limited the surface area exposed to their surroundings by tucking their legs beneath their bodies (mean ± SE: 30 ± 11, 15 ± 4, and 5 ± 2% of lying observations in the very muddy, muddy, and dry treatments, respectively). Despite cattle spending less time on wetter soil, all 3 measured body parts became dirtier in muddier conditions (1.4-, 1

  10. Overweight according to geographical origin and time spent in France: a cross sectional study in the Paris metropolitan area

    PubMed Central

    2012-01-01

    Background For the first time in France in a population-based survey, this study sought to investigate the potential impact of migration origin and the proportion of lifetime spent in mainland France on body mass index (BMI) and overweight in adults living in the Paris metropolitan area. Methods A representative, population-based, random sample of the adult, French speaking population of the Paris metropolitan area was interviewed in 2005. Self-reported BMI (BMI = weight/height2) and overweight (BMI ≥ 25) were our 2 outcomes of interest. Two variables were constructed to estimate individuals’ migration origin: parental nationality and the proportion of lifetime spent in mainland France, as declared by the participants. We performed multilevel regression models among different gender and age groups, adjusted for demographics and socioeconomic status. Results In women, a parental origin in the Middle East or North Africa (MENA) was associated with a higher risk of being overweight (especially before the age of 55) and a higher BMI (between 35 and 54 years of age), and so were women of Sub-Sahara African parental origin in the middle age category. Only in the youngest men (< 35 years of age) did we observe any association with parental nationality, with a higher BMI when having a MENA parentage. Regarding the association between the proportion of lifetime spent in France and overweight, we observed that, in women, a proportion of 50% to 99% appeared to be associated with overweight, especially after the age of 35. In men, having spent more than half of one’s lifetime in France was associated with a higher risk of overweight among oldest men. Conclusions Our results plea for potential cultural determinants of overweight in the migrant and migrants-born populations in the French context of the capital region. Taking into account the people’ family and personal migration histories may be an important issue in public health research and policies on overweight and

  11. Time's up. descriptive epidemiology of multi-morbidity and time spent on health related activity by older Australians: a time use survey.

    PubMed

    Jowsey, Tanisha; McRae, Ian S; Valderas, Jose M; Dugdale, Paul; Phillips, Rebecca; Bunton, Robin; Gillespie, James; Banfield, Michelle; Jones, Lesley; Kljakovic, Marjan; Yen, Laurann

    2013-01-01

    Most Western health systems remain single illness orientated despite the growing prevalence of multi-morbidity. Identifying how much time people with multiple chronic conditions spend managing their health will help policy makers and health service providers make decisions about areas of patient need for support. This article presents findings from an Australian study concerning the time spent on health related activity by older adults (aged 50 years and over), most of whom had multiple chronic conditions. A recall questionnaire was developed, piloted, and adjusted. Sampling was undertaken through three bodies; the Lung Foundation Australia (COPD sub-sample), National Diabetes Services Scheme (Diabetes sub-sample) and National Seniors Australia (Seniors sub-sample). Questionnaires were mailed out during 2011 to 10,600 older adults living in Australia. 2540 survey responses were received and analysed. Descriptive analyses were completed to obtain median values for the hours spent on each activity per month. The mean number of chronic conditions was 3.7 in the COPD sub-sample, 3.4 in the Diabetes sub-sample and 2.0 in the NSA sub-sample. The study identified a clear trend of increased time use associated with increased number of chronic conditions. Median monthly time use was 5-16 hours per month overall for our three sub-samples. For respondents in the top decile with five or more chronic conditions the median time use was equivalent to two to three hours per day, and if exercise is included in the calculations, respondents spent from between five and eight hours per day: an amount similar to full-time work. Multi-morbidity imposes considerable time burdens on patients. Ageing is associated with increasing rates of multi-morbidity. Many older adults are facing high demands on their time to manage their health in the face of decreasing energy and mobility. Their time use must be considered in health service delivery and health system reform.

  12. Reading-Related Literacy Activities of American Adults: Time Spent, Task Types, and Cognitive Skills Used

    ERIC Educational Resources Information Center

    White, Sheida; Chen, Jing; Forsyth, Barbara

    2010-01-01

    This article presents data on the types and duration of reading-related activities reported by a volunteer sample of 400 adults (demographically similar to the U.S. adult population age 20 and older in terms of race, ethnicity, education, and working status) in the 2005 Real-World Tasks Study. This diary study revealed that adults spent, on…

  13. Time spent with friends in adolescence relates to less neural sensitivity to later peer rejection.

    PubMed

    Masten, Carrie L; Telzer, Eva H; Fuligni, Andrew J; Lieberman, Matthew D; Eisenberger, Naomi I

    2012-01-01

    Involvement with friends carries many advantages for adolescents, including protection from the detrimental effects of being rejected by peers. However, little is known about the mechanisms through which friendships may serve their protective role at this age, or the potential benefit of these friendships as adolescents transition to adulthood. As such, this investigation tested whether friend involvement during adolescence related to less neural sensitivity to social threats during young adulthood. Twenty-one adolescents reported the amount of time they spent with friends outside of school using a daily diary. Two years later they underwent an fMRI scan, during which they were ostensibly excluded from an online ball-tossing game by two same-age peers. Findings from region of interest and whole brain analyses revealed that spending more time with friends during adolescence related to less activity in the dorsal anterior cingulate cortex and anterior insula--regions previously linked with negative affect and pain processing--during an experience of peer rejection 2 years later. These findings are consistent with the notion that positive relationships during adolescence may relate to individuals being less sensitive to negative social experiences later on.

  14. Time well spent? Assessing nursing-supply chain activities.

    PubMed

    Ferenc, Jeff

    2010-02-01

    The amount of time nurses spend providing direct patient care seems to be continually eroding. So it's little wonder a survey conducted last year of critical care, OR nurses and nurse executives found that half of the 1600 respondents feel they spend too much time on supply chain duties. Most also said their supply chain duties impact patient safe ty and their ability to provide bedside care. Experts interviewed for this report believe it's time for supply chain leaders and nurses to develop a closer working partnership. Included are their recommendations to improve performance.

  15. Teacher time spent on student health issues and school nurse presence.

    PubMed

    Hill, Nina Jean; Hollis, Marianne

    2012-06-01

    Elementary school teacher time spent on student health issues and the relationship to school nurse services was the focus of this 2-year study. A cross-sectional design was used to survey traditional and exceptional (special needs) classroom teachers about the time they spent on health issues and their perception of school nurse presence. The school nurses were surveyed regarding the impact of their presence on early releases due to illness. Study findings related to teacher perceptions indicate with school nurse presence there are fewer early releases, increased communication, less time spent on health issues, students with chronic illnesses are safer, and there is a resource available for health information. The data provide the groundwork for discussions to improve the communication of the nurses' schedules, increase teacher confidence in consistent nurse hours at their school and aid the nurse in protecting valuable on-site school hours from other interferences or commitments.

  16. Academic Performance of College Students: Influence of Time Spent Studying and Working

    ERIC Educational Resources Information Center

    Nonis, Sarath A.; Hudson, Gail I.

    2006-01-01

    Today's college students are less prepared for college-level work than their predecessors. Once they get to college, they tend to spend fewer hours studying while spending more hours working, some even full time (D. T. Smart, C. A. Kelley, & J. S. Conant, 1999). In this study, the authors examined the effect of both time spent studying and time…

  17. Changes in Time Spent Outdoors During the Daytime in Rural Populations in Four Geographically Distinct Regions in China: A Retrospective Study.

    PubMed

    Gao, Qian; Wang, Fang; Hu, Liwen; Yu, Jiaming; Liu, Rong; Wang, Yang; Liu, Yang

    2017-03-01

    Changes in time-activity patterns may influence personal exposure to various environmental factors and affect individual health. However, few studies have investigated the changes in patterns of time spent outdoors. To investigate the trends in outdoor activity in recent decades in China, a retrospective questionnaire was used to examine the amount and pattern of time spent outdoors during the day by 2076 subjects in four geographically distinct rural regions of China. Rural Chinese people spent less time outdoors than they used to because of the economic development, increase in education and changes in working conditions that occurred over time. Outdoor time was the shortest during the school stage of life (Sanya: 3.24-3.61; Shaoxing: 3.35-3.68; Lhasa: 4.37-4.54; Xiuyan: 2.94-3.26 h per day). Subjects in wealthy regions spent less time outdoors during their working stage of life. In the four regions in this study, the average daily times spent outdoors were 3-13% lower for subjects aged 40-59 years and 20-38% lower for those under 40 years compared to subjects aged 60 years and over. Certain health-related issues, such as vitamin D deficiency, will become more prominent in China if this trend continues.

  18. Monetary cost for time spent in everyday physical activities.

    PubMed

    Hsu, Anne S; Vlaev, Ivo

    2014-05-01

    We measured utility curves for the hypothetical monetary costs as a function of time engaged in three everyday physical activities: walking, standing, and sitting. We found that activities requiring more physical exertion resulted in steeper discount curves, i.e., perceived cost as a function of time. We also examined the effects of gain vs. loss framing (whether the activity brought additional rewards or prevented losses) as well as the effects of the individual factors of gender, income, and BMI. Steeper discount curves were associated with higher income (annual household ≥ median of $45,000) and gain framing (which indicates loss aversion). There were interactions between gender and frame, and also income and frame: Females and higher income participants showed loss aversion whereas males and lower income participants were not affected by framing. Males showed less discounting in gain frames relative to females, whereas females showed less discounting in loss frames relative to males. In gain frames, higher income participants discounted more but in loss frames there was no effect of income. We also found individual tendencies for discounting across activities: if an individual exhibited steeper discounting for one activity, they were also more likely to exhibit steeper discounting for the other activities. These results have implications for designers of interventions to encourage non-exercise physical activities, suggesting that loss-framed incentives are more effective for women and those with middle class (or greater) incomes. Furthermore loss framed incentives have more uniform impact across income brackets because people discount loss frames similarly regardless of income whereas those with middle-class incomes are not as motivated by gain frames. Our results also demonstrate a general method for examining the costs of effort associated with everyday activities.

  19. Objective Assessment of Time Spent Being Sedentary in Bariatric Surgery Candidates

    PubMed Central

    Unick, Jessica L.; Jakicic, John M.; Vithiananthan, Sivamainthan; Pohl, Dieter; Roye, G. Dean; Ryder, Beth A.; Sax, Harry C.; Giovanni, Jeannine; Wing, Rena R.

    2010-01-01

    Background Bariatric surgery candidates spend very little time in moderate-to-vigorous intensity physical activity (≥3 metabolic equivalents [METs]). This study examined (1) how much of their remaining time is spent in sedentary behaviors (SB<1.5 METs) compared to light-intensity activities (1.5–2.9 METs) and (2) whether sedentary time varies by BMI. Methods Daily time (hours, %) spent in SB was examined in 42 surgery candidates (BMI=49.5±7.9 kg/m2) using the SenseWear Pro2 Armband. Participants were stratified by BMI to assess the relationship between degree of obesity and SB. Results Participants wore the armband for 5.4±0.7 days and 13.3±1.7 h/day. On average, 81.4% (10.9±2.1 h/day) of this time was spent in SB. Participants with BMI≥50 spent nearly an hour more per day in SB than those with BMI 35–49.9 (p=0.01). Conclusions Bariatric surgery candidates spend over 80% of their time in SB. Reducing SB may help to increase physical activity in these patients. PMID:20393808

  20. The Relationship between Motivation, Learning Approaches, Academic Performance and Time Spent

    ERIC Educational Resources Information Center

    Everaert, Patricia; Opdecam, Evelien; Maussen, Sophie

    2017-01-01

    Previous literature calls for further investigation in terms of precedents and consequences of learning approaches (deep learning and surface learning). Motivation as precedent and time spent and academic performance as consequences are addressed in this paper. The study is administered in a first-year undergraduate course. Results show that the…

  1. 48 CFR 852.271-72 - Time spent by counselee in counseling process.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Time spent by counselee in counseling process. 852.271-72 Section 852.271-72 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions...

  2. Parent Perceptions of Time Spent Meaningfully by Young Adults with Pervasive Support Needs

    ERIC Educational Resources Information Center

    Rossetti, Zachary; Lehr, Donna; Lederer, Leslie; Pelerin, Dana; Huang, Shuoxi

    2015-01-01

    This article describes a qualitative study that examined how 23 young adults with pervasive support needs and limited functional communication spent their time and how their parents (n = 23) and direct support professionals (DSPs; n = 2) defined meaningfulness in relation to the young adults' experiences. Data were collected through…

  3. 5 CFR 551.423 - Time spent in training or attending a lecture, meeting, or conference.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... working hours shall be considered hours of work. (2) Time spent in training outside regular working hours... apprenticeship or other entry level training, or internship or other career related work study training, or training under the Veterans Recruitment Act (5 CFR part 307) outside regular working hours shall not...

  4. Time spent by Belgian hospital pharmacists on supply disruptions and drug shortages: An exploratory study

    PubMed Central

    De Weerdt, Elfi; De Rijdt, Thomas; Simoens, Steven; Casteels, Minne; Huys, Isabelle

    2017-01-01

    Introduction Supply problems of drugs are an increasing and worldwide problem, also in Belgium. Hospital pharmacists try to manage drug supply problems to minimize the impact on patient care. This study aims to quantify in a detailed manner how much time employees of 17 Belgian hospital pharmacies spend on drug supply problems. Methods During six months, employees of Belgian hospital pharmacies filled in the daily time spent on drug supply problems using a template containing all steps which can be executed to manage drug supply problems. Additionally, Belgian hospital pharmacists were asked to report the drugs which experienced drug supply problems together with the solution for this problem. Results Hospital pharmacists spent a median of 109 minutes a week on drug supply problems, with a minimum of 40 minutes per week and a maximum of 216 minutes per week. Fifty-nine percent of the total time spent on drug supply problems was executed by hospital pharmacists, 27% by pharmacy technicians; the rest was performed by logistic or administrative personnel. About one third of the total time spent was invested in gathering information on the supply problem. About two third of the supply disruptions caused drug shortages, meaning there was a need to switch to another (generic) therapeutic alternative. For most drug shortages, a Belgian generic medicine could be found. However in some cases, the alternative had to be ordered abroad or for some drug shortages, no alternative was available. Conclusion These exploratory results on time spent by hospital pharmacists on drug supply problems in Belgium highlight the economic impact of drug supply problems for hospital pharmacies. A fully reliable, daily updated list on the federal agencies websites would be a major help to hospital pharmacists. PMID:28350827

  5. Naturally Occurring Changes in Time Spent Watching Television Are Inversely Related to Frequency of Physical Activity during Early Adolescence

    ERIC Educational Resources Information Center

    Motl, Robert W.; McAuley, Edward; Birnbaum, Amanda S.; Lytle, Leslie A.

    2006-01-01

    In this longitudinal study, we examined the relationship between changes in time spent watching television and playing video games with frequency of leisure-time physical activity across a 2-year period among adolescent boys and girls (N=4594). Latent growth modelling indicated that a decrease in time spent watching television was associated with…

  6. Predictors of the Discrepancy between Time Needed and Time Spent in Learning among Boys Exhibiting Behavior Problems.

    ERIC Educational Resources Information Center

    Gettinger, Maribeth; Lyon, Mark A.

    1983-01-01

    Based on Carroll's model of school learning, this study sought to identify factors to help explain the discrepancy between time needed for learning and time actually spent in learning. Ninety-six boys were required to read and reread a passage until 100 percent accuracy was achieved on a criterion test. (Author/PN)

  7. Maternal employment, acculturation, and time spent in food-related behaviors among Hispanic mothers in the United States. Evidence from the American Time Use Survey.

    PubMed

    Sliwa, Sarah A; Must, Aviva; Peréa, Flavia; Economos, Christina D

    2015-04-01

    Employment is a major factor underlying im/migration patterns. Unfortunately, lower diet quality and higher rates of obesity appear to be unintended consequences of moving to the US. Changes in food preparation practices may be a factor underlying dietary acculturation. The relationships between employment, acculturation, and food-related time use in Hispanic families have received relatively little attention. We used cross-sectional data collected from Hispanic mothers (ages 18-65) with at least one child <13 years old participating in the 2003-2011 American Time Use Survey (n = 3622) to estimate the relationship between employment, acculturation (US-born vs. im/migrant), and time spent in food preparation and family dinner. Regression models were estimated separately for the employed and the non-working and were adjusted for Hispanic origin group, socio-demographic and household characteristics. Working an eight-hour day was associated with spending 38 fewer minutes in food preparation (-38.0 ± SE 4.8, p < 001). Although being US-born was associated with spending fewer minutes in food preparation, this relationship varied by origin group. Acculturation did not appear to modify the relationship between hours worked and time spent in food preparation or family dinner. Mothers who worked late hours spent less time eating the evening meal with their families (-9.8 ± SE 1.3). Although an eight-hour workday was associated with a significant reduction in food preparation time, an unexpected result is that, for working mothers, additional time spent in paid work is not associated with the duration of family dinner later that day.

  8. [Interactive effect of spent mushroom compost and rhamnolipids to enhance the efficiency of alfalfa remediation of aged PAHs contaminated soil].

    PubMed

    Zhang, Jing; Lin, Xian-Gui; Li, Xuan-Zhen; Yin, Rui

    2010-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of the most widespread organic pollutants, which distributed widely in soil and sediment. Pot experiment was conducted to improve efficiency of phytoremediation using alfalfa (Medicago sativa L.) in aged PAHs contaminated soil by introducing spent mushroom compost and rhamnolipids. Plant biomass, PAHs concentrations, number of soil microorganism, soil enzyme activity and soil microbial functional diversity were determined after 60 days of alfalfa growth. The results showed that within 60 days, removal ratio of PAHs in treatment of alfalfa alone (AL) reached to 14.43%, while removal ratio of PAHs in treatments of "GZ + RH0.5, + AL" and "GZ + RH1.0 + AL" reached to 32.64% and 36.95%, which were 115.45% and 156.06% higher than that of phytoremediation. Contrasted to the control, the treatment of "GZ + RH1.0 + AL" had more plant biomass than others, shoot and root dry weight were 1.05 g/pot and 0.20 g/pot, respectively. During the process of phytoremediation, the number of soil bacteria and fungi were greatly increased by "GZ + RH1.0 + AL" and reached to 31.37 x 10(6) CFU x g(-1) and 5.86 x 10(6) CFU x g(-1), especially the number of PAHs-degrading bacteria reached to 39.57 x 10(5) MPN x g(-1), which were 29 times more than control treatment and 4 times more than treatment of alfalfa alone (AL). Moreover, soil dehydrogenase activity and the functional diversity of soil microbial community were increased significantly by the treatment of "GZ + RH1.0 + AL", respectively. Therefore, interaction of spent mushroom compost and rhamnolipids to enhance the phytoremediation efficiency had satisfied results in removal aged PAHs from an agricultural soil, the feasibility of this method needed to be further proved by large-area scale field experiment.

  9. Time spent by people managing chronic obstructive pulmonary disease indicates biographical disruption.

    PubMed

    Jowsey, Tanisha; Yen, Laurann E; Bagheri, Nasser; McRae, Ian S

    2014-01-01

    Since Bury's 1982 proposal that chronic illness creates biographical disruption for those who are living with it, there has been no effort to quantitatively measure such disruption. "Biographical disruption" refers to the substantial and directive influence that chronic illness can have over the course of a person's life. Qualitative research and time use studies have demonstrated that people with chronic illnesses spend considerable amounts of time managing their health, and that these demands may change over time. This study was designed to measure the time that older people with chronic illnesses spend on selected health practices as one indicator of biographical disruption. We look specifically at the time use of people with chronic obstructive pulmonary disease (COPD). As part of a larger time use survey, a recall questionnaire was mailed to 3,100 members of Lung Foundation Australia in 2011. A total of 681 responses were received (22.0% response rate), 611 of which were from people with COPD. Descriptive analyses were undertaken on the amount of time spent on selected health-related activities including personal care, nonclinical health-related care, and activity relating to health services. Almost all people with COPD report spending some time each day on personal or home-based health-related tasks, with a median time of 15 minutes per day spent on these activities. At the median, people also report spending about 30 minutes per day exercising, 2.2 hours per month (the equivalent of 4.4 minutes per day) on nonclinical health-related activities, and 4.1 hours per month (equivalent to 8.2 minutes per day) on clinical activities. Excluding exercise, the median total time spent on health-related activities was 17.8 hours per month (or 35.6 minutes per day). For people in the top 10% of time use, the total amount of time was more than 64.6 hours per month (or 2.2 hours per day) excluding exercise, and 104 hours per month (or 3.5 hours per day) including exercise

  10. The effect of food environments on fruit and vegetable intake as modified by time spent at home: a cross-sectional study

    PubMed Central

    Chum, Antony; Farrell, Eddie; Vaivada, Tyler; Labetski, Anna; Selvaratnam, Inthuja; Larsen, Kristian; Pinter, Theresa; O'Campo, Patricia

    2015-01-01

    Objective There is a growing body of research that investigates how the residential neighbourhood context relates to individual diet. However, previous studies ignore participants’ time spent in the residential environment and this may be a problem because time-use studies show that adults’ time-use pattern can significantly vary. To better understand the role of exposure duration, we designed a study to examine ‘time spent at home’ as a moderator to the residential food environment-diet association. Design Cross-sectional observational study. Settings City of Toronto, Ontario, Canada. Participants 2411 adults aged 25–65. Primary outcome measure Frequency of vegetable and fruit intake (VFI) per day. Results To examine how time spent at home may moderate the relationship between residential food environment and VFI, the full sample was split into three equal subgroups—short, medium and long duration spent at home. We detected significant associations between density of food stores in the residential food environment and VFI for subgroups that spend medium and long durations at home (ie, spending a mean of 8.0 and 12.3 h at home, respectively—not including sleep time), but no associations exist for people who spend the lowest amount of time at home (mean=4.7 h). Also, no associations were detected in analyses using the full sample. Conclusions Our study is the first to demonstrate that time spent at home may be an important variable to identify hidden population patterns regarding VFI. Time spent at home can impact the association between the residential food environment and individual VFI. PMID:26044756

  11. Association Between Time Spent Interpreting, Level of Confidence and Accuracy of Screening Mammography

    PubMed Central

    Carney, Patricia A.; Bogart, Andy; Geller, Berta M.; Haneuse, Sebastian; Kerlikowske, Karla; Buist, Diana SM; Smith, Robert; Rosenberg, Robert; Yankaskas, Bonnie C.; Onega, Tracy; Miglioretti, Diana L.

    2013-01-01

    Purpose To examine the effect of time spent viewing images and level of confidence on a screening mammography test set on interpretive performance. Materials and Methods Radiologists from six mammography registries participated in the study and were randomized to interpret one of four test sets and complete 12 survey questions. Each test set had 109 cases of digitized four-view screening film-screen mammograms with prior comparison screening views. Viewing time for each case was defined as the cumulative time spent viewing all mammographic images before recording which visible feature, if any, was the “most significant finding”. Log-linear regression fit via GEE was used to test the effect of viewing time and level of confidence in the interpretation on test set sensitivity and false-positive rate. Results 119 radiologists completed a test set and contributed data on 11,484 interpretations. Radiologists spent more time viewing cases that had significant findings or for which they had less confidence in interpretation. Each additional minute of viewing time increased the probability of a true positive interpretation among cancer cases by 1.12 (95% CI: 1.06, 1.19, p<0.001), regardless of confidence in the assessment. Among radiologists who were ‘very confident’ in their assessment, each additional minute of viewing time increased the adjusted risk of a false positive interpretation among non-cancer cases by 1.42 (95% CI 1.21, 1.68), and this viewing-time effect diminished with decreasing confidence. Conclusions Longer interpretation times and higher levels of confidence in the interpretation are both associated with higher sensitivity and false positive rates in mammography screening. PMID:22451568

  12. Is time spent playing video games associated with mental health, cognitive and social skills in young children?

    PubMed Central

    Kovess-Masfety, Viviane; Keyes, Katherine; Hamilton, Ava; Hanson, Gregory; Bitfoi, Adina; Golitz, Dietmar; Koç, Ceren; Kuijpers, Rowella; Lesinskiene, Sigita; Mihova, Zlatka; Otten, Roy; Fermanian, Christophe; Pez, Ondine

    2016-01-01

    Background Video games are one of the favourite leisure activities of children; the influence on child health is usually perceived to be negative. The present study assessed the association between the amount of time spent playing video games and children mental health as well as cognitive and social skills. Methods Data were drawn from the School Children Mental Health Europe project conducted in six European Union countries (youth ages 6–11, n = 3195). Child mental health was assessed by parents and teachers using the Strengths and Difficulties Questionnaire and by children themselves with the Dominic Interactive. Child video game usage was reported by the parents. Teachers evaluated academic functioning. Multivariable logistic regressions were used. Results 20 % of the children played video games more than 5 h per week. Factors associated with time spent playing video games included being a boy, being older, and belonging to a medium size family. Having a less educated, single, inactive, or psychologically distressed mother decreased time spent playing video games. Children living in Western European countries were significantly less likely to have high video game usage (9.66 vs 20.49 %) though this was not homogenous. Once adjusted for child age and gender, number of children, mothers age, marital status, education, employment status, psychological distress, and region, high usage was associated with 1.75 times the odds of high intellectual functioning (95 % CI 1.31–2.33), and 1.88 times the odds of high overall school competence (95 % CI 1.44–2.47). Once controlled for high usage predictors, there were no significant associations with any child self-reported or mother- or teacher-reported mental health problems. High usage was associated with decreases in peer relationship problems [OR 0.41 (0.2–0.86) and in prosocial deficits (0.23 (0.07, 0.81)]. Conclusions Playing video games may have positive effects on young children. Understanding the mechanisms

  13. Radiological Danger of Disposed Spent Fuel at Different Time of Subsequent Storage

    SciTech Connect

    Gerasimov, A.S.; Bergelson, B.R.; Zaritskaya, T.S.; Kiselev, G.V.; Tikhomirov, G.V.

    2002-07-01

    Decay heat power and radiotoxicity of actinides and fission products extracted from spent uranium and uranium-plutonium nuclear fuel of VVER-1000 type reactors are calculated for storage during a time period of 100 000 years. Maximum permissible activity of nuclides in water were taken into account at calculations of a radiotoxicity. Radiotoxicity is important characteristics of radiological danger from the point of view of a leakage from the storage facility. Decay heat power is important for the heat removal system of the storage facility. (authors)

  14. Fathers' Involvement with Their Preschool-Age Children: How Fathers Spend Time with Their Children in Different Family Structures

    ERIC Educational Resources Information Center

    Halme, Nina; Astedt-Kurki, Paivi; Tarkka, Marja-Terttu

    2009-01-01

    The purpose of this study was to describe how fathers (n = 263) spent time with their preschool-age children and to compare it in different family structures. Data were gathered by structured questionnaires. The instrument included five categories of variables for the time spent: the quantity of time, physical activities, fathers' attitude towards…

  15. 75 FR 23821 - Final License Renewal Interim Staff Guidance LR-ISG-2009-01: Aging Management of Spent Fuel Pool...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ... Neutron-Absorbing Materials Other Than Boraflex; Notice of Availability AGENCY: Nuclear Regulatory... Interim Staff Guidance (LR-ISG), LR-ISG-2009-01, ``Aging Management of Spent Fuel Pool Neutron-Absorbing... loss of material and loss of neutron-absorbing capability of certain nuclear power plant spent...

  16. Unobtrusive in-home detection of time spent out-of-home with applications to loneliness and physical activity

    PubMed Central

    Austin, Daniel; Kaye, Jeffrey A.; Pavel, Misha; Hayes, Tamara L.

    2014-01-01

    Loneliness is a common condition in elderly associated with severe health consequences including increased mortality, decreased cognitive function, and poor quality of life. Identifying and assisting lonely individuals is therefore increasingly important—especially in the home setting—as the very nature of loneliness often makes it difficult to detect by traditional methods. One critical component in assessing loneliness unobtrusively is to measure time spent out-of-home, as loneliness often presents with decreased physical activity, decreased motor functioning, and a decline in activities of daily living, all of which may cause decreases in the amount of time spent outside the home. Using passive and unobtrusive in-home sensing technologies, we have developed a methodology for detecting time spent out-of-home based on logistic regression. Our approach was both sensitive (0.939) and specific (0.975) in detecting time out-of-home across over 41,000 epochs of data collected from 4 subjects monitored for at least 30 days each in their own homes. In addition to linking time spent out-of-home to loneliness (r=−0.44, p=0.011) as measured by the UCLA Loneliness Index, we demonstrate its usefulness in other applications such as uncovering general behavioral patterns of elderly and exploring the link between time spent out-of-home and physical activity (r=0.415, p=0.031), as measured by the Berkman Social Disengagement Index. PMID:25192570

  17. Time spent in housework and leisure: links with parents' physiological recovery from work.

    PubMed

    Saxbe, Darby E; Repetti, Rena L; Graesch, Anthony P

    2011-04-01

    Spouses' balancing of housework and leisure activities at home may affect their recovery from work. This paper reports on a study of everyday family life in which 30 dual-earner couples were tracked around their homes by researchers who recorded their locations and activities every 10 min. For women, the most frequently pursued activities at home were housework, communication, and leisure; husbands spent the most time in leisure activities, followed by communication and housework. Spouses differed in their total time at home and their proportion of time devoted to leisure and housework activities, with wives observed more often in housework and husbands observed more often in leisure activities. Both wives and husbands who devoted more time to housework had higher levels of evening cortisol and weaker afternoon-to-evening recovery. For wives, husbands' increased housework time also predicted stronger evening cortisol recovery. When both spouses' activities were entered in the same model, leisure predicted husbands' evening cortisol, such that husbands who apportioned more time to leisure, and whose wives apportioned less time to leisure, showed stronger after-work recovery. These results suggest that the division of labor within couples may have implications for physical health.

  18. Data Mining Techniques to Estimate Plutonium, Initial Enrichment, Burnup, and Cooling Time in Spent Fuel Assemblies

    SciTech Connect

    Trellue, Holly Renee; Fugate, Michael Lynn; Tobin, Stephen Joesph

    2015-03-19

    The Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and Arms Control (NPAC), National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE) has sponsored a multi-laboratory, university, international partner collaboration to (1) detect replaced or missing pins from spent fuel assemblies (SFA) to confirm item integrity and deter diversion, (2) determine plutonium mass and related plutonium and uranium fissile mass parameters in SFAs, and (3) verify initial enrichment (IE), burnup (BU), and cooling time (CT) of facility declaration for SFAs. A wide variety of nondestructive assay (NDA) techniques were researched to achieve these goals [Veal, 2010 and Humphrey, 2012]. In addition, the project includes two related activities with facility-specific benefits: (1) determination of heat content and (2) determination of reactivity (multiplication). In this research, a subset of 11 integrated NDA techniques was researched using data mining solutions at Los Alamos National Laboratory (LANL) for their ability to achieve the above goals.

  19. Time spent in hospital after liver transplantation: Effects of primary liver disease and comorbidity

    PubMed Central

    Tovikkai, Chutwichai; Charman, Susan C; Praseedom, Raaj K; Gimson, Alexander E; van der Meulen, Jan

    2016-01-01

    AIM To explore the effect of primary liver disease and comorbidities on transplant length of stay (TLOS) and LOS in later admissions in the first two years after liver transplantation (LLOS). METHODS A linked United Kingdom Liver Transplant Audit - Hospital Episode Statistics database of patients who received a first adult liver transplant between 1997 and 2010 in England was analysed. Patients who died within the first two years were excluded from the primary analysis, but a sensitivity analysis was also performed including all patients. Multivariable linear regression was used to evaluate the impact of primary liver disease and comorbidities on TLOS and LLOS. RESULTS In 3772 patients, the mean (95%CI) TLOS was 24.8 (24.2 to 25.5) d, and the mean LLOS was 24.2 (22.9 to 25.5) d. Compared to patients with cancer, we found that the largest difference in TLOS was seen for acute hepatic failure group (6.1 d; 2.8 to 9.4) and the largest increase in LLOS was seen for other liver disease group (14.8 d; 8.1 to 21.5). Patients with cardiovascular disease had 8.5 d (5.7 to 11.3) longer TLOS and 6.0 d (0.2 to 11.9) longer LLOS, compare to those without. Patients with congestive cardiac failure had 7.6 d longer TLOS than those without. Other comorbidities did not significantly increase TLOS nor LLOS. CONCLUSION The time patients spent in hospital varied according to their primary liver disease and some comorbidities. Time spent in hospital of patients with cancer was relatively short compared to most other indications. Cardiovascular disease and congestive cardiac failure were the comorbidities with a strong impact on increased LOS. PMID:28058226

  20. Time Well Spent: Eight Powerful Practices of Successful, Expanded-Time Schools

    ERIC Educational Resources Information Center

    Kaplan, Claire; Chan, Roy

    2012-01-01

    This report reshapes the field for expanded-time schools by outlining specific practices that can lead to dramatic increases in student achievement and preparation for success in college and the workforce. This report offers an in-depth examination of 30 expanded-time schools serving high-poverty populations with impressive track records of…

  1. Retrieval attempts enhance learning regardless of time spent trying to retrieve.

    PubMed

    Vaughn, Kalif E; Hausman, Hannah; Kornell, Nate

    2017-03-01

    Attempting to retrieve information from memory is an engaging cognitive activity. We predicted that people would learn more when they had spent more time attempting to retrieve. In experiments 1a and 1b, participants were shown trivia questions for 0, 5, 10, or 30 seconds and then the answer was revealed. They took a final test immediately or after 48 hours. Retrieval enhanced learning, but the length of the retrieval attempt had no effect (i.e., final test performance was equivalent in the 5-, 10-, and 30-second conditions and worse in the 0-second condition). During the initial retrieval attempt, more time did increase recall, suggesting that participants continued to engage in productive retrieval activities when given more time. Showing the answer for longer (7 versus 2 seconds) increased learning in Experiments 2a and 2b. Experiment 3 examined the effect of retrieval success and Experiment 4 replicated the results using different materials. These results have direct implications for current theories of retrieval.

  2. Robotic Spent Fuel Monitoring – It is time to improve old approaches and old techniques!

    SciTech Connect

    Tobin, Stephen Joseph; Dasari, Venkateswara Rao; Trellue, Holly Renee

    2016-12-13

    This report describes various approaches and techniques associated with robotic spent fuel monitoring. The purpose of this description is to improve the quality of measured signatures, reduce the inspection burden on the IAEA, and to provide frequent verification.

  3. Reducing time spent by junior doctors on call performing routine tasks at weekends

    PubMed Central

    Ibrahim, Wadah; Lin, Simeng

    2013-01-01

    At the Northern General Hospital, there are sixteen medical wards, spread over approximately half a mile. Weekend care for inpatients on these wards is provided by a team of four junior doctors, of different levels of training. We undertook a quality improvement project to reduce the amount of time junior doctors spent performing routine tasks at weekends. This may increase their available time for direct patient care. The study was performed over a period of nine weeks on two medical wards - Diabetes & Endocrine (W1) and Care of the Elderly Rehabilitation (W2). We monitored the bleeps received by the covering junior doctors during the weekend daytime shifts from the two study wards. We noted that a proportion of bleeps were routine tasks that could have been performed during weekday working hours. We also noted that W2 recorded fewer bleeps than W1 ward. This seemed to be because W2 batched junior doctors' jobs together. Firstly, we attempted to reduce the amount of routine work left undone each weekend. We provided a poster to remind Junior Doctors to complete such work during the week. Secondly, on W1 we replicated the job-batching system already in place on W2. A Doctors' Book was introduced in which nursing staff recorded the tasks that needed doing. This saved them from having to bleep the doctor repeatedly. The two changes resulted in a reduction in the number of bleeps generated by each ward and the number of visits required by the Junior Doctors to W1. Simple changes can reduce the amount of time junior doctors spend performing routine work at weekends. We implemented two such changes and achieved a reduction in the number of bleeps experienced by junior doctors and the number of times they had to return to one ward. PMID:26734161

  4. Relationships of Attitudes toward Homework and Time Spent on Homework to Course Outcomes: The Case of Foreign Language Learning

    ERIC Educational Resources Information Center

    Chang, Charles B.; Wall, Daniel; Tare, Medha; Golonka, Ewa; Vatz, Karen

    2014-01-01

    In previous studies of homework in core academic subjects, positive student attitudes toward homework were linked to higher achievement, whereas time spent on homework showed an inconsistent relationship with achievement. This study examined the generalizability of these findings to foreign language learning by analyzing 2,342 adult students'…

  5. Time Spent on Mathematics Instruction and Homework by Japanese and U.S. 13-Year-Old-Students. OERI Bulletin.

    ERIC Educational Resources Information Center

    Center for Education Statistics (ED/OERI), Washington, DC.

    The Second International Mathematics Study compared 13-year-old students from 20 countries in five mathematics content areas. Japanese students ranked first in all five areas. This report compares Japan and the United States on three factors potentially related to student performance on mathematics tests. These include: (1) time spent on…

  6. Does Time Spent Online Have an Influence on Student Performance? Evidence for a Large Business Studies Class

    ERIC Educational Resources Information Center

    Korkofingas, Con; Macri, Joseph

    2013-01-01

    This paper examines, using regression modelling, whether a statistically significant relationship exists between the time spent by a student using the course website and the student's assessment performance for a large third year university business forecasting course. We utilise the online tracking system in Blackboard, a web-based software…

  7. Group-Based Modeling of Time Spent in Structured Activity Trajectories from Middle Childhood into Early Adolescence

    ERIC Educational Resources Information Center

    Mata, Andrea D.; van Dulmen, Manfred H. M.

    2012-01-01

    This study investigated trajectories of time spent in structured activities from middle childhood to early adolescence by using data from the National Institute of Child Health & Human Development (NICHD) Study of Early Child Care. We used latent class growth analyses and identified five trajectories (stable low, increasing high, decreasing low,…

  8. 29 CFR 516.34 - Exemption from overtime pay for time spent by certain employees receiving remedial education...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... employees receiving remedial education pursuant to section 7(q) of the Act. 516.34 Section 516.34 Labor... employees receiving remedial education pursuant to section 7(q) of the Act. With respect to each employee exempt from the overtime pay requirements of the Act for time spent receiving remedial education...

  9. 29 CFR 516.34 - Exemption from overtime pay for time spent by certain employees receiving remedial education...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... employees receiving remedial education pursuant to section 7(q) of the Act. 516.34 Section 516.34 Labor... employees receiving remedial education pursuant to section 7(q) of the Act. With respect to each employee exempt from the overtime pay requirements of the Act for time spent receiving remedial education...

  10. 29 CFR 516.34 - Exemption from overtime pay for time spent by certain employees receiving remedial education...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... employees receiving remedial education pursuant to section 7(q) of the Act. 516.34 Section 516.34 Labor... employees receiving remedial education pursuant to section 7(q) of the Act. With respect to each employee exempt from the overtime pay requirements of the Act for time spent receiving remedial education...

  11. 29 CFR 516.34 - Exemption from overtime pay for time spent by certain employees receiving remedial education...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... employees receiving remedial education pursuant to section 7(q) of the Act. 516.34 Section 516.34 Labor... employees receiving remedial education pursuant to section 7(q) of the Act. With respect to each employee exempt from the overtime pay requirements of the Act for time spent receiving remedial education...

  12. Energy beyond food: foraging theory informs time spent in thermals by a large soaring bird.

    PubMed

    Shepard, Emily L C; Lambertucci, Sergio A; Vallmitjana, Diego; Wilson, Rory P

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered.

  13. Energy Beyond Food: Foraging Theory Informs Time Spent in Thermals by a Large Soaring Bird

    PubMed Central

    Shepard, Emily L. C.; Lambertucci, Sergio A.; Wilson, Rory P.

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered. PMID:22087301

  14. Flaw Stability Considering Residual Stress for Aging Management of Spent Nuclear Fuel Multiple-Purpose Canisters

    SciTech Connect

    Lam, Poh-Sang; Sindelar, Robert L.

    2016-04-28

    A typical multipurpose canister (MPC) is made of austenitic stainless steel and is loaded with spent nuclear fuel assemblies. Because heat treatment for stress relief is not required for the construction of the MPC, the canister is susceptible to stress corrosion cracking in the weld or heat affected zone regions under long-term storage conditions. Logic for flaw acceptance is developed should crack-like flaws be detected by Inservice Inspection. The procedure recommended by API 579-1/ASME FFS-1, Fitness-for-Service, is used to calculate the instability crack length or depth by failure assessment diagram. It is demonstrated that the welding residual stress has a strong influence on the results.

  15. Flaw Stability Considering Residual Stress for Aging Management of Spent Nuclear Fuel Multiple-Purpose Canisters

    DOE PAGES

    Lam, Poh-Sang; Sindelar, Robert L.

    2016-04-28

    A typical multipurpose canister (MPC) is made of austenitic stainless steel and is loaded with spent nuclear fuel assemblies. Because heat treatment for stress relief is not required for the construction of the MPC, the canister is susceptible to stress corrosion cracking in the weld or heat affected zone regions under long-term storage conditions. Logic for flaw acceptance is developed should crack-like flaws be detected by Inservice Inspection. The procedure recommended by API 579-1/ASME FFS-1, Fitness-for-Service, is used to calculate the instability crack length or depth by failure assessment diagram. It is demonstrated that the welding residual stress has amore » strong influence on the results.« less

  16. Development of flaw acceptance criteria for aging management of spent nuclear fuel multi-purpose canisters

    SciTech Connect

    Lam, Poh -Sang; Sindelar, Robert L.

    2015-03-09

    A typical multipurpose canister (MPC) is made of austenitic stainless steel and is loaded with spent nuclear fuel assemblies. The canister may be subject to service-induced degradation when it is exposed to aggressive atmospheric environments during a possibly long-term storage period if the permanent repository is yet to be identified and readied. Because heat treatment for stress relief is not required for the construction of an MPC, stress corrosion cracking may be initiated on the canister surface in the welds or in the heat affected zone. An acceptance criteria methodology is being developed for flaw disposition should the crack-like defects be detected by periodic in-service Inspection. The first-order instability flaw sizes has been determined with bounding flaw configurations, that is, through-wall axial or circumferential cracks, and part-through-wall long axial flaw or 360° circumferential crack. The procedure recommended by the American Petroleum Institute (API) 579 Fitness-for-Service code (Second Edition) is used to estimate the instability crack length or depth by implementing the failure assessment diagram (FAD) methodology. The welding residual stresses are mostly unknown and are therefore estimated with the API 579 procedure. It is demonstrated in this paper that the residual stress has significant impact on the instability length or depth of the crack. The findings will limit the applicability of the flaw tolerance obtained from limit load approach where residual stress is ignored and only ligament yielding is considered.

  17. Development of flaw acceptance criteria for aging management of spent nuclear fuel multiple-purpose canisters

    SciTech Connect

    Lam, P.; Sindelar, R.

    2015-03-09

    A typical multipurpose canister (MPC) is made of austenitic stainless steel and is loaded with spent nuclear fuel assemblies. The canister may be subject to service-induced degradation when it is exposed to aggressive atmospheric environments during a possibly long-term storage period if the permanent repository is yet to be identified and readied. Because heat treatment for stress relief is not required for the construction of an MPC, stress corrosion cracking may be initiated on the canister surface in the welds or in the heat affected zone. An acceptance criteria methodology is being developed for flaw disposition should the crack-like defects be detected by periodic In-service Inspection. The first-order instability flaw sizes has been determined with bounding flaw configurations, that is, through-wall axial or circumferential cracks, and part-through-wall long axial flaw or 360° circumferential crack. The procedure recommended by the American Petroleum Institute (API) 579 Fitness-for-Service code (Second Edition) is used to estimate the instability crack length or depth by implementing the failure assessment diagram (FAD) methodology. The welding residual stresses are mostly unknown and are therefore estimated with the API 579 procedure. It is demonstrated in this paper that the residual stress has significant impact on the instability length or depth of the crack. The findings will limit the applicability of the flaw tolerance obtained from limit load approach where residual stress is ignored and only ligament yielding is considered.

  18. Human mobility and time spent at destination: impact on spatial epidemic spreading.

    PubMed

    Poletto, Chiara; Tizzoni, Michele; Colizza, Vittoria

    2013-12-07

    Host mobility plays a fundamental role in the spatial spread of infectious diseases. Previous theoretical works based on the integration of network theory into the metapopulation framework have shown that the heterogeneities that characterize real mobility networks favor the propagation of epidemics. Nevertheless, the studies conducted so far assumed the mobility process to be either Markovian (in which the memory of the origin of each traveler is lost) or non-Markovian with a fixed traveling time scale (in which individuals travel to a destination and come back at a constant rate). Available statistics however show that the time spent by travelers at destination is characterized by wide fluctuations, ranging from a single day up to several months. Such varying length of stay crucially affects the chance and duration of mixing events among hosts and may therefore have a strong impact on the spread of an emerging disease. Here, we present an analytical and a computational study of epidemic processes on a complex subpopulation network where travelers have memory of their origin and spend a heterogeneously distributed time interval at their destination. Through analytical calculations and numerical simulations we show that the heterogeneity of the length of stay alters the expression of the threshold between local outbreak and global invasion, and, moreover, it changes the epidemic behavior of the system in case of a global outbreak. Additionally, our theoretical framework allows us to study the effect of changes in the traveling behavior in response to the infection, by considering a scenario in which sick individuals do not leave their home location. Finally, we compare the results of our non-Markovian framework with those obtained with a classic Markovian approach and find relevant differences between the two, in the estimate of the epidemic invasion potential, as well as of the timing and the pattern of its spatial spread. These results highlight the importance of

  19. Do Hours Spent Viewing Television at Ages 3 and 4 Predict Vocabulary and Executive Functioning at Age 5?

    ERIC Educational Resources Information Center

    Blankson, A. Nayena; O'Brien, Marion; Leerkes, Esther M.; Calkins, Susan D.; Marcovitch, Stuart D.

    2015-01-01

    We examined the impact of television viewing at ages 3 and 4 on vocabulary and at age 5 on executive functioning in the context of home learning environment and parental scaffolding. Children (N = 263) were seen in the lab when they were 3 years old and then again at ages 4 and 5. Parents completed measures assessing child television viewing and…

  20. The Influence of Time Spent in Outdoor Play on Daily and Aerobic Step Count in Costa Rican Children

    ERIC Educational Resources Information Center

    Morera Castro, Maria del Rocio

    2011-01-01

    The purpose of this study is to examine the influence of time spent in outdoor play (i.e., on weekday and weekend days) on daily (i.e., average step count) and aerobic step count (i.e., average moderate to vigorous physical activity [MVPA] during the weekdays and weekend days) in fifth grade Costa Rican children. It was hypothesized that: (a)…

  1. Breast Intensity-Modulated Radiation Therapy Reduces Time Spent With Acute Dermatitis for Women of All Breast Sizes During Radiation

    SciTech Connect

    Freedman, Gary M. Li Tianyu; Nicolaou, Nicos; Chen Yan; Ma, Charlie C.-M.; Anderson, Penny R.

    2009-07-01

    Purpose: To study the time spent with radiation-induced dermatitis during a course of radiation therapy for breast cancer in women treated with conventional or intensity-modulated radiation therapy (IMRT). Methods and Materials: The study population consisted of 804 consecutive women with early-stage breast cancer treated with breast-conserving surgery and radiation from 2001 to 2006. All patients were treated with whole-breast radiation followed by a boost to the tumor bed. Whole-breast radiation consisted of conventional wedged photon tangents (n = 405) earlier in the study period and mostly of photon IMRT (n = 399) in later years. All patients had acute dermatitis graded each week of treatment. Results: The breakdown of the cases of maximum acute dermatitis by grade was as follows: 3%, Grade 0; 34%, Grade 1; 61%, Grade 2; and 2%, Grade 3. The breakdown of cases of maximum toxicity by technique was as follows: 48%, Grade 0/1, and 52%, Grade 2/3, for IMRT; and 25%, Grade 0/1, and 75%, Grade 2/3, for conventional radiation therapy (p < 0.0001). The IMRT patients spent 82% of weeks during treatment with Grade 0/1 dermatitis and 18% with Grade 2/3 dermatitis, compared with 29% and 71% of patients, respectively, treated with conventional radiation (p < 0.0001). Furthermore, the time spent with Grade 2/3 toxicity was decreased in IMRT patients with small (p = 0.0015), medium (p < 0.0001), and large (p < 0.0001) breasts. Conclusions: Breast IMRT is associated with a significant decrease both in the time spent during treatment with Grade 2/3 dermatitis and in the maximum severity of dermatitis compared with that associated with conventional radiation, regardless of breast size.

  2. Time well spent: the duration of foster care and early adult labor market, educational, and health outcomes.

    PubMed

    Fallesen, Peter

    2013-12-01

    Individuals who spent time in foster care as children fare on average worse than non-placed peers in early adult life. Recent research on the effect of foster care placement on early adult life outcomes provides mixed evidence. Some studies suggest negative effects of foster care placement on early adult outcomes, others find null effects. This study shows that differences in the average duration of foster care stays explain parts of these discordant findings and then test how foster care duration shapes later life outcomes using administrative data on 7220 children. The children experienced different average durations of foster care because of differences in exposure to a reform. Later born cohorts spent on average 3 months longer in foster care than earlier born cohorts. Isolating exogenous variation in duration of foster care, the study finds positive effects of increased duration of foster care on income and labor market participation.

  3. Subjective Age in Early Adolescence: Relationships with Chronological Age, Pubertal Timing, Desired Age, and Problem Behaviors

    ERIC Educational Resources Information Center

    Hubley, Anita M.; Arim, Rubab G.

    2012-01-01

    Subjective age generally refers to the age that one feels. In a cross-sectional questionnaire study of 245 adolescents ages 10-14 years, we examined (a) whether, and when, a cross-over in subjective age occurs, (b) differences in subjective age among pubertal timing groups, (c) correlations between subjective age and each of desired age and five…

  4. Physical Activity, Sedentary Time and Physical Capability in Early Old Age: British Birth Cohort Study

    PubMed Central

    Cooper, Andrew J. M.; Simmons, Rebecca K.; Kuh, Diana; Brage, Soren; Cooper, Rachel

    2015-01-01

    Purpose To investigate the associations of time spent sedentary, in moderate-to-vigorous-intensity physical activity (MVPA) and physical activity energy expenditure (PAEE) with physical capability measures at age 60-64 years. Methods Time spent sedentary and in MVPA and, PAEE were assessed using individually calibrated combined heart rate and movement sensing among 1727 participants from the MRC National Survey of Health and Development in England, Scotland and Wales as part of a detailed clinical assessment undertaken in 2006-2010. Multivariable linear regression models were used to examine the cross-sectional associations between standardised measures of each of these behavioural variables with grip strength, chair rise and timed up-&-go (TUG) speed and standing balance time. Results Greater time spent in MVPA was associated with higher levels of physical capability; adjusted mean differences in each capability measure per 1standard deviation increase in MVPA time were: grip strength (0.477 kg, 95% confidence interval (CI): 0.015 to 0.939), chair rise speed (0.429 stands/min, 95% CI: 0.093 to 0.764), standing balance time (0.028 s, 95% CI: 0.003 to 0.053) and TUG speed (0.019 m/s, 95% CI: 0.011 to 0.026). In contrast, time spent sedentary was associated with lower grip strength (-0.540 kg, 95% CI: -1.013 to -0.066) and TUG speed (-0.011 m/s, 95% CI: -0.019 to -0.004). Associations for PAEE were similar to those for MVPA. Conclusion Higher levels of MVPA and overall physical activity (PAEE) are associated with greater levels of physical capability whereas time spent sedentary is associated with lower levels of capability. Future intervention studies in older adults should focus on both the promotion of physical activity and reduction in time spent sedentary. PMID:25961736

  5. The association of how time is spent during outpatient visits and patient satisfaction: are there racial differences?

    PubMed Central

    Harris-Haywood, Sonja; Sylvia-Bobiak, Sarah N.; Stange, Kurt C.; Flocke, Susan A.

    2007-01-01

    Both satisfaction with the physician and how time is spent in the patient-physician outpatient visit have been shown to differ between African-American and Caucasian patients. This study uses structural equation modeling to examine racial differences in the association between time use during the outpatient visit and patient satisfaction. This cross-sectional study employed direct observation of outpatient visits and surveys of 2,502 adult African-American and Caucasian outpatients visiting 138 primary care physicians in 84 family practices in Northeast Ohio. Patient satisfaction was measured using the Medical Outcome Study (MOS) nine-item Visit Rating Scale. Time use was assessed with the Davis Observation Code, which was used to classify every 20 seconds of a visit into 20 behavioral categories. No difference was found between African-American and Caucasian patients in the association between patient satisfaction with a physician and the time the physician spent chatting, planning treatment, providing health education, structuring the interaction, assessing health knowledge or answering patient questions. Patients were generally satisfied with their physicians, and no racial differences between Caucasians and African Americans were observed. Despite racial differences in how physicians spend time in the outpatient visit encounter, these differences are not associated with racial differences in patient satisfaction. Efforts to understand disparities in satisfaction should address areas other than how physicians allocate time in the physician-patient encounter. PMID:17913118

  6. Combined Effects of Time Spent in Physical Activity, Sedentary Behaviors and Sleep on Obesity and Cardio-Metabolic Health Markers: A Novel Compositional Data Analysis Approach.

    PubMed

    Chastin, Sebastien F M; Palarea-Albaladejo, Javier; Dontje, Manon L; Skelton, Dawn A

    2015-01-01

    The associations between time spent in sleep, sedentary behaviors (SB) and physical activity with health are usually studied without taking into account that time is finite during the day, so time spent in each of these behaviors are codependent. Therefore, little is known about the combined effect of time spent in sleep, SB and physical activity, that together constitute a composite whole, on obesity and cardio-metabolic health markers. Cross-sectional analysis of NHANES 2005-6 cycle on N = 1937 adults, was undertaken using a compositional analysis paradigm, which accounts for this intrinsic codependence. Time spent in SB, light intensity (LIPA) and moderate to vigorous activity (MVPA) was determined from accelerometry and combined with self-reported sleep time to obtain the 24 hour time budget composition. The distribution of time spent in sleep, SB, LIPA and MVPA is significantly associated with BMI, waist circumference, triglycerides, plasma glucose, plasma insulin (all p<0.001), and systolic (p<0.001) and diastolic blood pressure (p<0.003), but not HDL or LDL. Within the composition, the strongest positive effect is found for the proportion of time spent in MVPA. Strikingly, the effects of MVPA replacing another behavior and of MVPA being displaced by another behavior are asymmetric. For example, re-allocating 10 minutes of SB to MVPA was associated with a lower waist circumference by 0.001% but if 10 minutes of MVPA is displaced by SB this was associated with a 0.84% higher waist circumference. The proportion of time spent in LIPA and SB were detrimentally associated with obesity and cardiovascular disease markers, but the association with SB was stronger. For diabetes risk markers, replacing SB with LIPA was associated with more favorable outcomes. Time spent in MVPA is an important target for intervention and preventing transfer of time from LIPA to SB might lessen the negative effects of physical inactivity.

  7. Combined Effects of Time Spent in Physical Activity, Sedentary Behaviors and Sleep on Obesity and Cardio-Metabolic Health Markers: A Novel Compositional Data Analysis Approach

    PubMed Central

    Chastin, Sebastien F. M.; Palarea-Albaladejo, Javier; Dontje, Manon L.; Skelton, Dawn A.

    2015-01-01

    The associations between time spent in sleep, sedentary behaviors (SB) and physical activity with health are usually studied without taking into account that time is finite during the day, so time spent in each of these behaviors are codependent. Therefore, little is known about the combined effect of time spent in sleep, SB and physical activity, that together constitute a composite whole, on obesity and cardio-metabolic health markers. Cross-sectional analysis of NHANES 2005–6 cycle on N = 1937 adults, was undertaken using a compositional analysis paradigm, which accounts for this intrinsic codependence. Time spent in SB, light intensity (LIPA) and moderate to vigorous activity (MVPA) was determined from accelerometry and combined with self-reported sleep time to obtain the 24 hour time budget composition. The distribution of time spent in sleep, SB, LIPA and MVPA is significantly associated with BMI, waist circumference, triglycerides, plasma glucose, plasma insulin (all p<0.001), and systolic (p<0.001) and diastolic blood pressure (p<0.003), but not HDL or LDL. Within the composition, the strongest positive effect is found for the proportion of time spent in MVPA. Strikingly, the effects of MVPA replacing another behavior and of MVPA being displaced by another behavior are asymmetric. For example, re-allocating 10 minutes of SB to MVPA was associated with a lower waist circumference by 0.001% but if 10 minutes of MVPA is displaced by SB this was associated with a 0.84% higher waist circumference. The proportion of time spent in LIPA and SB were detrimentally associated with obesity and cardiovascular disease markers, but the association with SB was stronger. For diabetes risk markers, replacing SB with LIPA was associated with more favorable outcomes. Time spent in MVPA is an important target for intervention and preventing transfer of time from LIPA to SB might lessen the negative effects of physical inactivity. PMID:26461112

  8. 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

  9. Analytical calculation of the mean time spent by photons inside an absorptive inclusion embedded in a highly scattering medium.

    PubMed

    Chernomordik, Victor; Hattery, David W; Gannot, Israel; Zaccanti, Giovanni; Gandjbakhche, Amir

    2002-07-01

    The mean time spent by photons inside a nonlocalized optically abnormal embedded inclusion has been derived analytically. The accuracy of the results has been tested against Monte Carlo and experimental data. We show that for quantification of the absorption coefficient of absorptive inclusions, a corrective factor that takes into account the size of the inclusion is needed. This finding suggests that perturbation methods derived for very small inclusions which are used in inverse algorithms require a corrective factor to adequately quantify the differential absorption coefficient of nonlocalized targets embedded in optically turbid media.

  10. Time Perspective and Age: A Review of Age Associated Differences

    PubMed Central

    Laureiro-Martinez, Daniella; Trujillo, Carlos A.; Unda, Juliana

    2017-01-01

    We investigate the relationship between age and the five dimensions of time perspective measured by the Zimbardo Time Perspective Inventory (ZTPI) (past negative, past positive, present hedonistic, present fatalistic, and future). Time perspective is related to well-being, decision-making, level of development, and many other psychological issues. Hence, the existence of a systematic relationship between time perspective and age should be considered in all studies for which time is a relevant variable. However, no specific research about this has been conducted. We collected 407 papers that referenced the ZTPI between 2001 and 2015. From those, 72 studies met our inclusion criteria. They included 29,815 participants from 19 countries whose age spans most phases of adulthood (from 13.5 to 75.5 years, mean 28.7). We analyzed these studies adapting meta-analytical techniques. We found that present hedonistic and past negative dimensions are negatively related to aging with partial eta squared effect sizes of roughly 0.15. Our results have implications for the design of studies related to time as our findings highlight the importance of taking into account the differences associated with age. PMID:28261119

  11. Time Perspective and Age: A Review of Age Associated Differences.

    PubMed

    Laureiro-Martinez, Daniella; Trujillo, Carlos A; Unda, Juliana

    2017-01-01

    We investigate the relationship between age and the five dimensions of time perspective measured by the Zimbardo Time Perspective Inventory (ZTPI) (past negative, past positive, present hedonistic, present fatalistic, and future). Time perspective is related to well-being, decision-making, level of development, and many other psychological issues. Hence, the existence of a systematic relationship between time perspective and age should be considered in all studies for which time is a relevant variable. However, no specific research about this has been conducted. We collected 407 papers that referenced the ZTPI between 2001 and 2015. From those, 72 studies met our inclusion criteria. They included 29,815 participants from 19 countries whose age spans most phases of adulthood (from 13.5 to 75.5 years, mean 28.7). We analyzed these studies adapting meta-analytical techniques. We found that present hedonistic and past negative dimensions are negatively related to aging with partial eta squared effect sizes of roughly 0.15. Our results have implications for the design of studies related to time as our findings highlight the importance of taking into account the differences associated with age.

  12. Linking age, survival, and transit time distributions

    NASA Astrophysics Data System (ADS)

    Calabrese, Salvatore; Porporato, Amilcare

    2015-10-01

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

  13. UNDERSTANDING VARIABILITY IN TIME SPENT IN SELECTED LOCATIONS FOR 7-12 YEAR OLD CHILDREN

    EPA Science Inventory

    This paper summarizes a series of analyses of clustered, sequential activity/location data collected by Harvard University for 160 children aged 7-12 in Southern California (Geyh et al., 2000). The main purpose of the paper is to understand intra- and inter-variability in the ti...

  14. Fast-start strategy increases the time spent above 95 %VO2max during severe-intensity intermittent running exercise.

    PubMed

    de Aguiar, Rafael Alves; Turnes, Tiago; de Oliveira Cruz, Rogério Santos; Caputo, Fabrizio

    2013-04-01

    This study aimed to use the intermittent critical velocity (ICV) model to individualize intermittent exercise and analyze whether a fast-start strategy could increase the time spent at or above 95 %VO(2max) (t95VO(2max)) during intermittent exercise. After an incremental test, seven active male subjects performed three intermittent exercise tests until exhaustion at 100, 110, and 120 % of the maximal aerobic velocity to determine ICV. On three occasions, the subjects performed an intermittent exercise test until exhaustion at 105 % (IE105) and 125 % (IE125) of ICV, and at a speed that was initially set at 125 %ICV but which then decreased to 105 %ICV (IE125-105). The intermittent exercise consisted of repeated 30-s runs alternated with 15-s passive rest intervals. There was no difference between the predicted and actual Tlim for IE125 (300 ± 72 s and 284 ± 76 s) and IE105 (1,438 ± 423 s and 1,439 ± 518 s), but for IE125-105 the predicted Tlim underestimated the actual Tlim (888 ± 211 s and 1,051 ± 153 s, respectively). The t95VO(2max) during IE125-105 (289 ± 150 s) was significantly higher than IE125 (113 ± 40 s) and IE105 (106 ± 71 s), but no significant differences were found between IE125 and IE105. It can be concluded that predicting Tlim from the ICV model was affected by the fast-start protocol during intermittent exercise. Furthermore, fast-start protocol was able to increase the time spent at or above 95 %VO2max during intermittent exercise above ICV despite a longer total exercise time at IE105.

  15. The effects of deprivation on the time spent examining crime scenes and the recovery of DNA and fingerprints.

    PubMed

    Adderley, Richard; Bond, John W

    2008-01-01

    DNA and fingerprint identifications are now accepted as an integral part of the investigation of a wide range of criminal offences from burglary and auto crime to serious and major crime. Despite this, there is still much variation between U.K. police forces in the recovery of fingerprint and DNA material from crime scenes. Analysis of burglary and auto crime data for Northamptonshire, U.K., during a 3-year period has enabled an examination of the relationship between the deprivation of the neighborhood in which the crime was committed and the level of service provided by Crime Scene Examiners. The results indicate that the time spent examining a crime scene for forensic evidence is not affected by the deprivation of the neighborhood. Further, there is no statistical significance between deprivation and the recovery of fingerprints from the crime scene. The relationship between deprivation and DNA recovery is, however, statistically significant with DNA being recovered more frequently from less deprived neighborhoods.

  16. Nurses' daily life: gender relations from the time spent in hospital1

    PubMed Central

    Pereira, Audrey Vidal

    2015-01-01

    Objective: to analyze the everyday life of nurses through the sexual work division as well as through interdependence relations and the time in hospital. Method: quanti-qualitative study, based on the Time Use Survey and in Norbert Elias's Configuration Theory of Interdependencies. Daily shifts distribution record, directed by 42 participants - with self-confrontation - by interviews which drew dialogues on subjective aspects of the everyday experiences related to use of time, based on a job at a university hospital. The theoretical intake that founded data analysis was based on concepts of conflicts of interest, power struggles, sexual work division and polychronic-monochronic concepts - whether the work environment demands multitasking nurses or not. Results: time records allowed to observe differences between the groups studied, useful to identify conflicts, tensions, power struggles and gender inequalities in interviewees' everyday affairs that do not only affect physical and mental health, but also their way of life. Conclusion: the analytical path pointed out the need for public policies that promote equity in gender relations, keeping at sight the exercise of plural discourses and tolerant stances capable to respect differences between individual and collective time. PMID:26487146

  17. The Relationship between Students' Small Group Activities, Time Spent on Self-Study, and Achievement

    ERIC Educational Resources Information Center

    Kamp, Rachelle J. A.; Dolmans, Diana H. J. M.; van Berkel, Henk J. M.; Schmidt, Henk G.

    2012-01-01

    The purpose of this study was to investigate the relationship between the contributions students make to the problem-based tutorial group process as observed by their peers, self-study time and achievement. To that end, the Maastricht Peer Activity Rating Scale was administered to students participating in Problem-Based Learning tutorial groups.…

  18. Time Spent Caregiving and Help Received by Spouses and Adult Children of Brain-Impaired Adults.

    ERIC Educational Resources Information Center

    Enright, Robert B., Jr.

    1991-01-01

    Surveyed 233 family caregivers for brain-impaired adults. Spousal caregivers (both husbands and wives) devoted much time to caregiving. Most caregivers received little assistance from other family members and friends, but husbands received more than others. Employed spouses received more paid help than unemployed spouses; employment did not affect…

  19. The Relation between the Time Mothers and Children Spent Together and the Children's Trait Emotional Intelligence

    ERIC Educational Resources Information Center

    Alegre, Albert

    2012-01-01

    Background: Parenting practices have been shown to predict children's emotional intelligence. The time that mothers and children spend in joint activity is an important aspect of the parent-child relationship, and it has been found to be influential in different domains of children's development. However, it has not been investigated in relation…

  20. Bullying Behavior, Parents' Work Hours and Early Adolescents' Perceptions of Time Spent with Parents

    ERIC Educational Resources Information Center

    Christie-Mizell, C. Andre; Keil, Jacqueline M.; Laske, Mary Therese; Stewart, Jennifer

    2011-01-01

    This research investigates the relationships among bullying behavior, mother's and father's work hours, and early adolescents' perceptions of whether they spend sufficient time with their parents. In cross-sectional models, we find maternal work hours are modestly associated with increases in bullying behavior. However, in more rigorous change…

  1. Age, Innovations and Time Operator of Networks

    NASA Astrophysics Data System (ADS)

    Gialampoukidis, Ilias; Antoniou, Ioannis

    2015-08-01

    We extend the Time Operator and Age to Network Evolution models. Internal Age formulas and the distribution of innovations are computed for Erdős-Rényi Random Networks, for Markov Networks and Barabási-Albert preferential Attachment Networks. The innovation probabilities are found to be proportional to the quadratic entropy (which coincides with the Tsallis entropy for entropic index q = 2) in all Markov networks, as well as in the linear growth mechanism. The distribution of innovations in the Barabási-Albert model is a new probability distribution of the logarithmic type.

  2. Average time spent by Lévy flights and walks on an interval with absorbing boundaries.

    PubMed

    Buldyrev, S V; Havlin, S; Kazakov, A Y; da Luz, M G; Raposo, E P; Stanley, H E; Viswanathan, G M

    2001-10-01

    We consider a Lévy flyer of order alpha that starts from a point x(0) on an interval [O,L] with absorbing boundaries. We find a closed-form expression for the average number of flights the flyer takes and the total length of the flights it travels before it is absorbed. These two quantities are equivalent to the mean first passage times for Lévy flights and Lévy walks, respectively. Using fractional differential equations with a Riesz kernel, we find exact analytical expressions for both quantities in the continuous limit. We show that numerical solutions for the discrete Lévy processes converge to the continuous approximations in all cases except the case of alpha-->2, and the cases of x(0)-->0 and x(0)-->L. For alpha>2, when the second moment of the flight length distribution exists, our result is replaced by known results of classical diffusion. We show that if x(0) is placed in the vicinity of absorbing boundaries, the average total length has a minimum at alpha=1, corresponding to the Cauchy distribution. We discuss the relevance of this result to the problem of foraging, which has received recent attention in the statistical physics literature.

  3. Lead Slowing-Down Spectrometry Time Spectral Analysis for Spent Fuel Assay: FY12 Status Report

    SciTech Connect

    Kulisek, Jonathan A.; Anderson, Kevin K.; Casella, Andrew M.; Siciliano, Edward R.; Warren, Glen A.

    2012-09-28

    .g. Pb stack size, neutron source location) of an LSDS for the purpose of assaying used fuel assemblies. Sensitivity studies were conducted that provide insight as to how the LSDS instrument can be improved by making it more sensitive to the center of the fuel assemblies. In FY2013, PNNL will continue efforts to develop and refine design requirements of an LSDS for the ultimate purpose of assaying used fuel assemblies. Future efforts will be directed toward more extensive experimental benchmarking of currently implemented time-spectra analysis algorithms.

  4. Aging, Spirituality, and Time: A Qualitative Study

    PubMed Central

    Black, Helen K.; Hannum, Susan M.

    2015-01-01

    We examined the concepts of aging, time, spirituality, and future care needs in four randomly selected informants from a group of 54 never-married childless older women. Using data from the Generativity and Lifestyles of Older Women (GLOW) study, we questioned how women’s perceptions of these concepts came together in current older age. We employed cultural theory, (our theoretical framework), ethnography, (our methodological framework), and phenomenology, (our philosophical foundation) to produce a portrait of each woman interviewed. Through a three-session interview process, we elicited the women’s life stories, reasons for childlessness, and topics that emerged as significant to the women, including aging, a sense of time remaining, and spirituality. A key finding was that the context of each woman’s life, both biographical and historical, transpired as a foundation for these concepts. That is, a woman’s “place in time” shaped their experiences of aging, as well as her reasons for childlessness and perceptions of finitude. PMID:26539067

  5. Time spent on professional activities and unwaged domestic work. Is it different for male and female primary care physicians who have children at home?

    PubMed Central

    Woodward, C. A.; Williams, A. P.; Ferrier, B.; Cohen, M.

    1996-01-01

    OBJECTIVE: To examine how having children affects the hours spent by male and female family physicians on professional activities and on unwaged domestic work. DESIGN: Survey fielded between September 1993 and February 1994. SETTING: Ontario. PARTICIPANTS: All Ontario-based physicians certificated by the College of Family Physicians of Canada between 1989 and 1991 after completing a family medicine residency. MAIN OUTCOME MEASURES: Self-reported hours spent per week on professional activities and unwaged domestic work. RESULTS: Response rate was 70%; men and women were equally likely to respond. About half (47.7%) had children at home. Women with children at home spent fewer hours on professional activities (P < 0.001) than men with children, whose hours of professional activity were similar to hours of men without children. Both women and men with children reported spending more time on household maintenance than did those without children. Among physicians with children, although men spent time on child care (mean time 11.4 hours; SD 11), women spent much more time on it (mean time 39.7 hours; SD 21; P < 0.001). The women worked an average of 90.5 hours per week in professional and unwaged activities; men averaged 68.6 hours. Childless physicians worked fewer hours: men 54.1, women 52.6. CONCLUSIONS: Female physicians with children at home spend more time on child care and household maintenance than their male partners. These responsibilities reduce professional work time (at least until all children are at school full time) and might deter women from active involvement in professional organizations. PMID:8894239

  6. Geologic time: The age of the Earth

    USGS Publications Warehouse

    Newman, William L.

    1977-01-01

    The Earth is very old 4 1/2 billion years or more according to recent estimates. This vast span of time, called geologic time by earth scientists and believed by some to reach back to the birth of the Solar System, is difficult if not impossible to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and man's centuries-old search for the key led to the beginning and nourished the growth of geologic science.

  7. An influential factor for external radiation dose estimation for residents after the Fukushima Daiichi Nuclear Power Plant accident-time spent outdoors for residents in Iitate Village.

    PubMed

    Ishikawa, Tetsuo; Yasumura, Seiji; Ohtsuru, Akira; Sakai, Akira; Akahane, Keiichi; Yonai, Shunsuke; Sakata, Ritsu; Ozasa, Kotaro; Hayashi, Masayuki; Ohira, Tetsuya; Kamiya, Kenji; Abe, Masafumi

    2016-06-01

    Many studies have been conducted on radiation doses to residents after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Time spent outdoors is an influential factor for external dose estimation. Since little information was available on actual time spent outdoors for residents, different values of average time spent outdoors per day have been used in dose estimation studies on the FDNPP accident. The most conservative value of 24 h was sometimes used, while 2.4 h was adopted for indoor workers in the UNSCEAR 2013 report. Fukushima Medical University has been estimating individual external doses received by residents as a part of the Fukushima Health Management Survey by collecting information on the records of moves and activities (the Basic Survey) after the accident from each resident. In the present study, these records were analyzed to estimate an average time spent outdoors per day. As an example, in Iitate Village, its arithmetic mean was 2.08 h (95% CI: 1.64-2.51) for a total of 170 persons selected from respondents to the Basic Survey. This is a much smaller value than commonly assumed. When 2.08 h is used for the external dose estimation, the dose is about 25% (23-26% when using the above 95% CI) less compared with the dose estimated for the commonly used value of 8 h.

  8. The Role of Parental Support, Parental Monitoring, and Time Spent with Parents in Adolescent Academic Achievement in Iceland: A Structural Model of Gender Differences

    ERIC Educational Resources Information Center

    Kristjansson, Alfgeir Logi; Sigfusdottir, Inga Dora

    2009-01-01

    This study examines the relationship between parental support, parental monitoring, and time spent with parents and academic achievement among adolescent girls and boys in Iceland, a high-income per-capita Nordic country. The indirect role of school effort is also examined. Data of 7430 9th and 10th graders is analyzed in the study. Structural…

  9. The Influence of Instructional Climates on Time Spent in Management Tasks and Physical Activity of 2nd-Grade Students during Physical Education

    ERIC Educational Resources Information Center

    Logan, Samuel W.; Robinson, Leah E.; Webster, E. Kipling; Rudisill, Mary E.

    2015-01-01

    The purpose of this study is to determine the effect of two physical education (PE) instructional climates (mastery, performance) on the percentage of time students spent in a) moderate-to-vigorous physical activity (MVPA) and b) management tasks during PE in 2nd-grade students. Forty-eight 2nd graders (mastery, n = 23; performance, n = 25)…

  10. The Relationship between Degree Type, Certification Status, and Years of Employment and the Amount of Time Spent on Rehabilitation Counseling Tasks in State--Federal Vocational Rehabilitation

    ERIC Educational Resources Information Center

    Lustig, Dan C.; Strauser, David R.

    2008-01-01

    The purpose of this study is to examine the relationship between perceived percentage of time spent on particular rehabilitation counseling responsibilities, on one hand, and possession of an educational degree, certification as a rehabilitation counselor (CRC), and years worked for the state--federal vocational rehabilitation (VR) agency, on the…

  11. Are children living on dead-end streets more active? Near-home street patterns and school-going children's time spent outdoors in Dhaka, Bangladesh.

    PubMed

    Monsur, Muntazar; Mansur, Mohaimen; Islam, Mohammed Zakiul

    2016-12-06

    This study aimed to investigate relationships between near-home street patterns and children's time spent outdoors (TSO). Participants were 60 (n=60) school-age Dhaka children, 7-11years old (16 girls and 44 boys) selected by a two-phase cluster sampling method. Data were collected from September 2010 to June 2011 by visiting each of 60 children's homes. Children's mean TSOs (in minutes) were reported by parents' face-to-face interviews, and near-home street pattern data were collected by systematic direct observations. The researchers also collected data on seven socio-demographic variables and three neighborhood built-environment variables. A backward selection based multiple linear regression was used to examine association between children's TSO and near-home street patterns. Results (adjusted R(2)=0.66 for weekdays and 0.68 for weekend) suggested that children's TSO were significantly associated with near-home street type: dead-end instead of through streets (28min on weekdays, p<0.01 and 66min on weekend, p<0.01). The width of the street, level of its branching and availability of an open space or playground near the house are also positively associated with TSO. Near-home street features significantly contribute to TSO in school-going children of Dhaka.

  12. The relationship between objective sperm competition risk and men's copulatory interest is moderated by partner's time spent with other men.

    PubMed

    Pham, Michael N; Shackelford, Todd K

    2013-12-01

    Men who spend a greater proportion of time apart from their female partner since the couple's last copulation are at greater "objective" sperm competition risk. We propose a novel cue to sperm competition risk: the time she spends with her male friends. Four hundred and twenty men in a committed, heterosexual, sexual relationship completed a questionnaire. The results indicate that men at greater objective sperm competition risk report less time desired until the couple's next copulation, greater interest in copulating with their partner, and greater anger, frustration, and upset in response to their partner's sexual rejection, but only among men whose partner spends more time with her male friends. These results remain after controlling statistically for the participant's age and their partner's age. We discuss limitations of the current research, and discuss how research in human sperm competition can inform social issues, including men's partner-directed sexual coercion.

  13. 5 CFR 551.431 - Time spent on standby duty or in an on-call status.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work Special Situations... spent on standby duty is hours of work if, for work-related reasons, the employee is restricted by official order to a designated post of duty and is assigned to be in a state of readiness to perform...

  14. Reactivity and isotopic composition of spent PWR (pressurized-water-reactor) fuel as a function of initial enrichment, burnup, and cooling time

    SciTech Connect

    Cerne, S.P.; Hermann, O.W.; Westfall, R.M.

    1987-10-01

    This study presents the reactivity loss of spent PWR fuel due to burnup in terms of the infinite lattice multiplications factor, k/sub infinity/. Calculations were performed using the SAS2 and CSAS1 control modules of the SCALE system. The k/sub infinity/ values calculated for all combinations of six enrichments, seven burnups, and five cooling times. The results are presented as a primary function of enrichment in both tabular and graphic form. An equation has been developed to estimate the tabulated values of k/sub infinity/'s by specifying enrichment, cooling time, and burnup. Atom densities for fresh fuel, and spent fuel at cooling times of 2, 10, and 20 years are included. 13 refs., 8 figs., 8 tabs.

  15. Comparative analysis of LWR and FBR spent fuels for nuclear forensics evaluation

    SciTech Connect

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-06

    Some interesting issues are attributed to nuclide compositions of spent fuels from thermal reactors as well as fast reactors such as a potential to reuse as recycled fuel, and a possible capability to be manage as a fuel for destructive devices. In addition, analysis on nuclear forensics which is related to spent fuel compositions becomes one of the interesting topics to evaluate the origin and the composition of spent fuels from the spent fuel foot-prints. Spent fuel compositions of different fuel types give some typical spent fuel foot prints and can be estimated the origin of source of those spent fuel compositions. Some technics or methods have been developing based on some science and technological capability including experimental and modeling or theoretical aspects of analyses. Some foot-print of nuclear forensics will identify the typical information of spent fuel compositions such as enrichment information, burnup or irradiation time, reactor types as well as the cooling time which is related to the age of spent fuels. This paper intends to evaluate the typical spent fuel compositions of light water (LWR) and fast breeder reactors (FBR) from the view point of some foot prints of nuclear forensics. An established depletion code of ORIGEN is adopted to analyze LWR spent fuel (SF) for several burnup constants and decay times. For analyzing some spent fuel compositions of FBR, some coupling codes such as SLAROM code, JOINT and CITATION codes including JFS-3-J-3.2R as nuclear data library have been adopted. Enriched U-235 fuel composition of oxide type is used for fresh fuel of LWR and a mixed oxide fuel (MOX) for FBR fresh fuel. Those MOX fuels of FBR come from the spent fuels of LWR. Some typical spent fuels from both LWR and FBR will be compared to distinguish some typical foot-prints of SF based on nuclear forensic analysis.

  16. Comparative analysis of LWR and FBR spent fuels for nuclear forensics evaluation

    NASA Astrophysics Data System (ADS)

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-01

    Some interesting issues are attributed to nuclide compositions of spent fuels from thermal reactors as well as fast reactors such as a potential to reuse as recycled fuel, and a possible capability to be manage as a fuel for destructive devices. In addition, analysis on nuclear forensics which is related to spent fuel compositions becomes one of the interesting topics to evaluate the origin and the composition of spent fuels from the spent fuel foot-prints. Spent fuel compositions of different fuel types give some typical spent fuel foot prints and can be estimated the origin of source of those spent fuel compositions. Some technics or methods have been developing based on some science and technological capability including experimental and modeling or theoretical aspects of analyses. Some foot-print of nuclear forensics will identify the typical information of spent fuel compositions such as enrichment information, burnup or irradiation time, reactor types as well as the cooling time which is related to the age of spent fuels. This paper intends to evaluate the typical spent fuel compositions of light water (LWR) and fast breeder reactors (FBR) from the view point of some foot prints of nuclear forensics. An established depletion code of ORIGEN is adopted to analyze LWR spent fuel (SF) for several burnup constants and decay times. For analyzing some spent fuel compositions of FBR, some coupling codes such as SLAROM code, JOINT and CITATION codes including JFS-3-J-3.2R as nuclear data library have been adopted. Enriched U-235 fuel composition of oxide type is used for fresh fuel of LWR and a mixed oxide fuel (MOX) for FBR fresh fuel. Those MOX fuels of FBR come from the spent fuels of LWR. Some typical spent fuels from both LWR and FBR will be compared to distinguish some typical foot-prints of SF based on nuclear forensic analysis.

  17. Patient Perception of Enough Time Spent With Provider Is a Mechanism for Improving Women Veterans' Experiences With VA Outpatient Health Care.

    PubMed

    Trentalange, Mark; Bielawski, Mark; Murphy, Terrence E; Lessard, Katarzyna; Brandt, Cynthia; Bean-Mayberry, Bevanne; Maisel, Natalya C; Wright, Steven M; Allore, Heather; Skanderson, Melissa; Reyes-Harvey, Evelyn; Gaetano, Vera; Haskell, Sally; Bastian, Lori A

    2016-12-01

    We postulated that associations between two specific provider characteristics, class (nurse practitioner relative to physician) and primary care providers who are proficient and interested in women's health (designated women's provider relative to nondesignated) and overall satisfaction with provider, were mediated through women veterans' perception of enough time spent with the provider. A national patient experience survey was administered to 7,620 women veterans. Multivariable models of overall patient satisfaction with provider were compared with and without the proposed mediator. A structural equation model (SEM) of the mediation of the two provider characteristics was also evaluated. Without the mediator, associations of provider class and designation with overall patient satisfaction were significant. With the proposed mediator, these associations became nonsignificant. An SEM showed that the majority (>80%) of the positive associations between provider class and designation and the outcome were exerted through patient perception of enough time spent with provider. Higher ratings of overall satisfaction with provider exhibited by nurse practitioners and designated women's health providers were exerted through patient perception of enough time spent with provider. Future research should examine what elements of provider training can be developed to improve provider-patient communication and patient satisfaction with their health care.

  18. The effect of wheelchair propulsion style on changes in time spent in extreme wrist orientations after a bout of fatiguing propulsion.

    PubMed

    Zukowski, Lisa A; Hass, Chris J; Shechtman, Orit; Christou, Evangelos A; Tillman, Mark D

    2017-03-21

    This study compared how wheelchair propulsion styles affect changes in percentage of time spent in extreme wrist orientations, which have been associated with median nerve injury, after a fatiguing bout of propulsion. Twenty novice, non-disabled adult males learned arcing (ARC) and semicircular (SEMI) propulsion styles and utilised each to perform a wheelchair fatigue protocol. ARC and SEMI did not significantly differ in terms of changes after the fatigue protocol in percentage of time spent in extreme flexion/extension or radial/ulnar deviation at the push phase beginning or end. A pattern was observed, although not significant, of greater increases in percentage of time spent in extreme wrist extension and ulnar deviation during the push phase beginning and ulnar deviation during the push phase end while utilising SEMI relative to ARC. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles. Practitioner Summary: How wheelchair propulsion styles change with fatigue in terms of extreme wrist orientations was examined. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles and point towards the need for future research on individual differences utilising propulsion styles.

  19. Aliens and time in the machine age

    NASA Astrophysics Data System (ADS)

    Brake, Mark; Hook, Neil

    2006-12-01

    The 19th century saw sweeping changes for the development of astrobiology, both in the constituency of empirical science encroaching upon all aspects of life and in the evolution of ideas, with Lyell's Principles of Geology radically raising expectation of the true age of the Earth and the drama of Darwinism questioning biblically literalist accounts of natural history. This paper considers the popular culture spun on the crackling loom of the emergent aspects of astrobiology of the day: Edward Bulwer-Lytton's The Coming Race (1871), which foretold the race of the future, and satirist Samuel Butler's anticipation of machine intelligence, `Darwin Among the Machines', in his Erewhon (1872). Finally, we look at the way Darwin, Huxley and natural selection travelled into space with French astronomer Camille Flammarion's immensely popular Récits de l'infini (Stories of Infinity, 1872), and the social Darwinism of H.G. Wells' The Time Machine (1895) and The War of the Worlds (1898). These works of popular culture presented an effective and inspiring communication of science; their crucial discourse was the reducible gap between the new worlds uncovered by science and exploration and the fantastic strange worlds of the imagination. As such they exemplify a way in which the culture and science of popular astrobiology can be fused.

  20. Time/motion observations and dose analysis of reactor loading, transportation, and dry unloading of an overweight truck spent fuel shipment

    SciTech Connect

    Hostick, C.J.; Lavender, J.C.; Wakeman, B.H.

    1992-04-01

    This document presents observed activity durations and radiation dose analyses for an overweight truck shipment of pressurized water reactor (PWR) spent fuel from the Surry Power Station in Virginia to the Idaho National Engineering Laboratory. The shipment consisted of a TN-8L shipping cask carrying three 9-year-old PWR spent fuel assemblies. Handling times and dose analyses for at-reactor activities were completed by Virginia Electric and Power Company (Virginia Power) personnel. Observations of in-transit and unloading activities were made by Pacific Northwest Laboratory (PNL) personnel, who followed the shipment for approximately 2800 miles and observed cask unloading activities. In-transit dose estimates were calculated using dose rate maps provided by Virginia Power for a fully loaded TN-8L shipping cask. The dose analysis for the cask unloading operations is based on the observations of PNL personnel.

  1. Time and dose assessment of barge shipment and at-reactor handling of a CASTOR V/21 spent fuel storage cask

    SciTech Connect

    Hostick, C.J. ); Lavender, J.C. ); Wakeman, B.H. )

    1992-04-01

    This report contains the results of a time/motion analysis and a radiation dose assessment made during the receipt from barge transport and the loading of CAst iron cask for Storage and Transport Of Radioactive material (CASTOR) V/21 storage casks with spent nuclear fuel at the Surry Power Station in Virginia during 1987. The study was a cooperative effort between Pacific Northwest Laboratory (PNL) and Virginia Electric and Power Company (Virginia Power), and was funded by the US Department of Energy (DOE) Transportation Program Office. In this study, cask handling activities were tracked at the Surry Power Station, tracing the transfer of the empty spent fuel storage cask from an ocean-going vessel to a barge for river transport through the activities required to place the loaded storage cask at an at-reactor storage location.

  2. Application of ALARA principles to shipment of spent nuclear fuel

    SciTech Connect

    Greenborg, J.; Brackenbush, L.W.; Murphy, D.W. Burnett, R.A.; Lewis, J.R.

    1980-05-01

    The public exposure from spent fuel shipment is very low. In view of this low exposure and the perfect safety record for spent fuel shipment, existing systems can be considered satisfactory. On the other hand, occupational exposure reduction merits consideration and technology improvement to decrease dose should concentrate on this exposure. Practices that affect the age of spent fuel in shipment and the number of times the fuel must be shipped prior to disposal have the largest impact. A policy to encourage a 5-year spent fuel cooling period prior to shipment coupled with appropriate cask redesign to accommodate larger loads would be consistent with ALARA and economic principles. And finally, bypassing high population density areas will not in general reduce shipment dose.

  3. Time spent in outdoor activities in relation to myopia prevention and control: a meta-analysis and systematic review.

    PubMed

    Xiong, Shuyu; Sankaridurg, Padmaja; Naduvilath, Thomas; Zang, Jiajie; Zou, Haidong; Zhu, Jianfeng; Lv, Minzhi; He, Xiangui; Xu, Xun

    2017-03-02

    Outdoor time is considered to reduce the risk of developing myopia. The purpose is to evaluate the evidence for association between time outdoors and (1) risk of onset of myopia (incident/prevalent myopia); (2) risk of a myopic shift in refractive error and c) risk of progression in myopes only. A systematic review followed by a meta-analysis and a dose-response analysis of relevant evidence from literature was conducted. PubMed, EMBASE and the Cochrane Library were searched for relevant papers. Of the 51 articles with relevant data, 25 were included in the meta-analysis and dose-response analysis. Twenty-three of the 25 articles involved children. Risk ratio (RR) for binary variables and weighted mean difference (WMD) for continuous variables were conducted. Mantel-Haenszel random-effects model was used to pool the data for meta-analysis. Statistical heterogeneity was assessed using the I(2) test with I(2)  ≥ 50% considered to indicate high heterogeneity. Additionally, subgroup analyses (based on participant's age, prevalence of myopia and study type) and sensitivity analyses were conducted. A significant protective effect of outdoor time was found for incident myopia (clinical trials: risk ratio (RR) = 0.536, 95% confidence interval (CI) = 0.338 to 0.850; longitudinal cohort studies: RR = 0.574, 95% CI = 0.395 to 0.834) and prevalent myopia (cross-sectional studies: OR = 0.964, 95% CI = 0.945 to 0.982). With dose-response analysis, an inverse nonlinear relationship was found with increased time outdoors reducing the risk of incident myopia. Also, pooled results from clinical trials indicated that when outdoor time was used as an intervention, there was a reduced myopic shift of -0.30 D (in both myopes and nonmyopes) compared with the control group (WMD = -0.30, 95% CI = -0.18 to -0.41) after 3 years of follow-up. However, when only myopes were considered, dose-response analysis did not find a relationship between time outdoors and myopic

  4. Spent fuel behavior in dry storage

    NASA Astrophysics Data System (ADS)

    Johnson, A. B., Jr.; Pankaskie, P. J.; Gilbert, E. R.

    1982-02-01

    Dry storage is emerging as an attractive and timely alternative to complement wet storage, and assist utilities to meet interim storage needs. Spent fuel is handled and stored under dry conditions. Dry storage of irradiated Zircaloy clad fuel in metal casks, drywells, silos and vaults is demonstrated. Hot cell and laboratory studies also are underway to investigate specific phenomena related to cladding behavior in dry storage. A substantial fraction of the LWR spent fuel inventory has aged for relatively long times and has relatively low decay heats. This suggests that much of the fuel inventory can be stored at relatively low temperatures. Alternatively, rod consolidation of the older can be considered without exceeding maximum cladding temperatures.

  5. Premigration School Quality, Time Spent in the United States, and the Math Achievement of Immigrant High School Students.

    PubMed

    Bozick, Robert; Malchiodi, Alessandro; Miller, Trey

    2016-10-01

    Using a nationally representative sample of 1,189 immigrant youth in American high schools, we examine whether the quality of education in their country of origin is related to post-migration math achievement in the 9th grade. To measure the quality of their education in the country of origin, we use country-specific average test scores from two international assessments: the Programme for International Student Assessment (PISA) and the Trends in International Mathematics and Science Study (TIMSS). We find that the average PISA or TIMSS scores for immigrant youth's country of origin are positively associated with their performance on the 9th grade post-migration math assessment. We also find that each year spent in the United States is positively associated with performance on the 9th grade post-migration math assessment, but this effect is strongest for immigrants from countries with low PISA/TIMSS scores.

  6. Influence of work-interval intensity and duration on time spent at a high percentage of VO2max during intermittent supramaximal exercise.

    PubMed

    Wakefield, Benjamin R; Glaister, Mark

    2009-12-01

    The purpose of this study was to examine the effect of work-interval duration (WID) and intensity on the time spent at, or above, 95% VO2max (T95 VO2max) during intermittent bouts of supramaximal exercise. Over a 5-week period, 7 physically active men with a mean (+/-SD) age, height, body mass, and VO2max of 22 +/- 5 years, 181.5 +/- 5.6 cm, 86.4 +/- 11.4 kg, and 51.5 +/- 1.5 ml.kg-1.min-1, respectively, attended 7 testing sessions. After completing a submaximal incremental test on a treadmill to identify individual oxygen uptake/running velocity relationships, subjects completed a maximal incremental test to exhaustion to VO2max and subsequently (from the aforementioned relationship) the minimum velocity required to elicit VO2max (vVO2max). In a random order, subjects then carried out 3 intermittent runs to exhaustion at both 105% and 115% vVO2max. Each test used a different WID (20 s, 25 s, or 30 s) interspersed with 20-second passive recovery periods. Results revealed no significant difference in T95 vVO2max for intermittent runs at 105% versus 115% vVO2max (p = 0.142). There was, however, a significant effect (p < 0.001) of WID on T95 VO2max, with WIDs of 30 seconds enabling more time relative to WIDs of 20 seconds (p = 0.018) and 25 seconds (p = 0.009). Moreover, there was an interaction between intensity and duration such that the effect of WID was magnified at the lower exercise intensity (p = 0.046). In conclusion, despite a number of limitations, the results of this investigation suggest that exercise intensities of approximately 105% vVO2max combined with WIDs greater than 25 seconds provide the best way of optimizing T95 VO2max when using fixed 20-second stationary rest periods.

  7. Time to exhaustion and time spent at a high percentage of VO2max in severe intensity domain in children and adults.

    PubMed

    Leclair, Erwan; Mucci, Patrick; Borel, Benoit; Baquet, Georges; Carter, Helen; Berthoin, Serge

    2011-04-01

    The aim of the study was to compare time spent at a high percentage of VO2max (>90% of VO2max) (ts90%), time to achieve 90% of VO2max (ta90%), and time to exhaustion (TTE) for exercise in the severe intensity domain in children and adults. Fifteen prepubertal boys (10.3 ± 0.9 years) and 15 men (23.5 ± 3.6 years) performed a maximal graded exercise to determine VO2max, maximal aerobic power (MAP) and power at ventilatory threshold (PVTh). Then, they performed 4 constant load exercises in a random order at PVTh plus 50 and 75% of the difference between MAP and PVTh (PΔ50 and PΔ75) and 100 and 110% of MAP (P100 and P110). VO2max was continuously monitored. The P110 test was used to determine maximal accumulated oxygen deficit (MAOD). No significant difference was found in ta90% between children and adults. ts90% and TTE were not significantly different between children and adults for the exercises at PΔ50 and PΔ75. However, ts90% and TTE during P100 (p < 0.05 and p < 0.01, respectively) and P110 (p < 0.001) exercises were significantly shorter in children. Children had a significantly lower MAOD than adults (34.3 ± 9.4 ml · kg vs. 53.6 ± 11.1 ml · kg). A positive relationship (p < 0.05) was obtained between MAOD and TTE values during the P100 test in children. This study showed that only for intensities at, or higher than MAP, lower ts90% in children was linked to a reduced TTE, compared to adults. Shorter TTE in children can partly be explained by a lower anaerobic capacity (MAOD). These results give precious information about exercise intensity ranges that could be used in children's training sessions. Moreover, they highlight the implication of both aerobic and anaerobic processes in endurance performances in both populations.

  8. Learning style versus time spent studying and career choice: Which is associated with success in a combined undergraduate anatomy and physiology course?

    PubMed

    Farkas, Gary J; Mazurek, Ewa; Marone, Jane R

    2016-01-01

    The VARK learning style is a pedagogical focus in health care education. This study examines relationships of course performance vs. VARK learning preference, study time, and career plan among students enrolled in an undergraduate anatomy and physiology course at a large urban university. Students (n = 492) from the fall semester course completed a survey consisting of the VARK questionnaire, gender, academic year, career plans, and estimated hours spent per week in combined classroom and study time. Seventy-eight percent of students reported spending 15 or fewer hours per week studying. Study time and overall course score correlated significantly for the class as a whole (r = 0.111, P = 0.013), which was mainly due to lecture (r = 0.118, P = 0.009) performance. No significant differences were found among students grouped by learning styles. When corrected for academic year, overall course scores (mean ± SEM) for students planning to enter dentistry, medicine, optometry or pharmacy (79.89 ± 0.88%) were significantly higher than those of students planning to enter physical or occupational therapies (74.53 ± 1.15%; P = 0.033), as well as nurse/physician assistant programs (73.60 ± 1.3%; P = 0.040). Time spent studying was not significantly associated with either learning style or career choice. Our findings suggest that specific career goals and study time, not learning preferences, are associated with better performance among a diverse group of students in an undergraduate anatomy and physiology course. However, the extent to which prior academic preparation, cultural norms, and socioeconomic factors influenced these results requires further investigation.

  9. Learning style versus time spent studying and career choice: Which is associated with success in a combined undergraduate anatomy and physiology course?

    PubMed Central

    Farkas, Gary J.; Mazurek, Ewa; Marone, Jane R.

    2016-01-01

    The VARK learning style is a pedagogical focus in health care education. This study examines relationships of course performance vs. VARK learning preference, study time, and career plan among students enrolled in an undergraduate anatomy and physiology course at a large urban university. Students (n = 492) from the fall semester course completed a survey consisting of the VARK questionnaire, gender, academic year, career plans, and estimated hours spent per week in combined classroom and study time. Seventy-eight percent of students reported spending 15 or fewer hours per week studying. Study time and overall course score correlated significantly for the class as a whole (r = 0.111, P = 0.013), which was mainly due to lecture (r = 0.118, P = 0.009) performance. No significant differences were found among students grouped by learning styles. When corrected for academic year, overall course scores (mean ± SEM) for students planning to enter “medicines” (79.89 ± 0.88%) were significantly higher than those of students planning to enter physical/occupational therapies (74.53 ± 1.15%; P = 0.033), as well as nurse/physician assistant programs (73.60 ± 1.3%; P = 0.040). Time spent studying was not significantly associated with either learning style or career choice. Our findings suggest that specific career goals and study time, not learning preferences, are associated with better performance among a diverse group of students in an undergraduate anatomy/physiology course. However, the extent to which prior academic preparation, cultural norms, and socioeconomic factors influenced these results requires further investigation. PMID:26301828

  10. Off-Stream Watering Systems and Partial Barriers as a Strategy to Maximize Cattle Production and Minimize Time Spent in the Riparian Area.

    PubMed

    Rawluk, Ashley A; Crow, Gary; Legesse, Getahun; Veira, Douglas M; Bullock, Paul R; González, Luciano A; Dubois, Melanie; Ominski, Kim H

    2014-10-29

    A study was conducted in 2009 at two locations in Manitoba (Killarney and Souris), Canada to determine the impact of off-stream waterers (OSW) with or without natural barriers on (i) amount of time cattle spent in the 10 m buffer created within the riparian area, referred to as the riparian polygon (RP), (ii) watering location (OSW or stream), and (iii) animal performance measured as weight gain. This study was divided into three 28-day periods over the grazing season. At each location, the pasture-which ranged from 21.0 ha to 39.2 ha in size-was divided into three treatments: no OSW nor barriers (1CONT), OSW with barriers along the stream bank to deter cattle from watering at the stream (2BARR), and OSW without barriers (3NOBARR). Cattle in 2BARR spent less time in the RP in Periods 1 (p = 0.0002), 2 (p = 0.1116), and 3 (p < 0.0001) at the Killarney site compared to cattle in 3NOBARR at the same site. Cattle in 2BARR at the Souris site spent more time in the RP in Period 1 (p < 0.0001) and less time in Period 2 (p = 0.0002) compared to cattle in 3NOBARR. Cattle did use the OSW, but not exclusively, as watering at the stream was still observed. The observed inconsistency in the effectiveness of the natural barriers on deterring cattle from the riparian area between periods and locations may be partly attributable to the environmental conditions present during this field trial as well as difference in pasture size and the ability of the established barriers to deter cattle from using the stream as a water source. Treatment had no significant effect (p > 0.05) on cow and calf weights averaged over the summer period. These results indicate that the presence of an OSW does not create significant differences in animal performance when used in extensive pasture scenarios such as those studied within the present study. Whereas the barriers did not consistently discourage watering at the stream, the results provide some indication of the efficacy of the OSW as well as the

  11. A comment on the use of flushing time, residence time, and age as transport time scales

    USGS Publications Warehouse

    Monsen, N.E.; Cloern, J.E.; Lucas, L.V.; Monismith, Stephen G.

    2002-01-01

    Applications of transport time scales are pervasive in biological, hydrologic, and geochemical studies yet these times scales are not consistently defined and applied with rigor in the literature. We compare three transport time scales (flushing time, age, and residence time) commonly used to measure the retention of water or scalar quantities transported with water. We identify the underlying assumptions associated with each time scale, describe procedures for computing these time scales in idealized cases, and identify pitfalls when real-world systems deviate from these idealizations. We then apply the time scale definitions to a shallow 378 ha tidal lake to illustrate how deviations between real water bodies and the idealized examples can result from: (1) non-steady flow; (2) spatial variability in bathymetry, circulation, and transport time scales; and (3) tides that introduce complexities not accounted for in the idealized cases. These examples illustrate that no single transport time scale is valid for all time periods, locations, and constituents, and no one time scale describes all transport processes. We encourage aquatic scientists to rigorously define the transport time scale when it is applied, identify the underlying assumptions in the application of that concept, and ask if those assumptions are valid in the application of that approach for computing transport time scales in real systems.

  12. Influence of the aerobic fitness on time spent at high percentage of maximal oxygen uptake during a high-intensity intermittent running.

    PubMed

    Panissa, V L; Julio, U F; Pinto-E-Silva, C M; Andreato, L V; Schwartz, J; Franchini, E

    2014-12-01

    This study aimed to evaluate absolute and relative (%V.O2max) oxygen uptake (total, during effort and pause), and time spent above 90% of V.O2max during high-intensity intermittent running in subjects with different training status. Fourteen males were evaluated and divided (moderate and high aerobic power) according to their V.O2max obtained in an incremental treadmill test to volitional exhaustion. They were then submitted to high-intensity intermittent aerobic exercise (1 min:1 min at maximum velocity attained during the treadmill test, totalling 4 km). A Student's t test for independent data was conducted to identify differences between groups. The moderate aerobic power group spent more time above 90% V.O2max compared to the high aerobic power group (30.2 ±9.1%; 7.3±6%, respectively, P=0.001). Moreover, the moderate aerobic power group presented lower V.O2total (P=0.011), V.O2effort (P=0.007), higher V.O2total (%V.O2), V.O2effort (P<0.001), V.O2pause (V.O2max%) (P=0.006) compared with the high aerobic power group. There was no difference in V.O2pause between groups (P=0.091), the difference between V.O2 effort and pause was greater for the high aerobic power group compared with the moderate group (4.4±2.1; 7.8±2 mL.kg-1.min-1; P=0.009) and the difference between V.O2 effort and pause (%V.O2max) was not different between groups. To conclude, these results demonstrated that individuals with better aerobic fitness spent less time above 90% of the V.O2max and that this response can be due to better capacity to recover during the pause.

  13. [Time use in the daily life of aged women: an indicative method of the life style of population groups].

    PubMed

    Doimo, Leonice Aparecida; Derntl, Alice Moreira; do Lago, Olival Cardoso

    2008-01-01

    Time use research analyzes the multi-factorial aspects of aging. The purpose of this research was to describe time use within a group of 75 elderly women, 68,04 +/- 8,36 years old, based on their daily activities from waking up to going to sleep. The instruments used in the study were a cognition test (Clock Completion Test), a questionnaire for obtaining personal data and structured interviews (Time Diary) for obtaining information about the activities carried out on the day prior to the interview. The daily activities were decoded and classified by means of an international classification for time use studies, thus obtaining the profiles of the daily activities assigned to nine groups of main activities and their physical and social contexts. It was verified that the greater part of time was spent with mandatory activities (housework and personal care). Most of the free time was spent with passive leisure (TV watching) and little physical activity. Most of the activities were performed at home (physical context), and the elderly women used to live either with members of their family or alone (social context). Individual factors such as age, gender, educational level, marital status and socioeconomic level probably play a role in the time use patterns found.

  14. How do working-age people with disabilities spend their time? New evidence from the American Time Use Survey.

    PubMed

    Anand, Priyanka; Ben-Shalom, Yonatan

    2014-12-01

    We use the American Time Use Survey to examine the extent to which adults with disabilities-defined using both the new six-question sequence on disability and the traditional work-limitation question-spend more time on health-related activities and less time on other activities than those without disabilities. We find that men and women who both reported a work limitation and responded "yes" to any of the questions in the six-question disability sequence spend approximately 40 to 50 more minutes per week, respectively, on health-related activities. We also find that most working-age men and women who report a disability work fewer hours per day than men and women without disabilities. The largest difference is for men and women who report both types of disability; these individuals spend, on average, 5 fewer hours per day in paid work than men and women without disabilities. On average, most of the decrease in paid work time is offset by more time spent on leisure activities (defined as activities that provide direct utility, such as entertainment, social activities, attending recreational events, and general relaxation) and sleeping, which is likely due to these being default activities for individuals whose medical issues and environment constrain them from participating in other activities.

  15. Proof of concept experiments of the multi-isotope process monitor: An online, nondestructive, near real-time monitor for spent nuclear fuel reprocessing facilities

    NASA Astrophysics Data System (ADS)

    Orton, Christopher R.; Fraga, Carlos G.; Christensen, Richard N.; Schwantes, Jon M.

    2012-04-01

    Operators, national regulatory agencies and the IAEA will require the development of advanced technologies to efficiently control and safeguard nuclear material at increasingly large-scale nuclear recycling facilities. Ideally, the envisioned technologies would be capable of non-destructive, near real-time (NRT), autonomous process monitoring. This paper describes results from proof-of-principle experiments designed to test the multi-isotope process (MIP) monitor, a novel approach to monitoring and safeguarding reprocessing facilities. The MIP Monitor combines the detection of intrinsic gamma ray signatures emitted from process solutions with multivariate analysis to detect off-normal conditions in process streams nondestructively and in NRT. Commercial spent nuclear fuel of various irradiation histories was dissolved and separated using a PUREX-based batch solvent extraction. Extractions were performed at various nitric acid concentrations to mimic both normal and off-normal industrial plant operating conditions. Principal component analysis (PCA) was applied to the simulated gamma spectra to investigate pattern variations as a function of acid concentration, burnup and cooling time. Partial least squares (PLS) regression was applied to attempt to quantify both the acid concentration and burnup of the dissolved spent fuel during the initial separation stage of recycle. The MIP Monitor demonstrated sensitivity to induced variations of acid concentration, including the distinction of ±1.3 M variation from normal process conditions by way of PCA. Acid concentration was predicted using measurements from the organic extract and PLS resulting in predictions with <0.7 M relative error. Quantification of burnup levels from dissolved fuel spectra using PLS was demonstrated to be within 2.5% of previously measured values.

  16. Association of Environment and Policy Characteristics on Children’s Moderate-to-Vigorous Physical Activity and Time Spent Sedentary in Afterschool Programs

    PubMed Central

    Ajja, Rahma; Clennin, Morgan N.; Weaver, R. Glenn; Moore, Justin B.; Huberty, Jennifer L.; Ward, Dianne S.; Pate, Russell R.; Beets, Michael W.

    2014-01-01

    Background Afterschool programs (ASPs) are an important setting in which to promote children’s physical activity. This study examines the association of environmental and policy characteristics on the moderate-to-vigorous physical activity (MVPA) and sedentary behavior of children attending ASPs. Methods A total of 1,302 children attending 20 ASPs across South Carolina wore accelerometers (ActiGraph GT3X+) for up to 4 non-consecutive days. Policy-level characteristics were evaluated using the Healthy Afterschool Program Index-Physical Activity (HAPI-PA) scale. Physical activity space was measured using a measuring wheel (indoor, ft2) and GIS (outdoor, acres). The structure (free-play or organized) of activity opportunities, was evaluated via direct observation. Time spent in MVPA and sedentary, both indoors and outdoors, was estimated using accelerometry. Results For every 5000ft2 of utilized indoor activity space an additional 2.4 and 3.3 minutes/day of sedentary behavior was observed among boys and girls, respectively. A higher ratio of free-play to organized play was associated with higher indoor sedentary behavior among boys and girls (3.9 minutes/day and 10.0 minutes/day, respectively). For every one acre of outdoor activity space used, an additional 2.7 minutes/day of MVPA was observed for boys. A higher free-play to organized play ratio was associated with higher outdoor MVPA for boys and girls (4.4 and 3.4 minutes/day increase, respectively). Policy characteristics were unrelated to MVPA levels and time spent sedentary. Conclusion Findings indicate that policies and the size of activity space had limited influence on MVPA and sedentary behavior, suggesting that programmatic structure may be a more effective option to improve MVPA levels of children attending ASPs. PMID:25251100

  17. Reduction of start-up time through bioaugmentation process in microbial fuel cells using an isolate from dark fermentative spent media fed anode.

    PubMed

    Pandit, Soumya; Khilari, Santimoy; Roy, Shantonu; Ghangrekar, M M; Pradhan, Debabrata; Das, Debabrata

    2015-01-01

    An electrochemically active bacteria Pseudomonas aeruginosa IIT BT SS1 was isolated from a dark fermentative spent media fed anode, and a bioaugmentation technique using the isolated strain was used to improve the start-up time of a microbial fuel cell (MFC). Higher volumetric current density and lower start-up time were observed with the augmented system MFC-PM (13.7 A/m(3)) when compared with mixed culture MFC-M (8.72 A/m(3)) during the initial phase. This enhanced performance in MFC-PM was possibly due to the improvement in electron transfer ability by the augmented strain. However, pure culture MFC-P showed maximum volumetric current density (17 A/m(3)) due to the inherent electrogenic properties of Pseudomonas sp. An electrochemical impedance spectroscopic (EIS) study, along with matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) analysis, supported the influence of isolated species in improving the MFC performance. The present study indicates that the bioaugmentation strategy using the isolated Pseudomonas sp. can be effectively utilized to decrease the start-up time of MFC.

  18. The Cell Cycle: An Activity Using Paper Plates to Represent Time Spent in Phases of the Cell Cycle

    ERIC Educational Resources Information Center

    Scherer, Yvette D.

    2014-01-01

    In this activity, students are given the opportunity to combine skills in math and geometry for a biology lesson in the cell cycle. Students utilize the data they collect and analyze from an online onion-root-tip activity to create a paper-plate time clock representing a 24-hour cell cycle. By dividing the paper plate into appropriate phases of…

  19. Effects of dry aging of bone-in and boneless strip loins using two aging processes for two aging times.

    PubMed

    Degeer, S L; Hunt, M C; Bratcher, C L; Crozier-Dodson, B A; Johnson, D E; Stika, J F

    2009-12-01

    This experiment investigated the combined effects of two dry-aging methods (unpackaged and in a bag), two loin-cut styles (bone-in shell loins and boneless strip loins), and two aging times (21 and 28days) on the physical, chemical, sensory, and microbial properties of dry-aged beef. Sections from shell and strip loin were assigned randomly to be aged unpackaged or aged packaged in a bag with high moisture permeability. Weight losses increased with aging time. Shell loins lost more (P<0.05) weight during aging compared with strip loins; dry aging in a bag had less (P<0.05) weight loss than unpackaged aging. There were no differences (P>0.05) in any of the sensory traits between shell and strip loins or dry aging using a traditional method or in a bag. Dry aging in a bag creates positive effects on yields, no negative effects on product quality, and adds flexibility and control of the aging environment.

  20. Investigating the tradeoffs between spatial resolution and diffusion sampling for brain mapping with diffusion tractography: time well spent?

    PubMed

    Calabrese, Evan; Badea, Alexandra; Coe, Christopher L; Lubach, Gabriele R; Styner, Martin A; Johnson, G Allan

    2014-11-01

    Interest in mapping white matter pathways in the brain has peaked with the recognition that altered brain connectivity may contribute to a variety of neurologic and psychiatric diseases. Diffusion tractography has emerged as a popular method for postmortem brain mapping initiatives, including the ex-vivo component of the human connectome project, yet it remains unclear to what extent computer-generated tracks fully reflect the actual underlying anatomy. Of particular concern is the fact that diffusion tractography results vary widely depending on the choice of acquisition protocol. The two major acquisition variables that consume scan time, spatial resolution, and diffusion sampling, can each have profound effects on the resulting tractography. In this analysis, we determined the effects of the temporal tradeoff between spatial resolution and diffusion sampling on tractography in the ex-vivo rhesus macaque brain, a close primate model for the human brain. We used the wealth of autoradiography-based connectivity data available for the rhesus macaque brain to assess the anatomic accuracy of six time-matched diffusion acquisition protocols with varying balance between spatial and diffusion sampling. We show that tractography results vary greatly, even when the subject and the total acquisition time are held constant. Further, we found that focusing on either spatial resolution or diffusion sampling at the expense of the other is counterproductive. A balanced consideration of both sampling domains produces the most anatomically accurate and consistent results.

  1. Off-Stream Watering Systems and Partial Barriers as a Strategy to Maximize Cattle Production and Minimize Time Spent in the Riparian Area

    PubMed Central

    Rawluk, Ashley A.; Crow, Gary; Legesse, Getahun; Veira, Douglas M.; Bullock, Paul R.; González, Luciano A.; Dubois, Melanie; Ominski, Kim H.

    2014-01-01

    Simple Summary The implementation of off-stream waterers (OSW) may reduce the amount of time cattle spend in riparian areas, thus minimizing impacts such as removal of vegetation, soil compaction, and deterioration in water quality. Furthermore, when used with natural barriers as a partial exclusion method, these management strategies may offer a cost-effective alternative to completely excluding cattle via streambank fencing. This study was conducted to determine the impact of OSW and barriers on animal performance and watering behavior. The presence of OSW had no significant effect on cow and calf weights averaged over the grazing season. Although the results were not consistent over the periods and locations, the data provided some indication of the efficacy of the natural barriers on deterring cattle from the riparian area. Cattle watered at the OSW when available, but they did not use the OSW exclusively. The observed inconsistency may, in part, be attributed to the environmental conditions present during this field trial. Abstract A study was conducted in 2009 at two locations in Manitoba (Killarney and Souris), Canada to determine the impact of off-stream waterers (OSW) with or without natural barriers on (i) amount of time cattle spent in the 10 m buffer created within the riparian area, referred to as the riparian polygon (RP), (ii) watering location (OSW or stream), and (iii) animal performance measured as weight gain. This study was divided into three 28-day periods over the grazing season. At each location, the pasture—which ranged from 21.0 ha to 39.2 ha in size—was divided into three treatments: no OSW nor barriers (1CONT), OSW with barriers along the stream bank to deter cattle from watering at the stream (2BARR), and OSW without barriers (3NOBARR). Cattle in 2BARR spent less time in the RP in Periods 1 (p = 0.0002), 2 (p = 0.1116), and 3 (p < 0.0001) at the Killarney site compared to cattle in 3NOBARR at the same site. Cattle in 2BARR at the

  2. Time spent studying on a pre-registration nursing programme module: an exploratory study and implications for regulation.

    PubMed

    Snelling, Paul C; Lipscomb, Martin; Lockyer, Lesley; Yates, Sue; Young, Pat

    2010-11-01

    European Union (EU) regulations require that university programmes are of specified duration. Additional EU regulations apply specifically to university based nurse education, enacted in the UK by the Nursing and Midwifery Council (NMC). However, little is known about how much time student nurses spend on their studies. In this exploratory study, students undertaking a single module in the pre-registration diploma programme at an English university were asked to keep a log of learning activity for the duration of the module. Twenty-six students completed the log. These students achieved higher grades and attended more lectures than the average for the module. The mean study time was 128.4 h against a regulatory assumption that the module should take 200 h. More than half of the 26 students undertook paid work during the module run, though this work was not associated with poorer performance. Problems in regulation for course duration are discussed and it is suggested that undertaking a 4600 h course in 3 years is problematic. More research is required so that patterns of study can be better understood and student centred programmes meeting regulatory requirements developed.

  3. THE MULTI-ISOTOPE PROCESS (MIP) MONITOR: A NEAR-REAL-TIME, NON-DESTRUCTIVE, INDICATOR OF SPENT NUCLEAR FUEL REPROCESSING CONDITIONS

    SciTech Connect

    Schwantes, Jon M.; Orton, Christopher R.; Fraga, Carlos G.; Douglas, Matthew; Christensen, Richard

    2010-05-07

    Researchers from Pacific Northwest National Laboratory and The Ohio State University are working to develop a system for monitoring spent nuclear fuel reprocessing facilities on-line, non-destructively, and in near-real-time. This method, known as the Multi-Isotope Process (MIP) Monitor, is based upon the measurement of distribution patterns of a suite of indicator (radioactive) isotopes present within product and waste streams of a nuclear reprocessing facility. Signatures from these indicator isotopes are monitored on-line by gamma spectrometry and compared, in near-real-time, to patterns representing "normal" process conditions using multivariate pattern recognition software. By targeting gamma-emitting indicator isotopes, the MIP Monitor approach is compatible with the use of small, portable, high-resolution gamma detectors that may be easily deployed throughout an existing facility. In addition, utilization of a suite of radio-elements, including ones with multiple oxidation states, increases the likelihood that attempts to divert material via process manipulation would be detected. Proof-of-principle modeling exercises simulating changes in acid strength have been completed and the results are promising. Laboratory validation is currently under way and significant results are available. The latest experimental results, along with an overview of the method will be presented.

  4. MONITORING SPENT NUCLEAR FUEL REPROCESSING CONDITIONS NON-DESTRUCTIVELY AND IN NEAR-REAL-TIME USING THE MULTI-ISOTOPE PROCESS (MIP) MONITOR

    SciTech Connect

    Orton, Christopher R.; Fraga, Carlos G.; Douglas, Matthew; Christensen, Richard; Schwantes, Jon M.

    2010-05-07

    Researchers from Pacific Northwest National Laboratory and The Ohio State University are working to develop a system for monitoring spent nuclear fuel reprocessing facilities on-line, nondestructively, and in near-real-time. This method, known as the Multi-Isotope Process (MIP) Monitor, is based upon the measurement of distribution patterns of a suite of indicator (radioactive) isotopes present within product and waste streams of a nuclear reprocessing facility. Signatures from these indicator isotopes are monitored on-line by gamma spectrometry and compared, in near-real-time, to patterns representing "normal" process conditions using multivariate pattern recognition software. By targeting gamma-emitting indicator isotopes, the MIP Monitor approach is compatible with the use of small, portable, high-resolution gamma detectors that may be easily deployed throughout an existing facility. In addition, utilization of a suite of radio-elements, including ones with multiple oxidation states, increases the likelihood that attempts to divert material via process manipulation would be detected. Proof-of-principle modeling exercises simulating changes in acid strength have been completed and the results are promising. Laboratory testing is currently under way and significant results are available. Recent experimental results, along with an overview of the method are presented.

  5. Narayanaswamy’s 1971 aging theory and material time

    SciTech Connect

    Dyre, Jeppe C.

    2015-09-21

    The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy’s phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time. The paper concludes with suggestions for computer simulations that test for consequences of material-time translational invariance. One of these is the “unique-triangles property” according to which any three points on the system’s path form a triangle such that two side lengths determine the third; this is equivalent to the well-known triangular relation for time-autocorrelation functions of aging spin glasses [L. F. Cugliandolo and J. Kurchan, J. Phys. A: Math. Gen. 27, 5749 (1994)]. The unique-triangles property implies a simple geometric interpretation of out-of-equilibrium time-autocorrelation functions, which extends to aging a previously proposed framework for such functions in equilibrium [J. C. Dyre, e-print arXiv:cond-mat/9712222 (1997)].

  6. [Aging explosive detection using terahertz time-domain spectroscopy].

    PubMed

    Meng, Kun; Li, Ze-ren; Liu, Qiao

    2011-05-01

    Detecting the aging situation of stock explosive is essentially meaningful to the research on the capability, security and stability of explosive. Existing aging explosive detection techniques, such as scan microscope technique, Fourier transfer infrared spectrum technique, gas chromatogram mass spectrum technique and so on, are either not able to differentiate whether the explosive is aging or not, or not able to image the structure change of the molecule. In the present paper, using the density functional theory (DFT), the absorb spectrum changes after the explosive aging were calculated, from which we can clearly find the difference of spectrum between explosive molecule and aging ones in the terahertz band. The terahertz time-domain spectrum (THz-TDS) system as well as its frequency spectrum resolution and measured range are analyzed. Combined with the existing experimental results and the essential characters of the terahertz wave, the application of THz-TDS technique to the detection of aging explosive was demonstrated from the aspects of feasibility, veracity and practicability. On the base of that, the authors advance the new method of aging explosive detection using the terahertz time-domain spectrum technique.

  7. Determining initial enrichment, burnup, and cooling time of pressurized-water reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    SciTech Connect

    Favalli, Andrea; Vo, D.; Grogan, Brandon R.; Jansson, Peter; Liljenfeldt, Henrik; Mozin, Vladimir; Schwalbach, P.; Sjoland, A.; Tobin, Stephen J.; Trellue, Holly; Vaccaro, S.

    2016-02-26

    The purpose of the Next Generation Safeguards Initiative (NGSI)–Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity’s behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. Furthermore, the results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

  8. Determining initial enrichment, burnup, and cooling time of pressurized-water-reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    NASA Astrophysics Data System (ADS)

    Favalli, A.; Vo, D.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S. J.; Trellue, H.; Vaccaro, S.

    2016-06-01

    The purpose of the Next Generation Safeguards Initiative (NGSI)-Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity's behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

  9. Determining initial enrichment, burnup, and cooling time of pressurized-water reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    DOE PAGES

    Favalli, Andrea; Vo, D.; Grogan, Brandon R.; ...

    2016-02-26

    The purpose of the Next Generation Safeguards Initiative (NGSI)–Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuelmore » assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity’s behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. Furthermore, the results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.« less

  10. The Effect of High Versus Low Teacher Affect and Passive Versus Active Student Activity During Music Listening on Preschool Children's Attention, Piece Preference, Time Spent Listening, and Piece Recognition.

    ERIC Educational Resources Information Center

    Sims, Wendy L.

    1986-01-01

    Small-group listening lessons and subsequent individual posttests were used to judge 94 three- through five-year-old subjects' attention, paired-comparison piece preference, time spent listening, and piece recognition. Research procedures included a modified multiple baseline design and split-screen video taping of instructional sessions.…

  11. A study on the expulsion of iodine from spent-fuel solutions

    SciTech Connect

    Sakurai, Tsutomu; Takahashi, Akira; Ishikawa, Niroh

    1995-02-01

    During dissolution of spent nuclear fuels, some radioiodine remains in spent-fuel solutions. Its expulsion to dissolver off-gas is important to minimize iodine escape to the environment. In our current work, the iodine remaining in spent-fuel solutions varied from 0 to 10% after dissolution of spent PWR-fuel specimens (approximately 3 g each). The amount remaining probably was dependent upon the dissolution time required. The cause is ascribable to the increased nitrous acid concentration that results from NOx generated during dissolution. The presence of nitrous acid was confirmed spectrophotometrically in an NO-HNO{sub 3} system at 100{degrees}C. Experiments examining NOx concentration versus the quantity of iodine in a simulated spent-fuel solution indicate that iodine (I{minus}) in spent fuels is subjected to the following three reactions: (1) oxidation into I{sub 2} by nitric acid, (2) oxidation into I{sub 2} by nitrous acid arising from NOx, and (3) formation of colloidal iodine (AgI, PdI{sub 2}), the major iodine species in a spent-fuel solution. Reaction (2) competes with reaction (3) to control the quantity of iodine remaining in solution. The following two-step expulsion process to remove iodine from a spent-fuel solution was derived from these experiments: Step One - Heat spent-fuel solutions without NOx sparging. When aged colloidal iodine is present, an excess amount of iodate should be added to the solution. Step Two - Sparge the fuel solution with NOx while heating. Effect of this new method was confirmed by use of a spent PWR-fuel solution.

  12. Team Work: Time well Spent

    ERIC Educational Resources Information Center

    Moore Johnson, Susan; Reinhorn, Stefanie K.; Simon, Nicole S.

    2016-01-01

    Teachers in high-poverty schools often feel stressed and fatigued. We might expect that if we ask these teachers to take on even more work by meeting regularly in collaborative improvement teams, they will respond with skepticism, even resentment. But in a study of 83 teachers in six outstanding high-poverty schools, these researchers found the…

  13. Organ Type and Waiting Time

    MedlinePlus

    ... These include but are not limited to: age blood type medical urgency waiting time geographic distance between donor ... factors include tissue match between donor and candidate; blood type; blood antibody levels; length of time spent on ...

  14. Is It Time Well Spent? The Relationship between Time Management Behaviours, Perceived Effectiveness and Work-Related Morale and Distress in a University Context

    ERIC Educational Resources Information Center

    Kearns, Hugh; Gardiner, Maria

    2007-01-01

    Despite the high "guru-factor" in time management, few claims have been subjected to empirical investigation. This study tests the claims that people who manage their time well perceive themselves to be more effective and feel less stressed. University staff and students were utilized to investigate the relationship between time management related…

  15. Effect of aging time and temperature on the aging behavior in Sn containing AZ91 alloy

    NASA Astrophysics Data System (ADS)

    Kim, Jeong Kyun; Oh, Seung Hyun; Kim, Kang Cheol; Kim, Won Tae; Kim, Do Hyang

    2017-03-01

    Effects of aging temperature and time on the aging behavior in AZ91 alloy and Sn containing AZ91 alloy (AZT915) have been investigated in the present study. The mode of precipitation, i.e. discontinuous and continuous precipitation in both alloys is strongly affected by the aging temperature. At low aging temperature of 403 K, only discontinuous precipitation occurs at the grain boundaries, whereas at high aging temperatures of 573 and 623 K only continuous precipitation occurs inside the grains. At intermediate temperature range (443 or 498 K) both discontinuous and continuous precipitation reactions occur. In AZT915, the Mg2Sn particles at the grain boundary effectively reduce the available nucleation sites for discontinuous β precipitates, and slow down the movement of the grain boundary, resulting in suppression of discontinuous precipitation. In addition, increased local lattice strain by the presence of Sn in the α-Mg solid solution matrix accelerates the nucleation of the continuous precipitates at the early stage of aging treatment. Therefore, significantly higher peak hardness can be obtained within a shorter aging time in AZT915.

  16. Effect of aging time and temperature on the aging behavior in Sn containing AZ91 alloy

    NASA Astrophysics Data System (ADS)

    Kim, Jeong Kyun; Oh, Seung Hyun; Kim, Kang Cheol; Kim, Won Tae; Kim, Do Hyang

    2017-02-01

    Effects of aging temperature and time on the aging behavior in AZ91 alloy and Sn containing AZ91 alloy (AZT915) have been investigated in the present study. The mode of precipitation, i.e. discontinuous and continuous precipitation in both alloys is strongly affected by the aging temperature. At low aging temperature of 403 K, only discontinuous precipitation occurs at the grain boundaries, whereas at high aging temperatures of 573 and 623 K only continuous precipitation occurs inside the grains. At intermediate temperature range (443 or 498 K) both discontinuous and continuous precipitation reactions occur. In AZT915, the Mg2Sn particles at the grain boundary effectively reduce the available nucleation sites for discontinuous β precipitates, and slow down the movement of the grain boundary, resulting in suppression of discontinuous precipitation. In addition, increased local lattice strain by the presence of Sn in the α-Mg solid solution matrix accelerates the nucleation of the continuous precipitates at the early stage of aging treatment. Therefore, significantly higher peak hardness can be obtained within a shorter aging time in AZT915.

  17. Increase in the age of Olympic swimmers in modern times.

    PubMed

    Mazzilli, Facundo

    2016-11-25

    Mazzilli, F. Increase in the age of Olympic swimmers in modern times. Anecdotal data suggest an increase in the age of Olympic swimmers, but scientific studies in this regard are scarce, despite the importance for coaches of the confirmation of this increase in different styles. To ascertain the reality of this increase, the present study focused on the analysis of the data contained in the reports of the Internal Olympic Games Association, covering different events and styles throughout the history of the Games. Starting with the 1908 Games, a total of 806 swimmers (436 men and 370 women) were included in the study. Of them 137 men and 135 women had won two or more medals. Plots of the age of the swimmer at the time a gold, silver or bronze medal was granted versus year of competition elicited statistical significant increases in 3 events in men and 9 events in women. Interestingly, significant increases were regularly observed in the styles introduced in the sixties and a kind of V-shaped distribution was observed in some of the long established competitions, namely in the 100, 400 and 1500 m freestyle in men, where the point of inflexion seems to occur around 1960. Overall there is a continuing increase in the age of swimmers of ages over 24 years old mirrored by a decrease of those below 20 years and this is accompanied by the increased presence of swimmers that have won medals in 2 or 3 different Games.

  18. Scaling in a Continuous Time Model for Biological Aging

    NASA Astrophysics Data System (ADS)

    de Almeida, R. M. C.; Thomas, G. L.

    In this paper, we consider a generalization to the asexual version of Penna model for biological aging, where we take a continuous time limit. The genotype associated to each individual is an interval of real numbers over which Dirac δ-functions are defined, representing genetically programmed diseases to be switched on at defined ages of the individual life. We discuss two different continuous limits for the evolution equation and two different mutation protocols, to be implemented during reproduction. Exact stationary solutions are obtained and scaling properties are discussed.

  19. A Comparison of Variable Time-Compressed Speech and Normal Rate Speech Based on Time Spent and Performance in a Course Taught by Self-Instructional Methods

    ERIC Educational Resources Information Center

    Short, Sarah Harvey

    1977-01-01

    College students using variable rate controlled speech compressors as compared with normal speed tape recorders had an average time saving of 32 percent and an average grade increase of 4.2 points on post-test scores. (Author)

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

    NASA Astrophysics Data System (ADS)

    Rehfeld, K.; Kurths, J.

    2014-01-01

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

  1. Similarity estimators for irregular and age uncertain time series

    NASA Astrophysics Data System (ADS)

    Rehfeld, K.; Kurths, J.

    2013-09-01

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

  2. Remaining time and opportunities at work: Relationships between age, work characteristics, and occupational future time perspective.

    PubMed

    Zacher, Hannes; Frese, Michael

    2009-06-01

    The authors adapted the concept of future time perspective (FTP) to the work context and examined its relationships with age and work characteristics (job complexity and control). Structural equation modeling of data from 176 employees of various occupations showed that age is negatively related to 2 distinct dimensions of occupational FTP: remaining time and remaining opportunities. Work characteristics (job complexity and control) were positively related to remaining opportunities and moderated the relationship between age and remaining opportunities, such that the relationship became weaker with increasing levels of job complexity and control.

  3. Age, Time, and Decision Making: From Processing Speed to Global Time Horizons

    PubMed Central

    Löckenhoff, Corinna E.

    2013-01-01

    Time and time perceptions are integral to decision making because any meaningful choice is embedded in a temporal context and requires the evaluation of future preferences and outcomes. The present review examines the influence of chronological age on time perceptions and horizons and discusses implications for decision making across the life span. Time influences and interacts with decision making in multiple ways. Specifically, this review examines the following topic areas: (1) processing speed and decision time, (2) internal clocks and time estimation, (3) mental representations of future time and intertemporal choice, and (4) global time horizons. For each aspect, patterns of age differences and implications for decision strategies and quality are discussed. The conclusion proposes frameworks to integrate different lines of research and identifies promising avenues for future inquiry. PMID:22023567

  4. 10 CFR 72.240 - Conditions for spent fuel storage cask renewal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 72.240 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS C... report (FSAR) as required by § 72.248; (2) Time-limited aging analyses that demonstrate that...

  5. Effects of Age, Season, Gender and Urban-Rural Status on Time-Activity: Canadian Human Activity Pattern Survey 2 (CHAPS 2)

    PubMed Central

    Matz, Carlyn J.; Stieb, David M.; Davis, Karelyn; Egyed, Marika; Rose, Andreas; Chou, Benedito; Brion, Orly

    2014-01-01

    Estimation of population exposure is a main component of human health risk assessment for environmental contaminants. Population-level exposure assessments require time-activity pattern distributions in relation to microenvironments where people spend their time. Societal trends may have influenced time-activity patterns since previous Canadian data were collected 15 years ago. The Canadian Human Activity Pattern Survey 2 (CHAPS 2) was a national survey conducted in 2010–2011 to collect time-activity information from Canadians of all ages. Five urban and two rural locations were sampled using telephone surveys. Infants and children, key groups in risk assessment activities, were over-sampled. Survey participants (n = 5,011) provided time-activity information in 24-hour recall diaries and responded to supplemental questionnaires concerning potential exposures to specific pollutants, dwelling characteristics, and socio-economic factors. Results indicated that a majority of the time was spent indoors (88.9%), most of which was indoors at home, with limited time spent outdoors (5.8%) or in a vehicle (5.3%). Season, age, gender and rurality were significant predictors of time activity patterns. Compared to earlier data, adults reported spending more time indoors at home and adolescents reported spending less time outdoors, which could be indicative of broader societal trends. These findings have potentially important implications for assessment of exposure and risk. The CHAPS 2 data also provide much larger sample sizes to allow for improved precision and are more representative of infants, children and rural residents. PMID:24557523

  6. Circadian rhythms, time-restricted feeding, and healthy aging.

    PubMed

    Manoogian, Emily N C; Panda, Satchidananda

    2016-12-23

    Circadian rhythms optimize physiology and health by temporally coordinating cellular function, tissue function, and behavior. These endogenous rhythms dampen with age and thus compromise temporal coordination. Feeding-fasting patterns are an external cue that profoundly influence the robustness of daily biological rhythms. Erratic eating patterns can disrupt the temporal coordination of metabolism and physiology leading to chronic diseases that are also characteristic of aging. However, sustaining a robust feeding-fasting cycle, even without altering nutrition quality or quantity, can prevent or reverse these chronic diseases in experimental models. In humans, epidemiological studies have shown erratic eating patterns increase the risk of disease, whereas sustained feeding-fasting cycles, or prolonged overnight fasting, is correlated with protection from breast cancer. Therefore, optimizing the timing of external cues with defined eating patterns can sustain a robust circadian clock, which may prevent disease and improve prognosis.

  7. [Temporal ambivalences of aging: Individual patterns of time use in conflict between time wealth and time poverty].

    PubMed

    Münch, Anne

    2016-01-01

    Throughout their lives people are confronted with different time resources and demands that change continuously up into old age. With the help of a qualitative interview study the narrative constructions of subjective time experiences as well as individual ways of dealing with time in retirement were investigated. In particular the influences of older persons' experience of time within the dimensions of everyday time and life time were analyzed. In addition, the study focused on potential time conflicts between these two dimensions and the question of how older people deal with the ambivalence between everyday time wealth and biographical time poverty in older age. The results of the interviews with 50 retired men and women (aged 56-91 years) in Germany, which were analyzed with "grounded theory" techniques, indicated that time in retirement does not indeed always run smoothly. In particular, the individual perception of increasing biographical time poverty exerts pressure on the arrangement of activities and daily routine in retirement. The resulting time conflicts are reflected in differential patterns of time use through which older persons try to cope with their ambivalent time experiences.

  8. Time Perspective and Emotion Regulation as Predictors of Age-Related Subjective Passage of Time

    PubMed Central

    Wittmann, Marc; Rudolph, Tina; Linares Gutierrez, Damisela; Winkler, Isabell

    2015-01-01

    Hardly any empirical work exists concerning the relationship between the intra-individually stable time perspective relating to the past, present, and future and the subjective speed of time passing in everyday life. Moreover, studies consistently show that the subjective passage of time over the period of the last ten years speeds up as we get older. Modulating variables influencing this phenomenon are still unknown. To investigate these two unresolved issues, we conducted an online survey with n = 423 participants ranging in age between 17 and 81 assessing trait time perspective of the past, present, and future, and relating these subscales with a battery of measures pertaining to the subjective passage of time. Moreover, the subjective passage of time as an age-dependent variable was probed in relationship to emotion awareness, appraisal and regulation. Results show how present hedonism is linked with having fewer routines in life and a faster passage of the last week; the past negative perspective is related to time pressure, time expansion and more routine; a pronounced future perspective is related to a general faster passage of time. Importantly, increased emotion regulation and a balanced time perspective are related to a slower passage of the last ten years. These novel findings are discussed within models of time perception and the time perspective. PMID:26694439

  9. Time Perspective and Emotion Regulation as Predictors of Age-Related Subjective Passage of Time.

    PubMed

    Wittmann, Marc; Rudolph, Tina; Linares Gutierrez, Damisela; Winkler, Isabell

    2015-12-17

    Hardly any empirical work exists concerning the relationship between the intra-individually stable time perspective relating to the past, present, and future and the subjective speed of time passing in everyday life. Moreover, studies consistently show that the subjective passage of time over the period of the last ten years speeds up as we get older. Modulating variables influencing this phenomenon are still unknown. To investigate these two unresolved issues, we conducted an online survey with n = 423 participants ranging in age between 17 and 81 assessing trait time perspective of the past, present, and future, and relating these subscales with a battery of measures pertaining to the subjective passage of time. Moreover, the subjective passage of time as an age-dependent variable was probed in relationship to emotion awareness, appraisal and regulation. Results show how present hedonism is linked with having fewer routines in life and a faster passage of the last week; the past negative perspective is related to time pressure, time expansion and more routine; a pronounced future perspective is related to a general faster passage of time. Importantly, increased emotion regulation and a balanced time perspective are related to a slower passage of the last ten years. These novel findings are discussed within models of time perception and the time perspective.

  10. Generalized master equation via aging continuous-time random walks.

    PubMed

    Allegrini, Paolo; Aquino, Gerardo; Grigolini, Paolo; Palatella, Luigi; Rosa, Angelo

    2003-11-01

    We discuss the problem of the equivalence between continuous-time random walk (CTRW) and generalized master equation (GME). The walker, making instantaneous jumps from one site of the lattice to another, resides in each site for extended times. The sojourn times have a distribution density psi(t) that is assumed to be an inverse power law with the power index micro. We assume that the Onsager principle is fulfilled, and we use this assumption to establish a complete equivalence between GME and the Montroll-Weiss CTRW. We prove that this equivalence is confined to the case where psi(t) is an exponential. We argue that is so because the Montroll-Weiss CTRW, as recently proved by Barkai [E. Barkai, Phys. Rev. Lett. 90, 104101 (2003)], is nonstationary, thereby implying aging, while the Onsager principle is valid only in the case of fully aged systems. The case of a Poisson distribution of sojourn times is the only one with no aging associated to it, and consequently with no need to establish special initial conditions to fulfill the Onsager principle. We consider the case of a dichotomous fluctuation, and we prove that the Onsager principle is fulfilled for any form of regression to equilibrium provided that the stationary condition holds true. We set the stationary condition on both the CTRW and the GME, thereby creating a condition of total equivalence, regardless of the nature of the waiting-time distribution. As a consequence of this procedure we create a GME that is a bona fide master equation, in spite of being non-Markov. We note that the memory kernel of the GME affords information on the interaction between system of interest and its bath. The Poisson case yields a bath with infinitely fast fluctuations. We argue that departing from the Poisson form has the effect of creating a condition of infinite memory and that these results might be useful to shed light on the problem of how to unravel non-Markov quantum master equations.

  11. Gender and Age Differences in Hourly and Daily Patterns of Sedentary Time in Older Adults Living in Retirement Communities

    PubMed Central

    Bellettiere, John; Carlson, Jordan A.; Rosenberg, Dori; Singhania, Anant; Natarajan, Loki; Berardi, Vincent; LaCroix, Andrea Z.; Sears, Dorothy D.; Moran, Kevin; Crist, Katie; Kerr, Jacqueline

    2015-01-01

    Background Total sedentary time varies across population groups with important health consequences. Patterns of sedentary time accumulation may vary and have differential health risks. The purpose of this study is to describe sedentary patterns of older adults living in retirement communities and illustrate gender and age differences in those patterns. Methods Baseline accelerometer data from 307 men and women (mean age = 84±6 years) who wore ActiGraph GT3X+ accelerometers for ≥ 4 days as part of a physical activity intervention were classified into bouts of sedentary time (<100 counts per minute). Linear mixed models were used to account for intra-person and site-level clustering. Daily and hourly summaries were examined in mutually non-exclusive bouts of sedentary time that were 1+, 5+, 10+, 20+, 30+, 40+, 50+, 60+, 90+ and 120+ minutes in duration. Variations by time of day, age and gender were explored. Results Men accumulated more sedentary time than women in 1+, 5+, 10+, 20+, 30+, 40+, 50+ and 60+ minute bouts; the largest gender-differences were observed in 10+ and 20+ minute bouts. Age was positively associated with sedentary time, but only in bouts of 10+, 20+, 30+, and 40+ minutes. Women had more daily 1+ minute sedentary bouts than men (71.8 vs. 65.2), indicating they break up sedentary time more often. For men and women, a greater proportion of time was spent being sedentary during later hours of the day than earlier. Gender differences in intra-day sedentary time were observed during morning hours with women accumulating less sedentary time overall and having more 1+ minute bouts. Conclusions Patterns identified using bouts of sedentary time revealed gender and age differences in the way in which sedentary time was accumulated by older adults in retirement communities. Awareness of these patterns can help interventionists better target sedentary time and may aid in the identification of health risks associated with sedentary behavior. Future studies

  12. Circadian regulation of human sleep and age-related changes in its timing, consolidation and EEG characteristics

    NASA Technical Reports Server (NTRS)

    Dijk, D. J.; Duffy, J. F.

    1999-01-01

    The light-entrainable circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus regulates the timing and consolidation of sleep by generating a paradoxical rhythm of sleep propensity; the circadian drive for wakefulness peaks at the end of the day spent awake, ie close to the onset of melatonin secretion at 21.00-22.00 h and the circadian drive for sleep crests shortly before habitual waking-up time. With advancing age, ie after early adulthood, sleep consolidation declines, and time of awakening and the rhythms of body temperature, plasma melatonin and cortisol shift to an earlier clock hour. The variability of the phase relationship between the sleep-wake cycle and circadian rhythms increases, and in old age sleep is more susceptible to internal arousing stimuli associated with circadian misalignment. The propensity to awaken from sleep advances relative to the body temperature nadir in older people, a change that is opposite to the phase delay of awakening relative to internal circadian rhythms associated with morningness in young people. Age-related changes do not appear to be associated with a shortening of the circadian period or a reduction of the circadian drive for wake maintenance. These changes may be related to changes in the sleep process itself, such as reductions in slow-wave sleep and sleep spindles as well as a reduced strength of the circadian signal promoting sleep in the early morning hours. Putative mediators and modulators of circadian sleep regulation are discussed.

  13. Age at migration, family instability, and timing of sexual onset.

    PubMed

    Goldberg, Rachel E; Tienda, Marta; Adserà, Alícia

    2017-03-01

    This study builds on and extends previous research on nativity variations in adolescent health and risk behavior by addressing three questions: (1) whether and how generational status and age at migration are associated with timing of sexual onset among U.S. adolescents; (2) whether and how family instability mediates associations between nativity and sexual debut; and (3) whether and how these associations vary by gender. We find that first- and second-generation immigrant youth initiate sexual activity later than native youth. Foreign-born youth who migrate after the start of adolescence exhibit the latest sexual onset; boys' sexual behavior is particularly sensitive to age at migration. Parental union stability is protective for first- and second-generation youth, especially boys; however, instability in co-residence with parents accelerates sexual debut for foreign-born girls, and dilutes protections from parental marital stability. Use of a non-English language at home delays sexual onset for immigrant girls, but not boys.

  14. Spent fuel storage. Facts booklet

    SciTech Connect

    1980-04-01

    In October 1977, the Department of Energy (DOE) announced a spent nuclear fuel policy where the Government would, under certain conditions, take title to and store spent nuclear fuel from commercial power reactors. The policy is intended to provide spent fuel storage until final disposition is available. DOE has programs for providing safe, long-term disposal of nuclear waste. The spent fuel storage program is one element of waste management and compliments the disposal program. The costs for spent fuel services are to be fully recovered by the Government from the utilities. This will allow the utilities to confidently consider the costs for disposition of spent fuel in their rate structure. The United States would also store limited amounts of foreign spent fuel to meet nonproliferation objectives. This booklet summarizes information on many aspects of spent fuel storage.

  15. 26 CFR 1.410(a)-4 - Maximum age conditions and time of participation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Maximum age conditions and time of participation... Maximum age conditions and time of participation. (a) Maximum age conditions—(1) General rule. A plan is... excludes from participation (on the basis of age) an employee who has attained an age specified by the...

  16. Health-Related Physical Fitness, BMI, physical activity and time spent at a computer screen in 6 and 7-year-old children from rural areas in Poland.

    PubMed

    Cieśla, Elżbieta; Mleczko, Edward; Bergier, Józef; Markowska, Małgorzata; Nowak-Starz, Grażyna

    2014-01-01

    The objective of the study was determination of the effect of various forms of physical activity, BMI, and time devoted to computer games on the level of Health-Related Physical Fitness (H-RF) in 6-7-year-old children from Polish rural areas. The study covered 25,816 children aged 6-7: 12,693 girls and 13,123 boys. The evaluations included body height and weight, and 4 H-RF fitness components (trunk strength, explosive leg power, arm strength and flexibility). The BMI was calculated for each child. The Questionnaire directed to parents was designed to collect information concerning the time devoted by children to computer games, spontaneous and additional physical activity. The strength of the relationships between dependent and independent variables was determined using the Spearman's rank correlation (RSp), and the relationship by using the regression analysis. The BMI negatively affected the level of all the H-RF components analysed (p=0.000). The negative effect of computer games revealed itself only with respect to flexibility (p=0.000), explosive leg power (p=0.000) and trunk muscle strength (p=0.000). A positive effect of spontaneous activity was observed for flexibility (p=0.047), explosive leg power (p=0.000), and arm strength (p=0.000). Additional activity showed a positive relationship with trunk muscles strength (p=0.000), and explosive leg power (p=0.000). The results of studies suggest that it is necessary to pay attention to the prevention of diseases related with the risk of obesity and overweight among Polish rural children as early as at pre-school age. There is also a need during education for shaping in these children the awareness of concern about own body, and the need for active participation in various forms of physical activity.

  17. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  18. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  19. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  20. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  1. Inspection Time and Cognitive Abilities in Twins Aged 7 to 17 Years: Age-Related Changes, Heritability and Genetic Covariance

    ERIC Educational Resources Information Center

    Edmonds, Caroline J.; Isaacs, Elizabeth B.; Visscher, Peter M.; Rogers, Mary; Lanigan, Julie; Singhal, Atul; Lucas, Alan; Gringras, Paul; Denton, Jane; Deary, Ian J.

    2008-01-01

    We studied the age-related differences in inspection time and multiple cognitive domains in a group of monozygotic (MZ) and dizygotic (DZ) twins aged 7 to 17 years. Data from 111 twin pairs and 19 singleton siblings were included. We found clear age-related trends towards more efficient visual information processing in older participants. There…

  2. Effects of post-mortem aging time and type of aging on palatability of low marbled beef loins.

    PubMed

    Lepper-Blilie, A N; Berg, E P; Buchanan, D S; Berg, P T

    2016-02-01

    The study objective was to evaluate the effect of post-mortem aging period (14 to 49days), dry vs. wet (D vs W) type of aging on the palatability of bone-in (BI) beef short loins (n=96) and boneless (BL) strip loins (n=96) possessing United States Department of Agriculture marbling scores between Slight and Small. Warner-Bratzler shear force (WBSF) scores decreased linearly over time (P=0.0001). WBSF was not influenced by aging method or loin type. Aged flavor was higher for DBL than for DBI with WBL and WBI intermediate. Dry aging strip loins increase aged flavor yet did not improve beefy flavor compared to wet aging. Based on objective data and panelist's scores for tenderness, juiciness and aged flavor, a boneless, 28days wet aged strip steak, cooked to 71°C would provide the best combination of eating satisfaction and value.

  3. Mexican Immigrant Fathers' and Mothers' Engagement with School-Age Children

    ERIC Educational Resources Information Center

    Hossain, Ziarat; Shipman, Virginia

    2009-01-01

    This study examined mothers' and fathers' reports of their time spent in their school-age children's care and academic work and the relationships between socioeconomic status and social support variables with fathers' time spent in children's care and academic work within two-parent Mexican immigrant families. Mother and father dyads from 79…

  4. Mean Velocity of Local Populations: Axiality, Age and Time Dependence

    NASA Astrophysics Data System (ADS)

    Cubarsi, Rafael; Alcobé, Santiago

    2007-05-01

    The mean velocity of local stellar populations is analyzed by building a set of hierarchically selected samples from Hipparcos catalog, with the full space motions. The technique for scanning populations, MEMPHIS (Maximum Entropy of the Mixture Probability from HIerarchical Segregation), is a combination of two separate procedures: A sample selecting filter (Alcobé & Cubarsi 2005, A&A 442, 292) and a segregation method (Cubarsi & Alcobé 2004, A&A 427, 131). By continuously increasing the sampling parameter, in our case the absolute value of the stellar velocity, we build a set of nested subsamples containing an increasing number of populations. A bimodal pattern is then applied in order to identify differentiated kinematic populations. The resulting populations can be identified as early-type stars, young disk stars, old disk stars, and thick disk stars. Discontinuities of the velocity dispersion are found for early-type and thick disk stars, while young and old disk stars show a continuous trend that is asymptotically represented by the thin disk galactic component. Similarly, the mean velocity of early-type stars shows a particular behavior, while the remaining populations share a similar average motion. The later populations are studied on the basis of a time-dependent and non-axial Chandrasekhar model, allowing to estimate the degree of deviation from axial symmetry and steady-state hypotheses, as well as the average age of each population. According to this model, the no net radial movement point can be evaluated, having heliocentric velocities U=-18 ± 1 km/s in the radial direction, which is very close to the radial mean velocity of early-type stars, and V=-76 ± 2 km/s in rotation. The remaining populations share a common differential galactic movement, suggesting a common dynamical origin for the rupture of the axial symmetry.

  5. 26 CFR 1.410(a)-4 - Maximum age conditions and time of participation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 5 2014-04-01 2014-04-01 false Maximum age conditions and time of participation.... § 1.410(a)-4 Maximum age conditions and time of participation. (a) Maximum age conditions—(1) General...) if the plan excludes from participation (on the basis of age) an employee who has attained an...

  6. 26 CFR 1.410(a)-4 - Maximum age conditions and time of participation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 5 2012-04-01 2011-04-01 true Maximum age conditions and time of participation.... § 1.410(a)-4 Maximum age conditions and time of participation. (a) Maximum age conditions—(1) General...) if the plan excludes from participation (on the basis of age) an employee who has attained an...

  7. 26 CFR 1.410(a)-4 - Maximum age conditions and time of participation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 5 2011-04-01 2011-04-01 false Maximum age conditions and time of participation.... § 1.410(a)-4 Maximum age conditions and time of participation. (a) Maximum age conditions—(1) General...) if the plan excludes from participation (on the basis of age) an employee who has attained an...

  8. Mass imprisonment and the life course revisited: Cumulative years spent imprisoned and marked for working-age black and white men.

    PubMed

    Patterson, Evelyn J; Wildeman, Christopher

    2015-09-01

    Over the last 40 years, imprisonment has become a common stage in the life-course for low-skilled and minority men, with implications not only for inequality among adult men but also for inequality more broadly. Unfortunately, all research documenting how increases in imprisonment have transformed the life-course of poor, minority men has neglected to estimate how much time black and white men on average spend imprisoned or marked as an ex-prisoner. In this article, we fill this gap by using multistate life tables to estimate what share of their working lives (18-64) black and white men will spend imprisoned and marked as ex-prisoners. Our estimates imply that white men spend on average 0.33 years of their working lives imprisoned and 2.31 years marked, while black men spend on average 1.79 years of their working lives imprisoned and 11.14 years marked. This implies that black men spend on average one-third of their working lives either imprisoned or having been freed but marked by the penal system. For the 32.2% of black men who ever experience imprisonment (Bonczar, 2003), moreover, these estimates imply that they spend on average 5.56 years imprisoned, corresponding to 13.4% of their working lives. Taken together, these findings imply a dramatic reorientation of the life course for black men, as one-third of the black male population will spend one-seventh of their working life in prison.

  9. Does Time Matter? Comparing Trajectory Concordance and Covariate Association Using Time-Based and Age-Based Assessments

    ERIC Educational Resources Information Center

    Piquero, Alex R.; Monahan, Kathryn C.; Glasheen, Cristie; Schubert, Carol A.; Mulvey, Edward P.

    2013-01-01

    Much criminological research has used longitudinal data to assess change in offending over time. An important feature of some data sources is that they contain cross-sections of different aged individuals followed over successive time periods, thereby potentially conflating age and time. This article compares the substantive conclusions about the…

  10. The Maillard hypothesis on aging: time to focus on DNA.

    PubMed

    Baynes, John W

    2002-04-01

    Aging is the outcome of the contest between chemistry and biology in living systems. Chronic, cumulative chemical modifications compromise the structure and function of biomolecules throughout the body. Proteins with long life spans serve as cumulators of exposure to chemical damage, which is detectable in the form of advanced glycation and lipoxidation end products (AGEs, ALEs); amino acids modified by reactive oxygen, chlorine, and nitrogen species; and deamidated and racemized amino acids. Not all of these modifications are oxidative in nature, although oxidative reactions are an important source of age-related damage. Measurements of AGEs and ALEs in proteins are useful for assessing the rate and extent of Maillard reaction damage, but it is the damage to the genome that undoubtedly has the greatest effect on the viability of the organism. The extent of genomic damage represents a balance between the rate of modification and the rate and fidelity of repair. Damage to DNA accumulates not in the form of modified nucleic acids, but as chemically "silent" errors in repair-insertions, deletions, substitutions, transpositions, and inversions in DNA sequences-that affect the expression and structure of proteins. These mutations are random, vary from cell to cell, and are passed forward from one cell generation to another. Although they are not detectable in DNA by conventional analytical techniques, purines and pyrimidines modified by Maillard reaction intermediates may be detectable in urine, and studies on these compounds should provide insight into the role of Maillard reactions of DNA in aging and disease.

  11. Reclaim spent catalysts properly

    SciTech Connect

    Lassner, J.A.; Lasher, L.B.; Koppel, R.L.; Hamilton, J.N.

    1994-08-01

    Treatment of spent catalysts and metallic by products has become increasingly more complex over the last couple of years, due to tightening environmental concerns. Three options are available: (1) Reclaiming the metals and either reusing them to make new catalyst or recycling them for other uses. This is now the preferred option. A reclaiming firm is generally employed to handle the task. (2) Regeneration and reuse. While this generally is the preferred option, few commercial catalysts can be regenerated effectively and economically. (3) Landfilling. This has been the traditional route. However, stricter environmental regulations have made landfilling unattractive. To maximize the reclamation both economically and environmentally, five factors should be addressed: (1) proper planning and physical handling; (2) transportation of materials; (3) environmental concerns; (4) end uses of the catalyst; and (5) choosing the proper reclamation partner. These factors are discussed.

  12. Aging in precarious times: Exploring the role of gender in shaping views on aging.

    PubMed

    Craciun, Catrinel; Flick, Uwe

    2016-01-01

    The present study explores views on aging and how these differ according to gender and precariousness status. Semistructured interviews were conducted with 10 men and 10 women with secure and insecure pensions. Themes like fear of illness and health decline were more present in men, while fear of losing their attractiveness in old age more present among women. For all participants, loss of autonomy and social roles represented a negative view of old age, while activity in the form of work, volunteering, or leisure represented positive views. Differences in views on aging were related to pension security and less to gender. Women with insecure pension plans displayed the most negative views of aging. Implications for practice and policy to prevent health and gender inequalities are discussed.

  13. Sexuality and Aging: A Timely Addition to the Gerontology Curriculum.

    ERIC Educational Resources Information Center

    Fitzpatrick, Tanya R.

    2000-01-01

    Describes the development and content of a course on sexuality in aging for a gerontology master's program. Topics include physical health, AIDS, gay/lesbian issues, widows/widowers, marriage, ethnic issues, menopause, and impotence. Provides a 33-item bibliography. (SK)

  14. Effect of Blade Tenderization, Aging Time and Aging Temperature on Tenderness of Beef Longissimus Lumborum and Gluteus Medius

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to evaluate the effects of blade tenderization, aging time, and aging temperature on the tenderness of longissimus lumborum (LL) and gluteus medius (GM) steaks. Beef strip loins (n = 300) and top sirloin butts (n = 300) were selected from a large beef processor and transported...

  15. 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

  16. Time since discharge of 9mm cartridges by headspace analysis, part 2: Ageing study and estimation of the time since discharge using multivariate regression.

    PubMed

    Gallidabino, M; Romolo, F S; Weyermann, C

    2017-03-01

    Estimating the time since discharge of spent cartridges can be a valuable tool in the forensic investigation of firearm-related crimes. To reach this aim, it was previously proposed that the decrease of volatile organic compounds released during discharge is monitored over time using non-destructive headspace extraction techniques. While promising results were obtained for large-calibre cartridges (e.g., shotgun shells), handgun calibres yielded unsatisfying results. In addition to the natural complexity of the specimen itself, these can also be attributed to some selective choices in the methods development. Thus, the present series of papers aimed to systematically evaluate the potential of headspace analysis to estimate the time since discharge of cartridges through the use of more comprehensive analytical and interpretative techniques. Following the comprehensive optimisation and validation of an exhaustive headspace sorptive extraction (HSSE) method in the first part of this work, the present paper addresses the application of chemometric tools in order to systematically evaluate the potential of applying headspace analysis to estimate the time since discharge of 9mm Geco cartridges. Several multivariate regression and pre-treatment methods were tested and compared to univariate models based on non-linear regression. Random forests (RF) and partial least squares (PLS) proceeded by pairwise log-ratios normalisation (PLR) showed the best results, and allowed to estimate time since discharge up to 48h of ageing and to differentiate recently fired from older cartridges (e.g., less than 5h compared to more than 1-2 days). The proposed multivariate approaches showed significant improvement compared to univariate models. The effects of storage conditions were also tested and results demonstrated that temperature, humidity and cartridge position should be taken into account when estimating the time since discharge.

  17. Modeling the Phenotypic Architecture of Autism Symptoms from Time of Diagnosis to Age 6

    ERIC Educational Resources Information Center

    Georgiades, Stelios; Boyle, Michael; Szatmari, Peter; Hanna, Steven; Duku, Eric; Zwaigenbaum, Lonnie; Bryson, Susan; Fombonne, Eric; Volden, Joanne; Mirenda, Pat; Smith, Isabel; Roberts, Wendy; Vaillancourt, Tracy; Waddell, Charlotte; Bennett, Teresa; Elsabbagh, Mayada; Thompson, Ann

    2014-01-01

    The latent class structure of autism symptoms from the time of diagnosis to age 6 years was examined in a sample of 280 children with autism spectrum disorder. Factor mixture modeling was performed on 26 algorithm items from the Autism Diagnostic Interview-Revised at diagnosis (Time 1) and again at age 6 (Time 2). At Time 1, a…

  18. The Effects of Aging on Time Reproduction in Delayed Free-Recall

    ERIC Educational Resources Information Center

    Rakitin, B.C.; Stern, Y.; Malapani, C.

    2005-01-01

    The experiments presented here demonstrate that normal aging amplifies differences in time production occurring in delayed free-recall testing. Experiment 1 compared the time production ability of two healthy aged groups as well as college-aged participants. During the test session, which followed a 24-h delay and omitted all feedback and examples…

  19. Time as a Tool for Policy Analysis in Aging.

    ERIC Educational Resources Information Center

    Pastorello, Thomas

    National policy makers have put forth different life cycle planning proposals for the more satisfying integration of education, work and leisure over the life course. This speech describes a decision making scheme, the Time Paradigm, for researched-based choice among various proposals. The scheme is defined in terms of a typology of time-related…

  20. The impact of professional isolation on teleworker job performance and turnover intentions: does time spent teleworking, interacting face-to-face, or having access to communication-enhancing technology matter?

    PubMed

    Golden, Timothy D; Veiga, John F; Dino, Richard N

    2008-11-01

    Although the teleworking literature continues to raise concerns regarding the adverse consequences of professional isolation, researchers have not examined its impact on work outcomes. Consequently, the authors first examine professional isolation's direct impact on job performance and turnover intentions among teleworkers and then investigate the contingent role of 3 salient work-mode-related factors. Survey data from a matched sample of 261 professional-level teleworkers and their managers revealed that professional isolation negatively impacts job performance and, contrary to expectations, reduces turnover intentions. Moreover, professional isolation's impact on these work outcomes is increased by the amount of time spent teleworking, whereas more face-to-face interactions and access to communication-enhancing technology tend to decrease its impact. On the basis of these findings, an agenda for future research on professional isolation is offered that takes into account telework's growing popularity as a work modality.

  1. The timing of the age at which natural menopause occurs.

    PubMed

    Gold, Ellen B

    2011-09-01

    The timing of natural menopause is a clinically important indicator of longevity and risk of morbidity and mortality. Demographic, menstrual, reproductive, familial, genetic, and lifestyle factors seem to be important in this timing. Smoking, lower parity and poor socioeconomic status are associated with earlier menopause. However, a number of relationships have been inconsistent; others remain largely unexplored. Much remains to be learned about factors that affect follicular atresia and the onset and duration of perimenopause and the timing of the natural menopause. Knowledge about these relationships offers women and their health care providers enhanced understanding and choices to deal with menopause.

  2. Age effects on discrimination of timing in auditory sequences

    NASA Astrophysics Data System (ADS)

    Fitzgibbons, Peter J.; Gordon-Salant, Sandra

    2004-08-01

    The experiments examined age-related changes in temporal sensitivity to increments in the interonset intervals (IOI) of components in tonal sequences. Discrimination was examined using reference sequences consisting of five 50-ms tones separated by silent intervals; tone frequencies were either fixed at 4 kHz or varied within a 2-4-kHz range to produce spectrally complex patterns. The tonal IOIs within the reference sequences were either equal (200 or 600 ms) or varied individually with an average value of 200 or 600 ms to produce temporally complex patterns. The difference limen (DL) for increments of IOI was measured. Comparison sequences featured either equal increments in all tonal IOIs or increments in a single target IOI, with the sequential location of the target changing randomly across trials. Four groups of younger and older adults with and without sensorineural hearing loss participated. Results indicated that DLs for uniform changes of sequence rate were smaller than DLs for single target intervals, with the largest DLs observed for single targets embedded within temporally complex sequences. Older listeners performed more poorly than younger listeners in all conditions, but the largest age-related differences were observed for temporally complex stimulus conditions. No systematic effects of hearing loss were observed.

  3. Measuring Space-Time Geometry over the Ages

    SciTech Connect

    Stebbins, Albert; /Fermilab

    2012-05-01

    Theorists are often told to express things in the 'observational plane'. One can do this for space-time geometry, considering 'visual' observations of matter in our universe by a single observer over time, with no assumptions about isometries, initial conditions, nor any particular relation between matter and geometry, such as Einstein's equations. Using observables as coordinates naturally leads to a parametrization of space-time geometry in terms of other observables, which in turn prescribes an observational program to measure the geometry. Under the assumption of vorticity-free matter flow we describe this observational program, which includes measurements of gravitational lensing, proper motion, and redshift drift. Only 15% of the curvature information can be extracted without long time baseline observations, and this increases to 35% with observations that will take decades. The rest would likely require centuries of observations. The formalism developed is exact, non-perturbative, and more general than the usual cosmological analysis.

  4. Silver: an age-old treatment modality in modern times.

    PubMed

    Spear, Marcia

    2010-01-01

    The use of silver as an antimicrobial for infection spans hundreds of years. The ancient Greeks and Romans used silver to disinfect their water and food supplies. Silver was also used in ancient times to treat burns and wounds as a wound dressing. Silver solutions were approved by the U.S. Food and Drug Administration in the 1920s. Since that time, silver has established itself as an effective and well-known treatment modality for and in the prevention of high-risk infection in clinical wound care (http://int.hansaplast.com/med-info/wound-care-beautiful-healing/silver-tech.html).

  5. Inventory management in the just-in-time age.

    PubMed

    Jordan, H H

    1990-08-01

    JIT will change our conventional thinking concerning the management of inventories and streamline our methods for inventory control. Proper selection and implementation of these methods will yield substantial benefits by improving customer service, shortening delivery lead times, and significantly reducing inventory investment. It does not, however, eliminate the need for sound inventory planning.

  6. Lake Erie Yellow perch age estimation based on three structures: Precision, processing times, and management implications

    USGS Publications Warehouse

    Vandergoot, C.S.; Bur, M.T.; Powell, K.A.

    2008-01-01

    Yellow perch Perca flavescens support economically important recreational and commercial fisheries in Lake Erie and are intensively managed. Age estimation represents an integral component in the management of Lake Erie yellow perch stocks, as age-structured population models are used to set safe harvest levels on an annual basis. We compared the precision associated with yellow perch (N = 251) age estimates from scales, sagittal otoliths, and anal spine sections and evaluated the time required to process and estimate age from each structure. Three readers of varying experience estimated ages. The precision (mean coefficient of variation) of estimates among readers was 1% for sagittal otoliths, 5-6% for anal spines, and 11-13% for scales. Agreement rates among readers were 94-95% for otoliths, 71-76% for anal spines, and 45-50% for scales. Systematic age estimation differences were evident among scale and anal spine readers; less-experienced readers tended to underestimate ages of yellow perch older than age 4 relative to estimates made by an experienced reader. Mean scale age tended to underestimate ages of age-6 and older fish relative to otolith ages estimated by an experienced reader. Total annual mortality estimates based on scale ages were 20% higher than those based on otolith ages; mortality estimates based on anal spine ages were 4% higher than those based on otolith ages. Otoliths required more removal and preparation time than scales and anal spines, but age estimation time was substantially lower for otoliths than for the other two structures. We suggest the use of otoliths or anal spines for age estimation in yellow perch (regardless of length) from Lake Erie and other systems where precise age estimates are necessary, because age estimation errors resulting from the use of scales could generate incorrect management decisions. ?? Copyright by the American Fisheries Society 2008.

  7. Case histories of West Valley spent fuel shipments: Final report

    SciTech Connect

    Not Available

    1987-01-01

    In 1983, NRC/FC initiated a study on institutional issues related to spent fuel shipments originating at the former spent fuel processing facility in West Valley, New York. FC staff viewed the shipment campaigns as a one-time opportunity to document the institutional issues that may arise with a substantial increase in spent fuel shipping activity. NRC subsequently contracted with the Aerospace Corporation for the West Valley Study. This report contains a detailed description of the events which took place prior to and during the spent fuel shipments. The report also contains a discussion of the shipment issues that arose, and presents general findings. Most of the institutional issues discussed in the report do not fall under NRC's transportation authority. The case histories provide a reference to agencies and other institutions that may be involved in future spent fuel shipping campaigns. 130 refs., 7 figs., 19 tabs.

  8. Assessment of spent fuel cooling

    SciTech Connect

    Ibarra, J.G.; Jones, W.R.; Lanik, G.F.

    1997-02-01

    The paper presents the methodology, the findings, and the conclusions of a study that was done by the Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) on loss of spent fuel pool cooling. The study involved an examination of spent fuel pool designs, operating experience, operating practices, and procedures. AEOD`s work was augmented in the area of statistics and probabilistic risk assessment by experts from the Idaho Nuclear Engineering Laboratory. Operating experience was integrated into a probabilistic risk assessment to gain insight on the risks from spent fuel pools.

  9. Gender Transitions in Later Life: The Significance of Time in Queer Aging

    PubMed Central

    Fabbre, Vanessa D.

    2014-01-01

    Concepts of time are ubiquitous in studies of aging. This article integrates an existential perspective on time with a notion of queer time based on the experiences of older transgender persons who contemplate or pursue a gender transition in later life. Interviews were conducted with male-to-female identified persons aged 50 years or older (N=22), along with participant observation at three national transgender conferences (N=170 hours). Interpretive analyses suggest that an awareness of “time left to live” and a feeling of “time served” play a significant role in later life development and help expand gerontological perspectives on time and queer aging. PMID:24798691

  10. Learning Style versus Time Spent Studying and Career Choice: Which Is Associated with Success in a Combined Undergraduate Anatomy and Physiology Course?

    ERIC Educational Resources Information Center

    Farkas, Gary J.; Mazurek, Ewa; Marone, Jane R.

    2016-01-01

    The VARK learning style is a pedagogical focus in health care education. This study examines relationships of course performance vs. VARK learning preference, study time, and career plan among students enrolled in an undergraduate anatomy and physiology course at a large urban university. Students (n?=?492) from the fall semester course completed…

  11. Does Patient Time Spent Viewing Computer-Tailored Colorectal Cancer Screening Materials Predict Patient-Reported Discussion of Screening with Providers?

    ERIC Educational Resources Information Center

    Sanders, Mechelle; Fiscella, Kevin; Veazie, Peter; Dolan, James G.; Jerant, Anthony

    2016-01-01

    The main aim is to examine whether patients' viewing time on information about colorectal cancer (CRC) screening before a primary care physician (PCP) visit is associated with discussion of screening options during the visit. We analyzed data from a multi-center randomized controlled trial of a tailored interactive multimedia computer program…

  12. The Effects of Positive Verbal Reinforcement on the Time Spent outside the Classroom for Students with Emotional and Behavioral Disorders in a Residential Setting

    ERIC Educational Resources Information Center

    Kennedy, Christina; Jolivette, Kristine

    2008-01-01

    To more effectively instruct the entire class, teachers of students with emotional behavioral disorders (EBD) often choose to send students who display inappropriate behavior out of the room. A multiple baseline across settings was used to evaluate the effects of increasing teacher positive verbal reinforcement on the amount of time 2 students…

  13. Effect of blade tenderization, aging time, and aging temperature on tenderness of beef longissimus lumborum and gluteus medius.

    PubMed

    King, D A; Wheeler, T L; Shackelford, S D; Pfeiffer, K D; Nickelson, R; Koohmaraie, M

    2009-09-01

    Purveyors are concerned about the potential food safety risk of nonintact meat products and are seeking strategies to ensure adequate meat tenderness without blade tenderization. This study was conducted to determine the effects of blade tenderization and time and temperature of aging on beef longissimus lumborum (LL) and gluteus medius (GM) tenderness. Beef strip loins (n = 300) and top sirloin butts (n = 300) were assigned to storage at -0.5 or 3.3 degrees C for 12, 26, or 40 d. Cuts were blade tenderized (BT) or not blade tenderized (NBT) before steak cutting. One 2.54-cm steak from each subprimal was used for slice shear force determination and Western blotting of desmin. Desmin degradation was less (P < 0.05) in LL stored at -0.5 degrees C than LL stored at 3.3 degrees C (57 and 65%, respectively). Aging from 12 to 26 d increased (P < 0.05) proteolysis (50 to 65%) in LL. Regardless of aging time, BT reduced (P < 0.05) LL slice shear force values. Aging time did not affect (P > 0.05) slice shear force values of BT LL steaks (10.4, 9.9, and 9.4 kg for 12, 26, and 40 d aging, respectively), but reduced (P < 0.05) NBT steak slice shear force values (15.1, 13.8, and 12.3 kg for 12, 26, and 40 d aging, respectively). Greater temperature did not affect (P > 0.05) slice shear force values of BT LL steaks (10.2 and 9.6 kg for steaks aged at -0.5 and 3.3 degrees C, respectively), but improved (P < 0.05) slice shear force of NBT LL steaks (15.1 and 12.4, respectively). Aging at 3.3 degrees C increased (P < 0.05) proteolysis in GM steaks (43 and 54% for -0.5 and 3.3 degrees C, respectively). Longer aging times increased (P < 0.05) proteolysis (40, 46, and 60% for 12, 26, and 40 d aging, respectively) in GM steaks. Blade-tenderized GM steaks had dramatically less (P < 0.05) slice shear force values than NBT steaks (13.7 and 19.9 kg, respectively). Raising aging temperature from -0.5 to 3.3 degrees C reduced (17.6 vs. 16.0 kg; P < 0.05) and increasing aging time from 12 d

  14. Active Interrogation for Spent Fuel

    SciTech Connect

    Swinhoe, Martyn Thomas; Dougan, Arden

    2015-11-05

    The DDA instrument for nuclear safeguards is a fast, non-destructive assay, active neutron interrogation technique using an external 14 MeV DT neutron generator for characterization and verification of spent nuclear fuel assemblies.

  15. Age and Time Population Differences: Young Adults, Gen Xers, and Millennials

    ERIC Educational Resources Information Center

    Menard, Lauren A.

    2013-01-01

    Age and Time disparities in young adult research populations are common because young adults are defined by varying age spans; members of Generation X and Millennial generations may both be considered young adults; study years vary, affecting populations; and qualitative methods with limited age/year samples are frequently utilized. The current…

  16. The Relationship between Time Spent Living with Kin and Adolescent Functioning in Youth with a History of Out-of-Home Placement

    ERIC Educational Resources Information Center

    Taussig, Heather N.; Clyman, Robert B.

    2011-01-01

    Objective: Many children in the US who are court-ordered to live in out-of-home care are placed with kinship caregivers. Few studies have examined the impact of living with kin on child well-being. This study examined the relationship between length of time living with kin and indices of adolescent well-being in a cohort of children who were…

  17. Transportation of spent MTR fuels

    SciTech Connect

    Raisonnier, D.

    1997-08-01

    This paper gives an overview of the various aspects of MTR spent fuel transportation and provides in particular information about the on-going shipment of 4 spent fuel casks to the United States. Transnucleaire is a transport and Engineering Company created in 1963 at the request of the French Atomic Energy Commission. The company followed the growth of the world nuclear industry and has now six subsidiaries and affiliated companies established in countries with major nuclear programs.

  18. Water age, exposure time, and local flushing time in semi-enclosed, tidal basins with negligible freshwater inflow

    NASA Astrophysics Data System (ADS)

    Viero, Daniele Pietro; Defina, Andrea

    2016-04-01

    Within the framework of tidally flushed, semi-enclosed basins with negligible freshwater inflow, and under steady periodic flow conditions, three frequently used local transport time scales to quantify the efficiency of water renewal, namely water age, exposure time, and local flushing time are studied and compared to each other. In these environments, water renewal is strongly controlled by diffusion, and it is significantly affected by the return flow (i.e., the fraction of effluent water that returns into the basin on each flood tide). The definition of water age is here modified to account for the return flow, in analogy with exposure time and local flushing time. We consider approximate time scales, whose accuracy is analyzed, in order to overcome problems related to the size of the computational domain and to reduce the computational effort. A new approximate procedure is introduced to estimate water age, which is based on the water aging rate. Also, the concept of local flushing time as a relevant time scale is introduced. Under steady periodic conditions, we demonstrate that the local flushing time quantitatively corresponds to water age, and well approximates exposure time when the flow is dominated by diffusion. Since the effort required to compute water age and exposure time is greater than that required to compute the local flushing time, the present results can also have a practical interest in the assessment of water renewal efficiency of semi-enclosed water basins. The results of a modeling study, in which the lagoon of Venice is used as a benchmark, confirm the substantial quantitative equivalence between these three transport time scales in highly diffusive environments.

  19. The spent fuel safety experiment

    SciTech Connect

    Harms, G.A.; Davis, F.J.; Ford, J.T.

    1995-08-01

    The Department of Energy is conducting an ongoing investigation of the consequences of taking fuel burnup into account in the design of spent fuel transportation packages. A series of experiments, collectively called the Spent Fuel Safety Experiment (SFSX), has been devised to provide integral benchmarks for testing computer-generated predictions of spent fuel behavior. A set of experiments is planned in which sections of unirradiated fuel rods are interchanged with similar sections of spent PWR fuel rods in a critical assembly. By determining the critical size of the arrays, one can obtain benchmark data for comparison with criticality safety calculations. The SFSX provides a direct measurement of the reactivity effects of spent PWR fuel using a well-characterized, spent fuel sample. The SFSX also provides an experimental measurement of the end-effect, i.e., the reactivity effect of the variation of the burnup profile at the ends of PWR fuel rods. The design of the SFSX is optimized to yield accurate benchmark measurements of the effects of interest, well above experimental uncertainties.

  20. Type of treatment, prognosis, and estimation of time spent to manage dental trauma in late presentation cases at a dental teaching hospital: a longitudinal and retrospective study.

    PubMed

    Al-Jundi, Suhad H

    2004-02-01

    Traumatic dental injuries are emergencies that must be treated promptly and properly in order to reduce the suffering, costs, and time for patients, parents, and health care providers. The aim of this study was to investigate the treatment, long-term prognosis, and number of visits needed to manage cases resulting from complications of late presentation of traumatic dental injuries. The sample consisted of 195 children, all presented with complications of dental trauma at the Pediatric Dentistry Clinics in the Dental Teaching Hospital of Jordan University of Science and Technology in Irbid city, Jordan. Retrospective data relied on trauma forms as well the clinical notes and radiographs in the patients' records. Prospective data was collected by examining patients at recall appointments. The treatment of traumatized teeth in this sample ranged from no active treatment to extraction and prosthetic replacement. It was estimated that the number of visits needed to carry out the planned treatment for these patients ranged between 3 and 17.2 visits according to the type of treatment. Apexification procedure was the most time consuming. Thirty-two per cent of teeth with apexification ended up with root fracture mainly subsequent to another minor trauma episode (in 85%), the rest were reported to be spontaneous fractures. Almost half of the teeth with luxation injuries became necrotic after 3 years. Teeth with avulsion actually kept on deteriorating even at the 36-month follow-up appointment. The long-term prognosis of teeth with middle root fracture was favorable in (80%) of the teeth in the sample, despite the fact that they were splinted late. Luxation injuries led to more necrotic teeth (50%) than uncomplicated crown fractures. Multiple dental trauma episodes (MDTE) were reported in about 30% of the patients in the sample and were responsible for some of the complications noticed in this report. As all cases followed up in this report are late presentation of dental

  1. Federal Expenditures on Elementary-Age Children in 2008 (Ages 6 through 11)

    ERIC Educational Resources Information Center

    Vericker, Tracy C.; Macomber, Jennifer; Isaacs, Julia; Kent, Adam; Bringewatt, Elizabeth H.

    2010-01-01

    This report provides a first-time analysis of the nation's current investments in elementary-age children, defined as children ages 6 through 11. The authors consider over 100 federal programs through which the federal government allocates money to children, and subsequently estimate the amount spent on six- to eleven-year-old children. This…

  2. Associations between Menarcheal Timing and Behavioral Developmental Trajectories for Girls from Age 6 to Age 15

    ERIC Educational Resources Information Center

    DeRose, Laura M.; Shiyko, Mariya P.; Foster, Holly; Brooks-Gunn, Jeanne

    2011-01-01

    Substantial evidence from cross-sectional and short time-span longitudinal studies exists about negative associations between early pubertal maturation on a number of psychological outcomes. The objective of the present study was to assess the association between early maturation and developmental trajectories of social skills and internalizing…

  3. Loss of spent fuel pool cooling PRA: Model and results

    SciTech Connect

    Siu, N.; Khericha, S.; Conroy, S.; Beck, S.; Blackman, H.

    1996-09-01

    This letter report documents models for quantifying the likelihood of loss of spent fuel pool cooling; models for identifying post-boiling scenarios that lead to core damage; qualitative and quantitative results generated for a selected plant that account for plant design and operational practices; a comparison of these results and those generated from earlier studies; and a review of available data on spent fuel pool accidents. The results of this study show that for a representative two-unit boiling water reactor, the annual probability of spent fuel pool boiling is 5 {times} 10{sup {minus}5} and the annual probability of flooding associated with loss of spent fuel pool cooling scenarios is 1 {times} 10{sup {minus}3}. Qualitative arguments are provided to show that the likelihood of core damage due to spent fuel pool boiling accidents is low for most US commercial nuclear power plants. It is also shown that, depending on the design characteristics of a given plant, the likelihood of either: (a) core damage due to spent fuel pool-associated flooding, or (b) spent fuel damage due to pool dryout, may not be negligible.

  4. DOE-owned spent nuclear fuel program plan

    SciTech Connect

    1995-11-01

    The Department of Energy (DOE) has produced spent nuclear fuel (SNF) for many years as part of its various missions and programs. The historical process for managing this SNF was to reprocess it whereby valuable material such as uranium or plutonium was chemically separated from the wastes. These fuels were not intended for long-term storage. As the need for uranium and plutonium decreased, it became necessary to store the SNF for extended lengths of time. This necessity resulted from a 1992 DOE decision to discontinue reprocessing SNF to recover strategic materials (although limited processing of SNF to meet repository acceptance criteria remains under consideration, no plutonium or uranium extraction for other uses is planned). Both the facilities used for storage, and the fuel itself, began experiencing aging from this extended storage. New efforts are now necessary to assure suitable fuel and facility management until long-term decisions for spent fuel disposition are made and implemented. The Program Plan consists of 14 sections as follows: Sections 2--6 describe objectives, management, the work plan, the work breakdown structure, and the responsibility assignment matrix. Sections 7--9 describe the program summary schedules, site logic diagram, SNF Program resource and support requirements. Sections 10--14 present various supplemental management requirements and quality assurance guidelines.

  5. Effect of Blade Tenderization, Aging Time, and Aging Temperature on Tenderness of Beef Longissimus Lumborum and Gluteus Medius

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purveyors are concerned about the food safety risk of non-intact meat products and are seeking strategies to ensure adequate meat tenderness without blade tenderization. This study was conducted to determine the effects of blade tenderization and time and temperature of aging on beef longissimus lu...

  6. Influence of evisceration time and carcass ageing conditions on wild venison quality. Preliminary study.

    PubMed

    Soriano, A; Montoro, V; Vicente, J; Sánchez-Migallón, B F; Benítez, S; Utrilla, M C; García Ruiz, A

    2016-04-01

    The influence of common carcass preparation practices of wild red deer on the physicochemical, microbiological and sensory quality of venison was assessed by varying evisceration time and ageing method. Deer were head shot; half were eviscerated 30 min and the other half 4 h post mortem. In both groups (n=18), 6 carcasses were skinned immediately after evisceration and aged for 24 h; 6 were aged unskinned for 24 h and 6 were aged unskinned for 72 h at 10°C. Ageing method had a significant effect on the sensory quality of venison loin; unskinned ageing was associated with an increase of odour and taste intensity, and higher scores for gamey and sweet/caramel flavours. Carcasses aged for 72 h displayed darker and tender meat, but increased aerobic bacterial counts. Evisceration time had less influence on loin quality, although off-flavours were more often detected in deer eviscerated 4h post mortem.

  7. Spent Nuclear Fuel project, project management plan

    SciTech Connect

    Fuquay, B.J.

    1995-10-25

    The Hanford Spent Nuclear Fuel Project has been established to safely store spent nuclear fuel at the Hanford Site. This Project Management Plan sets forth the management basis for the Spent Nuclear Fuel Project. The plan applies to all fabrication and construction projects, operation of the Spent Nuclear Fuel Project facilities, and necessary engineering and management functions within the scope of the project

  8. Pyrolysis of Spent Ion Exchange Resins - 12210

    SciTech Connect

    Braehler, Georg; Slametschka, Rainer

    2012-07-01

    Organic ion exchangers (IEX) play a major and increasing role in the reactor coolant and other water purification processes. During their operation time they receive significant amounts of radioactivity, making their disposal, together with their organic nature, as medium active waste challenging. Processes applied so far do not eliminate the organic matter, which is unwanted in disposal facilities, or, if high temperatures are applied, raise problems with volatile radionuclides. NUKEM Technologies offers their well introduces process for the destruction of spent solvent (TBP), the pebble bed pyrolysis, now for the treatment of spent IEX (and other problematic waste), with the following benefits: the pyrolysis product is free of organic matter, and the operation temperature with approx. 500 deg. C keeps Cs radionuclides completely in the solid residue. (authors)

  9. Simulation of Water Age and Residence Time in the New York Bight

    NASA Astrophysics Data System (ADS)

    Zhang, W. G.; Wilkin, J. L.; Schofield, O. M.

    2008-12-01

    Aiming at investigating the time scale of transporting biogeochemical tracers in the New York Bight (NYB), this work looks into the time scale associated with freshwater propagation in NYB. The Constituent-oriented Age and Residence-time Theory is applied in Regional Ocean Modeling System and then verified. Three-year mean age and two-year mean residence time simulations are carried out. Comparison between snapshots of modeled surface freshwater mean age and satellite measured channel ratio, an empirical proxy of age, shows agreement on the general patterns. Least square fit gives the first order estimation of the relationship between channel ratio and mean age. Time series show temporal and spatial variation in mean age, and seasonal averages demonstrate seasonality of surface mean age consistent with surface circulation. Correlation between surface mean age and wind shows major effects wind in different directions has on mean age. Time series of the mean residence time exhibits strong temporal fluctuation in the scale of days, and seasonal averages show seasonality in surface mean residence time, too. The surprising high value of mean residence time along the Long Island coast in spring and summer is caused by the reentry of previously exited water from the eastern boundary after wind changes direction. Correlation between mean residence time and wind shows major effects wind has on the time freshwater and tracers spend in the New York apex area. Results obtained here are very useful for coastal management and studies of local biogeochemical processes and larval dispersal given the ecological and economical importance of the New York Bay.

  10. Investigation of telomere lengths measurement by quantitative real-time PCR to predict age.

    PubMed

    Hewakapuge, Sudinna; van Oorschot, Roland A H; Lewandowski, Paul; Baindur-Hudson, Swati

    2008-09-01

    Currently DNA profiling methods only compare a suspect's DNA with DNA left at the crime scene. When there is no suspect, it would be useful for the police to be able to predict what the person of interest looks like by analysing the DNA left behind in a crime scene. Determination of the age of the suspect is an important factor in creating an identikit. Human somatic cells gradually lose telomeric repeats with age. This study investigated if one could use a correlation between telomere length and age, to predict the age of an individual from their DNA. Telomere length, in buccal cells, of 167 individuals aged between 1 and 96 years old was measured using real-time quantitative PCR. Telomere length decreased with age (r=-0.185, P<0.05) and the age of an individual could be roughly determined by the following formula: (age=relative telomere length -1.5/-0.005). The regression (R(2)) value between telomere length and age was approximately 0.04, which is too low to be use for forensics. The causes for the presence of large variation in telomere lengths in the population were further investigated. The age prediction accuracies were low even after dividing samples into non-related Caucasians, males and females (5%, 9% and 1%, respectively). Mean telomere lengths of eight age groups representing each decade of life showed non-linear decrease in telomere length with age. There were variations in telomere lengths even among similarly aged individuals aged 26 years old (n=10) and age 54 years old (n=9). Therefore, telomere length measurement by real-time quantitative PCR cannot be used to predict age of a person, due to the presence of large inter-individual variations in telomere lengths.

  11. DNA methylation-based measures of biological age: meta-analysis predicting time to death.

    PubMed

    Chen, Brian H; Marioni, Riccardo E; Colicino, Elena; Peters, Marjolein J; Ward-Caviness, Cavin K; Tsai, Pei-Chien; Roetker, Nicholas S; Just, Allan C; Demerath, Ellen W; Guan, Weihua; Bressler, Jan; Fornage, Myriam; Studenski, Stephanie; Vandiver, Amy R; Moore, Ann Zenobia; Tanaka, Toshiko; Kiel, Douglas P; Liang, Liming; Vokonas, Pantel; Schwartz, Joel; Lunetta, Kathryn L; Murabito, Joanne M; Bandinelli, Stefania; Hernandez, Dena G; Melzer, David; Nalls, Michael; Pilling, Luke C; Price, Timothy R; Singleton, Andrew B; Gieger, Christian; Holle, Rolf; Kretschmer, Anja; Kronenberg, Florian; Kunze, Sonja; Linseisen, Jakob; Meisinger, Christine; Rathmann, Wolfgang; Waldenberger, Melanie; Visscher, Peter M; Shah, Sonia; Wray, Naomi R; McRae, Allan F; Franco, Oscar H; Hofman, Albert; Uitterlinden, André G; Absher, Devin; Assimes, Themistocles; Levine, Morgan E; Lu, Ake T; Tsao, Philip S; Hou, Lifang; Manson, JoAnn E; Carty, Cara L; LaCroix, Andrea Z; Reiner, Alexander P; Spector, Tim D; Feinberg, Andrew P; Levy, Daniel; Baccarelli, Andrea; van Meurs, Joyce; Bell, Jordana T; Peters, Annette; Deary, Ian J; Pankow, James S; Ferrucci, Luigi; Horvath, Steve

    2016-09-28

    Estimates of biological age based on DNA methylation patterns, often referred to as "epigenetic age", "DNAm age", have been shown to be robust biomarkers of age in humans. We previously demonstrated that independent of chronological age, epigenetic age assessed in blood predicted all-cause mortality in four human cohorts. Here, we expanded our original observation to 13 different cohorts for a total sample size of 13,089 individuals, including three racial/ethnic groups. In addition, we examined whether incorporating information on blood cell composition into the epigenetic age metrics improves their predictive power for mortality. All considered measures of epigenetic age acceleration were predictive of mortality (p≤8.2x10(-9)), independent of chronological age, even after adjusting for additional risk factors (p<5.4x10(-4)), and within the racial/ethnic groups that we examined (non-Hispanic whites, Hispanics, African Americans). Epigenetic age estimates that incorporated information on blood cell composition led to the smallest p-values for time to death (p=7.5x10(-43)). Overall, this study a) strengthens the evidence that epigenetic age predicts all-cause mortality above and beyond chronological age and traditional risk factors, and b) demonstrates that epigenetic age estimates that incorporate information on blood cell counts lead to highly significant associations with all-cause mortality.

  12. Subliminal strengthening: improving older individuals' physical function over time with an implicit-age-stereotype intervention.

    PubMed

    Levy, Becca R; Pilver, Corey; Chung, Pil H; Slade, Martin D

    2014-12-01

    Negative age stereotypes that older individuals assimilate from their culture predict detrimental outcomes, including worse physical function. We examined, for the first time, whether positive age stereotypes, presented subliminally across multiple sessions in the community, would lead to improved outcomes. Each of 100 older individuals (age=61-99 years, M=81) was randomly assigned to an implicit-positive-age-stereotype-intervention group, an explicit-positive-age-stereotype-intervention group, a combined implicit- and explicit-positive-age-stereotype-intervention group, or a control group. Interventions occurred at four 1-week intervals. The implicit intervention strengthened positive age stereotypes, which strengthened positive self-perceptions of aging, which, in turn, improved physical function. The improvement in these outcomes continued for 3 weeks after the last intervention session. Further, negative age stereotypes and negative self-perceptions of aging were weakened. For all outcomes, the implicit intervention's impact was greater than the explicit intervention's impact. The physical-function effect of the implicit intervention surpassed a previous study's 6-month-exercise-intervention's effect with participants of similar ages. The current study's findings demonstrate the potential of directing implicit processes toward physical-function enhancement over time.

  13. Transit times and mean ages for nonautonomous and autonomous compartmental systems

    SciTech Connect

    Rasmussen, Martin; Hastings, Alan; Smith, Matthew J.; Agusto, Folashade B.; Chen-Charpentier, Benito M.; Hoffman, Forrest M.; Jiang, Jiang; Todd-Brown, Katherine E. O.; Wang, Ying; Wang, Ying-Ping; Luo, Yiqi

    2016-04-01

    We develop a theory for residence times and mean ages for nonautonomous compartmental systems. Using the McKendrick–von Forster equation, we show that the mean ages of mass in a compartmental system satisfy a linear nonautonomous ordinary differential equation that is exponentially stable. We then define a nonautonomous version of residence time as the mean age of mass leaving the compartmental system at a particular time and show that our nonautonomous theory is consistent with the autonomous case. We apply these results to study a nine-dimensional nonautonomous compartmental system modeling the carbon cycle, which is a simplified version of the Carnegie–Ames–Stanford approach (CASA) model.

  14. Spent graphite fuel element processing

    SciTech Connect

    Holder, N.D.; Olsen, C.W.

    1981-07-01

    The Department of Energy currently sponsors two programs to demonstrate the processing of spent graphite fuel elements. General Atomic in San Diego operates a cold pilot plant to demonstrate the processing of both US and German high-temperature reactor fuel. Exxon Nuclear Idaho Company is demonstrating the processing of spent graphite fuel elements from Rover reactors operated for the Nuclear Rocket Propulsion Program. This work is done at Idaho National Engineering Laboratory, where a hot facility is being constructed to complete processing of the Rover fuel. This paper focuses on the graphite combustion process common to both programs.

  15. Spent-fuel-storage alternatives

    SciTech Connect

    Not Available

    1980-01-01

    The Spent Fuel Storage Alternatives meeting was a technical forum in which 37 experts from 12 states discussed storage alternatives that are available or are under development. The subject matter was divided into the following five areas: techniques for increasing fuel storage density; dry storage of spent fuel; fuel characterization and conditioning; fuel storage operating experience; and storage and transport economics. Nineteen of the 21 papers which were presented at this meeting are included in this Proceedings. These have been abstracted and indexed. (ATT)

  16. Spent Fuel Working Group Report. Volume 1

    SciTech Connect

    O`Toole, T.

    1993-11-01

    The Department of Energy is storing large amounts of spent nuclear fuel and other reactor irradiated nuclear materials (herein referred to as RINM). In the past, the Department reprocessed RINM to recover plutonium, tritium, and other isotopes. However, the Department has ceased or is phasing out reprocessing operations. As a consequence, Department facilities designed, constructed, and operated to store RINM for relatively short periods of time now store RINM, pending decisions on the disposition of these materials. The extended use of the facilities, combined with their known degradation and that of their stored materials, has led to uncertainties about safety. To ensure that extended storage is safe (i.e., that protection exists for workers, the public, and the environment), the conditions of these storage facilities had to be assessed. The compelling need for such an assessment led to the Secretary`s initiative on spent fuel, which is the subject of this report. This report comprises three volumes: Volume I; Summary Results of the Spent Fuel Working Group Evaluation; Volume II, Working Group Assessment Team Reports and Protocol; Volume III; Operating Contractor Site Team Reports. This volume presents the overall results of the Working Group`s Evaluation. The group assessed 66 facilities spread across 11 sites. It identified: (1) facilities that should be considered for priority attention. (2) programmatic issues to be considered in decision making about interim storage plans and (3) specific vulnerabilities for some of these facilities.

  17. Using prime-time animation to engage students in courses on aging.

    PubMed

    Curch, Lisa M

    2010-01-01

    Prime-time animation is a television genre that frequently reflects on issues that are significant in contemporary society, including aging issues. Using such programs to present aging-related content can be a constructive pedagogical device, offering a means of actively engaging students. This article provides a brief overview of the use of media, popular culture, and prime-time animation in college teaching and addresses specific issues in, as well as examples of, how such programs can be used in college courses, particularly aging courses. The article also reports on a small survey of students who were exposed to such a teaching technique in an undergraduate aging course. Results showed that, in general, students were positive about viewing prime-time animation videos in class and indicated that they found the viewings and associated assignments helpful for learning about concepts and issues in aging.

  18. Do Sources of Cigarettes among Adolescents Vary by Age over Time?

    ERIC Educational Resources Information Center

    Lenk, Kathleen M.; Toomey, Traci L.; Shi, Qun; Erickson, Darin J.; Forster, Jean L.

    2014-01-01

    Trends in sources of cigarettes among adolescents were assessed using data from a teen cohort (2000-2006). Five sources--bought from store, got from other teen, stole from others, bought from others, and got from an adult--were measured over time by age. The most common source among all ages was other teens. Fewer teens bought cigarettes from…

  19. Using Prime-Time Animation to Engage Students in Courses on Aging

    ERIC Educational Resources Information Center

    Curch, Lisa M.

    2010-01-01

    Prime-time animation is a television genre that frequently reflects on issues that are significant in contemporary society, including aging issues. Using such programs to present aging-related content can be a constructive pedagogical device, offering a means of actively engaging students. This article provides a brief overview of the use of…

  20. Age Differences in Goal Concordance, Time Use, and Well-Being

    ERIC Educational Resources Information Center

    Chen, Yiwei; Lee, Yue-Ting; Pethtel, Olivia L.; Gutowitz, Michael S.; Kirk, Robert M.

    2012-01-01

    The primary purpose of the present study was to investigate age differences in goal concordance, time use, and Well-Being. Past research has found that despite age-related decline in life circumstances (e.g., health), the Well-Being of older adults is as high as young adults. The present study used a novel approach to explore the Paradox of…

  1. Syllable-Timed Speech Treatment for School-Age Children Who Stutter: A Phase I Trial

    ERIC Educational Resources Information Center

    Andrews, Cheryl; O'Brian, Sue; Harrison, Elisabeth; Onslow, Mark; Packman, Ann; Menzies, Ross

    2012-01-01

    Purpose: This clinical trial determined the outcomes of a simple syllable-timed speech (STS) treatment for school-age children who stutter. Method: Participants were 10 children, ages 6-11 years, who stutter. Treatment involved training the children and their parents to use STS at near normal speech rates. The technique was practiced in the clinic…

  2. Age of Inhalant First Time Use and Its Association to the Use of Other Drugs

    ERIC Educational Resources Information Center

    Ding, Kele; Chang, G. Andy; Southerland, Ron

    2009-01-01

    Inhalants are the 4th most commonly abused drugs after alcohol, tobacco, and marijuana. Although inhalants are often referred as Gateway Drugs this hypothesis is less examined. Using the 2003 National Survey on Drug Use and Health data, age of first time inhalant use was compared with the age of onset of other drugs among 6466 inhalant users who…

  3. Experiencing Term-Time Employment as a Non-Traditional Aged University Student: A Welsh Study

    ERIC Educational Resources Information Center

    Mercer, Jenny; Clay, James; Etheridge, Leanne

    2016-01-01

    Engaging in term-time employment appears to be becoming a common feature of contemporary UK student life. This study examined the ways in which a cohort of full-time non-traditional aged students negotiated paid employment whilst pursuing a full-time higher education course in Wales. Taking a qualitative approach to explore this further,…

  4. Transit times and mean ages for nonautonomous and autonomous compartmental systems

    SciTech Connect

    Rasmussen, Martin; Hastings, Alan; Smith, Matthew J.; Agusto, Folashade B.; Chen-Charpentier, Benito M.; Hoffman, Forrest M.; Jiang, Jiang; Todd-Brown, Katherine E. O.; Wang, Ying; Wang, Ying -Ping; Luo, Yiqi

    2016-04-01

    In this study, we develop a theory for transit times and mean ages for nonautonomous compartmental systems. Using the McKendrick–von Förster equation, we show that the mean ages of mass in a compartmental system satisfy a linear nonautonomous ordinary differential equation that is exponentially stable. We then define a nonautonomous version of transit time as the mean age of mass leaving the compartmental system at a particular time and show that our nonautonomous theory generalises the autonomous case. We apply these results to study a nine-dimensional nonautonomous compartmental system modeling the terrestrial carbon cycle, which is a modification of the Carnegie–Ames–Stanford approach model, and we demonstrate that the nonautonomous versions of transit time and mean age differ significantly from the autonomous quantities when calculated for that model.

  5. Transit times and mean ages for nonautonomous and autonomous compartmental systems

    DOE PAGES

    Rasmussen, Martin; Hastings, Alan; Smith, Matthew J.; ...

    2016-04-01

    In this study, we develop a theory for transit times and mean ages for nonautonomous compartmental systems. Using the McKendrick–von Förster equation, we show that the mean ages of mass in a compartmental system satisfy a linear nonautonomous ordinary differential equation that is exponentially stable. We then define a nonautonomous version of transit time as the mean age of mass leaving the compartmental system at a particular time and show that our nonautonomous theory generalises the autonomous case. We apply these results to study a nine-dimensional nonautonomous compartmental system modeling the terrestrial carbon cycle, which is a modification of themore » Carnegie–Ames–Stanford approach model, and we demonstrate that the nonautonomous versions of transit time and mean age differ significantly from the autonomous quantities when calculated for that model.« less

  6. DNA methylation-based measures of biological age: meta-analysis predicting time to death

    PubMed Central

    Chen, Brian H.; Marioni, Riccardo E.; Colicino, Elena; Peters, Marjolein J.; Ward-Caviness, Cavin K.; Tsai, Pei-Chien; Roetker, Nicholas S.; Just, Allan C.; Demerath, Ellen W.; Guan, Weihua; Bressler, Jan; Fornage, Myriam; Studenski, Stephanie; Vandiver, Amy R.; Moore, Ann Zenobia; Tanaka, Toshiko; Kiel, Douglas P.; Liang, Liming; Vokonas, Pantel; Schwartz, Joel; Lunetta, Kathryn L.; Murabito, Joanne M.; Bandinelli, Stefania; Hernandez, Dena G.; Melzer, David; Nalls, Michael; Pilling, Luke C.; Price, Timothy R.; Singleton, Andrew B.; Gieger, Christian; Holle, Rolf; Kretschmer, Anja; Kronenberg, Florian; Kunze, Sonja; Linseisen, Jakob; Meisinger, Christine; Rathmann, Wolfgang; Waldenberger, Melanie; Visscher, Peter M.; Shah, Sonia; Wray, Naomi R.; McRae, Allan F.; Franco, Oscar H.; Hofman, Albert; Uitterlinden, André G.; Absher, Devin; Assimes, Themistocles; Levine, Morgan E.; Lu, Ake T.; Tsao, Philip S.; Hou, Lifang; Manson, JoAnn E.; Carty, Cara L.; LaCroix, Andrea Z.; Reiner, Alexander P.; Spector, Tim D.; Feinberg, Andrew P.; Levy, Daniel; Baccarelli, Andrea; van Meurs, Joyce; Bell, Jordana T.; Peters, Annette; Deary, Ian J.; Pankow, James S.; Ferrucci, Luigi; Horvath, Steve

    2016-01-01

    Estimates of biological age based on DNA methylation patterns, often referred to as “epigenetic age”, “DNAm age”, have been shown to be robust biomarkers of age in humans. We previously demonstrated that independent of chronological age, epigenetic age assessed in blood predicted all-cause mortality in four human cohorts. Here, we expanded our original observation to 13 different cohorts for a total sample size of 13,089 individuals, including three racial/ethnic groups. In addition, we examined whether incorporating information on blood cell composition into the epigenetic age metrics improves their predictive power for mortality. All considered measures of epigenetic age acceleration were predictive of mortality (p≤8.2×10−9), independent of chronological age, even after adjusting for additional risk factors (p<5.4×10−4), and within the racial/ethnic groups that we examined (non-Hispanic whites, Hispanics, African Americans). Epigenetic age estimates that incorporated information on blood cell composition led to the smallest p-values for time to death (p=7.5×10−43). Overall, this study a) strengthens the evidence that epigenetic age predicts all-cause mortality above and beyond chronological age and traditional risk factors, and b) demonstrates that epigenetic age estimates that incorporate information on blood cell counts lead to highly significant associations with all-cause mortality. PMID:27690265

  7. Opportunities to increase the productivity of spent fuel shipping casks in the United States

    SciTech Connect

    Winsor, G.H.; Faletti, D.W.; DeSteese, J.G.

    1980-03-01

    Trends indicate that future transportation requirements for spent fuel will be different from those anticipated when the current generation of casks and vehicles was designed. Increased storage capacity at most reactors will increase the average post irradiation age of the spent fuel to be transported. A scenario is presented which shows the 18 casks currently available should be sufficient until approximately 1983. Beyond this time, it appears that an adequate transportation system can be maintained by acquiring, as needed, casks of current designs and new casks currently under development. Spent fuel transportation requirements in the post-1990 period can be met by a new generation of casks specifically designed to transport long-cooled fuel. In terms of the number of casks needed, productivity may be increased by 19% if rail cask turnaround time is reduced to 4 days from the current range of 6.5 to 8.5 days. Productivity defined as payloads per cask year could be increased 62% if the turnaround time for legal weight truck casks were reduced from 12 hours to 4 hours. On a similar basis, overweight truck casks show a 28% increase in productivity.

  8. Effects of reaction time variability and age on brain activity during Stroop task performance.

    PubMed

    Tam, Angela; Luedke, Angela C; Walsh, Jeremy J; Fernandez-Ruiz, Juan; Garcia, Angeles

    2015-09-01

    Variability in reaction time during task performance may reflect fluctuations in attention and cause reduced performance in goal-directed tasks, yet it is unclear whether the mechanisms behind this phenomenon change with age. Using fMRI, we tested young and cognitively healthy older adults with the Stroop task to determine whether aging affects the neural mechanisms underlying intra-individual reaction time variability. We found significant between-group differences in BOLD activity modulated by reaction time. In older adults, longer reaction times were associated with greater activity in frontoparietal attentional areas, while in younger adults longer reaction times were associated with greater activity in default mode network areas. Our results suggest that the neural correlates of reaction time variability change with healthy aging, reinforcing the concept of functional plasticity to maintain high cognitive function throughout the lifespan.

  9. Diverse Family Types and Out-Of-School Learning Time of Young School Age Children

    PubMed Central

    Ono, Hiromi

    2010-01-01

    =Sources of differentials in out-of-school learning time between children in first marriage biological parent families and children in six nontraditional family types are identified. Analyses of time diaries reveal that children in four of the six nontraditional family types spend fewer minutes learning than do children in first marriage biological parent families. In all four cases, however, the differentials are explained by the presence of siblings age 18+, lower levels of family income, or younger maternal age. PMID:21532970

  10. In vitro 3-D model based on extending time of culture for studying chronological epidermis aging.

    PubMed

    Dos Santos, Morgan; Metral, Elodie; Boher, Aurélie; Rousselle, Patricia; Thepot, Amélie; Damour, Odile

    2015-09-01

    Skin aging is a complex phenomenon in which several mechanisms operate simultaneously. Among them, intrinsic aging is a time-dependent process, which leads to gradual skin changes affecting its structure and function such as thinning down of both epidermal and dermal compartments and a flattening and fragility of the dermo-epidermal junction. Today, several approaches have been proposed for the generation of aged skin in vitro, including skin explants from aged donors and three-dimensional skin equivalent treated by aging-inducing chemical compounds or engineered with human cells isolated from aged donors. The aim of this study was to develop and validate a new in vitro model of aging based on skin equivalent demonstrating the same phenotypic changes that were observed in chronological aging. By using prolonged culture as a proxy for cellular aging, we extended to 120 days the culture time of a skin equivalent model based on collagen-glycosaminoglycan-chitosan porous polymer and engineered with human skin cells from photo-protected sites of young donors. Morphological, immunohistological and ultrastructural analysis at different time points of the culture allowed characterizing the phenotypic changes observed in our model in comparison to samples of non photo-exposed normal human skin from different ages. We firstly confirmed that long-term cultured skin equivalents are still morphologically consistent and functionally active even after 120 days of culture. However, similar to in vivo chronological skin aging a significant decrease of the epidermis thickness as well as the number of keratinocyte expressing proliferation marker Ki67 are observed in extended culture time skin equivalent. Epidermal differentiation markers loricrin, filaggrin, involucrin and transglutaminase, also strongly decreased. Ultrastructural analysis of basement membrane showed typical features of aged skin such as duplication of lamina densa and alterations of hemidesmosomes. Moreover, the

  11. 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.

  12. Spent fuel characteristics & disposal considerations

    SciTech Connect

    Oversby, V.M.

    1996-06-01

    The fuel used in commercial nuclear power reactors is uranium, generally in the form of an oxide. The gas-cooled reactors developed in England use metallic uranium enclosed in a thin layer of Magnox. Since this fuel must be processed into a more stable form before disposal, we will not consider the characteristics of the Magnox spent fuel. The vast majority of the remaining power reactors in the world use uranium dioxide pellets in Zircaloy cladding as the fuel material. Reactors that are fueled with uranium dioxide generally use water as the moderator. If ordinary water is used, the reactors are called Light Water Reactors (LWR), while if water enriched in the deuterium isotope of hydrogen is used, the reactors are called Heavy Water reactors. The LWRs can be either pressurized reactors (PWR) or boiling water reactors (BWR). Both of these reactor types use uranium that has been enriched in the 235 isotope to about 3.5 to 4% total abundance. There may be minor differences in the details of the spent fuel characteristics for PWRs and BWRs, but for simplicity we will not consider these second-order effects. The Canadian designed reactor (CANDU) that is moderated by heavy water uses natural uranium without enrichment of the 235 isotope as the fuel. These reactors run at higher linear power density than LWRs and produce spent fuel with lower total burn-up than LWRs. Where these difference are important with respect to spent fuel management, we will discuss them. Otherwise, we will concentrate on spent fuel from LWRs.

  13. Age-dependent inhibition of pentobarbital sleeping time by ozone in mice and rats

    SciTech Connect

    Canada, A.T.; Calabrese, E.J.; Leonard, D.

    1986-09-01

    The effect of age on the metabolism of pentobarbital in mice and rats was investigated following exposure to 0.3 ppm of ozone for 3.75 hr. Young animals were 2.5 months of age and the mature were 18 months. The pentobarbital sleeping time was significantly prolonged following the ozone exposure in both the mice and rats when compared with an air control. No ozone effect on sleeping time was found in the young animals. The results indicate that there may be an age-related sensitivity to the occurrence of ozone-related inhibition of pentobarbital metabolism.

  14. Age-related slowing of response selection and production in a visual choice reaction time task

    PubMed Central

    Woods, David L.; Wyma, John M.; Yund, E. William; Herron, Timothy J.; Reed, Bruce

    2015-01-01

    Aging is associated with delayed processing in choice reaction time (CRT) tasks, but the processing stages most impacted by aging have not been clearly identified. Here, we analyzed CRT latencies in a computerized serial visual feature-conjunction task. Participants responded to a target letter (probability 40%) by pressing one mouse button, and responded to distractor letters differing either in color, shape, or both features from the target (probabilities 20% each) by pressing the other mouse button. Stimuli were presented randomly to the left and right visual fields and stimulus onset asynchronies (SOAs) were adaptively reduced following correct responses using a staircase procedure. In Experiment 1, we tested 1466 participants who ranged in age from 18 to 65 years. CRT latencies increased significantly with age (r = 0.47, 2.80 ms/year). Central processing time (CPT), isolated by subtracting simple reaction times (SRT) (obtained in a companion experiment performed on the same day) from CRT latencies, accounted for more than 80% of age-related CRT slowing, with most of the remaining increase in latency due to slowed motor responses. Participants were faster and more accurate when the stimulus location was spatially compatible with the mouse button used for responding, and this effect increased slightly with age. Participants took longer to respond to distractors with target color or shape than to distractors with no target features. However, the additional time needed to discriminate the more target-like distractors did not increase with age. In Experiment 2, we replicated the findings of Experiment 1 in a second population of 178 participants (ages 18–82 years). CRT latencies did not differ significantly in the two experiments, and similar effects of age, distractor similarity, and stimulus-response spatial compatibility were found. The results suggest that the age-related slowing in visual CRT latencies is largely due to delays in response selection and

  15. The impact of age at death on the lag time of radiocarbon values in human bone.

    PubMed

    Ubelaker, Douglas H; Thomas, Christian; Olson, Jacqueline E

    2015-06-01

    Analysis of modern bomb-pulse radiocarbon in human bone offers data needed to interpret the post-mortem interval in skeletonized human remains recovered from forensic contexts. Radiocarbon analysis of different tissues with distinct rates of remodeling allows proper placement of the values on the modern bomb-curve. However, the lag time between the date of intercept on the curve and the actual death date is largely affected by the age at death. Published data on radiocarbon analysis of individuals of known age at death and death dates indicate that this lag time increases with age until about 60 years. The lag time documented for each decade of life can be used to compensate for this age-related factor and increase the accuracy of interpretation of the death date. While this method could be greatly improved by original research with a larger sample size, this study provides an adequate point from which to launch further investigations into the subject.

  16. Ergodicity breaking, ageing, and confinement in generalized diffusion processes with position and time dependent diffusivity

    NASA Astrophysics Data System (ADS)

    Cherstvy, Andrey G.; Metzler, Ralf

    2015-05-01

    We study generalized anomalous diffusion processes whose diffusion coefficient D(x, t) ∼ D0|x|αtβ depends on both the position x of the test particle and the process time t. This process thus combines the features of scaled Brownian motion and heterogeneous diffusion parent processes. We compute the ensemble and time averaged mean squared displacements of this generalized diffusion process. The scaling exponent of the ensemble averaged mean squared displacement is shown to be the product of the critical exponents of the parent processes, and describes both subdiffusive and superdiffusive systems. We quantify the amplitude fluctuations of the time averaged mean squared displacement as function of the length of the time series and the lag time. In particular, we observe a weak ergodicity breaking of this generalized diffusion process: even in the long time limit the ensemble and time averaged mean squared displacements are strictly disparate. When we start to observe this process some time after its initiation we observe distinct features of ageing. We derive a universal ageing factor for the time averaged mean squared displacement containing all information on the ageing time and the measurement time. External confinement is shown to alter the magnitudes and statistics of the ensemble and time averaged mean squared displacements.

  17. Age of the mother as a risk factor and timing of hypospadias repair according to severity

    PubMed Central

    Jorge, Juan Carlos; Pérez-Brayfield, Marcos Raymond; Torres, Camille M.; Piñeyro-Ruiz, Coriness; Torres, Naillil

    2016-01-01

    Background & Objectives Hypospadias is characterized by a displacement of the urethral opening in males that can change from the typical position within the glans penis to a subcoronal position (Type I), to anywhere along the ventral shaft (Type II), to penoscrotal, scrotal, or perineal positions (Type III). We and others have previously reported that age of the mother (≥ 40 years old) is a risk factor for having a child with hypospadias, but there is a scarcity of reports on whether such risk is higher for having a child with the mild (Type I) or the more severe forms (Types II and III). In addition, we aimed to assess the timing of hypospadias repair according to severity. Methods Parents of children with hypospadias were interviewed by using a series of questionnaires (n = 128 cases). Severity was confirmed in the clinic and age of the mother was self-reported. Number of surgeries, age of child by the first and the last intervention was also assessed. Ordered logistic regression and the Brant test were employed to calculate risk between mild (Type I) and severe cases (Types II and III), and the assumption of proportional odds, respectively. The Mann-Whitney U Test was used to compare number of surgeries and age by the last repair between mild and severe cases. One-way ANOVA was employed to compare age of the child at the time of first surgery across severities (Types I - III). Results Women ≥ 40 years of age are 3.89 times [95% CI: 1.20-12.64] at a higher risk for having a child with the more severe forms of the condition than younger women. Repair of Type I was accomplished with 1 intervention whereas more severe cases required 1 – 4 (2 ± 0.5) surgical interventions. The timing for hypospadias repair of Type I cases occurred at an average age of 16.2 ± 4.88 months, of Type II cases occurred at an average age of 20.3 ± 8.15 months whereas the average age of the first hypospadias repair among Type III cases was 12.68 ± 2.52 months. Number of surgeries

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  19. The Relationship of Time Perspective to Age, Gender, and Academic Achievement among Academically Talented Adolescents

    ERIC Educational Resources Information Center

    Mello, Zena R.; Worrell, Frank C.

    2006-01-01

    Time perspective is a useful psychological construct associated with educational outcomes (Phalet, Andriessen, & Lens, 2004) and may prove fruitful for research focusing on academically talented adolescents. Thus, the relationship of time perspective to age, gender, and academic achievement was examined among 722 academically talented middle and…

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  1. Metals removal from spent salts

    DOEpatents

    Hsu, Peter C.; Von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Brummond, William A.; Adamson, Martyn G.

    2002-01-01

    A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.

  2. Actinide removal from spent salts

    DOEpatents

    Hsu, Peter C.; von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Adamson, Martyn G.

    2002-01-01

    A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

  3. Spent-fuel storage requirements

    NASA Astrophysics Data System (ADS)

    1982-06-01

    Spent fuel storage requirements, as projected through the year 2000 for U.S. LWRs, were calculated using information supplied by the utilities reflecting plant status as of December 31, 1981. Projections through the year 2000 combined fuel discharge projections of the utilities with the assumed discharges of typical reactors required to meet the nuclear capacity of 165 GWe projected by the Energy Information Administration for the year 2000. Three cases were developed and are summarized. A reference case, or maximum at-reactor capacity case, assumes that all reactor storage pools are increased to their maximum capacities as estimated by the utilities for spent fuel storage utilizing currently licensed technologies. The reference case assumes no transshipments between pools except as current licensed by the Nuclear Regulatory Commission. This case identifies an initial requirement for 13 MTU of additional storage in 1984, and a cumulative requirement for 14,490 MTU additional storage in the year 2000.

  4. Estimating Black Carbon Aging Time-Scales with a Particle-Resolved Aerosol Model

    SciTech Connect

    Riemer, Nicole; West, Matt; Zaveri, Rahul A.; Easter, Richard C.

    2010-01-13

    Understanding the aging process of aerosol particles is important for assessing their chemical reactivity, cloud condensation nuclei activity, radiative properties and health impacts. In this study we investigate the aging of black carbon containing particles in an idealized urban plume using a new approach, the particleresolved aerosol model PartMC-MOSAIC. We present a method to estimate aging time-scales using an aging criterion based on cloud condensation nuclei activation. The results show a separation into a daytime regime where condensation dominates and a nighttime regime where coagulation dominates. For the chosen urban plume scenario, depending on the supersaturation threshold, the values for the aging timescales vary between 0.06 hours and 10 hours during the day, and between 6 hours and 20 hours during the night.

  5. TIME PERSPECTIVE AND EXERCISE, OBESITY AND SMOKING: MODERATION OF ASSOCIATIONS BY AGE

    PubMed Central

    Guthrie, LC; Butler, SC; Lessl, K; Ochi, O; Ward, MM

    2014-01-01

    Purpose Time perspective, a psychological construct denoting subjective orientation to either present or future concerns, has been inconsistently associated with healthy behaviors in adults. We hypothesized that associations would be stronger in young adults, who are first developing independent attitudes, than in older adults. Design Cross-sectional survey. Setting Three cities in the Mid-Atlantic region. Subjects 790 patrons of barber and beauty shops. Measures Zimbardo Time Perspective Inventory future, present-fatalistic, and present-hedonistic subscales, current smoking, days per week of recreational exercise, and height and weight, by self-report. Analysis We tested if associations between time perspective and exercise, obesity, and current smoking differed by age group (18–24 years, 25–34 years, and 35 and older) using analysis of variance and logistic regression. Results Higher future time perspective scores, indicating greater focus on future events, was associated with more frequent exercise, while higher present-fatalistic time perspective scores, indicating more hopelessness, was associated with less frequent exercise in 18 – 24 year olds, but not in older individuals. Lower future time perspective scores, and higher present-hedonistic time perspective scores, indicating interest in pleasure-seeking, were also associated with obesity only in 18 – 24 year olds. Current smoking was not related to time perspective in any age group. Conclusion Time perspective has age-specific associations with exercise and obesity, suggesting stages when time perspective may influence health behavior decision-making. PMID:24200252

  6. Age-Based Methods to Explore Time-Related Variables in Occupational Epidemiology Studies

    SciTech Connect

    Janice P. Watkins, Edward L. Frome, Donna L. Cragle

    2005-08-31

    Although age is recognized as the strongest predictor of mortality in chronic disease epidemiology, a calendar-based approach is often employed when evaluating time-related variables. An age-based analysis file, created by determining the value of each time-dependent variable for each age that a cohort member is followed, provides a clear definition of age at exposure and allows development of diverse analytic models. To demonstrate methods, the relationship between cancer mortality and external radiation was analyzed with Poisson regression for 14,095 Oak Ridge National Laboratory workers. Based on previous analysis of this cohort, a model with ten-year lagged cumulative radiation doses partitioned by receipt before (dose-young) or after (dose-old) age 45 was examined. Dose-response estimates were similar to calendar-year-based results with elevated risk for dose-old, but not when film badge readings were weekly before 1957. Complementary results showed increasing risk with older hire ages and earlier birth cohorts, since workers hired after age 45 were born before 1915, and dose-young and dose-old were distributed differently by birth cohorts. Risks were generally higher for smokingrelated than non-smoking-related cancers. It was difficult to single out specific variables associated with elevated cancer mortality because of: (1) birth cohort differences in hire age and mortality experience completeness, and (2) time-period differences in working conditions, dose potential, and exposure assessment. This research demonstrated the utility and versatility of the age-based approach.

  7. Spent fuel receipt scenarios study

    SciTech Connect

    Ballou, L.B.; Montan, D.N.; Revelli, M.A.

    1990-09-01

    This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs.

  8. Spent fuel data for waste storage programs

    SciTech Connect

    Greene, E M

    1980-09-01

    Data on LWR spent fuel were compiled for dissemination to participants in DOE-sponsored waste storage programs. Included are mechanical descriptions of the existing major types of LWR fuel assemblies, spent LWR fuel fission product inventories and decay heat data, and inventories of LWR spent fuel currently in storage, with projections of future quantities.

  9. Cognitive Aging and Time Perception: Roles of Bayesian Optimization and Degeneracy

    PubMed Central

    Turgeon, Martine; Lustig, Cindy; Meck, Warren H.

    2016-01-01

    This review outlines the basic psychological and neurobiological processes associated with age-related distortions in timing and time perception in the hundredths of milliseconds-to-minutes range. The difficulty in separating indirect effects of impairments in attention and memory from direct effects on timing mechanisms is addressed. The main premise is that normal aging is commonly associated with increased noise and temporal uncertainty as a result of impairments in attention and memory as well as the possible reduction in the accuracy and precision of a central timing mechanism supported by dopamine-glutamate interactions in cortico-striatal circuits. Pertinent to these findings, potential interventions that may reduce the likelihood of observing age-related declines in timing are discussed. Bayesian optimization models are able to account for the adaptive changes observed in time perception by assuming that older adults are more likely to base their temporal judgments on statistical inferences derived from multiple trials than on a single trial’s clock reading, which is more susceptible to distortion. We propose that the timing functions assigned to the age-sensitive fronto-striatal network can be subserved by other neural networks typically associated with finely-tuned perceptuo-motor adjustments, through degeneracy principles (different structures serving a common function). PMID:27242513

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  11. How young children spend their time: television and other activities.

    PubMed

    Huston, A C; Wright, J C; Marquis, J; Green, S B

    1999-07-01

    Time-use diaries were collected over a 3-year period for 2 cohorts of 2- and 4-year-old children. TV viewing declined with age. Time spent in reading and educational activities increased with age on weekdays but declined on weekends. Time-use patterns were sex-stereotyped, and sex differences increased with age. As individuals' time in educational activities, social interaction, and video games increased, their time watching entertainment TV declined, but time spent playing covaried positively with entertainment TV. Educational TV viewing was not related to time spent in non-TV activities. Maternal education and home environment quality predicted frequent viewing of educational TV programs and infrequent viewing of entertainment TV. The results do not support a simple displacement hypothesis; the relations of TV viewing to other activities depend on the program content, the nature of the competing activity, and the environmental context.

  12. Criticality of spent reactor fuel

    SciTech Connect

    Harris, D.R.

    1987-01-01

    The storage capacity of spent reactor fuel pools can be greatly increased by consolidation. In this process, the fuel rods are removed from reactor fuel assemblies and are stored in close-packed arrays in a canister or skeleton. An earlier study examined criticality consideration for consolidation of Westinghouse fuel, assumed to be fresh, in canisters at the Millstone-2 spent-fuel pool and in the General Electric IF-300 shipping cask. The conclusions were that the fuel rods in the canister are so deficient in water that they are adequately subcritical, both in normal and in off-normal conditions. One potential accident, the water spill event, remained unresolved in the earlier study. A methodology is developed here for spent-fuel criticality and is applied to the water spill event. The methodology utilizes LEOPARD to compute few-group cross sections for the diffusion code PDQ7, which then is used to compute reactivity. These codes give results for fresh fuel that are in good agreement with KENO IV-NITAWL Monte Carlo results, which themselves are in good agreement with continuous energy Monte Carlo calculations. These methodologies are in reasonable agreement with critical measurements for undepleted fuel.

  13. The impact of male age on embryo quality: a retrospective study using time-lapse imaging

    PubMed Central

    Rosário, Guilherme R. F.; Vidal, Diana S.; Silva, Adriana V.; Franco, Antônio C. C.

    2016-01-01

    Objective This study aimed to correlate male age with embryo morphokinetic parameters on D3 considering the timing and the exact moment of embryo cleavage. Methods Time-lapse imaging was used to produce an ideal cleavage curve for the embryos analyzed. The percentage of embryos under the curve was analyzed and correlated with male age. Results 32.6% of the embryos from patients aged 28-33 years were under the curve; 36.2% of the embryos from patients aged 34-39 years were under the curve; 41.3% of the embryos from patients aged 40-45 years were under the curve; and 26.3% of the embryos fro patients aged 46-57 years were under the curve. Conclusions a statistically non-significant decrease was observed in the percentage of embryos under the optimal cleavage curve on D3 in the group of men aged between 40 and 45 years. Further studies looking into embryos in the blastocyst stage (D5 or D6) are required. PMID:28050955

  14. Wolf (Canis lupus) Generation Time and Proportion of Current Breeding Females by Age

    PubMed Central

    2016-01-01

    Information is sparse about aspects of female wolf (Canis lupus) breeding in the wild, including age of first reproduction, mean age of primiparity, generation time, and proportion of each age that breeds in any given year. We studied these subjects in 86 wolves (113 captures) in the Superior National Forest (SNF), Minnesota (MN), during 1972–2013 where wolves were legally protected for most of the period, and in 159 harvested wolves from throughout MN wolf range during 2012–2014. Breeding status of SNF wolves were assessed via nipple measurements, and wolves from throughout MN wolf range, by placental scars. In the SNF, proportions of currently breeding females (those breeding in the year sampled) ranged from 19% at age 2 to 80% at age 5, and from throughout wolf range, from 33% at age 2 to 100% at age 7. Excluding pups and yearlings, only 33% to 36% of SNF females and 58% of females from throughout MN wolf range bred in any given year. Generation time for SNF wolves was 4.3 years and for MN wolf range, 4.7 years. These findings will be useful in modeling wolf population dynamics and in wolf genetic and dog-domestication studies. PMID:27258193

  15. Breed, slaughter weight and ageing time effects on consumer appraisal of three muscles of lamb.

    PubMed

    Martínez-Cerezo, S; Sañudo, C; Panea, B; Olleta, J L

    2005-04-01

    Consumers (n=265) tasted semitendinosus (ST), semimembranosus (SM) and gluteo biceps (GB) (right and left) from 180 entire male lambs. Muscles were from three Spanish breeds: Rasa Aragonesa (local meat breed), Churra (local dairy breed) and Spanish Merino. Within breed, three slaughter live weights were considered (10-12, 20-22 or 30-32 kg). Isolated muscles were aged under vacuum package for 1, 2, 4, 8 or 16 days. Consumers evaluated tenderness, flavour quality and overall acceptability. Globally, the three attributes were significantly influenced by breed, slaughter live weight and ageing. Considering breed effect, Churra had the lowest scores for tenderness in the heaviest lambs while Spanish Merino was the most tender at 20-22 kg but there were no differences between either for 10-12 kg lambs. Muscles from the heaviest lambs were considered the toughest and those from the 10-12 kg lambs the most tender. Tenderness improved with ageing, but more for SM and GB. Flavour was better in the lightest lambs and, in general, it was not affected negatively by ageing. Consumers preferred meat from the 10-12 kg lambs in all breeds (the most tender and with the best flavour) and aged for intermediate to long periods (4-16 days). For the three attributes, the ST muscle had the best ratings at short ageing times and GB at long ageing times.

  16. Wolf (Canis lupus) generation time and proportion of current breeding females by age

    USGS Publications Warehouse

    Mech, L. David; Barber-Meyer, Shannon M.; Erb, John

    2016-01-01

    Information is sparse about aspects of female wolf (Canis lupus) breeding in the wild, including age of first reproduction, mean age of primiparity, generation time, and proportion of each age that breeds in any given year. We studied these subjects in 86 wolves (113 captures) in the Superior National Forest (SNF), Minnesota (MN), during 1972–2013 where wolves were legally protected for most of the period, and in 159 harvested wolves from throughout MN wolf range during 2012–2014. Breeding status of SNF wolves were assessed via nipple measurements, and wolves from throughout MN wolf range, by placental scars. In the SNF, proportions of currently breeding females (those breeding in the year sampled) ranged from 19% at age 2 to 80% at age 5, and from throughout wolf range, from 33% at age 2 to 100% at age 7. Excluding pups and yearlings, only 33% to 36% of SNF females and 58% of females from throughout MN wolf range bred in any given year. Generation time for SNF wolves was 4.3 years and for MN wolf range, 4.7 years. These findings will be useful in modeling wolf population dynamics and in wolf genetic and dog-domestication studies.

  17. Role of Aging and Hippocampus in Time-Place Learning: Link to Episodic-Like Memory?

    PubMed Central

    Mulder, C. K.; Gerkema, M. P.; Van der Zee, E. A.

    2016-01-01

    Introduction: With time-place learning (TPL), animals link an event with the spatial location and the time of day (TOD). The what–where–when TPL components make the task putatively episodic-like in nature. Animals use an internal sense of time to master TPL, which is circadian system based. Finding indications for a role of the hippocampus and (early) aging-sensitivity in TPL would strengthen the episodic-like memory nature of the paradigm. Methods: Previously, we used C57Bl/6 mice for our TPL research. Here, we used CD1 mice which are less hippocampal-driven and age faster compared to C57Bl/6 mice. To demonstrate the low degree of hippocampal-driven performance in CD1 mice, a cross maze was used. The spontaneous alternation test was used to score spatial working memory in CD1 mice at four different age categories (young (3–6 months), middle-aged (7–11 months), aged (12–18 months) and old (>19 months). TPL performance of middle-aged and aged CD1 mice was tested in a setup with either two or three time points per day (2-arm or 3-arm TPL task). Immunostainings were applied on brains of young and middle-aged C57Bl/6 mice that had successfully mastered the 3-arm TPL task. Results: In contrast to C57Bl/6 mice, middle-aged and aged CD1 mice were less hippocampus-driven and failed to master the 3-arm TPL task. They could, however, master the 2-arm TPL task primarily via an ordinal (non-circadian) timing system. c-Fos, CRY2, vasopressin (AVP), and phosphorylated cAMP response element-binding protein (pCREB) were investigated. We found no differences at the level of the suprachiasmatic nucleus (SCN; circadian master clock), whereas CRY2 expression was increased in the hippocampal dentate gyrus (DG). The most pronounced difference between TPL trained and control mice was found in c-Fos expression in the paraventricular thalamic nucleus, a circadian system relay station. Conclusions: These results further indicate a key role of CRY proteins in TPL and confirm the

  18. Aging of nickel added to soils as predicted by soil pH and time.

    PubMed

    Ma, Yibing; Lombi, Enzo; McLaughlin, Mike J; Oliver, Ian W; Nolan, Annette L; Oorts, Koen; Smolders, Erik

    2013-08-01

    Although aging processes are important in risk assessment for metals in soils, the aging of Ni added to soils has not been studied in detail. In this study, after addition of water soluble Ni to soils, the changes over time in isotopic exchangeability, total concentrations and free Ni(2+) activity in soil pore water, were investigated in 16 European soils incubated outdoors for 18 months. The results showed that after Ni addition, concentrations of Ni in soil pore water and isotopic exchangeability of Ni in soils initially decreased rapidly. This phase was followed by further decreases in the parameters measured but these occurred at slower rates. Increasing soil pH increased the rate and extent of aging reactions. Semi-mechanistic models, based on Ni precipitation/nucleation on soil surfaces and micropore diffusion, were developed and calibrated. The initial fast processes, which were attributed to precipitation/nucleation, occurred over a short time (e.g. 1h), afterwards the slow processes were most likely controlled by micropore diffusion processes. The models were validated by comparing predicted and measured Ni aging in three additional, widely differing soils aged outdoors for periods up to 15 months in different conditions. These models could be used to scale ecotoxicological data generated in short-term studies to longer aging times.

  19. The Evolution of the Age at Menarche from Prehistorical to Modern Times.

    PubMed

    Papadimitriou, Anastasios

    2016-12-01

    Menarche denotes the onset of the female reproductive capacity. The age that menarche occurs is mostly attributed to the interaction of genetics and various environmental factors. Herein, the author describes the evolution of the age at menarche from prehistoric to the present times. Data from skeletal remains suggest that in the Paleolithic woman menarche occurred at an age between 7 and 13 years, early sexual maturation being a trade-off for reduced life expectancy. In the classical, as well as in the medieval years, the age at menarche was generally reported to be at approximately 14 years, with a range from 12 to 15 years. A significant retardation of the age at menarche occurred in the beginning of the modern times, soon after the industrial revolution, due to the deterioration of the living conditions, with most studies reporting menarche to occur at 15-16 years. In the 20th century, especially in the second half of it, in the industrialized countries, the age at menarche decreased significantly, as a result of the improvement of the socioeconomic conditions, occurring at 12-13 years. In the present times, in the developed countries, this trend seems to slow down or level off.

  20. Influence of age and hypertension treatment-time on ambulatory blood pressure in hypertensive patients.

    PubMed

    Hermida, Ramón C; Ayala, Diana E; Crespo, Juan J; Mojón, Artemio; Chayán, Luisa; Fontao, María J; Fernández, José R

    2013-03-01

    Some studies based on ambulatory blood pressure (BP) monitoring (ABPM) have reported a reduction in sleep-time relative BP decline towards a more non-dipping pattern in the elderly, but rarely have past studies included a proper comparison with younger subjects, and no previous report has evaluated the potential role of hypertension treatment time on nighttime BP regulation in the elderly. Accordingly, we evaluated the influence of age and time-of-day of hypertension treatment on the circadian BP pattern assessed by 48-h ABPM. This cross-sectional study involved 6147 hypertensive patients (3108 men/3039 women), 54.0 ± 13.7 (mean ± SD) yrs of age, with 2137 (978 men/1159 women) being ≥60 yrs of age. At the time of study, 1809 patients were newly diagnosed and untreated, and 4338 were treated with hypertension medications. Among the later, 2641 ingested all their prescribed BP-lowering medications upon awakening, whereas 1697 ingested the full daily dose of ≥1 hypertension medications at bedtime. Diagnosis of hypertension in untreated patients was based on ABPM criteria, specifically an awake systolic (SBP)/diastolic (DBP) BP mean ≥135/85 mm Hg and/or an asleep SBP/DBP mean ≥120/70 mm Hg. Collectively, older in comparison with younger patients were more likely to have diagnoses of microalbuminuria, chronic kidney disease, obstructive sleep apnea, metabolic syndrome, anemia, and/or obesity. In addition, the group of older vs. younger patients had higher glucose, creatinine, uric acid, triglycerides, and fibrinogen, but lower cholesterol, hemoglobin, and estimated glomerular filtration rate. In older compared with younger patients, ambulatory SBP was significantly higher and DBP significantly lower (p < .001), mainly during the hours of nighttime sleep and initial hours after morning awakening. The prevalence of non-dipping was significantly higher in older than younger patients (63.1% vs. 41.1%; p < .001). The largest difference between

  1. Cutaneous Resonance Running Time Varies with Age, Body Site and Gender in a Normal Chinese Population

    PubMed Central

    Xin, Shujun; Man, Wenyan; Fluhr, Joachim W.; Song, Shunpeng; Elias, Peter M; Man, Mao-Qiang

    2010-01-01

    Background/objectives One phenomenon of skin aging is loss of cutaneous elasticity. Measurement of cutaneous resonance running time (CRRT) is a method to assess skin elasticity. Yet, information regarding directional changes of CRRT associated with age, body sites and gender is not yet available. In the present study, we assessed whether changes in CRRT vary with age, body sites and gender in a normal Chinese population. Methods A Reviscometer was used to measure CRRTs in various directions on the left dorsal hand, the forehead and the left canthus of 806 normal Chinese volunteers, aged 2.5-94 years. Results With aging, CRRTs decreased in all directions on the hand, the forehead, and the canthus. A more dramatic reduction of CRRTs on the forehead and the canthus were observed at both the 2–8 and 3–9 o’clock directions. CRRTs in males aged 11– 20 years old were longer than those in females at some directions on all three body sites. Females between 21 and 40 years old showed longer CRRTs than males in some directions of the hand. There were no gender differences in subjects aged 0–10 (except on the canthus) and over 81 years old. Conclusion CRRTs vary with age, body sites and gender. PMID:21039906

  2. Striking effect of time variation in the estimation of groundwater age in the Wairarapa valley

    NASA Astrophysics Data System (ADS)

    Petrus, Karine; Toews, Michael; Daughney, Christopher; Cornaton, Fabien

    2014-05-01

    The Wairarapa Valley exhibits complex interactions between its rivers and shallow aquifers. With agriculture being an essential part of the region the risk of contamination and depletion of groundwater exists. In order to assist with water resource management in the region, we can do predictions with the help of numerical models. Among these predictions, the evaluation of groundwater age is critical for decision making. This project builds on work done by Greater Wellington Regional Council and will focus on the Wairarapa Valley. The aim of this study is to evaluate the age of the groundwater in the Wairarapa region. Investigations have already been done thanks to hydrochemistry. However radiometric age can be misleading in the sense that it does not consider the mixing process in the motion of groundwater particules. Therefore another approach can be considered .This latter is physic based by considering the age as a property that we transport through two main processes: advection at a macroscopic scale and diffusion at a microscopic scale. The determination of the distribution age by this approach has already been done for the Lake Rotorua but in the steady state case (cf Daughney). The unique contribution of the present study is to estimate the changes in groundwater age distribution through time within the region. Indeed transient simulations are needed to explicitly account for seasonally variable rainfall and pumping wells. This affects the simulated flow solution and then the simulated age solution. In order to solve numerically the transport of age distribution we have chosen to use the Time Marching Laplace Transform Galerkin technique which has been developed in a research code by Fabien Cornaton. The obtained results depict that temporal variations in groundwater age are present and have important implication for resource management

  3. Racial disparities in age at time of homicide victimization: a test of the multiple disadvantage model.

    PubMed

    Lo, Celia C; Howell, Rebecca J; Cheng, Tyrone C

    2015-01-01

    This study sought the factors associated with race/ethnicity disparities in the age at which homicide deaths tend to occur. We used the multiple disadvantage model to take race into account as we evaluated associations between age at time of homicide victimization and several social structural, mental health-related, and lifestyle factors. Data were derived from the 1993 National Mortality Followback Survey, a cross-sectional interview study of spouses, next of kin, other relatives, and close friends of individuals 15 years and older who died in the United States in 1993. Our results showed age at time of homicide mortality to be related to the three types of factors; race moderated some of these relationships. In general, being employed, married, and a homeowner appeared associated with reduced victimization while young. The relationship of victimization age and employment was not uniform across racial groups, nor was the relationship of victimization age and marital status uniform across groups. Among Blacks, using mental health services was associated with longer life. Homicide by firearm proved important for our Black and Hispanic subsamples, while among Whites, alcohol's involvement in homicide exerted significant effects. Our results suggest that programs and policies serving the various racial/ethnic groups can alleviate multiple disadvantages relevant in homicide victimization at an early age.

  4. Age is associated with time in therapeutic range for warfarin therapy in patients with atrial fibrillation

    PubMed Central

    da Costa Darrieux, Francisco Carlos; Hachul, Denise Tessariol; Scanavacca, Maurício Ibrahim; Krieger, Jose Eduardo; Pereira, Alexandre Costa; Lima Santos, Paulo Caleb Junior

    2016-01-01

    Background Warfarin is the most prescribed oral anticoagulant used for preventing stroke in patients with atrial fibrillation. Time in the therapeutic range (TTR) has been accepted as the best method to evaluate the quality of warfarin therapy. The main aim of the present study was to evaluate the impact of variables on the time in the therapeutic range for warfarin therapy in patients with atrial fibrillation from a referral cardiovascular hospital. Methods This retrospective study included 443 patients were included (190 patients with age < 65 years and 253 patients with age ≥65 years) from 2011 to 2014 and TTR was computed according to Rosendaal's method. Results Patients with age ≥65 years had higher TTR value (67±22%) compared with patients with < 65 years (60±24%) (p = 0.004). In a linear regression model, only age ≥65 years emerged as a significant predictor of greater TTR values. In multivariate logistic regression model, the variable age ≥65 years was associated with higher OR for having a TTR higher than the median value (OR = 2.17, p < 0.001). Conclusion We suggest that the age influenced TTR through greater drug adherence. Strategies for increasing drug adherence might improve quality of warfarin anticoagulation. PMID:27486984

  5. Unexpected Retirement from Full Time Work after Age 62: Consequences for Life Satisfaction in older Americans

    PubMed Central

    Clarke, Philippa; Marshall, Victor W.; Weir, David

    2013-01-01

    Recent policy shifts in the United States have resulted in an increase in the number of older workers remaining in the labor force. Increases in the retirement age for receiving full Social Security benefits coupled with declining pension funds and the erosion of employer retiree health benefits, mean that current cohorts of older workers may fully expect to work longer than previous generations. Yet, working longer may not always be possible due to health problems, outdated skills, economic insecurity, and competing obligations. We examine the consequences of unmet expectations for full time work after age 62 for life satisfaction in a nationally representative sample of older Americans. With longitudinal data from the Health and Retirement Study (1998–2008), this paper uses repeated measures of expectations for later life work among a cohort of Americans (N=1684) gathered prospectively over an eight year period, and examines the effects of unfulfilled expectations on subsequent life satisfaction. Using generalized growth mixture modeling three latent classes of individuals were identified with distinct trajectories of later life work expectations (low expectations, high expectations, and neutral expectations for full time work after age 62). A majority of men had generally high expectations to work full time past age 62, whereas the majority of women reported a low probability of working full time after age 62. When comparing expectations to actual full time work past age 62, we found no effects of unmet expectations for women. But men with less job stability (reflected by shorter job tenure and lower incomes) generally had high expectations to work longer, and their life satisfaction scores were significantly lower when these expectations were not realized. The hazards of missed expectations for later life work have consequences for subjective well-being in older adults. PMID:24159276

  6. Ar-Ar Impact Heating Ages of Eucrites and Timing of the LHB

    NASA Technical Reports Server (NTRS)

    Bogard, Donald; Garrison, Daniel

    2009-01-01

    Eucrites and howardites, more than most meteorite types, show extensive impact resetting of their Ar-39-Ar-40 (K-Ar) ages approximately equal to 3.4-4.1 Ga ago, and many specimens show some disturbance of other radiometry chronometers as well. Bogard (1995) argued that this age resetting occurred on Vesta and was produced by the same general population of objects that produced many of the lunar impact basins. The exact nature of the lunar late heavy bombardment (LHB or 'cataclysm') remains controversial, but the timing is similar to the reset ages of eucrites. Neither the beginning nor ending time of the lunar LHB is well constrained. Comparison of Ar-Ar ages of brecciated eucrites with data for the lunar LHB can resolve both the origin of these impactors and the time period over which they were delivered to the inner solar system. This abstract reports some new Ar-Ar age data for eucrites, obtained since the authors' 1995 and 2003 papers.

  7. Status of spent-fuel shipping cask development

    SciTech Connect

    Hall, I.K.; Hinschberger, T.S.

    1989-01-01

    The purpose of the Cask Systems Development Program is to develop a variety of cask systems that can safely and economically transport commercial spent fuel and high-level waste from the generating sites to a federal geologic repository or monitored retrievable storage (MRS) facility. This paper is limited to a discussion of the status of from-reactor spent-fuel cask development; future cask development plans include MRS-to-repository casks, specialty casks for nonstandard spent fuel and nonfuel materials, and defense high-level waste casks. Spent-fuel casks must be available in the late 1990s to support the U.S. Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM) shipments from utilities. DOE-Idaho, with the support of EG G Idaho, Inc., Sandia National Laboratories, and selected cask developing contractors, has been assigned the responsibility for developing a new generation of cask systems. Four categories of spent fuel casks were initially proposed: (1) legal weight truck (LWT) casks (2) overweight truck (OWT) casks (3) rail/barge (R/B) casks (4) dual purpose (DP) storage/transport casks. Casks are being designed for reduced occupational radiation exposure at the receiving facility by facilitating the use of remote handling equipment. Automation of remote handling systems may be used to reduce cask turnaround time. Reducing turnaround time promotes reduced radiation exposure to occupational workers and improves cask utilization efficiency.

  8. Language and ageing - exploring propositional density in written language - stability over time.

    PubMed

    Spencer, Elizabeth; Craig, Hugh; Ferguson, Alison; Colyvas, Kim

    2012-09-01

    This study investigated the stability of propositional density (PD) in written texts, as this aspect of language shows promise as an indicator and as a predictor of language decline with ageing. This descriptive longitudinal study analysed written texts obtained from the Australian Longitudinal Study of Women's Health in which participants were invited to respond to an open-ended question about their health. The 635 texts used for this study were taken from 127 middle-aged women who responded to this question on each of the five surveys conducted at 3-year intervals over a 16-year period. The study made use of an automated PD rater (CPIDR-3) for the analysis. PD was found to be a stable measure over time when comparing the grouped data, but there was between- and within-subject variation over time. Further research is needed to explore the valid use of this measure in research into language and ageing.

  9. 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.

  10. HTGR Spent Fuel Treatment Program. HTGR Spent Fuel Treatment Development Program Plan

    SciTech Connect

    Not Available

    1984-12-01

    The spent fuel treatment (SFT) program plan addresses spent fuel volume reduction, packaging, storage, transportation, fuel recovery, and disposal to meet the needs of the HTGR Lead Plant and follow-on plants. In the near term, fuel refabrication will be addressed by following developments in fresh fuel fabrication and will be developed in the long term as decisions on the alternatives dictate. The formulation of this revised program plan considered the implications of the Nuclear Waste Policy Act of 1982 (NWPA) which, for the first time, established a definitive national policy for management and disposal of nuclear wastes. Although the primary intent of the program is to address technical issues, the divergence between commercial and government interests, which arises as a result of certain provisions of the NWPA, must be addressed in the economic assessment of technically feasible alternative paths in the management of spent HTGR fuel and waste. This new SFT program plan also incorporates a significant cooperative research and development program between the United States and the Federal Republic of Germany. The major objective of this international program is to reduce costs by avoiding duplicate efforts.

  11. Changes in multifractality with aging and heart failure in heartbeat interval time series.

    PubMed

    Munoz Diosdado, A; Angulo Brown, F; Del Rio Correa, J L

    2005-01-01

    We present a multifractal analysis of diurnal heart interbeat time series from healthy young subjects, healthy elderly subjects and patients with congestive heart failure (CHF). Aging and CHF causes loss of multifractality. We analyze the multifractal spectrum asymmetry. We show that the joint analysis of the degree of multifractality and the asymmetry parameter can differentiate between the cardiac interbeat time series of young and elderly persons and it can also separate healthy subjects and CHF patients.

  12. Time, clinic technologies, and the making of reflexive longevity: the cultural work of time left in an ageing society.

    PubMed

    Kaufman, Sharon R

    2010-02-01

    Developments in clinical intervention are having a profound impact on health and health behaviours in late life and on ideas about longevity and the appropriate time for death. The fact that the timing of death is even considered to be a controllable event is a relatively new cultural phenomenon. The activities that make up life extension, like other medical practices scrutinised by social scientists, constitute a site for the emergence of new forms of subjectivity. For older adults the clinical encounter forces a calculation about how much time left is wanted in relation to age. The twin dimensions of the transformation of time highlighted in this article - the control over the timing of death and the creation of time left - both contribute to and are a widespread effect of biomedicalisation in affluent sectors of society. Through three stories this paper begins to map the cultural work that the concept, time left, does, the socio-medical ways in which that notion is talked about, organised and calculated in the American clinic today. It asks, what kind of subject emerges when longevity, imbued with the technological, becomes a reflexive practice and an object of intervention and apparent choice?

  13. Age-Related Differences in Reaction Time Task Performance in Young Children

    ERIC Educational Resources Information Center

    Kiselev, Sergey; Espy, Kimberlay Andrews; Sheffield, Tiffany

    2009-01-01

    Performance of reaction time (RT) tasks was investigated in young children and adults to test the hypothesis that age-related differences in processing speed supersede a "global" mechanism and are a function of specific differences in task demands and processing requirements. The sample consisted of 54 4-year-olds, 53 5-year-olds, 59…

  14. Effects of Hearing and Aging on Sentence-Level Time-Gated Word Recognition

    ERIC Educational Resources Information Center

    Molis, Michelle R.; Kampel, Sean D.; McMillan, Garnett P.; Gallun, Frederick J.; Dann, Serena M.; Konrad-Martin, Dawn

    2015-01-01

    Purpose: Aging is known to influence temporal processing, but its relationship to speech perception has not been clearly defined. To examine listeners' use of contextual and phonetic information, the Revised Speech Perception in Noise test (R-SPIN) was used to develop a time-gated word (TGW) task. Method: In Experiment 1, R-SPIN sentence lists…

  15. Factors Associated with Screen Time among School-Age Children in Korea

    ERIC Educational Resources Information Center

    Ham, Ok Kyung; Sung, Kyung Mi; Kim, Hee Kyung

    2013-01-01

    The purpose of this study was to investigate the association of sociodemographic, psychosocial, and behavioral characteristics with screen time among school-age children in Korea. This study employed a nonexperimental, cross-sectional study design. A total of 370 children attending four elementary schools participated in the study. Self-report…

  16. Adult Age Differences in Divergent Thinking: It's Just a Matter of Time

    ERIC Educational Resources Information Center

    Foos, Paul W.; Boone, David

    2008-01-01

    This study examined adult age differences on five tests of divergent thinking: associational fluency, expressional fluency, ideational fluency, word fluency, and consequences. Our hypothesis was that young adults ( M = 20.53, n = 60) would score higher than old adults (M = 72.10, n = 60) under standard timed test conditions, but old adults would…

  17. Effects of Aging and Noise on Real-Time Spoken Word Recognition: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Ben-David, Boaz M.; Chambers, Craig G.; Daneman, Meredyth; Pichora-Fuller, M. Kathleen; Reingold, Eyal M.; Schneider, Bruce A.

    2011-01-01

    Purpose: To use eye tracking to investigate age differences in real-time lexical processing in quiet and in noise in light of the fact that older adults find it more difficult than younger adults to understand conversations in noisy situations. Method: Twenty-four younger and 24 older adults followed spoken instructions referring to depicted…

  18. Mechanical properties of bulk polydimethylsiloxane for microfluidics over a large range of frequencies and aging times

    NASA Astrophysics Data System (ADS)

    Placet, V.; Delobelle, P.

    2015-03-01

    The dynamic mechanical characterization of polydimethylsiloxane (PDMS) over a large range of frequencies (10-2 < f < 105 Hz) and long aging times at room temperature (4 h < tv < ~60 000 h) has been presented. Three samples with different curing conditions have been studied and three different techniques, dynamic mechanical analysis at different temperatures, nano-indentation and scanning micro-deformation microscopy, have been used. Although the three techniques work at different scales and at different frequencies all the results match the same master curve. As expected, the storage and the loss moduli greatly increase with the frequency. Moreover, these moduli moderately increase with the aging time tv depending on the curing temperature. A simple model which takes the frequency and the aging time into account, and which is based on the Havriliak-Negami model, has been presented and identified. Hence, values of the relaxed and instantaneous moduli at tv = 0 and tv = ∞ are proposed. Only the relaxed moduli depend on the curing conditions and moreover it has been shown that the tangent of the phase lag is independent of the aging time and thus of the curing process.

  19. Chronic stroke and aging: the impact of acoustic stimulus intensity on fractionated reaction time.

    PubMed

    Coombes, Stephen A; Janelle, Christopher M; Cauraugh, James H

    2009-03-13

    In control samples, intense acoustic "go" stimuli accelerate the central and peripheral motor processes that compose simple reaction time movements. The goal of the current study was to determine whether movements that are initiated to intense acoustic cues facilitate simple reaction times in (1) adults with chronic stroke as compared to age matched controls and (2) in older as compared to younger adults. EMG and force data were collected from three groups (stroke, older adults, and younger adults) during a ballistic wrist and finger extension task. Movements were made to the onset of 80 dB and 107 dB acoustic cues and simple reaction times were fractionated into premotor and motor components. The present findings offer two important contributions to the literature. First, increases in stimulus intensity led to faster motor times in the impaired limb of stroke subjects. Second, increased stimulus intensity led to faster premotor reaction times across all groups, although an age rather than a stroke-specific motor deficit was evidenced, with the younger control group displaying significantly faster premotor times. Findings are integrated with previous evidence concerning post stroke corticospinal tract integrity and are interpreted via mechanisms which address stroke and age-related changes in motoneurons and activity in motor units.

  20. Condition Monitoring of a Thermally Aged HTPB/IPDI Elastomer by NMR CP Recovery Times

    SciTech Connect

    ASSINK,ROGER A.; LANG,DAVID; CELINA,MATHIAS C.

    2000-07-24

    A hydroxy-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) elastomer is commonly used as propellant binder material. The thermal degradation of the binder is believed to be an important parameter governing the performance of the propellant. The aging of these binders can be monitored by mechanical property measurements such as modulus or tensile elongation. These techniques, however, are not easily adapted to binder agents that are dispersed throughout a propellant. In this paper the authors investigated solid state NMR relaxation times as a means to predict the mechanical properties of the binder as a function of aging time. {sup 1}H spin-lattice and spin-spin relaxation times were found to be insensitive to the degree of thermal degradation of the elastomer. Apparently these relaxation times depend on localized motions that are only weakly correlated with mechanical properties. A strong correlation was found between the {sup 13}C cross-polarization (CP) NMR time constant, T{sub cp}, and the tensile elongation at break of the elastomer as a function of aging time. A ramped-amplitude CP experiment was shown to be less sensitive to imperfections in setting critical instrumental parameters for this mobile material.

  1. Mechanical properties improvement of silica aerogel through aging: Role of solvent type, time and temperature

    NASA Astrophysics Data System (ADS)

    Omranpour, H.; Dourbash, A.; Motahari, S.

    2014-05-01

    Effective parameters that enhance mechanical properties during aging were investigated in the present study. Silica aerogels were made from tetraethyl orthosilicate (TEOS), water, methanol and NH4F in molar ratio 1:4:8:2×10-3 using a one-step method. Different time, temperature and aging solvents in aging stage were studied. Subsequently, solvent exchange with n-hexane, modification under TMCS solution and ambient pressure drying (APD) were performed for all samples. The aerogels had densities within the range of 0.1 and 0.6 g/cm3. The FTIR, mechanical properties, density and BET results, porosity, pore volume, pore diameter and surface area of the samples, were discussed. The compression properties of the gel increased with the increase in the time and temperature of aging. It was observed that solvents with more polarity improved polymerization, which enhanced the mechanical properties of the related samples. However, the stresses and capillary forces of water during drying were so large that inhibited "spring-back effect" during APD, and consequently a collapsed silica network with higher density was fabricated. In other words, the specific compression strength and modulus declined drastically. For methanol, alcohols inhibit the reactions inconveniently causing more shrinkage. In aging by n-hexane, capillary pressure declined significantly and thereby shrinkage was eliminated and silica aerogels with low bulk densities (0.095 g/cm3), high specific surface areas (600 m2/g), and large pore volumes (2.6 cm3/g) were synthesized.

  2. A Statistical Framework to Identify Deviation from Time Linearity in Epigenetic Aging

    PubMed Central

    Snir, Sagi; vonHoldt, Bridgett M.; Pellegrini, Matteo

    2016-01-01

    In multiple studies DNA methylation has proven to be an accurate biomarker of age. To develop these biomarkers, the methylation of multiple CpG sites is typically linearly combined to predict chronological age. By contrast, in this study we apply the Universal PaceMaker (UPM) model to investigate changes in DNA methylation during aging. The UPM was initially developed to study rate acceleration/deceleration in sequence evolution. Rather than identifying which linear combinations of sites predicts age, the UPM models the rates of change of multiple CpG sites, as well as their starting methylation levels, and estimates the age of each individual to optimize the model fit. We refer to the estimated age as the “epigenetic age”, which is in contrast to the known chronological age of each individual. We construct a statistical framework and devise an algorithm to determine whether a genomic pacemaker is in effect (i.e rates of change vary with age). The decision is made by comparing two competing likelihood based models, the molecular clock (MC) and UPM. For the molecular clock model, we use the known chronological age of each individual and fit the methylation rates at multiple sites, and express the problem as a linear least squares and solve it in polynomial time. For the UPM case, the search space is larger as we are fitting both the epigenetic age of each individual as well as the rates for each site, yet we succeed to reduce the problem to the space of individuals and polynomial in the more significant space—the methylated sites. We first tested our algorithm on simulated data to elucidate the factors affecting the identification of the pacemaker model. We find that, provided with enough data, our algorithm is capable of identifying a pacemaker even when a weak signal is present in the data. Based on these results, we applied our method to DNA methylation data from human blood from individuals of various ages. Although the improvement in variance across sites

  3. Effects of Hearing and Aging on Sentence-Level Time-Gated Word Recognition

    PubMed Central

    Molis, Michelle R.; Kampel, Sean D.; McMillan, Garnett P.; Gallun, Frederick J.; Dann, Serena M.; Konrad-Martin, Dawn

    2015-01-01

    Purpose Aging is known to influence temporal processing, but its relationship to speech perception has not been clearly defined. To examine listeners’ use of contextual and phonetic information, the Revised Speech Perception in Noise test (R-SPIN) was used to develop a time-gated word (TGW) task Method In Experiment 1, R-SPIN sentence lists were matched on context, target-word length, and median word segment length necessary for target recognition. In Experiment 2, TGW recognition was assessed in quiet and in noise among adults of various ages with normal hearing to moderate hearing loss. Linear regression models of the minimum word duration necessary for correct identification and identification failure rates were developed. Age and hearing thresholds were modeled as continuous predictors with corrections for correlations among multiple measurements of the same participants. Results While aging and hearing loss both had significant impacts on task performance in the most adverse listening condition (low context, in noise), for most conditions, performance was limited primarily by hearing loss. Conclusion Whereas hearing loss was strongly related to target-word recognition, the effect of aging was only weakly related to task performance. These results have implications for the design and evaluation of studies of hearing and aging. PMID:25815688

  4. Timing Issues with Early Childhood Education Programs: How Effect Sizes Vary by Starting Age, Program Duration and Persistence of Effects

    ERIC Educational Resources Information Center

    Duncan, Greg J.; Leak, James A.; Li, Weilin; Magnuson, Katherine; Schindler, Holly; Yoshikawa, Hiro

    2011-01-01

    The focus of this paper centers around timing associated with early childhood education programs and interventions using meta-analytic methods. At any given assessment age, a child's current age equals starting age, plus duration of program, plus years since program ended. Variability in assessment ages across the studies should enable everyone to…

  5. Screen time and sleep among school-aged children and adolescents: a systematic literature review.

    PubMed

    Hale, Lauren; Guan, Stanford

    2015-06-01

    We systematically examined and updated the scientific literature on the association between screen time (e.g., television, computers, video games, and mobile devices) and sleep outcomes among school-aged children and adolescents. We reviewed 67 studies published from 1999 to early 2014. We found that screen time is adversely associated with sleep outcomes (primarily shortened duration and delayed timing) in 90% of studies. Some of the results varied by type of screen exposure, age of participant, gender, and day of the week. While the evidence regarding the association between screen time and sleep is consistent, we discuss limitations of the current studies: 1) causal association not confirmed; 2) measurement error (of both screen time exposure and sleep measures); 3) limited data on simultaneous use of multiple screens, characteristics and content of screens used. Youth should be advised to limit or reduce screen time exposure, especially before or during bedtime hours to minimize any harmful effects of screen time on sleep and well-being. Future research should better account for the methodological limitations of the extant studies, and seek to better understand the magnitude and mechanisms of the association. These steps will help the development and implementation of policies or interventions related to screen time among youth.

  6. Screen Time and Sleep among School-Aged Children and Adolescents: A Systematic Literature Review

    PubMed Central

    Hale, Lauren; Guan, Stanford

    2015-01-01

    Summary We systematically examined and updated the scientific literature on the association between screen time (e.g., television, computers, video games, and mobile devices) and sleep outcomes among school-aged children and adolescents. We reviewed 67 studies published from 1999 to early 2014. We found that screen time is adversely associated with sleep outcomes (primarily shortened duration and delayed timing) in 90% of studies. Some of the results varied by type of screen exposure, age of participant, gender, and day of the week. While the evidence regarding the association between screen time and sleep is consistent, we discuss limitations of the current studies: 1.) causal association not confirmed; 2.) measurement error (of both screen time exposure and sleep measures); 3.) limited data on simultaneous use of multiple screens, characteristics and content of screens used. Youth should be advised to limit or reduce screen time exposure, especially before or during bedtime hours to minimize any harmful effects of screen time on sleep and well-being. Future research should better account for the methodological limitations of the extant studies, and seek to better understand the magnitude and mechanisms of the association. These steps will help the development and implementation of policies or interventions related to screen time among youth. PMID:25193149

  7. Elastic moduli of δ-Pu 239 reveal aging in real time

    DOE PAGES

    Maiorov, Boris; Betts, Jonathan B.; Söderlind, Per; ...

    2017-03-28

    We study the time evolution (aging) of the elastic moduli of an eight-year-old polycrystalline δ- Pu 2.0 at % Ga alloy (δ-Pu:Ga ) from 295K to nearly 500K in real time using Resonant Ultrasound Spectroscopy (RUS). After 8 years of aging at 295K, the bulk and shear moduli increase at a normalized rate of 0.2%/year and 0.6%/year respectively. As the temperature is raised, two time dependences are observed, an exponential one of about a week, followed by a linear one (constant rate). The linear rate is thermally activated with an activation energy of 0.33+0.06 eV. Above 420K a qualitative changemore » in the time evolution is observed; the bulk modulus decreases with time while the shear modulus continues to stiffen. No change is observed as the α-β transition temperature is crossed as would be expected if a decomposition of δ-Pu:Ga to α-Pu and Pu3Ga occurred over the temperature range studied. Our results indicate that the main mechanism of aging is creation of defects that are partially annealed starting at T = 420 K.« less

  8. Real time compensation of in aging effects in solid-state lighting

    NASA Astrophysics Data System (ADS)

    Cappitelli, M.; Bleicken, J. R.

    2014-09-01

    All available Solid-State Lighting (SSL) systems like LED or OLED suffer from the burden of intrinsic and extrinsic aging effects. These aging effects lead to a degeneration of brightness and color inside the light source, which can be observed far before the failure time (D70). The paper presents a solution for a real time compensation system, which is able to compensate the color and brightness of a lighting system by optical sensing and real time optimization. This approach offers the opportunity to oper ate independently from the implemented light source type and number of primary colors. The benefit is an enhancement in the overall quality and durability of the light source parameters and an elongation of the system use. The solution utilizes a full color sensor and miniaturized embedded computing capabilities to ensure the dedicated performance. Compared to the cost of LED and OLED lighting systems, the overall benefit in quality justifies the additional costs.

  9. Effects of subprimal type, quality grade, and aging time on display color of ground beef patties.

    PubMed

    Garner, C M; Unruh, J A; Hunt, M C; Boyle, E A E; Houser, T A

    2014-10-01

    A factorial design was used to evaluate the effects of two subprimal types (chuck roll and knuckle), two quality grades (Premium Choice and Select), and three vacuum-storage aging times before processing (7, 21, and 42d) ground beef patty display color attributes. Patties from chuck roll and Premium Choice subprimals had brighter red visual color scores, less discoloration, and higher L*, a*, b*, and chroma values than those from knuckle and Select subprimals, respectively. With an increased display time, patties became darker red, more discolored, and had decreased L*, a*, b*, and chroma values. Therefore, aging Premium Choice chuck rolls for less time (fewer than 21d) could maximize display color life.

  10. Nickel hydroxide ageing time influence on its solubility in water acidified with sulphuric acid.

    PubMed

    Osińska, Małgorzata; Stefanowicz, Tadeusz; Paukszta, Dominik

    2004-08-30

    Nickel hydroxide samples freshly settled as well as stored over 1 month, 2 months and 6.5 years were examined for their solubility rate in diluted H2SO4 solutions of pH 1.9 and 2.8 as a function of time. Samples with a longer ageing history dissolved less readily than freshly settled ones. It was determined that the resistance to dissolving rose with sample ageing time and the solubility of the 6.5 years stored sample was particularly low. X-ray examination evidenced that during storage the crystallinity of Ni(OH)2 subsequently rose. The parallelity of both time-dependent phenomena allows the conclusion that with nickel hydroxide ageing the transformation of disordered nickel hydroxide species into crystalline Ni(OH)2 (without phase changes) is responsible for increasing nickel hydroxide resistance to dissolving in acidic solutions. Such decrease of nickel hydroxide solubility with ageing in case of waste nickel hydroxide, is worth to notice in a view of environment protection against pollution with electroplating waste.

  11. Age differences in multiple outcome measures of time-based prospective memory.

    PubMed

    Mäntylä, Timo; Missier, Fabio Del; Nilsson, Lars-Göran

    2009-11-01

    This study examined time-based prospective memory performance in relation to age, monitoring strategy, response accuracy, and dual-task demands. Young, middle-aged and older adults (N = 115) completed a prospective memory task, in which they indicated the passing of time every 5 min while listening to a short story (low task demands) or completing a series of cognitive tasks (high task demands). Young and older adults showed similar patterns of monitoring behavior, with low rates of clock checking during the early phase of each 5-min interval, followed by linearly accelerating monitoring functions. However, to obtain the same level of prospective memory performance older adults needed more frequent clock checks than young adults. Furthermore, older adults' compensatory monitoring strategy was associated with an additional cost in primary task performance. Finally, increased primary task demands shifted age differences in prospective memory from monitoring frequency to response accuracy. These findings suggest that goal-directed behavior requires efficient task coordination and resource allocation, and that age-related differences in time-based prospective memory should be evaluated by using multiple outcome measures.

  12. Separation of actinides from spent nuclear fuel: A review.

    PubMed

    Veliscek-Carolan, Jessica

    2016-11-15

    This review summarises the methods currently available to extract radioactive actinide elements from solutions of spent nuclear fuel. This separation of actinides reduces the hazards associated with spent nuclear fuel, such as its radiotoxicity, volume and the amount of time required for its' radioactivity to return to naturally occurring levels. Separation of actinides from environmental water systems is also briefly discussed. The actinide elements typically found in spent nuclear fuel include uranium, plutonium and the minor actinides (americium, neptunium and curium). Separation methods for uranium and plutonium are reasonably well established. On the other hand separation of the minor actinides from lanthanide fission products also present in spent nuclear fuel is an ongoing challenge and an area of active research. Several separation methods for selective removal of these actinides from spent nuclear fuel will be described. These separation methods include solvent extraction, which is the most commonly used method for radiochemical separations, as well as the less developed but promising use of adsorption and ion-exchange materials.

  13. CASMO-2 spent-fuel-rack criticality analysis

    SciTech Connect

    Napolitano, D.G.; Heinrichs, D.P.; Gorski, J.P.

    1986-01-01

    In recent years, utilities have needed to increase their spent-fuel storage capacity. Both Maine Yankee pressurized water reactor (PWR) and Vermont Yankee boiling water reactor (BWR) have increased their spent-fuel rack capacity by decreasing the canister center-to-center spacing while adding fixed poison. Licensing criticality analysis of such changes in spent-fuel rack design have been performed at Yankee Atomic Electric Co. (YAEC) using NITAWL-KENO-IV and the 123-group XSDRN library. However, KENO/Monte Carlo analysis has inherent drawbacks when applied to spent-fuel rack design and modification. These include statistical uncertainty and long computer time. In contrast, the transport theory code, CASMO-2, provides deterministic and fast criticality analysis. Also, since collapsed and transport-corrected cross sections are generated, PDQ can be used to analyze large array problems which are prohibitively expensive using KENO. In this work, the authors apply the CASMO-PDQ methodology to the Maine Yankee and Vermont Yankee high-density spent-fuel rack designs, and compare the final results against KENO.

  14. Status of work at PNL supporting dry storage of spent fuel

    SciTech Connect

    Cunningham, M.E.; McKinnon, M.A.; Michener, T.E.; Thomas, L.E.; Thornhill, C.K.

    1993-01-01

    This report discusses three projects related to dry storage of light-water reactor spent fuel which are being conducted at Pacific Northwest Laboratory. Performance testing of six dry storage systems (four metal casks and two concrete storage systems) has been completed and results compiled. Two computer codes for predicting spent fuel and storage system thermal performance, COBRA-SFS and HYDRA-II, have been developed and have been reviewed by the US Nuclear Regulatory Commission. Air oxidation testing of spent fuel was conducted from 1984 through 1990 to obtain data to support recommendations of temperature-time limits for air dry storage of spent light-water reactor fuel.

  15. Partial Defect Verification of Spent Fuel Assemblies by PDET: Principle and Field Testing in Interim Spent Fuel Storage Facility (CLAB) in Sweden

    SciTech Connect

    Ham, Y.S.; Kerr, P.; Sitaraman, S.; Swan, R.; Rossa, R.; Liljenfeldt, H.

    2015-07-01

    The need for the development of a credible method and instrument for partial defect verification of spent fuel has been emphasized over a few decades in the safeguards communities as the diverted spent fuel pins can be the source of nuclear terrorism or devices. The need is increasingly more important and even urgent as many countries have started to transfer spent fuel to so called 'difficult-to-access' areas such as dry storage casks, reprocessing or geological repositories. Partial defect verification is required by IAEA before spent fuel is placed into 'difficult-to-access' areas. Earlier, Lawrence Livermore National Laboratory (LLNL) has reported the successful development of a new, credible partial defect verification method for pressurized water reactor (PWR) spent fuel assemblies without use of operator data, and further reported the validation experiments using commercial spent fuel assemblies with some missing fuel pins. The method was found to be robust as the method is relatively invariant to the characteristic variations of spent fuel assemblies such as initial fuel enrichment, cooling time, and burn-up. Since then, the PDET system has been designed and prototyped for 17x17 PWR spent fuel assemblies, complete with data acquisition software and acquisition electronics. In this paper, a summary description of the PDET development followed by results of the first successful field testing using the integrated PDET system and actual spent fuel assemblies performed in a commercial spent fuel storage site, known as Central Interim Spent fuel Storage Facility (CLAB) in Sweden will be presented. In addition to partial defect detection initial studies have determined that the tool can be used to verify the operator declared average burnup of the assembly as well as intra-assembly burnup levels. (authors)

  16. Context-Specific Outdoor Time and Physical Activity among School-Children Across Gender and Age: Using Accelerometers and GPS to Advance Methods

    PubMed Central

    Klinker, Charlotte Demant; Schipperijn, Jasper; Kerr, Jacqueline; Ersbøll, Annette Kjær; Troelsen, Jens

    2014-01-01

    Introduction: Being outdoors has a positive influence on health among children. Evidence in this area is limited and many studies have used self-reported measures. Objective context-specific assessment of physical activity patterns and correlates, such as outdoor time, may progress this field. Aims: To employ novel objective measures to assess age and gender differences in context-specific outdoor weekday behavior patterns among school-children [outdoor time and outdoor moderate to vigorous physical activity (MVPA)] and to investigate associations between context-specific outdoor time and MVPA. Methods: A total of 170 children had at least one weekday of 9 h combined accelerometer and global positioning system data and were included in the analyses. The data were processed using the personal activity and location measurement system (PALMS) and a purpose-built PostgreSQL database resulting in context-specific measures for outdoor time, outdoor MVPA, and overall daily MVPA. In addition, 4 domains (leisure, school, transport, and home) and 11 subdomains (e.g., urban green space and sports facilities) were created and assessed. Multilevel analyses provided results on age and gender differences and the association between outdoor time and MVPA. Results: Girls compared to boys had fewer outdoor minutes (p < 0.05), spent a smaller proportion of their overall daily time outdoors (p < 0.05), had fewer outdoor MVPA minutes during the day (p < 0.001) and in 11 contexts. Children compared to adolescents had more outdoor minutes (p < 0.05). During school and within recess, children compared to adolescents had more outdoor MVPA (p < 0.001) and outdoor time (p < 0.001). A 1-h increase in outdoor time was associated with 9.9 more minutes of MVPA (p < 0.001). Conclusion: A new methodology to assess the context-specific outdoor time and physical activity patterns has been developed and can be expanded to other populations. Different context

  17. Estimating Allele Age and Selection Coefficient from Time-Serial Data

    PubMed Central

    Malaspinas, Anna-Sapfo; Malaspinas, Orestis; Evans, Steven N.; Slatkin, Montgomery

    2012-01-01

    Recent advances in sequencing technologies have made available an ever-increasing amount of ancient genomic data. In particular, it is now possible to target specific single nucleotide polymorphisms in several samples at different time points. Such time-series data are also available in the context of experimental or viral evolution. Time-series data should allow for a more precise inference of population genetic parameters and to test hypotheses about the recent action of natural selection. In this manuscript, we develop a likelihood method to jointly estimate the selection coefficient and the age of an allele from time-serial data. Our method can be used for allele frequencies sampled from a single diallelic locus. The transition probabilities are calculated by approximating the standard diffusion equation of the Wright–Fisher model with a one-step process. We show that our method produces unbiased estimates. The accuracy of the method is tested via simulations. Finally, the utility of the method is illustrated with an application to several loci encoding coat color in horses, a pattern that has previously been linked with domestication. Importantly, given our ability to estimate the age of the allele, it is possible to gain traction on the important problem of distinguishing selection on new mutations from selection on standing variation. In this coat color example for instance, we estimate the age of this allele, which is found to predate domestication. PMID:22851647

  18. Linking Biological and Cognitive Aging: Toward Improving Characterizations of Developmental Time

    PubMed Central

    DeCarlo, Correne A.; Dixon, Roger A.

    2011-01-01

    Objectives. Chronological age is the most frequently employed predictor in life-span developmental research, despite repeated assertions that it is best conceived as a proxy for true mechanistic changes that influence cognition across time. The present investigation explores the potential that selected functional biomarkers may contribute to the more effective conceptual and operational definitions of developmental time. Methods. We used data from the Victoria Longitudinal Study to explore both static and dynamic biological or physiological markers that arguably influence process-specific mechanisms underlying cognitive changes in late life. Multilevel models were fit to test the dynamic coupling between change in theoretically relevant biomarkers (e.g., grip strength, pulmonary function) and change in select cognitive measures (e.g., executive function, episodic and semantic memory). Results. Results showed that, independent of the passage of developmental time (indexed as years in study), significant time-varying covariation was observed linking corresponding declines for select cognitive outcomes and biological markers. Discussion. Our findings support the interpretation that cognitive decline is not due to chronological aging per se but rather reflects multiple causal factors from a broad range of biological and physical health domains that operate along the age continuum. PMID:21743053

  19. Estimating allele age and selection coefficient from time-serial data.

    PubMed

    Malaspinas, Anna-Sapfo; Malaspinas, Orestis; Evans, Steven N; Slatkin, Montgomery

    2012-10-01

    Recent advances in sequencing technologies have made available an ever-increasing amount of ancient genomic data. In particular, it is now possible to target specific single nucleotide polymorphisms in several samples at different time points. Such time-series data are also available in the context of experimental or viral evolution. Time-series data should allow for a more precise inference of population genetic parameters and to test hypotheses about the recent action of natural selection. In this manuscript, we develop a likelihood method to jointly estimate the selection coefficient and the age of an allele from time-serial data. Our method can be used for allele frequencies sampled from a single diallelic locus. The transition probabilities are calculated by approximating the standard diffusion equation of the Wright-Fisher model with a one-step process. We show that our method produces unbiased estimates. The accuracy of the method is tested via simulations. Finally, the utility of the method is illustrated with an application to several loci encoding coat color in horses, a pattern that has previously been linked with domestication. Importantly, given our ability to estimate the age of the allele, it is possible to gain traction on the important problem of distinguishing selection on new mutations from selection on standing variation. In this coat color example for instance, we estimate the age of this allele, which is found to predate domestication.

  20. Transportation accident scenarios for commercial spent fuel

    SciTech Connect

    Wilmot, E L

    1981-02-01

    A spectrum of high severity, low probability, transportation accident scenarios involving commercial spent fuel is presented together with mechanisms, pathways and quantities of material that might be released from spent fuel to the environment. These scenarios are based on conclusions from a workshop, conducted in May 1980 to discuss transportation accident scenarios, in which a group of experts reviewed and critiqued available literature relating to spent fuel behavior and cask response in accidents.

  1. Spent nuclear fuel project design basis capacity study

    SciTech Connect

    Cleveland, K.J.

    1996-09-09

    A parametric study of the Spent Nuclear Fuel Project system capacity is presented. The study was completed using a commercially available software package to develop a summary level model of the major project systems. Alternative configurations, sub-system cycle times, and operating scenarios were tested to identify their impact on total project duration and equipment requirements.

  2. Accelerated failure time models provide a useful statistical framework for aging research.

    PubMed

    Swindell, William R

    2009-03-01

    Survivorship experiments play a central role in aging research and are performed to evaluate whether interventions alter the rate of aging and increase lifespan. The accelerated failure time (AFT) model is seldom used to analyze survivorship data, but offers a potentially useful statistical approach that is based upon the survival curve rather than the hazard function. In this study, AFT models were used to analyze data from 16 survivorship experiments that evaluated the effects of one or more genetic manipulations on mouse lifespan. Most genetic manipulations were found to have a multiplicative effect on survivorship that is independent of age and well-characterized by the AFT model "deceleration factor". AFT model deceleration factors also provided a more intuitive measure of treatment effect than the hazard ratio, and were robust to departures from modeling assumptions. Age-dependent treatment effects, when present, were investigated using quantile regression modeling. These results provide an informative and quantitative summary of survivorship data associated with currently known long-lived mouse models. In addition, from the standpoint of aging research, these statistical approaches have appealing properties and provide valuable tools for the analysis of survivorship data.

  3. Early-age cold conditioning of broilers: effects of timing and temperature.

    PubMed

    Shahir, M H; Dilmagani, S; Tzschentke, B

    2012-01-01

    1. The aim of the present study was to determine the effects of early-age cold conditioning (CC) on performance, ascites mortality, thyroid hormones status and immune response (leucocytes count) of broiler chickens. 2. A total of 336 chicks at 2 and 3 d of age were exposed to 20 or 25°C (for 3 or 6 h) in a 2 × 2 × 2 factorial experiment, while a control group was kept under normal temperature conditions (30°C). Thereafter, both control and cold conditioned birds were reared under standard conditions until 42 d of age. 3. The results showed that performance (weight gain and feed efficiency) was improved by CC at the end of the rearing period. Carcase traits (breast, thigh and abdominal fat percentage) were not affected by different treatments. Heart weight was lower in cold conditioned birds accompanied with lower ascites mortality. Total leucocyte count was higher in CC birds. Higher concentrations of thyroxin (T(4)) were found in plasma of treated groups, while triiodothyronine (T(3)) to T(4) ratio was decreased. 4. In conclusion, it seems that early age CC improves performance and reduces ascites mortality of broilers through altered thyroid hormones metabolism and leucocyte function. According to the results, the best timing for CC of broilers was 20°C for 6 h at the age of 2 d, and no significant benefit was observed by repeated CC.

  4. Time evolution of damage due to environmentally assisted aging in a fiber bundle model

    NASA Astrophysics Data System (ADS)

    Lennartz-Sassinek, S.; Main, I. G.; Danku, Z.; Kun, F.

    2013-09-01

    Damage growth in composite materials is a complex process which is of interest in many fields of science and engineering. We consider this problem in a fiber bundle model where fibers undergo an aging process due to the accumulation of damage driven by the locally acting stress in a chemically active environment. By subjecting the bundle to a constant external load, fibers fail either when the load on them exceeds their individual intrinsic strength or when the accumulated internal damage exceeds a random threshold. We analyze the time evolution of the breaking process under low external loads where aging of fibers dominates. In the mean field limit, we show analytically that the aging system continuously accelerates in a way which can be characterized by an inverse power law of the event rate with a singularity that defines a failure time. The exponent is not universal; it depends on the details of the aging process. For localized load sharing, a more complex damage process emerges which is dominated by distinct spatial regions of the system with different degrees of stress concentration. Analytical calculations revealed that the final acceleration to global failure is preceded by a stationary accumulation of damage. When the disorder is strong, the accelerating phase has the same functional behavior as in the mean field limit. The analytical results are verified by computer simulations.

  5. Breed, slaughter weight and ageing time effects on physico-chemical characteristics of lamb meat.

    PubMed

    Martínez-Cerezo, S; Sañudo, C; Panea, B; Medel, I; Delfa, R; Sierra, I; Beltrán, J A; Cepero, R; Olleta, J L

    2005-02-01

    The effects of breed, slaughter weight and ageing time on the meat quality of the three most important Spanish breeds were considered. Two hundred and twenty-five lambs of Rasa Aragonesa-local meat breed-, Churra-local dairy breed- and Spanish Merino were used. Animals (75 of each breed) were slaughtered at three different live weights (10-12, 20-22 or 30-32 kg), and the meat was aged for 1, 2, 4, 8 or 16 days. The meat pH, colour, amount of haem pigments, intramuscular fat, moisture, hydroxyproline content and sarcomere length were measured at 24 h post-mortem. Meat texture was measured by compression after each ageing time. The pH of the samples ranged from 5.50 to 5.58. Meat colour varied with breed and slaughter weight (P⩽0.01), the M. longissimus thoracis was lighter in the youngest animals and in the Churra breed and redder in Merinos. Intramuscular fat increased and moisture decreased for heavier lambs. Differences in collagen were associated with breed (P⩽0.01); total and insoluble collagen contents were higher in the Churra breed. Sarcomere length was only slightly affected by slaughter weight. Meat from the Churra breed had the highest values at high levels of compression. Suckling lambs (10-12 kg) had greater myofibrillar toughness than heavier lambs and ageing strongly influenced myofibrillar tenderness.

  6. Microscopic Origin of the Logarithmic Time Evolution of Aging Processes in Complex Systems

    NASA Astrophysics Data System (ADS)

    Lomholt, Michael A.; Lizana, Ludvig; Metzler, Ralf; Ambjörnsson, Tobias

    2013-05-01

    There exists compelling experimental evidence in numerous systems for logarithmically slow time evolution, yet its full theoretical understanding remains elusive. We here introduce and study a generic transition process in complex systems, based on nonrenewal, aging waiting times. Each state n of the system follows a local clock initiated at t=0. The random time τ between clock ticks follows the waiting time density ψ(τ). Transitions between states occur only at local clock ticks and are hence triggered by the local forward waiting time, rather than by ψ(τ). For power-law forms ψ(τ)≃τ-1-α (0<α<1) we obtain a logarithmic time evolution of the state number ⟨n(t)⟩≃log⁡(t/t0), while for α>2 the process becomes normal in the sense that ⟨n(t)⟩≃t. In the intermediate range 1<α<2 we find the power-law growth ⟨n(t)⟩≃tα-1. Our model provides a universal description for transition dynamics between aging and nonaging states.

  7. Associations between reaction time measures and white matter hyperintensities in very old age.

    PubMed

    Haynes, Becky I; Bunce, David; Kochan, Nicole A; Wen, Wei; Brodaty, Henry; Sachdev, Perminder S

    2017-02-01

    In old age, a relationship has been reported between intraindividual variability (IIV) in reaction time and white matter integrity as evidenced by white matter hyperintensities (WMH). However, it is unclear how far such associations are due to incipient neurodegenerative pathology in the samples investigated. The present study examined the relationship between IIV and WMH in older individuals (N=526) drawn from the Sydney Memory and Ageing Study. Using a complex reaction time (RT) task, greater IIV and mean-RT were related to a higher WMH burden in the frontal lobe. Critically, significant associations remained having taken future dementia into account suggesting that they were not explained by incipient dementia. Additionally, independent measures of executive function accounted for the association between RT metrics and WHM. The results are consistent with the view that frontally-supported cognitive processes are involved in IIV-WMH relations, and that RT measures are sensitive to compromise in white matter structures in non-demented older individuals.

  8. Hanford`s spent nuclear fuel retrieval: an agressive agenda

    SciTech Connect

    Shen, E.J., Westinghouse Hanford

    1996-12-06

    Starting December 1997, spent nuclear fuel that has been stored in the K Reactor Fuel Storage Basins will be retrieved over a two year period and repackaged for long term dry storage. The aging and sometimes corroding fuel elements will be recovered and processed using log handled tools and teleoperated manipulator technology. The U.S. Department of Energy (DOE) is committed to this urgent schedule because of the environmental threats to the groundwater and nearby the Columbia River.

  9. Characterization plan for Hanford spent nuclear fuel

    SciTech Connect

    Abrefah, J.; Thornton, T.A.; Thomas, L.E.; Berting, F.M.; Marschman, S.C.

    1994-12-01

    Reprocessing of spent nuclear fuel (SNF) at the Hanford Site Plutonium-Uranium Extraction Plant (PUREX) was terminated in 1972. Since that time a significant quantity of N Reactor and Single-Pass Reactor SNF has been stored in the 100 Area K-East (KE) and K-West (KW) reactor basins. Approximately 80% of all US Department of Energy (DOE)-owned SNF resides at Hanford, the largest portion of which is in the water-filled KE and KW reactor basins. The basins were not designed for long-term storage of the SNF and it has become a priority to move the SNF to a more suitable location. As part of the project plan, SNF inventories will be chemically and physically characterized to provide information that will be used to resolve safety and technical issues for development of an environmentally benign and efficient extended interim storage and final disposition strategy for this defense production-reactor SNF.

  10. Storage assembly for spent nuclear fuel

    SciTech Connect

    Lapides, M.E.

    1982-04-27

    A technique for storing spent fuel rods from a nuclear reactor is disclosed herein. This technique utilizes a housing including a closed inner chamber for containing the fuel rods and a thermally conductive member located partially within the housing chamber and partially outside the housing for transferring heat generated by the fuel rods from the chamber to the ambient surroundings. Particulate material is located within the chamber and surrounds the fuel rods contained therein. This material is selected to serve as a heat transfer media between the contained cells and the heat transferring member and, at the same time, stand ready to fuse into a solid mass around the contained cells if the heat transferring member malfunctions or otherwise fails to transfer the generated heat out of the housing chamber in a predetermined way.

  11. Mixing times towards demographic equilibrium in insect populations with temperature variable age structures.

    PubMed

    Damos, Petros

    2015-08-01

    In this study, we use entropy related mixing rate modules to measure the effects of temperature on insect population stability and demographic breakdown. The uncertainty in the age of the mother of a randomly chosen newborn, and how it is moved after a finite act of time steps, is modeled using a stochastic transformation of the Leslie matrix. Age classes are represented as a cycle graph and its transitions towards the stable age distribution are brought forth as an exact Markov chain. The dynamics of divergence, from a non equilibrium state towards equilibrium, are evaluated using the Kolmogorov-Sinai entropy. Moreover, Kullback-Leibler distance is applied as information-theoretic measure to estimate exact mixing times of age transitions probabilities towards equilibrium. Using empirically data, we show that on the initial conditions and simulated projection's trough time, that population entropy can effectively be applied to detect demographic variability towards equilibrium under different temperature conditions. Changes in entropy are correlated with the fluctuations of the insect population decay rates (i.e. demographic stability towards equilibrium). Moreover, shorter mixing times are directly linked to lower entropy rates and vice versa. This may be linked to the properties of the insect model system, which in contrast to warm blooded animals has the ability to greatly change its metabolic and demographic rates. Moreover, population entropy and the related distance measures that are applied, provide a means to measure these rates. The current results and model projections provide clear biological evidence why dynamic population entropy may be useful to measure population stability.

  12. Effect of spent craft brewers’ yeast on fermentation and methane production by rumen microorganisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saccharomyces cerevisiae is a key component of beer brewing and a major by-product. The leftover, spent brewers’ yeast, from large breweries has been used for some time as a protein supplement in cattle, however the possible advantages of spent yeast from smaller craft breweries, containing much hig...

  13. The timing of fault motion in Death Valley from Illite Age Analysis of fault gouge

    NASA Astrophysics Data System (ADS)

    Lynch, E. A.; Haines, S. H.; Van der Pluijm, B.

    2014-12-01

    We constrained the timing of fluid circulation and associated fault motion in the Death Valley region of the US Basin and Range Province from Illite Age Analysis (IAA) of fault gouge at seven Low-Angle Normal Fault (LANF) exposures in the Black Mountains and Panamint Mountains, and in two nearby areas. 40Ar/39Ar ages of neoformed, illitic clay minerals in these fault zones range from 2.8 Ma to 18.6 Ma, preserving asynchronous fault motion across the region that corresponds to an evolving history of crustal block movements during Neogene extensional deformation. From north to south, along the western side of the Panamint Range, the Mosaic Canyon fault yields an authigenic illite age of 16.9±2.9 Ma, the Emigrant fault has ages of less than 10-12 Ma at Tucki Mountain and Wildrose Canyon, and an age of 3.6±0.17 Ma was obtained for the Panamint Front Range LANF at South Park Canyon. Across Death Valley, along the western side of the Black Mountains, Ar ages of clay minerals are 3.2±3.9 Ma, 12.2±0.13 Ma and 2.8±0.45 Ma for the Amargosa Detachment, the Gregory Peak Fault and the Mormon Point Turtleback detachment, respectively. Complementary analysis of the δH composition of neoformed clays shows a primarily meteoric source for the mineralizing fluids in these LANF zones. The ages fall into two geologic timespans, reflecting activity pulses in the Middle Miocene and in the Upper Pliocene. Activity on both of the range front LANFs does not appear to be localized on any single portion of these fault systems. Middle Miocene fault rock ages of neoformed clays were also obtained in the Ruby Mountains (10.5±1.2 Ma) to the north of the Death Valley region and to the south in the Whipple Mountains (14.3±0.19 Ma). The presence of similar, bracketed times of activity indicate that LANFs in the Death Valley region were tectonically linked, while isotopic signatures indicate that faulting pulses involved surface fluid penetration.

  14. Gestational Age and Autism Spectrum Disorder: Trends in Risk Over Time.

    PubMed

    Atladóttir, H Ó; Schendel, D E; Henriksen, T B; Hjort, L; Parner, E T

    2016-02-01

    Autism Spectrum Disorder (ASD) is a serious neurodevelopmental disorder. Several previous studies have identified preterm birth as a risk factor for ASD but none has studied whether the association between gestational age and ASD has changed over time. This is a Danish population-based follow-up study including live-born singletons born in Denmark between 1980 and 2009, identified in the Danish Medical Birth Registry, a study population of 1,775,397 children. We used a Cox regression model combined with spline to study the risk for ASD by gestational age across three decades of birth cohorts. We included 19,020 children diagnosed with ASD. Across all birth year cohorts, we found that the risk of being diagnosed with ASD increased with lower gestational age (P-value: <0.01). Across all gestational weeks, we found a statistically significant higher risk estimates in birth cohort 1980 to 1989, compared to birth cohorts 1990 to 1999 and 2000 to 2009, respectively. No statistically significant difference in risk estimates was observed between birth cohort 1990 to 1999 and 2000 to 2009. The observed time trend in risk of ASD after preterm birth may reflect: (1) a change in the risk profile of persons with ASD due to the broadening of ASD diagnostic criteria over time; or (2) improved neonatal care for low GA infants, which has reduced risk of adverse outcomes like ASD in preterm children.

  15. Bedtime and evening light exposure influence circadian timing in preschool-age children: A field study

    PubMed Central

    Akacem, Lameese D.; Wright, Kenneth P.; LeBourgeois, Monique K.

    2016-01-01

    Light exposure and sleep timing are two factors that influence inter-individual variability in the timing of the human circadian clock. The aim of this study was to quantify the degree to which evening light exposure predicts variance in circadian timing over and above bedtime alone in preschool children. Participants were 21 children ages 4.5–5.0 years (4.7 ± 0.2 years; 9 females). Children followed their typical sleep schedules for 4 days during which time they wore a wrist actigraph to assess sleep timing and a pendant light meter to measure minute-by-minute illuminance levels in lux. On the 5th day, children participated in an in-home dim-light melatonin onset (DLMO) assessment. Light exposure in the 2 h before bedtime was averaged and aggregated across the 4 nights preceding the DLMO assessment. Mean DLMO and bedtime were 19:22 ± 01:04 and 20:07 ± 00:46, respectively. Average evening light exposure was 710.1 ± 1418.2 lux. Children with later bedtimes (lights-off time) had more delayed melatonin onset times (r=0.61, p=0.002). Evening light exposure was not independently associated with DLMO (r=0.32, p=0.08); however, a partial correlation between evening light exposure and DLMO when controlling for bedtime yielded a positive correlation (r=0.46, p=0.02). Bedtime explained 37.3% of the variance in the timing of DLMO, and evening light exposure accounted for an additional 13.3% of the variance. These findings represent an important step in understanding factors that influence circadian phase in preschool-age children and have implications for understanding a modifiable pathway that may underlie late sleep timing and the development of evening settling problems in early childhood. PMID:28042611

  16. Evaluation of screen time activities and their relationship with physical activity, overweight and socioeconomic status in children 10-12 years of age in Sanandaj, Iran: A cross-sectional study in 2015.

    PubMed

    Moradi, Ghobad; Mostafavi, Farideh; Azadi, Namamali; Esmaeilnasab, Nader; Nouri, Bijan

    2016-01-01

    Background: Screen time (ST), including watching television and playing electronic games are the leading cause of a growing obesity epidemic. This study aimed to evaluate ST and its association with physical activity, overweight and socioeconomic status (SES) in children 10 to 12 years of age in Sanandaj. Methods: This study was designed as a cross-sectional study, which was conducted in Sanandaj in 2015. ST and physical activity data were collected using the Modifiable Activity Questionnaire (MAQ). Overweight indices are defined based on BMI age- and gender-specific percentiles, as proposed by WHO criteria. Considering household assets data, SES was calculated using principal component analysis (PCA). The relationship between ST and different determinants was assessed using logistic regression analysis. Results: Based on the results obtained in our study, 47.28% (95% CI: 45.33-49.24) of the participants spent more than two hours a day on television and video watching and electronic games playing. People who spend greater time on ST activities, independent of their physical activities, are more susceptible to overweight and obesity (p=0.002). People in higher socioeconomic groups spent more time on watching TV and video and playing electronic games (p=0.001). There was a direct relationship between the residential area and ST (P=0.052). ST in male was found to be greater (p=0.033). In addition, ST was also lower in school-aged children whose mothers had a greater education (p=0.56). Conclusion: Based on the results of this study, it is recommended to increase the education level and knowledge of mothers and design interventions consistent with children gender and residential location so that to reduce ST and its associated outcomes in children.

  17. Evaluation of screen time activities and their relationship with physical activity, overweight and socioeconomic status in children 10-12 years of age in Sanandaj, Iran: A cross-sectional study in 2015

    PubMed Central

    Moradi, Ghobad; Mostafavi, Farideh; Azadi, Namamali; Esmaeilnasab, Nader; Nouri, Bijan

    2016-01-01

    Background: Screen time (ST), including watching television and playing electronic games are the leading cause of a growing obesity epidemic. This study aimed to evaluate ST and its association with physical activity, overweight and socioeconomic status (SES) in children 10 to 12 years of age in Sanandaj. Methods: This study was designed as a cross-sectional study, which was conducted in Sanandaj in 2015. ST and physical activity data were collected using the Modifiable Activity Questionnaire (MAQ). Overweight indices are defined based on BMI age- and gender-specific percentiles, as proposed by WHO criteria. Considering household assets data, SES was calculated using principal component analysis (PCA). The relationship between ST and different determinants was assessed using logistic regression analysis. Results: Based on the results obtained in our study, 47.28% (95% CI: 45.33-49.24) of the participants spent more than two hours a day on television and video watching and electronic games playing. People who spend greater time on ST activities, independent of their physical activities, are more susceptible to overweight and obesity (p=0.002). People in higher socioeconomic groups spent more time on watching TV and video and playing electronic games (p=0.001). There was a direct relationship between the residential area and ST (P=0.052). ST in male was found to be greater (p=0.033). In addition, ST was also lower in school-aged children whose mothers had a greater education (p=0.56). Conclusion: Based on the results of this study, it is recommended to increase the education level and knowledge of mothers and design interventions consistent with children gender and residential location so that to reduce ST and its associated outcomes in children. PMID:28210613

  18. Pubertal timing and bone phenotype in early old age: findings from a British birth cohort study

    PubMed Central

    Kuh, Diana; Muthuri, Stella G; Moore, Adam; Cole, Tim J; Adams, Judith E; Cooper, Cyrus; Hardy, Rebecca; Ward, Kate A

    2016-01-01

    Objectives To investigate the effect of pubertal timing, assessed in adolescence, on bone size, strength and density in men and women in early old age Design A British birth cohort study with prospective indicators of pubertal timing based on age at menarche, clinical assessment of pubertal stage, and growth tempo from serial height measures, and bone measures derived from peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) at 60-64 years on 866 women and 792 men. Methods A first set of regression models investigated the relationships between pubertal timing and bone size, strength and density, adjusting for current height and weight, smoking and adult socioeconomic position. To make an equivalent comparison between men and women, the percentage difference in bone outcomes was calculated for a five-year difference in age at menarche, and in men a comparison between those who were fully mature or pre-adolescent at 14.5 years. A second set of models investigated the percentage difference in bone outcomes for a 5-year difference in timing of peak height velocity (height tempo) derived from longitudinal growth modelling (SITAR). Results After adjustment for current height and weight, a 5-year increase in age at menarche was associated with an 8% (95% CI -17%, 0.5%, p=0.07) lower trabecular volumetric bone mineral density (vBMD); men who were pre-adolescent at 14.5 years had a 9%, (95%CI -14%,-4%; p=.001) lower trabecular vBMD compared with those who had been fully mature. Other confounders did not attenuate these estimates further. Patterns of association were similar but somewhat weaker for lumbar spine and total hip areal BMD. Age at peak height velocity was associated with even larger differences in BMD in men and women, and was negatively associated with bone size and strength. Conclusions The association between later puberty and lower BMD persists into early old age. The 9-10% lower trabecular vBMD in later compared with

  19. Age at Time of Initial Sexual Intercourse and Health of Adolescent Girls.

    PubMed

    Lara, Lúcia A S; Abdo, Carmita H N

    2016-10-01

    Adolescence is characterized by marked changes in the body, psychology, and sexual behavior due to increasing production of hormones. In this review we aimed to assess the effect of age at the time of first sexual intercourse (sexarche) on the health of adolescent girls, and identify factors that might protect against early initiation of sexual relations in girls. The PubMed, Lilacs, and Google Scholar databases were searched for clinical trials, comparative studies, case-control studies, cross-sectional studies, cohort studies, multicenter studies, observational studies, meta-analyses, and systematic reviews published up to December 2014 on this theme. The search terms were: "sexual debut," "coitarche," "sexarche," and "young people," "adolescent," "unplanned pregnancy," "adolescent contraception," and "STDs." Data were extracted from 28 studies and 41 references were used to introduce the theme and to support the discussion. Sexarche has been occurring in increasingly younger girls. A young age at sexarche can lead to subsequent risky sexual behavior. Girls who have sexarche when they are 14 years old or younger are less likely to use contraception on this occasion, take more time before they start using contraception in subsequent sexual relations, are more likely to have several sex partners, have a higher risk for depression, have lower self-esteem and more episodes of repentance, and have a higher risk for a sexually transmitted disease and cervical cancer. Girls with low educational, socioeconomic, and cultural status, little parental monitoring, parental separation, and absence of religiosity tend to experience sexarche at a younger age. Adolescent girls who postpone sexarche until they are 16 years old are physically and psychologically healthier than those who have sexarche at a younger age. This suggests that providing adolescent girls with appropriate education about sexual relations might reduce the negative effect of sexual relations at a young age.

  20. Systems for the Intermodal Routing of Spent Nuclear Fuel

    SciTech Connect

    Peterson, Steven K; Liu, Cheng

    2015-01-01

    The safe and secure movement of spent nuclear fuel from shutdown and active reactor facilities to intermediate or long term storage sites may, in some instances, require the use of several modes of transportation to accomplish the move. To that end, a fully operable multi-modal routing system is being developed within Oak Ridge National Laboratory s (ORNL) WebTRAGIS (Transportation Routing Analysis Geographic Information System). This study aims to provide an overview of multi-modal routing, the existing state of the TRAGIS networks, the source data needs, and the requirements for developing structural relationships between various modes to create a suitable system for modeling the transport of spent nuclear fuel via a multimodal network. Modern transportation systems are comprised of interconnected, yet separate, modal networks. Efficient transportation networks rely upon the smooth transfer of cargoes at junction points that serve as connectors between modes. A key logistical impediment to the shipment of spent nuclear fuel is the absence of identified or designated transfer locations between transport modes. Understanding the potential network impacts on intermodal transportation of spent nuclear fuel is vital for planning transportation routes from origin to destination. By identifying key locations where modes intersect, routing decisions can be made to prioritize cost savings, optimize transport times and minimize potential risks to the population and environment. In order to facilitate such a process, ORNL began the development of a base intermodal network and associated routing code. The network was developed using previous intermodal networks and information from publicly available data sources to construct a database of potential intermodal transfer locations with likely capability to handle spent nuclear fuel casks. The coding development focused on modifying the existing WebTRAGIS routing code to accommodate intermodal transfers and the selection of

  1. Effects of age, available response time and gender on ability to stop suddenly when walking.

    PubMed

    Cao; A Ashton-Miller J; Schultz; Alexander

    1998-10-01

    Background: Injuries may occur during walking when a sudden stop to avoid a gait path obstacle is called for unexpectedly, but cannot be completed in the time available. Little is known about abilities, particularly those of older adults, to stop suddenly. Methods: Twenty young (mean age 23.4 years) and 20 older (72.6 years) healthy and physically active adults with equal numbers of females and males in each age group were studied. While walking straight ahead at approximately 1.3 m/s, they were cued by a light at one of five possible locations to stop as quickly as possible. Subjects were given available response times (ART), the times between the visual cue to stop and potential passage through a virtual wall that was outlined by the array of lights used to cue the subjects, ranging from 375 to 825 ms in 75-ms increments. The rate of success (RS) in completing the stops as prescribed was determined and the effects on RS of age, available response time and gender were examined. Regression analyses were used to interpolate the RS data. Results: At all ART, older female (OF) subjects had a significantly lower rate of success (RS) than either older male (OM) or young adult (YA) subjects. At an ART of 525 ms, for example, RS was 58% for YA and 51% for OM, but only 23% for OF. The regression analyses suggested that OM in the mean would have needed 10 ms longer and OF 70 ms longer than YA to achieve a 50% RS. No significant gender difference in RS were found among YA. Conclusions: The healthy and physically active older female subjects in this study needed longer available response times, and thus longer available stopping distances, than did the young adults or the older males to succeed as well in stopping suddenly while walking at their comfortable gait speed. Copyright 1998 Elsevier Science B.V.

  2. The effect of ageing on multisensory integration for the control of movement timing.

    PubMed

    Elliott, Mark T; Wing, Alan M; Welchman, Andrew E

    2011-09-01

    Previously, it has been shown that synchronising actions with periodic pacing stimuli are unaffected by ageing. However, synchronisation often requires combining evidence across multiple sources of timing information. We have previously shown the brain integrates multisensory cues to achieve a best estimate of the events in time and subsequently reduces variability in synchronised movements (Elliott et al. in Eur J Neurosci 31(10):1828-1835, 2010). Yet, it is unclear if sensory integration of temporal cues in older adults is degraded and whether this leads to reduced synchronisation performance. Here, we test for age-related changes when synchronising actions to multisensory temporal cues. We compared synchronisation performance between young (N = 15, aged 18-37 years) and older adults (N = 15, aged 63-80 years) using a finger-tapping task to auditory and tactile metronomes presented unimodally and bimodally. We added temporal jitter to the auditory metronome to determine whether participants would integrate auditory and tactile signals, with reduced weighting of the auditory metronome as its reliability decreased under bimodal conditions. We found that older adults matched the performance of young adults when synchronising to an isochronous auditory or tactile metronome. When the temporal regularity of the auditory metronome was reduced, older adults' performance was degraded to a greater extent than the young adults in both unimodal and bimodal conditions. However, proportionally both groups showed similar improvements in synchronisation performance in bimodal conditions compared with the equivalent, auditory-only conditions. We conclude that while older adults become more variable in synchronising to less regular beats, they do not show any deficit in the integration of multisensory temporal cues, suggesting that using multisensory information may help mitigate any deficits in coordinating actions to complex timing cues.

  3. Intraindividual Variability in Basic Reaction Time Predicts Middle-Aged and Older Pilots’ Flight Simulator Performance

    PubMed Central

    2013-01-01

    Objectives. Intraindividual variability (IIV) is negatively associated with cognitive test performance and is positively associated with age and some neurological disorders. We aimed to extend these findings to a real-world task, flight simulator performance. We hypothesized that IIV predicts poorer initial flight performance and increased rate of decline in performance among middle-aged and older pilots. Method. Two-hundred and thirty-six pilots (40–69 years) completed annual assessments comprising a cognitive battery and two 75-min simulated flights in a flight simulator. Basic and complex IIV composite variables were created from measures of basic reaction time and shifting and divided attention tasks. Flight simulator performance was characterized by an overall summary score and scores on communication, emergencies, approach, and traffic avoidance components. Results. Although basic IIV did not predict rate of decline in flight performance, it had a negative association with initial performance for most flight measures. After taking into account processing speed, basic IIV explained an additional 8%–12% of the negative age effect on initial flight performance. Discussion. IIV plays an important role in real-world tasks and is another aspect of cognition that underlies age-related differences in cognitive performance. PMID:23052365

  4. Breed, slaughter weight and ageing time effects on sensory characteristics of lamb.

    PubMed

    Martínez-Cerezo, S; Sañudo, C; Medel, I; Olleta, J L

    2005-03-01

    The longissimus lumborum (right and left) from 180 entire male lambs were tasted by a nine-member trained taste panel. The samples were from lambs from three Spanish breeds; Rasa Aragonesa (local meat breed), Churra (local dairy breed) and Spanish Merino. Within breed, three slaughter live weights were considered (10-12, 20-22 or 30-32 kg) and meat was aged in a vacuum package for 1, 2, 4, 8 or 16 days. Panellists assessed a total of eight descriptors. Lamb odour and lamb flavour intensities increased with slaughter weight. However, fat flavour intensity was significantly influenced by breed, with the highest score for Rasa Aragonesa. Off-flavour intensity was influenced by breed and ageing, with higher scores for Rasa Aragonesa and longer ageing times. Tenderness and juiciness were influenced by all three effects (P⩽0.001, each) and there was a significant interaction between breed and slaughter live weight. Meat was juicier and more tender in the lightest Churra lambs, and in the Spanish Merino lambs for the heavier weight animals. Tenderness and juiciness increased with ageing. The best quality flavour was for the Spanish Merino and the intermediate and heavier lambs.

  5. The limits of a limited future time perspective in explaining age differences in emotional functioning.

    PubMed

    Grühn, Daniel; Sharifian, Neika; Chu, Qiao

    2016-09-01

    Although a limited future time perspective (FTP) has been theorized to be the underlying mechanism of positive emotional functioning later in life, there is scant empirical evidence for this position. Using an integrative data-analytic approach, we investigated the predictive value of FTP, age, and subjective health in explaining emotional functioning in a sample of 2,504 adults (17 to 87 years, M = 35.5, SD = 14.2). Although older adults reported a more limited FTP than younger adults, age and a limited FTP had opposite effects in predicting subjective well-being, affect, positive emotions, empathy, and attitudes toward emotions. That is, old age was linked to a more adaptive emotional profile, whereas a limited FTP was linked to a more maladaptive emotional profile. This was the case even after controlling for health-related aspects. The findings question the usage of FTP as an explanatory variable for observed age differences in emotional functioning. (PsycINFO Database Record

  6. Wake Up Time, Light, and Mood in a Population Sample Age 40-64 Years

    PubMed Central

    Endo, Takuro; Ancoli-Israel, Sonia

    2015-01-01

    Objective Concern that disturbances of sleep and light exposures at night might increase cancer risks have been expressed, but little actual exposure data has been collected. Measurements from a representative population sample were examined to understand the magnitude of in-bed light exposure at night and possible correlates. Methods From 1990 to 1994, a home survey of sleep disorders among adults ages 40-64 was conducted in the City of San Diego California, using stratified representative sampling techniques. Along with questionnaires, sleep logs, and 3-night wrist activity and pulse oximetry measures, bedside illumination was measured with a computer recording system. Questionnaires included the CESD depression scale and a scale of symptoms typical of winter depression. Results Complete data were available from 286 men and women, whose mean in-bed intervals averaged 7 hours and 42 minutes. The mean room illumination during the first part of the night was mean 12.7 lux (median 3.2 lux) and during the last 2 hours in bed averaged 28.7 lux (median 18.9 lux). Nocturnal light exposure was positively correlated with age, male gender, summer season, time in bed, wake-up time, and depressive symptoms. Conclusion Complex bi-directional interactions may take place between sleep disturbances, depression, time in bed, wake-up-time, and in-bed illumination. The most crucial light exposures appear to occur in the last 2 hours in bed, largely after dawn, so daylight exposure may be an important factor. PMID:25866517

  7. Links Between Education and Age at Marriage among Palestinian Women in Israel: Changes Over Time.

    PubMed

    Sabbah-Karkaby, Maha; Stier, Haya

    2017-03-01

    This study focuses on the link between education and marriage timing among Israeli-Palestinian women. Theoretical discussions on marriage timing center on the effect of the time women spend in educational institutions on their age at marriage, and on the change in the desirable traits of women in the marriage market. But most of these arguments overlook situations where significant changes in education take place alongside retention of traditional patriarchal values. Based on data from three population censuses - in 1983, 1995 and 2008-our results suggest that staying longer in schooling delays marriage, so women with less education are more likely to marry earlier than others. While young age is still considered an important characteristic in the Israeli-Palestinian marriage market, and women who delay marriage face a greater risk of remaining single, education becomes more important over the years so that postponing marriage becomes especially problematic for low-educated women. Our findings suggest that traditional norms and structural conditions together shape marriage timing.

  8. Slow Desorption of Phenanthrene from Silica Particles: Influence of Pore Size, Pore Water, and Aging Time

    SciTech Connect

    Huesemann, Michael H.; Fortman, Timothy J.; Riley, Robert G.; Thompson, Christopher J.; Wang, Zheming; Truex, Michael J.; Peyton, Brent M.

    2006-01-16

    When micro-porous and meso-porous silica particles were exposed to aqueous phenanthrene solutions for various durations it was observed that sorbed-phase phenanthrene concentrations increased with aging time only for meso-porous but not micro-porous silicas. Desorption equilibrium was reached almost instantaneously for the micro-porous particles while both the rate and extent of desorption decreased with increasing aging time for the meso-porous silicas. These findings indicate that phenanthrene can be sequestered within the internal pore-space of meso-porous silicas while the internal surfaces of micro-porous silicas are not accessible to phenanthrene sorption, possibly due to the presence of physi- or chemi-sorbed water that may sterically hinder the diffusion of phenanthrene inside water-filled micro-pores. By contrast, the internal surfaces of these micro-porous silicas are accessible to phenanthrene when aging methods are employed which assure that pores are devoid of physi-sorbed water. Consequently, when phenanthrene was incorporated into these particles using either supercritical CO2 or via solvent soaking, the aqueous desorption kinetics were extremely slow indicating effective sequestration of phenanthrene inside micro-porous particles. Finally, a two-compartment conceptual model is used to interpret the experimental findings.

  9. Interactive vs passive screen time and nighttime sleep duration among school-aged children

    PubMed Central

    Yland, Jennifer; Guan, Stanford; Emanuele, Erin; Hale, Lauren

    2016-01-01

    Background Insufficient sleep among school-aged children is a growing concern, as numerous studies have shown that chronic short sleep duration increases the risk of poor academic performance and specific adverse health outcomes. We examined the association between weekday nighttime sleep duration and 3 types of screen exposure: television, computer use, and video gaming. Methods We used age 9 data from an ethnically diverse national birth cohort study, the Fragile Families and Child Wellbeing Study, to assess the association between screen time and sleep duration among 9-year-olds, using screen time data reported by both the child (n = 3269) and by the child's primary caregiver (n= 2770). Results Within the child-reported models, children who watched more than 2 hours of television per day had shorter sleep duration by approximately 11 minutes per night compared to those who watched less than 2 hours of television (β = −0.18; P < .001). Using the caregiver-reported models, both television and computer use were associated with reduced sleep duration. For both child- and parent-reported screen time measures, we did not find statistically significant differences in effect size across various types of screen time. Conclusions Screen time from televisions and computers is associated with reduced sleep duration among 9-year-olds, using 2 sources of estimates of screen time exposure (child and parent reports). No specific type or use of screen time resulted in significantly shorter sleep duration than another, suggesting that caution should be advised against excessive use of all screens. PMID:27540566

  10. Methodology for determining criteria for storing spent fuel in air

    SciTech Connect

    Reid, C.R.; Gilbert, E.R.

    1986-11-01

    Dry storage in an air atmosphere is a method being considered for spent light water reactor (LWR) fuel as an alternative to storage in an inert gas environment. However, methods to predict fuel integrity based on oxidation behavior of the fuel first must be evaluated. The linear cumulative damage method has been proposed as a technique for defining storage criteria. Analysis of limited nonconstant temperature data on nonirradiated fuel samples indicates that this approach yields conservative results for a strictly decreasing-temperature history. On the other hand, the description of damage accumulation in terms of remaining life concepts provides a more general framework for making predictions of failure. Accordingly, a methodology for adapting remaining life concepts to UO/sub 2/ oxidation has been developed at Pacific Northwest Laboratory. Both the linear cumulative damage and the remaining life methods were used to predict oxidation results for spent fuel in which the temperature was decreased with time to simulate the temperature history in a dry storage cask. The numerical input to the methods was based on oxidation data generated with nonirradiated UO/sub 2/ pellets. The calculated maximum allowable storage temperatures are strongly dependent on the temperature-time profile and emphasize the conservatism inherent in the linear cumulative damage model. Additional nonconstant temperature data for spent fuel are needed to both validate the proposed methods and to predict temperatures applicable to actual spent fuel storage.

  11. Physical Activity of Preschool-Aged Latino Children in Farmworker Families

    PubMed Central

    Grzywacz, Joseph G.; Suerken, Cynthia K.; Zapata Roblyer, Martha I.; Trejo, Grisel; Arcury, Thomas A.; Ip, Edward H.; Lang, Wei; Quandt, Sara A.

    2014-01-01

    Objective To describe time spent in sedentary and moderate-to-vigorous physical activity (MVPA) by children in Latino farmworker families; and delineate sources of variation in sedentary and MVPA. Method Data were from mother-child dyads (N = 248) in Latino farmworker households in North Carolina. Physical activity was assessed using accelerometers; mothers described their children’s characteristics and their physical and social environments. Results Children spent 6.2 hours/day sedentary (Median=369 minutes), and 6.0 minutes/day in MVPA. Children in Head Start spent more time sedentary, whereas children living where dogs roam freely were less sedentary. Children whose mothers limited screen time spent 2 more minutes in MVPA. Conclusions Preschool-aged Latino children in farmworker families are sedentary, engaging in very little MVPA. PMID:24933141

  12. Modelling the Effects of Ageing Time of Starch on the Enzymatic Activity of Three Amylolytic Enzymes

    PubMed Central

    Guerra, Nelson P.; Pastrana Castro, Lorenzo

    2012-01-01

    The effect of increasing ageing time (t) of starch on the activity of three amylolytic enzymes (Termamyl, San Super, and BAN) was investigated. Although all the enzymatic reactions follow michaelian kinetics, vmax decreased significantly (P < 0.05) and KM increased (although not always significantly) with the increase in t. The conformational changes produced in the starch chains as a consequence of the ageing seemed to affect negatively the diffusivity of the starch to the active site of the enzymes and the release of the reaction products to the medium. A similar effect was observed when the enzymatic reactions were carried out with unaged starches supplemented with different concentrations of gelatine [G]. The inhibition in the amylolytic activities was best mathematically described by using three modified forms of the Michaelis-Menten model, which included a term to consider, respectively, the linear, exponential, and hyperbolic inhibitory effects of t and [G]. PMID:22666116

  13. Survival analysis of timing of first marriage among women of reproductive age in Nigeria: regional differences.

    PubMed

    Adebowale, Stephen A; Fagbamigbe, Francis A; Okareh, Titus O; Lawal, Ganiyu O

    2012-12-01

    Early marriage is common among women in developing countries. Age at first marriage (AFM) has health implication on women and their under-five children. In Nigeria, few studies have explored AFM; the current study was designed to fill the gap. Nigeria Demographic and Health Survey, 2008 dataset on married women aged 15-49 (N = 24,986) was used. Chi-square, OLS regression and Cox proportional hazard models were used in the analysis. The mean AFM was 17.8 +/- 4.8 years and significant difference existed between the mean AFM of women in the North (16.0 +/- 3.6) and South (20.4 +/- 5.0) (p < 0.001). Region, education, religion, residence, nutritional status, age at first sexual intercourse and children ever born were significantly associated with timing of first marriage (p < 0.001). Majority of the women married between ages 15-19 years (43.1%), while very few married late (2.3%) and about 27.0% married too early (less than 15 years). Early marriage was more common in all the regions in the North than the South and the hazard was highest in the North West and North East. Women who reside in rural area (H.R = 1.15; C.I = 1.11-1.18) married early than their counterparts in the urban area. Age at first marriage was directly related to levels of education (p < 0.001). Muslim women married early (H.R = 1.34; C.I = 1.29-1.39) than Christians. Three models were generated from the data. Women married too early in Nigeria with Teenage marriage more common in the North than the South. Education has influence on AFM; therefore, women should have at least secondary education before marriage in Nigeria.

  14. New U-Pb zircon ages and the duration and division of Devonian time

    USGS Publications Warehouse

    Tucker, R.D.; Bradley, D.C.; Ver Straeten, C.A.; Harris, A.G.; Ebert, J.R.; McCutcheon, S.R.

    1998-01-01

    Newly determined U-Pb zircon ages of volcanic ashes closely tied to biostratigraphic zones are used to revise the Devonian time-scale. They are: 1) 417.6 ?? 1.0 Ma for an ash within the conodont zone of Icriodus woschmidti/I. w. hesperius Lochkovian); 2) 408.3 ?? 1.9 Ma for an ash of early Emsian age correlated with the conodont zones of Po. dehiscens--Lower Po. inversus; 3) 391.4 ?? 1.8 Ma for an ash within the Po. c. costatus Zone and probably within the upper half of the zone (Eifelian); and 4) 381.1 ?? 1.3 Ma for an ash within the range of the Frasnian conodont Palmatolepis punctata (Pa. punctata Zone to Upper Pa. hassi Zone). U-Pb zircon ages for two rhyolites bracketing a palyniferous bed of the pusillites-lepidophyta spore zone, are dated at 363.8 ?? 2.2 Ma and 363 ?? 2.2 Ma and 363.4 ?? 1.8 Ma, respectively, suggesting an age of ~363 Ma for a level within the late Famennian Pa. g. expansa Zone. These data, together with other published zircon ages, suggest that the base and top of the Devonian lie close to 418 Ma and 362 Ma, respectively, thus lengthening the period of ~20% over current estimates. We suggest that the duration of the Middle Devonian (Eifelian and Givitian) is rather brief, perhaps no longer than 11.5 Myr (394 Ma-382.5 Ma), and that the Emsian and Famennian are the longest stages in the period with estimated durations of ~15.5 Myr and 14.5 Myr, respectively.

  15. Quality Saving Mechanisms of Mitochondria during Aging in a Fully Time-Dependent Computational Biophysical Model

    PubMed Central

    Mellem, Daniel; Fischer, Frank; Jaspers, Sören; Wenck, Horst; Rübhausen, Michael

    2016-01-01

    Mitochondria are essential for the energy production of eukaryotic cells. During aging mitochondria run through various processes which change their quality in terms of activity, health and metabolic supply. In recent years, many of these processes such as fission and fusion of mitochondria, mitophagy, mitochondrial biogenesis and energy consumption have been subject of research. Based on numerous experimental insights, it was possible to qualify mitochondrial behaviour in computational simulations. Here, we present a new biophysical model based on the approach of Figge et al. in 2012. We introduce exponential decay and growth laws for each mitochondrial process to derive its time-dependent probability during the aging of cells. All mitochondrial processes of the original model are mathematically and biophysically redefined and additional processes are implemented: Mitochondrial fission and fusion is separated into a metabolic outer-membrane part and a protein-related inner-membrane part, a quality-dependent threshold for mitophagy and mitochondrial biogenesis is introduced and processes for activity-dependent internal oxidative stress as well as mitochondrial repair mechanisms are newly included. Our findings reveal a decrease of mitochondrial quality and a fragmentation of the mitochondrial network during aging. Additionally, the model discloses a quality increasing mechanism due to the interplay of the mitophagy and biogenesis cycle and the fission and fusion cycle of mitochondria. It is revealed that decreased mitochondrial repair can be a quality saving process in aged cells. Furthermore, the model finds strategies to sustain the quality of the mitochondrial network in cells with high production rates of reactive oxygen species due to large energy demands. Hence, the model adds new insights to biophysical mechanisms of mitochondrial aging and provides novel understandings of the interdependency of mitochondrial processes. PMID:26771181

  16. Adults’ reports of their earliest memories: Consistency in events, ages, and narrative characteristics over time

    PubMed Central

    Bauer, Patricia J.; Tasdemir-Ozdes, Aylin; Larkina, Marina

    2014-01-01

    Earliest memories have been of interest since the late 1800s, when it was first noted that most adults do not have memories from the first years of life (so-called childhood amnesia). Several characteristics of adults’ earliest memories have been investigated, including emotional content, the perspective from which they are recalled, and vividness. The focus of the present research was a feature of early memories heretofore relatively neglected in the literature, namely, their consistency. Adults reported their earliest memories 2 to 4 times over a 4-year period. Reports of earliest memories were highly consistent in the events identified as the bases for earliest memories, the reported age at the time of the event, and in terms of qualities of the narrative descriptions. These findings imply stability in the boundary that marks the offset of childhood amnesia, as well as in the beginning of a continuous sense of self over time. PMID:24836979

  17. DEVELOPMENT OF METHODOLOGY AND FIELD DEPLOYABLE SAMPLING TOOLS FOR SPENT NUCLEAR FUEL INTERROGATION IN LIQUID STORAGE

    SciTech Connect

    Berry, T.; Milliken, C.; Martinez-Rodriguez, M.; Hathcock, D.; Heitkamp, M.

    2012-06-04

    This project developed methodology and field deployable tools (test kits) to analyze the chemical and microbiological condition of the fuel storage medium and determine the oxide thickness on the spent fuel basin materials. The overall objective of this project was to determine the amount of time fuel has spent in a storage basin to determine if the operation of the reactor and storage basin is consistent with safeguard declarations or expectations. This project developed and validated forensic tools that can be used to predict the age and condition of spent nuclear fuels stored in liquid basins based on key physical, chemical and microbiological basin characteristics. Key parameters were identified based on a literature review, the parameters were used to design test cells for corrosion analyses, tools were purchased to analyze the key parameters, and these were used to characterize an active spent fuel basin, the Savannah River Site (SRS) L-Area basin. The key parameters identified in the literature review included chloride concentration, conductivity, and total organic carbon level. Focus was also placed on aluminum based cladding because of their application to weapons production. The literature review was helpful in identifying important parameters, but relationships between these parameters and corrosion rates were not available. Bench scale test systems were designed, operated, harvested, and analyzed to determine corrosion relationships between water parameters and water conditions, chemistry and microbiological conditions. The data from the bench scale system indicated that corrosion rates were dependent on total organic carbon levels and chloride concentrations. The highest corrosion rates were observed in test cells amended with sediment, a large microbial inoculum and an organic carbon source. A complete characterization test kit was field tested to characterize the SRS L-Area spent fuel basin. The sampling kit consisted of a TOC analyzer, a YSI

  18. Reducing uncertainties affecting the assessment of the long-term corrosion behavior of spent nuclear fuel.

    PubMed

    Fanghänel, Thomas; Rondinella, Vincenzo V; Glatz, Jean-Paul; Wiss, Thierry; Wegen, Detlef H; Gouder, Thomas; Carbol, Paul; Serrano-Purroy, Daniel; Papaioannou, Dimitrios

    2013-04-01

    Reducing the uncertainties associated with extrapolation to very long term of corrosion data obtainable from laboratory tests on a relatively young spent nuclear fuel is a formidable challenge. In a geologic repository, spent nuclear fuel may come in contact with water tens or hundreds of thousands of years after repository closure. The corrosion behavior will depend on the fuel properties and on the conditions characterizing the near field surrounding the spent fuel at the time of water contact. This paper summarizes the main conclusions drawn from multiyear experimental campaigns performed at JRC-ITU to study corrosion behavior and radionuclide release from spent light water reactor fuel. The radionuclide release from the central region of a fuel pellet is higher than that from the radial periphery, in spite of the higher burnup and the corresponding structural modifications occurring at the pellet rim during irradiation. Studies on the extent and time boundaries of the radiolytic enhancement of the spent fuel corrosion rate indicate that after tens or hundreds of thousands of years have elapsed, very small or no contribution to the enhanced corrosion rate has to be expected from α radiolysis. A beneficial effect inhibiting spent fuel corrosion due to the hydrogen overpressure generated in the near field by iron corrosion is confirmed. The results obtained so far point toward a benign picture describing spent fuel corrosion in a deep geologic repository. More work is ongoing to further reduce uncertainties and to obtain a full description of the expected corrosion behavior of spent fuel.

  19. Aging, Disablement, and Dying: Using Time-as-Process and Time-as-Resources Metrics to Chart Late-Life Change.

    PubMed

    Ram, Nilam; Gerstorf, Denis; Fauth, Elizabeth; Zarit, Steven; Malmberg, Bo

    2010-01-01

    Time is a vehicle that can be used to represent aging-related processes and to index the amount of aging-related resources or burdens individuals have accumulated. Using data on cognitive (memory) performance from two Swedish studies of the elderly (OCTO and OCTO-TWIN), we illustrate how time-as-process and time-as-resources/burdens time metrics can be articulated and incorporated within a growth curve modeling framework. Our results highlight the possibilities for representing the contributions of primary, secondary, and tertiary aspects of aging to late-life changes in cognitive and other domains of functioning.

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

    PubMed

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

    2011-07-01

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

  1. Comparisons of neurodegeneration over time between healthy ageing and Alzheimer's disease cohorts via Bayesian inference

    PubMed Central

    Mengersen, Kerrie

    2017-01-01

    Objectives In recent years, large-scale longitudinal neuroimaging studies have improved our understanding of healthy ageing and pathologies including Alzheimer's disease (AD). A particular focus of these studies is group differences and identification of participants at risk of deteriorating to a worse diagnosis. For this, statistical analysis using linear mixed-effects (LME) models are used to account for correlated observations from individuals measured over time. A Bayesian framework for LME models in AD is introduced in this paper to provide additional insight often not found in current LME volumetric analyses. Setting and participants Longitudinal neuroimaging case study of ageing was analysed in this research on 260 participants diagnosed as either healthy controls (HC), mild cognitive impaired (MCI) or AD. Bayesian LME models for the ventricle and hippocampus regions were used to: (1) estimate how the volumes of these regions change over time by diagnosis, (2) identify high-risk non-AD individuals with AD like degeneration and (3) determine probabilistic trajectories of diagnosis groups over age. Results We observed (1) large differences in the average rate of change of volume for the ventricle and hippocampus regions between diagnosis groups, (2) high-risk individuals who had progressed from HC to MCI and displayed similar rates of deterioration as AD counterparts, and (3) critical time points which indicate where deterioration of regions begins to diverge between the diagnosis groups. Conclusions To the best of our knowledge, this is the first application of Bayesian LME models to neuroimaging data which provides inference on a population and individual level in the AD field. The application of a Bayesian LME framework allows for additional information to be extracted from longitudinal studies. This provides health professionals with valuable information of neurodegeneration stages, and a potential to provide a better understanding of disease pathology

  2. The time of our lives: recognizing the contributions of Mannheim, Neugarten, and Riley to the study of aging.

    PubMed

    Ferraro, Kenneth F

    2014-02-01

    Time is central to the study of aging, but multiple dimensions of time, especially its subjective sense, merit more systematic attention in gerontology. This essay honors the intellectual legacy of Karl Mannheim, Bernice Neugarten, Matilda Riley, and others for drawing attention to the social dimensions of time relevant for the scientific study of aging. I summarize major contributions of these social scientists for the study of aging and note points of overlap and distinction. Although their writings have led gerontologists to think more systematically about life course timing and trajectories, there is relatively little empirical research on temporal perceptions in such trajectories and the interplay of objective and subjective elements of time.

  3. Time-Dependent Behavior of a Graphite/Thermoplastic Composite and the Effects of Stress and Physical Aging

    NASA Technical Reports Server (NTRS)

    Gates, Thomas S.; Feldman, Mark

    1995-01-01

    Experimental studies were performed to determine the effects of stress and physical aging on the matrix dominated time dependent properties of IM7/8320 composite. Isothermal tensile creep/aging test techniques developed for polymers were adapted for testing of the composite material. Time dependent transverse and shear compliance's for an orthotropic plate were found from short term creep compliance measurements at constant, sub-T(8) temperatures. These compliance terms were shown to be affected by physical aging. Aging time shift factors and shift rates were found to be a function of temperature and applied stress.

  4. Sleep timing and quantity in ecological and family context: a nationally representative time-diary study.

    PubMed

    Adam, Emma K; Snell, Emily K; Pendry, Patricia

    2007-03-01

    Associations between demographic characteristics, school schedules, activity choices, family functioning, and sleep behaviors were estimated using nationally representative time-diary data from 2,454 children (ages 5.5 to 11.9 years) and adolescents (ages 12.0 to 19.1 years). For weekdays, African American adolescents, Asian children, and those with earlier school start times and longer travel times to school reported fewer sleep hours. More time spent watching television (for children), doing homework (for adolescents), and engaging in religious activities predicted fewer hours, whereas a longer time spent on meals predicted greater hours of weekday sleep. For younger children, greater parental warmth predicted more hours of weekday sleep, whereas for adolescents, stricter household rules were protective. On weekends, African American adolescents and Hispanic children slept less, and there were strong effects of activity choices including time spent on television, computer and videogames, sports, religious activities, socializing, and employment. In accounting for age-related decreases in sleep hours from childhood to adolescence, earlier school start times, greater hours of homework, greater paid employment, less time spent on meals, and fewer household rules were all significant mediators.

  5. [Population ageing and health implication. Thinking time trends in Emilia-Romagna Region].

    PubMed

    Mazzocchetti, Angelina; Caranci, Nicola; Addis, Antonio

    2014-05-01

    Ageing is doubtless a factor characterizing population in Europe, and particularly in Emilia-Romagna, a north-east Italian region of about 4,5 million people. From 1990 to 2010 life expectancy in Emilia-Romagna has grown by about 6 years for men and 5 for women. At the same time good health life expectancy has grown even more rapidly, particularly among women. While it is expected that in 2030 the number of over-65s will have exceeded one million people, the trends in good health life expectancy is not granted. Strengthen actions aimed at increasing good health conditions promotes ageing sustainability and can feed the positive trend observed for the life expectancy in good health. The Emilia-Romagna Region takes up the demographic challenge of the coming years in the European context and promotes strategies for active and healthy ageing, working on prevention in its broadest sense and for the entire life span, with the aim of actively contribute to the achievement of the EU2020 target of an increase of two years in life expectancy in good health of European citizens.

  6. Effects of body weight and age on the time and pairing of American black ducks

    USGS Publications Warehouse

    Hepp, G.R.

    1986-01-01

    I used captive young and adult American Black Ducks (Anas rubripes) during October-February 1984-1985 to test whether body weight and age affected time of pair-bond formation. Eighty ducks were marked individually, and 10 ducks (6 males and 4 females, half of each age class) were assigned to each of 8 experimental pens. Ducks in 4 pens received an ad libitum diet of commercial duck food, and ducks in the other 4 pens received a restricted ration of the same food. During early winter ducks in both groups gained weight, but ducks on the restricted diet gained less than birds on the ad libitum diet; peak winter weight of ducks on the ad libitum diet averaged 22% greater than initial body weight compared with 6.5% for ducks on the restricted diet. In late winter ducks on the restricted diet lost 28.7% of peak winter weight, and ducks on the ad libitum diet lost 19.3%. Weight loss of ducks on the ad libitum diet began before weather conditions became severe and coincided with a reduction in food consumption. This result supports the idea that weight loss of waterfowl in late winter is controlled endogenously. Individuals on the ad libitum diet paired earlier than those on the restricted diet, and pair bonds were stronger. Adults of both sexes paired earlier than young ducks, but differences for females were not significant statistically. Age and energy constraints are factors that can affect intraspecific variation in pairing chronology.

  7. Near-term commercial spent fuel shipping cask requirements

    SciTech Connect

    Daling, P.M.

    1984-11-01

    This report describes an analysis of the near-term commercial light water reactor (LWR) spent fuel transportation system. The objective was to determine if the existing commercial spent fuel shipping cask fleet is adequate to provide the needed transportation services for the period of time the US government would be authorized to accept spent fuel for Federal Interim Storage (FIS). A spent fuel shipping cask supply-demand analysis was performed to evaluate the existing fleet size. The results of the shipping cask handling capability study indicated that by weight, 75% of the spent fuel shipments will be by truck (overweight plus legal-weight truck). From the results of the shipping cask supply-demand analysis it was concluded that, if utilities begin large-scale applications for FIS, the five legal-weight truck (LWT) casks currently in service would be inadequate to perform all of the needed shipments as early as 1987. This further assumes that a western site would be selected for the FIS facility. If the FIS site were to be located in the East, the need for additional LWT casks would be delayed by about two years. The overweight truck (OWT) cask fleet (two PWR and two BWR versions) will be adequate through 1992 if some shipments to FIS can be made several years before a reactor is projected to lose full core reserve. This is because OWT cask requirements increase gradually over the next several years. The feasibility of shipping before losing full core reserve has not been evaluated. Cask utilization requirements in later years will be reduced if some shipments can be made prior to the time they are actually needed. The existing three rail casks are adequate to perform near-term shipments. 18 references, 4 figures, 18 tables.

  8. Performance of a Treatment Loop for Recycling Spent Rinse Waters

    SciTech Connect

    DONOVAN,ROBERT PATRICK; TIMON,ROBERT P.; DEBUSK,MICHAEL JOHN; JONES,RONALD V.; ROGERS,DARELL M.

    2000-11-15

    This paper summarizes an evaluation of a treatment loop designed to upgrade the quality of spent rinse waters discharged from 10 wet benches located in the fab at Sandia's Microelectronics Development Laboratory (MDL). The goal of the treatment loop is to make these waters, presently being discharged to the fab's acid waste neutralization (AWN) station, suitable for recycling as feed water back into the fab's ultrapure water (UPW) plant. The MDL typically operates 2 shifts per day, 5 days per week. Without any treatment, the properties of the spent rinse waters now being collected have been shown to be compatible with recycling about 30% (50/168) of the time (weekends primarily, when the fab is idling) which corresponds to about 12% of the present water discharged from the fab to the AWN. The primary goal of adding a treatment loop is to increase the percentage of recyclable water from these 10 wet benches to near 100%, increasing the percentage of total recyclable water to near 40% of the total present fab discharge to the AWN. A second goal is to demonstrate compatibility with recycling this treated spent rinse water to the present R/O product water tank, reducing both the present volume of R/O reject water and the present load on the R/O. The approach taken to demonstrate achieving these goals is to compare all the common metrics of water quality for the treated spent rinse waters with those of the present R/O product water. Showing that the treated rinse water is equal or superior in quality to the water presently stored in the R/O tank by every metric all the time is assumed to be sufficient argument for proceeding with plans to incorporate recycling of these spent rinse waters back into MDL's R/O tank.

  9. Safeguards for spent fuels: Verification problems

    SciTech Connect

    Pillay, K.K.S.; Picard, R.R.

    1991-01-01

    The accumulation of large quantities of spent nuclear fuels world-wide is a serious problem for international safeguards. A number of International Atomic Energy Agency (IAEA) member states, including the US, consider spent fuel to be a material form for which safeguards cannot be terminated, even after permanent disposal in a geologic repository. Because safeguards requirements for spent fuels are different from those of conventional bulk-handling and item-accounting facilities, there is room for innovation to design a unique safeguards regime for spent fuels that satisfies the goals of the nuclear nonproliferation treaty at a reasonable cost to both the facility and the IAEA. Various strategies being pursued for long-term management of spent fuels are examined with a realistic example to illustrate the problems of verifying safeguards under the present regime. Verification of a safeguards regime for spent fuels requires a mix of standard safeguards approaches, such as quantitative verification and use of seals, with other measures that are unique to spent fuels. 17 refs.

  10. The End Is (Not) Near: Aging, Essentialism, and Future Time Perspective

    ERIC Educational Resources Information Center

    Weiss, David; Job, Veronika; Mathias, Maya; Grah, Stephanie; Freund, Alexandra M.

    2016-01-01

    Beliefs about aging influence how we interpret and respond to changes within and around us. Essentialist beliefs about aging are defined as views that link chronological age with inherent and immutable properties underlying aging-related changes. These beliefs may influence the experience of aging-related changes and shape people's outlook of the…

  11. A Monte Carlo based spent fuel analysis safeguards strategy assessment

    SciTech Connect

    Fensin, Michael L; Tobin, Stephen J; Swinhoe, Martyn T; Menlove, Howard O; Sandoval, Nathan P

    2009-01-01

    Safeguarding nuclear material involves the detection of diversions of significant quantities of nuclear materials, and the deterrence of such diversions by the risk of early detection. There are a variety of motivations for quantifying plutonium in spent fuel assemblies by means of nondestructive assay (NDA) including the following: strengthening the capabilities of the International Atomic Energy Agencies ability to safeguards nuclear facilities, shipper/receiver difference, input accountability at reprocessing facilities and burnup credit at repositories. Many NDA techniques exist for measuring signatures from spent fuel; however, no single NDA technique can, in isolation, quantify elemental plutonium and other actinides of interest in spent fuel. A study has been undertaken to determine the best integrated combination of cost effective techniques for quantifying plutonium mass in spent fuel for nuclear safeguards. A standardized assessment process was developed to compare the effective merits and faults of 12 different detection techniques in order to integrate a few techniques and to down-select among the techniques in preparation for experiments. The process involves generating a basis burnup/enrichment/cooling time dependent spent fuel assembly library, creating diversion scenarios, developing detector models and quantifying the capability of each NDA technique. Because hundreds of input and output files must be managed in the couplings of data transitions for the different facets of the assessment process, a graphical user interface (GUI) was development that automates the process. This GUI allows users to visually create diversion scenarios with varied replacement materials, and generate a MCNPX fixed source detector assessment input file. The end result of the assembly library assessment is to select a set of common source terms and diversion scenarios for quantifying the capability of each of the 12 NDA techniques. We present here the generalized

  12. The timing and precision of action prediction in the aging brain

    PubMed Central

    Jones, Alex L.; Cross, Emily S.

    2015-01-01

    Abstract Successful social interactions depend on the ability to anticipate other people's actions. Current conceptualizations of brain function propose that causes of sensory input are inferred through their integration with internal predictions generated in the observer's motor system during action observation. Less is known concerning how action prediction changes with age. Previously we showed that internal action representations are less specific in older compared with younger adults at behavioral and neural levels. Here, we characterize how neural activity varies while healthy older adults aged 56–71 years predict the time‐course of an unfolding action as well as the relation to task performance. By using fMRI, brain activity was measured while participants observed partly occluded actions and judged the temporal coherence of the action continuation that was manipulated. We found that neural activity in frontoparietal and occipitotemporal regions increased the more an action continuation was shifted backwards in time. Action continuations that were shifted towards the future preferentially engaged early visual cortices. Increasing age was associated with neural activity that extended from posterior to anterior regions in frontal and superior temporal cortices. Lower sensitivity in action prediction resulted in activity increases in the caudate. These results imply that the neural implementation of predicting actions undergoes similar changes as the neural process of executing actions in older adults. The comparison between internal predictions and sensory input seems to become less precise with age leading to difficulties in anticipating observed actions accurately, possibly due to less specific internal action models. Hum Brain Mapp 37:54–66, 2016. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. PMID:26503586

  13. Time dependent behavior of a graphite/thermoplastic composite and the effects of stress and physical aging

    NASA Technical Reports Server (NTRS)

    Gates, Thomas S.; Feldman, Mark

    1993-01-01

    Two complimentary studies were performed to determine the effects of stress and physical aging on the matrix dominated time dependent properties of IM7/8320 composite. The first of these studies, experimental in nature, used isothermal tensile creep/aging test techniques developed for polymers and adapted them for testing of the composite material. From these tests, the time dependent transverse (S22) and shear (S66) compliance's for an orthotropic plate were found from short term creep compliance measurements at constant, sub-T(sub g) temperatures. These compliance terms were shown to be affected by physical aging. Aging time shift factors and shift rates were found to be a function of temperature and applied stress. The second part of the study relied upon isothermal uniaxial tension tests of IM7/8320 to determine the effects of physical aging on the nonlinear material behavior at elevated temperature. An elastic/viscoplastic constitutive model was used to quantify the effects of aging on the rate-independent plastic and rate-dependent viscoplastic response. Sensitivity of the material constants required by the model to aging time were determined for aging times up to 65 hours. Verification of the analytical model indicated that the effects of prior aging on the nonlinear stress/strain/time data of matrix dominated laminates can be predicted.

  14. Age differences in subjective well-being across adulthood: the roles of savoring and future time perspective.

    PubMed

    Ramsey, Meagan A; Gentzler, Amy L

    2014-01-01

    Prior research indicates there are age differences in subjective well-being during adulthood, but research on age differences in savoring (up-regulating positive emotion) is lacking. Using an online survey (N = 218, adults 18-77), this study investigated age differences in subjective well-being and savoring, and whether future time perspective (perceived amount of time left to live) mediated associations between age and savoring. Results indicated a nonlinear effect of age on subjective well-being. Although savoring was associated with subjective well-being, age was not directly associated with savoring. However, an indirect effect of future time perspective linking age and savoring indicated that younger adults reported more perceived time left in life and those perceiving more time left in life reported greater savoring. Overall, the results do not support savoring as a direct explanatory mechanism for age differences in subjective well-being, but future time perspective appears to play an important role in indirect associations between age and savoring.

  15. Campaign 1.7 Pu Aging. Development of Time of Flight Secondary Ion Mass Spectroscopy

    SciTech Connect

    Venhaus, Thomas J.

    2015-09-09

    The first application of Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) to an aged plutonium surface has resulted in a rich set of surface chemistry data, as well as some unexpected results. FY15 was highlighted by not only the first mapping of hydrogen-containing features within the metal, but also a prove-in series of experiments using the system’s Sieverts Reaction Cell. These experiments involved successfully heating the sample to ~450 oC for nearly 24 hours while the sample was dosed several times with hydrogen, followed by an in situ ToF-SIMS analysis. During this year, the data allowed for better and more consistent identification of the myriad peaks that result from the SIMS sputter process. In collaboration with the AWE (U.K), the system was also fully aligned for sputter depth profiling for future experiments.

  16. Medicare, Ethics, and Reflexive Longevity: Governing Time and Treatment in an Aging Society

    PubMed Central

    Kaufman, Sharon R.; Fjord, Lakshmi

    2013-01-01

    The clinical activities that constitute longevity making in the United States are perhaps the quintessential example of a dynamic modern temporality, characterized by the quest for risk reduction, the powerful progress narratives of science and medicine, and the personal responsibility of calculating the worth of more time in relation to medical options and age. This article explores how medicine materializes and problematizes time through a discussion of ethicality—in this case, the form of governance in which scientific evidence, Medicare policy and clinical knowledge and practice organize first, what becomes “thinkable” as the best medicine, and second, how that kind of understanding shapes a telos of living. Using liver disease and liver transplantation in the United States as my example, I explore the influence of Medicare coverage decisions on treatments, clinical standards, and ethical necessity. Reflexive longevity—a relentless future-thinking about life itself—is one feature of this ethicality. PMID:21834359

  17. Effect of ageing time on mechanical properties of plasticized poly(hydroxybutyrate) (PHB)

    NASA Astrophysics Data System (ADS)

    Farris, Giuseppe; Cinelli, Patrizia; Anguillesi, Irene; Salvadori, Sara; Coltelli, Maria-Beatrice; Lazzeri, Andrea

    2014-05-01

    Polyhydroxybutyrate (PHB) based materials were prepared by melt extrusion by using different plasticizers, such as poly(ethylene glycol)s (PEG)s having different molecular weight (400, 1500 and 4000). The plasticizers content was varied in the range 10-20% by weight versus the PHB polymeric matrix. The variation of tensile properties of the different samples was monitored as a function of time of ageing to study the stability of the material. The elastic modulus and tensile strength increased as a function of time, whereas the strain at break decreased. The experimental results were explained by considering both the demixing of the plasticizers and the occurring of secondary crystallization. Moreover the variation in mechanical properties was correlated to the structure and concentration of the different plasticizers employed.

  18. Aging, Fitness, and Marathon Times in a 91 Year-old Man Who Competed in 627 Marathons.

    PubMed

    Addison, Odessa; Steinbrenner, Gregory; Goldberg, Andrew P; Katzel, Leslie I

    Aging is associated with a decline in maximal aerobic capacity (VO2max) that may be attenuated by chronic endurance exercise. This case study chronicles the changes in marathon times in a 91 year old man who completed 627 marathons and 117 ultramarathons over 42 years. He began running marathons at age 48. His yearly best times remained fairly constant at ~240 minutes from age 50 - 64 years and then gradually rose to about 260 minutes in his early seventies followed by a curvilinear deterioration as he approached his ninth decade. His times plateaued at ~ 600 minutes in his late eighties. Between ages 68 and 89 his VO2max declined from 43 to 20 ml/kg/min. His marathon times were highly correlated with his VO2max (r(2)=0.87). The decline in marathons times and VO2max may reflect the contributions of biological aging, changes in exercise training volume and intensity, injuries, and comorbid disease.

  19. Simulated Interventions to Ameliorate Age-Related Bone Loss Indicate the Importance of Timing

    PubMed Central

    Proctor, Carole J.; Gartland, Alison

    2016-01-01

    Bone remodeling is the continuous process of bone resorption by osteoclasts and bone formation by osteoblasts, in order to maintain homeostasis. The activity of osteoclasts and osteoblasts is regulated by a network of signaling pathways, including Wnt, parathyroid hormone (PTH), RANK ligand/osteoprotegrin, and TGF-β, in response to stimuli, such as mechanical loading. During aging there is a gradual loss of bone mass due to dysregulation of signaling pathways. This may be due to a decline in physical activity with age and/or changes in hormones and other signaling molecules. In particular, hormones, such as PTH, have a circadian rhythm, which may be disrupted in aging. Due to the complexity of the molecular and cellular networks involved in bone remodeling, several mathematical models have been proposed to aid understanding of the processes involved. However, to date, there are no models, which explicitly consider the effects of mechanical loading, the circadian rhythm of PTH, and the dynamics of signaling molecules on bone remodeling. Therefore, we have constructed a network model of the system using a modular approach, which will allow further modifications as required in future research. The model was used to simulate the effects of mechanical loading and also the effects of different interventions, such as continuous or intermittent administration of PTH. Our model predicts that the absence of regular mechanical loading and/or an impaired PTH circadian rhythm leads to a gradual decrease in bone mass over time, which can be restored by simulated interventions and that the effectiveness of some interventions may depend on their timing. PMID:27379013

  20. Mastering the Concepts of Geologic Time: Novice Students' Understanding of the Principles of Relative Age

    NASA Astrophysics Data System (ADS)

    Speta, M.; Reid, L.

    2010-12-01

    Misconceptions can adversely affect students’ mastery of the fundamental geoscience concepts necessary for development of the knowledge base required to become a professional geoscientist. In the fall of 2009, in-class learning assessments were introduced into a large (400 student) undergraduate introductory geoscience course to help students develop expert-like problem solving skills for geologic problems. They were also designed to reveal students’ misconceptions on geoscience concepts in order to help direct the course of instruction. These assessments were based on simple, real-world scenarios that geoscientists encounter in their research. One of these assessments focused on the application of concepts of geologic time. It asked students to give the relative ages of granite, schist and shale based on a sketch of two outcrops, and to describe the reasoning behind their answer. In order to test all of the principles of relative age, the assignment had two possible solutions. A post-course analysis of student responses on these assessments was carried out using a modified constant comparative analysis method to identify common misconceptions. This analysis revealed that 61% of students failed to identify both possible solutions. Furthermore, 55% of students applied the principle of superposition to intrusive igneous and metamorphic rocks, and 18% treated the once connected outcrops as having separate geologic histories. 56% of students could not support their proposed geologic history with appropriate reasoning. These results suggest that the principles of relative geologic time that students had the greatest difficulty with were when to apply the principle of superposition and how to apply the principle of original continuity. Students also had difficulty using the principles of relative age to provide appropriate scientific reasoning for their choices.

  1. Advances in HTGR spent fuel treatment technology

    SciTech Connect

    Holder, N.D.; Lessig, W.S.

    1984-08-01

    GA Technologies, Inc. has been investigating the burning of spent reactor graphite under Department of Energy sponsorship since 1969. Several deep fluidized bed burners have been used at the GA pilot plant to develop graphite burning techniques for both spent fuel recovery and volume reduction for waste disposal. Since 1982 this technology has been extended to include more efficient circulating bed burners. This paper includes updates on high-temperature gas-cooled reactor fuel cycle options and current results of spent fuel treatment testing for fluidized and advanced circulating bed burners.

  2. Microbial recovery of metals from spent catalysts

    SciTech Connect

    Sperl, P.L.; Sperl, G.T.

    1990-01-01

    This project was initiated on October 1, 1989, for the purpose of recovering metals from spent coal liquefaction catalysts. Two catalyst types are the subject of the contract. The first is a Ni-Mo catalyst supported on alumina (Shell 324) as is used in a pilot scale coal liquefaction facility at Wilsonville, Alabama. The object of the contract is to treat these spent catalysts with microorganisms, especially Thiobacillus ferrooxidans, but also other Thiobacillus sp., to leach and remove the metals (Ni and Mo) from the spent catalysts into a form which can be readily recovered by conventional techniques.

  3. Spent nuclear fuel reprocessing modeling

    SciTech Connect

    Tretyakova, S.; Shmidt, O.; Podymova, T.; Shadrin, A.; Tkachenko, V.; Makeyeva, I.; Tkachenko, V.; Verbitskaya, O.; Schultz, O.; Peshkichev, I.

    2013-07-01

    The long-term wide development of nuclear power requires new approaches towards the realization of nuclear fuel cycle, namely, closed nuclear fuel cycle (CNFC) with respect to fission materials. Plant nuclear fuel cycle (PNFC), which is in fact the reprocessing of spent nuclear fuel unloaded from the reactor and the production of new nuclear fuel (NF) at the same place together with reactor plant, can be one variant of CNFC. Developing and projecting of PNFC is a complicated high-technology innovative process that requires modern information support. One of the components of this information support is developed by the authors. This component is the programme conducting calculations for various variants of process flow sheets for reprocessing SNF and production of NF. Central in this programme is the blocks library, where the blocks contain mathematical description of separate processes and operations. The calculating programme itself has such a structure that one can configure the complex of blocks and correlations between blocks, appropriate for any given flow sheet. For the ready sequence of operations balance calculations are made of all flows, i.e. expenses, element and substance makeup, heat emission and radiation rate are determined. The programme is open and the block library can be updated. This means that more complicated and detailed models of technological processes will be added to the library basing on the results of testing processes using real equipment, in test operating mode. The development of the model for the realization of technical-economic analysis of various variants of technologic PNFC schemes and the organization of 'operator's advisor' is expected. (authors)

  4. Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

    SciTech Connect

    Cunningham, M.E.; Thomas, L.E.

    1995-06-01

    The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0{sub 2}) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations.

  5. Detrital Zircon U-Pb Age Populations in Time and Space in the Arctic Alaska Terrane

    NASA Astrophysics Data System (ADS)

    Moore, T. E.

    2010-12-01

    The Arctic Alaska Terrane (ATT) occupies the only margin of the Ameriasia Basin whose origin and position since Paleozoic time is incompletely known. To better understand its tectonic history, detrital zircon (DZ) U-Pb ages from about 75 samples of clastic strata were obtained from representative parts of the ATT in northern Alaska. The oldest known strata of the AAT are Neoproterozoic clastic rocks exposed in the northeastern Brooks Range. DZ dating of these rocks show that they contain abundant ~1.8 Ga zircons and subordinate populations that indicate derivation from the northwest part of Laurentia. Upper Neoproterozoic strata in the Brooks Range, in contrast, contain populations dominated by ~600 Ma zircons. The latter ages are similar to those in parts of the ATT outside of northern Alaska, including the Seward Peninsula, Chukotka, and Wrangel Island that are thought to have been derived from the Timanian orogen of northern Baltica. Similar DZ populations have also been obtained from Silurian sandstones of the Lisburne Peninsula, suggesting that much of the western and southern parts of AAT may have formed in or near northern Baltica. A third group of DZ ages were found in deformed clastic rocks that were deposited across large parts of the North Slope in the Silurian and/or Devonian and are also present in parautochthonous settings in the Brooks Range. These rocks typically are dominated by DZ ages of 390-470 Ma, and sometimes contain subordinate non-Laurentian populations of ~1.5 Ga. These DZ ages, the underlying rocks of probable Baltic and Laurentian affinity, and evidence of significant deformation indicate that the ATT may have been constructed by Caledonian tectonism in the Silurian and Devonian. Following Devonian deformation, Mississippian to Triassic platform strata of the Ellesmerian Sequence were deposited on a regional unconformity. DZ ages from these rocks appear to reflect the compositions of the sub-unconformity units and indicate that Timanian

  6. Learning to eat vegetables in early life: the role of timing, age and individual eating traits.

    PubMed

    Caton, Samantha J; Blundell, Pam; Ahern, Sara M; Nekitsing, Chandani; Olsen, Annemarie; Møller, Per; Hausner, Helene; Remy, Eloïse; Nicklaus, Sophie; Chabanet, Claire; Issanchou, Sylvie; Hetherington, Marion M

    2014-01-01

    Vegetable intake is generally low among children, who appear to be especially fussy during the pre-school years. Repeated exposure is known to enhance intake of a novel vegetable in early life but individual differences in response to familiarisation have emerged from recent studies. In order to understand the factors which predict different responses to repeated exposure, data from the same experiment conducted in three groups of children from three countries (n = 332) aged 4-38 m (18.9±9.9 m) were combined and modelled. During the intervention period each child was given between 5 and 10 exposures to a novel vegetable (artichoke puree) in one of three versions (basic, sweet or added energy). Intake of basic artichoke puree was measured both before and after the exposure period. Overall, younger children consumed more artichoke than older children. Four distinct patterns of eating behaviour during the exposure period were defined. Most children were "learners" (40%) who increased intake over time. 21% consumed more than 75% of what was offered each time and were labelled "plate-clearers". 16% were considered "non-eaters" eating less than 10 g by the 5th exposure and the remainder were classified as "others" (23%) since their pattern was highly variable. Age was a significant predictor of eating pattern, with older pre-school children more likely to be non-eaters. Plate-clearers had higher enjoyment of food and lower satiety responsiveness than non-eaters who scored highest on food fussiness. Children in the added energy condition showed the smallest change in intake over time, compared to those in the basic or sweetened artichoke condition. Clearly whilst repeated exposure familiarises children with a novel food, alternative strategies that focus on encouraging initial tastes of the target food might be needed for the fussier and older pre-school children.

  7. AN ALGORITHM FOR THE ESTIMATION OF GESTATIONAL AGE AT THE TIME OF FETAL DEATH

    PubMed Central

    Conway, Deborah L.; Hansen, Nellie I.; Dudley, Donald J.; Parker, Corette B.; Reddy, Uma M.; Silver, Robert M.; Bukowski, Radek; Pinar, Halit; Stoll, Barbara J.; Varner, Michael W.; Saade, George R.; Hogue, Carol; Willinger, Marian; Coustan, Donald; Koch, Matthew A.; Goldenberg, Robert L.

    2013-01-01

    Background Accurate assignment of gestational age at time of fetal death is important for research and clinical practice. An algorithm to estimate gestational age (GA) at fetal death was developed and evaluated. Methods The algorithm developed by the Stillbirth Collaborative Research Network (SCRN) incorporated clinical and postmortem data. The SCRN conducted a population-based case-control study of women with stillbirths and live births from 2006 to 2008 in five geographic catchment areas. Rules were developed to estimate a due date, identify an interval during which death likely occurred, and estimate GA at the time of fetal death. Reliability of using fetal foot length to estimate GA at death was assessed. Results The due date estimated for 620 singleton stillbirths studied was considered clinically reliable for 87%. Only 25.2% of stillbirths were documented alive within two days before diagnosis and 47.6% within one week of diagnosis. The algorithm-derived estimate of GA at time of fetal death was 1 or more weeks earlier than the GA at delivery for 43.5% of stillbirths. GA estimated from fetal foot length agreed with GA by algorithm within two weeks for 75% within a subset of well-dated stillbirths. Conclusions Precise assignment of GA at death, defined as reliable dating criteria and a short interval (≤1 week) during which fetal death was known to have occurred, was possible in 46.6% of cases. Fetal foot length is a relatively accurate measure of GA at death and should be collected in all stillbirth cases. PMID:23374059

  8. Sensitivity of proton NMR relaxation times in a HTPB based polyurethane elastomer to thermo-oxidative aging.

    SciTech Connect

    Assink, Roger Alan; Mowery, Daniel Michael; Celina, Mathias Christopher

    2004-09-01

    Solid-state {sup 1}H NMR relaxometry studies were conducted on a hydroxy-terminated polybutadiene (HTPB) based polyurethane elastomer thermo-oxidatively aged at 80 C. The {sup 1}H T{sub 1}, T{sub 2}, and T{sub 1{rho}} relaxation times of samples thermally aged for various periods of time were determined as a function of NMR measurement temperature. The response of each measurement was calculated from a best-fit linear function of the relaxation time vs. aging time. It was found that the T{sub 2,H} and T{sub 1{rho},H} relaxation times exhibited the largest response to thermal degradation, whereas T{sub 1,H} showed minimal change. All of the NMR relaxation measurements on solid samples showed significantly less sensitivity to thermal aging than the T{sub 2,H} relaxation times of solvent-swollen samples.

  9. Real time studies of Elastic Moduli Pu Aging using Resonant Ultrasound Spectroscopy

    NASA Astrophysics Data System (ADS)

    Maiorov, Boris

    Elastic moduli are fundamental thermodynamic susceptibilities that connect directly to thermodynamics, electronic structure and give important information about mechanical properties. To determine the time evolution of the elastic properties in 239Pu and it Ga alloys, is imperative to study its phase stability and self-irradiation damage process. The most-likely sources of these changes include a) ingrowth of radioactive decay products like He and U, b) the introduction of radiation damage, c) δ-phase instabilities towards α-Pu or to Pu3Ga. The measurement of mechanical resonance frequencies can be made with extreme precision and used to compute the elastic moduli without corrections giving important insight in this problem. Using Resonant Ultrasound Spectroscopy, we measured the time dependence of the mechanical resonance frequencies of fine-grained polycrystalline δ-phase 239Pu, from 300K up to 480K. At room temperature, the shear modulus shows an increase in time (stiffening), but the bulk modulus decreases (softening). These are the first real-time measurements of room temperature aging of the elastic moduli, and the changes are consistent with elastic moduli measurements performed on 44 year old δ-Pu. As the temperature is increased, the rate of change increases exponentially, with both moduli becoming stiffer with time. For T>420K an abrupt change in the time dependence is observed indicating that the bulk and shear moduli have opposite rates of change. Our measurements provide a basis for ruling out the decomposition of δ-Pu towards α-Pu or Pu3Ga, and indicate a complex defect-related scenario from which we are gathering important clues.

  10. Safeguards aspects of spent-fuel management

    SciTech Connect

    Richter, B.; Stein, G.; Remagen, H.H.; Weh, R.

    1989-11-01

    In the Federal Republic of Germany, the concept of spent-fuel management is based on a closed fuel cycle that has the following principal features: (1) intermediate dry storage of spent fuel; (2) reprocessing; (3) thermal recycling of unconsumed nuclear material; and (4) conditioning and final disposal of radioactive waste. Complementary to this concept, methods and techniques for the direct final disposal of spent fuel are under development, including investigations of licensing issues. Furthermore, a licensing procedure is under way for the construction of a pilot conditioning plant close to the Gorleben dry storage facility. Apart from operational safety and environmental protection, the issue of international safeguards is of paramount interest. This paper discusses safeguards aspects of spent-fuel management related to direct final disposal.

  11. Spent fuel storage requirements 1993--2040

    SciTech Connect

    Not Available

    1994-09-01

    Historical inventories of spent fuel are combined with U.S. Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the United States to provide estimates of spent fuel storage requirements through the year 2040. The needs are estimated for storage capacity beyond that presently available in the reactor storage pools. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of spent fuel to other reactors or facilities. Existing and future dry storage facilities are also discussed. The nuclear utilities provide historical data through December 1992 on the end of reactor life are based on the DOE/Energy Information Administration (EIA) estimates of future nuclear capacity, generation, and spent fuel discharges.

  12. Nuclear mass inventory, photon dose rate and thermal decay heat of spent research reactor fuel assemblies

    SciTech Connect

    Pond, R.B.; Matos, J.E.

    1996-12-31

    This document has been prepared to assist research reactor operators possessing spent fuel containing enriched uranium of United States origin to prepare part of the documentation necessary to ship this fuel to the United States. Data are included on the nuclear mass inventory, photon dose rate, and thermal decay heat of spent research reactor fuel assemblies. Isotopic masses of U, Np, Pu and Am that are present in spent research reactor fuel are estimated for MTR, TRIGA and DIDO-type fuel assembly types. The isotopic masses of each fuel assembly type are given as functions of U-235 burnup in the spent fuel, and of initial U-235 enrichment and U-235 mass in the fuel assembly. Photon dose rates of spent MTR, TRIGA and DIDO-type fuel assemblies are estimated for fuel assemblies with up to 80% U-235 burnup and specific power densities between 0.089 and 2.857 MW/kg[sup 235]U, and for fission product decay times of up to 20 years. Thermal decay heat loads are estimated for spent fuel based upon the fuel assembly irradiation history (average assembly power vs. elapsed time) and the spent fuel cooling time.

  13. Combustion of Australian spent shales compared

    SciTech Connect

    Not Available

    1986-12-01

    The combustion kinetics of spent oil shales from seven major Australian deposits have been examined using a fluidized bed batch technique. Chemical rate constants were shown to vary between the shales and to be less than extrapolations of data from American spent oil shales. The effective diffusivity also varies widely among the shales. The seven oil shales were from the Condor, Duaringa, Lowmead, Nagoorin, Nagoorin South, Rundle and Stuart deposits in Queensland. Results are briefly described. 1 figure, 1 table.

  14. HYDRAULIC CEMENT PREPARATION FROM LURGI SPENT SHALE

    SciTech Connect

    Mehta, P.K.; Persoff, P.; Fox, J.P.

    1980-06-01

    Low cost material is needed for grouting abandoned retorts. Experimental work has shown that a hydraulic cement can be produced from Lurgi spent shale by mixing it in a 1:1 weight ratio with limestone and heating one hour at 1000°C. With 5% added gypsum, strengths up to 25.8 MPa are obtained. This cement could make an economical addition up to about 10% to spent shale grout mixes, or be used in ordinary cement applications.

  15. Rack for storing spent nuclear fuel elements

    DOEpatents

    Rubinstein, Herbert J.; Clark, Philip M.; Gilcrest, James D.

    1978-06-20

    A rack for storing spent nuclear fuel elements in which a plurality of aligned rows of upright enclosures of generally square cross-sectional areas contain vertically disposed fuel elements. The enclosures are fixed at the lower ends thereof to a base. Pockets are formed between confronting walls of adjacent enclosures for receiving high absorption neutron absorbers, such as Boral, cadmium, borated stainless steel and the like for the closer spacing of spent fuel elements.

  16. Frontal plane hip and ankle sensorimotor function, not age, predicts unipedal stance time

    PubMed Central

    Allet, Lara; Kim, Hogene; Ashton-Miller, James; De Mott, Trina; Richardson, James K.

    2011-01-01

    Introduction Changes occur in muscles and nerves with aging. This study aimed to explore the relationship between unipedal stance time (UST) and frontal plane hip and ankle sensorimotor function in subjects with diabetic neuropathy. Methods UST, quantitative measures of frontal plane ankle proprioceptive thresholds, and ankle and hip motor function were tested in forty-one persons with a spectrum of lower limb sensorimotor function, ranging from healthy to moderately severe diabetic neuropathy. Results Frontal plane hip and ankle sensorimotor function demonstrated significant relationships with UST. Multivariate analysis identified only composite hip strength, composite ankle proprioceptive threshold, and age to be significant predictors of UST (R2=0.73); they explained 46%, 24% and 3% of the variance, respectively. Discussion/Conclusions Frontal plane hip strength was the single best predictor of UST and appeared to compensate for less precise ankle proprioceptive thresholds. This finding is clinically relevant given the possibility of strengthening the hip, even in patients with significant PN. . PMID:22431092

  17. 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.

  18. A 'snip' in time: what is the best age to circumcise?

    PubMed Central

    2012-01-01

    Background Circumcision is a common procedure, but regional and societal attitudes differ on whether there is a need for a male to be circumcised and, if so, at what age. This is an important issue for many parents, but also pediatricians, other doctors, policy makers, public health authorities, medical bodies, and males themselves. Discussion We show here that infancy is an optimal time for clinical circumcision because an infant's low mobility facilitates the use of local anesthesia, sutures are not required, healing is quick, cosmetic outcome is usually excellent, costs are minimal, and complications are uncommon. The benefits of infant circumcision include prevention of urinary tract infections (a cause of renal scarring), reduction in risk of inflammatory foreskin conditions such as balanoposthitis, foreskin injuries, phimosis and paraphimosis. When the boy later becomes sexually active he has substantial protection against risk of HIV and other viral sexually transmitted infections such as genital herpes and oncogenic human papillomavirus, as well as penile cancer. The risk of cervical cancer in his female partner(s) is also reduced. Circumcision in adolescence or adulthood may evoke a fear of pain, penile damage or reduced sexual pleasure, even though unfounded. Time off work or school will be needed, cost is much greater, as are risks of complications, healing is slower, and stitches or tissue glue must be used. Summary Infant circumcision is safe, simple, convenient and cost-effective. The available evidence strongly supports infancy as the optimal time for circumcision. PMID:22373281

  19. Time-restricted feeding attenuates age-related cardiac decline in Drosophila

    PubMed Central

    Gill, Shubhroz; Le, Hiep D.; Melkani, Girish C.; Panda, Satchidananda

    2015-01-01

    Summary Circadian clocks orchestrate periods of rest or activity and feeding or fasting over the course of a 24 h day and maintain homeostasis. To assess whether a consolidated 24 h cycle of feeding and fasting can sustain health, we explored the effect of time-restricted feeding (TRF; food access limited to daytime 12 h every day) on neural, peripheral and cardiovascular physiology in Drosophila melanogaster. We detected improved sleep, prevention of body weight gain and deceleration of cardiac aging under TRF, even when caloric intake and expenditure were unchanged. We used temporal gene expression profiling and validation through classical genetics to identify the TCP-1 Ring Complex (TRiC) chaperonin, the mitochondrial electron transport chain complexes and the circadian clock as pathways mediating the benefits of TRF. PMID:25766238

  20. Photon dose rates from spent fuel assemblies with relation to self-protection (Rev. 1)

    SciTech Connect

    Pond, R.B.; Matos, J.E.

    1996-02-01

    Photon dose rates as a function of fission product decay times have been calculated for spent fuel assemblies typical of MTR-type research and test reactors. Based upon these dose rates, the length of time that a spent fuel assembly will be self-protecting (dose rate greater than 100 rem/h at 1 m in air) can be estimated knowing the mass of fuel burned, the fraction of fuel burned, and the fuel assembly specific power density.

  1. Release of quantum dot nanoparticles in porous media: role of cation exchange and aging time.

    PubMed

    Torkzaban, Saeed; Bradford, Scott A; Wan, Jiamin; Tokunaga, Tetsu; Masoudih, Arash

    2013-10-15

    Understanding the fate and transport of engineered nanoparticles (ENPs) in subsurface environments is required for developing the best strategy for waste management and disposal of these materials. In this study, the deposition and release of quantum dot (QD) nanoparticles were studied in saturated sand columns. The QDs were first deposited in columns using 100 mM NaCl or 2 mM CaC12 solutions. Deposited QDs were then contacted with deionized (DI) water and/or varying Na(+) concentrations to induce release. QDs deposited in 100 mM Na(+) were easily reversible when the column was rinsed with DI water. Conversely, QDs deposited in the presence of Ca(2+) exhibited resistance to release with DI water. However, significant release occurred when the columns were flushed with NaCl solutions. This release behavior was explained by cation exchange (Ca(2+) in exchange sites were replaced by Na(+)) which resulted in the breakdown of calcium bridging. We also studied the effect of aging time on the QD release. As the aging time increased, smaller amounts of QDs were released following cation exchange. However, deposited QDs were subsequently released when the column was flushed with DI water. The release behavior was modeled using a single first-order kinetic release process and changes in the maximum solid phase concentration of deposited QDs with transition in solution chemistry. The results of this study demonstrate that the presence of carboxyl groups on ENPs and divalent ions in the solution plays a key role in controlling ENP mobility in the subsurface environment.

  2. Spent Fuel Reprocessing: More Value for Money Spent in a Geological Repository?

    SciTech Connect

    Kaplan, P.; Vinoche, R.; Devezeaux, J-G.; Bailly, F.

    2003-02-25

    Today, each utility or country operating nuclear power plants can select between two long-term spent fuel management policies: either, spent fuel is considered as waste to dispose of through direct disposal or, spent fuel is considered a resource of valuable material through reprocessing-recycling. Reading and listening to what is said in the nuclear community, we understand that most people consider that the choice of policy is, actually, a choice among two technical paths to handle spent fuel: direct disposal versus reprocessing. This very simple situation has been recently challenged by analysis coming from countries where both policies are on survey. For example, ONDRAF of Belgium published an interesting study showing that, economically speaking for final disposal, it is worth treating spent fuel rather than dispose of it as a whole, even if there is no possibility to recycle the valuable part of it. So, the question is raised: is there such a one-to-one link between long term spent fuel management political option and industrial option? The purpose of the presentation is to discuss the potential advantages and drawbacks of spent fuel treatment as an implementation of the policy that considers spent fuel as waste to dispose of. Based on technical considerations and industrial experience, we will study qualitatively, and quantitatively when possible, the different answers proposed by treatment to the main concerns of spent-fuel-as-a-whole geological disposal.

  3. Application of isotopes to estimate water ages in variable time scales in surface and groundwaters

    NASA Astrophysics Data System (ADS)

    Kralik, Martin

    2014-05-01

    Water-Isotopes (2H, 3H, 18O) are ideal tracers not only to determine the origin of waters in precipitation, surface water (river + lakes) as well as in groundwater close to the surface and in deep groundwater but also the mean residence time (MRT) in many applied projects as drinking water supply, hydroelectric power plants, road tunnels etc. . Their application has a long history, but must be always evaluated by a feasible hydrogeological concept and/or other isotope and geochemical tracers. In Alpine areas the retention of precipitation in form of snow and ice in the winter half year is indicated by the lowest 18O-values. The snow melt of the highest part of the recharge area is marked by the lowest 18O-values in the river water, but may not coincide with the maximum flow. Time-series of precipitation station in the mountain and on river station indicate the arrival of the peak snow-melt water in the river and in Low-land areas 4-7 month later. Tritium series indicate that MRTs of several Austrian rivers are in the range of 4 - 6 years. The seasonal input variation of in 18O in precipitation and/or river waters can be used to calculate by lumped parameter models MRT of groundwater at a certain well and compare it with lysimeter measurements and transient model simulations. The MRT of the dispersion model is in good agreement with the estimated time calculated by the numerical transport model and the vertical lysimeter measurements. The MRT of spring water was studied by several methods (3H/3He, SF6 and 85Kr) and a long time series of 3H-measurements. The gas tracers are in good agreement in the range of 6-10 year whereas the 3H-series model (dispersion model) indicate ages in the range of 18-23 years. The hydrogeological concept indicate that the precipitation infiltrates in a mountainous karst area, but the transfer into the porous aquifer in the Vienna Basin occurs either through rivers draining away in the basin or through the lateral transport from the karst

  4. Use of spent substrate after Pleurotus pulmonarius cultivation for the treatment of chlorothalonil containing wastewater.

    PubMed

    Juárez, Rosa A Córdova; Dorry, Lilliam L Gordillo; Bello-Mendoza, Ricardo; Sánchez, José E

    2011-03-01

    Lignocellulosic materials are used as substrate for the cultivation of the edible mushroom Pleurotus pulmonarius. After two or three flushes of mushrooms, the spent substrate is discarded although it still has an important enzymatic activity that can be used for several purposes. In this study, we sought to determine the technical feasibility of using spent substrate from P. pulmonarius to degrade chlorothalonil. Reaction mixture was prepared with 6 ml of pesticide aqueous solution (2 mg active ingredient/l) and 3 ml of enzymatic extract obtained from spent P. pulmonarius substrate. The enzymatic reaction (27 °C, pH 7.4) was conducted for 1 h with sampling at 15 min intervals. The effect of storage time and temperature (freezing or refrigerating) of spent substrate and enzymatic extract, respectively, on the activity over chlorothalonil was determined. Freshly obtained spent substrate extract was able to reduce 100% of the initial concentration of chlorothalonil (2 mg/l) after 45 min of reaction. Storage time had a negative effect on the stability of the enzymatic activity: with spent substrate stored for a week, chlorothalonil concentration was reduced in 49.5% after 1 h reaction and with substrate stored for two and three weeks, the degradation efficiency decreased to 9.15% and 0%, respectively. Cooling and freezing the spent substrate extract also had a negative effect on chlorothalonil degradation.

  5. Future time perspective and awareness of age-related change: Examining their role in predicting psychological well-being.

    PubMed

    Brothers, Allyson; Gabrian, Martina; Wahl, Hans-Werner; Diehl, Manfred

    2016-09-01

    This study examined how 2 distinct facets of perceived personal lifetime-future time perspective (FTP) and awareness of age-related change (AARC)-are associated with another, and how they may interact to predict psychological well-being. To better understand associations among subjective perceptions of lifetime, aging, and well-being, we tested a series of models to investigate questions of directionality, indirect effects, and conditional processes among FTP, AARC-Gains, AARC-Losses, and psychological well-being. In all models, we tested for differences between middle-aged and older adults, and between adults from the United States and Germany. Analyses were conducted within a structural equation modeling framework on a cross-national, 2.5-year longitudinal sample of 537 community-residing adults (age 40-98 years). Awareness of age-related losses (AARC-Losses) at Time 1 predicted FTP at Time 2, but FTP did not predict AARC-Gains or AARC-Losses. Furthermore, future time perspective mediated the association between AARC-Losses and well-being. Moderation analyses revealed a buffering effect of awareness of age-related gains (AARC-Gains) in which perceptions of more age-related gains diminished the negative effect of a limited future time perspective on well-being. Effects were robust across age groups and countries. Taken together, these findings suggest that perceived age-related loss experiences may sensitize individuals to perceive a more limited future lifetime which may then lead to lower psychological well-being. In contrast, perceived age-related gains may function as a resource to preserve psychological well-being, in particular when time is perceived as running out. (PsycINFO Database Record

  6. Longitudinal Reliability of Self-Reported Age at Menarche in Adolescent Girls: Variability across Time and Setting

    ERIC Educational Resources Information Center

    Dorn, Lorah D.; Sontag-Padilla, Lisa M.; Pabst, Stephanie; Tissot, Abbigail; Susman, Elizabeth J.

    2013-01-01

    Age at menarche is critical in research and clinical settings, yet there is a dearth of studies examining its reliability in adolescents. We examined age at menarche during adolescence, specifically, (a) average method reliability across 3 years, (b) test-retest reliability between time points and methods, (c) intraindividual variability of…

  7. Deposition times in the northeastern United States during the Holocene: establishing valid priors for Bayesian age models

    NASA Astrophysics Data System (ADS)

    Goring, S.; Williams, J. W.; Blois, J. L.; Jackson, S. T.; Paciorek, C. J.; Booth, R. K.; Marlon, J. R.; Blaauw, M.; Christen, J. A.

    2012-08-01

    Age-depth relationships in sedimentary archives such as lakes, wetlands and bogs are non-linear with irregular probability distributions associated with calibrated radiocarbon dates. Bayesian approaches are thus well-suited to understanding relationships between age and depth for use in paleoecological studies. Bayesian models for the accumulation of sediment and organic matter within basins combine dated material from one or more records with prior information about the behavior of deposition times (yr/cm) based on expert knowledge. Well-informed priors are essential to good modeling of the age-depth relationship, but are particularly important in cases where data may be sparse (e.g., few radiocarbon dates), or unclear (e.g., age-reversals, coincident dates, age offsets, outliers and dates within a radiocarbon plateau). Here we assessed Holocene deposition times using 204 age-depth models obtained from the Neotoma Paleoecology Database (www.neotomadb.org) for both lacustrine and palustrine environments across the northeastern United States. These age-depth models were augmented using biostratigraphic events identifiable within pollen records from the northeastern United States during the Holocene and late-Pleistocene. Deposition times are significantly related to depositional environment (palustrine and lacustrine), sediment age, and sediment depth. Spatial variables had non-significant relationships with deposition time when site effects were considered. The best-fit model was a generalized additive mixed model that relates deposition time to age, stratified by depositional environment with site as a random factor. The best-fit model accounts for 63.3% of the total deviance in deposition times. The strongly increasing accumulation rates of the last 500-1000 years indicate that gamma distributions describing lacustrine deposition times (α = 1.08, β = 18.28) and palustrine deposition times (α = 1.23, β = 22.32) for the entire Holocene may be insufficient for

  8. PWR and BWR spent fuel assembly gamma spectra measurements

    NASA Astrophysics Data System (ADS)

    Vaccaro, S.; Tobin, S. J.; Favalli, A.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Hu, J.; Schwalbach, P.; Sjöland, A.; Trellue, H.; Vo, D.

    2016-10-01

    A project to research the application of nondestructive assay (NDA) to spent fuel assemblies is underway. The research team comprises the European Atomic Energy Community (EURATOM), embodied by the European Commission, DG Energy, Directorate EURATOM Safeguards; the Swedish Nuclear Fuel and Waste Management Company (SKB); two universities; and several United States national laboratories. The Next Generation of Safeguards Initiative-Spent Fuel project team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. This study focuses on spectrally resolved gamma-ray measurements performed on a diverse set of 50 assemblies [25 pressurized water reactor (PWR) assemblies and 25 boiling water reactor (BWR) assemblies]; these same 50 assemblies will be measured with neutron-based NDA instruments and a full-length calorimeter. Given that encapsulation/repository and dry storage safeguards are the primarily intended applications, the analysis focused on the dominant gamma-ray lines of 137Cs, 154Eu, and 134Cs because these isotopes will be the primary gamma-ray emitters during the time frames of interest to these applications. This study addresses the impact on the measured passive gamma-ray signals due to the following factors: burnup, initial enrichment, cooling time, assembly type (eight different PWR and six different BWR fuel designs), presence of gadolinium rods, and anomalies in operating history. To compare the measured results with theory, a limited number of ORIGEN-ARP simulations were performed.

  9. PWR and BWR spent fuel assembly gamma spectra measurements

    SciTech Connect

    Vaccaro, S.; Tobin, Stephen J.; Favalli, Andrea; Grogan, Brandon R.; Jansson, Peter; Liljenfeldt, Henrik; Mozin, Vladimir; Hu, Jianwei; Schwalbach, P.; Sjoland, A.; Trellue, Holly; Vo, D.

    2016-07-17

    A project to research the application of nondestructive assay (NDA) to spent fuel assemblies is underway. The research team comprises the European Atomic Energy Community (EURATOM), embodied by the European Commission, DG Energy, Directorate EURATOM Safeguards; the Swedish Nuclear Fuel and Waste Management Company (SKB); two universities; and several United States national laboratories. The Next Generation of Safeguards Initiative–Spent Fuel project team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. This study focuses on spectrally resolved gamma-ray measurements performed on a diverse set of 50 assemblies [25 pressurized water reactor (PWR) assemblies and 25 boiling water reactor (BWR) assemblies]; these same 50 assemblies will be measured with neutron-based NDA instruments and a full-length calorimeter. Given that encapsulation/repository and dry storage safeguards are the primarily intended applications, the analysis focused on the dominant gamma-ray lines of 137Cs, 154Eu, and 134Cs because these isotopes will be the primary gamma-ray emitters during the time frames of interest to these applications. This study addresses the impact on the measured passive gamma-ray signals due to the following factors: burnup, initial enrichment, cooling time, assembly type (eight different PWR and six different BWR fuel designs), presence of gadolinium rods, and anomalies in operating history. As a result, to compare the measured results with theory, a limited number of ORIGEN-ARP simulations were performed.

  10. PWR and BWR spent fuel assembly gamma spectra measurements

    DOE PAGES

    Vaccaro, S.; Tobin, Stephen J.; Favalli, Andrea; ...

    2016-07-17

    A project to research the application of nondestructive assay (NDA) to spent fuel assemblies is underway. The research team comprises the European Atomic Energy Community (EURATOM), embodied by the European Commission, DG Energy, Directorate EURATOM Safeguards; the Swedish Nuclear Fuel and Waste Management Company (SKB); two universities; and several United States national laboratories. The Next Generation of Safeguards Initiative–Spent Fuel project team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detectmore » the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. This study focuses on spectrally resolved gamma-ray measurements performed on a diverse set of 50 assemblies [25 pressurized water reactor (PWR) assemblies and 25 boiling water reactor (BWR) assemblies]; these same 50 assemblies will be measured with neutron-based NDA instruments and a full-length calorimeter. Given that encapsulation/repository and dry storage safeguards are the primarily intended applications, the analysis focused on the dominant gamma-ray lines of 137Cs, 154Eu, and 134Cs because these isotopes will be the primary gamma-ray emitters during the time frames of interest to these applications. This study addresses the impact on the measured passive gamma-ray signals due to the following factors: burnup, initial enrichment, cooling time, assembly type (eight different PWR and six different BWR fuel designs), presence of gadolinium rods, and anomalies in operating history. As a result, to compare the measured results with theory, a limited number of ORIGEN-ARP simulations were performed.« less

  11. Effects of Aging-Time Reference on the Long Term Behavior of the IM7/K3B Composite

    NASA Technical Reports Server (NTRS)

    Veazie, David R.; Gates, Thomas S.

    1998-01-01

    An analytical study was undertaken to investigate the effects of the time-based shift reference on the long term behavior of the graphite reinforced thermoplastic polyimide composite IM7/K3B at elevated temperature. Creep compliance and the effects of physical aging on the time dependent response was measured for uniaxial loading at several isothermal conditions below the glass transition temperature (T(sub g). Two matrix dominated loading modes, shear and transverse, were investigated in tension and compression. The momentary sequenced creep/aging curves were collapsed through a horizontal (time) shift using the shortest, middle and longest aging time curve as the reference curve. Linear viscoelasticity was used to characterize the creep/recovery behavior and superposition techniques were used to establish the physical aging related material constants. The use of effective time expressions in a laminated plate model allowed for the prediction of long term creep compliance. The effect of using different reference curves with time/aging-time superposition was most sensitive to the physical aging shift rate at lower test temperatures. Depending on the loading mode, the reference curve used can result in a more accurate long term prediction, especially at lower test temperatures.

  12. [Which vaccination schedule, which vaccines? The constraints of time and age].

    PubMed

    Goujon, C

    1997-01-01

    Several factors must be taken into account in planning vaccination schedules for overseas travelers. The first factor is to determine requirements mandated by applicable laws in the destination country and in France governing professional travel such as by military personnel. The other factors involve risk assessment including local health and epidemiological conditions, living conditions during the stay, and personal profile of the traveler (e.g. age and previous vaccination). Tropical areas are not the only destinations where infectious risks requiring vaccinations are found. Vaccination against diseases such as diphtheria and tick-borne encephalitis is necessary for several countries in Europe. Pre-travel planning provides a timely opportunity for updating basic vaccination requirements (e.g. tetanus and polio). For the growing number of elderly travelers, accurate evaluation of immune status may be difficult either because these subjects may never been vaccinated but only exposed to the wild germ during childhood or because their vaccinations may have been performed long ago. In both cases one cannot be sure of the quality of the anamnestic response to booster injections. A frequent limitation on vaccination planning for travelers is time available before departure.

  13. The Domestication of Artichoke and Cardoon: From Roman Times to the Genomic Age

    PubMed Central

    Sonnante, Gabriella; Pignone, Domenico; Hammer, Karl

    2007-01-01

    Background The history of domestication of artichoke and leafy cardoon is not yet fully understood and when and where it occurred remains unknown. Evidence supports the hypothesis that wild cardoon is the wild progenitor of both these crops. Selection for large, non-spiny heads resulted in artichoke and selection for non-spiny, large stalked tender leaves resulted in leafy cardoon. The two crops differ in their reproductive system: artichoke is mostly vegetatively propagated and perennial, while leafy cardoon is seed propagated and mostly grown as an annual plant. Here, new trends in artichoke cultivation are analysed, while the consequences of these tendencies on the conservation of artichoke genetic resources are highlighted. Scope The historical and artistic records, together with recent literature on genetics and biosystematics, are examined with the aim of achieving a better understanding of the present-day knowledge on the domestication of these two crops. Conclusions Historical, linguistic and artistic records are consistent with genetic and biosystematic data and indicate that the domestication of artichoke and cardoon diverged at different times and in different places. Apparently, artichoke was domesticated in Roman times, possibly in Sicily, and spread by the Arabs during early Middle Ages. The cardoon was probably domesticated in the western Mediterranean in a later period. PMID:17611191

  14. Status of work at PNL supporting dry storage of spent fuel

    SciTech Connect

    Cunningham, M.E.; McKinnon, M.A.; Michener, T.E.; Thomas, L.E.; Thornhill, C.K.

    1992-01-01

    Three projects related to dry storage of light-water reactor spent fuel are being conducted at Pacific Northwest Laboratory. Performance testing of six dry storage systems (four metal casks and two concrete storage systems) has been completed and results compiled. Two computer codes for predicting spent fuel and storage system thermal performance, COBRA-SFS and HYDRA-II, have been developed and have been reviewed by the US Nuclear Regulatory Commission. Air oxidation testing of spent fuel was conducted from 1984 through 1990 to obtain data to support recommendations of temperature-time limits for air dry storage for periods up to 40 years.

  15. Microbial recovery of metals from spent catalysts

    SciTech Connect

    Sperl, P.L.; Sperl, G.T.

    1990-01-01

    The second quarter of 1990 was one of peripheral progress on the project of reclaiming molybdenum and nickel from spent coal liquefaction catalysts. We defined some important parameters for future research and we were able to clear up ambiguities in some of the past approaches and the problems uniquely associated with the ability of T. ferrooxidans to leach both Ni{sup ++} and molybdate from spent, alumina supported catalyst from the Wilsonville pilot project. We were also able to show the T. ferrooxidans was very sensitive to molybdate and extremely sensitive to tungstate, but showed relatively little sensitivity for the related elements chromate, vanadate and for the catalyst associated metal, Ni{sup ++}. There appears to be no negative synergistic effects between Ni{sup ++} and molybdate for growth, which bodies well for processes to reclaim both these metals from spent coal liquefaction catalysts. We have shown that T. ferrooxidans is indeed capable of leaching molybdate and Ni{sup ++} from spent catalysts if the catalyst is washed extensively with both an organic solvent such as tetrahydrofuran to remove the oily contaminants and an aqueous acidic medium to remove readily solubilized N{sup ++} and molybdate. It is possible to extract into an acidic medium enough molybdate from THF washed spent catalyst within 24 hr to completely inhibit the growth of all tested T. ferrooxidans strains. The stage is now set for the development of a molybdate tolerant strain to be used for actual leaching of the spent catalyst. We are currently seeking simpler ways of pretreating the raw spent catalyst in order to make it more amenable to microbial leaching and possibly produce an economic and feasible technology.

  16. Family Structure and the Timing of Transitions from 70 to 103 Years of Age.

    ERIC Educational Resources Information Center

    Johnson, Colleen L.; Troll, Lillian

    1996-01-01

    Using a cross-sectional analysis of 250 white individuals, 70-103 years of age, this article questions whether a vertical family structure is found with increasing age. Findings indicate, among other things, that at least until age 90 the proportion of individuals with a vertical family structure with four generations never exceeds the numbers of…

  17. Molten tin reprocessing of spent nuclear fuel elements

    DOEpatents

    Heckman, Richard A.

    1983-01-01

    A method and apparatus for reprocessing spent nuclear fuel is described. Within a containment vessel, a solid plug of tin and nitride precipitates supports a circulating bath of liquid tin therein. Spent nuclear fuel is immersed in the liquid tin under an atmosphere of nitrogen, resulting in the formation of nitride precipitates. The layer of liquid tin and nitride precipitates which interfaces the plug is solidified and integrated with the plug. Part of the plug is melted, removing nitride precipitates from the containment vessel, while a portion of the plug remains solidified to support the liquid tin and nitride precipitates remaining in the containment vessel. The process is practiced numerous times until substantially all of the precipitated nitrides are removed from the containment vessel.

  18. Isotopic Analysis of Spent Nuclear Fuel with an Ultra-High Rate HPGe Spectrometer

    SciTech Connect

    Fast, James E.; Glasgow, Brian D.; Rodriguez, Douglas C.; VanDevender, Brent A.; Wood, Lynn S.

    2014-06-06

    A longstanding challenge is the assay of spent nuclear fuel (SNF). Determining the isotopic content of SNF requires gamma-ray spectroscopy. PNNL has developed new digital filtering and analysis techniques to produce an ultra high-rate gamma-ray spectrometer from a standard coaxial high-purity germanium (HPGe) crystal. This ~40% efficient detector has been operated for SNF measurements at a throughput of about 400k gamma-ray counts per second (kcps) at an input rate of 1.3 Mcps. Optimized filtering algorithms preserve the spectroscopic capability of the system even at these high rates. This talk will present the results of a SNF measurement with aged SNF pellets at PNNL’s Radiochemical Processing Laboratory, first results with a FPGA front end processor capable of processing the data in real time, and the development path toward a multi-element system to assay fuel assemblies.

  19. The effect of sol aging time on Structural and Optical properties of sol gel ZnO doped Al

    NASA Astrophysics Data System (ADS)

    El Hallani, G.; Fazouan, N.; Liba, A.; Khuili, M.

    2016-10-01

    Currently the doped or undoped ZnO semiconductor is of great importance in the field of electronic and optoelectronic devices such as transparent conductors and optical windows of solar cells based on silicon. ZnO thin films are produced by several techniques such as sol-gel method which is a chemical technique usually dependent on solution conditions. However, the sol gel aging time is an important parameter, which can have a significant impact on the properties of thin films. In this work we studied the effect of aging times (0h, 24h, 48h, 72h, 1 week) of the precursor solution on the structural and optical properties of ZnO doped Al (3 at.%). Thin films prepared by spin coating on glass substrates were investigated. The X-ray diffraction (XRD) analysis shows that the ZnO doped Al (3 at.%) exhibit the hexagonal wurtzite structure with a preferential orientation along [002] direction. The shift of (002) peaks towards higher diffraction angles is observed with sol aging time and also, a variation of crystallite sizes and thickness of thin films are shown with increasing sol aging time. All films present an average optical transmittance around 90% in the visible range with some interference fringes indicating a relative smoothness of films. We note an increasing in transmittance level with sol aging time from 0h to 48h. We can conclude that the aging times of the precursor solution influences the structural and optical properties of studied thin films.

  20. Testing, time limits, and English learners: does age of school entry affect how quickly students can learn English?

    PubMed

    Conger, Dylan

    2009-06-01

    Using data on young English learners (EL) who enroll in the New York City public school system, I examine how long it takes students to become minimally proficient in English and how the time to proficiency differs for students by their age of school entry. Specifically, I follow four recent entry cohorts of ELs ages 5-10 and use discrete-time survival analysis to model the rate at which different age groups acquire proficiency. I find that approximately half of the students become proficient within three years after school entry and that younger students learn more quickly than older students. Age of entry differences are robust to controls for observed differences between age of entry groups in their economic and demographic characteristics, their disabilities, and the schools they attend. The results lend support to the theory that older students face developmental barriers to learning new languages quickly.

  1. Thermal analysis for a spent reactor fuel storage test in granite

    SciTech Connect

    Montan, D.N.

    1980-09-01

    A test is conducted in which spent fuel assemblies from an operating commercial nuclear power reactor are emplaced in the Climax granite at the US Department of Energy`s Nevada Test Site. In this generic test, 11 canisters of spent PWR fuel are emplaced vertically along with 6 electrical simulator canisters on 3 m centers, 4 m below the floor of a storage drift which is 420 m below the surface. Two adjacent parallel drifts contain electrical heaters, operated to simulate (in the vicinity of the storage drift) the temperature fields of a large repository. This test, planned for up to five years duration, uses fairly young fuel (2.5 years out of core) so that the thermal peak will occur during the time frame of the test and will not exceed the peak that would not occur until about 40 years of storage had older fuel (5 to 15 years out of core) been used. This paper describes the calculational techniques and summarizes the results of a large number of thermal calculations used in the concept, basic design and final design of the spent fuel test. The results of the preliminary calculations show the effects of spacing and spent fuel age. Either radiation or convection is sufficient to make the drifts much better thermal conductors than the rock that was removed to create them. The combination of radiation and convection causes the drift surfaces to be nearly isothermal even though the heat source is below the floor. With a nominal ventilation rate of 2 m{sup 3}/s and an ambient rock temperature of 23{sup 0}C, the maximum calculated rock temperature (near the center of the heat source) is about 100{sup 0}C while the maximum air temperature in the drift is around 40{sup 0}C. This ventilation (1 m{sup 3}/s through the main drift and 1/2 m{sup 3}/s through each of the side drifts) will remove about 1/3 of the heat generated during the first five years of storage.

  2. Short organic carbon turnover time and narrow 14C age spectra in early Holocene wetland paleosols

    NASA Astrophysics Data System (ADS)

    Vetter, Lael; Rosenheim, Brad E.; Fernandez, Alvaro; Törnqvist, Torbjörn E.

    2017-01-01

    Paleosols contain information about the rates of soil organic carbon turnover when the soil was actively forming. However, this temporal information is often difficult to interpret without tight stratigraphic control on the age of the paleosol. Here we apply ramped pyrolysis/oxidation (Ramped PyrOx) 14C analyses to evaluate age spectra of transgressive early Holocene paleosols from the Mississippi Delta in southeastern Louisiana, USA. We find 14C age spectra from soil organic matter (SOM) in both paleosols and overlying basal peats that represent variability in age that is close to, or only slightly greater than, analytical uncertainty of 14C measurements, despite different sources of carbon with likely disparate ages. Such age spectra have not previously been observed in the sedimentary record. Here they indicate vigorous soil carbon turnover prior to burial, which homogenized 14C ages within SOM across the entire thermochemical spectrum. The weighted bulk 14C ages from Ramped PyrOx of paleosols and overlying peats are identical within analytical and process-associated uncertainty, and corroborate 14C ages from charcoal fragments and plant macrofossils from the overlying peat. The youngest ages from Ramped PyrOx age spectra may also potentially be applied as chronometers for stratigraphic burial ages. Our results suggest rapid turnover (≪300 years) of carbon in these soils relative to input of allochthonous carbon, indicating that the 14C age of different soil components is decoupled from thermochemical stability and instead reflects vigorous turnover processes. The concurrence of paleosol and peat 14C ages also suggests that pedogenic processes were linked with the development of coastal marshes, and that the priming effect potentially masked the signal of allochthonous carbon inputs during sea level rise.

  3. Safeguards issues in spent fuel consolidation facilities

    SciTech Connect

    Belew, W.L.; Moran, B.W.

    1991-01-01

    In the nuclear power industry, the fuel assembly is the basic unit for nuclear material accountancy. The safeguards procedures for the spent fuel assemblies, therefore, are based on an item accountancy approach. When fuel consolidation occurs in at-reactor'' or away-from-reactor'' facilities, the fuel assemblies are disassembled and cease to be the basic unit containing nuclear material. Safeguards can no longer be based on item accountancy of fuel assemblies. The spent fuel pins containing plutonium are accessible, and the possibilities for diversion of spent fuel for clandestine reprocessing to recover the plutonium are increased. Thus, identifying the potential safeguards concerns created by operation of these facilities is necessary. Potential safeguards techniques to address these concerns also must be identified so facility designs may include the equipment and systems required to provide an acceptable level of assurance that the international safeguards objectives can be met when these facilities come on-line. The objectives of this report are (1) to identify the safeguards issues associated with operation of spent fuel consolidation facilities, (2) to provide a preliminary assessment of the assessment of the safeguards vulnerabilities introduced, and (3) to identify potential safeguards approaches that could meet international safeguards requirements. The safeguards aspects of spent fuel consolidation are addressed in several recent reports and papers. 11 refs., 3 figs., 3 tabs.

  4. Determination of Plutonium Content in Spent Fuel with Nondestructive Assay

    SciTech Connect

    Tobin, S. J.; Sandoval, N. P.; Fensin, M. L.; Lee, S. Y.; Ludewigt, Bernhard A.; Menlovea, H. O.; Quiter, B. J.; Rajasingume, A.; Schearf, M. A.; Smith, L. E.; Swinhoe, M. T.; Thompson, S. J.

    2009-06-30

    There are a variety of reasons for quantifying plutonium (Pu) in spent fuel such as independently verifying the Pu content declared by a regulated facility, making shipper/receiver mass declarations, and quantifying the input mass at a reprocessing facility. As part of the Next Generation Safeguards Initiative, NA-241 has recently funded a multilab/university collaboration to determine the elemental Pu mass in spent fuel assemblies. This research effort is anticipated to be a five year effort: the first part of which is a two years Monte Carlo modeling effort to integrate and down-select among 13 nondestructive assay (NDA) technologies, followed by one year for fabricating instruments and then two years for measuring spent fuel. This paper gives a brief overview of the approach being taken for the Monte Carlo research effort. In addition, preliminary results for the first NDA instrument studied in detail, delayed neutron detection, will be presented. In order to cost effectively and robustly model the performance of several NDA techniques, an"assembly library" was created that contains a diverse range of pressurized water reactor spent fuel assemblies (burnup, enrichment, cooling time) similar to that which exists in spent pools today and in the future, diversion scenarios that capture a range of possible rod removal options, spatial and isotopic detail needed to accurately quantify the capability of all the NDA techniques so as to enable integration. Integration is being designed into this study from the beginning since it is expected that the best performance will be obtained by combining a few NDA techniques. The performance of each instrument will be quantified for the full assembly library in three different media: air, water and borated water. In this paper the preliminary capability of delayed neutron detection will be quantified for the spent fuel library for all three media. The 13 NDA techniques being researched are the following: Delayed Gamma, Delayed

  5. Ngram time series model to predict activity type and energy cost from wrist, hip and ankle accelerometers: implications of age.

    PubMed

    Strath, Scott J; Kate, Rohit J; Keenan, Kevin G; Welch, Whitney A; Swartz, Ann M

    2015-11-01

    To develop and test time series single site and multi-site placement models, we used wrist, hip and ankle processed accelerometer data to estimate energy cost and type of physical activity in adults. Ninety-nine subjects in three age groups (18-39, 40-64, 65 +  years) performed 11 activities while wearing three triaxial accelereometers: one each on the non-dominant wrist, hip, and ankle. During each activity net oxygen cost (METs) was assessed. The time series of accelerometer signals were represented in terms of uniformly discretized values called bins. Support Vector Machine was used for activity classification with bins and every pair of bins used as features. Bagged decision tree regression was used for net metabolic cost prediction. To evaluate model performance we employed the jackknife leave-one-out cross validation method. Single accelerometer and multi-accelerometer site model estimates across and within age group revealed similar accuracy, with a bias range of -0.03 to 0.01 METs, bias percent of -0.8 to 0.3%, and a rMSE range of 0.81-1.04 METs. Multi-site accelerometer location models improved activity type classification over single site location models from a low of 69.3% to a maximum of 92.8% accuracy. For each accelerometer site location model, or combined site location model, percent accuracy classification decreased as a function of age group, or when young age groups models were generalized to older age groups. Specific age group models on average performed better than when all age groups were combined. A time series computation show promising results for predicting energy cost and activity type. Differences in prediction across age group, a lack of generalizability across age groups, and that age group specific models perform better than when all ages are combined needs to be considered as analytic calibration procedures to detect energy cost and type are further developed.

  6. Ngram time series model to predict activity type and energy cost from wrist, hip and ankle accelerometers: implications of age

    PubMed Central

    Strath, Scott J; Kate, Rohit J; Keenan, Kevin G; Welch, Whitney A; Swartz, Ann M

    2016-01-01

    To develop and test time series single site and multi-site placement models, we used wrist, hip and ankle processed accelerometer data to estimate energy cost and type of physical activity in adults. Ninety-nine subjects in three age groups (18–39, 40–64, 65 + years) performed 11 activities while wearing three triaxial accelereometers: one each on the non-dominant wrist, hip, and ankle. During each activity net oxygen cost (METs) was assessed. The time series of accelerometer signals were represented in terms of uniformly discretized values called bins. Support Vector Machine was used for activity classification with bins and every pair of bins used as features. Bagged decision tree regression was used for net metabolic cost prediction. To evaluate model performance we employed the jackknife leave-one-out cross validation method. Single accelerometer and multi-accelerometer site model estimates across and within age group revealed similar accuracy, with a bias range of −0.03 to 0.01 METs, bias percent of −0.8 to 0.3%, and a rMSE range of 0.81–1.04 METs. Multi-site accelerometer location models improved activity type classification over single site location models from a low of 69.3% to a maximum of 92.8% accuracy. For each accelerometer site location model, or combined site location model, percent accuracy classification decreased as a function of age group, or when young age groups models were generalized to older age groups. Specific age group models on average performed better than when all age groups were combined. A time series computation show promising results for predicting energy cost and activity type. Differences in prediction across age group, a lack of generalizability across age groups, and that age group specific models perform better than when all ages are combined needs to be considered as analytic calibration procedures to detect energy cost and type are further developed. PMID:26449155

  7. Antioxidant and genoprotective effects of spent coffee extracts in human cells.

    PubMed

    Bravo, Jimena; Arbillaga, Leire; de Peña, M Paz; Cid, Concepcion

    2013-10-01

    Spent coffee has been shown as a good source of hydrophilic antioxidant compounds. The ability of two spent coffee extracts rich in caffeoylquinic acids, mainly dicaffeoylquinic acids, and caffeine (Arabica filter and Robusta espresso) to protect against oxidation and DNA damage in human cells (HeLa) was evaluated at short (2 h) and long (24 h) exposure times. Cell viability (MTT) was not affected by spent coffee extracts (>80%) up to 1000 μg/mL after 2 h. Both spent coffee extracts significantly reduced the increase of ROS level and DNA strand breaks (29-73% protection by comet assay) induced by H₂O₂. Pretreatment of cells with robusta spent coffee extract also decreased Ro photosensitizer-induced oxidative DNA damage after 24 h exposure. The higher effectiveness of Robusta spent coffee extract, with less caffeoylquinic acids and melanoidins, might be due to other antioxidant compounds, such as caffeine and other Maillard reaction products. This work evidences the potential antioxidant and genoprotective properties of spent coffee in human cells.

  8. Macro-level Age Norms for the Timing of Sexual Initiation and Adolescents’ Early Sexual Initiation in 17 European Countries

    PubMed Central

    Madkour, Aubrey Spriggs; de Looze, Margaretha; Ma, Ping; Halpern, Carolyn Tucker; Farhat, Tilda; ter Bogt, Tom F. M.; Ehlinger, Virginie; Nic Gabhainn, Saoirse; Currie, Candace; Godeau, Emmanuelle

    2014-01-01

    Purpose To examine the relationship between country-level age norms for sexual initiation timing and early sexual initiation (ESI) among adolescent boys and girls. Methods Nationally-representative data from 17 countries that participated in the 2006/07 European Social Survey (ESS-3, n=33,092) and the 2005/06 Health Behaviour in School-Aged Children Study (HBSC, n=27,702) were analyzed. Age norms were measured as the average country-level response to an item asking the age at which ESS respondents believed someone is too young to have sexual intercourse. HBSC respondents (aged 14-16) self-reported age at sexual initiation which we defined as early (<15 years) or not (≥15 years or no initiation). Control variables included age, family affluence, perceived socioeconomic status, family living arrangement, substance use, school attachment, and country-level legal age of consent. Multivariable three-level logistic models with random intercepts were run separately by sex. Results In multivariable analyses, higher overall age norms were associated with reduced likelihood of ESI among girls (AOR 0.60, 95% CI 0.45-0.79); associations with ESI were stronger for parent cohort (ages 31-65) norms (AOR 0.37, 95% CI 0.23-0.58) than for peer cohort (ages 15-20) norms (AOR 0.60, 95% CI 0.49-0.74). For boys, overall norms were also significantly negatively associated with ESI (AOR 0.68, 95% CI 0.46-0.99), as were parent cohort norms (AOR 0.66, 95% CI 0.45-0.96). Peer cohort norms were not significantly related to boys’ ESI. Conclusion Macro-level cultural norms may impact adolescents’ sexual initiation timing. Research exploring the sexual health outcomes of early initiators in countries with contrasting age norms is warranted. PMID:24508092

  9. High Precision Ar/Ar Ages of Coso Volcanic Field Rhyolites: A Requirement for Constraining Eruption and Subvolcanic Time Scales

    NASA Astrophysics Data System (ADS)

    Simon, J. I.; Renne, P. R.; Vazquez, J.

    2006-12-01

    Study of the extended volcanic history and petrology at Coso Volcanic Field, CA has led to fundamental ideas related to silicic magma evolution and eruption prediction. Unfortunately, tests of these and related models for the time scales of subvolcanic processes at Coso are limited because relatively few modern geochronological constraints have been published. For example, tighter age constraints are needed to test the veracity of the volume-age "time-prediction" model of Bacon (1982) wherein the next eruption can be predicted reasonably well from a long-term eruption rate that simply considers the total volume of Coso rhyolites over an appropriate time span. At Coso, reported eruption events are mean ages comprising K-Ar ± hydration rind glass ages grouped by rock chemical similarities. Here we present new Ar/Ar ages for seven Pleistocene domes from groups 4, 6, and 7. Sanidine and anorthoclase were separated from nearly aphyric obsidian and pumiceous glasses. Total fusion and step-heating feldspar and glass analyses were performed. Ar/Ar spectra derived from laser step-heating of samples from previously dated domes show that excess 40Ar contamination likely biased some K-Ar results. Modern Ar/Ar analyses of the studied rhyolites with disturbed model (i.e., assuming atmospheric initial Ar) ages, but well-defined Ar isochrons still provide accurate eruption ages. In detail, a 229 ±6 ka (2 se) age is determined for the most northern dome, which is ~60 ka older than one reported K-Ar date and the nominal age for Group 4 rhyolites and ~150-370 ka younger than four other reported K-Ar dates. Based on pre-eruption zircon ages from other magma centers, the inaccuracies and magnitude of these age shifts could produce apparent magma residence times from ≥500 ka to meaningless futuristic storage times. New ages for the southern domes are older than the reported mean Group 6 age of ~90 ka. It is probable that the anomalously young K-Ar dates reflect incomplete extraction

  10. The Time of Our Lives: Recognizing the Contributions of Mannheim, Neugarten, and Riley to the Study of Aging

    PubMed Central

    Ferraro, Kenneth F.

    2014-01-01

    Time is central to the study of aging, but multiple dimensions of time, especially its subjective sense, merit more systematic attention in gerontology. This essay honors the intellectual legacy of Karl Mannheim, Bernice Neugarten, Matilda Riley, and others for drawing attention to the social dimensions of time relevant for the scientific study of aging. I summarize major contributions of these social scientists for the study of aging and note points of overlap and distinction. Although their writings have led gerontologists to think more systematically about life course timing and trajectories, there is relatively little empirical research on temporal perceptions in such trajectories and the interplay of objective and subjective elements of time. PMID:23708128

  11. Chill-coma recovery time, age and sex determine lipid profiles in Ceratitis capitata tissues.

    PubMed

    Pujol-Lereis, Luciana Mercedes; Fagali, Natalia Soledad; Rabossi, Alejandro; Catalá, Ángel; Quesada-Allué, Luis Alberto

    2016-04-01

    The remodeling of membrane composition by changes in phospholipid head groups and fatty acids (FA) degree of unsaturation has been associated with the maintenance of membrane homeostasis under stress conditions. Overall lipid levels and the composition of cuticle lipids also influence insect stress resistance and tissue protection. In a previous study, we demonstrated differences in survival, behavior and Cu/Zn superoxide dismutase gene expression between subgroups of Ceratitis capitata flies that had a reversible recovery from chill-coma and those that developed chilling-injury. Here, we analyzed lipid profiles from comparable subgroups of 15 and 30-day-old flies separated according to their recovery time after a chill-coma treatment. Neutral and polar lipid classes of chill-coma subgroups were separated by thin layer chromatography and quantified by densitometry. FA composition of polar lipids of chill-coma subgroups and non-stressed flies was evaluated using gas chromatography coupled to mass spectrometry. Higher amounts of neutral lipids such as triglycerides, diacylglycerol, wax esters, sterol esters and free esters were found in male flies that recovered faster from chill-coma compared to slower flies. A multivariate analysis revealed changes in patterns of storage and cuticle lipids among subgroups both in males and females. FA unsaturation increased after cold exposure, and was higher in thorax of slower subgroups compared to faster subgroups. The changes in neutral lipid patterns and FA composition depended on recovery time, sex, age and body-part, and were not specifically associated with the development of chilling-injury. An analysis of phospholipid classes showed that the phosphatidylcholine to lysophosphatidylcholine ratio (PC/LPC) was significantly higher, or showed a tendency, in subgroups that may have developed chilling-injury compared to those with a reversible recovery from coma.

  12. Nest survival patterns in Eurasian Bittern: effect of nest age, time and habitat variables.

    PubMed

    Polak, Marcin

    2016-01-01

    Determining the key factors affecting the reproductive success of nesting birds is crucial in order to better understand the population dynamics of endangered species and to introduce effective conservation programmes for them. Inhabiting a variety of wetland habitats, aquatic birds actively select safe nesting sites so as to protect their nests against predators. The main aim of the present work was to assess the effect of temporal and habitat variables on the daily nest survival rate of Eurasian Bitterns colonizing semi-natural fishpond habitat in eastern Poland. MARK software was used for the modelling. Eurasian Bittern nests were most vulnerable to depredation at the beginning of the breeding season. This was probably because the reedbed vegetation at this time was not yet dense enough to effectively conceal the nests. There was a positive relationship between nest age and the daily survival rate. Two of the habitat variables analysed were of the greatest significance: water depth and vegetation density. In the Eurasian Bittern population studied here, nests built over deep water and in dense vegetation had the best chances of survival. The results of this work may be useful in the preparation of plans for the conservation and management of populations of this rare and endangered species. Conservation and restoration efforts that attempt to maintain high water levels will be especially beneficial to this avian species that is dependent on wetland ecosystems for breeding.

  13. Young driver accidents in the UK: the influence of age, experience, and time of day.

    PubMed

    Clarke, David D; Ward, Patrick; Bartle, Craig; Truman, Wendy

    2006-09-01

    Young drivers, especially males, have relatively more accidents than other drivers. Young driver accidents also have somewhat different characteristics to those of other drivers; they include single vehicle accidents involving loss of control; excess speed for conditions; accidents during darkness; accidents on single carriageway rural roads; and accidents while making cross-flow turns (i.e. turning right in the UK, equivalent to a left turn in the US and continental Europe). A sample of over 3000 accident cases was considered from midland British police forces, involving drivers aged 17-25 years, and covering a two year period. Four types of accident were analysed: right-turns; rear-end shunts; loss of control on curves; and accidents in darkness. Loss of control on curves and accidents in darkness were found to be a particular problem for younger drivers. It was found that cross-flow turn accidents showed the quickest improvement with increasing driver experience, whereas accidents occurring in darkness with no street lighting showed the slowest rate of improvement. 'Time of day' analyses suggested that the problems of accidents in darkness are not a matter of visibility, but a consequence of the way young drivers use the roads at night. There appears to be a large number of accidents associated with voluntary risk-taking behaviours of young drivers in 'recreational' driving.

  14. Nest survival patterns in Eurasian Bittern: effect of nest age, time and habitat variables

    PubMed Central

    2016-01-01

    Determining the key factors affecting the reproductive success of nesting birds is crucial in order to better understand the population dynamics of endangered species and to introduce effective conservation programmes for them. Inhabiting a variety of wetland habitats, aquatic birds actively select safe nesting sites so as to protect their nests against predators. The main aim of the present work was to assess the effect of temporal and habitat variables on the daily nest survival rate of Eurasian Bitterns colonizing semi–natural fishpond habitat in eastern Poland. MARK software was used for the modelling. Eurasian Bittern nests were most vulnerable to depredation at the beginning of the breeding season. This was probably because the reedbed vegetation at this time was not yet dense enough to effectively conceal the nests. There was a positive relationship between nest age and the daily survival rate. Two of the habitat variables analysed were of the greatest significance: water depth and vegetation density. In the Eurasian Bittern population studied here, nests built over deep water and in dense vegetation had the best chances of survival. The results of this work may be useful in the preparation of plans for the conservation and management of populations of this rare and endangered species. Conservation and restoration efforts that attempt to maintain high water levels will be especially beneficial to this avian species that is dependent on wetland ecosystems for breeding. PMID:27350897

  15. Modafinil improves attention, inhibitory control, and reaction time in healthy, middle-aged rats.

    PubMed

    Morgan, Russell E; Crowley, Jaime M; Smith, Roland H; LaRoche, Ronee B; Dopheide, Marsha M

    2007-03-01

    This study examined the effect of the novel psychostimulant modafinil (Provigil) on a variety of cognitive and behavioral measures including associative learning, sustained attention, inhibitory control, and reaction time. Middle-aged female rats (18-20 months old) were administered oral doses of modafinil (0, 8, 32, and 64 mg/kg) and tested in a 3-choice visual discrimination and sustained attention task. Modafinil produced a dose-dependent pattern of improved response accuracy and impulse control (fewer premature responses) and shorter response latencies, without affecting omission errors, motivation or motor control. Although the biochemical mechanism of modafinil is unknown, these results suggest a profile differing from typical psychostimulants (e.g., amphetamine). The implications of these findings for treatment of narcolepsy, ADHD, and various arousal-related disorders are considered. Further research is needed to examine the relative safety, effectiveness, and addictive potential of modafinil, as well as, its effects in comparison with other performance-enhancing drugs (e.g., caffeine, nicotine, and amphetamines).

  16. Resiliency Over Time of Elders’ Age Stereotypes After Encountering Stressful Events

    PubMed Central

    Slade, Martin D.; Chung, Pil H.; Gill, Thomas M.

    2015-01-01

    Objective. To examine whether the age stereotypes of older individuals would become more negative or else show resiliency following stressful events and to examine whether age-stereotype negativity would increase the likelihood of experiencing a stressful event (i.e., hospitalization). Method. Age stereotypes of 231 participants, 70 years and older, were assessed across 10 years, before and after the occurrence of hospitalizations and bereavements. Results. Age-stereotype negativity was resilient despite encountering stressful events. In contrast, more negative age stereotypes were associated with a 50% greater likelihood of experiencing a hospitalization. Discussion. The robustness of negative age stereotypes was expressed in their capacity to resist change as well as generate it. PMID:24997287

  17. Spent Nuclear Fuel Alternative Technology Decision Analysis

    SciTech Connect

    Shedrow, C.B.

    1999-11-29

    The Westinghouse Savannah River Company (WSRC) made a FY98 commitment to the Department of Energy (DOE) to recommend a technology for the disposal of aluminum-based spent nuclear fuel (SNF) at the Savannah River Site (SRS). The two technologies being considered, direct co-disposal and melt and dilute, had been previously selected from a group of eleven potential SNF management technologies by the Research Reactor Spent Nuclear Fuel Task Team chartered by the DOE''s Office of Spent Fuel Management. To meet this commitment, WSRC organized the SNF Alternative Technology Program to further develop the direct co-disposal and melt and dilute technologies and ultimately provide a WSRC recommendation to DOE on a preferred SNF alternative management technology.

  18. B cells in the aging immune system: time to consider B-1 cells.

    PubMed

    Holodick, Nichol E; Rothstein, Thomas L

    2015-12-01

    The investigation of immune senescence has uncovered many changes in B cell development, maintenance, and function with increasing age. However, most of these studies have focused on conventional B cell subsets in the spleen. The B-1 cell subset is an essential arm of the innate immune system, which in general has been understudied in terms of immune senescence. Here, we review what is currently known about B cells during aging and go on to describe why B-1 cell biology is an important component of the aging immune system in the context of diseases that most affect the aged population.

  19. Early discrimination of Atlantic salmon smolt age: Time course of the relative effectiveness of body size and shape

    USGS Publications Warehouse

    Pearlstein, J.H.; Letcher, B.H.; Obedzinski, M.

    2007-01-01

    The goal of this study was to test the relative effectiveness of morphological measurements and body size in predicting the smolt age of Atlantic salmon Salmo salar and to determine the time course of body size and shape differences between smolt ages. Analyses were conducted on age-0 to age-2 fish that were stocked as fry in the West Brook, Massachusetts and on laboratory-raised age-0 to age-1 fish. Using both body size and shape, we could partition the age-0 fish collected during fall into future early or late smolts, although the predictive ability of body shape was somewhat weaker than that of body size, especially in the laboratory. Classification success averaged 81% (size) and 79% (shape) in the field and 85% (size) and 73% (shape) in the laboratory. Despite differences in smolt age between the field and the laboratory, the relative timing of growth rate differences between future early and late smolts was similar in the field and the laboratory and peaked at 50-60% of development from fry to smolt. While body shape differed between early and late smolts well before smoltification, it did not improve classification based on size alone.

  20. Method for shearing spent nuclear fuel assemblies

    DOEpatents

    Weil, Bradley S.; Watson, Clyde D.

    1977-01-01

    A method is disclosed for shearing spent nuclear fuel assemblies of the type wherein a plurality of long metal tubes packed with ceramic fuel are supported in a spaced apart relationship within an outer metal shell or shroud which provides structural support to the assembly. Spent nuclear fuel assemblies are first compacted in a stepwise manner between specially designed gag-compactors and then sheared into short segments amenable to chemical processing by shear blades contoured to mate with the compacted surface of the fuel assembly.

  1. Spent Fuel Background Report Volume I

    SciTech Connect

    Abbott, D.

    1994-03-01

    This report is an overview of current spent nuclear fuel management in the DOE complex. Sources of information include published literature, internal DOE documents, interviews with site personnel, and information provided by individual sites. Much of the specific information on facilities and fuels was provided by the DOE sites in response to the questionnaire for data for spent fuels and facilities data bases. This information is as accurate as is currently available, but is subject to revision pending results of further data calls. Spent fuel is broadly classified into three categories: (a) production fuels, (b) special fuels, and (c) naval fuels. Production fuels, comprising about 80% of the total inventory, are those used at Hanford and Savannah River to produce nuclear materials for defense. Special fuels are those used in a wide variety of research, development, and testing activities. Special fuels include fuel from DOE and commercial reactors used in research activities at DOE sites. Naval fuels are those developed and used for nuclear-powered naval vessels and for related research and development. Given the recent DOE decision to curtail reprocessing, the topic of main concern in the management of spent fuel is its storage. Of the DOE sites that have spent nuclear fuel, the vast majority is located at three sites-Hanford, INEL, and Savannah River. Other sites with spent fuel include Oak Ridge, West Valley, Brookhaven, Argonne, Los Alamos, and Sandia. B&W NESI Lynchburg Technology Center and General Atomics are commercial facilities with DOE fuel. DOE may also receive fuel from foreign research reactors, university reactors, and other commercial and government research reactors. Most DOE spent fuel is stored in water-filled pools at the reactor facilities. Currently an engineering study is being performed to determine the feasibility of using dry storage for DOE-owned spent fuel currently stored at various facilities. Delays in opening the deep geologic

  2. Spent Nuclear Fuel Transport Reliability Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao

    2016-01-01

    This conference paper was orignated and shorten from the following publisehd PTS documents: 1. Jy-An Wang, Hao Jiang, and Hong Wang, Dynamic Deformation Simulation of Spent Nuclear Fuel Assembly and CIRFT Deformation Sensor Stability Investigation, ORNL/SPR-2015/662, November 2015. 2. Jy-An Wang, Hong Wang, Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications, NUREG/CR-7198, ORNL/TM-2014/214, May 2015. 3. Jy-An Wang, Hong Wang, Hao Jiang, Yong Yan, Bruce Bevard, Spent Nuclear Fuel Vibration Integrity Study 16332, WM2016 Conference, March 6 10, 2016, Phoenix, Arizona.

  3. Apparatus for shearing spent nuclear fuel assemblies

    DOEpatents

    Weil, Bradley S.; Metz, III, Curtis F.

    1980-01-01

    A method and apparatus are described for shearing spent nuclear fuel assemblies of the type comprising an array of fuel pins disposed within an outer metal shell or shroud. A spent fuel assembly is first compacted in a known manner and then incrementally sheared using fixed and movable shear blades having matched laterally projecting teeth which slidably intermesh to provide the desired shearing action. Incremental advancement of the fuel assembly after each shear cycle is limited to a distance corresponding to the lateral projection of the teeth to ensure fuel assembly breakup into small uniform segments which are amenable to remote chemical processing.

  4. Spent brewer's yeast extract as an ingredient in cooked hams.

    PubMed

    Pancrazio, Gaston; Cunha, Sara C; de Pinho, Paula Guedes; Loureiro, Mónica; Meireles, Sónia; Ferreira, Isabel M P L V O; Pinho, Olívia

    2016-11-01

    This work describes the effect of the incorporation of 1% spent yeast extract into cooked hams. Physical/chemical/sensorial characteristics and changes during 12 and 90days storage were evaluated on control and treated cooked hams processed for 1.5, 2.0, 2.5 or 3h. Spent yeast extract addition increased hardness, chewiness, ash, protein and free amino acid content. Similar volatile profiles were obtained, although there were some quantitative differences. No advantages were observed for increased cooking time. No significant differences were observed for physical and sensorial parameters of cooked hams with spent yeast extract at 12 and 90days post production, but His, aldehydes and esters increased at the end of storage. This behaviour was similar to that observed for control hams. The higher hardness of cooked ham with 1% yeast extract was due to the stronger gel formed during cooking and was maintained during storage. This additive acts as gel stabilizer for cooked ham production and could potentially improve other processing characteristics.

  5. Naval Spent Nuclear Fuel disposal Container System Description Document

    SciTech Connect

    N. E. Pettit

    2001-07-13

    The Naval Spent Nuclear Fuel Disposal Container System supports the confinement and isolation of waste within the Engineered Barrier System of the Monitored Geologic Repository (MGR). Disposal containers/waste packages are loaded and sealed in the surface waste handling facilities, transferred underground through the access drifts using a rail mounted transporter, and emplaced in emplacement drifts. The Naval Spent Nuclear Fuel Disposal Container System provides long term confinement of the naval spent nuclear fuel (SNF) placed within the disposal containers, and withstands the loading, transfer, emplacement, and retrieval operations. The Naval Spent Nuclear Fuel Disposal Container System provides containment of waste for a designated period of time and limits radionuclide release thereafter. The waste package maintains the waste in a designated configuration, withstands maximum credible handling and rockfall loads, limits the waste form temperature after emplacement, resists corrosion in the expected handling and repository environments, and provides containment of waste in the event of an accident. Each naval SNF disposal container will hold a single naval SNF canister. There will be approximately 300 naval SNF canisters, composed of long and short canisters. The disposal container will include outer and inner cylinder walls and lids. An exterior label will provide a means by which to identify a disposal container and its contents. Different materials will be selected for the waste package inner and outer cylinders. The two metal cylinders, in combination with the Emplacement Drift System, drip shield, and the natural barrier will support the design philosophy of defense-in-depth. The use of materials with different properties prevents a single mode failure from breaching the waste package. The inner cylinder and inner cylinder lids will be constructed of stainless steel while the outer cylinder and outer cylinder lids will be made of high-nickel alloy.

  6. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    PubMed

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment.

  7. Age-related increases in right frontal activation during task switching are mediated by reaction time and white matter microstructure.

    PubMed

    Zhu, Z; Hakun, J G; Johnson, N F; Gold, B T

    2014-10-10

    Age-related increases in right frontal cortex activation are a common finding in the neuroimaging literature. However, neurocognitive factors contributing to right frontal over-recruitment remain poorly understood. Here we investigated the influence of age-related reaction time (RT) slowing and white matter (WM) microstructure reductions as potential explanatory factors for age-related increases in right frontal activation during task switching. Groups of younger (N=32) and older (N=33) participants completed a task switching paradigm while functional magnetic resonance imaging (fMRI) was performed, and rested while diffusion tensor imaging (DTI) was performed. Two right frontal regions of interest (ROIs), the dorsolateral prefrontal cortex (DLPFC) and insula, were selected for further analyses from a common network of regions recruited by both age groups during task switching. Results demonstrated age-related activation increases in both ROIs. In addition, the older adult group showed longer RT and decreased fractional anisotropy in regions of the corpus callosum with direct connections to the fMRI ROIs. Subsequent mediation analyses indicated that age-related increases in right insula activation were mediated by RT slowing and age-related increases in right DLPFC activation were mediated by WM microstructure. Our results suggest that age-related RT slowing and WM microstructure declines contribute to age-related increases in right frontal activation during cognitive task performance.

  8. 5 CFR 831.672 - Annuity for a child age 18 to 22 during full-time school attendance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... full-time school attendance. 831.672 Section 831.672 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) RETIREMENT Survivor Annuities Children's Annuities § 831.672 Annuity for a child age 18 to 22 during full-time school attendance. (a)...

  9. Age Differences in Negative Emotional Responses to Daily Stressors Depend on Time since Event

    ERIC Educational Resources Information Center

    Scott, Stacey B.; Ram, Nilam; Smyth, Joshua M.; Almeida, David M.; Sliwinski, Martin J.

    2017-01-01

    Research on age differences in the experience of negative emotional states have produced inconsistent results, particularly when emotion is examined in the context of daily stress. Strength and vulnerability integration (SAVI; Charles, 2010) theory postulates that age differences in emotional states are contingent upon whether a stressor occurred,…

  10. Older Men's Lay Definitions of Successful Aging over Time: The Manitoba Follow-Up Study

    ERIC Educational Resources Information Center

    Tate, Robert B.; Swift, Audrey U.; Bayomi, Dennis J.

    2013-01-01

    The concept of "successful aging" has become widely accepted in gerontology, yet continues to have no common underlying definition. Researchers have increasingly looked to older individuals for their lay definitions of successful aging. The present analysis is based on responses to five questionnaires administered to surviving…

  11. When Timing Is Everything: Age of First-Language Acquisition Effects on Second-Language Learning

    ERIC Educational Resources Information Center

    Mayberry, Rachel I.

    2007-01-01

    The present paper summarizes three experiments that investigate the effects of age of acquisition on first-language (L1) acquisition in relation to second-language (L2) outcome. The experiments use the unique acquisition situations of childhood deafness and sign language. The key factors controlled across the studies are age of L1 acquisition, the…

  12. Aging in Place: Evolution of a Research Topic Whose Time Has Come

    PubMed Central

    Vasunilashorn, Sarinnapha; Steinman, Bernard A.; Liebig, Phoebe S.; Pynoos, Jon

    2012-01-01

    Over the past 30 years, policy makers and professionals who provide services to older adults with chronic conditions and impairments have placed greater emphasis on conceptualizing aging in place as an attainable and worthwhile goal. Little is known, however, of the changes in how this concept has evolved in aging research. To track trends in aging in place, we examined scholarly articles published from 1980 to 2010 that included the concept in eleven academic gerontology journals. We report an increase in the absolute number and proportion of aging-in-place manuscripts published during this period, with marked growth in the 2000s. Topics related to the environment and services were the most commonly examined during 2000–2010 (35% and 31%, resp.), with a substantial increase in manuscripts pertaining to technology and health/functioning. This underscores the increase in diversity of topics that surround the concept of aging-in-place literature in gerontological research. PMID:22175020

  13. Shippingport Spent Fuel Canister System Description

    SciTech Connect

    JOHNSON, D.M.

    2001-06-26

    In 1978 and 1979, a total of 72 blanket fuel assemblies (BFAs), irradiated during the operating cycles of the Shippingport Atomic Power Station's Pressurized Water Reactor (PWR) Core 2 from April 1965 to February 1974, were transferred to the Hanford Site and stored in underwater storage racks in Cell 2R at the 221-T Canyon (T-Plant). The initial objective was to recover the produced plutonium in the BFAs, but this never occurred and the fuel assemblies have remained within the water storage pool to the present time. The Shippingport Spent Fuel Canister (SSFC) is a confinement system that provides safe transport functions (in conjunction with the TN-WHC cask) and storage for the BFAs at the Canister Storage Building (CSB). The current plan is for these BFAs to be retrieved from wet storage and loaded into SSFCs for dry storage. The sealed SSFCs containing BFAs will be vacuum dried, internally backfilled with helium, and leak tested to provide suitable confinement for the BFAs during transport and storage. Following completion of the drying and inerting process, the SSFCs are to be delivered to the CSB for closure welding and long-term interim storage. The CSH will provide safe handling and dry storage for the SSFCs containing the BFAs. The purpose of this document is to describe the SSFC system and interface equipment, including the technical basis for the system, design descriptions, and operations requirements. It is intended that this document will be periodically updated as more equipment design and performance specification information becomes available.

  14. Shippingport Spent Fuel Canister System Description

    SciTech Connect

    JOHNSON, D.M.

    2000-03-27

    In 1978 and 1979, a total of 72 blanket fuel assemblies (BFAs), irradiated during the operating cycles of the Shippingport Atomic Power Station's Pressurized Water Reactor (PWR) Core 2 from April 1965 to February 1974, were transferred to the Hanford Site and stored in underwater storage racks in Cell 2R at the 221-T Canyon (T-Plant). The initial objective was to recover the produced plutonium in the BFAs, but this never occurred and the fuel assemblies have remained within the water storage pool to the present time. The Shippingport Spent Fuel Canister (SSFC) is a confinement system that provides safe transport functions (in conjunction with the TN-WHC cask) and storage for the BFAs at the Canister Storage Building (CSB). The current plan is for these BFAs to be retrieved from wet storage and loaded into SSFCs for dry storage. The sealed SSFCs containing BFAs will be vacuum dried, internally backfilled with helium, and leak tested to provide suitable confinement for the BFAs during transport and storage. Following completion of the drying and inerting process, the SSFCs are to be delivered to the CSB for closure welding and long-term interim storage. The CSB will provide safe handling and dry storage for the SSFCs containing the BFAs. The purpose of this document is to describe the SSFC system and interface equipment, including the technical basis for the system, design descriptions, and operations requirements. It is intended that this document will be periodically updated as more equipment design and performance specification information becomes available.

  15. The Load and Time Dependence of Chemical Bonding-Induced Frictional Ageing of Silica at the Nanoscale

    NASA Astrophysics Data System (ADS)

    Tian, K.; Gosvami, N. N.; Goldsby, D. L.; Carpick, R. W.

    2015-12-01

    Rate and state friction (RSF) laws are empirical relationships that describe the frictional behavior of rocks and other materials in experiments, and reproduce a variety of observed natural behavior when employed in earthquake models. A pervasive observation from rock friction experiments is the linear increase of static friction with the log of contact time, or 'ageing'. Ageing is usually attributed to an increase in real area of contact associated with asperity creep. However, recent atomic force microscopy (AFM) experiments demonstrate that ageing of nanoscale silica-silica contacts is due to progressive formation of interfacial chemical bonds in the absence of plastic deformation, in a manner consistent with the multi-contact ageing behavior of rocks [Li et al., 2011]. To further investigate chemical bonding-induced ageing, we explored the influence of normal load (and thus contact normal stress) and contact time on ageing. Experiments that mimic slide-hold-slide rock friction experiments were conducted in the AFM for contact loads and hold times ranging from 23 to 393 nN and 0.1 to 100 s, respectively, all in humid air (~50% RH) at room temperature. Experiments were conducted by sequentially sliding the AFM tip on the sample at a velocity V of 0.5 μm/s, setting V to zero and holding the tip stationary for a given time, and finally resuming sliding at 0.5 μm/s to yield a peak value of friction followed by a drop to the sliding friction value. Chemical bonding-induced ageing, as measured by the peak friction minus the sliding friction, increases approximately linearly with the product of normal load and the log of the hold time. Theoretical studies of the roles of reaction energy barriers in nanoscale ageing indicate that frictional ageing depends on the total number of reaction sites and the hold time [Liu & Szlufarska, 2012]. We combine chemical kinetics analyses with contact mechanics models to explain our results, and develop a new approach for curve

  16. Effectiveness of Surgical Release in Patients With Neglected Congenital Muscular Torticollis According to Age at the Time of Surgery

    PubMed Central

    Min, Kyung-Jay; Ahn, Ah-Reum; Park, Eun-Ji

    2016-01-01

    Objective To identify the correlation between change in spinal deformities after surgical release and age at the time of surgery, and the effectiveness of surgical release in patients with neglected congenital muscular torticollis (CMT). Methods This was a retrospective study of 46 subjects with neglected CMT who had undergone surgical release at age ≥5 years at a tertiary medical center between January 2009 and January 2014. Spinal deformities were measured on anteroposterior plain radiographs of the cervical and whole spine, both preoperatively and postoperatively, to assess 3 parameters: cervicomandibular angle (CMA), lateral shift (LS), and Cobb angle (CA). We analyzed the change in spinal deformities after surgical release in consideration of age at the time of surgery. Results The median age at the time of surgery was 12.87 years. All 3 parameters showed significant improvement after surgical release (median values, pre- to post-surgery: CMA, 12.13° to 4.02°; LS, 18.13 mm to 13.55 mm; CA, 6.10° to 4.80°; all p<0.05). There was no significant correlation between age at the time of surgery and change in CMA (R=0.145, p=0.341) and LS (R=0.103, p=0.608). However, CA showed significant improvement with increasing age (R=0.150, p=0.046). Conclusion We assessed the correlation between change in spinal deformities after surgical release and age at the time of surgery. We found that that surgical release is effective for spinal deformities, even in older patients. These findings enhance our understanding of the effectiveness and timing of surgical release in patients with neglected CMT. PMID:26949667

  17. [Reliability of the individual age assessment at the time of death based on sternal rib end morphology in Balkan population].

    PubMed

    Donić, Danijela; Durić, Marija; Babić, Dragan; Popović, Dorde

    2005-06-01

    This paper analyzes the reliability of the Iscan's sternal rib-ends phase method for the assessment of individual age at the time of death in the Balkan population. The method is based on the morphological age changes of the sternal rib ends. The tested samples consisted of 65 ribs from autopsy cases in the Institute for Forensic Medicine, University of Belgrade, during 1999-2002 (23 females, and 42 males of various ages, ranged from 17-91 years), according to the forensic documents. Significant differences between the real chronological age of the individuals and the values established by the Iscan's method was found, especially in the older categories (phases 6 and 7), in both males and females. The results of the discriminative analysis showed the values of the highest diagnostic relevance for the assessment of age in our population: the change of the depth of the articular fossa, the thickness of its walls, and the quality of the bones.

  18. Aging, Fitness, and Marathon Times in a 91 Year-old Man Who Competed in 627 Marathons

    PubMed Central

    Addison, Odessa; Steinbrenner, Gregory; Goldberg, Andrew P.; Katzel, Leslie I.

    2015-01-01

    Aging is associated with a decline in maximal aerobic capacity (VO2max) that may be attenuated by chronic endurance exercise. This case study chronicles the changes in marathon times in a 91 year old man who completed 627 marathons and 117 ultramarathons over 42 years. He began running marathons at age 48. His yearly best times remained fairly constant at ~240 minutes from age 50 – 64 years and then gradually rose to about 260 minutes in his early seventies followed by a curvilinear deterioration as he approached his ninth decade. His times plateaued at ~ 600 minutes in his late eighties. Between ages 68 and 89 his VO2max declined from 43 to 20 ml/kg/min. His marathon times were highly correlated with his VO2max (r2=0.87). The decline in marathons times and VO2max may reflect the contributions of biological aging, changes in exercise training volume and intensity, injuries, and comorbid disease. PMID:26290832

  19. Effects of aging and irradiation time on the properties of a highly translucent resin-based composite.

    PubMed

    Bauer, Henrik; Ilie, Nicoleta

    2013-01-01

    This study investigated the effects of aging and irradiation time on the macro- and micro-mechanical properties of a highly translucent nanohybrid composite (IPS Empress Direct, Trans Opal shade, Ivoclar Vivadent). Flexural strength, flexural modulus, indentation modulus, Vickers hardness, and creep were measured after being irradiated with different durations (5, 10, 20, and 40 s) and aged under different conditions (24 h at 37°C in water; 5,000 times of thermocycling between 5°C and 55°C followed by 4-week storage in artificial saliva or alcohol). Rate of cure was also measured for these four irradiation times at composite specimen surface and at 2 mm depth. Effects of aging and irradiation time were statistically analyzed using one-way ANOVA with Tukey's HSD post hoc test (α=0.05), partial eta-squared statistic, and Weibull analysis. Alcohol aging significantly reduced the mechanical properties. Aging in saliva produced a positive effect on micro-mechanical properties. Irradiation time should be at least 20 s to yield favorable mechanical properties.

  20. Emotional experience in the mornings and the evenings: consideration of age differences in specific emotions by time of day

    PubMed Central

    English, Tammy; Carstensen, Laura L.

    2014-01-01

    Considerable evidence points to age-related improvements in emotional well-being with age. In order to gain a more nuanced understanding of the nature of these apparent shifts in experience, we examined age differences in a range of emotional states in the mornings and evenings in a sample of 135 community-residing participants across 10 consecutive days. Participants ranged in age from 22 to 93 years. Each participant completed a diary in the morning and again in the evening every day for the study period. During each of the assessments, participants reported the degree to which they experienced emotions sampled from all four quadrants of the affective circumplex. Overall, participants felt less positive and more negative in the evenings than in the mornings. As expected, older adults reported a relatively more positive emotional experience than younger adults at both times of day. Importantly, however, age effects varied based on emotion type and time of day. Older adults reported experiencing more positive emotion than relatively younger adults across a range of different positive states (although age differences emerged most consistently for low arousal positive states). Age-related reductions in negative experience were observed only for reports of low arousal negative emotions. There were no age differences in anger, anxiety, or sadness. For some emotions, age differences were stronger in the mornings (e.g., relaxed) whereas for other emotions age differences were more pronounced in the evenings (e.g., enthusiastic). Findings are discussed in the context of adulthood changes in motivation and emotional experience. PMID:24639663

  1. Emotional experience in the mornings and the evenings: consideration of age differences in specific emotions by time of day.

    PubMed

    English, Tammy; Carstensen, Laura L

    2014-01-01

    Considerable evidence points to age-related improvements in emotional well-being with age. In order to gain a more nuanced understanding of the nature of these apparent shifts in experience, we examined age differences in a range of emotional states in the mornings and evenings in a sample of 135 community-residing participants across 10 consecutive days. Participants ranged in age from 22 to 93 years. Each participant completed a diary in the morning and again in the evening every day for the study period. During each of the assessments, participants reported the degree to which they experienced emotions sampled from all four quadrants of the affective circumplex. Overall, participants felt less positive and more negative in the evenings than in the mornings. As expected, older adults reported a relatively more positive emotional experience than younger adults at both times of day. Importantly, however, age effects varied based on emotion type and time of day. Older adults reported experiencing more positive emotion than relatively younger adults across a range of different positive states (although age differences emerged most consistently for low arousal positive states). Age-related reductions in negative experience were observed only for reports of low arousal negative emotions. There were no age differences in anger, anxiety, or sadness. For some emotions, age differences were stronger in the mornings (e.g., relaxed) whereas for other emotions age differences were more pronounced in the evenings (e.g., enthusiastic). Findings are discussed in the context of adulthood changes in motivation and emotional experience.

  2. Acidogenic spent wash valorization through polyhydroxyalkanoate (PHA) synthesis coupled with fermentative biohydrogen production.

    PubMed

    Amulya, K; Reddy, M Venkateswar; Mohan, S Venkata

    2014-04-01

    The production of polyhydroxyalkanoates (PHAs) by Bacillus tequilensis biocatalyst using spent wash effluents as substrate was evaluated to increase the versatility of the existing PHA production process and reduce production cost. In this study, spent wash was used as a substrate for biohydrogen (H2) production and the resulting acidogenic effluents were subsequently employed as substrate for PHA production. Maximum H2 production of 39.8L and maximum PHA accumulation of 40% dry cell weight was attained. Good substrate removal associated with decrement in acidification (53% to 15%) indicates that the VFA generated were effectively utilized for PHA production. The PHA composition showed presence of copolymer [P (3HB-co-3HV)] with varying contents of hydroxybutyrate and hydroxyvalerate. The results obtained suggest that the use of spent wash effluents as substrate can considerably reduce the production cost of PHA with simultaneous waste valorization. PHA synthesis with B. tequilensis and spent wash effluents is reported for the first time.

  3. Technical framework to facilitate foreign spent fuel storage and geologic disposal in Russia

    SciTech Connect

    Jardine, L J; Halsey, W G; Cmith, C F

    2000-01-31

    The option of storage and eventual geologic disposal in Russia of spent fuel of US origin used in Taiwan provides a unique opportunity that can benefit many parties. Taiwan has a near term need for a spent fuel storage and geologic disposal solution, available financial resources, but limited prospect for a timely domestic solution. Russia has significant spent fuel storage and transportation management experience, candidate storage and repository sites, but limited financial resources available for their development. The US has interest in Taiwan energy security, national security and nonproliferation interests in Russian spent fuel storage and disposal and interest in the US origin fuel. While it is understood that such a project includes complex policy and international political issues as well as technical issues, the goal of this paper is to begin the discussion by presenting a technical path forward to establish the feasibility of this concept for Russia.

  4. Unmasking the 'elderly mystique': Why it is time to make the personal political in ageing research.

    PubMed

    Carney, Gemma M; Gray, Mia

    2015-12-01

    This article uses feminist scholarship to investigate 'the elderly mystique'-which contends that the potential of old age is masked by a set of false beliefs about ageing (i.e. ageism) which permeate social, economic, and political life (Cohen, 1988). The article presents a theoretical model which explores the extent to which institutionalised ageism shapes the trajectory of life after 60.(1) The hypothesis underpinning the model is simple: The challenge for ageing societies is not the average age of a given population, but rather, how age is used to structure economic, social and political life. An inter-disciplinary framework is used to examine how biological facts about ageing are used to segregate older from younger people, giving older people the status of 'other'; economically through retirement, politically through assumptions about 'the grey vote,' and socially through ageist stereotyping in the media and through denial and ridicule of the sexuality of older people. Each domain is informed by the achievements of feminist theory and research on sexism and how its successes and failures can inform critical investigations of ageism. The paper recognises the role of ageism in de-politicising the lived experience of ageing. The paper concludes that feminist scholarship, particularly work by feminists in their seventies, eighties, and nineties, has much to offer in terms of re-framing gerontology as an emancipatory project for current and future cohorts of older people.

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

    PubMed Central

    Thoren, Katharina; Heinig, Elisa; Brunner, Martin

    2016-01-01

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

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

    PubMed

    Thoren, Katharina; Heinig, Elisa; Brunner, Martin

    2016-01-01

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

  7. Age, time period, and birth cohort differences in self-esteem: Reexamining a cohort-sequential longitudinal study.

    PubMed

    Twenge, Jean M; Carter, Nathan T; Campbell, W Keith

    2016-12-08

    Orth, Trzesniewski, and Robins (2010) concluded that the nationally representative Americans' Changing Lives (ACL) cohort-sequential study demonstrated moderate to large age differences in self-esteem, and no birth cohort (generational) differences in the age trajectory. In a reanalysis of these data using 2 different statistical techniques, we find significant increases in self-esteem that could be attributed to birth cohort or time period. First, hierarchical linear modeling analyses with birth cohort as a continuous variable (vs. the multiple group formulation used by Orth et al.) find that birth cohort has a measurable influence on self-esteem through its interaction with age. Participants born in later years (e.g., 1960) were higher in self-esteem and were more likely to increase in self-esteem as they aged than participants born in earlier years (e.g., 1920). However, the estimated age trajectory up to age 60 is similar in Orth et al.'s results and in the results from our analyses including cohort. Second, comparing ACL respondents of the same age in 1986 versus 2002 (a time-lag design) yields significant birth cohort differences in self-esteem, with 2002 participants of the same age higher in self-esteem than those in 1986. Combined with some previous studies finding significant increases in self-esteem and positive self-views over time, these results suggest that cultural change in the form of cohort and time period cannot be ignored as influences in cross-sectional and longitudinal studies. (PsycINFO Database Record

  8. Aging and Tennis Playing in a Coincidence-Timing Task with an Accelerating Object: The Role of Visuomotor Delay

    ERIC Educational Resources Information Center

    Lobjois, Regis; Benguigui, Nicolas; Bertsch, Jean

    2005-01-01

    The purpose of the present study was to determine whether playing a specific ball sport, such as tennis, could maintain the coincidence-timing (CT) performance of older adults at a similar level to that of younger ones. To address this question, tennis players and nonplayers of three different age ranges (ages 20-30, 60-70, and 70-80 years)…

  9. Age and timing of the Permian mass extinctions: U/Pb dating of closed-system zircons.

    PubMed

    Mundil, Roland; Ludwig, Kenneth R; Metcalfe, Ian; Renne, Paul R

    2004-09-17

    The age and timing of the Permian-Triassic mass extinction have been difficult to determine because zircon populations from the type sections are typically affected by pervasive lead loss and contamination by indistinguishable older xenocrysts. Zircons from nine ash beds within the Shangsi and Meishan sections (China), pretreated by annealing followed by partial attack with hydrofluoric acid, result in suites of consistent and concordant uranium/lead (U/Pb) ages, eliminating the effects of lead loss. The U/Pb age of the main pulse of the extinction is 252.6 +/- 0.2 million years, synchronous with the Siberian flood volcanism, and it occurred within the quoted uncertainty.

  10. Spent Nuclear Fuel Project Technical Databook

    SciTech Connect

    Reilly, M.A.

    1998-10-23

    The Spent Nuclear Fuel (SNF) Project Technical Databook is developed for use as a common authoritative source of fuel behavior and material parameters in support of the Hanford SNF Project. The Technical Databook will be revised as necessary to add parameters as their Databook submittals become available.

  11. Corrosion of spent Advanced Test Reactor fuel

    SciTech Connect

    Lundberg, L.B.; Croson, M.L.

    1994-11-01

    The results of a study of the condition of spent nuclear fuel elements from the Advanced Test Reactor (ATR) currently being stored underwater at the Idaho National Engineering Laboratory (INEL) are presented. This study was motivated by a need to estimate the corrosion behavior of dried, spent ATR fuel elements during dry storage for periods up to 50 years. The study indicated that the condition of spent ATR fuel elements currently stored underwater at the INEL is not very well known. Based on the limited data and observed corrosion behavior in the reactor and in underwater storage, it was concluded that many of the fuel elements currently stored under water in the facility called ICPP-603 FSF are in a degraded condition, and it is probable that many have breached cladding. The anticipated dehydration behavior of corroded spent ATR fuel elements was also studied, and a list of issues to be addressed by fuel element characterization before and after forced drying of the fuel elements and during dry storage is presented.

  12. Microbial recovery of metals from spent catalysts

    SciTech Connect

    Sperl, P.L.; Sperl, G.T.

    1990-01-01

    This project was initiated on October 1, 1989, for the purpose of recovering metals from spent coal liquefaction catalysts. Two catalyst types are the subject of the contract. The first is a Ni-Mo catalyst supported on alumina (Shell 324) as is used in a pilot scale coal liquefaction facility at Wilsonville, Alabama. This plant is run and operated by Southern Clean Fuels. A large sample of spent catalyst from this facility has been obtained. The second material is an unsupported ammonium molybdate catalyst used in a pilot process by the Department of Energy at the Pittsburgh Energy Technology Center. This material was obtained in late February 1990 but has not been pursued since the No content of this particular sample is too low for the current studies. The object of the contract is to treat these spent catalysts with microorganisms, especially Thiobacillus ferrooxidans, but also other Thiobacillus sp. and possibly Sulfolobus, to leach and remove the metals (Ni and Mo) from the spent catalysts into a form which can be readily recovered by conventional techniques.

  13. Total quality in spent fuel pool reracking

    SciTech Connect

    Cranston, J.S.; Taglianetti, J.N.; Schaeffer, D.G.; Bradbury, R.B.; Cacciapouti, R.J.

    1993-12-31

    The nuclear utility environment is one of strict cost control under prescriptive regulations and increasing public scrutiny. This paper presents the results of A Total Quality approach, by a dedicated team, that addresses the need for increased on-site spent fuel storage in this environment. Innovations to spent fuel pool reracking, driven by utilities` specific technical needs and shrinking budgets, have resulted in both product improvements and lower prices. A Total Quality approach to the entire turnkey project is taken, thereby creating synergism and process efficiency in each of the major phases of the project: design and analysis, licensing, fabrication, installation and disposal. Specific technical advances and the proven quality of the team members minimizes risk to the utility and its shareholders and provides a complete, cost effective service. Proper evaluation of spent fuel storage methods and vendors requires a full understanding of currently available customer driven initiatives that reduce cost while improving quality. In all phases of a spent fuel reracking project, from new rack design and analysis through old rack disposal, the integration of diverse experts, at all levels and throughout all phases of a reracking project, better serves utility needs. This Total Quality environment in conjunction with many technical improvements results in a higher quality product at a lower cost.

  14. Biotreatment of refinery spent sulfidic caustics

    SciTech Connect

    Sublette, K.L.; Rajganesh, B.; Woolsey, M.; Plato, A.

    1995-12-31

    Caustics are used in petroleum refinering to remove hydrogen sulfide from various hydrocarbon streams. Spent sulfidic caustics from two Conoco refineries have been successfully biotreated on bench and pilot scale, resulting in neutralization and removal of active sulfides. Sulfides were completely oxidized to sulfate by Thiobacillus denitrificans. Microbial oxidation of sulfide produced acid, which at least partially neutralized the caustic.

  15. Spent fuel pin temperature PC code

    SciTech Connect

    Fischer, L.E.

    1985-03-01

    During an annual outage, a Pressurized Water Reactor (PWR) may discharge 60 or more spent fuel bundles into its storage pool. Most early PWRs were built to store 3 to 5 years of spent fuel in their pools and are beginning to exceed their capacities. One method currently being developed and licensed for expanding spent fuel storage capabilities is the dry storage of spent fuel in large casks. To reduce the probability of gross failures of fuel cladding during dry storage in casks, the fuel pin temperatures must be shown to remain within acceptable limits. LLNL has developed, for the Nuclear Regulatory Commission, a personal computer (PC) code for calculating fuel pin temperatures on the IBM PC. The code uses the Wooton-Epstein Correlation to calculate the pin temperatures and has been benchmarked against test data. An iterative type of solution is used to calculate the fuel pin temperatures for specified heat fluxes and pin configurations. The PC code is useful in performing confirmatory analyses and comparing the results with those submitted by applicants applying for storage licenses. 5 references, 2 tables.

  16. Digital Games for Young Children Ages Three to Six: From Research to Design

    ERIC Educational Resources Information Center

    Lieberman, Debra A.; Fisk, Maria Chesley; Biely, Erica

    2009-01-01

    Young children ages 3 to 6 play a wide range of digital games, which are now available on large screens, handheld screens, electronic learning systems, and electronic toys, and their time spent with games is growing. This article examines effects of digital games and how they could be designed to best serve children's needs. A small body of…

  17. Microglia change from a reactive to an age-like phenotype with the time in culture

    PubMed Central

    Caldeira, Cláudia; Oliveira, Ana F.; Cunha, Carolina; Vaz, Ana R.; Falcão, Ana S.; Fernandes, Adelaide; Brites, Dora

    2014-01-01

    Age-related neurodegenerative diseases have been associated with chronic neuroinflammation and microglia activation. However, cumulative evidence supports that inflammation only occurs at an early stage once microglia change the endogenous characteristics with aging and switch to irresponsive/senescent and dystrophic phenotypes with disease progression. Thus, it will be important to have the means to assess the role of reactive and aged microglia when studying advanced brain neurodegeneration processes and age-associated related disorders. Yet, most studies are done with microglia from neonates since there are no adequate means to isolate degenerating microglia for experimentation. Indeed, only a few studies report microglia isolation from aged animals, using either short-term cultures or high concentrations of mitogens in the medium, which trigger microglia reactivity. The purpose of this study was to develop an experimental process to naturally age microglia after isolation from neonatal mice and to characterize the cultured cells at 2 days in vitro (DIV), 10 DIV, and 16 DIV. We found that 2 DIV (young) microglia had predominant amoeboid morphology and markers of stressed/reactive phenotype. In contrast, 16 DIV (aged) microglia evidenced ramified morphology and increased matrix metalloproteinase (MMP)-2 activation, as well as reduced MMP-9, glutamate release and nuclear factor kappa-B activation, in parallel with decreased expression of Toll-like receptor (TLR)-2 and TLR-4, capacity to migrate and phagocytose. These findings together with the reduced expression of microRNA (miR)-124, and miR-155, decreased autophagy, enhanced senescence associated beta-galactosidase activity and elevated miR-146a expression, are suggestive that 16 DIV cells mainly correspond to irresponsive/senescent microglia. Data indicate that the model represent an opportunity to understand and control microglial aging, as well as to explore strategies to recover microglia surveillance

  18. Effect of Aging Time on Physicochemical Meat Quality and Sensory Property of Hanwoo Bull Beef.

    PubMed

    Cho, Soohyun; Kang, Sun Moon; Seong, Pilnam; Kang, Geunho; Kim, Yunseok; Kim, Jinhyung; Lee, Seounghwan; Kim, Sidong

    2016-01-01

    This study was conducted to investigate the meat quality and sensory properties of 12 major cuts from 10 Hanwoo bulls (25-32 mon of age) after they were aged at 2℃ for 0, 7, 14, and 21 d. Protein content (%) was between 19.17 and 22.50%. Intramuscular fat content ranged from 2.79 to 8.39%. The collagen content of the chuck roll, chuck tender, and short plate muscles was higher (1.97-2.04%) than that of the striploin muscles (1.48%) (p<0.05). CIE lightness (L*) values increased with an increase in aging days for tenderloin, loin, chuck roll, oyster blade, short plate, top sirloin, and eye of round muscles (p<0.05). Most muscles, except the short plate, showed no significant changes in redness CIE (a*) and yellowness (b*) color values during aging. The tenderloin, loin, and striploin showed significantly higher water holding capacity (58.60-62.06%) than that of chuck roll and short plate (53.86-57.07%) muscles (p<0.05). The Warner-Bratzler shear force values of most muscles decreased significantly as the aging period increased (p<0.05), exception the tenderloin. The chuck tender muscles showed the highest cooking loss, whereas tenderloin muscle showed the lowest (p<0.05). The tenderloin muscle had the longest sarcomere length (SL) (3.67-3.86 μm) and the bottom round muscle had the shortest SL (2.21-2.35 μm) (p<0.05). In the sensory evaluation, tenderness and overall-likeness scores of most muscles increased with increase in aging days. The tenderloin and oyster blade showed relatively higher tenderness and overall-likeness values than did the other muscles during the aging period. No significant differences were noted in juiciness and flavor-likeness scores among muscles and aging days.

  19. Effect of Aging Time on Physicochemical Meat Quality and Sensory Property of Hanwoo Bull Beef

    PubMed Central

    Lee, Seounghwan

    2016-01-01

    This study was conducted to investigate the meat quality and sensory properties of 12 major cuts from 10 Hanwoo bulls (25-32 mon of age) after they were aged at 2℃ for 0, 7, 14, and 21 d. Protein content (%) was between 19.17 and 22.50%. Intramuscular fat content ranged from 2.79 to 8.39%. The collagen content of the chuck roll, chuck tender, and short plate muscles was higher (1.97-2.04%) than that of the striploin muscles (1.48%) (p<0.05). CIE lightness (L*) values increased with an increase in aging days for tenderloin, loin, chuck roll, oyster blade, short plate, top sirloin, and eye of round muscles (p<0.05). Most muscles, except the short plate, showed no significant changes in redness CIE (a*) and yellowness (b*) color values during aging. The tenderloin, loin, and striploin showed significantly higher water holding capacity (58.60-62.06%) than that of chuck roll and short plate (53.86-57.07%) muscles (p<0.05). The Warner-Bratzler shear force values of most muscles decreased significantly as the aging period increased (p<0.05), exception the tenderloin. The chuck tender muscles showed the highest cooking loss, whereas tenderloin muscle showed the lowest (p<0.05). The tenderloin muscle had the longest sarcomere length (SL) (3.67-3.86 μm) and the bottom round muscle had the shortest SL (2.21-2.35 μm) (p<0.05). In the sensory evaluation, tenderness and overall-likeness scores of most muscles increased with increase in aging days. The tenderloin and oyster blade showed relatively higher tenderness and overall-likeness values than did the other muscles during the aging period. No significant differences were noted in juiciness and flavor-likeness scores among muscles and aging days. PMID:27499666

  20. Effect of sol aging time on the anti-reflective properties of silica coatings templated with phosphoric acid

    NASA Astrophysics Data System (ADS)

    Wen, Wen; Li, Haibin; Chen, Xiaojing; Chang, Chengkang

    Silica anti-reflective coatings have been prepared by a sol-gel dip-coating process using the sol containing phosphoric acid as a pore-forming template. The effect of the aging time of the sol on the anti-reflective properties has been investigated. The surface topography of the silica AR coatings has been characterized. With increasing sol aging time, more over-sized pores larger than 100 nm are formed in the silica coatings. These could act as scattering centers, scattering visible light and thereby lowering transmittance. The optimal aging time was identified as 1 day, and the corresponding silica coatings showed a maximum transmittance of 99.2%, representing an 8% increase compared to the bare glass substrate.

  1. Aging underdamped scaled Brownian motion: Ensemble- and time-averaged particle displacements, nonergodicity, and the failure of the overdamping approximation.

    PubMed

    Safdari, Hadiseh; Cherstvy, Andrey G; Chechkin, Aleksei V; Bodrova, Anna; Metzler, Ralf

    2017-01-01

    We investigate both analytically and by computer simulations the ensemble- and time-averaged, nonergodic, and aging properties of massive particles diffusing in a medium with a time dependent diffusivity. We call this stochastic diffusion process the (aging) underdamped scaled Brownian motion (UDSBM). We demonstrate how the mean squared displacement (MSD) and the time-averaged MSD of UDSBM are affected by the inertial term in the Langevin equation, both at short, intermediate, and even long diffusion times. In particular, we quantify the ballistic regime for the MSD and the time-averaged MSD as well as the spread of individual time-averaged MSD trajectories. One of the main effects we observe is that, both for the MSD and the time-averaged MSD, for superdiffusive UDSBM the ballistic regime is much shorter than for ordinary Brownian motion. In contrast, for subdiffusive UDSBM, the ballistic region extends to much longer diffusion times. Therefore, particular care needs to be taken under what conditions the overdamped limit indeed provides a correct description, even in the long time limit. We also analyze to what extent ergodicity in the Boltzmann-Khinchin sense in this nonstationary system is broken, both for subdiffusive and superdiffusive UDSBM. Finally, the limiting case of ultraslow UDSBM is considered, with a mixed logarithmic and power-law dependence of the ensemble- and time-averaged MSDs of the particles. In the limit of strong aging, remarkably, the ordinary UDSBM and the ultraslow UDSBM behave similarly in the short time ballistic limit. The approaches developed here open ways for considering other stochastic processes under physically important conditions when a finite particle mass and aging in the system cannot be neglected.

  2. Aging underdamped scaled Brownian motion: Ensemble- and time-averaged particle displacements, nonergodicity, and the failure of the overdamping approximation

    NASA Astrophysics Data System (ADS)

    Safdari, Hadiseh; Cherstvy, Andrey G.; Chechkin, Aleksei V.; Bodrova, Anna; Metzler, Ralf

    2017-01-01

    We investigate both analytically and by computer simulations the ensemble- and time-averaged, nonergodic, and aging properties of massive particles diffusing in a medium with a time dependent diffusivity. We call this stochastic diffusion process the (aging) underdamped scaled Brownian motion (UDSBM). We demonstrate how the mean squared displacement (MSD) and the time-averaged MSD of UDSBM are affected by the inertial term in the Langevin equation, both at short, intermediate, and even long diffusion times. In particular, we quantify the ballistic regime for the MSD and the time-averaged MSD as well as the spread of individual time-averaged MSD trajectories. One of the main effects we observe is that, both for the MSD and the time-averaged MSD, for superdiffusive UDSBM the ballistic regime is much shorter than for ordinary Brownian motion. In contrast, for subdiffusive UDSBM, the ballistic region extends to much longer diffusion times. Therefore, particular care needs to be taken under what conditions the overdamped limit indeed provides a correct description, even in the long time limit. We also analyze to what extent ergodicity in the Boltzmann-Khinchin sense in this nonstationary system is broken, both for subdiffusive and superdiffusive UDSBM. Finally, the limiting case of ultraslow UDSBM is considered, with a mixed logarithmic and power-law dependence of the ensemble- and time-averaged MSDs of the particles. In the limit of strong aging, remarkably, the ordinary UDSBM and the ultraslow UDSBM behave similarly in the short time ballistic limit. The approaches developed here open ways for considering other stochastic processes under physically important conditions when a finite particle mass and aging in the system cannot be neglected.

  3. Revised timing of the South American early Paleogene land mammal ages

    NASA Astrophysics Data System (ADS)

    Woodburne, Michael O.; Goin, Francisco J.; Raigemborn, Maria Sol; Heizler, Matt; Gelfo, Javier N.; Oliveira, Edison V.

    2014-10-01

    A new Ar/Ar date on the Las Flores Tuff (Río Chico Group, Las Flores Fm., central Patagonia, Argentina) yielded an age of 49.512 ± 0.019 Ma. This tuff, which stratigraphically overlies the mammal-bearing deposits that produced the Las Flores fauna, helps constrain the age of the Itaboraian SALMA [South American Land Mammal Age] to which that fauna is referred. The new data also have implications for the age of succeeding mammal biochrons, such as the Riochican and “Sapoan” which are revised to being somewhat younger than previously interpreted. Although closer in age than formerly interpreted, they still are biotically distinct. Concomitant evaluations suggest that the Itaboraian SALMA is perhaps more contemporary with the EECO (Early Eocene Climatic Optimum) than previously considered. The Riochican may be interpreted as post-EECO, with its cooler climate consistent in that regard. A recent reconsideration of the chronology of elements of the Salamanca Formation resulted in the downward revision of the ages of the Peligran SALMA and the Carodnia Zone biochrons. These operations, together with our results, reflect a 9 m.y. gap in the late Paleocene and early Eocene land mammal record in South America.

  4. Numerical Estimation of the Spent Fuel Ratio

    SciTech Connect

    Lindgren, Eric R.; Durbin, Samuel; Wilke, Jason; Margraf, J.; Dunn, T. A.

    2016-01-01

    Sabotage of spent nuclear fuel casks remains a concern nearly forty years after attacks against shipment casks were first analyzed and has a renewed relevance in the post-9/11 environment. A limited number of full-scale tests and supporting efforts using surrogate materials, typically depleted uranium dioxide (DUO 2 ), have been conducted in the interim to more definitively determine the source term from these postulated events. However, the validity of these large- scale results remain in question due to the lack of a defensible spent fuel ratio (SFR), defined as the amount of respirable aerosol generated by an attack on a mass of spent fuel compared to that of an otherwise identical surrogate. Previous attempts to define the SFR in the 1980's have resulted in estimates ranging from 0.42 to 12 and include suboptimal experimental techniques and data comparisons. Because of the large uncertainty surrounding the SFR, estimates of releases from security-related events may be unnecessarily conservative. Credible arguments exist that the SFR does not exceed a value of unity. A defensible determination of the SFR in this lower range would greatly reduce the calculated risk associated with the transport and storage of spent nuclear fuel in dry cask systems. In the present work, the shock physics codes CTH and ALE3D were used to simulate spent nuclear fuel (SNF) and DUO 2 targets impacted by a high-velocity jet at an ambient temperature condition. These preliminary results are used to illustrate an approach to estimate the respirable release fraction for each type of material and ultimately, an estimate of the SFR. This page intentionally blank

  5. A simple method for estimating informative node age priors for the fossil calibration of molecular divergence time analyses.

    PubMed

    Nowak, Michael D; Smith, Andrew B; Simpson, Carl; Zwickl, Derrick J

    2013-01-01

    Molecular divergence time analyses often rely on the age of fossil lineages to calibrate node age estimates. Most divergence time analyses are now performed in a Bayesian framework, where fossil calibrations are incorporated as parametric prior probabilities on node ages. It is widely accepted that an ideal parameterization of such node age prior probabilities should be based on a comprehensive analysis of the fossil record of the clade of interest, but there is currently no generally applicable approach for calculating such informative priors. We provide here a simple and easily implemented method that employs fossil data to estimate the likely amount of missing history prior to the oldest fossil occurrence of a clade, which can be used to fit an informative parametric prior probability distribution on a node age. Specifically, our method uses the extant diversity and the stratigraphic distribution of fossil lineages confidently assigned to a clade to fit a branching model of lineage diversification. Conditioning this on a simple model of fossil preservation, we estimate the likely amount of missing history prior to the oldest fossil occurrence of a clade. The likelihood surface of missing history can then be translated into a parametric prior probability distribution on the age of the clade of interest. We show that the method performs well with simulated fossil distribution data, but that the likelihood surface of missing history can at times be too complex for the distribution-fitting algorithm employed by our software tool. An empirical example of the application of our method is performed to estimate echinoid node ages. A simulation-based sensitivity analysis using the echinoid data set shows that node age prior distributions estimated under poor preservation rates are significantly less informative than those estimated under high preservation rates.

  6. Social-cognitive predictors of low-income parents' restriction of screen time among preschool-aged children.

    PubMed

    Lampard, Amy M; Jurkowski, Janine M; Davison, Kirsten K

    2013-10-01

    Parents' rules regarding child television, DVD, video game, and computer use (screen time) have been associated with lower screen use in children. This study aimed to identify modifiable correlates of this behavior by examining social-cognitive predictors of parents' restriction of child screen time. Low-income parents (N = 147) of preschool-aged children (2-6 years) completed self-administered questionnaires examining parent and child screen time, parent restriction of screen time, self-efficacy to restrict screen time, and beliefs about screen time. Structural equation modeling results indicated that greater self-efficacy to restrict screen time (β = .29, p = .016) and greater perceived importance of restricting child screen use (β = .55, p < .001) were associated with greater restriction of child screen use, after controlling for parent screen time. Family-based interventions that consider broader attitudinal factors around child screen time may be necessary to engage parents in restricting screen use.

  7. Metacognitive Influences on Study Time Allocation in an Associative Recognition Task: An Analysis of Adult Age Differences

    PubMed Central

    Hines, Jarrod C.; Touron, Dayna R.; Hertzog, Christopher

    2009-01-01

    The current study evaluated a metacognitive account of study time allocation, which argues that metacognitive monitoring of recognition test accuracy and latency influences subsequent strategic control and regulation. We examined judgments of learning (JOLs), recognition test confidence judgments (CJs), and subjective response time (RT) judgments by younger and older adults in an associative recognition task involving two study-test phases, with self-paced study in phase 2. Multilevel regression analyses assessed the degree to which age and metacognitive variables predicted phase 2 study time independent of actual test accuracy and RT. Outcomes supported the metacognitive account – JOLs and CJs predicted study time independent of recognition accuracy. For older adults with errant RT judgments, subjective retrieval fluency influenced response confidence as well as (mediated through confidence) subsequent study time allocation. Older adults studied items longer which had been assigned lower CJs, suggesting no age deficit in using memory monitoring to control learning. PMID:19485662

  8. Real-Time fMRI in Neuroscience Research and Its Use in Studying the Aging Brain

    PubMed Central

    Rana, Mohit; Varan, Andrew Q.; Davoudi, Anis; Cohen, Ronald A.; Sitaram, Ranganatha; Ebner, Natalie C.

    2016-01-01

    Cognitive decline is a major concern in the aging population. It is normative to experience some deterioration in cognitive abilities with advanced age such as related to memory performance, attention distraction to interference, task switching, and processing speed. However, intact cognitive functioning in old age is important for leading an independent day-to-day life. Thus, studying ways to counteract or delay the onset of cognitive decline in aging is crucial. The literature offers various explanations for the decline in cognitive performance in aging; among those are age-related gray and white matter atrophy, synaptic degeneration, blood flow reduction, neurochemical alterations, and change in connectivity patterns with advanced age. An emerging literature on neurofeedback and Brain Computer Interface (BCI) reports exciting results supporting the benefits of volitional modulation of brain activity on cognition and behavior. Neurofeedback studies based on real-time functional magnetic resonance imaging (rtfMRI) have shown behavioral changes in schizophrenia and behavioral benefits in nicotine addiction. This article integrates research on cognitive and brain aging with evidence of brain and behavioral modification due to rtfMRI neurofeedback. We offer a state-of-the-art description of the rtfMRI technique with an eye towards its application in aging. We present preliminary results of a feasibility study exploring the possibility of using rtfMRI to train older adults to volitionally control brain activity. Based on these first findings, we discuss possible implementations of rtfMRI neurofeedback as a novel technique to study and alleviate cognitive decline in healthy and pathological aging. PMID:27803662

  9. Time-dependent dysregulation of autophagy: Implications in aging and mitochondrial homeostasis in the kidney proximal tubule

    PubMed Central

    Yamamoto, Takeshi; Takabatake, Yoshitsugu; Kimura, Tomonori; Takahashi, Atsushi; Namba, Tomoko; Matsuda, Jun; Minami, Satoshi; Kaimori, Jun-ya; Matsui, Isao; Kitamura, Harumi; Matsusaka, Taiji; Niimura, Fumio; Yanagita, Motoko; Isaka, Yoshitaka; Rakugi, Hiromi

    2016-01-01

    ABSTRACT Autophagy plays an essential role in cellular homeostasis through the quality control of proteins and organelles. Although a time-dependent decline in autophagic activity is believed to be involved in the aging process, the issue remains controversial. We previously demonstrated that autophagy maintains proximal tubular cell homeostasis and protects against kidney injury. Here, we extend that study and examine how autophagy is involved in kidney aging. Unexpectedly, the basal autophagic activity was higher in the aged kidney than that in young kidney; short-term cessation of autophagy in tamoxifen-inducible proximal tubule-specific autophagy-deficient mice increased the accumulation of SQSTM1/p62- and ubiquitin-positive aggregates in the aged kidney. By contrast, autophagic flux in response to metabolic stress was blunted with aging, as demonstrated by the observation that transgenic mice expressing a green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3B fusion construct, showed a drastic increase of GFP-positive puncta in response to starvation in young mice compared to a slight increase observed in aged mice. Finally, proximal tubule-specific autophagy-deficient mice at 24 mo of age exhibited a significant deterioration in kidney function and fibrosis concomitant with mitochondrial dysfunction as well as mitochondrial DNA abnormalities and nuclear DNA damage, all of which are hallmark characteristics of cellular senescence. These results suggest that age-dependent high basal autophagy plays a crucial role in counteracting kidney aging through mitochondrial quality control. Furthermore, a reduced capacity for upregulation of autophagic flux in response to metabolic stress may be associated with age-related kidney diseases. PMID:26986194

  10. Sleep and Aging

    MedlinePlus

    ... the sleep-wake process and our circadian biologic clock -- regulate our sleep. They program our bodies to ... on the time spent awake. Our circadian biologic clock is a 24-hour body rhythm affected by ...

  11. Atmospheric Aging of Semi-volatile Pesticides: Real Time Monitoring of Cypermethrin Photo- oxidation Using FTIR

    NASA Astrophysics Data System (ADS)

    Segal-Rosenheimer, M.; Dobuwski, Y.

    2007-12-01

    Pesticides are highly toxic compounds that unlike other pollutants are intentionally introduced, in large quantities, to the environment. The vast majority of them are applied to agricultural lands, but they are also widely used in urban areas as herbicides, insecticides and fungicides. Pesticides may be promoted into the atmosphere during their application via drift of aerosols, as well as by volatilization or dust erosion from treated surfaces after application. In the atmosphere, semi-volatile pesticides may remain as pure aerosols or become adsorbed upon background aerosols or surfaces. During transport or as deposited thin films, they undergo chemical degradation processes due to interaction with atmospheric oxidants and/or solar radiation. Although previous studies indicate that a major portion of applied pesticides wind up in the atmosphere, this is the medium about which we know the least regarding pesticides' fate. Quantitative data regarding aging processes of these hazard air pollutants are important in order to asses their environmental fate and impact. The present study investigates the heterogeneous reaction of thin film of cypermethrin, a common used insecticide, with atmospheric ozone and UV radiation. The reactions are monitored in real time using novel apparatus that combines ATR/FTIR and Long-path IR gas cell for examining the condensed and gas phases, respectively. The obtained data, including oxidation rate constants and photochemical quantum yields, are used to determine atmospheric lifetime of cypermethrin and its probability to reach non-target regions. Kinetic results from the oxidation of cypermethrin with different concentrations of ozone show that its atmospheric half-life time, with regard to ozone, is in the same order of magnitude as other known degradation processes in the soil and water compartments. Also is shown that some of the condensed phase products are more water soluble than the parent molecule, hence having higher potential

  12. Exercise Time: Gender Differences in the Effects of Marriage, Parenthood, and Employment

    ERIC Educational Resources Information Center

    Nomaguchi, Kei M.; Bianchi, Suzanne M.

    2004-01-01

    Using data from a supplement to the 1995 National Health Interview Survey, this article examines the relationship among three major work and family roles - marriage, parenthood, and employment - and time spent on exercise among American men and women ages 18 to 64 N=13,496. As the time availability perspective suggests, work and family roles…

  13. Preschool and school age activities: comparison of urban and suburban populations.

    PubMed

    Damore, Dorothy T

    2002-06-01

    The objective of this study was to compare urban and suburban preschool and school age activities. A prospective survey using a convenience sample was conducted at one urban and one suburban primary care pediatric office. Questionnaires were completed for 66 urban preschool children, 70 suburban preschool children, 57 urban school age children and 61 suburban school age children during the school year. Also, questionniaires were completed for 63 suburban school age children during the summer. The suburban preschool children spent more time outdoors, were read to more frequently, visited the library more frequently and more often attended summer camp. The suburban school age children spent more time outdoors, more frequently participated in a community sport league and more often attended summer camp. The urban school age children watched more television or videos. During the summer, suburban school age children spent more time outdoors, while during the school year, suburban school age children used the library more frequently. Important differences exist between the activities of urban and suburban children in two practices in the New York metropolitan area. Pediatricians caring for urban children may have an important opportunity to promote participation in sports and educational activities.

  14. The effect of obesity and increasing age on operative time and length of stay in primary hip and knee arthroplasty.

    PubMed

    Bradley, Ben M; Griffiths, Shelly N; Stewart, Kyle J; Higgins, Gordon A; Hockings, Michael; Isaac, David L

    2014-10-01

    We retrospectively reviewed 589 patients undergoing lower-limb arthroplasty, recording age, body mass index (BMI) and co-morbidities. The effect of these on operative duration and length of stay (LOS) was analysed. For a 1 point increase in BMI we expect LOS to increase by a factor of 2.9% and mean theatre time to increase by 1.46minutes. For a 1-year increase in age, we expect LOS to increase by a factor of 1.2%. We have calculated the extra financial costs associated. The current reimbursement system underestimates the financial impact of BMI and age. The results have been used to produce a chart that allows prediction of LOS following lower limb arthroplasty based on BMI and age. These data are of use in planning operating lists.

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  16. Nuclear mass inventory, photon dose rate and thermal decay heat of spent research reactor fuel assemblies

    SciTech Connect

    Pond, R.B.; Matos, J.E.

    1996-05-01

    As part of the Department of Energy`s spent nuclear fuel acceptance criteria, the mass of uranium and transuranic elements in spent research reactor fuel must be specified. These data are, however, not always known or readily determined. It is the purpose of this report to provide estimates of these data for some of the more common research reactor fuel assembly types. The specific types considered here are MTR, TRIGA and DIDO fuel assemblies. The degree of physical protection given to spent fuel assemblies is largely dependent upon the photon dose rate of the spent fuel material. These data also, are not always known or readily determined. Because of a self-protecting dose rate level of radiation (dose rate greater than 100 ren-x/h at I m in air), it is important to know the dose rate of spent fuel assemblies at all time. Estimates of the photon dose rate for spent MTR, TRIGA and DIDO-type fuel assemblies are given in this report.

  17. Novel approach to recover cobalt and lithium from spent lithium-ion battery using oxalic acid.

    PubMed

    Zeng, Xianlai; Li, Jinhui; Shen, Bingyu

    2015-09-15

    With the booming of consumer electronics (CE) and electric vehicle (EV), a large number of spent lithium-ion battery (LIBs) have been generated worldwide. Resource depletion and environmental concern driven from the sustainable industry of CE and EV have motivated spent LIBs should be recovered urgently. However, the conventional process combined with leaching, precipitating, and filtering was quite complicated to recover cobalt and lithium from spent LIBs. In this work, we developed a novel recovery process, only combined with oxalic acid leaching and filtering. When the optimal parameters for leaching process is controlled at 150 min retention time, 95 °C heating temperature, 15 g L(-1) solid-liquid ratio, and 400 rpm rotation rate, the recovery rate of lithium and cobalt from spent LIBs can reach about 98% and 97%, respectively. Additionally, we also tentatively discovered the leaching mechanism of lithium cobalt oxide (LiCoO2) using oxalic acid, and the leaching order of the sampling LiCoO2 of spent LIBs. All the obtained results can contribute to a short-cut and high-efficiency process of spent LIBs recycling toward a sound closed-loop cycle.

  18. Comparison of uranium dissolution rates from spent fuel and uranium dioxide

    SciTech Connect

    Steward, S.A.; Gray, W.J.

    1994-01-01

    Two similar sets of dissolution experiments, resulting from a statistical experimental design were performed in order to examine systematically the effects of temperature (25--75{degree}C), dissolved oxygen (0.002-0.2 atm overpressure), pH (8--10) and carbonate concentrations (2--200 {times} 10{sup {minus}4} molar) on aqueous dissolution of UO{sub 2} and spent fuel. The average dissolution rate was 8.6 mg/m{sup 2}{center_dot}day for UO{sub 2} and 3.1 mg/m{sup 2}{center_dot}day for spent fuel. This is considered to be an insignificant difference; thus, unirradiated UO{sub 2} and irradiated spent fuel dissolved at about the same rate. Moreover, regression analyses indicated that the dissolution rates of UO{sub 2} and spent fuel responded similarly to changes in pH, temperature, and carbonate concentration. However, the two materials responded very differently to dissolved oxygen concentration. Approximately half-order reaction rates with respect to oxygen concentration were found for UO{sub 2} at all conditions tested. At room temperature, spent fuel dissolution (reaction) rates were nearly independent of oxygen concentration. At 75{degree}C, reaction orders of 0.35 and 0.73 were observed for spent fuel, and there was some indication that the reaction order with respect to oxygen concentration might be dependent on pH and/or carbonate concentration as well as on temperature.

  19. Self-Paced Study Time as a Cue for Recall Predictions across School Age

    ERIC Educational Resources Information Center

    Hoffmann-Biencourt, Anja; Lockl, Kathrin; Schneider, Wolfgang; Ackerman, Rakefet; Koriat, Asher

    2010-01-01

    Recent work on metacognition indicates that monitoring is sometimes based itself on the feedback from control operations. Evidence for this pattern has not only been shown in adults but also in elementary schoolchildren. To explore whether this finding can be generalized to a wide range of age groups, 160 participants from first to eighth grade…

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

    EPA Science Inventory

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