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Sample records for included chronological age

  1. Some Metabolites Act as Second Messengers in Yeast Chronological Aging

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    Karamat Mohammad

    2018-03-01

    Full Text Available The concentrations of some key metabolic intermediates play essential roles in regulating the longevity of the chronologically aging yeast Saccharomyces cerevisiae. These key metabolites are detected by certain ligand-specific protein sensors that respond to concentration changes of the key metabolites by altering the efficiencies of longevity-defining cellular processes. The concentrations of the key metabolites that affect yeast chronological aging are controlled spatially and temporally. Here, we analyze mechanisms through which the spatiotemporal dynamics of changes in the concentrations of the key metabolites influence yeast chronological lifespan. Our analysis indicates that a distinct set of metabolites can act as second messengers that define the pace of yeast chronological aging. Molecules that can operate both as intermediates of yeast metabolism and as second messengers of yeast chronological aging include reduced nicotinamide adenine dinucleotide phosphate (NADPH, glycerol, trehalose, hydrogen peroxide, amino acids, sphingolipids, spermidine, hydrogen sulfide, acetic acid, ethanol, free fatty acids, and diacylglycerol. We discuss several properties that these second messengers of yeast chronological aging have in common with second messengers of signal transduction. We outline how these second messengers of yeast chronological aging elicit changes in cell functionality and viability in response to changes in the nutrient, energy, stress, and proliferation status of the cell.

  2. Reliability of panoramic radiography in chronological age estimation

    OpenAIRE

    Makkad, Ramanpal Singh; Balani, Abhishek; Chaturvedi, Shailendra Singh; Tanwani, Tushar; Agrawal, Anil; Hamdani, Shaheen

    2013-01-01

    Introduction: There has been a strong relationship between the growth rate of bone and teeth, which can be utilized for the purpose of age identification of an individual. Aims and Objective: The present study was designed to determine the relationship between the dental age, the age from dental panoramic radiography, skeletal age, and chronological age. Materials and Methods: The study included 270 individuals, averaging between 17 years and 25 years of age from out-patient department of New...

  3. [Chronological age estimation based on dental panoramic radiography].

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    Tóth, Zsuzsanna Olga; Udvar, Orsolya; Angyal, János

    2014-09-01

    Determination of the dental age is a valuable tool in planning of orthodontic treatment and could be used to estimate the chronological age of unidentified human beings. Among the various age estimation methods one of the most accepted one is the Demirjian method, which has already been modified to selected Hungarian population. In this study we have evaluated the association between the dental age determined by panoramic radiography and the chronological age. 199 panoramic radiographs taken from persons between the ages of 2,8 and 20,3 years were selected to the study. The dental ages of persons were estimated either with the Demirjian or the modified Demirjian method adapted to Hungarian population and the results were compared to the chronological ages in selected age groups. Furthermore the angle of the mandible was registered on both sides with an image analysing software. Statistical analysis of data was performed using SPSS software. Our results show that mean values of mandibular angles exhibited a decreasing trend with age. The two age determination methods resulted in different values. Between 3 and 9 years and the age group between 15 and 17,3 years the adapted Hungarian method proved to be more accurate than the Demirjian method. We have established a mathematical function between the two methods. We could conclude that the panoramic radiography based dental age calculation is a reliable method to estimate the chronological age, but the utility of gonial angle has not been proved.

  4. Dental and skeletal maturity- a biological indicator of chronologic age.

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    Rai, Vivek; Saha, Sonali; Yadav, Gunjan; Tripathi, Abhay Mani; Grover, Kavita

    2014-09-01

    Precise evaluation of the developmental stage of a child is not only an integral part of both diagnosis and treatment of paediatric patients; it is also essential in Forensic Medicine and Dentistry. Physiologic age can be estimated by somatic, sexual, skeletal and dental maturity. Investigate the relationship between the dental age (DA) and skeletal age (SA) of children and comparing it with the chronological age (CA). The dental age estimation methods of Schour and Massler (S&M), and Demirjian and Goldstien (D&G) and skeletal assessment methods of Greulich and Pyle (G&P), and Tanner et al., (TW2) were used to analyze the orthopantomograms and hand-wrist radiographs respectively of 150 healthy subjects within the age range of 5-15 y and compared with the Chronological Age. Data collected was statistically analysed using the SPSS version 15.0 STATISTICAL ANALYSIS Software. For all tests p-value of maturation were demonstrated.

  5. Women at Midlife: An Exploration of Chronological Age, Subjective Age, Wellness, and Life Satisfaction

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    Degges-White, Suzanne; Myers, Jane E.

    2006-01-01

    Women (N = 224) between 35 and 65 years old participated in a study that examined the relationship among chronological age, subjective age, wellness, and life satisfaction. Women whose subjective age was less than or equal to their chronological age reported greater wellness; total wellness was a significant predictor of life satisfaction.…

  6. Iron Age Mediterranean Chronology : A Reply

    NARCIS (Netherlands)

    Bruins, Hendrik J.; Nijboer, Albert J.; van der Plicht, Johannes

    2011-01-01

    This article is a reply to the preceding rejoinder by Fantalkin et al., which they wrote in response to our article concerning radiocarbon dates of Iron Age sites in the Mediterranean region measured at Groningen (van der Plicht et al. 2009). We do not agree with much of their criticism. Our reply

  7. Nutritional Control of Chronological Aging and Heterochromatin in Saccharomyces cerevisiae

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    McCleary, David F.; Rine, Jasper

    2017-01-01

    Calorie restriction extends life span in organisms as diverse as yeast and mammals through incompletely understood mechanisms.The role of NAD+-dependent deacetylases known as Sirtuins in this process, particularly in the yeast Saccharomyces cerevisiae, is controversial. We measured chronological life span of wild-type and sir2Δ strains over a higher glucose range than typically used for studying yeast calorie restriction. sir2Δ extended life span in high glucose complete minimal medium and had little effect in low glucose medium, revealing a partial role for Sir2 in the calorie-restriction response under these conditions. Experiments performed on cells grown in rich medium with a newly developed genetic strategy revealed that sir2Δ shortened life span in low glucose while having little effect in high glucose, again revealing a partial role for Sir2. In complete minimal media, Sir2 shortened life span as glucose levels increased; whereas in rich media, Sir2 extended life span as glucose levels decreased. Using a genetic strategy to measure the strength of gene silencing at HML, we determined increasing glucose stabilized Sir2-based silencing during growth on complete minimal media. Conversely, increasing glucose destabilized Sir-based silencing during growth on rich media, specifically during late cell divisions. In rich medium, silencing was far less stable in high glucose than in low glucose during stationary phase. Therefore, Sir2 was involved in a response to nutrient cues including glucose that regulates chronological aging, possibly through Sir2-dependent modification of chromatin or deacetylation of a nonhistone protein. PMID:28064165

  8. Using Dental Age to Estimate Chronological Age in Czech Children Aged 3–18 Years

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    Kristina Ginzelová

    2015-01-01

    Full Text Available The Demirjian methods to determine dental age are based on analysis of orthopantograms. The dental age estimation is based on establishing the tooth development stages. The purpose of this study was to assess the accuracy of estimation of dental age by Demirjian in the use of all of his four methods. 505 Czech healthy boys and girls aged 3 to 18 years were examined radiographically at the Department of Stomatology, Second Faculty of Medicine, Charles University in Prague. It was mentioned the factors of underlying diseases influence the accuracy of the dental age estimation. For statistical evaluation, descriptive statistics was used to compare deviations of the mean values of chronological and dental age in each age group. The resulting difference between dental age and chronological age is not significant in both genders only when using both Demirjian 7-teeth methods of 1973 and 1976. Therefore these may be most appropriately used for forensic age estimation. There are shown standard deviation differences in different countries. Demirjian’s original 7-teeth method from 1973 and Demirjian’s revised 4-teeth method from 1976 appear to be the best methods for calculating the dental age of healthy Czech children of both genders.

  9. Effect of Orally Administered Collagen Peptides from Bovine Bone on Skin Aging in Chronologically Aged Mice

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    Hongdong Song

    2017-11-01

    Full Text Available Collagen peptides (CPs have demonstrated to exert beneficial effects on skin photoaging. However, little has been done to evaluate their effects on chronologically aged skin. Here, the effects of CPs from bovine bone on skin aging were investigated in chronologically aged mice. 13-month-old female Kunming mice were administered with CPs from bovine bone (200, 400 and 800 mg/kg body weight/day or proline (400 mg/kg body weight/day for 8 weeks. Mice body weight, spleen index (SI and thymus index (TI, degree of skin laxity (DSL, skin components, skin histology and antioxidant indicators were analyzed. Ingestion of CPs or proline had no effect on mice skin moisture and hyaluronic acid content, but it significantly improved the skin laxity, repaired collagen fibers, increased collagen content and normalized the ratio of type I to type III collagen in chronologically aged skin. CPs prepared by Alcalase performed better than CPs prepared by collagenase. Furthermore, CPs intake also significantly improved the antioxidative enzyme activities in skin. These results indicate that oral administration of CPs from bovine bone or proline can improve the laxity of chronologically aged skin by changing skin collagen quantitatively and qualitatively, and highlight their potential application as functional foods to combat skin aging in chronologically aged process.

  10. Age Identity and Elderly Disclosure of Chronological Age.

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    Coupland, Nikolas; Coupland, Justine

    A study examined the discourse sequences and routines through which older adults disclose their ages to others. Data are drawn from conversations between women, who were asked to "get to know each other," and interviews with 34 women and 6 men in an elderly day care center. The second source group was used only to support the distribution evidence…

  11. Assessing chronological age of unaccompanied minors in southern Italy.

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    Nuzzolese, Emilio; Solarino, Biagio; Liuzzi, Claudia; Di Vella, Giancarlo

    2011-09-01

    The increasing volume of, and subsequent complexities resulting from, migratory flows in the broader context of globalization has led to a range of problems, not only the protection of human rights and disease control but also the identification of those with the right to apply for refugee status and the age assessment of unaccompanied minors. Italy is a magnet for immigration from other countries bordering the Mediterranean Sea because the Italian coasts are within easy reach. In Italy, as in other western countries, unaccompanied asylum seekers deemed to be younger than 18 years face a very different path through the immigration system from that experienced by adults. Generally, adults are subject to immediate deportation or detention in jail. Minors are processed through the juvenile system, where detection is not mandatory; they will often have access to educational programs and may be granted a residency permit. The Section of Legal Medicine of the University of Bari was approached by immigration police authorities and judges to explore the possibility of examining unaccompanied asylum seekers, who claim do be younger than 18 years, to assess their age. A group of forensic pathologists and odontologists performed this evaluation relying on the skeletal maturation as seen on radiographs of the wrist and the pelvis for iliac crests and on an orthopantomograph, together with background information and clinical examination of each individual. Case studies are presented. This article does not attempt to give a definitive account of the different scientific methods for the assessment of age. It is important to understand some of the methods that may be used in an attempt to assess developmental maturity and from which it may be possible to "read off" an approximate chronological age.

  12. Aging on a different scale – chronological versus pathology-related aging

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    Melis, Joost P.M.; Jonker, Martijs J.; Vijg, Jan; Hoeijmakers, Jan H.J.; Breit, Timo M.; van Steeg, Harry

    2013-01-01

    In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make the necessary progression in aging research. In a recently published study we have attempted to make a step interpreting aging data on chronological as well as pathological scale. For this, we sampled five major tissues at regular time intervals during the entire C57BL/6J murine lifespan from a controlled in vivo aging study, measured the whole transcriptome and incorporated temporal as well as physical health aspects into the analyses. In total, we used 18 different age-related pathological parameters and transcriptomic profiles of liver, kidney, spleen, lung and brain and created a database that can now be used for a broad systems biology approach. In our study, we focused on the dynamics of biological processes during chronological aging and the comparison between chronological and pathology-related aging. PMID:24131799

  13. Aging on a different scale--chronological versus pathology-related aging.

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    Melis, Joost P M; Jonker, Martijs J; Vijg, Jan; Hoeijmakers, Jan H J; Breit, Timo M; van Steeg, Harry

    2013-10-01

    In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make the necessary progression in aging research. In a recently published study we have attempted to make a step interpreting aging data on chronological as well as pathological scale. For this, we sampled five major tissues at regular time intervals during the entire C57BL/6J murine lifespan from a controlled in vivo aging study, measured the whole transcriptome and incorporated temporal as well as physical health aspects into the analyses. In total, we used 18 different age-related pathological parameters and transcriptomic profiles of liver, kidney, spleen, lung and brain and created a database that can now be used for a broad systems biology approach. In our study, we focused on the dynamics of biological processes during chronological aging and the comparison between chronological and pathology-related aging.

  14. The diagnostic performance of chronologic age in the assessment of skeletal maturity.

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    Baccetti, Tiziano; Franchi, Lorenzo; De Toffol, Laura; Ghiozzi, Bruno; Cozza, Paola

    2006-01-01

    The aim of this study was to analyze the relationship between chronologic age the and individual skeletal maturity as assessed by means of the cervical vertebral maturation (CVM) method during the circumpubertal period. The evaluated sample of 600 subjects consisted of 100 subjects (50 males and 50 females) for each of 6 age groups, from 9 years through 14 years of age. Individual skeletal maturity for all subjects was determined by using the CVM method. The relationship between chronologic age and the most prevalent CVM stage at each age group was evaluated statistically by means of indicators of diagnostic test performance that specify the ability of a diagnostic test to identify a condition. The diagnostic performance of chronologic age for the detection of the onset of the adolescent peak in skeletal maturation was very low both in males and in females. In male subjects, the chronologic age of 9 years +/- 6 months presented with strong diagnostic power for the identification of a pre-pubertal stage in skeletal maturation. In female subjects, the chronologic age of 14 years +/- 6 months corresponded with a strong probability of a postpubertal stage in skeletal maturation. In males, chronologic age can identify a pre-pubertal stage of skeletal development, and in females a post-pubertal stage. In both males and females, chronologic age cannot recognize the onset of the adolescent peak in skeletal maturation.

  15. Correlation of dental age, skeletal age, and chronological age among children aged 9-14 years: A retrospective study.

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    Palanisamy, Vignesh; Rao, Arathi; Shenoy, Ramya; Baranya, Suprabha Srikrishna

    2016-01-01

    Growth can be one of the most uncertain variations, but understanding the same is very important for diagnosis and treatment planning. Skeletal age and dental age have been used to determine a child's developmental age. Several researchers have evaluated the association between dental and skeletal maturity with chronologic age on different population. The purpose of the present study was to find out whether dental age estimation can be replaced for skeletal age estimation in the Dakshina Kannada population. A total of 104 samples equally distributed among both genders in the age group of 9-14 years were selected. Skeletal age was estimated using hand-wrist radiographs and Fishman's skeletal maturation index and dental age was measured using Demirjian's method. Spearman's rank-order correlation coefficients were used to measure the association between the skeletal maturity and dental maturity. The mean ages of male and female samples were determined as 11.89 ± 1.867 years and 12.21 ± 1.473 years, respectively. Chronological age was found to be positively correlated to dental age and skeletal age and found to be statistically significant (P < 0.01). The correlation between dental age and skeletal age was also found to be statistically significant with P < 0.001 and correlation coefficient of 0.683 and 0.704 for males and females. The present study showed a strong relation between the developmental ages in mixed dentition population; hence, dental age can be considered as a replacement in the study population.

  16. Correlation of chronological, skeletal, and dental age in North Indian population

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    Madhurima Nanda

    2017-01-01

    Full Text Available Aim and Objectives: The aim of the study was to find out the correlation between chronological, dental, and skeletal age. Materials and Methods: Lateral cephalograms and orthopantomograms of 100 subjects of age ranging 9–14 years were obtained for the estimation of skeletal and dental age. Dental age was assessed using Demirjian's method; skeletal age was assessed using the new improved version of the cervical vertebral maturation method given by Baccetti, Franchi, and McNamara. Statistical analysis was carried out. Student's t-test and Spearman's coefficient correlation were used to assess the relation between chronological, skeletal, and dental age. Results: The Spearman's correlation coefficient was 0.777 (P < 0.001 between chronological and dental age, 0.516 (P < 0.001 between chronological and skeletal age, and 0.563 (P < 0.001 between dental and skeletal age. Conclusion: There is a good correlation between chronological and dental age in North Indian population which was higher for males as compared to females. A moderate correlation was found between chronological and skeletal age as well as between dental and skeletal age.

  17. [Problems associated with chronological age estimation of children exploited in child pornography production].

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    Bednarek, Jarosław

    2006-01-01

    Chronological age assessment of young persons featuring in pornographic pictures and videos is crucial to prove a violation of law. The paper discusses possibilities of and difficulties inherent in age estimation in cases of production and distribution of child pornography. The presented problems were divided into technical and individual development-associated issues. Technical difficulties included lack of a reference system for biological features reconstruction, poor quality and resolution of pictures or movies, pictures retouching and photomontage. The author stressed that biological hindrances in age assessment were the consequences of interpersonal variation of developmental patterns, namely overlapping of ranges typical for feature values at particular ages and biological variations between different human populations. The described problems can render age estimation impossible or far from precise. Developing more accurate methods of estimating age from pictures and videos requires the collaboration of specialists in the field of auxology, anthropology, pediatrics, as well as experts in photography and video techniques.

  18. Integrating chronological uncertainties for annually laminated lake sediments using layer counting, independent chronologies and Bayesian age modelling (Lake Ohau, South Island, New Zealand)

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    Vandergoes, Marcus J.; Howarth, Jamie D.; Dunbar, Gavin B.; Turnbull, Jocelyn C.; Roop, Heidi A.; Levy, Richard H.; Li, Xun; Prior, Christine; Norris, Margaret; Keller, Liz D.; Baisden, W. Troy; Ditchburn, Robert; Fitzsimons, Sean J.; Bronk Ramsey, Christopher

    2018-05-01

    Annually resolved (varved) lake sequences are important palaeoenvironmental archives as they offer a direct incremental dating technique for high-frequency reconstruction of environmental and climate change. Despite the importance of these records, establishing a robust chronology and quantifying its precision and accuracy (estimations of error) remains an essential but challenging component of their development. We outline an approach for building reliable independent chronologies, testing the accuracy of layer counts and integrating all chronological uncertainties to provide quantitative age and error estimates for varved lake sequences. The approach incorporates (1) layer counts and estimates of counting precision; (2) radiometric and biostratigrapic dating techniques to derive independent chronology; and (3) the application of Bayesian age modelling to produce an integrated age model. This approach is applied to a case study of an annually resolved sediment record from Lake Ohau, New Zealand. The most robust age model provides an average error of 72 years across the whole depth range. This represents a fractional uncertainty of ∼5%, higher than the <3% quoted for most published varve records. However, the age model and reported uncertainty represent the best fit between layer counts and independent chronology and the uncertainties account for both layer counting precision and the chronological accuracy of the layer counts. This integrated approach provides a more representative estimate of age uncertainty and therefore represents a statistically more robust chronology.

  19. Chronological age and its impact on associative learning proficiency and brain structure in middle adulthood.

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    Diwadkar, Vaibhav A; Bellani, Marcella; Ahmed, Rizwan; Dusi, Nicola; Rambaldelli, Gianluca; Perlini, Cinzia; Marinelli, Veronica; Ramaseshan, Karthik; Ruggeri, Mirella; Bambilla, Paolo

    2016-01-15

    The rate of biological change in middle-adulthood is relatively under-studied. Here, we used behavioral testing in conjunction with structural magnetic resonance imaging to examine the effects of chronological age on associative learning proficiency and on brain regions that previous functional MRI studies have closely related to the domain of associative learning. Participants (n=66) completed a previously established associative learning paradigm, and consented to be scanned using structural magnetic resonance imaging. Age-related effects were investigated both across sub-groups in the sample (younger vs. older) and across the entire sample (using regression approaches). Chronological age had substantial effects on learning proficiency (independent of IQ and Education Level), with older adults showing a decrement compared to younger adults. In addition, decreases in estimated gray matter volume were observed in multiple brain regions including the hippocampus and the dorsal prefrontal cortex, both of which are strongly implicated in associative learning. The results suggest that middle adulthood may be a more dynamic period of life-span change than previously believed. The conjunctive application of narrowly focused tasks, with conjointly acquired structural MRI data may allow us to enrich the search for, and the interpretation of, age-related changes in cross-sectional samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Correlation of dental age, skeletal age, and chronological age among children aged 9-14 years: A retrospective study

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    Vignesh Palanisamy

    2016-01-01

    Full Text Available Background: Growth can be one of the most uncertain variations, but understanding the same is very important for diagnosis and treatment planning. Skeletal age and dental age have been used to determine a child′s developmental age. Several researchers have evaluated the association between dental and skeletal maturity with chronologic age on different population. The purpose of the present study was to find out whether dental age estimation can be replaced for skeletal age estimation in the Dakshina Kannada population. Methods: A total of 104 samples equally distributed among both genders in the age group of 9-14 years were selected. Skeletal age was estimated using hand-wrist radiographs and Fishman′s skeletal maturation index and dental age was measured using Demirjian′s method. Results: Spearman′s rank-order correlation coefficients were used to measure the association between the skeletal maturity and dental maturity. The mean ages of male and female samples were determined as 11.89 ± 1.867 years and 12.21 ± 1.473 years, respectively. Chronological age was found to be positively correlated to dental age and skeletal age and found to be statistically significant (P < 0.01. The correlation between dental age and skeletal age was also found to be statistically significant with P < 0.001 and correlation coefficient of 0.683 and 0.704 for males and females. Conclusion: The present study showed a strong relation between the developmental ages in mixed dentition population; hence, dental age can be considered as a replacement in the study population.

  1. What about time? Examining chronological and subjective age and their relation to work motivation

    NARCIS (Netherlands)

    Akkermans, J.; Lange, A.H. de; Heijden, B.I.J.M. van der; Kooij, D.T.A.M.; Jansen, P.G.W.; Dikkers, J.S.E.

    2016-01-01

    PURPOSE - The aging workforce is becoming an increasingly important topic in today’s labor market. However, most scientific research and organizational policies focus on chronological age as the main determinant of successful aging. Based on life span developmental theories – primarily

  2. What about time? : Examining chronological and subjective age and their relation to work motivation.

    NARCIS (Netherlands)

    Akkermans,; De Lange,; Van der Heijden,; Kooij, T.A.M.; Jansen,; Dikkers,

    2016-01-01

    Purpose The aging workforce is becoming an increasingly important topic in today’s labor market. However, most scientific research and organizational policies focus on chronological age as the main determinant of successful aging. Based on life span developmental theories – primarily socioemotional

  3. Correlation between chronological age, cervical vertebral maturation and Fishman's skeletal maturity indicators in southern Chinese.

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    Alkhal, Hessa Abdulla; Wong, Ricky W K; Rabie, A Bakr M

    2008-07-01

    To investigate the correlation between chronological age, cervical vertebral maturation (CVM), and Fishman's hand-wrist skeletal maturity indicators in southern Chinese. Four hundred contemporary hand-wrist and lateral cephalometric radiographs of southern Chinese subjects were randomly selected and analyzed. The female subjects were between 10 and 15 years of age, and the male subjects were between 12 and 17 years of age; all subjects were within the circumpubertal period. The CVM was assessed using the method developed by Baccetti and coworkers, but the hand-wrist maturation was assessed using the method developed by Fishman. These two methods and the chronological age were correlated using the Spearman rank correlation analysis. The CVM was significantly correlated with the hand-wrist skeletal age (Spearman r male = 0.9206, female = 0.9363). All patients in the cervical maturation stage (CS3) of CVM were discovered to be in the skeletal maturational indicator (SMI2 or SMI3) stages of hand-wrist maturation (HWM), which was around the peak of the growth spurt. Low correlations were found between the CVM and chronological age (male r = 0.7577; female r = 0.7877) and between the HWM and chronological age (male r = 0.7492; female r = 0.7758). CVM is a valid indicator of skeletal growth during the circumpubertal and has a high correlation with the HWM for the southern Chinese population. However, the low correlations found between the chronological age and both CVM and HWM showed that the chronological age was not suitable to measure skeletal maturity.

  4. Ethanol and Acetate Acting as Carbon/Energy Sources Negatively Affect Yeast Chronological Aging

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    Ivan Orlandi

    2013-01-01

    Full Text Available In Saccharomyces cerevisiae, the chronological lifespan (CLS is defined as the length of time that a population of nondividing cells can survive in stationary phase. In this phase, cells remain metabolically active, albeit at reduced levels, and responsive to environmental signals, thus simulating the postmitotic quiescent state of mammalian cells. Many studies on the main nutrient signaling pathways have uncovered the strong influence of growth conditions, including the composition of culture media, on CLS. In this context, two byproducts of yeast glucose fermentation, ethanol and acetic acid, have been proposed as extrinsic proaging factors. Here, we report that ethanol and acetic acid, at physiological levels released in the exhausted medium, both contribute to chronological aging. Moreover, this combined proaging effect is not due to a toxic environment created by their presence but is mainly mediated by the metabolic pathways required for their utilization as carbon/energy sources. In addition, measurements of key enzymatic activities of the glyoxylate cycle and gluconeogenesis, together with respiration assays performed in extreme calorie restriction, point to a long-term quiescent program favoured by glyoxylate/gluconeogenesis flux contrary to a proaging one based on the oxidative metabolism of ethanol/acetate via TCA and mitochondrial respiration.

  5. Age determination of marine sediments in the western North Pacific by aspartic acid chronology

    International Nuclear Information System (INIS)

    Harada, Naomi; Kusakabe, Masashi; Handa, Nobuhiko; Oba, Tadamichi; Matsuoka, Hiromi; Kimoto, Katsunori.

    1997-01-01

    The ages of fossil planktonic foraminifera, Pulleniatina obliquiloculata, in sediments (core 3bPC) from the western North Pacific were determined by aspartic acid chronology, which uses the racemization reaction rate constant of aspartic acid (k Asp ). Aspartic acid racemization-based ages (Asp ages) ranged from 7,600 yrBP at the surface, to 307,000 yrBP at a depth of 352.9 cm in the sediments. This sediment core was also dated by the glacial-interglacial fluctuation of σ 18 O chronology, and the ages determined by both chronologies were compared. The ages derived from aspartic acid chronology and σ 18 O stratigraphy were more or less consistent, but there appeared to be some differences in age estimates between these two dating methods at some depths within the core. In the core top sediments, the likely cause for the age discrepancy could be the loss of the surface sediment during sampling of the core. At depths of 66.3 and 139 cm within the core, Asp ages indicated reduced sedimentation rates during ca. 60,000-80,000 yrBP and ca. 140,000-190,000 yrBP. The maximum age differences in both chronologies are 33,000 yr and 46,600 yr during each of these periods. These anomalous reductions in sedimentation rates occurring during these periods could possibly be related to some geological events, such as an increased dissolution effect of the calcium carbonate in the western North Pacific. Another possible reason for these age differences could be the unreliability in σ 18 O ages of core 3bPC as they were estimated by σ 18 O ages of another core, 3aPC. (author)

  6. Older patients’ recall of online cancer information: Do ability and motivation matter more than chronological age?

    NARCIS (Netherlands)

    Bol, N.; Smets, E.M.A.; Burgers, J.A.; Samii, S.M.; de Haes, H.C.J.M.; van Weert, J.C.M.

    2018-01-01

    This study proposes and tests a model to provide a more comprehensive understanding of the contribution of chronological age versus age-related ability and motivation factors in explaining recall of online cancer information among older patients (n = 197). Results revealed that recall is not a

  7. Northern Chinese dental ages estimated from southern Chinese reference datasets closely correlate with chronological age

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    Hai Ming Wong

    2016-12-01

    Full Text Available While northern and southern Chinese are genetically correlated, there exists notable environmental differences in their living conditions. This study aimed to evaluate validity of the southern Chinese reference dataset for dental age estimation applied to northern Chinese. Dental panoramic tomographs of 437 northern Chinese aged 3 to 21 years were analysed. All the left maxillary and mandibular permanent teeth plus the 2 third molars on the right side were scored based on Demirjian’s classification of tooth development stages. Mean and standard error of dental age were obtained for each tooth development stage, followed by random effect meta-analysis for mean dental age estimation. Validity of the method was examined through measures of agreement (95% limits of agreement, standard error of measurement, and Lin’s concordance correlation coefficient and measure of reliability (Intraclass correlation coefficient. On average, the estimated dental age overestimated chronological age by only around 1 month in both females and males. The Intraclass correlation coefficient values were 0.99 for both sexes, suggesting excellent reliability of the method. Reference dataset for dental age estimation developed on the basis of southern Chinese was applicable for use among the northern Chinese.

  8. Correlation between cervical vertebral maturation and chronological age in a group of Iranian females.

    Science.gov (United States)

    Safavi, Seyed Mohammadreza; Beikaii, Hanie; Hassanizadeh, Raheleh; Younessian, Farnaz; Baghban, Alireza Akbarzadeh

    2015-01-01

    Correlation between chronological age at different stages of cervical vertebral maturation (CVM) is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients. This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant. The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62). The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra. Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients.

  9. Correlation between cervical vertebral maturation and chronological age in a group of Iranian females

    Directory of Open Access Journals (Sweden)

    Seyed Mohammadreza Safavi

    2015-01-01

    Full Text Available Background: Correlation between chronological age at different stages of cervical vertebral maturation (CVM is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients. Materials and Methods: This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant. Results: The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62. The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra. Conclusion: Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients.

  10. Correlation between cervical vertebral maturation and chronological age in a group of Iranian females

    Science.gov (United States)

    Safavi, Seyed Mohammadreza; Beikaii, Hanie; Hassanizadeh, Raheleh; Younessian, Farnaz; Baghban, Alireza Akbarzadeh

    2015-01-01

    Background: Correlation between chronological age at different stages of cervical vertebral maturation (CVM) is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients. Materials and Methods: This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant. Results: The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62). The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra. Conclusion: Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients. PMID:26604958

  11. A matter of months: High precision migration chronology of a Bronze Age female

    Science.gov (United States)

    Villa, Chiara; Jørkov, Marie Louise; Allentoft, Morten E.; Kaul, Flemming; Ethelberg, Per; Reiter, Samantha S.; Wilson, Andrew S.; Taube, Michelle; Olsen, Jesper; Lynnerup, Niels; Willerslev, Eske; Kristiansen, Kristian; Frei, Robert

    2017-01-01

    Establishing the age at which prehistoric individuals move away from their childhood residential location holds crucial information about the socio dynamics and mobility patterns in ancient societies. We present a novel combination of strontium isotope analyses performed on the over 3000 year old “Skrydstrup Woman” from Denmark, for whom we compiled a highly detailed month-scale model of her migration timeline. When combined with physical anthropological analyses this timeline can be related to the chronological age at which the residential location changed. We conducted a series of high-resolution strontium isotope analyses of hard and soft human tissues and combined these with anthropological investigations including CT-scanning and 3D visualizations. The Skrydstrup Woman lived during a pan-European period characterized by technical innovation and great social transformations stimulated by long-distance connections; consequently she represents an important part of both Danish and European prehistory. Our multidisciplinary study involves complementary biochemical, biomolecular and microscopy analyses of her scalp hair. Our results reveal that the Skrydstrup Woman was between 17–18 years old when she died, and that she moved from her place of origin -outside present day Denmark- to the Skrydstrup area in Denmark 47 to 42 months before she died. Hence, she was between 13 to 14 years old when she migrated to and resided in the area around Skrydstrup for the rest of her life. From an archaeological standpoint, this one-time and one-way movement of an elite female during the possible “age of marriageability” might suggest that she migrated with the aim of establishing an alliance between chiefdoms. Consequently, this detailed multidisciplinary investigation provides a novel tool to reconstruct high resolution chronology of individual mobility with the perspective of studying complex patterns of social and economic interaction in prehistory. PMID:28582402

  12. Nicotinamide supplementation phenocopies SIR2 inactivation by modulating carbon metabolism and respiration during yeast chronological aging.

    Science.gov (United States)

    Orlandi, Ivan; Pellegrino Coppola, Damiano; Strippoli, Maurizio; Ronzulli, Rossella; Vai, Marina

    2017-01-01

    Nicotinamide (NAM), a form of vitamin B 3 , is a byproduct and noncompetitive inhibitor of the deacetylation reaction catalyzed by Sirtuins. These represent a family of evolutionarily conserved NAD + -dependent deacetylases that are well-known critical regulators of metabolism and aging and whose founding member is Sir2 of Saccharomyces cerevisiae. Here, we investigated the effects of NAM supplementation in the context of yeast chronological aging, the established model for studying aging of postmitotic quiescent mammalian cells. Our data show that NAM supplementation at the diauxic shift results in a phenocopy of chronologically aging sir2Δ cells. In fact, NAM-supplemented cells display the same chronological lifespan extension both in expired medium and extreme Calorie Restriction. Furthermore, NAM allows the cells to push their metabolism toward the same outcomes of sir2Δ cells by elevating the level of the acetylated Pck1. Both these cells have the same metabolic changes that concern not only anabolic pathways such as an increased gluconeogenesis but also respiratory activity in terms both of respiratory rate and state of respiration. In particular, they have a higher respiratory reserve capacity and a lower non-phosphorylating respiration that in concert with a low burden of superoxide anions can affect positively chronological aging. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method).

    Science.gov (United States)

    Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

    2017-01-01

    Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant ( P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old ( P stages were below 18 years old ( P stages and age were above 90% (all P age ( P = 0.000) and being maxillary ( P = 0.000) but not sex ( P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations.

  14. Proteomics of muscle chronological ageing in post-menopausal women

    NARCIS (Netherlands)

    Gueugneau, M.; Coudy, C.; Gourbeyre, O.; Chambon, C.; Combaret, L.; Polge, C.; Tailandier, D.; Attaix, D.; Friguet, B.; Maier, A.B.; Butler-Browne, G.; Bechet, D.

    2014-01-01

    Background: Muscle ageing contributes to both loss of functional autonomy and increased morbidity. Muscle atrophy accelerates after 50 years of age, but the mechanisms involved are complex and likely result from the alteration of a variety of interrelated functions. In order to better understand the

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

    NARCIS (Netherlands)

    Keyes, C.L.M.; Westerhof, Gerben Johan

    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

  16. Chronology of age-related disease definitions : Osteoporosis and sarcopenia

    NARCIS (Netherlands)

    Bijlsma, A. Y.; Meskers, C. G.M.; Westendorp, R. G.J.; Maier, A. B.

    Low muscle mass at older age has been associated with functional impairments, cognitive decline and mortality. The term sarcopenia, coined in 1988, has been used interchangeably to describe low muscle mass, strength, and function. Without a well defined definition, results of studies using the term

  17. MRI to determine the chronological age of Ghanaian footballers ...

    African Journals Online (AJOL)

    To evaluate the age of Ghanaian soccer players who are aspiring to play for the national under-17 (U17) team, using the degree of fusion of the distal radius on magentic resonance imaging (MRI) and comparing it with the Fédération Internationale de Football Association (FIFA) MRI grading. Methods. MRI scans of the left ...

  18. Implications of new age of Mallapur Intrusives on the chronology ...

    Indian Academy of Sciences (India)

    Shilpa Patil Pillai

    2018-03-27

    Mar 27, 2018 ... the Badami Group was deposited around 1700 Ma; an interpretation based on equivalences with the. Papaghni and Chitravati Groups from the Cud- dapah basin. Kale (2015) argued in favor of a much younger age of the Kaladgi Supergroup and pointed out lacunae in the assumptions supporting the older ...

  19. Acceleration of cardiovascular-biological age by amphetamine exposure is a power function of chronological age.

    Science.gov (United States)

    Reece, Albert Stuart; Norman, Amanda; Hulse, Gary Kenneth

    2017-01-01

    Amphetamine abuse is becoming more widespread internationally. The possibility that its many cardiovascular complications are associated with a prematurely aged cardiovascular system, and indeed biological organism systemically, has not been addressed. Radial arterial pulse tonometry was performed using the SphygmoCor system (Sydney). 55 amphetamine exposed patients were compared with 107 tobacco smokers, 483 non-smokers and 68 methadone patients (total=713 patients) from 2006 to 2011. A cardiovascular-biological age (VA) was determined. The age of the patient groups was 30.03±0.51-40.45±1.15 years. This was controlled for with linear regression. The sex ratio was the same in all groups. 94% of amphetamine exposed patients had used amphetamine in the previous week. When the (log) VA was regressed against the chronological age (CA) and a substance-type group in both cross-sectional and longitudinal models, models quadratic in CA were superior to linear models (both p<0.02). When log VA/CA was regressed in a mixed effects model against time, body mass index, CA and drug type, the cubic model was superior to the linear model (p=0.001). Interactions between CA, (CA) 2 and (CA) 3 on the one hand and exposure type were significant from p=0.0120. The effects of amphetamine exposure persisted after adjustment for all known cardiovascular risk factors (p<0.0001). These results show that subacute exposure to amphetamines is associated with an advancement of cardiovascular-organismal age both over age and over time, and is robust to adjustment. That this is associated with power functions of age implies a feed-forward positively reinforcing exacerbation of the underlying ageing process.

  20. 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…

  1. Nutritional Control of Chronological Aging and Heterochromatin inSaccharomyces cerevisiae.

    Science.gov (United States)

    McCleary, David F; Rine, Jasper

    2017-03-01

    Calorie restriction extends life span in organisms as diverse as yeast and mammals through incompletely understood mechanisms.The role of NAD + -dependent deacetylases known as Sirtuins in this process, particularly in the yeast Saccharomyces cerevisiae , is controversial. We measured chronological life span of wild-type and sir2 Δ strains over a higher glucose range than typically used for studying yeast calorie restriction. sir2 Δ extended life span in high glucose complete minimal medium and had little effect in low glucose medium, revealing a partial role for Sir2 in the calorie-restriction response under these conditions. Experiments performed on cells grown in rich medium with a newly developed genetic strategy revealed that sir2 Δ shortened life span in low glucose while having little effect in high glucose, again revealing a partial role for Sir2 In complete minimal media, Sir2 shortened life span as glucose levels increased; whereas in rich media, Sir2 extended life span as glucose levels decreased. Using a genetic strategy to measure the strength of gene silencing at HML , we determined increasing glucose stabilized Sir2-based silencing during growth on complete minimal media. Conversely, increasing glucose destabilized Sir-based silencing during growth on rich media, specifically during late cell divisions. In rich medium, silencing was far less stable in high glucose than in low glucose during stationary phase. Therefore, Sir2 was involved in a response to nutrient cues including glucose that regulates chronological aging, possibly through Sir2-dependent modification of chromatin or deacetylation of a nonhistone protein. Copyright © 2017 by the Genetics Society of America.

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

    Science.gov (United States)

    Hubley, Anita M.; Arim, Rubab G.

    2012-01-01

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

  3. Evaluation of third molar development in the estimation of chronological age.

    Science.gov (United States)

    Soares, Caio Belém Rodrigues Barros; Figueiroa, José Natal; Dantas, Renata Moura Xavier; Kurita, Lúcio Mitsuo; Pontual, Andréa dos Anjos; Ramos-Perez, Flávia Maria de Moraes; Perez, Danyel Elias da Cruz; Pontual, Maria Luiza dos Anjos

    2015-09-01

    The purpose of this study was to evaluate the correlation between chronological age and the degree of third molar mineralization by Demirjian's developmental stages (Demirjian et al., 1973) using panoramic radiography. From a total of 11.396 digital panoramic radiographs of patients from three oral radiology private clinics from the northeast region of Brazil, obtained from January to June 2009, 2097 radiographic images from patients aged between 6 and 22 years were selected. The images were analyzed individually by two obsevers using a 21-inch computer screen and Windows Picture and Fax Viewer. Reliability was achieved by intra- and interobserver evaluation, using the Kappa test. Chronological age, calcification stage, gender and third molar were interrelated using a multiple linear regression model, considering age as a response variable. There was reliability with Demirjian et al.'s developmental stage assesment, displaying a significant relationship between mineralization stages and patients' age (Page and the calcification stage taking gender and localization of the third molar into consideration. It is possible to estimate chronological age based on Demirjian's stage of a third molar, regardless of gender and location. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. 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

  5. A microarray-based genetic screen for yeast chronological aging factors.

    Directory of Open Access Journals (Sweden)

    Mirela Matecic

    2010-04-01

    Full Text Available Model organisms have played an important role in the elucidation of multiple genes and cellular processes that regulate aging. In this study we utilized the budding yeast, Saccharomyces cerevisiae, in a large-scale screen for genes that function in the regulation of chronological lifespan, which is defined by the number of days that non-dividing cells remain viable. A pooled collection of viable haploid gene deletion mutants, each tagged with unique identifying DNA "bar-code" sequences was chronologically aged in liquid culture. Viable mutants in the aging population were selected at several time points and then detected using a microarray DNA hybridization technique that quantifies abundance of the barcode tags. Multiple short- and long-lived mutants were identified using this approach. Among the confirmed short-lived mutants were those defective for autophagy, indicating a key requirement for the recycling of cellular organelles in longevity. Defects in autophagy also prevented lifespan extension induced by limitation of amino acids in the growth media. Among the confirmed long-lived mutants were those defective in the highly conserved de novo purine biosynthesis pathway (the ADE genes, which ultimately produces IMP and AMP. Blocking this pathway extended lifespan to the same degree as calorie (glucose restriction. A recently discovered cell-extrinsic mechanism of chronological aging involving acetic acid secretion and toxicity was suppressed in a long-lived ade4Delta mutant and exacerbated by a short-lived atg16Delta autophagy mutant. The identification of multiple novel effectors of yeast chronological lifespan will greatly aid in the elucidation of mechanisms that cells and organisms utilize in slowing down the aging process.

  6. DNA damage markers in dermal fibroblasts in vitro reflect chronological donor age

    DEFF Research Database (Denmark)

    Waaijer, Mariëtte E C; Croco, Eleonora; Westendorp, Rudi G J

    2016-01-01

    and presence of cardiovascular diseases. Therefore, numbers of 53BP1 foci, telomere-associated foci (TAF) and micronuclei were measured in cultured dermal fibroblasts obtained from three age groups of donors (mean age 22, 63 and 90 years). Fibroblasts were cultured without a stressor and with 0.6 μM rotenone...... markers and long-lived family membership or cardiovascular disease. Results were comparable when fibroblasts were stressed in vitro with rotenone. In conclusion, we found that DNA damage foci of cultured fibroblasts are significantly associated with the chronological age, but not biological age...

  7. Dental maturity as an indicator of chronological age: radiographic assessment of dental age in a brazilian population

    Directory of Open Access Journals (Sweden)

    Lucio Mitsuo Kurita

    2007-04-01

    Full Text Available OBJECTIVE: The purpose of this investigation was to evaluate the applicability of the methods proposed by Nolla and by Nicodemo and colleagues for assessing dental age and its correlation to chronological age. METHODS: Panoramic radiographs of 360 patients from the city of Fortaleza (CE, Brazil aged 7-15 years were used to assess the associations between dental and chronological age. Data were submitted to statistical analysis using the BioEstat 2.0 (2000 software. Student-Neuman-Keuls test was performed and Pearson's correlation coefficients were calculated at 5% significance level. RESULTS: When the Nolla method was applied, the mean difference between true and estimated age for males and females was underestimated. The use of the method proposed by Nicodemo and colleagues also resulted in underestimation, although it was more evident in male subjects. The correlation coefficients between chronological age and estimated dental age were high, with mean values ranging between 0.87 and 0.91 for males and between 0.84 and 0.93 for females. CONCLUSION: Although both methods proved to be reliable in estimating age, the use of correction factors is recommended.

  8. Relationship between pulp-tooth volume ratios and chronological age in different anterior teeth on CBCT

    OpenAIRE

    Biuki, Nima; Razi, Tahmineh; Faramarzi, Masoumeh

    2017-01-01

    Background The CBCT imaging technique exhibits proper accuracy to determine the internal anatomy of teeth. Therefore, this technique can use to estimate age by measuring the amount of decrease in the volume of the pulpal cavity of teeth. The aim of the present study was to evaluate the correlation between chronological age and pulp-to-tooth volume ratios in anterior teeth with the use of the CBCT technique and to determine a regression model to estimate human age. Material and Methods In this...

  9. Relation between body weight, growth rate, chronological age and puberty in male and female rats.

    Science.gov (United States)

    Aguilar, E; Pinilla, L; Guisado, R; González, D; López, F

    1984-03-01

    Body weight, growth rate, chronological age and puberty in female and male rats from litters of 8 and 12 offsprings/mother have been studied. Age and body weight at the moment of vaginal opening (VO) and balanopreputial separation (BPS) were analyzed. Results show that animals reared in smaller groups grew faster than others. After weaning there was an increase in growth rate. VO and BPS occurred at the same age in groups with different growth rates and different body weights. In conclusion this work evidences that external signs of sexual maturation are not linked to a "critical weight" or to a "growth rate".

  10. Assessment of skeletal age using MP 3 and hand-wrist radiographs and its correlation with dental and chronological ages in children

    Directory of Open Access Journals (Sweden)

    Bala M

    2010-06-01

    Full Text Available The purpose of the study was to assess skeletal age using MP 3 and hand-wrist radiographs and to find the correlation amongst the skeletal, dental and chronological ages. One hundred and sixty North-Indian healthy children in the age group 8-14 years, comprising equal number of males and females were included in the study. The children were radiographed for middle phalanx of third finger (MP 3 and hand-wrist of the right hand and intra oral periapical X-ray for right permanent maxillary canine. Skeletal age was assessed from MP 3 and hand-wrist radiographs according to the standards of Greulich and Pyle. The dental age was assessed from IOPA radiographs of right permanent maxillary canine based on Nolla′s calcification stages. Skeletal age from MP 3 and hand-wrist radiographs shows high correlation in all the age groups for both sexes. Females were advanced in skeletal maturation than males. Skeletal age showed high correlation with dental age in 12-14 years age group. Chronological age showed inconsistent correlation with dental and skeletal ages.

  11. The chronology of second molar development in Brazilians and its application to forensic age estimation

    International Nuclear Information System (INIS)

    Almeida, Manuella; Santos Carneiro; Beltraeo, Rejane Targino; Beltraeo, Ricardo Villar; Pontual, Andrea dos Anjos; Pontual, Maria Luiza dos Anjos

    2013-01-01

    This study investigated the possible correlation between the mineralization of the second molars and the chronological age of a sample population of the state of Paraiba, Brazil. One thousand eight hundred fifty-four digitized panoramic images using a scanner of a private dental radiology service were obtained in six months. Of these, 457 were selected from patients aged 4.6 to 16 years who met certain criteria. The images were assessed twice by a radiologist with 5 years experience. A minimum interval of 30 days between the evaluations of the same patient was established. To analyze the relationship between chronological age, calcification level proposed by Demirjian et al in 1973, gender, and tooth, a multiple linear regression model was adjusted, taking age as the response variable (p<0.05). The gender and calcification level were significantly correlated with the age of the patients (p<0.05). There was a significant difference between the average age of the patients' upper teeth compared to the lower ones in both genders (p<0.05). The dental development occurred earlier in female individuals than in male ones, and there was no significant difference between the right and left second permanent molars. It was observed that ethnic variables are related to certain parameters of age and sex identification in the Brazilian population, providing important information for forensic evaluations.

  12. Evaluation of third molar development and its relation to chronological age: a panoramic radiographic study.

    Science.gov (United States)

    Zandi, Mohammad; Shokri, Abbas; Malekzadeh, Hamid; Amini, Payam; Shafiey, Parastu

    2015-06-01

    Third molar development, in comparison to other teeth in the dentition, has the greatest variation in morphology, anatomical position, and time of development and eruption, and its reliability for chronological age estimation is controversial. The aim of the present study was to evaluate third molar development and its relation to chronological age using panoramic radiography. A total of 2536 digital panoramic radiographs of individuals aged between 5 and 26 years were selected. The developmental status of the third molars was assessed using eight-stage developmental scoring proposed by Demirjian et al., with one modification: a stage 0 was added. The collected data were entered into a checklist and subjected to statistical analyses. The mean ages of the first appearance of third molar bud, complete crown formation, and root apex closure were around 9, 14, and 22 years, respectively. In both jaws, third molar development occurred symmetrically, and sexual dimorphism was observed at some developmental stages. Finally, two formulas were presented to estimate age of the juveniles and adolescents based on their gender and developmental stages of the third molars, and validated on a second sample consisting of 523 individuals aged between 8 and 22. Assessment of third molar development was found to be a reliable method for age estimation of individuals between 11 and 22 years. Because of possible ethnic and geographic differences in third molar development, population specific researches were recommended.

  13. Dental and Chronological Ages as Determinants of Peak Growth Period and Its Relationship with Dental Calcification Stages.

    Science.gov (United States)

    Litsas, George; Lucchese, Alessandra

    2016-01-01

    To investigate the relationship between dental, chronological, and cervical vertebral maturation growth in the peak growth period, as well as to study the association between the dental calcification phases and the skeletal maturity stages during the same growth period. Subjects were selected from orthodontic pre-treatment cohorts consisting of 420 subjects where 255 were identified and enrolled into the study, comprising 145 girls and 110 boys. The lateral cephalometric and panoramic radiographs were examined from the archives of the Department of Orthodontics, Aristotle University of Thessaloniki, Greece. Dental age was assessed according to the method of Demirjian, and skeletal maturation according to the Cervical Vertebral Maturation Method. Statistical elaboration included Spearman Brown formula, descriptive statistics, Pearson's correlation coefficient and regression analysis, paired samples t-test, and Spearman's rho correlation coefficient. Chronological and dental age showed a high correlation for both gender(r =0.741 for boys, r = 0.770 for girls, pStage IV for both males (r=0.554) and females (r=0.68). The lowest correlation was for the CVM Stage III in males (r=0.433, pStage II in females (r=0.393, p>0.001). The t-test revealed statistically significant differences between these variables (pstages was determined. The second molars showed the highest correlation with CVM stages (CVMS) (r= 0.65 for boys, r = 0.72 for girls). Dental age was more advanced than chronological for both boys and girls for all CVMS. During the peak period these differences were more pronounced. Moreover, all correlations between skeletal and dental stages were statistically significant. The second molars showed the highest correlation whereas the canines showed the lowest correlation for both gender.

  14. An evaluation of third molar eruption for assessment of chronologic age: A panoramic study.

    Science.gov (United States)

    Tuteja, Monica; Bahirwani, Shraddha; Balaji, P

    2012-01-01

    The identity of a person can be established by assessing one's age, and in order to be entitled to civil rights and social benefits, verification of the chronological age is required and thereby age estimation has gained an increasing significance in recent years. Tooth eruption is one of the criteria of developmental morphology that can be evaluated by either clinical examination or by evaluation of dental radiographs to determine the dental age. The present study was aimed to evaluate the reliability of the third molar eruption stage as a parameter for forensic age estimation in living subjects. The stage of wisdom tooth eruption in 77 male and 73 female Indian subjects aged between 12-26 years was determined by subjecting them to conventional orthopantomograms and was interpreted to assess the third molar eruption stages to evaluate the dental age. Predicted minimum age and mean age of the study sample were found to be significant predictors (Page. Minimum age was able to explain 58.3% of the variation in actual age and the mean age was able to explain 60.3% of variation in actual age. Third molar is fairly a reliable indicator to determine the age of alveolar, gingival, and complete emergence of third molar in the occlusal plane in adolescents and young adults. Minimum and most probable ages of examined subjects can also be evaluated using third molar eruption stage.

  15. Mineralization of mandibular third molars can estimate chronological age--Brazilian indices.

    Science.gov (United States)

    de Oliveira, Fernando Toledo; Capelozza, Ana Lúcia Álvares; Lauris, José Roberto Pereira; de Bullen, Izabel Regina Fischer Rubira

    2012-06-10

    Forensic age estimation is an important element of anthropological research, as it produces one of the primary sources of data that researchers use to establish the identity of a person living or the identity of unknown bodily remains. The aim of this study was to determine if the chronology of third molar mineralization could be an accurate indicator of estimated age in a sample Brazilian population. If so, mineralization could determine the probability of an individual being 18 years or older. The study evaluated 407 panoramic radiographs of males and females from the past 5 years in order to assess the mineralization status of the mandibular third molars. The evaluation was carried out using an adaptation of Demirjian's system. The results indicated a strong correlation between chronological age and the mineralization of the mandibular third molars. The results indicated that modern Brazilian generation tends to demonstrate an earlier mandibular third molar mineralization than older Brazilian generation and people of other nationalities. Males reached developmental stages slightly earlier than females, but statistically significant differences between the sex were not found. The probability that an individual with third molar mineralization stage H had reached an age of 18 years or older was 96.8-98.6% for males and females, respectively. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Chronological age affects the permeation of fentanyl through human skin in vitro

    DEFF Research Database (Denmark)

    Holmgaard, R; Benfeldt, E; Sorensen, J A

    2013-01-01

    AIM: To study the influence of chronological age on fentanyl permeation through human skin in vitro using static diffusion cells. Elderly individuals are known to be more sensitive to opioids and obtain higher plasma concentrations following dermal application of fentanyl compared to younger...... individuals. The influence of age - as an isolated pharmacokinetic term - on the absorption of fentanyl has not been previously studied. METHOD: Human skin from 30 female donors was mounted in static diffusion cells, and samples were collected during 48 h. Donors were divided into three age groups: ... and old age groups: 5,922 and 4,050 ng, respectively). Furthermore, the lag time and absorption rate were different between the three groups, with a significantly higher rate in the young participants versus the oldest participants. CONCLUSION: We demonstrate that fentanyl permeates the skin of young...

  17. Chronological Age as Factor Influencing the Dental Implant Osseointegration in the Jaw Bone

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    Jan Papež

    2018-04-01

    Full Text Available The objectives of this study were to evaluate osseointegration of dental implant in the jaw bone in the young and elderly population and comparing the results to assess indicators and risk factors as age for the success or failure of dental implants. A retrospective study of 107 implants (Impladent, LASAK, Czech Republic was prepared. The patients at implants surgery were divided in three groups. The patients were followed-up for a 7-year period. We evaluated osseointegration from long term point of view as a change of marginal bone levels close to dental implant. Marginal bone levels were recorded and analysed with regard to different patient- and implant-related factors. An influence of chronological age on change of marginal bone levels during 6-year retrospective study vas evaluated. The study examined 47 patient charts and 107 implants from the Second Faculty of Medicine, Charles University and University Hospital Motol. We proved that young healthy patients with long bridges or Branemarks have the same progression of marginal bone levels changes. The chronological age hasn’t therefore direct influence on the osseointegration from long term point of view. But we found that the length of dental suprastrucure-prosthetic construction negatively influences marginal bone changes, though these results weren’t statistically significant. More extensive dental implant suprastrucure undergoes smaller osseointegration. On the other hand the length of dental suprastrucure (prosthetic construction negatively influences dental osseointegration in both groups of patient.

  18. The chronological age estimation of third molar mineralization of Han population in southwestern China.

    Science.gov (United States)

    Qing, Maofeng; Qiu, Lihua; Gao, Zhi; Bhandari, Kishor

    2014-05-01

    The purpose of the study was to estimate the chronology of third molar mineralization in Han population of southwestern China and find its unique characteristics so that it would provide a reference in several legal cases like forensic age estimation. The study used Demirjian's staging method to study 2192 orthopantomograms of 984 male and 1208 female subjects aged between 8 and 25 years. The statistical data was analyzed by Student's t test and ANOVA. The conclusions of the study are: (1) The chronological mineralization age of third molars of Han population in Southwestern China is similar to the Turkish and the Japanese, was earlier than the Austrian and Han of South China, but later than the Spanish. (2) The mineralization timing of the third molars between two sides in maxilla or mandible has no significant differences in the same gender group. (3) There is no significant difference in mineralization of third molars between male and female, except for tooth 48 in Demirjian's stage E. (4) The mineralization of third molar in maxilla is earlier than mandible. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  19. 6-year changes in body composition in women at mid-life: ovarian and chronological aging

    Science.gov (United States)

    Sowers, MaryFran; Zheng, Huiyong; Tomey, Kristin; Karvonen-Gutierrez, Carrie; Jannausch, Mary; Li, Xizhao; Yosef, Matheos; Symons, James

    2009-01-01

    Context Understanding the menopause association with body weight is important because excess weight increases risk for stroke, incident cardiovascular disease, cardiovascular mortality, and all-cause mortality among the middle-aged. Objective To examine chronological age and ovarian age and consider how these could influence body size and composition in mid-life women. Design and Setting The Study of Women’s Health Across the Nation is a longitudinal, community-based study. This report uses data from the Michigan SWAN site. Participants 543 pre- or early perimenopausal African-American and Caucasian women aged 42–52 years at baseline examination. Main Outcome Measures Waist circumference, fat mass and skeletal muscle mass, from bioelectrical impedance, was assessed in 7 annual serial measures. Annual follicle-stimulating hormone (FSH) values were assayed by ELISA. The final menstrual period (FMP) was defined retrospectively following 12 months of amenorrhea. Results There was an absolute cumulative six-year increase in fat mass of 3.4 kg and a six-year decrease in skeletal muscle mass of ~0.23 kg. There was an absolute cumulative six-year increase of ~5.7 cm in waist circumference. The logFSH change was positively correlated with log(fat mass) change. Waist circumference increased over the time period, but one year following FMP, the rate of increase slowed. Fat mass continued to increase with no change in rate. Conclusions Both time (chronological aging) and ovarian aging contributed to substantial changes in body composition (fat and skeletal muscle mass) and waist circumference. These changes have important ramifications for establishing a metabolic environment that can be healthy or unhealthy. PMID:17192296

  20. Third molar mineralization in relation to chronologic age estimation of the Han in central southern China.

    Science.gov (United States)

    Liu, Ying; Geng, Kun; Chu, Yanhao; Xu, Mindi; Zha, Lagabaiyila

    2018-03-03

    The purpose of this study is to provide a forensic reference data about estimating chronologic age by evaluating the third molar mineralization of Han in central southern China. The mineralization degree of third molars was assessed by Demirjian's classification with modification for 2519 digital orthopantomograms (1190 males, 1329 females; age 8-23 years). The mean ages of the initial mineralization and the crown completion of third molars were around 9.66 and 13.88 years old in males and 9.52 and 14.09 years old in females. The minimum ages of apical closure were around 16 years in both sexes. Twenty-eight at stage C and stage G and 38 and 48 at stage F occurred earlier in males than in females. There was no significant difference between maxillary and mandibular teeth in males and females except that stage C in males. Two formulas were devised to estimate age based on mineralization stages and sexes. In Hunan Province, the person will probably be over age 14, when a third molar reaches the stage G. The results of the study could provide reference for age estimation in forensic cases and clinical dentistry.

  1. The role of forensic medicine and forensic dentistry in estimating the chronological age of living individuals in Hamburg, Germany.

    Science.gov (United States)

    Mansour, Hussam; Fuhrmann, Andreas; Paradowski, Ioana; van Well, Eilin Jopp; Püschel, Klaus

    2017-03-01

    Age estimation represents one of the primary responsibilities of forensic medicine and forensic dentistry. It is an integral procedure aiming to estimate the chronological age of an individual, whose age is either unknown or doubtful, by means of assessing the stage of dental, skeletal, and physical development. The present publication reviews the methods and procedures used in estimating the age of young living individuals as well as the experiences of the Institute of Legal Medicine in Hamburg-Eppendorf, Germany, during the last 25 years. From 1990 to 2015, 4223 age estimations were carried out in Hamburg. During this time, forensic age estimation was requested by different concerned authorities including courts, the foreigners' registration office (Zentrale Ausländerbehörde), and the state office of education and consultation (Landesbetrieb Erziehung und Beratung). In the context of judicial proceedings, orthopantomograms, as well as X-ray examinations of both the left hand and the medial clavicular epiphyses were carried out in accordance with AGFAD recommendations. For investigations not associated with judicial proceedings, orthopantomogram examinations play a key role in the process of age estimation, due to their high diagnostic value and low radiation exposure. Since 2009, mainly unaccompanied young refugees were examined for age estimation. Orthopantomograms and clinical-physical examinations have been used as essential steps in this context to determine whether an individual is 18 years or less. Additional X-ray examinations of the left hand and the medial clavicular epiphyses have been used less frequently.

  2. Modelling Developmental Changes in Repeated-Sprint Ability by Chronological and Skeletal Ages in Young Soccer Players

    NARCIS (Netherlands)

    Valente-dos-Santos, J.; Coelho-e-Silva, M. J.; Martins, R. A.; Figueiredo, A. J.; Cyrino, E. S.; Sherar, L. B.; Vaeyens, R.; Huijgen, B. C. H.; Elferink-Gemser, M. T.; Malina, R. M.

    2012-01-01

    This study investigated the influence of chronological (CA) and skeletal ages (SA), anthropometry, aerobic endurance and lower limb explosive strength on developmental changes in repeated-sprint ability (RSA) in soccer players aged 11-17 years. Participants were annually followed over 5 years,

  3. Differences chronological age and dental age using Demirjian method based upon a study radiology using radiography panoramic at the Hasanuddin University Dental Hospital

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    Barunawaty Yunus

    2016-06-01

    Full Text Available Choronological age is assessed by the date, month, and year of birth. Several researches suggested that chronological age may not be able to provide sufficient information regarding on human growth precisely. Chronological age, on the other hand, could not be used to assess  maturity development rate of a patient, so it is necessary to assess the dental age. Dental age is age assessment method by measuring human growth and development. Age estimation has important role in health field, particularly in dentistry as it will be beneficial in making appropriate diagnosis, treatment plan, and prognosis. Tooth eruption estimation according to Demirjian method conducted by assessing growth and development process of tooth using panoramic radiography. The purpose of this study is to determine the difference between chronological age and dental age using Demirjian method based on radiology analysis of panoramic radiography. This study was an observational analytic using cross-sectional study, all data are observed once at the time. In this study, the amount of sample reviewed were 30 samples, consisted of 4 – 9 years old children. Panoramic radiography were collected based on target population which fulfill sample criteria from reconciled patient of radiology department Hasanuddin University Dental Hospital. The results were obtained by estimating the score of  dental age using Demirjian method. After that, the dental age and chronological age were analayzed to obtain the mean difference. Based on wilcoxon test, mean value was obtain p:0.011 (p<0.05, this result shows that there is significant difference between chronological age and dental age. Chronological age and dental age can be assessed by reviewing the panoramic radiography using Demirjian method.

  4. Differences chronological age and dental age using Demirjian method based upon a study radiology using radiography panoramic at the Dental Hospital Hasanuddin University

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    Barunawaty Yunus

    2016-08-01

    Full Text Available Background.Choronological age is assessed by the date, month, and year of birth. Several researches suggested that Chronological age may not be able to provide sufficient information regarding on human growth precisely. Chronological age, on the other hand, could not be used to assess  Maturity development rate of a patient, so it is necessary to assess the dental age. Dental age is age assessment method  by measuring human growth and development. Age estimation has important role in health field, Particularly  in dentistry as it will be beneficial in making appropriate diagnosis, Treatment plan, and prognosis. Tooth eruption estimation according to Demirjian Method conducted by assessing growth and development process of tooth using panoramic  radiography. Purpose. Determine the difference between Chronological Age and Dental Age Using Demirjian Method Based on Radiology Analysis of Panoramic Radiography. Method. This study was an observational analytic using Cross-sectional study, all data are observed once at the time. In this study,  the amount of sample reviewed were 30 samples, consisted of 4 – 9 years old children. Panoramic radiography were collected based on target population which fulfill Sample Criteria from reconciled patient of radiology department RSGM Unhas. The results were obtained by estimating the score of  dental age using Demirjian Method. After that, the Dental age and chronological age were analayzed to obtain the mean difference. Result. Based on wilcoxon test, mean value was obtain p:0.011 (p<0.05, this result shows that there is significant difference between chronological age and dental age. Conclusion.Chronological age and dental age can be assessed by reviewing the panoramic radiography using Demirjian Method

  5. Oral histories: a simple method of assigning chronological age to isotopic values from human dentine collagen.

    Science.gov (United States)

    Beaumont, Julia; Montgomery, Janet

    2015-01-01

    Stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in bone and dentine collagen have been used for over 30 years to estimate palaeodiet, subsistence strategy, breastfeeding duration and migration within burial populations. Recent developments in dentine microsampling allow improved temporal resolution for dietary patterns. A simple method is proposed which could be applied to human teeth to estimate chronological age represented by dentine microsamples in the direction of tooth growth, allowing comparison of dietary patterns between individuals and populations. The method is tested using profiles from permanent and deciduous teeth of two individuals. Using a diagrammatic representation of dentine development by approximate age for each human tooth (based on the Queen Mary University of London Atlas), this study estimated the age represented by each dentine section. Two case studies are shown: comparison of M1 and M2 from a 19th century individual from London, England, and identification of an unknown tooth from an Iron Age female adult from Scotland. The isotopic profiles demonstrate that variations in consecutively-forming teeth can be aligned using this method to extend the dietary history of an individual or identify an unknown tooth by matching the profiles.

  6. Radiographic assessment of third molars development and it's relation to dental and chronological age in an Iranian population.

    Science.gov (United States)

    Monirifard, Mohamad; Yaraghi, Navid; Vali, Ava; Vali, Asana; Vali, Amrita

    2015-01-01

    The aim of the present study was to estimate chronological age based on third molar development and to determine the association between dental age and third molar calcification stages. In this cross-sectional study, 505 digital panoramic radiographs of 223 males (44.2%) and 282 females (55.8%) between the age of 6 and 17 were selected from patients who were treated in Departments of Pediatrics and Orthodontics of Isfahan University of Medical Sciences between the years of 2009 and 2013. Correlation between chronological age and third molar development was analyzed with SPSS 21 using Spearman's Rank correlation coefficient, Chi-square test and multiple regression statistical tests (P third molars demonstrated a highly significant correlation with dental age (P age were mandibular left third molar in males and mandibular right third molar in females (r s = 0.072). When multiple regression was used to predict dental age based on molar calcification stage, the only significant correlation was between maxillary left third molar in males (P third molars in females. Relationship between chronological age and molars development stage was significant in all age subgroups and in both gender (P third molars and dental age in males. Results showed that third molar calcification stage can be used as an age predictor and in general mandibular teeth seems to be more reliable for this purpose in both genders and in all ages.

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

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    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.

  8. An optical age chronology of late Quaternary extreme fluvial events recorded in Ugandan dambo soils

    Science.gov (United States)

    Mahan, S.A.; Brown, D.J.

    2007-01-01

    There is little geochonological data on sedimentation in dambos (seasonally saturated, channel-less valley floors) found throughout Central and Southern Africa. Radiocarbon dating is problematic for dambos due to (i) oxidation of organic materials during dry seasons; and (ii) the potential for contemporary biological contamination of near-surface sediments. However, for luminescence dating the equatorial site and semi-arid climate facilitate grain bleaching, while the gentle terrain ensures shallow water columns, low turbidity, and relatively long surface exposures for transported grains prior to deposition and burial. For this study, we focused on dating sandy strata (indicative of high-energy fluvial events) at various positions and depths within a second-order dambo in central Uganda. Blue-light quartz optically stimulated luminescences (OSL) ages were compared with infrared stimulated luminescence (IRSL) and thermoluminescence (TL) ages from finer grains in the same sample. A total of 8 samples were dated, with 6 intervals obtained at ???35, 33, 16, 10.4, 8.4, and 5.9 ka. In general, luminescence ages were stratigraphically, geomorphically and ordinally consistent and most blue-light OSL ages could be correlated with well-dated climatic events registered either in Greenland ice cores or Lake Victoria sediments. Based upon OSL age correlations, we theorize that extreme fluvial dambo events occur primarily during relatively wet periods, often preceding humid-to-arid transitions. The optical ages reported in this study provide the first detailed chronology of dambo sedimentation, and we anticipate that further dambo work could provide a wealth of information on the paleohydrology of Central and Southern Africa. ?? 2006 Elsevier Ltd. All rights reserved.

  9. Longitudinal comparison of skeletal age determined by the Greulich and Pyle method and chronologic age in normally growing children, and clinical interpretations for orthodontics.

    Science.gov (United States)

    Suri, Sunjay; Prasad, Chandrakala; Tompson, Bryan; Lou, Wendy

    2013-01-01

    Coinciding treatment with periods of accelerated skeletal growth and maturation might be advantageous in clinical practice. Better understanding of the concordance between skeletal and chronologic ages during the period that children frequently receive orthodontic treatment is needed. The literature on skeletal age determination from hand-wrist radiographs lacks reports based on longitudinal data, creating lacunae in the understanding of the magnitudes and variations of differences between skeletal and chronologic ages. The aims of this research were to comprehensively analyze the concordance between skeletal and chronologic ages determined by using the Greulich and Pyle method at different ages in the preadolescent and adolescent periods, and to determine any age- and sex-related differences in the concordance. By using the Greulich and Pyle method, skeletal age determinations were made from 572 hand-wrist radiographs of 68 white children with normal facial growth, selected from the records of the Burlington Growth Centre, spanning the growth period from 9 to 18 years. Skeletal age and chronologic age differences for each sex were analyzed by using paired t tests and Wilcoxon signed rank tests at yearly intervals. Differences over the longitudinal duration were examined by using the mixed model approach. The limits of agreement were determined by using the Bland-Altman method. In each yearly chronologic age group, differences were clinically categorized based on the proximity of the skeletal and chronologic ages. Overall, a slightly greater proportion of the total skeletal age determinations made in girls (41.9%) were within 0.5 year of their chronologic age, compared with 38% in boys. The largest proportions of subjects having skeletal age-chronologic age differences within 0.5 year were in the 10-year age group in girls (64.5%) and the 13-year age group in boys (64.7%). Mean skeletal age-chronologic age differences were significantly larger in the 13- to 16-year

  10. Aging on a different scale - chronological versus pathology-related aging.

    NARCIS (Netherlands)

    Melis, J.P.; Jonker, M.J.; Vijg, J.; Hoeijmakers, J.H.; Breit, T.M.; van Steeg, H.

    2013-01-01

    In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make

  11. Improvement of skin condition by oral administration of collagen hydrolysates in chronologically aged mice.

    Science.gov (United States)

    Wang, Zhenbin; Wang, Qing; Wang, Lin; Xu, Weidong; He, Yuanqing; Li, Yunliang; He, Song; Ma, Haile

    2017-07-01

    Collagen hydrolysates (CHs) have been demonstrated to have positive effects on skin photoaging by topical application or oral ingestion. However, there has been little research on their influence on skin chronological aging. In this study, 9-month-old female ICR mice were given normal AIN-93M diets containing CHs (2.5, 5 and 10% w/w) from Nile tilapia scale. After 6 months, the collagen content and antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities increased significantly (P skin did not change (P > 0.05). The color, luster and quantity of hair were obviously ameliorated. Moreover, the structure of epidermis and dermis, the density and distribution of collagen fibers and the ratio of type I to type III collagen were improved in a dose-dependent manner as shown by histochemical staining. Oral ingestion of CHs increased the collagen content and antioxidant enzyme activities and improved the appearance and structure of skin. These results suggest the potential of CHs as an anti-skin-aging ingredient in nutraceuticals or functional foods. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Ammonium is toxic for aging yeast cells, inducing death and shortening of the chronological lifespan.

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    Júlia Santos

    Full Text Available Here we show that in aging Saccharomyces cerevisiae (budding yeast cells, NH(4 (+ induces cell death associated with shortening of chronological life span. This effect is positively correlated with the concentration of NH(4 (+ added to the culture medium and is particularly evident when cells are starved for auxotrophy-complementing amino acids. NH(4 (+-induced cell death is accompanied by an initial small increase of apoptotic cells followed by extensive necrosis. Autophagy is inhibited by NH(4 (+, but this does not cause a decrease in cell viability. We propose that the toxic effects of NH(4 (+ are mediated by activation of PKA and TOR and inhibition of Sch9p. Our data show that NH(4 (+ induces cell death in aging cultures through the regulation of evolutionary conserved pathways. They may also provide new insights into longevity regulation in multicellular organisms and increase our understanding of human disorders such as hyperammonemia as well as effects of amino acid deprivation employed as a therapeutic strategy.

  13. Accuracy of the estimation of dental age in comparison with chronological age in a Spanish sample of 2641 living subjects using the Demirjian and Nolla methods.

    Science.gov (United States)

    Melo, María; Ata-Ali, Javier

    2017-01-01

    Age estimation is an important procedure in forensic medicine and is carried out for a number of reasons. For living persons, age estimation is performed in order to assess whether a child has attained the age of criminal responsibility, in scenarios involving rape, kidnapping or marriage, in premature births, adoption procedures, illegal immigration, pediatric endocrine diseases and orthodontic malocclusion, as well as in circumstances in which the birth certificate is not available or the records are suspect. According to data from the UNHCR (United Nations High Commissioner for Refugees), the number of people seeking refugee status continued to increase in the last years, driven by the wars in Syria and Iraq, as well as by conflict and instability in Afghanistan, Eritrea and elsewhere. The objective of this study is to compare the accuracy of estimating dental age versus chronological age using the Nolla and Demirjian methods in a Spanish population. A final sample of 2641 panoramic X-rays corresponding to Spanish patients (1322 males and 1319 females) between 7-21 years of age was analyzed. Dental age was assessed using the Nolla and Demirjian methods, establishing comparisons with mean chronological age based on the Student t-test for paired samples, followed by the generation of a linear regression model. Both methods showed slight discrepancy between dental and chronological age. On examining the reproducibility of the Nolla and Demirjian methods, technical errors of 0.84% and 0.62%, respectively, were observed. On average, the Nolla method was found to estimate an age 0.213years younger than the chronological age, while the Demirjian method estimated an age 0.853years older than the chronological age. Linear combination of the mean Nolla and Demirjian estimates increased the predictive capacity to 99.2%. In conclusion the Nolla and Demirjian methods were found to be accurate in estimating chronological age from dental age in a Spanish population. The error

  14. The effect of chronological age and gender on the development of sprint performance during childhood and puberty.

    Science.gov (United States)

    Papaiakovou, Georgios; Giannakos, Athanasios; Michailidis, Charalampos; Patikas, Dimitrios; Bassa, Eleni; Kalopisis, Vassilios; Anthrakidis, Nikolaos; Kotzamanidis, Christos

    2009-12-01

    The purpose of the present study was to examine the effect of chronological age and gender on speed development during different sprinting phases in children and adolescents of both genders. The sample consisted of 360 sedentary pupils aged between 7 and 18 years, with 15 pupils representing each subgroup. The 30-m sprint speed was measured with photocells every 10 m. According to the results, boys and girls showed a gradual improvement in running speed during each sprint phase. The 18-year-old boys had significantly higher sprint speed in all measured distances compared to the 15-year-old or younger boys (p sprint. Furthermore, the performance on each sprint phase is uniformly affected by the chronological age. Boys run faster than girls in all running phases, and the span between genders increases after the age of 15 years. It is useful that coaches take these findings into consideration when evaluating children in sprint performance.

  15. Predictors of Indicators of body adiposity by chronological and biological age in children and adolescents residing in southern Chile

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    Fernando Alvear

    2017-12-01

    Full Text Available Introduction: The aims of this study were to identify the skin folds that predict the indicators of body adiposity (Body Mass Index [BMI] and waist circumference [CC], as well as to analyze if the indicators of body adiposity should be evaluated by chronological and/or biological age. Material and Methods: 131 children and adolescents (76 men and 55 women were studied. The age range ranged between 6.0 and 14.9 years. Weight, standing height, sitting height, waist circumference were evaluated. The BMI and the peak growth rate years were calculated. The nutritional status categories were determined by BMI and CC according to the cut-off points of the CDC-2012. Results: The four folds used (tricipital, bicipital, suprailiac and calf explained the BMI from 38 to 58% in men and women from 38 to 72%. The power of explanation for CC in men was 30 to 56% and in women from 27 to 53%. The chronological age explained the BMI and CC in men from 0.08 to 37% and in women from 15 to 17%. The biological age explained BMI and CC in men from 11 to 44% and in women from 21 to 24%. Conclusions: The suprailiac fold appears as the best predictor of BMI and CC in both sexes. The analysis of both indicators must be carried out by biological age rather than by chronological age.

  16. Staging of third molar development in relation to chronological age of 5-16 year old Indian children.

    Science.gov (United States)

    Hegde, Sapna; Patodia, Akash; Dixit, Uma

    2016-12-01

    The usefulness of the developmental status of the third molar has been studied in assessment of the chronological age of adolescents in whom the development of the other permanent teeth is nearly complete. However, little is known about the timing and pattern of third-molar development in the Indian population. This study aimed to stage the third molar development in relation to chronological age of 5-16year old Indian children. In this cross-sectional observational study, the status of third molar development in relation to chronological age of 1139 Indian children aged 5-16 years was evaluated radiographically, using Orhan's modification of Demirjian's method. The frequency of occurrence of the third molars varied from 47% to 70%. Crypt formation, crown completion and root completion occurred as early as 5.4, 8.7 and 15.0 years, respectively. No significant differences based on gender or side were observed in third-molar development (p>0.05). For most stages, maxillary third molars were slightly more advanced than their mandibular counterparts (p>0.05). Considering the high degree of variability observed in third molar genesis and development, the usefulness of this tooth in age determination studies may be very limited in the age group studied. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Chronologic age and skeletal maturation of the cervical vertebrae and hand-wrist: is there a relationship?

    Science.gov (United States)

    Uysal, Tancan; Ramoglu, Sabri Ilhan; Basciftci, Faruk Ayhan; Sari, Zafer

    2006-11-01

    The aims of this study were (1) to investigate the relationship between chronologic age and maturation of cervical vertebrae, (2) to identify the relationship between chronologic age and maturation stage evaluated by hand-wrist radiographs, and (3) to determine whether the maturation of cervical vertebrae correlates with maturation indicated by hand-wrist radiographs in a Turkish population. The samples were derived from lateral cephalometric and hand-wrist radiographs of 503 subjects (213 male, 290 female; ages, 5.3-24.1 years). Cervical vertebral development was evaluated by the method of Hassel and Farman. Skeletal maturation of each hand-wrist radiograph was determined according to the method described by Björk and Grave, and Brown's system. The Spearman rank-order correlation coefficients were estimated separately for males and females to measure the relationships among chronologic age, cervical vertebral maturation, and the skeletal maturation measured at the hand-wrist. The Spearman correlation coefficients were 0.72 (P cervical vertebrae skeletal maturation, and 0.79 (P maturation via hand-wrist radiographs. The correlation coefficient between hand-wrist and cervical-vertebrae maturation was 0.86 (P cervical-vertebrae maturation stages are clinically useful maturity indicators of the pubertal growth period Turkish subjects.

  18. A reference relative time-scale as an alternative to chronological age for cohorts with long follow-up.

    Science.gov (United States)

    Hurley, Margaret Anne

    2015-01-01

    Epidemiologists have debated the appropriate time-scale for cohort survival studies; chronological age or time-on-study being two such time-scales. Importantly, assessment of risk factors may depend on the choice of time-scale. Recently, chronological or attained age has gained support but a case can be made for a 'reference relative time-scale' as an alternative which circumvents difficulties that arise with this and other scales. The reference relative time of an individual participant is the integral of a reference population hazard function between time of entry and time of exit of the individual. The objective here is to describe the reference relative time-scale, illustrate its use, make comparison with attained age by simulation and explain its relationship to modern and traditional epidemiologic methods. A comparison was made between two models; a stratified Cox model with age as the time-scale versus an un-stratified Cox model using the reference relative time-scale. The illustrative comparison used a UK cohort of cotton workers, with differing ages at entry to the study, with accrual over a time period and with long follow-up. Additionally, exponential and Weibull models were fitted since the reference relative time-scale analysis need not be restricted to the Cox model. A simulation study showed that analysis using the reference relative time-scale and analysis using chronological age had very similar power to detect a significant risk factor and both were equally unbiased. Further, the analysis using the reference relative time-scale supported fully-parametric survival modelling and allowed percentile predictions and mortality curves to be constructed. The reference relative time-scale was a viable alternative to chronological age, led to simplification of the modelling process and possessed the defined features of a good time-scale as defined in reliability theory. The reference relative time-scale has several interpretations and provides a unifying

  19. Age and dynamics of the Namib Sand Sea: A review of chronological evidence and possible landscape development models

    Science.gov (United States)

    Stone, A. E. C.

    2013-06-01

    The Namib Sand Sea constitutes a major physiographic feature of the Namib Desert on the west of Namibia, covering a 50-160 km wide region of the coast between Lüderitz and Walvis Bay. It is widely considered to be one of the oldest desert regions, with a Tertiary-aged fossil desert underlying the modern sand sea. The sand sea has been well studied, benefiting from the presence of the Gobabeb Training and Research Centre during the past 50 years. Whilst much is understood about its sediments and geomorphology, it is only recently that new chronological information, using cosmogenic-nuclide burial dating and optically stimulated luminescence dating have offered new insights, and this calls for an updated review of the age and landscape development of the sand sea. This assessment of the geomorphological and Quaternary dynamics of the region is complemented by developments in the description and analysis of sediment composition. New age control from cosmogenic dating indicates that the sand sea is in excess of a million years old. Initial data from luminescence dating yields depositional ages for dune sediments from three broad areas of the sand sea that include MIS 5, later in the Pleistocene around the Last Glacial Maximum and the Holocene, although it is not expected that these will be the only, or discrete age groupings. Detailed dating and application of ground penetrating radar in the far northern reaches reveals extensive dune migration and deposition during the Holocene. It is important to stress that the upper limit of luminescence dating here is about ˜200 ka (depending on the environmental dose rate of the site) and that migration and reworking of dunes resets the luminescence signal (so what is recorded is(are) the last phase(s) of preserved sediment accumulation). Whilst there are three potential sources of material for the Namib Sand Sea (reworked Tsondab Sandstone (TSS), material from the Great Escarpment derived by rivers and water and wind

  20. An in vivo study on brain microstructure in biological and chronological ageing

    DEFF Research Database (Denmark)

    Altmann-Schneider, Irmhild; de Craen, Anton J M; van den Berg-Huysmans, Annette A

    2015-01-01

    phenotype of familial longevity. Moreover, we aimed to describe cerebral ageing effects on MTI parameters in an elderly cohort. All subjects were included from the Leiden Longevity Study and underwent 3 Tesla MTI of the brain. In total, 183 offspring of nonagenarian siblings, who are enriched for familial...... and superior region of the corona radiata (p age (p amygdala, caudate nucleus and putamen brain phenotype of human familial longevity is - at a mean age of 66......This study aimed to investigate whether magnetization transfer imaging (MTI) parameters of cortical gray and white matter and subcortical gray matter structures differ between subjects enriched for human familial longevity and control subjects to provide a thorough description of the brain...

  1. Cerebral blood flow and oximetry response to blood transfusion in relation to chronological age in preterm infants.

    Science.gov (United States)

    Banerjee, J; Leung, T S; Aladangady, N

    2016-06-01

    Preterm infants frequently receive blood transfusion (BT) and the aim of this study was to measure the effect of BT on cerebral blood flow and oxygenation in preterm infants in relation to chronological age. Preterm infants undergoing intensive care recruited to three chronological age groups: 1 to 7 (Group 1; n=20), 8 to 28 (Group 2; n=21) & ≥29days of life (Group 3; n=18). Pre and post-BT anterior cerebral artery (ACA) time averaged mean velocity (TAMV) and superior vena cava (SVC) flow were measured. Cerebral Tissue Haemoglobin Index (cTHI) and Oxygenation Index (cTOI) were measured from 15-20min before to 15-20min post-BT using NIRS. Vital parameters and blood pressure were measured continuously. Mean BP increased significantly, and there was no significant change in vital parameters following BT. Pre-BT ACA TAMV was higher in Group 2 and 3 compared to Group 1 (pBlood transfusion increased cTOI and cTHI and decreased ACA TAMV in all groups. PDA had no impact on the baseline cerebral oximetry and blood flow as well as changes following blood transfusion. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Middle and Later Stone Age chronology of Kisese II rockshelter (UNESCO World Heritage Kondoa Rock-Art Sites), Tanzania

    Science.gov (United States)

    Ranhorn, Kathryn L.; Kwekason, Amandus; Alex, Bridget; Laird, Myra F.; Marean, Curtis W.; Niespolo, Elizabeth; Nivens, Joelle; Mabulla, Audax Z. P.

    2018-01-01

    The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths, the recurrent use of red ochre, and >5,000 ostrich eggshell beads and bead fragments. Twenty-nine radiocarbon dates on ostrich eggshell carbonate make Kisese II one of the most robust chronological sequences for understanding archaeological change over the last ~47,000 years in East Africa. In particular, ostrich eggshell beads and backed microliths appear by 46–42 ka cal BP and occur throughout overlying Late Pleistocene and Holocene strata. Changes in lithic technology suggest an MSA/LSA transition that began 39–34.3 ka, with typical LSA technologies in place by the Last Glacial Maximum. The timing of these changes demonstrates the time-transgressive nature of behavioral innovations often linked to the origins of modern humans, even within a single region of Africa. PMID:29489827

  3. Middle and Later Stone Age chronology of Kisese II rockshelter (UNESCO World Heritage Kondoa Rock-Art Sites), Tanzania.

    Science.gov (United States)

    Tryon, Christian A; Lewis, Jason E; Ranhorn, Kathryn L; Kwekason, Amandus; Alex, Bridget; Laird, Myra F; Marean, Curtis W; Niespolo, Elizabeth; Nivens, Joelle; Mabulla, Audax Z P

    2018-01-01

    The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths, the recurrent use of red ochre, and >5,000 ostrich eggshell beads and bead fragments. Twenty-nine radiocarbon dates on ostrich eggshell carbonate make Kisese II one of the most robust chronological sequences for understanding archaeological change over the last ~47,000 years in East Africa. In particular, ostrich eggshell beads and backed microliths appear by 46-42 ka cal BP and occur throughout overlying Late Pleistocene and Holocene strata. Changes in lithic technology suggest an MSA/LSA transition that began 39-34.3 ka, with typical LSA technologies in place by the Last Glacial Maximum. The timing of these changes demonstrates the time-transgressive nature of behavioral innovations often linked to the origins of modern humans, even within a single region of Africa.

  4. Retrieving chronological age from dental remains of early fossil hominins to reconstruct human growth in the past.

    Science.gov (United States)

    Dean, M Christopher

    2010-10-27

    A chronology of dental development in Pan troglodytes is arguably the best available model with which to compare and contrast reconstructed dental chronologies of the earliest fossil hominins. Establishing a time scale for growth is a requirement for being able to make further comparative observations about timing and rate during both dento-skeletal growth and brain growth. The absolute timing of anterior tooth crown and root formation appears not to reflect the period of somatic growth. In contrast, the molar dentition best reflects changes to the total growth period. Earlier initiation of molar mineralization, shorter crown formation times, less root length formed at gingival emergence into functional occlusion are cumulatively expressed as earlier ages at molar eruption. Things that are similar in modern humans and Pan, such as the total length of time taken to form individual teeth, raise expectations that these would also have been the same in fossil hominins. The best evidence there is from the youngest fossil hominin specimens suggests a close resemblance to the model for Pan but also hints that Gorilla may be a better developmental model for some. A mosaic of great ape-like features currently best describes the timing of early hominin dental development.

  5. A New Chronology for Rhafas, Northeast Morocco, Spanning the North African Middle Stone Age through to the Neolithic.

    Directory of Open Access Journals (Sweden)

    Nina Doerschner

    Full Text Available Archaeological sites in northern Africa provide a rich record of increasing importance for the origins of modern human behaviour and for understanding human dispersal out of Africa. However, the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb, and their relationship to local environmental conditions, remain poorly understood. The cave of Rhafas (northeast Morocco provides valuable chronological information about cultural changes in the Maghreb during the Palaeolithic due to its long stratified archaeological sequence comprising Middle Stone Age (MSA, Later Stone Age (LSA and Neolithic occupation layers. 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 recently excavated section on the terrace in front of the cave entrance. We hereby provide a revised chronostratigraphy for the archaeological sequence at the site. We combine these results with geological and sedimentological multi-proxy investigations to gain insights into site formation processes and the palaeoenvironmental record of the region. The older sedimentological units at Rhafas were deposited between 135 ka and 57 ka (MIS 6 -MIS 3 and are associated with the MSA technocomplex. Tanged pieces start to occur in the archaeological layers around 109 ka, which is consistent with previously published chronological data from the Maghreb. A well indurated duricrust indicates favourable climatic conditions for the pedogenic cementation by carbonates of sediment layers at the site after 57 ka. Overlying deposits attributed to the LSA technocomplex yield ages of ~21 ka and ~15 ka, corresponding to the last glacial period, and fall well within the previously established occupation phase in the Maghreb. The last occupation phase at Rhafas took place during the Neolithic and is dated to ~7.8 ka.

  6. A New Chronology for Rhafas, Northeast Morocco, Spanning the North African Middle Stone Age through to the Neolithic.

    Science.gov (United States)

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

    Archaeological sites in northern Africa provide a rich record of increasing importance for the origins of modern human behaviour and for understanding human dispersal out of Africa. However, the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb), and their relationship to local environmental conditions, remain poorly understood. The cave of Rhafas (northeast Morocco) provides valuable chronological information about cultural changes in the Maghreb during the Palaeolithic due to its long stratified archaeological sequence comprising Middle Stone Age (MSA), Later Stone Age (LSA) and Neolithic occupation layers. 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 recently excavated section on the terrace in front of the cave entrance. We hereby provide a revised chronostratigraphy for the archaeological sequence at the site. We combine these results with geological and sedimentological multi-proxy investigations to gain insights into site formation processes and the palaeoenvironmental record of the region. The older sedimentological units at Rhafas were deposited between 135 ka and 57 ka (MIS 6 -MIS 3) and are associated with the MSA technocomplex. Tanged pieces start to occur in the archaeological layers around 109 ka, which is consistent with previously published chronological data from the Maghreb. A well indurated duricrust indicates favourable climatic conditions for the pedogenic cementation by carbonates of sediment layers at the site after 57 ka. Overlying deposits attributed to the LSA technocomplex yield ages of ~21 ka and ~15 ka, corresponding to the last glacial period, and fall well within the previously established occupation phase in the Maghreb. The last occupation phase at Rhafas took place during the Neolithic and is dated to ~7.8 ka.

  7. High-resolution chronology for deglaciation of the Patagonian Ice Sheet at Lago Buenos Aires (46.5°S) revealed through varve chronology and Bayesian age modelling

    Science.gov (United States)

    Bendle, Jacob M.; Palmer, Adrian P.; Thorndycraft, Varyl R.; Matthews, Ian P.

    2017-12-01

    Glaciolacustrine varves offer the potential to construct continuous, annually-resolved chronologies for ice-sheet deglaciation, and improved understanding of glacier retreat dynamics. This paper investigates laminated glaciolacustrine sediments deposited around the waning margins of the Patagonian Ice Sheet, following the local Last Glacial Maximum (LGM). Detailed macro- and microfacies analyses confirm an annual (varve) structure within these sediments. The correlation of annual layers (varves) across five sites in eastern Lago Buenos Aires yields a 994 ± 36 varve-year (vyr) chronology and thickness record. The floating chronology has been anchored to the calendar-year timescale through identification of the Ho tephra (17,378 ± 118 cal a BP) in the varve sequences. Using a Bayesian age model to integrate the new varve chronology with published moraine ages, the onset of deglaciation at 46.5°S is dated to 18,086 ± 214 cal a BP. New age estimates for deglacial events are combined with high-resolution analysis of varve thickness trends, and new lithostratigraphic data on ice-margin position(s), to reconstruct ice-margin retreat rates for the earliest ca. 1000 years of ice-sheet demise. Glacier retreat rates were moderate (5.3-10.3 m yr-1) until 17,322 ± 115 cal a BP, but subsequently accelerated (15.4-18.0 m yr-1). Sustained influxes of ice-rafted debris (IRD) after 17,145 ± 122 cal a BP suggest retreat rates were enhanced by calving after ice contracted into deeper lake waters. Ice persisted in eastern Lago Buenos Aires until at least 16,934 ± 116 cal a BP, after which the glacier started to retreat towards the Patagonian mountains.

  8. A comparison of cervical vertebral maturation assessment of skeletal growth stages with chronological age in Thai between cleft lip and palate and non-cleft patients.

    Science.gov (United States)

    Pisek, Poonsak; Godfrey, Keith; Manosudprasit, Montian; Wangsrimongkol, Tasanee; Leelasinjaroen, Pornnapha

    2013-09-01

    (1) To search for any difference in chronological age related to stages of the cervical vertebral maturation index stages (CVMIs) comparing groups of cleft lip and palate (CLP) and non-cleft (non-CLP) subjects; (2) To investigate the relationship between chronological age and CVMIs in both groups of subjects. Cervical vertebrae C2, C3, C4 were assessed on 1,549 cephalometric films (503 CLP films, 1,046 non-CLP films of subjects aged 5 to 18 years) using Hassel and Farman's method. T-tests showed mean chronological ages of CVMIs 2, 3 and 6 were different at p = 0.001, 0.024 and 0.016, respectively. CVMIs 1, 4 and 5 showed no significant differences. The CLP group achieved each CVMI score one year ahead of the non-CLP group, except for CVMI 4. Spearman's rank order correlations were r = 0.80 (95% CI: 0.76-0.83) for CLP, and 0.77 (95% CI: 0.74-0.79) for non-CLP. CLP subjects tended to have a slightly advanced growth compared with non-CLP subjects. A high correlation coefficient was found between chronological age and cervical vertebral skeletal maturation.

  9. Lunar chronology as determined from the radiometric ages of returned lunar samples

    International Nuclear Information System (INIS)

    Schaeffer, O.A.

    1977-01-01

    Arguments based on radiometric age determination measurements are presented which lead to the conclusion that Imbrium ejecta probably dominate most lunar highland samples and that it seems possible to date several major basins at times considerably older than 3.9 Ga ago. A complete picture of the ages of highland rocks is considered by using K-Ar method results. (U.K.)

  10. Correlación entre las edades cronológica y ósea en pacientes de ortodoncia Correlation between the chronological and bone ages in orthodontics patients

    Directory of Open Access Journals (Sweden)

    Gladia Toledo Mayarí

    2011-03-01

    Full Text Available Nos propusimos determinar la edad ósea según sexo y edad cronológica e identificar la relación existente entre las edades cronológica y ósea, en los pacientes estudiados. Se realizó un estudio descriptivo y transversal en un universo constituido por todos los niños y adolescentes tributarios de tratamiento ortodóncico, que ingresaron en la Clínica de Ortodoncia de la Facultad de Estomatología de la Universidad de Ciencias Médicas de La Habana, en el periodo de enero de 2004 a diciembre de 2006. El grupo etáreo se encontraba entre 8 y 16 años, de donde se seleccionó una muestra de 150 pacientes, mediante un muestreo por cuotas. A cada paciente se le realizó una radiografía de la mano izquierda, donde se determinó la edad ósea, a través del método de Tanner-Whitehouse 2 (TW2 y se calculó la correlación entre la edad ósea y la cronológica a través del coeficiente de correlación lineal de Pearson. Se encontraron correlaciones altas muy significativas entre las edades cronológica y ósea, en ambos sexos; sexo femenino r= 0,977 y masculino r= 0,983 (pTo determine the bone age according to the sex and chronologic age and to identify the relation between the chronologic and bone ages in study patients. A cross-sectional and descriptive study was conducted in a universe including all children and adolescents needing orthodontics treatment admitted in the Orthodontics Clinic of the Stomatology Faculty of the Higher Institute of Medical Sciences (HIMS-Habana from January, 2004 to December, 2006 aged between 8 and 16 selecting a sample including 150 patients by admission sampling, each patient undergoes a left hand radiography to determine the bone age by Tanner-Whitehouse 2 method (TW2 estimating the correlation between the bone age and chronologic one trough Pearson linear correlation coefficient. There were high and very significant correlations between the bone ages and the chronologic one in both sexes, female sex r= 0

  11. Effect of photoaging on skin test response to histamine independent of chronologic age.

    Science.gov (United States)

    King, Monroe J; Phillips, Sharon E; Lockey, Richard F

    2014-12-01

    Skin prick-puncture test responses to histamine on the upper back and forearms in older individuals are frequently small or absent but are often present or larger when repeated on the lower back. To determine whether photoaging or natural aging causes a smaller response to a prick-puncture skin test. Prick-puncture skin tests to histamine were performed on sun-exposed and sun-protected areas in younger (n = 61, aged 20-50 years) and older (n = 63, aged 60-87 years) adult volunteers. The skin was scored for photoaging by physical examination, and coloration was measured by a colorimeter. Large variation of photoaging occurred within age groups. Histamine wheals and flare were not different between the 2 age groups, but those adults with the greatest photoaging had smaller histamine wheals and flare on the upper back, with a trend for smaller flares on the volar aspect of the forearms and lower back. There was marked variability in response to histamine within individual adults, depending on the locale of the tests. Photoaging, but not age alone, is associated with a smaller response to histamine in sun-exposed areas. Before prick-puncture skin tests are performed, the skin should be examined for sun damage, and a sun-protected area should be selected; in vitro allergy testing may be substituted if there is no sun-protected skin area. Copyright © 2014 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  12. Experimental evaluation of work capacity as related to chronological and physiological aging.

    Science.gov (United States)

    1963-09-01

    Research statistics has establish the fact that physical work capacity declines as a consequence of aging. The question has been raised, however, if this decline is the inevitable result of senescence or merely due to change in living habits. Great n...

  13. College Students' Chronological Age Predicts Marital Happiness Regardless of Length of Marriage

    Science.gov (United States)

    Weinstein, Lawrence; Powers, Justina; Laverghetta, Antonio

    2010-01-01

    A revised version of the Quality Marriage Index (QMI) was used to examine demographic correlates of marital satisfaction. We administered the revised QMI to a sample of college students and found a significant positive correlation between age and relationship satisfaction. We suggest that this increase in relationship satisfaction could be due to…

  14. Chromatin Modifications as Determinants of Muscle Stem Cell Quiescence and Chronological Aging

    Directory of Open Access Journals (Sweden)

    Ling Liu

    2013-07-01

    Full Text Available The ability to maintain quiescence is critical for the long-term maintenance of a functional stem cell pool. To date, the epigenetic and transcriptional characteristics of quiescent stem cells and how they change with age remain largely unknown. In this study, we explore the chromatin features of adult skeletal muscle stem cells, or satellite cells (SCs, which reside predominantly in a quiescent state in fully developed limb muscles of both young and aged mice. Using a ChIP-seq approach to obtain global epigenetic profiles of quiescent SCs (QSCs, we show that QSCs possess a permissive chromatin state in which few genes are epigenetically repressed by Polycomb group (PcG-mediated histone 3 lysine 27 trimethylation (H3K27me3, and a large number of genes encoding regulators that specify nonmyogenic lineages are demarcated by bivalent domains at their transcription start sites (TSSs. By comparing epigenetic profiles of QSCs from young and old mice, we also provide direct evidence that, with age, epigenetic changes accumulate and may lead to a functional decline in quiescent stem cells. These findings highlight the importance of chromatin mapping in understanding unique features of stem cell identity and stem cell aging.

  15. Radiographic evaluation of third-molar development in relation to the chronological age of Turkish children in the southwest Eastern Anatolia region.

    Science.gov (United States)

    Karataş, Orhan H; Öztürk, Fırat; Dedeoğlu, Numan; Çolak, Cemil; Altun, Oğuzhan

    2013-10-10

    To study the chronological age of third-molar mineralisation of Turkish children from the southwest Eastern Anatolia region, the Demirjian staging method was used to determine the stage of the mineralisation of four third molars (18, 28, 38 and 48) and to compare third-molar development by sex and age with the results of previous studies. The study comprised 832 Turkish children from the southwest Eastern Anatolia region aged 6-16 years based on radiological evidence from digital orthopantomograms. The mean age of the 832 patients was 11.03±1.98 years, with 424 males (mean age, 10.97±1.97) and 408 females (mean age, 11.09±2.00). The orthopantomograms were scored by two observers. The Wilcoxon matched-pairs signed-rank test used to assess intra- and inter-observer assessment revealed strong agreement between both observers' measurements. Statistical analysis of the association between sex and age was performed with the Mann-Whitney U-test and the Wilcoxon test. Regression analysis was performed to obtain regression formulae for calculating the dental and the chronological age. The statistical analysis showed a strong correlation between age and third-molar development in males (R(2)=0.61) and females (R(2)=0.63). New equations (age=7.49+0.69, development stage (DS) 38+0.70, DS18) were derived for estimation of the chronological age. The results showed that there was no significant difference in mineralisation between 18 and 28 and 38 and 48 in males or females. For both sexes, the dental age was lower than the chronological age. Males reached the developmental stages earlier than females. In the whole population, the boys' and the girls' dental ages were 0.84 years and 0.16 years earlier, respectively, than their chronological ages. The use of third-molar teeth as a developmental marker is suitable, particularly when comparing the obtained standard deviation with other skeletal-age calculation techniques. Copyright © 2013 Elsevier Ireland Ltd. All rights

  16. Retrieving chronological age from dental remains of early fossil hominins to reconstruct human growth in the past

    OpenAIRE

    Dean, M. Christopher

    2010-01-01

    A chronology of dental development in Pan troglodytes is arguably the best available model with which to compare and contrast reconstructed dental chronologies of the earliest fossil hominins. Establishing a time scale for growth is a requirement for being able to make further comparative observations about timing and rate during both dento-skeletal growth and brain growth. The absolute timing of anterior tooth crown and root formation appears not to reflect the period of somatic growth. In c...

  17. Kex1 protease is involved in yeast cell death induced by defective N-glycosylation, acetic acid, and chronological aging.

    Science.gov (United States)

    Hauptmann, Peter; Lehle, Ludwig

    2008-07-04

    N-glycosylation in the endoplasmic reticulum is an essential protein modification and highly conserved in evolution from yeast to humans. The key step of this pathway is the transfer of the lipid-linked core oligosaccharide to the nascent polypeptide chain, catalyzed by the oligosaccharyltransferase complex. Temperature-sensitive oligosaccharyltransferase mutants of Saccharomyces cerevisiae at the restrictive temperature, such as wbp1-1, as well as wild-type cells in the presence of the N-glycosylation inhibitor tunicamycin display typical apoptotic phenotypes like nuclear condensation, DNA fragmentation, phosphatidylserine translocation, caspase-like activity, and reactive oxygen species accumulation. Since deletion of the yeast metacaspase YCA1 did not abrogate this death pathway, we postulated a different proteolytic process to be responsible. Here, we show that Kex1 protease is involved in the programmed cell death caused by defective N-glycosylation. Its disruption decreases caspase-like activity, production of reactive oxygen species, and fragmentation of mitochondria and, conversely, improves growth and survival of cells. Moreover, we demonstrate that Kex1 contributes also to the active cell death program induced by acetic acid stress or during chronological aging, suggesting that Kex1 plays a more general role in cellular suicide of yeast.

  18. The Effects of Chronological Age on the Cellular Mechanics of Human Dermal Fibroblasts

    Science.gov (United States)

    Pan, Z.; Hung, V.; Kambhampati, S.; Ge, S. R.; Rafailovich, M.; Ghosh, K.; Clark, R.; Liu, Y. J.; Nakamura, T.; Shu, X. Z.; Prestwich, G.

    2006-03-01

    It is often observed that older people display diminished wound healing abilities. Understanding of this phenomenon is important for many in vivo applications of tissue engineering. In this study, the cell mechanics of dermal fibroblasts from 25, 40 and 84 years old female subjects were compared. These cells were cultured on functionalized hyaluronic acid hydrogel substrates which emulated physiological conditions in dermal tissue. The deformation of the substrate caused by cellular traction forces was detected by tracing the displacement of fluorescent beads embedded in the substrate using Digital Image Speckle Correlation. Then cellular traction forces were quantitatively determined by Finite Element Method in a linear elastic model with a high spatial resolution. These results were correlated with auxiliary measurements of substrate modulus, cell modulus and migration. We found that with increasing age, the magnitude of the cellular traction forces diminished. Similarly, the ability of the cells to adapt to changes in the mechanical properties of their environment and migrate was also impaired. The interrelationship between these factors and wound healing will be discussed. This work is supported by NSF- MRSEC program.

  19. A Chronological Perspective on the Acheulian and Its Transition to the Middle Stone Age in Southern Africa: The Question of the Fauresmith

    Science.gov (United States)

    Herries, Andy I. R.

    2011-01-01

    An understanding of the age of the Acheulian and the transition to the Middle Stone Age in southern Africa has been hampered by a lack of reliable dates for key sequences in the region. A number of researchers have hypothesised that the Acheulian first occurred simultaneously in southern and eastern Africa at around 1.7-1.6 Ma. A chronological evaluation of the southern African sites suggests that there is currently little firm evidence for the Acheulian occurring before 1.4 Ma in southern Africa. Many researchers have also suggested the occurrence of a transitional industry, the Fauresmith, covering the transition from the Early to Middle Stone Age, but again, the Fauresmith has been poorly defined, documented, and dated. Despite the occurrence of large cutting tools in these Fauresmith assemblages, they appear to include all the technological components characteristic of the MSA. New data from stratified Fauresmith bearing sites in southern Africa suggest this transitional industry maybe as old as 511–435 ka and should represent the beginning of the MSA as a broad entity rather than the terminal phase of the Acheulian. The MSA in this form is a technology associated with archaic H. sapiens and early modern humans in Africa with a trend of greater complexity through time. PMID:21785711

  20. Relationship between chronological and bone ages and pubertal stage of breasts with bone biomarkers and bone mineral density in adolescents.

    Science.gov (United States)

    Fortes, Cristina Maria Teixeira; Goldberg, Tamara Beres Lederer; Kurokawa, Cilmery Suemi; Silva, Carla Cristiani; Moretto, Maria Regina; Biason, Talita Poli; Teixeira, Altamir Santos; Nunes, Hélio Rubens de Carvalho

    2014-01-01

    To study bone mineral density (BMD) in adolescent females according to five groups of chronological age (CA), bone age (BA), and breast development stage (B), and to correlate these parameters with plasma bone biomarkers (BB). This was a cross-sectional study performed in 101 healthy adolescent females between 10 and 20 years old. The study variables were: weight, height, body mass index (BMI), CA, B, BA, calcium intake, BMD, and BB. Osteocalcin (OC), bone alkaline phosphatase (BAP), and C-terminal telopeptide (S-CTx) were evaluated for BB. BMD was measured using dual energy X-ray absorptiometry (DXA). BMD in lumbar spine, proximal femur, and total body increased with age, and the respective observed averages were: in CA1 (10 years old), 0.631, 0.692, 0.798 g/cm(2); in CA2 (11 to 12 years old), 0.698, 0.763, 0.840 g/cm(2); in CA3 (13 to 14 years old), 0.865, 0.889, 0.972 g/cm(2); in CA4 (15 to 16 years old), 0.902, 0.922, 1.013 g/cm(2); and in CA5 (17 to 19 years old), 0.944, 0.929, 1.35 g/cm(2). These results showed significant differences between 13 and 14 years of age (CA3) or when girls reached the B3 stage (0.709, 0.832, 0.867 g/cm(2)). The highest median concentrations of BB were between 10 and 12 years of age when adolescents were in the B2-B3 (p<0.001). Median BB concentrations decreased in advanced BA and B. BB concentrations were positively correlated with the peak height velocity and negatively correlated with BMD in the study sites. Increased BMD and BB concentrations were observed in B3. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  1. Phenological development of East African highland banana involves trade-offs between physiological age and chronological age

    NARCIS (Netherlands)

    Taulya, G.; Asten, van P.J.A.; Leffelaar, P.A.; Giller, K.E.

    2014-01-01

    The phenology of East African highland banana (Musa acuminata AAA-EA, hereafter referred to as ‘highland banana’) is poorly understood. We tested three hypotheses: (1) the physiological age at flowering is independent of site effects, (2) there is no difference in threshold size at flowering between

  2. Extension of yeast chronological lifespan by methylamine.

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    Full Text Available BACKGROUND: Chronological aging of yeast cells is commonly used as a model for aging of human post-mitotic cells. The yeast Saccharomyces cerevisiae grown on glucose in the presence of ammonium sulphate is mainly used in yeast aging research. We have analyzed chronological aging of the yeast Hansenula polymorpha grown at conditions that require primary peroxisome metabolism for growth. METHODOLOGY/PRINCIPAL FINDINGS: The chronological lifespan of H. polymorpha is strongly enhanced when cells are grown on methanol or ethanol, metabolized by peroxisome enzymes, relative to growth on glucose that does not require peroxisomes. The short lifespan of H. polymorpha on glucose is mainly due to medium acidification, whereas most likely ROS do not play an important role. Growth of cells on methanol/methylamine instead of methanol/ammonium sulphate resulted in further lifespan enhancement. This was unrelated to medium acidification. We show that oxidation of methylamine by peroxisomal amine oxidase at carbon starvation conditions is responsible for lifespan extension. The methylamine oxidation product formaldehyde is further oxidized resulting in NADH generation, which contributes to increased ATP generation and reduction of ROS levels in the stationary phase. CONCLUSION/SIGNIFICANCE: We conclude that primary peroxisome metabolism enhanced chronological lifespan of H. polymorpha. Moreover, the possibility to generate NADH at carbon starvation conditions by an organic nitrogen source supports further extension of the lifespan of the cell. Consequently, the interpretation of CLS analyses in yeast should include possible effects on the energy status of the cell.

  3. Extension of Yeast Chronological Lifespan by Methylamine

    NARCIS (Netherlands)

    Kumar, Sanjeev; Lefevre, Sophie D.; Veenhuis, Marten; van der Klei, Ida J.

    2012-01-01

    Background: Chronological aging of yeast cells is commonly used as a model for aging of human post-mitotic cells. The yeast Saccharomyces cerevisiae grown on glucose in the presence of ammonium sulphate is mainly used in yeast aging research. We have analyzed chronological aging of the yeast

  4. The degree of premature hair graying as an independent risk marker for coronary artery disease: a predictor of biological age rather than chronological age.

    Science.gov (United States)

    Kocaman, Sinan Altan; Çetin, Mustafa; Durakoğlugil, Murtaza Emre; Erdoğan, Turan; Çanga, Aytun; Çiçek, Yüksel; Doğan, Sıtkı; Şahin, Ismail; Şatıroğlu, Omer; Bostan, Mehmet

    2012-09-01

    Age is the most important and uncorrectable coronary risk factor at the moment. The concept of measuring aging biologically rather than only chronologically may be of importance in clinical practice. Hair graying is the most apparent sign of biological aging in humans, yet its mechanism is largely unknown. Today, it is known that cardiovascular risk factors (CVRFs), especially in combination, cause premature atherosclerosis. In our opinion, premature hair graying or whitening may represent early atherosclerotic changes as a surrogate of host response to the CVRFs. In this study, we planned to investigate the relationship of hair graying with CVRFs and coronary atherosclerotic burden in order to determine whether it is an independent marker for coronary artery disease (CAD). The current study has a cross-sectional observational design. Two hundred and thirteen men who underwent coronary angiography with a suspicion of CAD were enrolled in the study. The patients were evaluated in terms of age, demographical properties and the CVRFs. Hair whitening score (HWS) was defined according to extent of gray/white hairs (1: pure black; 2: black>white; 3: black=white; 4: white>black; 5: pure white). Coronary atherosclerotic burden was assessed by the Gensini score. Analyses were performed in age-matched normal coronary arteries (NCA) and CAD groups. Linear and logistic regression analyses were used for the multivariate analyses of independent variables associated with hair greying. The CVRFs were higher in CAD group. Hair whitening score (2.7 ± 1.3 vs. 3.3 ± 1.2, p=0.002), hair losing score (1.2 ± 0.9 vs. 1.5 ± 1.0, p=0.038) and xanthelasma rate (24% vs. 45%, p=0.013) were also significantly different between NCA and CAD groups. Age (phair graying. In our study, we found that the degree of gray/white hairs is related to extent of CAD. Our findings also suggested that hair graying is a risk marker for CAD independent of age and other traditional risk factors. Biological age

  5. Concerning the chronology of Cimabue's oeuvre and the origin of pictorial depth in Italian painting of the later middle ages

    Directory of Open Access Journals (Sweden)

    Polzer Joseph

    2002-01-01

    Full Text Available A study devoted to the gradual emergence of pictorial depth in Cimabue's paintings, and how it applies, together with other factors, to the understanding of their sequential chronology. The conclusions reached underscore the vast difference in Cimabue 's conservative art and the exceptional naturalism of the evolving Life of Saint Francis mural cycle lining the lower nave walls in the upper church of San Francesco at Assisi.

  6. The fears, phobias and anxieties of children with autism spectrum disorders and Down syndrome: comparisons with developmentally and chronologically age matched children.

    Science.gov (United States)

    Evans, David W; Canavera, Kristin; Kleinpeter, F Lee; Maccubbin, Elise; Taga, Ken

    2005-01-01

    This study compared the fears and behavior problems of 25 children with an autism spectrum disorder (ASD), 43 children with Down syndrome (DS), 45 mental age (MA) matched children, and 37 chronologically age (CA) matched children. Children's fears, phobias, anxieties and behavioral problems were assessed using parent reports. Significant differences emerged across the diagnostic groups on a variety of fears. Children with ASD were reported to have more situation phobias and medical fears, but fewer fears of harm/injury compared to all other groups. The groups also differed in terms of the pattern of correlations between fears, phobias, anxieties and behavior problems. For children with ASD, fears, phobias and anxieties were closely related to problem behaviors, whereas fears, phobias, and anxieties were less related to behavioral symptoms for the other groups of subjects. Such findings suggest that children with ASD exhibit a distinct profile of fear and anxiety compared to other mental age and chronologically age-matched children, and these fears are related to the symptoms associated with ASD.

  7. Visual search performance in children rated as good or poor attenders: the differential impact of DAT1 genotype, IQ, and chronological age.

    Science.gov (United States)

    Cornish, K M; Wilding, J M; Hollis, C

    2008-03-01

    Attention-deficit/hyperactivity disorder (ADHD) is characterized by poor attention to detail, poor attention maintenance, and variability throughout task performance. The authors used a quantitative trait loci approach to assess the association between the dopamine transporter (DAT1) high-risk genotype, cognitive performance (visual search and vigilance), and ADHD symptoms in a community sample of boys 6-11 years of age. The potential confounding effects of IQ and chronological age were also investigated. Results demonstrate that accuracy in target detection, not speed, distinguishes poor attenders from good attenders. The authors speculate that the measure of performance (e.g., time and false alarms) may be critical in detecting attentional weaknesses. In contrast, DAT1 gene, known to be associated with the behavioral symptoms of ADHD, was unrelated to visual search or vigilance performance, although it was related to ADHD symptoms.

  8. New luminescence ages for the Galería Complex archaeological site: resolving chronological uncertainties on the acheulean record of the Sierra de Atapuerca, northern Spain.

    Science.gov (United States)

    Demuro, Martina; Arnold, Lee J; Parés, Josep M; Pérez-González, Alfredo; Ortega, Ana I; Arsuaga, Juan L; Bermúdez de Castro, José M; Carbonell, Eudald

    2014-01-01

    The archaeological karstic infill site of Galería Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range luminescence dating techniques, namely post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains, were applied to fossil-bearing sediments at Galería. The luminescence dating results are in good agreement with published chronologies derived using alternative radiometric dating methods (i.e., ESR and U-series dating of bracketing speleothems and combined ESR/U-series dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new luminescence ages are significantly (∼50%) younger than previously published polymineral thermoluminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galería deposits. The luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galería have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galería Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT

  9. Yeast AMID homologue Ndi1p displays respiration-restricted apoptotic activity and is involved in chronological aging.

    Science.gov (United States)

    Li, Wei; Sun, Libo; Liang, Qiuli; Wang, Juan; Mo, Weike; Zhou, Bing

    2006-04-01

    Apoptosis-inducing factor (AIF) and AIF-homologous mitochondrion-associated inducer of death (AMID) are both mitochondrial flavoproteins that trigger caspase-independent apoptosis. Phylogenetic analysis suggests that these two proteins evolutionarily diverge back from their common prokaryote ancestor. Compared with AIF, the proapoptotic nature of AMID and its mode of action are much less clarified. Here, we show that overexpression of yeast AMID homologue internal NADH dehydrogenase (NDI1), but not external NADH dehydrogenase (NDE1), can cause apoptosis-like cell death, and this effect can be repressed by increased respiration on glucose-limited media. This result indicates that the regulatory network of energy metabolism, in particular the cross-talk between mitochondria and the rest of the cell, is involved in Ndi1p-induced yeast cell apoptosis. The apoptotic effect of NDI1 overexpression is associated with increased production of reactive oxygen species (ROS) in mitochondria. In addition, NDI1 overexpression in sod2 background causes cell lethality in both fermentable and semifermentable media. Interruption of certain components in the electron transport chain can suppress the growth inhibition from Ndi1p overexpression. We finally show that disruption of NDI1 or NDE1 decreases ROS production and elongates the chronological life span of yeast, accompanied by the loss of survival fitness. Implication of these findings for Ndi1p-induced apoptosis is discussed.

  10. CLINICAL STUDY OF THE CHRONOLOGICAL CHANGES IN KNEE ALIGNMENT PATTERN IN NORMAL SOUTH-EAST NIGERIAN CHILDREN AGED BETWEEN 0 AND 5 YEARS

    Directory of Open Access Journals (Sweden)

    Ezeuko V.C

    2010-01-01

    Full Text Available The purpose of this study is to establish the chronological changes in knee alignment pattern in normal South-East Nigerian children aged between 0 and 5 years. A total number of 1450 subjects (680 males and 770 females were used for the study. The intercondylar/intermalleolar distances were measured using a vernier caliper with the subjects standing erect in anatomical position to determine straight knee, genu valgum and genu varum. The data was analysed with Microsoft Excel version 2007. The prevalence was presented as percentage (%.The result showed that the subjects have varum by the first year of life, prevalently genu valgum in type by the second year, valgum by the third year, neutral by the fourth and fifth year.

  11. Investigating the Victim Pseudomaturity Effect: How a Victim's Chronological Age and Dress Style Influences Attributions in a Depicted Case of Child Sexual Assault.

    Science.gov (United States)

    Rogers, Paul; Lowe, Michelle; Reddington, Katie

    2016-01-01

    Three-hundred and seven members of the UK public read a hypothetical child sexual abuse case in which the victim's chronological age (12 versus 15 years old) and dress style (sexualized versus nonsexualized) were experimentally manipulated before completing 22 assault severity and blame attribution items. It was predicted that the 15-year-old and the sexually dressed victim would be blamed more for her own abuse. In addition, males were expected to be more blaming generally, but especially of the older and/or sexually dressed victim. Results were generally in line with predictions, highlighting the role seemingly controllable victim characteristics play in blaming child sexual abuse victims. Findings are discussed in relation to defensive attributions, gender stereotyping and the newly suggested victim pseudomaturity effect. Criminal justice, victim welfare, and rape myth implications together with methodological issues and ideas for future research work are also considered.

  12. Extending PSA models including ageing and asset management - 15291

    International Nuclear Information System (INIS)

    Martorell, S.; Marton, I.; Carlos, S.; Sanchez, A.I.

    2015-01-01

    This paper proposes a new approach to Ageing Probabilistic Safety Assessment (APSA) modelling, which is intended to be used to support risk-informed decisions on the effectiveness of maintenance management programs and technical specification requirements of critical equipment of Nuclear Power Plants (NPP) within the framework of the Risk Informed Decision Making according to R.G. 1.174 principles. This approach focuses on the incorporation of not only equipment ageing but also effectiveness of maintenance and efficiency of surveillance testing explicitly into APSA models and data. This methodology is applied to a motor-operated valve of the auxiliary feed water system (AFWS) of a PWR. This simple example of application focuses on a critical safety-related equipment of a NPP in order to evaluate the risk impact of considering different approaches to APSA and the combined effect of equipment ageing and maintenance and testing alternatives along NPP design life. The risk impact of several alternatives in maintenance strategy is discussed

  13. Epiphyseal maturity indicators at the knee and their relationship to chronological age: results of an Irish population study.

    LENUS (Irish Health Repository)

    O'Connor, Jean E

    2013-09-01

    Skeletal maturation is divisible to three main components; the time of appearance of an ossification center, its change in morphology and time of fusion to a primary ossification center. With regard to the knee, the intermediate period between appearance and fusion of the ossification centers extends over a period of greater than 10 years. This study aims to investigate radiographically the age at which morphological changes of the epiphyses at the knee occur in a modern Irish population. Radiographs of 221 subjects (137 males; 84 females) aged 9-19 years were examined. Seven nonmetric indicators of maturity were assessed using criteria modified from the Roche, Wainer, and Thissen method and Pyle and Hoerr\\'s atlas of the knee. Reference charts are presented which display the timeline for each of the grades of development of the seven indicators. Mean age was found to increase significantly with successive grades of development of each of the seven indicators. A significant difference was noted between males and females at the same grade of development for six of the seven indicators. The narrowest age range reported for a single grade of development was 2.2 years for Grade 2 of development of the tibial tuberosity for males. The information on changing morphology of the epiphyses at the knee in the present study may provide an adjunct to methods used for evaluation of skeletal maturity before surgery for orthopedic disorders or to evaluate skeletal age in clinical scenarios where either delayed or precocious skeletal maturation is suspected.

  14. A radiographic study of permanent molar development in wild Virunga mountain gorillas of known chronological age from Rwanda.

    Science.gov (United States)

    Kralick, Alexandra E; Loring Burgess, M; Glowacka, Halszka; Arbenz-Smith, Keely; McGrath, Kate; Ruff, Christopher B; Chan, King Chong; Cranfield, Michael R; Stoinski, Tara S; Bromage, Timothy G; Mudakikwa, Antoine; McFarlin, Shannon C

    2017-05-01

    While dental development is important to life history investigations, data from wild known-aged great apes are scarce. We report on the first radiographic examination of dental development in wild Virunga mountain gorillas, using known-age skeletal samples recovered in Rwanda. In 43 individuals (0.0-14.94 years), we collected radiographs of mandibular molars, and where possible, cone beam CT scans. Molar crown and root calcification status was assessed using two established staging systems, and age prediction equations generated using polynomial regression. Results were compared to available data from known-age captive and wild chimpanzees. Mountain gorillas generally fell within reported captive chimpanzee distributions or exceeded them, exhibiting older ages at equivalent radiographic stages of development. Differences reflect delayed initiation and/or an extended duration of second molar crown development, and extended first and second molar root development, in mountain gorillas compared to captive chimpanzees. However, differences in the duration of molar root development were less evident compared to wild chimpanzees. Despite sample limitations, our findings extend the known range of variation in radiographic estimates of molar formation timing in great apes, and provide a new age prediction technique based on wild specimens. However, mountain gorillas do not appear accelerated in radiographic assessment of molar formation compared to chimpanzees, as they are for other life history traits. Future studies should aim to resolve the influence of species differences, wild versus captive environments, and/or sampling phenomena on patterns observed here, and more generally, how they relate to variation in tooth size, eruption timing, and developmental life history. © 2017 Wiley Periodicals, Inc.

  15. A New Chronology for the Bronze Age of Northeastern Thailand and Its Implications for Southeast Asian Prehistory.

    Science.gov (United States)

    Higham, Charles F W; Douka, Katerina; Higham, Thomas F G

    2015-01-01

    There are two models for the origins and timing of the Bronze Age in Southeast Asia. The first centres on the sites of Ban Chiang and Non Nok Tha in Northeast Thailand. It places the first evidence for bronze technology in about 2000 B.C., and identifies the origin by means of direct contact with specialists of the Seima Turbino metallurgical tradition of Central Eurasia. The second is based on the site of Ban Non Wat, 280 km southwest of Ban Chiang, where extensive radiocarbon dating places the transition into the Bronze Age in the 11th century B.C. with likely origins in a southward expansion of technological expertise rooted in the early states of the Yellow and Yangtze valleys, China. We have redated Ban Chiang and Non Nok Tha, as well as the sites of Ban Na Di and Ban Lum Khao, and here present 105 radiocarbon determinations that strongly support the latter model. The statistical analysis of the results using a Bayesian approach allows us to examine the data at a regional level, elucidate the timing of arrival of copper base technology in Southeast Asia and consider its social impact.

  16. Body mass index, chronological age and hormonal status are better predictors of biological skin age than arm skin autofluorescence in healthy women who have never smoked

    NARCIS (Netherlands)

    Randag, A. C.; Graaff, R.; Dreise, M. M.; Vierkoetter, A.; Werker, P. M. N.; Stenekes, M. W.

    2015-01-01

    Background As life expectancy is increasing and healthy ageing becomes more and more important, skin ageing is a growing topic of interest from both a medical and a commercial point of view. The urgency to unravel the causes of skin ageing is rising. However, there is a lack of objective, simple,

  17. 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.

  18. Beyond chronological age. Examining perceived future time and subjective health as age-related mediators in relation to work-related motivations and well-being

    NARCIS (Netherlands)

    Annet de Lange; Paul Jansen; Dorien Kooij; Josje Dikkers

    2013-01-01

    Since workforces across the world are aging, researchers and organizations need more insight into how and why occupational well-being, together with work-related attitudes and motivations, change with age. Lifespan theories point to subjective health and future time perspective (i.e. an individual's

  19. Beyond chronological age : Examining perceived future time and subjective health as age-related mediators in relation to work-related motivations and well-being

    NARCIS (Netherlands)

    Kooij, T.A.M.; de Lange, A.H.; Jansen, P.G.W.; Dikkers, J.S.E.

    2013-01-01

    Since workforces across the world are aging, researchers and organizations need more insight into how and why occupational well-being, together with work-related attitudes and motivations, change with age. Lifespan theories point to subjective health and future time perspective (i.e. an individual's

  20. Constructing deposition chronologies for peat deposits using radiocarbon dating

    Directory of Open Access Journals (Sweden)

    N. Piotrowska

    2011-06-01

    Full Text Available Radiocarbon dating is one of the main methods used to establish peat chronologies. This article reviews the basis of the method and its application to dating of peat deposits. Important steps in the radiocarbon dating procedure are described, including selection and extraction of material (and fractions for dating, chemical and physical preparation of media suitable for measurements, measurements of 14C activity or concentration, calculations, calibration of results and age-depth modelling.

  1. Appearance and chronology of Textile ceramics in the Middle and Upper Volga region: critical comparison of conventional 14C-, AMS- and typological chronologies

    Directory of Open Access Journals (Sweden)

    Lavento Mika T.

    2015-06-01

    Full Text Available The article offers a comparison of three different methods of chronology construction – conventional 14C (radiocarbon dating, AMS (accelerator mass-spectrometry dating and the so called typological chronology – to date the textile ceramics of the Bronze – Early Iron Age in the Northern Coniferous Zone of Europe, from the Upper and Middle Volga and Kama Rivers to the Baltic region and Scandinavia. The Textile Ceramics Culture (also known as “Net”, “Pseudo-textile”, “Spun-and-speckled” is often associated with a Finnish-speaking community from the Bronze – beginning of the Iron Age. The earliest date of the Textile Ceramics sites on the Middle Oka River is presumably considered to be the 18 th century BC. Datings of the reference sites in the Middle Volga region were fixed within the 15 th – 8 th centuries BC. Comparing these data with the AMS chronology available for the materials from Finland and Estonia, the authors conclude that appearance of the Textile Ceramics was almost synchronous in the Volga and the Baltic regions, although chronology of the early tradition of the Textile Ceramics seems to be different in these areas. The results of yet a small number of AMS dates should be treated only as preliminary. However, AMS-dating seems to be the most efficient tool for further refining of the Textile Ceramics chronology over a vast territory, including in the Volga region.

  2. 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)

  3. Chronology of early lunar crust

    International Nuclear Information System (INIS)

    Dasch, E.J.; Nyquist, L.E.; Ryder, G.

    1988-01-01

    The chronology of lunar rocks is summarized. The oldest pristine (i.e., lacking meteoritic contamination of admixed components) lunar rock, recently dated with Sm-Nd by Lugmair, is a ferroan anorthosite, with an age of 4.44 + 0.02 Ga. Ages of Mg-suite rocks (4.1 to 4.5 Ga) have large uncertainties, so that age differences between lunar plutonic rock suites cannot yet be resolved. Most mare basalts crystallized between 3.1 and 3.9 Ga. The vast bulk of the lunar crust, therefore, formed before the oldest preserved terrestrial rocks. If the Moon accreted at 4.56 Ga, then 120 Ma may have elapsed before lunar crust was formed

  4. Chronology and development of the Chalcolithic necropolis of Varna I

    Directory of Open Access Journals (Sweden)

    Raiko Krauß

    2018-01-01

    Full Text Available In the following paper, we present the main results of our now completed studies of the Varna I cemetery, based on the excavations undertaken by Ivan Ivanov in the years 1972–1991. The richness of the assemblages is singular in Old World prehistory. To tackle the question of its inter­nal, chronological development, we applied correspondence analysis (CA to a newly created database that includes the inventories of all presently known graves, symbolic burials and find de­posits. The rank order of the seriated inventories was used to establish a CA-based 14C-age model for wiggle matching. In combination with topographic observations and social network analysis (SNA, our studies provide a new understanding both of the chronological and spatial distribution of the graves and burial goods, as well as new insights into the social structure, gender roles, individual relation­ships and ritual practices of the Chalcolithic community.

  5. Microscopic age determination of human skeletons including an unknown but calculable variable

    DEFF Research Database (Denmark)

    Wallin, Johan Albert; Tkocz, Izabella; Kristensen, Gustav

    1994-01-01

    estimation, which includes the covariance matrix of four single equation residuals, improves the accuracy of age determination. The standard deviation, however, of age prediction remains 12.58 years. An experimental split of the data was made in order to demonstrate that the use of subgroups gives a false...

  6. Age correction in monitoring audiometry: method to update OSHA age-correction tables to include older workers.

    Science.gov (United States)

    Dobie, Robert A; Wojcik, Nancy C

    2015-07-13

    The US Occupational Safety and Health Administration (OSHA) Noise Standard provides the option for employers to apply age corrections to employee audiograms to consider the contribution of ageing when determining whether a standard threshold shift has occurred. Current OSHA age-correction tables are based on 40-year-old data, with small samples and an upper age limit of 60 years. By comparison, recent data (1999-2006) show that hearing thresholds in the US population have improved. Because hearing thresholds have improved, and because older people are increasingly represented in noisy occupations, the OSHA tables no longer represent the current US workforce. This paper presents 2 options for updating the age-correction tables and extending values to age 75 years using recent population-based hearing survey data from the US National Health and Nutrition Examination Survey (NHANES). Both options provide scientifically derived age-correction values that can be easily adopted by OSHA to expand their regulatory guidance to include older workers. Regression analysis was used to derive new age-correction values using audiometric data from the 1999-2006 US NHANES. Using the NHANES median, better-ear thresholds fit to simple polynomial equations, new age-correction values were generated for both men and women for ages 20-75 years. The new age-correction values are presented as 2 options. The preferred option is to replace the current OSHA tables with the values derived from the NHANES median better-ear thresholds for ages 20-75 years. The alternative option is to retain the current OSHA age-correction values up to age 60 years and use the NHANES-based values for ages 61-75 years. Recent NHANES data offer a simple solution to the need for updated, population-based, age-correction tables for OSHA. The options presented here provide scientifically valid and relevant age-correction values which can be easily adopted by OSHA to expand their regulatory guidance to

  7. Macromitophagy is a longevity assurance process that in chronologically aging yeast limited in calorie supply sustains functional mitochondria and maintains cellular lipid homeostasis

    Science.gov (United States)

    Burstein, Michelle T.; Koupaki, Olivia; Gomez-Perez, Alejandra; Levy, Sean; Pluska, Lukas; Mattie, Sevan; Rafeh, Rami; Iouk, Tatiana; Sheibani, Sara; Greenwood, Michael; Vali, Hojatollah; Titorenko, Vladimir I.

    2013-01-01

    Macromitophagy controls mitochondrial quality and quantity. It involves the sequestration of dysfunctional or excessive mitochondria within double-membrane autophagosomes, which then fuse with the vacuole/lysosome to deliver these mitochondria for degradation. To investigate a physiological role of macromitophagy in yeast, we examined how the atg32Δ-dependent mutational block of this process influences the chronological lifespan of cells grown in a nutrient-rich medium containing low (0.2%) concentration of glucose. Under these longevity-extending conditions of caloric restriction (CR) yeast cells are not starving. We also assessed a role of macromitophagy in lifespan extension by lithocholic acid (LCA), a bile acid that prolongs yeast longevity under CR conditions. Our findings imply that macromitophagy is a longevity assurance process underlying the synergistic beneficial effects of CR and LCA on yeast lifespan. Our analysis of how the atg32Δ mutation influences mitochondrial morphology, composition and function revealed that macromitophagy is required to maintain a network of healthy mitochondria. Our comparative analysis of the membrane lipidomes of organelles purified from wild-type and atg32Δ cells revealed that macromitophagy is required for maintaining cellular lipid homeostasis. We concluded that macromitophagy defines yeast longevity by modulating vital cellular processes inside and outside of mitochondria. PMID:23553280

  8. Microscopic age determination of human skeletons including an unknown but calculable variable

    DEFF Research Database (Denmark)

    Wallin, Johan Albert; Tkocz, Izabella; Kristensen, Gustav

    1994-01-01

    estimation, which includes the covariance matrix of four single equation residuals, improves the accuracy of age determination. The standard deviation, however, of age prediction remains 12.58 years. An experimental split of the data was made in order to demonstrate that the use of subgroups gives a false...... impression of higher precision of age determination. The present study demonstrates that determination of age at death through microscopic bone morphometry is considerably less precise than generally stated in the literature.......Histomorphometric semi-automatic image analysis of cross-sections of 101 femoral diaphyseal bone sections were performed to reconsider to what degree osteon remodelling in the outer cortex is affected by age. The data were analysed statistically using the generalized least squares method. The model...

  9. Aging and physiological changes of the kidneys including changes in glomerular filtration rate.

    Science.gov (United States)

    Musso, Carlos G; Oreopoulos, Dimitrios G

    2011-01-01

    In addition to the structural changes in the kidney associated with aging, physiological changes in renal function are also found in older adults, such as decreased glomerular filtration rate, vascular dysautonomia, altered tubular handling of creatinine, reduction in sodium reabsorption and potassium secretion, and diminished renal reserve. These alterations make aged individuals susceptible to the development of clinical conditions in response to usual stimuli that would otherwise be compensated for in younger individuals, including acute kidney injury, volume depletion and overload, disorders of serum sodium and potassium concentration, and toxic reactions to water-soluble drugs excreted by the kidneys. Additionally, the preservation with aging of a normal urinalysis, normal serum urea and creatinine values, erythropoietin synthesis, and normal phosphorus, calcium and magnesium tubular handling distinguishes decreased GFR due to normal aging from that due to chronic kidney disease. Copyright © 2011 S. Karger AG, Basel.

  10. Prospective validation of criteria, including age, for safe, nonsurgical management of the ruptured spleen

    International Nuclear Information System (INIS)

    Smith, J.S. Jr.; Wengrovitz, M.A.; DeLong, B.S.

    1992-01-01

    One hundred twelve cases of blunt splenic rupture were prospectively entered (October 1987-October 1991) into surgical or nonsurgical management groups using these criteria for the nonsurgical group: hemodynamic stability-age less than 55 years-CT scan appearance of grade I, II, or III injury-absence of concomitant injuries precluding abdominal assessment+absence of other documented abdominal injuries. All ages were included and AAST injury scaling was used. Patients were grouped from the trauma room. The surgical treatment group included 66 patients (49 splenectomies, 17 splenorraphies). These patients were generally older and more severely injured, required more transfused blood, and a longer ICU stay. The nonsurgical group included 46 patients with 33 older than 14 years. There were 3 patients over the age of 55 years inappropriately included in this group, and nonsurgical therapy failed in all three. Statistical analysis (chi 2) showed that more splenic injuries were observed and more spleens were saved with these criteria applied prospectively compared with a previous retrospective series in the same institution. The series had a success rate of 93%, and validates the criteria used for safe, nonsurgical management of the ruptured spleen and adds a new criterion: a maximum age of 55 years

  11. Prospective validation of criteria, including age, for safe, nonsurgical management of the ruptured spleen

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.S. Jr.; Wengrovitz, M.A.; DeLong, B.S. (Pennsylvania State University College of Medicine, Hershey (United States))

    1992-09-01

    One hundred twelve cases of blunt splenic rupture were prospectively entered (October 1987-October 1991) into surgical or nonsurgical management groups using these criteria for the nonsurgical group: hemodynamic stability-age less than 55 years-CT scan appearance of grade I, II, or III injury-absence of concomitant injuries precluding abdominal assessment+absence of other documented abdominal injuries. All ages were included and AAST injury scaling was used. Patients were grouped from the trauma room. The surgical treatment group included 66 patients (49 splenectomies, 17 splenorraphies). These patients were generally older and more severely injured, required more transfused blood, and a longer ICU stay. The nonsurgical group included 46 patients with 33 older than 14 years. There were 3 patients over the age of 55 years inappropriately included in this group, and nonsurgical therapy failed in all three. Statistical analysis (chi 2) showed that more splenic injuries were observed and more spleens were saved with these criteria applied prospectively compared with a previous retrospective series in the same institution. The series had a success rate of 93%, and validates the criteria used for safe, nonsurgical management of the ruptured spleen and adds a new criterion: a maximum age of 55 years.

  12. 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.

  13. Ascertaining year of birth/age at death in forensic cases: A review of conventional methods and methods allowing for absolute chronology

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Kjeldsen, H; Zweihoff, R

    2010-01-01

    Based on an actual case, where we were able to ascertain the year of birth of three dead babies found in a deep-freezer to within 1–2 years (1986, 1988 and 2004, respectively), we review the current state of forensic age determination/year of birth determination. The age of an individual (year...... of birth) is often a fundamental piece of data in connection with forensic identification of unidentified bodies. The methods most often used are based on determining various morphological, age-related, changes on the skeleton (or teeth, although odontological methods are not reviewed in this paper...

  14. Construction validity in equilibrium tests: chronological order in tasks presentation

    OpenAIRE

    Carolina Silveira; Marcos Trindade Pinheiro Menuchi; Carolina Sant’Ana Simões; Duarte Caetano; Lilian Bucken Gobbi

    2006-01-01

    The equilibrium tests of the Rosa Neto1 Motor evelopment Scale are constituted by ten tasks related to the chronological ages from 2 to 11 years and they determine the participants Motor Age. The tests presentation order is crescent from the child chronological age and the motor age is based on the success or failure in each task. The aim of this study was to analyze the construction validity of the equilibrium motor tests observing the ordering the levels of task difficulty. 76 children wit...

  15. Accessory mineral U-Th-Pb ages and 40Ar/39Ar eruption chronology, and their bearing on rhyolitic magma evolution in the Pleistocene Coso volcanic field, California

    Science.gov (United States)

    Simon, J.I.; Vazquez, J.A.; Renne, P.R.; Schmitt, A.K.; Bacon, C.R.; Reid, M.R.

    2009-01-01

    We determined Ar/Ar eruption ages of eight extrusions from the Pleistocene Coso volcanic field, a long-lived series of small volume rhyolitic domes in eastern California. Combined with ion-microprobe dating of crystal ages of zircon and allanite from these lavas and from granophyre geothermal well cuttings, we were able to track the range of magma-production rates over the past 650 ka at Coso. In ??? 230 ka rhyolites we find no evidence of protracted magma residence or recycled zircon (or allanite) from Pleistocene predecessors. A significant subset of zircon in the ???85 ka rhyolites yielded ages between ???100 and 200 Ma, requiring that generation of at least some rhyolites involves material from Mesozoic basement. Similar zircon xenocrysts are found in an ???200 ka granophyre. The new age constraints imply that magma evolution at Coso can occur rapidly as demonstrated by significant changes in rhyolite composition over short time intervals (???10's to 100's ka). In conjunction with radioisotopic age constraints from other young silicic volcanic fields, dating of Coso rhyolites highlights the fact that at least some (and often the more voluminous) rhyolites are produced relatively rapidly, but that many small-volume rhyolites likely represent separation from long-lived mushy magma bodies. ?? The Author(s) 2009.

  16. Accessory mineral U-Th-Pb ages and 40Ar/39Ar eruption chronology, and their bearing on rhyolitic magma evolution in the Pleistocene Coso volcanic field, California

    Science.gov (United States)

    Simon, Justin I.; Vazquez, Jorge A.; Renne, Paul R.; Schmitt, Axel K.; Bacon, Charles R.; Reid, Mary R.

    2009-10-01

    We determined Ar/Ar eruption ages of eight extrusions from the Pleistocene Coso volcanic field, a long-lived series of small volume rhyolitic domes in eastern California. Combined with ion-microprobe dating of crystal ages of zircon and allanite from these lavas and from granophyre geothermal well cuttings, we were able to track the range of magma-production rates over the past 650 ka at Coso. In ≤230 ka rhyolites we find no evidence of protracted magma residence or recycled zircon (or allanite) from Pleistocene predecessors. A significant subset of zircon in the ~85 ka rhyolites yielded ages between ~100 and 200 Ma, requiring that generation of at least some rhyolites involves material from Mesozoic basement. Similar zircon xenocrysts are found in an ~200 ka granophyre. The new age constraints imply that magma evolution at Coso can occur rapidly as demonstrated by significant changes in rhyolite composition over short time intervals (≤10’s to 100’s ka). In conjunction with radioisotopic age constraints from other young silicic volcanic fields, dating of Coso rhyolites highlights the fact that at least some (and often the more voluminous) rhyolites are produced relatively rapidly, but that many small-volume rhyolites likely represent separation from long-lived mushy magma bodies.

  17. A contribution to late Middle Paleolithic chronology of the Levant: New luminescence ages for the Atlit Railway Bridge site, Coastal Plain, Israel

    DEFF Research Database (Denmark)

    Porat, N.; Jain, Mayank; Ronen, A.

    2018-01-01

    of the different minerals and signals mostly agree within errors. The new luminescence ages date the sediment infill in Caves III and II to ~90 ka and ~70 ka, respectively, indicating that hominin occupation of this locality is coeval with the nearby Skhul Cave and Layer B in Tabun Cave....... Coastal Plain of Israel. Quaternary International 121, 1e52), providing a maximum age for the artifacts. Samples for luminescence dating were collected from the infill of the two caves (II and III), from the same deposits as the archaeological finds. Both quartz and alkali feldspars (KF) were extracted...... and measured using four different luminescence signals: optically stimulated luminescence (blue OSL) and violet stimulated luminescence (VSL) on quartz; and the infrared stimulated luminescence (IRSL) post-IR-IR290 signal and the IR50 signal corrected for anomalous fading on KF. The ages obtained from analyses...

  18. Eruption chronology of the first deciduous teeth in children born prematurely with birth weight less than 1500g

    Directory of Open Access Journals (Sweden)

    Pedro Garcia F. Neto

    2014-03-01

    Full Text Available Objective: To describe the eruption chronology of the first deciduous teeth in premature infants with birth weight less than 1500g and to compare it according to gender and nutritional status at birth. Methods: Longitudinal study including 40 low birth weight premature infants of both genders. The tooth was considered erupted when the crown went through the gum and became part of the oral environment. The comparison of the eruption chronology in relation to gender and among children appropriate or small for gestational age was done by Student's t-test, being significant p<0.05. Results: The eruption of the first tooth (teeth occurred, on average, with 11.0±2.1 months of chronological age and with 9.6±1.9 months corrected for prematurity. The first erupted teeth were the lower central incisors. The average eruption for males was 9.7±1.9 and, for females, 9.5±1.9 months, both corrected for prematurity (p=0.98. The average eruption in children with birth weight appropriate for gestational age was 10.1±1.4 months; for small for gestational age, it was 9.4±2.2, also corrected for prematurity (p=0.07. Conclusions: The average eruption age of the first teeth, corrected for prematurity, was 9.6 months. Sex and nutritional status at birth did not change the eruption chronology.

  19. Implications of new ^{40}Ar/^{39}Ar age of Mallapur Intrusives on the chronology and evolution of the Kaladgi Basin, Dharwar Craton, India

    Science.gov (United States)

    Pillai, Shilpa Patil; Pande, Kanchan; Kale, Vivek S.

    2018-04-01

    The Kaladgi Basin on the northern edge of the Dharwar craton has characters diverse from the other epicratonic Purana basins of Peninsular India. Sedimentological studies in the basin have established the presence of three cycles of flooding separated by an event of intra-basinal deformation accompanied by low grade incipient metamorphism. The overall structural configuration of the basin indicates its development by supracrustal extension accompanied by shearing in a trans-tensional regime during the Mesoproterozoic. This was followed by sagging that yielded Neoproterozoic sedimentation in a successor nested basin. ^{40}Ar/^{39}Ar dating of an intrusive mafic dyke along the axial plane of a fold has yielded a plateau age of 1154{± }4 Ma. This helps constraint the age of the various events during the evolution of this basin.

  20. Temperature-sensitive Tien Shan tree ring chronologies show multi-centennial growth trends

    Energy Technology Data Exchange (ETDEWEB)

    Esper, J. [Swiss Federal Research Institute WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Shiyatov, S.G.; Mazepa, V.S. [Institute of Plant and Animal Ecology, Ural Division of Russian Academy of Sciences, 8 Marta Street 202, 620144 Ekaterinburg (Russian Federation); Wilson, R.J.S. [School of GeoSciences, Grant Institute, Edinburgh University, West Mains Road, Edinburgh EH9 3JW (United Kingdom); Graybill, D.A.; Funkhouser, G. [Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona 85721 (United States)

    2003-12-01

    Two millennia-length juniper ring width chronologies, processed to preserve multi-centennial growth trends, are presented for the Alai Range of the western Tien Shan in Kirghizia. The chronologies average the information from seven near-timberline sampling sites, and likely reflect summer temperature variation. For comparison, chronologies are also built using standard dendrochronological techniques. We briefly discuss some qualities of these ''inter-decadal'' records, and show the low frequency components removed by the standardization process include a long-term negative trend in the first half of the last millennium and a long-term positive trend since about AD 1800. The multi-centennial scale Alai Range chronologies, where these trends are retained, are both systematically biased (but in an opposite sense) in their low frequency domains. Nevertheless, they represent the best constraints and estimates of long-term summer temperature variation, and reflect the Medieval Warm Period, the Little Ice Age, and a period of warming since about the middle of the nineteenth century. (orig.)

  1. A New Chronology of Late Quaternary Sequences From the Central Arctic Ocean Based on "Extinction Ages" of Their Excesses in 231Pa and 230Th

    Science.gov (United States)

    Hillaire-Marcel, C.; Ghaleb, B.; de Vernal, A.; Maccali, J.; Cuny, K.; Jacobel, A.; Le Duc, C.; McManus, J.

    2017-12-01

    Merging the late Quaternary Arctic paleoceanography into the Earth's global climate history remains challenging due to the lack of robust marine chronostratigraphies. Over ridges notably, low and variable sedimentation rates, scarce biogenic remains ensuing from low productivity and/or poor preservation, and oxygen isotope and paleomagnetic records differing from global stacks represent major impediments. However, as illustrate here based on consistent records from Mendeleev-Alpha and Lomonosov Ridges, disequilibria between U-series isotopes can provide benchmark ages. In such settings, fluxes of the particle-reactive U-daughter isotopes 230Th and 231Pa from the water column, are not unequivocally linked to sedimentation rates, but rather to sea-ice rafting and brine production histories, thus to the development of sea-ice factories over shelves during intervals of high relative sea level. The excesses in 230Th and 231Pa over fractions supported by their parent U-isotopes, collapse down sedimentary sequences, due to radioactive decay, and provide radiometric benchmark ages of approximately 300 and 140 ka, respectively. These "extinction ages" point to mean sedimentation rates of ˜4.3 and ˜1.7 mm/ka, respectively, over the Lomonosov and Mendeleev Ridges, which are significantly lower than assumed in most recent studies, thus highlighting the need for revisiting current interpretations of Arctic lithostratigraphies in relation to the global-scale late Quaternary climatostratigraphy.

  2. Age correction in monitoring audiometry: method to update OSHA age-correction tables to include older workers

    OpenAIRE

    Dobie, Robert A; Wojcik, Nancy C

    2015-01-01

    Objectives The US Occupational Safety and Health Administration (OSHA) Noise Standard provides the option for employers to apply age corrections to employee audiograms to consider the contribution of ageing when determining whether a standard threshold shift has occurred. Current OSHA age-correction tables are based on 40-year-old data, with small samples and an upper age limit of 60?years. By comparison, recent data (1999?2006) show that hearing thresholds in the US population have improved....

  3. Bayesian chronological analyses consistent with synchronous age of 12,835-12,735 Cal B.P. for Younger Dryas boundary on four continents

    DEFF Research Database (Denmark)

    Kennett, James P.; Kennett, Douglas J.; Culleton, Brendan J.

    2015-01-01

    The Younger Dryas impact hypothesis posits that a cosmic impact across much of the Northern Hemisphere deposited the Younger Dryas boundary (YDB) layer, containing peak abundances in a variable assemblage of proxies, including magnetic and glassy impact-related spherules, high-temperature mineral...

  4. Gender differences in episodic memory and visual working memory including the effects of age.

    Science.gov (United States)

    Pauls, Franz; Petermann, Franz; Lepach, Anja Christina

    2013-01-01

    Analysing the relationship between gender and memory, and examining the effects of age on the overall memory-related functioning, are the ongoing goals of psychological research. The present study examined gender and age group differences in episodic memory with respect to the type of task. In addition, these subgroup differences were also analysed in visual working memory. A sample of 366 women and 330 men, aged between 16 and 69 years of age, participated in the current study. Results indicate that women outperformed men on auditory memory tasks, whereas male adolescents and older male adults showed higher level performances on visual episodic and visual working memory measures. However, the size of gender-linked effects varied somewhat across age groups. Furthermore, results partly support a declining performance on episodic memory and visual working memory measures with increasing age. Although age-related losses in episodic memory could not be explained by a decreasing verbal and visuospatial ability with age, women's advantage in auditory episodic memory could be explained by their advantage in verbal ability. Men's higher level visual episodic memory performance was found to result from their advantage in visuospatial ability. Finally, possible methodological, biological, and cognitive explanations for the current findings are discussed.

  5. Impact of the Little Ice Age cooling and 20th century climate change on peatland vegetation dynamics in central and northern Alberta using a multi-proxy approach and high-resolution peat chronologies

    Science.gov (United States)

    Magnan, Gabriel; van Bellen, Simon; Davies, Lauren; Froese, Duane; Garneau, Michelle; Mullan-Boudreau, Gillian; Zaccone, Claudio; Shotyk, William

    2018-04-01

    Northern boreal peatlands are major terrestrial sinks of organic carbon and these ecosystems, which are highly sensitive to human activities and climate change, act as sensitive archives of past environmental change at various timescales. This study aims at understanding how the climate changes of the last 1000 years have affected peatland vegetation dynamics in the boreal region of Alberta in western Canada. Peat cores were collected from five bogs in the Fort McMurray region (56-57° N), at the southern limit of sporadic permafrost, and two in central Alberta (53° N and 55° N) outside the present-day limit of permafrost peatlands. The past changes in vegetation communities were reconstructed using detailed plant macrofossil analyses combined with high-resolution peat chronologies (14C, atmospheric bomb-pulse 14C, 210Pb and cryptotephras). Peat humification proxies (C/N, H/C, bulk density) and records of pH and ash content were also used to improve the interpretation of climate-related vegetation changes. Our study shows important changes in peatland vegetation and physical and chemical peat properties during the Little Ice Age (LIA) cooling period mainly from around 1700 CE and the subsequent climate warming of the 20th century. In some bogs, the plant macrofossils have recorded periods of permafrost aggradation during the LIA with drier surface conditions, increased peat humification and high abundance of ericaceous shrubs and black spruce (Picea mariana). The subsequent permafrost thaw was characterized by a short-term shift towards wetter conditions (Sphagnum sect. Cuspidata) and a decline in Picea mariana. Finally, a shift to a dominance of Sphagnum sect. Acutifolia (mainly Sphagnum fuscum) occurred in all the bogs during the second half of the 20th century, indicating the establishment of dry ombrotrophic conditions under the recent warmer and drier climate conditions.

  6. Reassessing the NTCTCS Staging Systems for Differentiated Thyroid Cancer, Including Age at Diagnosis

    Science.gov (United States)

    McLeod, Donald S.A.; Jonklaas, Jacqueline; Brierley, James D.; Ain, Kenneth B.; Cooper, David S.; Fein, Henry G.; Haugen, Bryan R.; Ladenson, Paul W.; Magner, James; Ross, Douglas S.; Skarulis, Monica C.; Steward, David L.; Xing, Mingzhao; Litofsky, Danielle R.; Maxon, Harry R.

    2015-01-01

    Background: Thyroid cancer is unique for having age as a staging variable. Recently, the commonly used age cut-point of 45 years has been questioned. Objective: This study assessed alternate staging systems on the outcome of overall survival, and compared these with current National Thyroid Cancer Treatment Cooperative Study (NTCTCS) staging systems for papillary and follicular thyroid cancer. Methods: A total of 4721 patients with differentiated thyroid cancer were assessed. Five potential alternate staging systems were generated at age cut-points in five-year increments from 35 to 70 years, and tested for model discrimination (Harrell's C-statistic) and calibration (R2). The best five models for papillary and follicular cancer were further tested with bootstrap resampling and significance testing for discrimination. Results: The best five alternate papillary cancer systems had age cut-points of 45–50 years, with the highest scoring model using 50 years. No significant difference in C-statistic was found between the best alternate and current NTCTCS systems (p = 0.200). The best five alternate follicular cancer systems had age cut-points of 50–55 years, with the highest scoring model using 50 years. All five best alternate staging systems performed better compared with the current system (p = 0.003–0.035). There was no significant difference in discrimination between the best alternate system (cut-point age 50 years) and the best system of cut-point age 45 years (p = 0.197). Conclusions: No alternate papillary cancer systems assessed were significantly better than the current system. New alternate staging systems for follicular cancer appear to be better than the current NTCTCS system, although they require external validation. PMID:26203804

  7. Densidade mineral óssea, função pulmonar, idade cronológica e idade de diagnóstico em crianças e adolescentes com fibrose cística Bone mineral density, pulmonary function, chronological age, and age at diagnosis in children and adolescents with cystic fibrosis

    Directory of Open Access Journals (Sweden)

    Márcio V.F. Donadio

    2013-04-01

    . First, demographic data were collected and, subsequently, patients underwent a spirometric test. All patients answered the Cystic Fibrosis Quality of Life Questionnaire (CFQ and underwent the six-minute walk test (6MWT and bone densitometry (DXA. RESULTS: A total of 25 CF patients were included, of which 56% were males. The mean age was 12.3±3.4 years; mean height was 149.2±14.4 cm; and mean weight was 44.4±13.9 kg. Most results on pulmonary function and bone mineral density (BMD were within normal limits. The mean forced expiratory volume in one second (FEV1 was 92.5±23.6 (% of predicted, mean forced vital capacity (FVC was 104.4±21.3 (% of predicted, and mean BMD z-score was 0.1±1.0. BMD was moderately correlated with FEV1 (r = 0.43, p = 0.03 and FVC (r = 0.57, p = 0.003. Regarding chronological age and age at diagnosis, a moderate and inverse correlation was also found (r = -0.55, p = 0.004 ; r = -0.57, p = 0.003, respectively. However, no significant correlations were found with the data from CFQ, 6MWT, and body mass index. CONCLUSION: Most patients had BMD within normal limits and presented a positive correlation with pulmonary function, as well as a negative correlation with chronological age and age at diagnosis.

  8. Tell me your life: including life stories in an adult development and aging course.

    Science.gov (United States)

    Villar, Feliciano; Celdran, Montserrat; Fabà, Josep

    2014-01-01

    The goals of this study were to determine the learning impact of an assignment that consisted of interviewing and analyzing older people's life stories, and to explore how the assignment was evaluated by students. Participants in the study were 122 first-year social education students enrolled in an adult development and aging course. They evaluated the assignment using an eight-adjective questionnaire and were asked about the benefits of the task. Their answers to the questionnaire were then reviewed using content analysis. The results indicated that marks on the life story assignment predicted marks on an exam about basic course concepts. Students considered that the assignment was interesting, useful, and integrated into the course, although most of them also thought that it was very time-consuming. They identified benefits related to the explicit goals of the course (improvement in the learning of developmental concepts, the acquisition of research-related skills, and the deactivation of aging stereotypes) and personal, growth-related benefits. The authors discuss the difficulties posed by the assignment and its usefulness as a complement to more traditional, lecture-based teaching methods in adult development and aging courses.

  9. Enduring effects of severe developmental adversity, including nutritional deprivation, on cortisol metabolism in aging Holocaust survivors.

    Science.gov (United States)

    Yehuda, Rachel; Bierer, Linda M; Andrew, Ruth; Schmeidler, James; Seckl, Jonathan R

    2009-06-01

    In animal models, early life exposure to major environmental challenges such as malnutrition and stress results in persisting cardiometabolic, neuroendocrine and affective effects. While such effects have been associated with pathogenesis, the widespread occurrence of 'developmental programming' suggests it has adaptive function. Glucocorticoids may mediate 'programming' and their metabolism is known to be affected by early life events in rodents. To examine these relationships in humans, cortisol metabolism and cardiometabolic disease manifestations were examined in Holocaust survivors in relation to age at exposure and affective dysfunction, notably lifetime posttraumatic stress disorder (PTSD). Fifty-one Holocaust survivors and 22 controls without Axis I disorder collected 24-h urine samples and were evaluated for psychiatric disorders and cardiometabolic diagnoses. Corticosteroids and their metabolites were assayed by gas chromatography-mass spectroscopy (GC-MS); cortisol was also measured by radioimmunoassay (RIA). Holocaust survivors showed reduced cortisol by RIA, and decreased levels of 5alpha-tetrahydrocortisol (5alpha-THF) and total glucocorticoid production by GC-MS. The latter was associated with lower cortisol metabolism by 5alpha-reductase and 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type-2. The greatest decrements were associated with earliest age of Holocaust exposure and less severe PTSD symptomatology. Cardiometabolic manifestations were associated with decreased 11beta-HSD-2 activity. In controls, 5alpha-reductase was positively associated with trauma-related symptoms (i.e., to traumatic exposures unrelated to the Holocaust). Extreme malnutrition and related stress during development is associated with long-lived alterations in specific pathways of glucocorticoid metabolism. These effects may be adaptive and link with lower risks of cardiometabolic and stress-related disorders in later life.

  10. Prenatal Exposure to Organohalogens, Including Brominated Flame Retardants, Influences Motor, Cognitive, and Behavioral Performance at School Age

    NARCIS (Netherlands)

    Roze, Elise; Meijer, Lisethe; Bakker, Attie; Van Braeckel, Koenraad N. J. A.; Sauer, Pieter J. J.; Bos, Arend F.

    2009-01-01

    BACKGROUND: Organohalogen compounds (OHCs) are known to have neurotoxic effects on the developing brain. OBJECTIVE: We investigated the influence of prenatal exposure to OHCs, including brominated flame retardants, on motor, cognitive, and behavioral outcome in healthy children of school age.

  11. Quantity of dates trumps quality of dates for dense Bayesian radiocarbon sediment chronologies - Gas ion source 14C dating instructed by simultaneous Bayesian accumulation rate modeling

    Science.gov (United States)

    Rosenheim, B. E.; Firesinger, D.; Roberts, M. L.; Burton, J. R.; Khan, N.; Moyer, R. P.

    2016-12-01

    Radiocarbon (14C) sediment core chronologies benefit from a high density of dates, even when precision of individual dates is sacrificed. This is demonstrated by a combined approach of rapid 14C analysis of CO2 gas generated from carbonates and organic material coupled with Bayesian statistical modeling. Analysis of 14C is facilitated by the gas ion source on the Continuous Flow Accelerator Mass Spectrometry (CFAMS) system at the Woods Hole Oceanographic Institution's National Ocean Sciences Accelerator Mass Spectrometry facility. This instrument is capable of producing a 14C determination of +/- 100 14C y precision every 4-5 minutes, with limited sample handling (dissolution of carbonates and/or combustion of organic carbon in evacuated containers). Rapid analysis allows over-preparation of samples to include replicates at each depth and/or comparison of different sample types at particular depths in a sediment or peat core. Analysis priority is given to depths that have the least chronologic precision as determined by Bayesian modeling of the chronology of calibrated ages. Use of such a statistical approach to determine the order in which samples are run ensures that the chronology constantly improves so long as material is available for the analysis of chronologic weak points. Ultimately, accuracy of the chronology is determined by the material that is actually being dated, and our combined approach allows testing of different constituents of the organic carbon pool and the carbonate minerals within a core. We will present preliminary results from a deep-sea sediment core abundant in deep-sea foraminifera as well as coastal wetland peat cores to demonstrate statistical improvements in sediment- and peat-core chronologies obtained by increasing the quantity and decreasing the quality of individual dates.

  12. Cultural and Chronological Horizons and the Problem of the Early Sarmatian Culture Formation

    Directory of Open Access Journals (Sweden)

    Yablonsky Leonid Teodorovich

    2015-12-01

    Full Text Available On the materials of Eurasian early nomads’ archaeology we highlight the South Ural cultural and historical area (UCHA. Geographically it includes steppe regions of West Kazakhstan, Chelyabinsk and Orenburg regions, steppe and forest steppe zones of the Republic of Bashkortostan. There were similar cultural processes that led to the Early Sarmatian archaeological culture formation in the Early Iron Age. Under the cultural and chronological horizon we understand the geographic region that is significantly larger than UCHA. Practically it has no geographic boundaries. Specificity of the horizon is that at a certain chronological stage (phase artifacts and their complexes, signs of spiritual culture are widely distributed that will mark the horizon – the horizon markers such as well known Scythian triad. Global chronological scheme of the Southern Trans-Urals cultural and historical area can be represented as follows: “Sauromatian” cultural and chronological horizon – the second half of the 6th – the end of the 4th (3rd centuries B.C. – Phase “A” – the second half of the 6th – the middle of the 5th centuries B.C. – Phase “B” – the second half of the 5th – the third quarter of the 4th centuries B.C. – Phase “C” – the third quarter of the 4th – the 3rd century B.C. Typologically the burial grounds like Filippovka I and Perevolochan can be attributed to the Early-Sarmatian archaeological culture, i.e. to the time of the ethnic consciousness formation of suspected archaeological Early Sarmatians. In this period ordinary mounds and graves appear along with the elite ones. It is advisable to consider the sites of the “Sauromatian” and Early-Sarmatian cultures of the South Urals of the end of the 5th-3rd centuries B.C. as a single culture of the early nomads.

  13. Chronology of p53 protein accumulation in gastric carcinogenesis

    NARCIS (Netherlands)

    Craanen, M. E.; Blok, P.; Dekker, W.; Offerhaus, G. J.; Tytgat, G. N.

    1995-01-01

    p53 Protein accumulation in early gastric carcinoma was studied in relation to the histological type (Lauren classification) and the type of growth pattern, including the chronology of p53 protein accumulation during carcinogenesis. Forty five, paraffin embedded gastrectomy specimens from early

  14. Chronology protection in string theory

    International Nuclear Information System (INIS)

    Dyson, Lisa

    2004-01-01

    Many solutions of General Relativity appear to allow the possibility of time travel. This was initially a fascinating discovery, but geometries of this type violate causality, a basic physical law which is believed to be fundamental. Although string theory is a proposed fundamental theory of quantum gravity, geometries with closed timelike curves have resurfaced as solutions to its low energy equations of motion. In this paper, we will study the class of solutions to low energy effective supergravity theories related to the BMPV black hole and the rotating wave-D1-D5-brane system. Time travel appears to be possible in these geometries. We will attempt to build the causality violating regions and propose that stringy effects prohibit their construction. The proposed chronology protection agent for these geometries mirrors a mechanism string theory employs to resolve a class of naked singularities. (author)

  15. Handbook for Instruction on Aging in California Public Schools. Kindergarten Through Grade Twelve.

    Science.gov (United States)

    California State Dept. of Education, Sacramento.

    This handbook is designed to assist teachers at the elementary and secondary level in the development of curricula on aging which can integrate the concepts of aging into ongoing lesson plans. The five content areas of instruction include chronological aging, physiological and biological aging, sociocultural aspects of aging, psychological aging,…

  16. A sub-fossil kauri (Agathis australis) tree-ring chronology

    International Nuclear Information System (INIS)

    Bridge, M.C.; Ogden, J.

    1986-01-01

    A 491-year floating tree-ring chronology was constructed using sub-fossil bog kauris, Agathis australis, from a site near Huntly, North Island, New Zealand. The chronology has been approximately dated to within the period 3,500 B.P. to 3,000 B.P. by radiocarbon dating. This is the first sub-fossil New Zealand chronology, and shows the potential for the formation of a long chronology from the present back over several millenia. The applications of this chronology and its possible extensions include radiocarbon calibration for the Southern Hemisphere, and climatic reconstructions based on ring-widths. It will also assist interpretation of the history of the Waikato Valley over the last few millenia

  17. An investigation of the common signal in tree ring stable isotope chronologies at temperate sites

    Science.gov (United States)

    Saurer, M.; Cherubini, P.; Reynolds-Henne, C. E.; Treydte, K. S.; Anderson, W. T.; Siegwolf, R. T. W.

    2008-12-01

    It is currently not well known how coherent carbon and oxygen isotope chronologies from different species and sites are under temperate climate conditions. Here we investigated nine chronologies from Switzerland covering the last two centuries, including three deciduous species (Fagus sylvatica, Fraxinus excelsior, and Quercus petraea) and three conifer species (Abies alba, Picea abies, and Pinus sylvestris) from sites neither strongly limited by temperature nor precipitation. All of the chronologies except Fraxinus were significantly correlated to at least one other chronology. Correlations between different species of the same site were of similar strength to correlations between the sites. We observed a strong common high-frequency (interannual) signal for the δ13C chronologies, whereas the low-frequency (decadal-scale) signal was more similar among the δ18O chronologies. For both carbon and oxygen isotopes, we found significant positive relationships with annual and growing season temperatures and negative relationships with precipitation, again of similar magnitude for all species except for Fraxinus, which contained only minor climatic information. Averaging of all chronologies resulted in an increase in the climatic signal of the mean chronology. The combined δ18O record reflected decadal-scale temperature variations remarkably well (r = 0.72). However, the relationship between climate and carbon isotopes declined over the last 3 decades of the 20th century, probably related to the steep increase in atmospheric CO2 concentrations, resulting in strongly diverging δ13C trends of the different chronologies. Our study indicates that combining chronologies from different species enhances the potential of isotope studies for extending climate reconstructions into areas of temperate climate.

  18. Prenatal Exposure to Organohalogens, Including Brominated Flame Retardants, Influences Motor, Cognitive, and Behavioral Performance at School Age

    OpenAIRE

    Roze, Elise; Meijer, Lisethe; Bakker, Attie; Van Braeckel, Koenraad N.J.A.; Sauer, Pieter J.J.; Bos, Arend F.

    2009-01-01

    Background Organohalogen compounds (OHCs) are known to have neurotoxic effects on the developing brain. Objective We investigated the influence of prenatal exposure to OHCs, including brominated flame retardants, on motor, cognitive, and behavioral outcome in healthy children of school age. Methods This study was part of the prospective Groningen infant COMPARE (Comparison of Exposure-Effect Pathways to Improve the Assessment of Human Health Risks of Complex Environmental Mixtures of Organoha...

  19. 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

  20. Quality assessment of chronologies in Latin American pollen records: a contribution to centennial to millennial scale studies of environmental change

    OpenAIRE

    Flantua, S.G.A.; Hooghiemstra, H.; Blaauw, M.

    2015-01-01

    The newly updated inventory of the Latin American Pollen Database (LAPD) offers an important overview of data available for multi-proxy and multi-site purposes. However, heterogeneous paleoecological databases are not suitable to be integrated without an uncertainty assessment of existing chronologies. Therefore, we collected all chronological control points and age model metadata from the LAPD literature to create a complementary chronolo...

  1. Comparison of chronology of teeth eruption with body mass index among school children at Mangalore: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Nagaratna B Bagewadi

    2016-01-01

    Full Text Available Introduction: The development and eruption of the teeth, chronologies of human dentitions, dental age, and tooth formation standards are important aspects applied to dental practice. Body mass index (BMI gives an indication about the nutritional status of the child. It is relevant to know whether BMI has influenced chronology of tooth eruption pattern. Aim: To determine the eruption age of the different permanent teeth and compare eruption age with BMI in a group of children from selected schools in Mangalore. Materials and Methods: A cross-sectional study was designed in which 2928 children ranging in age from 5.5 to 15 years were included in the study. The children were divided into 20 chronological age groups with half year intervals. All the children were examined by a single examiner with the help of a trained assistant. The teeth were examined under natural light with mouth mirror. The comparison was made between mean eruption ages in males and females using the independent t-test. Results: There were 1526 males constituting 52.1% and 1402 females constituting 47.9% of the total sample of 2928 children. The mean age of eruption of maxillary central incisor, maxillary lateral incisor, maxillary and mandibular canines, maxillary and mandibular premolars, maxillary and mandibular second molars were found to have statistical significant with BMI. The mean age of eruption of the teeth in females was found to be earlier than in males, with the exception of the maxillary first molar which is earlier in males. Conclusion: Different categories of BMI were underweight, normal weight, risk of overweight and overweight, wherein overweight children had early eruption of teeth. Girls had early eruption time compared to boys.

  2. 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 in...

  3. An A. S. Neill/Summerhill Chronology.

    Science.gov (United States)

    Matthias, William

    1980-01-01

    This chronology of the life of Alexander Sutherland Neill, headmaster of Summerhill School, details each year of his life from 1883 to 1973. The author of 21 books, Neill did not espouse a return to "basics" in education. (JN)

  4. Atmospheric Heavy Metal Pollution - Development of Chronological ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 4. Atmospheric Heavy Metal Pollution - Development of Chronological Records and Geochemical Monitoring. Rohit Shrivastav. General Article Volume 6 Issue 4 April 2001 pp 62-68 ...

  5. Polypharmacy including falls risk-increasing medications and subsequent falls in community-dwelling middle-aged and older adults.

    Science.gov (United States)

    Richardson, Kathryn; Bennett, Kathleen; Kenny, Rose Anne

    2015-01-01

    polypharmacy is an important risk factor for falls, but recent studies suggest only when including medications associated with increasing the risk of falls. a prospective, population-based cohort study. 6,666 adults aged ≥50 years from The Irish Longitudinal study on Ageing. participants reported regular medication use at baseline. Any subsequent falls, any injurious falls and the number of falls were reported 2 years later. The association between polypharmacy (>4 medications) or fall risk-increasing medications and subsequent falls or injurious falls was assessed using modified Poisson regression. The association with the number of falls was assessed using negative binomial regression. during follow-up, 231 falls per 1,000 person-years were reported. Polypharmacy including antidepressants was associated with a greater risk of any fall (adjusted relative risk (aRR) 1.28, 95% CI 1.06-1.54), of injurious falls (aRR 1.51, 95% CI 1.10-2.07) and a greater number of falls (adjusted incident rate ratio (aIRR) 1.60, 95% CI 1.19-2.15), but antidepressant use without polypharmacy and polypharmacy without antidepressants were not. The use of benzodiazepines was associated with injurious falls when coupled with polypharmacy (aRR 1.40, 95% CI 1.04-1.87), but was associated with a greater number of falls (aIRR 1.32, 95% CI 1.05-1.65), independent of polypharmacy. Other medications assessed, including antihypertensives, diuretics and antipsychotics, were not associated with outcomes. in middle-aged and older adults, polypharmacy, including antidepressant or benzodiazepine use, was associated with injurious falls and a greater number of falls. © The Author 2014. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Minimally invasive percutaneous nephrolithotomy in preschool age children with kidney calculi (including stones induced by melamine-contaminated milk powder).

    Science.gov (United States)

    Yan, Xiang; Al-Hayek, Samih; Gan, Weidong; Zhu, Wei; Li, Xiaogong; Guo, Hongqian

    2012-10-01

    This study was undertaken to assess the safety and efficacy of minimally invasive percutaneous nephrolithotomy (mini-PCNL) using ureteroscope and pneumatic intracorporeal lithotripsy in preschool age children with kidney calculi. We studied 27 renal units in 20 patients of preschool age (≤ 6 years) who underwent mini-PCNL at our institute. The mean age was 42.6 months (range 14-68 months). The average stone burden was 1.85 cm (range 0.9-2.8 cm). Eight patients aged 14 to 58 months had been exposed to melamine-tainted powdered formula. The mini-PCNL was performed with an X-ray-guided peripheral puncture. Minimal tract dilatation was undertaken to fit a 14-16 Fr peel-away sheath. Ureteroscope and pneumatic intracorporeal lithotripsy were used to fragment the stones. Complete clearance was achieved in 23 renal units (85.2 %) with mini-PCNL monotherapy. This has increased to 92.6 % after adjunctive ESWL. The average fall in hemoglobin was 1.28 g/dL. None of the patients required blood transfusion. The median length of hospital stay was 8.2 days. Patients were followed up every 6 months for 2 years. There has been only one recurrence of stone and no long-term complications. Mini-PCNL is a effective treatment for pediatric kidney stones refractory to extracorporeal shock wave lithotripsy, including stones induced by melamine-contaminated milk powder. The "mini-PCNL" technique, which uses ureteroscope and pneumatic intracorporeal lithotripsy, is a safe and feasible modality for treating renal calculi in preschool age children.

  7. The Early and Middle Neolithic in NW Russia: radiocarbon chronologies from the Sukhona and Onega regions

    Directory of Open Access Journals (Sweden)

    Henny Piezonka

    2018-01-01

    Full Text Available The onset of the Neolithic period in the Russian North is defined by the emergence of pottery vessels in the archaeological record. The ceramics produced by mobile hunter-gatherer-fisher groups in the north-eastern European forest zone are among the earliest in Europe, starting around 6000 cal BC. After the initial mosaic of local styles in the Early Neolithic, including sparsely decorated wares and early Comb Ware, the Middle Neolithic period, starting in the 5th millennium cal BC, saw the development and spread of larger, more homogenous typological entities between the Urals and the Baltic, the Comb-Pit and Pit-Comb wares. Absolute chronologies, however, are still subject to debate, due to a general lack of reliable contextual information. Direct 14C dating of carbonised surface residues (‘food crusts’ on pots can help to address this problem, as it dates the use of the pottery; but if aquatic foods were processed in the vessels, the respective radiocarbon ages can appear to be too old due to the freshwater reservoir effect. In this pa­per, we discuss the radiocarbon chronologies of four important stratified archaeological complexes in the region between Lake Onega and the Sukhona basin, Berezovaya Slobodka, Veksa, Karavaikha, and Tudo­zero. A growing series of dates, including AMS dates, sheds new light on the onset and further periodisation of the Early and Middle Neolithic in this important area between Eastern Fennoscandia, Central Rus­sia and the Far North-East of Europe, although problems concerning the absolute chronology of the initial Neolithic remain.

  8. Predictive values derived from lower wisdom teeth developmental stages on orthopantomograms to calculate the chronological age in adolescence and young adults as a prerequisite to obtain age-adjusted informed patient consent prior to elective surgical procedures in young patients with incomplete or mismatched personal data.

    Science.gov (United States)

    Friedrich, Reinhard E; Schmidt, Kirsten; Treszl, András; Kersten, Jan F

    2016-01-01

    Introduction: Surgical procedures require informed patient consent, which is mandatory prior to any procedure. These requirements apply in particular to elective surgical procedures. The communication with the patient about the procedure has to be comprehensive and based on mutual understanding. Furthermore, the informed consent has to take into account whether a patient is of legal age. As a result of large-scale migration, there are eventually patients planned for medical procedures, whose chronological age can't be assessed reliably by physical inspection alone. Age determination based on assessing wisdom tooth development stages can be used to help determining whether individuals involved in medical procedures are of legal age, i.e., responsible and accountable. At present, the assessment of wisdom tooth developmental stages barely allows a crude estimate of an individual's age. This study explores possibilities for more precise predictions of the age of individuals with emphasis on the legal age threshold of 18 years. Material and Methods: 1,900 dental orthopantomograms (female 938, male 962, age: 15-24 years), taken between the years 2000 and 2013 for diagnosis and treatment of diseases of the jaws, were evaluated. 1,895 orthopantomograms (female 935, male 960) of 1,804 patients (female 872, male 932) met the inclusion criteria. The archives of the Department of Diagnostic Radiology in Dentistry, University Medical Center Hamburg-Eppendorf, and of an oral and maxillofacial office in Rostock, Germany, were used to collect a sufficient number of radiographs. An effort was made to achieve almost equal distribution of age categories in this study group; 'age' was given on a particular day. The radiological criteria of lower third molar investigation were: presence and extension of periodontal space, alveolar bone loss, emergence of tooth, and stage of tooth mineralization (according to Demirjian). Univariate and multivariate general linear models were calculated

  9. Comparison of chronological and corrected ages in the gross motor assessment of low-risk preterm infants during the first year of life Comparação das idades cronológica e corrigida na avaliação motora grosseira de lactentes pré-termo com baixo risco no primeiro ano de vida

    Directory of Open Access Journals (Sweden)

    Ana Paula Restiffe

    2006-06-01

    Full Text Available OBJECTIVE: To evaluate the need of chronological age correction according to the degree of prematurity, when assessing gross motor development in preterm infants, during the first year of life. METHOD: Cohort, observational and prospective study. Alberta Infant Motor Scale (AIMS was used to evaluate 43 preterm infants with low risk for motor neurological sequelae, during the first year of corrected age. Mean scores were analyzed according to chronological and corrected ages. Children with motor neurological sequelae were excluded during follow-up. RESULTS: Gross motor mean scores in preterm infants tended to be higher when corrected age was used compared with those obtained when using chronological age, during the first twelve months. At thirteen months of corrected age, an overlapping of confidence intervals between corrected and chronological ages was observed, suggesting that from that period onwards correction for the degree of prematurity is no longer necessary. CONCLUSION: Corrected age should be used for gross motor assessment in preterm infants during the first year of life.OBJETIVO: Verificar a necessidade de corrigir a idade cronológica de acordo com o grau de prematuridade, na avaliação do desenvolvimento motor grosseiro em recém-nascidos pré-termo, durante o primeiro ano de vida. MÉTODO: Estudo coorte, observacional e prospectivo. A Escala Motora Infantil de Alberta (AIMS foi usada para avaliar 43 recém-nascidos pré-termos com baixo risco para lesão neurológica motora durante o primeiro ano de vida. A média dos escores foi analisada segundo as idades corrigidas e cronológicas. As crianças com seqüela motora neurológica foram excluídas durante o seguimento. RESULTADOS: A média dos escores do desenvolvimento motor grosseiro quando foi utilizada a idade corrigida tendeu a ser maior do que aqueles obtidos quando se utilizou a idade cronológica, durante os primeiros 12 meses. Aos 13 meses de idade corrigida, foi

  10. Prehistoric chronology of Madhya Pradesh

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.

    Madhya Pradesh is very rich in archaeological wealth, with availability of remains starting from Early Stone Age to Historical period. Several Stone Age sites have been brought to light specially in districts of Hoshangabad, Narsinghpur, Mandla...

  11. Sexual Health questions included in the Health Behaviour in School-aged Children (HBSC) Study: an international methodological pilot investigation.

    Science.gov (United States)

    Young, Honor; Költő, András; Reis, Marta; Saewyc, Elizabeth M; Moreau, Nathalie; Burke, Lorraine; Cosma, Alina; Windlin, Béat; Gabhainn, Saoirse Nic; Godeau, Emmanuelle

    2016-12-05

    This paper describes the methodological developments of the sexual health items included in the Health Behaviour in School-aged Children (HBSC) study since their mandatory inclusion in the study in 2002. The current methodological, ethical and pedagogical challenges in measuring young people's sexual health behaviours are discussed along with the issues associated with the sexual health items introduced to the HBSC study in 2002. The development and piloting of new cross-national items for use in the 2013/14 HBSC data collection are presented and discussed. An international pilot study was undertaken to determine the impact of these proposed changes. Questionnaires and classroom discussion groups were conducted in five pilot countries in 2012/2013 (France, Hungary, Ireland, Portugal and Romania) with a total of 612 school-aged children (age M = 15.55 years, SD = 0.95). The majority of participants in each country provided positive feedback about the appropriateness of the questions. Some small cross-national differences were found in the self-reported quantitative data relating to the appropriateness of the questions (χ 2  = 22.831, df = 9, p = .007, V = .117). Qualitative feedback suggests that for the vast majority of students the phrasing and age-targeting of the questions were considered appropriate. With the exception of a small number of respondents who commented on the clarity and/or personal nature of the content, no specific issues with the questions were identified. These findings provide guidance on the answerability (including the extent of missing and inconsistent data), understandability, acceptability (including in different cultures) and relevance of questions to potential participants. The findings from the pilot study suggest that in general, the questions are understandable, acceptable, and of a high priority to the target population, and that the simplification has significantly reduced the proportion of missing data

  12. Sexual Health questions included in the Health Behaviour in School-aged Children (HBSC Study: an international methodological pilot investigation

    Directory of Open Access Journals (Sweden)

    Honor Young

    2016-12-01

    Full Text Available Abstract Background This paper describes the methodological developments of the sexual health items included in the Health Behaviour in School-aged Children (HBSC study since their mandatory inclusion in the study in 2002. The current methodological, ethical and pedagogical challenges in measuring young people’s sexual health behaviours are discussed along with the issues associated with the sexual health items introduced to the HBSC study in 2002. The development and piloting of new cross-national items for use in the 2013/14 HBSC data collection are presented and discussed. Methods An international pilot study was undertaken to determine the impact of these proposed changes. Questionnaires and classroom discussion groups were conducted in five pilot countries in 2012/2013 (France, Hungary, Ireland, Portugal and Romania with a total of 612 school-aged children (age M = 15.55 years, SD = 0.95. Results The majority of participants in each country provided positive feedback about the appropriateness of the questions. Some small cross-national differences were found in the self-reported quantitative data relating to the appropriateness of the questions (χ2 = 22.831, df = 9, p = .007, V = .117. Qualitative feedback suggests that for the vast majority of students the phrasing and age-targeting of the questions were considered appropriate. With the exception of a small number of respondents who commented on the clarity and/or personal nature of the content, no specific issues with the questions were identified. Conclusions These findings provide guidance on the answerability (including the extent of missing and inconsistent data, understandability, acceptability (including in different cultures and relevance of questions to potential participants. The findings from the pilot study suggest that in general, the questions are understandable, acceptable, and of a high priority to the target population, and that the

  13. Chronology of the early period of the Ananyino cultural and historical area

    Directory of Open Access Journals (Sweden)

    Kuzminykh Sergei V.

    2014-09-01

    Full Text Available Problems related to the chronology of the early period in the Ananyino cultural and historical area development are discussed in the article. The chronology is based upon the objects imported from the Black Sea region, Northern Caucasus and Transcaucasia and their Ananyino replicas or imitations. Radiocarbon dates have also been taken into account. The period under consideration is divided into two stages (I-1 and I-2. They are characterized by differing technological facilities that had determined the appearance of a differing set of material culture objects. The first stage, the transition from the Bronze Age to the Early Iron Age, is dated within the 9th to mid-8th century BC. The second phase (mid-8th to first quarter/first half of the 7th century BC is associated with the spread of Caucasian imports in the Volga-Kama area and mostly in the post-Maklasheevka culture sites. On the basis of these imports it is possible to claim that the Ananyino area was included into the international trade and exchange system of Eastern Europe, the Caucasus and Transcaucasia. Monuments of the early period of the Ananyino cultural and historical area are primarily synchronized with the pre-Scythian funeral monuments of the steppe zone of Eastern Europe and the Caucasus.

  14. Association of Klotho and interleukin 6 gene polymorphisms with aging in Han Chinese population.

    Science.gov (United States)

    Zhang, W-G; Bai, X-J; Chen, D-P; Lv, Y; Sun, X-F; Cai, G-Y; Bai, X-Y; Chen, X-M

    2014-12-01

    Certain gene polymorphisms are associated with human aging. This study investigated polymorphisms of a metabolism-related gene, Klotho, and an inflammatory gene, IL6, for association with the aging process in a healthy Han Chinese population. A total of 482 healthy subjects were recruited and divided into aging and young groups according to chronological age and biological age. Snapshots were used to detect a Klotho gene tag SNP (rs571118) and the F-SNPs rs9536314 (F352V) and rs9527025 (C370S), and an interleukin 6 (IL-6) gene tag SNP (rs1524107) and the F-SNPs rs1800795 (-174G/C) and rs1800796 (-572G/C). Klotho F352V and IL-6-174G/C was G homozygous, C370S was T homozygous while IL-6-572G/C MAF less than 5%. There was a statistically significant difference in the Klotho rs571118 SNP between chronological age groups, but not biological age groups. However, other SNPs, including IL-6 gene SNPs, didn't correlate with age in the Han Chinese population. Human aging is a complex process that includes chronological and biological aging. Our current data showed that Klotho gene rs571118 SNP was associated with chronological aging, but not biological aging, in a Han Chinese population. Further study will investigate genetic build up for the difference between chronological and biological aging.

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

    International Nuclear Information System (INIS)

    Choi, Joon-Seok; Lee, Cheol-Koo

    2013-01-01

    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

  16. 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.

  17. Absolute chronology and stratigraphy of Lepenski Vir

    Directory of Open Access Journals (Sweden)

    Borić Dušan

    2007-01-01

    Full Text Available In the last decade, a number of specialist analyses were made on the material from old excavations of Mesolithic-Neolithic sites in the Danube Gorges. These new results altered significantly our understanding of the Lepenski Vir culture. The question of chronology of this regional phenomenon has been acute since the discovery of Lepenski Vir in the 1960s, and it remains of key importance for understanding the character of Mesolithic-Neolithic transformations in this and the neighbouring regions. The most heated debate was fuelled by the initial stratigraphic and chronological attribution of the type-site itself. There remained the question about the adequate dating of the most prominent phase at this site characterized by buildings with trapezoidal bases covered with limestone floors and with rectangular stone-lined hearths placed in the centre of these features. There have been suggestions that these features also contain Early Neolithic Starčevo type pottery and other similar items of material culture and should thus be dated to the Early Neolithic historical context. Moreover, the first series of conventional radiocarbon determinations (21 dates also suggested that the absolute chronology of these features should be confined to the period from around 6400-5500 cal BC (Fig. 1. Due to the importance of defining more precisely the chronology for the start of construction of these particular features at Lepenski Vir and for establishing the life-span of these buildings and their associated material culture, we have AMS (Accelerator Mass Spectrometry dated a number of contexts from this site. The results are presented in this paper. The project was made possible through the Oxford Radiocarbon Accelerate Dating Service (ORADS programme funded by the Arts and Humanities Research Council (AHRC and the Natural Environment Research Council (NERC of the Great Britain. Apart from those dates presented in this paper, there are 29 previously published

  18. Reconstructing SWE from a ponderosa pine chronology, Boise Front, Idaho

    Science.gov (United States)

    Wilkins, D. E.; Cutter, A.

    2012-12-01

    Changing climate in the intermountain western US is expected to include changes in precipitation amounts and timing. One change anticipated is a the development of a trend toward earlier snowmelt and subsequent runoff. Snow water equivalent (SWE) data of snow pack recorded at SNOTEL sites is limited to the past 30 years, but by using tree rings we are able to reconstruct SWE at various points in the water season (January - May). A tree-ring chronology dating to the 1600's was developed using cores collected from ponderosa pine in the foothills above Boise, Idaho. Using a 100 year smoothing spline, the chronology shows a moderate (r = 0.40) correlation with prior water year late season (May) SWE recorded at the More's Creek Summit SNOTEL site NE of Boise. This paper examines the reconstructed SWE for the past 300 years, as well as the influence of climatic teleconnections on the region's precipitation.

  19. 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.

  20. VSNL1 Co-expression networks in aging include calcium signaling, synaptic plasticity, and Alzheimer’s disease pathways

    Directory of Open Access Journals (Sweden)

    C W Lin

    2015-03-01

    Full Text Available The Visinin-like 1 (VSNL1 gene encodes Visinin-like protein 1, a peripheral biomarker for Alzheimer disease (AD. Little is known, however, about normal VSNL1 expression in brain and the biologic networks in which it participates. Frontal cortex gray matter from 209 subjects without neurodegenerative or psychiatric illness, ranging in age from 16–91, were processed on Affymetrix GeneChip 1.1 ST and Human SNP Array 6.0. VSNL1 expression was unaffected by age and sex, and not significantly associated with SNPs in cis or trans. VSNL1 was significantly co-expressed with genes in pathways for Calcium Signaling, AD, Long Term Potentiation, Long Term Depression, and Trafficking of AMPA Receptors. The association with AD was driven, in part, by correlation with amyloid precursor protein (APP expression. These findings provide an unbiased link between VSNL1 and molecular mechanisms of AD, including pathways implicated in synaptic pathology in AD. Whether APP may drive increased VSNL1 expression, VSNL1 drives increased APP expression, or both are downstream of common pathogenic regulators will need to be evaluated in model systems.

  1. Sequence and chronology of the Cuerpo de Hombre paleoglacier (Iberian Central System) during the last glacial cycle

    Science.gov (United States)

    Carrasco, Rosa M.; Pedraza, Javier; Domínguez-Villar, David; Willenbring, Jane K.; Villa, Javier

    2015-12-01

    marked by the indicators and its chronology confirm that the whole of the Late Glacial sequence identified in Cuerpo de Hombre can be correlated with the traditionally established in northern Europe (climatic periods or stadials and interstadials): Oldest Dryas-Bølling-Older Dryas-Allerød-Younger Dryas. The minimum ages obtained for the cold periods (stadials) in this sequence in the Cuerpo de Hombre paleoglacier are (respectively): ∼17.5 ka, ∼13.9 ka and ∼11.1 ka. This complete sequence of the Late Glacial Period, including the stadials Older and Younger Dryas, had not been previously identified in any of the paleoglaciers in the Iberian Central System.

  2. Retrospective cohort study shows that the risks for retinopathy of prematurity included birth age and weight, medical conditions and treatment.

    Science.gov (United States)

    Ali, Aliaa A; Gomaa, Nancy A S; Awadein, Ahmed R; Al-Hayouti, Huda H; Hegazy, Ahmed I

    2017-12-01

    This study described the characteristics and risk factors of neonates who developed retinopathy of prematurity (ROP) and severe treatable ROP in two Egyptian neonatal intensive care units (NICUs). This retrospective cohort study comprised 108 preterm neonates who were screened for ROP after being admitted to the two NICUs run by Cairo University Hospital from June 2014 to May 2015. Patients were examined using digital fundus photography and indirect ophthalmoscopy was performed if ROP was detected. Retinopathy of prematurity occurred in 75 patients. Late-onset sepsis, ventilation and hypercapnia were independently associated with ROP. Patients who developed severe treatable ROP had a younger gestational age (GA) than patients who did not develop ROP or developed mild or moderate ROP (29 weeks, range 27-33 weeks versus 32 weeks, range 28-36 weeks, p = 0.002) and a lower birthweight (1200 g, range 980-1590 g versus 1460 g, range 770-2475 g, p = 0.029). The risk factors associated with severe treatable ROP included the duration of admission, the duration of incubator oxygen, late-onset sepsis, intraventricular haemorrhage, total parenteral nutrition and the duration of caffeine citrate therapy. This study showed that the risks for ROP were wide-ranging and included GA and weight, medical conditions and treatment. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  3. Radiocarbon chronology of palsas in Bol'shezemel'skaya tundra

    International Nuclear Information System (INIS)

    Vasil'chuk, Yu.K.; Vasil'chuk, A.K.; Sulerzhitskij, L.D.; Budantseva, N.A.; Volkova, E.M.; Chizhova, Yu.N.

    2003-01-01

    The age of the peat, overlapping the swelling hillocks under different geocryologic conditions in the South and North of the Bol'shezemel'skaya tundra, located in the North-East of the European part of Russia, is determined through the method of the radiocarbon dating. The similarities and differences in the paleodynamics of the swelling hillocks at various average annual ground temperatures are identified on the basis of the obtained chronological data, covering the period from 8860 years ago up to the present time [ru

  4. Mid-Late Pleistocene OSL chronology in western Amazonia and implications for the transcontinental Amazon pathway

    Science.gov (United States)

    Rossetti, Dilce F.; Cohen, Marcelo C. L.; Tatumi, Sonia H.; Sawakuchi, André O.; Cremon, Édipo H.; Mittani, Juan C. R.; Bertani, Thiago C.; Munita, Casimiro J. A. S.; Tudela, Diego R. G.; Yee, Márcio; Moya, Gabriela

    2015-12-01

    The origin of the transcontinental Amazon drainage system remains unrevealed. Sedimentary deposits formed from the Neogene in the Amazonas and Solimões Basins constitute natural archives for reconstructing this event in space and time. However, paleoenvironmental and chronological analyses focusing on these deposits, or even their basic mapping, are still scarce to allow such investigation. In this context, primary interests are fluvial strata related to the lithostratigraphic Içá Formation, mapped over a widespread area in western Amazonian lowlands. Although long regarded as Plio-Pleistocene in age, this unit has not yet been dated and its overall depositional setting remains largely undescribed. The main goal of the present work is to contribute for improving facies analysis and chronology of these deposits, approaching an area in southwestern Amazonia and another in northern Amazonia, which are located more than 1000 km apart. Despite this great distance, the sedimentological and chronological characteristics of deposits from these two areas are analogous. Hence, facies analysis revealed paleoenvironments including active channel, abandoned channel, point bar, crevasse splay and floodplain, which are altogether compatible with meandering fluvial systems. Similarly, optically stimulated luminescence (OSL) dating revealed thirty three ages ranging from 65.4 ± 16.9 to 219.6 ± 25.1 ky (in addition to three outliners of 54.0 ± 7.6, 337.3 ± 36.9 and 346.6 ± 48.6 ky), and nine 97.1 ± 9.9 to 254.8 ± 23.8 ky for the areas in southwestern and northern Amazonia, respectively. These data lead to establish that deposits mapped as Içá Formation over a vast area of western Brazilian Amazonia have a Mid-Late Pleistocene age, rather than the previously inferred Plio-Pleistocene age. It follows that if Plio-Pleistocene deposits exist in this region they remain to be dated and must be restricted to a narrow belt in western Amazonia, as well as isolated occurrences

  5. Prevalence of dental fluorosis in children taking part in an oral health programme including fluoride tablet supplements from the age of 2 years

    DEFF Research Database (Denmark)

    Eckersten, Charlotte; Pylvänen, Lena; Schröder, Ulla

    2010-01-01

    To investigate the prevalence of dental fluorosis in children who had participated in an oral health programme between the ages 2-5 years, including fluoride tablets from the age of 2 years.......To investigate the prevalence of dental fluorosis in children who had participated in an oral health programme between the ages 2-5 years, including fluoride tablets from the age of 2 years....

  6. Climatically sensitive tree-ring chronologies from Crimea, Ukraine

    Science.gov (United States)

    Solomina, O.; Davi, N.; D Arrigo, R.

    2003-04-01

    Several tree species in Crimea can reach ages of 1000 years or more (Crimea..., 1999), including Taxus baccata L., Arbutus andrachne L., Quercus pubescens Willd, Quercus petraea (Mattuschka) Liebl., Quercus robur L., Juniperus excelsa M.B., and Pistacia mutica Fisch.et Mey. In September 2002, we collected samples from several long-lived tree sites described in the literature (Vulf, 1948, Ivanenko, 1951, Ena, 1983, Podgorniy, 1990), located in the mountains of Central Crimea (Sokolinoye, Chufut-Kale, Chelter) and on the coast of the Black Sea (Ai-Todor, Kharaks, Ai-Petri). The trees sampled generally had 300-350 rings. At Ai-Todor, most oaks, junipers, and pistachio showed decay. However, enough samples of oak, juniper and pine were collected to build three chronologies with good replication over the last 350 years. Long meteorological records (for Sevastopol since 1821, Ai-Petri and Yalta since the 1880's) as well as detailed historical data on extreme climatic events since 1687 (summarized by Borisov 1956) are available for this area and can be used to calibrate and verify the tree growth/climate models. Resulting dendroclimatic reconstructions will be the first from this region. The tree-ring time-series may also be used for archaeological dating of historical wood from several medieval fortresses, towns and palaces. In turn, the archaeological wood could be used to extend the tree-ring time series. Stalactites and stalagmites (Dubliansky, 1977) found in numerous caves, as well as 4000-years old laminated lake sediments (Shostakovich, 1934) are also potentially important sources of paleoclimatic information in the area.

  7. Evolução do perfil neuromotor e capacidade funcional de mulheres fisicamente ativas de acordo com a idade cronológica Evolución del perfil neuromotor y la capacidad funcional de mujeres fisicamente activas de acuerdo con la edad cronológica Evolution of neuromotor profile and functional capacity of physically active women according to chronological age

    Directory of Open Access Journals (Sweden)

    Sandra Mahecha Matsudo

    2003-11-01

    (: 65 ± 6.6 years engaged in an aerobic program, twice a week, 50 minutes per session during 5.4 ± 3.0 years and divided in three age groups: 50-59 (n: 23; 60-69 (n: 60; 70-79 (n: 34. Motor function and mobility tests included: lower and upper limb strength, agility, trunk flexibility, velocity of rising from a chair, static balance, gait speed and maximum gait speed. Results at the base line and in two evaluations made at six-month interval were compared using a Two Way ANOVA, with a post-hoc Bonferroni. RESULTS: There were no differences regarding neuromotor performance, although velocity of rising from a chair and gait speed evidenced significant differences in groups 50-59 and 60-69 years, showing better results (10-20%; and for maximum gait speed there was an increase (8% in 60-79 age groups. CONCLUSION: Present results suggest that physical fitness and functional capacity evolution had a similar pattern among physically active women, regardless of chronological age. This evolution supports the hypothesis of regular physical activity as a powerful tool to promote health, being of utmost importance to a healthy aging.

  8. Yearly Data for Spoken Language Preferences of Supplemental Security Income Aged Applicants (FY 2016, including 53rd week)

    Data.gov (United States)

    Social Security Administration — This dataset provides annual volume of SSI Aged initial claims at the national level from federal fiscal year 2016 shown two ways—we base one on a 52-week reporting...

  9. Quarterly Data for Asian & Pacific Islander Languages, Supplemental Security Income Initial Claims (Aged) (FY 2016, including 53rd week)

    Data.gov (United States)

    Social Security Administration — This dataset provides quarterly volumes of SSI Aged initial claims at the national level from federal fiscal year 2016 with quarter 4 shown two ways—we base one on a...

  10. Brain Age in Early Stages of Bipolar Disorders or Schizophrenia.

    Science.gov (United States)

    Hajek, Tomas; Franke, Katja; Kolenic, Marian; Capkova, Jana; Matejka, Martin; Propper, Lukas; Uher, Rudolf; Stopkova, Pavla; Novak, Tomas; Paus, Tomas; Kopecek, Miloslav; Spaniel, Filip; Alda, Martin

    2017-12-20

    The greater presence of neurodevelopmental antecedants may differentiate schizophrenia from bipolar disorders (BD). Machine learning/pattern recognition allows us to estimate the biological age of the brain from structural magnetic resonance imaging scans (MRI). The discrepancy between brain and chronological age could contribute to early detection and differentiation of BD and schizophrenia. We estimated brain age in 2 studies focusing on early stages of schizophrenia or BD. In the first study, we recruited 43 participants with first episode of schizophrenia-spectrum disorders (FES) and 43 controls. In the second study, we included 96 offspring of bipolar parents (48 unaffected, 48 affected) and 60 controls. We used relevance vector regression trained on an independent sample of 504 controls to estimate the brain age of study participants from structural MRI. We calculated the brain-age gap estimate (BrainAGE) score by subtracting the chronological age from the brain age. Participants with FES had higher BrainAGE scores than controls (F(1, 83) = 8.79, corrected P = .008, Cohen's d = 0.64). Their brain age was on average 2.64 ± 4.15 years greater than their chronological age (matched t(42) = 4.36, P stages of BD showed comparable BrainAGE scores to controls (F(2,149) = 1.04, corrected P = .70, η2 = 0.01) and comparable brain and chronological age. Early stages of schizophrenia, but not early stages of BD, were associated with advanced BrainAGE scores. Participants with FES showed neurostructural alterations, which made their brains appear 2.64 years older than their chronological age. BrainAGE scores could aid in early differential diagnosis between BD and schizophrenia. © The Author(s) 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com

  11. Chronological narratives from smoking initiation through to pregnancy of Indigenous Australian women: A qualitative study.

    Science.gov (United States)

    Gould, Gillian S; Bovill, Michelle; Clarke, Marilyn J; Gruppetta, Maree; Cadet-James, Yvonne; Bonevski, Billie

    2017-09-01

    One in two Indigenous Australian pregnant women smoke, yet little is known about their trajectory of smoking. This study aimed to explore Aboriginal women's narratives from starting smoking through to pregnancy. A female Aboriginal Researcher conducted individual face-to-face interviews with 20 Aboriginal women from New South Wales, Australia. Recruitment, through Aboriginal services and community networks, continued until saturation was reached. Audio-recorded transcripts were independently open coded by two researchers, inductively analysed and reported using a three-dimensional structure of looking backwards, forwards, inwards, outwards and a sense of place, to elucidate the chronology of events, life stages, characters, environments, and turning points of the stories. A chronology emerged from smoking initiation in childhood, coming of age, becoming pregnant, through to attempts at quitting, and relapse post-partum. Several new themes emerged: the role mothers play in women's smoking and quitting; the contribution of nausea to spontaneous quitting; depression as a barrier to quitting; and the hopes of women for their own and their children's future. The epiphany of pregnancy was a key turning point for many - including the interplay of successive pregnancies; and the intensity of expressed regret. Aboriginal women report multiple influences in the progression of early smoking to pregnancy and beyond. Potential opportunities to intervene include: a) childhood, coming of age, pregnancy, post-natal, in-between births; b) key influencers; c) environments, and d) targeting concurrent substance use. Morning sickness appears to be a natural deterrent to continued smoking. Depression, and its relationship to smoking and quitting in Australian Indigenous pregnant women, requires further research. Copyright © 2017. Published by Elsevier Ltd.

  12. 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.

  13. Developing a patient and family research advisory panel to include people with significant disease, multimorbidity and advanced age.

    Science.gov (United States)

    Portalupi, Laura B; Lewis, Carmen L; Miller, Carl D; Whiteman-Jones, Kerry L; Sather, Kay A; Nease, Donald E; Matlock, Daniel D

    2017-06-01

    People who have experienced illness due to significant disease, multimorbidity and/or advanced age are high utilizers of the health care system. Yet this population has had little formal opportunity to participate in guiding the health care research agenda, and few mechanisms exist for researchers to engage this population in an efficient way. We describe the process of developing a standing patient and family advisory panel to incorporate this population's voice into research in the USA. The panel was created at the University of Colorado. Preliminary panel development consisted of a needs assessment, information gathering and participant recruitment. We collected feedback from researchers who consulted with the panel and from panel members in order to better understand the experience from the patient and family member perspective. The patient and family research advisory panel consists of eight advisors who have experience with significant disease, multimorbidity and/or advanced age, two physicians and a program manager. The panel meets every other month for 2 hours with the main purpose of advising diverse researchers on health care studies. People with significant disease, multimorbidity and/or advanced age represent a growing demographic in the USA, and their engagement in research is essential as the model of health care delivery moves from volume to value. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. 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

  15. Gamma spectrometry for chronology of recent sediments

    International Nuclear Information System (INIS)

    Pittauerova, Daniela

    2013-01-01

    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). 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 210 Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide 226 Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member 222 Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported 210 Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of 214 Pb and 214 Bi towards radioactive equilibrium with 226 Ra in different containers were evaluated for analyses of 226 Ra. Direct analyses of 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 when combined profiles obtained from short

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

    DEFF Research Database (Denmark)

    Connelly, James; 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...

  17. Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia

    DEFF Research Database (Denmark)

    Sutikna, Thomas; Tocheri, Matthew W.; Morwood, Michael J.

    2016-01-01

    artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from...

  18. Analysis of biweight site chronologies: relative weights of individual trees over time

    Science.gov (United States)

    Kurt H. Riitters

    1990-01-01

    The relative weights on individual trees in a biweight site chronology can indicate the consistency of tree growth responses to macroclimate and can be the basis for stratifying trees in climate-growth analyses. This was explored with 45 years of ring-width indices for 200 trees from five even-aged jack pine (Pinus hanksiana Lamb.) stands. Average individual-tree...

  19. Synergistic effect of high charge and energy particle radiation and chronological age on biomarkers of oxidative stress and tissue degeneration: a ground-based study using the vertebrate laboratory model organism Oryzias latipes.

    Directory of Open Access Journals (Sweden)

    Xuan Zheng

    Full Text Available High charge and energy (HZE particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish, were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration.

  20. Date prints on stranded macroplastics: Marine litter as a chronological marker in recent coastal deposits

    Science.gov (United States)

    Sander, Lasse

    2017-04-01

    Plastic is a collective term describing a group of synthetic materials, most of which were invented over the course of the last century. Already in the 1970s, the magnitude of plastic pollution has been recognized as an issue of concern for the global marine environment. It is hence no longer a rare event to encounter plastic fragments and objects in coastal or marine deposits. Plastic holds a chronological indication: a deposit containing plastic must be younger than the invention of the material. The potential of this approach was tested in an investigation into the spatial distribution of stranded macroplastics in recent overwash deposits in SW Denmark. Larger litter items can be surveyed as discrete objects and allow the retrieval of more precise, though indirect age-information, such as production-date prints. A subgroup of >110 georeferenced surface samples containing date information were surveyed in summer 2015. Objects with ages from the late 1970s until 2014 were encountered. The distribution of the litter was clearly non-random in relation to overwash morphology, and based on the collected samples, it was possible to reconstruct indication on both the timing and the extent of extreme events since the 1990s. These observations were cross-compared with a dense time series of satellite images and orthophotos. It is proposed that an improved interpretation of indications from the plastic record may be obtained by broader surveys including additional parameters, such as the exact location, elevation, chemical composition, assemblage, origin, product design, decay, fracturing or the colonization by marine sessile organisms, from all encountered macroplastic objects. If calibrated properly, the plastic assemblages may serve as fast, cheap and reliable chronological markers in recent coastal deposits.

  1. 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.

  2. A developing chronology for prehistoric 'moated sites' in northeast Thailand

    International Nuclear Information System (INIS)

    McGrath, R.J.; Boyd, W.E.

    1999-01-01

    Full text: Many mounded Iron Age occupation sites in the Mun River Valley,N.E. Thailand are characterised by distinctive encircling earthworks, these are commonly known as 'moated sites'. The first excavations of any significance within the moats themselves at six sites -Noen U-Loke, Non Muang Khao, Ban Non Khrua Chut, Ban Non Ngiu, Ban Makham Thae and Ban Non Wat - in the form of long trenches have been carried out to enable detailed examination of their structure. Significantly, the surficial morphology of the moats, and the notable regularity of shape and patterning of the moats in plan, usually does not accurately reflect the buried sectional morphology of incised channel features, which are in no way expressed on the surface. Buried channels beneath the edge of the mounds as well as the surrounding moat banks have also been revealed. Stratigraphic and geomorphic relationships of the buried features imply critical chronological relationships which need to be tested to allow full development of a model for the evolution of the archaeological sites. Extremely small quantities of charcoal and shells obtained from the buried features has necessitated the need for AMS dating to develop the chronology for the development, use and decline of the moated features and channels. The dating is an ongoing process, however, results thus far obtained supports the development of older channels towards the archaeological mounds, and yet older buried channels under the sites

  3. Diffusion artifacts in dating by stepwise thermal release of rare gases. [Ar isotope lunar chronology

    Science.gov (United States)

    Huneke, J. C.

    1976-01-01

    It is demonstrated that the age of an isochron of apparent age plateau can be easily altered during a thermal release experiment, and that constant rare gas compositions can be observed which are artifacts of the experimental technique and are not chronologically meaningful. Examples are selected from 40Ar-39Ar dating of lunar samples in which anomalous variations in apparent ages can be ascribed to such experimental artifacts.

  4. The impact of medium acidity on the chronological life span of Saccharomyces cerevisiae - lipids, signaling cascades, mitochondrial and vacuolar functions.

    Science.gov (United States)

    Yucel, Esra B; Eraslan, Serpil; Ulgen, Kutlu O

    2014-02-01

    Because of its multifactorial nature, aging is one of the most complicated cell phenomena known. A systems biology approach, which aims to understand the organism as a whole rather than concentrate on the behaviors of individual genes, thus comprises a seamless tool for investigating the aging machinery, which arises mainly as a result of degeneration of the collaboration between signaling and regulatory pathways. In the present study, the effects of medium buffering on the chronological life span are investigated via transcriptome analyses and subsequent integration of the data obtained with the chronological aging network of yeast. The comparative inquiry of transcriptome data of young and old cells grown in buffered and unbuffered media reveals new roles for pH control (e.g. the re-organization of lipid metabolism and intracellular signaling cascades) that have beneficial consequences on chronological longevity. Integration of the transcriptome data onto the aging network, as well as validation experiments, suggest that Snf1p is a possible intermediate player in the interjunction of sphingolipid and ergosterol metabolisms with extracellular pH control with respect to regulation of the chronological life span. Consequently, a more detailed insight of the chronological aging mechanism of yeast is obtained. The results of the present study provide a solid basis for further research focusing on uncovering the agents that affect aging and age-related diseases in humans. © 2014 FEBS.

  5. Construction validity in equilibrium tests: chronological order in tasks presentation

    Directory of Open Access Journals (Sweden)

    Carolina Silveira

    2006-09-01

    Full Text Available The equilibrium tests of the Rosa Neto1 Motor evelopment Scale are constituted by ten tasks related to the chronological ages from 2 to 11 years and they determine the participants Motor Age. The tests presentation order is crescent from the child chronological age and the motor age is based on the success or failure in each task. The aim of this study was to analyze the construction validity of the equilibrium motor tests observing the ordering the levels of task difficulty. 76 children with 6 to 9 years of chronological age participated and were assigned in two groups: control group, tests presentation in increased order; and inverted group, tests presentation in decreased order. The results did not revealed statistical significant differences between groups, which indicatethat the presentation order of the tests did not interfere in the children performance, independently of the chronological age. Low success rates occurred in some specific tasks followed by success in advanced tasks. As the results revealed that the participants could perform the tasks after that in which the failure happened the motor age ascribed by the Motor Development Scale can underestimate the children motor development. The variation of the children performance in the tasks suggests that the motor development process is nonlinear. The equilibrium motor tasks purposed in the Motor Development Scale show construction validity. RESUMO Os testes de equilíbrio da Escala de Desenvolvimento Motor de Rosa Neto1 são constituídos por dez tarefas correspondentes às idades cronológicas de 2 a 11 anos e determinam a Idade Motora dos participantes. A ordem de apresentação dos testes é crescente, partindo da idade cronológica da criança e a idade motora baseia-se no sucesso ou fracasso em cada tarefa. O objetivo deste estudo foi analisar a validade de construção dos testes motores em equilíbrio, observando a ordenação e os graus de dificuldade da tarefa. Participaram

  6. Resveratrol Enhances Neuroplastic Changes, Including Hippocampal Neurogenesis, and Memory in Balb/C Mice at Six Months of Age

    Science.gov (United States)

    Torres-Pérez, Mario; Tellez-Ballesteros, Ruth Ivonne; Ortiz-López, Leonardo; Ichwan, Muhammad; Vega-Rivera, Nelly Maritza; Castro-García, Mario; Gómez-Sánchez, Ariadna; Kempermann, Gerd; Ramirez-Rodriguez, Gerardo Bernabe

    2015-01-01

    Resveratrol (RVTL) is a flavonoid found in red wine and has been publicized heavily as an anti-aging compound. Indeed, basic research confirms that although there is much hype in the promotion of RVTL, flavonoids such as RVTL have a wide range of biological effects. We here investigated the effects of RVTL treatment on hippocampal plasticity and memory performance in female Balb/C mice, a strain with low baseline levels of adult neurogenesis. Two weeks of treatment with RVTL (40 mg/kg) induced the production of new neurons in vivo by increasing cell survival and possibly precursor cell proliferation. In addition, RVTL decreased the number of apoptotic cells. The number of doublecortin (DCX)-expressing intermediate cells was increased. RVTL stimulated neuronal differentiation in vitro without effects on proliferation. In the dentate gyrus, RVTL promoted the formation and maturation of spines on granule cell dendrites. RVTL also improved performance in the step down passive avoidance test. The RVTL-treated mice showed increase in the levels of two key signaling proteins, phospho-Akt and phospho-PKC, suggesting the involvement of these signaling pathways. Our results support the vision that flavonoids such as resveratrol deserve further examination as plasticity-inducing compounds in the context of successful cognitive aging. PMID:26695764

  7. Resveratrol Enhances Neuroplastic Changes, Including Hippocampal Neurogenesis, and Memory in Balb/C Mice at Six Months of Age.

    Science.gov (United States)

    Torres-Pérez, Mario; Tellez-Ballesteros, Ruth Ivonne; Ortiz-López, Leonardo; Ichwan, Muhammad; Vega-Rivera, Nelly Maritza; Castro-García, Mario; Gómez-Sánchez, Ariadna; Kempermann, Gerd; Ramirez-Rodriguez, Gerardo Bernabe

    2015-01-01

    Resveratrol (RVTL) is a flavonoid found in red wine and has been publicized heavily as an anti-aging compound. Indeed, basic research confirms that although there is much hype in the promotion of RVTL, flavonoids such as RVTL have a wide range of biological effects. We here investigated the effects of RVTL treatment on hippocampal plasticity and memory performance in female Balb/C mice, a strain with low baseline levels of adult neurogenesis. Two weeks of treatment with RVTL (40 mg/kg) induced the production of new neurons in vivo by increasing cell survival and possibly precursor cell proliferation. In addition, RVTL decreased the number of apoptotic cells. The number of doublecortin (DCX)-expressing intermediate cells was increased. RVTL stimulated neuronal differentiation in vitro without effects on proliferation. In the dentate gyrus, RVTL promoted the formation and maturation of spines on granule cell dendrites. RVTL also improved performance in the step down passive avoidance test. The RVTL-treated mice showed increase in the levels of two key signaling proteins, phospho-Akt and phospho-PKC, suggesting the involvement of these signaling pathways. Our results support the vision that flavonoids such as resveratrol deserve further examination as plasticity-inducing compounds in the context of successful cognitive aging.

  8. Resveratrol Enhances Neuroplastic Changes, Including Hippocampal Neurogenesis, and Memory in Balb/C Mice at Six Months of Age.

    Directory of Open Access Journals (Sweden)

    Mario Torres-Pérez

    Full Text Available Resveratrol (RVTL is a flavonoid found in red wine and has been publicized heavily as an anti-aging compound. Indeed, basic research confirms that although there is much hype in the promotion of RVTL, flavonoids such as RVTL have a wide range of biological effects. We here investigated the effects of RVTL treatment on hippocampal plasticity and memory performance in female Balb/C mice, a strain with low baseline levels of adult neurogenesis. Two weeks of treatment with RVTL (40 mg/kg induced the production of new neurons in vivo by increasing cell survival and possibly precursor cell proliferation. In addition, RVTL decreased the number of apoptotic cells. The number of doublecortin (DCX-expressing intermediate cells was increased. RVTL stimulated neuronal differentiation in vitro without effects on proliferation. In the dentate gyrus, RVTL promoted the formation and maturation of spines on granule cell dendrites. RVTL also improved performance in the step down passive avoidance test. The RVTL-treated mice showed increase in the levels of two key signaling proteins, phospho-Akt and phospho-PKC, suggesting the involvement of these signaling pathways. Our results support the vision that flavonoids such as resveratrol deserve further examination as plasticity-inducing compounds in the context of successful cognitive aging.

  9. Age-related changes in trunk neuromuscular activation patterns during a controlled functional transfer task include amplitude and temporal synergies.

    Science.gov (United States)

    Quirk, D Adam; Hubley-Kozey, Cheryl L

    2014-12-01

    While healthy aging is associated with physiological changes that can impair control of trunk motion, few studies examine how spinal muscle responses change with increasing age. This study examined whether older (over 65 years) compared to younger (20-45 years) adults had higher overall amplitude and altered temporal recruitment patterns of trunk musculature when performing a functional transfer task. Surface electromyograms from twelve bilateral trunk muscle (24) sites were analyzed using principal component analysis, extracting amplitude and temporal features (PCs) from electromyographic waveforms. Two PCs explained 96% of the waveform variance. Three factor ANOVA models tested main effects (group, muscle and reach) and interactions for PC scores. Significant (pactivity, demonstrated continuous activation levels in specific muscle sites despite changing external moments, and had altered temporal synergies within abdominal and back musculature. In summary both older and younger adults recruit highly organized activation patterns in response to changing external moments. Differences in temporal trunk musculature recruitment patterns suggest that older adults experience different dynamic spinal stiffness and loading compared to younger adults during a functional lifting task. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Revised stratigraphy of Area 123, Koobi Fora, Kenya, and new age estimates of its fossil mammals, including hominins.

    Science.gov (United States)

    Gathogo, Patrick N; Brown, Francis H

    2006-11-01

    Recent geologic study shows that all hominins and nearly all other published mammalian fossils from Paleontological Collection Area 123, Koobi Fora, Kenya, derive from levels between the KBS Tuff (1.87+/-0.02 Ma) and the Lower Ileret Tuff (1.53+/-0.01 Ma). More specifically, the fossils derive from 53 m of section below the Lower Ileret Tuff, an interval in which beds vary markedly laterally, especially those units containing molluscs and algal stromatolites. The upper Burgi Member (approximately 2.00-1.87 Ma) crops out only in the southwestern part of Area 123. Adjacent Area 110 contains larger exposures of the member, and there the KBS Tuff is preserved as an airfall ash in lacustrine deposits and also as a fluvially redeposited ash. We observed no mammalian fossils in situ in this member in Area 123, but surface specimens have been documented in some monographic treatments. Fossil hominins from Area 123 were attributed to strata above the KBS Tuff in the 1970s, but later they were assigned to strata below the KBS Tuff (now called the upper Burgi Member). This study definitively places the Area 123 hominins in the KBS Member. Most of these hominins are between 1.60 and 1.65 myr in age, but the youngest may date to only 1.53 Ma, and the oldest, to 1.75 Ma. All are 0.15-0.30 myr younger than previously estimated. The new age estimates, in conjunction with published taxonomic attributions of fossils, suggest that at least two species of Homo coexisted in the region along with A. boisei until at least 1.65 Ma. Comparison of crania KNM-ER 1813 and KNM-ER 1470, which were believed to be of comparable age, is at the focus of the debate over whether Homo habilis sensu lato is in fact composed of two species: Homo habilis and Homo rudolfensis. These two crania are separated in time by approximately 0.25 myr, and therefore, arguments for their conspecificity no longer need to confront the issue of unusually high contemporaneous variation within a single species.

  11. Thirty years together: A chronology of U.S.-Soviet space cooperation

    Science.gov (United States)

    Portree, David S. F.

    1993-01-01

    The chronology covers 30 years of cooperation between the U.S. and the Soviet Union (and its successor, the Commonwealth of Independent States, of which the Russian Federation is the leading space power). It tracks successful cooperative projects and failed attempts at space cooperation. Included are the Dryden-Blagonravov talks; the UN Space Treaties; the Apollo Soyuz Test Project; COSPAS-SARSAT; the abortive Shuttle-Salyut discussions; widespread calls for joint manned and unmanned exploration of Mars; conjectural plans to use Energia and other Russian space hardware in ambitious future joint missions; and contemporary plans involving the U.S. Shuttle, Russian Mir, and Soyuz-TM. The chronology also includes events not directly related to space cooperation to provide context. A bibliography lists works and individuals consulted in compiling the chronology, plus works not used but relevant to the topic of space cooperation.

  12. Lack of Ach1 CoA-transferase triggers apoptosis and decreases chronological lifespan in yeast

    Directory of Open Access Journals (Sweden)

    Ivan eOrlandi

    2012-06-01

    Full Text Available ACH1 encodes a mitochondrial enzyme of Saccharomyces cerevisiae endowed with CoA-transferase activity. It catalyzes the CoASH transfer from succinyl-CoA to acetate generating acetyl-CoA. It is known that ACH1 inactivation results in growth defects on media containing acetate as a sole carbon and energy source which are particularly severe at low pH. Here, we show that chronological aging ach1 cells which accumulate a high amount of extracellular acetic acid display a reduced chronological lifespan. The faster drop of cell survival is completely abrogated by alleviating the acid stress either by a calorie restricted regimen that prevents acetic acid production or by transferring chronologically aging mutant cells to water. Moreover, the short-lived phenotype of ach1 cells is accompanied by reactive oxygen species accumulation, severe mitochondrial damage and an early insurgence of apoptosis. A similar pattern of endogenous severe oxidative stress is observed when ach1 cells are cultured using acetic acid as a carbon source under acidic conditions. On the whole, our data provide further evidence of the role of acetic acid as cell-extrinsic mediator of cell death during chronological aging and highlight a primary role of Ach1 enzymatic activity in acetic acid detoxification which is important for mitochondrial functionality.

  13. Lack of Ach1 CoA-Transferase Triggers Apoptosis and Decreases Chronological Lifespan in Yeast

    International Nuclear Information System (INIS)

    Orlandi, Ivan; Casatta, Nadia; Vai, Marina

    2012-01-01

    ACH1 encodes a mitochondrial enzyme of Saccharomyces cerevisiae endowed with CoA-transferase activity. It catalyzes the CoASH transfer from succinyl-CoA to acetate generating acetyl-CoA. It is known that ACH1 inactivation results in growth defects on media containing acetate as a sole carbon and energy source which are particularly severe at low pH. Here, we show that chronological aging ach1Δ cells which accumulate a high amount of extracellular acetic acid display a reduced chronological lifespan. The faster drop of cell survival is completely abrogated by alleviating the acid stress either by a calorie restricted regimen that prevents acetic acid production or by transferring chronologically aging mutant cells to water. Moreover, the short-lived phenotype of ach1Δ cells is accompanied by reactive oxygen species accumulation, severe mitochondrial damage, and an early insurgence of apoptosis. A similar pattern of endogenous severe oxidative stress is observed when ach1Δ cells are cultured using acetic acid as a carbon source under acidic conditions. On the whole, our data provide further evidence of the role of acetic acid as cell-extrinsic mediator of cell death during chronological aging and highlight a primary role of Ach1 enzymatic activity in acetic acid detoxification which is important for mitochondrial functionality.

  14. Comprehensive Analysis of Large Sets of Age-Related Physiological Indicators Reveals Rapid Aging around the Age of 55 Years.

    Science.gov (United States)

    Lixie, Erin; Edgeworth, Jameson; Shamir, Lior

    2015-01-01

    While many studies show a correlation between chronological age and physiological indicators, the nature of this correlation is not fully understood. To perform a comprehensive analysis of the correlation between chronological age and age-related physiological indicators. Physiological aging scores were deduced using principal component analysis from a large dataset of 1,227 variables measured in a cohort of 4,796 human subjects, and the correlation between the physiological aging scores and chronological age was assessed. Physiological age does not progress linearly or exponentially with chronological age: a more rapid physiological change is observed around the age of 55 years, followed by a mild decline until around the age of 70 years. These findings provide evidence that the progression of physiological age is not linear with that of chronological age, and that periods of mild change in physiological age are separated by periods of more rapid aging. © 2015 S. Karger AG, Basel.

  15. Guide for Operational Configuration Management Program including the adjunct programs of design reconstitution and material condition and aging management

    International Nuclear Information System (INIS)

    1993-11-01

    This standard presents program criteria and implementation guidance for an operational configuration management program for DOE nuclear and non-nuclear facilities in the operational phase. Portions of this standard are also useful for other DOE processes, activities, and programs. This Part 1 contains foreword, glossary, acronyms, bibliography, and Chapter 1 on operational configuration management program principles. Appendices are included on configuration management program interfaces, and background material and concepts for operational configuration management

  16. Thermoluminescence dating. Application to the chronology of volcanic ashes

    International Nuclear Information System (INIS)

    Pilleyre, T.

    1991-09-01

    Thermoluminescent (TL) dating is generally used for minerals heated in the past and can be used for absolute chronology of volcanic ashes but seems limited to less than 15.000 years. The aim of the thesis is the study of thermoluminescent properties of quartz for high doses and long irradiations using the red TL peak of quartz which is situated at high temperature (about 370 deg. C) to extend the method for higher ages. A theory, based on spatial correlation between electron and hole created during the same ionization, is developed. A chapter is devoted to dosimetry because of its importance in TL dating, especially alpha scintillation counting and the influence of humidity on the determination of annual dose. Volcanic samples are dated from 10.000 to 80.000 years before present

  17. Chronologies in wood and resin: AMS 14C dating of pre-Hispanic Caribbean Wood Sculpture

    Science.gov (United States)

    Joanna Ostapkowicz; Christopher Bronk-Ramsey; Fiona Brock; Tom Higham; Alex C. Wiedenhoeft; Erika Ribechini; Jeannette J. Lucejko; Samuel. Wilson

    2012-01-01

    This paper establishes a chronological framework for selected pieces of Caribbean (Tafno/Lucayan) wooden sculpture, enabling previously ahistoric artefacts to fit back into the wider corpus of pre-colonial material culture. Seventy-two 14C AMS determinations from 56 artefacts held in museum collections are reported, including 32 ceremonial

  18. MRI to determine the chronological age of Ghanaian footballers

    African Journals Online (AJOL)

    of fusion of the distal radius on magentic resonance imaging (MRI) and comparing it with the Fédération Internationale de Football. Association (FIFA) MRI grading. Methods. MRI scans of the left wrists of 86 players aspiring to play for the national U17 football team were recruited for the study during a. 'justify your inclusion ...

  19. 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.

  20. Monthly paleostreamflow reconstruction from annual tree-ring chronologies

    Science.gov (United States)

    Stagge, J. H.; Rosenberg, D. E.; DeRose, R. J.; Rittenour, T. M.

    2018-02-01

    Paleoclimate reconstructions are increasingly used to characterize annual climate variability prior to the instrumental record, to improve estimates of climate extremes, and to provide a baseline for climate-change projections. To date, paleoclimate records have seen limited engineering use to estimate hydrologic risks because water systems models and managers usually require streamflow input at the monthly scale. This study explores the hypothesis that monthly streamflows can be adequately modeled by statistically decomposing annual flow reconstructions. To test this hypothesis, a multiple linear regression model for monthly streamflow reconstruction is presented that expands the set of predictors to include annual streamflow reconstructions, reconstructions of global circulation, and potential differences among regional tree-ring chronologies related to tree species and geographic location. This approach is used to reconstruct 600 years of monthly streamflows at two sites on the Bear and Logan rivers in northern Utah. Nash-Sutcliffe Efficiencies remain above zero (0.26-0.60) for all months except April and Pearson's correlation coefficients (R) are 0.94 and 0.88 for the Bear and Logan rivers, respectively, confirming that the model can adequately reproduce monthly flows during the reference period (10/1942 to 9/2015). Incorporating a flexible transition between the previous and concurrent annual reconstructed flows was the most important factor for model skill. Expanding the model to include global climate indices and regional tree-ring chronologies produced smaller, but still significant improvements in model fit. The model presented here is the only approach currently available to reconstruct monthly streamflows directly from tree-ring chronologies and climate reconstructions, rather than using resampling of the observed record. With reasonable estimates of monthly flow that extend back in time many centuries, water managers can challenge systems models with a

  1. Neurofibromatosis: chronological history and current issues.

    Science.gov (United States)

    Antônio, João Roberto; Goloni-Bertollo, Eny Maria; Trídico, Lívia Arroyo

    2013-01-01

    Neurofibromatosis, which was first described in 1882 by Von Recklinghausen, is a genetic disease characterized by a neuroectodermal abnormality and by clinical manifestations of systemic and progressive involvement which mainly affect the skin, nervous system, bones, eyes and possibly other organs. The disease may manifest in several ways and it can vary from individual to individual. Given the wealth of information about neurofibromatosis, we attempted to present this information in different ways. In the first part of this work, we present a chronological history, which describes the evolution of the disease since the early publications about the disorder until the conclusion of this work, focusing on relevant aspects which can be used by those wishing to investigate this disease. In the second part, we present an update on the various aspects that constitute this disease.

  2. Neurofibromatosis: chronological history and current issues*

    Science.gov (United States)

    Antônio, João Roberto; Goloni-Bertollo, Eny Maria; Trídico, Lívia Arroyo

    2013-01-01

    Neurofibromatosis, which was first described in 1882 by Von Recklinghausen, is a genetic disease characterized by a neuroectodermal abnormality and by clinical manifestations of systemic and progressive involvement which mainly affect the skin, nervous system, bones, eyes and possibly other organs. The disease may manifest in several ways and it can vary from individual to individual. Given the wealth of information about neurofibromatosis, we attempted to present this information in different ways. In the first part of this work, we present a chronological history, which describes the evolution of the disease since the early publications about the disorder until the conclusion of this work, focusing on relevant aspects which can be used by those wishing to investigate this disease. In the second part, we present an update on the various aspects that constitute this disease. PMID:23793209

  3. Topical versus Chronological Organization of Lifespan Development: Does It Make a Difference in Student Retention and Understanding?

    Science.gov (United States)

    Spangler, Brooke R.; Kiel, Elizabeth J.

    2015-01-01

    This study aimed to determine whether taking a chronological approach (CA) or topical approach (TA) to teaching developmental psychology resulted in different learning outcomes. Across two semesters, in four classes, 354 students participated (M[subscript age] = 19.76, SD[subscript age] = 2.93 years), 66% identifying as female. One instructor…

  4. Palaeoanthropology, chronology, and archeology of the Matjes River Rock Shelter

    Energy Technology Data Exchange (ETDEWEB)

    Protsch, R.; Oberholzer, J.J.

    1975-11-01

    The Matjes River Rock Shelter is one of fourteen sites with Upper Pleistocene fossil hominids in Subsaharan Africa which was absolutely and relatively dated. It is one of the few sites where not only one isolated fossil hominid was dated, but hominids and fauna throughout several stratigraphic levels. Absolute dates, using a new collagen-extraction-method, were compared to radiocarbon dates run by other laboratories several years ago on shell and charcoal. This collagen method supplied a crosscheck on the accuracy of dates on organic materials commonly used for radiocarbon dating and absolute dates on bones. The stratigraphically lowest hominid (M.R.I.) could thus be absolutely and directly dated for the first time. From a chronological point of view, M.R.I. can be fitted into a sequence including such fossil hominids as Border Cave, Florisbad, Fish Hoek, Boskop, Bushman Rock Shelter, and M.R.I. The latter is a fairly recent representative of Homosapiens afer.

  5. Cranial ultrasound and chronological changes in molybdenum cofactor deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Mercedes; Dias, Anna P.; Perez-Duenas, Belen; Campistol, Jaume; Garcia-Cazorla, Angels [Hospital Sant Joan de Deu, Department of Pediatric Neurology, Paseo de Sant Joan de Deu, Barcelona (Spain); Lizarraga, Isabel [Hospital Sant Joan de Deu, Department of Neonatology, Barcelona (Spain); Reiss, Jochen [University of Goettingen, Institute for Human Genetics, Goettingen (Germany); Vilaseca, Maria A.; Artuch, Rafael [Hospital Sant Joan de Deu, Clinical Biochemistry Department, Barcelona (Spain)

    2007-10-15

    Molybdenum cofactor is essential for the function of three human enzymes: sulphite oxidase, xanthine dehydrogenase, and aldehyde oxidase. Molybdenum cofactor deficiency is a rare autosomal recessively inherited disease. Disturbed development and damage to the brain may occur as a result of accumulation of toxic levels of sulphite. The CT and MRI findings include severe early brain abnormalities and have been widely reported, but the cranial US imaging findings have seldom been reported. We report a chronological series of cranial US images obtained from an affected infant that show the rapid development of cerebral atrophy, calcifications and white matter cysts. Our report supports the utility of cranial US, a noninvasive bed-side technique, in the detection and follow-up of these rapidly changing lesions. (orig.)

  6. 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…

  7. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT : The Measuring Athlete's Risk of Cardiovascular events (MARC) study

    NARCIS (Netherlands)

    Schurink, M. M.; Braber, T. L.; Prakken, N. H. J.; Doevendans, P. A. F. M.; Backx, F. J. G.; Grobbee, D. E.; Rienks, R.; Nathoe, H. M.; Bots, M. L.; Velthuis, B. K.; Mosterd, A.

    Background Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged >= 45 years. Methods Coronary

  8. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT : The Measuring Athlete’s Risk of Cardiovascular events (MARC) study

    NARCIS (Netherlands)

    Schurink, M. M.; Braber, T. L.; Prakken, N. H J; Doevendans, P. A F M; Backx, F. J G; Grobbee, D. E.; Rienks, R.; Nathoe, H. M.; Bots, M. L.; Velthuis, B. K.; Mosterd, A.

    2017-01-01

    Background Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged ≥45 years. Methods Coronary artery

  9. The Antarctic ice core chronology (AICC2012: an optimized multi-parameter and multi-site dating approach for the last 120 thousand years

    Directory of Open Access Journals (Sweden)

    D. Veres

    2013-08-01

    . It is expected that the future contribution of both other long ice core records and other types of chronological constraints to the Datice tool will lead to further refinements in the ice core chronologies beyond the AICC2012 chronology. For the time being however, we recommend that AICC2012 be used as the preferred chronology for the Vostok, EDC, EDML and TALDICE ice core records, both over the last glacial cycle (this study, and beyond (following Bazin et al., 2013. The ages for NGRIP in AICC2012 are virtually identical to those of GICC05 for the last 60.2 ka, whereas the ages beyond are independent of those in GICC05modelext (as in the construction of AICC2012, the GICC05modelext was included only via the background scenarios and not as age markers. As such, where issues of phasing between Antarctic records included in AICC2012 and NGRIP are involved, the NGRIP ages in AICC2012 should therefore be taken to avoid introducing false offsets. However for issues involving only Greenland ice cores, there is not yet a strong basis to recommend superseding GICC05modelext as the recommended age scale for Greenland ice cores.

  10. Chronology of deep nodes in the neotropical primate phylogeny: insights from mitochondrial genomes.

    Science.gov (United States)

    Schrago, Carlos G; Menezes, Albert N; Moreira, Miguel A M; Pissinatti, Alcides; Seuánez, Hector N

    2012-01-01

    The evolution of Neotropical Primates (NP) is permeated by factors associated with the pattern of diversification and the biogeography of the major lineages. These questions can be better understood by providing a robust estimate of the chronological scenario of NP evolution, a reason why molecular dating methods have been widely applied. One aspect of especial interest is the timing of diversification of the major NP lineages (pitheciids, atelids and cebids), which may have resulted from rapid episodes of adaptive radiation, a question that requires NP divergence time estimates with accurate statistical certainty. In this study, we evaluated the primate timescale focused on the age of nodes of NP radiation. We investigated the performance of complete primate mitochondrial genomes as traditional molecular markers of primate evolution and further including original mitochondrial data from the endangered muriqui, Brachyteles arachnoides (Accession No. JX262672). Comparisons of the age estimates at NP nodes based on mitochondrial genomes with those obtained from a nuclear supermatrix showed similar degrees of uncertainty. Further molecular data and more informative calibration priors are required for a more precise understanding of the early NP diversification.

  11. Chronology of deep nodes in the neotropical primate phylogeny: insights from mitochondrial genomes.

    Directory of Open Access Journals (Sweden)

    Carlos G Schrago

    Full Text Available The evolution of Neotropical Primates (NP is permeated by factors associated with the pattern of diversification and the biogeography of the major lineages. These questions can be better understood by providing a robust estimate of the chronological scenario of NP evolution, a reason why molecular dating methods have been widely applied. One aspect of especial interest is the timing of diversification of the major NP lineages (pitheciids, atelids and cebids, which may have resulted from rapid episodes of adaptive radiation, a question that requires NP divergence time estimates with accurate statistical certainty. In this study, we evaluated the primate timescale focused on the age of nodes of NP radiation. We investigated the performance of complete primate mitochondrial genomes as traditional molecular markers of primate evolution and further including original mitochondrial data from the endangered muriqui, Brachyteles arachnoides (Accession No. JX262672. Comparisons of the age estimates at NP nodes based on mitochondrial genomes with those obtained from a nuclear supermatrix showed similar degrees of uncertainty. Further molecular data and more informative calibration priors are required for a more precise understanding of the early NP diversification.

  12. Prevalence of dental fluorosis in children taking part in an oral health programme including fluoride tablet supplements from the age of 2 years.

    Science.gov (United States)

    Eckersten, Charlotte; Pylvänen, Lena; Schröder, Ulla; Twetman, Svante; Wennhall, Inger; Matsson, Lars

    2010-09-01

    To investigate the prevalence of dental fluorosis in children who had participated in an oral health programme between the ages 2-5 years, including fluoride tablets from the age of 2 years. The study group consisted of 135 10- to 11-year-old children who had participated in the programme, including parent education, tooth-brushing instruction and prescribed fluoride tablets (0.25 mg NaF) (2-3 years: 1 tablet/day; 3-5 years: 2 tablets/day). The prevalence of dental fluorosis in the study group was compared with that in a nonintervention reference group consisting of 129 children of the same ages. The analysis was based on photos of the permanent maxillary front teeth using the Thylstrup & Fejerskov (TF) Index. No statistically significant difference in prevalence of dental fluorosis was seen between the two groups. Forty-three percent of the children in the study group and 38% in the reference group had fluorosis, the majority of a mild nature (TF-score 1). None had a TF score above 2. The pattern was the same after correction for parent reported intake of tablets at 3 and 5 years of age. Introduction of fluoride tablets at the age of 2 years did not result in increased prevalence of dental fluorosis.

  13. OxCal: versatile tool for developing paleoearthquake chronologies--a primer

    Science.gov (United States)

    Lienkaemper, J.J.; Ramsey, C.B.

    2009-01-01

    Ages of paleoearthquakes (events), i.e., evidence of earthquakes inferred from the geologic record, provide a critical constraint on estimation of the seismic hazard posed by an active fault. The radiocarbon calibration program OxCal (4.0.3 and above; Bronk Ramsey 2007, 2001) provides paleoseismologists with a straightforward but rigorous means of estimating these event ages and their uncertainties. Although initially developed for the chronologic modeling of archaeological data from diverse sources (e.g., radiocarbon, historical knowledge, etc.), OxCal is readily adaptable to other disciplines requiring chronological modeling, such as paleoseismology (Fumal et al. 2002; Lindvall et al. 2002; Kelson et al. 2006; Noriega et al. 2006; Lienkaemper and Williams 2007; Yen et al. 2008).

  14. COCOA (Theobroma cacao) Polyphenol-Rich Extract Increases the Chronological Lifespan of Saccharomyces cerevisiae.

    Science.gov (United States)

    Baiges, I; Arola, L

    2016-01-01

    BACKGROUND: Saccharomyces cerevisiae is a model organism with conserved aging pathways. Yeast chronological lifespan experiments mimic the processes involved in human non-dividing tissues, such as the nervous system or skeletal muscle, and can speed up the search for biomolecules with potential anti-aging effects before proceeding to animal studies. OBJECTIVE: To test the effectiveness of a cocoa polyphenol-rich extract (CPE) in expanding the S. cerevisiae chronological lifespan in two conditions: in the stationary phase reached after glucose depletion and under severe caloric restriction. MEASUREMENTS: Using a high-throughput method, wild-type S. cerevisiae and its mitochondrial manganese-dependent superoxide dismutase null mutant (sod2Δ) were cultured in synthetic complete dextrose medium. After 2 days, 0, 5 and 20 mg/ml of CPE were added, and viability was measured throughout the stationary phase. The effects of the major components of CPE were also evaluated. To determine yeast lifespan under severe caloric restriction conditions, cultures were washed with water 24 h after the addition of 0 and 20 mg/ml of CPE, and viability was followed over time. RESULTS : CPE increased the chronological lifespan of S. cerevisiae during the stationary phase in a dose-dependent manner. A similar increase was also observed in (sod2Δ). None of the major CPE components (theobromine, caffeine, maltodextrin, (-)-epicatechin, (+)-catechin and procyanidin B2) was able to increase the yeast lifespan. CPE further increased the yeast lifespan under severe caloric restriction. CONCLUSION: CPE increases the chronological lifespan of S. cerevisiae through a SOD2-independent mechanism. The extract also extends yeast lifespan under severe caloric restriction conditions. The high-throughput assay used makes it possible to simply and rapidly test the efficacy of a large number of compounds on yeast aging, requiring only small amounts, and is thus a convenient screening assay to accelerate

  15. Fallout isotope chronology of the near-surface sediment record of Lake Bolătău.

    Science.gov (United States)

    Bihari, Árpád; Karlik, Máté; Mîndrescu, Marcel; Szalai, Zoltán; Grădinaru, Ionela; Kern, Zoltán

    2018-01-01

    Fallout isotope ( 210 Pb ex, 137 Cs and 241 Am) based dating has been carried out on the near-surface sediment core collected from Lake Bolătău-Feredeu (Bukovina, Romania). The motivation was to improve the chronology of this recent section in connection with significant fluctuations observed in sediment accumulation rates, particle size distribution and primordial radioisotope (i.e. 40 K and 232 Th) composition. Previously only an extrapolation of a broad-range OxCal age-depth model, which was based on 8 AMS radiocarbon dates from the deeper part of a parallel sediment sequence and tentatively validated for the upper part using the double peaks of the 137 Cs activity concentration distribution, was available for the studied section (1-24 cm). Parallel to the previous 137 Cs measurement, 210 Pb and 226 Ra (for a more detailed, 210 Pb ex -based chronology), 241 Am (for an additional time-marker), as well as 40 K and 232 Th concentrations have also been determined by gamma-spectrometry. In case of the 210 Pb ex -based chronology, due to a large deviation from a pure exponential distribution, the Constant Flux (CF) model has been used for the calculation of sediment ages and accumulation rates. Although the broad-range OxCal and the CF model were broadly similar down to 22 cm, the 210 Pb ex -based ages are clearly superior in terms of uncertainty in the uppermost 12 cm, while the broad-range model has smaller uncertainty below 20 cm (>150 years). The CF model gave an average mass accumulation rate of (0.08 ± 0.03) g cm -2 yr -1 for sections 0-11 cm, and (0.03 ± 0.01) g cm -2 yr -1 for sections 12-22 cm, respectively. Significant changes have been observed in the depth distribution of both the particle size distribution and the elemental/isotopic composition of the sediment record, most likely related to the variation observable in the intensity and volume of precipitation in the catchment. The obtained high-resolution records of Lake Bolătău, including

  16. Environmental and lifestyle factors associated with perceived facial age in Chinese women.

    Directory of Open Access Journals (Sweden)

    Andrew E Mayes

    Full Text Available Perceived facial age has been proposed as a biomarker of ageing with 'looking young for one's age' linked to physical and cognitive functioning and to increased survival for Caucasians. We have investigated the environmental and lifestyle factors associated with perceived facial ageing in Chinese women. Facial photographs were collected from 250 Chinese women, aged 25-70 years in Shanghai, China. Perceived facial age was determined and related to chronological age for each participant. Lifestyle and health information was collected by questionnaire. Bivariate analyses (controlling for chronological age identified and quantified lifestyle variables associated with perceived facial age. Independent predictors of perceived age were identified by multivariate modelling. Factors which significantly associated with looking younger for one's chronological age included greater years of education (p<0.001, fewer household members (p=0.027, menopausal status (p=0.020, frequency of visiting one's doctor (p=0.013, working indoors (p<0.001, spending less time in the sun (p=0.015, moderate levels of physical activity (p=0.004, higher frequency of teeth cleaning (p<0.001 and more frequent use of facial care products: cleanser (p<0.001; moisturiser (p=0.016 or night cream (p=0.016. Overall, 36.5% of the variation in the difference between perceived and chronological age could be explained by a combination of chronological age and 6 independent lifestyle variables. We have thus identified and quantified a number of factors associated with younger appearance in Chinese women. Presentation of these factors in the context of facial appearance could provide significant motivation for the adoption of a range of healthy behaviours at the level of both individuals and populations.

  17. 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

  18. A Radiocarbon Chronology of Hunter-Gatherer Occupation from Bodega Bay, California, USA

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, M A; Russell, A D; Guilderson, T P

    2005-04-27

    The evolution of hunter-gatherer maritime adaptations in western North America has been a prominent topic of discussion among archaeologists in recent years (e.g. Arnold 1992; Erlandson and Colten 1991; Erlandson and Glassow 1997; Lightfoot 1993). Although vast coastal regions of the northeastern Pacific (for example, southern California) have been investigated in detail, our understanding of hunter-gatherer developments along the coast of northern California is limited. Previous research indicates that humans have exploited marine mammals, fish and shellfish along the northern California shoreline since the early Holocene (Schwaderer 1992). By the end of the late Holocene, some groups remained year-round on the coast subsisting primarily on marine resources (e.g. Gould 1975; Hildebrandt and Levulett 2002). However, a paucity of well-dated cultural deposits has hindered our understanding of these developments, particularly during the early and middle Holocene. The lack of a long and reliable chronological sequence has restricted our interpretations of behavioral change, including the adaptive strategies (such as foraging, mobility and settlement) used by human foragers to colonize and inhabit the coastal areas of this region. These shortcomings have also hindered comparative interpretations with other coastal and inland regions in western North America. Here we present a Holocene radiocarbon chronology of hunter-gatherer occupation based on contemporaneous samples of charcoal and Mytilus californianus (California sea mussel) shell recovered from seven archaeological sites near Bodega Bay, California. A series of 127 {sup 14}C ages reveal a chronological sequence that spans from ca. 8940-110 cal BP (1{sigma}) (7890-160 {sup 14}C yr BP = charcoal; 8934-101 {sup 14}C yr BP = shell). As part of this sequence, we report new {sup 14}C dates from the stratified cave and open-air midden deposits at Duncan's Landing (CA-SON-348/H). In addition, we present {sup 14}C

  19. Radiocarbon dating, chronologic framework, and changes in accumulation rates of holocene estuarine sediments from Chesapeake Bay

    Science.gov (United States)

    Colman, Steven M.; Baucom, P.C.; Bratton, J.F.; Cronin, T. M.; McGeehin, J.P.; Willard, D.; Zimmerman, A.R.; Vogt, P.R.

    2002-01-01

    Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelarator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210 Pb and 137 Cs data and pollen stratigraphy from the same sites. Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.

  20. Availability of Amino Acids Extends Chronological Lifespan by Suppressing Hyper-Acidification of the Environment in Saccharomyces cerevisiae

    Science.gov (United States)

    Maruyama, Yo; Ito, Toshiyuki; Kodama, Hiroaki; Matsuura, Akira

    2016-01-01

    The chronological lifespan of Saccharomyces cerevisiae represents the duration of cell survival in the postdiauxic and stationary phases. Using a prototrophic strain derived from the standard auxotrophic laboratory strain BY4742, we showed that supplementation of non-essential amino acids to a synthetic defined (SD) medium increases maximal cell growth and extends the chronological lifespan. The positive effects of amino acids can be reproduced by modulating the medium pH, indicating that amino acids contribute to chronological longevity in a cell-extrinsic manner by alleviating medium acidification. In addition, we showed that the amino acid-mediated effects on extension of chronological longevity are independent of those achieved through a reduction in the TORC1 pathway, which is mediated in a cell-intrinsic manner. Since previous studies showed that extracellular acidification causes mitochondrial dysfunction and leads to cell death, our results provide a path to premature chronological aging caused by differences in available nitrogen sources. Moreover, acidification of culture medium is generally associated with culture duration and cell density; thus, further studies are required on cell physiology of auxotrophic yeast strains during the stationary phase because an insufficient supply of essential amino acids may cause alterations in environmental conditions. PMID:26991662

  1. Availability of Amino Acids Extends Chronological Lifespan by Suppressing Hyper-Acidification of the Environment in Saccharomyces cerevisiae.

    Science.gov (United States)

    Maruyama, Yo; Ito, Toshiyuki; Kodama, Hiroaki; Matsuura, Akira

    2016-01-01

    The chronological lifespan of Saccharomyces cerevisiae represents the duration of cell survival in the postdiauxic and stationary phases. Using a prototrophic strain derived from the standard auxotrophic laboratory strain BY4742, we showed that supplementation of non-essential amino acids to a synthetic defined (SD) medium increases maximal cell growth and extends the chronological lifespan. The positive effects of amino acids can be reproduced by modulating the medium pH, indicating that amino acids contribute to chronological longevity in a cell-extrinsic manner by alleviating medium acidification. In addition, we showed that the amino acid-mediated effects on extension of chronological longevity are independent of those achieved through a reduction in the TORC1 pathway, which is mediated in a cell-intrinsic manner. Since previous studies showed that extracellular acidification causes mitochondrial dysfunction and leads to cell death, our results provide a path to premature chronological aging caused by differences in available nitrogen sources. Moreover, acidification of culture medium is generally associated with culture duration and cell density; thus, further studies are required on cell physiology of auxotrophic yeast strains during the stationary phase because an insufficient supply of essential amino acids may cause alterations in environmental conditions.

  2. Availability of Amino Acids Extends Chronological Lifespan by Suppressing Hyper-Acidification of the Environment in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Yo Maruyama

    Full Text Available The chronological lifespan of Saccharomyces cerevisiae represents the duration of cell survival in the postdiauxic and stationary phases. Using a prototrophic strain derived from the standard auxotrophic laboratory strain BY4742, we showed that supplementation of non-essential amino acids to a synthetic defined (SD medium increases maximal cell growth and extends the chronological lifespan. The positive effects of amino acids can be reproduced by modulating the medium pH, indicating that amino acids contribute to chronological longevity in a cell-extrinsic manner by alleviating medium acidification. In addition, we showed that the amino acid-mediated effects on extension of chronological longevity are independent of those achieved through a reduction in the TORC1 pathway, which is mediated in a cell-intrinsic manner. Since previous studies showed that extracellular acidification causes mitochondrial dysfunction and leads to cell death, our results provide a path to premature chronological aging caused by differences in available nitrogen sources. Moreover, acidification of culture medium is generally associated with culture duration and cell density; thus, further studies are required on cell physiology of auxotrophic yeast strains during the stationary phase because an insufficient supply of essential amino acids may cause alterations in environmental conditions.

  3. The Expanding Role of Television in College Football: A Chronology.

    Science.gov (United States)

    The Chronicle of Higher Education, 1984

    1984-01-01

    A chronology of television in college football is presented from the first televised college football game (a University of Pennsylvania game) to the Supreme Court ruling declaring that the National Collegiate Athletic Association contracts violate antitrust law. (MLW)

  4. Fine resolution AMS 14C chronology for Lunette-Lake sediment sequences, Lake Bolac, Victoria

    International Nuclear Information System (INIS)

    Cook, E.

    1998-01-01

    This study aims to provide a fine-resolution chronology for lake sediment records from Lakes Bolac and Turangmoroke, located within the drier part of the Western Plains, Victoria. These lakes are expected to be sensitive to subtle climate and vegetation variability and have long been recognised as archaeologically rich, bearing stone tools, hearth and other cultural materials dated to the late Pleistocene (Horton, 1984; former Victorian Aboriginal Survey, unpublished data). Fine-resolution chronological control has rarely been attempted in this sedimentary and (semi-arid) climatic context owing to the paucity of material available for conventional 14 C dating. However, pollen and microscopic charcoal in the lake sediments at Bolac and Turangmoroke are suitable for AMS age determination with the most important sedimentary section well within the range of 14 C making them ideal records for such a study. Recent dating results, which have substantially increased chronostratigraphic interpretation of concurrent palaeoecological and sedimentological work in progress, are presented

  5. Fine resolution AMS {sup 14}C chronology for Lunette-Lake sediment sequences, Lake Bolac, Victoria

    Energy Technology Data Exchange (ETDEWEB)

    Cook, E. [Monash University, Clayton, VIC (Australia). Centre for Palynology and Palaeoecology, Department of Geography and Environmental Science

    1998-12-31

    This study aims to provide a fine-resolution chronology for lake sediment records from Lakes Bolac and Turangmoroke, located within the drier part of the Western Plains, Victoria. These lakes are expected to be sensitive to subtle climate and vegetation variability and have long been recognised as archaeologically rich, bearing stone tools, hearth and other cultural materials dated to the late Pleistocene (Horton, 1984; former Victorian Aboriginal Survey, unpublished data). Fine-resolution chronological control has rarely been attempted in this sedimentary and (semi-arid) climatic context owing to the paucity of material available for conventional {sup 14}C dating. However, pollen and microscopic charcoal in the lake sediments at Bolac and Turangmoroke are suitable for AMS age determination with the most important sedimentary section well within the range of {sup 14}C making them ideal records for such a study. Recent dating results, which have substantially increased chronostratigraphic interpretation of concurrent palaeoecological and sedimentological work in progress, are presented

  6. Violet stimulated luminescence dating of quartz from Luochuan (Chinese loess plateau): Agreement with independent chronology up to ∼600 ka

    DEFF Research Database (Denmark)

    Ankjærgaard, C.; Guralnik, B.; Buylaert, Jan-Pieter

    2016-01-01

    demonstrate that the Multi-Aliquot Additive-Dose (MAAD) protocol produces a VSL chronology at Luochuan which is in agreement with independent ages up to ∼0.6 Ma. For a more representative environmental dose rate of ∼2 Gy/ka (∼35% lower than at Luochuan), the documented range of MAAD-VSL sensitivity (200...

  7. Radiocarbon and optically stimulated luminescence dating based chronology of a polycyclic driftsand sequence at Weerterbergen (SE Netherlands)

    NARCIS (Netherlands)

    van Mourik, J.M.; Nierop, K.G.J.; Vandenberghe, D.A.G.

    2010-01-01

    The chronology of polycyclic driftsand sequences in cultural landscapes has mainly been based on the combination of radiocarbon (14C) dating of intercalated organic horizons and pollen analysis. This approach, however, yields indirect age information for the sediment units. Also, as soils are

  8. Date prints on stranded macroplastics: Exploring the potential of marine litter assemblages as chronological markers in recent coastal deposit

    Science.gov (United States)

    Sander, L.

    2016-12-01

    Plastic is a collective term describing a group of synthetic materials developed from the early 1900s onward. The mass production of plastics began in the 1950s and already in the 1970s, the magnitude of plastic pollution has been recognized as an issue of concern for the global marine environment. Today, it is no longer a rare event to encounter plastic fragments and objects in modern coastal deposits. The presence of any form of plastic holds in itself a chronological indication (i.e. the deposit is younger than the invention of plastic). Larger items can be surveyed as discrete objects and allow the retrieval of more precise, though indirect age-information, such as production-date prints (i.e. the deposit is younger than the encountered litter item). The potential of this approach was tested in an investigation into the spatial distribution of stranded macroplastics in recent overwash deposits in SW Denmark. An amount of >110 georeferenced surface samples containing date prints were surveyed in summer 2015. Objects with ages from the late 1970s until 2014 were encountered. The distribution of the litter was clearly non-random in relation to overwash morphology, and based on the collected samples, it was possible to reconstruct indication on both the timing and the extent of extreme events since the 1990s. These observations were cross-compared with a dense time series of satellite images and orthophotos. It is proposed that an improved interpretation of indications from the plastic record may be obtained by broader surveys including additional parameters, such as the exact location, elevation, chemical composition, assemblage, origin, product design, decay, fracturing or the colonization by marine sessile organisms, from all encountered macroplastic objects. If calibrated properly, the plastic assemblages may serve as fast, cheap and reliable chronological markers in recent coastal deposits.

  9. Chronological changes in hypertensive intracerebral hemorrhages

    International Nuclear Information System (INIS)

    Takasugi, Shinsuke; Kashihara, Michiharu; Okamoto, Junji; Hondo, Hideki; Yamashita, Shigeru

    1983-01-01

    The clinical series consisted of 28 patients with hypertensive intracerebral hematoma observed in the natural course from 1976 through 1978. A total of 114 repeated computer tomographic (CT) examinations were made with an EMI-1010 or an ACTA-0100 scanner. The experimental series consisted of 26 adult mongrel dogs with intracerebral hematoma near the basal ganglia. In 20 dogs, autopsy and histological examinations were performed, and in 12 dogs a total of 31 repeated CT examinations were carried out with an EMI scanner (matrix 320 x 320, high-definition scan). In the clinical series, the time of the decrease in density beginning in the periphery of the hematoma, like the first appearance of ring enhancement and its concentric concentration toward the center of the hematoma, was not affected by the size of the hematoma. However, the time when the intracerebral hematoma was resolved did vary with the size of the hematoma. In the experimental series, the tissue reaction near the periphery of the intracerebral hematoma seemed to be a constant process. First, a necrotic layer appeared, and then this was replaced by immature connective tissue with granular cells, newly formed vessels, and reticulin fibers; finally, the immature layer was gradually transformed into mature connective tissue with collagenous fibers. Moreover, this process of change was not related to the size of the hematoma. The following correlations were suggested by a chronological observation of the CT images and the histological appearance: 1) acute stage - homogeneous high-density extending to the periphery, apperance of a necrotic layer; 2) subacute stage - decreased density spreading from the periphery and formation of ring enhancement, apperance of immature connective tissue with reticulin fibers; 3) chronic stage - concentric concentration of ring enhancement, mature connective tissue with collagenous fibers

  10. History of Science in the United States: A Chronology and Research Guide, by Clark A. Elliott, Garland Reference Library of the Humanities Vol. 1711, Garland Publishing, New York. 1996

    Directory of Open Access Journals (Sweden)

    Andrew L. Christenson

    1996-11-01

    Full Text Available There are four parts to this volume - a chronology of events by year, a chronology of leading scientists grouped by the decade in which they reached 25 years of age? a research guide, and a research bibliography. The author has written extensively on American science, including co-editing the volume Science at Harvard University (reviewed in BHA 2(1:17-19. The volume covers mostly what are termed the "hard" sciences (-.e., chemistry. biology, geology, etc. and touches upon the social sciences only rarely. The chronology. that takes up two thirds of the book, extends from ca. 1493 to 1990 and includes only three archaeological events. An example of these entries follows: "1877. ARCHAEOLOGY Ephraim George Squier (1821-1888 published Peru: Incidents of Travel and Exploration in the Land of the Incas (New York and London. Herelated his discovery of Latin American civilizations that predated the Inca. (p. 114" The scientist cohorts by decade also focuses upon the hard sciences, although three men are singled out from archaeology F. W. Putnam, N. H. Winchell, and T. M. Prodden - a peculiar sample of American archae­ologists indeed!

  11. Functional innovations of three chronological mesohexaploid Brassica rapa genomes.

    Science.gov (United States)

    Kim, Jungeun; Lee, Jeongyeo; Choi, Jae-Pil; Park, Inkyu; Yang, Kyungbong; Kim, Min Keun; Lee, Young Han; Nou, Ill-Sup; Kim, Dae-Soo; Min, Sung Ran; Park, Sang Un; Kim, HyeRan

    2014-07-18

    The Brassicaceae family is an exemplary model for studying plant polyploidy. The Brassicaceae knowledge-base includes the well-annotated Arabidopsis thaliana reference sequence; well-established evidence for three rounds of whole genome duplication (WGD); and the conservation of genomic structure, with 24 conserved genomic blocks (GBs). The recently released Brassica rapa draft genome provides an ideal opportunity to update our knowledge of the conserved genomic structures in Brassica, and to study evolutionary innovations of the mesohexaploid plant, B. rapa. Three chronological B. rapa genomes (recent, young, and old) were reconstructed with sequence divergences, revealing a trace of recursive WGD events. A total of 636 fast evolving genes were unevenly distributed throughout the recent and young genomes. The representative Gene Ontology (GO) terms for these genes were 'stress response' and 'development' both through a change in protein modification or signaling, rather than by enhancing signal recognition. In retention patterns analysis, 98% of B. rapa genes were retained as collinear gene pairs; 77% of those were singly-retained in recent or young genomes resulting from death of the ancestral copies, while others were multi-retained as long retention genes. GO enrichments indicated that single retention genes mainly function in the interpretation of genetic information, whereas, multi-retention genes were biased toward signal response, especially regarding development and defense. In the recent genome, 13,302, 5,790, and 20 gene pairs were multi-retained following Brassica whole genome triplication (WGT) events with 2, 3, and 4 homoeologous copies, respectively. Enriched GO-slim terms from B. rapa homomoelogues imply that a major effect of the B. rapa WGT may have been to acquire environmental adaptability or to change the course of development. These homoeologues seem to more frequently undergo subfunctionalization with spatial expression patterns compared with

  12. 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

  13. Coronary vascular age: An alternate means for predicting stress-induced myocardial ischemia in patients with suspected coronary artery disease.

    Science.gov (United States)

    Nappi, Carmela; Gaudieri, Valeria; Acampa, Wanda; Arumugam, Parthiban; Assante, Roberta; Zampella, Emilia; Mannarino, Teresa; Mainolfi, Ciro Gabriele; Imbriaco, Massimo; Petretta, Mario; Cuocolo, Alberto

    2018-01-22

    Coronary artery calcium (CAC) can be used to estimate vascular age in adults, providing a convenient transformation of CAC from Agatston units into a year's scale. We investigated the role of coronary vascular age in predicting stress-induced myocardial ischemia in subjects with suspected coronary artery disease (CAD). A total of 717 subjects referred to CAC scoring and 82 Rb PET/CT stress-rest myocardial perfusion imaging for suspected CAD were studied. CAC score was measured according to the Agatston method and coronary vascular age by equating estimated CAD risk for chronological age and CAC using the formula 39.1 + 7.25 × ln(CAC + 1). Stress-induced ischemia was present in 105 (15%) patients. Mean chronological age, CAC score, and coronary vascular age were higher (all P age was added to clinical variables. Including vascular age in the model, the global Chi square further increased from 68.77 to 106.38 (P age to clinical data, continuous net reclassification improvement (cNRI) was 0.57, while adding vascular age to clinical data and chronological age cNRI was 0.62. At decision curve analysis, the model including vascular age was associated with the highest net benefit compared to the model including only clinical data, to the model including chronological age and clinical data, and to a strategy considering that all patients had ischemia. The model including vascular age also showed the largest reduction in false-positive rate without missing any ischemic patients. In subjects with suspected CAD, coronary vascular age is strongly associated with stress-induced ischemia. The communication of a given vascular age would have a superior emotive impact improving observance of therapies and healthier lifestyles.

  14. Age

    Science.gov (United States)

    ... Resources About Policymakers Media ASA Member Toolkit Risks Age Explore this page: Age Do anesthesia risks increase ... can you reduce anesthesia risks in older patients? Age Age may bring wisdom but it also brings ...

  15. North Atlantic ecosystem shifts revealed by cod otolith δ15N and δ13C chronologies

    DEFF Research Database (Denmark)

    Pedersen, Jens Brøgger; Nielsen, Jens Munk; Steingrund, Petur

    . To study the link between environmental changes and ecosystem trophic structure we developed δ15N and δ13C chronologies by analyzing the organic matrix of cod otoliths from the Faroe Shelf cod population (1950-2010) and the Nuuk Fjord cod population (1927-2009). Significant correlations between δ15N & δ13C...... of organic matrix of otolith core material (Nuuk Fjord) and annual growth increments in Ocean Quahog (A. Islandica) shells will be included....

  16. A Chronology of Terrorist Attacks and Other Criminal Actions Against Maritime Targets

    Science.gov (United States)

    1983-09-01

    incidents. Other groups include the IRA, Moslem separatists in the Southern Philippines, right -wing Christian extremists in Lebanon, Polisario guerrillas... emigres , Palestinian groups, and the IRA alone account for nearly 40 percent of the terrorist attacks recorded in this chronology. These groups are...opponent of Dr. Salazar’s government. The liner was on a holiday cruise witn over 600 Portuguese, American, Dutch, Venezuelan and Spanish passengers on

  17. Stable isotopes, chronology and Bayesian models for the Viking archaeology of north-east Iceland

    OpenAIRE

    Hamilton, W. Derek; Sayle, Kerry L.

    2017-01-01

    This paper reviews the results of a long-term research project that used stable isotope analyses (δ13C, δ15N, δ34S) and Bayesian mixing models to better model the chronology for a presumed Viking Age cemetery at Hofstaðir, near Lake Mývatn in north-east Iceland. δ13C and radiocarbon dating indicated that many of the individuals consumed a large amount of marine protein, which results in a marine reservoir effect (MRE), making ages older than expected. In addition to the MRE, geological activi...

  18. Complexity, Sustainability, Justice, and Meaning: Chronological Versus Dynamical Time

    Directory of Open Access Journals (Sweden)

    Horacio Velasco

    2009-11-01

    ="font-size: small; font-family: Times New Roman;"> 

    When nonlinear dynamics came to be complemented with semiotic modulation through the implement of symbol-mediated language (a complementation subsequently termed semantic closure as first instantiated through the communicating (as opposed  to merely dynamically interacting molecular complexes of the cell, what can be termed semiotic hysteresis was born. The paper attempts to show that indefinitely evolving complexity, sustainability, justice, and meaning are indissolubly bound with chronological time in the sense of semiotic hysteresis (as afforded initially by non-cognitive semantic closure and subsequently, at least one hopes, by cognitive semantic closure: This semiotic hysteresis yields the indefinite evolutionary time of the living condition—including culture.

     

  19. 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 otolith chronologies could be used to examine responses between freshwater ecosystems and environmental variability across a range of temporal and spatial scales.

  20. Energy History Chronology from World War II to the Present [1982

    Science.gov (United States)

    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.

  1. Proxy system modeling of tree-ring isotope chronologies over the Common Era

    Science.gov (United States)

    Anchukaitis, K. J.; LeGrande, A. N.

    2017-12-01

    The Asian monsoon can be characterized in terms of both precipitation variability and atmospheric circulation across a range of spatial and temporal scales. While multicentury time series of tree-ring widths at hundreds of sites across Asia provide estimates of past rainfall, the oxygen isotope ratios of annual rings may reveal broader regional hydroclimate and atmosphere-ocean dynamics. Tree-ring oxygen isotope chronologies from Monsoon Asia have been interpreted to reflect a local 'amount effect', relative humidity, source water and seasonality, and winter snowfall. Here, we use an isotope-enabled general circulation model simulation from the NASA Goddard Institute for Space Science (GISS) Model E and a proxy system model of the oxygen isotope composition of tree-ring cellulose to interpret the large-scale and local climate controls on δ 18O chronologies. Broad-scale dominant signals are associated with a suite of covarying hydroclimate variables including growing season rainfall amounts, relative humidity, and vapor pressure deficit. Temperature and source water influences are region-dependent, as are the simulated tree-ring isotope signals associated with the El Nino Southern Oscillation (ENSO) and large-scale indices of the Asian monsoon circulation. At some locations, including southern coastal Viet Nam, local precipitation isotope ratios and the resulting simulated δ 18O tree-ring chronologies reflect upstream rainfall amounts and atmospheric circulation associated with monsoon strength and wind anomalies.

  2. Ancient Egyptian chronology and the astronomical orientation of pyramids

    Science.gov (United States)

    Spence, Kate

    2000-11-01

    The ancient Egyptian pyramids at Giza have never been accurately dated, although we know that they were built approximately around the middle of the third millennium BC. The chronologies of this period have been reconstructed from surviving lists of kings and the lengths of their reigns, but the lists are rare, seldom complete and contain known inconsistencies and errors. As a result, the existing chronologies for that period (the Old Kingdom) can be considered accurate only to about +/-100 years, a figure that radiocarbon dating cannot at present improve. Here I use trends in the orientation of Old Kingdom pyramids to demonstrate that the Egyptians aligned them to north by using the simultaneous transit of two circumpolar stars. Modelling the precession of these stars yields a date for the start of construction of the Great Pyramid that is accurate to +/-5 yr, thereby providing an anchor for the Old Kingdom chronologies.

  3. Initial chronology of a recently discovered hydrothermal field at 14°45‧N, Mid-Atlantic Ridge

    Science.gov (United States)

    Lalou, Claude; Reyss, Jean Louis; Brichet, Evelyne; Krasnov, Sergey; Stepanova, Tamara; Cherkashev, Georgiy; Markov, Vladimir

    1996-11-01

    Two expeditions of the 'Sevmorgeologija' association (1991-1994) led to the discovery of two new hydrothermal sites on the Mid Atlantic Ridge (MAR), south of the 15°20‧ North Fracture Zone, one around 14°45‧N and the other around 14°42‧N. The northern one, between 14°45‧ and 14°45.3‧N has been studied in detail. About 12 mounds have been mapped and 3 of them have been sampled using a large hydraulic grab sampler. The largest one is about 200 m long and 200 m wide. When progressively moving up on the slope of an uplifted block of the rift valley floor, the sulphide samples have revealed ages ranging from about 10 ka to 60 ka. The ages were obtained using the 230Th/234U dating method used for chronological studies of diverse hydrothermal fields. The general picture of this lateral location of the samples of different ages provides evidence of a shift in the focus of hydrothermal activity with time. Moreover, there were rejuvenation stages of hydrothermal activity, including black and white smokers.

  4. Chronology of desert margin in western India using improved luminescence dating protocols

    Science.gov (United States)

    Chauhan, Naveen; Morthekai, P.

    2017-12-01

    The present study provides improved chronology for the desert margin fluvial sediments of semi-arid region located in the Mahi river basin, western India. The sequence has preserved a near-continuous record of climate change since the Last Interglacial. An earlier attempt of dating based on feldspar IRSL chronology shows a combined effect of anomalous fading and unbleached components resulting in age inversions. The present work tries to explore the possibility of using blue light stimulated luminescence (BLSL) of quartz, infra-red stimulated luminescence (IRSL) of feldspar and the newly developed methodologies, like natural correction factor based single aliquot regeneration (NCF-SAR) protocol and decision making schemes based on distribution of doses and beta heterogeneity concept for luminescence dating of sediments. Observations suggest that quartz suffered from significant sensitivity changes during natural signal measurement and partial bleaching. A combination of NCF-SAR protocol and sample specific equivalent dose computation helped in arriving at better age estimate for present samples. The study also compares the criteria for the selection of different age models that are used at present. The age of the alluvial sequence is now bracketed between 10 ka (upper aeolian unit) and 75 ka (lowermost fluvial unit).

  5. Chronological study archaeological sites from Caninde do Sao Francisco, Sergipe state, Brazil, by thermo thermoluminescence technique

    International Nuclear Information System (INIS)

    Santos, Jose Osman dos; Munita, Casimiro S.; Valerio, Mario E. Giroldo; Vergne, Maria C. de Souza

    2005-01-01

    The ceramic vestiges rescued in the archaeological excavations have been considered important sources of chronological information because they constitute direct fossil of certain cultural periods. The Thermoluminescence Method for dating of inorganic materials has made the determination of ancient ceramics ages possible with adequate precision and accuracy. The intensity of the thermoluminescence emission is proportional to the energy deposited in the crystals, present in the pottery, by means of natural radioisotope material irradiation (U, Th, K and Rb) and cosmic rays. With the objective of determining the chronological profile of archaeological sites from 'Xingo', situated in the Caninde do Sao Francisco city, Sergipe State, Brazilian Northeast, the ages of 4 pottery samples from Justino, Sao Jose, Saco da Onca and Curituba sites were determined in this work. The ceramic collection has great expression because many ceramics are associated to mortuary rites. The acquisition of the site chronology studied in this work is a contribution to studies of ancient communities that lived in the region. The additive dose method was used to determine of the paleodose in the samples, and the TL response of 320 deg C peak as function of the added dose was linear. The annual dose rate was determined by means of the instrumental neutron activation analysis, using the U, Th, K and RB concentration from soil and own sample, which yielded an average annual dose rate of 2.89 ± 0.33 mGy.yr -1 . Using of the paleodose and annual dose rate, the ages were determined which remained between 457 - 3716 BP, value which matches with the results obtained by carbon - 14 method in the sample from burned charcoal in Justino site. (author)

  6. How old do you feel? The role of age discrimination and biological aging in subjective age.

    Directory of Open Access Journals (Sweden)

    Yannick Stephan

    Full Text Available Subjective age, or how young or old individuals experience themselves to be relative to their chronological age, is a crucial construct in gerontology. Subjective age is a significant predictor of important health outcomes, but little is known about the criteria by which individuals' subjectively evaluate their age. To identify psychosocial and biomedical factors linked to the subjective evaluation of age, this study examined whether perceived age discrimination and markers of biological aging are associated with subjective age. Participants were 4776 adults (Mage = 68 from the 2008 and 2010 waves of the Health and Retirement Study (HRS who completed measures of subjective age, age discrimination, demographic variables, self-rated health and depression, and had physical health measures, including peak expiratory flow, grip strength, waist circumference, systolic and diastolic blood pressure. Telomere length was available for a subset of participants in the 2008 wave (n = 2214. Regression analysis indicated that perceived age discrimination, lower peak expiratory flow, lower grip strength, and higher waist circumference were associated with an older subjective age, controlling for sociodemographic factors, self-rated health, and depression. In contrast, blood pressure and telomere length were not related to subjective age. These findings are consistent with the hypothesis that how old a person feels depends in part on psychosocial and biomedical factors, including the experiences of ageism and perceptible indices of fitness and biological age.

  7. Do Challenge, Task Experience or Computer Familiarity Influence the Learning of Historical Chronology from Virtual Environments in 8-9 Year Old Children?

    Science.gov (United States)

    Korallo, Liliya; Foreman, Nigel; Boyd-Davis, Stephen; Moar, Magnus; Coulson, Mark

    2012-01-01

    Studies examined the potential use of VEs in teaching historical chronology to 127 children of primary school age (8-9 years). The use of passive fly-through VEs had been found, in an earlier study, to be disadvantageous with this age group when tested for their subsequent ability to place displayed sequential events in correct chronological…

  8. Evolutionary perspectives on ageing.

    Science.gov (United States)

    Reichard, Martin

    2017-10-01

    From an evolutionary perspective, ageing is a decrease in fitness with chronological age - expressed by an increase in mortality risk and/or decline in reproductive success and mediated by deterioration of functional performance. While this makes ageing intuitively paradoxical - detrimental to individual fitness - evolutionary theory offers answers as to why ageing has evolved. In this review, I first briefly examine the classic evolutionary theories of ageing and their empirical tests, and highlight recent findings that have advanced our understanding of the evolution of ageing (condition-dependent survival, positive pleiotropy). I then provide an overview of recent theoretical extensions and modifications that accommodate those new discoveries. I discuss the role of indeterminate (asymptotic) growth for lifetime increases in fecundity and ageing trajectories. I outline alternative views that challenge a universal existence of senescence - namely the lack of a germ-soma distinction and the ability of tissue replacement and retrogression to younger developmental stages in modular organisms. I argue that rejuvenation at the organismal level is plausible, but includes a return to a simple developmental stage. This may exempt a particular genotype from somatic defects but, correspondingly, removes any information acquired during development. A resolution of the question of whether a rejuvenated individual is the same entity is central to the recognition of whether current evolutionary theories of ageing, with their extensions and modifications, can explain the patterns of ageing across the Tree of Life. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Chronology of Desert Margin in Western India using Improved ...

    Indian Academy of Sciences (India)

    27

    Chronology of Desert Margin in Western India using Improved. Luminescence Dating Protocols. Naveen Chauhan*1, P. Morthekai1,2,#. 1 AMOPH, Physical Research Laboratory, Navrangpura, Ahmedabad - 380 009, India. 2 Institute of Seismological Research, Raisan, Gandhinagar - 382 009, India. # Present Address: ...

  10. Reservoir effects in a Stone Age fjord on Lolland, Denmark

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2018-01-01

    On the island of Lolland, southeast Denmark, an area of almost 300 ha is currently under archaeological investigation prior to the planned construction of a tunnel between Denmark and Germany under the Femern belt. The area investigated in the context of the “Femern project” includes a former fjo...... for building chronologies and for reconstructing the environment of the Stone Age fjord. Finally, I will discuss the pitfalls and uncertainties associated with radiocarbon dates for sea level reconstruction....

  11. 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.

  12. Chronologic Trends in Studies on Fluoride Mechanisms of Action.

    Science.gov (United States)

    Oh, H J; Oh, H W; Lee, D W; Kim, C H; Ahn, J Y; Kim, Y; Shin, H B; Kim, C Y; Park, S H; Jeon, J G

    2017-11-01

    Fluoride has been widely used for the prevention of dental caries since the mid-20th century. The aim of this study was to investigate the chronologic trends in studies on fluoride mechanisms of action against dental caries during the years 1950 to 2015. To this aim, queries such as "fluoride," "fluoride and demineralization," "fluoride and remineralization," "fluoride and (plaque or biofilms)," and "fluoride and (bacteria or microbials)" were submitted to PubMed to collect research article information, including titles, abstracts, publication dates, author affiliations, and publication journals. The article information that PubMed produced was then collected by an automatic web crawler and examined through informetrics and linguistic analyses. We found that the number of articles concerned with fluoride mechanisms of action against dental caries was 6,903 and gradually increased over time during the years 1950 to 2015. They were published by 1,136 journals-most notably, Caries Research and Journal of Dental Research. Of the articles published, those related to bacteria/microbials had a higher percentage (44%) than those dealing with plaque/biofilms, demineralization, and remineralization. With regard to the geographic distribution of authors, Europe and North America accounted for 65% of the articles during the years 1987 to 2015, although the number of authors in Asia sharply increased in recent years. Among the fluoride compounds, NaF was mentioned more frequently than SnF 2 , Na 2 PO 3 F, amine fluoride, and acidulated phosphate fluoride during the years 1986 to 2015. Water fluoridation received the most attention among the various fluoride application methods (toothpastes, mouthwashes, fluoride varnishes, and fluoride gels) during the same period. These results, obtained from employing informetrics and linguistic analyses, suggest that in studies on fluoride mechanisms of action, 1) the unbalanced geographic distribution of articles and 2) the heavy

  13. The History of Therapeutic Aerosols: A Chronological Review

    Science.gov (United States)

    Thiel, Charles G.

    2017-01-01

    Abstract In 1956, Riker Laboratories, Inc., (now 3 M Drug Delivery Systems) introduced the first pressurized metered dose inhaler (MDI). In many respects, the introduction of the MDI marked the beginning of the modern pharmaceutical aerosol industry. The MDI was the first truly portable and convenient inhaler that effectively delivered drug to the lung and quickly gained widespread acceptance. Since 1956, the pharmaceutical aerosol industry has experienced dramatic growth. The signing of the Montreal Protocol in 1987 led to a surge in innovation that resulted in the diversification of inhaler technologies with significantly enhanced delivery efficiency, including modern MDIs, dry powder inhalers, and nebulizer systems. The innovative inhalers and drugs discovered by the pharmaceutical aerosol industry, particularly since 1956, have improved the quality of life of literally hundreds of millions of people. Yet, the delivery of therapeutic aerosols has a surprisingly rich history dating back more than 3500 years to ancient Egypt. The delivery of atropine and related compounds has been a crucial inhalation therapy throughout this period and the delivery of associated structural analogs remains an important therapy today. Over the centuries, discoveries from many cultures have advanced the delivery of therapeutic aerosols. For thousands of years, therapeutic aerosols were prepared by the patient or a physician with direct oversight of the patient using custom-made delivery systems. However, starting with the Industrial Revolution, advancements in manufacturing resulted in the bulk production of therapeutic aerosol delivery systems produced by people completely disconnected from contact with the patient. This trend continued and accelerated in the 20th century with the mass commercialization of modern pharmaceutical inhaler products. In this article, we will provide a summary of therapeutic aerosol delivery from ancient times to the present along with a look to the

  14. Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North America.

    Science.gov (United States)

    Gennaretti, Fabio; Arseneault, Dominique; Nicault, Antoine; Perreault, Luc; Bégin, Yves

    2014-07-15

    Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910-1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing.

  15. Toward a late Holocene glacial chronology for the eastern Nyainqêntanglha Range, southeastern Tibet

    Science.gov (United States)

    Loibl, David; Hochreuther, Philipp; Schulte, Philipp; Hülle, Daniela; Zhu, Haifeng; Bräuning, Achim; Lehmkuhl, Frank

    2015-01-01

    Monsoonal-affected temperate glaciers in the eastern Nyainqêntanglha Range, southeastern Tibet, are highly sensitive to climate change. Knowledge about their late Holocene dynamics is still, however, widely lacking. The few studies on glacial chronology which are available for this region tend to mainly focus on dating results without sufficiently considering the geomorphological setting, often leading to misinterpretations in this complex high mountain environment. In this study, two selected glacier forelands are investigated using a multi-proxy approach encompassing detailed geomorphological mapping, dendrochronology, sedimentology, and optically stimulated luminescence as well as radiocarbon dating. The starting point was the creation of a consistent morphosequence which was validated by remote sensing of further glacier forelands from the wider region. Similarities and differences between the investigated settings were analyzed in detail to identify the relevant morphological and topoclimatic forcing mechanisms. We found evidence of climatic events affecting the whole region during the Little Ice Age, resulting in similar configurations and numbers of moraines. The geomorphological settings of the glacier forelands are, however, remarkably different, making investigations of the landform and sediment configuration an indispensable condition for their interpretation. Subsequently, constraints from different methods of relative and numerical dating were evaluated critically and included into a conceptual chronosequence if applicable. Our results suggest that the late Holocene maximum glacier advance comprised several successive advances from mid-17th to mid-18th century. None of our observations supports an earlier Neoglacial advance reaching further than the LIA maximum. After the LIA maximum, continued retreat that was only interrupted by short phases of stability followed, as evidenced by 2-3 recessional moraines in the investigated settings.

  16. Magma sources during Gondwana breakup: chemistry and chronology of Cretaceous magmatism in Westland, New Zealand

    Science.gov (United States)

    van der Meer, Quinten H. A.; Waight, Tod E.; Scott, James M.

    2013-04-01

    Cretaceous-Paleogene rifting of the Eastern Gondwana margin thinned the continental crust of Zealandia and culminated in the opening of the Tasman Sea between Australia and New Zealand and the Southern Ocean, separating both from Antarctica. The Western Province of New Zealand consists of a succession of metasedimentary rocks intruded by Palaeozoic and Mesozoic granitoids that formed in an active margin setting through the Phanerozoic. Upon cessation of subduction, the earliest stages of extension (~110-100 Ma) were expressed in the formation of metamorphic core complexes, followed by emplacement of granitoid plutons, the deposition of terrestrial Pororari Group sediments in extensional half-grabens across on- and offshore Westland, and the intrusion of mafic dikes from ~90 Ma. These dikes are concentrated in the swarms of the Paparoa and Hohonu Ranges and were intruded prior to and simultaneous with volumetrically minor A-type plutonism at 82 Ma. The emplacement of mafic dikes and A-type plutonism at ~82 Ma is significant as it coincides with the age of the oldest seafloor in the Tasman Sea, therefore it represents magmatism coincident with the initiation of seafloor spreading which continued until ~53 Ma. New 40Ar-39Ar ages indicate that the intrusion of mafic dikes in basement lithologies both preceded and continued after the initial opening of the Tasman Sea, including an additional population of ages at ~70 Ma. This indicates either a prolonged period of extension-related magmatism that continued >10 Ma after initial breakup, or two discrete episodes of magmatism during Tasman Sea spreading. Volumetrically minor Cenozoic within-plate magmatism continued sporadically throughout the South Island and bears a characteristic HIMU (high time integrated U/Pb) signature. A detailed geochemistry and chronological study of Cretaceous mafic and felsic magmatism is currently in progress and aims to better understand the transition of magma sources from a long lived active

  17. Phoenician ceramic tableware between East and West: some remarks on open forms and on their absolute chronology

    Directory of Open Access Journals (Sweden)

    Sara Giardino

    2017-09-01

    Full Text Available In this paper a typological and chronological framework of the evolution of open forms of the Phoenician table pottery is outlined, starting from the Iron Age documentation of the Syro-Palestinian coast (11th-6th centuries BC up to the colonial elaborations of the Iberian Peninsula (9th-6th centuries BC. The definition of the chrono-typological horizons identified in both areas is combined with an analysis of the issues affecting the absolute chronology of the Iron Age in the Mediterranean basin. The focus is on the early stages of the Phoenician presence in West, given the increasing number of archaic evidences emerged notably at Huelva and Cádiz. The analysis is also carried out through the comparison with other archaic contexts recently come to light, for example, at Utica and Carthage.

  18. The effects of infographics and several quantitative versus qualitative formats for cardiovascular disease risk, including heart age, on people's risk understanding.

    NARCIS (Netherlands)

    Damman, Olga C; Vonk, Suzanne I; Van den Haak, Maaike J; van Hooijdonk, Charlotte M J; Timmermans, Danielle R M

    2018-01-01

    To study how comprehension of cardiovascular disease (CVD) risk is influenced by: (1) infographics about qualitative risk information, with/without risk numbers; (2) which qualitative risk dimension is emphasized; (3) heart age vs. traditional risk format.

  19. Evolução da aptidão física e capacidade funcional de mulheres ativas acima de 50 anos de idade de acordo com a idade cronológica, na cidade de Santos Evolution of physical fitness and functional capacity in active elderly women over 50 years of age according to chronological age in Santos city

    Directory of Open Access Journals (Sweden)

    José Carlos Lopes Penha

    2012-01-01

    Full Text Available O objetivo deste estudo foi comparar a evolução da aptidão física, capacidade funcional e densidade mineral óssea de mulheres fisicamente ativas durante um ano. Métodos: A amostra consistiu de 78 mulheres de 50 a 79 anos de idade (c: 62,4 ± 7,1 anos, participantes de um programa de exercícios aeróbicos, duas vezes por semana, 50 minutos por sessão durante 3,4 anos e divididas em três grupos: A: 5059 (n: 38; B: 6069 (n: 28; C: 7079 (n:12. Os resultados foram comparados usando ANOVA Two Way com "post-hoc" Bonferroni e delta percentual (*pThe scope of this study was to compare the evolution of physical fitness, functional capacity and bone mineral density in active elderly women over a one-year period. The sample consisted of 78 women from 50 to 79 years of age (c:62.4 ± 7.1 participating in an aerobic program, twice a week, 50 minutes per session during 3.4 years and divided into three age groups: A: 50-59 (n:38; B: 60-69 (n:28; C: 70-79 (n:12. Results were compared using Two Way ANOVA, "post-hoc" Bonferroni and delta (D% variations (*p<.o1. The velocity of rising from a chair and gait speed revealed a significant difference in the three groups ranging from -14.3% to -45.5%; there was a significant improvement in A and B groups in walking speed (-12.1% to -13.9%, and also in maximum gait speed (-15.4% to -18.5%, elbow flexion in all the groups (18.9% to 24.1%, vertical jump (22.5% to 43.9% in groups B and C, and rising from a chair in 30 seconds (25.2% to 30.8% in groups A and B, the flexibility test showed an increase in group A (16.2% to 33.3% and stationary walking in the three groups of (16,4% 30.0% and bone mineral density (BMD presented a significant increase (3.1% to 10.2%. The results indicate the salutary effect of regular physical activity.

  20. The range of peripapillary retinal nerve fibre layer and optic disc parameters in children aged up to but not including 18 years of age, as measured by optical coherence tomography: protocol for a systematic review.

    Science.gov (United States)

    Creavin, Alexandra L; Williams, Cathy; Tilling, Kate; Timpson, Nicholas; Higgins, Julian P T

    2016-04-30

    The parameters of the optic disc and peripapillary retinal nerve fibre layer (pRNFL) in children may vary with disease processes that contribute to visual impairment and blindness and so could be useful as an objective measure in at-risk children. There is no standardised reference for the normal parameters of the optic disc and pRNFL in children; however, there are a large number of small individual studies that have been undertaken to look at these measures. A systematic review of current literature on the range of pRNFL and optic disc parameters in children aged less than 18 years will be performed. Studies will be considered for review if they report numerical data on optic disc and pRNFL parameters, measured using optical coherence tomography. Outcome measures will include mean pRNFL thickness and cup-disc ratio. The bibliographic databases Medline, CINAHL, EMBASE, Scopus and Web of Science will be systematically searched from 1991. Screening of search results will be conducted by two authors working independently, as will extraction of primary and secondary outcome data. Ten per cent of all other data extraction will be checked by a second author. Results will be compiled and presented in evidence tables. Where possible and appropriate, study-specific estimates will be combined to obtain an overall summary estimate of pRNFL thickness and cup-disc ratio across studies and results will be presented by age of population. Subgroup analyses will be undertaken for children of different ethnicities. This review aims to provide an overview of the parameters of the optic disc and pRNFL in children of different ages in order to identify gaps in knowledge and to improve understanding of what might be considered within/outside the range of normality. The findings will be presented in peer-reviewed journals and will be presented at conferences. PROSPERO CRD42016033068.

  1. Studies of the chronological course of third molars eruption in a northern Chinese population.

    Science.gov (United States)

    Guo, Yu-cheng; Yan, Chun-xia; Lin, Xing-wei; Zhou, Hong; Pan, Feng; Wei, Lai; Tang, Zheng; Liang, Feng; Chen, Teng

    2014-09-01

    Dental age estimation is of great importance for individual identification in forensic medicine and many other fields of study. Among them, tooth eruption is a parameter developmental morphology that can be determined by clinical examinations or by dental X-rays. The purpose of present research is to study the chronological course of third molars eruption in a Chinese population and compare that with other ethnic population for age estimation. A total of 1135 conventional orthopantomograms from 506 male and 629 female northern Chinese subjects aged between 11 and 26 years were analyzed. The eruption status of the third molars was assessed using the developmental stages described by Olze et al. Results showed that the third molars 18, 28, 38 and 48 in the stage A showed significant younger average age in males than in females. The Olze's stage A could be used as a reference stage to determine whether a male or female northern Chinese is likely to be equal or above age 16, with 99.6-100% and 97.4-98.1% of correct predictions, respectively. The stage D was found to be a useful marker for diagnosing age under 16 years, with 98.9-100% and 100% of correct predictions in males and females, respectively. There were some significant differences of the chronological course of the third molars eruption in different ethnic groups, which indicated that population-specific standards could enhance the accuracy of forensic age estimation based on third molar eruption. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. The early chronology of the moon: evidence for the early collisional history of the solar system

    International Nuclear Information System (INIS)

    Turner, G.

    1977-01-01

    The results of age determinations which have provided information on two aspects of the early evolution to the lunar crust in the period prior to the extrusion of the mare basalts, the magnetic activity which led to the chemical differentiation of the outer regions of the Moon and the bombardment of the Moon by large objects in the period immediately following its formation, are considered. 40 Ar- 39 Ar ages have been largely reset by the final stages of the bombardment and therefore most of the information obtained from argon measurements pertains to the chronology of the bombardment. Information on the magmatic activity is obtained from Rb-Sr, U, Th-Pb and Sm-Nd studies. The clustering of most lunar highland ages in the interval 3.9 to 4.0 Ga is impressive and interpretation of the results is discussed. (U.K.)

  3. Dental computed tomographic imaging as age estimation: morphological analysis of the third molar of a group of Turkish population.

    Science.gov (United States)

    Cantekin, Kenan; Sekerci, Ahmet Ercan; Buyuk, Suleyman Kutalmis

    2013-12-01

    Computed tomography (CT) is capable of providing accurate and measurable 3-dimensional images of the third molar. The aims of this study were to analyze the development of the mandibular third molar and its relation to chronological age and to create new reference data for a group of Turkish participants aged 9 to 25 years on the basis of cone-beam CT images. All data were obtained from the patients' records including medical, social, and dental anamnesis and cone-beam CT images of 752 patients. Linear regression analysis was performed to obtain regression formulas for dental age calculation with chronological age and to determine the coefficient of determination (r) for each sex. Statistical analysis showed a strong correlation between age and third-molar development for the males (r2 = 0.80) and the females (r2 = 0.78). Computed tomographic images are clinically useful for accurate and reliable estimation of dental ages of children and youth.

  4. Constraints on the Pleistocene chronology of sediments from the Lomonosov Ridge

    Science.gov (United States)

    O'Regan, M.; King, J.; Backman, J.; Jakobsson, M.; Palike, H.; Moran, K.; Heil, C.; Sakamoto, T.; Cronin, T. M.; Jordan, R.W.

    2008-01-01

    Despite its importance in the global climate system, age-calibrated marine geologic records reflecting the evolultion of glacial cycles through the Pleistocene are largely absent from the central Arctic Ocean. This is especially true for sediments older than 200 ka. Three sites cored during the Integrated Ocean Drilling Program's Expedition 302, the Arctic Coring Expedition (ACEX), provide a 27 m continuous sedimentary section from the Lomonosov Ridge in the central Arctic Ocean. Two key biostratigraphic datums and constraints from the magnetic inclination data are used to anchor the chronology of these sediments back to the base of the Cobb Mountain subchron (1215 ka). Beyond 1215 ka, two best fitting geomagnetic models are used to investigate the nature of cyclostratigraphic change. Within this chronology we show that bulk and mineral magnetic properties of the sediments vary on predicted Milankovitch frequencies. These cyclic variations record "glacial" and "interglacial" modes of sediment deposition on the Lomonosov Ridge as evident in studies of ice-rafted debris and stable isotopic and faunal assemblages for the last two glacial cycles and were used to tune the age model. Potential errors, which largely arise from uncertainties in the nature of downhole paleomagnetic variability, and the choice of a tuning target are handled by defining an error envelope that is based on the best fitting cyclostratigraphic and geomagnetic solutions. Copyright 2008 by the American Geophysical Union.

  5. Autophagy and leucine promote chronological longevity and respiration proficiency during calorie restriction in yeast.

    Science.gov (United States)

    Aris, John P; Alvers, Ashley L; Ferraiuolo, Roy A; Fishwick, Laura K; Hanvivatpong, Amanda; Hu, Doreen; Kirlew, Christine; Leonard, Michael T; Losin, Kyle J; Marraffini, Michelle; Seo, Arnold Y; Swanberg, Veronica; Westcott, Jennifer L; Wood, Michael S; Leeuwenburgh, Christiaan; Dunn, William A

    2013-10-01

    We have previously shown that autophagy is required for chronological longevity in the budding yeast Saccharomyces cerevisiae. Here we examine the requirements for autophagy during extension of chronological life span (CLS) by calorie restriction (CR). We find that autophagy is upregulated by two CR interventions that extend CLS: water wash CR and low glucose CR. Autophagy is required for full extension of CLS during water wash CR under all growth conditions tested. In contrast, autophagy was not uniformly required for full extension of CLS during low glucose CR, depending on the atg allele and strain genetic background. Leucine status influenced CLS during CR. Eliminating the leucine requirement in yeast strains or adding supplemental leucine to growth media extended CLS during CR. In addition, we observed that both water wash and low glucose CR promote mitochondrial respiration proficiency during aging of autophagy-deficient yeast. In general, the extension of CLS by water wash or low glucose CR was inversely related to respiration deficiency in autophagy-deficient cells. Also, autophagy is required for full extension of CLS under non-CR conditions in buffered media, suggesting that extension of CLS during CR is not solely due to reduced medium acidity. Thus, our findings show that autophagy is: (1) induced by CR, (2) required for full extension of CLS by CR in most cases (depending on atg allele, strain, and leucine availability) and, (3) promotes mitochondrial respiration proficiency during aging under CR conditions. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology.

    Directory of Open Access Journals (Sweden)

    Sturt W Manning

    Full Text Available 500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C measurements to achieve tightly resolved absolute (calendar chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681-1673 BCE (68.2% highest posterior density

  7. Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology.

    Science.gov (United States)

    Manning, Sturt W; Griggs, Carol B; Lorentzen, Brita; Barjamovic, Gojko; Ramsey, Christopher Bronk; Kromer, Bernd; Wild, Eva Maria

    2016-01-01

    500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur) and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C) measurements to achieve tightly resolved absolute (calendar) chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681-1673 BCE (68.2% highest posterior density range), ~20

  8. Notes on Glasinac: The chronology of princely graves

    Directory of Open Access Journals (Sweden)

    Vasić Rastko

    2009-01-01

    Full Text Available Princely graves of the Iron Age represent a particular phenomenon in archaeology, which is constantly the subject of interest. They are usually dated to the end of the 6th and the beginning of the 5th century. The author discusses the chronology of princely graves in the Central Balkans and analyses their appearance in each part of this territory: on the Glasinac plateau, in Serbia, Kosovo and Metohija, Montenegro, North Albania and Nordwest Bulgaria. He concludes that they date from the middle of the 7th to the middle of the 4th century, depending on the cultural and socio-economic situation in the respective area. In the middle of the 7th century princely graves in the true sense of the word were known only on the Glasinac plateau, in the Ilijak necropolis. At the end of the 7th and in the beginning of the 6th century they still appear on Glasinac, though in greater number and in various parts of the plateau. In northwest Bulgaria a grave dating to the second half of the 7th century was found, which would, according to grave goods, correspond to the Glasinac princely graves. On the other hand, there are no princely graves in Serbia and north Albania from that time but some outstanding warrior graves are known, belonging possibly to the chiefs of smaller warlike bands, whose power was limited. Princely graves from Arareva gromila on Glasinac, Pilatovići by Požega and Lisijevo Polje by Berane date to the beginning of the second half of the 6th century, and according to their characteristics represent princes, whose power and wealth were considerable and known to the neighbours. Culmination of the rise of the princes in this region was demonstrated by the graves from Novi Pazar, Atenica, and Pećka banja, which date to the end of the 6th and the first quarter of the 5th century. Some decades later there are several rich graves, e.g. the recently discovered grave from Velika Krsna, which could belong to a prince, but can not be compared with the

  9. Aging

    International Nuclear Information System (INIS)

    Sasaki, Hideo; Kodama, Kazunori; Yamada, Michiko

    1991-01-01

    The hypothesis that exposure to ionizing radiation accelerates the aging process has been actively investigated at ABCC-RERF since 1958, when longitudinal cohort studies of the Adult Health Study (AHS) and the Life Span Study (LSS) were initiated. In their 1975 overall review of aging studies related to the atomic bomb (A-bomb) survivors, Finch and Beebe concluded that while most studies had shown no correlation between aging and radiation exposure, they had not involved the large numbers of subjects required to provide strong evidence for or against the hypothesis. Extending LSS mortality data up to 1978 did not alter the earlier conclusion that any observed life-shortening was associated primarily with cancer induction rather than with any nonspecific cause. The results of aging studies conducted during the intervening 15 years using data from the same populations are reviewed in the present paper. Using clinical, epidemiological, and laboratory techniques, a broad spectrum of aging parameters have been studied, such as postmortem morphological changes, tests of functional capacity, physical tests and measurements, laboratory tests, tissue changes, and morbidity. With respect to the aging process, the overall results have not been consistent and are generally thought to show no relation to radiation exposure. Although some preliminary results suggest a possible radiation-induced increase in atherosclerotic diseases and acceleration of aging in the T-cell-related immune system, further study is necessary to confirm these findings. In the future, applying the latest gerontological study techniques to data collected from subjects exposed 45 years ago to A-bomb radiation at relatively young ages will present a new body of data relevant to the study of late radiation effects. (author) 103 refs

  10. The effects of infographics and several quantitative versus qualitative formats for cardiovascular disease risk, including heart age, on people's risk understanding.

    Science.gov (United States)

    Damman, Olga C; Vonk, Suzanne I; van den Haak, Maaike J; van Hooijdonk, Charlotte M J; Timmermans, Danielle R M

    2018-03-11

    To study how comprehension of cardiovascular disease (CVD) risk is influenced by: (1) infographics about qualitative risk information, with/without risk numbers; (2) which qualitative risk dimension is emphasized; (3) heart age vs. traditional risk format. For aim 1, a 2 (infographics versus text) x 2 (risk number versus no risk number) between-subjects design was used. For aim 2, three pieces of information were tested within-subjects. Aim 3 used a simple comparison group. Participants (45-65 yrs old) were recruited through an online access panel; low educated people were oversampled. They received hypothetical risk information (20%/61yrs). Primary outcomes: recall, risk appraisals, subjective/objective risk comprehension. behavioral intentions, information evaluations. Infographics of qualitative risk dimensions negatively affected recall, subjective risk comprehension and information evaluations. No effect of type of risk dimension was found on risk perception. Heart age influenced recall, comprehension, evaluations and affective risk appraisals. Infographics of hypothetical CVD risk information had detrimental effects on measures related to risk perception/comprehension, but effects were mainly seen in undereducated participants. Heart age influenced perceptions/comprehension of hypothetical risk in a way that seemed to support understanding. Heart age seems a fruitful risk communication approach in disease risk calculators. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Dental Age Estimation (DAE): Data management for tooth development stages including the third molar. Appropriate censoring of Stage H, the final stage of tooth development.

    Science.gov (United States)

    Roberts, Graham J; McDonald, Fraser; Andiappan, Manoharan; Lucas, Victoria S

    2015-11-01

    The final stage of dental development of third molars is usually helpful to indicate whether or not a subject is aged over 18 years. A complexity is that the final stage of development is unlimited in its upper border. Investigators usually select an inappropriate upper age limit or censor point for this tooth development stage. The literature was searched for appropriate data sets for dental age estimation and those that provided the count (n), the mean (x¯), and the standard deviation (sd) for each of the tooth development stages. The Demirjian G and Demirjian H were used for this study. Upper and lower limits of the Stage G and Stage H data were calculated limiting the data to plus or minus three standard deviations from the mean. The upper border of Stage H was limited by appropriate censoring at the maximum value for Stage G. The maximum age at attainment from published data, for Stage H, ranged from 22.60 years to 34.50 years. These data were explored to demonstrate how censoring provides an estimate for the correct maximum age for the final stage of Stage H as 21.64 years for UK Caucasians. This study shows that confining the data array of individual tooth developments stages to ± 3sd provides a reliable and logical way of censoring the data for tooth development stages with a Normal distribution of data. For Stage H this is inappropriate as it is unbounded in its upper limit. The use of a censored data array for Stage H using Percentile values is appropriate. This increases the reliability of using third molar Stage H alone to determine whether or not an individual is over 18 years old. For Stage H, individual ancestral groups should be censored using the same technique. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  12. TEACH Kitchen: A Chronological Review of Accomplishments

    Science.gov (United States)

    Chae, Jung Hee; Ansa, Benjamin E.; Smith, Selina A.

    2017-01-01

    Background The Eating and Cooking Healthy (TEACH) Kitchen was founded at the Medical College of Georgia in 2015 as a nutrition-based intervention to combat the high prevalence of obesity and obesity-related chronic diseases in the area of Augusta, Georgia. Despite the importance of diet in the management of chronic diseases, inadequate nutrition education among patients and healthcare providers presents a barrier. The purpose of TEACH Kitchen is to address this gap. Methods TEACH Kitchen is as a student-led initiative that promotes healthy cooking among medical students and patients with chronic diseases. Healthy nutrition and cooking classes are held during the academic year. Participants spend four weeks on each of four modules: obesity, hypertension, hyperlipidemia, and diabetes mellitus. Data collection, which began in January 2017, is currently on going. TEACH Kitchen has collaborated with Augusta University, Sodexo, and Kohl’s. Results Currently, TEACH Kitchen has enrolled 14 patients and 6 children. Anticipated results include measurements of pre-and post-intervention changes in knowledge, attitudes, beliefs, and competence in nutrition, as well as differences in clinical indicators, including body mass index, blood pressure, lipid profile, and HbA1c. Conclusions TEACH Kitchen is the first medical school-based nutrition/cooking education initiative in Augusta, Georgia. It provides patients and medical students with hands-on healthy nutrition/cooking experience with the goal of decreasing the prevalence and improving the outcome of obesity-related diseases. PMID:28890945

  13. SEALEX — Internal reef chronology and virtual drill logs from a spreadsheet-based reef growth model

    Science.gov (United States)

    Koelling, Martin; Webster, Jody Michael; Camoin, Gilbert; Iryu, Yasufumi; Bard, Edouard; Seard, Claire

    2009-03-01

    A reef growth model has been developed using an Excel spreadsheet. The 1D forward model is driven by a user definable sea-level curve. Other adjustable model parameters include maximum coral growth rate, coral growth rate depth dependence and light attenuation, subaerial erosion and subsidence. A time lag for the establishment of significant reef accretion may also be set. During the model run, both, the external shape and the internal chronologic structure of the growing reef as well as the paleo-water-depths are continuously displayed and recorded. We tested the model on fossil reef systems growing in a range of different tectonic settings such as both on slowly subsiding islands like Tahiti (subsidence rates of 0.25 m ka - 1 ) and rapidly subsiding islands like Hawaii (subsidence rate of 2.5 mka - 1 ) as well as rapidly uplifting coastal settings like Huon Peninsula (uplift rates of 0.5 to 4 m ka - 1 ) and more slowly uplifting settings like Haiti (uplift rates of 0.55 mka - 1 ). The model runs show the sensitivity of the resulting overall morphology and internal age structure to different model parameters. Additionally the water depth at the time of deposition is recorded. This allows the constructions of virtual borehole logs with the coral age profiles and the paleo water depth at the time of growth both displayed and recorded. Because the model is implemented as a macro in a popular spreadsheet program, it may be easily adapted or extended to model the growth of different reef and carbonate platform settings. Single model runs take a few minutes on a standard (2 GHz CoreDuo) desktop computer under Windows XP. The model may be used to investigate the effects of different boundary conditions such as maximum reef growth, erosion rates, subsidence or uplift on both, the general morphology of the reefs, and the internal chronologic structure. These results can then be compared to observed data allowing different hypothesis concerning reefs development to be

  14. Tritium Measurements in Slovenia - Chronology Till 2004

    International Nuclear Information System (INIS)

    Logar, Jasmina Kozar; Vaupotic, Janja; Kobal, Ivan

    2005-01-01

    Almost all the analyses of tritium in Slovenia have been performed by the tritium laboratory at the Jozef Stefan Institute. Nearly 90 % of its measurements have been covered by two national programs, both approved by the Slovenian Nuclear Safety Administration: the radioactive monitoring program in the environs of Krsko Nuclear Power Plant (KNPP) and the program of global radioactive contamination monitoring in the environment. These programs include samples of groundwaters, surface waters, precipitation and drinking waters, as well as liquid and gaseous effluents from KNPP. Tritium was determined in some research projects and in hydrological studies of thermal waters, groundwater and coalmine waters. Tritium in the Karst region was mapped as well as the springs of entire territory of Slovenia. Around 5500 samples have been analyzed up to 2004

  15. An Alluvial Surface Chronology Based on Cosmogenic 36Cl Dating, Ajo Mountains (Organ Pipe Cactus National Monument), Southern Arizona

    Science.gov (United States)

    Liu, Beiling; Phillips, Fred M.; Pohl, Molly M.; Sharma, Pankaj

    1996-01-01

    A chronology of alluvial surfaces on piedmont slopes below the western Ajo Mountains, southern Arizona, has been obtained using cosmogenic 36Cl accumulation and AMS radiocarbon dating. The apparent 36Cl ages of individual boulders range from 520,000 to 13,000 yr, and the 14C ages of organic material in the two young terraces are 2750-2350 and 17,800 cal yr B.P. The sequence of 36Cl ages is consistent with the apparent stratigraphic order, but groupings of similar ages for different surfaces appear to result from repeated reworking of older surfaces associated with the deposition of younger ones. The youngest surface gave a distribution of 36Cl ages about 30,000 yr older than the 14C and soil ages; however, this distribution had 36Cl ages that overlapped with 36Cl ages from active channels and hillslopes. We attribute the older-than-expected exposure ages of sampled boulders to inheritance of 36Cl while residing near the surface during very slow erosion on the mountain front. Our results show that although cosmogenic nuclide accumulation can help establish chronologies for surfaces in piedmont settings, care must be used in evaluating the effects of complex exposure histories.

  16. Insight into the Fulnek Church and Parish Medieval Building Chronology

    Directory of Open Access Journals (Sweden)

    Augustinková Lucie

    2017-06-01

    Full Text Available The church of the Holy Trinity and parish in Fulnek was for nearly four centuries an Augustinian canonry and collegiate church (1293-1389. The medieval church and parish building chronology, however, have not been thus far established. From research between 2015 and 2016 we have been able to identify medieval portions of the buildings, clarify the site medieval construction phases and date the parish buildings (formerly the canonry from dendrochronological analysis of embedded wooden scaffolding.

  17. The Creation of the world and the birth of chronology

    Science.gov (United States)

    Richet, Pascal

    2017-09-01

    The eternity of the world and, correlatively, the cyclical nature of time were agreed upon by all Greek philosophical schools except the Platonists. As for matter, all of them posited that it was eternal so that the idea that something could be made from nothing was considered as pure absurdity. With the advent of Christianity, however, a matter coeternal with God raised fundamental theological difficulties. Toward the end of the second century, apologists such as Tatian the Assyrian, Theophilus of Antioch, Irenaeus of Lyons or Tertullian thus emphasized God's absolute freedom and power by claiming that Creation had been made from nothing. Along with the Passion of Christ and the Last Judgment, the initial moment defined by the Creation then conferred to time an irreversible, linear orientation and to history both a new sense and an obsessing concern for chronology. Unambiguously, the Creation became the reference point for the world's history. From Scripture analyses, one determined that it took place about 5500 years earlier within a framework where the History of man and that of the earth were not distinct. Having designed a consistent, universal time scale from chronological data recorded for all ancient peoples, Eusebius of Caesarea could thus attribute to the Great Flood the fossils found on the top of Mount Lebanon. The short Mosaic chronologies were eventually rejected during the 18th century, but Eusebius' chronological procedure was unknowingly transposed when a relative geological timescale was then set up from the fossil record. The close association of Creation with Christian dogma in turn induced some circles to reject the second law of thermodynamics at the end of the 19th century and, a few decades later, the thesis of an expanding universe. In both cases, the reason was that continuously increasing entropy would imply some low-entropy initial state akin to a Creation.

  18. Dental age assessment: Which is the most applicable method?

    Science.gov (United States)

    Lopes, Luciana Jácome; Nascimento, Helena Aguiar Ribeiro; Lima, Giovanna Panebianchi; Santos, Luís Antônio Nogueira Dos; Queluz, Dagmar de Paula; Freitas, Deborah Queiroz

    2018-03-01

    To evaluate which method is the most applicable for estimating estimate dental age in Brazilian children, Nolla or Demirjian. For this purpose, both methods were reviewed and the differences between them brought to light. A total of 403 healthy children between the ages of 7 and 13 years with satisfactory panoramic radiographs, similar socio-economic background and ethnic origin were included. Panoramic radiographs were examined by the Nolla and Demirjian methods. Dental age was calculated for both methods, and the differences between the dental age and the chronological age were compared with analysis of variance with post hoc Dunnett. The Nolla method showed no significant difference in relation to chronological age in the majority of age groups for boys and girls, except for 12-year-old boys (over-estimation of 1.00) and between 11- and 12-year-old girls (over-estimation of 0.51 and 0.59, respectively). An over-estimation of the dental age was observed by using the Demirjian method (for boys 0.89-1.84 and for girls 0.69-1.97) for all age groups. The Nolla method is suitable for Brazilian children when it comes to age estimate with care to growth spurt beginning (around 11 and 12 years). However, the Dermijian method should not be used, because it over-estimated the age in both sexes. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Bayesian modeling and chronological precision for Polynesian settlement of Tonga.

    Directory of Open Access Journals (Sweden)

    David Burley

    Full Text Available First settlement of Polynesia, and population expansion throughout the ancestral Polynesian homeland are foundation events for global history. A precise chronology is paramount to informed archaeological interpretation of these events and their consequences. Recently applied chronometric hygiene protocols excluding radiocarbon dates on wood charcoal without species identification all but eliminates this chronology as it has been built for the Kingdom of Tonga, the initial islands to be settled in Polynesia. In this paper we re-examine and redevelop this chronology through application of Bayesian models to the questioned suite of radiocarbon dates, but also incorporating short-lived wood charcoal dates from archived samples and high precision U/Th dates on coral artifacts. These models provide generation level precision allowing us to track population migration from first Lapita occupation on the island of Tongatapu through Tonga's central and northern island groups. They further illustrate an exceptionally short duration for the initial colonizing Lapita phase and a somewhat abrupt transition to ancestral Polynesian society as it is currently defined.

  20. Merging tree ring chronologies and climate system model simulated temperature by optimal interpolation algorithm in North America

    Science.gov (United States)

    Chen, Xin; Xing, Pei; Luo, Yong; Zhao, Zongci; Nie, Suping; Huang, Jianbin; Wang, Shaowu; Tian, Qinhua

    2015-04-01

    A new dataset of annual mean surface temperature has been constructed over North America in recent 500 years by performing optimal interpolation (OI) algorithm. Totally, 149 series totally were screened out including 69 tree ring width (MXD) and 80 tree ring width (TRW) chronologies are screened from International Tree Ring Data Bank (ITRDB). The simulated annual mean surface temperature derives from the past1000 experiment results of Community Climate System Model version 4 (CCSM4). Different from existing research that applying data assimilation approach to (General Circulation Models) GCMs simulation, the errors of both the climate model simulation and tree ring reconstruction were considered, with a view to combining the two parts in an optimal way. Variance matching (VM) was employed to calibrate tree ring chronologies on CRUTEM4v, and corresponding errors were estimated through leave-one-out process. Background error covariance matrix was estimated from samples of simulation results in a running 30-year window in a statistical way. Actually, the background error covariance matrix was calculated locally within the scanning range (2000km in this research). Thus, the merging process continued with a time-varying local gain matrix. The merging method (MM) was tested by two kinds of experiments, and the results indicated standard deviation of errors can be reduced by about 0.3 degree centigrade lower than tree ring reconstructions and 0.5 degree centigrade lower than model simulation. During the recent Obvious decadal variability can be identified in MM results including the evident cooling (0.10 degree per decade) in 1940-60s, wherein the model simulation exhibit a weak increasing trend (0.05 degree per decade) instead. MM results revealed a compromised spatial pattern of the linear trend of surface temperature during a typical period (1601-1800 AD) in Little Ice Age, which basically accorded with the phase transitions of the Pacific decadal oscillation (PDO) and

  1. The luminescence dating chronology of a deep core from Bosten Lake (NW China) in arid central Asia reveals lake evolution over the last 220 ka

    DEFF Research Database (Denmark)

    Li, Guoqiang; Duan, Yanwu; Huang, Xiaozhong

    2016-01-01

    The lacustrine deposits of lakes in arid central Asia (ACA) potentially record palaeoclimatic changes on orbital and suborbital time scales, but such changes are still poorly understood due to the lack of reliable chronologies. Bosten Lake, the largest freshwater inland lake in China, is located...... signals are likely to be well bleached at deposition. Bacon age-depth modelling was used to derive a chronology spanning the last c. 220 ka. The chronology, lithology and grain-size proxy record indicate that Bosten Lake formed at least c. 220 ka ago and that lake levels fluctuated frequently thereafter......-level fluctuations in the lakes of ACA may not respond directly to climatic changes and may be affected by a number of complex factors....

  2. Biological Age Predictors

    OpenAIRE

    Jylh?v?, Juulia; Pedersen, Nancy L.; H?gg, Sara

    2017-01-01

    The search for reliable indicators of biological age, rather than chronological age, has been ongoing for over three decades, and until recently, largely without success. Advances in the fields of molecular biology have increased the variety of potential candidate biomarkers that may be considered as biological age predictors. In this review, we summarize current state-of-the-art findings considering six potential types of biological age predictors: epigenetic clocks, telomere length, transcr...

  3. Correlations between Chronological Ages and Dental Ages on a Group of Children with Down Syndrome

    OpenAIRE

    Chelărescu Simina; Bica Cristina

    2017-01-01

    Background: The number of studies on oral complications in children with Down syndrome is substantial, but they are focused rather on the prevalence of dental caries, periodontal disease, and hypodontia. The relationship between Down syndrome and dental eruption has been rarely approached. The causes of delayed eruption in children with Down syndrome are incompletely elucidated due to the incomplete identification of the factors that intervene in the physiological process of dental eruption.

  4. Chronology and ecology of late Pleistocene megafauna in the northern Willamette Valley, Oregon

    Science.gov (United States)

    Gilmour, Daniel M.; Butler, Virginia L.; O'Connor, James E.; Davis, Edward Byrd; Culleton, Brendan J.; Kennett, Douglas J.; Hodgins, Gregory W. L.

    2015-01-01

    Since the mid-19th century, western Oregon's Willamette Valley has been a source of remains from a wide variety of extinct megafauna. Few of these have been previously described or dated, but new chronologic and isotopic analyses in conjunction with updated evaluations of stratigraphic context provide substantial new information on the species present, timing of losses, and paleoenvironmental conditions. Using subfossil material from the northern valley, we use AMS radiocarbon dating, stable isotope (δ13C and δ15N) analyses, and taxonomic dietary specialization and habitat preferences to reconstruct environments and to develop a local chronology of events that we then compare with continental and regional archaeological and paleoenvironmental data. Analysis of twelve bone specimens demonstrates the presence of bison, mammoth, horse, sloth, and mastodon from ~ 15,000–13,000 cal yr BP. The latest ages coincide with changing regional climate corresponding to the onset of the Younger Dryas. It is suggested that cooling conditions led to increased forest cover, and, along with river aggradation, reduced the area of preferred habitat for the larger bodied herbivores, which contributed to the demise of local megafauna. Archaeological evidence for megafauna–human interactions in the Pacific Northwest is scarce, limiting our ability to address the human role in causing extinction.

  5. A chronological framework connecting the early Upper Palaeolithic across the Central Asian piedmont.

    Science.gov (United States)

    Fitzsimmons, Kathryn E; Iovita, Radu; Sprafke, Tobias; Glantz, Michelle; Talamo, Sahra; Horton, Katharine; Beeton, Tyler; Alipova, Saya; Bekseitov, Galymzhan; Ospanov, Yerbolat; Deom, Jean-Marc; Sala, Renato; Taimagambetov, Zhaken

    2017-12-01

    Central Asia has delivered significant paleoanthropological discoveries in the past few years. New genetic data indicate that at least two archaic human species met and interbred with anatomically modern humans as they arrived into northern Central Asia. However, data are limited: known archaeological sites with lithic assemblages generally lack human fossils, and consequently identifying the archaeological signatures of different human groups, and the timing of their occupation, remains elusive. Reliable chronologic data from sites in the region, crucial to our understanding of the timing and duration of interactions between different human species, are rare. Here we present chronologies for two open air Middle to Upper Palaeolithic (UP) sequences from the Tien Shan piedmont in southeast Kazakhstan, Maibulak and Valikhanova, which bridge southern and northern Central Asia. The chronologies, based on both quartz optically stimulated luminescence (OSL) and polymineral post-infrared infrared luminescence (pIR-IRSL) protocols, demonstrate that technological developments at the two sites differ substantially over the ∼47-19 ka time span. Some of the innovations typically associated with the earliest UP in the Altai or other parts of northeast Asia are also present in the Tien Shan piedmont. We caution against making assumptions about the directionality of spread of these technologies until a larger, better defined database of transitional sites in the region is available. Connections between the timing of occupation of regions, living area setting and paleoenvironmental conditions, while providing hypotheses worth exploring, remain inconclusive. We cautiously suggest a trend towards increasing occupation of open air sites across the Central Asian piedmont after ∼40 ka, corresponding to more humid climatic conditions which nevertheless included pulses of dust deposition. Human occupation persisted into the Last Glacial Maximum, despite cooler, and possibly drier

  6. The quest for an absolute chronology in human prehistory: anthropologists, chemists and the fluorine dating method in palaeoanthropology.

    Science.gov (United States)

    Goodrum, Matthew R; Olson, Cora

    2009-03-01

    By the early twentieth century there was a growing need within palaeoanthropology and prehistoric archaeology to find a way of dating fossils and artefacts in order to know the age of specific specimens, but more importantly to establish an absolute chronology for human prehistory. The radiocarbon and potassium-argon dating methods revolutionized palaeoanthropology during the last half of the twentieth century. However, prior to the invention of these methods there were attempts to devise chemical means of dating fossil bone. Collaborations between Emile Rivière and Adolphe Carnot in the 1890s led to the development of the fluorine dating method, but it was not until the 1940s that this method was improved and widely implemented by Kenneth Oakley to resolve a number of problems in palaeoanthropology, including the Piltdown Man controversy. The invention of the fluorine dating method marked a significant advance in the quest for absolute dating in palaeoanthropology, but it also highlights interesting problems and issues relating to the ability of palaeoanthropologists and chemists to bring together different skills and bodies of knowledge in order successfully to develop and apply the fluorine dating method.

  7. The Greenpeace book of the nuclear age

    International Nuclear Information System (INIS)

    May, John

    1989-01-01

    This is a comprehensive popular account of both civil and military nuclear accidents. It documents major reactor accidents in certain categories such as where significant injury of death occurred, where there was considerable radioactivity release offsite or where there was actual or suspected core damage. Military accidents on nuclear submarines or involving nuclear weapons and civil incidents such as those involving radioactive waste are also included. the book is organised chronologically from the 1940s through succeeding decades to the 1980s. A concluding chapter gives Greenpeace's own perspective on the state of the nuclear age. (author)

  8. An Exploratory Analysis of Child Feeding Beliefs and Behaviors Included in Food Blogs Written by Mothers of Preschool-Aged Children.

    Science.gov (United States)

    Doub, Allison E; Small, Meg; Birch, Leann

    2016-02-01

    This study analyzed child feeding beliefs and behaviors, types of recipes, and their associations in blogs focused on child feeding. The authors selected 13 blogs using purposive snowball sampling, from which 158 blog posts were sampled and coded using directed qualitative content analysis. Child feeding beliefs and behaviors and types of recipes were coded using schemes developed from existing literature. Code frequencies were calculated. Chi-square tests for independence examined associations between child feeding and recipe codes. Bonferroni corrections were applied: P feeding beliefs and behaviors were coded in 78% and 49% of posts, respectively. Beliefs about children's food preferences (48% of posts) and involving children in food preparation (27% of posts) were the most frequent codes. Recipes were included in 66% of posts. Most recipes were for mixed dishes (32% of recipes), followed by sweets and desserts (19% of recipes). Vegetable recipes were more likely in posts that included behavior encouraging balance and variety (χ2 [1, n = 104] = 18.54; P feeding practices. Future research should explore how mothers use blogs to learn about child feeding. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  9. 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.

  10. Towards new mathematical tools for obtaining chronologies in discontinuous archives

    Science.gov (United States)

    Donner, Reik V.

    2014-05-01

    In the last years, a variety of new mathematical approaches has been developed for obtaining reliable chronologies of geological and geomorphological archives based on a limited set of dating horizons. These new approaches work relatively well for continuous archives, but quickly approach their conceptual limits in the presence of discontinuities. Here, I report first steps towards improving existing mathematical algorithms in their performance regarding unknown discontinuities by integrating complementary information based on variations encoded in other archives. The proposed method is based on the following ingredients: (1) a correlation estimator for arbitrarily spaced time series, (2) a maximization criterion for correlations based on a linear rescaling of the unknown time axis, (3) a procedure allowing an automatic evaluation of minimum-cost paths for performing a sophisticated version of "wiggle-matching", and (4) improving the relative chronologies by adding explicit dates via some additional penalty term. To this end, I will mainly focus on the methodological details associated with the first two steps. Here, correlations between the data set under study and the "reference" archive are evaluated for running windows along the records utilizing a recently developed non-parametric correlation estimator based on a Gaussian kernel function. Allowing for an arbitrary rescaling of the time axis around the respective window midpoint, maximum correlations arise when the windows represent the same time intervals and the rescaled time axis corrects for different material accumulation rates. For sufficiently high-resolution records, the proposed approach can be extended to account also for possible non-linear co-variations between the two considered archives or proxies. By identifying sequences of subsequent windows with particularly high correlations, relative chronologies can be obtained. Moreover, gaps in such sequences are indicative of archive discontinuities and

  11. Yeast Endosulfines Control Entry into Quiescence and Chronological Life Span by Inhibiting Protein Phosphatase 2A

    Directory of Open Access Journals (Sweden)

    Séverine Bontron

    2013-01-01

    Full Text Available The TORC1 and PKA protein kinases are central elements of signaling networks that regulate eukaryotic cell proliferation in response to growth factors and/or nutrients. In yeast, attenuation of signaling by these kinases following nitrogen and/or carbon limitation activates the protein kinase Rim15, which orchestrates the initiation of a reversible cellular quiescence program to ensure normal chronological life span. The molecular elements linking Rim15 to distal readouts including the expression of Msn2/4- and Gis1-dependent genes involve the endosulfines Igo1/2. Here, we show that Rim15, analogous to the greatwall kinase in Xenopus, phosphorylates endosulfines to directly inhibit the Cdc55-protein phosphatase 2A (PP2ACdc55. Inhibition of PP2ACdc55 preserves Gis1 in a phosphorylated state and consequently promotes its recruitment to and activation of transcription from promoters of specific nutrient-regulated genes. These results close a gap in our perception of and delineate a role for PP2ACdc55 in TORC1-/PKA-mediated regulation of quiescence and chronological life span.

  12. AFSC/REFM: Bomb-produced age validation study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish age validation with bomb-produced radiocarbon (14C) requires a known-age Delta14C reference chronology spanning the era of a marine increase in bomb-produced...

  13. Chronological Evolution of Magnetic Resonance Imaging Findings in Children With Febrile Infection-Related Epilepsy Syndrome.

    Science.gov (United States)

    Rivas-Coppola, Marianna S; Shah, Namrata; Choudhri, Asim F; Morgan, Robin; Wheless, James W

    2016-02-01

    To describe and analyze the chronological evolution of the radiological findings in seven children with febrile infection-related epilepsy syndrome. This is a retrospective study describing the radiological findings and evolution in seven children with febrile infection-related epilepsy syndrome who presented from 2009 to 2013. The children all fit the defined clinical criteria for febrile infection-related epilepsy syndrome; all had a history of normal psychomotor development who presented with acute-onset catastrophic partial status epilepticus associated with a febrile illness or unspecific infectious process. The children were identified from the author's weekly review of the pediatric inpatient service, and then the data were collected and analyzed retrospectively. Six males and one female ranging from 3 months to 9 years of age presented with status epilepticus preceded by a febrile illness. Extensive investigations for infectious, autoimmune, and metabolic etiologies were unremarkable. Multiple antiepileptic medications were attempted, including drug-induced coma in all of them, with poor response. Immunotherapy with intravenous steroids or intravenous immunoglobulin (three patients had both) was tried in six of seven patients with a poor response. Ketogenic diet was initiated in four of seven patients with limited response. Serial magnetic resonance imaging studies, done from the initial presentation through 18 months of follow-up, showed evolution from normal imaging to severe cerebral atrophy. Progressive cytotoxic edema involving mostly bilateral hippocampi and temporal lobes was appreciated in one to three weeks. At one month from seizure onset, mild to moderate cerebral atrophy and hippocampal sclerosis was appreciated that continued to progress over the next year. After six to twelve months, most of the patients showed moderate to severe cerebral atrophy and by one year, cerebellar atrophy was also appreciated. Febrile infection-related epilepsy

  14. Chronology of the Middle to Upper Palaeolithic transition at Abric Romaní, Catalunya.

    Science.gov (United States)

    Camps, Marta; Higham, Thomas

    2012-01-01

    This paper presents new data from Abric Romaní, a key site in the region of Catalunya, northeastern Iberia, which is central to discussions of the transition between the Middle and Upper Palaeolithic in Europe. Until now, the Mid-Upper Paleolithic transition had been dated at the site through samples from the remaining baulk sections of levels A and B (typologically classified as 'earliest Aurignacian' and Mousterian, respectively) at the rear of the rockshelter, which were left from excavations in the late 1900s and early 1910s. We dated samples of bone and charcoal from these remnant sections with accelerator mass spectrometry (AMS) methods. We also analysed several humanly-modified artefacts (bone points and perforated shells) excavated from other areas of the same layers. From the initial series, we obtained ages of c. 20 ka BP (thousands of years before present); much younger than expected if they indeed dated to the early Upper Palaeolithic. We sampled additional material to test the robustness of these initial ages, and older determinations that were more comparable with the chronology outlined by Bischoff et al. (1988, 1994) resulted. All of the old and new results have been compared in a Bayesian model using the new INTCAL09 (14)C calibration dataset. The results appear to confirm the suggestion of some researchers (e.g., Zilhão and d'Errico, 1999) that there was no Aurignacian in the north of Iberia until c. 36,500 BP. The chronometric model shows a good level of agreement between the radiocarbon and U-series chronologies previously obtained, and the new results published in this paper. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. High-resolution chronology of the Mekong delta coast for characterizing and predicting decadal to centennial changes

    Science.gov (United States)

    Tamura, T.; Saito, Y.; Bateman, M. D.; Nguyen, V. L.; Ta, T.; Matsumoto, D.

    2013-12-01

    Deltaic coasts have prograded over the last several millennia after the culmination of the postglacial sea-level rise to form coastal lowlands, where nowadays c. 25% of the world's population lives. Knowing past deltaic shoreline changes, especially on decadal- to centennial-scale, is essential for understanding the fate of delta in the coming decades and centuries. We tested the effectiveness of quartz optically-stimulated luminescence (OSL) dating of beach ridges to constrain shoreline changes of the Mekong River delta, southern Vietnam. Forty-seven OSL ages were analysed from the Tra Vinh delta plain, and the beach ridge sediments were found to have excellent luminescence properties resulting in low age uncertainties of c. 5 %. The OSL chronology agrees well with shoreline changes over recent decades and with radiocarbon ages of tidal flat sediment, clearly illustrating the coastal progradation over the last 3500 years. The OSL ages show no reversal and document decadal- to centennial-scale shoreline migration especially in the last 1500 years. The chronology also suggests major changes in shoreline orientation at the beginning of the Little Ice Age, related to the strengthening of the winter monsoon, and a constant progradation rate over the last 1500 years. A decrease in sand supply to the coast in the last few decades due to river dam construction and fluvial sand dredging is inferred, possibly affecting the behaviour of the modern and future shorelines, which can be compared with the less human-influenced past changes reconstructed in this study.

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

    International Nuclear Information System (INIS)

    Kondo, Norihiro; Kurita, Kenichi; Yajima, Tetsuya; Izumi, Masahiro

    2008-01-01

    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)

  17. Chronology and isotopic geochemistry of Apollo 14 basalts and Skaergard Gabbro, Eastern Greenland

    International Nuclear Information System (INIS)

    Dasch, E.J.

    1986-01-01

    Work completed on Apollo 14 basalts has been published. The two dates obtained from these rocks comprised the oldest and two of the three oldest ages (4.1 and 4.3 billion years) known for lunar maria basalts; thus their ages are important in understanding the moon's earliest history. Owing to the antiquity of these rocks, two more fragments have been dated as part of a second ASEE/NASA SFF program. The new ages are 3.95 and 4.12 billion years, thus further establishing and amplifying the earlier results. This work, although perhaps more interesting for its chronologic information, was begun as a test of chemical and petrographic models. Fragments of Apollo basalt were placed into five categories, based on petrologic and chemical, especially rare-earth element, composition. Isotopic studies were begun in an attempt to determine if the five groups of basalts were related by age or initial isotopic composition (isotopic composition of lava at time of extrusion). Although a few of the representatives of the five groups have the same age and/or initial strontium-isotopic composition, within the analtytical uncertainties, most apparently are unrelated. Petrologic implications of these data will be published in an appropriate journal

  18. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1 through Vol. 15, No. 6

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Klein, A.

    1975-04-01

    This issue of the Index to Nuclear Safety covers only articles included in Nuclear Safety, Vol. 11, No. 1, through Vol. 15, No. 6. This index is presented in three sections as follows: Chronological List of Articles by Volume; Permuted Title (KWIC) Index; and Author Index. (U.S.)

  19. New chronological data for the timing of the Saalian- and Elsterian glacial cycle in Europe - studies on a key site within the type area

    Science.gov (United States)

    Lauer, Tobias; Weiß, Marcel; Wansa, Stefan

    2017-04-01

    The type area for the Elsterian- and Saalian glacial cycles is located in central Germany (Saxony, Saxony-Anhalt and Thuringia) where the gravel deposits of the rivers Saale- and Elster interfinger with tills and meltwater deposits of both glacial cycles in proximity to the maximum extensions of the Middle-Pleistocene Scandinavian ice-sheets in Central Europe. The Elsterian- and Saalian glacial cycles, including the corresponding interglacial periods are also correlated with first human appearance in the area (see Haidle and Pawlik 2010). Nevertheless, the timing of these glacial cycles is still unclear due to a lack of resilient chronological data on sediments representing the advance- and retreat of the glaciers. The Elsterian is defined to be terminated by the Holsteinian, but for the latter, a correlation to MIS 9 or 11 is still a matter of debate (e. g. Sirocko et al. 2006; Nitychoruk et al. 2007). Consequently, a correlation of the Elsterian to MIS 10 or 12 is possible. Within the last decades, new luminescence dating techniques such as pIRIR-luminescence protocols or infrared-radiofluorescence dating made it possible to extent the datable age range and hence, it is now possible to establish reliable chronologies also for deposits beyond the last glacial-/interglacial cycle. In the present study, we dated the quaternary sequence of Uichteritz (close to the Saale-river near Weissenfels, Saxony-Anhalt) using luminescence and infrared-radiofluorescence dating. The base of the quaternary layers consists of Elsterian sediments pre-dating the first Elsterian ice advance. This is evidenced mainly by the lithology, especially the absence of Nordic components in the composition of the gravel. Additionally, remains of the advancing Saalian ice sheet, represented by fluvial sediments from the Middle-Pleistocene river Saale, as well as till, glaciofluvial and glaciolacustrine sediments, cover the Elsterian succession. The upper part of the fluvial Elsterian sediments

  20. Dental age assessment of Western Saudi children and adolescents.

    Science.gov (United States)

    Alshihri, Amin M; Kruger, Estie; Tennant, Marc

    2015-07-01

    The aim of this study was to evaluate the use of the London Atlas of Human Tooth Development and Eruption for age estimation in Saudi Arabian children and adolescents (aged 2-20 years), for forensic odontology application. This cross-sectional survey analyzed orthopantomograms (OPGs) of the complete dentition (including root development) to estimate the deviation from chronological age. Each OPG was de-identified and analyzed individually and classified into age-groups by the lead author, using the methods of the Atlas of Tooth Development. OPGs from a total of 252 patients [110 (44%) males, 142 (56%) females] aged 2-20 years (24-240 months) were examined in this study. The average estimated and chronological ages of subjects differed significantly p 12 months. This study, conducted in a sub-population of different origin than the UK sample used for the development of the London Atlas, identified variation in age estimates that may have significant impacts on results. The establishment of a composite international repository of atlas-based data for diverse ethnic sub-populations would be of great value to clinicians across the globe.

  1. Capturing total chronological and spatial uncertainties in palaeo-ice sheet reconstructions: the DATED example

    Science.gov (United States)

    Hughes, Anna; Gyllencreutz, Richard; Mangerud, Jan; Svendsen, John Inge

    2017-04-01

    Glacial geologists generate empirical reconstructions of former ice-sheet dynamics by combining evidence from the preserved record of glacial landforms (e.g. end moraines, lineations) and sediments with chronological evidence (mainly numerical dates derived predominantly from radiocarbon, exposure and luminescence techniques). However the geomorphological and sedimentological footprints and chronological data are both incomplete records in both space and time, and all have multiple types of uncertainty associated with them. To understand ice sheets' response to climate we need numerical models of ice-sheet dynamics based on physical principles. To test and/or constrain such models, empirical reconstructions of past ice sheets that capture and acknowledge all uncertainties are required. In 2005 we started a project (Database of the Eurasian Deglaciation, DATED) to produce an empirical reconstruction of the evolution of the last Eurasian ice sheets, (including the British-Irish, Scandinavian and Svalbard-Barents-Kara Seas ice sheets) that is fully documented, specified in time, and includes uncertainty estimates. Over 5000 dates relevant to constraining ice build-up and retreat were assessed for reliability and used together with published ice-sheet margin positions based on glacial geomorphology to reconstruct time-slice maps of the ice sheets' extent. The DATED maps show synchronous ice margins with maximum-minimum uncertainty bounds for every 1000 years between 25-10 kyr ago. In the first version of results (DATED-1; Hughes et al. 2016) all uncertainties (both quantitative and qualitative, e.g. precision and accuracy of numerical dates, correlation of moraines, stratigraphic interpretations) were combined based on our best glaciological-geological assessment and expressed in terms of distance as a 'fuzzy' margin. Large uncertainties (>100 km) exist; predominantly across marine sectors and other locations where there are spatial gaps in the dating record (e.g. the

  2. Recent growth coherence in long-term oak (Quercus spp.) ring width chronologies in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Dobrovolný, Petr; Rybníček, Michal; Büntgen, Ulf; Trnka, Miroslav; Brázdil, Rudolf; Stachoň, Z.; Prokop, O.; Kolář, Tomáš

    2016-01-01

    Roč. 70, 2-3 (2016), s. 133-141 ISSN 0936-577X R&D Projects: GA MŠk(CZ) LO1415; GA ČR GA13-04291S; GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : Tree-ring width chronology * Oak species * Tree-age structure * Site-specific conditions * Hydroclimate sensitivity * Czech Republic Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.578, year: 2016

  3. Radiocarbon dating and wood density chronologies of mangrove trees in arid Western Australia.

    Science.gov (United States)

    Santini, Nadia S; Hua, Quan; Schmitz, Nele; Lovelock, Catherine E

    2013-01-01

    Mangrove trees tend to be larger and mangrove communities more diverse in tropical latitudes, particularly where there is high rainfall. Variation in the structure, growth and productivity of mangrove forests over climatic gradients suggests they are sensitive to variations in climate, but evidence of changes in the structure and growth of mangrove trees in response to climatic variation is scarce. Bomb-pulse radiocarbon dating provides accurate dates of recent wood formation and tree age of tropical and subtropical tree species. Here, we used radiocarbon techniques combined with X-ray densitometry to develop a wood density chronology for the mangrove Avicennia marina in the Exmouth Gulf, Western Australia (WA). We tested whether wood density chronologies of A. marina were sensitive to variation in the Pacific Decadal Oscillation Index, which reflects temperature fluctuations in the Pacific Ocean and is linked to the instrumental rainfall record in north WA. We also determined growth rates in mangrove trees from the Exmouth Gulf, WA. We found that seaward fringing A. marina trees (~10 cm diameter) were 48 ± 1 to 89 ± 23 years old (mean ± 1 σ) and that their growth rates ranged from 4.08 ± 2.36 to 5.30 ± 3.33 mm/yr (mean ± 1 σ). The wood density of our studied mangrove trees decreased with increases in the Pacific Decadal Oscillation Index. Future predicted drying of the region will likely lead to further reductions in wood density and their associated growth rates in mangrove forests in the region.

  4. STRATIGRAPHIC AND CHRONOLOGIC FRAMEWORK OF THE UPPER MIOCENE CESSANITI SUCCESSION (VIBO VALENTIA, CALABRIA, ITALY

    Directory of Open Access Journals (Sweden)

    ANTONELLA CINZIA MARRA

    2017-08-01

    Full Text Available This study revises the mammal-bearing stratigraphic succession of Cava Gentile, near Cessaniti (Calabria, southern Italy, with the aim of dating the Late Miocene fossiliferous succession by the integration of mammal biochronology with sedimentology, magnetostratigraphy and marine biostratigraphy. Since the first discovery of mammal remains at Cessaniti, the chronological framework of the sedimentary succession was based on the biochronological significance of the mammal assemblage and on the biostratigraphic characterisation of the capping unit. Chronological control of the sedimentary succession and the age range of the mammal faunal assemblage at Cessaniti is now possible by combining the mammal biochronological constraints with biostratigraphy and the characterisation of the magnetostratigraphy of the sedimentary succession. Our study allows the conclusion that: i an overall transgressive trend is recorded at the late Tortonian succession of the Capo Vaticano area, with locally different depositional trends; ii the late Tortonian transgression was punctuated by minor episodes of forced regression, as attested by soils and fluvial deposits intercalated within the Cava Gentile succession (documented here for the first time; iii the relative sea level rises that characterised these sedimentation patterns allowed accumulation of marine and terrestrial fossils in specific transgressive horizons; iv the combination of palaeomagnetic data and biostratigraphic analyses, together with the biochronological constraints offered by the Cessaniti mammal assemblage, allows the assignment of the basal unit of the Cessaniti (Cava Gentile succession to the normal Chron C4n (8.1–7.5 Ma; and v the maximum range of the Cessaniti land mammal assemblage from Cava Gentile is about 1 Ma, bracketed between 8.1 and 7.2 Ma.

  5. Radiocarbon Dating and Wood Density Chronologies of Mangrove Trees in Arid Western Australia

    Science.gov (United States)

    Santini, Nadia S.; Hua, Quan; Schmitz, Nele; Lovelock, Catherine E.

    2013-01-01

    Mangrove trees tend to be larger and mangrove communities more diverse in tropical latitudes, particularly where there is high rainfall. Variation in the structure, growth and productivity of mangrove forests over climatic gradients suggests they are sensitive to variations in climate, but evidence of changes in the structure and growth of mangrove trees in response to climatic variation is scarce. Bomb-pulse radiocarbon dating provides accurate dates of recent wood formation and tree age of tropical and subtropical tree species. Here, we used radiocarbon techniques combined with X-ray densitometry to develop a wood density chronology for the mangrove Avicennia marina in the Exmouth Gulf, Western Australia (WA). We tested whether wood density chronologies of A. marina were sensitive to variation in the Pacific Decadal Oscillation Index, which reflects temperature fluctuations in the Pacific Ocean and is linked to the instrumental rainfall record in north WA. We also determined growth rates in mangrove trees from the Exmouth Gulf, WA. We found that seaward fringing A. marina trees (∼10 cm diameter) were 48±1 to 89±23 years old (mean ± 1σ) and that their growth rates ranged from 4.08±2.36 to 5.30±3.33 mm/yr (mean ±1σ). The wood density of our studied mangrove trees decreased with increases in the Pacific Decadal Oscillation Index. Future predicted drying of the region will likely lead to further reductions in wood density and their associated growth rates in mangrove forests in the region. PMID:24265797

  6. Cortical laminar necrosis in brain infarcts: chronological changes on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Komiyama, M. [Department of Neurosurgery, Osaka City General Hospital, 2-13-22, Miyakojima-Hondouri, Miyakojima, Osaka 534 (Japan); Nishikawa, M. [Department of Neurosurgery, Osaka City General Hospital, 2-13-22, Miyakojima-Hondouri, Miyakojima, Osaka 534 (Japan); Yasui, T. [Department of Neurosurgery, Osaka City General Hospital, 2-13-22, Miyakojima-Hondouri, Miyakojima, Osaka 534 (Japan)

    1997-07-10

    We studied the MRI characteristics of cortical laminar necrosis in ischaemic stroke. We reviewed 13 patients with cortical laminar high signal on T1-weighted images to analyse the chronological changes in signal intensity and contrast enhancement. High-density cortical lesions began to appear on T1-weighted images about 2 weeks after the ictus. At 1-2 months they were prominent. They began to fade from 3 months but could be seen up to 11 months. These cortical lesions showed isointensity or high intensity on T2-weighted images and did not show low intensity at any stage. Contrast enhancement of the laminar lesions was prominent at 1-2 months and became less apparent from 3 months, but could be seen up to 8 months. (orig.). With 6 figs., 1 tab.

  7. Luminescent microbanding in speleothems: High-resolution chronology and paleoclimate

    Science.gov (United States)

    Shopov, Y. Y.; Ford, D. C.; Schwarcz, H. P.

    1994-05-01

    When illuminated by ultraviolet light, many calcite speleothems (stalagmites, stalactites, flowstones) display luminescence caused by the presence of organic (humic) substances occluded in the calcite. The amplitude of luminescence varies in a banded pattern parallel to growth layering. Through 14C and thermal ionization mass spectrometry uranium-series dating, we show that cyclical oscillations in the luminescence have periodicities ranging from a few days to ≥105 yr. A well-defined annual cycle is present in many vadose-zone speleothems and can be used to define the chronology of short-term events. This cycle is probably a response to hydrological events in the recharge to the cave. Longer term oscillations are inferred to be controlled by climate, through its effect on organic activity in the overlying soil.

  8. Radiocarbon chronology of Manot Cave, Israel and Upper Paleolithic dispersals.

    Science.gov (United States)

    Alex, Bridget; Barzilai, Omry; Hershkovitz, Israel; Marder, Ofer; Berna, Francesco; Caracuta, Valentina; Abulafia, Talia; Davis, Lauren; Goder-Goldberger, Mae; Lavi, Ron; Mintz, Eugenia; Regev, Lior; Bar-Yosef Mayer, Daniella; Tejero, José-Miguel; Yeshurun, Reuven; Ayalon, Avner; Bar-Matthews, Mira; Yasur, Gal; Frumkin, Amos; Latimer, Bruce; Hans, Mark G; Boaretto, Elisabetta

    2017-11-01

    The timing of archeological industries in the Levant is central for understanding the spread of modern humans with Upper Paleolithic traditions. We report a high-resolution radiocarbon chronology for Early Upper Paleolithic industries (Early Ahmarian and Levantine Aurignacian) from the newly excavated site of Manot Cave, Israel. The dates confirm that the Early Ahmarian industry was present by 46,000 calibrated years before the present (cal BP), and the Levantine Aurignacian occurred at least between 38,000 and 34,000 cal BP. This timing is consistent with proposed migrations or technological diffusions between the Near East and Europe. Specifically, the Ahmarian could have led to the development of the Protoaurignacian in Europe, and the Aurignacian in Europe could have spread back to the Near East as the Levantine Aurignacian.

  9. Northeastern North American Pleistocene megafauna chronologically overlapped minimally with Paleoindians

    Science.gov (United States)

    Boulanger, Matthew T.; Lyman, R. Lee

    2014-02-01

    It has long been argued that specialized big-game-hunting Paleoindians were responsible for the extinction of three dozen large-bodied mammalian genera in North America. In northeastern North America, the overkill hypothesis cannot be tested on the basis of associations of Paleoindian artifacts and remains of extinct mammals because no unequivocal associations are known. The overkill hypothesis requires Paleoindians to be contemporaneous with extinct mammalian taxa and this provides a means to evaluate the hypothesis, but contemporaneity does not confirm overkill. Blitzkrieg may produce evidence of contemporaneity but it may not, rendering it difficult to test. Overkill and Blitzkrieg both require large megafaunal populations. Chronological data, Sporormiella abundance, genetics, and paleoclimatic data suggest megafauna populations declined prior to human colonization and people were only briefly contemporaneous with megafauna. Local Paleoindians may have only delivered the coup de grace to small scattered and isolated populations of megafauna.

  10. "EDML1": a chronology for the EPICA deep ice core from Dronning Maud Land, Antarctica, over the last 150 000 years

    Directory of Open Access Journals (Sweden)

    U. Ruth

    2007-08-01

    Full Text Available A chronology called EDML1 has been developed for the EPICA ice core from Dronning Maud Land (EDML. EDML1 is closely interlinked with EDC3, the new chronology for the EPICA ice core from Dome-C (EDC through a stratigraphic match between EDML and EDC that consists of 322 volcanic match points over the last 128 ka. The EDC3 chronology comprises a glaciological model at EDC, which is constrained and later selectively tuned using primary dating information from EDC as well as from EDML, the latter being transferred using the tight stratigraphic link between the two cores. Finally, EDML1 was built by exporting EDC3 to EDML. For ages younger than 41 ka BP the new synchronized time scale EDML1/EDC3 is based on dated volcanic events and on a match to the Greenlandic ice core chronology GICC05 via 10Be and methane. The internal consistency between EDML1 and EDC3 is estimated to be typically ~6 years and always less than 450 years over the last 128 ka (always less than 130 years over the last 60 ka, which reflects an unprecedented synchrony of time scales. EDML1 ends at 150 ka BP (2417 m depth because the match between EDML and EDC becomes ambiguous further down. This hints at a complex ice flow history for the deepest 350 m of the EDML ice core.

  11. 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

  12. Paleotempestological chronology developed from gas ion source AMS analysis of carbonates determined through real-time Bayesian statistical approach

    Science.gov (United States)

    Wallace, D. J.; Rosenheim, B. E.; Roberts, M. L.; Burton, J. R.; Donnelly, J. P.; Woodruff, J. D.

    2014-12-01

    Is a small quantity of high-precision ages more robust than a higher quantity of lower-precision ages for sediment core chronologies? AMS Radiocarbon ages have been available to researchers for several decades now, and precision of the technique has continued to improve. Analysis and time cost is high, though, and projects are often limited in terms of the number of dates that can be used to develop a chronology. The Gas Ion Source at the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS), while providing lower-precision (uncertainty of order 100 14C y for a sample), is significantly less expensive and far less time consuming than conventional age dating and offers the unique opportunity for large amounts of ages. Here we couple two approaches, one analytical and one statistical, to investigate the utility of an age model comprised of these lower-precision ages for paleotempestology. We use a gas ion source interfaced to a gas-bench type device to generate radiocarbon dates approximately every 5 minutes while determining the order of sample analysis using the published Bayesian accumulation histories for deposits (Bacon). During two day-long sessions, several dates were obtained from carbonate shells in living position in a sediment core comprised of sapropel gel from Mangrove Lake, Bermuda. Samples were prepared where large shells were available, and the order of analysis was determined by the depth with the highest uncertainty according to Bacon. We present the results of these analyses as well as a prognosis for a future where such age models can be constructed from many dates that are quickly obtained relative to conventional radiocarbon dates. This technique currently is limited to carbonates, but development of a system for organic material dating is underway. We will demonstrate the extent to which sacrificing some analytical precision in favor of more dates improves age models.

  13. Rare earth element carriers in the Shergotty meteorite and implications for its chronology

    Science.gov (United States)

    Lundberg, Laura L.; Crozaz, Ghislaine; Zinner, Ernst; Mckay, Gordon

    1988-01-01

    This paper reports on the results of ion-probe measurements of REE concentrations in individual grains of the Shergotty meteorite. The phases analyzed included whitlockite, apatite, baddeleyite, augite, pigeonite, maskelynite, and K-rich glass; the whitlockite and apatite phases were also analyzed for U. Results indicate that whitlockite contains the bulk of the REE in Shergotty, with no evidence for distinct light-REE patterns in texturally different whitlockites. The results on the evolution of the REE abundances in the Shergotty late-stage interstitial melt, inferred from the analysis of whitlockite, are consistent with closed system crystallization. No metasomatic alteration is required to explain the REE data. It is concluded that there is no compelling reason to attribute chronological significance to the Sm-Nd array, as was done by Jagoutz and Waenke (1986).

  14. School Attendance Patterns, Unmet Educational Needs, and Truancy: A Chronological Perspective

    Science.gov (United States)

    Spencer, Andrea M.

    2009-01-01

    This study examines chronological patterns of attendance and academic performance of urban students who are identified as truants in Grade 8. A chronological review of 42 student records, from school entry through Grade 8, identified high frequencies of absenteeism and academic performance issues beginning at school entry and, in many cases,…

  15. Rewiring yeast acetate metabolism through MPC1 loss of function leads to mitochondrial damage and decreases chronological lifespan

    Directory of Open Access Journals (Sweden)

    Ivan Orlandi

    2014-11-01

    Full Text Available During growth on fermentable substrates, such as glucose, pyruvate, which is the end-product of glycolysis, can be used to generate acetyl-CoA in the cytosol via acetaldehyde and acetate, or in mitochondria by direct oxidative decarboxylation. In the latter case, the mitochondrial pyruvate carrier (MPC is responsible for pyruvate transport into mitochondrial matrix space. During chronological aging, yeast cells which lack the major structural subunit Mpc1 display a reduced lifespan accompanied by an age-dependent loss of autophagy. Here, we show that the impairment of pyruvate import into mitochondria linked to Mpc1 loss is compensated by a flux redirection of TCA cycle intermediates through the malic enzyme-dependent alternative route. In such a way, the TCA cycle operates in a “branched” fashion to generate pyruvate and is depleted of intermediates. Mutant cells cope with this depletion by increasing the activity of glyoxylate cycle and of the pathway which provides the nucleocytosolic acetyl-CoA. Moreover, cellular respiration decreases and ROS accumulate in the mitochondria which, in turn, undergo severe damage. These acquired traits in concert with the reduced autophagy restrict cell survival of the mpc1∆ mutant during chronological aging. Conversely, the activation of the carnitine shuttle by supplying acetyl-CoA to the mitochondria is sufficient to abrogate the short-lived phenotype of the mutant.

  16. A chronology of hurricane landfalls at Little Sippewissett Marsh, Massachusetts, USA, using optical dating

    Science.gov (United States)

    Madsen, A. T.; Duller, G. A. T.; Donnelly, J. P.; Roberts, H. M.; Wintle, A. G.

    2009-08-01

    Optical dating has been applied to sediments preserved in Little Sippewissett Marsh, Massachusetts, USA, which are associated with overwashing of the beach barrier during hurricane strikes on the coast. The aims were to determine the hurricane landfall frequency, and make comparisons with independent age control and the historical record. Written sources of hurricane activity along the American east coast are only considered reliable back to the mid 19th century, but the sedimentary record is potentially much longer. Optical dating was applied to quartz grains extracted from thirteen samples within a sediment core from the salt-marsh. Variability in the luminescence characteristics between aliquots was observed and ~ 33% of the measured aliquots were discarded based upon the ratio of the fast component to the medium component. The majority of the samples gave normal dose distributions implying homogeneous resetting of the luminescence signal at the time of deposition, but three of the samples required application of the minimum age model (MAM). Ages ranging between 20 ± 2 and 594 ± 38 years were obtained and are broadly in agreement with independent chronologies, thus demonstrating the potential of optical dating in this setting. The hurricane record based upon optical dating extends approximately 300 years further back in time than the official National Oceanic Atmospheric Administration (NOAA) record. The localised nature of hurricane landfalls means that it will be necessary to collect multiple cores from a number of different sites in order to build up a complete hurricane record for this part of the coast.

  17. 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.

  18. High-resolution chronologies for loess: comparing AMS 14C and optical dating results

    Science.gov (United States)

    Lang, A.; Hatté, C.; Rousseau, D.-D.; Antoine, P.; Fontugne, M.; Zöller, L.; Hambach, U.

    2003-05-01

    The Nußloch loess section in South West Germany is famous in Central Europe for its thick deposits from the Last Glacial Maximum. It has therefore been intensively studied during the past few years and offers an excellent opportunity to compare the performance of different dating techniques covering the period 15-45 ka. Here we present results from optical and AMS 14C dating. The silt-sized polymineral fraction of the clastic sediments and a multiple-aliquot approach was used for IR-OSL dating. 14C dating was carried out on organic macro-remnants and humin fractions extracted from the sediments. With the exception of samples taken from the uppermost 1.5 m of the section, IR-OSL and calibrated 14C-AMS ages are consistent over the entire period. The inconsistencies in the upper meters are thought to be due to disturbances during soil formation in the Holocene. The good agreement obtained on the remaining sequence demonstrates the high accuracy of both methods when studying loess sections: for the IR-OSL ages no significant age underestimations are obvious. The results clearly document that accurate chronologies can be developed for such continental sedimentary sequences. This gives access to archives that can now be studied with a high temporal resolution and allows the establishment of new paleoclimatic proxies for the study of terrestrial responses to past climatic changes.

  19. An optical luminescence chronology for late Pleistocene aeolian activity in the Colombian and Venezuelan Llanos

    Science.gov (United States)

    Carr, Andrew S.; Armitage, Simon J.; Berrío, Juan-Carlos; Bilbao, Bibiana A.; Boom, Arnoud

    2016-03-01

    The lowland savannas (Llanos) of Colombia and Venezuela are covered by extensive aeolian landforms for which little chronological information exists. We present the first optically stimulated luminescence (OSL) age constraints for dunes in the Llanos Orientales of lowland Colombia and new ages for dunes in the Venezuelan Llanos. The sampled dunes are fully vegetated and show evidence of post-depositional erosion. Ages range from 4.5 ± 0.4 to 66 ± 4 ka, with the majority dating to 27-10 ka (Marine Isotope Stage 2). Some dunes accumulated quickly during the last glacial maximum, although most were active 16-10 ka. Accretion largely ceased after 10 ka. All dunes are elongated downwind from rivers, parallel with dry season winds, and are interpreted as source-bordering features. As they are presently isolated from fluvial sediments by gallery forest it is proposed that activity was associated with a more prolonged dry season, which restricted gallery forest, leading to greater sediment availability on river shorelines. Such variability in dry season duration was potentially mediated by the mean latitude of the ITCZ. The cessation of most dune accretion after ca. 10 ka suggests reduced seasonality and a more northerly ITCZ position, consistent with evidence from the Cariaco Basin.

  20. Developing a visual moraine classification scheme to support investigations into the Holocene glacier chronology of the Southern Alps, New Zealand

    Science.gov (United States)

    Kaufung, Eva; Winkler, Stefan

    2014-05-01

    The Southern Alps of New Zealand have provided one of only a few suitable study sites for investigating Holocene glacier chronologies in the mid-latitudinal Southern Hemisphere. Although a considerable number of studies have been conducted during the past few decades, these generally focus on a very limited number of glacier forelands. Additionally, those glaciers studied have often been selected because of their accessibility rather than their representativeness for the whole region. A common drawback of many regional studies is the lack of attention to glacial geomorphology and the mode of moraine formation with the dating of such landforms in chronological context. With the Southern Alps characterized by very dynamic geomorphological process-systems and a high seismic activity, this seems unfortunate as it causes a relatively high potential "geomorphological uncertainty" with any published glacier chronology and its subsequent palaeoclimatological interpretation. Future investigations into the Holocene glacier chronology in the Southern Alps need to address those existing shortcomings and, consequently, should achieve a representative spatial distribution of study sites in order to overcome the current strong data bias towards few, albeit relatively well-studied glacier forelands. The specific regional geomorphological environment of the Southern Alps requires, furthermore, a thorough assessment of any moraine selected for the subsequent dating in consideration of its "reliability" if it is considered as evidence of specific former glacier variations. With more than 3000 potential glacier forelands in the entire mountain range, careful selection of future targets for successful chronological field work is essential. We present the preliminary results of an ongoing, time-efficient study to apply different remote sensing sources (aerial photography, Google Earth, satellite images) to evaluate the potential of certain glacier forelands for detailed ground

  1. Stratigraphy and chronology of a 15 ka sequence of multi-sourced silicic tephras in a montane peat bog, eastern North Island, New Zealand

    International Nuclear Information System (INIS)

    Lowe, D.J.; Newnham, R.M.; Ward, C.M.

    1999-01-01

    We document the stratigraphy, composition, and chronology of a succession of 16 distal, silicic tephra layers interbedded with lateglacial and Holocene peats and muds up to c. 15 000 radiocarbon years (c. 18 000 calendar years) old at a montane site (Kaipo Bog) in eastern North Island, New Zealand. Aged from 665 + or - 15 to 14 700 + or - 95 14 C yr BP, the tephras are derived from six volcanic centres in North Island, three of which are rhyolitic (Okataina, Taupo, Maroa), one peralkaline (Tuhua), and two andesitic (Tongariro, Egmont). Correlations are based on multiple criteria: field properties and stratigraphic interrelationships, ferromagnesian silicate mineral assemblages, glass-shard major element composition (from electron microprobe analysis), and radiocarbon dating. We extend the known distribution of tephras in eastern North Island and provide compositional data that add to their potential usefulness as isochronous markers. The chronostratigraphic framework established for the Kaipo sequence, based on both site-specific and independently derived tephra-based radiocarbon ages, provides the basis for fine-resolution paleoenvironmental studies at a climatically sensitive terrestrial site from the mid latitudes of the Southern Hemisphere. Tephras identified as especially useful paleoenvironmental markers include Rerewhakaaitu and Waiohau (lateglacial), Konini (late-glacial-early Holocene), Tuhua (middle Holocene), and Taupo and Kaharoa (late Holocene). (author). 102 refs., 3 tabs., 3 figs

  2. Into the Past: A Step Towards a Robust Kimberley Rock Art Chronology.

    Science.gov (United States)

    Ross, June; Westaway, Kira; Travers, Meg; Morwood, Michael J; Hayward, John

    2016-01-01

    The recent establishment of a minimum age estimate of 39.9 ka for the origin of rock art in Sulawesi has challenged claims that Western Europe was the locus for the production of the world's earliest art assemblages. Tantalising excavated evidence found across northern Australian suggests that Australia too contains a wealth of ancient art. However, the dating of rock art itself remains the greatest obstacle to be addressed if the significance of Australian assemblages are to be recognised on the world stage. A recent archaeological project in the northwest Kimberley trialled three dating techniques in order to establish chronological markers for the proposed, regional, relative stylistic sequence. Applications using optically-stimulated luminescence (OSL) provided nine minimum age estimates for fossilised mudwasp nests overlying a range of rock art styles, while Accelerator Mass Spectrometry radiocarbon (AMS 14C) results provided an additional four. Results confirm that at least one phase of the northwest Kimberley rock art assemblage is Pleistocene in origin. A complete motif located on the ceiling of a rockshelter returned a minimum age estimate of 16 ± 1 ka. Further, our results demonstrate the inherent problems in relying solely on stylistic classifications to order rock art assemblages into temporal sequences. An earlier than expected minimum age estimate for one style and a maximum age estimate for another together illustrate that the Holocene Kimberley rock art sequence is likely to be far more complex than generally accepted with different styles produced contemporaneously well into the last few millennia. It is evident that reliance on techniques that produce minimum age estimates means that many more dating programs will need to be undertaken before the stylistic sequence can be securely dated.

  3. Into the Past: A Step Towards a Robust Kimberley Rock Art Chronology.

    Directory of Open Access Journals (Sweden)

    June Ross

    Full Text Available The recent establishment of a minimum age estimate of 39.9 ka for the origin of rock art in Sulawesi has challenged claims that Western Europe was the locus for the production of the world's earliest art assemblages. Tantalising excavated evidence found across northern Australian suggests that Australia too contains a wealth of ancient art. However, the dating of rock art itself remains the greatest obstacle to be addressed if the significance of Australian assemblages are to be recognised on the world stage. A recent archaeological project in the northwest Kimberley trialled three dating techniques in order to establish chronological markers for the proposed, regional, relative stylistic sequence. Applications using optically-stimulated luminescence (OSL provided nine minimum age estimates for fossilised mudwasp nests overlying a range of rock art styles, while Accelerator Mass Spectrometry radiocarbon (AMS 14C results provided an additional four. Results confirm that at least one phase of the northwest Kimberley rock art assemblage is Pleistocene in origin. A complete motif located on the ceiling of a rockshelter returned a minimum age estimate of 16 ± 1 ka. Further, our results demonstrate the inherent problems in relying solely on stylistic classifications to order rock art assemblages into temporal sequences. An earlier than expected minimum age estimate for one style and a maximum age estimate for another together illustrate that the Holocene Kimberley rock art sequence is likely to be far more complex than generally accepted with different styles produced contemporaneously well into the last few millennia. It is evident that reliance on techniques that produce minimum age estimates means that many more dating programs will need to be undertaken before the stylistic sequence can be securely dated.

  4. Long-term growth-increment chronologies reveal diverse influences of climate forcing on freshwater and forest biota in the Pacific Northwest

    Science.gov (United States)

    Black, Bryan A.; Dunham, Jason B.; Blundon, Brett W.; Brim-Box, Jayne; Tepley, Alan J.

    2015-01-01

    Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Here, we develop a network of eight growth-increment width chronologies for freshwater mussel species in the Pacific Northwest, United States and integrate them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years (October 1–September 30) was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies (1982–2003; PC1mussel) accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge (PC1discharge; r = −0.88; P nature of the relationships varied across the landscape. Negative correlations occurred in forests where tree growth tends to be limited by drought while positive correlations occurred in forests where tree growth tends to be limited by deep or lingering snowpack. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change.

  5. Tick-Tock Chimes the Kidney Clock – from Biology of Renal Ageing to Clinical Applications

    Directory of Open Access Journals (Sweden)

    Joshua Rowland

    2018-01-01

    Full Text Available Ageing of the kidney is a multi-dimensional process that occurs simultaneously at the molecular, cellular, histological, anatomical and physiological level. Nephron number and renal cortical volume decline, renal tubules become atrophic and glomeruli become sclerotic with age. These structural changes are accompanied by a decline in glomerular filtration rate, decreased sodium reabsorption and potassium excretion, reduced urinary concentrating capacity and alterations in the endocrine activity of the kidney. However, the pace of progression of these changes is not identical in everyone - individuals of the same age and seemingly similar clinical profile often exhibit stark differences in the age-related decline in renal health. Thus, chronological age poorly reflects the time-dependent changes that occur in the kidney. An ideal measure of renal vitality is biological kidney age – a measure of the age-related changes in physiological function. Replacing chronological age with biological age could provide numerous clinical benefits including improved prognostic accuracy in renal transplantation, better stratification of risk and identification of those who are on a fast trajectory to an age-related drop in kidney health.

  6. Application of OSL and 10Be techniques to the establishment of deglaciation chronology in Estonia

    International Nuclear Information System (INIS)

    Raukas, Anto

    2004-01-01

    The deglaciation history of Estonia has been under research for about a century. Despite the great number of publications devoted to this subject and marked improvements in study methods, many problems of topical interest have not been solved yet, especially due to the lack of good direct dating methods. In this paper the suitability of OSL and 10 Be dating techniques for establishing accurate deglaciation chronology for Estonia is assessed. Turbidity and water depth, velocity of outwash streams and transport length, possible fast sedimentation at night hours or below the ice, incorporation of older, unbleached particles, and other factors affected the extent of the bleaching of the TL signal in different ways, causing great variability of dates. Surface inclination, height of the surface over ground, snow and vegetation cover, and evolution of water bodies influenced the calculation of reliable exposure ages of objects dated using the 10 Be method. It means that age determinations of both glaciofluvial deposits with the OSL method and erratic boulders with the 1B e method are highly problematic, especially for glaciofluvial intertill sediments where the exact genesis of deposits is unknown and for boulders, which have been in the forest, under the waters of proglacial lakes and/or the Baltic Sea, or under snow cover for a long time. (author)

  7. The EDC3 chronology for the EPICA Dome C ice core

    Directory of Open Access Journals (Sweden)

    F. Parrenin

    2007-08-01

    Full Text Available The EPICA (European Project for Ice Coring in Antarctica Dome C drilling in East Antarctica has now been completed to a depth of 3260 m, at only a few meters above bedrock. Here we present the new EDC3 chronology, which is based on the use of 1 a snow accumulation and mechanical flow model, and 2 a set of independent age markers along the core. These are obtained by pattern matching of recorded parameters to either absolutely dated paleoclimatic records, or to insolation variations. We show that this new time scale is in excellent agreement with the Dome Fuji and Vostok ice core time scales back to 100 kyr within 1 kyr. Discrepancies larger than 3 kyr arise during MIS 5.4, 5.5 and 6, which points to anomalies in either snow accumulation or mechanical flow during these time periods. We estimate that EDC3 gives accurate event durations within 20% (2σ back to MIS11 and accurate absolute ages with a maximum uncertainty of 6 kyr back to 800 kyr.

  8. 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.

  9. Extension of Saccharomyces paradoxus chronological lifespan by retrotransposons in certain media conditions is associated with changes in reactive oxygen species.

    Science.gov (United States)

    VanHoute, David; Maxwell, Patrick H

    2014-10-01

    Retrotransposons are mobile DNA elements present throughout eukaryotic genomes that can cause mutations and genome rearrangements when they replicate through reverse transcription. Increased expression and/or mobility of retrotransposons has been correlated with aging in yeast, Caenorhabditis elegans, Drosophila melanogaster, and mammals. The many copies of retrotransposons in humans and various model organisms complicate further pursuit of this relationship. The Saccharomyces cerevisiae Ty1 retrotransposon was introduced into a strain of S. paradoxus that completely lacks retrotransposons to compare chronological lifespans (CLSs) of yeast strains with zero, low, or high Ty1 copy number. Yeast chronological lifespan reflects the progressive loss of cell viability in a nondividing state. Chronological lifespans for the strains were not different in rich medium, but were extended in high Ty1 copy-number strains in synthetic medium and in rich medium containing a low dose of hydroxyurea (HU), an agent that depletes deoxynucleoside triphosphates. Lifespan extension was not strongly correlated with Ty1 mobility or mutation rates for a representative gene. Buffering deoxynucleoside triphosphate levels with threonine supplementation did not substantially affect this lifespan extension, and no substantial differences in cell cycle arrest in the nondividing cells were observed. Lifespan extension was correlated with reduced reactive oxygen species during early stationary phase in high Ty1 copy strains, and antioxidant treatment allowed the zero Ty1 copy strain to live as long as high Ty1 copy-number strains in rich medium with hydroxyurea. This exceptional yeast system has identified an unexpected longevity-promoting role for retrotransposons that may yield novel insights into mechanisms regulating lifespan. Copyright © 2014 by the Genetics Society of America.

  10. 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.

  11. The chronology of reindeer hunting on Norway's highest ice patches

    Science.gov (United States)

    Pilø, Lars; Finstad, Espen; Ramsey, Christopher Bronk; Martinsen, Julian Robert Post; Nesje, Atle; Solli, Brit; Wangen, Vivian; Callanan, Martin

    2018-01-01

    The melting of perennial ice patches globally is uncovering a fragile record of alpine activity, especially hunting and the use of mountain passes. When rescued by systematic fieldwork (glacial archaeology), this evidence opens an unprecedented window on the chronology of high-elevation activity. Recent research in Jotunheimen and surrounding mountain areas of Norway has recovered over 2000 finds—many associated with reindeer hunting (e.g. arrows). We report the radiocarbon dates of 153 objects and use a kernel density estimation (KDE) method to determine the distribution of dated events from ca 4000 BCE to the present. Interpreted in light of shifting environmental, preservation and socio-economic factors, these new data show counterintuitive trends in the intensity of reindeer hunting and other high-elevation activity. Cold temperatures may sometimes have kept humans from Norway's highest elevations, as expected based on accessibility, exposure and reindeer distributions. In times of increasing demand for mountain resources, however, activity probably continued in the face of adverse or variable climatic conditions. The use of KDE modelling makes it possible to observe this patterning without the spurious effects of noise introduced by the discrete nature of the finds and the radiocarbon calibration process. PMID:29410869

  12. 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.

  13. Holographic protection of chronology in universes of the Goedel type

    International Nuclear Information System (INIS)

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

    2003-01-01

    We analyze the structure of supersymmetric Goedel-like cosmological solutions of string theory. Just as the original four-dimensional Goedel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on the 'phenomenological' aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Goedel 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 Goedel universes has many features in common with de Sitter space, suggesting that Goedel 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 Goedel universes in string theory. We show that Goedel universes are T dual to pp waves, and use this fact to generate new Goedel-like solutions of string and M theory by T dualizing known supersymmetric pp-wave solutions

  14. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Klein, A.

    1977-01-01

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication

  15. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1977-02-23

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication.

  16. Physiological frailty index (PFI): quantitative in-life estimate of individual biological age in mice.

    Science.gov (United States)

    Antoch, Marina P; Wrobel, Michelle; Kuropatwinski, Karen K; Gitlin, Ilya; Leonova, Katerina I; Toshkov, Ilia; Gleiberman, Anatoli S; Hutson, Alan D; Chernova, Olga B; Gudkov, Andrei V

    2017-03-19

    The development of healthspan-extending pharmaceuticals requires quantitative estimation of age-related progressive physiological decline. In humans, individual health status can be quantitatively assessed by means of a frailty index (FI), a parameter which reflects the scale of accumulation of age-related deficits. However, adaptation of this methodology to animal models is a challenging task since it includes multiple subjective parameters. Here we report a development of a quantitative non-invasive procedure to estimate biological age of an individual animal by creating physiological frailty index (PFI). We demonstrated the dynamics of PFI increase during chronological aging of male and female NIH Swiss mice. We also demonstrated acceleration of growth of PFI in animals placed on a high fat diet, reflecting aging acceleration by obesity and provide a tool for its quantitative assessment. Additionally, we showed that PFI could reveal anti-aging effect of mTOR inhibitor rapatar (bioavailable formulation of rapamycin) prior to registration of its effects on longevity. PFI revealed substantial sex-related differences in normal chronological aging and in the efficacy of detrimental (high fat diet) or beneficial (rapatar) aging modulatory factors. Together, these data introduce PFI as a reliable, non-invasive, quantitative tool suitable for testing potential anti-aging pharmaceuticals in pre-clinical studies.

  17. A randomised double-blind placebo-controlled pilot trial of a combined extract of sage, rosemary and melissa, traditional herbal medicines, on the enhancement of memory in normal healthy subjects, including influence of age.

    Science.gov (United States)

    Perry, N S L; Menzies, R; Hodgson, F; Wedgewood, P; Howes, M-J R; Brooker, H J; Wesnes, K A; Perry, E K

    2018-01-15

    To evaluate for the first time the effects of a combination of sage, rosemary and melissa (Salvia officinalis L., Rosmarinus officinalis L. and Melissa officinalis L.; SRM), traditional European medicines, on verbal recall in normal healthy subjects. To devise a suitable study design for assessing the clinical efficacy of traditional herbal medicines for memory and brain function. Forty-four normal healthy subjects (mean age 61 ± 9.26y SD; m/f 6/38) participated in this study. A double-blind, randomised, placebo-controlled pilot study was performed with subjects randomised into an active and placebo group. The study consisted of a single 2-week term ethanol extract of SRM that was chemically-characterised using high resolution LC-UV-MS/MS analysis. Immediate and delayed word recall were used to assess memory after taking SRM or placebo (ethanol extract of Myrrhis odorata (L.) Scop.). In addition analysis was performed with subjects divided into younger and older subgroups (≤ 62 years mean age n = 26: SRM n = 10, Placebo n = 16; ≥ 63 years n = 19: SRM n = 13, Placebo n = 6). Overall there were no significant differences between treatment and placebo change from baseline for immediate or delayed word recall. However subgroup analysis showed significant improvements to delayed word recall in the under 63 year age group (p memory in healthy subjects under 63 years of age. Short- and long- term supplementation with SRM extract merits more robust investigation as an adjunctive treatment for patients with Alzheimer's disease and in the general ageing population. The study design proved a simple cost effective trial protocol to test the efficacy of herbal medicines on verbal episodic memory, with future studies including broader cognitive assessment. Copyright © 2017 Elsevier GmbH. All rights reserved.

  18. Ice age plant refugia in East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1979-01-01

    From the distribution of plants it has been inferred by some botanists that ice-free areas existed in East Greenland accommodating a flora which survived one or several ice ages in the area. Comparing this evidence with recent information on the chronology of glaciations and post-glacial vegetation...... of Greenland. 14 C dating and amino-acid age estimates of marine sediments show that lowland areas near the outer coast have been ice-free for at least 40,000 years. The vegetation history, as reflected in pollen diagrams extending back to ca. 10,000 yr. B.P., has shown that many of the extant species...... immigrated from northern Europe and North America in post-glacial times. This contingency includes both some thermophilous species that were suggested as survivors by one group of botanists, and some extremely "hardy" species that were thought to have survived by another group. From the palynological...

  19. The luminescence dating chronology of a deep core from Bosten Lake (NW China) in arid central Asia reveals lake evolution over the last 220 ka

    DEFF Research Database (Denmark)

    Li, Guoqiang; Duan, Yanwu; Huang, Xiaozhong

    2016-01-01

    The lacustrine deposits of lakes in arid central Asia (ACA) potentially record palaeoclimatic changes on orbital and suborbital time scales, but such changes are still poorly understood due to the lack of reliable chronologies. Bosten Lake, the largest freshwater inland lake in China, is located...... in the southern Tianshan Mountains in central ACA. A 51.6-m-deep lacustrine succession was retrieved from the lake and 30 samples from the succession were used for luminescence dating to establish a chronology based on multi-grain quartz OSL and K-feldspar post-IR IRSL (pIRIR290) dating. Quartz OSL ages were only......-level fluctuations in the lakes of ACA may not respond directly to climatic changes and may be affected by a number of complex factors....

  20. Luminescence dating of flash flood deposits: a new approach for the chronological study of ancient irrigation perimeters in southern Yemen

    International Nuclear Information System (INIS)

    Balescu, S.; Lamothe, M.; Coque-Delhuille, B.

    1998-01-01

    This study is an attempt to assess the age of ancient irrigation silts from Southern Yemen using the optically stimulated luminescence (OSL) of the constituent K-feldspar grains. This OSL dating method is tested on the al-Haraja irrigation sequence (Wadi Bayhan) which overlies an archaeological occupation level previously dated at 2 203±123 years BP by 14 C. The OSL age estimates range between 2 097±177 years at the bottom of the sequence and 1 555±150 years at the top. This study demonstrates the potential of the luminescence dating method to provide chronological information on the deposition of ancient silts following irrigation in arid environment where 14 C datable material is rare. (authors)

  1. 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.

  2. RELATIVE AND ABSOLUTE CHRONOLOGY OF YAMNAYA AND CATACOMB MONUMENTS THE ISSUE OF CO-EXISTENCE

    OpenAIRE

    Telegin, Dmitriy Y.; Pustovalov, Sergey Z.; Kovalyukh, Nikolay N.

    2003-01-01

    This volume of the Baltic-Pontic Studies is a record of investigations carried out under the research project begun earlier in vol. 7 ("The Foundations of radiocarbon chronology of cultures between the Vistula and Dnieper: 3150-1850 BC", Poznań 1999). Here, the approach is broader in terms of chronology and culture. Our purpose has been to fill taxonomic gaps hitherto present in the discussion (supplementing the dating of cultures, groups or phases) or reanalyze the grounds for findings consi...

  3. Autophagy and leucine promote chronological longevity and respiration proficiency during calorie restriction in yeast

    OpenAIRE

    Aris, John P.; Alvers, Ashley L.; Ferraiuolo, Roy A.; Fishwick, Laura K.; Hanvivatpong, Amanda; Hu, Doreen; Kirlew, Christine; Leonard, Michael T.; Losin, Kyle J.; Marraffini, Michelle; Seo, Arnold Y.; Swanberg, Veronica; Westcott, Jennifer L.; Wood, Michael S.; Leeuwenburgh, Christiaan

    2013-01-01

    We have previously shown that autophagy is required for chronological longevity in the budding yeast Saccharomyces cerevisiae. Here we examine the requirements for autophagy during extension of chronological life span (CLS) by calorie restriction (CR). We find that autophagy is upregulated by two CR interventions that extend CLS: water wash CR and low glucose CR. Autophagy is required for full extension of CLS during water wash CR under all growth conditions tested. In contrast, autophagy was...

  4. Chronology of the early period of the Ananyino cultural and historical area

    OpenAIRE

    Kuzminykh Sergei V.; Chizhevsky Anrdei A.

    2014-01-01

    Problems related to the chronology of the early period in the Ananyino cultural and historical area development are discussed in the article. The chronology is based upon the objects imported from the Black Sea region, Northern Caucasus and Transcaucasia and their Ananyino replicas or imitations. Radiocarbon dates have also been taken into account. The period under consideration is divided into two stages (I-1 and I-2). They are characterized by differing technological facilities that had det...

  5. ESR dating and the human evolution: contribution to the chronology of the earliest humans in Europe

    Science.gov (United States)

    Falguères, Christophe

    2003-05-01

    In the last 20 years, the electron spin resonance (ESR) dating method has allowed the establishment of a chronological time frame over most of the history of human evolution. Despite many difficulties found for ESR dating of bones and carbonates, tooth enamel dated by ESR has been proven as a reliable method in its application to fossil teeth and quartz. Both of the latter materials have allowed dating of Early and Middle Pleistocene sites which are not datable using other methods such as the Argon-Argon method. In particular, recent discoveries of human remains in western Europe have been proposed to be sites of the earliest arrival of humans there, and have been dated to the Early Pleistocene by ESR using quartz and tooth enamel. Combined ESR and U-series dating of fossil herbivore teeth are the only means of dating layers from which such ancient remains have been recovered in western Europe. Good examples are the sites of Atapuerca Gran Dolina, Spain and Visogliano, Italy which have been dated using tooth enamel. When no bones and teeth can be found in prehistoric sites, ESR dating on quartz extracted from sediments has been used to date sites whose ages range over the entire Quaternary period. We present here two examples that occur in fluvial terraces of the river Creuse, France and at Monte Poggiolo site, Italy, where several artefacts of an archaic pebble industry have been recovered.

  6. Oxygen availability strongly affects chronological lifespan and thermotolerance in batch cultures of Saccharomyces cerevisiae

    Science.gov (United States)

    Bisschops, Markus M.; Vos, Tim; Martínez-Moreno, Rubén; Cortés, Pilar T.; Pronk, Jack T.; Daran-Lapujade, Pascale

    2015-01-01

    Stationary-phase (SP) batch cultures of Saccharomyces cerevisiae, in which growth has been arrested by carbon-source depletion, are widely applied to study chronological lifespan, quiescence and SP-associated robustness. Based on this type of experiments, typically performed under aerobic conditions, several roles of oxygen in aging have been proposed. However, SP in anaerobic yeast cultures has not been investigated in detail. Here, we use the unique capability of S. cerevisiae to grow in the complete absence of oxygen to directly compare SP in aerobic and anaerobic bioreactor cultures. This comparison revealed strong positive effects of oxygen availability on adenylate energy charge, longevity and thermotolerance during SP. A low thermotolerance of anaerobic batch cultures was already evident during the exponential growth phase and, in contrast to the situation in aerobic cultures, was not substantially increased during transition into SP. A combination of physiological and transcriptome analysis showed that the slow post-diauxic growth phase on ethanol, which precedes SP in aerobic, but not in anaerobic cultures, endowed cells with the time and resources needed for inducing longevity and thermotolerance. When combined with literature data on acquisition of longevity and thermotolerance in retentostat cultures, the present study indicates that the fast transition from glucose excess to SP in anaerobic cultures precludes acquisition of longevity and thermotolerance. Moreover, this study demonstrates the importance of a preceding, calorie-restricted conditioning phase in the acquisition of longevity and stress tolerance in SP yeast cultures, irrespective of oxygen availability. PMID:28357268

  7. Time in tortoiseshell: a bomb radiocarbon-validated chronology in sea turtle scutes.

    Science.gov (United States)

    Van Houtan, Kyle S; Andrews, Allen H; Jones, T Todd; Murakawa, Shawn K K; Hagemann, Molly E

    2016-01-13

    Some of the most basic questions of sea turtle life history are also the most elusive. Many uncertainties surround lifespan, growth rates, maturity and spatial structure, yet these are critical factors in assessing population status. Here we examine the keratinized hard tissues of the hawksbill (Eretmochelys imbricata) carapace and use bomb radiocarbon dating to estimate growth and maturity. Scutes have an established dietary record, yet the large keratin deposits of hawksbills evoke a reliable chronology. We sectioned, polished and imaged posterior marginal scutes from 36 individual hawksbills representing all life stages, several Pacific populations and spanning eight decades. We counted the apparent growth lines, microsampled along growth contours and calibrated Δ(14)C values to reference coral series. We fit von Bertalanffy growth function (VBGF) models to the results, producing a range of age estimates for each turtle. We find Hawaii hawksbills deposit eight growth lines annually (range 5-14), with model ensembles producing a somatic growth parameter (k) of 0.13 (range 0.1-0.2) and first breeding at 29 years (range 23-36). Recent bomb radiocarbon values also suggest declining trophic status. Together, our results may reflect long-term changes in the benthic community structure of Hawaii reefs, and possibly shed light on the critical population status for Hawaii hawksbills. © 2016 The Author(s).

  8. Mood disorders in eating disorder patients: Prevalence and chronology of ONSET.

    Science.gov (United States)

    Godart, N; Radon, L; Curt, F; Duclos, J; Perdereau, F; Lang, F; Venisse, J L; Halfon, O; Bizouard, P; Loas, G; Corcos, M; Jeammet, Ph; Flament, M F

    2015-10-01

    In a clinical population, we estimated the frequency of mood disorders among 271 patients suffering from Anorexia Nervosa (AN) and Bulimia Nervosa (BN) in comparison to a control group matched for age and gender. The frequency of mood disorders was measured using the Mini International Neuropsychiatric Interview (MINI), DSM-IV version. Mood disorders were more frequent among eating disorder (ED) patients than among controls, with a global prevalence of the order of 80% for each ED group. The majority of the mood disorders comorbid with ED were depressive disorders (MDD and dysthymia). The relative chronology of onset of these disorders was equivocal, because mood disorders in some cases preceded and in others followed the onset of the eating disorders. Our sample was characterized by patients with severe ED and high comorbidities, and thus do not represent the entire population of AN or BN. This also may have resulted in an overestimation of prevalence. Mood disorders appear significantly more frequently in patients seeking care for ED than in controls. These results have implications for the assessment and treatment of ED patients, and for the aetio-pathogenesis of these disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Chronological study of {sup 137}Cs input to the Black Sea deep and shelf sediments

    Energy Technology Data Exchange (ETDEWEB)

    Gulin, S.B.; Polikarpov, G.G.; Egorov, V.N. [A.O. Kovalevsky Institute of Biology of the Southern Seas, Sevastopol (Ukraine); Aarkrog, A.; Nielsen, S.P. [Risoe National Laboratory, Roskilde (Denmark)

    1997-12-31

    The chart of the post-Chernobyl {sup 137}Cs distribution in the upper Black Sea sediments was made. The field of sediments with the highest {sup 137}Cs activity was found near the Danube River mouth. The age of sediment layers as well as the sedimentation rates were calculated from {sup 137}Cs vertical profiles in the top of the uncompacted sediments nearby the Danube (11.5 mm yr{sup -1}), the NW Black Sea slope (2.2 mm yr{sup -1}) and the deepest western area (0.4 mm yr{sup -1}). Subsequent assessments showed the high distinction of {sup 137}Cs sedimentary fluxes and inventories between these sites related to different contributions of terrigenous matter in the sediments, as traced by {sup 40}K. The results allow to reconstruct chronology of {sup 137}Cs input to the Black Sea over the last decades. The traced three most notable phases correspond well with the periods of active nuclear weapon testings in the 1950`s and 1960`s as well as of the Chernobyl NPP accident. The post-Chernobyl dynamics of {sup 137}Cs activity in the near Danube sediments traced from its dated profile was like that observed during the annual monitoring. (author) 8 refs.

  10. Chronological study of 137Cs input to the Black Sea deep and shelf sediments

    International Nuclear Information System (INIS)

    Gulin, S.B.; Polikarpov, G.G.; Egorov, V.N.; Aarkrog, A.; Nielsen, S.P.

    1997-01-01

    The chart of the post-Chernobyl 137 Cs distribution in the upper Black Sea sediments was made. The field of sediments with the highest 137 Cs activity was found near the Danube River mouth. The age of sediment layers as well as the sedimentation rates were calculated from 137 Cs vertical profiles in the top of the uncompacted sediments nearby the Danube (11.5 mm yr -1 ), the NW Black Sea slope (2.2 mm yr -1 ) and the deepest western area (0.4 mm yr -1 ). Subsequent assessments showed the high distinction of 137 Cs sedimentary fluxes and inventories between these sites related to different contributions of terrigenous matter in the sediments, as traced by 40 K. The results allow to reconstruct chronology of 137 Cs input to the Black Sea over the last decades. The traced three most notable phases correspond well with the periods of active nuclear weapon testings in the 1950's and 1960's as well as of the Chernobyl NPP accident. The post-Chernobyl dynamics of 137 Cs activity in the near Danube sediments traced from its dated profile was like that observed during the annual monitoring. (author)

  11. Oxygen availability strongly affects chronological lifespan and thermotolerance in batch cultures of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Markus M.M. Bisschops

    2015-10-01

    Full Text Available Stationary-phase (SP batch cultures of Saccharomyces cerevisiae, in which growth has been arrested by carbon-source depletion, are widely applied to study chronological lifespan, quiescence and SP-associated robustness. Based on this type of experiments, typically performed under aerobic conditions, several roles of oxygen in aging have been proposed. However, SP in anaerobic yeast cultures has not been investigated in detail. Here, we use the unique capability of S. cerevisiae to grow in the complete absence of oxygen to directly compare SP in aerobic and anaerobic bioreactor cultures. This comparison revealed strong positive effects of oxygen availability on adenylate energy charge, longevity and thermotolerance during SP. A low thermotolerance of anaerobic batch cultures was already evident during the exponential growth phase and, in contrast to the situation in aerobic cultures, was not substantially increased during transition into SP. A combination of physiological and transcriptome analysis showed that the slow post-diauxic growth phase on ethanol, which precedes SP in aerobic, but not in anaerobic cultures, endowed cells with the time and resources needed for inducing longevity and thermotolerance. When combined with literature data on acquisition of longevity and thermotolerance in retentostat cultures, the present study indicates that the fast transition from glucose excess to SP in anaerobic cultures precludes acquisition of longevity and thermotolerance. Moreover, this study demonstrates the importance of a preceding, calorie-restricted conditioning phase in the acquisition of longevity and stress tolerance in SP yeast cultures, irrespective of oxygen availability.

  12. Chronology of the cave interior sediments at Gran Dolina archaeological site, Atapuerca (Spain)

    Science.gov (United States)

    Parés, J. M.; Álvarez, C.; Sier, M.; Moreno, D.; Duval, M.; Woodhead, J. D.; Ortega, A. I.; Campaña, I.; Rosell, J.; Bermúdez de Castro, J. M.; Carbonell, E.

    2018-04-01

    The so-called "Gran Dolina site" (Atapuerca mountain range, N Spain) is a karstic cavity filled by sediments during the Pleistocene, some of which contain a rich ensemble of archaeological and paleontological records. These sediments have contributed significantly to our understanding of early human dispersal in Europe but, in contrast, older, interior facies deposits have received much less of attention. The stratigraphy of Gran Dolina reveals an abrupt sedimentary change of interior to entrance facies from bottom to top, reflecting a significant paleoenvironmental change that promoted the accumulation of sediments transported from the vicinity of the cave by water or "en masse". Since the major magnetic polarity reversal known as the Matuyama-Brunhes boundary (0.78 Ma) was detected within the TD7 unit in the middle of the stratigraphic section, we carried out a new combined paleomagnetic, radiometric (U-Pb), and electron spin resonance (ESR) dating study of the lower part of the sequence in order to constrain the chronology of the interior facies at Gran Dolina. U-Pb analysis of speleothems did not produce age information as the samples proved to be extremely unradiogenic. The magnetic stratigraphy of the cave interior sediments reveals a dominant reverse magnetic polarity, coherent with a Matuyama age, and interrupted by a normal polarity magnetozone interpreted as the Jaramillo Subchron (1.0-1.1 Ma). ESR ages on quartz grains from the upper part of the interior facies sediments are coherent with such an interpretation. We conclude that the fluvial deposits (interior facies) that constitute the cave floor began accumulating before 1.2 Ma. The development of large cave entrances at Gran Dolina occurred shortly after the Jaramillo Subchron but before ca 900 ka ago.

  13. Application of sedimentary and chronological analyses to refine the depositional context of a Late Pleistocene vertebrate deposit, Naracoorte, South Australia

    Science.gov (United States)

    Macken, Amy C.; Jankowski, Nathan R.; Price, Gilbert J.; Bestland, Erick A.; Reed, Elizabeth H.; Prideaux, Gavin J.; Roberts, Richard G.

    2011-09-01

    Cave deposits of infill sediments and associated vertebrate fossils provide a valuable source of information on terrestrial palaeoenvironments, climatic conditions and palaeocommunities. In the deposits of the Naracoorte Caves World Heritage Area, such records span the last 500 ka and are renowned for their rich, diverse vertebrate assemblages. Previous research into the Grant Hall deposit of Victoria Fossil Cave suggested that it may preserve the only peak last interglacial (ca. 125 ka) faunal community within the World Heritage Area. The current work tested this existing model for the age of faunal remains from Grant Hall using multiple techniques. Physical and geochemical properties of the visually homogeneous sediments were analysed at regular intervals through the sequence to establish meaningful stratigraphic divisions and sediment provenance. Optically stimulated luminescence dating of individual quartz grains indicates that sediments accumulated in Grant Hall from 93 ± 8 to 70 ± 5 ka. Minimum ages provided by U/Th dating of fossil teeth (72.3 ± 2.2 to 38.2 ± 0.8 ka) are consistent with the luminescence chronology, and show that the deposit represents a more recent faunal accumulation than previously modelled for the site. U/Th ages on calcite straws within the deposit are significantly older than the sediments and fossil teeth (>500 to 186.4 ± 1 ka). As such they provide no further constraint on the chronology of the deposit but do indicate that speleothem deposition was active over much of the Middle Pleistocene. Sedimentary analyses resulted in the identification of five depositional units, contrasting with previous divisions which were based only on visual observation of the sedimentary sequence. Sediments within each unit are broadly classified as sandy silts with soil structures and may be indirectly derived from the lunettes of nearby Bool Lagoon, although their ultimate provenance is unknown. As a result of this work, palaeoenvironmental

  14. Chronology of desert margin in western India using improved ...

    Indian Academy of Sciences (India)

    A combination of NCF-SAR protocol and sample specific equivalent dose computation helped in arriving at better age estimate for present samples. The study also compares the criteria for the selection of different age models that are used at present. The age of the alluvial sequence is now bracketed between 10 ka (upper ...

  15. The use of information theory for the evaluation of biomarkers of aging and physiological age.

    Science.gov (United States)

    Blokh, David; Stambler, Ilia

    2017-04-01

    The present work explores the application of information theoretical measures, such as entropy and normalized mutual information, for research of biomarkers of aging. The use of information theory affords unique methodological advantages for the study of aging processes, as it allows evaluating non-linear relations between biological parameters, providing the precise quantitative strength of those relations, both for individual and multiple parameters, showing cumulative or synergistic effect. Here we illustrate those capabilities utilizing a dataset on heart disease, including diagnostic parameters routinely available to physicians. The use of information-theoretical methods, utilizing normalized mutual information, revealed the exact amount of information that various diagnostic parameters or their combinations contained about the persons' age. Based on those exact informative values for the correlation of measured parameters with age, we constructed a diagnostic rule (a decision tree) to evaluate physiological age, as compared to chronological age. The present data illustrated that younger subjects suffering from heart disease showed characteristics of people of higher age (higher physiological age). Utilizing information-theoretical measures, with additional data, it may be possible to create further clinically applicable information-theory-based markers and models for the evaluation of physiological age, its relation to age-related diseases and its potential modifications by therapeutic interventions. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Sources and chronology of nitrate contamination in spring waters, Suwannee River basin, Florida

    Science.gov (United States)

    Katz, Brian G.; Hornsby, H.D.; Bohlke, J.K.; Mokray, M.F.

    1999-01-01

    A multi-tracer approach, which consisted of analyzing water samples for n aturally occurring chemical and isotopic indicators, was used to better understand sources and chronology of nitrate contamination in spring wate rs discharging to the Suwannee and Santa Fe Rivers in northern Florida. Dur ing 1997 and 1998, as part of a cooperative study between the Suwannee River Water Management District and the U.S. Geological Survey, water samples were collected and analyzed from 24 springs and two wells for major ions, nutrients, dissolved organic carbon, and selected environmental isotopes [18O/16O, D/H, 13C/12C, 15N/14N]. To better understand when nitrate entered the ground-water system, water samples were analyzed for chlorofluorocarbons (CFCs; CCl3F, CCl2F2, and C2Cl3F3) and tritium (3H); in this way, the apparent ages and residence times of spring waters and water from shallow zones in the Upper Floridan aquifer were determined. In addition to information obtained from the use of isotopic and other chemical tracers, information on changes in land-use activities in the basin during 1954-97 were used to estimate nitrogen inputs from nonpoint sources for five counties in the basin. Changes in nitrate concentrations in spring waters with time were compared with estimated nitrogen inputs for Lafayette and Suwannee Counties. Agricultural activities [cropland farming, animal farming operations (beef and dairy cows, poultry, and swine)] along with atmospheric deposition have contributed large quantities of nitrogen to ground water in the Suwannee River Basin in northern Florida. Changes in agricultural land use during the past 40 years in Alachua, Columbia, Gilchrist, Lafayette, and Suwannee Counties have contributed variable amounts of nitrogen to the ground-water system. During 1955-97, total estimated nitrogen from all nonpoint sources (fertilizers, animal wastes, atmospheric deposition, and septic tanks) increased continuously in Gilchrist and Lafayette Counties. In

  17. Dental age estimation in the living after completion of third molar mineralization: new data for Gustafson's criteria.

    Science.gov (United States)

    Timme, M; Timme, W H; Olze, A; Ottow, C; Ribbecke, S; Pfeiffer, H; Dettmeyer, R; Schmeling, A

    2017-03-01

    There is a need for dental age estimation methods after completion of the third molar mineralization. Degenerative dental characteristics appear to be suitable for forensic age diagnostics beyond the 18th year of life. In 2012, Olze et al. investigated the criteria studied by Gustafson using orthopantomograms. The objective of this study was to prove the applicability and reliability of this method with a large cohort and a wide age range, including older individuals. For this purpose, 2346 orthopantomograms of 1167 female and 1179 male Germans aged 15 to 70 years were reviewed. The characteristics of secondary dentin formation, cementum apposition, periodontal recession and attrition were evaluated in all the mandibular premolars. The correlation of the individual characteristics with the chronological age was examined by means of a stepwise multiple regression analysis, in which the chronological age formed the dependent variable. Following those results, R 2 values amounted to 0.73 to 0.8; the standard error of estimate was 6.8 to 8.2 years. Fundamentally, the recommendation for conducting age estimations in the living by these methods can be shared. The values for the quality of the regression are, however, not precise enough for a reliable age estimation around regular retirement date ages. More precise regression formulae for the age group of 15 to 40 years of life are separately presented in this study. Further research should investigate the influence of ethnicity, dietary habits and modern health care on the degenerative characteristics in question.

  18. Natural Besnoitia besnoiti infections in cattle: chronology of disease progression.

    Science.gov (United States)

    Gollnick, Nicole S; Scharr, Julia C; Schares, Gereon; Langenmayer, Martin C

    2015-02-14

    Bovine besnoitiosis is an emerging protozoan disease in cattle. Neither vaccines nor chemotherapeutic drugs are currently available for prevention and treatment of Besnoitia besnoiti infections. Therefore the implementation of appropriate disease management strategies is of utmost importance. The aim of this longitudinal study was to complement current knowledge on the chronology of disease progression. This was realized by correlating clinical findings in early stages of naturally acquired bovine besnoitiosis with results of real-time PCR of skin biopsies and of two western immunoblots and an immunofluorescent antibody test (IFAT). Animals for this study were obtained by i) closely monitoring a cow-calf operation with a high prevalence of bovine besnoitiosis for cases of acute disease, and by ii) conducting a 12-week cohabitation experiment on pasture with five healthy heifers, a healthy bull and five B. besnoiti infected cows. A control group of six healthy heifers was kept at a minimal distance of 20 m. Further, the spectrum of potential insect vectors was determined. Infected cattle were followed up to a maximum of 221 days after first detection of B. besnoiti antibodies. Two severely affected cows developed visible and palpable alterations of skin, a decrease in body condition despite good feed intake, and chronic bovine besnoitiosis-associated laminitis leading to non-healing sole ulcers. The cows also had high reciprocal IFAT titers and high loads of parasite DNA in skin samples. Two heifers developed a mild clinical course characterized by few parasitic cysts visible in the scleral conjunctivae and vestibula vaginae. Both heifers became infected during the time of high insect activity of the species Musca domestica, Musca autumnalis, Haematobia irritans, and Stomoxys calcitrans. When a third heifer became subclinically infected, low insect activity was recorded. None of the six control heifers contracted a B. besnoiti infection. In chronic besnoitiosis

  19. Duration and Eruptive Chronology of CAMP: Implications for Central Atlantic Rifting and the Triassic-Jurassic Boundary

    Science.gov (United States)

    Nomade, S.; Knight, K. B.; Beutel, E.; Renne, P. R.; Verati, C.; Feraud, G.; Marzoli, A.

    2005-12-01

    The Central Atlantic Magmatic Province (CAMP) is among the largest igneous provinces on Earth, emplaced synchronously with or just prior to the Triassic-Jurassic boundary ca. 200 Ma. In great part due to the controversial connection between the occurrence of CAMP and the events of the Triassic-Jurassic boundary, the demand for better constraints on the duration and eruptive chronology of this province has increased. A careful review and selection of available ages, as well as 16 new ages from the Carolinas, Newark basin (US), French Guyana and Morocco are presented. Judicious selection yields a total of 59 dates for CAMP, ranging from 202 to 190 Ma covering every part of the CAMP. Extrusive activity commenced abruptly around 200 Ma, reaching peak volume and intensity around 199 Ma on the African margin. The main period of CAMP magmatism is confirmed as brief, but is suggested to consist of at least two phases over 1.5 Ma, during which time data suggest a southward migration of the magmatism from the Africa-North American margins towards South America. Two volumetrically minor, but distinctive magmatic peaks at 195 and 192 Ma are mirrored in data from all three continents, highlighted by our statistical approach. Despite significant advances in our understanding of the chronology of CAMP, we emphasize that the lack of a well-defined Triassic-Jurassic boundary age, as well as an absence of relevant comparison between U/Pb and Ar/Ar data for this time period remain limiting factors to unambiguously linking CAMP in time with the events of the Triassic-Jurassic boundary.

  20. Bone age assessment by digital images

    International Nuclear Information System (INIS)

    Silva, Ana Maria Marques da

    1996-01-01

    An algorithm which allows bone age assessment by digital radiological images was developed. For geometric parameters extraction, the phalangeal and metacarpal regions of interest are enhanced and segmented, through spatial and morphological filtering. This study is based on perimeter, length and area, from distal to proximal portions. The quantification of these parameters make possible comparison between chronological and skeletal age, using growth standard tables

  1. Is expanding HPV vaccination programs to include school-aged boys likely to be value-for-money: a cost-utility analysis in a country with an existing school-girl program

    Science.gov (United States)

    2014-01-01

    Background Similar to many developed countries, vaccination against human papillomavirus (HPV) is provided only to girls in New Zealand and coverage is relatively low (47% in school-aged girls for dose 3). Some jurisdictions have already extended HPV vaccination to school-aged boys. Thus, exploration of the cost-utility of adding boys’ vaccination is relevant. We modeled the incremental health gain and costs for extending the current girls-only program to boys, intensifying the current girls-only program to achieve 73% coverage, and extension of the intensive program to boys. Methods A Markov macro-simulation model, which accounted for herd immunity, was developed for an annual cohort of 12-year-olds in 2011 and included the future health states of: cervical cancer, pre-cancer (CIN I to III), genital warts, and three other HPV-related cancers. In each state, health sector costs, including additional health costs from extra life, and quality-adjusted life-years (QALYs) were accumulated. The model included New Zealand data on cancer incidence and survival, and other cause mortality (all by sex, age, ethnicity and deprivation). Results At an assumed local willingness-to-pay threshold of US$29,600, vaccination of 12-year-old boys to achieve the current coverage for girls would not be cost-effective, at US$61,400/QALY gained (95% UI $29,700 to $112,000; OECD purchasing power parities) compared to the current girls-only program, with an assumed vaccine cost of US$59 (NZ$113). This was dominated though by the intensified girls-only program; US$17,400/QALY gained (95% UI: dominant to $46,100). Adding boys to this intensified program was also not cost-effective; US$128,000/QALY gained, 95% UI: $61,900 to $247,000). Vaccination of boys was not found to be cost-effective, even for additional scenarios with very low vaccine or program administration costs – only when combined vaccine and administration costs were NZ$125 or lower per dose was vaccination of boys cost

  2. Is expanding HPV vaccination programs to include school-aged boys likely to be value-for-money: a cost-utility analysis in a country with an existing school-girl program.

    Science.gov (United States)

    Pearson, Amber L; Kvizhinadze, Giorgi; Wilson, Nick; Smith, Megan; Canfell, Karen; Blakely, Tony

    2014-06-26

    Similar to many developed countries, vaccination against human papillomavirus (HPV) is provided only to girls in New Zealand and coverage is relatively low (47% in school-aged girls for dose 3). Some jurisdictions have already extended HPV vaccination to school-aged boys. Thus, exploration of the cost-utility of adding boys' vaccination is relevant. We modeled the incremental health gain and costs for extending the current girls-only program to boys, intensifying the current girls-only program to achieve 73% coverage, and extension of the intensive program to boys. A Markov macro-simulation model, which accounted for herd immunity, was developed for an annual cohort of 12-year-olds in 2011 and included the future health states of: cervical cancer, pre-cancer (CIN I to III), genital warts, and three other HPV-related cancers. In each state, health sector costs, including additional health costs from extra life, and quality-adjusted life-years (QALYs) were accumulated. The model included New Zealand data on cancer incidence and survival, and other cause mortality (all by sex, age, ethnicity and deprivation). At an assumed local willingness-to-pay threshold of US$29,600, vaccination of 12-year-old boys to achieve the current coverage for girls would not be cost-effective, at US$61,400/QALY gained (95% UI $29,700 to $112,000; OECD purchasing power parities) compared to the current girls-only program, with an assumed vaccine cost of US$59 (NZ$113). This was dominated though by the intensified girls-only program; US$17,400/QALY gained (95% UI: dominant to $46,100). Adding boys to this intensified program was also not cost-effective; US$128,000/QALY gained, 95% UI: $61,900 to $247,000).Vaccination of boys was not found to be cost-effective, even for additional scenarios with very low vaccine or program administration costs - only when combined vaccine and administration costs were NZ$125 or lower per dose was vaccination of boys cost-effective. These results suggest that

  3. Human Gastric Mucosal Hydrophobicity Does dot Decrease with Helicobacter Pylori Infection or Chronological Age

    Directory of Open Access Journals (Sweden)

    Mohammed S Al-Marhoon

    2005-01-01

    Full Text Available BACKGROUND AND AIMS: Infection with cytotoxin-associated gene A (cagA Helicobacter pylori is associated with severe gastric diseases. Previous studies in humans have reported a decreased gastric hydrophobicity with H pylori infection. The aim of the present study was to differentiate between the effect of cagA+ and cagA- strains on gastric mucus hydrophobicity.

  4. THE IRON AGE AROUND THE MEDITERRANEAN : A HIGH CHRONOLOGY PERSPECTIVE FROM THE GRONINGEN RADIOCARBON DATABASE

    NARCIS (Netherlands)

    van der Plicht, J.; Bruins, H.J.; Nijboer, A.J.

    2009-01-01

    In this paper, we present an overview of radiocarbon dating contributions from Groningen, concerning 9 sites from around the Mediterranean region: Israel, Sinai (Egypt), Jordan, Spain, Tunisia, and Italy. Full date lists of the 9 sites are presented. Our (14)C dates are discussed in terms of present

  5. Developing a postglacial rockfall chronology in the mountainous fjord landscape of western Norway

    Science.gov (United States)

    Laute, Katja; Beylich, Achim A.; Winkler, Stefan

    2015-04-01

    Large areas of glacially sculpted mountain landscapes worldwide exhibit a high spatial density of postglacial rockfalls and rock-slope failures. However, the temporal patterns of rock-slope failure frequencies after Deglaciation are still fairly unknown. The mountainous fjord landscape in western Norway represents a suitable study area as it exhibits a high number of rockfalls and rock-slope failures within a region with a well known Deglaciation history. Two steep, parabolic-shaped and glacier-connected neighbouring drainage basins, Erdalen (79.5 km2) and Bødalen (60.1 km2), located on the western side of the Jostedalsbreen ice cap in western Norway are selected as study areas. The focus of this study is on (i) the temporal reconstruction of rockfalls and rock-slope failures within the two defined and nearly lithologically homogenous study areas and (ii) the identification and explanation of possible triggering and controlling factors of the investigated rock-slope failures. First investigations have started by applying Schmidt-hammer exposure-age dating (SHD) at seven larger rockfall deposits as well as at five moraines of known age within both study areas. During the sampling 50 to 100 impacts using a mechanical Proceq N-type instrument were taken from the surface of 5 to 50 single rockfall boulders located at the outer margin of the rockfall deposits. In order to avoid sampling of more recent rockfalls or redistributed debris material the sampling strategy selected preferred a larger number of individual boulders sampled with few impacts over sampling just a small number of boulders with a high number of multiple impacts. First results show that the mean rebound (R-) values measured at the seven rockfall deposits fall into recognizably different age categories. Based on the SHD measurements obtained from the moraines of known age, the determined rockfall age categories are situated between the Preboral and Little Ice Age period. The chronology and possible

  6. Age estimation based on pulp/tooth volume ratio measured on cone-beam CT images.

    Science.gov (United States)

    Gulsahi, Ayse; Kulah, Cemal Kivanc; Bakirarar, Batuhan; Gulen, Orhan; Kamburoglu, Kivanc

    2018-01-01

    After tooth eruption, the size of the pulp cavity decreases with age owing to deposition of secondary dentine. The aim of this study was to investigate the relation between the chronological age and the ratio of pulp volume (PV) to tooth volume (TV) measurements using CBCT images of single rooted teeth. Maxillary anterior, canine and mandibular canine/premolar CBCT scans of patients older than 15 years of age were collected from the archives between 2013 and 2015 years. Patients with CBCT scans of teeth were seen in detail and patients with known chronological age were included. Teeth with caries, filling or crown restorations, periapical pathologies or pulps that could not be identified were excluded. Consequently, 204 patients with 655 teeth were evaluated. The PV and the TV of each tooth was measured and then the PV/TV ratio was calculated. Simple linear regression analysis was performed in order to predict age estimation by using PV/TV. The PV/TV of all teeth ranged between 0.01 and 0.08. A negative correlation was found between the PV/TV ratio and age (p 0.05). This study revealed that PV/TV ratio was not gender dependent and the strongest correlation was found between the age and PV/TV ratio measured on maxillary central incisors than other teeth.

  7. A Chronologic Dual-Hemisphere Approach to the Last Glacial Termination from the Southern Alps of New Zealand and the Altai Mountains of Western Mongolia

    Science.gov (United States)

    Strand, P.; Putnam, A. E.; Schaefer, J. M.; Denton, G.; Barrell, D.; Putnam, D.; Schwartz, R.; Sambuu, O.; Radue, M. J.; Lindsay, B. J.; Stevens, J.

    2017-12-01

    Understanding the processes that drove the last glacial termination in the tropics and mid-latitudes is a major unresolved problem in paleoclimate. The most recent glacial to interglacial transition represents the last great global warming and the last time CO2 rose by a substantial amount before the industrial period. Determining the speed of this warming will help refine the global climate system sensitivity to CO2 and will place ongoing global warming into a paleoclimatic context. Here, we test possible drivers of the last glacial termination by comparing chronologies of mountain glaciers, which are highly sensitive to changes in atmospheric temperature, in the middle latitudes of both polar hemispheres. The dating of glacier landforms, such as moraine ridges constructed along glacier margins, affords quantitative insight into past climate conditions. We present 10Be surface-exposure chronologies and glacial geomorphologic maps of mountain glacier recession since the Last Glacial Maximum in the Southern Alps of New Zealand (44°S, 170°E) and in the Altai Mountains of western Mongolia (49°N, 88°E). On the basis of these chronologies from opposing hemispheres, we evaluate the relative roles of rising atmospheric CO2, local insolation forcing, and ocean-atmosphere reorganizations in driving the global warming that ended the last ice age.

  8. Biological Age Predictors

    Directory of Open Access Journals (Sweden)

    Juulia Jylhävä

    2017-07-01

    Full Text Available The search for reliable indicators of biological age, rather than chronological age, has been ongoing for over three decades, and until recently, largely without success. Advances in the fields of molecular biology have increased the variety of potential candidate biomarkers that may be considered as biological age predictors. In this review, we summarize current state-of-the-art findings considering six potential types of biological age predictors: epigenetic clocks, telomere length, transcriptomic predictors, proteomic predictors, metabolomics-based predictors, and composite biomarker predictors. Promising developments consider multiple combinations of these various types of predictors, which may shed light on the aging process and provide further understanding of what contributes to healthy aging. Thus far, the most promising, new biological age predictor is the epigenetic clock; however its true value as a biomarker of aging requires longitudinal confirmation.

  9. Back to the future: Epigenetic clock plasticity towards healthy aging.

    Science.gov (United States)

    Declerck, Ken; Vanden Berghe, Wim

    2018-01-11

    Aging is the most important risk factor for major human lifestyle diseases, including cancer, neurological and cardiometabolic disorders. Due to the complex interplay between genetics, lifestyle and environmental factors, some individuals seem to age faster than others, whereas centenarians seem to have a slower aging process. Therefore, a biochemical biomarker reflecting the relative biological age would be helpful to predict an individual's health status and aging disease risk. Although it is already known for years that cumulative epigenetic changes occur upon aging, DNA methylation patterns were only recently used to construct an epigenetic clock predictor for biological age, which is a measure of how well your body functions compared to your chronological age. Moreover, the epigenetic DNA methylation clock signature is increasingly applied as a biomarker to estimate aging disease susceptibility and mortality risk. Finally, the epigenetic clock signature could be used as a lifestyle management tool to monitor healthy aging, to evaluate preventive interventions against chronic aging disorders and to extend healthy lifespan. Dissecting the mechanism of the epigenetic aging clock will yield valuable insights into the aging process and how it can be manipulated to improve health span. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Chronology of the Third – Fifth Centuries Male Graves from the Tarasovo Burial Ground

    Directory of Open Access Journals (Sweden)

    Goldina Rimma D.

    2016-09-01

    Full Text Available The article focuses on the chronological attribution of male graves from the late Mazunino stage of the Tarasovo burial ground and is a sequel to an earlier article about dating of the early Nyrgynda stage (1st – 2nd centuries of the same site. The three main methods employed in this research include those of formal typology, cultural stratigraphy and the nearest neighbor method. Eighty-six male graves of the third-fifth centuries were analyzed, with 12 identified as a result: first half of the 3rd c. AD (group 1, second half of the 3rd c. AD (2; 3rd c. (3; first half of the 4th c. (group 4; second half of the 3rd – 4th c. (5; third quarter of the 4th c. (6; fourth quarter of the 4th c. (group 7; second half of the 4th c. (8; second half of the 4th – 5th c. (9; 4th – 5th cc. (10; second half of the 3rd – 5th cc. (11 and 3rd – 5th cc. (12. This article minutes investigates the first six groups, while the rest will be covered in the next publication. Artifacts form the third – fifth century female graves of the Tarasovo burial ground will be studied separately.

  11. Documentary-derived chronologies of rainfall variability in Antigua, Lesser Antilles, 1770–1890

    Directory of Open Access Journals (Sweden)

    A. J. Berland

    2013-06-01

    Full Text Available This paper presents the first extensive reconstruction of precipitation variability in the Lesser Antilles using historical documentary sources. Over 13 250 items of documentation pertaining to Antigua from the period 1769–1890 were consulted, including missionary, plantation and governmental papers as well as contemporary scholarly publications. Based on the predominant meteorological conditions observed throughout the island, each "rain-year" (December–November was assigned one of five classifications (very wet, wet, "normal", dry and very dry. Local weather references relating to seven plantations in central-eastern Antigua were grouped according to dry (December–April and wet seasons (May–November, each of which were also categorised in the aforementioned manner. Results comprise individual island-wide and central-eastern Antiguan chronologies of relative precipitation levels, spanning the rain-years 1769–70 to 1889–90 and 1769–70 to 1853–54 respectively. The former is compared with available instrumental data for the years 1870–1890. Significant dry phases are identified in the rain-years 1775–80, 1788–91, 1820–22, 1834–37, 1844–45, 1859–60, 1862–64, 1870–74 and 1881–82, while wet episodes were 1771–74, 1833–34, 1837–38, 1841–44, 1845–46 and 1878–81. Evidence for major wet and dry spells is presented and findings are evaluated within wider historical and palaeoclimatic contexts.

  12. Age, human performance, and physical employment standards.

    Science.gov (United States)

    Kenny, Glen P; Groeller, Herbert; McGinn, Ryan; Flouris, Andreas D

    2016-06-01

    The proportion of older workers has increased substantially in recent years, with over 25% of the Canadian labour force aged ≥55 years. Along with chronological age comes age-related declines in functional capacity associated with impairments to the cardiorespiratory and muscular systems. As a result, older workers are reported to exhibit reductions in work output and in the ability to perform and/or sustain the required effort when performing work tasks. However, research has presented some conflicting views on the consequences of aging in the workforce, as physically demanding occupations can be associated with improved or maintained physical function. Furthermore, the current methods for evaluating physical function in older workers often lack specificity and relevance to the actual work tasks, leading to an underestimation of physical capacity in the older worker. Nevertheless, industry often lacks the appropriate information and/or tools to accommodate the aging workforce, particularly in the context of physical employment standards. Ultimately, if appropriate workplace strategies and work performance standards are adopted to optimize the strengths and protect against the vulnerability of the aging workers, they can perform as effectively as their younger counterparts. Our aim in this review is to evaluate the impact of different individual (including physiological decline, chronic disease, lifestyle, and physical activity) and occupational (including shift work, sleep deprivation, and cold/heat exposure) factors on the physical decline of older workers, and therefore the risk of work-related injuries or illness.

  13. Violet stimulated luminescence dating of quartz from Luochuan (Chinese loess plateau): Agreement with independent chronology up to ∼600 ka

    DEFF Research Database (Denmark)

    Ankjærgaard, C.; Guralnik, B.; Buylaert, Jan-Pieter

    2016-01-01

    Luminescence dating at the Luochuan loess type (China) section is at present limited to ∼0.1 Ma using quartz blue light stimulated luminescence (BLSL), but can be extended back in time to ∼0.5 Ma by resorting to the more developmental post-infrared infrared stimulated luminescence (post-IR IRSL...... demonstrate that the Multi-Aliquot Additive-Dose (MAAD) protocol produces a VSL chronology at Luochuan which is in agreement with independent ages up to ∼0.6 Ma. For a more representative environmental dose rate of ∼2 Gy/ka (∼35% lower than at Luochuan), the documented range of MAAD-VSL sensitivity (200...

  14. Blood DNA methylation age is not associated with cognitive functioning in middle-aged monozygotic twins

    DEFF Research Database (Denmark)

    Starnawska, A; Tan, Q; Lenart, A

    2016-01-01

    . In 486 monozygotic twins, we investigated the association of DNAmAge, difference between DNAmAge and chronological age and age acceleration with cognition. Despite using a powerful paired twin design, we found no evidence for association of blood DNAmAge with cognitive abilities. This observation...... reported in a recent intrapair twin study where epigenetically older twins had increased mortality risk in comparison to their co-twins. In the study presented here, we hypothesize that DNAmAge in blood is associated with cross-sectional and longitudinal cognitive abilities in middle-aged individuals...... was confirmed in unpaired analyses, where DNAmAge initially correlated with cognitive abilities, until adjusting for chronological age. Overall, our study shows that for middle-aged individuals DNAmAge calculated in blood does not correlate with cognitive abilities....

  15. Establishment of an absolute chronology for the 18th Egyptian Dynasty

    International Nuclear Information System (INIS)

    Quiles, A.

    2011-01-01

    The establishment of an absolute chronology for Ancient Egypt is an ambition which has concentrated efforts of many scholars since the beginning of Egyptology. Thanks to historical and archaeological documents, a relative chronology of the kings has been built. Only some astrophysical points and synchronisms listed in texts (Greek and Egyptian sources) have given some ankle points which have led to some propositions of absolute chronology. At first, we will see how we can re-calculate some ankle points by using Sothic dating and modelling lunar dates with a Bayesian approach. Then, radiocarbon measurements have been done at Laboratoire de Mesure du Carbone 14 (CEA Saclay) on Egyptian short life materials like plants or twigs. These objects come from the Louvre Museum and are attributed to a particular reign and a precise period. With a Bayesian approach, these analyses have been combined with the known succession and length of the reign. Besides, Sothic and lunar dates have been incorporated as a prior in the model. It has led to propose an absolute chronology for the 18th dynasty. Finally, we will discuss the agreement between our results and archaeological evidence and will see if this chronology can highlight points where Egyptologists disagree. (author)

  16. Chronology of desert margin in western India using improved ...

    Indian Academy of Sciences (India)

    Naveen Chauhan

    2017-11-23

    Nov 23, 2017 ... protocol and decision making schemes based on distribution of doses and beta heterogeneity concept for luminescence dating of sediments. Observations ... The study also compares the criteria for the selection of different age models that are used at present. The age of the alluvial sequence is now ...

  17. Driving licences and medical screening in old age: Review of literature and European licensing policies

    OpenAIRE

    Siren, Anu Kristiina; Haustein, Sonja

    2015-01-01

    Chronological age, per se, seems to be, in the case of mature drivers, only a weak predictor of safe driving performance. However, screening policies based on chronological age are widely used. Nevertheless, lately, more evidence-based policies have been called for. In this paper we first, investigate the evidence for and against having an age-based driver screening policy in place; second, we map and compare the current driving licensing policies in European Union (EU) member states in order...

  18. Can aging be programmed?

    DEFF Research Database (Denmark)

    Kowald, Axel; Kirkwood, Thomas B. L.

    2016-01-01

    of unavoidable environmental risks. This forms the basis of the mainstream view that aging arises as a consequence of a declining selection pressure to maintain the physiological functioning of living beings forever. Over recent years, however, a number of articles have appeared that nevertheless propose......The evolution of the aging process has long been a biological riddle, because it is difficult to explain the evolution of a trait that has apparently no benefit to the individual. Over 60 years ago, Medawar realized that the force of natural selection declines with chronological age because...... the existence of specific aging genes; that is, that the aging process is genetically programmed. If this view were correct, it would have serious implications for experiments to understand and postpone aging. Therefore, we studied in detail various specific proposals why aging should be programmed. We find...

  19. [Epidemiological and chronological profile of the low birth weight in the region of Monastir (Tunisia) between 1994 and 2007].

    Science.gov (United States)

    El Mhamdi, S; Lifi, B; Bouanène, I; Hadded, A; Sriha, A; Letaief, M; Ben Salem, K; Soltani, M S

    2011-01-01

    In Tunisia, despite the activities of national programs of maternal and child health, low birth weight (LBW) remains common. The aim of this study is to draw up the epidemiological profile of the LBW in the region of Monastir and to study the chronological trends of the associated factors during a period of 14 years (1994-2007). We conducted a population study which interest 97.630 live births (from 26 to 43 weeks) in the public maternities of the region of Monastir. The mean's age of pregnant women was 28.7 +/- 5.5 years. Among them 14.2% were aged 35 and older and 40% were primipara. Newborns were in term in 94.7% of cases. Maternal age, prenatal care, twin pregnancies and fetal complications were the factors independently associated with the occurrence of LBW in term newborns. However, only prenatal care and twin pregnancies were independently associated to LBW in preterm newborns. During the fourteenth years of the study the parturient mean age and the frequency of preterm birth increased significantly (P < 0.001) while the frequency of multiparty decreased significantly (P < 0.001). We found that the risk factors of LBW (advanced age, multiparty, etc.) are still common in our country and require targeted interventions.

  20. Development of a modified prognostic index for patients with aggressive adult T-cell leukemia-lymphoma aged 70 years or younger: possible risk-adapted management strategies including allogeneic transplantation.

    Science.gov (United States)

    Fuji, Shigeo; Yamaguchi, Takuhiro; Inoue, Yoshitaka; Utsunomiya, Atae; Moriuchi, Yukiyoshi; Uchimaru, Kaoru; Owatari, Satsuki; Miyagi, Takashi; Taguchi, Jun; Choi, Ilseung; Otsuka, Eiichi; Nakachi, Sawako; Yamamoto, Hisashi; Kurosawa, Saiko; Tobinai, Kensei; Fukuda, Takahiro

    2017-07-01

    Adult T-cell leukemia-lymphoma is a distinct type of peripheral T-cell lymphoma caused by human T-cell lymphotropic virus type I. Although allogeneic stem cell transplantation after chemotherapy is a recommended treatment option for patients with aggressive adult T-cell leukemia-lymphoma, there is no consensus about indications for allogeneic stem cell transplantation because there is no established risk stratification system for transplant eligible patients. We conducted a nationwide survey of patients with aggressive adult T-cell leukemia-lymphoma in order to construct a new, large database that includes 1,792 patients aged 70 years or younger with aggressive adult T-cell leukemia-lymphoma who were diagnosed between 2000 and 2013 and received intensive first-line chemotherapy. We randomly divided patients into two groups (training and validation sets). Acute type, poor performance status, high soluble interleukin-2 receptor levels (> 5,000 U/mL), high adjusted calcium levels (≥ 12 mg/dL), and high C-reactive protein levels (≥ 2.5 mg/dL) were independent adverse prognostic factors used in the training set. We used these five variables to divide patients into three risk groups. In the validation set, median overall survival for the low-, intermediate-, and high-risk groups was 626 days, 322 days, and 197 days, respectively. In the intermediate- and high-risk groups, transplanted recipients had significantly better overall survival than non-transplanted patients. We developed a promising new risk stratification system to identify patients aged 70 years or younger with aggressive adult T-cell leukemia-lymphoma who may benefit from upfront allogeneic stem cell transplantation. Prospective studies are warranted to confirm the benefit of this treatment strategy. Copyright© 2017 Ferrata Storti Foundation.

  1. Optimization of arterial age prediction models based in pulse wave

    International Nuclear Information System (INIS)

    Scandurra, A G; Meschino, G J; Passoni, L I; Dai Pra, A L; Introzzi, A R; Clara, F M

    2007-01-01

    We propose the detection of early arterial ageing through a prediction model of arterial age based in the coherence assumption between the pulse wave morphology and the patient's chronological age. Whereas we evaluate several methods, a Sugeno fuzzy inference system is selected. Models optimization is approached using hybrid methods: parameter adaptation with Artificial Neural Networks and Genetic Algorithms. Features selection was performed according with their projection on main factors of the Principal Components Analysis. The model performance was tested using the bootstrap error type .632E. The model presented an error smaller than 8.5%. This result encourages including this process as a diagnosis module into the device for pulse analysis that has been developed by the Bioengineering Laboratory staff

  2. Optimization of arterial age prediction models based in pulse wave

    Energy Technology Data Exchange (ETDEWEB)

    Scandurra, A G [Bioengineering Laboratory, Electronic Department, Mar del Plata University (Argentina); Meschino, G J [Bioengineering Laboratory, Electronic Department, Mar del Plata University (Argentina); Passoni, L I [Bioengineering Laboratory, Electronic Department, Mar del Plata University (Argentina); Dai Pra, A L [Engineering Aplied Artificial Intelligence Group, Mathematics Department, Mar del Plata University (Argentina); Introzzi, A R [Bioengineering Laboratory, Electronic Department, Mar del Plata University (Argentina); Clara, F M [Bioengineering Laboratory, Electronic Department, Mar del Plata University (Argentina)

    2007-11-15

    We propose the detection of early arterial ageing through a prediction model of arterial age based in the coherence assumption between the pulse wave morphology and the patient's chronological age. Whereas we evaluate several methods, a Sugeno fuzzy inference system is selected. Models optimization is approached using hybrid methods: parameter adaptation with Artificial Neural Networks and Genetic Algorithms. Features selection was performed according with their projection on main factors of the Principal Components Analysis. The model performance was tested using the bootstrap error type .632E. The model presented an error smaller than 8.5%. This result encourages including this process as a diagnosis module into the device for pulse analysis that has been developed by the Bioengineering Laboratory staff.

  3. Maintained memory in aging is associated with young epigenetic age.

    Science.gov (United States)

    Degerman, Sofie; Josefsson, Maria; Nordin Adolfsson, Annelie; Wennstedt, Sigrid; Landfors, Mattias; Haider, Zahra; Pudas, Sara; Hultdin, Magnus; Nyberg, Lars; Adolfsson, Rolf

    2017-07-01

    Epigenetic alterations during aging have been proposed to contribute to decline in physical and cognitive functions, and accelerated epigenetic aging has been associated with disease and all-cause mortality later in life. In this study, we estimated epigenetic age dynamics in groups with different memory trajectories (maintained high performance, average decline, and accelerated decline) over a 15-year period. Epigenetic (DNA-methylation [DNAm]) age was assessed, and delta age (DNAm age - chronological age) was calculated in blood samples at baseline (age: 55-65 years) and 15 years later in 52 age- and gender-matched individuals from the Betula study in Sweden. A lower delta DNAm age was observed for those with maintained memory functions compared with those with average (p = 0.035) or accelerated decline (p = 0.037). Moreover, separate analyses revealed that DNAm age at follow-up, but not chronologic age, was a significant predictor of dementia (p = 0.019). Our findings suggest that young epigenetic age contributes to maintained memory in aging. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. β-Hydroxybutyrate (BHB) and glucose concentrations in the blood of dairy calves as influenced by age, vaccination stress, weaning, and starter intake including evaluation of BHB and glucose markers of starter intake.

    Science.gov (United States)

    Suarez-Mena, F X; Hu, W; Dennis, T S; Hill, T M; Schlotterbeck, R L

    2017-04-01

    The objective of this research was to determine how blood β-hydroxybutyrate (BHB) and glucose are affected by age, time of day, stress, weaning, forced intake restriction, and voluntary starter intake in calves between 1 and 9 wk of age, and to evaluate if either is an acceptable proxy for starter intake. Holstein calves were fed a 27% crude protein, 17% fat milk replacer at 660 g of dry matter daily along with free-choice starter and water. Calves were weaned on d 42. Jugular blood was sampled at 0800, 1200, and 1600 h, and within 5 min of sampling BHB, and glucose concentrations were estimated using test strips (Nova Max Plus meter, Nova Biomedical Corporation, Waltham, MA). Age effects and time of day were estimated by sampling blood weekly (d 6, 13, 20, 27, 34, 41, and 48). To determine vaccination stress, a Pasteurella vaccine was administered after blood sampling at 0800 h on d 36. Effect of voluntary starter intake was tested by selecting calves for low and high intakes (d 35 to 39) and sampling on d 40, 41, 43, and 44. Starter intake restriction was tested by restricting intake in half of the calves and sampling on d 60 and 61. Data were analyzed with repeated measurements in a mixed model procedure with either within-calf effect (day or week) or within-calf effects (hour, and day or week) included in the model. Time of day did not affect blood BHB and glucose in the first 6 wk. Blood BHB was greater in wk 7 versus wk 1 to 6. Blood glucose was greater in the first 5 wk compared with wk 6 and 7. Blood BHB increased and glucose decreased with increasing starter intake. Blood BHB declined due to vaccination, but glucose was unaffected. Starter intake restriction reduced BHB for 3 d and glucose for 2 d after restriction. Both were affected by time of day. Around weaning (d 40 to 44), BHB and glucose increased with increasing starter intake. In this research, neither blood BHB nor glucose was a good proxy for starter intake. Blood BHB was positively and glucose

  5. The role of phosphates for the Lu-Hf chronology of meteorites

    Science.gov (United States)

    Debaille, Vinciane; Van Orman, James; Yin, Qing-Zhu; Amelin, Yuri

    2017-09-01

    The 176Lu-176Hf isotopic system is widely used for dating and tracing cosmochemical and geological processes, but still suffers from two uncertainties. First, Lu-Hf isochrons for some early Solar System materials have excess slope of unknown origin that should not be expected for meteorites with ages precisely determined with other isotopic chronometers. This observation translates to an apparent Lu decay constant higher than the one calculated by comparing ages obtained with various dating methods on terrestrial samples. Second, unlike the well constrained Sm/Nd value (to within 2%) for the chondritic uniform reservoir (CHUR), the Lu/Hf ratios in chondrites vary up to 18% when considering all chondrites, adding uncertainty to the Lu/Hf CHUR value. In order to better understand the Lu-Hf systematics of chondrites, we analyzed mineral fractions from the Richardton H5 chondrite to construct an internal Lu-Hf isochron, and set up a numerical model to investigate the effect of preferential diffusion of Lu compared to Hf from phosphate, the phase with the highest Lu-Hf ratio in chondrites, to other minerals. The isochron yields an age of 4647 ± 210 million years (Myr) using the accepted 176Lu decay constant of 1.867 ± 0.008 ×10-11yr-1. Combining this study with the phosphate fractions measured in a previous study yields a slope of 0.08855 ± 0.00072, translating to a 176Lu decay constant of 1.862 ± 0.016 ×10-11yr-1 using the Pb-Pb age previously obtained, in agreement with the accepted value. The large variation of the Lu/Hf phosphates combined with observations in the present study identify phosphates as the key in perturbing Lu-Hf dating and generating the isochron slope discrepancy. This is critical as apatite has substantially higher diffusion rates of rare earth elements than most silicate minerals that comprise stony meteorites. Results of numerical modeling depending of temperature peak, size of the grains and duration of the metamorphic event, show that

  6. Medicine through the ages.

    Science.gov (United States)

    Majumdar, S K

    1994-01-01

    History of medicine chronologically traces its development from guesswork about the actions of prehistoric man through the centuries to some aspects of the present day. The intellectual and cultural centres of the world have moved over time to time from place to place. In earlier times all knowledge was part of a conglomerate which one polymath might be able to master in a way no longer open to anyone now. The history of medicine through the ages has been presented here under different subdivisions, such as The Past, The Middle Ages, The Twelfth century Renaissance and Medicine and the Renaissance (Newton's century) etc.

  7. Fission track dating: methodology and thermo-chronological applications in alpine and continental margin contexts

    International Nuclear Information System (INIS)

    Sabil, N.

    1995-06-01

    The fission track dating method has proved to be unique in thermo-chronology by its capability to describe the final phases of the cooling history and denudation of metamorphic massifs, like the thermal history of sedimentary formations or the dating of some volcanic materials. In this work we describe this method and present a series of new analytic techniques and calibrations which we realised in the aim of further use in geology. We discuss a few examples of such applications. In the french Occidental Alps, the analysis of fission track on apatite samples from the granites of the Sept Laux (Belledonne massif), in the Eau d' Olle valley, suggests that this method could bring a contribution to the actual discussion about the origin of some alpine valleys. The fission track method suggests that the opening of this valley could be the consequence of an active faulting from the middle Miocene until the present. The characterization of fluvial deposits through their detrital apatites fission tracks record could eventually be used to study river captures related to changes tectonic regimes. Therefore we studied the apatites of a paleo-delta located in the Isere middle valley at the sub-alpine 'sillon' level, and of two valleys, those of the Arc and of the Breda, located up the delta. The distribution of the fission track ages of those mineraIs has not confirmed a previously suggested model, which proposed that the studied paleo-delta could be associated with a paleo-Arc rather than a paleo-Breda. In the Moroccan Occidental Meseta, three granitic massifs located in the Rehamna have been selected for a thermo-chronological study. The analysis of the fission track in zircons and apatites of these granites recorded the thermo-tectonic events which have affected the Meseta ever since the opening of the Central Atlantic Ocean some 200 Ma ago. We show how a numerical simulation model recently (1994) proposed for the analysis of fission track in apatites allows us to specify

  8. Antarctic Glacial Chronology: New Constraints from Surface Exposure Dating

    National Research Council Canada - National Science Library

    Ackert, Robert

    2000-01-01

    .... New He-3 production rates are determined from a 125 ka lava flow. Measurements of inherited He-3/He-4 in two common Antarctic lithologies allow measurement of exposure ages < 6000 years. At Mt...

  9. Comparison of the accuracy of the London atlas and Smith method in dental age estimation in 5-15.99-year-old Iranians using the panoramic view.

    Science.gov (United States)

    Ghafari, Roshanak; Ghodousi, Arash; Poordavar, Esmaeil

    2018-03-07

    Tooth development is widely used for age estimation and staging physical maturity. It is of great importance in dental age estimation in forensic dentistry, orthodontic treatment planning, and pediatric endocrinology. This study aimed to compare the accuracy of two age estimation methods, i.e., the London Atlas and Smith's method, using the panoramic view of developing teeth. In this descriptive-analytic study, panoramic radiographs of 339 healthy individuals, including 145 boys and 194 girls, were assessed. The participants aged between 5.00 and 15.99 years. Dental age of the subjects was determined by the London Atlas of Human Tooth Development and Eruption and Smith's method. The collected information was entered in the SPSS software (Ver.18). Differences and correlations between chronological and dental age were assessed by paired t tests and Pearson's correlation analysis. In all analyzes, the significance level was considered less than 0.05. The mean chronological age of the subjects was 10.13 ± 2.92 years. The mean ages estimated by the London Atlas and Smith's method were 10.29 ± 2.91 and 9.89 ± 2.84 years, respectively. Paired t test showed that the differences between the mean chronological age and mean estimated ages using the London Atlas and Smith's method were not significant (P = 0.15 and 0.16, respectively). Our findings showed that both methods had high accuracy for age estimation, but the London Atlas is easier to use.

  10. Glacio-Karstic and chronological evolution of the Akdaǧ rockslide (SW Turkey)

    Science.gov (United States)

    Bayrakdar, Cihan; Akçar, Naki; Gorum, Tolga; Ivy-Ochs, Susan; Vockenhuber, Christof

    2015-04-01

    Landslides triggered by bedrock failures are one of the main geohazards in the high mountain areas. They constitute some of the largest landslide deposits on the Earth. This study focuses on the geomorphological evolution of the Akdag rockslide which is located on the southern slope of the Mount Akdag, SW Turkey. The Akdag Massif is characterized by autochthonous carbonates and shales overridden by allochthonous Jurassic-Cretaceous carbonates. Akdag was glaciated at least three times during the Late Pleistocene. There are large karstic depressions developed in these glaciated areas. These karstic depressions are underlain by impermeable flysch deposits. Karstic springs are located along the contact between the flysch and overlying carbonates. This contact seems to be the major failure plane of most mass movements in the massive.Our field mapping shows that the Akdag rockslide is a very large and active slope failure developed between the carbonates and the flysch. Its deposit covers an area of 15 km2 and have a volume of about 7 km3. It is one of the largest (>106 m3) landslides in Turkey. Settlements and their infrastructure have been severely damaged due to this activity. In this study, we employed detailed mapping in the field, spatial and morphometric analysis using GIS and remote sensing technologies, and surface exposure dating with cosmogenic 36Cl in order to reconstruct the chronology of the landslide. For the analysis of cosmogenic 36Cl, we collected 18 samples from calcareous boulders within the landslide deposit. Cosmogenic 36Cl exposure ages indicate that the collapse occurred at around 9 ka. Based on the field evidence, we anticipate that the increased water discharge in the springs along the carbonate-flysch contact could played a key role in the failure in the Early Holocene.

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

    Directory of Open Access Journals (Sweden)

    Orozco Helena

    2012-08-01

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

  12. How age matters : Exploring contemporary Dutch debates on age and sex work

    NARCIS (Netherlands)

    S.V. Coumans (Sara Vida)

    2014-01-01

    textabstractSocial protection policies regarding sex work in The Netherlands use ‘age’ as an instrument to create binaries between adults and young people. The concept ‘chronological age’ assumes that age is a static feature and supports the process of categorization; however, age is a socially

  13. Chronological constraints on the Paleoproterozoic Francevillian Group in Gabon

    Directory of Open Access Journals (Sweden)

    Yusuke Sawaki

    2017-03-01

    Full Text Available The Francevillian Group in Gabonese Republic was recently established as a typical sedimentary sequence for the Paleoproterozoic. However, its age is rather poorly constrained, mainly based on Rb-Sr and Nd-Sm datings. This study reports new zircon data obtained from Chaillu massif and N'goutou complex, which constrain the protolith age of the basement orthogneisses and the igneous age of an intrusive granite, respectively. Most zircons from the orthogneisses are blue and exhibit oscillatory zoning in cathode-luminescence images. Zircons with lower common lead abundances tend to be distributed close to the concordia curve. Two age clusters around 2860 Ma and 2910 Ma are found in zircons plotted on the concordia curve. Based on the Th/U ratios of zircons, these ages correspond to the protolith ages of the orthogneisses, and the zircons are not metamorphic in origin. Syenites and granites were collected from the N'goutou complex that intrudes into the FA and FB units of the Francevillian Group. The granitoids exhibit chemical composition of A-type granite affinity. Half of zircons separated from the granite are non-luminous, and the remaining half exhibit obscure internal textures under cathode-luminescence observation. All zircon grains contain significant amounts of common lead; the lead isotopic variability is probably attributed to the mixing of two components in the zircons. The zircon radiogenic 207Pb/206Pb ratio is 0.13707 ± 0.0010, corresponding to a 207Pb/206Pb age of 2191 ± 13 Ma. This constrains the minimum depositional age of the FA and FB units. Furthermore, the FB unit consists of manganese-rich carbonate rocks and organic carbon-rich black shales with macroscopic fossils. Based on our age constraints, these organisms appeared in the study area just after the last Paleoproterozoic Snowball Earth event, in concert with global scale oxidation event encompassing the Snowball Earth.

  14. Analysis of 1202 orthopantograms to evaluate the potential of forensic age determination based on third molar developmental stages.

    Science.gov (United States)

    Willershausen, B; Löffler, N; Schulze, R

    2001-09-28

    A total of 1202 orthopantograms of young dental patients were analyzed to assess the correlation of third molar root development with chronological age. The investigated patients were treated at a university dental clinic on an outpatient basis, included a variety of demographic characteristics (600 males and 602 females, 28% of other than central European background), and were 15-24 years old when the radiographs were obtained. Radiographs in which more than one third molar were either missing due to agenesia or extraction, or not evaluable because of deep destruction or marked tilting, were not included in the analysis. Our findings show that the growth patterns of third molars, based on seven defined stages of root development, did correlate with chronological age; age estimation when applied to a specific individual would involve a margin of error of +/- 2-4 years. There were no significant differences between the left and right jaw segments, but the stage of root development was generally more advanced in the upper than in the lower third molars. Root development was also more advanced among boys than among girls of the same age. There were no apparent differences in growth patterns based on national/ethnic background. While only 2.5% of 18-year-olds revealed fully developed third molars in all four quadrants, this percentage leaped to 38.4% among the 21-year-olds. To summarize, while the developmental stage of third molars is not per se a highly useful indicator of chronological age in juveniles and young adults, it is nevertheless a valuable supplementary parameter given the scarcity of other available age indicators.

  15. High-precision chronology for Central American maize diversification from El Gigante rockshelter, Honduras.

    Science.gov (United States)

    Kennett, Douglas J; Thakar, Heather B; VanDerwarker, Amber M; Webster, David L; Culleton, Brendan J; Harper, Thomas K; Kistler, Logan; Scheffler, Timothy E; Hirth, Kenneth

    2017-08-22

    The first steps toward maize ( Zea mays subspecies mays ) domestication occurred in the Balsas region of Mexico by ∼9,000 calendar years B.P. (cal B.P.), but it remains unclear when maize was productive enough to be a staple grain in the Americas. Molecular and microbotanical data provide a partial picture of the timing and nature of morphological change, with genetic data indicating that alleles for some domestication traits were not yet fixed by 5,300 cal B.P. in the highlands of Mexico. Here, we report 88 radiocarbon dates on the botanical remains from El Gigante rockshelter (Honduras) to establish a Bayesian chronology over the past ∼11,000 y spanning the transition to maize-based food production. Botanical remains are remarkably well preserved and include over 10,000 maize macrofossils. We directly dated 37 maize cobs to establish the appearance and local change of maize at the site. Cobs are common in deposits dating between 4,340 and 4,020 cal B.P., and again between 2,350 and 980 cal B.P. The earliest cobs appear robustly domesticated, having 10-14 rows, suggesting strong selection for increased yield. The later cobs are comparable to these earliest ones, but show clear emergence of diverse traits, including increased cob width, rachis segment length, and cupule width. Our results indicate that domesticated landraces of maize productive enough to be a staple grain existed in Central America by 4,300 cal B.P.

  16. Chronology of Chichen Izta, evidences by thermoluminescence; Cronologia de Chichen Izta, evidencias por termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A.; Schaaf, P. [Laboratorio de Termoluminiscencia, Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico); Gonzalez, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Chung, H. [Facultad de Filosofia y Letras, UNAM, 04510 Mexico D.F. (Mexico)

    2002-07-01

    The establishment of the chronology of Chichen Itza is argued by its stylistic evocations, architectural and iconographical as well as its history related in the sources, as the Chilam Balam, where is named the arrival of foreign tribes as the Xiu and the Itzaes and its settlement in Chichen Itza as well as the return to its origin place. The material evidence of such transition is reflected in the ceramic change of the Pizarra Puuc to the Pizarra Chichen, however, in 13 stratigraphic wells realized in different points of Chichen Itza, it was not found evidence of the layer of the Pizarra Puuc period. In this work the obtained ages of dating by thermoluminescence (TL) are presented, of four samples of ceramics found in the different wells. When our results are compared with the estimated ages for the different groups of ceramics, it was observed that none of they corresponded to the Pizarra Puuc period. These results strenghten the observations realized during excavations, causing the suggestion of new inferences related to the Chichen Itza boom and its relationship with the Maya Classic Period. The used technique for the TL dating was that of fine grain. The interval of artificial dose, of beta radiation of Strontium 90 was between 2 and 30 Gy. The TL signal was obtained heating the samples at 10 C/s until reaching 500 C in the TL Daybreak reader equipment. In order to know the annual dose rate of concentration of potassium ({sup 40} K) by means of the microanalysis technique in the scanning electron microscope was determined, while the uranium content (2{sup 38} U) and thorium ({sup 232} Th) were determined by means of the neutron activation analysis technique using the TRIGA Mark III nuclear reactor. The contribution of the gamma radiation of the soil as well as the contribution of the cosmic radiation was measured with TL dosemeters of CaSO{sub 4} :Dy + Ptfe once the paleodose was known and the annual dose rate of each sample of its age was estimated. (Author)

  17. Attitudes Towards Ads and Age: A Study in Seniors

    Directory of Open Access Journals (Sweden)

    Marta M. Estrada

    2014-08-01

    Full Text Available Older adults make up one of the markets with the greatest potential in the future. It is essential that businesses take the diversity within this group into account, and perform segmentation in order to obtain a favorable attitude towards the ad. The potential for segmentation by chronological age has been called into question in recent years, with cognitive age emerging as the main alternative. This research aims to analyses the relationship between the variables of attitude towards the ad, attitude towards the brand and purchasing intention among older adults, noting the moderating effect of the joint use of chronological age and cognitive age on these items. 

  18. Precipitation reconstruction using ring-width chronology of ...

    Indian Academy of Sciences (India)

    ... whole of the `Little Ice Age' and latter part of the `Medieval Warm Period'. The reconstruction revealed the wettest and the driest non-monsoon months during the fourteenth and the thirteenth centuries, respectively. The seventeenth century consistently recorded dry non-monsoon months in the western Himalayan region.

  19. Aging in a Total Institution: The Case of Older Prisoners.

    Science.gov (United States)

    Reed, Monika B.; Glamser, Francis D.

    1979-01-01

    Interviews with older prisoners at a major state penitentiary were conducted to better understand the impact of social arrangements on aging. Normal aging does not take place in the prison setting. Chronological age does not possess much salience for prisoners, and some effects of environmental stress on appearance are mitigated. (Author)

  20. Breeding chronology and reproductive success of Richardson's merlins in southeastern Montana

    Science.gov (United States)

    Dale M. Becker; Carolyn Hull Sieg

    1985-01-01

    Breeding chronology and reproductive success of the Merlin (Falco columbarius richarsonii) were studied in southeastern Montana from 1978 - 1981. Breeding activity spanned 5 mo from the earliest observation of adults to the latest dispersal of adults and young from nesting areas. Clutch size, brood size and fledging success at active nests were...

  1. 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

  2. Testing competing hypotheses for chronology and intensity of lesser scaup molt during winter and spring migration

    Science.gov (United States)

    Anteau, M.J.; Anteau, A.C.E.; Afton, A.D.

    2011-01-01

    We examined chronology and intensity of molt and their relationships to nutrient reserves (lipid and protein) of Lesser Scaup (Aythya affinis) to test predictions of two competing hypotheses. The "staggered cost" hypothesis states that contour-feather molt is nutritionally costly and should not occur during nutritionally costly periods of the annual cycle unless adequate nutrients are available. The "breeding plumage" hypothesis states that prealternate molt must be complete prior to nesting, regardless of nutrient availability. Males and females were completing prebasic molt during winter (Louisiana) and had similar molt intensities. Females underwent prealternate molt during spring migration (Illinois and Minnesota) and prebreeding (Manitoba) periods; 53% and 93% of females were in moderate to heavy molt in Minnesota and Manitoba, respectively, despite experiencing other substantial nutritional costs. Intensity of prealternate molt was not correlated with lipid reserves even though females, on average, were nutritionally stressed. Molt intensity was not negatively correlated with protein reserves at any location. Chronology and intensity of prealternate molt varied little and were not temporally staggered from other nutritionally costly events. Prealternate molt did not influence nutrient reserves, and nutrient reserves likely were not the ultimate factor influencing chronology or intensity of prealternate molt of females. We surmise that nutrients required for prealternate molt come from exogenous sources and that the "staggered cost" hypothesis does not explain chronology of prealternate molt in female Lesser Scaup; rather, it appears that molt must be complete prior to nesting, consistent with the "breeding plumage" hypothesis. ?? The Cooper Ornithological Society 2011.

  3. Climatic events and Upper Paleolithic chronology in the Dniester basin : New C-14 results from Cosautsi

    NARCIS (Netherlands)

    Haesaerts, P; Borziak, [No Value; Van Der Plicht, J; Damblon, F; Borziak, Ilic; Mook, W.G.

    1998-01-01

    We discuss the radiocarbon chronology of the loess deposited during the Upper Pleniglacial (Isotope Stage II) for the key site of Cosautsi (Republic of Moldova), which presents some major problems in C-14 dating. Special care was paid to accurate microstratigraphic positioning of samples, collection

  4. Chronology of the 1st–2nd Century Graves from the Tarasovo Burial Ground

    Directory of Open Access Journals (Sweden)

    Goldina Rimma D.

    2016-03-01

    Full Text Available The article focuses on the chronology of graves dating back to the early (1st – 2nd centuries AD – Nyrgynda stage of the 1st – 5th century Tarasovo burial ground, a classical monument attributed to the Cheganda culture of the Pyany Bor cultural-historical community. Cultural stratigraphy is applied as a research method. Artifacts from the early stage were correlated for 37 male and 102 female complexes, separately. The analysis of grave goods from male burials showed the following three chronological groups, that can be distinguished at the Nyrgynda stage: 1st century (group 1, 2nd century (group 2 and 1st – 2nd centuries AD (group 3. The goods from female graves are more representative and various, so three more groups with shorter chronological lives can be singled out: the fi rst half of the 2nd century (group 2а, the second half of the 2nd century (group 2б and the 1st – fi rst half of the 2nd century (group 4. Certainly, the suggested chronology leaves room for any eventual corrections subject to new findings.

  5. Chronological enumeration of nominal species and subspecies of Corydoras (Pisces, Siluriformes, Callichthyidae)

    NARCIS (Netherlands)

    Nijssen, H.; Isbrücker, I.J.H.

    1979-01-01

    A complete list of species and subspecies accepted as members of the genus Corydoras Lacépède, 1803, is given. They are arranged in chronological order. Invalid specific names are followed by their senior synonym. Nomina nuda are listed separately. A bibliography covering all publications containing

  6. An Old Fad of Great Promise: Reverse Chronology History Teaching in Social Studies Classes

    Science.gov (United States)

    Misco, Thomas; Patterson, Nancy C.

    2009-01-01

    This article revisits and explores the promises and challenges of reverse chronology history instruction within the social studies. In response to student disinterest in social studies, changes in our educational culture that often value content knowledge exclusively, and marginalization of instructional time stemming from testing burdens, reverse…

  7. Considerations on the Chronology of the Tempietto sul Clitunno

    Directory of Open Access Journals (Sweden)

    Gianfranco Binazzi

    2015-03-01

    Full Text Available Dating the Tempietto sul Clitunno is still a subject of controversy, although so many studies have be-en made during the last two centuries and above all in the last few years. Some authors in 18th and 19th cen-turies thought the Tempietto was a “pagan” sacellum from the beginning and only successively transformed to serve christian functions; other authors, on the contrary, are of the opinion that the foundations of the building were laid in the early christian age; some other authors date it to the early medieval age and think it represents an important monument belonging to the longobard architecture of the Duchy of Spoleto.

  8. Diffusion models in metamorphic thermo chronology: philosophy and methods

    International Nuclear Information System (INIS)

    Munha, Jose Manuel; Tassinari, Colombo Celso Gaeta

    1999-01-01

    Understanding kinetics of diffusion is of major importance to the interpretation of isotopic ages in metamorphic rocks. This paper provides a review of concepts and methodologies involved on the various diffusion models that can be applied to radiogenic systems in cooling rocks. The central concept of closure temperature is critically discussed and quantitative estimates for the various diffusion models are evaluated, in order to illustrate the controlling factors and the limits of their practical application. (author)

  9. Understanding the Chronology and Occupation Dynamics of Oversized Pit Houses in the Southern Brazilian Highlands

    Science.gov (United States)

    Gregorio de Souza, Jonas; Robinson, Mark; Corteletti, Rafael; Cárdenas, Macarena Lucia; Wolf, Sidnei; Iriarte, José; Mayle, Francis; DeBlasis, Paulo

    2016-01-01

    A long held view about the occupation of southern proto-Jê pit house villages of the southern Brazilian highlands is that these sites represent cycles of long-term abandonment and reoccupation. However, this assumption is based on an insufficient number of radiocarbon dates for individual pit houses. To address this problem, we conducted a programme of comprehensive AMS radiocarbon dating and Bayesian modelling at the deeply stratified oversized pit House 1, Baggio I site (Cal. A.D. 1395–1650), Campo Belo do Sul, Santa Catarina state, Brazil. The stratigraphy of House 1 revealed an unparalleled sequence of twelve well preserved floors evidencing a major change in occupation dynamics including five completely burnt collapsed roofs. The results of the radiocarbon dating allowed us to understand for the first time the occupation dynamics of an oversized pit house in the southern Brazilian highlands. The Bayesian model demonstrates that House 1 was occupied for over two centuries with no evidence of major periods of abandonment, calling into question previous models of long-term abandonment. In addition, the House 1 sequence allowed us to tie transformations in ceramic style and lithic technology to an absolute chronology. Finally, we can provide new evidence that the emergence of oversized domestic structures is a relatively recent phenomenon among the southern proto-Jê. As monumental pit houses start to be built, small pit houses continue to be inhabited, evidencing emerging disparities in domestic architecture after AD 1000. Our research shows the importance of programmes of intensive dating of individual structures to understand occupation dynamics and site permanence, and challenges long held assumptions that the southern Brazilian highlands were home to marginal cultures in the context of lowland South America. PMID:27384341

  10. Chronological Review on Scientific Findings of Bonghan System and Primo Vascular System.

    Science.gov (United States)

    Kang, Kyung A

    In 1962, Bonghan Kim in North Korea published a report on a new vascular system in mammals, which he claimed as the acupuncture meridian. He soon named it the Bonghan System. Between 1962 and 1965, he published five reports, with detailed descriptions on the system. Kim also described the self-regenerating nature of a unique cell type Sanals in the system and these cells are now confirmed to be a type of stem cells. According to his findings, the system appears to have vital roles in maintaining mammalian lives. Kim disappeared in around 1965 and the research on this system also completely stopped. In 2002, Kwang-Sup Soh reported re-discovery of the system and, since then, his team has been leading the research on the system. The Soh team has confirmed many of Kim's findings to be valid, although so many of Kim's results are still to be verified. In 2010, the system was renamed the Primo Vascular System (PVS). Soh and researchers trained by Soh have also been reporting new scientific facts on the system. The PVS exists throughout the entire body, including inside the blood and lymphatic vessels. Recent reports revealed more evidence for it to be the acupuncture meridian, where some acupuncture therapies are applied for the blood pressure control. Thus, the PVS is expected to have roles in the oxygen transport in tissues. Many study results also suggest that the PVS may have roles in body homeostasis and regeneration. This article chronologically reviews Kim's scientific findings on the Bonghan System, which were verified by the PVS scientists (after 2000), and also the new findings reported by the PVS scientists.

  11. Chronological changes in Japanese physicians' attitude and behavior concerning relationships with pharmaceutical representatives: a qualitative study.

    Directory of Open Access Journals (Sweden)

    Sayaka Saito

    Full Text Available BACKGROUND: Recent qualitative studies indicated that physicians interact with pharmaceutical representatives depending on the relative weight of the benefits to the risks and are also influenced by a variety of experiences and circumstances. However, these studies do not provide enough information about if, when, how and why their attitudes and behaviors change over time. METHODS AND FINDINGS: A qualitative study using semi-structured face-to-face individual interviews was conducted on 9 Japanese physicians who attended a symposium on conflicts of interest held in Tokyo. Interviews were designed to explore chronological changes in individual physicians' attitude and behavior concerning relationships with pharmaceutical representatives and factors affecting such changes. Their early interaction with pharmaceutical representatives was passive as physicians were not explicitly aware of the meaning of such interaction. They began to think on their own about how to interact with pharmaceutical representatives as they progressed in their careers. Their attitude toward pharmaceutical representatives changed over time. Factors affecting attitudinal change included work environment (local regulations and job position, role models, views of patients and the public, acquisition of skills in information seeking and evidence-based medicine, and learning about the concepts of professionalism and conflict of interest. However, the change in attitude was not necessarily followed by behavioral change, apparently due to rationalization and conformity to social norms. CONCLUSIONS: Physicians' attitudes toward relationships with pharmaceutical representatives changed over time and factors affecting such changes were various. Paying attention to these factors and creating new social norms may be both necessary to produce change in behavior consistent with change in attitude.

  12. A genetic chronology for the Indian Subcontinent points to heavily sex-biased dispersals.

    Science.gov (United States)

    Silva, Marina; Oliveira, Marisa; Vieira, Daniel; Brandão, Andreia; Rito, Teresa; Pereira, Joana B; Fraser, Ross M; Hudson, Bob; Gandini, Francesca; Edwards, Ceiridwen; Pala, Maria; Koch, John; Wilson, James F; Pereira, Luísa; Richards, Martin B; Soares, Pedro

    2017-03-23

    India is a patchwork of tribal and non-tribal populations that speak many different languages from various language families. Indo-European, spoken across northern and central India, and also in Pakistan and Bangladesh, has been frequently connected to the so-called "Indo-Aryan invasions" from Central Asia ~3.5 ka and the establishment of the caste system, but the extent of immigration at this time remains extremely controversial. South India, on the other hand, is dominated by Dravidian languages. India displays a high level of endogamy due to its strict social boundaries, and high genetic drift as a result of long-term isolation which, together with a very complex history, makes the genetic study of Indian populations challenging. We have combined a detailed, high-resolution mitogenome analysis with summaries of autosomal data and Y-chromosome lineages to establish a settlement chronology for the Indian Subcontinent. Maternal lineages document the earliest settlement ~55-65 ka (thousand years ago), and major population shifts in the later Pleistocene that explain previous dating discrepancies and neutrality violation. Whilst current genome-wide analyses conflate all dispersals from Southwest and Central Asia, we were able to tease out from the mitogenome data distinct dispersal episodes dating from between the Last Glacial Maximum to the Bronze Age. Moreover, we found an extremely marked sex bias by comparing the different genetic systems. Maternal lineages primarily reflect earlier, pre-Holocene processes, and paternal lineages predominantly episodes within the last 10 ka. In particular, genetic influx from Central Asia in the Bronze Age was strongly male-driven, consistent with the patriarchal, patrilocal and patrilineal social structure attributed to the inferred pastoralist early Indo-European society. This was part of a much wider process of Indo-European expansion, with an ultimate source in the Pontic-Caspian region, which carried closely related Y

  13. Chronological constraints on tectonic evolution of the Chinese Tianshan Orogen through detrital zircons from modern and paleo-river sands

    Science.gov (United States)

    Ren, Rong; Guan, Shuwei; Han, Baofu

    2017-04-01

    The Chinese Tianshan Orogen marked the prolonged, complicated interactions between the southwestern Paleo-Asian Ocean and surrounding blocks. Massive new and previous detrital zircon U-Pb chronological data from modern and paleo-river sands (more than 7000 ages from 102 samples) were compiled to constrain its tectonic evolution. The Chinese Tianshan Orogen is characterized by predominant Paleozoic and minor Mesozoic and Precambrian detrital zircon ages that show multimodal characteristic. The oldest Phanerozoic zircon population (peak at 475 Ma) results from subduction and closure of the Early Paleozoic Terskey Ocean. But the absence of this peak in Chinese North and southern South Tianshan suggests that the subductions of the North and South Tianshan oceans may not initiate until Late Ordovician, with subsequent 460-390 Ma and 360-320 Ma arc magmatism. Similar to magmatic suite in classic collisional orogens, the youngest massive 320-270 Ma magmatism is supposed to be post-collisional. The North and South Tianshan oceans therefore probably had their closure to form the Chinese Tianshan Orogen during Late Carboniferous. The weak Mesozoic intra-plate magmatism further argues against a Late Permian-Triassic Tianshan Orogen for the lack of extensive syn- and post-collisional magmatism. Moreover, the diverse Precambrian detrital zircon age patterns indicate that the surrounding blocks have distinct tectonic evolution and short-term amalgamation during the Neoproterozoic.

  14. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol 11, No. 1 through Vol. 16, No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1976-04-01

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970) through Vol. 16, No. 6 (Nov.-Dec. 1975). Included in the index is a chronological list of articles (including abstract) followed by both a KWIC index and an Author Index. Nuclear Safety is a bimonthly technical progress review prepared by the Nuclear Safety Information Center and covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 300 technical articles in the last six years of publication.

  15. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol 11, No. 1 through Vol. 16, No. 6

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Klein, A.

    1976-04-01

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970) through Vol. 16, No. 6 (Nov.-Dec. 1975). Included in the index is a chronological list of articles (including abstract) followed by both a KWIC index and an Author Index. Nuclear Safety is a bimonthly technical progress review prepared by the Nuclear Safety Information Center and covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 300 technical articles in the last six years of publication

  16. Preliminary study of the chronology of the sedimentation process in lakes

    International Nuclear Information System (INIS)

    Patrocinio Junior, Antonio C.; Andrello, Avacir C.

    2009-01-01

    The soil erosion accelerated which produces the presence of sediment in rivers is one of the main environmental problems and represents a challenge for the sustainable use of soil and water resources. The problems associated with the increased sediments production are mainly related to the rivers siltation, reduced storage capacity of dams and reservoirs and reduction in the quality of aquatic environment. Thus, further information on sedimentation rates in lakes and reservoirs are required, as a parameter for estimating the chronology of production rates of sediment. Therefore, methods to establish the chronology of recent sediments are central base for such research. The cesium-137 is an artificial radionuclide with a half life of 30.2 years, inserted in the environment through the 'fallout' radioactive between the 1950's and 1970's, with two predominant peaks of deposition in 1959 and 1964. The basis for using the cesium-137 in this context (chronology of sediments) is that the cesium-137 is rapidly and strongly adsorbed to fine particles of soil and its distribution in the sediment profile directly reflects the chronology of sediment deposition. The purpose of this work is to use the cesium-137 profile in lake sediments to assess the history of deposition and to obtain information about the erosive process. For this, lake sediments of a mini-hydroelectric power plant built in the 1940's in the city of Londrina-PR were analyzed, showing that cesium-137 can be used as a source of data for chronological assessment of erosive processes occurring in the vicinity of the lake. (author)

  17. Preliminary study of the chronology of the sedimentation process in lakes

    Energy Technology Data Exchange (ETDEWEB)

    Patrocinio Junior, Antonio C.; Andrello, Avacir C., E-mail: juninhoska@hotmail.co, E-mail: acandrello@uel.b [Universidade Estadual de Londrina, PR (Brazil). Dept. de Fisica

    2009-07-01

    The soil erosion accelerated which produces the presence of sediment in rivers is one of the main environmental problems and represents a challenge for the sustainable use of soil and water resources. The problems associated with the increased sediments production are mainly related to the rivers siltation, reduced storage capacity of dams and reservoirs and reduction in the quality of aquatic environment. Thus, further information on sedimentation rates in lakes and reservoirs are required, as a parameter for estimating the chronology of production rates of sediment. Therefore, methods to establish the chronology of recent sediments are central base for such research. The cesium-137 is an artificial radionuclide with a half life of 30.2 years, inserted in the environment through the 'fallout' radioactive between the 1950's and 1970's, with two predominant peaks of deposition in 1959 and 1964. The basis for using the cesium-137 in this context (chronology of sediments) is that the cesium-137 is rapidly and strongly adsorbed to fine particles of soil and its distribution in the sediment profile directly reflects the chronology of sediment deposition. The purpose of this work is to use the cesium-137 profile in lake sediments to assess the history of deposition and to obtain information about the erosive process. For this, lake sediments of a mini-hydroelectric power plant built in the 1940's in the city of Londrina-PR were analyzed, showing that cesium-137 can be used as a source of data for chronological assessment of erosive processes occurring in the vicinity of the lake. (author)

  18. 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

  19. The effects of socio-economic status and physical health on the long-term care needs of Japanese urban elderly: a chronological study.

    Science.gov (United States)

    Yang, Suwen; Hoshi, Tanji; Nakayama, Naoko; Wang, Shuo; Kong, Fanlei

    2013-01-01

    The aim of this chronological study was to elucidate the effects of socio-economic status (SES) and physical health on the long-term care (LTC) needs of a Japanese elderly population and to explore their causal relationships. A self-administered questionnaire was distributed to all residents aged 65 years and older of Tama City, Tokyo, in September 2001. A total of 13,195 completed questionnaires were returned, giving a response rate of 80.2 %. A follow-up study was done using the same questionnaire in 2004. Ultimately, 7,905 respondents were included in our analysis. Data analysis was performed using correlation analysis and structural equation modeling (SEM). For SEM, we used one observed variable (LTC needs in 2004) and three latent variables (SES in 2001 and physical health in both 2001 and 2004). The data were well fit by the models, with a NFI of 0.980, CFI of 0.982, and RMSEA of 0.032. LTC needs were well explained by the three latent variables (R (2) = 0.70 and 0.66 for elderly men and women, respectively). Among all variables, physical health in 2004 was the strongest determinant of LTC needs, followed by physical health in 2001, and SES in 2001. Gender differences in the structural relationships were minor. Our results indicate that good physical health directly contributes to reducing LTC needs among Japanese elderly. In addition, efforts to increase income and educational levels may help to decrease LTC needs by indirectly improving physical health.

  20. Ice age plant refugia in East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1979-01-01

    From the distribution of plants it has been inferred by some botanists that ice-free areas existed in East Greenland accommodating a flora which survived one or several ice ages in the area. Comparing this evidence with recent information on the chronology of glaciations and post-glacial vegetati...

  1. Lexical Borrowings in Spanish: Function, Length, Genealogy and Chronology.

    Science.gov (United States)

    Patterson, William T.

    1986-01-01

    A study reveals that lexical borrowing in Spanish, from a variety of languages including Latin, French, Italian, Greek, Arabic, Provencal, and Catalan, accounts for 41 percent of the basic Spanish vocabulary, with variation in source according to historical period. (MSE)

  2. Influência da maturação sexual, idade cronológica e índices de crescimento no limiar de lactato e no desempenho da corrida de 20 minutos Influencia de la madurez sexual, edad cronológica e índices de crecimiento en el límite de lactato y en el desempeño en carreras de velocidad de 20 minutos Influence of sexual maturation, chronological age and growth indices in lactate threshold and performance in the 20 minutes running

    Directory of Open Access Journals (Sweden)

    Deivis Elton Schlickmann Frainer

    2006-06-01

    evaluación de madurez sexual a través de los índices de Tanner (madurez sexual de genitales y madurez sexual del pelo pubiano; 2 test progresivo descontinuo de 3 x 800m (pista de atletismo para determinar V2,5, y 3 carreras de 20 minutos para determinar V20 y la [la] final. No fue encontrada asociación entre madurez sexual, edad cronológica e indicadores de crecimiento con V2,5. Solamente la estatura se mostró asociada con V20. Así, otras variables de desempeño, fisiológicas o biomecánicas, pueden influenciar más al final de la concentración de lactato y en las carreras de 20 minutos que las variables de crecimiento durante la adolescencia.Children and adolescents present less blood lactate concentrations ([la] than adults under certain loads. It is suggested that these differences are related to maturational aspects. The aim of this study was to verify the influence of sexual maturation, chronological age and growth indices (body weight, height and sum of two skinfolds - subscapular and triceps over the lactate threshold velocity, in the fixed lactate concentration of 2.5 mmol.l-1 (V2,5 and in the 20 minutes running (V20. Thirty-three boys, aged 13-15 years, who practice different sports were submitted to: 1 anthropometrical and sexual maturation evaluations through the Tanner index (sexual maturation of genitals and pubic hair; 2 progressive discontinuous test (3 x 800m in running track to determine V2,5; and 3 20 minutes running test to determine the V20 and final blood [la]. There were no associations between V2,5 and sexual maturation, neither chronological age nor growth index. As the only association verified was between V20 and height (r = 0,41; p < 0,05, the authors conclude that during adolescence other performance, physiological and/or biomechanical variables may play a greater role in lactate threshold and in the 20 minutes running than the growth variables.

  3. Chronology of Terra Firme formation in western Amazonia and implications for the diversification of Amazonian biota

    Science.gov (United States)

    Pupim, Fabiano do N.; Sawakushi, André O.; Hartmann, Gelvam A.; Savian, Jairo F.; Kern, Andrea K.; Mineli, Thays D.; Cruz, Francisco W.; Almeida, Renato P.; Grohmann, Carlos H.; Ribas, Camila C.; d'Horta, Fernando M.; Bertassoli, Dailson J.; Marconato, André; Nogueira, Luciana; Lohmann, Lúcia G.

    2017-04-01

    The shift from a large wetland dominated by avulsive channels and flooded forests to the incised transcontinental Amazon River valley (Várzea) bounded by non-flooded forests (Terra Firme) is suggested as one of the main drivers of diversification of the mega diverse Amazonian Biota. Nonetheless, there is no consensus about the timing of this landscape shift, with the current literature suggesting a period that ranges from the Miocene (11 Ma) and the Late Pleistocene (100 ka). This uncertainty may be due to a lack of absolute ages for the sediments forming Terra Firme forest substrates in western Amazonian lowlands. In Brazil, the Içá Formation represents the uppermost fluvial deposits of Terra Firme forests substrates in western Amazonia. Therefore, a reliable chronology for the last depositional stage of the Içá Formation is key for an improved understanding of the formation of the current Terra Firme-Várzea system. Four sediment profiles were sampled along the margins of the Solimões and Içá rivers for Optically Stimulated Luminescence (OSL) dating, geomagnetic excursions, and palynological analysis. OSL dating was performed in twelve samples using a Single Aliquot Regeneration (SAR) protocol in quartz sand grains. The equivalent doses ranged from 47 to 130 Gy (Central Age Model) and the dose rate values ranged from 0.4 to 2.0 Gy/ka. The resulting sediment burial ages range from 48 to 112 ka. Paleomagnetic data were obtained from samples collected at same profiles sampled for OSL dating and results suggest the presence of Post-Blake geomagnetic excursion ( 100 ka). The age of 100 ka for Post-Blake excursion are adopted for the Geomagnetic Instability Time Scale. Pollen assemblage data show a similarity to a more modern flora and the presence of Alnus clearly points towards Pleistocene deposition as it is unknown before in South America. The combined OSL, paleomagnetism and pollen data is a robust geochronological dataset that indicates Late Pleistocene

  4. Age assessment of young asylum seekers

    DEFF Research Database (Denmark)

    Hjern, Anders; Brendler-Lindqvist, Maria; Nørredam, Marie Louise

    2012-01-01

    to be of real use in this decision. Unclear guidelines and arbitrary practices may lead to alarming shortcomings in the protection of this high-risk group of children and adolescents in Europe. Medical participation, as well as non-participation, in these dubious decisions raises a number of ethical questions....... CONCLUSION: To improve care for young asylum seekers with undetermined age, we suggest better legal procedures for the determination of age and a more flexible approach to chronological age....

  5. A 548-year long tree-ring chronology of oak (Quercus spp.) for SE Slovenia and its significance as dating tool and climate archive

    OpenAIRE

    De Luis, Martin; Eckstein, Dieter; Zupančič, Martin; Čufar, Katarina

    2015-01-01

    Tree-ring series of oak, from both living trees (Quercus petraea and Q. robur) and historic timbers in SE Slovenia were assembled into a 548-year long regional chronology spanning the period A.D. 1456-2003. It is currently the longest and the most replicated oak chronology in this part of Europe at the transition between Mediterranean, Alpine and continental climatic effects. The chronology correlated significantly with regional and local chronologies up to 700 km apart in Austria, Hungary, S...

  6. The End Is (Not) Near: Aging, Essentialism, and Future Time Perspective

    Science.gov (United States)

    Weiss, David; Job, Veronika; Mathias, Maya; Grah, Stephanie; Freund, Alexandra M.

    2016-01-01

    Beliefs about aging influence how we interpret and respond to changes within and around us. Essentialist beliefs about aging are defined as views that link chronological age with inherent and immutable properties underlying aging-related changes. These beliefs may influence the experience of aging-related changes and shape people's outlook of the…

  7. Subjective Age and Changes in Memory in Older Adults.

    Science.gov (United States)

    Stephan, Yannick; Sutin, Angelina R; Caudroit, Johan; Terracciano, Antonio

    2016-07-01

    The subjective experience of aging, indexed by how old or young an individual feels, has been related to well-being and health-related outcomes among older adults. The present study examined whether subjective age is associated with memory level and changes, as indexed by measures of immediate and delayed recall. A complementary purpose was to test the mediating role of depressive symptoms and physical activity in the relation between subjective age and memory changes. Participants were drawn from three waves of the Health and Retirement Study. Subjective age, baseline memory measures, and covariates were assessed during the 2008 wave (N = 5809), depressive symptoms and physical activity were assessed again in the 2010 wave, and the follow-up memory measures were assessed in the 2012 wave. Regression analyses that included demographic, metabolic, and vascular covariates revealed that a younger subjective age at baseline was associated with better concurrent performance and with slower decline in immediate and delayed recall. Bootstrap procedures indicated that fewer depressive symptoms mediated these associations. Additional analyses revealed that memory level and change were unrelated to changes in subjective age. Beyond chronological age, the subjective experience of age is associated with cognitive aging. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Calcretes in the Thar desert: Genesis, chronology and ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The calcretes in the Thar desert occur in a variety of settings, including the piedmonts, sheet- wash aggraded plains; and this study adds calcretes in regolith and colluvio-alluvial plains to the group of settings in which calcretes occur in the region. Field logs, morphological details and analytical data such as petrographic, ...

  9. 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

  10. Gratitude From Early Adulthood to Old Age.

    Science.gov (United States)

    Allemand, Mathias; Hill, Patrick L

    2016-02-01

    Are there age differences in gratitude from early adulthood to old age? The current studies tested several ways by which an association between age and dispositional gratitude may present, by considering multiple measures on both fronts. We used data from three cross-sectional studies (total N = 1,736; total age range: 19-94). The results indicated that (a) age effects in gratitude are more likely to occur for subjective age in terms of future time perspective (i.e., people's perceptions of their remaining opportunities and time) than chronological age; (b) chronological age effects are more domain specific than general in nature; and (c) they are more likely to occur for the instrumental domain as compared to the interpersonal domain. Finally, the results indicated that (d) perceived future time, particularly with respect to remaining opportunities, mediates the relation between chronological age and general gratitude. Overall, the findings suggest that gratitude is subject to a variety of developmental influences across adulthood. © 2014 Wiley Periodicals, Inc.

  11. Aging of tissue-resident adult stem/progenitor cells and their pathological consequences.

    Science.gov (United States)

    Mimeault, M; Batra, S K

    2009-06-01

    The fascinating discovery of tissue-resident adult stem/progenitor cells in recent years led to an explosion of interest in the development of novel stem cell-based therapies for improving the regenerative capacity of these endogenous immature cells or transplanted cells for the repair of damaged and diseased tissues. In counterbalance, a growing body of evidence has revealed that the changes in phenotypic and functional properties of human adult stem/progenitor cells may occur during chronological aging and have severe pathological consequences. Especially, intense oxidative and metabolic stress and chronic inflammation, enhanced telomere attrition and defects in DNA repair mechanisms may lead to severe DNA damages and genomic instability in adult stem/progenitor cells with advancing age that may in turn trigger their replicative senescence and/or programmed cell death. Moreover, the changes in the intrinsic and extrinsic factors involved in the stringent control of self-renewal and multilineage differentiation capacities of these regenerative cells, including deregulated signals from the aged niche, may also contribute to their dysfunctions or loss during chronological aging. This age-associated decline in the regenerative capacity and number of functional adult stem/progenitor cells may increase the risk to develop certain diseases. At opposed end, the telomerase reactivation and accumulation of genetic alterations leading to a down-regulation of numerous tumor suppressor genes concomitant with the enhanced expression of diverse oncogenic products may result in their malignant transformation into cancer-initiating cells. Therefore, the rescue or replacement of aged and dysfunctional endogenous adult stem/progenitor cells or molecular targeting of their malignant counterpart, cancer stem/progenitor cells may constitute potential anti-aging and cancer therapies. These therapeutic strategies could be used for treating diverse devastating premature aging and age

  12. Chronology of magmatic and biological events during mass extinctions

    Science.gov (United States)

    Schaltegger, U.; Davies, J.; Baresel, B.; Bucher, H.

    2016-12-01

    For mass extinctions, high-precision geochronology is key to understanding: 1) the age and duration of mass extinction intervals, derived from palaeo-biodiversity or chemical proxies in marine sections, and 2) the age and duration of the magmatism responsible for injecting volatiles into the atmosphere. Using high-precision geochronology, here we investigate the sequence of events linked to the Triassic-Jurassic boundary (TJB) and the Permian-Triassic boundary (PTB) mass extinctions. At the TJB, the model of Guex et al. (2016) invokes degassing of early magmas produced by thermal erosion of cratonic lithosphere as a trigger of climate disturbance in the late Rhaetian. We provide geochronological evidence that such early intrusives from the CAMP (Central Atlantic Magmatic Province), predate the end-Triassic extinction event (Blackburn et al. 2013) by 100 kyr (Davies et al., subm.). We propose that these early intrusions and associated explosive volcanism (currently unidentified) initiate the extinction, followed by the younger basalt eruptions of the CAMP. We also provide accurate and precise calibration of the PTB in marine sections in S. China: The PTB and the extinction event coincide within 30 kyr in deep water settings; a hiatus followed by microbial limestone deposition in shallow water settings is of <100 kyr duration. The PTB extinction interval is preceded by up to 300 kyr by the onset of partly alkaline explosive, extrusive and intrusive rocks, which are suggested as the trigger of the mass extinction, rather than the subsequent basalt flows of the Siberian Traps (Burgess and Bowring 2015). From temporal constraints, the main inferences that can be made are: The duration of extinction events is in the x10 kyr range during the initial intrusive activity of a Large Igneous Province, and is postdated by the majority of basalt flows over several 100 kyr. For modeling climate change associated with mass extinctions, volatiles released from the basalt flows may

  13. Pump apparatus including deconsolidator

    Energy Technology Data Exchange (ETDEWEB)

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  14. [Chronology of ultrasonographic course of neonatal intraventricular hemorrhage stage III].

    Science.gov (United States)

    Monset-Couchard, M; Szwalkiewicz-Warowicka, E; de Bethmann, O

    1993-01-01

    During the 1981-90 decade, 31 unilateral grade III intraventricular hemorrhages (III IVH), with controlateral grade I or grade II, and 65 bilateral grade III IVH were detected by brain ultrasound studies in the neonatal intensive care unit of Port-Royal. Varied hemorrhages were present on day 1 in 66% of unilateral III IVH and 72% of bilateral III IVH, and in all cases by day 4. Bilateral grade III was reached only between days 4 and 8 in 32% of cases. Death rate was 35% in unilateral III IVH and 66% in bilateral III IVH. Median dates of observation were: days 2-3, clots in the third ventricle and cisterna magna; days 29-35, disappearance of clots in lateral ventricles; days 2-4, onset of ventricular dilatation; days 15-20, maximal dilatation; days 22-27, onset of regressive dilatation; day 54-3 months, maximal regression of dilatation. The total number of true hydrocephalus was 3/31 in unilateral III IVH and 12/65 in bilateral III IVH. The 20 survivors after unilateral III IVH had 17 regressive dilatations (10 spontaneous and 7 with acetazolamide), 1 hydrocephalus treated by ventriculo-peritoneal shunt (VPS), 2 regressions with late hydrocephalus (2 VPS). The 21 survivors after bilateral III IVH had 19 regressive dilatations (6 spontaneous and 13 with acetazolamide), and 2 hydrocephalus (2 VPS). A late limited dilatation reappeared between 3 and 9 months of age in infants with neonatal periventricular leukomalacias.

  15. Marine chronology based on C-14 dating on diatoms proteins

    International Nuclear Information System (INIS)

    Hatte, C.; Hodgins, G.; Jull, A.J.T.; Bishop, B.; Hatte, C.; Tesson, B.

    2008-01-01

    We present a new method of obtaining radiocarbon dates for proteins intrinsic to diatom frustules (sillafin). By asserting age models for sediment core samples that lack calcium carbonate, this method will improve interpretations of diatom-based paleo-proxies for either marine or lacustrine. In preparation for radiocarbon dating by Accelerator Mass Spectrometry, diatoms were concentrated from core sediment samples. The diatoms frustules were freed of any surface-bound organic matter, through chemical and physical treatments that will be discussed later in this paper. Compounds intrinsic to diatoms frustules were released from their opal matrix by HF dissolution. This method differs from approaches based on specific compound extractions from complex organic mixture by preparative chromatography because we eliminated most of the contaminated organic matter. The advantage of our method is that it does not require heavy cost investment and it can be added to a preparative chromatography protocol to ensure dating reliability. This method was applied to samples from a marine core collected in the Southern Ocean, that spans the last climatic cycle. We report on the radiocarbon dating results obtained on organic matter at each step of the chemical treatment, from bulk to sillafin and their interpretation. (authors)

  16. Differential Gene Expression and Aging

    Directory of Open Access Journals (Sweden)

    Laurent Seroude

    2002-01-01

    Full Text Available It has been established that an intricate program of gene expression controls progression through the different stages in development. The equally complex biological phenomenon known as aging is genetically determined and environmentally modulated. This review focuses on the genetic component of aging, with a special emphasis on differential gene expression. At least two genetic pathways regulating organism longevity act by modifying gene expression. Many genes are also subjected to age-dependent transcriptional regulation. Some age-related gene expression changes are prevented by caloric restriction, the most robust intervention that slows down the aging process. Manipulating the expression of some age-regulated genes can extend an organism's life span. Remarkably, the activity of many transcription regulatory elements is linked to physiological age as opposed to chronological age, indicating that orderly and tightly controlled regulatory pathways are active during aging.

  17. Comparative chronology of Archean HT/UHT crustal metamorphism

    Science.gov (United States)

    Caddick, Mark; Dragovic, Besim; Guevara, Victor

    2017-04-01

    the vast central and western parts of the PGD, peak temperatures range from 900-1000°C. LASS monazite and zircon ages, combined with ID-TIMS zircon and Sm-Nd garnet ages range from ˜2720 Ma to ˜2600 Ma, and combined with the thermometry, suggest that temperatures of >700˚ C were maintained region-wide for over 100 Ma, and that this was punctuated by thermal perturbations exceeding 900-950˚ C and occurring over substantially shorter timescales. The depths, temperatures and timescales inferred here suggest that although these regions were experiencing metamorphism within ˜100 Ma of each other, the primary driver for this metamorphism was different in each case. Timescale of metamorphism might be the most important constrained parameter here, highlighting the benefit of high resolution isotopic and geospeedometry approaches. [1] Dragovic et al., 2016. Precamb. Res., 283, 24-49. [2] Guevara et al., 2016. AGU abstracts with programs.

  18. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author, Volume 18 (1) through Volume 22 (6)

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Passiakos, M.

    1982-06-01

    This index to Nuclear Safety covers articles published in Nuclear Safety, Volume 18, Number 1 (January-February 1977) through Volume 22, Number 6 (November-December 1981). The index is divided into three section: a chronological list of articles (including abstracts), a permuted-title (KWIC) index, and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. Over 300 technical articles published in Nuclear Safety in the last 5 years are listed in this index.

  19. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author. Vol. 11(1)--Vol. 18(6)

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Klein, A.

    1978-01-01

    This index to Nuclear Safety covers articles published in Nuclear Safety, Vol. 11, No. 1 (January-February 1970), through Vol. 18, No. 6 (November-December 1977). It is divided into three sections: a chronological list of articles (including abstracts) followed by a permuted-title (KWIC) index and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center (NSIC), covers all safety aspects of nuclear power reactors and associated facilities. Over 450 technical articles published in Nuclear Safety in the last eight years are listed in this index

  20. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author. Vol. 11(1)--Vol. 18(6)

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1978-04-11

    This index to Nuclear Safety covers articles published in Nuclear Safety, Vol. 11, No. 1 (January-February 1970), through Vol. 18, No. 6 (November-December 1977). It is divided into three sections: a chronological list of articles (including abstracts) followed by a permuted-title (KWIC) index and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center (NSIC), covers all safety aspects of nuclear power reactors and associated facilities. Over 450 technical articles published in Nuclear Safety in the last eight years are listed in this index.

  1. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author, Volume 18 (1) through Volume 22 (6)

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Passiakos, M.

    1982-06-01

    This index to Nuclear Safety covers articles published in Nuclear Safety, Volume 18, Number 1 (January-February 1977) through Volume 22, Number 6 (November-December 1981). The index is divided into three section: a chronological list of articles (including abstracts), a permuted-title (KWIC) index, and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. Over 300 technical articles published in Nuclear Safety in the last 5 years are listed in this index

  2. Optical modulator including grapene

    Science.gov (United States)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  3. Influence of advancing age on clinical presentation, treatment efficacy and safety, and long-term outcome of inducible paroxysmal supraventricular tachycardia without pre-excitation syndromes: A cohort study of 1960 patients included over 25 years

    Science.gov (United States)

    Brembilla-Perrot, Béatrice; Sellal, Jean Marc; Olivier, Arnaud; Villemin, Thibaut; Beurrier, Daniel; Vincent, Julie; Manenti, Vladimir; de Chillou, Christian; Bozec, Erwan

    2018-01-01

    Aim To investigate the influence of increasing age on clinical presentation, treatment and long-term outcome in patients with inducible paroxysmal supraventricular tachycardia (SVT) without pre-excitation syndromes. Methods Clinical and electrophysiological study (EPS) data, as well as long-term clinical outcome (mean follow-up 2.4±4.0 years) were collected in patients referred for regular tachycardia with inducible SVT during EPS without pre-excitation. Results Among 1960 referred patients, 301 patients (15.4%) were aged ≥70 (70–97). In this subset, anticoagulants were prescribed in 49 patients following an erroneous diagnosis of atrial tachycardia and 14 were previously erroneously diagnosed with ventricular tachycardia because of wide QRS. Ablation was performed more frequently in patients ≥70 despite more frequent failure and complications. During follow-up, higher risks of AF, stroke, pacemaker implantation and death were observed in patients ≥70 whereas SVT recurrences were similar in both age groups. In multivariable analysis, age ≥70 was independently associated with higher risks of SVT-related adverse events prior to ablation (OR = 1.93, 1.41–2.62, pSVT without pre-excitation syndromes are elderly. These patients exhibit higher risks of erroneous tachycardia diagnosis prior to EPS as well as failure and/or complication of ablation, but similar risk of SVT recurrence. These results support performing transesophageal EPS in most patients and intracardiac EPS in selected patients. EPS may furthermore prove useful in elderly patients with regular tachycardia, mainly by avoiding treatment based on an erroneous diagnosis. PMID:29304037

  4. Chondrite chronology by initial Sr-87/Sr-86 in phosphates?

    Science.gov (United States)

    Podosek, Frank A.; Brannon, Joyce C.

    1991-01-01

    New data are presented on Rb-Sr isotope analyses of phosphates from nine ordinary chondrites, including accurate identification of initial Sr-87/Sr-86. The initial Sr-87/Sr-86 ratios found in this study were generally significantly higher than the more primitive initial Sr-87/Sr-86 ratios inferred for carbonaceous chondrite refractory inclusions, basaltic achondrites, or bulk ordinary chondrites. Such elevation of initial Sr-87/Sr-86 is generally considered to reflect isotopic redistribution during metamorphism. However, in this study, no evident correlation was found between the phosphate initial Sr-87/Sr-86 compositions and the metamorphic grade. Two possible alternative hypotheses for high initial Sr-87/Sr-86 ratios are considered.

  5. Chronologic constraints on the tectonic evolution of the Wilson Lake terrane of the Grenville Province, Canada

    DEFF Research Database (Denmark)

    Reno II, Barry Len; Korhonen, F.J.; Stout, J.H.

    the Grenville Orogen in North America. Many of these terranes record evidence of two orogenies: the Labradorian Orogeny at ca. 1710-1600 Ma, and the Grenville Orogeny at ca. 1080-980 Ma. The rocks in the Wilson Lake terrane are interpreted to have been subjected to peak pressures of ~0.95 GPa...... and ~930°C during the Labradorian Orogeny (Korhonen et al., in prep., Stability of sapphirine + quartz in the Wilson Lake terrane: calculated equilibria in NCKFMASHTO). The final amalgamation of the Wilson Lake terrane over the underlying Parautochthonous Belt is interpreted to have occurred during...... the Grenville Orogeny, when the terrane was subjected to a lower-T (500-350°C) overprinting. However, petrologic and chronologic evidence for the Grenville orogeny is limited in the Wilson Lake terrane. Here we present results from a monazite chemical (U-Th)-Pb chronologic study in order to provide constraints...

  6. Chronological analysis of architectural and acoustical indices in music performance halls.

    Science.gov (United States)

    Kwon, Youngmin; Siebein, Gary W

    2007-05-01

    This study aims to identify the changes in architectural and acoustical indices in halls for music performance built in the 18th through the 20th Centuries. Seventy-one halls are classified in five specific periods from the Classical Period (1751-1820) to the Contemporary Period (1981-2000) based on chronology in music and architectural acoustics. Architectural indices such as room shape, seating capacity, room volume, balcony configuration, and the like as well as acoustical indices such as RT, EDT, G, C80, IACC, and the like for the halls found in the literature are chronologically tabulated and statistically analyzed to identify trends and relationships in architectural and acoustical design for each of the historical periods identified. Some indices appear correlated with each other.

  7. Sediment chronology and polycyclic aromatic hydrocarbon concentrations and fluxes in Cayuga Lake, NY

    Energy Technology Data Exchange (ETDEWEB)

    Heit, M.; Tan, Y.L.; Miller, K.M.; Quanci, J.; Marinetti, C.; Silvestri, S.; Swain, A.M.; Winkler, M.G.

    1986-02-01

    We describe experiments aimed at determining the deposition history of energy-related, particulate-associated, potentially carcinogenic polycyclic aromatic hydrocarbons (PAH) deposited in the sediments of Cayuga Lake in the Finger Lakes Region of Central New York State. The sediment cores were chronologically dated from measurements of artificial and natural radionuclides (/sup 137/Cs, Pu-isotopes, /sup 210/Pb) and pollen. Diatoms and charcoal were used to determine historic changes in the Cayuga Lake basin. These methods showed agreement in chronology and also indicated that the sediments were not mixed or diffused to any great extent so that clear pollutant trends could be established. Historic changes in concentrations (ng/g dry wt.) and flux (ng/cm/sup 2//yr) of 3 to 7 ring PAH compounds were determined. Estimates of the atmospheric component of PAH flux to the sediments were made using the ratio of /sup 137/Cs inventories in sediments to that deposited on undisturbed soils.

  8. Comparison of the glacial chronology of Eastern Baffin Island, East Greenland and Camp century accumulation record

    DEFF Research Database (Denmark)

    Andrews, John; Funder, Svend Visby; Hjort, Chritian

    1974-01-01

    level between 120,000 and 70,000 B.P. may well be related to glacierization of high arctic land masses under conditions of heavy snowfall. The subsequent reduction of accumulation in these high arctic areas then leads to a reduction of ice volume with a dry, cold interstadial correlative in time......Independently derived glacial chronologies from eastern Baffin Island, Canadian Arctic, and from East Greenland show essentially similar glaciologic trends that arc notably different from the response of the southern margins of the Laurentide and FCllnoscandia Ice Sheets. The critical aspe......~ts of both chronologies and the related extcn t of the ice sheets are (1) an early and maximum glacial stade, during the early phase of the last glaciation, reaching its peak abqut 100,000 to 75,000 yr ago; (2) an in terstadial about .70,000 n.p.; (3) an ice advance peaking about 45,000 yr ago; (4...

  9. Perceived age as clinically useful biomarker of ageing: cohort study

    DEFF Research Database (Denmark)

    Christensen, Kaare; Thinggaard, Mikael; McGue, Matt

    2009-01-01

    OBJECTIVE: To determine whether perceived age correlates with survival and important age related phenotypes. DESIGN: Follow-up study, with survival of twins determined up to January 2008, by which time 675 (37%) had died. SETTING: Population based twin cohort in Denmark. PARTICIPANTS: 20 nurses, 10...... young men, and 11 older women (assessors); 1826 twins aged >or=70. MAIN OUTCOME MEASURES: Assessors: perceived age of twins from photographs. Twins: physical and cognitive tests and molecular biomarker of ageing (leucocyte telomere length). RESULTS: For all three groups of assessors, perceived age...... was significantly associated with survival, even after adjustment for chronological age, sex, and rearing environment. Perceived age was still significantly associated with survival after further adjustment for physical and cognitive functioning. The likelihood that the older looking twin of the pair died first...

  10. Radiographic correlation of dental and skeletal age: Third molar, an age indicator.

    Science.gov (United States)

    Suma, Gn; Rao, Balaji B; Annigeri, Rajeshwari G; Rao, Dayashankara Jk; Goel, Sumit

    2011-01-01

    Age estimation plays a great role in forensic investigations, orthodontic and surgical treatment planning, and tooth transplantation. Teeth offer an excellent material for age determination by stages of development below the age of 25 years and by secondary changes after the age of 25 years. Third molar is often not included for this purpose due to its notorious developmental patterns. The aim of this study was to evaluate the development of third molar anlage in relation to skeletal maturities and the chronological age. One hundred and fifty-six young individuals, 78 males and 78 females, were selected. The stages of development of all the third molars in every individual were determined from panoramic radiographs. The skeletal development was assessed using hand wrist radiographs. Data were analyzed statistically for mean value, standard deviation and the relationship between the recorded characteristics. A STRONG CORRELATION WAS FOUND BETWEEN THIRD MOLAR DEVELOPMENT AND SKELETAL MATURITY (IN MALES: r=0.88, Pthird molar and 0.89 for mandibular third molar, Page, developmental stages of third molars and maturation of epiphyses of hand. Any of the three parameters could be used for the assessment of other maturities.

  11. A CHRONOLOGICAL FRAMEWORK FOR THE HOLOCENE VEGETATIONAL HISTORY OF CENTRAL MINNESOTA: THE STEEL LAKE POLLEN RECORD

    Energy Technology Data Exchange (ETDEWEB)

    Wright, H E; Stefanova, I; Tian, J; Brown, T A; Hu, F S

    2003-11-10

    Paleorecords from Minnesota and adjacent areas have often been used to evaluate large-scale climatic processes in the mid-continent of North America. However, most of these records are compromised by chronological flaws, making problematic any comparisons with climatic interpretations based on other records (e.g., GISP2 in Greenland). We report here a high-resolution pollen record with a secure chronology constrained by 26 {sup 14}C dates on terrestrial macrofossils from Steel Lake, central Minnesota. About 11,200 years ago (calibrated yr BP) the late-glacial Picea forest near Steel Lake was succeeded abruptly by Pinus banksiana and/or resinosa. The Pinus forest began to open 9.4 ka cal BP with the expansion of prairie taxa, and a pine parkland or savanna prevailed until about 8 ka cal BP, when Quercus replaced Pinus to become the dominant tree in the prairie areas for 4500 years. The close chronological control permits the correlation of key vegetational changes with those at other reliably dated sites in the eastern Dakotas and in Minnesota, suggesting that the abrupt decline of the spruce forest was time-transgressive from southwest to northeast during 2000 years, and that the development of prairie was time-transgressive in the same direction over 2600 years. Correlation of key pollen horizons at Steel Lake with those in the high-resolution pollen profiles of Elk Lake, ca. 50 km northwest of Steel Lake, suggests that the well-known Elk Lake varve chronology for the early Holocene is about 1000 years too young.

  12. Caloric Restriction-Induced Extension of Chronological Lifespan Requires Intact Respiration in Budding Yeast

    OpenAIRE

    Kwon, Young-Yon; Lee, Sung-Keun; Lee, Cheol-Koo

    2017-01-01

    Caloric restriction (CR) has been shown to extend lifespan and prevent cellular senescence in various species ranging from yeast to humans. Many effects of CR may contribute to extend lifespan. Specifically, CR prevents oxidative damage from reactive oxygen species (ROS) by enhancing mitochondrial function. In this study, we characterized 33 single electron transport chain (ETC) gene-deletion strains to identify CR-induced chronological lifespan (CLS) extension mechanisms. Interestingly, defe...

  13. Karst evolution of the Garraf Massif (Barcelona, Spain): Doline formation, chronology and archaeopalaeontological archives

    OpenAIRE

    Daura, J.; Sanz, M.; Fornós, Joan J.; Asensio, A.; Julià Brugués, Ramón

    2014-01-01

    © 2014, (publisher). All rights reserved. Karst landscape evolution has been widely studied in recent years on karst plateaus, but the use of dating methods has not usually been possible owing to a lack of data. The intensely karstified GarrafMassif, however, presents large solution dolines and several shafts that contain archaeological and palaentological remains that can be used for determining the chronological framework of the karstification processes. These sites have been dated using va...

  14. On the palaeoclimatic potential of a millennium-long oak ring width chronology from Slovakia

    Czech Academy of Sciences Publication Activity Database

    Prokop, O.; Kolář, Tomáš; Büntgen, Ulf; Kyncl, J.; Bošela, M.; Choma, M.; Barta, P.; Rybníček, Michal

    2016-01-01

    Roč. 40, DEC (2016), s. 93-101 ISSN 1125-7865 R&D Projects: GA MŠk(CZ) LO1415; GA ČR GA13-04291S Institutional support: RVO:67179843 Keywords : Composite tree-ring chronology * European oak * Palaeoclimatology * Random update sampling * Ring width * Slovakia Subject RIV: EH - Ecology, Behaviour Impact factor: 2.259, year: 2016

  15. To Correct or Not to Correct: Age Adjustment for Prematurity.

    Science.gov (United States)

    Aylward, Glen P.; And Others

    To evaluate whether conceptional or chronologic age should be used to determine scores in developmental follow-up studies, a study was made of 236 normal and 66 neurologically abnormal infants who were similar with respect to conceptional age but different with respect to degree of prematurity. Assessments of possible differences in cognitive and…

  16. DNA damage: A main determinant of vascular aging

    NARCIS (Netherlands)

    P.K. Bautista-Niño (Paula); E. Portilla-Fernandez (Eliana); D.E. Vaughan (Douglas E.); A.H.J. Danser (Jan); A.J.M. Roks (Anton)

    2016-01-01

    textabstractVascular aging plays a central role in health problems and mortality in older people. Apart from the impact of several classical cardiovascular risk factors on the vasculature, chronological aging remains the single most important determinant of cardiovascular problems. The causative

  17. Risk Factors for Obesity at Age 3 in Alaskan Children, Including the Role of Beverage Consumption: Results from Alaska PRAMS 2005-2006 and Its Three-Year Follow-Up Survey, CUBS, 2008-2009

    Science.gov (United States)

    Wojcicki, Janet M.; Young, Margaret B.; Perham-Hester, Katherine A.; de Schweinitz, Peter; Gessner, Bradford D.

    2015-01-01

    Background Prenatal and early life risk factors are associated with childhood obesity. Alaska Native children have one of the highest prevalences of childhood obesity of all US racial/ethnic groups. Methods Using the Pregnancy Risk Assessment Monitoring System (PRAMS) and the follow-up survey at 3 years of age (CUBS), we evaluated health, behavioral, lifestyle and nutritional variables in relation to obesity (95th percentile for body mass index (BMI)) at 3 years of age. Multivariate logistic regression modeling was conducted using Stata 12.0 to evaluate independent risk factors for obesity in non-Native and Alaska Native children. Results We found an obesity prevalence of 24.9% in all Alaskan and 42.2% in Alaska Native 3 year olds. Among Alaska Native children, obesity prevalence was highest in the Northern/Southwest part of the state (51.6%, 95%CI (42.6-60.5)). Independent predictive factors for obesity at age 3 years in Alaska non-Native children were low income (obesity (OR 2.01, 95%CI 1.01-4.01) and longer duration of breastfeeding was protective (OR 0.95, 95%CI 0.91-0.995). Among Alaska Native children, predictive factors were witnessing domestic violence/abuse as a 3 year-old (OR 2.28, 95%CI 1.17-7.60). Among obese Alaska Native children, there was an increased daily consumption of energy dense beverages in the Northern/Southwest region of the state, which may explain higher rates of obesity in this part of the state. Conclusions The high prevalence of obesity in Alaska Native children may be explained by differences in lifestyle patterns and food consumption in certain parts of the state, specifically the Northern/Southwest region, which have higher consumption of energy dense beverages. PMID:25793411

  18. Reconstructions of Columbia River streamflow from tree-ring chronologies in the Pacific Northwest, USA

    Science.gov (United States)

    Littell, Jeremy; Pederson, Gregory T.; Gray, Stephen T.; Tjoelker, Michael; Hamlet, Alan F.; Woodhouse, Connie A.

    2016-01-01

    We developed Columbia River streamflow reconstructions using a network of existing, new, and updated tree-ring records sensitive to the main climatic factors governing discharge. Reconstruction quality is enhanced by incorporating tree-ring chronologies where high snowpack limits growth, which better represent the contribution of cool-season precipitation to flow than chronologies from trees positively sensitive to hydroclimate alone. The best performing reconstruction (back to 1609 CE) explains 59% of the historical variability and the longest reconstruction (back to 1502 CE) explains 52% of the variability. Droughts similar to the high-intensity, long-duration low flows observed during the 1920s and 1940s are rare, but occurred in the early 1500s and 1630s-1640s. The lowest Columbia flow events appear to be reflected in chronologies both positively and negatively related to streamflow, implying low snowpack and possibly low warm-season precipitation. High flows of magnitudes observed in the instrumental record appear to have been relatively common, and high flows from the 1680s to 1740s exceeded the magnitude and duration of observed wet periods in the late-19th and 20th Century. Comparisons between the Columbia River reconstructions and future projections of streamflow derived from global climate and hydrologic models show the potential for increased hydrologic variability, which could present challenges for managing water in the face of competing demands

  19. Comparison of the Effect of Vaginal Zataria multiflora Cream and Oral Metronidazole Pill on Results of Treatments for Vaginal Infections including Trichomoniasis and Bacterial Vaginosis in Women of Reproductive Age

    OpenAIRE

    Abdali, Khadijeh; Jahed, Leila; Amooee, Sedigheh; Zarshenas, Mahnaz; Tabatabaee, Hamidreza; Bekhradi, Reza

    2015-01-01

    Effect of Zataria multiflora on bacterial vaginosis and Trichomonas vaginalis is shown in vivo and in vitro. We compare the effectiveness of Zataria multiflora cream and oral metronidazole pill on results of treatment for vaginal infections including Trichomonas and bacterial vaginosis; these infections occur simultaneously. The study included 420 women with bacterial vaginosis, Trichomonas vaginalis, or both infections together, who were randomly divided into six groups. Criteria for diagnos...

  20. Western Saudi adolescent age estimation utilising third molar development.

    Science.gov (United States)

    Alshihri, Amin M; Kruger, Estie; Tennant, Marc

    2014-07-01

    The aim of this study was to establish reference data on third molar morphology/development for age estimation in Western Saudi adolescents, between ages 14 and 23 years of old. The orthopantomograms of 130 individuals (males and females), were examined, and the stage of third molar development were evaluated. Mean ages, standard deviations, and percentile distributions are presented for each stage of development. The mean estimated age for all participants (n = 130) was 219.7 months, and this differed significantly (P age (226.5 months). Deviations of predicted age from real age showed 28.5% of all participants had their age estimated within 1 year (±12 months) of their chronological age. Most (43%) had their age underestimated by more than 12 months and the remaining 28.5% had their age overestimated by more than 12 months of their chronological age. Differences in left-right symmetry information of third molars were detected and were higher in the maxilla (92%) than in the mandible (82%). For all molars reaching stage "H" most individuals (males and females) were over the age 18 years of old. Males reach the developmental stages earlier than females. Third molar tooth development can be reliably used to generate mean age and the estimated age range for an individual of unknown chronological age. Further studies with large populations are needed for better statistical results.

  1. Combined ESR/U-series chronology of Acheulian hominid-bearing layers at Trinchera Galeria site, Atapuerca, Spain

    International Nuclear Information System (INIS)

    Falgueres, Christophe; Bahain, Jean-Jacques; Shao, Qingfeng; Bischoff, James L.; Perez-Gonzalez, Alfredo; Ortega, Ana Isabel; Bermudez de Castro, Jose Maria; Olle, Andreu; Vallverdu, Josep; Quiles, Anita; Ghaleb, Bassam; Moreno, Davinia; Dolo, Jean-Michel; Vallverdu, Josep; Carbonell, Eudald; Arsuaga, Juan Luis

    2013-01-01

    The Sierra de Atapuerca, northern Spain, is known from many prehistoric and paleontologic sites documenting human prehistory in Europe. Three major sites, Gran Dolina, Galeria and Sima del Elefante, range in age from the oldest hominin of Western Europe dated to 1.1 to 1.3 Ma (millions of years ago) at Sima del Elefante to c.a. 0.2 Ma on the top of the Galeria archaeological sequence. Recently, a chronology based on luminescence methods (Thermoluminescence [TL] and Infrared Stimulated Luminescence [IRSL]) applied to cave sediments was published for the Gran Dolina and Galeria sites. The authors proposed for Galeria an age of 450 ka (thousands of years ago) for the units lower GIII and GII, suggesting that the human occupation there is younger than the hominid remains of Sima de los Huesos (≥530 ka) around 1 km away. In this paper, we present new results obtained by combined Electron Spin Resonance/Uranium-series (ESR/U-series) dating on 20 herbivorous teeth from different levels at the Galeria site. They are in agreement with the TL results for the upper part of the stratigraphic sequence (GIV and GIIIb), in the range of between 200 and 250 ka. But for the GIIIa to GIIb levels, the TL ages become abruptly older by 200 ka while ESR ages remain relatively constant. Finally, the TL and ESR data agree in the lowest part of the section (GIIa); both fall in the range of around 350-450 ka. Our results suggest a different interpretation for the GII, GIII and GIV units of Galeria and the upper part of Gran Dolina (TD10 and TD11) than obtained by TL. The ESR/U-series results are supported by a Bayesian analysis, which allows a better integration between stratigraphic information and radiometric data. (authors)

  2. Risk factors for obesity at age 3 in Alaskan children, including the role of beverage consumption: results from Alaska PRAMS 2005-2006 and its three-year follow-up survey, CUBS, 2008-2009.

    Directory of Open Access Journals (Sweden)

    Janet M Wojcicki

    Full Text Available Prenatal and early life risk factors are associated with childhood obesity. Alaska Native children have one of the highest prevalences of childhood obesity of all US racial/ethnic groups.Using the Pregnancy Risk Assessment Monitoring System (PRAMS and the follow-up survey at 3 years of age (CUBS, we evaluated health, behavioral, lifestyle and nutritional variables in relation to obesity (95th percentile for body mass index (BMI at 3 years of age. Multivariate logistic regression modeling was conducted using Stata 12.0 to evaluate independent risk factors for obesity in non-Native and Alaska Native children.We found an obesity prevalence of 24.9% in all Alaskan and 42.2% in Alaska Native 3 year olds. Among Alaska Native children, obesity prevalence was highest in the Northern/Southwest part of the state (51.6%, 95%CI (42.6-60.5. Independent predictive factors for obesity at age 3 years in Alaska non-Native children were low income (<$10,000 in the year before the child was born (OR 3.94, 95%CI 1.22--17.03 and maternal pre-pregnancy obesity (OR 2.01, 95%CI 1.01-4.01 and longer duration of breastfeeding was protective (OR 0.95, 95%CI 0.91-0.995. Among Alaska Native children, predictive factors were witnessing domestic violence/abuse as a 3 year-old (OR 2.28, 95%CI 1.17-7.60. Among obese Alaska Native children, there was an increased daily consumption of energy dense beverages in the Northern/Southwest region of the state, which may explain higher rates of obesity in this part of the state.The high prevalence of obesity in Alaska Native children may be explained by differences in lifestyle patterns and food consumption in certain parts of the state, specifically the Northern/Southwest region, which have higher consumption of energy dense beverages.

  3. Dietary echium oil increases long-chain n-3 PUFAs, including docosapentaenoic acid, in blood fractions and alters biochemical markers for cardiovascular disease independently of age, sex, and metabolic syndrome.

    Science.gov (United States)

    Kuhnt, Katrin; Fuhrmann, Claudia; Köhler, Melanie; Kiehntopf, Michael; Jahreis, Gerhard

    2014-04-01

    Dietary supplementation with echium oil (EO) containing stearidonic acid (SDA) is a plant-based strategy to improve long-chain (LC) n-3 (ω-3) polyunsaturated fatty acid (PUFA) status in humans. We investigated the effect of EO on LC n-3 PUFA accumulation in blood and biochemical markers with respect to age, sex, and metabolic syndrome. This double-blind, parallel-arm, randomized controlled study started with a 2-wk run-in period, during which participants (n = 80) were administered 17 g/d run-in oil. Normal-weight individuals from 2 age groups (20-35 and 49-69 y) were allotted to EO or fish oil (FO; control) groups. During the 8-wk intervention, participants were administered either 17 g/d EO (2 g SDA; n = 59) or FO [1.9 g eicosapentaenoic acid (EPA); n = 19]. Overweight individuals with metabolic syndrome (n = 19) were recruited for EO treatment only. During the 10-wk study, the participants followed a dietary n-3 PUFA restriction, e.g., no fish. After the 8-wk EO treatment, increases in the LC n-3 metabolites EPA (168% and 79%) and docosapentaenoic acid [DPA (68% and 39%)] were observed, whereas docosahexaenoic acid (DHA) decreased (-5% and -23%) in plasma and peripheral blood mononuclear cells, respectively. Compared with FO, the efficacy of EO to increase EPA and DPA in blood was significantly lower (∼25% and ∼50%, respectively). A higher body mass index (BMI) was associated with lower relative and net increases in EPA and DPA. Compared with baseline, EO significantly reduced serum cholesterol, LDL cholesterol, oxidized LDL, and triglyceride (TG), but also HDL cholesterol, regardless of age and BMI. In the FO group, only TG decreased. Overall, daily intake of 15-20 g EO increased EPA and DPA in blood but had no influence on DHA. EO lowered cardiovascular risk markers, e.g., serum TG, which is particularly relevant for individuals with metabolic syndrome. Natural EO could be a noteworthy source of n-3 PUFA in human nutrition.

  4. Emergence of entrepreneurial behaviour : The role of age-based self-image

    NARCIS (Netherlands)

    Kautonen, Teemu; Hatak, Isabella; Kibler, Ewald; Wainwright, Thomas

    2015-01-01

    This study introduces an individual’s perception of their entrepreneurial potential in terms of their age (age-based self-image) to complement chronological age as a predictor of entrepreneurial behaviour. The principal hypothesis is that a positive age-based self-image enhances the likelihood of

  5. The influence of age perception on women consumer behavior

    Directory of Open Access Journals (Sweden)

    Damijan Mumel

    2007-07-01

    Full Text Available Demographic changes of inhabitants are a factor changing increasingly the situation in Europe and other developed parts of the world. People live longer and are more vital than in the past. The ageing of population affects many areas of everyday life. The number of older persons grows and their characteristics are essentially different than the characteristics of past generations. Those were the reasons for the authors’ interest in the perception of the psychological age of women older than 50. They also focused on the differences between a group of women who see themselves as younger than their actual age and a group of women who feel older. The third field of interest was how that influence on their behavior as a consumer. A total of 225 women were included in the research. To acquire the informations we use a questionnaire, which includes questions about the chronological age against the perceived age and questions about 23 values, 31 free time activities and 15 sports activities. Results show that more than a half of the women feel younger than they really are, 40% feel as old as they are and less than 5% feel older than their actual age. More than a half of the interviewed women think they look 10 years younger. Most of the women think that a person is old when he/she is over 70.

  6. Molecular insights into the pathogenesis of Alzheimer's disease and its relationship to normal aging.

    Directory of Open Access Journals (Sweden)

    Alexei A Podtelezhnikov

    Full Text Available Alzheimer's disease (AD is a complex neurodegenerative disorder that diverges from the process of normal brain aging by unknown mechanisms. We analyzed the global structure of age- and disease-dependent gene expression patterns in three regions from more than 600 brains. Gene expression variation could be almost completely explained by four transcriptional biomarkers that we named BioAge (biological age, Alz (Alzheimer, Inflame (inflammation, and NdStress (neurodegenerative stress. BioAge captures the first principal component of variation and includes genes statistically associated with neuronal loss, glial activation, and lipid metabolism. Normally BioAge increases with chronological age, but in AD it is prematurely expressed as if some of the subjects were 140 years old. A component of BioAge, Lipa, contains the AD risk factor APOE and reflects an apparent early disturbance in lipid metabolism. The rate of biological aging in AD patients, which cannot be explained by BioAge, is associated instead with NdStress, which includes genes related to protein folding and metabolism. Inflame, comprised of inflammatory cytokines and microglial genes, is broadly activated and appears early in the disease process. In contrast, the disease-specific biomarker Alz was selectively present only in the affected areas of the AD brain, appears later in pathogenesis, and is enriched in genes associated with the signaling and cell adhesion changes during the epithelial to mesenchymal (EMT transition. Together these biomarkers provide detailed description of the aging process and its contribution to Alzheimer's disease progression.

  7. Chronological bias in randomized clinical trials arising from different types of unobserved time trends.

    Science.gov (United States)

    Tamm, M; Hilgers, R-D

    2014-01-01

    In clinical trials patients are commonly recruited sequentially over time incurring the risk of chronological bias due to (unobserved) time trends. To minimize the risk of chronological bias, a suitable randomization procedure should be chosen. Considering different time trend scenarios, we aim at a detailed evaluation of the extent of chronological bias under permuted block randomization in order to provide recommendations regarding the choice of randomization at the design stage of a clinical trial and to assess the maximum extent of bias for a realized sequence in the analysis stage. For the assessment of chronological bias we consider linear, logarithmic and stepwise trends illustrating typical changes during recruitment in clinical practice. Bias and variance of the treatment effect estimator as well as the empirical type I error rate when applying the t-test are investigated. Different sample sizes, block sizes and strengths of time trends are considered. Using large block sizes, a notable bias exists in the estimate of the treatment effect for specific sequences. This results in a heavily inflated type I error for realized worst-case sequences and an enlarged mean squared error of the treatment effect estimator. Decreasing the block size restricts these effects of time trends. Already applying permuted block randomization with two blocks instead of the random allocation rule achieves a good reduction of the mean squared error and of the inflated type I error. Averaged over all sequences, the type I error of the t-test is far below the nominal significance level due to an overestimated variance. Unobserved time trends can induce a strong bias in the treatment effect estimate and in the test decision. Therefore, already in the design stage of a clinical trial a suitable randomization procedure should be chosen. According to our results, small block sizes should be preferred, but also medium block sizes are sufficient to restrict chronological bias to an

  8. Communication & Aging.

    Science.gov (United States)

    Arnold, William E.

    This extensive bibliography contains more than 1,800 entries about communication and aging. The citations include journal articles, unpublished papers, speeches, dissertations, research studies, and books that relate aging and the aged to a variety of topics, including the following: physiological deterioration, socialization, political…

  9. Examination of DNA methylation status of the ELOVL2 marker may be useful for human age prediction in forensic science.

    Science.gov (United States)

    Zbieć-Piekarska, Renata; Spólnicka, Magdalena; Kupiec, Tomasz; Makowska, Żanetta; Spas, Anna; Parys-Proszek, Agnieszka; Kucharczyk, Krzysztof; Płoski, Rafał; Branicki, Wojciech

    2015-01-01

    Age estimation in forensic investigations may complement the prediction of externally visible characteristics and the inference of biogeographical ancestry, thus allowing a better description of an unknown individual. Multiple CpG sites that show linear correlation between age and degree of DNA methylation have been identified in the human genome, providing a selection of candidates for age prediction. In this study, we optimized an assay based on bisulfite conversion and pyrosequencing of 7 CpG sites located in the ELOVL2 gene. Examination of 303 blood samples collected from individuals aged 2-75 years allowed selection of the most informative site, explaining 83% of variation in age. The final linear regression model included two CpG sites in ELOVL2 and enabled age prediction with R(2)=0.859, prediction error=6.85 and mean absolute deviation MAD=5.03. Examination of a testing set of 124 blood samples (MAD=5.75) showed that 68.5% of samples were correctly predicted, assuming that chronological and predicted ages matched ± 7 years. It was found that the ELOVL2 methylation status in bloodstains had not changed significantly after 4 weeks of storage in room temperature conditions. Analysis of 45 bloodstains deposited on tissue paper after 5, 10 and 15 years of storage in room conditions indicated that although a gradual decrease of positive PCR results was observed, the general age prediction success rate remained similar and equaled 60-78%. The obtained results show that the ELOVL2 locus provides a very good source of information about human chronological age based on analysis of blood, including bloodstains, and it may constitute a powerful and reliable predictor in future forensic age estimation models. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Chronologic model and transgressive-regressive signatures in the late neocene siliciclastic foundation (long key formation) of the Florida keys

    Science.gov (United States)

    Guertin, L.A.; McNeill, D.F.

    1999-01-01

    Recent drilling of continuous cores in southernmost Florida has documented a thick unit of upper Neogene siliciclastics subjacent to surficial shallow-water Quaternary carbonates exposed on islands of the Florida Keys. The siliciclastics comprise the Long Key Formation and were identified in two cores collected from the middle and upper Florida Keys. Achronologic model based on new planktic foraminiferal biochronology and strontium-isotope chronology suggests the timing of siliddastic deposition and provides a basis for regional correlation. The chronologic model, supplemented by vertical trends in quartz grain size, pattern of planktic menardiiform coiling direction, and paleoenvironmental interpretations of benthic foraminiferal assemblages, shows that the Long Key Formatio