WorldWideScience

Sample records for chronological life span

  1. Quantifying yeast chronological life span by outgrowth of aged cells.

    Science.gov (United States)

    Murakami, Christopher; Kaeberlein, Matt

    2009-01-01

    The budding yeast Saccharomyces cerevisiae has proven to be an important model organism in the field of aging research. The replicative and chronological life spans are two established paradigms used to study aging in yeast. Replicative aging is defined as the number of daughter cells a single yeast mother cell produces before senescence; chronological aging is defined by the length of time cells can survive in a non-dividing, quiescence-like state. We have developed a high-throughput method for quantitative measurement of chronological life span. This method involves aging the cells in a defined medium under agitation and at constant temperature. At each age-point, a sub-population of cells is removed from the aging culture and inoculated into rich growth medium. A high-resolution growth curve is then obtained for this sub-population of aged cells using a Bioscreen C MBR machine. An algorithm is then applied to determine the relative proportion of viable cells in each sub-population based on the growth kinetics at each age-point. This method requires substantially less time and resources compared to other chronological lifespan assays while maintaining reproducibility and precision. The high-throughput nature of this assay should allow for large-scale genetic and chemical screens to identify novel longevity modifiers for further testing in more complex organisms. PMID:19421136

  2. Yeast MRX deletions have short chronological life span and more triacylglycerols.

    Science.gov (United States)

    Kanagavijayan, Dhanabalan; Rajasekharan, Ram; Srinivasan, Malathi

    2016-02-01

    Saccharomyces cerevisiae is an excellent model organism for lipid research. Here, we have used yeast haploid RAdiation Damage (RAD) deletion strains to study life span and lipid storage patterns. RAD genes are mainly involved in DNA repair mechanism and hence, their deletions have resulted in shorter life span. Viable RAD mutants were screened for non-polar lipid content, and some of the mutants showed significantly high amounts of triacylglycerol (TAG) and steryl ester, besides short chronological life span. Among these, RAD50, MRE11 and XRS2 form a complex, MRX that is involved in homologous recombination that showed an increase in the amount of TAG. Microarray data of single MRX deletions revealed that besides DNA damage signature genes, lipid metabolism genes are also differentially expressed. Lipid biosynthetic genes (LPP1, SLC1) were upregulated and lipid hydrolytic gene (TGL3) was downregulated. We observed that rad50Δ, mre11Δ, xrs2Δ and mrxΔ strains have high number of lipid droplets (LDs) with fragmented mitochondria. These mutants have a short chronological life span compared to wild type. Aged wild-type cells also accumulated TAG with LDs of ∼2.0 μm in diameter. These results suggest that TAG accumulation and big size LDs could be possible markers for premature or normal aging. PMID:26678749

  3. Altered Lipid Synthesis by Lack of Yeast Pah1 Phosphatidate Phosphatase Reduces Chronological Life Span.

    Science.gov (United States)

    Park, Yeonhee; Han, Gil-Soo; Mileykovskaya, Eugenia; Garrett, Teresa A; Carman, George M

    2015-10-16

    In Saccharomyces cerevisiae, Pah1 phosphatidate phosphatase, which catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol, plays a crucial role in the synthesis of the storage lipid triacylglycerol. This evolutionarily conserved enzyme also plays a negative regulatory role in controlling de novo membrane phospholipid synthesis through its consumption of phosphatidate. We found that the pah1Δ mutant was defective in the utilization of non-fermentable carbon sources but not in oxidative phosphorylation; the mutant did not exhibit major changes in oxygen consumption rate, mitochondrial membrane potential, F1F0-ATP synthase activity, or gross mitochondrial morphology. The pah1Δ mutant contained an almost normal complement of major mitochondrial phospholipids with some alterations in molecular species. Although oxidative phosphorylation was not compromised in the pah1Δ mutant, the cellular levels of ATP in quiescent cells were reduced by 2-fold, inversely correlating with a 4-fold increase in membrane phospholipids. In addition, the quiescent pah1Δ mutant cells had 3-fold higher levels of mitochondrial superoxide and cellular lipid hydroperoxides, had reduced activities of superoxide dismutase 2 and catalase, and were hypersensitive to hydrogen peroxide. Consequently, the pah1Δ mutant had a shortened chronological life span. In addition, the loss of Tsa1 thioredoxin peroxidase caused a synthetic growth defect with the pah1Δ mutation. The shortened chronological life span of the pah1Δ mutant along with its growth defect on non-fermentable carbon sources and hypersensitivity to hydrogen peroxide was suppressed by the loss of Dgk1 diacylglycerol kinase, indicating that the underpinning of pah1Δ mutant defects was the excess synthesis of membrane phospholipids. PMID:26338708

  4. Mitochondrial dysfunction increases oxidative stress and decreases chronological life span in fission yeast.

    Directory of Open Access Journals (Sweden)

    Alice Zuin

    Full Text Available BACKGROUND: Oxidative stress is a probable cause of aging and associated diseases. Reactive oxygen species (ROS originate mainly from endogenous sources, namely the mitochondria. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the effect of aerobic metabolism on oxidative damage in Schizosaccharomyces pombe by global mapping of those genes that are required for growth on both respiratory-proficient media and hydrogen-peroxide-containing fermentable media. Out of a collection of approximately 2700 haploid yeast deletion mutants, 51 were sensitive to both conditions and 19 of these were related to mitochondrial function. Twelve deletion mutants lacked components of the electron transport chain. The growth defects of these mutants can be alleviated by the addition of antioxidants, which points to intrinsic oxidative stress as the origin of the phenotypes observed. These respiration-deficient mutants display elevated steady-state levels of ROS, probably due to enhanced electron leakage from their defective transport chains, which compromises the viability of chronologically-aged cells. CONCLUSION/SIGNIFICANCE: Individual mitochondrial dysfunctions have often been described as the cause of diseases or aging, and our global characterization emphasizes the primacy of oxidative stress in the etiology of such processes.

  5. Life-spanning murine gene expression profiles in relation to chronological and pathological aging in multiple organs

    Science.gov (United States)

    Kuiper, Raoul V; van der Hoeven, Tessa V; Wackers, P.F.K.; Robinson, Joke; van der Horst, Gijsbertus TJ; Dollé, Martijn ET; Vijg, Jan; Breit, Timo M; Hoeijmakers, Jan HJ; van Steeg, Harry

    2013-01-01

    Summary Aging and age-related pathology is a result of a still incompletely-understood intricate web of molecular and cellular processes. We present a C57BL/6J female mice in vivo aging study of five organs (liver, kidney, spleen, lung and brain), in which we compare genome-wide gene expression profiles during chronological aging with pathological changes throughout the entire murine lifespan (13, 26, 52, 78, 104 and 130 weeks). Relating gene expression changes to chronological aging revealed many differentially expressed genes (DEGs) and altered gene-sets (AGSs) were found in most organs, indicative of intra-organ generic aging processes. However, only ≤ 1% of these DEGs are found in all organs. For each organ, at least one of 18 tested pathological parameters showed a good age-predictive value, albeit with much inter- and intra-individual (organ) variation. Relating gene expression changes to pathology-related aging revealed correlated genes and gene-sets, which made it possible to characterize the difference between biological and chronological aging. In liver, kidney and brain, a limited number of overlapping pathology-related AGSs were found. Immune responses appeared to be common, yet the changes were specific in most organs. Furthermore, changes were observed in energy homeostasis, reactive oxygen species, cell cycle, cell motility and DNA damage. Comparison of chronological and pathology-related AGSs revealed substantial overlap and interesting differences. For example, the presence of immune processes in liver pathology-related AGSs which were not detected in chronological aging. The many cellular processes that are only found employing aging–related pathology could provide important new insights into the progress of aging. PMID:23795901

  6. 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.

  7. Thermodynamics and life span estimation

    International Nuclear Information System (INIS)

    In this study, the life span of people living in seven regions of Turkey is estimated by applying the first and second laws of thermodynamics to the human body. The people living in different regions of Turkey have different food habits. The first and second laws of thermodynamics are used to calculate the entropy generation rate per unit mass of a human due to the food habits. The lifetime entropy generation per unit mass of a human was previously found statistically. The two entropy generations, lifetime entropy generation and entropy generation rate, enable one to determine the life span of people living in seven regions of Turkey with different food habits. In order to estimate the life span, some statistics of Turkish Statistical Institute regarding the food habits of the people living in seven regions of Turkey are used. The life spans of people that live in Central Anatolia and Eastern Anatolia regions are the longest and shortest, respectively. Generally, the following inequality regarding the life span of people living in seven regions of Turkey is found: Eastern Anatolia < Southeast Anatolia < Black Sea < Mediterranean < Marmara < Aegean < Central Anatolia. - Highlights: • The first and second laws of thermodynamics are applied to the human body. • The entropy generation of a human due to his food habits is determined. • The life span of Turks is estimated by using the entropy generation method. • Food habits of a human have effect on his life span

  8. Loneliness across the life span

    NARCIS (Netherlands)

    Qualter, P.; Vanhalst, J.; Harris, R.; Roekel, G.H. van; Lodder, G.M.A.; Bangee, M.; Maes, M.; Verhagen, M.

    2015-01-01

    Most people have experienced loneliness and have been able to overcome it to reconnect with other people. In the current review, we provide a life-span perspective on one component of the evolutionary theory of lonelinessa component we refer to as the reaffiliation motive (RAM). The RAM represents t

  9. Loneliness Across the Life Span

    NARCIS (Netherlands)

    Qualter, Pamela; Vanhalst, Janne; Harris, Rebecca; Van Roekel, Eeske; Lodder, Gerine; Bangee, Munirah; Maes, Marlies; Verhagen, Maaike

    2015-01-01

    Most people have experienced loneliness and have been able to overcome it to reconnect with other people. In the current review, we provide a life-span perspective on one component of the evolutionary theory of lonelinessa component we refer to as the reaffiliation motive (RAM). The RAM represents t

  10. Loneliness across the life span.

    Science.gov (United States)

    Qualter, Pamela; Vanhalst, Janne; Harris, Rebecca; Van Roekel, Eeske; Lodder, Gerine; Bangee, Munirah; Maes, Marlies; Verhagen, Maaike

    2015-03-01

    Most people have experienced loneliness and have been able to overcome it to reconnect with other people. In the current review, we provide a life-span perspective on one component of the evolutionary theory of loneliness-a component we refer to as the reaffiliation motive (RAM). The RAM represents the motivation to reconnect with others that is triggered by perceived social isolation. Loneliness is often a transient experience because the RAM leads to reconnection, but sometimes this motivation can fail, leading to prolonged loneliness. We review evidence of how aspects of the RAM change across development and how these aspects can fail for different reasons across the life span. We conclude with a discussion of age-appropriate interventions that may help to alleviate prolonged loneliness.

  11. 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.

  12. Elevated histone expression promotes life span extension.

    Science.gov (United States)

    Feser, Jason; Truong, David; Das, Chandrima; Carson, Joshua J; Kieft, Jeffrey; Harkness, Troy; Tyler, Jessica K

    2010-09-10

    Changes to the chromatin structure accompany aging, but the molecular mechanisms underlying aging and the accompanying changes to the chromatin are unclear. Here, we report a mechanism whereby altering chromatin structure regulates life span. We show that normal aging is accompanied by a profound loss of histone proteins from the genome. Indeed, yeast lacking the histone chaperone Asf1 or acetylation of histone H3 on lysine 56 are short lived, and this appears to be at least partly due to their having decreased histone levels. Conversely, increasing the histone supply by inactivation of the histone information regulator (Hir) complex or overexpression of histones dramatically extends life span via a pathway that is distinct from previously known pathways of life span extension. This study indicates that maintenance of the fundamental chromatin structure is critical for slowing down the aging process and reveals that increasing the histone supply extends life span. PMID:20832724

  13. 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

  14. Methionine restriction and life-span control.

    Science.gov (United States)

    Lee, Byung Cheon; Kaya, Alaattin; Gladyshev, Vadim N

    2016-01-01

    Dietary restriction (DR) without malnutrition is associated with longevity in various organisms. However, it has also been shown that reduced calorie intake is often ineffective in extending life span. Selecting optimal dietary regimens for DR studies is complicated, as the same regimen may lead to different outcomes depending on genotype and environmental factors. Recent studies suggested that interventions such as moderate protein restriction with or without adequate nutrition (e.g., particular amino acids or carbohydrates) may have additional beneficial effects mediated by certain metabolic and hormonal factors implicated in the biology of aging, regardless of total calorie intake. In particular, it was shown that restriction of a single amino acid, methionine, can mimic the effects of DR and extend life span in various model organisms. We discuss the beneficial effects of a methionine-restricted diet, the molecular pathways involved, and the use of this regimen in longevity interventions.

  15. Life span study report 9, part 3

    International Nuclear Information System (INIS)

    The incidence of malignant tumors in the RERF Life Span Study (LSS) sample in Nagasaki as revealed by the Nagasaki Tumor Registry (Registry) has been investigated for the period 1959-78. No exposure status bias in data collection has been revealed. Neither method of diagnosis, reporting hospitals, nor the frequency of doubtful cases differ by exposure dose. Thus, the effect of a bias, if one exists, must be small and should not affect the interpretation of the results obtained in the present analysis. The risk of radiogenic cancer definitely increases with radiation dose for leukemia, cancer of the breast, lung, stomach, and thyroid, and suggestively so for cancer of the colon and urinary tract and multiple myeloma. However, there is no increase as yet for cancer of the esophagus, liver, gall bladder, uterus, ovary, and salivary gland, or for malignant lymphoma. For fatal cancers, these results strengthen those of the recent analysis of mortality based on death certificates on the same LSS cohort. In general, the relative risks based on incidence (that is, on Registry data) are either the same or slightly higher than those based on mortality for the same years; however, the absolute risk estimates (excess cancer per million person-year per rad) are far higher. (author)

  16. Methionine restriction beyond life-span extension.

    Science.gov (United States)

    Ables, Gene P; Hens, Julie R; Nichenametla, Sailendra N

    2016-01-01

    Dietary methionine restriction (MR) extends life span across species via various intracellular regulatory mechanisms. In rodents, MR induces resistance against adiposity, improves hepatic glucose metabolism, preserves cardiac function, and reduces body size, all of which can affect the onset of age-related diseases. Recent studies have shown that MR-affected biomarkers, such as fibroblast growth factor 21, adiponectin, leptin, cystathionine β synthase, and insulin-like growth factor 1, can potentially alter physiology. The beneficial effects of MR could be explained in part by its ability to reduce mitochondrial oxidative stress. Studies have revealed that MR can reduce reactive oxygen species that damage cells and promote cancer progression. It has been demonstrated that either MR or the targeting of specific genes in the methionine cycle could induce cell apoptosis while decreasing proliferation in several cancer models. The complete mechanism underlying the actions of MR on the cell cycle during cancer has not been fully elucidated. Epigenetic mechanisms, such as methylation and noncoding RNAs, are also possible downstream effectors of MR; future studies should help to elucidate some of these mechanisms. Despite evidence that changes in dietary methionine can affect epigenetics, it remains unknown whether epigenetics is a mechanism in MR. This review summarizes research on MR and its involvement in metabolism, cancer, and epigenetics.

  17. Data resources for life span study

    International Nuclear Information System (INIS)

    The Life Span Study sample consists originally of 82,000 A-bomb survivors who were enumerated from a nation-wide A-bomb survivors survey conducted in 1950 and 27,000 non-exposed individuals. Mortality ascertainment is essentially complete by periodic checks against Koseki, but its weakness is the inexactness of the cause of death stated on the death certificate. Some of the latter can be compensated for by collateral use of autopsy information and the data from Tissue and Tumor Registries. Updating of the Hiroshima Tumor Registry has been recently completed and no serious bias related to radiation dose was observed in the data collection for either Hiroshima or Nagasaki. Also the completeness of registration is the highest among registries in Japan. The Tumor and Tissue Registries should be very useful data resources to determine the radiation effects on non-fatal cancers i.e., thyroid and breast cancers as well as the fatal types. Lack of information on the out-migrated subjects from the two cities should be seriously considered, especially those who were of young age at the time of the bombing. Information on environmental factors other than radiation exposure, such as occupation, smoking and diet, has been collected by interviewers, mail questionnaires or record linkage with census data, since 1960. Such information is also currently obtained on a case-control basis for certain sites of cancer, such as breast, lung, colon and rectum, in this cohort. 11 references, 6 tables

  18. Life span study report, 9; 1950-78

    International Nuclear Information System (INIS)

    The RERF life span study report 9 consists of three parts and supplementary tables, each bound separately. Life span study report 9 supplementary tables, supplement to TR 12-80 and TR 5-81, are computer pritouts containing the life span study data from 1950-78. These tables are pertinent only to part 1 (Cancer mortality among atomic bomb survivors, 1950-78) and part 2 (Mortality from causes other than cancer among atomic bomb survivors, 1950-78) of Life span study report 9. This study extends Life span study report 8 by four years from 1975-78. These tables are included following data: The life span study sample, Death certificate data by cause, Malignant neoplasms, Neoplasms generally, Diseases other than neoplasms, Injuries and accidents, Summary of death certificate data. (J.P.N.)

  19. A Motivational Theory of Life-Span Development

    OpenAIRE

    Heckhausen, Jutta; Wrosch, Carsten; Schulz, Richard

    2010-01-01

    This article had four goals. First, the authors identified a set of general challenges and questions that a life-span theory of development should address. Second, they presented a comprehensive account of their Motivational Theory of Life-Span Development. They integrated the model of optimization in primary and secondary control and the action-phase model of developmental regulation with their original life-span theory of control to present a comprehensive theory of development. Third, they...

  20. 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

  1. 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 life...... span compared with daughters whose fathers did not smoke....

  2. A Motivational Theory of Life-Span Development

    Science.gov (United States)

    Heckhausen, Jutta; Wrosch, Carsten; Schulz, Richard

    2010-01-01

    This article had four goals. First, the authors identified a set of general challenges and questions that a life-span theory of development should address. Second, they presented a comprehensive account of their Motivational Theory of Life-Span Development. They integrated the model of optimization in primary and secondary control and the…

  3. Boundaries of life: estimating the life span of the biosphere

    Science.gov (United States)

    Franck, S.; Bounama, C.; von Bloh, W.

    We present a minimal model for the global carbon cycle of the Earth containing the reservoirs mantle ocean floor continental crust continental biosphere and the Kerogen as well as the aggregated reservoir ocean and atmosphere and obtain reasonable values for the present distribution of carbon in the surface reservoirs of the Earth The Earth system model for the long-term carbon cycle is specified by introducing three different types of biosphere prokaryotes eucaryotes and complex multicellular life They are characterized by different global temperature tolerance windows prokaryotes 2oC 100oC eucaryotes 5oC 45oC complex multicellular life 0oC 30oC From the Archaean to the future there always exists a prokaryotic biosphere 2 Gyr ago eucaryotic life first appears because the global surface temperature reaches the tolerance window for eucaryotes The emergence of complex multicellular life is connected with an explosive increase in biomass and a strong decrease in Cambrian global surface temperature at about 0 54 Gyr ago In the long-term future the three types of biosphere will die out in reverse sequence of their appearance For realistic values of the biotic enhancement of weathering there is no bistability in the future solutions for complex life Therefore complex organisms will not extinct by an implosion in comparison to the Cambrian explosion Eucaryotes and complex life become extinct because of too high surface temperatures in the future The ultimate life span of the biosphere is defined by the extinction of procaryotes in about 1 6 Gyr

  4. 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.

    foraminifers, life span, sediment traps, quiescent period. INTRODUCTION The morphology along with oxygen isotopic ratio of calcareous test secreted by foraminifera, unicellular marine protists with a hard covering called test, is a function of physico... estimations based on whole test ICP-MS oxygen isotope analysis of planktonic foraminifers. The life spans of foraminifers are crucial for the effective use of foraminiferal proxies for paleoclimatic reconstruction, as it will give an idea about the duration...

  5. Elders’ Attitudes toward Extending the Healthy Life Span

    OpenAIRE

    Cicirelli, Victor G.

    2011-01-01

    Despite continuing debate between anti-aging researchers seeking major life span extension and concerned gerontologists and bioethicists, elders’ views have received little research attention. Study aimed to relate elders’ attitudes toward strong life span extension to psychosocial and background factors. Participants were 109 American elders (65% women) aged 60-99 (M = 77.08, SD = 9.05). Measures included attitudes toward living long and living forever, Desired Age, Death Acceptance, Goal...

  6. Brain Weight and Life-Span in Primate Species

    OpenAIRE

    Allman, J; McLaughlin, T.; A Hakeem

    1993-01-01

    In haplorhine primates (tarsiers, monkeys, apes, and humans), there is a significant correlation between brain weight and maximum life-span when the effect of body size is removed. There is also a significant correlation in haplorhine primates between brain weight and female age at first reproduction. For strepsirhine primates (lorises and lemurs), there are no significant correlations between brain weight and either life-span or female reproductive age when the effect of body size is removed...

  7. 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.

  8. 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.

  9. 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.

  10. Genetic determinants of human health span and life span: progress and new opportunities.

    Directory of Open Access Journals (Sweden)

    George M Martin

    2007-07-01

    Full Text Available We review three approaches to the genetic analysis of the biology and pathobiology of human aging. The first and so far the best-developed is the search for the biochemical genetic basis of varying susceptibilities to major geriatric disorders. These include a range of progeroid syndromes. Collectively, they tell us much about the genetics of health span. Given that the major risk factor for virtually all geriatric disorders is biological aging, they may also serve as markers for the study of intrinsic biological aging. The second approach seeks to identify allelic contributions to exceptionally long life spans. While linkage to a locus on Chromosome 4 has not been confirmed, association studies have revealed a number of significant polymorphisms that impact upon late-life diseases and life span. The third approach remains theoretical. It would require longitudinal studies of large numbers of middle-aged sib-pairs who are extremely discordant or concordant for their rates of decline in various physiological functions. We can conclude that there are great opportunities for research on the genetics of human aging, particularly given the huge fund of information on human biology and pathobiology, and the rapidly developing knowledge of the human genome.

  11. 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…

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

    OpenAIRE

    Gilleard, C.; Higgs, P.

    2015-01-01

    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 engageme...

  13. Minocycline Effect on Life and Health Span of Drosophila Melanogaster

    OpenAIRE

    Oxenkrug, Gregory; Navrotskaya, Valeriya; Vorobyova, Lyudmila; Summergrad, Paul

    2012-01-01

    Up-regulation of kynurenine (KYN) pathway of tryptophan (TRP) was suggested as one of the mechanisms of aging and aging-associated disorders. Genetic and pharmacological impairment of TRP – KYN metabolism resulted in prolongation of life span in Drosophila models. Minocycline, an antibiotic with anti-inflammatory, antioxidant and neuroprotective properties independent of its antibacterial activity, inhibited KYN formation from TRP. Since minocycline is the only FDA approved for human use medi...

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

    OpenAIRE

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

    2011-01-01

    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 eviden...

  15. 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.

  16. From Suns to Life: A Chronological Approach to the History of Life on Earth

    CERN Document Server

    Gargaud, Muriel; López-García, Purificación; Martin, Hervé; Montmerle, Thierry; Pascal, Robert; Reisse, Jacques

    2006-01-01

    This review emerged from several interdisciplinary meetings and schools gathering a group of astronomers, geologists, biologists, and chemists, attempting to share their specialized knowledge around a common question: how did life emerge on Earth? Their ultimate goal was to provide some kind of answer as a prerequisite to an even more demanding question: is life universal? The resulting state-of-the-art articles were written by twenty-five scientists telling a not-so linear story, but on the contrary, highlighting problems, gaps, and controversies. Needless to say, this approach yielded no definitive answers to both questions. However, by adopting a chronological approach to the question of the emergence of life on Earth, the only place where we know for sure that life exists; it was possible to break down this question into several sub-topics that can be addressed by the different disciplines. The main chapters of this review present the formation and evolution of the solar system (3); the building of a habi...

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

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

    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...... 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...... 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...

  18. 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

  19. Membrane-spanning peptides and the origin of life.

    Science.gov (United States)

    Bywater, Robert P

    2009-12-01

    An explanation is given as to why membrane-spanning peptides must have been the first "information-rich" molecules in the development of life. These peptides are stabilised in a lipid bilayer membrane environment and they are preferentially made from the simplest, and likewise oldest, of the amino acids that survive today. Transmembrane peptides can exercise functions that are essential for biological systems such as signal transduction and material transport across membranes. More complex peptides possessing catalytic properties could later develop on either side of the membrane as independently folding functional units formed by extension of the protruding ends of the transmembrane peptides within an aqueous environment and thereby give rise to more of the functions that are necessary for life. But the membrane was the cradle for the development of the first information-rich biomolecules. PMID:19679140

  20. Transition: Life-Span and Life-Space Considerations for Empowerment.

    Science.gov (United States)

    Szymanski, Edna Mora

    1994-01-01

    This article integrates literature from counseling, rehabilitation, multicultural education, and special education to explain the importance of life-span considerations, including the preschool and early school years, and the life-space factors of family, culture, and community. Principles for transition interventions which promote empowerment are…

  1. Adults' conceptions of intelligence across the adult life span.

    Science.gov (United States)

    Berg, C A; Sternberg, R J

    1992-06-01

    To examine whether young, middle-aged, and older adults view the concept of intelligent person as similar or different during adulthood, 140 adults of various ages rated how likely it would be for individuals of average and exceptional intelligence at 30, 50, and 70 years of age to be engaged in behaviors previously identified by adults as characterizing adult intelligence. Adults perceived more similarity between exceptionally intelligent prototypes of closer ages (i.e., 30 and 50 and 50 and 70). Intelligence was perceived to consist of interest and ability to deal with novelty, everyday competence, and verbal competence--dimensions that were perceived to be differentially important for different-aged prototypes and by individuals of different ages. Participants' conceptions also included the idea that intelligence is malleable and that abilities differentially increase or decrease across the life span. PMID:1610512

  2. 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

  3. 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.

  4. 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. PMID:23667689

  5. 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.

  6. 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.

  7. Disentangling rectangularization and life span extension with the moving rectangle method

    DEFF Research Database (Denmark)

    Schalkwijk, Frank H; Koopman, Jacob J E; Ghariq, Eidrees;

    2016-01-01

    PURPOSE: The moving rectangle method is used to disentangle the contributions of rectangularization and life span extension to the increase in life expectancy. It requires the choice of an endpoint of the survival curve that approaches the maximum age at death. We examined the effect of choosing...... of rectangularization and life span extension to the increase in life expectancy were calculated using the moving rectangle method. RESULTS: The choice of different survival values as end points profoundly influenced the estimated contributions of rectangularization and life span extension to the increase in life...... expectancy. When choosing 0.001, rectangularization contributed most years, whereas when choosing 0.1, life span extension contributed most years. CONCLUSIONS: When the moving rectangle method is used to estimate the contributions of rectangularization and life span extension to the increase in life...

  8. 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

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

    Directory of Open Access Journals (Sweden)

    Sophie Wuerger

    Full Text Available 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.

  10. 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

  11. Small lymphocytes in peripheral lymphoid tissues of nude mice. Life-span and distribution

    DEFF Research Database (Denmark)

    Hougen, H P; Röpke, C

    1975-01-01

    The distribution of small lymphocytes according to life-span in the peripheral lymphoid tissues of the mouse mutant "nude" has been studied by means of auto-radiography and scintillation counting to evaluate the localization of B lymphocytes with varying life-span. The vast majority of the lympho......The distribution of small lymphocytes according to life-span in the peripheral lymphoid tissues of the mouse mutant "nude" has been studied by means of auto-radiography and scintillation counting to evaluate the localization of B lymphocytes with varying life-span. The vast majority...

  12. 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

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

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2016-02-01

    Full Text Available 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

  14. 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. PMID:21942279

  15. 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.

  16. Sequential and Coordinative Processing Dynamics in Figural Transformations across the Life Span.

    Science.gov (United States)

    Mayr, Ulrich; And Others

    1996-01-01

    Investigated the proposition that two distinct factors involved in life span cognitive development are mental speed and coordination efficiency. Results show dissociable speed of processing and working memory functioning over the life span and age-related differential effects of coordinative demands. (ET)

  17. 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…

  18. 7 CFR 701.37 - Loss of control of the property during the practice life span.

    Science.gov (United States)

    2010-01-01

    ... the property during the practice life span. In the event of voluntary or involuntary loss of control... 7 Agriculture 7 2010-01-01 2010-01-01 false Loss of control of the property during the practice life span. 701.37 Section 701.37 Agriculture Regulations of the Department of Agriculture...

  19. Optimisation by Selection and Compensation: Balancing Primary and Secondary Control in Life Span Development.

    Science.gov (United States)

    Heckhausen, Jutta; Schulz, Richard

    1993-01-01

    Discusses individuals as producers of their life span developments, and examines individuals' selection of their life paths and their proneness to failure. Considers a model that explains individuals' optimization of their life course management in terms of selection of life paths and compensation for age-related losses such that potential for…

  20. Reduced growth hormone signaling and methionine restriction: interventions that improve metabolic health and extend life span.

    Science.gov (United States)

    Brown-Borg, Holly M

    2016-01-01

    Interventions that improve health are often associated with longevity. Reduced growth hormone signaling has been shown to increase life span in mice by over 50%. Similarly, reductions in dietary intake of methionine, in rats and mice, result in life-span extension. Many factors affect metabolic health, mitochondrial function, and resistance to stressors, each of which influence aging and life span. This paper presents a comparison of these two interventions, as well as the results of a study combining these interventions, to understand potential mechanisms underlying their effectiveness in enhancing healthy aging.

  1. 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.

  2. LIFE SPAN OF A SMOOTH SOLUTION FOR THE SURFACE DIFFUSION FLOW

    Institute of Scientific and Technical Information of China (English)

    刘祖汉

    2003-01-01

    Consider the motion of immersed hypersurfaces driven by surface diffusion flow and give anlower bound on the life span of a smooth immersed solution, which depends only on how muchthe curvature of the initial surface is concentrated in space.

  3. Berberine Prolongs Life Span and Stimulates Locomotor Activity of Drosophila melanogaster

    OpenAIRE

    Navrotskaya, V. V.; Oxenkrug, G.; Vorobyova, L. I.; Summergrad, P.

    2012-01-01

    Drosophila melanogaster mutants with deficient kynurenine (KYN) formation from tryptophan (TRP) have longer life span than wild type flies. Administration of alpha-methyl-TRP and 5-methyl-TRY, the inhibitors of TRP-KYN metabolism, prolonged life span in wild-type flies. Both inhibitors are not available for human use. Berberine, an isoquinoline alkaloid isolated from Berberis aristata, is known as the herb widely used in traditional Chinese and Indian medicine. Berberin is a strong inhibitor ...

  4. Comparative transcriptional profiling identifies takeout as a gene that regulates life span

    OpenAIRE

    Bauer, Johannes; Antosh, Michael; Chang, Chengyi; Schorl, Christoph; Kolli, Santharam; Neretti, Nicola; HELFAND, STEPHEN L.

    2010-01-01

    A major challenge in translating the positive effects of dietary restriction (DR) for the improvement of human health is the development of therapeutic mimics. One approach to finding DR mimics is based upon identification of the proximal effectors of DR life span extension. Whole genome profiling of DR in Drosophila shows a large number of changes in gene expression, making it difficult to establish which changes are involved in life span determination as opposed to other unrelated physiolog...

  5. An Eco-Cultural and Interpersonal Relations Approach to Development Over the Life Span

    OpenAIRE

    Trommsdorff, Gisela

    2002-01-01

    This chapter aims to illustrate the role of culture for development over the life-span. First, theoretical approaches on development in culture are presented, starting from early anthropological to recent eco-cultural approaches. Then culture-specific conceptualisations of development over the life span are discussed, including childhood, adolescence, adulthood, and old age. Finally, recent studies on subjective theories, transmissions of values, and intergenerational relations are discussed ...

  6. 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.

  7. Copper supplementation increases yeast life span under conditions requiring respiratory metabolism

    OpenAIRE

    Kirchman, Paul A.; Botta, Gabriela

    2006-01-01

    To further exploit yeast as a model for cellular aging we have modified the replicative life span assay to force respiration, by replacing glucose with the non-fermentable carbon source glycerol. The growth rates of several different strains varied greatly, with doubling times ranging from 2.7 to 7 hours. Life spans of all strains were lower on media containing glycerol than on media containing glucose. However, supplementation of glycerol-containing media with copper resulted in increases in...

  8. 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

  9. '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.

  10. 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.

  11. 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.

  12. How to prolong network life-span in wireless networks

    CERN Document Server

    Anderson, Dana

    2011-01-01

    One of the most important problems in wireless sensor network is to develop a routing protocol that has energy efficiency. Since the power of the sensor Nodes are limited, conserving energy and network life is a critical issue in wireless sensor network. Clustering is one of the known methods widely used to face these challenges. In this paper, a cluster based communication protocol with considering the low energy consumption in wireless sensor networks, is introduced which balances the energy load among sensor nodes. The nodes close to each other have more overlap; they sense the same data from environment and cause a waste of energy by generating repetitive data. In this paper, a cluster based routing protocol is introduced, in the proposed protocol, in each round a certain number of nodes are specified; the nodes which have at least one neighboring node at a distance less than the threshold. Then, among them the nodes with less energy and greater overlap with their neighbors have been chosen to go to sleep...

  13. From yeast to human: exploring the comparative biology of methionine restriction in extending eukaryotic life span.

    Science.gov (United States)

    McIsaac, R Scott; Lewis, Kaitlyn N; Gibney, Patrick A; Buffenstein, Rochelle

    2016-01-01

    Methionine restriction is a widely reported intervention for increasing life span in several model organisms. Low circulating levels of methionine are evident in the long-lived naked mole-rat, suggesting that it naturally presents with a life-extending phenotype akin to that observed in methionine-restricted animals. Similarly, long-lived dwarf mice also appear to have altered methionine metabolism. The mechanisms underlying methionine-restriction effects on life-span extension, however, remain unknown, as do their potential connections with caloric restriction, another well-established intervention for prolonging life span. Paradoxically, methionine is enriched in proteins expressed in mitochondria and may itself serve an important role in the detoxification of reactive oxygen species and may thereby contribute to delayed aging. Collectively, we highlight the evidence that modulation of the methionine metabolic network can extend life span-from yeast to humans-and explore the evidence that sulfur amino acids and the concomitant transsulfuration pathway play a privileged role in this regard. However, systematic studies in single organisms (particularly those that exhibit extreme longevity) are still required to distinguish the fundamental principles concerning the role of methionine and other amino acids in regulating life span.

  14. The Writing Process: Effects of Life-Span Development on Imaging.

    Science.gov (United States)

    Shock, Diane Hahn

    A qualitative study focused on incubation and illumination within the act of writing to determine if life-span development affects image production during these creative, cognitive acts. Sixteen subjects of both sexes from four age groups represented major developmental stages in the life cycle. The research design provided two 90-minute sessions…

  15. Chronological Changes of Quality of Life in Long-Term Survivors after Gastrectomy for Gastric Cancer

    Science.gov (United States)

    Yu, Wansik; Park, Ki Bum; Chung, Ho Young; Kwon, Oh Kyoung; Lee, Seung Soo

    2016-01-01

    Purpose A few studies have prospectively evaluated changes in quality of life (QoL) after surgery in short-term survivors; however, no prospective study has evaluated the longitudinal changes in QoL in long-terms survivors. We prospectively evaluated the chronological changes in QoL after a gastrectomy over a 5-year postoperative period in a large group of patients. Materials and Methods QoL data from the European Organization for Research and Treatment of Cancer QLQ-C30 and the QLQ-STO22 questionnaires were obtained from 254 patients who completed the entire series of QoL assessments preoperatively and at 1, 2, 3, 4, and 5 years after surgery. Results There was no statistically significant change in global health status/QoL during the 5-year postoperative period. Decreases in QoL from upper gastrointestinal symptoms including diarrhea (p physical functioning (p physical functioning, role functioning, and body image. In addition, patients should be encouraged to preserve self-esteem and maintain social activity. PMID:27004956

  16. ω-6 Polyunsaturated fatty acids extend life span through the activation of autophagy.

    Science.gov (United States)

    O'Rourke, Eyleen J; Kuballa, Petric; Xavier, Ramnik; Ruvkun, Gary

    2013-02-15

    Adaptation to nutrient scarcity depends on the activation of metabolic programs to efficiently use internal reserves of energy. Activation of these programs in abundant food regimens can extend life span. However, the common molecular and metabolic changes that promote adaptation to nutritional stress and extend life span are mostly unknown. Here we present a response to fasting, enrichment of ω-6 polyunsaturated fatty acids (PUFAs), which promotes starvation resistance and extends Caenorhabditis elegans life span. Upon fasting, C. elegans induces the expression of a lipase, which in turn leads to an enrichment of ω-6 PUFAs. Supplementing C. elegans culture media with these ω-6 PUFAs increases their resistance to starvation and extends their life span in conditions of food abundance. Supplementation of C. elegans or human epithelial cells with these ω-6 PUFAs activates autophagy, a cell recycling mechanism that promotes starvation survival and slows aging. Inactivation of C. elegans autophagy components reverses the increase in life span conferred by supplementing the C. elegans diet with these fasting-enriched ω-6 PUFAs. We propose that the salubrious effects of dietary supplementation with ω-3/6 PUFAs (fish oils) that have emerged from epidemiological studies in humans may be due to a similar activation of autophagic programs. PMID:23392608

  17. 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

  18. 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.

  19. Effect of carbon ions on life span shortening and tumorigenesis in mice.

    Science.gov (United States)

    Kakinuma, Shizuko; Kubo, Ayumi; Amasaki, Yoshiko; Nohima, Kumie; Imaoka, Tatsuhiko; Nishimura, Mayumi; Shimada, Yoshiya

    2004-11-01

    One of the important concerns for astronauts in space is cancer risk associated with cosmic radiation, including heavy particle ions. But little information on cancer risk is available. We investigated the effect of carbon ions on life span shortening and tumor induction in B6C3F1 mice. The mice were exposed weekly to 0.4 and 2.0 Gy whole-body carbon-ion- or X-ray-irradiation for 4 consecutive weeks. The spectrum of induced tumors varied depending on the dose. The cause of death was thymic lymphomas and liver tumors at high and low dose, respectively. The life span shortening by X-rays was proportional to dose, while carbon ions produced a convex upward relationship. The relative biological effectiveness for the 50% life span shortening was about 1.4. The large effect of carbon ions encourages the study on tumor induction at low doses in the space. PMID:15900637

  20. Explanatory style across the life span: evidence for stability over 52 years.

    Science.gov (United States)

    Burns, M O; Seligman, M E

    1989-03-01

    Analyzed explanatory style across the life span. 30 Ss whose average age was 72 responded to questions about their current life and provided diaries or letters written in their youth, an average of 52 years earlier. A blind content analysis of explanatory style derived from these 2 sources revealed that explanatory style for negative events was stable throughout adult life (r = .54, p less than .002). In contrast, there appeared to be no stability of explanatory style for positive events between the same 2 time periods. These results suggest that explanatory style for negative events may persist across the life span and may constitute an enduring risk factor for depression, low achievement, and physical illness. PMID:2926642

  1. 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

  2. Age, growth and size interact with stress to determine life span and mortality.

    Science.gov (United States)

    Roach, Deborah Ann

    2012-10-01

    Individuals in a large experimental field population, of the short-lived perennial species Plantago lanceolata, were followed to determine the sources of variation that influence mortality and life span. The design included multiple age groups with initially similar genetic structure, which made it possible to separate age effects from period effects and to identify the genetic component to variation in life span. During a period of stress, individuals of all ages showed parallel increases in mortality but different cohorts experienced this period of high mortality at different ages. This then influenced the distribution of life spans across cohorts. Age and size-age interactions influenced mortality during the period of stress. Smaller individuals died but only if they were old. Additionally, growth and age interacted with stress such that older individuals had negative growth and high mortality whereas younger individuals had positive growth and relatively lower mortality during stress. The results of this study show that it is not simply the environment that can have a major impact on demography in natural populations; rather, age, size and growth can interact with the environment to influence mortality and life span when the environment is stressful. PMID:22664575

  3. FLEXIBLE PAVEMENT REHABILITATION DESIGN BASED ON PAVEMENT SERVICE LIFE TIME SPAN LEFT

    OpenAIRE

    Gamelyak, I.; Shevchuk, V.

    2005-01-01

    The design of flexible pavement rehabilitation is analysed in terms of durability-cost. A notion of the remaining service life span is described. the model of rehabilitation strategy selection is presented for both design project and operation stages. the results can be used in the pavement management system.

  4. Gains and Losses in Creative Personality as Perceived by Adults across the Life Span

    Science.gov (United States)

    Hui, Anna N. N.; Yeung, Dannii Y.; Sue-Chan, Christina; Chan, Kara; Hui, Desmond C. K.; Cheng, Sheung-Tak

    2014-01-01

    In this study, we used a life span model to study the subjective perception of creative personality (CP) in emerging, young, middle-aged, and older Hong Kong Chinese adults. We also asked participants to estimate the approximate age by which people develop and lose CP across adulthood. We expected an interesting interplay between internalized age…

  5. 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…

  6. Life-Span Development of Visual Working Memory: When Is Feature Binding Difficult?

    Science.gov (United States)

    Cowan, Nelson; Naveh-Benjamin, Moshe; Kilb, Angela; Saults, J. Scott

    2006-01-01

    We asked whether the ability to keep in working memory the binding between a visual object and its spatial location changes with development across the life span more than memory for item information. Paired arrays of colored squares were identical or differed in the color of one square, and in the latter case, the changed color was unique on…

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. Like cognitive function, decision making across the life span shows profound age-related changes

    OpenAIRE

    Tymula, Agnieszka; Rosenberg Belmaker, Lior A.; Ruderman, Lital; Paul W Glimcher; Levy, Ifat

    2013-01-01

    Although largely unstudied, behavioral changes in decision making across the life span have implications for problems associated with poor decision making at different life stages, such as careless driving in adolescents and disadvantageous medical or financial decision making in older adults. We examine age-based differences in individual decision-making characteristics—choice consistency, rationality, and preferences for known and unknown risks—in 12- to 90-y-olds. We found that even the he...

  12. 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.

  13. Rapid growth and short life spans characterize pipefish populations in vulnerable seagrass beds.

    Science.gov (United States)

    Parkinson, K L; Booth, D J

    2016-05-01

    The life-history traits of two species of pipefish (Syngnathidae) from seagrass meadows in New South Wales, Australia, were examined to understand whether they enhance resilience to habitat degradation. The spotted pipefish Stigmatopora argus and wide-bodied pipefish Stigmatopora nigra exhibit some of the shortest life spans known for vertebrates (longevity up to 150 days) and rapid maturity (male S. argus 35 days after hatching (DAH) and male S. nigra at 16-19 DAH), key characteristics of opportunistic species. Growth rates of both species were extremely rapid (up to 2 mm day(-1) ), with seasonal and sex differences in growth rate. It is argued that short life spans and high growth rates may be advantageous for these species, which inhabit one of the most threatened marine ecosystems on earth. PMID:27005315

  14. 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

  15. 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

  16. 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.

  17. LIFE-SPAN OF CLASSICAL SOLUTIONS TO QUASILINEAR HYPERBOLIC SYSTEMS WITH SLOW DECAY INITIAL DATA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The author considers the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with "slow” decay initial data. By constructing an example, first it is illustrated that the classical solution to this kind of Cauchy problem may blow up in a finite time, even if the system is weakly linearly degenerate. Then some lower bounds of the life-span of classical solutions are given in the case that the system is weakly linearly degenerate. These estimates imply that, when the system is weakly linearly degenerate, the classical solution exists almost globally in time. Finally, it is proved that Theorems 1.1-1.3 in [2] are still valid for this kind of initial data.

  18. 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. PMID:27127236

  19. 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. PMID:23528790

  20. The Mother Enrichment Program: A Genetic System for Facile Replicative Life Span Analysis in Saccharomyces cerevisiae

    OpenAIRE

    Lindstrom, Derek L.; Gottschling, Daniel E.

    2009-01-01

    The replicative life span (RLS) of Saccharomyces cerevisiae has been established as a model for the genetic regulation of longevity despite the inherent difficulty of the RLS assay, which requires separation of mother and daughter cells by micromanipulation after every division. Here we present the mother enrichment program (MEP), an inducible genetic system in which mother cells maintain a normal RLS—a median of 36 generations in the diploid MEP strain—while the proliferative potential of da...

  1. Plasticity of Executive Control Induced by Process-Based Cognitive Training Across the Life-Span

    OpenAIRE

    Zinke, Katharina

    2012-01-01

    Plasticity is a central concept within the life-span approach of development and is defined as the ability of an individual to change and reorganize in response to environmental challenges (e.g., Baltes & Singer, 20019. Such intraindividual changes can be induced by systematic cognitive training. Recent studies suggest that substantial amounts of plasticity can be induced in executive control functions with a process-based training approach. These newer studies show that repeated practice on ...

  2. Everyday problem solving across the adult life span: solution diversity and efficacy

    OpenAIRE

    Mienaltowski, Andrew

    2011-01-01

    Everyday problem solving involves examining the solutions that individuals generate when faced with problems that take place in their everyday experiences. Problems can range from medication adherence and meal preparation to disagreeing with a physician over a recommended medical procedure or compromising with extended family members over where to host Thanksgiving dinner. Across the life span, research has demonstrated divergent patterns of change in performance based on the type of everyday...

  3. Diabetes mellitus as a cause of life span shortening in locally exposed rats

    International Nuclear Information System (INIS)

    A study was made of the development of remote radiation pathology of pancreas in male rats after local irradiation of abdomen with doses of 5, 10 (two fractions of 5 Gy at a 30-day interval) and 15 Gy (three fractions of 5 Gy at a 30-day interval). The clinical and morphological estimates show the dose-dependent development of diabetes mellitus and 1.8-fold shortening of the life span, as compared to biological control

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

    OpenAIRE

    Olson, S. Jay

    2015-01-01

    If advanced civilizations appear in the universe with an ability and desire to expand, the entire universe can become saturated with life on a short timescale, even if such expanders appear rarely. Our presence in an apparently 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 ap...

  5. 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.

  6. Adaptive Physiological Response to Perceived Scarcity as a Mechanism of Sensory Modulation of Life Span.

    Science.gov (United States)

    Waterson, Michael J; Chan, Tammy P; Pletcher, Scott D

    2015-09-01

    Chemosensation is a potent modulator of organismal physiology and longevity. In Drosophila, loss of recognition of diverse tastants has significant and bidirectional life-span effects. Recently published results revealed that when flies were unable to taste water, they increased its internal generation, which may have subsequently altered life span. To determine whether similar adaptive responses occur in other contexts, we explored the impact of sensory deficiency of other metabolically important molecules. Trehalose is a major circulating carbohydrate in the fly that is recognized by the gustatory receptor Gr5a. Gr5a mutant flies are short lived, and we found that they specifically increased whole-body and circulating levels of trehalose, but not other carbohydrates, likely through upregulation of de novo synthesis. dILP2 transcript levels were increased in Gr5a mutants, a possible response intended to reduce hypertrehalosemia, and likely a contributing factor to their reduced life span. Together, these data suggest that compensatory physiological responses to perceived environmental scarcity, which are designed to alleviate the ostensive shortage, may be a common outcome of sensory manipulation. We suggest that future investigations into the mechanisms underlying sensory modulation of aging may benefit by focusing on direct or indirect consequences of physiological changes that are designed to correct perceived disparity with the environment. PMID:25878032

  7. 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.).

  8. 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…

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

    International Nuclear Information System (INIS)

    This study was designed to measure the life shortening of C57BL/6J male mice as a result of exposure to five external doses from 60Co 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

  10. Shorter Life Span of Microorganisms and Plants as a Consequence of Shielded Magnetic Environment

    Science.gov (United States)

    Dobrota, C.; Piso, I. M.; Bathory, D.

    The geomagnetic field is an essential environmental factor for life and health on this planet. In order to survey how magnetic fields affect the life span and the nitrogenase (an iron-sulphur enzyme) activity of Azotobacter chroococcum as well as the life span, the main organic synthesis and the water balance of plants (22 species), the biological tests were incubated under shielded magnetic field and also in normal geo-magnetic environment. The shielding level was about 10-6 of the terrestrial magnetic field.Life cycles of all organisms require the co-ordinated control of a complex set of interlocked physiological processes and metabolic pathways. Such processes are likely to be regulated by a large number of genes. Our researches suggest that the main point in biological structures, which seems to be affected by the low magnetic environment, is the water molecule. Magnetic field induces a molecular alignment. Under shielded conditions, unstructured water molecules with fewer hydrogen bonds, which are producing a more reactive environment, are occurring. As compared to control, the life span of both microorganisms and plants was shorter in shielded environment. A higher nitrogenase affinity for the substrate was recorded in normal geo-magnetic field compared to low magnetic field. The synthesis of carbohydrates, lipids, proteins and enzymes was modified under experimental conditions. The stomatal conductance was higher between 158 and 300% in shielded environment indicating an important water loss from the plant cells.Our results support the idea that the shielded magnetic environment induces different reactions depending on the time of exposure and on the main metabolic pathways of the cells.

  11. 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.

  12. 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. PMID:19485668

  13. 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

    expectancy due to natural causes (physical illnesses) and unnatural causes (suicide and accidents) in relation to age. RESULTS: A total of 22,635 patients with bipolar disorder were included in the study in addition to data from the entire Danish general population of 5.4 million people. At age 15 years......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......, 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...

  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. 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

    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.

  16. [Effect of epitalon and melatonin on life span and spontaneous carcinogenesis in senescence accelerated mice (SAM)].

    Science.gov (United States)

    Anisimov, V N; Popovich, I G; Zabezhinskiĭ, M A; Rozenfel'd, S V; Khavinson, V Kh; Semenchenko, A V; Iashin, A I

    2005-01-01

    Female senescence accelerated mice SAMP-1. (prone) and SAMR-1 (resistant) were exposed 5 times a week monthly to melatonin (with drinking water 20mg/ml during the night hours) or to s.c. injections of epitalon (Ala-Glu-Asp-Gly) at a single dose 1mkg/mouse. Control mice were intact or exposed to injection of 0.1 ml normal saline. The body weight and temperature, food consumption, estrous function were monitored regularly. The life span and tumor incidence were evaluated as well. As age advanced, the weight increased whereas food consumption and body temperature did not change. There was no significant substrain difference in these parameters. Exposure to melatonin or epitalon also failed to influence those indices. As age advanced, the incidence of irregular estrous cycles increased both in SAMP-1 and SAMR-1, whereas the treatment with both melatonin and epitalon prevented such disturbances. SAMP-1 revealed some features of accelerated aging as compared to SAMR-1. The mean life span of the 10% of the last survivors among treated SAMP-1 was shorter than that of SAMR-1, aging rate increased and mortality doubling time decreased. There was a direct correlation between body mass of the two substrains at the age of 3 and 12 months matched by body mass increase and longer life span. Melatonin or epitalon treatment was followed by longer mean and maximum survival in the 10% of the last survivors among SAMP-1. Melatonin involved decreased aging rate and increased mortality doubling time. Malignant lymphomas predominated in SAM without any significant difference in frequency between the substrains. While melatonin failed to influence tumor incidence or term of detection in SAMP-1, neither did epitalon affect frequency. However, it was followed by longer survival in tumor-free animals. No link between melatonin or epitalon treatment, on the one hand, and carcinogenesis, on the other, was reported in SAMR-1. PMID:15909815

  17. Stability and change in risk-taking propensity across the adult life span.

    Science.gov (United States)

    Josef, Anika K; Richter, David; Samanez-Larkin, Gregory R; Wagner, Gert G; Hertwig, Ralph; Mata, Rui

    2016-09-01

    Can risk-taking propensity be thought of as a trait that captures individual differences across domains, measures, and time? Studying stability in risk-taking propensities across the life span can help to answer such questions by uncovering parallel, or divergent, trajectories across domains and measures. We contribute to this effort by using data from respondents aged 18 to 85 in the German Socio-Economic Panel Study (SOEP) and by examining (a) differential stability, (b) mean-level differences, and (c) individual-level changes in self-reported general (N = 44,076) and domain-specific (N = 11,903) risk-taking propensities across adulthood. In addition, we investigate (d) the correspondence between cross-sectional trajectories of self-report and behavioral measures of social (trust game; N = 646) and nonsocial (monetary gamble; N = 433) risk taking. The results suggest that risk-taking propensity can be understood as a trait with moderate stability. Results show reliable mean-level differences across the life span, with risk-taking propensities typically decreasing with age, although significant variation emerges across domains and individuals. Interestingly, the mean-level trajectory for behavioral measures of social and nonsocial risk taking was similar to those obtained from self-reported risk, despite small correlations between task behavior and self-reports. Individual-level analyses suggest a link between changes in risk-taking propensities both across domains and in relation to changes in some of the Big Five personality traits. Overall, these results raise important questions concerning the role of common processes or events that shape the life span development of risk-taking across domains as well as other major personality facets. (PsycINFO Database Record PMID:26820061

  18. SECONDARY CRITICAL EXPONENT AND LIFE SPAN FOR A DOUBLY SINGULAR PARABOLIC EQUATION WITH A WEIGHTED SOURCE

    Institute of Scientific and Technical Information of China (English)

    Pan ZHENG; Chunlai MU; Xuegang HU; Fuchen ZHANG

    2016-01-01

    This paper deals with the Cauchy problem for a doubly singular parabolic equa-tion with a weighted source ut=div(|?u|p?2?um)+|x|αuq, (x, t)∈RN × (0, T ), where N ≥ 1, 1 max{0, 3?p? pN} satisfying 2 1, andα > N (3?p?m)?p. We give the secondary critical exponent on the decay asymptotic behavior of an initial value at infinity for the existence and non-existence of global solutions of the Cauchy problem. Moreover, the life span of solutions is also studied.

  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. 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.

  1. Super's Life-Span, Life-Space Approach and Its Outlook for Refinement.

    Science.gov (United States)

    Herr, Edwin L.

    1997-01-01

    Describes the major elements of a lifespan, life-space approach to career development. Looks at the origins of these elements and briefly describes their evolution. Suggests five categories of possible future refinements in this approach so as to enhance theory building, testing, and synthesizing this model's applicability. (RJM)

  2. 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

  3. 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 PMID:27560768

  4. 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

  5. DOE life-span radiation effects studies at Pacific Northwest Laboratory

    International Nuclear Information System (INIS)

    Major life-span radiation effects studies at Pacific Northwest Laboratory fall into three categories: (1) studies with beagle dogs exposed to plutonium compounds via a single inhalation; (2) studies with dogs and rats exposed chronically via inhalation to various combinations and concentrations of radon, radon daughters, and other components of uranium mine atmospheres; and (3) a study in which rats are exposed via single inhalation, in very large numbers, to very low concentrations of 239PuO2. Exposure of beagles currently on study was initiated in 1970 with 239PuO2, in 1973 with 238PuO2, and in 1976 with 239Pu(NO3)4. These experiments involve more than 500 animals, many of them still alive. Experiments seeking to explain the increased incidence of lung cancer in uranium miners have been in progress since 1966. Present emphasis is on studies with rats, in an attempt to define dose-effect relationships at the lowest feasible radon-daughter exposure levels. Our very-low-level experiment with inhaled 239PuO2 in rats, with exposures still under way, includes 1000 rats in the control group and 1000 rats in the lowest-exposure group, where life-span lung doses of <5 rads are anticipated

  6. Analysis of neoplasia in life-span radiation effects studies in animals

    International Nuclear Information System (INIS)

    Analysis of the occurrence of neoplastic disease in animals on life-span radiation effects experiments presents some unique problems. A simple analysis of tumor incidence or prevalence may overlook differences in the nature of specific types of neoplasms which can be extremely important in interpreting the results. Analyses should address not only whether or not an animal has a particular tumor type, but should also address the ultimate effect of that tumor on the fate of the animal. For life-span studies in dogs, where multiple neoplasms in individual animals are the rule rather than the exception this is particularly important. An easily computerized approach to performing such analyses has been adapted from a previous work. Neoplasms are classified as incidental (those found at necropsy in dogs which died of an unrelated cause), mortality-independent (those seen in live dogs and diagnosed after surgical removal), or fatal (those directly or indirectly responsible for death). In the authors' studies such categorization has allowed the evaluation of the overall impact of a tumor on an animal and enhanced the understanding of the meaning of experimental results. Adoption of a similar approach by various groups performing radiation effects studies in animals would facilitate the comparative evaluation of data from these studies

  7. CALHM1 Deletion in Mice Affects Glossopharyngeal Taste Responses, Food Intake, Body Weight, and Life Span.

    Science.gov (United States)

    Hellekant, Göran; Schmolling, Jared; Marambaud, Philippe; Rose-Hellekant, Teresa A

    2015-07-01

    Stimulation of Type II taste receptor cells (TRCs) with T1R taste receptors causes sweet or umami taste, whereas T2Rs elicit bitter taste. Type II TRCs contain the calcium channel, calcium homeostasis modulator protein 1 (CALHM1), which releases adenosine triphosphate (ATP) transmitter to taste fibers. We have previously demonstrated with chorda tympani nerve recordings and two-bottle preference (TBP) tests that mice with genetically deleted Calhm1 (knockout [KO]) have severely impaired perception of sweet, bitter, and umami compounds, whereas their sour and salty tasting ability is unaltered. Here, we present data from KO mice of effects on glossopharyngeal (NG) nerve responses, TBP, food intake, body weight, and life span. KO mice have no NG response to sweet and a suppressed response to bitter compared with control (wild-type [WT]) mice. KO mice showed some NG response to umami, suggesting that umami taste involves both CALHM1- and non-CALHM1-modulated signals. NG responses to sour and salty were not significantly different between KO and WT mice. Behavioral data conformed in general with the NG data. Adult KO mice consumed less food, weighed significantly less, and lived almost a year longer than WT mice. Taken together, these data demonstrate that sweet taste majorly influences food intake, body weight, and life span. PMID:25855639

  8. The Altered Responses of a New Mutant long life span 1 to Cytokinin in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Xinghua Shao; Ru Yang; Jingyu Wang; Qi Fang; Bin Yao; Yang Wang; Yue Sun; Xiaofang Li

    2012-01-01

    Cytokinins are a class of essential plant hormones regulating plant growth and development.Although the two-component phosphorelay pathway of cytokinin has been well characterized,the intact cytokinin responses regulation picture still needs to be fully depicted.Here we report a new mutant,long life span Ⅰ(lls1),which displays dwarf stature,curled leaves,numerous axillary branches and nearly 5-month life span.Exogenous cytokinin could not recover the phenotypes of the mutant.Moreover,mutation in lls1 suppressed the cytokinin-responsive phenotypes,including root and hypocotyl growth inhibition,anthocyanin accumulation,metaxylemn promotion in primary root development.The induction of cytokinin-responsive genes,ARR5,AHP5,and CKX3,was also suppressed in lls1.According to quantitative RT-PCR (qRT-PCR) and microarray results,the basal expression of positive factors AHP5,ARR1,and ARR10 were down-regulated,while the negative factors ARR4 and ARR5 were up-regulated.Our results suggested that LLS1 gene might be involved in the regulation of cytokinin signaling,It was mapped to chromosome 4 where no other eytokinin relevant gene has been reported.

  9. CTT1 overexpression increases life span of calorie-restricted Saccharomyces cerevisiae deficient in Sod1.

    Science.gov (United States)

    Rona, Germana; Herdeiro, Ricardo; Mathias, Cristiane Juliano; Torres, Fernando Araripe; Pereira, Marcos Dias; Eleutherio, Elis

    2015-06-01

    Studies using different organisms revealed that reducing calorie intake, without malnutrition, known as calorie restriction (CR), increases life span, but its mechanism is still unkown. Using the yeast Saccharomyces cerevisiae as eukaryotic model, we observed that Cu, Zn-superoxide dismutase (Sod1p) is required to increase longevity, as well as to confer protection against lipid and protein oxidation under CR. Old cells of sod1 strain also presented a premature induction of apoptosis. However, when CTT1 (which codes for cytosolic catalase) was overexpressed, sod1 and WT strains showed similar survival rates. Furthermore, CTT1 overexpression decreased lipid peroxidation and delayed the induction of apoptotic process. Superoxide is rapidly converted to hydrogen peroxide by superoxide dismutase, but it also undergoes spontaneous dismutation albeit at a slower rate. However, the quantity of peroxide produced from superoxide in this way is two-fold higher. Peroxide degradation, catalyzed by catalase, is of vital importance, because in the presence of a reducer transition metal peroxide is reduced to the highly reactive hydroxyl radical, which reacts indiscriminately with most cellular constituents. These findings might explain why overexpression of catalase was able to overcome the deficiency of Sod1p, increasing life span in response to CR. PMID:25573485

  10. Neoplastic and life-span effects of chronic exposure to tritium. II. Rats exposed in utero

    International Nuclear Information System (INIS)

    A study was conducted to determine the effects on neoplasia incidence and life-span of exposure in utero to a major environmental radionuclide. Sprague-Dawley rats were continuously exposed to tritiated water (HTO) from conception through birth in doses of 0, 1, 10, 50, and 100 μCi HTO/ml body water. HTO administration was terminated at birth. Calculated cumulative doses during gestation were approximately 0, 6.6, 66, 330, and 660 rads of total body irradiation. Under these exposure conditions, the two highest doses resulted in sterile offspring. Animals surviving through 30 days postnatally were defined as the study population and observed until their deaths. Intrauterine exposures to doses up to 66 rads had no significant effects on either sex with respect to lifespan, overall neoplasia incidence, incidence rate, or onset of mammary fibroadenomas. Females exposed to 330 or 660 rads were sterile and had lower incidence rates of mammary fibroadenomas than did controls; at 660 rads females had a lower incidence of overall neoplasia and reduced mean lifespans. Sterile male offspring had reduced mean longevity after irradiation at 660 rads. Regardless of dose group, females had significantly higher incidences of neoplasia and longer life-spans than males

  11. Comparative transcriptional pathway bioinformatic analysis of dietary restriction, Sir2, p53 and resveratrol life span extension in Drosophila

    OpenAIRE

    Antosh, Michael; Whitaker, Rachel; Kroll, Adam; Hosier, Suzanne; Chang, Chengyi; Bauer, Johannes; Cooper, Leon; Neretti, Nicola; HELFAND, STEPHEN L.

    2011-01-01

    A multiple comparison approach using whole genome transcriptional arrays was used to identify genes and pathways involved in calorie restriction/dietary restriction (DR) life span extension in Drosophila. Starting with a gene centric analysis comparing the changes in common between DR and two DR related molecular genetic life span extending manipulations, Sir2 and p53, lead to a molecular confirmation of Sir2 and p53's similarity with DR and the identification of a small set of commonly regul...

  12. [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.

  13. Metabotypes with properly functioning mitochondria and anti-inflammation predict extended productive life span in dairy cows.

    Science.gov (United States)

    Huber, K; Dänicke, S; Rehage, J; Sauerwein, H; Otto, W; Rolle-Kampczyk, U; von Bergen, M

    2016-01-01

    The failure to adapt metabolism to the homeorhetic demands of lactation is considered as a main factor in reducing the productive life span of dairy cows. The so far defined markers of production performance and metabolic health in dairy cows do not predict the length of productive life span satisfyingly. This study aimed to identify novel pathways and biomarkers related to productive life in dairy cows by means of (targeted) metabolomics. In a longitudinal study from 42 days before up to 100 days after parturition, we identified metabolites such as long-chain acylcarnitines and biogenic amines associated with extended productive life spans. These metabolites are mainly secreted by the liver and depend on the functionality of hepatic mitochondria. The concentrations of biogenic amines and some acylcarnitines differed already before the onset of lactation thus indicating their predictive potential for continuation or early ending of productive life. PMID:27089826

  14. Potentially Traumatic Events at Different Points in the Life Span and Mental Health: Findings From SHARE-Israel

    OpenAIRE

    Shrira, Amit; Shmotkin, Dov; Litwin, Howard

    2012-01-01

    This study addressed the association between adversity cumulated at different points in the life span and present mental health. Data of 1,130 participants aged 50+ were drawn from the Israeli component of the Survey of Health, Ageing and Retirement in Europe (SHARE). Measures included an inventory of potentially traumatic events, mental distress (depressive symptoms), and well-being (quality of life, life satisfaction). Adversity reported to have occurred early in life was positively related...

  15. 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. PMID:23988583

  16. 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.

  17. Neuromodulation of associative and organizational plasticity across the life span: empirical evidence and neurocomputational modeling.

    Science.gov (United States)

    Li, Shu-Chen; Brehmer, Yvonne; Shing, Yee Lee; Werkle-Bergner, Markus; Lindenberger, Ulman

    2006-01-01

    Developmental plasticity is the key mechanism that allows humans and other organisms to modify and adapt to contextual and experiential influences. Thus, reciprocal co-constructive interactions between behavioral and neuronal plasticity play important roles in regulating neurobehavioral development across the life span. This review focuses on behavioral and neuronal evidence of lifespan differences in associative memory plasticity and plasticity of the functional organization of cognitive and cortical processes, as well as the role of the dopaminergic system in modulating such plasticity. Special attention is given to neurocomputational models that help exploring lifespan differences in neuromodulation of neuronal and behavioral plasticity. Simulation results from these models suggest that lifespan changes in the efficacy of neuromodulatory mechanisms may shape associative memory plasticity and the functional organization of neurocognitive processes by affecting the fidelity of neuronal signal transmission, which has consequences for the distinctiveness of neurocognitive representations and the efficacy of distributed neural coding. PMID:16930705

  18. 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. PMID:23429724

  19. 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.

  20. Life spans of a Bellman-Harris branching process with immigration

    International Nuclear Information System (INIS)

    One considers two schemes of the Bellman-Harris process with immigration when a) the lifetime of the particles is an integral-valued random variable and the immigration is defined by a sequence of independent random variables; b) the distribution of the lifetime of the particles is nonlattice and the immigration is a process with continuous time. One investigates the properties of the life spans of such processes. The results obtained here are a generalization to the case of Bellman-Harris processes of the results of A.M. Zubkov, obtained for Markov branching processes. For the proof one makes use in an essential manner of the known inequalities of Goldstein, estimating the generating function of the Bellman-Harris process in terms of the generating functions of the imbedded Galton-Watson process

  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. Stability and change: Stress responses and the shaping of behavioral phenotypes over the life span.

    Science.gov (United States)

    Hennessy, Michael B; Kaiser, Sylvia; Tiedtke, Tobias; Sachser, Norbert

    2015-01-01

    In mammals, maternal signals conveyed via influences on hypothalamic-pituitary-adrenal (HPA) activity may shape behavior of the young to be better adapted for prevailing environmental conditions. However, the mother's influence extends beyond classic stress response systems. In guinea pigs, several hours (h) of separation from the mother activates not only the HPA axis, but also the innate immune system, which effects immediate behavioral change, as well as modifies behavioral responsiveness in the future. Moreover, the presence of the mother potently suppresses the behavioral consequences of this innate immune activation. These findings raise the possibility that long-term adaptive behavioral change can be mediated by the mother's influence on immune-related activity of her pups. Furthermore, the impact of social partners on physiological stress responses and their behavioral outcomes are not limited to the infantile period. A particularly crucial period for social development in male guinea pigs is that surrounding the attainment of sexual maturation. At this time, social interactions with adults can dramatically affect circulating cortisol concentrations and social behavior in ways that appear to prepare the male to best cope in its likely future social environment. Despite such multiple social influences on the behavior of guinea pigs at different ages, inter-individual differences in the magnitude of the cortisol response remain surprisingly stable over most of the life span. Together, it appears that throughout the life span, physiological stress responses may be regulated by social stimuli. These influences are hypothesized to adjust behavior for predicted environmental conditions. In addition, stable individual differences might provide a means of facilitating adaptation to less predictable conditions. PMID:26816517

  3. Life-span studies on mice exposed to heavy charged particles or photons

    International Nuclear Information System (INIS)

    The carcinogenic risk associated with heavy charged (HZE) particles is currently undefined. Precise relationships have been established for relative biological effectiveness (RBE) and linear energy transfer (LET) for the killing of cells in vitro and for other short-term (acute) biological responses to charged particles, but comparable information is lacking on carcinogenic response. Experiments are in progress to study induction/promotion of Harderian gland tumors, and the present life-span studies should provide complementary information because it is inferred that over the dose range explored in the present experiments, most of the life shortening is attributable to induction/promotion of neoplastic diseases. The information sought is important both for understanding fundamental mechanisms of radiation carcinogenesis and for assessing the risk of the space radiation environment and of radiation therapy or other medical applications of heavy charged particles in young patients whose life expectancy could permit expression of a tumor. The hypothesis tested in the core experiment, designated SKYHOOK, is that LET dependence for life shortening and excess mortality rates observed after mice are exposed to heavy charged particles (HZE) will conform to existing theory and observations based on other endpoints; namely, a peak RBE at a dose-averaged LET value of approximately 100 keV/μm, with RBE diminishing at lesser and greater values of LET. Because results on cell killing show different RBE values, at the same approximate LET, for different charged particles, the possibility exists that LET by itself is not a fully adequate descriptor for biological response, and physical characteristics such as mass, charge, or velocity may also be of great importance

  4. 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. PMID:25791963

  5. 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.

  6. Everyday problem solving across the adult life span: solution diversity and efficacy.

    Science.gov (United States)

    Mienaltowski, Andrew

    2011-10-01

    Everyday problem solving involves examining the solutions that individuals generate when faced with problems that take place in their everyday experiences. Problems can range from medication adherence and meal preparation to disagreeing with a physician over a recommended medical procedure or compromising with extended family members over where to host Thanksgiving dinner. Across the life span, research has demonstrated divergent patterns of change in performance based on the type of everyday problems used as well as based on the way that problem-solving efficacy is operationally defined. Advancing age is associated with worsening performance when tasks involve single-solution or fluency-based definitions of effectiveness. However, when efficacy is defined in terms of the diversity of strategies used, as well as by the social and emotional impact of solution choice on the individual, performance is remarkably stable and sometimes even improves in the latter half of life. This article discusses how both of these approaches to everyday problem solving inform research on the influence that aging has on everyday functioning. PMID:22023569

  7. Cancer risk among atomic bomb survivors. The RERF Life Span Study. Radiation Effects Research Foundation.

    Science.gov (United States)

    Shimizu, Y; Schull, W J; Kato, H

    1990-08-01

    This article summarizes the risk of cancer among the survivors of the atomic bombing of Hiroshima and Nagasaki. We focus primarily on the risk of death from cancer among individuals in the Life Span Study sample of the Radiation Effects Research Foundation from 1950 through 1985 based on recently revised dosimetry procedures. We report the risk of cancer other than leukemia among the atomic bomb survivors. We note that the number of excess deaths of radiation-induced malignant tumors other than leukemia increases with age. Survivors who were exposed in the first or second decade of life have just entered the cancer-prone age and have so far exhibited a high relative risk in association with radiation dose. Whether the elevated risk will continue or will fall with time is not yet clear, although some evidence suggests that the risk may be declining. It is important to continue long-term follow-up of this cohort to document the changes with time since exposure and to provide direct rather than projected risks over the lifetime of an exposed individual. PMID:2366300

  8. 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.

  9. 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.

  10. [Information theory of ageing: studying the effect of bone marrow transplantation on the life span of mice].

    Science.gov (United States)

    Karnaukhov, A V; Karnaukhova, E V; Sergievich, L A; Karnaukhova, N A; Karnaukhova, N A; Bogdanenko, E V; Smirnov, A A; Manokhina, I A; Karnaukhov, V N

    2014-01-01

    In this paper the method of life span extension of multicellular organisms (human) using the reservation of stem cells followed by autotransplantation has been proposed. As the efficiency of this method results from the information theory of ageing, it is important to verify it experimentally testing the basic concepts of the theory. Taking it into consideration, the experiment on the bone marrow transplantation to old mice from young closely-related donors of the inbred line was carried out. It has been shown, that transplanted animals exhibited a survival advantage, a mean life span increased by 34% as compared to the control. This result not only demonstrates the efficiency of the proposed method for life span extension of multicellular organisms, but also confirms the basis of the information theory of ageing. PMID:25707248

  11. Mortality pattern and life span in case of combined effect of incorporated radioisotopes, smoking and ethanol in the experiment

    International Nuclear Information System (INIS)

    It is established that life span and mortality pattern of animals subjected to chronic intake of 90Sr, to the effect of ethanol, and smoking depend on the intensity of radiation and radiation doses, character of harmful factors, age and sex dependences. The mean life span of animals subjected to the combined effect of 90Sr(10-3 LD50/30) of ethanol and smoking was by 18-22 % lower in comparison with intact animals. Alongside with the mean life span decrease latent period of carcinogenesis is shortened. A high tendency to metastases formation was noted in case of combined action of these factors than in comparison with isolated effect of them. 3 refs.; 1 tab

  12. Investigating the life-span of cork products for household and personal use through a longitudinal approach with users

    OpenAIRE

    Pereira, Ana Carina da Silva

    2014-01-01

    Doutoramento em Engenharia do Ambiente - Instituto Superior de Agronomia Products with a long life-span are important to reduce resources consumption and outflows to the environment. Cork has an interesting eco-profile since it is a natural non-wood forest product that can be produced without endangering the cork oak vitality. The aim of the work is to investigate the life-span of cork products. A total of 18 different cork products including household and personal use products were studie...

  13. Effects of x-irradiation of young female beagles on life span and tumor incidence

    International Nuclear Information System (INIS)

    Causes of death and the occurrence of neoplasia in female beagle dogs were evaluated retrospectively for 57 unexposed and 296 exposed dogs given single or fractionated whole-body x-irradiation exposures of 100 or 300 R. Some dogs subsequently were bred, and all were observed for the duration of their lives. The pathology for these dogs was derived from clinical records, gross-necropsy reports, tissue slides, and Formalin-fixed tissues. The results of this study indicated dose-related shortening of life span was clearly evident; causes of death due to either neoplasia (50%) or nonneoplastic disease (50%), with few exceptions, were similar in control and irradiated dogs; the incidences of neoplasms were not significantly greater for irradiated dogs than for controls, but the latency period decreased as dose increased; protraction increased survival in dogs given 300 R but not 100 R, which is attributable solely to amelioration of incidence rates of nonmammary neoplasia; and the cumulative rates of death due to mammary tumors were the same in dogs exposed to 100 R and 300 R. 14 refs., 6 figs., 2 tabs

  14. Leukemia incidence in the atomic bomb survivor Life Span Study, 1950 - 87

    International Nuclear Information System (INIS)

    The Radiation Effects Research Foundation (RERF) is currently preparing a series of reports on cancer incidence in the Life Span Study (LSS) cohort of atomic bomb survivors for the period from 1950 to 1987. One of these reports will present analyses of the data on the risk of hematopoietic cancers including leukemia, malignant lymphoma, and multiple myeloma. These analyses add an additional 11 years of follow-up to the previous comprehensive analysis of the LSS leukemia data. In this presentation, these data are presented and the methods being used modeling the leukemia risks are outlined. An analysis of the leukemia data pooled over subtypes will be used to illustrate these methods. It is shown that the data suggest a non-linear, concave upward dose response and that the temporal pattern of the radiation-induced excess absolute risks (EARs) depends on age-at-exposure and sex. There is no evidence of city differences in the EAR in this pooled analysis. The results suggest that the EARs for the youngest survivors were initially much higher and have declined more rapidly than those for older survivors. The same general pattern is seen both sexes, but the initial peak incidence is somewhat lower and the rate of decline less rapid for women than for men. (author)

  15. 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.

  16. Human-figure drawing and memory functioning across the adult life span.

    Science.gov (United States)

    Ericsson, K; Winblad, B; Nilsson, L -G.

    2001-03-01

    The main objective was to evaluate changes in the ability to draw the human figure (HFD) across adult life span and to relate these changes to those known to exist in memory function. Healthy adults (1000) from each of 10 five-year cohorts between 35 and 80 years were recruited randomly from a population in northern Sweden. Each participant was administered a health examination including cognitive testing and a drawing test, and an extensive examination of memory functions. For the drawing variables HFDarch and HFDtot, there is a steady decrease in episodic memory with poor drawers performing at a lower level. For semantic memory up to 65 years of age, there is no difference in performance, but thereafter a decrease. Good drawers show a better memory performance than poor drawers. For priming data for both HFDarch and HFDtot, there seems to be an interaction between age and drawing, such that poor drawers perform at a lower level for the two oldest groups but not for the youngest group. The HFDess is a valuable instrument and can support clinical evaluation as a screening for cognitive decline. The reduction of essential body details was strongly related to dementia progression, and thus as good a predictor of cognitive decline as episodic memory performance. The reduced capacity to perform a complex HFD declines with age and is most pronounced in the oldest age groups. PMID:11313105

  17. 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. PMID:27481911

  18. A Fasting-Responsive Signaling Pathway that Extends Life Span in C. elegans

    Directory of Open Access Journals (Sweden)

    Masaharu Uno

    2013-01-01

    Full Text Available Intermittent fasting is one of the most effective dietary restriction regimens that extend life span in C. elegans and mammals. Fasting-stimulus responses are key to the longevity response; however, the mechanisms that sense and transduce the fasting stimulus remain largely unknown. Through a comprehensive transcriptome analysis in C. elegans, we find that along with the FOXO transcription factor DAF-16, AP-1 (JUN-1/FOS-1 plays a central role in fasting-induced transcriptional changes. KGB-1, one of the C. elegans JNKs, acts as an activator of AP-1 and is activated in response to fasting. KGB-1 and AP-1 are involved in intermittent fasting-induced longevity. Fasting-induced upregulation of the components of the SCF E3 ubiquitin ligase complex via AP-1 and DAF-16 enhances protein ubiquitination and reduces protein carbonylation. Our results thus identify a fasting-responsive KGB-1/AP-1 signaling pathway, which, together with DAF-16, causes transcriptional changes that mediate longevity, partly through regulating proteostasis.

  19. Effects of kaolin particle films on the life span of an orb-weaver spider.

    Science.gov (United States)

    Benhadi-Marín, Jacinto; Pereira, José Alberto; Santos, Sónia A P

    2016-02-01

    Araniella cucurbitina (Araneae: Araneidae) is a widespread orb-weaver spider commonly found in agroecosystems. Mineral particle films such as kaolin, due to their protective or anti-feeding action, can represent an alternative to pesticides, especially in organic farming systems, but little is known about its effects on A. cucurbitina. Therefore, we tested the effect of kaolin sprays on the life span of A. cucurbitina under laboratory conditions. Four treatments were tested encompassing different exposure routes. Thus, kaolin sprays were applied on (i) the surface, (ii) the prey (fly), (iii) the spider and (iv) both spider & prey. A control group was tested with water in each treatment. Results showed that sprays of kaolin significantly affected the survival of A. curcubitina when applications were done on the surface and on both spider & prey registering a reduction of 48% and 56%, respectively. Spiders in control obtained higher probability of reaching alive at the end of the assay than those treated with kaolin. Differences observed can be explained by the feeding behavior of the species and may depend on the consumption of the web by the spider and the ratio spider/fly for body size. PMID:26432533

  20. Effects of kaolin particle films on the life span of an orb-weaver spider.

    Science.gov (United States)

    Benhadi-Marín, Jacinto; Pereira, José Alberto; Santos, Sónia A P

    2016-02-01

    Araniella cucurbitina (Araneae: Araneidae) is a widespread orb-weaver spider commonly found in agroecosystems. Mineral particle films such as kaolin, due to their protective or anti-feeding action, can represent an alternative to pesticides, especially in organic farming systems, but little is known about its effects on A. cucurbitina. Therefore, we tested the effect of kaolin sprays on the life span of A. cucurbitina under laboratory conditions. Four treatments were tested encompassing different exposure routes. Thus, kaolin sprays were applied on (i) the surface, (ii) the prey (fly), (iii) the spider and (iv) both spider & prey. A control group was tested with water in each treatment. Results showed that sprays of kaolin significantly affected the survival of A. curcubitina when applications were done on the surface and on both spider & prey registering a reduction of 48% and 56%, respectively. Spiders in control obtained higher probability of reaching alive at the end of the assay than those treated with kaolin. Differences observed can be explained by the feeding behavior of the species and may depend on the consumption of the web by the spider and the ratio spider/fly for body size.

  1. [Intention for self-change across the life span: Focusing on concern about self-change].

    Science.gov (United States)

    Chishima, Yuta

    2016-06-01

    The purpose of the present study was to examine intention for self-change across the life span using measures of self-esteem, frequency of self-reflection, and concern about self-change. We hypothesized that: (a) Intention for self-change decreases with age because of increased self-esteem, decreased self-reflection and concern about self-change, and (b) Associations among self-esteem, frequency of self-reflection, and intention for self-change are mediated by concern about self-change. Participants (N = 997; age range, 15 to 69 yrs) completed an internet survey. ANOVA results suggested that intention for self-change, concern about self-change, and frequency of self-reflection decreased with age, and that self-esteem-scores increased with age. Simultaneous analysis of multiple age groups showed that for all groups of low self-esteem and frequent self-reflection promoted intention for self-change and that there were significant mediating effects for concern about self-change. Therefore, these findings supported out research hypotheses. PMID:27476265

  2. Long will they live, work and learn. A scheme for understanding and influencing employability during the life span

    NARCIS (Netherlands)

    Nauta, Aukje; de Lange, Annet H.; Gortz, Saskia

    2010-01-01

    Long will they live, work and learn. A scheme for understanding and influencing employability during the life span A. Nauta, A. H. de Lange en S. Gortz, Gedrag & Organisatie, volume 23, June 2010, nr. 2, pp. 136-157 To stimulate employees' employability until high age, knowledge is needed about what

  3. Estimating age-dependent costs and benefits of roots with contrasting life span: comparing apples and oranges

    NARCIS (Netherlands)

    Bouma, T.J.; Yanai, R.D.; Elkin, A.D.; Hartmond, U.; Flores-Alva, D.E.; Eissenstat, D.M.

    2001-01-01

    The relation between root age and root function is poorly understood, despite its importance to root longevity. The effect of root age on respiration rates and P-32-uptake kinetics was determined for roots excavated from mature apple and citrus trees (median root life spans of 30 vs 300 d). To evalu

  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. Use of linear model analysis techniques in the evaluation of radiation effects on the life span of the beagle

    International Nuclear Information System (INIS)

    The dependency of the beagle-dog life span on level of and age at exposure to 60Co gamma radiation was analyzed by several techniques; one of these methods was linear model analysis. Beagles of both sexes were given single, bilateral exposures at 8, 28, or 55 days postcoitus (dpc) or at 2, 70, or 365 days postpartum (dpp). Dogs exposed at 8, 28, or 55 dpc or at 2 dpp received 0, 20, or 100 R, whereas those exposed at 70 or 365 dpp received 0 or 100 R. Beagles were designated initially either as sacrifice or as life-span animals. All deaths of life-span study animals were classified as spontaneous, hence for this group the mean age of death was a quantitative response that can be analyzed by linear model analysis techniques. Such analyses for each age group were performed, taking into account differences due to sex, linear and quadratic dependency on dose, and interaction between sex and dose. At this time most of the animals have reached 11 years of age. No significant effects of radiation on mean life span have been detected. 6 refs., 3 figs., 3 tabs

  7. Dispersal and life span spectra in plant communities : a key to safe site dynamics, species coexistence and conservation

    NARCIS (Netherlands)

    Strykstra, RJ; Bekker, RM; Van Andel, J

    2002-01-01

    Dispersal and life span of individual plant species within five plant communities were assessed to obtain a characterization of these communities in this respect. Such a characterization is important in the context of restoration and maintenance. The most frequent species of five communities were ra

  8. The Motivation Theory of Life-span Development%毕生发展动机理论述评

    Institute of Scientific and Technical Information of China (English)

    曹钰舒; 贺雯

    2012-01-01

    毕生发展动机理论以毕生发展理论和毕生发展控制理论为基础,通过整合初级与次级控制最优化模型与发展规律的行为阶段模型,发展出一套综合性的理论观点。本文对毕生发展动机理论的主要观点、内容、应用领域以及未来研究方向进行阐述,并与双重过程模型理论和SOC模型理论进行了分析比较。%The motivation theory of life-span development is based on the theory of life-span development and the life-span theory of control. Through integrating the model of optimization in primary and secondary control and the action-phase model of developmental regulation, the researchers develop a comprehensive set of theory perspectives. The main ideas, the content, the areas of application and the future research areas of the motivation theory of life-span development are set out in this article. In addition, this theory is compared with the theory of dual-process model and the theory of selection optimization and compensation (SOC) model.

  9. 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.

  10. 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. PMID:23429722

  11. 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 $lambda=0$.

  12. 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…

  13. LIFE-SPAN OF CLASSICAL SOLUTIONS OF INITIAL-BOUNDARY VALUE PROBLEM FOR FIRST ORDER QUASILINEAR HYPERBOLIC SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Lu Hong

    2007-01-01

    In this paper, we consider the mixed initial-boundary value problem for quasilinear hyperbolic systems with nonlinear boundary conditions in a half-unbounded domain {(t, x)| t ≥ 0, x≥ 0}. Under the assumption that the positive eigenvalues are not all weakly linearly degenerate,we obtain the blow-up phenomenon of the first order derivatives of C1 solution with small and decaying initial data. We also give precise estimate of the life-span of C1 solution.

  14. 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

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

    Science.gov (United States)

    Chen, Lan; Zhang, Ju; 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

  16. Moral development and perceptual role-taking egocentrism: their development and interrelationship across the life-span.

    Science.gov (United States)

    Del Vento Bielby, D; Papalia, D E

    1975-01-01

    Moral judgments and perceptual role taking egocentrism were assessed in seventy-two middle-class people whose age range encompassed a significant portion of the life span. Findings support the anticipated curvilinear relationship between moral development and age, and egocentrism and age. However, the close conceptual development and age, and egocentrism and age. However, the close conceptual relationship between moral development and egocentrism throughout life received only slight statistical support, which attained significance only in the fifteen- to nineteen-year-old age group. The existence of "self-involving" egocentrism was postulated to be an important determinant or moral development during adulthood. PMID:1221055

  17. 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

  18. Circadian rhythms of body temperature and locomotor activity in aging BALB/c mice: early and late life span predictors.

    Science.gov (United States)

    Basso, Andrea; Del Bello, Giovanna; Piacenza, Francesco; Giacconi, Robertina; Costarelli, Laura; Malavolta, Marco

    2016-08-01

    Impairment of one or more parameters of circadian rhythms (CR) of body temperature (BT) and locomotor activity (LMA) are considered among the hallmarks of mammalian aging. These alterations are frequently used as markers for imminent death in laboratory mice. However, there are still contradictory data for particular strains and it is also uncertain which changes might predict senescence changes later in life, including the force of mortality. In the present paper we use telemetry to study LMA and CR of BT during aging of BALB/c mice. At our knowledge this is the first time that CR of BT and LMA are investigated in this strain in a range of age covering the whole lifespan, from young adult up to very old age. CR of BT was analyzed with a cosine model using a cross sectional approach and follow-up measurements. The results show that BT, LMA, amplitude, goodness-of-fit (GoF) to circadian cycle of temperature decrease with different shapes during chronological age. Moreover, we found that the % change of amplitude and BT in early life (5-19 months) can predict the remaining lifespan of the mice. Later in life (22-32 months), best predictors are single measurements of LMA and GoF. The results of this study also offer potential measures to rapidly identifying freely unrestrained mice with the worst longitudinal outcome and against which existing or novel biomarkers and treatments may be assessed. PMID:26820297

  19. Quantitative proteomics of rat livers shows that unrestricted feeding is stressful for proteostasis with implications on life span

    Science.gov (United States)

    Pinto, Galit; Quadroni, Manfredo; Shtaif, Biana; Goloubinoff, Pierre

    2016-01-01

    Studies in young mammals on the molecular effects of food restriction leading to prolong adult life are scares. Here, we used high-throughput quantitative proteomic analysis of whole rat livers to address the molecular basis for growth arrest and the apparent life-prolonging phenotype of the food restriction regimen. Over 1800 common proteins were significantly quantified in livers of ad libitum, restriction- and re-fed rats, which summed up into 92% of the total protein mass of the cells. Compared to restriction, ad libitum cells contained significantly less mitochondrial catabolic enzymes and more cytosolic and ER HSP90 and HSP70 chaperones, which are hallmarks of heat- and chemically-stressed tissues. Following re-feeding, levels of HSPs nearly reached ad libitum levels. The quantitative and qualitative protein values indicated that the restriction regimen was a least stressful condition that used minimal amounts of HSP-chaperones to maintain optimal protein homeostasis and sustain optimal life span. In contrast, the elevated levels of HSP-chaperones in ad libitum tissues were characteristic of a chronic stress, which in the long term could lead to early aging and shorter life span. PMID:27508340

  20. 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。

  1. 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

  2. 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.

  3. 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

  4. 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 PMID:27267222

  5. Life-span studies in 226Ra-injected animals: Effect of low doses, effect of a decorporative treatment

    International Nuclear Information System (INIS)

    A life-span radiation effects study was performed in mice injected with several doses of 226Ra. The study included 788 male C57Bl mice. For the removal of the 226Ra, half the mice were treated daily with a diet 5% of which was sodium-alginate. The experiment revealed that mice that received the lowest dose of 226Ra lived significantly longer than controls, and, despite appreciable skeletal removal of 226Ra as a result of decorporative treatment, no biological benefit was observed in treated animals. 19 refs., 4 figs., 3 tabs

  6. 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

  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). PMID:19273990

  8. Antecedent life events of binge-eating disordspan>er

    OpenAIRE

    Pike, Kathleen M.; Wilfley, Denise; Hilbert, Anja; Fairburn, Christopher G.; Dohm, Faith-Anne; Striegel-Moore, Ruth H

    2006-01-01

    The present study investigated the occurrence of life events preceding the onset of disturbed eating in binge-eating disorder (BED). In a case-control design, 162 matched pairs of black and white women with BED and women with no current psychiatric disorder, and 107 matched pairs of women with BED and a current general psychiatric disorder were recruited from the community for the New England Women's Health Project. Life events in the year before the onset of disturbed eating were assessed re...

  9. 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.

  10. Bmi-1 extends the life span of normal human oral keratinocytes by inhibiting the TGF-β signaling

    International Nuclear Information System (INIS)

    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-β signaling pathway. Serial subculture of NHOK resulted in replicative senescence and terminal differentiation and activation of TGF-β signaling pathway. This was accompanied with enhanced intracellular and secreted TGF-β1 levels, phosphorylation of Smad2/3, and increased expression of p15INK4B and p57KIP2. An ectopic expression of Bmi-1 in NHOK (HOK/Bmi-1) decreased the level of intracellular and secreted TGF-β1 induced dephosphorylation of Smad2/3, and diminished the level of p15INK4B and p57KIP2. Moreover, Bmi-1 expression led to the inhibition of TGF-β-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, p15INK4B, and p57KIP2. In addition, an exposure of senescent NHOK to TGF-β receptor I kinase inhibitor or anti-TGF-β antibody resulted in enhanced replicative potential of cells. Taken together, these data suggest that Bmi-1 suppresses senescence of cells by inhibiting the TGF-β signaling pathway in NHOK.

  11. 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.

  12. 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.

  13. Trade-offs between seed output and life span - a quantitative comparison of traits between annual and perennial congeneric species.

    Science.gov (United States)

    Vico, Giulia; Manzoni, Stefano; Nkurunziza, Libère; Murphy, Kevin; Weih, Martin

    2016-01-01

    Perennial plants allocate more resources belowground, thus sustaining important ecosystem services. Hence, shifting from annual to perennial crops has been advocated towards a more sustainable agriculture. Nevertheless, wild perennial species have lower seed production than selected annuals, raising the questions of whether there is a fundamental trade-off between reproductive effort and life span, and whether such trade-off can be overcome through selection. In order to address these questions and to isolate life span from phylogenetic and environmental factors, we conducted a meta-analysis encompassing c. 3000 congeneric annual/perennial pairs from 28 genera. This meta-analysis is complemented with a minimalist model of long-term productivity in perennial species. Perennials allocate more resources belowground and less to seeds than congeneric annuals, independently of selection history. However, existing perennial wheat and rice could achieve yields similar to annuals if they survived three years and each year doubled their biomass, as other perennial grasses do. Selected perennial crops maintain the large belowground allocation of wild perennials, and thus can provide desired regulatory ecosystem services. To match the seed yield of annuals, biomass production of perennial grains must be increased to amounts attained by some perennial grasses - if this goal can be met, perennial crops can provide a more sustainable alternative to annuals. PMID:26214792

  14. Baicalein modulates stress-resistance and life span in C. elegans via SKN-1 but not DAF-16.

    Science.gov (United States)

    Havermann, Susannah; Humpf, Hans-Ulrich; Wätjen, Wim

    2016-09-01

    The flavonoid baicalein has been demonstrated to be an activator of the transcription factor Nrf2 in mammalian cell lines. We show that it further modulates the Nrf2 homolog SKN-1 in Caenorhabditis elegans and by this pathway mediates beneficial effects in the nematode: baicalein enhances the resistance of C. elegans against lethal thermal and sodium arsenite stress and dose-dependently prolongs the life span of the nematode. Using RNA interference against SKN-1 we were able to show that the induction of longevity and the enhanced stress-resistance were dependent on this transcription factor. DAF-16 (homolog to mammalian FOXO) is another pivotal aging-related transcription factor in the nematode. We demonstrate that DAF-16 does not participate in the beneficial effects of baicalein: since baicalein causes no increase in the nuclear translocation of DAF-16 (DAF-16::GFP expressing strain, incubation time: 1h) and it still induces longevity even in a DAF-16 loss-of-function strain, we conclude, that baicalein increases stress-resistance and life span in C. elegans via SKN-1 but not DAF-16. PMID:27370100

  15. 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,

  16. Motives in American Men and Women across the Adult Life Span.

    Science.gov (United States)

    Veroff, Joseph; And Others

    1984-01-01

    Investigates stability and change in four social motives (achievement, affiliation, fear of weakness, hope of power) over the adult life cycle. Motives were assessed in 1957 and 1976 by coding thematic apperceptive content in stories told about six pictures. Some age differences and cohort stability were evident for both sexes. (Author/CB)

  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. Sex differences in the effects of cocaine abuse across the life span

    OpenAIRE

    Dow-Edwards, Diana

    2010-01-01

    Cocaine alters brain function from the early days of development throughout the entire life of an individual. Since the first preclinical research on cocaine sensitization was published, sex differences in response to the drug in adult rats have been noted. With the appearance of reports on “crack babies” during the 1980’s, sex differences in response to prenatal (developmental) exposure have been identified in both clinical and preclinical reports. Cocaine administered during early developme...

  19. Late effects of selected immunosuppressants on immunocompetence, disease incidence, and mean life-span. III. Disease incidence and life expectancy. [Mice, x radiation

    Energy Technology Data Exchange (ETDEWEB)

    Peter, C.P.; Perkins, E.H.; Peterson, W.J.; Walburg, H.E.; Makinodan, T.

    1975-01-01

    The effect of various immunosuppressive treatments on mean life-span and disease incidence have been studied. Significant life shortening was seen only in mice which received X-irradiation early in life and can be ascribed primarily to an increased incidence of certain malignancies. Marginal life shortening was seen in cyclophosphamide-treated animals, however, survival patterns between those and control animals did not differ until 30 months of age and the magnitude of life-shortening never approached that seen in X-irradiated animals. Thymectomy, splenectomy or cortisone treatment did not alter survival. All immunosuppressive treatments enhanced mortality due to non-neoplastic diseases, however, only a small percentage of animals die with these disease entities. With the exception of cortisone all immunosuppressive treatments increased the incidence of neoplastic disease. However, their effects on various neoplastic processes were variable and unpredictable. Four primary patterns in terms of relative immune competence, disease incidence and life expectancy were seen. Thus, immunodepression may or may not correlate with increased disease incidence, which in turn may or may not have a life-shortening effect. These findings are discussed in terms of the marked reduction of both humoral and cell-mediated immunity normally seen in aged mice and the significance of postulated immune surveillance mechanisms to survival.

  20. 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.

  1. 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.

  2. Tissue characteristics of high- and low-incidence plutonium-induced osteogenic sarcoma sites in life-span beagles

    International Nuclear Information System (INIS)

    On the basis of information gathered from the 239Pu life-span study in beagles at the University of Utah, the tissue features were found to be characteristic of high-incidence bone-tumor sites compared to low-incidence sites included more hematopoietic tissues in the bone marrow; greater trabecular bone mass; greater bone remodeling rates; greater mineral apposition rates; greater density and activity of bone surface cells; greater density of putative bone-cell precursors; greater initial uptake of plutonium on bone surfaces; and greater marrow vascular volumes and a venous sinusoidal bed. Although most of these studies are not yet complete, the information being collected should contribute to our understanding of the mechanisms of radiation-induced osteogenic sarcomas. This should aid in predicting the types and characteristics of osseous tissues where radiation-induced osteogenic sarcomas may arise in humans. 25 refs., 4 figs., 3 tabs

  3. 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

    of inbreeding effects in specific traits, such as age-specific mortality and life span, provide a good starting point, as a limited set of genes is expected to be involved. Results Here we report on a QTL mapping study on inbreeding related and temperature sensitive lethality in male Drosophila melanogaster....... The inbreeding effect was expressed at moderately high temperature, and manifested itself as severe premature mortality in males, but not in females. We used a North Carolina crossing design 3 to estimate average dominance ratio and heritability. We found the genetic basis of the lethal effect to be relatively...... This demonstrates that analysis of large conditional lethal effects is a viable strategy for delineating genes which are sensitive to inbreeding depression....

  4. Curiosity and stimulation seeking across the adult life span: cross-sectional and 6- to 8-year longitudinal findings.

    Science.gov (United States)

    Giambra, L M; Camp, C J; Grodsky, A

    1992-03-01

    Giambra (1977-1978, 1979-1980) found that 2 scales of the Imaginal Processes Inventory measuring curiosity (i.e., information seeking) did not change across the adult life span, but 2 measuring stimulation seeking (i.e., boredom) for external stimulation need significantly decreased with age. In this study, these outcomes were replicated (1,356 men and 1,080 women 17 to 92 years old). In addition, a 6- to 8-year longitudinal repeat was obtained on 222 men and 124 women. Significant longitudinal declines were obtained for the stimulation-seeking measures. Furthermore, women showed an increase in impersonal-mechanical curiosity and a decline in interpersonal curiosity, though the amount of change was modest. Men were unchanged on both curiosity measures. Gender differences in longitudinal changes apparently reflected effects of socialization as well as tendencies toward displaying increased androgyny with advancing age. PMID:1558700

  5. 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.

  6. 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.

  7. Effect and Mechanism of Ginsenoside Rg3 on Postoperative Life Span of Patients with Non-Small Cell Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    LU Ping; SU Wei; MIAO Zhan-hui; NIU Hong-rui; LIU Jing; HUA Qin-liang

    2008-01-01

    Objective: To explore the effect and mechanism of ginsenoside Rg3 (Shenyi Capsule,参一胶囊) on the postoperative life span of patients with non-small cell lung cancer (NSCLC). Methods: The prospective, randomized, controlled method was adopted. One hundred and thirty- three patients with NSCLC were randomly assigned to 3 groups: Shenyi Capsule group (43 cases), combined therapy group (Shenyi Capsule plus chemotherapy, 46 cases), and chemotherapy group (44 cases). The survival rates, immune function and the correlation between vascular endothelial growth factor (VEGF) expression and clinical effect were analyzed in the three groups. Results: (1) The 1-year survival rate in the Shenyi group, the combined group and the chemotherapy group was 76.7% (33/43), 82.6% (38/46), and 79.5% (35/44), respectively; the 2-year survival rate was 67.4% (29/43), 71.7% (33/46), and 70.5% (31/44), respectively; and the 3-year survival rate was 46.5% (20/43), 54.3% (25/46), and 47.7% (21/44), respectively. There was no significant difference among the 3 groups (P>0.05). (2) NK cells were increased to different degrees and the ratio of CD4/CD8 was normal in the Shenyi Capsule group and the combined group, while the ratio of CD4/CD8 was disproportional in the chemotherapy group. (3) In the chemotherapy group, the 3-year survival rate was lower in patients with positive expression of VEGF than in patients with negative expression (37.0% vs 64.7%, ~ 2=17.9, P0.05; 44.4% vs 50.0%, P>0.05). Conclusion: Shenyi Capsule, especially in combination with chemotherapy, can improve the life span of patients with NSCLC after operation. The mechanism might be correlated with improving the immune function and anti-tumor angiogenesis.

  8. Sex differences in the effects of cocaine abuse across the life span.

    Science.gov (United States)

    Dow-Edwards, Diana

    2010-06-01

    Cocaine alters brain function from the early days of development throughout the entire life of an individual. Since the first preclinical research on cocaine sensitization was published, sex differences in response to the drug in adult rats have been noted. With the appearance of reports on "crack babies" during the 1980s, sex differences in response to prenatal (developmental) exposure have been identified in both clinical and preclinical reports. Cocaine administered during early development in the rat produces wide-spread alterations in function which depend on the timing of drug administration as well as the sex of the animal. In males, the response patterns following postnatal days (PND) 11-20 cocaine administration (equivalent to the late prenatal period in humans) are quite similar to those seen following prenatal exposure (equivalent to the first half of pregnancy in humans). There is a general decrease in dopaminergic (DA) markers and reactivity perhaps due to the uncoupling of the D1 receptor from its second messenger system. While similar changes in D1 uncoupling are seen in females, behavioral and metabolic responses to drug challenges generally show increases in DA responsivity (except adolescents) perhaps due to the activational effects of estrogen and/or decreases in serotonin (5-HT) mediated regulation of DA function. We have found that a significant factor in the hyper-responsivity of the female is the role of the testing environment and the responses to stress which can obscure underlying neurochemical dysregulation. Whether parallel factors are operational in adult males and females is currently under investigation. PMID:20045010

  9. [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

  10. Implications of extreme life span in clonal organisms: millenary clones in meadows of the threatened seagrass Posidonia oceanica.

    Directory of Open Access Journals (Sweden)

    Sophie Arnaud-Haond

    Full Text Available The maximum size and age that clonal organisms can reach remains poorly known, although we do know that the largest natural clones can extend over hundreds or thousands of metres and potentially live for centuries. We made a review of findings to date, which reveal that the maximum clone age and size estimates reported in the literature are typically limited by the scale of sampling, and may grossly underestimate the maximum age and size of clonal organisms. A case study presented here shows the occurrence of clones of slow-growing marine angiosperm Posidonia oceanica at spatial scales ranging from metres to hundreds of kilometres, using microsatellites on 1544 sampling units from a total of 40 locations across the Mediterranean Sea. This analysis revealed the presence, with a prevalence of 3.5 to 8.9%, of very large clones spreading over one to several (up to 15 kilometres at the different locations. Using estimates from field studies and models of the clonal growth of P. oceanica, we estimated these large clones to be hundreds to thousands of years old, suggesting the evolution of general purpose genotypes with large phenotypic plasticity in this species. These results, obtained combining genetics, demography and model-based calculations, question present knowledge and understanding of the spreading capacity and life span of plant clones. These findings call for further research on these life history traits associated with clonality, considering their possible ecological and evolutionary implications.

  11. 提高热风炉使用寿命的方法探讨%DISCUSSION ON LONGER LIFE-SPAN OF HOT-BLAST STOVE

    Institute of Scientific and Technical Information of China (English)

    孟凡双; 李东生

    2013-01-01

    Longer life-span of hot-blast stove is a systematic project , and normally the foundation for longer or shorter life-span of hot-blast stove is laid after the construction stage .This paper discusses how to ensure a stable operation and increase the life-span through adjusting the hot-blast stove operation pa-rameters in a reasonable way .%延长热风炉使用寿命的工作是一项系统工程,在热风炉建设完毕时,就为其寿命的长短奠定了基础。本文探讨了如何在生产运行过程中,通过合理调控其运行参数,确保热风炉的稳定运行,提高热风炉的使用寿命。

  12. 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.

  13. Lipopolysaccharide-induced inflammation attenuates taste progenitor cell proliferation and shortens the life span of taste bud cells

    Directory of Open Access Journals (Sweden)

    Brand Joseph

    2010-06-01

    Full Text Available Abstract Background The mammalian taste bud, a complex collection of taste sensory cells, supporting cells, and immature basal cells, is the structural unit for detecting taste stimuli in the oral cavity. Even though the cells of the taste bud undergo constant turnover, the structural homeostasis of the bud is maintained by balancing cell proliferation and cell death. Compared with nongustatory lingual epithelial cells, taste cells express higher levels of several inflammatory receptors and signalling proteins. Whether inflammation, an underlying condition in some diseases associated with taste disorders, interferes with taste cell renewal and turnover is unknown. Here we report the effects of lipopolysaccharide (LPS-induced inflammation on taste progenitor cell proliferation and taste bud cell turnover in mouse taste tissues. Results Intraperitoneal injection of LPS rapidly induced expression of several inflammatory cytokines, including tumor necrosis factor (TNF-α, interferon (IFN-γ, and interleukin (IL-6, in mouse circumvallate and foliate papillae. TNF-α and IFN-γ immunoreactivities were preferentially localized to subsets of cells in taste buds. LPS-induced inflammation significantly reduced the number of 5-bromo-2'-deoxyuridine (BrdU-labeled newborn taste bud cells 1-3 days after LPS injection, suggesting an inhibition of taste bud cell renewal. BrdU pulse-chase experiments showed that BrdU-labeled taste cells had a shorter average life span in LPS-treated mice than in controls. To investigate whether LPS inhibits taste cell renewal by suppressing taste progenitor cell proliferation, we studied the expression of Ki67, a cell proliferation marker. Quantitative real-time RT-PCR revealed that LPS markedly reduced Ki67 mRNA levels in circumvallate and foliate epithelia. Immunofluorescent staining using anti-Ki67 antibodies showed that LPS decreased the number of Ki67-positive cells in the basal regions surrounding circumvallate taste buds

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. A review of methionine dependency and the role of methionine restriction in cancer growth control and life-span extension.

    Science.gov (United States)

    Cavuoto, Paul; Fenech, Michael F

    2012-10-01

    Methionine is an essential amino acid with many key roles in mammalian metabolism such as protein synthesis, methylation of DNA and polyamine synthesis. Restriction of methionine may be an important strategy in cancer growth control particularly in cancers that exhibit dependence on methionine for survival and proliferation. Methionine dependence in cancer may be due to one or a combination of deletions, polymorphisms or alterations in expression of genes in the methionine de novo and salvage pathways. Cancer cells with these defects are unable to regenerate methionine via these pathways. Defects in the metabolism of folate may also contribute to the methionine dependence phenotype in cancer. Selective killing of methionine dependent cancer cells in co-culture with normal cells has been demonstrated using culture media deficient in methionine. Several animal studies utilizing a methionine restricted diet have reported inhibition of cancer growth and extension of a healthy life-span. In humans, vegan diets, which can be low in methionine, may prove to be a useful nutritional strategy in cancer growth control. The development of methioninase which depletes circulating levels of methionine may be another useful strategy in limiting cancer growth. The application of nutritional methionine restriction and methioninase in combination with chemotherapeutic regimens is the current focus of clinical studies.

  20. 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.

  1. 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…

  2. Life Span for a Fast Diffusion Equation%一类快速扩散方程解的生命跨度

    Institute of Scientific and Technical Information of China (English)

    王玉兰; 陈琼

    2003-01-01

    The authors study the Cauchy problem of a fast diffusion equation, and obtain the estimate of the life span of its soultion.%研究了一类快速扩散方程的Cauchy问题,给出了其解的生命跨度的估计.

  3. 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.

  4. 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.

  5. Insights into radionuclide-induced lung cancer in people from life-span studies in beagle dogs

    International Nuclear Information System (INIS)

    In life-span studies, beagle dogs were exposed one time by inhalation to an aerosol containing a beta- or alpha-emitting radionuclide in a relatively soluble or insoluble chemical form. After exposure dogs were observed for late-occurring biological effects. Lung cancer has been a predominant observation for radionuclides inhaled in a relatively insoluble form because most of the absorbed dose was delivered to the lung and contiguous tissues. Approximately 130 lung cancers were observed in dogs exposed to inhaled beta-emitting radionuclides; tumors occurred with absorbed doses to lung ranging from 1100 to 68,000 rads. With inhaled alpha emitters lung tumors occurred at doses between 530 and 8400 rads. Dose rate pattern was shown to be an important factor in the induction of lung cancer by inhaled beta emitters. Doses of low-LET irradiation delivered in a matter of days can be as much as 8 times more effective per unit of dose than radiation doses delivered over a more protracted period of time. Tumors also have occurred in tracheobronchial lymph nodes of dogs that inhaled relatively insoluble forms of beta emitters. From these studies, the risk of lung cancer from inhaled beta- or alpha-emitting radionuclides was compared to determine the importance of LET and other dose-effect modifying factors on resulting risks and on extrapolation to human inhalation exposure. Attention also was given to the risk of cancer in tracheobronchial lymph nodes, on the basis of the results of these studies and the current ICRP computational method in which lymph nodes are included with lung for purposes of dose and risk calculation. 12 refs., 3 figs., 4 tabs

  6. Low Six4 and Six5 gene dosage improves dystrophic phenotype and prolongs life span of mdx mice.

    Science.gov (United States)

    Yajima, Hiroshi; Kawakami, Kiyoshi

    2016-08-01

    Muscle regeneration is an important process for skeletal muscle growth and recovery. Repair of muscle damage is exquisitely programmed by cellular mechanisms inherent in myogenic stem cells, also known as muscle satellite cells. We demonstrated previously the involvement of homeobox transcription factors, SIX1, SIX4 and SIX5, in the coordinated proliferation and differentiation of isolated satellite cells in vitro. However, their roles in adult muscle regeneration in vivo remain elusive. To investigate SIX4 and SIX5 functions during muscle regeneration, we introduced knockout alleles of Six4 and Six5 into an animal model of Duchenne Muscular Dystrophy (DMD), mdx (Dmd(mdx) /Y) mice, characterized by frequent degeneration-regeneration cycles in muscles. A lower number of small myofibers, higher number of thick ones and lower serum creatine kinase and lactate dehydrogenase activities were noted in 50-week-old Six4(+/-) 5(+/-) Dmd(mdx) /Y mice than Dmd(mdx) /Y mice, indicating improvement of dystrophic phenotypes of Dmd(mdx) /Y mice. Higher proportions of cells positive for MYOD1 and MYOG (markers of regenerating myonuclei) and SIX1 (a marker of regenerating myoblasts and newly regenerated myofibers) in 12-week-old Six4(+/-) 5(+/-) Dmd(mdx) /Y mice suggested enhanced regeneration, compared with Dmd(mdx) /Y mice. Although grip strength was comparable in Six4(+/-) 5(+/-) Dmd(mdx) /Y and Dmd(mdx) /Y mice, treadmill exercise did not induce muscle weakness in Six4(+/-) 5(+/-) Dmd(mdx) /Y mice, suggesting higher regeneration capacity. In addition, Six4(+/-) 5(+/-) Dmd(mdx) /Y mice showed 33.8% extension of life span. The results indicated that low Six4 and Six5 gene dosage improved dystrophic phenotypes of Dmd(mdx) /Y mice by enhancing muscle regeneration, and suggested that SIX4 and SIX5 are potentially useful de novo targets in therapeutic applications against muscle disorders, including DMD. PMID:27224259

  7. Life span study report 11. part 3. noncancer mortality, 1950-85, based on the revised doses (DS86)

    International Nuclear Information System (INIS)

    Deaths in the RERF Life Span Study (LSS) sample have been determined for the years 1950-85 and previous reports have described analyses of cancer mortality using the revised Dosimetry System 1986 (DS86) doses (LSS Report 11, Parts 1 and 2). In this report, we examine the relationship to dose of deaths from all diseases other than cancer. Although the evidence is still limited, there seems to be an excess risk for noncancer death at high doses (2 or 3 Gy and over). Statistically, a pure quadratic or a linear-threshold model (the estimated threshold dose is 1.4 Gy [0.6-2.8 Gy] is found to fit better than a simple linear or linear-quadratic model. This increase in noncancer mortality is statistically demonstrable, generally, after 1965 and among the younger survivors (< 40) at the time of the bombings, suggesting a sensitivity in this age group. For specific causes of death, an excess relative risk at the high dose level, that is, ≥ 2 Gy, is seen in circulatory and digestive diseases. The relative risk is, however, much smaller than that for cancer. These findings, based as they are on death certificates, have their limitations. Most significant, perhaps, is the possible erroneous attribution of radiation-related cancer deaths to other causes. At present, the contribution such errors may make to the apparent increase in noncancer deaths at the high doses cannot be estimated as rigorously as is obviously desirable. However, even now, this increase does not appear to be fully explicable in terms of classificatory errors. (J.P.N.)

  8. 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.

  9. Deletion of Brca2 exon 27 causes hypersensitivity to DNA crosslinks, chromosomal instability, and reduced life span in mice

    Science.gov (United States)

    Donoho, Greg; Brenneman, Mark A.; Cui, Tracy X.; Donoviel, Dorit; Vogel, Hannes; Goodwin, Edwin H.; Chen, David J.; Hasty, Paul

    2003-01-01

    The Brca2 tumor-suppressor gene contributes to genomic stability, at least in part by a role in homologous recombinational repair. BRCA2 protein is presumed to function in homologous recombination through interactions with RAD51. Both exons 11 and 27 of Brca2 code for domains that interact with RAD51; exon 11 encodes eight BRC motifs, whereas exon 27 encodes a single, distinct interaction domain. Deletion of all RAD51-interacting domains causes embryonic lethality in mice. A less severe phenotype is seen with BRAC2 truncations that preserve some, but not all, of the BRC motifs. These mice can survive beyond weaning, but are runted and infertile, and die very young from cancer. Cells from such mice show hypersensitivity to some genotoxic agents and chromosomal instability. Here, we have analyzed mice and cells with a deletion of only the RAD51-interacting region encoded by exon 27. Mice homozygous for this mutation (called brca2(lex1)) have a shorter life span than that of control littermates, possibly because of early onsets of cancer and sepsis. No other phenotype was observed in these animals; therefore, the brca2(lex1) mutation is less severe than truncations that delete some BRC motifs. However, at the cellular level, the brca2(lex1) mutation causes reduced viability, hypersensitivity to the DNA interstrand crosslinking agent mitomycin C, and gross chromosomal instability, much like more severe truncations. Thus, the extreme carboxy-terminal region encoded by exon 27 is important for BRCA2 function, probably because it is required for a fully functional interaction between BRCA2 and RAD51. Copyright 2003 Wiley-Liss, Inc.

  10. 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.

  11. Subsea Pipeline Span Analysis Based on Fatigue Life%基于疲劳寿命的海底管道自由悬跨分析

    Institute of Scientific and Technical Information of China (English)

    李秀锋; 冯现洪

    2015-01-01

    Traditionally,span analysis determines the maximum allowable free span length based on the condition that no vortex induced vibration (VIV)will happen and the assumption of strength ultimate limit state (ULS).The cost of span mitigation rises rapidly with the increase of water depth.Free span analysis based on fatigue life could remarkably increase the maximum allowable span length and cut the engineering cost.We present the free span analysis method and criteria for subsea pipeline.Based on the engineering project which is the first time to use fatigue limit for pipeline design,the free span analysis is conducted by fatigue limit state (FLS)and finite element method,and the results minimize the number of span mitigation.%传统悬跨分析以不发生涡激振动和强度极限状态为原则确定最大可以接受的自由悬跨长度。随着水深的增加,悬跨处理的成本急剧增加,以疲劳寿命为准则可以显著地增加最大可接受悬跨长度,减少工程费用。介绍了海底管道设计过程中的悬跨分析方法和悬跨接受标准。提出在设计阶段以疲劳极限状态为接受标准,并结合有限元计算进行悬跨分析,可减少悬跨处理量,节约大量工程费用。

  12. 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

  13. Boundary Spanning

    DEFF Research Database (Denmark)

    Zølner, Mette

    in the period of post-acquisition when their organization is being integrated into the acquiring MNC. The paper contributes to the literature on boundary spanning in three ways: First, by illustrating that boundary spanning is performed by numerous organizational actors in a variety of positions in MNCs......, inclusively by locals in subsidiaries. Second, by showing that boundary spanning is ‘situated’ in the sense that its result depends on the kind of knowledge to be transmitted and the attitude of the receivers. A third contribution is methodological. The study illustrates that combining bottom-up grounded...

  14. A study on the energy civilization in the 21st century and the analysis of the span of life or the energy recourses

    International Nuclear Information System (INIS)

    This study should have been mainly composed of the pre-estimate of the future views on the balancing of energy demand and supply in the 21st century related to global environmental matters and the analysis of the span of life of the usable energy resources in the 21st century. Due to the project interruption by the PBS input, this study carried out partly the investigation and the analysis of energy demand supply, which regarded to economic circumstances and environmental control regulations. Therefore, this intermediate report shall be an important reference to analyze the span of practical life of the usable energy resources in order to improve the usable capability of energy utilization for the future. 14 refs. (Author)

  15. 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.

  16. 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. PMID:26433219

  17. From Suns to Life: A Chronological Approach to the History of Life on Earth 7. Ancient Fossil Record and Early Evolution (ca. 3.8 to 0.5 Ga)

    Science.gov (United States)

    López-Garcia, Purificacón; Moreira, David; Douzery, Emmanuel; Forterre, Patrick; van Zuilen, Mark; Claeys, Philippe; Prieur, Daniel

    2006-06-01

    Once life appeared, it evolved and diversified. From primitive living entities, an evolutionary path of unknown duration, likely paralleled by the extinction of unsuccessful attempts, led to a last common ancestor that was endowed with the basic properties of all cells. From it, cellular organisms derived in a relative order, chronology and manner that are not yet completely settled. Early life evolution was accompanied by metabolic diversification, i.e. by the development of carbon and energy metabolic pathways that differed from the first, not yet clearly identified, metabolic strategies used. When did the different evolutionary transitions take place? The answer is difficult, since hot controversies have been raised in recent years concerning the reliability of the oldest life traces, regardless of their morphological, isotopic or organic nature, and there are also many competing hypotheses for the evolution of the eukaryotic cell. As a result, there is a need to delimit hypotheses from solid facts and to apply a critical analysis of contrasting data. Hopefully, methodological improvement and the increase of data, including fossil signatures and genomic information, will help reconstructing a better picture of life evolution in early times as well as to, perhaps, date some of the major evolutionary transitions. There are already some certitudes. Modern eukaryotes evolved after bacteria, since their mitochondria derived from ancient bacterial endosymbionts. Once prokaryotes and unicellular eukaryotes had colonized terrestrial ecosystems for millions of years, the first pluricellular animals appeared and radiated, thus inaugurating the Cambrian. The following sections constitute a collection of independent articles providing a general overview of these aspects.

  18. 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.

  19. Effect of coenzyme Q10 intake on endogenous coenzyme Q content, mitochondrial electron transport chain, antioxidative defenses, and life span of mice.

    Science.gov (United States)

    Sohal, Rajindar S; Kamzalov, Sergey; Sumien, Nathalie; Ferguson, Melissa; Rebrin, Igor; Heinrich, Kevin R; Forster, Michael J

    2006-02-01

    The main purpose of this study was to determine whether intake of coenzyme Q10, which can potentially act as both an antioxidant and a prooxidant, has an impact on indicators of oxidative stress and the aging process. Mice were fed diets providing daily supplements of 0, 93, or 371 mg CoQ10 /kg body weight, starting at 3.5 months of age. Effects on mitochondrial superoxide generation, activities of oxidoreductases, protein oxidative damage, glutathione redox state, and life span of male mice were determined. Amounts of CoQ9 and CoQ10, measured after 3.5 or 17.5 months of intake, in homogenates and mitochondria of liver, heart, kidney, skeletal muscle, and brain increased with the dosage and duration of CoQ10 intake in all the tissues except brain. Activities of mitochondrial electron transport chain oxidoreductases, rates of mitochondrial O2-* generation, state 3 respiration, carbonyl content, glutathione redox state of tissues, and activities of superoxide dismutase, catalase, and glutathione peroxidase, determined at 19 or 25 months of age, were unaffected by CoQ10 administration. Life span studies, conducted on 50 mice in each group, showed that CoQ10 administration had no effect on mortality. Altogether, the results indicated that contrary to the historical view, supplemental intake of CoQ10 elevates the endogenous content of both CoQ9 and CoQ10, but has no discernable effect on the main antioxidant defenses or prooxidant generation in most tissues, and has no impact on the life span of mice.

  20. Application of a systematized nomenclature of veterinary medicine (SNOVET) to diagnostic coding and retrieval of clinical life-span data in beagle dogs exposed to plutonium

    International Nuclear Information System (INIS)

    A data-management system, utilizing the Systematized Nomenclature of Veterinary Medicine (SNOVET), was implemented to collect data generated by our life-span canine studies. Information is encoded and retrieved by specific categories. These data are analyzed statistically to look for significant effects related to exposure to radionuclides. Preliminary use for evaluation of the SNOVET system revealed statistically significant differences in survival between control and exposed animals. Also, there appears to be an increased risk of testicular and reproductive tract disorders with increasing dose. 8 refs., 3 figs., 2 tabs

  1. [The morphofunctional condition of the basic organ systems, life span and fecundity of the domestic cricket, Acheta domestica, during normal imaginal development and following allatectomy].

    Science.gov (United States)

    Chudakova, I V; Bocharova-Messner, O M; Romashkina, M P

    1975-01-01

    3 main periods of imaginal development: juvenility, reproduction, ageing, were established in Acheta domestica and characterized by morphological and functional features of some organs (integument, wings, fat body, wing muscles, ovaries, and body proportions). Allatectomized crickets remain in the first period up till the day of death; this allowed to suggest that the hormone of corpora allata in imago controls the normal correlated development of different organs and tissues and ensures the transition to subsequent periods of imaginal ontogenesis. In allatectomized crickets of both the sexes, the duration of imaginal life is markedly longer and the fecundity of females is much lower. It is suggested that the hormone of corpora allata controls the life span and the fecundity independently. PMID:1214983

  2. Extracts of Cistanche deserticola Can Antagonize Immunosenescence and Extend Life Span in Senescence-Accelerated Mouse Prone 8 (SAM-P8 Mice

    Directory of Open Access Journals (Sweden)

    Ke Zhang

    2014-01-01

    Full Text Available The senescence accelerated mouse prone 8 substrain (SAM-P8, widely accepted as an animal model for studying aging and antiaging drugs, was used to examine the effects of dietary supplementation with extracts of Cistanche deserticola (ECD which has been used extensively in traditional Chinese medicine because of its perceived ability to promote immune function in the elderly. Eight-month-old male SAM-P8 mice were treated with ECD by daily oral administrations for 4 weeks. The results showed that dietary supplementation of 150 mg/kg and 450 mg/kg of ECD could extend the life span measured by Kaplan-Meier survival analysis in dose-dependent manner. Dietary supplementation of SAM-P8 mice for 4 weeks with 100, 500, and 2500 mg/kg of ECD was shown to result in significant increases in both naive T and natural killer cells in blood and spleen cell populations. In contrast, peripheral memory T cells and proinflammatory cytokine, IL-6 in serum, were substantially decreased in the mice that ingested 100 and 500 mg/kg of ECD daily. Additionally, Sca-1 positive cells, the recognized progenitors of peripheral naive T cells, were restored in parallel. Our results provide clear experimental support for long standing clinical observational studies showing that Cistanche deserticola possesses significant effects in extending life span and suggest this is achieved by antagonizing immunosenescence.

  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. 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.

  5. 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

  6. Effects of α-lipoic Acid on the Life-span of Drosophila%α-硫辛酸对果蝇寿命的影响

    Institute of Scientific and Technical Information of China (English)

    尹志奎; 崔泰震; 崔旭; 李文彬; 郑风劲

    2004-01-01

    目的建立果蝇的半乳糖衰老模型,观察α-硫辛酸对果蝇寿命影响.方法将未交配的果蝇按性别随机分为四组:对照组、半乳糖组、α-硫辛酸低剂量组、α-硫辛酸高剂量组,观测果蝇平均寿命(Average Life Span, ALS)、果蝇最高寿命(Maximum Life Span, MLS)和果蝇半数死亡时间(LD50).结果 D-半乳糖组果蝇的生存曲线比对照组左移,具有显著性意义(P<0.01),LD50缩小; α-硫辛酸低剂量组、高剂量组生存曲线比对照组右移,具有显著性意义(P<0.05).结论 D-半乳糖可以诱导果蝇的衰老,α-硫辛酸能预防D-半乳糖诱导的果蝇衰老作用.

  7. Dead or alive: Deformed Wing Virus and Varroa destructor reduce the life span of winter honey bees

    Science.gov (United States)

    Elevated winter losses of managed honey bee colonies are a major concern, but the underlying mechanisms remain controversial. Among suspects are the parasitic mite Varroa destructor, the microsporidian Nosema ceranae and associated viruses. Here, we hypothesize that pathogens reduce the life expecta...

  8. Chronology. Classroom Focus.

    Science.gov (United States)

    McGoldrick, Neale

    1995-01-01

    Presents a chronology of important dates and events in the struggle for women's rights and women's suffrage. Begins in 1648 with the first call for women's suffrage in Maryland and concludes in 1920 with the passage of the 19th Amendment by Tennessee. (CFR)

  9. Estimation of life-span of instrumentation and control cables used in nuclear power plants using the tensile testing methodology

    International Nuclear Information System (INIS)

    Nuclear Power Plants (NPPs) contain myriads of electrical cables of all sizes, voltage ratings and lengths delivering electrical power to much vital, as well as non-vital equipment. These cables are insulated with some form of polymeric insulation. These insulating materials will gradually age from exposure to heat, radiation, moisture and chemicals. Hence, on-site testing of the conditions of these cables is necessary to ensure their continued reliability in service and to predict their remaining life. In addition these cables must operate reliably in the harsh steam environments produced by postulated design-basis events (e.g. LOCA). Conservatively, this event is assumed to occur at the end of the planned service life of the NPPs. Evidence must be provided prior to their installation that the affected cables can meet the specified functional requirements. Usually this evidence is provided by the results of the qualification tests, simulating operational aging, the LOCA and the post accident phase. Research efforts are continuing, through out the world, for developing effective testing methods which can assess the present condition of a cable's electrical property and can also predict the remaining life and LOCA survivability with some assurance. It has been found that the insulation resistance of cables are not much affected by ageing. Experience has shown that the failure of nuclear cables is primarily due to the hardening and embrittlement of the insulation resulting in the formation of micro cracks, a loss of dielectric strength and high leakage currents. The elongation at break measurements carried on various cables subjected to accelerated thermal ageing were used to arrive at Arrhenius parameters based on an acceptable 65% elongation at break criteria. Life estimation have been carried at operating temperatures using these parameters. (author)

  10. Life-span shortening and disease incidence in male BALB/c and C57BL mice after single, fractionated d(50)-Be neutron or gamma exposure

    International Nuclear Information System (INIS)

    Life-span shortening and causes of death, ascertained by autopsy and histological examination at the time of spontaneous death, after single or fractionated x-ray, gamma, or d(50)-Be neutron irradiation, are being studied for two mouse strains (BALB/c and C57BL) with different disease characteristics. Fractionation schedules that have been implemented are x rays, four weekly exposures (C57BL); gamma rays, 10 daily exposures (BALB/c; and neutrons, eight exposures at 3-h intervals (C57BL). The data are incomplete but suggest that the dependency of life shortening on dose is related to the types of effects induced by radiation and results in different functions, linear or sigmoid, for the two mouse strains. Fractionated gamma irradiation causes more tumors than single exposure, but, generally, this is a result of multiple tumors occurring in animals. The relative biological effectiveness (RBE) for life shortening for d(50)-Be neutrons as compared to gamma rays is on the order of 1 to 2 and is slightly greater for the C57BL than for the BALB/c strain. 18 refs., 2 figs., 3 tabs

  11. 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.

  12. Chronological History of Federal Fleet Actions and Mandates (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-01

    This chronological history of Federal fleet actions and mandates provides a year-by-year timeline of the acts, amendments, executive orders, and other regulations that affect Federal fleets. The fleet actions and mandates included in the timeline span from 1988 to 2009.

  13. Late effects of selected immunosuppressants on immunocompetence, disease incidence, and mean life-span. II. Cell-mediated immune activity. [Mice, X radiation

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, W.J.; Perkins, E.H.; Goodman, S.A.; Hori, Y.; Halsall, M.K.; Makinodan, T.

    1975-01-01

    The late effects of various immunosuppressive insults on cell-mediated immunity in mice were studied in an attempt to assess the role of immune surveillance in the aging process. Results were obtained using susceptibility to allogeneic tumor cell challenge, graft-versus-host reaction (GVHR), blastogenic response to PHA, a thymus derived T cell-specific plant mitogen, and cytolytic activity against allogeneic tumor cells as measures of immunologic activity. In vivo studies late in life show that resistance to allogeneic tumor cells is significantly decreased in thymectomized mice, whereas those treated with cortisone, cyclophosphamide and sublethal x-ray remain unchanged. Spleen cells from only the thymectomized and the sublethally irradiated mice show reduced activity in the GVHR. No difference is seen in the activity of bone marrow cells. Results consistent with these findings were obtained in in vitro studies. Thus spleen cells from thymectomized or sublethally irradiated mice show decreased activity in response to PHA, whereas no change is seen in spleen cells from other treated groups. Hence, surgical and physical insults are more likely to induce long-lasting immunosuppression in those immunocompetent tissues whose activity normally diminishes with advancing age. Furthermore, the degree of immunosuppression seen in this study is not of the order of magnitude that one could reasonably predict a significant decrease in mean life-span.

  14. Real Wage Chronology

    OpenAIRE

    Amy Peng; Louis N. Christofides

    2009-01-01

    We process information in a large number of Canadian wage contracts, signed over a period of several decades, to generate the long-run history of the real wage for each bargaining pair. We term these hitherto unexamined histories ‘chronologies’. We are able to generate 1574 continuous real wage chronologies and we examine the evolution of the real wage in each case. We explore the influence of productivity growth, the labour relations record of the pair, the influence of industry and region a...

  15. Intelligence across the life span

    OpenAIRE

    Whitaker, Simon

    2015-01-01

    Purpose The aim of this paper is to present a theoretical explanation as to why young people score higher on IQ tests than their parents would have done at the same age. Background It is now well established that IQ tests score higher as they get older by about .3 of an IQ point per year for each year since they were standardized. So if the average 20 year old in 1972 was given an IQ test standardized in 2015 they would get a measured IQ of about 87, whereas the average 20 year o...

  16. 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.

  17. 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.

  18. 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. PMID:21230706

  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. 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.

  1. Research of improving lead-acid storage battery life-span%提高铅酸蓄电池寿命方法的研究

    Institute of Scientific and Technical Information of China (English)

    成建生

    2011-01-01

    首次提出在铅酸蓄电池内部加装可控点燃装置的方法,来提高铅酸蓄电池的循环寿命.原理是采用三段大电流脉冲过充电提高铅酸蓄电池组充电电压,加大充电电流,可控点燃装置点燃充电过程中产生的氢气和氧气,提高氢、氧的复合率.通过对同类型铅酸蓄电池内部的压力测量,不同工作模式时容量衰减比对,对铅酸蓄电池的循环寿命进行了研究.研究表明:铅酸蓄电池内部的气体压力减小,循环寿命比同类铅酸蓄电池提高1.5~2倍,深循环寿命可达600次.%The way of adding a controlled firing device inside the lead-acid storage battery was brought forward firstly to enhance the cycle life-span of leard-acid storage battery in this paper. The charging volt of the lead-acid storage battery group and the charging current could be improved by the way of three sections heavy current pulse over-charging. The controlled firing device fired the hydrogen and oxygen produced in the charging process to improve the hydrogen and oxygen recombination rate. By measuring the internal pressure of different types of lead acid batteries, and comparing the capacity attenuation in different working modes, the life of lead acid batteries were researched. The results show that the internal pressure of the battery is reduced, the life is extended by 1.5 - 2 times comparing with the similar types of batteries, and the deep cycle life can reach 600 times.

  2. 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.

  3. JNIH-ABCC life span study of children born to atomic bomb survivors. Report 1. Influence of concomitant variables upon mortality rate comparison

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Hiroo; Ueda, Shoichi

    1963-04-18

    The study of mortality rates among children born to atomic bomb survivors is being conducted according to the protocol, and at present, data for those whose parents are included in the Life Span Study sample are ready for analysis. Using this portion, the influence of various concomitant factors on the infant mortality rate was investigated. The distribution of year of birth, maternal age, and birth order differs between comparison groups. The differences introduce fairly large biases into mortality rate comparisons. For example, the infant mortality rate in children, both of whose parents were atomic bomb survivors would be overestimated by 10% or more. As far as such concomitant factors are observable, the bias can be reduced to negligible magnitude. Other factors are equally important but difficult to observe. For example, environmental factors influence mortality a great deal but adequate methods for treating such factors have not yet been found. If such bias is not eliminated, conclusions to be derived from this study suffer serious limitation, namely, unless drastic radiation effects exist, neither existence nor absence of radiation effects will be demonstrable. Investigation is continuing, especially concerning: how to measure environmental factors; regression analysis on radiation dose or distance from the hypocenter; and examination of specific causes of death. 7 references, 4 figures, 9 tables.

  4. 浅谈长寿命技术电度表用磁力轴承%Elementary introduction to magnetic repulsion force bearing used for long life-span type watt-hour meter

    Institute of Scientific and Technical Information of China (English)

    郭凯新; 冯超; 张瑛; 王伟钦; 李显明

    2001-01-01

    对长寿命电度表用磁力轴承的发展、现状和使用寿命等方面做了探讨。%This paper mainly discusses the development,the present situation and life span of the magnetic type watt-hour meter.

  5. Span of Control and Span of Activity

    OpenAIRE

    Oriana Bandiera; Andrea Prat; Raffaella Sadun; Julie Wulf

    2012-01-01

    For both practitioners and researchers, span of control plays an important role in defining and understanding the role of the CEO. In this paper, we combine organizational chart information for a sample of 65 companies with detailed data on how their CEOs allocate their work time, which we define as their span of activity. Span of activity provides a direct measure of the CEO's management style, including the attention devoted to specific subordinates and functions, the time devoted to indivi...

  6. Chronological objects in demographic research

    Directory of Open Access Journals (Sweden)

    Frans J. Willekens

    2013-03-01

    Full Text Available BACKGROUND Calendar time, age and duration are chronological objects. They represent an instant or a time period. Age and duration are usually expressed in units with varying lengths. The number of days in a month or a year depends on the position on the calendar. The units are also not homogeneous and the structure influences measurement. One solution, common in demography, is to use units that are large enough for the results not to be seriously affected by differences in length and structure. Another approach is to take the idiosyncrasy of calendars into account and to work directly with calendar dates. The technology that enables logical and arithmetic operations on dates is available. OBJECTIVE To illustrate logical and arithmetic operations on dates and conversions between time measurements. METHODS Software packages include utilities to process dates. I use existing and a few new utilities in R to illustrate operations on dates and conversions between calendar dates and elapsed time since a reference moment or a reference event. Three demographic applications are presented. The first is the impact of preferences for dates and days on demographic indicators. The second is event history analysis with time-varying covariates. The third is microsimulation of life histories in continuous time. CONCLUSIONS The technology exists to perform operations directly on dates, enabling more precise calculations of duration and elapsed time in demographic analysis. It eliminates the need for (a approximations and (b transformations of dates, such as Century Month Code, that are convenient for computing durations but are a barrier to interpretation. Operations on dates, such as the computation of age, should consider time units of varying length.

  7. 闵尔昌《江子屏先生年谱》校点二种正误%Correction to the Emendations and Punctuations of a Chronological Life of Mr. Jiang Ting by Min Erchang

    Institute of Scientific and Technical Information of China (English)

    高明峰

    2012-01-01

    A Chronological Life of Mr. Jiang Ziping by 1VAn Erchang is important in the study of Jiang Fan and even the academy in Qing dynasty, which has been collated by Qi Yongxiang, and also by Zheng Xiaoxia and Wu Ping. Qi's revision has 29 errors, including 14 word-missings, 6 abundant words, 8 word faults, 1 inverted mistake, as well as 8 punctuation errors, including 5 period and comma mistakes and 3 wrong marks. The version by Zheng X aoxia and Wu Ping have the following two problems: the wrong note format and punctuation errors.%闵尔昌《江子屏先生年谱》是研究江藩乃至清代学术的重要资料。漆永祥和郑晓霞、吴平分别对其进行了校点整理。漆永祥校点本存在文字错误共有29处,含脱误14处,衍误6处,讹误8处,倒误1处。另有标点错误8处,含句逗不当5处,专名线标示不当3处。郑晓霞、吴平标点本存在闵尔昌《江子屏先生年谱》注文标识不当以及标点失误两大问题。

  8. Built environment, health and how old you are: A view across the life span - 20th Annual John K. Friesen Conference - Growing Old in a Changing Climate: Exploring the Interface Between Population Aging and Global Warming (2011)

    OpenAIRE

    Frank, Larry

    2011-01-01

    This video clip comprises the four presentations of Panel Session 4, “Preparing Aging Populations for Climate Change in British Columbia and Beyond” held at the 20th Annual John K. Friesen Conference, "Growing Old in a Changing Climate: Exploring the Interface Between Population Aging and Global Warming," MAY 25-26, 2011, Vancouver, BC. Dr. Larry Frank "Built environment, health and how old you are: A view across the life span" - Talk focuses upon the relationships between the designs of the ...

  9. Study of Life-Span Prediction for Oil and Gas Piping Containing Corrosion Defects%含腐蚀缺陷管道剩余寿命预测方法研究

    Institute of Scientific and Technical Information of China (English)

    高启荣; 淡勇

    2013-01-01

    以天然气加热炉管为研究对象,针对含缺陷管道剩余寿命预测问题,分别基于ASME-B31G 准则和有限元分析、优化设计理论,建立了计算含腐蚀缺陷管道剩余寿命的方法,根据天然气加热炉管的检测数据,应用建立的两种计算方法对天然气加热炉管剩余寿命进行了预测计算,并对两种剩余寿命预测方法、预测结果进行了讨论分析.%To predicate the residual life-span of heater tubes in natural gas recovery plant, two methods to calculate residual life-span for piping containing corrosion defects were established based on ASME-B31G code and FEM optimum design, according to the corrosion state and the inspecting results of the heater tube, the residual life-span of heater tubes were calculated with the methods. Finely, compare analysis and discussions of two methods were made.

  10. Uniform random spanning trees

    OpenAIRE

    Pemantle, Robin

    2004-01-01

    There are several good reasons you might want to read about uniform spanning trees, one being that spanning trees are useful combinatorial objects. Not only are they fundamental in algebraic graph theory and combinatorial geometry, but they predate both of these subjects, having been used by Kirchoff in the study of resistor networks. This article addresses the question about spanning trees most natural to anyone in probability theory, namely what does a typical spanning tree look like?

  11. Chronological objects in demographic research

    NARCIS (Netherlands)

    Willekens, F.J.C.

    2013-01-01

    Background: Calendar time, age and duration are chronological objects. They represent an instant or a time period. Age and duration are usually expressed in units with varying lengths. The number of days in a month or a year depends on the position on the calendar. The units are also not homogeneous

  12. The boundary of the chronology violating set

    CERN Document Server

    Minguzzi, E

    2016-01-01

    A sufficiently general definition for the future and past boundaries of the chronology violating region is given. In comparison to previous studies, this work does not assume that the complement of the chronology violating set is globally hyperbolic. The boundary of the chronology violating set is studied and several propositions are obtained which confirm the reasonability of the definition. Some singularity theorems related to chronology violation are considered.

  13. CHRONOLOGICAL INVENTORY OF CHEMISTRY TEACHING

    OpenAIRE

    Laxman S. Bhattar; SWAMINATH L.BHATTAR

    2013-01-01

    The Chronological Research of Chemistry teaching in the science education isinvented by the following pioneer philosophers and they developed the skills abilitieswhich is remarked by the Greek philosophers are socrates and plato (in 116 to 127 BC)given an idea an naturalistic and conceptual thoughts and highlights on water. Chinaphilosophers (365 to 427 BC) Taoism made pioneer of Alchemy used in medicines andtranslation preparation of Au (Gold). Epicurea (341 to 371 to 400 BC) developed kinet...

  14. 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

  15. 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.

  16. The influence of superoxide dimutase and some other radical scavengers on X-ray resistance, life span and membrane integrity of Sacharomyces cerevisiae. Einfluss der Superoxiddismutase und anderer Radikalfaenger auf Roentgenstrahlenresistenz, Lebensspanne und Membranintegritaet von Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, V.

    1988-07-09

    Evaluations of various strains of yeast showed these to differ widely in the activities of superoxide dimutase and catalase, X-ray sensitivity, reproductive capacity and malondialdehyde concentration. Higher SOD activities in reponse to increases in oxygen production under extreme physiological conditions were observed for the cells of a haploid strain and just as well seen in those of a diploid strain. There were findings pointing to mutually 'compensatory' effects in respect of the contents of CAT and thiol. When intracellular radical scavengers were 'overstrained' by exposure to high X-ray doses, untoward effects on membrane integrity could be detected after irradiation. The use of the SOD-specific inhibitor DDC led to a reduction of both X-ray resistance and life span as a result of SOD-inhibition. Exogenous SOD was seen to reduce the mean life span. Cu{sup 2+} and Mn{sup 2+} were found to have a dual action in that they not only increased the resistance to X-rays through an augmentation of SOD activity but also had an immediate beneficial effect on radioresistance. Exogenous H202 led to an increase in the cellular CAT contents and an enhancement of X-ray resistance. (orig./MG).

  17. Communicating Employability Enhancement throughout the Life-Span: A National Intervention Program Aimed at Combating Age-Related Stereotypes at the Workplace

    Science.gov (United States)

    van Selm, Martine; Van der Heijden, Beatrice 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. We will discuss key obstacles for improving…

  18. 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

  19. 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

  20. 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

    OpenAIRE

    Claudia Regina Baptista Haddad; Damiani Pereira Lemos; Paulo Mazzafera

    2004-01-01

    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, chlor...

  1. Late effects of selected immunosuppressants on immunocompetence, disease incidence, and mean life-span. I. Humoral immune activity. [Mice, x radiation

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, E.H.; Peterson, W.J.; Gottlier, C.F.; Halsall, M.K.; Caccheiro, L.H.; Makinodan, T.

    1975-01-01

    The effect of different immunosuppressive treatments during young adulthood on humoral immune competence late in life was determined. It was found that the marked reduction in humoral immune competence in aged mice is further compromised when severe insults are administered early in life. Thus, thymectomy, splenectomy, and sublethal x-irradiation produced lasting immunodepression as measured in situ and by the hemolysin, direct and indirect plaque forming cells responses of adoptively transferred spleen cells. In contrast, treatment with cyclophosphamide and cortisone acetate were without effect, indicating that drug-damaged cells of the immune system were replaced by competent cells during the course of time. Decrease in immune competence of aged thymectomized animals could not be correlated with a decrease in numbers of theta-bearing T or immunoglobulin receptor-bearing B lymphocytes. The significance of the observed unequal effects of these immunosuppressants on immune competence, as they relate to disease incidence and life expectancy, are dealt with in the third paper in this series.

  2. Chronology of eclipse "San Miao"

    Science.gov (United States)

    Liu, Ci-Yuan

    2001-06-01

    The ancient book "Mozi" (5th century BC) records: "In ancient times, the San Miao tribes were in disarray. The sun rose in the evening...King Yu vanquished them. "King Yu is a prehistoric person living in 23-19th century BC. The strange phenomena "sun rose in evening" was explained as a large solar eclipse at sunset by Pang. Therefore investigations on it may lead to an important progress of Chinese chronology. After an analysis on all similar records in Chinese history, we pay main attention to the relationship of eclipse computations with parameter "c", the long term of earth's rotation rate. We have computed all the solar eclipses in that period by the way similar to that used for investigating the "double dawn" eclipse. By change parameter "c" in reasonable range (28-36 sec/cy2), we have found 11 possible results listed in a table. One figure shows the eclipse maps and relative "double dawn/dusk" areas while another one illustrates how the parameter "c" affects the result. For an exact conclusion of King Yu's chronology, we need further progress from both side: history which may limit the King Yu's period and astronomy which may limit the possible range of parameter "c".

  3. '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.

  4. The life-span of experimental animals and their progeny under influence of the ecological conditions in the Chernobyl zone of alienation

    International Nuclear Information System (INIS)

    Laboratory three-month old animals (white mongrel rats F0) were delivered to Chernobyl. The control animals were kept in a Kyiv vivarium. The indices of lifespan and dynamics of mortality of rats and their progeny have been determined using the life table methodology. The results have shown no essential difference in the indices of mortality and lifespan between control and experimental animals of the F0 generation. The expected lifespan of irradiated rats of the F1 - F2 generations increased in the age interval of 300 - 600 days. It's necessary to note that a decrease of this index in the Chernobyl groups of the F3 - F6 generations has been observed

  5. 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.

  6. 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

  7. Astronomical arguments in Newton's Chronology

    CERN Document Server

    Naze, Yael

    2012-01-01

    In his Chronology, Newton uses astronomical "evidence" to support its extreme rejuvenation of ancient times. These elements, having a scientific varnish, provide some credibility to the work. They have been fiercely debated for a century, with a gradual undermining of Newton's assumptions. However, this has not dented the prestige of the English scientist. ----- Dans sa Chronologie, Newton utilise des "preuves" astronomiques pour appuyer son rajeunissement extreme des epoques anciennes. Ces elements, au vernis scientifique, donnent une credibilite certaine a l'ensemble. Ils ont donc ete aprement discutes, les debats sapant petit a petit les hypotheses du savant anglais pour finalement porter un coup mortel a l'ensemble. Cela n'a toutefois pas entame le prestige du savant anglais.

  8. Compatible spanning trees

    OpenAIRE

    Garcia Olaverri, Alfredo Martin; Huemer, Clemens; Hurtado Díaz, Fernando Alfredo; Tejel Altarriba, Francisco Javier

    2014-01-01

    Two plane geometric graphs are said to be compatible when their union is a plane geometric graph. Let S be a set of n points in the Euclidean plane in general position and let T be any given plane geometric spanning tree of S. In this work, we study the problem of finding a second plane geometric tree T' spanning S, such that is compatible with T and shares the minimum number of edges with T. We prove that there is always a compatible plane geometric tree T' having at most #n - 3#/4 edges in ...

  9. 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.

  10. 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

    International Nuclear Information System (INIS)

    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

  11. Climate wavelet spectrum estimation under chronology uncertainties

    Science.gov (United States)

    Lenoir, G.; Crucifix, M.

    2012-04-01

    Several approaches to estimate the chronology of palaeoclimate records exist in the literature: simple interpolation between the tie points, orbital tuning, alignment on other data... These techniques generate a single estimate of the chronology. More recently, statistical generators of chronologies have appeared (e.g. OXCAL, BCHRON) allowing the construction of thousands of chronologies given the tie points and their uncertainties. These techniques are based on advanced statistical methods. They allow one to take into account the uncertainty of the timing of each climatic event recorded into the core. On the other hand, when interpreting the data, scientists often rely on time series analysis, and especially on spectral analysis. Given that paleo-data are composed of a large spectrum of frequencies, are non-stationary and are highly noisy, the continuous wavelet transform turns out to be a suitable tool to analyse them. The wavelet periodogram, in particular, is helpful to interpret visually the time-frequency behaviour of the data. Here, we combine statistical methods to generate chronologies with the power of continuous wavelet transform. Some interesting applications then come up: comparison of time-frequency patterns between two proxies (extracted from different cores), between a proxy and a statistical dynamical model, and statistical estimation of phase-lag between two filtered signals. All these applications consider explicitly the uncertainty in the chronology. The poster presents mathematical developments on the wavelet spectrum estimation under chronology uncertainties as well as some applications to Quaternary data based on marine and ice cores.

  12. 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 Europ...

  13. 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

  14. Life span study report 11, part 1

    International Nuclear Information System (INIS)

    In 75,991 A-bomb survivors, shielded kerma and organ doses were calculated based on the new dosimetry system 1986 (DS86) and the previous tentative 1965 dose revised (T65DR) to compare risk coefficients for site-specific cancer mortality during the period 1950 - 1985. As for shielded kerma, the excess relative risk over the various sites and the excess numbers of cancer deaths per 104 person-year-gray were 1.35 - 1.51 and 1.38 - 1.61 times higher, respectively, under the DS86 than under the T65DR. The attributable risks did not differ in the two dosimetric systems. The risk coefficients based on the DS86 organ-absorbed doses were generally smaller than those based on the T65DR values. The difference in cancer mortality between Hiroshima and Nagasaki was smaller with the DS86 than with the T65DR; however, this was not statistically significant for either shielded kerma and organ-absorbed dose. (Namekawa, K.)

  15. Understanding Aggressive Behavior Across the Life Span

    OpenAIRE

    Liu, Jianghong; Lewis, Gary; Evans, Lois

    2012-01-01

    Aggressive behavior is the observable manifestation of aggression and is often associated with developmental transitions and a range of medical and psychiatric diagnoses across the lifespan. As healthcare professionals involved in the medical and psychosocial care of patients from birth through death, nurses frequently encounter—and may serve as—both victims and perpetrators of aggressive behavior in the workplace. While the nursing literature has continually reported research on prevention a...

  16. 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…

  17. Life span study report 10 - 1

    International Nuclear Information System (INIS)

    The present study extends the previous report on cancer mortality among atomic bomb survivors by adding data from four additional years of follow-up (1979 - 82) and by expanding the cohort (now designated LSS-E85) to include 11,393 Nagasaki survivors located between 2,500 - 9,999 m from the hypocenter at the time of the bombing (ATB). Significant dose responses were observed for leukemia, for cancers of the lung, female breast, stomach, colon, esophagus, and urinary bladder, and for multiple myeloma. Four new categories of cancer were also investigated: the results for cancers of the liver and intrahepatic bile ducts and of the ovary and other uterine adnexa were suggestive of significant radiation effects, but the positive dose responses for cancers of the gallbladder and prostate were not significant. Due to diagnostic difficulties and the lack of evidence for radiogenic effects at these sites, the results for liver and ovarian cancers do not provide convincing evidence for radiogenic effects. With the exception of multiple myeloma, the relative risk (RR) of radiation-induced cancer mortality was greater for women than for men, for each nonleukemic cancer with a significant overall dose response. These differences can be attributed in large measure to differences in the background cancer mortality rates, which are generally much higher for men than women. For leukemia there was no significant sex difference in the RR, while for multiple myeloma women had a slightly, though nonsignificantly, lower RR than males. A statistically significant interaction (p = .008) between the effects of age ATB and attained age on radiation-related mortality was also observed for cancers other than leukemia. In particular, the initially large RRs seen in those who were young ATB have decreased with time, while the smaller RRs for those who were older ATB tended to increase. (author)

  18. Enhancing cognitive function across the life span.

    Science.gov (United States)

    Korol, Donna L

    2002-04-01

    Glucose administration regulates many neural and behavioral processes in rodents, including learning and memory. Given the important role of glucose in brain function and the safety of glucose as a treatment, we have investigated the effects of glucose administration in humans of different ages. In previous work, we examined the effects of early-morning glucose consumption on cognitive functions in elderly individuals. In this population, glucose enhanced performance on specific measures, particularly on those tasks where mild age-related deficits appear (e.g., verbal declarative memory). Interestingly, glucose failed to enhance cognitive functions in young adults. Our recent work has examined three issues related to glucose enhancement of cognition: First, is glucose effective only in reversing impairments or can it also facilitate performance in highly functioning individuals? Second, are glucose effects dependent either on time of day or on interactions with other meals? Third, are typical breakfast foods as effective as glucose in enhancing cognitive performance? Our findings suggest that glucose can improve memory in highly functioning populations as it does in populations with deficits. However, enhancement by glucose may require sufficient levels of task difficulty and of blood glucose. In addition, like glucose, early morning consumption of cereal can improve performance on some cognitive tests. These results have important implications for the nature of glucose facilitation of memory and for the role of dietary factors in performance of many daily activities. PMID:11976194

  19. Extravehicular Activity Fact Sheet: An EVA Chronology

    Data.gov (United States)

    National Aeronautics and Space Administration — Walking to Olympus: An EVA Chronology chronicles the 154 EVAs conducted from March 1965 to April 1997. It is intended to make clear the crucial role played by EVA...

  20. Mars chronology: assessing techniques for quantifying surficial processes

    Science.gov (United States)

    Doran, Peter T.; Clifford, Stephen M.; Forman, Steven L.; Nyquist, Larry; Papanastassiou, Dimitri A.; Stewart, Brian W.; Sturchio, Neil C.; Swindle, Timothy D.; Cerling, Thure; Kargel, Jeff

    2004-01-01

    Currently, the absolute chronology of Martian rocks, deposits and events is based mainly on crater counting and remains highly imprecise with epoch boundary uncertainties in excess of 2 billion years. Answers to key questions concerning the comparative origin and evolution of Mars and Earth will not be forthcoming without a rigid Martian chronology, enabling the construction of a time scale comparable to Earth's. Priorities for exploration include calibration of the cratering rate, dating major volcanic and fluvial events and establishing chronology of the polar layered deposits. If extinct andor extant life is discovered, the chronology of the biosphere will be of paramount importance. Many radiometric and cosmogenic techniques applicable on Earth and the Moon will apply to Mars after certain baselines (e.g. composition of the atmosphere, trace species, chemical and physical characteristics of Martian dust) are established. The high radiation regime may pose a problem for dosimetry-based techniques (e.g. luminescence). The unique isotopic composition of nitrogen in the Martian atmosphere may permit a Mars-specific chronometer for tracing the time-evolution of the atmosphere and of lithic phases with trapped atmospheric gases. Other Mars-specific chronometers include measurement of gas fluxes and accumulation of platinum group elements (PGE) in the regolith. Putting collected samples into geologic context is deemed essential, as is using multiple techniques on multiple samples. If in situ measurements are restricted to a single technique it must be shown to give consistent results on multiple samples, but in all cases, using two or more techniques (e.g. on the same lander) will reduce error. While there is no question that returned samples will yield the best ages, in situ techniques have the potential to be flown on multiple missions providing a larger data set and broader context in which to place the more accurate dates.

  1. A report from the 2013 international symposium: the evaluation of the effects of low-dose radiation exposure in the life span study of atomic bomb survivors and other similar studies.

    Science.gov (United States)

    Grant, E J; Ozasa, K; Ban, N; de González, A Berrington; Cologne, J; Cullings, H M; Doi, K; Furukawa, K; Imaoka, T; Kodama, K; Nakamura, N; Niwa, O; Preston, D L; Rajaraman, P; Sadakane, A; Saigusa, S; Sakata, R; Sobue, T; Sugiyama, H; Ullrich, R; Wakeford, R; Yasumura, S; Milder, C M; Shore, R E

    2015-05-01

    The RERF International Low-Dose Symposium was held on 5-6 December 2013 at the RERF campus in Hiroshima, Japan, to discuss the issues facing the Life Span Study (LSS) and other low-dose studies. Topics included the current status of low-dose risk detection, strategies for low-dose epidemiological and statistical research, methods to improve communication between epidemiologists and biologists, and the current status of radiological studies and tools. Key points made by the participants included the necessity of pooling materials over multiple studies to gain greater insight where data from single studies are insufficient; generating models that reflect epidemiological, statistical, and biological principles simultaneously; understanding confounders and effect modifiers in the current data; and taking into consideration less studied factors such as the impact of dose rate. It is the hope of all participants that this symposium be used as a trigger for further studies, especially those using pooled data, in order to reach a greater understanding of the health effects of low-dose radiation. PMID:25811153

  2. Spanning paths in hypercubes

    OpenAIRE

    Dvořák, Tomáš; Gregor, Petr; Koubek, Václav

    2005-01-01

    Given a family \\u_i,v_i\\_i=1^k of pairwise distinct vertices of the n-dimensional hypercube Q_n such that the distance of u_i and v_i is odd and k≤n-1, there exists a family \\P_i\\_i=1^k of paths such that u_i and v_i are the endvertices of P_i and \\V(P_i)\\_i=1^k partitions V(Q_n). This holds for any n≥2 with one exception in the case when n=k+1=4. On the other hand, for any n≥3 there exist n pairs of vertices satisfying the above condition for which such a family of spanning paths does not ex...

  3. Towards an absolute chronology for the Aegean iron age: new radiocarbon dates from Lefkandi, Kalapodi and Corinth.

    Directory of Open Access Journals (Sweden)

    Michael B Toffolo

    Full Text Available The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8(th century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11(th century BCE according to the Conventional Aegean Chronology and in the late 12(th century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11(th century BCE.

  4. Towards an absolute chronology for the Aegean iron age: new radiocarbon dates from Lefkandi, Kalapodi and Corinth.

    Science.gov (United States)

    Toffolo, Michael B; Fantalkin, Alexander; Lemos, Irene S; Felsch, Rainer C S; Niemeier, Wolf-Dietrich; Sanders, Guy D R; Finkelstein, Israel; Boaretto, Elisabetta

    2013-01-01

    The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8(th) century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11(th) century BCE according to the Conventional Aegean Chronology and in the late 12(th) century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11(th) century BCE. PMID:24386150

  5. On the Astronomical Records and Babylonian Chronology

    CERN Document Server

    Gurzadyan, V G

    2000-01-01

    We outline the priority of high quality data of astronomical content as our strategy for the analysis of the ancient astronomical records in the search of the absolute chronology of the Near East in II millennium BC. The correspondingly defined set of data for two lunar eclipses of EAE 20 and 21 tablets linked to Ur III period enables us the choice of eclipses of 27 June 1954 BC and 17 March 1912 BC; here the information on the exit position of the darkening of the lunar disk acts as a crucial informator survived in the records. We then discuss why the 56/64 year Venus cycle cannot be traced in the Venus Tablet and therefore cannot serve as an anchor for the search of chronologies. The month length method is discussed as well. In sum the available data support the Ultra-Low Chronology proposed in the book by H.Gasche, J.A.Armstrong, S.W.Cole and V.G.Gurzadyan, "Dating the Fall of Babylon" (1998) and, particularly, leave no astronomical background for the High Chronology. Ultra-Low Chronology is supported also...

  6. 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

  7. Aging in elderly: Chronological versus photoaging

    Directory of Open Access Journals (Sweden)

    Priya Cinna Durai

    2012-01-01

    Full Text Available Background: Skin is a window to aging changes, a biological reality. There is a dearth of studies regarding the various chronological (intrinsic aging and photoaging (extrinsic changes seen in Asians. This study was undertaken to detect the clinical pattern of aging skin changes and dermatoses seen in the elderly. Materials and Methods: This was a descriptive study conducted on 500 consecutive elderly individuals attending the Dermatology out-patient department. The severity of photoaging was graded using Glogau scale. Results: Most of the population had skin type IV and V. Majority (415, 83% of our cases had chronological aging without photoaging and the remaining 85 (17% individuals had photoaging along with chronological aging. The common skin changes due to chronological aging were thin skin, fine wrinkles, xerosis, and loss of elasticity. Photoaging changes such as dyspigmentation, freckles, thick skin, deep wrinkles, melasma, citrine skin, senile purpura, pseudostellate scar, acrokeratoelastoidosis marginalis, and lentigines were less frequent in our study. Smoking and prolonged sun exposure was the risk factors aggravating photoaging. The most common dermatosis was pruritus in 248 (49.6% individuals, of which 149 (29.8% had pruritus associated with xerosis. Contact dermatitis was more common in males. Fungal infections were frequently seen in females. Seborrhoeic keratosis (253, 50.6% was the most common benign neoplasm more commonly seen in males. Cutaneous malignancies were less common in our study population. Conclusion: Photoaging changes were less common than chronological aging changes in skin type IV. Chronological changes were more frequent in females than males, while photoaging was more frequent in males.

  8. Tracking bacterial growth in liquid media and a new bacterial life model

    Institute of Scientific and Technical Information of China (English)

    刘实

    1999-01-01

    By increasing viscosity of liquid media above 8.4 centipoise (cp) i.e. 0.084 g·cm-1·S-1 individual growth and family formation of Escherichia coli was continuously observed in real-time for up to 6 h. The observations showed primarily unidirectional growth and reproduction of E. coli and suggested more than one reproduction in the observed portion of E. coli life span. A new bacterial life model is proposed: each bacterium has a stable cell polarity that ultimately transforms into two bacteria of different generations; the life cycle of a bacterium can contain more than one reproduction cycle; and the age of a bacterium should be defined by its experienced chronological time. This new bacterial life model differs from the dominant concepts of bacterial life but complies with all basic life principles based on direct observation of macroorganisms.

  9. Chronology violation and the Cosmological Argument

    CERN Document Server

    Romero, G E

    2003-01-01

    The Kalam Cosmological Argument is perhaps the most solid and widly discussed argument for a caused creation of the universe. The usual objections to the argument mainly focus on the second premise. In this paper we discuss the dependency of the first premise on the topological structure of the space-time manifold adopted for the underlying cosmological model. It is shown that in chronology-violating space-times the first premise is also violated. The chronology-violation, in turn, requires a massive violation of the so-called energy conditions which could have observational effects that are briefly discussed here. Hence, astronomical observations could be relevant for the validity of the metaphysical argument. In this sense, it is possible to talk of "observational theology".

  10. Counting spanning trees in graphs

    OpenAIRE

    Azarija, Jernej

    2012-01-01

    The history of counting the number of spanning trees dates back into the year 1842 in which the German mathematician Gustav Kirchhoff derived a relation between the number of spanning trees of a graph G (τ(G)) and the determinant of a specific submatrix associated with G. After this result many other related results followed. For example in 1889 the British mathematician A. Cayley showed that the complete graph on n nodes has nn−2 spanning trees.The function τ can nowadays be found in the fi...

  11. A chronology of librarianship, 1960-2000

    CERN Document Server

    Wilhite, Jeffrey M

    2009-01-01

    This book covers all areas of library literature that inform the history of librarianship and ranges over multiple continents. Its broad scope lends itself to wide use by scholars and students of library history and library literature. The chronology is presented in a dictionary format and separated into decades. It is complemented by a comprehensive bibliography and both subject and name indexes, which are cross-listed for ease of use.

  12. Spatial variability in growth-increment chronologies of long-lived freshwater mussels: Implications for climate impacts and reconstructions

    Science.gov (United States)

    Black, Bryan A.; Dunham, Jason B.; Blundon, Brett W.; Raggon, Mark F.; Zima, Daniela

    2010-01-01

    Estimates of historical variability in river ecosystems are often lacking, but long-lived freshwater mussels could provide unique opportunities to understand past conditions in these environments. We applied dendrochronology techniques to quantify historical variability in growth-increment widths in valves (shells) of western pearlshell freshwater mussels (Margaritifera falcata). A total of 3 growth-increment chronologies, spanning 19 to 26 y in length, were developed. Growth was highly synchronous among individuals within each site, and to a lesser extent, chronologies were synchronous among sites. All 3 chronologies negatively related to instrumental records of stream discharge, while correlations with measures of water temperature were consistently positive but weaker. A reconstruction of stream discharge was performed using linear regressions based on a mussel growth chronology and the regional Palmer Drought Severity Index (PDSI). Models based on mussel growth and PDSI yielded similar coefficients of prediction (R2Pred) of 0.73 and 0.77, respectively, for predicting out-ofsample observations. From an ecological perspective, we found that mussel chronologies provided a rich source of information for understanding climate impacts. Responses of mussels to changes in climate and stream ecosystems can be very site- and process-specific, underscoring the complex nature of biotic responses to climate change and the need to understand both regional and local processes in projecting climate impacts on freshwater species.

  13. Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia.

    Science.gov (United States)

    Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

    2016-01-01

    We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants' VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition.

  14. 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...

  15. Chronological Records of Li Anzhai and Yu Shiyu

    Institute of Scientific and Technical Information of China (English)

    WANG Hongliang

    2013-01-01

    In the history of Chinese ethnolo-gy, Li Anzhai and Yu Shiyu were not only life partners, but also an important academic married couple, especially in Tibetology.Li Anzhai was not only a representative in frontier research in China , but also a core figure in the West China school of Anthropology .He also has an important position in the history of modern academics . Yu Shiyu had an extremely rich talent for languages , and was good at sorting out bibliographies .Moreo-ver, she was interested in field investigation , which laid a solid foundation for her research on Tibetology .She also provided important support for Li Anzhai’ s fieldwork in Tibetan areas.The cou-ple ’ s academic life blended with each other , and they could be regarded as “two birds with the same destination” ( tianya tongming niao) . The life of this couple can help us understand that their life was both manifested and hidden from view by the times, and their academic life was both created and destroyed by the times .With regard to their academic position and social impact , it was a pity that their academic research did not meet the expectation of academic circles . Within various works related to the review of the history of the dis-ciplines, the couple was always included , in spite of the fact that the introductions to them were al-ways very simple .Although they are mentioned in some sporadic works , most of these works are only introductory articles or book reviews . Up until now, no one has systematically researched their life and academic thought .Hence, the author, by combing through various documents and archives , gives a chronological record of Li Anzhai ’ s and Yu Shiyu ’ s life story and academic achievements in order to provide basic historical data for academ-ic circles to carry out further research on the histo-ry of the discipline .

  16. Lake trout otolith chronologies as multidecadal indicators of high-latitude freshwater ecosystems

    Science.gov (United States)

    Black, B.A.; Von Biela, V.R.; Zimmerman, C.E.; Brown, Randy J.

    2013-01-01

    High-latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments. To address this issue, dendrochronology (tree-ring analysis) techniques were applied to growth-increment widths in otoliths from lake trout (Salvelinus namaycush) from the Chandler Lake system, Alaska (68.23°N, 152.70°W). All otoliths were collected in 1987 and exhibited highly synchronous patterns in growth-increment width. Increments were dated, the widths were measured, and age-related growth declines were removed using standard dendrochronology techniques. The detrended time series were averaged to generate an annually resolved chronology, which continuously spanned 1964–1984. The chronology positively and linearly correlated with August air temperature over the 22-year interval (p < 0.01), indicating that warmer summers were beneficial for growth, perhaps by increasing fish metabolic rate or lake productivity. Given the broad distribution of lake trout within North America, this study suggests that otolith chronologies could be used to examine responses between freshwater ecosystems and environmental variability across a range of temporal and spatial scales.

  17. 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

  18. 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

  19. Criticism of traditional chronology: How long will Scaliger survive?

    Directory of Open Access Journals (Sweden)

    Bukvić Rajko

    2005-01-01

    Full Text Available The paper considers the problems of current state and survival of traditional chronology and history based upon the Scaliger and Petavius books from XVI and XVII centuries. Among many approaches that insist on the need of examination of that chronology, developed at first in Russia, but also in Germany, England, USA and other countries, author focuses to the investigation of Fomenko and his collaborators, but also the Khronotron group. Both these groups, like many others critics of current chronology, as their inspirators and predecessors mark Newton and Morozov, two great scientists who during many decades (! intensively considered problems of examination of chronology and history.

  20. 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...

  1. Perceived Changes in Well-Being: The Role of Chronological Age, Target Age, and Type of Measure

    Science.gov (United States)

    Okun, Morris A.; Dittburner, Julie L.; Huff, Barbara P.

    2006-01-01

    The goal of this study is to investigate whether perceived changes in one's well-being from the present to the future are related to chronological age, target age, and type of measure (psychological well-being versus life satisfaction). Young adults (N = 114) rated their current well-being and their future well-being at one of three target ages…

  2. Chronology of enstatite chondrites and ureilites

    International Nuclear Information System (INIS)

    This paper summarizes the chronological studies on enstatite chondrites and ureilites, both of which are special groups of meteorites with unknown origins. Two unequilibrated enstatite chondrites, Qingzhen and Yamato 6901 (E3), showed the highly disturbed Rb-Sr system, while their silicate fractions yielded the 2.1 Ga isochron. The thermally metamorphosed enstatite chondrite Khairpur (E6) showed the older Rb-Sr age of 4.50 Ga. The parent body of E3 chondrites experienced late thermal event at low temperature, which broke down alkali-bearing sulfides in E3. The observed Rb-Sr data are consistent with the mobilization of Rb from alkali-sulfide to silicate phases. Ureilites show highly depleted trace elements abundance which makes it difficult to determine the age of the formation. The U-Pb and Sm-Nd age determination of low-Ca ureilite Goalpara showed that the Pb and Nd isotopes are heavily contaminated with terrestrial components. The acid residues of high-Ca ureilite MET-78008 were free of contamination and defined the old U-Pb age of 4.563±0.006 Ga. The early formation of ureilites supports their formation through the collisional destruction of the parent body. Including the ureilite date, many evolved meteorites formed within the first 10 million years of the solar system history. Future studies on meteorite chronology with the purpose of understanding the early history of the solar system should focus on the fine time resolution through the precise U-Pb age determination or the relative age determination using the extinct nuclides with half lives less than 10 million years. (author)

  3. Jewish Holocaust Histories and the Work of Chronological Narratives

    Science.gov (United States)

    Silverstein, Jordana

    2012-01-01

    This article examines the ways that, in Holocaust education in Jewish schools in Melbourne and New York at the beginning of the 21st century, knowledge of the Holocaust is transferred to students in chronological form. It begins by asking: What work do chronological narratives do within the Holocaust historical narratives offered within Jewish…

  4. Time and Chronology: Conjoined Twins or Distant Cousins?

    Science.gov (United States)

    Blow, Frances; Lee, Peter; Shemilt, Denis

    2012-01-01

    Weaknesses in pupils' grasp of historical chronology are a commonplace in popular discussion of the state of history education. However, as Blow, Lee and Shemilt argue, although undoubtedly necessary and fundamental, mastery of chronological conventions is not sufficient: the difficulties that pupils experience when learning history are…

  5. SPANNING Between Structure and Nature

    OpenAIRE

    Gao, Yongmei

    2005-01-01

    The design project, a new student union building for the Virginia Tech campus is a 420-foot-long structure spanning from earth to water. Along a steel-glass bridge, three simple volumes play together to achieve the functions of the student union. There is an order among Nature, Architecture, and People in this project. Simple geometric forms and the elegant structure interact with nature to achieve the order. People animate the serenity and become the core of the poetic environment. ...

  6. KeySpan Energy Canada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    Operating in Alberta, KeySpan is a gas processing company with 14 gas plant facilities and pipelines in the province. Since its employees are sometimes working at remote locations, it has been difficult to use conventional classroom and seminar learning techniques to meet training needs. Cost-effective and innovative learning delivery solutions are now available from sophisticated information and communication technologies such as the Internet. In 1998, the Capability Development System (CDS) was developed by KeySpan as an on-line training system. It comprised a software assessment tool, a number of skills profiles for different occupations, and a curriculum registry providing technical information on the gas processing industry. E-learning initiatives are focused on specific projects or business units in order to better manage the training outcomes. The e-learning experience of KeySpan has resulted in benefits such as: better support to its customers and clients' needs through focused training on company-critical processes, services, products, and functions; more efficient employees; and, employees that feel part of the team.

  7. Changes in Anti-Mullerian Hormone (AMH) throughout the Life Span: A Population-Based Study of 1027 Healthy Males from Birth (Cord Blood) to the Age of 69 Years

    DEFF Research Database (Denmark)

    Aksglæde, Lise; Sørensen, K; Boas, M.;

    2010-01-01

    the ontogeny of AMH secretion through life in healthy males. Setting:This was a population-based study of healthy volunteers. Participants: Participants included 1027 healthy males from birth (cord blood) to 69 yr. A subgroup was followed up longitudinally through the infantile minipuberty [(in cord blood...

  8. Chronology of petroleum geophysics; Sekiyu butsuri tansa nenpyo

    Energy Technology Data Exchange (ETDEWEB)

    Kametani, T.

    1996-10-01

    A table, chronology of petroleum geophysics in overseas and in Japan, has been prepared for the convenience of checking events, which are thought to be important as notable affairs in application, success, and technical innovation. In overseas, successes in the 1920s were remarkable, when the US modern geophysical exploration made a start. Successes in determining the position of exploratory drilling by means of the gravity torsion balance, fan shooting seismic refraction method, and seismic reflection method occurred one after another. The USA has kept its situation stably as the number one by the seismic reflection method occurred most lately, and its life has been further elongated by adopting digital techniques. The CDP technique which became to be used simultaneously, and the seismic sources without using explosives, such as vibro-seismic source and air gun, extended the success of digital techniques drastically. In the future, the progress of 3-D exploration technology is expected. In Japan, about 18 years lag in the seismic reflection method is observed when compared with the USA. Japan has provided leading techniques in the shallow layer seismic reflection method and S-wave exploration. 40 refs., 1 tab.

  9. Changes in Anti-Mullerian Hormone (AMH) throughout the Life Span: A Population-Based Study of 1027 Healthy Males from Birth (Cord Blood) to the Age of 69 Years

    DEFF Research Database (Denmark)

    Aksglæde, Lise; Sørensen, K; Boas, M.;

    2010-01-01

    Context: Anti-Mullerian hormone (AMH), which is secreted by immature Sertoli cells, triggers the involution of the fetal Mullerian ducts. AMH is a testis-specific marker used for diagnosis in infants with ambiguous genitalia or bilateral cryptorchidism. Aim: The aim of the study was to describe...... the ontogeny of AMH secretion through life in healthy males. Setting:This was a population-based study of healthy volunteers. Participants: Participants included 1027 healthy males from birth (cord blood) to 69 yr. A subgroup was followed up longitudinally through the infantile minipuberty [(in cord blood......, and at 3 and 12 months), n = 55] and another group through puberty [(biannual measurements), n = 83]. Main Outcome Measures: Serum AMH was determined by a sensitive immunoassay. Serum testosterone, LH, and FSH were measured, and pubertal staging was performed in boys aged 6 to 20 yr (n = 616). Results...

  10. Spanning Trees in Random Satisfiability Problems

    OpenAIRE

    Ramezanpour, A.; Moghimi-Araghi, S.

    2005-01-01

    Working with tree graphs is always easier than with loopy ones and spanning trees are the closest tree-like structures to a given graph. We find a correspondence between the solutions of random K-satisfiability problem and those of spanning trees in the associated factor graph. We introduce a modified survey propagation algorithm which returns null edges of the factor graph and helps us to find satisfiable spanning trees. This allows us to study organization of satisfiable spanning trees in t...

  11. 灵芝多糖对多刺裸腹溞存活、生殖及总SOD活性的影响%Effect of Ganoderma lucidum polysaccharides on the life-span, survival, reproduction quantity and activity of superoxide dismutase of Moina mocrocpa

    Institute of Scientific and Technical Information of China (English)

    张琛; 张瑛; 张宽朝; 冯颖杰

    2013-01-01

    采用多刺裸腹溞(Moina mocrocpa)作为实验动物,考察了不同浓度灵芝多糖对多刺裸腹溞寿命、存活率、生殖量和总超氧化物歧化酶(T-SOD)活性的影响.结果表明,灵芝多糖浓度为40~160mg/L时,多糖组多刺裸腹潘的平均寿命及存活率均明显高于对照组,同时对多刺裸腹溞的繁殖率也有显著影响;不同浓度的灵芝多糖均能促进多刺裸腹溞超氧化物歧化酶的活性的提高.结果为多刺裸腹溞作为衰老动物模型的应用提供了理论依据.%The Moina mocrocpa were used as materials to study the effection on life-span,survival,reproduction quantity and activity of superoxide dismutase ( T - SOD) with different Ganoderma lucidum polysaccharide concentrations. The results showed that while the concentration of Ganoderma lucidum polysaccharides was at 40~160mg/L,the survival rate and life span of Moina mocrocpa were significantly higher than that of the control, and the reproduction quantity of Moina mocrocpa was significantly higher than other groups.The SOD activitives in Moina mocrocpa with different polysaccharide concentrations were significantly higher than that of the control.The results provided the theory and practical parameters of Moina mocrocpa in application of animal model.

  12. Prospects for Chronological Studies of Martian Rocks and Soils

    Science.gov (United States)

    Nyquist, L. E.; Shih, C-Y.; Reese, Y. D.

    2008-01-01

    Chronological information about Martian processes comes from two sources: Crater-frequency studies and laboratory studies of Martian meteorites. Each has limitations that could be overcome by studies of returned Martian rocks and soils. Chronology of Martian volcanism: The currently accepted chronology of Martian volcanic surfaces relies on crater counts for different Martian stratigraphic units [1]. However, there is a large inherent uncertainty for intermediate ages near 2 Ga ago. The effect of differing preferences for Martian cratering chronologies [1] is shown in Fig. 1. Stoeffler and Ryder [2] summarized lunar chronology, upon which Martian cratering chronology is based. Fig. 2 shows a curve fit to their data, and compares to it a corresponding lunar curve from [3]. The radiometric ages of some lunar and Martian meteorites as well as the crater-count delimiters for Martian epochs [4] also are shown for comparison to the craterfrequency curves. Scaling the Stoeffler-Ryder curve by a Mars/Moon factor of 1.55 [5] places Martian shergottite ages into the Early Amazonian to late Hesperian epochs, whereas using the lunar curve of [3] and a Mars/Moon factor 1 consigns the shergottites to the Middle-to-Late Amazonian, a less probable result. The problem is worsened if a continually decreasing cratering rate since 3 Ga ago is accepted [6]. We prefer the adjusted St ffler-Ryder curve because it gives better agreement with the meteorite ages (Fig.

  13. Gamma spectrometry for chronology of recent sediments

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, Daniela

    2013-12-17

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). {sup 210}Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using {sup 210}Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide {sup 226}Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member {sup 222}Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported {sup 210}Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of {sup 214}Pb and {sup 214}Bi towards radioactive equilibrium with {sup 226}Ra in different containers were evaluated for analyses of {sup 226}Ra. Direct analyses of {sup 226}Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important

  14. Gamma spectrometry for chronology of recent sediments

    International Nuclear Information System (INIS)

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). 210Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using 210Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide 226Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member 222Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported 210Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of 214Pb and 214Bi towards radioactive equilibrium with 226Ra in different containers were evaluated for analyses of 226Ra. Direct analyses of 226Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important when combined profiles obtained from short multicorer cores

  15. Chronological development avenues in biotechnology across the world

    Directory of Open Access Journals (Sweden)

    Prashant Y Mali

    2011-01-01

    Full Text Available Biotechnology is expected to be a great technological revolution followed by information technology. It is an application of scientific and engineering principles to the processing of material by biological agents to provide better goods and services to mankind. Commercially its techniques are applied long back in 6 th century in the art of brewing, wine making and baking. It has progressed there after crossing different land marks. Modern biotechnology has developed significantly in the late 19 th century with groundbreaking discoveries applicable in medicine, food, agriculture, chemistry, environmental protection and many more industries. It is widely used in the development of high-yielding, disease-resistant, better quality varieties by applying tissue culture and recombinant DNA techniques. It has wide application in animal breeding using techniques such as artificial insemination, in vitro fertilization and embryo transfer. Specific enzymes used in laundry, fuel and leather industries for better quality, economically feasible and environmental friendly production. Biotechnology in healthcare system uses body′s own tools and weapons to fight against diseases, manufacturing of targeted therapeutic proteins, gene therapy and so on. Novel approaches such as proteomics and structural biology are contributing to understanding the chemistry of life and diseases. Malfunctioning gene replaced with correctly functioning gene by using gene therapy. Tissue engineering has opened up the use of in vitro developed tissue or organ in repairing wounded tissue and system biology which is a computer-based approach to understand cell functions. Although every new discovery related to biology and its implications is significant and has taken the technology ahead. This includes applications, commercialization, controversies, media exposure and so on. Hence, we have enlisted some of the chronological development avenues in biotechnology across the world.

  16. Nitrogen availability, leaf life span and nitrogen conservation mechanisms in leaves of tropical trees Disponibilidade de nitrogênio, longevidade foliar e mecanismos de conservação de nitrogênio em folhas de espécies arbóreas tropicais

    Directory of Open Access Journals (Sweden)

    Guilherme Nascimento Corte

    2009-12-01

    Full Text Available Evergreen species of temperate regions are dominant in low-nutrient soils. This feature is attributed to more efficient mechanisms of nutrient economy. Nevertheless, the cashew (Anacardium occidentale- Anacardiaceae, a deciduous species, is native to regions in Brazil with sandy soil, whilst the annatto (Bixa orellana- Bixaceae, classified as an evergreen species native to tropical America, grows spontaneously in regions with more humid soils. Evergreens contain robust leaves that can resist adverse conditions for longer. The physical aspects of the leaves and mechanisms of nutrient economy between the two species were compared, in order to verify whether the deciduous species had more efficient mechanisms that might explain its occurrence in regions of low soil fertility. The mechanisms of nitrogen economy were also compared for the two species at available concentrations of this nutrient. The following were analysed: (i leaf life span, (ii physical leaf characteristics (leaf mass per area, and rupture strain, (iii nitrogenous compounds (nitrogen, chlorophyll, and protein, (iv nitrogen conservation mechanisms (nitrogen resorption efficiency, resorption proficiency, and use efficiency, and (v nitrogen conservation mechanisms under different availability of this mineral. The higher values of leaf mass per area and leaf rupture strain found in A. occidentale were related to its longer leaf life span. A. occidentale showed lower concentrations of nitrogen and protein in the leaves than B. orellana. Under lower nitrogen availability, A. occidentale had higher nitrogen resorption proficiency, nitrogen use efficiency and leaf life span than B. orellana. These characteristics may contribute to the adaptation of this species to sandy soils with low nitrogen content.Perenifólias de clima temperado são dominantes em solos pouco férteis. Essa característica é atribuída a mecanismos mais eficientes de economia de nutrientes. O cajueiro (Anacardium

  17. Differentiation of Cognitive Abilities across the Life Span

    Science.gov (United States)

    Tucker-Drob, Elliot M.

    2009-01-01

    Existing representations of cognitive ability structure are exclusively based on linear patterns of interrelations. However, a number of developmental and cognitive theories predict that abilities are differentially related across ages (age differentiation-dedifferentiation) and across levels of functioning (ability differentiation). Nonlinear…

  18. Measuring Replicative Life Span in the Budding Yeast

    OpenAIRE

    Steffen, Kristan K.; Kennedy, Brian K.; Kaeberlein, Matt

    2009-01-01

    Aging is a degenerative process characterized by a progressive deterioration of cellular components and organelles resulting in mortality. The budding yeast Saccharomyces cerevisiae has been used extensively to study the biology of aging, and several determinants of yeast longevity have been shown to be conserved in multicellular eukaryotes, including worms, flies, and mice 1. Due to the lack of easily quantified age-associated phenotypes, aging in yeast has been assayed almost exclusively by...

  19. Patterns of Learning. New Perspectives on Life-Span Education.

    Science.gov (United States)

    Houle, Cyril O.

    Basic methods of learning, most of which have been used through centuries of recorded thought, are discussed, along with learning as a lifelong process, and ways to enhance and diversify modern education. Numerous learning processes are studied by examining the lives of great individuals who have exemplified innovative and multifaceted approaches…

  20. Assessing Executive Functions: A Life-Span Perspective

    Science.gov (United States)

    Reynolds, Cecil R.; Horton, Arthur MacNeill, Jr.

    2008-01-01

    Despite many disagreements on the utility of neuropsychological applications in schools, executive function measures have been found to be useful across a variety of areas and ages. In addition, many disagreements are extant in discussions of the maturational course of the development of executive functioning abilities that are dependent on…

  1. Online dating across the life span: Users' relationship goals.

    Science.gov (United States)

    Menkin, Josephine A; Robles, Theodore F; Wiley, Joshua F; Gonzaga, Gian C

    2015-12-01

    Utilizing data from an eHarmony.com relationship questionnaire completed by new users (N = 5,434), this study identifies prioritized goals in new romantic relationships and whether importance of these goals differs by participants' age and gender. Overall, users valued interpersonal communication more than sex appeal. Older users rated sexual attraction as slightly less important than younger users did, but they still highly valued the goal. Women placed even greater emphasis on communication over sexual attraction compared to men. However, although men valued sexual attraction more than women at all ages, only the youngest women valued interpersonal communication more than young men. PMID:26479015

  2. Stressful Jobs with Little Control/Shorter Life Spans?

    Science.gov (United States)

    ... done." The study was published recently in Personnel Psychology . SOURCES: Erik Gonzalez-Mule, Ph.D., assistant professor, organizational behavior and human resources, Indiana University's Kelley School of Business, Bloomington; Nellie Brown, M.S., director, Workplace Health and ...

  3. Colour Constancy Across the Life Span: Evidence for Compensatory Mechanisms

    OpenAIRE

    Sophie Wuerger

    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 compensa...

  4. Online dating across the life span: Users' relationship goals.

    Science.gov (United States)

    Menkin, Josephine A; Robles, Theodore F; Wiley, Joshua F; Gonzaga, Gian C

    2015-12-01

    Utilizing data from an eHarmony.com relationship questionnaire completed by new users (N = 5,434), this study identifies prioritized goals in new romantic relationships and whether importance of these goals differs by participants' age and gender. Overall, users valued interpersonal communication more than sex appeal. Older users rated sexual attraction as slightly less important than younger users did, but they still highly valued the goal. Women placed even greater emphasis on communication over sexual attraction compared to men. However, although men valued sexual attraction more than women at all ages, only the youngest women valued interpersonal communication more than young men.

  5. Emotion recognition in music changes across the adult life span.

    Science.gov (United States)

    Lima, Cesar F; Castro, Sao Luis

    2011-06-01

    In comparison with other modalities, the recognition of emotion in music has received little attention. An unexplored question is whether and how emotion recognition in music changes as a function of ageing. In the present study, healthy adults aged between 17 and 84 years (N=114) judged the magnitude to which a set of musical excerpts (Vieillard et al., 2008) expressed happiness, peacefulness, sadness and fear/threat. The results revealed emotion-specific age-related changes: advancing age was associated with a gradual decrease in responsiveness to sad and scary music from middle age onwards, whereas the recognition of happiness and peacefulness, both positive emotional qualities, remained stable from young adulthood to older age. Additionally, the number of years of music training was associated with more accurate categorisation of the musical emotions examined here. We argue that these findings are consistent with two accounts on how ageing might influence the recognition of emotions: motivational changes towards positivity and, to a lesser extent, selective neuropsychological decline.

  6. 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.

  7. Facial affect recognition across the adult life span

    OpenAIRE

    MOOSAVIAN, Elham; BORRY, Fatemeh

    2015-01-01

    Introduction: The results of the researches have shown expression and recognition of emotion are two of the basic skills on which normal social interaction is based. As people grow older, they may become wiser and more experienced in interacting with other people, but they can also experience memory loss and cognitive slow-down, influencing the quality of relations in their daily routines. Experimental studies indicate that facial affect recognition, particularly negative emotions, decreases ...

  8. Meditation improves self-regulation over the life span.

    Science.gov (United States)

    Tang, Yi-Yuan; Posner, Michael I; Rothbart, Mary K

    2014-01-01

    The use of meditation to improve emotion and attention regulation has a long history in Asia and there are many practitioners in Western countries. Much of the evidence on the effectiveness of meditation is either anecdotal or a comparison of long-term meditators with controls matched in age and health. Recently, it has been possible to establish changes in self-regulation in undergraduate students after only 5 days of meditation practice, allowing randomized trials comparing effects of meditation with other self-control methods such as relaxation training. Early studies took place in Chinese universities; however, similar effects have been obtained with U.S. undergraduates, and with Chinese children aged 4.5 years and older Chinese participants aged 65 years. Studies using neuroimaging techniques have shown that meditation improves activation and connectivity in brain areas related to self-regulation, and these findings may provide an opportunity to examine remediation of mental disorders in a new light.

  9. Daqing Plans Oil Production Reduction for Its Longer Life Span

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ The production target of Daqing Oil Field, China's largest oil deposit, will be cut by 2 million tons next year, after its output went below 50 million tons this year for the first time in two decades.

  10. Nature over nurture: temperament, personality, and life span development.

    Science.gov (United States)

    McCrae, R R; Costa, P T; Ostendorf, F; Angleitner, A; Hrebícková, M; Avia, M D; Sanz, J; Sánchez-Bernardos, M L; Kusdil, M E; Woodfield, R; Saunders, P R; Smith, P B

    2000-01-01

    Temperaments are often regarded as biologically based psychological tendencies with intrinsic paths of development. It is argued that this definition applies to the personality traits of the five-factor model. Evidence for the endogenous nature of traits is summarized from studies of behavior genetics, parent-child relations, personality structure, animal personality, and the longitudinal stability of individual differences. New evidence for intrinsic maturation is offered from analyses of NEO Five-Factor Inventory scores for men and women age 14 and over in German, British, Spanish, Czech, and Turkish samples (N = 5,085). These data support strong conceptual links to child temperament despite modest empirical associations. The intrinsic maturation of personality is complemented by the culturally conditioned development of characteristic adaptations that express personality; interventions in human development are best addressed to these.

  11. Nature over nurture: temperament, personality, and life span development.

    Science.gov (United States)

    McCrae, R R; Costa, P T; Ostendorf, F; Angleitner, A; Hrebícková, M; Avia, M D; Sanz, J; Sánchez-Bernardos, M L; Kusdil, M E; Woodfield, R; Saunders, P R; Smith, P B

    2000-01-01

    Temperaments are often regarded as biologically based psychological tendencies with intrinsic paths of development. It is argued that this definition applies to the personality traits of the five-factor model. Evidence for the endogenous nature of traits is summarized from studies of behavior genetics, parent-child relations, personality structure, animal personality, and the longitudinal stability of individual differences. New evidence for intrinsic maturation is offered from analyses of NEO Five-Factor Inventory scores for men and women age 14 and over in German, British, Spanish, Czech, and Turkish samples (N = 5,085). These data support strong conceptual links to child temperament despite modest empirical associations. The intrinsic maturation of personality is complemented by the culturally conditioned development of characteristic adaptations that express personality; interventions in human development are best addressed to these. PMID:10653513

  12. Spans in 2-Categories: A monoidal tricategory

    CERN Document Server

    Hoffnung, Alexander E

    2011-01-01

    We present Trimble's definition of a tetracategory and prove that the spans in (strict) 2-categories with certain limits have the structure of a monoidal tricategory, defined as a one-object tetracategory. We recall some notions of limits in 2-categories for use in the construction of the monoidal tricategory of spans.

  13. Performance, Career Dynamics, and Span of Control

    DEFF Research Database (Denmark)

    Smeets, Valerie Anne Rolande; Waldman, Michael; Warzynski, Frederic Michel Patrick

    ’s predictions concerning span of control including predictions derived from the learning component of the model. Overall, our investigation supports the notion that the scale-of-operations effect and additionally learning are important determinants of the internal organization of firms including span of control....... that higher ability managers should supervise more subordinates, or equivalently, have a larger span of control. And although some of this theory’s predictions have been empirically investigated, there has been little systematic investigation of the theory’s predictions concerning span of control....... In this paper we first extend the theoretical literature on the scale-of-operations effect to allow firms’ beliefs concerning a manager’s ability to evolve over the manager’s career, where much of our focus is the determinants of span of control. We then empirically investigate testable predictions from...

  14. Recent advances in long-term climate and moisture reconstructions from the Baltic region: Exploring the potential for a new multi-millennial tree-ring chronology

    Science.gov (United States)

    Edvardsson, Johannes; Corona, Christophe; Mažeika, Jonas; Pukienė, Rutile; Stoffel, Markus

    2016-01-01

    This study presents the first results from an ongoing initiative to develop a multi-millennial Baltic tree-ring width (TRW) chronology consisting of 12 floating records from subfossil Scots pines (Pinus sylvestris L.) extracted from three Lithuanian peat-mining areas. The floating series have been complemented with absolutely dated TRW chronologies which were obtained from living trees growing in unmanaged and unexploited peatland areas adjacent to each of the above study sites. The subfossil material has been dated by radiocarbon and shows a temporal spread over the last 6000 years, with assemblages of trees during the Holocene Thermal Maximum (HTM; 8000-4000 BP) and the onset of the Medieval Warm Period (MWP, AD 900-1350). Annual tree growth and sample replication of peatland pines reflect moisture variations and long-term climate variability. The importance of extending the TRW chronologies should not therefore be underestimated as (1) climate records of comparable length and resolution do not exist for the Baltic region, but also as (2) a result of a widespread lack of detailed moisture proxies spanning several millennia. Our data clearly show that a 6000-yr, continuous pine chronology from the Baltic region is a realistic objective, and would doubtlessly fill a major geographic gap in an ecologically sensitive region located at the interface between the temperate and boreal vegetation zones.

  15. Resveratrol Effects on Life Span and Fertility of Caenorhabditis Elegans Subject to 60Co Gamma Ray Irradiation%白藜芦醇对60Coγ射线照射线虫寿命和生殖的影响

    Institute of Scientific and Technical Information of China (English)

    叶侃; 季晨博; 郭锡熔; 古桂雄

    2011-01-01

    Caenorhabditis elegans was used as experimental model to investigate radiation effect of resveratol on caenorhabdities elegans irradiated by 60Co γray. Treatment with resveratrol can increase average life span and spawning rate, improve the surrival rate of eggs, and protect their mitochondrion function of cacnorhabdities elegans exposure to 60Co rr ray. The results indicate that resveratrol has radiation protection effects, which might be related to its action on ROS decrease and mitochondrial defend.%以线虫作为实验模型,观察白藜芦醇(RES)对受60Coγ射线照射线虫的保护作用.结果表明,白藜芦醇能提高受照射线虫的寿命,增加产卵率,提高卵的存活率,保护其线粒体功能.其作用机制可能与白藜芦醇减轻氧自由基所致的线虫线粒体损伤有关.

  16. Nurturing Children's Concepts of Time and Chronology through Literature

    Science.gov (United States)

    Harms, Jeanne McLain; Lettow, Lucille J.

    2007-01-01

    Time is an emerging concept during childhood. At first, children's concept of time is rather vague. Banks and Banks suggest that the goal for teaching time concepts and chronology in the elementary and middle school years should be to nurture students' ability to understand and interpret time concepts and comprehend how past and present events are…

  17. Signal Enhancement with Variable Span Linear Filters

    DEFF Research Database (Denmark)

    Benesty, Jacob; Christensen, Mads Græsbøll; Jensen, Jesper Rindom

    This book introduces readers to the novel concept of variable span speech enhancement filters, and demonstrates how it can be used for effective noise reduction in various ways. Further, the book provides the accompanying Matlab code, allowing readers to easily implement the main ideas discussed....... Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal......-to-noise ratio, Wiener, and tradeoff filters (including their new generalizations) can be obtained using the variable span filter framework. It then illustrates how the variable span filters can be applied in various contexts, namely in single-channel STFT-based enhancement, in multichannel enhancement in both...

  18. Signal enhancement with variable span linear filters

    CERN Document Server

    Benesty, Jacob; Jensen, Jesper R

    2016-01-01

    This book introduces readers to the novel concept of variable span speech enhancement filters, and demonstrates how it can be used for effective noise reduction in various ways. Further, the book provides the accompanying Matlab code, allowing readers to easily implement the main ideas discussed. Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal-to-noise ratio, Wiener, and tradeoff filters (including their new generalizations) can be obtained using the variable span filter framework. It then illustrates how the variable span filters can be applied in various contexts, namely in single-channel STFT-based enhancement, in multichannel enhancement in both the time and STFT domains, and, lastly, in time-domain binaural enhancement. In these contexts, the properties of ...

  19. Experimental study of single span railway bridges

    OpenAIRE

    Rigueiro, Constança; Rebelo, C.; Silva, L. Simões da

    2007-01-01

    The main purpose of this paper is to present some results concerning the investigation that has been done by the authors regarding the dynamic response of small to médium span railway bridges using response acceleration data colleted during the measurements carried out on single span bridges on the railway track Linz-Wels, in Austria. Using output-only methods in this experimental program, it was possible to have an estimation of the igenfrequencies, mode shapes and the corresponding viscous ...

  20. Reduced span spray – Part 1: Retention

    OpenAIRE

    Massinon, Mathieu; De Cock, Nicolas; Ouled Taleb Salah, Sofiene; Lebeau, Frédéric

    2016-01-01

    Maximising treatment efficiency for a given target lies mainly on depositing a maximum part of the spray volume within an optimal droplet size range, which has to be as narrow as possible to reduce retention variability and drift issues. The present work focuses on exploring the effect of span factor of the droplet size distribution on the final retention by a 3D target plant using a modelling approach with the final aim of guiding the development of a reduced span nozzle (Redu...

  1. A Survey of the Xia-Shang-Zhou Chronology Project

    Institute of Scientific and Technical Information of China (English)

    Xi Zezong

    2002-01-01

    @@ Ⅰ. Goals In connection with the history of science, the XiaShang-Zhou Chronology Project is one of the important projects of the National Key Science and Technology Research and Development Programme of the Ninth Five-Year Plan. It officially began in May 1996.After five years of effort by more than 200 scholars and experts from the Chinese Academy of Sciences,the Chinese Academy of Social Sciences, Peking University and other institutions, the project has attained its goal. The general goal of the project is to establish a chronological table for the three dynasties by means of combining the humanities and social sciences with the natural sciences. The concrete goals for different historical periods are:

  2. Energy history chronology from World War II to the present

    Energy Technology Data Exchange (ETDEWEB)

    Dean, P.C.

    1982-08-01

    This report provides a basic guide to the major Presidential, Legislative, Judicial, and Federal agency actions relating to energy policy, research, development, and regulation in recent years. The chronology is arranged synoptically, allowing users to reference easily the historical context in which each event occurred. Summaries of Presidential, Legislative, and Judicial actions relating to energy, rosters of federal energy officials, and a genealogy of federal energy agencies are also provided in separate appendices. The Energy History Chronology was prepared in conjunction with the History Division's series of pamphlets on the Institutional Origins of the Department of Energy. The series includes concise histories of the Department of Energy, the Energy Research and Development Administration, the Federal Energy Administration, and the Atomic Energy Commission. All significant events and achievements noted in the institutional history are also listed.

  3. Chronology protection in stationary three-dimensional spacetimes

    CERN Document Server

    Raeymaekers, Joris

    2011-01-01

    We study chronology protection in stationary, rotationally symmetric spacetimes in 2+1 dimensional gravity, focusing especially on the case of negative cosmological constant. We show that in such spacetimes closed timelike curves must either run all the way to the boundary or, alternatively, the matter stress tensor must violate the null energy condition in the bulk. We also show that the matter in the closed timelike curve region gives a negative contribution to the conformal weight from the point of view of the dual conformal field theory. We illustrate these properties in a class of examples involving rotating dust in anti-de Sitter space, and comment on the use of the AdS/CFT correspondence to study chronology protection.

  4. The use of AMS radiocarbon dating for Xia-Shang-Zhou chronology

    CERN Document Server

    Guo, Z Y; LiuKeXin; Lu Xiang Yang; Ma Hong Ji; Wu Xiao Hon; Yuan Si Xun

    2000-01-01

    The possibility and problems of using radiocarbon dating to historical chronology are discussed. The current situation of ancient Chinese chronology and the project of Xia-Shang-Zhou chronology are introduced. A chronological study requires the AMS radiocarbon dating with high precision, high reliability and high efficiency. The Peking University AMS facility (PKUAMS) has been upgraded and a series of quality control steps were adopted. To reduce the error of calendar age, wiggle matching with serial samples should be used. Some preliminary results of Xia-Shang-Zhou chronology are presented.

  5. Behavior of three-span braced columns with equal and unequal spans

    OpenAIRE

    Yang, Yu-Wen

    1993-01-01

    Columns with three spans separated by elastic braces are analyzed. The influences of translational and rotational resistance at the braces, various end conditions, and the bracing locations for the perfect columns with equal and unequal spans subjected to uniform and nonuniform axial load are investigated. For imperfect columns with equal or unequal spans subjected to uniform compression, the effects of various end conditions at the top and various initial deflections are studied. "Ide...

  6. REVIEW: South & East Asian Adult Education: Chronologies in Commonwealth Countries

    OpenAIRE

    SHARMA, Reviewed By Dr. Ramesh C.

    2002-01-01

    The major aim of this international research project was to record and analyze the chronological development of adult education in the country members of the commonwealth. It traces the developments in the area of adult education since early 1900s to the very latest as for 1999. This project was supported by the Commonwealth of Learning; the Ontario Institute for Studies in Education, University of Toronto; the Commonwealth Association for the Education and Training of Adults; and the United ...

  7. The Chronology of Third Molar Eruption in the Croatian Population

    OpenAIRE

    Brkić, Hrvoje; Vodanović, Marin; Dumančić, Jelena; Lovrić, Željka; Čuković-Bagić, Ivana; Petrovečki, Mladen

    2011-01-01

    Dental age estimation is common in orthodontics, paedodontics, paleodontology and forensic dentistry. The aim of this study was to assess chronological course of eruptive developmental phases of third molar and to establish parameters for the Croatian population. Sample of this study consisted of 1249 orthopantomograms of 530 (42.4%) male and 719 (57.6%) female subjects, aged 10 to 25 years. Eruptive phases were classified in 4 stages. No significant sex difference was found. Esta...

  8. Asbestos: a chronology of its origins and health effects.

    OpenAIRE

    Huncharek, M

    1990-01-01

    The emotionalised subject of asbestos is treated in chronological terms: how the "magic mineral" known in ancient times in Europe and Asia became in the late nineteenth century an important industrial resource of particular interest to the navies of the world; and how its malign effects gradually became apparent during the present century. The media have made asbestos a notorious villain, but it still has properties and applications useful to society if they are properly controlled in the sam...

  9. Tanshinones extend chronological lifespan in budding yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Wu, Ziyun; Song, Lixia; Liu, Shao Quan; Huang, Dejian

    2014-10-01

    Natural products with anti-aging property have drawn great attention recently but examples of such compounds are exceedingly scarce. By applying a high-throughput assay based on yeast chronological lifespan measurement, we screened the anti-aging activity of 144 botanical materials and found that dried roots of Salvia miltiorrhiza Bunge have significant anti-aging activity. Tanshinones isolated from the plant including cryptotanshione, tanshinone I, and tanshinone IIa, are the active components. Among them, cryptotanshinone can greatly extend the budding yeast Saccharomyces cerevisiae chronological lifespan (up to 2.5 times) in a dose- and the-time-of-addition-dependent manner at nanomolar concentrations without disruption of cell growth. We demonstrate that cryptotanshinone prolong chronological lifespan via a nutrient-dependent regime, especially essential amino acid sensing, and three conserved protein kinases Tor1, Sch9, and Gcn2 are required for cryptotanshinone-induced lifespan extension. In addition, cryptotanshinone significantly increases the lifespan of SOD2-deleted mutants. Altogether, those data suggest that cryptotanshinone might be involved in the regulation of, Tor1, Sch9, Gcn2, and Sod2, these highly conserved longevity proteins modulated by nutrients from yeast to humans.

  10. Construction of reliable radiocarbon-based chronologies for speleothems

    Science.gov (United States)

    Lechleitner, Franziska; Fohlmeister, Jens; McIntyre, Cameron; Baldini, Lisa M.; Jamieson, Robert A.; Hercman, Helena; Gasiorowski, Michal; Pawlak, Jacek; Stefaniak, Krzysztof; Socha, Pawel; Eglinton, Timothy I.; Baldini, James U. L.

    2016-04-01

    Speleothems have become one of the most widely applied archives for paleoclimate research. One of their key advantages is their amenability for U-series dating, often producing excellent high precision chronologies. However, stalagmites with high detrital Th or very low U concentrations are problematic to date using U-series, and sometimes need to be discarded from further paleoclimate analysis. Radiocarbon chronologies could present an alternative for stalagmites that cannot be dated using U-series, if offsets from the "dead carbon fraction" (DCF) can be resolved. The DCF is a variable reservoir effect introduced by the addition of 14C-dead carbon from host rock dissolution and soil organic matter. We present a novel age modeling technique that provides accurate 14C-based chronologies for stalagmites. As this technique focuses on the long-term decay pattern of 14C, it is only applicable on stalagmites that show no secular variability in their 14C-depth profiles, but is independent of short-term DCF variations. In order to determine whether a stalagmite is suitable for this method without direct knowledge of long-term trends in the DCF, we highlight how other geochemical proxies (δ13C, Mg/Ca) can provide additional information on changes in karst hydrology, soil conditions, and climate that would affect DCF. We apply our model on a previously published U-Th dated stalagmite 14C dataset from Heshang Cave, China with excellent results, followed by a previously 'undateable' stalagmite from southern Poland.

  11. A novel web-based TinT application and the chronology of the Primate Alu retroposon activity

    Directory of Open Access Journals (Sweden)

    Makałowski Wojciech

    2010-12-01

    Full Text Available Abstract Background DNA sequences afford access to the evolutionary pathways of life. Particularly mobile elements that constantly co-evolve in genomes encrypt recent and ancient information of their host's history. In mammals there is an extraordinarily abundant activity of mobile elements that occurs in a dynamic succession of active families, subfamilies, types, and subtypes of retroposed elements. The high frequency of retroposons in mammals implies that, by chance, such elements also insert into each other. While inactive elements are no longer able to retropose, active elements retropose by chance into other active and inactive elements. Thousands of such directional, element-in-element insertions are found in present-day genomes. To help analyze these events, we developed a computational algorithm (Transpositions in Transpositions, or TinT that examines the different frequencies of nested transpositions and reconstructs the chronological order of retroposon activities. Results By examining the different frequencies of such nested transpositions, the TinT application reconstructs the chronological order of retroposon activities. We use such activity patterns as a comparative tool to (1 delineate the historical rise and fall of retroposons and their relations to each other, (2 understand the retroposon-induced complexity of recent genomes, and (3 find selective informative homoplasy-free markers of phylogeny. The efficiency of the new application is demonstrated by applying it to dimeric Alu Short INterspersed Elements (SINE to derive a complete chronology of such elements in primates. Conclusion The user-friendly, web-based TinT interface presented here affords an easy, automated screening for nested transpositions from genome assemblies or trace data, assembles them in a frequency-matrix, and schematically displays their chronological activity history.

  12. Impounding Experimental Research of Large Span Aqueduct

    OpenAIRE

    Huafeng Deng; Min Zhu; Xianfan Yuan; Qian Luo

    2013-01-01

    In this study, we have a research of the impounding experimental research of large span aqueduct. Caohe aqueduct is the mark building of the middle line of the South-to-North Water Diversion Project, of which the span is 30m. For this aqueduct, the structure is relatively complicated with great technical difficulties, what’s more there's no engineering experience or theoretical method to provide reference in domestic and abroad. It can be seen clear that whether the actual stressing state, de...

  13. Dentulous Appliance for Upper Anterior Edentulous Span

    OpenAIRE

    Chalakkal, Paul; Devi, Ramisetty Sabitha; Srinivas, G Vijay; Venkataramana, Pammi

    2013-01-01

    This article discusses about a fixed dentulous appliance that was constructed to replace the primary upper anterior edentulous span in a four year old girl. It constituted a design, whereby the maxillary primary second molars were used to support the appliance through bands and a wire that contained an acrylic flange bearing trimmed acrylic teeth, anteriorly. The appliance was functionally and aesthetically compliant.

  14. Spanning organizational boundaries to manage creative processes:

    DEFF Research Database (Denmark)

    Andersen, Poul Houman; Kragh, Hanne; Lettl, Christopher

    2013-01-01

    In order to continue to be innovative in the current fast-paced and competitive environment, organizations are increasingly dependent on creative inputs developed outside their boundaries. The paper addresses the boundary spanning activities that managers undertake to a) select and mobilize creat...

  15. 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.

  16. 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.

  17. Evaluating the efficiency of shortcut span protection

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Dittmann, Lars; Berger, Michael Stübert;

    2010-01-01

    This paper presents a comparison of various recovery methods in terms of capacity efficiency with the underlying aim of reducing control plane load. In particular, a method where recovery requests are bundled towards the destination (Shortcut Span Protection) is evaluated can compared against...

  18. Critical review of a new volcanic eruption chronology

    Science.gov (United States)

    Neuhäuser, Dagmar L.; Neuhäuser, Ralph

    2016-04-01

    Sigl. et al. (2015, Nature) present historical evidence for 32 volcanic eruptions to evaluate their new polar ice core 10-Be chronology - 24 are dated within three years of sulfur layers in polar ice. Most of them can be interpreted as weather phenomena (Babylonia: disk of sun like moon, reported for only one day, e.g. extinction due to clouds), Chinese sunspot reports (pellet, black vapor, etc.), solar eclipses, normal ice-halos and coronae (ring, bow, etc.), one aurora (redness), red suns due to mist drops in wet fog or fire-smoke, etc. Volcanic dust may facilitate detections of sunspots and formation of Bishop's ring, but tend to inhibit ice-halos, which are otherwise often reported in chronicles. We are left with three reports possibly indicating volcanic eruptions, namely fulfilling genuine criteria for atmospheric disturbances due to volcanic dust, e.g. bluish or faint sun, orange sky, or fainting of stars for months (BCE 208, 44-42, and 32). Among the volcanic eruptions used to fix the chronology (CE 536, 626, 939, 1257), the reports cited for the 930s deal only with 1-2 days, at least one reports an eclipse. In the new chronology, there is a sulfur detection eight years after the Vesuvius eruption, but none in CE 79. It may appear surprising that, from BCE 500 to 1, all five northern sulfur peaks labeled in figure 2 in Sigl et al. are systematically later by 2-4 years than the (corresponding?) southern peaks, while all five southern peaks from CE 100 to 600 labeled in figure 2 are systematically later by 1-4 years than the (corresponding?) northern peaks. Furthermore, in most of their six strongest volcanic eruptions, temperatures decreased years before their sulfur dating - correlated with weak solar activity as seen in radiocarbon, so that volcanic climate forcing appears dubious here. Also, their 10-Be peaks at CE 775 and 994 are neither significant nor certain in dating.

  19. Chronology of Mercury's geological and geophysical evolution - the Vulcanoid hypothesis

    International Nuclear Information System (INIS)

    The possibility that constraints on Mercury's chronology can be relaxed through reference to a Mercury-specific bombarding population of planetesimals interior to its orbit, and therefore only occasionally encountering the planet at times of secular perturbations, is investigated. While such vulcanoids may have been a significant source of early cratering, those in the pertinent orbits are depleted by mutual collisions and can therefore only furnish a modest extension of the heavy bombardment period. A search is conducted for vulcanoids further within Mercury's orbit; evidence that Mercury's intercrater plains are of volcanic origin is discussed. 99 references

  20. A new chronology for the Moon and Mercury

    CERN Document Server

    Marchi, S; Cremonese, G; Massironi, M; Martellato, E

    2009-01-01

    In this paper we present a new method for dating the surface of the Moon, obtained by modeling the incoming flux of impactors and converting it into a size distribution of resulting craters. We compare the results from this model with the standard chronology for the Moon showing their similarities and discrepancies. In particular, we find indications of a non-constant impactor flux in the last 500 Myr and also discuss the implications of our findings for the Late Heavy Bombardment hypothesis. We also show the potential of our model for accurate dating of other inner Solar System bodies, by applying it to Mercury.

  1. Extension of Chronological Calculus for Dynamical Systems on Manifolds

    OpenAIRE

    Kipka, Robert J.; Ledyaev, Yuri S.

    2014-01-01

    We propose an extension of the Chronological Calculus, developed by Agrachev and Gamkrelidze for the case of $C^\\infty$-smooth dynamical systems on finite-dimensional $C^\\infty$-smooth manifolds, to the case of $C^m$-smooth dynamical systems and infinite-dimensional $C^m$-manifolds. Due to a relaxation in the underlying structure of the calculus, this extension provides a powerful computational tool without recourse to the theory of calculus in Fr\\'echet spaces required by the classical Chron...

  2. The problem of the neolithisation process chronology in Povolzhye

    Directory of Open Access Journals (Sweden)

    Aleksandr Vybornov

    2013-12-01

    Full Text Available The Lower and Middle Volga basin regions border the Caucasus and Central Asia in the South. These regions are important in the study of the neolithisation process in Europe and the chronology of Neolithic cultures is of great significance in this respect. New 14C dates of different organic materials from archaeological sites in these regions have been obtained in the last five years. According to these data, the beginning of neolithisation in North Caspian region can be dated to the beginning of the 5th millennium BC; but in the Povolzhye it happened at least a millennium earlier.

  3. Organic carbon sedimentation rates in Asian mangrove coastal ecosystems estimated by {sup 210}PB chronology

    Energy Technology Data Exchange (ETDEWEB)

    Tateda, Y.; Wattayakorn, G.; Nhan, D.D.; Kasuya, Y. [Abiko Research Laboratory CRIEPI, Biology Dept., Abiko, Chiba (Japan)

    2004-07-01

    Organic carbon balance estimation of mangrove coastal ecosystem is important for understanding of Asian coastal carbon budget/flux calculation in global carbon cycle modelling which is powerful tool for the prediction of future greenhouse gas effect and evaluation of countermeasure preference. Especially, the organic carbon accumulation rate in mangrove ecosystem was reported to be important sink of carbon as well as that in boreal peat accumulation. For the estimation of 10{sup 3} years scale organic carbon accumulation rates in mangrove coastal ecosystems, {sup 14}C was used as long term chronological tracer, being useful in pristine mangrove forest reserve area. While in case of mangrove plantation of in coastal area, the {sup 210}Pb is suitable for the estimation of decades scale estimation by its half-life. Though it has possibility of bio-/physical- turbation effect in applying {sup 210}Pb chronology that is offset in case of 10{sup 3} years scale estimation, especially in Asian mangrove ecosystem where the anthropogenic physical turbation by coastal fishery is vigorous.In this paper, we studied the organic carbon and {sup 210}Pb accumulation rates in subtropical mangrove coastal ecosystems in Japan, Vietnam and Thailand with {sup 7}Be analyses to make sure the negligible effect of above turbation effects on organic carbon accumulation. We finally concluded that {sup 210}Pb was applicable to estimate organic carbon accumulation rates in these ecosystems even though the physical-/bio-turbation is expected. The measured organic carbon accumulation rates using {sup 210}Pb in mangrove coastal ecosystems of Japan, Vietnam and Thailand were 0.067 4.0 t-C ha{sup -1} y{sup -1}. (author)

  4. Octave Spanning Frequency Comb on a Chip

    CERN Document Server

    Del'Haye, P; Gavartin, E; Holzwarth, R; Kippenberg, T J

    2009-01-01

    Optical frequency combs have revolutionized the field of frequency metrology within the last decade and have become enabling tools for atomic clocks, gas sensing and astrophysical spectrometer calibration. The rapidly increasing number of applications has heightened interest in more compact comb generators. Optical microresonator based comb generators bear promise in this regard. Critical to their future use as 'frequency markers', is however the absolute frequency stabilization of the optical comb spectrum. A powerful technique for this stabilization is self-referencing, which requires a spectrum that spans a full octave, i.e. a factor of two in frequency. In the case of mode locked lasers, overcoming the limited bandwidth has become possible only with the advent of photonic crystal fibres for supercontinuum generation. Here, we report for the first time the generation of an octave-spanning frequency comb directly from a toroidal microresonator on a silicon chip. The comb spectrum covers the wavelength range...

  5. Interorganizational Boundary Spanning in Global Software Development

    DEFF Research Database (Denmark)

    Søderberg, Anne-Marie; Romani, Laurence

    , and which skills and competencies they draw on in their efforts to deal with emerging cross-cultural issues in a way that paves ground for developing a shared understanding and common platform for the client and vendor representatives. A framework of boundary spanning leadership practices is adapted...... to virtuality and cultural diversity. This paper, which draws on a case study of collaborative work in a global software development project, focuses on key boundary spanners in an Indian vendor company, who are responsible for developing trustful and sustainable client relations and coordinating complex...... projects across multiple cultures, languages, organisational boundaries, time zones and geographical distances. It looks into how these vendor managers get prepared for their complex boundary spanning work, which cross-cultural challenges they experience in their collaboration with Western clients...

  6. Boundary Spanning in Global Software Development

    DEFF Research Database (Denmark)

    Søderberg, Anne-Marie; Romani, Laurence

    How does a global company deal with inter-organizational boundary spanning activities? If the company is an Indian vendor, and the client a Western multinational company in need of major transformations, the answer to this question challenges prior research. This paper builds on a field study...... of Indian IT vendor managers who are responsible for developing client relations and coordinating complex global development projects. The authors revise a framework of boundary spanning leadership practices to adapt it to an offshore outsourcing context. The empirical investigation highlights how...... imbalances of power, exacerbated in the case of an Indian vendor and a European client, need to be taken into account. The paper thus contributes with a more context sensitive understanding of inter-organizational boundary work. Taking the vendor perspective also leads to problematization of common...

  7. Spanning forests on the Sierpinski gasket

    Directory of Open Access Journals (Sweden)

    Shu-Chiuan Chang

    2008-04-01

    Full Text Available We present the numbers of spanning forests on the Sierpinski gasket $SG_d(n$ at stage $n$ with dimension $d$ equal to two, three and four, and determine the asymptotic behaviors. The corresponding results on the generalized Sierpinski gasket $SG_{d,b}(n$ with $d=2$ and $b=3,4$ are obtained. We also derive the upper bounds of the asymptotic growth constants for both $SG_d$ and $SG_{2,b}$.

  8. Robustness of Long Span Reciprocal Timber Structures

    DEFF Research Database (Denmark)

    Balfroid, Nathalie; Kirkegaard, Poul Henning; Sassone, Mario SASSONE

    2011-01-01

    engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper makes a discussion of such robustness issues related to the future development of reciprocal timber structures. The paper concludes that these kind of structures can have...... a potential as long span timber structures in real projects if they are carefully designed with respect to the overall robustness strategies....

  9. Vision in Flies: Measuring the Attention Span.

    Science.gov (United States)

    Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

    2016-01-01

    A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

  10. Vision in Flies: Measuring the Attention Span.

    Directory of Open Access Journals (Sweden)

    Sebastian Koenig

    Full Text Available A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA. The animal is said to have a focus of attention (FoA which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

  11. Spanning trees and the Eurozone crisis

    Science.gov (United States)

    Dias, João

    2013-12-01

    The sovereign debt crisis in the euro area has not yet been solved and recent developments in Spain and Italy have further deteriorated the situation. In this paper we develop a new approach to analyze the ongoing Eurozone crisis. Firstly, we use Maximum Spanning Trees to analyze the topological properties of government bond rates’ dynamics. Secondly, we combine the information given by both Maximum and Minimum Spanning Trees to obtain a measure of market dissimilarity or disintegration. Thirdly, we extend this measure to include a convenient distance not limited to the interval [0, 2]. Our empirical results show that Maximum Spanning Tree gives an adequate description of the separation of the euro area into two distinct groups: those countries strongly affected by the crisis and those that have remained resilient during this period. The measures of market dissimilarity also reveal a persistent separation of these two groups and, according to our second measure, this separation strongly increased during the period July 2009-March 2012.

  12. Impounding Experimental Research of Large Span Aqueduct

    Directory of Open Access Journals (Sweden)

    Huafeng Deng

    2013-04-01

    Full Text Available In this study, we have a research of the impounding experimental research of large span aqueduct. Caohe aqueduct is the mark building of the middle line of the South-to-North Water Diversion Project, of which the span is 30m. For this aqueduct, the structure is relatively complicated with great technical difficulties, what’s more there's no engineering experience or theoretical method to provide reference in domestic and abroad. It can be seen clear that whether the actual stressing state, deformation conditions and prestressed tension effect etc. meet the design requirements will directly affect the safe operation of aqueduct, so the impounding experiment of the aqueduct was carried out before formal operation. At the meanwhile, the deformation characteristics and stress characteristics of the aqueduct under various impounding conditions were analyzed in detail. The experiment results analysis shows that, the aqueduct structure is under a good elastic working condition with only 0.98mm maximum deflection deformation at mid-span, which meets the design and specification requirements. At the same time, all of the measure point’s stress is in the range of designed material, which means the structure form is safe and reliable and can meet the requirements of the later operation good.

  13. Chronologic changes of free fat graft in rabbit using CT

    International Nuclear Information System (INIS)

    Free fat grafts are now used for preventing osteal readhesion, filling dead space, and protecting grafted nerves and vessels. However, it is reported that grafted fat tissue is unstable resulting in high risk of cicatrization and infection. We grafted free fat to a rabbit's back and observed the chronologic change using CT. Ten adult male Japanese white rabbits (3.5 kg) were used. In five rabbits, fat tissue was obtained from the back under general anaesthesia, and transplanted into the back about 50 mm posterior from the donor site. CT was taken in the fixed scan condition five times (preoperation, immediate postoperation, postoperative 1-month, 2-month, and 3-month). In the remaining five rabbits, only CT scan was taken three times as a control. It was observed that we compared preoperative fat volume with the postoperative volume using RealINTAGE. Grafted fat tissue decreased postoperatively at 1-month and completely disappeared at 3-months. We were able to prove that CT scan is effective to observe the chronologic change of grafted fat tissue. Techniques of tissue engineering are necessary for survival of grafted fat tissue. (author)

  14. Contribution of adipose tissue to health span and longevity.

    Science.gov (United States)

    Huffman, Derek M; Barzilai, Nir

    2010-01-01

    Adipose tissue accounts for approximately 20% (lean) to >50% (in extreme obesity) of body mass and is biologically active through its secretion of numerous peptides and release and storage of nutrients such as free fatty acids. Studies in rodents and humans have revealed that body fat distribution, including visceral fat (VF), subcutaneous (SC) fat and ectopic fat are critical for determining the risk posed by obesity. Specific depletion or expansion of the VF depot using genetic or surgical strategies in animal models has proven to have direct effects on metabolic characteristics and disease risk. In humans, there is compelling evidence that abdominal obesity most strongly predicts mortality risk, while in rats, surgical removal of VF improves mean and maximum life span. There is also growing evidence that fat deposition in ectopic depots such as skeletal muscle and liver can cause lipotoxicity and impair insulin action. Conversely, expansion of SC adipose tissue may confer protection from metabolic derangements by serving as a 'metabolic sink' to limit both systemic lipids and the accrual of visceral and ectopic fat. Treatments targeting the prevention of fat accrual in these harmful depots should be considered as a primary target for improving human health span and longevity. PMID:20703052

  15. Teaching about September 11th and Its Aftermath. C-SPAN in the Classroom.

    Science.gov (United States)

    C-SPAN, Washington, DC.

    The events of and since September 11, 2001 have had an immeasurable impact on all facets of people's lives, especially in the United States. The loss of human life, threatened public safety, and the impact of a military response are just some of the issues concerning U.S. citizens and public officials. This C-SPAN in the Classroom series offers…

  16. A calibrated chronology of biochemistry reveals a stem line of descent responsible for planetary biodiversity

    Directory of Open Access Journals (Sweden)

    Gustavo eCaetano-Anollés

    2014-09-01

    Full Text Available Time-calibrated phylogenomic trees of protein domain structure produce powerful chronologies describing the evolution of biochemistry and life. These timetrees are built from a genomic census of millions of encoded proteins using models of nested accumulation of molecules in evolving proteomes. Here we show that a primordial stem line of descent, a propagating series of pluripotent cellular entities, populates the deeper branches of the timetrees. The stem line produced for the first time cellular grades ~2.9 billion years (Gy-ago, which slowly turned into lineages of superkingdom Archaea. Prompted by the rise of planetary oxygen and aerobic metabolism, the stem line also produced bacterial and eukaryal lineages. Superkingdom-specific domain repertoires emerged ~2.1 Gy-ago delimiting fully diversified Bacteria. Repertoires specific to Eukarya and Archaea appeared 300 millions years later. Results reconcile reductive evolutionary processes leading to the early emergence of Archaea to superkingdom-specific innovations compatible with a tree of life rooted in Bacteria.

  17. Biological versus chronological ovarian age: implications for assisted reproductive technology

    Directory of Open Access Journals (Sweden)

    Tredway Donald

    2009-09-01

    Full Text Available Abstract Background Women have been able to delay childbearing since effective contraception became available in the 1960s. However, fertility decreases with increasing maternal age. A slow but steady decrease in fertility is observed in women aged between 30 and 35 years, which is followed by an accelerated decline among women aged over 35 years. A combination of delayed childbearing and reduced fecundity with increasing age has resulted in an increased number and proportion of women of greater than or equal to 35 years of age seeking assisted reproductive technology (ART treatment. Methods Literature searches supplemented with the authors' knowledge. Results Despite major advances in medical technology, there is currently no ART treatment strategy that can fully compensate for the natural decline in fertility with increasing female age. Although chronological age is the most important predictor of ovarian response to follicle-stimulating hormone, the rate of reproductive ageing and ovarian sensitivity to gonadotrophins varies considerably among individuals. Both environmental and genetic factors contribute to depletion of the ovarian oocyte pool and reduction in oocyte quality. Thus, biological and chronological ovarian age are not always equivalent. Furthermore, biological age is more important than chronological age in predicting the outcome of ART. As older patients present increasingly for ART treatment, it will become more important to critically assess prognosis, counsel appropriately and optimize treatment strategies. Several genetic markers and biomarkers (such as anti-Müllerian hormone and the antral follicle count are emerging that can identify women with accelerated biological ovarian ageing. Potential strategies for improving ovarian response include the use of luteinizing hormone (LH and growth hormone (GH. When endogenous LH levels are heavily suppressed by gonadotrophin-releasing hormone analogues, LH supplementation may help

  18. Decentralized Pricing in Minimum Cost Spanning Trees

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moulin, Hervé; Østerdal, Lars Peter

    In the minimum cost spanning tree model we consider decentralized pricing rules, i.e. rules that cover at least the ecient cost while the price charged to each user only depends upon his own connection costs. We de ne a canonical pricing rule and provide two axiomatic characterizations. First......, the canonical pricing rule is the smallest among those that improve upon the Stand Alone bound, and are either superadditive or piece-wise linear in connection costs. Our second, direct characterization relies on two simple properties highlighting the special role of the source cost....

  19. Variable Span Filters for Speech Enhancement

    DEFF Research Database (Denmark)

    Jensen, Jesper Rindom; Benesty, Jacob; Christensen, Mads Græsbøll

    2016-01-01

    distortion. Subspace approaches, on the other hand, can potentially yield better control by filtering in the eigen-domain, but traditionally these approaches have not been optimized explicitly for traditional noise reduction and signal distortion measures. Herein, we combine these approaches by deriving...... optimal filters using a joint diagonalization as a basis. This gives excellent control over the performance, as we can optimize for noise reduction or signal distortion performance. Results from real data experiments show that the proposed variable span filters can achieve better performance than existing...

  20. Signal Enhancement with Variable Span Linear Filters

    DEFF Research Database (Denmark)

    Benesty, Jacob; Christensen, Mads Græsbøll; Jensen, Jesper Rindom

    . Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal...... the time and STFT domains, and, lastly, in time-domain binaural enhancement. In these contexts, the properties of these filters are analyzed in terms of their noise reduction capabilities and desired signal distortion, and the analyses are validated and further explored in simulations....

  1. Stable, Renormalizable, Scalar Tachyonic Quantum Field Theory with Chronology Protection

    CERN Document Server

    Radzikowski, Marek J

    2008-01-01

    We use microlocal arguments to suggest that Lorentz symmetry breaking must occur in a reasonably behaved tachyonic quantum field theory that permits renormalizability. In view of this, we present a scalar tachyonic quantum field model with manifestly broken Lorentz symmetry and without exponentially growing/decaying modes. A notion of causality, in which anti-telephones are excluded, and which is viewed as a form of chronology protection, is obeyed. The field theory is constructed in a preferred tachyon frame in terms of commuting creation/annihilation operators. We calculate some sample (renormalized) operators in this preferred frame, argue that the Hadamard condition is satisfied, and discuss the PCT and spin-statistics theorems for this model.

  2. Ştefania Cristescu-Golopenţia's Chronology

    Directory of Open Access Journals (Sweden)

    SANDA GOLOPENŢIA

    2013-07-01

    Full Text Available The present Chronology brings together data from the personal archive of Şt.C.-G. with data accumulated during the editing of her published and posthumous work that Sanda Golopenţia undertook after 1989. The author specifically calls attention to the new data regarding Şt.C.-G.'s 1938 and 1939 regional research in Ţara Oltului (the Olt County, the research she conducted in 1945 and 1947 in the Gurghiu Valley, and the social inquiry on the daily lives of her students in the Industrial Colege "Protopopul Tudor Economul" from Bucharest (1942-1943. The bibliography of St.C.-G.'s sociological, pedagogical and literary works was updated.

  3. Origin and chronology of chondritic components: A review

    Science.gov (United States)

    Krot, A. N.; Amelin, Y.; Bland, P.; Ciesla, F. J.; Connelly, J.; Davis, A. M.; Huss, G. R.; Hutcheon, I. D.; Makide, K.; Nagashima, K.; Nyquist, L. E.; Russell, S. S.; Scott, E. R. D.; Thrane, K.; Yurimoto, H.; Yin, Q.-Z.

    2009-09-01

    Mineralogical observations, chemical and oxygen-isotope compositions, absolute 207Pb- 206Pb ages and short-lived isotope systematics ( 7Be- 7Li, 10Be- 10B, 26Al- 26Mg, 36Cl- 36S, 41Ca- 41K, 53Mn- 53Cr, 60Fe- 60Ni, 182Hf- 182W) of refractory inclusions [Ca,Al-rich inclusions (CAIs) and amoeboid olivine aggregates (AOAs)], chondrules and matrices from primitive (unmetamorphosed) chondrites are reviewed in an attempt to test (i) the x-wind model vs. the shock-wave model of the origin of chondritic components and (ii) irradiation vs. stellar origin of short-lived radionuclides. The data reviewed are consistent with an external, stellar origin for most short-lived radionuclides ( 7Be, 10Be, and 36Cl are important exceptions) and a shock-wave model for chondrule formation, and provide a sound basis for early Solar System chronology. They are inconsistent with the x-wind model for the origin of chondritic components and a local, irradiation origin of 26Al, 41Ca, and 53Mn. 10Be is heterogeneously distributed among CAIs, indicating its formation by local irradiation and precluding its use for the early solar system chronology. 41Ca- 41K, and 60Fe- 60Ni systematics are important for understanding the astrophysical setting of Solar System formation and origin of short-lived radionuclides, but so far have limited implications for the chronology of chondritic components. The chronological significance of oxygen-isotope compositions of chondritic components is limited. The following general picture of formation of chondritic components is inferred. CAIs and AOAs were the first solids formed in the solar nebula ˜4567-4568 Myr ago, possibly within a period of events in nebular region(s) with high ambient temperature (at or above condensation temperature of forsterite), either throughout the inner protoplanetary disk (1-4 AU) or in a localized region near the proto-Sun ( -10‰) and have ( 26Al/ 27Al) 0 similar to those in chondrules (events in regions with low ambient temperature

  4. Chronology and origin of VMS deposits in Xinjiang, NW CHINA

    Institute of Scientific and Technical Information of China (English)

    CHEN; Fuwen(陈富文); LI; Huaqin(李华芹); WANG; Denghong(王登红); XIE; Caifu(谢才富); LU; Yuanfa(路远发)

    2002-01-01

    VMS deposits in Xinjiang, NW China are widespread in the Altay, Tianshan and West Kunlun orogenic belt, mainly formed during the Proterozoic rifting and Phanerozoic post-orogenic extension and are related to the bimodal volcanism. The VMS deposits are middle and small in scale. According to assemblages of metallogenetic elements, they can be divided into four types (Cu-Zn, Cu-S, Pb-Zn-Cu and Pb-Zn types) with the Cu-Zn and Pb-Zn types being the most important ones. Research of isotopic chronology shows that the VMS deposits in Xinjiang were formed during the Proterozoic, Ordovician, Deovonian, Carboniferous and Permian periods and usually underwent multi-stage mineralization, especially the large-sized deposits usually have post- volcanic superimposed mineralization by tectonomagmatic or metamorphic hydrothermal metallogenic fluids.

  5. Frost-ring chronologies as dendroclimatic proxies of boreal environments

    Science.gov (United States)

    Payette, Serge; Delwaide, Ann; Simard, Martin

    2010-01-01

    Frost rings are formed in tree stems when growing-season frosts affect immature wood cells, producing collapsed cells within annual tree rings. Open boreal forests are most susceptible to record growing-season frost because they lack the greenhouse effect commonly observed in closed forests. Here we present a novel method to construct regional frost-ring chronologies in lichen-black spruce woodlands of the boreal forest zone. Because the ability of trees to form frost rings depends on several factors (including bark thickness and ring width), we used two models to produce a Frost Composite Index based on a frost susceptibility window of cambial age growing-season frost activity may be used as dendroclimatic proxies of climate variability and may give insights into future risks of frost damage in a warming climate.

  6. Holographic Protection of Chronology in Universes of the Godel Type

    CERN Document Server

    Boyda, E; Horava, P; Varadarajan, U; Boyda, Edward; Ganguli, Surya; Horava, Petr; Varadarajan, Uday

    2003-01-01

    We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on "phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Godel universes has many features in common with de Sitter space, suggesting that Godel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of "microscopic" aspects of holography of Godel universes in string theory. We show that Godel universes are T-dual to pp-waves, and use...

  7. Statehood Day or Candlemas Day: Ideology vs. Chronology

    Directory of Open Access Journals (Sweden)

    Srđan Milošević

    2016-03-01

    Full Text Available The paper deals with the ideological and chronological issues concerning Statehood day, which is celebrated on the 15th and 16th of February in Serbia. The focus will be on the connection which is being established between the state holiday of Statehood day and Candlemas Day which is a church holiday. The paper will further deal with the problems with dating the two key events – the start of the First Serbian Uprising in 1804 and the adoption of the first Serbian Constitution in 1835 – which, according to the Serbian law on national and other holidays, form the basis for the celebrating of Statehood day. The paper will prove that it wasn’t necessary for the legislators to insist on establishing a connection between the aforementioned events and the date of the church holiday neither in the 19th nor in the 21st century. The author will also point out the significant errors in chronology: it is falsely claimed that the anniversaries of both these events coincide with Candlemas Day (in 1804 and 1835, respectively, and that it is hence unwarranted to claim that they coincide with Candlemas Day in the 21st century. It will be shown that the reason for these errors lies in the incorrect calculation and translation of dates from the Julian into the Gregorian calendar, as well as that the contemporary insistence on the connection between Statehood day and Candlemas Day is ideologically conditioned and that it is a consequence of the desecularization of Serbian society.

  8. Environmental factors influence lesser scaup migration chronology and population monitoring

    Science.gov (United States)

    Finger, Taylor A.; Afton, Alan D.; Schummer, Michael L.; Petrie, Scott A.; Badzinski, Shannon S.; Johnson, Michael A.; Szymanski, Michael L.; Jacobs, Kevin J.; Olsen, Glenn H.; Mitchell, Mark

    2016-01-01

    Identifying environmental metrics specific to lesser scaup (Aythya affinis; scaup) spring migration chronology may help inform development of conservation, management and population monitoring. Our objective was to determine how environmental conditions influence spring migration of lesser scaup to assess the effectiveness of the Waterfowl Breeding Population and Habitat Survey in accurately estimating scaup populations. We first compared peak timing of mallard (Anas platyrhynchos) and scaup migration from weekly ground surveys in North Dakota, USA because the Waterfowl Breeding Population and Habitat Survey is designed to capture annual mallard migration. As predicted, we detected that peak timing of scaup and mallard migrations differed in 25 of 36 years investigated (1980–2010). We marked scaup with satellite transmitters (n = 78; 7,403 locations) at Long Point, Lake Erie, Ontario, Canada; Pool 19 of the Mississippi River, Iowa and Illinois, USA; and Presque Isle Bay, Lake Erie, Pennsylvania, USA. We tested the assumption that our marked scaup were representative of the continental population using the traditional survey area by comparing timing of migration of marked birds and scaup counted in the North Dakota Game and Fish Department survey. We detected a strong positive correlation between marked scaup and the survey data, which indicated that marked scaup were representative of the population. We subsequently used our validated sample of marked scaup to investigate the effects of annual variation in temperature, precipitation, and ice cover on spring migration chronology in the traditional and eastern survey areas of the Waterfowl Breeding Population and Habitat Survey, 2005–2010. We evaluated competing environmental models to explain variation in timing and rate of scaup migration at large-scale and local levels. Spring migration of scaup occurred earlier and faster during springs with warmer temperatures and greater precipitation, variables known

  9. Relationships between Chronological Age, Developmental Age, and Standardized Achievement Tests in Kindergarten.

    Science.gov (United States)

    Freberg, Laura

    1991-01-01

    Evaluated chronological age and results of Gesell School Readiness Test as predictors of kindergarten performance as measured by Stanford Achievement Test. Results from 284 kindergarten children indicated that both chronological and developmental age provided good predictors of Stanford Achievement Test performance in kindergarten. Findings have…

  10. TELL SABI ABYAD, SYRIA : RADIOCARBON CHRONOLOGY, CULTURAL CHANGE, AND THE 8.2 KA EVENT

    NARCIS (Netherlands)

    van der Plicht, J.; Akkermans, P. M. M. G.; Nieuwenhuyse, O.; Kaneda, A.; Russell, A.

    2011-01-01

    At Tell Sabi Abyad, Syria, we obtained a robust chronology for the 7th to early 6th millennium BC, the Late Neolithic. The chronology was obtained using a large set of radiocarbon dates, analyzed by Bayesian statistics. Cultural changes observed at similar to 6200 BC are coeval with the 8.2 ka clima

  11. An 854-Year Tree-Ring Chronology of Scots Pine for South-West Finland

    Directory of Open Access Journals (Sweden)

    Helama Samuli

    2014-04-01

    Full Text Available A near-millennial tree-ring chronology (AD 1147-2000 is presented for south-west Finland and analyzed using dendroclimatic methods. This is a composite chronology comprising samples both from standing pine trees (Pinus sylvestris L. and subfossil trunks as recovered from the lake sediments, with a total sample size of 189 tree-ring sample series. The series were dendrochronologically cross-dated to exact calendar years to portray variability in tree-ring widths on inter-annual and longer scales. Al though the studied chronology correlates statistically significantly with other long tree-ring width chronologies from Finland over their common period (AD 1520-1993, the south-west chronology did not exhibit similarly strong mid-summer temperature or spring/early-summer precipitation signals in comparison to published chronologies. On the other hand, the south-west chronology showed highest correlations to the North Atlantic Oscillation indices in winter/spring months, this association following a dendroclimatic feature common to pine chronologies over the region and adjacent areas. Paleoclimatic comparison showed that tree-rings had varied similarly to central European spring temperatures. It is postulated that the collected and dated tree-ring material could be studied for wood surface reflectance (blue channel light intensity and stable isotopes, which both have recently shown to correlate notably well with summer temperatures.

  12. Life in Transition

    DEFF Research Database (Denmark)

    Overgaard, Dorthe; Grufstedt Kjeldgaard, Heidi; Egerod, Ingrid

    2012-01-01

    . OBJECTIVE:: The aim of this study was to explore the lived experience of patients with LVAD. METHODS:: The present study had a qualitative explorative design using in-depth interviews of 10 adult patients that had experienced life with an LVAD from 2008 to 2010 in Denmark. We constructed an interview guide......BACKGROUND:: A left ventricular assist device (LVAD) is used as a bridge to transplantation in patients with acute heart failure. The device is a major bodily invasion that challenges everyday life. Only few studies have explored the psychosocial adjustments of patients living with an LVAD...... with themes relating to the chronology of the illness trajectory. Data were managed by the qualitative computer package NVivo 8. As a theoretical framework, we chose a life-stage model for the main theme: Life With LVAD. The model describes the developmental tasks in each age group, and we looked...

  13. Matroidal Degree-Bounded Minimum Spanning Trees

    CERN Document Server

    Zenklusen, Rico

    2011-01-01

    We consider the minimum spanning tree (MST) problem under the restriction that for every vertex v, the edges of the tree that are adjacent to v satisfy a given family of constraints. A famous example thereof is the classical degree-constrained MST problem, where for every vertex v, a simple upper bound on the degree is imposed. Iterative rounding/relaxation algorithms became the tool of choice for degree-bounded network design problems. A cornerstone for this development was the work of Singh and Lau, who showed for the degree-bounded MST problem how to find a spanning tree violating each degree bound by at most one unit and with cost at most the cost of an optimal solution that respects the degree bounds. However, current iterative rounding approaches face several limits when dealing with more general degree constraints. In particular, when several constraints are imposed on the edges adjacent to a vertex v, as for example when a partition of the edges adjacent to v is given and only a fixed number of elemen...

  14. A reevaluation of the Pallett Creek earthquake chronology based on new AMS radiocarbon dates, San Andreas fault, California

    Science.gov (United States)

    Scharer, K.M.; Biasi, G.P.; Weldon, R.J.

    2011-01-01

    The Pallett Creek paleoseismic record occupies a keystone position in most attempts to develop rupture histories for the southern San Andreas fault. Previous estimates of earthquake ages at Pallett Creek were determined by decay counting radiocarbon methods. That method requires large samples which can lead to unaccounted sources of uncertainty in radiocarbon ages because of the heterogeneous composition of organic layers. In contrast, accelerator mass spectrometry (AMS) radiocarbon dates may be obtained from small samples that have known carbon sources and also allow for a more complete sampling of the section. We present 65 new AMS radiocarbon dates that span nine ground-rupturing earthquakes at Pallett Creek. Overall, the AMS dates are similar to and reveal no dramatic bias in the conventional dates. For many layers, however, individual charcoal samples were younger than the conventional dates, leading to earthquake ages that are overall slightly younger than previously reported. New earthquake ages are determined by Bayesian refinement of the layer ages based on stratigraphic ordering and sedimentological constraints. The new chronology is more regular than previously published records in large part due to new samples constraining the age of event R. The closed interval from event C to 1857 has a mean recurrence of 135years (?? = 83.2 years) and a quasiperiodic coefficient of variation (COV) of 0.61. We show that the new dates and resultant earthquake chronology have a stronger effect on COV than the specific membership of this long series and dating precision improvements from sedimentation rates. Copyright 2011 by the American Geophysical Union.

  15. Chronological dating and tectonic implications of late Cenozoic volcanic rocks and lacustrine sequence in Oiyug Basin of southern Tibet

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Reconstruction of uplift history of the Tibetan Plateau is crucial for understanding its environmental impacts. The Oiyug Basin in southern Tibet contains multiple periods of sedimentary sequences and volcanic rocks that span much of the Cenozoic and has great potential for further studying this issue. However, these strata were poorly dated. This paper presents a chronological study of the 145 m thick and horizontally-distributed lacustrine sequence using paleomagnetic method as well as a K-Ar dating of the underlying volcanic rocks. Based on these dating results, a chronostratigraphic framework and the basin-developmental history have been established for the past 15 Ma, during which three tectonic stages are identified. The period of 15-8.1 Ma is characterized by intense volcanic activities involving at least three major eruptions. Subsequently, the basin came into a tectonically quiescent period and a lacustrine sedimentary sequence was developed. Around 2.5 Ma, an N-S fault occurred across the southern margin of the basin, leading to the disappearance of the lake environment and the development of the Oiyug River. The Gyirong basin on northern slope of the Himalayas shows a similar basin developmental history and thus there is a good agreement in tectonic activities between the Himalayan and Gangdise orogenic belts. Therefore, the tectonic evolution stages experienced by the Oiyug Basin during the past 15 Ma could have a regional significance for southern Tibet. The chronological data obtained from this study may provide some constraints for further studies with regard to the tectonic processes and environmental changes in southern Tibetan Plateau.

  16. Integrating Barriers to Caucasian Lesbians' Career Development and Super's Life-Span, Life-Space Approach

    Science.gov (United States)

    House, Chloe J. C.

    2004-01-01

    Researchers and practitioners do not fully understand the nature and extent of actual and perceived barriers in lesbians' career development (S. L. Morrow, P. A. Gore, & B. W. Campbell, 1996). In this study, 10 lesbian women, ages 42 to 64 years, were interviewed and asked to identify barriers to career development due to sexual identity.…

  17. 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…

  18. Inter-tegular span and head width as estimators of fresh and dry body mass in bumblebees (Bombus spp.)

    DEFF Research Database (Denmark)

    Hagen, Melanie; Dupont, Yoko

    2013-01-01

    Adult body mass is a strong correlate of many important life history traits of bees, and thus, has been used as a proxy for these traits in ecological studies. However, body mass is difficult to measure on live specimens in the field, and impossible to measure non-destructively on dry museum...... specimens. For worker and male bumblebees, we evaluated the linear measures inter-tegular span (IT span) and head width as predictors of fresh and dry weight. For males, linear regressions best explained the relationship between fresh and dry weight and the linear size estimators, while for workers......, polynomial regressions best explained this relationship. We found that both IT span and head width are precise estimators of weights of bumblebees. Head width was a slightly better predictor for male weights, while IT span was a slightly better predictor of worker weights. IT span and head width changed...

  19. Faster generation of random spanning trees

    CERN Document Server

    Kelner, Jonathan A

    2009-01-01

    In this paper, we set forth a new algorithm for generating approximately uniformly random spanning trees in undirected graphs. We show how to sample from a distribution that is within a multiplicative $(1+\\delta)$ of uniform in expected time $\\TO(m\\sqrt{n}\\log 1/\\delta)$. This improves the sparse graph case of the best previously known worst-case bound of $O(\\min \\{mn, n^{2.376}\\})$, which has stood for twenty years. To achieve this goal, we exploit the connection between random walks on graphs and electrical networks, and we use this to introduce a new approach to the problem that integrates discrete random walk-based techniques with continuous linear algebraic methods. We believe that our use of electrical networks and sparse linear system solvers in conjunction with random walks and combinatorial partitioning techniques is a useful paradigm that will find further applications in algorithmic graph theory.

  20. Galactic Archaeology and Minimum Spanning Trees

    CERN Document Server

    Macfarlane, B A; Flynn, C M L

    2015-01-01

    Chemical tagging of stellar debris from disrupted open clusters and associations underpins the science cases for next-generation multi-object spectroscopic surveys. As part of the Galactic Archaeology project TraCD (Tracking Cluster Debris), a preliminary attempt at reconstructing the birth clouds of now phase-mixed thin disk debris is undertaken using a parametric minimum spanning tree (MST) approach. Empirically-motivated chemical abundance pattern uncertainties (for a 10-dimensional chemistry-space) are applied to NBODY6-realised stellar associations dissolved into a background sea of field stars, all evolving in a Milky Way potential. We demonstrate that significant population reconstruction degeneracies appear when the abundance uncertainties approach 0.1 dex and the parameterised MST approach is employed; more sophisticated methodologies will be required to ameliorate these degeneracies.

  1. Turning Simple Span into Complex Span: Time for Decay or Interference from Distractors?

    Science.gov (United States)

    Lewandowsky, Stephan; Geiger, Sonja M.; Morrell, Daniel B.; Oberauer, Klaus

    2010-01-01

    We investigated the effects of the duration and type of to-be-articulated distractors during encoding of a verbal list into short-term memory (STM). Distractors and to-be-remembered items alternated during list presentation, as in the complex-span task that underlies much of working-memory research. According to an interference model of STM, known…

  2. 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.

  3. Characterising the Welsh Roundhouse: chronology, inhabitation and landscape

    Directory of Open Access Journals (Sweden)

    Eleanor Ghey

    2007-11-01

    Full Text Available The article stems from a one-year project funded by the University of Wales Board of Celtic Studies to collect and analyse all the evidence for excavated prehistoric and early historic roundhouses in Wales. The resulting dataset will serve as a resource for researchers and, through the analysis provided in this article, provide an important counterpoint to similar studies from elsewhere in Britain. The methodology of the project is presented, and the limitations of the data are discussed in detail. The principal difficulties were associated with dating the building and duration of use of individual structures, and the bias created by a few sites with large numbers of excavated structures. The analysis and interpretation of the data is presented in three sections: chronology, inhabitation and landscape, and historical overview. The emphasis on recently excavated sites with good chronological control has enabled a more confident reconstruction of the history of roundhouse occupation in Wales. This has shown that while the architectural form has relatively early origins with numbers beginning to grow after 1500 BC, it is primarily a feature of first millennium BC and early first millennium AD landscapes. During the first millennium BC, timber- and stone-built settlements are common, initially as enclosed sites, and later, by the Roman period, as both open and enclosed settlements. This is contrary to the situation in many other parts of Britain, where roundhouses and frequently field systems are dated to at least the mid-second millennium BC onwards. There were strong regional differences between regions at this time, with for instance the predominance of stone- and clay-built sites in north-west Wales and the absence of Roman period roundhouses in the north-east. The dataset derived from the project will remain as an important resource with which to research these regional differences in greater detail and to examine the implications of new

  4. Heritability Estimates of Endophenotypes of Long and Health Life: The Long Life Family Study

    DEFF Research Database (Denmark)

    Matteini, Amy M; Fallin, M Daniele; Kammerer, Candace M;

    2010-01-01

    BACKGROUND: Identification of gene variants that contribute to exceptional survival may provide critical biologic information that informs optimal health across the life span. METHODS: As part of phenotype development efforts for the Long Life Family Study, endophenotypes that represent exceptional...

  5. TimeSpan: Using Visualization to Explore Temporal Multi-dimensional Data of Stroke Patients.

    Science.gov (United States)

    Loorak, Mona Hosseinkhani; Perin, Charles; Kamal, Noreen; Hill, Michael; Carpendale, Sheelagh

    2016-01-01

    We present TimeSpan, an exploratory visualization tool designed to gain a better understanding of the temporal aspects of the stroke treatment process. Working with stroke experts, we seek to provide a tool to help improve outcomes for stroke victims. Time is of critical importance in the treatment of acute ischemic stroke patients. Every minute that the artery stays blocked, an estimated 1.9 million neurons and 12 km of myelinated axons are destroyed. Consequently, there is a critical need for efficiency of stroke treatment processes. Optimizing time to treatment requires a deep understanding of interval times. Stroke health care professionals must analyze the impact of procedures, events, and patient attributes on time-ultimately, to save lives and improve quality of life after stroke. First, we interviewed eight domain experts, and closely collaborated with two of them to inform the design of TimeSpan. We classify the analytical tasks which a visualization tool should support and extract design goals from the interviews and field observations. Based on these tasks and the understanding gained from the collaboration, we designed TimeSpan, a web-based tool for exploring multi-dimensional and temporal stroke data. We describe how TimeSpan incorporates factors from stacked bar graphs, line charts, histograms, and a matrix visualization to create an interactive hybrid view of temporal data. From feedback collected from domain experts in a focus group session, we reflect on the lessons we learned from abstracting the tasks and iteratively designing TimeSpan.

  6. Holographic Protection of Chronology in Universes of the Godel Type

    Energy Technology Data Exchange (ETDEWEB)

    Boyda, Edward; Ganguli, Surya; Horava, Petr; Varadarajan, Uday

    2002-12-07

    We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on"phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Godel universes has many features in common with de Sitter space, suggesting that Godel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of"microscopic" aspects of holography of Godel universes in string theory. We show that Godel universes are T-dual to pp-waves, and use this fact to generate new Godel-like solutions of string and M-theory by T-dualizing known supersymmetric pp-wave solutions.

  7. On the Chronological Structure of the Solutrean in Southern Iberia.

    Science.gov (United States)

    Cascalheira, João; Bicho, Nuno

    2015-01-01

    The Solutrean techno-complex has gained particular significance over time for representing a clear demographic and techno-typological deviation from the developments occurred during the course of the Upper Paleolithic in Western Europe. Some of Solutrean's most relevant features are the diversity and techno-typological characteristics of the lithic armatures. These have been recurrently used as pivotal elements in numerous Solutrean-related debates, including the chronological organization of the techno-complex across Iberia and Southwestern France. In Southern Iberia, patterns of presence and/or absence of specific point types in stratified sequences tend to validate the classical ordering of the techno-complex into Lower, Middle and Upper phases, although some evidence, namely radiocarbon determinations, have not always been corroborative. Here we present the first comprehensive analysis of the currently available radiocarbon data for the Solutrean in Southern Iberia. We use a Bayesian statistical approach from 13 stratified sequences to compare the duration, and the start and end moments of each classic Solutrean phase across sites. We conclude that, based on the current data, the traditional organization of the Solutrean cannot be unquestionably confirmed for Southern Iberia, calling into doubt the status of the classically-defined type-fossils as precise temporal markers.

  8. On the Chronological Structure of the Solutrean in Southern Iberia.

    Directory of Open Access Journals (Sweden)

    João Cascalheira

    Full Text Available The Solutrean techno-complex has gained particular significance over time for representing a clear demographic and techno-typological deviation from the developments occurred during the course of the Upper Paleolithic in Western Europe. Some of Solutrean's most relevant features are the diversity and techno-typological characteristics of the lithic armatures. These have been recurrently used as pivotal elements in numerous Solutrean-related debates, including the chronological organization of the techno-complex across Iberia and Southwestern France. In Southern Iberia, patterns of presence and/or absence of specific point types in stratified sequences tend to validate the classical ordering of the techno-complex into Lower, Middle and Upper phases, although some evidence, namely radiocarbon determinations, have not always been corroborative. Here we present the first comprehensive analysis of the currently available radiocarbon data for the Solutrean in Southern Iberia. We use a Bayesian statistical approach from 13 stratified sequences to compare the duration, and the start and end moments of each classic Solutrean phase across sites. We conclude that, based on the current data, the traditional organization of the Solutrean cannot be unquestionably confirmed for Southern Iberia, calling into doubt the status of the classically-defined type-fossils as precise temporal markers.

  9. Chronological aging in conidia of pathogenic Aspergillus: Comparison between species.

    Science.gov (United States)

    Oliveira, Manuela; Pereira, Clara; Bessa, Cláudia; Araujo, Ricardo; Saraiva, Lucília

    2015-11-01

    Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus and Aspergillus niger are common airborne fungi, and the most frequent causative agents of human fungal infections. However, the resistance and lifetime persistence of these fungi in the atmosphere, and the mechanism of aging of Aspergillus conidia are unknown.With this work, we intended to study the processes underlying conidial aging of these four relevant and pathogenic Aspergillus species. Chronological aging was therefore evaluated in A. fumigatus, A. flavus, A. terreus and A. niger conidia exposed to environmental and human body temperatures. The results showed that the aging process in Aspergillus conidia involves apoptosis,with metacaspase activation, DNA fragmentation, and reactive oxygen species production, associated with secondary necrosis. Distinct results were observed for the selected pathogenic species. At environmental conditions, A. niger was the species with the highest resistance to aging, indicating a higher adaption to environmental conditions, whereas A. flavus followed by A. terreus were the most sensitive species. At higher temperatures (37 °C), A. fumigatus presented the longest lifespan, in accordance with its good adaptation to the human body temperature. Altogether,with this work new insights regarding conidia aging are provided, which may be useful when designing treatments for aspergillosis.

  10. Molecular biomarkers for chronological age in animal ecology.

    Science.gov (United States)

    Jarman, Simon N; Polanowski, Andrea M; Faux, Cassandra E; Robbins, Jooke; De Paoli-Iseppi, Ricardo; Bravington, Mark; Deagle, Bruce E

    2015-10-01

    The chronological age of an individual animal predicts many of its biological characteristics, and these in turn influence population-level ecological processes. Animal age information can therefore be valuable in ecological research, but many species have no external features that allow age to be reliably determined. Molecular age biomarkers provide a potential solution to this problem. Research in this area of molecular ecology has so far focused on a limited range of age biomarkers. The most commonly tested molecular age biomarker is change in average telomere length, which predicts age well in a small number of species and tissues, but performs poorly in many other situations. Epigenetic regulation of gene expression has recently been shown to cause age-related modifications to DNA and to cause changes in abundance of several RNA types throughout animal lifespans. Age biomarkers based on these epigenetic changes, and other new DNA-based assays, have already been applied to model organisms, humans and a limited number of wild animals. There is clear potential to apply these marker types more widely in ecological studies. For many species, these new approaches will produce age estimates where this was previously impractical. They will also enable age information to be gathered in cross-sectional studies and expand the range of demographic characteristics that can be quantified with molecular methods. We describe the range of molecular age biomarkers that have been investigated to date and suggest approaches for developing the newer marker types as age assays in nonmodel animal species.

  11. The chronology of third molar mineralization by digital orthopantomography.

    Science.gov (United States)

    Maled, Venkatesh; Vishwanath, S B

    2016-10-01

    The present study was designed to determine the chronology of third molar mineralization to establish Indian reference data and to observe the advantages of digital orthopantomography. Therefore, a cross-sectional study was undertaken by evaluating 167 digital orthopantomographs in order to assess the mineralization status of the mandibular third molar of Caucasian individuals (85 males and 82 females) between the age of 14 and 24. The evaluation was carried out using the 8-stage developmental scheme of Demirjian et al (1973). The range, mean age, standard deviation and Student t-test are presented for each stage of mineralization in all four quadrants. Statistically significant differences between males and females were not found for all four third molars. All the individuals in this study with mature third molar were at least 18 years of age. For medicolegal purposes, the likelihood of whether an Indian is older than 18 years or not was determined. The advantage of digital orthopantomography in the interpretation of the tooth mineralization over the traditional method was acknowledged. PMID:27485643

  12. The chronology of third molar mineralization by digital orthopantomography.

    Science.gov (United States)

    Maled, Venkatesh; Vishwanath, S B

    2016-10-01

    The present study was designed to determine the chronology of third molar mineralization to establish Indian reference data and to observe the advantages of digital orthopantomography. Therefore, a cross-sectional study was undertaken by evaluating 167 digital orthopantomographs in order to assess the mineralization status of the mandibular third molar of Caucasian individuals (85 males and 82 females) between the age of 14 and 24. The evaluation was carried out using the 8-stage developmental scheme of Demirjian et al (1973). The range, mean age, standard deviation and Student t-test are presented for each stage of mineralization in all four quadrants. Statistically significant differences between males and females were not found for all four third molars. All the individuals in this study with mature third molar were at least 18 years of age. For medicolegal purposes, the likelihood of whether an Indian is older than 18 years or not was determined. The advantage of digital orthopantomography in the interpretation of the tooth mineralization over the traditional method was acknowledged.

  13. Growth Culture Conditions and Nutrient Signaling Modulating Yeast Chronological Longevity

    Directory of Open Access Journals (Sweden)

    Júlia Santos

    2012-01-01

    Full Text Available The manipulation of nutrient-signaling pathways in yeast has uncovered the impact of environmental growth conditions in longevity. Studies using calorie restriction show that reducing glucose concentration of the culture media is sufficient to increase replicative and chronological lifespan (CLS. Other components of the culture media and factors such as the products of fermentation have also been implicated in the regulation of CLS. Acidification of the culture media mainly due to acetic acid and other organic acids production negatively impacts CLS. Ethanol is another fermentative metabolite capable of inducing CLS reduction in aged cells by yet unknown mechanisms. Recently, ammonium was reported to induce cell death associated with shortening of CLS. This effect is correlated to the concentration of NH4+ added to the culture medium and is particularly evident in cells starved for auxotrophy-complementing amino acids. Studies on the nutrient-signaling pathways regulating yeast aging had a significant impact on aging-related research, providing key insights into mechanisms that modulate aging and establishing the yeast as a powerful system to extend knowledge on longevity regulation in multicellular organisms.

  14. Sediment accumulation, stratigraphic order, and the extent of time-averaging in lagoonal sediments: a comparison of 210Pb and 14C/amino acid racemization chronologies

    Science.gov (United States)

    Kosnik, Matthew A.; Hua, Quan; Kaufman, Darrell S.; Zawadzki, Atun

    2015-03-01

    Carbon-14 calibrated amino acid racemization (14C/AAR) data and lead-210 (210Pb) data are used to examine sediment accumulation rates, stratigraphic order, and the extent of time-averaging in sediments collected from the One Tree Reef lagoon (southern Great Barrier Reef, Australia). The top meter of lagoonal sediment preserves a stratigraphically ordered deposit spanning the last 600 yrs. Despite different assumptions, the 210Pb and 14C/AAR chronologies are remarkably similar indicating consistency in sedimentary processes across sediment grain sizes spanning more than three orders of magnitude (0.1-10 mm). Estimates of long-term sediment accumulation rates range from 2.2 to 1.2 mm yr-1. Molluscan time-averaging in the taphonomically active zone is 19 yrs, whereas below the depth of final burial (~15 cm), it is ~110 yrs/5 cm layer. While not a high-resolution paleontological record, this reef lagoon sediment is suitable for paleoecological studies spanning the period of Western colonization and development. This sedimentary deposit, and others like it, should be useful, albeit not ideal, for quantifying anthropogenic impacts on coral reef systems.

  15. Reduced span spray: Part 3: Design of a narrow span nozzle

    OpenAIRE

    De Cock, Nicolas; Massinon, Mathieu; Ouled Taleb Salah, Sofiene; Lebeau, Frédéric

    2016-01-01

    Optimisation of the droplet spectra of the agricultural spray may increase the spray application efficiency. The optimal spray would contain only the most efficient droplets in term of speed and size. Therefore, this paper is presenting the first steps of the design of a narrow span nozzle in order to produce an optimised spray. The starting geometry is a splash plate nozzle with a disk ending with structures (i.e. tooth, grooves, and needles) that would separate the liquid sheet...

  16. Life after the Principalship

    Science.gov (United States)

    Schmidt, Laurel

    2009-01-01

    Sixty-eight percent of people who are approaching retirement age report that they intend to work full time or part time after retirement, mostly because they want to. With today's life span stretching to 80 years and beyond, turning 60 is no longer an end-stage event. Instead, it is the beginning of a new developmental phase. This article…

  17. Nutrient Limitation of Microbial Mediated Decomposition and Arctic Soil Chronology

    Science.gov (United States)

    Melle, C. J.; Darrouzet-Nardi, A.; Wallenstein, M. D.

    2012-12-01

    Soils of northern permafrost regions currently contain twice as much carbon as the entire Earth's atmosphere. Traditionally, environmental constraints have limited microbial activity resulting in restricted decomposition of soil organic matter in these systems and accumulation of massive amounts of soil organic carbon (SOC), however climate change is reducing the constraints of decomposition in arctic permafrost regions. Carbon cycling in nutrient poor, arctic ecosystems is tightly coupled to other biogeochemical cycles. Several studies have suggested strong nitrogen limitations of primary productivity and potentially warm-season microbial activity in these nutrient deficient soils. Nitrogen is required for microbial extracellular enzyme production which drives the decomposition of soil organic matter (SOM). Nitrogen limited arctic soils may also experience limitation via labile carbon availability despite the SOM rich environment due to low extracellular enzyme production. Few studies have directly addressed nutrient induced microbial limitation in SOC rich arctic tundra soils, and even less is known about the potential for nutrient co-limitation. Additionally, through the process of becoming deglaciated, sites within close proximity to one another may have experienced drastic differences in their effective soil ages due to the varied length of their active histories. Many soil properties and nutrient deficiencies are directly related to soil age, however this chronology has not previously been a focus of research on nutrient limitation of arctic soil microbial activity. Understanding of nutrient limitations, as well as potential co-limitation, on arctic soil microbial activity has important implications for carbon cycling and the ultimate fate of the current arctic SOC reservoir. Analyses of nutrient limitation on soils of a single site are not adequate for fully understanding the controls on soil microbial activity across a vast land mass with large variation in

  18. Contributions of dynamic environmental signals during life-cycle transitions to early life-history traits in lodgepole pine (Pinus contorta Dougl.)

    Science.gov (United States)

    Liu, Yang; Wang, Tongli; El-Kassaby, Yousry A.

    2016-05-01

    Environmental signals are important triggers in the life-cycle transitions and play a crucial role in the life-history evolution. Yet very little is known about the leading ecological factors contributing to the variations of life-history traits in perennial plants. This paper explores both the causes and consequences for the evolution of life-history traits (i.e., seed dormancy and size) in lodgepole pine (Pinus contorta Dougl.) across British Columbia (B.C.), Canada. We selected 83 logepole pine populations covering 22 ecosystem zones of B.C. and through their geographic coordinate, 197 climatic variables were generated accordingly for the reference (1961-1990) and future (2041-2070) periods. We found that dynamic climatic variables rather than constant geographic variables are the true environmental driving forces in seed dormancy and size variations and thus provide reliable predictors in response to global climate change. Evapotranspiration and precipitation in the plant-to-seed chronology are the most critical climate variables for seed dormancy and size variations, respectively. Hence, we predicted that levels of seed dormancy in lodgepole pine would increase across large tracts of B.C. in 2050s. Winter-chilling is able to increase the magnitude of life-history plasticity and lower the bet-hedge strategy in the seed-to-plant transition; however, winter-chilling is likely to be insufficient in the north of 49° N in 2050s, which may delay germination while unfavorable conditions during dry summers may result in adverse consequences in the survival of seedlings owing to extended germination span. These findings provide useful information to studies related to assessments of seed transfer and tree adaptation.

  19. Impact of tumor chronology and tumor biology on lymph node metastasis in breast cancer

    OpenAIRE

    Smeets, Ann; Ryckx, Andries; Belmans, Ann; Wildiers, Hans; Neven, Patrick; Floris, Giuseppe; Schöffski, Patrick; Christiaens, Marie-Rose

    2013-01-01

    Synopsis The significance of nodal metastasis in breast cancer is under discussion. We investigated the impact of variables of tumor chronology and tumor biology on the presence of lymph node metastases. Purpose Lymph node involvement is the main prognostic factor in breast cancer. However, it is under discussion whether nodal metastasis in breast cancer only reflects the chronological age of the tumor or whether it is also a marker of tumor biology. The goal of our study was to investigate t...

  20. Evidence for last interglacial chronology and environmental change from Southern Europe

    OpenAIRE

    Achim Brauer; Allen, J.R.M.; Jens Mingram; Peter Dulski; Sabine Wulf; Huntley, B.

    2007-01-01

    Establishing phase relationships between earth-system components during periods of rapid global change is vital to understanding the underlying processes. It requires records of each component with independent and accurate chronologies. Until now, no continental record extending from the present to the penultimate glacial had such a chronology to our knowledge. Here, we present such a record from the annually laminated sediments of Lago Grande di Monticchio, southern Italy. Using this record ...

  1. A 60 000 year Greenland stratigraphic ice core chronology

    Directory of Open Access Journals (Sweden)

    K. K. Andersen

    2007-11-01

    Full Text Available The Greenland Ice Core Chronology 2005 (GICC05 is a time scale based on annual layer counting of high-resolution records from Greenland ice cores. Whereas the Holocene part of the time scale is based on various records from the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely based on NorthGRIP records. Here we present an 18 kyr extension of the time scale such that GICC05 continuously covers the past 60 kyr. The new section of the time scale places the onset of Greenland Interstadial 12 (GI-12 at 46.9±1.0 kyr b2k (before year AD 2000, the North Atlantic Ash Zone 2 layer in GI-15 at 55.4±1.2 kyr b2k, and the onset of GI-17 at 59.4±1.3 kyr b2k. The error estimates are derived from the accumulated number of uncertain annual layers and can be regarded as 1σ uncertainties. In the 40–60 kyr interval the new time scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 kyr, whereas GICC05 compares well to the dating of the Hulu Cave record with absolute age differences of less than 800 years throughout the 60 kyr period. The new time scale is generally in close agreement with other independently dated records and reference horizons, such as the Laschamp geomagnetic excursion and the Kleegruben speleothem record from the Austrian Alps, suggesting high accuracy of both event durations and absolute age estimates.

  2. A 60 000 year Greenland stratigraphic ice core chronology

    Directory of Open Access Journals (Sweden)

    A. Svensson

    2008-03-01

    Full Text Available The Greenland Ice Core Chronology 2005 (GICC05 is a time scale based on annual layer counting of high-resolution records from Greenland ice cores. Whereas the Holocene part of the time scale is based on various records from the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely based on NorthGRIP records. Here we present an 18 ka extension of the time scale such that GICC05 continuously covers the past 60 ka. The new section of the time scale places the onset of Greenland Interstadial 12 (GI-12 at 46.9±1.0 ka b2k (before year AD 2000, the North Atlantic Ash Zone II layer in GI-15 at 55.4±1.2 ka b2k, and the onset of GI-17 at 59.4±1.3 ka b2k. The error estimates are derived from the accumulated number of uncertain annual layers. In the 40–60 ka interval, the new time scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 ka. Assuming that the Greenland climatic events are synchronous with those seen in the Chinese Hulu Cave speleothem record, GICC05 compares well to the time scale of that record with absolute age differences of less than 800 years throughout the 60 ka period. The new time scale is generally in close agreement with other independently dated records and reference horizons, such as the Laschamp geomagnetic excursion, the French Villars Cave and the Austrian Kleegruben Cave speleothem records, suggesting high accuracy of both event durations and absolute age estimates.

  3. Chronology of Awareness About US National Park External Threats

    Science.gov (United States)

    Shafer, Craig L.

    2012-12-01

    The objective of this paper is to raise understanding of the history of protected area external threat awareness in the United States and at World Protected Area Congresses. The earliest concerns about external threats to US national parks began in the late nineteenth century: a potential railroad transgression of Yellowstone National Park in the 1880s. During the early and mid 1930s, George Wright and colleagues focused on outside boundary concerns like of hunting and trapping of furbearers, grazing, logging, disease and hybridization between species. In the 1960s, a worldwide recognition began about the role of outside habitat fragmentation/isolation on nature reserves and human generated stressors crossing their boundaries. The State of the Park Report 1980 added a plethora of threats: oil/gas and geothermal exploration and development, hydropower and reclamation projects, urban encroachment, roads, resorts, and recreational facilities. The early 1980s ushered in political interference with NPS threats abatement efforts as well as Congressional legislative initiatives to support the abatement challenges of the agency. By 1987, the Government Accounting Office issued its first report on National Park Service (NPS) progress in dealing with external threats. Climate change impacts on parks, especially in terms of animals adjusting their temperature and moisture requirements by latitude and altitude, surfaced in the technical literature by the mid-1980s. By 1992, the world parks community stressed the need to integrate protected areas into the surrounding landscape and human community. The importance of the matrix has gradually gained appreciation in the scientific community. This chronology represents one example of national park and protected areas' institutional history contributing to the breath of modern conservation science.

  4. On the Assimilation of Tree-Ring-Width Chronologies

    Science.gov (United States)

    Acevedo, Walter; Reich, Sebastian; Cubasch, Ulrich

    2015-04-01

    Data assimilation (DA) of climate proxy records is currently acknowledged as a promising approach to the paleoclimate reconstruction problem, with the potential to bring physical consistency to reconstructed fields. Previous paleo-DA studies have typically assumed a linear relationship between climate forcing and the resulting proxy data, whereas there exist growing evidence of complex, potentially non-linear, proxy formation processes. Accordingly, it appears natural to simulate the proxy response to climate in a more realistic fashion, by way of proxy-specific forward models. Following this train of thought, we investigate the assimilation of the most traditional climate proxy type, Tree-Ring-Width (TRW) chronologies, using the process-based tree-ring growth forward model Vaganov-Shashkin-Lite (VSL) and ensemble Kalman filter (EnKF) techniques. Used as observation operator, VSL's formulation implies three compounding, challenging features: (i) time averaging, (ii) "switching recording" of 2 variables and (iii) bounded response windows leading to "thresholded response". DA experiments involving VSL-based pseudo-TRW observations are performed first for a chaotic 2-scale dynamical system, used as a cartoon of the atmosphere-land system, and then for an atmospheric general circulation model of intermediate complexity. Our results reveal that VSL's nonlinearities may considerable deteriorate the performance of EnKF for Time-Averaged (TA) estimation, as compared to the utilization of a TA linear observation operator. Moreover, we show that this assimilation skill loss can be considerably reduced by embedding VSL's formulation into fuzzy logic theory, which fosters new interpretations of tree-ring growth limitation processes.

  5. Isotope chronological trace of granite gravel in Hefei Basin

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The discovery of granite gravel in Hefei Jurassic backland basin, which came from the Dabie Shah or North Huaiyang, has a great significance for probing into uplift and exhumation of the Dabie orogenic belt. Lithochemical and isotope chronological analyses on the granite gravel in the Sanjianpu Formation and the Fenghuangtai Formation in Jinzhai County prove that post-orogenic granite was developed in the major provenance of the Hefei Basin; that is, Dabie Shah or North Huaiyang. Discordant lower intersection point age of zircon U-Pb of granite gravel is 40Ar/39about 214 Ma, and Ar/39Ar age of muscovite about 196 Ma,K-Ar age of K-spar about 181 Ma. The former is the diagenetic age of the sample, and the latter two represent the sealed ages of muscovite and K-spar respectively. The age of sedimentary rocks in which a lot of granite gravels appear in the sedimentary section may represent the newest age of the exhumation of the granite body, so we assume that the age is 166 Ma. Therefore, we calculated the uplift rates of the granite body from Late Triassic to early Middle Jurassic; that is about 0.08 km/Ma and 0.4-0.3 km/Ma in the early slowly uplifting stage and later fast uplifting stage respectively, after the formation of the body at 214 Ma. These results are basically identical to the uplifting ages of the Dabie ultrahigh pressure metamorphic (UHPM) belt and the North Huaiyang thrust belt.

  6. Application of Bomb Radiocarbon Chronologies to Shortfin Mako (Isurus oxyrinchus)

    Energy Technology Data Exchange (ETDEWEB)

    Ardizzone, D; Cailliet, G M; Natanson, L J; Andrews, A H; Kerr, L A; Brown, T A

    2007-07-16

    and the number of samples for MIA analysis was insufficient for some months. Hence, unequivocal validation of shortfin mako age estimates has yet to be accomplished. Atmospheric testing of thermonuclear devices in the 1950s and 1960s effectively doubled the natural atmospheric radiocarbon ({sup 14}C). The elevated {sup 14}C levels were first recorded in 1957-58, with a peak around 1963. As a consequence, {sup 14}C entered the ocean through gas exchange with the atmosphere at the ocean surface and in terrestrial runoff. Despite variable oceanographic conditions, a worldwide rise of the bomb {sup 14}C signal entered the ocean mixed layer as dissolved inorganic carbon (DIC) in 1957-58. The large amounts of {sup 14}C released from the bomb tests produced a signature that can be followed through time, throughout the marine food web, and into deeper waters. The marked increase of radiocarbon levels was first measured in the DIC of seawater and in biogenic marine carbonates of hermatypic corals in Florida. Subsequently, this record was documented in corals from other regions and in the thallus of rhodoliths. The accumulation of radiocarbon in the hard parts of most marine organisms in the mixed layer (such as fish otoliths and bivalves) was synchronous with the coral time-series. This technique has been used to validate age estimates and longevity of numerous bony fishes to date, as well as to establish bomb radiocarbon chronologies from different oceans. In the first application of this technique to lamnoid sharks, validated annual band-pair deposition in vertebral growth bands for the porbeagle (Lamna nasus) aged up to 26 years. Radiocarbon values from samples obtained from 15 porbeagle caught in the western North Atlantic Ocean (some of which were known-age) produced a chronology similar in magnitude to the reference carbonate chronology for that region. The observed phase shift of about 3 years was attributed to different sources of carbon between vertebrae and those for

  7. 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.

  8. Power, Governance and Boundary Spanning Leadership in Public Sector Organisations

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2015-01-01

    . The general interest in this workshop, and the study of boundary spanning leadership and power in public organizations, is related to perspectives concerning the extent to which the quality of boundary spanning activities has significant spillover effects on the organization's productivity, job satisfaction......The phenomenon of power and boundary spanning leadership in public sector organizations is the topic for the present workshop. In this workshop we present a practice perspective (Corradi, Gherardi and Verzelloni 2010) on the management of power and boundary spanning leadership. We will focus...... on the practice that evolves on the boundaries that span occupational groups, departments and organizations. The workshop takes it’s starting point in an interdisciplinary Scandinavian research project which deals with the question of how power processes can promote, or hinder, boundary spanning leadership...

  9. [Chinese pine tree ring width chronology and its relations to climatic conditions in Qianshan Mountains].

    Science.gov (United States)

    Chen, Zhen-Ju; Sun, Yu; He, Xing-Yuan; Chen, Wei; Shao, Xue-Mei; Zhang, Hua-Yu; Wang, Zhong-Yu; Liu, Xiao-Yu

    2007-10-01

    Taking Chinese pine in Qianshan Mountains as a sample, the tree ring width chronology including standard, residual, and Arstan chronologies was established. The results showed that the tree ring width of Chinese pine had a higher correlation with the temperature in May - July and in September - November, and significant positive correlations were observed between the tree ring width and the extreme minimum temperature in July and mean minimum temperature in September. The chronology had significant or very significant correlations with the extreme minimum temperature in December and next January, mean minimum temperature in January, annual precipitation, and the precipitation in April, May and last December. Chinese pine had stronger responses to the monthly/yearly water vapor pressure and relative humidity. The yearly and most monthly evaporation had negative effects on the growth, being most significant for the evaporation in April - July. The narrowed tree rings recorded by the chronology demonstrated the 30 times of extreme drought since 1 800. The growth of Chinese pine in Qianshan Mountains was also affected by the climate changes on global and hemisphere scales. There existed 11-, 23- and 50- year- common periodicity between the chronology and solar activity, and 10-, 20- and 45- year- common periodicity between the chronology and geomagnetic activity. PMID:18163297

  10. Chinese pine tree ring width chronology and its relation to climate conditions in the Qianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    Zhenju CHEN; Yu SUN; Xingyuan HE; Wei CHEN; Xuemei SHAO; Huayu ZHANG; Zhongyu WANG; Xiaoyu LIU

    2008-01-01

    Taking Chinese pine in Qianshan Mountains as a sample, the tree ring width chronology including Standard, Residual, and Arstan chronologies was estab-lished. The results show that the tree ring width of Chinese pine is highly correlated with the temperatures from May to July and from September to November. Statistically significant positive correlations were observed between tree ring width and the extreme minimum temperatures in July and mean minimum temperatures in September. The chronology was significantly or very significantly correlated with extreme minimum temperatures in December and the following January, with mean min-imum temperatures in January, with annual precipita-tion and with precipitation in April, May and the following December. The Chinese pine responded strongly to the monthly/yearly water vapor pressure and relative humidity. Annual and largely monthly evaporation in April-July had a negative effect on tree growth, and was particularly striking for evaporation in April-July. The narrow tree rings recorded by the chro-nology demonstrated the 30 occasions of extreme drought since 1800. The growth of ChineSe pine in the Qianshan mountains were also affected by climate changes on a hemispheric and global scale. There were 11-, 23-and 50-year-common periodicities between the chronology and solar activity and 10-, 20- and 45-year-common periodicit-ies between the chronology and geomagnetic activity.

  11. ESR/U-series chronology of the Lower Palaeolithic palaeo-anthropological site of Visogliano, Trieste, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Falgueres, C.; Bahain, J.J.; Yokoyama, Y. [CNRS, UMR 5198, Museum Natl Hist Nat, Dept Prehist, F-75013 Paris, (France); Tozzi, C.; Boschian, G. [Univ Pisa, Dipartimento Sci Archeol, I-56100 Pisa, (Italy); Dolo, J.M. [CEA Saclay, Lab Natl Henri Becquerel, F-91191 Gif Sur Yvette, (France); Mercier, N.; Valladas, H. [CEA, CNRS, Lab Sci Climat and Environm, F-91198 Gif Sur Yvette, (France)

    2008-07-01

    The Visogliano shelter, in north-eastern Italy, is an important Middle Pleistocene occupation site where human remains were found together with an archaic lithic industry, including choppers, chopping tools and a few proto-bifaces. It is of utmost importance to try to document this period, when a second wave of settlement colonised Western Europe, carrying new flaking techniques and tools. Combined ESR/U-series analyses, integrated with bio-stratigraphical and environmental data, define a chronological frame for the layers from which the artefacts were unearthed. The lower levels, including human remains, can be dated to the 350-500 kyr time span, in agreement with micro-mammal and stratigraphical studies. These data make Visogliano one of the oldest palaeo-anthropological sites in Italy, where human remains are directly associated with proto-bifaces, choppers and chopping tools. In Western Europe, Visogliano is contemporaneous to the G soil of the Arago Cave, France, with which it shares several similarities in faunal assemblages and radiometric data, and which contains human remains also. These data make Visogliano as one of the oldest sites in Europe where the Acheulian culture is observed. (authors)

  12. Improved construction of medium-span concrete viaducts

    OpenAIRE

    Caballero, Ángel; Turmo Coderque, José

    2011-01-01

    Concreting of span by span construction with travelling scaffolding is typically made in two phases. In the first phase, webs and bottom flange of the box girder are concreted. In the second phase, top flange is concreted. Once the cross section is self-supporting, this is to say, once the concrete of the top flange is hardened, the segment can be prestressed and the scaffolding can be shifted to the next span. This procedure takes usually two weeks per span. In order to shorten the critic...

  13. Long span cable supported bridges - present technology and trends

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

    The activity within the field of long-span cable supported bridges has never been larger than at the end of the 20th century. The technology is well advanced to cope with the present challenges but it is also approaching its limits so if the trend towards ever increasing spans continues into the ......The activity within the field of long-span cable supported bridges has never been larger than at the end of the 20th century. The technology is well advanced to cope with the present challenges but it is also approaching its limits so if the trend towards ever increasing spans continues...

  14. A new luminescence dating chronology for the Rhafas cave site (NE Morocco): Insights into Palaeolithic human cultural change under varying palaeoenvironmental conditions in the Maghreb

    Science.gov (United States)

    Dörschner, Nina; Fitzsimmons, Kathryn E.; Ditchfield, Peter; McLaren, Sue J.; Steele, Teresa E.; Zielhofer, Christoph; McPherron, Shannon P.; Bouzouggar, Abdeljalil; Hublin, Jean-Jacques

    2016-04-01

    Archaeological sites in northern Africa provide a rich record that is of increasing importance for current debates relating to the origins of modern human behaviour and to Out of Africa human dispersal events. Particular interest is placed on the cultural transition between the North African Middle Stone Age (MSA) and Late Stone Age (LSA), and the need for accurately defined chronologies, however the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb) and potential correlation with environmental conditions remain poorly understood. The inland cave site of Rhafas (Morocco) preserves a long stratified sequence providing valuable chronological information about cultural changes in the Maghreb spanning the North African MSA through to the Neolithic. In this study, we apply optically stimulated luminescence (OSL) dating on sand-sized quartz grains to the cave deposits of Rhafas as well as to a section on the terrace in front of the cave entrance. Single grain OSL dating reliably constrains the timing of technocomplexes beyond the limits of radiocarbon by directly dating sediment associated with archaeological traces. We combine OSL dating with multi-proxy geological investigations (XRF, grain size analyses, stable isotopes, thin sections) to investigate site formation processes and reconstruct palaeoenvironmental conditions during human occupation phases at Rhafas. Our results indicate that the occupation of the site started at least in MIS 6 during a phase of relatively arid environmental conditions. Climatic amelioration after c.140 ka is associated with a change in sediment geochemistry at the site, most likely linked to a change in sediment source due to shifting wind directions. Tanged pieces - typical for the classical Aterian technocomplex - start to occur in the archaeological sequence in MIS 5, consistent with previously published chronological data from the Maghreb. From 55 ka, climatic conditions were

  15. The Effect of Orthographic Neighborhood in the Reading Span Task

    Science.gov (United States)

    Robert, Christelle; Postal, Virginie; Mathey, Stéphanie

    2015-01-01

    This study aimed at examining whether and to what extent orthographic neighborhood of words influences performance in a working memory span task. Twenty-five participants performed a reading span task in which final words to be memorized had either no higher frequency orthographic neighbor or at least one. In both neighborhood conditions, each…

  16. C-Span in the Classroom. Teacher's Guide.

    Science.gov (United States)

    Carey, Helen H.; Greenberg, Judith E.

    This teacher's guide is designed to show how Cable-Satellite Public Affairs Network (C-SPAN) can be used as a primary source in the secondary education classroom to teach citizenship education for concept and skill development. Subject areas that C-SPAN can supplement are global education, government, public speaking, economics education, law…

  17. Community Engagement and Boundary-Spanning Roles at Research Universities

    Science.gov (United States)

    Weerts, David J.; Sandmann, Lorilee R.

    2010-01-01

    Over the past decade, community engagement has emerged as an important priority among many colleges and universities. This study employs a multi-case study design to examine boundary spanning practices of research universities that have adopted a community engagement agenda. A model is advanced to conceptualize spanning behaviors and to inform…

  18. 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.

  19. Fuzzy α-minimum spanning tree problem: definition and solutions

    Science.gov (United States)

    Zhou, Jian; Chen, Lu; Wang, Ke; Yang, Fan

    2016-04-01

    In this paper, the minimum spanning tree problem is investigated on the graph with fuzzy edge weights. The notion of fuzzy ? -minimum spanning tree is presented based on the credibility measure, and then the solutions of the fuzzy ? -minimum spanning tree problem are discussed under different assumptions. First, we respectively, assume that all the edge weights are triangular fuzzy numbers and trapezoidal fuzzy numbers and prove that the fuzzy ? -minimum spanning tree problem can be transformed to a classical problem on a crisp graph in these two cases, which can be solved by classical algorithms such as the Kruskal algorithm and the Prim algorithm in polynomial time. Subsequently, as for the case that the edge weights are general fuzzy numbers, a fuzzy simulation-based genetic algorithm using Prüfer number representation is designed for solving the fuzzy ? -minimum spanning tree problem. Some numerical examples are also provided for illustrating the effectiveness of the proposed solutions.

  20. A two year randomized controlled trial of human caloric restriction: feasibility and effects on predictors of health span and longevity

    Science.gov (United States)

    Background: Caloric restriction (CR), energy intake reduced below ad libitum (AL) intake, increases life span in many species. The implications for humans can be clarified by randomized controlled trials of CR. Methods: To determine CRs feasibility, safety, and effects on predictors of longevity, di...

  1. MULTIGENERATIONLIFE-SPAN TESTS OF THE NUTRITIONAL ADEQUACY OF SEVERAL DIETS AND CULTURE WATERS FOR CERIODAPHNIA DUBIA

    Science.gov (United States)

    The effects of four diets [Chlamydomonas reinhardtii, Selenastrum capricornutum, yeast-trout chow-Cerophyl (YTC) and YTC plus S. capricornutum] and two reconstituted waters on the vitality and fecundity of five to six life-span generations of Ceriodaphnia dubia were determined. T...

  2. Maintenance of cellular ATP level by caloric restriction correlates chronological survival of budding yeast

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon-Seok; Lee, Cheol-Koo, E-mail: cklee2005@korea.ac.kr

    2013-09-13

    Highlights: •CR decreases total ROS and mitochondrial superoxide during the chronological aging. •CR does not affect the levels of oxidative damage on protein and DNA. •CR contributes extension of chronological lifespan by maintenance of ATP level -- Abstract: The free radical theory of aging emphasizes cumulative oxidative damage in the genome and intracellular proteins due to reactive oxygen species (ROS), which is a major cause for aging. Caloric restriction (CR) has been known as a representative treatment that prevents aging; however, its mechanism of action remains elusive. Here, we show that CR extends the chronological lifespan (CLS) of budding yeast by maintaining cellular energy levels. CR reduced the generation of total ROS and mitochondrial superoxide; however, CR did not reduce the oxidative damage in proteins and DNA. Subsequently, calorie-restricted yeast had higher mitochondrial membrane potential (MMP), and it sustained consistent ATP levels during the process of chronological aging. Our results suggest that CR extends the survival of the chronologically aged cells by improving the efficiency of energy metabolism for the maintenance of the ATP level rather than reducing the global oxidative damage of proteins and DNA.

  3. Maintenance of cellular ATP level by caloric restriction correlates chronological survival of budding yeast

    International Nuclear Information System (INIS)

    Highlights: •CR decreases total ROS and mitochondrial superoxide during the chronological aging. •CR does not affect the levels of oxidative damage on protein and DNA. •CR contributes extension of chronological lifespan by maintenance of ATP level -- Abstract: The free radical theory of aging emphasizes cumulative oxidative damage in the genome and intracellular proteins due to reactive oxygen species (ROS), which is a major cause for aging. Caloric restriction (CR) has been known as a representative treatment that prevents aging; however, its mechanism of action remains elusive. Here, we show that CR extends the chronological lifespan (CLS) of budding yeast by maintaining cellular energy levels. CR reduced the generation of total ROS and mitochondrial superoxide; however, CR did not reduce the oxidative damage in proteins and DNA. Subsequently, calorie-restricted yeast had higher mitochondrial membrane potential (MMP), and it sustained consistent ATP levels during the process of chronological aging. Our results suggest that CR extends the survival of the chronologically aged cells by improving the efficiency of energy metabolism for the maintenance of the ATP level rather than reducing the global oxidative damage of proteins and DNA

  4. The chronology of the India-Asia collision

    Science.gov (United States)

    Garzanti, Eduardo; Hu, Xiumian

    2016-04-01

    Markedly diverging interpretations and incompatible scenarios have been proposed for the early stages of the Himalayan Orogeny. One view is that the northern Indian passive margin may have been involved in ophiolite obduction, arc-continent, or continent-continent collision as early as the Late Cretaceous. A different view is that India may have not come into contact with Asia until as late as the Oligo-Miocene. Ages assigned to the India-Asia collision have thus ranged rather freely from as old as 70 Ma to as young as 25-20 Ma, allowing researchers to select in remarkable liberty the age that fitted best with their lines of reasoning. In recent years, however, a growing body of stratigraphic evidence has constrained the chronology of collision with increasing accuracy and precision. Provenance analysis has ruled out early collision or ophiolite-obduction hypotheses, indicating that renewed terrigenous supply in the Maastrichtian to Danian (72-62 Ma) was derived from India in the south - rejuvenated by magmatic upwelling during the Deccan event - rather than from Asia or from an obducting ophiolite in the north (Garzanti and Hu, 2015). Integrated biostratigraphy and detrital-zircon chronostratigraphy has demonstrated that the first continent-continent contact and consequent disappearance of Neotethyan oceanic lithosphere at one point in south Tibet took place in the Selandian (59 ± 1 Ma; DeCelles et al., 2014; Wu et al., 2014; Hu et al., 2015). A major disconformity documenting tectonic uplift of carbonate platforms all along the Tethys Himalaya from the Gamba and Tingri areas of south Tibet to the Zanskar Range of the NW Himalaya, allowed dating the arrival of the orogenic wave in the inner part of the northern Indian passive margin around the Paleocene/Eocene boundary (ca. 56 Ma; Garzanti et al., 1987; Li et al., 2015). Shallow-marine seaways linked with Neotethys persisted in the Himalaya until the mid-Ypresian (ca. 50 Ma), when they were finally filled by

  5. Triatoma sordida: considerações sobre o tempo de vida das formas adultas e sobre a oviposição das fêmeas Triatoma sordida: comments on the life span of the adult forms and oviposition of females

    Directory of Open Access Journals (Sweden)

    José Maria Pacheco de Souza

    1978-09-01

    Full Text Available Foram observados 53 exemplares do T. sordida que chegaram à fase alada, oriundos de 110 ovos; os machos eram em número de 22 e as fêmeas 31. Os tempos médios de duração da fase de ninfa não foram estatisticamente diferentes entre os sexos, sendo 174,6 e 170,6 dias respectivamente para machos e fêmeas. O tempo médio de vida na fase alada foi significativamente maior para as fêmeas, com 503 dias para estas e 284 para os machos. O período de oviposição correspondeu a 86,42% do tempo de fase alada das fêmeas, com a postura tendo maior intensidade na primeira metade desta fase. Cada fêmea pôs em média 570,8 ovos, variando a postura de 0,68 a 1,97 ovos por dia.Fifty three specimen of T. sordida which arrived at the adult stage were studied; there were 22 males and 31 females, all obtained from 110 eggs. The average time duration of life in the nymph phase was not statistically different between sexes, being 174.6 and 170.6 days respectively for mate and female. The females had a larger mean time duration of life as adults (503 days than the males (284 days. During their adult life, 86.42% of the time corresponded to oviposition, the greater intensity of egg-laying ocurring during the first half of the period. The mean number of eggs was 570.8 and the ratio egg/day varied from 0.68 to 1.97.

  6. Study of Semi-Span Model Testing Techniques

    Science.gov (United States)

    Gatlin, Gregory M.; McGhee, Robert J.

    1996-01-01

    An investigation has been conducted in the NASA Langley 14- by 22-Foot Subsonic Tunnel in order to further the development of semi-span testing capabilities. A twin engine, energy efficient transport (EET) model with a four-element wing in a takeoff configuration was used for this investigation. Initially a full span configuration was tested and force and moment data, wing and fuselage surface pressure data, and fuselage boundary layer measurements were obtained as a baseline data set. The semi-span configurations were then mounted on the wind tunnel floor, and the effects of fuselage standoff height and shape as well as the effects of the tunnel floor boundary layer height were investigated. The effectiveness of tangential blowing at the standoff/floor juncture as an active boundary-layer control technique was also studied. Results indicate that the semi-span configuration was more sensitive to variations in standoff height than to variations in floor boundary layer height. A standoff height equivalent to 30 percent of the fuselage radius resulted in better correlation with full span data than no standoff or the larger standoff configurations investigated. Undercut standoff leading edges or the use of tangential blowing in the standoff/ floor juncture improved correlation of semi-span data with full span data in the region of maximum lift coefficient.

  7. Research development of digital maintenance and management system for long-span cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    REN Yuan; HUANG Qiao; SUN Yong-ming

    2009-01-01

    Digital cable-stayed bridge maintenance and management system (DCBMS) was developed for the need of maintenance and management of long-span cable-stayed bridges. In this paper, the major functions and theoretical application of eight modules were systematically stated with the background of Harbin Songhua River cable-stayed bridge, which include data management module, inspection and measurement module, assessment module, finite element analysis module, disease diagnosis and prediction module, maintenance module, query module and help module. By analyzing and calculating the data from manual inspection database, basic database and health monitoring subsystem, DCBMS can accomplish the functions like life prediction, disease diagnosis, comprehensive assessment, maintenance and management of bridges. Therefore, the maintenance and management of long-span cable-stayed bridges can be made digital, professional and scientific. By running this system, a real-time and specific technical guidance can be provided for the maintainers and managers of longspan cable-stayed bridges.

  8. The maximum weight spanning star forest problem on cactus graphs

    OpenAIRE

    Nguyen, Viet Hung

    2015-01-01

    International audience A star is a graph in which some node is incident with every edge of the graph, i.e., a graph of diameter at most 2. A star forest is a graph in which each connected component is a star. Given a connected graph G in which the edges may be weighted positively. A spanning star forest of G is a subgraph of G which is a star forest spanning the nodes of G. The size of a spanning star forest F of G is defined to be the number of edges of F if G is unweighted and the total ...

  9. Dutch life expectancy from an international perspective

    NARCIS (Netherlands)

    van Bodegom, D.; Bonneux, L.G.A.; Engelaer, F.M.; Lindenberg, J.; Meij, J.J.; Westendorp, R.G.J.

    2010-01-01

    In general, longer life spans go with longer lives with good quality. Abstention from smoking is an obvious target to get more out of our lives. The ability to better manage chronic diseases is a first step of progress. Life expectancy, disability and quality of life are distinct concepts and may ha

  10. TimeSpan: Using Visualization to Explore Temporal Multi-dimensional Data of Stroke Patients.

    Science.gov (United States)

    Loorak, Mona Hosseinkhani; Perin, Charles; Kamal, Noreen; Hill, Michael; Carpendale, Sheelagh

    2016-01-01

    We present TimeSpan, an exploratory visualization tool designed to gain a better understanding of the temporal aspects of the stroke treatment process. Working with stroke experts, we seek to provide a tool to help improve outcomes for stroke victims. Time is of critical importance in the treatment of acute ischemic stroke patients. Every minute that the artery stays blocked, an estimated 1.9 million neurons and 12 km of myelinated axons are destroyed. Consequently, there is a critical need for efficiency of stroke treatment processes. Optimizing time to treatment requires a deep understanding of interval times. Stroke health care professionals must analyze the impact of procedures, events, and patient attributes on time-ultimately, to save lives and improve quality of life after stroke. First, we interviewed eight domain experts, and closely collaborated with two of them to inform the design of TimeSpan. We classify the analytical tasks which a visualization tool should support and extract design goals from the interviews and field observations. Based on these tasks and the understanding gained from the collaboration, we designed TimeSpan, a web-based tool for exploring multi-dimensional and temporal stroke data. We describe how TimeSpan incorporates factors from stacked bar graphs, line charts, histograms, and a matrix visualization to create an interactive hybrid view of temporal data. From feedback collected from domain experts in a focus group session, we reflect on the lessons we learned from abstracting the tasks and iteratively designing TimeSpan. PMID:26390482

  11. Progress in the Early Solar System Chronology: A Sketch of an Ever-Changing Landscape

    Science.gov (United States)

    Amelin, Yuri; Yin, Q.-Z.; Krot, A. N.; Bouvier, A.; Wadhwa, M.; Kleine, T.; Nyquist, L. E.

    2011-01-01

    The years since the Workshop on the Chronology of Meteorites and the Early Solar System, are marked with ongoing progress in cosmochronology. Rapid improvements in techniques, discovery of new meteorites unlike any previously known, and findings that what was deemed well established constants are actually variables, will be reflected in an updated review of the solar system chronology we are currently preparing. Along with updating the database of meteorite ages, it will involve development of a set of criteria for evaluation of accuracy and consistency of isotopic dates across the entire range of meteorite classes and isotope chronometer systems. Here we present some ideas on what we think is important in meteorite chronology, and invite the cosmochemistry community to discuss them.

  12. Extinction chronology of the woolly rhinoceros Coelodonta antiquitatis in the context of late Quaternary megafaunal extinctions in northern Eurasia

    Science.gov (United States)

    Stuart, Anthony J.; Lister, Adrian M.

    2012-09-01

    Megafaunal extinctions in northern Eurasia (excluding Mediterranean islands) since the Last Interglacial claimed about 37% of species with body weights >44 kg. Here we review the dating evidence for the timings of these extinctions, which were staggered over tens of millennia. Moreover, individual species disappeared at different times in different geographical areas. For example, cave bear probably disappeared ca. 30.5-28.5 ka, at approximately the onset of GS-3 (beginning of 'LGM'), whereas cave lion survived until the Lateglacial ca 14 ka. Others survived into the Holocene: woolly mammoth until ca 10.7 ka in the New Siberian Islands and ca 4 ka on Wrangel Island, giant deer to at least 7.7 ka in western Siberia and European Russia. It is evident that climatic and vegetational changes had major impacts on species' ranges, and moreover the contrasting chronologies and geographical range contractions are consistent with environmental drivers relating to their differing ecologies. However, the possible role of humans in this process has still to be satisfactorily explored. We present a detailed review of the radiocarbon record and extinction chronology of an exclusively northern Eurasian species, the woolly rhinoceros Coelodonta antiquitatis, an animal adapted to feeding on low-growing herbaceous vegetation and a dry climate with minimal snowfall. During the Last Glacial the overall (time-averaged) range of C. antiquitatis extended across most of northern Eurasia, but the species failed to reach North America. On the basis of 233 ultrafiltered AMS radiocarbon dates, together with 50 others which pass our auditing criteria, we reconstruct a detailed chronology for this species. C. antiquitatis was widespread over most of the time span covered by radiocarbon dating, but from ca 35 ka (calibrated) it apparently contracted towards the east, culminating in its probable extinction ca 14 ka, with the latest dates from north-eastern Siberia. It disappeared from Britain, at

  13. 14C dates from Tel Rehov: Iron-Age chronology, pharaohs, and Hebrew kings.

    Science.gov (United States)

    Bruins, Hendrik J; van der Plicht, Johannes; Mazar, Amihai

    2003-04-11

    Stratified radiocarbon dates provide an independent chronological link between archaeological layers and historical data. The invasion by Pharaoh Shoshenq I (Shishak) is a key historical synchronism, approximately 925 B.C.E., mentioned in both Egyptian inscriptions and the Hebrew Bible. The list of places raided by Shoshenq, mentioned at Karnak (Egypt), includes Rehov (Israel). The site yielded a consistent series of radiocarbon dates from the 12th to 9th century B.C.E. Our results (i) suggest a revised Iron-Age chronology; (ii) date an archaeological stratum to Shoshenq's campaign; (iii) indicate the similarity of "Solomonic" and "Omride" pottery; and (iv) provide correlation with Greece and Cyprus.

  14. USING GENETIC ALGORTIHM TO SOLVE STEINER MINIMUM SPANNING TREE PROBLEM

    Directory of Open Access Journals (Sweden)

    Öznur İŞÇİ

    2006-03-01

    Full Text Available Genetic algorithms (GA are a stochastic research methods, and they produce solutions that are close to optimum or near optimum. In addition to GA's successful application to traveling salesman problem, square designation, allocation, workshop table, preparation of lesson/examination schedules, planning of communication networks, assembling line balanced, minimum spanning tree type many combinatorial optimization problems it would be applicable to make the best comparison in optimization. In this study a Java program is developed to solve Steiner minimum spanning tree problem by genetic algorithm and its performance is examined. According to the tests carried out on the problems that were given before in the literature, results that are close to optimum are obtained in by GA approach that is recommended in this study. For the predetermined points in the study, length and gain are calculated for Steiner minimum spanning tree problem and minimum spanning tree problem.

  15. SOLVING MINIMUM SPANNING TREE PROBLEM WITH DNA COMPUTING

    Institute of Scientific and Technical Information of China (English)

    Liu Xikui; Li Yan; Xu Jin

    2005-01-01

    Molecular programming is applied to minimum spanning problem whose solution requires encoding of real values in DNA strands. A new encoding scheme is proposed for real values that is biologically plausible and has a fixed code length. According to the characteristics of the problem, a DNA algorithm solving the minimum spanning tree problem is given. The effectiveness of the proposed method is verified by simulation. The advantages and disadvantages of this algorithm are discussed.

  16. A Minimum Spanning Tree Representation of Anime Similarities

    OpenAIRE

    Wibowo, Canggih Puspo

    2016-01-01

    In this work, a new way to represent Japanese animation (anime) is presented. We applied a minimum spanning tree to show the relation between anime. The distance between anime is calculated through three similarity measurements, namely crew, score histogram, and topic similarities. Finally the centralities are also computed to reveal the most significance anime. The result shows that the minimum spanning tree can be used to determine the similarity anime. Furthermore, by using centralities ca...

  17. Spanning connectedness and Hamiltonian thickness of graphs and interval graphs

    OpenAIRE

    Li, Peng; Wu, Yaokun

    2015-01-01

    International audience A spanning connectedness property is one which involves the robust existence of a spanning subgraph which is of some special form, say a Hamiltonian cycle in which a sequence of vertices appear in an arbitrarily given ordering, or a Hamiltonian path in the subgraph obtained by deleting any three vertices, or three internally-vertex-disjoint paths with any given endpoints such that the three paths meet every vertex of the graph and cover the edges of an almost arbitra...

  18. Evolution of Shanghai STOCK Market Based on Maximal Spanning Trees

    Science.gov (United States)

    Yang, Chunxia; Shen, Ying; Xia, Bingying

    2013-01-01

    In this paper, using a moving window to scan through every stock price time series over a period from 2 January 2001 to 11 March 2011 and mutual information to measure the statistical interdependence between stock prices, we construct a corresponding weighted network for 501 Shanghai stocks in every given window. Next, we extract its maximal spanning tree and understand the structure variation of Shanghai stock market by analyzing the average path length, the influence of the center node and the p-value for every maximal spanning tree. A further analysis of the structure properties of maximal spanning trees over different periods of Shanghai stock market is carried out. All the obtained results indicate that the periods around 8 August 2005, 17 October 2007 and 25 December 2008 are turning points of Shanghai stock market, at turning points, the topology structure of the maximal spanning tree changes obviously: the degree of separation between nodes increases; the structure becomes looser; the influence of the center node gets smaller, and the degree distribution of the maximal spanning tree is no longer a power-law distribution. Lastly, we give an analysis of the variations of the single-step and multi-step survival ratios for all maximal spanning trees and find that two stocks are closely bonded and hard to be broken in a short term, on the contrary, no pair of stocks remains closely bonded for a long time.

  19. The Role of Covert Retrieval in Working Memory Span Tasks: Evidence from Delayed Recall Tests

    OpenAIRE

    McCabe, David P.

    2008-01-01

    The current study examined delayed recall of items that had been processed during simple and complex span tasks. Three experiments were reported showing that despite more items being recalled initially from a simple span task (i.e., word span) than a complex span task (i.e., operation span), on a delayed recall test more items were recalled that had initially been processed during the complex span task. This delayed recall advantage for items processed during complex span tasks persisted when...

  20. The Catacomb cultures of the North-West Caspian steppe : C-14 chronology, reservoir effect, and paleodiet

    NARCIS (Netherlands)

    Shishlina, N. I.; van der Plicht, J.; Hedges, R. E. M.; Zazovskaya, E. P.; Sevastyanov, V. S.; Chichagova, O. A.

    2007-01-01

    For the Bronze Age Catacomb cultures of the North-West Caspian steppe area in Russia, there is a conflict between the traditional relative archaeological chronology and the chronology based on radiocarbon dates. We show that this conflict can be explained largely by the fact that most dates have bee

  1. The WAIS Divide deep ice core WD2014 chronology - Part 2: Annual-layer counting (0-31 ka BP)

    Science.gov (United States)

    Sigl, Michael; Fudge, Tyler J.; Winstrup, Mai; Cole-Dai, Jihong; Ferris, David; McConnell, Joseph R.; Taylor, Ken C.; Welten, Kees C.; Woodruff, Thomas E.; Adolphi, Florian; Bisiaux, Marion; Brook, Edward J.; Buizert, Christo; Caffee, Marc W.; Dunbar, Nelia W.; Edwards, Ross; Geng, Lei; Iverson, Nels; Koffman, Bess; Layman, Lawrence; Maselli, Olivia J.; McGwire, Kenneth; Muscheler, Raimund; Nishiizumi, Kunihiko; Pasteris, Daniel R.; Rhodes, Rachael H.; Sowers, Todd A.

    2016-03-01

    We present the WD2014 chronology for the upper part (0-2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core. The chronology is based on counting of annual layers observed in the chemical, dust and electrical conductivity records. These layers are caused by seasonal changes in the source, transport, and deposition of aerosols. The measurements were interpreted manually and with the aid of two automated methods. We validated the chronology by comparing to two high-accuracy, absolutely dated chronologies. For the Holocene, the cosmogenic isotope records of 10Be from WAIS Divide and 14C for IntCal13 demonstrated that WD2014 was consistently accurate to better than 0.5 % of the age. For the glacial period, comparisons to the Hulu Cave chronology demonstrated that WD2014 had an accuracy of better than 1 % of the age at three abrupt climate change events between 27 and 31 ka. WD2014 has consistently younger ages than Greenland ice core chronologies during most of the Holocene. For the Younger Dryas-Preboreal transition (11.595 ka; 24 years younger) and the Bølling-Allerød Warming (14.621 ka; 7 years younger), WD2014 ages are within the combined uncertainties of the timescales. Given its high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere, with synchronization to other chronologies feasible using high-quality proxies of volcanism, solar activity, atmospheric mineral dust, and atmospheric methane concentrations.

  2. Tree-Ring Chronology of Pedunculate Oak (Quercus robur and its Potential for Development of Dendrochronological Research in Croatia

    Directory of Open Access Journals (Sweden)

    Katarina Čufar

    2014-06-01

    Full Text Available We present the local tree-ring chronology of pedunculate oak (Qercus robur from Kobiljak near Zagreb, Croatia (16º09’ E, 45º49’ N, 140 m a.s.l.. The chronology is based on 17 trees and is 127 years long and covers the period of 1883-2009. The well replicated part of the residual version of the ARSTAN chronology with SSS>0.80 (interval of 88 years, period 1922-2009 was used for dendroclimatological analysis, which showed that June precipitation has positive and temperature has negative effect on tree-ring variation. Comparison with 40 available oak chronologies from the surrounding countries confi rmed its good teleconnection with 2 local oak chronologies from Austria, 2 from Hungary, and 3 from Slovenia. It also exhibits good heteroconnection, i.e. similarity with chronologies of beech (Fagus sylvatica, from various sites in Slovenia. The similarities can be ascribed to response to common climatic factors. The results indicate that the chronology could be a good reference point for constructing a longer regional chronology in Croatia and surrounding countries, which could be used for different purposes including dating of objects of cultural heritage.

  3. Chronological and subjective age differences in flourishing mental health and major depressive episode.

    NARCIS (Netherlands)

    Keyes, C.L.M.; Westerhof, G.J.

    2012-01-01

    Mental health is more than the absence of psychopathology, but few studies use positive mental health along with a measure of past year major depressive episode (MDE). This study addresses this gap by investigating the association of MDE and flourishing mental health (FMH) with chronological age and

  4. Third-molar development in relation to chronologic age in young adults of central China.

    Science.gov (United States)

    Bai, Yuming; Mao, Jing; Zhu, Shengrong; Wei, Wei

    2008-08-01

    The estimation of chronologic age based on the stages of third-molar development was evaluated by using the eight stages (A-H) method of Demirjian and the third-molar development was compared, in terms of sex and age, with results of previous studies. The samples consisted of 291 orthopantomograms from young Chinese subjects of known chronologic age and sex (including 139 males with a mean age of 14.67+/-3.62 y and 152 females with a mean age of 14.85+/-3.70 y). Statistical analysis was performed by employing the Mann-Whitney U-test and the t-test. Regression analysis was conducted to obtain regression formulas for calculating dental age from the chronologic age. Our results showed statistically significant differences (Pthird-molar development between males and females, at the calcification stages D, E and H. And a strong correlation was found between age and third-molar development in both males (r (2)=0.65) and females (r (2)=0.61). New equations (Age=8.76+1.32 Development stage) for estimating chronologic age were derived. It is concluded that third-molar genesis took place earlier in males than in females. The use of third molars as a developmental marker is appropriate in young adults of Central China. The formula obtained in the present study can be used as a guide for estimation of dental maturity and a standard for age estimation for young adults of Central China.

  5. The absolute chronology and thermal processing of solids in the solar protoplanetary disk

    DEFF Research Database (Denmark)

    Connelly, James Norman; Bizzarro, Martin; Krot, Alexander N.;

    2012-01-01

    Transient heating events that formed calcium-aluminum - rich inclusions (CAIs) and chondrules are fundamental processes in the evolution of the solar protoplanetary disk, but their chronology is not understood. Using U-corrected Pb-Pb dating, we determined absolute ages of individual CAIs...

  6. Legal Recognition of Same-Sex Couples in the Countries of the World : a Chronological Overview

    NARCIS (Netherlands)

    Waaldijk, C.; Marsh, V.

    2011-01-01

    Chronological overview of countries (and parts of countries) that have taken some major steps in legally recognising same-sex couples: legal recognition of non-registered same-sex cohabitation, introduction of a form of registered partnership, opening up of adoption and/or marriage for same-sex part

  7. The double-body glyphs and palaeographic chronology in the rongorongo script

    DEFF Research Database (Denmark)

    Wieczorek, Rafal

    2011-01-01

    . A reading of the related literature shows more scribal differences in other rongorongo glyphs as well. By combining various scribal differences together with the analysis of hollow-belly and 099/522 glyphs, most of the existing rongorongo inscriptions can be classified into a chronological list of texts...

  8. Current issues in late Middle Palaeolithic chronology : New assessments from Northern Iberia

    NARCIS (Netherlands)

    Maroto, Julia; Vaquero, Manuel; Arrizabalaga, Alvaro; Baena, Javier; Baquedano, Enrique; Jorda, Jesus; Julia, Ramon; Montes, Ramon; Van Der Plicht, Johannes; Rasines, Pedro; Wood, Rachel

    2012-01-01

    The Iberian Peninsula plays a central role in the current debates on the Middle-Upper Palaeolithic transition and the Neanderthal extinction. This is largely due to the chronological data which some authors have suggested show a clear divide between Northern Iberia, where the Upper Palaeolithic appe

  9. Legal Recognition of Same-Sex Couples in the Countries of the World: a Chronological Overview

    OpenAIRE

    Waaldijk, C.; Marsh, V

    2011-01-01

    Chronological overview of countries (and parts of countries) that have taken some major steps in legally recognising same-sex couples: legal recognition of non-registered same-sex cohabitation, introduction of a form of registered partnership, opening up of adoption and/or marriage for same-sex partners.

  10. The epigenetic clock and telomere length are independently associated with chronological age and mortality

    Science.gov (United States)

    Marioni, Riccardo E; Harris, Sarah E; Shah, Sonia; McRae, Allan F; von Zglinicki, Thomas; Martin-Ruiz, Carmen; Wray, Naomi R; Visscher, Peter M; Deary, Ian J

    2016-01-01

    Background: Telomere length and DNA methylation have been proposed as biological clock measures that track chronological age. Whether they change in tandem, or contribute independently to the prediction of chronological age, is not known. Methods: We address these points using data from two Scottish cohorts: the Lothian Birth Cohorts of 1921 (LBC1921) and 1936 (LBC1936). Telomere length and epigenetic clock estimates from DNA methylation were measured in 920 LBC1936 participants (ages 70, 73 and 76 years) and in 414 LBC1921 participants (ages 79, 87 and 90 years). Results: The epigenetic clock changed over time at roughly the same rate as chronological age in both cohorts. Telomere length decreased at 48–67 base pairs per year on average. Weak, non-significant correlations were found between epigenetic clock estimates and telomere length. Telomere length explained 6.6% of the variance in age in LBC1921, the epigenetic clock explained 10.0%, and combined they explained 17.3% (all P epigenetic age was linked to a 22% increased mortality risk (P = 2.6 × 10−4) whereas, in the same model, a one standard deviation increase in baseline telomere length was independently linked to an 11% decreased mortality risk (P = 0.06). Conclusions: These results suggest that telomere length and epigenetic clock estimates are independent predictors of chronological age and mortality risk. PMID:27075770

  11. The significance of peroxisome function in chronological aging of Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Lefevre, Sophie D.; van Roermund, Carlo W.; Wanders, Ronald J. A.; Veenhuis, Marten; van der Klei, Ida J.

    2013-01-01

    Summary We studied the chronological lifespan of glucose-grown Saccharomyces cerevisiae in relation to the function of intact peroxisomes. We analyzed four different peroxisome-deficient (pex) phenotypes. These included Delta pex3 cells that lack peroxisomal membranes and in which all peroxisomal pr

  12. Niobium-Zirconium Systematics of Meteoritic Rutiles: Application to the Chronology of Mesosiderites

    Science.gov (United States)

    Haba, M. K.; Lai, Y.-J.; Yamaguchi, A.; Schönbächler, M.

    2016-08-01

    Nb-Zr systematics of rutiles from mesosiderites was obtained using MC-ICPMS. Our data show an initial 92Nb/93Nb ratio of ~10-5 in the mesosiderite formation region and provide chronological constraint on the early evolution of the parent body.

  13. The effects of chronological age and size on toxicity of zinc to juvenile brown trout

    Science.gov (United States)

    A series of toxicity tests were conducted to investigate the role of chronological age and organism weight on zinc tolerance in juvenile brown trout (Salmo trutta). Four different incubation temperatures were used to control the maturation of the juveniles prior to zinc exposure...

  14. Quantitative and qualitative approaches to identifying migration chronology in a continental migrant.

    Directory of Open Access Journals (Sweden)

    William S Beatty

    Full Text Available The degree to which extrinsic factors influence migration chronology in North American waterfowl has not been quantified, particularly for dabbling ducks. Previous studies have examined waterfowl migration using various methods, however, quantitative approaches to define avian migration chronology over broad spatio-temporal scales are limited, and the implications for using different approaches have not been assessed. We used movement data from 19 female adult mallards (Anas platyrhynchos equipped with solar-powered global positioning system satellite transmitters to evaluate two individual level approaches for quantifying migration chronology. The first approach defined migration based on individual movements among geopolitical boundaries (state, provincial, international, whereas the second method modeled net displacement as a function of time using nonlinear models. Differences in migration chronologies identified by each of the approaches were examined with analysis of variance. The geopolitical method identified mean autumn migration midpoints at 15 November 2010 and 13 November 2011, whereas the net displacement method identified midpoints at 15 November 2010 and 14 November 2011. The mean midpoints for spring migration were 3 April 2011 and 20 March 2012 using the geopolitical method and 31 March 2011 and 22 March 2012 using the net displacement method. The duration, initiation date, midpoint, and termination date for both autumn and spring migration did not differ between the two individual level approaches. Although we did not detect differences in migration parameters between the different approaches, the net displacement metric offers broad potential to address questions in movement ecology for migrating species. Ultimately, an objective definition of migration chronology will allow researchers to obtain a comprehensive understanding of the extrinsic factors that drive migration at the individual and population levels. As a result

  15. Quantitative and qualitative approaches to identifying migration chronology in a continental migrant

    Science.gov (United States)

    Beatty, William S.; Kesler, Dylan C.; Webb, Elisabeth B.; Raedeke, Andrew H.; Naylor, Luke W.; Humburg, Dale D.

    2013-01-01

    The degree to which extrinsic factors influence migration chronology in North American waterfowl has not been quantified, particularly for dabbling ducks. Previous studies have examined waterfowl migration using various methods, however, quantitative approaches to define avian migration chronology over broad spatio-temporal scales are limited, and the implications for using different approaches have not been assessed. We used movement data from 19 female adult mallards (Anas platyrhynchos) equipped with solar-powered global positioning system satellite transmitters to evaluate two individual level approaches for quantifying migration chronology. The first approach defined migration based on individual movements among geopolitical boundaries (state, provincial, international), whereas the second method modeled net displacement as a function of time using nonlinear models. Differences in migration chronologies identified by each of the approaches were examined with analysis of variance. The geopolitical method identified mean autumn migration midpoints at 15 November 2010 and 13 November 2011, whereas the net displacement method identified midpoints at 15 November 2010 and 14 November 2011. The mean midpoints for spring migration were 3 April 2011 and 20 March 2012 using the geopolitical method and 31 March 2011 and 22 March 2012 using the net displacement method. The duration, initiation date, midpoint, and termination date for both autumn and spring migration did not differ between the two individual level approaches. Although we did not detect differences in migration parameters between the different approaches, the net displacement metric offers broad potential to address questions in movement ecology for migrating species. Ultimately, an objective definition of migration chronology will allow researchers to obtain a comprehensive understanding of the extrinsic factors that drive migration at the individual and population levels. As a result, targeted

  16. Burnup span sensitivity analysis of different burnup coupling schemes

    International Nuclear Information System (INIS)

    Highlights: ► The objective of this work is the burnup span sensitivity analysis of different coupling schemes. ► Three kinds of schemes have been implemented in a new MCNP–ORIGEN linkage program. ► Two kinds of schemes are based predictor–corrector technique and the third is based on Euler explicit method. ► The analysis showed that the predictor–corrector approach better accounts for nonlinear behavior of burnup. ► It is sufficiently good to use the Euler method at small spans but for large spans use of second order scheme is mandatory. - Abstract: The analysis of core composition changes is complicated by the fact that the time and spatial variations in isotopic composition depend on the neutron flux distribution and vice versa. Fortunately, changes in core composition occur relatively slowly and hence the burnup analysis can be performed by dividing the burnup period into some burnup spans and assuming that the averaged flux and cross sections are constant during each burn up span. The burnup span sensitivity analysis attempts to find how much the burnup spans could be increased without any significant change in results. This goal has been achieved by developing a new MCNP–ORIGEN linkage program named MOBC (MCNP–ORIGEN Burnup Calculation). Three kinds of coupling scheme have been implemented in MOBC. Two of these are based on second order predictor–corrector technique and enable us to choose larger time steps, whilst the third one is based on Euler explicit first order method and is faster than the other two. The validity of the developed program has been evaluated by the code vs. code comparison technique. Two different types of codes are employed. The first one is based on deterministic two dimensional transport method, like CASMO-4 and HELIOS codes, and the second one is based on Monte Carlo method, like MCODE code. Only one coupling technique is employed in each of these state of the art codes, while the MOBC excels in its ability to

  17. The Role of Covert Retrieval in Working Memory Span Tasks: Evidence from Delayed Recall Tests

    Science.gov (United States)

    McCabe, David P.

    2008-01-01

    The current study examined delayed recall of items that had been processed during simple and complex span tasks. Three experiments were reported showing that despite more items being recalled initially from a simple span task (i.e., word span) than a complex span task (i.e., operation span), on a delayed recall test more items were recalled that…

  18. Design and operational considerations for unsupported offshore pipeline spans

    Energy Technology Data Exchange (ETDEWEB)

    Shah, B.C.; White, C.N.; Rippon, I.J.

    1988-05-01

    Design and operational considerations have been examined in determining the significance of unsupported offshore pipeline spans that may develop during pipeline installation or field operation. Allowable unsupported span lengths determined during design are generally based on strict code compliance and a design foundation encompassing the worst possible environmental and operational loads. During operation, however, unsupported spans develop beyond the allowable limits, perhaps as a result of various unforseen local conditions. Applying original design criteria is likely to result in cost-prohibitive repair predictions, while lack of action may result in loss of production. Without the design code requirements of an existing or a proposed pipeline system being violated, realistically safe design can be approached through evaluation of the sensitivity of the key design parameters. Priorities for remedial repair of the unsupported spans can be established for the pipelines in service while operating constraints, budget, and schedule are recognized. On the basis of periodic surveys, properly formatted survey data, and reanalysis of the design parameters, pipeline span repair cost estimates and schedules can be appreciably reduced. Similar principles can be applied to a pipeline in planning and design stages to ensure a safe operating design and to eliminate an uneconomically conservative design. These design and operational considerations are illustrated through a case study.

  19. Planetary Environments and Origins of Life

    Directory of Open Access Journals (Sweden)

    Ollivier Marc

    2014-02-01

    Full Text Available The present strategies proposed for the search for the origins of life and for extra-terrestrial life are mainly based on Earth-life and its adaptation along geological eras to the Earth environment. These strategies should however face the difficulty that one cannot as yet accurately date the appearance of life on Earth, and consequently one cannot identify a chronology of phenomena related to the transition from the non-living to the living and the dependence of these phenomena on the Earth environment. In this paper, we present new approaches to search for the origins of life on the Earth and next, for life on exoplanets. This study is based on our experience gained at the head of the CNRSc interdisciplinary research initiative "Environnements Planétaires et Origines de la Vie (EPOVd, and on the analysis of the projects the initiative funded.

  20. POSTMENOPAUSAL BLEEDING: HISTOPATHOLOGICAL SPECTRUM AND ASSOCIATION WITH AGE AND CLEAR SPAN: CASE SERIES OF 328 CASES

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    Ruchita

    2014-06-01

    Full Text Available : Introduction: Postmenopausal bleeding is defined as vaginal bleeding occurring after twelve months of amenorrhea in a woman of the age where the menopause can be expected. With increase in life expectancy, a larger proportion of female population will be in postmenopausal age group; hence, the incidence of postmenopausal bleeding is expected to increase. AIM: We studied the prevalence of malignancy as well as the histopathological spectrum of genital tract lesions in cases of postmenopausal bleeding. The association between age, period between cessation of menses and onset of bleeding per vaginum (clear span was also studied. RESULTS: Malignant causes were more common (58.5% than benign causes and included cervical carcinoma, malignant uterine tumors (13.1%, carcinoma vagina (4.3%, malignant ovarian tumors (5.5%, carcinoma vulva (0.9% and carcinoma fallopian tube (0.3%. Squamous cell carcinoma was the commonest among cervical malignancies. The benign causes included polyps (16.5%, endometrial hyperplasia (4.9%, adenomyosis (2.7%, atrophic endometrium (2.4%, cervicitis (2.1%, leiomyoma (1.8%, proliferative endometrium (1.5%, endometritis (1.5%, secretory endometrium (1.2%, retained IUCD (0.9% and uterovaginal prolapse (0.6%. The likelihood of malignancy increased significantly with advancing age (p-value 0.042. The clear span of cases with malignant tumors was significantly longer than the clear span of cases with benign lesions. Hence, the likelihood of malignancy increased with length of clear span (p-value 0.00809. CONCLUSION: Any postmenopausal patient with vaginal bleeding needs to be investigated thoroughly to determine the cause of the bleeding and should be considered to have abnormal histopathology until proved otherwise