WorldWideScience

Sample records for life span analysis

  1. Life Span Developmental Approach

    Directory of Open Access Journals (Sweden)

    Ali Eryilmaz

    2011-03-01

    Full Text Available The Life Span Developmental Approach examines development of individuals which occurs from birth to death. Life span developmental approach is a multi-disciplinary approach related with disciplines like psychology, psychiatry, sociology, anthropology and geriatrics that indicates the fact that development is not completed in adulthood, it continues during the life course. Development is a complex process that consists of dying and death. This approach carefully investigates the development of individuals with respect to developmental stages. This developmental approach suggests that scientific disciplines should not explain developmental facts only with age changes. Along with aging, cognitive, biological, and socioemotional development throughout life should also be considered to provide a reasonable and acceptable context, guideposts, and reasonable expectations for the person. There are three important subjects whom life span developmental approach deals with. These are nature vs nurture, continuity vs discontinuity, and change vs stability. Researchers using life span developmental approach gather and produce knowledge on these three most important domains of individual development with their unique scientific methodology.

  2. A Study on Engine Life Span Based on Engine Assembly Quality Analysis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the main effective factors of engine assembly quality have been analyzed in detail. It provided a mathematical model of engine life span based on the laws of the changirng of friction pairs gap and running-in analysis. On the basis of a EQ6100 engine test, the applied spectral analysis technique, it gained efficient technique measures to enhance the engine 's life span, and provided a proposal value and an allowed value of integrated position precision error.

  3. [THE ANALYSIS OF LIFE SPAN AND MORTALITY OF PATIENTS WITH SPINOCEREBELLAR ATAXIA TYPE I].

    Science.gov (United States)

    Tikhonov, D G; Goldfarb, L G; Neustroeva, T S; Yakovleva, N V; Timofeev, L F; Luckan, I P; Platonov, F A

    2015-01-01

    The article presents results of investigation of certain unclear aspects of mortality of patients with spinocerebellar ataxia type I including patients with the same number of CAG-repetitions. The analysis of mortality of patients observed from 1993 to nowadays was implemented. Sampling included 112 patients during that period 53 patients died. The comparative analysis was implemented concerning received data and results of analysis of mortality of patients died prior to 1980. According received data, average value of CAG-repetitions of normal allele was equal to 30.2, and ofpathologic allele--48.7. The average life span made up to 52.8 years, average age of disease onset--38 years and natural duration of disease--14.8 years. The analysis of life span of patients with equal length of repetitions demonstrated that range of life span of patients makes up to from 8 to 23 years. It is established that life of patients becomes shorter because of accidents, cancer and concomitant diseases of cardiovascular system. The presence of such concomitant disease as tuberculosis of lungs results in no shortening of life of patients. The comparative analysis of mortality during the period over 34 years demonstrated that age of disease onset turned out to be more conservative and stable indicator of morbidity. Despite of lacking of effective methods of treatment of disease, the natural duration of disease increased statistically reliable up to 1.8 times during period of observation. The analysis of life span ofpatients with spinocerebellar ataxia type I demonstrated that their life span except length of CAG-expansion depends on a number of factors accelerating and retarding development of disease. At that, life span of patients with the same number of CAG-repetitions can significantly differ The malignant neoplasms, diseases of cardiovascular system and external causes are to be referred to factors accelerating and retarding development of main disease. The addition oftuberculosis

  4. Social Network Changes and Life Events across the Life Span: A Meta-Analysis

    Science.gov (United States)

    Wrzus, Cornelia; Hanel, Martha; Wagner, Jenny; Neyer, Franz J.

    2013-01-01

    For researchers and practitioners interested in social relationships, the question remains as to how large social networks typically are, and how their size and composition change across adulthood. On the basis of predictions of socioemotional selectivity theory and social convoy theory, we conducted a meta-analysis on age-related social network…

  5. Social Network Changes and Life Events across the Life Span: A Meta-Analysis

    Science.gov (United States)

    Wrzus, Cornelia; Hanel, Martha; Wagner, Jenny; Neyer, Franz J.

    2013-01-01

    For researchers and practitioners interested in social relationships, the question remains as to how large social networks typically are, and how their size and composition change across adulthood. On the basis of predictions of socioemotional selectivity theory and social convoy theory, we conducted a meta-analysis on age-related social network…

  6. Materialism across the life span: An age-period-cohort analysis.

    Science.gov (United States)

    Jaspers, Esther D T; Pieters, Rik G M

    2016-09-01

    This research examined the development of materialism across the life span. Two initial studies revealed that (a) lay beliefs were that materialism declines with age and (b) previous research findings also implied a modest, negative relationship between age and materialism. Yet, previous research has considered age only as a linear control variable, thereby precluding the possibility of more intricate relationships between age and materialism. Moreover, prior studies have relied on cross-sectional data and thus confound age and cohort effects. To improve on this, the main study used longitudinal data from 8 waves spanning 9 years of over 4,200 individuals (16 to 90 years) to examine age effects on materialism while controlling for cohort and period effects. Using a multivariate multilevel latent growth model, it found that materialism followed a curvilinear trajectory across the life span, with the lowest levels at middle age and higher levels before and after that. Thus, in contrast to lay beliefs, materialism increased in older age. Moreover, age effects on materialism differed markedly between 3 core themes of materialism: acquisition centrality, possession-defined success, and acquisition as the pursuit of happiness. In particular, acquisition centrality and possession-defined success were higher at younger and older age. Independent of these age effects, older birth cohorts were oriented more toward possession-defined success, whereas younger birth cohorts were oriented more toward acquisition centrality. The economic downturn since 2008 led to a decrease in acquisition as the pursuit of happiness and in desires for personal growth, but to an increase in desires for achievement. (PsycINFO Database Record

  7. Life span of the biosphere

    Science.gov (United States)

    Lovelock, J. E.; Whitfield, M.

    1982-04-01

    Since main sequence stars appear to increase their burning rate as they age, the sun may be thought to have increased its output by 30% since the earth's origin 4.5 billion years ago. Due to the requirement for some means of planetary thermostasis in the maintenance of an equable climate since life began, possible links are considered between the biological, Gaia hypothesis of Lovelock and Margulis (1974) for climate control, and Walker et al's (in press) model of automatic thermostasis, in which the abundance of such atmospheric greenhouse gases as CO2 adjusts to resist the warming tendency of the increased solar flux. It is concluded that, since atmospheric CO2 is now close to its partial pressure lower limit, the biosphere will on a geological time-scale be soon exposed, without protection, to the predicted solar luminosity increases.

  8. Friendship and adaption across the life span

    NARCIS (Netherlands)

    Hartup, W.W.; Stevens, N.L.

    1999-01-01

    Friends foster self-esteem and a sense of well-being, socialize one another, and support one another in coping with developmental transitions and life stress. Friends engage in different activities with one another across the life span, but friendship is conceived similarly by children and adults. F

  9. Visual Search Across the Life Span

    Science.gov (United States)

    Hommel, Bernhard; Li, Karen Z. H.; Li, Shu-Chen

    2004-01-01

    Gains and losses in visual search were studied across the life span in a representative sample of 298 individuals from 6 to 89 years of age. Participants searched for single-feature and conjunction targets of high or low eccentricity. Search was substantially slowed early and late in life, age gradients were more pronounced in conjunction than in…

  10. Career development: a life span issue.

    Science.gov (United States)

    Sterns, H L; Dorsett, J G

    1994-01-01

    One of the challenges for individuals pursuing a career throughout their life span is how to maintain a high level of professional competence. As the composition of the workforce changes, and new technologies are developed, workers are faced with changing job demands and pressures. A major issue for the 1990s is how long a worker's skills will remain current. With rapid technological changes, workers may find it necessary to update continually their knowledge, skills, and abilities or risk becoming obsolete. Factors such as individuals' motivation and attitudes and organizational climate can contribute to choices regarding career development. Current research on the factors that contribute to career development activities is reviewed, along with the impact of multiple career transitions throughout the life span. Interventions such as retraining and outplacement, which allow individuals in later life to continue work, change jobs, and further develop their careers, are also discussed.

  11. Sparing of the extraocular muscles in mdx mice with absent or reduced utrophin expression: A life span analysis.

    Science.gov (United States)

    McDonald, Abby A; Hebert, Sadie L; McLoon, Linda K

    2015-11-01

    Sparing of the extraocular muscles in muscular dystrophy is controversial. To address the potential role of utrophin in this sparing, mdx:utrophin(+/-) and mdx:utrophin(-/-) mice were examined for changes in myofiber size, central nucleation, and Pax7-positive and MyoD-positive cell density at intervals over their life span. Known to be spared in the mdx mouse, and contrary to previous reports, the extraocular muscles from both the mdx:utrophin(+/-) and mdx:utrophin(-/-) mice were also morphologically spared. In the mdx:utrophin(+/)(-) mice, which have a normal life span compared to the mdx:utrophin(-/-) mice, the myofibers were larger at 3 and 12 months than the wild type age-matched eye muscles. While there was a significant increase in central nucleation in the extraocular muscles from all mdx:utrophin(+/)(-) mice, the levels were still very low compared to age-matched limb skeletal muscles. Pax7- and MyoD-positive myogenic precursor cell populations were retained and were similar to age-matched wild type controls. These results support the hypothesis that utrophin is not involved in extraocular muscle sparing in these genotypes. In addition, it appears that these muscles retain the myogenic precursors that would allow them to maintain their regenerative capacity and normal morphology over a lifetime even in these more severe models of muscular dystrophy.

  12. YODA: Software to facilitate high-throughput analysis of chronological life span, growth rate, and survival in budding yeast

    Directory of Open Access Journals (Sweden)

    Murakami Christopher J

    2010-03-01

    Full Text Available Abstract Background The budding yeast Saccharomyces cerevisiae is one of the most widely studied model organisms in aging-related science. Although several genetic modifiers of yeast longevity have been identified, the utility of this system for longevity studies has been limited by a lack of high-throughput assays for quantitatively measuring survival of individual yeast cells during aging. Results Here we describe the Yeast Outgrowth Data Analyzer (YODA, an automated system for analyzing population survival of yeast cells based on the kinetics of outgrowth measured by optical density over time. YODA has been designed specifically for quantification of yeast chronological life span, but can also be used to quantify growth rate and survival of yeast cells in response to a variety of different conditions, including temperature, nutritional composition of the growth media, and chemical treatments. YODA is optimized for use with a Bioscreen C MBR shaker/incubator/plate reader, but is also amenable to use with any standard plate reader or spectrophotometer. Conclusions We estimate that use of YODA as described here reduces the effort and resources required to measure chronological life span and analyze the resulting data by at least 15-fold.

  13. Identifying sexual differentiation genes that affect Drosophila life span

    Directory of Open Access Journals (Sweden)

    Tower John

    2009-12-01

    Full Text Available Abstract Background Sexual differentiation often has significant effects on life span and aging phenotypes. For example, males and females of several species have different life spans, and genetic and environmental manipulations that affect life span often have different magnitude of effect in males versus females. Moreover, the presence of a differentiated germ-line has been shown to affect life span in several species, including Drosophila and C. elegans. Methods Experiments were conducted to determine how alterations in sexual differentiation gene activity might affect the life span of Drosophila melanogaster. Drosophila females heterozygous for the tudor[1] mutation produce normal offspring, while their homozygous sisters produce offspring that lack a germ line. To identify additional sexual differentiation genes that might affect life span, the conditional transgenic system Geneswitch was employed, whereby feeding adult flies or developing larvae the drug RU486 causes the over-expression of selected UAS-transgenes. Results In this study germ-line ablation caused by the maternal tudor[1] mutation was examined in a long-lived genetic background, and was found to increase life span in males but not in females, consistent with previous reports. Fitting the data to a Gompertz-Makeham model indicated that the maternal tudor[1] mutation increases the life span of male progeny by decreasing age-independent mortality. The Geneswitch system was used to screen through several UAS-type and EP-type P element mutations in genes that regulate sexual differentiation, to determine if additional sex-specific effects on life span would be obtained. Conditional over-expression of transformer female isoform (traF during development produced male adults with inhibited sexual differentiation, however this caused no significant change in life span. Over-expression of doublesex female isoform (dsxF during development was lethal to males, and produced a limited

  14. Developmental Regulation across the Life Span: Toward a New Synthesis

    Science.gov (United States)

    Haase, Claudia M.; Heckhausen, Jutta; Wrosch, Carsten

    2013-01-01

    How can individuals regulate their own development to live happy, healthy, and productive lives? Major theories of developmental regulation across the life span have been proposed (e.g., dual-process model of assimilation and accommodation; motivational theory of life-span development; model of selection, optimization, and compensation), but they…

  15. Life Span and Resiliency Theory: A Critical Review

    OpenAIRE

    Alexa Smith-Osborne

    2007-01-01

    Theories of life span development describe human growth and change over the life cycle (Robbins, Chatterjee, & Canda, 2006). Major types of developmental theories include biological, psychodynamic, behavioral, and social learning, cognitive, moral, and spiritual, and those influenced by systems, empowerment, and conflict theory. Life span development theories commonly focus on ontogenesis and sequential mastery of skills, tasks, and abilities. Social work scholars have pointed out that a limi...

  16. Life spans of planktonic foraminifers: New sight through sediment traps

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Saraswat, R.; Mazumder, A.

    Maastrichtian planktic foraminifera: LIFE SPANS OF PLANKTONIC FORAMINIFERS 133 methodological comparisons, intraspecific variability, and evidence for photosynthesis. Mar. Micropal. 36: 169-188. Kawahata, II., Nishimura, A. and Gagan, M.K. 2002. Seasonal...

  17. IS LIFE-SPAN UNDER OUR CONTROL??

    Directory of Open Access Journals (Sweden)

    Parle Milind

    2011-01-01

    Full Text Available With each passing day, we age. Our body gets flooded with unwanted and deleterious elements, our cells lose their ability to divide, our nervous, endocrine and immune systems weaken with advancing age. Sagging skin, wrinkled face, graying hair, loss of muscle strength, reduced reflexes, low energy levels, increasing fat, faulty memory (dementia, weak immunity, impaired vision, defective hearing, decreased libido, cardiovascular problems and neurodegenerative disorders (like Parkinsonism and Alzheimer’s disease are the characteristic features of ageing. Leading a disease free, long life (longevity has been a dream of mankind since the arrival of human race on the planet Earth. We can not reverse the ageing process, but the features associated with ageing can be delayed in order to improve the quality of life. The present review article focuses on different theories of ageing and the anti-ageing effects of Green tea, Garlic, Turmeric, Ashwagandha, Tomato, Anwala, Ginger, Aloe and Tulsi.

  18. A CRTCal link between energy and life span.

    Science.gov (United States)

    Brunet, Anne

    2011-04-01

    Cutting down calories prolongs life, but how this works remains largely unknown. A recent study in Nature (Mair et al., 2011) shows that life span extension triggered by the energy-sensing protein kinase AMPK is mediated by an evolutionarily conserved transcriptional circuit involving CRTC-1 and CREB.

  19. Radiation effects on life span in Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, T.E.; Hartman, P.S.

    1988-09-01

    Wild-type and radiation-sensitive (Rad) mutants of Caenorhabditis elegans were irradiated using a /sup 137/Cs source (2.7 krads/min.) at several developmental stages and subsequently monitored for life span. Acute doses of radiation ranged from 1 krad to 300 krads. All stages required doses above 100 krads to reduce mean life span. Dauers and third stage larvae were more sensitive, and 8-day-old adults were the most resistant. Occasional statistically significant but nonrepeatable increases in survival were observed after intermediate levels of irradiation (10-30 krads). Unirradiated rad-4 and rad-7 had life spans similar to wild-type; all others had a significant reduction in survival. The mutants were about as sensitive as wild-type to the effects of ionizing radiation including occasional moderate life span extensions at intermediate doses. We conclude that the moderate life span extensions sometimes observed after irradiation are likely to be mediated by a means other than the induction of DNA repair enzymes.

  20. Cocoa confers life span extension in Drosophila melanogaster.

    Science.gov (United States)

    Bahadorani, Sepehr; Hilliker, Arthur J

    2008-06-01

    Cocoa is thought to be an excellent source of antioxidants. Here, we investigated the effects of cocoa supplementation on Drosophila melanogaster life span under different oxidative stress conditions. Our results illustrate that a moderate supplementation of cocoa under normoxia increases the average life span, whereas, at higher concentrations, average life span is normal. Under hyperoxia or in a Cu/Zn-superoxide dismutase-deficient background, cocoa exhibited a strong antioxidant activity, significantly increasing the average life span. Nevertheless, cocoa supplementation in a Mn-superoxide dismutase-deficient background enhanced an earlier mortality accompanied by a loss of climbing ability, indicating that cocoa may act as a pro-oxidant in mitochondria under conditions of extreme oxidative stress. Finally, we illustrate that cocoa also acts as a metal chelator in the presence of excess heavy metals, enhancing larval survival to the adult stage on copper or iron-supplemented medium. Taken together, our results document the antioxidative, pro-oxidative, and metal-chelating effects of cocoa on Drosophila melanogaster life span.

  1. Life Span and Resiliency Theory: A Critical Review

    Directory of Open Access Journals (Sweden)

    Alexa Smith-Osborne

    2007-05-01

    Full Text Available Theories of life span development describe human growth and change over the life cycle (Robbins, Chatterjee, & Canda, 2006. Major types of developmental theories include biological, psychodynamic, behavioral, and social learning, cognitive, moral, and spiritual, and those influenced by systems, empowerment, and conflict theory. Life span development theories commonly focus on ontogenesis and sequential mastery of skills, tasks, and abilities. Social work scholars have pointed out that a limitation of life span and other developmental theory is lack of attention to resilience (Greene, 2007; Robbins et al., 1998. The concept of resilience was developed to “describe relative resistance to psychosocial risk experiences” (Rutter, 1999b, p. 119. Longitudinal studies focused on typical and atypical child development informed theory formulation in developmental psychopathology (Garmezy & Rutter, 1983; Luthar, Cichetti,& Becker, 2000 and in an evolving resilience model (Richardson, 2002; Werner & Smith, 1992. Research on resilience has found a positive relationship between a number of individual traits and contextual variables and resistance to a variety of risk factors among children and adolescents. More recently, resilience research has examined the operation of these same factors in the young adult, middle-age, and elder life stages. This article examines the historical and conceptual progression of the two developmental theories—life span and resiliency—and discusses their application to social work practice and education in human behavior in the social environment.

  2. Neuromodulation of Behavioral and Cognitive Development across the Life Span

    Science.gov (United States)

    Li, Shu-Chen

    2012-01-01

    Among other mechanisms, behavioral and cognitive development entail, on the one hand, contextual scaffolding and, on the other hand, neuromodulation of adaptive neurocognitive representations across the life span. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines…

  3. Neuromodulation of Behavioral and Cognitive Development across the Life Span

    Science.gov (United States)

    Li, Shu-Chen

    2012-01-01

    Among other mechanisms, behavioral and cognitive development entail, on the one hand, contextual scaffolding and, on the other hand, neuromodulation of adaptive neurocognitive representations across the life span. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines…

  4. DIRECT SELECTION ON LIFE-SPAN IN DROSOPHILA-MELANOGASTER

    NARCIS (Netherlands)

    ZWAAN, B; BIJLSMA, R; HOEKSTRA, RE

    1995-01-01

    An important issue in the study of the evolution of aging in Drosophila melanogaster is whether decreased early fecundity is inextricably coupled with increased life span in selection experiments on age at reproduction. Here, this problem has been tackled using an experimental design in which select

  5. Women's Spirituality across the Life Span: Implications for Counseling

    Science.gov (United States)

    Briggs, Michele Kielty; Dixon, Andrea L.

    2013-01-01

    Women's spirituality has unique characteristics that are often ignored within the spirituality literature. The authors review the literature on women's spirituality to reveal the major themes women have identified as relevant to their spiritual journeys across the life span. Implications for counseling and ideas for practice are included after…

  6. DIRECT SELECTION ON LIFE-SPAN IN DROSOPHILA-MELANOGASTER

    NARCIS (Netherlands)

    ZWAAN, B; BIJLSMA, R; HOEKSTRA, RE

    An important issue in the study of the evolution of aging in Drosophila melanogaster is whether decreased early fecundity is inextricably coupled with increased life span in selection experiments on age at reproduction. Here, this problem has been tackled using an experimental design in which

  7. Paternal smoking habits affect the reproductive life span of daughters

    DEFF Research Database (Denmark)

    Fukuda, Misao; Fukuda, Kiyomi; Shimizu, Takashi

    2011-01-01

    The present study assessed whether the smoking habits of fathers around the time of conception affected the period in which daughters experienced menstrual cycles (i.e., the reproductive life span). The study revealed that the smoking habits of the farther shortened the daughters' reproductive li...

  8. Orion: a glimpse of hope in life span extension?

    Science.gov (United States)

    Muradian, K; Bondar, V; Bezrukov, V; Zhukovsky, O; Polyakov, V; Utko, N

    2010-01-01

    Orion is a multicomponent drug based on derivatives of taurocholic acid and several other compounds. Application of Orion into the feeding medium of Drosophila melanogaster resulted in increased life span and survival at stressful conditions. Two paradoxical features of the drug should be stressed: The "age-threshold" (life span extension was observed only when the drug was applied starting from the second half of life) and induction of "centenarian" flies (older 100 days). Orion enhanced survival at heat shock (38 degrees C) and acidic (pH = 1.6) or alkaline (pH = 11.8) feeding mediums, but not at oxidative stresses modeled by 100% oxygen or application of hydrogen peroxide (H(2)O(2)).

  9. Life span variations in 128 successive generations of D. melanogaster. I. Evidence that the phenomenon exists and analysis of the variations mode.

    Science.gov (United States)

    Izmaylov, D M; Obukhova, L K

    2003-05-01

    Survival of Drosophila melanogaster was estimated in 128 successive generations for 5 years. The resultant 116 samples (58 for females and 58 for males) containing series of individual values of life span (LS; 50-90 values in each series) were analyzed. Each of 58 pairs of samples belonged to a definite generation in a continuous succession where every next generation was an offspring of the preceding one. In total, 10180 Drosophila flies (5100 females and 5080 males) were studied. The mean life span (MLS) was found to be considerably heterogeneous in the series of generations: in many pairs of consecutive generations, MLSs significantly differed within two errors of the mean (Psuccessive generations of D. melanogaster. Highly significant (Psuccessive generations of the same population, with the proportions of individuals with low and high LSs remaining about the same irrespective of the MLS. It was demonstrated with the use of mathematical simulation that the MLS changes in successive generations may be regarded as an oscillatory process and described as a sum of several (three to five) harmonic components. The calculated determination coefficients were high (93.51 and 88.93% for females and males, respectively). This indicates that the mathematical model used for simulation adequately described the observed variations in MLS. The results are discussed in terms of population gerontology and the problem of geroprotector effectiveness.

  10. Childhood Self-Control and Unemployment Throughout the Life Span

    Science.gov (United States)

    Delaney, Liam; Egan, Mark; Baumeister, Roy F.

    2015-01-01

    The capacity for self-control may underlie successful labor-force entry and job retention, particularly in times of economic uncertainty. Analyzing unemployment data from two nationally representative British cohorts (N = 16,780), we found that low self-control in childhood was associated with the emergence and persistence of unemployment across four decades. On average, a 1-SD increase in self-control was associated with a reduction in the probability of unemployment of 1.4 percentage points after adjustment for intelligence, social class, and gender. From labor-market entry to middle age, individuals with low self-control experienced 1.6 times as many months of unemployment as those with high self-control. Analysis of monthly unemployment data before and during the 1980s recession showed that individuals with low self-control experienced the greatest increases in unemployment during the recession. Our results underscore the critical role of self-control in shaping life-span trajectories of occupational success and in affecting how macroeconomic conditions affect unemployment levels in the population. PMID:25870404

  11. Rapamycin extends life- and health span because it slows aging.

    Science.gov (United States)

    Blagosklonny, Mikhail V

    2013-08-01

    Making headlines, a thought-provocative paper by Neff, Ehninger and coworkers claims that rapamycin extends life span but has limited effects on aging. How is that possibly possible? And what is aging if not an increase of the probability of death with age. I discuss that the JCI paper actually shows that rapamycin slows aging and also extends lifespan regardless of its direct anti-cancer activities. Aging is, in part, MTOR-driven: a purposeless continuation of developmental growth. Rapamycin affects the same processes in young and old animals: young animals' traits and phenotypes, which continuations become hyperfunctional, harmful and lethal later in life.

  12. Homeless Aging Veterans in Transition: A Life-Span Perspective

    Directory of Open Access Journals (Sweden)

    Carla J. Thompson

    2013-01-01

    Full Text Available The need for counseling and career/educational services for homeless veterans has captured political and economic venues for more than 25 years. Veterans are three times more likely to become homeless than the general population if veterans live in poverty or are minority veterans. This mixed methods study emphasized a life-span perspective approach for exploring factors influencing normative aging and life-quality of 39 homeless veterans in Alabama and Florida. Seven descriptive quantitative and qualitative research questions framed the investigation. Study participants completed a quantitative survey reflecting their preferences and needs with a subset of the sample (N=12 also participating in individual qualitative interview sessions. Thirty-two service providers and stakeholders completed quantitative surveys. Empirical and qualitative data with appropriate triangulation procedures provided interpretive information relative to a life-span development perspective. Study findings provide evidence of the need for future research efforts to address strategies that focus on the health and economic challenges of veterans before they are threatened with the possibility of homelessness. Implications of the study findings provide important information associated with the premise that human development occurs throughout life with specific characteristics influencing the individual’s passage. Implications for aging/homelessness research are grounded in late-life transitioning and human development intervention considerations.

  13. Continuity of genetic and environmental influences on cognition across the life span: a meta-analysis of longitudinal twin and adoption studies.

    Science.gov (United States)

    Tucker-Drob, Elliot M; Briley, Daniel A

    2014-07-01

    The longitudinal rank-order stability of cognitive ability increases dramatically over the life span. Theoretical perspectives differ in their emphasis on genetic mechanisms in explaining the longitudinal stability of cognition and how stability changes with development. However, the patterns of stability of genetic and environmental influences on cognition over the life span remain poorly understood. We searched for longitudinal studies of cognition that reported raw genetically informative longitudinal correlations or parameter estimates from longitudinal behavior genetic models. We identified 150 combinations of time points and measures from 15 independent longitudinal samples. In total, longitudinal data came from 4,548 monozygotic twin pairs raised together, 7,777 dizygotic twin pairs raised together, 34 monozygotic twin pairs raised apart, 78 dizygotic twin pairs raised apart, 141 adoptive sibling pairs, and 143 nonadoptive sibling pairs, ranging in age from infancy through late adulthood. At all ages, cross-time genetic correlations and shared environmental correlations were substantially larger than cross-time nonshared environmental correlations. Cross-time correlations for genetic and shared environmental components were, respectively, low and moderate during early childhood, increased sharply over child development, and remained high from adolescence through late adulthood. Cross-time correlations for nonshared environmental components were low across childhood and gradually increased to moderate magnitudes in adulthood. Increasing phenotypic stability over child development was almost entirely mediated by genetic factors. Time-based decay of genetic and shared environmental stability was more pronounced earlier in child development. Results are interpreted in reference to theories of gene-environment correlation and interaction. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  14. The social context of managing diabetes across the life span.

    Science.gov (United States)

    Wiebe, Deborah J; Helgeson, Vicki; Berg, Cynthia A

    2016-10-01

    Diabetes self-management is crucial to maintaining quality of life and preventing long-term complications, and it occurs daily in the context of close interpersonal relationships. This article examines how social relationships are central to meeting the complex demands of managing Type I and Type 2 diabetes across the life span. The social context of diabetes management includes multiple resources, including family (parents, spouses), peers, romantic partners, and health care providers. We discuss how these social resources change across the life span, focusing on childhood and adolescence, emerging adulthood, and adulthood and aging. We review how diabetes both affects and is affected by key social relationships at each developmental period. Despite high variability in how the social context is conceptualized and measured across studies, findings converge on the characteristics of social relationships that facilitate or undermine diabetes management across the life span. These characteristics are consistent with both Interpersonal Theory and Self-Determination Theory, 2 organizing frameworks that we utilize to explore social behaviors that are related to diabetes management. Involvement and support from one's social partners, particularly family members, is consistently associated with good diabetes outcomes when characterized by warmth, collaboration, and acceptance. Underinvolvement and interactions characterized by conflict and criticism are consistently associated with poor diabetes outcomes. Intrusive involvement that contains elements of social control may undermine diabetes management, particularly when it impinges on self-efficacy. Implications for future research directions and for interventions that promote the effective use of the social context to improve diabetes self-management are discussed. (PsycINFO Database Record

  15. Evaluating the life cycle environmental impact of short span bridges

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

    impact of the construction sector. Life cycle assessment (LCA) is a systematic method for assessing the environmental impact of products and systems, but its application in bridges is scarce. In Swede, most of the bridges are short spans and the type of concrete slab-frame bridge (CFB) accounts......Bridge infrastructure consumes large amount of energy and raw materials, leading to considerable environmental burdens. The traditional infrastructure construction prioritizes its technical and economic viability. In recent years, the society devotes an ever-increased attention to the environmental...... for a large share. Soil steel composite bridge (SSCB) is a functional equivalent solution for CFB. In order to mitigate the environmental burdens of short span bridges, this paper performed a comparative LCA study between these two types of bridge. The results indicate that the initial material consumption...

  16. Inbred strains of brine shrimp derived from Artemia franciscana: lineage, RAPD analysis, life span, reproductive traits and mode, adaptation, and tolerance to salinity changes.

    Science.gov (United States)

    Nambu, Fumiko; Tanaka, Shin; Nambu, Ziro

    2007-02-01

    Inbred strains of the brine shrimp were developed from dry dormant cysts of wild-type Artemia franciscana produced in the Great Salt Lake, U.S.A. The established strains were named GSL2, 4, and 7. They were raised in 2% natural sea salt solution at 28 degrees C under a long-day condition, and fed on food sold for Artemia. Ovoviviparous offspring (free-swimming nauplii) in each brood derived from full sib (sister x brother) matings were used for succeeding generations. The ordinal number of the filial generation increased at a rate of ten generations per year. The number was over 60, and the lineage was recorded. Random amplified polymorphic DNA (RAPD) analyses of the inbred strains revealed the uniqueness, homogeneity, and genetic similarity among them. Their life span, the time required to become sexually mature, brood size, mode of reproduction, and adaptation and tolerance to salinity changes were investigated. The inbred strains usually released free-swimming nauplii rather than spawning encysted gastrulae (dormant cysts). On the other hand, the opposite results were obtained from wild-type Artemia under the same conditions. Both adults and nauplii of the inbred strains appeared to be less adaptive and less tolerant to salinity changes compared to those of the wild type. The established inbred strains should provide a wider and deeper scope for Artemia biology in particular, and the life sciences in general.

  17. The life cycle and life span of Namibian fairy circles.

    Science.gov (United States)

    Tschinkel, Walter R

    2012-01-01

    In Namibia of southwestern Africa, the sparse grasslands that develop on deep sandy soils under rainfall between 50 and 100 mm per annum are punctuated by thousands of quasi-circular bare spots, usually surrounded by a ring of taller grass. The causes of these so-called "fairy circles" are unknown, although a number of hypotheses have been proposed. This paper provides a more complete description of the variation in size, density and attributes of fairy circles in a range of soil types and situations. Circles are not permanent; their vegetative and physical attributes allow them to be arranged into a life history sequence in which circles appear (birth), develop (mature) and become revegetated (die). Occasionally, they also enlarge. The appearance and disappearance of circles was confirmed from satellite images taken 4 years apart (2004, 2008). The frequency of births and deaths as a fraction of the total population of circles allowed the calculation of an approximate turnover rate, and from this, an estimate of circle lifespan. Lifespan appeared to vary with circle size, with small circles averaging about 24 years, and larger ones 43-75 years. Overall lifespan averaged about 41 yr. A second, independent estimate of lifespan was made by revisiting circles 2 to 9 years after their clear status had been confirmed. This resulted in a lifespan estimate of about 60 years. Any causal explanation of fairy circles must include their birth, development and death, their mean lifespan and the variation of their features under different conditions.

  18. The life cycle and life span of Namibian fairy circles.

    Directory of Open Access Journals (Sweden)

    Walter R Tschinkel

    Full Text Available In Namibia of southwestern Africa, the sparse grasslands that develop on deep sandy soils under rainfall between 50 and 100 mm per annum are punctuated by thousands of quasi-circular bare spots, usually surrounded by a ring of taller grass. The causes of these so-called "fairy circles" are unknown, although a number of hypotheses have been proposed. This paper provides a more complete description of the variation in size, density and attributes of fairy circles in a range of soil types and situations. Circles are not permanent; their vegetative and physical attributes allow them to be arranged into a life history sequence in which circles appear (birth, develop (mature and become revegetated (die. Occasionally, they also enlarge. The appearance and disappearance of circles was confirmed from satellite images taken 4 years apart (2004, 2008. The frequency of births and deaths as a fraction of the total population of circles allowed the calculation of an approximate turnover rate, and from this, an estimate of circle lifespan. Lifespan appeared to vary with circle size, with small circles averaging about 24 years, and larger ones 43-75 years. Overall lifespan averaged about 41 yr. A second, independent estimate of lifespan was made by revisiting circles 2 to 9 years after their clear status had been confirmed. This resulted in a lifespan estimate of about 60 years. Any causal explanation of fairy circles must include their birth, development and death, their mean lifespan and the variation of their features under different conditions.

  19. Emotional Egocentricity Bias across the life-span

    Directory of Open Access Journals (Sweden)

    Federica eRiva

    2016-04-01

    Full Text Available In our daily lives, we often have to quickly estimate the emotions of our conspecifics in order to have successful social interactions. While this estimation process seems quite easy when we are ourselves in a neutral or equivalent emotional state, it has recently been shown that in case of incongruent emotional states between ourselves and the others, our judgments can be biased. This phenomenon, introduced to the literature with the term Emotional Egocentricity Bias (EEB, has been found to occur in young adults and, to a greater extent, in children. However, how EEB changes across the life-span from adolescence to old age has been largely unexplored. In this study, we recruited 114 female participants subdivided in four cohorts (adolescents, young adults, middle-aged adults, older adults to examine EEB age-related changes. Participants were administered with a paradigm which, by making use of visuo-tactile stimulation that elicits conflicting feelings in paired participants, allows the valid and reliable exploration of EEB. Results highlighted a U-shaped relation between age and EEB, revealing higher emotional egocentricity in adolescents and older adults compared to young and middle-aged adults. These results are in line with the neuroscientific literature which has recently shown that overcoming EEB is associated with a greater activation of a portion of the parietal lobe, namely the right Supramarginal Gyrus (rSMG. This is an area that reaches full maturation only by the end of adolescence, and displays an early decay in older age. Thus, the age-related changes of the EEB could be possibly due to the life-span development of the rSMG. This study is the first one to show the quadratic relation between age and the EEB and set a milestone for further research exploring the neural correlates of the life-span development of the EEB. Future studies are needed in order to generalize these results to the male population and to explore gender

  20. Assessment of Motor Competence Across the Life Span

    Directory of Open Access Journals (Sweden)

    Hermundur Sigmundsson

    2016-02-01

    Full Text Available In this article, the psychometric properties of a new test battery aimed at quantifying motor competence across the life span are explored. The battery was designed to be quantitative, simple to administer, applicable for large-group testing, and reliably to monitor life span motor development. A total of 638 participants between 5 and 83 years of age completed assessment of four different motor tasks (two fine and two gross motor tasks, enabling us to investigate its feasibility, internal consistency, construct validity, and test–retest reliability. Feasibility: Overall pattern of results suggest that the test battery for motor competence presented here is applicable for the age-span studied (5-83. Important consideration in this regard is that the same tasks are applied for all ages. A u-shaped curve between age and total test score indicate the adequate sensitivity of the test battery for the age range examined. Internal consistency: All individual test item scores correlated positively with the total test score with correlations ranging from .48 to .64. Correlations between scores on individual test items were moderate to high (.31-.69. The Cronbach’s alpha value for the standardized items was .79. Construct validity: Pearson correlation coefficient between total score Test of Motor Competence (TMC and Movement Assessment Battery for Children (MABC were .47 for 7- to 8-years-old children (n = 70 and .45 for 15- to 16-years-old (n = 101. Test-retest reliability: Intraclass correlation coefficients (ICCs between test and retest scores ranged from .75 to .94, and test–retest coefficient for the total score was .87.

  1. IQ and ability across the adult life span.

    Science.gov (United States)

    Baxendale, Sallie

    2011-07-01

    The experience of cognitive decline can be a potent source of anxiety and concern for many people. While an IQ consistent with estimated optimal levels or previously recorded scores may indicate no significant change in cognitive function, the patient may be accurately reporting a normal age-related deterioration in actual ability. The aim of this article is to chart the age-related changes in intellectual abilities evident on the Wechsler Adult Intelligence Scales-Fourth Edition (WAIS-IV). The norms from the WAIS-IV manual were examined to plot the age-related changes in Full-Scale IQ (FSIQ) and composite scores across the adult life span, while holding actual ability level constant across the age groups. Here we present a graphical representation of the normal cognitive developments and declines in FSIQ, Verbal Comprehension, Perceptual Reasoning, Working Memory, and Processing Speed across the adult life span. This graphical representation provides a rational basis for the identification of atypical profiles/complaints of cognitive deterioration that may require further specialist neuropsychological evaluation. These graphs can be used to provide reassurance for healthy adults with concerns of cognitive decline and as an educative tool for their referring agencies.

  2. Exercise, brain, and cognition across the life span.

    Science.gov (United States)

    Voss, Michelle W; Nagamatsu, Lindsay S; Liu-Ambrose, Teresa; Kramer, Arthur F

    2011-11-01

    This is a brief review of current evidence for the relationships between physical activity and exercise and the brain and cognition throughout the life span in non-pathological populations. We focus on the effects of both aerobic and resistance training and provide a brief overview of potential neurobiological mechanisms derived from non-human animal models. Whereas research has focused primarily on the benefits of aerobic exercise in youth and young adult populations, there is growing evidence that both aerobic and resistance training are important for maintaining cognitive and brain health in old age. Finally, in these contexts, we point out gaps in the literature and future directions that will help advance the field of exercise neuroscience, including more studies that explicitly examine the effect of exercise type and intensity on cognition, the brain, and clinically significant outcomes. There is also a need for human neuroimaging studies to adopt a more unified multi-modal framework and for greater interaction between human and animal models of exercise effects on brain and cognition across the life span.

  3. Competitiveness across the life span: the feisty fifties.

    Science.gov (United States)

    Mayr, Ulrich; Wozniak, Dave; Davidson, Casey; Kuhns, David; Harbaugh, William T

    2012-06-01

    Existing theories on life span changes in confidence or motivation suggest that individuals' preferences to enter competitive situations should gradually decline with age. We examined competitive preferences in a field experiment using real financial stakes in 25- to 75-year-olds (N = 543). The critical dependent variable was whether participants chose to perform a simple mental arithmetic task either under a piece-rate payment schedule (i.e., $.25 per solved item) or a competitive payment schedule ($.50 per solved item if the overall score is better than that of a randomly selected opponent, $0 otherwise). Results revealed that competitive preferences increased across the life span until they peaked around age 50, and dropped thereafter. We also found that throughout, men had a substantially larger preference for competing than women-extending previous findings on college-aged participants. The age/gender differences in preferences were neither accounted for by actual differences in performance nor individuals' subjective confidence. This first systematic attempt to characterize age differences in competitive behavior suggests that a simple decline conception of competitiveness needs to be reconsidered. PsycINFO Database Record (c) 2012 APA, all rights reserved

  4. Extended life-span conferred by cotransporter gene mutations in Drosophila.

    Science.gov (United States)

    Rogina, B; Reenan, R A; Nilsen, S P; Helfand, S L

    2000-12-15

    Aging is genetically determined and environmentally modulated. In a study of longevity in the adult fruit fly, Drosophila melanogaster, we found that five independent P-element insertional mutations in a single gene resulted in a near doubling of the average adult life-span without a decline in fertility or physical activity. Sequence analysis revealed that the product of this gene, named Indy (for I'm not dead yet), is most closely related to a mammalian sodium dicarboxylate cotransporter-a membrane protein that transports Krebs cycle intermediates. Indy was most abundantly expressed in the fat body, midgut, and oenocytes: the principal sites of intermediary metabolism in the fly. Excision of the P element resulted in a reversion to normal life-span. These mutations may create a metabolic state that mimics caloric restriction, which has been shown to extend life-span.

  5. Connecting Life Span Development with the Sociology of the Life Course: A New Direction.

    Science.gov (United States)

    Gilleard, Chris; Higgs, Paul

    2016-04-01

    The life course has become a topic of growing interest within the social sciences. Attempts to link this sub-discipline with life span developmental psychology have been called for but with little sign of success. In this paper, we seek to address three interlinked issues concerning the potential for a more productive interchange between life course sociology and life span psychology. The first is to try to account for the failure of these two sub-disciplines to achieve any deepening engagement with each other, despite the long-expressed desirability of that goal; the second is to draw attention to the scope for enriching the sociology of the life course through Erik Erikson's model of life span development; and the last is the potential for linking Eriksonian theory with current debates within mainstream sociology about the processes involved in 'individualisation' and 'self-reflexivity' as an alternative entry point to bring together these two fields of work.

  6. Emotional Egocentricity Bias Across the Life-Span.

    Science.gov (United States)

    Riva, Federica; Triscoli, Chantal; Lamm, Claus; Carnaghi, Andrea; Silani, Giorgia

    2016-01-01

    In our daily lives, we often have to quickly estimate the emotions of our conspecifics in order to have successful social interactions. While this estimation process seems quite easy when we are ourselves in a neutral or equivalent emotional state, it has recently been shown that in case of incongruent emotional states between ourselves and the others, our judgments can be biased. This phenomenon, introduced to the literature with the term Emotional Egocentricity Bias (EEB), has been found to occur in young adults and, to a greater extent, in children. However, how the EEB changes across the life-span from adolescence to old age has been largely unexplored. In this study, we recruited 114 female participants subdivided in four cohorts (adolescents, young adults, middle-aged adults, older adults) to examine EEB age-related changes. Participants were administered with a recently developed paradigm which, by making use of visuo-tactile stimulation that elicits conflicting feelings in paired participants, allows the valid and reliable exploration of the EEB. Results highlighted a U-shape relation between age and EEB, revealing enhanced emotional egocentricity in adolescents and older adults compared to young and middle-aged adults. These results are in line with the neuroscientific literature which has recently shown that overcoming the EEB is associated with a greater activation of a portion of the parietal lobe, namely the right Supramarginal Gyrus (rSMG). This is an area that reaches full maturation by the end of adolescence and goes through an early decay. Thus, the age-related changes of the EEB could be possibly due to the life-span development of the rSMG. This study is the first one to show the quadratic relation between age and the EEB and set a milestone for further research exploring the neural correlates of the life-span development of the EEB. Future studies are needed in order to generalize these results to the male population and to explore gender

  7. Explanations of a magic trick across the life span

    Directory of Open Access Journals (Sweden)

    Jay A Olson

    2015-03-01

    Full Text Available Studying how children and adults explain magic tricks can reveal developmental differences in cognition. We showed 167 children (aged 4 to 13 years a video of a magician making a pen vanish and asked them to explain the trick. Although most claimed to know the secret, none of them correctly identified it. The younger children provided more supernatural interpretations and more often took the magician’s actions at face value. Combined with a similar study of adults (N=1008, we found that both young children and older adults were particularly overconfident in their explanations of the trick. Our methodology demonstrates the feasibility of using magic to study cognitive development across the life span.

  8. Dendrin ablation prolongs life span by delaying kidney failure.

    Science.gov (United States)

    Weins, Astrid; Wong, Jenny S; Basgen, John M; Gupta, Ritu; Daehn, Ilse; Casagrande, Lisette; Lessman, David; Schwartzman, Monica; Meliambro, Kristin; Patrakka, Jaakko; Shaw, Andrey; Tryggvason, Karl; He, John Cijiang; Nicholas, Susanne B; Mundel, Peter; Campbell, Kirk N

    2015-08-01

    Podocyte loss is central to the progression of proteinuric kidney diseases leading to end-stage kidney disease (ESKD), requiring renal replacement therapy, such as dialysis. Despite modern tools and techniques, the 5-year mortality of some patients requiring dialysis remains at about 70% to 80%. Thus, there is a great unmet need for podocyte-specific treatments aimed at preventing podocyte loss and the ensuing development of ESKD. Here, we show that ablation of the podocyte death-promoting protein dendrin delays the onset of ESKD, thereby expanding the life span of mice lacking the adapter protein CD2AP. Ablation of dendrin delays onset and severity of proteinuria and podocyte loss. In addition, dendrin ablation ameliorates mesangial volume expansion and up-regulation of mesangial fibronectin expression, which is mediated by a podocyte-secreted factor. In conclusion, onset of ESKD and death can be markedly delayed by blocking the function of dendrin.

  9. Explanations of a magic trick across the life span

    Science.gov (United States)

    Olson, Jay A.; Demacheva, Irina; Raz, Amir

    2015-01-01

    Studying how children and adults explain magic tricks can reveal developmental differences in cognition. We showed 167 children (aged 4–13 years) a video of a magician making a pen vanish and asked them to explain the trick. Although most tried to explain the secret, none of them correctly identified it. The younger children provided more supernatural interpretations and more often took the magician's actions at face value. Combined with a similar study of adults (N = 1008), we found that both young children and older adults were particularly overconfident in their explanations of the trick. Our methodology demonstrates the feasibility of using magic to study cognitive development across the life span. PMID:25798117

  10. The Life Span Model of Suicide and Its Neurobiological Foundation

    Science.gov (United States)

    Ludwig, Birgit; Roy, Bhaskar; Wang, Qingzhong; Birur, Badari; Dwivedi, Yogesh

    2017-01-01

    The very incomprehensibility of the suicidal act has been occupying the minds of researchers and health professionals for a long time. Several theories of suicide have been proposed since the beginning of the past century, and a myriad of neurobiological studies have been conducted over the past two decades in order to elucidate its pathophysiology. Both neurobiology and psychological theories tend to work in parallel lines that need behavioral and empirical data respectively, to confirm their hypotheses. In this review, we are proposing a “Life Span Model of Suicide” with an attempt to integrate the “Stress-Diathesis Model” and the “Interpersonal Model of Suicide” into a neurobiological narrative and support it by providing a thorough compilation of related genetic, epigenetic, and gene expression findings. This proposed model comprises three layers, forming the capability of suicide: genetic factors as the predisposing Diathesis on one side and Stress, characterized by epigenetic marks on the other side, and in between gene expression and gene function which are thought to be influenced by Diathesis and Stress components. The empirical evidence of this model is yet to be confirmed and further research, specifically epigenetic studies in particular, are needed to support the presence of a life-long, evolving capability of suicide and identify its neurobiological correlates. PMID:28261051

  11. Target of rapamycin signaling regulates metabolism, growth, and life span in Arabidopsis.

    Science.gov (United States)

    Ren, Maozhi; Venglat, Prakash; Qiu, Shuqing; Feng, Li; Cao, Yongguo; Wang, Edwin; Xiang, Daoquan; Wang, Jinghe; Alexander, Danny; Chalivendra, Subbaiah; Logan, David; Mattoo, Autar; Selvaraj, Gopalan; Datla, Raju

    2012-12-01

    Target of Rapamycin (TOR) is a major nutrition and energy sensor that regulates growth and life span in yeast and animals. In plants, growth and life span are intertwined not only with nutrient acquisition from the soil and nutrition generation via photosynthesis but also with their unique modes of development and differentiation. How TOR functions in these processes has not yet been determined. To gain further insights, rapamycin-sensitive transgenic Arabidopsis thaliana lines (BP12) expressing yeast FK506 Binding Protein12 were developed. Inhibition of TOR in BP12 plants by rapamycin resulted in slower overall root, leaf, and shoot growth and development leading to poor nutrient uptake and light energy utilization. Experimental limitation of nutrient availability and light energy supply in wild-type Arabidopsis produced phenotypes observed with TOR knockdown plants, indicating a link between TOR signaling and nutrition/light energy status. Genetic and physiological studies together with RNA sequencing and metabolite analysis of TOR-suppressed lines revealed that TOR regulates development and life span in Arabidopsis by restructuring cell growth, carbon and nitrogen metabolism, gene expression, and rRNA and protein synthesis. Gain- and loss-of-function Ribosomal Protein S6 (RPS6) mutants additionally show that TOR function involves RPS6-mediated nutrition and light-dependent growth and life span in Arabidopsis.

  12. Relationship between heat shock protein 70 expression and life span in Daphnia.

    Science.gov (United States)

    Schumpert, Charles; Handy, Indhira; Dudycha, Jeffry L; Patel, Rekha C

    2014-07-01

    The longevity of an organism is directly related to its ability to effectively cope with cellular stress. Heat shock response (HSR) protects the cells against accumulation of damaged proteins after exposure to elevated temperatures and also in aging cells. To understand the role of Hsp70 in regulating life span of Daphnia, we examined the expression of Hsp70 in two ecotypes that exhibit strikingly different life spans. Daphnia pulicaria, the long lived ecotype, showed a robust Hsp70 induction as compared to the shorter lived Daphnia pulex. Interestingly, the short-lived D. pulex isolates showed no induction of Hsp70 at the mid point in their life span. In contrast to this, the long-lived D. pulicaria continued to induce Hsp70 expression at an equivalent age. We further show that the Hsp70 expression was induced at transcriptional level in response to heat shock. The transcription factor responsible for Hsp70 induction, heat shock factor-1 (HSF-1), although present in aged organisms did not exhibit DNA-binding capability. Thus, the decline of Hsp70 induction in old organisms could be attributed to a decline in HSF-1's DNA-binding activity. These results for the first time, present a molecular analysis of the relationship between HSR and life span in Daphnia. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Oxygen analyzers: failure rates and life spans of galvanic cells.

    Science.gov (United States)

    Meyer, R M

    1990-07-01

    Competing technologies exist for measuring oxygen concentrations in breathing circuits. Over a 4-year period, two types of oxygen analyzers were studied prospectively in routine clinical use to determine the incidence and nature of malfunctions. Newer AC-powered galvanic analyzers (North American Dräger O2med) were compared with older, battery-powered polarographic analyzers (Ohmeda 201) by recording all failures and necessary repairs. The AC-powered galvanic analyzer had a significantly lower incidence of failures (0.12 +/- 0.04 failures per machine-month) than the battery-powered polarographic analyzer (4.0 +/- 0.3 failures per machine-month). Disposable capsules containing the active galvanic cells lasted 12 +/- 7 months. Although the galvanic analyzers tended to remain out of service longer, awaiting the arrival of costly parts, the polarographic analyzers were more expensive to keep operating when calculations included the cost of time spent on repairs. Stocking galvanic capsules would have decreased the amount of time the galvanic analyzers were out of service, while increasing costs. In conclusion, galvanic oxygen analyzers appear capable of delivering more reliable service at a lower overall cost. By keeping the galvanic capsules exposed to room air during periods of storage, it should be possible to prolong their life span, further decreasing the cost of using them. In addition, recognizing the aberrations in their performance that warn of the exhaustion of the galvanic cells should permit timely recording and minimize downtime.

  14. Colour constancy across the life span: evidence for compensatory mechanisms.

    Science.gov (United States)

    Wuerger, Sophie

    2013-01-01

    It is well known that the peripheral visual system declines with age: the yellowing of the lens causes a selective reduction of short-wavelength light and sensitivity losses occur in the cone receptor mechanisms. At the same time, our subjective experience of colour does not change with age. The main purpose of this large-scale study (n = 185) covering a wide age range of colour-normal observers (18-75 years of age) was to assess the extent to which the human visual system is able to compensate for the changes in the optical media and at which level of processing this compensation is likely to occur. We report two main results: (1) Supra-threshold parafoveal colour perception remains largely unaffected by the age-related changes in the optical media (yellowing of the lens) whereas our ability to discriminate between small colour differences is compromised with an increase in age. (2) Significant changes in colour appearance are only found for unique green settings under daylight viewing condition which is consistent with the idea that the yellow-blue mechanism is most affected by an increase in age due to selective attenuation of short-wavelength light. The data on the invariance of hue perception, in conjunction with the age-related decline in chromatic sensitivity, provides evidence for compensatory mechanisms that enable colour-normal human observers a large degree of colour constancy across the life span. These compensatory mechanisms are likely to originate at cortical sites.

  15. SPAN - Terminal sterilization process analysis program

    Science.gov (United States)

    1969-01-01

    Computer program, SPAN, measures the dry heat thermal sterilization process applied to a planetary capsule and calculates the time required for heat application, steady state conditions, and cooling. The program is based on the logarithmic survival of micro-organisms. Temperature profiles must be input on tape.

  16. SPAN C - Terminal sterilization process analysis program

    Science.gov (United States)

    1969-01-01

    Computer program, SPAN-C, measures the dry heat thermal sterilization process applied to a planetary capsule and calculates the time required for heat application, steady state conditions, and cooling. The program is based on the logarithmic survival of micro-organisms. Temperature profiles must be input on cards.

  17. Angiotensin Converting Enzyme (ACE) Inhibitor Extends Caenorhabditis elegans Life Span.

    Science.gov (United States)

    Kumar, Sandeep; Dietrich, Nicholas; Kornfeld, Kerry

    2016-02-01

    Animal aging is characterized by progressive, degenerative changes in many organ systems. Because age-related degeneration is a major contributor to disability and death in humans, treatments that delay age-related degeneration are desirable. However, no drugs that delay normal human aging are currently available. To identify drugs that delay age-related degeneration, we used the powerful Caenorhabditis elegans model system to screen for FDA-approved drugs that can extend the adult lifespan of worms. Here we show that captopril extended mean lifespan. Captopril is an angiotensin-converting enzyme (ACE) inhibitor used to treat high blood pressure in humans. To explore the mechanism of captopril, we analyzed the acn-1 gene that encodes the C. elegans homolog of ACE. Reducing the activity of acn-1 extended the mean life span. Furthermore, reducing the activity of acn-1 delayed age-related degenerative changes and increased stress resistance, indicating that acn-1 influences aging. Captopril could not further extend the lifespan of animals with reduced acn-1, suggesting they function in the same pathway; we propose that captopril inhibits acn-1 to extend lifespan. To define the relationship with previously characterized longevity pathways, we analyzed mutant animals. The lifespan extension caused by reducing the activity of acn-1 was additive with caloric restriction and mitochondrial insufficiency, and did not require sir-2.1, hsf-1 or rict-1, suggesting that acn-1 functions by a distinct mechanism. The interactions with the insulin/IGF-1 pathway were complex, since the lifespan extensions caused by captopril and reducing acn-1 activity were additive with daf-2 and age-1 but required daf-16. Captopril treatment and reducing acn-1 activity caused similar effects in a wide range of genetic backgrounds, consistent with the model that they act by the same mechanism. These results identify a new drug and a new gene that can extend the lifespan of worms and suggest new

  18. Life Span Extension and Neuronal Cell Protection by Drosophila Nicotinamidase*S⃞

    OpenAIRE

    Balan, Vitaly; Gregory S Miller; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; Mark F A VanBerkum; Arking, Robert; Freeman, D. Carl; Maiese, Kenneth; Tzivion, Guri

    2008-01-01

    The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone ...

  19. Psychosocial stressors and the short life spans of legendary jazz musicians.

    Science.gov (United States)

    Patalano, F

    2000-04-01

    Mean age at death of 168 legendary jazz musicians and 100 renowned classical musicians were compared to examine whether psychosocial stressors such as severe substance abuse, haphazard working conditions, lack of acceptance of jazz as an art form in the United States, marital and family discord, and a vagabond life style may have contributed to shortened life spans for the jazz musicians. Analysis indicated that the jazz musicians died at an earlier age (57.2 yr.) than the classical musicians (73.3 yr.).

  20. Life-span development of self-esteem and its effects on important life outcomes.

    Science.gov (United States)

    Orth, Ulrich; Robins, Richard W; Widaman, Keith F

    2012-06-01

    We examined the life-span development of self-esteem and tested whether self-esteem influences the development of important life outcomes, including relationship satisfaction, job satisfaction, occupational status, salary, positive and negative affect, depression, and physical health. Data came from the Longitudinal Study of Generations. Analyses were based on 5 assessments across a 12-year period of a sample of 1,824 individuals ages 16 to 97 years. First, growth curve analyses indicated that self-esteem increases from adolescence to middle adulthood, reaches a peak at about age 50 years, and then decreases in old age. Second, cross-lagged regression analyses indicated that self-esteem is best modeled as a cause rather than a consequence of life outcomes. Third, growth curve analyses, with self-esteem as a time-varying covariate, suggested that self-esteem has medium-sized effects on life-span trajectories of affect and depression, small to medium-sized effects on trajectories of relationship and job satisfaction, a very small effect on the trajectory of health, and no effect on the trajectory of occupational status. These findings replicated across 4 generations of participants--children, parents, grandparents, and their great-grandparents. Together, the results suggest that self-esteem has a significant prospective impact on real-world life experiences and that high and low self-esteem are not mere epiphenomena of success and failure in important life domains. 2012 APA, all rights reserved

  1. The Rate of Source Memory Decline across the Adult Life Span

    Science.gov (United States)

    Cansino, Selene; Estrada-Manilla, Cinthya; Hernandez-Ramos, Evelia; Martinez-Galindo, Joyce Graciela; Torres-Trejo, Frine; Gomez-Fernandez, Tania; Ayala-Hernandez, Mariana; Osorio, David; Cedillo-Tinoco, Melisa; Garces-Flores, Lissete; Gomez-Melgarejo, Sandra; Beltran-Palacios, Karla; Guadalupe Garcia-Lazaro, Haydee; Garcia-Gutierrez, Fabiola; Cadena-Arenas, Yadira; Fernandez-Apan, Luisa; Bartschi, Andrea; Resendiz-Vera, Julieta; Rodriguez-Ortiz, Maria Dolores

    2013-01-01

    Previous studies have suggested that the ability to remember contextual information related to specific episodic experiences declines with advancing age; however, the exact moment in the adult life span when this deficit begins is still controversial. Source memory for spatial information was tested in a life span sample of 1,500 adults between…

  2. The Rate of Source Memory Decline across the Adult Life Span

    Science.gov (United States)

    Cansino, Selene; Estrada-Manilla, Cinthya; Hernandez-Ramos, Evelia; Martinez-Galindo, Joyce Graciela; Torres-Trejo, Frine; Gomez-Fernandez, Tania; Ayala-Hernandez, Mariana; Osorio, David; Cedillo-Tinoco, Melisa; Garces-Flores, Lissete; Gomez-Melgarejo, Sandra; Beltran-Palacios, Karla; Guadalupe Garcia-Lazaro, Haydee; Garcia-Gutierrez, Fabiola; Cadena-Arenas, Yadira; Fernandez-Apan, Luisa; Bartschi, Andrea; Resendiz-Vera, Julieta; Rodriguez-Ortiz, Maria Dolores

    2013-01-01

    Previous studies have suggested that the ability to remember contextual information related to specific episodic experiences declines with advancing age; however, the exact moment in the adult life span when this deficit begins is still controversial. Source memory for spatial information was tested in a life span sample of 1,500 adults between…

  3. Genomic instability is associated with natural life span variation in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Hong Qin

    Full Text Available Increasing genomic instability is associated with aging in eukaryotes, but the connection between genomic instability and natural variation in life span is unknown. We have quantified chronological life span and loss-of-heterozygosity (LOH in 11 natural isolates of Saccharomyces cerevisiae. We show that genomic instability increases and mitotic asymmetry breaks down during chronological aging. The age-dependent increase of genomic instability generally lags behind the drop of viability and this delay accounts for approximately 50% of the observed natural variation of replicative life span in these yeast isolates. We conclude that the abilities of yeast strains to tolerate genomic instability co-vary with their replicative life spans. To the best of our knowledge, this is the first quantitative evidence that demonstrates a link between genomic instability and natural variation in life span.

  4. Life span, reproductive output, and reproductive opportunity in captive Goeldi's monkeys (Callimico goeldii).

    Science.gov (United States)

    Nuss, Kara; Warneke, Mark

    2010-01-01

    In the absence of long-term field studies, demographic and reproductive records from animals housed in zoos and research laboratories are a valuable tool for the study of life history variables relating to reproduction. In this study, we analyzed studbook records of more than 2,000 individuals born over a 40-year period (1965-2004) to describe life history patterns of captive Goeldi's monkeys (Callimico goeldii) housed in North America and Europe. Using Kaplan-Meier survival analysis methods, we found the mean life span to be 5.5 years. The rate of infant mortality, defined as death before 30 days, was approximately 30%, with European animals being more likely to survive infancy than North American animals. When individuals surviving at least 1.5 years are considered, lifetime reproductive output averaged 3.5 offspring, yet more than one-third of individuals did not produce any offspring. Using a smaller dataset of individuals with known pairing histories, we developed a measure of opportunity for reproduction (OFR), which represented the total time an individual was known to be housed with a potential mate. For both sexes, we found that the correlation between OFR and number of offspring produced was much higher than the correlation between life span and number of offspring produced. This result highlights the importance of taking into account an individual's OFR. As a whole, our findings help characterize the life histories of captive Goeldi's monkeys and emphasize the impact management practices may have on reproductive success.

  5. Blade life span, structural investment, and nutrient allocation in giant kelp.

    Science.gov (United States)

    Rodriguez, Gabriel E; Reed, Daniel C; Holbrook, Sally J

    2016-10-01

    The turnover of plant biomass largely determines the amount of energy flowing through an ecosystem and understanding the processes that regulate turnover has been of interest to ecologists for decades. Leaf life span theory has proven useful in explaining patterns of leaf turnover in relation to resource availability, but the predictions of this theory have not been tested for macroalgae. We measured blade life span, size, thickness, nitrogen content, pigment content, and maximum photosynthetic rate (P max) in the giant kelp (Macrocystis pyrifera) along a strong resource (light) gradient to test whether the predictions of leaf life span theory applied to this alga. We found that shorter blade life spans and larger blade areas were associated with increased light availability. In addition, nitrogen and P max decreased with blade age, and their decrease was greater in shorter lived blades. These observations are generally consistent with patterns observed for higher plants and the prevailing theory of leaf life span. By contrast, variation observed in pigments of giant kelp was inconsistent with that predicted by leaf life span theory, as blades growing in the most heavily shaded portion of the forest had the lowest chlorophyll content. This result may reflect the dual role of macroalgal blades in carbon fixation and nutrient absorption and the ability of giant kelp to modify blade physiology to optimize the acquisition of light and nutrients. Thus, the marine environment may place demands on resource acquisition and allocation that have not been previously considered with respect to leaf life span optimization.

  6. Ageless and Timeless: Perspectives on Giftedness across the Life Span

    Science.gov (United States)

    Fiedler, Ellen D.

    2016-01-01

    Annemarie Roeper's timeless perspectives were demonstrated throughout her long and productive life. Her prolific writings and speeches continue to influence our understanding of giftedness at all ages and stages of life, and the time I spent with her had a profound and meaningful effect on my work. Annemarie incorporated her inner view of…

  7. Ageless and Timeless: Perspectives on Giftedness across the Life Span

    Science.gov (United States)

    Fiedler, Ellen D.

    2016-01-01

    Annemarie Roeper's timeless perspectives were demonstrated throughout her long and productive life. Her prolific writings and speeches continue to influence our understanding of giftedness at all ages and stages of life, and the time I spent with her had a profound and meaningful effect on my work. Annemarie incorporated her inner view of…

  8. Life-span plasticity of the brain and cognition: from questions to evidence and back.

    Science.gov (United States)

    Raz, Naftali; Lindenberger, Ulman

    2013-11-01

    Experience-related changes induced by modification of environment, physical exercise, or cognitive training affect brain structure and function. Research on brain plasticity and its relationship to experiential changes gathers momentum and attracts significant public interest. This collection of papers is based on presentation at the First International Conference on Life-Span Plasticity of Brain and Behavior: A Cognitive Neuroscience Perspective that took place in Detroit, MI, on October 12-14, 2011. The conference honored Margret M. and Paul B. Baltes, the pioneers of life-span developmental psychology who initiated some of the first studies on experience- and training-related changes in cognition across the life span.

  9. Mathematical Basis of Idea That Harmonious Marriage Can Lengthen Life-span

    Institute of Scientific and Technical Information of China (English)

    Zhi-qiang Zhang

    2009-01-01

    It is a very important issue for us to explore the effects of the marriage to life. In recent years, many scholars have proved that the marriage can lengthen life-span from different angles. With the development of theory of dependence random variables, we discuss the effects of the marriage to life and provide a mathematical basis of the idea that the harmonious marriage can lengthen life-span in this paper. Meanwhile, we analyze the impact of the marriage on life on the basis of the net single premium.

  10. Life span of common marmoset (Callithrix jacchus) at CLEA Japan breeding colony.

    Science.gov (United States)

    Nishijima, Kazutoshi; Saitoh, Ryoichi; Tanaka, Shin; Ohsato-Suzuki, Motoko; Ohno, Tamio; Kitajima, Shuji

    2012-08-01

    The life span and survival parameters of the common marmoset (Callithrix jacchus) in a breeding colony at CLEA Japan, Inc. were investigated. The average life span of male marmosets was 148.5 ± 6.1 (mean ± SE) months of age (M), which was significantly longer (P marmosets show a slight decline in survival during the first 7-9 years and then a dramatic decrease and another slight decline after 14-16 year of age in survival, i.e., a lifespan curve similar to what is observed in colonies of aging rodents and humans. The sex-associated difference in life span was caused by reproductive burden on the females. The present study reported a longer than expected life span of the marmoset, and a long-lived animal can be a powerful model for senescence and longevity sciences.

  11. Environmental Canalization of Life Span and Gene Expression in Caenorhabditis elegans.

    Science.gov (United States)

    Mendenhall, Alexander; Crane, Matthew M; Leiser, Scott; Sutphin, George; Tedesco, Patricia M; Kaeberlein, Matt; Johnson, Thomas E; Brent, Roger

    2017-08-01

    Animals, particularly poikilotherms, exhibit distinct physiologies at different environmental temperatures. Here, we hypothesized that temperature-based differences in physiology could affect the amount of variation in complex quantitative traits. Specifically, we examined, in Caenorhabditis elegans, how different temperatures (15°C, 20°C, and 25°C) affected the amount of interindividual variation in life span and also expression of three reporter genes-transcriptional reporters for vit-2, gpd-2, and hsp-16.2 (a life-span biomarker). We found the expected inverse relationship between temperature and average life span. Surprisingly, we found that at the highest temperature, there were fewer differences between individuals in life span and less interindividual variation in expression of all three reporters. We suggest that growth at 25°C might canalize (reduce interindividual differences in) life span and expression of some genes by eliciting a small constitutive heat shock response. Growth at 25°C requires wild-type hsf-1, which encodes the main heat shock response transcriptional activator. We speculate that increased chaperone activity at 25°C may reduce interindividual variation in gene expression by increasing protein folding efficiency. We hypothesize that reduced variation in gene expression may ultimately cause reduced variation in life span. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Exposure To Harmful Workplace Practices Could Account For Inequality In Life Spans Across Different Demographic Groups.

    Science.gov (United States)

    Goh, Joel; Pfeffer, Jeffrey; Zenios, Stefanos

    2015-10-01

    The existence of important socioeconomic disparities in health and mortality is a well-established fact. Many pathways have been adduced to explain inequality in life spans. In this article we examine one factor that has been somewhat neglected: People with different levels of education get sorted into jobs with different degrees of exposure to workplace attributes that contribute to poor health. We used General Social Survey data to estimate differential exposures to workplace conditions, results from a meta-analysis that estimated the effect of workplace conditions on mortality, and a model that permitted us to estimate the overall effects of workplace practices on health. We conclude that 10-38 percent of the difference in life expectancy across demographic groups can be explained by the different job conditions their members experience.

  13. Herbal supplement extends life span under some environmental conditions and boosts stress resistance.

    Directory of Open Access Journals (Sweden)

    Bryant Villeponteau

    Full Text Available Genetic studies indicate that aging is modulated by a great number of genetic pathways. We have used Drosophila longevity and stress assays to test a multipath intervention strategy. To carry out this strategy, we supplemented the flies with herbal extracts (SC100 that are predicted to modulate the expression of many genes involved in aging and stress resistance, such as mTOR, NOS, NF-KappaB, and VEGF. When flies were housed in large cages with SC100 added, daily mortality rates of both male and female flies were greatly diminished in mid to late life. Surprisingly, SC100 also stabilized midlife mortality rate increases so as to extend the maximum life span substantially beyond the limits previously reported for D. melanogaster. Under these conditions, SC100 also promoted robust resistance to partial starvation stress and to heat stress. Fertility was the same initially in both treated and control flies, but it became significantly higher in treated flies at older ages as the fertility of control flies declined. Mean and maximum life spans of flies in vials at the same test site were also extended by SC100, but the life spans were short in absolute terms. In contrast, at an independent test site where stress was minimized, the flies exhibited much longer mean life spans, but the survival curves became highly rectangular and the effects of SC100 on both mean and maximum life spans declined greatly or were abolished. The data indicate that SC100 is a novel herbal mix with striking effects on enhancing Drosophila stress resistance and life span in some environments, while minimizing mid to late life mortality rates. They also show that the environment and other factors can have transformative effects on both the length and distribution of survivorship, and on the ability of SC100 to extend the life span.

  14. 'Willpower' over the life span: decomposing self-regulation.

    Science.gov (United States)

    Mischel, Walter; Ayduk, Ozlem; Berman, Marc G; Casey, B J; Gotlib, Ian H; Jonides, John; Kross, Ethan; Teslovich, Theresa; Wilson, Nicole L; Zayas, Vivian; Shoda, Yuichi

    2011-04-01

    In the 1960s, Mischel and colleagues developed a simple 'marshmallow test' to measure preschoolers' ability to delay gratification. In numerous follow-up studies over 40 years, this 'test' proved to have surprisingly significant predictive validity for consequential social, cognitive and mental health outcomes over the life course. In this article, we review key findings from the longitudinal work and from earlier delay-of-gratification experiments examining the cognitive appraisal and attention control strategies that underlie this ability. Further, we outline a set of hypotheses that emerge from the intersection of these findings with research on 'cognitive control' mechanisms and their neural bases. We discuss implications of these hypotheses for decomposing the phenomena of 'willpower' and the lifelong individual differences in self-regulatory ability that were identified in the earlier research and that are currently being pursued.

  15. Life-span adjustment of children to their parents' divorce.

    Science.gov (United States)

    Amato, P R

    1994-01-01

    Children who experience parental divorce, compared with children in intact two-parent families, exhibit more conduct problems, more symptoms of psychological maladjustment, lower academic achievement, more social difficulties, and poorer self-concepts. Similarly, adults who experienced parental divorce as children, compared with adults raised in continuously intact two-parent families, score lower on a variety of indicators of psychological, interpersonal, and socioeconomic well-being. However, the overall group differences between offspring from divorced and intact families are small, with considerable diversity existing in children's reactions to divorce. Children's adjustment to divorce depends on several factors, including the amount and quality of contact with noncustodial parents, the custodial parents' psychological adjustment and parenting skills, the level of interparental conflict that precedes and follows divorce, the degree of economic hardship to which children are exposed, and the number of stressful life events that accompany and follow divorce. These factors can be used as guides to assess the probable impact of various legal and therapeutic interventions to improve the well-being of children of divorce.

  16. Increased Life Span due to Calorie Restriction in Respiratory-Deficient Yeast.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available A model for replicative life span extension by calorie restriction (CR in yeast has been proposed whereby reduced glucose in the growth medium leads to activation of the NAD-dependent histone deacetylase Sir2. One mechanism proposed for this putative activation of Sir2 is that CR enhances the rate of respiration, in turn leading to altered levels of NAD or NADH, and ultimately resulting in enhanced Sir2 activity. An alternative mechanism has been proposed in which CR decreases levels of the Sir2 inhibitor nicotinamide through increased expression of the gene coding for nicotinamidase, PNC1. We have previously reported that life span extension by CR is not dependent on Sir2 in the long-lived BY4742 strain background. Here we have determined the requirement for respiration and the effect of nicotinamide levels on life span extension by CR. We find that CR confers robust life span extension in respiratory-deficient cells independent of strain background, and moreover, suppresses the premature mortality associated with loss of mitochondrial DNA in the short-lived PSY316 strain. Addition of nicotinamide to the medium dramatically shortens the life span of wild type cells, due to inhibition of Sir2. However, even in cells lacking both Sir2 and the replication fork block protein Fob1, nicotinamide partially prevents life span extension by CR. These findings (1 demonstrate that respiration is not required for the longevity benefits of CR in yeast, (2 show that nicotinamide inhibits life span extension by CR through a Sir2-independent mechanism, and (3 suggest that CR acts through a conserved, Sir2-independent mechanism in both PSY316 and BY4742.

  17. If started early in life, metformin treatment increases life span and postpones tumors in female SHR mice

    Science.gov (United States)

    Anisimov, Vladimir N.; Berstein, Lev M.; Popovich, Irina G.; Zabezhinski, Mark A.; Egormin, Peter A.; Piskunova, Tatiana S.; Semenchenko, Anna V.; Tyndyk, Margarita L.; Yurova, Maria N.; Kovalenko, Irina G.; Poroshina, Tatiana E.

    2011-01-01

    Hyperglycemia and hyperinsulinemia accelerate both aging and cancer. Antidiabetic biguanides such as metformin decrease glucose, insulin and IGF-1 level. Metformin increases lifespan and prevents cancer in mice, although its effects vary, depending on mice strain and gender. Here we showed that chronic treatment of female outbred SHR mice with metformin started at the age of 3, 9 or 15 months decreased body temperature and postponed age-related switch-off of estrous function. Surprisingly, metformin did not affect levels of serum cholesterol, triglycerides, glucose and insulin. Treatment with metformin started at the age of 3 months increased mean life span by 14% and maximum life span by 1 month. The treatment started at the age of 9 months insignificantly increased mean life span by only 6%, whereas the treatment started at the age of 15 months failed to increase life span. The mean life span of tumor-free mice was increased by 21% in ‘the youngest group’, by 7% in ‘middle-aged group’ and in contrast was reduced by 13% in ‘the oldest group’. When started at the age of 3 and 9 months, metformin delayed the first tumor detection by 22% and 25%, correspondingly. Thus, in female SHR mice, metformin increased life span and postponed tumors when started at the young and middle but not at the old age. In contrast, metformin improves reproductive function when started at any age. PMID:21386129

  18. Advanced aerostatic analysis of long-span suspension bridges

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the wind speed spatial non-uniformity all increase consequently, which may have unnegligible influence on the aerostatic behavior of long-span suspension bridges. In this work, a method of advanced aerostatic analysis is presented firstly by considering the geometric nonlinearity, the nonlinear wind-structures and wind speed spatial non-uniformity. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic behavior of the bridge are investigated analytically. The results showed that these factors all have important influence on the aerostatic behavior, and should be considered in the aerostatic analysis of long and particularly super long-span suspension bridges.

  19. Stability of self-esteem across the life span.

    Science.gov (United States)

    Trzesniewski, Kali H; Donnellan, M Brent; Robins, Richard W

    2003-01-01

    Two studies examined the rank-order stability of self-esteem from age 6 to 83: Study 1 was a meta-analysis of 50 published articles (N = 29,839) and Study 2 analyzed data from 4 large national studies (N = 74,381). Self-esteem showed substantial continuity over time (disattenuated correlations ranged from the .50s to .70s), comparable to the stability found for personality traits. Both studies provided evidence for a robust developmental trend: Self-esteem stability was low during childhood, increased throughout adolescence and young adulthood, and declined during midlife and old age. This trend could not be explained by age differences in the reliability of self-esteem measures, and generally replicated across gender, ethnicity, self-esteem scale, nationality (U.S. vs. non-U.S.), and year of publication.

  20. Life Span and Motility Effects of Ethanolic Extracts from Sophora moorcroftiana Seeds on Caenorhabditis elegans

    Science.gov (United States)

    Li, Xin; Han, Junxian; Zhu, Rongyan; Cui, Rongrong; Ma, Xingming; Dong, Kaizhong

    2016-01-01

    Background: Sophora moorcroftiana is an endemic shrub species with a great value in folk medicine in Tibet, China. In this study, relatively little is known about whether S. moorcroftiana is beneficial in animals' nervous system and life span or not. Materials and Methods: To address this question, under survival normal temperature (25°C), S. moorcroftiana seeds were extracted with 95% ethanol, and Caenorhabditis elegans were exposed to three different extract concentrations (100 mg/L, 200 mg/L, and 400 mg/mL) from S. moorcroftiana seeds. Results: The 95% ethanolic extracts from S. moorcroftiana seeds could increase life span and slow aging-related increase in C. elegans and could not obviously influence the motility of C. elegans. Conclusion: Given these results by our experiment for life span and motility with 95% ethanolic extracts from S. moorcroftiana seeds in C. elegans, the question whether S. moorcroftiana acts as an anti-aging substance in vivo arises. SUMMARY The 95% ethanolic extracts from S. moorcroftiana seeds have no effect on the life span in C. elegans when extract concentrations from S. moorcroftiana seeds <400 mg/LThe 400 mg/L 95% ethanolic extracts from S. moorcroftiana seeds could increase life span in C. elegansThe 95% ethanolic extracts from S. moorcroftiana seeds could not obviously influence the motility in C. elegans. Abbreviation used: S. moorcroftiana: Sophora moorcroftiana; C. elegan: Caenorhabditis elegan; E. coli OP50: Escherichia coli OP50; DMSO: Dimethyl sulfoxide. PMID:27279712

  1. Nutrition research to affect food and a healthy life span.

    Science.gov (United States)

    Ohlhorst, Sarah D; Russell, Robert; Bier, Dennis; Klurfeld, David M; Li, Zhaoping; Mein, Jonathan R; Milner, John; Ross, A Catharine; Stover, Patrick; Konopka, Emily

    2013-08-01

    Proper nutrition offers one of the most effective and least costly ways to decrease the burden of many diseases and their associated risk factors, including obesity. Nutrition research holds the key to increasing our understanding of the causes of obesity and its related comorbidities and thus holds promise to markedly influence global health and economies. After outreach to 75 thought leaders, the American Society for Nutrition (ASN) convened a Working Group to identify the nutrition research needs whose advancement will have the greatest projected impact on the future health and well-being of global populations. ASN's Nutrition Research Needs focus on the following high priority areas: 1) variability in individual responses to diet and foods; 2) healthy growth, development, and reproduction; 3) health maintenance; 4) medical management; 5) nutrition-related behaviors; and 6) food supply/environment. ASN hopes the Nutrition Research Needs will prompt collaboration among scientists across all disciplines to advance this challenging research agenda given the high potential for translation and impact on public health. Furthermore, ASN hopes the findings from the Nutrition Research Needs will stimulate the development and adoption of new and innovative strategies that can be applied toward the prevention and treatment of nutrition-related diseases. The multidisciplinary nature of nutrition research requires stakeholders with differing areas of expertise to collaborate on multifaceted approaches to establish the evidence-based nutrition guidance and policies that will lead to better health for the global population. In addition to the identified research needs, ASN also identified 5 tools that are critical to the advancement of the Nutrition Research Needs: 1) omics, 2) bioinformatics, 3) databases, 4) biomarkers, and 5) cost-effectiveness analysis.

  2. "Aging out" of violence: the multiple faces of intimate violence over the life span.

    Science.gov (United States)

    Band-Winterstein, Tova; Eisikovits, Zvi

    2009-02-01

    In this article, we explore how continuous intimate partner violence is experienced in old age and how age and violence interact and change throughout the life span. This is a qualitative study based on a phenomenological perspective focusing on the lived experiences of the elderly who have dwelled in domestic violence most of their lives. The sample consisted of 40 informants. In-depth, semistructured interviews were performed. Content analysis of the interviews yielded four clusters of living in violence over time: (a) The arena of violence is alive and active, (b) violence is in the air, (c) more of the same but differently, and (d) violence through illness to the very end. These clusters are discussed and their implications for practice are suggested.

  3. [The traits theory in longitudinal life span research. Partial report of a workshop].

    Science.gov (United States)

    Munnichs, J M

    1982-12-01

    During the international Workshop on 'Life Span and Change in a Gerontological Perspective' (9-12 July, 1981) at the University of Nijmegen, the Netherlands, research data from the Oakland Growth Study and the Guidance Study have been discussed. The second major contribution came from the longitudinal studies at the Bonn University. These groups of researchers cover different periods in the life span, but both contribute to prediction and understanding of periods not under investigation. Each of these longitudinal studies can contribute to the total understanding of the psychology of the life span. In this contribution we describe the trait-centered approach. The older research is mostly done with this theoretical approach in mind. We summarize the Californian studies and the Manhattan study on mental health. We close with some general critical remarks and we try to define the limitations of the trait-theoretical approach.

  4. Longevity in space; experiment on the life span of Paramecium cell clone in space.

    Science.gov (United States)

    Mogami, Y; Tokunaga, N; Baba, S A

    1999-01-01

    Life span is the most interesting and also the most important biologically relevant time to be investigated on the space station. As a model experiment, we proposed an investigation to assess the life span of clone generation of the ciliate Paramecium. In space, clone generation will be artificially started by conjugation or autogamy, and the life span of the cell populations in different gravitational fields (microgravity and onboard 1 x g control) will be precisely assessed in terms of fission age as compared with the clock time. In order to perform the space experiment including long-lasting culture and continuous measurement of cell division, we tested the methods of cell culture and of cell-density measurement, which will be available in closed environments under microgravity. The basic design of experimental hardware and a preliminary result of the cultivation procedure are described. c1999 COSPAR. Published by Elsevier Science Ltd.

  5. Tequila Regulates Insulin-Like Signaling and Extends Life Span in Drosophila melanogaster.

    Science.gov (United States)

    Huang, Cheng-Wen; Wang, Horng-Dar; Bai, Hua; Wu, Ming-Shiang; Yen, Jui-Hung; Tatar, Marc; Fu, Tsai-Feng; Wang, Pei-Yu

    2015-12-01

    The aging process is a universal phenomenon shared by all living organisms. The identification of longevity genes is important in that the study of these genes is likely to yield significant insights into human senescence. In this study, we have identified Tequila as a novel candidate gene involved in the regulation of longevity in Drosophila melanogaster. We have found that a hypomorphic mutation of Tequila (Teq(f01792)), as well as cell-specific downregulation of Tequila in insulin-producing neurons of the fly, significantly extends life span. Tequila deficiency-induced life-span extension is likely to be associated with reduced insulin-like signaling, because Tequila mutant flies display several common phenotypes of insulin dysregulation, including reduced circulating Drosophila insulin-like peptide 2 (Dilp2), reduced Akt phosphorylation, reduced body size, and altered glucose homeostasis. These observations suggest that Tequila may confer life-span extension by acting as a modulator of Drosophila insulin-like signaling.

  6. Families enriched for exceptional longevity also have increased health span: Findings from the Long Life Family Study

    Directory of Open Access Journals (Sweden)

    Paola eSebastiani

    2013-09-01

    Full Text Available Hypothesizing that members of families enriched for longevity delay morbidity compared to population controls and approximate the health-span of centenarians, we compared the health spans of older generation subjects of the Long Life Family Study (LLFS to controls without family history of longevity and to centenarians of the New England Centenarian Study (NECS using Bayesian parametric survival analysis. We estimated hazard ratios, the ages at which specific percentiles of subjects had onsets of diseases, and the gain of years of disease-free survival in the different cohorts compared to referent controls. Compared to controls, LLFS subjects had lower hazards for cancer, cardiovascular disease, severe dementia, diabetes, hypertension, osteoporosis and stroke. The age at which 20% of the LLFS siblings and probands had one or more age-related diseases was approximately 10 years later than NECS controls. While female NECS controls generally delayed the onset of age-related diseases compared with males controls, these gender differences became much less in the older generation of the LLFS and disappeared amongst the centenarians of the NECS. The analyses demonstrate extended health-span in the older subjects of the LLFS and suggest that this aging cohort provides an important resource to discover genetic and environmental factors that promote prolonged health-span in addition to longer life-span.

  7. A bodyweight-dependent allometric exponent for scaling clearance across the human life-span

    NARCIS (Netherlands)

    C. Wang (Chenguang); M.Y. Peeters (Mariska); K. Allegaert (Karel); H.J. Blussé van Oud-Alblas (Heleen); E.H.J. Krekels (Elke); D. Tibboel (Dick); M. Danhof (Meindert); C.A.J. Knibbe (Catherijne)

    2012-01-01

    textabstractPurpose: To explore different allometric equations for scaling clearance across the human life-span using propofol as a model drug. Methods: Data from seven previously published propofol studies ((pre)term neonates, infants, toddlers, children, adolescents and adults) were analysed using

  8. A bodyweight-dependent allometric exponent for scaling clearance across the human life-span

    NARCIS (Netherlands)

    C. Wang (Chenguang); M.Y. Peeters (Mariska); K. Allegaert (Karel); H.J. Blussé van Oud-Alblas (Heleen); E.H.J. Krekels (Elke); D. Tibboel (Dick); M. Danhof (Meindert); C.A.J. Knibbe (Catherijne)

    2012-01-01

    textabstractPurpose: To explore different allometric equations for scaling clearance across the human life-span using propofol as a model drug. Methods: Data from seven previously published propofol studies ((pre)term neonates, infants, toddlers, children, adolescents and adults) were analysed using

  9. Toward a Life Span Theory of Close Relationships: The Affective Relationships Model

    Science.gov (United States)

    Takahashi, Keiko

    2005-01-01

    This article addresses how close relationships can be conceptualized so that they can be accurately understood over the life span. First, two typical clusters of theories of close relationships, the attachment theory and the social network theory, are compared and discussed with regard to their fundamental but controversial assumptions regarding…

  10. Investigating the life-span of cork products through a longitudinal approach with users- Interim results

    NARCIS (Netherlands)

    Da Silva Pereira, A.C.; Brezet, J.C.; Pereira, H.; Vogtlander, J.G.

    2012-01-01

    Products with long life-spans are generally preferred form an environmental perspective. This paper addresses the longevity of cork products, and the respective influencing aspects. This is accomplished through a longitudinal study where several cork products are used, and at different moments in ti

  11. The Status of Number and Quantity Conservation Concepts Across the Life-span.

    Science.gov (United States)

    Papalia, Diane E.

    Conservation performance during childhood to portions of the life span beyond adolescence is examined, with existing data replicated on subjects ranging from the preschool to middle-childhood years. Age differences in performance are studied for the typical Piagetian paired-stimulus equivalence conservation of number, substance, weight, and volume…

  12. Female Early Adolescent Sex Role Attitude and Behavior Development: A Life Span, Ecosystem Approach.

    Science.gov (United States)

    Nelson, Christine Seipke; Keith, Joanne

    Theory and research related to early adolescent sex role development needs to be addressed from both a life-span and an ecological perspective. A study was conducted to examine the development of female early adolescent sex role attitudes and behaviors in an ecological context as defined by Urie Bronfenbrenner. Data were the results of a…

  13. Body Image across the Life Span in Adult Women: The Role of Self-Objectification.

    Science.gov (United States)

    Tiggemann, Marika; Lynch, Jessica E.

    2001-01-01

    Investigated body image across life span in cross-section of women ages 20-84 years. Found that although body dissatisfaction remained stable, self-objectification, habitual body monitoring, appearance anxiety, and disordered eating all significantly decreased with age. Self- objectification mediated the relationship between age and disordered…

  14. Attachment and the Processing of Social Information across the Life Span: Theory and Evidence

    Science.gov (United States)

    Dykas, Matthew J.; Cassidy, Jude

    2011-01-01

    Researchers have used J. Bowlby's (1969/1982, 1973, 1980, 1988) attachment theory frequently as a basis for examining whether experiences in close personal relationships relate to the processing of social information across childhood, adolescence, and adulthood. We present an integrative life-span-encompassing theoretical model to explain the…

  15. Asynchronous Vowel-Pair Identification across the Adult Life Span for Monaural and Dichotic Presentations

    Science.gov (United States)

    Fogerty, Daniel; Kewley-Port, Diane; Humes, Larry E.

    2012-01-01

    Purpose: Temporal order abilities decrease with age. Declining temporal processing abilities may influence the identification of rapid vowel sequences. Identification patterns for asynchronous vowel pairs were explored across the life span. Method: Young, middle-aged, and older listeners completed temporal order tasks for pairs of 70-ms and 40-ms…

  16. Caenorhabditis elegans Genes Affecting Interindividual Variation in Life-span Biomarker Gene Expression.

    Science.gov (United States)

    Mendenhall, Alexander; Crane, Matthew M; Tedesco, Patricia M; Johnson, Thomas E; Brent, Roger

    2017-10-01

    Genetically identical organisms grown in homogenous environments differ in quantitative phenotypes. Differences in one such trait, expression of a single biomarker gene, can identify isogenic cells or organisms that later manifest different fates. For example, in isogenic populations of young adult Caenorhabditis elegans, differences in Green Fluorescent Protein (GFP) expressed from the hsp-16.2 promoter predict differences in life span. Thus, it is of interest to determine how interindividual differences in biomarker gene expression arise. Prior reports showed that the thermosensory neurons and insulin signaling systems controlled the magnitude of the heat shock response, including absolute expression of hsp-16.2. Here, we tested whether these regulatory signals might also influence variation in hsp-16.2 reporter expression. Genetic experiments showed that the action of AFD thermosensory neurons increases interindividual variation in biomarker expression. Further genetic experimentation showed the insulin signaling system acts to decrease interindividual variation in life-span biomarker expression; in other words, insulin signaling canalizes expression of the hsp-16.2-driven life-span biomarker. Our results show that specific signaling systems regulate not only expression level, but also the amount of interindividual expression variation for a life-span biomarker gene. They raise the possibility that manipulation of these systems might offer means to reduce heterogeneity in the aging process. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. The Development of Attentional Networks: Cross-Sectional Findings from a Life Span Sample

    Science.gov (United States)

    Waszak, Florian; Li, Shu-Chen; Hommel, Bernhard

    2010-01-01

    Using a population-based sample of 263 individuals ranging from 6 to 89 years of age, we investigated the gains and losses in the abilities to (a) use exogenous cues to shift attention covertly and (b) ignore conflicting information across the life span. The participants' ability to shift visual attention was tested by a typical Posner-type…

  18. Psychopathology in Williams Syndrome: The Effect of Individual Differences across the Life Span

    Science.gov (United States)

    Dodd, Helen F.; Porter, Melanie A.

    2009-01-01

    This research aimed to comprehensively explore psychopathology in Williams syndrome (WS) across the life span and evaluate the relationship between psychopathology and age category (child or adult), gender, and cognitive ability. The parents of 50 participants with WS, ages 6-50 years, were interviewed using the Schedule for Affective Disorders…

  19. ETS-4 Is a Transcriptional Regulator of Life Span in Caenorhabditis elegans

    Science.gov (United States)

    Thyagarajan, Bargavi; Blaszczak, Adam G.; Chandler, Katherine J.; Watts, Jennifer L.; Johnson, W. Evan; Graves, Barbara J.

    2010-01-01

    Aging is a complex phenotype responsive to a plethora of environmental inputs; yet only a limited number of transcriptional regulators are known to influence life span. How the downstream expression programs mediated by these factors (or others) are coordinated into common or distinct set of aging effectors is an addressable question in model organisms, such as C. elegans. Here, we establish the transcription factor ETS-4, an ortholog of vertebrate SPDEF, as a longevity determinant. Adult worms with ets-4 mutations had a significant extension of mean life span. Restoring ETS-4 activity in the intestine, but not neurons, of ets-4 mutant worms rescued life span to wild-type levels. Using RNAi, we demonstrated that ets-4 is required post-developmentally to regulate adult life span; thus uncoupling the role of ETS-4 in aging from potential functions in worm intestinal development. Seventy ETS-4-regulated genes, identified by gene expression profiling of two distinct ets-4 alleles and analyzed by bioinformatics, were enriched for known longevity effectors that function in lipid transport, lipid metabolism, and innate immunity. Putative target genes were enriched for ones that change expression during normal aging, the majority of which are controlled by the GATA factors. Also, some ETS-4-regulated genes function downstream of the FOXO factor, DAF-16 and the insulin/IGF-1 signaling pathway. However, epistasis and phenotypic analyses indicate that ets-4 functioned in parallel to the insulin/IGF-1 receptor, daf-2 and akt-1/2 kinases. Furthermore, ets-4 required daf-16 to modulate aging, suggesting overlap in function at the level of common targets that affect life span. In conclusion, ETS-4 is a new transcriptional regulator of aging, which shares transcriptional targets with GATA and FOXO factors, suggesting that overlapping pathways direct common sets of lifespan-related genes. PMID:20862312

  20. ETS-4 is a transcriptional regulator of life span in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Bargavi Thyagarajan

    2010-09-01

    Full Text Available Aging is a complex phenotype responsive to a plethora of environmental inputs; yet only a limited number of transcriptional regulators are known to influence life span. How the downstream expression programs mediated by these factors (or others are coordinated into common or distinct set of aging effectors is an addressable question in model organisms, such as C. elegans. Here, we establish the transcription factor ETS-4, an ortholog of vertebrate SPDEF, as a longevity determinant. Adult worms with ets-4 mutations had a significant extension of mean life span. Restoring ETS-4 activity in the intestine, but not neurons, of ets-4 mutant worms rescued life span to wild-type levels. Using RNAi, we demonstrated that ets-4 is required post-developmentally to regulate adult life span; thus uncoupling the role of ETS-4 in aging from potential functions in worm intestinal development. Seventy ETS-4-regulated genes, identified by gene expression profiling of two distinct ets-4 alleles and analyzed by bioinformatics, were enriched for known longevity effectors that function in lipid transport, lipid metabolism, and innate immunity. Putative target genes were enriched for ones that change expression during normal aging, the majority of which are controlled by the GATA factors. Also, some ETS-4-regulated genes function downstream of the FOXO factor, DAF-16 and the insulin/IGF-1 signaling pathway. However, epistasis and phenotypic analyses indicate that ets-4 functioned in parallel to the insulin/IGF-1 receptor, daf-2 and akt-1/2 kinases. Furthermore, ets-4 required daf-16 to modulate aging, suggesting overlap in function at the level of common targets that affect life span. In conclusion, ETS-4 is a new transcriptional regulator of aging, which shares transcriptional targets with GATA and FOXO factors, suggesting that overlapping pathways direct common sets of lifespan-related genes.

  1. ETS-4 is a transcriptional regulator of life span in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Bargavi Thyagarajan

    2010-09-01

    Full Text Available Aging is a complex phenotype responsive to a plethora of environmental inputs; yet only a limited number of transcriptional regulators are known to influence life span. How the downstream expression programs mediated by these factors (or others are coordinated into common or distinct set of aging effectors is an addressable question in model organisms, such as C. elegans. Here, we establish the transcription factor ETS-4, an ortholog of vertebrate SPDEF, as a longevity determinant. Adult worms with ets-4 mutations had a significant extension of mean life span. Restoring ETS-4 activity in the intestine, but not neurons, of ets-4 mutant worms rescued life span to wild-type levels. Using RNAi, we demonstrated that ets-4 is required post-developmentally to regulate adult life span; thus uncoupling the role of ETS-4 in aging from potential functions in worm intestinal development. Seventy ETS-4-regulated genes, identified by gene expression profiling of two distinct ets-4 alleles and analyzed by bioinformatics, were enriched for known longevity effectors that function in lipid transport, lipid metabolism, and innate immunity. Putative target genes were enriched for ones that change expression during normal aging, the majority of which are controlled by the GATA factors. Also, some ETS-4-regulated genes function downstream of the FOXO factor, DAF-16 and the insulin/IGF-1 signaling pathway. However, epistasis and phenotypic analyses indicate that ets-4 functioned in parallel to the insulin/IGF-1 receptor, daf-2 and akt-1/2 kinases. Furthermore, ets-4 required daf-16 to modulate aging, suggesting overlap in function at the level of common targets that affect life span. In conclusion, ETS-4 is a new transcriptional regulator of aging, which shares transcriptional targets with GATA and FOXO factors, suggesting that overlapping pathways direct common sets of lifespan-related genes.

  2. rBmαTX14 Increases the Life Span and Promotes the Locomotion of Caenorhabditis Elegans

    Science.gov (United States)

    Xu, Jie; Wan, Lu; Teng, Kaixuan; Xiang, Jin; Zhang, Rui; Huang, Zebo; Liu, Yongmei; Li, Wenhua; Liu, Xin

    2016-01-01

    The scorpion has been extensively used in various pharmacological profiles or as food supplies. The exploration of scorpion venom has been reported due to the presence of recombinant peptides. rBmαTX14 is an α-neurotoxin extracted from the venom gland of the East Asian scorpion Buthus martensii Karsch and can affect ion channel conductance. Here, we investigated the functions of rBmαTX14 using the Caenorhabditis elegans model. Using western blot analysis, rBmαTX14 was shown to be expressed both in the cytoplasm and inclusion bodies in the E.coli Rosetta (DE3) strain. Circular dichroism spectroscopy analysis demonstrated that purified rBmαTX14 retained its biological structures. Next, feeding nematodes with E.coli Rosetta (DE3) expressing rBmαTX14 caused extension of the life span and promoted the locomotion of the nematodes. In addition, we identified several genes that play various roles in the life span and locomotion of C. elegans through microarray analysis and quantitative real-time PCR. Furthermore, if the amino acid site H15 of rBmαTX14 was mutated, rBmαTX14 no longer promoted the C. elegans life span. In conclusion, the results not only demonstrated the functions and mechanism of rBmαTX14 in C. elegans, but also provided the new sight in the utility of recombinant peptides from scorpion venom. PMID:27611314

  3. D-chiro-inositol and pinitol extend the life span of Drosophila melanogaster.

    Science.gov (United States)

    Hada, Binika; Yoo, Mi-Ra; Seong, Ki Moon; Jin, Young-Woo; Myeong, Hyeon-Koon; Min, Kyung-Jin

    2013-03-01

    D-chiro-inositol, a member of the inositol family, and pinitol, a 3-methoxy analogue of D-chiro-inositol, have been proposed to have antidiabetic, antiinflammatory, anticancer and stamina enhancing effects. We found that supplementing the diet of Drosophila with D-chiro-inositol and pinitol extended adult longevity in both male and female flies. Life span extension was accompanied by protection against oxidative and starvation stresses, improvement in health span, and no reduction in fecundity. Pinitol increased the fly life span, both in dietary restriction and in ad libitum conditions, suggesting that pinitol increased life span in a manner that was independent of the dietary restriction pathway. Nuclear localization of dFOXO increased in D-chiro-inositol and pinitol-fed flies when compared with controls. Pinitol treatment significantly activated JNK and S6K, but not AKT, indicating that the activation of dFOXO by pinitol is acquired by the activation of S6K and JNK signaling. Hence, our study indicated that D-chiro-inositol and pinitol could be novel food-derived antiaging compounds.

  4. C. elegans VANG-1 modulates life span via insulin/IGF-1-like signaling.

    Directory of Open Access Journals (Sweden)

    Sebastian J Honnen

    Full Text Available The planar cell polarity (PCP pathway is highly conserved from Drosophila to humans and a PCP-like pathway has recently been described in the nematode Caenorhabditis elegans. The developmental function of this pathway is to coordinate the orientation of cells or structures within the plane of an epithelium or to organize cell-cell intercalation required for correct morphogenesis. Here, we describe a novel role of VANG-1, the only C. elegans ortholog of the conserved PCP component Strabismus/Van Gogh. We show that two alleles of vang-1 and depletion of the protein by RNAi cause an increase of mean life span up to 40%. Consistent with the longevity phenotype vang-1 animals also show enhanced resistance to thermal- and oxidative stress and decreased lipofuscin accumulation. In addition, vang-1 mutants show defects like reduced brood size, decreased ovulation rate and prolonged reproductive span, which are also related to gerontogenes. The germline, but not the intestine or neurons, seems to be the primary site of vang-1 function. Life span extension in vang-1 mutants depends on the insulin/IGF-1-like receptor DAF-2 and DAF-16/FoxO transcription factor. RNAi against the phase II detoxification transcription factor SKN-1/Nrf2 also reduced vang-1 life span that might be explained by gradual inhibition of insulin/IGF-1-like signaling in vang-1. This is the first time that a key player of the PCP pathway is shown to be involved in the insulin/IGF-1-like signaling dependent modulation of life span in C. elegans.

  5. 20S proteasome activation promotes life span extension and resistance to proteotoxicity in Caenorhabditis elegans.

    Science.gov (United States)

    Chondrogianni, Niki; Georgila, Konstantina; Kourtis, Nikos; Tavernarakis, Nektarios; Gonos, Efstathios S

    2015-02-01

    Protein homeostasis (proteostasis) is one of the nodal points that need to be preserved to retain physiologic cellular/organismal balance. The ubiquitin-proteasome system (UPS) is responsible for the removal of both normal and damaged proteins, with the proteasome being the downstream effector. The proteasome is the major cellular protease with progressive impairment of function during aging and senescence. Despite the documented age-retarding properties of proteasome activation in various cellular models, simultaneous enhancement of the 20S core proteasome content, assembly, and function have never been reported in any multicellular organism. Consequently, the possible effects of the core proteasome modulation on organismal life span are elusive. In this study, we have achieved activation of the 20S proteasome at organismal level. We demonstrate enhancement of proteasome levels, assembly, and activity in the nematode Caenorhabditis elegans, resulting in life span extension and increased resistance to stress. We also provide evidence that the observed life span extension is dependent on the transcriptional activity of Dauer formation abnormal/Forkhead box class O (DAF-16/FOXO), skinhead-1 (SKN-1), and heat shock factor-1 (HSF-1) factors through regulation of downstream longevity genes. We further show that the reported beneficial effects are not ubiquitous but they are dependent on the genetic context. Finally, we provide evidence that proteasome core activation might be a potential strategy to minimize protein homeostasis deficiencies underlying aggregation-related diseases, such as Alzheimer's disease (AD) or Huntington's disease (HD). In summary, this is the first report demonstrating that 20S core proteasome up-regulation in terms of both content and activity is feasible in a multicellular eukaryotic organism and that in turn this modulation promotes extension of organismal health span and life span.

  6. Non-linear impact of glutathione depletion on C. elegans life span and stress resistance

    Directory of Open Access Journals (Sweden)

    Nadine Urban

    2017-04-01

    Full Text Available The redox environment in cells and organisms is set by low-molecular mass and protein-bound thiols, with glutathione (GSH representing a major intracellular redox buffer. Subtle thiol oxidation elicits signal transduction processes and adaptive responses to cope with stressors, whereas highly oxidizing conditions may provoke cell death. We here tested how thiol depletion affects life span, stress resistance and stress signaling in the model organism Caenorhabditis elegans. Diethyl maleate (DEM, an α,β-unsaturated carbonyl compound that conjugates to GSH and other thiols, decreased C. elegans life span at a concentration of 1 mM. In contrast, low and moderate doses of DEM (10–100 µM increased mean and maximum life span and improved resistance against oxidative stress. DEM-induced life span extension was not detectable in worms deficient in either the FoxO orthologue, DAF-16, or the Nrf2 orthologue, SKN-1, pointing to a collaborative role of the two transcription factors in life span extension induced by thiol depletion. Cytoprotective target genes of DAF-16 and SKN-1 were upregulated after at least 3 days of exposure to 100 µM DEM, but not 1 mM DEM, whereas only 1 mM DEM caused upregulation of egl-1, a gene controlled by a p53-orthologue, CEP-1. In order to test whether depletion of GSH may elicit effects similar to DEM, we suppressed GSH biosynthesis in worms by attenuating γ-glutamylcysteine synthetase (gcs-1 expression through RNAi. The decline in GSH levels elicited by gcs-1 knockdown starting at young adult stage did not impair viability, but increased both stress resistance and life expectancy of the worms. In contrast, gcs-1 knockdown commencing right after hatching impaired nematode stress resistance and rendered young adult worms prone to vulval ruptures during egg-laying. Thus, modest decrease in GSH levels in young adult worms may promote stress resistance and life span, whereas depletion of GSH is detrimental to freshly

  7. Effect of habitat preference on frond life span in three Cyathea tree ferns

    Science.gov (United States)

    Chiu, Tzu Yun; Wang, Hsiang Hua; Lun Kuo, Yao; Kume, Tomonori

    2013-04-01

    It has been reported that plants living in various geographical areas had different physiological forms, as factors of microenvironment have strong impacts on physiological characters. However, the physiological characters of fronds have been scarcely reported in ferns. In this study, we investigated physiological differences in response to the habitat preference in the three tree ferns in northeast Taiwan, Cyathea lepifera, C. spinulosa, and C. podophylla, prefer to open site, edge of forest, and interior forest, respectively. The canopy openness above the individuals of C. lepifera, C. spinulosa and C. podophylla were 29.2 ± 14.10 , 7.0 ± 3.07 and 5.0 ± 2.24 %, respectively. Among three species, C. podophylla had the longest frond life span (13.0 ± 4.12 months) than the two others (C. lepifera (6.8 ± 1.29 months) and C. spinulosa (7.3 ±1.35 months). Our result supported the general patterns that shade intolerant species have a shorter leaf life span than shade tolerant species. The maximum net CO2 assimilation of C. lepifera, C. spinulosa and C. podophylla were 11.46 ± 1.34, 8.27 ± 0.69, and 6.34 ± 0.54 μmol CO2 m-2 s-1, respectively. As well, C. lepifera had the highest photosynthetic light saturation point (LSP), while C. podophylla had the lowest LSP among these three tree ferns. These suggested that C. lepifera could be more efficient for capturing and utilizing light resources under the larger canopy openness condition than the other two species. We also found that frond C : N ratio were positively correlated with frond life span among species. C. podophylla, with the longest frond life span, had the highest frond C : N ratio (22.17 ± 1.95), which was followed by C. spinulosa (18.58 ± 1.37) and C. lepifera (18.68 ± 2.63) with shorter frond life span. The results were consistent to the theory that the fronds and leaves of shade intolerant species have high photosynthetic abilities with low C : N ratio. Key words: Canopy openness, frond life span

  8. From menarche to menopause: the fertile life span of celiac women.

    Science.gov (United States)

    Santonicola, Antonella; Iovino, Paola; Cappello, Carmelina; Capone, Pietro; Andreozzi, Paolo; Ciacci, Carolina

    2011-10-01

    We evaluated menopause-associated disorders and fertile life span in women with celiac disease (CD) under untreated conditions and after long-term treatment with a gluten-free diet. The participants were 33 women with CD after menopause (untreated CD group), 25 celiac women consuming a gluten-free diet at least 10 years before menopause (treated CD group), and 45 healthy volunteers (control group). The Menopause Rating Scale questionnaire was used to gather information on menopause-associated disorders. The International Physical Activity Questionnaire was used to acquire information on physical activity. Untreated celiac women had a shorter duration of fertile life span than did the control women because of an older age of menarche and a younger age of menopause (P menopause causes a shorter fertile period in untreated celiac women compared with control women. A gluten-free diet that started at least 10 years before menopause prolongs the fertile life span of celiac women. The perception of intensity of hot flushes and irritability is more severe in untreated celiac women than in controls. Low physical exercise and/or poorer quality of life frequently reported by untreated celiac women might be the cause of reduced discomfort tolerance, thus increasing the subjective perception of menopausal symptoms.

  9. Gender differences in metformin effect on aging, life span and spontaneous tumorigenesis in 129/Sv mice

    Science.gov (United States)

    Anisimov, Vladimir N.; Piskunova, Tatiana S.; Popovich, Irina G.; Zabezhinski, Mark A.; Tyndyk, Margarita L.; Egormin, Peter A.; Yurova, Maria N.; Rosenfeld, Svetlana V.; Semenchenko, Anna V.; Kovalenko, Irina G.; Poroshina, Tatiana E.; Berstein, Lev M.

    2010-01-01

    Studies in mammals have led to the suggestion that hyperglycemia and hyperinsulinemia are important factors both in aging and in the development of cancer. It is possible that the life-prolonging effects of calorie restriction are due to decreasing IGF-1 levels. A search of pharmacological modulators of insulin/IGF-1 signaling pathway (which mimetic effects of life span extending mutations or calorie restriction) could be a perspective direction in regulation of longevity. Antidiabetic biguanides are most promising among them. The chronic treatment of inbred 129/Sv mice with metformin (100 mg/kg in drinking water) slightly modified the food consumption but failed to influence the dynamics of body weight, decreased by 13.4% the mean life span of male mice and slightly increased the mean life span of female mice (by 4.4%). The treatment with metformin failed influence spontaneous tumor incidence in male 129/Sv mice, decreased by 3.5 times the incidence of malignant neoplasms in female mice while somewhat stimulated formation of benign vascular tumors in the latter. PMID:21164223

  10. Resting-State Network Topology Differentiates Task Signals across the Adult Life Span.

    Science.gov (United States)

    Chan, Micaela Y; Alhazmi, Fahd H; Park, Denise C; Savalia, Neil K; Wig, Gagan S

    2017-03-08

    individuals, we hypothesized that individual differences in network connectivity would relate to differences in brain activity. Using functional MRI in a group of individuals sampled across the adult life span (20-89 years), we measured correlations at rest and related the functional connectivity patterns to measurements of functional activity during two independent tasks. Brain activity varied in relation to connectivity patterns revealed by large-scale network analysis. This relationship tracked the differences in connectivity patterns accompanied by older age, providing important evidence for a link between the topology of areal connectivity measured at rest and the functional recruitment of these areas during task performance.

  11. Resveratrol in mammals: effects on aging biomarkers, age-related diseases, and life span.

    Science.gov (United States)

    Marchal, Julia; Pifferi, Fabien; Aujard, Fabienne

    2013-07-01

    Through its antioxidant, anticarcinogenic, and anti-inflammatory properties, resveratrol has become a candidate for drug development in the context of aging studies. Scientific evidence has highlighted its potential as a therapeutic agent for cardiovascular diseases and some cancers but also as an antiaging molecule. Resveratrol is thought to mimic the beneficial effects of chronic and moderate calorie restriction. Nevertheless, no study has demonstrated the prolongation of life span in healthy nonobese mammal models. This review summarizes recent findings on the effects of resveratrol on aging and life span in mammals. In our opinion, more studies should be performed to assess the effects of a chronic dietary intake of resveratrol in long-lived species close to humans, such as nonhuman primates. This will certainly generate more evidence about the ability of resveratrol to achieve the physiological benefits that have been observed in small mammal laboratory models and feature the eventual unwanted secondary effects that may occur under high levels of resveratrol.

  12. NAD⁺ repletion improves mitochondrial and stem cell function and enhances life span in mice.

    Science.gov (United States)

    Zhang, Hongbo; Ryu, Dongryeol; Wu, Yibo; Gariani, Karim; Wang, Xu; Luan, Peiling; D'Amico, Davide; Ropelle, Eduardo R; Lutolf, Matthias P; Aebersold, Ruedi; Schoonjans, Kristina; Menzies, Keir J; Auwerx, Johan

    2016-06-17

    Adult stem cells (SCs) are essential for tissue maintenance and regeneration yet are susceptible to senescence during aging. We demonstrate the importance of the amount of the oxidized form of cellular nicotinamide adenine dinucleotide (NAD(+)) and its effect on mitochondrial activity as a pivotal switch to modulate muscle SC (MuSC) senescence. Treatment with the NAD(+) precursor nicotinamide riboside (NR) induced the mitochondrial unfolded protein response and synthesis of prohibitin proteins, and this rejuvenated MuSCs in aged mice. NR also prevented MuSC senescence in the mdx (C57BL/10ScSn-Dmd(mdx)/J) mouse model of muscular dystrophy. We furthermore demonstrate that NR delays senescence of neural SCs and melanocyte SCs and increases mouse life span. Strategies that conserve cellular NAD(+) may reprogram dysfunctional SCs and improve life span in mammals.

  13. Basic traits predict the prevalence of personality disorder across the life span: the example of psychopathy.

    Science.gov (United States)

    Vachon, David D; Lynam, Donald R; Widiger, Thomas A; Miller, Joshua D; McCrae, Robert R; Costa, Paul T

    2013-05-01

    Personality disorders (PDs) may be better understood in terms of dimensions of general personality functioning rather than as discrete categorical conditions. Personality-trait descriptions of PDs are robust across methods and settings, and PD assessments based on trait measures show good construct validity. The study reported here extends research showing that basic traits (e.g., impulsiveness, warmth, straightforwardness, modesty, and deliberation) can re-create the epidemiological characteristics associated with PDs. Specifically, we used normative changes in absolute trait levels to simulate age-related differences in the prevalence of psychopathy in a forensic setting. Results demonstrated that trait information predicts the rate of decline for psychopathy over the life span; discriminates the decline of psychopathy from that of a similar disorder, antisocial PD; and accurately predicts the differential decline of subfactors of psychopathy. These findings suggest that basic traits provide a parsimonious account of PD prevalence across the life span.

  14. The decline of verbal and visuospatial working memory across the adult life span

    OpenAIRE

    Cansino, Selene; Hernández-Ramos, Evelia; Estrada-Manilla, Cinthya; Torres-Trejo, Frine; Martínez-Galindo, Joyce Graciela; Ayala-Hernández, Mariana; Gómez-Fernández, Tania; Osorio, David; Cedillo-Tinoco, Melisa; Garcés-Flores, Lissete; Beltrán-Palacios, Karla; García-Lázaro, Haydée Guadalupe; García-Gutiérrez, Fabiola; Cadena-Arenas, Yadira; Fernández-Apan, Luisa

    2013-01-01

    It has been well established that working memory abilities decrease with advancing age; however, the specific time point in the adult life span at which this deficit begins and the rate at which it advances are still controversial. There is no agreement on whether working memory declines equally for visuospatial and verbal information, and the literature disagrees on how task difficulty may influence this decay. We addressed these questions in a lifespan sample of 1,500 participants between 2...

  15. Implicit motor sequence learning and working memory performance changes across the adult life span

    OpenAIRE

    Sarah Nadine Meissner; Ariane eKeitel; Martin eSüdmeyer; Bettina ePollok

    2016-01-01

    Although implicit motor sequence learning is rather well understood in young adults, effects of aging on this kind of learning are controversial. There is first evidence that working memory (WM) might play a role in implicit motor sequence learning in young adults as well as in adults above the age of 65. However the knowledge about the development of these processes across the adult life span is rather limited. As the average age of our population continues to rise, a better understanding of...

  16. Implicit Motor Sequence Learning and Working Memory Performance Changes Across the Adult Life Span

    OpenAIRE

    Meissner, Sarah Nadine; Keitel, Ariane; Südmeyer, Martin; Pollok, Bettina

    2016-01-01

    Although implicit motor sequence learning is rather well understood in young adults, effects of aging on this kind of learning are controversial. There is first evidence that working memory (WM) might play a role in implicit motor sequence learning in young adults as well as in adults above the age of 65. However, the knowledge about the development of these processes across the adult life span is rather limited. As the average age of our population continues to rise, a better understanding o...

  17. Childhood self-control and unemployment throughout the life span: evidence from two British cohort studies.

    Science.gov (United States)

    Daly, Michael; Delaney, Liam; Egan, Mark; Baumeister, Roy F

    2015-06-01

    The capacity for self-control may underlie successful labor-force entry and job retention, particularly in times of economic uncertainty. Analyzing unemployment data from two nationally representative British cohorts (N = 16,780), we found that low self-control in childhood was associated with the emergence and persistence of unemployment across four decades. On average, a 1-SD increase in self-control was associated with a reduction in the probability of unemployment of 1.4 percentage points after adjustment for intelligence, social class, and gender. From labor-market entry to middle age, individuals with low self-control experienced 1.6 times as many months of unemployment as those with high self-control. Analysis of monthly unemployment data before and during the 1980s recession showed that individuals with low self-control experienced the greatest increases in unemployment during the recession. Our results underscore the critical role of self-control in shaping life-span trajectories of occupational success and in affecting how macroeconomic conditions affect unemployment levels in the population. © The Author(s) 2015.

  18. Life-Span Differences in the Uses and Gratifications of Tablets: Implications for Older Adults.

    Science.gov (United States)

    Magsamen-Conrad, Kate; Dowd, John; Abuljadail, Mohammad; Alsulaiman, Saud; Shareefi, Adnan

    2015-11-01

    This study extends Uses and Gratifications theory by examining the uses and gratifications of a new technological device, the tablet computer, and investigating the differential uses and gratifications of tablet computers across the life-span. First, we utilized a six-week tablet training intervention to adapt and extend existing measures to the tablet as a technological device. Next, we used paper-based and online surveys (N=847), we confirmed four main uses of tablets: 1) Information Seeking, 2) Relationship Maintenance, 3) Style, 4) Amusement and Killing time, and added one additional use category 5) Organization. We discovered differences among the five main uses of tablets across the life-span, with older adults using tablets the least overall. Builders, Boomers, GenX and GenY all reported the highest means for information seeking. Finally, we used a structural equation model to examine how uses and gratifications predicts hours of tablet use. The study provides limitations and suggestions for future research and marketers. In particular, this study offers insight to the relevancy of theory as it applies to particular information and communication technologies and consideration of how different periods in the life-span affect tablet motivations.

  19. Trade-off between cellular immunity and life span in mealworm beetles Tenebrio molitor

    Institute of Scientific and Technical Information of China (English)

    Indrikis KRAMS; Jan(i)na DAUK(S)TE; Inese KIVLENIECE; Ants KAASIK; Tatjana KRAMA; Todd M.FREEBERG; Markus J.RANTALA

    2013-01-01

    Encapsulation is a nonspecific,cellular response through which insects defend themselves against multicellular pathogens.During this immune reaction,haemocytes recognize an object as foreign and cause other haemocytes to aggregate and form a capsule around the object,often consisting of melanized cells.The process of melanisation is accompanied by the formation of potentially toxic reactive oxygen species,which can kill not only pathogens but also host cells.In this study we tested whether the encapsulation response is costly in mealworm beetles Tenebrio molitor.We found a negative relationship between the duration of implantation via a nylon monofilament and remaining life span.We also found a negative relationship between the strength of immune response and remaining life span,suggesting that cellular immunity is costly in T.molitor,and that there is a trade-off between immune response and remaining life span.However,this relationship disappeared at 31-32 hours of implantation at 25 ± 2℃.As the disappearance of a relationship between duration of implantation and lifespan coincided with the highest values of encapsulation response,we concluded that the beetles stopped investment in the production of melanotic cells,as the implant,a synthetic parasite,was fully isolated from the host's tissues.

  20. Trade-off between cellular immunity and life span in mealworm beetles Tenebrio molitor

    Directory of Open Access Journals (Sweden)

    Indrikis KRAMS, Janīna DAUKŠTE, Inese KIVLENIECE, Ants KAASIK, Tatjana KRAMA, Todd M. REEBERG, Markus J. RANTALA

    2013-06-01

    Full Text Available Encapsulation is a nonspecific, cellular response through which insects defend themselves against multicellular pathogens. During this immune reaction, haemocytes recognize an object as foreign and cause other haemocytes to aggregate and form a capsule around the object, often consisting of melanized cells. The process of melanisation is accompanied by the formation of potentially toxic reactive oxygen species, which can kill not only pathogens but also host cells. In this study we tested whether the encapsulation response is costly in mealworm beetles Tenebrio molitor. We found a negative relationship between the duration of implantation via a nylon monofilament and remaining life span. We also found a negative relationship between the strength of immune response and remaining life span, suggesting that cellular immunity is costly in T. molitor, and that there is a trade-off between immune response and remaining life span. However, this relationship disappeared at 31-32 hours of implantation at 25 ± 2℃. As the disappearance of a relationship between duration of implantation and lifespan coincided with the highest values of encapsulation response, we concluded that the beetles stopped investment in the production of melanotic cells, as the implant, a synthetic parasite, was fully isolated from the host’s tissues [Current Zoology 59 (3: 340–346, 2013].

  1. Life span and reproductive cost explain interspecific variation in the optimal onset of reproduction.

    Science.gov (United States)

    Mourocq, Emeline; Bize, Pierre; Bouwhuis, Sandra; Bradley, Russell; Charmantier, Anne; de la Cruz, Carlos; Drobniak, Szymon M; Espie, Richard H M; Herényi, Márton; Hötker, Hermann; Krüger, Oliver; Marzluff, John; Møller, Anders P; Nakagawa, Shinichi; Phillips, Richard A; Radford, Andrew N; Roulin, Alexandre; Török, János; Valencia, Juliana; van de Pol, Martijn; Warkentin, Ian G; Winney, Isabel S; Wood, Andrew G; Griesser, Michael

    2016-02-01

    Fitness can be profoundly influenced by the age at first reproduction (AFR), but to date the AFR-fitness relationship only has been investigated intraspecifically. Here, we investigated the relationship between AFR and average lifetime reproductive success (LRS) across 34 bird species. We assessed differences in the deviation of the Optimal AFR (i.e., the species-specific AFR associated with the highest LRS) from the age at sexual maturity, considering potential effects of life history as well as social and ecological factors. Most individuals adopted the species-specific Optimal AFR and both the mean and Optimal AFR of species correlated positively with life span. Interspecific deviations of the Optimal AFR were associated with indices reflecting a change in LRS or survival as a function of AFR: a delayed AFR was beneficial in species where early AFR was associated with a decrease in subsequent survival or reproductive output. Overall, our results suggest that a delayed onset of reproduction beyond maturity is an optimal strategy explained by a long life span and costs of early reproduction. By providing the first empirical confirmations of key predictions of life-history theory across species, this study contributes to a better understanding of life-history evolution.

  2. Life span of C57 mice as influenced by radiation dose, dose rate, and age at exposure

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, J.F.; Thomas, R.G.; Tietjen, G.L.

    1982-10-01

    This study was designed to measure the life shortening of C57BL/6J male mice as a result of exposure to five external doses from /sup 60/Co gamma radiation delivered at six different dose rates. Total doses ranged from 20 to 1620 rad at exposure rates ranging from 0.7 to 36,000 R/day. The ages of the mice at exposure were newborn, 2, 6, or 15 months. Two replications were completed. Although death was the primary endpoint, we did perform gross necropsies. The life span findings are variable, but we found no consistent shortening compared to control life spans. Therefore, we cannot logically extrapolate life shortening to lower doses, from the data we have obtained. In general, the younger the animals were at the beginning of exposure, the longer their life spans were compared to those of controls. This relationship weakened at the higher doses and dose rates, as mice in these categories tended not to have significantly different life spans from controls. Using life span as a criterion, we find this study suggests that some threshold dosage may exist beyond which effects of external irradiation may be manifested. Up to this threshold, there is no shortening effect on life span compared to that of control mice. Our results are in general agreement with the results of other researchers investigating human and other animal life span effects on irradiation.

  3. Life Satisfaction, Self-Esteem, and Subjective Age in Women across the Life Span

    Science.gov (United States)

    Borzumato-Gainey, Christine; Kennedy, Alison; McCabe, Beth; Degges-White, Suzanne

    2009-01-01

    A study of 320 women, ages 21 to 69, explored the relations among relationship status, subjective age, self-esteem, and life satisfaction. Women in married or partnered relationships had higher levels of life satisfaction than did single women. Women in their 30s and 40s had significantly lower levels of life satisfaction than did other age…

  4. Dead or alive: deformed wing virus and Varroa destructor reduce the life span of winter honeybees.

    Science.gov (United States)

    Dainat, Benjamin; Evans, Jay D; Chen, Yan Ping; Gauthier, Laurent; Neumann, Peter

    2012-02-01

    Elevated winter losses of managed honeybee colonies are a major concern, but the underlying mechanisms remain controversial. Among the suspects are the parasitic mite Varroa destructor, the microsporidian Nosema ceranae, and associated viruses. Here we hypothesize that pathogens reduce the life expectancy of winter bees, thereby constituting a proximate mechanism for colony losses. A monitoring of colonies was performed over 6 months in Switzerland from summer 2007 to winter 2007/2008. Individual dead workers were collected daily and quantitatively analyzed for deformed wing virus (DWV), acute bee paralysis virus (ABPV), N. ceranae, and expression levels of the vitellogenin gene as a biomarker for honeybee longevity. Workers from colonies that failed to survive winter had a reduced life span beginning in late fall, were more likely to be infected with DWV, and had higher DWV loads. Colony levels of infection with the parasitic mite Varroa destructor and individual infections with DWV were also associated with reduced honeybee life expectancy. In sharp contrast, the level of N. ceranae infection was not correlated with longevity. In addition, vitellogenin gene expression was significantly positively correlated with ABPV and N. ceranae loads. The findings strongly suggest that V. destructor and DWV (but neither N. ceranae nor ABPV) reduce the life span of winter bees, thereby constituting a parsimonious possible mechanism for honeybee colony losses.

  5. Causes of decreased life expectancy over the life span in bipolar disorder

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; McIntyre, Roger S

    2015-01-01

    BACKGROUND: Accelerated aging has been proposed as a mechanism explaining the increased prevalence of comorbid general medical illnesses in bipolar disorder. AIMS: To test the hypothesis that lost life years due to natural causes starts in early and mid-adulthood, supporting the hypothesis...... of accelerated aging. METHODS: Using individual data from nationwide registers of patient with a diagnosis of bipolar disorder we calculated remaining life expectancies before age 90 years for values of age 15, 25, 35…75 years among all individuals alive in year 2000. Further, we estimated the reduction in life......, remaining life expectancy before age 90 years was decreased 12.7 and 8.9 life years, respectively, for men and women with bipolar disorder. For 15-year old boys with bipolar disorder, natural causes accounted for 58% of all lost life years and for 15-year old girls, natural causes accounted for 67...

  6. Resilience, according to the paradigm of the development along the life (life-span)

    OpenAIRE

    Arlete Portella Fontes

    2010-01-01

    Resilience, in the approach of the development along the life, refers to the capacity of recovering and maintenance of the adaptive behavior when the person feels threatened by any distressing event (Staudinger, Marsiske and Baltes, 1995). Although the losses become more likely than the developed gains, the aged people can present considerable stability, self-esteem, competence, self-efficacy, subjective quality of life. The resilience is based on active protecting resources along the life: m...

  7. Structural health monitoring of long-span suspension bridges using wavelet packet analysis

    Institute of Scientific and Technical Information of China (English)

    Ding Youliang; Li Aiqun

    2007-01-01

    During the service life of civil engineering structures such as long-span bridges, local damage at key positions may continually accumulate, and may finally result in their sudden failure. One core issue of global vibration-based health monitoring methods is to seek some damage indices that are sensitive to structural damage. This paper proposes an online structural health monitoring method for long-span suspension bridges using wavelet packet transform (WPT). The WPTbased method is based on the energy variations of structural ambient vibration responses decomposed using wavelet packet analysis. The main feature of this method is that the proposed wavelet packet energy spectrum (WPES) has the ability to detect structural damage from ambient vibration tests of a long-span suspension bridge. As an example application, the WPES-based health monitoring system is used on the Runyang Suspension Bridge under daily environmental conditions. The analysis reveals that changes in environmental temperature have a long-term influence on the WPES, while the effect of traffic loadings on the measured WPES of the bridge presents instantaneous changes because of the nonstationary properties of the loadings. The condition indication indices VD reflect the influences of environmental temperature on the dynamic properties of the Runyang Suspension Bridge. The field tests demonstrate that the proposed WPES-based condition indication index VD is a good candidate index for health monitoring of long-span suspension bridges under ambient excitations.

  8. Structural health monitoring of long-span suspension bridges using wavelet packet analysis

    Science.gov (United States)

    Ding, Youliang; Li, Aiqun

    2007-09-01

    During the service life of civil engineering structures such as long-span bridges, local damage at key positions may continually accumulate, and may finally result in their sudden failure. One core issue of global vibration-based health monitoring methods is to seek some damage indices that are sensitive to structural damage. This paper proposes an online structural health monitoring method for long-span suspension bridges using wavelet packet transform (WPT). The WPT-based method is based on the energy variations of structural ambient vibration responses decomposed using wavelet packet analysis. The main feature of this method is that the proposed wavelet packet energy spectrum (WPES) has the ability to detect structural damage from ambient vibration tests of a long-span suspension bridge. As an example application, the WPES-based health monitoring system is used on the Runyang Suspension Bridge under daily environmental conditions. The analysis reveals that changes in environmental temperature have a long-term influence on the WPES, while the effect of traffic loadings on the measured WPES of the bridge presents instantaneous changes because of the nonstationary properties of the loadings. The condition indication indices V D reflect the influences of environmental temperature on the dynamic properties of the Runyang Suspension Bridge. The field tests demonstrate that the proposed WPES-based condition indication index V D is a good candidate index for health monitoring of long-span suspension bridges under ambient excitations.

  9. Partner preferences across the life span: online dating by older adults.

    Science.gov (United States)

    Alterovitz, Sheyna Sears-Roberts; Mendelsohn, Gerald A

    2009-06-01

    Stereotypes of older adults as withdrawn or asexual fail to recognize that romantic relationships in later life are increasingly common. The authors analyzed 600 Internet personal ads from 4 age groups: 20-34, 40-54, 60-74, and 75+ years. Predictions from evolutionary theory held true in later life, when reproduction is no longer a concern. Across the life span, men sought physical attractiveness and offered status-related information more than women; women were more selective than men and sought status more than men. With age, men desired women increasingly younger than themselves, whereas women desired older men until ages 75 and over, when they sought men younger than themselves.

  10. Life satisfaction, distress, and resiliency across the life span of women.

    Science.gov (United States)

    Beutel, Manfred E; Glaesmer, Heide; Decker, Oliver; Fischbeck, Sabine; Brähler, Elmar

    2009-01-01

    This study aimed to determine (1) the relationship between life satisfaction, mental disorders, and aging in the female community and (2) to identify the impact of vulnerability factors, personal (resilience, self-esteem), and social resources on life satisfaction and distress. A stratified random sample of the German female population (N = 2,540) was investigated using standardized questionnaires of life satisfaction (Questions on Life Satisfaction), depression, anxiety (Patient Health Questionnaire), resilience scale (RS-11), and self-esteem (Rosenberg Self-Esteem Scale). When participants were divided into six age groups (18-30, 31-40, 41-50, 51-60, 61-70, and >70 y), we found lower life satisfaction, satisfaction with partnership, and sexuality beyond the age of 50 years. Satisfaction with health was decreased already at early adulthood. Although the importance of partnership/sexuality was reduced around midlife, the importance of health increased. Depression was highest in the oldest group, whereas anxiety remained fairly stable across the cohorts. Life satisfaction was strongly associated with resilience, a good household income, the presence of a partnership, absence of anxiety and depression, lack of unemployment, positive self-esteem, religious affiliation, and-least-age. Personal and social resources and the absence of anxiety and depression are of crucial importance for the maintenance of life satisfaction in aging women.

  11. The life span-prolonging effect of sirtuin-1 is mediated by autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Maiuri, Maria Chiara; Markaki, Maria; Megalou, Evgenia; Pasparaki, Angela; Palikaras, Konstantinos; Criollo, Alfredo; Galluzzi, Lorenzo; Malik, Shoaib Ahmad; Vitale, Ilio; Michaud, Mickael; Madeo, Frank; Tavernarakis, Nektarios; Kroemer, Guido

    2010-01-01

    The life span of various model organisms can be extended by caloric restriction as well as by autophagy-inducing pharmacological agents. Life span-prolonging effects have also been observed in yeast cells, nematodes and flies upon the overexpression of the deacetylase Sirtuin-1. Intrigued by these observations and by the established link between caloric restriction and Sirtuin-1 activation, we decided to investigate the putative implication of Sirtuin-1 in the response of human cancer cells and Caenorhabditis elegans to multiple triggers of autophagy. Our data indicate that the activation of Sirtuin-1 (by the pharmacological agent resveratrol and/or genetic means) per se ignites autophagy, and that Sirtuin-1 is required for the autophagic response to nutrient deprivation, in both human and nematode cells, but not for autophagy triggered by downstream signals such as the inhibition of mTOR or p53. Since the life spanextending effects of Sirtuin-1 activators are lost in autophagy-deficient C. elegans, our results suggest that caloric restriction and resveratrol extend longevity, at least in experimental settings, by activating autophagy.

  12. From children to adults: motor performance across the life-span.

    Directory of Open Access Journals (Sweden)

    Jonas S R Leversen

    Full Text Available The life-span approach to development provides a theoretical framework to examine the general principles of life-long development. This study aims to investigate motor performance across the life span. It also aims to investigate if the correlations between motor tasks increase with aging. A cross-sectional design was used to describe the effects of aging on motor performance across age groups representing individuals from childhood to young adult to old age. Five different motor tasks were used to study changes in motor performance within 338 participants (7-79 yrs. Results showed that motor performance increases from childhood (7-9 to young adulthood (19-25 and decreases from young adulthood (19-25 to old age (66-80. These results are mirroring results from cognitive research. Correlation increased with increasing age between two fine motor tasks and two gross motor tasks. We suggest that the findings might be explained, in part, by the structural changes that have been reported to occur in the developing and aging brain and that the theory of Neural Darwinism can be used as a framework to explain why these changes occur.

  13. Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

    Science.gov (United States)

    Stampfer, Martha R; Garbe, James C

    2015-02-24

    Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.

  14. Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

    Energy Technology Data Exchange (ETDEWEB)

    Stampfer, Martha R.; Garbe, James C.

    2016-06-28

    Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.

  15. Two-carbon metabolites, polyphenols and vitamins influence yeast chronological life span in winemaking conditions

    Directory of Open Access Journals (Sweden)

    Orozco Helena

    2012-08-01

    Full Text Available Abstract Background Viability in a non dividing state is referred to as chronological life span (CLS. Most grape juice fermentation happens when Saccharomyces cerevisiae yeast cells have stopped dividing; therefore, CLS is an important factor toward winemaking success. Results We have studied both the physical and chemical determinants influencing yeast CLS. Low pH and heat shorten the maximum wine yeast life span, while hyperosmotic shock extends it. Ethanol plays an important negative role in aging under winemaking conditions, but additional metabolites produced by fermentative metabolism, such as acetaldehyde and acetate, have also a strong impact on longevity. Grape polyphenols quercetin and resveratrol have negative impacts on CLS under winemaking conditions, an unexpected behavior for these potential anti-oxidants. We observed that quercetin inhibits alcohol and aldehyde dehydrogenase activities, and that resveratrol performs a pro-oxidant role during grape juice fermentation. Vitamins nicotinic acid and nicotinamide are precursors of NAD+, and their addition reduces mean longevity during fermentation, suggesting a metabolic unbalance negative for CLS. Moreover, vitamin mix supplementation at the end of fermentation shortens CLS and enhances cell lysis, while amino acids increase life span. Conclusions Wine S. cerevisiae strains are able to sense changes in the environmental conditions and adapt their longevity to them. Yeast death is influenced by the conditions present at the end of wine fermentation, particularly by the concentration of two-carbon metabolites produced by the fermentative metabolism, such as ethanol, acetic acid and acetaldehyde, and also by the grape juice composition, particularly its vitamin content.

  16. Resveratrol Attenuates Oxidative Stress and Extends Life Span in the Annual Fish Nothobranchius guentheri.

    Science.gov (United States)

    Liu, Tingting; Qi, He; Ma, Long; Liu, Zhaojun; Fu, Huiling; Zhu, Wenzhen; Song, Taiyu; Yang, Bingwu; Li, Guorong

    2015-06-01

    Resveratrol is a natural polyphenol derived mainly from the skin of grapes and from red wine. Resveratrol prolongs life span in several invertebrates, but this function is not found in mice. Our recently published paper demonstrated that resveratrol prolonged longevity of the annual fish Nothobranchius guentheri, a promising vertebrate model for anti-aging research. However, the anti-aging process by resveratrol remains largely unexplored, and little is known about its effects on oxidative stress. In this study, by long-term supplementation of resveratrol from sexual maturity onward in the annual fish, we detected survivorship and oxidative stress at three different developmental stages in vivo. A total of 112 fish were fed with resveratrol in the concentration of 200 μg/gram food and 111 fish without resveratrol from 16 weeks of age until to the end of their lives. The mean and maximum life spans of the fish treated with resveratrol were extended by 17.34% and 17.66%, respectively, compared to the fish in control group. The markers of oxidative stress, such as the levels of reactive oxygen species (ROS), the activities of anti-oxidant enzymes, and the degree of oxidative damage, were detected at 6, 9, and 12 months, respectively. The results showed that levels of ROS and oxidative damage increased and activities of anti-oxidant enzymes appeared to decrease with age. Resveratrol treatment significantly attenuated the increase of ROS and oxidative damage and up-regulated the decrease of anti-oxidant enzyme activities induced by aging. Our results demonstrated that resveratrol decreased oxidative stress and extended life span in this short-lived fish.

  17. Gender, Race, and Age: The Content of Compound Stereotypes Across the Life Span.

    Science.gov (United States)

    Andreoletti, Carrie; Leszczynski, Jennifer P; Disch, William B

    2015-07-01

    While stereotypes about gender, race, and age (particularly old age) have been studied independently, few have examined the content of compound stereotypes that consider the intersection of gender, race, and age. Using a within-subjects design, we examined stereotypes as a function of target gender (male, female), race (Black, White), and age across the life span (adolescent, young adult, middle-aged, young-old, and old-old). Participants rated 20 target groups on 10 attributes representative of either an agentic (e.g., ambitious) or communal (e.g., considerate) orientation. Participants were presented only with categorical information (e.g., Black, 85-year-old, males), and ordering of categorical information and target groups was counterbalanced across participants. We hypothesized differential effects of target gender and race as a function of age. Multivariate analyses of variance on each attribute revealed significant main effects that supported traditional stereotype research, but significant interactions revealed a more complicated picture. Overall, results showed that while gender stereotypes about agency and communion generally hold up across the life span, they are more applicable to White than Black targets. Results also supported the notion that we hold unique stereotypes based on multiple social categories rather than simply perceiving one social category as more salient than another, which was best exemplified in the case of Black female targets that were less likely to be perceived in gender stereotypic ways across the life span. We suggest stereotype research needs to shift to accommodate for the complexity and diversity of real people.

  18. Sexual orientation across the life span: introduction to the special section.

    Science.gov (United States)

    Patterson, Charlotte J

    2008-01-01

    What impact does sexual orientation have on human development over the life span? As questions related to sexual orientation have become increasingly topics of public discussion and debate in recent years, psychological study of the issues has also burgeoned. What was once a new frontier for research has matured into a large, complex, and rapidly growing area of knowledge. Important research is being conducted on many issues, by diverse investigators, from a number of theoretical perspectives, in many parts of the world. The articles in this special section provide only a sampling of current research, but they begin to suggest the vitality and excitement of a field that is coming into its own.

  19. Life-span of classical solutions for one-dimensional hydromagnetic flow

    Institute of Scientific and Technical Information of China (English)

    LIU Fa-gui

    2007-01-01

    The paper concerns Cauchy problem for one-dimensional hydromagnetic dynamics with dissipative terms. When the dissipation coefficient is equal to zero it is shown that the smooth solutions develop shocks in the finite time if the initial amounts of entropy and magnetic field are smaller than those of sound waves; when it is larger than zero, and the initial amounts of entropy, this dissipation coefficient and the magnetic field in each period are smaller than those of sound waves, then the smooth solutions blow up in the finite time. Moreover, the life-span of the smooth solution is given.

  20. Life satisfaction, anxiety, depression and resilience across the life span of men.

    Science.gov (United States)

    Beutel, Manfred E; Glaesmer, Heide; Wiltink, Jörg; Marian, Hanna; Brähler, Elmar

    2010-03-01

    To determine (a) the relationship between life satisfaction, anxiety, depression and ageing in the male community and (b) to identify the impact of vulnerability factors, personal and social resources on life satisfaction and distress. A stratified random sample of the German male population (N = 2144) was investigated by standardized questionnaires of life satisfaction (FLZ(M)), depression, anxiety (PHQ), resilience (RS-11) and self-esteem (RSS). No age-related change was found regarding overall life satisfaction. Satisfaction with health decreased in midlife (51-60 years), while the importance of health increased. Importance of and satisfaction with partnership and sexuality were only reduced in the oldest group (70+). Anxiety was highest around midlife (51-60 years), accompanied by reduced resilience and self-esteem. No clear age-related change was found regarding depression. Life satisfaction was strongly associated with resilience, lack of unemployment, the presence of a partnership, positive self-esteem, a good household income, the absence of anxiety and depression and living in the Eastern states. Personal and social resources and the absence of anxiety and depression are of crucial importance for the maintenance of life satisfaction in ageing men. There is also evidence for a crisis around midlife manifested by health concerns, anxiety and reduced resilience.

  1. Resilience, according to the paradigm of the development along the life (life-span

    Directory of Open Access Journals (Sweden)

    Arlete Portella Fontes

    2010-10-01

    Full Text Available Resilience, in the approach of the development along the life, refers to the capacity of recovering and maintenance of the adaptive behavior when the person feels threatened by any distressing event (Staudinger, Marsiske and Baltes, 1995. Although the losses become more likely than the developed gains, the aged people can present considerable stability, self-esteem, competence, self-efficacy, subjective quality of life. The resilience is based on active protecting resources along the life: mechanisms of self-regulation, self-efficacy, emotional regulation, mechanisms of stress oping, selection strategies, optimization and compensation of the domains of human functioning. At the end of the article, interventions to increase the resilience of the aged are suggested.

  2. Studies on the life span, reproduction, tissue biochemistry and diesel oil toxicity in the estuarine cladocera Diaphanosoma celebensis

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhuKonkar, S.R.; Achuthankutty, C.T.

    , neonate production, tissue biochemistry and toxicity of diesel oil have been described in the paper. Variations were observed in the life span and rate of neonate production between individuals of the 1 st and 2 nd generations. Both were found...

  3. Career Adaptability: An Integrative Construct for Life-Span, Life-Space Theory.

    Science.gov (United States)

    Savickas, Mark L.

    1997-01-01

    Examines the origin and current status of lifespan, life-space theory and proposes one way in which to integrate its three segments. Discusses a functionalist strategy for theory construction and the outcomes and consequences of this strategy. Discusses future directions for theory development, such as career adaptability and planful attitudes.…

  4. Career Adaptability: An Integrative Construct for Life-Span, Life-Space Theory.

    Science.gov (United States)

    Savickas, Mark L.

    1997-01-01

    Examines the origin and current status of lifespan, life-space theory and proposes one way in which to integrate its three segments. Discusses a functionalist strategy for theory construction and the outcomes and consequences of this strategy. Discusses future directions for theory development, such as career adaptability and planful attitudes.…

  5. Relation of behaviour and macrophage function to life span in a murine model of premature immunosenescence.

    Science.gov (United States)

    Guayerbas, Noelia; Catalán, Marina; Víctor, Víctor M; Miquel, Jaime; De la Fuente, Mónica

    2002-08-21

    According to our previous work, mice of the same strain and age show striking inter-individual differences in behaviour when exposed to a T-maze test. Further, the animals exploring the maze slowly (slow mice) or staying at the starting point (freezing behaviour), which show high levels of emotionality/anxiety in other standard behavioural tests, have a less competent immune system (earlier immunosenescence) than those which explore it quickly (fast mice). The present longitudinal study on OF-1 Swiss female mice confirms and extends the above findings. Thus, the animals showing a lower performance in the T-test (slow mice) which is accompanied by a poor neuromuscular coordination in a tightrope test, have a shorter life span than the good performers (fast mice). Moreover, the slow mice have a less competent immune system as regards the following functions of peritoneal macrophages: adherence to substrate, chemotaxis, ingestion of particles and superoxide anion production. This suggests that, at the same chronological age and as regards their immune competence, the slow mice are biologically older than the fast mice. This agrees with current ideas on the close functional relationship between the nervous and the immune system in the physiological adaptation to stress, and supports the concept that an optimum level of performance of these two systems is needed to attain a long life span.

  6. New tetradecyltrimethylammonium-selective electrodes: surface composition and topography as correlated with electrode's life span.

    Science.gov (United States)

    Marafie, Hayat M; Al-Shammari, Tahani F; Shoukry, Adel F

    2012-03-15

    Two conventional plastic membrane electrodes that are selective for the tetradecyltrimethylammonium cation (TTA) have been prepared. The ion exchangers of these sensors were the ion associate, TTA-PT, and the ion aggregate, TTA-PSS, where PT and PSS are phosphotungstate and polystyrene sulfonate, respectively. The following performance characteristics of the TTA-PT- and TTA-PSS-containing electrodes were found: conditioning time of 30 and 20 min; potential response of 58.2 and 61.1 mV/TTA concentration decade; rectilinear concentration ranges of 2.0 × 10(-5)-5.0 × 10(-2) and 1.5 × 10(-5)-7.9 × 10(-2) mol L(-1); average working pH ranges of 4.0-10.5 and 3.8-10.7; life spans of 20 and 28 weeks, and isothermal temperature coefficients of 4.44 × 10(-4) and 6.10 × 10(-4)V/°C, respectively. Both electrodes exhibited high selectivity for TTA with an increasing number of inorganic and quaternary ammonium surfactant cations. These electrodes have been successfully applied to assay an antiseptic formulation containing TTA. Surface analyses using electron microscopy and X-ray photoelectron spectroscopy were used to determine the cause of the limited life span of plastic membrane electrodes.

  7. Chromosomal aberrations, reproductive success, life span, and mortality in irradiated Neanthes arenaceodentata (polychaeta)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S.L.; Harrison, F.L.; Chan, G.; Moore, D.H. II

    1987-10-01

    The polychaete worm Neanthes arenaceodentata ws used in experiments to determine possible relationships between short-term genotoxicity tests and reproductive and lethal consequences of exposure to ionizing radiation. Groups of juvenile N. arenaceodentata received one of four different radiation doses (2, 4, 8, and 16 Gy) to determine dose-effect estimates for chromosomal aberration induction, and groups of both adult and juveniles received one of seven different radiation doses (1, 4, 8.4, 46, 102, 500, and 1000 Gy) to determine dose-effect estimates for reproduction, mortality, and life span. Effects on reproduction and genetic material were observed at the lowest doses and in the same range; detrimental reproductive effects were observed at 1 to 4 Gy, and the frequency of chromosomal aberrations were significantly increased at 2 Gy. Only high doses resulted in acute mortality (>500 Gy) and decreased life span (>100 Gy). Dose-effect estimates for chromosomal aberration induction were dependant on radiation dose and on the stage of the cell cycle at the time of irradiation. Dose-effect estimates for reproduction were dependant on dose and the potential for repopulation of gonadal tissue. Such knowledge is required because factors, such as cell-cycle effects, may modify dose-effect estimates. It is concluded that short-term genotoxicity tests can be predictive of detrimental reproductive effects in those model systems for which basic cell kinetics and reproductive parameters are well known. 4 refs., 11 figs., 13 tabs.

  8. AMPKalpha1 deletion shortens erythrocyte life span in mice: role of oxidative stress.

    Science.gov (United States)

    Wang, Shaobin; Dale, George L; Song, Ping; Viollet, Benoit; Zou, Ming-Hui

    2010-06-25

    AMP-activated protein kinase (AMPK) is an energy sensor essential for maintaining cellular energy homeostasis. Here, we report that AMPKalpha1 is the predominant isoform of AMPK in murine erythrocytes and mice globally deficient in AMPKalpha1 (AMPKalpha1(-/-)), but not in those lacking AMPKalpha2, and the mice had markedly enlarged spleens with dramatically increased proportions of Ter119-positive erythroid cells. Blood tests revealed significantly decreased erythrocyte and hemoglobin levels with increased reticulocyte counts and elevated plasma erythropoietin concentrations in AMPKalpha1(-/-) mice. The life span of erythrocytes from AMPKalpha1(-/-) mice was less than that in wild-type littermates, and the levels of reactive oxygen species and oxidized proteins were significantly increased in AMPKalpha1(-/-) erythrocytes. In keeping with the elevated oxidative stress, treatment of AMPKalpha1(-/-) mice with the antioxidant, tempol, resulted in decreased reticulocyte counts and improved erythrocyte survival. Furthermore, the expression of Foxo3 and reactive oxygen species scavenging enzymes was significantly decreased in erythroblasts from AMPKalpha1(-/-) mice. Collectively, these results establish an essential role for AMPKalpha1 in regulating oxidative stress and life span in erythrocytes.

  9. The effect of developmental nutrition on life span and fecundity depends on the adult reproductive environment in Drosophila melanogaster

    NARCIS (Netherlands)

    May, C.M.; Doroszuk, A.; Zwaan, B.J.

    2015-01-01

    Both developmental nutrition and adult nutrition affect life-history traits; however, little is known about whether the effect of developmental nutrition depends on the adult environment experienced. We used the fruit fly to determine whether life-history traits, particularly life span and fecundity

  10. Developmental Change in the Relation between Simple and Complex Spans: A Meta-Analysis

    Science.gov (United States)

    Tillman, Carin M.

    2011-01-01

    In the present meta-analysis the effects of developmental level on the correlation between simple and complex span tasks were investigated. Simple span-complex span correlation coefficients presented in 52 independent samples (7,060 participants) were regressed on a variable representing mean age of sample (range: 4.96-22.80 years), using analyses…

  11. Older people with incurable cancer: Existential meaning-making from a life-span perspective.

    Science.gov (United States)

    Haug, Sigrid Helene Kjørven; Danbolt, Lars J; Kvigne, Kari; DeMarinis, Valerie

    2016-02-01

    An increasing number of older people in Western countries are living with incurable cancer, receiving palliative care from specialized healthcare contexts. The aim of our article was to understand how they experience the existential meaning-making function in daily living from a life-span perspective. Some 21 participants (12 men and 9 women), aged 70-88, were interviewed in a semistructured framework. They were recruited from somatic hospitals in southeastern Norway. We applied the model of selective optimization with compensation (SOC) from life-span developmental psychology in a deductive manner to explore the participants' life-oriented adaptive strategies. A meaning component was added to the SOC model. The participants experienced the existential meaning-making function on two levels. On a superordinate level, it was an important component for interpreting and coordinating the adaptive strategies of SOC for reaching the most important goals in daily living. The existential meaning-making framework provided for a comprehensive understanding of resilience, allowing for both restoration and growth components to be identified. The second level was related to strategy, in that the existential meaning-making function was involved in a complex interaction with behavioral resources and resilience, leading to continuation of goals and more realistic goal adjustments. A few experienced existential meaning-making dysfunction. The modified SOC model was seen as applicable for palliative care in specialized healthcare contexts. Employing the existential meaning-making framework with its complementary understanding of resilience as growth potential to the SOC model's restoration potential can help older people to identify how they make meaning and how this influences their adaptation process to being incurably sick.

  12. Solid Cancer Incidence among the Life Span Study of Atomic Bomb Survivors: 1958-2009.

    Science.gov (United States)

    Grant, Eric J; Brenner, Alina; Sugiyama, Hiromi; Sakata, Ritsu; Sadakane, Atsuko; Utada, Mai; Cahoon, Elizabeth K; Milder, Caitlin M; Soda, Midori; Cullings, Harry M; Preston, Dale L; Mabuchi, Kiyohiko; Ozasa, Kotaro

    2017-05-01

    This is the third analysis of solid cancer incidence among the Life Span Study (LSS) cohort of atomic bomb survivors in Hiroshima and Nagasaki, adding eleven years of follow-up data since the previously reported analysis. For this analysis, several changes and improvements were implemented, including updated dose estimates (DS02R1) and adjustment for smoking. Here, we focus on all solid cancers in aggregate. The eligible cohort included 105,444 subjects who were alive and had no known history of cancer at the start of follow-up. A total of 80,205 subjects had individual dose estimates and 25,239 were not in either city at the time of the bombings. The follow-up period was 1958-2009, providing 3,079,484 person-years of follow-up. Cases were identified by linkage with population-based Hiroshima and Nagasaki Cancer Registries. Poisson regression methods were used to elucidate the nature of the radiation-associated risks per Gy of weighted absorbed colon dose using both excess relative risk (ERR) and excess absolute risk (EAR) models adjusted for smoking. Risk estimates were reported for a person exposed at age 30 years with attained age of 70 years. In this study, 22,538 incident first primary solid cancer cases were identified, of which 992 were associated with radiation exposure. There were 5,918 cases (26%) that occurred in the 11 years (1999-2009) since the previously reported study. For females, the dose response was consistent with linearity with an estimated ERR of 0.64 per Gy (95% CI: 0.52 to 0.77). For males, significant upward curvature over the full dose range as well as restricted dose ranges was observed and therefore, a linear-quadratic model was used, which resulted in an ERR of 0.20 (95% CI: 0.12 to 0.28) at 1 Gy and an ERR of 0.010 (95% CI: -0.0003 to 0.021) at 0.1 Gy. The shape of the ERR dose response was significantly different among males and females (P = 0.02). While there was a significant decrease in the ERR with increasing attained age, this

  13. [Psychoneuroimmunology of the life span: impact of childhood stress on immune dysregulation and inflammatory disease in later life].

    Science.gov (United States)

    Schubert, Christian

    2014-05-01

    Studies have shown clearly that childhood mistreatment, abuse and neglect are associated with severe inflammatory disease in adulthood (e. g. cancer, heart disease, autoimmune disorder) and shortened life span. This review deals with the psychoneuroimmunological pathways of this connection. It shows that chronic stressors interfere very early in life with those protective mechanisms of the biological stress system that normally down-regulate potentially harmful inflammation. In the long term, serious inflammatory diseases, such as allergic asthma, can result. In this review, the pathogenetic connections between allergic asthma and early stress and stress system dysfunction are discussed. As our understanding of the dysfunctional psychophysiological mechanisms of inflammatory disease increases, psychodiagnostic and psychotherapeutic intervention in the treatment of physical disease will become more specific.

  14. Nutrition through the life-span. Part 1: preconception, pregnancy and infancy.

    Science.gov (United States)

    Shepherd, Alison Anne

    Good nutrition throughout the life-span is fundamental if infants are to grow into healthy adults with subsequent progression through to old age. However, with an alarming increase in both the rates of obesity and malnutrition, it would seem prudent to suggest that infants, children and adults are not achieving an adequate nutritional status. This article is part one of a two-part series which aims to educate nurses by giving some guidelines on how such individuals may achieve a healthy nutritional status right through from preconception, pregnancy, infancy and childhood, through to adulthood and old age. It should always be remembered that although nurses are in a prime position to identify and treat malnutrition, it is not just a nursing responsibility. Safe and effective nutritional care can only be delivered if all those involved in the care of the patient - dieticians, nutritionists, doctors and pharmacists - are working together.

  15. Invited commentary: missing doses in the life span study of Japanese atomic bomb survivors.

    Science.gov (United States)

    Ozasa, K; Grant, E J; Cullings, H M; Shore, R E

    2013-03-15

    The Life Span Study is a long-term epidemiologic cohort study of survivors of the atomic bombs dropped on Hiroshima and Nagasaki, Japan. In this issue of the Journal, Richardson et al. (Am J Epidemiol. 2013;177(6):562-568) suggest that those who died in the earliest years of follow-up were more likely to have a missing dose of radiation exposure assigned, leading to a bias in the radiation risk estimates. We show that nearly all members of the cohort had shielding information recorded before the beginning of follow-up and that much of the alleged bias that Richardson et al. describe simply reflects the geographic distribution of shielding conditions for which reliable dosimetry was impossible.

  16. The impact of invisible illness on identity and contextual age across the life span.

    Science.gov (United States)

    Kundrat, Amanda L; Nussbaum, Jon F

    2003-01-01

    This study explored the impact invisible illness has on identity, specifically contextual age, throughout the life span. It was grounded in the assumption that an individual's identity is formed through communicative interaction. Using social identity theory (Tajfel & Turner, 1986) as a framework, individuals' identities after disclosure of invisible illness were explored. Rubin and Rubin's (1986) Contextual Age Questionnaire was used to determine self-perceived as well as other-perceived contextual age. Invisibly ill individuals reported significantly "higher" contextual age scores than did same chronologically aged, matched non-ill individuals. In addition, the friends of invisibly ill individuals reported "higher" contextual age scores for the invisibly ill individuals than the self-reported scores of the same chronologically aged non-ill individuals. Interviews further revealed that illness instilled insight and that disclosure of illness provoked comments from others that led invisibly ill individuals to identify with older individuals. Future directions and limitations of this study are also discussed.

  17. The Verriest Lecture: Short-wave-sensitive cone pathways across the life span.

    Science.gov (United States)

    Werner, John S

    2016-03-01

    Structurally and functionally, the short-wave-sensitive (S) cone pathways are thought to decline more rapidly with normal aging than the middle- and long-wave-sensitive cone pathways. This would explain the celebrated results by Verriest and others demonstrating that the largest age-related color discrimination losses occur for stimuli on a tritan axis. Here, we challenge convention, arguing from psychophysical data that selective S-cone pathway losses do not cause declines in color discrimination. We show substantial declines in chromatic detection and discrimination, as well as in temporal and spatial vision tasks, that are mediated by S-cone pathways. These functional losses are not, however, unique to S-cone pathways. Finally, despite reduced photon capture by S cones, their postreceptoral pathways provide robust signals for the visual system to renormalize itself to maintain nearly stable color perception across the life span.

  18. Estimates for the number of visible galaxy-spanning civilizations and the cosmological expansion of life

    CERN Document Server

    Olson, S Jay

    2015-01-01

    If advanced civilizations appear in the universe with a desire to expand, the entire universe can become saturated with life on a short timescale, even if such expanders appear but rarely. Our presence in an untouched Milky Way thus constrains the appearance rate of galaxy-spanning Kardashev type III (K3) civilizations, if it is assumed that some fraction of K3 civilizations will continue their expansion at intergalactic distances. We use this constraint to estimate the appearance rate of K3 civilizations for 81 cosmological scenarios by specifying the extent to which humanity could be a statistical outlier. We find that in nearly all plausible scenarios, the distance to the nearest visible K3 is cosmological. In searches where the observable range is limited, we also find that the most likely detections tend to be expanding civilizations who have entered the observable range from farther away. An observation of K3 clusters is thus more likely than isolated K3 galaxies.

  19. Biological impact of auditory expertise across the life span: musicians as a model of auditory learning.

    Science.gov (United States)

    Strait, Dana L; Kraus, Nina

    2014-02-01

    Experience-dependent characteristics of auditory function, especially with regard to speech-evoked auditory neurophysiology, have garnered increasing attention in recent years. This interest stems from both pragmatic and theoretical concerns as it bears implications for the prevention and remediation of language-based learning impairment in addition to providing insight into mechanisms engendering experience-dependent changes in human sensory function. Musicians provide an attractive model for studying the experience-dependency of auditory processing in humans due to their distinctive neural enhancements compared to nonmusicians. We have only recently begun to address whether these enhancements are observable early in life, during the initial years of music training when the auditory system is under rapid development, as well as later in life, after the onset of the aging process. Here we review neural enhancements in musically trained individuals across the life span in the context of cellular mechanisms that underlie learning, identified in animal models. Musicians' subcortical physiologic enhancements are interpreted according to a cognitive framework for auditory learning, providing a model in which to study mechanisms of experience-dependent changes in human auditory function.

  20. Virtual navigation strategies from childhood to senescence: evidence for changes across the life span

    Directory of Open Access Journals (Sweden)

    Veronique D Bohbot

    2012-11-01

    Full Text Available This study sought to investigate navigational strategies across the life span, by testing 8-year old children to 80-year old healthy older adults on the 4 on 8 virtual maze (4/8VM. The 4/8VM was previously developed to assess spontaneous navigational strategies, i.e. hippocampal-dependent spatial strategies (navigation by memorizing relationships between landmarks versus caudate nucleus-dependent response strategies (memorizing a series of left and right turns from a given starting position. With the 4/8VM, we previously demonstrated greater fMRI activity and grey matter in the hippocampus of spatial learners relative to response learners. A sample of 599 healthy participants was tested in the current study. Results showed that 84.4% of children, 46.3% of young adults, and 39.3% of older adults spontaneously used spatial strategies (p < 0.0001. Our results suggest that while children predominantly use spatial strategies, the proportion of participants using spatial strategies decreases across the life span, in favor of response strategies. Factors promoting response strategies include repetition, reward and stress. Since response strategies can result from successful repetition of a behavioral pattern, we propose that the increase in response strategies is a biological adaptive mechanism that allows for the automatization of behavior such as walking in order to free up hippocampal-dependent resources. However, the downside of this shift from spatial to response strategies occurs if people stop building novel relationships, which occurs with repetition and routine, and thereby stop stimulating their hippocampus. Reduced fMRI activity and grey matter in the hippocampus were shown to correlate with cognitive deficits in normal aging. Therefore, these results have important implications regarding factors involved in healthy and successful aging.

  1. Age- and calorie-independent life span extension from dietary restriction by bacterial deprivation in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Sager Jennifer

    2008-05-01

    Full Text Available Abstract Background Dietary restriction (DR increases life span and delays age-associated disease in many organisms. The mechanism by which DR enhances longevity is not well understood. Results Using bacterial food deprivation as a means of DR in C. elegans, we show that transient DR confers long-term benefits including stress resistance and increased longevity. Consistent with studies in the fruit fly and in mice, we demonstrate that DR also enhances survival when initiated late in life. DR by bacterial food deprivation significantly increases life span in worms when initiated as late as 24 days of adulthood, an age at which greater than 50% of the cohort have died. These survival benefits are, at least partially, independent of food consumption, as control fed animals are no longer consuming bacterial food at this advanced age. Animals separated from the bacterial lawn by a barrier of solid agar have a life span intermediate between control fed and food restricted animals. Thus, we find that life span extension from bacterial deprivation can be partially suppressed by a diffusible component of the bacterial food source, suggesting a calorie-independent mechanism for life span extension by dietary restriction. Conclusion Based on these findings, we propose that dietary restriction by bacterial deprivation increases longevity in C. elegans by a combination of reduced food consumption and decreased food sensing.

  2. Expressions of ecological identity across the life span of eight environmental exemplars

    Science.gov (United States)

    Seydel, Jennifer

    While there is a substantial body of literature looking at various aspects of ecological identity and factors that influence it, there has been less work done on how an individual's ecological identity changes with time. Much of that work is limited to short segments of the life span (e.g. the impact of wilderness experiences). This dissertation attempts to address this perceived gap by investigating how the ecological identity of eight environmental exemplars changed during the course of his or her life. What has emerged from this qualitative grounded theory investigation of the lives and works of Charles Darwin, John Muir, Aldo Leopold, Marjory Stoneman Douglas, Hazel Wolf, Rachel Carson, James Lovelock and E.O. Wilson are five sequential expressions of ecological identity. These 'stages' serve as a framework to explain ecological identity as a developmental process, both fluid and continuous, rather than at) end product. The development of an ecological identity is traced, through the development of five cognitive foundations and their alignment with five emotional foundations that reflect a progression from a sensory interaction and a kinship bond with nature into a deep understanding of the interconnectedness of all aspects of the planet. The findings reveal the evolution of an ecological identity and suggest the importance of looking beyond content knowledge in the nurturing of ecological attitudes, values, and lifestyles.

  3. Dietary resveratrol prevents Alzheimer's markers and increases life span in SAMP8.

    Science.gov (United States)

    Porquet, David; Casadesús, Gemma; Bayod, Sergi; Vicente, Alberto; Canudas, Anna M; Vilaplana, Jordi; Pelegrí, Carme; Sanfeliu, Coral; Camins, Antoni; Pallàs, Mercè; del Valle, Jaume

    2013-10-01

    Resveratrol is a polyphenol that is mainly found in grapes and red wine and has been reported to be a caloric restriction (CR) mimetic driven by Sirtuin 1 (SIRT1) activation. Resveratrol increases metabolic rate, insulin sensitivity, mitochondrial biogenesis and physical endurance, and reduces fat accumulation in mice. In addition, resveratrol may be a powerful agent to prevent age-associated neurodegeneration and to improve cognitive deficits in Alzheimer's disease (AD). Moreover, different findings support the view that longevity in mice could be promoted by CR. In this study, we examined the role of dietary resveratrol in SAMP8 mice, a model of age-related AD. We found that resveratrol supplements increased mean life expectancy and maximal life span in SAMP8 and in their control, the related strain SAMR1. In addition, we examined the resveratrol-mediated neuroprotective effects on several specific hallmarks of AD. We found that long-term dietary resveratrol activates AMPK pathways and pro-survival routes such as SIRT1 in vivo. It also reduces cognitive impairment and has a neuroprotective role, decreasing the amyloid burden and reducing tau hyperphosphorylation.

  4. Aging Theories for Establishing Safe Life Spans of Airborne Critical Structural Components

    Science.gov (United States)

    Ko, William L.

    2003-01-01

    New aging theories have been developed to establish the safe life span of airborne critical structural components such as B-52B aircraft pylon hooks for carrying air-launch drop-test vehicles. The new aging theories use the equivalent-constant-amplitude loading spectrum to represent the actual random loading spectrum with the same damaging effect. The crack growth due to random loading cycling of the first flight is calculated using the half-cycle theory, and then extrapolated to all the crack growths of the subsequent flights. The predictions of the new aging theories (finite difference aging theory and closed-form aging theory) are compared with the classical flight-test life theory and the previously developed Ko first- and Ko second-order aging theories. The new aging theories predict the number of safe flights as considerably lower than that predicted by the classical aging theory, and slightly lower than those predicted by the Ko first- and Ko second-order aging theories due to the inclusion of all the higher order terms.

  5. Chips in black boxes? Convenience life span, parafood, brandwidth, families, and co-creation.

    Science.gov (United States)

    Jacobs, Marc

    2015-11-01

    Any consumer who opens a bag of potato or corn chips (or crisps in the UK) knows there is no time to waste to enjoy or share them. The convenience life span of chips is limited: it is the shelf or storage life and a very limited time once outside the bag. Many technologies converge to generate the desired effect as a black box, not only of the packaging but also of the chips themselves. The concept of paratext can be applied to printed messages on the package, including the brand name and other texts like advertising (epitexts), which can be expanded into the concept of parafood. These concepts help to discuss technological developments and interpret why this has recently become a negotiation zone for co-creation (see the Do us a flavor campaigns). They are symptoms of changing relations between production, research and development, marketing, and consumption. This paper pays special attention to back stories, underdog brand biographies and narratives about origin. The concept of brandwidth is introduced to sensitize about the limits of combining different stories about chips. A recent brand biography, a family history and a cookery book are used to discuss the phenomenon of cooking with Fritos. Together with the concepts of parafood, brandwidth and black boxes, more reflection and dialogue about the role of history and heritage in marketing put new challenging perspectives on the agenda.

  6. Refugees 's experiences across a life span : a qualitative study of perceived resources and demands among Iranian refugees in Norway

    OpenAIRE

    Sattarzadeh, Solmaz

    2009-01-01

    This study explored the experiences of Iranian refugees across their life span in Norway. More specifically, the aim was to identify what resources and demands were encountered in each period of the asylum seeking, the resettlement, and the present life of Iranian refugees and how participants perceived and experienced these resources and demands. A qualitative approach, was used to capture in detail the life experiences of individuals. Nine Iranian refugees coming to Norway as asylum seekers...

  7. Sex-specific Tradeoffs With Growth and Fitness Following Life-span Extension by Rapamycin in an Outcrossing Nematode, Caenorhabditis remanei.

    Science.gov (United States)

    Lind, Martin I; Zwoinska, Martyna K; Meurling, Sara; Carlsson, Hanne; Maklakov, Alexei A

    2016-07-01

    Rapamycin inhibits the nutrient-sensing TOR pathway and extends life span in a wide range of organisms. Although life-span extension usually differs between the sexes, the reason for this is poorly understood. Because TOR influences growth, rapamycin likely affects life-history traits such as growth and reproduction. Sexes have different life-history strategies, and theory predicts that they will resolve the tradeoffs between growth, reproduction, and life span differently. Specifically, in taxa with female-biased sexual size dimorphism, reduced growth may have smaller effects on male fitness. We investigated the effects of juvenile, adult, or life-long rapamycin treatment on growth, reproduction, life span, and individual fitness in the outcrossing nematode Caenorhabditis remanei Life-long exposure to rapamycin always resulted in the strongest response, whereas postreproductive exposure did not affect life span. Although rapamycin resulted in longer life span and smaller size in males, male individual fitness was not affected. In contrast, size and fitness were negatively affected in females, whereas life span was only extended under high rapamycin concentrations. Our results support the hypothesis that rapamycin affects key life-history traits in a sex-specific manner. We argue that the fitness cost of life-span extension will be sex specific and propose that the smaller sex generally pay less while enjoying stronger life-span increase.

  8. Offspring Provisioning Explains Clone-Specific Maternal Age Effects on Life History and Life Span in the Water Flea, Daphnia pulex.

    Science.gov (United States)

    Plaistow, Stewart J; Shirley, Christopher; Collin, Helene; Cornell, Stephen J; Harney, Ewan D

    2015-09-01

    Genetic inheritance underpins evolutionary theories of aging, but the role that nongenetic inheritance plays is unclear. Parental age reduces the life span of offspring in a diverse array of taxa but has not been explained from an evolutionary perspective. We quantified the effect that maternal age had on the growth and maturation decisions, life history, rates of senescence, and life span of offspring from three Daphnia pulex clones collected from different populations. We then used those data to test general hypotheses proposed to explain maternal age effects on offspring life span. Three generations of breeding from young or old mothers produced dramatic differences in the life histories of fourth-generation offspring, including significant reductions in life span. The magnitude of the effect differed between clones, which suggests that genetic and nongenetic factors ultimately underpin trait inheritance and shape patterns of aging. Older parents did not transmit a senescent state to their offspring. Instead, offspring from older ancestors had increased early-life reproductive effort, which resulted in an earlier onset of reproductive senescence, and an increased rate of actuarial senescence, which shortened their life span. Our results provide a clear example of the need to consider multiple inheritance mechanisms when studying trait evolution.

  9. Genetic regulation of life span, metabolism, and body weight in Pohn, a new wild-derived mouse strain.

    Science.gov (United States)

    Yuan, Rong; Flurkey, Kevin; Meng, Qingying; Astle, Mike C; Harrison, David E

    2013-01-01

    Quantitative trait loci (QTL) of longevity identified in human and mouse are significantly colocalized, suggesting that common mechanisms are involved. However, the limited number of strains that have been used in mouse longevity studies undermines the ability to identify longevity genes. We crossed C57BL/6J mice with a new wild-derived strain, Pohn, and identified two life span QTL-Ls1 and Ls2. Interestingly, homologous human longevity QTL colocalize with Ls1. We also defined new QTL for metabolic heat production and body weight. Both phenotypes are significantly correlated with life span. We found that large clone ratio, an in vitro indicator for cellular senescence, is not correlated with life span, suggesting that cell senescence and intrinsic aging are not always associated. Overall, by using Pohn mice, we identified new QTL for longevity-related traits, thus facilitating the exploration of the genetic regulation of aging.

  10. A finite element solver for modal analysis of multi-span offshore pipelines

    OpenAIRE

    2014-01-01

    Accurate determination of pipeline eigenfrequencies and mode shapes is essential to free span design. For pipelines resting on rough seabeds, multiple free spans are commonly located sufficiently close to be interacting, and finite element analysis (FEA) is then conventionally required to determine the modal response. In the present report, a tailor-made (specific purpose) FEA tool is developed to carry out modal analyses of multi-span offshore pipelines. The specific purpose FEA tool is thor...

  11. Dietary intake of Curcuma longa and Emblica officinalis increases life span in Drosophila melanogaster.

    Science.gov (United States)

    Rawal, Shilpa; Singh, Pavneet; Gupta, Ayush; Mohanty, Sujata

    2014-01-01

    Intake of food and nutrition plays a major role in affecting aging process and longevity. However, the precise mechanisms underlying the ageing process are still unclear. To this respect, diet has been considered to be a determinant of ageing process. In order to better illustrate this, we used Drosophila melanogaster as a model and fed them orally with different concentrations of two commonly used Indian medicinal plant products, Curcuma longa (rhizome) and Emblica officinalis (fruit). The results revealed significant increase in life span of Drosophila flies on exposure to both the plant products, more efficiently by C. Longa than by E. officinalis. In order to understand whether the increase in lifespan was due to high-antioxidant properties of these medicinal plants, we performed enzymatic assays to assess the SOD and catalase activities in case of both treated and control Drosophila flies. Interestingly, the results support the free radical theory of aging as both these plant derivatives show high reactive oxygen species (ROS) scavenging activities.

  12. Cognitive control and language across the life span: does labeling improve reactive control?

    Science.gov (United States)

    Lucenet, Joanna; Blaye, Agnès; Chevalier, Nicolas; Kray, Jutta

    2014-05-01

    How does cognitive control change with age, and what are the processes underlying these changes? This question has been extensively studied using versions of the task-switching paradigm, which allow participants to actively prepare for the upcoming task (Kray, Eber, & Karbach, 2008). Little is known, however, about age-related changes in this ability across the life span when there is no opportunity to anticipate task goals. We examined the effect of 2 kinds of verbal self-instruction-labeling either the task goal or the relevant feature of the stimulus-on 2 components of cognitive control, goal setting and switching, in children, young adults, and older adults. All participants performed single-task blocks and mixed-task blocks (involving unpredictable switching between 2 tasks) in silent and labeling conditions. Participants categorized bidimensional stimuli either by picture or by color, depending on their spatial position in a 2-cell vertical grid. Response times revealed an inverted U shape in performance with age. These age differences were more pronounced for goal setting than for switching, thus generalizing results obtained in situations taping proactive control to this new context forcing reactive control. Further, differential age-related effects of verbalization were also obtained. Verbalizations were detrimental for young adults, beneficial for older adults, and had mixed effects in children. These differences are interpreted in terms of qualitative developmental changes in reactive goal-setting strategies. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  13. The decline of verbal and visuospatial working memory across the adult life span.

    Science.gov (United States)

    Cansino, Selene; Hernández-Ramos, Evelia; Estrada-Manilla, Cinthya; Torres-Trejo, Frine; Martínez-Galindo, Joyce Graciela; Ayala-Hernández, Mariana; Gómez-Fernández, Tania; Osorio, David; Cedillo-Tinoco, Melisa; Garcés-Flores, Lissete; Beltrán-Palacios, Karla; García-Lázaro, Haydée Guadalupe; García-Gutiérrez, Fabiola; Cadena-Arenas, Yadira; Fernández-Apan, Luisa; Bärtschi, Andrea; Rodríguez-Ortiz, María Dolores

    2013-12-01

    It has been well established that working memory abilities decrease with advancing age; however, the specific time point in the adult life span at which this deficit begins and the rate at which it advances are still controversial. There is no agreement on whether working memory declines equally for visuospatial and verbal information, and the literature disagrees on how task difficulty may influence this decay. We addressed these questions in a lifespan sample of 1,500 participants between 21 and 80 years old. The n-back task was used, with letters and circles presented at different positions around an imaginary circle, to evaluate working memory in the verbal and visuospatial domains, respectively. The participants' task was to judge whether the current stimulus matched a stimulus that was shown n trials prior. Both domains were evaluated in two levels of difficulty: 1-back and 2-back. The comparison across decades showed that discrimination in the visuospatial and 1-back tasks started to decline earlier in women than in men; however, discrimination was equal between the sexes in the verbal and 2-back tasks. Performance on tasks in the visuospatial domain exhibited more pronounced decline than in those in the verbal domain. The rate of decline in working memory accuracy was superior in 2-back tasks than in 1-back tasks, independent of the domain. These results revealed that the effects of aging on working memory are less dependent on the type of information and more reliant on the resources demanded by the task.

  14. Childhood Adversity, Self-Esteem, and Diurnal Cortisol Profiles Across the Life Span.

    Science.gov (United States)

    Zilioli, Samuele; Slatcher, Richard B; Chi, Peilian; Li, Xiaoming; Zhao, Junfeng; Zhao, Guoxiang

    2016-09-01

    Childhood adversity is associated with poor health outcomes in adulthood; the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as a crucial biological intermediary of these long-term effects. Here, we tested whether childhood adversity was associated with diurnal cortisol parameters and whether this link was partially explained by self-esteem. In both adults and youths, childhood adversity was associated with lower levels of cortisol at awakening, and this association was partially driven by low self-esteem. Further, we found a significant indirect pathway through which greater adversity during childhood was linked to a flatter cortisol slope via self-esteem. Finally, youths who had a caregiver with high self-esteem experienced a steeper decline in cortisol throughout the day compared with youths whose caregiver reported low self-esteem. We conclude that self-esteem is a plausible psychological mechanism through which childhood adversity may get embedded in the activity of the HPA axis across the life span.

  15. Atomic Bomb Survivors Life-Span Study: Insufficient Statistical Power to Select Radiation Carcinogenesis Model.

    Science.gov (United States)

    Socol, Yehoshua; Dobrzyński, Ludwik

    2015-01-01

    The atomic bomb survivors life-span study (LSS) is often claimed to support the linear no-threshold hypothesis (LNTH) of radiation carcinogenesis. This paper shows that this claim is baseless. The LSS data are equally or better described by an s-shaped dependence on radiation exposure with a threshold of about 0.3 Sievert (Sv) and saturation level at about 1.5 Sv. A Monte-Carlo simulation of possible LSS outcomes demonstrates that, given the weak statistical power, LSS cannot provide support for LNTH. Even if the LNTH is used at low dose and dose rates, its estimation of excess cancer mortality should be communicated as 2.5% per Sv, i.e., an increase of cancer mortality from about 20% spontaneous mortality to about 22.5% per Sv, which is about half of the usually cited value. The impact of the "neutron discrepancy problem" - the apparent difference between the calculated and measured values of neutron flux in Hiroshima - was studied and found to be marginal. Major revision of the radiation risk assessment paradigm is required.

  16. Speech rate effects on the processing of conversational speech across the adult life span.

    Science.gov (United States)

    Koch, Xaver; Janse, Esther

    2016-04-01

    This study investigates the effect of speech rate on spoken word recognition across the adult life span. Contrary to previous studies, conversational materials with a natural variation in speech rate were used rather than lab-recorded stimuli that are subsequently artificially time-compressed. It was investigated whether older adults' speech recognition is more adversely affected by increased speech rate compared to younger and middle-aged adults, and which individual listener characteristics (e.g., hearing, fluid cognitive processing ability) predict the size of the speech rate effect on recognition performance. In an eye-tracking experiment, participants indicated with a mouse-click which visually presented words they recognized in a conversational fragment. Click response times, gaze, and pupil size data were analyzed. As expected, click response times and gaze behavior were affected by speech rate, indicating that word recognition is more difficult if speech rate is faster. Contrary to earlier findings, increased speech rate affected the age groups to the same extent. Fluid cognitive processing ability predicted general recognition performance, but did not modulate the speech rate effect. These findings emphasize that earlier results of age by speech rate interactions mainly obtained with artificially speeded materials may not generalize to speech rate variation as encountered in conversational speech.

  17. From past to future: Temporal self-continuity across the life span.

    Science.gov (United States)

    Rutt, Joshua L; Löckenhoff, Corinna E

    2016-09-01

    Although perceived continuity with one's future self has attracted increasing research interest, age differences in this phenomenon remain poorly understood. The present study is the first to simultaneously examine past and future self-continuity across multiple temporal distances using both explicit and implicit measures and controlling for a range of theoretically implicated covariates in an adult life span sample (N = 91, aged 18-92, M = 50.15, SD = 19.20, 56% female). Perceived similarity to one's self across 6 past and 6 future time points (1 month to 10 years) was assessed with an explicit self-report measure and an implicit me/not me trait rating task. In multilevel analyses, age was significantly associated with greater implicit and explicit self-continuity, especially for more distant intervals. Further, reaction times (RTs) in the implicit task remained stable with temporal distance for older adults but decreased with temporal distance for younger adults, especially for future ratings. This points toward age differences in the underlying mechanisms of self-continuity. Multilevel models examined the role of various covariates including personality, cognition, future horizons, and subjective health and found that none of them could fully account for the observed age effects. Taken together, our findings suggest that chronological age is associated with greater self-continuity although specific mechanisms and correlates may vary by age. (PsycINFO Database Record

  18. Atrx deficiency induces telomere dysfunction, endocrine defects, and reduced life span.

    Science.gov (United States)

    Watson, L Ashley; Solomon, Lauren A; Li, Jennifer Ruizhe; Jiang, Yan; Edwards, Matthew; Shin-ya, Kazuo; Beier, Frank; Bérubé, Nathalie G

    2013-05-01

    Human ATRX mutations are associated with cognitive deficits, developmental abnormalities, and cancer. We show that the Atrx-null embryonic mouse brain accumulates replicative damage at telomeres and pericentromeric heterochromatin, which is exacerbated by loss of p53 and linked to ATM activation. ATRX-deficient neuroprogenitors exhibited higher incidence of telomere fusions and increased sensitivity to replication stress-inducing drugs. Treatment of Atrx-null neuroprogenitors with the G-quadruplex (G4) ligand telomestatin increased DNA damage, indicating that ATRX likely aids in the replication of telomeric G4-DNA structures. Unexpectedly, mutant mice displayed reduced growth, shortened life span, lordokyphosis, cataracts, heart enlargement, and hypoglycemia, as well as reduction of mineral bone density, trabecular bone content, and subcutaneous fat. We show that a subset of these defects can be attributed to loss of ATRX in the embryonic anterior pituitary that resulted in low circulating levels of thyroxine and IGF-1. Our findings suggest that loss of ATRX increases DNA damage locally in the forebrain and anterior pituitary and causes tissue attrition and other systemic defects similar to those seen in aging.

  19. Life-span extension by dietary restriction is mediated by NLP-7 signaling and coelomocyte endocytosis in C. elegans.

    Science.gov (United States)

    Park, Sang-Kyu; Link, Christopher D; Johnson, Thomas E

    2010-02-01

    Recent studies have shown that the rate of aging can be modulated by diverse interventions. Dietary restriction is the most widely used intervention to promote longevity; however, the mechanisms underlying the effect of dietary restriction remain elusive. In a previous study, we identified two novel genes, nlp-7 and cup-4, required for normal longevity in Caenorhabditis elegans. nlp-7 is one of a set of neuropeptide-like protein genes; cup-4 encodes an ion-channel involved in endocytosis by coelomocytes. Here, we assess whether nlp-7 and cup-4 mediate longevity increases by dietary restriction. RNAi of nlp-7 or cup-4 significantly reduces the life span of the eat-2 mutant, a genetic model of dietary restriction, but has no effect on the life span of long-lived mutants resulting from reduced insulin/IGF-1 signaling or dysfunction of the mitochondrial electron transport chain. The life-span extension observed in wild-type N2 worms by dietary restriction using bacterial dilution is prevented significantly in nlp-7 and cup-4 mutants. RNAi knockdown of genes encoding candidate receptors of NLP-7 and genes involved in endocytosis by coelomocytes also specifically shorten the life span of the eat-2 mutant. We conclude that two novel pathways, NLP-7 signaling and endocytosis by coelomocytes, are required for life extension under dietary restriction in C. elegans.

  20. Statistical modeling of biomedical corpora: mining the Caenorhabditis Genetic Center Bibliography for genes related to life span

    Directory of Open Access Journals (Sweden)

    Jordan MI

    2006-05-01

    Full Text Available Abstract Background The statistical modeling of biomedical corpora could yield integrated, coarse-to-fine views of biological phenomena that complement discoveries made from analysis of molecular sequence and profiling data. Here, the potential of such modeling is demonstrated by examining the 5,225 free-text items in the Caenorhabditis Genetic Center (CGC Bibliography using techniques from statistical information retrieval. Items in the CGC biomedical text corpus were modeled using the Latent Dirichlet Allocation (LDA model. LDA is a hierarchical Bayesian model which represents a document as a random mixture over latent topics; each topic is characterized by a distribution over words. Results An LDA model estimated from CGC items had better predictive performance than two standard models (unigram and mixture of unigrams trained using the same data. To illustrate the practical utility of LDA models of biomedical corpora, a trained CGC LDA model was used for a retrospective study of nematode genes known to be associated with life span modification. Corpus-, document-, and word-level LDA parameters were combined with terms from the Gene Ontology to enhance the explanatory value of the CGC LDA model, and to suggest additional candidates for age-related genes. A novel, pairwise document similarity measure based on the posterior distribution on the topic simplex was formulated and used to search the CGC database for "homologs" of a "query" document discussing the life span-modifying clk-2 gene. Inspection of these document homologs enabled and facilitated the production of hypotheses about the function and role of clk-2. Conclusion Like other graphical models for genetic, genomic and other types of biological data, LDA provides a method for extracting unanticipated insights and generating predictions amenable to subsequent experimental validation.

  1. Human adipose tissue derived pericytes increase life span in Utrn (tm1Ked) Dmd (mdx) /J mice.

    Science.gov (United States)

    Valadares, M C; Gomes, J P; Castello, G; Assoni, A; Pellati, M; Bueno, C; Corselli, M; Silva, H; Bartolini, P; Vainzof, M; Margarido, P F; Baracat, E; Péault, B; Zatz, M

    2014-12-01

    Duchenne muscular dystrophy (DMD) is still an untreatable lethal X-linked disorder, which affects 1 in 3500 male births. It is caused by the absence of muscle dystrophin due to mutations in the dystrophin gene. The potential regenerative capacity as well as immune privileged properties of mesenchymal Stem Cells (MSC) has been under investigation for many years in an attempt to treat DMD. One of the questions to be addressed is whether stem cells from distinct sources have comparable clinical effects when injected in murine or canine muscular dystrophy animal models. Many studies comparing different stem cells from various sources were reported but these cells were obtained from different donors and thus with different genetic backgrounds. Here we investigated whether human pericytes obtained from 4 different tissues (muscle, adipose tissue, fallopian tube and endometrium) from the same donor have a similar clinical impact when injected in double mutant Utrn (tm1Ked) Dmd (mdx) /J mice, a clinically relevant model for DMD. After a weekly regimen of intraperitoneal injections of 10(6) cells per 8 weeks we evaluated the motor ability as well as the life span of the treated mice as compared to controls. Our experiment showed that only adipose tissue derived pericytes are able to increase significantly (39 days on average) the life span of affected mice. Microarray analysis showed an inhibition of the interferon pathway by adipose derived pericytes. Our results suggest that the clinical benefit associated with intraperitoneal injections of these adult stem cells is related to immune modulation rather than tissue regeneration.

  2. Entropy Stress and Scaling of Vital Organs over Life Span Based on Allometric Laws

    Directory of Open Access Journals (Sweden)

    Carlos Silva

    2012-12-01

    Full Text Available Abstract: Past theories on total lifetime energy expenditures and entropy generation in biological systems (BS dealt with whole systems, but the recent literature suggests that the total metabolic rate of a BS,q̇body (W is a sum of product of specific metabolic rate q̇k,m (W/kg of organ k of each vital life organ, k {k = brain, heart, kidney and liver, or abbreviated as BHKL, and rest of the organ mass (R} and mass of each organ k (mk. Using this hypothesis, Kleiber’s law on metabolic rate of BS (q̇body for animals of different sizes was validated. In this work, a similar procedure is adopted in estimating total entropy generation rate of whole human body (σ̇body, W/K as a sum of product of specific entropy generation rate for each organ, σ̇k,m (W/{K kg of organ k·} and the organ mass at any given age (t. Further integrating over life span for each organ (tlife, the lifetime specific entropy generated by organ k, σk,m,life (J of organ k/ {K kg organ k} is calculated. Then lifetime entropy generation of unit body mass, σbody,M,life (J/{K kg body mass·} is calculated as a sum of the corresponding values contributed by all vital organs to unit body mass and verified with previously published literature. The higher the σk,m,life , the higher the entropy stress level (which is a measure of energy released by unit organ mass of k as heat and the irreversibility within the organ, resulting in faster degradation of organ and the consequent health problems for the whole BS. In order to estimate σ̇k (W/K of organ k, data on energy release rate (q̇ is needed over lifetime for each organ. While the Adequate Macronutrients Distribution Range (AMDR/Adequate Intake (AI publication can be used in estimating the energy intake of whole body vs. age for the human body, the energy expenditure data is not available at organ level. Hence the σk,m,life was computed using existing allometric laws developed for the metabolism of the organs, the

  3. Proteomic profiles reveal age-related changes in coelomic fluid of sea urchin species with different life spans.

    Science.gov (United States)

    Bodnar, Andrea

    2013-05-01

    Sea urchins have a different life history from humans and traditional model organisms used to study the process of aging. Sea urchins grow indeterminately, reproduce throughout their life span and some species have been shown to exhibit negligible senescence with no increase in mortality rate at advanced ages. Despite these properties, different species of sea urchins are reported to have very different natural life spans providing a unique model to investigate cellular mechanisms underlying life span determination and negligible senescence. To gain insight into the biological changes that accompany aging in these animals, proteomic profiles were examined in coelomic fluid from young and old sea urchins of three species with different life spans: short-lived Lytechinus variegatus, long-lived Strongylocentrotus franciscanus and Strongylocentrotus purpuratus which has an intermediate life span. The proteomic profiles of cell-free coelomic fluid were complex with many proteins exhibiting different forms and extensive post-translational modifications. Approximately 20% of the protein spots on 2-D gels showed more than two-fold change with age in each of the species. Changes that are consistent with age in all three species may prove to be useful biomarkers for age-determination for these commercially fished marine invertebrates and also may provide clues to mechanisms of negligible senescence. Among the proteins that change with age, the ectodomain of low-density lipoprotein receptor-related protein 4 (LRP4) was significantly increased in the coelomic fluid of all three sea urchin species suggesting that the Wnt signaling pathway should be further investigated for its role in negligible senescence.

  4. Self-Esteem Development across the Life Span: A Longitudinal Study with a Large Sample from Germany

    Science.gov (United States)

    Orth, Ulrich; Maes, Jürgen; Schmitt, Manfred

    2015-01-01

    The authors examined the development of self-esteem across the life span. Data came from a German longitudinal study with 3 assessments across 4 years of a sample of 2,509 individuals ages 14 to 89 years. The self-esteem measure used showed strong measurement invariance across assessments and birth cohorts. Latent growth curve analyses indicated…

  5. Age at menopause, reproductive life span, and type 2 diabetes risk results from the EPIC-interAct Study

    NARCIS (Netherlands)

    Brand, J.S.; Schouw, van der Y.T.; Onland-Moret, N.; Sharp, S.J.; Feskens, E.J.M.

    2013-01-01

    OBJECTIVEAge at menopause is an important determinant of future health outcomes, but little is known about its relationship with type 2 diabetes. We examined the associations of menopausal age and reproductive life span (menopausal age minus menarcheal age) with diabetes risk.RESEARCH DESIGN AND MET

  6. Sustained Attention Across the Life Span in a Sample of 10,000: Dissociating Ability and Strategy.

    Science.gov (United States)

    Fortenbaugh, Francesca C; DeGutis, Joseph; Germine, Laura; Wilmer, Jeremy B; Grosso, Mallory; Russo, Kathryn; Esterman, Michael

    2015-09-01

    Normal and abnormal differences in sustained visual attention have long been of interest to scientists, educators, and clinicians. Still lacking, however, is a clear understanding of how sustained visual attention varies across the broad sweep of the human life span. In the present study, we filled this gap in two ways. First, using an unprecedentedly large 10,430-person sample, we modeled age-related differences with substantially greater precision than have prior efforts. Second, using the recently developed gradual-onset continuous performance test (gradCPT), we parsed sustained-attention performance over the life span into its ability and strategy components. We found that after the age of 15 years, the strategy and ability trajectories saliently diverge. Strategy becomes monotonically more conservative with age, whereas ability peaks in the early 40s and is followed by a gradual decline in older adults. These observed life-span trajectories for sustained attention are distinct from results of other life-span studies focusing on fluid and crystallized intelligence.

  7. Osteopenia is present at an early age and worsens across the life span in girls and women with Rett syndrome

    Science.gov (United States)

    Girls and women with Rett syndrome (RTT) are at increased risk for osteopenia and skeletal fractures. Our objective was to characterize the natural history of bone mineralization in RTT girls and women across their life span and to identify genetic, nutritional, physical, hormonal, or inflammatory ...

  8. Self-Esteem Development across the Life Span: A Longitudinal Study with a Large Sample from Germany

    Science.gov (United States)

    Orth, Ulrich; Maes, Jürgen; Schmitt, Manfred

    2015-01-01

    The authors examined the development of self-esteem across the life span. Data came from a German longitudinal study with 3 assessments across 4 years of a sample of 2,509 individuals ages 14 to 89 years. The self-esteem measure used showed strong measurement invariance across assessments and birth cohorts. Latent growth curve analyses indicated…

  9. Cinnamomum cassia bark in two herbal formulas increases life span in Caenorhabditis elegans via insulin signaling and stress response pathways.

    Directory of Open Access Journals (Sweden)

    Young-Beob Yu

    Full Text Available BACKGROUND: Proving the efficacy and corresponding mode of action of herbal supplements is a difficult challenge for evidence-based herbal therapy. A major hurdle is the complexity of herbal preparations, many of which combine multiple herbs, particularly when the combination is assumed to be vitally important to the effectiveness of the herbal therapy. This issue may be addressed through the use of contemporary methodology and validated animal models. METHODS AND PRINCIPAL FINDINGS: In this study, two commonly used traditional herbal formulas, Shi Quan Da Bu Tang (SQDB and Huo Luo Xiao Ling Dan (HLXL were evaluated using a survival assay and oxidative stress biomarkers in a well-established C. elegans model of aging. HLXL is an eleven herb formula modified from a top-selling traditional herbal formula for the treatment of arthritic joint pain. SQDB consists of ten herbs often used for fatigue and energy, particularly in the aged. We demonstrate here that SQDB significantly extend life span in a C. elegans model of aging. Among all individual herbs tested, two herbs Cinnamomum cassia bark (Chinese pharmaceutical name: Cinnamomi Cortex, CIN and Panax ginseng root (Chinese pharmaceutical name: Ginseng Radix, GS significantly extended life span in C. elegans. CIN in both SQDB and HLXL formula extended life span via modulation of multiple longevity assurance genes, including genes involved in insulin signaling and stress response pathways. All the life-span-extending herbs (SQDB, CIN and GS also attenuated levels of H2O2 and enhanced small heat shock protein expression. Furthermore, the life span-extending herbs significantly delayed human amyloid beta (Abeta-induced toxicity in transgenic C. elegans expressing human Abeta. CONCLUSION/SIGNIFICANCE: These results validate an invertebrate model for rapid, systematic evaluation of commonly used Chinese herbal formulations and may provide insight for designing future evidence-based herbal therapy(s.

  10. Life span and tissue distribution of 111indium-labeled blood platelets in hypomagnesemic lambs

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.D.; Miller, J.K.; White, P.K.; Ramsey, N.

    1983-05-01

    Circulating platelets may be activated by exposed triple-helical collagen in atherosclerotic lesions in Mg-deficient ruminants. Autologous platelets, labeled in vitro with 111In and determined to be active, were injected into 5 hypomagnesemic and 3 control lambs fed semipurified diets with 100 or 2,000 mg of Mg/kg of feed for 3 months. During the first 68 hours, 111In concentrations were 11 times higher in packed cells than in plasma. Packed-cell 111In increased 60% during the first 2 hours, probably due to initial tissue sequestration and later release of labeled platelets. Thereafter, platelet half-life span averaged 60 and 63 hours for hypomagnesemic and control lambs. After 68 hours, lambs were injected with native vascular collagen fibrils at 500 micrograms/kg of body weight to initiate reversible platelet aggregation. Within 1 minute, 83% of packed-cell 111In disappeared from circulation. Thirty minutes later, the lambs were euthanatized and necropsied and in the lungs, liver, and spleen, 111In averaged 24%, 19%, and 9%, respectively, of 111In injected 68 hours earlier. Organ deposits were not affected by Mg intake, but 111In in the lungs was somewhat lower in 2 lambs injected with inactivated collagen. Pathologic changes induced by reversible platelet aggregation were compatible with right ventricular failure complicated by pulmonary edema, similar to changes in hypomagnesemic lambs that died spontaneously. Platelets in blood exposed to vascular lesions in hypomagnesemic ruminants could be a major mortality risk factor in grass tetany disease.

  11. Derived Trail Making Test indices: demographics and cognitive background variables across the adult life span.

    Science.gov (United States)

    Christidi, Foteini; Kararizou, Evangelia; Triantafyllou, Nikolaos; Anagnostouli, Maria; Zalonis, Ioannis

    2015-01-01

    We examined the contribution of demographics and cognitive background variables (processing speed, visuospatial skill, working memory, and interference control) on derived Trail Making Test (TMT) scores in a large sample of Greek healthy participants. We included 775 participants and administered the TMT (TMT-A and TMT-B) and the Wechsler Intelligence Adult Scale (WAIS). Direct (TMT-A & TMT-B time-to-completion) and derived [difference TMT-(B - A) & ratio TMT-(B/A)] scores were calculated. Demographics (age, age(2), education, and gender) and WAIS Full Intelligence Quotient significantly predicted the direct TMT-A (R(2) = 0.426) and TMT-B (R(2) = 0.593) scores and to a lesser extent, the derived TMT-(B - A) (R(2) = 0.343) and TMT-(B/A) (R(2) = 0.088) scores. In a subsample of 537 healthy participants who also completed the Stroop Neuropsychological Screening Test (SNST), demographics (age and education), WAIS Digit Symbol, Block Design, Arithmetic, and SNST accounted for 44.8% and 59.7% of the variance on TMT-A and TMT-B, and 32.5% and 9.6% of the variance on TMT-(B - A) and TMT-(B/A), respectively. We found minimal influence of Block Design and Arithmetic on TMT-(B - A) and an absence of significant influence of any cognitive variable on TMT-(B/A) score. Concluding, derived TMT scores are suggested as indices to detect impairment in cognitive flexibility across the adult life span, since they minimize the effect of demographics and other cognitive background variables.

  12. Implicit motor sequence learning and working memory performance changes across the adult life span

    Directory of Open Access Journals (Sweden)

    Sarah Nadine Meissner

    2016-04-01

    Full Text Available Although implicit motor sequence learning is rather well understood in young adults, effects of aging on this kind of learning are controversial. There is first evidence that working memory (WM might play a role in implicit motor sequence learning in young adults as well as in adults above the age of 65. However the knowledge about the development of these processes across the adult life span is rather limited. As the average age of our population continues to rise, a better understanding of age-related changes in motor sequence learning and potentially mediating cognitive processes takes on increasing significance. Therefore, we investigated aging effects on implicit motor sequence learning and WM. Sixty adults (18-71 years completed verbal and visuospatial n-back tasks and were trained on a serial reaction time task. Randomly varying trials served as control condition. To further assess consolidation indicated by off-line improvement and reduced susceptibility to interference, reaction times (RTs were determined 1 h after initial learning. Young and older but not middle-aged adults showed motor sequence learning. Nine out of 20 older adults (compared to one young/one middle-aged exhibited some evidence of sequence awareness. After 1 h, young and middle-aged adults showed off-line improvement. However, RT facilitation was not specific to sequence trials. Importantly, susceptibility to interference was reduced in young and older adults indicating the occurrence of consolidation. Although WM performance declined in older participants when load was high, it was not significantly related to sequence learning. The data reveal a decline in motor sequence learning in middle-aged but not in older adults. The use of explicit learning strategies in older adults might account for the latter result.

  13. Missing doses in the life span study of Japanese atomic bomb survivors.

    Science.gov (United States)

    Richardson, David B; Wing, Steve; Cole, Stephen R

    2013-03-15

    The Life Span Study of atomic bomb survivors is an important source of risk estimates used to inform radiation protection and compensation. Interviews with survivors in the 1950s and 1960s provided information needed to estimate radiation doses for survivors proximal to ground zero. Because of a lack of interview or the complexity of shielding, doses are missing for 7,058 of the 68,119 proximal survivors. Recent analyses excluded people with missing doses, and despite the protracted collection of interview information necessary to estimate some survivors' doses, defined start of follow-up as October 1, 1950, for everyone. We describe the prevalence of missing doses and its association with mortality, distance from hypocenter, city, age, and sex. Missing doses were more common among Nagasaki residents than among Hiroshima residents (prevalence ratio = 2.05; 95% confidence interval: 1.96, 2.14), among people who were closer to ground zero than among those who were far from it, among people who were younger at enrollment than among those who were older, and among males than among females (prevalence ratio = 1.22; 95% confidence interval: 1.17, 1.28). Missing dose was associated with all-cancer and leukemia mortality, particularly during the first years of follow-up (all-cancer rate ratio = 2.16, 95% confidence interval: 1.51, 3.08; and leukemia rate ratio = 4.28, 95% confidence interval: 1.72, 10.67). Accounting for missing dose and late entry should reduce bias in estimated dose-mortality associations.

  14. Benefits of multi-modal fusion analysis on a large-scale dataset: life-span patterns of inter-subject variability in cortical morphometry and white matter microstructure.

    Science.gov (United States)

    Groves, Adrian R; Smith, Stephen M; Fjell, Anders M; Tamnes, Christian K; Walhovd, Kristine B; Douaud, Gwenaëlle; Woolrich, Mark W; Westlye, Lars T

    2012-10-15

    Neuroimaging studies have become increasingly multimodal in recent years, with researchers typically acquiring several different types of MRI data and processing them along separate pipelines that provide a set of complementary windows into each subject's brain. However, few attempts have been made to integrate the various modalities in the same analysis. Linked ICA is a robust data fusion model that takes multi-modal data and characterizes inter-subject variability in terms of a set of multi-modal components. This paper examines the types of components found when running Linked ICA on a large magnetic resonance imaging (MRI) morphometric and diffusion tensor imaging (DTI) data set comprising 484 healthy subjects ranging from 8 to 85 years of age. We find several strong global features related to age, sex, and intracranial volume; in particular, one component predicts age to a high accuracy (r=0.95). Most of the remaining components describe spatially localized modes of variability in white or gray matter, with many components including both tissue types. The multimodal components tend to be located in anatomically-related brain areas, suggesting a morphological and possibly functional relationship. The local components show relationships between surface-based cortical thickness and arealization, voxel-based morphometry (VBM), and between three different DTI measures. Further, we report components related to artifacts (e.g. scanner software upgrades) which would be expected in a dataset of this size. Most of the 100 extracted components showed interpretable spatial patterns and were found to be reliable using split-half validation. This work provides novel information about normal inter-subject variability in brain structure, and demonstrates the potential of Linked ICA as a feature-extracting data fusion approach across modalities. This exploratory approach automatically generates models to explain structure in the data, and may prove especially powerful for large

  15. Complex span and n-back measures of working memory: a meta-analysis.

    Science.gov (United States)

    Redick, Thomas S; Lindsey, Dakota R B

    2013-12-01

    Working memory is a construct of primary relevance to many areas of psychology. Two types of tasks have been used to measure working memory, primarily in different research areas: Complex span tasks are commonly used in behavioral studies in the cognitive and individual-differences literature, whereas n-back tasks have been used more frequently in cognitive neuroscience studies investigating the neural underpinnings of working memory. Despite both categories of tasks being labeled as "working memory" measures, previous empirical studies have provided mixed evidence regarding the shared amount of overlapping processes between complex span and n-back tasks. The present meta-analysis showed that the complex span and n-back tasks are weakly correlated, although significant heterogeneity across studies was observed. A follow-up analysis of unpublished data indicated that the sample composition affects the relationship between the complex span and n-back tasks, following the law of diminishing returns. Finally, a separate meta-analysis indicated that the simple span and n-back tasks are correlated to the same extent as are the complex span and n-back tasks. The present findings indicate that the complex span and n-back tasks cannot be used interchangeably as working memory measures in research applications.

  16. FVC deterioration, airway obstruction determination, and life span in Ataxia telangiectasia.

    Science.gov (United States)

    Vilozni, Daphna; Lavie, Moran; Sarouk, Ifat; Bar-Aluma, Bat-El; Dagan, Adi; Ashkenazi, Moshe; Ofek, Miryam; Efrati, Ori

    2015-07-01

    Forced vital capacity (FVC) values decrease with progress of the disease in Ataxia telangiectasia (AT). To study the effect of this process on airway obstruction determination and life span in AT. Clinical data and yearly best spirometry maneuvers were collected retrospectively from 37 AT patients (196 spirometry tests) during 5.4 ± 1.8yrs (initial age 4-21 y). Twelve patients were walking (7 of them had recurrent respiratory system infections); 25 subjects were confined to wheelchair, of them 8 patients were towards end-stage lung disease. Spirometry indices included Forced Vital Capacity (FVC), mid-expiratory-flow (FEF25-75), and tidal volume (VT). We calculated FEF25-75/FVC and VT/FVC ratios. FVC declined from 67 ± 8 while walking to 19 ± 6 %predicted values. FEF25-75 values that were elevated (116 ± 23 %predicted) while walking, decreased to 69 ± 27 %predicted at end-stage where 7 patients responded to bronchodilators. VT/FVC ratio was 0.25 ± 0.06 while walking, increased to 0.35 once on wheelchairs, and further increased to 0.57 ± 0.19 at end-stage disease. FEF25-75/FVC ratio was 2.54 ± 0.70 above normal (∼1.0) increasing to 4.16 ± 0.75 at end stage. A sharp elevation was seen in FEF25-75/FVC ratio when FEV1 was still ∼45 %predicted and 2-years prior to death. Having a low baseline-FVC (60% predicted) artificially raises FEF25-75 values, so FEF25-75 of "mild obstruction" values may indicate severe airway obstruction in AT subjects. VT/FVC and FEF25-75/FVC ratios may therefore assist in revealing higher than normal breathing effort. The results further suggest adding VT/FVC and FEF25-75/FVC ratios to pulmonary function assessments in patients with AT. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. reliability analysis of a two span floor designed according to ...

    African Journals Online (AJOL)

    user

    The Structural analysis and design of the timber floor system was carried out using deterministic approach ... The cell structure of hardwoods is more complex than ..... [12] BS EN -1-1: Eurocode 5: Design of Timber Structures, Part. 1-1.

  18. Effects of shortened host life span on the evolution of parasite life history and virulence in a microbial host-parasite system

    Directory of Open Access Journals (Sweden)

    Koella Jacob C

    2009-03-01

    Full Text Available Abstract Background Ecological factors play an important role in the evolution of parasite exploitation strategies. A common prediction is that, as shorter host life span reduces future opportunities of transmission, parasites compensate with an evolutionary shift towards earlier transmission. They may grow more rapidly within the host, have a shorter latency time and, consequently, be more virulent. Thus, increased extrinsic (i.e., not caused by the parasite host mortality leads to the evolution of more virulent parasites. To test these predictions, we performed a serial transfer experiment, using the protozoan Paramecium caudatum and its bacterial parasite Holospora undulata. We simulated variation in host life span by killing hosts after 11 (early killing or 14 (late killing days post inoculation; after killing, parasite transmission stages were collected and used for a new infection cycle. Results After 13 cycles (≈ 300 generations, parasites from the early-killing treatment were less infectious, but had shorter latency time and higher virulence than those from the late-killing treatment. Overall, shorter latency time was associated with higher parasite loads and thus presumably with more rapid within-host replication. Conclusion The analysis of the means of the two treatments is thus consistent with theory, and suggests that evolution is constrained by trade-offs between virulence, transmission and within-host growth. In contrast, we found little evidence for such trade-offs across parasite selection lines within treatments; thus, to some extent, these traits may evolve independently. This study illustrates how environmental variation (experienced by the host can lead to the evolution of distinct parasite strategies.

  19. Parthenogenetic reproduction of Diaphanosoma celebensis (Crustacea: Cladocera). Effect of algae and algal density on survival, growth, life span and neonate production

    Digital Repository Service at National Institute of Oceanography (India)

    Shrivastava, Y.; Mahambre, G.G.; Achuthankutty, C.T.; Fernandes, Brenda; Goswami, S.C.; Madhupratap, M.

    ) and Tetraselmis gracilis (Kylin), was determined. Growth was faster in the initial stage with all three diets but slowed down in later life. Increased food concentrations resulted in higher neonate production but reduced the life span of females. However, long...

  20. Blowup and life span bounds for a reaction-diffusion equation with a time-dependent generator

    Directory of Open Access Journals (Sweden)

    Aroldo Perez

    2008-01-01

    Full Text Available We consider the nonlinear equation $$ frac{partial}{partial t} u (t = k (t Delta _{alpha }u (t + u^{1+eta } (t,quad u(0,x=lambda varphi (x,; xin mathbb{R} ^{d}, $$ where $Delta _{alpha }:=-(-Delta^{alpha /2}$ denotes the fractional power of the Laplacian; $00$ are constants; $ varphi$ is bounded, continuous, nonnegative function that does not vanish identically; and $k$ is a locally integrable function. We prove that any combination of positive parameters $d,alpha, ho,eta$, obeying $0life span of the solution, and show that the life span satisfies $T_{lambdavarphi}sim lambda^{-alpha eta /(alpha -d ho eta }$ near $lambda=0$.

  1. Acacetin 7-O-α-l-rhamnopyranosyl (1-2) β-D-xylopyranoside Elicits Life-span Extension and Stress Resistance in Caenorhabditis elegans.

    Science.gov (United States)

    Asthana, Jyotsna; Yadav, Deepti; Pant, Aakanksha; Yadav, A K; Gupta, M M; Pandey, Rakesh

    2016-09-01

    The advancements in the field of gerontology have unraveled the signaling pathways that regulate life span, suggesting that it might be feasible to modulate aging. To this end, we isolated a novel phytomolecule Acacetin 7-O-α-l-rhamnopyranosyl (1-2) β-D-xylopyranoside (ARX) from Premna integrifolia and evaluated its antiaging effects in Caenorhabditis elegans The spectral data analysis revealed the occurrence of a new compound ARX. Out of the three tested pharmacological doses of ARX, viz. 5, 25, and 50 µM, the 25-µM dose was able to extend life span in C. elegans by more than 39%. The present study suggests that ARX affects bacterial metabolism, which in turn leads to dietary restriction (DR)-like effects in the worms. The effect of ARX on worms with mutations (mev-1, eat-2, sir-2.1, skn-1, daf-16, and hsf-1) indicates that ARX-mediated life-span extension involves mechanisms associated with DR and maintenance of cellular redox homeostasis. This study is the first time report on longevity-promoting activity of ARX in C. elegans mediated by stress and DR-regulating genes. This novel phytomolecule can contribute in designing therapeutics for managing aging and age-related diseases.

  2. The Development of Memory Efficiency and Value-Directed Remembering across the Life Span: A Cross-Sectional Study of Memory and Selectivity

    Science.gov (United States)

    Castel, Alan D.; Humphreys, Kathryn L.; Lee, Steve S.; Galvan, Adriana; Balota, David A.; McCabe, David P.

    2011-01-01

    Although attentional control and memory change considerably across the life span, no research has examined how the ability to strategically remember important information (i.e., value-directed remembering) changes from childhood to old age. The present study examined this in different age groups across the life span (N = 320, 5-96 years old). A…

  3. The effects of constant and alternating temperatures on the reproductive potential, life span, and life expectancy of Anastrepha fraterculus (Wiedemann (Dipteria: Tephritidae

    Directory of Open Access Journals (Sweden)

    V. V. CARDOSO

    Full Text Available Ovarian development, oviposition, larval eclosion, ornithine decarboxylase (ODC activity, ovarian, testis and ejaculatory apodeme measurements (length, width, and area, and the number of spermatozoa of Anastrepha fraterculus (Wiedemann were analyzed at alternating (20º/6ºC and 20º/13°C and constant (6°C; 25°C temperatures. Life span and life expectancy were also analyzed for both genders. All the results suggest that temperature, especially alternating temperatures, increase not only male and female reproductive potential but also their life span and life expectancy. These changes can be a powerful strategy triggered by A. fraterculus as a means to survive the stressful temperature conditions found in winter in the apple production region in Brazil, enabling this species to increase its population density and cause apple damage when spring begins.

  4. The effects of constant and alternating temperatures on the reproductive potential, life span, and life expectancy of Anastrepha fraterculus (Wiedemann (Dipteria: Tephritidae

    Directory of Open Access Journals (Sweden)

    CARDOSO V. V.

    2002-01-01

    Full Text Available Ovarian development, oviposition, larval eclosion, ornithine decarboxylase (ODC activity, ovarian, testis and ejaculatory apodeme measurements (length, width, and area, and the number of spermatozoa of Anastrepha fraterculus (Wiedemann were analyzed at alternating (20masculine/6masculineC and 20masculine/13degreesC and constant (6degreesC; 25degreesC temperatures. Life span and life expectancy were also analyzed for both genders. All the results suggest that temperature, especially alternating temperatures, increase not only male and female reproductive potential but also their life span and life expectancy. These changes can be a powerful strategy triggered by A. fraterculus as a means to survive the stressful temperature conditions found in winter in the apple production region in Brazil, enabling this species to increase its population density and cause apple damage when spring begins.

  5. Dietary consumption of monosodium L-glutamate induces adaptive response and reduction in the life span of Drosophila melanogaster.

    Science.gov (United States)

    Abolaji, Amos O; Olaiya, Charles O; Oluwadahunsi, Oluwagbenga J; Farombi, Ebenezer O

    2017-04-01

    Adaptive response is the ability of an organism to better counterattack stress-induced damage in response to a number of different cytotoxic agents. Monosodium L-glutamate (MSG), the sodium salt of amino acid glutamate, is commonly used as a food additive. We investigated the effects of MSG on the life span and antioxidant response in Drosophila melanogaster (D. melanogaster). Both genders (1 to 3 days old) of flies were fed with diet containing MSG (0.1, 0.5, and 2.5-g/kg diet) for 5 days to assess selected antioxidant and oxidative stress markers, while flies for longevity were fed for lifetime. Thereafter, the longevity assay, hydrogen peroxide (H2 O2 ), and reactive oxygen and nitrogen species levels were determined. Also, catalase, glutathione S-transferase and acetylcholinesterase activities, and total thiol content were evaluated in the flies. We found that MSG reduced the life span of the flies by up to 23% after continuous exposure. Also, MSG increased reactive oxygen and nitrogen species and H2 O2 generations and total thiol content as well as the activities of catalase and glutathione S-transferase in D. melanogaster (P melanogaster induced adaptive response, but long-term exposure reduced life span of flies. This study may therefore have public health significance in humans, and thus, moderate consumption of MSG is advocated by the authors. Copyright © 2017 John Wiley & Sons, Ltd.

  6. An approach to give prospective life-span of the copper/low-density-polyethylene nanocomposite intrauterine device.

    Science.gov (United States)

    Xia, Xianping; Tang, Ying; Xie, Changsheng; Wang, Yun; Cai, Shuizhou; Zhu, Changhong

    2011-07-01

    As a novel copper-containing intrauterine device (IUD), the prospective life-span of the copper/low-density-polyethylene (Cu/LDPE) nanocomposite IUD is very important for the future clinical use and should be given in advance. Here a novel approach, cupric ions accelerated release in diluted nitric acid solution and cupric ions concentration release in various volume of simulated uterine solution (SUS), is reported to verify the type of cupric ions release model of the cylindrical matrix-type nanocomposite IUD, and to obtain the minimal cupric ions release rate that need to ensure contraceptive efficacy and the thickness of copper particles exhausted layer of the cylindrical matrix-type nanocomposite IUD within two difficult immersion durations in experimental volume of SUS, respectively. Using these results, the prospective life-span of the cylindrical matrix-type nanocomposite IUD can be obtained. For instance, the prospective life-span of the novel γ-shape nanocomposite IUD with 25 wt% of copper nanoparticles and 2 mm of diameter and a total weight of 285 mg can be given in advance and it is about 5 years in the future clinical use.

  7. How Stable Is the Personal Past? Stability of Most Important Autobiographical Memories and Life Narratives Across Eight Years in a Life Span Sample.

    Science.gov (United States)

    Köber, Christin; Habermas, Tilmann

    2017-03-23

    Considering life stories as the most individual layer of personality (McAdams, 2013) implies that life stories, similar to personality traits, exhibit some stability throughout life. Although stability of personality traits has been extensively investigated, only little is known about the stability of life stories. We therefore tested the influence of age, of the proportion of normative age-graded life events, and of global text coherence on the stability of the most important memories and of brief entire life narratives as 2 representations of the life story. We also explored whether normative age-graded life events form more stable parts of life narratives. In a longitudinal life span study covering up to 3 measurements across 8 years and 6 age groups (N = 164) the stability of important memories and of entire life narratives was measured as the percentage of events and narrative segments which were repeated in later tellings. Stability increased between ages 8 and 24, leveling off in middle adulthood. Beyond age, stability of life narratives was also predicted by proportion of normative age-graded life events and by causal-motivational text coherence in younger participants. Memories of normative developmental and social transitional life events were more stable than other memories. Stability of segments of life narratives exceeded the stability of single most important memories. Findings are discussed in terms of cognitive, personality, and narrative psychology and point to research questions in each of these fields. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. Delayed accumulation of intestinal coliform bacteria enhances life span and stress resistance in Caenorhabditis elegans fed respiratory deficient E. coli

    Directory of Open Access Journals (Sweden)

    Gomez Fernando

    2012-12-01

    Full Text Available Abstract Background Studies with the nematode model Caenorhabditis elegans have identified conserved biochemical pathways that act to modulate life span. Life span can also be influenced by the composition of the intestinal microbiome, and C. elegans life span can be dramatically influenced by its diet of Escherichia coli. Although C. elegans is typically fed the standard OP50 strain of E. coli, nematodes fed E. coli strains rendered respiratory deficient, either due to a lack coenzyme Q or the absence of ATP synthase, show significant life span extension. Here we explore the mechanisms accounting for the enhanced nematode life span in response to these diets. Results The intestinal load of E. coli was monitored by determination of worm-associated colony forming units (cfu/worm or coliform counts as a function of age. The presence of GFP-expressing E. coli in the worm intestine was also monitored by fluorescence microscopy. Worms fed the standard OP50 E. coli strain have high cfu and GFP-labeled bacteria in their guts at the L4 larval stage, and show saturated coliform counts by day five of adulthood. In contrast, nematodes fed diets of respiratory deficient E. coli lacking coenzyme Q lived significantly longer and failed to accumulate bacteria within the lumen at early ages. Animals fed bacteria deficient in complex V showed intermediate coliform numbers and were not quite as long-lived. The results indicate that respiratory deficient Q-less E. coli are effectively degraded in the early adult worm, either at the pharynx or within the intestine, and do not accumulate in the intestinal tract until day ten of adulthood. Conclusions The findings of this study suggest that the nematodes fed the respiratory deficient E. coli diet live longer because the delay in bacterial colonization of the gut subjects the worms to less stress compared to worms fed the OP50 E. coli diet. This work suggests that bacterial respiration can act as a virulence factor

  9. Life-Cycle Monitoring of Long-Span PSC Box Girder Bridges through Distributed Sensor Network: Strategies, Methods, and Applications

    Directory of Open Access Journals (Sweden)

    Zheheng Chen

    2015-01-01

    Full Text Available Structural health monitoring (SHM has attracted much attention in recent years, which enables early warnings of structural failure, condition assessments, and rational maintenance/repair strategies. In the context of bridges, many long-span steel bridges in China have been installed with the SHM systems; however, the applications of the SHM in prestressed concrete (PSC bridges are still rather limited. On the other hand, the PSC box girder bridges are extensively used in highway and railway systems and premature damage of these bridges is often reported, resulting in considerable maintenance and/or replacement costs. First, this paper presents a state-of-art review on the SHM of long-span PSC bridges. Monitoring strategies, methods, and previous applications for these bridges are summarized and discussed. In order to well capture the behavior of the bridge during its whole life and to maximize the use of sensors, a life-cycle monitoring strategy is proposed, in which the sensor layout is determined according to requirements for construction monitoring, completion test, and in-service monitoring. A case study is made on a three-span PSC box girder bridge in China. The system configuration, sensor layout, and data communications, and so forth, are presented. The up-to-date monitored structural responses are analyzed and compared with the design values.

  10. Evaluation of platelet thromboxane radioimmunoassay method to measure platelet life-span: Comparison with /sup 111/indium-platelet method

    Energy Technology Data Exchange (ETDEWEB)

    Vallabhajosula, S.; Machac, J.; Badimon, L.; Lipszyc, H.; Goldsmith, S.J.; Fuster, V.

    1985-05-01

    The platelet activation during radiolabeling in vitro with Cr-51 and In-111 may affect the platelet life-span (PLS) in vivo. A new RIA method to measure PLS is being evaluated. Aspirin inhibits platelet thromboxane (TxA/sub 2/) by acetylating cyclooxygenase. The time required for the TxA/sub 2/ levels to return towards control values depends on the rate of new platelets entering circulation and is a measure of PLS. A single dose of aspirin (150mg) was given to 5 normal human subjects. Blood samples were collected for 2 days before aspirin and daily for 10 days. TxA/sub 2/ production in response to endogenous thrombin was studied by allowing 1 ml blood sample to clot at 37/sup 0/C for 90 min. Serum TxB/sub 2/ (stable breakdown product of Tx-A/sub 2/) levels determined by RIA technique. The plot of TxB/sub 2/ levels (% control) against time showed a gradual increase. The PLS calculated by linear regression analysis assuming a 2-day lag period before cyclooxygenase recovery is 9.7 +- 2.37. In the same 5 subjects, platelets from a 50ml blood sample were labeled with /sup 111/In-tropolone in 2 ml autologous plasma. Starting at 1 hr after injection of labeled platelets, 10 blood samples were obtained over a 8 day period. The PLS calculated based on a linear regression analysis is 10.2 +. 1.4. The PLS measured from the rate of platelet disappearance from circulation and the rate of platelet regeneration into circulation are quite comparable in normal subjects. TxA/sub 2/ regeneration RIA may provide a method to measure PLS without administering radioactivity to patient.

  11. Longevity for free? Increased reproduction with limited trade-offs in Drosophila melanogaster selected for increased life span.

    Science.gov (United States)

    Wit, Janneke; Sarup, Pernille; Lupsa, Nikolett; Malte, Hans; Frydenberg, Jane; Loeschcke, Volker

    2013-03-01

    Selection for increased life span in Drosophila melanogaster has been shown to correlate with decreased early fecundity and increased fecundity later in life. This phenomenon has been ascribed to the existence of trade-offs in which limited resources can be invested in either somatic maintenance or reproduction. In our longevity selection lines, we did not find such a trade-off. Rather, we find that females have similar or higher fecundity throughout life compared to non-selected controls. To determine whether increased longevity affects responses in other traits, we looked at several stress resistance traits (chill coma recovery, heat knockdown, desiccation and starvation), geotactic behaviour, egg-to-adult viability, body size, developmental time as well as metabolic rate. Longevity selected flies were more starvation resistant. However, in females longevity and fecundity were not negatively correlated with the other traits assayed. Males from longevity selected lines were slower at recovering from a chill induced coma and resting metabolic rate increased with age, but did not correlate with life span. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. 复杂悬跨条件下的管线涡激振动分析%VIV analysis of pipelines under complex span conditions

    Institute of Scientific and Technical Information of China (English)

    James WANG; F. Steven WANG; Gang DUAN; Paul JUKES

    2009-01-01

    Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span sections, but also generates vortex induced vibration (VIV), which can lead to fatigue issues. The phenomenon, if not predicted and controlled properly, will negatively affect pipeline integrity, leading to expensive remediation and intervention work. Span analysis can be complicated by: long span lengths, a large number of spans caused by a rough seabed, and multi-span interactions. In addition, the complexity can be more onerous and challenging when soil uncertainty, concrete degradation and unknown residual lay tension are considered in the analysis. This paper describes the latest developments and a .state-of-the-art. finite element analysis program that has been developed to simulate the span response of a flowline under complex boundary and loading conditions. Both VIV and direct wave loading are captured in the analysis and the results are sequentially used for the ultimate limit state (ULS) check and fatigue life calculation.

  13. Caloric restriction, the traditional Okinawan diet, and healthy aging: the diet of the world's longest-lived people and its potential impact on morbidity and life span.

    Science.gov (United States)

    Willcox, Bradley J; Willcox, D Craig; Todoriki, Hidemi; Fujiyoshi, Akira; Yano, Katsuhiko; He, Qimei; Curb, J David; Suzuki, Makoto

    2007-10-01

    Long-term caloric restriction (CR) is a robust means of reducing age-related diseases and extending life span in multiple species, but the effects in humans are unknown. The low caloric intake, long life expectancy, and the high prevalence of centenarians in Okinawa have been used as an argument to support the CR hypothesis in humans. However, no long-term, epidemiologic analysis has been conducted on traditional dietary patterns, energy balance, and potential CR phenotypes for the specific cohort of Okinawans who are purported to have had a calorically restricted diet. Nor has this cohort's subsequent mortality experience been rigorously studied. Therefore, we investigated six decades of archived population data on the elderly cohort of Okinawans (aged 65-plus) for evidence of CR. Analyses included traditional diet composition, energy intake, energy expenditure, anthropometry, plasma DHEA, mortality from age-related diseases, and current survival patterns. Findings include low caloric intake and negative energy balance at younger ages, little weight gain with age, life-long low BMI, relatively high plasma DHEA levels at older ages, low risk for mortality from age-related diseases, and survival patterns consistent with extended mean and maximum life span. This study lends epidemiologic support for phenotypic benefits of CR in humans and is consistent with the well-known literature on animals with regard to CR phenotypes and healthy aging.

  14. Hard-Rock Stability Analysis for Span Design in Entry-Type Excavations with Learning Classifiers.

    Science.gov (United States)

    García-Gonzalo, Esperanza; Fernández-Muñiz, Zulima; García Nieto, Paulino José; Bernardo Sánchez, Antonio; Menéndez Fernández, Marta

    2016-06-29

    The mining industry relies heavily on empirical analysis for design and prediction. An empirical design method, called the critical span graph, was developed specifically for rock stability analysis in entry-type excavations, based on an extensive case-history database of cut and fill mining in Canada. This empirical span design chart plots the critical span against rock mass rating for the observed case histories and has been accepted by many mining operations for the initial span design of cut and fill stopes. Different types of analysis have been used to classify the observed cases into stable, potentially unstable and unstable groups. The main purpose of this paper is to present a new method for defining rock stability areas of the critical span graph, which applies machine learning classifiers (support vector machine and extreme learning machine). The results show a reasonable correlation with previous guidelines. These machine learning methods are good tools for developing empirical methods, since they make no assumptions about the regression function. With this software, it is easy to add new field observations to a previous database, improving prediction output with the addition of data that consider the local conditions for each mine.

  15. 论寿命学:1.成熟与成就%On the Life Span:1.Maturity and Achievements

    Institute of Scientific and Technical Information of China (English)

    李文彬; 张炳烈; 崔旭; 黄福南; 蔡竖平

    2001-01-01

    Based on the progress of life span study,it is concluded that a novel discipline called “life span science” is established.This conclusion comes out of following view points:1.The big succeses are raised in area of life span study,such as the genetic regulation of longevity as well as the promotive role of reactive oxygen species on aging;2.Theory about the determinant of life span derived from the evolutional and experimental study is accepted by more and more researchers;3.The principle and course of life span study is developed,especially,the artificial evolution model of life span is the main measure to disclose the mystery of longevity.The life span science will provide a theoritical tool to combat for longevity.%从寿命研究的历史轨迹和令人瞩目的成就着重论述了寿命学已经发展成熟,成为独立的学术体系并进一步从寿命进化的历程中探讨寿命形成的原因,指出氧的决定性作用,为提高生命质量,延长寿命提供科学依据。

  16. Cluster-span threshold: An unbiased threshold for binarising weighted complete networks in functional connectivity analysis.

    Science.gov (United States)

    Smith, Keith; Azami, Hamed; Parra, Mario A; Starr, John M; Escudero, Javier

    2015-08-01

    We propose a new unbiased threshold for network analysis named the Cluster-Span Threshold (CST). This is based on the clustering coefficient, C, following logic that a balance of `clustering' to `spanning' triples results in a useful topology for network analysis and that the product of complementing properties has a unique value only when perfectly balanced. We threshold networks by fixing C at this balanced value, rather than fixing connection density at an arbitrary value, as has been the trend. We compare results from an electroencephalogram data set of volunteers performing visual short term memory tasks of the CST alongside other thresholds, including maximum spanning trees. We find that the CST holds as a sensitive threshold for distinguishing differences in the functional connectivity between tasks. This provides a sensitive and objective method for setting a threshold on weighted complete networks which may prove influential on the future of functional connectivity research.

  17. Analysis of Deflection Problems of Large-span Continuous Rigid Frame Bridge and Prevention Measures

    Directory of Open Access Journals (Sweden)

    Chen Dong

    2015-01-01

    Full Text Available The large-span continuous rigid frame bridge is a kind of common structural form in long-span bridges of our country, but one of the main diseases of these bridges is the excessive deflection in the mid-span, which seriously affects the safety of the structure. This paper makes a comprehensive analysis for the causes of the excessive deflection, and lists the commonly-used control measures in engineering. Simultaneously, new improvement measures and the comparative analysis of before-and-after improvements are put forward on this basis. However, these measures can be used to inhibit deflection in a certain extent, but cannot avoid the occurrence of deflection completely.

  18. Protein methionine content and MDA-lysine adducts are inversely related to maximum life span in the heart of mammals.

    Science.gov (United States)

    Ruiz, Maria Cristina; Ayala, Victoria; Portero-Otín, Manel; Requena, Jesús R; Barja, Gustavo; Pamplona, Reinald

    2005-10-01

    Aging affects all organisms and its basic mechanisms are expected to be conserved across species. Oxidation of proteins has been proposed to be one of the basic mechanisms linking oxygen radicals with the basic aging process. If oxidative damage to proteins is involved in aging, long-lived animals (which age slowly) should show lower levels of markers of this kind of damage than short-lived ones. However, this possibility has not been investigated yet. In this study, steady-state levels of markers of different kinds of protein damage--oxidation (glutamic and aminoadipic semialdehydes), mixed glyco- and lipoxidation (carboxymethyl- and carboxyethyllysine), lipoxidation (malondialdehydelysine) and amino acid composition--were measured in the heart of eight mammalian species ranging in maximum life span (MLSP) from 3.5 to 46 years. Oxidation markers were directly correlated with MLSP across species. Mixed glyco- and lipoxidation markers did not correlate with MLSP. However, the lipoxidation marker malondialdehydelysine was inversely correlated with MLSP (r2=0.85; P<0.001). The amino acid compositional analysis revealed that methionine is the only amino acid strongly correlated MLSP and that such correlation is negative (r2=0.93; P<0.001). This trait may contribute to lower steady-state levels of oxidized methionine residues in cellular proteins. These results reinforce the notion that high longevity in homeothermic vertebrates is achieved in part by constitutively decreasing the sensitivity of both tissue proteins and lipids to oxidative damage. This is obtained by modifying the constituent structural components of proteins and lipids, selecting those less sensitive to oxidative modifications.

  19. Effect of Temperature on Imago Life Span, Fecundity and Reproduction Rate of Greenhouse Whitefly (T. vaporariorum W.

    Directory of Open Access Journals (Sweden)

    Pantelija Perić

    2006-01-01

    Full Text Available Imago life span, fecundity and survival rate of the different developmental stages and average abundance of female offspring of greenhouse whitefly (Trialeurodes vaporariorum were studied at three constant (18, 22 and 27°C and one alternating (18/7°C temperature.Temperature highs are inversely proportionate to imago life span. Temperature increase from 18/7°C to 27°C decreased the whitefly life span 3.3-fold. Under 18°C and 22°C, whitefly laid eggs most abundantly (147 and 126, respectively, while fecundity decreased under lower and higher temperatures. Half the offspring of the investigated whitefly laboratory strain (49.5% were males, which resulted in lower values of reproduction and growth rates of the whitefly strain.Optimum development of greenhouse whitefly was achieved at 18°C, which is evident from a maximum number of eggs laid and highest average number of potential and actual female offspring (68.2 and 58.3, respectively, compared to the other investigated temperatures.The consequence of a 50.8-day long true generation time is evident from the low values of growth capacity (0.074 and intrinsic rate of increase (0.080. With temperature increasing to 22°C and 27°C, the period of whitefly oviposition showed a tendency to decrease further on. Higher temperatures reduced the total abundance of eggs laid and, consequently, the abundance of potential and actual female offspring, but increased growth rate.

  20. Bax-induced apoptosis shortens the life span of DNA repair defect Ku70-knockout mice by inducing emphysema.

    Science.gov (United States)

    Matsuyama, Shigemi; Palmer, James; Bates, Adam; Poventud-Fuentes, Izmarie; Wong, Kelvin; Ngo, Justine; Matsuyama, Mieko

    2016-06-01

    Cells with DNA damage undergo apoptosis or cellular senescence if the damage cannot be repaired. Recent studies highlight that cellular senescence plays a major role in aging. However, age-associated diseases, including emphysema and neurodegenerative disorders, are caused by apoptosis of lung alveolar epithelial cells and neurons, respectively. Therefore, enhanced apoptosis also promotes aging and shortens the life span depending on the cell type. Recently, we reported that ku70(-) (/) (-)bax(-) (/) (-) and ku70(-) (/) (-)bax(+/) (-) mice showed significantly extended life span in comparison with ku70(-) (/) (-)bax(+/+) mice. Ku70 is essential for non-homologous end joining pathway for DNA double strand break repair, and Bax plays an important role in apoptosis. Our study suggests that Bax-induced apoptosis has a significant impact on shortening the life span of ku70(-) (/) (-) mice, which are defective in one of DNA repair pathways. The lung alveolar space gradually enlarges during aging, both in mouse and human, and this age-dependent change results in the decrease of respiration capacity during aging that can lead to emphysema in more severe cases. We found that emphysema occurred in ku70(-) (/) (-) mice at the age of three-months old, and that Bax deficiency was able to suppress it. These results suggest that Bax-mediated apoptosis induces emphysema in ku70(-) (/) (-) mice. We also found that the number of cells, including bronchiolar epithelial cells and type 2 alveolar epithelial cells, shows a higher DNA double strand break damage response in ku70 KO mouse lung than in wild type. Recent studies suggest that non-homologous end joining activity decreases with increased age in mouse and rat model. Together, we hypothesize that the decline of Ku70-dependent DNA repair activity in lung alveolar epithelial cells is one of the causes of age-dependent decline of lung function resulting from excess Bax-mediated apoptosis of lung alveolar epithelial cells (and their

  1. Hour glass half full or half empty? Future time perspective and preoccupation with negative events across the life span.

    Science.gov (United States)

    Strough, JoNell; Bruine de Bruin, Wändi; Parker, Andrew M; Lemaster, Philip; Pichayayothin, Nipat; Delaney, Rebecca

    2016-09-01

    According to socioemotional selectivity theory, older adults' emotional well-being stems from having a limited future time perspective that motivates them to maximize well-being in the "here and now." Presumably, then, older adults' time horizons are associated with emotional competencies that boost positive affect and dampen negative affect, but little research has addressed this. Using a U.S. adult life-span sample (N = 3,933; 18-93 years), we found that a 2-factor model of future time perspective (future opportunities; limited time) fit the data better than a 1-factor model. Through middle age, people perceived the life-span hourglass as half full-they focused more on future opportunities than limited time. Around Age 60, the balance changed to increasingly perceiving the life-span hourglass as half empty-they focused less on future opportunities and more on limited time, even after accounting for perceived health, self-reported decision-making ability, and retirement status. At all ages, women's time horizons focused more on future opportunities compared with men's, and men's focused more on limited time. Focusing on future opportunities was associated with reporting less preoccupation with negative events, whereas focusing on limited time was associated with reporting more preoccupation. Older adults reported less preoccupation with negative events, and this association was stronger after controlling for their perceptions of limited time and fewer future opportunities, suggesting that other pathways may explain older adults' reports of their ability to disengage from negative events. Insights gained and questions raised by measuring future time perspective as 2 dimensions are discussed. (PsycINFO Database Record

  2. Genetic manipulation of longevity-related genes as a tool to regulate yeast life span and metabolite production during winemaking

    Directory of Open Access Journals (Sweden)

    Orozco Helena

    2013-01-01

    Full Text Available Abstract Background Yeast viability and vitality are essential for different industrial processes where the yeast Saccharomyces cerevisiae is used as a biotechnological tool. Therefore, the decline of yeast biological functions during aging may compromise their successful biotechnological use. Life span is controlled by a variety of molecular mechanisms, many of which are connected to stress tolerance and genomic stability, although the metabolic status of a cell has proven a main factor affecting its longevity. Acetic acid and ethanol accumulation shorten chronological life span (CLS, while glycerol extends it. Results Different age-related gene classes have been modified by deletion or overexpression to test their role in longevity and metabolism. Overexpression of histone deacetylase SIR2 extends CLS and reduces acetate production, while overexpression of SIR2 homolog HST3 shortens CLS, increases the ethanol level, and reduces acetic acid production. HST3 overexpression also enhances ethanol tolerance. Increasing tolerance to oxidative stress by superoxide dismutase SOD2 overexpression has only a moderate positive effect on CLS. CLS during grape juice fermentation has also been studied for mutants on several mRNA binding proteins that are regulators of gene expression at the posttranscriptional level; we found that NGR1 and UTH4 deletions decrease CLS, while PUF3 and PUB1 deletions increase it. Besides, the pub1Δ mutation increases glycerol production and blocks stress granule formation during grape juice fermentation. Surprisingly, factors relating to apoptosis, such as caspase Yca1 or apoptosis-inducing factor Aif1, play a positive role in yeast longevity during winemaking as their deletions shorten CLS. Conclusions Manipulation of regulators of gene expression at both transcriptional (i.e., sirtuins and posttranscriptional (i.e., mRNA binding protein Pub1 levels allows to modulate yeast life span during its biotechnological use. Due to

  3. Alteration of Drosophila life span using conditional, tissue-specific expression of transgenes triggered by doxycyline or RU486/Mifepristone.

    Science.gov (United States)

    Ford, Daniel; Hoe, Nicholas; Landis, Gary N; Tozer, Kevin; Luu, Allan; Bhole, Deepak; Badrinath, Ananth; Tower, John

    2007-06-01

    The conditional systems Tet-on and Geneswitch were compared and optimized for the tissue-specific expression of transgenes and manipulation of life span in adult Drosophila. Two versions of Tet-on system reverse-tetracycline-Trans-Activator (rtTA) were compared: the original rtTA, and rtTAM2-alt containing mutations designed to optimize regulation and expression. The rtTAM2-alt version gave less leaky expression of target constructs in the absence of doxycyline, however the absolute level of expression that could be achieved was less than that produced by rtTA, in contrast to a previous report. Existing UAS-rtTAM2-alt insertions were re-balanced, and combined with several tissue-general and tissue-specific GAL4 driver lines to yield tissue-specific, doxycyline-inducible transgene expression over three orders of magnitude. The Geneswitch (GS) system also had low background, but the absolute level of expression was low relative to Tet-on. Consequently, actin5C-GS multi-insert chromosomes were generated and higher-level expression was achieved without increased background. Moderate level over-expression of MnSOD has beneficial effects on life span. Here high-level over-expression of MnSOD was found to have toxic effects. In contrast, motor-neuron-specific over-expression of MnSOD had no detectable effect on life span. The results suggest that motor-neuron tissue is not the essential tissue for either MnSOD induced longevity or toxicity in adult males.

  4. Alteration of Drosophila life span using conditional, tissue-specific expression of transgenes triggered by doxycycline or RU486/Mifepristone

    OpenAIRE

    Ford, Daniel; Hoe, Nicholas; Landis, Gary N.; Tozer, Kevin; Luu, Allan; Bhole, Deepak; Badrinath, Ananth; Tower, John

    2007-01-01

    The conditional systems Tet-on and Geneswitch were compared and optimized for the tissue-specific expression of transgenes and manipulation of life span in adult Drosophila. Two versions of Tet-on system reverse-tetracycline-Trans-Activator (rtTA) were compared: the original rtTA, and rtTAM2-alt containing mutations designed to optimize regulation and expression. The rtTAM2-alt version gave less leaky expression of target constructs in the absence of doxycycline, however the absolute level of...

  5. Social relationships and physiological determinants of longevity across the human life span.

    Science.gov (United States)

    Yang, Yang Claire; Boen, Courtney; Gerken, Karen; Li, Ting; Schorpp, Kristen; Harris, Kathleen Mullan

    2016-01-19

    Two decades of research indicate causal associations between social relationships and mortality, but important questions remain as to how social relationships affect health, when effects emerge, and how long they last. Drawing on data from four nationally representative longitudinal samples of the US population, we implemented an innovative life course design to assess the prospective association of both structural and functional dimensions of social relationships (social integration, social support, and social strain) with objectively measured biomarkers of physical health (C-reactive protein, systolic and diastolic blood pressure, waist circumference, and body mass index) within each life stage, including adolescence and young, middle, and late adulthood, and compare such associations across life stages. We found that a higher degree of social integration was associated with lower risk of physiological dysregulation in a dose-response manner in both early and later life. Conversely, lack of social connections was associated with vastly elevated risk in specific life stages. For example, social isolation increased the risk of inflammation by the same magnitude as physical inactivity in adolescence, and the effect of social isolation on hypertension exceeded that of clinical risk factors such as diabetes in old age. Analyses of multiple dimensions of social relationships within multiple samples across the life course produced consistent and robust associations with health. Physiological impacts of structural and functional dimensions of social relationships emerge uniquely in adolescence and midlife and persist into old age.

  6. Revised analysis of the (1+1) EA for the minimum spanning tree problem

    DEFF Research Database (Denmark)

    Witt, Carsten

    2014-01-01

    We revisit the classical analysis of the (1+1) EA for the minimum spanning tree problem in the case that nothing is known about the weights of the underlying graph. Here the original upper bound on the expected running time by Neumann and Wegener [Theor. Comput. Sci. 378(1), 32-40, 2007], which...

  7. Nutrition through the life span. Part 3: adults aged 65 years and over.

    Science.gov (United States)

    Shepherd, Alison

    The UK has an ageing population, but this is not being matched by a similar increase in healthy life expectancy. The greatest challenge in the 21st century will be to improve the quality of life as ageing occurs. Health is the most important prerequisite for people to enjoy life in their older years (Brundtland, 1988). Diet is one factor that is believed to play a key role in the prevention and treatment of chronic diseases associated with ageing. The third and final part of this series addressing the concept of nutrition through the lifespan seeks to educate health-care professionals as to what constitutes a healthy diet for the elderly population, and gives practical guidance as to how to try and prevent the ever-growing problem of malnutrition within this age group. It is suggested that when the older adult is hospitalized their risk of malnutrition increases. Therefore, some guidance for the use of oral nutritional supplements in this population is given. Good nutrition and physical exercise are essential for healthy ageing from both a physical and psychological perspective (NICE, 2008). Therefore a multidisciplinary life course approach to ageing is vital to minimizing its complications for quality of life and subsequent public health (Denny, 2008).

  8. Stability Analysis of Long-Span Continuous Rigid Frame Bridge with Thin-Wall Pier

    Institute of Scientific and Technical Information of China (English)

    HE Bo; SHI Ya-nan; ZHU Hong-ping; GUO Wen-zeng; CHEN Yong

    2008-01-01

    During cantilever cast in construction of high-pier and large-span continuous rigid frame bridges, structural stability in the longest cantilevered stage is very important. Based on a practical design case of a large-span continuous rigid frame bridge in Wuhan, the longest span stability coefficient is calculated with linear-buckling and nonlinear-buckling methods, respectively. The influences of both geometrical nonlinearity and the dual nonlinearity of material and geometry are considered. Numerical results indicate that the nonlinear solution is necessary to stability analysis because linear buckling loads axe much higher than those of nonlinear buckling. Thus, the edge fiber yield criterion is more convenient and faster than ultimate loading criterion when estimating nonlinear stability of structure, and can be used easily in the initial engineering design.

  9. The specificity of childhood adversities and negative life events across the life span to anxiety and depressive disorders

    NARCIS (Netherlands)

    Spinhoven, Philip; Elzinga, Bernet M.; Hovens, Jacqueline G. F. M.; Roelofs, Karin; Zitman, Frans G.; van Oppen, Patricia; Penninx, Brenda W. J. H.

    2010-01-01

    Background: Although several studies have shown that life adversities play an important role in the etiology and maintenance of both depressive and anxiety disorders, little is known about the relative specificity of several types of life adversities to different forms of depressive and anxiety diso

  10. Metabolic Features Across the Female Life Span in Women with PCOS.

    Science.gov (United States)

    Sir-Petermann, Teresa; Echiburú, Bárbara; Crisosto, Nicolás; Maliqueo, Manuel; Bravo, Francisco Pérez

    2016-01-01

    Polycystic ovary syndrome (PCOS) is a highly prevalent endocrine metabolic disorder and is presently considered a family pathology. It is associated with obesity, insulin resistance and metabolic syndrome. Racial, ethnic and environmental factors may be important in determining the clinical manifestations of this syndrome. Polycystic ovary syndrome is an exclusion diagnosis and, therefore, should be distinguished from the physiological changes typical for the age and from other hyperandrogenic disorders. Early diagnosis is important since this syndrome is associated with reproductive, oncologic and metabolic risks. Interestingly, the clinical features of this disorder may change throughout the lifespan of a PCOS woman, starting from adolescence to postmenopausal age. During the first decades of life the main features are in the reproductive area, while later in life metabolic abnormalities are more evident. While the assessment of insulin resistance is not part of the diagnosis of PCOS, it has been demonstrated that this metabolic component appears early in life and persists over time. Moreover during puberty and pregnancy, insulin resistance is exacerbated. Pregnancy represents an important stage, as the offspring of these patients may be reprogrammed and inherit some of the metabolic and reproductive features of their mothers. In the present review, we will focus on several metabolic aspects of the PCOS condition at different stages of life in a Chilean population.

  11. Bile Acid Look-Alike Controls Life Span in C. elegans

    NARCIS (Netherlands)

    Groen, Albert K.; Kuipers, Folkert

    2013-01-01

    Extensive transcriptional networks maintain sterol homeostasis across species, underscoring the importance of sterol balance for healthy life. Magner et al. (2013) now show that, in C. elegans, the nuclear receptor NHR-8 is key in regulation of cholesterol balance and production of dafachronic acid,

  12. Cell death, cell proliferation, and estimates of hair cell life spans in the vestibular organs of chicks.

    Science.gov (United States)

    Kil, J; Warchol, M E; Corwin, J T

    1997-12-01

    We have examined the level of on-going cell death in the chick vestibular epithelia using the TUNEL method and compared this to the rate of on-going cell proliferation. Utricles contained 22.6 +/- 6.8 TUNEL-labeled cells (mean +/- s.e.m.) while saccules contained 15.1 +/- 4.0, with approximately 90% being labeled hair cells. In separate experiments, chicks were given a single injection of BrdU and killed 2 h later. Utricles contained 116.9 +/- 6.5 BrdU-labeled cells (mean +/- s.e.m.) and saccules contained 41.0 +/- 2.2. After 24 h in culture, utricles treated with 1 mM neomycin contained 115.5 +/- 38.9 TUNEL-labeled cells, an increase of 270% over controls. After 48 h, neomycin-treated saccules contained 40.9 +/- 7.8, an increase of 152% over controls. The majority of labeled cells were in the hair cell layer. Thus, neomycin exposure results in an apoptotic death of hair cells. The in vivo data measured here were used to estimate that the average life span of utricular hair cells in young chickens is approximately 20 days, in sharp contrast to the life spans assumed for hair cells in humans.

  13. Assimilation of endogenous nicotinamide riboside is essential for calorie restriction-mediated life span extension in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lu, Shu-Ping; Kato, Michiko; Lin, Su-Ju

    2009-06-19

    NAD(+) (nicotinamide adenine dinucleotide) is an essential cofactor involved in various biological processes including calorie restriction-mediated life span extension. Administration of nicotinamide riboside (NmR) has been shown to ameliorate deficiencies related to aberrant NAD(+) metabolism in both yeast and mammalian cells. However, the biological role of endogenous NmR remains unclear. Here we demonstrate that salvaging endogenous NmR is an integral part of NAD(+) metabolism. A balanced NmR salvage cycle is essential for calorie restriction-induced life span extension and stress resistance in yeast. Our results also suggest that partitioning of the pyridine nucleotide flux between the classical salvage cycle and the NmR salvage branch might be modulated by the NAD(+)-dependent Sir2 deacetylase. Furthermore, two novel deamidation steps leading to nicotinic acid mononucleotide and nicotinic acid riboside production are also uncovered that further underscore the complexity and flexibility of NAD(+) metabolism. In addition, utilization of extracellular nicotinamide mononucleotide requires prior conversion to NmR mediated by a periplasmic phosphatase Pho5. Conversion to NmR may thus represent a strategy for the transport and assimilation of large nonpermeable NAD(+) precursors. Together, our studies provide a molecular basis for how NAD(+) homeostasis factors confer metabolic flexibility.

  14. Chronological and replicative life-span extension in Saccharomyces cerevisiae by increased dosage of alcohol dehydrogenase 1.

    Science.gov (United States)

    Reverter-Branchat, Gemma; Cabiscol, Elisa; Tamarit, Jordi; Sorolla, M Alba; Angeles de la Torre, M; Ros, Joaquim

    2007-11-01

    Alcohol dehydrogenase 1 (Adh1)p catalyses the conversion of acetaldehyde to ethanol, regenerating NAD+. In Saccharomyces cerevisiae, Adh1p is oxidatively modified during ageing and, consequently, its activity becomes reduced. To analyse whether maintaining this activity is advantageous for the cell, a yeast strain with an extra copy of the ADH1 gene (2xADH1) was constructed, and the effects on chronological and replicative ageing were analysed. The strain showed increased survival in stationary phase (chronological ageing) due to induction of antioxidant enzymes such as catalase and superoxide dismutases. In addition, 2xADH1 cells displayed an increased activity of silent information regulator 2 (Sir2)p, an NAD+-dependent histone deacetylase, due to a higher NAD+/NADH ratio. As a consequence, a 30% extension in replicative life span was observed. Taken together, these results suggest that the maintenance of enzymes that participate in NAD+/NADH balancing is important to chronological and replicative life-span parameters.

  15. Bmi-1 extends the life span of normal human oral keratinocytes by inhibiting the TGF-{beta} signaling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Reuben H., E-mail: rkim@dentistry.ucla.edu [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); Lieberman, Mark B.; Lee, Rachel [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); Shin, Ki-Hyuk [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); Mehrazarin, Shebli; Oh, Ju-Eun [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); Park, No-Hee [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Kang, Mo K., E-mail: mkang@dentistry.ucla.edu [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States)

    2010-10-01

    We previously demonstrated that Bmi-1 extended the in vitro life span of normal human oral keratinocytes (NHOK). We now report that the prolonged life span of NHOK by Bmi-1 is, in part, due to inhibition of the TGF-{beta} signaling pathway. Serial subculture of NHOK resulted in replicative senescence and terminal differentiation and activation of TGF-{beta} signaling pathway. This was accompanied with enhanced intracellular and secreted TGF-{beta}1 levels, phosphorylation of Smad2/3, and increased expression of p15{sup INK4B} and p57{sup KIP2}. An ectopic expression of Bmi-1 in NHOK (HOK/Bmi-1) decreased the level of intracellular and secreted TGF-{beta}1 induced dephosphorylation of Smad2/3, and diminished the level of p15{sup INK4B} and p57{sup KIP2}. Moreover, Bmi-1 expression led to the inhibition of TGF-{beta}-responsive promoter activity in a dose-specific manner. Knockdown of Bmi-1 in rapidly proliferating HOK/Bmi-1 and cancer cells increased the level of phosphorylated Smad2/3, p15{sup INK4B}, and p57{sup KIP2}. In addition, an exposure of senescent NHOK to TGF-{beta} receptor I kinase inhibitor or anti-TGF-{beta} antibody resulted in enhanced replicative potential of cells. Taken together, these data suggest that Bmi-1 suppresses senescence of cells by inhibiting the TGF-{beta} signaling pathway in NHOK.

  16. Lifelong susceptibility to acoustic trauma: Changing patterns of chochlear damage over the life span of the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Henry, K.R.

    1983-01-01

    Age-related differences in susceptibility to noise-induced threshold shift (NITS) were examined over the entire life span of the CBA/J mouse. Mice of varying ages were given a single 5-min exposure to a 124-dB octave-band (12-24 kHz) noise. Susceptibility began at 15-16 days postpartum and increased rapidly until approximately 20 days of age. During this phase, NITS (as measured by increased action potential threshold) was greatest at 16 kHz. Overall susceptibility was consistently high from 20 to 90 days. During this phase, NITS became most severe at 32 kHz. From 120 days until beyond the end of its acturarial life span (527 days), NITS no longer occured at 2-16 kHz, but the 64-kHz response retained its susceptibility to acoustic trauma. Mice at 20 and 60 days of age showed the same pattern of decreasing susceptibility as the intensity of the noise exposure was reduced to 114 and 104 dB, indicating that the absence of a tightly restricted critical period is not peculiar to a particular sound pressure level.

  17. Mechanisms of age-related decline in memory search across the adult life span.

    Science.gov (United States)

    Hills, Thomas T; Mata, Rui; Wilke, Andreas; Samanez-Larkin, Gregory R

    2013-12-01

    Three alternative mechanisms for age-related decline in memory search have been proposed, which result from either reduced processing speed (global slowing hypothesis), overpersistence on categories (cluster-switching hypothesis), or the inability to maintain focus on local cues related to a decline in working memory (cue-maintenance hypothesis). We investigated these 3 hypotheses by formally modeling the semantic recall patterns of 185 adults between 27 to 99 years of age in the animal fluency task (Thurstone, 1938). The results indicate that people switch between global frequency-based retrieval cues and local item-based retrieval cues to navigate their semantic memory. Contrary to the global slowing hypothesis that predicts no qualitative differences in dynamic search processes and the cluster-switching hypothesis that predicts reduced switching between retrieval cues, the results indicate that as people age, they tend to switch more often between local and global cues per item recalled, supporting the cue-maintenance hypothesis. Additional support for the cue-maintenance hypothesis is provided by a negative correlation between switching and digit span scores and between switching and total items recalled, which suggests that cognitive control may be involved in cue maintenance and the effective search of memory. Overall, the results are consistent with age-related decline in memory search being a consequence of reduced cognitive control, consistent with models suggesting that working memory is related to goal perseveration and the ability to inhibit distracting information.

  18. Visualizing Life Zone Boundary Sensitivities Across Climate Models and Temporal Spans

    Energy Technology Data Exchange (ETDEWEB)

    Sisneros, Roberto R [ORNL; Huang, Jian [University of Tennessee, Knoxville (UTK); Ostrouchov, George [ORNL; Hoffman, Forrest M [ORNL

    2011-01-01

    Life zones are a convenient and quantifiable method for delineating areas with similar plant and animal communities based on bioclimatic conditions. Such ecoregionalization techniques have proved useful for defining habitats and for studying how these habitats may shift due to environmental change. The ecological impacts of climate change are of particular interest. Here we show that visualizations of the geographic projection of life zones may be applied to the investigation of potential ecological impacts of climate change using the results of global climate model simulations. Using a multi-factor classification scheme, we show how life zones change over time based on quantitative model results into the next century. Using two straightforward metrics, we identify regions of high sensitivity to climate changes from two global climate simulations under two different greenhouse gas emissions scenarios. Finally, we identify how preferred human habitats may shift under these scenarios. We apply visualization methods developed for the purpose of displaying multivariate relationships within data, especially for situations that involve a large number of concurrent relationships. Our method is based on the concept of multivariate classification, and is implemented directly in VisIt, a production quality visualization package.

  19. Review of the literature and suggestions for the design of rodent survival studies for the identification of compounds that increase health and life span.

    Science.gov (United States)

    Spindler, Stephen Richard

    2012-02-01

    Much of the literature describing the search for agents that increase the life span of rodents was found to suffer from confounds. One-hundred-six studies, absent 20 contradictory melatonin studies, of compounds or combinations of compounds were reviewed. Only six studies reported both life span extension and food consumption data, thereby excluding the potential effects of caloric restriction. Six other studies reported life span extension without a change in body weight. However, weight can be an unreliable surrogate measure of caloric consumption. Twenty studies reported that food consumption or weight was unchanged, but it was unclear whether these data were anecdotal or systematic. Twenty-nine reported extended life span likely due to induced caloric restriction. Thirty-six studies reported no effect on life span, and three a decrease. The remaining studies suffer from more serious confounds. Though still widely cited, studies showing life span extension using short-lived or "enfeebled" rodents have not been shown to predict longevity effects in long-lived animals. We suggest improvements in experimental design that will enhance the reliability of the rodent life span literature. First, animals should receive measured quantities of food and its consumption monitored, preferably daily, and reported. Weights should be measured regularly and reported. Second, a genetically heterogeneous, long-lived rodent should be utilized. Third, chemically defined diets should be used. Fourth, a positive control (e.g., a calorically restricted group) is highly desirable. Fifth, drug dosages should be chosen based on surrogate endpoints or accepted cross-species scaling factors. These procedures should improve the reliability of the scientific literature and accelerate the identification of longevity and health span-enhancing agents.

  20. Software Practicalization for Analysis of Wind-Induced Vibrations of Large Span Roof Structures

    Institute of Scientific and Technical Information of China (English)

    ZHANG Enuo; YANG Weiguo; ZHEN Wei; NA Xiangqian

    2005-01-01

    Wind loads are key considerations in the structural design of large-span structures since wind loads can be more important than earthquake loads, especially for large flexible structures. The analysis of wind loads on large span roof structures (LSRS) requires large amounts of calculations. Due to the combined effects of horizontal and vertical winds, the wind-induced vibrations of LSRS are analyzed in this paper with the frequency domain method as the first application of method for the analysis of the wind response of LSRS. A program is developed to analyze the wind-induced vibrations due to a combination of wind vibration modes. The program, which predicts the wind vibration coefficient and the wind pressure acting on the LSRS, interfaces with other finite element software to facilitate analysis of wind loads in the design of LSRS. The effectiveness and accuracy of the frequency domain method have been verified by numerical analyses of practical projects.

  1. Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Webster, S.S.J.

    1993-04-05

    The osteogenic sarcoma is the dominant life-threatening pathology in lifespan studies of beagles exposed to alpha-emitting bone-seeking radionuclides. It was deduced from these studies that certain skeletal sites are more prone to develop tumors. This project sought to determine the bone cells at risk and their cell-specific radiation dose. The cell-specific radiation dose values are related to loss and high Ra-226 and Pu-239 induced osteogenic sarcoma sites, to test different dose response hypothesis and predict the extent of effects in humans.

  2. Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies

    Energy Technology Data Exchange (ETDEWEB)

    Webster, S.S.J.

    1993-04-05

    The osteogenic sarcoma is the dominant life-threatening pathology in lifespan studies of beagles exposed to alpha-emitting bone-seeking radionuclides. It was deduced from these studies that certain skeletal sites are more prone to develop tumors. This project sought to determine the bone cells at risk and their cell-specific radiation dose. The cell-specific radiation dose values are related to loss and high Ra-226 and Pu-239 induced osteogenic sarcoma sites, to test different dose response hypothesis and predict the extent of effects in humans.

  3. Problem-based learning spanning real and virtual words: a case study in Second Life

    Directory of Open Access Journals (Sweden)

    Judith Good

    2008-12-01

    Full Text Available There is a growing use of immersive virtual environments for educational purposes. However, much of this activity is not yet documented in the public domain, or is descriptive rather than analytical. This paper presents a case study in which university students were tasked with building an interactive learning experience using Second Life as a platform. Both problem-based learning and constructionism acted as framing pedagogies for the task, with students working in teams to design and build a learning experience which could potentially meet the needs of a real client in innovative ways which might not be possible in real life. A process account of the experience is provided, which examines how the pedagogies and contexts (real and virtual influence and enhance each other. The use of a virtual environment, combined with problem-based learning and constructionism, subtly changed the nature of the instructor–student relationship, allowed students to explore ‘problematic problems' in a motivating and relevant manner, provided students with greater ownership over their work, and allowed problems to be set which were flexible, but at the same time allowed for ease of assessment.

  4. Partial Reversal of Tissue Calcification and Extension of Life Span following Ammonium Nitrate Treatment of Klotho-Deficient Mice

    Directory of Open Access Journals (Sweden)

    Christina B. Leibrock

    2016-02-01

    Full Text Available Background/Aims: Klotho is required for the inhibitory effect of FGF23 on 1,25(OH2D3 formation and Klotho-hypomorphic mice (kl/kl suffer from severe tissue calcification due to excessive 1,25(OH2D3 formation with subsequent increase of Ca2+ and phosphate concentrations and stimulation of osteogenic signaling. The excessive tissue calcification dramatically accelerates aging and leads to premature death of the animals. Osteogenic signaling in those mice is disrupted by treatment with NH4Cl, which prevents tissue calcification and early death of kl/kl mice. The present study explored whether the beneficial effects of NH4Cl treatment could be mimicked by NH4NO3 treatment. Methods: The kl/kl mice had free access to tap water either without or with addition of NH4NO3 (0.28 M starting with the mating of the parental generation. Calcification of trachea, lung, kidney, stomach, heart and vessels was visualized by histology with von Kossa staining. Plasma phosphate concentration was determined utilizing photometry, blood gas and electrolytes utilizing a blood Gas and Chemistry Analysis System and plasma 1,25(OH2D3 concentration with ELISA. Results: In untreated kl/kl mice plasma 1,25(OH2D3 and phosphate concentrations were elevated, and the mice suffered from marked calcification of all tissues analyzed. Untreated kl/kl mice further suffered from respiratory acidosis due to marked lung emphysema. NH4NO3-treatment decreased both, blood pCO2 and HCO3-, decreased calcification of trachea, lung, kidney, stomach, heart and vessels and increased the life span of kl/kl mice more than 1.7-fold (♂ or 1.6-fold (♀ without significantly affecting extracellular pH or plasma concentrations of 1,25(OH2D3, Ca2+, phosphate, Na+, and K+. Conclusions: NH4NO3-treatment turns respiratory acidosis into metabolic acidosis and mitigates calcification thus leading to a substantial extension of kl/kl mice survival.

  5. Minocycline increases the life span and motor activity and decreases lipid peroxidation in manganese treated Drosophila melanogaster.

    Science.gov (United States)

    Bonilla, E; Contreras, R; Medina-Leendertz, S; Mora, M; Villalobos, V; Bravo, Y

    2012-03-29

    The objective of this study was to investigate the effect of Minocycline in the life span, motor activity, and lipid peroxidation of Drosophila melanogaster treated with manganese. Two days after emerging from the pupa male wild-type D. melanogaster were fed for 13 days with corn media containing 15 mM manganese. Then, they were divided in six groups of 300 flies each: group (a) remained treated with manganese (Mn group); group (b) began treatment with Minocycline (0.05 mM) (Mn-Minocycline group); group (c) received no additional treatment (Mn-no treatment group); group (d) simultaneously fed with manganese and Minocycline (Mn+Minocycline group). Additionally, a control (group e) with no treatment and another group (f) fed only with Minocycline after emerging from the pupa were added. All the manganese treated flies (group a) were dead on the 25th day. The life span in group f (101.66±1.33 days, mean S.E.M.) and of group b (97.00±3.46 days) were similar, but in both cases it was significantly higher than in group e (68.33±1.76 days), group c (67.05±2.30 days) and in those of group d (37.33±0.88). Manganese (groups a and d) decreased motor activity in D. melanogaster. In the Minocycline fed flies (groups b and f) a higher motor activity was detected. In Mn-Minocycline and Mn+Minocycline treated flies a significant decrease of MDA levels was detected when compared to the Minocycline group indicating that Minocycline and Mn appear to have a synergistic effect. In conclusion, Minocycline increased the life span and motor activity and decreased MDA formation of manganese treated D. melanogaster, probably by an inhibition of the production of reactive oxygen species. Manganese also exerted an antioxidant effect as shown by the significant decrease of MDA levels when compared to control flies.

  6. Key environmental variables determining the occurrence and life span of basiphilous dune slack vegetation

    NARCIS (Netherlands)

    Lammerts, EJ; Grootjans, AP

    Environmental processes controlling the occurrence of basiphilous pioneer vegetation were identified in seven representative dune slacks on the Dutch Wadden Sea Islands. The variation in vegetation and relations with soil and groundwater composition were established first. Cluster analysis of the

  7. A Modal Pushover Analysis on Multi-Span Concrete Bridges to Estimate Inelastic Seismic Responses

    Directory of Open Access Journals (Sweden)

    Pennung Warnitchai

    2007-01-01

    Full Text Available The performance of Modal Pushover Analysis (MPA in predicting the inelastic seismic response of multi-span concrete bridges is investigated. The bridge is subjected to lateral forces distributed proportionally over the span of the bridge in accordance to the product of mass and displaced shape. The bridge is pushed up to the target displacement determined from the peak displacement of the nth mode inelastic Single Degree of Freedom System derived from Uncoupled Modal Response History Analysis (UMRHA. The peak response from each mode is combined using Square-Root of Sum-of-Square (SRSS rule. Although the use of SRSS rule is not appropriate in this bridge and the displaced pattern is shifted from the elastic shape due to yielding, MPA can predict well the total peak response of the bridge in inelastic range.

  8. Non-linear buffeting response analysis of long-span suspension bridges with central buckle

    Science.gov (United States)

    Wang, Hao; Li, Aiqun; Zhao, Gengwen; Li, Jian

    2010-06-01

    The rigid central buckle employed in the Runyang Suspension Bridge (RSB) was the first time it was used in a suspension bridge in China. By using a spectral representation method and FFT technique combined with measured data, a 3D fluctuating wind field considering the tower wind effect is simulated. A novel FE model for buffeting analysis is then presented, in which a specific user-defined Matrix27 element in ANSYS is employed to simulate the aeroelastic forces and its stiffness or damping matrices are parameterized by wind velocity and vibration frequency. A nonlinear time history analysis is carried out to study the influence of the rigid central buckle on the wind-induced buffeting response of a long-span suspension bridge. The results can be used as a reference for wind resistance design of long-span suspension bridges with a rigid central buckle in the future.

  9. Uncoupling of pathways that promote postmitotic life span and apoptosis from replicative immortality of Caenorhabditis elegans germ cells.

    Science.gov (United States)

    Ahmed, Shawn

    2006-12-01

    A dichotomy exists between germ and somatic cells in most organisms, such that somatic cell lineages proliferate for a single generation, whereas the germ cell lineage has the capacity to proliferate from one generation to the next, indefinitely. Several theories have been proposed to explain the unlimited replicative life span of germ cells, including the elimination of damaged germ cells by apoptosis or expression of high levels of gene products that prevent aging in somatic cells. These theories were tested in the nematode Caenorhabditis elegans by examining the consequences of eliminating either apoptosis or the daf-16, daf-18 or sir-2.1 genes that promote longevity of postmitotic somatic cells. However, germ cells of strains deficient for these activities displayed an unlimited proliferative capacity. Thus, C. elegans germ cells retain their youthful character via alternative pathways that prevent or eliminate damage that accumulates as a consequence of cell proliferation.

  10. Mice deficient in the putative phospholipid flippase ATP11C exhibit altered erythrocyte shape, anemia, and reduced erythrocyte life span.

    Science.gov (United States)

    Yabas, Mehmet; Coupland, Lucy A; Cromer, Deborah; Winterberg, Markus; Teoh, Narci C; D'Rozario, James; Kirk, Kiaran; Bröer, Stefan; Parish, Christopher R; Enders, Anselm

    2014-07-11

    Transmembrane lipid transporters are believed to establish and maintain phospholipid asymmetry in biological membranes; however, little is known about the in vivo function of the specific transporters involved. Here, we report that developing erythrocytes from mice lacking the putative phosphatidylserine flippase ATP11C showed a lower rate of PS translocation in vitro compared with erythrocytes from wild-type littermates. Furthermore, the mutant mice had an elevated percentage of phosphatidylserine-exposing mature erythrocytes in the periphery. Although erythrocyte development in ATP11C-deficient mice was normal, the mature erythrocytes had an abnormal shape (stomatocytosis), and the life span of mature erythrocytes was shortened relative to that in control littermates, resulting in anemia in the mutant mice. Thus, our findings uncover an essential role for ATP11C in erythrocyte morphology and survival and provide a new candidate for the rare inherited blood disorder stomatocytosis with uncompensated anemia. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. "Where are all the lonely people?" A population-based study of high-risk groups across the life span

    DEFF Research Database (Denmark)

    Lasgaard, Mathias; Friis, Karina; Shevlin, Mark

    2016-01-01

    -demographic and health-related factors were associated with an increased risk of severe loneliness in specific age groups. Being female, having a low educational level and living in a deprived area were only associated with loneliness in adolescence/emerging adulthood. Receiving disability pensions and living alone (i......Background. Loneliness is a prevalent and urgent public health issue. Optimal planning of community approaches to loneliness requires a differentiated understanding of loneliness across the life span. We identified groups at high risk of loneliness by exploring the relationship between loneliness......Item Loneliness Scale. Results. The relation between loneliness and age took a shallow U-shaped distribution. Ethnic minority status, receiving disability pensions or being unemployed, living alone, prolonged mental disorder, and psychiatric treatment were strongly associated with severe loneliness. Socio...

  12. The size effect in corrosion greatly influences the predicted life span of concrete infrastructures.

    Science.gov (United States)

    Angst, Ueli M; Elsener, Bernhard

    2017-08-01

    Forecasting the life of concrete infrastructures in corrosive environments presents a long-standing and socially relevant challenge in science and engineering. Chloride-induced corrosion of reinforcing steel in concrete is the main cause for premature degradation of concrete infrastructures worldwide. Since the middle of the past century, this challenge has been tackled by using a conceptual approach relying on a threshold chloride concentration for corrosion initiation (Ccrit). All state-of-the-art models for forecasting chloride-induced steel corrosion in concrete are based on this concept. We present an experiment that shows that Ccrit depends strongly on the exposed steel surface area. The smaller the tested specimen is, the higher and the more variable Ccrit becomes. This size effect in the ability of reinforced concrete to withstand corrosion can be explained by the local conditions at the steel-concrete interface, which exhibit pronounced spatial variability. The size effect has major implications for the future use of the common concept of Ccrit. It questions the applicability of laboratory results to engineering structures and the reproducibility of typically small-scale laboratory testing. Finally, we show that the weakest link theory is suitable to transform Ccrit from small to large dimensions, which lays the basis for taking the size effect into account in the science and engineering of forecasting the durability of infrastructures.

  13. Conceptualization of the Life-Span Development Theory: Relevance for Sexual and Reproductive Health in Ghana

    Directory of Open Access Journals (Sweden)

    Baba Musah Iddrisu

    2013-06-01

    Full Text Available Sexual and reproductive health issues continue to generate concerns in contemporarysociety because it is essential to individuals, couples and families, as well as the social andeconomic development of communities and nations. The concept of sexual andreproductive health (SRH provides a comprehensive and integrated approach to healthneeds related to sexuality and reproduction when viewed from the lens of lifespandevelopment theory. It is a public health concern, human rights issue and is indispensableto the attainment of the Millennium Development Goals because three out of the eightgoals are directly related to SRH, while the others have a close relationship with health.The 1994 International Conference on Population and Development in Cairo provided animpetus for program planners, family planning researchers, service providers, policymakers and other stakeholders to recognize the importance of SRH internationally.Nonetheless, the global situation depicts clear inequities between developed anddeveloping regions. Also, women bear the major share of the burden of sexual andreproductive ill health compared to men. It is essential to close these regional and gendergaps since SRH is vital to our quality of life, as other major aspects of health. This paper,which is an exploration of the literature, highlights the (a importance of SRH across thehuman lifespan, (b determinants of SRH in Ghana, and (c challenges associated withSRH issues in Ghana. Also, implications of SRH for public health education, policy,practice and research are discussed.

  14. The free radical theory of aging in search of a strategy for increasing life span.

    Science.gov (United States)

    Ivanova, Diana G; Yankova, Tatyana M

    2013-01-01

    This overview is an attempt to throw a fresh look at the popular free radical theory of aging (referred to also as oxidative stress theory) which holds that the progressive decline in physiological functions is a result of accumulation of diverse deleterious changes caused by reactive oxygen species (ROS). We discuss the role of mitochondria as a major source of ROS in the cell and how these link accumulation of oxidative damage to the age-related changes in physiologic functions. The free radical theory of aging is analysed here from two different views of aging--one (the pessimistic view) that regards aging as the inevitable result of life activity the consequences of which are accumulation of errors in the genome and damage of the biomolecules, and the other (the optimistic view) which considers that it is the changes in mitochondrial pathways of apoptosis with age that cause the functional tissue changes and aging. We also discuss the possibility of delaying the aging process by appropriate diet or drug therapy, which includes also calorie restriction as a mechanism of modifying the generation of free radicals and body metabolism and thus extending lifespan as a result.

  15. Promoting sexuality across the life span for individuals with intellectual and developmental disabilities.

    Science.gov (United States)

    Ailey, Sarah H; Marks, Beth A; Crisp, Cheryl; Hahn, Joan Earle

    2003-06-01

    Sexuality is a human right that is important to all individuals regardless of age, gender, orientation, or developmental level. Sexuality is closely related to a person's self-concept and self-esteem. Individuals with I/DD have a right to sexuality and sexual expression. Nevertheless, persons with I/DD have historically been denied this right, and many structural and attitudinal barriers exist to their healthy sexuality. Paradigms in sexuality education have shifted toward recognizing sexuality as a human right, a major life resource, and an integral part of one's makeup. To broadly address the development of healthy sexuality for individuals with I/DD, the issue needs to be normalized, not ignored or avoided; which means involving parents, staff, and professionals. Working with parents to overcome parental overprotection and social isolation is critical. Parents can provide opportunities for their sons and daughters to network and form meaningful personal relationships, with peers including encouraging association with peers outside of school or work hours.

  16. Long-term aerobic exercise is associated with greater muscle strength throughout the life span.

    Science.gov (United States)

    Crane, Justin D; Macneil, Lauren G; Tarnopolsky, Mark A

    2013-06-01

    Aging is associated with a progressive decline in muscle strength, muscle mass, and aerobic capacity, which reduces mobility and impairs quality of life in elderly adults. Exercise is commonly employed to improve muscle function in individuals of all ages; however, chronic aerobic exercise is believed to largely impact cardiovascular function and oxidative metabolism, with minimal effects on muscle mass and strength. To study the effects of long-term aerobic exercise on muscle strength, we recruited 74 sedentary (SED) or highly aerobically active (ACT) men and women from within three distinct age groups (young: 20-39 years, middle: 40-64 years, and older: 65-86 years) and tested their aerobic capacity, isometric grip and knee extensor strength, and dynamic 1 repetition maximum knee extension. As expected, ACT subjects had greater maximal oxygen uptake and peak aerobic power output compared with SED subjects (p aerobic exercise appears to attenuate age-related reductions in muscle strength in addition to its cardiorespiratory and metabolic benefits.

  17. Language Development across the Life Span: A Neuropsychological/Neuroimaging Perspective

    Directory of Open Access Journals (Sweden)

    Mónica Rosselli

    2014-01-01

    Full Text Available Language development has been correlated with specific changes in brain development. The aim of this paper is to analyze the linguistic-brain associations that occur from birth through senescence. Findings from the neuropsychological and neuroimaging literature are reviewed, and the relationship of language changes observable in human development and the corresponding brain maturation processes across age groups are examined. Two major dimensions of language development are highlighted: naming (considered a major measure of lexical knowledge and verbal fluency (regarded as a major measure of language production ability. Developmental changes in the brain lateralization of language are discussed, emphasizing that in early life there is an increase in functional brain asymmetry for language, but that this asymmetry changes over time, and that changes in the volume of gray and white matter are age-sensitive. The effects of certain specific variables, such as gender, level of education, and bilingualism are also analyzed. General conclusions are presented and directions for future research are suggested.

  18. Brain growth across the life span in autism: age-specific changes in anatomical pathology.

    Science.gov (United States)

    Courchesne, Eric; Campbell, Kathleen; Solso, Stephanie

    2011-03-22

    Autism is marked by overgrowth of the brain at the earliest ages but not at older ages when decreases in structural volumes and neuron numbers are observed instead. This has led to the theory of age-specific anatomic abnormalities in autism. Here we report age-related changes in brain size in autistic and typical subjects from 12 months to 50 years of age based on analyses of 586 longitudinal and cross-sectional MRI scans. This dataset is several times larger than the largest autism study to date. Results demonstrate early brain overgrowth during infancy and the toddler years in autistic boys and girls, followed by an accelerated rate of decline in size and perhaps degeneration from adolescence to late middle age in this disorder. We theorize that underlying these age-specific changes in anatomic abnormalities in autism, there may also be age-specific changes in gene expression, molecular, synaptic, cellular, and circuit abnormalities. A peak age for detecting and studying the earliest fundamental biological underpinnings of autism is prenatal life and the first three postnatal years. Studies of the older autistic brain may not address original causes but are essential to discovering how best to help the older aging autistic person. Lastly, the theory of age-specific anatomic abnormalities in autism has broad implications for a wide range of work on the disorder including the design, validation, and interpretation of animal model, lymphocyte gene expression, brain gene expression, and genotype/CNV-anatomic phenotype studies.

  19. The size effect in corrosion greatly influences the predicted life span of concrete infrastructures

    Science.gov (United States)

    Angst, Ueli M.; Elsener, Bernhard

    2017-01-01

    Forecasting the life of concrete infrastructures in corrosive environments presents a long-standing and socially relevant challenge in science and engineering. Chloride-induced corrosion of reinforcing steel in concrete is the main cause for premature degradation of concrete infrastructures worldwide. Since the middle of the past century, this challenge has been tackled by using a conceptual approach relying on a threshold chloride concentration for corrosion initiation (Ccrit). All state-of-the-art models for forecasting chloride-induced steel corrosion in concrete are based on this concept. We present an experiment that shows that Ccrit depends strongly on the exposed steel surface area. The smaller the tested specimen is, the higher and the more variable Ccrit becomes. This size effect in the ability of reinforced concrete to withstand corrosion can be explained by the local conditions at the steel-concrete interface, which exhibit pronounced spatial variability. The size effect has major implications for the future use of the common concept of Ccrit. It questions the applicability of laboratory results to engineering structures and the reproducibility of typically small-scale laboratory testing. Finally, we show that the weakest link theory is suitable to transform Ccrit from small to large dimensions, which lays the basis for taking the size effect into account in the science and engineering of forecasting the durability of infrastructures. PMID:28782038

  20. Second-Order Nonlinear Analysis of Steel Tapered Beams Subjected to Span Loading

    Directory of Open Access Journals (Sweden)

    Ali Hadidi

    2014-03-01

    Full Text Available A second-order elastic analysis of tapered steel members with I-shaped sections subjected to span distributed and concentrated loadings is developed. Fixed end forces and moments as well as exact stiffness matrix of tapered Timoshenko-Euler beam are obtained with exact geometrical properties of sections. The simultaneous action of bending moment, shear, and axial force including P−δ effects is also considered in the analysis. A computer code has been developed in MATLAB software using a power series method to solve governing second-order differential equation of equilibrium with variable coefficients for beams with distributed span loading. A generalized matrix condensation technique is then utilized for analysis of beams with concentrated span loadings. The accuracy and efficiency of the results of the proposed method are verified through comparing them to those obtained from other approaches such as finite element methods, which indicates the robustness and time saving of this method even for large scale frames with tapered members.

  1. Carbon dynamics in aboveground biomass of co-dominant plant species: related rather to leaf life span than to species

    Science.gov (United States)

    Ostler, Ulrike; Schleip, Inga; Lattanzi, Fernando A.; Schnyder, Hans

    2016-04-01

    This study investigates the role of individual organisms in whole ecosystem carbon (C) fluxes. It is currently unknown if different plant community members share the same or different kinetics of C pools in aboveground biomass, thereby adding (or not) variability to the first steps in ecosystem C cycling. We assessed the residence times in metabolic and non-metabolic (or structural) C pools and the allocation pattern of assimilated C in aboveground plant parts of four co-existing, co-dominant species from different functional groups in a temperate grassland community. For this purpose continuous, 14-16 day long 13CO2/12CO2-labeling experiments were performed in Sept. 2006, May 2007 and Sept. 2007, and the tracer kinetics were analysed with compartmental modeling. In all experimental periods, the species shared vastly similar residence times in metabolic C (5-8 d). In contrast, the residence times in non-metabolic C ranged from 20 to 58 d (except one outlier) and the fraction of fixed C allocated to the non-metabolic pool from 7 to 45%. These variations in non-metabolic C kinetics were not systematically associated with species or experimental periods, but exhibited close relationships with (independent estimates of) leaf life span, particularly in the grasses. This adds new meaning to leaf life span as a functional trait in the leaf and plant economics spectrum and its implication for C cycle studies in grassland and also forest systems. As the four co-dominant species accounted for ~80% of total community shoot biomass, we should also expect that the observed similarities in pool kinetics and allocation will scale up to similar relationships at the community level.

  2. [The course of attention deficit hyperactivity disorder (ADHD) over the life span].

    Science.gov (United States)

    Koumoula, A

    2012-06-01

    Attention Deficit Hyperactivity Disorder is a neurodevelopmental disorder, associated with the maturation of the nervous system and appearing on a standard proceeding with special cognitive impairments. For many years ADHD was concerned as a typical childhood disorder. Long-term studies though, showed that an important percentage of children with ADHD grew as adults with ADHD. The clinical picture varies with the developmental stage. In pre-school years (3-5 years) the clinical picture is characterized by excessive physical activity, difficulty in cooperation with peers and non-compliance to the recommendations of adults. In school age (6-12 years), apart from the nuclear symptoms of the disorder, as described in the classification systems, i.e. inattention, hyperactivity and impulsivity, oppositional behavior often occurs, conflicts with peers and academic problems. In adolescence hyperactivity lessens, conflicts with parents continue and high risk behaviors often appear. In adults physical activity usually decreases significantly, while inattention and impulsivity still remain. With the passing of time the number of symptoms are usually reduced, however the impact and impairment caused by the disorder remain. The diagnosis of ADHD in adults requires a retrospective diagnosis of ADHD in childhood. Since childhood, comorbid disorders are common, most times continuing until adult life. The Oppositional Defiant Disorder during childhood is related to the presenting of Antisocial Personality Disorder in adults. On the other hand, emotional disorders, which are also rather common in children, adolescents and adults with ADHD, can be due to either common biological mechanisms or the long-standing effect of psychosocial and environmental factors which follow people with ADHD. The relationship between ADHD and substance abuse has been a subject of research, with the view of the existence of Conduct Disorder being necessary for a person to present a Substance Use Disorder

  3. Increase of Reproductive Life Span Delays Age of Onset of Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Dominik Frentzel

    2017-08-01

    Full Text Available One striking observation in Parkinson’s disease (PD is the remarkable gender difference in incidence and prevalence of the disease. Data on gender differences with regard to disease onset, motor and non-motor symptoms, and dopaminergic medication are limited. Furthermore, whether estrogen status affects disease onset and progression of PD is controversially discussed. In this retrospective single center study, we extracted clinical data of 226 ambulatory PD patients and compared age of disease onset, disease stage, motor impairment, non-motor symptoms, and dopaminergic medication between genders. We applied a matched-pairs design to adjust for age and disease duration. To determine the effect of estrogen-related reproductive factors including number of children, age at menarche, and menopause on the age of onset, we applied a standardized questionnaire and performed a regression analysis. The male to female ratio in the present PD cohort was 1.9:1 (147 men vs. 79 women. Male patients showed increased motor impairment than female patients. The levodopa equivalent daily dose was increased by 18.9% in male patients compared to female patients. Matched-pairs analysis confirmed the increased dose of dopaminergic medication in male patients. No differences were observed in age of onset, type of medication, and non-motor symptoms between both groups. Female reproductive factors including number of children, age at menarche, and age at menopause were positively associated with a delay of disease onset up to 30 months. The disease-modifying role of estrogen-related outcome measures warrants further clinical and experimental studies targeting gender differences, specifically hormone-dependent pathways in PD.

  4. Increase of Reproductive Life Span Delays Age of Onset of Parkinson’s Disease

    Science.gov (United States)

    Frentzel, Dominik; Judanin, Grigorij; Borozdina, Olga; Klucken, Jochen; Winkler, Jürgen; Schlachetzki, Johannes C. M.

    2017-01-01

    One striking observation in Parkinson’s disease (PD) is the remarkable gender difference in incidence and prevalence of the disease. Data on gender differences with regard to disease onset, motor and non-motor symptoms, and dopaminergic medication are limited. Furthermore, whether estrogen status affects disease onset and progression of PD is controversially discussed. In this retrospective single center study, we extracted clinical data of 226 ambulatory PD patients and compared age of disease onset, disease stage, motor impairment, non-motor symptoms, and dopaminergic medication between genders. We applied a matched-pairs design to adjust for age and disease duration. To determine the effect of estrogen-related reproductive factors including number of children, age at menarche, and menopause on the age of onset, we applied a standardized questionnaire and performed a regression analysis. The male to female ratio in the present PD cohort was 1.9:1 (147 men vs. 79 women). Male patients showed increased motor impairment than female patients. The levodopa equivalent daily dose was increased by 18.9% in male patients compared to female patients. Matched-pairs analysis confirmed the increased dose of dopaminergic medication in male patients. No differences were observed in age of onset, type of medication, and non-motor symptoms between both groups. Female reproductive factors including number of children, age at menarche, and age at menopause were positively associated with a delay of disease onset up to 30 months. The disease-modifying role of estrogen-related outcome measures warrants further clinical and experimental studies targeting gender differences, specifically hormone-dependent pathways in PD. PMID:28871235

  5. Delusional Disorder over the Reproductive Life Span: The Potential Influence of Menopause on the Clinical Course

    Directory of Open Access Journals (Sweden)

    Alexandre González-Rodríguez

    2015-01-01

    Full Text Available Background and Objectives. Recent evidence supports an association between estrogen levels and severity of psychopathology in schizophrenia women. Our main goal was to investigate whether delusional disorder (DD women with premenopausal onset and those with postmenopausal onset differ in demographic and clinical features. Methods. Psychopathological symptoms were assessed in 80 DD women (DSM-IV-TR, at baseline and after six and 24 months. Scores in the PANSS, PSP for functionality, HRSD 17 items, C-SSRS for suicide, and the SUMD were considered outcome variables. For comparison purposes, t- and χ2-tests were performed and nonparametric tests when necessary. Analysis of Covariance (ANCOVA was conducted for multivariate comparisons. Results. 57 out of 80 DD women completed the study. When unadjusted, DD with premenopausal onset had a longer DUP, higher educational level, and a tendency toward higher rates of gynaecological disorders. Erotomanic type was most frequent in DD women premenopausal onset, and somatic and jealous types were most frequent in those with postmenopausal onset. After 24 months, DD women with premenopausal onset showed higher depressive symptoms and a tendency toward higher rates of psychotic relapses. Conclusions. Our results support that some aspects of psychopathology and insight may differ according to the onset of DD and the reproductive status.

  6. Delusional Disorder over the Reproductive Life Span: The Potential Influence of Menopause on the Clinical Course.

    Science.gov (United States)

    González-Rodríguez, Alexandre; Molina-Andreu, Oriol; Penadés, Rafael; Garriga, Marina; Pons, Alexandre; Catalán, Rosa; Bernardo, Miguel

    2015-01-01

    Background and Objectives. Recent evidence supports an association between estrogen levels and severity of psychopathology in schizophrenia women. Our main goal was to investigate whether delusional disorder (DD) women with premenopausal onset and those with postmenopausal onset differ in demographic and clinical features. Methods. Psychopathological symptoms were assessed in 80 DD women (DSM-IV-TR), at baseline and after six and 24 months. Scores in the PANSS, PSP for functionality, HRSD 17 items, C-SSRS for suicide, and the SUMD were considered outcome variables. For comparison purposes, t- and χ (2)-tests were performed and nonparametric tests when necessary. Analysis of Covariance (ANCOVA) was conducted for multivariate comparisons. Results. 57 out of 80 DD women completed the study. When unadjusted, DD with premenopausal onset had a longer DUP, higher educational level, and a tendency toward higher rates of gynaecological disorders. Erotomanic type was most frequent in DD women premenopausal onset, and somatic and jealous types were most frequent in those with postmenopausal onset. After 24 months, DD women with premenopausal onset showed higher depressive symptoms and a tendency toward higher rates of psychotic relapses. Conclusions. Our results support that some aspects of psychopathology and insight may differ according to the onset of DD and the reproductive status.

  7. Perceptions of rapport across the life span: Gaze patterns and judgment accuracy.

    Science.gov (United States)

    Vicaria, Ishabel M; Bernieri, Frank J; Isaacowitz, Derek M

    2015-06-01

    Although age-related deficits in emotion perception have been established using photographs of individuals, the extension of these findings to dynamic displays and dyads is just beginning. Similarly, most eye-tracking research in the person perception literature, including those that study age differences, have focused on individual attributes gleaned from static images; to our knowledge, no previous research has considered cue use in dyadic judgments with eye-tracking. The current study employed a Brunswikian lens model analysis in conjunction with eye-tracking measurements to study age differences in the judgment of rapport, a social construct comprised of mutual attentiveness, positive feelings, and coordination between interacting partners. Judgment accuracy and cue utilization of younger (n = 47) and older (n = 46) adults were operationalized as correlations between a perceiver's judgments and criterion values within a set of 34 brief interaction videos in which 2 opposite sex college students discussed a controversial topic. No age differences emerged in the accuracy of judgments; however, pathways to accuracy differed by age: Younger adults' judgments relied on some behavioral cues more than older adults. In addition, eye-tracking analyses revealed that older adults spent more time looking at the bodies of the targets in the videos, whereas younger adults spent more time looking at the targets' heads. The contributions from both the lens model and eye-tracking findings provide distinct but complementary insights to our understanding of age-related continuities and shifts in social perceptual processing.

  8. Life span evolution in eusocial workers--a theoretical approach to understanding the effects of extrinsic mortality in a hierarchical system.

    Directory of Open Access Journals (Sweden)

    Boris H Kramer

    Full Text Available While the extraordinary life span of queens and division of labor in eusocial societies have been well studied, it is less clear which selective forces act on the short life span of workers. The disparity of life span between the queen and the workers is linked to a basic issue in sociobiology: How are the resources in a colony allocated between colony maintenance and reproduction? Resources for somatic maintenance of the colony can either be invested into quality or quantity of workers. Here, we present a theoretical optimization model that uses a hierarchical trade-off within insect colonies and extrinsic mortality to explain how different aging phenotypes could have evolved to keep resources secure in the colony. The model points to the significance of two factors. First, any investment that would generate a longer intrinsic life span for workers is lost if the individual dies from external causes while foraging. As a consequence, risky environments favor the evolution of workers with a shorter life span. Second, shorter-lived workers require less investment than long-lived ones, allowing the colony to allocate these resources to sexual reproduction or colony growth.

  9. Environmental effects on the expression of life span and aging: an extreme contrast between wild and captive cohorts of Telostylinus angusticollis (Diptera: Neriidae).

    Science.gov (United States)

    Kawasaki, Noriyoshi; Brassil, Chad E; Brooks, Robert C; Bonduriansky, Russell

    2008-09-01

    Most research on life span and aging has been based on captive populations of short-lived animals; however, we know very little about the expression of these traits in wild populations of such organisms. Because life span and aging are major components of fitness, the extent to which the results of many evolutionary studies in the laboratory can be generalized to natural settings depends on the degree to which the expression of life span and aging differ in natural environments versus laboratory environments and whether such environmental effects interact with phenotypic variation. We investigated life span and aging in Telostylinus angusticollis in the wild while simultaneously estimating these parameters under a range of conditions in a laboratory stock that was recently established from the same wild population. We found that males live less than one-fifth as long and age at least twice as rapidly in the wild as do their captive counterparts. In contrast, we found no evidence of aging in wild females. These striking sex-specific differences between captive and wild flies support the emerging view that environment exerts a profound influence on the expression of life span and aging. These findings have important implications for evolutionary gerontology and, more generally, for the interpretation of fitness estimates in captive populations.

  10. The mechanical response of multi-tower continuous-span suspension bridge deck pavement based on whole bridge analysis

    Institute of Scientific and Technical Information of China (English)

    Li Hongtao; Zhang Chenchen; Hu Jing; Qian Zhendong

    2011-01-01

    The effect of multiple span suspension structure on the mechanical response of bridge deck pavement was studied, and finite element analysis (FEM) of stress and strain of pavement according to the bridge floor system features of super-long and high flexibility was made. Meanwhile, the FEM results were compared with those of the single span suspension structure. Three-stage analytic hierarchy process (AHP) is developed to analyze the mechanical response including whole bridge analysis, partial beams section analysis and orthotropic plate analysis. The most unfavorable load position was determined by the numerical solutions acquired from each stage to study the main mechanical index of multiple span suspension structure. The FEM results showed that the mechanical response numerical solutions by using the three-stage AHP are greater than those by simplified boundary condition, and the force condition of multiple span suspension structure is worse than that of the single span suspension structure.

  11. Three-dimensional nonlinear flutter analysis of long-span suspension bridges during erection.

    Science.gov (United States)

    Zhang, Xin-jun; Sun, Bing-nan; Xiang, Hai-fan

    2003-01-01

    In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic forces caused by large deformation are fully considered. An interesting result obtained was that the bridge was more stable when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule. It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection.

  12. Three-dimensional nonlinear flutter analysis of long-span suspension bridges during erection

    Institute of Scientific and Technical Information of China (English)

    张新军; 孙炳楠; 项海帆

    2003-01-01

    In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic forces caused by large deformation are fully considered. An interesting result obtained was that the bridge was more stable when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule. It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection.

  13. Three-dimensional nonlinear flutter analysis of long-span suspension bridges during erection

    Institute of Scientific and Technical Information of China (English)

    张新军; 孙炳楠; 项海帆

    2003-01-01

    In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic forces caused by large deformation are fully considered. An interesting resuh obtained was that the bridge was more stable when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule. It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection.

  14. Transient aeroelastic responses and flutter analysis of a variable-span wing during the morphing process

    Institute of Scientific and Technical Information of China (English)

    Huang Ren; Qiu Zhiping

    2013-01-01

    To investigate the transient aeroelastic responses and flutter characteristics of a variable-span wing during the morphing process, a novel first-order state-space aeroelastic model is pro-posed. The time-varying structural model of the morphing wing is established based on the Euler-Bernoulli beam theory with time-dependent boundary conditions. A nondimensionalization method is used to translate the time-dependent boundary conditions to be time-independent. The time-domain aerodynamic forces are calculated by the reduced-order unsteady vortex lattice method. The morphing parameters, i.e., wing span length and morphing speed, are of particular interest for understanding the fundamental aeroelastic behavior of variable-span wings. A test case is proposed and numerical results indicate that the flutter characteristics are sensitive to both of the two morphing parameters. It could be noticed that the aeroelastic characteristics during the wing extracting process are more serious than those during the extending process at the same morphing speed by transient aeroelastic response analysis. In addition, a faster morphing process can get bet-ter aeroelastic performance while the mechanism comlexity will arise.

  15. Environmental enrichment improves age-related immune system impairment: long-term exposure since adulthood increases life span in mice.

    Science.gov (United States)

    Arranz, Lorena; De Castro, Nuria M; Baeza, Isabel; Maté, Ianire; Viveros, Maria Paz; De la Fuente, Mónica

    2010-08-01

    Age-related changes in immunity have been shown to highly influence morbidity and mortality. The aim of the present work was to study the effects of environmental enrichment (EE) (8-16 weeks) on several functions and oxidative stress parameters of peritoneal leukocytes, previously described as health and longevity markers, in mice at different ages, namely adult (44 +/- 4 weeks), old (69 +/- 4 weeks), and very old (92 +/- 4 weeks). Mortality rates were monitored in control and enriched animals, and effects on survival of long-term exposure to EE until natural death were determined. The results showed that exposure to EE was efficient in improving the function (i.e., macrophage chemotaxis and phagocytosis, lymphocyte chemotaxis and proliferation, natural killer cell activity, interleukin-2 and tumor necrosis factor-alpha levels) and decreasing the oxidative-inflammatory stress (i.e., lowered oxidized glutathione content, xanthine oxidase activity, expression of Toll-like receptors 2 and 4 on CD4 and CD8 cells, and increased reduced glutathione and glutathione peroxidase and catalase activities) of immune cells. These positive effects of EE were especially remarkable in animals at older ages. Importantly, long-term exposure to EE from adult age and until natural death stands out as a useful strategy to extend longevity. Thus, the present work confirms the importance of maintaining active mental and/or physical activity aiming to improve quality of life in terms of immunity, and demonstrates that this active life must be initiated at early stages of the aging process and preserved until death to improve life span.

  16. Seismic Response Analysis of Long-Span Suspen-Dome under Multi-Support Excitations

    Institute of Scientific and Technical Information of China (English)

    陈志华; 乔文涛; 王小盾

    2010-01-01

    A practical suspen-dome project, Changzhou Gym roof, is adopted as an example and its transient analysis based on the multi-support excitations of the earthquake wave is carried out. Compared with the single support excitation, the position and value of the maximum stress under multi-support excitations both change and the amount of elements with obvious changes is large and more than 70% of the total. Moreover, when other terms are not changed, this influence will decrease as the span decreases, but increa...

  17. Reduced mammalian target of rapamycin activity facilitates mitochondrial retrograde signaling and increases life span in normal human fibroblasts

    Science.gov (United States)

    Lerner, Chad; Bitto, Alessandro; Pulliam, Daniel; Nacarelli, Timothy; Konigsberg, Mina; Van Remmen, Holly; Torres, Claudio; Sell, Christian

    2017-01-01

    Summary Coordinated expression of mitochondrial and nuclear genes is required to maintain proper mitochondrial function. However, the precise mechanisms that ensure this coordination are not well defined. We find that signaling from mitochondria to the nucleus is influenced by mammalian target of rapamycin (mTOR) activity via changes in autophagy and p62/SQSTM1 turnover. Reducing mTOR activity increases autophagic flux, enhances mitochondrial membrane potential, reduces reactive oxygen species within the cell, and increases replicative life span. These effects appear to be mediated in part by an interaction between p62/SQSTM1 and Keap1. This interaction allows nuclear accumulation of the nuclear factor erythroid 2-like 2 (NFE2L2, also known as nuclear factor related factor 2 or NRF2), increased expression of the nuclear respiratory factor 1 (NRF1), and increased expression of nuclear-encoded mitochondrial genes, such as the mitochondrial transcription factor A, and mitochondrial-encoded genes involved in oxidative phosphorylation. These findings reveal a portion of the intracellular signaling network that couples mitochondrial turnover with mitochondrial renewal to maintain homeostasis within the cell and suggest mechanisms whereby a reduction in mTOR activity may enhance longevity. PMID:23795962

  18. Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency

    Institute of Scientific and Technical Information of China (English)

    LI Jing; PANG Shaojun; LIU Feng; SHAN Tifeng; GAO Suqin

    2013-01-01

    During sexual reproduction of seaweeds,spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes.The chemotactic ability of the sperm ensures fertilization success.Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions,the potential life-span of the sperm of two seaweeds,Saccharinajaponica and Undaria pinnatifida,was assessed by their ability to fertilize eggs.Results show that within 20-30 min after being discharged,sperm of both species could complete fertilization without an apparent decline in fertilization rate.Although fertilization rate 60-120 min after sperm discharge dropped significantly in both species,some sperm were viable enough to fertilize the eggs.In S.japonica,at 12℃,some sperm were able to fertilize eggs up to 12 h after discharge.In both species,egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups.Doubling the seeded male gametophytes of S.japonica in the SGT tests significantly increased the EDR,further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia.

  19. The Lignan Pinoresinol Induces Nuclear Translocation of DAF-16 in Caenorhabditis elegans but has No Effect on Life Span.

    Science.gov (United States)

    Koch, Karoline; Büchter, Christian; Havermann, Susannah; Wätjen, Wim

    2015-06-01

    The lignan pinoresinol is a constituent of flaxseed, sesame seeds and olive oil. Because of different molecular effects reported for this compound, e.g. antioxidative activity, pinoresinol is suggested to cause positive effects on humans. Because experimental data are limited, we have analysed the effects of the lignan on the nematode Caenorhabditis elegans: in spite of a strong antioxidative capacity detected in an in vitro assay, no antioxidative effects were detectable in vivo. In analogy to this result, no modulation of the sensitivity against thermal stress was detectable. However, incubation with pinoresinol caused an enhanced nuclear accumulation of the transcription factor DAF-16 (insulin/IGF-like signalling pathway). Using a strain with an enhanced oxidative stress level (mev-1 mutant), we clearly see an increase in stress resistance caused by this lignan, but no change in reactive oxygen species. Furthermore, we investigated the effects of pinoresinol on the life span of the nematode, but no modulation was found, neither in wild-type nor in mev-1 mutant nematodes. These results suggest that pinoresinol may exert pharmacologically interesting effects via modulation of the insulin-like signalling pathway in C. elegans as well as in other species like mammals due to the evolutionary conservation of this signalling pathway.

  20. Inventions in nanotechnological field provide increased strength and life span of the metal, composite and polymer, metallopolymer structures

    Directory of Open Access Journals (Sweden)

    VLASOV Vladimir Alexeevich

    2014-02-01

    Full Text Available The invention «The method of dispersion of nanoparticles in epoxy resin (RU 2500706» refers to nanotechnological field and it can be applied in different areas of machine industry, transport, construction, power engineering to increase strength and life span of the structures made of metal, composite and polymer, metallopolymer materials, for glue and glue and mechanical joints in different structure elements as well as for compositions which strengthen the stress concentration zones (in the form of holes, cutouts, fillet, thickness differentials in structures, to reform defects, microcracks and other damages occurring in production and performance of structures, to eliminate and encapsulate the gaps in holes and meeting-points of bolted and riveted joints. The invention «The method to produce nanosuspension for manufacturing polymer nanocomposite (RU 2500695» refers to the area of production of polymer nanocomposites based on reactiveplastic binder for space, aircraft, construction and other types of structures (glass-fiber plastic, carbon reinforced plastic, organic plastic, etc.. The method includes preparation of nanosuspension by introducing carbon nanotubes into reactiveplastic binder under ultrasonic treatment with intensity cavity zone 15–25 kW/m². The method makes it possible to optimize the degree of dispersion of carbon nanotubes in binder and to shorten production time of nanocomposites possessing increased strength due to even distribution of nanoparticles in nanocomposite.

  1. Liver-specific γ-glutamyl carboxylase-deficient mice display bleeding diathesis and short life span.

    Directory of Open Access Journals (Sweden)

    Kotaro Azuma

    Full Text Available Vitamin K is a fat-soluble vitamin that plays important roles in blood coagulation and bone metabolism. One of its functions is as a co-factor for γ-glutamyl carboxylase (Ggcx. Conventional knockout of Ggcx causes death shortly after birth in homozygous mice. We created Ggcx-floxed mice by inserting loxP sequences at the sites flanking exon 6 of Ggcx. By mating these mice with albumin-Cre mice, we generated Ggcx-deficient mice specifically in hepatocytes (Ggcx(Δliver/Δliver mice. In contrast to conventional Ggcx knockout mice, Ggcx(Δliver/Δliver mice had very low activity of Ggcx in the liver and survived several weeks after birth. Furthermore, compared with heterozygous mice (Ggcx(+/Δliver , Ggcx(Δliver/Δliver mice had shorter life spans. Ggcx(Δliver/Δliver mice displayed bleeding diathesis, which was accompanied by decreased activity of coagulation factors II and IX. Ggcx-floxed mice can prove useful in examining Ggcx functions in vivo.

  2. Sodium intake of special populations in the Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS) study.

    Science.gov (United States)

    Cotugna, Nancy; Fanelli-Kuczmarski, Marie; Fanelli-Kuczmarksi, Marie; Clymer, Julie; Hotchkiss, Lawrence; Zonderman, Alan B; Evans, Michele K

    2013-10-01

    The sodium intake of participants of the Healthy Aging in Neighborhoods of Diversity across the Life Span study who were in three of the special population groups identified by the Dietary Guidelines for Americans, 2010 (those with hypertension, African Americans, and those ≥51years) was analyzed to determine if they met sodium recommendations. The sample included 2152 African American and White subjects, aged 30-64years. Major dietary sources of sodium for each group were determined from two 24-hour dietary recalls, and dietary intakes were compared with sodium recommendations. Dietary potassium was also evaluated. The intakes of the groups studied exceeded 1500mg of sodium while their potassium intakes were lower than the Adequate Intake of 4700mg. The major contributors of sodium included "cold cuts, sausage, and franks," "protein foods," and yeast breads. Excessive sodium intake characterized the diet of an urban, socioeconomically diverse population who are hypertensive or at risk for having hypertension. These findings have implications for health professionals and the food industry. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Estrogens maintain bone mass by regulating expression of genes controlling function and life span in mature osteoclasts.

    Science.gov (United States)

    Imai, Yuuki; Youn, Ming-Young; Kondoh, Shino; Nakamura, Takashi; Kouzmenko, Alexander; Matsumoto, Takahiro; Takada, Ichiro; Takaoka, Kunio; Kato, Shigeaki

    2009-09-01

    Estrogens play a key role in regulation of bone mass and strength by controlling activity of bone-forming osteoblasts and bone-resorbing osteoclasts. Cellular effects of estrogens are mediated predominantly by the action of estrogen receptor alpha (ERalpha). In earlier studies, ablation of the ERalpha gene in mice did not result in osteoporotic phenotypes due to systemic endocrine disturbance and compensatory effects of elevated levels of testosterone. Despite the relatively well-established effects in osteoblasts, little is known about the direct action of estrogen in osteoclasts. Development in the last decade of more sophisticated genetic manipulation approaches opened new possibilities to explore cell-specific roles of nuclear receptors in bone tissue. Recently, we have generated osteoclast-specific ERalpha gene knockout mice and shown that in vivo estrogens directly regulate the life span of mature osteoclasts by inducing the expression of pro-apoptotic Fas ligand (FasL). Inhibitory effects of estrogens on osteoclast function were further studied in vitro. We observed sufficiently detectable ERalpha expression in osteoclasts differentiating from primary bone marrow cells or RAW264 cells, although levels of ERalpha were decreasing during progression of the differentiation into mature osteoclasts. Treatment with estrogens led to reduction in expression of osteoclast-specific genes controlling bone resorption activity. However, estrogens did not affect the size of multinucleated osteoclasts or number of nuclei in a mature osteoclast. In conclusion, in osteoclasts, estrogens function to inhibit bone resorption activity and vitality rather than differentiation.

  4. How much should we weigh for a long and healthy life span?The need to reconcile caloric restriction versus longevity with body mass index versus mortality data.

    Directory of Open Access Journals (Sweden)

    Antonello eLorenzini

    2014-07-01

    Full Text Available Total caloric restriction (CR without malnutrition is a well-established experimental approach to extend life span in laboratory animals. Although CR in humans is capable of shifting several endocrinological parameters it is not clear where the minimum inflection point of the U shaped curve linking body mass index (BMI with all-cause mortality lies. The exact trend of this curve, when used for planning preventive strategies for public health is of extreme importance. Normal BMI ranges from 18.5 to 24.9; many epidemiological studies show an inverse relationship between mortality and BMI inside the normal BMI range. Other studies show that the lowest mortality in the entire range of BMI is obtained in the overweight range (25 to 29.9. Reconciling the extension of life span in laboratory animals by experimental CR with the BMI-mortality curve of human epidemiology is not trivial. In fact, one interpretation is that the CR data are identifying a known: excess fat is deleterious for health; although a second interpretation may be that: additional leanness from a normal body weight may add health and life span delaying the process of aging. This short review hope to start a discussion aimed at finding the widest consensus on which weight range should be consider the healthiest for our species, contributing in this way to the picture of what is the correct life style for a long and healthy life span.

  5. Metal-based superoxide dismutase and catalase mimics reduce oxidative stress biomarkers and extend life span of Saccharomyces cerevisiae.

    Science.gov (United States)

    Ribeiro, Thales de P; Fonseca, Fernanda L; de Carvalho, Mariana D C; Godinho, Rodrigo M da C; de Almeida, Fernando Pereira; Saint'Pierre, Tatiana D; Rey, Nicolás A; Fernandes, Christiane; Horn, Adolfo; Pereira, Marcos D

    2017-01-15

    Aging is a natural process characterized by several biological changes. In this context, oxidative stress appears as a key factor that leads cells and organisms to severe dysfunctions and diseases. To cope with reactive oxygen species and oxidative-related damage, there has been increased use of superoxide dismutase (SOD)/catalase (CAT) biomimetic compounds. Recently, we have shown that three metal-based compounds {[Fe(HPClNOL)Cl2]NO3, [Cu(HPClNOL)(CH3CN)](ClO4)2 and Mn(HPClNOL)(Cl)2}, harboring in vitro SOD and/or CAT activities, were critical for protection of yeast cells against oxidative stress. In this work, treating Saccharomyces cerevisiae with these SOD/CAT mimics (25.0 µM/1 h), we highlight the pivotal role of these compounds to extend the life span of yeast during chronological aging. Evaluating lipid and protein oxidation of aged cells, it becomes evident that these mimics extend the life expectancy of yeast mainly due to the reduction in oxidative stress biomarkers. In addition, the treatment of yeast cells with these mimics regulated the amounts of lipid droplet occurrence, consistent with the requirement and protection of lipids for cell integrity during aging. Concerning SOD/CAT mimics uptake, using inductively coupled plasma mass spectrometry, we add new evidence that these complexes, besides being bioabsorbed by S. cerevisiae cells, can also affect metal homeostasis. Finally, our work presents a new application for these SOD/CAT mimics, which demonstrate a great potential to be employed as antiaging agents. Taken together, these promising results prompt future studies concerning the relevance of administration of these molecules against the emerging aging-related diseases such as Parkinson's, Alzheimer's and Huntington's.

  6. Vibration analysis of medium and small span bridges subjected to mixed marshalling freight trains

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It has been reported several times that train derailment occurs when mixed marshalling freight trains traverse bridges at high speeds in China.This study aims to explain this phenomenon numerically based on the train-bridge coupling vibration theory and its associated computer program.The train-bridge vibration characteristic is analyzed by a computer program when mixed marshalling freight trains traverse 32-meter-span prestressed concrete simple beam bridges.The mechanism that dynamic responses of the bridges are prominent and that empty trains are inclined to derail are derived from the dynamic responses analysis.The analysis indicates that the significant differences of axle loads between heavy vehicles and empty vehicles produce periodic forced loadings of large amplitudes.These periodic loadings cause severe vibration of bridges.In turn,severe vibration of the bridges produces intensive counteraction to empty vehicles.

  7. Whole Genome Analysis of Injectional Anthrax Identifies Two Disease Clusters Spanning More Than 13 Years

    Directory of Open Access Journals (Sweden)

    Paul Keim

    2015-11-01

    Lay Person Interpretation: Injectional anthrax has been plaguing heroin drug users across Europe for more than 10 years. In order to better understand this outbreak, we assessed genomic relationships of all available injectional anthrax strains from four countries spanning a >12 year period. Very few differences were identified using genome-based analysis, but these differentiated the isolates into two distinct clusters. This strongly supports a hypothesis of at least two separate anthrax spore contamination events perhaps during the drug production processes. Identification of two events would not have been possible from standard epidemiological analysis. These comprehensive data will be invaluable for classifying future injectional anthrax isolates and for future geographic attribution.

  8. Developmental and age-specific effects of selection on divergent virgin life span on fat content and starvation resistance in Drosophila melanogaster

    NARCIS (Netherlands)

    Vermeulen, Cornelis; Van de Zande, Louis; Bijlsma, R.

    2006-01-01

    Investigations into the genetic basis of longevity variation have shown life span to be positively correlated with starvation resistance and negatively with female fecundity, both of which rely on lipid content. To assess the firmness of this relation, we assayed correlated responses in age-specific

  9. Physical Attractiveness and Self-Esteem in Middle Childhood: Do Recent Life-Span Developmental Texts Perpetuate or Challenge Gender Stereotypes?

    Science.gov (United States)

    Hensley, Beth H.

    This document reports on an investigation focusing on how the content of introductory college psychology texts' content related to physical attractiveness and self-esteem. The primary objective of this study was to review how recently published life-span developmental texts present physical development in middle childhood as related to traditional…

  10. dSir2 in the Adult Fat Body, but Not in Muscles, Regulates Life Span in a Diet-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Kushal Kr. Banerjee

    2012-12-01

    Full Text Available Sir2, an evolutionarily conserved NAD+-dependent deacetylase, has been implicated as a key factor in mediating organismal life span. However, recent contradictory findings have brought into question the role of Sir2 and its orthologs in regulating organismal longevity. In this study, we report that Drosophila Sir2 (dSir2 in the adult fat body regulates longevity in a diet-dependent manner. We used inducible Gal4 drivers to knock down and overexpress dSir2 in a tissue-specific manner. A diet-dependent life span phenotype of dSir2 perturbations (both knockdown and overexpression in the fat body, but not muscles, negates the effects of background genetic mutations. In addition to providing clarity to the field, our study contrasts the ability of dSir2 in two metabolic tissues to affect longevity. We also show that dSir2 knockdown abrogates fat-body dFOXO-dependent life span extension. This report highlights the importance of the interplay between genetic factors and dietary inputs in determining organismal life spans.

  11. Sensitivity Analysis of Flutter Response of a Wing Incorporating Finite-Span Corrections

    Science.gov (United States)

    Issac, Jason Cherian; Kapania, Rakesh K.; Barthelemy, Jean-Francois M.

    1994-01-01

    Flutter analysis of a wing is performed in compressible flow using state-space representation of the unsteady aerodynamic behavior. Three different expressions are used to incorporate corrections due to the finite-span effects of the wing in estimating the lift-curve slope. The structural formulation is based on a Rayleigh-Pitz technique with Chebyshev polynomials used for the wing deflections. The aeroelastic equations are solved as an eigen-value problem to determine the flutter speed of the wing. The flutter speeds are found to be higher in these cases, when compared to that obtained without accounting for the finite-span effects. The derivatives of the flutter speed with respect to the shape parameters, namely: aspect ratio, area, taper ratio and sweep angle, are calculated analytically. The shape sensitivity derivatives give a linear approximation to the flutter speed curves over a range of values of the shape parameter which is perturbed. Flutter and sensitivity calculations are performed on a wing using a lifting-surface unsteady aerodynamic theory using modules from a system of programs called FAST.

  12. Urinary 8-hydroxyguanine may be a better marker of oxidative stress than 8-hydroxydeoxyguanosine in relation to the life spans of various species.

    Science.gov (United States)

    Svoboda, Peter; Maekawa, Muneyuki; Kawai, Kazuaki; Tominaga, Toshikazu; Savela, Kirsti; Kasai, Hiroshi

    2006-01-01

    Oxidative DNA damage is believed to be involved in the aging process. Species with shorter potential life spans generally have a higher specific metabolic rate (SMR), and would be expected to have increased levels of oxidative stress and DNA damage, as compared to long-lived species. An automatized HPLC method based on electrochemical detection was used to measure the levels of the oxidative DNA damage markers 8-hydroxydeoxyguanosine (8-OH-dG) and 8-hydroxyguanine (8-OH-Gua) in urinary samples from mammals with various potential life spans (mice, rats, guinea pigs, cats, chimpanzees, and humans). There was no significant linear correlation (r = -0.71, p = 0.11) between the species' potential life spans (log transformed) and the urinary levels of 8-OH-dG as normalized to creatinine (8-OH-dG/creatinine), although the species with longer life spans, such as chimpanzee and human, had among the lowest levels detected. In contrast, the negative linear correlation between the species' potential life span (log transformed) and the urinary levels of 8-OH-Gua as normalized to creatinine (8-OH-Gua/creatinine), was significant (r = -0.97, p = 0.002). In addition, there was a positive linear and significant correlation between SMR and 8-OH-dG/creatinine (r = 0.91, p = 0.01) or 8- OH-Gua/creatinine (r = 0.90, p = 0.01). These results suggest that 8-OH-Gua, rather than 8-OH-dG, may be a more general marker for oxidative damage.

  13. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    Directory of Open Access Journals (Sweden)

    Jorge E Ramos

    Full Text Available Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  14. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    Science.gov (United States)

    Ramos, Jorge E; Pecl, Gretta T; Moltschaniwskyj, Natalie A; Strugnell, Jan M; León, Rafael I; Semmens, Jayson M

    2014-01-01

    Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  15. Effects of PPP1R1B (DARPP-32 Polymorphism on Feedback-related Brain Potentials across the Life Span

    Directory of Open Access Journals (Sweden)

    Dorothea eHämmerer

    2013-03-01

    Full Text Available Maximizing gains during probabilistic reinforcement learning requires the updating of choice–outcome expectations at the time when the feedback about a specific choice or action is given. Extant theories and evidence suggest that dopaminergic modulation plays a crucial role in reinforcement learning and the updating of choice–outcome expectations. Furthermore, recently a positive component of the event-related potential (ERP about 200 msec (P2 after feedback has been suggested to reflect such updating. The efficacy of dopaminergic modulation changes across the life span. However, to date investigations of age-related differences in feedback-related P2 during reinforcement learning are still scarce. The present study thus aims to investigate whether individual differences in the feedback-related P2 would be associated with polymorphic variations in a dopamine relevant gene PPP1R1B (also known as DARPP-32 and whether the genetic effect may differ between age groups. We observed larger P2 amplitudes in individuals carrying the genotype associated with higher dopamine receptor efficacy, i.e., A allele homozygotes of a single nucleotide polymorphism (rs907094 of the PPP1R1B gene. Moreover, this effect was more pronounced in children and older adults in comparison to adolescents and younger adults. Together, our findings indicate that polymorphic variations in a dopamine relevant gene are associated with individual differences in brain-evoked potentials of outcome updating and hint at the possibility that genotype effects on neurocognitive phenotypes may vary as a function of brain maturation and aging.

  16. Boundary Spanning

    DEFF Research Database (Denmark)

    Zølner, Mette

    The paper explores how locals span boundaries between corporate and local levels. The aim is to better comprehend potentialities and challenges when MNCs draws on locals’ culture specific knowledge. The study is based on an in-depth, interpretive case study of boundary spanning by local actors in...... approach with pattern matching is a way to shed light on the tacit local knowledge that organizational actors cannot articulate and that an exclusively inductive research is not likely to unveil....

  17. Seismic response of continuous span bridges through fiber-based finite element analysis

    Institute of Scientific and Technical Information of China (English)

    Chiara Casarotti; Rui Pinho

    2006-01-01

    It is widely recognized that nonlinear time-history analysis constitutes the most accurate way to simulate the response of structures subjected to strong levels of seismic excitation. This analytical method is based on sound underlying principles and has the capability to reproduce the intrinsic inelastic dynamic behavior of structures. Nonetheless,comparisons with experimental results from large-scale testing of structures are still needed, in order to ensure adequate levels of confidence in this numerical methodology. The fiber modelling approach employed in the current endeavor inherently accounts for geometric nonlinearities and material inelasticity, without a need for calibration of plastic hinges mechanisms,typical in concentrated plasticity models. The resulting combination of analysis accuracy and modelling simplicity, allows thus to overcome the perhaps not fully justifiable sense of complexity associated to nonlinear dynamic analysis. The fiberbased modelling approach is employed in the framework of a finite element program downloaded from the Internet for seismic response analysis of framed structures. The reliability and accuracy of the program are demonstrated by numerically reproducing pseudo-dynamic tests on a four span continuous deck concrete bridge. Modelling assumptions are discussed,together with their implications on numerical results of the nonlinear time-history analyses, which were found to be in good agreement with experimental results.

  18. Positive regulation of DNA double strand break repair activity during differentiation of long life span cells: the example of adipogenesis.

    Directory of Open Access Journals (Sweden)

    Aline Meulle

    Full Text Available Little information is available on the ability of terminally differentiated cells to efficiently repair DNA double strand breaks (DSBs, and one might reasonably speculate that efficient DNA repair of these threatening DNA lesions, is needed in cells of long life span with no or limited regeneration from precursor. Few tissues are available besides neurons that allow the study of DNA DSBs repair activity in very long-lived cells. Adipocytes represent a suitable model since it is generally admitted that there is a very slow turnover of adipocytes in adult. Using both Pulse Field Gel Electrophoresis (PFGE and the disappearance of the phosphorylated form of the histone variant H2AX, we demonstrated that the ability to repair DSBs is increased during adipocyte differentiation using the murine pre-adipocyte cell line, 3T3F442A. In mammalian cells, DSBs are mainly repaired by the non-homologous end-joining pathway (NHEJ that relies on the DNA dependent protein kinase (DNA-PK activity. During the first 24 h following the commitment into adipogenesis, we show an increase in the expression and activity of the catalytic sub-unit of the DNA-PK complex, DNA-PKcs. The increased in DNA DSBs repair activity observed in adipocytes was due to the increase in DNA-PK activity as shown by the use of DNA-PK inhibitor or sub-clones of 3T3F442A deficient in DNA-PKcs using long term RNA interference. Interestingly, the up-regulation of DNA-PK does not regulate the differentiation program itself. Finally, similar positive regulation of DNA-PKcs expression and activity was observed during differentiation of primary culture of pre-adipocytes isolated from human sub-cutaneous adipose tissue. Our results show that DNA DSBs repair activity is up regulated during the early commitment into adipogenesis due to an up-regulation of DNA-PK expression and activity. In opposition to the general view that DNA DSBs repair is decreased during differentiation, our results demonstrate

  19. SOME EXAMPLES OF TRANSITION SPANS MINERALIZING AND ANALYSIS OF THEIR DYNAMICS

    Institute of Scientific and Technical Information of China (English)

    BI Hua; ZHAO Zhi-zhong; ZHU Wei-huang; YANG Yuan-gen; HUANG Lan; LIU Qiang

    2002-01-01

    The transitional span is a special environment for deposits. Taking peat, oil-gas, metallic deposits as examples, this paper discusses the spatial-temporal transitional characteristics of mineralization in transitional regions, points out the importance of the mineralization in transition spans, and analyses their dynamics finally.

  20. Is altered expression of hepatic insulin-related genes in growth hormone receptor knockout mice due to GH resistance or a difference in biological life spans?

    Science.gov (United States)

    Panici, Jacob A; Wang, Feiya; Bonkowski, Michael S; Spong, Adam; Bartke, Andrzej; Pawlikowska, Ludmila; Kwok, Pui-Yan; Masternak, Michal M

    2009-11-01

    Growth hormone receptor knockout (GHRKO) mice live about 40%-55% longer than their normal (N) littermates. Previous studies of 21-month-old GHRKO and N mice showed major alterations of the hepatic expression of genes involved in insulin signaling. Differences detected at this age may have been caused by the knockout of the growth hormone receptor (GHR) or by differences in biological age between GHRKO and N mice. To address this question, we compared GHRKO and N mice at ages corresponding to the same percentage of median life span to see if the differences of gene expression persisted. Comparison of GHRKO and N mice at approximately 50% of biological life span showed significant differences in hepatic expression of all 14 analyzed genes. We conclude that these changes are due to disruption of GHR gene and the consequent suppression of growth hormone signaling rather than to differences in "biological age" between mutant and normal animals sampled at the same chronological age.

  1. The Effects of Visual Attention Span and Phonological Decoding in Reading Comprehension in Dyslexia: A Path Analysis.

    Science.gov (United States)

    Chen, Chen; Schneps, Matthew H; Masyn, Katherine E; Thomson, Jennifer M

    2016-11-01

    Increasing evidence has shown visual attention span to be a factor, distinct from phonological skills, that explains single-word identification (pseudo-word/word reading) performance in dyslexia. Yet, little is known about how well visual attention span explains text comprehension. Observing reading comprehension in a sample of 105 high school students with dyslexia, we used a pathway analysis to examine the direct and indirect path between visual attention span and reading comprehension while controlling for other factors such as phonological awareness, letter identification, short-term memory, IQ and age. Integrating phonemic decoding efficiency skills in the analytic model, this study aimed to disentangle how visual attention span and phonological skills work together in reading comprehension for readers with dyslexia. We found visual attention span to have a significant direct effect on more difficult reading comprehension but not on an easier level. It also had a significant direct effect on pseudo-word identification but not on word identification. In addition, we found that visual attention span indirectly explains reading comprehension through pseudo-word reading and word reading skills. This study supports the hypothesis that at least part of the dyslexic profile can be explained by visual attention abilities. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Accurate stress analysis on rigid central buckle of Ions-span suspension bridges based on submodel method

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; LI AiQun; GUO Tong; MA Shuang

    2009-01-01

    Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-span of the suspension bridge in China. For such a super-long-span bridge, the traditional finite element (FE) modeling technique and stress analysis methods obviously cannot satisfy the needs of conducting accurate stress analysis on the central buckle. In this paper, the submodel method is introduced and for the first time used in analyzing the stresses of the central buckle. After an accurate FE submodel of the central buckle was specially established according to the analysis results from the whole FE model, the connection technique between the two-scale FE models was realized and the accurate stresses of the central buckle under various vehicle load cases were then conducted based on the submodel method. The calculation results were testified to be accurate and reliable by the field measurements, which show the efficiency and reliability of the submodel method on analyzing the mechanical condition of the central buckle of long-span suspension bridges. Finally, the working behavior and mechanical characteristics of the central buckle of the RSB under vehicle loads were analyzed based on the calculation and measurement results. The results obtained in this paper can provide theoretic references for analyzing and designing the rigid central buckle in long-span suspension bridges in future.

  3. Accurate stress analysis on rigid central buckle of long-span suspension bridges based on submodel method

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-span of the suspension bridge in China. For such a super-long-span bridge, the traditional finite element (FE) modeling technique and stress analysis methods obviously cannot satisfy the needs of conducting accurate stress analysis on the central buckle. In this paper, the submodel method is in- troduced and for the first time used in analyzing the stresses of the central buckle. After an accurate FE submodel of the central buckle was specially established according to the analysis results from the whole FE model, the connection technique between the two-scale FE models was realized and the ac- curate stresses of the central buckle under various vehicle load cases were then conducted based on the submodel method. The calculation results were testified to be accurate and reliable by the field measurements, which show the efficiency and reliability of the submodel method on analyzing the mechanical condition of the central buckle of long-span suspension bridges. Finally, the working be- havior and mechanical characteristics of the central buckle of the RSB under vehicle loads were ana- lyzed based on the calculation and measurement results. The results obtained in this paper can provide theoretic references for analyzing and designing the rigid central buckle in long-span suspension bridges in future.

  4. Sex effects on life span and senescence in the wild when dates of birth and death are unknown.

    Science.gov (United States)

    Zajitschek, Felix; Brassil, Chad E; Bonduriansky, Russell; Brooks, Robert C

    2009-06-01

    Males and females allocate and schedule reproductive effort in very different ways. Because the timing and amount of reproductive effort influence survival and thus the optimization of life histories, mortality and senescence are predicted to be sex specific. However, age-specific mortality rates of wild animals are often difficult to quantify in natural populations. Studies that report mortality rates from natural populations are, therefore, almost entirely confined to long-lived, easy-to-track species such as large mammals and birds. Here, we employ a novel approach using capture-mark-recapture data from a wild population of black field crickets (Teleogryllus commodus) to test for sex differences in demographic aging. In this species, the age of captured adults cannot be readily determined, and animals cannot be reliably captured or observed every night, resulting in demographic data on individuals whose dates of birth and death are unknown. We implement a recently developed life-table analysis for wild-caught individuals of unknown age, in combination with a well-established capture-mark-recapture methodology that models probabilistic dates of death. This unified analytical framework makes it possible to test for aging in wild, hard-to-track animals. Using these methods to fit Gompertz models of age-specific mortality, we show that male crickets have higher mortality rates throughout life than female crickets. Furthermore, males and females both exhibit increasing mortality rates with age, indicating senescence, but the rate of senescence is not sex specific. Thus, observed sex differences in longevity are probably due to differences in baseline mortality rather than aging. Our findings illustrate the complexity of the relationships between sex, background mortality, and senescence rate in wild populations, showing that the elevated mortality rate of males need not be coupled with an elevated rate of aging.

  5. Life and Death Decision Analysis.

    Science.gov (United States)

    1979-12-01

    LIFE SMOKING: CANCER, EMPHYSEMA, SHORTENED LIFE BATHING: FALLING, ELECTROCUTION CONTRACEPTION: DEATH , ILLNESS PREGNANCY: DEATH , ILLNESS ABORTION ...economic effect is the one with the highest probability of causing my death . -13- EXPECTED NET SYSTEM DESIGN BENEFIT TO ME DEATH DEATH (r A(excluding death ...0-AO81 424 STANFORD UNIV CALIF DEPT OF ENGtNEERING-ECONOM!C SYSTEMS F/6 12/1 LIFE ANDI DEATH DECISION ANALYSIS.CU) DEC 79 R A HOWARD N0OOIN-79-C-0036

  6. Analysis of Dynamic Characteristics of Submarine Free Spanning Pipelines by Complex Damping Method

    Institute of Scientific and Technical Information of China (English)

    傅强; 郭海燕; 杨新华

    2004-01-01

    Considering the effect of the internal flowing fluid and the external marine environmental condition, the differential equation for the vortex-induced vibration (VIV) of the free spanning pipeline is derived and is discretized by the Hermit interpolation function. The free vibration equation with the damping term is solved by the complex damping method for the natural frequency, and then the effect of fluid damping on the natural frequency of the free spanning pipeline is analyzed.The results show that fluid damping has a significant influence on the damped natural frequency of the free spanning pipeline in the lock-in state, while it has little influence when the pipeline is out of the lock-in state. In the meantime,the change of the free span length has the same effect on the damped natural frequency and the undamped natural frequency.

  7. Analysis of mechanical behaviors of big pipe roof for shallow buried large-span tunnel

    Institute of Scientific and Technical Information of China (English)

    Li Jian; Tan Zhongsheng; Yu Yu; Guo Xiaohong

    2013-01-01

    A series of researches on mechanical behaviors of big pipe roof for shallow large-span loess tunnel were carried out based on the Wenxiang tunnel in Zhengzhou-Xi’an Special Passenger Railway. The longitudinal de-formations of the pipe roofs were monitored and the mechanical behaviors of the pipe roofs were analyzed at the test section. A new double-parameter elastic foundation beam model for pipe roof in shallow tunnels was put for-ward in Wenxiang tunnel. The measured values and the calculation results agreed well with each other,revealing the force-deformation law of big pipe roof in loess tunnel:At about 15 m in front of the excavating face,the pipe roof starts to bear the load;at about 15 m behind the excavating face,the force of the pipe roof tends to be stabi-lized;the longitudinal deformation of the whole pipe roofs is groove-shaped distribution,and the largest force of pipe roofs is at the excavating face. Simultaneously,the results also indicate that mechanical behaviors of pipe roof closely relate to the location of the excavation face,the footage of the tunnelling cycle and the mechanics pa-rameters of pipe roof and rock. The conclusions can be reference for the design parameter optimization and the con-struction scheme selection of pipe roofs,and have been verified by the result of numerical analysis software FLAC3D and deformation monitoring.

  8. Damage assessment of a two-span RC slab using wavelet analysis

    Science.gov (United States)

    Zhu, X. Q.; Hao, H.

    2007-04-01

    A two-span RC slab that measures 6400mm×800mm×100mm with 3000mm spans and 200mm overhang on each end was tested to failure in the laboratory. UB sections were used as supports. The slab was designed according to the moment redistribution method with 11 N6 bars at 75mm centres for both positive and negative reinforcement. The slab was incrementally loaded at the middle of each span to different load levels to create crack damage using four-point loading. Twelve loading stages were performed with increasing maximum load level. Two load cells are used to record the static loads on left and right spans. The crack locations and lengths were monitored in addition to the displacement measurements. Four displacement transducers are located at two sides of the middle of each span to measure the deflection under the static load. Three sets of accelerometers with nine of them in each set are evenly distributed along the slab to measure the dynamic responses. The measured responses from the RC slab in different cracked damage states are analyzed using the wavelet transform (WT). The damping ratios and instantaneous frequency are extracted. The results show that the damping ratio and instantaneous frequency changes could be two good indicators of damage in the reinforced concrete structure.

  9. Whole Genome Analysis of Injectional Anthrax Identifies Two Disease Clusters Spanning More Than 13 Years.

    Science.gov (United States)

    Keim, Paul; Grunow, Roland; Vipond, Richard; Grass, Gregor; Hoffmaster, Alex; Birdsell, Dawn N; Klee, Silke R; Pullan, Steven; Antwerpen, Markus; Bayer, Brittany N; Latham, Jennie; Wiggins, Kristin; Hepp, Crystal; Pearson, Talima; Brooks, Tim; Sahl, Jason; Wagner, David M

    2015-11-01

    from the German Ministry of Defense (Sonderforschungsprojekt 25Z1-S-431,214). Support for sequencing was also obtained from Illumina, Inc. These sources had no role in the data generation or interpretation, and had not role in the manuscript preparation. We searched PubMed for any article published before Jun. 17, 2015, with the terms "Bacillus anthracis" and "heroin", or "injectional anthrax". Other than our previously published work (Price et al., 2012), we found no other relevant studies on elucidating the global phylogenetic relationships of B. anthracis strains associated with injectional anthrax caused by recreational heroin consumption of spore-contaminated drug. There were, however, publically available genome sequences of two strains involved (Price et al., 2012, Grunow et al., 2013) and the draft genome sequence of Bacillus anthracis UR-1, isolated from a German heroin user (Ruckert et al., 2012) with only limited information on the genotyping of closely related strains (Price et al., 2012, Grunow et al., 2013). Injectional anthrax has been plaguing heroin drug users across Europe for more than 10 years. In order to better understand this outbreak, we assessed genomic relationships of all available injectional anthrax strains from four countries spanning a > 12 year period. Very few differences were identified using genome-based analysis, but these differentiated the isolates into two distinct clusters. This strongly supports a hypothesis of at least two separate anthrax spore contamination events perhaps during the drug production processes. Identification of two events would not have been possible from standard epidemiological analysis. These comprehensive data will be invaluable for classifying future injectional anthrax isolates and for future geographic attribution.

  10. Life Cycle Inventory Analysis

    DEFF Research Database (Denmark)

    Bjørn, Anders; Moltesen, Andreas; Laurent, Alexis

    2017-01-01

    The inventory analysis is the third and often most time-consuming part of an LCA. The analysis is guided by the goal and scope definition, and its core activity is the collection and compilation of data on elementary flows from all processes in the studied product system(s) drawing on a combination...... and collecting data; (3) constructing and quality checking unit processes; (4) constructing LCI model and calculating LCI results; (5) preparing the basis for uncertainty management and sensitivity analysis; and (6) reporting....

  11. Non-stationary Buffeting Response Analysis of Long Span Suspension Bridge Under Strong Wind Loading

    Institute of Scientific and Technical Information of China (English)

    Wenfeng Huang; Kongqing Zou

    2016-01-01

    The non⁃stationary buffeting response of long span suspension bridge in time domain under strong wind loading is computed. Modeling method for generating non⁃stationary fluctuating winds with probabilistic model for non⁃stationary strong wind fields is first presented. Non⁃stationary wind forces induced by strong winds on bridge deck and tower are then given a brief introduction. Finally, Non⁃stationary buffeting response of Pulite Bridge in China, a long span suspension bridge, is computed by using ANSYS software under four working conditions with different combination of time⁃varying mean wind and time⁃varying variance. The case study further confirms that it is necessity of considering non⁃stationary buffeting response for long span suspension bridge under strong wind loading, rather than only stationary buffeting response.

  12. Analysis of Large-Scale Matter Distribution with the Minimal Spanning Tree Technique

    Science.gov (United States)

    Doroshkevich, A.; Turchaninov, V.

    The application of the Minimal Spanning Three technique to the description of large scale object distribution in observed and simulated catalogues is demonstrated. We show that it can be roughly described as a system of high density filaments half of which is accumulated by wall-like condensations.

  13. Genetic Dissection of Nutrition-Induced Plasticity in Insulin/Insulin-Like Growth Factor Signaling and Median Life Span in a Drosophila Multiparent Population.

    Science.gov (United States)

    Stanley, Patrick D; Ng'oma, Enoch; O'Day, Siri; King, Elizabeth G

    2017-06-01

    The nutritional environments that organisms experience are inherently variable, requiring tight coordination of how resources are allocated to different functions relative to the total amount of resources available. A growing body of evidence supports the hypothesis that key endocrine pathways play a fundamental role in this coordination. In particular, the insulin/insulin-like growth factor signaling (IIS) and target of rapamycin (TOR) pathways have been implicated in nutrition-dependent changes in metabolism and nutrient allocation. However, little is known about the genetic basis of standing variation in IIS/TOR or how diet-dependent changes in expression in this pathway influence phenotypes related to resource allocation. To characterize natural genetic variation in the IIS/TOR pathway, we used >250 recombinant inbred lines (RILs) derived from a multiparental mapping population, the Drosophila Synthetic Population Resource, to map transcript-level QTL of genes encoding 52 core IIS/TOR components in three different nutritional environments [dietary restriction (DR), control (C), and high sugar (HS)]. Nearly all genes, 87%, were significantly differentially expressed between diets, though not always in ways predicted by loss-of-function mutants. We identified cis (i.e., local) expression QTL (eQTL) for six genes, all of which are significant in multiple nutrient environments. Further, we identified trans (i.e., distant) eQTL for two genes, specific to a single nutrient environment. Our results are consistent with many small changes in the IIS/TOR pathways. A discriminant function analysis for the C and DR treatments identified a pattern of gene expression associated with the diet treatment. Mapping the composite discriminant function scores revealed a significant global eQTL within the DR diet. A correlation between the discriminant function scores and the median life span (r = 0.46) provides evidence that gene expression changes in response to diet are

  14. Caloric restriction restores the chronological life span of the Goa1 null mutant of Candida albicans in spite of high cell levels of ROS.

    Science.gov (United States)

    Chen, Hui; Calderone, Richard; Sun, Nuo; Wang, Yun; Li, Dongmei

    2012-12-01

    The Candida albicans Goa1p is required for mitochondrial functions. In a strain lacking GOA1 (GOA31), respiration, mitochondrial membrane potential, complex I (CI) activity of the electron transport chain, and ATP synthesis are significantly decreased. A shortened chronological life span (CLS) of GOA31 occurs in 2% glucose that is associated with an increase in cell reactive oxidant species (ROS) and apoptosis. We now show that caloric restriction (CR) in media containing 0.5% glucose instead of 2% glucose-SC extends the CLS to the level of parental and gene-reconstituted strains. Paradoxically, ROS levels in GOA31 far exceed those of control strains in 0.5% glucose and, as a consequence, increased lipid peroxidation occurs even though CLS is restored. Microarray analysis was used to characterize transcriptional changes during CR in GOA31. We found that CR shifts cells of all strains to a non-glucose carbon metabolism (β-oxidation). Our model of ROS formation in GOA31 follows the paradigm that the generation of oxygen radicals from β-oxidation of cell lipids via FADH(2) (CII) and NADH (CI) creates an unfavorable cellular FADH(2)/NADH ratio that causes a transient overload in CII activity resulting in excess free cell radicals. In GOA31 the CI and peroxisomal dysfunctions increase the levels of ROS compared to control strains. Recovery from high levels of ROS may be associated with an increase in iron and sugar transporters, as well as an anti-stress response that includes the SOD1 and GPX1. Thus, CR creates a favorable growth environment, but cells of GOA31 must overcome a high but transient ROS production.

  15. Antioxidant capacity of "Mexican arnica" Heterotheca inuloides Cass natural products and some derivatives: their anti-inflammatory evaluation and effect on C. elegans life span.

    Science.gov (United States)

    Rodríguez-Chávez, José Luis; Coballase-Urrutia, Elvia; Nieto-Camacho, Antonio; Delgado-Lamas, Guillermo

    2015-01-01

    It has been suggested that the accumulation of biomolecular damage caused by reactive oxygen species (ROS) contributes to aging. The antioxidant activity is related to the ability of certain compounds to protect against the potentially harmful effect of processes or reactions involving ROS. This ability is associated with the termination of free radical propagation in biological systems. From Heterotheca inuloides various compounds which have shown to possess antioxidant capacity and scavenging ROS. The aim of this study was to determine the antioxidant capacity of additional natural components isolated from H. inuloides and some semisynthetic derivatives, their anti-inflammatory activity and the effect on Caenorhabditis elegans nematode life span. Compounds showed ability to inhibit various biological processes such as lipid peroxidation, scavenge nonbiological important oxidants such as (1)O2, OH(∙), H2O2, and HOCl and scavenge non biological stable free radicals (DPPH). Some cadinane type compounds showed possess antioxidant, ROS scavenging capacity, anti-inflammatory activity, and effect on the C. elegans life span. Flavonoid type compounds increased the life of the nematode and quercetin was identified as the compound with the greatest activity. The modification of chemical structure led to a change in the antioxidant capacity, the anti-inflammatory activity, and the survival of the worm.

  16. Antioxidant Capacity of “Mexican Arnica” Heterotheca inuloides Cass Natural Products and Some Derivatives: Their Anti-Inflammatory Evaluation and Effect on C. elegans Life Span

    Directory of Open Access Journals (Sweden)

    José Luis Rodríguez-Chávez

    2015-01-01

    Full Text Available It has been suggested that the accumulation of biomolecular damage caused by reactive oxygen species (ROS contributes to aging. The antioxidant activity is related to the ability of certain compounds to protect against the potentially harmful effect of processes or reactions involving ROS. This ability is associated with the termination of free radical propagation in biological systems. From Heterotheca inuloides various compounds which have shown to possess antioxidant capacity and scavenging ROS. The aim of this study was to determine the antioxidant capacity of additional natural components isolated from H. inuloides and some semisynthetic derivatives, their anti-inflammatory activity and the effect on Caenorhabditis elegans nematode life span. Compounds showed ability to inhibit various biological processes such as lipid peroxidation, scavenge nonbiological important oxidants such as 1O2, OH∙, H2O2, and HOCl and scavenge non biological stable free radicals (DPPH. Some cadinane type compounds showed possess antioxidant, ROS scavenging capacity, anti-inflammatory activity, and effect on the C. elegans life span. Flavonoid type compounds increased the life of the nematode and quercetin was identified as the compound with the greatest activity. The modification of chemical structure led to a change in the antioxidant capacity, the anti-inflammatory activity, and the survival of the worm.

  17. GPS Dynamic Monitoring Experiment and Result Analysis of Long-Span Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For the sake of timely appraising the working condition of the bridge, measuring the dynamic characteristics of the bridge structure is very important and necessary. A GPS dynamic monitoring test was carried out in the Wuhan Baishazhou Bridge, which is one of the longest span cable-stayed bridges having been built in China. This paper introduces the experimental implementing scheme and data processing method. The vibration characteristics of the middle span of cable-stayed bridge are availably obtained by use of the spectral analytic approach. The measuring results are very identical to the theoretical designed values. The research demonstrates that, with GPS receiver of the high sampling rate and suitable data processing method, the vibration characteristics of the bridge structure can be determined with high accuracy.

  18. Multicamera system extrinsic stability analysis and large-span truss string structure displacement measurement.

    Science.gov (United States)

    Liu, Cong; Dong, Shuai; Mokhtar, Mohammed; He, Xiaoyuan; Lu, Jinyu; Wu, Xiaolong

    2016-10-10

    A novel technique for measuring the displacements of large-span truss string structures that employs multicamera systems is proposed. The coordinates of the stereo-vision systems are unified in a single global coordinate system by employing 3D data reconstructed using close-range photogrammetry. To estimate the camera's attitude motions during an experiment, an instantaneous extrinsic rectification algorithm was developed. Experiments in which a camera was rotated and translated were conducted to verify the accuracy and precision of the developed algorithm. In addition, the proposed multicamera systems were employed to analyze a large-span truss string structure. The displacement results obtained from numerical simulations and experiments using pre-calibration and rectification methods are compared in this paper, and the stability of the camera's extrinsic parameters is discussed.

  19. Stochastic finite element analysis of long-span bridges with CFRP cables under earthquake ground motion

    Indian Academy of Sciences (India)

    Özlem Çavdar; Alemdar Bayraktar; Süleyman Adanur; Hasan Basri Başaǧa

    2010-06-01

    Stochastic seismic analysis of long-span bridges with Carbon fibre reinforced polymer (CFRP) cables are presented in this study through combination of the advantages of the perturbation based stochastic finite element method (SFEM) and Monte Carlo simulation (MCS) method. Jindo cable-stayed and Fatih Sultan Mehmet (Second Bosporus) suspension bridges are chosen as an example. Carbon fibre reinforced polymer cable (CFRP) and steel cables are used separately, in which the cable’s cross sectional area is determined by the principle equivalent axial stiffness. Geometric nonlinear effects are considered in the analysis. Uncertainties in the material are taken into account and Kocaeli earthquake in 1999 is chosen as a ground motion. The efficiency and accuracy of the proposed algorithm are validated by comparing with results of MCS method. It can be stated that using of CFRP cables in long-span bridges subjected to earthquake forces is feasible.

  20. Towards Maximum Spanning Tree Model in Web 3.0 Design and Development for Students using Discriminant Analysis

    CERN Document Server

    Padma, S

    2012-01-01

    Web 3.0 is an evolving extension of the web 2.0 scenario. The perceptions regarding web 3.0 is different from person to person . Web 3.0 Architecture supports ubiquitous connectivity, network computing, open identity, intelligent web, distributed databases and intelligent applications. Some of the technologies which lead to the design and development of web 3.0 applications are Artificial intelligence, Automated reasoning, Cognitive architecture, Semantic web . An attempt is made to capture the requirements of Students inline with web 3.0 so as to bridge the gap between the design and development of web 3.0 applications and requirements among Students. Maximum Spanning Tree modeling of the requirements facilitate the identification of key areas and key attributes in the design and development of software products for Students in Web 3.0 using Discriminant analysis. Keywords : Web 3.0, Discriminant analysis, Design and Development, Model, Maximum Spanning Tree 1.

  1. Being Labeled as Gifted, Self-Appraisal, and Psychological Well-Being: A Life Span Developmental Perspective.

    Science.gov (United States)

    Holahan, Carole K.; Holahan, Charles J.

    1999-01-01

    Examines the relation of being labeled as intellectually gifted to a mid-life appraisal of having lived up to one's abilities and to psychological well-being at age 80. Learning at a younger age of membership in a study of intellectual giftedness was related to less likelihood of believing that one has lived up to one's intellectual abilities at…

  2. Karyotypic instability and centrosome aberrations in the progeny of finite life-span human mammary epithelial cells exposed to sparsely or densely ionizing radiation.

    Science.gov (United States)

    Sudo, Hiroko; Garbe, James; Stampfer, Martha R; Barcellos-Hoff, Mary Helen; Kronenberg, Amy

    2008-07-01

    The human breast is sensitive to radiation carcinogenesis, and genomic instability occurs early in breast cancer development. This study tests the hypothesis that ionizing radiation elicits genomic instability in finite life-span human mammary epithelial cells (HMEC) and asks whether densely ionizing radiation is a more potent inducer of instability. HMEC in a non-proliferative state were exposed to X rays or 1 GeV/nucleon iron ions followed by delayed plating. Karyotypic instability and centrosome aberrations were monitored in expanded clonal isolates. Severe karyotypic instability was common in the progeny of cells that survived X-ray or iron-ion exposure. There was a lower dose threshold for severe karyotypic instability after iron-ion exposure. More than 90% of X-irradiated colonies and >60% of iron-ion-irradiated colonies showed supernumerary centrosomes at levels above the 95% upper confidence limit of the mean for unirradiated clones. A dose response was observed for centrosome aberrations for each radiation type. There was a statistically significant association between the incidence of karyotypic instability and supernumerary centrosomes for iron-ion-exposed colonies and a weaker association for X-irradiated colonies. Thus genomic instability occurs frequently in finite life-span HMEC exposed to sparsely or densely ionizing radiation and may contribute to radiation-induced breast cancer.

  3. Phototoxic effect of UVR on wild type, ebony and yellow mutants of Drosophila melanogaster: Life Span, fertility, courtship and biochemical aspects

    Institute of Scientific and Technical Information of China (English)

    WANG ZhePeng; LIU RuiFang; WANG AnRu; DU LiLi; DENG XueMei

    2008-01-01

    Melanin plays an important role in protecting organisms from ultraviolet radiation (UVR). Therefore, it is possible that differently colored strains can show different sensitivities to UVR. In the present work, life span, fertility and courtship behavior of wild type (w), ebony (e) and yellow (y) strains of Drosophila melanogaster were studied to evaluate their sensitivity to ultraviolet (UV). Because a range of photo-toxic effects of UVR are mediated through generation of free radicals, levels of free radicals, lipid per-oxide (malondialdehyde, MDA) and superoxide dismutase (SOD) activity of three strains were examined to indicate their antioxidant defending ability and oxidative status. It was shown that w always had the highest lifespan and fertility not only in the control but also in UV-exposed groups. Moreover, lifespan and fertility of e were significantly higher (P0.05). MDA levels were increased in the UV dose-dependent manner (P=0.0495). In con-clusion, our results suggested that UVB can decrease life span and fertility of flies and do harm to courtship, which may be due to oxidative damage to flies tissues (e.g. central nervous system) induced by free radicals, w had the highest tolerance to UVR, which may be ascribed to its advantage of survival under the natural condition and at high level of SOD activity. Then differences of pigment between e and y in absorbing UV, shielding against UV and scavenging free radicals produced by UVR should be responsible for their different sensitivity to UVR.

  4. Dmp53, basket and drICE gene knockdown and polyphenol gallic acid increase life span and locomotor activity in a Drosophila Parkinson's disease model

    Directory of Open Access Journals (Sweden)

    Hector Flavio Ortega-Arellano

    2013-01-01

    Full Text Available Understanding the mechanism(s by which dopaminergic (DAergic neurons are eroded in Parkinson's disease (PD is critical for effective therapeutic strategies. By using the binary tyrosine hydroxylase (TH-Gal4/UAS-X RNAi Drosophila melanogaster system, we report that Dmp53, basket and drICE gene knockdown in dopaminergic neurons prolong life span (p < 0.05; log-rank test and locomotor activity (p < 0.05; χ² test in D. melanogaster lines chronically exposed to (1 mM paraquat (PQ, oxidative stress (OS generator compared to untreated transgenic fly lines. Likewise, knockdown flies displayed higher climbing performance than control flies. Amazingly, gallic acid (GA significantly protected DAergic neurons, ameliorated life span, and climbing abilities in knockdown fly lines treated with PQ compared to flies treated with PQ only. Therefore, silencing specific gene(s involved in neuronal death might constitute an excellent tool to study the response of DAergic neurons to OS stimuli. We propose that a therapy with antioxidants and selectively "switching off" death genes in DAergic neurons could provide a means for pre-clinical PD individuals to significantly ameliorate their disease condition.

  5. Effects of salinity on egg and fecal pellet production, development and survival, adult sex ratio and total life span in the calanoid copepod, Acartia tonsa: a laboratory study

    Science.gov (United States)

    Shayegan, Majid; Esmaeili Fereidouni, Abolghasem; Agh, Naser; Jani Khalili, Khosrow

    2016-07-01

    The effects of salinity on the copepod, Acartia tonsa in terms of daily egg production rate (EPR), hatching success, fecal pellet production rate (FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods (seven consecutive days). Results show EPR was affected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females (long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages (56.7% and 52.2%, respectively) were significantly observed at two salinities of 13 and 20 compared to that at 35 (25%). Total longevity of females was not affected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.

  6. The histone demethylase Dmel\\Kdm4A controls genes required for life span and male-specific sex determination in Drosophila.

    Science.gov (United States)

    Lorbeck, Meridith T; Singh, Neetu; Zervos, Ashley; Dhatta, Madhusmita; Lapchenko, Maria; Yang, Chen; Elefant, Felice

    2010-01-15

    Histone methylation plays an important role in regulating chromatin-mediated gene control and epigenetic-based memory systems that direct cell fate. Enzymes termed histone demethylases directly remove the methyl marks from histones, thus contributing to a dynamically regulated histone methylated genome; however, the biological functions of these newly identified enzymes remain unclear. The JMJD2A-D family belongs to the JmjC domain-containing family of histone demethylases (JHDMs). Here, we report the cloning and functional characterization of the Drosophila HDM gene Dmel\\Kdm4A that is a homolog of the human JMJD2 family. We show that homologs for three human JHDM families, JHDM1, JHDM2, and JMJD2, are present in Drosophila and that each is expressed during the Drosophila lifecycle. Disruption of Dmel\\Kdm4A results in a reduction of the male life span and a male-specific wing extension/twitching phenotype that occurs in response to other males and is reminiscent of an inter-male courtship phenotype involving the courtship song. Remarkably, certain genes associated with each of these phenotypes are significantly downregulated in response to Dmel\\Kdm4A loss, most notably the longevity associated Hsp22 gene and the male sex-determination fruitless gene. Our results have implications for the role of the epigenetic regulator Dmel\\Kdm4A in the control of genes involved in life span and male-specific sex determination in the fly.

  7. Dmp53, basket and drICE gene knockdown and polyphenol gallic acid increase life span and locomotor activity in a Drosophila Parkinson’s disease model

    Science.gov (United States)

    Ortega-Arellano, Hector Flavio; Jimenez-Del-Rio, Marlene; Velez-Pardo, Carlos

    2013-01-01

    Understanding the mechanism(s) by which dopaminergic (DAergic) neurons are eroded in Parkinson’s disease (PD) is critical for effective therapeutic strategies. By using the binary tyrosine hydroxylase (TH)-Gal4/UAS-X RNAi Drosophila melanogaster system, we report that Dmp53, basket and drICE gene knockdown in dopaminergic neurons prolong life span (p < 0.05; log-rank test) and locomotor activity (p < 0.05; χ2 test) in D. melanogaster lines chronically exposed to (1 mM) paraquat (PQ, oxidative stress (OS) generator) compared to untreated transgenic fly lines. Likewise, knockdown flies displayed higher climbing performance than control flies. Amazingly, gallic acid (GA) significantly protected DAergic neurons, ameliorated life span, and climbing abilities in knockdown fly lines treated with PQ compared to flies treated with PQ only. Therefore, silencing specific gene(s) involved in neuronal death might constitute an excellent tool to study the response of DAergic neurons to OS stimuli. We propose that a therapy with antioxidants and selectively “switching off” death genes in DAergic neurons could provide a means for pre-clinical PD individuals to significantly ameliorate their disease condition. PMID:24385865

  8. Polyphenolic drug composition based on benzenepolycarboxylic acids (BP-C3) increases life span and inhibits spontaneous tumorigenesis in female SHR mice

    Science.gov (United States)

    Anisimov, Vladimir N.; Popovich, Irina G.; Zabezhinski, Mark A.; Yurova, Maria N.; Tyndyk, Margarita L.; Anikin, Ivan V.; Egormin, Peter A.; Baldueva, Irina A.; Fedoros, Elena I.; Pigarev, Sergey E.; Panchenko, Andrey V.

    2016-01-01

    Effects of long-term application of novel polyphenolic composition BP-C3, containing polyphenolic benzenepolycarboxylic acids, vitamins and minerals on some biomarkers of aging, life span and spontaneous tumorigenesis has been studied in female SHR mice. Administration of BP-C3 with drinking water (0.005%) did not exert any toxic effect (did not have effect on general condition of animals, weight dynamics and consumption of food), postponed age-related switch-off of estrous function, caused slight reduction of body temperature. An increased survival was observed in mice treated with BP-C3 (p=0.00164, log rank test). BP-C3 increased mean lifespan – by 8.4%, lifespan of the last 10% of animals – by 12.4%, and life span of tumor-free mice – by 11.6%. A tendency in ability of BP-C3 to inhibit development of spontaneous tumors in mice was detected, though it did not reach the level of statistical significance (p=0.166, log rank test). The number of malignant mammary tumors was 1.5 times less and total number of tumors of various localizations was 1.6 times less in BP-C3 treated animals. Multiple tumors were registered in 8% of mice in the control group and no cases – in BP-C3 treated group. Thus, BP-C3 demonstrated some anti-carcinogenic and a pronounced geroprotective activity. PMID:27574962

  9. L-carnitine suppresses the onset of neuromuscular degeneration and increases the life span of mice with familial amyotrophic lateral sclerosis.

    Science.gov (United States)

    Kira, Yukimi; Nishikawa, Manabu; Ochi, Akemi; Sato, Eisuke; Inoue, Masayasu

    2006-01-27

    Amyotrophic lateral sclerosis (ALS) is a fatal disease caused by progressive degeneration of motor neurons in the spinal cord and motor cortex. Although the etiology of ALS remains unknown, a mutation of the gene encoding Cu,Zn-superoxide dismutase (SOD1) has been reported in 20% of familial cases of ALS (FALS). Transgenic mice that overexpress a mutated human SOD1 exhibit a phenotype and pathology similar to those observed in patients with FALS. Mitochondrial abnormality has been reported in patients with ALS and in animal models of FALS. We recently reported that L-carnitine, an essential cofactor for the beta-oxidation of long-chain fatty acids, effectively inhibits various types of mitochondrial injury and apoptosis both in vitro and in vivo. The present study demonstrates that oral administration of L-carnitine prior to disease onset significantly delayed the onset of signs of disease (log-rank P=0.0008), delayed deterioration of motor activity, and extended life span (log-rank P=0.0001) in transgenic mice carrying a human SOD1 gene with a G93A mutation (Tg). More importantly, subcutaneous injection of L-carnitine increased the life span of Tg mice (46% increase in male, 60% increase in female) even when given after the appearance of signs of disease.

  10. Life sciences domain analysis model.

    Science.gov (United States)

    Freimuth, Robert R; Freund, Elaine T; Schick, Lisa; Sharma, Mukesh K; Stafford, Grace A; Suzek, Baris E; Hernandez, Joyce; Hipp, Jason; Kelley, Jenny M; Rokicki, Konrad; Pan, Sue; Buckler, Andrew; Stokes, Todd H; Fernandez, Anna; Fore, Ian; Buetow, Kenneth H; Klemm, Juli D

    2012-01-01

    Meaningful exchange of information is a fundamental challenge in collaborative biomedical research. To help address this, the authors developed the Life Sciences Domain Analysis Model (LS DAM), an information model that provides a framework for communication among domain experts and technical teams developing information systems to support biomedical research. The LS DAM is harmonized with the Biomedical Research Integrated Domain Group (BRIDG) model of protocol-driven clinical research. Together, these models can facilitate data exchange for translational research. The content of the LS DAM was driven by analysis of life sciences and translational research scenarios and the concepts in the model are derived from existing information models, reference models and data exchange formats. The model is represented in the Unified Modeling Language and uses ISO 21090 data types. The LS DAM v2.2.1 is comprised of 130 classes and covers several core areas including Experiment, Molecular Biology, Molecular Databases and Specimen. Nearly half of these classes originate from the BRIDG model, emphasizing the semantic harmonization between these models. Validation of the LS DAM against independently derived information models, research scenarios and reference databases supports its general applicability to represent life sciences research. The LS DAM provides unambiguous definitions for concepts required to describe life sciences research. The processes established to achieve consensus among domain experts will be applied in future iterations and may be broadly applicable to other standardization efforts. The LS DAM provides common semantics for life sciences research. Through harmonization with BRIDG, it promotes interoperability in translational science.

  11. Dynamic response analysis of single-span guideway caused by high speed maglev train

    OpenAIRE

    2011-01-01

    High speed maglev is one of the most important reformations in the ground transportation systems because of its no physical contact nature. This paper intends to study the dynamic response of the single-span guideway induced by moving maglev train. The dynamic model of the maglev train-guideway system is established. In this model, a maglev train consists of three vehicles and each vehicle is regarded as a multibody system with 34 degrees-of-freedom. The guideway is modeled as a simply suppor...

  12. Life span extension by resveratrol, rapamycin, and metformin: The promise of dietary restriction mimetics for an healthy aging.

    Science.gov (United States)

    Mouchiroud, Laurent; Molin, Laurent; Dallière, Nicolas; Solari, Florence

    2010-01-01

    Life expectancy at the turn of the 20th century was 46 years on average worldwide and it is around 65 years today. The correlative increase in age-associated diseases incidence has a profound public health impact and is an important matter of concern for our societies. Aging is a complex, heterogeneous, and multifactorial phenomenon, which is the consequence of multiple interactions between genes and environment. In this review, we survey animals models that have been of great help for both investigating mechanism of aging and identifying molecules, which slow down the onset of age-related diseases. Resveratrol (RSV) is one of those. We will report evidences supporting RSV as a molecule that acts by mimicking the beneficial effects of dietary restriction, and may share common downstream targets with rapamycin and metformin. Although those molecules do not reveal all the secrets of the fountain of youth, they may help us maintaining the quality of life in the old age.

  13. Parameter analysis of anchor bolt support for large-span and jointed rock mass

    Institute of Scientific and Technical Information of China (English)

    LI Xi-bing; ZHOU Zi-long; LI Qi-yue; HU Liu-qing

    2005-01-01

    In order to obtain the optimal parameters of anchor bolt supporting system for large-span and jointed rock mass in Kaiyang Phosphor Mine, it is expensive and unavailable with the method of in-situ experiments. This paper describes a numerical modeling with discrete element method for the supporting effects of different type of anchor bolts. The anchor bolts with variant length of 0.5 m, 0.8 m, 1.0 m, diameter of 10 mm, 15 mm, 20 mm, setting spacing of 3.0 m, 2.5 m, 2.0 m, and setting angle of 10°, 20°, 30°, are simulated respectively. The results show that there exist optimal parameters of anchor bolt support for large-span and jointed rock mass. For the bolt support of the concerning, the optimal length is 2.5-3.5 m, the diameter is 25-35 mm, the spacing is 0.5-0.6 m, and the setting angle is 105°.

  14. Laplacian spectrum analysis and spanning tree algorithm for circuit partitioning problems

    Institute of Scientific and Technical Information of China (English)

    杨华中; 胡冠章

    2003-01-01

    The spectrum of a graph is the set of all eigenvalues of the Laplacian matrix of the graph. There is a closed relationship between the Laplacian spectrum of graphs and some properties of graphs such as connectivity. In the recent years Laplacian spectrum of graphs has been widely applied in many fields. The application of Laplacian spectrum of graphs to circuit partitioning problems is reviewed in this paper. A new criterion of circuit partitioning is proposed and the bounds of the partition ratio for weighted graphs are also presented. Moreover, the deficiency of graph-partitioning algorithms by Lapla-cian eigenvectors is addressed and an algorithm by means of the minimal spanning tree of a graph is proposed. By virtue of taking the graph structure into consideration this algorithm can fulfill general re-quirements of circuit partitioning.

  15. Effect of Span 60 on the Microstructure, Crystallization Kinetics, and Mechanical Properties of Stearic Acid Oleogels: An In-Depth Analysis.

    Science.gov (United States)

    Uvanesh, K; Sagiri, S S; Senthilguru, K; Pramanik, K; Banerjee, I; Anis, Arfat; Al-Zahrani, S M; Pal, Kunal

    2016-02-01

    Modulation of crystallization of stearic acid and its derivatives is important for tuning the properties of stearate oleogels. The present study delineates the crystallization of stearic acid in stearate oleogels in the presence of Span 60. Microarchitecture analysis revealed that stearic acid crystals in the oleogels changed its shape from plate-like structure to a branched architecture in the presence of Span 60. Consequently, a significant variation in the mobility of the solute molecules inside the oleogel (Fluorescence recovery after photobleaching studies, FRAP analysis) was observed. Thermal analysis (gelation kinetics and DSC) revealed shortening of nucleation induction time and secondary crystallization with an increase in the Span 60 concentration. Furthermore, isosolid diagram suggested better physical stability of the formulations at higher proportions of Span 60. XRD analysis indicated that there was a decrease in the crystal size and the crystallinity of the stearic acid crystals with an increase in Span 60 concentration in the Span 60 containing oleogels. However, crystal growth orientation was unidirectional and found unaltered with Span 60 concentration (Avarmi analysis using DSC data). The mechanical study indicated a composition-dependent variation in the viscoelastic properties (instantaneous [τ1 ], intermediate [τ2 ], and delayed [τ3 ] relaxation times) of the formulations. In conclusion, Span 60 can be used to alter the kinetics of the crystallization, crystal habit and crystal structure of stearic acid. This study provides a number of clues that could be used further for developing oleogel based formulation.

  16. Random seismic response and sensitivity analysis of uncertain multi-span continuous beams subjected to spatially varying ground motions

    Science.gov (United States)

    Li, Y. Y.; Zhang, Y. H.

    2016-09-01

    An analytical method is formulated for the seismic analysis of multi-span continuous beams with random structural parameters subjected to spatially varying ground motions. An earthquake-induced ground motion is modelled as a stationary random process defined by power spectral density function, and the spatial variation is considered. The physical parameters of the multi-span beams are random and modelled as continuous random Gaussian variables. The stationary random responses are determined as approximate explicit functions of the structural parameters. Direct differentiation of these functions with respect to the structural parameters provides analytical expressions of the sensitivities of the stationary responses. On the basis of Taylor expansion, the statistic moments of the random responses are obtained. Taking the four-span beam as an illustrative example, the mean value and standard deviation of the random responses are computed and compared with those from Monte Carlo simulation to demonstrate the accuracy of the proposed method. Results are illustrated for the influence of different structural parameters on the statistic moments of the random responses. It is found that randomness in Young's modulus and the mass per unit length has approximate equivalent and significant influence on the random responses, while that of damping is negligible.

  17. Mice Deficient in the Putative Phospholipid Flippase ATP11C Exhibit Altered Erythrocyte Shape, Anemia, and Reduced Erythrocyte Life Span*♦

    Science.gov (United States)

    Yabas, Mehmet; Coupland, Lucy A.; Cromer, Deborah; Winterberg, Markus; Teoh, Narci C.; D'Rozario, James; Kirk, Kiaran; Bröer, Stefan; Parish, Christopher R.; Enders, Anselm

    2014-01-01

    Transmembrane lipid transporters are believed to establish and maintain phospholipid asymmetry in biological membranes; however, little is known about the in vivo function of the specific transporters involved. Here, we report that developing erythrocytes from mice lacking the putative phosphatidylserine flippase ATP11C showed a lower rate of PS translocation in vitro compared with erythrocytes from wild-type littermates. Furthermore, the mutant mice had an elevated percentage of phosphatidylserine-exposing mature erythrocytes in the periphery. Although erythrocyte development in ATP11C-deficient mice was normal, the mature erythrocytes had an abnormal shape (stomatocytosis), and the life span of mature erythrocytes was shortened relative to that in control littermates, resulting in anemia in the mutant mice. Thus, our findings uncover an essential role for ATP11C in erythrocyte morphology and survival and provide a new candidate for the rare inherited blood disorder stomatocytosis with uncompensated anemia. PMID:24898253

  18. The Tölz Temporal Topography Study: mapping the visual field across the life span. Part I: the topography of light detection and temporal-information processing.

    Science.gov (United States)

    Poggel, Dorothe A; Treutwein, Bernhard; Calmanti, Claudia; Strasburger, Hans

    2012-08-01

    Temporal performance parameters vary across the visual field. Their topographical distributions relative to each other and relative to basic visual performance measures and their relative change over the life span are unknown. Our goal was to characterize the topography and age-related change of temporal performance. We acquired visual field maps in 95 healthy participants (age: 10-90 years): perimetric thresholds, double-pulse resolution (DPR), reaction times (RTs), and letter contrast thresholds. DPR and perimetric thresholds increased with eccentricity and age; the periphery showed a more pronounced age-related increase than the center. RT increased only slightly and uniformly with eccentricity. It remained almost constant up to the age of 60, a marked change occurring only above 80. Overall, age was a poor predictor of functionality. Performance decline could be explained only in part by the aging of the retina and optic media. In Part II, we therefore examine higher visual and cognitive functions.

  19. A unifying perspective on personality pathology across the life span: developmental considerations for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders.

    Science.gov (United States)

    Tackett, Jennifer L; Balsis, Steve; Oltmanns, Thomas F; Krueger, Robert F

    2009-01-01

    Proposed changes in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) include replacing current personality disorder (PD) categories on Axis II with a taxonomy of dimensional maladaptive personality traits. Most of the work on dimensional models of personality pathology, and on personality disorders per se, has been conducted on young and middle-aged adult populations. Numerous questions remain regarding the applicability and limitations of applying various PD models to early and later life. In the present paper, we provide an overview of such dimensional models and review current proposals for conceptualizing PDs in DSM-V. Next, we extensively review existing evidence on the development, measurement, and manifestation of personality pathology in early and later life focusing on those issues deemed most relevant for informing DSM-V. Finally, we present overall conclusions regarding the need to incorporate developmental issues in conceptualizing PDs in DSM-V and highlight the advantages of a dimensional model in unifying PD perspectives across the life span.

  20. Health Monitoring and Evaluation of Long-Span Bridges Based on Sensing and Data Analysis: A Survey.

    Science.gov (United States)

    Zhou, Jianting; Li, Xiaogang; Xia, Runchuan; Yang, Jun; Zhang, Hong

    2017-03-16

    Aimed at the health monitoring and evaluation of bridges based on sensing technology, the monitoring contents of different structural types of long-span bridges were defined. Then, the definition, classification, selection principle, and installation requirements of the sensors were summarized. The concept was proposed that new adaptable long-life sensors could be developed by new theories and new effects. The principle and methods to select controlled sections and optimize the layout design of measuring points were illustrated. The functional requirements were elaborated on about the acquisition, transmission, processing, and management of sensing information. Some advanced concepts about the method of bridge safety evaluation were demonstrated and technology bottlenecks in the current safety evaluation were also put forward. Ultimately, combined with engineering practices, an application was carried out. The results showed that new, intelligent, and reliable sensor technology would be one of the main future development directions in the long-span bridge health monitoring and evaluation field. Also, it was imperative to optimize the design of the health monitoring system and realize its standardization. Moreover, it is a heavy responsibility to explore new thoughts and new concepts regarding practical bridge safety and evaluation technology.

  1. Health Monitoring and Evaluation of Long-Span Bridges Based on Sensing and Data Analysis: A Survey

    Directory of Open Access Journals (Sweden)

    Jianting Zhou

    2017-03-01

    Full Text Available Aimed at the health monitoring and evaluation of bridges based on sensing technology, the monitoring contents of different structural types of long-span bridges were defined. Then, the definition, classification, selection principle, and installation requirements of the sensors were summarized. The concept was proposed that new adaptable long-life sensors could be developed by new theories and new effects. The principle and methods to select controlled sections and optimize the layout design of measuring points were illustrated. The functional requirements were elaborated on about the acquisition, transmission, processing, and management of sensing information. Some advanced concepts about the method of bridge safety evaluation were demonstrated and technology bottlenecks in the current safety evaluation were also put forward. Ultimately, combined with engineering practices, an application was carried out. The results showed that new, intelligent, and reliable sensor technology would be one of the main future development directions in the long-span bridge health monitoring and evaluation field. Also, it was imperative to optimize the design of the health monitoring system and realize its standardization. Moreover, it is a heavy responsibility to explore new thoughts and new concepts regarding practical bridge safety and evaluation technology.

  2. Differential effects of IGF-1 deficiency during the life span on structural and biomechanical properties in the tibia of aged mice.

    Science.gov (United States)

    Ashpole, Nicole M; Herron, Jacquelyn C; Estep, Patrick N; Logan, Sreemathi; Hodges, Erik L; Yabluchanskiy, Andriy; Humphrey, Mary Beth; Sonntag, William E

    2016-04-01

    Advanced aging is associated with the loss of structural and biomechanical properties in bones, which increases the risk for bone fracture. Aging is also associated with reductions in circulating levels of the anabolic signaling hormone, insulin-like growth factor (IGF)-1. While the role of IGF-1 in bone development has been well characterized, the impact of the age-related loss of IGF-1 on bone aging remains controversial. Here, we describe the effects of reducing IGF-1 at multiple time points in the mouse life span--early in postnatal development, early adulthood, or late adulthood on tibia bone aging in both male and female igf (f/f) mice. Bone structure was analyzed at 27 months of age using microCT. We find that age-related reductions in cortical bone fraction, cortical thickness, and tissue mineral density were more pronounced when IGF-1 was reduced early in life and not in late adulthood. Three-point bone bending assays revealed that IGF-1 deficiency early in life resulted in reduced maximum force, maximum bending moment, and bone stiffness in aged males and females. The effects of IGF-1 on bone aging are microenvironment specific, as early-life loss of IGF-1 resulted in decreased cortical bone structure and strength along the diaphysis while significantly increasing trabecular bone fraction and trabecular number at the proximal metaphysis. The increases in trabecular bone were limited to males, as early-life loss of IGF-1 did not alter bone fraction or number in females. Together, our data suggest that the age-related loss of IGF-1 influences tibia bone aging in a sex-specific, microenvironment-specific, and time-dependent manner.

  3. Changes in gas exchange characteristics during the life span of giant sequoia: Implications for response to current and future concentrations of atmospheric ozone

    Energy Technology Data Exchange (ETDEWEB)

    Grulke, N.E.; Miller, P.R. (USDA Forest Service, Riverside, CA (United States))

    Native stands of giant sequoia are being exposed to relatively high concentrations of atmospheric ozone produced in urban and agricultural areas upwind. The expected change in environmental conditions over the next 100 y is likely to be unprecendented in the life span (ca 2,500 y) of giant sequoia. Changes in the physiological responses of three age classes of giant sequoia (current year, 12 y and 25 y) to different concentrations of ozone were determined, and age-related differences in sensitivity to pollutants were assessed by examining physiological changes (gas exchange, water use efficiency) across the life span of giant sequoia. The CO[sub 2] exchange rate (CER) was greater in current year (12.1 [mu]mol CO[sub 2]/m[sup 2]s) and 2 year old seedlings (4.8 [mu]mol CO[sub 2]/m[sup 2]s) than in all older trees (average of 3.0 [mu]mol CO[sub 2]/m[sup 2]s). Dark respiration was highest for current year seedlings and was increased twofold in symptotic individuals exposed to elevated ozone concentrations. Stomatal conductance was greater in current-year and 2 year old seedlings (335 and 200 mmol H[sub 2]O/m[sup 2]s), respectively, than in all older trees (50 mmol H[sub 2]O/m[sup 2]s), indicating that the ozone concentration in substomatol cavities is higher in young seedlings than in older trees. Significant changes in water use efficiency occurred in trees between ages 5 and 20 years. It is concluded that giant sequoia seedlings are sensitive to atmospheric ozone until they are ca 5 y old. Low conductance, high water use efficiency, and compact mesophyll all contribute to a natural ozone tolerance, or defense, or both, in foliage of older trees. 11 refs., 1 fig., 1 tab.

  4. Simple and difficult mathematics in children: a minimum spanning tree EEG network analysis.

    Science.gov (United States)

    Vourkas, Michael; Karakonstantaki, Eleni; Simos, Panagiotis G; Tsirka, Vasso; Antonakakis, Marios; Vamvoukas, Michael; Stam, Cornelis; Dimitriadis, Stavros; Micheloyannis, Sifis

    2014-07-25

    Sensor-level network characteristics associated with arithmetic tasks varying in complexity were estimated using tools from modern network theory. EEG signals from children with math difficulties (MD) and typically achieving controls (NI) were analyzed using minimum spanning tree (MST) indices derived from Phase Lag Index values - a graph method that corrects for comparison bias. Results demonstrated progressive modulation of certain MST parameters with increased task difficulty. These findings were consistent with more distributed network activation in the theta band, and greater network integration (i.e., tighter communication between involved regions) in the alpha band as task demands increased. There was also evidence of stronger intraregional signal inter-dependencies in the higher frequency bands during the complex math task. Although these findings did not differ between groups, several MST parameters were positively correlated with individual performance on psychometric math tasks involving similar operations, especially in the NI group. The findings support the potential utility of MST analyses to evaluate function-related electrocortical reactivity over a wide range of EEG frequencies in children.

  5. Thermal correlation analysis of a long-span suspension bridge static responses

    Science.gov (United States)

    Zhou, Linren; Chen, Lan; Xia, Yong; Brownjohn, James M. W.

    2016-04-01

    Harsh service environment degenerates the performance of bridges even leads to catastrophic collapse. Structural temperature has been widely recognized as one of the most negative environmental effects on bridges. The structural responses are deeply affected by the variation and distribution of temperatures on bridges. Therefore, identifying the correlations between them is a significant issue for structural safety assessment. In this study, the relationships between the temperature induced static response and the surrounding weather factors are investigated based on the long-term field measurements of a long-span suspension bridge. The correlations of the meteorological parameters between the bridge filed and the nearby weather station, and the relations of structural static responses to the air temperature, are investigated. The results indicate that relationships of meteorological parameters between nearby weather station and the bridge field can be predicted. The correlation between the static responses and the air temperature and is remarkable with high correlation coefficient. The conclusions are expected to provide reference for the design and evaluation of longspan suspension bridges.

  6. The Design and Analysis of Long-Span and Low-Depth Prestressed Composite Steel-Concrete Beam Bridge

    Institute of Scientific and Technical Information of China (English)

    张俊平; 黄海云; 黄道沸

    2002-01-01

    The design scheme of long-span and low-depth composite steel-concrete beams is introduced, and the methods of avoiding the cracking of concrete deck in the negative moment regions are proposed. Moreover, significant exploration for problems of the composite beams has been made, such as optimizing construction steps to regulate the stress, applying jacking technique to exert prestress on the concrete deck, investigating the uplifting force principle of the shear connectors by means of model test and non-linear finite element analysis, and pointing out the countermeasure to reduce tension force of the shear connectors.

  7. A major QTL affects temperature sensitive adult lethality and inbreeding depression in life span in Drosophila melanogaster.

    DEFF Research Database (Denmark)

    Vermeulen, Corneel J.; Bijlsma, R.; Loeschcke, Volker

    2008-01-01

    Background The study of inbreeding depression has major relevance for many disciplines, including conservation genetics and evolutionary biology. Still, the molecular genetic basis of this phenomenon remains poorly characterised, as knowledge on the mechanistic causes of inbreeding depression...... and the molecular properties of genes that give rise to or modulate its deleterious effects is lacking. These questions warrant the detailed study of genetic loci giving rise to inbreeding depression. However, the complex and polygenic nature of general inbreeding depression makes this a daunting task. Study...... This demonstrates that analysis of large conditional lethal effects is a viable strategy for delineating genes which are sensitive to inbreeding depression....

  8. Character strengths and well-being across the life span: data from a representative sample of German-speaking adults living in Switzerland.

    Science.gov (United States)

    Martínez-Martí, María L; Ruch, Willibald

    2014-01-01

    Character strengths are positive, morally valued traits of personality. This study aims at assessing the relationship between character strengths and subjective well-being (i.e., life satisfaction, positive and negative affect) in a representative sample of German-speaking adults living in Switzerland (N = 945). We further test whether this relationship is consistent at different stages in life. Results showed that hope, zest, love, social intelligence and perseverance yielded the highest positive correlations with life satisfaction. Hope, zest, humor, gratitude and love presented the highest positive correlations with positive affect. Hope, humor, zest, honesty, and open-mindedness had the highest negative correlations with negative affect. When examining the relationship between strengths and well-being across age groups, in general, hope, zest and humor consistently yielded the highest correlations with well-being. Additionally, in the 27-36 years group, strengths that promote commitment and affiliation (i.e., kindness and honesty) were among the first five positions in the ranking of the relationship between strengths and well-being. In the 37-46 years group, in addition to hope, zest and humor, strengths that promote the maintenance of areas such as family and work (i.e., love, leadership) were among the first five positions in the ranking. Finally, in the 47-57 years group, in addition to hope, zest and humor, strengths that facilitate integration and a vital involvement with the environment (i.e., gratitude, love of learning) were among the first five positions in the ranking. This study partially supports previous findings with less representative samples on the association between character strengths and well-being, and sheds light on the relative importance of some strengths over others for well-being across the life span.

  9. Character strengths and well-being across the life span: Data from a representative sample of German-speaking adults living in Switzerland

    Directory of Open Access Journals (Sweden)

    María Luisa eMartínez Martí

    2014-11-01

    Full Text Available Character strengths are positive, morally valued traits of personality. This study aims at assessing the relationship between character strengths and subjective well-being (i.e., life satisfaction, positive and negative affect in a representative sample of German-speaking adults living in Switzerland (N = 945. We further test whether this relationship is consistent at different stages in life. Results showed that hope, zest, love, social intelligence and perseverance yielded the highest positive correlations with life satisfaction. Hope, zest, humor, gratitude and love presented the highest positive correlations with positive affect. Hope, humor, zest, honesty, and open-mindedness had the highest negative correlations with negative affect. When examining the relationship between strengths and well-being across age groups, in general, hope, zest and humor consistently yielded the highest correlations with well-being. Additionally, in the 27-36 years group, strengths that promote commitment and affiliation (i.e., kindness and honesty were among the first five positions in the ranking of the relationship between strengths and well-being. In the 37-46 years group, in addition to hope, zest and humor, strengths that promote the maintenance of areas such as family and work (i.e., love, leadership were among the first five positions in the ranking. Finally, in the 47-57 years group, in addition to hope, zest and humor, strengths that facilitate integration and a vital involvement with the environment (i.e., gratitude, love of learning were among the first five positions in the ranking. This study partially supports previous findings with less representative samples on the association between character strengths and well-being, and sheds light on the relative importance of some strengths over others for well-being across the life span.

  10. Effects of zinc on the life span and reproductive capacity and the hereditability influence of D.melanogaster%锌对果蝇寿命及生殖力的影响及其可遗传性

    Institute of Scientific and Technical Information of China (English)

    毛雪; 郭欣欣; 张敏

    2012-01-01

    This paper is engaged in the study of zinc effects on the life span and reproduction capability and the hereditability influence of D. melanogaster. As is known, as a trace element, zinc has something to do with the enzyme structure and may act as an enzyme activator or regulator of the endocrine hormone participating in organism metabolism, such as that of protein, amino acid, nucleic acid, fat, carbohydrate, vitamin and other nutritious elements. Laboratory analysis shows that zinc can play an important role in skeletal development, reproduction, immune, biological membrane stability, and functions as a gene denominator, cell proliferator and differentiator. Therefore, zinc deficiency or excess in animal or human bodies may affect their growth, developmenl and reproduction. However, it is not clear how different concentration of zinc would affect the somatic longevity and reproduction capability under the experimental conditions, letting alone make sure if the effect can be hereditary. Therefore, we suggest using the fruit fly (Drosophila melanogaster) to sludy the life span and it? reproduction capability after zinc being treated by survival tests and statistical methods. In doing so, we have added zinc to the culture medium of parental Drosophila at a concentration of 0.026 g/L, 0.052 g/L, 0.104 g/L and 0.260 g/L. Then, the life span and reproduction capability of parental Drosophila after being treated with the first filial Drosophila untreated analyzed separately. The results show that zinc treatment at low concentrations (added to the culture medium at a concentration of 0.026 g/L, 0.052 g/L, 0.104 g/L) tends to extend the average life-span, middle life-span, maximum life-span and 90% lethal time in parental and the first filial Drosophila, with treatment of 0.052 g/L zinc showing the best significant effects. On the contrary, high dosage zinc treatment (0.260 g/L) tends to shorten the life-span of Drosophila significantly, and suppress their reproduction

  11. Face recognition memory across the adult life span: event-related potential evidence from the own-age bias.

    Science.gov (United States)

    Wolff, Nicole; Wiese, Holger; Schweinberger, Stefan R

    2012-12-01

    Young adult participants are more accurate at remembering young as compared with old faces (own-age bias). This study investigated behavioral and event-related potential (ERP) correlates of recognition memory in 4 consecutive age categories (ranging from 19-29, 30-44, 45-59, and 60-80 years), both with respect to face and participant age. Young and young middle-aged participants yielded more accurate recognition memory for both young and young middle-aged as compared to old middle-aged and old faces, suggesting that the own-age bias in adults is not exclusively directed toward age-congruent "in-group" faces. No own-age bias was observed in old middle-aged and elderly participants. Analysis of ERPs revealed significant positive correlations of both N170 latency and amplitude with participant age, thus, suggesting an age-related delay of processing speed and an increase in processing demands at early perceptual stages of face processing. Furthermore, an ERP old-new effect (400-700 ms), with more positive amplitudes for hits as compared with correct rejections, was detected in young and young middle-aged participants but not in the 2 older groups. Because these older groups did not demonstrate enhanced memory performance for own-age faces, we suggest that detailed recollection of study-episode information, as reflected in the ERP old-new effect, may be a necessary prerequisite for the own-age bias.

  12. Corpora lutea of pregnant and pseudopregnant domestic cats reveal similar steroidogenic capacities during the luteal life span.

    Science.gov (United States)

    Zschockelt, Lina; Amelkina, Olga; Siemieniuch, Marta J; Koster, Stefanie; Jewgenow, Katarina; Braun, Beate C

    2014-10-01

    In domestic cats, luteal phases of pregnancy and pseudopregnancy (non-pregnant luteal phase) differ in the course and level of plasma progesterone (P4). Therefore, we assumed differences in luteal steroidogenic capacities. Here we present a comprehensive analysis of intraluteal steroid biogenesis in the domestic cat. We quantitatively measured relative mRNA levels of steroidogenic acute regulatory protein (STAR), cytochrome P450 oxidases (CYP), hydroxysteroid dehydrogenases (HSD), steroid reductase (SRD) and enzymes involved in sulfoconjugation of steroids, i.e. sulfotransferase (SULT) and sulfatase (STS). Protein expression was analysed by Western Blot for HSD3B. Additionally, intraluteal steroid contents were determined. During the pseudopregnant luteal phase, expression of STAR (p=0.005), HSD3B1 (ppregnancy and pseudopregnancy. This was in accordance with decreasing intraluteal levels of P4, oestrogens and androgens. In contrast, expression of SRD5A1 (p0.05), suggesting a permanent capacity of cat CL to convert progestogens via androgen and oestrogen pathways. In general, mRNA expression profiles of steroidogenic enzymes during the pregnant luteal phase reflected the pseudopregnancy profiles. Intraluteal oestrogen (pcat CL of the same histomorphological stage are characterised by identical steroidogenic capacities independently of an on-going pregnancy.

  13. Relationship between anthropometric factors, radiation exposure, and colon cancer incidence in the Life Span Study cohort of atomic bomb survivors.

    Science.gov (United States)

    Semmens, Erin O; Kopecky, Kenneth J; Grant, Eric; Mathes, Robert W; Nishi, Nobuo; Sugiyama, Hiromi; Moriwaki, Hiroko; Sakata, Ritsu; Soda, Midori; Kasagi, Fumiyoshi; Yamada, Michiko; Fujiwara, Saeko; Akahoshi, Masazumi; Davis, Scott; Kodama, Kazunori; Li, Christopher I

    2013-01-01

    We examined colon cancer risk in atomic bomb survivors to investigate whether excess body weight after the bombings alters sensitivity to radiation effects. Of the 56,064 Japanese atomic bomb survivors with follow-up through 2002 with self-reported anthropometric data obtained from periodic mail surveys, 1,142 were diagnosed with colon cancer. We evaluated the influence of body mass index (BMI) and height on radiation-associated colon cancer risk using Poisson regression. We observed a similar linear dose-response relationship for the 56,064 subjects included in our analysis and the entire cohort of Japanese atomic bomb survivors [excess relative risk (ERR) per Gray (Gy) = 0.53, 95 % confidence interval (CI) 0.25-0.86]. Elevation in earliest reported BMI, BMI reported closest to colon cancer diagnosis, and time-varying BMI were associated with an elevated risk of colon cancer [relative risk (RR) per 5 kg/m(2) increase in BMI = 1.14, 95 % CI 1.03-1.26; RR = 1.16, 95 % CI 1.05-1.27; and RR = 1.15, 95 % CI 1.04-1.27, respectively]. Height was not significantly related to colon cancer risk. Inclusion of anthropometric variables in models had little impact on radiation risk estimates, and there was no evidence that sensitivity to the effect of radiation on colon cancer risk depended on BMI. Radiation exposure and BMI are both risk factors for colon cancer. BMI at various times after exposure to the atomic bombings does not significantly influence the relationship between radiation dose and colon cancer risk, suggesting that BMI and radiation impact colon cancer risk independently of each other.

  14. An Aileron Flutter Experiment and Analysis Using Semi-Span Model for the Small Supersonic Experimental Aircraft

    Science.gov (United States)

    Saitoh, Kenichi; Tamayama, Masato; Kikuchi, Takao; Machida, Shigeru; Nakamichi, Jiro

    This paper reports a wind-tunnel experiment and analysis that have been conducted under the National Experimental Airplane for Supersonic Transports (NEXST-1) project of JAXA. In order to perform the flight experiment, the design of the vehicle was examined from the stand point of aeroelasticity. The aileron buzz as well as flutter was of much concern for its aileron system on the main wing. Therefore, both wind-tunnel test and analysis were carried out by using a semi-span model with fuselage. Although the buzz was not observed in the test, damping responses of the aileron rotation mode were obtained. Critical damping was observed in supersonic flow, that meant a buzz could occur in ``region C'' of Lambourne's classification. Linear unsteady aerodynamic analysis is applicable to this type of buzz and the characteristics of the buzz of the model is discussed.

  15. Suicide: Across the Life Span.

    Science.gov (United States)

    Ramirez, Jeffery

    2016-06-01

    Suicide remains a major public health issue. There have been more than 40,000 deaths by suicide in 2014. Understanding both the neuroscience and psychological development is key for nursing care so adequate interventions and treatment strategies are developed when working with people thinking about suicide. It is critical to assess and recognize risk and protective factors to ensure patient safety. The older adult, children, and adolescent populations remain vulnerable to suicide. A discussion regarding the psychiatric, psychosocial, and treatment considerations for these populations is included. An overview of communication, suicide assessment, and safety planning is discussed.

  16. Life span in online communities

    Science.gov (United States)

    Grabowski, A.; Kosiński, R. A.

    2010-12-01

    Recently online communities have attracted great interest and have become an important medium of information exchange between users. The aim of this work is to introduce a simple model of the evolution of online communities. This model describes (a) the time evolution of users’ activity in a web service, e.g., the time evolution of the number of online friends or written posts, (b) the time evolution of the degree distribution of a social network, and (c) the time evolution of the number of active users of a web service. In the second part of the paper we investigate the influence of the users’ lifespan (i.e., the total time in which they are active in an online community) on the process of rumor propagation in evolving social networks. Viral marketing is an important application of such method of information propagation.

  17. Numerical analysis of dynamic response of vehicle–bridge coupled system on long-span continuous girder bridge

    Directory of Open Access Journals (Sweden)

    Lipeng An

    2016-07-01

    Full Text Available To systematically study the vehicle–bridge coupled dynamic response and its change rule with different parameters, a vehicle model with seven degrees of freedom was built and the total potential energy of vehicle space vibration system was deduced. Considering the stimulation of road roughness, the dynamic response equation of vehicle–bridge coupled system was established in accordance with the elastic system principle of total potential energy with stationary value and the “set-in-right-position” rule. On the basis of the self-compiled Fortran program and bridge engineering, the dynamic response of long-span continuous girder bridge under vehicle load was studied. This study also included the calculation of vehicle impact coefficient, evaluation of vibration comfort, and analysis of dynamic response parameters. Results show the impact coefficient changes with lane number and is larger than the value calculated by the “general code for design of highway bridges and culverts (China”. The Dieckmann index of bridge vibration is also related to lane number, and the vibration comfort evaluation is good in normal conditions. The relevant conclusions from parametric analyses have practical significance to dynamic design and daily operation of long-span continuous girder bridges in expressways. Safety and comfort are expected to improve significantly with further control of the vibration of vehicle–bridge system.

  18. Changes in gas exchange characteristics during the life span of giant sequoia: implications for response to current and future concentrations of atmospheric ozone.

    Science.gov (United States)

    Grulke, N. E.; Miller, P. R.

    1994-01-01

    Native stands of giant sequoia (Sequoiadendron giganteum Bucholz) are being exposed to relatively high concentrations of atmospheric ozone produced in urban and agricultural areas upwind. The expected change in environmental conditions over the next 100 years is likely to be unprecedented in the life span (about 2,500 years) of giant sequoia. We determined changes in physiological responses of three age classes of giant sequoia (current-year, 12-, and 125-year-old) to differing concentrations of ozone, and assessed age-related differences in sensitivity to pollutants by examining physiological changes (gas exchange, water use efficiency) across the life span of giant sequoia (current-year, 2-, 5-, 20-, 125-, and > 2,000-year-old trees). The CO(2) exchange rate (CER) was greater in current-year (12.1 micro mol CO(2) m(-2) s(-1)) and 2-year-old seedlings (4.8 micro mol CO(2) m(-2) s(-1)) than in all older trees (3.0 micro mol CO(2) m(-2) s(-1), averaged across the four older age classes). Dark respiration was highest for current-year seedlings (-6.5 +/- 0.7 micro mol CO(2) m(-2) s(-1)) and was increased twofold in symptomatic individuals exposed to elevated ozone concentrations. Stomatal conductance (g(s)) was greater in current-year (355 mmol H(2)O m(-2) s(-1)) and 2-year-old seedlings (200 mmol H(2)O m(-2) s(-1)) than in all older trees (50 mmol H(2)O m(-2) s(-1)), indicating that the ozone concentration in substomatal cavities is higher in young seedlings than in trees. Significant changes in water use efficiency, as indicated by C(i)/C(a), occurred in trees between ages 5 and 20 years. We conclude that giant sequoias seedlings are sensitive to atmospheric ozone until they are about 5 years old. Low conductance, high water use efficiency, and compact mesophyll all contribute to a natural ozone tolerance, or defense, or both, in foliage of older trees.

  19. Phototoxic effect of UVR on wild type, ebony and yellow mutants of Drosophila melanogaster: Life Span, fertility, courtship and biochemical aspects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Melanin plays an important role in protecting organisms from ultraviolet radiation (UVR). Therefore, it is possible that differently colored strains can show different sensitivities to UVR. In the present work, life span, fertility and courtship behavior of wild type (w), ebony (e) and yellow (y) strains of Drosophila melanogaster were studied to evaluate their sensitivity to ultraviolet (UV). Because a range of photo- toxic effects of UVR are mediated through generation of free radicals, levels of free radicals, lipid per- oxide (malondialdehyde, MDA) and superoxide dismutase (SOD) activity of three strains were examined to indicate their antioxidant defending ability and oxidative status. It was shown that w always had the highest lifespan and fertility not only in the control but also in UV-exposed groups. Moreover, lifespan and fertility of e were significantly higher (P<0.0001) than those of y in the UV-exposed groups, but not for the control. On the other hand, UV exposure had an adverse effect on courtship of flies. Stronger electron paramagnetic resonance (EPR) signals could be detected in w, e and y exposed to 5 min UV. And there were more significant changes of EPR signals in y than in w and e. UVR had no significant (P=0.1782) effect on the SOD activities. After pooling data from the control and UV-exposed groups, we found that w had a significantly (P<0.05) higher level of SOD activity, but e and y were nearly at the same levels (P>0.05). MDA levels were increased in the UV dose-dependent manner (P=0.0495). In con- clusion, our results suggested that UVR can decrease life span and fertility of flies and do harm to courtship, which may be due to oxidative damage to flies tissues (e.g. central nervous system) induced by free radicals. w had the highest tolerance to UVR, which may be ascribed to its advantage of survival under the natural condition and at high level of SOD activity. Then differences of pigment between e and y in absorbing UV, shielding

  20. Fatigue Life Analysis of Cantilever Probe on Wafer Test

    Directory of Open Access Journals (Sweden)

    Hsiao Te-Ching

    2016-01-01

    Full Text Available This research utilizes the finite element analysis software (ANSYS to stimulate the different probe material quality (tungsten, SUS304 stainless steel, SUS316L stainless steel and SKD11 tool steel, respectively during wafer tests. Under a room temperature of (25°C, the stress and fatigue life (cycles of probing test of the cantilever probe were measured with an OverDriver (OD of 20µm, 40µm, 50µm, 60µm and 80µm, respectively. First, to obtain the magnitude of pinpoint shift of the probe under wafer test and the OverDriver is 50µm. And, calculate the fatigue life of the probe. Then, a probe model with the same characteristics as the experiment is created and the probe fatigue life analyzed with the ANSYS. After the reliability of the model is ascertained, the wafer tests of different probe materials are stimulated under different OverDriver circumstances to calculate its stress and fatigue life. The results indicate that the greatest stress measured during the wafer test of the tungsten, SUS304 stainless steel, SUS316L stainless steel and SKD11 tool steel cantilever probe are all smaller than the yield strength, and the fatigue life could reach over one hundred K cycles. When catalogued by the cantilever probe fatigue life during one hundred K cycles, the life span, in order, is tungsten < SUS316L stainless steel < SUS304 stainless steel < SKD11 tool steel.

  1. Dynamical mechanism in aero-engine gas path system using minimum spanning tree and detrended cross-correlation analysis

    Science.gov (United States)

    Dong, Keqiang; Zhang, Hong; Gao, You

    2017-01-01

    Identifying the mutual interaction in aero-engine gas path system is a crucial problem that facilitates the understanding of emerging structures in complex system. By employing the multiscale multifractal detrended cross-correlation analysis method to aero-engine gas path system, the cross-correlation characteristics between gas path system parameters are established. Further, we apply multiscale multifractal detrended cross-correlation distance matrix and minimum spanning tree to investigate the mutual interactions of gas path variables. The results can infer that the low-spool rotor speed (N1) and engine pressure ratio (EPR) are main gas path parameters. The application of proposed method contributes to promote our understanding of the internal mechanisms and structures of aero-engine dynamics.

  2. Dynamic Performance Analysis of the Towers of a Long-Span Bridge Based on GPS Monitoring Technique

    Directory of Open Access Journals (Sweden)

    Mosbeh R. Kaloop

    2016-01-01

    Full Text Available The present study investigates the parameter identification and the dynamic performance of a long-span bridge tower based on the output of a global positioning system (GPS health monitoring system. The random decrement (RD algorithm is used to estimate the tower displacement impulse response. Three methods are applied to extract the dynamic performance including least squares complex exponential (LSCE method, Hilbert envelope method (HEM, and eigensystem realization algorithm (ERA. Results reveal that the HEM and LSCE method are more suitable to extract fundamental frequency and modal and damping ratios of the tower. Furthermore, the dynamic properties and statistical time series analysis of the GPS measurements illustrate that the traffic loads have a high significant impact on the semistatic and dynamic performances.

  3. Towards Maximum Spanning Tree Model in Web 3.0 Design and Development for Students using Discriminant Analysis

    Directory of Open Access Journals (Sweden)

    S.Padma

    2011-09-01

    Full Text Available Web 3.0 is an evolving extension of the web 2.0 scenario. The perceptions regarding web 3.0 is different from person to person . Web 3.0 Architecture supports ubiquitous connectivity, network computing, open identity, intelligent web, distributed databases and intelligent applications . Some of the technologies which lead to the design and development of web 3.0 applications are Artificial intelligence, Automated reasoning, Cognitive architecture, Semantic web. An attempt is made to capture the requirements of Students inline with web 3.0 so as to bridge the gap between the design and development of web 3.0 applications and requirements among Students. Maximum Spanning Tree modeling of the requirements facilitate the identification of key areas and key attributes in the design and development of software products for Students in Web 3.0 using Discriminant analysis.

  4. Infantile onset Vanishing White Matter disease associated with a novel EIF2B5 variant, remarkably long life span, severe epilepsy, and hypopituitarism.

    Science.gov (United States)

    Woody, April L; Hsieh, David T; McIver, Harkirtin K; Thomas, Linda P; Rohena, Luis

    2015-04-01

    Vanishing White Matter disease (VWM) is an inherited progressive leukoencephalopathy caused by mutations in the genes EIF2B1-5, which encode for the 5 subunits of the eukaryotic initiation factor 2B (eIF2B), a regulator of protein synthesis. VWM typically presents with acute neurological decline following febrile infections or minor head trauma, and subsequent progressive neurological and cognitive regression. There is a varied clinical spectrum of VWM, with earlier onset associated with more severe phenotypes. Brain magnetic resonance imaging is usually diagnostic with diffusely abnormal white matter, progressing over time to cystic degeneration. We are reporting on a patient with infantile onset VWM associated with three heterozygous missense variants in EIF2B5, including a novel missense variant on exon 6 of EIF2B5 (D262N), as well as an interstitial duplication at 7q21.12. In addition, our case is unusual because of a severe epilepsy course, a novel clinical finding of hypopituitarism manifested by hypothyroidism and adrenal insufficiency, and a prolonged life span with current age of survival of 4 years and 11 months.

  5. 宋代皇子人数及寿命考%A Study on the Number and Life-span of the Princes in Song Dynasty

    Institute of Scientific and Technical Information of China (English)

    范帅

    2015-01-01

    The average life-span of the princes in Song dynasty was comparatively short and almost one third of them prematurely died.Two dominant causes for the death include the humiliation after being captured and the underdeveloped medical technology.Because of the frequent premature death,the contemporary people always introspected and summarized three causes such as religious sacrifices,misdiagnoses,and su-perstitions.Generally,there were more princes with higher survival rate in the North Song dynasty than those in the South Song dynasty.%宋代皇子的平均寿命较低,早亡皇子占皇子总数的近三分之一。宋代皇子寿命短主要有两大原因:一是被俘后屈辱而亡;二为医疗技术不够发达。面对皇子频频早亡,宋人经常自省,并从宗教祭祀、医官误诊和迷信风水三个方面寻找皇子夭折的原因。其中,北宋皇子人数多于南宋,成活率总体也高于南宋。

  6. n-butylidenephthalide treatment prolongs life span and attenuates motor neuron loss in SOD1(G93A) mouse model of amyotrophic lateral sclerosis.

    Science.gov (United States)

    Zhou, Qin-Ming; Zhang, Jing-Jing; Li, Song; Chen, Sheng; Le, Wei-Dong

    2017-05-01

    To evaluate the therapeutic effects of n-butylidenephthalide (BP) in SOD1(G93A) mouse model of amyotrophic lateral sclerosis and explore the possible mechanisms. The SOD1(G93A) mice were treated by oral administration of BP (q.d., 400 mg/kg d) starting from 60 days of age and continuing until death. The rotarod test was performed to assess the disease onset. The expression levels of apoptosis-related proteins, inflammatory molecules, and autophagy-associated proteins were determined. The number of apoptotic motor neurons and the extent of microglial and astroglial activation were also assessed in the lumbar spinal cords of BP-treated mice. Grip strength test, hematoxylin-eosin staining, nicotinamide adenine dinucleotide hydrogen staining, and malondialdehyde assay were conducted to evaluate the muscle function and pathology. Although BP treatment did not delay the disease onset, it prolonged the life span and thereafter extended the disease duration in SOD1(G93A) mouse model of ALS. BP treatment also reduced the motor neuron loss through inhibiting apoptosis. We further demonstrated that the neuroprotective effects of BP might be resulted from the inhibition of inflammatory, oxidative stress, and autophagy. Our study suggests that BP may be a promising candidate for the treatment of ALS. © 2017 John Wiley & Sons Ltd.

  7. Tackling vision-related disability in old age: an application of the life-span theory of control to narrative data.

    Science.gov (United States)

    Boerner, Kathrin; Brennan, Mark; Horowitz, Amy; Reinhardt, Joann P

    2010-01-01

    This study used the life-span theory of control (Heckhausen, J., & Schulz, R.) to examine adaptation to disability in old age. A narrative approach to data collection was used to assess the strategies employed by 364 older adults with macular degeneration to deal with daily challenges. Findings revealed a rich array of strategies. Compensatory Primary Control was reported by nearly all respondents, Compensatory Secondary Control by a majority, and Selective Primary Control by half of the participants. Selective Secondary Control was the least reported. Differences in strategy use depending on level of vision impairment were the most pronounced within the category of Compensatory Primary Control for strategies that involved using help from others and alternative means. Within the category of Selective Secondary Control, effort to maintain a positive outlook was associated with higher impairment levels, whereas within the category of Compensatory Secondary Control, attempts not to dwell on problems related to vision were associated with lower impairment levels. Implications for conceptual development and future research are discussed.

  8. Rapid sexual maturity and short life span in the blue-legged frog and the rainbow frog from the arid Isalo Massif, southern-central Madagascar.

    Science.gov (United States)

    Guarino, Fabio M; Tessa, Giulia; Mercurio, Vincenzo; Andreone, Franco

    2010-12-01

    Longevity and age at sexual maturity were estimated in two anurans from the arid Isalo Massif (southern-central Madagascar), the blue-legged frog (Mantella expectata) and the rainbow frog (Scaphiophryne gottlebei). Phalanges from 69 individuals of M. expectata and 38 individuals of S. gottlebei were analyzed, using the skeletochronological method, in samples collected during two periods: January-February and November-December 2004. The male gonads of both species were also analyzed in order to better correlate reproductive activity with phenology. The phalangeal diaphysis in adults of both species was composed of two concentric bone layers: an innermost endosteal bone, which was less developed or sometimes lacking in S. gottlebei, and an outermost and broader layer of periosteal bone. Lines of arrested growth (LAGs) were observed in both species, although their recognition was more problematic and their distinctiveness much less evident in S. gottlebei. The results presented here indicate that M. expectata and S. gottlebei have a short life span and attain sexual maturity within the first active season after metamorphosis. Maximum longevity was 3 years in M. expectata and 2 years in S. gottlebei. In S. gottlebei the adult body size is likely attained during the same season in which metamorphosis occurs, but then breeding occurs only after the first latency period. Thus, mature individuals have only one LAG, corresponding to 1 year. The low number of individuals with two LAGs suggests that most animals die before the second latency period.

  9. Rho Kinase Inhibitor Y-27632 Prolongs the Life Span of Adult Human Keratinocytes, Enhances Skin Equivalent Development, and Facilitates Lentiviral Transduction

    Science.gov (United States)

    Rodijk-Olthuis, Diana; Jansen, Patrick A.M.; van Vlijmen-Willems, Ivonne M.J.J.; van Erp, Piet E.; Joosten, Irma; Zeeuwen, Patrick L.J.M.

    2012-01-01

    The use of tissue-engineered human skin equivalents (HSE) for fundamental research and industrial application requires the expansion of keratinocytes from a limited number of skin biopsies donated by adult healthy volunteers or patients. A pharmacological inhibitor of Rho-associated protein kinases, Y-27632, was recently reported to immortalize neonatal human foreskin keratinocytes. Here, we investigated the potential use of Y-27632 to expand human adult keratinocytes and evaluated its effects on HSE development and in vitro gene delivery assays. Y-27632 was found to significantly increase the life span of human adult keratinocytes (up to five to eight passages). The epidermal morphology of HSEs generated from high-passage, Y-27632-treated keratinocytes resembled the native epidermis and was improved by supplementing Y-27632 during the submerged phase of HSE development. In addition, Y-27632-treated keratinocytes responded normally to inflammatory stimuli, and could be used to generate HSEs with a psoriatic phenotype, upon stimulation with relevant cytokines. Furthermore, Y-27632 significantly enhanced both lentiviral transduction efficiency of primary adult keratinocytes and epidermal morphology of HSEs generated thereof. Our study indicates that Y-27632 is a potentially powerful tool that is used for a variety of applications of adult human keratinocytes. PMID:22519508

  10. Recruitment and retention strategies for minority or poor clinical research participants: lessons from the Healthy Aging in Neighborhoods of Diversity across the Life Span study.

    Science.gov (United States)

    Ejiogu, Ngozi; Norbeck, Jennifer H; Mason, Marc A; Cromwell, Bridget C; Zonderman, Alan B; Evans, Michele K

    2011-06-01

    Investigating health disparities requires studies designed to recruit and retain racially and socioeconomically diverse cohorts. It is critical to address the barriers that disproportionately affect participation in clinical research by minorities and the socioeconomically disadvantaged. This study sought to identify and rectify these barriers to recruit and retain a biracial (African American and non-Hispanic White) and socioeconomically diverse cohort for a longitudinal study. The Healthy Aging in Neighborhoods of Diversity across the Life Span study is a 20-year longitudinal examination of how race and socioeconomic status influence the development of age-related health disparities. One goal was to create a multifactorial recruitment and retention strategy. The recruitment paradigm targeted known barriers and identified those unique to the study's urban environment. The retention paradigm mirrored the recruitment plan but was based on specifically developed approaches. This cohort recruitment required attention to developing community partnerships, designing the research study to meet the study hypotheses and to provide benefit to participants, providing a safe community-based site for the research and creating didactics to develop staff cultural proficiency. These efforts facilitated study implementation and enhanced recruitment resulting in accrual of a biracial and socioeconomically diverse cohort of 3,722 participants. Recruiting and retaining minority or poor research participants is challenging but possible. The essential facets include clear communication of the research hypothesis, focus on providing a direct benefit for participants, and selection of a hypothesis that is directly relevant to the community studied.

  11. Biomarkers of aging, life span and spontaneous carcinogenesis in the wild type and HER-2 transgenic FVB/N female mice.

    Science.gov (United States)

    Panchenko, Andrey V; Popovich, Irina G; Trashkov, Alexandr P; Egormin, Peter A; Yurova, Maria N; Tyndyk, Margarita L; Gubareva, Ekaterina A; Artyukin, Ilia N; Vasiliev, Andrey G; Khaitsev, Nikolai V; Zabezhinski, Mark A; Anisimov, Vladimir N

    2016-04-01

    FVB/N wild type and transgenic HER-2/neu FVB/N female mice breed at N.N. Petrov Research Institute of Oncology were under observation until natural death without any special treatment. Age-related dynamics of body weight, food consumption and parameters of carbohydrate and lipid metabolism, level of nitric oxide, malonic dialdehyde, catalase, Cu, Zn-superoxide dismutase, vascular endothelial growth factor were studied in both mice strains. The parameters of life span and tumor pathology were studied as well. Cancer-prone transgenic HER-2/neu mice developed in 100 % multiple mammary adenocarcinomas and died before the age of 1 year. Forty tree percent of long-lived wild type mice survived the age of 2 years and 19 %-800 days. The total tumor incidence in wild type mice was 34 %. The age-associated changes in the level of serum IGF-1, glucose and insulin started much earlier in transgene HER-2/neu mice as compared with wild type FVB/N mice. It was suggested that transgenic HER-2/neu involves in initiation of malignization of mammary epithelial cells but also in acceleration of age-related hormonal and metabolic changes in turn promoting mammary carcinogenesis.

  12. Long-term oral administration of the NMDA receptor antagonist memantine extends life span in spinocerebellar ataxia type 1 knock-in mice.

    Science.gov (United States)

    Iizuka, Akira; Nakamura, Kazuhiro; Hirai, Hirokazu

    2015-04-10

    Spinocerebellar ataxia type 1 (SCA1) is a progressive neurodegenerative disease caused by extension of a CAG repeat in the Sca1gene. Although the mechanisms underlying the symptoms of SCA1 have not been determined, aberrant neuronal activation potentially contributes to the neuronal cell death characteristic of the disease. Here we examined the potential involvement of extrasynaptic N-methyl-d-aspartate receptor (NMDAR) activation in the pathogenesis of SCA1 by administering memantine, a low-affinity noncompetitive NMDAR antagonist, in SCA1 knock-in (KI) mice. In KI mice, the exon in the ataxin 1 gene is replaced with abnormally expanded 154CAG repeats. Memantine was administered orally to the SCA1 KI mice from 4 weeks of age until death. The treatment significantly attenuated body-weight loss and prolonged the life span of SCA1 KI mice. Furthermore, memantine significantly suppressed the loss of Purkinje cells in the cerebellum and motor neurons in the dorsal motor nucleus of the vagus, which are critical for motor function and parasympathetic function, respectively. These findings support the contribution of aberrant activation of extrasynaptic NMDARs to neuronal cell death in SCA1 KI mice and suggest that memantine may also have therapeutic benefits in human SCA1 patients.

  13. The control processes and subjective well-being of Chinese teachers: Evidence of convergence with and divergence from the key propositions of the motivational theory of life-span development

    Directory of Open Access Journals (Sweden)

    Wan-Chi eWong

    2014-05-01

    Full Text Available An analytical review of the motivational theory of life-span development reveals that this theory has undergone a series of elegant theoretical integrations. Its claim to universality nonetheless brings forth unresolved controversies. With the purpose of scrutinizing the key propositions of this theory, an empirical study was designed to examine the control processes and subjective well-being of Chinese teachers (N = 637. The OPS-Scales (Optimization in Primary and Secondary Control Scales for the Domain of Teaching were constructed to assess patterns of control processes. Three facets of subjective well-being were investigated with the Positive and Negative Affect Schedule, the Life Satisfaction Scale, and the Subjective Vitality Scale. The results revealed certain aspects of alignment with and certain divergences from the key propositions of the motivational theory of life-span development. Neither primacy of primary control nor primacy of secondary control was clearly supported. Notably, using different criteria for subjective well-being yielded different subtypes of primary and secondary control as predictors. The hypothesized life-span trajectories of primary and secondary control received limited support. To advance the theory in this area, we recommend incorporating Lakatos’ ideas about sophisticated falsification by specifying the hard core of the motivational theory of life-span development and articulating new auxiliary hypotheses.

  14. Ultimate strength analysis of long-span cable-stayed bridges; Chodai chachokyo no shukyoku kyodo kaiseki to kyodo ni kansuru ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Xie, X.; Yamaguchi, H. [Saitama Univ., Urawa (Japan)] Nagai, M. [Nagaoka Technical Coll., Niigata (Japan)

    1998-07-21

    Recently, span of cable-stayed bridges has been getting loner and longer, present situation is that cable-stayed bridges with span 600 to 800m class have been built inside and outside the country, and accurate determination of its ultimate strength has been an important problem statistically. However, concrete design method for evaluating load bearing stress of long-span cable-stayed bridge. Particularly of the main beam whose axial stress is dominating, has not been established so far. As for cable-stayed bridge, even for long-span, effect of plasticization of cross section on ultimate strength is severe because there is little effect of geometric nonlinearity and it is thought that accurate evaluation of ultimate strength only by elastic finite potential analysis is difficult. Accordingly, it is necessary to study the behavior by using combined nonlinear analysis considering the nonlinearity of the material in order to evaluate the safety and economy to long-span cable-stayed bridge. In this report, 3 dimensional analysis method was formularized taking into account the combine nonlinearity of multi-box girder and analysis program of ultimate strength behavior of long-span cable-stayed bridge was developed. 19 refs., 17 figs., 2 tabs.

  15. How could lay perspectives on successful aging complement scientific theory? Findings from a u.s. And a German life-span sample.

    Science.gov (United States)

    Jopp, Daniela S; Wozniak, Dagmara; Damarin, Amanda K; De Feo, Melissa; Jung, Seojung; Jeswani, Sheena

    2015-02-01

    This article investigates lay perspectives of the concept of successful aging in young, middle-aged, and older adults from 2 cultures, the United States and Germany, to potentially guide the development of scientific theories of successful aging. The empirical findings are embedded in a comprehensive overview of theories of successful aging and life-span development and offer implications for theory development. Two samples of young, middle-aged, and older adults from the United States (N = 151) and Germany (N = 155) were asked about definitions and determinants of successful aging. Codes were developed to capture common themes among the answers, resulting in 16 categories. Themes mentioned included resources (health, social), behaviors (activities), and psychological factors (strategies, attitudes/beliefs, well-being, meaning). There were striking similarities across countries, age, and gender. Health and Social Resources were mentioned most frequently, followed by Activities/Interests, Virtues/Attitudes/Beliefs, Well-being, and Life management/Coping. Age differences were limited to Growth/Maturation and Respect/Success, and gender differences were limited to Social Resources and Well-being. Educational and cultural effects were limited to psychological factors and Education/Knowledge, which were more often mentioned by U.S. participants and individuals with more education. Young, middle-aged, and older lay persons from the United States and Germany have quite similar concepts of successful aging, which they view in far more multidimensional terms than do established scientific theories (Rowe & Kahn, 1998). Given evidence that factors mentioned by laypeople do promote successful aging, considering them in more comprehensive theoretical models may enhance our understanding. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

    OpenAIRE

    Yongle Li; Shifu Dong; Yulong Bao; Kejian Chen; Shizhong Qiang

    2015-01-01

    Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehi...

  17. Analysis of the electrochemistry of hemes with Ems spanning 800 mV

    Science.gov (United States)

    Zheng, Zhong; Gunner, M. R.

    2009-01-01

    The free energy of heme reduction in different proteins is found to vary over more than 18 kcal/mol. It is a challenge to determine how proteins manage to achieve this enormous range of Ems with a single type of redox cofactor. Proteins containing 141 unique hemes of a-, b-, and c-type, with bis-His, His-Met, and aquo-His ligation were calculated using Multi-Conformation Continuum Electrostatics (MCCE). The experimental Ems range over 800 mV from −350 mV in cytochrome c3 to 450 mV in cytochrome c peroxidase (vs. SHE). The quantitative analysis of the factors that modulate heme electrochemistry includes the interactions of the heme with its ligands, the solvent, the protein backbone, and sidechains. MCCE calculated Ems are in good agreement with measured values. Using no free parameters the slope of the line comparing calculated and experimental Ems is 0.73 (R2 = 0.90), showing the method accounts for 73% of the observed Em range. Adding a +160 mV correction to the His-Met c-type hemes yields a slope of 0.97 (R2 = 0.93). With the correction 65% of the hemes have an absolute error smaller than 60 mV and 92% are within 120 mV. The overview of heme proteins with known structures and Ems shows both the lowest and highest potential hemes are c-type, whereas the b-type hemes are found in the middle Em range. In solution, bis-His ligation lowers the Em by ≈205 mV relative to hemes with His-Met ligands. The bis-His, aquo-His, and His-Met ligated b-type hemes all cluster about Ems which are ≈200 mV more positive in protein than in water. In contrast, the low potential bis-His c-type hemes are shifted little from in solution, whereas the high potential His-Met c-type hemes are raised by ≈300 mV from solution. The analysis shows that no single type of interaction can be identified as the most important in setting heme electrochemistry in proteins. For example, the loss of solvation (reaction field) energy, which raises the Em, has been suggested to be a major factor in

  18. Pancreatic Cancer in a Northern African Population: A Retrospective Analysis Spanning Two Decades

    Directory of Open Access Journals (Sweden)

    Feriel Sellam

    2008-09-01

    Full Text Available Background Pancreatic cancer has the highest mortality rate of all major cancers. 94% of pancreatic cancer patients will die within five years of diagnosis. Objective To study the epidemiological and pathological characteristics of pancreatic cancer in North African population over a period of twenty two years from 1991 to 2013. Patients and method This was an epidemiological descriptive study conducted in Sidi bel Abbes University Hospital (Western Algeria, Northern Africa. We made a retrospective analysis of records of patients diagnosed with pancreatic cancer and for this purpose the study period was sub-classified into two periods: 1991-2002 and 2003-2013. Results 264 patients aged between 16-96 years were diagnosed with pancreatic cancer; 107 females (40.5% and 157 males (59.5% were recorded between 1991 and 2013; with a sex ratio of 1.46, and age range 16–96 years (median 66.2. Ninety patients (34% were diagnosed with pancreatic cancer during the first period (1991-2002, and 147 patients (66% during the second one (2003 – 2013. A significant association was reported between male patients and their medical histories in the second period (p=0.012; 29% of those patients suffered from diabetes mellitus and 23% from high blood pressure. Another significant correlation was noted between male gender and TNM classification during the first period where p=0.047, mainly at M1 and T4 stages with respectively the rates of 26.3% and 19.3%. Conclusion Pancreatic cancer remains one of the deadliest cancers worldwide and even in developing countries.

  19. Do self-referent metacognition and residential context predict depressive symptoms across late-life span? A developmental study in an Italian sample.

    Science.gov (United States)

    Fastame, Maria Chiara; Hitchcott, Paul Kenneth; Penna, Maria Pietronilla

    2015-01-01

    There is controversial evidence concerning the variables favoring depression in community-dwelling elderly individuals. This study mainly investigates the impact of lifestyle, residential environment, cognitive efficiency and social desirability in predicting self-assessed depressive signs in late adult span. One hundred forty-nine elders were recruited in Northern Italy and Sardinia - an Italian island characterized by the longevity of people living in the inner areas. Participants were presented a battery of questionnaires assessing cognitive efficiency and self-referent measures of depression, metacognition and social desirability. A hierarchical regression analysis showed that residential environment was the most effective predictor of depressive symptoms, along with gardening and spending time for hobbies. In contrast, social desirability and metacognitive scores played a minor role in predicting mental health. An analysis of variance showed that Sardinian elders showed fewer signs of depression than age-matched elders residing in Northern Italy. The Sardinian residential environment is a strong predictor of preserved mental health in late adulthood. In contrast, self-rated metacognitive efficiency and social desirability play a very marginal role in predicting depression among the elderly.

  20. Life cycle cost analysis of commercial buildings with energy efficient approach

    OpenAIRE

    Nilima N. Kale; Deepa Joshi; Radhika Menon

    2016-01-01

    In any construction project, cost effectiveness plays a crucial role. The Life Cycle Cost (LCC) analysis provides a method of determining entire cost of a structure over its expected life along with operational and maintenance cost. LCC can be improved by adopting alternative modern techniques without much alteration in the building. LCC effectiveness can be calculated at various stages of entire span of the building. Moreover this provides decision makers with the financial information neces...

  1. Psychological Well-Being in Italian Families: An Exploratory Approach to the Study of Mental Health Across the Adult Life Span in the Blue Zone

    Directory of Open Access Journals (Sweden)

    Paul Kenneth Hitchcott

    2017-08-01

    Full Text Available Self-reported measures of psychological well-being and depressive symptoms were examined across differently aged family members, while controlling for the impact of marital status and personal satisfaction about family and non-family relations. Twenty-one grandchildren (i.e., ages 21-36 years were recruited with their parents (i.e., 48-66 years old and grandparents (i.e., 75-101 years of age in the ‘blue zone’ of Ogliastra, an Italian area known for the longevity of its inhabitants. Each participant was individually presented a battery of questionnaires assessing their lifestyle and several perceived mental health indices, including the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS, Tennant et al., 2007, and the Center for Epidemiologic Studies Depression Scale (i.e., CES-D, Radloff, 1977. After assessing the level of concordance among adults sharing the same context, the Hierarchical Linear Modeling (HLM approach was used to assess the nested dataset. It was found that family membership (i.e., grandchildren versus parents and grandparents predicted the WEMWBS score but not the CES-D when the impact of marital status and personal satisfaction about social (i.e., family and non-family ties was controlled for. Moreover, two separate repeated-measure Analyses of Variance (ANOVAs documented similar level of personal satisfaction about social relationships across the three family groups. In conclusions, satisfying social ties with friends and family members together with an active socially oriented life style seems to contribute to the promotion of mental health in adult span.

  2. Statistical analysis of life history calendar data.

    Science.gov (United States)

    Eerola, Mervi; Helske, Satu

    2016-04-01

    The life history calendar is a data-collection tool for obtaining reliable retrospective data about life events. To illustrate the analysis of such data, we compare the model-based probabilistic event history analysis and the model-free data mining method, sequence analysis. In event history analysis, we estimate instead of transition hazards the cumulative prediction probabilities of life events in the entire trajectory. In sequence analysis, we compare several dissimilarity metrics and contrast data-driven and user-defined substitution costs. As an example, we study young adults' transition to adulthood as a sequence of events in three life domains. The events define the multistate event history model and the parallel life domains in multidimensional sequence analysis. The relationship between life trajectories and excess depressive symptoms in middle age is further studied by their joint prediction in the multistate model and by regressing the symptom scores on individual-specific cluster indices. The two approaches complement each other in life course analysis; sequence analysis can effectively find typical and atypical life patterns while event history analysis is needed for causal inquiries.

  3. Dynamic analysis and modal test of long-span cable-stayed bridge based on ambient excitation

    Institute of Scientific and Technical Information of China (English)

    CHEN Chang-song; YAN Dong-huang

    2007-01-01

    To study the stifilless distilbution of girder and the method to identify modal parameters of cable-stayed bridge, a simplified dynamical finite element method model named three beams model was established for the girder with double ribs.Based on the simplified model four stiffness formulae were deduced according to Hamilton principle.These formulae reflect well the contribution of the flexural, shearing, free torsion and restricted torsion deformation, respectively.An identification method about modal parameters was put forward by combining method of peak value and power spectral density according to modal test under ambient excitation.The dynamic finite element method analysis and modal test were carried out in a long-span concrete cable-stayed bridge.The results show that the errors of frequencies between theoretical analysis and test results are less than 10%mostly,and the most important modal parameters for cable-stayed bridge are determined to be the longitudinal floating mode, the first vertical flexural mode and the first torsional mode, which demonstrate that the method of stifiness distribution for three beams model is accurate and method to identify modal parameters is effective under ambient excitation modal test.

  4. A Resting-State Brain Functional Network Study in MDD Based on Minimum Spanning Tree Analysis and the Hierarchical Clustering

    Directory of Open Access Journals (Sweden)

    Xiaowei Li

    2017-01-01

    Full Text Available A large number of studies demonstrated that major depressive disorder (MDD is characterized by the alterations in brain functional connections which is also identifiable during the brain’s “resting-state.” But, in the present study, the approach of constructing functional connectivity is often biased by the choice of the threshold. Besides, more attention was paid to the number and length of links in brain networks, and the clustering partitioning of nodes was unclear. Therefore, minimum spanning tree (MST analysis and the hierarchical clustering were first used for the depression disease in this study. Resting-state electroencephalogram (EEG sources were assessed from 15 healthy and 23 major depressive subjects. Then the coherence, MST, and the hierarchical clustering were obtained. In the theta band, coherence analysis showed that the EEG coherence of the MDD patients was significantly higher than that of the healthy controls especially in the left temporal region. The MST results indicated the higher leaf fraction in the depressed group. Compared with the normal group, the major depressive patients lost clustering in frontal regions. Our findings suggested that there was a stronger brain interaction in the MDD group and a left-right functional imbalance in the frontal regions for MDD controls.

  5. Detailed free span assessment for Mexilhao flow lines

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Antonio; Franco, Luciano; Eigbe, Uwa; BomfimSilva, Carlos [INTECSEA, Houston, TX (United States); Escudero, Carlos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The subsea gas production system of Mexilhao Field SPS-35, Santos Basin, offshore Brazil, is composed basically of two rigid 12.75 inches production flow lines approximately 21 km long installed in a fairly rough seabed. During the basic design, the free span assessment was performed considering the maximum allowable free span length determined by the response model proposed by DNV-RP-F105. This approach resulted in a large number of predicted free span requiring corrections, leading to a higher capital cost for the project. In this sense, a detailed free span VIV fatigue assessment was proposed, considering multi-spans and multi-mode effects and also the post lay survey data. The assessment followed the DNV-RP-F105 recommendations for multi-spans and multi-mode effects, using Finite Element Analysis to determine the natural frequencies, mode shapes and corresponding stresses associated with the mode shapes. The assessment was performed in three stages, the first during the detailed design as part of the bottom roughness analysis using the expected residual pipelay tension. The second stage was performed after pipelay, considering the post-lay survey data, where the actual requirements for span correction were determined. Actual pipelay tension was used and seabed soil stiffness adjusted in the model to match the as-laid pipeline profile obtained from the survey data. The first and second stage assessments are seamlessly automated to speed up the evaluation process and allow for quick response in the field, which was important to keep the construction vessel time minimized. The third stage was performed once the corrections of the spans were made and the purpose was to confirm that the new pipeline configuration along the supported spans had sufficient fatigue life for the temporary and operational phases. For the assessment of all three stages, the probability of occurrence and directionality of the near bottom current was considered to improve prediction of the

  6. Analysis on influence of seismic travelling wave effect on semi-active control for long-span rigid-continuous bridge

    Institute of Scientific and Technical Information of China (English)

    QI Xing-jun; LI Xiao-jun; ZHOU Guo-liang

    2006-01-01

    The analysis approach of semi-active control for long-span rigid-continuous bridge under seismic travelling wave input is established. Magnetorheological dampers are set on the positions of the bridge bearings. The semi-active control calculation and analysis are performed for a five-span rigid-continuous bridge under seismic travelling waves with different apparent surface velocities. The results indicate that travelling wave effect remarkably influences the uncontrolled seismic responses, the semi-active control seismic responses and vibration control effects for the long-span rigid-continuous bridge. It is disadvantageous to the responses of the beams and the piers under the travelling wave input with lower apparent surface velocity, and travelling wave effect can decrease the vibration control effects evidently. Therefore, the travelling wave effect should be considered for the selection of the parameter values of semi-active control system in order to get the designing control effect.

  7. Ways of life analysis and food culture

    DEFF Research Database (Denmark)

    Land, Birgit

    Executive Summary 1. People's food patterns are among other things influenced by their social environments. Analysing the relationship between the social environment and food culture is an important lead in trying to derive consumer objectives directed towards the food sector. 2. The way of life...... typology proposed by Højrup may be a useful device for analysing how the social environment impacts food patterns. Højrup proposes three ways of life: the independent way of life, the wage-earner way of life, and the career-bound way of life. He relates these types to empirical observation by qualitative...... applied to large-scale social changes which affect everyday life. Work by Ziehe, which describes such changes by the processes of technocratization and destruction of tradition, is invoked to supplement way of life analysis....

  8. Life-Cycle Cost-Benefit Analysis

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    2010-01-01

    The future use of Life-Cycle Cost-Benefit (LCCB) analysis is discussed in this paper. A more complete analysis including not only the traditional factors and user costs, but also factors which are difficult to include in the analysis is needed in the future.......The future use of Life-Cycle Cost-Benefit (LCCB) analysis is discussed in this paper. A more complete analysis including not only the traditional factors and user costs, but also factors which are difficult to include in the analysis is needed in the future....

  9. Spanning Tree Problem

    Directory of Open Access Journals (Sweden)

    Yen Hung Chen

    2012-01-01

    minimum cost spanning tree T in G such that the total weight in T is at most a given bound B. In this paper, we present two polynomial time approximation schemes (PTASs for the constrained minimum spanning tree problem.

  10. Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

    Full Text Available Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehicle-bridge system are calculated. The impact effects on main girder, stayed cable, bearings, and bridge tower are discussed at various vehicle speeds. The results show that different components of the long-span railway cable-stayed bridge have different impact coefficients. Even for each part, the impact coefficient is also different at different local positions. It reveals that the impact coefficients in the actual situation may have significant differences with the related code clauses in the present design codes.

  11. The Relation between Big Five Traits and Well-being across the Life Span%不同年龄群体大五人格与幸福感关系

    Institute of Scientific and Technical Information of China (English)

    陈志霞; 李启明

    2014-01-01

    以毕生发展为研究视角,调查了3192位不同年龄群体被试,探讨不同年龄群体大五人格与幸福感的关系。结果发现:(1)各变量都存在显著的年龄效应,大五人格与主观幸福感相关显著;(2)在不同年龄群体里,神经质和开放性都能显著预测主观幸福感,且预测值随着年龄而增大,而外倾性、尽责性和宜人性对主观幸福感的预测存在年龄差异;(3)大五人格对主观幸福感的解释率随着年龄的增长而下降,到60岁之后其解释率上升;(4)年龄在大五人格与主观幸福感之间起了显著的调节作用。%In the current study, we examine the relationship between personality traits and subjective well-being and psy-chological well-being from a life span perspective.A total of 3192 Chinese residents took part in this study from 41 cities in the country 17 provinces and municipalities.And they completed the subjective well-being scale and big five-factor inventory.It took about 20 minutes to complete the questionnaires.The correlations among factors were calculated with SPSS 16.0 and Structural equation model was applied to deal with all data.In the analysis of struc-tural equation modeling, seven models were constructed.As predicted, personality traits were significantly associat-ed with subjective well-being with the different age groups of Chinese residents.And then Structural equation mod-els revealed that ages play a moderating role between personality traits and subjective well-being, and the total effect value was different.In conclusion, this research indicates that personality traits were associated with greater happiness across the life span, and personality traits were one of the best predictors.This study provides new in-sights into personal traits as predictors of well-being.Especially, this study addressed some limitations of previous studies.Importantly, this study also helps clarify questions about

  12. Comparative analysis of life insurance market

    Directory of Open Access Journals (Sweden)

    Malynych, Anna Mykolayivna

    2011-05-01

    Full Text Available The article deals with the comprehensive analysis of statistic insight into development of the world and regional life insurance markets on the basis of macroeconomic indicators. The author located domestic life insurance market on the global scale, analyzed its development and suggested the methods to calculate the marketing life insurance index. There was also approbated the mentioned methods on database of 77 countries all over the world. The author also defined the national rating on the basis of marketing life insurance index.

  13. State, Culture and Life-modes. The foundations of Life-mode analysis

    DEFF Research Database (Denmark)

    Højrup, Thomas

    livsformsanalyse, statsteori, life-mode analysis, statsforms, dialectics, philosophy, war, culture......livsformsanalyse, statsteori, life-mode analysis, statsforms, dialectics, philosophy, war, culture...

  14. TSG (2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside from the Chinese Herb Polygonum multiflorum Increases Life Span and Stress Resistance of Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Christian Büchter

    2015-01-01

    Full Text Available 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG was isolated from Polygonum multiflorum, a plant which is traditionally used as an anti-ageing drug. We have analysed ageing-related effects of TSG in the model organism C. elegans in comparison to resveratrol. TSG exerted a high antioxidative capacity both in a cell-free assay and in the nematode. The antioxidative capacity was even higher compared to resveratrol. Presumably due to its antioxidative effects, treatment with TSG decreased the juglone-mediated induction of the antioxidative enzyme SOD-3; the induction of the GST-4 by juglone was diminished slightly. TSG increased the resistance of C. elegans against lethal thermal stress more prominently than resveratrol (50 μM TSG increased mean survival by 22.2%. The level of the ageing pigment lipofuscin was decreased after incubation with the compound. TSG prolongs the mean, median, and maximum adult life span of C. elegans by 23.5%, 29.4%, and 7.2%, respectively, comparable to the effects of resveratrol. TSG-mediated extension of life span was not abolished in a DAF-16 loss-of-function mutant strain showing that this ageing-related transcription factor is not involved in the effects of TSG. Our data show that TSG possesses a potent antioxidative capacity, enhances the stress resistance, and increases the life span of the nematode C. elegans.

  15. Life-cycle analysis of product integrated polymer solar cells

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; García-Valverde, Rafael; Krebs, Frederik C

    2011-01-01

    economics through design to functionality. An LCA study was performed to quantify the energy use and greenhouse gas (GHG) emissions from electricity use in the manufacture of a light-weight lamp based on a plastic foil, a lithium-polymer battery, a polymer solar cell, printed circuitry, blocking diode......A life cycle analysis (LCA) on a product integrated polymer solar module is carried out in this study. These assessments are well-known to be useful in developmental stages of a product in order to identify the bottlenecks for the up-scaling in its production phase for several aspects spanning from...... on the complete product integrated polymer solar cell. We have compared this portable lighting system with other lighting solutions, namely: a kerosene lamp in a remote rural area in Africa (Ethiopia), as a replacement of a silicon PV based lamp, in place of a torch with non-rechargeable lead-acid battery...

  16. Multistate analysis of life histories with R

    CERN Document Server

    Willekens, Frans

    2014-01-01

    This book provides an introduction to multistate event history analysis. It is an extension of survival analysis, in which a single terminal event (endpoint) is considered and the time-to-event is studied. Multistate models focus on life histories or trajectories, conceptualized as sequences of states and sequences of transitions between states. Life histories are modeled as realizations of continuous-time Markov processes. The model parameters, transition rates, are estimated from data on event counts and populations at risk, using the statistical theory of counting processes. The Comprehensive R Network Archive (CRAN) includes several packages for multistate modeling. This book is about Biograph. The package is designed to (a) enhance exploratory analysis of life histories and (b) make multistate modeling accessible. The package incorporates utilities that connect to several packages for multistate modeling, including survival, eha, Epi, mvna, etm, mstate, msm, and TraMineR for sequence analysis. The book ...

  17. Theoretical analysis and numerical simulation on behaviour properties of large span cable-supported structures under fire conditions

    Institute of Scientific and Technical Information of China (English)

    BAI Yin; SHI YongJiu; WANG YuanQing

    2009-01-01

    Large span cable-supported structures have been developed rapidly in China,and they always adopt high-strength steel cables as structural members.However,the modulus of elasticity and yield strength of steel material will decrease seriously under fire conditions while fire protection is unlikely to be provided for steel cable.Several typical large span cable-supported structures such as cable truss,beam string structure and prestressed cable net are studied on their structural behaviour in this paper.Theoretical formulae are derived in terms of geometrical and material nonlinearity with high temperature effect.Finite element models are also established to simulate the structural performance under fire conditions.The calculation formulae for fire-resisting design are suggested for these three types of structures,while displacement and prestressed force variation rules are also given.

  18. Theoretical analysis and numerical simulation on behaviour properties of large span cable-supported structures under fire conditions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Large span cable-supported structures have been developed rapidly in China, and they always adopt high-strength steel cables as structural members. However, the modulus of elasticity and yield strength of steel material will decrease seriously under fire conditions while fire protection is unlikely to be provided for steel cable. Several typical large span cable-supported structures such as cable truss, beam string structure and prestressed cable net are studied on their structural behaviour in this paper. Theoretical formulae are derived in terms of geometrical and material nonlinearity with high temperature effect. Finite element models are also established to simulate the structural performance under fire conditions. The calculation formulae for fire-resisting design are suggested for these three types of structures, while displacement and prestressed force variation rules are also given.

  19. Fuel cell hybrid taxi life cycle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Patricia, E-mail: patricia.baptista@ist.utl.pt [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ribau, Joao; Bravo, Joao; Silva, Carla [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Adcock, Paul; Kells, Ashley [Intelligent Energy, Charnwood Building, HolywellPark, Ashby Road, Loughborough, LE11 3GR (United Kingdom)

    2011-09-15

    A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO{sub 2} emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO{sub 2} emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: > A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. > The hydrogen powered vehicles have the lowest energy consumption and CO{sub 2} emissions results. > A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

  20. MECHANICAL ANALYSIS OF TSUNAMI WAVE ON SPANNING SUBMARINE PIPELINES%海啸波对海底悬跨管道受力分析

    Institute of Scientific and Technical Information of China (English)

    薛景宏; 王欣; 周禹鑫; 杜厚臣

    2012-01-01

    Currently the mechanical analysis of spanning submarine pipelines has been an important research topic in the development of marine resources. In this paper, research is the impact of the pipeline when the tsunami shift through theregion spanning submarine pipelines. Assuming both ends of the suspended pipe from the impact of the earthquake and tsunami and the tsunami wave is long-wave, based on the traditional Morison equation, calculated the force of de spanning submarine pipelines when the tsunami wave moving through it, modeling and analysis it with the finite element software ADINA. Determine the devastating effect whether worked on the submarine pipelines by analysis the results of simulation for the tsunami waves walk through the spanning submarine pipelines.%研究地震海啸行移时通过海底悬跨管段区域时对管道的影响.假设悬跨段两端不受地震海啸影响,因为海啸为长波,本文根据传统Morison方程计算了海底悬跨管道在行移的海啸波浪荷载作用下的受力情况,并应用有限元软件ADINA进行了建模分析,通过模拟结果分析海啸波浪对海底悬跨管道受力的影响并判断是否会对海底管道造成破坏性影响.

  1. Communicating employability enchancement throughout the life-span: a national intervention program aimed at combating age-related stereotypes at the workplace

    NARCIS (Netherlands)

    M. van Selm; B.I.J.M. van der Heijden

    2013-01-01

    The stimulation of lifelong employability of employees is one of today's challenges in all sectors of the Dutch society. In this article, we will outline the historical context of the life-long employability issue in the Netherlands, and provide an overview of current business responses to the issue

  2. Communicating Employability Enhancement Throughout the Life-Span: A National Intervention Program Aimed at Combating Age-Related Stereotypes at the Workplace

    NARCIS (Netherlands)

    Selm, van Martine; Heijden, van der B.I.J.M.

    2013-01-01

    The stimulation of lifelong employability of employees is one of today's challenges in all sectors of the Dutch society. In this article, we will outline the historical context of the life-long employability issue in the Netherlands, and provide an overview of current business responses to the issue

  3. Insulin-like growth factor-I extends in vitro replicative life span of skeletal muscle satellite cells by enhancing G1/S cell cycle progression via the activation of phosphatidylinositol 3'-kinase/Akt signaling pathway

    Science.gov (United States)

    Chakravarthy, M. V.; Abraha, T. W.; Schwartz, R. J.; Fiorotto, M. L.; Booth, F. W.

    2000-01-01

    Interest is growing in methods to extend replicative life span of non-immortalized stem cells. Using the insulin-like growth factor I (IGF-I) transgenic mouse in which the IGF-I transgene is expressed during skeletal muscle development and maturation prior to isolation and during culture of satellite cells (the myogenic stem cells of mature skeletal muscle fibers) as a model system, we elucidated the underlying molecular mechanisms of IGF-I-mediated enhancement of proliferative potential of these cells. Satellite cells from IGF-I transgenic muscles achieved at least five additional population doublings above the maximum that was attained by wild type satellite cells. This IGF-I-induced increase in proliferative potential was mediated via activation of the phosphatidylinositol 3'-kinase/Akt pathway, independent of mitogen-activated protein kinase activity, facilitating G(1)/S cell cycle progression via a down-regulation of p27(Kip1). Adenovirally mediated ectopic overexpression of p27(Kip1) in exponentially growing IGF-I transgenic satellite cells reversed the increase in cyclin E-cdk2 kinase activity, pRb phosphorylation, and cyclin A protein abundance, thereby implicating an important role for p27(Kip1) in promoting satellite cell senescence. These observations provide a more complete dissection of molecular events by which increased local expression of a growth factor in mature skeletal muscle fibers extends replicative life span of primary stem cells than previously known.

  4. A stockpile of ova in the grass frog Rana temporaria is established once for the life span. Do ovaries in amphibians and in mammals follow the same evolutionary strategy?

    Science.gov (United States)

    Ogielska, Maria; Kotusz, Agnieszka; Augustyńska, Renata; Ihnatowicz, Jerzy; Paśko, Łukasz

    2013-04-01

    Most anuran amphibians produce high numbers of eggs during several consecutive breeding seasons. The question is still open whether oocytes are formed anew as a result of oogonial proliferation after each spawning or the definitive pool of oocytes is established during the juvenile period and is sufficient for the whole reproductive life span of a female. Our quantitative studies show that primary oogonia in adult female frogs can proliferate, but they fail to differentiate further and do not enter meiosis, and thereby there is no supplementation of new generations of oocytes after each spawning. Ovaries of one-year-old grass frogs contain (median) 53,447 diplotene oocytes, in two-years-old frogs this number decreased to 33,583 and eventually reached 25,679 in virgin mature females. More than 50% decrease in the total oocyte number was accompanied by massive degeneration (atresia) of oocytes. The final number of oocytes in a female forms a stock for 11-12 breeding seasons and exceeds the number of eggs produced during the potential reproductive life span of this species. The phylogenetic context of oocyte recruitment modes in the major clades of vertebrates is discussed in respect to their ability to replenish the stock (a renewable stock in ovaries named "open" vs. a non-renewable stock in ovaries named "closed"). Copyright © 2013 Wiley Periodicals, Inc.

  5. The influence of the hot water extract from shiitake medicinal mushroom, Lentinus edodes (higher Basidiomycetes) on the food intake, life span, and age-related locomotor activity of Drosophila melanogaster.

    Science.gov (United States)

    Matjuskova, Natalya; Azena, Elena; Serstnova, Ksenija; Muiznieks, Indrikis

    2014-01-01

    Shiitake medicinal mushroom, Lentinus edodes, is among the most widely cultivated edible mushrooms in the world and is a well-studied source of nutrients and biologically active compounds. We have studied the influence of the dietary supplement of the polysaccharides containing a hot water extract of the mushroom L. edodes on the fruit fly Drosophila melanogaster in terms of food intake, body weight, life span, and age-related locomotor activity. L. edodes extract, when added to the D. melanogaster feeding substrate at a 0.003-0.030% concentration (calculated for the dry weight of the polysaccharide fraction) did not influence food intake or body weight of the flies. It increased the life span and locomotor activities of male flies but was associated with early mortality and decreased locomotor activity of female flies. We conclude that the observed anti-aging effects of L. edodes extracts in the male D. melanogaster are not the result of dietary restriction. We propose that D. melanogaster is a suitable model organism for researching the molecular basis of the anti-aging effect of the shiitake mushroom extracts and sex linkage of these effects.

  6. Insulin-like growth factor-I extends in vitro replicative life span of skeletal muscle satellite cells by enhancing G1/S cell cycle progression via the activation of phosphatidylinositol 3'-kinase/Akt signaling pathway

    Science.gov (United States)

    Chakravarthy, M. V.; Abraha, T. W.; Schwartz, R. J.; Fiorotto, M. L.; Booth, F. W.

    2000-01-01

    Interest is growing in methods to extend replicative life span of non-immortalized stem cells. Using the insulin-like growth factor I (IGF-I) transgenic mouse in which the IGF-I transgene is expressed during skeletal muscle development and maturation prior to isolation and during culture of satellite cells (the myogenic stem cells of mature skeletal muscle fibers) as a model system, we elucidated the underlying molecular mechanisms of IGF-I-mediated enhancement of proliferative potential of these cells. Satellite cells from IGF-I transgenic muscles achieved at least five additional population doublings above the maximum that was attained by wild type satellite cells. This IGF-I-induced increase in proliferative potential was mediated via activation of the phosphatidylinositol 3'-kinase/Akt pathway, independent of mitogen-activated protein kinase activity, facilitating G(1)/S cell cycle progression via a down-regulation of p27(Kip1). Adenovirally mediated ectopic overexpression of p27(Kip1) in exponentially growing IGF-I transgenic satellite cells reversed the increase in cyclin E-cdk2 kinase activity, pRb phosphorylation, and cyclin A protein abundance, thereby implicating an important role for p27(Kip1) in promoting satellite cell senescence. These observations provide a more complete dissection of molecular events by which increased local expression of a growth factor in mature skeletal muscle fibers extends replicative life span of primary stem cells than previously known.

  7. LIFE CYCLE COST ANALYSIS OF SOLAR PONDS

    Directory of Open Access Journals (Sweden)

    Murat ÖZTÜRK

    2008-03-01

    Full Text Available Solar ponds are the systems which collect solar energy and store it for long periods of time. For effective and efficient use of these systems in the country, concepts relating economy of solar ponds which generated hot water from the sun must be known besides their physical properties. Life cycle cost analysis is a systematic analytical method that helps identify and evaluate the environmental impacts of a specific process or competing processes. In order to quantify the costs, resource consumption, and energy use, material and energy balances are performed in a cradle-to-grave manner on the operations required to transform raw materials into useful products. In this study; life cycle cost analysis of reflecting covered and non covered solar ponds are calculated for a volume of 3.5x3.5x2 cubic meters and presented. Also the energies extractable for these solar ponds in Goller Region climatic conditions are given.

  8. Tools for Life Support Systems Analysis

    Science.gov (United States)

    Lange, K.; Ewert, M.

    An analysis of the optimum level of closure of a life support system is a complex task involving hundreds, if not thousands, of parameters. In the absence of complete data on candidate technologies and a complete definition of the mission architecture and requirements, many assumptions are necessary. Because of the large number of parameters, it is difficult to fully comprehend and compare studies performed by different analysts. The Systems Integration, Modeling, and Analysis (SIMA) Project Element within NASA's Advanced Life Support (ALS) Project has taken measures to improve this situation by issuing documents that define ALS requirements, baseline assumptions, and reference missions. As a further step to capture and retain available knowledge and to facilitate system-level studies, various software tools are being developed. These include a database tool for storing, organizing, and updating technology parameters, modeling tools for evaluating time-average and dynamic system performance, and sizing tools for estimating overall system mass, volume, power, cooling, logistics, and crew time. This presentation describes ongoing work on the development and integration of these tools for life support systems analysis.

  9. Deep sea minerals prolong life span of streptozotocin-induced diabetic rats by compensatory augmentation of the IGF-I-survival signaling and inhibition of apoptosis.

    Science.gov (United States)

    Liao, Hung-En; Shibu, Marthandam Asokan; Kuo, Wei-Wen; Pai, Pei-Ying; Ho, Tsung-Jung; Kuo, Chia-Hua; Lin, Jing-Ying; Wen, Su-Ying; Viswanadha, Vijaya Padma; Huang, Chih-Yang

    2016-07-01

    Consumption of deep sea minerals (DSM), such as magnesium, calcium, and potassium, is known to reduce hypercholesterolemia-induced myocardial hypertrophy and cardiac-apoptosis and provide protection against cardiovascular diseases. Heart diseases develop as a lethal complication among diabetic patients usually due to hyperglycemia-induced cardiac-apoptosis that causes severe cardiac-damages, heart failure, and reduced life expectancy. In this study, we investigated the potential of DSM and its related cardio-protection to increase the life expectancy in diabetic rats. In this study, a heart failure rat model was developed by using streptozotocin (65 mg kg(-1) ) IP injection. Different doses of DSM-1× (37 mg kg(-1) day(-1) ), 2× (74 mg kg(-1) day(-1) ) and 3× (111 mg kg(-1) day(-1) ), were administered to the rats through gavages for 4 weeks. The positive effects of DSM on the survival rate of diabetes rats were determined with respect to the corresponding effects of MgSO4 . Further, to understand the mechanism by which DSM enhances the survival of diabetic rats, their potential to regulate cardiac-apoptosis and control cardiac-dysfunction were examined. Echocardiogram, tissue staining, TUNEL assay, and Western blotting assay were used to investigate modulations in the myocardial contractile function and related signaling protein expression. The results showed that DSM regulate apoptosis and complement the cardiomyocyte proliferation by enhancing survival mechanisms. Moreover DSM significantly reduced the mortality rate and enhanced the survival rate of diabetic rats. Experimental results show that DSM administration can be an effective strategy to improve the life expectancy of diabetic subjects by improving cardiac-cell proliferation and by controlling cardiac-apoptosis and associated cardiac-dysfunction. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 769-781, 2016.

  10. 直链烷基苯磺酸钠对黑腹果蝇生殖能力及寿命的影响%Effect of linear alkylbenzenesulfonate on the reproductive capacity and life-span of drosophila melanogaster

    Institute of Scientific and Technical Information of China (English)

    赵文红; 张鼎; 周纯先; 江城梅

    2011-01-01

    Objective To investigate the effect of linear alkylbenzenesulfonate (LAS) on the reproductive capacity and life-span of drosophila melanogaster. Methods Drosophila melanogaster imagoes within 8 h after eclosion were collected with ether anesthesia. The female and male of similar size and normal shape and behavior were selected. The drosophila melanogasters were cultured in the culture medium containing LAS of different densities. We divided the drosophila melanogaster into 4 groups according to LAS concentrations: a low dose group with LAS 150 mg/kg, a middle dose group with LAS 300 mg/kg, a high dose group with LAS 600 mg/kg, and a control group without LAS, respectively. The changes of the reproductive capacity, median lethal time, mean lifespan and max mean life-span of drosophila melanogaster with different doses of LAS were measured and compared with those of the control. Results The pupa numbers of filial generation of drosophila melanogaster in the low, middle,and high dose groups (85.07% ,84.59% and 71.88%, respectively) were lower than those in the control group (P <0.01 ). The median lethal time, mean lifespan and max mean life-span of drosophila melanogaster in the low, middle, and high dose groups were shorter than those in the control group ( P < 0.05 ). The change of life-span of drosophila melanogaster in the high dose group was remarkable: the median lethal time of female and male shortened 13 days and 15 days, the mean life-span of female and male shortened 18 days and 14 days,and the max mean life-span of female and male shortened 14 days and 12 days, respectively. Conclusion LAS has definite toxicity to drosophila melanogaste, which can degrade the reproductive capacity of drosophila melanogaste and shorten the life-span of drosophila melanogaste.%目的:探讨直链烷基苯磺酸钠(linear alkylbenzenesulfonate,LAS)对果蝇生殖能力及寿命的影响.方法:采用乙醚麻醉的方法,收集8 h内羽化而未交配的野生型黑

  11. 腐蚀海底管线悬跨段的地震响应分析%THE SEISMIC RESPONSE ANALYSIS OF CORROSIVE SUBMARINE PIPELINE SUSPENDED SPAN SEGMENT

    Institute of Scientific and Technical Information of China (English)

    孙丽; 张新收; 张美真

    2013-01-01

    由于海底管线会因为各种各样的原因出现悬跨段,悬跨段的受力较为复杂,包括海流和波浪的水动力、管线内压、温度以及地震荷载和其他一些突发荷载等,所以需要加强对管线悬跨管段的动力响应研究.另外现役的海底管线有很多已达到了其设计正常使用年限,出现了不同程度的问题,而腐蚀是导致管线损坏的主要原因.目前对完好管线悬跨段的研究已进行了很长一段时间,而关于腐蚀管线悬跨段的研究还较少,针对这种情况,该文对完好海底管线悬跨段进行了试验和有限元分析,分析表明:试验和模拟得到的基频和加速度放大系数沿轴线的变化趋势一致,ABAQUS能够准确地模拟悬跨管线的地震响应问题.同时,对腐蚀管线悬跨段的固有频率、加速度放大系数和最大加速度沿轴线的变化规律进行了有限元分析.研究表明:腐蚀位置、腐蚀厚度、腐蚀长度和腐蚀宽度对上述方面都会产生不同的影响,且腐蚀宽度的变化对管线动力响应影响最大.%A submarine pipeline would appear suspended span segments because its complex stress states such as the action of water currents and waves,pipeline pressure,temperature,seismic loading and other sudden loads.This is why its dynamic response analysis should be strengthened.At the same time,there are many submarine pipelines,which are working right now,and they had reached their design working lives.This kind of submarine pipeline might have many problems.The main reason leading to pipeline damage is the corrosion.At present,the researches about the intact pipeline suspended span segments have been studied for a long time,while there is little analysis for corroded pipeline suspended span segments.According to the research status,the experiment and finite element analysis of intact submarine pipeline suspended span segment are performed.The analyses show that the variation trends of the

  12. Extreme depletion of PIP3 accompanies the increased life span and stress tolerance of PI3K-null C. elegans mutants

    Directory of Open Access Journals (Sweden)

    Puneet eBharill

    2013-03-01

    Full Text Available The regulation of animal longevity shows remarkable plasticity, in that a variety of genetic lesions are able to extend lifespan by as much as tenfold. Such studies have implicated several key signaling pathways that must normally limit longevity, since their disruption prolongs life. Little is known, however, about the proximal effectors of aging on which these pathways are presumed to converge, and to date, no pharmacologic agents even approach the life-extending effects of genetic mutation. In the present study, we have sought to define the downstream consequences of age-1 nonsense mutations, which confer 10-fold life extension to the nematode C. elegans ― the largest effect documented for any single mutation. Such mutations insert a premature stop codon upstream of the catalytic domain of the AGE-1/ p110α subunit of class-I PI3K. As expected, we do not detect class-I PI3K (and based on our sensitivity, it constitutes <14% of wild-type levels, nor do we find any PI3K activity as judged by immunodetection of phosphorylated AKT, which strongly requires PIP3 for activation by upstream kinases, or immunodetection of its product, PIP3. In the latter case, the upper 95%-confidence limit for PIP3 is 1.4% of the wild-type level. We tested a variety of commercially available PI3K inhibitors, as well as three phosphatidylinositol analogues (PIAs that are most active in inhibiting AKT activation, for effects on longevity and survival of oxidative stress. Of these, GDC-0941, PIA6 and PIA24 (each at 1 or 10 μM extended lifespan by 7–14%, while PIAs 6, 12 and 24 (at 1 or 10 μM increased survival time in 5-mM peroxide by 12–52%.These effects may have been conferred by insulinlike signaling, since a reporter regulated by the DAF-16/FOXO transcription factor, SOD3::GFP, was stimulated by these PIAs in the same rank order (PIA24>PIA6>PIA12 as lifespan. A second reporter, PEPCK::GFP, was equally activated (~40% by all three.

  13. Dual boundary spanning

    DEFF Research Database (Denmark)

    Li-Ying, Jason

    2016-01-01

    The extant literature runs short in understanding openness of innovation regarding and the different pathways along which internal and external knowledge resources can be combined. This study proposes a unique typology for outside-in innovations based on two distinct ways of boundary spanning: wh...

  14. 'The brain is the organ of longevity': Introduction to G. A. Sacher's free-energy hypothesis of life-span enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Justesen, D.R.

    1981-10-01

    No experiment reported to date constitutes an adequate test in the sense of supplying comprehensive information on survival time, metabolic rate, food consumption and utilization, body mass, anatomical integrity (especially that of the skeletal and nervous systems), status of the immune and endocrine systems, and physiological and behavioral competence in the wake of chronic exposure to a moderately thermalizing radio field. Some reports do provide data on one or more of the important end points, usually in association with a single exposure or a limited number of brief exposures. One must distinguish between prolongation of life in senescence and enhancement of longevity based on actual retardation of the rate of aging. More, retardation of aging, if sorely taxed at the expense of quality of living, is no bargain. Some hibernators live relatively long lives, but the torpor of hibernation--a prolonged period of somnolence and greatly reduced metabolic activity--is hardly the stuff of a vibrant psychological existence.

  15. 火麻仁油及甾醇对家蚕寿命影响的观察%Observation of Influence of Semen Cannabis Oil and Sterol on Bombyx Mori Linnaeus Life-span

    Institute of Scientific and Technical Information of China (English)

    李寒冰; 孙静雅; 马永洁; 李根林; 任慧玲

    2012-01-01

    目的:观察火麻仁油及火麻仁甾醇对家蚕寿命的影响,探讨火麻仁油及甾醇的抗衰老作用.方法:取龄期相同、生长整齐的三眠蚕随机分为8组,即空白对照组,火麻仁油高、中、低剂量组,火麻仁甾醇高、中、低剂量组,维生素E对照组,每组110条.使用涂抹法将药液涂抹于新鲜桑叶上,4龄期内喂食3次,5龄期内喂食6次.结果:火麻仁油及甾醇高、中、低剂量组均对家蚕幼虫生存期较空白对照组明显延长(P<0.01或P<0.05),其中火麻仁甾醇能显著延长家蚕全生存期(P<0.01或P<0.05).与空白组相比,火麻仁油及甾醇均能显著延长5龄期家蚕耐饥饿时间(P<0.01).结论:火麻仁油及甾醇均能够延长家香各龄期生存期时间.%Objective:To observe the influence of Semen Cannabis oil and sterol on bombyx mori linnaeus life-span and discuss their anti-aging effect. Methods: Sanmian silkworm with the same age and growth were randomly divided into eight groups, namely blank control group, high, middle, low dose of Semen Cannabis oil group, high, meddle, low dose of Semen Cannabis oil and sterol group, positive control group. Physic liquor is daubed on the mulberry leaf ,3 times during 4 instars and 6 times during 5 instars. Results:The life-span of bombyx mori linnaeus larva was significantly longer in high, meddle, low dose of Semen Cannabis oil and sterol group compared with control group(P<0.01 or P<0.05). Semen Cannabis oil and sterol can significantly extend the all life span(P<0.01 or P<0.05). Compared with the blank control group, Semen Cannabis oil and sterol can significantly extend the hunger resistance time during 5 instars (P <0.01), Conclusion:both Semen Cannabis oil and sterol can extend the life span time of bombyx mori Linnaeus during any instars.

  16. Enzyme characteristics of recombinant poly(ADP-ribose) polymerases-1 of rat and human origin mirror the correlation between cellular poly(ADP-ribosyl)ation capacity and species-specific life span.

    Science.gov (United States)

    Beneke, Sascha; Scherr, Anna-Lena; Ponath, Viviane; Popp, Oliver; Bürkle, Alexander

    2010-05-01

    Poly(ADP-ribosyl)ation is a posttranslational modification, which is involved in many cellular functions, including DNA repair and maintenance of genomic stability, and has also been implicated in cellular and organismal ageing. We have previously reported that maximum poly(ADP-ribosyl)ation capacity in mononuclear blood cells is correlated with mammalian life span. Here we show that the difference between a long-lived and a short-lived species tested (i.e. man and rat) is directly mirrored by the enzymatic parameters of recombinant poly(ADP-ribose) polymerase-1 (PARP-1), i.e. substrate affinity and reaction velocity. In addition, we have characterized two human PARP-1 alleles and assign their activity difference to their respective initial velocity and not substrate affinity. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  17. 亚硝酸钠对果蝇寿命影响及Vc拮抗作用研究%Effect of sodium nitrite and Vc on life-span of Drosophila nelanogaste

    Institute of Scientific and Technical Information of China (English)

    张书玲; 董丽军; 王瑞强

    2011-01-01

    以黑腹果蝇(Drosophila melanogaster)为试验材料,探讨了亚硝酸钠对果蝇寿命的影响及维生素C(Vc)的拮抗作用.结果表明:培养基中添加亚硝酸钠可以显著缩短果蝇的平均寿命,添加30、120和480 mg/mL亚硝酸钠处理组的雌果蝇平均寿命分别减少17.60%、44.47%和68.52%,雄性果蝇分别减少4.71%、19.19%和65.95%;在添加480 mg/mL亚硝酸钠的培养基中加入不同浓度Vc,果蝇的平均寿命随Vc浓度的提高而显著延长,其中Vc浓度为0.13%、0.40%、1.20%处理组的雌性果蝇平均寿命分别增加了19.61%、73.63%和114.13%,雄性果蝇分别增加了0.35%、27.49%和137.59%;生化分析显示,果蝇体内SOD活性随Vc浓度的升高而显著增加,而MDA含量随Vc浓度的升高而显著降低.%Fruit flies (Drosophila melanogaster) were used as the experimental material to study the effects of sodium nitrite on life-span and mechanism of antagonism of Vc on sodium nitrite. The results showed that the average life-span of D. melanogaster was significantly shortened in medium with different concentration of sodium nitrite. The average life-span decreased by 17.60%, 44.47% and 68.52% for the female D. melanogaster and 4.71%,19.19% and 65.95% for the male D. melanogaster when the concentration of sodium nitrite was 30 mg/mL,120 mg/mL, and 480 mg/mL. But, when the concentration of Vc was 0.13%, 0.40% and 1.20% in the Medium with 480 mg/mL sodium nitrite, the life-span increased 19.61%,73.63% and 114.13% for female melanogaster, and 0.35%, 27.49% and 137.59% for male D. melanogaster, respectively. With the concentration of Vc increased, the SOD activities increased and the MDA content decreased in both male and female melanogaster significantly.

  18. Chemical genetic screen identifies lithocholic acid as an anti-aging compound that extends yeast chronological life span in a TOR-independent manner, by modulating housekeeping longevity assurance processes

    Science.gov (United States)

    Goldberg, Alexander A.; Richard, Vincent R.; Kyryakov, Pavlo; Bourque, Simon D.; Beach, Adam; Burstein, Michelle T.; Glebov, Anastasia; Koupaki, Olivia; Boukh-Viner, Tatiana; Gregg, Christopher; Juneau, Mylène; English, Ann M.; Thomas, David Y.; Titorenko, Vladimir I.

    2010-01-01

    In chronologically aging yeast, longevity can be extended by administering a caloric restriction (CR) diet or some small molecules. These life-extending interventions target the adaptable target of rapamycin (TOR) and cAMP/protein kinase A (cAMP/PKA) signaling pathways that are under the stringent control of calorie availability. We designed a chemical genetic screen for small molecules that increase the chronological life span of yeast under CR by targeting lipid metabolism and modulating housekeeping longevity pathways that regulate longevity irrespective of the number of available calories. Our screen identifies lithocholic acid (LCA) as one of such molecules. We reveal two mechanisms underlying the life-extending effect of LCA in chronologically aging yeast. One mechanism operates in a calorie availability-independent fashion and involves the LCA-governed modulation of housekeeping longevity assurance pathways that do not overlap with the adaptable TOR and cAMP/PKA pathways. The other mechanism extends yeast longevity under non-CR conditions and consists in LCA-driven unmasking of the previously unknown anti-aging potential of PKA. We provide evidence that LCA modulates housekeeping longevity assurance pathways by suppressing lipid-induced necrosis, attenuating mitochondrial fragmentation, altering oxidation-reduction processes in mitochondria, enhancing resistance to oxidative and thermal stresses, suppressing mitochondria-controlled apoptosis, and enhancing stability of nuclear and mitochondrial DNA. PMID:20622262

  19. Confronting product life thinking with product life cycle analysis

    DEFF Research Database (Denmark)

    McAloone, Tim C.

    2001-01-01

    Industry is increasingly being confronted with the need to consider the whole life cycle effects of its products, in order to make environmental improvements of any significance. There is a danger that naive environmental decisions are made, due to apparent lack of data or actual lack of insight....... This paper describes a case study, where a class of students was presented with a product from the Danish company, Danfoss A/S, and given the task of carrying out an initial environmental evaluation of the product. This evaluation consisted of both a "life cycle check" and an exercise where the students were...... to "read" the environment out of the product, in order to systematically, quickly and efficiently come to some design recommendations for the company. The phrases "LCA" and "product life thinking" will be described and differentiated and a pattern identified for their cooperative effect in use....

  20. Measurement Invariance of Big-Five Factors over the Life Span: ESEM Tests of Gender, Age, Plasticity, Maturity, and La Dolce Vita Effects

    Science.gov (United States)

    Marsh, Herbert W.; Nagengast, Benjamin; Morin, Alexandre J. S.

    2013-01-01

    This substantive-methodological synergy applies evolving approaches to factor analysis to substantively important developmental issues of how five-factor-approach (FFA) personality measures vary with gender, age, and their interaction. Confirmatory factor analyses (CFAs) conducted at the item level often do not support a priori FFA structures, due…

  1. Efficacy of adding a supporting implant in stress distribution of long-span fixed partial dentures: a 3D finite element analysis

    Science.gov (United States)

    Shurbaji Mozayek, Rami; Allaf, Mirza; B. Abuharb, Mohammad

    2016-01-01

    Background. Long span is seen in many clinical situations. Treatmentplanning options of these cases are difficult and may require FPD, RPD or ISP. Each option has its own disadvantages, including mechanical problems, patient comfort and cost. This article will evaluate the stress distribution of a different treatment option, which consists of adding a single sup-porting implant to the FPD by using 3D finite element analysis. Methods. Three models, each consisting of 5 units, were created as follows: 1. Tooth Pontic Pontic Pontic Tooth; 2. Tooth Pontic Implant Pontic Tooth; 3. Tooth Pontic Pontic Implant Tooth. An axial force was applied to the prostheses by using 3D finite element method and stresses were evaluated. Results. The maximum stress was found in the prostheses in all the models; the highest stress values in all the shared components of the models were almost similar. Stress in implants was lower in the second model than the third one. Conclusion. Adding a supporting implant in long-span FPD has no advantages while it has the disadvantages of complicating treatment and the complications that may occur to the implant and surrounding bone. PMID:27429723

  2. Not seeing the forest for the trees: size of the minimum spanning trees (MSTs forest and branch significance in MST-based phylogenetic analysis.

    Directory of Open Access Journals (Sweden)

    Andreia Sofia Teixeira

    Full Text Available Trees, including minimum spanning trees (MSTs, are commonly used in phylogenetic studies. But, for the research community, it may be unclear that the presented tree is just a hypothesis, chosen from among many possible alternatives. In this scenario, it is important to quantify our confidence in both the trees and the branches/edges included in such trees. In this paper, we address this problem for MSTs by introducing a new edge betweenness metric for undirected and weighted graphs. This spanning edge betweenness metric is defined as the fraction of equivalent MSTs where a given edge is present. The metric provides a per edge statistic that is similar to that of the bootstrap approach frequently used in phylogenetics to support the grouping of taxa. We provide methods for the exact computation of this metric based on the well known Kirchhoff's matrix tree theorem. Moreover, we implement and make available a module for the PHYLOViZ software and evaluate the proposed metric concerning both effectiveness and computational performance. Analysis of trees generated using multilocus sequence typing data (MLST and the goeBURST algorithm revealed that the space of possible MSTs in real data sets is extremely large. Selection of the edge to be represented using bootstrap could lead to unreliable results since alternative edges are present in the same fraction of equivalent MSTs. The choice of the MST to be presented, results from criteria implemented in the algorithm that must be based in biologically plausible models.

  3. Leaf life spans of some conifers of the temperate forests of South America Longevidad foliar de algunas coníferas de los bosques templados de Sudamérica

    Directory of Open Access Journals (Sweden)

    CHRISTOPHER H. LUSK

    2001-09-01

    Full Text Available Interspecific variation in leaf life span has wide-ranging implications for plant species sorting on resource availability gradients, and for ecosystem processes such as nutrient cycling. Very little is known about leaf life spans of evergreen trees in the temperate forests of South America. Leaf life spans were estimated by static demographic methods, and associated leaf traits measured, for four conifers of this region. It was expected that leaf life span variation would correlate negatively with soil fertility of habitats normally occupied by each species. This prediction was upheld by the data. The mean leaf life span determined for Araucaria araucana (24 years is among the highest figures reported for any plant species. This extreme leaf longevity was associated with very robust construction (high leaf mass per unit area and very low nitrogen content. These aspects of the ecology of A. araucana may affect its fitness in two ways. Firstly, slow foliage turnover will reduce its annual nutrient requirements for crown maintenance, a trait that is thought to be crucial for survival on nutrient-poor sites. Secondly, the low decomposability of A. araucana leaf litter is likely to cause nutrient immobilisation, possibly favouring site retention by A. araucana in the face of competition from faster-growing but more nutrient-demanding species. Interspecific variation in leaf life span appeared to be systematically related to variation in leaf mass per unit area (LMA and leaf nitrogen, in agreement with a large body of evidence that leaf evolution is constrained by a trade-off between trait combinations which optimise carbon gain and growth in resource-rich habitats, and those which favour persistence in chronically adverse environmentsLas diferencias específicas en longevidad foliar tienen importantes implicancias para la distribución de las plantas en relación con gradientes de recursos, y en procesos ecosistémicos tales como el ciclaje de

  4. Span efficiency in hawkmoths

    OpenAIRE

    Henningsson, Per; Bomphrey, Richard J.

    2013-01-01

    Flight in animals is the result of aerodynamic forces generated as flight muscles drive the wings through air. Aerial performance is therefore limited by the efficiency with which momentum is imparted to the air, a property that can be measured using modern techniques. We measured the induced flow fields around six hawkmoth species flying tethered in a wind tunnel to assess span efficiency, ei, and from these measurements, determined the morphological and kinematic characters that predict eff...

  5. Span efficiency in hawkmoths.

    Science.gov (United States)

    Henningsson, Per; Bomphrey, Richard J

    2013-07-06

    Flight in animals is the result of aerodynamic forces generated as flight muscles drive the wings through air. Aerial performance is therefore limited by the efficiency with which momentum is imparted to the air, a property that can be measured using modern techniques. We measured the induced flow fields around six hawkmoth species flying tethered in a wind tunnel to assess span efficiency, ei, and from these measurements, determined the morphological and kinematic characters that predict efficient flight. The species were selected to represent a range in wingspan from 40 to 110 mm (2.75 times) and in mass from 0.2 to 1.5 g (7.5 times) but they were similar in their overall shape and their ecology. From high spatio-temporal resolution quantitative wake images, we extracted time-resolved downwash distributions behind the hawkmoths, calculating instantaneous values of ei throughout the wingbeat cycle as well as multi-wingbeat averages. Span efficiency correlated positively with normalized lift and negatively with advance ratio. Average span efficiencies for the moths ranged from 0.31 to 0.60 showing that the standard generic value of 0.83 used in previous studies of animal flight is not a suitable approximation of aerodynamic performance in insects.

  6. Nonlinear Stability Analysis of Long-Span Continuous Rigid Frame Bridge with Thin-Wall High Piers

    Institute of Scientific and Technical Information of China (English)

    Li Li; Peng Yuancheng; Long Xiaohong; Liao Ping

    2005-01-01

    By utilizing the current finite element program ANSYS, two types of finite element models (FEM), the beam model (BM) and shell model (SM), are established for the nonlinear stability analysis of a practical rigid frame bridge-Longtanhe Great Bridge. In these analyses, geometrical and material nonlinearities are simultaneously taken into account. For geometrical nonlinearity, updated Lagrangian formulations are adopted to derive the tangent stiffness matrix. In order to simulate the nonlinear behavior of the plastic hinge of the piers, the multi-lines spring element COMBIN39 is used in the SM while the bilinear rotational spring element COMBIN40 is employed in the BM. Numerical calculations show that satisfying results can be obtained in the stability analysis of the bridge when the double coupling nonlinearity effects are considered. In addition, the conclusion is significant for practical engineering.

  7. Trend analysis of performance parameters of pre-packed columns for protein chromatography over a time span of ten years.

    Science.gov (United States)

    Scharl, Theresa; Jungreuthmayer, Christian; Dürauer, Astrid; Schweiger, Susanne; Schröder, Tim; Jungbauer, Alois

    2016-09-23

    Pre-packed small scale chromatography columns are increasingly used for process development, for determination of design space in bioprocess development, and for post-licence process verifications. The packing quality of 30,000 pre-packed columns delivered to customers over a period 10 years has been analyzed by advanced statistical tools. First, the data were extracted and checked for inconsistencies, and then were tabulated and made ready for statistical processing using the programming language Perl (https://www.perl.org/) and the statistical computing environment R (https://www.r-project.org/). Reduced HETP and asymmetry were plotted over time to obtain a trend of packing quality over 10 years. The obtained data were used as a visualized coefficient of variation analysis (VCVA), a process that has often been applied in other industries such as semiconductor manufacturing. A typical fluctuation of reduced HETP was seen. A Tsunami effect in manufacturing, the effect of propagation of manufacturing deviations leading to out-of-specification products, was not observed with these pre-packed columns. Principal component analysis (PCA) showed that all packing materials cluster. Our data analysis showed that the current commercially available chromatography media used for biopharmaceutical manufacturing can be reproducibly and uniformly packed in polymer-based chromatography columns, which are designed for ready-to-use purposes. Although the number of packed columns has quadrupled over one decade the packing quality has remained stable.

  8. Airlift deployment analysis system life cycle cost analysis

    Energy Technology Data Exchange (ETDEWEB)

    Truett, L.F.; Das, S. (Oak Ridge National Lab., TN (USA)); Worthington, J.C. (Sybase, Inc. (USA))

    1990-08-01

    The Airlift Deployment Analysis System (ADANS) is an automated system that will provide Headquarters, Military Airlift Command (HQ MAC) with planning, scheduling, and analysis tools for peacetime and contingency airlift operations. This Life Cycle Cost (LCC) analysis identifies cost factors impacting ADANS during its life cycle. This analysis lists exact costs when known and reasonable estimates of other costs. This report states costs in fiscal year (FY) dollars for costs already expended (FY86--FY89) and in FY90 dollars for projected costs. Factors that could have a substantial impact on the ADANS life cycle development and maintenance costs are noted. The development effort will conclude in FY92. This LCC analysis covers a 15-year period from FY86--FY00. The total costs of ADANS is projected to be approximately $60 million. Of this total, about 20% is for development of functional capability, about 9% for development of the cross-cutting subsystems, and about 71% for program and system support. The total Oak Ridge National Laboratory development cost for FY86--FY92 is about $27.5 million; the total cost for HQ MAC is about 32.5 million. 32 tabs.

  9. An MDM2 antagonist (MI-319 restores p53 functions and increases the life span of orally treated follicular lymphoma bearing animals

    Directory of Open Access Journals (Sweden)

    Yang Dajun

    2009-12-01

    Full Text Available Abstract Background MI-319 is a synthetic small molecule designed to target the MDM2-P53 interaction. It is closely related to MDM2 antagonists MI-219 and Nutlin-3 in terms of the expected working mechanisms. The purpose of this study was to evaluate anti-lymphoma activity of MI-319 in WSU-FSCCL, a B-cell follicular lymphoma line. For comparison purpose, MI-319, MI-219 and Nutlin-3 were assessed side by side against FSCCL and three other B-cell hematological tumor cell lines in growth inhibition and gene expression profiling experiments. Results MI-319 was shown to bind to MDM2 protein with an affinity slightly higher than that of MI-219 and Nutlin-3. Nevertheless, cell growth inhibition and gene expression profiling experiments revealed that the three compounds have quite similar potency against the tumor cell lines tested in this study. In vitro, MI-319 exhibited the strongest anti-proliferation activity against FSCCL and four patient cells, which all have wild-type p53. Data obtained from Western blotting, cell cycle and apoptosis analysis experiments indicated that FSCCL exhibited strong cell cycle arrest and significant apoptotic cell death; cells with mutant p53 did not show significant apoptotic cell death with drug concentrations up to 10 μM, but displayed weaker and differential cell cycle responses. In our systemic mouse model for FSCCL, MI-319 was tolerated well by the animals, displayed effectiveness against FSCCL-lymphoma cells in blood, brain and bone marrow, and achieved significant therapeutic impact (p 28% (%ILS, 14.4 days increase in median survival days. Conclusion Overall, MI-319 probably has an anti-lymphoma potency equal to that of MI-219 and Nutlin-3. It is a potent agent against FSCCL in vitro and in vivo and holds the promises to be developed further for the treatment of follicular lymphoma that retains wild-type p53.

  10. Health monitoring data analysis and comparison of prototype and laboratorial model for long-span cable-stayed bridge

    Science.gov (United States)

    Yang, Ou; Ou, Jinping

    2009-03-01

    Since 2004, Shandong Binzhou Yellow River highway bridge health monitoring (SHM) system has started to operate. Abundance data has been acquired during these years. To make full use of these data, a 1/40 scale laboratorial model has been built based on the design information of Shandong Binzhou Yellow River highway bridge. And a health monitoring system of the laboratorial model, which included loading system, local response monitoring subsystem and global response monitoring subsystem, has been designed and implemented. The dynamic performance of bridge model and prototype has been compared and the error analysis has been provided also. The numeric simulation of cable damage localization utilizing damage location vectors (DLVs) has been demonstrated. And the results indicated that using DLVs to localize the cable damage is feasible and accurate. The goal of these efforts is to utilize the convenience of the laboratorial environment to obtain the structural information in ideal state which is hard to get in field.

  11. Connector design in a long-span-fixed dental prosthesis: A three-dimensional finite element analysis

    Directory of Open Access Journals (Sweden)

    B H Harshitha Gowda

    2013-01-01

    Full Text Available Objectives: The goal of every prosthetic management is to simulate nature and be in harmony with nature within the physiological limits. The occlusal forces on a fixed dental prosthesis are transmitted to the surrounding structures through pontics, connectors and retainers and more stresses are seen at the connector region. To analyze the stress patterns in cast and soldered connectors between the two pontics and between the retainer and pontic of a four unit fixed dental prosthesis on axial and non axial loading and also to observe and ascertain the need to modify the design of the rigid connectors. Materials and Methods: Subsequently four models each of cast and soldered connectors with cylindrical and triangular design, of dimension 3 × 4 mm and thickness 0.5 mm was designed for the study. The first premolar and second molar were considered as the abutments and 2 nd premolar and 1 st molar as the pontics. The analysis was done using ANSYS version 8.0 software and by placing axial and non-axial load of 40 Newtons each. Results: Von Misses stresses were observed at the connector region between the two pontics, especially in the cervical region. Conclusion: The cylindrical cast connectors showed less stress in comparison to triangular design and the difference in the stress distribution of cast and soldered connectors were marginal. Clinical Significance: The occlusal forces on a fixed dental prosthesis are transmitted to the surrounding structures through pontics, connectors and retainers with maximum stresses concentrated at the connectors. Hence this three-dimensional finite element analysis study investigated stress distribution in a four unit posterior fixed dental prosthesis, having cylindrical and triangular connector designs.

  12. Life-span effects of ionizing radiation in the beagle dog: A summary account of four decades of research funded by the US Department of Energy and its predecessor agencies

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, R.C.

    1989-01-01

    Nearly 40 years ago, the US Atomic Energy Commission made a far- reaching commitment to the support of life-span radiation-effects studies in a relatively long-lived animal, the beagle dog. Something in the range of 200 million dollars has already been spent on a group of closely related experiments, many of which are only now coming to fruition. Responsible fiscal management of these studies, directed toward securing an optimum return from past investments, and toward creative planning of future directions, requires a comprehensive view of this total effort. This report is designed to provide that comprehensive view. This is primarily intended as a research management document. Evaluation and interpretation are tasks for those directly involved in conducting these experiments. The limited objective of the present document is to describe what has been done, to give some of the background for why it was done, to describe results already realized and applications that have been made of these results -- all in a manner designed to display the total effort rather than piecemeal details. While proposing no specific answers to the questions ''Where do we go from here.''it is hoped that the document will provide a basis for approaching that question in an informed manner. The maintenance of a continuity of scientific understanding and direction in these experiments, which often continue beyond the initiating investigators' working life, is no small part of the problem involved in conducting these experiments.

  13. Team-level predictors of innovation at work: a comprehensive meta-analysis spanning three decades of research.

    Science.gov (United States)

    Hülsheger, Ute R; Anderson, Neil; Salgado, Jesus F

    2009-09-01

    This article presents a meta-analysis of team-level antecedents of creativity and innovation in the workplace. Using a general input-process-output model, the authors examined 15 team-level variables researched in primary studies published over the last 30 years and their relation to creativity and innovation. An exhaustive search of the international innovation literature resulted in a final sample (k) of 104 independent studies. Results revealed that team process variables of support for innovation, vision, task orientation, and external communication displayed the strongest relationships with creativity and innovation (rhos between 0.4 and 0.5). Input variables (i.e., team composition and structure) showed weaker effect sizes. Moderator analyses confirmed that relationships differ substantially depending on measurement method (self-ratings vs. independent ratings of innovation) and measurement level (individual vs. team innovation). Team variables displayed considerably stronger relationships with self-report measures of innovation compared with independent ratings and objective criteria. Team process variables were more strongly related to creativity and innovation measured at the team than the individual level. Implications for future research and pragmatic ramifications for organizational practice are discussed in conclusion.

  14. A comparative analysis of South African Life Sciences and Biology ...

    African Journals Online (AJOL)

    Hennie

    Keywords: Biology textbooks; Life Sciences textbooks; nature of science; school ... reform, this article reports on the analysis of South African Life Sciences and Biology .... molecular studies; structures and control processes; ..... References.

  15. Life Cycle Multi-Criteria Analysis Of Alternative Energy Supply Systems For A Residential Building

    Directory of Open Access Journals (Sweden)

    Artur Rogoža

    2013-12-01

    Full Text Available The article analyses energy supply alternatives for a partially renovated residential building. In addition to the existing district heating (base case alternative systems, gas boilers, heat pumps (air-water and ground-water, solar collectors, solar cells, and combinations of these systems have been examined. Actual heat consumption of the building and electricity demand determined by the statistical method are used for simulating the systems. The process of simulation is performed using EnergyPro software. In order to select an optimal energy supply option, the life cycle analysis of all systems has been carried out throughout a life span of the building, and the estimated results of energy, environmental and economic evaluation have been converted into non-dimensional variables (3E using multi–criteria analysis.Article in Lithuanian

  16. Parameters analysis for assistant cables of system for transient main cable and catwalk of long-span suspension bridges at construction stages

    Science.gov (United States)

    Li, Shengli; Ou, Jinping

    2009-03-01

    On the basis of static, dynamic and transient analysis for the prestressing cable structures, the parameters to control the vibration of the system for transient main cables and catwalk of some long-span suspension bridge at the construction stages with the assistant cables are investigated adopting the method of the finite element considering the geometry nonlinearity. The review and prospect to control vibration with assistant cables are summarized, the finite element modeling of the system for transient main cables and catwalk is established, and the influence of the position of the assistant cables, disposed fashion and the tensile forces upon the critical frequencies of the system for transient main cables and catwalk is researched. At the same time, the effect of the damp and the tensile forces of the assistant cables on the equivalent damping ratio of the system for transient main cables and catwalk inside and outside the plane is studied and the effect to control the vibration of the system is analysed. In the end, the influence of the transformation for the tensile forces about assistant cables upon those of the transient main cables and catwalk is also investigated. Results show that, to increase the critical frequencies of the system, the assistant cables should be laid vertically with the main cables and be located in interim span or between the tower and interim span, and to increase the amount of the assistant cables can increase the critical frequencies ,and to increase the rigidities of the assistant cables can improve the ones of the transient main cables but decrease the anti-torsion ability of the catwalks, and to increase the damp of the assistant cables can improve the vibration of the transient main cables inside and outside the plane but the result is little outside the plane, and in addition the effect of the rigidities of the assistant cables is larger outside the plane but is little inside the plane. The results also show that the

  17. 大跨径人行桥人致振动舒适度分析%Analysis for Comfort of Pedestrian-induced Vibration on Large-span Pedestrian Bridges

    Institute of Scientific and Technical Information of China (English)

    傅科奇; 胡佐平; 王成树

    2015-01-01

    人行桥的主要荷载源于行人和非机动车,对于大跨径轻柔桥梁结构,在行人激励之下更容易发生大幅振动,引起舒适度问题。依托国内某大跨径人行提篮拱桥,参考国外人行桥设计指南,通过有限元时程分析方法,计算获得不同荷载激励下结构最大加速度响应时程曲线,进行行人振动舒适度评价。另外,针对不同模态设计相应的TMD减振系统,并进行减振效果分析。%Main loads of pedestrian bridges come from pedestrians and non-motor vehicles,and large-span soft bridge structures under motivation of pedestrians are more vulnerable to large vibration to cause comfort problem.Dependent on a domestic large-span pedestrian X-style arch bridge and by reference to foreign guide for design of pedestrian bridges, this paper calculates and obtains the maximum. acceleration response time-history curve of structures under motivation of different loads by means of finite element time -history analysis method to evaluate comfort under pedestrian vibration.in addition,the paper designs corresponding TMD vibration damping systems against different modes and analyzes damping effect.

  18. Mechanisms of change in adolescent life satisfaction: a longitudinal analysis.

    Science.gov (United States)

    Lyons, Michael D; Huebner, E Scott; Hills, Kimberly J; Van Horn, M Lee

    2013-10-01

    This study explored the psychosocial mechanisms of change associated with differences in levels and linear change of adolescents' global life satisfaction across a 2-year time period. Based on a theoretical model proposed by Evans (1994), this study tested the relations between selected personality (i.e., extraversion and neuroticism) and environmental (stressful life events) variables and global life satisfaction when mediated by internalizing and externalizing problems. The results suggested support for internalizing problems as a mediator of the relationship of personality and environmental variables with life satisfaction. Pathways mediated by internalizing problems significantly predicted levels and linear change of life satisfaction across a 2-year time span. Furthermore, pathways mediated by externalizing problems significantly predicted the level but not the linear change of life satisfaction. Thus, behavior problems and their antecedents appear to relate significantly to adolescents' perceptions of their quality of life. Implications for adolescent mental health promotion were discussed. Copyright © 2013 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  19. The principles of life-cycle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hill, L.J.; Hunsaker, D.B.; Curlee, T.R.

    1996-05-01

    Decisionmakers representing government agencies must balance competing objectives when deciding on the purchase and sale of assets. The goal in all cases should be to make prudent or financially {open_quotes}cost-effective{close_quotes} decisions. That is, the revenues from the purchase or sale of assets should exceed any out-of-pocket costs to obtain the revenues. However, effects external to these financial considerations such as promoting environmental quality, creating or maintaining jobs, and abiding by existing regulations should also be considered in the decisionmaking process. In this paper, we outline the principles of life-cycle analysis (LCA), a framework that allows decisionmakers to make informed, balanced choices over the period of time affected by the decision, taking into account important external effects. Specifically, LCA contains three levels of analysis for any option: (1) direct financial benefits (revenues) and out-of-pocket costs for a course of action; (2) environmental and health consequences of a decision; and (3) other economic and socio-institutional effects. Because some of the components of LCA are difficult to value in monetary terms, the outcome of the LCA process is not generally a yes-no answer. However, the framework allows the decisionmaker to at least qualitatively consider all relevant factors in analyzing options, promoting sound decisionmaking in the process.

  20. Life Span Personality Stability in Sibling Statuses.

    Science.gov (United States)

    Rosenberg, B. G.

    Personality stability and change in sibling status in the one- and two-child-family are examined in this Study. Q-sort data were analyzed for the same 33 male and 34 female subjects during four periods of their lives-- early and late adolescence and early and middle adulthood. Results indicate that stability of personality was greatest during…

  1. Life-span distributions of supermarket products

    Science.gov (United States)

    Ueno, Hiromichi; Watanabe, Tsutomu; Takayasu, Misako

    2010-04-01

    We have analyzed the lifetime distributions of more than 0.7 million products sold across approximately 400 Japanese supermarkets. The distributions are well approximated by an exponential function for products with lifetimes longer than 1000 days, implying that the manufacturers' decisions about whether to continue production are purely random. However, the distributions tend to deviate from an exponential distribution for products with lifetimes shorter than 1000 days. Specifically, the distributions for food products exhibit a quicker decay in a short time scale, suggesting the existence of competing products during the initial stages of the product lifecycle. On the other hand, the distributions for toiletry products exhibit a slower decay in a short time scale.

  2. Life-span of leadwood trees

    CSIR Research Space (South Africa)

    Vogel, JC

    2005-01-01

    Full Text Available bythecombustionoffossilfuelsthatdonotcontaintheradioactive isotope. After AD 1954, the testing of nuclear fusion bombs dramaticallyincreasedthe14Ccontentintheatmosphere,sothat material dating to after this date shows an elevated 14C level and can be pinpointed precisely to ?1 year.4 Materials and method... dead tree near Letaba rest camp, collected in 1980 and submitted by C.F. Garbers. The radiocar- bon content of the sample was 21.8% above the standard for modern carbon, indicating that the wood was formed after the pollution by nuclear weapon tests...

  3. Effect of Resveratrol on Life-span and Antioxidation in Drosophila Melanogaster%白藜芦醇对果蝇寿命和抗氧化能力的影响

    Institute of Scientific and Technical Information of China (English)

    刘贵珊; 张泽生; 杨博; 贺伟

    2013-01-01

      To discuss the effect of resveratrol on the life-span and the antioxidation in Drosophila melanogaster , newly eclosed male fruit flies were divided randomly into 4 groups , which were treated with different concentration (0,2.5,5,10 mg/mL) of resveratrol . In lifespan study , dead flies were counted every three days until all flies died. The lifespan , the activities of superoxide dismutase (SOD), catalase (CAT) and the content of malondialdehyde (MDA) were determined. The experimental results show that resveratrol extends the maximum lifespan and mean lifespan of Drosophila melanogaster , exhibiting a dosage effect . The activities of SOD and CAT increase, meanwhile the content of MDA decreases in the experiment. The Conclusions prove that resveratrol can increase antioxidative effect , reduce lipid peroxidation and prolong the life-span in Drosophila.%  探讨白藜芦醇对黑腹果蝇寿命和抗氧化功能的影响。将2d龄雄性果蝇随机分组,用涂布了不同剂量的白藜芦醇(0、2.5、5、10 mg/mL)的培养基饲喂果蝇,每隔3天记录果蝇死亡数,直至全部死亡。测定白藜芦醇对果蝇寿命和超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性以及丙二醛(MDA)含量的影响。研究结果表明:饲喂白藜芦醇后,果蝇最高寿命及平均寿命均随剂量的增大而延长,提高了SOD和CAT活性,降低了MDA含量。说明白藜芦醇可以提高果蝇的抗氧化能力,抑制脂质过氧化,延长果蝇寿命。

  4. Spectral Processing Analysis System (SPANS).

    Science.gov (United States)

    1980-11-01

    made possible by use of a Programmable Input Output Processor ( PIOP ) provided by FPS. The PIOP is actually a microprocessor which handles all...hardware which involved three processors, the PDP-ll, AP-120B array processor and PIOP microprocessor which communicates with the CDC disk drive. The...120B. PIOP assembler was used to program the microprocessor to control the disk drive. Modifications were necessary to the standard PIOP soft- ware

  5. 跨铁路站场斜拉桥荷载试验分析%Analysis on Loading Test of Cable-stayed Bridge Spanning Railway Station

    Institute of Scientific and Technical Information of China (English)

    刘邵平

    2011-01-01

    和平大桥位于城市主干道上,跨越徐州铁路站场,铁路交通量极大。为了检验成桥后该桥梁承载能力是否满足正常使用状况的要求以及评估实际结构的动力性能,对全桥展开荷载试验分析。研究结果表明,和平大桥的受力性能和正常使用状态极限承载力满足设计荷载等级城-A级要求,结构工作状况良好。%Heping bridge with heavy-volume traffic is located at urban arterial road and spans a railway station.To test wheather the bearing capacity under normal service loading could meet criterion or not and evaluate the dynamic characteristics of the bridge,loading test analysis is proposed in this paper.The results show that the mechanical behavior and the ultimate bearing capacity under normal service loading of Heping bridge meet the design load grade-A standard and Heping bridge is in good working condition.

  6. Traveling Wave Resonance and Simplified Analysis Method for Long-Span Symmetrical Cable-Stayed Bridges under Seismic Traveling Wave Excitation

    OpenAIRE

    Zhong-ye Tian; Meng-lin Lou

    2014-01-01

    The seismic responses of a long-span cable-stayed bridge under uniform excitation and traveling wave excitation in the longitudinal direction are, respectively, computed. The numerical results show that the bridge’s peak seismic responses vary significantly as the apparent wave velocity decreases. Therefore, the traveling wave effect must be considered in the seismic design of long-span bridges. The bridge’s peak seismic responses do not vary monotonously with the apparent wave velocity due t...

  7. Pedobarographic analysis and quality of life after lisfranc fracture dislocation

    NARCIS (Netherlands)

    T. Schepers (Tim); B.C.T. Kieboom (Brenda); P. van Diggele (Peter); P. Patka (Peter); E.M.M. van Lieshout (Esther)

    2010-01-01

    textabstractBackground: Few studies on tarsometatarsal fracture dislocations report on plantar pressure analysis and quality of life. The primary aim of this study was to determine the added value of plantar pressure analysis. The secondary aim was to determine quality of life and functional outcome

  8. Social network sampling using spanning trees

    Science.gov (United States)

    Jalali, Zeinab S.; Rezvanian, Alireza; Meybodi, Mohammad Reza

    2016-12-01

    Due to the large scales and limitations in accessing most online social networks, it is hard or infeasible to directly access them in a reasonable amount of time for studying and analysis. Hence, network sampling has emerged as a suitable technique to study and analyze real networks. The main goal of sampling online social networks is constructing a small scale sampled network which preserves the most important properties of the original network. In this paper, we propose two sampling algorithms for sampling online social networks using spanning trees. The first proposed sampling algorithm finds several spanning trees from randomly chosen starting nodes; then the edges in these spanning trees are ranked according to the number of times that each edge has appeared in the set of found spanning trees in the given network. The sampled network is then constructed as a sub-graph of the original network which contains a fraction of nodes that are incident on highly ranked edges. In order to avoid traversing the entire network, the second sampling algorithm is proposed using partial spanning trees. The second sampling algorithm is similar to the first algorithm except that it uses partial spanning trees. Several experiments are conducted to examine the performance of the proposed sampling algorithms on well-known real networks. The obtained results in comparison with other popular sampling methods demonstrate the efficiency of the proposed sampling algorithms in terms of Kolmogorov-Smirnov distance (KSD), skew divergence distance (SDD) and normalized distance (ND).

  9. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

    The first Scandinavian bridge with a span of more than 500 m was the Lillebælt Suspension Bridge opened to traffic in 1970.Art the end of the 20th century the longest span of any European bridge is found in the Storebælt East Bridge with a main span of 1624 m. Also the third longest span in Europe...... is found in Scandinavia - the 1210 m span of the Höga Kusten Bridge in Sweden.The Kvarnsund Bridge in Norway was at the completion in 1991 the longest cable-stayed bridge in the world, and the span of 530 m is still thge longest for cable-stayed bridges in concrete. The Øresund Bridge with its sapn of 490...... m is the longest among cable-stayed bridges for both road and railway traffic....

  10. Life cycle analysis of transportation fuel pathways

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-02-24

    The purpose of this work is to improve the understanding of the concept of life cycle analysis (LCA) of transportation fuels and some of its pertinent issues among non-technical people, senior managers, and policy makers. This work should provide some guidance to nations considering LCA-based policies and to people who are affected by existing policies or those being developed. While the concept of employing LCA to evaluate fuel options is simple and straightforward, the act of putting the concept into practice is complex and fraught with issues. Policy makers need to understand the limitations inherent in carrying out LCA work for transportation fuel systems. For many systems, even those that have been employed for a 100 years, there is a lack of sound data on the performance of those systems. Comparisons between systems should ideally be made using the same tool, so that differences caused by system boundaries, allocation processes, and temporal issues can be minimized (although probably not eliminated). Comparing the results for fuel pathway 1 from tool A to those of fuel system 2 from tool B introduces significant uncertainty into the results. There is also the question of the scale of system changes. LCA will give more reliable estimates when it is used to examine small changes in transportation fuel pathways than when used to estimate large scale changes that replace current pathways with completely new pathways. Some LCA tools have been developed recently primarily for regulatory purposes. These tools may deviate from ISO principles in order to facilitate simplicity and ease of use. In a regulatory environment, simplicity and ease of use are worthy objectives and in most cases there is nothing inherently wrong with this approach, particularly for assessing relative performance. However, the results of these tools should not be confused with, or compared to, the results that are obtained from a more complex and rigorous ISO compliant LCA. It should be

  11. Low doses of paraquat and polyphenols prolong life span and locomotor activity in knock-down parkin Drosophila melanogaster exposed to oxidative stress stimuli: implication in autosomal recessive juvenile parkinsonism.

    Science.gov (United States)

    Bonilla-Ramirez, Leonardo; Jimenez-Del-Rio, Marlene; Velez-Pardo, Carlos

    2013-01-10

    Previous studies have shown that polyphenols might be potent neuroprotective agents in Drosophila melanogaster wild type Canton-S acutely or chronically treated with paraquat (PQ), a selective toxin for elimination of dopaminergic (DAergic) neurons by oxidative stress (OS), as model of Parkinson's disease (PD). This study reports for the first time that knock-down (K-D) parkin Drosophila melanogaster (TH-GAL4; UAS-RNAi-parkin) chronically exposed to PQ (0.1-0.25 mM), FeSO(4) (Fe, 0.1mM), deferoxamine (DFO, 0.01 mM) alone or (0.1mM) PQ in combination with polyphenols propyl gallate (PG, 0.1mM) and epigallocathecin gallate (EGCG, 0.1, 0.5mM) showed significantly higher life span and locomotor activity than untreated K-D flies or treated with (1, 5, 20mM) PQ alone. Whilst gallic acid (GA, 0.1, 0.5mM) alone or in the presence of PQ provoked no effect on K-D flies, epicathecin (EC, 0.5mM) only showed a positive effect on prolonging K-D flies' life span. It is shown that PG (and EGCG) protected protocerebral posterolateral 1 (PPL1) DAergic neurons against PQ. Interestingly, the protective effect of low PQ concentrations, DFO and iron might be explained by a phenomenon known as "hormesis." However, pre-fed K-D flies with (0.1mM) PQ for 7 days and then exposed to (0.25 mM) for additional 8 days affect neither survival nor climbing of K-D Drosophila compared to flies treated with (0.25 mM) PQ alone. Remarkably, K-D flies treated with 0.1mM PQ (7 days) and then with (0.25 mM) PQ plus PG (8 days) behaved almost as flies treated with (0.25 mM) PQ. Taken these data suggest that antioxidant supplements that synergistically act with low pro-oxidant stimuli to prolong and increase locomotor activity become inefficient once a threshold of OS has been reached in K-D flies. Our present findings support the notion that genetically altered Drosophila melanogaster as suitable model to study genetic and environmental factors as causal and/or modulators in the development of autosomal

  12. Actuarial contributions to life table analysis.

    Science.gov (United States)

    Lew, E A

    1985-05-01

    The correct principles for the construction of life tables and more particularly select life tables were developed by actuaries in England in the first half of the 19th century. Actuaries explored the phenomenon of selection not only between the insured and annuitants but also in the general population, distinguishing among initial temporary selection, antiselection, and class selection. The conclusion was reached early that no such thing as an unselected population exists. Group life insurance experience among the actively employed has been shown to provide a more appropriate standard of expected mortality than general population death rates in studies of medical impairments and occupational hazards at ages under 65 years. Mortality rates derived from the Cancer Prevention Study can serve as a useful standard of expected mortality when the objective is determination of excess mortality compared with ostensibly healthy persons at ages 65 years and older.

  13. Effects of Sodium Nitrite on Life-span, Superoxide Dismutase Activity and Malondialdehyde Content in Drosophila Melanogaster%亚硝酸钠对果蝇寿命及SOD和MDA的影响

    Institute of Scientific and Technical Information of China (English)

    张书玲; 董丽军; 刘龙

    2011-01-01

    In this study, Drosophila melanogaster was used as the experimental animal to study the. effects of sodium nitrite on life-span, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in D. melanogaster. The results showed that sodium nitrite significantly shortened drosophila average lifespan. The decreased average life-span of female D. melanogaster was 12.53,31.49 and 48.79 days when the concentrations of sodium nitrite were 30,120 and 480 g/L. Average life-span of the male was short ened 3.15 d, 12.83 and 44. 11 days, respectively. After cultured with the sodium nitrite, the activities of the SOD decreased and MDA content increased. Compared to the control group, the activities of the SOD of female D. melanogaster decreased 8. 52% ,31.06% and 41.69% or 14.79% ,34.64% ,and 47.78%(P <0.05 or P<0. 01) when D. melanogaster was fed with sodium nitrite at the concentration of 30,120 and 480g/L for 10d and 20d, while the MDA content increased 26. 94%, 48. 71%, 72. 02% and 20. 63%,40. 56% ,83.92% (P<0.05 or P<0. 01). The activities of the SOD of male D. melanogaster decreased 9. 47%, 34. 13%, 44. 62% and 11. 18%, 31.66%, 46. 10% while MDA content increased 21.74% ,48. 40% ,74.46% and 24.91% ,45.67% ,74.39%. Compared to the control group,SOD activity and MDA content significantly increased in sodium nitrite (P<0. 05 or P<O. 01) except for SOD activity of 30 g/L sodium nitrite experimental group after male D. melanogaster fed 10 days.%以果蝇(Drosophila melanogaster)为试验动物,探讨亚硝酸钠对果蝇寿命、超氧化物岐化酶(SOD)活性及丙二醛(MDA)含量的影响.结果表明:培养基中添加亚硝酸钠能显著缩短果蝇平均寿命,其中30//L、120g/L和480g/L组雌果蝇平均寿命与对照组相比分别缩短了12.53、31.49、48.79d,雄果蝇平均寿命与对照组相比分别缩短了3.15、12.83、44.11 d.饲喂亚硝酸钠后果蝇体内的SOD活性降低,MDA

  14. 大跨径桥梁施工控制不确定因素分析%Analysis of the Uncertain Factors of Long Span Bridge Construction Control

    Institute of Scientific and Technical Information of China (English)

    徐志学

    2014-01-01

    There are many uncertain factors affecting the bridge construction quality in the process of long-span bridge construction. This article mainly analyzes the temperature eff-ect, temperature load and some control methods of the long-span bridge construction, and reduces the influence of unc-ertain factors on the quality of long-span bridges.%在大跨径桥梁施工过程中,有许多不确定因素影响着桥梁的施工质量。本文对温度效应、温度载荷以及大跨径桥梁施工过程中的一些控制方法进行了分析,降低了不确定因素对大跨径桥梁的质量影响。

  15. Analysis within the systems development life-cycle

    CERN Document Server

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle: Book 2, Data Analysis-The Methods describes the methods for carrying out data analysis within the systems development life-cycle and demonstrates how the results of fact gathering can be used to produce and verify the analysis deliverables. A number of alternative methods of analysis other than normalization are suggested. Comprised of seven chapters, this book shows the tasks to be carried out in the logical order of progression-preparation, collection, analysis of the existing system (which comprises the tasks of synthesis, verification, an

  16. A Life-Cycle Analysis of Social Security with Housing

    OpenAIRE

    Chen, Kaiji

    2009-01-01

    This paper incorporates two features of housing in a life-cycle analysis of social security: housing as a durable good and housing market frictions. We find that with housing as a durable good unfunded social security substantially crowds out housing consumption throughout the life cycle. By contrast, aggregate non-durable consumption is higher when social security is present, although it is postponed until late in life. Moreover, in the presence of housing market frictions, social security l...

  17. Traveling Wave Resonance and Simplified Analysis Method for Long-Span Symmetrical Cable-Stayed Bridges under Seismic Traveling Wave Excitation

    Directory of Open Access Journals (Sweden)

    Zhong-ye Tian

    2014-01-01

    Full Text Available The seismic responses of a long-span cable-stayed bridge under uniform excitation and traveling wave excitation in the longitudinal direction are, respectively, computed. The numerical results show that the bridge’s peak seismic responses vary significantly as the apparent wave velocity decreases. Therefore, the traveling wave effect must be considered in the seismic design of long-span bridges. The bridge’s peak seismic responses do not vary monotonously with the apparent wave velocity due to the traveling wave resonance. A new traveling wave excitation method that can simplify the multisupport excitation process into a two-support excitation process is developed.

  18. Spanning trees crossing few barriers

    NARCIS (Netherlands)

    Asano, T.; Berg, M. de; Cheong, O.; Guibas, L.J.; Snoeyink, J.; Tamaki, H.

    2002-01-01

    We consider the problem of finding low-cost spanning trees for sets of n points in the plane, where the cost of a spanning tree is defined as the total number of intersections of tree edges with a given set of m barriers. We obtain the following results: (i) if the barriers are possibly intersecting

  19. Accelerated life models modeling and statistical analysis

    CERN Document Server

    Bagdonavicius, Vilijandas

    2001-01-01

    Failure Time DistributionsIntroductionParametric Classes of Failure Time DistributionsAccelerated Life ModelsIntroductionGeneralized Sedyakin's ModelAccelerated Failure Time ModelProportional Hazards ModelGeneralized Proportional Hazards ModelsGeneralized Additive and Additive-Multiplicative Hazards ModelsChanging Shape and Scale ModelsGeneralizationsModels Including Switch-Up and Cycling EffectsHeredity HypothesisSummaryAccelerated Degradation ModelsIntroductionDegradation ModelsModeling the Influence of Explanatory Varia

  20. Using C-Span in the Classroom to Enhance Student Analysis of Ross Perot's Sensitivity with American Diversity During the 1992 Presidential Campaign

    Science.gov (United States)

    Schnell, James

    2007-01-01

    The C-SPAN application to be described in this article is useful in the Cross-Cultural Communication and Mass Media courses. This application focuses on how we define what connotes sensitivity & insensitivity with diversity issues and how journalistic interpretation can affect our perception via mass media. Businessman Ross Perot rose from…

  1. Analysis within the systems development life-cycle

    CERN Document Server

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle: Book 4, Activity Analysis-The Methods describes the techniques and concepts for carrying out activity analysis within the systems development life-cycle. Reference is made to the deliverables of data analysis and more than one method of analysis, each a viable alternative to the other, are discussed. The """"bottom-up"""" and """"top-down"""" methods are highlighted. Comprised of seven chapters, this book illustrates how dependent data and activities are on each other. This point is especially brought home when the task of inventing new busin

  2. Analysis within the systems development life-cycle

    CERN Document Server

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle: Book 1, Data Analysis-The Deliverables provides a comprehensive treatment of data analysis within the systems development life-cycle and all the deliverables that need to be collected in analysis. The purpose of deliverables is explained and a number of alternative ways of collecting them are discussed. This book is comprised of five chapters and begins with an overview of what """"analysis"""" actually means, with particular reference to tasks such as hardware planning and software evaluation and where they fit into the overall cycle. The ne

  3. Recent Methodologies for Creep Deformation Analysis and Its Life Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woo-Gon; Park, Jae-Young; Iung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    To design the high-temperature creeping materials, various creep data are needed for codification, as follows: i) stress vs. creep rupture time for base metals and weldments (average and minimum), ii) stress vs. time to 1% total strain (average), iii) stress vs. time to onset of tertiary creep (minimum), and iv) constitutive eqns. for conducting time- and temperature- dependent stress-strain (average), and v) isochronous stress-strain curves (average). Also, elevated temperature components such as those used in modern power generation plant are designed using allowable stress under creep conditions. The allowable stress is usually estimated on the basis of up to 10{sup 5} h creep rupture strength at the operating temperature. The master curve of the “sinh” function was found to have a wider acceptance with good flexibility in the low stress ranges beyond the experimental data. The proposed multi-C method in the LM parameter revealed better life prediction than a single-C method. These improved methodologies can be utilized to accurately predict the long-term creep life or strength of Gen-IV nuclear materials which are designed for life span of 60 years.

  4. Battery life-cycle cost analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.R.; Humphreys, K.K.

    1988-07-01

    Life-cycle cost (LCC) estimates have been prepared for 17 combinations of battery or fuel-cell technologies and load-levelling, stand-alone power system, or electric vehicle applications. In addition, LCCs for gas-fired turbine, compressed-air energy storage, pumped hydro energy storage, and internal combustion engine technologies were estimated for comparative purposes. The objectives in preparing the estimates were to determine the relative economics among alternative battery systems and to compare battery systems economics with competing energy technologies.

  5. Life-cycle analysis of renewable energy systems

    DEFF Research Database (Denmark)

    Sørensen, Bent

    1994-01-01

    An imlementation of life-cycle analysis (LCA) for energy systems is presented and applied to two renewable energy systems (wind turbines and building-integrated photovoltaic modules) and compared with coal plants......An imlementation of life-cycle analysis (LCA) for energy systems is presented and applied to two renewable energy systems (wind turbines and building-integrated photovoltaic modules) and compared with coal plants...

  6. Nonparametric inference procedures for multistate life table analysis.

    Science.gov (United States)

    Dow, M M

    1985-01-01

    Recent generalizations of the classical single state life table procedures to the multistate case provide the means to analyze simultaneously the mobility and mortality experience of 1 or more cohorts. This paper examines fairly general nonparametric combinatorial matrix procedures, known as quadratic assignment, as an analysis technic of various transitional patterns commonly generated by cohorts over the life cycle course. To some degree, the output from a multistate life table analysis suggests inference procedures. In his discussion of multstate life table construction features, the author focuses on the matrix formulation of the problem. He then presents several examples of the proposed nonparametric procedures. Data for the mobility and life expectancies at birth matrices come from the 458 member Cayo Santiago rhesus monkey colony. The author's matrix combinatorial approach to hypotheses testing may prove to be a useful inferential strategy in several multidimensional demographic areas.

  7. Effects of extracts from green tea on life - span and fecundity of Drosophila melanogaster%绿茶提取物对果蝇寿命和繁殖力的影响

    Institute of Scientific and Technical Information of China (English)

    赵锦慧; 陈璨; 师杨

    2012-01-01

    Drosophila melanogaster were divided into control group and treatment groups and treatment groups were fed with medium containing extracts from green tea, counted the number of live and death every day until all the Drosophila melanogaster died and calculated the mean and maximum lifespan, furthermore, paired male and female Drosophila melanogaster of no mating and cultivated them, counted up the number of imago of Drosophila melanogaster when the offsprings appeared. The results showed that low concentration extracts from green tea(3 mg/mL-6 mg/mL) could lengthen the mean and maximum lifespan, promote the fecundity of Drosophila melanogaster remarkably, however, high concentration extracts from green tea(12 mg/mL) could shorten the mean and maximum life - span, diminish the fecundity of Drosophila melanogaster.%采用乙醚麻醉法,收集8h内羽化的果蝇成虫,雌雄分开培养,随机分为对照组和处理组(绿茶提取物质量浓度分别为3mg/mL,6mg/mL,12mg/mL),每组饲喂相应的培养基,统计其寿命.另取未交配的雌雄果蝇成对放入培养基中,待出现子代成蝇时,统计成蝇数量,记录7d内成蝇羽化的数目,连续培养调查3代,观察绿茶提取物对果蝇繁殖力的影响.结果表明:绿茶提取物质量浓度为3mg/mL~6mg/mL时能显著延长果蝇平均寿命和最高寿命,并能显著提高果蝇繁殖力,质量浓度为12mg/mL时反而缩短果蝇寿命并降低果蝇繁殖力.

  8. 某大跨度隧道支护破坏原因分析%Analysis of Support Failures of a Large-span Tunnel

    Institute of Scientific and Technical Information of China (English)

    董新平

    2011-01-01

    Back-analysis was conducted to determine internal tunnel forces causing support failures of a large-span railway station tunnel excavated by double -side heading method on the basis of measured horizontal convergence movements. Results demonstrated that excessive local deformations of the diaphragm walls at the lower bench level occurred and the subsequent heading excavation greatly affected the temporary support structure. The temporary support structure at the lower bench sustained large bending stresses, which resulted in cracking failure. Both the axial and bending strains of the previous temporary support were larger than that of the later ones due to repeated effects of subsequent construction, and the failures were more serious.%文章针对某采用双侧壁导洞法施工的大跨隧道在导洞施工过程中的临时支护破坏现象,结合实际的净空收敛监控数据对支护内力进行了反分析,重点就支护破坏形成原因进行了分析.分析结果表明:当导洞下台阶开挖时,导洞内壁会产生较大的水平变形,且后续导洞开挖对先开挖侧导洞临时支护变形影响较大;下台阶位置处临时支护以承受弯曲应力为主,受力状态较为不利,易因弯曲应力过大而导致拉裂破坏;先行开挖侧导洞临时支护在后开挖侧导洞施工的反复影响下,无论是轴向应变还是弯曲应变均明显高于后开挖侧导洞,破坏程度因此也更为严重.

  9. CARES/LIFE Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program

    Science.gov (United States)

    Nemeth, Noel N.; Powers, Lynn M.; Janosik, Lesley A.; Gyekenyesi, John P.

    2003-01-01

    This manual describes the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction (CARES/LIFE) computer program. The program calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/or proof test loading. CARES/LIFE is an extension of the CARES (Ceramic Analysis and Reliability Evaluation of Structures) computer program. The program uses results from MSC/NASTRAN, ABAQUS, and ANSYS finite element analysis programs to evaluate component reliability due to inherent surface and/or volume type flaws. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing the power law, Paris law, or Walker law. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled by using either the principle of independent action (PIA), the Weibull normal stress averaging method (NSA), or the Batdorf theory. Inert strength and fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. The probabilistic time-dependent theories used in CARES/LIFE, along with the input and output for CARES/LIFE, are described. Example problems to demonstrate various features of the program are also included.

  10. Uncertainty Assessment in Life Cycle Cost Analysis.

    Science.gov (United States)

    1985-05-01

    of this report) Unclassified 15. DECL ASSI FICATION/ DOWNGRADING SCHEDULE 1S. DISTRIBUTION STATEMENT (of this Report) Approved for public release...data base oriented. 7. Risk Analysis and Decision Models in the Planning of Housing Projects, by Jorge A. Machado , Report No. R72-44, Structures...1979). Lewis, L., "Range Estimating -- Managing Uncertainty," AACE Bulletin, Vol. 19, No. 6, Nov/Dec 1977. Machado , J. A., "Risk Analysis and Decision

  11. Vortex induced vibrations of free span pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Koushan, Kamran

    2009-07-01

    on the flow pattern around the cylinder during oscillation. Hydrodynamic parameters may therefore vary when the pipe is close to the seabed. In the present work, the influence from spatial varying current profiles is investigated for both single and multiple span pipeline. It is shown that the difference between using uniform and spatial varying current profiles is significant for some current speeds. It is also shown that use of spatial varying current profiles can be even more important for multiple span pipeline. The comparison of VIVANA analysis results with MARINTEK test results has been given. It shows VIVANA predicts the cross-flow response generally much higher than the test measurements, especially for the higher mode responses. To improve understanding of this phenomena, the VIVANA model was tuned to the test model and results are compared in different cases. Attempts were made to obtain a better agreement by adjusting some of the input parameters to VIVANA. The reference point is tuned by changing various hydrodynamic properties, i.e. C{sub L} St and added mass. The response frequencies are also tuned in order to have a better agreement on the results. It is been concluded that the method used here by VIVANA is not able to describe VIV for free spanning pipelines adequately. It is not possible to find a set of parameter in a rational way that will give reasonably correct results. The discrepancy between the analysis and test results are highlighted which confirms the interaction between the in-line and cross-flow vibrations. Discussions are given and addressed on different reasons which may cause this phenomena. An improved strategy for non-linear analysis of free span pipeline is outlined. Time domain analysis for free span pipeline has been performed. The difference between time and frequency domain analysis has also been investigated by varying boundary conditions, pipe properties and axial tension. A significant difference is shown between results from

  12. Spanning Tree Based Attribute Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Jorge, Cordero Hernandez

    2009-01-01

    inconsistent edges from a maximum spanning tree by starting appropriate initial modes, therefore generating stable clusters. It discovers sound clusters through simple graph operations and achieves significant computational savings. We compare the Star Discovery algorithm against earlier attribute clustering...

  13. Seismic performance evaluation for super-long span cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    Ye Aijun; Wu Shouchang

    2009-01-01

    Based on the capacity/demand (C/D) analysis of bridge components, and life cycle and performance based seismic design principles, a practical approach is developed for the seismic performance evaluation of super-long span cable-stayed bridges. According to the approach, the seismic performance evaluation of the Sutong Bridge, which is a cable-stayed bridge with a main span of 1 088 m, is completed, and the practicality of the approach is validated. The earthquake resistance level for super-long span cable-stayed bridges is discussed, including the earthquake level, its corresponding structural performance and check indices. And a set of formula for capacity/demand ratio calculation of bridge components is proposed.

  14. Nursing Process. Nursing: Basic Needs I. Nursing: Basic Needs II. Nursing through the Life Span. Entry into Professional Nursing. A Basic Course Outline (College Freshmen) for Nursing. A Four Year "2+2" Articulated Curriculum for the Occupation of Nursing.

    Science.gov (United States)

    Maddox, Gaylon; And Others

    This course outline provides materials for third-year courses in a "2+2" curriculum for the occupation of registered nurse. It is part of a planned and articulated 4-year curriculum that spans the junior and senior years of high school and the freshman and sophomore years of the postsecondary institution. Introductory materials include:…

  15. Validation of a hybrid life-cycle inventory analysis method.

    Science.gov (United States)

    Crawford, Robert H

    2008-08-01

    The life-cycle inventory analysis step of a life-cycle assessment (LCA) may currently suffer from several limitations, mainly concerned with the use of incomplete and unreliable data sources and methods of assessment. Many past LCA studies have used traditional inventory analysis methods, namely process analysis and input-output analysis. More recently, hybrid inventory analysis methods have been developed, combining these two traditional methods in an attempt to minimise their limitations. In light of recent improvements, these hybrid methods need to be compared and validated, as these too have been considered to have several limitations. This paper evaluates a recently developed hybrid inventory analysis method which aims to improve the limitations of previous methods. It was found that the truncation associated with process analysis can be up to 87%, reflecting the considerable shortcomings in the quantity of process data currently available. Capital inputs were found to account for up to 22% of the total inputs to a particular product. These findings suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependent upon data quality and availability. The use of input-output data assists in improving the system boundary completeness of life-cycle inventories. However, the use of input-output analysis alone does not always provide an accurate model for replacing process data. Further improvements in the quantity of process data currently available are needed to increase the reliability of life-cycle inventories.

  16. Alternative materials for desert buildings: a comparative life cycle energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pearlmutter, D.; Freidin, C.; Huberman, N. [Institutes for Desert Research, Ben-Gurion University of the Negev, (Israel)

    2007-03-15

    This study examines the potential life-cycle energy savings that may be achieved by combining an innovative alternative building material and a bioclimatic approach to building design under the distinctive environmental conditions of a desert region. A residential building in the Negev region of Israel is used as a model for the assessment. Designed with a number of climatically-responsive design strategies and conventional concrete-based materials, the building was energy-independent in terms of summer cooling and had only modest requirements for winter heating. As a second step to the assessment, the integration of an alternative building material based on industrial waste and local raw materials in the building's walls was considered through thermal simulation. The alternative materials are produced through a process developed to make productive utilization of fly-ash from oil shale and coal combustion. Material properties were analyzed using laboratory specimens, and it was established that high-quality building components could be produced using the developed technological procedure with standard manufacturing equipment. The consumption of both embodied and operational energy was analyzed over the building's useful life span, and this life-cycle analysis showed the clear advantage of integrating alternative materials in a building under environmental conditions in a desert environment. (Author)

  17. A型高墩大跨混凝土连续刚构桥地震反应影响分析%Impact Analysis of Seismic Response A Type High Pier and Long Span Concrete Continuous Rigid Frame Bridge

    Institute of Scientific and Technical Information of China (English)

    陈思孝; 夏修身; 李锐

    2014-01-01

    Remarkable characteristics of A type high pier and long span concrete continuous rigid frame bridge are high pier, larye span, massive girder and pier. This paper analyzes the influence of P-delta effect, the traveling wave effect on the A type high pier and long-span continuous rigid frame bridge seismic response of concrete and elastic plastic re-sponse characteristics of earthquake, it also discusses the seismic ductility design method of A type high pier and long span concrete continuous rigid frame bridge. The results showed that: A type continuous rigid frame bridge with high piers on seismic design limited ductility is reasonable, P-delta has little effect on type A high pier and long-span continu-ous rigid frame bridge’s response in earthquake, which cauld be ignared in design; traveling wave effect on the A type high pier and long-span continuous rigid frame bridge response earthquake should be combined with a specific type of bridge and bridge site selection. Reasonable seismic wave velocity and proper travelling wave speed should be selected in analysis. The research could sexve as a reference for high pier and long-span Railway Bridge design.%A型高墩大跨混凝土连续刚构桥的显著特点是墩高、跨度大、梁体及墩身质量巨大。文章分析了P-Δ效应、行波效应对A型高墩大跨混凝土连续刚构桥地震反应的影响及弹塑性地震反应特点,探讨了A型高墩大跨混凝土连续刚构桥的延性抗震设计方法。结果表明: A型高墩连续刚构桥按有限延性的抗震设计比较合理,P-Δ效应对A型高墩大跨连续刚构桥地震反应的影响较小,设计中可以忽略;行波效应对A型高墩大跨连续刚构桥地震反应的影响应结合具体的桥型、桥址场地类别,选取合理的地震动、恰当的行波速度进行分析。

  18. Response Analysis of Large-Span Steel Structure Floor under Crowd Load%大跨钢结构楼盖人群荷载响应分析

    Institute of Scientific and Technical Information of China (English)

    张志强; 马斐; 李爱群; 许金军

    2011-01-01

    Due to the complexity of the crowd activities, each person walks with different phase, stride length, frequency, weight, and start time. The crowd load is very complicated, because each person in the crowd cannot walk with completely coordination. So it's difficult to analyze the response of large span floor exactly under the actual crowd load. The structure of railway station has a large span floor with crowded load on it and the waiting passengers walk with complex characteristics. This paper uses four existing crowd load model adopted in several foreign codes and walk frequency normal distribution model which is put forward in this paper to analyze the vibration of a large span steel structure floor of a train station under crowd load at different population densities in order to simulated crowd loads more accurate, verify the correctness of the load simulation method which consider walk frequency normal distribution. Results show that the peak acceleration of the large span floor using walk frequency normal distribution model is between partial and all pedestrians synchronization model of the other four. Besides, this result is accord with large span floor vibration measurement results. At the setting conditions, the equivalent synchronous probability is 22. 33%, 37.88%and 72. 81% ,respectively. In the low population density cases,walk frequency normal distribution model has certain accuracy and the equivalent synchronous probability is close to the measurement results of abroad.Confirmed the correctness of the load simulation method of walk frequency normal distribution model and provide theory basis for practical engineering design. With the population density increases, pedestrians can not walk freely, the forward movement speed get slow and walk frequency reduce and synchronous probability increase. Then the dynamic response of large span floor has a process of increases in the first and then reduce gradually with the with the population density

  19. Toward applied behavior analysis of life aloft

    Science.gov (United States)

    Brady, J. V.

    1990-01-01

    This article deals with systems at multiple levels, at least from cell to organization. It also deals with learning, decision making, and other behavior at multiple levels. Technological development of a human behavioral ecosystem appropriate to space environments requires an analytic and synthetic orientation, explicitly experimental in nature, dictated by scientific and pragmatic considerations, and closely approximating procedures of established effectiveness in other areas of natural science. The conceptual basis of such an approach has its roots in environmentalism which has two main features: (1) knowledge comes from experience rather than from innate ideas, divine revelation, or other obscure sources; and (2) action is governed by consequences rather than by instinct, reason, will, beliefs, attitudes or even the currently fashionable cognitions. Without an experimentally derived data base founded upon such a functional analysis of human behavior, the overgenerality of "ecological systems" approaches render them incapable of ensuring the successful establishment of enduring space habitats. Without an experimentally derived function account of individual behavioral variability, a natural science of behavior cannot exist. And without a natural science of behavior, the social sciences will necessarily remain in their current status as disciplines of less than optimal precision or utility. Such a functional analysis of human performance should provide an operational account of behavior change in a manner similar to the way in which Darwin's approach to natural selection accounted for the evolution of phylogenetic lines (i.e., in descriptive, nonteleological terms). Similarly, as Darwin's account has subsequently been shown to be consonant with information obtained at the cellular level, so too should behavior principles ultimately prove to be in accord with an account of ontogenetic adaptation at a biochemical level. It would thus seem obvious that the most

  20. Spanning Trees and bootstrap reliability estimation in correlation based networks

    CERN Document Server

    Tumminello, M; Lillo, F; Micciché, S; Mantegna, R N

    2006-01-01

    We introduce a new technique to associate a spanning tree to the average linkage cluster analysis. We term this tree as the Average Linkage Minimum Spanning Tree. We also introduce a technique to associate a value of reliability to links of correlation based graphs by using bootstrap replicas of data. Both techniques are applied to the portfolio of the 300 most capitalized stocks traded at New York Stock Exchange during the time period 2001-2003. We show that the Average Linkage Minimum Spanning Tree recognizes economic sectors and sub-sectors as communities in the network slightly better than the Minimum Spanning Tree does. We also show that the average reliability of links in the Minimum Spanning Tree is slightly greater than the average reliability of links in the Average Linkage Minimum Spanning Tree.

  1. Life cycle cost analysis of commercial buildings with energy efficient approach

    Directory of Open Access Journals (Sweden)

    Nilima N. Kale

    2016-09-01

    Full Text Available In any construction project, cost effectiveness plays a crucial role. The Life Cycle Cost (LCC analysis provides a method of determining entire cost of a structure over its expected life along with operational and maintenance cost. LCC can be improved by adopting alternative modern techniques without much alteration in the building. LCC effectiveness can be calculated at various stages of entire span of the building. Moreover this provides decision makers with the financial information necessary for maintaining, improving, and constructing facilities. Financial benefits associated with energy use can also be calculated using LCC analysis. In the present work, case study of two educational buildings has been considered. The LCC of these buildings has been calculated with existing condition and with proposed energy efficient approach (EEA using net present value method. A solar panel having minimum capacity as well as solar panel with desired capacity as per the requirements of the building has been suggested. The comparison of LCC of existing structure with proposed solar panel system shows that 4% of cost can be reduced in case of minimum capacity solar panel and 54% cost can be reduced for desired capacity solar panel system, along with other added advantages of solar energy.

  2. Spanning quadrangulations of triangulated surfaces

    DEFF Research Database (Denmark)

    Kündgen, André; Thomassen, Carsten

    2017-01-01

    In this paper we study alternating cycles in graphs embedded in a surface. We observe that 4-vertex-colorability of a triangulation on a surface can be expressed in terms of spanninq quadrangulations, and we establish connections between spanning quadrangulations and cycles in the dual graph which...... are noncontractible and alternating with respect to a perfect matching. We show that the dual graph of an Eulerian triangulation of an orientable surface other than the sphere has a perfect matching M and an M-alternating noncontractible cycle. As a consequence, every Eulerian triangulation of the torus has...... a nonbipartite spanning quadrangulation. For an Eulerian triangulation G of the projective plane the situation is different: If the dual graph G∗ is nonbipartite, then G∗ has no noncontractible alternating cycle, and all spanning quadrangulations of G are bipartite. If the dual graph G∗ is bipartite, then it has...

  3. Dynamic analysis and numerical experiments for balancing of the continuous single-disc and single-span rotor-bearing system

    Science.gov (United States)

    Wang, Aiming; Cheng, Xiaohan; Meng, Guoying; Xia, Yun; Wo, Lei; Wang, Ziyi

    2017-03-01

    Identification of rotor unbalance is critical for normal operation of rotating machinery. The single-disc and single-span rotor, as the most fundamental rotor-bearing system, has attracted research attention over a long time. In this paper, the continuous single-disc and single-span rotor is modeled as a homogeneous and elastic Euler-Bernoulli beam, and the forces applied by bearings and disc on the shaft are considered as point forces. A fourth-order non-homogeneous partial differential equation set with homogeneous boundary condition is solved for analytical solution, which expresses the unbalance response as a function of position, rotor unbalance and the stiffness and damping coefficients of bearings. Based on this analytical method, a novel Measurement Point Vector Method (MPVM) is proposed to identify rotor unbalance while operating. Only a measured unbalance response registered for four selected cross-sections of the rotor-shaft under steady-state operating conditions is needed when using the method. Numerical simulation shows that the detection error of the proposed method is very small when measurement error is negligible. The proposed method provides an efficient way for rotor balancing without test runs and external excitations.

  4. Numerical Analysis on the Large Span Beam in Subway Station Entrance%地铁出入口大跨度接口梁数值分析

    Institute of Scientific and Technical Information of China (English)

    林蓼

    2012-01-01

    By means of an FE space model, the internal force of large span beam at subway station entrance have been found and compared with the internal force of the traditional planar model, the result shows that the internal force of the space calculation model is closer to the real strained condition than to the traditional planar model. The torque moment of the large span beam at metro entrance is not the dominant element, while the bending moment is similar to the elastomeric supported beam.%建立空间计算模型对地铁出入口大跨度接口梁的内力等进行数值分析,提出接口梁空间计算模型及其内力计算结果,对比传统平面简化计算模型的内力结果,得知空间计算模型结果更接近接口梁的真实受力状态,接口梁的扭矩不是受力的控制性因素,而接口梁的弯矩接近弹性支座梁的弯矩.

  5. Some Aspects Regarding the Analysis of the Life Insurance Market

    Directory of Open Access Journals (Sweden)

    Constantin Anghelache

    2009-03-01

    Full Text Available This paper aims to draw-up an analysis of the life insurance market in Romania. This survey is drawn up for the period 2003-2006 and the data used for this analysis were taken over from the Annual Reports published by the Insurance Supervision Commission. Life insurance market in Romania is a steady growing market as a result of the economic growth and the purchase power but is still far away from the development stage of the European markets.

  6. A Distributed Spanning Tree Algorithm

    DEFF Research Database (Denmark)

    Johansen, Karl Erik; Jørgensen, Ulla Lundin; Nielsen, Sven Hauge

    We present a distributed algorithm for constructing a spanning tree for connected undirected graphs. Nodes correspond to processors and edges correspond to two-way channels. Each processor has initially a distinct identity and all processors perform the same algorithm. Computation as well...... as communication is asynchronous. The total number of messages sent during a construction of a spanning tree is at most 2E+3NlogN. The maximal message size is loglogN+log(maxid)+3, where maxid is the maximal processor identity....

  7. A distributed spanning tree algorithm

    DEFF Research Database (Denmark)

    Johansen, Karl Erik; Jørgensen, Ulla Lundin; Nielsen, Svend Hauge

    1988-01-01

    We present a distributed algorithm for constructing a spanning tree for connected undirected graphs. Nodes correspond to processors and edges correspond to two way channels. Each processor has initially a distinct identity and all processors perform the same algorithm. Computation as well...... as communication is asyncronous. The total number of messages sent during a construction of a spanning tree is at most 2E+3NlogN. The maximal message size is loglogN+log(maxid)+3, where maxid is the maximal processor identity....

  8. A Distributed Spanning Tree Algorithm

    DEFF Research Database (Denmark)

    Johansen, Karl Erik; Jørgensen, Ulla Lundin; Nielsen, Sven Hauge

    We present a distributed algorithm for constructing a spanning tree for connected undirected graphs. Nodes correspond to processors and edges correspond to two-way channels. Each processor has initially a distinct identity and all processors perform the same algorithm. Computation as well...... as communication is asynchronous. The total number of messages sent during a construction of a spanning tree is at most 2E+3NlogN. The maximal message size is loglogN+log(maxid)+3, where maxid is the maximal processor identity....

  9. Life cycle assessment analysis of supercritical coal power units

    Science.gov (United States)

    Ziębik, Andrzej; Hoinka, Krzysztof; Liszka, Marcin

    2010-09-01

    This paper presents the Life Cycle Assessment (LCA) analysis concerning the selected options of supercritical coal power units. The investigation covers a pulverized power unit without a CCS (Carbon Capture and Storage) installation, a pulverized unit with a "post-combustion" installation (MEA type) and a pulverized power unit working in the "oxy-combustion" mode. For each variant the net electric power amounts to 600 MW. The energy component of the LCA analysis has been determined. It describes the depletion of non-renewable natural resources. The energy component is determined by the coefficient of cumulative energy consumption in the life cycle. For the calculation of the ecological component of the LCA analysis the cumulative CO2 emission has been applied. At present it is the basic emission factor for the LCA analysis of power plants. The work also presents the sensitivity analysis of calculated energy and ecological factors.

  10. Authenticity, life satisfaction, and distress: a longitudinal analysis.

    Science.gov (United States)

    Boyraz, Güler; Waits, J Brandon; Felix, Victoria A

    2014-07-01

    The purpose of the present study was to examine the reciprocal relationships between authenticity and measures of life satisfaction and distress using a 2-wave panel study design. Data were collected from 232 college students attending 2 public universities. Structural equation modeling was used to analyze the data. The results of the cross-lagged panel analysis indicated that after controlling for temporal stability, initial authenticity (Time 1) predicted later distress and life satisfaction (Time 2). Specifically, higher levels of authenticity at Time 1 were associated with increased life satisfaction and decreased distress at Time 2. Neither distress nor life satisfaction at Time 1 significantly predicted authenticity at Time 2. However, the relationship between Time 1 distress and Time 2 authenticity was not significantly different from the relationship between Time 1 authenticity and Time 2 distress. Results are discussed in light of humanistic-existential theories and the empirical research on well-being.

  11. Infrastructures and Life-Cycle Cost-Benefit Analysis

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    2012-01-01

    Design and maintenance of infrastructures using Life-Cycle Cost-Benefit analysis is discussed in this paper with special emphasis on users costs. This is for several infrastructures such as bridges, highways etc. of great importance. Repair or/and failure of infrastructures will usually result in...

  12. Integrated Lifing Analysis of a Film-Cooled Turbine Blade

    Science.gov (United States)

    2003-02-01

    not available, and data for an isotropic superalloy were used. Obviously the inaccuracy of the FE calculations will be larger when an inaccurate...complex problem as a first stage turbine blade analysis to demonstrate your modelling tool. Have you considered applying the tool to lifing a disc

  13. Methods for global sensitivity analysis in life cycle assessment

    NARCIS (Netherlands)

    Groen, Evelyne A.; Bokkers, Eddy; Heijungs, Reinout; Boer, de Imke J.M.

    2017-01-01

    Purpose: Input parameters required to quantify environmental impact in life cycle assessment (LCA) can be uncertain due to e.g. temporal variability or unknowns about the true value of emission factors. Uncertainty of environmental impact can be analysed by means of a global sensitivity analysis to

  14. U.S. EPA'S RESEARCH ON LIFE-CYCLE ANALYSIS

    Science.gov (United States)

    Life-cycle analysis (LCA) consists of looking at a product, process or activity from its inception through its completion. or consumer products, this includes the stages of raw material acquisition, manufacturing and fabrication, distribution, consumer use/reuse and final disposa...

  15. Analysis within the systems development life-cycle

    CERN Document Server

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle, Book 3: Activity Analysis - The Deliverables provides a comprehensive coverage of the deliverables of activity analysis. The book also details purpose of each deliverable in the context of the next tasks in the systems development cycle (SDC). The text first covers the concept of deliverables and the benefits of making deliverables visible. In the second chapter, the book introduces the main concepts and diagrammatic techniques of activity analysis. The third chapter deals with the important classes or categories of concept, while the fourth

  16. Life cycle analysis of geothermal power generation with supercritical carbon dioxide

    Science.gov (United States)

    Frank, Edward D.; Sullivan, John L.; Wang, Michael Q.

    2012-09-01

    Life cycle analysis methods were employed to model the greenhouse gas emissions and fossil energy consumption associated with geothermal power production when supercritical carbon dioxide (scCO2) is used instead of saline geofluids to recover heat from below ground. Since a significant amount of scCO2 is sequestered below ground in the process, a constant supply is required. We therefore combined the scCO2 geothermal power plant with an upstream coal power plant that captured a portion of its CO2 emissions, compressed it to scCO2, and transported the scCO2 by pipeline to the geothermal power plant. Emissions and energy consumption from all operations spanning coal mining and plant construction through power production were considered, including increases in coal use to meet steam demand for the carbon capture. The results indicated that the electricity produced by the geothermal plant more than balanced the increase in energy use resulting from carbon capture at the coal power plant. The effective heat rate (BTU coal per total kW h of electricity generated, coal plus geothermal) was comparable to that of traditional coal, but the ratio of life cycle emissions from the combined system to that of traditional coal was 15% when 90% carbon capture efficiency was assumed and when leakage from the surface was neglected. Contributions from surface leakage were estimated with a simple model for several hypothetical surface leakage rates.

  17. Dynamic Path Analysis in Life-Course Epidemiology

    DEFF Research Database (Denmark)

    Gamborg, Michael Orland; Boje Jensen, Gorm; Sørensen, Thorkild I.A.;

    2011-01-01

    it works through other risk factors. In this paper, the dynamic path analysis model is presented as a tool to analyze these dynamic mechanisms in life-course epidemiology. A key feature of dynamic path analysis is its ability to decompose the total effect of a risk factor into a direct effect (not mediated...... BMI on the risk of CHD is decomposed into a direct effect and indirect effects going through later BMI, concurrent SBP, or later SBP. In conclusion, dynamic path analysis is a flexible tool that by the decomposition of effects can be used to increase the understanding of mechanisms that underlie......Life-course epidemiology seeks to better understand the mechanisms that lead to the development of chronic diseases. An example is the mechanism leading from body size to coronary heart disease (CHD); one way to acquire a better understanding of this mechanism is to investigate to what extent...

  18. Multilevel survival analysis of health inequalities in life expectancy

    Directory of Open Access Journals (Sweden)

    Merlo Juan

    2009-08-01

    Full Text Available Abstract Background The health status of individuals is determined by multiple factors operating at both micro and macro levels and the interactive effects of them. Measures of health inequalities should reflect such determinants explicitly through sources of levels and combining mean differences at group levels and the variation of individuals, for the benefits of decision making and intervention planning. Measures derived recently from marginal models such as beta-binomial and frailty survival, address this issue to some extent, but are limited in handling data with complex structures. Beta-binomial models were also limited in relation to measuring inequalities of life expectancy (LE directly. Methods We propose a multilevel survival model analysis that estimates life expectancy based on survival time with censored data. The model explicitly disentangles total health inequalities in terms of variance components of life expectancy compared to the source of variation at the level of individuals in households and parishes and so on, and estimates group differences of inequalities at the same time. Adjusted distributions of life expectancy by gender and by household socioeconomic level are calculated. Relative and absolute health inequality indices are derived based on model estimates. The model based analysis is illustrated on a large Swedish cohort of 22,680 men and 26,474 women aged 65–69 in 1970 and followed up for 30 years. Model based inequality measures are compared to the conventional calculations. Results Much variation of life expectancy is observed at individual and household levels. Contextual effects at Parish and Municipality level are negligible. Women have longer life expectancy than men and lower inequality. There is marked inequality by the level of household socioeconomic status measured by the median life expectancy in each socio-economic group and the variation in life expectancy within each group. Conclusion Multilevel

  19. Leaf life span and nitrogen content in semideciduous forest tree species (Croton priscus and Hymenaea courbaril Duração da vida da folha e conteúdo de nitrogênio em espécies arbóreas (Croton priscus e Hymenaea courbaril de floresta semidecídua

    Directory of Open Access Journals (Sweden)

    Claudia Regina Baptista Haddad

    2004-01-01

    Full Text Available In comparison to deciduous species, evergreen plants have lower leaf nutrient contents and higher leaf life span, important mechanisms for nutrient economy, allowing the colonization of low fertility soils. Strategies to conserve nitrogen in two semideciduous tropical forest tree species, with different leaf life spans were analyzed. The hypothesis was the fact that the two species would present different nitrogen conservation mechanisms in relation to chemical (total nitrogen, protein, chlorophyll, and proteolytic activity, functional (leaf life span, N-use efficiency, and N-resorption efficiency, morphological (specific leaf mass leaf characteristics, and total nitrogen in the soil. Hymenaea courbaril L. presented lower nitrogen compounds in leaves, longer leaf life span, higher N-use efficiency, and higher specific leaf mass, while absorbing proportionally less nitrogen from the soil than Croton priscus Croizat. These characteristics can contribute for a better nitrogen economy strategy of H. courbaril. No relationship was found between leaf life span and N resorption efficiency, nor between leaf life span, protease activity and nitrogen mobilization. The electrophoretic profiles of proteolytic enzymes in young leaves of the two species presented more bands with enzymatic activity than other kinds of leaves.Comparadas a espécies decíduas, as sempre-verdes têm menos nutrientes nas folhas, que também são mais longevas. Estes mecanismos são importantes para economia de nutrientes, e permitem a colonização de solos com baixa fertilidade. Foram analisadas estratégias de conservação de nitrogênio em duas espécies de floresta semidecídua, que aparentemente apresentavam longevidades foliares diferentes. Para isto foram comparados mecanismos químicos (concentrações de nitrogênio total, de proteína e clorofila e atividade proteolítica, funcionais (duração de vida das folhas, eficiência do uso de nitrogênio e eficiência de

  20. Idiopathic Parkinson's disease: vocal and quality of life analysis

    Directory of Open Access Journals (Sweden)

    Luiza Furtado e Silva

    2012-09-01

    Full Text Available OBJECTIVE: To compare voice and life quality of male patients with idiopathic Parkinson's disease, with individuals without disease (Control Group. METHODS: A cross-sectional study that evaluated the voice of individuals with Parkinson's disease, the group was composed of 27 subjects, aged from 39 to 79 years-old (average 59.96. The Control Group was matched on sex and age. Participants underwent voice recording. Perceptual evaluation was made using GRBASI scale, which considers G as the overall degree of dysphonia, R as roughness, B as breathiness, A as asthenia, S as strain and I as instability. The acoustic parameters analyzed were: fundamental frequency, jitter, shimmer, and harmonic to noise ratio (NHR. For vocal self-perception analysis, we used the Voice Related Quality of Life protocol. RESULTS: Fundamental frequency and jitter presented higher values in the Parkinson's group. NHR values were higher in the Control Group. Perceptual analysis showed a deviation ranging. The vocal disorder self-perception demonstrated a worse impact on quality of life. CONCLUSIONS: Individuals with Parkinson's disease have an altered voice quality and a negative impact on quality of life.