WorldWideScience

Sample records for age estimation

  1. Natural radioactivity, age estimation

    International Nuclear Information System (INIS)

    The life in the earth depends totally on the sun. The universe was born from great explosion, the Big Bang. Practically all the materials in the nature contain radioactive nuclides. The sources that give them origin can be categorized as: 1. Cosmogenic s 2. primordial 3. anthropogenic. The application for the first and two groups of natural radionuclides it is the age estimation. Although some of the primitive ones has application in therapy of oncological patient. 1: The three groups of age estimation methods, for nuclear phenomenons are: 1. Measure of the radioactive decline of the primitive isotopes, by accumulation of stable isotopes. 2. use of the descendants of radioactive isotopes of the families of the Uranium or of the Th. 3. Measure of the cosmogenic s isotopes

  2. Age estimation in the living

    DEFF Research Database (Denmark)

    Larsen, Sara Tangmose; Thevissen, Patrick; Lynnerup, Niels;

    2015-01-01

    A radiographic assessment of third molar development is essential for differentiating between juveniles and adolescents in forensic age estimations. As the developmental stages of third molars are highly correlated, age estimates based on a combination of a full set of third molar scores are...... statistically complicated. Transition analysis (TA) is a statistical method developed for estimating age at death in skeletons, which combines several correlated developmental traits into one age estimate including a 95% prediction interval. The aim of this study was to evaluate the performance of TA in the...... living on a full set of third molar scores. A cross sectional sample of 854 panoramic radiographs, homogenously distributed by sex and age (15.0-24.0 years), were randomly split in two; a reference sample for obtaining age estimates including a 95% prediction interval according to TA; and a validation...

  3. ESTIMATION OF AGE TRANSITION PROBABILITIES.

    Science.gov (United States)

    ZINTER, JUDITH R.

    THIS NOTE DESCRIBES THE PROCEDURES USED IN DETERMINING DYNAMOD II AGE TRANSITION MATRICES. A SEPARATE MATRIX FOR EACH SEX-RACE GROUP IS DEVELOPED. THESE MATRICES WILL BE USED AS AN AID IN ESTIMATING THE TRANSITION PROBABILITIES IN THE LARGER DYNAMOD II MATRIX RELATING AGE TO OCCUPATIONAL CATEGORIES. THREE STEPS WERE USED IN THE PROCEDURE--(1)…

  4. How to estimate dental age in paleodontology?

    Directory of Open Access Journals (Sweden)

    Vedran Šebečić

    2010-06-01

    Full Text Available Nowadays there are many methods available for dental age estimation: morphological, radiological, biochemical. Some methods require sample sectioning while other non-destructive methods are more appropriate for use in paleodontology. Children’s dental age assessment is based on phases in growth and development of the deciduous and permanent dentition, while age assessment in the adult dentition is based upon changes in the structure of hard dental tissue caused by aging. Dental age calculating software enables automated age calculations.

  5. How to estimate dental age in paleodontology?

    OpenAIRE

    Vedran Šebečić; Andrea Hoch; Maja Sabalić

    2010-01-01

    Nowadays there are many methods available for dental age estimation: morphological, radiological, biochemical. Some methods require sample sectioning while other non-destructive methods are more appropriate for use in paleodontology. Children’s dental age assessment is based on phases in growth and development of the deciduous and permanent dentition, while age assessment in the adult dentition is based upon changes in the structure of hard dental tissue caused by aging. Dental age calculati...

  6. Bayesian estimation of isotopic age differences

    International Nuclear Information System (INIS)

    Isotopic dating is subject to uncertainties arising from counting statistics and experimental errors. These uncertainties are additive when an isotopic age difference is calculated. If large, they can lead to no significant age difference by classical statistics. In many cases, relative ages are known because of stratigraphic order or other clues. Such information can be used to establish a Bayes estimate of age difference which will include prior knowledge of age order. Age measurement errors are assumed to be log-normal and a noninformative but constrained bivariate prior for two true ages in known order is adopted. True-age ratio is distributed as a truncated log-normal variate. Its expected value gives an age-ratio estimate, and its variance provides credible intervals. Bayesian estimates of ages are different and in correct order even if measured ages are identical or reversed in order. For example, age measurements on two samples might both yield 100 ka with coefficients of variation of 0.2. Bayesian estimates are 22.7 ka for age difference with a 75% credible interval of [4.4, 43.7] ka

  7. Bayesian estimation of isotopic age differences

    Energy Technology Data Exchange (ETDEWEB)

    Curl, R.L.

    1988-08-01

    Isotopic dating is subject to uncertainties arising from counting statistics and experimental errors. These uncertainties are additive when an isotopic age difference is calculated. If large, they can lead to no significant age difference by classical statistics. In many cases, relative ages are known because of stratigraphic order or other clues. Such information can be used to establish a Bayes estimate of age difference which will include prior knowledge of age order. Age measurement errors are assumed to be log-normal and a noninformative but constrained bivariate prior for two true ages in known order is adopted. True-age ratio is distributed as a truncated log-normal variate. Its expected value gives an age-ratio estimate, and its variance provides credible intervals. Bayesian estimates of ages are different and in correct order even if measured ages are identical or reversed in order. For example, age measurements on two samples might both yield 100 ka with coefficients of variation of 0.2. Bayesian estimates are 22.7 ka for age difference with a 75% credible interval of (4.4, 43.7) ka.

  8. Relative Attribute SVM+ Learning for Age Estimation.

    Science.gov (United States)

    Wang, Shengzheng; Tao, Dacheng; Yang, Jie

    2016-03-01

    When estimating age, human experts can provide privileged information that encodes the facial attributes of aging, such as smoothness, face shape, face acne, wrinkles, and bags under-eyes. In automatic age estimation, privileged information is unavailable to test images. To overcome this problem, we hypothesize that asymmetric information can be explored and exploited to improve the generalizability of the trained model. Using the learning using privileged information (LUPI) framework, we tested this hypothesis by carefully defining relative attributes for support vector machine (SVM+) to improve the performance of age estimation. We term this specific setting as relative attribute SVM+ (raSVM+), in which the privileged information enables separation of outliers from inliers at the training stage and effectively manipulates slack variables and age determination errors during model training, and thus guides the trained predictor toward a generalizable solution. Experimentally, the superiority of raSVM+ was confirmed by comparing it with state-of-the-art algorithms on the face and gesture recognition research network (FG-NET) and craniofacial longitudinal morphological face aging databases. raSVM+ is a promising development that improves age estimation, with the mean absolute error reaching 4.07 on FG-NET. PMID:25850101

  9. Epigenetic estimation of age in humpback whales.

    Science.gov (United States)

    Polanowski, Andrea M; Robbins, Jooke; Chandler, David; Jarman, Simon N

    2014-09-01

    Age is a fundamental aspect of animal ecology, but is difficult to determine in many species. Humpback whales exemplify this as they have a lifespan comparable to humans, mature sexually as early as 4 years and have no reliable visual age indicators after their first year. Current methods for estimating humpback age cannot be applied to all individuals and populations. Assays for human age have recently been developed based on age-induced changes in DNA methylation of specific genes. We used information on age-associated DNA methylation in human and mouse genes to identify homologous gene regions in humpbacks. Humpback skin samples were obtained from individuals with a known year of birth and employed to calibrate relationships between cytosine methylation and age. Seven of 37 cytosines assayed for methylation level in humpback skin had significant age-related profiles. The three most age-informative cytosine markers were selected for a humpback epigenetic age assay. The assay has an R(2) of 0.787 (P = 3.04e-16) and predicts age from skin samples with a standard deviation of 2.991 years. The epigenetic method correctly determined which of parent-offspring pairs is the parent in more than 93% of cases. To demonstrate the potential of this technique, we constructed the first modern age profile of humpback whales off eastern Australia and compared the results to population structure 5 decades earlier. This is the first epigenetic age estimation method for a wild animal species and the approach we took for developing it can be applied to many other nonmodel organisms. PMID:24606053

  10. Estimating age in black South African children.

    Science.gov (United States)

    Uys, A; Fabris-Rotelli, I; Bernitz, H

    2014-03-01

    Forensic dentists are frequently required to determine the age at death of unidentified skeletons, or to age live individuals who have no record/documentation of their chronological age. In order to be of the greatest value, the method used should have the lowest possible standard deviation and be validated for the individual's specific population group. The method most frequently used in Forensic Dentistry for the estimation of age in children, was described by Demirjian et al. The maturity standards determined were based on samples of French Canadian origin and it has been recommended by several authors that correction factors be incorporated when applying this method to different population groups. The current research was carried out on a sample of 838 black South African children. A new model for age estimation in the said population was developed, to accurately determine the chronological age from dental development. A sample of 604 black South African children was used to test the validity of the method described by Demirjian. PMID:24974518

  11. Estimating population age structure using otolith morphometrics

    DEFF Research Database (Denmark)

    Doering-Arjes, P.; Cardinale, M.; Mosegaard, Henrik

    2008-01-01

    known-age fish individuals. Here we used known-age Atlantic cod (Gadus morhua) from the Faroe Bank and Faroe Plateau stocks. Cod populations usually show quite large variation in growth rates and otolith shape. We showed that including otolith morphometrics into ageing processes has the potential to...... make ageing objective, accurate, and fast. Calibration analysis indicated that a known-age sample from the same population and environment is needed to obtain robust calibration; using a sample from a different stock more than doubles the error rate, even in the case of genetically highly related...... populations. The intercalibration method was successful but generalization from one stock to another remains problematic. The development of an otolith growth model is needed for generalization if an operational method for different populations is required in the future....

  12. Validating Age Estimates for Bocaccio Rockfish with Radiometric Dating

    OpenAIRE

    Gregor M Cailliet

    2002-01-01

    Dr. Gregor Cailliet and colleagues at California State University sought to evaluate the accuracy of aging bocaccio by counting calcified layers in the fish’s bone-like ear structures, called otoliths. Otoliths are assumed to grow in annual bands.Their work suggests that otolith-based age estimates tend to underestimate ages of older fish, compared to age estimates based on radiometric analyses. In younger fish, whose otolith layers are more distinct and easy to count, both methods provide si...

  13. Impairment of age estimation from faces in Alzheimer's disease.

    Science.gov (United States)

    Moyse, Evelyne; Bastin, Christine; Salmon, Eric; Brédart, Serge

    2015-01-01

    A prerequisite for any function in social cognition is the perception and processing of social cues. Age estimation is a skill that is used in everyday life and is fundamental in social interactions. This study evaluated whether facial age estimation is impaired in patients with mild to moderate Alzheimer's disease (AD). The current age of faces is known to have an impact on age estimation, and therefore stimuli belonging to different age groups (young, middle-aged, and older adults' faces) were used. As expected, an impairment of age estimation from faces was observed in mild to moderate AD patients. However, the profile of impairment depended on the age of faces and stage of the disease. Mild AD patients presented difficulties mainly in assessing the age of middle-aged adults. In moderate disease stage, these difficulties also affected the age estimation of young adult faces. Interestingly, AD patients remained relatively good at estimating the age of older adults' faces, compared to healthy controls. PMID:25589725

  14. Age at death estimation from bone histology in Malaysian males.

    Science.gov (United States)

    Nor, Faridah Mohd; Pastor, Robert F; Schutkowski, Holger

    2014-10-01

    Estimation of age from microscopic examination of human bone utilizes bone remodeling. This allows 2 regression equation to be determined in a specific population based on the variation in osteon turnover in different populations. The aim of this study was to provide age estimation for Malaysian males. Ground undecalcified cross sections were prepared from long limb bones of 50 deceased males aged between 21 and 78 years. Ten microstructural parameters were measured and subjected to multivariate regression analysis. Results showed that osteon count had the highest correlation with age (R = 0.43), and age was estimated to be within 10.94 years of the true value in 98% of males. Cross validation of the equation on 50 individuals showed close correspondence of true ages with estimated ages. Further studies are needed to validate and expand these results. PMID:24189643

  15. Dental Age Estimation Helps Create a New Identity.

    Science.gov (United States)

    De Angelis, Danilo; Gibelli, Daniele; Fabbri, Paolo; Cattaneo, Cristina

    2015-09-01

    Age estimation involves the reconstruction of age by biological parameters such as skeletal and dental development in minors, or reduction of pulp chamber in adults, to gain indications concerning the chronological age of the person. In most cases, it is needed in forensic scenarios to verify if the supposed age of an individual is correct; in exceptional cases, age estimation is instead required by judicial authorities to create a new identity usually in persons who do not remember who they are.This article aims at reporting the case of J. who was found in 2005 with signs of amnesia because he did not remember his name and age. After several unsuccessful attempts at identifying him, the judicial authority decided to assign a new identity, which was to be constructed according to the real biological data of the individual. The help of a forensic pathologist and a forensic odontologist was then requested, and age estimation was reached by applying methods for adults based on the physiological reduction of pulp chamber. Dental age estimation yielded a final result of approximately 31 years, which was the new age assigned to the person.This article shows a peculiar application of dental age estimation, which can be used not only to ascertain or deny supposed age, but is sometimes needed to create a new identity. PMID:26079404

  16. Human Age Estimation from Tooth Cementum and Dentin

    OpenAIRE

    Gupta, Priya; Kaur, Harshaminder; Shankari G.S., Madhu; Jawanda, Manveen Kaur; Sahi, Nita

    2014-01-01

    Background: Age estimation is an important factor in the identification of an individual in forensic science. The hard tissues of the human dentition are able to resist decay and degradation, long after other tissues are lost. This resistance has made teeth useful indicators for age calculation. Recent research has indicated that Tooth Cementum Annulations (TCA) may be used more reliably than any other morphological or histological traits of the adult skeleton, for age estimation.

  17. A Bayesian estimation of the helioseismic solar age

    CERN Document Server

    Bonanno, Alfio

    2015-01-01

    The helioseismic determination of the solar age has been a subject of several studies because it provides us with an independent estimation of the age of the solar system. We present the Bayesian estimates of the helioseismic age of the Sun, which are determined by means of calibrated solar models that employ different equations of state and nuclear reaction rates. We use 17 frequency separation ratios $r_{02}(n)=(\

  18. Evaluation of post-mortem estimated dental age versus real age: a retrospective 21-year survey

    DEFF Research Database (Denmark)

    Reppien, Kirsa; Sejrsen, Birgitte; Lynnerup, Niels

    2006-01-01

    The aim of the study was to evaluate the reliability of methods used for forensic dental age estimation. We analysed all cases over the last 21 years (1984-2004) of unidentified bodies that were examined for identification purposes (including age assessment), and of which secure identification was...... subsequently achieved. In total, the study included 51 cases and 7 different methods had been used for dental age estimation, with the Bang/Ramm and the Gustafson/Johanson methods being the most frequently applied. The age estimates had usually been recorded as 10-year intervals. Factual ages at death were in...... the range of 6-76 years, with the largest concentration of cases being in the age interval of 25-55 years (34 cases). There was good agreement between estimated age interval and factual age at death in 37/51 (72%) of the cases. In eight cases the factual age at death deviated up to +/-5 years from the...

  19. Calibrating recruitment estimates for mourning doves from harvest age ratios

    Science.gov (United States)

    Miller, David A.; Otis, David L.

    2010-01-01

    We examined results from the first national-scale effort to estimate mourning dove (Zenaida macroura) age ratios and developed a simple, efficient, and generalizable methodology for calibrating estimates. Our method predicted age classes of unknown-age wings based on backward projection of molt distributions from fall harvest collections to preseason banding. We estimated 1) the proportion of late-molt individuals in each age class, and 2) the molt rates of juvenile and adult birds. Monte Carlo simulations demonstrated our estimator was minimally biased. We estimated model parameters using 96,811 wings collected from hunters and 42,189 birds banded during preseason from 68 collection blocks in 22 states during the 2005–2007 hunting seasons. We also used estimates to derive a correction factor, based on latitude and longitude of samples, which can be applied to future surveys. We estimated differential vulnerability of age classes to harvest using data from banded birds and applied that to harvest age ratios to estimate population age ratios. Average, uncorrected age ratio of known-age wings for states that allow hunting was 2.25 (SD 0.85) juveniles:adult, and average, corrected ratio was 1.91 (SD 0.68), as determined from harvest age ratios from an independent sample of 41,084 wings collected from random hunters in 2007 and 2008. We used an independent estimate of differential vulnerability to adjust corrected harvest age ratios and estimated the average population age ratio as 1.45 (SD 0.52), a direct measure of recruitment rates. Average annual recruitment rates were highest east of the Mississippi River and in the northwestern United States, with lower rates between. Our results demonstrate a robust methodology for calibrating recruitment estimates for mourning doves and represent the first large-scale estimates of recruitment for the species. Our methods can be used by managers to correct future harvest survey data to generate recruitment estimates for use in

  20. Discriminating Projections for Estimating Face Age in Wild Images

    Energy Technology Data Exchange (ETDEWEB)

    Tokola, Ryan A [ORNL; Bolme, David S [ORNL; Ricanek, Karl [ORNL; Barstow, Del R [ORNL; Boehnen, Chris Bensing [ORNL

    2014-01-01

    We introduce a novel approach to estimating the age of a human from a single uncontrolled image. Current face age estimation algorithms work well in highly controlled images, and some are robust to changes in illumination, but it is usually assumed that images are close to frontal. This bias is clearly seen in the datasets that are commonly used to evaluate age estimation, which either entirely or mostly consist of frontal images. Using pose-specific projections, our algorithm maps image features into a pose-insensitive latent space that is discriminative with respect to age. Age estimation is then performed using a multi-class SVM. We show that our approach outperforms other published results on the Images of Groups dataset, which is the only age-related dataset with a non-trivial number of off-axis face images, and that we are competitive with recent age estimation algorithms on the mostly-frontal FG-NET dataset. We also experimentally demonstrate that our feature projections introduce insensitivity to pose.

  1. Age estimation and validation for South Pacific albacore Thunnus alalunga.

    Science.gov (United States)

    Farley, J H; Williams, A J; Clear, N P; Davies, C R; Nicol, S J

    2013-05-01

    Validated estimates of age are presented for albacore Thunnus alalunga, sampled from a large part of the south-western Pacific Ocean, based on counts of annual opaque growth zones from transverse sections of otoliths. Counts of daily increments were used to estimate the location of the first opaque growth zone, which was completed before the first assumed birthday. The periodicity of opaque zones was estimated by marginal increment analysis and an oxytetracycline mark-recapture experiment. Both validation methods indicated that opaque zones formed over the austral summer and were completed by autumn to winter (April to August). The direct comparison of age estimates obtained from otoliths and dorsal-fin spines of the same fish indicated bias, which was assumed to be due to poor increment clarity and resorption of early growth zones in spines, resulting in imprecise age estimates. As such, age estimates from otoliths are considered to be more accurate than those from spines for T. alalunga. This is consistent with results for a growing number of tropical and temperate tuna Thunnini species. It is recommend that validated counts of annual growth zones from sectioned otoliths is used as the preferred method for estimating age-based parameters for assessment and management advice for these important stocks. PMID:23639152

  2. Age-dependent forest carbon sink: Estimation via inverse modeling

    Science.gov (United States)

    Zhou, Tao; Shi, Peijun; Jia, Gensuo; Dai, Yongjiu; Zhao, Xiang; Shangguan, Wei; Du, Ling; Wu, Hao; Luo, Yiqi

    2015-12-01

    Forests have been recognized to sequester a substantial amount of carbon (C) from the atmosphere. However, considerable uncertainty remains regarding the magnitude and time course of the C sink. Revealing the intrinsic relationship between forest age and C sink is crucial for reducing uncertainties in prediction of forest C sink potential. In this study, we developed a stepwise data assimilation approach to combine a process-based Terrestrial ECOsystem Regional model, observations from multiple sources, and stochastic sampling to inversely estimate carbon cycle parameters including carbon sink at different forest ages for evergreen needle-leaved forests in China. The new approach is effective to estimate age-dependent parameter of maximal light-use efficiency (R2 = 0.99) and, accordingly, can quantify a relationship between forest age and the vegetation and soil C sinks. The estimated ecosystem C sink increases rapidly with age, peaks at 0.451 kg C m-2 yr-1 at age 22 years (ranging from 0.421 to 0.465 kg C m-2 yr-1), and gradually decreases thereafter. The dynamic patterns of C sinks in vegetation and soil are significantly different. C sink in vegetation first increases rapidly with age and then decreases. C sink in soil, however, increases continuously with age; it acts as a C source when the age is less than 20 years, after which it acts as a sink. For the evergreen needle-leaved forest, the highest C sink efficiency (i.e., C sink per unit net primary productivity) is approximately 60%, with age between 11 and 43 years. Overall, the inverse estimation of carbon cycle parameters can make reasonable estimates of age-dependent C sequestration in forests.

  3. Age estimation using maxillary central incisors: A radiographic study

    Directory of Open Access Journals (Sweden)

    Nitin Agarwal

    2012-01-01

    Full Text Available Background: In the field of forensic dentistry, secondary changes in teeth with advancing age have been used as reliable predictors of age in various studies. Aim: The purpose of the present study was to present a method for assessing the chronological age based on the relationship between age and morphological parameters of maxillary central incisors. Materials and Methods: Fifty subjects between 20-70 years of age were included in the study. Intraoral periapical radiographs were taken in relation to maxillary central incisors using paralleling technique. The following measurements were recorded: lengths of tooth, pulp, root and width of root and pulp at three different points. Regression formulas were used to calculate the dental age. Results: The mean estimated age showed no statistically significant difference from the actual mean age (P > 0.05. Also, maximum difference was seen for root length variable (-1.035 ± 1.86 years.

  4. Age synthesis and estimation via faces: a survey.

    Science.gov (United States)

    Fu, Yun; Guo, Guodong; Huang, Thomas S

    2010-11-01

    Human age, as an important personal trait, can be directly inferred by distinct patterns emerging from the facial appearance. Derived from rapid advances in computer graphics and machine vision, computer-based age synthesis and estimation via faces have become particularly prevalent topics recently because of their explosively emerging real-world applications, such as forensic art, electronic customer relationship management, security control and surveillance monitoring, biometrics, entertainment, and cosmetology. Age synthesis is defined to rerender a face image aesthetically with natural aging and rejuvenating effects on the individual face. Age estimation is defined to label a face image automatically with the exact age (year) or the age group (year range) of the individual face. Because of their particularity and complexity, both problems are attractive yet challenging to computer-based application system designers. Large efforts from both academia and industry have been devoted in the last a few decades. In this paper, we survey the complete state-of-the-art techniques in the face image-based age synthesis and estimation topics. Existing models, popular algorithms, system performances, technical difficulties, popular face aging databases, evaluation protocols, and promising future directions are also provided with systematic discussions. PMID:20847387

  5. Estimation of gestational age from gall-bladder length.

    Science.gov (United States)

    Udaykumar, K; Udaykumar, Padmaja; Nagesh, K R

    2016-01-01

    Establishing a precise duration of gestation is vital in situations such as infanticide and criminal abortions. The present study attempted to estimate the gestational age of the foetus from gall-bladder length. Foetuses of various gestational age groups were dissected, and the length of the gall bladder was measured. The results were analysed, and a substantial degree of correlation was statistically confirmed. This novel method is helpful when the foetus is fragmented, putrefied or eviscerated, where this method can be used as an additional parameter to improve the accuracy of foetal age estimation. PMID:25990829

  6. Age estimation for forensic purposes in Italy: ethical issues.

    Science.gov (United States)

    Focardi, Martina; Pinchi, Vilma; De Luca, Federica; Norelli, Gian-Aristide

    2014-05-01

    Age assessment in children and young adults is a relevant medicolegal issue due to the gradual increase of persons devoid of proper identification documents in European countries. Because of the illegal immigration and growing crime rates among children and adolescents, age estimation for forensic purposes is often required. The scientific research and the extensive experience of forensic experts in the last decades focused on the use of radiographic methods addressed to evaluate the degree of skeletal or dental development as the most accurate parameters to estimate the chronological age of children and adolescents. This paper analyzes the ethical issues related to age estimation procedures based on radiographic methods, showing how the ethical principles of beneficence, nonmalevolence, justice, and autonomy may be guaranteed during the execution of the age assessment in forensic practice. The procedure might be conducted in accordance with international guidelines and protocols, though they need a higher homogenization and standardization. A strong collaboration between various scientific societies of professionals (forensic odontologists, forensic pathologists, forensic anthropologist, radiologists, pediatricians, and psychologists), who have been involved in age estimation for years, is needed to reach this goal. PMID:24633466

  7. Non-destructive methods to estimate physical aging of plywood

    OpenAIRE

    Bobadilla Maldonado, Ignacio; Santirso, María Cristina; Herrero Giner, Daniel; Esteban Herrero, Miguel; Iñiguez Gonzalez, Guillermo

    2011-01-01

    This paper studies the relationship between aging, physical changes and the results of non-destructive testing of plywood. 176 pieces of plywood were tested to analyze their actual and estimated density using non-destructive methods (screw withdrawal force and ultrasound wave velocity) during a laboratory aging test. From the results of statistical analysis it can be concluded that there is a strong relationship between the non-destructive measurements carried out, and the decline in the phys...

  8. Estimation of age from development and eruption of teeth

    Directory of Open Access Journals (Sweden)

    B. S. Manjunatha

    2014-01-01

    Full Text Available The developing dentition is used to assess maturity and estimate the age in many disciplines including anthropology, archeology, forensic science, pediatric dentistry and orthodontics. There is evidence that dental development is less effected than skeletal development by malnutrition and hormonal disorders. There are two methods of dental age assessment, radiographically and by clinically visualization of eruption of teeth. The clinical method to assess dental age is based on the emergence of teeth in the mouth. This method is more suitable since it does not require any special equipment, expertise and is more economical. Tooth formation is the best choice for estimating the age as variations are less as compared to other development factors. Eruption of teeth is one of the changes observed easily among the various dynamic changes that occur from the formation of teeth to the final shedding of teeth. The times of eruption of teeth are fairly constant and this can be made use of in ascertaining the average age of eruption of the tooth. Assessment of age of an individual by examination of teeth is one of the accepted methods of age determination.

  9. An own-age bias in age estimation of faces in children and adults.

    OpenAIRE

    Moyse, Evelyne; Brédart, Serge

    2010-01-01

    The aim of the present study was to assess the occurence of an own-age bias on age estimation performance (better performance for faces from the same age range as that of the beholder) by using an experimental design inspired from research on the own-race effect. The age of participants (10 to 14 year old children and 20 to 30 year old adults) was an independent factor that was crossed with the age of the stimuli (faces of 10 to 14 year old children and faces of 20 to 30 year old adults), the...

  10. Secondary Forest Age and Tropical Forest Biomass Estimation Using TM

    Science.gov (United States)

    Nelson, R. F.; Kimes, D. S.; Salas, W. A.; Routhier, M.

    1999-01-01

    The age of secondary forests in the Amazon will become more critical with respect to the estimation of biomass and carbon budgets as tropical forest conversion continues. Multitemporal Thematic Mapper data were used to develop land cover histories for a 33,000 Square kM area near Ariquemes, Rondonia over a 7 year period from 1989-1995. The age of the secondary forest, a surrogate for the amount of biomass (or carbon) stored above-ground, was found to be unimportant in terms of biomass budget error rates in a forested TM scene which had undergone a 20% conversion to nonforest/agricultural cover types. In such a situation, the 80% of the scene still covered by primary forest accounted for over 98% of the scene biomass. The difference between secondary forest biomass estimates developed with and without age information were inconsequential relative to the estimate of biomass for the entire scene. However, in futuristic scenarios where all of the primary forest has been converted to agriculture and secondary forest (55% and 42% respectively), the ability to age secondary forest becomes critical. Depending on biomass accumulation rate assumptions, scene biomass budget errors on the order of -10% to +30% are likely if the age of the secondary forests are not taken into account. Single-date TM imagery cannot be used to accurately age secondary forests into single-year classes. A neural network utilizing TM band 2 and three TM spectral-texture measures (bands 3 and 5) predicted secondary forest age over a range of 0-7 years with an RMSE of 1.59 years and an R(Squared) (sub actual vs predicted) = 0.37. A proposal is made, based on a literature review, to use satellite imagery to identify general secondary forest age groups which, within group, exhibit relatively constant biomass accumulation rates.

  11. Dental age estimation using Willems method: A digital orthopantomographic study

    Directory of Open Access Journals (Sweden)

    Rezwana Begum Mohammed

    2014-01-01

    Full Text Available In recent years, age estimation has become increasingly important in living people for a variety of reasons, including identifying criminal and legal responsibility, and for many other social events such as a birth certificate, marriage, beginning a job, joining the army, and retirement. Objectives: The aim of this study was to assess the developmental stages of left seven mandibular teeth for estimation of dental age (DA in different age groups and to evaluate the possible correlation between DA and chronological age (CA in South Indian population using Willems method. Materials and Methods: Digital Orthopantomogram of 332 subjects (166 males, 166 females who fit the study and the criteria were obtained. Assessment of mandibular teeth (from central incisor to the second molar on left quadrant development was undertaken and DA was assessed using Willems method. Results and Discussion: The present study showed a significant correlation between DA and CA in both males (r = 0.71 and females (r = 0.88. The overall mean difference between the estimated DA and CA for males was 0.69 ± 2.14 years (P 0.05. Willems method underestimated the mean age of males by 0.69 years and females by 0.08 years and showed that females mature earlier than males in selected population. The mean difference between DA and CA according to Willems method was 0.39 years and is statistically significant (P < 0.05. Conclusion: This study showed significant relation between DA and CA. Thus, digital radiographic assessment of mandibular teeth development can be used to generate mean DA using Willems method and also the estimated age range for an individual of unknown CA.

  12. Fetal age estimation using MSCT scans of deciduous tooth germs.

    Science.gov (United States)

    Minier, Marie; Maret, Delphine; Dedouit, Fabrice; Vergnault, Marion; Mokrane, Fathima-Zohra; Rousseau, Hervé; Adalian, Pascal; Telmon, Norbert; Rougé, Daniel

    2014-01-01

    Evaluation of fetal age is an essential element in many fields such as anthropology, odontology, paleopathology, and forensic sciences. This study examines the correlation between fetal age, femoral diaphyseal length (considered as the gold standard), and deciduous tooth germs of fetuses aged 22 to 40 weeks amenorrhea (WA) based on computed tomography (MSCT) reconstructions. Qualitative and quantitative studies of femoral and deciduous tooth germ lengths were performed on 81 fetuses (39 females and 42 males). R software was used for statistical analyses. Intra-observer and inter-observer variabilities and the interclass correlation coefficient (ICC) were calculated. Correlation coefficients (R (2)) and linear regression equations were calculated. Intra- and inter-observer variabilities were very satisfactory (intra-observer ICC ≥ 0.96, inter-observer ICC ≥ 0.95). Femoral length was significantly correlated with age (R (2) = 0.9). The correlation coefficient between age and height, width, and dental volume was R (2) ≥ 0.73. Tooth germs were good indicators of fetal age. Our method appears to be reliable and reproducible, and the results of this study agreed with those of the literature. The dental formula provided a precise estimation of fetal age between 25 and 32 WA. Tooth germs were reliable indicators of fetal age, and multislice computed tomography was shown to be an innovative and reliable technology for this purpose. PMID:23828625

  13. Relationship Between Mitochondrial DNA Mutations and Aging. Estimation of Age-at-death.

    Science.gov (United States)

    Zapico, Sara C; Ubelaker, Douglas H

    2016-04-01

    Some studies have pointed to the relationship between mitochondrial DNA (mtDNA) mutations and age in different tissues, which are potentially interesting in aging research and in forensic identification because they could help to improve the estimation of age-at-death. The present study aims to evaluate the mutations in mtDNA from dentin and pulp and their relation with age. Healthy erupted third molars were extracted from individuals from two Spanish populations, aged 20-70. When analyzing the amplification of hypervariable region 2 of the mtDNA by real-time polymerase chain reaction, a negative strong linear correlation was found between the mtDNA amplification and age in dentin from both populations. In contrast, a significant correlation between mtDNA amplification and age in pulp was not discovered, probably due to the majority of the mitochondria are placed in dentin. A difference in mtDNA damage between these two populations was also detected, indicating the role of ancestry as a component. The findings from this research enrich the current studies related to aging and mitochondrial damage and provide a new quantitative tool for estimating the age-at-death that, in combination with traditional age markers, could improve identification accuracy in forensic cases. PMID:26286606

  14. Estimating age conditional probability of developing disease from surveillance data

    Directory of Open Access Journals (Sweden)

    Fay Michael P

    2004-07-01

    Full Text Available Abstract Fay, Pfeiffer, Cronin, Le, and Feuer (Statistics in Medicine 2003; 22; 1837–1848 developed a formula to calculate the age-conditional probability of developing a disease for the first time (ACPDvD for a hypothetical cohort. The novelty of the formula of Fay et al (2003 is that one need not know the rates of first incidence of disease per person-years alive and disease-free, but may input the rates of first incidence per person-years alive only. Similarly the formula uses rates of death from disease and death from other causes per person-years alive. The rates per person-years alive are much easier to estimate than per person-years alive and disease-free. Fay et al (2003 used simple piecewise constant models for all three rate functions which have constant rates within each age group. In this paper, we detail a method for estimating rate functions which does not have jumps at the beginning of age groupings, and need not be constant within age groupings. We call this method the mid-age group joinpoint (MAJ model for the rates. The drawback of the MAJ model is that numerical integration must be used to estimate the resulting ACPDvD. To increase computational speed, we offer a piecewise approximation to the MAJ model, which we call the piecewise mid-age group joinpoint (PMAJ model. The PMAJ model for the rates input into the formula for ACPDvD described in Fay et al (2003 is the current method used in the freely available DevCan software made available by the National Cancer Institute.

  15. Age estimation of bloodstains using smartphones and digital image analysis.

    Science.gov (United States)

    Thanakiatkrai, Phuvadol; Yaodam, Alisa; Kitpipit, Thitika

    2013-12-10

    Recent studies on bloodstains have focused on determining the time since deposition of bloodstains, which can provide useful temporal information to forensic investigations. This study is the first to use smartphone cameras in combination with a truly low-cost illumination system as a tool to estimate the age of bloodstains. Bloodstains were deposited on various substrates and photographed with a smartphone camera. Three smartphones (Samsung Galaxy S Plus, Apple iPhone 4, and Apple iPad 2) were compared. The environmental effects - temperature, humidity, light exposure, and anticoagulant - on the bloodstain age estimation process were explored. The color values from the digital images were extracted and correlated with time since deposition. Magenta had the highest correlation (R(2)=0.966) and was used in subsequent experiments. The Samsung Galaxy S Plus was the most suitable smartphone as its magenta decreased exponentially with increasing time and had highest repeatability (low variation within and between pictures). The quantifiable color change observed is consistent with well-established hemoglobin denaturation process. Using a statistical classification technique called Random Forests™, we could predict bloodstain age accurately up to 42 days with an error rate of 12%. Additionally, the age of forty blind stains were all correctly predicted, and 83% of mock casework samples were correctly classified. No within- and between-person variations were observed (p>0.05), while smartphone camera, temperature, humidity, and substrate color influenced the age determination process in different ways. Our technique provides a cheap, rapid, easy-to-use, and truly portable alternative to more complicated analysis using specialized equipment, e.g. spectroscopy and HPLC. No training is necessary with our method, and we envision a smartphone application that could take user inputs of environmental factors and provide an accurate estimate of bloodstain age. PMID:24314532

  16. Computerized geometric features of carpal bone for bone age estimation

    Institute of Scientific and Technical Information of China (English)

    Chi-Wen Hsieh; Tai-Lang Jong; Yi-Hong Chou; Chui-Mei Tiu

    2007-01-01

    Background Bone age development is one of the significant indicators depicting the growth status of children.However, bone age assessment is an heuristic and tedious work for pediatricians. We developed a computerized bone age estimation system based on the analysis of geometric features of carpal bones.Methods The geometric features of carpals were extracted and analyzed to judge the bone age of children by computerized shape and area description. Four classifiers, linear, nearest neighbor, back-propagation neural network,and radial basis function neural network, were adopted to categorize bone age. Principal component and discriminate analyses were employed to improve assorting accuracy.Results The hand X-ray films of 465 boys and 444 girls served as our database. The features were extracted from carpal bone images, including shape, area, and sequence. The proposed normalization area ratio method was effective in bone age classification by simulation. Besides, features statistics showed similar results between the standard of the Greulich and Pyle atlas and our database.Conclusions The bone area has a higher discriminating power to judge bone age. The ossification sequence of trapezium and trapezoid bones between Taiwanese and the atlas of the GP method is quite different. These results also indicate that carpal bone assessment with classification of neural networks can be correct and practical.

  17. Role of adenohypophyseal mixed cell-follicles in age estimation.

    Directory of Open Access Journals (Sweden)

    Ishikawa T

    2003-04-01

    Full Text Available In this study we used paraffin-embedded human pituitary obtained from 248 autopsy cases and identified mixed cell follicles by the immunohistochemical method. We examined the number and size of the mixed cell follicles, and the ratio of each component cell of these follicles, in the anterior pituitary at various age groups. The number of follicles increased with age, and the size of the follicles also tended to enlarge with age. Statistical analysis showed that a high correlation existed between age and the number or the size of the mixed cell-follicles formed by various adenohypophyseal cells. In addition, when the proportions of the different cell types that formed the follicles were examined, sex differences were observed with aging for the GH cells, the PRL cells, and the gonadotroph (GTH cells, while no changes were observed with aging in both men and women for the ACTH cells and TSH cells. These results indicate that the number, size, and ratio of each component cell of follicles in the anterior pituitary are adequately applicable for the purpose of age estimation in routine forensic medicine.

  18. Lifetime estimation of zirconia ceramics by linear ageing kinetics

    International Nuclear Information System (INIS)

    Up to now, the ageing kinetics of zirconia ceramics were mainly derived from the sigmoidal evolution of the surface phase transformation as a function of time, as quantified by means of X-ray diffraction (XRD). However, the transformation propagation into the material should be better to monitor the ageing kinetics. In this work, μ-Raman spectroscopy was used to quantitatively measure the transformation profiles in depth as a function of ageing time at 160 °C, 140 °C, 134 °C and 110 °C. A linear relationship between the transformed depth and the ageing time was observed for all investigated yttria stabilized tetragonal zirconia polycrystals (3Y-TZP). Furthermore, the μ-Raman investigation of residual stresses in the subsurface of aged 3Y-TZPs showed that the highest tensile stress was located just ahead of the transformation front, indicating the key responsibility of stress accumulation for transformation front propagating into the material. Moreover, the linear kinetics of the transformation propagation were more accurate to calculate the apparent activation energy of the ageing process and allowed a more straightforward estimation of the lifetime of 3Y-TZP at body temperature, as compared to the conventional ageing kinetic parameters obtained from the surface transformation analysis by XRD

  19. Digital approach for measuring dentin translucency in forensic age estimation

    Directory of Open Access Journals (Sweden)

    Simranjit Singh

    2013-01-01

    Full Text Available Background: Dentin translucency is best suited for age estimation not only in terms of accuracy but also in terms of simplicity. Conventionally, translucency has been measured using calipers. Computer-based methods have been proposed for the same, although these required the use of custom-built software programs. Objectives: The objectives of the study were to use a simple digital method to measure dentinal translucency on sectioned teeth and to compare digital measurements to conventionally obtained translucency measurements. Materials and Methods: Fifty extracted permanent teeth were collected and were sectioned to 250 μm. Translucency measurements were obtained using the digital method and compared with those obtained using a caliper. Results: Correlation coefficients of translucency measurements to age were statistically significant for both methods (P < 0.001, and marginally higher for the conventional approach (r = 0.4671. Application of derived linear regression equations on an independent sample (n = 10 revealed a similar ability of both the methods to assess age to within ±5 years of the actual age. Conclusion: The translucency measurements obtained by the two methods were very similar, with no clear superiority of one method over the other. Hence, further studies on a large scale are warranted to determine which method is more reliable to estimate the age.

  20. Aging Study and Lifetime Estimation of Transformer Mineral Oil

    Directory of Open Access Journals (Sweden)

    Mohammad R. Meshkatoddini

    2008-01-01

    Full Text Available Problem statement: Power transformer is the most expensive equipment in electrical network; and the mineral oil has the main roles of insulating and cooling in it. Oil is subjected to the degradation because of the ageing, high temperature and chemical reactions such as the oxidation. Then the oil condition has to be checked regularly and reclaimed or replaced when necessary, to avoid the sudden failure of the transformer. It will be very desirable also if we can predict the transformer oil remaining lifetime, from time to time. Approach: An experimental study was accomplished on the used oil specimens coming from several power transformers of various ages, working in Iranian power network, to recognize the correlation between the real age of the oil and the rate of its different characteristics and to know the most appropriate property which can represent its ageing. Accelerated aging experiments were accomplished on oil specimens at different temperatures. Furthermore a method for estimation of the remaining lifetime of the oil, using Arrhenius law, was employed. Results: According to our experiments, it was verified that, by using Celsius degrees and natural logarithm, the Arrhenius law can be applied properly to the thermal degradation phenomena of the oil. Conclusion: It was shown that the presented method can be used to study the degradation of transformer mineral oil and to estimate its remaining lifetime.

  1. Estimating Twin Pair Concordance for Age of Onset

    DEFF Research Database (Denmark)

    Scheike, Thomas H; Hjelmborg, Jacob B; Holst, Klaus K

    2015-01-01

    Twin and family data provide a key source for evaluating inheritance of specific diseases. A standard analysis of such data typically involves the computation of prevalences and different concordance measures such as the casewise concordance, that is the probability that one twin has the disease...... develop the disease. The aim of this contribution is to show that the standard casewise concordance and standard prevalence estimators do not work in general for age-of-onset data. We show how one can in fact do something easy and simple even with censored data. The key is to take age into account when...

  2. Similarity estimators for irregular and age uncertain time series

    Directory of Open Access Journals (Sweden)

    K. Rehfeld

    2013-09-01

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

  3. Age estimation from physiological changes of teeth: A reliable age marker?

    Directory of Open Access Journals (Sweden)

    Nishant Singh

    2014-01-01

    Full Text Available Background: Age is an essential factor in establishing the identity of a person. Teeth are one of the most durable and resilient part of skeleton. Gustafson (1950 suggested the use of six retrogressive dental changes that are seen with increasing age. Aim: The aim of the study was to evaluate the results and to check the reliability of modified Gustafson′s method for determining the age of an individual. Materials and Methods: Total 70 patients in the age group of 20-65 years, undergoing extraction were included in this present work. The ground sections of extracted teeth were prepared and examined under the microscope. Modified Gustafson′s criteria were used for the estimation of age. Degree of attrition, root translucency, secondary dentin deposition, cementum apposition, and root resorption were measured. A linear regression formula was obtained using different statistical equations in a sample of 70 patients. Results: The mean age difference of total 70 cases studied was ±2.64 years. Difference of actual and calculated age was significant and was observed at 5% level of significance, that is, t-cal > t-tab (t-cal = 7.72. P < 0.05, indicates that the results were statistically significant. Conclusion: The present study concludes that Gustafson′s method is a reliable method for age estimation with some proposed modifications.

  4. Fetal age estimation using MSCT scans of the mandible.

    Science.gov (United States)

    Minier, Marie; Dedouit, Fabrice; Maret, Delphine; Vergnault, Marion; Mokrane, Fathima-Zohra; Rousseau, Hervé; Adalian, Pascal; Telmon, Norbert; Rougé, Daniel

    2014-05-01

    The purpose of this study was to examine a documented fetal collection, to carry out morphometric analysis of femoral length and of the mandible, and to develop diagnostic standards for estimating fetal age at death based on multislice computed tomography (MSCT) reconstructions. The sample was composed of 81 fetuses, whose ages were recorded in weeks of amenorrhea (WA) between 20 to 40 WA. The measurements made were femoral length (FL) and six distances and four angles of the mandible. Femoral length was measured in 81 fetuses (39 females and 42 males). Morphometric study of the mandible was carried out in 65 fetuses (31 females and 34 males), as the mandible was missing in 16 fetuses. R software was used for statistical analyses. Coefficient correlation (R(2)) and linear regression formulas were calculated. Intra-observer and inter-observer variabilities were very satisfactory (intra-class correlation coefficient ≥0.95). Our method appears to be reliable and reproducible. Femoral length was most strongly correlated with age (R(2) = 0.9). The measurement of six distances and four mandible angles from four landmark positions showed a correlation similar to the femoral length correlation (R(2) ≥ 0.72). The results of this study agreed with those of the literature. We conclude that the mandible is a reliable indicator for estimating fetal age at death. Moreover, MSCT has been shown to be an innovative and reliable technology for this purpose. PMID:24213737

  5. Accuracy of age estimation of radiographic methods using developing teeth.

    Science.gov (United States)

    Maber, M; Liversidge, H M; Hector, M P

    2006-05-15

    Developing teeth are used to assess maturity and estimate age in a number of disciplines, however the accuracy of different methods has not been systematically investigated. The aim of this study was to determine the accuracy of several methods. Tooth formation was assessed from radiographs of healthy children attending a dental teaching hospital. The sample was 946 children (491 boys, 455 girls, aged 3-16.99 years) with similar number of children from Bangladeshi and British Caucasian ethnic origin. Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994; A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227; A. Demirjian, H. Goldstein, New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411-421], Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103-170]. Dental age was calculated for each method, including an adaptation of Demirjian's method with updated scoring [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895]. The mean difference (+/-S.D. in years) between dental and real age was calculated for each method and in the case of Haavikko, each tooth type; and tested using t-test. Mean difference was also calculated for the age group 3-13.99 years for Haavikko (mean and individual teeth). Results show that the most accurate method was by Willems [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci

  6. Age estimation among Brazilians: Younger or older than 18?

    Science.gov (United States)

    Deitos, Alexandre Raphael; Costa, Claudio; Michel-Crosato, Edgard; Galić, Ivan; Cameriere, Roberto; Biazevic, Maria Gabriela Haye

    2015-07-01

    The age estimation of living or dead individuals is an important part of forensic science because it can be used in various situations, including mass disasters, or for civil or criminal reasons, such as adoption or asylum. Teeth play a major role in this context because they are more resistant than bones in extreme environmental conditions and their development is hardly affected by exogenous or endogenous factors. Because the third molars (3rdM) are still in development from the age of 14, they are useful for determining whether an individual has reached the legal age of 18 years. This study aims to verify the method of Cameriere et al. (2008) in Brazil to discriminate whether an individual is under or over 18 years from the maturity index of the 3rdM (I3m). The analysis of 444 panoramic radiographs resulted in a sensitivity of 78.3%, a specificity of 85.1% and a correct classification of 87%. Significant differences in sexual dimorphism in the early mineralization of males were found only for the average age with I3m ≥ 0.08, except for the range (0.7, 0.9). Due to the high miscegenation ratio of the Brazilian population the ancestry was not one of the studied variables. The method is suitable for estimating adulthood for forensic purposes in Brazil, although it must be applied carefully and judiciously. We recommend a combination of several methods that are available to increase accuracy as well as the establishment of different parameters that are likely to determine whether a person is more or less than 18 years of age, depending on the different legal requirements, whether civil or criminal. PMID:26048509

  7. Estimating the age of alleles by use of intraallelic variability

    Energy Technology Data Exchange (ETDEWEB)

    Slatkin, M.; Rannala, B. [Univ of California, Berkeley, CA (United States)

    1997-02-01

    A method is presented for estimating the age of an allele by use of its frequency and the extent of variation among different copies. The method uses the joint distribution of the number of copies in a population sample and the coalescence times of the intraallelic gene genealogy conditioned on the number of copies. The linear birth-death process is used to approximate the dynamics of a rare allele in a finite population. A maximum-likelihood estimate of the age of the allele is obtained by Monte Carlo integration over the coalescence times. The method is applied to two alleles at the cystic fibrosis (CFTR) locus, {Delta}F508 and G542X, for which intraallelic variability at three intronic microsatellite loci has been examined. Our results indicate that G542X is somewhat older than {Delta}F508. Although absolute estimates depend on the mutation rates at the microsatellite loci, our results support the hypothesis that {Delta}F508 arose <500 generations ({approx}10,000 years) ago. 32 refs., 4 figs.

  8. Dental Care Demand: Age-Specific Estimates for the Population 65 Years of Age and Over

    OpenAIRE

    Conrad, Douglas A

    1983-01-01

    This paper derives estimates of the demand for dental care among the U.S. population 65 years of age and over. The analysis is unique in that it focuses on a segment of the population with particular relevance to future policy regarding dental insurance coverage and distinguishes determinants of dental care demand by type of service. The empirical estimates suggest that the use of dental service by elderly persons does respond to price changes and that price-elasticity of demand varies signif...

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

    Science.gov (United States)

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

    2008-01-01

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

  10. Precise age estimation from different ageing structures in the striped snakehead, Channa striata (Bloch,1793, collected from the river Ganga

    Directory of Open Access Journals (Sweden)

    Salman Khan

    2015-11-01

    Full Text Available In Channa striata (N=156; TL=17-60cm sampled from the river Ganga, the annuli laid on different ageing structures such as otoliths (whole and sectioned, scales, opercular bone and vertebrae were observed for age estimation. Standard procedures were followed to prepare and study the age structures. Age estimates obtained from different hard structures were analysed to calculate the parameters for precise age estimation viz., APE, CV and PA. The sectioned otoliths showed the highest (89.9% percentage of agreement between readers while least average percent error (1.20% and coefficient of variation (3.81% values between two readers. Thus sectioned otoliths were considered to be the most suitable method for estimating age in C. striata. When sectioned otoliths were compared with other bony structures, the highest percent agreement and lowest average percent error and coefficient of variation values were found between sectioned otoliths and whole otoliths age estimates.

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

    Science.gov (United States)

    Skoog Waller, Sara; Eriksson, Mårten; Sörqvist, Patrik

    2015-01-01

    Cognitive hearing science is mainly about the study of how cognitive factors contribute to speech comprehension, but cognitive factors also partake in speech processing to infer non-linguistic information from speech signals, such as the intentions of the talker and the speaker's age. Here, we report two experiments on age estimation by "naïve" listeners. The aim was to study how speech rate influences estimation of speaker age by comparing the speakers' natural speech rate with increased or decreased speech rate. In Experiment 1, listeners were presented with audio samples of read speech from three different speaker age groups (young, middle aged, and old adults). They estimated the speakers as younger when speech rate was faster than normal and as older when speech rate was slower than normal. This speech rate effect was slightly greater in magnitude for older (60-65 years) speakers in comparison with younger (20-25 years) speakers, suggesting that speech rate may gain greater importance as a perceptual age cue with increased speaker age. This pattern was more pronounced in Experiment 2, in which listeners estimated age from spontaneous speech. Faster speech rate was associated with lower age estimates, but only for older and middle aged (40-45 years) speakers. Taken together, speakers of all age groups were estimated as older when speech rate decreased, except for the youngest speakers in Experiment 2. The absence of a linear speech rate effect in estimates of younger speakers, for spontaneous speech, implies that listeners use different age estimation strategies or cues (possibly vocabulary) depending on the age of the speaker and the spontaneity of the speech. Potential implications for forensic investigations and other applied domains are discussed. PMID:26236259

  12. So You Think You Look Young? Matching Older Adults' Subjective Ages with Age Estimations Provided by Younger, Middle-Aged, and Older Adults

    Science.gov (United States)

    Kotter-Gruhn, Dana; Hess, Thomas M.

    2012-01-01

    Perceived age plays an important role in the context of age identity and social interactions. To examine how accurate individuals are in estimating how old they look and how old others are, younger, middle-aged, and older adults rated photographs of older target persons (for whom we had information about objective and subjective age) in terms of…

  13. Estimating The Age-Productivity Profile Using Lifetime Earnings

    OpenAIRE

    Kotlikoff, Laurence J.

    1988-01-01

    Understanding how productivity varies with age is important for a variety of reasons. A decline in productivity with age implies that aging societies must increasingly depend on the labor supply of the young and middle age. It also means that policies designed to keep the elderly in the work force, while potentially good for the elderly, may decrease overall productivity. A third implication is that, absent government intervention, employers may not be willing to hire the elderly for the same...

  14. Application of a novel method for age estimation of a baleen whale and a porpoise

    DEFF Research Database (Denmark)

    Nielsen, Nynne H.; Garde, Eva; Heide-Jørgensen, Mads Peter;

    2013-01-01

    Eyeballs from 121 fin whales (Balaenoptera physalus) and 83 harbor porpoises (Phocoena phocoena) were used for age estimation using the aspartic acid racemization (AAR) technique. The racemization rate (kAsp) for fin whales was established from 15 fetuses (age 0) and 15 adult whales where age was...... ± 0.0018) were estimated, which is considerably higher than found for other cetaceans. Correlation between chosen age estimates from AAR and GLG counts indicated that AAR might be an alternative method for estimating age in marine mammals....

  15. 76 FR 37314 - Estimates of the Voting Age Population for 2010

    Science.gov (United States)

    2011-06-27

    ... Office of the Secretary Estimates of the Voting Age Population for 2010 AGENCY: Office of the Secretary, Commerce. ACTION: General Notice Announcing Population Estimates. SUMMARY: This notice announces the voting age population estimates as of July 1, 2010, for each state and the District of Columbia. We...

  16. 78 FR 6289 - Estimates of the Voting Age Population for 2012

    Science.gov (United States)

    2013-01-30

    ... Office of the Secretary Estimates of the Voting Age Population for 2012 AGENCY: Office of the Secretary, Commerce. ] ACTION: General notice announcing population estimates. SUMMARY: This notice announces the voting age population estimates as of July 1, 2012, for each state and the District of Columbia. We...

  17. 75 FR 4343 - Estimates of the Voting Age Population for 2009

    Science.gov (United States)

    2010-01-27

    ... Office of the Secretary Estimates of the Voting Age Population for 2009 AGENCY: Office of the Secretary, Commerce. ACTION: General Notice Announcing Population Estimates. SUMMARY: This notice announces the voting age population estimates as of July 1, 2009, for each state and the District of Columbia. We...

  18. 77 FR 4000 - Estimates of the Voting Age Population for 2011

    Science.gov (United States)

    2012-01-26

    ... Office of the Secretary Estimates of the Voting Age Population for 2011 AGENCY: Office of the Secretary, Commerce. ACTION: General Notice Announcing Population Estimates. SUMMARY: This notice announces the voting age population estimates as of July 1, 2011, for each state and the District of Columbia. We...

  19. Strategic Decision-Making Learning from Label Distributions: An Approach for Facial Age Estimation

    OpenAIRE

    Wei Zhao; Han Wang

    2016-01-01

    Nowadays, label distribution learning is among the state-of-the-art methodologies in facial age estimation. It takes the age of each facial image instance as a label distribution with a series of age labels rather than the single chronological age label that is commonly used. However, this methodology is deficient in its simple decision-making criterion: the final predicted age is only selected at the one with maximum description degree. In many cases, different age labels may have very simil...

  20. Statistical Estimation of the Age of the Universe

    DEFF Research Database (Denmark)

    Petersen, Jørgen Holm

    The Hubble constant enters big bang cosmology by quantifying the expansion rate of the universe. It is shown that the standard technique for estimation of Hubble's constant is statistically inconsistent and results in a systematically too low value. An alternative, consistent estimator of Hubble...

  1. Carbon Dating The Web: Estimating the Age of Web Resources

    OpenAIRE

    SalahEldeen, Hany M.; Nelson, Michael L.

    2013-01-01

    In the course of web research it is often necessary to estimate the creation datetime for web resources (in the general case, this value can only be estimated). While it is feasible to manually establish likely datetime values for small numbers of resources, this becomes infeasible if the collection is large. We present "carbon date", a simple web application that estimates the creation date for a URI by polling a number of sources of evidence and returning a machine-readable structure with t...

  2. The problem of low thermoluminescence age estimates in geological dating

    International Nuclear Information System (INIS)

    A systematic underestimate of the geological age by the TL technique has been observed in a variety of CaCO3 samples of Quaternary to Precambrian ages. It is concluded that the TL dating clock in the CaCO3 lattice stops when the alpha palaeodose =alpha (rad a-1)x geological age (a) reaches about 100,000 rad. At this dose the natural thermoluminescence reaches perhaps a dynamic equilibrium level determined solely by the alpha activity of the sample. There are indications that the limiting alpha palaeodose beyond which TL dating is invalid is more or less the same for CaSO4 and silicate samples, and it is convenient to note a limiting value of 3 million for the product of alpha activity (cph from 13.86 cm2) and geological age (a). (author)

  3. Thermoluminescence and new 14C age estimates for late quaternary loesses in southwestern Nebraska

    Science.gov (United States)

    Maat, P.B.; Johnson, W.C.

    1996-01-01

    Loess of late Quaternary age mantles most of Nebraska south of the Platte River Valley. At least five late Quaternary loesses are recognized: from oldest to youngest, one or more undifferentiated pre-lllinoian loesses, the Loveland Loess, the Gilman Canyon Loess, which exhibits a well developed soil and rests unconformably on the Sangamon soil, the Peoria Loess capped by the Brady soil, and the Bignell Loess, which is distributed discontinuously. Previous research shows that the Loveland Loess is Illinoian. the Gilman Canyon Loess and Peoria Loess are Wisconsin, and the Bignell Loess is Holocene. We present here the first thermoluminescence (TL) age estimates and new C ages for these late Quaternary loesses at two key sections in southwestern Nebraska, the Eustis ash pit and the Bignell Hill road cut. TL age estimates from all samples collected from Eustis ash pit and Bignell Hill were internally consistent. TL and C age estimates from these two sections generally agree and support previous age determinations. The TL age estimate on Loveland Loess indicates deposition at 163 ka. TL and radiocarbon age estimates indicate that Oilman Canyon Loess, believed to be deposited during the Farmdale interstade, first began to accumulate at about 40 ka: the lower part of the Gilman Canyon Loess is 36 ka at Eustis and the middle of the unit is 30 ka at Bignell Hill. The lower and upper parts of the Peoria Loess give age estimates of 24 ka and 17 ka, respectively. TL age estimates for deposition of the Bignell Loess are 9 ka near the base, in agreement with radiocarbon age estimates, and 6 ka immediately below the modern soil, substantiating its Holocene age. Comparisons of TL age estimates with ??18O and insolation curves which show loess deposition during interglacial and interstadial as well as glacial periods, indicate that loess deposition on the Great Plains can occur under a variety of climatic conditions.

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

    OpenAIRE

    Skoog Waller, Sara; Eriksson, Mårten; Sörqvist, Patrik

    2015-01-01

    Cognitive hearing science is mainly about the study of how cognitive factors contribute to speech comprehension, but cognitive factors also partake in speech processing to infer non-linguistic information from speech signals, such as the intentions of the talker and the speaker’s age. Here, we report two experiments on age estimation by “naïve” listeners. The aim was to study how speech rate influences estimation of speaker age by comparing the speakers’ natural speech rate with increased or ...

  5. Evaluating the Reliability of Three Different Dental Age Estimation Methods in Visakhapatnam Children

    OpenAIRE

    Patnana, Arun Kumar; Vabbalareddy, Raja Sekhar; V Vanga, Narasimha Rao

    2015-01-01

    ABSTRACT% Dental age is important for treatment planning in the specialities of pedodontics and orthodontics. Although, Demirjian's method was considered standard for dental age estimation, it may not be reliable for all population. Aim: The goal of the study was to evaluate the reliability of Demir-jian's, Haavikko's and Willems method of dental age estimation methods in Visakhapatnam (Andhra Pradesh, India) children. Study design: One hundred and two children of 6 to 14 years old who underw...

  6. The ossification pattern in paediatric occipito-cervical spine: is it possible to estimate real age?

    International Nuclear Information System (INIS)

    Aim: To retrospectively analyse the synchondrosis from the occipital bone to the whole cervical spine and determine the feasibility and validity of age estimation using computed tomography (CT) images. Material and methods: A total of 231 cervical spine or neck CT images of young children (<7 years of age) were examined. Twelve ossification centres were assessed (occiput: n = 2; atlas: n = 2; axis, n = 6; whole sub-axial vertebra: n = 2), and the ossification process was graded as open (O, fully lucent), osseous bridging (B, partially ossified), and fusion (F, totally ossified). After the first analysis was completed, the resulting chronological chart was used to estimate the age of 10 new cases in order to confirm the usefulness of the chart. Results: Infancy was easily estimated using the sub-axial or C2 posterior ossification centres, while the posterior occipital regions provided good estimation of age between 1–2 years. The most difficult period for accurate age estimation was between 2–4 years. However, the C2 anterior (neurocentral ossification) and C1 posterior regions did yield information to help determine the age around 3 years. The anterior occipital region was useful for age estimation between 4–5 years, and the C1-anterior region was potentially useful to help decide among the other parameters. The test for age estimation (TAE) had a very high ICC score (0.973) among the three observers. Conclusion: Segmentalised analysis can enhance the ability to estimate real age, at least by the year. The analysis of the occipital bone made a strong contribution to the usefulness of the chorological chart. An organised chronological chart can provide readily available information for age estimation, and the primary application of the above data (TAE) demonstrated the validity of this approach. -- Highlights: •Subaxial or C2 posterior regions was useful for age estimation between 0–1 year. •Posterior occipital regions provided good estimation of

  7. Spatially explicit estimation of forest age by integrating remotely sensed data and inverse yield modeling techniques

    OpenAIRE

    Frate L; Carranza ML; Garfì V; Febbraro MD; Tonti D; Marchetti M; Ottaviano M.; Santopuoli G; Chirici G

    2016-01-01

    In this work we present an innovative method based on the application of inverse yield models for producing spatially explicit estimations of forest age. Firstly, a raster growing stock volume map was produced using the non-parametric k-Nearest Neighbors estimation method on the basis of IRS LISS-III remotely sensed imagery and field data collected in the framework of a local forest inventory. Secondly, species specific inverted yield equations were applied to estimate forest age as a functio...

  8. Estimation of age structure of fish populations from length-frequency data

    International Nuclear Information System (INIS)

    A probability model is presented to determine the age structure of a fish population from length-frequency data. It is shown that when the age-length key is available, maximum-likelihood estimates of the age structure can be obtained. When the key is not available, approximate estimates of the age structure can be obtained. The model is used for determination of the age structure of populations of channel catfish and white crappie. Practical applications of the model to impact assessment are discussed

  9. New Method of Age Estimation from Maxillary Sutures Closure in a Thai Population.

    Science.gov (United States)

    Sinthubua, A; Theera-Umpon, N; Auephanwiriyakul, S; Ruengdit, S; Das, S; Mahakkanukrauh, P

    2016-01-01

    Age estimation is one of the major components of forensic identification. Cranial suture closure has long been used as indicator for age estimation. Maxillary sutures have been less studied for estimation of age at death because they vary in their timing of closure with age. The purpose of this study was to estimate age by examining 190 Thai skulls with age ranging between 15-93 years from Forensic Osteology Research Center, Faculty of Medicine, and Chiang Mai University. Four parts of maxillary suture (incisive, anterior, transverse, and posterior sutures) were investigated the suture obliteration of each suture by computerizing from photograph. The suture were measured by pixel counting.The prediction model which based on the support vector machine (SVM) for regression or support vector regression (SVR) was utilized for data analysis. The results showed high correlation (R2 = 0.9086) between the predicted age and actual age. Plot between actual age group and predicted age in seven groups also revealed high correlation (R2 = 0.9434). These can be implied that we are able to use this SVR model to predict age at death using maxillary suture information.The interesting issue is to further apply this model in more cases to ensure the generalization of the finding. This study is the first attempt to estimate age at death using a new method based on novel analysis which considers a characteristic of relationship between maxillary suture closures with age that are not in linear form. The present study may contribute as a basis knowledge and method for further study of age estimation in archaeological and forensic anthropological contexts, especially when only skull or base of skull are found. PMID:27212570

  10. Estimating the age of formation of lakes: An example from Lake Tanganyika, East African Rift system

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, A.; Soreghan, M.J. [Univ. of Arizona, Tucson, AZ (United States); Scholz, C.A. [Duke Univ. Marine Lab., Beaufort, NC (United States)

    1993-06-01

    Age estimates for ancient lakes are important for determining their histories and their rates of biotic and tectonic evolution. In the absence of dated core material from the lake`s sedimentary basement, several techniques have been used to generate such age estimates. The most common of these, herein called the reflection seismic-radiocarbon method (RSRM), combines estimates of short-term sediment-accumulation rates derived from radiocarbon-dated cores and depth-to-basement estimates derived from reflection-seismic data at or near the same locality to estimate an age to basement. Age estimates form the RSRM suggest that the structural basins of central Lake Tanganyika began to form between 9 and 12 Ma. Estimates for the northern and southern basins are younger (7 to 8 Ma and 2 to 4 Ma, respectively). The diachroneity of estimates for different segments of the lake is equivocal, and may be due to erosional loss of record in the northern and southern structural basins or to progressive opening of the rift. The RSRM age estimates for Lake Tanganyika are considerably younger than most prior estimates and clarify the extensional history of the western branch of the East African Rift system. 31 refs., 3 figs., 1 tab.

  11. Postnatal growth and age estimation in Scotophilus kuhlii.

    Science.gov (United States)

    Chen, Shiang-Fan; Huang, Shang-Shang; Lu, Dau-Jye; Shen, Tsung-Jen

    2016-01-01

    Adequate postnatal growth is important for young bats to develop skilled sensory and locomotor abilities, which are highly associated with their survival once independent. This study investigated the postnatal growth and development of Scotophilus kuhlii in captivity. An empirical growth curve was established, and the postnatal growth rate was quantified to derive an age-predictive equation. By further controlling the fostering conditions of twins, the differences in the development patterns between pups that received maternal care or were hand-reared were analyzed to determine whether the latter developed in the same manner as their maternally reared counterparts. Our results indicate that both forearm length and body mass increased rapidly and linearly during the first 4 weeks, after which the growth rate gradually decreased to reach a stable level. The first flight occurred at an average age of 39 days with a mean forearm length and body mass of 92.07% and 70.52% of maternal size, respectively. The developmental pattern of hand-reared pups, although similar to that of their maternally reared twin siblings, displayed a slightly faster growth rate in the 4th and 5th weeks. The heavier body mass of hand-reared pups during the pre-fledging period may cause higher wing loading, potentially influencing the flight performance and survival of the bats once independent. PMID:26600428

  12. The utility of near infrared spectroscopy for age estimation of deepwater sharks

    Science.gov (United States)

    Rigby, Cassandra L.; Wedding, Brett B.; Grauf, Steve; Simpfendorfer, Colin A.

    2014-12-01

    Reliable age information is vital for effective fisheries management, yet age determinations are absent for many deepwater sharks as they cannot be aged using traditional methods of growth bands counts. An alternative approach to ageing using near infrared spectroscopy (NIRS) was investigated using dorsal fin spines, vertebrae and fin clips of three species of deepwater sharks. Ages were successfully estimated for the two dogfish, Squalus megalops and Squalus montalbani, and NIRS spectra were correlated with body size in the catshark, Asymbolus pallidus. Correlations between estimated-ages of the dogfish dorsal fin spines and their NIRS spectra were good, with S. megalops R2=0.82 and S. montalbani R2=0.73. NIRS spectra from S. megalops vertebrae and fin clips that have no visible growth bands were correlated with estimated-ages, with R2=0.89 and 0.76, respectively. NIRS has the capacity to non-lethally estimate ages from fin spines and fin clips, and thus could significantly reduce the numbers of sharks that need to be lethally sampled for ageing studies. The detection of ageing materials by NIRS in poorly calcified deepwater shark vertebrae could potentially enable ageing of this group of sharks that are vulnerable to exploitation.

  13. Paleomagnetism and radiochemical age estimates for Late Brunhes polarity episodes

    International Nuclear Information System (INIS)

    Several reversed polarity magnetozones occur within deep-sea sediment core CH57-8 from the Greater Antilles Outer Ridge, within sediment of latest Pleistocene/Late Brunhes age. The uppermost reversed interval spanning 31 data points coincides with the X faunal zone of the Last Interglacial Period. Radiochemical dating of cores CH57-8 and KN25-4 has shown that all the reversed polarity magnetozones are significantly younger than the Brunhes/Matuyama boundary at 0.7 m.y.B.P. A variation of the excess 230Th method was used, in which 210Po and 238U were the actual radionuclides measured. In a third core from the Mid-Atlantic Ridge, the 210Po results were similar to those which others obtained earlier by direct 230Th measurements. (Auth.)

  14. Age Estimation Based on AAM and 2D-DCT Features of Facial Images

    Directory of Open Access Journals (Sweden)

    Asuman Günay

    2015-02-01

    Full Text Available This paper proposes a novel age estimation method - Global and Local feAture based Age estiMation (GLAAM - relying on global and local features of facial images. Global features are obtained with Active Appearance Models (AAM. Local features are extracted with regional 2D-DCT (2- dimensional Discrete Cosine Transform of normalized facial images. GLAAM consists of the following modules: face normalization, global feature extraction with AAM, local feature extraction with 2D-DCT, dimensionality reduction by means of Principal Component Analysis (PCA and age estimation with multiple linear regression. Experiments have shown that GLAAM outperforms many methods previously applied to the FG-NET database.

  15. Is Greulich–Pyle age estimation applicable for determining maturation in male Africans?

    Directory of Open Access Journals (Sweden)

    Alan G. Morri

    2012-09-01

    Full Text Available Skeletal age estimation as a means of assessing development and skeletal maturation in children and adolescents is of great importance for clinical and forensic purposes. The skeletal age of a test population is estimated by comparison with established standards, the most common standards being those in the Radiographic atlas of skeletal development of the hand and wristpublished by Greulich and Pyle in 1959. These standards are based on the assumption that skeletal maturity in male individuals is attained by the chronological age of 19 years. Although they have been widely tested, the applicability of these standards to contemporary populations has yet to be tested on a population of African biological origin living in South Africa. We therefore estimated the skeletal age of 131 male Africans aged between 13 and 21 years, using the Greulich–Pyle method which we applied to pre-existing hand–wrist radiographs. Estimated skeletal age was compared to the known chronological age for each radiograph. Skeletal age was on average approximately 6 months younger than chronological age. The Greulich–Pyle method underestimated skeletal age for approximately 74%of the sample and overestimated skeletal age for 26%of the sample. Skeletal maturity as characterised by complete epiphyseal fusion occurred approximately 2.1 years later than Greulich and Pyle’s estimate of 19 years. Thus skeletal maturation was still in progress in a large proportion of the 20- and 21-year-old individuals in our study. The Greulich–Pyle method showed high precision but low accuracy and was therefore not directly applicable to African male individuals. Formulation of skeletal age estimation standards specific to South African populations is therefore recommended.

  16. Age Estimates of Universe: from Globular Clusters to Cosmological Models and Probes

    CERN Document Server

    Fatima, Hira; Rahman, Syed Faisal Ur

    2016-01-01

    We performed the photometric analysis of M2 and M92 globular clusters in g and r bands of SLOAN photometric system. We transformed these g and r bands into BV bands of Johnson-Cousins photometric system and built the color magnitude diagram (CMD). We estimated the age, and metallicity of both the clusters, by fitting Padova isochrones of different age and metallicities onto the CMD. We studied Einstein and de Sitter model, bench mark model, the cosmological parameters by WMAP and Planck surveys. Finally, we compared estimated age of globular clusters to the ages from the cosmological models and cosmological parameters values of WMAP and Planck surveys.

  17. Artificial Neural Networks and Gene Expression Programing based age estimation using facial features

    Directory of Open Access Journals (Sweden)

    Baddrud Z. Laskar

    2015-10-01

    Full Text Available This work is about estimating human age automatically through analysis of facial images. It has got a lot of real-world applications. Due to prompt advances in the fields of machine vision, facial image processing, and computer graphics, automatic age estimation via faces in computer is one of the dominant topics these days. This is due to widespread real-world applications, in areas of biometrics, security, surveillance, control, forensic art, entertainment, online customer management and support, along with cosmetology. As it is difficult to estimate the exact age, this system is to estimate a certain range of ages. Four sets of classifications have been used to differentiate a person’s data into one of the different age groups. The uniqueness about this study is the usage of two technologies i.e., Artificial Neural Networks (ANN and Gene Expression Programing (GEP to estimate the age and then compare the results. New methodologies like Gene Expression Programing (GEP have been explored here and significant results were found. The dataset has been developed to provide more efficient results by superior preprocessing methods. This proposed approach has been developed, tested and trained using both the methods. A public data set was used to test the system, FG-NET. The quality of the proposed system for age estimation using facial features is shown by broad experiments on the available database of FG-NET.

  18. Dental age estimation of growing children by measurement of open apices: A Malaysian formula

    Directory of Open Access Journals (Sweden)

    Navaneetha Cugati

    2015-01-01

    Full Text Available Background: Age estimation is of prime importance in forensic science and clinical dentistry. Age estimation based on teeth development is one reliable approach. Many radiographic methods are proposed on the Western population for estimating dental age, and a similar assessment was found to be inadequate in Malaysian population. Hence, this study aims at formulating a regression model for dental age estimation in Malaysian children population using Cameriere′s method. Materials and Methods: Orthopantomographs of 421 Malaysian children aged between 5 and 16 years involving all the three ethnic origins were digitalized and analyzed using Cameriere′s method of age estimation. The subjects′ age was modeled as a function of the morphological variables, gender (g, ethnicity, sum of normalized open apices (s, number of tooth with completed root formation (N 0 and the first-order interaction between s and N 0 . Results: The variables that contributed significantly to the fit were included in the regression model, yielding the following formula: Age = 11.368-0.345g + 0.553N o -1.096s - 0.380s.N o , where g is a variable, 1 for males and 2 for females. The equation explained 87.1% of total deviance. Conclusion: The results obtained insist on reframing the original Cameriere′s formula to suit the population of the nation specifically. Further studies are to be conducted to evaluate the applicability of this formula on a larger sample size.

  19. Dental age estimation of growing children by measurement of open apices: A Malaysian formula

    Science.gov (United States)

    Cugati, Navaneetha; Kumaresan, Ramesh; Srinivasan, Balamanikanda; Karthikeyan, Priyadarshini

    2015-01-01

    Background: Age estimation is of prime importance in forensic science and clinical dentistry. Age estimation based on teeth development is one reliable approach. Many radiographic methods are proposed on the Western population for estimating dental age, and a similar assessment was found to be inadequate in Malaysian population. Hence, this study aims at formulating a regression model for dental age estimation in Malaysian children population using Cameriere's method. Materials and Methods: Orthopantomographs of 421 Malaysian children aged between 5 and 16 years involving all the three ethnic origins were digitalized and analyzed using Cameriere's method of age estimation. The subjects’ age was modeled as a function of the morphological variables, gender (g), ethnicity, sum of normalized open apices (s), number of tooth with completed root formation (N0) and the first-order interaction between s and N0. Results: The variables that contributed significantly to the fit were included in the regression model, yielding the following formula: Age = 11.368-0.345g + 0.553No -1.096s - 0.380s.No, where g is a variable, 1 for males and 2 for females. The equation explained 87.1% of total deviance. Conclusion: The results obtained insist on reframing the original Cameriere's formula to suit the population of the nation specifically. Further studies are to be conducted to evaluate the applicability of this formula on a larger sample size. PMID:26816464

  20. Egg flotation estimates nest age for Pacific and Red-throated Loons

    Science.gov (United States)

    Rizzolo, D.J.; Schmutz, J.A.

    2007-01-01

    We used Pacific Loon (Gavia pacifica) and Red-throated Loon (G. stellata) nests with known ages to gauge the efficacy of egg flotation for determining nest age in coastal Alaska. Egg flotation accurately estimated nest age for both species; the mean ?? 1SD difference between known age and age determined with egg flotation was - 0.05 ?? 2.00 d and -0.02 ?? 1.63 d for Pacific and Red-throated Loons, respectively. Day of nest initiation did not influence the relationship between known nest age and nest age estimated with egg flotation, indicating incubation period was not shortened in nests initiated later in the season. Additionally, we found no difference in the ability of egg flotation to estimate nest age between two widely dispersed study sites for Pacific Loons, and only a small difference between two of three widely dispersed study sites for Red-throated Loons. Thus, our described relationships between egg flotation categories and nest age should be broadly applicable for these holarctic species. We conclude that for Pacific and Red-throated Loons, egg flotation is a useful technique for determining nest age in the field to better monitor nest fate, and to quantify nest age effects on nest daily survival rate.

  1. Skeletal age estimation in a contemporary Western Australian population using the Tanner-Whitehouse method.

    Science.gov (United States)

    Maggio, Ariane; Flavel, Ambika; Hart, Rob; Franklin, Daniel

    2016-06-01

    Various age estimation techniques have been utilised in Australia to evaluate the age of individuals who do not have documentation to determine legal majority/culpability. These age estimation techniques rely on the assessment of skeletal development as visualised in radiographs, CT scans, MRI or ultrasound modalities, and subsequent comparison to reference standards. These standards are not always population specific and are thus known to be less accurate when applied outside of the original reference sample, leading to potential ethical implications. Therefore, the present study aims to: (i) explore the variation in developmental trajectories between the established Tanner-Whitehouse (TW) age estimation standards and a Western Australian population; and (ii) develop specific hand-wrist age estimation standards for the latter population. The present study examines digital anterior-posterior hand-wrist radiographs of 360 individuals 0 to 24.9 years of age, equally represented by sex. Each radiograph was assessed using the RUS, Carpal and 20-bone methods of Tanner et al. The standard error of the estimate (SEE) was calculated for each method (range: ♀ SEE ±0.4-11.5 years; ♂ SEE ±0.9-10.1 years). The most accurate method was TW3 RUS for females and the TW2 Carpal system for males. The 50th centile skeletal maturity scores for each year age group were plotted against average chronological age to produce polynomial regression standards with a demonstrated accuracy of (♀ SEE ±0.09-3.46 years; ♂ SEE ±0.02-3.42 years) for females and males, respectively. The standards presented here can be used in future forensic investigations that require age estimation of hand-wrist bones in a Western Australian population, however, they are not appropriate for establishing age of majority (18 years), as skeletal maturity was attained on average earlier than 15 years of age in both sexes for all three systems examined. PMID:27080619

  2. A revised burial dose estimation procedure for optical dating of youngand modern-age sediments

    Science.gov (United States)

    Arnold, L.J.; Roberts, R.G.; Galbraith, R.F.; DeLong, S.B.

    2009-01-01

    The presence of genuinely zero-age or near-zero-age grains in modern-age and very young samples poses a problem for many existing burial dose estimation procedures used in optical (optically stimulated luminescence, OSL) dating. This difficulty currently necessitates consideration of relatively simplistic and statistically inferior age models. In this study, we investigate the potential for using modified versions of the statistical age models of Galbraith et??al. [Galbraith, R.F., Roberts, R.G., Laslett, G.M., Yoshida, H., Olley, J.M., 1999. Optical dating of single and multiple grains of quartz from Jinmium rock shelter, northern Australia: Part I, experimental design and statistical models. Archaeometry 41, 339-364.] to provide reliable equivalent dose (De) estimates for young and modern-age samples that display negative, zero or near-zero De estimates. For this purpose, we have revised the original versions of the central and minimum age models, which are based on log-transformed De values, so that they can be applied to un-logged De estimates and their associated absolute standard errors. The suitability of these 'un-logged' age models is tested using a series of known-age fluvial samples deposited within two arroyo systems from the American Southwest. The un-logged age models provide accurate burial doses and final OSL ages for roughly three-quarters of the total number of samples considered in this study. Sensitivity tests reveal that the un-logged versions of the central and minimum age models are capable of producing accurate burial dose estimates for modern-age and very young (<350??yr) fluvial samples that contain (i) more than 20% of well-bleached grains in their De distributions, or (ii) smaller sub-populations of well-bleached grains for which the De values are known with high precision. Our results indicate that the original (log-transformed) versions of the central and minimum age models are still preferable for most routine dating applications

  3. Radiological age estimation: based on third molar mineralization and eruption in Turkish children and young adults.

    Science.gov (United States)

    Karadayi, Beytullah; Kaya, Ahsen; Kolusayın, Melek Ozlem; Karadayi, Sükriye; Afsin, Hüseyin; Ozaslan, Abdi

    2012-11-01

    Radiographic evaluation of mineralization and eruption stages of third molars using dental panoramic radiographies can be an efficient tool for chronological age estimation in both forensic sciences and legal medicine. The third molar tooth is utilized for dental age estimation about the age span of 15-23 years because it represents the only tooth still in development. The aim of this study is to obtain and analyze data regarding third molar development and eruption in Turkish population for dental age estimation. A total of 744 dental panoramic radiographies of 394 female and 350 male subjects aged between 8 and 22 years were examined. Third molar development was determined according to the Nolla classification system, and eruption was assessed relative to the alveolar bone level. Mandibular and maxillary third molars were generally found at similar stages of development on both sides. Nolla stage 6 (completed crown calcification) was reached at around the age of 15 in both maxillary and mandibular third molars in both sexes. Alveolar emergence was at around the age of 16 in males and around age of 17 in females. Although third molars' eruption shows greater variability than development of third molars, data which were obtained from this study about eruption of these teeth can be supportive to development data for age estimation. PMID:23010906

  4. Validity of demirjian and nolla methods for dental age estimation for Northeastern Turkish children aged 5–16 years old

    Science.gov (United States)

    Nur, Bilge; Kusgoz, Adem; Bayram, Mehmet; Nur, Metin; Kayipmaz, Saadettin; Yildirim, Sina

    2012-01-01

    Objective: To evaluate the applicability of Demirjian and Nolla methods for northeastern Turkish population. Material and Method: A retrospective study was performed on panoramic radiographs of 673 subjects aged 5–15.9 years. The mean dental age (DA) according to the Demirjian and Nolla methods were compared to the mean chronological age (CA). Results: The mean CA of the study sample was 10.37±2.90 and 10.03±2.81 years for females and males, respectively. Using the Demirjian method, the mean estimated DA was 11.26±3.02 years for females and 10.87±2.96 years for males. For Nolla method, the mean estimated DA was 9.80±3.41 and 9.53±3.14 years for females and males, respectively. The mean differences between the CA and DA according to the Demirjian and Nolla methods were 0.86 and -0.54 years for total study sample. Conclusion: Nolla method was found to be a more accurate method for estimating DA in northeastern Turkish population. Key words:Dental age, demirjian method, nolla method, chronological age. PMID:22549686

  5. A method for estimating age of Danish medieval sub-adults based on long bone length

    DEFF Research Database (Denmark)

    Primeau, C.; Lynnerup, Niels; Friis, Laila Saidane;

    2012-01-01

    aging archaeological Danish sub-adults from the medieval period based on diaphyseal lengths. The problem with using data on Danish samples, which have been derived from a different population, is the possibility of skewing age estimates. In this study 58 Danish archaeological sub-adults were examined...... archaeological data. After the cross point there was a maximum difference of three years and four months higher for the archaeological data. This study has shown the importance of using data for age estimation for archaeological material which has been developed specifically for that population. In addition it......The preferred method for aging archaeological sub-adult skeletons is by dental examination. In cases where no dental records are available, age estimation may be performed according to epiphyseal union, skeletal elements or diaphyseal lengths. Currently no data have been produced specifically for...

  6. Comparison of Fundal Height Measurement and Ultrasonography for Estimation of Gestational Age

    OpenAIRE

    M Aflatoonian; M Nasirian; L Koochak-Yazdi; MR Hajiesmaeili; A Tabatabaei; M Mojibian

    2008-01-01

    Introduction: Estimation of gestational age is an essential component of prenatal care. Gestational age is estimated by Last Menopausal Period, fundal height and ultrasonography. Serial measurment of fundal height and comparison with LMP predicts the G.A more accurately. Since nowadays, ultrasonography is used more frequently during pregnancy, patients have to bear more expenses. But we can use serial measurement of fundal height for determination of G.A. This method is cheap, reliable and ea...

  7. In situ acoustic methods to estimate the physical and mechanical aging of oriented strand board

    OpenAIRE

    Bobadilla Maldonado, Ignacio; Robles, Marta; Martínez, Roberto; Iñiguez Gonzalez, Guillermo; Arriaga Martitegui, Francisco

    2011-01-01

    Following the success achieved in previous research projects usin non-destructive methods to estimate the physical and mechanical aging of particle and fibre boards, this paper studies the relationships between aging, physical and mechanical changes, using non-destructive measurements of oriented strand board (OSB). 184 pieces of OSB board from a French source were tested to analyze its actual physical and mechanical properties. The same properties were estimated using acoustic non-destructiv...

  8. Human Age Estimation Method Robust to Camera Sensor and/or Face Movement.

    Science.gov (United States)

    Nguyen, Dat Tien; Cho, So Ra; Pham, Tuyen Danh; Park, Kang Ryoung

    2015-01-01

    Human age can be employed in many useful real-life applications, such as customer service systems, automatic vending machines, entertainment, etc. In order to obtain age information, image-based age estimation systems have been developed using information from the human face. However, limitations exist for current age estimation systems because of the various factors of camera motion and optical blurring, facial expressions, gender, etc. Motion blurring can usually be presented on face images by the movement of the camera sensor and/or the movement of the face during image acquisition. Therefore, the facial feature in captured images can be transformed according to the amount of motion, which causes performance degradation of age estimation systems. In this paper, the problem caused by motion blurring is addressed and its solution is proposed in order to make age estimation systems robust to the effects of motion blurring. Experiment results show that our method is more efficient for enhancing age estimation performance compared with systems that do not employ our method. PMID:26334282

  9. Human Age Estimation Method Robust to Camera Sensor and/or Face Movement

    Directory of Open Access Journals (Sweden)

    Dat Tien Nguyen

    2015-08-01

    Full Text Available Human age can be employed in many useful real-life applications, such as customer service systems, automatic vending machines, entertainment, etc. In order to obtain age information, image-based age estimation systems have been developed using information from the human face. However, limitations exist for current age estimation systems because of the various factors of camera motion and optical blurring, facial expressions, gender, etc. Motion blurring can usually be presented on face images by the movement of the camera sensor and/or the movement of the face during image acquisition. Therefore, the facial feature in captured images can be transformed according to the amount of motion, which causes performance degradation of age estimation systems. In this paper, the problem caused by motion blurring is addressed and its solution is proposed in order to make age estimation systems robust to the effects of motion blurring. Experiment results show that our method is more efficient for enhancing age estimation performance compared with systems that do not employ our method.

  10. Estimation of embrittlement during aging of AISI 316 stainless steel TIG welds

    Indian Academy of Sciences (India)

    J Nayak; K R Udupa; K R Hebbar; H V S Nayak

    2004-12-01

    Weldments of AISI grade 316 stainless steel, having a ferrite content of 4–6% and a variety of nitrogen concentrations were prepared using a modified element implant technique. Charpy impact specimens prepared from these weldments were subjected to a variety of aging treatments. Impact toughness decreases with aging time at all aging temperatures. Nitrogen is found to be beneficial to toughness. An empirical relation connecting the aging temperature, aging time and nitrogen content with toughness has been developed which can be used to estimate the time for embrittlement.

  11. Listener estimations of talker age: A meta-analysis of the literature.

    Science.gov (United States)

    Hunter, Eric J; Ferguson, Sarah Hargus; Newman, Catherine Anne

    2016-10-01

    Numerous studies, most of them cross-sectional studies using one sample per talker, have demonstrated that listeners make relatively accurate age judgments from hearing talkers' voices. The current study analyzed the results of several such direct age estimation studies to characterize better the perception of talker age over a larger number of individuals. A review of the direct age estimation literature was performed. Data sets from seven papers were reconstituted, and an analysis of the combined data (meta-analysis) including 530 data points was conducted. The reconstituted and combined data included talkers aged 10-90. Listeners appeared to overestimate age when talkers were younger and to underestimate it when talkers were older. PMID:26079468

  12. Estimation of equipment lifetime with respect of ageing using Bayesian approach

    International Nuclear Information System (INIS)

    The main purpose of the study is to determine the moment at which the ageing process starts and to estimate the degradation level of the system using plant specific data. The ageing problem is very important in safety operation of nuclear power plant, for example, in Ignalina NPP (Lithuania). (author)

  13. Normative perceptual estimates for 91 healthy subjects age 60-75

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Nielsen, Simon

    2014-01-01

    of Visual Attention (TVA). In addition to the estimates themselves, we present correlational data on between the estimates and self-reported demographic data and activities of daily living. The correlates suggests that age, video gaming activity and employment status may significantly impact the encoding...

  14. Estimation of age based on tooth cementum annulations using three different microscopic methods

    OpenAIRE

    Siddharth Pundir; Susmita Saxena; Pooja Aggrawal

    2009-01-01

    Background: The hard tissues of human dentition are able to resist decay and degradation long after other tissues are lost. This resistance to decay has made teeth useful for calculation of age at death of an individual. Recent research indicates that tooth cementum annulations (TCA) may be used more reliably than other morphological or histological traits of the adult skeleton for estimation of age. Objectives: The purpose of this study was to examine the correlation between age and the num...

  15. Age and growth estimation of bigeye tuna, Thunnus obesus (Teleostei: Scombridae) in the southwestern Atlantic

    OpenAIRE

    Paulo Duarte-Neto; Fábio M. Higa; Rosangela P. Lessa

    2012-01-01

    The purpose of the current study was to supply the first information on age and growth for Thunnus obesus caught in the equatorial south-western Atlantic using dorsal spines, an approach that has been successfully employed for ageing tuna species. The study was conducted using a multi-model inference based on information theory for back-calculated and observed length-at-age data. Uncertainty associated with the parameter estimation was verified and results were compared to other accounts on t...

  16. Exfoliative cytology: A possible tool in age estimation in forensic odontology

    OpenAIRE

    Devi Charan Shetty; Vijay Wadhwan; Kaveri Surya Khanna; Anshi Jain; Amit Gupta

    2015-01-01

    Introduction: Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster because the age at death, birth date, and year of death as well as gender can guide investigators to the correct identity among a large number of possible matches. Objective: The study was undertaken with an aim to estimate the age of an individual from their buccal smears by comparing the average cell size using image analysis morphometric software. Materials and Me...

  17. Age dependent sampling biases in tsetse flies (Glossina): Problems associated with estimating mortality from sample age distributions

    International Nuclear Information System (INIS)

    For a closed (island) population of G. morsitans morsitans Westwood, the probability per week of capturing females on ox fly rounds was about 0.3 in the first week of life, less than 0.2 for 27 to 35-d-old flies and greater than 0.4 for flies more than 80 d old. For open populations, the relative changes in capture probability were measured from the ovarian age distributions of trap and ox fly round samples. They were used (with island data) to show that the age dependent sampling bias of traps for female G. m. morsitans increased more than sixfold over the first 80 d of life. The age dependent bias for G. pallidipes Austen taken from odour baited traps is probably at least as serious as for G. m. morsitans. Estimates of daily mortality from the mark-recapture studies were always (up to 20 times) higher than estimates from ovarian age samples taken at the same times. The mortalities recalculated from samples adjusted for sampling biases were closer to, but still lower than, the mark-recapture estimates. Odour baited targets are successful in controlling tsetse populations, despite the relatively low probability of treating young females. If sterilants instead of insecticides were used on the targets, young females could be treated indirectly via treated males, which transfer the sterilant to virgin females during copulation. (author). 15 refs, 2 figs

  18. Human age estimation from blood using mRNA, DNA methylation, DNA rearrangement, and telomere length.

    Science.gov (United States)

    Zubakov, Dmitry; Liu, Fan; Kokmeijer, Iris; Choi, Ying; van Meurs, Joyce B J; van IJcken, Wilfred F J; Uitterlinden, André G; Hofman, Albert; Broer, Linda; van Duijn, Cornelia M; Lewin, Jörn; Kayser, Manfred

    2016-09-01

    Establishing the age of unknown persons, or persons with unknown age, can provide important leads in police investigations, disaster victim identification, fraud cases, and in other legal affairs. Previous methods mostly relied on morphological features available from teeth or skeletal parts. The development of molecular methods for age estimation allowing to use human specimens that possess no morphological age information, such as bloodstains, is extremely valuable as this type of samples is commonly found at crime scenes. Recently, we introduced a DNA-based approach for human age estimation from blood based on the quantification of T-cell specific DNA rearrangements (sjTRECs), which achieves accurate assignment of blood DNA samples to one of four 20-year-interval age categories. Aiming at improving the accuracy of molecular age estimation from blood, we investigated different types of biomarkers. We started out by systematic genome-wide surveys for new age-informative mRNA and DNA methylation markers in blood from the same young and old individuals using microarray technologies. The obtained candidate markers were validated in independent samples covering a wide age range using alternative technologies together with previously proposed DNA methylation, sjTREC, and telomere length markers. Cross-validated multiple regression analysis was applied for estimating and validating the age predictive power of various sets of biomarkers within and across different marker types. We found that DNA methylation markers outperformed mRNA, sjTREC, and telomere length in age predictive power. The best performing model included 8 DNA methylation markers derived from 3 CpG islands reaching a high level of accuracy (cross-validated R(2)=0.88, SE±6.97 years, mean absolute deviation 5.07 years). However, our data also suggest that mRNA markers can provide independent age information: a model using a combined set of 5 DNA methylation markers and one mRNA marker could provide

  19. A Novel Objective Method of Estimating the Age of Mandibles from African Elephants (Loxodonta africana Africana.

    Directory of Open Access Journals (Sweden)

    Fiona J Stansfield

    Full Text Available The importance of assigning an accurate estimate of age and sex to elephant carcasses found in the wild has increased in recent years with the escalation in levels of poaching throughout Africa. Irregularities identified in current ageing techniques prompted the development of a new method to describe molar progression throughout life. Elephant mandibles (n = 323 were studied and a point near the distal dental alveolus was identified as being most useful in ranking each jaw according to molar progression. These 'Age Reference Lines' were then associated with an age scale based on previous studies and Zimbabwean mandibles of known age. The new ranking produced a single age scale that proved useful for both male and female mandibles up to the maximum lifespan age of 70-75 years. Methods to aid in molar identification and the sexing of found jaws were also identified.

  20. A Novel Objective Method of Estimating the Age of Mandibles from African Elephants (Loxodonta africana Africana).

    Science.gov (United States)

    Stansfield, Fiona J

    2015-01-01

    The importance of assigning an accurate estimate of age and sex to elephant carcasses found in the wild has increased in recent years with the escalation in levels of poaching throughout Africa. Irregularities identified in current ageing techniques prompted the development of a new method to describe molar progression throughout life. Elephant mandibles (n = 323) were studied and a point near the distal dental alveolus was identified as being most useful in ranking each jaw according to molar progression. These 'Age Reference Lines' were then associated with an age scale based on previous studies and Zimbabwean mandibles of known age. The new ranking produced a single age scale that proved useful for both male and female mandibles up to the maximum lifespan age of 70-75 years. Methods to aid in molar identification and the sexing of found jaws were also identified. PMID:25970428

  1. Implications of age and conditional survival estimates for patients with melanoma

    Science.gov (United States)

    Banerjee, Mousumi; Lao, Christopher D.; Wancata, Lauren M.; Muenz, Daniel G.; Haymart, Megan R.; Wong, Sandra L.

    2016-01-01

    Objective Overall cancer incidence is decreasing while melanoma cases increase. Conditional survival estimates offer a more accurate prognosis for patients as they survive past diagnosis. It is unknown the effect age and stage has on a melanoma patient’s conditional survival estimate. Methods Surveillance, Epidemiology, End Results (SEER) data was utilized, identifying new diagnosis cutaneous melanoma patients (N=95,041), from 1998–2005, with up to 12 year follow up. Estimates of disease-specific survival by stage and age were determined by Cox regression and transformed to estimate conditional five-year survival. Results Localized melanoma patients have an excellent five-year survival at diagnosis and subsequent years. For patients with localized and regional disease, an age effect is present for disease-specific mortality when comparing older patients (70–79 years) to younger patients (hazard ratio (HR) for mortality 3.79 (95% confidence interval (CI) 3.01–4.84) and HR 2.36 (95% CI 1.93–2.91), respectively. No age effect difference is observed in disease-specific survival for advanced disease: HR 1.14 (95% CI 0.87–1.53). Over time conditional survival estimates improve for older patients with localized and regional disease. This improvement is not seen in distant disease nor is the age gradient. Conclusions Disease-specific mortality and conditional survival for patients with localized and regional melanoma is initially impacted by older age with effects dissipating over time. Age does not affect survival in patients with advanced disease. Understanding the conditional five-year disease-specific survival of melanoma based on age and stage can help patients and physicians, informing decision making about treatment and surveillance. PMID:26479218

  2. Implications of age and conditional survival estimates for patients with melanoma.

    Science.gov (United States)

    Banerjee, Mousumi; Lao, Christopher D; Wancata, Lauren M; Muenz, Daniel G; Haymart, Megan R; Wong, Sandra L

    2016-02-01

    Overall cancer incidence is decreasing, whereas melanoma cases are increasing. Conditional survival estimates offer a more accurate prognosis for patients the farther they are from time of diagnosis. The effect of age and stage on a melanoma patient's conditional survival estimate is unknown. Surveillance, Epidemiology, and End Results data were utilized to identify newly diagnosed cutaneous melanoma patients (N=95 041), from 1998 to 2005, with up to 12 years of follow-up. Estimates of disease-specific survival by stage and age were determined by Cox regression analysis and transformed to estimated conditional 5-year survival. Localized melanoma patients have an excellent 5-year survival at diagnosis and over subsequent years. For patients with localized and regional disease, an age effect is present for disease-specific mortality when comparing older patients (70-79 years) with younger patients (hazard ratio (HR) for mortality 3.79 [95% confidence interval (CI) 3.01-4.84] and HR 2.36 (95% CI 1.93-2.91), respectively. No age effect difference is observed in disease-specific survival for advanced disease: HR 1.14 (95% CI 0.87-1.53). Over time, conditional survival estimates improve for older patients with localized and regional disease. This improvement is not seen in distant disease, neither is the age gradient. Disease-specific mortality and conditional survival for patients with localized and regional melanomas are initially impacted by older age, with effects dissipating over time. Age does not affect survival in patients with advanced disease. Understanding the conditional 5-year disease-specific survival of melanoma based on age and stage can help patients and physicians, informing decision-making about treatment and surveillance. PMID:26479218

  3. A comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars

    CERN Document Server

    Maxted, P F L; Southworth, J

    2015-01-01

    Previous studies suggest that tidal interactions may be responsible for discrepancies between the ages of exoplanet host stars estimated using stellar models (isochronal ages) and age estimates based on the stars' rotation periods (gyrochronological ages). We have compiled a sample of 28 transiting exoplanet host stars with measured rotation periods. We use a Bayesian Markov chain Monte Carlo method to determine the joint posterior distribution for the mass and age of each star in the sample, and extend this method to include a calculation of the posterior distribution of the gyrochronological age. The gyrochronological age ($\\tau_{\\rm gyro}$) is significantly less than the isochronal age for about half of the stars in our sample. Tidal interactions between the star and planet are a reasonable explanation for this discrepancy in some cases, but not all. The distribution of $\\tau_{\\rm gyro}$ values is evenly spread from very young ages up to a maximum value of a few Gyr. There is no clear correlation between $...

  4. Estimation of Heterogeneity in Diagnostic Parameters of Age-related Diseases.

    Science.gov (United States)

    Blokh, David; Stambler, Ilia

    2014-08-01

    The heterogeneity of parameters is a ubiquitous biological phenomenon, with critical implications for biological systems functioning in normal and diseased states. We developed a method to estimate the level of objects set heterogeneity with reference to particular parameters and applied it to type II diabetes and heart disease, as examples of age-related systemic dysfunctions. The Friedman test was used to establish the existence of heterogeneity. The Newman-Keuls multiple comparison method was used to determine clusters. The normalized Shannon entropy was used to provide the quantitative evaluation of heterogeneity. There was obtained an estimate for the heterogeneity of the diagnostic parameters in healthy subjects, as well as in heart disease and type II diabetes patients, which was strongly related to their age. With aging, as with the diseases, the level of heterogeneity (entropy) was reduced, indicating a formal analogy between these phenomena. The similarity of the patterns in aging and disease suggested a kind of "early aging" of the diseased subjects, or alternatively a "disease-like" aging process, with reference to these particular parameters. The proposed method and its validation on the chronic age-related disease samples may support a way toward a formal mathematical relation between aging and chronic diseases and a formal definition of aging and disease, as determined by particular heterogeneity (entropy) changes. PMID:25110613

  5. Preliminary age, growth and maturity estimates of spotted ratfish (Hydrolagus colliei) in British Columbia

    Science.gov (United States)

    King, J. R.; McPhie, R. P.

    2015-05-01

    The spotted ratfish (Hydrolagus colliei) is a chimaeroid ranging from southeast Alaska to Baja California and found at depths of up to 1029 m. Despite being widespread and ubiquitous, few biological parameter estimates exist for spotted ratfish due to a lack of suitable ageing structures to estimate age and growth. We present preliminary results of age, growth and maturity estimates based on a new method in which tritor ridges are counted on the vomerine tooth plate. We also provide a method for estimating the number of worn tritor ridges based on tooth plate diameter measurements for the spotted ratfish. The tritor ridges are distinct bumps that are easy to identify and precision estimates between readers suggests that this method is transferable. Tritor ridges are a potential structure for estimating age in H. colliei and we provide recommendations for future research to improve the method. We sampled 269 spotted ratfish captured in trawl surveys off the coast British Columbia ranging in size from 74 to 495 mm in precaudal length (PCL). The estimated ages ranged from 2 to 16 years for males and from 2 to 21 years for females. The von Bertalanffy, von Bertalanffy with known size at birth, Gompertz and logistic growth models were fitted to the data. Based on Akaike information criterion corrected for sample size and number of parameters estimated, the logistic growth curve was selected as most suitable. The logistic growth model yielded the following parameter estimates: Linf=407.22 mm (PCL), k=0.23 year-1, t0=-7.06 years for males; L∞=494.52 mm (PCL), k=0.26 year-1, t0=-8.35 years for females. Estimated ages at 50% maturity were 12 and 14 years for males and females, respectively. Correspondingly, the size at 50% maturity estimates was smaller for males (302 mm, PCL) than females (393 mm, PCL). Both estimates are larger than those made for spotted ratfish off of California indicating regional differences in life history traits for this species. Our preliminary

  6. Estimation of age based on tooth cementum annulations using three different microscopic methods

    Directory of Open Access Journals (Sweden)

    Siddharth Pundir

    2009-01-01

    Full Text Available Background: The hard tissues of human dentition are able to resist decay and degradation long after other tissues are lost. This resistance to decay has made teeth useful for calculation of age at death of an individual. Recent research indicates that tooth cementum annulations (TCA may be used more reliably than other morphological or histological traits of the adult skeleton for estimation of age. Objectives: The purpose of this study was to examine the correlation between age and the number of incremental lines in human dental cementum and to ascertain which, among three different forms of microscopy (light, polarized, phase-contrast was the most reliable method of studying cementum. Materials and Methods: The study sample consisted of 40 teeth that had been extracted from patients ranging in age from 20−70 years. Longitudinal ground sections of each tooth were prepared and examined under light microscopy, polarized microscopy, and phase-contrast microscopy. The images were magnified on a computer and the cemental lines were counted with the help of Image Analysis Pro 6.0 software. Only the dark lines were counted. Results: There was a strong positive correlation between the estimated age and calculated age when phase-contrast microscopy was used; the correlation was less for light and polarized microscopy. Our results suggest that there is no significant influence of sex, age, periodontal disease, or tooth type on age estimation by the TCA method. This suggests that the accuracy and repeatability of the method is not dependent on tooth type or location and that this method can be applied to the general population regardless of systemic or periodontal health. Conclusion: With this study we conclude that among the methods of counting incremental lines by various types of microscopy phase-contrast microscopy improves the accuracy of age estimation and may serve as a valuable aid in forensic identification.

  7. Age estimation in Indian children and adolescents in the NCR region of Haryana: A comparative study

    Science.gov (United States)

    Gupta, Swati; Mehendiratta, Monica; Rehani, Shweta; Kumra, Madhumani; Nagpal, Ruchi; Gupta, Ramakant

    2015-01-01

    Introduction: Age estimation is a preliminary step in the identification of an individual. It is a crucial and often most critical step for forensic experts. The assessment has been standardized utilizing common dental diagnostic x-rays, but most such age-estimating systems are European population-based and their applicability has not been determined in the context of the Indian population. Aims and Objectives: To assess the applicability and to compare the methods of dental age estimation by Demirjian's method and the same method as modified by Willems (i.e. the Willems method) in Indian children of the National Capital Region (NCR). Also, to find a correlation among skeletal maturity using the Cervical vertebrae maturation index (CVMI), dental maturity, and chronological age in the same population. Materials and Methods: This cross-sectional study was conducted using dental radiographs of 70 orthodontic patients (37 males, 33 females) in the age range 9-16 years selected by simple random sampling. pantomogram were used to estimate dental age by Demirjian's method and the Willems method using their scoring tables. Lateral cephalograms were used to estimate skeletal maturity using CVMI. The latter was compared with Demirjian's stage for mandibular left second molar. Results: Overestimation of age among males by 0.856 years and 0.496 years was found by Demirjian's and the Willems methods, respectively. Among females, both the methods underestimated the age by 0.31 years and 0.45 years, respectively. Demirjian's stage G corresponded to CVMI stage 3 in males and stage 2 in females. Conclusion: In our study, the Willems method has proved to be more accurate for age estimation among Indian males, and Demirjian's method for Indian females. A statistically significant association appeared between Demirjian's stages and CVMI among both males and females. Our study recommends the derivation of a regression formula by studying a larger section of the Indian population

  8. Age estimation using pulp/tooth area ratio: A digital image analysis

    Directory of Open Access Journals (Sweden)

    Sasidhar Singaraju

    2009-01-01

    Full Text Available Age is one of the essential factors in establishing the identity of the person. Estimation of the human age is a procedure adopted by anthropologists, archeologists, and forensic scientists. Inspection of radiographs and subsequent comparison with radiographic images, in charts yield ′maturity scores′ that help us to assess the age of an individual. Alternative approaches based on digitalization of panoramic radiographs and their computerized storage have recently become available that exploit image analysis to obtain nondestructive metric measurements of both pulp chambers and teeth, which can be used to assess the age of an individual. The purpose of the present study was to present a method for assessing the chronological age based on the relationship between age and measurement of the pulp/tooth area ratio on single-rooted teeth, using orthopantomographs and a computer-aided drafting program AutoCAD 2000.

  9. Infant bone age estimation based on fibular shaft length: model development and clinical validation

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Andy; Stamoulis, Catherine; Bixby, Sarah D.; Breen, Micheal A.; Connolly, Susan A.; Kleinman, Paul K. [Boston Children' s Hospital, Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2016-03-15

    Bone age in infants (<1 year old) is generally estimated using hand/wrist or knee radiographs, or by counting ossification centers. The accuracy and reproducibility of these techniques are largely unknown. To develop and validate an infant bone age estimation technique using fibular shaft length and compare it to conventional methods. We retrospectively reviewed negative skeletal surveys of 247 term-born low-risk-of-abuse infants (no persistent child protection team concerns) from July 2005 to February 2013, and randomized them into two datasets: (1) model development (n = 123) and (2) model testing (n = 124). Three pediatric radiologists measured all fibular shaft lengths. An ordinary linear regression model was fitted to dataset 1, and the model was evaluated using dataset 2. Readers also estimated infant bone ages in dataset 2 using (1) the hemiskeleton method of Sontag, (2) the hemiskeleton method of Elgenmark, (3) the hand/wrist atlas of Greulich and Pyle, and (4) the knee atlas of Pyle and Hoerr. For validation, we selected lower-extremity radiographs of 114 normal infants with no suspicion of abuse. Readers measured the fibulas and also estimated bone ages using the knee atlas. Bone age estimates from the proposed method were compared to the other methods. The proposed method outperformed all other methods in accuracy and reproducibility. Its accuracy was similar for the testing and validating datasets, with root-mean-square error of 36 days and 37 days; mean absolute error of 28 days and 31 days; and error variability of 22 days and 20 days, respectively. This study provides strong support for an infant bone age estimation technique based on fibular shaft length as a more accurate alternative to conventional methods. (orig.)

  10. Infant bone age estimation based on fibular shaft length: model development and clinical validation

    International Nuclear Information System (INIS)

    Bone age in infants (<1 year old) is generally estimated using hand/wrist or knee radiographs, or by counting ossification centers. The accuracy and reproducibility of these techniques are largely unknown. To develop and validate an infant bone age estimation technique using fibular shaft length and compare it to conventional methods. We retrospectively reviewed negative skeletal surveys of 247 term-born low-risk-of-abuse infants (no persistent child protection team concerns) from July 2005 to February 2013, and randomized them into two datasets: (1) model development (n = 123) and (2) model testing (n = 124). Three pediatric radiologists measured all fibular shaft lengths. An ordinary linear regression model was fitted to dataset 1, and the model was evaluated using dataset 2. Readers also estimated infant bone ages in dataset 2 using (1) the hemiskeleton method of Sontag, (2) the hemiskeleton method of Elgenmark, (3) the hand/wrist atlas of Greulich and Pyle, and (4) the knee atlas of Pyle and Hoerr. For validation, we selected lower-extremity radiographs of 114 normal infants with no suspicion of abuse. Readers measured the fibulas and also estimated bone ages using the knee atlas. Bone age estimates from the proposed method were compared to the other methods. The proposed method outperformed all other methods in accuracy and reproducibility. Its accuracy was similar for the testing and validating datasets, with root-mean-square error of 36 days and 37 days; mean absolute error of 28 days and 31 days; and error variability of 22 days and 20 days, respectively. This study provides strong support for an infant bone age estimation technique based on fibular shaft length as a more accurate alternative to conventional methods. (orig.)

  11. Using a near-infrared spectrometer to estimate the age of anopheles mosquitoes exposed to pyrethroids.

    Directory of Open Access Journals (Sweden)

    Maggy T Sikulu

    Full Text Available We report on the accuracy of using near-infrared spectroscopy (NIRS to predict the age of Anopheles mosquitoes reared from wild larvae and a mixed age-wild adult population collected from pit traps after exposure to pyrethroids. The mosquitoes reared from wild larvae were estimated as <7 or ≥7 d old with an overall accuracy of 79%. The age categories of Anopheles mosquitoes that were not exposed to the insecticide papers were predicted with 78% accuracy whereas the age categories of resistant, susceptible and mosquitoes exposed to control papers were predicted with 82%, 78% and 79% accuracy, respectively. The ages of 85% of the wild-collected mixed-age Anopheles were predicted by NIRS as ≤8 d for both susceptible and resistant groups. The age structure of wild-collected mosquitoes was not significantly different for the pyrethroid-susceptible and pyrethroid-resistant mosquitoes (P = 0.210. Based on these findings, NIRS chronological age estimation technique for Anopheles mosquitoes may be independent of insecticide exposure and the environmental conditions to which the mosquitoes are exposed.

  12. Obtaining appropriate interval estimates for age when multiple indicators are used

    DEFF Research Database (Denmark)

    Fieuws, Steffen; Willems, Guy; Larsen, Sara Tangmose;

    2016-01-01

    confidence interval without the need to model the multivariate correlation structure between the indicators. The aim of the present paper is to bring under attention this pragmatic approach and to evaluate its performance in a practical setting. This is all the more needed since recent publications ignore...... the need for interval estimation. To illustrate and evaluate the method, Köhler et al. (1995) third molar scores are used to estimate the age in a dataset of 3200 male subjects in the juvenile age range....

  13. Age estimation based on pelvic ossification using regression models from conventional radiography.

    Science.gov (United States)

    Zhang, Kui; Dong, Xiao-Ai; Fan, Fei; Deng, Zhen-Hua

    2016-07-01

    To establish regression models for age estimation from the combination of the ossification of iliac crest and ischial tuberosity. One thousand three hundred and seventy-nine conventional pelvic radiographs at the West China Hospital of Sichuan University between January 2010 and June 2012 were evaluated retrospectively. The receiver operating characteristic analysis was performed to measure the value of estimation of 18 years of age with the classification scheme for the iliac crest and ischial tuberosity. Regression analysis was performed, and formulas for calculating approximate chronological age according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity were developed. The areas under the receiver operating characteristic (ROC) curves were above 0.9 (p systems, and the cubic regression model was found to have the highest R-square value (R (2) = 0.744 for female and R (2) = 0.753 for male). The present classification scheme for apophyseal iliac crest ossification and the ischial tuberosity may be used for age estimation. And the present established cubic regression model according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity can be used for age estimation. PMID:27169673

  14. A Novel Objective Method of Estimating the Age of Mandibles from African Elephants (Loxodonta africana Africana)

    OpenAIRE

    Stansfield, Fiona J.

    2015-01-01

    The importance of assigning an accurate estimate of age and sex to elephant carcasses found in the wild has increased in recent years with the escalation in levels of poaching throughout Africa. Irregularities identified in current ageing techniques prompted the development of a new method to describe molar progression throughout life. Elephant mandibles (n = 323) were studied and a point near the distal dental alveolus was identified as being most useful in ranking each jaw according to mola...

  15. Estimating age of spotted and spinner dolphins (Stenella attenuata and Stenella longirostris) from teeth

    OpenAIRE

    Myrck, Jr., Albert C.; Hohn, Aleta A.; Sloan, Priscilla A.; Kimura, Makoto; Stanley, Drew D.

    1983-01-01

    This paper is an account of preparation and examination techniques and criteria used to estimate age in decalcified and stained tooth thin sections from spinner and spotted dolphins. A dentinal growth layer group (GLG), composed of two thin light and two thicker dark-stained layers, is deposited annually. The GLG component layers are variably visible, but the "ideal" pattern and successive thinning of dentinal GLGs are used as a guide to determine GLG limits. Age-specific thicknesses of de...

  16. Estimated inventory of plutonium and uranium radionuclides for vegetation in aged fallout areas

    International Nuclear Information System (INIS)

    Data are presented pertinent to the contamination of vegetation by plutonium and other radionuclides in aged fallout areas on the Nevada Test Site (NTS) and the Tonopah Test Range (TTR). The standing biomass of vegetation estimated by nondestructive dimensional methods varied from about 200 to 600 g/m2 for the different fallout areas. Estimated inventories of 238Pu, 239Pu, 240Pu, and 235U in plants and their biological effects are discussed

  17. Age estimation by 3D CT-scans of the Borremose Woman, a Danish bog body

    DEFF Research Database (Denmark)

    Villa, Chiara; Møller Rasmussen, Maria; Lynnerup, Niels

    2011-01-01

    Non-invasive estimation of age at death has been carried out by using 3D CT scanning of a bog body discovered in 1948 in a peat bog in Borremose (Denmark). The bog body has been dated to the 8th century BC, in the last part of the Bronze Age. The skeletal structures useful for age estimation have...... been visualized from CT-scans using the Mimics software from Materialise. Extensive manual editing was necessary, as is common with bog bodies, since the bones were severely degraded and the ordinary range of Hounsfield Units (HU), used for clinical work, is not suitable. Only the cranium, the left...... morphology of the ilium (Buckberry & Chamberlain 2002). These three methods resulted in age spans of 27 to 51, 20 to 32 and 25 to 73 years, respectively, as age at death. A recent method specifically adapted for 2D and 3D images (Dedouit et al. 2008) was also applied resulting in an estimated age at death...

  18. Age-at-maturity estimates for Atlantic coast female striped bass

    Science.gov (United States)

    Berlinsky, David L.; Fabrizio, Mary C.; O'Brien, John F.; Specker, Jennifer L.

    1995-01-01

    This study was undertaken to estimate the percentage of mature female striped bass Morone saxatilis present in each age-class during annual coastal feeding migration. Migratory striped bass (N = 302) were sampled in coastal Rhode Island waters during spring (May-June) and fall (September-November) from 1985 to 1987. Stocks were identified by analysis of morphometric characters and isoelectric focusing of eye-lens proteins. Histological sections of ovarian tissue were used to categorize maturity state. Fish were considered mature if a class of oocytes measuring at least 150 μm and containing cytoplasmic inclusions was found in the ovarian sections. All females whose age at next potential spawning was 7 and older were mature. Our empirical observations indicated that 12% of fish in age-class 4, 34% of fish in age-class 5, and 77% of fish in age-class 6 were mature. The estimate of the proportion of mature fish in age-class 5 differs significantly from that of Merriman (1941), who also examined coastal migrants. No significant differences were found in maturity estimates of fish from stocks of different origin.

  19. A method for estimating gestational age of fetal remains based on long bone lengths.

    Science.gov (United States)

    Carneiro, Cristiana; Curate, Francisco; Cunha, Eugénia

    2016-09-01

    The estimation of gestational age (GA) in fetal human remains is important in forensic settings, particularly to assess fetal viability, in addition to often being the only biological profile parameter that can be assessed with some accuracy for non-adults. The length of long bone diaphysis is one of the most frequently used methods for fetal age estimation. The main objective of this study was to present a simple and objective method for estimating GA based on the measurements of the diaphysis of the femur, tibia, fibula, humerus, ulna, and radius. Conventional least squares regression equations (classical and inverse calibration approaches) and quick reference tables were generated. A supplementary objective was to compare the performance of the new formulae against previously published models. The sample comprised 257 fetuses (136 females and 121 males) with known GA (between 12 and 40 weeks) and was selected based on clinical and pathological information. All measurements were performed on radiographic images acquired in anonymous clinical autopsy records from spontaneous and therapeutic abortions in two Portuguese hospitals. The proposed technique is straightforward and reproducible. The models for the GA estimation are exceedingly accurate and unbiased. Comparisons between inverse and classical calibration show that both perform exceptionally well, with high accuracy and low bias. Also, the newly developed equations generally outperform earlier methods of GA estimation in forensic contexts. Quick reference tables for each long bone are now available. The obtained models for the estimation of gestational age are of great applicability in forensic contexts. PMID:27251047

  20. Age estimation in 25-45 yrs. old females by physical and radiological methods

    Directory of Open Access Journals (Sweden)

    Vikrant Kasat

    2010-01-01

    Full Text Available Aim:The purpose of this study was to estimate the age in living females in the later years (25 to 45 years from general physical features and radiographic changes in the sternum and the mandible. Materials and Methods:A cross-sectional study was conducted on 64 females (32 subjects in each study and control group. All the subjects were physically examined for graying of scalp, body, pubic hair, and for wrinkling of skin of the forehead, temporal region, and below the eyes. A right lateral view of the chest was taken to determine fusion of the components of the sternum. Combined Hair Score, Combined Skin Score, and Combined Bone Fusion Score were calculated. An orthopantomogram of each patient was traced for lower jaw, mandibular canal and teeth, and D 1 , D 2 , A values were calculated. SPSS Software Version 10.1 was used for the execution of the regression command on the 32 cases of the control group, whose ages were known. Results:Combined skin score, mandible right D 2 , mandible right angle, and mandible left angle turned out significant in the prediction of age. Using the regression equation obtained, the age of the 32 subjects in the study group was estimated. In 9.3% of cases, the predicted ages exactly matched the actual ages. A variation of 1−4 years was seen in 75% of the cases. A variation of 6−7 years was seen in 15.6% of the cases. Conclusion:This study succeeded in most instances in predicting the ages of the study group and in arriving at a formula for age estimation between the ages of 25 and 45 years without using any invasive, costly, time - consuming, or troublesome method.

  1. Estimation of age in forensic medicine using multivariate approach to image analysis

    DEFF Research Database (Denmark)

    Kucheryavskiy, Sergey V.; Belyaev, Ivan; Fominykh, Sergey

    2009-01-01

    A new method for victims' age estimation, based on the image processing and analysis of remains bones structure, is proposed. Digital images of lumbar vertebras cuts were used as a major information source. The age related properties were extracted from the images using classic texture analysis...... approach based on statistical analysis of grey-level co-occurrence matrix, fractal analysis, wavelet transformation and Angle Measure Technique. Projection on latent structures regression was chosen for calibration and prediction. The method has been applied to 70 male and 63 female individuals aged from...

  2. Validation of age estimation in the Harp seal, Phoca groenlandica, using dentinal annuli

    OpenAIRE

    W D Bowen; Sergeant, David E.; Øritsland, Torger

    1983-01-01

    We investigated the validity and accuracy of age estimation in harp seals, Phoca groenlandica, using a sample of 155 known-age teeth from seals age 3 mo to 10 yr. Under transmitted light, transverse sections of harp seal canine teeth showed distinct incremental growth layers (IGLs) in the dentine. The first growth-layer group (GLG), representing 1st-year growth, consists of two IGLs: an outer layer of opaque dentine, bounded by the neonatal line, and an inner layer of translucent dentine. Sub...

  3. Estimating allele age and selection coefficient from Time-serial data

    DEFF Research Database (Denmark)

    Malaspinas, Anna Sapfo; Malaspinas, Orestis; Evans, Steven N.;

    2012-01-01

    age of an allele from time-serial data. Our method can be used for allele frequencies sampled from a single diallelic locus. The transition probabilities are calculated by approximating the standard diffusion equation of the Wright–Fisher model with a one-step process. We show that our method...... the age of the allele, it is possible to gain traction on the important problem of distinguishing selection on new mutations from selection on standing variation. In this coat color example for instance, we estimate the age of this allele, which is found to predate domestication....

  4. Estimation of biological age on atomic bomb survivors by multivariate analysis

    International Nuclear Information System (INIS)

    The subject was 415 persons picked up from about 3000 persons admitted to human dock of Hiroshima Red Cross Hospital, according to the selective standards of blood pressure, the number of erythrocyte, value of blood sugar and PSP value. The subjects were classified into the nonexposed group, the group exposed within 2 km from the hypocenter and the group exposed over 2 km + the group of entrants by sex. Age ranged from 30 to eighties. The examination items were 14 items effective for estimation of biological age of the aged. Calculation of the mean value and standard deviation by each group, simple correlation analysis, multivariate analysis and multiregression analysis were made by using computer, and then estimated age and degree of aging were calculated. The exposed within 2 km showed accelerated aging of 2 - 3 years in male and 4 - 6 years in female as compared with nonexposed, and 1 - 3 years in male and 1 - 6 years in female as compared with the exposed over 2 km + the entrants. The accelerated aging by A-bomb effect was not recognized in the exposed over 2 km + the entrants. (Kanao, N.)

  5. Comparison of Fundal Height Measurement and Ultrasonography for Estimation of Gestational Age

    Directory of Open Access Journals (Sweden)

    M Aflatoonian

    2008-07-01

    Full Text Available Introduction: Estimation of gestational age is an essential component of prenatal care. Gestational age is estimated by Last Menopausal Period, fundal height and ultrasonography. Serial measurment of fundal height and comparison with LMP predicts the G.A more accurately. Since nowadays, ultrasonography is used more frequently during pregnancy, patients have to bear more expenses. But we can use serial measurement of fundal height for determination of G.A. This method is cheap, reliable and easy for assessment of G.A and fetal growth in pregnancies without serious complications. In this study, we compared the accuracy of Fundal Height Measurement And Ultrasonography for estimation of gestational age. Methods: In this cross sectional study we investigated and compared the accuracy of fundal height measurement and ultrasonography in estimation of G.A. A total of 140 pregnant mothers were selected from patients referring to gynecology and obstetrics clinic of Doctor Mojibian and Shahid Sadughi hospitals in Yazd. Gestational age of these patients were estimated two times; measurement of fundal height and ultrasonography. Collected data was analyzed with SPSS11.5 program and Pearson correllation statistical test. Results: This pregnant mothers were identified by some criteria. In these mothers, the G.A was estimated by ultrasonography (BPD,FL and measurement of fundal height at G.A of 22-25 weeks, 22-25 weeks, and then at G.A of 25 to 28 weeks. Conclusion: The results showed that measurement of fundal height like sonography has a high a high rate of accuracy for estimation of G.A.

  6. Estimating growth of tropical tunas in the Indian Ocean using tag-recapture data and otolith-based age estimates

    OpenAIRE

    Eveson, J.P.; Million, J.; Sardenne, Fany; Le Croizier, G.

    2015-01-01

    A growth model from which the expected age of a fish can be estimated based on its length is a key component to most stock assessments. For the three tropical tuna species in the Indian Ocean - yellowfin (YET; Thunnus albacares), bigeye (BET; T. obesus) and skipjack (SKJ; Katsuwonus pelamis) - information about growth has been very limited until recently, when data from a large-scale Indian Ocean tuna tagging program became available. In this paper, parametric growth models were fit to tag-re...

  7. Estimation of sex and age of ''virtual skeletons''-a feasibility study

    International Nuclear Information System (INIS)

    This article presents a feasibility study with the objective of investigating the potential of multi-detector computed tomography (MDCT) to estimate the bone age and sex of deceased persons. To obtain virtual skeletons, the bodies of 22 deceased persons with known age at death were scanned by MDCT using a special protocol that consisted of high-resolution imaging of the skull, shoulder girdle (including the upper half of the humeri), the symphysis pubis and the upper halves of the femora. Bone and soft-tissue reconstructions were performed in two and three dimensions. The resulting data were investigated by three anthropologists with different professional experience. Sex was determined by investigating three-dimensional models of the skull and pelvis. As a basic orientation for the age estimation, the complex method according to Nemeskeri and co-workers was applied. The final estimation was effected using additional parameters like the state of dentition, degeneration of the spine, etc., which where chosen individually by the three observers according to their experience. The results of the study show that the estimation of sex and age is possible by the use of MDCT. Virtual skeletons present an ideal collection for anthropological studies, because they are obtained in a non-invasive way and can be investigated ad infinitum. (orig.)

  8. Reliability of Third Molar Development for Age Estimation by Radiographic Examination (Demirjian’s Method)

    OpenAIRE

    Naik, Sushil B; Swapnil N Patil; Kamble, Seema D; Mowade, Tushar; Motghare, Pavan

    2014-01-01

    Introduction: Dental age estimation methods are of particular value because teeth are highly resistant to mechanical, chemical, or physical impacts and time. Teeth are the strongest parts in the human body and are therefore very resistant to external influences, such as extreme temperatures, explosions, and other extreme conditions, which make them available for extensive postmortem periods.

  9. Application of aging methods to estimate long term performance of secondary materials for road construction

    NARCIS (Netherlands)

    Akbarnejad, S.; Houben, L.J.M.; Molenaar, A.A.A.

    2012-01-01

    Long term performance of secondary materials is becoming a challenging aspect in road construction since due to their benefits they are being used on a large scale, but on the other hand their future behaviors are difficult to estimate. In this study, aging is proposed as a means of exploring the lo

  10. The biology behind the counts: tooth development related to age estimation in beluga (Delphinapterus leucas

    Directory of Open Access Journals (Sweden)

    Barbara E Stewart

    2014-11-01

    Full Text Available The widely accepted method of determining ages of beluga is to count dentine growth layer groups (GLGs in median, longitudinal sections of a tooth. It is essential to understand how these growth layers form and to consider developmental factors that can confound their enumeration to be able to provide meaningful age estimates. Here we provide information on, and illustrate, the developmental biology of beluga teeth as it relates to interpreting GLGs. Key factors are: evaluating the presence and occlusal wear of fetal dentine; interpreting early-formed diagnostic features such as the neonatal line; assessing the last-formed growth layer adjacent to the pulp cavity; identifying the presence of nodes at the dentine-cementum interface to assist in counting GLGs; and recognizing  pulp stones and accessory lines in the dentine which may hinder the age estimate process.

  11. Probabilistic graphical models to deal with age estimation of living persons.

    Science.gov (United States)

    Sironi, Emanuele; Gallidabino, Matteo; Weyermann, Céline; Taroni, Franco

    2016-03-01

    Due to the rise of criminal, civil and administrative judicial situations involving people lacking valid identity documents, age estimation of living persons has become an important operational procedure for numerous forensic and medicolegal services worldwide. The chronological age of a given person is generally estimated from the observed degree of maturity of some selected physical attributes by means of statistical methods. However, their application in the forensic framework suffers from some conceptual and practical drawbacks, as recently claimed in the specialised literature. The aim of this paper is therefore to offer an alternative solution for overcoming these limits, by reiterating the utility of a probabilistic Bayesian approach for age estimation. This approach allows one to deal in a transparent way with the uncertainty surrounding the age estimation process and to produce all the relevant information in the form of posterior probability distribution about the chronological age of the person under investigation. Furthermore, this probability distribution can also be used for evaluating in a coherent way the possibility that the examined individual is younger or older than a given legal age threshold having a particular legal interest. The main novelty introduced by this work is the development of a probabilistic graphical model, i.e. a Bayesian network, for dealing with the problem at hand. The use of this kind of probabilistic tool can significantly facilitate the application of the proposed methodology: examples are presented based on data related to the ossification status of the medial clavicular epiphysis. The reliability and the advantages of this probabilistic tool are presented and discussed. PMID:25794687

  12. Hierarchical Bayesian analysis to incorporate age uncertainty in growth curve analysis and estimates of age from length: Florida manatee (Trichechus manatus) carcasses

    Science.gov (United States)

    Schwarz, L.K.; Runge, M.C.

    2009-01-01

    Age estimation of individuals is often an integral part of species management research, and a number of ageestimation techniques are commonly employed. Often, the error in these techniques is not quantified or accounted for in other analyses, particularly in growth curve models used to describe physiological responses to environment and human impacts. Also, noninvasive, quick, and inexpensive methods to estimate age are needed. This research aims to provide two Bayesian methods to (i) incorporate age uncertainty into an age-length Schnute growth model and (ii) produce a method from the growth model to estimate age from length. The methods are then employed for Florida manatee (Trichechus manatus) carcasses. After quantifying the uncertainty in the aging technique (counts of ear bone growth layers), we fit age-length data to the Schnute growth model separately by sex and season. Independent prior information about population age structure and the results of the Schnute model are then combined to estimate age from length. Results describing the age-length relationship agree with our understanding of manatee biology. The new methods allow us to estimate age, with quantified uncertainty, for 98% of collected carcasses: 36% from ear bones, 62% from length.

  13. Age Estimation-Based Soft Biometrics Considering Optical Blurring Based on Symmetrical Sub-Blocks for MLBP

    Directory of Open Access Journals (Sweden)

    Dat Tien Nguyen

    2015-10-01

    Full Text Available Because of its many useful applications, human age estimation has been considered in many previous studies as a soft biometrics. However, most existing methods of age estimation require a clear and focused facial image as input in order to obtain a trustworthy estimation result; otherwise, the methods might produce increased estimation error when an image of poor quality is used as input. Image blurring is one of major factors that affect estimation accuracies because it can cause a face to appear younger (i.e., reduce the age feature in the face region. Therefore, we propose a new human age estimation method that is robust even with an image that has the optical blurring effect by using symmetrical focus mask and sub-blocks for multi-level local binary pattern (MLBP. Experiment results show that the proposed method can enhance age estimation accuracy compared with the conventional system, which does not consider the effects of blurring.

  14. Weight Estimation Tool for Children Aged 6 to 59 Months in Limited-Resource Settings

    Science.gov (United States)

    2016-01-01

    Importance A simple, reliable anthropometric tool for rapid estimation of weight in children would be useful in limited-resource settings where current weight estimation tools are not uniformly reliable, nearly all global under-five mortality occurs, severe acute malnutrition is a significant contributor in approximately one-third of under-five mortality, and a weight scale may not be immediately available in emergencies to first-response providers. Objective To determine the accuracy and precision of mid-upper arm circumference (MUAC) and height as weight estimation tools in children under five years of age in low-to-middle income countries. Design This was a retrospective observational study. Data were collected in 560 nutritional surveys during 1992–2006 using a modified Expanded Program of Immunization two-stage cluster sample design. Setting Locations with high prevalence of acute and chronic malnutrition. Participants A total of 453,990 children met inclusion criteria (age 6–59 months; weight ≤ 25 kg; MUAC 80–200 mm) and exclusion criteria (bilateral pitting edema; biologically implausible weight-for-height z-score (WHZ), weight-for-age z-score (WAZ), and height-for-age z-score (HAZ) values). Exposures Weight was estimated using Broselow Tape, Hong Kong formula, and database MUAC alone, height alone, and height and MUAC combined. Main Outcomes and Measures Mean percentage difference between true and estimated weight, proportion of estimates accurate to within ± 25% and ± 10% of true weight, weighted Kappa statistic, and Bland-Altman bias were reported as measures of tool accuracy. Standard deviation of mean percentage difference and Bland-Altman 95% limits of agreement were reported as measures of tool precision. Results Database height was a more accurate and precise predictor of weight compared to Broselow Tape 2007 [B], Broselow Tape 2011 [A], and MUAC. Mean percentage difference between true and estimated weight was +0.49% (SD = 10

  15. Age estimates of globular clusters in the Milky Way: constraints on cosmology.

    Science.gov (United States)

    Krauss, Lawrence M; Chaboyer, Brian

    2003-01-01

    Recent observations of stellar globular clusters in the Milky Way Galaxy, combined with revised ranges of parameters in stellar evolution codes and new estimates of the earliest epoch of globular cluster formation, result in a 95% confidence level lower limit on the age of the Universe of 11.2 billion years. This age is inconsistent with the expansion age for a flat Universe for the currently allowed range of the Hubble constant, unless the cosmic equation of state is dominated by a component that violates the strong energy condition. This means that the three fundamental observables in cosmology-the age of the Universe, the distance-redshift relation, and the geometry of the Universe-now independently support the case for a dark energy-dominated Universe. PMID:12511641

  16. Estimation of fracture toughness of cast stainless steels during thermal aging in LWR systems

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting the change in fracture toughness of cast stainless steel components due to thermal aging during service in light water rectors (LWRs) at 280--330 degrees C (535--625 degrees F). The fracture toughness J-R curve and Charpy-impact energy of aged cast stainless steels are estimated from known mineral in formation. Fracture toughness of a specific cast stainless steel is estimated from the extent and kinetics of thermal embrittlement. The extent of thermal embrittlement is characterized by the room-temperature ''normalized'' Charpy-impact energy. A correlation for the extent of embrittlement at ''saturation,'' i.e., the minimum impact energy that would be achieved for the material after long-term aging, is given in terms of a material parameter, Φ, which is determined from the chemical composition. The fracture toughness J-R curve for the material is then obtained from correlations between room-temperature Charpy-impact energy and fracture toughness parameters. Fracture toughness as a function of time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which is determined from chemical composition. A common ''lower-bound'' J-R curve for cast stainless steels with unknown chemical composition is also defined for a given material specification, ferrite content, and temperature. Examples for estimating impact strength and fracture toughness of cast stainless steel components during reactor service are describes. 24 refs., 39 figs., 2 tabs

  17. Estimating brain age using high-resolution pattern recognition: Younger brains in long-term meditation practitioners.

    Science.gov (United States)

    Luders, Eileen; Cherbuin, Nicolas; Gaser, Christian

    2016-07-01

    Normal aging is known to be accompanied by loss of brain substance. The present study was designed to examine whether the practice of meditation is associated with a reduced brain age. Specific focus was directed at age fifty and beyond, as mid-life is a time when aging processes are known to become more prominent. We applied a recently developed machine learning algorithm trained to identify anatomical correlates of age in the brain translating those into one single score: the BrainAGE index (in years). Using this validated approach based on high-dimensional pattern recognition, we re-analyzed a large sample of 50 long-term meditators and 50 control subjects estimating and comparing their brain ages. We observed that, at age fifty, brains of meditators were estimated to be 7.5years younger than those of controls. In addition, we examined if the brain age estimates change with increasing age. While brain age estimates varied only little in controls, significant changes were detected in meditators: for every additional year over fifty, meditators' brains were estimated to be an additional 1month and 22days younger than their chronological age. Altogether, these findings seem to suggest that meditation is beneficial for brain preservation, effectively protecting against age-related atrophy with a consistently slower rate of brain aging throughout life. PMID:27079530

  18. Threshold groundwater ages and young water fractions estimated from 3H, 3He, and 14C

    Science.gov (United States)

    Kirchner, James; Jasechko, Scott

    2016-04-01

    It is widely recognized that a water sample taken from a running stream is not described by a single age, but rather by a distribution of ages. It is less widely recognized that the same principle holds true for groundwaters, as indicated by the commonly observed discordances between model ages obtained from different tracers (e.g., 3H vs 14C) in the same sample. Water age distributions are often characterized by their mean residence times (MRT's). However, MRT estimates are highly uncertain because they depend on the shape of the assumed residence time distribution (in particular on the thickness of the long-time tail), which is difficult or impossible to constrain with data. Furthermore, because MRT's are typically nonlinear functions of age tracer concentrations, they are subject to aggregation bias. That is, MRT estimates derived from a mixture of waters with different ages (and thus different tracer concentrations) will systematically underestimate the mixture's true mean age. Here, building on recent work with stable isotope tracers in surface waters [1-3], we present a new framework for using 3H, 3He and 14C to characterize groundwater age distributions. Rather than describing groundwater age distributions by their MRT, we characterize them by the fraction of the distribution that is younger or older than a threshold age. The threshold age that separates "young" from "old" water depends on the characteristics of the specific tracer, including its history of atmospheric inputs. Our approach depends only on whether a given slice of the age distribution is younger or older than the threshold age, but not on how much younger or older it is. Thus our approach is insensitive to the tails of the age distribution, and is therefore relatively unaffected by uncertainty in the distribution's shape. Here we show that concentrations of 3H, 3He, and 14C are almost linearly related to the fractions of water that are younger or older than specified threshold ages. These

  19. The biochemical estimation of age in Euphausiids: Laboratory calibration and field comparisons

    Science.gov (United States)

    Harvey, H. R.; Ju, Se-J.; Son, S.-K.; Feinberg, L. R.; Shaw, C. T.; Peterson, W. T.

    2010-04-01

    Euphausiids play a key role in many marine ecosystems as a link between primary producers and top predators. Understanding their demographic (i.e. age) structure is an essential tool to assess growth and recruitment as well as to determine how changes in environmental conditions might alter their condition and distribution. Age determination of crustaceans cannot be accomplished using traditional approaches, and here we evaluate the potential for biochemical products of tissue metabolism (termed lipofuscins) to determine the demographic structure of euphausiids in field collections . Lipofuscin was extracted from krill neural tissues (eye and eye-stalk), quantified using fluorescent intensity and normalized to tissue protein content to allow comparisons across animal sizes. Multiple fluorescent components from krill were observed, with the major product having a maximum fluorescence at excitation of 355 nm and emission of 510 nm. Needed age calibration of lipofuscin accumulation in Euphausia pacifica was accomplished using known-age individuals hatched and reared in the laboratory for over one year. Lipofuscin content extracted from neural tissues of laboratory-reared animals was highly correlated with the chronological age of animals ( r=0.87). Calibrated with laboratory lipofuscin accumulation rates, field-collected sub-adult and adult E. pacifica in the Northeast Pacific were estimated to be older than 100 days and younger than 1year. Comparative data for the Antarctic krill, E. superba showed much higher lipofuscin values suggesting a much longer lifespan than the more temperate species, E. pacifica. These regional comparisons suggest that biochemical indices allow a practical approach to estimate population age structure of diverse populations, and combined with other measurements can provide estimates of vital rates (i.e. longevity, mortality, growth) for krill populations in dynamic environments.

  20. A quantitative method for estimation of volume changes in arachnoid foveae with age.

    Science.gov (United States)

    Duray, Stephen M; Martel, Stacie S

    2006-03-01

    Age-related changes of arachnoid foveae have been described, but objective, quantitative analyses are lacking. A new quantitative method is presented for estimation of change in total volume of arachnoid foveae with age. The pilot sample consisted of nine skulls from the Palmer Anatomy Laboratory. Arachnoid foveae were filled with sand, which was extracted using a vacuum pump. Mass was determined with an analytical balance and converted to volume. A reliability analysis was performed using intraclass correlation coefficients. The method was found to be highly reliable (intraobserver ICC = 0.9935, interobserver ICC = 0.9878). The relationship between total volume and age was then examined in a sample of 63 males of accurately known age from the Hamann-Todd collection. Linear regression analysis revealed no statistically significant relationship between total volume and age, or foveae frequency and age (alpha = 0.05). Development of arachnoid foveae may be influenced by health factors, which could limit its usefulness in aging. PMID:16566755

  1. AGE ESTIMATION BY USING ERUPTION OF PERMANENT TEETH: A COMPARATIVE STUDY IN LOCAL POPULATION TO PROVE/DISPROVE AGES OF ERUPTION USED IN ROUTINE PRACTICE

    Directory of Open Access Journals (Sweden)

    Tamilmani

    2015-10-01

    Full Text Available Estimation of age is one of the important medico legal works where medical knowledge is applied in rendering Justice to the public and to the state. Assessment of age is often required in civil and criminal litigations. Assessment of age of an individual by examination of teeth is one of the universally accepted methods of age estimation. In a developing country like India, a large number of people are illiterate and have no knowledge or records of their date of birth which is required by law enforcing age ncies in matters like, criminal responsibilities, identification, judicial punishment, consent, rape, criminal abortion, employment, attainment of majority, kidnapping and prostitution (Pathak et al, 1999. Age estimation is also required for admission pur poses at the time of schooling, joining services and during retirement. Estimation of age is also required for giving old age benefits. Hence, scientific determination of age is very important. Key words; Eruption of permanent teeth, J udicial punishment , Legal sections , Estimation of age in both sexes.

  2. Why Was Kelvin's Estimate of the Earth's Age Wrong?

    Science.gov (United States)

    Lovatt, Ian; Syed, M. Qasim

    2014-01-01

    This is a companion to our previous paper in which we give a published example, based primarily on Perry's work, of a graph of ln "y" versus "t" when "y" is an exponential function of "t". This work led us to the idea that Lord Kelvin's (William Thomson's) estimate of the Earth's age was…

  3. On the automatic detection of otolith features for fish species identification and their age estimation

    OpenAIRE

    Sória Pérez, José A. (José Antonio)

    2013-01-01

    This thesis deals with the automatic detection of features in signals, either extracted from photographs or captured by means of electronic sensors, and its possible application in the detection of morphological structures in fish otoliths so as to identify species and estimate their age at death. From a more biological perspective, otoliths, which are calcified structures located in the auditory system of all teleostean fish, constitute one of the main elements employed in the study and mana...

  4. Reliability of age estimation using Demirjian′s 8 teeth method and India specific formula

    Directory of Open Access Journals (Sweden)

    V Jayanth Kumar

    2011-01-01

    Full Text Available Introduction: The estimation of the age of a person has been an archaic exercise, and since decades even dentists have contributed to this science with several methods through radiography. The tooth with its developmental stages provides us with a non-invasive modality to determine the age of the person. Aim: To evaluate the reliability of age estimation using Demirjian′s 8 teeth method following the French maturity scores and India specific formula. Materials and Methods: The study was conducted on 121 archived digital orthopantamographs which were predominantly pre-treatment orthodontic radiographs from patients without any obvious developmental anomalies. The radiographs were divided into two gender specific groups and further sub-divided into two smaller groups of 7-16 years and 16.1-23 years. The radiographs were evaluated as per Demirjian′s criteria and age was calculated using the formula developed for the Indian population. Results: The results showed that the mean absolute error for the study sample was 1.18 years; in 57.9% of cases the error rate was within ±1 year. The mean absolute error in males (7-16 years was 1.2 years; in males (16.1-23 years was 1.3 years; in females (7-16 years was 0.95 years and in females (16.1-23 years was 1.16 years. Conclusion: The age estimation using this method narrows down the error rate to just over one year making this method reliable. However the inclusion of third molar increases the error rates in the older individuals within the sample.

  5. Estimating dose rates to organs as a function of age following internal exposure to radionuclides

    International Nuclear Information System (INIS)

    The AGEDOS methodology allows estimates of dose rates, as a function of age, to radiosensitive organs and tissues in the human body at arbitrary times during or after internal exposure to radioactive material. Presently there are few, if any, radionuclides for which sufficient metabolic information is available to allow full use of all features of the methodology. The intention has been to construct the methodology so that optimal information can be gained from a mixture of the limited amount of age-dependent, nuclide-specific data and the generally plentiful age-dependent physiological data now available. Moreover, an effort has been made to design the methodology so that constantly accumulating metabolic information can be incorporated with minimal alterations in the AGEDOS computer code. Some preliminary analyses performed by the authors, using the AGEDOS code in conjunction with age-dependent risk factors developed from the A-bomb survivor data and other studies, has indicated that the doses and subsequent risks of eventually experiencing radiogenic cancers may vary substantially with age for some exposure scenarios and may be relatively invariant with age for other scenarios. We believe that the AGEDOS methodology provides a convenient and efficient means for performing the internal dosimetry

  6. Foraminiferal faunal estimates of paleotemperature: Circumventing the no-analog problem yields cool ice age tropics

    Science.gov (United States)

    Mix, A.C.; Morey, A.E.; Pisias, N.G.; Hostetler, S.W.

    1999-01-01

    The sensitivity of the tropics to climate change, particularly the amplitude of glacial-to-interglacial changes in sea surface temperature (SST), is one of the great controversies in paleoclimatology. Here we reassess faunal estimates of ice age SSTs, focusing on the problem of no-analog planktonic foraminiferal assemblages in the equatorial oceans that confounds both classical transfer function and modern analog methods. A new calibration strategy developed here, which uses past variability of species to define robust faunal assemblages, solves the no-analog problem and reveals ice age cooling of 5??to 6??C in the equatorial current systems of the Atlantic and eastern Pacific Oceans. Classical transfer functions underestimated temperature changes in some areas of the tropical oceans because core-top assemblages misrepresented the ice age faunal assemblages. Our finding is consistent with some geochemical estimates and model predictions of greater ice age cooling in the tropics than was inferred by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981] and thus may help to resolve a long-standing controversy. Our new foraminiferal transfer function suggests that such cooling was limited to the equatorial current systems, however, and supports CLIMAP's inference of stability of the subtropical gyre centers.

  7. Radiation risk associated with radiologocal procedures for age estimation for forensic purposes

    International Nuclear Information System (INIS)

    Aim: Age estimation for forensic purposes is, in general, based on a radiogram of the left hand or an orthopantomogram of the teeth. Two examples are given exemplifying the principal procedure that may be applied for estimating the radiation risks associated with the radiological examinations considered. Method: Mortality risks were calculated using the risk coefficients of ICRP and the mass ratio of radiation-exposed portion to total organ. For a radiogram of the hand, a radiation dose of 0.15 mGy was adopted. For an orthopantomogram the following doses were used: Bone surface and red bone marrow 0.25 mGy, skin on the neck 0.56 mGy, thyroid gland 0.053 mGy. Results: Mortality risks obtained were 5.1 x 10-8 for a radiogram of the hand and 1.8 x 10-7 for an orthopantomogram. For comparison, it was estimated that the calculated risks might be equivalent to the mortality risks associated with public road traffic during less than one hour or about 2.5 hours, respectively. Conclusions: The calculated radiation risks are of a similar order of magnitude as are the risks the respective person is exposed to on the way to the medical examination or to the court. However, the applicability and the limits of the radiological procedures applied for age estimation require extensive and critical discussion. (orig.)

  8. Age-specific survival estimates of King Eiders derived from satellite telemetry

    Science.gov (United States)

    Oppel, Steffen; Powell, Abby N.

    2010-01-01

    Age- and sex-specific survival and dispersal are important components in the dynamics and genetic structure of bird populations. For many avian taxa survival rates at the adult and juvenile life stages differ, but in long-lived species juveniles' survival is logistically challenging to study. We present the first estimates of hatch-year annual survival rates for a sea duck, the King Eider (Somateria spectabilis), estimated from satellite telemetry. From 2006 to 2008 we equipped pre-fiedging King Eiders with satellite transmitters on breeding grounds in Alaska and estimated annual survival rates during their first 2 years of life with known-fate models. We compared those estimates to survival rates of adults marked in the same area from 2002 to 2008. Hatch-year survival varied by season during the first year of life, and model-averaged annual survival rate was 0.67 (95% CI: 0.48–0.80). We did not record any mortality during the second year and were therefore unable to estimate second-year survival rate. Adults' survival rate was constant through the year (0.94, 95% CI: 0.86–0.97). No birds appeared to breed during their second summer. While 88% of females with an active transmitter (n = 9) returned to their natal area at the age of 2 years, none of the 2-year old males (n = 3) did. This pattern indicates that females' natal philopatry is high and suggests that males' higher rates of dispersal may account for sex-specific differences in apparent survival rates of juvenile sea ducks when estimated with mark—recapture methods.

  9. Estimation of Energy Consumption and Greenhouse Gas Emissions considering Aging and Climate Change in Residential Sector

    Science.gov (United States)

    Lee, M.; Park, C.; Park, J. H.; Jung, T. Y.; Lee, D. K.

    2015-12-01

    The impacts of climate change, particularly that of rising temperatures, are being observed across the globe and are expected to further increase. To counter this phenomenon, numerous nations are focusing on the reduction of greenhouse gas (GHG) emissions. Because energy demand management is considered as a key factor in emissions reduction, it is necessary to estimate energy consumption and GHG emissions in relation to climate change. Further, because South Korea is the world's fastest nation to become aged, demographics have also become instrumental in the accurate estimation of energy demands and emissions. Therefore, the purpose of this study is to estimate energy consumption and GHG emissions in the residential sectors of South Korea with regard to climate change and aging to build more accurate strategies for energy demand management and emissions reduction goals. This study, which was stablished with 2010 and 2050 as the base and target years, respectively, was divided into a two-step process. The first step evaluated the effects of aging and climate change on energy demand, and the second estimated future energy use and GHG emissions through projected scenarios. First, aging characteristics and climate change factors were analyzed by using the logarithmic mean divisia index (LMDI) decomposition analysis and the application of historical data. In the analysis of changes in energy use, the effects of activity, structure, and intensity were considered; the degrees of contribution were derived from each effect in addition to their relations to energy demand. Second, two types of scenarios were stablished based on this analysis. The aging scenarios are business as usual and future characteristics scenarios, and were used in combination with Representative Concentration Pathway (RCP) 2.6 and 8.5. Finally, energy consumption and GHG emissions were estimated by using a combination of scenarios. The results of these scenarios show an increase in energy consumption

  10. A case of an adoptive girl with precocious puberty: the problem of age estimation.

    Science.gov (United States)

    De Donno, Antonio; Roca, Roberta; Introna, Francesco; Santoro, Valeria

    2013-09-10

    Age estimation is one of the main tasks of forensic anthropology and odontology, both on the dead and the living. In living subjects, age estimation may be used to establish an individual's status as a minor in cases involving adoption, criminal responsibility, child pornography, and those seeking asylum, especially where adequate identification documents are lacking. The authors report a case about age assessment of a girl born in Mbujimayi (Democratic Republic of Congo) and later adopted in Italy. The birth certificate issued after finding the child in a state of abandonment (in December 2007), bore date of 12.12.2004, but this was in contrast with the year of birth - 2003 - stated on the certification available to the center that had provided accommodation to the girl in Africa. Her adoptive parents reported that the child had been diagnosed with precocious puberty and was thus under treatment. She weighed 32.5 kg and was 132.5 cm tall. Body mass index (BMI) corresponded to the range between 9.5 and 14 years of age. The assessment of maturity indicators (sexual characteristics) placed the child at the lower limits of Stage II of Tanner's classification (sparse growth of long, slightly darkened, downy straight pubic hair; elevation of the breast and nipple as a small mound with increased diameter of the areolae). The skeletal age was determined by taking X-rays of the hand and wrist using Fels, TW2 and Greulich and Pyle methods. Dental growth was assessed through orthopantomogram using Demirjian's technique. The methods applied were adjusted considering the studies on African population found in the literature, and a skeletal and dental age of 10 years was established. Afterwards, the wrist X-rays performed at the Children's Hospital of Bari, 7 months before our investigation, revealed a skeletal age of 7 years. This evidence showed that, despite the treatment the child had promptly initiated, early puberty had influenced the skeletal growth with an acceleration

  11. An evaluation of age estimation using teeth from South Asian River dolphins (Platanistidae

    Directory of Open Access Journals (Sweden)

    Christina H Lockyer

    2014-12-01

    Full Text Available The South Asian river dolphins (Platanista gangetica minor and P. g. gangetica are endangered, geographically isolated, freshwater cetaceans. Accurate age estimation of individuals is an important aspect of population biology as it is used for calculating parameters such as age at maturity and reproduction, longevity, and growth and survival rates. However this has never been comprehensively studied for this endangered cetacean family. A sample of 41 teeth from 29 skulls stored in museum collections was available. We compared two different aging methods to select the most appropriate. This involved decalcification and freeze-sectioning of teeth at variable thicknesses (10–25 micron, and staining with 1 Toluidine Blue, or 2 Ehrlichs Acid Haematoxylin. Stains were then compared for readability of Growth Layer Groups (GLG. The optimum section was found at 20 micron using Erhlichs Acid Haematoxylin. Both dentinal and cemental GLG were readable and comparable, but cemental GLG were generally easier to interpret because they were better defined. Ages varied from newborn / young of year (with none or only a neonatal line present to a maximum age of 30 GLG. There is currently no validation available for GLG deposition rate, but it is likely annual because of the extreme seasonal changes in the river habitat. 

  12. Discriminating the effects of phylogenetic hypothesis, tree resolution and clade age estimates on phylogenetic signal measurements.

    Science.gov (United States)

    Seger, G D S; Duarte, L D S; Debastiani, V J; Kindel, A; Jarenkow, J A

    2013-09-01

    Understanding how species traits evolved over time is the central question to comprehend assembly rules that govern the phylogenetic structure of communities. The measurement of phylogenetic signal (PS) in ecologically relevant traits is a first step to understand phylogenetically structured community patterns. The different methods available to estimate PS make it difficult to choose which is most appropriate. Furthermore, alternative phylogenetic tree hypotheses, node resolution and clade age estimates might influence PS measurements. In this study, we evaluated to what extent these parameters affect different methods of PS analysis, and discuss advantages and disadvantages when selecting which method to use. We measured fruit/seed traits and flowering/fruiting phenology of endozoochoric species occurring in Southern Brazilian Araucaria forests and evaluated their PS using Mantel regressions, phylogenetic eigenvector regressions (PVR) and K statistic. Mantel regressions always gave less significant results compared to PVR and K statistic in all combinations of phylogenetic trees constructed. Moreover, a better phylogenetic resolution affected PS, independently of the method used to estimate it. Morphological seed traits tended to show higher PS than diaspores traits, while PS in flowering/fruiting phenology depended mostly on the method used to estimate it. This study demonstrates that different PS estimates are obtained depending on the chosen method and the phylogenetic tree resolution. This finding has implications for inferences on phylogenetic niche conservatism or ecological processes determining phylogenetic community structure. PMID:23368095

  13. Estimation of gestational age in Egyptian native goats by ultrasonographic fetometry.

    Science.gov (United States)

    Karen, Aly M; Fattouh, El-Sayed M; Abu-Zeid, Saber S

    2009-08-01

    The main aim of the present study was to estimate the gestational age of Egyptian goats by B-mode ultrasound measurement of embryonic or fetal parts throughout pregnancy. Trans-rectal (TR) ultrasonography (7 MHz) was carried out on 15 pregnant Egyptian does at Day 10 post mating on alternate days until Day 25 and then once at 3-5-day intervals until Day 50. Trans-abdominal (TA) ultrasonography (3.5-5 MHz) was carried out on the same animals from Days 25 to 130 at 3-5-day intervals. After imaging the embryo or the fetus, the following parameters were measured: length of the embryo or fetus (CRL), heart rate (FHR), biparital diameter (BPD), trunk diameter (TD), placentome size (PS), umbilical cord diameter (UCD) and femur length (FL). The average of days at which the embryonic vesicle was first determined by TR and TA ultrasonography was 16.98+/-1.97 and 27.87+/-3.48, respectively. The embryo proper with a beating heart was first determined by TR and TA ultrasonography at an average of 22.36+/-2.66 and 30.36+/-4.75 days, respectively. All the fetal measures were significantly (P or =90) with the gestational age. In conclusion, the age of embryo or fetus in Egyptian does can be estimated by ultrasound measuring the crown rump length, biparital diameter, trunk diameter, placentome size, umbilical cord diameter and femur length. PMID:18805657

  14. Hierarchical Bayesian approach for estimating physical properties in spiral galaxies: Age Maps for M74

    CERN Document Server

    Gil, M Carmen Sánchez; Alfaro, Emilio J; Pérez, Enrique; Sarro, Luis M

    2015-01-01

    One of the fundamental goals of modern Astronomy is to estimate the physical parameters of galaxies from images in different spectral bands. We present a hierarchical Bayesian model for obtaining age maps from images in the \\Ha\\ line (taken with Taurus Tunable Filter (TTF)), ultraviolet band (far UV or FUV, from GALEX) and infrared bands (24, 70 and 160 microns ($\\mu$m), from Spitzer). As shown in S\\'anchez-Gil et al. (2011), we present the burst ages for young stellar populations in the nearby and nearly face on galaxy M74. As it is shown in the previous work, the \\Ha\\ to FUV flux ratio gives a good relative indicator of very recent star formation history (SFH). As a nascent star-forming region evolves, the \\Ha\\ line emission declines earlier than the UV continuum, leading to a decrease in the \\Ha\\/FUV ratio. Through a specific star-forming galaxy model (Starburst 99, SB99), we can obtain the corresponding theoretical ratio \\Ha\\ / FUV to compare with our observed flux ratios, and thus to estimate the ages of...

  15. Relative Expression of Indicators for Wound Age Estimation in Forensic Pathology

    Institute of Scientific and Technical Information of China (English)

    DU Qiu-xiang; WANG Xiao-wei; ZHANG Lei; LI San-qiang; GAO Cai-rong; WANG Ying-yuan; SUN Jun-hong

    2015-01-01

    Objective In order to understand which kind of function genes play an important role for es-timating wound age, the variation of difference genes’ mRNA expression were compared after injury. Methods T he mRNA expression levels of seven candidate genes (ICAM-1, NF-κB, MX2, MT1, MT2, sTnI, and Cox6c) were analyzed in contused rat skeletal muscle at different time points using real-time fluorescent quantitative PC R (R T-qPC R ). T he rawC t values were normalized relative to that of RPL32 mRNA , and converted to standard C t values. A t each time point after injury, the standard deviations (SD ) of the standard C t values were calculated by SPSS. Results T he expression trends of the seven genes were all found to be related to wound age, but there were lower variation coefficients and greater reliability of sTnI and Cox6c when compared with other genes. Conclusion T he genes encoding struc-tural proteins or proteins that performbasic functions can be suitable for wound age estimation.

  16. Efficiency of wear and decalcification technique for estimating the age of estuarine dolphin Sotalia guianensis

    Indian Academy of Sciences (India)

    Nicolle V Sydney; Emygdio La Monteiro-Filho

    2011-03-01

    Most techniques used for estimating the age of Sotalia guianensis (van Bénéden, 1864) (Cetacea; Delphinidae) are very expensive, and require sophisticated equipment for preparing histological sections of teeth. The objective of this study was to test a more affordable and much simpler method, involving of the manual wear of teeth followed by decalcification and observation under a stereomicroscope. This technique has been employed successfully with larger species of Odontoceti. Twenty-six specimens were selected, and one tooth of each specimen was worn and demineralized for growth layers reading. Growth layers were evidenced in all specimens; however, in 4 of the 26 teeth, not all the layers could be clearly observed. In these teeth, there was a significant decrease of growth layer group thickness, thus hindering the layers count. The juxtaposition of layers hindered the reading of larger numbers of layers by the wear and decalcification technique. Analysis of more than 17 layers in a single tooth proved inconclusive. The method applied here proved to be efficient in estimating the age of Sotalia guianensis individuals younger than 18 years. This method could simplify the study of the age structure of the overall population, and allows the use of the more expensive methodologies to be confined to more specific studies of older specimens. It also enables the classification of the calf, young and adult classes, which is important for general population studies.

  17. Tropical dendrochemistry: A novel approach to estimate age and growth from ringless trees

    International Nuclear Information System (INIS)

    Although tropical forests play an active role in the global carbon cycle and climate, their growth history remains poorly characterized compared to other ecosystems on the planet. Trees are prime candidates for the extraction of paleoclimate archives as they can be probed sub-annually, are widely distributed and can live for over 1400 years. However, dendrochronological techniques have found limited applications in the tropics because trees often lack visible growth rings. Alternative methods exist (dendrometry, radio- and stable isotopes), but the derived records are either of short-duration, lack seasonal resolution or are prohibitively labor intensive to produce. Here, we show the first X-ray microprobe synchrotron record of calcium (Ca) from a ringless Miliusa velutina tree from Thailand and use it to estimate the tree's age and growth history. The Ca age model agrees within (le)2 years of bomb-radiocarbon age estimates and confirms that the cycles are seasonal. The amplitude of the Ca annual cycle is correlated significantly with growth and annual Ca maxima correlate with the amount of dry season rainfall. Synchrotron measurements are fast and producing sufficient numbers of replicated multi-century tropical dendrochemical climate records now seems analytically feasible

  18. Estimating Modifying Effect of Age on Genetic and Environmental Variance Components in Twin Models.

    Science.gov (United States)

    He, Liang; Sillanpää, Mikko J; Silventoinen, Karri; Kaprio, Jaakko; Pitkäniemi, Janne

    2016-04-01

    Twin studies have been adopted for decades to disentangle the relative genetic and environmental contributions for a wide range of traits. However, heritability estimation based on the classical twin models does not take into account dynamic behavior of the variance components over age. Varying variance of the genetic component over age can imply the existence of gene-environment (G×E) interactions that general genome-wide association studies (GWAS) fail to capture, which may lead to the inconsistency of heritability estimates between twin design and GWAS. Existing parametricG×Einteraction models for twin studies are limited by assuming a linear or quadratic form of the variance curves with respect to a moderator that can, however, be overly restricted in reality. Here we propose spline-based approaches to explore the variance curves of the genetic and environmental components. We choose the additive genetic, common, and unique environmental variance components (ACE) model as the starting point. We treat the component variances as variance functions with respect to age modeled by B-splines or P-splines. We develop an empirical Bayes method to estimate the variance curves together with their confidence bands and provide an R package for public use. Our simulations demonstrate that the proposed methods accurately capture dynamic behavior of the component variances in terms of mean square errors with a data set of >10,000 twin pairs. Using the proposed methods as an alternative and major extension to the classical twin models, our analyses with a large-scale Finnish twin data set (19,510 MZ twins and 27,312 DZ same-sex twins) discover that the variances of the A, C, and E components for body mass index (BMI) change substantially across life span in different patterns and the heritability of BMI drops to ∼50% after middle age. The results further indicate that the decline of heritability is due to increasing unique environmental variance, which provides more

  19. Age- and sex-dependent model for estimating radioiodine dose to a normal thyroid

    International Nuclear Information System (INIS)

    This paper describes the derivation of an age- and sex-dependent model of radioiodine dosimetry in the thyroid and the application of the model to estimating the thyroid dose for each of 4215 patients who were exposed to 131I in diagnostic and therapeutic procedures. The model was made to conform to these data requirements by the use of age-specific estimates of the biological half-time of iodine in the thyroid and an age- and sex-dependent representation of the mass of the thyroid. Also, it was assumed that the thyroid burden was maximum 24 hours after administration (the 131I dose is not critically sensitive to this assumption). The metabolic model is of the form A(t) = K[exp(-μ1t) - exp(-μ2t)] (μCi), where μ1 = lambda/sub r/ + lambda/sub i//sup b/ (i = 1, 2), lambda/sub r/ is the radiological decay-rate coefficient, and lambda/sub i//sup b/ are biological removal rate coefficients. The values of lambda/sub i//sup b/ are determined by solving a nonlinear equation that depends on assumptions about the time of maximum uptake and the eventual biological loss rate (through which age dependence enters). The value of K may then be calculated from knowledge of the uptake at a particular time. The dosimetric S-factor (rad/μCi-day) is based on specific absorbed fractions for photons of energy ranging from 0.01 to 4.0 MeV for thyroid masses from 1.29 to 19.6 g; the functional form of the S-factor also involves the thyroid mass explicitly, through which the dependence on age and sex enters. An analysis of sensitivity of the model to uncertainties in the thyroid mass and the biological removal rate for several age groups is reported. The model could prove useful in the dosimetry of very short-lived radioiodines. Tables of age- and sex-dependent coefficients are provided to enable readers to make their own calculations. 12 refs., 5 figs., 4 tabs

  20. Helping others use social media: age stereotypes when estimating learner’s success

    Directory of Open Access Journals (Sweden)

    Harvey J. Ginsburg

    2016-03-01

    Full Text Available Social networking sites (SNS include online products such as Facebook that allow users to build and maintain large interpersonal Internet networks. Older adult users have dramatically increased (Duggan & Smith, 2014. This investigation examined how 212 university undergraduate Facebook users estimated success with helping others use Facebook when learner’s age (20, 40, 60 year olds. and type of acquaintance (friend or kin was manipulated in hypothetical scenarios. In these scenarios, a person is identified as KW, described as being a college student much like the participant. KW has 20, 40 or 60 year-old acquaintances, a friend or a kin at each age, all wanting KW’s help learning about social media. This was the only information provided. Qualities and strengths of these interpersonal relationships were not examined. Results from repeated measures 2x3 ANOVA showed a significant main effect for age, but no effect for acquaintance type. Results showed no significant interaction. Although the age demographic above 50 years is the fastest growing SNS group, results showed possible age stereotyping among youth when they assist older adults learning to use SNS. This age effect may be lessened as older adults become more skillful social media users. These findings are limited because of the sample demographics and a lack of identifying qualities of participants’attributions about the hypothetical friends or relatives. Future research using multiple items per condition might be able to further elucidate how the type of associations between helper and learner, close or distant, positive or negative, would influence outcomes.

  1. The Ages of A-Stars I: Interferometric Observations and Age Estimates for Stars in the Ursa Major Moving Group

    CERN Document Server

    Jones, Jeremy; Boyajian, T; Schaefer, G; Baines, E; Ireland, M; Patience, J; Brummelaar, T ten; McAlister, H; Ridgway, S T; Sturmann, J; Sturmann, L; Turner, N; Farrington, C; Goldfinger, P J

    2015-01-01

    We have observed and spatially resolved a set of seven A-type stars in the nearby Ursa Major moving group with the Classic, CLIMB, and PAVO beam combiners on the CHARA Array. At least four of these stars have large rotational velocities ($v \\sin i$ $\\gtrsim$ 170 $\\mathrm{km~s^{-1}}$) and are expected to be oblate. These interferometric measurements, the stars' observed photometric energy distributions, and $v \\sin i$ values are used to computationally construct model oblate stars from which stellar properties (inclination, rotational velocity, and the radius and effective temperature as a function of latitude, etc.) are determined. The results are compared with MESA stellar evolution models (Paxton et al. 2011, 2013) to determine masses and ages. The value of this new technique is that it enables the estimation of the fundamental properties of rapidly rotating stars without the need to fully image the star. It can thus be applied to stars with sizes comparable to the interferometric resolution limit as oppose...

  2. The use of otolith microstructure to estimate age in adult Atlantic cod Gadus morhua

    DEFF Research Database (Denmark)

    Hüssy, Karin; Hinrichsen, H.H.; Fey, D.P.;

    2010-01-01

    be tightly coupled to the annual cycle in environmental temperature at a depth of 30–60 m, where G. morhua predominantly reside. Between 135 and 200 increments occurred within the different zones, with a non-significant trend towards lower increment numbers and widths with distance from the primary...... primordium of the otolith. Increment formation apparently ceased at temperatures <5–6° C, but growth during the cold months corresponded closely with estimated growth rates. The increment patterns seemed to reflect annual cycles in environmental temperature, and the count of the increment cycles may thus be...... a promising tool for the determination of the true age of Baltic G. morhua....

  3. Postnatal growth, age estimation and development of foraging behaviour in the fulvous fruit bat Rousettus leschenaulti

    Indian Academy of Sciences (India)

    V Elangovan; H Raghuram; E Yuvana Satya Priya; G Marimuthu

    2002-12-01

    This study documents the postnatal growth, age estimation and development of the foraging behaviour of the fulvous fruit bat Rousettus leschenaulti under captive conditions. At birth, the young were naked and pink with closed eyes and folded pinnae. By day four of age, their eyes had opened and the pups began to move. The mean length of forearm in 5-day-old pups was 24.9 mm and body mass was 10.8 g, equivalent to 32.3% and 14.2% of the values from postpartum females. The length of forearm and body mass increased linearly until 45 and 50 days, respectively, and thereafter maintained an apparent stability. The epiphyseal gap of the fourth metacarpalphalangeal joint increased until 15 days, then decreased linearly until 75 days and thereafter closed. Age was estimated quantitatively, based on linear changes observed in the length of the forearm and epiphyseal gap. Pups began to roost separately, but adjacent to their mothers when 30 days old and flew clumsily when they were about 40 days old. After attaining clumsy flight, the young bats made independent foraging attempts feebly by biting and licking small fruit pieces. Young bats were engaged in suckling as well as ingesting fruits when they were about 50 days old. Between 55 and 65 days, they flew well and fed on fruits. At the age of 75 days, the young bats were completely weaned and at two months, their foraging behaviour was similar to that of their mothers. There was no significant difference in the growth pattern of the young maintained in captivity compared with those under natural conditions.

  4. Age estimation in forensic sciences: Application of combined aspartic acid racemization and radiocarbon analysis

    Energy Technology Data Exchange (ETDEWEB)

    Alkass, K; Buchholz, B A; Ohtani, S; Yamamoto, T; Druid, H; Spalding, S L

    2009-11-02

    Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster, since the age at death, birth date and year of death, as well as gender, can guide investigators to the correct identity among a large number of possible matches. Traditional morphological methods used by anthropologists to determine age are often imprecise, whereas chemical analysis of tooth dentin, such as aspartic acid racemization has shown reproducible and more precise results. In this paper we analyze teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbon analysis is that above-ground testing of nuclear weapons during the cold war (1955-1963) caused an extreme increase in global levels of carbon-14 ({sup 14}C) which have been carefully recorded over time. Forty-four teeth from 41 individuals were analyzed using aspartic acid racemization analysis of tooth crown dentin or radiocarbon analysis of enamel and ten of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well (R2=0.66, p < 0.05). Radiocarbon analysis showed an excellent precision with an overall absolute error of 0.6 {+-} 04 years. Aspartic acid racemization also showed a good precision with an overall absolute error of 5.4 {+-} 4.2 years. Whereas radiocarbon analysis gives an estimated year of birth, racemization analysis indicates the chronological age of the individual at the time of death. We show how these methods in combination can also assist in the estimation of date of death of an unidentified victim. This strategy can be of significant assistance in forensic casework involving dead victim identification.

  5. Estimation of mechanical properties of cast stainless steels during thermal aging in LWR systems

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting Charpy- impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common ''lower-bound'' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  6. Estimation of mechanical properties of cast stainless steels during thermal aging in LWR systems

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common predicted lower-bound J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  7. Thermal aging of cast stainless steels in LWR systems: Estimation of mechanical properties

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common ''lower-bound'' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  8. Obtaining appropriate interval estimates for age when multiple indicators are used: evaluation of an ad-hoc procedure.

    Science.gov (United States)

    Fieuws, Steffen; Willems, Guy; Larsen-Tangmose, Sara; Lynnerup, Niels; Boldsen, Jesper; Thevissen, Patrick

    2016-03-01

    When an estimate of age is needed, typically multiple indicators are present as found in skeletal or dental information. There exists a vast literature on approaches to estimate age from such multivariate data. Application of Bayes' rule has been proposed to overcome drawbacks of classical regression models but becomes less trivial as soon as the number of indicators increases. Each of the age indicators can lead to a different point estimate ("the most plausible value for age") and a prediction interval ("the range of possible values"). The major challenge in the combination of multiple indicators is not the calculation of a combined point estimate for age but the construction of an appropriate prediction interval. Ignoring the correlation between the age indicators results in intervals being too small. Boldsen et al. (2002) presented an ad-hoc procedure to construct an approximate confidence interval without the need to model the multivariate correlation structure between the indicators. The aim of the present paper is to bring under attention this pragmatic approach and to evaluate its performance in a practical setting. This is all the more needed since recent publications ignore the need for interval estimation. To illustrate and evaluate the method, Köhler et al. (1995) third molar scores are used to estimate the age in a dataset of 3200 male subjects in the juvenile age range. PMID:26024791

  9. Age Estimation in Living Adults using 3D Volume Rendered CT Images of the Sternal Plastron and Lower Chest.

    Science.gov (United States)

    Oldrini, Guillaume; Harter, Valentin; Witte, Yannick; Martrille, Laurent; Blum, Alain

    2016-01-01

    Age estimation is commonly of interest in a judicial context. In adults, it is less documented than in children. The aim of this study was to evaluate age estimation in adults using CT images of the sternal plastron with volume rendering technique (VRT). The evaluation criteria are derived from known methods used for age estimation and are applicable in living or dead subjects. The VRT images of 456 patients were analyzed. Two radiologists performed age estimation independently from an anterior view of the plastron. Interobserver agreement and correlation coefficients between each reader's classification and real age were calculated. The interobserver agreement was 0.86, and the correlation coefficients between readers classifications and real age classes were 0.60 and 0.65. Spearman correlation coefficients were, respectively, 0.89, 0.67, and 0.71. Analysis of the plastron using VRT allows age estimation in vivo quickly and with results similar than methods such as Iscan, Suchey-Brooks, and radiographs used to estimate the age of death. PMID:27092960

  10. Accuracy of two dental and one skeletal age estimation methods in 6-16 year old Gujarati children

    OpenAIRE

    Patel, Purv S; Anjani Ramachandra Chaudhary; Bhavin B Dudhia; Parul V Bhatia; Naresh C Soni; Yesha V Jani

    2015-01-01

    Introduction: Age estimation is of immense importance not only for personal identification but also for treatment planning in medicine and dentistry. Chronologic age conveys only a rough approximation of the maturational status of a person, hence dental and skeletal ages have been explored as maturity indicators since decades. The tooth maturation provides a valuable indicator of dental age and serves as a better index of the maturation of a child as compared to other maturity indicators. Aim...

  11. Estimation of dental age by Nolla’s method using orthopantomographs among rural free residential school children

    Directory of Open Access Journals (Sweden)

    Nandlal B, Karthikeya Patil, Ravi S

    2014-04-01

    Full Text Available Introduction: Teeth and dental restorations are resistant to destruction by fire and the elements are therefore useful in identification. This permits accurate identification of a missing child or remains. The Rural Residential free school at Suttur houses a large number of inmates and hence dental records are kept for their identification. Objective: Estimation of Age of children. Methods: Orthopantomographs were used to study for estimation of age of children, using a Nolla’s method of dental age estimation. Results: In this study Nolla’s method underestimated the chronological age of the individuals and underestimation of age increased as the chronological age of the individuals increased. Conclusion: Studies involving larger sample size and population specific data needs to be developed.

  12. PREDICTION OF CARCASS TRAITS OF JAPANESE BLACK BULLS AT SEVERAL AGES USING BODY MEASUREMENTS AND ULTRASONIC ESTIMATE OF CARCASS TRAITS

    OpenAIRE

    Sri Rachma, Aprilita Bugiwati

    2008-01-01

    The present research aims to estimate the mathematical equations for predicting ultrasonic estimates of carcass traits at ten months after performance test (about 20 months of age) using body measurements and ultrasonic estimates of carcass traits at earlier stages of performance test of Japanese Black bulls. This research was done at Kagoshima and Miyazaki prefecture Livestock Experimental Stations Japan to collect the ultrasonic estimates of carcass traits and body measurements data of Jap...

  13. Age- and sex-dependent model for estimating radioiodine dose to a normal thyroid

    International Nuclear Information System (INIS)

    This paper describes the derivation of an age- and sex-dependent model of radioiodine dosimetry in the thyroid and the application of the model to estimating the thyroid dose for each of 4215 patients who were exposed to 131I in diagnostic and therapeutic procedures. In most cases, the available data consisted of the patient's age at the time of administration, the patient's sex, the quantity of activity administered, the clinically-determined uptake of radioiodine by the thyroid, and the time after administration at which the uptake was determined. The metabolic model is of the form A(t) = K[exp(-μ1t) -exp(-μ2t)] (μCi), where μ1 = λ/sub r/ - λ/sub i//sup b/ (i = 1, 2), λ/sub r/ is the radiological decay-rate coefficient, and λ/sub i//sup b/ are biological removal rate coefficients. The values of λ/sub i//sup b/ are determined by solving a nonlinear equation that depends on assumptions about the time or maximum uptake an the eventual biological loss rate (through which age dependence enters). The value of K may then be calculated from knowledge of the uptakes at a particular time. The dosimetric S-factor (rad/μCi-day) is based on specific absorbed fractions for photons of energy ranging from 0.01 to 4.0 MeV for thyroid masses from 1.29 to 19.6 g; the functional form of the S-factor also involves the thyroid mass explicitly, through which the dependence on age and sex enters. An analysis of sensitivity of the model to uncertainties in the thyroid mass and the biological removal rate for several age groups is reported. 12 references, 5 figures, 5 tables

  14. Dental age estimation and different predictive ability of various tooth types in the Czech population: data mining methods.

    Science.gov (United States)

    Velemínská, Jana; Pilný, Ales; Cepek, Miroslav; Kot'ová, Magdaléna; Kubelková, Radka

    2013-01-01

    Dental development is frequently used to estimate age in many anthropological specializations. The aim of this study was to extract an accurate predictive age system for the Czech population and to discover any different predictive ability of various tooth types and their ontogenetic stability during infancy and adolescence. A cross-sectional panoramic X-ray study was based on developmental stages assessment of mandibular teeth (Moorrees et al. 1963) using 1393 individuals aged from 3 to 17 years. Data mining methods were used for dental age estimation. These are based on nonlinear relationships between the predicted age and data sets. Compared with other tested predictive models, the GAME method predicted age with the highest accuracy. Age-interval estimations between the 10th and 90th percentiles ranged from -1.06 to +1.01 years in girls and from -1.13 to +1.20 in boys. Accuracy was expressed by RMS error, which is the average deviation between estimated and chronological age. The predictive value of individual teeth changed during the investigated period from 3 to 17 years. When we evaluated the whole period, the second molars exhibited the best predictive ability. When evaluating partial age periods, we found that the accuracy of biological age prediction declines with increasing age (from 0.52 to 1.20 years in girls and from 0.62 to 1.22 years in boys) and that the predictive importance of tooth types changes, depending on variability and the number of developmental stages in the age interval. GAME is a promising tool for age-interval estimation studies as they can provide reliable predictive models. PMID:24466642

  15. Estimation of age based on tooth cementum annulations: A comparative study using light, polarized, and phase contrast microscopy

    Science.gov (United States)

    Kaur, Prabhpreet; Astekar, Madhusudan; Singh, Jappreet; Arora, Karandeep Singh; Bhalla, Gagandeep

    2015-01-01

    Context: The identification of living or deceased persons using unique traits and characteristics of the teeth and jaws is a cornerstone of forensic science. Teeth have been used to estimate age both in the young and old, as well as in the living and dead. Gradual structural changes in teeth throughout life are the basis for age estimation. Tooth cementum annulation (TCA) is a microscopic method for the determination of an individual's age based on the analysis of incremental lines of cementum. Aim: To compare ages estimated using incremental lines of cementum as visualized by bright field microscopy, polarized microscopy, and phase contrast microscopy with the actual age of subject and to determine accuracy and feasibility of the method used. Materials and Methods: Cementum annulations of 60 permanent teeth were analyzed after longitudinal ground sections were made in the mesiodistal plane. The incremental lines were counted manually using a light, polarized and phase contrast microscopy. Ages were estimated and then compared with the actual age of individual. Statistical Analysis: Analysis of variance (ANOVA), Student's t-test, the Pearson product-moment corre (PPMCC) and regression analysis were performed. Results: PPMCC value r = 0.347, 0.542 and 0.989 were obtained using light, polarized and phase contrast microscopy methods respectively. Conclusion: It was concluded that incremental lines of cementum were most clearly visible under a phase contrast microscope, followed by a polarized microscope, and then a light microscope when used for age estimation. PMID:26816462

  16. Old stellar population synthesis: new age and mass estimates for Mayall Ⅱ = G1

    Institute of Scientific and Technical Information of China (English)

    Jun Ma; Richard de Grijs; Zhou Fan; Soo-Chang Rey; Zhen-Yu Wu; Xu Zhou; Jiang-Hua Wu; Zhao-Ji Jiang; Jian-Sheng Chen; Kyungsook Lee; Sangmo Tony Sohn

    2009-01-01

    Mayall Ⅱ = G1 is one of the most luminous globular clusters (GCs) in M31. Here, we determine its age and mass by comparing multicolor photometry with theo-retical stellar population synthesis models. Based on far- and near-ultraviolet GALEX photometry, broad-band UBV RI, and infrared JHK8 2MASS data, we construct the most extensive spectral energy distribution of G1 to date, spanning the wavelength range from 1538 to 20000A. A quantitative comparison with a variety of simple stellar pop-ulation (SSP) models yields a mean age which is consistent with G1 being among the oldest building blocks of M31 and having formed within ~1.7Gyr after the Big Bang. Irrespective of the SSP model or stellar initial mass function adopted, the resulting mass estimates (of order 107M⊙) indicate that G1 is one of the most massive GCs in the Local Group. However, we speculate that the cluster's exceptionally high mass suggests that it may not be a genuine GC. Our results also suggest that G1 may contain, on average, (1.65±0.63) × 102L⊙ far-ultraviolet-bright, hot, extreme horizontal-branch stars, depend-ing on the adopted SSP model. In addition, we demonstrate that extensive multi-passband photometry coupled with SSP analysis enables one to obtain age estimates for old SSPs that have similar accuracies as those from integrated spectroscopy or resolved stellar pho-tometry, provided that some of the free parameters can be constrained independently.

  17. Improving artificial forest biomass estimates using afforestation age information from time series Landsat stacks.

    Science.gov (United States)

    Liu, Liangyun; Peng, Dailiang; Wang, Zhihui; Hu, Yong

    2014-11-01

    China maintains the largest artificial forest area in the world. Studying the dynamic variation of forest biomass and carbon stock is important to the sustainable use of forest resources and understanding of the artificial forest carbon budget in China. In this study, we investigated the potential of Landsat time series stacks for aboveground biomass (AGB) estimation in Yulin District, a key region of the Three-North Shelter region of China. Firstly, the afforestation age was successfully retrieved from the Landsat time series stacks in the last 40 years (from 1974 to 2013) and shown to be consistent with the surveyed tree ages, with a root-mean-square error (RMSE) value of 4.32 years and a determination coefficient (R (2)) of 0.824. Then, the AGB regression models were successfully developed by integrating vegetation indices and tree age. The simple ratio vegetation index (SR) is the best candidate of the commonly used vegetation indices for estimating forest AGB, and the forest AGB model was significantly improved using the combination of SR and tree age, with R (2) values from 0.50 to 0.727. Finally, the forest AGB images were mapped at eight epochs from 1985 to 2013 using SR and afforestation age. The total forest AGB in seven counties of Yulin District increased by 20.8 G kg, from 5.8 G kg in 1986 to 26.6 G kg in 2013, a total increase of 360 %. For the persistent forest area since 1974, the forest AGB density increased from 15.72 t/ha in 1986 to 44.53 t/ha in 2013, with an annual rate of about 0.98 t/ha. For the artificial forest planted after 1974, the AGB density increased about 1.03 t/ha a year from 1974 to 2013. The results present a noticeable carbon increment for the planted artificial forest in Yulin District over the last four decades. PMID:25034235

  18. Simple mathematical formulae for estimation of median values of fetal biometry at each gestational age

    Science.gov (United States)

    Choi, Hwa Young; Kim, Jeong Ha; Park, Jee Yoon; Jung, Eun Young; No, Jae Hong; Oh, Kyung Joon

    2016-01-01

    Objective The aim of this study was to propose simple mathematical formulae to estimate median values of fetal biometry including biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) at each gestational age (GA) easily without looking up the previously established reference values. Methods Simple mathematical formulae to estimate median values of fetal biometric values at each gestational week were inferred. To validate these formulae, three different linear equations were derived from previously reported reference values of median BPD, AC and FL using regression analysis at each gestational week. Finally, calculated data through the inferred formula were compared to retrospectively collected data (observed data). Results The equation revealing the relationship between BPD and GA was: median BPD (cm)=GA (wk)/4. Using this simple mathematical formula, the absolute percentage error between observed data and calculated data ranged from 0.12% to 7.50%. The equation between AC and GA was: median AC (cm)=GA (wk)-5. Through this formula, the absolute percentage error was analyzed same as above and it ranged from 0.30% to 4.76%. Lastly the derived formula between FL and GA was: median FL (cm)=GA (wk)/5 and the absolute percentage error ranged from 4.52% to 16.75%. Conclusion The three simple formulae suggested in our study showed a significantly easy way to estimate the median values of fetal biometry at each gestational week with good reliability. PMID:27004198

  19. Estimation of glandular content rate and statistical analysis of the influence of age group and compressed breast thickness on the estimated value

    International Nuclear Information System (INIS)

    Because the glandular content rate is an important factor in evaluating breast cancer detection and average glandular dose, it is important in mammography research to estimate and analyze this rate. The purpose of this study was to obtain a formula for statistical estimation of the glandular content rate, to clarify statistically the influence of age group and compressed breast thickness (CBT) on estimating the glandular content rate, and to show statistically the general relation between glandular content rate and the factors of age and CBT. The subjects were 740 Japanese women aged 20-91 years (mean±SD: 48.3±12.8 years) who had undergone mammography. In our study, the glandular content rate was statistically estimated from age group, mAs-value, and CBT when subjects underwent mammography, from a phantom simulation, and from MR images of the breast. In addition, multivariate analysis was carried to examine statistically the influence of age group and CBT on glandular content rate. The mean glandular content rate as estimated by age group was as follows: 35.6% for those in their 20s, 33.4% in the 30s, 27.5% in the 40s, 23.8% in the 50s, and 21.8% in those 60 and over. The rate for the subjects as a whole was 27.1%. This study indicated that overestimation occurred if the estimated value of the glandular content rate was not corrected in the 3D-measurement by MRI. In addition, this study showed that the statistical influence on glandular content rate was significantly larger for CBT than age. (author)

  20. Estimation of dental age by Nolla’s method using orthopantomographs among rural free residential school children

    OpenAIRE

    Nandlal B, Karthikeya Patil, Ravi S

    2014-01-01

    Introduction: Teeth and dental restorations are resistant to destruction by fire and the elements are therefore useful in identification. This permits accurate identification of a missing child or remains. The Rural Residential free school at Suttur houses a large number of inmates and hence dental records are kept for their identification. Objective: Estimation of Age of children. Methods: Orthopantomographs were used to study for estimation of age of children, using a Nolla’s method of den...

  1. Estimating true age-dependence in survival when only adults can be observed: an example with Black-legged Kittiwakes

    Directory of Open Access Journals (Sweden)

    Frederiksen, M.

    2004-06-01

    Full Text Available In long-lived birds, pre-breeders are often difficult or impossible to observe, and even though a proportion of marked adults may be of known age, the estimation of age-specific survival is complicated by the absence of observations during the first years of life. New developments in MARK now allow use of an updated individual covariate. We used this powerful approach to model age-dependence in survival of Black-legged Kittiwakes (Rissa tridactyla at a North Sea colony. Although only 69 marked breeders were of known age, there was strong evidence for a quadratic relationship between true age and survival. We believe that this simple but powerful approach could be implemented for many species and could provide improved estimates of how survival changes with age, a central theme in life history theory.

  2. Forensic age estimation from the clavicle using 1.0 T MRI—Preliminary results

    DEFF Research Database (Denmark)

    Larsen, Sara Tangmose; Jensen, Karl Erik; Villa, Chiara;

    2014-01-01

    of "incomplete fusion" (≤ stage 3 on both sides) against "fused" (at least one stage 4), agreement rate rose to moderate (K=0.414) for living subjects. Despite the low agreement rate, no subject younger than 18 years was assessed as having "fused" clavicles. CONCLUSION: At lower image resolution, a 2......OBJECTIVES: As forensic age estimations in the living are performed without medical indication, there is a need for the development of non-ionizing methods. This study investigates the use of 1.0T MRI to visualize the ossification status of the medial end of the clavicle. MATERIAL AND METHODS: T2...... weighted 3D images were collected from a 1.0T MR system. We prospectively scanned 102 subjects, 47 autopsy cases and 55 living volunteers (12-33 years). Images were scored in blind trials by three observers using a 4-stage system. Observers differed by level of training and radiological expertise. RESULTS...

  3. Normative perceptual estimates for 91 healthy subjects age 60–75: impact of age, education, employment, physical exercise, alcohol, and video gaming

    OpenAIRE

    Wilms, Inge L.; Nielsen, Simon

    2014-01-01

    Visual perception serves as the basis for much of the higher level cognitive processing as well as human activity in general. Here we present normative estimates for the following components of visual perception: the visual perceptual threshold, the visual short-term memory (VSTM) capacity and the visual perceptual encoding/decoding speed (processing speed) of VSTM based on an assessment of 91 healthy subjects aged 60–75. The estimates were modeled from input from a whole-report assessment ba...

  4. Estimation of Charpy notch toughness for thermal aging specimens of cast duplex stainless steel using thermalelectric power measurement

    International Nuclear Information System (INIS)

    The material properties of cast duplex stainless steel, which is used for main coolant pipes of PWR (pressurized water reactor) type nuclear power plants, change due to thermal aging. Therefore it is advisable to evaluate these changes of material properties non-destructively for maintenance of the plant component. In order to establish a non-destructive evaluation procedure for the degree of thermal aging of cast duplex stainless steel, thermoelectric power (TEP) measurements were carried out with a newly made TEP meter for thermal aging specimens, with different ferrite contents, aging temperatures and aging periods. Then the relationship between TEP and notch toughness obtained by Charpy impact test was investigated. As the results: (1) TEP increases due to thermal aging. The higher ferrite content, the higher TEP. The higher aging temperature, the more rapidly TEP increases. (2) Because of the decrease of Charpy notch toughness and the increase of TEP due to the fluctuation of Cr concentration caused by the phase separation of the ferrite phase, TEP increases by thermal aging as the Charpy notch toughness decreases. (3) Regardless of the aging temperature, the specimens with the same ferrite content have the same relationship between Charpy notch toughness and TEP. (4) It is possible to estimate Charpy notch toughness with an error of 100 J/cm2 by TEP in the beginning of aging. Therefore, it can be concluded that we can estimate Charpy notch toughness for cast duplex stainless steel by TEP depending on the ferrite content regardless of the aging temperature. (author)

  5. Estimate of multiplicative and additive age adjustment factors for milk yield for the Mediterranean Italian Buffalo Breed

    Directory of Open Access Journals (Sweden)

    E. Parlato

    2010-02-01

    Full Text Available This study was carried out to estimate multiplicative and additive age adjustment factors for milk yield for the Mediterranean Italian Buffalo Breed for a mature age base (55 months, parity 2 with a mixed model procedure. Fixed effects of age-parity classes and random effects of contemporary group, genetic and permanent environmental effects of cows were included in the model. Two data sets were formed: Data Set I consisted of 83,810 lactation records and was used to develop the age factors. Data Set II consisted of 115,242 lactation records and was used for validation of the age factors estimated from Data Set I. Additive and multiplicative factors followed the same trend within the three parities (parity 1, parity 2, and parity ≥ 3. Averages of milk yield by age class for Data Set II pre-adjusted with multiplicative and additive factors from Data Set I were similar and tended to follow a straight line as expected. However, multiplicative factors might be preferred to additive factors because they would be affected less by an increase of the average milk yield due to selection or management. Age factors were smoothed to reduce differences among factors for similar age-parity classes. The smoothed age factors showed only slight differences among averages for similar age-parity classes, which suggests that the smoothed age factors may be more appropriate than the original factors.

  6. Contribution of Quantitative Methods of Estimating Mortality Dynamics to Explaining Mechanisms of Aging.

    Science.gov (United States)

    Shilovsky, G A; Putyatina, T S; Markov, A V; Skulachev, V P

    2015-12-01

    Accumulation of various types of unrepaired damage of the genome because of increasing production of reactive oxygen species and decreasing efficiency of the antioxidant defense system and repair systems can cause age-related diseases and emergence of phenotypic signs of senescence. This should lead to increasing vulnerability and to mortality monotonously increasing with age independently of the position of the species on the evolutionary tree. In this light, the survival, mortality, and fertility curves for 45 animal and plant species and one alga published by the Max Planck Institute for Demographic Research (Germany/Denmark) are of special interest (Jones, O. R., et al. (2014) Nature, 505, 169-173). We divided all species treated in that study into four groups according to the ratio of mortality at the terminal age (which corresponds to 5% survival) and average mortality during the entire studied period. For animals of group IV (long-lived and senescent), including humans, the Jones method makes it possible to trace mortality during the entire life cycle. The same applies to short-lived animals (e.g. nematodes or the tundra vole), whether they display the Gompertz type of senescence or not. However, in long-lived species with a less pronounced increase in mortality with age (e.g. the freshwater crocodile, hermit crab, or Scots pine), as well as in animals of average lifespan that reach the terminal age earlier than they could have enough time to become senescent, the Jones method is capable of characterizing only a small part of the life cycle and does not allow judging how senescence manifests itself at late stages of the life cycle. Thus, it is known that old trees display signs of biological senescence rather clearly; although Jones et al. consider them non-senescent organisms because less than 5% of sexually mature individuals survive to display the first manifestations of these characters. We have concluded that the classification proposed by Jones et al

  7. Age difference in deposition of plutonium in organs of rats and the estimation of distribution in humans

    International Nuclear Information System (INIS)

    Differences in plutonium distribution in various organs, particularly the bones, of rats injected at different ages were examined in order to aid in estimating plutonium distribution in humans. Comparisons were made between rats and humans based on the bone histomorphometric and mineral density data. Male and female rats of three ages (3, 12, and 24 months old), respectively, received an injection of plutonium nitrate by two dose modalities; a fixed amount of plutonium without regard to age, sex, or body weight; per g of body weight. The rats were killed 2 weeks after the injection of plutonium. The amounts of plutonium deposited in the organs varied without regard to the body or organ weight; those in the skeleton increased from 3 to 12 months, reaching a peak at 12 months, but then decreased, along with the age-related changes in the bone surface, volume, and mineral density. Those in the liver, spleen and kidney decreased despite the body weight gain with age in both sexes. Age-related differences in the deposition of plutonium in humans were estimated based on the bone data characteristics obtained from the histomorphometry and bone mineral density for corresponding of ages between rats and humans. The results indicate that age is the most important factor in estimating the distribution of plutonium deposition in the early period after plutonium exposure, and that body or organ weight is not always a useful indicator, particularly in the aged. (author)

  8. Radii, masses, and ages of 18 bright stars using interferometry. And new estimations of exoplanetary parameters

    CERN Document Server

    Ligi, Roxanne; Mourard, Denis; Crida, Aurélien; Lagrange, Anne-Marie; Nardetto, Nicolas; Perraut, Karine; Schultheis, Mathias

    2015-01-01

    Accurate stellar parameters are needed in numerous domains of astrophysics. The position of stars on the H-R diagram is an important indication of their structure and evolution, and it helps improve stellar models. Furthermore, the age and mass of stars hosting planets are required elements for studying exoplanetary systems. We aim at determining accurate parameters of a set of 18 bright exoplanet host and potential host stars from interferometric measurements, photometry, and stellar models. Using the VEGA/CHARA interferometer, we measured the angular diameters of 18 stars, ten of which host exoplanets. We combined them with their distances to estimate their radii. We used photometry to derive their bolometric flux and, then, their effective temperature and luminosity to place them on the H-R diagram. We then used the PARSEC models to derive their best fit ages and masses, with error bars derived from MC calculations. Our interferometric measurements lead to an average of 1.9% uncertainty on angular diameter...

  9. Improved age estimates for key Late Quaternary European tephra horizons in the RESET lattice

    Science.gov (United States)

    Bronk Ramsey, Christopher; Albert, Paul G.; Blockley, Simon P. E.; Hardiman, Mark; Housley, Rupert A.; Lane, Christine S.; Lee, Sharen; Matthews, Ian P.; Smith, Victoria C.; Lowe, John J.

    2015-06-01

    The research project 'Response of Humans to Abrupt Environmental Transitions' (RESET) used tephra layers to tie together and synchronise the chronologies of stratigraphic records at archaeological and environmental sites. With the increasing importance of tephra as chronological markers in sedimentary sequences, both in this project and more generally, comes a requirement to have good estimates for the absolute age of these volcanic horizons. This paper summarises the chronology of the key tephra in the RESET tephra lattice in the time range 10-60 ka BP, from the existing literature, from papers produced as part of the RESET project, and reanalysis conducted for this paper. The paper outlines the chronological approach taken to the dating of tephra within the RESET project, and the basis for further work, as part of the INTIMATE (INTegrating Ice core MArine and TErrestrial records) initiative. For each of the tephra layers in the lattice, the existing literature is discussed and, where relevant date estimates updated using the latest radiocarbon calibration curves (IntCal13 and Marine13) and methods. Maps show the approximate extent of tephra finds, giving a visual indication of the coverage of the lattice in different time-periods.

  10. Method of estimation of technical preparedness level of baseballs aged 12-14 years

    Directory of Open Access Journals (Sweden)

    Agapov D.V.

    2013-02-01

    Full Text Available The method of estimation of level of technical preparedness is developed for young baseballs. The scale of estimation of level of technical preparedness of sportsmen is formed on the method of sigmantion rejections. In an experiment took part 100 boys in age 12-14 years. The test of the program «Aquafina MLB Pitch was utillized, Hit & Run». The maximally attained indexes are certain on separate baseball skills. The level of development of technical preparedness is exposed after an experiment on the program: a test of «pitch» is 450 marks, a test of «hit» is 402 marks, a test of «run» is a 361 mark, indexes of general marks are 1043 marks. The comparative analysis of level of technical preparedness of baseballs of control and experimental groups is conducted. Authenticity of distinctions is proved between control and experimental groups on the followings criteria of technical preparedness: throw, blow at run.

  11. Should total landings be used to correct estimated catch in numbers or mean-weight-at-age?

    DEFF Research Database (Denmark)

    Lewy, Peter; Lassen, H.

    1997-01-01

    discrepancies some countries correct catch in numbers while others correct mean weight-at-age by a common factor, the ratio between landing and SOP. The paper shows that for three sampling schemes the SOP corrections are statistically incorrect and should not be made since the SOP is an unbiased estimate...... of the total landings. Calculation of the bias of estimated catch in numbers and mean weight-at-age shows that SOP corrections of either of these estimates may increase the bias. Furthermore, for five demersal and one pelagic North Sea species it is shown that SOP discrepancies greater than 2% from...

  12. Self-estimation of Body Fat is More Accurate in College-age Males Compared to Females

    OpenAIRE

    HANCOCK, HALLEY L.; Jung, Alan P.; Petrella, John K.

    2012-01-01

    The objective was to determine the effect of gender on the ability to accurately estimate one’s own body fat percentage. Fifty-five college-age males and 99 college-age females participated. Participants estimated their own body fat percent before having their body composition measured using a BOD POD. Participants also completed a modified Social Physique Anxiety Scale (SPAS). Estimated body fat was significantly lower compared to measured body fat percent in females (26.8±5.6% vs. 30.2±7.0%...

  13. Should total landings be used to correct estimated catch in numbers or mean-weight-at-age?

    DEFF Research Database (Denmark)

    Lewy, Peter; Lassen, H.

    1997-01-01

    Many ICES fish stock assessment working groups have practised Sum Of Products, SOP, correction. This correction stems from a comparison of total weights of the known landings and the SOP over age of catch in number and mean weight-at-age, which ideally should be identical. In case of SOP...... discrepancies some countries correct catch in numbers while others correct mean weight-at-age by a common factor, the ratio between landing and SOP. The paper shows that for three sampling schemes the SOP corrections are statistically incorrect and should not be made since the SOP is an unbiased estimate of the...... total landings. Calculation of the bias of estimated catch in numbers and mean weight-at-age shows that SOP corrections of either of these estimates may increase the bias. Furthermore, for five demersal and one pelagic North Sea species it is shown that SOP discrepancies greater than 2% from the...

  14. Validity of demirjian and nolla methods for dental age estimation for Northeastern Turkish children aged 5–16 years old

    OpenAIRE

    Nur, Bilge; Kusgoz, Adem; Bayram, Mehmet; Celikoglu, Mevlut; Nur, Metin; KAYIPMAZ, Saadettin; Yildirim, Sina

    2012-01-01

    Objective: To evaluate the applicability of Demirjian and Nolla methods for northeastern Turkish population. Material and Method: A retrospective study was performed on panoramic radiographs of 673 subjects aged 5–15.9 years. The mean dental age (DA) according to the Demirjian and Nolla methods were compared to the mean chronological age (CA). Results: The mean CA of the study sample was 10.37±2.90 and 10.03±2.81 years for females and males, respectively. Using the Demirjian method, the mean ...

  15. Age and growth estimation of bigeye tuna, Thunnus obesus (Teleostei: Scombridae in the southwestern Atlantic

    Directory of Open Access Journals (Sweden)

    Paulo Duarte-Neto

    2012-01-01

    Full Text Available The purpose of the current study was to supply the first information on age and growth for Thunnus obesus caught in the equatorial south-western Atlantic using dorsal spines, an approach that has been successfully employed for ageing tuna species. The study was conducted using a multi-model inference based on information theory for back-calculated and observed length-at-age data. Uncertainty associated with the parameter estimation was verified and results were compared to other accounts on the species, considering both the statistical and methodological contexts. Samples were collected in Natal city (Rio Grande do Norte State, Brazil from February 1999 to January 2000, of tuna vessels and from surveys, aimed at providing information on the Brazilian Exclusive Economic Zone (EEZ in the area around São Pedro and São Paulo Archipelago. Validation using marginal increment indicated that one ring is deposited per year. Mean length-at-age ranged of 54.3 to 177.5 cm (fork length for ages 1 to 9 years. Von Bertalanffy, Richards, and Gompertz models were considered suitable for the bigeye tuna. Hence, the model-averaged asymptotic length ¯L∞ was estimated. The averaged model generated in the present study by back-calculation was considered appropriate for describing the growth of T. obesus.A proposta do presente estudo foi fornecer a primeira informação sobre idade e crescimento de Thunnus obesus, capturado no Atlântico sudoeste equatorial usando espinhos dorsais, uma abordagem que tem sido utilizada com sucesso na determinação de idade de espécies de atuns. O estudo foi conduzido usando uma inferência de multi-modelos baseada na teoria de informação avaliada para dados de comprimento por idade retrocalculados e observados. Incertezas associadas aos parâmetros foram verificadas e os resultados foram comparados aos de outros estudos realizados para esta espécie, considerando os contextos estatísticos e metodológicos. As amostras foram

  16. Incremental lines in root cementum of human teeth: An approach to their role in age estimation using polarizing microscopy

    Directory of Open Access Journals (Sweden)

    Aggarwal Pooja

    2008-01-01

    Full Text Available Age estimation is an important factor in the identification of an individual in forensic science. The hard tissues of the human dentition are able to resist decay and degradation long after other tissues are lost. This resistance has made teeth useful indicators for age calculation. Recent research indicates that tooth cementum annulations (TCA may be used more reliably than any other morphological or histological traits of the adult skeleton for age estimation. The purpose of this study was to examine the correlation between age and the number of incremental lines in human dental cementum and to ascertain the best method of studying cementum with respect to different forms of microscopy. Thirty nonrestorable teeth were extracted from 20 people, and longitudinal ground section of each tooth was prepared. Photomicrographs of the area at the junction of apical and middle third of the root under light and polarized microscope were taken. The cementum was composed of multiple light and dark bands that were counted on the photomicrograph with the help of image analysis software and added to the average eruption time of individual tooth. The predicted age of the individual was thus obtained. Results showed a significant correlation between the predicted age and actual chronological age of the individual. These data indicate that quantitation of cementum annuli is a moderately reliable means for age estimation in humans and polarizing microscopy is a better means of visualizing incremental lines of cementum compared to light microscopy.

  17. A sequential Bayesian approach for the estimation of the age-depth relationship of Dome Fuji ice core

    Science.gov (United States)

    Nakano, S.; Suzuki, K.; Kawamura, K.; Parrenin, F.; Higuchi, T.

    2015-06-01

    A technique for estimating the age-depth relationship in an ice core and evaluating its uncertainty is presented. The age-depth relationship is mainly determined by the accumulation of snow at the site of the ice core and the thinning process due to the horizontal stretching and vertical compression of ice layers. However, since neither the accumulation process nor the thinning process are fully understood, it is essential to incorporate observational information into a model that describes the accumulation and thinning processes. In the proposed technique, the age as a function of depth is estimated from age markers and δ18O data. The estimation is achieved using the particle Markov chain Monte Carlo (PMCMC) method, in which the sequential Monte Carlo (SMC) method is combined with the Markov chain Monte Carlo method. In this hybrid method, the posterior distributions for the parameters in the models for the accumulation and thinning processes are computed using the Metropolis method, in which the likelihood is obtained with the SMC method. Meanwhile, the posterior distribution for the age as a function of depth is obtained by collecting the samples generated by the SMC method with Metropolis iterations. The use of this PMCMC method enables us to estimate the age-depth relationship without assuming either linearity or Gaussianity. The performance of the proposed technique is demonstrated by applying it to ice core data from Dome Fuji in Antarctica.

  18. Ages at a Crime Scene: Simultaneous Estimation of the Time since Deposition and Age of Its Originator.

    Science.gov (United States)

    Agudelo, Juliana; Halámková, Lenka; Brunelle, Erica; Rodrigues, Roselyn; Huynh, Crystal; Halámek, Jan

    2016-06-21

    Blood is a major contributor of evidence in investigations involving violent crimes because of the unique composition of proteins and low molecular weight compounds present in the circulatory system, which often serve as biomarkers in clinical diagnostics. It was recently shown that biomarkers present in blood can also identify characteristics of the originator, such as ethnicity and biological sex. A biocatalytic assay for on-site forensic investigations was developed to simultaneously identify the age range of the blood sample originator and the time since deposition (TSD) of the blood spot. For these two characteristics to be identified, the levels of alkaline phosphatase (ALP), a marker commonly used in clinical diagnostics corresponding to old and young originators, were monitored after deposition for up to 48 h to mimic a crime scene setting. ALP was chosen as the biomarker due to its age-dependent nature. The biocatalytic assay was used to determine the age range of the originator using human serum samples. By means of statistical tools for evaluation and the physiological levels of ALP in healthy people, the applicability of this assay in forensic science was shown for the simultaneous determination of the age of the originator and the TSD of the blood spot. The stability of ALP in serum allows for the differentiation between old and young originators up to 2 days after the sample was left under mimicked crime scene conditions. PMID:27212711

  19. Spectral Energy Distributions and Age Estimates of 172 Globular Clusters in M31

    CERN Document Server

    Jiang, L; Zhou, X; Chen, J; Wu, H; Jiang, Z; Jiang, Linhua; Ma, Jun; Zhou, Xu; Chen, Jiansheng; Wu, Hong; Jiang, Zhaoji

    2003-01-01

    In this paper we present CCD multicolor photometry for 172 globular clusters (GCs), taken from the Bologna catalog (Battistini et al. 1987), in the nearby spiral galaxy M31. The observations were carried out by using the National Astronomical Observatories 60/90 cm Schmidt Telescope in 13 intermediate-band filters, which covered a range of wavelength from 3800 to 10000A. This provides a multicolor map of M31 in pixels of 1.7"*1.7". By aperture photometry, we obtain the spectral energy distributions (SEDs) for these GCs. Using the relationship between the BATC intermediate-band system used for the observations and the UBVRI broad-band system, the magnitudes in the B and V bands are derived. The computed V and B-V are in agreement with the values given by Battistini et al. (1987) and Barmby et al. (2000). Finally, by comparing the photometry of each GC with theoretical stellar population synthesis models, we estimate ages of the sample GCs for different metallicities. The results show that nearly all our sample...

  20. Estimation of Gestational Age According to Crown-Rump Length in Nepalese Population: A Comparison with Previously Published Nomograms

    Directory of Open Access Journals (Sweden)

    B. Raj Joshi

    2009-11-01

    Full Text Available Background/Objective: This study was performed to construct an institution specific crown-rump length (CRL nomogram and to compare its ability to predict gestational age with previously published nomograms. "nPatients and Methods: A regression model was developed for estimation of gestational age using CRL measurements of 123 singleton fetuses in the Nepalese population. Measurements were obtained by placing the calipers of the ultrasound machine from the crown to the rump. The appropriateness of previously established CRL nomograms for predicting the gestational age was assessed in the Nepalese population to determine comparability between nomograms. "nResults: CRL corresponds to Robinson's nomogram up to 9 weeks of gestational age. There is a deficiency of 2mm at 10 weeks, 5 mm at 11 weeks and 8 mm at 12 weeks. "nConclusion: CRL measurements are used as a reliable method for estimation of the gestational age as well as a baseline for comparing gestational ages later. CRL corresponds to Robinson's nomogram up to 9 weeks gestational age. There is a deficiency of 2-8 mm from 10-12 weeks gestational age. Difference with the established nomograms may be due to ethnic differences of the fetal development. After 12 weeks, CRL measurement is unreliable due to flexion of the fetus.

  1. Age estimation from pulp/tooth area ratio in maxillary incisors among Egyptians using dental radiographic images.

    Science.gov (United States)

    Zaher, Jaklin Fekri; Fawzy, Irene Atef; Habib, Sahar Refaat; Ali, Magdy Mohamed

    2011-02-01

    Age estimation from dental radiographs is a non-destructive, simple method to obtain information. The aim of this study was to determine the reliability of age estimation from Egyptians' incisors radiographs. 144 periapical radiographs of maxillary (central & lateral) incisors (both sexes) aged 12-60 were used. Digital camera was used to image the radiographs. Images were computed and pulp/tooth area ratios were determined by AutoCAD Program. Data were subjected to correlation and regression analysis which showed statistically significant correlation (r = 0.23 &P = 0.006 for maxillary central incisors and r = -0.2 &P = 0.05 for maxillary lateral incisors) between age and pulp tooth area ratio. Linear regression equations were determined separately for both central and lateral incisors along with the corresponding Standard Error of Estimate, which ranged from 1.2 to 5.08 years. Consequently, it was concluded that pulp/tooth area ratios of incisors are reliable for estimation of age among Egyptians in forensic work. PMID:21315299

  2. The accuracy of estimating chronological age from Demirjian and Nolla methods in a Portuguese and Spanish sample

    OpenAIRE

    Tomás, Luís F; Mónico, Lisete SM; Tomás, Inmaculada; Varela-Patiño, Purificación; Martin-Biedma, Benjamín

    2014-01-01

    Background Age determination has great importance in many clinical decisions, being commonly used in odontopediatrics, orthodontics, pediatrics, and forensic medicine. The Nolla and Demirjian et al. methods have been used for these purposes. However, estimating chronological age by means of the dental mineralization stage is not a straightforward analysis, and it is fundamental to test the validity of these methods and their applicability to populations. In this article we intend to compare t...

  3. Estimation of Gestational Age According to Crown-Rump Length in Nepalese Population: A Comparison with Previously Published Nomograms

    OpenAIRE

    B. Raj Joshi

    2009-01-01

    Background/Objective: This study was performed to construct an institution specific crown-rump length (CRL) nomogram and to compare its ability to predict gestational age with previously published nomograms. "nPatients and Methods: A regression model was developed for estimation of gestational age using CRL measurements of 123 singleton fetuses in the Nepalese population. Measurements were obtained by placing the calipers of the ultrasound machine from the crown to the rump. The appropri...

  4. Pulp/tooth ratio of mandibular first and second molars on panoramic radiographs: An aid for forensic age estimation

    Science.gov (United States)

    Shah, Palak H.; Venkatesh, Rashmi

    2016-01-01

    Objective: To determine and compare the accuracy of pulp/tooth ratio method in mandibular first and second molar teeth in forensic age estimation. Materials and Methods: A total 300 panoramic radiographs of the Gujarati population (187 males and 113 females) were studied. The measurements of Pulp Chamber Height (PCH) and Crown Root Trunk Height (CRTH) were performed on the mandibular first and second molar teeth. The acquired data was subjected to correlation and regression. Results: The pulp chamber crown root trunk height ratios (PCTHR) of both the first (r = −0.609) and second molars (r = −0.422) were significantly correlated with the age of the individual. Individual regression formulae were derived for both the teeth which were then used separately to calculate the age. The standard errors estimate (SEE) for the first and second molars were 8.84 years and 10.11 years, respectively. There was no statistically significant difference between chronological and calculated age by both the teeth (P = 1.000). Conclusion: The mandibular first and second molar is a potential tool for age estimation in forensic dentistry. The pulp/tooth ratio of both the teeth is a useful method for forensic age prediction with reasonable accuracy in the Gujarati population.

  5. Estimation of fracture toughness of cast stainless steels during thermal aging in LWR systems-revision 1

    International Nuclear Information System (INIS)

    This report presents a revision of the procedure and correlations presented earlier in NUREG/CR-4513, ANL-90/42 (June 1991) for predicting the change in mechanical properties of cast stainless steel components due to thermal aging during service in light water reactors at 280-330 degrees C (535-625 degrees F). The correlations presented in this report are based on an expanded data base and have been optimized with mechanical-property data on cast stainless steels aged up to ∼58,000 h at 290-350 degrees C (554-633 degrees F). The fracture toughness J-R curve, tensile stress, and Charpy-impact energy of aged cast stainless steels are estimated from known material information. Mechanical properties of a specific cast stainless steel are estimated from the extent and kinetics of thermal embrittlement. Embrittlement of cast stainless steels is characterized in terms of room-temperature Charpy-impact energy. Charpy-impact energy as a function of time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which are also determined from the chemical composition. The initial impact energy of the unaged steel is required for these estimations. Initial tensile flow stress is needed for estimating the flow stress of the aged material. The fracture toughness J-R curve for the material is then obtained by correlating room-temperature Charpy-impact energy with fracture toughness parameters. The values of JIC are determined from the estimated J-R curve and flow stress. A common open-quotes predicted lower-boundclose quotes J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, range of ferrite content, and temperature. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented

  6. Estimation of age-specific per capita home-produced food intake among populations that garden, farm, or raise animals.

    Science.gov (United States)

    Phillips, Linda; Moya, Jacqueline

    2012-01-01

    Intake of home-produced foods may be a concern in areas where chemical contamination exists. Estimating exposure to contaminants in home-produced foods requires knowledge of the amount of these foods consumed. The US Environmental Protection Agency's (US EPA's) Exposure Factors Handbook provides data on consumption of home-produced foods based on the US Department of Agriculture's (USDA's) 1987-1988 Nationwide Food Consumption Survey (NFCS), the most recent national food survey that contains the information necessary to estimate home-produced consumption. These data represent "consumer-only" intake rate distributions for various age and demographic categories. "Consumers-only" information is also provided for households who garden, farm, and raise animals for all age groups combined. However, these "consumer-only" values may not always be appropriate when assessing chronic exposures. Furthermore, data for all ages combined may not be useful for estimating exposure among age groups that may be of particular concern. This paper provides age-specific "per capita" intake rate distributions of home-produced foods specifically for the populations that garden, farm, and raise animals, using data from EPA's Exposure Factors Handbook. PMID:21522189

  7. Learning Multiple Band-Pass Filters for Sleep Stage Estimation: Towards Care Support for Aged Persons

    Science.gov (United States)

    Takadama, Keiki; Hirose, Kazuyuki; Matsushima, Hiroyasu; Hattori, Kiyohiko; Nakajima, Nobuo

    This paper proposes the sleep stage estimation method that can provide an accurate estimation for each person without connecting any devices to human's body. In particular, our method learns the appropriate multiple band-pass filters to extract the specific wave pattern of heartbeat, which is required to estimate the sleep stage. For an accurate estimation, this paper employs Learning Classifier System (LCS) as the data-mining techniques and extends it to estimate the sleep stage. Extensive experiments on five subjects in mixed health confirm the following implications: (1) the proposed method can provide more accurate sleep stage estimation than the conventional method, and (2) the sleep stage estimation calculated by the proposed method is robust regardless of the physical condition of the subject.

  8. Comparison between greulich-pyle and girdany-golden methods for estimating skeletal age of children in pakistan

    International Nuclear Information System (INIS)

    Objective: To compare Greulich-Pyle (GP) and Girdany-Golden (GG) methods for estimation of Skeletal Age (SA) in children referred to a tertiary care hospital in Karachi, Pakistan. Study Design: Cross-sectional study. Place and Duration of Study: Department of Radiology, The Aga Khan University Hospital, Karachi, Pakistan, from July 2010 to June 2012. Methodology: Children up to the age of 18 years, who had undergone X-ray for the evaluation of trauma were included. Each X-ray was interpreted using both methods by two consultant paediatric radiologists having at least 10 years experience, who were blinded to the actual Chronologic Age (CA) of children. Results: A total of 283 children were included. No significant difference was noted in mean SA estimated by GP method and mean CA for female children (p=0.695). However, a significant difference was noted between mean CA and mean SA by GG method for females (p=0.011). For males, there was a significant difference between mean CA and mean SA estimated by both GP and GG methods. A stronger correlation was found between CA and SA estimated by GP method (r=0.943 for girls, r=0.915 for boys) as compared to GG method (r=0.909 for girls, r=0.865 for boys) respectively. Bland- Altman analysis also revealed that the two methods cannot be used interchangeably. Excellent correlation was seen between the two readers for both GP and GG methods. Conclusion: There was no additional benefit of using GP and GG methods simultaneously over using GP method alone. Moreover, although GP was reliable in estimating SA in girls, it was unable to accurately assess SA in boys. Therefore, it would be ideal to develop indigenous standards of bone age estimation based on a representative sample of healthy native children. (author)

  9. Effects of age, weight, and fat slaughter end points on estimates of breed and retained heterosis effects for carcass traits.

    Science.gov (United States)

    Ríos-Utrera, A; Cundiff, L V; Gregory, K E; Koch, R M; Dikeman, M E; Koohmaraie, M; Van Vleck, L D

    2006-01-01

    The influence of different levels of adjusted fat thickness (AFT) and HCW slaughter end points (covariates) on estimates of breed and retained heterosis effects was studied for 14 carcass traits from serially slaughtered purebred and composite steers from the US Meat Animal Research Center (MARC). Contrasts among breed solutions were estimated at 0.7, 1.1, and 1.5 cm of AFT, and at 295.1, 340.5, and 385.9 kg of HCW. For constant slaughter age, contrasts were adjusted to the overall mean (432.5 d). Breed effects for Red Poll, Hereford, Limousin, Braunvieh, Pinzgauer, Gelbvieh, Simmental, Charolais, MARC I, MARC II, and MARC III were estimated as deviations from Angus. In addition, purebreds were pooled into 3 groups based on lean-to-fat ratio, and then differences were estimated among groups. Retention of combined individual and maternal heterosis was estimated for each composite. Mean retained heterosis for the 3 composites also was estimated. Breed rankings and expression of heterosis varied within and among end points. For example, Charolais had greater (P or = 0.05) at a constant age. The MARC III composite produced 9.7 kg more (P < 0.01) fat than Angus at AFT of 0.7 cm, but 7.9 kg less (P < 0.05) at AFT of 1.5 cm. For MARC III, the estimate of retained heterosis for HCW was significant (P < 0.05) at the lowest level of AFT, but at the intermediate and greatest levels estimates were nil. The pattern was the same for MARC I and MARC III for LM area. Adjustment for age resulted in near zero estimates of retained heterosis for AFT, and similarly, adjustment for HCW resulted in nil estimates of retained heterosis for LM area. For actual retail product as a percentage of HCW, the estimate of retained heterosis for MARC III was negative (-1.27%; P < 0.05) at 0.7 cm but was significantly positive (2.55%; P < 0.05) at 1.5 cm of AFT. Furthermore, for MARC III, estimates of heterosis for some traits (fat as a percentage of HCW as another example) also doubled in magnitude

  10. Evaluation of age estimation in forensic medicine by examination of medial clavicular ossification from thin-slice computed tomography images.

    Science.gov (United States)

    Gurses, Murat Serdar; Inanir, Nursel Turkmen; Gokalp, Gokhan; Fedakar, Recep; Tobcu, Eren; Ocakoglu, Gokhan

    2016-09-01

    Forensic age estimation, a recent topic of research in forensic medicine, is of primary importance to criminal and civil law. Previous studies indicate that the observation of medial clavicular ossification allows for age discrimination along the completed 18th and 21st years of life. Experts recommend that the Schmeling and Kellinghaus methods be used together. In this study, we used these staging methods to retrospectively analyze 725 case studies (385 males, 340 females) of thin-slice computed tomography (CT) images, ranging from 0.6 to 1 mm in thickness, from individuals aged 10 to 35 years. Stage 1 was found at 18 years of age maximum for males, whereas it was found at 17 years of age for females. Stage 2a was found at 18 years of age maximum for both genders. Stage 3c was initially observed at 18 years for both genders. Stage 4 was initially found at 21 years for males and 20 years for females. Stage 5 was initially observed at 25 years for both genders. Of note, stage 3c was found close to 19 years of age for both genders (18.92 years for male, 18.99 years for female), and it may be employed to differentiate along the age majority cutoff. The data obtained from our study were consistent with previous studies. We believe that such a comprehensive database will greatly contribute to future studies focusing on medial clavicular ossification based on thin-slice CT. Moreover, we also recommend that if medial clavicular ossification based on CT is to be examined for forensic age estimation, both methods should be employed together. PMID:27352083

  11. The Solar Twin Planet Search III. The [Y/Mg] clock: estimating stellar ages of solar-type stars

    CERN Document Server

    Maia, M Tucci; Meléndez, J; Bedell, M; Bean, J L; Asplund, M

    2016-01-01

    Solar twins are stars with similar stellar (surface) parameters to the Sun that can have a wide range of ages. This provide an opportunity to analyze the variation of their chemical abundances with age. Nissen (2015) recently suggested that the abundances of the s-process element Y and the $\\alpha$-element Mg could be used to estimate stellar ages. This paper aims to determine with high precision the Y, Mg, and Fe abundances for a sample of 88 solar twins that span a broad age range ($0.3-10.0$\\,Gyr) and investigate their use for estimating ages. We obtained high-quality Magellan Inamori Kyocera Echelle (MIKE) spectra and determined Y and Mg abundances using equivalent widths and a line-by-line differential method within a 1D LTE framework. Stellar parameters and iron abundances were measured in Paper I of this series for all stars, but a few (three) required a small revision. The [Y/Mg] ratio shows a strong correlation with age. It has a slope of -0.041$\\pm$0.001 dex/Gyr and a significance of 41 $\\sigma$. Th...

  12. Application of X-rays to dental age estimation in medico-legal practice

    OpenAIRE

    Dorota Lorkiewicz-Muszyńska; Agnieszka Przystańska; Tomasz Kulczyk; Anna Hyrchała; Bartłomiej Bartecki; Wojciech Kociemba; Mariusz Glapiński; Marzena Łabęcka; Paweł Świderski

    2015-01-01

    Aim of the study: The paper addresses the use of dental age assessment methods based on radiographs in medico-legal practice. Different cases of practical application of the methods are presented including identification of human remains, dental age assessment in a living person and one archaeological case. Material and methods : The study material consisted of cases involving dental age assessment performed in the Department of Forensic Medicine, Poznan University of Medical Sciences ...

  13. Normative perceptual estimates for 91 healthy subjects age 60-75: impact of age, education, employment, physical exercise, alcohol, and video gaming.

    Science.gov (United States)

    Wilms, Inge L; Nielsen, Simon

    2014-01-01

    Visual perception serves as the basis for much of the higher level cognitive processing as well as human activity in general. Here we present normative estimates for the following components of visual perception: the visual perceptual threshold, the visual short-term memory (VSTM) capacity and the visual perceptual encoding/decoding speed (processing speed) of VSTM based on an assessment of 91 healthy subjects aged 60-75. The estimates were modeled from input from a whole-report assessment based on a theory of visual attention. In addition to the estimates themselves, we present correlational data, and multiple regression analyses between the estimates and self-reported demographic data and lifestyle variables. The regression statistics suggest that education level, video gaming activity, and employment status may significantly impact the encoding/decoding speed of VTSM but not the capacity of VSTM nor the visual perceptual threshold. The estimates will be useful for future studies into the effects of various types of intervention and training on cognition in general and visual attention in particular. PMID:25339932

  14. Interferometric processing of C-band SAR data for the improvement of stand age estimation in rubber plantation

    Science.gov (United States)

    Trisasongko, Bambang H.; Paull, David J.; Panuju, Dyah R.

    2015-01-01

    Rubber ranks the second largest plantation in Indonesia after oil palm. While oil palm plantations have been exploited mainly by large companies, many rubber plantations are still managed by peasant farmers who maintain its biodiversity. Due to its broad and scattered location, monitoring tropical rubber plantation is a crucial application of active remote sensing. In this paper, the backscatter coefficient of Envisat Advanced Synthetic Aperture Radar (ASAR) is compared to interferometric coherence to study the relationship between stand age and SAR parameters. It is shown that VV polarized C-band SAR achieves its saturation level in plantations aged about 5-10 years. Extension of saturation level can be achieved by processing an interferometric pair of ASAR data, which results in interferometric coherence. In this paper, coherence can take up to 20 years stand age to achieve prior to saturation. Since stand age is highly related to biomass, this finding argues that the biomass can be best estimated using coherence.

  15. Study on life estimation of cable insulation by gas evolution and oxygen consumption during radiation and thermal aging

    International Nuclear Information System (INIS)

    Ethylene-propylene rubber (EP rubber), as cable insulating materials used in domestic nuclear power plants, was preliminary exposed to γ-rays, and was aged in oxygen atmosphere. O2 consumption and gas evolution during γ-radiation and thermal aging were measured by gas chromatography, and were compared with tensile properties of aged EP rubber. O2 consumption, CO evolution and CO2 evolution during the degradation of EP rubber increased with proceeding degradation, that is, oxidation of polymer. Elongation at break of aged EP rubber was found to be related to O2 consumption and CO2 evolution during the degradation, and the relation was scarcely affected by radiation dose and temperature. Therefore, these O2 and CO2 measurements may be useful to estimate quantitatively the degree of polymer degradation. (J.P.N.)

  16. A Bayesian modeling approach for estimation of a shape-free groundwater age distribution using multiple tracers

    International Nuclear Information System (INIS)

    Highlights: • A Bayesian method is used to infer the freeform (histogram) age distributions. • The value at each bin was estimated using MCMC approach. • The method was applied to a synthetic tracer dataset and two real datasets. • The cumulative age distribution is captured better than the non-cumulative. • Less uncertainty is obtained when smaller number of bins is used. - Abstract: Due to the mixing of groundwaters with different ages in aquifers, groundwater age is more appropriately represented by a distribution rather than a scalar number. To infer a groundwater age distribution from environmental tracers, a mathematical form is often assumed for the shape of the distribution and the parameters of the mathematical distribution are estimated using deterministic or stochastic inverse methods. The prescription of the mathematical form limits the exploration of the age distribution to the shapes that can be described by the selected distribution. In this paper, the use of freeform histograms as groundwater age distributions is evaluated. A Bayesian Markov Chain Monte Carlo approach is used to estimate the fraction of groundwater in each histogram bin. The method was able to capture the shape of a hypothetical gamma distribution from the concentrations of four age tracers. The number of bins that can be considered in this approach is limited based on the number of tracers available. The histogram method was also tested on tracer data sets from Holten (The Netherlands; 3H, 3He, 85Kr, 39Ar) and the La Selva Biological Station (Costa-Rica; SF6, CFCs, 3H, 4He and 14C), and compared to a number of mathematical forms. According to standard Bayesian measures of model goodness, the best mathematical distribution performs better than the histogram distributions in terms of the ability to capture the observed tracer data relative to their complexity. Among the histogram distributions, the four bin histogram performs better in most of the cases. The Monte Carlo

  17. Raman spectroscopy of human skin: looking for a quantitative algorithm to reliably estimate human age.

    Science.gov (United States)

    Pezzotti, Giuseppe; Boffelli, Marco; Miyamori, Daisuke; Uemura, Takeshi; Marunaka, Yoshinori; Zhu, Wenliang; Ikegaya, Hiroshi

    2015-06-01

    The possibility of examining soft tissues by Raman spectroscopy is challenged in an attempt to probe human age for the changes in biochemical composition of skin that accompany aging. We present a proof-of-concept report for explicating the biophysical links between vibrational characteristics and the specific compositional and chemical changes associated with aging. The actual existence of such links is then phenomenologically proved. In an attempt to foster the basics for a quantitative use of Raman spectroscopy in assessing aging from human skin samples, a precise spectral deconvolution is performed as a function of donors' ages on five cadaveric samples, which emphasizes the physical significance and the morphological modifications of the Raman bands. The outputs suggest the presence of spectral markers for age identification from skin samples. Some of them appeared as authentic "biological clocks" for the apparent exactness with which they are related to age. Our spectroscopic approach yields clear compositional information of protein folding and crystallization of lipid structures, which can lead to a precise identification of age from infants to adults. Once statistically validated, these parameters might be used to link vibrational aspects at the molecular scale for practical forensic purposes. PMID:26112367

  18. Age-distribution estimation for karst groundwater: Issues of parameterization and complexity in inverse modeling by convolution

    Science.gov (United States)

    Long, A.J.; Putnam, L.D.

    2009-01-01

    Convolution modeling is useful for investigating the temporal distribution of groundwater age based on environmental tracers. The framework of a quasi-transient convolution model that is applicable to two-domain flow in karst aquifers is presented. The model was designed to provide an acceptable level of statistical confidence in parameter estimates when only chlorofluorocarbon (CFC) and tritium (3H) data are available. We show how inverse modeling and uncertainty assessment can be used to constrain model parameterization to a level warranted by available data while allowing major aspects of the flow system to be examined. As an example, the model was applied to water from a pumped well open to the Madison aquifer in central USA with input functions of CFC-11, CFC-12, CFC-113, and 3H, and was calibrated to several samples collected during a 16-year period. A bimodal age distribution was modeled to represent quick and slow flow less than 50 years old. The effects of pumping and hydraulic head on the relative volumetric fractions of these domains were found to be influential factors for transient flow. Quick flow and slow flow were estimated to be distributed mainly within the age ranges of 0-2 and 26-41 years, respectively. The fraction of long-term flow (>50 years) was estimated but was not dateable. The different tracers had different degrees of influence on parameter estimation and uncertainty assessments, where 3H was the most critical, and CFC-113 was least influential.

  19. Estimated aortic stiffness is independently associated with cardiac baroreflex sensitivity in humans: role of ageing and habitual endurance exercise.

    Science.gov (United States)

    Pierce, G L; Harris, S A; Seals, D R; Casey, D P; Barlow, P B; Stauss, H M

    2016-09-01

    We hypothesised that differences in cardiac baroreflex sensitivity (BRS) would be independently associated with aortic stiffness and augmentation index (AI), clinical biomarkers of cardiovascular disease risk, among young sedentary and middle-aged/older sedentary and endurance-trained adults. A total of 36 healthy middle-aged/older (age 55-76 years, n=22 sedentary and n=14 endurance-trained) and 5 young sedentary (age 18-31 years) adults were included in a cross-sectional study. A subset of the middle-aged/older sedentary adults (n=12) completed an 8-week-aerobic exercise intervention. Invasive brachial artery blood pressure waveforms were used to compute spontaneous cardiac BRS (via sequence technique), estimated aortic pulse wave velocity (PWV) and AI (AI, via brachial-aortic transfer function and wave separation analysis). In the cross-sectional study, cardiac BRS was 71% lower in older compared with young sedentary adults (P<0.05), but only 40% lower in older adults who performed habitual endurance exercise (P=0.03). In a regression model that included age, sex, resting heart rate, mean arterial pressure (MAP), body mass index and maximal exercise oxygen uptake, estimated aortic PWV (β±s.e.=-5.76±2.01, P=0.01) was the strongest predictor of BRS (model R(2)=0.59, P<0.001). The 8-week-exercise intervention improved BRS by 38% (P=0.04) and this change in BRS was associated with improved aortic PWV (r=-0.65, P=0.044, adjusted for changes in MAP). Age- and endurance-exercise-related differences in cardiac BRS are independently associated with corresponding alterations in aortic PWV among healthy adults, consistent with a mechanistic link between variations in the sensitivity of the baroreflex and aortic stiffness with age and exercise. PMID:26911535

  20. Age-dependent dynamics of screening metabolic parameters in long-livers and its biophysical estimation

    Directory of Open Access Journals (Sweden)

    Denisova Т.Р.

    2015-03-01

    Full Text Available The purpose of the study: to examine age-dependent dynamics of parameters of biochemical screening in long-livers. Material and methods. The study included 201 long-livers divided (Saratov into two groups: the main group (centenarians and the control group (90-99 y.o.. Basic parameters of biochemical screening were analyzed. Results. The suited sample of centenarians characterized by significantly lower levels of total cholesterol, triglycerids, glucose and creatinine. All studied parameters progrediently decreased from early long-livers age to centenarians. Maximal rates of age dependencies allowed us to confirm maximal weight of lipids in early longevity and glucose and creatinine in centenarians. Conclusion. All present results are most likely explained by the combined effects of genetic, environmental and "hundred years" factors leading to dynamic remodeling of control systems. Major result of such remodeling is age-dependent optimal level of metabolic factors as a mechanism of successive ageing.

  1. Official population statistics and the Human Mortality Database estimates of populations aged 80+ in Germany and nine other European countries

    Directory of Open Access Journals (Sweden)

    Dmitri A. Jdanov

    2005-11-01

    Full Text Available A systematic comparison of the Human Mortality Database and official estimates of populations aged 80+ is presented. We consider statistical series for East and West Germany and also for Denmark, England and Wales, France, Finland, Hungary, the Netherlands, Russia, Sweden, and Switzerland. The Human Mortality Database (HMD, www.mortality.org methodology relies on the methods of extinct and almost extinct generations. HMD estimates are precise if the quality of death data is high and the migration among the elderly is negligible. The comparisons between the HMD and the official populations are not fully appropriate for the 1990s since the HMD calculations are related to official population estimates. A significant overestimation of the male population aged 80+ and especially 90+ between the censuses of 1970 and 1987 was found in West Germany. The relative surplus of men aged 90+ increased from 5 to 20 percent, which expressed in absolute numbers indicates an increase from 2 to 10 thousand. In 1971-1987 the official death rates have fallen dramatically to implausibly low values. In 1987-88 death rates based on the official populations suddenly jumped to the HMD death rates due to the census re-estimation. In the 1990s an accelerated decrease in male death rates has resumed. Among other countries, the relative and absolute deviations from the HMD estimates were especially high in Russia, Hungary, and England and Wales. Regression analysis reveals common factors of the relative deviation from the HMD populations. The deviation tends to decrease with time, increase with age, be higher during inter-census periods than in census years, and to decrease after the introduction of population registers.

  2. Aging.

    Science.gov (United States)

    Park, Dong Choon; Yeo, Seung Geun

    2013-09-01

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

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Manuella; Santos Carneiro; Beltraeo, Rejane Targino; Beltraeo, Ricardo Villar [School of Dentistry, Federal University of Paraiba, Joaeo Pessoa (Brazil); Pontual, Andrea dos Anjos [Pernambuco Dental School, Pernambuco University-UPE, Camaragibe (Brazil); Pontual, Maria Luiza dos Anjos [Federal University of Pernambuco, Recife (Brazil)

    2013-03-15

    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.

  5. Improved estimates of age, growth and reproduction for the regionally endemic Galapagos sailfin grouper Mycteroperca olfax (Jenyns, 1840).

    Science.gov (United States)

    Usseglio, Paolo; Friedlander, Alan M; DeMartini, Edward E; Schuhbauer, Anna; Schemmel, Eva; Salinas de Léon, Pelayo

    2015-01-01

    The Galapagos Sailfin grouper, Mycteroperca olfax, locally known as bacalao and listed as vulnerable by the IUCN, is culturally, economically, and ecologically important to the Galapagos archipelago and its people. It is regionally endemic to the Eastern Tropical Pacific, and, while an important fishery resource that has shown substantial declines in recent years, to date no effective management regulations are in place to ensure the sustainability of the Galapagos fishery for this species. Previous estimates of longevity and size at maturity for bacalao are inconsistent with estimates for congeners, which brings into question the accuracy of prior estimates. We set out to assess the age, growth, and reproductive biology of bacalao in order to provide more accurate life history information to inform more effective fisheries management for this species. The oldest fish in our sample was 21 years old, which is 2-3 times greater than previously reported estimates of longevity. Parameter estimates for the von Bertalanffy growth function (k = 0.11, L ∞ = 110 cm TL, and to = - 1.7 years) show bacalao to grow much slower and attain substantially larger asymptotic maximum length than previous studies. Mean size at maturity (as female) was estimated at 65.3 cm TL, corresponding to a mean age of 6.5 years. We found that sex ratios were extremely female biased (0.009 M:1F), with a large majority of the individuals in our experimental catch being immature (79%). Our results show that bacalao grow slower, live longer, and mature at a much larger size and greater age than previously thought, with very few mature males in the population. These findings have important implications for the fishery of this valuable species and provide the impetus for a long-overdue species management plan to ensure its long-term sustainability. PMID:26401463

  6. Decision-model estimation of the age-specific disability weight for schistosomiasis japonica: a systematic review of the literature.

    Directory of Open Access Journals (Sweden)

    Julia L Finkelstein

    Full Text Available Schistosomiasis is among the most prevalent parasitic infections worldwide. However, current Global Burden of Disease (GBD disability-adjusted life year estimates indicate that its population-level impact is negligible. Recent studies suggest that GBD methodologies may significantly underestimate the burden of parasitic diseases, including schistosomiasis. Furthermore, strain-specific disability weights have not been established for schistosomiasis, and the magnitude of human disease burden due to Schistosoma japonicum remains controversial. We used a decision model to quantify an alternative disability weight estimate of the burden of human disease due to S. japonicum. We reviewed S. japonicum morbidity data, and constructed decision trees for all infected persons and two age-specific strata, or =15 y. We conducted stochastic and probabilistic sensitivity analyses for each model. Infection with S. japonicum was associated with an average disability weight of 0.132, with age-specific disability weights of 0.098 ( or =15 y. Re-estimated disability weights were seven to 46 times greater than current GBD measures; no simulations produced disability weight estimates lower than 0.009. Nutritional morbidities had the greatest contribution to the S. japonicum disability weight in the <15 y model, whereas major organ pathologies were the most critical variables in the older age group. GBD disability weights for schistosomiasis urgently need to be revised, and species-specific disability weights should be established. Even a marginal increase in current estimates would result in a substantial rise in the estimated global burden of schistosomiasis, and have considerable implications for public health prioritization and resource allocation for schistosomiasis research, monitoring, and control.

  7. Estimation of Genetic Parameters for Real-time Ultrasound Measurements for Hanwoo Cows at Different Ages and Pregnancy Status

    OpenAIRE

    Lee, J. H.; Lee, Y M; Oh, S. -H.; Son, H J; Jeong, D. J.; Whitley, Niki; Kim, J.J.

    2014-01-01

    The purpose of this study was to estimate genetic parameters of ultrasound measurements for longissimus dorsi muscle area (LMA), backfat thickness (BFT), and marbling score (MS) in Hanwoo cows (N = 3,062) at the ages between 18 and 42 months. Data were collected from 100 Hanwoo breeding farms in Gyeongbuk province, Korea, in 2007 and 2008. The cows were classified into four different age groups, i.e. 18 to 22 months (the first pregnancy period), 23 to 27 (the first parturition), 28 to 32 (the...

  8. Exploiting quality and texture features to estimate age and gender from fingerprints

    Science.gov (United States)

    Marasco, Emanuela; Lugini, Luca; Cukic, Bojan

    2014-05-01

    Age and gender of an individual, when available, can contribute to identification decisions provided by primary biometrics and help improve matching performance. In this paper, we propose a system which automatically infers age and gender from the fingerprint image. Current approaches for predicting age and gender generally exploit features such as ridge count, and white lines count that are manually extracted. Existing automated approaches have significant limitations in accuracy especially when dealing with data pertaining to elderly females. The model proposed in this paper exploits image quality features synthesized from 40 different frequency bands, and image texture properties captured using the Local Binary Pattern (LBP) and the Local Phase Quantization (LPQ) operators. We evaluate the performance of the proposed approach using fingerprint images collected from 500 users with an optical sensor. The approach achieves prediction accuracy of 89.1% for age and 88.7% for gender.

  9. The Solar Twin Planet Search. III. The [Y/Mg] clock: estimating stellar ages of solar-type stars

    Science.gov (United States)

    Tucci Maia, M.; Ramírez, I.; Meléndez, J.; Bedell, M.; Bean, J. L.; Asplund, M.

    2016-05-01

    Context. Solar twins are stars with similar stellar (surface) parameters to the Sun that can have a wide range of ages. This provides an opportunity to analyze the variation of their chemical abundances with age. Nissen (2015, A&A, 579, A52) recently suggested that the abundances of the s-process element Y and the α-element Mg could be used to estimate stellar ages. Aims: This paper aims to determine with high precision the Y, Mg, and Fe abundances for a sample of 88 solar twins that span a broad age range (0.3-10.0 Gyr) and investigate their use for estimating ages. Methods: We obtained high-quality Magellan Inamori Kyocera Echelle (MIKE) spectra and determined Y and Mg abundances using equivalent widths and a line-by-line differential method within a 1D LTE framework. Stellar parameters and iron abundances were measured in Paper I of this series for all stars, but a few (three) required a small revision. Results: The [Y/Mg] ratio shows a strong correlation with age. It has a slope of -0.041 ± 0.001 dex/Gyr and a significance of 41σ. This is in excellent agreement with the relation first proposed by Nissen (2015). We found some outliers that turned out to be binaries where mass transfer may have enhanced the yttrium abundance. Given a precise measurement of [Y/Mg] with typical error of 0.02 dex in solar twins, our formula can be used to determine a stellar age with ~0.8 Gyr precision in the 0 to 10 Gyr range. Based on observations obtained at the Clay Magellan Telescopes at Las Campanas Observatory, Chile and at the 3.6 m Telescope at the La Silla ESO Observatory, Chile (program ID 188.C-0265).

  10. Measuring International Skilled Migration: New Estimates Controlling for Age of Entry

    OpenAIRE

    Beine, M; Docquier, F; Rapoport, H

    2006-01-01

    Recent data on international skilled migration define skilled migrants according to education level independently of whether education has been acquired in the home or in the host country. In this paper we use immigrants’ age of entry as a proxy for where education has been acquired. Data on age of entry are available from a subset of receiving countries which together represent more than 3/4 of total skilled immigration to the OECD. Using these data and a simple gravity model,...

  11. A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality

    OpenAIRE

    Trenkel, Verena M.; Bravington, Mark V.; Lorance, Pascal; Walters , Carl

    2012-01-01

    Catch curves are widely used to estimate total mortality for exploited marine populations. The usual population dynamics model assumes constant recruitment across years and constant total mortality. We extend this to include annual recruitment and annual total mortality. Recruitment is treated as an uncorrelated random effect, while total mortality is modelled by a random walk. Data requirements are minimal as only proportions-at-age and total catches are needed. We obtain the effective sampl...

  12. Risk Factors for Learning-Related Behavior Problems at 24 Months of Age: Population-Based Estimates

    OpenAIRE

    Morgan, Paul

    2009-01-01

    We used a large sample of singleton children to estimate the effects of socioeconomic status (SES), race/ethnicity, gender, additional socio-demographics, gestational and birth factors, and parenting on children's risk for learning-related behavior problems at 24 months of age. We investigated to what extent these factors increased a child's risk of displaying inattention, a lack of task persistence, disinterest, non-cooperation, or frustration as he or she completed a series of cognitive and...

  13. Age estimation by facial image: a survey%人脸图像的年龄估计技术研究

    Institute of Scientific and Technical Information of China (English)

    王先梅; 梁玲燕; 王志良; 胡四泉

    2012-01-01

    Age information, as an important personal trait, has great potential in safety surveillance, human-computer interaction, multimedia applications, and face recognition. As an emerging biometric information identification technology, face-image based age estimation has gained great attention resently and has become one of the important research topics in machine learning and computer vision. In this paper, we survey most existing commonly used methods in face-image based age estimation, especially focusing on the extraction of age features and classification. Then, we also introduce some face aging databases and evaluation protocols, which are widely used at present. Based on these databases and evaluation methods, a comparison of the performances of several age estimation systems is presented. Finally, the challenges and promising directions of age estimation techniques are discussed.%年龄信息作为人体的一种重要生物特征,在安全监控、人机交互、视频检索等领域有着巨大的应用潜力,并且是人脸识别技术的主要瓶颈问题之一.基于人脸图像的年龄估计技术作为一种新兴的生物特征识别技术,目前已经成为计算机视觉、人机交互等领域的一个重要研究课题.为此对国内外近几年来在年龄估计技术方面的发展情况进行了综述,主要包括年龄特征提取与年龄分类模式两大部分.同时对常用的年龄数据库、性能评价指标进行了总结,并在此基础上对当前的一些年龄估计系统的性能进行了对比.最后,对基于人脸图像的年龄估计技术所面临的挑战以及可能的发展方向进行了讨论.

  14. The transverse diameter of the chest on routine radiographs reliably estimates gestational age and weight in premature infants

    International Nuclear Information System (INIS)

    Prior to digital radiography it was possible for a radiologist to easily estimate the size of a patient on an analog film. Because variable magnification may be applied at the time of processing an image, it is now more difficult to visually estimate an infant's size on the monitor. Since gestational age and weight significantly impact the differential diagnosis of neonatal diseases and determine the expected size of kidneys or appearance of the brain by MRI or US, this information is useful to a pediatric radiologist. Although this information may be present in the electronic medical record, it is frequently not readily available to the pediatric radiologist at the time of image interpretation. To determine if there was a correlation between gestational age and weight of a premature infant with their transverse chest diameter (rib to rib) on admission chest radiographs. This retrospective study was approved by the institutional review board, which waived informed consent. The maximum transverse chest diameter outer rib to outer rib was measured on admission portable chest radiographs of 464 patients admitted to the neonatal intensive care unit (NICU) during the 2010 calendar year. Regression analysis was used to investigate the association between chest diameter and gestational age/birth weight. Quadratic term of chest diameter was used in the regression model. Chest diameter was statistically significantly associated with both gestational age (P < 0.0001) and birth weight (P < 0.0001). An infant's gestational age and birth weight can be reliably estimated by comparing a simple measurement of the transverse chest diameter on digital chest radiograph with the tables and graphs in our study. (orig.)

  15. The transverse diameter of the chest on routine radiographs reliably estimates gestational age and weight in premature infants

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, Kelly R. [University of Minnesota, Department of Radiology, Minneapolis, MN (United States); Zhang, Lei [University of Minnesota, Biostatistical Design and Analysis Center, Minneapolis, MN (United States); Seidel, Frank G. [Lucile Packard Children' s Hospital, Department of Radiology, Stanford, CA (United States)

    2015-08-15

    Prior to digital radiography it was possible for a radiologist to easily estimate the size of a patient on an analog film. Because variable magnification may be applied at the time of processing an image, it is now more difficult to visually estimate an infant's size on the monitor. Since gestational age and weight significantly impact the differential diagnosis of neonatal diseases and determine the expected size of kidneys or appearance of the brain by MRI or US, this information is useful to a pediatric radiologist. Although this information may be present in the electronic medical record, it is frequently not readily available to the pediatric radiologist at the time of image interpretation. To determine if there was a correlation between gestational age and weight of a premature infant with their transverse chest diameter (rib to rib) on admission chest radiographs. This retrospective study was approved by the institutional review board, which waived informed consent. The maximum transverse chest diameter outer rib to outer rib was measured on admission portable chest radiographs of 464 patients admitted to the neonatal intensive care unit (NICU) during the 2010 calendar year. Regression analysis was used to investigate the association between chest diameter and gestational age/birth weight. Quadratic term of chest diameter was used in the regression model. Chest diameter was statistically significantly associated with both gestational age (P < 0.0001) and birth weight (P < 0.0001). An infant's gestational age and birth weight can be reliably estimated by comparing a simple measurement of the transverse chest diameter on digital chest radiograph with the tables and graphs in our study. (orig.)

  16. Estimation of age dependent effective dose due to intake of 226Ra from drinking water in Vizag, India

    International Nuclear Information System (INIS)

    As a part of the ongoing baseline survey, present work deals with the measurement of 226Ra concentration in ground water samples collected around Bhabha Atomic Research Center (BARC) site Vizag by emanometry technique and subsequent estimation of age dependent effective dose to the people inhabited in that area. The mean activity concentration of 226Ra was 15.8 mBq/L which is much lower than the WHO guideline value of 1 Bq/L. The highest dose was observed for the age group of 14-18 yr (male). The dose for all age group are ranged between 2.2-56 which is well below the WHO recommended dose level of 100 μSv/y. (author)

  17. An HST/WFPC2 survey of bright young clusters in M31. IV. Ages and mass estimates

    CERN Document Server

    Perina, S; Barmby, P; Beasley, M A; Bellazzini, M; Brodie, J P; Federici, L; Pecci, F Fusi; Galleti, S; Hodge, P W; Huchra, J P; Kissler-Patig, M; Puzia, T H; Strader, J

    2009-01-01

    {Aims.} We present the main results of an imaging survey of possible young massive clusters (YMC) in M31 performed with the Wide Field and Planetary Camera2 (WFPC2) on the Hubble Space Telescope (HST). We present the images and color magnitude diagrams (CMDs) of all of our targets. {Methods.} The reddening, age and, metallicity of the clusters were estimated by comparing the observed CMDs and luminosity functions with theoretical models. Stellar masses were estimated by comparison with theoretical models in the log(Age) vs. absolute integrated magnitude plane. {Results.} Nineteen of the twenty surveyed candidates were confirmed to be real star clusters. Three of the clusters were found not to be good YMC candidates from newly available integrated spectroscopy and were in fact found to be old from their CMD. Of the remaining sixteen clusters, fourteen have ages between 25 Myr and 280 Myr, two have older ages than 500 Myr (lower limits). By including ten other YMC with HST photometry from the literature we have...

  18. The genus Cecropia: a biological clock to estimate the age of recently disturbed areas in the Neotropics.

    Directory of Open Access Journals (Sweden)

    Paul-Camilo Zalamea

    Full Text Available Forest successional processes following disturbance take decades to play out, even in tropical forests. Nonetheless, records of vegetation change in this ecosystem are scarce, increasing the importance of the chronosequence approach to study forest recovery. However, this approach requires accurate dating of secondary forests, which until now was a difficult and/or expensive task. Cecropia is a widespread and abundant pioneer tree genus of the Neotropics. Here we propose and validate a rapid and straightforward method to estimate the age of secondary forest patches based on morphological observations of Cecropia trees. We found that Cecropia-inferred ages were highly correlated with known ages of the forest. We also demonstrate that Cecropia can be used to accurately date disturbances and propose twenty-one species distributed all over the geographical range of the genus as potential secondary forest chronometer species. Our method is limited in applicability by the maximal longevity of Cecropia individuals. Although the oldest chronosequence used in this study was 20 years old, we argue that at least for the first four decades after disturbance, the method described in this study provides very accurate estimations of secondary forest ages. The age of pioneer trees provides not only information needed to calculate the recovery of carbon stocks that would help to improve forest management, but also provides information needed to characterize the initial floristic composition and the rates of species remigration into secondary forest. Our contribution shows how successional studies can be reliably and inexpensively extended without the need to obtain forest ages based on expensive or potentially inaccurate data across the Neotropics.

  19. NMR imaging estimates of muscle volume and intramuscular fat infiltration in the thigh: variations with muscle, gender, and age.

    Science.gov (United States)

    Hogrel, Jean-Yves; Barnouin, Yoann; Azzabou, Noura; Butler-Browne, Gillian; Voit, Thomas; Moraux, Amélie; Leroux, Gaëlle; Behin, Anthony; McPhee, Jamie S; Carlier, Pierre G

    2015-06-01

    Muscle mass is particularly relevant to follow during aging, owing to its link with physical performance and autonomy. The objectives of this work were to assess muscle volume (MV) and intramuscular fat (IMF) for all the muscles of the thigh in a large population of young and elderly healthy individuals using magnetic resonance imaging (MRI) to test the effect of gender and age on MV and IMF and to determine the best representative slice for the estimation of MV and IMF. The study enrolled 105 healthy young (range 20-30 years) and older (range 70-80 years) subjects. MRI scans were acquired along the femur length using a three-dimension three-point Dixon proton density-weighted gradient echo sequence. MV and IMF were estimated from all the slices. The effects of age and gender on MV and IMF were assessed. Predictive equations for MV and IMF were established using a single slice at various femur levels for each muscle in order to reduce the analysis process. MV was decreased with aging in both genders, particularly in the quadriceps femoris. IMF was largely increased with aging in men and, to a lesser extent, in women. Percentages of MV decrease and IMF increase with aging varied according to the muscle. Predictive equations to predict MV and IMF from single slices are provided and were validated. This study is the first one to provide muscle volume and intramuscular fat infiltration in all the muscles of the thigh in a large population of young and elderly healthy subjects. PMID:26040416

  20. Geostatistical model-based estimates of schistosomiasis prevalence among individuals aged = 20 years in West Africa

    DEFF Research Database (Denmark)

    Schur, Nadine; Hürlimann, Eveline; Garba, Amadou;

    2011-01-01

    Schistosomiasis is a water-based disease that is believed to affect over 200 million people with an estimated 97% of the infections concentrated in Africa. However, these statistics are largely based on population re-adjusted data originally published by Utroska and colleagues more than 20 years...... ago. Hence, these estimates are outdated due to large-scale preventive chemotherapy programs, improved sanitation, water resources development and management, among other reasons. For planning, coordination, and evaluation of control activities, it is essential to possess reliable schistosomiasis...

  1. ESTIMATION CRITERIA FOR DEGREE OF PAPER-IMPREGNATED INSULATED POWER CABLE AGEING

    Directory of Open Access Journals (Sweden)

    G.V. Bezprozvannych

    2013-09-01

    Full Text Available Correlation between parameters characterizing mechanical and thermal ageing of paper-impregnated insulation of medium voltage power cables is revealed. On the basis of linear and exponential regression analysis at confidence coefficient of 0.95, critical values of dielectric loss tangent of wrapping and phase insulation corresponding to the cable life termination are found.

  2. Unbiased Stereological Analysis of Reactive Astrogliosis to Estimate Age-Associated Cerebral White Matter Injury.

    Science.gov (United States)

    McNeal, David W; Brandner, Dieter D; Gong, Xi; Postupna, Nadia O; Montine, Thomas J; Keene, C Dirk; Back, Stephen A

    2016-06-01

    Cerebral white matter injury (WMI) contributes to cognitive dysfunction associated with pathological aging. Because reactive astrocyte-related factors contribute to remyelination failure after WMI, we sought accurate, cost-effective, and reproducible histopathological approaches for quantification of morphometric features of reactive astrogliosis in aged human white matter in patients with vascular brain injury (VBI). We compared 7 distinct approaches to quantify the features of glial fibrillary acidic protein (GFAP)-labeled astrocytes in the prefrontal white matter of brains from patients with VBI (n = 17, mean age 88.8 years) and controls that did not exhibit VBI (n = 11, mean age 86.6 years). Only modern stereological techniques (ie, optical fractionator and spaceballs) and virtual process thickness measurements demonstrated significant changes in astrocyte number, process length, or proximal process thickness in cases with VBI relative to controls. The widely employed methods of neuropathological scoring, antibody capture assay (histelide), area fraction fractionator, and Cavalieri point counting failed to detect significant differences in GFAP expression between the groups. Unbiased stereological approaches and virtual thickness measurements provided the only sensitive and accurate means to quantify astrocyte reactivity as a surrogate marker of WMI in human brains with VBI. PMID:27142644

  3. Specific and unspecific gynecological alarm symptoms -prevalence estimates in different age groups

    DEFF Research Database (Denmark)

    Balasubramaniam, Kirubakaran; Ravn, Pernille; Larsen, Pia V;

    2015-01-01

    or above from the general population. METHODS: An internet-based questionnaire study regarding the prevalence estimates of symptom experiences. A total of 18 symptoms of cervical, endometrial and ovarian cancer were selected through an extensive literature search, which included national and...

  4. Estimating migratory game-bird productivity by integrating age ratio and banding data

    Science.gov (United States)

    Zimmerman, G.S.; Link, W.A.; Conroy, M.J.; Sauer, J.R.; Richkus, K.D.; Boomer, G. Scott

    2010-01-01

    Context: Reproduction is a critical component of fitness, and understanding factors that influence temporal and spatial dynamics in reproductive output is important for effective management and conservation. Although several indices of reproductive output for wide-ranging species, such as migratory birds, exist, there has been no theoretical justification for their estimators or associated measures of variance.

  5. INCREASING THE ACCURACY OF MAYFIELD ESTIMATES USING KNOWLEDGE OF NEST AGE

    Science.gov (United States)

    This presentation will focus on the error introduced in nest-survival modeling when nest-cycles are assumed to be of constant length. I will present the types of error that may occur, including biases resulting from incorrect estimates of expected values, as well as biases that o...

  6. Incidence estimation using a single cross-sectional age-specific prevalence survey with differential mortality.

    Science.gov (United States)

    Turner, Elizabeth L; Sweeting, Michael J; Lindfield, Robert J; Deangelis, Daniela

    2014-02-10

    Here, we present a method for incidence estimation of a curable, non-recurring disease when data from a single cross-sectional survey are used together with population-level mortality rates and an assumption of differential mortality of diseased versus non-diseased individuals. The motivating example is cataract, and the VISION2020 goal to eliminate avoidable blindness globally by 2020. Reliable estimates of current and future cataract disease burden are required to predict how many surgeries would need to be performed to meet the VISION2020 goals. However, incidence estimates, needed to derive future burden, are not as easily available, due to the cost of conducting cohort studies. Disease is defined at the person-level in accordance with the WHO person-level definition of blindness. An extension of the standard time homogeneous illness-death model to a four-state model is described, which allows the disease to be cured, whereby surgery is performed on at least one diseased eye. Incidence is estimated, and the four-state model is used to predict disease burden assuming different surgical strategies whilst accounting for the competing risk of death. The method is applied to data from approximately 10,000 people from a survey of visual impairment in Nigeria. PMID:24009063

  7. Research of estimation method of thermal aging embrittlement on cast austenitic stainless steel

    International Nuclear Information System (INIS)

    Thermal aging embrittlement of cast austenitic stainless steel components from the decommissioned Advanced Thermal prototype Reactor (ATR) Fugen power station has been characterized. Cast stainless steel materials were obtained from recirculation pump casing. The actual time at temperature for the materials was 138,000 h at 275°C. The Fugen serviced material show modest decrease in Charpy-impact properties and a small increase in micro-Vickers hardness in ferrite phase because of thermal aging at relatively low service temperatures. The fracture toughness prediction method (H3T model) predicts slightly lower values for Charpy-impact energy obtained from the Fugen material. The results from microstructural analysis suggest that the prediction method have the potential to provide higher accuracy by considering activation energy for embrittlement at low service temperatures. (author)

  8. RADIOLOGICAL STUDY OF FUSION OF LOWER END OF FEMUR FOR ESTIMATION OF AGE IN AGRA REGION

    Directory of Open Access Journals (Sweden)

    Anju

    2014-08-01

    Full Text Available Determination of age of an individual whether living or dead, is a vexing problem for a medical expert.1 Extensive work has been carried out on the theme in different states of India and abroad as well. However, very little work has been reported with reference to Agra population. Present work was undertaken in 200 school going children with known chronological age. In this study lower end of femur fuses at 16-17 years range i.e. average 16.5 years in females and 17-18 years range i.e. average 17.5 years in males. The epiphyseal union in females occurs earlier than male by 1 year.

  9. Estimated cases of blindness and visual impairment from neovascular age-related macular degeneration avoided in Australia by ranibizumab treatment.

    Directory of Open Access Journals (Sweden)

    Paul Mitchell

    Full Text Available Intravitreal injections of anti-vascular endothelial growth factor agents, such as ranibizumab, have significantly improved the management of neovascular age-related macular degeneration. This study used patient-level simulation modelling to estimate the number of individuals in Australia who would have been likely to avoid legal blindness or visual impairment due to neovascular age-related macular degeneration over a 2-year period as a result of intravitreal ranibizumab injections. The modelling approach used existing data for the incidence of neovascular age-related macular degeneration in Australia and outcomes from ranibizumab trials. Blindness and visual impairment were defined as visual acuity in the better-seeing eye of worse than 6/60 or 6/12, respectively. In 2010, 14,634 individuals in Australia were estimated to develop neovascular age-related macular degeneration who would be eligible for ranibizumab therapy. Without treatment, 2246 individuals would become legally blind over 2 years. Monthly 0.5 mg intravitreal ranibizumab would reduce incident blindness by 72% (95% simulation interval, 70-74%. Ranibizumab given as needed would reduce incident blindness by 68% (64-71%. Without treatment, 4846 individuals would become visually impaired over 2 years; this proportion would be reduced by 37% (34-39% with monthly intravitreal ranibizumab, and by 28% (23-33% with ranibizumab given as needed. These data suggest that intravitreal injections of ranibizumab, given either monthly or as needed, can substantially lower the number of cases of blindness and visual impairment over 2 years after the diagnosis of neovascular age-related macular degeneration.

  10. Estimation of natural radiation dose and of the age of ancient pottery by Moessbauer effect

    International Nuclear Information System (INIS)

    The effect of natural radioactive radiation on the Moessbauer Effect (ME) spectra of ancient Egyptian pottery samples of known age has been studied. An empirical relation between the intensity ratio of the non-magnetic peaks and the dose has been established. It is suggested that this relation can be used for dating of ancient potteries as a new application of the ME spectroscopy in archaeology

  11. Raman spectroscopy for highly accurate estimation of the age of refrigerated porcine muscle

    Science.gov (United States)

    Timinis, Constantinos; Pitris, Costas

    2016-03-01

    The high water content of meat, combined with all the nutrients it contains, make it vulnerable to spoilage at all stages of production and storage even when refrigerated at 5 °C. A non-destructive and in situ tool for meat sample testing, which could provide an accurate indication of the storage time of meat, would be very useful for the control of meat quality as well as for consumer safety. The proposed solution is based on Raman spectroscopy which is non-invasive and can be applied in situ. For the purposes of this project, 42 meat samples from 14 animals were obtained and three Raman spectra per sample were collected every two days for two weeks. The spectra were subsequently processed and the sample age was calculated using a set of linear differential equations. In addition, the samples were classified in categories corresponding to the age in 2-day steps (i.e., 0, 2, 4, 6, 8, 10, 12 or 14 days old), using linear discriminant analysis and cross-validation. Contrary to other studies, where the samples were simply grouped into two categories (higher or lower quality, suitable or unsuitable for human consumption, etc.), in this study, the age was predicted with a mean error of ~ 1 day (20%) or classified, in 2-day steps, with 100% accuracy. Although Raman spectroscopy has been used in the past for the analysis of meat samples, the proposed methodology has resulted in a prediction of the sample age far more accurately than any report in the literature.

  12. Estimation of Influenza Incidence by Age in the 2011/12 Seasons in Japan using SASSy

    OpenAIRE

    Ohkusa, Yasushi; Yasui, Yoshinori; Sugawara, Tamie; Okabe, Nobuhiko; Taniguchi, Kiyosu; Oishi, Kazunori

    2013-01-01

    Objective So far, it is difficult to show the incidence rate of influenza in the official sentinel surveillance in Japan. Hence we construct the system which record infectious diseases at schools, kindergartens, and nursery schools, and then can show the accurate incidence rate of influenza in children by age/grade. Introduction So as to develop more effective countermeasures against influenza, timely and precise information about influenza activity at schools, kindergartens, and nursery scho...

  13. Is the eye lens method of age estimation reliable in voles?

    Czech Academy of Sciences Publication Activity Database

    Jánová, Eva; Nesvadbová, Jiřina; Tkadlec, Emil

    2007-01-01

    Roč. 56, č. 2 (2007), s. 119-125. ISSN 0139-7893 R&D Projects: GA ČR GA206/04/2003; GA ČR(CZ) GD524/05/H536 Institutional research plan: CEZ:AV0Z60930519 Keywords : age * calibration * eye lens mass * Microtus * sexual differences Subject RIV: EG - Zoology Impact factor: 0.376, year: 2007 http://www.ivb.cz/folia/56/2/119-125_MS1084.pdf

  14. Estimation of physical and mental development of children of the senior pre-school age

    Directory of Open Access Journals (Sweden)

    Pasichnyk V.M.

    2012-08-01

    Full Text Available In this work is conducted physical and mental development of children of the senior preschool age. In the experiment, 90 children took part in the fifth year of life, among which 55 boys and 35 girls. It is noted that the children surveyed rate the physical development of the index corresponds to level - above the average. It was determined that the parameters of the functional state of preschool age children meet the age norm. It is revealed that in determining physical performance among boys set a good level, and satisfactory in girls. It is established that the results of physical fitness of boys is slightly higher than in girls. It was found that the diagnosis of the level of mental development in children fifth year of life, the average productivity and stability of attention, visual and auditory memory, visual-imagery and visual-thinking, and perception of speech correspond to the average level, and cognitive processes such as switching and distribution attention, imagination - a low level.

  15. Estimating age composition in Alpine native populations of Austropotamobius pallipes complex

    Directory of Open Access Journals (Sweden)

    Daniela Ghia

    2015-03-01

    Full Text Available Assessing the population structure and understanding growth patterns is crucial to manage freshwater resources and to solve fundamental questions concerning endangered species conservation. Austropotamobius pallipes (Lereboullet, 1858 species complex has been declining on a widespread basis in Europe, including Italy, but detailed data on population structure and growth are lacking. In four mountain streams populated by the species, water temperature data were collected by data-loggers. In July 2012, a total of 746 crayfish were collected at night and their length was measured. Females and males size distributions were analysed separately for each stream using Bhattacharya’s Method. Age was assigned to each length class. The mean values of the age classes were used to evaluate the growth rate of Von Bertalanffy, by the seasonalized equation. Up to six age classes were identified in two populations. Results show that three out of four populations are well-structured, and they confirm that A. pallipes complex is a K-selected species. We stress the need for long-term monitoring and the importance of obtained results in development of conservation plans of endangered crayfish.

  16. Geostatistical model-based estimates of Schistosomiasis prevalence among individuals aged ≤ 20 years in West Africa.

    Directory of Open Access Journals (Sweden)

    Nadine Schur

    2011-06-01

    Full Text Available BACKGROUND: Schistosomiasis is a water-based disease that is believed to affect over 200 million people with an estimated 97% of the infections concentrated in Africa. However, these statistics are largely based on population re-adjusted data originally published by Utroska and colleagues more than 20 years ago. Hence, these estimates are outdated due to large-scale preventive chemotherapy programs, improved sanitation, water resources development and management, among other reasons. For planning, coordination, and evaluation of control activities, it is essential to possess reliable schistosomiasis prevalence maps. METHODOLOGY: We analyzed survey data compiled on a newly established open-access global neglected tropical diseases database (i to create smooth empirical prevalence maps for Schistosoma mansoni and S. haematobium for individuals aged ≤ 20 years in West Africa, including Cameroon, and (ii to derive country-specific prevalence estimates. We used Bayesian geostatistical models based on environmental predictors to take into account potential clustering due to common spatially structured exposures. Prediction at unobserved locations was facilitated by joint kriging. PRINCIPAL FINDINGS: Our models revealed that 50.8 million individuals aged ≤ 20 years in West Africa are infected with either S. mansoni, or S. haematobium, or both species concurrently. The country prevalence estimates ranged between 0.5% (The Gambia and 37.1% (Liberia for S. mansoni, and between 17.6% (The Gambia and 51.6% (Sierra Leone for S. haematobium. We observed that the combined prevalence for both schistosome species is two-fold lower in Gambia than previously reported, while we found an almost two-fold higher estimate for Liberia (58.3% than reported before (30.0%. Our predictions are likely to overestimate overall country prevalence, since modeling was based on children and adolescents up to the age of 20 years who are at highest risk of infection. CONCLUSION

  17. Valley incision in the Nízké Tatry Mts. estimated based on cave sediment age

    Czech Academy of Sciences Publication Activity Database

    Kadlec, Jaroslav; Bella, P.; Granger, D. E.; Hercman, H.; Holúbek, P.; Chadima, Martin; Orvošová, M.; Pruner, Petr; Schnabl, Petr; Šifnerová, Kristýna; Šlechta, Stanislav

    [Praha] : Česká geologická společnost, 2011 - (Verner, K.; Buriánek, D.; Budil, P.). s. 44-44 ISBN 978-80-87487-00-6. [Otevřený kongres České geologické společnosti a Slovenskej geologickej spoločnosti /2./. 21.09.2011-25.09.2011, Monínec] R&D Projects: GA AV ČR IAA3013201 Institutional research plan: CEZ:AV0Z30130516 Keywords : cave sediments * magnetostratigraphy * age Subject RIV: DB - Geology ; Mineralogy http://www.geologickykongres.eu/OGK11/abstrakty/OGK11_44.pdf

  18. ESTIMATING THE AGE OF DEMARCATION OF JUVENILE AND MATURE WOOD IN Luehea divaricata Mart.

    Directory of Open Access Journals (Sweden)

    Darci Alberto Gatto

    2009-09-01

    Full Text Available This study aimed at determining the age of demarcation of juvenile and mature wood of Luehea divaricata Mart., using anatomical characteristics. Three adult trees, in good trunk, with diameter at DBH larger than 30 cm, from Encosta Superior do Nordeste do Estado do Rio Grande do Sul, were selected. Discs with thickness of 2 cm at 0.1 m of height from the base of the trunk were used. From each disc a radial ribbon 2 cm wide including the pith was removed. The initial wood of each growth ring was separated for maceration (method of Jeffrey. There were measured length and diameter of thirty fibers from each growth ring. Demarcation of the two types of wood was defined by the radial variation (pith-bark of the anatomical characteristics (length, diameter, width of the lumen and wall thickness of fibers, using simple linear regression. Results indicate that fiber length is the best characteristic, while fiber diameter, lumen width and wall thickness were considered inadequate for demarcation. The age of demarcation of juvenile and mature wood of Luehea divaricata was defined as 21 years-old, approximately.

  19. Asteroseismology of red giants: from analysing light curves to estimating ages

    CERN Document Server

    Davies, G R

    2016-01-01

    Asteroseismology has started to provide constraints on stellar properties that will be essential to accurately reconstruct the history of the Milky Way. Here we look at the information content in data sets representing current and future space missions (CoRoT, Kepler, K2, TESS, and PLATO) for red giant stars. We describe techniques for extracting the information in the frequency power spectrum and apply these techniques to {\\it Kepler} data sets of different observing length to represent the different space missions. We demonstrate that for KIC 12008916, a low-luminosity red giant branch star, we can extract useful information from all data sets, and for all but the shortest data set we obtain good constraint on the g-mode period spacing and core rotation rates. We discuss how the high precision in these parameters will constrain the stellar properties of stellar radius, distance, mass and age. We show that high precision can be achieved in mass and hence age when values of the g-mode period spacing are avail...

  20. OCCLUSION VERIFICATION IN FACE DETECTION AND AGE ESTIMATION USING LOCAL BINARY PATTERN AND DTOD CLASSIFIER USING MORPH DATASET

    Directory of Open Access Journals (Sweden)

    P.Karthigayani

    2013-02-01

    Full Text Available The purpose of this research work is focused on occlusion conditions in the face like wearing sunglasses and scarf in the eyes and mouth positions of the facial image. The proposed work has three stages.The first stage was based on Decision Tree Induction C5.0 algorithm to classify the occluded part and non occluded part in the facial image. The Second stage was face verification using Local Binary Pattern method. The third stage carried out the estimation of human age using Back Propagation Neural Network. The results of the proposed work having high accuracy of identification of face using decision tree and local binary pattern method using non occluded part of the facial image as the feature. Also the age can be identified using Back Propagation Neural Network algorithm using winkles as a feature and the gender can be classified using the Posteriori and Priori probability values. Compared to the existing work the occluded part was efficiently classified using Decision Tree method and the age can be classified into minimum age intervals like 0-2, 3-5, 6-9 instead of 0-9 in the existing work.

  1. The Impact of Gender, Age and Tissues in vitro on Estimating Postmortem Interval by FTIR Spectroscopy%The Impact of Gender,Age and Tissues in vitro on Estimating Postmortem Interval by FTIR Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    XUAN Miao-gen; FU Gao-wen; LIU Feng; MENG Hao-tian; WANG Zhen-yuan

    2013-01-01

    To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval (PMI) by the Fourier transform infrared (FTIR) spectrometer in animal experiments.SD rats were classified into male and female groups,different age groups (21-day,42-day and 63-day group),and tissues in vitro and in vivo groups.The rats were sacrificed by cervical dislocation,whose bodies were kept in a controlled environmental chamber set at (20±2)℃ and 50% humidity.The liver,kidney,spleen,myocardium,brain,lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem.With the change of PMI,no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points.All the experimental groups showed no significant changes when compared with the controls.The gender,age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.

  2. Longevity of Atlantic Sharpnose Sharks Rhizoprionodon terraenovae and Blacknose Sharks Carcharhinus acronotus in the western North Atlantic Ocean based on tag-recapture data and direct age estimates.

    Science.gov (United States)

    Frazier, Bryan S; Driggers Iii, William B; Ulrich, Glenn F

    2014-01-01

    Longevity of Rhizoprionodon terraenovae and Carcharhinus acronotus in the western North Atlantic Ocean was examined using direct age estimates from vertebral sections and tag-recapture data. Time-at-liberty ranged from 7.7-14.0 years (mean =10.1) for R. terraenovae and 10.9-12.8 years (mean =11.9) for C. acronotus. Maximum estimated longevity was determined to be 19.8 years through tag-recapture data and 18.5 years from direct age estimates for R. terraenovae and 22.8 years through tag-recapture data and 20.5 years through direct age estimates for C. acronotus. These longevity estimates represent a large increase over previous estimates and may have significant effects on analyses that depend on longevity including lifetime fecundity, mortality rates, demographic analyses and stock assessments. PMID:25685321

  3. Functional Time Series Models to Estimate Future Age-Specific Breast Cancer Incidence Rates for Women in Karachi, Pakistan

    Institute of Scientific and Technical Information of China (English)

    Farah Yasmeen[1; Sidra Zaheer[2

    2014-01-01

    Background: Breast cancer is the most common female cancer in Pakistan. The incidence of breast cancer in Pakistan is about 2.5 times higher than that in the neighboring countries India and Iran. In Karachi, the most populated city of Pakistan, the age-standardized rate of breast cancer was 69.1 per 100,000 women during 1998-2002, which is the highest recorded rate in Asia. The carcinoma of breast in Pakistan is an enormous public health concern. In this study, we examined the recent trends of breast cancer incidence rates among the women in Karachi. Methods: We obtained the secondary data of breast cancer incidence from various hospitals. They included Jinnah Hospital, KIRAN (Karachi Institute of Radiotherapy and Nuclear Medicine), and Civil hospital, where the data were available for the years 2004-2011. A total of 5331 new cases of female breast cancer were registered during this period. We analyzed the data in 5-year age groups 15-19, 20-24, 25-29, 30-34, 35-39, 40-44, 45-49, 50-54, 55-59, 60-64, 65-69, 70-74, 75+. Nonparametric smoothing were used to obtained age-specific incidence curves, and then the curves are decomposed using principal components analysis to fit FTS (functional time series) model. We then used exponential smoothing statspace models to estimate the forecasts of incidence curve and construct prediction intervals. Results: The breast cancer incidence rates in Karachi increased with age for all available years. The rates increased monotonically and are relatively sharp with the age from 15 years to 50 years and then they show variability after the age of 50 years. 10-year forecasts for the female breast cancer incidence rates in Karachi show that the future rates are expected to remain stable for the age-groups 15-50 years, but they will increase for the females of 50-years and over. Hence in future, the newly diagnosed breast cancer cases in the older women in Karachi are expected to increase. Conclusion: Prediction of age

  4. Growth process in an elephant tusk: Age estimations based on temporal variations in bomb-radiocarbon content

    Science.gov (United States)

    Nakamura, Toshio; Koike, Hiroko; Aizawa, Jun; Okuno, Mitsuru

    2015-10-01

    In this study, 14C analysis by accelerator mass spectrometry (AMS) was applied to age estimation based on temporal variations in bomb-produced-14C contents of a full elephant tusk registered at Kyushu University. The tusk measured 175 cm long and 13.8 cm in diameter at the root. Thirty tusk-fragment samples were used for 14C analysis with AMS to estimate the formation ages of different positions according to catalogued global 14C contents (F14C). The F14C value of the tip of the tusk suggested that the elephant was born around 1980, while that of the root suggested death around 1994, a lifespan of at least 14 years, rather shorter period than the average lifetime of an elephant (ca. 80 years). In addition, the F14C values of fragments collected along a cross-sectional line suggested that the outer part of the tusk formed first with inner parts being deposited gradually with growth.

  5. Anatomy and age estimation of an early blue whale (Balaenoptera musculus) fetus.

    Science.gov (United States)

    Roston, Rachel A; Lickorish, David; Buchholtz, Emily A

    2013-04-01

    The external anatomy of a 130-mm blue whale fetus (Balaenoptera musculus) is described, and its internal anatomy is reconstructed noninvasively from microCT scans. The specimen lies developmentally at the junction of the embryonic and fetal periods. Similarly to the embryos of many odontocetes, it lacks a caudal fluke and dorsal fin, but it also exhibits an elongated rostrum, resorbed umbilical hernia, partially exposed cornea, and spatial separation of the anus and genitalia seen in early odontocete fetuses. Dermal ossification of the cranial bones has begun, but the endochondral skeleton is completely cartilaginous. The shape and position of the maxilla suggest that the earliest stages of anterior skull telescoping have begun, but there is no indication of occipital overlap posteriorly. The nasopharynx, larynx, and heart already display the distinctive morphology characteristic of Balaenoptera. This study develops a model of body length changes during blue whale development by integrating the large International Whaling Statistics (IWS) database, historical observations of blue whale migration and reproduction, and descriptions of fetal growth trends in other mammals. The model predicts an age of 65 days postconception for the specimen. The early developmental milestones of Balaenoptera mirror those of the odontocete Stenella to a remarkable extent, but the first appearance of the caudal fluke and dorsal fin are delayed relative to other morphological transitions. The accelerated prenatal growth characteristic of Balaenoptera occurs during fetal, not embryonic, development. PMID:23447333

  6. Simultaneous estimation of effects of gender, age and walking speed on kinematic gait data.

    Science.gov (United States)

    Røislien, Jo; Skare, Øivind; Gustavsen, Marit; Broch, Nana L; Rennie, Linda; Opheim, Arve

    2009-11-01

    Analysis of variations in normal gait has received considerable attention over the last years. However, most such analyses are carried out on one explanatory variable at a time, and adjustments for other possibly influencing factors are often done using ad hoc methods. As a result, it can be difficult to know whether observed effects are actually a result of the variable under study. We wanted to simultaneously statistically test the effect of gender, age and walking speed on gait in a normal population, while also properly adjusting for the possibly confounding effects of body height and weight. Since point-by-point analysis does not take into account the time dependency in the data, we turned to functional data analysis (FDA). In FDA the whole gait curve is represented not by a set of points, but by a mathematical function spanning the whole gait cycle. We performed several multiple functional regression analyses, and the results indicate that walking speed is the main factor influencing gait in the reference material at our motion analysis laboratory. This effect is also largely unaffected by the presence of other variables in the model. A gender effect was also apparent in several planes and joints, but this effect was often more outspoken in the multiple than in the univariate regression analyses, highlighting the importance of adjusting for confounders like body height and weight. PMID:19665379

  7. Estimating the Burden of Leptospirosis among Febrile Subjects Aged below 20 Years in Kampong Cham Communities, Cambodia, 2007-2009.

    Directory of Open Access Journals (Sweden)

    Sopheak Hem

    Full Text Available Leptospirosis is an emerging but neglected public health challenge in the Asia/Pacific Region with an annual incidence estimated at 10-100 per 100,000 population. No accurate data, however, are available for at-risk rural Cambodian communities.We conducted anonymous, unlinked testing for IgM antibodies to Leptospira spp. on paired sera of Cambodian patients <20 years of age between 2007-2009 collected through active, community-based surveillance for febrile illnesses in a convenience sample of 27 rural and semi-rural villages in four districts of Kampong Cham province, Cambodia. Leptospirosis testing was done on paired serological samples negative for Dengue, Japanese encephalitis and Chikungunya viruses after random selection. Convalescent samples found positive while initial samples were negative were considered as proof of acute infection. We then applied a mathematical model to estimate the risk of fever caused by leptospirosis, dengue or other causes in rural Cambodia.A total of 630 samples are coming from a randomly selected subset of 2358 samples. IgM positive were found on the convalescent serum sample, among which 100 (15.8% samples were IgM negative on an earlier sample. Seventeen of these 100 seroconversions were confirmed using a Microagglutination Test. We estimated the probability of having a fever due to leptospirosis at 1. 03% (95% Credible Interval CI: 0. 95%-1. 22% per semester. In comparison, this probability was 2. 61% (95% CI: 2. 55%, 2. 83% for dengue and 17. 65% (95% CI: 17. 49%, 18. 08% for other causes.Our data from febrile cases aged below 20 years suggest that the burden of leptospirosis is high in rural Cambodian communities. This is especially true during the rainy season, even in the absence of identified epidemics.

  8. Age estimation of juvenile European hake Merluccius merluccius based on otolith microstructure analysis: a slow or fast growth pattern?

    Science.gov (United States)

    Pattoura, P; Lefkaditou, E; Megalofonou, P

    2015-03-01

    The main goal of this study was to examine otolith microstructure and to estimate the age and growth of European hake Merluccius merluccius from the eastern Mediterranean Sea. One hundred and twenty-nine specimens ranging from 102 to 438 mm in total length (LT ) were used. Age estimations were based on the study of the otolith microstructure, which was revealed after grinding both frontal sides of otoliths. The enumerations of the daily growth increments (DGI) as well as their width (WDGI ) measurements were made on calibrated digital images. The number of DGI in otoliths ranged between 163 and 717. Four phases in the WDGI evolution were distinguished: (1) larval-juvenile pelagic phase, with an increasing trend in WDGI up to the 60th DGI, (2) settlement phase, with a short-term deceleration in WDGI between the 61st and 150th DGI, (3) juvenile demersal phase, characterized by a stabilization of WDGI from 151st to 400th DGI and (4) adult phase, with a decreasing trend in WDGI after the 400th DGI. Age, sex and month of formation were found to affect the WDGI in all phases, with the exception of age at the juvenile demersal phase. The power curve with intercept model described best the relationship of M. merluccius LT with age (TDGI ), according to Akaike criteria, revealing differences in growth between females [LT = 65 · 36(TDGI )(0 · 40) - 388 · 55] and males [LT = 69 · 32(TDGI )(0 · 37) - 352 · 88] for the sizes examined. The mean daily growth rates were 0·61 mm day(-1) for females and 0·52 mm day(-1) for males, resulting in an LT of 283 and 265 mm at the end of their first year of life. In comparison with previous studies on the Mediterranean Sea, the results of this study showed a greater growth rate, similar to results from tagging experiments and otolith microstructure analyses for M. merluccius in other geographic areas. PMID:25545134

  9. New data on age of subalkaline magmatism on the eastern margin of the east european paleocontinent and the estimation of the early paleozoic longitudinal rift opening velocity

    International Nuclear Information System (INIS)

    The age of comendites from the Malinovsky complex of Northern Ural was determined by U-Pb (SHRIMP II) zircon dating of trachyrhyilites. The isotopic age, 476.2 ± 2.7 m.a., can be considered as the most reliable estimate of rock formation time for the complex studied. Based on the isotopic geochronological data obtained, the velocity of longitudinal opening (from north to south) of the early paleozoic rift system was estimated to be 10 cm per year

  10. ASSET (Age/Sex Standardised Estimates of Treatment: a research model to improve the governance of prescribing funds in Italy.

    Directory of Open Access Journals (Sweden)

    Giampiero Favato

    Full Text Available BACKGROUND: The primary objective of this study was to make the first step in the modelling of pharmaceutical demand in Italy, by deriving a weighted capitation model to account for demographic differences among general practices. The experimental model was called ASSET (Age/Sex Standardised Estimates of Treatment. METHODS AND MAJOR FINDINGS: Individual prescription costs and demographic data referred to 3,175,691 Italian subjects and were collected directly from three Regional Health Authorities over the 12-month period between October 2004 and September 2005. The mean annual prescription cost per individual was similar for males (196.13 euro and females (195.12 euro. After 65 years of age, the mean prescribing costs for males were significantly higher than females. On average, costs for a 75-year-old subject would be 12 times the costs for a 25-34 year-old subject if male, 8 times if female. Subjects over 65 years of age (22% of total population accounted for 56% of total prescribing costs. The weightings explained approximately 90% of the evolution of total prescribing costs, in spite of the pricing and reimbursement turbulences affecting Italy in the 2000-2005 period. The ASSET weightings were able to explain only about 25% of the variation in prescribing costs among individuals. CONCLUSIONS: If mainly idiosyncratic prescribing by general practitioners causes the unexplained variations, the introduction of capitation-based budgets would gradually move practices with high prescribing costs towards the national average. It is also possible, though, that the unexplained individual variation in prescribing costs is the result of differences in the clinical characteristics or socio-economic conditions of practice populations. If this is the case, capitation-based budgets may lead to unfair distribution of resources. The ASSET age/sex weightings should be used as a guide, not as the ultimate determinant, for an equitable allocation of prescribing

  11. A statistical method for estimating rates of soil development and ages of geologic deposits: A design for soil-chronosequence studies

    Science.gov (United States)

    Switzer, P.; Harden, J.W.; Mark, R.K.

    1988-01-01

    A statistical method for estimating rates of soil development in a given region based on calibration from a series of dated soils is used to estimate ages of soils in the same region that are not dated directly. The method is designed specifically to account for sampling procedures and uncertainties that are inherent in soil studies. Soil variation and measurement error, uncertainties in calibration dates and their relation to the age of the soil, and the limited number of dated soils are all considered. Maximum likelihood (ML) is employed to estimate a parametric linear calibration curve, relating soil development to time or age on suitably transformed scales. Soil variation on a geomorphic surface of a certain age is characterized by replicate sampling of soils on each surface; such variation is assumed to have a Gaussian distribution. The age of a geomorphic surface is described by older and younger bounds. This technique allows age uncertainty to be characterized by either a Gaussian distribution or by a triangular distribution using minimum, best-estimate, and maximum ages. The calibration curve is taken to be linear after suitable (in certain cases logarithmic) transformations, if required, of the soil parameter and age variables. Soil variability, measurement error, and departures from linearity are described in a combined fashion using Gaussian distributions with variances particular to each sampled geomorphic surface and the number of sample replicates. Uncertainty in age of a geomorphic surface used for calibration is described using three parameters by one of two methods. In the first method, upper and lower ages are specified together with a coverage probability; this specification is converted to a Gaussian distribution with the appropriate mean and variance. In the second method, "absolute" older and younger ages are specified together with a most probable age; this specification is converted to an asymmetric triangular distribution with mode at the

  12. Clinical validation of a genetic model to estimate the risk of developing choroidal neovascular age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Hageman Gregory S

    2011-07-01

    Full Text Available Abstract Predictive tests for estimating the risk of developing late-stage neovascular age-related macular degeneration (AMD are subject to unique challenges. AMD prevalence increases with age, clinical phenotypes are heterogeneous and control collections are prone to high false-negative rates, as many control subjects are likely to develop disease with advancing age. Risk prediction tests have been presented previously, using up to ten genetic markers and a range of self-reported non-genetic variables such as body mass index (BMI and smoking history. In order to maximise the accuracy of prediction for mainstream genetic testing, we sought to derive a test comparable in performance to earlier testing models but based purely on genetic markers, which are static through life and not subject to misreporting. We report a multicentre assessment of a larger panel of single nucleotide polymorphisms (SNPs than previously analysed, to improve further the classification performance of a predictive test to estimate the risk of developing choroidal neovascular (CNV disease. We developed a predictive model based solely on genetic markers and avoided inclusion of self-reported variables (eg smoking history or non-static factors (BMI, education status that might otherwise introduce inaccuracies in calculating individual risk estimates. We describe the performance of a test panel comprising 13 SNPs genotyped across a consolidated collection of four patient cohorts obtained from academic centres deemed appropriate for pooling. We report on predictive effect sizes and their classification performance. By incorporating multiple cohorts of homogeneous ethnic origin, we obtained >80 per cent power to detect differences in genetic variants observed between cases and controls. We focused our study on CNV, a subtype of advanced AMD associated with a severe and potentially treatable form of the disease. Lastly, we followed a two-stage strategy involving both test model

  13. A fundamental study on the dynamics of multiple biomarkers in mouse excisional wounds for wound age estimation.

    Science.gov (United States)

    Wang, Lin-Lin; Zhao, Rui; Liu, Chang-Sheng; Liu, Min; Li, Shan-Shan; Li, Jiao-Yong; Jiang, Shu-Kun; Zhang, Miao; Tian, Zhi-Ling; Wang, Meng; Zhang, Meng-Zhou; Guan, Da-Wei

    2016-04-01

    Wound age estimation is a classic but still modern theme in forensic practice. More experiments on different types of wound are needed to further improve its accuracy. In this study, mouse skin excisional wounds were created to simulate dermal defective injury. The neutrophil and macrophage infiltration, fibroblast and fibrocyte accumulation as well as their myofibroblastic transformation were examined. In addition, some wound healing-related molecules, including IL-1β, IL-6, TNF-α, IFN-γ, MCP-1, CXCL12, VEGF-A, EGF, KGF, pro-col Iα2 and pro-col IIIα1, were quantified by Western blotting and real-time quantitative PCR. Neutrophils and macrophages profoundly infiltrated in the wound at 12 h-1 d and 3 d-10 d respectively. Fibroblasts and fibrocytes accumulated in the wound from 3 d, and transformed into contractile myofibroblasts from 5 d post injury. The transformation ratios of fibroblasts and fibrocytes were highest at 7 d-10 d and 10 d respectively (over 50%). MCP-1 and CXCL12 increased from 12 h to 5 d, and IL-1β, TNF-α and pro-col IIIα1 up to 7 d. IL-6 and VEGF-A increased from 12 h to 1 d-10 d. Pro-col Iα2 increased from 7 d to 21 d. IFN-γ decreased from 12 h to 10 d. By comprehensive analysis of these factors from the perspective of morphometrics, protein and gene expressions, this study provided us with fundamental information for wound age estimation, especially in the wounds with full-thickness defection. PMID:26889946

  14. A new model for the estimation of time of death from vitreous potassium levels corrected for age and temperature.

    Science.gov (United States)

    Zilg, B; Bernard, S; Alkass, K; Berg, S; Druid, H

    2015-09-01

    Analysis of potassium concentration in the vitreous fluid of the eye is frequently used by forensic pathologists to estimate the postmortem interval (PMI), particularly when other methods commonly used in the early phase of an investigation can no longer be applied. The postmortem rise in vitreous potassium has been recognized for several decades and is readily explained by a diffusion of potassium from surrounding cells into the vitreous fluid. However, there is no consensus regarding the mathematical equation that best describes this increase. The existing models assume a linear increase, but different slopes and starting points have been proposed. In this study, vitreous potassium levels, and a number of factors that may influence these levels, were examined in 462 cases with known postmortem intervals that ranged from 2h to 17 days. We found that the postmortem rise in potassium followed a non-linear curve and that decedent age and ambient temperature influenced the variability by 16% and 5%, respectively. A long duration of agony and a high alcohol level at the time of death contributed less than 1% variability, and evaluation of additional possible factors revealed no detectable impact on the rise of vitreous potassium. Two equations were subsequently generated, one that represents the best fit of the potassium concentrations alone, and a second that represents potassium concentrations with correction for decedent age and/or ambient temperature. The former was associated with narrow confidence intervals in the early postmortem phase, but the intervals gradually increased with longer PMIs. For the latter equation, the confidence intervals were reduced at all PMIs. Therefore, the model that best describes the observed postmortem rise in vitreous potassium levels includes potassium concentration, decedent age, and ambient temperature. Furthermore, the precision of these equations, particularly for long PMIs, is expected to gradually improve by adjusting the

  15. Estimating the Burden of Leptospirosis among Febrile Subjects Aged below 20 Years in Kampong Cham Communities, Cambodia, 2007-2009

    Science.gov (United States)

    Hem, Sopheak; Ly, Sowath; Votsi, Irene; Vogt, Florian; Asgari, Nima; Buchy, Philippe; Heng, Seiha; Picardeau, Mathieu; Sok, Touch; Ly, Sovann; Huy, Rekol; Guillard, Bertrand; Cauchemez, Simon; Tarantola, Arnaud

    2016-01-01

    Background Leptospirosis is an emerging but neglected public health challenge in the Asia/Pacific Region with an annual incidence estimated at 10–100 per 100,000 population. No accurate data, however, are available for at-risk rural Cambodian communities. Method We conducted anonymous, unlinked testing for IgM antibodies to Leptospira spp. on paired sera of Cambodian patients Leptospirosis testing was done on paired serological samples negative for Dengue, Japanese encephalitis and Chikungunya viruses after random selection. Convalescent samples found positive while initial samples were negative were considered as proof of acute infection. We then applied a mathematical model to estimate the risk of fever caused by leptospirosis, dengue or other causes in rural Cambodia. Results A total of 630 samples are coming from a randomly selected subset of 2358 samples. IgM positive were found on the convalescent serum sample, among which 100 (15.8%) samples were IgM negative on an earlier sample. Seventeen of these 100 seroconversions were confirmed using a Microagglutination Test. We estimated the probability of having a fever due to leptospirosis at 1. 03% (95% Credible Interval CI: 0. 95%–1. 22%) per semester. In comparison, this probability was 2. 61% (95% CI: 2. 55%, 2. 83%) for dengue and 17. 65% (95% CI: 17. 49%, 18. 08%) for other causes. Conclusion Our data from febrile cases aged below 20 years suggest that the burden of leptospirosis is high in rural Cambodian communities. This is especially true during the rainy season, even in the absence of identified epidemics. PMID:27043016

  16. Age estimation based on bone length using 12 regression models of left hand X-ray images for Asian children below 19 years old.

    Science.gov (United States)

    Darmawan, M F; Yusuf, Suhaila M; Abdul Kadir, M R; Haron, H

    2015-03-01

    Age estimation was used in forensic anthropology to help in the identification of individual remains and living person. However, the estimation methods tend to be unique and applicable only to a certain population. This paper analyzed age estimation using twelve regression models carried out on X-ray images of the left hand taken from an Asian data set for subjects under the age of 19. All the nineteen bones of the left hand were measured using free image software and the statistical analysis were performed using SPSS. There are two methods to determine age in this study which are single bone method and all bones method. For single bone method, S-curve regression model was found to have the highest R-square value using second metacarpal for males, and third proximal phalanx for females. For age estimation using single bone, fifth metacarpal from males and fifth proximal phalanx from females can be used due to the lowest mean square error (MSE) value. To conclude, multiple linear regressions is the best techniques for age estimation in cases where all bones are available, but if not, S-curve regression can be used using single bone method. PMID:25456051

  17. Preterm or not--an evaluation of estimates of gestational age in a cohort of women from Rural Papua New Guinea.

    Directory of Open Access Journals (Sweden)

    Stephan Karl

    Full Text Available Knowledge of accurate gestational age is required for comprehensive pregnancy care and is an essential component of research evaluating causes of preterm birth. In industrialised countries gestational age is determined with the help of fetal biometry in early pregnancy. Lack of ultrasound and late presentation to antenatal clinic limits this practice in low-resource settings. Instead, clinical estimators of gestational age are used, but their accuracy remains a matter of debate.In a cohort of 688 singleton pregnancies from rural Papua New Guinea, delivery gestational age was calculated from Ballard score, last menstrual period, symphysis-pubis fundal height at first visit and quickening as well as mid- and late pregnancy fetal biometry. Published models using sequential fundal height measurements and corrected last menstrual period to estimate gestational age were also tested. Novel linear models that combined clinical measurements for gestational age estimation were developed. Predictions were compared with the reference early pregnancy ultrasound (<25 gestational weeks using correlation, regression and Bland-Altman analyses and ranked for their capability to predict preterm birth using the harmonic mean of recall and precision (F-measure.Average bias between reference ultrasound and clinical methods ranged from 0-11 days (95% confidence levels: 14-42 days. Preterm birth was best predicted by mid-pregnancy ultrasound (F-measure: 0.72, and neuromuscular Ballard score provided the least reliable preterm birth prediction (F-measure: 0.17. The best clinical methods to predict gestational age and preterm birth were last menstrual period and fundal height (F-measures 0.35. A linear model combining both measures improved prediction of preterm birth (F-measure: 0.58.Estimation of gestational age without ultrasound is prone to significant error. In the absence of ultrasound facilities, last menstrual period and fundal height are among the more reliable

  18. Intra- and inter-observer reproducibility study of gestational age estimation using three common foetal biometric parameters: Experienced versus inexperienced sonographer

    International Nuclear Information System (INIS)

    Aim: To assess reproducibility of estimating gestational age (GA) of foetus using femur length (FL), biparietal diameter (BPD) and abdominal circumference (AC) within experienced and inexperienced sonographers and between the two. Patients and methods: Two sets of GA estimates each were obtained for FL, BPD and AC by the two observers in 20 normal singleton foetuses. The first estimates for the three biometric parameters were made by the experienced sonographer. Subsequently, the inexperienced sonographer, blind to the estimates of the first observer obtained his own estimates for the same biometric parameters. After a time interval of ten minutes the process was repeated for the second set of GA estimates. All the gestational age estimates were made following standard protocol. Statistical analysis was performed by Pearson's and intraclass correlations, coefficient of variation and Bland–Altman plots. Statistical inferences were drawn at p < 0.05. Results: The Pearson's and intraclass correlations of between GA estimates within and between both observers from measurement of FL, BPD and AC were very high and statistically significant (p < 0.05). Coefficient of variation for duplicate measurements for GA estimates within observers and between observers were quite negligible. Between observers, the first and second GA estimates from FL measurements showed the least variation. Estimates from BPD and AC measurements showed greater degree of variation between the observers. Conclusion: Reproducibility of GA estimation using FL, BPD and AC within experienced and inexperienced sonographers and between the two was excellent. Therefore, a fresh Nigerian radiography graduate with adequate exposure in obstetric ultrasound can correctly determine the gestational age of foetus in routine obstetric ultrasound without supervision

  19. Age estimation on the stricture of pulp cavity of the mandibular first premolar by 3D micro-focus X-CT

    International Nuclear Information System (INIS)

    To know the effect of aging on pulp cavity volumes, 40 mandibular first premolars obtained from 21-75 years old persons and stored in authors' laboratory were subjected to 3D micro-focus X-CT (SMX-130CT-SV, Shimadzu Works) to determine the volume, and ratios to the root canal pulp volume of the crown (C), cervical 1/3 (R1), central (R2) and apical 1/3 (R3) pulp volumes were calculated. In all ages examined, the ratios were in the order of R1>R2>C>R3, and were decreased by aging with exception for R1. Changes in R1 were significant in thirties to fifties and in R2, in twenties to thirties. Multiple regression analysis for age estimation gave the multiple correlation coefficient of 0.82 and coefficient of determination of 0.67, and the item that the partial correlation coefficient was significantly high was R1 (RPVR1) alone. Regression analysis using RPVR1 as a variable gave the multiple correlation coefficient of 0.81 between actual and estimated ages and estimated error (within ±6 years) by the regression was 42.5%. The method was thus found usefully applied for age estimation in forensic judgment. (S.I.)

  20. Estimation of usual intake and food sources of choline and betaine in New Zealand reproductive age women.

    Science.gov (United States)

    Mygind, Vanessa L; Evans, Sophie E; Peddie, Meredith C; Miller, Jody C; Houghton, Lisa A

    2013-01-01

    Recently, choline has been associated with neurodevelopment, cognitive function and neural tube defect incidence. However, data on usual intakes are limited, and estimates of dietary intakes of choline and its metabolite betaine, are not available for New Zealanders. The objective of the present study was to determine usual intake and food sources of choline and betaine in a group of New Zealand reproductive age women. Dietary intake data were collected from a sample of 125 women, aged 18-40 years, by means of a 3-day weighed food record, and usual choline and betaine intake distributions were determined. The mean (SD) daily intakes of choline and betaine were 316 (66) mg and 178 (66) mg, respectively. The total choline intake relative to energy intake and body weight was 0.18 mg/kcal and 5.1 mg/kg, respectively. Only 16% of participants met or exceeded the Adequate Intake (AI) for adult women of 425 mg of choline. The top five major food contributors of choline were eggs, red meat, milk, bread and chicken; and of betaine were bread, breakfast cereal, pasta, grains and root vegetables (carrots, parsnips, beetroot, swedes). Our findings contribute towards the recent emergence of published reports on the range of dietary choline and betaine intakes consumed by free-living populations. In our sample of New Zealand women, few participants were meeting or exceeding the AI level. Given recent epidemiological evidence suggesting health benefits of increased choline and betaine intakes, recommendations should be made to encourage the consumption of choline and betaine-rich foods. PMID:23635379

  1. Estimating Gestational Age in Late Presenters to Antenatal Care in a Resource-Limited Setting on the Thai-Myanmar Border.

    Directory of Open Access Journals (Sweden)

    Kerryn A Moore

    Full Text Available Estimating gestational age in resource-limited settings is prone to considerable inaccuracy because crown-rump length measured by ultrasound before 14 weeks gestation, the recommended method for estimating gestational age, is often unavailable. Judgements regarding provision of appropriate obstetric and neonatal care are dependent on accurate estimation of gestational age. We determined the accuracy of the Dubowitz Gestational Age Assessment, a population-specific symphysis-fundal height formula, and ultrasound biometry performed between 16 and 40 weeks gestation in estimating gestational age using pre-existing data from antenatal clinics of the Shoklo Malaria Research Unit on the Thai-Myanmar border, where malaria is endemic. Two cohorts of women who gave birth to live singletons were analysed: 1 250 women who attended antenatal care between July 2001 and May 2006 and had both ultrasound crown-rump length (reference and a Dubowitz Gestational Age Assessment; 2 975 women attending antenatal care between April 2007 and October 2010 who had ultrasound crown-rump length, symphysis-fundal measurements, and an additional study ultrasound (biparietal diameter and head circumference randomly scheduled between 16 and 40 weeks gestation. Mean difference in estimated newborn gestational age between methods and 95% limits of agreement (LOA were determined from linear mixed-effects models. The Dubowitz method and the symphysis-fundal height formula performed well in term newborns, but overestimated gestational age of preterms by 2.57 weeks (95% LOA: 0.49, 4.65 and 3.94 weeks (95% LOA: 2.50, 5.38, respectively. Biparietal diameter overestimated gestational age by 0.83 weeks (95% LOA: -0.93, 2.58. Head circumference underestimated gestational age by 0.39 weeks (95% LOA: -2.60, 1.82, especially if measured after 24 weeks gestation. The results of this study can be used to quantify biases associated with alternative methods for estimating gestational age in the

  2. National and regional estimates of term and preterm babies born small for gestational age in 138 low-income and middle-income countries in 2010

    DEFF Research Database (Denmark)

    Lee, Anne C C; Katz, Joanne; Blencowe, Hannah;

    2013-01-01

    BACKGROUND: National estimates for the numbers of babies born small for gestational age and the comorbidity with preterm birth are unavailable. We aimed to estimate the prevalence of term and preterm babies born small for gestational age (term-SGA and preterm-SGA), and the relation to low birthwe...... increase survival and reduce disability, stunting, and non-communicable diseases. FUNDING: Bill & Melinda Gates Foundation by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group (CHERG)....

  3. Criteria of estimation of positive health level in the long-term process of the health training of women of senior age.

    Directory of Open Access Journals (Sweden)

    Prusik Katerina

    2011-09-01

    Full Text Available In the article materials of the three-year looking are utillized after the state of positive health of group of women in age 50-80 years. The method of statistical ground of adequate control indexes is shown for the estimation of bodily condition of inspected. The use of high-quality criteria is offered for the estimation of efficiency of physical exercises on the Norwegian method of walking with sticks.

  4. COMBINING LIDAR ESTIMATES OF BIOMASS AND LANDSAT ESTIMATES OF STAND AGE FOR SPATIALLY EXTENSIVE VALIDATION OF MODELED FOREST PRODUCTIVITY. (R828309)

    Science.gov (United States)

    Extensive estimates of forest productivity are required to understand the relationships between shifting land use, changing climate and carbon storage and fluxes. Aboveground net primary production of wood (NPPAw) is a major component of total NPP and...

  5. Does Net Endogenous Acid Production (NEAP) Estimated from Diet Vary with Age and Body Mass Index (BMI) in Men and Women?

    Science.gov (United States)

    Acid-base balance may influence skeletal health in humans. Animal and plant-based foods provide acid and alkaline precursors respectively, which contribute to net acid-base balance. Algorithms for estimating NEAP from dietary protein and potassium levels have been published, but it is unknown if age...

  6. Estimation of the age-specific per-contact probability of Ebola virus transmission in Liberia using agent-based simulations

    Science.gov (United States)

    Siettos, Constantinos I.; Anastassopoulou, Cleo; Russo, Lucia; Grigoras, Christos; Mylonakis, Eleftherios

    2016-06-01

    Based on multiscale agent-based computations we estimated the per-contact probability of transmission by age of the Ebola virus disease (EVD) that swept through Liberia from May 2014 to March 2015. For the approximation of the epidemic dynamics we have developed a detailed agent-based model with small-world interactions between individuals categorized by age. For the estimation of the structure of the evolving contact network as well as the per-contact transmission probabilities by age group we exploited the so called Equation-Free framework. Model parameters were fitted to official case counts reported by the World Health Organization (WHO) as well as to recently published data of key epidemiological variables, such as the mean time to death, recovery and the case fatality rate.

  7. Digital radiographic evaluation of mandibular third molar for age estimation in young adults and adolescents of South Indian population using modified Demirjian′s method

    Directory of Open Access Journals (Sweden)

    Rezwana Begum Mohammed

    2014-01-01

    Full Text Available In recent years, it has become increasingly important to determine the age of living people for a variety of reasons, including identifying criminal and legal responsibility and for many other social events such as birth certificate, marriage, beginning a job, joining the army and retirement. Objectives: The aim of this study was to assess the developmental stages of mandibular third molar for estimation of dental age (DA in different age groups and to evaluate the possible correlation between DA and chronological age (CA in South Indian population. Materials and Methods: Digital orthopantomography of 330 subjects (165 males, 165 females who fit the study and the criteria were obtained. Assessment of mandibular third molar development was performed using Demirjian et al., modified method and DA was assessed using tooth specific stages. Results and Discussion: The present study showed a significant correlation between DA and CA in both males and females. Third molar development commenced around 9 years and root completion takes place around 18.9 years in males and in females 9 years and 18.6 years respectively. Demirjian modified method underestimated the mean age of males by 0.8 years and females by 0.5 years and also showed that females mature earlier than males in selected population. Conclusion: Digital radiographic assessment of mandibular third molar development can be used to generate mean DA using Demirjian modified method and also the estimated age range for an individual of unknown CA. Since the Demirjian method is based on French-Canadian population, to enhance the accuracy of forensic age estimates based on third molar development, the use of population-specific standards is recommended.

  8. Age- and gender-specific estimates of cumulative CT dose over 5 years using real radiation dose tracking data in children

    International Nuclear Information System (INIS)

    It is necessary to develop a mechanism to estimate and analyze cumulative radiation risks from multiple CT exams in various clinical scenarios in children. To identify major contributors to high cumulative CT dose estimates using actual dose-length product values collected for 5 years in children. Between August 2006 and July 2011 we reviewed 26,937 CT exams in 13,803 children. Among them, we included 931 children (median age 3.5 years, age range 0 days-15 years; M:F = 533:398) who had 5,339 CT exams. Each child underwent at least three CT scans and had accessible radiation dose reports. Dose-length product values were automatically extracted from DICOM files and we used recently updated conversion factors for age, gender, anatomical region and tube voltage to estimate CT radiation dose. We tracked the calculated CT dose estimates to obtain a 5-year cumulative value for each child. The study population was divided into three groups according to the cumulative CT dose estimates: high, ≥30 mSv; moderate, 10-30 mSv; and low, <10 mSv. We reviewed clinical data and CT protocols to identify major contributors to high and moderate cumulative CT dose estimates. Median cumulative CT dose estimate was 5.4 mSv (range 0.5-71.1 mSv), and median number of CT scans was 4 (range 3-36). High cumulative CT dose estimates were most common in children with malignant tumors (57.9%, 11/19). High frequency of CT scans was attributed to high cumulative CT dose estimates in children with ventriculoperitoneal shunt (35 in 1 child) and malignant tumors (range 18-49). Moreover, high-dose CT protocols, such as multiphase abdomen CT (median 4.7 mSv) contributed to high cumulative CT dose estimates even in children with a low number of CT scans. Disease group, number of CT scans, and high-dose CT protocols are major contributors to higher cumulative CT dose estimates in children. (orig.)

  9. Age- and gender-specific estimates of cumulative CT dose over 5 years using real radiation dose tracking data in children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunsol; Goo, Hyun Woo; Lee, Jae-Yeong [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of)

    2015-08-15

    It is necessary to develop a mechanism to estimate and analyze cumulative radiation risks from multiple CT exams in various clinical scenarios in children. To identify major contributors to high cumulative CT dose estimates using actual dose-length product values collected for 5 years in children. Between August 2006 and July 2011 we reviewed 26,937 CT exams in 13,803 children. Among them, we included 931 children (median age 3.5 years, age range 0 days-15 years; M:F = 533:398) who had 5,339 CT exams. Each child underwent at least three CT scans and had accessible radiation dose reports. Dose-length product values were automatically extracted from DICOM files and we used recently updated conversion factors for age, gender, anatomical region and tube voltage to estimate CT radiation dose. We tracked the calculated CT dose estimates to obtain a 5-year cumulative value for each child. The study population was divided into three groups according to the cumulative CT dose estimates: high, ≥30 mSv; moderate, 10-30 mSv; and low, <10 mSv. We reviewed clinical data and CT protocols to identify major contributors to high and moderate cumulative CT dose estimates. Median cumulative CT dose estimate was 5.4 mSv (range 0.5-71.1 mSv), and median number of CT scans was 4 (range 3-36). High cumulative CT dose estimates were most common in children with malignant tumors (57.9%, 11/19). High frequency of CT scans was attributed to high cumulative CT dose estimates in children with ventriculoperitoneal shunt (35 in 1 child) and malignant tumors (range 18-49). Moreover, high-dose CT protocols, such as multiphase abdomen CT (median 4.7 mSv) contributed to high cumulative CT dose estimates even in children with a low number of CT scans. Disease group, number of CT scans, and high-dose CT protocols are major contributors to higher cumulative CT dose estimates in children. (orig.)

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

    NARCIS (Netherlands)

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

    2001-01-01

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

  11. Evaluation of placental thickness as a sonological indicator for estimation of gestational age of foetus in normal singleton pregnancy

    Directory of Open Access Journals (Sweden)

    Lovely Kaushal

    2015-05-01

    Conclusion: A linear increase in mean placental thickness with gestational age was observed using correlation analysis in our present study conducted to determine the relationship between placental thickness and gestational age. Placental thickness measured in millimeters increases with gestational age from 11 weeks to 37 weeks. Placental thickness can be used as a predictor of the gestational age, in women in whom the last menstrual period is unreliable or is not known. In instances when femoral length was difficult to measure due to excessive foetal movements, Placental thickness was found to be a reliable alternative biometric measurement in calculating gestational age. [Int J Res Med Sci 2015; 3(5.000: 1213-1218

  12. Costs and Benefits of Representational Change: Effects of Context on Age and Sex Differences in Symbolic Magnitude Estimation

    Science.gov (United States)

    Thompson, Clarissa A.; Opfer, John E.

    2008-01-01

    Studies have reported high correlations in accuracy across estimation contexts, robust transfer of estimation training to novel numerical contexts, and adults drawing mistaken analogies between numerical and fractional values. We hypothesized that these disparate findings may reflect the benefits and costs of learning linear representations of…

  13. Collection and analysis of existing information on applicability of investigation methods for estimation of beginning age of faulting in present faulting pattern

    International Nuclear Information System (INIS)

    In the field of R and D programs of a geological disposal of high level radioactive waste, it is great importance to develop a set of investigation and analysis techniques for the assessment of long-term geosphere stability over a geological time, which means that any changes of geological environment will not significantly impact on the long-term safety of a geological disposal system. In Japanese archipelago, crustal movements are so active that uplift and subsidence are remarkable in recent several hundreds of thousands of years. Therefore, it is necessary to assess the long-term geosphere stability taking into account a topographic change caused by crustal movements. One of the factors for the topographic change is the movement of an active fault, which is a geological process to release a strain accumulated by plate motion. A beginning age of the faulting in the present faulting pattern suggests the beginning age of neotectonic activities around the active fault, and also provides basic information to identifying the stage of a geomorphic development of mountains. Therefore, the age of faulting in the present faulting pattern is important information to estimate a topographic change in the future on the mountain regions of Japan. In this study, existing information related to methods for the estimation of the beginning age of the faulting in the present faulting pattern on the active fault were collected and reviewed. A principle of method, noticing points and technical know-hows in the application of the methods, data uncertainty, and so on were extracted from the existing information. Based on these extracted information, task-flows indicating working process on the estimation of the beginning age for the faulting of the active fault were illustrated on each method. Additionally, the distribution map of the beginning age with accuracy of faulting in the present faulting pattern on the active fault was illustrated. (author)

  14. Development of a methylation marker set for forensic age estimation using analysis of public methylation data and the Agena Bioscience EpiTYPER system.

    Science.gov (United States)

    Freire-Aradas, A; Phillips, C; Mosquera-Miguel, A; Girón-Santamaría, L; Gómez-Tato, A; Casares de Cal, M; Álvarez-Dios, J; Ansede-Bermejo, J; Torres-Español, M; Schneider, P M; Pośpiech, E; Branicki, W; Carracedo, Á; Lareu, M V

    2016-09-01

    Individual age estimation has the potential to provide key information that could enhance and extend DNA intelligence tools. Following predictive tests for externally visible characteristics developed in recent years, prediction of age could guide police investigations and improve the assessment of age-related phenotype expression patterns such as hair colour changes and early onset of male pattern baldness. DNA methylation at CpG positions has emerged as the most promising DNA tests to ascertain the individual age of the donor of a biological contact trace. Although different methodologies are available to detect DNA methylation, EpiTYPER technology (Agena Bioscience, formerly Sequenom) provides useful characteristics that can be applied as a discovery tool in localized regions of the genome. In our study, a total of twenty-two candidate genomic regions, selected from the assessment of publically available data from the Illumina HumanMethylation 450 BeadChip, had a total of 177 CpG sites with informative methylation patterns that were subsequently investigated in detail. From the methylation analyses made, a novel age prediction model based on a multivariate quantile regression analysis was built using the seven highest age-correlated loci of ELOVL2, ASPA, PDE4C, FHL2, CCDC102B, C1orf132 and chr16:85395429. The detected methylation levels in these loci provide a median absolute age prediction error of ±3.07years and a percentage of prediction error relative to the age of 6.3%. We report the predictive performance of the developed model using cross validation of a carefully age-graded training set of 725 European individuals and a test set of 52 monozygotic twin pairs. The multivariate quantile regression age predictor, using the CpG sites selected in this study, has been placed in the open-access Snipper forensic classification website. PMID:27337627

  15. Age estimates for the buckwheat family Polygonaceae based on sequence data calibrated by fossils and with a focus on the amphi-Pacific Muehlenbeckia.

    Directory of Open Access Journals (Sweden)

    Tanja M Schuster

    Full Text Available The buckwheat family Polygonaceae is a diverse group of plants and is a good model for investigating biogeography, breeding systems, coevolution with symbionts such as ants and fungi, functional trait evolution, hybridization, invasiveness, morphological plasticity, pollen morphology and wood anatomy. The main goal of this study was to obtain age estimates for Polygonaceae by calibrating a Bayesian phylogenetic analysis, using a relaxed molecular clock with fossil data. Based on the age estimates, we also develop hypotheses about the historical biogeography of the Southern Hemisphere group Muehlenbeckia. We are interested in addressing whether vicariance or dispersal could account for the diversification of Muehlenbeckia, which has a "Gondwanan" distribution. Eighty-one species of Polygonaceae were analysed with MrBayes to infer species relationships. One nuclear (nrITS and three chloroplast markers (the trnL-trnF spacer region, matK and ndhF genes were used. The molecular data were also analysed with Beast to estimate divergence times. Seven calibration points including fossil pollen and a leaf fossil of Muehlenbeckia were used to infer node ages. Results of the Beast analyses indicate an age of 110.9 (exponential/lognormal priors/118.7 (uniform priors million years (Myr with an uncertainty interval of (90.7-125.0 Myr for the stem age of Polygonaceae. This age is older than previously thought (Maastrichtian, approximately 65.5-70.6 Myr. The estimated divergence time for Muehlenbeckia is 41.0/41.6 (39.6-47.8 Myr and its crown clade is 20.5/22.3 (14.2-33.5 Myr old. Because the breakup of Gondwana occurred from 95-30 Myr ago, diversification of Muehlenbeckia is best explained by oceanic long-distance and maybe stepping-stone dispersal rather than vicariance. This study is the first to give age estimates for clades of Polygonaceae and functions as a jumping-off point for future studies on the historical biogeography of the family.

  16. Age-related and stand-wise estimates of carbon stocks and sequestration in the aboveground coarse wood biomass of wetland forests in the northern Pantanal, Brazil

    Science.gov (United States)

    Schöngart, J.; Arieira, J.; Felfili Fortes, C.; Cezarine de Arruda, E.; Nunes da Cunha, C.

    2011-11-01

    In this study we use allometric models combined with tree ring analysis to estimate carbon stocks and sequestration in the aboveground coarse wood biomass (AGWB) of wetland forests in the Pantanal, located in central South America. In four 1-ha plots in stands characterized by the pioneer tree species Vochysia divergens Pohl (Vochysiaceae) forest inventories (trees ≥10 cm diameter at breast height, D) have been performed and converted to estimates of AGWB by two allometric models using three independent parameters (D, tree height H and wood density ρ). We perform a propagation of measurement errors to estimate uncertainties in the estimates of AGWB. Carbon stocks of AGWB vary from 7.8 ± 1.5 to 97.2 ± 14.4 Mg C ha-1 between the four stands. From models relating tree ages determined by dendrochronological techniques to C-stocks in AGWB we derived estimates for C-sequestration which differs from 0.50 ± 0.03 to 3.34 ± 0.31 Mg C ha-1 yr-1. Maps based on geostatistic techniques indicate the heterogeneous spatial distribution of tree ages and C-stocks of the four studied stands. This distribution is the result of forest dynamics due to the colonizing and retreating of V. divergens and other species associated with pluriannual wet and dry episodes in the Pantanal, respectively. Such information is essential for the management of the cultural landscape of the Pantanal wetlands.

  17. Accuracy of parent-reported information for estimating prevalence of overweight and obesity in a race-ethnically diverse pediatric clinic population aged 3 to 12

    OpenAIRE

    Gordon, Nancy P.; Mellor, R. Grant

    2015-01-01

    Background There is conflicting evidence about the accuracy of estimates of childhood obesity based on parent-reported data. We assessed accuracy of child height, weight, and overweight/obesity classification in a pediatric clinic population based on parent data to learn whether accuracy differs by child age and race/ethnicity. Methods Parents of patients ages 3–12 (n = 1,119) completed a waiting room questionnaire that asked about their child’s height and weight. Child’s height and weight wa...

  18. Estimating Geriatric Mortality after Injury Using Age, Injury Severity, and Performance of a Transfusion: The Geriatric Trauma Outcome Score

    OpenAIRE

    Zhao, Frank Z.; Wolf, Steven E.; Nakonezny, Paul A.; Minhajuddin, Abu; Rhodes, Ramona L.; Paulk, M. Elizabeth; Phelan, Herb A

    2015-01-01

    Abstract Background: A tool to determine the probability of mortality for severely injured geriatric patients is needed. Objective: We sought to create an easily calculated geriatric trauma prognostic score based on parameters available at the bedside to aid in mortality probability determination. Methods: All patients ≥65 years of age were identified from our Level I trauma center's registry between January 1, 2000 and December 31, 2013. Measurements included age, Injury Severity score (ISS)...

  19. An estimation of the prevalence of intellectual disabilities and its association with age in rural and urban populations in India

    Directory of Open Access Journals (Sweden)

    Ram Lakhan

    2015-01-01

    Full Text Available Background: Intellectual disability (ID is a global public health concern. Prevalence of ID and its association with age and other demographic factors is required for planning purposes in India. Objective: This study analyzed the age-adjusted prevalence of ID in rural and urban populations and its correlation with age in children and adults. Materials and Methods: Disability data published in the report (2002 of National Sample Survey Organization were analyzed, using Z-test to measure differences in age-adjusted prevalence. Spearman rho was calculated to determine strength and direction of the association, and regression analysis was used to predict prevalence rate, based on age in rural and urban population settings. Results: Overall, India has a prevalence of 10.5/1000 in ID. Urban population has slightly higher rate (11/1000 than rural (10.08/1000; P = 0.044. Age was found to be highly correlated with prevalence of ID in rural children (ϱ =0.981, P = 0.019 as well as in children (ϱ = −0.954, P = 0.000 and adults (ϱ = −0.957, P = 0.000 in urban population. The possibility of confounding or the existence of covariates for children in urban settings was noted. Conclusion: Results of this study match findings in other epidemiological studies. However, multistage, large-scale studies are recommended for investigating prevalence rates with different severity levels of ID.

  20. Estimation of the stand ages of tropical secondary forests after shifting cultivation based on the combination of WorldView-2 and time-series Landsat images

    Science.gov (United States)

    Fujiki, Shogoro; Okada, Kei-ichi; Nishio, Shogo; Kitayama, Kanehiro

    2016-09-01

    We developed a new method to estimate stand ages of secondary vegetation in the Bornean montane zone, where local people conduct traditional shifting cultivation and protected areas are surrounded by patches of recovering secondary vegetation of various ages. Identifying stand ages at the landscape level is critical to improve conservation policies. We combined a high-resolution satellite image (WorldView-2) with time-series Landsat images. We extracted stand ages (the time elapsed since the most recent slash and burn) from a change-detection analysis with Landsat time-series images and superimposed the derived stand ages on the segments classified by object-based image analysis using WorldView-2. We regarded stand ages as a response variable, and object-based metrics as independent variables, to develop regression models that explain stand ages. Subsequently, we classified the vegetation of the target area into six age units and one rubber plantation unit (1-3 yr, 3-5 yr, 5-7 yr, 7-30 yr, 30-50 yr, >50 yr and 'rubber plantation') using regression models and linear discriminant analyses. Validation demonstrated an accuracy of 84.3%. Our approach is particularly effective in classifying highly dynamic pioneer vegetation younger than 7 years into 2-yr intervals, suggesting that rapid changes in vegetation canopies can be detected with high accuracy. The combination of a spectral time-series analysis and object-based metrics based on high-resolution imagery enabled the classification of dynamic vegetation under intensive shifting cultivation and yielded an informative land cover map based on stand ages.

  1. 一种基于人脸图像的年龄估计方法%An Age Estimation Method Based on Facial Images

    Institute of Scientific and Technical Information of China (English)

    罗佳佳; 蔡超

    2012-01-01

    Research on age estimation has a significant impact on Human-Computer Interaction. In this paper, an age estimation method based on facial images is proposed. The new method establishes a face anthropometry template based on craniofacial growth pattern theory to obtain facial geometric proportion features, and extracts texture features of facial local area using fractional differential approach, combines these two kinds of features to form personal age feature vectors. Machine learning methods such as clustering algorithms we used to obtain age-feature knowledge matrix, and in age estimating, such knowledge matrix voting on estimate age of input facial image. Experimental results show that the estimation error is small and the classification accuracy is close to human judgment.%有关年龄估计的研究在人机交互领域有着非常重要的意义.该文提出一种基于人脸图像的年龄估计方法,该方法首先基于颅面成长模式理论建立人脸测量模板,在此模板上计算面部几何比例特征,然后运用分数阶微分提取人脸局部区域的纹理特征,结合这两类特征构成个体年龄特征向量;通过聚类学习的方法训练年龄特征向量获得年龄-特征映射矩阵,最后由此矩阵表决出输人人脸的估计年龄.实验结果表明,基于这两种特征构建的年龄估计模型可以获得较好的年龄估计结果,年龄误差较小,分类准确率接近人的主观判断结果.

  2. Estimating the lifetime economic burden of stroke according to the age of onset in South Korea: a cost of illness study

    Directory of Open Access Journals (Sweden)

    Suh Hae Sun

    2011-08-01

    Full Text Available Abstract Background The recently-observed trend towards younger stroke patients in Korea raises economic concerns, including erosion of the workforce. We compared per-person lifetime costs of stroke according to the age of stroke onset from the Korean societal perspective. Methods A state-transition Markov model consisted of three health states ('post primary stroke event', 'alive post stroke', and 'dead' was developed to simulate the natural history of stroke. The transition probabilities for fatal and non-fatal recurrent stroke by age and gender and for non-stroke causes of death were derived from the national epidemiologic data of the Korean Health Insurance Review and Assessment Services and data from the Danish Monitoring Trends in Cardiovascular Disease study. We used an incidence-based approach to estimate the long-term costs of stroke. The model captured stroke-related costs including costs within the health sector, patients' out-of-pocket costs outside the health sector, and costs resulting from loss of productivity due to morbidity and premature death using a human capital approach. Average insurance-covered costs occurring within the health sector were estimated from the National Health Insurance claims database. Other costs were estimated based on the national epidemiologic data and literature. All costs are presented in 2008 Korean currency values (Korean won = KRW. Results The lifetime costs of stroke were estimated to be: 200.7, 81.9, and 16.4 million Korean won (1,200 KRW is approximately equal to one US dollar for men who suffered a first stroke at age 45, 55 and 65 years, respectively, and 75.7, 39.2, and 19.3 million KRW for women at the same age. While stroke occurring among Koreans aged 45 to 64 years accounted for only 30% of the total disease incidence, this age group incurred 75% of the total national lifetime costs of stroke. Conclusions A higher lifetime burden and increasing incidence of stroke among younger Koreans

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

    Science.gov (United States)

    Wilson, J. A.; Richardson, J. A.

    2015-12-01

    Traditional methods used to calculate recurrence rate of volcanism, such as linear regression, maximum likelihood and Weibull-Poisson distributions, are effective at estimating recurrence rate and confidence level, but these methods are unable to estimate uncertainty in recurrence rate through time. We propose a new model for estimating recurrence rate and uncertainty, Volcanic Event Recurrence Rate Model. VERRM is an algorithm that incorporates radiometric ages, volcanic stratigraphy and paleomagnetic data into a Monte Carlo simulation, generating acceptable ages for each event. Each model run is used to calculate recurrence rate using a moving average window. These rates are binned into discrete time intervals and plotted using the 5th, 50th and 95th percentiles. We present recurrence rates from Cima Volcanic Field (CA), Yucca Mountain (NV) and Arsia Mons (Mars). Results from Cima Volcanic Field illustrate how several K-Ar ages with large uncertainties obscure three well documented volcanic episodes. Yucca Mountain results are similar to published rates and illustrate the use of using the same radiometric age for multiple events in a spatially defined cluster. Arsia Mons results show a clear waxing/waning of volcanism through time. VERRM output may be used for a spatio-temporal model or to plot uncertainty in quantifiable parameters such as eruption volume or geochemistry. Alternatively, the algorithm may be reworked to constrain geomagnetic chrons. VERRM is implemented in Python 2.7 and takes advantage of NumPy, SciPy and matplotlib libraries for optimization and quality plotting presentation. A typical Monte Carlo simulation of 40 volcanic events takes a few minutes to couple hours to complete, depending on the bin size used to assign ages.

  4. Hospital-based surveillance to estimate the burden of rotavirus gastroenteritis in children below five years of age in Romania

    Science.gov (United States)

    Anca, Ioana Alina; Furtunescu, Florentina Ligia; Pleşca, Doina; Streinu-Cercel, Adrian; Rugină, Sorin; Holl, Katsiaryna

    2014-01-01

    Introduction Rotavirus (RV) is a leading cause of acute gastroenteritis (AGE), affecting 95% of children below five years of age. Methods In this prospective, multi-center study, children below five years of age who were hospitalized or those who visited the emergency room (ER) due to AGE or who developed AGE at least 48 hours after hospitalization (nosocomial infection) and had a RV-positive stool sample were included (n=1,222). RV-positive samples were genotyped by reverse-transcriptase polymerase chain reaction. Results RV test results were available for 1,212 children (hospitalizations [n=677], ER visits [n=398] and nosocomial AGE cases [n=137]). Proportions of rotavirus gastroenteritis (RVGE) hospitalizations and ER visits were 51.70% (350/677; 95%CI: 47.86–55.52) and 36.18% (144/398; 95%CI: 31.45–41.12), respectively. Overall, 45.95% (494/1075) of all community-acquired AGE cases were due to RV. High numbers of RVGE cases were recorded between January and March. Most common genotypes were G9P[8] (34.27%) followed by G4P[8] (25.83%) and G1P[8] (23.02%). Of all community-acquired RVGE cases, the highest number of cases was observed in children aged 12–23 months. Median duration of hospitalization among RV-positive subjects was six days (range: 2–31 days). Incidence of nosocomial RVGE was 0.52 (95%CI: 0.45–0.60) cases per 1,000 child-days hospitalization. Median duration for additional hospitalization due to nosocomial RVGE was five days (range: 1–10). The highest burden of nosocomial RVGE was observed in children aged 12–23 months (42.34%, 58/137). Our findings confirm a high burden of acute RVGE disease in Romania and provide useful data to support the implementation of RV vaccination in Romania. Trial registration NCT01253967 PMID:24967217

  5. An improved model to estimate trapping parameters in polymeric materials and its application on normal and aged low-density polyethylenes

    International Nuclear Information System (INIS)

    Trapping parameters can be considered as one of the important attributes to describe polymeric materials. In the present paper, a more accurate charge dynamics model has been developed, which takes account of charge dynamics in both volts-on and off stage into simulation. By fitting with measured charge data with the highest R-square value, trapping parameters together with injection barrier of both normal and aged low-density polyethylene samples were estimated using the improved model. The results show that, after long-term ageing process, the injection barriers of both electrons and holes is lowered, overall trap depth is shallower, and trap density becomes much greater. Additionally, the changes in parameters for electrons are more sensitive than those of holes after ageing

  6. An improved model to estimate trapping parameters in polymeric materials and its application on normal and aged low-density polyethylenes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ning, E-mail: nl4g12@soton.ac.uk; He, Miao; Alghamdi, Hisham; Chen, George [School of Electronic and Computer Science, University of Southampton, Southampton (United Kingdom); Fu, Mingli; Li, Ruihai; Hou, Shuai [Electric Power Research Institute of China Southern Power Grid, Guangzhou (China)

    2015-08-14

    Trapping parameters can be considered as one of the important attributes to describe polymeric materials. In the present paper, a more accurate charge dynamics model has been developed, which takes account of charge dynamics in both volts-on and off stage into simulation. By fitting with measured charge data with the highest R-square value, trapping parameters together with injection barrier of both normal and aged low-density polyethylene samples were estimated using the improved model. The results show that, after long-term ageing process, the injection barriers of both electrons and holes is lowered, overall trap depth is shallower, and trap density becomes much greater. Additionally, the changes in parameters for electrons are more sensitive than those of holes after ageing.

  7. A variation of the housing unit method for estimating the age and gender distribution of small, rural areas: A case study of the local expert procedure

    International Nuclear Information System (INIS)

    This paper describes the methodologies used in the development of a demographic data base established in support of the Yucca Mountain Site Characterization Project Radiological Monitoring Plan (RadMP). It also examines the suitability of a survey-based procedure for estimating population in small, rural areas. The procedure is a variation of the Housing Unit Method. It employs the use of local experts enlisted to provide information about the demographic characteristics of households randomly selected from residential units sample frames developed from utility records. The procedure is nonintrusive and less costly than traditional survey data collection efforts. Because the procedure is based on random sampling, confidence intervals can be constructed around the population estimated by the technique. The results of a case study are provided in which the total population, and age and gender of the population, is estimated for three unincorporated communities in rural, southern Nevada

  8. A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary

    Science.gov (United States)

    Wilson, C.J.N.; Rhoades, D.A.; Lanphere, M.A.; Calvert, A.T.; Houghton, B.F.; Weaver, S.D.; Cole, J.W.

    2007-01-01

    Pyroclastic fall deposits of the paired Rotoiti and Earthquake Flat eruptions from the Taupo Volcanic Zone (New Zealand) combine to form a widespread isochronous horizon over much of northern New Zealand and the southwest Pacific. This horizon is important for correlating climatic and environmental changes during the Last Glacial period, but has been the subject of numerous disparate age estimates between 35.1??2.8 and 71??6 ka (all errors are 1 s.d.), obtained by a variety of techniques. A potassium-argon (K-Ar) age of 64??4 ka was previously determined on bracketing lavas at Mayor Island volcano, offshore from the Taupo Volcanic Zone. We present a new, more-precise 40Ar/39Ar age determination on a lava flow on Mayor Island, that shortly post-dates the Rotoiti/Earthquake Flat fall deposits, of 58.5??1.1 ka. This value, coupled with existing ages from underlying lavas, yield a new estimate for the age of the combined eruptions of 61.0??1.4 ka, which is consistent with U-Th disequilibrium model-age data for zircons from the Rotoiti deposits. Direct 40Ar/39Ar age determinations of plagioclase and biotite from the Rotoiti and Earthquake Flat eruption products yield variable values between 49.6??2.8 and 125.3??10.0 ka, with the scatter attributed to low radiogenic Ar yields, and/or alteration, and/or inheritance of xenocrystic material with inherited Ar. Rotoiti/Earthquake Flat fall deposits occur in New Zealand in association with palynological indicators of mild climate, attributed to Marine Isotope Stage (MIS) 3 and thus used to suggest an age that is post-59 ka. The natures of the criteria used to define the MIS 4/3 boundary in the Northern and Southern hemispheres, however, imply that the new 61 ka age for the Rotoiti/Earthquake Flat eruption deposits will provide the inverse, namely, a more accurate isochronous marker for correlating diverse changes across the MIS 4/3 boundary in the southwest Pacific. ?? 2007 Elsevier Ltd. All rights reserved.

  9. Estimated Prevalence of Attention-Deficit/Hyperactivity Disorder in a Sample of Panamanian School-Aged Children

    Science.gov (United States)

    Sanchez, Emelyn Y.; Velarde, Silvia; Britton, Gabrielle B.

    2011-01-01

    The present study investigated the prevalence of ADHD in a school sample of children ages 6-11 years in the city of Panama. The assessment battery included the Conners' Parent and Teacher Rating Scales, the Structured Developmental History of the Behavioral Assessment System for Children (BASC-2), and the Wechsler Intelligence Scale for Children…

  10. Age-related differences in time-based prospective memory: The role of time estimation in the clock monitoring strategy.

    Science.gov (United States)

    Vanneste, Sandrine; Baudouin, Alexia; Bouazzaoui, Badiâa; Taconnat, Laurence

    2016-07-01

    Time-based prospective memory (TBPM) is required when it is necessary to remember to perform an action at a specific future point in time. This type of memory has been found to be particularly sensitive to ageing, probably because it requires a self-initiated response at a specific time. In this study, we sought to examine the involvement of temporal processes in the time monitoring strategy, which has been demonstrated to be a decisive factor in TBPM efficiency. We compared the performance of young and older adults in a TBPM task in which they had to press a response button every minute while categorising words. The design allowed participants to monitor time by checking a clock whenever they decided. Participants also completed a classic time-production task and several executive tasks assessing inhibition, updating and shifting processes. Our results confirm an age-related lack of accuracy in prospective memory performance, which seems to be related to a deficient strategic use of time monitoring. This could in turn be partially explained by age-related temporal deficits, as evidenced in the duration production task. These findings suggest that studies designed to investigate the age effect in TBPM tasks should consider the contribution of temporal mechanisms. PMID:26247302

  11. A method for estimating age of medieval sub-adults from infancy to adulthood based on long bone length

    DEFF Research Database (Denmark)

    Primeau, Charlotte; Friis, Laila Saidane; Sejrsen, Birgitte; Lynnerup, Niels

    2016-01-01

    a modern population (Maresh: Human growth and development () pp 155-200), and, lastly, based on archeological data with known ages (Rissech et al.: Forensic Sci Int 180 () 1-9). As growth of long bones is known to be non-linear it was tested if the regression model could be improved by applying a...

  12. Evaluation of alternative age-based methods for estimating relative abundance from survey data in relation to assessment models

    DEFF Research Database (Denmark)

    Berg, Casper Willestofte; Nielsen, Anders; Kristensen, Kasper

    2014-01-01

    Indices of abundance from fishery-independent trawl surveys constitute an important source of information for many fish stock assessments. Indices are often calculated using area stratified sample means on age-disaggregated data, and finally treated in stock assessment models as independent...... observations. We evaluate a series of alternative methods for calculating indices of abundance from trawl survey data (delta-lognormal, delta-gamma, and Tweedie using Generalized Additive Models) as well as different error structures for these indices when used as input in an age-based stock assessment model...... different indices produced. The stratified mean method is found much more imprecise than the alternatives based on GAMs, which are found to be similar. Having time-varying index variances is found to be of minor importance, whereas the independence assumption is not only violated but has significant impact...

  13. Estimation of the Age and Amount of Brown Rice Plant Hoppers Based on Bionic Electronic Nose Use

    OpenAIRE

    Sai Xu; Zhiyan Zhou; Huazhong Lu; Xiwen Luo; Yubin Lan; Yang Zhang; Yanfang Li

    2014-01-01

    The brown rice plant hopper (BRPH), Nilaparvata lugens (Stal), is one of the most important insect pests affecting rice and causes serious damage to the yield and quality of rice plants in Asia. This study used bionic electronic nose technology to sample BRPH volatiles, which vary in age and amount. Principal component analysis (PCA), linear discrimination analysis (LDA), probabilistic neural network (PNN), BP neural network (BPNN) and loading analysis (Loadings) techniques were used to analy...

  14. Age-related and stand-wise estimates of carbon stocks and sequestration in the aboveground coarse wood biomass of wetland forests in the northern Pantanal, Brazil

    Directory of Open Access Journals (Sweden)

    J. Schöngart

    2011-11-01

    Full Text Available In this study we use allometric models combined with tree ring analysis to estimate carbon stocks and sequestration in the aboveground coarse wood biomass (AGWB of wetland forests in the Pantanal, located in central South America. In four 1-ha plots in stands characterized by the pioneer tree species Vochysia divergens Pohl (Vochysiaceae forest inventories (trees ≥10 cm diameter at breast height, D have been performed and converted to estimates of AGWB by two allometric models using three independent parameters (D, tree height H and wood density ρ. We perform a propagation of measurement errors to estimate uncertainties in the estimates of AGWB. Carbon stocks of AGWB vary from 7.8 ± 1.5 to 97.2 ± 14.4 Mg C ha−1 between the four stands. From models relating tree ages determined by dendrochronological techniques to C-stocks in AGWB we derived estimates for C-sequestration which differs from 0.50 ± 0.03 to 3.34 ± 0.31 Mg C ha−1 yr−1. Maps based on geostatistic techniques indicate the heterogeneous spatial distribution of tree ages and C-stocks of the four studied stands. This distribution is the result of forest dynamics due to the colonizing and retreating of V. divergens and other species associated with pluriannual wet and dry episodes in the Pantanal, respectively. Such information is essential for the management of the cultural landscape of the Pantanal wetlands.

  15. Cuffless Blood Pressure Estimation with Photoplethysmograph Signal by Classifying on Account of Cardiovascular Characteristics of Old Aged Patients

    Science.gov (United States)

    Suzuki, Satomi; Oguri, Koji

    Blood Pressure (BP) is a very important factor for monitoring the cardiovascular condition. In general, non-invasive BP measurements need a cuff. However, such measurement techniques can hardly monitor BP continuously. Recently it has gotten easier to measure biological signals daily because sensor technologies have well-developed, and because of availability of many kinds of miniaturized measurement instruments consuming less power. This study suggests a method of estimating Systolic Blood Pressure (SBP) with a wearable sensor instead of a cuff. In particular, our study depends on only one pulse wave signal detected by a Photoplethysmograph (PPG) sensor since the PPG sensor is very small. Moreover, the human subject just wears the sensor on the surface of the body to measure the signal. Cardiovascular peculiarities keep changing as people get older. Additionally, the peculiarities vary among individuals according to the advanced rate of arteriosclerosis. Hence, it is necessary for estimating the SBP to divide the data into several classes, by parameters that relate to individual cardiovascular peculiarities. In this study, the regression equation of SBP was calculated from individual information and from features of the PPG signal in each class. As a result, the estimation accuracy was improved. This technique would make cuffless SBP monitoring become more convenient and helpful as only one device is required for monitoring, which is smaller than traditional measurements.

  16. AB226. The relationship between self-estimated intravaginal ejaculatory latency time and International Prostate Symptom Score in middle-aged men complaining of ejaculating prematurely in China

    Science.gov (United States)

    Zhang, X; Tang, D

    2016-01-01

    Objective We performed this study to evaluate the association between International Prostate Symptom Score (IPSS) and intravaginal ejaculatory latency time (IELT) in men with the four premature ejaculation (PE) syndromes. Methods From June 2012 to January 2014, a total of 690 men aged 40–59 years complaining of ejaculating prematurely and another 452 male healthy subjects of the same age without these complaints were included in this study. Men with the complaints of ejaculating prematurely were classified as one of the four PE syndromes: lifelong PE, acquired PE (APE), variable PE, and subjective PE. Each of them completed a detailed questionnaire including information on demographics, medical and sexual history (e.g., self-estimated IELT), IPSS, and International Index of Erectile Function-5. Results Men complaining of ejaculating prematurely reported higher IPSS (11.2±6.0 vs. 5.5±3.3) and shorter self-estimated IELT (2.1±1.6 vs. 4.8±3.3 min) than men without complaints (Pejaculating prematurely reported worse IPSS than men without these complaints. Self-estimated IELT was negatively associated with IPSS in men complaining of ejaculating prematurely, and the correlation was the strongest in men with APE.

  17. Fertility and Female Labor-Force Participation: Estimates and Projections for Austrian Women Aged 20-30

    OpenAIRE

    Neusser, K.

    1981-01-01

    The sharp and unexpected decline in fertility rates during the 1960s and 1970s provoked a great deal of controversy. What was the cause of this decline? What will be its future path? There were two opposing schools in this debate: Becker and the "human capital" school on one side and Easterlin and his school on the other. The former emphasized that the rise in women's real wage rates drove up the opportunity cost of having children, whereas the latter emphasized the age structure of the popul...

  18. The Use of CT Scans in Estimating Age at Death by Examining the Extent of Ectocranial Suture Closure

    DEFF Research Database (Denmark)

    Boyd, Kristen Leigh; Villa, Chiara; Lynnerup, Niels

    2015-01-01

    We examined the utility of CT scans in the evaluation of degree of ectocranial suture closure. Five cranial points (left and right midcoronal positions, left and right midlambdoidal positions, and the lambda) were evaluated in 231 CT scans using a three-point scoring system (open, partial closed...... using CT scans......., and closed). The slice increment and thickness varied between three groups of the scans. The results showed a good correlation between degree of suture closure and increasing age in each group. Young individuals (<40 years) and old individuals (>60 years) could be clearly distinguished from the middle...

  19. International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation

    DEFF Research Database (Denmark)

    Peixoto, Ana; Santos, Catarina; Pinheiro, Manuela;

    2011-01-01

    total of 5,443 suspected HBOC families from several countries. Whereas the c.156_157insAlu BRCA2 mutation was detected in 11 of 149 suspected HBOC families from Portugal, representing 37.9% of all deleterious mutations, in other countries it was detected only in one proband living in France and in four...... individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 +/- 215 years ago. We further demonstrate significant quantitative differences...

  20. International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation

    DEFF Research Database (Denmark)

    Peixoto, Ana; Santos, Catarina; Pinheiro, Manuela;

    2011-01-01

    total of 5,443 suspected HBOC families from several countries. Whereas the c.156_157insAlu BRCA2 mutation was detected in 11 of 149 suspected HBOC families from Portugal, representing 37.9% of all deleterious mutations, in other countries it was detected only in one proband living in France and in four...... individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 ± 215 years ago. We further demonstrate significant quantitative differences...

  1. Estimated age and gender profile of individuals missed by a home-based HIV testing and counselling campaign in a Botswana community

    Directory of Open Access Journals (Sweden)

    Vlad Novitsky

    2015-05-01

    Full Text Available Introduction: It would be useful to understand which populations are not reached by home-based HIV-1 testing and counselling (HTC to improve strategies aimed at linking these individuals to care and reducing rates of onward HIV transmission. Methods: We present the results of a baseline home-based HTC (HBHTC campaign aimed at counselling and testing residents aged 16 to 64 for HIV in the north-eastern sector of Mochudi, a community in Botswana with about 44,000 inhabitants. Collected data were compared with population references for Botswana, the United Nations (UN estimates based on the National Census data and the Botswana AIDS Impact Survey IV (BAIS-IV. Analyzed data and references were stratified by age and gender. Results: A total of 6238 age-eligible residents were tested for HIV-1; 1247 (20.0%; 95% CI 19.0 to 21.0% were found to be HIV positive (23.7% of women vs. 13.4% of men. HIV-1 prevalence peaked at 44% in 35- to 39-year-old women and 32% in 40- to 44-year-old men. A lower HIV prevalence rate, 10.9% (95% CI 9.5 to 12.5%, was found among individuals tested for the first time. A significant gender gap was evident in all analyzed subsets. The existing HIV transmission network was analyzed by combining phylogenetic mapping and household structure. Between 62.4 and 71.8% of all HIV-positive individuals had detectable virus. When compared with the UN and BAIS-IV estimates, the proportion of men missed by the testing campaign (48.5%; 95% CI 47.0 to 50.0% was significantly higher than the proportion of missed women (14.2%; 95% CI 13.2 to 15.3%; p<0.0001. The estimated proportion of missed men peaked at about 60% in the age group 30 to 39 years old. The proportions of missed women were substantially smaller, at approximately 28% within the age groups 30 to 34 and 45 to 49 years old. Conclusions: The HBHTC campaign seems to be an efficient tool for reaching individuals who have never been tested previously in southern African communities

  2. Age and gender specific estimation of visceral adipose tissue amounts from radiological images in morbidly obese patients

    Science.gov (United States)

    Linder, Nicolas; Schaudinn, Alexander; Garnov, Nikita; Blüher, Matthias; Dietrich, Arne; Schütz, Tatjana; Lehmann, Stefanie; Retschlag, Ulf; Karlas, Thomas; Kahn, Thomas; Busse, Harald

    2016-01-01

    Image-based quantifications of visceral adipose tissue (VAT) volumes from segmented VAT areas are increasingly considered for risk assessment in obese patients. The goal of this study was to determine the power of partial VAT areas to predict total VAT volume in morbidly obese patients (BMI > 40 kg/m2) as a function of gender, age and anatomical landmarks. 130 morbidly obese patients (mean BMI 46.5 kg/m2; 94 females) underwent IRB-approved MRI. Total VAT volumes were predicted from segmented VAT areas (of single or five adjacent slices) at common axial landmark levels and compared with the measured ones (VVAT-T, about 40 slices between diaphragm and pelvic floor). Standard deviations σ1 and σ5 of the respective VAT volume differences served as measures of agreement. Mean VVAT-T was 4.9 L for females and 8.1 L for males. Best predictions were found at intervertebral spaces L3-L4 for females (σ5 = 688 ml, σ1 = 832 ml) and L1-L2 for males (σ5 = 846 ml, σ1 = 992 ml), irrespective of age. In conclusion, VAT volumes in morbidly obese patients can be reliably predicted by multiplying the segmented VAT area at a gender-specific lumbar reference level with a fixed scaling factor and effective slice thickness. PMID:27009353

  3. One Small Step for a Man: Estimation of Gender, Age and Height from Recordings of One Step by a Single Inertial Sensor

    Directory of Open Access Journals (Sweden)

    Qaiser Riaz

    2015-12-01

    Full Text Available A number of previous works have shown that information about a subject is encoded in sparse kinematic information, such as the one revealed by so-called point light walkers. With the work at hand, we extend these results to classifications of soft biometrics from inertial sensor recordings at a single body location from a single step. We recorded accelerations and angular velocities of 26 subjects using integrated measurement units (IMUs attached at four locations (chest, lower back, right wrist and left ankle when performing standardized gait tasks. The collected data were segmented into individual walking steps. We trained random forest classifiers in order to estimate soft biometrics (gender, age and height. We applied two different validation methods to the process, 10-fold cross-validation and subject-wise cross-validation. For all three classification tasks, we achieve high accuracy values for all four sensor locations. From these results, we can conclude that the data of a single walking step (6D: accelerations and angular velocities allow for a robust estimation of the gender, height and age of a person.

  4. Estimation of porosity of Khewra sandstone of cambrian age by using helium porosimeter and its application in reservoir evaluation

    International Nuclear Information System (INIS)

    Estimation of petrophysical properties of the rock formations played decisive role in all the processes of petroleum exploration. The Cambrian sequence is well established as reservoir rocks in the various parts of the world from where petroleum is being tapped. The Cambrian sequence has been encountered in the Potwar area and limited petroleum is being produced from the Adhi Oil Field. The Khewra Sandstone of the Cambrian sequence is outcropped in the Khewra Gorge, Salt Range Pakistan below an unconformity qf the Tobra Formation. For the assessment of porosity and reservoir characterization Helium Porosimeter has been used, six samples Qf the upper horizon were collected from various locations of the Khewra Gorge and the Khewra Choha Sadden Shah road side section; cores were prepared from these samples according to the instrument standard. The results of this study revealed that the upper horizon Qf the Khewra Sandstone Formation has good porosity ranging from 18.76% to 21.07%, porosity varied in different parts of the formation. These results are in good agreement with the internationally reported values for petroleum reservoir of the Cambrian sandstone. (author)

  5. EVOLUTION OF CHEMICAL CONDITIONS AND ESTIMATED PLUTONIUM SOLUBILITY IN THE RESIDUAL WASTE LAYER DURING POST-CLOSURE AGING OF TANK 18

    Energy Technology Data Exchange (ETDEWEB)

    Denham, M.

    2012-02-29

    This document updates the Eh-pH transitions from grout aging simulations and the plutonium waste release model of Denham (2007, Rev. 1) based on new data. New thermodynamic data for cementitious minerals are used for the grout simulations. Newer thermodynamic data, recommended by plutonium experts (Plutonium Solubility Peer Review Report, LA-UR-12-00079), are used to estimate solubilities of plutonium at various pore water compositions expected during grout aging. In addition, a new grout formula is used in the grout aging simulations and apparent solubilities of coprecipitated plutonium are estimated using data from analysis of Tank 18 residual waste. The conceptual model of waste release and the grout aging simulations are done in a manner similar to that of Denham (2007, Rev. 1). It is assumed that the pore fluid composition passing from the tank grout into the residual waste layer controls the solubility, and hence the waste release concentration of plutonium. Pore volumes of infiltrating fluid of an assumed composition are reacted with a hypothetical grout block using The Geochemist's Workbench{reg_sign} and changes in pore fluid chemistry correspond to the number of pore fluid volumes reacted. As in the earlier document, this results in three states of grout pore fluid composition throughout the simulation period that are termed Reduced Region II, Oxidized Region II, and Oxidized Region III. The one major difference from the earlier document is that pyrite is used to account for reducing capacity of the tank grout rather than pyrrhotite. This poises Eh at -0.47 volts during Reduced Region II. The major transitions in pore fluid composition are shown. Plutonium solubilities are estimated for discrete PuO2(am,hyd) particles and for plutonium coprecipitated with iron phases in the residual waste. Thermodynamic data for plutonium from the Nuclear Energy Agency are used to estimate the solubilities of the discrete particles for the three stages of pore fluid

  6. Ultrastructure of lamellae, mineral and matrix components of fish otolith twinned aragonite crystals: implications for estimating age in fish.

    Science.gov (United States)

    Gauldie, R W

    1999-05-01

    Atomic force microscopy (AFM) of the crystalline ultrastructure of otoliths fromPagrus major(Sparidae),Macruronus novaezelandiae(Merlucciidae),Oncorhynchus tshawytscha(Salmonidae),Sebastes alutus(Scorpaenidae), andHoplostethus atlanticus(Trachichthyidae) showed regular deposition of lamellae in the size range 13-490 nm. The orientation of lamellae in the {010} plane was the same as lamellae in crystals of mineral aragonite. Lamellae in mineral aragonite were in the size range 15-45 nm. Lamellae observed in the otolith ofM. novaezelandiaeby transmission electron microscopy showed a range of widths (25-225 nm) similar to lamellae observed by AFM. The observed lamella widths were in the size range that has been described for sub-daily and daily microincrements in otoliths. Observed lamellae widths were also in the size range of alpha-recoil trajectories of(222)Rn and provide a potential diffusion sink correction for the(222)Rn losses in radionuclide method of ageing otoliths. Comparison of the orientations of lamellae to templates based on the Bragg unit cell structure of twinned aragonite indicated that the lamellae resulted from polysynthetic twinning on the {010} aragonite crystal face. Additional cyclic twinning occurred on the {110} face of the aragonite crystal and sometimes led to pseudohexagonal crystals, whose sizes were orders of magnitude larger than lamellae. The organic matrix of the otolith was visible by atomic force and transmission electron microscopy at the nanometer level of resolution, but the organic matrix was confined to the {110} twinning plane of symmetry of the otolith crystal. PMID:18627853

  7. Bone age estimation and prediction of final height in patients with {beta}-thalassaemia major: a comparison between the two most common methods

    Energy Technology Data Exchange (ETDEWEB)

    Christoforidis, Athanasios; Katzos, George; Athanassiou-Metaxa, Miranda [Aristotle University of Thessaloniki, 1st Paediatric Department, Thessaloniki (Greece); Badouraki, Maria [Ippokratio Hospital, Paediatric Radiology Department, Thessaloniki (Greece)

    2007-12-15

    Thalassaemic patients are in need of frequent assessment of bone age because of growth failure and pubertal disorders. To compare the ''rapid'' Greulich and Pyle (G and P) method with the third edition of the Tanner and Whitehouse (TW3) method for determining skeletal maturity and predicting final height in thalassaemic patients. A total of 191 radiographs from 58 patients (28 male, 30 female) were retrospectively evaluated by two investigators, one for each method. In 47 radiographs from 15 patients having attained their adult height, predicted final height was calculated according to each method. The mean bone ages determined by both the G and P and TW3 methods were lower than mean chronological age, although the differences were not statistically significant (10.04 {+-} 3.69 years and 9.98 {+-} 3.39 years vs. 10.78 {+-} 3.96 years, respectively). Both methods had a tendency to over-estimate final height. Overall, the TW3 method seemed to be more accurate than the G and P method (mean absolute error 3.21 {+-} 2.51 years vs. 3.99 {+-} 2.99 years, respectively, P=0.048). The same method should be used when serial assessments are performed, as both methods provide similarly reliable, although not equivalent, results. The TW3 height prediction method seemed to be more accurate in patients with {beta}-thalassaemia major than the G and P method, albeit with a large confidence interval. (orig.)

  8. Bone age estimation and prediction of final height in patients with β-thalassaemia major: a comparison between the two most common methods

    International Nuclear Information System (INIS)

    Thalassaemic patients are in need of frequent assessment of bone age because of growth failure and pubertal disorders. To compare the ''rapid'' Greulich and Pyle (G and P) method with the third edition of the Tanner and Whitehouse (TW3) method for determining skeletal maturity and predicting final height in thalassaemic patients. A total of 191 radiographs from 58 patients (28 male, 30 female) were retrospectively evaluated by two investigators, one for each method. In 47 radiographs from 15 patients having attained their adult height, predicted final height was calculated according to each method. The mean bone ages determined by both the G and P and TW3 methods were lower than mean chronological age, although the differences were not statistically significant (10.04 ± 3.69 years and 9.98 ± 3.39 years vs. 10.78 ± 3.96 years, respectively). Both methods had a tendency to over-estimate final height. Overall, the TW3 method seemed to be more accurate than the G and P method (mean absolute error 3.21 ± 2.51 years vs. 3.99 ± 2.99 years, respectively, P=0.048). The same method should be used when serial assessments are performed, as both methods provide similarly reliable, although not equivalent, results. The TW3 height prediction method seemed to be more accurate in patients with β-thalassaemia major than the G and P method, albeit with a large confidence interval. (orig.)

  9. Estimation of groundwater age in the central part of the Baltic Artesian Basin based on new isotope data from Latvia

    Science.gov (United States)

    Babre, Alise; Kalvans, Andis; Popovs, Konrads; Retike, Inga; Delina, Aija

    2015-04-01

    Hydrogeological conditions of the Baltic Artesian basin (BAB) have changed rapidly during the Quaternary period. Therefore this work aims to give better overview of the complexity of the groundwater recharge and discharge dynamics beyond country borders, taking into account only shared geological framework, common climate conditions and geological development. To maintain better understanding of the processes that took part in the formation of groundwater that can be observed nowadays several methods were applied placing major emphasis on the new oxygen and hydrogen stable isotope ratio results. Earlier investigations in the northern part of the basin indicated glacial melt water intrusion in the Cambrian-Vendian. Several radiocarbon and stable isotope studies in groundwater have been done at the southern part of the basin as well reporting extensive groundwater recharge during the Late Pleistocene suggesting that recharge took place under different recharge mechanisms compared with the northern part. In 2010 to 2012 an extensive field campaign was undertaken, collecting more than 300 groundwater samples for deuterium and stable oxygen, 30 for stable carbon and 10 for radiocarbon analysis mostly from central part (Latvia) of the BAB covering all the major aquifer systems where previously collected data was sparse or absent. A specific motivation for the research was to identify relict glacial meltwater in the groundwater system. The broader aim was to estimate the baseline isotopic composition of groundwater in the region. Here a new data set is presented. Na-Ca-Cl brine found at the deepest - stagnation zone and is characterized by δ18O values above -5 o and δD values approaching -40 o in respect to VSMOW. The slow exchange zone is characterized by δ18O values around -11.7 o and δD values around -84.8 o . Mean δ18O and δD value of the groundwater in the active water exchange zone is -11.0 o and 79.2 o respectively. Characteristically the groundwater in the

  10. Age-specific interval breast cancers in Japan. Estimation of the proper sensitivity of screening using a population-based cancer registry

    International Nuclear Information System (INIS)

    The age-specific sensitivity of a screening program was investigated using a population-based cancer registry as a source of false-negative cancer cases. A population-based screening program for breast cancer was run using either clinical breast examinations (CBE) alone or mammography combined with CBE in the Miyagi Prefecture from 1997 to 2002. Interval cancers were newly identified by linking the screening records to the population-based cancer registry to estimate the number of false-negative cases of screening program. Among 112071 women screened by mammography combined with CBE, the number of detected cancers, false-negative cases and the sensitivity were 289, 22 and 92.9%, respectively, based on the reports from participating municipalities. The number of newly found false-negative cases and corrected sensitivity when using the registry were 34 and 83.8%, respectively. In detected cancers, the sensitivity of screening by mammography combined with CBE in women ranging from 40 to 49 years of age based on a population-based cancer registry was much lower than that in women 50-59 and 60-69 years of age (40-49: 18, 71.4%, 50-59: 19, 85.8%, 60-69: 19, 87.2%). These data suggest that the accurate outcome of an evaluation of breast cancer screening must include the use of a population-based cancer registry for detecting false-negative cases. Screening by mammography combined with CBE may therefore not be sufficiently sensitive for women ranging from 40 to 49 years of age. (author)

  11. Estimating biomass of mixed and uneven-aged forests using spectral data and a hybrid model combining regression trees and linear models

    Directory of Open Access Journals (Sweden)

    López-Serrano PM

    2016-04-01

    Full Text Available The Sierra Madre Occidental mountain range (Durango, Mexico is of great ecological interest because of the high degree of environmental heterogeneity in the area. The objective of the present study was to estimate the biomass of mixed and uneven-aged forests in the Sierra Madre Occidental by using Landsat-5 TM spectral data and forest inventory data. We used the ATCOR3® atmospheric and topographic correction module to convert remotely sensed imagery digital signals to surface reflectance values. The usual approach of modeling stand variables by using multiple linear regression was compared with a hybrid model developed in two steps: in the first step a regression tree was used to obtain an initial classification of homogeneous biomass groups, and multiple linear regression models were then fitted to each node of the pruned regression tree. Cross-validation of the hybrid model explained 72.96% of the observed stand biomass variation, with a reduction in the RMSE of 25.47% with respect to the estimates yielded by the linear model fitted to the complete database. The most important variables for the binary classification process in the regression tree were the albedo, the corrected readings of the short-wave infrared band of the satellite (2.08-2.35 µm and the topographic moisture index. We used the model output to construct a map for estimating biomass in the study area, which yielded values of between 51 and 235 Mg ha-1. The use of regression trees in combination with stepwise regression of corrected satellite imagery proved a reliable method for estimating forest biomass.

  12. Age estimates for an adaptive lake fish radiation, its mitochondrial introgression, and an unexpected sister group: Sailfin silversides of the Malili Lakes system in Sulawesi

    Science.gov (United States)

    2014-01-01

    Background The Malili Lakes system in central Sulawesi (Indonesia) is a hotspot of freshwater biodiversity in the Wallacea, characterized by endemic species flocks like the sailfin silversides (Teleostei: Atherinomorpha: Telmatherinidae) radiation. Phylogenetic reconstructions of these freshwater fishes have previously revealed two Lake Matano Telmatherina lineages (sharpfins and roundfins) forming an ancient monophyletic group, which is however masked by introgressive hybridization of sharpfins with riverine populations. The present study uses mitochondrial data, newly included taxa, and different external calibration points, to estimate the age of speciation and hybridization processes, and to test for phylogeographic relationships between Kalyptatherina from ancient islands off New Guinea, Marosatherina from SW Sulawesi, and the Malili Lakes flock. Results Contrary to previous expectations, Kalyptatherina is the closest relative to the Malili Lakes Telmatherinidae, and Marosatherina is the sister to this clade. Palaeogeographic reconstructions of Sulawesi suggest that the closer relationship of the Malili Lakes radiation to Kalyptatherina might be explained by a 'terrane-rafting’ scenario, while proto-Marosatherina might have colonized Sulawesi by marine dispersal. The most plausible analysis conducted here implies an age of c. 1.9 My for the onset of divergence between the two major clades endemic to Lake Matano. Diversification within both lineages is apparently considerably more recent (c. 1.0 My); stream haplotypes present in the sharpfins are of even more recent origin (c. 0.4 My). Conclusions Sulawesi’s Telmatherinidae have most likely originated in the Sahul Shelf area, have possibly reached the island by both, marine dispersal and island/terrane-rafting, and have colonized the Malili Lakes system from rivers. Estimates for the split between the epibenthic sharpfins and the predominantly pelagic to benthopelagic roundfins in Lake Matano widely

  13. ESTIMATED DAILY AVERAGE PER CAPITA WATER INGESTION BY CHILD AND ADULT AGE CATEGORIES BASED ON USDA'S 1994-96 AND 1998 CONTINUING SURVEY OF FOOD INTAKES BY INDIVIDUALS (JOURNAL ARTICLE)

    Science.gov (United States)

    Current water ingestion estimates are important for the assessment of risk to human populations of exposure to water-borne pollutants. This paper reports mean and percentile estimates of the distributions of daily average per capita water ingestion for 12 age range groups. The ...

  14. Age estimation of the mid-Pleistocene microtektite event in the South China Sea: A case showing the complexity of the sea-land correlation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The present study confirms the stratigraphical position of microtektite layer being clearly located below the Brunhes/Matuyama (B/M) boundary. Based on the sedimentation rate derived from the stable isotopic and magnetic data of ODP Site 772A, cores 17957 and 17959 in the South China Sea, the age of the mid-Pleistocene impact event was estimated at 10-12 ka earlier than the Brunhes-Matuyama polarity reversal. However, the microtektites were found above the measured B/M boundary in the loess profile due to the downward deviation of the measured B/M boundary from its true position[1] . This demonstrates the complexity of paleo-magnetic records in the loess profiles which, in turn, causes the confusion in the sea-land stratigraphic correlation.

  15. Nuclear knowledge drawn from the study of the Oklo phenomenon. Estimation of the age and life of the reactions. Study of the migration of fission products

    International Nuclear Information System (INIS)

    The natural fossile reactors of Oklo (Gabon), preserved almost intact for two billion years, represent a field of investigation which is extremely useful and, up to now, unique. The operation of these reactors has deeply transformed the chemical and isotopic composition of the minerals existing in the reaction zones. The chemical and isotopic analysis of the fission products is possible for the first time after the complete decay of the radioactive isotopes. The methods applied or specially developed to estimate the age and life of the nuclear reactions are described. The study of uranium and fission product distribution in the reaction zones enables the migration of fission products stored in sedimentary soils for 1800 million years to be determined

  16. Psychohygienic estimation of features of the formation of properties of character of pupils aged 14-17 years in the dynamics of learning at modern schools

    Directory of Open Access Journals (Sweden)

    Serheta I.V.

    2013-10-01

    Full Text Available The aim of scientific work was psychohygienic estimation of features of the formation of properties of character of pupils aged 14-17 years old in the dynamics of learning at modern schools. The studies were conducted on the basis of secondary schools in the city of Vinnitsya. Evaluation of the formation of properties of character was carried out using a personality questionnaire Mini-mult. It was determined that in the structure of personal profile of properties of character in girls aged 14-17 years during the period of study at school predominance of characterologic features according to schizoid scales (Se and pscychasthenia (Pt (block 1 of characterologic features, hypochondria (Hs and depression (D (block 2 of characterologic features, hypomania (Ma and hysteria (Hy (block 3 of characterologic features is registered. In the structure of personal profile of properties of character of boys of 14-17 years during the period of study at school predominance of characterologic properties according to psychasthenia (Pt and schizoid (Se (block 1 of characterologic features, hypochondria (Hs and depression (D (block 2, paranoid (Pa and hypomania (Ma (block 3 is registered. The results suggest the need to consider the properties of character of schoolchildren in development of health-saving technologies, sanitation measures and psychohygienic effect on the pupils’ organism.

  17. Impact of gender and healthy aging on pulmonary capillary wedge pressure estimated by the kinetics-tracking index using two-dimensional speckle tracking echocardiography.

    Science.gov (United States)

    Kawasaki, Masanori; Tanaka, Ryuhei; Ono, Koji; Minatoguchi, Shingo; Watanabe, Takatomo; Arai, Masazumi; Nishigaki, Kazuhiko; Noda, Toshiyuki; Watanabe, Sachiro; Minatoguchi, Shinya

    2016-05-01

    Risk stratification in heart failure (HF) among patients and healthy subjects using pulmonary capillary wedge pressure (PCWP) is important for understanding when and why HF develops. The aim of the present study was to evaluate the impact of gender and healthy aging on estimated PCWP using a kinetics-tracking index in patients and in healthy subjects without hypertension. The study population consisted of 198 healthy subjects without cardiovascular or other systemic diseases and who were not taking any medications. Echocardiographic studies were performed using an ACUSON Sequoia 512 ultrasound system. Active left atrial (LA) emptying function (EF) was defined as (pre-atrial contraction LA volume-minimum LA volume)/pre-atrial contraction LA volume × 100%. With an increase in age, the E/A and E/e' ratios (markers of left ventricular (LV) diastolic dysfunction (DD)) showed a similar decrease in males and females. PCWP was maintained at 8.3±1.8 mm Hg in males and 8.2±2.3 mm Hg in females because of compensation by an increase in active LA EF. In contrast, the compensation for LV DD with an increase in active LA EF in females tended to be more gradual (slope=0.11) than in males (slope=0.18, P=0.060 vs. female). The parameters that indicated LV DD deteriorated with advancing age. PCWP might be maintained because of compensation, namely an increase in active LA EF in both males and females. The compensation in female septuagenarians and octogenarians was weaker than in male septuagenarians and octogenarians. This difference in compensation may explain why HF with preserved LV ejection fraction occurs more frequently in females than in males. PMID:26791012

  18. Triglyceride levels are closely associated with mild declines in estimated glomerular filtration rates in middle-aged and elderly Chinese with normal serum lipid levels.

    Directory of Open Access Journals (Sweden)

    Xinguo Hou

    Full Text Available OBJECTIVE: To investigate the relationship between lipid profiles [including total cholesterol (TC, triglyceride (TG, low-density lipoprotein cholesterol (LDL-C and high-density lipoprotein cholesterol (HDL-C] and a mild decline in the estimated glomerular filtration rate (eGFR in subjects with normal serum lipid levels. DESIGN AND METHODS: In this study, we included 2647 participants who were ≥ 40 years old and had normal serum lipid levels. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI equation was used to estimate the GFR. A mildly reduced eGFR was defined as 60-90 mL/min/1.73 m(2. First, multiple linear regression analysis was used to estimate the association of lipid profiles with the eGFR. Then, the levels of each lipid component were divided into four groups, using the 25th, 50th and 75th percentiles as cut-off points. Finally, multiple logistic regression analysis was used to investigate the association of different lipid components with the risk of mildly reduced eGFR. RESULTS: In the group with a mildly reduced eGFR, TG and LDL-C levels were significantly increased, but HDL-C levels were significantly decreased. After adjusting for age, gender, body mass index (BMI, systolic blood pressure (SBP, glycated hemoglobin (HbA1c, smoking and drinking, only TC and TG were independently related to the eGFR. Additionally, only TG showed a linear relationship with an increased risk of a mildly reduced eGFR, with the highest quartile group (TG: 108-150 mg/dl [1.22-1.70 mmol/L] having a significantly increased risk after adjusting for the above factors. CONCLUSIONS: Triglyceride levels are closely associated with a mildly reduced eGFR in subjects with normal serum lipid levels. Dyslipidemia with lower TG levels could be used as new diagnostic criteria for subjects with mildly reduced renal function.

  19. Application of hydrogeology and groundwater-age estimates to assess the travel time of groundwater at the site of a landfill to the Mahomet Aquifer, near Clinton, Illinois

    Science.gov (United States)

    Kay, Robert T.; Buszka, Paul M.

    2016-01-01

    The U.S. Geological Survey used interpretations of hydrogeologic conditions and tritium-based groundwater age estimates to assess the travel time of groundwater at a landfill site near Clinton, Illinois (the “Clinton site”) where a chemical waste unit (CWU) was proposed to be within the Clinton landfill unit #3 (CLU#3). Glacial deposits beneath the CWU consist predominantly of low-permeability silt- and clay-rich till interspersed with thin (typically less than 2 feet in thickness) layers of more permeable deposits, including the Upper and Lower Radnor Till Sands and the Organic Soil unit. These glacial deposits are about 170 feet thick and overlie the Mahomet Sand Member of the Banner Formation. The Mahomet aquifer is composed of the Mahomet Sand Member and is used for water supply in much of east-central Illinois.Eight tritium analyses of water from seven wells were used to evaluate the overall age of recharge to aquifers beneath the Clinton site. Groundwater samples were collected from six monitoring wells on or adjacent to the CLU#3 that were open to glacial deposits above the Mahomet aquifer (the upper and lower parts of the Radnor Till Member and the Organic Soil unit) and one proximal production well (approximately 0.5 miles from the CLU#3) that is screened in the Mahomet aquifer. The tritium-based age estimates were computed with a simplifying, piston-flow assumption: that groundwater moves in discrete packets to the sampled interval by advection, without hydrodynamic dispersion or mixing.Tritium concentrations indicate a recharge age of at least 59 years (pre-1953 recharge) for water sampled from deposits below the upper part of the Radnor Till Member at the CLU#3, with older water expected at progressively greater depth in the tills. The largest tritium concentration from a well sampled by this study (well G53S; 0.32 ± 0.10 tritium units) was in groundwater from a sand deposit in the upper part of the Radnor Till Member; the shallowest permeable unit

  20. Heritability estimates for the constitutional levels of the collectins mannan-binding lectin and lung surfactant protein D. A study of unselected like-sexed mono- and dizygotic twins at the age of 6-9 years

    DEFF Research Database (Denmark)

    Husby, Steffen; Herskind, Anne Maria; Jensenius, Jens Christian;

    2002-01-01

    . Structural variants are also known for SP-D but these have not been linked to disease states. The aim of the present study was to provide heritability estimates for the constitutional levels of MBL and SP-D in children. A population of 26 monozygotic (MZ) and 36 dizygotic (DZ) like-sexed twin pairs aged 6...

  1. Age and Farmer Productivity

    OpenAIRE

    Tauer, Loren W.

    1994-01-01

    Farmer productivity by age was estimated, allowing for differences because of efficiency and returns to scale. Using Census of Agriculture data, estimates vary by state, but returns to scale average 1.07. Efficiency increases average 4.5 percent every ten years of age, to the age interval 35 to 44, and then decreases at that same rate.

  2. Age estimations of wild pallid sturgeon (Scaphirhynchus albus, Forbes & Richardson 1905) based on pectoral fin spines, otoliths and bomb radiocarbon: inferences on recruitment in the dam-fragmented Missouri River

    Science.gov (United States)

    Braaten, P. J.; Campana, S. E.; Fuller, D. B.; Lott, R. D.; Bruch, R. M.; Jordan, G. R.

    2015-01-01

    An extant stock of wild pallid sturgeon Scaphirhynchus albus persists in the fragmented upper Missouri River basin of Montana and North Dakota. Although successful spawning and hatch of embryos has been verified, long-term catch records suggest that recruitment has not occurred for several decades as the extant stock lacks juvenile size classes and is comprised exclusively of large, presumably old individuals. Ages of 11 deceased (death years 1997–2007) wild S. albus (136–166 cm fork length) were estimated based on pectoral fin spines, sagittal otoliths and bomb radiocarbon (14C) assays of otoliths to test the hypothesis that members of this stock are old and to provide inferences on recruitment years that produced the extant stock. Age estimations based on counts of presumed annuli were about 2 years greater for otoliths (mean = 51 years, range = 43–57 years) than spines (mean = 49 years, range = 37–59 years). Based on 14C assays, confirmed birth years for all individuals occurred prior to 1957, thus establishing known longevity of at least 50 years. Estimated age based on presumed otolith annuli for one S. albus was validated to at least age 49. Although 14C assays confirmed pre-1957 birth years for all S. albus, only 56% of estimated ages from spines and 91% of estimated ages from otoliths depicted pre-1957 birth years. Both ageing structures were subject to under-ageing error (up to 15 years). Lack of or severe curtailment of S. albus recruitment in the upper Missouri River basin since the mid-1950s closely parallels the 1953–1957 timeframe when a mainstem reservoir was constructed and started to fill. This reservoir may function as a system-wide stressor to diminish recruitment success of S. albus in the upper Missouri River basin.

  3. Geochronology of cave deposits at Liang Bua and of adjacent river terraces in the Wae Racang valley, western Flores, Indonesia: a synthesis of age estimates for the type locality of Homo floresiensis.

    Science.gov (United States)

    Roberts, R G; Westaway, K E; Zhao, J-x; Turney, C S M; Bird, M I; Rink, W J; Fifield, L K

    2009-11-01

    A robust timeframe for the extant cave deposits at Liang Bua, and for the river terraces in the adjoining Wae Racang valley, is essential to constrain the period of existence and time of extinction of Homo floresiensis and other biota that have been excavated at this hominin type locality. Reliable age control is also required for the variety of artifacts excavated from these deposits, and to assist in environmental reconstructions for this river valley and for the region more broadly. In this paper, we summarize the available geochronological information for Liang Bua and its immediate environs, obtained using seven numerical-age methods: radiocarbon, thermoluminescence, optically- and infrared-stimulated luminescence (collectively known as optical dating), uranium-series, electron spin resonance, and coupled electron spin resonance/uranium-series. We synthesize the large number of numerical age determinations reported previously and present additional age estimates germane to questions of hominin evolution and extinction. PMID:19254806

  4. Wages, productivity and aging

    OpenAIRE

    Dostie, Benoît

    2006-01-01

    In this article, we estimate age based wage and productivity differentials using linked employer-employee Canadian data from the Workplace and Employee Survey 1999-2003. Data on the firm side is used to estimate production functions taking into account the age profile of the firm's work-force. Data on the workers' side is used to estimate wage equations that also depend on age. Results show concave age-wage and age-productivity profiles. Wage-productivity comparisons show that the productivit...

  5. Change point-cure models with application to estimating the change-point effect of age of diagnosis among prostate cancer patients

    OpenAIRE

    Othus, Megan; Li, Yi; Tiwari, Ram

    2012-01-01

    Previous research on prostate cancer survival trends in the United States National Cancer Institute’s Surveillance Epidemiology and End Results database has indicated a potential change-point in the age of diagnosis of prostate cancer around age 50. Identifying a change-point value in prostate cancer survival and cure could have important policy and health care management implications. Statistical analysis of this data has to address two complicating features: (1) change-point models are not ...

  6. Preliminary Data on Age Estimation and Body Size of the Dwarf Lizard, Parvilacerta parva (Boulenger, 1887 (Reptilia: Lacertilia from Akşehir, Konya (Turkey

    Directory of Open Access Journals (Sweden)

    Batuhan Yaman Yakin

    2012-07-01

    Full Text Available In this study, age determination was done by using the skeletochronology method on Akşehir, Konya (Turkey, 14 (5♂♂; 9♀♀ Parvilacerta parva specimens. Cross-sections of femurs were examined in total 14 individuals, the lowest number of LAGs was seen in one female and one male individuals as 4, the highest number of LAGs were seen in two female individuals as 8. Average SVL was found 50.8 mm (SD=2.27 in male individuals, and 53.1 mm (SD = 3.27 in females. For all the samples, the age-length equation was calculated as SVL (mm = 37.82 + (2.47 * age. As a result of Pearson correlation analysis, a significant positive correlation (r=0.93, P˂0.01 between age and SVL. Pileus length does not increase constantly with age (r=0.007, P=0.98, while pileus width increases normally together with age (r=0.212, P=0.46.

  7. Estimation of aerosol radiative forcing over an aged-background aerosol feature during advection and non-advection events using a ground-based data obtained from a Prede Skyradiometer observation

    Science.gov (United States)

    Ningombam, Shantikumar S.; Bagare, S. P.; Khatri, P.; Sohn, B. J.; Song, H.-J.

    2015-10-01

    Estimation of aerosol radiative forcing (ARF) was performed using a radiative transfer model (Rstar6b) along with physical and optical parameters of aerosols obtained from sky radiometer observation over Indian Astronomical Observatory (IAO), Hanle, Ladakh, during 2008-2010 from dust, anthropogenic, and aged background observing conditions. ARF was estimated at the top of the atmosphere (TOA), in the atmosphere, and at the surface during the three observing conditions. During dust and anthropogenic events, average aerosol optical depth (AOD at 500 nm) went up to 0.24 from the aged background observing condition 0.04. Such enhancement of AOD is associated by the combination of desert-dust and anthropogenic aerosols transported from distant sources as noticed from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Such three types of aerosols are also identified from the observed properties of single scattering albedo (SSA), aerosol asymmetry (AS) parameter, and aerosol size distribution. The estimated ARFs at TOA, at the surface, and in atmosphere are - 3.73, - 6.82, and 3.40 Wm- 2, respectively during the dust advection period. On the contrary, the respective ARFs during the aged background observing condition are - 1.50, - 2.22, and 0.70 Wm- 2, respectively. A significant difference of spectral AOD is observed during dust, anthropogenic, and aged background observing conditions. Ångström exponent (AE) decreases from 1.05 in the aged background observing condition to 0.40 in the dust event. A significant difference of coarse-fine mode volume distribution is also observed between the dust and the anthropogenic cases. Further, the study reveals high aerosols induced during the dust and the anthropogenic episodes caused warming at atmosphere and cooling at surface which collectively may affect the local atmospheric circulation.

  8. The Need to Provide for Security in Old Age in Hierarchy of Needs-An Estimation of Its Ranking within the Polish Population

    Science.gov (United States)

    Roszkiewicz, Malgorzata

    2004-01-01

    The results of studies conducted in the last 5 years in Poland formed the basis for the assumption that amongst many needs an individual or a Polish household seeks to satisfy, the need to provide for security in old age takes a prominent position. Determining the position of this need among other needs as defined in Schrab's classification…

  9. Re-evaluation of Pleistocene and Holocene long bone robusticity trends with regards to age-at-death estimates and size standardization procedures.

    Science.gov (United States)

    Friedl, Lukáš; Eisová, Stanislava; Holliday, Trenton W

    2016-08-01

    Long-term trends in robusticity of lower limb bones in the genus Homo through the Pleistocene until the present have been proposed, which have been interpreted as a consequence of decreasing levels of mobility and activity patterns, changes in lifestyle, and environmental factors. There has also long been evidence that skeletal strength increases over an individual's lifespan. This increase is caused by continuous bone remodeling that optimizes the structure of a bone to resist mechanical loadings and creates a balance between endosteal resorption and subperiosteal apposition. However, none of the previous studies of temporal trends in robusticity has considered both processes and analyzed how individual age-related robusticity might influence higher-level temporal trends. This paper therefore explores temporal trends in robusticity of lower limb long bones within the genus Homo and considers how individual ages-at-death can confound published evolutionary trends, given the fact that some aspects of relative bone strength tend to increase over individual lifespans. Cross-sectional diaphyseal properties of the midshaft and proximal femur and midshaft tibia of Pleistocene and early Holocene individuals, together with data on age-at-death are used to analyze changes in relative bone strength relative to individuals' ages and evolutionary time. The results show increasing bone strength in adulthood until the fourth decade and then a slight decrease, an observation that conforms to previously published results on recent human populations. However, no significant impact of age-at-death on the trends along an evolutionary trajectory has been detected. The evolutionary trends in femoral and tibial relative strength can be described as fluctuating, probably as a consequence of changing mobility patterns, environmentally and technologically influenced behaviors, and demographic processes. The differences between evolutionary trends published in several studies are explained

  10. Estimation of salivary flow rate, pH, buffer capacity, calcium, total protein content and total antioxidant capacity in relation to dental caries severity, age and gender

    Directory of Open Access Journals (Sweden)

    Pallavi Pandey

    2015-01-01

    Full Text Available Purpose: The aim of the study was to evaluate salivary flow rate, pH, buffering capacity, calcium, total protein content and total antioxidant capacity in relation to dental caries, age and gender. Materials and Methods: The study population consisted of 120 healthy children aged 7-15 years that was further divided into two groups: 7-10 years and 11-15 years. In this 60 children with DMFS/dfs = 0 and 60 children with DMFS/dfs ≥5 were included. The subjects were divided into two groups; Group A: Children with DMFS/dfs = 0 (caries-free Group B: Children with DMFS/dfs ≥5 (caries active. Unstimulated saliva samples were collected from all groups. Flow rates were determined, and samples analyzed for pH, buffer capacity, calcium, total protein and total antioxidant status. Salivary antioxidant activity is measured with spectrophotometer by an adaptation of 2,2′-azino-di-(3-ethylbenzthiazoline-6-sulphonate assays. Results: The mean difference of the two groups; caries-free and caries active were proved to be statistically significant (P < 0.05 for salivary calcium, total protein and total antioxidant level for both the sexes in the age group 7-10 years and for the age 11-15 years the mean difference of the two groups were proved to be statistically significant (P < 0.05 for salivary calcium level for both the sexes. Salivary total protein and total antioxidant level were proved to be statistically significant for male children only. Conclusions: In general, total protein and total antioxidants in saliva were increased with caries activity. Calcium content of saliva was found to be more in caries-free group and increased with age.

  11. Estimating the lifetime economic burden of stroke according to the age of onset in South Korea: a cost of illness study

    OpenAIRE

    Suh Hae Sun; Lim Seung-Ji; Kang Hye-Young; Liew Danny

    2011-01-01

    Abstract Background The recently-observed trend towards younger stroke patients in Korea raises economic concerns, including erosion of the workforce. We compared per-person lifetime costs of stroke according to the age of stroke onset from the Korean societal perspective. Methods A state-transition Markov model consisted of three health states ('post primary stroke event', 'alive post stroke', and 'dead') was developed to simulate the natural history of stroke. The transition probabilities f...

  12. Methods of estimating the state of the mechanisms of regulation of cardiac activity for girls 9-10 years of age during physical training aimed at developing endurance

    OpenAIRE

    Samokih I.I.

    2012-01-01

    Are considered indicators of regulation of cardiac activity proposed D.N. Davidenko et al. (1984). It is established age-related indicators in girls from 9 to 10 years. It is shown that in the process of double-entry physical training with the implementation of priority endurance exercise significantly improves the efficiency of regulation of cardiac activity for girls. The expediency of the lessons of physical culture directed on the priority of development endurance to improve the physical ...

  13. Structural performance evaluation on aging underground reinforced concrete structures. Part 6. An estimation method of threshold value in performance verification taking reinforcing steel corrosion

    International Nuclear Information System (INIS)

    This paper discusses applicability of material degradation model due to reinforcing steel corrosion for RC box-culverts with corroded reinforcement and an estimation method for threshold value in performance verification reflecting reinforcing steel corrosion. First, in FEM analyses, loss of reinforcement section area and initial tension strain arising from reinforcing steel corrosion, and deteriorated bond characteristics between reinforcement and concrete were considered. The full-scale loading tests using corroded RC box-culverts were numerically analyzed. As a result, the analyzed crack patterns and load-strain relationships were in close agreement with the experimental results within the maximum corrosion ratio 15% of primary reinforcement. Then, we showed that this modeling could estimate the load carrying capacity of corroded RC box-culverts. Second, a parametric study was carried out for corroded RC box culverts with various sizes, reinforcement ratios and levels of steel corrosion, etc. Furthermore, as an application of analytical results and various experimental investigations, we suggested allowable degradation ratios for a modification of the threshold value, which corresponds to the chloride induced deterioration progress that is widely accepted in maintenance practice for civil engineering reinforced concrete structures. Finally, based on these findings, we developed two estimation methods for threshold value in performance verification: 1) a structural analysis method using nonlinear FEM included modeling of material degradation, 2) a practical method using a threshold value, which is determined by structural analyses of RC box-culverts in sound condition, is multiplied by the allowable degradation ratio. (author)

  14. The estimation of exposure to food packaging materials. 2. Patterns of intakes of packaged foods in Irish Children aged 5-12 years.

    OpenAIRE

    Duffy, Edel; Hearty, Aine; Flynn, Albert; McCarthy, Sinéad; Gibney, Michael

    2006-01-01

    Abstract Many assumptions are employed to calculate the intake of a food packaging migrant in the EU. However very little is known about the actual intake of packaged food, the type of this food and also the type of packaging used for this food. The objective of the present study was to examine intakes of packaged food in children aged 5-12 years, to provide information on the types of food that are packaged and the type of packaging used. To do this a food consumption database, wh...

  15. New age estimations for the western outer city wall of ancient Tayma (NW Saudi Arabia) based on OSL and radiocarbon data and geomorphologic evidence

    Science.gov (United States)

    Engel, M.; Klasen, N.; Brückner, H.; Eichmann, R.; Hausleiter, A.; Al-Najem, M. H.; Al-Said, S. F.; Schneider, P. I.

    2009-04-01

    Since 2004 tremendous progress has been achieved in deciphering the cultural genesis of the Tayma oasis (NW Saudi Arabia), due to the joint investigations of the German Archaeological Institute Berlin (DAI), the General Commission for Tourism and Antiquities, Kingdom of Saudi Arabia, and the Department of Archaeology and Epigraphy, King Saud University Riyadh. Nevertheless, archaeological research is still suffering from a lacking locally-based absolute chronology of buildings. The pattern of ancient constructions at Tayma is dominated by a prominent city wall system surrounding the ancient town center (Qraya) and stretching 15 km around the oasis. Its internal structure indicates several building periods, i.e. phases of wall modification or extension of the entire system. So far, according to silex and carnelian fragments included in the mud bricks and a previous 14C age of charcoal remains from the central excavation district (wall section at Area A), an initial construction date of the wall between the late 3rd and the early 2nd millennium BC seemed likely. At the excavated western outer city wall a new systematic dating approach - combining the optically stimulated luminescence (OSL) and 14C methods - has been applied to generate a reliable age for the oldest branch of the wall system which nowadays is covered by aeolian sand. The dune deposit is genetically related to the existence of the wall and, therefore, dating its accumulation provides termini ante quem for the construction of the wall. Five OSL dates were generated from the dune deposit providing ages between 4,900 and 3,500 yrs. Two radiocarbon ages support the dating sequence and also contribute to its consistency. By combining the results with geomorphologic evidence we draw the following conclusions: Initial settlement activities at Qraya were accompanied by a regulation of wadi dynamics and the construction of the outer city wall, indicated by the abrupt boundary between the pre-settlement alluvial

  16. Methods of estimating the state of the mechanisms of regulation of cardiac activity for girls 9-10 years of age during physical training aimed at developing endurance

    Directory of Open Access Journals (Sweden)

    Samokih I.I.

    2012-02-01

    Full Text Available Are considered indicators of regulation of cardiac activity proposed D.N. Davidenko et al. (1984. It is established age-related indicators in girls from 9 to 10 years. It is shown that in the process of double-entry physical training with the implementation of priority endurance exercise significantly improves the efficiency of regulation of cardiac activity for girls. The expediency of the lessons of physical culture directed on the priority of development endurance to improve the physical health of school girls of primary school.

  17. Utilidad de la radiografía panorámica dental digital en la estimación de la edad en adultos Usefulness of dental digital panoramic radiography in the estimation of age in adults

    Directory of Open Access Journals (Sweden)

    M.I. Landa

    2008-04-01

    Full Text Available La estimación de la edad constituye un campo de creciente interés dentro de la Medicina Forense. La cuantificación de la reducción de las dimensiones de la cavidad pulpar como consecuencia del proceso de depósito de la dentina secundaria a lo largo de la vida podría servir como un posible indicador de edad. Este fenómeno además de mediante técnicas morfológicas, puede ser analizado mediante la utilización de diferentes técnicas radiográficas. El objetivo principal de este estudio consistió en evaluar la reproducibilidad del método original de cálculo de edad dental desarrollado por Kvaal et al. sobre radiografías panorámicas digitales dentales así como analizar la aplicación de las fórmulas de estimación de edad dental propuestas. Fueron seleccionadas al azar 100 ortopantomografías digitales obtenidas de pacientes de una clínica de Bilbao de edades comprendidas entre 14 y 60 años. En cada ortopantomografía fueron estudiados tres dientes mandibulares siguiendo la metodología ya descrita. Los resultados obtenidos no confirmaron la reproducibilidad del método desarrollado por Kvaal et al. sobre radiografía digital directa. Los valores tan extremos obtenidos en la estimación de la edad mediante la aplicación de las fórmulas de regresión analizadas sobre las radiografías digitales de esta serie de estudio desaconsejan su aplicación en poblaciones similares a la serie analizada.Estimation of age in individuals has received considerable attention in the forensic literature. The reduction of size of dental pulp cavity as a result of secondary dentin deposit with increasing age could be used as an indicator of age. This regression change, apart from morphological techniques, can also be analysed by radiological techniques. The aim of this work was to evaluate the reproducibility of the original method of Kvaal et al. on digital panoramic radiographs as well as to analyse the application of age estimation formulae

  18. EVOLUTION OF CHEMICAL CONDITIONS AND ESTIMATED SOLUBILITY CONTROLS ON RADIONUCLIDES IN THE RESIDUAL WASTE LAYER DURING POST-CLOSURE AGING OF HIGH-LEVEL WASTE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    Denham, M.; Millings, M.

    2012-08-28

    This document provides information specific to H-Area waste tanks that enables a flow and transport model with limited chemical capabilities to account for varying waste release from the tanks through time. The basis for varying waste release is solubilities of radionuclides that change as pore fluids passing through the waste change in composition. Pore fluid compositions in various stages were generated by simulations of tank grout degradation. The first part of the document describes simulations of the degradation of the reducing grout in post-closure tanks. These simulations assume flow is predominantly through a water saturated porous medium. The infiltrating fluid that reacts with the grout is assumed to be fluid that has passed through the closure cap and into the tank. The results are three stages of degradation referred to as Reduced Region II, Oxidized Region II, and Oxidized Region III. A reaction path model was used so that the transitions between each stage are noted by numbers of pore volumes of infiltrating fluid reacted. The number of pore volumes to each transition can then be converted to time within a flow and transport model. The bottoms of some tanks in H-Area are below the water table requiring a different conceptual model for grout degradation. For these simulations the reacting fluid was assumed to be 10% infiltrate through the closure cap and 90% groundwater. These simulations produce an additional four pore fluid compositions referred to as Conditions A through D and were intended to simulate varying degrees of groundwater influence. The most probable degradation path for the submerged tanks is Condition C to Condition D to Oxidized Region III and eventually to Condition A. Solubilities for Condition A are estimated in the text for use in sensitivity analyses if needed. However, the grout degradation simulations did not include sufficient pore volumes of infiltrating fluid for the grout to evolve to Condition A. Solubility controls for use

  19. Karakteristik Morfologi, Perbedaan Jenis Kelamin, dan Pendugaan Umur Burung Weris (Gallirallus philippensis) di Minahasa, Sulawesi Utara (MORPHOLOGICAL CHARACTERISTICS, SEX DIFFERENCES, AND AGE ESTIMATION OF WERIS (GALLIRALLUS PHILIPPENSIS) FROM MINAHASA

    OpenAIRE

    Lucia Johana Lambey; Ronny Rachman Noor; Wasmen Manalu; Dedy Duryadi

    2013-01-01

    This study aim  to observeb Gallirallus philippensis  similarities between different sites in Minahasa,to detect sexual dimorphism, and to estimate the bird age based on morphological characteristics.  A totalof 35 birds  were collected  from four locations i.e. Tondano, Papontolan, Ranoyapo, and Wusa in MinahasaNorth Sulawesi.   The result showed that there were no differences in the length  of beak, wing, and shankbetween  birds from  the different locations.  Moreover, based on the Princip...

  20. Image quality and age-specific dose estimation in head and chest CT examinations with organ-based tube-current modulation.

    Science.gov (United States)

    Yamauchi-Kawaura, C; Yamauchi, M; Imai, K; Ikeda, M; Aoyama, T

    2013-12-01

    The purpose of this study was to investigate the effects of an organ-based tube-current modulation (OBTCM) system on image quality and age-specific dose in head and chest CT examinations. Image noise, contrast-to-noise ratio (CNR) and image entropy were assessed using statistical and entropy analyses. Radiation doses for newborn, 6-y-old child and adult phantoms were measured with in-phantom dosimetry systems. The quality of CT images obtained with OBTCM was not different from that obtained without OBTCM. In head CT scans, the eye lens dose decreased by 20-33 % using OBTCM. In chest CT scans, breast dose decreased by 5-32 % using OBTCM. Posterior skin dose, however, increased by 11-20 % using OBTCM in head and chest CT scans. The reduction of effective dose using OBTCM was negligibly small. Detailed image quality and dose information provided in this study can be effectively used for OBTCM application. PMID:23734058

  1. Physical maturation, life-history classes and age estimates of free-ranging western gorillas--insights from Mbeli Bai, Republic of Congo.

    Science.gov (United States)

    Breuer, Thomas; Hockemba, Mireille Breuer-Ndoundou; Olejniczak, Claudia; Parnell, Richard J; Stokes, Emma J

    2009-02-01

    Physical maturation and life-history parameters are seen as evolutionary adaptations to different ecological and social conditions. Comparison of life-history patterns of closely related species living in diverse environments helps to evaluate the validity of these assumptions but empirical data are lacking. The two gorilla species exhibit substantial differences in their environment, which allows investigation into the role of increased frugivory in shaping western gorilla life histories. We present behavioral and morphological data on western gorilla physical maturation and life-history parameters from a 12.5-year study at Mbeli Bai, a forest clearing in the Nouabalé-Ndoki National Park in northern Congo. We assign photographs of known individuals to different life-history classes and propose new age boundaries for life-history classes in western gorillas, which can be used and tested at other western gorilla research sites. Our results show that western gorillas are weaned at a later age compared with mountain gorillas and indicate slower physical maturation of immatures. These findings support the risk-aversion hypothesis for more frugivorous species. However, our methods need to be applied and tested with other gorilla populations. The slow life histories of western gorillas could have major consequences for social structure, mortality patterns and population growth rates that will affect recovery from population crashes of this critically endangered species. We emphasize that long-term studies can provide crucial demographic and life-history data that improve our understanding of life-history evolution and adaptation and help to refine conservation strategies. PMID:19003901

  2. Korelacija rezultata ispitivanja hemijske stabilnosti prirodno i ubrzano starenih baruta / Correlation of chemical stability estimation results of naturally and accelerated aging gun powders

    Directory of Open Access Journals (Sweden)

    Luka Grbović

    2005-09-01

    Full Text Available Praćenje sadržaja stabilizatora jedna je od savremenih i pouzdanih metoda koja se u svetu, a i kod nas, primenjuje za kontrolu kemijske stabilnosti i prognoziranje veka upotrebljivosti baruta. Radi ocene pouzdanosti metode ispitivani su uzorci prirodno starenog jednobaznog baruta tipa NC i dvobaznog baruta tipa NGB različitih godina proizvodnje. Uzorci su uzimani iz ubojnih sredstava. Određene su konstante brzine reakcije utroška stabilizatora i vremena upotrebljivosti baruta. Ove vrednosti upoređene su sa analognim rezultatima dobijenim za iste barute pre dvadeset godina pri čemu je utvrđeno zadovoljavajuće slaganje kako za prirodno tako i ubrzano starenje. Pored toga, utvrđeno je da NC baruti iz dehermetizovanog pakovanja municije pokazuju znatno manju stabilnost od baruta iz originalnog pakovanja. / Monitoring the content of the stabilizer is one of the most reliable and modern methods used all over the world as well as in our country for chemical stability control and shelf life prediction of gun powders. For reliability rating of the used method, there has been examined samples of naturally aged single-based gun powder NC type and double-based gun powder NGB type all manufactured in different years. The samples were taken from explosive ordnance. Reaction rates constants of stabilizer consumption and shelf life of gun powders have been determined. These values were compared to analog results taken for the same gun powders tested 20 years ago. Satisfactory agreement either for naturally or accelerating aging gun powders has been confirmed. Beside that, it was determined that NC gun powder from non hermetic munitions cases proved to be considerably less stable than the originally packed NC gun powder.

  3. Longevity of Atlantic Sharpnose Sharks Rhizoprionodon terraenovae and Blacknose Sharks Carcharhinus acronotus in the western North Atlantic Ocean based on tag-recapture data and direct age estimates [v2; ref status: indexed, http://f1000r.es/4fj

    Directory of Open Access Journals (Sweden)

    Bryan S. Frazier

    2015-01-01

    Full Text Available Longevity of Rhizoprionodon terraenovae and Carcharhinus acronotus in the western North Atlantic Ocean was examined using direct age estimates from vertebral sections and tag-recapture data. Time-at-liberty ranged from 7.7-14.0 years (mean =10.1 for R. terraenovae and 10.9-12.8 years (mean =11.9 for C. acronotus. Maximum estimated longevity was determined to be 19.8 years through tag-recapture data and 18.5 years from direct age estimates for R. terraenovae and 22.8 years through tag-recapture data and 20.5 years through direct age estimates for C. acronotus. These longevity estimates represent a large increase over previous estimates and may have significant effects on analyses that depend on longevity including lifetime fecundity, mortality rates, demographic analyses and stock assessments.

  4. Online CO2 and H2 O oxygen isotope fractionation allows estimation of mesophyll conductance in C4 plants, and reveals that mesophyll conductance decreases as leaves age in both C4 and C3 plants.

    Science.gov (United States)

    Barbour, Margaret M; Evans, John R; Simonin, Kevin A; von Caemmerer, Susanne

    2016-05-01

    Mesophyll conductance significantly, and variably, limits photosynthesis but we currently have no reliable method of measurement for C4 plants. An online oxygen isotope technique was developed to allow quantification of mesophyll conductance in C4 plants and to provide an alternative estimate in C3 plants. The technique is compared to an established carbon isotope method in three C3 species. Mesophyll conductance of C4 species was similar to that in the C3 species measured, and declined in both C4 and C3 species as leaves aged from fully expanded to senescing. In cotton leaves, simultaneous measurement of carbon and oxygen isotope discrimination allowed the partitioning of total conductance to the chloroplasts into cell wall and plasma membrane versus chloroplast membrane components, if CO2 was assumed to be isotopically equilibrated with cytosolic water, and the partitioning remained stable with leaf age. The oxygen isotope technique allowed estimation of mesophyll conductance in C4 plants and, when combined with well-established carbon isotope techniques, may provide additional information on mesophyll conductance in C3 plants. PMID:26778088

  5. Estimation of 226Ra concentration in ground water around Narwapahar uranium mine, Jharkhand, India and assessment of age dependent ingestion dose to the members of the public

    International Nuclear Information System (INIS)

    Because of natural mineralization and for various mining activities, enhanced level of natural radioactivity in various matrices around a uranium mine may be expected. In the present study the distribution of 226Ra concentration was measured in ground water samples, collected within a 10 km radius around the Narwapahar uranium mine in the Singhbhum thrust belt of Jharkhand, India in 2007-2008. The 226Ra content in the ground water samples in this region was found to vary from 5.2-38.1 mBql-1 with mean 13.73 ± 7.34 mBql-1. The total mean annual ingestion dose due to intake of 226Ra through drinking water pathway to male and female adults population was estimated to be 5.19 ± 2.78 μSv y-1 and 3.79 ± 2.03 μSv y-1, respectively, which comprises simply a small fraction of the reference dose level of 100 μSv y-1 as recommended by WHO. (author)

  6. Is the Age Problem Resolved?

    Indian Academy of Sciences (India)

    Ali Akbar Navabi; Nematollah Riazi

    2003-03-01

    The cosmological, astrophysical, and nucleocosmochronological methods for estimating the age of the universe and the corresponding uncertainties are comparatively studied in the present paper.We are led to the conclusion that the newmeasurements of cosmological parameters, and the recent estimates of the age of globular clusters have led to the gradual disappearance of the age problem from the arena of modern cosmology.

  7. Aging Skin

    Science.gov (United States)

    ... email address Submit Home > Healthy Aging > Wellness Healthy Aging Aging skin More information on aging skin When it ... treated early. Return to top More information on Aging skin Read more from womenshealth.gov Varicose Veins ...

  8. Proposed Testing Procedure for Estimation of Effective Recycling Ratio of Aged Asphalt in Hot Recycling Technical Conditions%老化沥青热再生有效再生率检测方法

    Institute of Scientific and Technical Information of China (English)

    杨毅文; 马涛; 卞国剑; 金晶; 黄晓明

    2011-01-01

    基于对流传质理论分析了沥青路面热再生过程中老化沥青与新沥青、再生剂的混溶机理,认为老化沥青预热温度、再生剂扩散能力以及再生沥青混合料拌和时间是影响老化沥青有效再生率的重要因素.设计提出了能够良好模拟实际热再生工艺条件的老化沥青有效再生率检测方法,试验分析了老化沥青预热温度、再生剂添加与否、再生沥青混合料拌和时间对老化沥青有效再生率的影响.试验结果验证了所设计检测方法的可行性,据此可为老化沥青再生效果的评价以及老化沥青热再生工艺条件的设计提供有利依据.%Based on the convective mass transfer theory, the mechanism of mixing of aged asphalt, new asphalt and recycling agent in asphalt pavement hot recycling projects was studied. It was deemed that the heating temperature of aged asphalt, the diffusing capability of recycling agent and the mixing time of recycling asphalt mixture could have important influence on the effective recycling ratio of aged asphalt. Therefore , a testing procedure well simulating the real technical conditions to estimate the effective recycling ratio of aged asphalt was designed. And the influences of heating temperature of aged asphalt, using recycling agent or not and mixing time of recycling asphalt mixture on the effective recycling ratio of aged asphalt were studied. Based on the test results, the feasibility of the new testing procedure is proved. It will be helpful for the evaluation of recycling effect of aged asphalt and the design of hot recycling technical conditions.

  9. 9~12岁儿童估算策略选择的发展特点%Developmental Characteristics of Computational Estimation Strategy Choices in Children Aged 9-12

    Institute of Scientific and Technical Information of China (English)

    陈丽兰

    2012-01-01

    认知心理学家和数学教育工作者对于估算在人们日常生活中的作用已形成广泛共识.9~12岁儿童估算策略选择的发展特点有:在估算时能选择多种策略,且策略的使用频率不相同,取整使用最频繁,其次是先补偿,转换和分解策略的使用频次最小;随着问题难度的增加,估算策略选择的最佳击中率降低;随着年龄的增长,估算策略选择的个数增加,估算策略选择的最佳击中率上升;估算策略的选择不存在性别差异。%This study focused on exploring the developmental characteristics of 90 grade 46 (aged 9-12)primary students' computational estimation strategy choices through the strategies children choose to solve 24 addition and subtraction computational estimating problems. The results are as follows: (1) Children tend to choose more strategies to solve the problems and the frequency is different: rounding is the strategy that is chosen most frequently and the next is prior-compensation, but the strategies of translation and decompensation are chosen least; (2) with the increasing of difficulty in problems, the best strategy hit rate falls down and with the growing of children's age, the number of strategies and the best strategy hit rate goes up; (3) no gender differences exist in the students' computational estimation strategy choices.

  10. Comparison of age distributions estimated from environmental tracers by using binary-dilution and numerical models of fractured and folded karst: Shenandoah Valley of Virginia and West Virginia, USA

    Science.gov (United States)

    Yager, Richard M.; Plummer, L. Niel; Kauffman, Leon J.; Doctor, Daniel H.; Nelms, David L.; Schlosser, Peter

    2013-01-01

    Measured concentrations of environmental tracers in spring discharge from a karst aquifer in the Shenandoah Valley, USA, were used to refine a numerical groundwater flow model. The karst aquifer is folded and faulted carbonate bedrock dominated by diffuse flow along fractures. The numerical model represented bedrock structure and discrete features (fault zones and springs). Concentrations of 3H, 3He, 4He, and CFC-113 in spring discharge were interpreted as binary dilutions of young (0–8 years) water and old (tracer-free) water. Simulated mixtures of groundwater are derived from young water flowing along shallow paths, with the addition of old water flowing along deeper paths through the model domain that discharge to springs along fault zones. The simulated median age of young water discharged from springs (5.7 years) is slightly older than the median age estimated from 3H/3He data (4.4 years). The numerical model predicted a fraction of old water in spring discharge (0.07) that was half that determined by the binary-dilution model using the 3H/3He apparent age and 3H and CFC-113 data (0.14). This difference suggests that faults and lineaments are more numerous or extensive than those mapped and included in the numerical model.

  11. Sap flow based transpiration estimates in species-rich secondary forests of different ages in central Panama during a wet-season drought

    Science.gov (United States)

    Bretfeld, M.; Ewers, B. E.; Hall, J. S.; Ogden, F. L.

    2015-12-01

    Many landscapes that were previously covered by mature tropical forests in central Panama today comprise of a mosaic of mature forest fragments, pastures and agricultural land, and regrowing secondary forests. An increasing demand for water due to urbanization and the expansion of the Panama Canal, along with a predicted transition into a dryer climatic period necessitate a better understanding regarding the effects of land use and land use history on hydrological processes. Such knowledge, including water storage, residence times, and fluxes is essential to develop effective land management strategies and propose incentives to alter land use practices to enhance hydrological services. To quantify transpiration rates at different stages of secondary forest succession, we measured sap flow in forests growing for 8, ~25, and 80+ years since last known land use in the 15 km2 "Agua Salud" study area, located in central Panama. In each forest, we selected a subset of at least 15 individuals, representing the local tree size distribution, and recorded data from heat-ratio sap flow sensors every 30 minutes starting in February 2015. All instrumented trees were identified to species and compared to local species distributions. Basal area in the three forest types was 9.1, 10.8, and 50.2 m2 ha-1 for 8, ~25, and 80+ year old forests, respectively. Average daily transpiration was highly correlated to forest age, with highest rates in the oldest forest (3.0 to 18.2 mm ha-1 day-1), followed by intermediate (1.2 to 6.7 mm ha-1 day-1) and youngest forests (0.2 to 2.7 mm ha-1 day-1), suggesting roughly a doubling in transpiration from 8 to ~25 year old forests, despite similar basal area, and again from ~25 to 80+ year old forests. Flow rates in individual trees generally reflected the dry-to-wet season transition but behaved differently in response to the unprecedentedly dry conditions during the first half of 2015 in central Panama.

  12. SU-E-T-143: Effect of X-Ray and Cone Beam CT Reconstruction Parameters On Estimation of Bone Volume of Mice Used in Aging Research

    Energy Technology Data Exchange (ETDEWEB)

    Russ, M; Pang, M; Troen, B; Rudin, S; Ionita, C [University at Buffalo, Buffalo, NY (United States)

    2014-06-01

    Purpose: To investigate the variations in bone volume calculations in mice involved in aging research when changing cone beam micro-CT x-ray and reconstruction parameters. Methods: Mouse spines were placed on an indexed turn table that rotated 0.5° per projection and imaged by a self-built micro CT machine containing a CCD-based high-resolution x-ray detector. After the full 360° rotation data set of object images was obtained, a standard filtered back-projection cone beam reconstruction was performed. Four different kVp's between 40–70 kVp in 10kVp increments were selected. For each kVp two mAs settings were used. Each acquisition was reconstructed using two voxel sizes (12 and 25μm) and two step angles, 0.5° and 1°, respectively. A LabView program was written to determine the total bone volume contained in the mouse's total spine volume (bone plus gaps) as a measure of spine health. First, the user selected the desired 512×512 reconstruction to view the whole spine volume which was then used to select a gray-level threshold that allowed for viewing of the bone structure, then another threshold to include gaps. The program returned bone volume, bone × gap volume, and their ratio, BVF. Results: The calculated bone volume fractions were compared as a function of tube potential. Cases with 25μm slice thickness showed trials with lower kVp's had greater image contrast, which resulted in higher calculated bone volume fractions. Cases with 12μm reconstructed slice thickness were significantly noisier, and showed no clear maximum BVF. Conclusion: Using the projection images and reconstructions acquired from the micro CT, it can be shown that the micro-CT x-ray and reconstruction parameters significantly affect the total bone volume calculations. When comparing mice cohorts treated with different therapies researchers need to be aware of such details and use volumes which were acquired and processed in identical conditions.

  13. Farmer Productivity at Various Ages

    OpenAIRE

    Tauer, Loren W.

    1993-01-01

    The productivity of farmers at six different age cohorts was computed by estimating production functions using 1987 census data. The results suggest that farmers of different ages operate with slightly different technologies and use various inputs at different efficiencies. Compared with previous 1978 estimates, the productivity of middleaged farmers appears to be even greater than the productivity of younger and older farmers. The average age of U.S. farmers exceeds the age of highest produc...

  14. Karakteristik Morfologi, Perbedaan Jenis Kelamin, dan Pendugaan Umur Burung Weris (Gallirallus philippensis di Minahasa, Sulawesi Utara (MORPHOLOGICAL CHARACTERISTICS, SEX DIFFERENCES, AND AGE ESTIMATION OF WERIS (GALLIRALLUS PHILIPPENSIS FROM MINAHASA

    Directory of Open Access Journals (Sweden)

    Lucia Johana Lambey

    2013-09-01

    Full Text Available This study aim  to observeb Gallirallus philippensis  similarities between different sites in Minahasa,to detect sexual dimorphism, and to estimate the bird age based on morphological characteristics.  A totalof 35 birds  were collected  from four locations i.e. Tondano, Papontolan, Ranoyapo, and Wusa in MinahasaNorth Sulawesi.   The result showed that there were no differences in the length  of beak, wing, and shankbetween  birds from  the different locations.  Moreover, based on the Principle Component Analysis (PCAthe bird’s shank and tail’s length were the main component.  Based on cluster analysis, the birds from fourlocations had a close similarities.  The male bird’s body weight, beak length, and beak width were largercomponent to the female’s.  The bird’s age could be best predicted by their iris colour,  beak colour, feather colourof the neck and the growth of the wing feathers, respectively.

  15. Estimates and determinants of HPV non-vaccination and vaccine refusal in girls 12 to 14 y of age in Canada: Results from the Childhood National Immunization Coverage Survey, 2013.

    Science.gov (United States)

    Gilbert, Nicolas L; Gilmour, Heather; Dubé, Ève; Wilson, Sarah E; Laroche, Julie

    2016-06-01

    Since the introduction of HPV vaccination programs in Canada in 2007, coverage has been below public health goals in many provinces and territories. This analysis investigated the determinants of HPV non-vaccination and vaccine refusal. Data from the Childhood National Immunization Coverage Survey (CNICS) 2013 were used to estimate the prevalence of HPV non-vaccination and parental vaccine refusal in girls aged 12-14 years, for Canada and the provinces and territories. Multivariate logistic regression was used to examine factors associated with non-vaccination and vaccine refusal, after adjusting for potential confounders. An estimated 27.7% of 12-14 y old girls had not been vaccinated against HPV, and 14.4% of parents reported refusing the vaccine. The magnitude of non-vaccination and vaccine refusal varied by province or territory and also by responding parent's country of birth. In addition, higher education was associated with a higher risk of refusal of the HPV vaccine. Rates of HPV non-vaccination and of refusal of the HPV vaccine differ and are influenced by different variables. These findings warrant further investigation. PMID:26942572

  16. Aging Blepharoplasty

    Directory of Open Access Journals (Sweden)

    Inchang Cho

    2013-09-01

    Full Text Available In performing upper blepharoplasty in the elderly, looking younger and keeping the eyelidsharmonious with the rest of the face have to be achieved at the same time. The most importantgoal in upper blepharoplasty for aging is correcting the drooping upper eyelid skin, and inthis process, the surgeon may or may not create a double eyelid fold. The pros and cons haveto be fully discussed with the patient, but the author personally prefers creating a doublefold unless the patient refuses, because it is efficient in correcting and preventing furtherdrooping of the skin. In most patients, the brow is elevated to compensate for the droopingeyelid, and when the drooping is corrected, brow ptosis may ensue. The surgeon has to preparefor these consequences before performing the procedure, and estimate the exact amountof skin to be excised. In the elderly, the skin and the orbicularis oculi muscle is thin, with adecreased amount of subcutaneous fat and retro-orbicularis oculi fat, and in most cases,excision of the skin alone is enough to correct the deformity. Removing large portions ofsoft tissue may also prolong the recovery period. Unlike younger patients, the lower skinflap should not be stretched too much in the elderly, as it may create an aggressive lookingappearance. A few wrinkles in the lower flap should remain untouched to create a naturallook. In this article, the author’s own methods of performing an aging blepharoplasty aredescribed specifically, with a step-by-step guide and surgical tips.

  17. Interpreting spotted dolphin age distributions

    OpenAIRE

    Barlow, Jay; Hohn, Aleta A.

    1984-01-01

    Previous work has determined the age distribution from a sample of spotted dolphins (Stenella attenuata) killed in the eastern Pacific tuna purse-seine fishery. In this paper we examine the usefulness of this age distribution for estimating natural mortality rates. The observed age distribution has a deficiency of individuals from 5-15 years and cannot represent a stable age distribution. Sampling bias and errors in age interpretation are examined as possible causes of the "dip" in the obs...

  18. Rural Aging

    Science.gov (United States)

    ... Rural Health > Topics & States > Topics View more Rural Aging The nation's population is aging, and with that change comes increased healthcare needs. ... Disease Control and Prevention report, The State of Aging and Health in America 2013 , the population 65 ...

  19. Aging blepharoplasty.

    Science.gov (United States)

    Cho, Inchang

    2013-09-01

    In performing upper blepharoplasty in the elderly, looking younger and keeping the eyelids harmonious with the rest of the face have to be achieved at the same time. The most important goal in upper blepharoplasty for aging is correcting the drooping upper eyelid skin, and in this process, the surgeon may or may not create a double eyelid fold. The pros and cons have to be fully discussed with the patient, but the author personally prefers creating a double fold unless the patient refuses, because it is efficient in correcting and preventing further drooping of the skin. In most patients, the brow is elevated to compensate for the drooping eyelid, and when the drooping is corrected, brow ptosis may ensue. The surgeon has to prepare for these consequences before performing the procedure, and estimate the exact amount of skin to be excised. In the elderly, the skin and the orbicularis oculi muscle is thin, with a decreased amount of subcutaneous fat and retro-orbicularis oculi fat, and in most cases, excision of the skin alone is enough to correct the deformity. Removing large portions of soft tissue may also prolong the recovery period. Unlike younger patients, the lower skin flap should not be stretched too much in the elderly, as it may create an aggressive looking appearance. A few wrinkles in the lower flap should remain untouched to create a natural look. In this article, the author's own methods of performing an aging blepharoplasty are described specifically, with a step-by-step guide and surgical tips. PMID:24086798

  20. Variation in erosion/deposition rates over the last 50 years on alluvial fan surfaces of L. Pleistocene- Mid Holocene age, estimations using 137Cs soil profile data, Amargosa Valley, Nevada.

    Science.gov (United States)

    Harrington, C.; Kelley, R.; Ebert, T.; Delong, S.; Cline, M.; Pelletier, J.; Whitney, J.

    2005-12-01

    Variations in erosion and deposition for the last fifty years (based on estimates from 137Cs profiles) on surfaces (Late Pleistocene to Late Holocene in age) making up the Fortymile Wash alluvial fan south of Yucca Mountain, is a function of surface age and of desert pavement development or absence. For purposes of comparing erosion and deposition, the surfaces can be examined as three groups: (1) Late Pleistocene surfaces possess areas of desert pavement development with thin Av or sandy A horizons, formed by the trapping capabilities of the pavements. These zones of deposition are complemented by coppice dune formation on similar parts of the surface. Areas on the surface where no pavement development has occurred are erosional in nature with 0.0 +/- 0.0 cm to 1.5 +/- 0.5 cm of erosion occurring primarily by winds blowing across the surface. Overall these surfaces may show either a small net depositional gain or small erosional loss. (2) Early Holocene surfaces have no well-developed desert pavements, but may have residual gravel deposits in small areas on the surfaces. These surfaces show the most consistent erosional surface areas on which it ranges from1.0 +/-.01 cm to 2.0+/-.01 cm. Fewer depositional forms are found on this age of surface so there is probably a net loss of 1.5 cm across these surfaces. (3) The Late Holocene surfaces show the greatest variability in erosion and deposition. Overbank deposition during floods cover many edges of these surfaces and coppice dune formation also creates depositional features. Erosion rates are highly variable and range from 0.0 +/- 0.0 to a maximum of 2.0+/-.01. Erosion occurs because of the lack of protection of the surface. However, the common areas of deposition probably result in the surface having a small net depositional gain across these surfaces. Thus, the interchannel surfaces of the Fortymile Wash fan show a variety of erosional styles as well as areas of deposition. The fan, therefore, is a dynamic system

  1. Inconsistency of mesophyll conductance estimate causes the inconsistency for the estimates of maximum rate of Rubisco carboxylation among the linear, rectangular and non-rectangular hyperbola biochemical models of leaf photosynthesis--a case study of CO₂ enrichment and leaf aging effects in soybean.

    Science.gov (United States)

    Sun, Jindong; Feng, Zhaozhong; Leakey, Andrew D B; Zhu, Xinguang; Bernacchi, Carl J; Ort, Donald R

    2014-09-01

    The responses of CO2 assimilation to [CO2] (A/Ci) were investigated at two developmental stages (R5 and R6) and in several soybean cultivars grown under two levels of CO2, the ambient level of 370 μbar versus the elevated level of 550 μbar. The A/Ci data were analyzed and compared by either the combined iterations or the separated iterations of the Rubisco-limited photosynthesis (Ac) and/or the RuBP-limited photosynthesis (Aj) using various curve-fitting methods: the linear 2-segment model; the non-rectangular hyperbola model; the rectangular hyperbola model; the constant rate of electron transport (J) method and the variable J method. Inconsistency was found among the various methods for the estimation of the maximum rate of carboxylation (Vcmax), the mitochondrial respiration rate in the light (Rd) and mesophyll conductance (gm). The analysis showed that the inconsistency was due to inconsistent estimates of gm values that decreased with an instantaneous increase in [CO2], and varied with the transition Ci cut-off between Rubisco-limited photosynthesis and RuBP-regeneration-limited photosynthesis, and due to over-parameters for non-linear curve-fitting with gm included. We proposed an alternate solution to A/Ci curve-fitting for estimates of Vcmax, Rd, Jmax and gm with the various A/Ci curve-fitting methods. The study indicated that down-regulation of photosynthetic capacity by elevated [CO2] and leaf aging was due to partially the decrease in the maximum rates of carboxylation and partially the decrease in gm. Mesophyll conductance lowered photosynthetic capacity by 18% on average for the case of soybean plants. PMID:25113450

  2. Arterial Ageing

    OpenAIRE

    Lee, Seung-Jun; Park, Sung-Ha

    2013-01-01

    Arterial ageing is characterized by age associated degeneration and sclerosis of the media layer of the large arteries. However, besides ageing, clinical conditions, which enhance oxidative stress and inflammation act to accelerate the degree of arterial ageing. In this review, we summarized the pathophysiology and contributing factors that accelerate arterial ageing. Among them, we focused on hypertension, the renin-angiotensin-aldosterone system and vascular inflammation which are modifiabl...

  3. Parameter Estimation

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian;

    2011-01-01

    In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to...... generate a set of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  4. Skin Aging

    Science.gov (United States)

    ... too. Sunlight is a major cause of skin aging. You can protect yourself by staying out of ... person has smoked. Many products claim to revitalize aging skin or reduce wrinkles, but the Food and ...

  5. GUIDE POUR L'INTERPRÉTATION DES ÉCAILLES ET L'ESTIMATION DE L'ÂGE CHEZ LES ALOSES (ALOSA SPP. DE LA FAÇADE ATLANTIQUE-EST ET DE LA MÉDITERRANÉE-OUEST. A GUIDE TO SCALE INTERPRETATION AND AGE ESTIMATION FOR THE EAST-ATLANTIC AND WEST-MEDITERRANEAN SHADS (ALOSA SPP..

    Directory of Open Access Journals (Sweden)

    BAGLINIÈRE J. L.

    2008-05-01

    Full Text Available L'objectif général de ce guide est de fournir un manuel d'utilisation et d'interprétation des écailles pour l'estimation de l'âge chez les aloses de l'Atlantique-Est et de Méditerranée-Ouest (Grande Alose, Alose feinte atlantique et méditerranéenne. Après un présentation rapide des espèces, populations et fleuves analysés, les écailles d'aloses et les méthodes de récolte, de préparation et de montage les concernant sont décrites en détail. Des définitions et un système de notation de l'âge standards sont donnés. La grande majorité des difficultés rencontrées pour l'interprétation des écailles sont analysées en proposant des solutions et en donnant certaines recommandations. L'ensemble de ce guide est largement illustré à l'aide d'exemples d'écailles typiques et atypiques choisis chez tous les taxons des différentes populations étudiées. The general objective of this guide is to provide a practical manual for interpreting scales and the estimation of age of Alosa from the East Atlantic and West-Mediterranean (Allis shad, Atlantic and Mediterranean shad. Following a brief presentation of the species, populations and rivers studied, the scales, sampling methods and their preparation for reading are described in detail. Definitions and a standard system of notating age are given. The majority of the difficulties encountered in the interpretation of scales are analysed, solutions proposed and some recommendations given. The whole guide is largely illustrative using examples of typical and atypical scales from the various taxons of the different populations studied.

  6. Aging mechanisms

    OpenAIRE

    Takahashi, Yoshiko; Kuro-o, Makoto; Ishikawa, Fuyuki

    2000-01-01

    Aging (senescence) has long been a difficult issue to be experimentally analyzed because of stochastic processes, which contrast with the programmed events during early development. However, we have recently started to learn the molecular mechanisms that control aging. Studies of the mutant mouse, klotho, showing premature aging, raise a possibility that mammals have an “anti-aging hormone.” A decrease of cell proliferation ability caused by the telomeres is also t...

  7. Happy Aging

    Institute of Scientific and Technical Information of China (English)

    梁秉中

    2009-01-01

    Aging is a normal physiological process in human life.The decline in the ability to repair and regenerate predisposes the aging person to develop disabling problems in the cardiovascular and skeletal systems.Full awareness of aging problems and advocations on the means to prevent their occurrence are mounting.European and US groups rely on scientific,target-oriented means to treat aging manifestations. Oriental medicine aims at prevention,using nutrition and exercise to maintain internal harmony.

  8. Population Aging

    OpenAIRE

    Weil, David N.

    2006-01-01

    Population aging is primarily the result of past declines in fertility, which produced a decades long period in which the ratio of dependents to working age adults was reduced. Rising old-age dependency in many countries represents the inevitable passing of this %u201Cdemographic dividend.%u201D Societies use three methods to transfer resources to people in dependent age groups: government, family, and personal saving. In developed countries, families are predominant in supporting children, w...

  9. A Bayesian approach to estimate the prevalence of low height-for-age from the prevalence of low weight-for-age Uma abordagem Bayesiana para obter estimativas de prevalência de déficit de crescimento com base na prevalência de baixo peso para idade

    Directory of Open Access Journals (Sweden)

    Michael E. Reichenheim

    2000-06-01

    Full Text Available Victora et al. (1998 proposed the use of low weight-for-age prevalence to estimate the prevalence of height-for-age deficit in Brazilian children. This procedure was justified by the need to simplify methods used in the context of community health programs. From the same perspective, the present article broadens this proposal by using a Bayesian approach (based on Markov Chain Monte Carlo (MCMC methods to deal with the imprecision resulting from Victora et al.'s model. In order to avoid invalid estimated prevalence values which can occur with the original linear model, truncation or a logit transformation of the prevalences are suggested. The Bayesian approach is illustrated using a community study as an example. Imprecision arising from methodological complexities in the community study design, such as multi-stage sampling and clustering, is easily handled within the Bayesian framework by introducing a hierarchical or multilevel model structure. Since growth deficit was also evaluated in the community study, the article may also serve to validate the procedure proposed by Victora et al.Victora et al. (1998 propuseram o uso de estimativas de prevalência de baixo peso para idade para a estimação de déficit de altura para idade em crianças brasileiras, em virtude da necessidade de simplificar métodos usados em programas de saúde comunitária. Este artigo tenta aprofundar o referido estudo ao propor uma abordagem Bayesiana com base no método de Simulação Estocástica via Cadeia de Markov (SEvCM, para lidar com questões de imprecisão ligadas à modelagem de estimação do déficit de estatura. Para evitar valores inválidos de prevalência estimados pelo modelo linear sugerido originalmente, propõem-se duas alternativas: um truncamento dos valores que extrapolem os limites plausíveis de prevalência ou uma transformação logito das prevalências. A abordagem Bayesiana é ilustrada com um exemplo de um estudo comunitário. Imprecis

  10. Creative Aging.

    Science.gov (United States)

    Ager, Charlene Lee; And Others

    1981-01-01

    Explores some divergent attitudes toward aging, negative as well as positive. Presents a neurophysiological framework to support the belief that aging is an active and creative process. Explores physical, psychological, and sociological aspects, and identifies three factors in the creative aging process. (Author/JAC)

  11. Skin Aging

    Science.gov (United States)

    Your skin changes as you age. You might notice wrinkles, age spots and dryness. Your skin also becomes thinner and loses fat, making it ... heal, too. Sunlight is a major cause of skin aging. You can protect yourself by staying out ...

  12. Ageing Polulations

    DEFF Research Database (Denmark)

    Christiansen, Terkel; Lauridsen, Jørgen Trankjær; Bech, Mickael

    2013-01-01

    An ageing society is characterised by an increasing median age of the population. The purpose of this chapter is to document the existing knowledge about the association between population ageing and health care expenditure, and to supplement this overview by a summary of our original research. S...

  13. Three ages of Venus

    Science.gov (United States)

    Wood, Charles A.; Coombs, Cassandra R.

    1989-01-01

    A central question for any planet is the age of its surface. Based on comparative planetological arguments, Venus should be as young and active as the Earth (Wood and Francis). The detection of probable impact craters in the Venera radar images provides a tool for estimating the age of the surface of Venus. Assuming somewhat different crater production rates, Bazilevskiy et al. derived an age of 1 + or - 0.5 billion years, and Schaber et al. and Wood and Francis estimated an age of 200 to 400 million years. The known impact craters are not randomly distributed, however, thus some area must be older and others younger than this average age. Ages were derived for major geologic units on Venus using the Soviet catalog of impact craters (Bazilevskiy et al.), and the most accessible geologic unit map (Bazilevskiy). The crater counts are presented for (diameters greater than 20 km), areas, and crater densities for the 7 terrain units and coronae. The procedure for examining the distribution of craters is superior to the purely statistical approaches of Bazilevskiy et al. and Plaut and Arvidson because the bins are larger (average size 16 x 10(6) sq km) and geologically significant. Crater densities define three distinct groups: relatively heavily cratered (Lakshmi, mountain belts), moderately cratered (smooth and rolling plains, ridge belts, and tesserae), and essentially uncratered (coronae and domed uplands). Following Schaber et al., Grieve's terrestrial cratering rate of 5.4 + or - 2.7 craters greater than 20 km/10(9) yrs/10(6) sq km was used to calculate ages for the geologic units on Venus. To improve statistics, the data was aggregated into the three crater density groups, deriving the ages. For convenience, the three similar age groups are given informal time stratigraphic unit names, from youngest to oldest: Ulfrunian, Sednaian, Lakshmian.

  14. Successful ageing

    DEFF Research Database (Denmark)

    Kusumastuti, Sasmita; Derks, Marloes G M; Tellier, Siri;

    2016-01-01

    curvilinear pattern with the lowest point at middle age but increases thereafter up to very old age. OBJECTIVE: To shed further light on this paradox, we reviewed the existing literature on how scholars define successful ageing and how they weigh the contribution of health and functioning to define success....... METHODS: We performed a novel, hypothesis-free and quantitative analysis of citation networks exploring the literature on successful ageing that exists in the Web of Science Core Collection Database using the CitNetExplorer software. Outcomes were visualized using timeline-based citation patterns. The......BACKGROUND: Ageing is accompanied by an increased risk of disease and a loss of functioning on several bodily and mental domains and some argue that maintaining health and functioning is essential for a successful old age. Paradoxically, studies have shown that overall wellbeing follows a...

  15. Skin aging:

    OpenAIRE

    Puizina-Ivić, Neira

    2008-01-01

    There are two main processes that induce skin aging: intrinsic and extrinsic. A stochastic process that implies random cell damage as a result of mutations during metabolic processes due to the production of free radicals is also implicated. Extrinsic aging is caused by environmental factors such as sun exposure, air pollution, smoking, alcohol abuse, and poor nutrition. Intrinsicaging reflects the genetic background and depends on time. Various expressions of intrinsic aging include smooth, ...

  16. ESTIMATES OF WATER INGESTION FOR WOMEN IN PREGNANT, LACTATING AND NON-PREGNANT AND NON-LACTATING CHILD BEARING AGE GROUPS BASED ON USDA'S 1994-96, 1998 CONTINUING SURVEY OF FOOD INTAKE BY INDIVIDUALS (Journal Article)

    Science.gov (United States)

    Women in the child bearing age of 15 to 44 years and, in particular, pregnant and lactating women in this age cohort are considered a sensitive subpopulation when assessing risk from ingestion of contaminated water because ingested contaminants may pose a risk not only to the mot...

  17. Ageing management

    International Nuclear Information System (INIS)

    Ageing management is generally defined in a broad sense covering not only ageing management of hardware (structures, systems and components), but also management issues such as keeping up with developments in state-of-the-art technology and the latest management practices. The importance assigned to traditional ageing management, in terms of issues related to hardware degradation problems, is clearly very high. The other aspects, for example developments in engineering or management, are considered important as well, but are less emphasized. Plant ageing management is composed of the following necessary elements, which are all linked together: understanding and knowledge of ageing-related damage mechanisms, including benchmarking of the consequences of damage mechanisms into macroscopic behaviour of materials and structures under applicable conditions; predictive models to extrapolate behaviour of systems, structures or components up to a defined time; qualified methods for detection and surveillance of ageing degradation; qualified mitigation, repair and replacements measures; reliable plant documentation, including optimisation of the ageing management programme based on current understanding and knowledge and periodic self-assessment; availability of a technical service and knowledge base. The subject of plant ageing management has gained increasing attention over the past years, notably as more nuclear power plants across the world are being considered for lifetime extension. In this context, the NEA has conducted numerous technical studies to assess the impact of ageing mechanisms on safe and reliable plant operation. International research activities have also been initiated or are under way to provide the technical basis for decision making. This article provides an overview of some of the activities and accomplishments of the NEA Committee on the Safety of Nuclear Installations (CSNI) Working Group on the Integrity and Ageing of Components and Structures

  18. EASE-Grid Sea Ice Age

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides weekly estimates of sea ice age for the Arctic Ocean from remotely sensed sea ice motion and sea ice extent. The ice age data are derived...

  19. Population Ageing and Technological Change

    OpenAIRE

    Wright, Robert E.; Jouko Kinnunen; Katerina Lisenkova; Marcel Merette

    2014-01-01

    To model the economics impacts of population ageing in high-income countrie by estimating the scale of required technological change. Presentation of a over-lapping generations computable general equilibrium model. Population ageing is associated with low growth and large welfare losses. The scale of technological change needed to compensate for this is very large in historical terms.

  20. Population Aging and Inventive Activity

    OpenAIRE

    Irmen, Andreas; Litina, Anastasia

    2016-01-01

    This research empirically establishes and theoretically motivates the hypothesis that population aging has a hump-shaped effect on inventive activity. We estimate this hump-shaped relationship in a panel of 33 OECD countries over the period 1960-2012. The increasing part of the hump captures the awareness that population aging requires inventive activity to guarantee current and future standards of living. The decreasing part reflects the tendency of aging societies to lose dynamism and the w...

  1. Attitude Estimation or Quaternion Estimation?

    Science.gov (United States)

    Markley, F. Landis

    2003-01-01

    The attitude of spacecraft is represented by a 3x3 orthogonal matrix with unity determinant, which belongs to the three-dimensional special orthogonal group SO(3). The fact that all three-parameter representations of SO(3) are singular or discontinuous for certain attitudes has led to the use of higher-dimensional nonsingular parameterizations, especially the four-component quaternion. In attitude estimation, we are faced with the alternatives of using an attitude representation that is either singular or redundant. Estimation procedures fall into three broad classes. The first estimates a three-dimensional representation of attitude deviations from a reference attitude parameterized by a higher-dimensional nonsingular parameterization. The deviations from the reference are assumed to be small enough to avoid any singularity or discontinuity of the three-dimensional parameterization. The second class, which estimates a higher-dimensional representation subject to enough constraints to leave only three degrees of freedom, is difficult to formulate and apply consistently. The third class estimates a representation of SO(3) with more than three dimensions, treating the parameters as independent. We refer to the most common member of this class as quaternion estimation, to contrast it with attitude estimation. We analyze the first and third of these approaches in the context of an extended Kalman filter with simplified kinematics and measurement models.

  2. Healthy Ageing

    OpenAIRE

    Schans, Cees van der

    2015-01-01

    Presentatie gehouden bij de bijeenkomst voor het Regionaal Genootschap Fysiotherapie Het Noorden op 10 februari te Marum, over het belang van fysieke activiteit voor healthy ageing en de rol van de fysiotherapeut hierin

  3. Estimación forense de la edad en torno a 18 años: Estudio en una población de inmigrantes indocumentados de origen marroquí Legal estimation of age around 18 years: A study of immigrants of Moroccan origin without identification papers

    Directory of Open Access Journals (Sweden)

    P.M. Garamendi

    2003-01-01

    Full Text Available Presentamos una revisión sobre una población judicial de 114 varones marroquíes inmigrantes de los que se solicitó su estimación de edad. La edad cronológica real de los sujetos fue confirmada por mediación de la Embajada de Marruecos en España. El rango confirmado de edad se encontró entre 13 y 25 años con una edad media de 18,1 años y una desviación típica de 2.03. Se practicaron las siguientes pruebas para la estimación forense de la edad: examen físico general, radiografía del carpo (método de Greulich y Pyle y ortopantomografía dental para determinación de maduración de los terceros molares inferiores (método de Dermijian. Nuestros resultados indican que como factores de predicción de una edad cronológica mayor o menor de 18 años la radiografía del carpo (edad ósea fue el método más útil, seguido del método de Dermijian (edad dental. La combinación de variables de edad ósea y edad dental supuso una mejoría significativa en la predicción de la edad cronológica de los sujetos de esta población y permitió minimizar el número de errores éticamente inaceptables de la prueba.We present a review of a population of 114 immigrant Moroccan males for which an age estimate was requested. The subjects' real chronological age was confirmed by the Moroccan Embassy in Spain. The confirmed age range was between 13 and 25, with an average age of 18.1 years and a typical deviation of 2.03. The following tests were performed to arrive at the forensic estimation of age: general physical examination, carpus X-ray (Greulich and Pyle method and dental orthopantomography to determine the degree of maturity of the third inferior molars (Dermijian's method. Carpus X-ray (skeletal age was the most useful method, followed by Dermijian's method (dental age, as prediction factors of a chronological age of over or under 18. The combination of skeletal and dental age variables represented a significant improvement in the prediction of

  4. Martian ages

    International Nuclear Information System (INIS)

    The subjects of this paper are a discussion of the methodology of relative age determination by impact crater statistics, a comparison of currently proposed Martian impact chronologies for the determination of absolute ages from crater frequencies, a report on our work of dating Martian volcanoes and erosional features by impact crater statistics, and an attempt to understand the main features of Martian history through a synthesis of our crater frequency data and those published by other authors. Two cratering chronology models are presented and used for inference of absolute ages from crater frequency data: model 1, with nearly equal Martian and lunar cratering rates around (ca.) 4- to 10-km crater sizes, and model II. equivalent to model I for ages >3.5 x 109 years but with a factor of 2 higher Martian cratering rate at ages 9 years. Those model cratering chronologies are applied to the data. The interpretation of all crater frequency data available and tractable by our methodology leads to a global Martian geological history that is characterized essentially by two epochs of activity. The division between the two epochs is measured at a cumulative crater frequency value for 1-km craters (crater retention age) of N(1) = 8 x 10-4 (km-2) corresponding to an absolute age of ca. 3 x 109 years (applying model I cratering chronology) and of ca. 1.5 x 109 years (applying model II cratering chronology). In the ancient epoch all major events like emplacement of the plains lavas, the piling up of most volcanic constructs, and large-scale erosion of channels and mensae (highland/northern lowland boundary) have taken place. During the younger epoch, only the big Tharsis shield volcanoes were active, and some minor erosion took place. This means that Mars is not a youthful planet but an ancient one with respect to most of its surface features

  5. Premature aging

    International Nuclear Information System (INIS)

    The hypothesis that radiation may accelerate aging phenomenon has been studied extensively, using the population of A-bomb survivors. In this paper, non-specific radiation-induced premature aging is discussed with a review of the literature. Cardiac lipofuscin, papillary fibrosis, aortic extensibility, hexamine/collagen ratio in the skin and aorta, testicular changes, giant hepatic cell nucleus, and neurofibril changes have so far been studied pathologically in the context of A-bomb radiation. Only testicular sclerosis has been found to correlate with distance from the hypocenter. Suggestive correlation was found to exist between the hexamine/collagen ratio in the skin and aorta and A-bomb radiation. Grip strength and hearing ability were decreased in the group of 100 rad and the group of 50-99 rad, respectively. The other physiological data did not definitely correlate with A-bomb radiation. Laboratory data, including erythrocyte sedimentation rate, α and β globulin levels, phytohemagglutinin reaction, T cell counts, erythrocyte glycophorin-A, the incidence of cerebral stroke, ischemic heart disease, and cataract were age-dependent and correlated with A-bomb radiation. These findings indicated that the occurrence of arteriosclerosis-related diseases, changes in immunological competence, and some pathological and physiological findings altered with advancing age, suggesting the correlation with A-bomb radiation. In general, it cannot be concluded that there is a positive correlation between A-bomb radiation and the premature aging. (N.K.) 51 refs

  6. Estimating Utility

    DEFF Research Database (Denmark)

    Arndt, Channing; Simler, Kenneth R.

    2010-01-01

    information-theoretic approach to estimating cost-of-basic-needs (CBN) poverty lines that are utility consistent. Applications to date illustrate that utility-consistent poverty measurements derived from the proposed approach and those derived from current CBN best practices often differ substantially, with...

  7. Successful ageing

    DEFF Research Database (Denmark)

    Bülow, Morten Hillgaard; Söderqvist, Thomas

    2014-01-01

    prevention strategies; and the importance of individual, societal and scientific conceptualisations and understandings of ageing. By presenting an account of the recent historical uses, interpretations and critiques of the concept, the article unfolds the practical and normative complexities of ‘ successful......Since the late 1980s, the concept of ‘ successful ageing’ has set the frame for discourse about contemporary ageing research. Through an analysis of the reception to John W. Rowe and Robert L. Kahn's launch of the concept of ‘ successful ageing’ in 1987, this article maps out the important themes...

  8. Aging Differently

    DEFF Research Database (Denmark)

    Zajitschek, Felix; Jin, Tuo; Colchero, Fernando;

    2014-01-01

    Diet effects on age-dependent mortality patterns are well documented in a large number of animal species, but studies that look at the effects of nutrient availability on late-life mortality plateaus are lacking. Here, we focus on the effect of dietary protein content (low, intermediate, and high...... statistical approach based on Bayesian inference of age-specific mortality rates and found a deceleration of late-life mortality rates on all diets in males but only on the intermediate (standard) diet in females. The difference in mortality rate deceleration between males and females on extreme diets...

  9. Age management

    OpenAIRE

    Kratochvilová, Markéta

    2014-01-01

    The Bachelor‘s thesis focuses on Age Management and its areas of influence. This term is most often discussed in connection with a problem which is currently common for all European Union countries – the ageing of society. In the near future, the structure of society is very likely to be altered drastically as a consequence of this phenomenon and due to the severity of the effects, it is necessary to begin addressing this problem. The first part of the thesis concerns itself with processing d...

  10. Age Spots

    Science.gov (United States)

    ... for treating age spots include: Improved appearance. Enhanced self-esteem. Promotion of better skin health. What you need ... 480px View Render 320px View Connect with ASDS: Facebook LinkedIn YouTube Twitter Quick Links About ASDS Advocacy ...

  11. Aging and dark adaptation.

    Science.gov (United States)

    Jackson, G R; Owsley, C; McGwin, G

    1999-11-01

    Older adults have serious difficulty seeing under low illumination and at night, even in the absence of ocular disease. Optical changes in the aged eye, such as pupillary miosis and increased lens density, cannot account for the severity of this problem, and little is known about its neural basis. Dark adaptation functions were measured on 94 adults ranging in age from the 20s to the 80s to assess the rate of rod-mediated sensitivity recovery after exposure to a 98% bleach. Fundus photography and a grading scale were used to characterize macular health in subjects over age 49 in order to control for macular disease. Thresholds for each subject were corrected for lens density based on individual estimates, and pupil diameter was controlled. Results indicated that during human aging there is a dramatic slowing in rod-mediated dark adaptation that can be attributed to delayed rhodopsin regeneration. During the second component of the rod-mediated phase of dark adaptation, the rate of sensitivity recovery decreased 0.02 log unit/min per decade, and the time constant of rhodopsin regeneration increased 8.4 s/decade. The amount of time to reach within 0.3 log units of baseline scotopic sensitivity increased 2.76 min/decade. These aging-related changes in rod-mediated dark adaptation may contribute to night vision problems commonly experienced by the elderly. PMID:10748929

  12. Healthy ageing

    DEFF Research Database (Denmark)

    Harrison, Adrian Paul; Brüggemann, Dagmar Adeline; Bartels, Else Marie;

    2009-01-01

    The study employed mechanical stretching in vitro of sections of abdominal aorta of elderly mice to investigate any benefits of oral treatment with alpha-ketoglutarate (AKG) on arterial elasticity. Eighteen female mice (50-weeks-old) were assigned to a control (2% w/v) Na2-AKG or (2% w/v) a Ca-AK...... investigation as a candidate for therapies targeting arterial stiffening with age....

  13. Aging Perspectives

    OpenAIRE

    Cosco, Theodore D; David Brehme; Nora Grigoruta; Lisa-Katrin Kaufmann; Liis Lemsalu; Ruth Meex; Angela Schuurmans; Neslihan Sener

    2014-01-01

    Despite the proliferation of successful ageing (SA) research, the literature is dominated by researcher-driven Anglophone conceptualisations. To date, lay perspectives of SA have not been examined in Europe or Turkey. The current study aims to conduct a mixed-methods examination of conceptualisations of SA in seven underrepresented countries. Using snowball sampling via social media sites, an online survey consisting of established closed-ended and open-ended items – translated into seven lan...

  14. 20 CFR 404.811 - The statement of earnings and benefit estimates you requested.

    Science.gov (United States)

    2010-04-01

    ...) Estimates of the monthly retirement (old-age), disability, dependents' and survivors' insurance benefits... on the age at which you plan to retire. The estimate will include the retirement (old-age) insurance... retirement age (currently age 65 to 67, depending on your year of birth) or at your current age if you...

  15. Golden Age

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      Sometimes, a moment can announce the end of an age. The gold market is like that. Within two transaction days, the gold slumped by 13%and saw a 25%tumble from the high point in August 2011. According to the classic investment theory, a 20%-above decline means the shift from“a bull”to“a bear”market.   The super bear market of gold has lasted a dozen years. But the bull-to-bear shift was completed within only 20 minutes. Wall Street’s analysts and ordinary Chinese people had different understandings to the golden age.   Expecting a bear market, Wall Street continuously dumped gold, resulting in a diving of gold price. Seeing the benefits, leisure Chinese madams made a gold rush, causing a slight bounce of gold price. On April 23, renowned investment bank Goldman Sachs suspended the short sale. So,“Chinese aunts”beating back Wall Street’s analysts became the hottest topic online for the time being.   What are the decisive factors for the crash of gold price? Will the gold market complete a real bull-to-bear shift? Will the golden age of gold be farther or nearer?

  16. Sports-Related Eye Injuries by Age

    Science.gov (United States)

    Sports-Related Eye Injuries by Age Activity Estimated Injuries* Ages 0–14 Ages 15+ Basketball 5,237 ... Exercise, Weightlifting) 1,697 401 1,297 Racquet Sports 1,241 233 1,008 Ball Sports, Unspecified ...

  17. Fault Estimation

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2002-01-01

    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...... problems can be solved by standard optimization tech-niques. The proposed methods include: (1) fault diagnosis (fault estimation, (FE)) for systems with model uncertainties; (2) FE for systems with parametric faults, and (3) FE for a class of nonlinear systems....

  18. Cost function estimation

    DEFF Research Database (Denmark)

    Andersen, C K; Andersen, K; Kragh-Sørensen, P

    2000-01-01

    Statistical analysis of cost data is often difficult because of highly skewed data resulting from a few patients who incur high costs relative to the majority of patients. When the objective is to predict the cost for an individual patient, the literature suggests that one should choose a...... regression model based on the quality of its predictions. In exploring the econometric issues, the objective of this study was to estimate a cost function in order to estimate the annual health care cost of dementia. Using different models, health care costs were regressed on the degree of dementia, sex, age......, marital status and presence of any co-morbidity other than dementia. Models with a log-transformed dependent variable, where predicted health care costs were re-transformed to the unlogged original scale by multiplying the exponential of the expected response on the log-scale with the average of the...

  19. Aging Perspectives

    Directory of Open Access Journals (Sweden)

    Theodore D Cosco

    2014-05-01

    Full Text Available Despite the proliferation of successful ageing (SA research, the literature is dominated by researcher-driven Anglophone conceptualisations. To date, lay perspectives of SA have not been examined in Europe or Turkey. The current study aims to conduct a mixed-methods examination of conceptualisations of SA in seven underrepresented countries. Using snowball sampling via social media sites, an online survey consisting of established closed-ended and open-ended items – translated into seven languages – was administered. Grounded theory methods and descriptive statistics were used to analyse qualitative and quantitative data, respectively.

  20. Ice ages

    International Nuclear Information System (INIS)

    The Earth's climate undergoes great changes in cycles of 104 to 105 years. Deep sea sediments contain proof of these changes. The critical parameter is the O18/O16 isotope ratio. The astronomical theory is discussed of ice ages based on the changes in the shape of the Earth's orbit around the sun. Forecasts for the future are given - in the coming years the climate is expected to get warmer owing to increased CO2 levels in the atmosphere, and then a long cooler period is expected to follow. (M.D.)

  1. 11 CFR 110.18 - Voting age population.

    Science.gov (United States)

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Voting age population. 110.18 Section 110.18... PROHIBITIONS § 110.18 Voting age population. There is annually published by the Department of Commerce in the Federal Register an estimate of the voting age population based on an estimate of the voting...

  2. Skin Care and Aging

    Science.gov (United States)

    ... Home » Skin Care and Aging Heath and Aging Skin Care and Aging Dry Skin and Itching Bruises Wrinkles Age Spots ... doctor. For More Information About Skin Care and Aging American Academy of Dermatology 1-866-503-7546 ( ...

  3. The age of the elements

    International Nuclear Information System (INIS)

    The paper is devoted to nuclear cosmochronology. The age of the Universe is estimated with the aid of radioactive nuclear-nuclear chronometers (NC). For calculations it is required that the proportion in which the appropriate pair of NC is at present ('relative abundance') and the proportion for the moment of their formation ('relative production') should be known. A short description is given of production of elements in the process of star evolution. The 'relative production' is calculated theoretically. The relative abundance is determined from experiments, mainly from meteorites. Recentl Lunar rocks have been also coming into use. The following elements are chosen as pairs of chronometers: Th-232/U-238; U-235/U-238; Pu-244/Th-232; J-129/J-127. Using this method the authors have determined the age of elements from 7 to 15 billion years, the best estimate being approximately 10 billion years. This age is quite in an agreement with calculations made by other methods

  4. Population aging and legal retirement age

    OpenAIRE

    Lacomba, Juan Antonio; Lagos, Francisco Miguel

    2005-01-01

    This paper analyzes the effects of population aging on the preferred legal retirement age. What is revealed is the crucial role that the indirect ???macro??? effects resulting from a change in the legal retirement age play in the optimal decision. Two Social Security systems are studied. Under a defined contribution scheme aging lowers the preferred legal retirement age. However, under a defined pension scheme the retirement age is delayed. This result shows the relevance of correctly c...

  5. Aging and Aged in Organized Crime.

    Science.gov (United States)

    Amir, Menachem

    1989-01-01

    Examines problems of the aged in organized crime, basing discussion on organized crime bosses over age 60 operating in Italy, the United States, and Israel. Looks at problems stemming from normative system in organized crime, role of the aged, intergenerational problems, fears of the aged, excuses and justifications, standards of life, and…

  6. Introduction to variance estimation

    CERN Document Server

    Wolter, Kirk M

    2007-01-01

    We live in the information age. Statistical surveys are used every day to determine or evaluate public policy and to make important business decisions. Correct methods for computing the precision of the survey data and for making inferences to the target population are absolutely essential to sound decision making. Now in its second edition, Introduction to Variance Estimation has for more than twenty years provided the definitive account of the theory and methods for correct precision calculations and inference, including examples of modern, complex surveys in which the methods have been used successfully. The book provides instruction on the methods that are vital to data-driven decision making in business, government, and academe. It will appeal to survey statisticians and other scientists engaged in the planning and conduct of survey research, and to those analyzing survey data and charged with extracting compelling information from such data. It will appeal to graduate students and university faculty who...

  7. Malaria transmission rates estimated from serological data.

    OpenAIRE

    M.N. Burattini; Massad, E.; Coutinho, F. A.

    1993-01-01

    A mathematical model was used to estimate malaria transmission rates based on serological data. The model is minimally stochastic and assumes an age-dependent force of infection for malaria. The transmission rates estimated were applied to a simple compartmental model in order to mimic the malaria transmission. The model has shown a good retrieving capacity for serological and parasite prevalence data.

  8. Lifetime estimation methods in power transformer insulation

    OpenAIRE

    Mohammad Ali Taghikhani

    2012-01-01

    Mineral oil in the power transformer has an important role in the cooling, insulation aging and chemical reactions such as oxidation. Oil temperature increases will cause quality loss. The oil should be regularly control in necessary time. Studies have been done on power transformers oils that are used in different age in Iranian power grid to identify the true relationship between age and other characteristics of power transformer oil. In this paper the first method to estimate the life of p...

  9. Trends of Age at Menarche and Association with Body Mass Index in Chinese School-Aged Girls, 1985-2010.

    OpenAIRE

    Song, Yi; Ma, Jun; Wang, Hai-Jun; Wang, Zhiqiang; Hu, Peijin; Zhang, Bing; Agardh, Anette

    2014-01-01

    To estimate the shifts in age at menarche from 1985 to 2010, compare the differences of average age at menarche between urban and rural groups, and determine the association of menarche with body mass index (BMI).

  10. Radiation dose estimates for radiopharmaceuticals

    International Nuclear Information System (INIS)

    Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms

  11. Oral Health and Aging

    Science.gov (United States)

    ... please turn JavaScript on. Feature: Oral Health and Aging Oral Health and Aging Summer 2016 Table of Contents Jerrold H. Epstein, ... they may need. Read More "Oral Health and Aging" Articles Oral Health and Aging / 4 Myths About ...

  12. Skin Care and Aging

    Science.gov (United States)

    ... page please turn Javascript on. Skin Care and Aging How Aging Affects Skin Your skin changes with age. It ... if they bother you. See additional resources on aging skin, including information on treatment options, specific conditions, ...

  13. The Biology of Aging.

    Science.gov (United States)

    Sprott, Richard L.; And Others

    1992-01-01

    Thirteen articles in this special issue discuss aging theories, biomarkers of aging, aging research, disease, cancer biology, Alzheimer's disease, stress, oxidation of proteins, gene therapy, service delivery, biogerontology, and ethics and aging research. (SK)

  14. Age and the architecture of oral mucosa

    OpenAIRE

    Abu Eid, Rasha; Sawair, Faleh; Landini, Gabriel; Saku, Takashi

    2011-01-01

    Age changes affect the oral mucosa (the protective lining of the oral cavity), but few of these have been studied objectively. The aim of this study was to quantitatively analyse a number of morphometric parameters of the ageing oral mucosa. The fractal dimension of the epithelial connective tissue interface (ECTI) was estimated in 42 samples of normal buccal mucosa to correlate any changes in their irregularity to the age of the individuals. Morphometric parameters extracted from theoretical...

  15. Prenatal and early life influences on epigenetic age in children

    DEFF Research Database (Denmark)

    Simpkin, Andrew J; Hemani, Gibran; Suderman, Matthew;

    2016-01-01

    DNA methylation based biomarkers of aging are highly correlated with actual age. Departures of methylation-estimated age from actual age can be used to define epigenetic measures of child development or age acceleration in adults. Very little is known about genetic or environmental determinants...... of these epigenetic measures of aging. We obtained DNA methylation profiles using Infinium HumanMethylation450 BeadChips across five time points in 1018 mother-child pairs from the Avon Longitudinal Study of Parents and Children. Using the Horvath age estimation method, we calculated epigenetic age for these samples....... Age acceleration (AA) was defined as the residuals from regressing epigenetic age on actual age. AA was tested for associations with cross-sectional clinical variables in children. We identified associations between AA and sex, birth weight, birth by caesarean section and several maternal...

  16. Correlation between self-reported gestational age and ultrasound measurements

    DEFF Research Database (Denmark)

    Olesen, Annette Wind; Westergaard, Jes Grabow; Thomsen, Sten Grove; Olsen, Jørn

    2004-01-01

    Hospital Discharge Register. METHODS: The ultrasound-estimated gestational length was based on the size of the biparietal diameter. The ultrasound-estimated gestational length was related to corrected and uncorrected last menstrual period estimates in the Danish National Cohort Study, and to the...... gestational length recorded in the Danish National Discharge Register. Non-parametric statistics were used in the analysis. RESULTS: The gestational ages estimated by ultrasound were 2-3 days shorter than gestational ages estimated by the other methods. The gestational ages recorded by the Discharge Register...

  17. Estimations of actual availability

    International Nuclear Information System (INIS)

    Adaptation of working environment (social, organizational, physical and physical) should assure higher level of workers availability and consequently higher level of workers performance. A special theoretical model for description of connections between environmental factors, human availability and performance was developed and validated. The central part of the model is evaluations of human actual availability in the real working situation or fitness for duties self-estimation. The model was tested in different working environments. On the numerous of 2000 workers standardized values and critical limits for Availability questionnaire were defined. Standardized method was used in identification of the most important impact of environmental factors. Identified problems were eliminated by investments in the organization in modification of selection and training procedures in humanization of working environment. For workers with behavioural and health problems individual consultancy was offered. Described method is a tool for identification of impacts. In combination with behavioural analyses and mathematical analyses of connections offers possibilities to keep adequate level of human availability and fitness for duty in each real working situation. Model should be a tool for achieving adequate level of nuclear safety by keeping the adequate level of workers availability and fitness for duty. For each individual worker possibility for estimation of level of actual fitness for duty is possible. Effects of prolonged work and additional tasks should be evaluated. Evaluations of health status effects and ageing are possible on the individual level. (author)

  18. Estimations of actual availability

    International Nuclear Information System (INIS)

    Adaptation of working environment (social, organizational, physical and physical) should assure higher level of workers' availability and consequently higher level of workers' performance. A special theoretical model for description of connections between environmental factors, human availability and performance was developed and validated. The central part of the model is evaluations of human actual availability in the real working situation or fitness for duties self-estimation. The model was tested in different working environments. On the numerous (2000) workers, standardized values and critical limits for an availability questionnaire were defined. Standardized method was used in identification of the most important impact of environmental factors. Identified problems were eliminated by investments in the organization in modification of selection and training procedures in humanization of working .environment. For workers with behavioural and health problems individual consultancy was offered. The described method is a tool for identification of impacts. In combination with behavioural analyses and mathematical analyses of connections, it offers possibilities to keep adequate level of human availability and fitness for duty in each real working situation. The model should be a tool for achieving adequate level of nuclear safety by keeping the adequate level of workers' availability and fitness for duty. For each individual worker possibility for estimation of level of actual fitness for duty is possible. Effects of prolonged work and additional tasks should be evaluated. Evaluations of health status effects and ageing are possible on the individual level. (author)

  19. Effects of radiation on aging in atomic bomb survivors

    International Nuclear Information System (INIS)

    Promotion of aging was studied on women over the age of 40 years exposed within 1.4 km from the center of the explosion in Nagasaki in whom exposure doses were proved to be over 100 rad (a exposed group). Women exposed over 2.5 km whose ages were the same as those of the exposed group were selected as controls. The age of the exposed group was estimated from stepwise regression equation based on the measurement of hair, grip strength, systolic blood pressure, an amount of potassium in the whole body, and erythrocyte count, which changed remarkably with time. The estimated age of the exposed group was over one year older than that of controls. Especially, mean estimated age of the exposed group in their forties (the age at the time of exposure, teens) was 1.4 year older than the actual age, which suggests that radiation promote aging. (Tsunoda, M.)

  20. Facial aging: A clinical classification

    Directory of Open Access Journals (Sweden)

    Shiffman Melvin

    2007-01-01

    Full Text Available The purpose of this classification of facial aging is to have a simple clinical method to determine the severity of the aging process in the face. This allows a quick estimate as to the types of procedures that the patient would need to have the best results. Procedures that are presently used for facial rejuvenation include laser, chemical peels, suture lifts, fillers, modified facelift and full facelift. The physician is already using his best judgment to determine which procedure would be best for any particular patient. This classification may help to refine these decisions.

  1. The evaluation of two radiographic methods for age determination of children in an Indian population.

    Science.gov (United States)

    Rai, B

    2008-12-01

    The aim of the present study was to evaluate the applicability of the methods proposed by Nolla and Nicodemo for estimation of dental age and its correction with chronological age. Orthopantograms of 413 patients, aged 6-16 year (70-195 months) were selected to estimate the correlation between dental and chronological age. With both the Nolla and Nicodemo methods, the estimated age was lower than compared to chronological age except for the Nolla method in girls. There were significant correlations between chronological and estimated dental age (by Nolla and Nicodemo methods) in both genders. PMID:22717786

  2. SURFACE VOLUME ESTIMATES FOR INFILTRATION PARAMETER ESTIMATION

    Science.gov (United States)

    Volume balance calculations used in surface irrigation engineering analysis require estimates of surface storage. These calculations are often performed by estimating upstream depth with a normal depth formula. That assumption can result in significant volume estimation errors when upstream flow d...

  3. Avoiding Aging? Social Psychology's Treatment of Age

    Science.gov (United States)

    Barrett, Anne E.; Redmond, Rebecca; von Rohr, Carmen

    2012-01-01

    Population aging, in conjunction with social and cultural transformations of the life course, has profound implications for social systems--from large-scale structures to micro-level processes. However, much of sociology remains fairly quiet on issues of age and aging, including the subfield of social psychology that could illuminate the impact of…

  4. Healthy Aging -- Sexual Health

    Science.gov (United States)

    ... address Submit Home > Healthy Aging > Sexual health Healthy Aging This information in Spanish ( en español ) Sexual health ... to discuss with your doctor. Sexual Health and Aging: Keep the Passion Alive (Copyright © Mayo Foundation) - This ...

  5. Administration on Aging

    Science.gov (United States)

    ... Federal Initiatives Career Opportunities Contact Us Administration on Aging (AoA) The Administration on Aging (AOA) is the ... themselves. Back to top Older Americans Act and Aging Network To meet the diverse needs of the ...

  6. Aging changes in sleep

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/004018.htm Aging changes in sleep To use the sharing features ... cycle is repeated several times during the night. AGING CHANGES With aging, sleep patterns tend to change. ...

  7. Remote remanence estimation (RRE)

    Science.gov (United States)

    Pratt, David A.; McKenzie, K. Blair; White, Tony S.

    2014-09-01

    The remote determination of magnetic remanence in rocks is a method that has largely been ignored because of the ambiguity associated with the estimation of both the Koenigsberger ratio and remanent magnetisation direction. Our research shows that the resultant magnetisation direction can be derived directly through inversion of magnetic data for an isolated magnetic anomaly from a compact magnetic source. The resultant magnetisation direction is a property of the target magnetic rocks and a robust inversion parameter. The departure angle of the resultant magnetisation vector from that of the inducing magnetic field is an important indicator of the existence of remanent magnetisation and the inversion process can detect departures that are not easily detected by visual inspection. This departure angle is called the apparent resultant rotation angle or ARRA. The induced field vector, remanent magnetisation vector and resultant magnetisation vector lie on the plane of a great circle. We find the intersection of the transformed polar wander vector trace with the great circle plane to obtain one or more possible solutions for the remanent magnetisation vector. Geological deduction will normally allow us to reduce the ambiguity for multiple solutions to obtain the most likely remanent magnetisation direction. Once the remanent magnetisation direction is established, it is then possible to determine the Koenigsberger ratio and magnetic susceptibility for the target. We illustrate the methodology using survey data over the Black Hill Norite which also has extensive palaeomagnetic data available for comparison with the inversion results. We then apply the remote remanence estimation (RRE) method to a systematic study of a large number of intrusive pipes in the Thomson Orogen, New South Wales. The corrected magnetic susceptibility and remanence properties, spatial distribution and underlying uncertainties are evaluated for their potential use by diamond explorers. The

  8. Multifractal age? Multifractal analysis of cardiac interbeat intervals in assessing of healthy aging

    CERN Document Server

    Makowiec, Danuta; Wdowczyk-Szulc, Joanna; Zarczynska-Buchowiecka, Marta; Gruchal, Marcin; Rynkiewicz, Andrzej

    2013-01-01

    24-hour Holter recordings of 124 healthy people at different age are studied. The nocturnal signals of young people reveal the presence of the multiplicative structure. This structure is significantly weaker in diurnal signals and becomes less evident for elderly people. Multifractal analysis allows us to propose qualitative and quantitative methods to estimate the advancement of the aging process for healthy humans.

  9. Ensemble estimators for multivariate entropy estimation

    CERN Document Server

    Sricharan, Kumar

    2012-01-01

    The problem of estimation of density functionals like entropy and mutual information has received much attention in the statistics and information theory communities. A large class of estimators of functionals of the probability density suffer from the curse of dimensionality, wherein the exponent in the MSE rate of convergence decays increasingly slowly as the dimension $d$ of the samples increases. In particular, the rate is often glacially slow of order $O(T^{-{\\gamma}/{d}})$, where $T$ is the number of samples, and $\\gamma>0$ is a rate parameter. Examples of such estimators include kernel density estimators, $k$-NN density estimators, $k$-NN entropy estimators, intrinsic dimension estimators and other examples. In this paper, we propose a weighted convex combination of an ensemble of such estimators, where optimal weights can be chosen such that the weighted estimator converges at a much faster dimension invariant rate of $O(T^{-1})$. Furthermore, we show that these optimal weights can be determined by so...

  10. Consequences of Secondary Calibrations on Divergence Time Estimates.

    Directory of Open Access Journals (Sweden)

    John J Schenk

    Full Text Available Secondary calibrations (calibrations based on the results of previous molecular dating studies are commonly applied in divergence time analyses in groups that lack fossil data; however, the consequences of applying secondary calibrations in a relaxed-clock approach are not fully understood. I tested whether applying the posterior estimate from a primary study as a prior distribution in a secondary study results in consistent age and uncertainty estimates. I compared age estimates from simulations with 100 randomly replicated secondary trees. On average, the 95% credible intervals of node ages for secondary estimates were significantly younger and narrower than primary estimates. The primary and secondary age estimates were significantly different in 97% of the replicates after Bonferroni corrections. Greater error in magnitude was associated with deeper than shallower nodes, but the opposite was found when standardized by median node age, and a significant positive relationship was determined between the number of tips/age of secondary trees and the total amount of error. When two secondary calibrated nodes were analyzed, estimates remained significantly different, and although the minimum and median estimates were associated with less error, maximum age estimates and credible interval widths had greater error. The shape of the prior also influenced error, in which applying a normal, rather than uniform, prior distribution resulted in greater error. Secondary calibrations, in summary, lead to a false impression of precision and the distribution of age estimates shift away from those that would be inferred by the primary analysis. These results suggest that secondary calibrations should not be applied as the only source of calibration in divergence time analyses that test time-dependent hypotheses until the additional error associated with secondary calibrations is more properly modeled to take into account increased uncertainty in age estimates.

  11. Spectral ageing a new age perspective

    CERN Document Server

    Rawlings, S; Rawlings, Katherine M Blundell & Steve

    2002-01-01

    We present an up-to-date critique of the physical basis for the spectral ageing method. We find that the number of cases where this method may be meaningfully applied to deduce the ages of classical double radio sources is small indeed. This critique is much more than merely a re-expression of anxieties about the calibration of spectral ageing (which have been articulated by others in the past).

  12. New concept of age(ing: Prospective age

    Directory of Open Access Journals (Sweden)

    Devedžić Mirjana

    2012-01-01

    Full Text Available While the last century was the century of world population growth, according to demographers, the XXI century will be century of population aging. Statistics undoubtedly show that number of elderly will continue it’s growth in the future. If old age is seen as period of life with reduced physical and mental capabilities and increased disability, and demographic aging as increase of dependent population, trends are quite disturbing, at least in certain societal segments. In developed countries, this population category is no longer treated as passive or as a "burden of society" and efforts are made for better social inclusion of older people. In contrast to growing interest in this phenomenon, the concepts that define the aging of the population remained stagnant. The aim of this paper is to introduce into domestic literature the term "prospective age" as a dynamic category which is more affected with socio-historical conditions, not only with biological as traditional definition of aging suggested. Papers written by Sanderson and Scherbov offer new methodological options for study of population aging, because it takes into account the biometric rather than chronological approach. Calculation of prospective years is a simple operation that requires pair of the same number of remained life expectancy from life tables for two different periods (the year of concern is index, and the one we are comparing with is standard year, so that phrase "40s is the new 30s" or "70s the new 60s" gets scientific foundation. Average remaining years of life represent a realistic indicator suggesting increased capacity, activity and vitality of individuals, which is due to accepted demographic parameters still considered old. „Prospective threshold“ is defined as the age when life expectancy falls below 15 years (it is subjective choice made by Sanderson and Scherbov, which is also used in this paper and during the elaboration of these ideas three demographic

  13. Estimation of caries experience by multiple imputation and direct standardization

    NARCIS (Netherlands)

    Schuller, A.A.; Buuren, S. van

    2014-01-01

    Valid estimates of caries experience are needed to monitor oral population health. Obtaining such estimates in practice is often complicated by nonresponse and missing data. The goal of this study was to estimate caries experiences in a population of children aged 5 and 11 years, in the presence of

  14. Estimation of Caries Experience by Multiple Imputation and Direct Standardization

    NARCIS (Netherlands)

    Schuller, A. A.; van Buuren, S.

    2014-01-01

    Valid estimates of caries experience are needed to monitor oral population health. Obtaining such estimates in practice is often complicated by nonresponse and missing data. The goal of this study was to estimate caries experiences in a population of children aged 5 and 11 years, in the presence of

  15. Reliable Re-Os age for molybdenite

    Science.gov (United States)

    Suzuki, Katsuhiko; Qi-Lu; Shimizu, Hiroshi; Masuda, Akimasa

    1993-04-01

    Re-Os ages for four molybdenites were determined by our newly developed method with isotope dilution-mass spectrometry. Special caution was given to achieve osmium isotopic equilibration between sample and "spike" during chemical treatment. Re-Os data for molybdenites from Mt. Mulgine (Australia), Mätäsvaara (Finland), Preissac (Canada), and Climax (USA) define ages of 2790 Ma, 2600 Ma, 2680 Ma, and 26.6 Ma, respectively. The reproducibilities of our Re-Os age determination are shown to be within 2% by the replicate analyses for Mt. Mulgine, Mätäsvaara, and Preissac samples. The ages obtained are in good agreement with reference ages estimated for wall rocks of molybdenite deposits concerned. Thus, with careful experimental procedure, it appears that the Re-Os geochronometer can be used to reliably determine the age of molybdenite.

  16. Reliable Re-Os age for molybdenite

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Katsuhiko (Univ. of Tokyo (Japan)); Lu, Q.; Masuda, Akimasa (Univ. of Electro-Communications, Tokyo (Japan)); Shimizu, Hiroshi (Kumamoto Univ. (Japan))

    1993-04-01

    Re-Os ages for four molybdenites were determined by the authors' newly developed method with isotope dilution-mass spectrometry. Special caution was given to achieve osmium isotopic equilibration between sample and spike during chemical treatment. Re-Os data for molybdenites from Mt. Mulgine (Australia), Maetaesvaara (Finland), Preissac (Canada), and Climax (US) define ages of 2790 Ma, 2600 Ma, 2680 Ma, and 26.6 Ma, respectively. The reproducibilities of their Re-Os age determination are shown to be within 2% by the replicate analyses for Mt. Mulgine, Maetaesvaara, and Preissac samples. The ages obtained are in good agreement with reference ages estimated for wall rocks of molybdenite deposits concerned. Thus, with careful experimental procedure, it appears that the Re-Os geochronometer can be used to reliably determine the age of molybdenite. 32 refs., 1 tab.

  17. Estimation of excess numbers of viral diarrheal cases among children aged <5 years in Beijing with adjusted Serfling regression model%应用调整Serfling回归模型估计北京市5岁以下儿童病毒性腹泻相关超额病例数

    Institute of Scientific and Technical Information of China (English)

    贾蕾; 王小莉; 吴双胜; 马建新; 李洪军; 高志勇; 王全意

    2016-01-01

    Objective To estimate the excess numbers of viral diarrheal cases among children aged <5 years in Beijing from 1 January 2011 to 23 May 2015.Methods The excess numbers of diarrheal cases among the children aged <5 years were estimated by using weekly outpatient visit data from two children' s hospital in Beijing and adjusted Serfling regression model.Results The incidence peaks of viral diarrhea were during 8th-10th week and 40th-42nd week in 2011,40th-4th week in 2012,43rd-49th week in 2013 and 45th week in 2014 to 11th week in 2015 respectively.The excess numbers of viral diarrheal cases among children aged <5 years in the two children's hospital were 911(95%CI:261-1 561),1 998(95%CI:1 250-2 746),1 645 (95%CI:891-2 397),2 806(95%CI:1 938-3 674) and 1 822(95% CI:614-3 031) respectively,accounting for 40.38% (95% CI:11.57%-69.19%),44.21%(95%CI:27.66%-60.77%),45.08%(95%CI:24.42%-65.69%),60.87% (95%CI:42.04%-79.70%) and 66.62% (95%CI:22.45%-110.82%) of total outpatient visits due to diarrhea during 2011-2015,respectively.Totally,the excess number of viral diarrheal cases among children aged <5 years in Beijing was estimated to be 18 731(95%CI:10 106-27 354) from 2011 to 23 May 2015.Conclusions Winter is the season of viral diarrhea for children aged <5 years.The adjusted Serfling regression model analysis suggested that close attention should be paid to the etiologic variation of viruses causing acute gastroenteritis,especially the etiologic variation of norovirus.%目的 构建调整Serf ling回归模型,估计北京市2011年至2015年5月23日病毒性腹泻相关<5岁儿童超额腹泻病例数.方法 利用北京市2家儿童专科医院<5岁儿童急性腹泻周就诊病例数,拟合调整Serf ling回归模型,估计其病毒性腹泻相关超额病例数.结果 北京市2011年第8~10周、40~ 42周,2012年第40~46周,2013年第43~49周,2014年第45周直到2015年第11

  18. A Bistochastic Nonparametric Estimator

    OpenAIRE

    Juan Gabriel Rodríguez; Rafael Salas

    2004-01-01

    We explore the relevance of adopting a bistochastic nonparametric estimator. This estimator has two main implications. First, the estimator reduces variability according to the robust criterion of second-order stochastic (and Lorenz) dominance. This is a universally criterion in risk and welfare economics, which expands the applicability of nonparametric estimation in economics, for instance to the measurement of economic discrimination. Second, the bistochastic estimator produces smaller err...

  19. ON INTERVAL ESTIMATING REGRESSION

    Directory of Open Access Journals (Sweden)

    Marcin Michalak

    2014-06-01

    Full Text Available This paper presents a new look on the well-known nonparametric regression estimator – the Nadaraya-Watson kernel estimator. Though it was invented 50 years ago it still being applied in many fields. After these yearsfoundations of uncertainty theory – interval analysis – are joined with this estimator. The paper presents the background of Nadaraya-Watson kernel estimator together with the basis of interval analysis and shows the interval Nadaraya-Watson kernel estimator.

  20. Dynamic stratification for estimating pointwise forest characteristics.

    OpenAIRE

    Mozgeris, Gintautas

    1996-01-01

    This paper deals with the testing of dynamic stratification for estimating stand level forest characteristics (basal area, mean diameter, mean height and mean age) for a 117 ha study area in Finland. The results do not show possibilities to achieve more accurate estimates using only Landsat TM principal components as auxiliary data opposed to static stratification. It was found that in dynamic stratification non-measured observations should be assigned the mean characteristics of the measured...

  1. Assessing age in the desert tortoise Gopherus agassizii: Testing skeletochronology with individuals of known age

    Science.gov (United States)

    Curtin, A.J.; Zug, G.R.; Medica, P.A.; Spotila, J.R.

    2008-01-01

    Eight desert tortoises Gopherus agassizii from a long-term mark-recapture study in the Mojave Desert, Nevada, USA, afforded an opportunity to examine the accuracy of skeletochronological age estimation on tortoises from a seasonal, yet environmentally erratic environment. These 8 tortoises were marked as hatchlings or within the first 2 yr of life, and their carcasses were salvaged from predator kills. Using d blind protocol, 2 skeletochronological protocols (correction-factor and ranking) provided age estimates for a set of 4 bony elements (humerus, scapula, femur, ilium) from these tortoises of known age. The age at death of the tortoises ranged from 15 to 50 yr. The most accurate protocol - ranking using the growth layers within each of the 4 elements - provided estimates from 21 to 47 yr, with the highest accuracy from the ilia. The results indicate that skeletochronological age estimation provides a reasonably accurate method for assessing the age at death of desert tortoises and, if used with a large sample of individuals, will provide a valuable tool for examining age-related mortality parameters in desert tortoise and likely in other gopher tortoises (Gopherus). ?? Inter-Research 2008.

  2. Bomb dating, age validation and quality control of age determinations of monodontids and other marine mammals

    Directory of Open Access Journals (Sweden)

    Steven E Campana

    2014-05-01

    Full Text Available Methods for confirming the accuracy of age determination methods are reasonably well established in fishes, but the millions of routine age determinations which take place every year require their own quality control protocols. In contrast, methods for ensuring accuracy in age determination of monodontids and other marine mammals are still being developed. Here we review the basis and application of bomb radiocarbon to marine mammal age validation, highlighting its value for providing unambiguous estimates of age for belugas and other long-lived animals which form growth bands. Bomb radiocarbon is particularly useful for marine mammals, given that the age of an individual animal can be determined to within ±1-3 years, as long as it was alive during the 1960s. However, ongoing age determinations require careful monitoring to ensure that age interpretations remain consistent across ages and through time. Quality control protocols using reference collections of ageing material, in conjunction with age bias plots and measures of precision, are capable of detecting virtually all of the systematic ageing errors that often occur once age determinations of an animal become routine.

  3. DNA methylation age is associated with mortality in a longitudinal Danish twin study

    DEFF Research Database (Denmark)

    Christiansen, Lene; Lenart, Adam; Tan, Qihua; Vaupel, James W.; Aviv, Abraham; McGue, Matt; Christensen, Kaare

    2016-01-01

    An epigenetic profile defining the DNA methylation age (DNAm age) of an individual has been suggested to be a biomarker of aging, and thus possibly providing a tool for assessment of health and mortality. In this study, we estimated the DNAm age of 378 Danish twins, age 30–82 years, and furthermo...

  4. Nonparametric Filament Estimation

    CERN Document Server

    Genovese, Christopher R; verdinelli, Isabella; Wasserman, Larry

    2010-01-01

    We develop nonparametric methods for estimating filamentary structure from planar point process data and find the minimax lower bound for this problem. We show that, under weak conditions, the filaments have a simple geometric representation as the medial axis of the data distribution's support. Our methods convert an estimator of the support's boundary into an estimator of the filaments. We find the rates of convergence of our estimators and show that when using an optimal boundary estimator, they achieve the minimax rate. Our work can be regarded as providing a solution to the manifold learning problem as well as being a new approach to principal curve estimation.

  5. Sociological effects on vocal aging: Age related F0 effects in two languages

    Science.gov (United States)

    Nagao, Kyoko

    2005-04-01

    Listeners can estimate the age of a speaker fairly accurately from their speech (Ptacek and Sander, 1966). It is generally considered that this perception is based on physiologically determined aspects of the speech. However, the degree to which it is due to conventional sociolinguistic aspects of speech is unknown. The current study examines the degree to which fundamental frequency (F0) changes due to advanced aging across two language groups of speakers. It also examines the degree to which the speakers associate these changes with aging in a voice disguising task. Thirty native speakers each of English and Japanese, taken from three age groups, read a target phrase embedded in a carrier sentence in their native language. Each speaker also read the sentence pretending to be 20-years younger or 20-years older than their own age. Preliminary analysis of eighteen Japanese speakers indicates that the mean and maximum F0 values increase when the speakers pretended to be younger than when they pretended to be older. Some previous studies on age perception, however, suggested that F0 has minor effects on listeners' age estimation. The acoustic results will also be discussed in conjunction with the results of the listeners' age estimation of the speakers.

  6. Aging of gaseous detectors

    International Nuclear Information System (INIS)

    This paper makes an overview of developments in the wire chamber aging field since the wire chamber aging workshop held at the Lawrence Berkeley Laboratory, Berkeley, California on January 16--17, 1986. The author discusses new techniques to analyze the gas impurities and the wire aging products, wire ''nonaging'' in clean systems, wire aging in systems containing various impurities, various examples of problems which can ''prime'' surfaces prior to the occurrence of the aging, and some recent aging experience with the ''SSC micro-straw tubes.'' 35 refs., 10 figs., 2 tabs

  7. The Age of Beta Pic

    OpenAIRE

    Navascues, D. Barrado y; Stauffer, J. R.; Song, I.; Caillault, J-P.

    1999-01-01

    We have reanalyzed data for the proposed moving group associated with beta Pic in order to determine if the group (or part of it) is real, and, if so, to derive an improved age estimate for beta Pic. By using new, more accurate proper motions from PPM and Hipparcos and a few new radial velocities, we conclude that on kinematic grounds, two M dwarfs have space motions that coincide with that of beta Pic to within 1 km/s with small error bars. Based on a CM diagram derived from accurate photome...

  8. The problem of aging human remains and living individuals

    DEFF Research Database (Denmark)

    Cunha, E; Baccino, E; Martrille, L;

    2009-01-01

    , and although they may be thought of as equivalent, every procedure has its limits, mean error, practical situation and age range where it gives the best results; the lack of standardization and consensus concerning which method can be used, as well as the lack of a practical approach in different......Forensic anthropology is affected by the unavoidable limits concerning difficulties in standardization of methods and procedures; age estimation is one of the main tasks of forensic anthropology and odontology, both on the dead and the living: literature has shown several methods of age estimation...... cases is the main limit in a correct age estimation process. This review aims at exposing the experience of the authors working in the FASE (Forensic Anthropology Society of Europe) subsection of IALM (International Academy of Legal Medicine) in the field of age estimation both on the dead and the...

  9. On the biases affecting water ages inferred from isotopic data

    OpenAIRE

    Cornaton, F. J.; Park, Y. -J.; Deleersnijder, E.

    2011-01-01

    Groundwater age has become a fundamental concept in groundwater hydrology, but ages originating from isotopic analyses are still identified with a lack of clarity and using models that occasionally are unrealistic. If the effect of advection and dispersion on water ages has already been extensively identified, very few studies address the reliability of using radiometric ages as derived from isotopic data to estimate aquifer properties such as average velocities. Using simple one-dimensional ...

  10. Age at menarche in schoolgirls with and without excess weight

    OpenAIRE

    Silvia D. Castilho; Luciana B. Nucci

    2015-01-01

    OBJECTIVE: To evaluate the age at menarche of girls, with or without weight excess, attending private and public schools in a city in Southeastern Brazil. METHODS: This was a cross-sectional study comparing the age at menarche of 750 girls from private schools with 921 students from public schools, aged between 7 and 18 years. The menarche was reported by the status quo method and age at menarche was estimated by logarithmic transformation. The girls were grouped according to body mass index ...

  11. Active Ageing Level of Older Persons: Regional Comparison in Thailand

    OpenAIRE

    Md. Nuruzzaman Haque

    2016-01-01

    Active ageing level and its discrepancy in different regions (Bangkok, Central, North, Northeast, and South) of Thailand have been examined for prioritizing the policy agenda to be implemented. Attempt has been made to test preliminary active ageing models for Thai older persons and hence active ageing index (AAI, ranges from 0 to 1) has been estimated. Using nationally representative data and confirmatory factor analysis approach, this study justified active ageing models for female and male...

  12. Population Aging and Future Carbon Emissions in the United States

    OpenAIRE

    Dalton, M.G.; O'Neill, B. C.; Fuernkranz-Prskawetz, A.; Jiang, L.; Pitkin, J

    2005-01-01

    Changes in the age composition of U.S. households over the next several decades could affect energy use and carbon dioxide emissions. this article incorporates population age structure into and energy-economic growth model with multiple dynasties of heterogenous households. The model is used to estimate and compare effects of population aging and technical change on baseline paths of U.S. energy use and emissions. Results show that population aging reduces long-term carbon dioxide emissions, ...

  13. A review of image-based tools for automatic fish ageing from otolith features

    OpenAIRE

    Carbini, Sebastien; Chessel, Anatole; Benzinou, Abdesslam; Fablet, Ronan; Mahe, Kelig; De Pontual, Helene

    2008-01-01

    Most of European fish stocks are assessed using age-based models, and otolith interpretation for age estimations costs several million euros annually. In this context, automated ageing systems would provide a mean to 1) standardize ageing, 2) control ageing consistency within and between ageing laboratories 3) build interpreted image data bases ensuring the information conservation and sharing and 4) improve growth studies while reducing the cost of the acquisition of age data. This paper pre...

  14. CEO age and gender: Subsequent market performance

    Directory of Open Access Journals (Sweden)

    Marcelo Eduardo

    2016-12-01

    Full Text Available The issue of CEO age and gender vs. concurrent performance is extensively examined, but the association with subsequent performance has limited treatment in the financial literature, and with conflicting findings. In the current study, we examine the association between CEO age and gender, and subsequent company market performance using a more recent set of observations and the standard four-factor model to estimate future cumulative abnormal shareholder returns. We find that subsequent abnormal shareholder returns are marginally significantly higher for female CEOs than for their male counterparts, but no material pattern is observed between CEO age and subsequent abnormal shareholder return performance.

  15. Estimação de parâmetros genéticos de medidas de conformação, produção de leite e idade ao primeiro parto em vacas da raça Gir Leiteiro Estimate of genetic parameters of conformation traits, milk production and age at first calving in dairy Gyr breed cows

    Directory of Open Access Journals (Sweden)

    Amauri Arias Wenceslau

    2000-02-01

    Full Text Available RESUMO - Foram utilizados 573 registros zootécnicos de vacas primíparas da raça Gir Leiteiro para estimar os componentes de (covariância das características de conformação, produção de leite em até 305 dias de lactação (PLEI e idade ao primeiro parto (IPP pelo Método da Máxima Verossimilhança Restrita (REML. Esses componentes foram utilizados no cálculo dos coeficientes de herdabilidade e nas correlações genéticas, fenotípicas e residuais. As medidas de conformação, circunferência torácica (CTOR, altura na garupa (AG, comprimento corporal (CC, comprimento de tetas (CT, diâmetro de tetas (DT e altura de úbere (AU foram realizadas em vacas à primeira lactação, com idade média de 4,05 anos. As correlações genéticas e fenotípicas entre PLEI e IPP foram 0,49 e 0,18, respectivamente. As correlações genéticas entre as características foram: PLEI x CTOR = -0,37; PLEI x AG = -0,62; PLEI x CC = -0,52; PLEI x CT = -0,08; PLEI x DT = -0,12; PLEI x AU = -0,69; IPP x CTOR = -0,05; IPP x AG = -0,37; e IPP x CC = 0,25. As estimativas de correlações genéticas entre produção de leite e medidas de tamanho corporal, de modo geral, indicam que a seleção para produção de leite teria, como resposta correlacionada, diminuição do tamanho da vaca.ABSTRACT - Data from 573 primiparous lactating Gyr cows were used to estimate the (co variance components of the conformation traits, milk production up to 305 days of lactation (MP and age at first calving (AFC by REML method. These components were used to calculate heritability coefficients and genetic, phenotypic and residual correlations. The conformation measures, the heart girth (HG, croup height (CH, body length (BL, teats length (TL, teats diameter (TD and udder height (UH were obtained in the cows at first lactation with average age of 4.05 years. The genetic and phenotypic correlations between MP and AFC were 0.49 and 0.18 respectively. The genetic correlation between

  16. Software Cost Estimation Review

    OpenAIRE

    Ongere, Alphonce

    2013-01-01

    Software cost estimation is the process of predicting the effort, the time and the cost re-quired to complete software project successfully. It involves size measurement of the soft-ware project to be produced, estimating and allocating the effort, drawing the project schedules, and finally, estimating overall cost of the project. Accurate estimation of software project cost is an important factor for business and the welfare of software organization in general. If cost and effort estimat...

  17. Total Grid Estimation

    OpenAIRE

    R. Kelley Pace

    1998-01-01

    This article provides a matrix representation of the adjustment grid estimator. From this representation, one can invoke the Gauss-Mrkov theorem to examine the efficiency of ordinary least squares (OLS) and the grid estimator that uses OLS estimates of the adjustments (the "plug-in" grid method). In addition, this matrix representation suggests a generalized least squares version of the grid method, labeled herin as the total grid estimator. Based on the empirical experiments, the total grid ...

  18. Characterising the pollutant ventilation characteristics of street canyons using the tracer age and age spectrum

    Science.gov (United States)

    Lo, K. W.; Ngan, K.

    2015-12-01

    The age of air, which measures the time elapsed between the emission of a chemical constituent and its arrival at a receptor location, has many applications in urban air quality. Typically it has been estimated for special cases, e.g. the local mean age of air for a spatially homogeneous source. An alternative approach uses the response to a point source to determine the distribution of transit times or tracer ages connecting the source and receptor. The distribution (age spectrum) and first moment (mean tracer age) have proven to be useful diagnostics in stratospheric modelling because they can be related to observations and do not require a priori assumptions. The tracer age and age spectrum are applied to the pollutant ventilation of street canyons in this work. Using large-eddy simulations of flow over a single isolated canyon and an uneven, non-uniform canyon array, it is shown that the structure of the tracer age is dominated by the central canyon "vortex"; small variations in the building height have a significant influence on the structure of the tracer age and the pollutant ventilation. The age spectrum is broad, with a long exponential tail whose slope depends on the canyon geometry. The mean tracer age, which roughly characterises the ventilation strength, is much greater than the local mean age of air.

  19. Visual Signs of Ageing

    Directory of Open Access Journals (Sweden)

    Helle Rexbye

    2007-07-01

    Full Text Available Consumer culture has placed the ageing body in a dilemma of representation. Physical appearance has become increasingly important as a symbol of identity, and at the same time society idealizes youth. This study explores visual ageing empirically. By using photographs of older persons (70+ as starting point, it is explored how visual age is assessed and interpreted. It is shown that informants read age in a spread of stages and categories. Main age indicators are biological markers: skin, eyes, and hair colour, but supplemented by vigour, style, and grooming. Furthermore, in-depth interviews indicate that visual age is mainly interpreted into categories and moral regulations rooted in early modernity. Subsequently the question of a postmodern perspective of visual ageing is discussed in this article. The empirical findings in the study question a postmodern fluidity of visual signs – at least when the concern is signs of ageing.

  20. National Institute on Aging

    Science.gov (United States)

    ... Join Our Mailing List Email The Leader in Aging Research NIA, one of the 27 Institutes and ... broad scientific effort to understand the nature of aging and to extend the healthy, active years of ...

  1. Aging changes in immunity

    Science.gov (United States)

    ... cells and antibodies that destroy these harmful substances. Aging Changes and Their Effects on the Immune System ... Prevention To decrease the risks from immune system aging: Get the flu and pneumonia vaccines, and any ...

  2. NIA Aging Cell Repository

    Data.gov (United States)

    Federal Laboratory Consortium — To facilitate aging research on cells in culture, the NIA provides support for the NIA Aging Cell Repository, located at the Coriell Institute for Medical Research...

  3. Corrected Age for Preemies

    Science.gov (United States)

    ... Prenatal Baby Bathing & Skin Care Breastfeeding Crying & Colic Diapers & Clothing Feeding & Nutrition Preemie Sleep Teething & Tooth Care Toddler Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Baby > Preemie > Corrected Age ...

  4. Alaska Radiometric Ages

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Alaska Radiometric Age file is a database of radiometric ages of rocks or minerals sampled from Alaska. The data was collected from professional publications...

  5. Aging changes in immunity

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/004008.htm Aging changes in immunity To use the sharing features ... cells and antibodies that destroy these harmful substances. Aging Changes and Their Effects on the Immune System ...

  6. Memory and Aging

    Science.gov (United States)

    Memory and Aging Losing keys, misplacing a wallet, or forgetting someone’s name are common experiences. But for people nearing or over age 65, such memory lapses can be frightening. They wonder if they ...

  7. ESTIMATING IRRIGATION COSTS

    Science.gov (United States)

    Having accurate estimates of the cost of irrigation is important when making irrigation decisions. Estimates of fixed costs are critical for investment decisions. Operating cost estimates can assist in decisions regarding additional irrigations. This fact sheet examines the costs associated with ...

  8. Estimation of genome length

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The genome length is a fundamental feature of a species. This note outlined the general concept and estimation method of the physical and genetic length. Some formulae for estimating the genetic length were derived in detail. As examples, the genome genetic length of Pinus pinaster Ait. and the genetic length of chromosome Ⅵ of Oryza sativa L. were estimated from partial linkage data.

  9. Components of aging

    OpenAIRE

    Wiegand, Iris

    2013-01-01

    Age-related cognitive decline has been linked to a reduction in attentional resources that are assumed to result from alterations in the aging brain. A core ability that is subject to age-related decline is visual attention, which enables individuals to select the most important information for conscious processing and action. However, visual attention is considered a conglomerate of various functions and the specific components underlying age differences in performance remain little understo...

  10. Age Dependent Face Recognition using Eigenface

    Directory of Open Access Journals (Sweden)

    Hlaing Htake Khaung Tin

    2013-10-01

    Full Text Available Face recognition is the most successful form of human surveillance. Face recognition technology, is being used to improve human efficiency when recognition faces, is one of the fastest growing fields in the biometric industry. In the first stage, the age is classified into eleven categories which distinguish the person oldness in terms of age. In the second stage of the process is face recognition based on the predicted age. Age prediction has considerable potential applications in human computer interaction and multimedia communication. In this paper proposes an Eigen based age estimation algorithm for estimate an image from the database. Eigenface has proven to be a useful and robust cue for age prediction, age simulation, face recognition, localization and tracking. The scheme is based on an information theory approach that decomposes face images into a small set of characteristic feature images called eigenfaces, which may be thought of as the principal components of the initial training set of face images. The eigenface approach used in this scheme has advantages over other face recognition methods in its speed, simplicity, learning capability and robustness to small changes in the face image.

  11. Optimal Aging and Death

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan; Strulik, Holger

    representative consumer is subject to physiological aging. In modeling aging we draw on recent research in the fields of biology and medicine. The speed of the aging process, and thus the time of death, are endogenously determined by optimal health investments. We calibrate the model to US data and proceed to...

  12. Optimal Aging and Death

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Strulik, Holger

    2010-01-01

    This study introduces physiological aging into a simple model of optimal intertemporal consumption. In this endeavor we draw on the natural science literature on aging. According to the purposed theory, the speed of the aging process and the time of death are endogenously determined by optimal...

  13. Peroxisomes in yeast ageing

    NARCIS (Netherlands)

    Kumar, Sanjeev

    2015-01-01

    Ageing is characterized by the progressive decline in cellular functions that eventually leads to death. In human, ageing is associated with several age-related diseases such as cancer, cardiovascular disorders and neurodegenerative diseases. Over the years, research performed in several simpler sho

  14. PerformAge

    DEFF Research Database (Denmark)

    Fristrup, Tine

    2012-01-01

    ), I do not want to paint a uniformly rosy picture of aging and old age, but unfold an opening up of life taking the heroines and heroes of aging life to the open road in search of themselves and new roles in life as a quest of self-knowledge, self-development – a role for the future. Different...

  15. Hodgkin's disease and age

    DEFF Research Database (Denmark)

    Specht, L.; Nissen, N.I.

    1989-01-01

    modality, stage, and total tumour burden, whereas age had no prognostic significance. With regard to death from Hodgkin's disease only age and total tumour burden had independent significance. The significance of age would seem to stem from the fact that some older patients could not be given adequate...

  16. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I;

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling of...... aged bones....

  17. Time Estimation Deficits in Childhood Mathematics Difficulties

    Science.gov (United States)

    Hurks, Petra P. M.; van Loosbroek, Erik

    2014-01-01

    Time perception has not been comprehensively examined in mathematics difficulties (MD). Therefore, verbal time estimation, production, and reproduction were tested in 13 individuals with MD and 16 healthy controls, matched for age, sex, and intellectual skills. Individuals with MD performed comparably to controls in time reproduction, but showed a…

  18. Idade de segregação do lenho juvenil e adulto pela variação da massa específica de açoita-cavalo Estimating the age of demarcation of young and mature wood in açoita-cavalo

    Directory of Open Access Journals (Sweden)

    Matheus Lemos de Peres

    2012-09-01

    Full Text Available O presente trabalho teve como objetivo estimar a idade de segregação do lenho de Luehea divaricata Mart. (açoita-cavalo por meio da variação radial da massa específica. Para o desenvolvimento do estudo, foram coletadas dez árvores de duas regiões do Estado do Rio Grande do Sul. Foi retirado um disco por árvore, com aproximadamente 2cm de espessura a 0,10m de altura do tronco. De cada disco, retirou-se, com auxílio de uma serra-fita, uma bagueta central de 2,0cm de largura, bem orientada no sentido radial, incluindo a medula no centro, dividiu-se então a bagueta em duas amostras "A" e "B". A massa específica foi obtida da relação entre peso seco e volume úmido. O volume úmido foi determinado de acordo com a norma ASTM D 2395 - 93, 1995. A segregação dos lenhos foi encontrada por regressão linear simples dos dados de variação da massa específica no sentido medula-casca. Foi feita uma regressão linear na faixa crescente dos dados e outra na faixa decrescente. A intersecção das retas extrapoladas foi adotada como idade de segregação. Os resultados obtidos mostraram que o lenho de açoita-cavalo segrega em aproximadamente 26 anos para a região da Depressão Central e 23 anos para a região da Encosta Superior do Nordeste. Nos dados de variação de massa específica, foi feita uma análise de variância multifatorial. Constatou-se que há diferença significativa entre lenhos e entre regiões. Por outro lado, as amostras A e B de cada árvore não foram estatisticamente diferentes entre si.This study aims to estimate the age of segregation of young and mature wood of Luehea divaricata Mart., using the radial variation of specific gravity. To the development of this study were collected ten trees from two regions of the state of Rio Grande do Sul. Discs with thickness of 2cm at 0.1m of height from the base of the trunk were used. From each disk, with the aid of a band saw, a central ribbon 2.0cm wide, and oriented in the

  19. Hardware Accelerated Power Estimation

    CERN Document Server

    Coburn, Joel; Raghunathan, Anand

    2011-01-01

    In this paper, we present power emulation, a novel design paradigm that utilizes hardware acceleration for the purpose of fast power estimation. Power emulation is based on the observation that the functions necessary for power estimation (power model evaluation, aggregation, etc.) can be implemented as hardware circuits. Therefore, we can enhance any given design with "power estimation hardware", map it to a prototyping platform, and exercise it with any given test stimuli to obtain power consumption estimates. Our empirical studies with industrial designs reveal that power emulation can achieve significant speedups (10X to 500X) over state-of-the-art commercial register-transfer level (RTL) power estimation tools.

  20. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system is...... implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V with a...