Use of reflectance spectrophotometry and colorimetry in a general linear model for the determination of the age of bruises.

PubMed

Hughes, Vanessa K; Langlois, Neil E I

2010-12-01

Bruises can have medicolegal significance such that the age of a bruise may be an important issue. This study sought to determine if colorimetry or reflectance spectrophotometry could be employed to objectively estimate the age of bruises. Based on a previously described method, reflectance spectrophotometric scans were obtained from bruises using a Cary 100 Bio spectrophotometer fitted with a fibre-optic reflectance probe. Measurements were taken from the bruise and a control area. Software was used to calculate the first derivative at 490 and 480 nm; the proportion of oxygenated hemoglobin was calculated using an isobestic point method and a software application converted the scan data into colorimetry data. In addition, data on factors that might be associated with the determination of the age of a bruise: subject age, subject sex, degree of trauma, bruise size, skin color, body build, and depth of bruise were recorded. From 147 subjects, 233 reflectance spectrophotometry scans were obtained for analysis. The age of the bruises ranged from 0.5 to 231.5 h. A General Linear Model analysis method was used. This revealed that colorimetric measurement of the yellowness of a bruise accounted for 13% of the bruise age. By incorporation of the other recorded data (as above), yellowness could predict up to 32% of the age of a bruise-implying that 68% of the variation was dependent on other factors. However, critical appraisal of the model revealed that the colorimetry method of determining the age of a bruise was affected by skin tone and required a measure of the proportion of oxygenated hemoglobin, which is obtained by spectrophotometric methods. Using spectrophotometry, the first derivative at 490 nm alone accounted for 18% of the bruise age estimate. When additional factors (subject sex, bruise depth and oxygenation of hemoglobin) were included in the General Linear Model this increased to 31%-implying that 69% of the variation was dependent on other factors. This indicates that spectrophotometry would be of more use that colorimetry for assessing the age of bruises, but the spectrophotometric method used needs to be refined to provide useful data regarding the estimated age of a bruise. Such refinements might include the use of multiple readings or utilizing a comprehensive mathematical model of the optics of skin.

Exploring oxidative ageing behaviour of hydrocarbons using ab initio molecular dynamics analysis

NASA Astrophysics Data System (ADS)

Pan, Tongyan; Cheng, Cheng

2016-06-01

With a proper approximate solution to the Schrödinger Equation of a multi-electron system, the method of ab initio molecular dynamics (AIMD) performs first-principles molecular dynamics analysis without pre-defining interatomic potentials as are mandatory in traditional molecular dynamics analyses. The objective of this study is to determine the oxidative-ageing pathway of petroleum asphalt as a typical hydrocarbon system, using the AIMD method. This objective was accomplished in three steps, including (1) identifying a group of representative asphalt molecules to model, (2) determining an atomistic modelling method that can effectively simulate the production of critical functional groups in oxidative ageing of hydrocarbons and (3) evaluating the oxidative-ageing pathway of a hydrocarbon system. The determination of oxidative-ageing pathway of hydrocarbons was done by tracking the generations of critical functional groups in the course of oxidative ageing. The chemical elements of carbon, nitrogen and sulphur all experience oxidative reactions, producing polarised functional groups such as ketones, aldehydes or carboxylic acids, pyrrolic groups and sulphoxides. The electrostatic forces of the polarised groups generated in oxidation are responsible for the behaviour of aged hydrocarbons. The developed AIMD model can be used for modelling the ageing of generic hydrocarbon polymers and developing antioxidants without running expensive experiments.

Accuracy of MRI skeletal age estimation for subjects 12-19. Potential use for subjects of unknown age.

PubMed

Serinelli, Serenella; Panebianco, Valeria; Martino, Milvia; Battisti, Sofia; Rodacki, Karina; Marinelli, Enrico; Zaccagna, Fulvio; Semelka, Richard C; Tomei, Ernesto

2015-05-01

In forensic practice, there is a growing need for accurate methods of age estimation, especially in the cases of young individuals of unknown age. Age can be estimated through somatic features that are universally considered associated with chronological age. Unfortunately, these features do not always coincide with the real chronological age: for these reasons that age determination is often very difficult. Our aim is to evaluate accuracy of skeletal age estimation using Tomei's MRI method in subjects between 12 and 19 years old for forensic purposes. Two investigators analyzed MRI images of the left hand and wrist of 77 male and 74 female caucasian subjects, without chronic diseases or developmental disorders, whose age ranged from 12 to 19 years. Skeletal maturation was determined by two operators, who analyzed all MRI images separately, in blinded fashion to the chronological age. Inter-rater agreement was measured with Pearson (R (2)) coefficient. One of the examiners repeated the evaluation after 6 months, and intraobserver variation was analyzed. Bland-Altman plots were used to determine mean differences between skeletal and chronological age. Inter-rater agreement Pearson coefficient showed a good linear correlation, respectively, 0.98 and 0.97 in males and females. Bland-Altman analysis demonstrated that the differences between chronological and skeletal age are not significant. Spearman's correlation coefficient showed good correlation between skeletal and chronological age both in females (R (2) = 0.96) and in males (R (2) = 0.94). Our results show that MRI skeletal age is a reproducible method and has good correlation with chronological age.

Age versus size determination of radial variation in wood specific gravity : lessons from eccentrics

Treesearch

G. Bruce Williamson; Michael C. Wiemann

2011-01-01

Radial increases in wood specific gravity have been shown to characterize early successional trees from tropical forests. Here, we develop and apply a novel method to test whether radial increases are determined by tree age or tree size. The method compares the slopes of specific gravity changes across a short radius and a long radius of trees with eccentric trunks. If...

Long-term secular trend of skeletal maturation of Taiwanese children between agricultural (1960s) and contemporary (after 2000s) generations using the Tanner-Whitehouse 3 (TW3) method.

PubMed

Hsieh, Chi-Wen; Liu, Tzu-Chiang; Jong, Tai-Lang; Tiu, Chui-Mei

2013-01-01

The Tanner-Whitehouse (TW) method is one of the well-known techniques in determining the bone age. According to the objectivity of TW3, the secular trend was investigated to discover whether the skeletal maturation of Taiwanese children between two generations was different. The large-scale database of Taiwan was collected. The first group, called mid-1960s, included 265 boys and 295 girls in the agricultural generation (between 1966 and 1967). The second group, called mid-2000s, includes 114 boys and 616 girls in the contemporary generation (after 2000s). The bone age was determined by three radiologists using the carpals-only system of the TW3 method and by two physicians using the Greulich and Pyle method. A comparison of the means (independent-samples t-test) was applied by examining the difference of the children's skeletal maturation between the two generations in the same chronological age. The significant difference was considered while the p-value was 0.05 or less (95% confidence interval). A significant difference of the mean bone age (by, on average, three radiologists using the TW3 method) between the mid-1960s and mid-2000s in the same gender and chronological age was presented by the independent-samples t-test (p<0.001 with 95% confidence interval), and the bone age, determined by the TW3 method, of the mid-2000s group was higher than that of the mid-1960s group. This scenario corresponded with the children's bone age determined by pediatricians. Besides, it deserved to notice that the bone age of boys in the mid-2000s was larger than that of the girls in the mid-1960s. Furthermore, by comparing the environmental condition, we suspect that the difference of bone age of children between the two generations was attributed to the discrepancy in nutrition and socioeconomic variation during the four decades in Taiwan. The study presents that the secular trend of skeletal maturation of children in the mid-2000s is faster than that in the mid-1960s.

Radioactive and magnetic investigations

NASA Technical Reports Server (NTRS)

Heye, D.; Beiersdorf, H.

1979-01-01

Age and growth pattern determination of manganese nodules were explored. Two methods are discussed: (1) measurement of the presence of radioactive iodine isotopes; which is effective only up to 3.105 years, and (2) measurements of magnetism. The growth rates of three nodules were determined. The surface of the nodule was recent, and the overall age of the nodule could be determined with accuracy of better than 30%. Measurement of paleomagnetic effect was attempted to determine wider age ranges, however, the measured sign changes could not be interpreted as paleomagnetic reversals.

Comparison of Methods for Determining Aerobic Exercise Intensity Using Heart Rate in Acute Leukemia Patients Prior to Induction Chemotherapy

PubMed Central

Story, Christina; Bryant, Ashley Leak; Phillips, Brett; Bailey, Charlotte; Shields, Edgar W.; Battaglini, Claudio

2018-01-01

Introduction Cardiopulmonary exercise testing (CPET), the gold standard of cardiopulmonary evaluation, is used to determine VO2 levels at different aerobic exercise training intensities; however, it may not be feasible to conduct CPET in all clinical settings. Aims To compare the heart rate reserve (HRR) and percent of 220-age methods for prescribing cycle ergometry exercise intensity using heart rate (HR) against the HRs obtained during a CPET in adults undergoing treatment for acute leukemia (AL). Methods In this exploratory study, part of a larger randomized controlled trial, 14 adults with AL completed CPET on a cycle ergometer with indirect calorimetry within 96 hr of admission to a cancer hospital to determine VO2peak and HR corresponding to low (40% VO2peak), moderate (60% VO2peak), and high (75% VO2peak) exercise intensities. Analyses of variance were used to compare estimated HR for each intensity level using the HRR and percent of 220-age methods with HR determined via VO2peak. Results HR corresponding to low-intensity exercise differed significantly across all three methods (p ≤ .05). No significant differences were observed between HR estimated via the percent of 220-age method and determined via VO2peak at moderate (100 ± 8 and 113 ± 24 bpm, p = .122) or high intensities (125 ± 10 and 123 ± 25 bpm, p = .994). Conclusion In adults with AL, HR-based methods for defining aerobic exercise intensities should be used with caution. At low intensity, neither should be used, while at moderate and high intensities, the percent of 220-age equation might serve as an adequate substitute for CPET. PMID:26933148

Age determination of fish from scales; method and application to fish cultural problems

USGS Publications Warehouse

Hile, Ralph

1936-01-01

THE SCIENCE of "scale reading", or determination of the age of fish from the examination of their scales, is less than 40 years old. Yet today the publications on the subject are to be numbered by the hundreds, and there is scarcely any phase of fish and fishery work that has not been benefited by this powerful tool for investigation. Fish culture is no exception to this rule. It is because of the increasing interest of fish culturists in scale reading and their numerous requests for information on the subject, that I have been asked to prepare a brief discussion of the method of age determination in fishes.

Guinea Pig Ciliary Muscle Development

PubMed Central

Pucker, Andrew D.; Carpenter, Ashley R.; McHugh, Kirk M.; Mutti, Donald O.

2014-01-01

Purpose The purpose of this study was to develop a method for quantifying guinea pig ciliary muscle volume (CMV) and to determine its relationship to age and ocular biometric measurements. Methods Six albino guinea pigs eyes were collected at each of five ages (n=30 eyes). Retinoscopy and photography were used to document refractive error, eye size, and eye shape. Serial sections through the excised eyes were made and then labeled with an α-smooth muscle actin antibody. The CM was then visualized with an Olympus BX51 microscope, reconstructed with Stereo Investigator (MBF Bioscience) and analyzed using Neurolucida Explorer (MBF Bioscience). Full (using all sections) and partial (using a subset of sections) reconstruction methods were used to determine CMV. Results There was no significant difference between the full and partial volume determination methods (P = 0.86). The mean CMV of the 1, 10, 20, 30, and 90-day old eyes was 0.40 ± 0.16 mm3, 0.48 ± 0.13 mm3, 0.67 ± 0.15 mm3, 0.86 ± 0.35 mm3, and 1.09 ± 0.63 mm3, respectively. CMV was significantly correlated with log age (P = 0.001), ocular length (P = 0.003), limbal circumference (P = 0.01), and equatorial diameter (P = 0.003). It was not correlated with refractive error (P = 0.73) or eye shape (P = 0.60). Multivariate regression determined that biometric variables were not significantly associated with CMV after adjustment for age. Conclusions Three-dimensional reconstruction was an effective means of determining CMV. These data provide evidence that CM growth occurs with age in tandem with eye size in normal albino guinea pigs. Additional work is needed to determine the relationship between CMV and abnormal ocular growth. PMID:24901488

In situ 10Be-26Al exposure ages at Meteor Crater, Arizona

USGS Publications Warehouse

Nishiizumi, K.; Kohl, C.P.; Shoemaker, E.M.; Arnold, J.R.; Klein, J.; Fink, D.; Middleton, R.

1991-01-01

A new method of dating the surface exposure of rocks from in situ production of 10Be and 26Al has been applied to determine the age of Meteor Crater, Arizona. A lower bound on the crater age of 49,200 ?? 1,700 years has been obtained by this method. ?? 1991.

A comparison of the validity of the Demirjian, Willems, Nolla and Häävikko methods in determination of chronological age of 5-15 year-old Indian children.

PubMed

Hegde, Sapna; Patodia, Akash; Dixit, Uma

2017-08-01

Demirjian's method has been the most popular and extensively tested radiographic method of age estimation. More recently, Willems' method has been reported to be a better predictor of age. Nolla's and Häävikko's methods have been used to a lesser extent. Very few studies have compared all four methods in non-Indian and Indian populations. Most Indian research is limited by inadequate sample sizes, age structures and grouping and different approaches to statistical analysis. The present study aimed to evaluate and compare the validity of the Demirjian, Willems, Nolla and Häävikko methods in determination of chronological age of 5 to 15 year-old Indian children. In this cross-sectional observational study, four methods were compared for validity in estimating the age of 1200 Indian children aged 5-15 years. Demirjian's method overestimated age by +0.24 ± 0.80, +0.11 ± 0.81 and +0.19 ± 0.80 years in boys, girls and the total sample, respectively. With Willems' method, overestimations of +0.09 ± 0.80, +0.08 ± 0.80 and +0.09 ± 0.80 years were obtained in boys, girls and the total sample, respectively. Nolla's method underestimated age by -0.13 ± 0.80, -0.30 ± 0.82 and -0.20 ± 0.81 years in boys, girls and the total sample, respectively. Häävikko's method underestimated age by -0.17 ± 0.80, -0.29 ± 0.83 and -0.22 ± 0.82 years in boys, girls and the total sample, respectively. Statistically significant differences were observed between dental and chronological ages with all methods (p < 0.001). Significant gender-based differences were observed with all methods except Willems' (p < 0.05). Gender-specific regression formulae were derived for all methods. Willems' method most accurately estimated age, followed by Demirjian's, Nolla's and Häävikko's methods. All four methods could be applicable for estimating age in the present population, mean prediction errors being lower than 0.30 years (3.6 months). Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Clinical Characteristics and Low Vision Rehabilitation Methods for Partially Sighted School-Age Children

PubMed Central

Özen Tunay, Zuhal; Çalışkan, Deniz; İdil, Aysun; Öztuna, Derya

2016-01-01

Objectives: To determine the clinical features and the distribution of diagnosis in partially sighted school-age children, to report the chosen low vision rehabilitation methods and to emphasize the importance of low vision rehabilitation. Materials and Methods: The study included 150 partially sighted children between the ages of 6 and 18 years. The distribution of diagnosis, accompanying ocular findings, visual acuity of the children both for near and distance with and without low vision devices, and the methods of low vision rehabilitation (for distance and for near) were determined. The demographic characteristics of the children and the parental consanguinity were recorded. Results: The mean age of children was 10.6 years and the median age was 10 years; 88 (58.7%) of them were male and 62 (41.3%) of them were female. According to distribution of diagnoses among the children, the most frequent diagnosis was hereditary fundus dystrophies (36%) followed by cortical visual impairment (18%). The most frequently used rehabilitation methods were: telescopic lenses (91.3%) for distance vision; magnifiers (38.7%) and telemicroscopic systems (26.0%) for near vision. A significant improvement in visual acuity both for distance and near vision were determined with low vision aids. Conclusion: A significant improvement in visual acuity can be achieved both for distance and near vision with low vision rehabilitation in partially sighted school-age children. It is important for ophthalmologists and pediatricians to guide parents and children to low vision rehabilitation. PMID:27800263

Objective evaluation of cervical vertebral bone age' its reliability in comparison with hand-wrist bone age: by TW3 method.

PubMed

Prasad, Cms Krishna; Reddy, Vamsi Nilay; Sreedevi, Gojja; Ponnada, Swaroopa Rani; Priya, K Padma; Naik, B Raveendra

2013-09-01

The aim of this study was to establish the validity of a new method for evaluating skeletal maturation by assessing the 3rd and 4th cervical vertebrae seen in the cephalometric radiograph. This study consisted of a sample of 50 patients in the age group of 8 to 14 years of age. Chronologically, they were divided into six groups, based on the age consisting of a minimum of six to a maximum of 10 subjects. All the patients included in the study were females. The selected subjects were clinically examined and then age and date of birth of the patient in years and months was noted. Then lateral cephalograms and hand-wrist radiographs of the patient were taken on the same day with good clarity and contrast. The results suggested that cervical vertebral bone age on cephalometric radiographs calculated with this method is as reliable at estimating bone age as is the Tanner-Whitehouse 3 (TW3) method on hand-wrist radiographs. By determining the cervical vertebral bone age, skeletal maturity can be evaluated in a detailed and objective manner with cephalometric radiographs. The ability to accurately appraise skeletal maturity from cervical vertebral maturation, without the need for additional radiographs, has the potential to improve orthodontic diagnostic and therapeutic decisions. The technique's simplicity and ease of use should encourage this method as a frst level diagnostic tool to assess skeletal maturation. Clinical signifcance: This study revealed that the timing and sequence of ossifcation of the bones in hand and wrist and cervical vertebrae were able to relate the skeletal development of the various skeletal maturity indicators to a child's development. This method provided a mean with which one can determine the skeletal maturity of a person and thereby determine whether the possibility of potential growth existed.

Isotopic composition analysis and age dating of uranium samples by high resolution gamma ray spectrometry

NASA Astrophysics Data System (ADS)

Apostol, A. I.; Pantelica, A.; Sima, O.; Fugaru, V.

2016-09-01

Non-destructive methods were applied to determine the isotopic composition and the time elapsed since last chemical purification of nine uranium samples. The applied methods are based on measuring gamma and X radiations of uranium samples by high resolution low energy gamma spectrometric system with planar high purity germanium detector and low background gamma spectrometric system with coaxial high purity germanium detector. The ;Multigroup γ-ray Analysis Method for Uranium; (MGAU) code was used for the precise determination of samples' isotopic composition. The age of the samples was determined from the isotopic ratio 214Bi/234U. This ratio was calculated from the analyzed spectra of each uranium sample, using relative detection efficiency. Special attention is paid to the coincidence summing corrections that have to be taken into account when performing this type of analysis. In addition, an alternative approach for the age determination using full energy peak efficiencies obtained by Monte Carlo simulations with the GESPECOR code is described.

On the behavior of certain ink aging curves.

PubMed

Cantú, Antonio A

2017-09-01

This work treats writing inks, particularly ballpoint pen inks. It reviews those ink aging methods that are based on the analysis (measurement) of ink solvents (e.g., 2-phenoxyethanol, which is the most common among ballpoint pen inks). Each method involves measurements that are components of an ink aging parameter associated with the method. Only mass independent parameters are considered. An ink solvent from an ink that is on an air-exposed substrate will evaporate at a decreasing rate and is never constant as the ink ages. An ink aging parameter should reflect this behavior. That is, the graph of a parameter's experimentally-determined values plotted against ink age (which yields the ink aging curve) should show this behavior. However, some experimentally-determined aging curves contain outlying points that are below or above where they should be or points corresponding to different ages that have the same ordinate (parameter value). Such curves, unfortunately, are useless since such curves show that an ink can appear older or younger than what it should be in one or more of its points or have the same age in two or more of its points. This work explains that one cause of this unexpected behavior is that the parameter values were improperly determined such as when a measurement is made of an ink solvent that is not completely extracted (removed) from an ink sample with a chosen extractor such as dry heat or a solvent. Copyright © 2017 Elsevier B.V. All rights reserved.

Non-invasive prediction of bloodstain age using the principal component and a back propagation artificial neural network

NASA Astrophysics Data System (ADS)

Sun, Huimin; Meng, Yaoyong; Zhang, Pingli; Li, Yajing; Li, Nan; Li, Caiyun; Guo, Zhiyou

2017-09-01

The age determination of bloodstains is an important and immediate challenge for forensic science. No reliable methods are currently available for estimating the age of bloodstains. Here we report a method for determining the age of bloodstains at different storage temperatures. Bloodstains were stored at 37 °C, 25 °C, 4 °C, and  -20 °C for 80 d. Bloodstains were measured using Raman spectroscopy at various time points. The principal component and a back propagation artificial neural network model were then established for estimating the age of the bloodstains. The results were ideal; the square of correlation coefficient was up to 0.99 (R 2  >  0.99) and the root mean square error of the prediction at lowest reached 55.9829 h. This method is real-time, non-invasive, non-destructive and highly efficiency. It may well prove that Raman spectroscopy is a promising tool for the estimation of the age of bloodstains.

[Development and prospect on skeletal age evaluation methods of X-ray film].

PubMed

Wang, Ya-hui; Zhu, Guang-you; Qiao, Ke; Bian, Shi-zhong; Fan, Li-hua; Cheng, Yi-bin; Ying, Chong-liang; Shen, Yan

2007-10-01

The traditional methods of skeletal age estimation mainly include Numeration, Atlas, and Counting scores. In recent years, other new methods were proposed by several scholars. Utilizing image logical characteristics of X-ray film to extrapolate skeletal age is a key means by present forensic medicine workers in evaluating skeletal age. However, there exist some variations when we present the conclusion of skeletal age as an "evidence" directly to the Justice Trial Authority. In order to enhance the accuracy of skeletal age determination, further investigation for appropriate methodology should be undertaken. After a collective study of pertinent domestic and international literatures, we present this review of the research and advancement on skeletal age evaluation methods of X-ray film.

Ages of LMC star clusters using ASAD2

NASA Astrophysics Data System (ADS)

Asa'd, Randa S.; Vazdekis, Alexandre; Zeinelabdin, Sami

2016-04-01

We use ASAD2, the new version of ASAD (Analyzer of Spectra for Age Determination), to obtain the age and reddening of 27 Large Magellanic Cloud (LMC) clusters from full fitting of integrated spectra using different statistical methods [χ2 and Kolmogorov-Smirnov (KS) test] and a set of stellar population models including GALAXEV and MILES. We show that our results are in good agreement with the colour-magnitude diagram (CMD) ages for both models, and that metallicity does not affect the age determination for the full spectrum fitting method regardless of the model used for ages with log (age/year) < 9. We discuss the results obtained by the two statistical results for both GALAXEV and MILES versus three factors: age, signal-to-noise ratio and resolution (full width at half maximum). The predicted reddening values when using the χ2 minimization method are within the range found in the literature for resolved clusters (I.e. <0.35); however the KS test can predict E(B - V) higher values. The sharp spectrum transition originated at ages around the supergiants contribution, at either side of the AGB peak around log (age/year) 9.0 and log (age/year) 7.8 are limiting our ability to provide values in agreement with the CMD estimates and as a result the reddening determination is not accurate. We provide the detailed results of four clusters spanning a wide range of ages. ASAD2 is a user-friendly program available for download on the Web and can be immediately used at http://randaasad.wordpress.com/asad-package/.

Last menstrual period provides the best estimate of gestation length for women in rural Guatemala.

PubMed

Neufeld, Lynnette M; Haas, Jere D; Grajéda, Ruben; Martorell, Reynaldo

2006-07-01

The accurate estimation of gestational age in field studies in rural areas of developing countries continues to present difficulties for researchers. Our objective was to determine the best method for gestational age estimation in rural Guatemala. Women of childbearing age from four communities in rural Guatemala were invited to participate in a longitudinal study. Gestational age at birth was determined by an early second trimester measure of biparietal diameter, last menstrual period (LMP), the Capurro neonatal examination and symphysis-fundus height (SFH) for 171 women-infant pairs. Regression modelling was used to determine which method provided the best estimate of gestational age using ultrasound as the reference. Gestational age estimated by LMP was within +/-14 days of the ultrasound estimate for 94% of the sample. LMP-estimated gestational age explained 46% of the variance in gestational age estimated by ultrasound whereas the neonatal examination explained only 20%. The results of this study suggest that, when trained field personnel assist women to recall their date of LMP, this date provides the best estimate of gestational age. SFH measured during the second trimester may provide a reasonable alternative when LMP is unavailable.

Limitations of backward integration method for asteroid family age estimation

NASA Astrophysics Data System (ADS)

Radović, Viktor

2017-10-01

Determining the age of an asteroid family is important as it gives us a better understanding of the dynamics, formation and collisional evolution of a family. So far, a few methods for determining the age of a family have been developed. The most accurate one is probably the backward integration method (BIM) that works very well for young families. In this paper, we try to study its characteristics and limitations in more detail using a fictional asteroid family. The analysis is performed with two numerical packages: orbfit and mercury. We studied the clustering of the secular angles Ω and ϖ and obtained linear relationship between the depth of the clustering and the age of the family. Our results suggest that the BIM could be successfully applied only to families not older than 18 Myr.

The reliability of Fishman method of skeletal maturation for age estimation in children of South Indian population.

PubMed

Mohammed, Rezwana Begum; Kalyan, V Siva; Tircouveluri, Saritha; Vegesna, Goutham Chakravarthy; Chirla, Anil; Varma, D Maruthi

2014-07-01

Determining the age of a person in the absence of documentary evidence of birth is essential for legal and medico-legal purpose. Fishman method of skeletal maturation is widely used for this purpose; however, the reliability of this method for people with all geographic locations is not well-established. In this study, we assessed various stages of carpal and metacarpal bone maturation and tested the reliability of Fishman method of skeletal maturation to estimate the age in South Indian population. We also evaluated the correlation between the chronological age (CA) and predicted age based on the Fishman method of skeletal maturation. Digital right hand-wrist radiographs of 330 individuals aged 9-20 years were obtained and the skeletal maturity stage for each subject was determined using Fishman method. The skeletal maturation indicator scores were obtained and analyzed with reference to CA and sex. Data was analyzed using the SPSS software package (version 12, SPSS Inc., Chicago, IL, USA). The study subjects had a tendency toward late maturation with the mean skeletal age (SA) estimated being significantly lowers (P < 0.05) than the mean CA at various skeletal maturity stages. Nevertheless, significant correlation was observed in this study between SA and CA for males (r = 0.82) and females (r = 0.85). Interestingly, female subjects were observed to be advanced in SA compared with males. Fishman method of skeletal maturation can be used as an alternative tool for the assessment of mean age of an individual of unknown CA in South Indian children.

[Hard to accurately determine the age of children seeking asylum].

PubMed

Hjern, Anders; Ascher, Henry

2015-10-12

Many unaccompanied asylum seeking young people in Europe lack documents proving their age. X rays of the wrist and wisdom teeth are often used by European migration authorities to assess age in this situation. The large inter-individual differences in physical maturation during adolescence create such large margins of error for these methods that their informative value is very limited. The Swedish National Board of Health and Welfare should reconsider its previous position on these methods and examine the possibility to include psychosocial methods in these age assessment procedures.

The reliability of Fishman method of skeletal maturation for age estimation in children of South Indian population

PubMed Central

Mohammed, Rezwana Begum; Kalyan, V. Siva; Tircouveluri, Saritha; Vegesna, Goutham Chakravarthy; Chirla, Anil; Varma, D. Maruthi

2014-01-01

Introduction: Determining the age of a person in the absence of documentary evidence of birth is essential for legal and medico-legal purpose. Fishman method of skeletal maturation is widely used for this purpose; however, the reliability of this method for people with all geographic locations is not well-established. Aims and Objectives: In this study, we assessed various stages of carpal and metacarpal bone maturation and tested the reliability of Fishman method of skeletal maturation to estimate the age in South Indian population. We also evaluated the correlation between the chronological age (CA) and predicted age based on the Fishman method of skeletal maturation. Materials and Methods: Digital right hand-wrist radiographs of 330 individuals aged 9-20 years were obtained and the skeletal maturity stage for each subject was determined using Fishman method. The skeletal maturation indicator scores were obtained and analyzed with reference to CA and sex. Data was analyzed using the SPSS software package (version 12, SPSS Inc., Chicago, IL, USA). Results: The study subjects had a tendency toward late maturation with the mean skeletal age (SA) estimated being significantly lowers (P < 0.05) than the mean CA at various skeletal maturity stages. Nevertheless, significant correlation was observed in this study between SA and CA for males (r = 0.82) and females (r = 0.85). Interestingly, female subjects were observed to be advanced in SA compared with males. Conclusion: Fishman method of skeletal maturation can be used as an alternative tool for the assessment of mean age of an individual of unknown CA in South Indian children. PMID:25097402

Determination of Knowledge, Attitudes and Behaviors Regarding Factors Causing Home Accidents and Prevention in Mothers with a Child Aged 0-5 Years

ERIC Educational Resources Information Center

Akturk, Ümmühan; Erci, Behice

2016-01-01

Objective: In this study, it was aimed to determine knowledge, "attitudes" and "behaviors" in mothers with a child aged 0-5 years regarding factors causing "home accidents" and prevention. Method: The target population of the study consisted of mothers with a child aged 0-5 years who were admitted to pediatrics ward…

Reliability of third molar development for age estimation in Gujarati population: A comparative study

PubMed Central

Gandhi, Neha; Jain, Sandeep; Kumar, Manish; Rupakar, Pratik; Choyal, Kanaram; Prajapati, Seema

2015-01-01

Background: Age assessment may be a crucial step in postmortem profiling leading to confirmative identification. In children, Demirjian's method based on eight developmental stages was developed to determine maturity scores as a function of age and polynomial functions to determine age as a function of score. Aim: Of this study was to evaluate the reliability of age estimation using Demirjian's eight teeth method following the French maturity scores and Indian-specific formula from developmental stages of third molar with the help of orthopantomograms using the Demirjian method. Materials and Methods: Dental panoramic tomograms from 30 subjects each of known chronological age and sex were collected and were evaluated according to Demirjian's criteria. Age calculations were performed using Demirjian's formula and Indian formula. Statistical analysis used was Chi-square test and ANOVA test and the P values obtained were statistically significant. Results: There was an average underestimation of age with both Indian and Demirjian's formulas. The mean absolute error was lower using Indian formula hence it can be applied for age estimation in present Gujarati population. Also, females were ahead of achieving dental maturity than males thus completion of dental development is attained earlier in females. Conclusion: Greater accuracy can be obtained if population-specific formulas considering the ethnic and environmental variation are derived performing the regression analysis. PMID:26005298

Use of cervical vertebral dimensions for assessment of children growth.

PubMed

Caldas, Maria de Paula; Ambrosano, Gláucia Maria Bovi; Haiter-Neto, Francisco

2007-04-01

The purpose of this study was to investigate whether skeletal maturation using cephalometric radiographs could be used in a Brazilian population. The study population was selected from the files of the Oral Radiological Clinic of the Dental School of Piracicaba, Brazil and consisted of 128 girls and 110 boys (7.0 to 15.9 years old) who had cephalometric and hand-wrist radiographs taken on the same day. Cervical vertebral bone age was evaluated using the method described by Mito and colleagues in 2002. Bone age was assessed by the Tanner-Whitehouse (TW3) method and was used as a gold standard to determine the reliability of cervical vertebral bone age. An analysis of variance and Tukey's post-hoc test were used to compare cervical vertebral bone age, bone age and chronological age at 5% significance level. The analysis of the Brazilian female children data showed that there was a statistically significant difference (p<0.05) between cervical vertebral bone age and chronological age and between bone age and chronological age. However no statistically significant difference (p>0.05) was found between cervical vertebral bone age and bone age. Differently, the analysis of the male children data revealed a statistically significant difference (p<0.05) between cervical vertebral bone age and bone age and between cervical vertebral bone age and chronological age (p<0.05). The findings of the present study suggest that the method for objectively evaluating skeletal maturation on cephalometric radiographs by determination of vertebral bone age can be applied to Brazilian females only. The development of a new method to objectively evaluate cervical vertebral bone age in males is needed.

Clinical Characteristics and Low Vision Rehabilitation Methods for Partially Sighted School-Age Children.

PubMed

Özen Tunay, Zuhal; Çalışkan, Deniz; İdil, Aysun; Öztuna, Derya

2016-04-01

To determine the clinical features and the distribution of diagnosis in partially sighted school-age children, to report the chosen low vision rehabilitation methods and to emphasize the importance of low vision rehabilitation. The study included 150 partially sighted children between the ages of 6 and 18 years. The distribution of diagnosis, accompanying ocular findings, visual acuity of the children both for near and distance with and without low vision devices, and the methods of low vision rehabilitation (for distance and for near) were determined. The demographic characteristics of the children and the parental consanguinity were recorded. The mean age of children was 10.6 years and the median age was 10 years; 88 (58.7%) of them were male and 62 (41.3%) of them were female. According to distribution of diagnoses among the children, the most frequent diagnosis was hereditary fundus dystrophies (36%) followed by cortical visual impairment (18%). The most frequently used rehabilitation methods were: telescopic lenses (91.3%) for distance vision; magnifiers (38.7%) and telemicroscopic systems (26.0%) for near vision. A significant improvement in visual acuity both for distance and near vision were determined with low vision aids. A significant improvement in visual acuity can be achieved both for distance and near vision with low vision rehabilitation in partially sighted school-age children. It is important for ophthalmologists and pediatricians to guide parents and children to low vision rehabilitation.

Development of a SPME-GC-MS method for the determination of volatile compounds in Shanxi aged vinegar and its analytical characterization by aroma wheel.

PubMed

Zhu, Hong; Zhu, Jie; Wang, Lili; Li, Zaigui

2016-01-01

A solid-phase microextraction followed by gas chromatography-mass spectrometry method was developed to determine the volatile compounds in Shanxi aged vinegar. The optimal extraction conditions were: 50 °C for 20 min with a PDMS/DVB fiber. This analytical method was validated and showed satisfactory repeatability (0.5 %

A method for determining fire history in coniferous forests in the Mountain West

Treesearch

Stephen F. Arno; Kathy M. Sneck

1977-01-01

Describes a method for determining historic fire frequency, intensity, and size from cross sections collected from fire-scarred trees and tree age classes determined through increment borings. Tells how to interpret the influence of fire in stand composition and structure and how to identify effects of modern fire suppression.

Determining the Average Age of School Plant Building Space.

ERIC Educational Resources Information Center

Uerling, Donald F.

1984-01-01

Presents a method for calculating the age of the space in a specific building inventory, and suggests some practical applications. A fourfold procedure is provided for finding the average age of total building space. (TE)

A comparison of skeletal maturity assessed by radiological and ultrasonic methods.

PubMed

Utczas, Katinka; Muzsnai, Agota; Cameron, Noel; Zsakai, Annamaria; Bodzsar, Eva B

2017-07-08

The estimation of skeletal maturity is a useful tool in pediatric practice to determine the degree of delay or advancement in growth disorders and the effectiveness of treatment in conditions that influence linear growth. Skeletal maturity of children is commonly assessed using either Greulich-Pyle (GP) or Tanner-Whitehouse methods (TW2 and TW3). However, a less invasive ultrasonic method, that does not use ionizing radiation, has been suggested for use in epidemiological studies of skeletal maturity. The main purpose of the present study was to determine the accuracy of an ultrasonic method based on the GP maturity indicators compared to the standard GP radiographic method. Skeletal maturity of 1502 healthy children, aged from 6 to 18 years, was estimated by quantitative ultrasound and compared to GP bone ages estimated from left hand and wrist radiographs of a subsample of 47 randomly selected participants. The ultrasonic bone age estimation demonstrated very strong correlations with all the radiological age estimations. The correlation coefficients ranged between 0.895 and 0.958, and the strongest correlation of ultrasonic skeletal maturity estimation was found with the Tanner-Whitehouse RUS method. The ultrasonic bone age estimation is suggested for use between the chronological ages of 8.5-16.0 years in boys and 7.5-15.0 years in girls. The ultrasonic bone age estimation is suggested for use in epidemiological surveys since the sensitivity for screening for not normal bone development is appropriate, at least within the 8-15 years age interval. © 2017 Wiley Periodicals, Inc.

New method for evaluation of cervical vertebral maturation based on angular measurements.

PubMed

Alhadlaq, Adel M; Al-Shayea, Eman I

2013-04-01

To investigate the validity of a new approach to assess the cervical vertebral maturation based on angular measurements of the lower border concavity of cervical vertebral bodies. Hand-wrist and lateral cephalometric radiographs of 197 male subjects with age range of 10-15 years attending the orthodontic clinic at King Saud University, Riyadh, Kingdom of Saudi Arabia were utilized. The study was carried out between September 2009 and May 2011. The study sample was divided into 6 groups (group 1: 10 years to group 6: 15 years) based on the chronological age of the subject. The skeletal age of the subjects was determined using Greulich and Pyle's standard radiographic atlas, and skeletal maturation was assessed by Fishman's skeletal maturity indicators. The cervical vertebral maturation (CVM) of subjects was determined using angular measurements of the second, third, and fourth cervical vertebral bodies. The validity of the newly developed method was assessed by examining the correlation between CVM stages determined by the angular measurements and the skeletal maturation level as determined by the standard hand-wrist methods. A significant correlation (r=0.94) was found between the angular CVM stages and the skeletal age determined by Greulich and Pyle's atlas from hand-wrist radiographs. Also, a high correlation (r=0.94) was found between the angular CVM stages and the Fishman's hand-wrist skeletal maturity indicators. The new angular measurement approach to determine CVM is valid and has the potential to be applied in assessing skeletal maturity level in growing male children.

Determining 'age at death' for forensic purposes using human bone by a laboratory-based biomechanical analytical method.

PubMed

Zioupos, P; Williams, A; Christodoulou, G; Giles, R

2014-05-01

Determination of age-at-death (AAD) is an important and frequent requirement in contemporary forensic science and in the reconstruction of past populations and societies from their remains. Its estimation is relatively straightforward and accurate (±3yr) for immature skeletons by using morphological features and reference tables within the context of forensic anthropology. However, after skeletal maturity (>35yr) estimates become inaccurate, particularly in the legal context. In line with the general migration of all the forensic sciences from reliance upon empirical criteria to those which are more evidence-based, AAD determination should rely more-and-more upon more quantitative methods. We explore here whether well-known changes in the biomechanical properties of bone and the properties of bone matrix, which have been seen to change with age even after skeletal maturity in a traceable manner, can be used to provide a reliable estimate of AAD. This method charts a combination of physical characteristics some of which are measured at a macroscopic level (wet & dry apparent density, porosity, organic/mineral/water fractions, collagen thermal degradation properties, ash content) and others at the microscopic level (Ca/P ratios, osteonal and matrix microhardness, image analysis of sections). This method produced successful age estimates on a cohort of 12 donors of age 53-85yr (7 male, 5 female), where the age of the individual could be approximated within less than ±1yr. This represents a vastly improved level of accuracy than currently extant age estimation techniques. It also presents: (1) a greater level of reliability and objectivity as the results are not dependent on the experience and expertise of the observer, as is so often the case in forensic skeletal age estimation methods; (2) it is purely laboratory-based analytical technique which can be carried out by someone with technical skills and not the specialised forensic anthropology experience; (3) it can be applied worldwide following stringent laboratory protocols. As such, this technique contributes significantly to improving age estimation and therefore identification methods for forensic and other purposes. © 2013 Elsevier Ltd. All rights reserved.

Contraceptive use-effectiveness and the American adolescent.

PubMed

Lyle, K C; Segal, S J

1979-05-01

Contraceptive use-effectiveness is significantly shaped by the contraceptors' ages, for pregnancy rates are found to be a function of age. Teenagers are more failure prone than older contracepting women, regardless of method. This higher teenage failure rate can indicate clearly the use-effectiveness of various contraceptive methods. Consequently, both user and method (whether modern or traditional) determine outcome levels of contraceptive use-effectiveness.

Reliability of third molar development for age estimation in Gujarati population: A comparative study.

PubMed

Gandhi, Neha; Jain, Sandeep; Kumar, Manish; Rupakar, Pratik; Choyal, Kanaram; Prajapati, Seema

2015-01-01

Age assessment may be a crucial step in postmortem profiling leading to confirmative identification. In children, Demirjian's method based on eight developmental stages was developed to determine maturity scores as a function of age and polynomial functions to determine age as a function of score. Of this study was to evaluate the reliability of age estimation using Demirjian's eight teeth method following the French maturity scores and Indian-specific formula from developmental stages of third molar with the help of orthopantomograms using the Demirjian method. Dental panoramic tomograms from 30 subjects each of known chronological age and sex were collected and were evaluated according to Demirjian's criteria. Age calculations were performed using Demirjian's formula and Indian formula. Statistical analysis used was Chi-square test and ANOVA test and the P values obtained were statistically significant. There was an average underestimation of age with both Indian and Demirjian's formulas. The mean absolute error was lower using Indian formula hence it can be applied for age estimation in present Gujarati population. Also, females were ahead of achieving dental maturity than males thus completion of dental development is attained earlier in females. Greater accuracy can be obtained if population-specific formulas considering the ethnic and environmental variation are derived performing the regression analysis.

Spectral ageing in the era of big data: integrated versus resolved models

NASA Astrophysics Data System (ADS)

Harwood, Jeremy J.

2017-04-01

Continuous injection models of spectral ageing have long been used to determine the age of radio galaxies from their integrated spectrum; however, many questions about their reliability remain unanswered. With various large area surveys imminent (e.g. LOw Frequency ARray, MeerKAT, Murchison Widefield Array) and planning for the next generation of radio interferometers are well underway (e.g. next generation VLA, Square Kilometre Array), investigations of radio galaxy physics are set to shift away from studies of individual sources to the population as a whole. Determining if and how integrated models of spectral ageing can be applied in the era of big data is therefore crucial. In this paper, I compare classical integrated models of spectral ageing to recent well-resolved studies that use modern analysis techniques on small spatial scales to determine their robustness and validity as a source selection method. I find that integrated models are unable to recover key parameters and, even when known a priori, provide a poor, frequency-dependent description of a source's spectrum. I show a disparity of up to a factor of 6 in age between the integrated and resolved methods but suggest, even with these inconsistencies, such models still provide a potential method of candidate selection in the search for remnant radio galaxies and in providing a cleaner selection of high redshift radio galaxies in z - α selected samples.

Expanded plug method for developing circumferential mechanical properties of tubular materials

DOEpatents

Hendrich, William Ray; McAfee, Wallace Jefferson; Luttrell, Claire Roberta

2006-11-28

A method for determining the circumferential properties of a tubular product, especially nuclear fuel cladding, utilizes compression of a polymeric plug within the tubular product to determine strain stress, yield stress and other properties. The process is especially useful in the determination of aging properties such as fuel rod embrittlement after long burn-down.

Five radiographic methods for assessing skeletal maturity in a Spanish population: is there a correlation?

PubMed

Camacho-Basallo, Paula; Yáñez-Vico, Rosa-María; Solano-Reina, Enrique; Iglesias-Linares, Alejandro

2017-03-01

The need for accurate techniques of estimating age has sharply increased in line with the rise in illegal migration and the political, economic and socio-demographic problems that this poses in developed countries today. The methods routinely employed for determining chronological age are mainly based on determining skeletal maturation using radiological techniques. The objective of this study was to correlate five different methods for assessing skeletal maturation. 606 radiographs of growing patients were analyzed, and each patient was classified according to two cervical vertebral-based methods, two hand-wrist-based methods and one tooth-based method. Spearman's rank-order correlation coefficient was applied to assess the relationship between chronological age and the five methods of assessing maturation, as well as correlations between the five methods (p < 0.05). Spearman's rank correlation coefficients for chronological age and cervical vertebral maturation stage using both methods were 0.656/0.693 (p < 0.001), respectively, for males. For females, the correlation was stronger for both methods. The correlation coefficients for chronological age against the two hand-wrist assessment methods were statistically significant only for Fishman's method, 0.722 (p < 0.001) and 0.839 (p < 0.001), respectively for males and females. The cervical vertebral, hand-wrist and dental maturation methods of assessment were all found to correlate strongly with each other, irrespective of gender, except for Grave and Brown's method. The results found the strongest correlation between the second molars and females, and the second premolar and males. This study sheds light on and correlates with the five radiographic methods most commonly used for assessing skeletal maturation in a Spanish population in southern Europe.

Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method.

PubMed

Black, Stuart; Ferrell, Jack R

2017-02-07

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls cause an increase in viscosity (often referred to as 'aging') during storage of bio-oils. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Additionally, carbonyls are also responsible for coke formation in bio-oil upgrading processes. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here, we present a modification of the traditional carbonyl oximation procedures that results in less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. While traditional carbonyl oximation methods occur at room temperature, the Faix method presented here occurs at an elevated temperature of 80 °C.

in vivo quantification of white matter microstructure for use in aging: A focus on two emerging techniques

PubMed Central

Lamar, Melissa; Zhou, Xiaohong Joe; Charlton, Rebecca A.; Dean, Douglas; Little, Deborah; Deoni, Sean C

2013-01-01

Human brain imaging has seen many advances in the quantification of white matter in vivo. For example, these advances have revealed the association between white matter damage and vascular disease as well as their impact on risk for and development of dementia and depression in an aging population. Current neuroimaging methods to quantify white matter damage provide a foundation for understanding such age-related neuropathology; however, these methods are not as adept at determining the underlying microstructural abnormalities signaling at risk tissue or driving white matter damage in the aging brain. This review will begin with a brief overview of the use of diffusion tensor imaging (DTI) in understanding white matter alterations in aging before focusing in more detail on select advances in both diffusion-based methods and multi-component relaxometry techniques for imaging white matter microstructural integrity within myelin sheaths and the axons they encase. While DTI greatly extended the field of white matter interrogation, these more recent technological advances will add clarity to the underlying microstructural mechanisms that contribute to white matter damage. More specifically, the methods highlighted in this review may prove more sensitive (and specific) for determining the contribution of myelin versus axonal integrity to the aging of white matter in brain. PMID:24080382

Is the cervical vertebral maturation (CVM) method effective enough to replace the hand-wrist maturation (HWM) method in determining skeletal maturation?-A systematic review.

PubMed

Szemraj, Agnieszka; Wojtaszek-Słomińska, Anna; Racka-Pilszak, Bogna

2018-05-01

Chronological age provides only general information on the development of a child/adolescent. However, the biological age of the patient is more significant. One of the methods is the determination of the bone age based on the development of the hand and wrist bones. In 1972 a method for assessing cervical vertebral maturation on the cephalometric radiographs was introduced (CVM method). As a result, additional patient radiation was eliminated. Currently, this type of radiograph is routinely applied in orthodontic treatment. The aim of the study was to assess the usefulness of the CVM method and to verify the assumption, according to which the CVM method modified by Baccetti et al. may replace the method for the assessment of skeletal maturation based on a hand-wrist X-ray, which is known as the hand-wrist maturation (HWM) method. The present study reviewed the literature between 2006 and 2016. In the first stage of selection 905 articles were obtained. Finally, 10 articles were enrolled for the review. All of the studies presented a high level of correlation between the examined methods. In eight articles the researchers admitted that the CVM classification could replace the HWM method, known as the "gold standard". In two studies , the researchers suggested considering the CVM method an additional method despite its compatibility and usefulness. The lowest correlation coefficient was 0.616 and the highest 0.937. The assessment of the skeletal age with the CVM is done on a cephalometric radiograph, routinely used in orthodontic practice, which makes it easy to apply. The determination of features of only C2, C3 and C4 vertebrae is possible even if the patient wears an X-ray protective thyroid collar. Therefore, the radiation dose is minimized. The CVM method shows a high level of correlation with the HWM method. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluating the Risk of Tumors Diseases Based on Measurement of Urinary and Serumal Antioxidants Using the New Agar Diffusion Methods

PubMed Central

Zhou, Ying; Chen, Jing; Wang, Zhen

2017-01-01

Objectives. To discuss the characteristics of the amount of urinary total antioxidants in tumor diseases and the possibility of utilizing the changing regulation of urinary antioxidants to diagnose tumor diseases. Method. Urine and serum specimens from 130 healthy people were used to investigate the variation of antioxidant capacity against age. Urine and serum specimens from 44 unselected patients with tumors and 44 healthy people with same age background were used to explore the significance of urinary antioxidant capacity in clinic to diagnose tumor diseases. Potassium permanganate agar method and iodine starch method were used to determine the amount of total antioxidants. Results. In healthy people, more antioxidants in urine were measured in older people, while the results were opposite in serum. More antioxidants were found in urine of tumor patients than in healthy people with same age-range. Conclusions. According to the results of 130 measurements, the amount of antioxidants in urine varies by age. By using agar methods to measure antioxidants, the effect of age is required to be considered. Antioxidants levels from tumor patients were significantly higher than healthy individuals in urine. The combination of urine and serum to determine total antioxidants can better diagnose tumor diseases based on iodine starch method, with area under the receiver operating characteristics curve at 0.787. PMID:28458777

A new method for ageing Marbled Murrelets and the effect on productivity estimates

Treesearch

L.L. Long; C.J. Ralph; S. Miller

2001-01-01

Accurate knowledge of the number of newly-fledged juveniles offshore is critical to estimates of productivity of the threatened Marbled Murrelet (Brachyramphus marmoratus). We describe a method for collecting productivity data which allows researchers to objectively evaluate age determinations and their effect on juvenile percentages. This has the...

Genetic methods improve accuracy of gender determination in beaver

USGS Publications Warehouse

Williams, C.L.; Breck, S.W.; Baker, B.W.

2004-01-01

Gender identification of sexually monomorphic mammals can be difficult. We used analysis of zinc-finger protein (Zfx and Zfy) DNA regions to determine gender of 96 beavers (Castor canadensis) from 3 areas and used these results to verify gender determined in the field. Gender was correctly determined for 86 (89.6%) beavers. Incorrect assignments were not attributed to errors in any one age or sex class. Although methods that can be used in the field (such as morphological methods) can provide reasonably accurate gender assignments in beavers, the genetic method might be preferred in certain situations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lea, C.S.; Selvin, S.; Buffler, P.A.

This pilot study uses a unique method to calculate cumulative lifetime exposure to, ultraviolet radiation-b to determine if this refined method would indicate differences in lifetime cumulative UVB exposure between age and sex matched controls. Forty-four age and sex matched cases and controls demonstrated no significant difference in mean cumulative lifetime UVB exposure based on the duration and location of residence. This pilot study suggests that further analysis of the dataset should be conducted to determine if the cumulative lifetime exposure hypothesis is of primary importance regarding the association between UVB exposure and development of cutaneous malignant melanoma.

SABE Colombia: Survey on Health, Well-Being, and Aging in Colombia—Study Design and Protocol

PubMed Central

Corchuelo, Jairo; Curcio, Carmen-Lucia; Calzada, Maria-Teresa; Mendez, Fabian

2016-01-01

Objective. To describe the design of the SABE Colombia study. The major health study of the old people in Latin America and the Caribbean (LAC) is the Survey on Health, Well-Being, and Aging in LAC, SABE (from initials in Spanish: SAlud, Bienestar & Envejecimiento). Methods. The SABE Colombia is a population-based cross-sectional study on health, aging, and well-being of elderly individuals aged at least 60 years focusing attention on social determinants of health inequities. Methods and design were similar to original LAC SABE. The total sample size of the study at the urban and rural research sites (244 municipalities) was 23.694 elderly Colombians representative of the total population. The study had three components: (1) a questionnaire covering active aging determinants including anthropometry, blood pressure measurement, physical function, and biochemical and hematological measures; (2) a subsample survey among family caregivers; (3) a qualitative study with gender and cultural perspectives of quality of life to understand different dimensions of people meanings. Conclusions. The SABE Colombia is a comprehensive, multidisciplinary study of the elderly with respect to active aging determinants. The results of this study are intended to inform public policies aimed at tackling health inequalities for the aging society in Colombia. PMID:27956896

A Novel Method to Describe Early Offspring Body Mass Index (BMI) Trajectories and to Study Its Determinants

PubMed Central

Carles, Sophie; Charles, Marie-Aline; Forhan, Anne; Slama, Rémy; Heude, Barbara; Botton, Jérémie

2016-01-01

Background Accurately characterizing children’s body mass index (BMI) trajectories and studying their determinants is a statistical challenge. There is a need to identify early public health measures for obesity prevention. We describe a method that allows studies of the determinants of height, weight and BMI growth up to five years of age. We illustrated this method using maternal smoking during pregnancy as one of the early-life factors that is potentially involved in prenatal programming of obesity. Methods Individual height and weight trajectories were fitted using the Jenss-Bayley model on 28,381 and 30,515 measurements, respectively, from 1,666 children to deduce BMI trajectories. We assessed global associations between smoking and growth trajectories and cross-sectional associations at specific ages. Results Children exposed in late pregnancy had a 0.24 kg/m2 (95% confidence interval: 0.07, 0.41) higher BMI at 5 years of age compared with non-exposed children. Although the BMIs of children exposed during late pregnancy became significantly higher compared with those of non-exposed children from 2 years onwards, the trajectories began to diverge during the first weeks of life. Conclusion Our method is relevant for studies on the relationships between individual-level exposures and the dynamics and shapes of BMI growth during childhood, including key features such as instantaneous growth velocities and the age or BMI value at the BMI infancy peak that benefit from the monotonic pattern of height and weight growth. PMID:27327164

[Studies of the biological age in adult taiga ticks Ixodes persulcatus (Ixodinae)].

PubMed

Grigor'eva, L A

2013-01-01

The history of studies of the biological age in ixodid ticks is discussed. A method of estimation of the biological age in adult ticks of the genus Ixodes by the degree of fat inclusions in midgut cells and in the fat body is developed. An "age scale" for the determination of the calendar age was assumed.

Epigenetic estimation of age in humpback whales

PubMed Central

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

2014-01-01

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 R2 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

Cremated human and animal remains of the Roman period--microscopic method of analysis (Sepkovcica, Croatia).

PubMed

Hincak, Zdravka; Mihelić, Damir; Bugar, Aleksandra

2007-12-01

Human and animal cremated osteological remains from twelve graves of Roman Period from archaeological site Sepkovcica near Velika Gorica (Turopolje region, NW Croatia) were analysed. Beside the content of urns and grave pits, fillings of grave vessels like bowls, pots and amphoras from twentytwo grave samples were included in this study. The preservation of osteological and dental remains of human and animal origin was very poor, majority of fragments hardly reach lengths of 10 mm. Weight of each specimen barely exceeds 100 g per person. Apart from traditional macroscopic methods of analysing cremated remains, microscopic method for determination of age at death was also tested. Fragments of femoral bone diaphysis of eighteen persons whose remains had been found on the site were analysed. Person's age at death was presented in the range of five or ten years, and the long bone fragments of a child (infants) were detected. Taxonomic position for each analysed specimen was determined by microscopic analysis of animal cremated bones. Analysis results confirm validity of microscopic method in determination of age at death for human remains and taxonomic qualification of cremated animal remains from archaeological sites.

Determinants of Information Behaviour and Information Literacy Related to Healthy Eating among Internet Users in Five European Countries

ERIC Educational Resources Information Center

Niedzwiedzka, Barbara; Mazzocchi, Mario; Aschemann-Witzel, Jessica; Gennaro, Laura; Verbeke, Wim; Traill, W. Bruce

2014-01-01

Introduction: This study investigates how Europeans seek information related to healthy eating, what determines their information seeking and whether any problems are encountered in doing so. Method: A survey was administered through computer-assisted on-line web-interviewing. Respondents were grouped by age and sex (n = 3003, age +16) in Belgium,…

Academic Outcomes for School-Aged Children with Severe-Profound Hearing Loss and Early Unilateral and Bilateral Cochlear Implants

ERIC Educational Resources Information Center

Sarant, Julia Z.; Harris, David C.; Bennet, Lisa A.

2015-01-01

Purpose: This study sought to (a) determine whether academic outcomes for children who received early cochlear implants (CIs) are age appropriate, (b) determine whether bilateral CI use significantly improves academic outcomes, and (c) identify other factors that are predictive of these outcomes. Method: Forty-four 8-year-old children with…

Combining wrist age and third molars in forensic age estimation: how to calculate the joint age estimate and its error rate in age diagnostics.

PubMed

Gelbrich, Bianca; Frerking, Carolin; Weiss, Sandra; Schwerdt, Sebastian; Stellzig-Eisenhauer, Angelika; Tausche, Eve; Gelbrich, Götz

2015-01-01

Forensic age estimation in living adolescents is based on several methods, e.g. the assessment of skeletal and dental maturation. Combination of several methods is mandatory, since age estimates from a single method are too imprecise due to biological variability. The correlation of the errors of the methods being combined must be known to calculate the precision of combined age estimates. To examine the correlation of the errors of the hand and the third molar method and to demonstrate how to calculate the combined age estimate. Clinical routine radiographs of the hand and dental panoramic images of 383 patients (aged 7.8-19.1 years, 56% female) were assessed. Lack of correlation (r = -0.024, 95% CI = -0.124 to + 0.076, p = 0.64) allows calculating the combined age estimate as the weighted average of the estimates from hand bones and third molars. Combination improved the standard deviations of errors (hand = 0.97, teeth = 1.35 years) to 0.79 years. Uncorrelated errors of the age estimates obtained from both methods allow straightforward determination of the common estimate and its variance. This is also possible when reference data for the hand and the third molar method are established independently from each other, using different samples.

Rapid age determination of oysters using LA-ICP-MS line scans of shell Mg/Ca ratios

NASA Astrophysics Data System (ADS)

Gillikin, D. P.; Durham, S. R.; Goodwin, D. H.

2016-02-01

Magnesium to calcium (Mg/Ca) ratios exhibit a strong temperature dependence in foraminifera and corals, but not in bivalve mollusks. Various studies have reported Mg/Ca-temperature relationships with R2 values ranging from 0.3 to 0.8 and significantly different relationships for bivalves growing at different salinities. However, this poor temperature correlation does not render Mg/Ca data useless. A weak temperature dependence would allow time (seasons and years) to be determined along the growth axis of shells. This would provide information about age, growth rate and also allow other proxies to be aligned with time. Typically, oxygen isotopes (δ18O) are used to age shells without clear periodic growth lines, which is time consuming and expensive. Line scans using laser ablation systems can cover several centimeters of shell in a few minutes. We test this method on the resilifer of two oyster species (Crassostrea gigas and C. virginica) using a 193 nm Laser-Ablation-ICP-MS. Living oysters were collected from San Francisco Bay, North Carolina, South Carolina, and the Gulf of Mexico; fossil shells (Pleistocene) were also collected in South Carolina. Shells were sampled for δ18O values and Mg/Ca ratios. We use annual cycles in δ18O values to confidently determine age, then apply the Mg/Ca technique. Shells of both species exhibit annual cyclicity in Mg/Ca ratios using spot and line scan laser sampling, which matche the seasonal cyclicity determined using δ18O values. Results show a good correlation between ages determined using the different methods. We conclude that LA-ICP-MS line scans offer a rapid and inexpensive technique for determining age, growth rate, and timing of shell growth in oyster reslifers.

Prevalence of rheumatoid arthritis in persons 60 years of age and older in the United States: effect of different methods of case classification.

PubMed

Rasch, Elizabeth K; Hirsch, Rosemarie; Paulose-Ram, Ryne; Hochberg, Marc C

2003-04-01

To determine prevalence estimates for rheumatoid arthritis (RA) in noninstitutionalized older adults in the US. Prevalence estimates were compared using 3 different classification methods based on current classification criteria for RA. Data from the Third National Health and Nutrition Examination Survey (NHANES-III) were used to generate prevalence estimates by 3 classification methods in persons 60 years of age and older (n = 5,302). Method 1 applied the "n of k" rule, such that subjects who met 3 of 6 of the American College of Rheumatology (ACR) 1987 criteria were classified as having RA (data from hand radiographs were not available). In method 2, the ACR classification tree algorithm was applied. For method 3, medication data were used to augment case identification via method 2. Population prevalence estimates and 95% confidence intervals (95% CIs) were determined using the 3 methods on data stratified by sex, race/ethnicity, age, and education. Overall prevalence estimates using the 3 classification methods were 2.03% (95% CI 1.30-2.76), 2.15% (95% CI 1.43-2.87), and 2.34% (95% CI 1.66-3.02), respectively. The prevalence of RA was generally greater in the following groups: women, Mexican Americans, respondents with less education, and respondents who were 70 years of age and older. The prevalence of RA in persons 60 years of age and older is approximately 2%, representing the proportion of the US elderly population who will most likely require medical intervention because of disease activity. Different classification methods yielded similar prevalence estimates, although detection of RA was enhanced by incorporation of data on use of prescription medications, an important consideration in large population surveys.

X-ray studies of dynamic aging in an aluminum alloy subjected to severe plastic deformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sitdikov, V.D., E-mail: svil@mail.rb.ru; Laboratory for Mechanics of Bulk Nanomaterials, Saint Petersburg State University, 28 Universitetsky pr., Saint Petersburg 198504; Chizhov, P.S.

In this work, X-ray scattering methods were applied for a quantitative characterization of the microstructure of an aluminum alloy of the Al–Mg–Si system during dynamic aging realized through the high pressure torsion technique. A qualitative and quantitative phase analysis of the alloy was performed, together with Al alloy lattice parameter determination. From the reflections broadening the effective size of the coherent scattering domains and the lattice microstrain were determined in the framework of the Halder–Wagner approach. Using the method of small-angle X-ray scattering, the quantitative characteristics of the size, shape and spatial distribution of the secondary phase particles formed inmore » the Al alloy during dynamic aging were established. In order to validate the obtained results, the method of small-angle X-ray scattering was preliminarily tested on similar samples after artificial aging and compared with the results from small-angle neutron diffraction widely known in literature. - Highlights: • Spherical fcc β-Mg2Si precipitates formed in Al 6201 alloy during dynamic aging in the course of severe plastic deformation. • The size, shape and distribution of the precipitates due to artificial and dynamic aging were revealed by SAXS method. • Monoclinic needle-like β' precipitates and Al5FeSi intermetallic phase were detected in 6201 alloy after T6 treatment.« less

In vivo quantification of white matter microstructure for use in aging: a focus on two emerging techniques.

PubMed

Lamar, Melissa; Zhou, Xiaohong Joe; Charlton, Rebecca A; Dean, Douglas; Little, Deborah; Deoni, Sean C

2014-02-01

Human brain imaging has seen many advances in the quantification of white matter in vivo. For example, these advances have revealed the association between white matter damage and vascular disease as well as their impact on risk for and development of dementia and depression in an aging population. Current neuroimaging methods to quantify white matter damage provide a foundation for understanding such age-related neuropathology; however, these methods are not as adept at determining the underlying microstructural abnormalities signaling at risk tissue or driving white matter damage in the aging brain. This review will begin with a brief overview of the use of diffusion tensor imaging (DTI) in understanding white matter alterations in aging before focusing in more detail on select advances in both diffusion-based methods and multi-component relaxometry techniques for imaging white matter microstructural integrity within myelin sheaths and the axons they encase. Although DTI greatly extended the field of white matter interrogation, these more recent technological advances will add clarity to the underlying microstructural mechanisms that contribute to white matter damage. More specifically, the methods highlighted in this review may prove more sensitive (and specific) for determining the contribution of myelin versus axonal integrity to the aging of white matter in brain. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

A novel method for determining human ex vivo submaximal skeletal muscle mitochondrial function

PubMed Central

Hey-Mogensen, Martin; Gram, Martin; Jensen, Martin Borch; Lund, Michael Taulo; Hansen, Christina Neigaard; Scheibye-Knudsen, Morten; Bohr, Vilhelm A; Dela, Flemming

2015-01-01

Abstract Despite numerous studies, there is no consensus about whether mitochondrial function is altered with increased age. The novelty of the present study is the determination of mitochondrial function at submaximal activity rates, which is more physiologically relevant than the ex vivo functionality protocols used previously. Muscle biopsies were taken from 64 old or young male subjects (aged 60–70 or 20–30 years). Aged subjects were recruited as trained or untrained. Muscle biopsies were used for the isolation of mitochondria and subsequent measurements of DNA repair, anti-oxidant capacity and mitochondrial protein levels (complexes I–V). Mitochondrial function was determined by simultaneous measurement of oxygen consumption, membrane potential and hydrogen peroxide emission using pyruvate + malate (PM) or succinate + rotenone (SR) as substrates. Proton leak was lower in aged subjects when determined at the same membrane potential and was unaffected by training status. State 3 respiration was lower in aged untrained subjects. This effect, however, was alleviated in aged trained subjects. H2O2 emission with PM was higher in aged subjects, and was exacerbated by training, although it was not changed when using SR. However, with a higher manganese superoxide dismuthase content, the trained aged subjects may actually have lower or similar mitochondrial superoxide emission compared to the untrained subjects. We conclude that ageing and the physical activity level in aged subjects are both related to changes in the intrinsic functionality of the mitochondrion in skeletal muscle. Both of these changes could be important factors in determining the metabolic health of the aged skeletal muscle cell. Key points The present study utilized a novel method aiming to investigate mitochondrial function in human skeletal muscle at submaximal levels and at a predefined membrane potential. The effect of age and training status was investigated using a cross-sectional design. Ageing was found to be related to decreased leak regardless of training status. Increased training status was associated with increased mitochondrial hydrogen peroxide emission. PMID:26096709

Determination of N epsilon-(carboxymethyl)lysine in foods and related systems.

PubMed

Ames, Jennifer M

2008-04-01

The sensitive and specific determination of advanced glycation end products (AGEs) is of considerable interest because these compounds have been associated with pro-oxidative and proinflammatory effects in vivo. AGEs form when carbonyl compounds, such as glucose and its oxidation products, glyoxal and methylglyoxal, react with the epsilon-amino group of lysine and the guanidino group of arginine to give structures including N epsilon-(carboxymethyl)lysine (CML), N epsilon-(carboxyethyl)lysine, and hydroimidazolones. CML is frequently used as a marker for AGEs in general. It exists in both the free or peptide-bound forms. Analysis of CML involves its extraction from the food (including protein hydrolysis to release any peptide-bound adduct) and determination by immunochemical or instrumental means. Various factors must be considered at each step of the analysis. Extraction, hydrolysis, and sample clean-up are all less straight forward for food samples, compared to plasma and tissue. The immunochemical and instrumental methods all have their advantages and disadvantages, and no perfect method exists. Currently, different procedures are being used in different laboratories, and there is an urgent need to compare, improve, and validate methods.

The production rate of cosmogenic 21-Ne in chondrites deduced from 81-Kr measurements

NASA Technical Reports Server (NTRS)

Schultz, L.; Freundel, M.

1986-01-01

Cosmogenic Ne-21 is used widely to calculate exposure ages of stone meteorites. In order to do so, the production rate P(21) must be known. This rate, however, is dependent on the chemical composition of the meteorite as well as the mass of, and position within, the meteoroid during its exposure to the cosmic radiation. Even for a mean shielding the production rates determined from measurments of different radionuclides vary by a factor of two. A method that can be used to determine exposure ages of meteorites that avoids shielding and chemical composition corrections is the -81-Kr-Kr-method. However, for chondrites, in many cases, the direct determination of production rates for the Kr isotopes is prevented by the trapped gases and the neutron effects on bromine. Therefore, this method was applied to four eucrite falls and then their 81-Kr-83-Kr-ages were compared to their cosmogenic Ne-21 and Ar-38 concentrations. The eucrites Bouvante-le-Haut, Juvinas, Sioux County, and Stannern were chosen for these measurements because of their similar chemical composition regarding the major elements.

BMI was found to be a consistent determinant related to misreporting of energy, protein and potassium intake using self-report and duplicate portion methods.

PubMed

Trijsburg, Laura; Geelen, Anouk; Hollman, Peter Ch; Hulshof, Paul Jm; Feskens, Edith Jm; Van't Veer, Pieter; Boshuizen, Hendriek C; de Vries, Jeanne Hm

2017-03-01

As misreporting, mostly under-reporting, of dietary intake is a generally known problem in nutritional research, we aimed to analyse the association between selected determinants and the extent of misreporting by the duplicate portion method (DP), 24 h recall (24hR) and FFQ by linear regression analysis using the biomarker values as unbiased estimates. For each individual, two DP, two 24hR, two FFQ and two 24 h urinary biomarkers were collected within 1·5 years. Also, for sixty-nine individuals one or two doubly labelled water measurements were obtained. The associations of basic determinants (BMI, gender, age and level of education) with misreporting of energy, protein and K intake of the DP, 24hR and FFQ were evaluated using linear regression analysis. Additionally, associations between other determinants, such as physical activity and smoking habits, and misreporting were investigated. The Netherlands. One hundred and ninety-seven individuals aged 20-70 years. Higher BMI was associated with under-reporting of dietary intake assessed by the different dietary assessment methods for energy, protein and K, except for K by DP. Men tended to under-report protein by the DP, FFQ and 24hR, and persons of older age under-reported K but only by the 24hR and FFQ. When adjusted for the basic determinants, the other determinants did not show a consistent association with misreporting of energy or nutrients and by the different dietary assessment methods. As BMI was the only consistent determinant of misreporting, we conclude that BMI should always be taken into account when assessing and correcting dietary intake.

The Demirjian versus the Willems method for dental age estimation in different populations: A meta-analysis of published studies

PubMed Central

2017-01-01

Background The accuracy of radiographic methods for dental age estimation is important for biological growth research and forensic applications. Accuracy of the two most commonly used systems (Demirjian and Willems) has been evaluated with conflicting results. This study investigates the accuracies of these methods for dental age estimation in different populations. Methods A search of PubMed, Scopus, Ovid, Database of Open Access Journals and Google Scholar was undertaken. Eligible studies published before December 28, 2016 were reviewed and analyzed. Meta-analysis was performed on 28 published articles using the Demirjian and/or Willems methods to estimate chronological age in 14,109 children (6,581 males, 7,528 females) age 3–18 years in studies using Demirjian’s method and 10,832 children (5,176 males, 5,656 females) age 4–18 years in studies using Willems’ method. The weighted mean difference at 95% confidence interval was used to assess accuracies of the two methods in predicting the chronological age. Results The Demirjian method significantly overestimated chronological age (p<0.05) in males age 3–15 and females age 4–16 when studies were pooled by age cohorts and sex. The majority of studies using Willems’ method did not report significant overestimation of ages in either sex. Overall, Demirjian’s method significantly overestimated chronological age compared to the Willems method (p<0.05). The weighted mean difference for the Demirjian method was 0.62 for males and 0.72 for females, while that of the Willems method was 0.26 for males and 0.29 for females. Conclusion The Willems method provides more accurate estimation of chronological age in different populations, while Demirjian’s method has a broad application in terms of determining maturity scores. However, accuracy of Demirjian age estimations is confounded by population variation when converting maturity scores to dental ages. For highest accuracy of age estimation, population-specific standards, rather than a universal standard or methods developed on other populations, need to be employed. PMID:29117240

Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Black, Stuart; Ferrell, Jack R.

We know that carbonyl compounds, present in bio-oils, are responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls cause an increase in viscosity (often referred to as 'aging') during storage of bio-oils. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. In addition, carbonyls are also responsible for coke formation in bio-oil upgrading processes. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation havemore » long been used for the determination of carbonyl content in pyrolysis bio-oils. Here, we present a modification of the traditional carbonyl oximation procedures that results in less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. And while traditional carbonyl oximation methods occur at room temperature, the Faix method presented here occurs at an elevated temperature of 80 degrees C.« less

Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method

DOE PAGES

Black, Stuart; Ferrell, Jack R.

2017-02-07

We know that carbonyl compounds, present in bio-oils, are responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls cause an increase in viscosity (often referred to as 'aging') during storage of bio-oils. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. In addition, carbonyls are also responsible for coke formation in bio-oil upgrading processes. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation havemore » long been used for the determination of carbonyl content in pyrolysis bio-oils. Here, we present a modification of the traditional carbonyl oximation procedures that results in less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. And while traditional carbonyl oximation methods occur at room temperature, the Faix method presented here occurs at an elevated temperature of 80 degrees C.« less

Correlation among chronologic age, skeletal maturity, and dental age.

PubMed

Sukhia, Rashna H; Fida, Mubassar

2010-01-01

To determine the correlation among chronologic age, skeletal maturity, and dental age in reference to both sexes. In 380 subjects (147 males and 233 females) between 7 and 17 years of age, skeletal maturity was assessed using the cervical vertebral maturation stages described by Baccetti et al. Dental age was determined using the Demirjian method. The correlation between skeletal maturity and chronologic age on one side and between skeletal maturity and dental age on the other was assessed with Spearman rank correlation coefficients. Pearson correlation coefficients were used to assess the correlation between chronologic and dental age. For both sexes, significant correlations among chronologic age, skeletal maturity, and dental age were found. The mandibular first premolar had the highest correlation with skeletal maturation in both sexes. As skeletal maturity and dental age are significantly correlated, tooth development may be used to assess a patient's skeletal maturity at an early age. © 2011 BY QUINTESSENCE PUBLISHING CO, INC.

Indicators of Dysphagia in Aged Care Facilities

ERIC Educational Resources Information Center

Pu, Dai; Murry, Thomas; Wong, May C. M.; Yiu, Edwin M. L.; Chan, Karen M. K.

2017-01-01

Purpose: The current cross-sectional study aimed to investigate risk factors for dysphagia in elderly individuals in aged care facilities. Method: A total of 878 individuals from 42 aged care facilities were recruited for this study. The dependent outcome was speech therapist-determined swallowing function. Independent factors were Eating…

Modeling and measuring extravascular hemoglobin: aging contusions

NASA Astrophysics Data System (ADS)

Lines, Collin; Kim, Oleg; Duffy, Susan; Alber, Mark; Crawford, Gregory P.

2011-07-01

Medical expertise is frequently elicited to aid in determining the age and the cause of the trauma or injury. Child protection and law enforcement frequently rely on the physical assessment of the trauma which involves delineating intentional from unintentional types of trauma. Recent studies have shown that current methods to assess the age of traumatic injuries are highly inaccurate and do not give reasonable predictions. Hemoglobin is one of the strongest chromophores in human tissues. Transport of hemoglobin and its breakdown products in tissue determines the spectrophotometric characteristics of the skin and its variations in time. Therefore, measurements of diffuse reflective spectra of the skin allow noninvasive screening. This paper reviews potential transmission and diffusive reflection spectroscopy based techniques and predictive and quantitative modeling methods assisting in efficient retrieval of the age of extravascular contusions. This paper then presents a novel Monte Carlo technique for 3D photon tracking and blood transport model. In future studies, clinically obtained spectra will be used to validate the model as well as fine-tune coefficients for absorption. It is the goal of this study to develop a model that would allow a non-invasive, accurate determination of the age of a bruise.

Age determination of raccoons

USGS Publications Warehouse

Grau, G.A.; Sanderson, G.C.; Rogers, J.P.

1970-01-01

Age criteria, based on 61 skulls and eye lenses from 103 known-age captives, are described for separating raccoons (Procyon lotor) into eight age-classes as follows: young-of-the-year, 1, 2, 3, 4, 5, 6-7, > 7 years. Criteria studied were eye lens nitrogen, cranial suture closure, tooth wear and incisor cementum layers. Lens nitrogen increased rapidly up to 12 months of age, but at much reduced rate thereafter. Total lens nitrogen was useful only in separating young-of-the-year from adults. The closure sequence for five cranial sutures accurately divided the total known-age sample of males into seven groups, and the adults into five groups. The tooth wear criteria divided the known-age sample into five relative age groups, but aging of individuals by this method was inaccurate. Histological sectioning of known-age teeth was the best method of observing layering in the cementum tissue. The technique of basing estimation of age on cementum ring counts, although subjective, was accurate for aging individuals through their fourth year but tended to underestimate the age of animals over 4 years old. However, suture closure or tooth wear can be used to identify males over 4 years old. In field studies, technical difficulties limit the utility of age estimation by cementum layers. Maximum root thickness of the lower canine was accurate in determining the sex of individuals from 5 months to ,at least 48 months of age.

[Assessment of skin aging grading based on computer vision].

PubMed

Li, Lingyu; Xue, Jinxia; He, Xiangqian; Zhang, Sheng; Fan, Chu

2017-06-01

Skin aging is the most intuitive and obvious sign of the human aging processes. Qualitative and quantitative determination of skin aging is of particular importance for the evaluation of human aging and anti-aging treatment effects. To solve the problem of subjectivity of conventional skin aging grading methods, the self-organizing map (SOM) network was used to explore an automatic method for skin aging grading. First, the ventral forearm skin images were obtained by a portable digital microscope and two texture parameters, i.e. , mean width of skin furrows and the number of intersections were extracted by image processing algorithm. Then, the values of texture parameters were taken as inputs of SOM network to train the network. The experimental results showed that the network achieved an overall accuracy of 80.8%, compared with the aging grading results by human graders. The designed method appeared to be rapid and objective, which can be used for quantitative analysis of skin images, and automatic assessment of skin aging grading.

Optical bandgap of single- and multi-layered amorphous germanium ultra-thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Pei; Zaslavsky, Alexander; Longo, Paolo

2016-01-07

Accurate optical methods are required to determine the energy bandgap of amorphous semiconductors and elucidate the role of quantum confinement in nanometer-scale, ultra-thin absorbing layers. Here, we provide a critical comparison between well-established methods that are generally employed to determine the optical bandgap of thin-film amorphous semiconductors, starting from normal-incidence reflectance and transmittance measurements. First, we demonstrate that a more accurate estimate of the optical bandgap can be achieved by using a multiple-reflection interference model. We show that this model generates more reliable results compared to the widely accepted single-pass absorption method. Second, we compare two most representative methods (Taucmore » and Cody plots) that are extensively used to determine the optical bandgap of thin-film amorphous semiconductors starting from the extracted absorption coefficient. Analysis of the experimental absorption data acquired for ultra-thin amorphous germanium (a-Ge) layers demonstrates that the Cody model is able to provide a less ambiguous energy bandgap value. Finally, we apply our proposed method to experimentally determine the optical bandgap of a-Ge/SiO{sub 2} superlattices with single and multiple a-Ge layers down to 2 nm thickness.« less

Examination of the Relationship of Community College Opticianry Student Outcomes with Instructional Delivery Methods and Student Age

ERIC Educational Resources Information Center

Underwood, William B.; Hernandez-Gantes, Victor M.

2017-01-01

The purpose of this study was to determine whether student outcomes are a function of participation in different modes of delivery and student age in an Opticianry program at the community college level. The three instructional delivery methods were traditional face-to-face instruction, online delivery, and a hybrid format where students take…

Epigenetic estimation of age in humpback whales.

PubMed

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. © 2014 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.

Health monitoring method for composite materials

DOEpatents

Watkins, Jr., Kenneth S.; Morris, Shelby J [Hampton, VA

2011-04-12

An in-situ method for monitoring the health of a composite component utilizes a condition sensor made of electrically conductive particles dispersed in a polymeric matrix. The sensor is bonded or otherwise formed on the matrix surface of the composite material. Age-related shrinkage of the sensor matrix results in a decrease in the resistivity of the condition sensor. Correlation of measured sensor resistivity with data from aged specimens allows indirect determination of mechanical damage and remaining age of the composite component.

Estimation of Correlation between Chronological Age, Skeletal Age and Dental Age in Children- A Cross-sectional Study

PubMed Central

Macha, Madhulika; Lamba, Bharti; Muthineni, Sridhar; Margana, Pratap Gowd Jai Shankar; Chitoori, Prasad

2017-01-01

Introduction In the modern era, identification and determination of age is imperative for diversity of reasons that include disputed birth records, premature delivery, legal issues and for validation of birth certificate for school admissions, adoption, marriage, job and immigration. Several growth assessment parameters like bone age, dental age and the combination of both have been applied for different population with variable outcomes. It has been well documented that the chronological age does not necessarily correlate with the maturational status of a child. Hence, efforts were made to determine a child’s developmental age by using dental age (calcification of teeth) and skeletal age (skeletal maturation). Aim The present study was aimed to correlate the chronological age, dental age and skeletal age in children from Southeastern region of Andhra Pradesh, India. Materials and Methods Out of the total 900 screened children, only 100 subjects between age groups of 6-14 years with a mean age of 11.3±2.63 for males and 10.77±2.24 for females were selected for the study. Dental age was calculated by Demirjian method and skeletal age by modified Middle Phalanx of left hand third finger (MP3) method. Pearson’s and Spearman’s correlation tests were done to estimate the correlation between chronological, dental and skeletal ages among study population. Results There was a significant positive correlation between chronological age, dental age and all stages of MP3 among males. Similar results were observed in females, except for a non-significant moderate correlation between chronological age and dental age in the H stage of the MP3 region. Conclusion The results of the present study revealed correlation with statistical significance (p<0.05) between chronological, dental and skeletal ages among all the subjects (48 males and 52 females) and females attained maturity earlier than males in the present study population. PMID:29207822

Dental radiographic indicators, a key to age estimation

PubMed Central

Panchbhai, AS

2011-01-01

Objective The present review article is aimed at describing the radiological methods utilized for human age identification. Methods The application and importance of radiological methods in human age assessment was discussed through the literature survey. Results Following a literature search, 46 articles were included in the study and the relevant information is depicted in the article. Dental tissue is often preserved indefinitely after death. Implementation of radiography is based on the assessment of the extent of calcification of teeth and in turn the degree of formation of crown and root structures, along with the sequence and the stages of eruption. Several radiological techniques can be used to assist in both individual and general identification, including determination of gender, ethnic group and age. The radiographic method is a simpler and cheaper method of age identification compared with histological and biochemical methods. Radiographic and tomographic images have become an essential aid for human identification in forensic dentistry, particularly with the refinement of techniques and the incorporation of information technology resources. Conclusion Based on an appropriate knowledge of the available methods, forensic dentists can choose the most appropriate since the validity of age estimation crucially depends on the method used and its proper application. The multifactorial approach will lead to optimum age assessment. The legal requirements also have to be considered. PMID:21493876

Optical dating of tsunami-laid sand from an Oregon coastal lake

USGS Publications Warehouse

Ollerhead, J.; Huntley, D.J.; Nelson, A.R.; Kelsey, H.M.

2001-01-01

Optical ages for five samples of tsunami-laid sand from an Oregon coastal lake were determined using an infrared optical-dating method on K-feldspar separates and, as a test of accuracy, compared to ages determined by AMS 14C dating of detrital plant fragments found in the same beds. Two optical ages were about 20% younger than calibrated 14C ages of about 3.1 and 4.3 ka. Correction of the optical ages using measured anomalous fading rates brings them into agreement with the 14C ages. The approach used holds significant promise for improving the accuracy of infrared optical-dating methods. Luminescence data for the other three samples result in optical age limits much greater than the 14C ages. These data provide a textbook demonstration of the correlation between scatter in the luminescence intensity of individual sample aliquots and their normalization values that is expected when the samples contain sand grains not adequately exposed to daylight just prior to or during deposition and burial. Thus, the data for these three samples suggest that the tsunamis eroded young and old sand deposits before dropping the sand in the lake. ?? 2001 Elsevier Science Ltd. All rights reserved.

Determination of efficiency of an aged HPGe detector for gaseous sources by self absorption correction and point source methods

NASA Astrophysics Data System (ADS)

Sarangapani, R.; Jose, M. T.; Srinivasan, T. K.; Venkatraman, B.

2017-07-01

Methods for the determination of efficiency of an aged high purity germanium (HPGe) detector for gaseous sources have been presented in the paper. X-ray radiography of the detector has been performed to get detector dimensions for computational purposes. The dead layer thickness of HPGe detector has been ascertained from experiments and Monte Carlo computations. Experimental work with standard point and liquid sources in several cylindrical geometries has been undertaken for obtaining energy dependant efficiency. Monte Carlo simulations have been performed for computing efficiencies for point, liquid and gaseous sources. Self absorption correction factors have been obtained using mathematical equations for volume sources and MCNP simulations. Self-absorption correction and point source methods have been used to estimate the efficiency for gaseous sources. The efficiencies determined from the present work have been used to estimate activity of cover gas sample of a fast reactor.

Manuka honey protects middle-aged rats from oxidative damage

PubMed Central

Jubri, Zakiah; Rahim, Noor Baitee Abdul; Aan, Goon Jo

2013-01-01

OBJECTIVE: This study aimed to determine the effect of manuka honey on the oxidative status of middle-aged rats. METHOD: Twenty-four male Sprague-Dawley rats were divided into young (2 months) and middle-aged (9 months) groups. They were further divided into two groups each, which were either fed with plain water (control) or supplemented with 2.5 g/kg body weight of manuka honey for 30 days. The DNA damage level was determined via the comet assay, the plasma malondialdehyde level was determined using high performance liquid chromatography, and the antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, glutathione peroxidase and catalase) were determined spectrophotometrically in the erythrocytes and liver. The antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl and ferric reducing/antioxidant power assays, and the total phenolic content of the manuka was analyzed using UV spectrophotometry and the Folin-Ciocalteu method, respectively. RESULTS: Supplementation with manuka honey reduced the level of DNA damage, the malondialdehyde level and the glutathione peroxidase activity in the liver of both the young and middle-aged groups. However, the glutathione peroxidase activity was increased in the erythrocytes of middle-aged rats given manuka honey supplementation. The catalase activity was reduced in the liver and erythrocytes of both young and middle-aged rats given supplementation. Manuka honey was found to have antioxidant activity and to have a high total phenolic content. These findings showed a strong correlation between the total phenolic content and antioxidant activity. CONCLUSIONS: Manuka honey reduces oxidative damage in young and middle-aged rats; this effect could be mediated through the modulation of its antioxidant enzyme activities and its high total phenolic content. Manuka honey can be used as an alternative supplement at an early age to improve the oxidative status. PMID:24270958

Identification of osteocalcin as a permanent aging constituent of the bone matrix: basis for an accurate age at death determination.

PubMed

Ritz, S; Turzynski, A; Schütz, H W; Hollmann, A; Rochholz, G

1996-01-12

Age at death determination based on aspartic acid racemization in dentin has been applied successfully in forensic odontology for several years now. An age-dependent accumulation of D-aspartic acid has also recently been demonstrated in bone osteocalcin, one of the most abundant noncollagenous proteins of the organic bone matrix. Evaluation of these initial data on in vivo racemization of aspartic acid in bone osteocalcin was taken a step further. After purification of osteocalcin from 53 skull bone specimens, the extent of aspartic acid racemization in this peptide was determined. The D-aspartic acid content of purified bone osteocalcin exhibited a very close relationship to age at death. This confirmed identification of bone osteocalcin as a permanent, 'aging' peptide of the organic bone matrix. Its D-aspartic acid content may be used as a measure of its age and hence that of the entire organism. The new biochemical approach to determination of age at death by analyzing bone is complex and demanding from a methodologic point of view, but appears to be superior in precision and reproducibility to most other methods applicable to bone.

Results of interlaboratory comparison of fission-track age standards: Fission-track workshop-1984

USGS Publications Warehouse

Miller, D.S.; Duddy, I.R.; Green, P.F.; Hurford, A.J.; Naeser, C.W.

1985-01-01

Five samples were made available as standards for the 1984 Fission Track Workshop held in the summer of 1984 (Rensselaer Polytechnic Institute, Troy, New York). Two zircons, two apatites and a sphene were distributed prior to the meeting to 40 different laboratories. To date, 24 different analysts have reported results. The isotopic ages of the standards ranged from 16.8 to 98.7 Myr. Only the statement that the age of each sample was less than 200 Myr was provided with the set of standards distributed. Consequently, each laboratory was required to use their laboratory's accepted treatment (irradiation level, etching conditions, counting conditions, etc.) for these samples. The results show that some workers have serious problems in achieving accurate age determinations. This emphasizes the need to calibrate experimental techniques and counting procedures against age standards before unknown ages are determined. Any fission-track age determination published or submitted for publication can only be considered reliable if it is supported by evidence of consistent determinations on age standards. Only this can provide the scientific community with the background to build up confidence concerning the validity of the fission-track method. ?? 1985.

DNA-based approach to aging martens (Martes americana and M. caurina)

Treesearch

Jonathan N. Pauli; John P. Whiteman; Bruce G. Marcot; Terry M. McClean; Merav Ben-David

2011-01-01

Demographic structure is central to understanding the dynamics of animal populations. However, determining the age of free-ranging mammals is difficult, and currently impossible when sampling with noninvasive, genetic-based approaches. We present a method to estimate age class by combining measures of telomere lengths with other biologically meaningful covariates in a...

Emotional Reactivity, Regulation and Childhood Stuttering: A Behavioral and Electrophysiological Study

ERIC Educational Resources Information Center

Arnold, Hayley S.; Conture, Edward G.; Key, Alexandra P. F.; Walden, Tedra

2011-01-01

The purpose of this preliminary study was to assess whether behavioral and psychophysiological correlates of emotional reactivity and regulation are associated with developmental stuttering, as well as determine the feasibility of these methods in preschool-age children. Nine preschool-age children who stutter (CWS) and nine preschool-age children…

Inclusion of Aging in Rehabilitation Counseling Journals 2000-2012: A Content Analysis

ERIC Educational Resources Information Center

Kettaneh, Amani A.; Kinyanjui, Benson; Slevin, John R.; Slevin, Barbara; Harley, Debra A.

2015-01-01

Purpose: To conduct a content analysis of the rehabilitation counseling literature to identify articles published on aging. Method: To determine the number of articles that were published on aging in rehabilitation counseling journals, a content analysis of articles from 2000 through 2012 was performed. For purposes of this review, only…

UHPLC-high-resolution mass spectrometry determination of bisphenol A and plastic additives released by polycarbonate tableware: influence of ageing and surface damage.

PubMed

Bignardi, Chiara; Cavazza, Antonella; Laganà, Carmen; Salvadeo, Paola; Corradini, Claudio

2015-10-01

A new UHPLC-ESI-Orbitrap method for the identification and the quantitative determination of bisphenol A and some common additives employed in plastic manufacturing has been developed and validated. The method has been applied to evaluate the migration from 14 samples of tableware of different age and degree of surface damage, in both ethanol and isooctane (used as food simulants according to EU plastic regulation). Bisphenol A, three UV light absorbers, and one whitening agent were detected and quantified. Data were analyzed with the aim of exploring a possible correlation between bisphenol A and additives release, ageing, and surface integrity. A high correlation between age of samples, surface damage, and bisphenol A migration has been evaluated, while the release of additives was not correlated with other parameters. Obtained data showed for the first time that the release of bisphenol A seems to be more connected to ageing than to scratches and cracks occurrence. Graphical Abstract Bisphenol A and additives released by polycarbonate tableware: influence of ageing and surface damage.

Age-related changes of nasal cavity and conchae volumes and volume fractions in children: a stereological study.

PubMed

Ertekin, T; Değermenci, M; Nisari, M; Unur, E; Coşkun, A

2016-01-01

The anatomy of the human nasal cavity (NC) is complex and its structures are closely related to the functions of the NC. Studies which assessing the mean volumes of NC and conchae are very infrequent. The purpose of current study is to investigate development of NC and conchae according to age and sex by using stereological method. This retrospective volumetric study was carried out on 342 individuals (166 females and 176 males) between 0 and 18 years old with no pathological conditions or medical procedures that affected the skeletal morphology of the NC. Volumetric estimations were determined on computed tomography (CT) images using point-counting approach of stereological methods. NC, inferior nasal conchae (INC) and middle nasal conchae (MNC) volume measurements that obtained using point-counting method were increased with age in both sexes until 15 years old. Regardless of gender; no significant difference was determined between the left and right values for NC, conchae volumes and choanae measurements. Generally, significant differences were determined in NC and INC volumes according to gender after they reached maximum growth period. According to age the volume ratios of INC to NC and MNC to NC were ranged from 18% to 32% and 9% to15%, respectively. The current study demonstrated that the point-counting method is effective in determining volume estimation of NC and is well suited for CT studies. Our results could provide volumetric indexes for the NC and conchae, which could help the physician for both patient selections for surgery, and for the assessment of any surgical technique used to treatment of nasal obstruction. (.

Latitudinal and stock-specific variation in size- and age-at-maturity of female winter flounder, Pseudopleuronectes americanus, as determined with gonad histology

NASA Astrophysics Data System (ADS)

McBride, Richard S.; Wuenschel, Mark J.; Nitschke, Paul; Thornton, Grace; King, Jeremy R.

2013-01-01

Female winter flounder were examined using gonad histology to determine the adequacy of routine macroscopic maturity classification methods and to determine the spatial variation in size and age of maturity in U.S. waters. Sampling occurred in spring and autumn, which was adequate to collect immature, mature, spawning-active, and non-active females. Females were collected in coastal waters from Delaware Bay, USA, to the Scotian Shelf, Canada, including in Long Island Sound and on Georges Bank, which covered all U.S. stock areas. Mature fish spawned in spring, when gonads comprised up to 30% of the total body weight. Direct comparisons of maturity assignment by macroscopic versus microscopic methods demonstrated that both schemes are compatible, but the more cost-effective macroscopic method had trouble distinguishing larger immature from smaller resting females. Spatial comparisons, using gonad histology only, supported the existence of three stocks in U.S. waters, but also revealed significant variation in age at maturity within the two coastal stocks. Age-at-maturity was more variable than size-at-maturity, which is consistent with known stock-specific patterns of growth rates and a postulated life history tradeoff to delay maturity until a size threshold is reached. The within-stock variation in median age at maturity, about one year for coastal stocks, recommends further investigation of using static, stock-specific maturity ogives to calculate reference points for management.

Verification on the use of the Inoue method for precisely determining glomerular filtration rate in Philippine pediatrics

NASA Astrophysics Data System (ADS)

Magcase, M. J. D. J.; Duyan, A. Q.; Carpio, J.; Carbonell, C. A.; Trono, J. D.

2015-06-01

The objective of this study is to validate the Inoue method so that it would be the preferential choice in determining glomerular filtration rate (GFR) in Philippine pediatrics. The study consisted of 36 patients ranging from ages 2 months to 19 years old. The subjects used were those who were previously subjected to in-vitro method. The scintigrams of the invitro method was obtained and processed for split percentage uptake and for parameters needed to obtain Inoue GFR. The result of this paper correlates the Inoue GFR and In-vitro method (r = 0.926). Thus, Inoue method is a viable, simple, and practical technique in determining GFR in pediatric patients.

Simultaneous determination of furfural and its degradation products, furoic acid and maleic acid, in transformer oil by the reversed-phase vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography.

PubMed

Wang, Yifan; Li, Haiyan; Yang, Zhen; Zhang, Weijie; Hua, Jia

2017-12-01

To explore why the use of furfural as a transformer oil-paper insulation aging characteristic is problematic in real world application, we developed a method for the simultaneous determination of furfural, furoic acid, and maleic acid in transformer oil by reversed-phase vortex-assisted liquid-liquid microextraction combined with high-performance liquid chromatography. The conditions for the proposed method were optimized, and the obtained extract can be directly analyzed by high-performance liquid chromatography. The detection limits (signal-to-noise ratio = 3) of the method ranged from 1.0 to 4.6 μg/L, the enrichment factors for furfural, furoic acid, maleic acid, and fumaric acid were 4.6, 25.1, 15.6, and 17.5, respectively, and the recovery rates for three analytes (fumaric acid was undetected) range from 82.1 to 106.2%. The contents of furfural, furoic acid, and maleic acid resulted from accelerated aging of transformer insulation oil-paper were measured using the present method for the first time, and the aging samples were analyzed by liquid chromatography with mass spectrometry for the identification of furoic acid and maleic acid in the aging transformer oil samples. Using the optimal method, the target products of samples at different aging time were tracked and measured. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

What automated age estimation of hand and wrist MRI data tells us about skeletal maturation in male adolescents.

PubMed

Urschler, Martin; Grassegger, Sabine; Štern, Darko

2015-01-01

Age estimation of individuals is important in human biology and has various medical and forensic applications. Recent interest in MR-based methods aims to investigate alternatives for established methods involving ionising radiation. Automatic, software-based methods additionally promise improved estimation objectivity. To investigate how informative automatically selected image features are regarding their ability to discriminate age, by exploring a recently proposed software-based age estimation method for MR images of the left hand and wrist. One hundred and two MR datasets of left hand images are used to evaluate age estimation performance, consisting of bone and epiphyseal gap volume localisation, computation of one age regression model per bone mapping image features to age and fusion of individual bone age predictions to a final age estimate. Quantitative results of the software-based method show an age estimation performance with a mean absolute difference of 0.85 years (SD = 0.58 years) to chronological age, as determined by a cross-validation experiment. Qualitatively, it is demonstrated how feature selection works and which image features of skeletal maturation are automatically chosen to model the non-linear regression function. Feasibility of automatic age estimation based on MRI data is shown and selected image features are found to be informative for describing anatomical changes during physical maturation in male adolescents.

Age and Mass for 920 Large Magellanic Cloud Clusters Derived from 100 Million Monte Carlo Simulations

NASA Astrophysics Data System (ADS)

Popescu, Bogdan; Hanson, M. M.; Elmegreen, Bruce G.

2012-06-01

We present new age and mass estimates for 920 stellar clusters in the Large Magellanic Cloud (LMC) based on previously published broadband photometry and the stellar cluster analysis package, MASSCLEANage. Expressed in the generic fitting formula, d 2 N/dMdtvpropM α t β, the distribution of observed clusters is described by α = -1.5 to -1.6 and β = -2.1 to -2.2. For 288 of these clusters, ages have recently been determined based on stellar photometric color-magnitude diagrams, allowing us to gauge the confidence of our ages. The results look very promising, opening up the possibility that this sample of 920 clusters, with reliable and consistent age, mass, and photometric measures, might be used to constrain important characteristics about the stellar cluster population in the LMC. We also investigate a traditional age determination method that uses a χ2 minimization routine to fit observed cluster colors to standard infinite-mass limit simple stellar population models. This reveals serious defects in the derived cluster age distribution using this method. The traditional χ2 minimization method, due to the variation of U, B, V, R colors, will always produce an overdensity of younger and older clusters, with an underdensity of clusters in the log (age/yr) = [7.0, 7.5] range. Finally, we present a unique simulation aimed at illustrating and constraining the fading limit in observed cluster distributions that includes the complex effects of stochastic variations in the observed properties of stellar clusters.

Determining Age and Origin of Spodumene-Bearing Pegmatites in Southeastern Ireland

NASA Astrophysics Data System (ADS)

Brown, A. A.; Barros, R.; Menuge, J. F.

2017-12-01

Exploration prospecting around Caldonian Leinster Granite has revealed pegmatite intrusions containing spodumene, a lithium ore, on the eastern margin of the Tullow Lowlands Pluton. Drill cores of these pegmatites have been extracted and studied due to increasing economic interest. Ages between 430 and 400 Ma for spodumene pegmatites have been previously determined using the in situ Rb-Sr isochron method [1]. Here we use the Sm-Nd isochron method to see if the less-mobile nature of REEs during contact metamorphism and deformation impacts ages. Suitable samples containing garnet and feldspar from spodumene and barren pegmatites were studied using regular microscopy and SEM; minerals were then isolated manually. After mineral dissolution and elemental separation via ion exchange columns, a Neptune MS measured Sm and Nd isotope ratios. Blank corrections were applied. Both types of pegmatites were used to calculate an isochron using Isoplot 3.7 [2] which yielded an initial 143Nd/144Nd ratio of 0.51190±0.00009, and an age of 414±52 Ma. Ages and ɛNd, relating to the initial Nd ratio, were compared with previous whole rock data of Leinster Granite [3] and Rb-Sr multimineral data [1]. Comparable ages from both methods likely represent crystallization age. At the minimum possible age considering uncertainty, the origins of pegmatites and granitic rocks are indistinguishable, but at the maximum age, pegmatites show lower ɛNd values suggesting heterogeneous sources. All representative data points held negative ɛNd values signifying crustal assimilation. The Sm-Nd method was found suitable for age/ source investigation; however, Leinster pegmatite garnet is particularly depleted in Nd (<1 ppm), yielding poor precision, and further study using less depleted samples should be conducted for better age determination. [1] Barros, Renata, Julian F. Menuge and Thomas Zack (2016): "Hints on the Origin and Evolution of Spodumene Pegmatites in Southeast Ireland" Proceedings of the 2nd Eugene E. Foord Pegmatite Symposium, Golden, CO, 9 -13 [2] Ludwig K.R. (2008): Isoplot 3.70, A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center Special Publication, 4 [3] Mohr, Peter (1991): "Cryptic Sr and Nd isotopic variation across the Leinster Granite, Southeast Ireland" Geology Magazine, Vol 128, 3, 251-256

Assessing Articulatory Speed Performance as a Potential Factor of Slowed Speech in Older Adults

ERIC Educational Resources Information Center

Mefferd, Antje S.; Corder, Erin E.

2014-01-01

Purpose: To improve our understanding about the underlying factors of aging-related speaking rate decline, the authors sought to determine if lip and jaw speeds are physiologically constrained in older adults. Method: Thirty-six female--10 young adults (ages 22-27 years), 9 middle-aged adults (ages 45-55 years), 10 young-old adults (65-74 years),…

Successful aging as a multidimensional concept: An integrative review

PubMed Central

Zanjari, Nasibeh; Sharifian Sani, Maryam; Chavoshi, Meimanat Hosseini; Rafiey, Hassan; Mohammadi Shahboulaghi, Farahnaz

2017-01-01

Background: Successful aging as an umbrella term with a large amount of literature has emerged with a variety of meanings and dimensions in different studies. This article aims at determining what dimensions contribute to constructing the concept of successful aging. Methods: The method used in this study is an integrative review of published literature related to successful aging. This method includes both qualitative and quantitative studies. Data searching was conducted during November and December 2014 and was then updated in October 2015. First, 2543 articles were identified, and after the screening phase, 76 articles were eligible for inclusion in the integrative review. Results: The results specified 14 subcategories and 5 main categories of successful aging: social well-being, psychological wellbeing, physical health, spirituality and transcendence, and environment and economic security. Conclusion: The present study provides a thorough understanding of successful aging dimensions and proposes the importance of the multidimensional concept of successful aging at the individual, interpersonal, and environmental levels for future studies and policymaking on population aging.

A spin-down clock for cool stars from observations of a 2.5-billion-year-old cluster.

PubMed

Meibom, Søren; Barnes, Sydney A; Platais, Imants; Gilliland, Ronald L; Latham, David W; Mathieu, Robert D

2015-01-29

The ages of the most common stars--low-mass (cool) stars like the Sun, and smaller--are difficult to derive because traditional dating methods use stellar properties that either change little as the stars age or are hard to measure. The rotation rates of all cool stars decrease substantially with time as the stars steadily lose their angular momenta. If properly calibrated, rotation therefore can act as a reliable determinant of their ages based on the method of gyrochronology. To calibrate gyrochronology, the relationship between rotation period and age must be determined for cool stars of different masses, which is best accomplished with rotation period measurements for stars in clusters with well-known ages. Hitherto, such measurements have been possible only in clusters with ages of less than about one billion years, and gyrochronology ages for older stars have been inferred from model predictions. Here we report rotation period measurements for 30 cool stars in the 2.5-billion-year-old cluster NGC 6819. The periods reveal a well-defined relationship between rotation period and stellar mass at the cluster age, suggesting that ages with a precision of order 10 per cent can be derived for large numbers of cool Galactic field stars.

Device for fluorescent control and photodynamic therapy of age-related macula degeneration

NASA Astrophysics Data System (ADS)

Loschenov, Victor B.; Meerovich, Gennadii A.; Budzinskaya, M. V.; Ermakova, N. A.; Shevchik, S. A.; Kharnas, Sergey S.

2004-07-01

Age-related macula degeneration (AMD) is a wide spread disease the appearance of which leads to poor eyesight and blindness. A method of treatment is not determined until today. Traditional methods, such as laser coagulation and surgical operations are rather traumatic for eye and often bring to complications. That's why recently a photodynamic method of AMD treatment is studied. Based on photodynamic occlusion of choroidal neovascularization (CNV) with minimal injury to overlying neurosensory retina what increases the efficiency.

Age estimation by modified Demirjian's method (2004) and its applicability in Tibetan young adults: A digital panoramic study.

PubMed

Bijjaragi, Shobha C; Sangle, Varsha A; Saraswathi, F K; Patil, Veerendra S; Ashwini Rani, S R; Bapure, Sunil K

2015-01-01

Estimation of the age is a procedure adopted by anthropologists, archeologists and forensic scientists. Different methods have been undertaken. However none of them meet the standards as Demirjian's method since 1973. Various researchers have applied this method, in both original and modified form (Chaillet and Demirjian in 2004) in different ethnic groups and the results obtained were not satisfactory. To determine the applicability and accuracy of modified Demirjian's method of dental age estimation (AE) in 8-18 year old Tibetan young adults to evaluate the interrelationship between dental and chronological age and the reliability between intra- and inter observer relationship. Clinical setting and computerized design. A total of 300 Tibetan young adults with an age range from 8 to 18 years were recruited in the study. Digital panoramic radiographs (DPRs) were evaluated as per the modified Demirjian's method (2004). Pearson correlation, paired t-test, linear regression analysis. Inter -and intraobserver reliability revealed a strong agreement. A positive and strong association was found between chronological age and estimated dental age (r = 0.839) with P < 0.01. Modified Demirjian method (2004) overestimated the age by 0.04 years (2.04 months)in Tibetan young adults. Results suggest that, the modified Demirjian method of AE is not suitable for Tibetan young adults. Further studies: With larger sample size and comparision with different methods of AE in a given population would be an interesting area for future research.

Evaluation of age determination techniques for gray wolves

USGS Publications Warehouse

Landon, D.B.; Waite, C.A.; Peterson, R.O.; Mech, L.D.

1998-01-01

We evaluated tooth wear, cranial suture fusion, closure of the canine pulp cavity, and cementum annuli as methods of age determination for known- and unknown-age gray wolves (Canis lupus) from Alaska, Minnesota, Ontario, and Isle Royale, Michigan. We developed age classes for cranial suture closure and tooth wear. We used measurement data obtained from known-age captive and wild wolves to generate a regression equation to predict age based on the degree of closure of the canine pulp cavity. Cementum annuli were studied in known- and unknown-age animals, and calcified, unstained thin sections were found to provide clear annulus patterns under polarized transmitted light. Annuli counts varied among observers, partly because of variation in the pattern of annuli in different regions of the cementum. This variation emphasizes the need for standardized models of cementum analysis. Cranial suture fusion is of limited utility in age determination, while tooth wear can be used to estimate age of adult wolves within 4 years. Wolves lt 7 years old could be aged to within 13 years with the regression equation for closure of the canine pulp cavity. Although inaccuracy remains a problem, cementum-annulus counts were the most promising means of estimating age for gray wolves.

Age estimation by using dental radiographs

PubMed Central

Limdiwala, Piyush G.; Shah, J. S.

2013-01-01

Background: Estimation of age is important in forensic sciences as a way to establish the identity of human remains. Of the various parts of the body used in age estimation, teeth are the least affected by the taphonomic process. Their durability means that they are sometimes the only body part available for study. Several methods of age estimation have been studied using bone and teeth, and among them, tooth wear and apposition of secondary dentine are the currently available non-destructive methods. Objectives: The purpose of the study was to determine the age of adults by using Kvaal's method as well as to establish the relationship of chronological age and dental age with its reliability and limitations on digital panoramic radiographs. Materials and Methods: The present study was based on panoramic radiographs that consisted of two groups. One hundred orthopantomographs with Kvaal's criteria (Group A) and 50 orthopantomographs without Kvaal's criteria (Group B) were included. Various parameters were measured and the result was analyzed by means of SPSS-12.0 program statistical data. Result and Conclusion: On the basis of Kvaal's criteria, the difference between chronological age and real age was 8.3 years. This suggests that the accuracy of this method depends on the precision of measurements and quality and number of the orthopantomographs. PMID:24255560

Telomere length analysis.

PubMed

Canela, Andrés; Klatt, Peter; Blasco, María A

2007-01-01

Most somatic cells of long-lived species undergo telomere shortening throughout life. Critically short telomeres trigger loss of cell viability in tissues, which has been related to alteration of tissue function and loss of regenerative capabilities in aging and aging-related diseases. Hence, telomere length is an important biomarker for aging and can be used in the prognosis of aging diseases. These facts highlight the importance of developing methods for telomere length determination that can be employed to evaluate telomere length during the human aging process. Telomere length quantification methods have improved greatly in accuracy and sensitivity since the development of the conventional telomeric Southern blot. Here, we describe the different methodologies recently developed for telomere length quantification, as well as their potential applications for human aging studies.

Efficacy of otoliths and first dorsal spines for preliminary age and growth determination in Atlantic Tripletails

USGS Publications Warehouse

Parr, Russell T.; Bringolf, Robert B.; Jennings, Cecil A.

2018-01-01

The Atlantic Tripletail Lobotes surinamensis is a popular sport fish for which age and growth data are scarce in general and nonexistent for Georgia (GA), USA, waters. These data are necessary to ensure that management regulations are adequate to protect this species, especially given its popularity as a sport fish. We evaluated whether otoliths and spines were suitable for determining the estimated age (hereafter, “age”) and growth rates of Atlantic Tripletails, and we ascertained whether one method was more accurate than the other. Atlantic Tripletails were sampled by angling and trawling during March 30–August 10, 2009, and March 14–August 6, 2010, in nearshore GA waters of the Atlantic Ocean. During the study, 243 Atlantic Tripletails were captured and sampled for aging structures. Sagittal otoliths and the first dorsal spine were removed from each fish and used to estimate the age and growth rate. Mean differences in TL at age for spine and otolith data were evaluated with ANOVA. Estimated ages for males and females ranged from 1 to 5 years based on otoliths and spines. Both otolith and spine mean TLs at ages 1 and 2 were significantly different from each other as well as all other age‐classes, whereas mean TLs for ages 3–5 were not significantly different. Differences in Atlantic Tripletail TL among the otolith‐ and spine‐derived age‐classes were not significant. Each method used to age Atlantic Tripletails had advantages and disadvantages. Otoliths had higher initial reader agreement than spines, although agreement between the structures was 84.1%. However, otoliths require sacrifice of the fish, whereas a spine can be taken without sacrificing the fish. The lack of concrete life history data and population estimates suggests that when feasible, nonlethal aging methods would be preferred over lethal methods to ensure the survival of Atlantic Tripletail populations.

MRI of the wrist is not recommended for age determination in female football players of U-16/U-17 competitions.

PubMed

Tscholl, P M; Junge, A; Dvorak, J; Zubler, V

2016-03-01

Age determination on magnetic resonance imaging (MRI) of the wrist is a reliable method in male football players to evaluate their eligibility to participate in Under 17 tournaments. MRI of the wrist was performed in 487 female volunteers aged 13-19 years from Brazil, Germany, Malaysia, and Tanzania, and in 139 female football players participating in Under-16 and Under-17 football tournaments. A previously validated method for grading fusion of the distal radial epiphysis in male adolescent was used. Moderate correlation of chronological age and epiphyseal fusion was found in the normative control group (r = .59) and weak correlation in female football players (r = .27). Complete fusion of the distal radial epiphysis was observed in two 15-year-old volunteers of the control group (1.7%) and in 17.6% (3 of 17) of 14-year-old football players. Up to 10.8% (47 of 437) in the control group and 14.4% (20 of 139) of the football players 17 years or younger had complete fused epiphysis. Because of earlier osseous maturity in female adolescents, the grade of fusion of the distal radial epiphysis on MRI is not recommended for pretournament age determination for the age of 17 and younger in female. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Statistical implications of using moving violations to determine crash responsibility in young driver crashes

PubMed Central

Curry, Allison E.; Pfeiffer, Melissa R.; Myers, Rachel K.; Durbin, Dennis R.; Elliott, Michael R.

2014-01-01

Traditional methods for determining crash responsibility—most commonly moving violation citations—may not accurately characterize at-fault status among crash-involved drivers given that: (1) issuance may vary by factors that are independent of fault (e.g., driver age, gender), and (2) these methods do not capture driver behaviors that are not illegal but still indicative of fault. We examined the statistical implications of using moving violations to determine crash responsibility in young driver crashes by comparing it with a method based on crash-contributing driver actions. We selected all drivers in police-reported passenger-vehicle crashes (2010–2011) that involved a New Jersey driver <21 years old (79,485 drivers < age 21, 61,355 drivers ≥ age 21.) For each driver, crash responsibility was determined from the crash report using two alternative methods: (1) issuance of a moving violation citation; and (2) presence of a driver action (e.g., failure to yield, inattention). Overall, 18% of crash-involved drivers were issued a moving violation while 50% had a driver action. Only 32.2% of drivers with a driver action were cited for a moving violation. Further, the likelihood of being cited given the presence of a driver action was higher among certain driver subgroups—younger drivers, male drivers, and drivers in single-vehicle and more severe crashes. Specifically among young drivers, those driving at night, carrying peer passengers, and having a suspended or no license were more often cited. Conversely, fatally-injured drivers were almost never cited. We also demonstrated that using citation data may lead to statistical bias in the characterization of at-fault drivers and of quasi-induced exposure measures. Studies seeking to accurately determine crash responsibility should thoughtfully consider the potential sources of bias that may result from using legal culpability methods. For many studies, determining driver responsibility via the identification of driver actions may yield more accurate characterizations of at-fault drivers. PMID:24398139

[Present possibilities of age determination in forensic medicine with emphasis on the importance of measurement of D- and L- forms of aspartic acid. I. An overview].

PubMed

Pilin, A; Pudil, F; Gross, R; Herrmannová, M

1997-02-01

Evaluation of age of unknown deceased persons belongs to the most important ways to identification. For the time being, morphological methods are used, namely evaluation of age according to Gustafson's method from tooth grindings or by macroscopical estimation of abrasion, transparency of root dentine, alveolar atrophy and number of missing teeth. Evaluation of the data can be influenced by an individual failure and experience showed an age related decrease of precision. Recently, some papers occurred estimating a relation of D, L-forms of aspartic acid which depends on the age with a significant precision.

Direct simulation of groundwater age

USGS Publications Warehouse

Goode, Daniel J.

1996-01-01

A new method is proposed to simulate groundwater age directly, by use of an advection-dispersion transport equation with a distributed zero-order source of unit (1) strength, corresponding to the rate of aging. The dependent variable in the governing equation is the mean age, a mass-weighted average age. The governing equation is derived from residence-time-distribution concepts for the case of steady flow. For the more general case of transient flow, a transient governing equation for age is derived from mass-conservation principles applied to conceptual “age mass.” The age mass is the product of the water mass and its age, and age mass is assumed to be conserved during mixing. Boundary conditions include zero age mass flux across all noflow and inflow boundaries and no age mass dispersive flux across outflow boundaries. For transient-flow conditions, the initial distribution of age must be known. The solution of the governing transport equation yields the spatial distribution of the mean groundwater age and includes diffusion, dispersion, mixing, and exchange processes that typically are considered only through tracer-specific solute transport simulation. Traditional methods have relied on advective transport to predict point values of groundwater travel time and age. The proposed method retains the simplicity and tracer-independence of advection-only models, but incorporates the effects of dispersion and mixing on volume-averaged age. Example simulations of age in two idealized regional aquifer systems, one homogeneous and the other layered, demonstrate the agreement between the proposed method and traditional particle-tracking approaches and illustrate use of the proposed method to determine the effects of diffusion, dispersion, and mixing on groundwater age.

Speaking Rate Characteristics of Elementary-School-Aged Children Who Do and Do Not Stutter

ERIC Educational Resources Information Center

Logan, Kenneth J.; Byrd, Courtney T.; Mazzocchi, Elizabeth M.; Gillam, Ronald B.

2011-01-01

Purpose: To compare articulation and speech rates of school-aged children who do and do not stutter across sentence priming, structured conversation, and narration tasks and to determine factors that predict children's speech and articulation rates. Method: 34 children who stutter (CWS) and 34 age- and gender-matched children who do not stutter…

The Effect of Science Activities on Concept Acquisition of Age 5-6 Children Groups

ERIC Educational Resources Information Center

Dogru, Mustafa; Seker, Fatih

2012-01-01

Present research aims to determine the effect of science activities on concept development of preschool period age 5-6 children groups. Parallel to research objective, qualitative research pattern has been the selected method. Study group comprises of collectively 48 children from 5-6 age group attending to a private education institution in city…

Precision and accuracy of commonly used dental age estimation charts for the New Zealand population.

PubMed

Baylis, Stephanie; Bassed, Richard

2017-08-01

Little research has been undertaken for the New Zealand population in the field of dental age estimation. This research to date indicates there are differences in dental developmental rates between the New Zealand population and other global population groups, and within the New Zealand population itself. Dental age estimation methods range from dental development charts to complex biometric analysis. Dental development charts are not the most accurate method of dental age estimation, but are time saving in their use. They are an excellent screening tool, particularly for post-mortem identification purposes, and for assessing variation from population norms in living individuals. The aim of this study was to test the precision and accuracy of three dental development charts (Schour and Massler, Blenkin and Taylor, and the London Atlas), used to estimate dental age of a sample of New Zealand juveniles between the ages of 5 and 18 years old (n=875). Percentage 'best fit' to correct age category and to expected chart stage were calculated to determine which chart was the most precise for the sample. Chronological ages were compared to estimated dental ages using a two-tailed paired t-test (P<0.05) for each of the three methods. The mean differences between CA and DA were calculated to determine bias and the absolute mean differences were calculated to indicate accuracy. The results of this study show that while accuracy and precision were low for all charts tested against the New Zealand population sample, the Blenkin and Taylor Australian charts performed best overall. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of thickness of palatal mucosa

PubMed Central

Kolliyavar, Bharati; Setty, Swati; Thakur, Srinath L.

2012-01-01

Background: The palatal masticatory mucosa is widely used as a donor material in periodontal plastic surgery. The thickness of graft tissue is an important factor for the graft survival. The purpose of this study was to determine the thickness of palatal mucosa by a bone sounding technique. The association of age and gender with the thickness of palatal mucosa was also examined. Materials and Methods: Twenty four healthy subjects had participated in the study. The younger age group of 16-30 years consisted of 12 subjects of 7 females and 5 males, and the older age group of 31-54 years consisted of 12 subjects, of 5 females and 7 males. A bone sounding method using a periodontal probe was done to assess the thickness of palatal mucosa at 15 measurement sites defined according to the gingival margin and palatal line. Mann-Whitney test was used to determine the difference in mucosal thickness between both the groups. Results: The younger age group had thinner mucosa ranged from 2 to 3.1 mm in thickness than the older age group which ranged from 3.2 to 3.7 mm. In the same age group, females had thinner mucosa than males in the same age group. The mean thickness of palatal masticatory mucosa ranged from 2.5 to 3.7 mm. Conclusion: The younger subjects had thinner mucosa than older subjects. The canine and premolar areas appeared to be the most appropriate donor site for grafting procedures. PMID:22628968

Testing Backwards Integration As A Method Of Age-Determination for KBO Families

NASA Astrophysics Data System (ADS)

Benfell, Nathan; Ragozzine, Darin

2017-10-01

The age of young asteroid collisional families is often determined by using backwards n-body integration of the solar system. This method is not used for discovering young asteroid families and is limited by the unpredictable influence of the Yarkovsky effect on individual specific asteroids over time. Since these limitations are not as important for objects in the Kuiper belt Marcus et al. 2011 suggested that backwards integration could be used to discover and characterize collisional families in the outer solar system. However, there are some minor effects that may be important to include in the integration to ensure a faithful reproduction of the actual solar system. We have created simulated families of Kuiper Belt objects through a forwards integration of various objects with identical starting locations and velocity distributions, based on the Haumea family. After carrying this integration forwards through ~4 Gyr, backwards integrations are used (1) to investigate which factors are of enough significance to require inclusion in the integration (e.g., terrestrial planets, KBO self-gravity, putative Planet 9, etc.), (2) to test orbital element clustering statistics and identify methods for assessing false alarm probabilities, and (3) to compare the age estimates with the known age of the simulated family to explore the viability of backwards integration for precise age estimates.

Determination of timescales of nitrate contamination by groundwater age models in a complex aquifer system

NASA Astrophysics Data System (ADS)

Koh, E. H.; Lee, E.; Kaown, D.; Lee, K. K.; Green, C. T.

2017-12-01

Timing and magnitudes of nitrate contamination are determined by various factors like contaminant loading, recharge characteristics and geologic system. Information of an elapsed time since recharged water traveling to a certain outlet location, which is defined as groundwater age, can provide indirect interpretation related to the hydrologic characteristics of the aquifer system. There are three major methods (apparent ages, lumped parameter model, and numerical model) to date groundwater ages, which differently characterize groundwater mixing resulted by various groundwater flow pathways in a heterogeneous aquifer system. Therefore, in this study, we compared the three age models in a complex aquifer system by using observed age tracer data and reconstructed history of nitrate contamination by long-term source loading. The 3H-3He and CFC-12 apparent ages, which did not consider the groundwater mixing, estimated the most delayed response time and a highest period of the nitrate loading had not reached yet. However, the lumped parameter model could generate more recent loading response than the apparent ages and the peak loading period influenced the water quality. The numerical model could delineate various groundwater mixing components and its different impacts on nitrate dynamics in the complex aquifer system. The different age estimation methods lead to variations in the estimated contaminant loading history, in which the discrepancy in the age estimation was dominantly observed in the complex aquifer system.

Bone age in children with obstetrical brachial plexus palsy: effect of peripheral nerve injury on skeletal maturation.

PubMed

Oktay, Fügen; Cömert, Didem; Gökkaya, Nilüfer Kutay Ordu; Ozbudak, Sibel Demir; Uysal, Hilmi

2014-02-01

The purpose of this retrospective study was to analyze the effect of peripheral nerve injury on the skeletal maturation process. The bone ages of the affected and unaffected hand-wrists of 42 children with obstetrical brachial palsy were determined according to the Greulich and Pyle atlas. In 23 patients, the bone ages of the both sides were identical (bone-age-symmetrical group), in 19 patients the bone age of the affected side was delayed (bone-age-delayed group). The mean bone age of the affected side was delayed 0.48 ± 0.25 years that of the unaffected side (P = .000), and the delay of bone age was inversely correlated with chronological age (R (2) = .45, P < .02) in the bone-age-delayed group. Skeletal retardation can be recognized after appearance of ossification centers by plain radiography, dating from the third month of life, in early infancy. Thus, bone age determination method might be helpful for predicting potential future limb shortness.

Prevalence of smoking and BMI differences between smokers and non-smokers among children and adolescents aged 7-18 years in south-east Poland.

PubMed

Wandycz, Artur; Jankowiak, Łukasz; Jerzak, Izabela

2018-05-01

Objectives : The aim of the study was to determine the prevalence of smoking among children and adolescents aged 7-18 years, and also to determine the relationship between this addiction and the Body Mass Index (BMI). Methods : Basic anthropometric measurements were performed, and information concerning cigarette smoking and basic SES was gathered using the questionnaire method. Results : More than 5% of boys admit to smoking at the age of 10-11 years, and as many as 22% 18-year-olds admit to doing so. With regard to girls, the situation is slightly better because it is only among 14-year-olds that the percentage of smokers exceeds 5%. Smoking may affect average BMIs. Smoking had a negative impact on the magnitude of physical development indices among children between 8 and 12 years old. Conclusions : The percentage of smokers increases with age. Boys smoke more often than girls. Tobacco smoking in middle childhood (8-12 years) is associated with lower BMIs.

Estimation model of life insurance claims risk for cancer patients by using Bayesian method

NASA Astrophysics Data System (ADS)

Sukono; Suyudi, M.; Islamiyati, F.; Supian, S.

2017-01-01

This paper discussed the estimation model of the risk of life insurance claims for cancer patients using Bayesian method. To estimate the risk of the claim, the insurance participant data is grouped into two: the number of policies issued and the number of claims incurred. Model estimation is done using a Bayesian approach method. Further, the estimator model was used to estimate the risk value of life insurance claims each age group for each sex. The estimation results indicate that a large risk premium for insured males aged less than 30 years is 0.85; for ages 30 to 40 years is 3:58; for ages 41 to 50 years is 1.71; for ages 51 to 60 years is 2.96; and for those aged over 60 years is 7.82. Meanwhile, for insured women aged less than 30 years was 0:56; for ages 30 to 40 years is 3:21; for ages 41 to 50 years is 0.65; for ages 51 to 60 years is 3:12; and for those aged over 60 years is 9.99. This study is useful in determining the risk premium in homogeneous groups based on gender and age.

Comparison of optical and electrical investigations of meat ageing

NASA Astrophysics Data System (ADS)

Prokopyeva, Elena; Tománek, Pavel; Kocová, Lucie; Palai-Dany, Tomáš; Balík, Zdeněk.; Škarvada, Pavel; Grmela, Lubomír.

2013-05-01

Different ultrasonic, electromagnetic, electrical and optical methods are used for meat ageing detection. Muscles are turbid anisotropic media, they exhibit changes in electrical and optical properties according to the direction of the electrical and optical fields in the sample. The work assesses the feasibility of impedance measurements for meat ageing detection and their comparison with optical measurement of scattered light. The pork chop slices were used for their relative homogeneity. An investigation was carried out for the detection of the ageing of unpacked slices exposed directly to the air, and other packed in polyethylene bags. The electrical method is a promising method due to the possibility of getting much information and realizing cheap and fast enough measurement systems. The optical method allows measure the rotation of polarization plane in the range of 95 degrees within considered period. Nevertheless, further work has to be provided to determine closer relationships between optical scattering characteristics, electrical anisotropy in ageing-related tissue structural properties.

Executive Functioning Skills in Preschool-Age Children with Cochlear Implants

ERIC Educational Resources Information Center

Beer, Jessica; Kronenberger, William G.; Castellanos, Irina; Colson, Bethany G.; Henning, Shirley C.; Pisoni, David B.

2014-01-01

Purpose: The purpose of this study was to determine whether deficits in executive functioning (EF) in children with cochlear implants (CIs) emerge as early as the preschool years. Method: Two groups of children ages 3 to 6 years participated in this cross-sectional study: 24 preschoolers who had CIs prior to 36 months of age and 21 preschoolers…

Dating ivory by determination of 14C, 90Sr and 228/232Th.

PubMed

Schmied, Stefanie A K; Brunnermeier, Matthias J; Schupfner, Robert; Wolfbeis, Otto S

2012-09-10

A method is described to determine the time of death of elephants. This is accomplished by analysis of the radionuclides 14C, 90Sr and 228/232Th in known samples of ivory, and in samples of unknown age. The reliability of this method is considerably increased by multi nuclide analysis. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Evaluation of three paediatric weight estimation methods in Singapore.

PubMed

Loo, Pei Ying; Chong, Shu-Ling; Lek, Ngee; Bautista, Dianne; Ng, Kee Chong

2013-04-01

Rapid paediatric weight estimation methods in the emergency setting have not been evaluated for South East Asian children. This study aims to assess the accuracy and precision of three such methods in Singapore children: Broselow-Luten (BL) tape, Advanced Paediatric Life Support (APLS) (estimated weight (kg) = 2 (age + 4)) and Luscombe (estimated weight (kg) = 3 (age) + 7) formulae. We recruited 875 patients aged 1-10 years in a Paediatric Emergency Department in Singapore over a 2-month period. For each patient, true weight and height were determined. True height was cross-referenced to the BL tape markings and used to derive estimated weight (virtual BL tape method), while patient's round-down age (in years) was used to derive estimated weights using APLS and Luscombe formulae, respectively. The percentage difference between the true and estimated weights was calculated. For each method, the bias and extent of agreement were quantified using Bland-Altman method (mean percentage difference (MPD) and 95% limits of agreement (LOA)). The proportion of weight estimates within 10% of true weight (p₁₀) was determined. The BL tape method marginally underestimated weights (MPD +0.6%; 95% LOA -26.8% to +28.1%; p₁₀ 58.9%). The APLS formula underestimated weights (MPD +7.6%; 95% LOA -26.5% to +41.7%; p₁₀ 45.7%). The Luscombe formula overestimated weights (MPD -7.4%; 95% LOA -51.0% to +36.2%; p₁₀ 37.7%). Of the three methods we evaluated, the BL tape method provided the most accurate and precise weight estimation for Singapore children. The APLS and Luscombe formulae underestimated and overestimated the children's weights, respectively, and were considerably less precise. © 2013 The Authors. Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Use of cervical vertebral maturation to determine skeletal age.

PubMed

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

2009-10-01

The purpose of this study was to evaluate the validity of the cervical vertebral maturation (CVM) method as an indicator of skeletal age in the circumpubertal period by correlating it to the hand-wrist method (HWM). Hand-wrist and lateral cephalometric radiographs of 400 Chinese subjects were randomly selected. Their ages were 10 to 15 years for girls and 12 to 17 years for boys, so they were within the circumpubertal period. Skeletal ages were assessed according to the CVM method and the HWM. The CVM was significantly correlated with HWM skeletal age (Spearman r = 0.9521 [boys] and 0.9408 [girls]). All patients in cervical vertebral stage 3 of the CVM corresponded to stages MP3-FG or MP3-G (around the peak of the growth spurt) in the HWM. The CVM is a valid indicator of skeletal growth during the circumpubertal period, providing information for timing of growth modification.

Characterization of the evolution of the volume fraction of precipitates in aged AlMgSiCu alloys using DSC technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esmaeili, Shahrzad; Lloyd, David J.

2005-11-15

Differential scanning calorimetry is used to quantify the evolution of the volume fraction of precipitates during age hardening in AlMgSiCu alloys. The calorimetry tests are run on alloy samples after aging for various times at 180 deg. C and the change in the collective heat effects from the major precipitation and dissolution processes in each run are used to determine the precipitation state of the samples. The method is implemented on alloys with various thermal histories prior to artificial aging, including commercial pre-aging histories. The estimated values for the relative volume fraction of precipitates are compared with the results frommore » a newly developed analytical method using isothermal calorimetry and a related quantitative transmission electron microscopy work. Excellent agreement is obtained between the results from various methods.« less

Forest management and economics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buongiorno, J.; Gilless, J.K.

1987-01-01

This volume provides a survey of quantitative methods, guiding the reader through formulation and analysis of models that address forest management problems. The authors use simple mathematics, graphics, and short computer programs to explain each method. Emphasizing applications, they discuss linear, integer, dynamic, and goal programming; simulation; network modeling; and econometrics, as these relate to problems of determining economic harvest schedules in even-aged and uneven-aged forests, the evaluation of forest policies, multiple-objective decision making, and more.

Determination of Selected Amino Acids in Serum of Patients with Liver Disease.

PubMed

Kanďár, Roman; Drábková, Petra; Toiflová, Tereza; Čegan, Alexander

2016-01-01

The determination of amino acids can be a reliable approach for extended diagnosis of liver diseases. This is because liver disease can be a cause of impaired amino acid metabolism. Therefore, a method for the determination of serum amino acids, applicable for clinical purposes, is necessary. The aim of this study was to find differences in the levels of selected amino acids between patients with liver disease and a control group. Samples of peripheral venous blood were obtained from a group of patients with liver disease (n = 131, 59 women at an average age of 60 years and 72 men at an average age of 52 years) and a control group (n = 105, 47 women at an average age of 62 years and 58 men at an average age of 58 years). Before the separation, the amino acids were derivatized with naphthalene-2,3-dicarboxaldehyde. For the separation, reverse phase column was used. The effluent was monitored with a fluorescence detector. There were significant differences in the concentrations of some amino acids between the patients and the control group, but also between women and men. Correlations between some amino acids and markers of liver blood tests and lipid metabolism were observed. A simple, relatively rapid and selective HPLC method with fluorescence detection for the determination of selected amino acids in serum has been developed.

Effect of Aging Process and Time on Physicochemical and Sensory Evaluation of Raw Beef Top Round and Shank Muscles Using an Electronic Tongue.

PubMed

Kim, Ji-Han; Kim, Dong-Han; Ji, Da-Som; Lee, Hyun-Jin; Yoon, Dong-Kyu; Lee, Chi-Ho

2017-01-01

The objective of this study was to determine the effect of aging method (dry or wet) and time (20 d or 40 d) on physical, chemical, and sensory properties of two different muscles (top round and shank) from steers (n=12) using an electronic tongue (ET). Moisture content was not affected by muscle types and aging method ( p >0.05). Shear force of dry aged beef was significantly decreased compared to that of wet aged beef. Most fatty acids of dry aged beef were significantly lower than those of wet aged beef. Dry aged shank muscles had more abundant free amino acids than top round muscles. Dry-aging process enhanced tastes such as umami and saltiness compared to wet-aging process according to ET results. Dry-aging process could enhance the instrumental tenderness and umami taste of beef. In addition, the taste of shank muscle was more affected by dry-aging process than that of round muscle.

Effect of Aging Process and Time on Physicochemical and Sensory Evaluation of Raw Beef Top Round and Shank Muscles Using an Electronic Tongue

PubMed Central

2017-01-01

The objective of this study was to determine the effect of aging method (dry or wet) and time (20 d or 40 d) on physical, chemical, and sensory properties of two different muscles (top round and shank) from steers (n=12) using an electronic tongue (ET). Moisture content was not affected by muscle types and aging method (p>0.05). Shear force of dry aged beef was significantly decreased compared to that of wet aged beef. Most fatty acids of dry aged beef were significantly lower than those of wet aged beef. Dry aged shank muscles had more abundant free amino acids than top round muscles. Dry-aging process enhanced tastes such as umami and saltiness compared to wet-aging process according to ET results. Dry-aging process could enhance the instrumental tenderness and umami taste of beef. In addition, the taste of shank muscle was more affected by dry-aging process than that of round muscle. PMID:29725203

Changes in spinal mobility with increasing age in women.

PubMed

Einkauf, D K; Gohdes, M L; Jensen, G M; Jewell, M J

1987-03-01

The purpose of our study was to determine changes in spinal mobility for women aged 20 to 84 years. Anterior flexion, right and left lateral flexion, and extension were measured on 109 healthy women. The modified Schober method was used to measure anterior flexion. Standard goniometry was used to measure lateral flexion and extension. The results of the study indicated that spinal mobility decreases with advancing age. The most significant (p less than .05) differences occurred between the two youngest and the two oldest age categories. Data gathered in this study indicate that physical therapists should consider the effects of age on spinal mobility when assessing spinal range of motion. A simple, objective method for measuring spinal mobility is presented. Suggestions for future research are given.

Simultaneous measurement of NAD metabolome in aged mice tissue using liquid chromatography tandem-mass spectrometry.

PubMed

Yaku, Keisuke; Okabe, Keisuke; Nakagawa, Takashi

2018-06-01

Nicotinamide adenine dinucleotide (NAD) is a major co-factor that mediates multiple biological processes including redox reaction and gene expression. Recently, NAD metabolism has received considerable attention because administration of NAD precursors exhibited beneficial effects against aging-related metabolic disorders in animals. Although numerous studies have reported that NAD levels decline with aging in multiple animal tissues, the pathway and kinetics of NAD metabolism in aged organs are not completely understood. To determine the NAD metabolism upon aging, we developed targeted metabolomics based on an LC/MS/MS system. Our method is simple and applicable to crude biological samples, including culture cells and animal tissues. Unlike a conventional enzymatic cycling assay, our approach can determine NAD and NADH (reduced form of NAD) by performing a single sample preparation. Further, we validated our method using biological samples and investigated the alteration of the NAD metabolome during aging. Consistent with previous reports, the NAD levels in the liver and skeletal muscle decreased with aging. Further, we detected a significant increase in nicotinamide mononucleotide and nicotinamide riboside in the kidney upon aging. The LC/MS/MS-based NAD metabolomics that we have developed is extensively applicable to biomedical studies, and the results will present innovative ideas for the aging studies, especially for that of NAD metabolism. Copyright © 2018 John Wiley & Sons, Ltd.

Refining aging criteria for northern sea otters in Washington State

USGS Publications Warehouse

Schuler, Krysten L.; Baker, Bridget B.; Mayer, Karl A.; Perez-Heydrich, Carolina; Holahan, Paula M.; Thomas, Nancy J.; White, C. LeAnn

2018-01-01

Measurement of skull ossification patterns is a standard method for aging various mammalian species and has been used to age Russian, Californian, and Alaskan sea otter populations. Cementum annuli counts have also been verified as an accurate aging method for the Alaskan sea otter population. In this study, cementum annuli count results and skull ossification patterns were compared as methods for aging the northern sea otter (Enhydra lutris kenyoni) population in Washington State. Significant agreement was found between the two methods suggesting that either method could be used to age the Washington population of otters. This study also found that ossification of the squamosal-jugal suture at the ventral glenoid fossa can be used to differentiate male subadults from adults. To assist field biologists or others without access to cementum annuli or skull ossification analysis techniques, a suite of morphologic, physiologic, and developmental characteristics were analyzed to assess whether a set of these more easily accessible parameters could also predict age class for the Washington population of otters. Tooth condition score, evidence of reproductive activity in females, and tooth eruption pattern were identified as the most useful criteria for classifying Washington sea otters as pups, juveniles, subadults, or adults/aged adults. A simple decision tree based on characteristics accessible in the field or at necropsy was created that can be used to reliably predict age class of Washington sea otters as determined by cementum annuli.

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

PubMed

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

2006-11-01

The aims of this study were (1) to investigate the relationship between chronologic age and maturation of cervical vertebrae, (2) to identify the relationship between chronologic age and maturation stage evaluated by hand-wrist radiographs, and (3) to determine whether the maturation of cervical vertebrae correlates with maturation indicated by hand-wrist radiographs in a Turkish population. The samples were derived from lateral cephalometric and hand-wrist radiographs of 503 subjects (213 male, 290 female; ages, 5.3-24.1 years). Cervical vertebral development was evaluated by the method of Hassel and Farman. Skeletal maturation of each hand-wrist radiograph was determined according to the method described by Björk and Grave, and Brown's system. The Spearman rank-order correlation coefficients were estimated separately for males and females to measure the relationships among chronologic age, cervical vertebral maturation, and the skeletal maturation measured at the hand-wrist. The Spearman correlation coefficients were 0.72 (P <.001) between chronologic age and cervical vertebrae skeletal maturation, and 0.79 (P < .001) between chronologic age and maturation via hand-wrist radiographs. The correlation coefficient between hand-wrist and cervical-vertebrae maturation was 0.86 (P <.001). The cervical-vertebrae maturation stages are clinically useful maturity indicators of the pubertal growth period Turkish subjects.

Sex determination of human remains from peptides in tooth enamel.

PubMed

Stewart, Nicolas Andre; Gerlach, Raquel Fernanda; Gowland, Rebecca L; Gron, Kurt J; Montgomery, Janet

2017-12-26

The assignment of biological sex to archaeological human skeletons is a fundamental requirement for the reconstruction of the human past. It is conventionally and routinely performed on adults using metric analysis and morphological traits arising from postpubertal sexual dimorphism. A maximum accuracy of ∼95% is possible if both the cranium and os coxae are present and intact, but this is seldom achievable for all skeletons. Furthermore, for infants and juveniles, there are no reliable morphological methods for sex determination without resorting to DNA analysis, which requires good DNA survival and is time-consuming. Consequently, sex determination of juvenile remains is rarely undertaken, and a dependable and expedient method that can correctly assign biological sex to human remains of any age is highly desirable. Here we present a method for sex determination of human remains by means of a minimally destructive surface acid etching of tooth enamel and subsequent identification of sex chromosome-linked isoforms of amelogenin, an enamel-forming protein, by nanoflow liquid chromatography mass spectrometry. Tooth enamel is the hardest tissue in the human body and survives burial exceptionally well, even when the rest of the skeleton or DNA in the organic fraction has decayed. Our method can reliably determine the biological sex of humans of any age using a body tissue that is difficult to cross-contaminate and is most likely to survive. The application of this method will make sex determination of adults and, for the first time, juveniles a reliable and routine activity in future bioarcheological and medico-legal science contexts. Copyright © 2017 the Author(s). Published by PNAS.

Skeletal and chronological ages in American adolescents: current findings in skeletal maturation.

PubMed

Calfee, Ryan P; Sutter, Melanie; Steffen, Jennifer A; Goldfarb, Charles A

2010-10-01

This study was designed to assess the relationship between skeletal and chronological ages among current American adolescents using the Greulich and Pyle atlas for skeletal age determination. We used the Greulich and Pyle atlas to prospectively determine skeletal age in a group of 138 otherwise healthy American adolescents from 12 to 18 years of age. 62 males and 76 females were enrolled in this cohort. Paired Student t-tests were used to statistically compare the skeletal and chronological ages in this population. Subgroup analysis examined the effect of gender on differences between chronologic age and skeletal age. For the entire cohort, mean skeletal age was significantly greater than chronological age (mean 0.80 years, P < 0.01). In 29 cases (21%) the skeletal age was at least 2 years greater than the chronologic age. Among females, such cases with marked discrepancy occurred exclusively in those chronologically between 12 and 15 years of age (P < 0.01). Males demonstrated a 2-year or greater discrepancy more commonly than females (26 vs. 17%). In males, 2-year discrepancies were equally likely across chronologic ages (P = 0.82). Current American adolescents are significantly more mature by skeletal age, as determined by the Greulich and Pyle method, than their chronological age would suggest. The skeletal ages of females are most likely to markedly exceed chronologic age between the ages of 12-15 years.

Kontekst stratygraficzny zastosowania różnych odmian metody termoluminescencyjnej w datowaniu lessów z terenu Polski południowo-wschodniej i Ukrainy północno-zachodniej

NASA Astrophysics Data System (ADS)

Kusiak, Jarosław

2008-01-01

Loess profiles contain a complex but usually incomplete sequence of deposits. In order to chronologically organize deposit layers accessible in different exposures it is necessary to use absolute dating methods. The 14C, TL and OSL methods are widely used for dating of the Upper Pleistocene deposits whereas to older Pleistocene deposits only luminescence methods are applied. Some attempts are made to use the OSL method for dating of the deposits older than the Upper Pleistocene. However, the OSL ages seem to be consistently lower than the TL ages, and also considerably underestimated with reference to stratigraphic interpretation. This fact indicates that the TL method should be used above all. The possibility of TL dating of loesses is connected with their aeolian origin. The obtained TL age should correspond to geological time when mineral grains constituting deposit were exposed to sunlight before deposition. Such exactly condition is met in case of loess deposits. There are many variants of thermoluminescence method because different measuring procedures can be used. Depending on the used procedure, the TL ages obtained for the same sample can be considerably different. The manner of equivalent dose determination is decisive for the obtained TL ages. The factors influencing the value of equivalent dose are presented in this paper. The equivalent dose is determined by comparison of thermoluminescence measured for a given sample with thermoluminescence of the same sample after irradiation in laboratory with known doses of ionizing radiation. The following criteria should be taken into account: size of mineral grains, relation between thermoluminescence and heating temperature, way of reduction of unstable thermoluminescence, and the results of plateau test. The variant of thermoluminescence method used in the TL Laboratory of the Department of Physical Geography and Palaeogeography, Maria Curie-Skłodowska University in Lublin is as follows. The dose rate is determined by gamma spectrometry. The equivalent dose is determined by the total-bleach technique for the 45-63 μm fraction. Blue light obtained using the BG-28 filter is applied. Samples are preheated at 160°C for 3 hours before measurement. Light sum is read as the maximum height of glow curve. The application of such measurement procedure allows reliable dating of climatic episodes recorded in loess deposits not only related to the last glacial but also in older ones.

Qualitative-Geospatial Methods of Exploring Person-Place Transactions in Aging Adults: A Scoping Review.

PubMed

Hand, Carri; Huot, Suzanne; Laliberte Rudman, Debbie; Wijekoon, Sachindri

2017-06-01

Research exploring how places shape and interact with the lives of aging adults must be grounded in the places where aging adults live and participate. Combined participatory geospatial and qualitative methods have the potential to illuminate the complex processes enacted between person and place to create much-needed knowledge in this area. The purpose of this scoping review was to identify methods that can be used to study person-place relationships among aging adults and their neighborhoods by determining the extent and nature of research with aging adults that combines qualitative methods with participatory geospatial methods. A systematic search of nine databases identified 1,965 articles published from 1995 to late 2015. We extracted data and assessed whether the geospatial and qualitative methods were supported by a specified methodology, the methods of data analysis, and the extent of integration of geospatial and qualitative methods. Fifteen studies were included and used the photovoice method, global positioning system tracking plus interview, or go-along interviews. Most included articles provided sufficient detail about data collection methods, yet limited detail about methodologies supporting the study designs and/or data analysis. Approaches that combine participatory geospatial and qualitative methods are beginning to emerge in the aging literature. By more explicitly grounding studies in a methodology, better integrating different types of data during analysis, and reflecting on methods as they are applied, these methods can be further developed and utilized to provide crucial place-based knowledge that can support aging adults' health, well-being, engagement, and participation. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

PubMed

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

2015-01-01

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

Terrestrial Ages of Antarctic Meteorites- Update 1999

NASA Technical Reports Server (NTRS)

Nishiizumi, Kunihiko; Welten, K. C.; Caffee, Marc W.

1999-01-01

We are continuing our ongoing study of cosmogenic nuclides in Antarctic meteorites. In addition to the studies of exposure histories of meteorites, we study terrestrial ages and pairing of Antarctic meteorites and desert meteorites. Terrestrial ages of Antarctic meteorites provide information on meteorite accumulation mechanisms, mean weathering lifetimes, and influx rates. The determination of Cl-36(half-life=3.01 x 10(exp 5) y) terrestrial ages is one of our long-term on-going projects, however, in many instances neither Cl-36 or C-14 (5,730 y) yields an accurate terrestrial age. Using Ca-14 (1.04 x 10(exp 5) y) for terrestrial age determinations solves this problem by filling the c,ap in half-life between 14-C and Cl-36 ages. We are now applying the new Ca-41- Cl-36 terrestrial age method as well as the Cl-36-Be-10 method to Antarctic meteorites. Our measurements and C-14 terrestrial age determinations by the University of Arizona group are always complementary. We have measured Cl-36 in over 270 Antarctic meteorites since our previous compilation of terrestrial ages. Since a large number of meteorites have been recovered from many different icefields in Antarctica, we continue to survey the trends of terrestrial ages for different icefields. We have also measured detailed terrestrial ages vs. sample locations for Allan Hills, Elephant Moraine, and Lewis Cliff Icefields, where meteorites have been found with very long ages. The updated histograms of terrestrial ages of meteorites from the Allan Hills Main Icefield and Lewis Cliff Icefield are shown. These figures include C-14 ages obtained by the University of Arizona group. Pairs of meteorites are shown as one object for which the age is the average of all members of the same fall. The width of the bars represents 70,000 years, which was a typical uncertainty for Cl-36 ages. We reduced the uncertainty of terrestrial age determinations to approx. 40,000 years by using pairs of nuclides such as Ca-41-Cl-36 or Cl-36-Be-10. Meteorites found at the Allan Hills Icefields are much older than any other meteorites. The terrestrial ages cover a wide range and are as old as 2 My. Many of the Lewis Cliff meteorites are as old as the Allan Hills meteorites. So far, no clear correlation has been found between the terrestrial ages and the locations of the Lewis Cliff meteorites.

A Novel Method for Age Estimation in Solar-Type Stars Through GALEX FUV Magnitudes

NASA Astrophysics Data System (ADS)

Ho, Kelly; Subramonian, Arjun; Smith, Graeme; Shouru Shieh

2018-01-01

Utilizing an inverse association known to exist between Galaxy Evolution Explorer (GALEX) far ultraviolet (FUV) magnitudes and the chromospheric activity of F, G, and K dwarfs, we explored a method of age estimation in solar-type stars through GALEX FUV magnitudes. Sample solar-type star data were collected from refereed publications and filtered by B-V and absolute visual magnitude to ensure similarities in temperature and luminosity to the Sun. We determined FUV-B and calculated a residual index Q for all the stars, using the temperature-induced upper bound on FUV-B as the fiducial. Plotting current age estimates for the stars against Q, we discovered a strong and significant association between the variables. By applying a log-linear transformation to the data to produce a strong correlation between Q and loge Age, we confirmed the association between Q and age to be exponential. Thus, least-squares regression was used to generate an exponential model relating Q to age in solar-type stars, which can be used by astronomers. The Q-method of stellar age estimation is simple and more efficient than existing spectroscopic methods and has applications to galactic archaeology and stellar chemical composition analysis.

Speleothem dating using Sulfur to Calcium ratio

NASA Astrophysics Data System (ADS)

Sabri, Raghid

2017-04-01

A speleothem sample from underground water tunnel in Nablus, Palestine, showed contamination from wastewater. The young sample has low concentration of Uranium and could not be dated with uranium thorium dating method. An alternative method was used to determine the age of the sample: lamina counting coupled with Sulfur to calcium ratio peaks counting. Sulfur and Calcium concentrations were measured using SEM-EDS to have a better resolution than the CNS analyzer. Assuming seasonal growth of laminations, it was possible to determine the primarily ages. The sinter was still growing during sampling in 2011. The counting reveals 271 laminae, for seasonal growth it means 135 years. In the 1959, it was observed that there is an unexpected peak of Sulfur to calcium ratio and this peak was repeated seasonally. The sulfur peak increased as a result of diesel use in the heating system during the winter season. For the youngest 117 laminae, 59 S/Ca peaks are observed. Each two lamination layers correspond to one peak. So, it was possible to determine the age of the sample using Sulfur to Calcium ratio.

Age determination of unaccompanied asylum seeking minors in the European Union: a health law perspective.

PubMed

Abbing, Henriette D C Roscam

2011-01-01

In the European Union, unaccompanied asylum seekers below 18 years of age are entitled to specific treatment. Age assessment practices to verify the age-statement by the asylum seeker differ between EU Member States. Medical methods in use raise questions about accuracy, reliability and safety. The medical, legal and ethical acceptability of invasive methods (notably X-rays) in particular is controversial. Human rights are at stake. The lack of common practices results in different levels of protection (discrimination). The absence ofstandardisation is an obstacle for the functioning of the Common European Asylum System. EU Best Practice Guidelines should remedy the situation; such guidelines should reflect the best interest of the child.

Determining productivity gains from herbaceous vegetation management with 'age-shift' calculations

Treesearch

David B. South; James H. Miller; Mark O. Kimberley; Curtis L. Vanderschaaf

2006-01-01

Gains in stand volume that result from competition control and fertilization are sometimes reported as 'percentage gains'. Because percentage gains arithmetically decline over time asstand volume increases, plantation managers have difficultyin using percentage gains to project growth and revenues. The 'age-shift' method quantifies the year...

Astronomical Distance Determination in the Space Age. Secondary Distance Indicators

NASA Astrophysics Data System (ADS)

Czerny, Bożena; Beaton, Rachael; Bejger, Michał; Cackett, Edward; Dall'Ora, Massimo; Holanda, R. F. L.; Jensen, Joseph B.; Jha, Saurabh W.; Lusso, Elisabeta; Minezaki, Takeo; Risaliti, Guido; Salaris, Maurizio; Toonen, Silvia; Yoshii, Yuzuru

2018-02-01

The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations.

Sediment residence times constrained by uranium-series isotopes: A critical appraisal of the comminution approach

NASA Astrophysics Data System (ADS)

Handley, Heather K.; Turner, Simon; Afonso, Juan C.; Dosseto, Anthony; Cohen, Tim

2013-02-01

Quantifying the rates of landscape evolution in response to climate change is inhibited by the difficulty of dating the formation of continental detrital sediments. We present uranium isotope data for Cooper Creek palaeochannel sediments from the Lake Eyre Basin in semi-arid South Australia in order to attempt to determine the formation ages and hence residence times of the sediments. To calculate the amount of recoil loss of 234U, a key input parameter used in the comminution approach, we use two suggested methods (weighted geometric and surface area measurement with an incorporated fractal correction) and typical assumed input parameter values found in the literature. The calculated recoil loss factors and comminution ages are highly dependent on the method of recoil loss factor determination used and the chosen assumptions. To appraise the ramifications of the assumptions inherent in the comminution age approach and determine individual and combined comminution age uncertainties associated to each variable, Monte Carlo simulations were conducted for a synthetic sediment sample. Using a reasonable associated uncertainty for each input factor and including variations in the source rock and measured (234U/238U) ratios, the total combined uncertainty on comminution age in our simulation (for both methods of recoil loss factor estimation) can amount to ±220-280 ka. The modelling shows that small changes in assumed input values translate into large effects on absolute comminution age. To improve the accuracy of the technique and provide meaningful absolute comminution ages, much tighter constraints are required on the assumptions for input factors such as the fraction of α-recoil lost 234Th and the initial (234U/238U) ratio of the source material. In order to be able to directly compare calculated comminution ages produced by different research groups, the standardisation of pre-treatment procedures, recoil loss factor estimation and assumed input parameter values is required. We suggest a set of input parameter values for such a purpose. Additional considerations for calculating comminution ages of sediments deposited within large, semi-arid drainage basins are discussed.

Evaluating aging in cats: How to determine what is healthy and what is disease.

PubMed

Bellows, Jan; Center, Sharon; Daristotle, Leighann; Estrada, Amara H; Flickinger, Elizabeth A; Horwitz, Debra F; Lascelles, B Duncan X; Lepine, Allan; Perea, Sally; Scherk, Margie; Shoveller, Anna K

2016-07-01

Many of the changes that occur with aging are not considered pathologic and do not negatively affect overall wellness or quality of life. Ruling out disease is essential, however, when attempting to determine whether an aged cat can be considered 'healthy'. A clear understanding of the normal and abnormal changes that are associated with aging in cats can help practitioners make decisions regarding medical management, feeding interventions and additional testing procedures for their aged patients. It can be difficult to determine if a cat is displaying changes that are appropriate for age. For example, healthy aged cats may have hematologic or serum biochemistry changes that differ from those of the general feline population. Assessment of behavioral health and cognitive changes, as well as auditory, olfactory and visual changes, can also be challenging in the aged patient. This is the second of two review articles in a Special Issue devoted to feline healthy aging. The goals of the project culminating in these publications included developing a working definition for healthy aging in feline patients and identifying clinical methods that can be used to accurately classify healthy aged cats. This second review proposes criteria for assessing 'healthy aged cats'. There is a paucity of research in feline aging. The authors draw on expert opinion and available data in both the cat and other species. © The Author(s) 2016.

Excellent amino acid racemization results from Holocene sand dollars

NASA Astrophysics Data System (ADS)

Kosnik, M.; Kaufman, D. S.; Kowalewski, M.; Whitacre, K.

2015-12-01

Amino acid racemization (AAR) is widely used as a cost-effective method to date molluscs in time-averaging and taphonomic studies, but it has not been attempted for echinoderms despite their paleobiological importance. Here we demonstrate the feasibility of AAR geochronology in Holocene aged Peronella peronii (Echinodermata: Echinoidea) collected from Sydney Harbour (Australia). Using standard HPLC methods we determined the extent of AAR in 74 Peronella tests and performed replicate analyses on 18 tests. We sampled multiple areas of two individuals and identified the outer edge as a good sampling location. Multiple replicate analyses from the outer edge of 18 tests spanning the observed range of D/Ls yielded median coefficients of variation < 4% for Asp, Phe, Ala, and Glu D/L values, which overlaps with the analytical precision. Correlations between D/L values across 155 HPLC injections sampled from 74 individuals are also very high (pearson r2 > 0.95) for these four amino acids. The ages of 11 individuals spanning the observed range of D/L values were determined using 14C analyses, and Bayesian model averaging was used to determine the best AAR age model. The averaged age model was mainly composed of time-dependent reaction kinetics models (TDK, 71%) based on phenylalanine (Phe, 94%). Modelled ages ranged from 14 to 5539 yrs, and the median 95% confidence interval for the 74 analysed individuals is ±28% of the modelled age. In comparison, the median 95% confidence interval for the 11 calibrated 14C ages was ±9% of the median age estimate. Overall Peronella yields exceptionally high-quality AAR D/L values and appears to be an excellent substrate for AAR geochronology. This work opens the way for time-averaging and taphonomic studies of echinoderms similar to those in molluscs.

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

PubMed Central

Tuteja, Monica; Bahirwani, Shraddha; Balaji, P

2012-01-01

Objectives: The identity of a person can be established by assessing one's age, and in order to be entitled to civil rights and social benefits, verification of the chronological age is required and thereby age estimation has gained an increasing significance in recent years. Tooth eruption is one of the criteria of developmental morphology that can be evaluated by either clinical examination or by evaluation of dental radiographs to determine the dental age. The present study was aimed to evaluate the reliability of the third molar eruption stage as a parameter for forensic age estimation in living subjects. Materials and Methods: The stage of wisdom tooth eruption in 77 male and 73 female Indian subjects aged between 12–26 years was determined by subjecting them to conventional orthopantomograms and was interpreted to assess the third molar eruption stages to evaluate the dental age. Results: Predicted minimum age and mean age of the study sample were found to be significant predictors (P<0.001) of actual age. Minimum age was able to explain 58.3% of the variation in actual age and the mean age was able to explain 60.3% of variation in actual age. Conclusion: Third molar is fairly a reliable indicator to determine the age of alveolar, gingival, and complete emergence of third molar in the occlusal plane in adolescents and young adults. Minimum and most probable ages of examined subjects can also be evaluated using third molar eruption stage. PMID:23087576

Relationship of tooth wear to chronological age among indigenous Amazon populations.

PubMed

Vieira, Elma Pinto; Barbosa, Mayara Silva; Quintão, Cátia Cardoso Abdo; Normando, David

2015-01-01

In indigenous populations, age can be estimated based on family structure and physical examination. However, the accuracy of such methods is questionable. The aim of this cross-sectional study was to evaluate occlusal tooth wear related to estimated age in the remote indigenous populations of the Xingu River, Amazon. Two hundred and twenty three semi-isolated indigenous subjects with permanent dentition from the Arara (n = 117), Xicrin-Kayapó (n = 60) and Assurini (n = 46) villages were examined. The control group consisted of 40 non-indigenous individuals living in an urban area in the Amazon basin (Belem). A modified tooth wear index was applied and then associated with chronological age by linear regression analysis. A strong association was found between tooth wear and chronological age in the indigenous populations (p <0.001). Tooth wear measurements were able to explain 86% of the variation in the ages of the Arara sample, 70% of the Xicrin-Kaiapó sample and 65% of the Assurini sample. In the urban control sample, only 12% of ages could be determined by tooth wear. These findings suggest that tooth wear is a poor estimator of chronological age in the urban population; however, it has a strong association with age for the more remote indigenous populations. Consequently, these findings suggest that a simple tooth wear evaluation method, as described and applied in this study, can be used to provide a straightforward and efficient means to assist in age determination of newly contacted indigenous groups.

Relationship of Tooth Wear to Chronological Age among Indigenous Amazon Populations

PubMed Central

Vieira, Elma Pinto; Barbosa, Mayara Silva; Quintão, Cátia Cardoso Abdo; Normando, David

2015-01-01

In indigenous populations, age can be estimated based on family structure and physical examination. However, the accuracy of such methods is questionable. The aim of this cross-sectional study was to evaluate occlusal tooth wear related to estimated age in the remote indigenous populations of the Xingu River, Amazon. Two hundred and twenty three semi-isolated indigenous subjects with permanent dentition from the Arara (n = 117), Xicrin-Kayapó (n = 60) and Assurini (n = 46) villages were examined. The control group consisted of 40 non-indigenous individuals living in an urban area in the Amazon basin (Belem). A modified tooth wear index was applied and then associated with chronological age by linear regression analysis. A strong association was found between tooth wear and chronological age in the indigenous populations (p <0.001). Tooth wear measurements were able to explain 86% of the variation in the ages of the Arara sample, 70% of the Xicrin-Kaiapó sample and 65% of the Assurini sample. In the urban control sample, only 12% of ages could be determined by tooth wear. These findings suggest that tooth wear is a poor estimator of chronological age in the urban population; however, it has a strong association with age for the more remote indigenous populations. Consequently, these findings suggest that a simple tooth wear evaluation method, as described and applied in this study, can be used to provide a straightforward and efficient means to assist in age determination of newly contacted indigenous groups. PMID:25602501

CMR Reference Values for Left Ventricular Volumes, Mass and Ejection Fraction Using Computer-Aided Analysis: The Framingham Heart Study

PubMed Central

Chuang, Michael L.; Gona, Philimon; Hautvast, Gilion L.T.F.; Salton, Carol J.; Breeuwer, Marcel; O’Donnell, Christopher J.; Manning, Warren J.

2013-01-01

Purpose To determine sex-specific reference values for left ventricular (LV) volumes, mass and ejection fraction (EF) in healthy adults using computer-aided analysis and to examine the effect of age on LV parameters. Methods and Methods We examined data from 1494 members of the Framingham Heart Study Offspring cohort, obtained using short-axis stack cine SSFP CMR, identified a healthy reference group (without cardiovascular disease, hypertension, or LV wall motion abnormality) and determined sex-specific upper 95th percentile thresholds for LV volumes and mass, and lower 5th percentile thresholds for EF using computer-assisted border detection. In secondary analyses we stratified participants by age-decade and tested for linear trend across age groups. Results The reference group comprised 685 adults (423F; 61±9 years). Men had greater LV volumes and mass, before and after indexation to common measures of body size (all p<0.001). Women had greater EF (73±6 vs. 71±6%, p=0.0002). LV volumes decreased with greater age in both sexes, even after indexation. Indexed LV mass did not vary with age. LV EF and concentricity increased with greater age in both sexes. Conclusion We present CMR-derived LV reference values. There are significant age and sex differences in LV volumes, EF and geometry, while mass differs between sexes but not age groups. PMID:24123369

Airborne SAR determination of relative ages of Walker Valley moraines, eastern Sierra Nevada

NASA Technical Reports Server (NTRS)

Fox, A.; Isacks, B.; Bloom, A.; Fielding, E.; Mcmurry, D.

1991-01-01

A regional study of the distribution and elevations of Pleistocene moraines in the Andes requires a method of determining relative age from space. One of our primary objectives is to establish the relative chronology of major climatic events responsible for glaciation in the Andes and other regions that are difficult to access on the ground and where suitable material for absolute age determination is lacking. The sensitivity of radar to surface roughness makes it possible to develop a remotely-based relative dating technique for landforms for which surface age and roughness can be correlated. We are developing such a technique with Airborne Synthetic Aperture Radar (AIRSAR) imagery of the eastern Sierra Nevada where independent evidence is available for the ages and physical characteristics of moraines. The Sierra Nevada moraines are similar in form and environmental setting to Andean moraines that we have targeted for study during the pending Shuttle Imaging Radar-C (SIR-C) mission. SAR imagery is used to differentiate the ages of five moraine sequences of Walker Valley in the eastern Sierra Nevada. Other aspects of this investigation are briefly discussed.

New Reference Centiles for Left Ventricular Mass Relative to Lean Body Mass in Children.

PubMed

Foster, Bethany J; Khoury, Philip R; Kimball, Thomas R; Mackie, Andrew S; Mitsnefes, Mark

2016-05-01

Echocardiographic measurement of left ventricular (LV) mass is routinely performed in pediatric patients with elevated cardiovascular risk. The complex relationship between heart growth and body growth in children requires normalization of LV mass to determine its appropriateness relative to body size. LV mass is strongly determined by lean body mass (LBM). Using new LBM predictive equations, the investigators generated sex-specific LV mass-for-LBM centile curves for children 5 to 18 years of age. This retrospective study used M-mode echocardiographic data collected from 1995 through 2003 from 939 boys and 771 girls between 5 and 18 years of age (body mass index < 85th percentile for sex and age) to create smoothed sex-specific LV mass-for-LBM reference centile curves using the Lamda Mu Sigma method. The newly developed reference centiles were applied to children with essential hypertension and with chronic kidney disease, groups known to be at high risk for LV hypertrophy (LVH). The identification of LVH using two different normalization approaches was compared: LV mass-for-LBM and LV mass index-for-age percentiles. Among 231 children at risk for LVH, on average, relative LV mass was higher using the LV mass index-for-age percentile method than the LV mass-for-LBM percentile method. LVH was more likely to be diagnosed among overweight children and less likely among thin children. This study provides new LV mass reference centiles expressing LV mass relative to LBM, the strongest determinant of LV mass. These reference centiles may allow more accurate stratification of cardiovascular risk in children. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

The Effects of Tooth Brushing on Whole Salivary Flow Rate in Older Adults

PubMed Central

Trottier, K.; Garrick, R.; Mascarenhas, T.; Jang, Y.

2018-01-01

Objectives (1) To determine whether manual (MTB), or electric, tooth brushing (ETB) modulates whole salivary flow rate in older adults who are free of systemic disease. (2) To determine the duration of the brushing-related modulation of salivary flow rate. (3) To compare salivary flow rate modulation associated with MTB and ETB. Method Twenty-one adults aged 60 years and older participated in two experimental sessions during which they used a manual, or electric, toothbrush to brush their teeth, tongue, and palate. Whole salivary flow rates were determined using the draining method before, during, and after brushing. Differences in salivary flow rates across time periods, and between conditions, were examined using paired samples t-tests applying a Holm-Bonferroni sequential procedure (pcorr < 0.0045). The relationship between tooth brushing and age with respect to maximum salivary flow rate increase was examined using Pearson's correlation coefficient (p < 0.05). Results/Conclusion Whole salivary flow rates increased during, and for up to 5 minutes following, tooth brushing in adults aged 60 years and older who were free of systemic disease. The salivary effects of MTB and ETB were not significantly different. A moderate, positive correlation was observed between tooth-brushing-related maximum salivary flow rate increase and age. PMID:29682540

The effect of filtering on the determination of lunar tides

NASA Astrophysics Data System (ADS)

Palumbo, A.; Mazzarella, A.

1980-01-01

The determination of lunar tides obtained by combination of a filtering process and the fixed lunar age technique is proposed. It is shown that such a method allows a reduction of the signal-to-noise ratio without altering the amplitude and the phase angle of the signal. It consequently allows the significant determination of the lunar semidiurnal component M2 from the series of data shorter than those required by other methods and the deduction of other interesting lunisolar components which have not previously been significantly determined in surface pressure and temperature data. The analysis of the data for Gan, Vesuvian Observatory and the Eiffel Tower have provided new determinations of L2(p) and have allowed comparison between the results obtained by the present and other methods.

A Lunar Chronology

ERIC Educational Resources Information Center

Schaeffer, Oliver A.

1973-01-01

Discusses methods used in determination of absolute isotopic ages for the returned lunar material, including the uranium-lead, rubidium-strontium, and argon 40-argon 39 ratio methods. Indicates that there would exist a basin-forming bombardment period for the Moon extending over at least 300 million years. (CC)

Development of direct dating methods of fault gouges: Deep drilling into Nojima Fault, Japan

NASA Astrophysics Data System (ADS)

Miyawaki, M.; Uchida, J. I.; Satsukawa, T.

2017-12-01

It is crucial to develop a direct dating method of fault gouges for the assessment of recent fault activity in terms of site evaluation for nuclear power plants. This method would be useful in regions without Late Pleistocene overlying sediments. In order to estimate the age of the latest fault slip event, it is necessary to use fault gouges which have experienced high frictional heating sufficient for age resetting. It is said that frictional heating is higher in deeper depths, because frictional heating generated by fault movement is determined depending on the shear stress. Therefore, we should determine the reliable depth of age resetting, as it is likely that fault gouges from the ground surface have been dated to be older than the actual age of the latest fault movement due to incomplete resetting. In this project, we target the Nojima fault which triggered the 1995 Kobe earthquake in Japan. Samples are collected from various depths (300-1,500m) by trenching and drilling to investigate age resetting conditions and depth using several methods including electron spin resonance (ESR) and optical stimulated luminescence (OSL), which are applicable to ages later than the Late Pleistocene. The preliminary results by the ESR method show approx. 1.1 Ma1) at the ground surface and 0.15-0.28 Ma2) at 388 m depth, respectively. These results indicate that samples from deeper depths preserve a younger age. In contrast, the OSL method dated approx. 2,200 yr1) at the ground surface. Although further consideration is still needed as there is a large margin of error, this result indicates that the age resetting depth of OSL is relatively shallow due to the high thermosensitivity of OSL compare to ESR. In the future, we plan to carry out further investigation for dating fault gouges from various depths up to approx. 1,500 m to verify the use of these direct dating methods.1) Kyoto University, 2017. FY27 Commissioned for the disaster presentation on nuclear facilities (Drilling borehole survey at the Nojima fault), Technical Report. (in Japanese)2) T. Fukuchi, 2001, Assessment of fault activity by ESR dating of fault gouge; an example of the 500m core samples drilled into the Nojima Earthquake Fault in Japan. Quaternary Science Reviews, 20, 1005-1008.

A Validation Method to Determine Missing Years of Birth in a Cohort Study of Shipyard Workers Using Social Security Number.

PubMed

Cabasag, Citadel J; Ziogas, Argyrios; Shehata, Merna; Anton-Culver, Hoda

2016-06-01

The objective of the study is to evaluate the generalizability and feasibility of a prediction method developed by Block et al (1983) to estimate missing age of workers by using their Social Security Numbers (SSNs). Our study used a retrospective occupational cohort of about 15,000 workers from the Long Beach Naval Shipyard (1978 to 1985). Our results showed an 89.2% agreement (P < 0.0001) between the predicted and observed years of birth using Block's method. The correlation increased to 93.1% (P < 0.0001) after our modifications by removing workers with SSNs issued in U.S. territories. The method performed better in shipyard workers who obtained their SSNs after 1950. Although the method is useful in imputing missing age, the accuracy is dependent on the year, age, and location of SSN issuance.

Asteroseismic modelling of solar-type stars: internal systematics from input physics and surface correction methods

NASA Astrophysics Data System (ADS)

Nsamba, B.; Campante, T. L.; Monteiro, M. J. P. F. G.; Cunha, M. S.; Rendle, B. M.; Reese, D. R.; Verma, K.

2018-04-01

Asteroseismic forward modelling techniques are being used to determine fundamental properties (e.g. mass, radius, and age) of solar-type stars. The need to take into account all possible sources of error is of paramount importance towards a robust determination of stellar properties. We present a study of 34 solar-type stars for which high signal-to-noise asteroseismic data is available from multi-year Kepler photometry. We explore the internal systematics on the stellar properties, that is, associated with the uncertainty in the input physics used to construct the stellar models. In particular, we explore the systematics arising from: (i) the inclusion of the diffusion of helium and heavy elements; and (ii) the uncertainty in solar metallicity mixture. We also assess the systematics arising from (iii) different surface correction methods used in optimisation/fitting procedures. The systematics arising from comparing results of models with and without diffusion are found to be 0.5%, 0.8%, 2.1%, and 16% in mean density, radius, mass, and age, respectively. The internal systematics in age are significantly larger than the statistical uncertainties. We find the internal systematics resulting from the uncertainty in solar metallicity mixture to be 0.7% in mean density, 0.5% in radius, 1.4% in mass, and 6.7% in age. The surface correction method by Sonoi et al. and Ball & Gizon's two-term correction produce the lowest internal systematics among the different correction methods, namely, ˜1%, ˜1%, ˜2%, and ˜8% in mean density, radius, mass, and age, respectively. Stellar masses obtained using the surface correction methods by Kjeldsen et al. and Ball & Gizon's one-term correction are systematically higher than those obtained using frequency ratios.

Two new oro-cervical radiographic indexes for chronological age estimation: a pilot study on an Italian population.

PubMed

Lajolo, Carlo; Giuliani, Michele; Cordaro, Massimo; Marigo, Luca; Marcelli, Antonio; Fiorillo, Fabio; Pascali, Vincenzo L; Oliva, Antonio

2013-10-01

Chronological age (CA) plays a fundamental role in forensic dentistry (i.e. personal identification and evaluation of imputability). Even though several studies outlined the association between biological and chronological age, there is still great variability in the estimates. The aim of this study was to determine the possible correlation between biological and CA age through the use of two new radiographic indexes (Oro-Cervical Radiographic Simplified Score - OCRSS and Oro-Cervical Radiographic Simplified Score Without Wisdom Teeth - OCRSSWWT) that are based on the oro-cervical area. Sixty Italian Caucasian individuals were divided into 3 groups according to their CA: Group 1: CAG 1 = 8-14 yr; Group 2: CAG 2 = 14-18 yr; Group 3: CAG 3 = 18-25 yr; panorexes and standardised cephalograms were evaluated according Demirjian's Method for dental age calculation (DM), Cervical Vertebral Maturation method for skeletal age calculation (CVMS) and Third Molar Development for age estimation (TMD). The stages of each method were simplified in order to generate OCRSS, which summarized the simplified scores of the three methods, and OCRSSWWT, which summarized the simplified DM and CVMS scores. There was a significant correlation between OCRSS and CAGs (Slope = 0.954, p < 0.001, R-squared = 0.79) and between OCRSSWWT and CAGs (Slope = 0.863, p < 0.001, R-squared = 0.776). Even though the indexes, especially OCRSS, appear to be highly reliable, growth variability among individuals can deeply influence the anatomical changes from childhood to adulthood. A multi-disciplinary approach that considers many different biomarkers could help make radiological age determination more reliable when it is used to predict CA. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Growth rates of young-of-year shovelnose sturgeon in the Upper Missouri River

USGS Publications Warehouse

Braaten, P. J.; Fuller, D.B.

2007-01-01

Information on growth during the larval and young-of-year life stages in natural river environments is generally lacking for most sturgeon species. In this study, methods for estimating ages and quantifying growth were developed for field-sampled larval and young-of-year shovelnose sturgeon Scaphirhynchus platorynchus in the upper Missouri River. First, growth was assessed by partitioning samples of young-of-year shovelnose sturgeon into cohorts, and regressing weekly increases in cohort mean length on sampling date. This method quantified relative growth because ages of the cohorts were unknown. Cohort increases in mean length among sampling dates were positively related (P < 0.05, r2 > 0.59 for all cohorts) to sampling date, and yielded growth rate estimates of 0.80–2.95 mm day−1 (2003) and 0.44–2.28 mm day−1 (2004). Highest growth rates occurred in the largest (and earliest spawned) cohorts. Second, a method was developed to estimate cohort hatch dates, thus age on date of sampling could be determined. This method included quantification of post-hatch length increases as a function of water temperature (growth capacity; mm per thermal unit, mm TU−1), and summation of mean daily water temperatures to achieve the required number of thermal units that corresponded to post-hatch lengths of shovelnose sturgeon on sampling dates. For six of seven cohorts of shovelnose sturgeon analyzed, linear growth models (r2 ≥ 0.65, P < 0.0001) or Gompertz growth models (r2 ≥ 0.83, P < 0.0001) quantified length-at-age from hatch through 55 days post-hatch (98–100 mm). Comparisons of length-at-age derived from the growth models indicated that length-at-age was greater for the earlier-hatched cohorts than later-hatched cohorts. Estimated hatch dates for different cohorts were corroborated based on the dates that newly-hatched larval shovelnose sturgeon were sampled in the drift. These results provide the first quantification of growth dynamics for field-sampled age-0 shovelnose sturgeon in a natural river environment, and provide an accurate method for estimating age of wild-caught individuals. Methods of age determination used in this study have applications to sturgeons in other regions, but require additional testing and validation.

Forensic quest for age determination of bloodstains.

PubMed

Bremmer, Rolf H; de Bruin, Karla G; van Gemert, Martin J C; van Leeuwen, Ton G; Aalders, Maurice C G

2012-03-10

Bloodstains at crime scenes are among the most important types of evidence for forensic investigators. They can be used for DNA-profiling for verifying the suspect's identity or for pattern analysis in order to reconstruct the crime. However, until now, using bloodstains to determine the time elapsed since the crime was committed is still not possible. From a criminalistic point of view, an accurate estimation of when the crime was committed enables to verify witnesses' statements, limits the number of suspects and assesses alibis. Despite several attempts and exploration of many technologies during a century, no method has been materialized into forensic practice. This review gives an overview of an extensive search in scientific literature of techniques that address the quest for age determination of bloodstains. We found that most techniques are complementary to each other, in short as well as long term age determination. Techniques are compared concerning their sensitivity for short and long term ageing of bloodstains and concerning their possible applicability to be used on a crime scene. In addition, experimental challenges like substrate variation, interdonor variation and environmental influences are addressed. Comparison of these techniques contributes to our knowledge of the physics and biochemistry in an ageing bloodstain. Further improvement and incorporation of environmental factors are necessary to enable age determination of bloodstains to be acceptable in court. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Computerized Bone Age Estimation Using Deep Learning Based Program: Evaluation of the Accuracy and Efficiency.

PubMed

Kim, Jeong Rye; Shim, Woo Hyun; Yoon, Hee Mang; Hong, Sang Hyup; Lee, Jin Seong; Cho, Young Ah; Kim, Sangki

2017-12-01

The purpose of this study is to evaluate the accuracy and efficiency of a new automatic software system for bone age assessment and to validate its feasibility in clinical practice. A Greulich-Pyle method-based deep-learning technique was used to develop the automatic software system for bone age determination. Using this software, bone age was estimated from left-hand radiographs of 200 patients (3-17 years old) using first-rank bone age (software only), computer-assisted bone age (two radiologists with software assistance), and Greulich-Pyle atlas-assisted bone age (two radiologists with Greulich-Pyle atlas assistance only). The reference bone age was determined by the consensus of two experienced radiologists. First-rank bone ages determined by the automatic software system showed a 69.5% concordance rate and significant correlations with the reference bone age (r = 0.992; p < 0.001). Concordance rates increased with the use of the automatic software system for both reviewer 1 (63.0% for Greulich-Pyle atlas-assisted bone age vs 72.5% for computer-assisted bone age) and reviewer 2 (49.5% for Greulich-Pyle atlas-assisted bone age vs 57.5% for computer-assisted bone age). Reading times were reduced by 18.0% and 40.0% for reviewers 1 and 2, respectively. Automatic software system showed reliably accurate bone age estimations and appeared to enhance efficiency by reducing reading times without compromising the diagnostic accuracy.

Statistical inference for template aging

NASA Astrophysics Data System (ADS)

Schuckers, Michael E.

2006-04-01

A change in classification error rates for a biometric device is often referred to as template aging. Here we offer two methods for determining whether the effect of time is statistically significant. The first of these is the use of a generalized linear model to determine if these error rates change linearly over time. This approach generalizes previous work assessing the impact of covariates using generalized linear models. The second approach uses of likelihood ratio tests methodology. The focus here is on statistical methods for estimation not the underlying cause of the change in error rates over time. These methodologies are applied to data from the National Institutes of Standards and Technology Biometric Score Set Release 1. The results of these applications are discussed.

Novel calibration for LA-ICP-MS-based fission-track thermochronology

NASA Astrophysics Data System (ADS)

Soares, C. J.; Guedes, S.; Hadler, J. C.; Mertz-Kraus, R.; Zack, T.; Iunes, P. J.

2014-01-01

We present a novel age-equation calibration for fission-track age determinations by laser ablation inductively coupled plasma mass spectrometry. This new calibration incorporates the efficiency factor of an internal surface, [ ηq]is, which is obtained by measuring the projected fission-track length, allowing the determination of FT ages directly using the recommended spontaneous fission decay constant. Also, the uranium concentrations in apatite samples are determined using a Durango (Dur-2, 7.44 μg/g U) crystal and a Mud Tank (MT-7, 6.88 μg/g U) crystal as uranium reference materials. The use of matrix-matched reference materials allows a reduction in the uncertainty of the uranium measurements to those related to counting statistics, which are ca. 1 % taking into account that no extra source of uncertainty has to be considered. The equations as well as the matrix-matched reference materials are evaluated using well-dated samples from Durango, Fish Canyon Tuff, and Limberg as unknown samples. The results compare well with their respective published ages determined through other dating methods. Additionally, the results agree with traditional fission-track ages using both the zeta approach and the absolute approach, suggesting that the calibration presented in this work can be robustly applied in geological context. Furthermore, considering that fission-track ages can be determined without an age standard sample, the fission-track thermochronology approach presented here is assumed to be a valuable dating tool.

On the Importance of Age-Adjustment Methods in Ecological Studies of Social Determinants of Mortality

PubMed Central

Milyo, Jeffrey; Mellor, Jennifer M

2003-01-01

Objective To illustrate the potential sensitivity of ecological associations between mortality and certain socioeconomic factors to different methods of age-adjustment. Data Sources Secondary analysis employing state-level data from several publicly available sources. Crude and age-adjusted mortality rates for 1990 are obtained from the U.S. Centers for Disease Control. The Gini coefficient for family income and percent of persons below the federal poverty line are from the U.S. Bureau of Labor Statistics. Putnam's (2000) Social Capital Index was downloaded from ; the Social Mistrust Index was calculated from responses to the General Social Survey, following the method described in Kawachi et al. (1997). All other covariates are obtained from the U.S. Census Bureau. Study Design We use least squares regression to estimate the effect of several state-level socioeconomic factors on mortality rates. We examine whether these statistical associations are sensitive to the use of alternative methods of accounting for the different age composition of state populations. Following several previous studies, we present results for the case when only mortality rates are age-adjusted. We contrast these results with those obtained from regressions of crude mortality on age variables. Principal Findings Different age-adjustment methods can cause a change in the sign or statistical significance of the association between mortality and various socioeconomic factors. When age variables are included as regressors, we find no significant association between mortality and either income inequality, minority racial concentration, or social capital. Conclusions Ecological associations between certain socioeconomic factors and mortality may be extremely sensitive to different age-adjustment methods. PMID:14727797

Monitoring bruise age using visible diffuse reflectance spectroscopy

NASA Astrophysics Data System (ADS)

McMurdy, John W.; Duffy, Susan; Crawford, Gregory P.

2007-02-01

The ability to determine the age of a bruise of unknown age mechanism is important in matters of domestic and child abuse and forensics. While physicians are asked to make clinical judgment on the age of a bruise using color and tenderness, studies have shown that a physicians estimate is highly inaccurate and in cases no better than chance alone. We present here the temporal progression of reflection spectrum collected from accidentally inflicted contusions in adult and child study participants with a synopsis of the observed phenomena. Reflection spectra collected using a portable fiber optic reflection spectrometer can track the increase in extravasated hemoglobin from trauma caused blood vessel rupture and subsequent removal of this hemoglobin occurring concurrent with an increase in the absorption attributed to the breakdown product bilirubin. We hypothesize that this time dependent pattern can be used to determine the age of an unknown bruise in an individual provided rate constant information for the patient can be determined in a controlled calibration bruise. Using reflection spectra to estimate bruise age can provide a rapid and noninvasive method to improve the ability of physicians in dating the age of a contusion.

The Impact of Therapeutic Recreational Gymnastic Exercise on Basic Motor Skills of Hearing-Impaired Children Aged between 6 and 9 Years

ERIC Educational Resources Information Center

Demirel, Nurcan

2018-01-01

Purpose: The purpose of the current study is to investigate the impact of therapeutic recreational gymnastic exercises on basic motor skills of hearing-impaired children aged between 6-9 years. Material and Method: 18 students (12 boys; 6 girls) between the ages of 6-9 years participated in the study. 9 of these students were determined as…

Dietary supplementation with the polyphenol-rich açaí pulps (Euterpe oleracea Mart. and Euterpe precatoria Mart.) improves cognition in aged rats and attenuates inflammatory signaling in BV-2 microglial cells

USDA-ARS?s Scientific Manuscript database

Objectives: The present study was carried out to determine if lyophilized acai fruit pulp (genus, Euterpe), rich in polyphenolics and other bioactive antioxidant and anti-inflammatory phytochemicals, is efficacious in reversing age-related cognitive deficits in aged rats. Methods: The diets of 19-mo...

On non-invasive 2D and 3D Chromatic White Light image sensors for age determination of latent fingerprints.

PubMed

Merkel, Ronny; Gruhn, Stefan; Dittmann, Jana; Vielhauer, Claus; Bräutigam, Anja

2012-10-10

The feasibility of 2D-intensity and 3D-topography images from a non-invasive Chromatic White Light (CWL) sensor for the age determination of latent fingerprints is investigated. The proposed method might provide the means to solve the so far unresolved issue of determining a fingerprints age in forensics. Conducting numerous experiments for an indoor crime scene using selected surfaces, different influences on the aging of fingerprints are investigated and the resulting aging variability is determined in terms of inter-person, intra-person, inter-finger and intra-finger variation. Main influence factors are shown to be the sweat composition, temperature, humidity, wind, UV-radiation, surface type, contamination of the finger with water-containing substances, resolution and measured area size, whereas contact time, contact pressure and smearing of the print seem to be of minor importance. Such influences lead to a certain experimental variability in inter-person and intra-person variation, which is higher than the inter-finger and intra-finger variation. Comparing the aging behavior of 17 different features using 1490 time series with a total of 41,520 fingerprint images, the great potential of the CWL technique in combination with the binary pixel feature from prior work is shown. Performing three different experiments for the classification of fingerprints into the two time classes [0, 5 h] and [5, 24 h], a maximum classification performance of 79.29% (kappa=0.46) is achieved for a general case, which is further improved for special cases. The statistical significance of the two best-performing features (both binary pixel versions based on 2D-intensity images) is manually shown and a feature fusion is performed, highlighting the strong dependency of the features on each other. It is concluded that such method might be combined with additional capturing devices, such as microscopes or spectroscopes, to a very promising age estimation scheme. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Determination of Fundamental Properties of an M31 Globular Cluster from Main-Sequence Photometry

NASA Astrophysics Data System (ADS)

Ma, Jun; Wu, Zhenyu; Wang, Song; Fan, Zhou; Zhou, Xu; Wu, Jianghua; Jiang, Zhaoji; Chen, Jiansheng

2010-10-01

M31 globular cluster B379 is the first extragalactic cluster whose age was determined by main-sequence photometry. In the main-sequence photometric method, the age of a cluster is obtained by fitting its color-magnitude diagram (CMD) with stellar evolutionary models. However, different stellar evolutionary models use different parameters of stellar evolution, such as range of stellar masses, different opacities and equations of state, and different recipes, and so on. So, it is interesting to check whether different stellar evolutionary models can give consistent results for the same cluster. Brown et al. constrained the age of B379 by comparing its CMD with isochrones of the 2006 VandenBerg models. Using SSP models of Bruzual & Charlot and its multiphotometry, ZMa et al. independently determined the age of B379, which is in good agreement with the determination of Brown et al. The models of Bruzual & Charlot are calculated based on the Padova evolutionary tracks. It is necessary to check whether the age of B379 as determined based on the Padova evolutionary tracks is in agreement with the determination of Brown et al.. In this article, we redetermine the age of B379 using isochrones of the Padova stellar evolutionary models. In addition, the metal abundance, the distance modulus, and the reddening value for B379 are reported. The results obtained are consistent with the previous determinations, which include the age obtained by Brown et al. This article thus confirms the consistency of the age scale of B379 between the Padova isochrones and the 2006 VandenBerg isochrones; i.e., the comparison between the results of Brown et al. and Ma et al. is meaningful. The results reported in this article of values found for B379 are: metallicity [M/H] = log(Z/Z ⊙) = -0.325, age τ = 11.0 ± 1.5 Gyr, reddening E(B - V) = 0.08, and distance modulus (m - M)0 = 24.44 ± 0.10.

Shifting between self-governing and being governed: a qualitative study of older persons' self-determination.

PubMed

Ottenvall Hammar, Isabelle; Dahlin-Ivanoff, Synneve; Wilhelmson, Katarina; Eklund, Kajsa

2014-11-28

Older persons' right to exercise self-determination in daily life is supported by several laws. Research shows that older persons' self-determination is not fully respected within the healthcare sector. In order to enable and enhance older persons' self-determination, extensive knowledge of older persons' self-determination is needed. The aim of this study was to explore experiences of self-determination when developing dependence in daily activities among community-dwelling persons 80 years and older. Qualitative interviews were performed in accordance with a grounded theory method, with 11 persons aged 84-95 years who were beginning to develop dependence in daily activities. The data analysis revealed the core category, "Self-determination - shifting between self-governing and being governed". The core category comprised three categories: "Struggling against the aging body", "Decision-making is relational", and "Guarding one's own independence". Self-determination in daily activities was related to a shifting, which was two-fold, and varied between self-governing and being governed by the aging body, or by others. The findings imply a need to adopt a person-centered approach where the older persons' own preferences and needs are in focus, in order to enhance their possibilities to exercise self-determination.

Determination of Age-Dependent Reference Ranges for Coagulation Tests Performed Using Destiny Plus

PubMed Central

Arslan, Fatma Demet; Serdar, Muhittin; Merve Ari, Elif; Onur Oztan, Mustafa; Hikmet Kozcu, Sureyya; Tarhan, Huseyin; Cakmak, Ozgur; Zeytinli, Merve; Yasar Ellidag, Hamit

2016-01-01

Background In order to apply the right treatment for hemostatic disorders in pediatric patients, laboratory data should be interpreted with age-appropriate reference ranges. Objectives The purpose of this study was to determining age-dependent reference range values for prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen tests, and D-dimer tests. Materials and Methods A total of 320 volunteers were included in the study with the following ages: 1 month - 1 year (n = 52), 2 - 5 years (n = 50), 6 - 10 years (n = 48), 11 - 17 years (n = 38), and 18 - 65 years (n = 132). Each volunteer completed a survey to exclude hemostatic system disorder. Using a nonparametric method, the lower and upper limits, including 95% distribution and 90% confidence intervals, were calculated. Results No statistically significant differences were found between PT and aPTT values in the groups consisting of children. Thus, the reference ranges were separated into child and adult age groups. PT and aPTT values were significantly higher in the children than in the adults. Fibrinogen values in the 6 - 10 age group and the adult age group were significantly higher than in the other groups. D-dimer levels were significantly lower in those aged 2 - 17; thus, a separate reference range was established. Conclusions These results support other findings related to developmental hemostasis, confirming that adult and pediatric age groups should be evaluated using different reference ranges. PMID:27617078

99mTc-d,l-HMPAO and SPECT of the brain in normal aging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waldemar, G.; Hasselbalch, S.G.; Andersen, A.R.

1991-05-01

Single photon emission computed tomography (SPECT) with 99mTc-d,l-hexamethylpropyleneamine oxime (99mTc-d,l-HMPAO) was used to determine global and regional CBF in 53 healthy subjects aged 21-83 years. For the whole group, global CBF normalized to the cerebellum was 86.4% +/- 8.4 (SD). The contribution of age, sex, and atrophy to variations in global CBF was studied using stepwise multiple regression analysis. There was a significant negative correlation of global CBF with subjective ratings of cortical atrophy, but not with ratings of ventricular size, Evans ratio, sex, or age. In a subgroup of 33 subjects, in whom volumetric measurements of atrophy were performed,more » cortical atrophy was the only significant determinant for global CBF, accounting for 27% of its variance. Mean global CBF as measured with the 133Xe inhalation technique and SPECT was 54 +/- 9 ml/100 g/min and did not correlate significantly with age. There was a preferential decline of CBF in the frontal cortex with advancing age. The side-to-side asymmetry of several regions of interest increased with age. A method was described for estimation of subcortical CBF, which decreased with advancing cortical atrophy. The relative area of the subcortical low-flow region increased with age. These results are useful in distinguishing the effects of age and simple atrophy from disease effects, when the 99mTc-d,l-HMPAO method is used.« less

Physical Fitness, Academic Achievement, and Socioeconomic Status in School-Aged Youth

ERIC Educational Resources Information Center

Coe, Dawn P.; Peterson, Thomas; Blair, Cheryl; Schutten, Mary C.; Peddie, Heather

2013-01-01

Background: This study examined the association between physical fitness and academic achievement and determined the influence of socioeconomic status (SES) on the association between fitness and academic achievement in school-aged youth. Methods: Overall, 1,701 third-, sixth-, and ninth-grade students from 5 school districts participated in the…

Overweight and Obesity among Children with Developmental Disabilities

ERIC Educational Resources Information Center

De, Sukanya; Small, Jacqueline; Baur, Louise A.

2008-01-01

Background: The aim of this study was to determine the prevalence of overweight and obesity in children with developmental disabilities attending a metropolitan Diagnosis and Assessment Service. Method: A retrospective chart review was carried out for 98 children (67 male) aged 2-18 years. Data on age, sex, weight, height, and severity of…

Cortical Reorganization of Language Functioning Following Perinatal Left MCA Stroke

ERIC Educational Resources Information Center

Tillema, Jan-Mendelt; Byars, Anna W.; Jacola, Lisa M.; Schapiro, Mark B.; Schmithorst, Vince J.; Szaflarski, Jerzy P.; Holland, Scott K.

2008-01-01

Objective: Functional MRI was used to determine differences in patterns of cortical activation between children who suffered perinatal left middle cerebral artery (MCA) stroke and healthy children performing a silent verb generation task. Methods: Ten children with prior perinatal left MCA stroke (age 6-16 years) and ten healthy age matched…

The influence of physiological status on age prediction of Anopheles arabiensis using near infra-red spectroscopy

USDA-ARS?s Scientific Manuscript database

Determining the age of malaria vectors is essential for evaluating the impact of interventions that reduce the survival of wild mosquito populations and for estimating changes in vectorial capacity. Near infra-red spectroscopy (NIRS) is a simple and non-destructive method that has been used to deter...

Application of age estimation methods based on teeth eruption: how easy is Olze method to use?

PubMed

De Angelis, D; Gibelli, D; Merelli, V; Botto, M; Ventura, F; Cattaneo, C

2014-09-01

The development of new methods for age estimation has become with time an urgent issue because of the increasing immigration, in order to estimate accurately the age of those subjects who lack valid identity documents. Methods of age estimation are divided in skeletal and dental ones, and among the latter, Olze's method is one of the most recent, since it was introduced in 2010 with the aim to identify the legal age of 18 and 21 years by evaluating the different stages of development of the periodontal ligament of the third molars with closed root apices. The present study aims at verifying the applicability of the method to the daily forensic practice, with special focus on the interobserver repeatability. Olze's method was applied by three different observers (two physicians and one dentist without a specific training in Olze's method) to 61 orthopantomograms from subjects of mixed ethnicity aged between 16 and 51 years. The analysis took into consideration the lower third molars. The results provided by the different observers were then compared in order to verify the interobserver error. Results showed that interobserver error varies between 43 and 57 % for the right lower third molar (M48) and between 23 and 49 % for the left lower third molar (M38). Chi-square test did not show significant differences according to the side of teeth and type of professional figure. The results prove that Olze's method is not easy to apply when used by not adequately trained personnel, because of an intrinsic interobserver error. Since it is however a crucial method in age determination, it should be used only by experienced observers after an intensive and specific training.

Prediction of adult height in girls: the Beunen-Malina-Freitas method.

PubMed

Beunen, Gaston P; Malina, Robert M; Freitas, Duarte L; Thomis, Martine A; Maia, José A; Claessens, Albrecht L; Gouveia, Elvio R; Maes, Hermine H; Lefevre, Johan

2011-12-01

The purpose of this study was to validate and cross-validate the Beunen-Malina-Freitas method for non-invasive prediction of adult height in girls. A sample of 420 girls aged 10-15 years from the Madeira Growth Study were measured at yearly intervals and then 8 years later. Anthropometric dimensions (lengths, breadths, circumferences, and skinfolds) were measured; skeletal age was assessed using the Tanner-Whitehouse 3 method and menarcheal status (present or absent) was recorded. Adult height was measured and predicted using stepwise, forward, and maximum R (2) regression techniques. Multiple correlations, mean differences, standard errors of prediction, and error boundaries were calculated. A sample of the Leuven Longitudinal Twin Study was used to cross-validate the regressions. Age-specific coefficients of determination (R (2)) between predicted and measured adult height varied between 0.57 and 0.96, while standard errors of prediction varied between 1.1 and 3.9 cm. The cross-validation confirmed the validity of the Beunen-Malina-Freitas method in girls aged 12-15 years, but at lower ages the cross-validation was less consistent. We conclude that the Beunen-Malina-Freitas method is valid for the prediction of adult height in girls aged 12-15 years. It is applicable to European populations or populations of European ancestry.

Estimation of Correlation between Chronological Age, Skeletal Age and Dental Age in Children- A Cross-sectional Study.

PubMed

Macha, Madhulika; Lamba, Bharti; Avula, Jogendra Sai Sankar; Muthineni, Sridhar; Margana, Pratap Gowd Jai Shankar; Chitoori, Prasad

2017-09-01

In the modern era, identification and determination of age is imperative for diversity of reasons that include disputed birth records, premature delivery, legal issues and for validation of birth certificate for school admissions, adoption, marriage, job and immigration. Several growth assessment parameters like bone age, dental age and the combination of both have been applied for different population with variable outcomes. It has been well documented that the chronological age does not necessarily correlate with the maturational status of a child. Hence, efforts were made to determine a child's developmental age by using dental age (calcification of teeth) and skeletal age (skeletal maturation). The present study was aimed to correlate the chronological age, dental age and skeletal age in children from Southeastern region of Andhra Pradesh, India. Out of the total 900 screened children, only 100 subjects between age groups of 6-14 years with a mean age of 11.3±2.63 for males and 10.77±2.24 for females were selected for the study. Dental age was calculated by Demirjian method and skeletal age by modified Middle Phalanx of left hand third finger (MP3) method. Pearson's and Spearman's correlation tests were done to estimate the correlation between chronological, dental and skeletal ages among study population. There was a significant positive correlation between chronological age, dental age and all stages of MP3 among males. Similar results were observed in females, except for a non-significant moderate correlation between chronological age and dental age in the H stage of the MP3 region. The results of the present study revealed correlation with statistical significance (p<0.05) between chronological, dental and skeletal ages among all the subjects (48 males and 52 females) and females attained maturity earlier than males in the present study population.

Validation of fan beam dual energy x ray absorptiometry for body composition assessment in adults aged 18–45 years

PubMed Central

Norcross, J; Van Loan, M D

2004-01-01

Background: Pencil beam dual energy x ray absorptiometry (DXA) has been shown to provide valid estimates of body fat (%BF), but DXA fan beam technology has not been adequately tested to determine its validity. Objective: To compare %BF estimated from fan beam DXA with %BF determined using two and three compartment (2C, 3C) models. Methods: Men (n = 25) and women (n = 31), aged 18–41 years, participated in the study. Body density, from hydrostatic weighing, was used in the 2C estimate of %BF; DXA was used to determine bone mineral content (BMC) for the 3C estimate of %BF calculated using body density and BMC (3CBMC). DXA was also used to determine %BF. Analysis of variance was used to test for significant differences in %BF between sexes and among methods. Results: Women were significantly shorter, weighed less, had less fat free mass, and a higher %BF than men. No significant differences were found among methods (2C, 3CBMC, DXA) for determination of %BF in either sex. Although not significant, Bland-Altman plots showed that DXA gave higher values for %BF than the 2C and 3CBMC methods. Conclusion: DXA determination of %BF was not different from that of the 2C and 3CBMC models in this group of young adults. However, to validate fan beam DXA fully as a method for body composition assessment in a wide range of individuals and populations, comparisons are needed that use a 4C model with a measure of total body water and BMC. PMID:15273189

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eppich, Gary R.; Williams, Ross W.; Gaffney, Amy M.

Here, age dating of nuclear material can provide insight into source and suspected use in nuclear forensic investigations. We report here a method for the determination of the date of most recent chemical purification for uranium materials using the 235U- 231Pa chronometer. Protactinium is separated from uranium and neptunium matrices using anion exchange resin, followed by sorption of Pa to an SiO 2 medium. The concentration of 231Pa is measured by isotope dilution mass spectrometry using 233Pa spikes prepared from an aliquot of 237Np and calibrated in-house using the rock standard Table Mountain Latite and the uranium isotopic standard U100.more » Combined uncertainties of age dates using this method are 1.5 to 3.5 %, an improvement over alpha spectrometry measurement methods. Model ages of five uranium standard reference materials are presented; all standards have concordant 235U- 231Pa and 234U- 230Th model ages.« less

Assessment of Risk Factors of Obesity and Diet on Breast Cancer in Ankara, Turkey

PubMed Central

Alim, Nural Erzurum; Kiziltan, Gul

2016-01-01

Objective: To determine the risk factors of obesity and diet on breast cancer in Ankara, Turkey. Methods: A case-controlled study was carried out on newly diagnosed 40 breast cancer patients [patient group (PC)] and 40 volunteer individuals [control group (CG)] with no diagnosis of cancer and history of cancer in the family with similar characteristics to the age and gender-matched patient group between March and July 2016. All the individuals were administered a questionnaire by face-to-face interview method. Results: The mean menarche age, age at first birth and menopause age were 13.0±1.17, 22.6±3.78 and 44.33±2.39 years in PG and 12.3±0.95, 21.6±2.99, 46.71±2.41 years in CG, respectively. The mean BMI values were determined as 28.1±6.75 kg/m2 in PG and 30.1±6.18 kg/m2 in CG (p>0.05). It was determined that intake of vitamin C and fiber decreases the risk of breast cancer. Also, eating quickly and smoking were risk factors for breast cancer (p<0.05). Conclusion: This study indicated that there are relationships between menarche age, menopause age, and age at first birth, eating quickly, smoking and breast cancer. Conversely, there are significant negative relationships between dietary fiber, vitamin C intake and breast cancer. As a result, it can be said that there is a link between breast cancer and lifestyle factors and a reduction in the risk of developing breast cancer can be achieved through changes in diet, one of the lifestyle factors. PMID:28083060

Numerical-graphical method for describing the creep of damaged highly filled polymer materials

NASA Astrophysics Data System (ADS)

Bykov, D. L.; Martynova, E. D.; Mel'nikov, V. P.

2015-09-01

A method for describing the creep behavior until fracture of a highly filled polymer material previously damaged in preliminary tests is proposed. The constitutive relations are the relations of nonlinear endochronic theory of aging viscoelastic materials (NETAVEM) [1]. The numerical-graphical method for identifying the functions occurring in NETAVEM, which was proposed in [2] for describing loading processes at a constant strain rate, is used here for the first time in creep theory. We use the results of experiments with undamaged and preliminary damaged specimens under the action of the same constant tensile loads. The creep kernel is determined in experiments with an undamaged specimen. The reduced time function contained in NETAVEM is determined from the position of points corresponding to the same values of strain on the creep curves of the damaged and undamaged specimens. An integral equation is solved to obtain the aging function, and then the viscosity function is determined. The knowledge of all functions contained in the constitutive relations permits solving the creep problem for products manufactured from a highly filled polymer material.

Accurate age determinations of several nearby open clusters containing magnetic Ap stars

NASA Astrophysics Data System (ADS)

Silaj, J.; Landstreet, J. D.

2014-06-01

Context. To study the time evolution of magnetic fields, chemical abundance peculiarities, and other characteristics of magnetic Ap and Bp stars during their main sequence lives, a sample of these stars in open clusters has been obtained, as such stars can be assumed to have the same ages as the clusters to which they belong. However, in exploring age determinations in the literature, we find a large dispersion among different age determinations, even for bright, nearby clusters. Aims: Our aim is to obtain ages that are as accurate as possible for the seven nearby open clusters α Per, Coma Ber, IC 2602, NGC 2232, NGC 2451A, NGC 2516, and NGC 6475, each of which contains at least one magnetic Ap or Bp star. Simultaneously, we test the current calibrations of Te and luminosity for the Ap/Bp star members, and identify clearly blue stragglers in the clusters studied. Methods: We explore the possibility that isochrone fitting in the theoretical Hertzsprung-Russell diagram (i.e. log (L/L⊙) vs. log Te), rather than in the conventional colour-magnitude diagram, can provide more precise and accurate cluster ages, with well-defined uncertainties. Results: Well-defined ages are found for all the clusters studied. For the nearby clusters studied, the derived ages are not very sensitive to the small uncertainties in distance, reddening, membership, metallicity, or choice of isochrones. Our age determinations are all within the range of previously determined values, but the associated uncertainties are considerably smaller than the spread in recent age determinations from the literature. Furthermore, examination of proper motions and HR diagrams confirms that the Ap stars identified in these clusters are members, and that the presently accepted temperature scale and bolometric corrections for Ap stars are approximately correct. We show that in these theoretical HR diagrams blue stragglers are particularly easy to identify. Conclusions: Constructing the theoretical HR diagram of a nearby open cluster makes possible an accurate age determination, with well defined uncertainty. This diagnostic of a cluster also provides a useful tool for studying unusual stars such as Ap stars and blue stragglers. Table 3 is available in electronic form at http://www.aanda.org

Data-driven identification of intensity normalization region based on longitudinal coherency of 18F-FDG metabolism in the healthy brain.

PubMed

Zhang, Huiwei; Wu, Ping; Ziegler, Sibylle I; Guan, Yihui; Wang, Yuetao; Ge, Jingjie; Schwaiger, Markus; Huang, Sung-Cheng; Zuo, Chuantao; Förster, Stefan; Shi, Kuangyu

2017-02-01

In brain 18 F-FDG PET data intensity normalization is usually applied to control for unwanted factors confounding brain metabolism. However, it can be difficult to determine a proper intensity normalization region as a reference for the identification of abnormal metabolism in diseased brains. In neurodegenerative disorders, differentiating disease-related changes in brain metabolism from age-associated natural changes remains challenging. This study proposes a new data-driven method to identify proper intensity normalization regions in order to improve separation of age-associated natural changes from disease related changes in brain metabolism. 127 female and 128 male healthy subjects (age: 20 to 79) with brain 18 F-FDG PET/CT in the course of a whole body cancer screening were included. Brain PET images were processed using SPM8 and were parcellated into 116 anatomical regions according to the AAL template. It is assumed that normal brain 18 F-FDG metabolism has longitudinal coherency and this coherency leads to better model fitting. The coefficient of determination R 2 was proposed as the coherence coefficient, and the total coherence coefficient (overall fitting quality) was employed as an index to assess proper intensity normalization strategies on single subjects and age-cohort averaged data. Age-associated longitudinal changes of normal subjects were derived using the identified intensity normalization method correspondingly. In addition, 15 subjects with clinically diagnosed Parkinson's disease were assessed to evaluate the clinical potential of the proposed new method. Intensity normalizations by paracentral lobule and cerebellar tonsil, both regions derived from the new data-driven coherency method, showed significantly better coherence coefficients than other intensity normalization regions, and especially better than the most widely used global mean normalization. Intensity normalization by paracentral lobule was the most consistent method within both analysis strategies (subject-based and age-cohort averaging). In addition, the proposed new intensity normalization method using the paracentral lobule generates significantly higher differentiation from the age-associated changes than other intensity normalization methods. Proper intensity normalization can enhance the longitudinal coherency of normal brain glucose metabolism. The paracentral lobule followed by the cerebellar tonsil are shown to be the two most stable intensity normalization regions concerning age-dependent brain metabolism. This may provide the potential to better differentiate disease-related changes from age-related changes in brain metabolism, which is of relevance in the diagnosis of neurodegenerative disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

Twins and the paradox of dental-age estimations: a caution for researchers and clinicians.

PubMed

Pechníková, M; De Angelis, D; Gibelli, D; Vecchio, V; Cameriere, R; Zeqiri, B; Cattaneo, C

2014-08-01

The biological age difference among twins is frequently an issue in studies of genetic influence on various dental features, particularly dental development. The timing of dental development is a crucial issue also for many clinicians and researchers. The aim of this study was therefore to verify within groups of twins how dental development differs, by applying Demirjian's method, Mincer's charts of development of third molars and two of Cameriere's methods for dental age estimation, which are among the most popular methods both in the clinical and the forensic scenario. The sample consisted of 64 twin pairs: 21 monozygotic, 30 dizygotic same-sex and 13 dizygotic opposite-sex with an age range between 5.8 and 22.6 years. Dental age was determined from radiographs using the mentioned methods. Results showed that dental age of monozygotic twins is not identical even if they share all their genes. The mean intra-pair difference of monozygotic pairs was low and similar to the difference in dizygotic same-sex twins; the maximum difference between monozygotic twins, however, was surprisingly large (nearly two years). This should lead to some circumspection in the interpretation of systematic estimations of dental age both in the clinical and forensic scenario. Copyright © 2014 Elsevier GmbH. All rights reserved.

Determination of advanced glycation endproducts by LC-MS/MS in raw and roasted almonds (Prunus dulcis).

PubMed

Zhang, Gong; Huang, Guangwei; Xiao, Lu; Mitchell, Alyson E

2011-11-23

A sensitive and reliable LC-(ESI)MS/MS method was developed and validated for the simultaneous analysis of five common advanced glycation endproducts (AGEs) after enzymatic digestion in raw and roasted almonds. AGEs included carboxymethyl-lysine (CML), carboxyethyl-lysine (CEL), pyralline (Pyr), argpyrimidine (Arg-p), and pentosidine (Pento-s). This method allows accurate quantitation of free and AGE-protein adducts of target AGEs. Results indicate that CML and CEL are found in both raw and roasted almonds. Pyr was identified for the first time in roasted almonds and accounted for 64.4% of free plus bound measured AGEs. Arg-p and Pento-s were below the limit of detection in all almond samples tested. Free AGEs accounted for 1.3-26.8% of free plus bound measured AGEs, indicating that protein-bound forms predominate. The roasting process significantly increased CML, CEL, and Pyr formation, but no significant correlation was observed between these AGEs and roasting temperature.

Comparison of a clinical gait analysis method using videography and temporal-distance measures with 16-mm cinematography.

PubMed

Stuberg, W A; Colerick, V L; Blanke, D J; Bruce, W

1988-08-01

The purpose of this study was to compare a clinical gait analysis method using videography and temporal-distance measures with 16-mm cinematography in a gait analysis laboratory. Ten children with a diagnosis of cerebral palsy (means age = 8.8 +/- 2.7 years) and 9 healthy children (means age = 8.9 +/- 2.4 years) participated in the study. Stride length, walking velocity, and goniometric measurements of the hip, knee, and ankle were recorded using the two gait analysis methods. A multivariate analysis of variance was used to determine significant differences between the data collected using the two methods. Pearson product-moment correlation coefficients were determined to examine the relationship between the measurements recorded by the two methods. The consistency of performance of the subjects during walking was examined by intraclass correlation coefficients. No significant differences were found between the methods for the variables studied. Pearson product-moment correlation coefficients ranged from .79 to .95, and intraclass coefficients ranged from .89 to .97. The clinical gait analysis method was found to be a valid tool in comparison with 16-mm cinematography for the variables that were studied.

Improved method for sectioning pectoral spines of catfish for age determination

USGS Publications Warehouse

Blouin, Marc A.; Hall, Glenda R.

1990-01-01

The advantages of this method are: (1) spine sections are clear, with uniform thickness and little tissue damage; (2) no time-consuming procedures are necessary; (3) the original spine remains intact for future sectioning; and (4) the thick, single blade does not warp.

Pteridine levels and head weights are correlated with age and colony task in the honey bee, Apis mellifera

PubMed Central

Rinkevich, Frank D.; Margotta, Joseph W.; Pittman, Jean M.; Ottea, James A.

2016-01-01

Background. The age of an insect strongly influences many aspects of behavior and reproduction. The interaction of age and behavior is epitomized in the temporal polyethism of honey bees in which young adult bees perform nurse and maintenance duties within the colony, while older bees forage for nectar and pollen. Task transition is dynamic and driven by colony needs. However, an abundance of precocious foragers or overage nurses may have detrimental effects on the colony. Additionally, honey bee age affects insecticide sensitivity. Therefore, determining the age of a set of individual honey bees would be an important measurement of colony health. Pteridines are purine-based pigment molecules found in many insect body parts. Pteridine levels correlate well with age, and wild caught insects may be accurately aged by measuring pteridine levels. The relationship between pteridines and age varies with a number of internal and external factors among many species. Thus far, no studies have investigated the relationship of pteridines with age in honey bees. Methods. We established single-cohort colonies to obtain age-matched nurse and forager bees. Bees of known ages were also sampled from colonies with normal demographics. Nurses and foragers were collected every 3–5 days for up to 42 days. Heads were removed and weighed before pteridines were purified and analyzed using previously established fluorometric methods. Results. Our analysis showed that pteridine levels significantly increased with age in a linear manner in both single cohort colonies and colonies with normal demography. Pteridine levels were higher in foragers than nurses of the same age in bees from single cohort colonies. Head weight significantly increased with age until approximately 28-days of age and then declined for both nurse and forager bees in single cohort colonies. A similar pattern of head weight in bees from colonies with normal demography was observed but head weight was highest in 8-day old nurse bees and there was no relationship of head weight with age of foragers. Discussion. Although the relationship between pteridine levels and age was significant, variation in the data yielded a +4-day range in age estimation. This allows an unambiguous method to determine whether a bee may be a young nurse or old forager in colonies with altered demographics as in the case of single cohort colonies. Pteridine levels in bees do not correlate with age as well as in other insects. However, most studies used insects reared under tightly controlled laboratory conditions, while we used free-living bees. The dynamics of head weight change with age is likely to be due to growth and atrophy of the hypopharyngeal glands. Taken together, these methods represent a useful tool for assessing the age of an insect. Future studies utilizing these methods will provide a more holistic view of colony health. PMID:27413635

The Effect of Psychosocial Stimulation on Cognition and Behaviour at 6 Years in a Cohort of Term, Low-Birthweight Jamaican Children

ERIC Educational Resources Information Center

Walker, Susan P.; Chang, Susan M.; Younger, Novie; Grantham-McGregor, Sally M.

2010-01-01

Aim: The aim of this study was to determine whether psychosocial stimulation up to the age of 2 years benefits cognition and behaviour at age 6 years in low-birthweight, term-born (LBW-T) children (gestational age greater than or equal to 37wk, birthweight less than 2500g), and to compare LBW-T and normal-birthweight (NBW) children. Method: LBW-T…

Child Sexual Abuse and Persistence of Risky Sexual Behaviors and Negative Sexual Outcomes over Adulthood: Findings from a Birth Cohort

ERIC Educational Resources Information Center

van Roode, Thea; Dickson, Nigel; Herbison, Peter; Paul, Charlotte

2009-01-01

Objectives: To determine the impact of child sexual abuse (CSA) on adult sexual behaviors and outcomes over three age periods. Methods: A longitudinal study of a birth cohort born in Dunedin, New Zealand in 1972/1973 was used. Information on CSA was sought at age 26, and on sexual behaviors and outcomes at ages 21, 26, and 32. Comparisons were…

Obsidian hydration dating of volcanic events

USGS Publications Warehouse

Friedman, I.; Obradovich, J.

1981-01-01

Obsidian hydration dating of volcanic events had been compared with ages of the same events determined by the 14C and KAr methods at several localities. The localities, ranging in age from 1200 to over 1 million yr, include Newberry Craters, Oregon; Coso Hot Springs, California; Salton Sea, California; Yellowstone National Park, Wyoming; and Mineral Range, Utah. In most cases the agreement is quite good. A number of factors including volcanic glass composition and exposuretemperature history must be known in order to relate hydration thickness to age. The effect of composition can be determined from chemical analysis or the refractive index of the glass. Exposure-temperature history requires a number of considerations enumerated in this paper. ?? 1981.

Marine Life Study

NASA Technical Reports Server (NTRS)

1988-01-01

As a result of widespread ocean dumping and other pollution problems, marine scientists at Morgan State University are studying the populations of various marine organisms to determine the effects of pollution. They are also compiling data on the aging of marine organisms. There now exists a new method of determining the age of the surf clam. They are applying digital image processing to clam aging investigations. Computer creates digitized images of clam sections with annual rings. The image is enhanced -- manipulated to emphasize certain features in order to improve and amplify the information that can be extracted from the image. Also useful in other marine organisms that have growth bands making it easier to get an accurate count.

A comparison of the simplified olecranon and digital methods of assessment of skeletal maturity during the pubertal growth spurt.

PubMed

Canavese, F; Charles, Y P; Dimeglio, A; Schuller, S; Rousset, M; Samba, A; Pereira, B; Steib, J-P

2014-11-01

Assessment of skeletal age is important in children's orthopaedics. We compared two simplified methods used in the assessment of skeletal age. Both methods have been described previously with one based on the appearance of the epiphysis at the olecranon and the other on the digital epiphyses. We also investigated the influence of assessor experience on applying these two methods. Our investigation was based on the anteroposterior left hand and lateral elbow radiographs of 44 boys (mean: 14.4; 12.4 to 16.1 ) and 78 girls (mean: 13.0; 11.1 to14.9) obtained during the pubertal growth spurt. A total of nine observers examined the radiographs with the observers assigned to three groups based on their experience (experienced, intermediate and novice). These raters were required to determined skeletal ages twice at six-week intervals. The correlation between the two methods was determined per assessment and per observer groups. Interclass correlation coefficients (ICC) evaluated the reproducibility of the two methods. The overall correlation between the two methods was r = 0.83 for boys and r = 0.84 for girls. The correlation was equal between first and second assessment, and between the observer groups (r ≥ 0.82). There was an equally strong ICC for the assessment effect (ICC ≤ 0.4%) and observer effect (ICC ≤ 3%) for each method. There was no significant (p < 0.05) difference between the levels of experience. The two methods are equally reliable in assessing skeletal maturity. The olecranon method offers detailed information during the pubertal growth spurt, while the digital method is as accurate but less detailed, making it more useful after the pubertal growth spurt once the olecranon has ossified. ©2014 The British Editorial Society of Bone & Joint Surgery.

A video method to study Drosophila sleep.

PubMed

Zimmerman, John E; Raizen, David M; Maycock, Matthew H; Maislin, Greg; Pack, Allan I

2008-11-01

To use video to determine the accuracy of the infrared beam-splitting method for measuring sleep in Drosophila and to determine the effect of time of day, sex, genotype, and age on sleep measurements. A digital image analysis method based on frame subtraction principle was developed to distinguish a quiescent from a moving fly. Data obtained using this method were compared with data obtained using the Drosophila Activity Monitoring System (DAMS). The location of the fly was identified based on its centroid location in the subtracted images. The error associated with the identification of total sleep using DAMS ranged from 7% to 95% and depended on genotype, sex, age, and time of day. The degree of the total sleep error was dependent on genotype during the daytime (P < 0.001) and was dependent on age during both the daytime and the nighttime (P < 0.001 for both). The DAMS method overestimated sleep bout duration during both the day and night, and the degree of these errors was genotype dependent (P < 0.001). Brief movements that occur during sleep bouts can be accurately identified using video. Both video and DAMS detected a homeostatic response to sleep deprivation. Video digital analysis is more accurate than DAMS in fly sleep measurements. In particular, conclusions drawn from DAMS measurements regarding daytime sleep and sleep architecture should be made with caution. Video analysis also permits the assessment of fly position and brief movements during sleep.

Simultaneous detection of changes in protein expression and oxidative modification as function of age and APOE genotype in human APOE-targeted replacement mice

EPA Science Inventory

Background The purpose of this study was to improve the current method for detecting differentially-oxidized (carbonyl-modified) proteins by 2D-DIGE, while at the same time determining changes in total protein expression. Protein oxidation is a widely accepted model of aging and...

Dietary Diversity as a Correlate of Undernutrition among School-Age Children in Southwestern Nigeria

ERIC Educational Resources Information Center

Olumakaiye, M. F.

2013-01-01

Purpose/Objectives: This study was conducted to determine the association between undernutrition and dietary diversity among school-age children in southwestern Nigeria. Methods: A total of 600 school children were randomly selected from six private and six public schools in the region. A standardized FAO-published 24-hour diet recall…

Differences in Age-Related Alterations in Muscle Contraction Properties in Rat Tongue and Hindlimb

ERIC Educational Resources Information Center

Connor, Nadine P.; Ota, Fumikazu; Nagai, Hiromi; Russell, John A.; Leverson, Glen

2008-01-01

Purpose: Because of differences in muscle architecture and biomechanics, the purpose of this study was to determine whether muscle contractile properties of rat hindlimb and tongue were differentially affected by aging. Method: Deep peroneal and hypoglossal nerves were stimulated in 6 young and 7 old Fischer 344-Brown Norway rats to allow…

Establishing Normative Reference Values for Handgrip among Hungarian Youth

ERIC Educational Resources Information Center

Saint-Maurice, Pedro F.; Laurson, Kelly R.; Karsai, István; Kaj, Mónika; Csányi, Tamás

2015-01-01

Purpose: The purpose of this study was to examine age- and sex-related variation in handgrip strength and to determine reference values for the Hungarian population. Method: A sample of 1,086 Hungary youth (aged 11-18 years old; 654 boys and 432 girls) completed a handgrip strength assessment using a handheld dynamometer. Quantile regression was…

Noise Hampers Children's Expressive Word Learning

ERIC Educational Resources Information Center

Riley, Kristine Grohne; McGregor, Karla K.

2012-01-01

Purpose: To determine the effects of noise and speech style on word learning in typically developing school-age children. Method: Thirty-one participants ages 9;0 (years;months) to 10;11 attempted to learn 2 sets of 8 novel words and their referents. They heard all of the words 13 times each within meaningful narrative discourse. Signal-to-noise…

Children's Age-Related Speed--Accuracy Strategies in Intercepting Moving Targets in Two Dimensions

ERIC Educational Resources Information Center

Rothenberg-Cunningham, Alek; Newell, Karl M.

2013-01-01

Purpose: This study investigated the age-related speed--accuracy strategies of children, adolescents, and adults in performing a rapid striking task that allowed the self-selection of the interception position in a virtual, two-dimensional environment. Method: The moving target had curvilinear trajectories that were determined by combinations of…

Neurodevelopmental Outcome in Preterm Infants

ERIC Educational Resources Information Center

Bos, Arend F.; Roze, Elise

2011-01-01

Aim: To determine the distribution of cognitive and motor scores in preterm children, and to establish the influence of brain lesions and decreasing gestational age thereon. Method: One hundred and six very preterm children (63 males, 43 females; gestational age 24.0-31.6wk; birthweight 480-2275g) were assessed for cognition and motor outcome at 6…

Informal Social Networks of People with Profound Intellectual and Multiple Disabilities: Relationship with Age, Communicative Abilities and Current Living Arrangements

ERIC Educational Resources Information Center

Kamstra, A.; van der Putten, A. A. J.; Post, W. J.; Vlaskamp, C.

2015-01-01

Background: People with profound intellectual and multiple disabilities (PIMD) have limited informal social contacts. Research to determine the factors which can positively influence establishing sound informal social contacts is required. Materials and Methods: Regression analysis for 200 people with PIMD was used to analyse how age,…

Investigation of Environmental Problem Solving Skills of Preschool Age Children

ERIC Educational Resources Information Center

Ulutas, Aysegül; Köksalan, Bahadir

2017-01-01

The study was conducted to determine problem-solving skills of preschool age children on environment as well as factors affecting this skill. For this purpose, quantitative and qualitative research methods were used together in the study and the research was designed in the screening model. This study is a descriptive type research since it…

Predicting School Readiness from Neurodevelopmental Assessments at Age 2 Years after Respiratory Distress Syndrome in Infants Born Preterm

ERIC Educational Resources Information Center

Patrianakos-Hoobler, Athena I.; Msall, Michael E.; Huo, Dezheng; Marks, Jeremy D.; Plesha-Troyke, Susan; Schreiber, Michael D.

2010-01-01

Aim: To determine whether neurodevelopmental outcomes at the age of 2 years accurately predict school readiness in children who survived respiratory distress syndrome after preterm birth. Method: Our cohort included 121 preterm infants who received surfactant and ventilation and were enrolled in a randomized controlled study of inhaled nitric…

Luminescence (IRSL) dating of Yeni Rabat church in Artvin, Turkey

NASA Astrophysics Data System (ADS)

Şahiner, Eren; Meriç, Niyazi; Uygun, Selda

2013-05-01

Luminescence dating is a chronological method that has been used extensively in terrestrial materials. In this study, we present Infrared Stimulated Luminescence (IRSL) dating results obtained for sediment and pottery samples taken from Yeni Rabat Church, Ardanuç, Artvin, Turkey. For this purpose, equivalent dose (ED) and annual dose rate (AD) of samples were measured. For annual dose rate, concentrations of radioactive isotopes (U, Th, K) were determined by using a high-purity germanium detector. For the equivalent dose, polymineral fine grain SAR (Single Aliquot Regenerative Dose) and MAAD (Multiple Aliquot Additive Dose) procedures were used. The optimal preheat temperature was determined for sediment and pottery samples. Ages were calculated by Aitken's luminescence age calculation method, which found 710±190 years for the pottery sample and 1450±370 years, 1390±420 years, 1430±310 years, 2210±520 years and 1640±390 years for different sediment samples, respectively. These estimated age ranges support the theory that Yeni Rabat Church could have been constructed in medieval times.

Prevalence and risk factors of fatty liver disease in the Shuiguohu district of Wuhan city, central China

PubMed Central

Wang, Zhongli; Xia, Bing; Ma, Chunwei; Hu, Zhengguo; Chen, Xiangqun; Cao, Ping

2007-01-01

Background Fatty liver disease (FLD) is highly prevalent in Western countries, but recent data have shown that FLD is also emerging in China. Aim To investigate the prevalence and risk factors of FLD in the Shuiguohu district of Wuhan city, central China, during 1995–2004. Methods 12247 individuals (7179 men and 5068 women) over 18 years of age who were living in the area were investigated for FLD in the Zhongnan Hospital of Wuhan University from 1995 to 2004. FLD was determined by the ultrasonographic method. Height, weight, blood pressure, fasting blood sugar, alanine aminotransferase, total cholesterol and triglyceride were determined by routine laboratory methods. Results The prevalence of FLD was 12.5% in 1995, and rose gradually to 24.5% by 2003–4. The prevalence was twice as high in men (28.1%) as in women (13.8%), and increased with age in females, and males <60 years of age. Multivariate analysis showed that several risk factors were profoundly associated with the prevalence of FLD, including male sex, old age, obesity, hyperlipidaemia (cholesterol or triglyceride), fasting hyperglycemia and hypertension. Conclusion The prevalence of FLD in the Shuiguohu district of Wuhan city, central China, was shown to have increased during the 10‐year period, 1995 to 2004. The FLD was found to be closely associated with sex, age, obesity and other metabolic syndrome features. PMID:17344575

Age-class separation of blue-winged ducks

USGS Publications Warehouse

Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.

1995-01-01

Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual and flyway differences in remigial measurements and reduced performance of age classification models as evidence of high variability in size of blue-winged ducks' remiges. Variability in remigial size of these and other small-bodied waterfowl may be related to nutrition during molt.

Effects of Mastery Learning Strategies on Community College Mathematics Students' Achievement and Success Rate.

ERIC Educational Resources Information Center

Abadir, Laila; And Others

The effects of mastery learning strategies, interactive video mathematics (IVM), individualized instruction (IND), and the lecture method on mathematics achievement of community college students was studied. Interactions among instructional methods, gender, and age were examined; and the grade success rate was determined for each instructional…

Comparison of two viewing methods for estimating largemouth bass and walleye ages from sectioned otoliths and dorsal spines

USGS Publications Warehouse

Wegleitner, Eric J.; Isermann, Daniel A.

2017-01-01

Many biologists use digital images for estimating ages of fish, but the use of images could lead to differences in age estimates and precision because image capture can produce changes in light and clarity compared to directly viewing structures through a microscope. We used sectioned sagittal otoliths from 132 Largemouth Bass Micropterus salmoides and sectioned dorsal spines and otoliths from 157 Walleyes Sander vitreus to determine whether age estimates and among‐reader precision were similar when annuli were enumerated directly through a microscope or from digital images. Agreement of ages between viewing methods for three readers were highest for Largemouth Bass otoliths (75–89% among readers), followed by Walleye otoliths (63–70%) and Walleye dorsal spines (47–64%). Most discrepancies (72–96%) were ±1 year, and differences were more prevalent for age‐5 and older fish. With few exceptions, mean ages estimated from digital images were similar to ages estimated via directly viewing the structures through the microscope, and among‐reader precision did not vary between viewing methods for each structure. However, the number of disagreements we observed suggests that biologists should assess potential differences in age structure that could arise if images of calcified structures are used in the age estimation process.

Overlap between age-at-onset and disease-progression determinants in Huntington disease.

PubMed

Aziz, N Ahmad; van der Burg, Jorien M M; Tabrizi, Sarah J; Landwehrmeyer, G Bernhard

2018-05-09

A fundamental but still unresolved issue regarding Huntington disease (HD) pathogenesis is whether the factors that determine age at onset are the same as those that govern disease progression. Because elucidation of this issue is crucial for the development as well as optimal timing of administration of novel disease-modifying therapies, we aimed to assess the extent of overlap between age-at-onset and disease-progression determinants in HD. Using observational data from Enroll-HD, the largest cohort of patients with HD worldwide, in this study we present, validate, and apply an intuitive method based on linear mixed-effect models to quantify the variability in the rate of disease progression in HD. A total of 3,411 patients with HD met inclusion criteria. We found that (1) about two-thirds of the rate of functional, motor, and cognitive progression in HD is determined by the same factors that also determine age at onset, with CAG repeat-dependent mechanisms having by far the largest effect; (2) although expanded HTT CAG repeat size had a large influence on average body weight, the rate of weight loss was largely independent of factors that determine age at onset in HD; and (3) about one-third of the factors that determine the rate of functional, motor, and cognitive progression are different from those that govern age at onset and need further elucidation. Our findings imply that targeting of CAG repeat-dependent mechanisms, for example through gene-silencing approaches, is likely to affect the rate of functional, motor, and cognitive impairment, but not weight loss, in manifest HD mutation carriers. Copyright © 2018 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population.

PubMed

Sequeira, Catarina-Dourado; Teixeira, Alexandra; Caldas, Inês-Morais; Afonso, Américo; Pérez-Mongiovi, Daniel

2014-12-01

The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament.

Calcaneal quantitative ultrasound value for middle-aged and elderly Malaysian Chinese men and its association with age and body anthropometry.

PubMed

Chin, Kok-Yong; Ima-Nirwana, Soelaiman; Isa Naina, Mohamed; Norazlina, Mohamed; Ahmad Nazrun, Shuid; Norliza, Muhammad; Faizah, Othman; Farihah, H Suhaimi; Elvy Suhana, Mohd Ramli; Wan Zurinah, Wan Ngah

2012-01-01

Quantitative ultrasound (QUS) is a relatively easy, reliable, and safe method for bone status assessment, but reference data for Asian males remain scarce. Our study aimed to determine the values for one QUS parameter, the speed of sound (SOS) at the calcaneus, in Malaysian Chinese men and to determine the association between the SOS and several demographic characteristics, such as age, weight, height, and body mass index. Three hundred forty-eight Malaysian Chinese men aged 40 yr and older were recruited, and their calcaneal QUS value was determined using the CM-200 densitometer (Furuno Electric, Nishinomiya City, Japan). The results indicated a significant correlation between SOS and age, and multiple stepwise regression analysis indicated that age and height were important predictors of SOS. A significant reduction in SOS value was observed when men 60 yr and older were compared with men aged 40-49 yr. Compared with the reference data for Japanese males, Chinese men in Malaysia showed higher SOS values across all the age groups studied. In conclusion, there is an age-related decrease in SOS values in Malaysian Chinese men, and the SOS values established in this study can be used as a reference for future studies. Copyright © 2012 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Socioeconomic and Reproductive Determinants of Waist-Hip Ratio Index in Menopausal Women

PubMed Central

Rastegari, Zahra; Noroozi, Mahnaz; Paknahad, Zamzam

2017-01-01

Background: Health evaluation is carried out using various anthropometric methods including waist–hip ratio (WHR) index. This method is applied for estimating body fat distribution. This study was aimed to investigate the socioeconomic and reproductive determinants of WHR index in menopausal women. Materials and Methods: For this cross-sectional study, samples were 278 menopausal women in Isfahan, Iran, who were selected by stratified sampling and invited to ten health centers. The data collection tools were a questionnaire and the standard meter tape. Data were analyzed using descriptive and inferential statistical tests. Results: The mean of WHR index was X̄ = 0.9 ± 7.54. There was a significantly statistical relation between age, job, educational status, number of pregnancies and deliveries, age of the first delivery, and WHR index. Conclusion: Based on the results, body fat distribution of menopausal women is of android (central) type. It is suggested that measuring WHR index should be done in menopausal women and also during the postpartum period in specific intervals. Furthermore, women should be familiarized with related factors to this index, and it is recommended to avoid pregnancy and delivery at early ages and repeated pregnancies. PMID:29307978

A double-spike method for K-Ar measurement: A technique for high precision in situ dating on Mars and other planetary surfaces

NASA Astrophysics Data System (ADS)

Farley, K. A.; Hurowitz, J. A.; Asimow, P. D.; Jacobson, N. S.; Cartwright, J. A.

2013-06-01

A new method for K-Ar dating using a double isotope dilution technique is proposed and demonstrated. The method is designed to eliminate known difficulties facing in situ dating on planetary surfaces, especially instrument complexity and power availability. It may also have applicability in some terrestrial dating applications. Key to the method is the use of a solid tracer spike enriched in both 39Ar and 41K. When mixed with lithium borate flux in a Knudsen effusion cell, this tracer spike and a sample to be dated can be successfully fused and degassed of Ar at <1000 °C. The evolved 40Ar∗/39Ar ratio can be measured to high precision using noble gas mass spectrometry. After argon measurement the sample melt is heated to a slightly higher temperature (˜1030 °C) to volatilize potassium, and the evolved 39K/41K ratio measured by Knudsen effusion mass spectrometry. Combined with the known composition of the tracer spike, these two ratios define the K-Ar age using a single sample aliquot and without the need for extreme temperature or a mass determination. In principle the method can be implemented using a single mass spectrometer. Experiments indicate that quantitative extraction of argon from a basalt sample occurs at a sufficiently low temperature that potassium loss in this step is unimportant. Similarly, potassium isotope ratios measured in the Knudsen apparatus indicate good sample-spike equilibration and acceptably small isotopic fractionation. When applied to a flood basalt from the Viluy Traps, Siberia, a K-Ar age of 351 ± 19 Ma was obtained, a result within 1% of the independently known age. For practical reasons this measurement was made on two separate mass spectrometers, but a scheme for combining the measurements in a single analytical instrument is described. Because both parent and daughter are determined by isotope dilution, the precision on K-Ar ages obtained by the double isotope dilution method should routinely approach that of a pair of isotope ratio determinations, likely better than ±5%.

24 CFR 960.253 - Choice of rent.

Code of Federal Regulations, 2010 CFR

2010-04-01

... determine the flat rent, the PHA must consider: (i) The location, quality, size, unit type and age of the... options—(1) Annual choice by family. Once a year, the PHA must give each family the opportunity to choose between the two methods for determining the amount of tenant rent payable monthly by the family. The...

Not Just the Taste: Why Adolescents Drink Alcopops

ERIC Educational Resources Information Center

Jones, Sandra C.; Reis, Samantha

2012-01-01

Purpose: The purpose of this paper is to determine the features of alcopops which make them attractive to Australian adolescents, which features are most important in determining choice of ready-to-drinks (RTDs) over other alcoholic drinks, and whether these vary by age and gender. Design/methodology/approach: Mixed methods study. Participants in…

Determination of Factors Effected Dietary Glycemic Index in Turkish University Students

ERIC Educational Resources Information Center

Gumus, Huseyin; Akdevelioglu, Yasemin; Bulduk, Sidika

2014-01-01

We aimed to determine how factors such as smoking, regular activity, etc. affected dietary glycemic index in university students. Methods: This study was carried out at Gazi University, Ankara, Turkey. The participants were 577 randomly selected Turkish healthy female university students aged 17-32 years. The survey included a questionnaire that…

Lifecourse Activity Participation From Early, Mid, and Later Adulthood as Determinants of Cognitive Aging: The Lothian Birth Cohort 1921

PubMed Central

Pattie, Alison; Deary, Ian J.

2017-01-01

Objectives: To examine potential sensitive periods for activity participation across adulthood to reduce cognitive decline and to determine whether associations persist after accounting for the lifetime stability of cognitive ability. Method: The Lothian Birth Cohort 1921 is a longitudinal study of cognitive aging. Participants were born in 1921 and most completed a mental ability test at the age of 11 years. Cognitive assessments were completed at mean ages 79 (N = 550), 83 (N = 321), 87 (N = 235), and 90 years (N = 129). Participants provided retrospective details of their activity participation for young (20–35 years), mid (40–55 years), and later adulthood (60–75 years), and contemporaneously at age 79. Results: Associations between activity and the level of, and change in, cognitive ability in old age were examined with latent growth curve models. Accounting for demographics and childhood cognitive ability, engagement in leisure activities in midlife was positively associated with cognitive ability level (path coefficient = .32), whereas higher physical activity in later adulthood was associated with less cognitive decline (.27). Discussion: The findings support a lifecourse approach in identifying determinants of cognitive aging; leisure and physical activity during different periods of adulthood may enhance cognitive abilities or reduce decline. PMID:27974473

Age and growth of the brick soldierfish, Myripristis amaena

NASA Astrophysics Data System (ADS)

Dee, Anderson J.; Radtke, Richard L.

1989-09-01

Otoliths (sagittae) of the coral reef fish, Myripristis amaena, the brick solderfish were examined internally by Scanning Electron Microscope methods to observe microincrements. The daily nature of increment deposition was validated through tetracycline and acetazolamide marking experiments. Utilization of multivariant mathematical models relating age to otolith size and fish size demonstrated that age could be reliably determined from body measurements and otolith weight measurements. Consequently, M. amaena grows slowly, maturing at about 6 years of age, lives at least 14 years and reaches at least 215 mm SL.

Child Weight Growth Trajectory and its Determinants in a Sample of Iranian Children from Birth until 2 Years of Age

PubMed Central

Hosseini, Sayed-Mohsen; Maracy, Mohamad-Reza; Sarrafzade, Sheida; Kelishadi, Roya

2014-01-01

Background: Growth is one of the most important indices in child health. The best and most effective way to investigate child health is measuring the physical growth indices such as weight, height and head circumference. Among these measures, weight growth is the simplest and the most effective way to determine child growth status. Weight trend at a given age is the result of cumulative growth experience, whereas growth velocity represents what is happening at the time. Methods: This longitudinal study was conducted among 606 children repeatedly measured from birth until 2 years of age. We used linear mixed model to analyze repeated measures and to determine factors affecting the growth trajectory. LOWESS smooth curve was used to draw velocity curves. Results: Gender, child rank, birth status and feeding mode had a significant effect on weight trajectory. Boys had higher weight during the study. Infants with exclusive breast feeding had higher weight than other infants. Boys had higher growth velocity up to age 6 month. Breast fed infants had higher growth velocity up to 6 month, but thereafter the velocity was higher in other infants. Conclusions: Many of the studies have investigated child growth, but most of them used cross-sectional design. In this study, we used longitudinal method to determine effective factors on weight trend in children from birth until 2-year-old. The effects of perinatal factors on further growth should be considered for prevention of growth disorders and their late complications. PMID:24829720

Ultrasonic Technique for Predicting Grittiness of Salted Duck Egg

NASA Astrophysics Data System (ADS)

Erawan, S.; Budiastra, I. W.; Subrata, I. D. M.

2018-05-01

Grittiness of egg yolk is a major factor in consumer acceptance of salted duck egg product. Commonly, the grittiness level is determined by the destructive method. Salted egg industries need a grading system that can judge the grittiness accurately and nondestructively. The purpose of this study was to develop a method for determining grittiness of salted duck eggs nondestructively based on ultrasonic method. This study used 100 samples of salted duck eggs with 7,10,14 and 21 days of salting age. Velocity and attenuation were measured by an ultrasonic system at frequency 50 kHz, followed by physicochemical properties measurement (hardness of egg yolks and salt content), and organoleptic test. Ultrasonic wave velocity in salted duck eggs ranged from 620.6 m/s to 1334.6 m/s, while the coefficient of attenuation value ranged from – 0.76 dB/m to -0.51 dB/m. Yolk hardness was 2.68 N at 7 days to 5.54 N at 21 days of salting age. Salt content was 1.81 % at 7 days to 5.71 % at 21 days of salting age. Highest scores of organoleptic tests on salted duck eggs were 4.23 and 4.18 for 10 and 14 days of salting age, respectively. Discriminant function using ultrasonic velocity variables in minor and major diameter could predict grittiness with 95 % accuracy.

The Influence of the Manner of Performing the Thyroid Ultrasound Examination on the Reliability of the Assessment of the Thyroid Size in School-Aged Children.

PubMed

Zygmunt, Arkadiusz; Adamczewski, Zbigniew; Zygmunt, Agnieszka; Karbownik-Lewinska, Malgorzata; Lewinski, Andrzej

2017-01-01

Goitre incidence in school-aged children evaluated using ultrasonography is one of the essential indicators of iodine intake in a given area. The aim of the study was to examine what the difference is between the volume of the thyroid gland measured in the supine and sitting position and to determine the intra-observer, inter-observer, and inter-position variations. The survey was conducted among 87 children (56 girls and 31 boys aged 7-13 years, mean age 10.44 ± 1.72 years). The thyroid volume measured in a sitting position was significantly lower than that measured in the supine position. The intra-observer variations for the total thyroid volume equalled 9.56-9.65%. The inter-observer variations were significantly higher and amounted to 34.5-35.7%. The way in which ultrasound evaluation is performed is important for the analysis of the results. It is crucial to aim for the smallest inter-observer variation, which can be achieved by strictly defining the methods of the thyroid measurement and comparing one's measuring techniques with the reference method. The use of standards in ultrasound evaluation performed in the supine position, as well as the use of standards without a strict determination of the study method, can lead to erro-neous conclusions. © 2017 S. Karger AG, Basel.

Activities of daily living, instrumental activities for daily living and predictors of functional capacity of older men in Jamaica

PubMed Central

Bourne, Paul Andrew

2009-01-01

Background: An extensive search of the literature found no studies that have examined functional capacity [Activities of Daily Living (ADL) and Instrumental Activities for Daily Living (I) ADL)] of Jamaican older men as well as factors that determine their functional capacity. Aims: The current study examines 1) ADL, 2) (I) ADL), 3) self-reported health status, 4) functional capacity, and 5) factors that determine functional capacity of older men. Methods and Method: Stratified multistage probability sampling technique was used to draw a sample of 2,000 55+ year men. A132-item questionnaire was used to collect the data. Descriptive statistics provide background information on the sample, cross tabulations were used to examine non-metric variables and logistic regression provides a model of predictors of functional capacity. Result: Fifty-five percent of sample indicated good current health status. Four percent was mostly satisfied with life; 21.7% had moderate dependence; 77.1% had high dependence (i.e. independence); 1.2% had low dependence; 21.9% were ages 75 years and older; 35.6% were ages 65 to 74 years and 42.6% reported ages 55 to 64 years. Functional capacity can be determined by church attendance (β=0.245; 95% CI: 0.264, 1.291); social support (β=0.129; 95% CI: 0.129, 0.258), area of residence (β=-0.060; 95% CI: -0.427, -0.061) and lastly by age of respondents. Conclusion: Ageing in explains deterioration in their (I) ADL, suggesting the challenges of ageing men's independence. More rural men were rarely satisfied with life; but more of them had a greater functional capacity than urban men. Depression was found to negatively relate to functional capacity, and church attendees had a greater functional status than non-attendees. PMID:22666693

Determination of 17OHPreg and DHEAS by LC-MS/MS: Impact of Age, Sex, Pubertal Stage, and BMI on the Δ5 Steroid Pathway.

PubMed

Kulle, Alexandra E; Reinehr, Thomas; Simic-Schleicher, Gunter; Hornig, Nadine C; Holterhus, Paul-Martin

2017-01-01

Dehydroepiandrosterone sulfate (DHEAS) and 17-hydroxypregnenolone (17OHPreg) are important for understanding the Δ5 pathway (e.g., in adrenarche and obesity). Although mass spectrometry has become the state-of-the-art method for quantifying steroids, there are few comprehensive age-, sex-, and pubertal stage-specific reference ranges for children. To develop a sensitive and reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for simultaneous quantification of DHEAS and 17OHPreg and to establish entire age-, sex- and pubertal stage-specific reference ranges in children. A total of 684 children, 453 (243 female, 210 male) with normal body mass index (BMI; <90th) and 231 (132 female, 99 male) obese subjects (>97th), were categorized into 11 age groups, and age- and Tanner stage (PH)-specific reference ranges were determined. The limit of detection was 0.05 nmol/L for 17OHPreg and 0.5 nmol/L for DHEAS. Levels of both steroids declined after the neonatal period. Comparisons with RIA assays (Siemens, Munich, Germany) (DHEAS) and an in-house kit (17OHPreg) revealed 0.95 and 0.93, respectively, as coefficients of determination. Although DHEAS-generally higher in boys-increased continuously starting at 3 to 6 years, 17OHPreg remained largely constant. In obese patients, both were significantly elevated, also in part after alignment to Tanner stages (PH). UPLC-MS/MS is sensitive and reliable for quantifying DHEAS and 17OHPreg. Our data support differential maturation of CYP17 during adrenarche with successively increasing 17,20-lyase activity but largely constant 17α-hydroxylation activity. Endocrine interpretation of 17OHPreg and DHEAS must consider differential patterns for age, sex, pubertal stage, and BMI. Copyright © 2017 by the Endocrine Society

Simultaneous Quantitation of Advanced Glycation End Products in Soy Sauce and Beer by Liquid Chromatography-Tandem Mass Spectrometry without Ion-Pair Reagents and Derivatization.

PubMed

Nomi, Yuri; Annaka, Hironori; Sato, Shinji; Ueta, Etsuko; Ohkura, Tsuyoshi; Yamamoto, Kazuhiro; Homma, Seiichi; Suzuki, Emiko; Otsuka, Yuzuru

2016-11-09

The aim of this study was to develop a simple and sensitive method to analyze several advanced glycation end products (AGEs) simultaneously using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and to apply this method to the quantitation of AGEs in brown-colored foods. The developed method enabled to separate and quantitate simultaneously seven AGEs, and was applied to the determination of free AGEs contained in various kinds of soy sauce and beer. The major AGEs in soy sauce and beer were N ε -carboxymethyllysine (CML), N ε -carboxyethyllysine (CEL), and N δ -(5-hydro-5-methyl-4-imidazolon-2-yl)ornithine (MG-H1). Using the developed LC-MS/MS method, recovery test on soy sauce and beer samples showed the recovery values of 85.3-103.9% for CML, 95.9-107.4% for CEL, and 69.5-123.2% for MG-H1. In particular, it is the first report that free CML, CEL, and MG-H1 were present in beer. Furthermore, long-term storage and heating process of soy sauce increased CML and MG-H1.

Time evolution of high-energy emissions of low-mass stars. I. Age determination using stellar chronology with white dwarfs in wide binaries

NASA Astrophysics Data System (ADS)

Garcés, A.; Catalán, S.; Ribas, I.

2011-07-01

Context. Stellar ages are extremely difficult to determine and often subject to large uncertainties, especially for field low-mass stars. We plan to carry out a calibration of the decrease in high-energy emissions of low-mass GKM stars with time, and therefore precise age determination is a key ingredient. The overall goal of our research is to study the time evolution of these high-energy emissions as an essential input to studying exoplanetary atmospheres. Aims: We propose to determine stellar ages with a methodology based on wide binaries. We are interested in systems composed of a low-mass star and a white dwarf (WD), where the latter serves as a stellar chronometer for the system. We aim at obtaining reliable ages for a sample of late-type stars older than 1 Gyr. Methods: We selected a sample of wide binaries composed by a DA type WD and a GKM companion. High signal-to-noise, low-resolution spectroscopic observations were obtained for most of the WD members of the sample. Atmospheric parameters were determined by fitting the spectroscopic data to appropiate WD models. The total ages of the systems were derived by using cooling sequences, an initial-final mass relationship and evolutionary tracks, to account for the progenitor life. Results: The spectroscopic observations have allowed us to determine ages for the binary systems using WDs as cosmochronometers. We obtained reliable ages for 27 stars between 1 and 5 Gyr, which is a range where age determination becomes difficult for field objects. Roughly half of these systems have cooling ages that contribute at least 30% the total age. We select those for further study since their age estimate should be less prone to systematic errors coming from the initial-final mass relationship. Conclusions: We have determined robust ages for a sizeable sample of GKM stars that can be subsequently used to study the time evolution of their emissions associated to stellar magnetic activity. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).Based on observations made with the WHT (William Herschel Telescope) operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

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

NASA Astrophysics Data System (ADS)

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).

Adequacy of Using a Three-Item Questionnaire to Determine Zygosity in Chinese Young Twins.

PubMed

Ho, Connie Suk-Han; Zheng, Mo; Chow, Bonnie Wing-Yin; Wong, Simpson W L; Lim, Cadmon K P; Waye, Mary M Y

2017-03-01

The present study examined the adequacy of a three-item parent questionnaire in determining the zygosity of young Chinese twins and whether there was any association between parent response accuracy and some demographic variables. The sample consisted of 334 pairs of same-sex Chinese twins aged from 3 to 11 years. Three scoring methods, namely the summed score, logistic regression, and decision tree, were employed to evaluate parent response accuracy of twin zygosity based on single nucleotide polymorphism (SNP) information. The results showed that all three methods achieved high level of accuracy ranging from 91 to 93 % which was comparable to the accuracy rates in previous Chinese twin studies. Correlation results also showed that the higher the parents' education level or the family income was, the more likely parents were able to tell correctly that their twins are identical or fraternal. The present findings confirmed the validity of using a three-item parent questionnaire to determine twin zygosity in a Chinese school-aged twin sample.

Evidence that a Motor Timing Deficit Is a Factor in the Development of Stuttering

ERIC Educational Resources Information Center

Olander, Lindsey; Smith, Anne; Zelaznik, Howard N.

2010-01-01

Purpose: To determine whether young children who stutter have a basic motor timing and/or a coordination deficit. Method: Between-hands coordination and variability of rhythmic motor timing were assessed in 17 children who stutter (4-6 years of age) and 13 age-matched controls. Children clapped in rhythm with a metronome with a 600-ms interbeat…

Neighborhood Density and Syntactic Class Effects on Spoken Word Recognition: Specific Language Impairment and Typical Development

ERIC Educational Resources Information Center

Hoover, Jill R.

2018-01-01

Purpose: The purpose of the current study was to determine the effect of neighborhood density and syntactic class on word recognition in children with specific language impairment (SLI) and typical development (TD). Method: Fifteen children with SLI ("M" age = 6;5 [years;months]) and 15 with TD ("M" age = 6;4) completed a…

Age at Menarche and Premenstrual Syndrome in Adolescent Girls with Intellectual Disability in Bosnia and Herzegovina

ERIC Educational Resources Information Center

Ibralic, Inga; Sinanovic, Osman; Memisevic, Haris

2010-01-01

The issues involving menstruation are the topic of many scientific inquires in the fields of medicine, psychology, sociology and anthropology. The aim of this study was to determine the age at menarche and the most common symptoms of premenstrual syndrome (PMS) in adolescent girls with intellectual disability. The main method of data collection…

Internationally Adopted Children in the Early School Years: Relative Strengths and Weaknesses in Language Abilities

ERIC Educational Resources Information Center

Glennen, Sharon

2015-01-01

Purpose: This study aimed to determine the relative strengths and weaknesses in language and verbal short-term memory abilities of school-age children who were adopted from Eastern Europe. Method: Children adopted between 1;0 and 4;11 (years;months) of age were assessed with the Clinical Evaluation of Language Fundamentals-Preschool, Second…

Prevalence of Hearing Loss in Black and White Elders: Results of the Cardiovascular Health Study

ERIC Educational Resources Information Center

Pratt, Sheila R.; Kuller, Lewis; Talbott, Evelyn O.; McHugh-Pemu, Kathleen; Buhari, Alhaji M.; Xu, Xiaohui

2009-01-01

Purpose: The goal of this study was to determine the impact of age, gender, and race on the prevalence and severity of hearing loss in elder adults, aged 72-96 years, after accounting for income, education, smoking, and clinical and subclinical cardiovascular disease. Methods: Air-conduction thresholds for standard and extended high-frequency…

Do Healthy Preterm Children Need Neuropsychological Follow-Up? Preschool Outcomes Compared with Term Peers

ERIC Educational Resources Information Center

Dall'Oglio, Anna M.; Rossiello, Barbara; Coletti, Maria F.; Bultrini, Massimiliano; De Marchis, Chiara; Rava, Lucilla; Caselli, Cristina; Paris, Silvana; Cuttini, Marina

2010-01-01

Aim: The aim of this study was to determine neuropsychological performance (possibly predictive of academic difficulties) and its relationship with cognitive development and maternal education in healthy preterm children of preschool age and age-matched comparison children born at term. Method : A total of 35 infants who were born at less than 33…

The Speech Intelligibility Index and the Pure-Tone Average as Predictors of Lexical Ability in Children Fit with Hearing Aids

ERIC Educational Resources Information Center

Stiles, Derek J.; Bentler, Ruth A.; McGregor, Karla K.

2012-01-01

Purpose: To determine whether a clinically obtainable measure of audibility, the aided Speech Intelligibility Index (SII; American National Standards Institute, 2007), is more sensitive than the pure-tone average (PTA) at predicting the lexical abilities of children who wear hearing aids (CHA). Method: School-age CHA and age-matched children with…

Survey Results for Participating Colleges: Classes and Programs for the Aged in the California Community Colleges, 1978.

ERIC Educational Resources Information Center

Charles, Richard F.

The 106 community colleges in California were surveyed by questionnaire to determine their current level of commitment to the aged in terms of programs and courses available, adult participation, and methods used to conduct programs. Eighty-three questionnaires (78%) were returned. Of the responding colleges, 43% were currently offering classes or…

Reprint of "Cortical Reorganization of Language Functioning Following Perinatal Left MCA Stroke" [Brain and Language 105 (2008) 99-111

ERIC Educational Resources Information Center

Tillema, Jan-Mendelt; Byars, Anna W.; Jacola, Lisa M.; Schapiro, Mark B.; Schmithorst, Vince J.; Szaflarski, Jerzy P.; Holland, Scott K.

2008-01-01

Objective: Functional MRI was used to determine differences in patterns of cortical activation between children who suffered perinatal left middle cerebral artery (MCA) stroke and healthy children performing a silent verb generation task. Methods: Ten children with prior perinatal left MCA stroke (age 6-16 years) and ten healthy age matched…

Smoking-attributable medical expenditures by age, sex, and smoking status estimated using a relative risk approach☆

PubMed Central

Maciosek, Michael V.; Xu, Xin; Butani, Amy L.; Pechacek, Terry F.

2015-01-01

Objective To accurately assess the benefits of tobacco control interventions and to better inform decision makers, knowledge of medical expenditures by age, gender, and smoking status is essential. Method We propose an approach to distribute smoking-attributable expenditures by age, gender, and cigarette smoking status to reflect the known risks of smoking. We distribute hospitalization days for smoking-attributable diseases according to relative risks of smoking-attributable mortality, and use the method to determine national estimates of smoking-attributable expenditures by age, sex, and cigarette smoking status. Sensitivity analyses explored assumptions of the method. Results Both current and former smokers ages 75 and over have about 12 times the smoking-attributable expenditures of their current and former smoker counterparts 35–54 years of age. Within each age group, the expenditures of formers smokers are about 70% lower than current smokers. In sensitivity analysis, these results were not robust to large changes to the relative risks of smoking-attributable mortality which were used in the calculations. Conclusion Sex- and age-group-specific smoking expenditures reflect observed disease risk differences between current and former cigarette smokers and indicate that about 70% of current smokers’ excess medical care costs is preventable by quitting. PMID:26051203

Setting the light conditions for measuring root transparency for age-at-death estimation methods.

PubMed

Adserias-Garriga, Joe; Nogué-Navarro, Laia; Zapico, Sara C; Ubelaker, Douglas H

2018-03-01

Age-at-death estimation is one of the main goals in forensic identification, being an essential parameter to determine the biological profile, narrowing the possibility of identification in cases involving missing persons and unidentified bodies. The study of dental tissues has been long considered as a proper tool for age estimation with several age estimation methods based on them. Dental age estimation methods can be divided into three categories: tooth formation and development, post-formation changes, and histological changes. While tooth formation and growth changes are important for fetal and infant consideration, when the end of dental and skeletal growth is achieved, post-formation or biochemical changes can be applied. Lamendin et al. in J Forensic Sci 37:1373-1379, (1992) developed an adult age estimation method based on root transparency and periodontal recession. The regression formula demonstrated its accuracy of use for 40 to 70-year-old individuals. Later on, Prince and Ubelaker in J Forensic Sci 47(1):107-116, (2002) evaluated the effects of ancestry and sex and incorporated root height into the equation, developing four new regression formulas for males and females of African and European ancestry. Even though root transparency is a key element in the method, the conditions for measuring this element have not been established. The aim of the present study is to set the light conditions measured in lumens that offer greater accuracy when applying the Lamendin et al. method modified by Prince and Ubelaker. The results must be also taken into account in the application of other age estimation methodologies using root transparency to estimate age-at-death.

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

PubMed Central

Mohammed, Rezwana Begum; Koganti, Ravichandra; Kalyan, Siva V.; Tircouveluri, Saritha; Singh, Johar Rajvinder; Srinivasulu, Enganti

2014-01-01

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. PMID:25177143

Dental age estimation employing CBCT scans enhanced with Mimics software: Comparison of two different approaches using pulp/tooth volumetric analysis.

PubMed

Asif, Muhammad Khan; Nambiar, Phrabhakaran; Mani, Shani Ann; Ibrahim, Norliza Binti; Khan, Iqra Muhammad; Sukumaran, Prema

2018-02-01

The methods of dental age estimation and identification of unknown deceased individuals are evolving with the introduction of advanced innovative imaging technologies in forensic investigations. However, assessing small structures like root canal volumes can be challenging in spite of using highly advanced technology. The aim of the study was to investigate which amongst the two methods of volumetric analysis of maxillary central incisors displayed higher strength of correlation between chronological age and pulp/tooth volume ratio for Malaysian adults. Volumetric analysis of pulp cavity/tooth ratio was employed in Method 1 and pulp chamber/crown ratio (up to cemento-enamel junction) was analysed in Method 2. The images were acquired employing CBCT scans and enhanced by manipulating them with the Mimics software. These scans belonged to 56 males and 54 females and their ages ranged from 16 to 65 years. Pearson correlation and regression analysis indicated that both methods used for volumetric measurements had strong correlation between chronological age and pulp/tooth volume ratio. However, Method 2 gave higher coefficient of determination value (R2 = 0.78) when compared to Method 1 (R2 = 0.64). Moreover, manipulation in Method 2 was less time consuming and revealed higher inter-examiner reliability (0.982) as no manual intervention during 'multiple slice editing phase' of the software was required. In conclusion, this study showed that volumetric analysis of pulp cavity/tooth ratio is a valuable gender independent technique and the Method 2 regression equation should be recommended for dental age estimation. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Slab replacement maturity guidelines.

DOT National Transportation Integrated Search

2014-04-01

This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

Comparative effect of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction on antioxidant enzymes activity in cellular ageing of human diploid fibroblasts

PubMed Central

2013-01-01

Background Human diploid fibroblasts (HDFs) undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular ageing. Even though beneficial effects of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction (TRF) have been reported, ongoing studies in relation to ageing is of interest to determine possible protective effects that may reverse the effect of ageing. The aim of this study was to evaluate the effect of P. betle, C. vulgaris and TRF in preventing cellular ageing of HDFs by determining the activity of antioxidant enzymes viz.; catalase, superoxide dismutase (SOD) and glutathione peroxidase. Methods Different passages of HDFs were treated with P. betle, C. vulgaris and TRF for 24 h prior to enzymes activity determination. Senescence-associated beta-galactosidase (SA β-gal) expression was assayed to validate cellular ageing. Results In cellular ageing of HDFs, catalase and glutathione peroxidase activities were reduced, but SOD activity was heightened during pre-senescence. P. betle exhibited the strongest antioxidant activity by reducing SA β-gal expression, catalase activities in all age groups, and SOD activity. TRF exhibited a strong antioxidant activity by reducing SA β-gal expression, and SOD activity in senescent HDFs. C. vulgaris extract managed to reduce SOD activity in senescent HDFs. Conclusion P. betle, C. vulgaris, and TRF have the potential as anti-ageing entities which compensated the role of antioxidant enzymes in cellular ageing of HDFs. PMID:23948056

Age determination enhanced by embryonic foot bud and foot plate measurements in relation to Carnegie stages, and the influence of maternal cigarette smoking.

PubMed

Lutterodt, M C; Rosendahl, M; Yding Andersen, C; Skouby, S O; Byskov, A G

2009-08-01

Reliable age determination of first-trimester human embryos and fetuses is an important parameter for clinical use and basic science. Age determination by ultrasound or morphometric parameters of embryos 4-6 weeks post conception (p.c.) have been questioned, and more accurate methods are required. Data on whether and how maternal smoking and alcohol consumption influence embryonic and fetal foot growth is also lacking. Embryonic tissue from 102 first-trimester legal abortions (aged 35-69 days p.c.) were collected. All women answered a questionnaire concerning smoking and drinking habits, and delivered a urine sample for cotinine analysis. Embryonic age was evaluated by vaginal ultrasound measurements and by post-termination foot length and compared with the Carnegie stages. Foot bud and foot plate were defined and measured as foot length in embryos aged 35-47 days p.c. (range 0.8-2.1 mm). In embryos and fetuses aged 41-69 days p.c., heel-toe length was measured (range 2.5-7.5 mm). We found a significant linear correlation between foot length and age. Morphology of the feet was compared visually with the Carnegie collection, and we found that the mean ages of the two collections correlated well. Foot length was independent of gender, Environmental Tobacco Smoke, maternal smoking and alcohol consumption. Foot length correlated linearly to embryonic and foetal age, and was unaffected by gender, ETS, maternal smoking and alcohol consumption.

The Stayhealthy bioelectrical impedance analyzer predicts body fat in children and adults.

PubMed

Erceg, David N; Dieli-Conwright, Christina M; Rossuello, Amerigo E; Jensky, Nicole E; Sun, Stephanie; Schroeder, E Todd

2010-05-01

Bioelectrical impedance analysis (BIA) is a time-efficient and cost-effective method for estimating body composition. We hypothesized that there would be no significant difference between the Stayhealthy BC1 BIA and the selected reference methods when determining body composition. Thus, the purpose of the present study was to determine the validity of estimating percent body fat (%BF) using the Stayhealthy BIA with its most recently updated algorithms compared to the reference methods of dual-energy x-ray absorptiometry for adults and hydrostatic weighing for children. We measured %BF in 245 adults aged 18 to 80 years and 115 children aged 10 to 17 years. Body fat by BIA was determined using a single 50 kHz frequency handheld impedance device and proprietary software. Agreement between BIA and reference methods was assessed by Bland and Altman plots. Bland and Altman analysis for men, women, and children revealed good agreement between the reference methods and BIA. There was no significant difference by t tests between mean %BF by BIA for men, women, or children when compared to the respective reference method. Significant correlation values between BIA, and reference methods for all men, women, and children were 0.85, 0.88, and 0.79, respectively. Reliability (test-retest) was assessed by intraclass correlation coefficient and coefficient of variation. Intraclass correlation coefficient values were greater than 0.99 (P < .001) for men, women, and children with coefficient of variation values 3.3%, 1.8%, and 1.7%, respectively. The Stayhealthy BIA device demonstrated good agreement between reference methods using Bland and Altman analyses. Copyright 2010 Elsevier Inc. All rights reserved.

Relationship between Body Mass Index, Skeletal Maturation and Dental Development in 6- to 15- Year Old Orthodontic Patients in a Sample of Iranian Population.

PubMed

Hedayati, Zohreh; Khalafinejad, Fatemeh

2014-12-01

The prevalence of overweight and obesity has been increasing markedly in recent years. It may influence growth in pre pubertal children. The purpose of this study was to determine whether increased Body Mass Index (BMI) is associated with accelerated skeletal maturation and dental maturation in six to fifteen years old orthodontic patients in Shiraz, Iran. Skeletal maturation and dental development of 95 orthodontic patients (65 females and 30 males), aged 6 to 15 years, were determined. Dental development was assessed using the Demerjian method and skeletal maturation was evaluated by cervical vertebral method as presented by Bacetti. The BMI was determined for each patient. T-test was applied to compare the mean difference between chronologic and dental age among the study groups. A regression model was used to assess the relationship between BMI percentile, skeletal maturation, and dental development. 18.9% of subjects were overweight and obese. The mean differences between dental age and chronologic age were 0.73±1.3 for underweight and normal weight children and 1.8±1.08 for overweight and obese children. These results highlighted the correlation between accelerated dental maturity and increasing BMI percentile (p= 0.002). A new formula was introduced for this relationship. There was not any significant relationship between BMI percentile and skeletal maturation. Children who were overweight or obese had accelerated dental development whereas they did not have accelerated skeletal maturation significantly after being adjusted for age and gender.

Visual memories for perceived length are well preserved in older adults.

PubMed

Norman, J Farley; Holmin, Jessica S; Bartholomew, Ashley N

2011-09-15

Three experiments compared younger (mean age was 23.7years) and older (mean age was 72.1years) observers' ability to visually discriminate line length using both explicit and implicit standard stimuli. In Experiment 1, the method of constant stimuli (with an explicit standard) was used to determine difference thresholds, whereas the method of single stimuli (where the knowledge of the standard length was only implicit and learned from previous test stimuli) was used in Experiments 2 and 3. The study evaluated whether increases in age affect older observers' ability to learn, retain, and utilize effective implicit visual standards. Overall, the observers' length difference thresholds were 5.85% of the standard when the method of constant stimuli was used and improved to 4.39% of the standard for the method of single stimuli (a decrease of 25%). Both age groups performed similarly in all conditions. The results demonstrate that older observers retain the ability to create, remember, and utilize effective implicit standards from a series of visual stimuli. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dating archeological ceramics from the Valley of Vitor, Arequipa by the TL method

NASA Astrophysics Data System (ADS)

Cano, N. F.; Arizaca, E. C.; Yauri, J. M.; Arenas, J. S. A.; Watanabe, S.

The age of some ancient pottery from the Valley of Vitor in the region of Arequipa, Peru, is determined by the thermoluminescence (TL) method. For dating, a 325 °C TL peak was used and irradiation with γ-dose from 5 to 50 Gy was carried out for the additive method, and from 0.4 to 5 Gy for the regeneration method. For these dose values, the TL intensity is observed to grow linearly, obtaining an accumulated dose of 1.62±0.09 Gy and 1.36±0.03 Gy for the additive and regeneration methods, respectively. The age (A) of the sample was calculated by the two methods, being A=867±195 years after Christ (AC) for the additive method and A=1050±157 years AC for the regeneration method. Both results are within 800-1200 years AC, which is the period of the Wari culture.

Towards a method for determining age ranges from faces of juveniles on photographs.

PubMed

Cummaudo, M; Guerzoni, M; Gibelli, D; Cigada, A; Obertovà, Z; Ratnayake, M; Poppa, P; Gabriel, P; Ritz-Timme, S; Cattaneo, C

2014-06-01

The steady increase in the distribution of juvenile pornographic material in recent years strongly required valid methods for estimating the age of the victims. At the present in fact forensic experts still commonly use the assessment of sexual characteristics by Tanner staging, although they have proven to be too subjective and deceiving for age estimation. The objective of this study, inspired by a previous EU project involving Italy, Germany and Lithuania, is to verify the applicability of certain anthropometric indices of faces in order to determine age and to create a database of facial measurements on a population of children in order to improve face ageing techniques. In this study, 1924 standardized facial images in frontal view and 1921 in lateral view of individuals from 7 age groups (3-5 years, 6-8 years, 9-11 years, 12-14 years, 15-17 years, 18-20 years, 21-24 years) underwent metric analysis. Individuals were all of Caucasoid ancestry and Italian nationality. Eighteen anthropometric indices in the frontal view and five in the lateral view were then calculated from the obtained measurements. Indices showing a correlation with age were ch-ch/ex-ex, ch-ch/pu-pu, en-en/ch-ch and se-sto/ex-ex in the frontal view, se-prn/se-sn, se-prn/se-sto and se-sn/se-sto in the lateral view. All the indices increased with age except for en-en/ch-ch, without relevant differences between males and females. These results provide an interesting starting point not only for placing a photographed face in an age range but also for refining the techniques of face ageing and personal identification. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Intercultural communication in assessing dietary habits: Liberia as an example.

PubMed

Jarosz, L A

1990-08-01

Nutritionists in both clinical and field settings often work with populations whose cultures and languages differ from their own. Therefore, intercultural communication skills are often needed. This article presents a method used to collect dietary data for 125 children under 26 months old living in Liberia. The method was designed to reduce intercultural communication errors during collection of dietary data by avoiding terms directly related to the English language words "food" or "to eat," and by replacing such terms with words or phrases with a more general meaning, for example, "thing" for food or "had" for eat. By using this method the following results were obtained: mean age for introducing non-breast-milk foods to infants, 1.9 months (no. = 113, standard deviation [SD] = 2.1 months); mean age for introducing milk-based foods, 1.5 months (no. = 74, SD = 1.6 months); and mean age for introducing non-milk foods, 2.9 months (no. = 110, SD = 2.5 months). These ages are 2 to 4 months earlier than those determined in two previous studies conducted in Liberia. The difference is probably attributable to incongruity between the interviewer's and interviewee's definitions of words. The resultant impact on feeding recommendations because of differences in data and, therefore, in conclusions, demonstrates that accuracy of dietary data at the individual level may be critical for epidemiological studies. The method of using more general terms and avoiding restricting terms such as "food" and "eat" may help nutritionists improve the accuracy and completeness of dietary data during intercultural interviews. Additional research in wording dietary recall questions will help determine whether this method is generally applicable.

Are the determinants of vertebral endplate changes and severe disc degeneration in the lumbar spine the same? A magnetic resonance imaging study in middle-aged male workers

PubMed Central

Kuisma, Mari; Karppinen, Jaro; Haapea, Marianne; Niinimäki, Jaakko; Ojala, Risto; Heliövaara, Markku; Korpelainen, Raija; Kaikkonen, Kaisu; Taimela, Simo; Natri, Antero; Tervonen, Osmo

2008-01-01

Background Modic changes are bone marrow lesions visible in magnetic resonance imaging (MRI), and they are assumed to be associated with symptomatic intervertebral disc disease, especially changes located at L5-S1. Only limited information exists about the determinants of Modic changes. The objective of this study was to evaluate the determinants of vertebral endplate (Modic) changes, and whether they are similar for Modic changes and severe disc degeneration focusing on L5-S1 level. Methods 228 middle-aged male workers (159 train engineers and 69 sedentary factory workers) from northern Finland underwent sagittal T1- and T2-weighted MRI. Modic changes and disc degeneration were analyzed from the scans. The participants responded to a questionnaire including items of occupational history and lifestyle factors. Logistic regression analysis was used to evaluate the associations between selected determinants (age, lifetime exercise, weight-related factors, fat percentage, smoking, alcohol use, lifetime whole-body vibration) and Modic type I and II changes, and severe disc degeneration (= grade V on Pfirrmann's classification). Results The prevalences of the Modic changes and severe disc degeneration were similar in the occupational groups. Age was significantly associated with all degenerative changes. In the age-adjusted analyses, only weight-related determinants (BMI, waist circumference) were associated with type II changes. Exposure to whole-body vibration, besides age, was the only significant determinant for severe disc degeneration. In the multivariate model, BMI was associated with type II changes at L5-S1 (OR 2.75 per one SD = 3 unit increment in BMI), and vibration exposure with severe disc degeneration at L5-S1 (OR 1.08 per one SD = 11-year increment in vibration exposure). Conclusion Besides age, weight-related factors seem important in the pathogenesis of Modic changes, whereas whole-body vibration was the only significant determinant of severe disc degeneration. PMID:18416819

TRAINING METHODS FOR OLDER WORKERS. EMPLOYMENT OF OLDER WORKERS, 2.

ERIC Educational Resources Information Center

BELBIN, R.M.

A SURVEY WAS PRESENTED OF SCIENTIFIC KNOWLEDGE ON AGE CHANGES IN HUMAN CAPACITIES, ESPECIALLY IN LEARNING ABILITY AND ADAPTABILITY, AND DESCRIBED VARIOUS METHODS USED TO TRAIN WORKERS OVER 40. THE ROLE OF MEMORY, MOTIVATION, RIGIDITY, AND INTELLIGENCE IN DETERMINING THE LEARNING EFFICIENCY OF MATURE ADULTS WAS ASSESSED, ALSO DIFFICULTIES CAUSED BY…

Application of Network Planning to Teaching Wind-Surfing

ERIC Educational Resources Information Center

Zybko, Przemyslaw; Jaczynowski, Lech

2008-01-01

Study aim: To determine the effects of network planning on teaching untrained subjects windsurfing. Material and methods: Untrained physical education students (n = 390), aged 19-23 years, took part in the study while staying on a summer camp. They were randomly assigned into two groups: experimental (n = 216) and control (n = 174). Two methods of…

Precise and accurate in situ Pb-Pb dating of apatite, monazite, and sphene by laser ablation multiple-collector ICP-MS

NASA Astrophysics Data System (ADS)

Willigers, B. J. A.; Baker, J. A.; Krogstad, E. J.; Peate, D. W.

2002-03-01

To evaluate in situ Pb dating by laser ablation multiple-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), we analysed apatite, sphene, and monazite from Paleoproterozoic metamorphic rocks from West Greenland. Pb isotope ratios were also determined in the National Institute of Standards and Technology (NIST) 610 glass standard and were corrected for mass fractionation by reference to the measured thallium isotope ratio. The NIST 610 glass was used to monitor Pb isotope mass fractionation in the low Tl/Pb accessory minerals. Replicate analyses of the glass (1 to 2 min) yielded ratios with an external reproducibility comparable to conventional analyses of standard reference material 981 by thermal ionisation mass spectrometry (TIMS). Mineral grains were generally analysed with a 100-μm laser beam, although some monazite crystals were analysed at smaller spot sizes (10 and 25 μm). The common Pb isotope ratios required for age calculations were either measured on coexisting plagioclase by LA-MC-ICP-MS or could be ignored, as individual crystals exhibit sufficient Pb isotopic heterogeneity to perform isochron calculations on replicate analyses of single crystals. Mean mineral ages with the 204Pb ion beam measured in the multiplier were as follows: apatite, 1715 ± 23 m.y.; sphene, 1789 ± 11 m.y.; and monazite, 1783 to 1888 m.y., with relative uncertainties on individual monazite ages of <0.2% but highly reproducible age determinations on single monazite crystals (≪1%). Isochron ages calculated from several mineral analyses without assumption of common Pb also yield precise age determinations. Apatite and monazite Pb ages determined by in situ Pb isotope analysis are identical to those determined by conventional TIMS analysis of bulk mineral separates, and the analytical uncertainties of these short laser analyses with no prior mechanical or chemical separation are comparable to those obtained by TIMS. Detailed examination of the sphene in situ age data does, however, show a small discrepancy between the LA-MC-ICP-MS and TIMS ages (˜1% younger). High-resolution mass scans of the sphene during ablation clearly showed several small and as yet unidentified isobaric interferences that overlap with the 207Pb peak at the resolution conditions for measurement of isotope ratios. These might account for the age discrepancy between the LA-MC-ICP-MS and TIMS sphene ages. LA-MC-ICP-MS is a rapid, accurate, and precise method for in situ determination of Pb isotope ratios that can be used for geochronological studies in a manner similar to an ion microprobe, albeit currently at a somewhat degraded spatial resolution. Further modifications to the LA-MC-ICP-MS system, such as improved sensitivity, ion transmission, and LA methodology, may lead to this type of instrument becoming the method of choice for many types of in situ Pb isotope dating.

Postmortem aging and freezing and thawing storage enhance ability of early deboned chicken pectoralis major muscle to hold added salt water.

PubMed

Zhuang, H; Savage, E M

2012-05-01

The effects of postdeboning aging and frozen storage on water-holding capacity (WHC) of chicken breast pectoralis major muscle were investigated. Broiler breast muscle was removed from carcasses either early postmortem (2 h) or later postmortem (24 h). Treatments included: no postdeboning aging; 1-d postdeboning aging at 2°C, 7-d postdeboning aging (2-h deboned meat only), and 6-d storage at -20°C plus 1-d thawing at 2°C (freezing and thawing treatment, 2-h deboned meat only). The WHC was determined by cooking loss, drip loss, a filter paper press method (results were presented as expressible fluid), and a salt-induced swelling and centrifugation method (results were presented as percentage of salt-induced water gain). There were no differences for WHC estimated by cooking loss and expressible fluid between the treatments. Only the freezing and thawing treatment resulted in a significant increase in drip loss. The average percentage of salt-induced water gains by the 24-h deboned samples, postdeboning aged 2 h samples, and frozen 2 h sample, which did not differ from each other, were significantly higher than that by the 2-h deboned sample. These results indicate that regardless of method (carcass aging vs. postdeboning aging) and time (aging for 1 d vs. for 7 d), postmortem aging more than 1 d does not affect WHC of the early deboned samples measured by dripping, cooking, and pressing. However, postmortem carcass aging, postdeboning aging, and freezing and thawing storage can significantly enhance the ability of chicken breast meat to hold added salt water or WHC measured by the salt-induced swelling and centrifuge method.

A simple-rapid method to separate uranium, thorium, and protactinium for U-series age-dating of materials

PubMed Central

Knight, Andrew W.; Eitrheim, Eric S.; Nelson, Andrew W.; Nelson, Steven; Schultz, Michael K.

2017-01-01

Uranium-series dating techniques require the isolation of radionuclides in high yields and in fractions free of impurities. Within this context, we describe a novel-rapid method for the separation and purification of U, Th, and Pa. The method takes advantage of differences in the chemistry of U, Th, and Pa, utilizing a commercially-available extraction chromatographic resin (TEVA) and standard reagents. The elution behavior of U, Th, and Pa were optimized using liquid scintillation counting techniques and fractional purity was evaluated by alpha-spectrometry. The overall method was further assessed by isotope dilution alpha-spectrometry for the preliminary age determination of an ancient carbonate sample obtained from the Lake Bonneville site in western Utah (United States). Preliminary evaluations of the method produced elemental purity of greater than 99.99% and radiochemical recoveries exceeding 90% for U and Th and 85% for Pa. Excellent purity and yields (76% for U, 96% for Th and 55% for Pa) were also obtained for the analysis of the carbonate samples and the preliminary Pa and Th ages of about 39,000 years before present are consistent with 14C-derived age of the material. PMID:24681438

Evaluating paper degradation progress. Cross-linking between chromatographic, spectroscopic and chemical results

NASA Astrophysics Data System (ADS)

Łojewski, Tomasz; Zięba, Katarzyna; Knapik, Arkadiusz; Bagniuk, Jacek; Lubańska, Anna; Łojewska, Joanna

2010-09-01

The study presents an overview of the chromatographic (SEC), spectroscopic (FTIR, UV/VIS), viscometric (DP) and chemical methods (titration, pH) used for the evaluation of the degradation progress of various kinds of paper under various conditions. The methods were chosen to follow different routes of paper degradation. Model paper samples represented boundary paper types from pure cellulose cotton paper, through softwood to low quality acidic, sized groundwood paper The accelerated ageing conditions were adjusted to achieve maximum effect (climatic chamber RH 59%, 90oC) and also to mimic the environment inside books (closed vials). The results were settled on the literature data on the degradation mechanisms and compared in terms of the paper types and ageing conditions. The estimators of coupled de-polymerisation and oxidation have been proposed based on the correlation between SEC, UV/VIS and titrative coppper number determination. The overall oxidation index derived from FTIR results was shown to correlate with the summary -CHO and -COOH concentration determined by titrative methods.

Asteroseismic modelling of solar-type stars: internal systematics from input physics and surface correction methods

NASA Astrophysics Data System (ADS)

Nsamba, B.; Campante, T. L.; Monteiro, M. J. P. F. G.; Cunha, M. S.; Rendle, B. M.; Reese, D. R.; Verma, K.

2018-07-01

Asteroseismic forward modelling techniques are being used to determine fundamental properties (e.g. mass, radius, and age) of solar-type stars. The need to take into account all possible sources of error is of paramount importance towards a robust determination of stellar properties. We present a study of 34 solar-type stars for which high signal-to-noise asteroseismic data are available from multiyear Kepler photometry. We explore the internal systematics on the stellar properties, that is associated with the uncertainty in the input physics used to construct the stellar models. In particular, we explore the systematics arising from (i) the inclusion of the diffusion of helium and heavy elements; (ii) the uncertainty in solar metallicity mixture; and (iii) different surface correction methods used in optimization/fitting procedures. The systematics arising from comparing results of models with and without diffusion are found to be 0.5 per cent, 0.8 per cent, 2.1 per cent, and 16 per cent in mean density, radius, mass, and age, respectively. The internal systematics in age are significantly larger than the statistical uncertainties. We find the internal systematics resulting from the uncertainty in solar metallicity mixture to be 0.7 per cent in mean density, 0.5 per cent in radius, 1.4 per cent in mass, and 6.7 per cent in age. The surface correction method by Sonoi et al. and Ball & Gizon's two-term correction produce the lowest internal systematics among the different correction methods, namely, ˜1 per cent, ˜1 per cent, ˜2 per cent, and ˜8 per cent in mean density, radius, mass, and age, respectively. Stellar masses obtained using the surface correction methods by Kjeldsen et al. and Ball & Gizon's one-term correction are systematically higher than those obtained using frequency ratios.

Film Reviews

ERIC Educational Resources Information Center

Ladd, George T.

1974-01-01

Briefly describes films about the following topics: water cycles, the energy crisis, the eruption of Mt. Aetna, the hot springs of Yellowstone National Park, and methods of using pine cones to determine the ages of ancient civilizations. (MLH)

Dental cementum in age estimation: a polarized light and stereomicroscopic study.

PubMed

Kasetty, Sowmya; Rammanohar, M; Raju Ragavendra, T

2010-05-01

Dental hard tissues are good candidates for age estimation as they are less destructive and procedures to determine age can be easily performed. Although cementum annulations and cementum thickness are important parameters in this regard, they are seldom used. This study was undertaken to review the methods, difficulties in execution of techniques, and accuracy of cementum thickness and annulations in estimating the age. Unstained and stained ground sections of tooth were used to measure cemental thickness and count cemental annulations based on which age was estimated and was compared with known age. Although there was positive relation between cemental thickness and annulations with age, only in 1-1.5% of cases, age could be predicted with accuracy.

Effect of sample inhomogeneity in KAr dating

USGS Publications Warehouse

Engels, J.C.; Ingamells, C.O.

1970-01-01

Error in K-Ar ages is often due more to deficiencies in the splitting process, whereby portions of the sample are taken for potassium and for argon determination, than to imprecision in the analytical methods. The effect of the grain size of a sample and of the composition of a contaminating mineral can be evaluated, and this provides a useful guide in attempts to minimize error. Rocks and minerals should be prepared for age determination with the effects of contaminants and grain size in mind. The magnitude of such effects can be much larger than intuitive estimates might indicate. ?? 1970.

Evaluation of neutron sources for ISAGE-in-situ-NAA for a future lunar mission.

PubMed

Li, X; Breitkreutz, H; Burfeindt, J; Bernhardt, H-G; Trieloff, M; Hopp, J; Jessberger, E K; Schwarz, W H; Hofmann, P; Hiesinger, H

2011-11-01

For a future Moon landing, a concept for an in-situ NAA involving age determination using the (40)Ar-(39)Ar method is developed. A neutron source (252)Cf is chosen for sample irradiation on the Moon. A special sample-in-source irradiation geometry is designed to provide a homogeneous distribution of neutron flux at the irradiation position. Using reflector, the neutron flux is likely to increase by almost 200%. Sample age of 1Ga could be determined. Elemental analysis using INAA is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Particle size analysis of lamb meat: Effect of homogenization speed, comparison with myofibrillar fragmentation index and its relationship with shear force.

PubMed

Karumendu, L U; Ven, R van de; Kerr, M J; Lanza, M; Hopkins, D L

2009-08-01

The impact of homogenization speed on Particle Size (PS) results was examined using samples from the M.longissimus thoracis et lumborum (LL) of 40 lambs. One gram duplicate samples from meat aged for 1 and 5days were homogenized at five different speeds; 11,000, 13,000, 16,000, 19,000 and 22,000rpm. In addition to this LL samples from 30 different lamb carcases also aged for 1 and 5days were used to study the comparison between PS and myofibrillar fragmentation index (MFI) values. In this case, 1g duplicate samples (n=30) were homogenized at 16,000rpm and the other half (0.5g samples) at 11,000rpm (n=30). The homogenates were then subjected to respective combinations of treatments which included either PS analysis or the determination of MFI, both with or without three cycles of centrifugation. All 140 samples of LL included 65g blocks for subsequent shear force (SF) testing. Homogenization at 16,000rpm provided the greatest ability to detect ageing differences for particle size between samples aged for 1 and 5days. Particle size at the 25% quantile provided the best result for detecting differences due to ageing. It was observed that as ageing increased the mean PS decreased and was significantly (P<0.001) less for 5days aged samples compared to 1day aged samples, while MFI values significantly increased (P<0.001) as ageing period increased. When comparing the PS and MFI methods it became apparent that, as opposed to the MFI method, there was a greater coefficient of variation for the PS method which warranted a quality assurance system. Given this requirement and examination of the mean, standard deviation and the 25% quantile for PS data it was concluded that three cycles of centrifugation were not necessary and this also applied to the MFI method. There were significant correlations (P<0.001) within the same lamb loin sample aged for a given period between mean MFI and mean PS (-0.53), mean MFI and mean SF (-0.38) and mean PS and mean SF (0.23). It was concluded that PS analysis offers significant potential for streamlining determination of myofibrillar degradation when samples are measured after homogenization at 16,000rpm with no centrifugation.

Recommendations for the treatment of aging in standard technical specifications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orton, R.D.; Allen, R.P.

1995-09-01

As part of the US Nuclear Regulatory Commission`s Nuclear Plant Aging Research Program, Pacific Northwest Laboratory (PNL) evaluated the standard technical specifications for nuclear power plants to determine whether the current surveillance requirements (SRs) were effective in detecting age-related degradation. Nuclear Plant Aging Research findings for selected systems and components were reviewed to identify the stressors and operative aging mechanisms and to evaluate the methods available to detect, differentiate, and trend the resulting aging degradation. Current surveillance and testing requirements for these systems and components were reviewed for their effectiveness in detecting degraded conditions and for potential contributions to prematuremore » degradation. When the current surveillance and testing requirements appeared ineffective in detecting aging degradation or potentially could contribute to premature degradation, a possible deficiency in the SRs was identified that could result in undetected degradation. Based on this evaluation, PNL developed recommendations for inspection, surveillance, trending, and condition monitoring methods to be incorporated in the SRs to better detect age- related degradation of these selected systems and components.« less

Determinants of modern family planning use among women of reproductive age in the Nkwanta district of Ghana: a case–control study

PubMed Central

2014-01-01

Background Average contraceptive prevalence rate in the Nkwanta district of Ghana was estimated to be 6.2% relative to the national average at the time, of 19%. While several efforts had been made to improve family planning in the country, the district still had very low use of modern family planning methods. This study sought to determine the factors that influenced modern family planning use in general and specifically, the factors that determined the consistently low use of modern family planning methods in the district. Methods A case–control study was conducted in the Nkwanta district of Ghana to determine socio-economic, socio-cultural and service delivery factors influencing family planning usage. One hundred and thirty cases and 260 controls made up of women aged 15–49 years were interviewed using structured questionnaires. A logistic regression was fitted. Results Awareness and knowledge of modern family planning methods were high among cases and controls (over 90%). Lack of formal education among women, socio-cultural beliefs and spousal communication were found to influence modern family planning use. Furthermore, favourable opening hours of the facilities and distance to health facilities influenced the use of modern contraceptives. Conclusion While modern family planning seemed to be common knowledge among these women, actual use of such contraceptives was limited. There is need to improve use of modern family planning methods in the district. In addition to providing health facilities and consolidating close-to-client service initiatives in the district, policies directed towards improving modern family planning method use need to consider the influence of formal education. Promoting basic education, especially among females, will be a crucial step as the district is faced with high levels of school dropout and illiteracy rates. PMID:25117887

The rate of preterm birth in the United States is affected by the method of gestational age assignment.

PubMed

Duryea, Elaine L; McIntire, Donald D; Leveno, Kenneth J

2015-08-01

The objective of the study was to examine the rate of preterm birth in the United States using 2 different methods of gestational age assignment and determine which method more closely correlates with the known morbidities associated with preterm birth. Using National Center for Health Statistics data from 2012 United States birth certificates, we computed the rate of preterm birth defined as a birth at 36 or fewer completed weeks with gestational age assigned using the obstetric estimate as specified in the revised birth certificate. This rate was then compared with the rate when gestational age is calculated using the last menstrual period alone. The rates of neonatal morbidities associated with preterm birth were examined for each method of assigning gestational age. The rate of preterm birth was 9.7% when the obstetric estimate is used to calculate gestational age, which is significantly different from the rate of 11.5% when gestational age is calculated using the last menstrual period alone. In addition, the neonates identified as preterm by obstetric estimate were more likely to qualify as low birthweight (54% vs 42%; P < .001) and suffer morbidities such as need for assisted ventilation and surfactant use than those identified with the last menstrual period alone. That is to say obstetric estimate is more sensitive and specific for preterm birth by all available markers of prematurity. The preterm birth rate is 9.7% vs 11.5% and more closely correlates with adverse neonatal outcomes associated with preterm birth when gestational age is assigned using the obstetric estimate. This method of gestational age assignment is currently used by most industrialized nations and should be considered for future reporting of US outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.

Distribution of Salivary Testosterone in Men and Women in a British General Population-Based Sample: The Third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)

PubMed Central

Clifton, Soazig; Tanton, Clare; Macdowall, Wendy; Copas, Andrew J.; Lee, David; Field, Nigel; Mitchell, Kirstin R.; Sonnenberg, Pam; Bancroft, John; Mercer, Cath H.; Johnson, Anne M.; Wellings, Kaye; Wu, Frederick C. W.

2017-01-01

Introduction: Measurement of salivary testosterone (Sal-T) to assess androgen status offers important potential advantages in epidemiological research. The utility of the method depends on the interpretation of the results against robustly determined population distributions, which are currently lacking. Aim: To determine age-specific Sal-T population distributions for men and women. Methods: Morning saliva samples were obtained from participants in the third National Survey of Sexual Attitudes and Lifestyles, a probability sample survey of the British general population. Sal-T was measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Linear and quantile regression analyses were used to determine the age-specific 2.5th and 97.5th percentiles for the general population (1675 men and 2453 women) and the population with health exclusions (1145 men and 1276 women). Results: In the general population, the mean Sal-T level in men decreased from 322.6 pmol/L at 18 years of age to 153.9 pmol/L at 69 years of age. In women, the decrease in the geometric mean Sal-T level was from 39.8 pmol/L at 18 years of age to 19.5 pmol/L at 74 years of age. The annual decrease varied with age, with an average of 1.0% to 1.4% in men and 1.3% to 1.5% in women. For women, the 2.5th percentile fell below the detection limit (<6.5 pmol/L) from age 52 years onward. The mean Sal-T level was approximately 6 times greater in men than in women, and this remained constant over the age range. The Sal-T level was lowest for men and highest for women in the summer. The results were similar for the general population with exclusions. Conclusions: To our knowledge, this is the first study to describe the sex- and age-specific distributions for Sal-T in a large representative population using a specific and sensitive LC-MS/MS technique. The present data can inform future population research by facilitating the interpretation of Sal-T results as a marker of androgen status. PMID:29264442

Factors Contributing to Regular Smoking in Adolescents in Turkey

ERIC Educational Resources Information Center

Can, Gamze; Topbas, Murat; Oztuna, Funda; Ozgun, Sukru; Can, Emine; Yavuzyilmaz, Asuman

2009-01-01

Purpose: The objectives of this study were to determine the levels of lifetime cigarette use, daily use, and current use among young people (aged 15-19 years) and to examine the risk factors contributing to regular smoking. Methods: The number of students was determined proportionately to the numbers of students in all the high schools in the…

Animal Cruelty by Children Exposed to Domestic Violence

ERIC Educational Resources Information Center

Currie, Cheryl L.

2006-01-01

Objective: The first objective of this study was to determine if children exposed to domestic violence were significantly more likely to be cruel to animals than children not exposed to violence. The second was to determine if there were significant age and gender differences between children who were and were not cruel to animals. Method: A…

Parents' Role in Early Adolescent Self-Injury: An Application of Self-Determination Theory

ERIC Educational Resources Information Center

Emery, A. Ann; Heath, Nancy L.; Rogers, Maria

2017-01-01

Objective: We applied self-determination theory to examine a model whereby perceived parental autonomy support directly and indirectly affects nonsuicidal self-injury (NSSI) through difficulties in emotion regulation. Method: 639 participants (53% female) with a mean age of 13.38 years (SD 0.51) completed the How I Deal with Stress Questionnaire…

A methodology to measure cervical vertebral bone maturation in a sample from low-income children.

PubMed

Aguiar, Luciana Barreto Vieira; Caldas, Maria de Paula; Haiter Neto, Francisco; Ambrosano, Glaucia Maria Bovi

2013-01-01

This study evaluated the applicability of the regression method for determining vertebral age developed by Caldas et al. (2007) by testing this method in children from low-income families of the rural zone. The sample comprised cephalometric and hand-wrist radiographs of 76 boys and 64 girls aged 7.0 to 14.9 years living in a medium-sized city in the desert region of the northeastern region of Brazil, with an HDI of 0.678. C3 and C4 vertebrae were traced and measured on cephalometric radiographs to estimate the bone age. The average age, average hand-wrist age and average error estimated for girls and boys were, respectively, 10.62 and 10.44 years, 11.28 and 10.57 years, and 1.42 and 1.18 years. Based on these results, the formula proposed by Caldas et al. (2007) was not applicable to the studied population, and new multiple regression models were developed to obtain the children's vertebral bone age accurately.

Lumbar spinal mobility changes among adults with advancing age

PubMed Central

Saidu, Ismaila Adamu; Maduagwu, Stanley Monday; Abbas, Abdullahi Digil; Adetunji, Omotayo O.; Jajere, Abdurahman Mohammed

2011-01-01

Background: Limitations in spinal mobility can interfere with the attainment of important functional skills and activities of daily living and restrictions in spinal mobility are usually the earliest and reliable indicator of diseases. Objective: The aim of this study was to determine the differences of lumbar spinal mobility among healthy adults with advancing age. Materials and Methods: The modified Schober's method was used to measure anterior flexion. The guideline of the American Academy of Orthopaedic Surgeons was adapted to measure lateral flexion and extension. Results: The results of this study indicate that spinal mobility decreases with advancing age. The most significant (P < 0.05) differences occurred between the two youngest and the two oldest age categories. Conclusion: Using these data, we developed normative values of spinal mobility for each sex and age group. This study helps the clinicians to understand and correlate the restrictions of lumbar spinal mobility due to age and differentiate the limitations due to disease. PMID:22408334

[Size of testes and epididymes in boys up to 17 years of life assessed by ultrasound method and method of external linear measurements].

PubMed

Osemlak, Paweł

2011-01-01

1. Determination of the size of testes and epididymes on the right and left side, in healthy boys in various age groups with use of non-invasive ultrasound examination method and the method of external linear measurements. 2. Determination of age, when intensive growth of testicular and epididymal size starts. 3. Determination whether there are statistically significant differences between the size of the right and the left testis, as well as between the right and left epididymis. 4. Evaluation of the ultrasound method and method of external linear measurements in their use for scientific investigations. 309 boys, aged from 1 day to 17 years of life, treated in the Clinical Department of Paediatric Surgery and Traumatology of the Medical University in Lublin from 2009 to 2010 due to diseases needed to be treated surgically, but not the scrotum, were examined in this study. No pathologies influencing the development of genital organs were found in these boys. Dimension of the testes was studied with ultrasound method and with method of external linear measurements. Dimension of epididymes was only examined with ultrasound method. In every age group the author calculated mean arithmetical values for: testiscular length, thickness, width and volume, as well as epididymal depth and basis. With consideration of standard deviation (X+/-1 SD) it was possible to define the range of dimension of healthy testes and epididymes and their change with age. Final dimensions of the right and left testis as well as of the right and left epididymis were compared. Dimensions of the testis on the same side of body acquired with the ultrasound method and acquired with the method of external linear measurements were compared. Statistical work-up with Wilcoxon test for two dependent groups was implemented. Ultrasound evaluation pointed to intensive 2.5-times increase in testicular length and width, and 2-times increase in testicular thickness in boys aged 10 to 17 years. Mean volume of neonatal testis is 0.35 ml. From 10th year of life, the testicular volume increases 10-times from 1.36 ml to 12.83 ml in 17th year of life. Depth of epididymis measured with ultrasound method is always greater than its basis. Both these dimensions increase quickly from the 10th year of life. Measurements done with the caliper on the average overestimate testicular length by 5.7 mm, its thickness by 2.9 mm and its width by 1.4 mm, comparing with ultrasound method. There were no statistically important differences between dimension of the right and left testis. Differences between dimension of the right and left epididymis are statistically significant. 1. Age is the main factor influencing testicular size in boys. 2. Intensive growth of testes starts in the 10th year of life, of epididymes in 12th year of life. 3. Testicular volume is the most precise description of its size. There are no statisticallysignificant differences between volume of the right and left testis. Differences between dimension, described by the depth and basis of the right and left epididymis are statistically significant. 4. Ultrasound method and method of external linear measurements with the caliper have similar diagnostic value in comparing the size of both testes. 5. Measurements of testicular size with ultrasound method have much greater value for detail evaluation than the method of external linear measurements with the caliper, which does not regard thickness of the skin and testicular coats, as well as the epididymal head which is often situated on the upper end of the testis.

Validity and reliability of dental age estimation of teeth root translucency based on digital luminance determination.

PubMed

Ramsthaler, Frank; Kettner, Mattias; Verhoff, Marcel A

2014-01-01

In forensic anthropological casework, estimating age-at-death is key to profiling unknown skeletal remains. The aim of this study was to examine the reliability of a new, simple, fast, and inexpensive digital odontological method for age-at-death estimation. The method is based on the original Lamendin method, which is a widely used technique in the repertoire of odontological aging methods in forensic anthropology. We examined 129 single root teeth employing a digital camera and imaging software for the measurement of the luminance of the teeth's translucent root zone. Variability in luminance detection was evaluated using statistical technical error of measurement analysis. The method revealed stable values largely unrelated to observer experience, whereas requisite formulas proved to be camera-specific and should therefore be generated for an individual recording setting based on samples of known chronological age. Multiple regression analysis showed a highly significant influence of the coefficients of the variables "arithmetic mean" and "standard deviation" of luminance for the regression formula. For the use of this primer multivariate equation for age-at-death estimation in casework, a standard error of the estimate of 6.51 years was calculated. Step-by-step reduction of the number of embedded variables to linear regression analysis employing the best contributor "arithmetic mean" of luminance yielded a regression equation with a standard error of 6.72 years (p < 0.001). The results of this study not only support the premise of root translucency as an age-related phenomenon, but also demonstrate that translucency reflects a number of other influencing factors in addition to age. This new digital measuring technique of the zone of dental root luminance can broaden the array of methods available for estimating chronological age, and furthermore facilitate measurement and age classification due to its low dependence on observer experience.

Qualitative Investigation of the Decomposition of Organic Solvent Based Lithium Ion Battery Electrolytes with LC-IT-TOF-MS.

PubMed

Schultz, Carola; Vedder, Sven; Winter, Martin; Nowak, Sascha

2016-11-15

The development of a novel high performance liquid chromatography (HPLC) method hyphenated to an ion-trap time-of-flight mass spectrometer (IT-TOF-MS) for the separation and identification of constituents from common organic carbonate solvent-based electrolyte systems in lithium ion batteries (LIBs) is presented in this work. The method development was conducted for the qualitative structural elucidation of electrolyte main constituents with a special focus on the aging products of these components. The determination of their limits of detection was performed as well. Four different LiPF 6 -based LIB electrolytes were investigated in this study. The selected aging procedures for the electrolytes were thermal aging (storage at 60 °C for 2 weeks, storage at 60 °C in the presence of 2 vol % water contamination for 2 weeks) and electrochemical aging for 100 cycles at 2C. After thermal aging, several aging products were identified. The formation of organic phosphate aging products and several organofluorophosphates aging products was observed after thermal aging with water. Additionally, the content of carbonate aging products increased. After electrochemical aging, several carbonate aging products were detected. Electrochemical aging at 60 °C leads to the additional generation of organofluorophosphate aging products.

Chronic Conditions and Mortality Among the Oldest Old

PubMed Central

Lee, Sei J.; Go, Alan S.; Lindquist, Karla; Bertenthal, Daniel; Covinsky, Kenneth E.

2008-01-01

Objectives. We sought to determine whether chronic conditions and functional limitations are equally predictive of mortality among older adults. Methods. Participants in the 1998 wave of the Health and Retirement Study (N=19430) were divided into groups by decades of age, and their vital status in 2004 was determined. We used multivariate Cox regression to determine the ability of chronic conditions and functional limitations to predict mortality. Results. As age increased, the ability of chronic conditions to predict mortality declined rapidly, whereas the ability of functional limitations to predict mortality declined more slowly. In younger participants (aged 50–59 years), chronic conditions were stronger predictors of death than were functional limitations (Harrell C statistic 0.78 vs. 0.73; P=.001). In older participants (aged 90–99 years), functional limitations were stronger predictors of death than were chronic conditions (Harrell C statistic 0.67 vs. 0.61; P=.004). Conclusions. The importance of chronic conditions as a predictor of death declined rapidly with increasing age. Therefore, risk-adjustment models that only consider comorbidities when comparing mortality rates across providers may be inadequate for adults older than 80 years. PMID:18511714

Risk factors, prevalence trend, and clustering of hypospadias cases in Puerto Rico.

PubMed

Avilés, Luis A; Alvelo-Maldonado, Laureane; Padró-Mojica, Irmari; Seguinot, José; Jorge, Juan Carlos

2014-12-01

The aim was to determine the distribution pattern of hypospadias cases across a well-defined geographic space. The dataset for this study was produced by the Birth Defects Prevention and Surveillance System of the Department of Health of Puerto Rico (BDSS-PR), which linked the information of male newborns of the Puerto Rico Birth Cohort dataset (PRBC; n=92,285) from 2007 to 2010. A population-based case-control study was conducted to determine prevalence trend and to estimate the potential effects of maternal age, paternal age, birth-related variables, and health insurance status on hypospadias. Two types of geographic information systems (GIS) methods (Anselin Local Moran's I and Getis-Ord G) were used to determine the spatial distribution of hypospadias prevalence. Birthweight (<2500 g), age of mother (40+years), and private health insurance were associated with hypospadias as confirmed with univariate and multivariate analyses at 95% CI. A cluster of hypospadias cases was detected in the north-central region of Puerto Rico with both GIS methods (p≤0.05). The clustering of hypospadias prevalence provides an opportunity to assess the underlying causes of the condition and their relationships with geographical space. Copyright © 2014 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Ageing airplane repair assessment program for Airbus A300

NASA Technical Reports Server (NTRS)

Gaillardon, J. M.; Schmidt, HANS-J.; Brandecker, B.

1992-01-01

This paper describes the current status of the repair categorization activities and includes all details about the methodologies developed for determination of the inspection program for the skin on pressurized fuselages. For inspection threshold determination two methods are defined based on fatigue life approach, a simplified and detailed method. The detailed method considers 15 different parameters to assess the influences of material, geometry, size location, aircraft usage, and workmanship on the fatigue life of the repair and the original structure. For definition of the inspection intervals a general method is developed which applies to all concerned repairs. For this the initial flaw concept is used by considering 6 parameters and the detectable flaw sizes depending on proposed nondestructive inspection methods. An alternative method is provided for small repairs allowing visual inspection with shorter intervals.

Usefulness of telomere length in DNA from human teeth for age estimation.

PubMed

Márquez-Ruiz, Ana Belén; González-Herrera, Lucas; Valenzuela, Aurora

2018-03-01

Age estimation is widely used to identify individuals in forensic medicine. However, the accuracy of the most commonly used procedures is markedly reduced in adulthood, and these methods cannot be applied in practice when morphological information is limited. Molecular methods for age estimation have been extensively developed in the last few years. The fact that telomeres shorten at each round of cell division has led to the hypothesis that telomere length can be used as a tool to predict age. The present study thus aimed to assess the correlation between telomere length measured in dental DNA and age, and the effect of sex and tooth type on telomere length; a further aim was to propose a statistical regression model to estimate the biological age based on telomere length. DNA was extracted from 91 tooth samples belonging to 77 individuals of both sexes and 15 to 85 years old and was used to determine telomere length by quantitative real-time PCR. Our results suggested that telomere length was not affected by sex and was greater in molar teeth. We found a significant correlation between age and telomere length measured in DNA from teeth. However, the equation proposed to predict age was not accurate enough for forensic age estimation on its own. Age estimation based on telomere length in DNA from tooth samples may be useful as a complementary method which provides an approximate estimate of age, especially when human skeletal remains are the only forensic sample available.

Cameriere's third molar maturity index in assessing age of majority.

PubMed

Galić, Ivan; Lauc, Tomislav; Brkić, Hrvoje; Vodanović, Marin; Galić, Elizabeta; Biazevic, Maria Gabriela Haye; Brakus, Ivan; Badrov, Jozo; Cameriere, Roberto

2015-07-01

Estimation of chronological age of an individual is one of the main challenges in forensic science. Legally to be able to treat a person as a minor or an adult, it is necessary to determine whether their age of majority (if they are older or younger than 18, in most countries). Methods for estimating age are especially important when an individual in question lacks personal documents or other means of identification. As the dental age differs in various populations, the aim of this study was to evaluate applicability of third molar method for assessing age of majority in Croatia. Cameriere's third molar maturity index (I3M) value of 0.08, measured by the open apices of the teeth, was verified in sample of 1336 panoramic images aged between 14 and 23 years. Chronological age gradually decreased as I3M increased in both genders. Males showed statistically significant advanced maturation when I3M was between 0.0 and 0.3 value. The results indicate that the sensitivity of the test for 0.08 value was 84.3% (95%CI 80.6%, 87.5%) for females and 91.2% (95%CI 88.7%, 93.1) for males. Specificity was 95.4% (95%CI 92.5%, 97.5%) and 91.9% (95%CI 88.8%, 94.3%). The proportions of accurately classified males were 88.8% and that of females 91.5%. The estimated post-test probabilities, of individuals, in other word the probability that a Croatian individual with an I3M<0.08 is 18 years or older is 94.5% for females, and 96.5% for males. With high accuracy, the third molar maturity index should be used as a determinant of the age of majority in Croatia. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

BANYAN. IV. Fundamental parameters of low-mass star candidates in nearby young stellar kinematic groups—isochronal age determination using magnetic evolutionary models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malo, Lison; Doyon, René; Albert, Loïc

2014-09-01

Based on high-resolution optical spectra obtained with ESPaDOnS at Canada-France-Hawaii Telescope, we determine fundamental parameters (T {sub eff}, R, L {sub bol}, log g, and metallicity) for 59 candidate members of nearby young kinematic groups. The candidates were identified through the BANYAN Bayesian inference method of Malo et al., which takes into account the position, proper motion, magnitude, color, radial velocity, and parallax (when available) to establish a membership probability. The derived parameters are compared to Dartmouth magnetic evolutionary models and field stars with the goal of constraining the age of our candidates. We find that, in general, low-mass starsmore » in our sample are more luminous and have inflated radii compared to older stars, a trend expected for pre-main-sequence stars. The Dartmouth magnetic evolutionary models show a good fit to observations of field K and M stars, assuming a magnetic field strength of a few kG, as typically observed for cool stars. Using the low-mass members of the β Pictoris moving group, we have re-examined the age inconsistency problem between lithium depletion age and isochronal age (Hertzspring-Russell diagram). We find that the inclusion of the magnetic field in evolutionary models increases the isochronal age estimates for the K5V-M5V stars. Using these models and field strengths, we derive an average isochronal age between 15 and 28 Myr and we confirm a clear lithium depletion boundary from which an age of 26 ± 3 Myr is derived, consistent with previous age estimates based on this method.« less

Age estimation of archaeological remains using amino acid racemization in dental enamel: a comparison of morphological, biochemical, and known ages-at-death.

PubMed

Griffin, R C; Chamberlain, A T; Hotz, G; Penkman, K E H; Collins, M J

2009-10-01

The poor accuracy of most current methods for estimating age-at-death in adult human skeletal remains is among the key problems facing palaeodemography. In forensic science, this problem has been solved for unburnt remains by the development of a chemical method for age estimation, using amino acid racemization in collagen extracted from dentine. Previous application of racemization methods to archaeological material has proven problematic. This study presents the application to archaeological human remains of a new age estimation method utilizing amino acid racemization in a potentially closed system-the dental enamel. The amino acid composition and extent of racemization in enamel from two Medieval cemeteries (Newcastle Blackgate and Grantham, England) and from a documented age-at-death sample from a 19th century cemetery (Spitalfriedhof St Johann, Switzerland) were determined. Alterations in the amino acid composition were detected in all populations, indicating that diagenetic change had taken place. However, in the Medieval populations, these changes did not appear to have substantially affected the relationship between racemization and age-at-death, with a strong relationship being retained between aspartic acid racemization and the morphological age estimates. In contrast, there was a poor relationship between racemization and age in the post-medieval documented age-at-death population from Switzerland. This appears to be due to leaching of amino acids post-mortem, indicating that enamel is not functioning as a perfectly closed system. Isolation of amino acids from a fraction of enamel which is less susceptible to leaching may improve the success of amino acid racemization for archaeological age estimation.

Can we set a global threshold age to define mature forests?

PubMed

Martin, Philip; Jung, Martin; Brearley, Francis Q; Ribbons, Relena R; Lines, Emily R; Jacob, Aerin L

2016-01-01

Globally, mature forests appear to be increasing in biomass density (BD). There is disagreement whether these increases are the result of increases in atmospheric CO2 concentrations or a legacy effect of previous land-use. Recently, it was suggested that a threshold of 450 years should be used to define mature forests and that many forests increasing in BD may be younger than this. However, the study making these suggestions failed to account for the interactions between forest age and climate. Here we revisit the issue to identify: (1) how climate and forest age control global forest BD and (2) whether we can set a threshold age for mature forests. Using data from previously published studies we modelled the impacts of forest age and climate on BD using linear mixed effects models. We examined the potential biases in the dataset by comparing how representative it was of global mature forests in terms of its distribution, the climate space it occupied, and the ages of the forests used. BD increased with forest age, mean annual temperature and annual precipitation. Importantly, the effect of forest age increased with increasing temperature, but the effect of precipitation decreased with increasing temperatures. The dataset was biased towards northern hemisphere forests in relatively dry, cold climates. The dataset was also clearly biased towards forests <250 years of age. Our analysis suggests that there is not a single threshold age for forest maturity. Since climate interacts with forest age to determine BD, a threshold age at which they reach equilibrium can only be determined locally. We caution against using BD as the only determinant of forest maturity since this ignores forest biodiversity and tree size structure which may take longer to recover. Future research should address the utility and cost-effectiveness of different methods for determining whether forests should be classified as mature.

Dental utilization for adult Medicaid enrollees having intellectual and developmental disabilities (IDD)

PubMed Central

Chalmers, Jane M.; Kuthy, Raymond A.; Momany, Elizabeth T.; Chi, Donald L.; Bacon, Robert A.; Lindgren, Scott D.; Askelson, Natoshia M.; Damiano, Peter C.

2012-01-01

Purpose To determine dental utilization and type of dental services for Medicaid enrolled adults identified as having intellectual and developmental disabilities (IDD). Methods Using Iowa claims data, identified adults who met any of five IDD criteria for inclusion during calendar year 2005. Service utilization rates, including use of preventive dental, routine restorative, and complex restorative services, were determined. Results Approximately 60% of adults with IDD had at least one dental visit in 2005. Of adults with at least one dental visit, 83% received a preventive service, 31% a routine restorative service, and 16% a complex dental service. Those age 65 and older had fewer preventive dental services than other age groups. Conclusion In Iowa, dental utilization for adults 22-64 years of age with IDD was reasonably high (64%) in 2005, but individuals over age 65 had lower utilization (45%). PMID:21235610

A Complication in Determining the Precise Age of the Solar System

NASA Astrophysics Data System (ADS)

Brennecka, G. A.

2010-01-01

Primitive components in meteorites contain a detailed record of the conditions and processes in the solar nebula, the cloud of dust and gas surrounding the infant Sun. Determining accurately when the first materials formed requires the lead-lead (Pb-Pb) dating method, a method based on the decay of uranium (U) isotopes to Pb isotopes. The initial ratio of U-238 to U-235 is critical to determining the ages correctly, and many studies have concluded that the ratio is constant for any given age. However, my colleagues at Arizona State University, Institut fur Geowissenschaften, Goethe-Universitat (Frankfurt, Germany), and the Senckenberg Forschungsinstitut und Naturmuseum (also in Frankfurt) and I have found that some calcium-aluminum-rich inclusions (CAIs) in chondritic meteorites deviate from the conventional value for the U-238/U-235 ratio. This could lead to inaccuracies of up to 5 million years in the age of these objects, if no correction is made. Variations in the concentrations of thorium and neodymium with the U-238/U-235 ratio suggest that the ratio may have been lowered by the decay of curium-247, which decays to U-235 with a half-life of 15.6 million years. Curium-247 is created in certain types of energetic supernovae, so its presence suggests that a supernova added material to the pre-solar interstellar cloud between 110 and 140 million years before the Solar System began to form.

In vitro determination of the anti-aging potential of four southern African medicinal plants

PubMed Central

2013-01-01

Background Aging is an inevitable process for all living organisms. During this process reactive oxygen species generation is increased which leads to the activation of hyaluronidase, collagenase and elastase, which can further contribute to skin aging. Four southern African medicinal plants; Clerodendrum glabrum, Schotia brachypetala, Psychotria capensis and Peltophorum africanum, were investigated to assess their anti-aging properties. Methods Anti-elastase, anti-collagenase and anti-hyaluronidase activities of twenty-eight samples, consisting of methanol and ethyl acetate extracts of the four plants, were determined using spectrophotometric methods. Radical scavenging activity was determined by the ability of the plant extracts to scavenge the ABTS•+ radical. Results The majority of the samples in the anti-elastase assay and nine in the anti-collagenase assay showed more than 80% inhibition. The ethyl acetate extract of S. brachypetala bark and leaves of P. capensis inhibited elastase activity by more than 90%. The methanol extract of S. brachypetala bark contained the highest anti-hyaluronidase activity (75.13 ± 7.49%) whilst the ethyl acetate extract of P. africanum bark exhibited the highest antioxidant activity (IC50: 1.99 ± 0.23 μg/ml). Conclusion The free radical scavenging activity and enzyme inhibitory activity of the plant extracts investigated suggests that they can help restore skin elasticity and thereby slow the wrinkling process. P. africanum was the plant with the most promising activity and will be subjected to further testing and isolation of the active compound/s. PMID:24188320

Differentiating School-Aged Children with and without Language Impairment Using Tense and Grammaticality Measures from a Narrative Task

ERIC Educational Resources Information Center

Guo, Ling-Yu; Schneider, Phyllis

2016-01-01

Purpose: To determine the diagnostic accuracy of the finite verb morphology composite (FVMC), number of errors per C-unit (Errors/CU), and percent grammatical C-units (PGCUs) in differentiating school-aged children with language impairment (LI) and those with typical language development (TL). Method: Participants were 61 six-year-olds (50 TL, 11…

Assessing the age of animal bones and ivories by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Sharikova, Anna; Peerzada, Lubna; Khmaladze, Alexander

2018-02-01

A fast, convenient way to determine the age of bones and ivories is important both in forensics and for classifying art objects in collections of art experts, restorers, art galleries and museums. Knowing the age of elephant tusks is also essential because there are many date-specific regulations of ivory trade. Radiocarbon dating is the standard method used to determine the age of organic materials, but it is expensive, time consuming, and damages the sample in the process. Raman spectroscopy is sensitive to rotational and vibrational molecular transitions, and also intermolecular vibrations. Therefore, it can provide information about sample make up, such as proteins and minerals, as well as detect spectral signatures associated with structural changes in molecules. Since Raman spectroscopy identifies the molecular bonds present in a sample, it is often used to determine its chemical composition. Bones and ivories contain two primary components: collagen and bioapatite. As the protein collagen deteriorates with time, its Raman signal decreases. The ratio of collagen-to-bioapatite peaks, therefore, is smaller in the older samples compared to the younger ones, providing a basis for sample dating. We employed Raman spectroscopy to non-destructively determine the age of several elephant tusk fragments. We have also used it to identify ivory imitations made of vegetable and plastic materials. Such materials have entirely different chemical composition, and their spectra are easily distinguished from those of bone and ivory. Peak fitting was employed to determine collagen and bioapatite components.

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

PubMed Central

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. PMID:27555734

34 CFR 401.21 - What selection criteria does the Secretary use?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., gender, age, or disabling condition. (2) To determine personnel qualifications, the Secretary considers... data must be broken down by sex and by occupation for which the training was provided; (3) The methods...

Effects of Aging on the Evolution of Microstructure and Mechanical Properties of an Al - Li - Cu - Mg Alloy with Ag, Zr, Mn, and Zn Additives

NASA Astrophysics Data System (ADS)

Sun, Zhong-gang; Bao, Peng-li; Ma, Chao; Chen, Jie; Guo, Xuan; Li, Hua-guan; Ling, Juan

2016-03-01

The microstructure and the post-aging hardness of an Al - Li - Cu - Mg alloy is studied by the methods of transmission electron microscopy. Tensile tests are performed. The volume fraction and the size of the particles of the δ', S and T 1 phases are shown to be dependent on the aging temperature and time. The effect of the precipitates of the δ', S and T 1 phases on the hardening of the Al - Li - Cu - Mg alloy during aging is determined.

Determination of Carbonyl Groups in Pyrolysis Bio-oils Using Potentiometric Titration: Review and Comparison of Methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Black, Stuart; Ferrell, Jack R.

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here in this study, we present a modification of the traditional carbonyl oximation procedures that results inmore » less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. Some compounds such as carbohydrates are not measured by the traditional method (modified Nicolaides method), resulting in low estimations of the carbonyl content. Furthermore, we have shown that reaction completion for the traditional method can take up to 300 hours. The new method presented here (the modified Faix method) reduces the reaction time to 2 hours, uses triethanolamine (TEA) in the place of pyridine, and requires a smaller sample size for the analysis. Carbonyl contents determined using this new method are consistently higher than when using the traditional titration methods.« less

Determination of Carbonyl Groups in Pyrolysis Bio-oils Using Potentiometric Titration: Review and Comparison of Methods

DOE PAGES

Black, Stuart; Ferrell, Jack R.

2016-01-06

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here in this study, we present a modification of the traditional carbonyl oximation procedures that results inmore » less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. Some compounds such as carbohydrates are not measured by the traditional method (modified Nicolaides method), resulting in low estimations of the carbonyl content. Furthermore, we have shown that reaction completion for the traditional method can take up to 300 hours. The new method presented here (the modified Faix method) reduces the reaction time to 2 hours, uses triethanolamine (TEA) in the place of pyridine, and requires a smaller sample size for the analysis. Carbonyl contents determined using this new method are consistently higher than when using the traditional titration methods.« less

Age as a Determinant to Select an Anesthesia Method for Tympanostomy Tube Insertion in a Pediatric Population

PubMed Central

Jung, Kihwan; Kim, Hojong

2015-01-01

Background and Objectives To evaluate the relationship between age and anesthesia method used for tympanostomy tube insertion (TTI) and to provide evidence to guide the selection of an appropriate anesthesia method in children. Subjects and Methods We performed a retrospective review of children under 15 years of age who underwent tympanostomy tube insertion (n=159) or myringotomy alone (n=175) under local or general anesthesia by a single surgeon at a university-based, secondary care referral hospital. Epidermiologic data between local and general anesthesia groups as well as between TTI and myringotomy were analyzed. Medical costs were compared between local and general anesthesia groups. Results Children who received local anesthesia were significantly older than those who received general anesthesia. Unilateral tympanostomy tube insertion was performed more frequently under local anesthesia than bilateral. Logistic regression modeling showed that local anesthesia was more frequently applied in older children (odds ratio=1.041) and for unilateral tympanostomy tube insertion (odds ratio=8.990). The cut-off value of age for local anesthesia was roughly 5 years. Conclusions In a pediatric population at a single medical center, age and whether unilateral or bilateral procedures were required were important factors in selecting an anesthesia method for tympanostomy tube insertion. Our findings suggest that local anesthesia can be preferentially considered for children 5 years of age or older, especially in those with unilateral otitis media with effusion. PMID:26185791

Alterations in lenticular proteins during ageing and selenite-induced cataractogenesis in Wistar rats

PubMed Central

Sakthivel, Muniyan; Elanchezhian, Rajan; Thomas, Philip A.

2010-01-01

Purpose To determine putative alterations in the major lenticular proteins in Wistar rats of different ages and to compare these alterations with those occurring in rats with selenite-induced cataract. Methods Lenticular transparency was determined by morphological examination using slit-lamp biomicroscopy. Alterations in lenticular protein were determined by sodium dodecyl sulfate-PAGE (SDS–PAGE) and confirmed immunologically by western blot. Results Morphological examination did not reveal observable opacities in the lenses of the rats of different age groups; however, dense nuclear opacities were noted in lenses of rats in the selenite-cataract group. Western blot assays revealed age-related changes in soluble and urea-soluble lenticular proteins. Decreased αA- and βB1-crystallins in the soluble fraction and aggregation of αA-crystallin, in addition to the degraded fragment of βB1-crystallin, in the urea-soluble fraction appeared to occur in relation to increasing age of the rats from which the lenses were taken; similarly, cytoskeletal proteins appeared to decline with increasing age. The lenses from rats in the selenite-cataract group exhibited similar changes, except that there was also high molecular weight aggregation of αA-crystallin. Conclusions The results of this study suggest that there is loss, as well as aggregation, of αA-crystallin in the aging rat lens, although there is no accompanying loss of lenticular transparency. PMID:20300567

Age determination in juvenile bobwhite quail

USGS Publications Warehouse

Petrides, G.A.; Nestler, R.B.

1943-01-01

Following methods described by Louis Bureau (1911, 1913) in France,tabulations were made (1) of the ages at which captivity-reared bob-white quail (Colinus virginianus) dropped their juvenal remiges, and (2) the rates at which post-juvenal replxcement primaries grew. These were arranged so as to permit the determination of age in healthv birds from one to five months of age. The degree of individual variation was much greater than that found by Bureau, however. and limits accuracy in age determination after the 10th week..... The post-juvenal wing molt began on the birds' 28th day and ended when the quail were 146 to 154 days old.The post-juvenal body molt was found to take place largely between the 70th and 100th days. The juvenal rectrices were renewed from the 62nd to the 122nd days, the new feathers being as long as their longest coverts when the birds were 116 days old. The color of the tarsi varied from pink, at 32 days of age, to straw color at 60 days, and yellow-gray from 83 to 180 days. At six months, the color of the beak was identical with that of adults.....Unlike several other game bird species, the flexibility of the lower jaw was not an accurate index to age in bob-whites older than 11 weeks. Rigor mortis and freezing were found to hinder the testing of this criterion.

Zircon morphology and U-Pb geochronology of seven metaluminous and peralkaline post-orogenic granite complexes of the Arabian Shield, Kingdom of Saudi Arabia

USGS Publications Warehouse

Aleinikoff, John Nicholas; Stoeser, D.B.

1988-01-01

The U-Pb zircon method was used to determine the ages of seven metaluminous-to-peralkaline post-orogenic granites located throughout the Late Proterozoic Arabian Shield of Saudi Arabia. Zircons from the metaluminous rocks are prismatic, with length-to-width ratios of about 2-4:1 and small pyramidal terminations. In contrast, zircons from three of the four peralkaline complexes either lack well developed prismatic faces (are pseudo-octahedral) or are anhedral. Some of the zircons from the peralkaline granites contain inherited radiogenic lead. This complicates interpretation of the isotopic data and. in many cases, may make the U-Pb method unsuitable for determining the age of a peralkaline granite. Zircons in the metaluminous granites do not contain inheritance and thus, best-fit chords calculated through the data have upper concordia intercepts that indicate the age of intrusion, and lower intercepts that indicate simple episodic lead loss. The results show that these granites were emplaced during multiple intrusive episodes from 670 to 510 Ma (Late Proterozoic to Cambrian).

General fusion approaches for the age determination of latent fingerprint traces: results for 2D and 3D binary pixel feature fusion

NASA Astrophysics Data System (ADS)

Merkel, Ronny; Gruhn, Stefan; Dittmann, Jana; Vielhauer, Claus; Bräutigam, Anja

2012-03-01

Determining the age of latent fingerprint traces found at crime scenes is an unresolved research issue since decades. Solving this issue could provide criminal investigators with the specific time a fingerprint trace was left on a surface, and therefore would enable them to link potential suspects to the time a crime took place as well as to reconstruct the sequence of events or eliminate irrelevant fingerprints to ensure privacy constraints. Transferring imaging techniques from different application areas, such as 3D image acquisition, surface measurement and chemical analysis to the domain of lifting latent biometric fingerprint traces is an upcoming trend in forensics. Such non-destructive sensor devices might help to solve the challenge of determining the age of a latent fingerprint trace, since it provides the opportunity to create time series and process them using pattern recognition techniques and statistical methods on digitized 2D, 3D and chemical data, rather than classical, contact-based capturing techniques, which alter the fingerprint trace and therefore make continuous scans impossible. In prior work, we have suggested to use a feature called binary pixel, which is a novel approach in the working field of fingerprint age determination. The feature uses a Chromatic White Light (CWL) image sensor to continuously scan a fingerprint trace over time and retrieves a characteristic logarithmic aging tendency for 2D-intensity as well as 3D-topographic images from the sensor. In this paper, we propose to combine such two characteristic aging features with other 2D and 3D features from the domains of surface measurement, microscopy, photography and spectroscopy, to achieve an increase in accuracy and reliability of a potential future age determination scheme. Discussing the feasibility of such variety of sensor devices and possible aging features, we propose a general fusion approach, which might combine promising features to a joint age determination scheme in future. We furthermore demonstrate the feasibility of the introduced approach by exemplary fusing the binary pixel features based on 2D-intensity and 3D-topographic images of the mentioned CWL sensor. We conclude that a formula based age determination approach requires very precise image data, which cannot be achieved at the moment, whereas a machine learning based classification approach seems to be feasible, if an adequate amount of features can be provided.

Evaluation and clinical significance of the stomach age model for evaluating aging of the stomach-a multicenter study in China

PubMed Central

2014-01-01

Background A higher prevalence of chronic atrophic gastritis (CAG) occurs in younger adults in Asia. We used Stomach Age to examine the different mechanisms of CAG between younger adults and elderly individuals, and established a simple model of cancer risk that can be applied to CAG surveillance. Methods Stomach Age was determined by FISH examination of telomere length in stomach biopsies. Δψm was also determined by flow cytometry. Sixty volunteers were used to confirm the linear relationship between telomere length and age while 120 subjects were used to build a mathematical model by a multivariate analysis. Overall, 146 subjects were used to evaluate the validity of the model, and 1,007 subjects were used to evaluate the relationship between prognosis and Δage (calculated from the mathematical model). ROC curves were used to evaluate the relationship between prognosis and Δage and to determine the cut-off point for Δage. Results We established that a tight linear relationship between the telomere length and the age. The telomere length was obvious different between patients with and without CAG even in the same age. Δψm decreased in individuals whose Stomach Age was greater than real age, especially in younger adults. A mathematical model of Stomach Age (real age + Δage) was successfully constructed which was easy to apply in clinical work. A higher Δage was correlated with a worse outcome. The criterion of Δage >3.11 should be considered as the cut-off to select the subgroup of patients who require endoscopic surveillance. Conclusion Variation in Stomach Age between individuals of the same biological age was confirmed. Attention should be paid to those with a greater Stomach Age, especially in younger adults. The Δage in the Simple Model can be used as a criterion to select CAG patients for gastric cancer surveillance. PMID:25057261

Tree regeneration response to the group selection method in southern Indiana

Treesearch

Dale R. Weigel; George R. Parker

1997-01-01

Tree regeneration response following the use of the group selection method was studied within 36 group openings on the Naval Surface Warfare Center, Crane Division in south central Indiana. Two different aspects and three time periods since cutting were examined. The objectives were to determine whether aspect, age, species group, location within the opening, or their...

Determination of the mechanical integrity of polyvinylidene difluoride in LiNi1/3Co1/3Mn1/3O2 electrodes for lithium ion batteries by use of the micro-indentation technique

NASA Astrophysics Data System (ADS)

Wendt, Christian; Niehoff, Philip; Winter, Martin; Schappacher, Falko M.

2018-07-01

Understanding the mechanical aging of lithium ion batteries influencing the binder stability is of particular interest for enhanced battery life. In this study we present an indentation method to investigate the changes in the elasticity of PVdF in NCM electrodes with high reproducibility. To determine changes in elasticity by calculating the indentation work (ηit), a 50 μm flat punch indenter was used. In addition, a drying procedure for DMC washed samples was evaluated to reduce the effect of the washing procedure on the elasticity due to swelling of the binder. NCM electrodes soaked with electrolyte and electrodes after formation were investigated, showing a significant decrease in elasticity due to the contact with the LiPF6 containing organic carbonate solvent based electrolyte and due to the electrochemical formation procedure. Further electrochemical aging reduced the elasticity to nearly ≈50% compared to the pristine electrode. Method development and the obtained results are discussed in detail. The developed method provides a low standard deviation and high reproducibility. Hence, it is a valid methodology for the quantification of related aging mechanisms taking place in lithium ion batteries.

[Epidemiology of arbovirus diseases: use and value of physiologic age determination of female mosquito vectors].

PubMed

Mondet, B

1996-01-01

The physiological age of Yellow Fever Aedes females in Africa was studied during four years, from 1988 to 1992. We used a method, according to Polovodova's method, which looks for the "yellow body" under natural light. Those yellow bodies exist in the old females, the "parous" ones, and not in the young females, the "nulliparous" ones. We present some results to illustrate the interest of studying the physiological age of mosquitoes in the epidemiology of the arboviral diseases. The transmission risk, in relation with abundance and parity rate was illustrated, in particular for Aedes africanus and Aedes luteocephalus, which is useful to compare species, or with a given species, to compare periods. The parity rate of Aedes furcifer females was studied on 6 points along a transect between a forest and a village. The rate and the abundance of the females caught on human bates are inversely proportional. The parity rate is minimum in the canopy forest (about 50%) and maximum inside a house (100%). The rains have different consequences on the species, according to the period of fall. At the beginning of the dry season, they bring about hatching, but not at the end of the dry season. Massive hatching, will occur just at the beginning of the rainy season, some weeks later. Studying the physiological age of Ae. africanus females, the number of nulliparous is not related to the rain. That means a possibility of "natural" hatching for part of the eggs. Among the female of the dry season, young females are found, which is important for the transmission capacity. The method, described herein, to determine the physiological age is perfectly applicable to the Yellow Fever vector Haemagogus janthinomys in Southern America. But for the Dengue vectors Aedes aegypti and probably Aedes albopictus, the Detinova's method seems better. Actually, it seems important to study the physiological age of the vectors Ae. aegypti and Ae. albopictus, as well as the evolution of the physiological age in space and time, in order to better know the epidemiology of dengue in Southern America.

Improvement of the linear polarization resistance method for testing steel corrosion inhibitors

NASA Astrophysics Data System (ADS)

Faritov, A. T.; Rozhdestvenskii, Yu. G.; Yamshchikova, S. A.; Minnikhanova, E. R.; Tyusenkov, A. S.

2016-11-01

The linear polarization resistance method is used to improve the technique of corrosion control in liquid conducting according to GOST 9.514-99 (General Corrosion and Aging Protection System. Corrosion Inhibitors for Metals in Water Systems. Electrochemical Method of Determining the Protective Ability). Corrosion monitoring is shown to be performed by electronic devices with real-time data transfer to industrial controllers and SCADA systems.

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

PubMed

Mohammed, Rezwana Begum; Koganti, Ravichandra; Kalyan, Siva V; Tircouveluri, Saritha; Singh, Johar Rajvinder; Srinivasulu, Enganti

2014-09-01

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. 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. 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. 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. 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.

Urinary iodine: comparison of a simple method for its determination in microplates with measurement by inductively-coupled plasma mass spectrometry

PubMed Central

Haap, Michael; Roth, Heinz Jürgen; Huber, Thomas; Dittmann, Helmut; Wahl, Richard

2017-01-01

The aim of our study was to develop and validate an inexpensive, rapid, easy to use quantitative method to determine urinary iodine without major procurement costs for equipment. The rationale behind introducing this method is the increasing demand for urinary iodine assessments. Our study included 103 patients (76 female, 27 male), age (arithmetic mean) 52 ± 17.3 years. Urinary iodine was determined in microplates by a modification of the Sandell-Kolthoff reaction. The results were compared with inductively-coupled plasma mass spectrometry (ICP-MS) for iodine, considered as reference method. Geometric mean of urinary iodine determined by the Sandell-Kolthoff reaction method was 62.69 μg/l (95% confidence interval 53.16–73.92) whereas by the ICP-MS method it was 65.53 μg/l (95% confidence interval 54.77–78.41). Passing-Bablok regression equations for both methods gave y = 3.374 + 0.873x (y: Sandell-Kolthoff method, x: ICP-MS). Spearman´s correlation coefficient was 0.981, indicating a very high degree of agreement between the two methods. Bland-Altman plots showed no significant systematic difference between the two methods. The modified Sandell-Kolthoff method using microtiter plate technique presented here is a simple, inexpensive semi-automated method to determine urinary iodine with very little toxic waste. Comparison with the ICP-MS-technique yielded a good agreement between the two methods. PMID:28045077

Star clusters: age, metallicity and extinction from integrated spectra

NASA Astrophysics Data System (ADS)

González Delgado, Rosa M.; Cid Fernandes, Roberto

2010-01-01

Integrated optical spectra of star clusters in the Magellanic Clouds and a few Galactic globular clusters are fitted using high-resolution spectral models for single stellar populations. The goal is to estimate the age, metallicity and extinction of the clusters, and evaluate the degeneracies among these parameters. Several sets of evolutionary models that were computed with recent high-spectral-resolution stellar libraries (MILES, GRANADA, STELIB), are used as inputs to the starlight code to perform the fits. The comparison of the results derived from this method and previous estimates available in the literature allow us to evaluate the pros and cons of each set of models to determine star cluster properties. In addition, we quantify the uncertainties associated with the age, metallicity and extinction determinations resulting from variance in the ingredients for the analysis.

Adolescents’ Use of Care for Behavioral and Emotional Problems: Types, Trends, and Determinants

PubMed Central

Reijneveld, Sijmen A.; Wiegersma, P. Auke; Ormel, Johan; Verhulst, Frank C.; Vollebergh, Wilma A. M.; Jansen, Danielle E. M. C.

2014-01-01

Objective While adolescents use various types of care for behavioral and emotional problems, evidence on age trends and determinants per type is scarce. We aimed to assess use of care by adolescents because of behavioral and emotional problems, overall and by type, and its determinants, for ages 10–19 years. Methods We obtained longitudinal data on 2,230 adolescents during ages 10–19 from four measurements regarding use of general care and specialized care (youth social care and mental healthcare) in the preceding 6 months, the Child Behavior Checklist (CBCL) and Youth Self-Report, and child and family characteristics. We analyzed data by multilevel logistic regression. Results Overall rates of use increased from 20.1% at age 10/11 to 32.2% at age 19: general care was used most. At age 10/11 use was higher among boys, at age 19 among girls. Use of general care increased for both genders, whereas use of specialized care increased among girls but decreased among boys. This differential change was associated with CBCL externalizing and internalizing problems, school problems, family socioeconomic status, and parental divorce. Preceding CBCL problems predicted more use: most for mental health care and least for general care. Moreover, general care was used more frequently by low and medium socioeconomic status families, with odds ratios (95%-confidence intervals): 1.52 (1.23;1.88) and 1.40 (1.17;1.67); youth social care in case of parental divorce, 2.07 (1.36;3.17); and of special education, 2.66 (1.78;3.95); and mental healthcare in case of special education, 2.66 (1.60;4.51). Discussion Adolescents with behavioral and emotional problems use general care most frequently. Overall use increases with age. Determinants of use vary per type. PMID:24699408

Manuka honey protects middle-aged rats from oxidative damage.

PubMed

Jubri, Zakiah; Rahim, Noor Baitee Abdul; Aan, Goon Jo

2013-11-01

This study aimed to determine the effect of manuka honey on the oxidative status of middle-aged rats. Twenty-four male Sprague-Dawley rats were divided into young (2 months) and middle-aged (9 months) groups. They were further divided into two groups each, which were either fed with plain water (control) or supplemented with 2.5 g/kg body weight of manuka honey for 30 days. The DNA damage level was determined via the comet assay, the plasma malondialdehyde level was determined using high performance liquid chromatography, and the antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, glutathione peroxidase and catalase) were determined spectrophotometrically in the erythrocytes and liver. The antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl and ferric reducing/antioxidant power assays, and the total phenolic content of the manuka was analyzed using UV spectrophotometry and the Folin-Ciocalteu method, respectively. Supplementation with manuka honey reduced the level of DNA damage, the malondialdehyde level and the glutathione peroxidase activity in the liver of both the young and middle-aged groups. However, the glutathione peroxidase activity was increased in the erythrocytes of middle-aged rats given manuka honey supplementation. The catalase activity was reduced in the liver and erythrocytes of both young and middle-aged rats given supplementation. Manuka honey was found to have antioxidant activity and to have a high total phenolic content. These findings showed a strong correlation between the total phenolic content and antioxidant activity. Manuka honey reduces oxidative damage in young and middle-aged rats; this effect could be mediated through the modulation of its antioxidant enzyme activities and its high total phenolic content. Manuka honey can be used as an alternative supplement at an early age to improve the oxidative status.

Fetal exposure to propoxur and abnormal child neurodevelopment at 2 years of age

PubMed Central

Ostrea, Enrique M.; Reyes, Alexis; Villanueva-Uy, Esterlita; Pacifico, Rochelle; Benitez, Bernadette; Ramos, Essie; Bernardo, Rommel C.; Bielawski, Dawn M.; Delaney-Black, Virginia; Chiodo, Lisa; Janisse, James J.; Ager, Joel W.

2012-01-01

Objective Our aim was to determine the effects of fetal exposure to propoxur and pyrethroids, on child neurodevelopment at 2 years of age. Patients and Methods Mothers were prospectively recruited during mid-pregnancy in Bulacan, Philippines where multiple pesticides including propoxur, cyfluthrin, chlorpyrifos, cypermethrin, pretilachlor, bioallethrin, malathion, diazinon and transfluthrin are used. To detect prenatal exposure to these pesticides, maternal hair and blood, infant’s hair, cord blood, and meconium were analyzed for the pesticides by gas chromatography/mass spectrometry. Infants were examined at 2 years of age with 95.1% follow up rate and their neurodevelopment outcome was assessed by the Griffiths Mental Developmental Scale (N=754). Results Meconium analysis was the most sensitive method to detect fetal exposure to pesticides and exposure was highest for propoxur (21.3%) and the grouped pyrethroids (2.5% - bioallethrin, transfluthrin, cyfluthrin and cypermethrin). Path analysis modeling was performed to determine the effects of fetal exposure to propoxur and pyrethroids on the child’s neurodevelopment at 24 months of age while controlling for confounders. Only singletons and those with complete data for the path analysis were included (N=696). Using a path analysis model, there was a significant negative (β= −0.14, p<0.001) relationship between prenatal pesticide exposure to propoxur and motor development at 2 years of age after controlling for confounders, e.g., infant gender, socioeconomic status, maternal intelligence, home stimulation (HOME), postnatal exposure to propoxur and blood lead level at 2 years of age. Conclusion At 2 years of age, prenatal exposure to propoxur was associated with poorer motor development in children. PMID:22155319

New Method for Determining the Relative Stand Density of Forest Inventory Plots

Treesearch

Christopher W. Woodall; Patrick D. Miles

2006-01-01

Determining the relative density of Forest Inventory and Analysis plots is complicated by the various species and tree size combinations in the Nation?s forested ecosystems. Stand density index (SDI), although developed for use in even-aged monocultures, has been used for stand density assessment in largescale forest inventories. To improve application of SDI in uneven...

Rurality and Other Determinants of Early Colorectal Cancer Diagnosis in Nebraska: A 6-Year Cancer Registry Study, 1998-2003

ERIC Educational Resources Information Center

Sankaranarayanan, Jayashri; Watanabe-Galloway, Shinobu; Sun, Junfeng; Qiu, Fang; Boilesen, Eugene; Thorson, Alan G.

2009-01-01

Background: There are no studies of rurality, and other determinants of colorectal cancer (CRC) stage at diagnosis with population-based data from the Midwest. Methods: This retrospective study identified, incident CRC patients, aged 19 years and older, from 1998-2003 Nebraska Cancer Registry (NCR) data. Using federal Office of Management and…

Children's Performance in Complex Listening Conditions: Effects of Hearing Loss and Digital Noise Reduction

ERIC Educational Resources Information Center

Pittman, Andrea

2011-01-01

Purpose: To determine the effect of hearing loss (HL) on children's performance for an auditory task under demanding listening conditions and to determine the effect of digital noise reduction (DNR) on that performance. Method: Fifty children with normal hearing (NH) and 30 children with HL (8-12 years of age) categorized words in the presence of…

Association between growth stunting with dental development and skeletal maturation stage.

PubMed

Flores-Mir, Carlos; Mauricio, Franco Raul; Orellana, Maria Fernanda; Major, Paul William

2005-11-01

The aim of this study was to determine the influence of growth stunting on the maturation stage of the medium phalanx of the third finger (MP3) and the dental development of the left mandibular canine in 280 high school children (140 stunted and 140 normal controls; equally distributed by sex) between 9.5 and 16.5 years of age, from a representative Peruvian school. Periapical radiographs of the MP3 from the left hand were used to determine the skeletal maturity stage, according to an adaptation of the Hägg and Taranger method. Panoramic radiographs were used to determine the dental maturity stage of the lower left canine, according to Demirjian method. Stunting was determined by relating height and age, according to the World Health Organization recommendations. There was no statistically significant difference in the skeletal maturation stage (P = .134) and the dental development stage (P = .497) according to nutritional status, even when considering different age groups (P > .183). A high correlation (r = 0.85) was found between both maturity indicators regardless of the nutritional status (growth stunted, r = 0.855 and normal controls, r = 0.863) or sex (boys, r = 0.809 and girls, r = 0.892). When skeletal level was considered, correlations values were similar between advanced (r = 0.903) and average (r = 0.895) maturers but lower (r = 0.751) for delayed maturers. Growth stunting was not associated with dental development and skeletal maturity stages in Peruvian school children.

Hoarseness in School-Aged Children and Effectiveness of Voice Therapy in International Classification of Functioning Framework.

PubMed

Akın Şenkal, Özgül; Özer, Cem

2015-09-01

The hoarseness in school-aged children disrupts the educational process because it affects the social progress, communication skills, and self-esteem of children. Besides otorhinolaryngological examination, the first treatment option is voice therapy when hoarseness occurs. The aim of the study was to determine the factors increasing the hoarseness in school-aged children by parental interview and to know preferable voice therapy on school-aged children within the frame of International Classification of Functioning (ICF). Retrospective analysis of data gathered from patient files. A total of 75 children (56 boys and 19 girls) were examined retrospectively. The age range of school-aged children is 7-14 years and average is 10.86 ± 2.51. A detailed history was taken from parents of children involved in this study. Information about vocal habits of children was gathered within the frame of ICF and then the voice therapies of children were started by scheduling appointments by an experienced speech-language pathologist. The differences between before and after voice therapy according to applied voice therapy methods, statistically significant differences were determined between maximum phonation time values and s/z rate. The relationship between voice therapy sessions and s/z rate with middle degree significance was found with physiological voice therapy sessions. According to ICF labels, most of voice complaints are matching with "body functions" and "activity and limitations." The appropriate voice therapy methods for hoarseness in school-aged children must be chosen and applied by speech-language therapists. The detailed history, which is received from family during the examination, within the frame of ICF affects the processes of choosing the voice therapy method and application of them positively. Child's family is very important for a successful management. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Implications for would healing of patient age and time elapsed since burn injury.

PubMed

Mountford, E M; Blight, A; Cheshire, I M

1995-01-01

To determine the relationship between growth potential in culture and the age of the patient, skin biopsies were obtained from over 60 patients of varying ages. The relationship between the length of time elapsed since burn injury and growth potential was also examined, using biopsies obtained from patients with burns during their treatment. Keratinocytes were extracted from biopsies and assessed for colony-forming ability by standard methods. Repeated subculture of cells was undertaken to determine the reproductive capacity of cells in vitro. Age had no effect on the colony-forming ability of keratinocytes in primary culture; however age did affect the total number of generations achieved by these cells. The growth potential of keratinocytes from patients with severe burns showed considerable variation according to the amount of time which had elapsed since the injury. This was most apparent around one week post-burn. These results need to be investigated further to understand their clinical implications. The study provides an insight into the influence of age and physiological response on the wound healing process in burn injuries.

On the ages of resonant, eroded and fossil asteroid families

NASA Astrophysics Data System (ADS)

Milani, Andrea; Knežević, Zoran; Spoto, Federica; Cellino, Alberto; Novaković, Bojan; Tsirvoulis, Georgios

2017-05-01

In this work we have estimated 10 collisional ages of 9 families for which for different reasons our previous attempts failed. In general, these are difficult cases that required dedicated effort, such as a new family classifications for asteroids in mean motion resonances, in particular the 1/1 and 2/1 with Jupiter, as well as a revision of the classification inside the 3/2 resonance. Of the families locked in mean motion resonances, by employing a numerical calibration to estimate the Yarkovsky effect in proper eccentricity, we succeeded in determining ages of the families of (1911) Schubart and of the "super-Hilda" family, assuming this is actually a severely eroded original family of (153) Hilda. In the Trojan region we found families with almost no Yarkovsky evolution, for which we could compute only physically implausible ages. Hence, we interpreted their modest dispersions of proper elements as implying that the Trojan asteroid families are fossil families, frozen at their proper elements determined by the original ejection velocity field. We have found a new family, among the Griquas locked in the 2/1 resonance with Jupiter, the family of (11097) 1994 UD1. We have estimated the ages of 6 families affected by secular resonances: families of (5) Astraea, (25) Phocaea, (283) Emma, (363) Padua, (686) Gersuind, and (945) Barcelona. By using in all these cases a numerical calibration method, we have shown that the secular resonances do not affect significantly the secular change of proper a. We have confirmed the existence of the family resulting from cratering on (5) Astraea by computing a new set of resonant proper elements adapted to the resonance g +g5 - 2g6 : this new family has a much larger membership and has a shape compatible with simple collisional models. For the family of (145) Adeona we could estimate the age only after removal of a number of assumed interlopers. With the present paper we have concluded the series dedicated to the determination of asteroid ages with a uniform method. Overall we computed 53 ages for a total of 49 families. For the future work there remain families too small at present to provide reliable estimates, as well as some complex families (221, 135, 298) which may have more ages than we could currently estimate. Future improvement of some already determined family ages is also possible by increasing family membership, revising the calibrations, and using more reliable physical data.

Optimization and validation of Folin-Ciocalteu method for the determination of total polyphenol content of Pu-erh tea.

PubMed

Musci, Marilena; Yao, Shicong

2017-12-01

Pu-erh tea is a post-fermented tea that has recently gained popularity worldwide, due to potential health benefits related to the antioxidant activity resulting from its high polyphenolic content. The Folin-Ciocalteu method is a simple, rapid, and inexpensive assay widely applied for the determination of total polyphenol content. Over the past years, it has been subjected to many modifications, often without any systematic optimization or validation. In our study, we sought to optimize the Folin-Ciocalteu method, evaluate quality parameters including linearity, precision and stability, and then apply the optimized model to determine the total polyphenol content of 57 Chinese teas, including green tea, aged and ripened Pu-erh tea. Our optimized Folin-Ciocalteu method reduced analysis time, allowed for the analysis of a large number of samples, to discriminate among the different teas, and to assess the effect of the post-fermentation process on polyphenol content.

Radiometric ages for basement rocks from the Emperor Seamounts, ODP Leg 197

NASA Astrophysics Data System (ADS)

Duncan, Robert A.; Keller, Randall A.

2004-08-01

The Hawaiian-Emperor seamount chain is the "type" example of an age-progressive, hot spot-generated intraplate volcanic lineament. However, our current knowledge of the age distribution within this province is based largely on radiometric ages determined several decades ago. Improvements in instrumentation, sample preparation methods, and new material obtained by recent drilling warrant a reexamination of the age relations among the older Hawaiian volcanoes. We report new age determinations (40Ar-39Ar incremental heating method) on whole rocks and feldspar separates from Detroit (Sites 1203 and 1204), Nintoku (Site 1205), and Koko (Site 1206) Seamounts (Ocean Drilling Program (ODP) Leg 197) and Meiji Seamount (Deep Sea Drilling Project (DSDP) Leg 19, Site 192). Plateaus in incremental heating age spectra for Site 1203 lava flows give a mean age of 75.8 ± 0.6 (2σ) Ma, which is consistent with the normal magnetic polarity directions observed and biostratigraphic age assignments. Site 1204 lavas produced discordant spectra, indicating Ar loss by reheating and K mobilization. Six plateau ages from lava flows at Site 1205 give a mean age of 55.6 ± 0.2 Ma, corresponding to Chron 24r. Drilling at Site 1206 intersected a N-R-N magnetic polarity sequence of lava flows, from which six plateau ages give a mean age of 49.1 ± 0.2 Ma, corresponding to the Chron 21n-22r-22n sequence. Plateau ages from two feldspar separates and one lava from DSDP Site 192 range from 34 to 41 Ma, significantly younger than the Cretaceous age of overlying sediments, which we relate to postcrystallization K mobilization. Combined with new dating results from Suiko Seamount (DSDP Site 433) and volcanoes near the prominent bend in the lineament [, 2002], the overall trend is increasing volcano age from south to north along the Emperor Seamounts, consistent with the hot spot model. However, there appear to be important departures from the earlier modeled simple linear age progression, which we relate to changes in Pacific plate motion and the rate of southward motion of the Hawaiian hot spot.

Determinants of modern family planning use among women of reproductive age in the Nkwanta district of Ghana: a case-control study.

PubMed

Eliason, Sebastian; Awoonor-Williams, John K; Eliason, Cecilia; Novignon, Jacob; Nonvignon, Justice; Aikins, Moses

2014-08-13

Average contraceptive prevalence rate in the Nkwanta district of Ghana was estimated to be 6.2% relative to the national average at the time, of 19%. While several efforts had been made to improve family planning in the country, the district still had very low use of modern family planning methods. This study sought to determine the factors that influenced modern family planning use in general and specifically, the factors that determined the consistently low use of modern family planning methods in the district. A case-control study was conducted in the Nkwanta district of Ghana to determine socio-economic, socio-cultural and service delivery factors influencing family planning usage. One hundred and thirty cases and 260 controls made up of women aged 15-49 years were interviewed using structured questionnaires. A logistic regression was fitted. Awareness and knowledge of modern family planning methods were high among cases and controls (over 90%). Lack of formal education among women, socio-cultural beliefs and spousal communication were found to influence modern family planning use. Furthermore, favourable opening hours of the facilities and distance to health facilities influenced the use of modern contraceptives. While modern family planning seemed to be common knowledge among these women, actual use of such contraceptives was limited. There is need to improve use of modern family planning methods in the district. In addition to providing health facilities and consolidating close-to-client service initiatives in the district, policies directed towards improving modern family planning method use need to consider the influence of formal education. Promoting basic education, especially among females, will be a crucial step as the district is faced with high levels of school dropout and illiteracy rates.

A 21-Week Bone Deposition Promoting Exercise Programme Increases Bone Mass in Young People with Down Syndrome

ERIC Educational Resources Information Center

Gonzalez-Aguero, Alejandro; Vicente-Rodriguez, German; Gomez-Cabello, Alba; Ara, Ignacio; Moreno, Luis A.; Casajus, Jose A.

2012-01-01

Aim: To determine whether the bone mass of young people with Down syndrome may increase, following a 21-week conditioning training programme including plyometric jumps. Method: Twenty-eight participants with Down syndrome (13 females, 15 males) aged 10 to 19 years were divided into exercise (DS-E; n = 14; eight females, six males mean age 13y 8mo,…

Age-Related Benefits of Digital Noise Reduction for Short-Term Word Learning in Children with Hearing Loss

ERIC Educational Resources Information Center

Pittman, Andrea

2011-01-01

Purpose: To determine the rate of word learning for children with hearing loss (HL) in quiet and in noise compared to normal-hearing (NH) peers. The effects of digital noise reduction (DNR) were examined for children with HL. Method: Forty-one children with NH and 26 children with HL were grouped by age (8-9 years and 11-12 years). The children…

Numerical dating of a Late Quaternary spit-shoreline complex at the northern end of Silver Lake playa, Mojave Desert, California: A comparison of the applicability of radiocarbon, luminescence, terrestrial cosmogenic nuclide, electron spin resonance, U-series and amino acid racemization methods

USGS Publications Warehouse

Owen, L.A.; Bright, Jordon; Finkel, R.C.; Jaiswal, M.K.; Kaufman, D.S.; Mahan, S.; Radtke, U.; Schneider, J.S.; Sharp, W.; Singhvi, A.K.; Warren, C.N.

2007-01-01

A Late Quaternary spit-shoreline complex on the northern shore of Pleistocene Lake Mojave of southeastern California, USA was studied with the goal of comparing accelerator mass spectrometry (AMS) radiocarbon, luminescence, electron spin resonance (ESR), terrestrial cosmogenic radionuclide (TCN) surface exposure, amino acid racemization (AAR) and U-series dating methods. The pattern of ages obtained by the different methods illustrates the complexity of processes acting in the lakeshore environment and highlights the utility of a multi-method approach. TCN surface exposure ages (mostly ???20-30 ka) record the initial erosion of shoreline benches, whereas radiocarbon ages on shells (determined in this and previous studies) within the spit, supported by AAR data, record its construction at fluctuating lake levels from ???16 to 10 ka. Luminescence ages on spit sediment (???6-7 ka) and ESR ages on spit shells (???4 ka) are anomalously young relative to radiocarbon ages of shells within the same deposits. The significance of the surprisingly young luminescence ages is not clear. The younger ESR ages could be a consequence of post-mortem enrichment of U in the shells. High concentrations of detrital thorium in tufa coating spit gravels inhibited the use of single-sample U-series dating. Detailed comparisons such as this provide one of the few means of assessing the accuracy of Quaternary dating techniques. More such comparisons are needed. ?? 2007 Elsevier Ltd and INQUA.

Synergies Between Asteroseismology and Exoplanetary Science

NASA Astrophysics Data System (ADS)

Huber, Daniel

Over the past decade asteroseismology has become a powerful method to systematically characterize host stars and dynamical architectures of exoplanet systems. In this contribution I review current key synergies between asteroseismology and exoplanetary science such as the precise determination of planet radii and ages, the measurement of orbital eccentricities, stellar obliquities and their impact on hot Jupiter formation theories, and the importance of asteroseismology on spectroscopic analyses of exoplanet hosts. I also give an outlook on future synergies such as the characterization of sub-Neptune-size planets orbiting solar-type stars, the study of planet populations orbiting evolved stars, and the determination of ages of intermediate-mass stars hosting directly imaged planets.

Age estimation based on aspartic acid racemization in human sclera.

PubMed

Klumb, Karolin; Matzenauer, Christian; Reckert, Alexandra; Lehmann, Klaus; Ritz-Timme, Stefanie

2016-01-01

Age estimation based on racemization of aspartic acid residues (AAR) in permanent proteins has been established in forensic medicine for years. While dentine is the tissue of choice for this molecular method of age estimation, teeth are not always available which leads to the need to identify other suitable tissues. We examined the suitability of total tissue samples of human sclera for the estimation of age at death. Sixty-five samples of scleral tissue were analyzed. The samples were hydrolyzed and after derivatization, the extent of aspartic acid racemization was determined by gas chromatography. The degree of AAR increased with age. In samples from younger individuals, the correlation of age and D-aspartic acid content was closer than in samples from older individuals. The age-dependent racemization in total tissue samples proves that permanent or at least long-living proteins are present in scleral tissue. The correlation of AAR in human sclera and age at death is close enough to serve as basis for age estimation. However, the precision of age estimation by this method is lower than that of age estimation based on the analysis of dentine which is due to molecular inhomogeneities of total tissue samples of sclera. Nevertheless, the approach may serve as a valuable alternative or addition in exceptional cases.

Reflectance-based determination of age and species of blowfly puparia.

PubMed

Voss, Sasha C; Magni, Paola; Dadour, Ian; Nansen, Christian

2017-01-01

Forensic entomology is primarily concerned with the estimation of time since death and involves determination of the age of immature insects colonising decomposing remains. Accurate age determination of puparia is usually accomplished by dissection, which means destructive sampling of evidence. As part of improving abilities to correctly identify species and developmental age, it is highly desirable to have available non-destructive methods. In this study, we acquired external hyperspectral imaging (HSI) data (77 spectral bands, 389-892 nm) from the dorsal and ventral sides of individual puparia of two species of blowfly (Diptera: Calliphoridae), Calliphora dubia Macquart 1855 and Chrysomya rufifacies Macquart 1842. Puparia were dissected to determine the presence/absence of eight internal morphological development characteristics (legs, wings, labella, abdominal segments, antennae, thoracic bristles, orbital/facial bristles and eye colour and arista). Based on linear discriminant analysis and independent validation of HSI data, reflectance features from puparia could be used to successfully (1) distinguish the two species (classification accuracy = 92.5 %), (2) differentiate dorsal and ventral sides of puparia (classification accuracy C. dubia = 81.5 %; Ch. rufifacies = 89.2 %) and (3) predict the presence of these morphological characteristics and therefore the developmental stage of puparia (average classification accuracy using dorsal imaging: C. dubia = 90.3 %; Ch. rufifacies = 94.0 %). The analytical approach presented here provides proof of concept for a direct puparial age relationship (i.e. days since the onset of pupation) between external puparial reflectance features and internal morphological development. Furthermore, this approach establishes the potential for further refinement by using a non-invasive technique to determine the age and developmental stage of blowflies of forensic importance.

[Proportion of breast cancer in women aged 50 to 69 years from Girona, Spain, according to detection method].

PubMed

Puig-Vives, Montse; Osca-Gelis, Gemma; Camprubí-Font, Carla; Vilardell, M Loreto; Izquierdo, Angel; Marcos-Gragera, Rafael

2014-10-07

The aim of this study was to determine the tumor stage, the proportion of cases and the age specific rate of breast cancer (BC) cases according to detection method. Cases of women aged 50 to 69 years diagnosed with BC in the Girona province during 1999-2006 were extracted from the population-based Girona Cancer Registry (n=1,254). BC was classified by detection method: screen-detected cancer, interval cancer and others. Proportion of cases and age-specific incidence were calculated according to detection method. During the period 2002-2006, the proportion of screen-detected cancers, interval cancers and other cancers were 42.2%, 5.8% and 52.2%, respectively. After implementation of the early detection of breast cancer program (PDPCM), the incidence of screen-detected cases raised; thereafter, interval cancers also increased and the rate of other cancers decreased. In the Girona province during the fully implemented PDPCM period (2002-2006), interval cancers represented a low proportion (5.8%) of women diagnosed with BC at 50 to 69 years old. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Environmental impact to multimedia systems on the example of fingerprint aging behavior at crime scenes

NASA Astrophysics Data System (ADS)

Merkel, Ronny; Breuhan, Andy; Hildebrandt, Mario; Vielhauer, Claus; Bräutigam, Anja

2012-06-01

In the field of crime scene forensics, current methods of evidence collection, such as the acquisition of shoe-marks, tireimpressions, palm-prints or fingerprints are in most cases still performed in an analogue way. For example, fingerprints are captured by powdering and sticky tape lifting, ninhydrine bathing or cyanoacrylate fuming and subsequent photographing. Images of the evidence are then further processed by forensic experts. With the upcoming use of new multimedia systems for the digital capturing and processing of crime scene traces in forensics, higher resolutions can be achieved, leading to a much better quality of forensic images. Furthermore, the fast and mostly automated preprocessing of such data using digital signal processing techniques is an emerging field. Also, by the optical and non-destructive lifting of forensic evidence, traces are not destroyed and therefore can be re-captured, e.g. by creating time series of a trace, to extract its aging behavior and maybe determine the time the trace was left. However, such new methods and tools face different challenges, which need to be addressed before a practical application in the field. Based on the example of fingerprint age determination, which is an unresolved research challenge to forensic experts since decades, we evaluate the influences of different environmental conditions as well as different types of sweating and their implications to the capturing sensory, preprocessing methods and feature extraction. We use a Chromatic White Light (CWL) sensor to exemplary represent such a new optical and contactless measurement device and investigate the influence of 16 different environmental conditions, 8 different sweat types and 11 different preprocessing methods on the aging behavior of 48 fingerprint time series (2592 fingerprint scans in total). We show the challenges that arise for such new multimedia systems capturing and processing forensic evidence

Characteristics of Females Who Use Contraception at Coitarche: An Analysis of the National Survey of Family Growth 2006-2010 Database.

PubMed

Lee, Jinhyung; Berenson, Abbey B; Patel, Pooja R

2015-12-01

To determine demographical and behavioral characteristics associated with contraceptive use at coitarche, or first sexual experience, to determine which populations are at greatest risk of contraceptive nonuse during early sexual experiences. Cross-sectional study. We used the National Survey of Family Growth 2006-2010 database to abstract pertinent variables, including race, highest education, annual family income, parental living situation, importance of religion, age at coitarche, number of sexual partners, type of first contraception, and source of first contraception. Generalized linear models with logit link and binomial distribution were applied to examine the association between use of contraceptive methods at coitarche and the variables abstracted. Of the 5931 female participants included in the study, 1071 (18%) did not use contraceptive methods at coitarche. Only 199 (2%) of the female participants included in this study used the more reliable hormonal contraceptive methods at coitarche. Black females were significantly more likely than white females to use contraceptive methods at coitarche (p < 0.01). Females who initiated coitarche from 16 to 20 years of age were significantly more likely to use contraception at coitarche than females who had their first sexual experience at less than 16 years of age (p < 0.001). Females with greater educational background and greater family income were also significantly more likely to use contraception at coitarche (p < 0.001). Finally, females who obtained their first contraceptive methods from a spouse, partner, or friend were more likely to use contraception at coitarche than females who obtained their first method from a medical facility (p < 0.001). This study highlights several key differences between females who use contraceptive methods at coitarche versus those who do not. Greater effort needs to be focused on increasing access to more reliable contraceptive methods for young females, as females who obtain methods from nonmedical facilities are more likely to use contraceptive methods at coitarche.

A simple-rapid method to separate uranium, thorium, and protactinium for U-series age-dating of materials.

PubMed

Knight, Andrew W; Eitrheim, Eric S; Nelson, Andrew W; Nelson, Steven; Schultz, Michael K

2014-08-01

Uranium-series dating techniques require the isolation of radionuclides in high yields and in fractions free of impurities. Within this context, we describe a novel-rapid method for the separation and purification of U, Th, and Pa. The method takes advantage of differences in the chemistry of U, Th, and Pa, utilizing a commercially-available extraction chromatographic resin (TEVA) and standard reagents. The elution behavior of U, Th, and Pa were optimized using liquid scintillation counting techniques and fractional purity was evaluated by alpha-spectrometry. The overall method was further assessed by isotope dilution alpha-spectrometry for the preliminary age determination of an ancient carbonate sample obtained from the Lake Bonneville site in western Utah (United States). Preliminary evaluations of the method produced elemental purity of greater than 99.99% and radiochemical recoveries exceeding 90% for U and Th and 85% for Pa. Excellent purity and yields (76% for U, 96% for Th and 55% for Pa) were also obtained for the analysis of the carbonate samples and the preliminary Pa and Th ages of about 39,000 years before present are consistent with (14)C-derived age of the material. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed

Alkass, Kanar; Buchholz, Bruce A; Ohtani, Susumu; Yamamoto, Toshiharu; Druid, Henrik; Spalding, Kirsty L

2010-05-01

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. 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 study, we analyzed teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbon analysis is that aboveground testing of nuclear weapons during the cold war (1955-1963) caused an extreme increase in global levels of carbon-14 ((14)C), which has 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 10 of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well (R(2) = 0.66, p < 0.05). Radiocarbon analysis showed an excellent precision with an overall absolute error of 1.0 +/- 0.6 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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alkass, K; Buchholz, B A; Ohtani, S

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 radiocarbonmore » 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.« less

Applications of Cosmogenic He-3 and Ne-21 Dating to Glacial Moraines in Antarctica and California

NASA Astrophysics Data System (ADS)

Sams, S.; Morgan, D. J.; Balco, G.; Putkonen, J.; Bibby, T.

2015-12-01

The depositional age of moraines can be determined through cosmogenic nuclide exposure dating. These ages are useful in establishing a glacial history of an area and ascribing age constraints to transport processes. Be-10 is the most common nuclide used for exposure dating today, but this method is both expensive and time consuming because it requires analysis by accelerator mass spectrometry (AMS). He-3 and Ne-21 can be analyzed using noble gas mass spectrometry, which is more cost efficient than AMS and requires less chemical preparation. We collected samples from areas in Moraine Canyon, Antarctica (86.10° S, 157.75° W), which is a dry valley in the Transantarctic Mountains. Dolerite boulders along a transect of recessional moraines were sampled in the typical fashion of using a large piece of the boulder for analysis. Pyroxene minerals have been separated from these samples following the method of Bromley et al. (2014) using hydrofluoric acid. Exposure ages will be calculated from the He-3 concentrations in them. In the Mono Lake area of California, moraines were sampled from Bloody Canyon and McGee Creek sites. Instead of collecting a sample from an individual boulder, we collected approximately 25 granitic pebbles (1-3 cm) from 4-6 sites along the crest of the moraines following the method of Briner (2009). Each suite of pebbles was crushed together, and quartz minerals were separated from the agglomeration of pebbles. Cosmogenic Ne-21 will be measured from these samples to determine their exposure age. From these two field sites, we will use He-3 and Ne-21 to better understand the timing and extent of glaciation in these areas.

Age Estimation in Forensic Sciences

PubMed Central

Alkass, Kanar; Buchholz, Bruce A.; Ohtani, Susumu; Yamamoto, Toshiharu; Druid, Henrik; Spalding, Kirsty L.

2010-01-01

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. 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 study, we analyzed teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbon analysis is that aboveground testing of nuclear weapons during the cold war (1955–1963) caused an extreme increase in global levels of carbon-14 (14C), which has 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 10 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 1.0 ± 0.6 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. PMID:19965905

An improved determination of the lithium depletion boundary age of Blanco 1 and a first look on the effects of magnetic activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Juarez, Aaron J.; Stassun, Keivan G.; Cargile, Phillip A.

2014-11-10

The lithium depletion boundary (LDB) is a robust method for accurately determining the ages of young clusters, but most pre-main-sequence models used to derive LDB ages do not include the effects of magnetic activity on stellar properties. In light of this, we present results from our spectroscopic study of the very-low-mass members of the southern open cluster Blanco 1 using the Gemini-North Telescope, program IDs: GN-2009B-Q-53 and GN-2010B-Q-96. We obtained Gemini Multi-Object Spectrograph spectra at intermediate resolution for cluster candidate members with I ≈ 13-20 mag. From our sample of 43 spectra, we find 14 probable cluster members by consideringmore » proximity to the cluster sequence in an I/I – K {sub s} color-magnitude diagram, agreement with the cluster's systemic radial velocity, and magnetic activity as a youth indicator. We systematically analyze the Hα and Li features and update the LDB age of Blanco 1 to be 126{sub −14}{sup +13} Myr. Our new LDB age for Blanco 1 shows remarkable coevality with the benchmark Pleiades open cluster. Using available empirical activity corrections, we investigate the effects of magnetic activity on the LDB age of Blanco 1. Accounting for activity, we infer a corrected LDB age of 114{sub −10}{sup +9} Myr. This work demonstrates the importance of accounting for magnetic activity on LDB inferred stellar ages, suggesting the need to reinvestigate previous LDB age determinations.« less

Analysis of advanced glycation endproducts in selected food items by ultra-performance liquid chromatography tandem mass spectrometry: Presentation of a dietary AGE database.

PubMed

Scheijen, Jean L J M; Clevers, Egbert; Engelen, Lian; Dagnelie, Pieter C; Brouns, Fred; Stehouwer, Coen D A; Schalkwijk, Casper G

2016-01-01

The aim of this study was to validate an ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS) method for the determination of advanced glycation endproducts (AGEs) in food items and to analyze AGEs in a selection of food items commonly consumed in a Western diet. N(ε)-(carboxymethyl)lysine (CML), N(ε)-(1-carboxyethyl)lysine (CEL) and N(δ)-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were quantified in the protein fractions of 190 food items using UPLC-MS/MS. Intra- and inter-day accuracy and precision were 2-29%. The calibration curves showed perfect linearity in water and food matrices. We found the highest AGE levels in high-heat processed nut or grain products, and canned meats. Fruits, vegetables, butter and coffee had the lowest AGE content. The described method proved to be suitable for the quantification of three major AGEs in food items. The presented dietary AGE database opens the possibility to further quantify actual dietary exposure to AGEs and to explore its physiological impact on human health. Copyright © 2015 Elsevier Ltd. All rights reserved.

78 FR 4390 - Fisheries of the South Atlantic; Southeast Data, Assessment and Review (SEDAR); Public Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-22

...-step method for determining the status of fish stocks in the Southeast Region. SEDAR is a three step... information on life history characteristics, catch statistics, discard estimates, length and age composition...

Recovering Physical Activity Missing Data Measured by Accelerometers: A Comparison of Individual and Group-Centered Recovery Methods

ERIC Educational Resources Information Center

Zhuang, Jie; Chen, Peijie; Wang, Chao; Jin, Jing; Zhu, Zheng; Zhang, Wenjie

2013-01-01

Purpose: The purpose of this study was to determine which method, individual information-centered (IIC) or group information-centered (GIC), is more efficient in recovering missing physical activity (PA) data. Method: A total of 2,758 Chinese children and youth aged 9 to 17 years old (1,438 boys and 1,320 girls) wore ActiGraph GT3X/GT3X+…

Age-differentiated Risk Factors of Suicidal Ideation among Young and Middle-aged Korean Adults

PubMed Central

Jo, Ahra; Jeon, Minho; Oh, Heeyoung

2017-01-01

Objectives This study aimed to determine the prevalence of suicidal ideation among young and middle-aged adults, and explore the risk factors that affect suicidal ideation. Methods A descriptive study design was used for secondary data analysis. A total sample of 5,214 was drawn from two waves (2012–2013) of the 7th Korea Health Panel (KHP) survey. The KHP data were collected by a well-trained interviewer using the face-to-face method during home visits as well as self-report method. Descriptive statistics of frequency, percentage, chi-square test, and logistic regression analysis were performed using SPSS 22.0. Results The prevalence of suicidal ideation in young and middle-aged adults was 4.4% and 5.6%, respectively. For young adults, suicidal ideation risk was higher among those with low income or heavy drinking habits. In middle-aged adults, low income, poor perceived health status, negative perception of peer-compared health status, and negative social perspective were the major risk factors. Conclusion There is considerable risk of suicidal ideation in adulthood. Opportunities for increased income, avoidance of heavy drinking, and the construction of positive subjective health status and social perspective should be considered in suicide prevention interventions for Korean young and middle-aged adults. PMID:28781943

Capability of U-Pb dating of zircons from Quaternary tephra: Jemez Mountains, NM, and La Sal Mountains, UT, USA

NASA Astrophysics Data System (ADS)

Krautz, Jana; Hofmann, Mandy; Gärtner, Andreas; Linnemann, Ulf; Kleber, Arno

2018-01-01

Two Quaternary tephras derived from the Jemez Mountains, New Mexico - the Guaje and Tsankawi tephras - are difficult to distinguish due to their similar glass-shard chemical composition. Differences in bulk chemical composition are small as well. Here we examine the feasibility to assign an age to a distal tephra layer in the La Sal Mountains, Utah, by U-Pb dating of zircons and to correlate it with one of the two Jemez eruptions. We also dated original Jemez tephras for comparison. Even though the tephras are very young, we obtained reasonable age determinations using the youngest cluster of zircon grains overlapping in age at 2σ. Thereafter, the Guaje tephra is 1.513 ± 0.021 Myr old. The La Sal Mountains tephra is correlated with the Tsankawi tephra. Three samples yielded a common age range of 1.31-1.40 Myr. All ages are in slight disagreement with published age determinations obtained by 40Ar / 39Ar dating. These findings indicate that distal Jemez tephras can be distinguished by U-Pb dating. Furthermore, we encourage giving this method a try for age assignments even of Quaternary volcanic material.

Bone age detection via carpogram analysis using convolutional neural networks

NASA Astrophysics Data System (ADS)

Torres, Felipe; Bravo, María. Alejandra; Salinas, Emmanuel; Triana, Gustavo; Arbeláez, Pablo

2017-11-01

Bone age assessment is a critical factor for determining delayed development in children, which can be a sign of pathologies such as endocrine diseases, growth abnormalities, chromosomal, neurological and congenital disorders among others. In this paper we present BoneNet, a methodology to assess automatically the skeletal maturity state in pediatric patients based on Convolutional Neural Networks. We train and evaluate our algorithm on a database of X-Ray images provided by the hospital Fundacion Santa Fe de Bogot ´ a with around 1500 images of patients between the ages 1 to 18. ´ We compare two different architectures to classify the given data in order to explore the generality of our method. To accomplish this, we define multiple binary age assessment problems, dividing the data by bone age and differentiating the patients by their gender. Thus, exploring several parameters, we develop BoneNet. Our approach is holistic, efficient, and modular, since it is possible for the specialists to use all the networks combined to determine how is the skeletal maturity of a patient. BoneNet achieves over 90% accuracy for most of the critical age thresholds, when differentiating the images between over or under a given age.

Uneven-aged management of old-growth spruce-fir forests: Cutting methods and stand structure goals for the initial entry

Treesearch

Robert R. Alexander; Carleton B. Edminster

1977-01-01

Topics discussed include: (1) cutting methods, (2) stand structure goals, which involve choosing a residual stocking level, selecting a maximum tree size, and establishing a diameter distribution using the "q" technique, and (3) harvesting and removal of trees. Examples illustrate how to determine realistic stand structures for the initial entry for...

The Relationship between Balancing Reactions and Reaction Lifetimes: A Consideration of the Potassium-Argon Radiometric Method for Dating Minerals

ERIC Educational Resources Information Center

Howard, William A.

2005-01-01

A detailed examination of a commonly accepted practice in geology offers an example of how to stimulate critical thinking, teaches students how to read reactions, and challenges students to formulate better experiments for determining mineral ages more accurately. A demonstration of a Potassium-Argon radiometric method for dating minerals is…

Measures of Kindergarten Spelling and Their Relations to Later Spelling Performance

ERIC Educational Resources Information Center

Treiman, Rebecca; Kessler, Brett; Pollo, Tatiana Cury; Byrne, Brian; Olson, Richard K.

2016-01-01

Learning the orthographic forms of words is important for both spelling and reading. To determine whether some methods of scoring children's early spellings predict later spelling performance better than do other methods, we analyzed data from 374 U.S. and Australian children who took a 10-word spelling test at the end of kindergarten (M age =…

New 40Ar/39Ar age of the Bishop Tuff from multiple sites and sediment rate calibration for the Matuyama-Brunhes boundary

USGS Publications Warehouse

Sarna-Wojcicki, A. M.; Pringle, M.S.; Wijbrans, J.

2000-01-01

Precise dating of sanidine from proximal ash flow Bishop Tuff and air fall Bishop pumice and ash, California, can be used to derive an absolute age of the Matuyama Reversed-Brunhes Normal (M-B) paleomagnetic transition, identified stratigraphically close beneath the Bishop Tuff and ash at many sites in the western United States. An average age of 758.9 ?? 1.8 ka, standard error of the mean (SEM), was obtained for individual sanidine crystals or groups of several crystals, determined from ???70 individual analyses of sanidine separates from 11 sample groups obtained at five localities. The basal air fall pumice (757.7 ?? 1.8 ka) and overlying ash flow tuff (762.2 ?? 4.7 ka) from near the source yield essentially the same dates within errors of analysis, suggesting that the two units were emplaced close in time. A date on distal Bishop air fall ash bed at Friant, California, ???100 km to the west of the source area, is younger, 750.1 ?? 4.3 ka, but not significantly different within analytical error (??1 standard deviation). Previous dates of the Bishop Tuff, obtained by others using conventional K-Ar and the fission track method on zircons, ranged from ???650 ka to ???1.0 Ma. The most recent, generally accepted date by the K-Ar method on sanidine was 738 ?? 3 ka. We infer, as others before, that many K-Ar dates on sanidine feldspar are too young owing to incomplete degassing of radiogenic Ar during fusion in the K-Ar technique and that many older K-Ar dates are too old owing to detrital or xenocrystic contamination in the larger samples that are necessary for the technique. The new dates are similar to recent 40Ar/39Ar ages of the Bishop Tuff determined on individual samples by others but are derived from a larger proximal sample population and from multiple analysis of each sample. The results provide a definitive and precise age calibration of this widespread chronostratigraphic marker in the western United States and northeastern Pacific Ocean. We calculated the age of the M-B transition at five sites, assuming constant sedimentation rates, the age of the Bishop ash bed and one or more well-dated chronostratigraphic horizons above and below the Bishop Tuff ash bed and M-B transition, and stratigraphic separations between these datum levels. The age of the M-B transition is 774.2 ?? 2.8 ka, based on the average of eight such calculations, close to other recent determinations, and similar to that determined from the astronomically tuned polarity timescale. Our approach provides an alternative and surprisingly precise method for determining the age of the M-B and other chronostratigraphic levels. The above dates, calculated using U.S. Geological Survey values of 27.92 Ma for the Taylor Creek (TC) sanidine can be recalculated to other widely used values for these monitors. For example, using recently published values of 28.34 Ma (TC) and 523.1 Ma (McLure Mountain hornblende, MMhb-1), the resulting ages are ???774 ka for the Bishop Tuff and ash bed and ???789 ka for the M-B transition. Copyright 2000 by the American Geophysical Union.

Age assessment based on third molar mineralisation : An epidemiological-radiological study on a Central-European population.

PubMed

Hofmann, Elisabeth; Robold, Matthias; Proff, Peter; Kirschneck, Christian

2017-03-01

The method published in 1973 by Demirjian et al. to assess age based on the mineralisation stage of permanent teeth is standard practice in forensic and orthodontic diagnostics. From age 14 onwards, however, this method is only applicable to third molars. No current epidemiological data on third molar mineralisation are available for Caucasian Central-Europeans. Thus, a method for assessing age in this population based on third molar mineralisation is presented, taking into account possible topographic and gender-specific differences. The study included 486 Caucasian Central-European orthodontic patients (9-24 years) with unaffected dental development. In an anonymized, randomized, and blinded manner, one orthopantomogram of each patient at either start, mid or end of treatment was visually analysed regarding the mineralisation stage of the third molars according to the method by Demirjian et al. Corresponding topographic and gender-specific point scores were determined and added to form a dental maturity score. Prediction equations for age assessment were derived by linear regression analysis with chronological age and checked for reliability within the study population. Mineralisation of the lower third molars was slower than mineralisation of the upper third molars, whereas no jaw-side-specific differences were detected. Gender-specific differences were relatively small, but girls reached mineralisation stage C earlier than boys, whereas boys showed an accelerated mineralisation between the ages of 15 and 16. The global equation generated by regression analysis (age = -1.103 + 0.268 × dental maturity score 18 + 28 + 38 + 48) is sufficiently accurate and reliable for clinical use. Age assessment only based on either maxilla or mandible also shows good prognostic reliability.

Comparing Four Age Model Techniques using Nine Sediment Cores from the Iberian Margin

NASA Astrophysics Data System (ADS)

Lisiecki, L. E.; Jones, A. M.; Lawrence, C.

2017-12-01

Interpretations of paleoclimate records from ocean sediment cores rely on age models, which provide estimates of age as a function of core depth. Here we compare four methods used to generate age models for sediment cores for the past 140 kyr. The first method is based on radiocarbon dating using the Bayesian statistical software, Bacon [Blaauw and Christen, 2011]. The second method aligns benthic δ18O to a target core using the probabilistic alignment algorithm, HMM-Match, which also generates age uncertainty estimates [Lin et al., 2014]. The third and fourth methods are planktonic δ18O and sea surface temperature (SST) alignments to the same target core, using the alignment algorithm Match [Lisiecki and Lisiecki, 2002]. Unlike HMM-Match, Match requires parameter tuning and does not produce uncertainty estimates. The results of these four age model techniques are compared for nine high-resolution cores from the Iberian margin. The root mean square error between the individual age model results and each core's average estimated age is 1.4 kyr. Additionally, HMM-Match and Bacon age estimates agree to within uncertainty and have similar 95% confidence widths of 1-2 kyr for the highest resolution records. In one core, the planktonic and SST alignments did not fall within the 95% confidence intervals from HMM-Match. For this core, the surface proxy alignments likely produce more reliable results due to millennial-scale SST variability and the presence of several gaps in the benthic δ18O data. Similar studies of other oceanographic regions are needed to determine the spatial extents over which these climate proxies may be stratigraphically correlated.

[Pitfalls in the prescription of reading glasses].

PubMed

Krause, H-K

2011-04-01

People in the second half of their lives often require reading glasses. A basic requirement for determining suitable reading glasses is measurement of the patient's accommodation, which describes the change in the eye's optical power caused by the attempt to clearly focus on an object at a certain distance. The maximum accommodation performance of a person already begins to decline from the age of 40 onwards. When it becomes increasingly difficult to adjust to the typical reading distance of 40 cm, one speaks of presbyopia: age-related farsightedness. This contribution describes two appropriate methods for determining the strength of reading glasses: determination of the maximum accommodation performance by measuring the near point distance and determination of the maximum accommodation effort by measuring the relative positive and negative accommodation. Optimal reading glasses enable the patient to focus sharply on something from the working distance that is closer but also on something that is further away.

A comparison of field methods to assess body composition in a diverse group of sedentary women.

PubMed

D'Alonzo, Karen T; Aluf, Ana; Vincent, Linda; Cooper, Kristin

2009-01-01

Accurate assessment of body composition is essential in the evaluation of obesity. While laboratory methods are commonly used to assess fat mass, field measures (e.g., skinfold thickness [SKF] and bioelectrical impedance [BIA]) may be more practical for screening large numbers of individuals in intervention studies. In this study, a correlational design was used among 46 racially and ethnically diverse, sedentary women (mean age = 25.73 years) to (a) compare the percentage of body fat as determined by SKF and the upper body BIA and (b) examine the effects of body mass index (BMI), racial/ethnic background, age, and stage of the menstrual cycle on differences in the estimated percentage of body fat obtained using the SKF and BIA. Overall, a significant correlation between SKF and BIA (r = .98, p < .001) was found, with similar findings among Black, Hispanic and White non-Hispanic women. The mean differences between BIA and SKF were not significantly correlated with BMI, age, race/ethnicity or stage of the menstrual cycle. Data from this study suggest that BIA showed similar body fat prediction values compared with SKF and may be a viable alternative to SKF among diverse groups of healthy women. Additional testing and comparison of these field methods with the laboratory methods of hydro-densitometry or dual energy X-ray absorptiometry is recommended to further determine whether BIA devices can be routinely recommended as an alternative to the SKF.

A Video Method to Study Drosophila Sleep

PubMed Central

Zimmerman, John E.; Raizen, David M.; Maycock, Matthew H.; Maislin, Greg; Pack, Allan I.

2008-01-01

Study Objectives: To use video to determine the accuracy of the infrared beam-splitting method for measuring sleep in Drosophila and to determine the effect of time of day, sex, genotype, and age on sleep measurements. Design: A digital image analysis method based on frame subtraction principle was developed to distinguish a quiescent from a moving fly. Data obtained using this method were compared with data obtained using the Drosophila Activity Monitoring System (DAMS). The location of the fly was identified based on its centroid location in the subtracted images. Measurements and Results: The error associated with the identification of total sleep using DAMS ranged from 7% to 95% and depended on genotype, sex, age, and time of day. The degree of the total sleep error was dependent on genotype during the daytime (P < 0.001) and was dependent on age during both the daytime and the nighttime (P < 0.001 for both). The DAMS method overestimated sleep bout duration during both the day and night, and the degree of these errors was genotype dependent (P < 0.001). Brief movements that occur during sleep bouts can be accurately identified using video. Both video and DAMS detected a homeostatic response to sleep deprivation. Conclusions: Video digital analysis is more accurate than DAMS in fly sleep measurements. In particular, conclusions drawn from DAMS measurements regarding daytime sleep and sleep architecture should be made with caution. Video analysis also permits the assessment of fly position and brief movements during sleep. Citation: Zimmerman JE; Raizen DM; Maycock MH; Maislin G; Pack AI. A video method to study drosophila sleep. SLEEP 2008;31(11):1587–1598. PMID:19014079

Socioeconomic factors associated with contraceptive use and method choice in urban slums of Bangladesh.

PubMed

Kamal, S M Mostafa

2015-03-01

This article explores the socioeconomic factors affecting contraceptive use and method choice among women of urban slums using the nationally representative 2006 Bangladesh Urban Health Survey. Both bivariate and multivariate statistical analyses were applied to examine the relationship between a set of sociodemographic factors and the dependent variables. Overall, the contraceptive prevalence rate was 58.1%, of which 53.2% were modern methods. Women's age, access to TV, number of unions, nongovernmental organization membership, working status of women, number of living children, child mortality, and wealth index were important determinants of contraceptive use and method preference. Sex composition of surviving children and women's education were the most important determinants of contraceptive use and method choice. Programs should be strengthened to provide nonclinical modern methods free of cost among the slum dwellers. Doorstep delivery services of modern contraceptive methods may raise the contraceptive prevalence rate among the slum dwellers in Bangladesh. © 2011 APJPH.

Results of Radiocarbon Dating of Holocene Deposits from the Sea of Azov

NASA Astrophysics Data System (ADS)

Matishov, G. G.; Kovaleva, G. V.; Arslanov, Kh. A.; Dyuzhova, K. V.; Polshin, V. V.; Zolotareva, A. E.

2018-04-01

New data on the absolute age of Quaternary bottom deposits from the Sea of Azov based on the results of radiocarbon analysis (14C) are presented. Overall, 67 radiocarbon dating of bottom deposits of New and Ancient Azov Ages were obtained. The thickness of sediments of the New Azov Age and their distribution over different areas of the Sea of Azov was determined during the study; the results obtained were compared with the reference data available. An integrated approach to the study of deposits, based on the combination of the biostratigraphy methods and the results of absolute age dating, was applied.

A simple radiocarbon dating method for determining the age and growth rate of deep-sea sponges

NASA Astrophysics Data System (ADS)

Fallon, S. J.; James, K.; Norman, R.; Kelly, M.; Ellwood, M. J.

2010-04-01

The ability to reliably age siliceous sponges is explored using radiocarbon dating of several hexactinellid sponge specimens including Rossella racovitzaeracovitzae Topsent, 1901 ( C. Hexactinellida: O. Lyssacinosida: F. Rossellidae), collected from the Ross Sea, Antarctica. The optimal pretreatment was found to consist of both sequential acid digestion and pre-roasting at temperatures >400 °C. Subsequent combustion at 900 °C liberated the proteinaceous material within the spicule matrix and once the reservoir age of the surrounding water was accounted for, a linear extension rate was calculated to be around 2.9 mm yr -1, aging the sponge at ˜440 years old.

Variations in the form of the hypoglossal canal in ancient Anatolian populations: comparison of two recording methods.

PubMed

Eroğlu, S

2010-02-01

In this study, the frequency of bridging of the hypoglossal canal was investigated on 324 skulls belonging to 10 ancient Anatolian populations recovered from various archaeological sites and dated from Early Bronze Age to the first quarter of the 20th century. The change in the frequency of bridging trait in the hypoglossal canal that has already been recorded according to both the traditional method (absent or present) and the graded method (0-5) was analysed here in relationship to age, sex, skull side and population. The results revealed no significant relation between the bridging of hypoglossal canal and age or sex. Both recording methods showed that the studied samples of ancient Anatolian populations exhibited a homogenous structure and they were found to differ considerably from other populations which inhabited lands other than Anatolia. This indicates that these two recording methods produce similar results in comparing populations. The differences between the sides were found to be significant with the detailed recording method as opposed to the dichotomous method. This asymmetry emerging with the detailed recording method is considered to be important in determining the effect of environmental factors upon the trait. Copyright (c) 2010 Elsevier GmbH. All rights reserved.

Socio-economic and cultural differentials in contraceptive usage among Ghanaian women.

PubMed

Oheneba-sakyi, Y

1990-01-01

Data from the Ghana Fertility Survey of 2001 married women in 1979-1980 were subjected to logistic regression to determine the factors influencing contraceptive use. In this Ghanaian sample only 22 women and no men were sterilized, 11% used an efficient contraceptive method and 8% were using an inefficient method. The most prevalent methods were abstinence by 6% and pill by 5%. The variables analyzed were birth cohort, age at 1st marriage, education, occupation, religion, ethnicity, rural/urban residence, northern/southern residence and number of children desired number of living children. All these factors were dichotomized, e.g., cohort: born before or after 1950. Factors positively significant for contraceptive use were younger women (20% more likely), married at age 20 or older (82% more), education (150% for any method, 67% for an efficient method), professional occupations, protestants, urban residence, southern residence, desire fewer children. Factors negatively associated with contraception were agricultural work (50% as likely), non-Christian religion, both traditional and Moslems (75%), desiring more children and living in the north. Unexpectedly, living in the northern undeveloped region was strongly linked with use of an efficient contraceptive. A factor without significant effect was ethnicity, Akan or non-Akan. These results were discussed with a general review of the literature on determinants of contraceptive use.

[Construction of a psychological aging scale for healthy people].

PubMed

Lin, Fei; Long, Yao; Zeng, Ni; Wu, Lei; Huang, Helang

2017-04-28

To construct a psychological aging scale, and to provide a tool and indexes for scientific evaluation on aging.
 Methods: The age-related psychological items were collected through literature screening and expert interview. The importance, feasibilityand the degree of authority for the psychological index system were graded by two rounds of Delphi method. Using analytic hierarchy process, the weight of dimensions and items were determined. The analysis for internal consistency reliability, correlation and exploratory factor was performed to evaluate the reliability and validity of the scales.
 Results: By two rounds of Delphi method, 17 experts offered the results as follows: the coefficient of expert authorities was 0.88±0.06, the coordination coefficients for the importance and feasibility in second round were 0.456 (P<0.01) and 0.666 (P<0.01), respectively. The consistency was good. The psychological aging scale for healthy people included 4 dimensions as follows: cognitive function, emotion, personality and motivation. The weight coefficients for the 4 dimensions were 0.338, 0.250, 0.166 and 0.258, respectively. The Cronbach's α coefficient for the scale was 0.822, the reliability was 0.817, the content validity index (CVI) was 0.847, and the cumulative contribution rate for the 5 factors was51.42%.
 Conclusion: The psychological aging scale is satisfied, which can provide reference for the evaluation for aging. The indicators were representative and well-recognized.

Estimation of the brain stem volume by stereological method on magnetic resonance imaging.

PubMed

Erbagci, Hulya; Keser, Munevver; Kervancioglu, Selim; Kizilkan, Nese

2012-11-01

Neuron loss that occurs in some neurodegenerative diseases can lead to volume alterations by causing atrophy in the brain stem. The aim of this study was to determine the brain stem volume and the volume ratio of the brain stem to total brain volume related to gender and age using new Stereo Investigator system in normal subjects. For this purpose, MR images of 72 individuals who have no pathologic condition were evaluated. The total brain volumes of female and male were calculated as 966.81 ± 77.44 and 1,074.06 ± 111.75 cm3, respectively. Brain stem volumes of female and male were determined as 18.99 ± 2.36 and 22.05 ± 4.01 cm3, respectively. The ratios of brain stem volume to total brain volume were 1.96 ± 0.17 in female and 2.05 ± 0.29 in male. The total brain and brain stem volumes were observed smaller in female and it is statistically significant. Among the individuals whose ages are between 20 and 40, total brain and brain stem volume measurements with aging were not statistically significant. As a result, we believe that the measurement of brain stem volume with an objective and efficient calculation method will contribute to the early diagnosis of neurodegenerative diseases, as well as to determine the rate of disease progression, and the outcomes of treatment.

Prevalence and determinant factors of exclusive breastfeeding practices among mothers in Enderta woreda, Tigray, North Ethiopia: a cross-sectional study.

PubMed

Teka, Bahre; Assefa, Huruy; Haileslassie, Kiday

2015-01-01

In Ethiopia national breastfeeding practice is poor because of traditional and cultural beliefs, low educational levels, heavy workload of mothers, poor sanitary conditions, type of assistance at delivery, duration of stay at home, ethnicity, poor maternal knowledge, age, parity, antenatal service utilization and place of delivery. This study is aimed to assess the prevalence and determinants of exclusive breastfeeding practice in mothers in Enderta woreda (district), Ethiopia. A community based cross-sectional study with multistage sampling method was used to select 541 mothers with children less than 24 months of age in Enderta woreda. Data was collected by administered structured questionnaire. Bivariate and Multivariable logistic regression was used to check the associations and controlling confounding variables. A total of 530 mothers were included with a response rate 98%. The mean (± SD) age of the mothers was 26.9 (± 5.98) years. Majority of the mothers (70.2%) were practiced exclusive breastfeeding. Age of the mother (AOR 0.12; 95% CI: 0.02, 0.97), age of the child (AOR 0.52 95% CI: 0.27, 0.99) and postnatal care (AOR; 2.68; 95% CI: 1.44, 4.98) were found statistically significant with exclusive breastfeeding. The prevalence rate of exclusive breastfeeding was high in Enderta woreda. The age of the mother, age of the child and receiving postnatal care were the determinant factors for exclusive breastfeeding in the study area.

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

NASA Astrophysics Data System (ADS)

Scharer, Katherine M.; Biasi, Glenn P.; Weldon, Ray J., II

2011-12-01

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

Anisotropic bioelectrical impedance determination of subcutaneous fat thickness

NASA Astrophysics Data System (ADS)

Hernández-Becerra, P. A. I.; Delgadillo-Holtfort, I.; Balleza-Ordaz, M.; Huerta-Franco, M. R.; Vargas-Luna, M.

2014-11-01

Preliminary results have shown that bioelectrical impedance measurements performed on different parts of the human body strongly depend upon the subcutaneous fat of the considered region. In this work, a method for the determination of subcutaneous fat thickness is explored. Within this method the measurement of the bioelectrical impedance response of the fat-muscle system, both along the direction defined by the muscle fibers and along the corresponding perpendicular direction, are performed. Measurements have been carried out on human female and male subjects of ages around 25 years old at the region of the biceps. Correlation has been performed with skinfold caliper measurements.

[Correlation of dental age and anthropometric parametres of the overall growth and development in children].

PubMed

Triković-Janjić, Olivera; Apostolović, Mirjana; Janosević, Mirjana; Filipović, Gordana

2008-02-01

Anthropometric methods of measuring the whole body and body parts are the most commonly applied methods of analysing the growth and development of children. Anthropometric measures are interconnected, so that with growth and development the change of one of the parameters causes the change of the other. The aim of the paper was to analyse whether dental development follows the overall growth and development and what the ratio of this interdependence is. The research involved a sample of 134 participants, aged between 6 and 8 years. Dental age was determined as the average of the sum of existing permanent teeth from the participants aged 6, 7 and 8. With the aim of analysing physical growth and development, commonly accepted anthropometric indexes were applied: height, weight, circumference of the head, the chest cavity at its widest point, the upper arm, the abdomen, the thigh and thickness of the epidermis. The dimensions were measured according to the methodology of the International Biological Programme. The influence of the pertinent variables' related size on the analysed variable was deter mined by the statistical method of multivariable regression. The middle values of all the anthropometric parametres, except for the thickness of the epidermis, were slightly bigger with male participants, and the circumference of the chest cavity was statistically considerably bigger (p < 0.05). The results of anthropometric measurement showed in general a distinct homogeneity not only of the sample group but also within gender, in relation to all the dimensions, excyt for the thickness of the epidermis. The average of the dental age of the participants was 10.36, (10.42 and 10.31 for females and males respectively). Considerable correlation (R = 0.59) with high statistical significance (p < 0.001) was determined between dental age and the set of anthropometric parameters of general growth and development. There is a considerable positive correlation (R = 0.59) between dental age and anthropometric parameters of general growth and development, which confirms that dental development follows the overall growth and development of children, aged between 6 and 8 years.

Coupling of Uranium and Thorium Series Isotope Systematics for Age Determination of Late Pleistocene Zircons using LA-ICP-MS

NASA Astrophysics Data System (ADS)

Sakata, S.; Hirakawa, S.; Iwano, H.; Danhara, T.; Hirata, T.

2014-12-01

Zircon U-Th-Pb dating method is one of the most important tools for estimating the duration of magmatism by means of coupling of uranium, actinium and thorium decay series. Using U-Pb dating method, its reliability is principally guaranteed by the concordance between 238U-206Pb and 235U-207Pb ages. In case of dating Quaternary zircons, however, the initial disequilibrium effect on 230Th and 231Pa should be considered. On the other hands, 232Th-208Pb dating method can be a simple but powerful approach for investigating the age of crystallization because of negligible influence from initial disequilibrium effect. We have developed a new correction model for accurate U-Pb dating of the young zircon samples by taking into consideration of initial disequilibrium and a U-Pb vs Th-Pb concordia diagram for reliable age calibration was successfully established. Hence, the U-Th-Pb dating method can be applied to various zircons ranging from Hadean (4,600 Ma) to Quaternary (~50 ka) ages, and this suggests that further detailed information concerning the thermal history of the geological sequences can be made by the coupling of U-Th-Pb, fission track and Ar-Ar ages. In this presentation, we will show an example of U-Th-Pb dating for zircon samples from Sambe Volcano (3 to 100 ka), southwest Japan and the present dating technique using LA-ICP-MS.

Evaluation of Retinal Function and Morphology of the Pink-Eyed Royal College of Surgeons (RCS) Rat: A Comparative Study of in Vivo and in Vitro Methods.

PubMed

Rösch, Sarah; Aretzweiler, Christoph; Müller, Frank; Walter, Peter

2017-02-01

To characterize the course of retinal degeneration in the pink-eyed RCS rat in vivo and in vitro. Retinal function of RCS rats at the age of 2 to 100 weeks was determined in vivo using full-field electroretinography (ERG). Retinal morphology was evaluated in vivo using spectral domain Optical Coherence Tomography (sd-OCT) and Fluorescence angiography (FA) as well as postmortem using immunohistochemistry (IH). As a control, retinal function and morphology of non-dystrophic Wistar rats were analyzed. RCS rats showed an extinction of the ERG beginning with the age of 4 weeks. In the OCT, the outer part of the retina (OPR) could be clearly distinguished from the inner part of the retina (IPR) until the age of 8 weeks. However, at this age, it was impossible to determine from OCT images whether the OPR was formed by the outer nuclear layer (ONL) or by cellular debris built in the course of retinal degeneration. In contrast, immunohistochemistry always enabled to differentiate between ONL and debris (RCS 4 weeks of age: OPR mainly formed by ONL; RCS 8 weeks of age: OPR consisted mainly of cell debris, only 1-2 cell rows of photoreceptor somata were left). In general, data obtained in vivo were confirmed by data obtained post mortem. Apart from the problem to differentiate between debris and ONL at the age of 8 weeks in the RCS rat, ERG and OCT are useful methods to evaluate retinal function and structure in vivo and to complement immunohistochemical analysis of the degeneration process.

Potassium Isotopic Compositions of NIST Potassium Standards and 40Ar/39Ar Mineral Standards

NASA Technical Reports Server (NTRS)

Morgan, Leah; Tappa, Mike; Ellam, Rob; Mark, Darren; Higgins, John; Simon, Justin I.

2013-01-01

Knowledge of the isotopic ratios of standards, spikes, and reference materials is fundamental to the accuracy of many geochronological methods. For example, the 238U/235U ratio relevant to U-Pb geochronology was recently re-determined [1] and shown to differ significantly from the previously accepted value employed during age determinations. These underlying values are fundamental to accurate age calculations in many isotopic systems, and uncertainty in these values can represent a significant (and often unrecognized) portion of the uncertainty budget for determined ages. The potassium isotopic composition of mineral standards, or neutron flux monitors, is a critical, but often overlooked component in the calculation of K-Ar and 40Ar/39Ar ages. It is currently assumed that all terrestrial materials have abundances indistinguishable from that of NIST SRM 985 [2]; this is apparently a reasonable assumption at the 0.25per mille level (1s) [3]. The 40Ar/39Ar method further relies on the assumption that standards and samples (including primary and secondary standards) have indistinguishable 40K/39K values. We will present data establishing the potassium isotopic compositions of NIST isotopic K SRM 985, elemental K SRM 999b, and 40Ar/39Ar biotite mineral standard GA1550 (sample MD-2). Stable isotopic compositions (41K/39K) were measured by the peak shoulder method with high resolution MC-ICP-MS (Thermo Scientific NEPTUNE Plus), using the accepted value of NIST isotopic SRM 985 [2] for fractionation [4] corrections [5]. 40K abundances were measured by TIMS (Thermo Scientific TRITON), using 41K/39K values from ICP-MS measurements (or, for SRM 985, values from [2]) for internal fractionation corrections. Collectively these data represent an important step towards a metrologically traceable calibration of 40K concentrations in primary 40Ar/39Ar mineral standards and improve uncertainties by ca. an order of magnitude in the potassium isotopic compositions of standards.

Prevalence and predictors of human papillomavirus infection in women in Ontario, Canada

PubMed Central

Sellors, John W.; Mahony, James B.; Kaczorowski, Janusz; Lytwyn, Alice; Bangura, Helen; Chong, Sylvia; Lorincz, Attila; Dalby, Dawn M.; Janjusevic, Vladan; Keller, Jana L

2000-01-01

Background Human papillomavirus (HPV) is thought to be the primary cause of cervical intraepithelial neoplasia and cervical cancer. We determined the age-specific prevalence of HPV infection and its risk factors in Ontario women. Methods We obtained 2 cervical specimens from randomly selected women (in 5-year age categories, from 15 to 49 years) who were being seen in 32 family practices for cytologic screening. The specimens were tested for carcinogenic HPV by the hybrid capture II assay (Digene Corp., Silver Spring, Md.) and by polymerase chain reaction (PCR) and genotyping. Results Of 1004 women eligible to participate, samples were obtained from 955 (95.1%). The prevalence of HPV (as determined by the hybrid capture II method) was highest, at 24.0% (95% confidence interval [CI] 16.5% to 31.5%), among women 20 to 24 years of age and was progressively lower in older age groups, reaching 3.4% (95% CI 0.1% to 6.7%) in women 45 to 49 years old. The prevalence of HPV (any type) as determined by PCR showed a similar pattern but was significantly higher (p = 0.01) among women 45 to 49 years old than among those 40 to 44 years old (13.0% [95% CI 6.4% to 19.6%] v. 3.3% [95% CI 0.1% to 6.5%]). Risk factors for positivity with the hybrid capture II method were never-married status, divorced or separated status, more than 3 lifetime partners, more than 1 partner in the preceding year, cigarette smoking and current use of oral contraceptives. The presence of squamous intraepithelial lesions on cytologic examination was strongly associated with positivity with the hybrid capture II assay (odds ratio 96.0, 95% CI 22.3 to 413.4; p < 0.01). Interpretation The highest prevalence of HPV was 24.0%, in women 20 to 24 years old. Risk factors supported a sexual mode of transmission, and there was a strong association between HPV and abnormal cervical cytologic result PMID:11006760

Interaction between PNPLA3 I148M Variant and Age at Infection in Determining Fibrosis Progression in Chronic Hepatitis C

PubMed Central

Aghemo, Alessio; Cheroni, Cristina; D'Ambrosio, Roberta; Pedrazzini, Michele; Marabita, Francesco; Donnici, Lorena; Maggioni, Marco; Fargion, Silvia; Colombo, Massimo; De Francesco, Raffaele; Valenti, Luca

2014-01-01

Background and Aims The PNPLA3 I148M sequence variant favors hepatic lipid accumulation and confers susceptibility to hepatic fibrosis and hepatocellular carcinoma. The aim of this study was to estimate the effect size of homozygosity for the PNPLA3 I148M variant (148M/M) on the fibrosis progression rate (FPR) and the interaction with age at infection in chronic hepatitis C (CHC). Methods FPR was estimated in a prospective cohort of 247 CHC patients without alcohol intake and diabetes, with careful estimation of age at infection and determination of fibrosis stage by Ishak score. Results Older age at infection was the strongest determinant of FPR (p<0.0001). PNPLA3 148M/M was associated with faster FPR in individuals infected at older age (above the median, 21 years; −0.64±0.2, n = 8 vs. −0.95±0.3, n = 166 log10 FPR respectively; p = 0.001; confirmed for lower age thresholds, p<0.05), but not in those infected at younger age (p = ns). The negative impact of PNPLA3 148M/M on fibrosis progression was more marked in subjects at risk of altered hepatic lipid metabolism (those with grade 2–3 steatosis, genotype 3, and overweight; p<0.05). At multivariate analysis, PNPLA3 148M/M was associated with FPR (incremental effect 0.08±0.03 log10 fibrosis unit per year; p = 0.022), independently of several confounders, and there was a significant interaction between 148M/M and older age at infection (p = 0.025). The association between 148M/M and FPR remained significant even after adjustment for steatosis severity (p = 0.032). Conclusions We observed an interaction between homozygosity for the PNPLA3 I148M variant and age at infection in determining fibrosis progression in CHC patients. PMID:25171251

[Use of Plusoptix as a screening method for refractive ambliopia].

PubMed

Bogdănici, T; Tone, Silvia; Miron, Mihaela; Boboc, Mihaela; Bogdănici, Camelia

2012-01-01

Highlighting the differences in the objective refraction using the Plusoptix AO9 comparing them with the refraction performed with TOPCON KR-8900 autorefractor. Prospective study for 3 months held in the Ophthalmology Clinic in Iasi, Hospital Sf. Spiridon on a total of 39 children (21 girls and 18 boys) with mean age of 10.61 +/- 5.67 years. Clinical parameters: sex, age, objective refraction obtained with Plusoptix and with autorefractor corrected visual acuity (with different methods depending on each patient age), ortoptic examination (strabic deviation, binocular vision), the presence of symetry/asymetry while measuring with Plusoptix. The results were statistically processed by F-TEST calculating the correlation coefficient, standard deviation, significance level (using the spherical equivalent of the obtained values). Age limits of the studied cases ranged between 2-23 years. Visual acuity of children who had cooperate was between 0.2-1 with correction, achieving best values on right eye than left eye. 8 cases (20.51%) had large differences between measurements made with Plusoptix and autorefractor, half of that (4 cases) had strabismus. Three of these cases were with small hypermetropia and one with small myopia (Plusoptix shows a lower value). In 2 cases occurred higher differences (about 2-2,5D) between the 2 measurements, in patients with average hypermetropia. Plusoptix refraction was not possible at high hypermetropia or high myopia. This type of determining objective refraction using Plusoptix is a useful method of screening for discovery of refractive errors that can cause refractive amblyopia in young children and in those cases with a difficult collaboration. Because there are differences betweeti this 2 methods, for children with refractive errors are recommended further exploration to determine the appropriate optical correction. Plusoptix is a limited method because it cannot detect the exact values in those cases with high hypermetropia or high myopia.

Global and regional cause-of-death patterns in 1990.

PubMed Central

Murray, C. J.; Lopez, A. D.

1994-01-01

Demographic estimation techniques suggest that worldwide about 50 million deaths occur each year, of which about 39 million are in the developing countries. In countries with adequate registration of vital statistics, the age at death and the cause can be reliably determined. Only about 30-35% of all deaths are captured by vital registration (excluding sample registration schemes); for the remainder, cause-of-death estimation procedures are required. Indirect methods which model the cause-of-death structure as a function of the level of mortality can provide reasonable estimates for broad cause-of-death groups. Such methods are generally unreliable for more specific causes. In this case, estimates can be constructed from community-level mortality surveillance systems or from epidemiological evidence on specific diseases. Some check on the plausibility of the estimates is possible in view of the hierarchical structure of cause-of-death lists and the well-known age-specific patterns of diseases and injuries. The results of applying these methods to estimate the cause of death for over 120 diseases or injuries, by age, sex and region, are described. The estimates have been derived in order to calculate the years of life lost due to premature death, one of the two components of overall disability-adjusted life years (DALYs) calculated for the 1993 World development report. Previous attempts at cause-of-death estimation have been limited to a few diseases only, with little age-specific detail. The estimates reported in detail here should serve as a useful reference for further public health research to support the determination of health sector priorities. PMID:8062402

Harris lines of the tibia across centuries: a comparison of two populations, medieval and contemporary in Central Europe.

PubMed

Ameen, S; Staub, L; Ulrich, S; Vock, P; Ballmer, F; Anderson, S E

2005-05-01

To determine the incidence of Harris lines in two medieval populations which inhabited the Canton of Berne, in Central Switzerland, and to compare the results with those of a contemporary population living in the same geographical area. A simplified method is described for measuring the age of the individual at the time of formation of Harris lines, with possible future applications. Radiographs of 112 well-preserved tibiae of skeletons of two medieval populations from the eighth to fifteenth centuries were reviewed for the incidence of Harris lines. The results were compared with those of 138 current patients living in the same geographic location in Central Switzerland. Age and gender of the medieval individual were determined using known anthropological methods. Age of bone at the time of formation of Harris lines was estimated according to the method of Maat. Harris lines were found in 88 of 112 (80%) of the examined medieval skeletons and in 28 of 138 (20%) of the living individuals. Higher incidences of Harris lines were found at the age of 2 years and at ages between 8 and 12 years in both populations. No gender difference was found regarding the incidence of Harris lines. In both populations the occurrence of Harris lines was associated with certain diseases such as degenerative bone disease, trauma, osteoporosis, rheumatoid arthritis, peripheral vascular diseases, rickets and bony deformities. A high incidence of Harris lines was found in the medieval population, perhaps reflecting difficult living and hygienic conditions, but also the poor care and neglect of the children population. Measuring the age of the individual at the time of formation of Harris lines is simple and may have future clinical applications in the paediatric population for medico-legal purposes. The application of Harris lines as a marker in follow-up of osteoporosis may need further evaluation.

Forecasting the timing of peak mandibular growth in males by using skeletal age.

PubMed

Hunter, W Stuart; Baumrind, Sheldon; Popovich, Frank; Jorgensen, Gertrud

2007-03-01

It is generally believed that the orthodontic treatment of a patient with a Class II malocclusion and a small mandible is enhanced by good growth at puberty, so that the timing of peak mandibular growth at puberty becomes of interest. To test the belief that skeletal age, whether early, average, or late, can be used to predict the timing of maximum growth of the mandible, whether early, average, or late, the predictive relationship between skeletal age and peak mandibular growth velocity (PMdV) at puberty was evaluated in 94 boys by using their longitudinal records from 4 to 18 years of age. Skeletal age was determined for each subject at ages 9 through 14 by using the method of Greulich and Pyle. At age 9, the Greulich and Pyle measurements predicted that 30 of the 94 subjects would have delayed PMdV equal to or exceeding 1 SD (of the mean age for PMdV), and 10 would have advanced PMdV equal to or exceeding 1 SD. When the actual age of PMdV was determined retrospectively from plots of annual mandibular growth increments, it was found that only 4 of the 30 in the delayed group had actually experienced delays in PMdV, and only 2 of the 10 in the advanced group had experienced accelerated PMdV. Skeletal age is not a reliable predictor of the timing of PMdV.

Age-Based Differences in the Genetic Determinants of Glycemic Control: A Case of FOXO3 Variations

PubMed Central

Sun, Liang; Hu, Caiyou; Qian, Yu; Zheng, Chenguang; Liang, Qinghua; Lv, Zeping; Huang, Zezhi; Qi, Keyan; Huang, Jin; Zhou, Qin; Yang, Ze

2015-01-01

Background Glucose homeostasis is a trait of healthy ageing and is crucial to the elderly, but less consideration has been given to the age composition in most studies involving genetics and hyperglycemia. Methods Seven variants in FOXO3 were genotyped in three cohorts (n = 2037; LLI, MI_S and MI_N; mean age: 92.5±3.6, 45.9±8.2 and 46.8±10.3, respectively) to compare the contribution of FOXO3 to fasting hyperglycemia (FH) between long-lived individuals (LLI, aged over 90 years) and middle-aged subjects (aged from 35–65 years). Results A different genetic predisposition of FOXO3 alleles to FH was observed between LLI and both of two middle-aged cohorts. In the LLI cohort, the longevity beneficial alleles of three variants with the haplotype “AGGC” in block 1 were significantly protective to FH, fasting glucose, hemoglobin A1C and HOMA-IR. Notably, combining multifactor dimensionality reduction and logistic regression, we identified a significant 3-factor interaction model (rs2802288, rs2802292 and moderate physical activity) associated with lower FH risk. However, not all of the findings were replicated in the two middle-aged cohorts. Conclusion Our data provides a novel insight into the inconsistent genetic determinants between middle-aged and LLI subjects. FOXO3 might act as a shared genetic predisposition to hyperglycemia and lifespan. PMID:25993007

THE EQUIVALENCE OF AGE IN ANIMALS

PubMed Central

Brody, Samuel; Ragsdale, Arthur C.

1922-01-01

1. A method of plotting growth curves is presented which is considered more useful than the usual method in bringing out a number of important phenomena such as the equivalence of age in different animals, difference in the shape and duration of corresponding growth cycles in different animals, and also in determinating the age of maxima without resorting to complicated mathematical computations. 2. It is suggested that after the third cycle is past the conceptional age of the maximum of the third cycle may be taken as the age of reference for estimating the equivalent physiological ages in different animals. Before the age of the third cycle, the maxima of the second and first cycles are most conveniently used as points of reference. 3. It is shown that the product of the conceptional age of the maximum of the third cycle by 13, gives a value which is, with the possible exception of man, very near to the normal duration of life of animals under the most favorable conditions of life. In other words, the equivalent physiological ages in different animals bear an approximately constant linear relation to the duration of their growth periods. 4. Attention is called to certain differences in the shape and duration of the corresponding growth cycles in different animals and of the effect of sex on these cycles. PMID:19871989

Technology use by rural and urban oldest old

PubMed Central

Calvert, James F.; Kaye, Jeffrey; Leahy, Marjorie; Hexem, Kari; Carlson, Nichole

2010-01-01

Objectives Technologies designed to optimally maintain older people as they age in their desired places of residence are proliferating. An important step in designing and deploying such technologies is to determine the current use and familiarity with technology in general among older people. The goal of this study was to determine the extent that community-dwelling elderly at highest risk of losing independence, the oldest old, use common electronic devices found in residential urban or rural settings. Methods We surveyed 306 nondemented elderly age 85 or over; 144 were part of a rural aging study, the Klamath Exceptional Aging Project, and 181 were from an urban aging cohort in Portland. Results The most frequently used devices were televisions, microwave ovens, and answering machines. Persons with mild cognitive impairment were less likely to use all devices than those with no impairment. Higher socioeconomic status and education were associated with use of more complicated devices. Urban respondents were more likely than rural ones to use most devices. Conclusion Technology use by very old community-dwelling elderly is common. There are significant differences in use between rural and urban elderly. PMID:19478400

Time-temperature-stress capabilities of composite materials for advanced supersonic technology application

NASA Technical Reports Server (NTRS)

Kerr, James R.; Haskins, James F.

1987-01-01

Advanced composites will play a key role in the development of the technology for the design and fabrication of future supersonic vehicles. However, incorporating the material into vehicle usage is contingent on accelerating the demonstration of service capacity and design technology. Because of the added material complexity and lack of extensive data, laboratory replication of the flight service will provide the most rapid method to document the airworthiness of advanced composite systems. Consequently, a laboratory program was conducted to determine the time-temperature-stress capabilities of several high temperature composites. Tests included were thermal aging, environmental aging, fatigue, creep, fracture, tensile, and real-time flight simulation exposure. The program had two phases. The first included all the material property determinations and aging and simulation exposures up through 10,000 hours. The second continued these tests up to 50,000 cumulative hours. This report presents the results of the Phase 1 baseline and 10,000-hr aging and flight simulation studies, the Phase 2 50,000-hr aging studies, and the Phase 2 flight simulation tests, some of which extended to almost 40,000 hours.

Zircon Age Distributions Provide Magma Fluxes in the Earth's Crust

NASA Astrophysics Data System (ADS)

Caricchi, L.; Simpson, G.; Schaltegger, U.

2014-12-01

Magma fluxes control the growth of continents, the frequency and magnitude of volcanic eruptions and are important for the genesis of magmatic ore deposits. A significant part of the magma produced in the Earth's mantle solidifies at depth and this limits our capability of determining magma fluxes, which, in turn, compromises our ability to establish a link between global heat transfer and large-scale geological processes. Using thermal modelling in combination with high precision zircon dating we show that populations of zircon ages provide an accurate mean to retrieve magma fluxes. The characteristics of zircon age populations vary significantly and systematically as function of the flux and total volume of magma accumulated at depth. This new approach provides results that are identical to independent determinations of magma fluxes and volumes of magmatic systems. The analysis of existing age population datasets by our method highlights that porphyry-type deposits, plutons and large eruptions each require magma input over different timescales at characteristic average fluxes.

Accounting for Age Uncertainty in Growth Modeling, the Case Study of Yellowfin Tuna (Thunnus albacares) of the Indian Ocean

PubMed Central

Dortel, Emmanuelle; Massiot-Granier, Félix; Rivot, Etienne; Million, Julien; Hallier, Jean-Pierre; Morize, Eric; Munaron, Jean-Marie; Bousquet, Nicolas; Chassot, Emmanuel

2013-01-01

Age estimates, typically determined by counting periodic growth increments in calcified structures of vertebrates, are the basis of population dynamics models used for managing exploited or threatened species. In fisheries research, the use of otolith growth rings as an indicator of fish age has increased considerably in recent decades. However, otolith readings include various sources of uncertainty. Current ageing methods, which converts an average count of rings into age, only provide periodic age estimates in which the range of uncertainty is fully ignored. In this study, we describe a hierarchical model for estimating individual ages from repeated otolith readings. The model was developed within a Bayesian framework to explicitly represent the sources of uncertainty associated with age estimation, to allow for individual variations and to include knowledge on parameters from expertise. The performance of the proposed model was examined through simulations, and then it was coupled to a two-stanza somatic growth model to evaluate the impact of the age estimation method on the age composition of commercial fisheries catches. We illustrate our approach using the saggital otoliths of yellowfin tuna of the Indian Ocean collected through large-scale mark-recapture experiments. The simulation performance suggested that the ageing error model was able to estimate the ageing biases and provide accurate age estimates, regardless of the age of the fish. Coupled with the growth model, this approach appeared suitable for modeling the growth of Indian Ocean yellowfin and is consistent with findings of previous studies. The simulations showed that the choice of the ageing method can strongly affect growth estimates with subsequent implications for age-structured data used as inputs for population models. Finally, our modeling approach revealed particularly useful to reflect uncertainty around age estimates into the process of growth estimation and it can be applied to any study relying on age estimation. PMID:23637773

Tephra layers of blind Spring Valley and related upper pliocene and pleistocene tephra layers, California, Nevada, and Utah: isotopic ages, correlation, and magnetostratigraphy

USGS Publications Warehouse

Sarna-Wojcicki, Andrei M.; Reheis, Marith C.; Pringle, Malcolm S.; Fleck, Robert J.; Burbank, Doug; Meyer, Charles E.; Slate, Janet L.; Wan, Elmira; Budahn, James R.; Troxel, Bennie; Walker, James P.

2005-01-01

Numerical ages have been determined for a stratigraphic sequence of silicic tephra layers exposed at the Cowan Pumice Mine in Blind Spring Valley, near Benton Hot Springs, east-central California, as well as at Chalk Cliffs, north of Bishop, Calif. The tephra layers at these sites were deposited after eruptions from nearby sources, most of them from near Glass Mountain, and some from unknown sources. The ages were determined primarily by the laser-fusion 40Ar/39Ar method, mostly on sanidine feldspar; two were determined by conventional K-Ar analysis on obsidian clasts. These tephra layers, all underlying the Bishop ash bed and listed in order of concordant age and stratigraphic position, are: Tephra Unit Method Material Age Bishop Tuff (air-fall pumice) Ar/Ar sanidine 0.759?0.002 Ma* Upper tuffs of Glass Mountain Ar/Ar sanidine 0.87?0.02 Ma Upper tuffs of Glass Mountain Ar/Ar sanidine 1.13?0.19 Ma Lower tuffs of Glass Mountain K-Ar obsidian 1.86?0.09 Ma (avg of 2 dates) Ar/Ar sanidine 1.92?0.02 Ma (avg of 2 dates) Tuffs of Blind Spring Valley Ar/Ar sanidine 2.135?0.02 to sanidine 2.219?0.006 Ma (10 dates) Tuffs of Benton Hot Springs Ar/Ar plagioclase 2.81?0.02 Ma *Date published previously The above tephra layers were also petrographically examined and the volcanic glass shards of the layers were chemically analyzed using the electron microprobe and, for some samples, instrumental neutron activation analysis and X-ray fluorescence. The same types of chemical and petrographic analyses were conducted on stratigraphic sequences of tephra layers of suspected upper Pliocene and Pleistocene age in several past and present depositional basins within the region outside of Blind Spring Valley. Chemical characterization, combined with additional dates and with magnetostratigraphy of thick sections at two of the distal sites, allow correlation of the tephra layers at the Cowan Pumice Mine with layers present at the distal sites and provide age constraints for other intercalated tephra layers and sediments for which age data were previously lacking. The identification at several sections of the widespread Huckleberry Ridge ash bed, derived from the Yellowstone eruptive source area in Wyoming, as well as a new 40Ar/39Ar age on this ash bed from a proximal locality, provide additional age constraints to several of the distal sections. The dated or temporally bracketed distal units, in order of concordant age and stratigraphic position, are: Tephra Unit Method Material Age Tephra layers of Glass Mountain (undiff.) P-mag.*; correlation N/A 1.78 , 1.96, 1.96, 2.22, 2.57, <2.89 Ma Tephra layers of Benton Hot Springs Ar/Ar; correlation plagioclase 2.89?0.03 Ma *Magnetostratigraphic polarity determination At the Cowan Pumice Mine, only a partial section of the eruptive record is preserved, but the best materials for laser-fusion 40Ar/39Ar and other isotopic dating methods were obtained. In the more distal Willow Wash and Confidence Hills sections, both persistent depositional basins for most of late Pliocene time, more complete sections of upper Pliocene tephra layers were preserved. In the region of Glass Mountain, the tephra layers that make up each of the mapped and dated pyroclastic units are multiple and complex, but a progressive simplification of the stratigraphy away from the source area was observed for more distal sites in southern and southwestern California and in Utah. This progressive

Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures

PubMed Central

Angst, Ueli M.; Boschmann, Carolina; Wagner, Matthias; Elsener, Bernhard

2017-01-01

The aging of reinforced concrete infrastructure in developed countries imposes an urgent need for methods to reliably assess the condition of these structures. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation. While it is well known that the ability of a structure to withstand corrosion depends strongly on factors such as the materials used or the age, it is common practice to rely on threshold values stipulated in standards or textbooks. These threshold values for corrosion initiation (Ccrit) are independent of the actual properties of a certain structure, which clearly limits the accuracy of condition assessments and service life predictions. The practice of using tabulated values can be traced to the lack of reliable methods to determine Ccrit on-site and in the laboratory. Here, an experimental protocol to determine Ccrit for individual engineering structures or structural members is presented. A number of reinforced concrete samples are taken from structures and laboratory corrosion testing is performed. The main advantage of this method is that it ensures real conditions concerning parameters that are well known to greatly influence Ccrit, such as the steel-concrete interface, which cannot be representatively mimicked in laboratory-produced samples. At the same time, the accelerated corrosion test in the laboratory permits the reliable determination of Ccrit prior to corrosion initiation on the tested structure; this is a major advantage over all common condition assessment methods that only permit estimating the conditions for corrosion after initiation, i.e., when the structure is already damaged. The protocol yields the statistical distribution of Ccrit for the tested structure. This serves as a basis for probabilistic prediction models for the remaining time to corrosion, which is needed for maintenance planning. This method can potentially be used in material testing of civil infrastructures, similar to established methods used for mechanical testing. PMID:28892023

Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures.

PubMed

Angst, Ueli M; Boschmann, Carolina; Wagner, Matthias; Elsener, Bernhard

2017-08-31

The aging of reinforced concrete infrastructure in developed countries imposes an urgent need for methods to reliably assess the condition of these structures. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation. While it is well known that the ability of a structure to withstand corrosion depends strongly on factors such as the materials used or the age, it is common practice to rely on threshold values stipulated in standards or textbooks. These threshold values for corrosion initiation (Ccrit) are independent of the actual properties of a certain structure, which clearly limits the accuracy of condition assessments and service life predictions. The practice of using tabulated values can be traced to the lack of reliable methods to determine Ccrit on-site and in the laboratory. Here, an experimental protocol to determine Ccrit for individual engineering structures or structural members is presented. A number of reinforced concrete samples are taken from structures and laboratory corrosion testing is performed. The main advantage of this method is that it ensures real conditions concerning parameters that are well known to greatly influence Ccrit, such as the steel-concrete interface, which cannot be representatively mimicked in laboratory-produced samples. At the same time, the accelerated corrosion test in the laboratory permits the reliable determination of Ccrit prior to corrosion initiation on the tested structure; this is a major advantage over all common condition assessment methods that only permit estimating the conditions for corrosion after initiation, i.e., when the structure is already damaged. The protocol yields the statistical distribution of Ccrit for the tested structure. This serves as a basis for probabilistic prediction models for the remaining time to corrosion, which is needed for maintenance planning. This method can potentially be used in material testing of civil infrastructures, similar to established methods used for mechanical testing.

[The use of biological age on mental work capacity model in accelerated aging assessment of professional lorry-drivers].

PubMed

Bashkireva, A S

2012-01-01

The studies of biological age, aging rate, mental work capacity in professional drivers were conducted. The examination revealed peculiarities of system organization of functions determining the mental work capacity levels. Dynamics of the aging process of professional driver's organism in relation with calendar age and driving experience were shown using the biological age model. The results point at the premature decrease of the mental work capacity in professional drivers. It was proved, that premature age-related changes of physiologic and psychophysiologic indices in drivers are just "risk indicators", while long driving experience is a real risk factor, accelerating the aging process. The "risk group" with manifestations of accelerating aging was observed in 40-49-year old drivers with 15-19 years of professional experience. The expediency of using the following methods for the age rate estimation according to biologic age indices and necessity of prophylactic measures for premature and accelerated aging prevention among working population was demonstrated.

Brush head composition, wear profile, and cleaning efficacy: an assessment of three electric brush heads using in vitro methods.

PubMed

Kaiser, Eva; Meyners, Michael; Markgraf, Dirk; Stoerkel, Ulrich; von Koppenfels, Roxana; Adam, Ralf; Soukup, Martin; Wehrbein, Heinrich; Erbe, Christina

2014-01-01

The objective of this research was to evaluate a current store brand (SB) brush head for composition/physical characteristics, Wear Index (WI), and cleaning efficacy versus the previous SB brush head refill design (SB control) and the Oral-B Precision Clean brush head (positive control, PC). This research consisted of three parts: 1) Analytical analysis using Fourier Transform Infrared (FT-IR) spectrometry to evaluate the chemical composition of the current SB brush head bristles relative to the SB control. In addition, physical parameters such as bristle count and diameter were determined. 2) Wear Index (WI) investigation to determine the Wear Index scores of in vitro-aged brush heads at four weeks (one month) and 13 weeks (three months) by a trained investigator. To "age" the brush heads, a robot system was used as a new alternative in vitro method to simulate aging by consumer use. 3) Robot testing to determine the cleaning performance of in vitro-aged brush heads, comparing one month-aged current SB brush heads with the SB control (one and three months-aged) and the PC brush heads (three months-aged) in a standardized fashion. 1) FT-IR analysis revealed that the chemical composition of the current and control SB refill brush heads is identical. In terms of physical parameters, the current SB brush head has 12% more bristles and a slightly oval brush head compared to the round brush head of the SB control. 2) Wear Index analysis showed there was no difference in the one month-aged current SB brush head versus the one month-aged SB control (1.67 vs. 1.50, p = 0.65) or versus the three months-aged PC brush head (1.67 vs. 1.50, p = 0.65). The one month-aged current SB brush head demonstrated statistically significantly less wear than the three months-aged SB control (1.67 vs. 2.67, p = 0.01). 3) Analysis of cleaning efficacy shows that the one month-aged current SB brush head had improved cleaning performance over the one month-aged SB control brush head (p < 0.05), despite no statistically significant difference in wear. Both the one month-aged current and control SB brush heads showed statistically significantly lower cleaning performance compared to the three months-aged PC brush heads (p < 0.01). While the current SB brush head showed improved cleaning over the SB control, it demonstrated significantly lower durability and cleaning in comparison to the PC brush head. Dental professionals should be aware of these differences, both in durability and in cleaning performance, when recommending brush heads to their patients.

Use of Brain MRI Atlases to Determine Boundaries of Age-Related Pathology: The Importance of Statistical Method

PubMed Central

Dickie, David Alexander; Job, Dominic E.; Gonzalez, David Rodriguez; Shenkin, Susan D.; Wardlaw, Joanna M.

2015-01-01

Introduction Neurodegenerative disease diagnoses may be supported by the comparison of an individual patient’s brain magnetic resonance image (MRI) with a voxel-based atlas of normal brain MRI. Most current brain MRI atlases are of young to middle-aged adults and parametric, e.g., mean ±standard deviation (SD); these atlases require data to be Gaussian. Brain MRI data, e.g., grey matter (GM) proportion images, from normal older subjects are apparently not Gaussian. We created a nonparametric and a parametric atlas of the normal limits of GM proportions in older subjects and compared their classifications of GM proportions in Alzheimer’s disease (AD) patients. Methods Using publicly available brain MRI from 138 normal subjects and 138 subjects diagnosed with AD (all 55–90 years), we created: a mean ±SD atlas to estimate parametrically the percentile ranks and limits of normal ageing GM; and, separately, a nonparametric, rank order-based GM atlas from the same normal ageing subjects. GM images from AD patients were then classified with respect to each atlas to determine the effect statistical distributions had on classifications of proportions of GM in AD patients. Results The parametric atlas often defined the lower normal limit of the proportion of GM to be negative (which does not make sense physiologically as the lowest possible proportion is zero). Because of this, for approximately half of the AD subjects, 25–45% of voxels were classified as normal when compared to the parametric atlas; but were classified as abnormal when compared to the nonparametric atlas. These voxels were mainly concentrated in the frontal and occipital lobes. Discussion To our knowledge, we have presented the first nonparametric brain MRI atlas. In conditions where there is increasing variability in brain structure, such as in old age, nonparametric brain MRI atlases may represent the limits of normal brain structure more accurately than parametric approaches. Therefore, we conclude that the statistical method used for construction of brain MRI atlases should be selected taking into account the population and aim under study. Parametric methods are generally robust for defining central tendencies, e.g., means, of brain structure. Nonparametric methods are advisable when studying the limits of brain structure in ageing and neurodegenerative disease. PMID:26023913

Determination of efficacy of fingermark enhancement reagents; the use of propyl chloroformate for the derivatization of fingerprint amino acids extracted from paper.

PubMed

Mink, Tineke; Voorhaar, Annelies; Stoel, Reinoud; de Puit, Marcel

2013-09-01

The analysis of the constituents of fingerprints has been described numerous times, mainly with the purpose of determining the aging effect on fingerprints or showing the differences between donors or groups of donors. In this paper we describe the use of derivatized amino acids to determine the efficacy of the visualization reagents 1,8-diazafluoren-9-one (DFO) and ninhydrin. At present certain conditions are used for the application of these reagents, as determined by trial-and-error investigations, to the effect on fingerprints. The recovery of amino acids from a porous surface can be used as a measure for the efficacy of a visualization agent. In this paper we describe a method for the determination of the amount of amino acid left after reaction with well known fingerprint visualization reagents. This will allow a more scientific approach to method development for fingermark enhancement techniques. Furthermore, investigations on the influence of the concentration of fingermark amino acids, the order of application of and exposure time to reagents and the influence of age of the amino acids were carried out. These studies have resulted in a broader understanding of the mechanism involved in visualization of fingermarks using DFO and ninhydrin. Copyright © 2013 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

The 2017 Nobel Prize in Chemistry: cryo-EM comes of age.

PubMed

Shen, Peter S

2018-03-01

The 2017 Nobel Prize in Chemistry was awarded to Jacques Dubochet, Joachim Frank, and Richard Henderson for "developing cryo-electron microscopy (cryo-EM) for the high-resolution structure determination of biomolecules in solution." This feature article summarizes some of the major achievements leading to the development of cryo-EM and recent technological breakthroughs that have transformed the method into a mainstream tool for structure determination.

Determinants of Intensity of Participation in Leisure and Recreational Activities by Children with Cerebral Palsy

ERIC Educational Resources Information Center

Palisano, Robert J.; Chiarello, Lisa A.; Orlin, Margo; Oeffinger, Donna; Polansky, Marcy; Maggs, Jill; Bagley, Anita; Gorton, George

2011-01-01

Aim: To test a model of child, family, and service determinants of intensity of participation in leisure and recreational activities by children with cerebral palsy (CP). Method: Participants were 288 children with CP, age range 6 to 12 years (mean 9y 8mo, SD 2y), and their parents from seven children's hospitals. The sample comprised 166 (57.6%)…

The mass and age of the first SONG target: the red giant 46 LMi

NASA Astrophysics Data System (ADS)

Frandsen, S.; Fredslund Andersen, M.; Brogaard, K.; Jiang, C.; Arentoft, T.; Grundahl, F.; Kjeldsen, H.; Christensen-Dalsgaard, J.; Weiss, E.; Pallé, P.; Antoci, V.; Kjærgaard, P.; Sørensen, A. N.; Skottfelt, J.; Jørgensen, U. G.

2018-05-01

Context. The Stellar Observation Network Group (SONG) is an initiative to build a worldwide network of 1m telescopes with high-precision radial-velocity spectrographs. Here we analyse the first radial-velocity time series of a red-giant star measured by the SONG telescope at Tenerife. The asteroseismic results demonstrate a major increase in the achievable precision of the parameters for red-giant stars obtainable from ground-based observations. Reliable tests of the validity of these results are needed, however, before the accuracy of the parameters can be trusted. Aims: We analyse the first SONG time series for the star 46 LMi, which has a precise parallax and an angular diameter measured from interferometry, and therefore a good determination of the stellar radius. We use asteroseismic scaling relations to obtain an accurate mass, and modelling to determine the age. Methods: A 55-day time series of high-resolution, high S/N spectra were obtained with the first SONG telescope. We derive the asteroseismic parameters by analysing the power spectrum. To give a best guess on the large separation of modes in the power spectrum, we have applied a new method which uses the scaling of Kepler red-giant stars to 46 LMi. Results: Several methods have been applied: classical estimates, seismic methods using the observed time series, and model calculations to derive the fundamental parameters of 46 LMi. Parameters determined using the different methods are consistent within the uncertainties. We find the following values for the mass M (scaling), radius R (classical), age (modelling), and surface gravity (combining mass and radius): M = 1.09 ± 0.04M⊙, R = 7.95 ± 0.11R⊙ age t = 8.2 ± 1.9 Gy, and logg = 2.674 ± 0.013. Conclusions: The exciting possibilities for ground-based asteroseismology of solar-like oscillations with a fully robotic network have been illustrated with the results obtained from just a single site of the SONG network. The window function is still a severe problem which will be solved when there are more nodes in the network. Based on observations made with the Hertzsprung SONG telescope operated at the Spanish Observatorio del Teide on the island of Tenerife by the Aarhus and Copenhagen Universities and by the Instituto de Astrofísica de Canarias.

SEGMA: An Automatic SEGMentation Approach for Human Brain MRI Using Sliding Window and Random Forests

PubMed Central

Serag, Ahmed; Wilkinson, Alastair G.; Telford, Emma J.; Pataky, Rozalia; Sparrow, Sarah A.; Anblagan, Devasuda; Macnaught, Gillian; Semple, Scott I.; Boardman, James P.

2017-01-01

Quantitative volumes from brain magnetic resonance imaging (MRI) acquired across the life course may be useful for investigating long term effects of risk and resilience factors for brain development and healthy aging, and for understanding early life determinants of adult brain structure. Therefore, there is an increasing need for automated segmentation tools that can be applied to images acquired at different life stages. We developed an automatic segmentation method for human brain MRI, where a sliding window approach and a multi-class random forest classifier were applied to high-dimensional feature vectors for accurate segmentation. The method performed well on brain MRI data acquired from 179 individuals, analyzed in three age groups: newborns (38–42 weeks gestational age), children and adolescents (4–17 years) and adults (35–71 years). As the method can learn from partially labeled datasets, it can be used to segment large-scale datasets efficiently. It could also be applied to different populations and imaging modalities across the life course. PMID:28163680

Influence of the yeast strain on the changes of the amino acids, peptides and proteins during sparkling wine production by the traditional method.

PubMed

Martínez-Rodríguez, A J; Carrascosa, A V; Martín-Alvarez, P J; Moreno-Arribas, V; Polo, M C

2002-12-01

The influence of five yeast strains on the nitrogen fractions, amino acids, peptides and proteins, during 12 months of aging of sparkling wines produced by the traditional or Champenoise method, was studied. High-performance liquid chromatography (HPLC) techniques were used for analysis of the amino acid and peptide fractions. Proteins plus polypeptides were determined by the colorimetric Bradford method. Four main stages were detected in the aging of wines with yeast. In the first stage, a second fermentation took place; amino acids and proteins plus polypeptides diminished, and peptides were liberated. In the second stage, there was a release of amino acids and proteins, and peptides were degraded. In the third stage, the release of proteins and peptides predominated. In the fourth stage, the amino acid concentration diminished. The yeast strain used influenced the content of free amino acids and peptides and the aging time in all the nitrogen fractions.

How old are lunar lobate scarps? 1. Seismic resetting of crater size-frequency distributions

NASA Astrophysics Data System (ADS)

van der Bogert, Carolyn H.; Clark, Jaclyn D.; Hiesinger, Harald; Banks, Maria E.; Watters, Thomas R.; Robinson, Mark S.

2018-05-01

Previous studies have estimated the ages of lunar lobate scarps, some of the youngest tectonic landforms on the Moon, based on the estimated life-times of their fresh morphologies and associated small graben, using crater degradation ages, or via buffered and traditional crater size-frequency distribution (CSFD) measurements. Here, we reexamine five scarps previously dated by Binder and Gunga (1985) with crater degradation ages to benchmark the evaluation of both the buffered and traditional CSFD approaches for determination of absolute model ages (AMAs) at scarps. Both CSFD methods yield similar ages for each individual scarp, indicating that fault activity not only can be measured on the scarp itself, but also in the surrounding terrain - an indication that tectonic activity causes surface renewal both adjacent to and even kilometers distant from scarps. Size-frequency variations in the regions surrounding the scarps are thus useful for studying the extent and severity of the ground motion caused by coseismic slip events during scarp formation. All age determination approaches continue to indicate that lunar lobate scarps were active in the late Copernican, with some scarps possibly experiencing activity within the last 100 Ma.

How Old are Lunar Lobate Scarps? 1. Seismic Resetting of Crater Size-Frequency Distributions

NASA Technical Reports Server (NTRS)

Van Der Bogert, Carolyn H.; Clark, Jaclyn D.; Hiesinger, Harald; Banks, Maria E.; Watters, Thomas R.; Robinson, Mark S.

2018-01-01

Previous studies have estimated the ages of lunar lobate scarps, some of the youngest tectonic landforms on the Moon, based on the estimated life-times of their fresh morphologies and associated small graben, using crater degradation ages, or via buffered and traditional crater size-frequency distribution (CSFD) measurements. Here, we reexamine five scarps previously dated by Binder and Gunga (1985) with crater degradation ages to benchmark the evaluation of both the buffered and traditional CSFD approaches for determination of absolute model ages (AMAs) at scarps. Both CSFD methods yield similar ages for each individual scarp, indicating that fault activity not only can be measured on the scarp itself, but also in the surrounding terrain - an indication that tectonic activity causes surface renewal both adjacent to and even kilometers distant from scarps. Size-frequency variations in the regions surrounding the scarps are thus useful for studying the extent and severity of the ground motion caused by coseismic slip events during scarp formation. All age determination approaches continue to indicate that lunar lobate scarps were active in the late Copernican, with some scarps possibly experiencing activity within the last 100 Ma.

Recruitment methods in a clinical trial of provoked vulvodynia: Predictors of enrollment.

PubMed

Bachour, Candi C; Bachmann, Gloria A; Foster, David C; Wan, Jim Y; Rawlinson, Leslie A; Brown, Candace S

2017-02-01

Successful recruitment in clinical trials for chronic pain conditions is challenging, especially in women with provoked vulvodynia due to reluctance in discussing pain associated with sexual intercourse. The most successful recruitment methods and the characteristics of women reached with these methods are unknown. To compare the effectiveness and efficiency of four recruitment methods and to determine socioeconomic predictors for successful enrollment in a National Institutes of Health-sponsored multicenter clinical trial evaluating a gabapentin intervention in women with provoked vulvodynia. Recruitment methods utilized mass mailing, media, clinician referrals and community outreach. Effectiveness (number of participants enrolled) and efficiency (proportion screened who enrolled) were determined. Socioeconomic variables including race, educational level, annual household income, relationship status, age, menopausal status and employment status were also evaluated regarding which recruitment strategies were best at targeting specific cohorts. Of 868 potential study participants, 219 were enrolled. The most effective recruitment method in enrolling participants was mass mailing ( p < 0.001). There were no statistically significant differences in efficiency between recruitment methods ( p = 0.11). Relative to clinician referral, black women were 13 times as likely to be enrolled through mass mailing (adjusted odds ratio 12.5, 95% confidence interval, 3.6-43.1) as white women. There were no differences in enrollment according to educational level, annual income, relationship status, age, menopausal status, or employment status and recruitment method. In this clinical trial, mass mailing was the most effective recruitment method. Race of participants enrolled in a provoked vulvodynia trial was related to the recruitment method.

Determination of Zn/Cu ratio and oligoelements in serum samples by total reflection X-ray fluorescence spectrometry for cancer diagnosis

NASA Astrophysics Data System (ADS)

Marcó P., L. M.; Jiménez, E.; Hernández C., E. A.; Rojas, A.; Greaves, E. D.

2001-11-01

The method of quantification using the Compton peak as an internal standard, developed in a previous work, was applied to the routine determination of Fe, Cu, Zn and Se in serum samples from normal individuals and cancer patients by total reflection X-ray fluorescence spectrometry. Samples were classified according to age and sex of the donor, in order to determine reference values for normal individuals. Results indicate that the Zn/Cu ratio and the Cu concentration could prove to be useful tools for cancer diagnosis. Significant differences in these parameters between the normal and cancer group were found for all age ranges. The multielemental character of the technique, coupled with the small amounts of sample required and the short analysis time make it a valuable tool in clinical analysis.

Progression of lumbar disc degeneration over a decade: a heritability study

PubMed Central

Williams, Frances M K; Popham, Maria; Sambrook, Philip N; Jones, Annette F; Spector, Tim D; MacGregor, Alex J

2011-01-01

Objectives Lumbar disc degeneration (LDD) is prevalent, age-related and contributes to low back pain. Cross-sectional LDD as determined by MRI scan is known to be highly heritable. The authors postulated that the rate of progression might also be controlled by genetic factors. Methods A 10-year follow-up of MRI-determined LDD was performed in 234 pairs of twin volunteers in the UK and Australia, comprising 90 monozygotic pairs and 144 dizygotic same-sex twin pairs. Of the total sample, 95% were female. The mean age at baseline was 53.3 years (range 32.3–69.5). The rate of progression was calculated and, because the effect of age was non-linear, the sample was divided into age strata and heritability estimated for each trait's progression. Results All MRI-determined traits worsened significantly over the period of follow-up (p<0.0001 for each). Change in disc height was not heritable at any age while posterior disc bulge was heritable across all age categories (range 28–53%), with higher heritability in those over 60 years. Change in disc signal intensity and anterior osteophytes were found to be heritable only in those aged under 50 years at baseline (heritability estimates 76% (95% CI 44% to 100%) and 74% (42% to 100%), respectively). Conclusions Longitudinal change in LDD traits is heritable for all traits except disc height, but there is a significant influence of age, which varies across traits. Future studies to define the genetic variants influencing LDD progression should examine MRI traits individually and in women should focus on those under 50 years of age. PMID:21402564

The health of Inuit children under age 6 in Canada

PubMed Central

Findlay, Leanne C.; Janz, Teresa A.

2012-01-01

Objectives Previous research has suggested that Inuit children experience poor health as compared to their non-Aboriginal counterparts, although social determinants such as family and social conditions, lifestyle or behaviour, and cultural factors may be at play. The purpose of the current study was to examine the parent-reported health of Inuit children under 6 years of age living in Canada. Study design and methods Data from the 2006 Aboriginal Children's Survey were used to examine measures of Inuit child health as rated by parents including child health, limitations to physical activity, chronic conditions, ear infections, and dental problems. Associations between social determinants of health and parent-rated Inuit child health were also explored. Results Most Inuit children under age 6 were reported by their parents or guardians to be in excellent or very good health. The most common chronic conditions identified were asthma, speech and language difficulties, allergies, lactose intolerance, and hearing impairment. Several social determinants of health were associated with child health, including parental education, household income, breastfeeding, and perceived housing conditions. Conclusions The findings show that social determinants of health, including both socio-economic and household characteristics, are associated with Inuit child health. PMID:22973565

Determination of LEDs degradation with entropy generation rate

NASA Astrophysics Data System (ADS)

Cuadras, Angel; Yao, Jiaqiang; Quilez, Marcos

2017-10-01

We propose a method to assess the degradation and aging of light emitting diodes (LEDs) based on irreversible entropy generation rate. We degraded several LEDs and monitored their entropy generation rate ( S ˙ ) in accelerated tests. We compared the thermoelectrical results with the optical light emission evolution during degradation. We find a good relationship between aging and S ˙ (t), because S ˙ is both related to device parameters and optical performance. We propose a threshold of S ˙ (t) as a reliable damage indicator of LED end-of-life that can avoid the need to perform optical measurements to assess optical aging. The method lays beyond the typical statistical laws for lifetime prediction provided by manufacturers. We tested different LED colors and electrical stresses to validate the electrical LED model and we analyzed the degradation mechanisms of the devices.

Vulnerability to unhealthy behaviours across different age groups in Swedish Adolescents: a cross-sectional study

PubMed Central

Paulsson Do, Ulrica; Edlund, Birgitta; Stenhammar, Christina; Westerling, Ragnar

2014-01-01

Purpose: There is lack of evidence on the effects of health-promoting programmes among adolescents. Health behaviour models and studies seldom compare the underlying factors of unhealthy behaviours between different adolescent age groups. The main objective of this study was to investigate factors including sociodemographic parameters that were associated with vulnerability to health-damaging behaviours and non-adoption of health-enhancing behaviours in different adolescent age groups. Methods: A survey was conducted among 10,590 pupils in the age groups of 13–14, 15–16 and 17–18 years. Structural equation modelling was performed to determine whether health-damaging behaviours (smoking and alcohol consumption) and non-adoption of health-enhancing behaviours (regular meal habits and physical activity) shared an underlying vulnerability. This method was also used to determine whether gender and socio-economic status were associated with an underlying vulnerability to unhealthy behaviours. Results: The findings gave rise to three models, which may reflect the underlying vulnerability to health-damaging behaviours and non-adoption of health-enhancing behaviours at different ages during adolescence. The four behaviours shared what was interpreted as an underlying vulnerability in the 15–16-year-old age group. In the youngest group, all behaviours except for non-participation in physical activity shared an underlying vulnerability. Similarly, alcohol consumption did not form part of the underlying vulnerability in the oldest group. Lower socio-economic status was associated with an underlying vulnerability in all the age groups; female gender was associated with vulnerability in the youngest adolescents and male gender among the oldest adolescents. Conclusions: These results suggest that intervention studies should investigate the benefits of health-promoting programmes designed to prevent health-damaging behaviours and promote health-enhancing behaviours in adolescents of different ages. Future studies should examine other factors that may contribute to the underlying vulnerability in different age groups. PMID:25750783

Paleomagnetism of Holocene lava flows from the Reykjanes Peninsula and the Tungnaá lava sequence (Iceland): implications for flow correlation and ages

NASA Astrophysics Data System (ADS)

Pinton, Annamaria; Giordano, Guido; Speranza, Fabio; Þórðarson, Þorvaldur

2018-01-01

The impact of Holocene eruptive events from hot spots like Iceland may have had significant global implications; thus, dating and knowledge of past eruptions chronology is important. However, at high-latitude volcanic islands, the paucity of soils severely limits 14C dating, while the poor K content of basalts strongly restricts the use of K/Ar and Ar/Ar methods. Even tephrochronology, based on 14C age determinations, refers to layers that rarely lie directly above lava flows to be dated. We report on the paleomagnetic dating of 25 sites from the Reykjanes Peninsula and the Tungnaá lava sequence of Iceland. The gathered paleomagnetic directions were compared with the available reference paleosecular variation curves of the Earth magnetic field to obtain the possible emplacement age intervals. To test the method's validity, we sampled the precisely dated Laki (1783-1784 AD) and Eldgjà (934-938 AD) lavas. The age windows obtained for these events encompass the true flow ages. For sites from the Reykjanes peninsula and the Tugnaá lava sequence, we derived multiple possible eruption events and ages. In the Reykjanes peninsula, we propose an older emplacement age (immediately following the 870 AD Iceland Settlement age) for Ogmundarhraun and Kapelluhraun lava fields. For pre-historical (older than the settlement age) Tugnaá eruptions, the method has a dating precision of 300-400 years which allows an increase of the detail in the chronostratigraphy and distribution of lavas in the Tugnaá sequence.

Estimating the Time to Benefit for Preventive Drugs with the Statistical Process Control Method: An Example with Alendronate.

PubMed

van de Glind, Esther M M; Willems, Hanna C; Eslami, Saeid; Abu-Hanna, Ameen; Lems, Willem F; Hooft, Lotty; de Rooij, Sophia E; Black, Dennis M; van Munster, Barbara C

2016-05-01

For physicians dealing with patients with a limited life expectancy, knowing the time to benefit (TTB) of preventive medication is essential to support treatment decisions. The aim of this study was to investigate the usefulness of statistical process control (SPC) for determining the TTB in relation to fracture risk with alendronate versus placebo in postmenopausal women. We performed a post hoc analysis of the Fracture Intervention Trial (FIT), a randomized, controlled trial that investigated the effect of alendronate versus placebo on fracture risk in postmenopausal women. We used SPC, a statistical method used for monitoring processes for quality control, to determine if and when the intervention group benefited significantly more than the control group. SPC discriminated between the normal variations over time in the numbers of fractures in both groups and the variations that were attributable to alendronate. The TTB was defined as the time point from which the cumulative difference in the number of clinical fractures remained greater than the upper control limit on the SPC chart. For the total group, the TTB was defined as 11 months. For patients aged ≥70 years, the TTB was 8 months [absolute risk reduction (ARR) = 1.4%]; for patients aged <70 years, it was 19 months (ARR = 0.7%). SPC is a clear and understandable graphical method to determine the TTB. Its main advantage is that there is no need to define a prespecified time point, as is the case in traditional survival analyses. Prescribing alendronate to patients who are aged ≥70 years is useful because the TTB shows that they will benefit after 8 months. Investigators should report the TTB to simplify clinical decision making.

Importance of charcoal in determining the age and chemistry of organic carbon in surface soils

NASA Astrophysics Data System (ADS)

Krull, Evelyn S.; Swanston, Christopher W.; Skjemstad, Jan O.; McGowan, Janine A.

2006-12-01

Understanding the chemical character and turnover time of the oldest soil organic carbon (SOC) fraction is fundamental in deciphering soil carbon sequestration processes and the fate of soil-eroded carbon in aquatic sediments. Two main processes are thought to extend the turnover time of SOC: protection by the mineral matrix and chemical recalcitrance. Various oxidation methods have been proposed to isolate the oldest and most recalcitrant SOC fraction, which is often assumed to be black carbon (BC). However, few data have been published that confirm the chemical character of the isolated fractions. Using established and newly developed methods together with 13C-NMR spectroscopy and AMS dating, we show that protection by the mineral matrix prolonged the turnover time of SOC by tens of years, but long-term (hundreds of years) stabilization was controlled by the inherent recalcitrance of SOC, determined by the type of ecosystems. In ecosystem without significant fire occurrences, the older SOC pool was comparably small and was represented by alkyl carbon. In ecosystems with high fire frequency charcoal constituted the oldest SOC pool, and constituted up to 35% of the total SOC. By applying methods with different oxidative strengths, it was possible to isolate different age groups of charcoal with different degrees of weathering. Further substantiation of this finding could provide a much greater resolution of paleo-fire events. Our results demonstrate that fire frequency plays a dominant role in determining the chemical nature and 14C abundance of SOC and that the separation of age groups of charcoal provides a means to reconstruct detailed fire histories. Our results indicate that modeling SOC turnover, transport and sequestration for frequently burnt environments requires modification of existing models, specifying an input and decay function for the charcoal pool in different environments.

Hospitalizations for Suicide-Related Drug Poisonings and Co-Occurring Alcohol Overdoses in Adolescents (Ages 12-17) and Young Adults (Ages 18-24) in the United States, 1999-2008: Results from the Nationwide Inpatient Sample

ERIC Educational Resources Information Center

White, Aaron M.; MacInnes, Erin; Hingson, Ralph W.; Pan, I-Jen

2013-01-01

Drug poisoning is the leading method of suicide-related deaths among females and third among males in the United States. Alcohol can increase the severity of drug poisonings, yet the prevalence of alcohol overdoses in suicide-related drug poisonings (SRDP) remains unclear. Data from the Nationwide Inpatient Sample was examined to determine rates…

Parent Perceptions and Observations of Their Children with Autism Age 14-to-26 Concerning Generalization of Daily Living Skills at Home and in the Community

ERIC Educational Resources Information Center

Crosby, Patrick H.

2009-01-01

The purpose of this sequential mixed methods study was to determine if students with autism from 19-to-26 years of age who receive instruction in Daily Living Skills (DLS) class sustain, improve, or decline in their ability to generalize DLS at home and in the community. Research regarding how well students with autism from 19-to-26 years of age…

Velopharyngeal Status of Stop Consonants and Vowels Produced by Young Children with and without Repaired Cleft Palate at 12, 14, and 18 Months of Age: A Preliminary Analysis

ERIC Educational Resources Information Center

Eshghi, Marziye; Vallino, Linda D.; Baylis, Adriane L.; Preisser, John S.; Zajac, David J.

2017-01-01

Purpose: The objective was to determine velopharyngeal (VP) status of stop consonants and vowels produced by young children with repaired cleft palate (CP) and typically developing (TD) children from 12 to 18 months of age. Method: Nasal ram pressure (NRP) was monitored in 9 children (5 boys, 4 girls) with repaired CP with or without cleft lip and…

Star Formation Histories of Local Group Dwarf Galaxies. (Ludwig Biermann Award Lecture 1996)

NASA Astrophysics Data System (ADS)

Grebel, E. K.

The star formation histories of dwarf galaxies in the Local Group are reviewed. First the question of Local Group membership is considered based on various criteria. The properties of 31 (36) galaxies are consistent with likely (potential) Local Group membership. To study the star formation histories of these galaxies, a multi-parameter problem needs to be solved: Ages, metallicities, population fractions, and spatial variations must be determined, which depend crucially on the knowledge of reddening and distance. The basic methods for studying resolvable stellar populations are summarized. One method is demonstrated using the Fornax dwarf spheroidal galaxy. A comprehensive compilation of the star formation histories of dwarf irregulars, dwarf ellipticals, and dwarf spheroidals in the Local Group is presented and visualized through Hodge's population boxes. All galaxies appear to have differing fractions of old and intermediate-age populations, and those sufficiently massive and undisturbed to retain and recycle their gas are still forming stars today. Star formation has occurred either in distinct episodes or continuously over long periods of time. Metallicities and enrichment vary widely. Constraints on merger and remnant scenarios are discussed, and a unified picture based on the current knowledge is presented. Primary goals for future observations are: accurate age determinations based on turnoff photometry, detection of subpopulations distinct in age, metallicity, and/or spatial distribution; improved distances; and astrometric studies to derive orbits and constrain past and future interactions.

The Effects of the Refugee Crisis on Age Estimation Analysis over the Past 10 Years: A 16-Country Survey

PubMed Central

Sykes, Leanne; Bhayat, Ahmed; Bernitz, Herman

2017-01-01

Dental age estimation (AE) tests are routinely done on living and deceased persons. There is anecdotal evidence suggesting an increase in age estimations due to the refugee crisis. Our aim is to determine the reasons and methods for performing dental AE tests in both living and deceased individuals. Global trends in AE over the past 10 years were also investigated. A database of all forensic laboratories was obtained and an electronic questionnaire was sent to all of them. The questionnaire was self-developed and included questions on the reasons for performing AE tests, the preferred methods used in living and deceased individuals, and the people/organizations who requested these AE tests. The number of tests performed annually varied between 0 and 500 and the majority were on asylum seekers, refugees, and for adoption cases. Most units used multiple techniques to determine the age among the living, but seldom used more than three techniques for the deceased. The majority of tests were requested by coroners and the legal fraternity. There has been an increase in the number of dental AEs carried out and this has been mostly due to asylum seekers and refugees. The most common techniques for the living were variations of Demirjian’s technique while country specific techniques were used for the deceased. PMID:28608845

Determination of SB2 masses and age: introduction of the mass ratio in the Bayesian analysis

NASA Astrophysics Data System (ADS)

Giarrusso, M.; Leone, F.; Tognelli, E.; Degl'Innocenti, S.; Prada Moroni, P. G.

2018-04-01

Stellar age assignment still represents a difficult task in Astrophysics. This unobservable fundamental parameter can be estimated only through indirect methods, as well as generally the mass. Bayesian analysis is a statistical approach largely used to derive stellar properties by taking into account the available information about the quantities we are looking for. In this paper we propose to apply the method to the double-lined spectroscopic binaries (SB2), for which the only available information about masses is the observed mass ratio of the two components. We validated the method on a synthetic sample of Pre-Main Sequence (PMS) SB2 systems showing the capability of the technique to recover the simulated age and masses. Then, we applied our procedure to the PMS eclipsing binaries Parenago 1802 and RX J0529.4+0041 A, whose masses of both components are known, by treating them as SB2 systems. The estimated masses are in agreement with those dynamically measured. We conclude that the method, if based on high resolution and high signal-to-noise spectroscopy, represents a robust way to infer the masses of the very numerous SB2 systems together with their age, allowing to date the hosting astrophysical environments.

Determination of SB2 masses and age: introduction of the mass ratio in the Bayesian analysis

NASA Astrophysics Data System (ADS)

Giarrusso, M.; Leone, F.; Tognelli, E.; Degl'Innocenti, S.; Prada Moroni, P. G.

2018-07-01

Stellar age assignment still represents a difficult task in Astrophysics. This unobservable fundamental parameter can be estimated only through indirect methods, as well as generally the mass. Bayesian analysis is a statistical approach largely used to derive stellar properties by taking into account the available information about the quantities we are looking for. In this paper, we propose to apply the method to the double-lined spectroscopic binaries (SB2), for which the only available information about masses is the observed mass ratio of the two components. We validated the method on a synthetic sample of pre-main-sequence (PMS) SB2 systems showing the capability of the technique to recover the simulated age and masses. Then, we applied our procedure to the PMS eclipsing binaries Parenago 1802 and RX J0529.4+0041 A, whose masses of both components are known, by treating them as SB2 systems. The estimated masses are in agreement with those dynamically measured. We conclude that the method, if based on high resolution and high signal-to-noise spectroscopy, represents a robust way to infer the masses of the very numerous SB2 systems together with their age, allowing to date the hosting astrophysical environments.

Determination of Age-Dependent Reference Ranges for Coagulation Tests Performed Using Destiny Plus.

PubMed

Arslan, Fatma Demet; Serdar, Muhittin; Merve Ari, Elif; Onur Oztan, Mustafa; Hikmet Kozcu, Sureyya; Tarhan, Huseyin; Cakmak, Ozgur; Zeytinli, Merve; Yasar Ellidag, Hamit

2016-06-01

In order to apply the right treatment for hemostatic disorders in pediatric patients, laboratory data should be interpreted with age-appropriate reference ranges. The purpose of this study was to determining age-dependent reference range values for prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen tests, and D-dimer tests. A total of 320 volunteers were included in the study with the following ages: 1 month - 1 year (n = 52), 2 - 5 years (n = 50), 6 - 10 years (n = 48), 11 - 17 years (n = 38), and 18 - 65 years (n = 132). Each volunteer completed a survey to exclude hemostatic system disorder. Using a nonparametric method, the lower and upper limits, including 95% distribution and 90% confidence intervals, were calculated. No statistically significant differences were found between PT and aPTT values in the groups consisting of children. Thus, the reference ranges were separated into child and adult age groups. PT and aPTT values were significantly higher in the children than in the adults. Fibrinogen values in the 6 - 10 age group and the adult age group were significantly higher than in the other groups. D-dimer levels were significantly lower in those aged 2 - 17; thus, a separate reference range was established. These results support other findings related to developmental hemostasis, confirming that adult and pediatric age groups should be evaluated using different reference ranges.

Association between gestational age and bovine fetal characteristics measured by transcutaneous ultrasound over the right flank of the dairy cow.

PubMed

Hunnam, J C; Parkinson, T J; Lopez-Villalobos, N; McDougall, S

2009-09-01

To determine bovine fetal characteristics significantly associated with increasing gestational age as measured via transcutaneous ultrasonography over the right flank. The length of gestation at date of pregnancy diagnosis via transcutaneous and transrectal ultrasonography was determined for 224 dairy cattle by estimation from subsequent calving dates. A separate dataset was created for each measurable fetal characteristic (i.e. thoracic diameter, abdominal diameter, umbilical diameter, placentome length and placentome height) and risk factors significantly associated with gestational age at pregnancy diagnosis within each dataset, including the fetal characteristic, were identified. Abdominal diameter was the most frequently observed fetal characteristic and thoracic diameter was the least. Gestational age at pregnancy diagnosis (d) was significantly associated with fetal thoracic diameter (P < 0.01), abdominal diameter (P < 0.01) and umbilical diameter (P = 0.02) when measured via transcutaneous ultrasound. Within each model, sire breed, dam breed, dam age and/or calf sex were also significantly associated with gestational age. Gestational age at pregnancy diagnosis was not significantly associated with either placentome height or length (P > 0.05). Fetal thoracic diameter, abdominal diameter and umbilical diameter were found to be significantly associated with gestational age between approximate days 73 to 190 of gestation. Transcutaneous ultrasonography may prove a useful method of estimating gestational age in the absence of accurate breeding records.

Vaccination coverage and its determinants among migrant children in Guangdong, China

PubMed Central

2014-01-01

Background Guangdong province attracted more than 31 million migrants in 2010. But few studies were performed to estimate the complete and age-appropriate immunization coverage and determine risk factors of migrant children. Methods 1610 migrant children aged 12–59 months from 70 villages were interviewed in Guangdong. Demographic characteristics, primary caregiver’s knowledge and attitude toward immunization, and child’s immunization history were obtained. UTD and age-appropriate immunization rates for the following five vaccines and the overall series (1:3:3:3:1 immunization series) were assessed: one dose of BCG, three doses of DTP, OPV and HepB, one dose of MCV. Risk factors for not being UTD for the 1:3:3:3:1 immunization series were explored. Results For each antigen, the UTD immunization rate was above 71%, but the age-appropriate immunization rates for BCG, HepB, OPV, DPT and MCV were only 47.8%, 45.1%, 47.1%, 46.8% and 37.2%, respectively. The 1st dose was most likely to be delayed within them. For the 1:3:3:3:1 immunization series, the UTD immunization rate and age-appropriate immunization rate were 64.9% and 12.4% respectively. Several factors as below were significantly associated with UTD immunization. The primary caregiver’s determinants were their occupation, knowledge and attitude toward immunization. The child’s determinants were sex, Hukou, birth place, residential buildings and family income. Conclusions Alarmingly low immunization coverage of migrant children should be closely monitored by NIISS. Primary caregiver and child’s determinants should be considered when taking measures. Strategies to strengthen active out-reach activities and health education for primary caregivers needed to be developed to improve their immunization coverage. PMID:24568184

Interprofessional student teams augmenting service provision in residential aged care.

PubMed

Kent, Fiona; Lai, Francis; Beovich, Bronwyn; Dodic, Miodrag

2016-09-01

The aim of this study was to determine the usefulness of student-led interprofessional consultations within residential aged care in augmenting patient care and enhancing student education. Volunteer fourth and final year health-care students conducted interprofessional consultations. In a mixed methods design, residents' health-care changes and perspectives were collected prospectively, and student and educator perceptions were measured by survey and interview. Sixteen aged care residents were consulted by interprofessional teams. Students identified two new health issues and proposed 17 recommendations for referrals and five changes to medication management. At six-weeks follow-up, two recommendations had been acted upon clinically, and two medication changes had been implemented. Reasons for the low uptake of recommendations were determined. Residents, students and educators reported high levels of satisfaction. Residential care facilities offer a useful interprofessional learning environment. Student consultations are positively regarded by patients, students and educators and may augment existing health services. © 2016 AJA Inc.

Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices

DOEpatents

Gering, Kevin L

2013-08-27

A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.

Time-temperature-stress capabilities of composite materials for advanced supersonic technology application, phase 1

NASA Technical Reports Server (NTRS)

Kerr, J. R.; Haskins, J. F.

1980-01-01

Implementation of metal and resin matrix composites into supersonic vehicle usage is contingent upon accelerating the demonstration of service capacity and design technology. Because of the added material complexity and lack of extensive service data, laboratory replication of the flight service will provide the most rapid method of documenting the airworthiness of advanced composite systems. A program in progress to determine the time temperature stress capabilities of several high temperature composite materials includes thermal aging, environmental aging, fatigue, creep, fracture, and tensile tests as well as real time flight simulation exposure. The program has two parts. The first includes all the material property determinations and aging and simulation exposures up through 10,000 hours. The second continues these tests up to 50,000 cumulative hours. Results are presented of the 10,000 hour phase, which has now been completed.

Mallard age and sex determination from wings

USGS Publications Warehouse

Carney, S.M.; Geis, A.D.

1960-01-01

This paper describes characters on the wing plumage of the mallard that indicate age and sex. A key outlines a logical order in which to check age and sex characters on wings. This method was tested and found to be more than 95 percent reliable, although it was found that considerable practice and training with known-age specimens was required to achieve this level of accuracy....The implications of this technique and the sampling procedure it permits are discussed. Wing collections could provide information on production, and, if coupled with a banding program could permit seasonal population estimates to be calculated. In addition, representative samples of wings would provide data to check the reliability of several other waterfowl surveys.

Radiometric Ages From ODP Leg 197 Drilling Along the Emperor Seamount Chain

NASA Astrophysics Data System (ADS)

Duncan, R. A.; Huard, J.

2002-12-01

The Hawaiian-Emperor Seamount chain is the "type" example of an age-progressive, hotspot-generated intraplate volcanic lineament. However, our current knowledge of the age distribution within this province is based on radiometric ages determined several decades ago. Improvements in instrumentation, sample preparation methods and new material obtained by recent drilling warrant a re-examination of the age relations among the older Hawaiian volcanoes. We report new age determinations (40Ar-39Ar incremental heating method) on whole rocks and feldspar separates from Detroit (Sites 1203 and 1204), Nintoku (Site 1205) and Koko (Site 1206) seamounts in the Emperor chain, recovered by drilling during ODP Leg 197. Only normal magnetic polarity was observed at Sites 1203 and 1204, and biostratigraphic data assigned ages of 75-76 Ma (nanofossil zone cc22) to sediments interbedded with lava flows. Plateaus in incremental heating age spectra give a mean age for Site 1203 of 75.3 +/- 1.0 Ma (relative to biotite monitor FCT-3 at 28.04 Ma; all errors are 2s). Site 1204 lavas have produced only discordant data so far (5 samples). These new ages are significantly younger than the 81 Ma age reported by Keller et al. (1995) for Site 884 (reverse polarity lavas) on the northeastern flank of Detroit seamount, and suggest that this complex may include several large volcanoes. All volcanic units at Site 1205 exhibit reverse polarity magnetization and biostratigraphic data place the lowermost sediments close to the Eocene-Paleocene boundary. Six plateau ages from lava flows spanning the 283m cored section give a mean age of 55.6 +/- 0.2 Ma (range: 55.2-56.4 Ma), corresponding to Chron 24r. Drilling at Site 1206 intersected a 278m N-R-N sequence of lava flows. Six plateau ages give a mean age of 49.1 +/- 0.2 Ma (range: 47.9-49.7 Ma), corresponding to the Chron 21n-21r-22n sequence. Deep penetration at the three seamounts and shipboard geochemical data suggest that the main shield-post shield stages of volcano development have been sampled at each location and dated. While the overall trend is decreasing volcano age from N to S along the Emperor Seamounts, there appear to be important departures from the earlier modeled simple linear age progression.

Age Related Differences in Diffusion Tensor Indices and Fiber Architecture in the Medial and Lateral Gastrocnemius

PubMed Central

Sinha, Usha; Csapo, Robert; Malis, Vadim; Xue, Yanjie; Sinha, Shantanu

2014-01-01

Purpose To investigate age related changes in diffusion tensor indices and fiber architecture of the medial and lateral gastrocnemius (MG and LG) muscles using diffusion tensor imaging (DTI). Materials and Methods The lower leg of five young and five senior subjects was scanned at 3T and DTI indices extracted using three methods: ROI, histogram and tract based. Tracked fibers were automatically edited to ensure physiologically relevant tracks. Pennation angles were measured with respect to the deep and superficial aponeuroses of both muscles. Results The three methods provided internally consistent measures of the DTI indices (correlation coefficient in the range of 0.90-0.99). The primary, secondary and tertiary eigenvalues in the MG and LG increased significantly in the senior cohort (p<0.05), while the small increase in fractional anisotropy (FA) with age was not significant (MG/LG: p=0.39/0.85; 95% CI:[ −0.059/-0.056, 0.116/0.064]). Fiber lengths of MG fibers originating distally were significantly decreased in seniors (p<0.05) while pennation angles decreased with age in the MG and LG but this was not significant. Conclusion Fiber atrophy and increased fibrosis have opposing effects on the diffusion indices resulting in a complicated dependence with aging. Fiber architectural changes could play a role in determining aging muscle function. PMID:24771672

An Improved Version of the Cervical Vertebral Maturation (CVM) Method for the Assessment of Mandibular Growth in Deutero-Malay Sub Race

NASA Astrophysics Data System (ADS)

Oscandar, Fahmi; Malinda, Yuti; Azhari, H.; Murniati, Nani; Yeh Ong, Sing; Subiyanto; Supian, Sudradjat

2018-01-01

In this paper, Cervical Vertebral Maturation method was used to assess the mandibular growth in Deutero-Malay sub race. Twenty eight laterals Cephalometric radiographs of Deutero-Malay sub race aged 9-15 were observed. The observation used stratified random sampling by measuring the quantitative and qualitative assessment of the 2nd through 4th cervical vertebra of the subjects. It produced the diagram of developmental stages of cervical vertebrae for Deutero-Malay sub race. The diagram can be used to determine mandibular growth in term of qualitative by matching the shape of cervical vertebrae. It was obtained that the Cervical Vertebral Maturation method can be used to assess mandibular growth in Deutero-Malay sub race by matching the shape of cervical vertebrae to the diagram of developmental stages of cervical vertebrae. In addition, Cervical Vertebral Maturation method can be used to identification person’s age.

Asteroid family dynamics in the inner main belt

NASA Astrophysics Data System (ADS)

Dykhuis, Melissa Joy

The inner main asteroid belt is an important source of near-Earth objects and terrestrial planet impactors; however, the dynamics and history of this region are challenging to understand, due to its high population density and the presence of multiple orbital resonances. This dissertation explores the properties of two of the most populous inner main belt family groups --- the Flora family and the Nysa-Polana complex --- investigating their memberships, ages, spin properties, collision dynamics, and range in orbital and reflectance parameters. Though diffuse, the family associated with asteroid (8) Flora dominates the inner main belt in terms of the extent of its members in orbital parameter space, resulting in its significant overlap with multiple neighboring families. This dissertation introduces a new method for membership determination (the core sample method) which enables the distinction of the Flora family from the background, permitting its further analysis. The Flora family is shown to have a signature in plots of semimajor axis vs. size consistent with that expected for a collisional family dispersed as a result of the Yarkovsky radiation effect. The family's age is determined from the Yarkovsky dispersion to be 950 My. Furthermore, a survey of the spin sense of 21 Flora-region asteroids, accomplished via a time-efficient modification of the epoch method for spin sense determination, confirms the single-collision Yarkovsky-dispersed model for the family's origin. The neighboring Nysa-Polana complex is the likely source region for many of the carbonaceous near-Earth asteroids, several of which are important targets for spacecraft reconnaissance and sample return missions. Family identification in the Nysa-Polana complex via the core sample method reveals two families associated with asteroid (135) Hertha, both with distinct age and reflectance properties. The larger of these two families demonstrates a correlation in semimajor axis and eccentricity indicating that its family-forming collision occurred near the parent body's aphelion. In addition, the Eulalia family is connected with a possible second component, suggesting an anisotropic distribution of ejecta from its collision event.

Age specific serum anti-Müllerian hormone levels in 1,298 Korean women with regular menstruation

PubMed Central

Yoo, Ji Hee; Cha, Sun Wha; Park, Chan Woo; Yang, Kwang Moon; Song, In Ok; Koong, Mi Kyoung; Kang, Inn Soo

2011-01-01

Objective To determine the age specific serum anti-Müllerian hormone (AMH) reference values in Korean women with regular menstruation. Methods Between May, 2010 and January, 2011, the serum AMH levels were evaluated in a total of 1,298 women who have regular menstrual cycles aged between 20 and 50 years. Women were classified into 6 categories by age: 20-31 years, 32-34 years, 35-37 years, 38-40 years, 41-43 years, above 43 years. Measurement of serum AMH was measured by commercial enzyme-linked immunoassay. Results The serum AMH levels correlated negatively with age. The median AMH level of each age group was 4.20 ng/mL, 3.70 ng/mL, 2.60 ng/mL, 1.50 ng/mL, 1.30 ng/mL, and 0.60 ng/mL, respectively. The AMH values in the lower 5th percentile of each age group were 1.19 ng/mL, 0.60 ng/mL, 0.42 ng/mL, 0.27 ng/mL, 0.14 ng/mL, and 0.10 ng/mL, respectively. Conclusion This study determined reference values of serum AMH in Korean women with regular menstruation. These values can be applied to clinical evaluation and treatment of infertile women. PMID:22384425

Including Deposition Rate in Models of Cosmogenic Nuclide Accumulation in Fluvial Sediments to Improve Terrace Abandonment Ages

NASA Astrophysics Data System (ADS)

Norton, K. P.; Wang, N.; Van Dissen, R. J.; Little, T.

2017-12-01

Fluvial sediments are archives of the erosional, transport, and depositional processes occurring in the catchment. Terraces become robust markers for geomorphic analysis if their time of abandonment can be determined. Methods such as OSL can determine burial ages for fine grained sediments within the terrace fill but may not be directly related to the terrace abandonment age. Cosmogenic nuclides can be used to determine exposure ages for geologically young terraces but the surface being dated may have been subsequently eroded and the material itself may have been deposited with an inherited nuclide concentration. To deal with this problem, many researchers collect multiple samples with depth to model the depth-dependent nuclide concentration to help constrain inheritance and post-depositional erosion. It is often, however, assumed that the entire sediment pile accumulated instantaneously. In this submission, we present the results of a depth profile model that incorporates sediment accumulation rate to improve terrace age estimates. We test this model on fault-offset river terraces near Kaikoura, New Zealand. We measured depth profiles of OSL ages and cosmogenic nuclide concentrations of two late Quaternary terraces that are offset by up to 800 m across the Kekerengu Fault. OSL ages and dated tephras in the overlying loess provide minimum age constraints for both terraces while OSL ages of fine-grained sediments within the fill provide depositional ages. The predicted sedimentation rates for the terraces are as high as 0.5m/yr, consistent with geologically instantaneous deposition. Modelled abandonment ages from cosmogenic nuclides for the terraces are consistent with OSL and tephra constraints at 9.7 +/- 3.8 ka and 30.4 +/- 2.1 ka, respectively. These terrace abandonment ages yield dextral slip rates of 18.5-20.5 mm/yr and 25-28 mm/yr, respectively, consistent with the rapid slip rate on the adjacent Hope Fault.

Determinants of arterial stiffness in an apparently healthy population over 60 years.

PubMed

Alecu, C; Gueguen, R; Aubry, C; Salvi, P; Perret-Guillaume, C; Ducrocq, X; Vespignani, H; Benetos, A

2006-10-01

Arterial stiffness assessed by the pulse wave velocity (PWV), a non-invasive and reproducible method, predicts cardiovascular morbidity and mortality. The main determinants of arterial stiffness are well established in younger and middle-aged populations, but much less in the elderly. The aim of this study was to describe the determinants of arterial stiffness in elderly apparently healthy subjects. The study included 221 voluntary subjects born before 1944 (mean age 67.4+/-5.0 years), who had a standard health check-up at the 'Centre de Médecine Préventive' of Nancy. Arterial stiffness was evaluated by measuring the carotid-femoral PWV with the PulsePen automatic device. Clinical and biological parameters were evaluated at the same day. Measurements were valid and analysed in 207 subjects (94 women). Mean PWV was 9.39+/-2.64 m/s. Men showed higher PWV values than women (9.99+/-2.56 vs 8.66+/-2.56, P<0.001). In univariate analysis, PWV was correlated with age (r=0.26, P<0.001) and mean arterial pressure (MAP) (r=0.40, P<0.001), and these relationships were similar in men and women. Subjects with hypertension (P<0.001), diabetes mellitus (P<0.001) and obesity (P<0.01) had higher values of PWV. In multiple regression analysis, PWV correlated positively and independently with age, male gender, MAP and diabetes mellitus. In conclusion, in an apparently healthy elderly population, the main determinants of arterial stiffness are the age, MAP, diabetes and gender. Our study also shows that the gender-related differences in arterial stiffness observed in middle-aged subjects are maintained in the elderly.

Evaluation of Crack Arrest Toughness ( K IA) of P91 Steel in Various Cold Worked and Thermally Aged Conditions

NASA Astrophysics Data System (ADS)

Sathyanarayanan, S.; Moitra, A.; Sasikala, G.; Bhaduri, A. K.

2015-02-01

K IA is increasingly being regarded as a characteristic fracture toughness below which cleavage fracture does not occur. Its evaluation from small-sized Charpy specimens would be advantageous for applications in power plant industries. In this study, K IA has been evaluated for P91 steel in various cold worked and thermally aged conditions. Evaluation of K IA requires determination of crack arrest load( P arrest) and crack arrest length( a arrest). The main challenge is in the determination of a arrest due to the non-availability of standard methodologies and the absence of unequivocal microstructural signatures on the fracture surface in this steel to identify crack arrest. a arrest has been determined using the analytical Key- Curve methodology which has proven successful for this steel in unaged condition. The applicability of the Key- Curve method is validated by the good agreement of the determined final crack length with that measured optically on unbroken specimens of N&T and subsequently 15% cold-worked P91 steel which had been previously aged at 650 °C for 5000 h. Mean K IA varies from 47.46 MPa√m (NT steel aged at 600 °C for 5000 h) to 69.85 MPa√m(NT + 15% cw steel aged at 650 °C for 10000 h) for the various cold worked and aged datasets. K IA is found to be an average property unlike initiation toughness ( K Jd) which shows statistical scatter. Mean K IA is found to be in reasonable agreement with the lower bound values of cleavage initiation toughness ( K Jd) for the datasets in this study.

Blank corrections for ramped pyrolysis radiocarbon dating of sedimentary and soil organic carbon.

PubMed

Fernandez, Alvaro; Santos, Guaciara M; Williams, Elizabeth K; Pendergraft, Matthew A; Vetter, Lael; Rosenheim, Brad E

2014-12-16

Ramped pyrolysis (RP) targets distinct components of soil and sedimentary organic carbon based on their thermochemical stabilities and allows the determination of the full spectrum of radiocarbon ((14)C) ages present in a soil or sediment sample. Extending the method into realms where more precise ages are needed or where smaller samples need to be measured involves better understanding of the blank contamination associated with the method. Here, we use a compiled data set of RP measurements of samples of known age to evaluate the mass of the carbon blank and its associated (14)C signature, and to assess the performance of the RP system. We estimate blank contamination during RP using two methods, the modern-dead and the isotope dilution method. Our results indicate that during one complete RP run samples are contaminated by 8.8 ± 4.4 μg (time-dependent) of modern carbon (MC, fM ∼ 1) and 4.1 ± 5.5 μg (time-independent) of dead carbon (DC, fM ∼ 0). We find that the modern-dead method provides more accurate estimates of uncertainties in blank contamination; therefore, the isotope dilution method should be used with caution when the variability of the blank is high. Additionally, we show that RP can routinely produce accurate (14)C dates with precisions ∼100 (14)C years for materials deposited in the last 10,000 years and ∼300 (14)C years for carbon with (14)C ages of up to 20,000 years.

A Psychometric Study of the Bayley Scales of Infant and Toddler Development in Persian Language Children.

PubMed

Azari, Nadia; Soleimani, Farin; Vameghi, Roshanak; Sajedi, Firoozeh; Shahshahani, Soheila; Karimi, Hossein; Kraskian, Adis; Shahrokhi, Amin; Teymouri, Robab; Gharib, Masoud

2017-01-01

Bayley Scales of infant & toddler development is a well-known diagnostic developmental assessment tool for children aged 1-42 months. Our aim was investigating the validity & reliability of this scale in Persian speaking children. The method was descriptive-analytic. Translation- back translation and cultural adaptation was done. Content & face validity of translated scale was determined by experts' opinions. Overall, 403 children aged 1 to 42 months were recruited from health centers of Tehran, during years of 2013-2014 for developmental assessment in cognitive, communicative (receptive & expressive) and motor (fine & gross) domains. Reliability of scale was calculated through three methods; internal consistency using Cronbach's alpha coefficient, test-retest and interrater methods. Construct validity was calculated using factor analysis and comparison of the mean scores methods. Cultural and linguistic changes were made in items of all domains especially on communication subscale. Content and face validity of the test were approved by experts' opinions. Cronbach's alpha coefficient was above 0.74 in all domains. Pearson correlation coefficient in various domains, were ≥ 0.982 in test retest method, and ≥0.993 in inter-rater method. Construct validity of the test was approved by factor analysis. Moreover, the mean scores for the different age groups were compared and statistically significant differences were observed between mean scores of different age groups, that confirms validity of the test. The Bayley Scales of Infant and Toddler Development is a valid and reliable tool for child developmental assessment in Persian language children.

Solar flare neon and solar cosmic ray fluxes in the past using gas-rich meteorites

NASA Technical Reports Server (NTRS)

Nautiyal, C. M.; Rao, M. N.

1986-01-01

Methods were developed earlier to deduce the composition of solar flare neon and to determine the solar cosmic ray proton fluxes in the past using etched lunar samples and at present, these techniques are extended to gas rich meteorites. By considering high temperature Ne data points for Pantar, Fayetteville and other gas rich meteorites and by applying the three component Ne-decomposition methods, the solar cosmic ray and galactic cosmic ray produced spallation Ne components from the trapped SF-Ne was resolved. Using appropiate SCR and GCR production rates, in the case of Pantar, for example, a GCR exposure age of 2 m.y. was estimated for Pantar-Dark while Pantar-Light yielded a GCR age of approx. 3 m.y. However the SCR exposure age of Pantar-Dark is two orders of magnitude higher than the average surface exposure ages of lunar soils. The possibility of higher proton fluxes in the past is discussed.

Parental Predictors of Children’s Shame and Guilt at Age 6 in a Multi-Method, Longitudinal Study

PubMed Central

Parisette-Sparks, Alyssa; Bufferd, Sara J.; Klein, Daniel N.

2015-01-01

Objective Shame and guilt are self-conscious emotions that begin to develop early in life and are associated with various forms of psychopathology. However, little is known about the factors that contribute to these emotions in young children. Specifically, no longitudinal studies to date have examined a range of parent factors that shape the expression of children’s shame and guilt. The current multi-method, longitudinal study sought to determine whether parenting style, parental psychopathology, and parents’ marital satisfaction assessed when children were age 3 predict expressions of shame and guilt in children at age 6. Method A large community sample of families (N = 446; 87.4% Caucasian) with three-year-old children (45.7% female) was recruited through commercial mailing lists. Parent variables were assessed when children were age 3 with mother- and father-report questionnaires and a diagnostic interview. Children’s expressions of shame and guilt were observed in the laboratory at age 6. Results Fathers’, but not mothers’, history of depression and permissive parenting assessed when children were age 3 predicted children’s expressions of shame and guilt when children were age 6; parents’ marital dissatisfaction also predicted children’s shame and guilt. Conclusions These findings suggest that parents, and fathers in particular, contribute to expressions of self-conscious emotions in children. These data on emotional development may be useful for better characterizing the risk and developmental pathways of psychopathology. PMID:26538055

Completed suicide in adults of rural Kerala: rates and determinants.

PubMed

Sauvaget, C; Ramadas, K; Fayette, J M; Thomas, G; Thara, S; Sankaranarayanan, R

2009-01-01

India has witnessed a dramatic increase in suicide rates during the past few decades. The southern state of Kerala has been reporting the highest rates of suicide. Since suicide rates are estimated from death registries, they are likely to be under-reported because the civil registration system is incomplete and suicide deaths are poorly reported. A cohort of 132 000 participants (age 35 years and above) in Thiruvananthapuram (erstwhile Trivandrum) district, Kerala was followed up for mortality from 1996 to 2005, after having filled-in a lifestyle questionnaire at baseline. The cause of death was based on verbal autopsy. Suicide methods were recorded and rates were estimated, and suicide risks were calculated according to several socioeconomic factors. During the follow up period, a total of 11 608 deaths, of which 385 were suicides (3.3% of total deaths), were registered. The overall suicide rate was 39.3/100 000 person-years among adults 35-90 years of age (men: 78/ 100000; women: 16.5/100000). The predominant methods of suicide were hanging, followed by poisoning and drowning. The suicide determinants were male gender, middle-age (40-60 years), Hindu, alcohol drinkers and secondary education level (< or = 7 years). Neither low socioeconomic level, living alone, nor being a married woman was associated with suicide risk. Suicide rates were consistent with the official rates of Thiruvananthapuram district (37/100 000). However, our study population did not include the 14-34-year-old age-group which represents more than 37% of all suicides and hence it is more likely that the official rates are under-reported. Determinants of suicide were in line with previous studies.

Effect of age and anticonvulsants on seizure threshold during bilateral electroconvulsive therapy with brief-pulse stimulus: A chart-based analysis

PubMed Central

Nitturkar, Abhishek R.; Sinha, Preeti; Bagewadi, Virupakshappa I.; Thirthalli, Jagadisha

2016-01-01

Background: Efficacy and adverse effects of electroconvulsive therapy (ECT) depend on the extent to which the electrical stimulus exceeds patients' seizure thresholds (STs). Titration method of estimating ST is recommended. Age and co-prescribed anticonvulsants (ACs) are known to affect ST. Literature on ST in bilateral ECT (BLECT) is sparse. Objective: To explore the clinical and demographic determinants of ST in a clinically representative sample of patients prescribed with BLECT. Materials and Methods: ECT records of 640 patients who received BLECT in 2011 in an academic psychiatric setting were studied. Demographic, clinical, pharmacological, and ECT details were analyzed. As per the standard practice, during the 1st ECT session, ST was determined by titration method, starting with 30 milli-Coulombs (mC) and increasing by 30 mC and thence in steps of 60 mC. Increase in ST over up to 6th session of ECT was noted. Receiver operating characteristic curve was used to find age cut-off with high specificity for ST ≥120 mC. The associations of ST and increase in ST with the age cut-off and other clinical factors were assessed using Chi-square test and logistic regression analysis. Results: The mean age was 30.98 years (+11.23 years) and mean ST at 1st ECT session was 130.36 mC (+51.96 mC). There was significantly high positive correlation (r = 0.37, P < 0.001) between age and ST. Cut-off age of 45 years had high specificity: Only 4.6% of those older than 45 years had ST <120 mC. Higher proportion of patients on AC had ST ≥120 mC. These associations were seen even after controlling for potential confounds of each other using logistic regression analysis. The results were similar for increase in ST over the course of ECT. Sex, diagnosis, use of antipsychotics, antidepressants, lithium, and benzodiazepines (BZPs) had no effect on ST or its increase. Conclusions: For BLECT using brief-pulse stimulus, ST depends on age and use of AC. For patients above the age of 45 years, ST estimation may be started at 120 mC with least risk of using unduly higher stimulus. Other medications including BZPs have little influence on ST. PMID:27385853

Effects of a Low Advanced Glycation End Products Diet on Insulin Levels: The Feasibility of a Crossover Comparison Test.

PubMed

Sukino, Shin; Nirengi, Shinsuke; Kawaguchi, Yaeko; Kotani, Kazuhiko; Tsuzaki, Kokoro; Okada, Hiroshi; Suganuma, Akiko; Sakane, Naoki

2018-05-01

Advanced glycation end products (AGEs) are associated with diabetes mellitus. Digested food-derived AGEs have been implicated in the pathogenesis of AGE-related disorders, and restricting diet-derived AGEs improves insulin resistance in animal models. The AGE content in foods changes according to cooking method, and it is higher in baked or oven-fried foods than in those prepared by steaming or simmering. Here, we examined the feasibility of crossover comparison tests for determining how different cooking methods (normal diet vs. low-AGE diet) affect insulin levels in non-diabetic Japanese subjects. Five adult men and women (age, 41 ± 7 years; body mass index (BMI), 21.7 ± 2.6 kg/m 2 ) were enrolled. The following dietary regimen was used: days 1 - 3, control meal; day 4, test meal (normal diet vs. low-AGE diet); day 5, washout day; and day 6, test meal. On days 4 and 6, blood samples were collected before and at 2, 4, and 6 h after meals. Blood levels of N-(carboxymethyl) lysine (CML) increased with dietary intake, but the increase was similar for the normal diet and low-AGE diet groups. Mean plasma glucose, insulin, triglycerides (TG), and CML did not differ significantly between the two groups. The area under the curve (AUC) for insulin levels was lower in the low-AGE diet group (d = 0.8). The sample size calculated from the effect size of the insulin AUC change was 22. Twenty-two subjects may be needed to investigate the changes in clinical parameters attributable to cooking method in non-diabetic Japanese subjects.

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

PubMed Central

Kasat, Vikrant; Karjodkar, FR; Vaz, Walter

2010-01-01

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 D1, D2, 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 D2, 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. PMID:21731347

[METHOD FOR DETERMINING EROSIVE LESIONS OF THE GASTRIC MUCOUSA IN CHILDREN WITH JUVENILE ARTHRITIS].

PubMed

Listopadova, A P; Novikova, V P; Melnikova, I U; Petrovskiy, A N; Slizovskiy, N V

2015-01-01

To detect the clinical diagnostic criteria for non-invasive diagnosis of erosive gastritis in children with juvenile arthritis have been studied the 92 children aged 9 to 16 years (mean age-13,9 ± 2,3 years) with verified diagnosis of juvenile arthritis, of whom 10 had erosive gastritis (group 1) and 82 without erosions (group 2). A comparison of the groups on 23 grounds by analysis of contingency tables and the subsequent discriminant analysis, has developed a new non-invasive method for determining the erosive lesions of the mucous membrane of the stomach in children with juvenile arthritis, including a score of history, complaints and the results of laboratory studies the level of the G-17, pepsinogen I, pepsinogen II, and the ratio of pepsinogen I to pepsinogen II, the presence of autoantibodies to the H+, K+/ATPase of the parietal cells of the stomach, the test for occult blood "Colon View Hb and Hb/Hp". Developed a diagnostic table, including 11 features with scores each. The total score 27 or higher allows a high degree of probability to determine the erosive lesions of the gastric mucosa in children with juvenile arthritis.

Construction ages of the Upton Stone Chamber: Preliminary findings and suggestions for future luminescence research

USGS Publications Warehouse

Mahan, Shannon; Martin, Frederick; Taylor, Cathy

2015-01-01

The Upton Chamber in Massachusetts, an earth-covered stone structure 3.4 meters (m) in diameter, with a corbelled stone dome, and a 4.3 m long entrance passageway, is studied with the aim of determining whether optically stimulated luminescence (OSL) dating methods can be used to establish the approximate construction date of the entranceway. Three samples, taken from soil behind the lowest stones in the wall of the entrance passageway, returned OSL ages between 385 and 660 years ago (or from 1625 A.D. to 1350 A.D.; using the year 2011 as the 0 year). One sample, taken below the bottom of the artifact layers in an archeological test pit in front of the chamber entrance, returned OSL ages between 650 and 880 years ago. A modern sample collected from a nearby fluvial channel returned an age between 55 and 175 years. The Upton Chamber OSL sampling results are challenging to interpret because there are mixtures in the samples of both younger and older grains that likely result from human modification, root or soil processes, animal bioturbation (i.e. ants and worms), and/or partial bleaching. The ages were determined using the lowest component of the finite mixture model as applied to a distribution of quartz grains. Further research may enable us to determine whether older components are of anthropomorphic or geological origin.

Intra-individual variation in urinary iodine concentration: effect of statistical correction on population distribution using seasonal three-consecutive-day spot urine in children

PubMed Central

Ji, Xiaohong; Liu, Peng; Sun, Zhenqi; Su, Xiaohui; Wang, Wei; Gao, Yanhui; Sun, Dianjun

2016-01-01

Objective To determine the effect of statistical correction for intra-individual variation on estimated urinary iodine concentration (UIC) by sampling on 3 consecutive days in four seasons in children. Setting School-aged children from urban and rural primary schools in Harbin, Heilongjiang, China. Participants 748 and 640 children aged 8–11 years were recruited from urban and rural schools, respectively, in Harbin. Primary and secondary outcome measures The spot urine samples were collected once a day for 3 consecutive days in each season over 1 year. The UIC of the first day was corrected by two statistical correction methods: the average correction method (average of days 1, 2; average of days 1, 2 and 3) and the variance correction method (UIC of day 1 corrected by two replicates and by three replicates). The variance correction method determined the SD between subjects (Sb) and within subjects (Sw), and calculated the correction coefficient (Fi), Fi=Sb/(Sb+Sw/di), where di was the number of observations. The UIC of day 1 was then corrected using the following equation: Results The variance correction methods showed the overall Fi was 0.742 for 2 days’ correction and 0.829 for 3 days’ correction; the values for the seasons spring, summer, autumn and winter were 0.730, 0.684, 0.706 and 0.703 for 2 days’ correction and 0.809, 0.742, 0.796 and 0.804 for 3 days’ correction, respectively. After removal of the individual effect, the correlation coefficient between consecutive days was 0.224, and between non-consecutive days 0.050. Conclusions The variance correction method is effective for correcting intra-individual variation in estimated UIC following sampling on 3 consecutive days in four seasons in children. The method varies little between ages, sexes and urban or rural setting, but does vary between seasons. PMID:26920442

A new method for the visualization and quantification of internal skin elasticity by ultrasound imaging.

PubMed

Osanai, Osamu; Ohtsuka, Mayumi; Hotta, Mitsuyuki; Kitaharai, Takashi; Takema, Yoshinori

2011-08-01

Skin elasticity has been assessed previously only in the surface layer. We developed a new method that uses tissue strain imaging (TSI) technology, and the aim of this study was to test this new method to assess internal skin elasticity. Using a pressure device with a 12 MHz ultrasound transducer, constant and linear compressions were applied to the cheek skin of 35 volunteers (aged: 20-60 years). The elasticity of each layer (dermis, subcutaneous and muscle) was measured and analyzed using the TSI application software incorporated into the Toshiba Aplio(™) XV ultrasound system. A skin tissue-equivalent phantom, which is a block of material with the acoustic velocity (1530 m/s) of human skin, was collaboratively developed by OST Inc. This phantom was placed between the skin and the transducer as a reference material. Skin elasticity was clearly visualized and quantified in each layer of the skin. Age-dependent decreases in elasticity were determined in all layers of the skin. Among the three internal skin layers, the highest elasticity was determined in the subcutaneous layer followed by the muscle layer. These findings support the validity and sensitivity of the TSI method to assess the elasticity of various layers of skin. © 2011 John Wiley & Sons A/S.

Correction for the Hematocrit Bias in Dried Blood Spot Analysis Using a Nondestructive, Single-Wavelength Reflectance-Based Hematocrit Prediction Method.

PubMed

Capiau, Sara; Wilk, Leah S; De Kesel, Pieter M M; Aalders, Maurice C G; Stove, Christophe P

2018-02-06

The hematocrit (Hct) effect is one of the most important hurdles currently preventing more widespread implementation of quantitative dried blood spot (DBS) analysis in a routine context. Indeed, the Hct may affect both the accuracy of DBS methods as well as the interpretation of DBS-based results. We previously developed a method to determine the Hct of a DBS based on its hemoglobin content using noncontact diffuse reflectance spectroscopy. Despite the ease with which the analysis can be performed (i.e., mere scanning of the DBS) and the good results that were obtained, the method did require a complicated algorithm to derive the total hemoglobin content from the DBS's reflectance spectrum. As the total hemoglobin was calculated as the sum of oxyhemoglobin, methemoglobin, and hemichrome, the three main hemoglobin derivatives formed in DBS upon aging, the reflectance spectrum needed to be unmixed to determine the quantity of each of these derivatives. We now simplified the method by only using the reflectance at a single wavelength, located at a quasi-isosbestic point in the reflectance curve. At this wavelength, assuming 1-to-1 stoichiometry of the aging reaction, the reflectance is insensitive to the hemoglobin degradation and only scales with the total amount of hemoglobin and, hence, the Hct. This simplified method was successfully validated. At each quality control level as well as at the limits of quantitation (i.e., 0.20 and 0.67) bias, intra- and interday imprecision were within 10%. Method reproducibility was excellent based on incurred sample reanalysis and surpassed the reproducibility of the original method. Furthermore, the influence of the volume spotted, the measurement location within the spot, as well as storage time and temperature were evaluated, showing no relevant impact of these parameters. Application to 233 patient samples revealed a good correlation between the Hct determined on whole blood and the predicted Hct determined on venous DBS. The bias obtained with Bland and Altman analysis was -0.015 and the limits of agreement were -0.061 and 0.031, indicating that the simplified, noncontact Hct prediction method even outperforms the original method. In addition, using caffeine as a model compound, it was demonstrated that this simplified Hct prediction method can effectively be used to implement a Hct-dependent correction factor to DBS-based results to alleviate the Hct bias.

Tooth coronal index and pulp/tooth ratio in dental age estimation on digital panoramic radiographs-A comparative study.

PubMed

Jain, Supreet; Nagi, Ravleen; Daga, Minal; Shandilya, Ashutosh; Shukla, Aastha; Parakh, Abhinav; Laheji, Afshan; Singh, Rahul

2017-08-01

Assessment of an age of an individual whether living or dead through teeth is one of the most reliable and simple method to calculate age than skeletal remains especially when they are in poor conditions. The study was carried out with aim of (i) to evaluate reliability of dental age assessment through two different methods for adults i.e. tooth coronal index and pulp/tooth ratio using digital panoramic radiographs and (ii) to compare these methods for their accuracy in age determination. The digital panoramic radiographs of 180 subjects of Chhattisgarh aged 15-70 years were selected for the study. The measurements were performed on the JPEG images of selected panoramic radiographs by using Adobe Acrobat 7.0 professional software. For tooth coronal index (TCI), height of the crown i.e. coronal height (CH) and the height of the coronal pulp cavity i.e. coronal pulp cavity height (CPCH) of mandibular second premolars and first molars was measured in millimeter (mm) and then TCI was calculated for each tooth and calculated age was compared with chronological age. For pulp/tooth ratio, the measurements of pulp chamber height (PCH) and crown root trunk height (CRTH) were performed on the mandibular first and second molar teeth, the pulp chamber crown root trunk height ratios (PCTHR) of selected tooth were calculated. The acquired data were subjected to Pearson correlation test, unpaired t test and Analysis of Variance (ANOVA) analysis. Results suggested that TCI (mandibular first molar r=-0.178), second premolar (r=-0.187) and PCTHR(mandibular first molar r=-0.921, second molar r=-0.901) correlated negatively with chronological age suggesting decrease in size of pulp cavity. Mandibular first molar was found to be most reliable tooth to estimate dental age. The study showed that both PCTHR and TCI have negative association with chronological age. PCTHR showed slightly higher negative correlation and proved as a better tool for age estimation than TCI. Statistically significant differences were observed between chronological and calculated age by both methods thus emphasizing the need for future clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

[Construction of a physiological aging scale for healthy people based on a modified Delphi method].

PubMed

Long, Yao; Zhou, Xuan; Deng, Pengfei; Liao, Xiong; Wu, Lei; Zhou, Jianming; Huang, Helang

2016-04-01

To build a physiological aging scale for healthy people.
 We collected age-related physiologic items through literature screening and expert interview. Two rounds of Delphi were implemented. The importance, feasibility and the degree of authority for the physiological index system were graded. Using analytic hierarchy process, we determined the weight of dimensions and items.
 Using Delphy mothod, 17 physiological and other professional experts offered the results as follow: coefficient of expert authorities Cr was 0.86±0.03, coordination coefficients for the first and second round were 0.264(χ2=229.691, P<0.001) and 0.293(χ2=228.474，P<0.001), respectively. The consistency was good. The aging scale for healthy people included 3 dimensions, namely physical form, feeling movement and functional status. Each dimension had 8 items. The weight coefficients for the 3 dimensions were 0.54, 0.16, and 0.30, respectively. The Cronbach's α coefficient of the scale was 0.893, the reliability was 0.796, and the variance of the common factor was 58.17%.
 The improved Delphi method or physiological aging scale is satisfied, which can provide reference for the evaluation of aging.

Urinary tract infection in febrile under five children in Enugu, South Eastern Nigeria.

PubMed

Ibeneme, C A; Oguonu, T; Okafor, H U; Ikefuna, A N; Ozumba, U C

2014-01-01

Fever is a common symptom of urinary tract infection (UTI) in children less than 5 years of age. Little attention is however paid to UTI as a cause of fever in this age group. The objective of the following study is to determine the prevalence of UTI in febrile children less than 5 years of age and relate it to demographic and clinical characteristics. Urine specimen of febrile children aged 1-59 months obtained by suprapubic or midstream methods were analyzed using standard laboratory methods of microscopy, culture and sensitivity. A total of 200 children were enrolled; nearly 56% (112/200) were males. The mean age of the subjects was 31.14 ± 17.96 months. The prevalence of UTI was 11% and was significantly higher in females than in males ( P = 0.049). Children below 12 months of age had a higher rate of UTI than those 12 months and above ( P = 0.028). The common clinical features were vomiting, abdominal pain, diarrhea, urinary frequency and urgency but none had a significant association with UTI. UTI is common in febrile under-fives especially among females and infants. No association was apparent between the occurrence of UTI and clinical parameters.

U-Th-Pb systematics in three Apollo 14 basalts and the problem of initial Pb in lunar rocks.

NASA Technical Reports Server (NTRS)

Tera, F.; Wasserburg, G. J.

1972-01-01

The isotopic composition of Pb and the elemental concentration of U, Th and Pb were measured on 'total' rock samples 14053, 14073 and 14310 and on mineral separates of 14310 and 14053. These are the first Pb-U isochrons obtained for lunar basalts and indicate a reasonable solution to the previous discrepancy between the different methods of 'absolute' age determination. The resulting U-Pb isochron ages are compatible with the Rb-Sr and K-Ar ages on the same rocks. However, it is not possible to establish a precise time of 'crystallization' from the Pb-U data because of the small angle of intersection between the linear arrays and the concordia curve. These data show that total rock model ages do not in general yield crystallization ages. The data on 14310 and 14053 show that these rocks were formed containing a highly radiogenic initial lead which accounts for the excessively high total rock model ages by the U-Th-Pb method. The data prove that at the time of extrusion of some basalts, unsupported lead with extremely high Pb-207/Pb-206 ratios was added to the lunar surface.

Is Greulich and Pyle atlas still a good reference for bone age assessment?

NASA Astrophysics Data System (ADS)

Zhang, Aifeng; Tsao, Sinchai; Sayre, James W.; Gertych, Arkadiusz; Liu, Brent J.; Huang, H. K.

2007-03-01

The most commonly used method for bone age assessment in clinical practice is the book atlas matching method developed by Greulich and Pyle in the 1950s. Due to changes in both population diversity and nutrition in the United States, this atlas may no longer be a good reference. An updated data set becomes crucial to improve the bone age assessment process. Therefore, a digital hand atlas was built with 1,100 children hand images, along with patient information and radiologists' readings, of normal Caucasian (CAU), African American (BLK), Hispanic (HIS), and Asian (ASI) males (M) and females (F) with ages ranging from 0 - 18 years. This data was collected from Childrens' Hospital Los Angeles. A computer-aided-diagnosis (CAD) method has been developed based on features extracted from phalangeal regions of interest (ROIs) and carpal bone ROIs from this digital hand atlas. Using the data collected along with the Greulich and Pyle Atlas-based readings and CAD results, this paper addresses this question: "Do different ethnicities and gender have different bone growth patterns?" To help with data analysis, a novel web-based visualization tool was developed to demonstrate bone growth diversity amongst differing gender and ethnic groups using data collected from the Digital Atlas. The application effectively demonstrates a discrepancy of bone growth pattern amongst different populations based on race and gender. It also has the capability of helping a radiologist determine the normality of skeletal development of a particular patient by visualizing his or her chronological age, radiologist reading, and CAD assessed bone age relative to the accuracy of the P&G method.

The Resolved Stellar Population in 50 Regions of M83 from HST/WFC3 Early Release Science Observations

NASA Technical Reports Server (NTRS)

Kim, Hwihyun; Whitmore, Bradley C.; Chandar, Rupali; Saha, Abhijit; Kaleida, Catherine C.; Mutchler, Max; Cohen, Seth H.; Calzetti, Daniela; O’Connell, Robert W.; Windhorst, Rogier A.;

Bias of apparent tracer ages in heterogeneous environments.

PubMed

McCallum, James L; Cook, Peter G; Simmons, Craig T; Werner, Adrian D

2014-01-01

The interpretation of apparent ages often assumes that a water sample is composed of a single age. In heterogeneous aquifers, apparent ages estimated with environmental tracer methods do not reflect mean water ages because of the mixing of waters from many flow paths with different ages. This is due to nonlinear variations in atmospheric concentrations of the tracer with time resulting in biases of mixed concentrations used to determine apparent ages. The bias of these methods is rarely reported and has not been systematically evaluated in heterogeneous settings. We simulate residence time distributions (RTDs) and environmental tracers CFCs, SF6 , (85) Kr, and (39) Ar in synthetic heterogeneous confined aquifers and compare apparent ages to mean ages. Heterogeneity was simulated as both K-field variance (σ(2) ) and structure. We demonstrate that an increase in heterogeneity (increase in σ(2) or structure) results in an increase in the width of the RTD. In low heterogeneity cases, widths were generally on the order of 10 years and biases generally less than 10%. In high heterogeneity cases, widths can reach 100 s of years and biases can reach up to 100%. In cases where the temporal variations of atmospheric concentration of individual tracers vary, different patterns of bias are observed for the same mean age. We show that CFC-12 and CFC-113 ages may be used to correct for the mean age if analytical errors are small. © 2013, National Ground Water Association.

Determinants of Modern Contraceptive Uptake among Nigerian Women: Evidence from the National Demographic and Health Survey.

PubMed

Johnson, Ofonime E

2017-09-01

Family planning is a key strategy in the control of fertility among women. This study sought to determine various factors that influence modern family planning use in Nigeria. The study used data from Nigeria Demographic and Health Survey (NDHS) 2013. Analysis was carried out using Stata version 12.1. Multivariate logistic regression was used to determine association between various factors and use of modern family planning methods. A total of 119,386 women aged 15-49 years participated in the study. The mean age of respondents was 35.9 ± 8.1 years. Overall, contraceptive prevalence rate of modern methods was 10.3%. The highest proportion of use was 26.7% in the South West, while the lowest was 2.7% in the North West. Predictors of modern family planning use were higher education (OR=4.49, 95% CI: 4.10-4.92), richest wealth quintile (OR=3.71 CI: 3.29-4.19), being from South West (OR=3.42, 95% CI: 3.15-3.70), age 25-49 years (OR=1.55, 95% CI: 1.42-1.69) and urban residence (OR=1.08, 95% CI: 1.03-1.13) (p <0.001). The highest predictors of modern contraceptive use were education and wealth index. These indices were poorest in North Western Nigeria. Measures should be taken to improve female literacy and employment as these will most likely improve uptake of modern contraceptives among women in Nigeria.

Hematologic reference intervals and age effect in European Strigiformes.

PubMed

Agusti Montolio, Susana; Molina López, Rafael; Cray, Carolyn; Lavín González, Santiago; Nicolás Francisco, Olga; Marco Sánchez, Ignasi; Casas-Díaz, Encarna; Cuenca Valera, Rafaela

2017-09-01

The clinical importance of hematologic testing in avian veterinary medicine is reflected in the increasing number of studies for the establishment of hematologic RIs of Strigiformes and other species. Age is an important physiologic factor in birds and the effect on hematology variable should be understood. The objective of this study was to determine baseline data of hematologic variables in 5 species of Iberian Strigiformes in different age classes. Nocturnal birds of prey were sampled at Wildlife Health Centers. Packed cell volume was determined by the microhematocrit centrifugation method, and RBC and WBC counts were determined using the direct hemocytometer count method with Natt and Herrick solution. Hemoglobin concentration was measured spectrophotometrically. The MCV, MCHC, and MHC were calculated using the standard formulas. The differential WBC count was performed by the routine microscopic evaluation of 200 cells on a blood smear manually stained with Wright stain. Thrombocyte blood count estimate was obtained from the blood film. No differences were observed between juveniles and adults for any variable evaluated in Tawny owl, Little owl, Scops owl, Long-eared owl, and Barn owl. In addition, PCV, RBC, and HGB of chicks were statistically significantly lower than in juveniles and adults, and total WBC was significantly higher in Tawny owl, Little owl, Scops owl, and Long-eared owl. Our findings provide evidence that laboratory data from chicks of Strigiformes are different compared to juveniles and adults; therefore, separate RIs were defined. © 2017 American Society for Veterinary Clinical Pathology.

Association of Frontline Worker-Provided Services with Change in Block-Level Complementary Feeding Indicators: An Ecological Analysis from Bihar, India

PubMed Central

Das, Aritra; Mahapatra, Sanchita; Sai Mala, Guntur; Chaudhuri, Indrajit; Mahapatra, Tanmay

2016-01-01

Background Insufficiencies in complementary feeding put infants and young children at increased risk of undernutrition. Till now, most Indian studies have looked at the individual level determinants of complementary feeding practices. We aimed to evaluate the association of frontline worker (FLW) provided nutritional counselling services, with change in community level indicators of complementary feeding practices among 9–11 month old children over time. Methods The study data was obtained from five rounds of ‘Lot Quality Assurance Sampling’ survey in eight districts of Bihar, an impoverished Indian state. The surveys were conducted as evaluation exercises for the ‘Integrated Family Health Initiative (IFHI)’–a multi-faceted program aimed at improving the maternal and child health outcomes in Bihar. The main outcome indicators were—current breastfeeding, age-appropriate minimum frequency of semi-solid food, age-appropriate minimum quantity of semi-solid food, initiation of complementary feeding at the right age, and dietary diversity. Repeated measures analysis was performed to determine the association of changes in the outcome indicators with coverage of FLW-provided counselling services. Results Visits by FLW, advices on age-appropriate frequency and handwashing were significant predictors of receiving age-appropriate frequency of feeding. The determinants of receiving age-appropriate quantity were—advices on age appropriate frequency and advices on handwashing. Receiving food support from AWC and FLW visits were significantly associated with initiating complementary feeding at the right age. Conclusions The present study identified the critical elements among the different types of FLW-provided services. The study findings, from an economically and socially underdeveloped region of India, would inform the relevant programs about the nutritional counselling services that need to be emphasized upon for reducing the burden of childhood malnutrition. PMID:27832211

An objective method to determine the probability distribution of the minimum apparent age of a sample of radio-isotopic dates

NASA Astrophysics Data System (ADS)

Ickert, R. B.; Mundil, R.

2012-12-01

Dateable minerals (especially zircon U-Pb) that crystallized at high temperatures but have been redeposited, pose both unique opportunities and challenges for geochronology. Although they have the potential to provide useful information on the depositional age of their host rocks, their relationship to the host is not always well constrained. For example, primary volcanic deposits will often have a lag time (time between eruption and deposition) that is smaller than can be resolved using radiometric techniques, and the age of eruption and of deposition will be coincident within uncertainty. Alternatively, ordinary clastic sedimentary rocks will usually have a long and variable lag time, even for the youngest minerals. Intermediate cases, for example moderately reworked volcanogenic material, will have a short, but unknown lag time. A compounding problem with U-Pb zircon is that the residence time of crystals in their host magma chamber (time between crystallization and eruption) can be high and is variable, even within the products of a single eruption. In cases where the lag and/or residence time suspected to be large relative to the precision of the date, a common objective is to determine the minimum age of a sample of dates, in order to constrain the maximum age of the deposition of the host rock. However, both the extraction of that age as well as assignment of a meaningful uncertainty is not straightforward. A number of ad hoc techniques have been employed in the literature, which may be appropriate for particular data sets or specific problems, but may yield biased or misleading results. Ludwig (2012) has developed an objective, statistically justified method for the determination of the distribution of the minimum age, but it has not been widely adopted. Here we extend this algorithm with a bootstrap (which can show the effect - if any - of the sampling distribution itself). This method has a number of desirable characteristics: It can incorporate all data points while being resistant to outliers, it utilizes the measurement uncertainties, and it does not require the assumption that any given cluster of data represents a single geological event. In brief, the technique generates a synthetic distribution from the input data by resampling with replacement (a bootstrap). Each resample is a random selection from a Gaussian distribution defined by the mean and uncertainty of the data point. For this distribution, the minimum value is calculated. This procedure is repeated many times (>1000) and a distribution of minimum values is generated, from which a confidence interval can be constructed. We demonstrate the application of this technique using natural and synthetic datasets, show the advantages and limitations, and relate it to other methods. We emphasize that this estimate remains strictly a minimum age - as with any other estimate that does not explicitly incorporate lag or residence time, it will not reflect a depositional age if the lag/residence time is larger than the uncertainty of the estimate. We recommend that this or similar techniques be considered by geochronologists. Ludwig, K.R., 2012. Isoplot 3.75, A geochronological toolkit for Microsoft Excel; Berkeley Geochronology Center Special Publication no. 5

Age- and sex-specific reference values for fasting serum insulin levels and insulin resistance/sensitivity indices in healthy Iranian adults: Tehran Lipid and Glucose Study.

PubMed

Tohidi, Maryam; Ghasemi, Asghar; Hadaegh, Farzad; Derakhshan, Arash; Chary, Abdolreza; Azizi, Fereidoun

2014-04-01

Increased insulin concentration is a surrogate for insulin resistance and early assessment of fasting insulin may help in identifying those who are potentially at high risk of type 2 diabetes, hypertension, and cardiovascular disease. The aim of this study was to determine age- and sex-related reference values for serum insulin and insulin resistance/sensitivity indices in Iranian subjects. Serum insulin levels were measured by electrochemiluminescence immunoassay in 5786 participants of the Tehran Lipid and Glucose Study. After application of exclusion criteria, 309 non-obese healthy subjects (124 men and 185 women), aged 24-83 y, were included. The International Federation of Clinical Chemistry guidelines (non-parametric method) and the robust method were used for determining reference values. Overall 95% reference values for fasting insulin were 1.61-11.37, 2.34-11.98, and 2.11-12.49 μU/mL in men, women, and total population respectively. Mean fasting insulin concentration showed a decreasing trend with age in both genders (p for trend ≤0.001). Age, waist circumference, and systolic blood pressures were biological determinants of fasting insulin in both genders; in addition, insulin was modulated by triglycerides in men and fasting glucose in women. Reference intervals for HOMA1-IR, HOMA2-IR, and QUICKI were 0.63-2.68, 0.40-1.80, and 0.33-0.42, respectively. This study presents the first set of reference values for fasting serum insulin to be 2-12 μU/mL for both genders in a healthy sample of Iranian adults along with the reference values for insulin resistance/sensitivity indices. These values could be used for identifying subjects with insulin resistance in epidemiological and clinical research. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Comparison of data from the rostock cornea module of the heidelberg retina tomograph, the oculus pentacam, and the endothelial cell microscope.

PubMed

Rieth, Sven; Engel, Felix; Bühner, Eva; Uhlmann, Susann; Wiedemann, Peter; Foja, Christian

2010-03-01

The aim of this study was to validate data arising from the Rostock Cornea Module (RCM) of the Heidelberg Retina Tomograph. Morphological parameters of the cornea were analyzed according to their dependency on patient's age. RCM measurements of 60 healthy eyes within 2 different age groups (group 1 <35 years, group 2 >50 years) were compared with the corneal thickness determined by the Oculus Pentacam and the endothelial cell density measured by the Tomey endothelial microscope, EM-2000. The mean corneal thickness measured with the Heidelberg Retina Tomograph/RCM was 517 +/- 31 microm and 542 +/- 30 microm with the Oculus Pentacam (correlation coefficient, R = 0.78). Group 1 showed a corneal thickness of 509 +/- 24 microm with the RCM and 531 +/- 27 microm with the Pentacam. In group 2, the corneal thickness was 525 +/- 34 microm and 553 +/- 29 microm, respectively. A significant increase in corneal thickness for older patients could be shown. The differences between the methods and the age groups were statistically significant (P < 0.0001). The average endothelial cell density measured with the RCM was 2779 +/- 472 cells per square millimeter. Between the age groups and the methods (RCM and endothelial microscope), no statistically significant differences could be found. Cell densities for the epithelial cell layers and keratocytes showed no significant correlation with age and sex of the patients. The RCM provides a reliable procedure for the evaluation of all corneal layers including morphological parameters. Endothelial cell densities either determined with the RCM or the EM-2000 are generally comparable to each other and showed no significant differences. It is suggested that lower corneal thickness measurements of the RCM can be caused by pressure during examination. An increased corneal thickness in the older group could be determined with the RCM and the Oculus Pentacam.

Unwanted pregnancy and traditional self-induced abortion methods known among women aged 15 to 49.

PubMed

Sensoy, Nazli; Dogan, Nurhan; Sen, Kubra; Aslan, Halit; Tore-Baser, Ayca

2015-05-01

To determine the traditional methods known and used to terminate an unwanted pregnancy and the fertility characteristics of married women. The descriptive cross-sectional study was conducted in Turkey at Afyonkarahisar Zübeyde Hanim Child and Maternity Hospital's outpatient clinic between December 27, 2010 and January 7, 2011, and comprised married women aged 17 to 49 who presented for an examination. Questions related to socio-demographic and fertility characteristics as well as known and used traditional abortion methods were included in the questionnaire which was administered through face-to-face interviews. SPSS 18.0 was used for statistical analysis. The median age of the 600 women in the study was 29.5 (range: 17-49) years. Overall, 134 (22.3%) women had experienced an unwanted pregnancy. In 53 (39.6%) cases, the unwanted pregnancy had occurred between the ages of 30 and 39, and 116(86.6%) women had married when they were between 15 and 24 (p< 0.008) years old. Pregnancy had been concluded normally in 78(58.2%)women with an unwanted pregnancy and 34(35.8%)preferred the withdrawal method for contraception. Traditional abortion methods were known to 413(68.8%)women, but only 8(1.3%) had used any of them. The harms of using a traditional abortion method were known to 464(77.3%)women. Very few women used traditional abortion methods to terminate pregnancy. Knowing the characteristics of women and their need for family planning should be the first priority for the prevention of unwanted pregnancies.

A Psychometric Study of the Bayley Scales of Infant and Toddler Development in Persian Language Children

PubMed Central

AZARI, Nadia; SOLEIMANI, Farin; VAMEGHI, Roshanak; SAJEDI, Firoozeh; SHAHSHAHANI, Soheila; KARIMI, Hossein; KRASKIAN, Adis; SHAHROKHI, Amin; TEYMOURI, Robab; GHARIB, Masoud

2017-01-01

Objective Bayley Scales of infant & toddler development is a well-known diagnostic developmental assessment tool for children aged 1–42 months. Our aim was investigating the validity & reliability of this scale in Persian speaking children. Materials & Methods The method was descriptive-analytic. Translation- back translation and cultural adaptation was done. Content & face validity of translated scale was determined by experts’ opinions. Overall, 403 children aged 1 to 42 months were recruited from health centers of Tehran, during years of 2013-2014 for developmental assessment in cognitive, communicative (receptive & expressive) and motor (fine & gross) domains. Reliability of scale was calculated through three methods; internal consistency using Cronbach’s alpha coefficient, test-retest and interrater methods. Construct validity was calculated using factor analysis and comparison of the mean scores methods. Results Cultural and linguistic changes were made in items of all domains especially on communication subscale. Content and face validity of the test were approved by experts’ opinions. Cronbach’s alpha coefficient was above 0.74 in all domains. Pearson correlation coefficient in various domains, were ≥ 0.982 in test retest method, and ≥0.993 in inter-rater method. Construct validity of the test was approved by factor analysis. Moreover, the mean scores for the different age groups were compared and statistically significant differences were observed between mean scores of different age groups, that confirms validity of the test. Conclusion The Bayley Scales of Infant and Toddler Development is a valid and reliable tool for child developmental assessment in Persian language children. PMID:28277556

Systems, methods and computer-readable media to model kinetic performance of rechargeable electrochemical devices

DOEpatents

Gering, Kevin L.

2013-01-01

A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics. The computing system also analyzes the cell information of the electrochemical cell with a Butler-Volmer (BV) expression modified to determine exchange current density of the electrochemical cell by including kinetic performance information related to pulse-time dependence, electrode surface availability, or a combination thereof. A set of sigmoid-based expressions may be included with the modified-BV expression to determine kinetic performance as a function of pulse time. The determined exchange current density may be used with the modified-BV expression, with or without the sigmoid expressions, to analyze other characteristics of the electrochemical cell. Model parameters can be defined in terms of cell aging, making the overall kinetics model amenable to predictive estimates of cell kinetic performance along the aging timeline.

Inferring Groundwater Age in an Alluvial Aquifer from Tracer Concentrations in the Stream - Little Wind River, Wyoming

NASA Astrophysics Data System (ADS)

Goble, D.; Gardner, W. P.; Naftz, D. L.; Solder, J. E.

2017-12-01

We use environmental tracers: CFC's, SF6, and 222Rn measured in stream water to determine volume and mean age of groundwater discharging to the Little Wind River, near Riverton, Wyoming. Samples of 222Rn were collected every 200 m along a 2 km reach, surrounding a known groundwater discharge zone. Nearby groundwater wells, in-stream piezometers and seepage meters were sampled for 222Rn, CFC's and SF6. Tracer concentrations measured in groundwater and in-stream piezometers were used to estimate the mean age of the subsurface system. High resolution 222Rn samples were used to determine the location and volume of groundwater inflow using a model of instream transport that includes radioactive decay and gas exchange with the atmosphere. The age of groundwater entering the stream was then estimated from in-stream measured CFC and SF6 concentrations using a new coupled stream transport and lumped-parameter groundwater age model. Ages derived from in-stream measurements were then compared to the age of subsurface water measured in piezometers, seepage meters, and groundwater wells. We then asses the ability of groundwater age inferred from in-stream samples to provide constraint on the age of the subsurface discharge to the stream. The ability to asses groundwater age from in-stream samples can provide a convenient method to constrain the regional distribution of groundwater circulation rates when groundwater sampling is challenging or wells are not in place.

Interaction in Bilingual Phonological Acquisition: Evidence from Phonetic Inventories

ERIC Educational Resources Information Center

Fabiano-Smith, Leah; Barlow, Jessica A.

2010-01-01

Purpose: To examine how interaction contributes to phonological acquisition in bilingual children in order to determine what constitutes typical development of bilingual speech sound inventories. Method: Twenty-four children, ages 3-4, were included: eight bilingual Spanish-English-speaking children, eight monolingual Spanish speakers, and eight…

Reducing Error Bars through the Intercalibration of Radioisotopic and Astrochronologic Time Scales for the Cenomanian/Turonian Boundary Interval, Western Interior Basin, USA

NASA Astrophysics Data System (ADS)

Meyers, S. R.; Siewert, S. E.; Singer, B. S.; Sageman, B. B.; Condon, D. J.; Obradovich, J. D.; Jicha, B.; Sawyer, D. A.

2010-12-01

We develop a new intercalibrated astrochronologic and radioisotopic time scale for the Cenomanian/Turonian (C/T) boundary interval near the GSSP in Colorado, where orbitally-influenced rhythmic strata host bentonites that contain sanidine and zircon suitable for 40Ar/39Ar and U-Pb dating. This provides a rare opportunity to directly intercalibrate two independent radioisotopic chronometers against an astrochronologic age model. We present paired 40Ar/39Ar and U-Pb ages from four bentonites spanning the Vascoceras diartianum to Pseudaspidoceras flexuosum biozones, utilizing both newly collected material and legacy sanidine samples of Obradovich (1993). Full 2σ uncertainties (decay constant, standard age, analytical sources) for the 40Ar/39Ar ages, using a weighted mean of 33-103 concordant age determinations and an age of 28.201 Ma for Fish Canyon sanidine (FCs), range from ±0.15 to 0.19 Ma, with ages from 93.67 to 94.43 Ma. The traditional FCs age of 28.02 Ma yields ages from 93.04 to 93.78 Ma with full uncertainties of ±1.58 Ma. Using the ET535 tracer, single zircon CA-TIMS 206Pb/238U ages determined from each bentonite record a range of ages (up to 2.1 Ma), however, in three of the four bentonites the youngest single crystal ages are statistically indistinguishable from the 40Ar/39Ar ages calculated relative to 28.201 Ma FCs, supporting this calibration. Using the new radioisotopic data and published astrochronology (Sageman et al., 2006) we develop an integrated C/T boundary time scale using a Bayesian statistical approach that builds upon the strength of each geochronologic method. Whereas the radioisotopic data provide an age with a well-defined uncertainty for each bentonite, the orbital time scale yields a more highly resolved estimate of the duration between stratigraphic horizons, including the radioisotopically dated beds. The Bayesian algorithm yields a C/T time scale that is statistically compatible with the astrochronologic and radioisotopic data, but with smaller uncertainty than either method could achieve alone. The results firmly anchor the floating orbital time scale and yield astronomically-recalibrated radioisotopic ages with full uncertainties that approach the EARTHTIME goal of permil resolution.

The prevalence and factors associated with obesity among adult women in Selangor, Malaysia

PubMed Central

Sidik, Sherina Mohd; Rampal, Lekhraj

2009-01-01

Introduction The prevalence of obesity in developing countries especially among women is on the rise. This matter should be taken seriously because it can burden the health care systems and lower the quality of life. Aim The purpose of this study was to determine the prevalence of obesity among adult women in Selangor and to determine factors associated with obesity among these women. Methods This community based cross sectional study was conducted in Selangor in January 2004. Multi stage stratified proportionate to size sampling method was used. Women aged 20–59 years old were included in this study. Data was collected using a questionnaire-guided interview method. The questionnaire consisted of questions on socio-demographic (age, ethnicity, religion, education level, occupation, monthly income, marital status), Obstetric & Gynaecology history, body mass index (BMI), and the Patient Health Questionnaire (PHQ-9). Results Out of 1032 women, 972 agreed to participate in this study, giving a response rate of 94.2%. The mean age was 37.91 ± 10.91. The prevalence of obesity among the respondents was 16.7% (mean = 1.83 ± 0.373). Obesity was found to be significantly associated with age (p = 0.013), ethnicity (p = 0.001), religion (p = 0.002), schooling (p = 0.020), educational level (p = 0.016), marital status (p = 0.001) and the history of suffering a miscarriage within the past 6 months (p = 0.023). Conclusion The prevalence of obesity among adult women in this study was high. This problem needs to be emphasized as the prevalence of obesity keeps increasing, and will continue to worsen unless appropriate preventive measures are taken. PMID:19358728

Fatty Acid Structure and Degradation Analysis in Fingerprint Residues

NASA Astrophysics Data System (ADS)

Pleik, Stefanie; Spengler, Bernhard; Schäfer, Thomas; Urbach, Dieter; Luhn, Steven; Kirsch, Dieter

2016-09-01

GC-MS investigations were carried out to elucidate the aging behavior of unsaturated fatty acids in fingerprint residues and to identify their degradation products in aged samples. For this purpose, a new sample preparation technique for fingerprint residues was developed that allows producing N-methyl- N-trimethylsilyl-trifluoroacetamide (MSTFA) derivatives of the analyzed unsaturated fatty acids and their degradation products. MSTFA derivatization catalyzed by iodotrimethylsilane enables the reliable identification of aldehydes and oxoacids as characteristic MSTFA derivatives in GCMS. The obtained results elucidate the degradation pathway of unsaturated fatty acids. Our study of aged fingerprint residues reveals that decanal is the main degradation product of the observed unsaturated fatty acids. Furthermore, oxoacids with different chain lengths are detected as specific degradation products of the unsaturated fatty acids. The detection of the degradation products and their chain length is a simple and effective method to determine the double bond position in unsaturated compounds. We can show that the hexadecenoic and octadecenoic acids found in fingerprint residues are not the pervasive fatty acids Δ9-hexadecenoic (palmitoleic acid) and Δ9-octadecenoic (oleic acid) acid but Δ6-hexadecenoic acid (sapienic acid) and Δ8-octadecenoic acid. The present study focuses on the structure identification of human sebum-specific unsaturated fatty acids in fingerprint residues based on the identification of their degradation products. These results are discussed for further investigations and method developments for age determination of fingerprints, which is still a tremendous challenge because of several factors affecting the aging behavior of individual compounds in fingerprints.

Fatty Acid Structure and Degradation Analysis in Fingerprint Residues.

PubMed

Pleik, Stefanie; Spengler, Bernhard; Schäfer, Thomas; Urbach, Dieter; Luhn, Steven; Kirsch, Dieter

2016-09-01

GC-MS investigations were carried out to elucidate the aging behavior of unsaturated fatty acids in fingerprint residues and to identify their degradation products in aged samples. For this purpose, a new sample preparation technique for fingerprint residues was developed that allows producing N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) derivatives of the analyzed unsaturated fatty acids and their degradation products. MSTFA derivatization catalyzed by iodotrimethylsilane enables the reliable identification of aldehydes and oxoacids as characteristic MSTFA derivatives in GCMS. The obtained results elucidate the degradation pathway of unsaturated fatty acids. Our study of aged fingerprint residues reveals that decanal is the main degradation product of the observed unsaturated fatty acids. Furthermore, oxoacids with different chain lengths are detected as specific degradation products of the unsaturated fatty acids. The detection of the degradation products and their chain length is a simple and effective method to determine the double bond position in unsaturated compounds. We can show that the hexadecenoic and octadecenoic acids found in fingerprint residues are not the pervasive fatty acids Δ9-hexadecenoic (palmitoleic acid) and Δ9-octadecenoic (oleic acid) acid but Δ6-hexadecenoic acid (sapienic acid) and Δ8-octadecenoic acid. The present study focuses on the structure identification of human sebum-specific unsaturated fatty acids in fingerprint residues based on the identification of their degradation products. These results are discussed for further investigations and method developments for age determination of fingerprints, which is still a tremendous challenge because of several factors affecting the aging behavior of individual compounds in fingerprints. Graphical Abstract ᅟ.

Using Inverse Problem Methods with Surveillance Data in Pneumococcal Vaccination

PubMed Central

Sutton, Karyn L.; Banks, H. T.; Castillo-Chavez, Carlos

2010-01-01

The design and evaluation of epidemiological control strategies is central to public health policy. While inverse problem methods are routinely used in many applications, this remains an area in which their use is relatively rare, although their potential impact is great. We describe methods particularly relevant to epidemiological modeling at the population level. These methods are then applied to the study of pneumococcal vaccination strategies as a relevant example which poses many challenges common to other infectious diseases. We demonstrate that relevant yet typically unknown parameters may be estimated, and show that a calibrated model may used to assess implemented vaccine policies through the estimation of parameters if vaccine history is recorded along with infection and colonization information. Finally, we show how one might determine an appropriate level of refinement or aggregation in the age-structured model given age-stratified observations. These results illustrate ways in which the collection and analysis of surveillance data can be improved using inverse problem methods. PMID:20209093

Standardised method of determining vibratory perception thresholds for diagnosis and screening in neurological investigation.

PubMed Central

Goldberg, J M; Lindblom, U

1979-01-01

Vibration threshold determinations were made by means of an electromagnetic vibrator at three sites (carpal, tibial, and tarsal), which were primarily selected for examining patients with polyneuropathy. Because of the vast variation demonstrated for both vibrator output and tissue damping, the thresholds were expressed in terms of amplitude of stimulator movement measured by means of an accelerometer, instead of applied voltage which is commonly used. Statistical analysis revealed a higher power of discimination for amplitude measurements at all three stimulus sites. Digital read-out gave the best statistical result and was also most practical. Reference values obtained from 110 healthy males, 10 to 74 years of age, were highly correlated with age for both upper and lower extremities. The variance of the vibration perception threshold was less than that of the disappearance threshold, and determination of the perception threshold alone may be sufficient in most cases. PMID:501379

Cell-production rates estimated by the use of vincristine sulphate and flow cytometry. II. Correlation between the cell-production rates of ageing ascites tumours and the number of S phase tumour cells.

PubMed

Barfod, I H; Barfod, N M

1980-01-01

A new method for the evaluation of cell production rates combining flow cytometry (FCM) and the stathmokinetic method using vincristine sulphate (VS) has been used for the analysis of three aneuploid ascites tumours at different stages of growth. Using this technique it was possible to estimate the well-known decrease in cell production rates of ageing ascites tumours. The percentage of normal host cells in the aneuploid tumours studied was easily determined by FCM prior to the calculation of the tumour cell-production rates. A correlation was found between the percentage of tumour cells in the S phase and the tumour cell-production rate. This correlation is probably explained by the gradual transfer of proliferating cells in S phase to resting G1 and G2 phases with increasing tumour age.

Spanish Multicenter Normative Studies (NEURONORMA Project): methods and sample characteristics.

PubMed

Peña-Casanova, Jordi; Blesa, Rafael; Aguilar, Miquel; Gramunt-Fombuena, Nina; Gómez-Ansón, Beatriz; Oliva, Rafael; Molinuevo, José Luis; Robles, Alfredo; Barquero, María Sagrario; Antúnez, Carmen; Martínez-Parra, Carlos; Frank-García, Anna; Fernández, Manuel; Alfonso, Verónica; Sol, Josep M

2009-06-01

This paper describes the methods and sample characteristics of a series of Spanish normative studies (The NEURONORMA project). The primary objective of our research was to collect normative and psychometric information on a sample of people aged over 49 years. The normative information was based on a series of selected, but commonly used, neuropsychological tests covering attention, language, visuo-perceptual abilities, constructional tasks, memory, and executive functions. A sample of 356 community dwelling individuals was studied. Demographics, socio-cultural, and medical data were collected. Cognitive normality was validated via informants and a cognitive screening test. Norms were calculated for midpoint age groups. Effects of age, education, and sex were determined. The use of these norms should improve neuropsychological diagnostic accuracy in older Spanish subjects. These data may also be of considerable use for comparisons with other normative studies. Limitations of these normative data are also commented on.

Health Hazard Appraisal in Patient Counseling

PubMed Central

LaDou, Joseph; Sherwood, John N.; Hughes, Lewis

1975-01-01

A program of annual health examinations was expanded to include counseling based on a computerized appraisal of individual patients' specific health hazard factors. Data obtained from a specially designed questionnaire, laboratory tests and a physical examination yielded a printout showing a number of weighted risk factors and their relation to ten leading causes of death as determined for that patient. From all of this information, a risk (“apparent”) age was developed for the patient. The results were reviewed with each patient, and methods of correcting health hazards were stressed. A total of 488 persons were appraised, and 107 were randomly reappraised in less than a year, with the finding that the net risk age was reduced by 1.4 years. Such a reduction in risk age is significant; it indicates that appraisal-based counseling is an effective method of altering priorities of health practices. PMID:1114813

Determination of the availability of appropriate aged flight rocket motors. [captive tests to determine case bond separation and grain bore cracking

NASA Technical Reports Server (NTRS)

Martin, P. J.

1974-01-01

A program to identify surplus solid rocket propellant engines which would be available for a program of functional integrity testing was conducted. The engines are classified as: (1) upper stage and apogee engines, (2) sounding rocket and launch vehicle engines, and (3) jato, sled, and tactical engines. Nearly all the engines were available because their age exceeds the warranted shelf life. The preference for testing included tests at nominal flight conditions, at design limits, and to establish margin limits. The principal failure modes of interest were case bond separation and grain bore cracking. Data concerning the identification and characteristics of each engine are tabulated. Methods for conducting the tests are described.

Determination of cadmium in urine by extraction and flameless atomic-absorption spectrophotometry Comparison of urine from smokers and non-smokers of different sex and age.

PubMed

Jawaid, M; Lind, B; Elinder, C G

1983-07-01

A method is presented for determining cadmium in urine by nameless atomic-absorption spectrophotometry after extraction. The sample is dried, ashed in the presence of nitric acid, and then the residue is dissolved in hydrochloric acid. Cadmium is extracted as its tetrahexylammonium iodide complex into methyl isobutyl ketone. The organic phase is analysed for cadmium by atomic-absorption spectrophotometry with electrothermal atomization. The median urinary excretion of cadmium for smokers aged 50-64 has been found to be 0.7 and 0.75 mug l . for males and females respectively, the values for non-smokers being 0.25 and 0.4mug l .

Prevalence and risk factors for renal scars in children with febrile UTI and/or VUR: A cross-sectional observational study of 565 consecutive patients

PubMed Central

Snodgrass, Warren T.; Shah, Anjana; Yang, Mary; Kwon, Jeannie; Villanueva, Carlos; Traylor, Janelle; Pritzker, Karen; Nakonezny, Paul A.; Haley, Robert W.; Bush, Nicol Corbin

2013-01-01

Purpose To determine prevalence and risk factors for renal scar in children referred for urologic assessment of febrile UTI and/or VUR. Methods Pre-determined risk factors for renal scar were prospectively recorded in consecutive patients referred for UTI/VUR. Age, gender, VUR grade, and reported number of febrile and non-febrile UTIs were analyzed with logistic regression to determine risk for focal cortical defects on non-acute DMSA. Results Of 565 consecutive children, 24 (4%) had congenital renal dysplasia and 84 (15.5%) had focal defect(s). VUR, especially grades IV–V, recurrent febrile UTI, and older age increased risk. For any age child with the same number of UTIs, VUR increased odds of renal defect 5.4-fold (OR = 5.4, 95% CI = 2.7–10.6, AUC = 0.759). Conclusions Focal DMSA defects were present in 15.5% of 565 consecutive children referred for febrile UTI and/or VUR; 4% had presumed congenital reflux nephropathy without cortical defect. All VUR grades increased risk for these defects, as did recurrent febrile UTIs and older age. However, 43% with grades IV–V VUR and 76% with recurrent UTI had normal DMSA. PMID:23465483

Determinants of Prelacteal Feeding in Rural Northern India

PubMed Central

Roy, Manas Pratim; Mohan, Uday; Singh, Shivendra Kumar; Singh, Vijay Kumar; Srivastava, Anand Kumar

2014-01-01

Background: Prelacteal feeding is an underestimated problem in a developing country like India, where infant mortality rate is quite high. The present study tried to find out the factors determining prelacteal feeding in rural areas of north India. Methods: A crosssectional study was conducted among recently delivered women of rural Uttar Pradesh, India. Multistage random sampling was used for selecting villages. From them, 352 recently delivered women were selected as the subjects, following systematic random sampling. Chi-square test and logistic regression were used to find out the predictors for prelacteal feeding. Results: Overall, 40.1% of mothers gave prelacteal feeding to their newborn. Factors significantly associated with such practice, after simple logistic regression, were age, caste, socioeconomic status, and place of delivery. At multivariate level, age (odds ratio (OR) = 1.76, 95% confidence interval (CI) = 1.13-2.74), caste and place of delivery (OR = 2.23, 95% CI = 1.21-4.10) were found to determine prelacteal feeding significantly, indicating that young age, high caste, and home deliveries could affect the practice positively. Conclusions: The problem of prelacteal feeding is still prevalent in rural India. Age, caste, and place of delivery were associated with the problem. For ensuring neonatal health, the problem should be addressed with due gravity, with emphasis on exclusive breast feeding. PMID:24932400

Children's Control/Display Stereotypes.

PubMed

Hoffmann, Errol R; Chan, Alan H S; Tai, Judy P C

2018-06-01

Objective The aim of this study was to determine control/display stereotypes for children of a range of ages and development of these stereotypes with age. Background Little is known about control/display stereotypes for children of different ages and the way in which these stereotypes develop with age. This study is part of a program to determine the need to design differentially for these age groups. Method We tested four groups of children with various tasks (age groups 5 to 7, 8 to 10, 11 to 13, 14 to 16), with about 30 in each group. Examples of common tasks were opening a bottle, turning on taps, and allocating numbers to keypads. More complex tasks involved rotating a control to move a display in a requested direction. Results Tasks with which different age groups were familiar showed no effect of age group. Different control/display arrangements generally showed an increase in stereotype strength with age, with dependence on the form of the control/display arrangement. Two-dimensional arrangements, with the control on the same plane as the display, had higher stereotype strength than three-dimensional arrangements for all age groups, suggesting an effect of familiarity with controls and displays with increasing age. Conclusion Children's control/display stereotypes do not differ greatly from those of adults, and hence, design for children older than 5 years of age, for control/display stereotypes, can be the same as that for adult populations. Application When designing devices for children, the relationship between controls and displays can be as for adult populations, for which there are considerable experimental data.

Map and table showing isotopic age data in Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Shew, Nora B.; DuBois, G.D.

1994-01-01

The source of the data reported here is a compilation of radiometric ages maintained in conjunction with the Alaska Mineral Resource Assessment Program (AMRAP) studies for Alaska. The symbol shape plotted at each location is coded for rock type, whether igneous, metamorphic, or other; the color of the symbol shows the geologic era or period for the Sample(s) at each locale. A list of references for each quadrangle is given to enable the user to find specific information including analytical data for each sample dated within a particular quadrangle. At the scale of this map, the very large number of Samples and the clustering of the samples in limited areas prevented the showing of individual sample numbers on the map.Synthesis and interpretation of any data set requires the user to evaluate the reliability or value of each component of the data set with respect to his or her intended use of the data. For geochronological data, this evaluation must be based on both analytical and geological criteria. Most age determinations are published with calculated estimates of analytical precision, Replicate analyses are infrequently performed; therefore, reported analytical precision is based on estimates of the precision of various components of the analysis and often on an intuitive factor to cover components that may have not been considered. Analytical accuracy is somewhat more difficult to determine; it is not only dependent on the actual measurement, it is also concerned with uncertainties in decay and abundance constants, uncertainties in the isotopic composition and size of the tracer for conventional K-Ar ages, and uncertainties in the Original isotopic composition of the sample, Geologic accuracy of a date is Variable; the interpretation of the meaning of an age determination, is important in the evaluation of its geologic accuracy. Potassium-argon, rubidium-strontium, and uranium-lead age determinations on a single sample can differ widely yet none or all may be wrong Given that the basic Conditions of each dating method were met, each method determines an age based on the equilibration of its particular isotopic system, yet these are different systems and they react to heat, pressure, and recrystallization in different ways.This map is a compilation and not a synthesis or interpretation. Its purpose is to help the user determine the dating coverage of areas of Alaska and gain access to the available data for the state or a project area. Interpretation of that data and evaluation of its suitability for use with any particular project is left to the user. Compilations, with sample data, have been published for much of the state; and are as follows: Wilson, and others (1979), southeastern Alaska; Wilson (1981), Aleutian Islands and Alaska Peninsula, Shew and Wilson (1981), southwestern Alaska; Wilson and others (1985), Yukon Crystalline terrane; Grybeck and others (1977), northern Alaska; Dadisman (1980), south-central Alaska.

High-throughput analysis of sulfatides in cerebrospinal fluid using automated extraction and UPLC-MS/MS.

PubMed

Blomqvist, Maria; Borén, Jan; Zetterberg, Henrik; Blennow, Kaj; Månsson, Jan-Eric; Ståhlman, Marcus

2017-07-01

Sulfatides (STs) are a group of glycosphingolipids that are highly expressed in brain. Due to their importance for normal brain function and their potential involvement in neurological diseases, development of accurate and sensitive methods for their determination is needed. Here we describe a high-throughput oriented and quantitative method for the determination of STs in cerebrospinal fluid (CSF). The STs were extracted using a fully automated liquid/liquid extraction method and quantified using ultra-performance liquid chromatography coupled to tandem mass spectrometry. With the high sensitivity of the developed method, quantification of 20 ST species from only 100 μl of CSF was performed. Validation of the method showed that the STs were extracted with high recovery (90%) and could be determined with low inter- and intra-day variation. Our method was applied to a patient cohort of subjects with an Alzheimer's disease biomarker profile. Although the total ST levels were unaltered compared with an age-matched control group, we show that the ratio of hydroxylated/nonhydroxylated STs was increased in the patient cohort. In conclusion, we believe that the fast, sensitive, and accurate method described in this study is a powerful new tool for the determination of STs in clinical as well as preclinical settings. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

Sex determination using cheiloscopy and mandibular canine index as a tool in forensic dentistry.

PubMed

Singh, Jaspal; Gupta, Kapil D; Sardana, Varun; Balappanavar, Ashwini Y; Malhotra, Garima

2012-07-01

Establishment of a person's individuality is important for legal as well as humanitarian purpose and gender determination is an essential step in identifying an individual. In forensic odontology the sum total of all the characteristics of teeth and their associated structures provide a unique totality and forms the basis for personal identification. To investigate the accuracy of various methods employed in sex determination such as cheiloscopy and mandibular canine index (MCI). The study group comprises adults between 20 and 25 years of age, who were assessed for gender identification using lip prints and MCI. The results were subjected to statistical analysis. MCI and lip prints were found to be accurate and specific for sex determination. There is scope for use of these methods in criminal investigations, personal identification, and genetic studies. Thus, dental tissues make good witnesses although they speak softly, they never lie and they never forget.

Successful endoscopic third ventriculostomy in children depends on age and etiology of hydrocephalus: outcome analysis in 51 pediatric patients.

PubMed

Duru, Soner; Peiro, Jose L; Oria, Marc; Aydin, Emrah; Subasi, Canan; Tuncer, Cengiz; Rekate, Harold L

2018-04-25

Endoscopic third ventriculostomy (ETV) has become the method of choice in the treatment of hydrocephalus. Age and etiology could determine success rates (SR) of ETV. The purpose of this study is to assess these factors in pediatric population. Retrospective study on 51 children with obstructive hydrocephalus that underwent ETV was performed. The patients were divided into three groups per their age at the time of the treatment: < 6, 6-24, and > 24 months of age. All ETV procedures were performed by the same neurosurgeon. Overall SR of ETV was 80% (40/51) for all etiologies and ages. In patients < 6 months of age SR was 56.2% (9/16), while 6-24 months of age was 88.9% (16/18) and > 24 months was 94.1% (16/17) (p = 0.012). The highest SR was obtained on aqueductal stenosis. SR of posthemorrhagic, postinfectious, and spina bifida related hydrocephalus was 60% (3/5), 50% (1/2), and 14.3% (1/7), respectively. While SR rate at the first ETV attempt was 85.3%, it was 76.9% in patients with V-P shunt performed previously (p = 0.000). Factors indicating a potential failure of ETV were young age and etiology such as spina bifida, other than isolated aqueductal stenosis. ETV is the method of choice even in patients with former shunting. Fast healing, distensible skulls, and lower pressure gradient in younger children, all can play a role in ETV failure. Based on our experience, ETV could be the first method of choice for hydrocephalus even in children younger than 6 months of age.

COMPARISON OF DIFFERENT TRUNK ENDURANCE TESTING METHODS IN COLLEGE‐AGED INDIVIDUALS

PubMed Central

Krier, Amber D.; Nelson, Julie A.; Rogers, Michael A.; Stuke, Zachariah O.; Smith, Barbara S.

2012-01-01

Objective: Determine the reliability of two different modified (MOD1 and MOD2) testing methods compared to a standard method (ST) for testing trunk flexion and extension endurance. Participants: Twenty‐eight healthy individuals (age 26.4 ± 3.2 years, height 1.75 ± m, weight 71.8 ± 10.3 kg, body mass index 23.6 ± 3.4 m/kg2). Method: Trunk endurance time was measured in seconds for flexion and extension under the three different stabilization conditions. The MOD1 testing procedure utilized a female clinician (70.3 kg) and MOD2 utilized a male clinician (90.7 kg) to provide stabilization as opposed to the ST method of belt stabilization. Results: No significant differences occurred between flexion and extension times. Intraclass correlations (ICCs3,1) for the different testing conditions ranged from .79 to .95 (p <.000) and are found in Table 3. Concurrent validity using the ST flexion times as the gold standard coefficients were .95 for MOD1 and .90 for MOD2. For ST extension, coefficients were .91 and .80, for MOD1 and MOD2 respectively (p <.01). Conclusions: These methods proved to be a reliable substitute for previously accepted ST testing methods in normal college‐aged individuals. These modified testing procedures can be implemented in athletic training rooms and weight rooms lacking appropriate tables for the ST testing. Level of Evidence: 3 PMID:23091786

Methods and complications of septic induced abortion in patients managed at a tertiary care hospital.

PubMed

Jabeen, Alia; Dawood, Nasira Sabiha; Riaz, Shazia; Tanveer, Shamaila

2013-01-01

To study the methods used for the termination of pregnancy and associated complications of induced abortion. This descriptive study was conducted in the department of obstetrics and gynaecology, Fauji Foundation Hospital Rawalpindi. One Hundred patients were included in the study who was admitted with the history of induced abortion. The patients were assessed by detailed history and thorough clinical examination according to the study protocol. Data was collected on a specially designed Performa. Patients were interviewed in privacy and factors contributing to termination of pregnancy like age, parity, socioeconomic status and contraceptive failure were determined. Methods used for the procedure, status of abortionist were asked. Complications were determined by history, clinical examination and ultrasound examination. In view of all above data recommendations of preventing unwanted pregnancies were made. All patients were married and 57% of women belonged to age group of 31-40 years. Fifty-four 54% were grand multipara. In 63% of patients, induced abortion was carried out by Dai's. Most commonly used method was instrumentation (72%). Financial problems (46.7% ) and high parity (40%) were the most common factors contributing to termination of pregnancy. Serious complications like uterine perforation with or without bowel injury were accounted in 13% of women, septicaemia in 61%, peritonitis in 15% and DIC in 2%. During the study period illegally induced abortion accounted for 2% maternal deaths. Prevalence of poverty, illiteracy, grand multiparity and non-compliance of contraception were strong determinants of induced abortion, instrumentation being the most commonly used procedure resulting in high morbidity and mortality.

High-throughput analysis of yeast replicative aging using a microfluidic system

PubMed Central

Jo, Myeong Chan; Liu, Wei; Gu, Liang; Dang, Weiwei; Qin, Lidong

2015-01-01

Saccharomyces cerevisiae has been an important model for studying the molecular mechanisms of aging in eukaryotic cells. However, the laborious and low-throughput methods of current yeast replicative lifespan assays limit their usefulness as a broad genetic screening platform for research on aging. We address this limitation by developing an efficient, high-throughput microfluidic single-cell analysis chip in combination with high-resolution time-lapse microscopy. This innovative design enables, to our knowledge for the first time, the determination of the yeast replicative lifespan in a high-throughput manner. Morphological and phenotypical changes during aging can also be monitored automatically with a much higher throughput than previous microfluidic designs. We demonstrate highly efficient trapping and retention of mother cells, determination of the replicative lifespan, and tracking of yeast cells throughout their entire lifespan. Using the high-resolution and large-scale data generated from the high-throughput yeast aging analysis (HYAA) chips, we investigated particular longevity-related changes in cell morphology and characteristics, including critical cell size, terminal morphology, and protein subcellular localization. In addition, because of the significantly improved retention rate of yeast mother cell, the HYAA-Chip was capable of demonstrating replicative lifespan extension by calorie restriction. PMID:26170317

Increased long-term recreational physical activity is associated with older age at natural menopause among heavy smokers: the California Teachers Study

PubMed Central

Emaus, Aina; Dieli-Conwright, Christina; Xu, Xinxin; Lacey, James V.; Ingles, Sue A.; Reynolds, Peggy; Bernstein, Leslie; Henderson, Katherine D.

2012-01-01

Objective Although physical activity modulates the hypothalamic-ovarian-pituitary axis, the few studies investigating whether physical activity is associated with age at natural menopause have had mixed results. We set out to determine whether physical activity is associated with the timing of natural menopause in a large cohort of California women, overall, and by smoking history. Methods We investigated the association between long-term physical activity (hours/week/year) and age at natural menopause among 97,945 women in the California Teachers Study. Multivariable Cox proportional hazards regression methods were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). The impact of cigarette smoking (never smoker, former-light smoker, former-heavy smoker, current-light smoker, current-heavy smoker) as an effect modifier was evaluated. Results In a multivariable model adjusting for body mass index at age 18, age at menarche, race/ethnicity, and age at first full-term pregnancy, increased physical activity was statistically significantly associated with older age at natural menopause (ptrend=0.005). Higher body mass index at age 18 (ptrend=0.0003) and older age at menarche (ptrend=0.0003) were also associated with older age at natural menopause. Hispanic ethnicity (vs. non-Hispanic whites, HR 1.17, 95% CI 1.09–1.26), current smokers (vs. never smokers, HR 1.68, 95% CI 1.60–1.75 for current-light smokers; HR 1.38, 95% CI 1.33–1.44 for current-heavy smokers) and older age at first full-term pregnancy (HR≥29, 2+ full-term pregnancies vs. <29, 2+ full-term pregnancies 1.10, 95% CI 1.06–1.14) were associated with earlier age at natural menopause. Upon stratification by smoking history, increased physical activity was statistically significantly associated with older natural menopause among heavy smokers only (HRHighest vs. Lowest quartile 0.88, 95% CI 0.81–0.97, ptrend=0.02 for former-heavy smokers; HRHighest vs. Lowest quartile 0.89, 95% CI 0.80–0.99, ptrend=0.04 for current-heavy smokers). Conclusion Age at natural menopause is a complex trait; the determinants of age at natural menopause, including physical activity, may differ by smoking status. PMID:23435025

Age estimation based on pulp chamber volume of first molars from cone-beam computed tomography images.

PubMed

Ge, Zhi-pu; Ma, Ruo-han; Li, Gang; Zhang, Ji-zong; Ma, Xu-chen

2015-08-01

To establish a method that can be used for human age estimation on the basis of pulp chamber volume of first molars and to identify whether the method is good enough for age estimation in real human cases. CBCT images of 373 maxillary first molars and 372 mandibular first molars were collected to establish the mathematical model from 190 female and 213 male patients whose age between 12 and 69 years old. The inclusion criteria of the first molars were: no caries, no excessive tooth wear, no dental restorations, no artifacts due to metal restorative materials present in adjacent teeth, and no pulpal calcification. All the CBCT images were acquired with a CBCT unit NewTom VG (Quantitative Radiology, Verona, Italy) and reconstructed with a voxel-size of 0.15mm. The images were subsequently exported as DICOM data sets and imported into an open source 3D image semi-automatic segmenting and voxel-counting software ITK-SNAP 2.4 for the calculation of pulp chamber volumes. A logarithmic regression analysis was conducted with age as dependent variable and pulp chamber volume as independent variables to establish a mathematical model for the human age estimation. To identify the precision and accuracy of the model for human age estimation, another 104 maxillary first molars and 103 mandibular first molars from 55 female and 57 male patients whose age between 12 and 67 years old were collected, too. Mean absolute error and root mean square error between the actual age and estimated age were used to determine the precision and accuracy of the mathematical model. The study was approved by the Institutional Review Board of Peking University School and Hospital of Stomatology. A mathematical model was suggested for: AGE=117.691-26.442×ln (pulp chamber volume). The regression was statistically significant (p=0.000<0.01). The coefficient of determination (R(2)) was 0.564. There is a mean absolute error of 8.122 and root mean square error of 5.603 between the actual age and estimated age for all the tested teeth. The pulp chamber volume of first molar is a useful index for the estimation of human age with reasonable precision and accuracy. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The age of peak performance in Ironman triathlon: a cross-sectional and longitudinal data analysis

PubMed Central

2013-01-01

Background The aims of the present study were, firstly, to investigate in a cross-sectional analysis the age of peak Ironman performance within one calendar year in all qualifiers for Ironman Hawaii and Ironman Hawaii; secondly, to determine in a longitudinal analysis on a qualifier for Ironman Hawaii whether the age of peak Ironman performance and Ironman performance itself change across years; and thirdly, to determine the gender difference in performance. Methods In a cross-sectional analysis, the age of the top ten finishers for all qualifier races for Ironman Hawaii and Ironman Hawaii was determined in 2010. For a longitudinal analysis, the age and the performance of the annual top ten female and male finishers in a qualifier for Ironman Hawaii was determined in Ironman Switzerland between 1995 and 2010. Results In 19 of the 20 analyzed triathlons held in 2010, there was no difference in the age of peak Ironman performance between women and men (p > 0.05). The only difference in the age of peak Ironman performance between genders was in ‘Ironman Canada’ where men were older than women (p = 0.023). For all 20 races, the age of peak Ironman performance was 32.2 ± 1.5 years for men and 33.0 ± 1.6 years for women (p > 0.05). In Ironman Switzerland, there was no difference in the age of peak Ironman performance between genders for top ten women and men from 1995 to 2010 (F = 0.06, p = 0.8). The mean age of top ten women and men was 31.4 ± 1.7 and 31.5 ± 1.7 years (Cohen's d = 0.06), respectively. The gender difference in performance in the three disciplines and for overall race time decreased significantly across years. Men and women improved overall race times by approximately 1.2 and 4.2 min/year, respectively. Conclusions Women and men peak at a similar age of 32–33 years in an Ironman triathlon with no gender difference. In a qualifier for Ironman Hawaii, the age of peak Ironman performance remained unchanged across years. In contrast, gender differences in performance in Ironman Switzerland decreased during the studied period, suggesting that elite female Ironman triathletes might still narrow the gender gap in the future. PMID:24004814

Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998–2009

PubMed Central

Cuong, Hoang Quoc; Hien, Nguyen Tran; Duong, Tran Nhu; Phong, Tran Vu; Cam, Nguyen Nhat; Farrar, Jeremy; Nam, Vu Sinh; Thai, Khoa T. D.; Horby, Peter

2011-01-01

Background An estimated 2.4 billion people live in areas at risk of dengue transmission, therefore the factors determining the establishment of endemic dengue in areas where transmission suitability is marginal is of considerable importance. Hanoi, Vietnam is such an area, and following a large dengue outbreak in 2009, we set out to determine if dengue is emerging in Hanoi. Methods and Principal Findings We undertook a temporal and spatial analysis of 25,983 dengue cases notified in Hanoi between 1998 and 2009. Age standardized incidence rates, standardized age of infection, and Standardized Morbidity Ratios (SMR) were calculated. A quasi-Poisson regression model was used to determine if dengue incidence was increasing over time. Wavelet analysis was used to explore the periodicity of dengue transmission and the association with climate variables. After excluding the two major outbreak years of 1998 and 2009 and correcting for changes in population age structure, we identified a significant annual increase in the incidence of dengue cases over the period 1999–2008 (incidence rate ratio  = 1.38, 95% confidence interval  = 1.20–1.58, p value  = 0.002). The age of notified dengue cases in Hanoi is high, with a median age of 23 years (mean 26.3 years). After adjusting for changes in population age structure, there was no statistically significant change in the median or mean age of dengue cases over the period studied. Districts in the central, highly urban, area of Hanoi have the highest incidence of dengue (SMR>3). Conclusions Hanoi is a low dengue transmission setting where dengue incidence has been increasing year on year since 1999. This trend needs to be confirmed with serological surveys, followed by studies to determine the underlying drivers of this emergence. Such studies can provide insights into the biological, demographic, and environmental changes associated with vulnerability to the establishment of endemic dengue. PMID:21980544

Factors determining access to oral health services among children aged less than 12 years in Peru.

PubMed

Azañedo, Diego; Hernández-Vásquez, Akram; Casas-Bendezú, Mixsi; Gutiérrez, César; Agudelo-Suárez, Andrés A; Cortés, Sandra

2017-01-01

Background: Understanding problems of access to oral health services requires knowledge of factors that determine access. This study aimed to evaluate factors that determine access to oral health services among children aged <12 years in Peru between 2014 and 2015. Methods: We performed a secondary data analysis of 71,614 Peruvian children aged <12 years and their caregivers. Data were obtained from the Survey on Demography and Family Health 2014-2015 (Encuesta Demográfica y de Salud Familiar - ENDES). Children's access to oral health services within the previous 6 months was used as the dependent variable (i.e. Yes/No), and the Andersen and col model was used to select independent variables. Predisposing (e.g., language spoken by  tutor or guardian, wealth level, caregivers' educational level, area of residence, natural region of residence, age, and sex) and enabling factors (e.g. type of health insurance) were considered. Descriptive statistics were calculated, and multivariate analysis was performed using generalized linear models (Poisson family). Results: Of all the children, 51% were males, 56% were aged <5 years, and 62.6% lived in urban areas. The most common type of health insurance was Integral Health Insurance (57.8%), and most respondents were in the first quintile of wealth (31.6%). Regarding caregivers, the most common educational level was high school (43.02%) and the most frequently spoken language was Spanish (88.4%). Univariate analysis revealed that all variables, except sex and primary educational level, were statistically significant. After adjustment, sex, area of residence, and language were insignificant, whereas the remaining variables were statistically significant. Conclusions: Wealth index, caregivers' education level, natural region of residence, age, and type of health insurance are factors that determine access to oral health services among children aged <12 years in Peru. These factors should be considered when devising strategies to mitigate against inequities in access to oral health services.

Factors determining access to oral health services among children aged less than 12 years in Peru

PubMed Central

Azañedo, Diego; Hernández-Vásquez, Akram; Casas-Bendezú, Mixsi; Gutiérrez, César; Agudelo-Suárez, Andrés A.; Cortés, Sandra

2017-01-01

Background: Understanding problems of access to oral health services requires knowledge of factors that determine access. This study aimed to evaluate factors that determine access to oral health services among children aged <12 years in Peru between 2014 and 2015. Methods: We performed a secondary data analysis of 71,614 Peruvian children aged <12 years and their caregivers. Data were obtained from the Survey on Demography and Family Health 2014-2015 (Encuesta Demográfica y de Salud Familiar - ENDES). Children’s access to oral health services within the previous 6 months was used as the dependent variable (i.e. Yes/No), and the Andersen and col model was used to select independent variables. Predisposing (e.g., language spoken by  tutor or guardian, wealth level, caregivers’ educational level, area of residence, natural region of residence, age, and sex) and enabling factors (e.g. type of health insurance) were considered. Descriptive statistics were calculated, and multivariate analysis was performed using generalized linear models (Poisson family). Results: Of all the children, 51% were males, 56% were aged <5 years, and 62.6% lived in urban areas. The most common type of health insurance was Integral Health Insurance (57.8%), and most respondents were in the first quintile of wealth (31.6%). Regarding caregivers, the most common educational level was high school (43.02%) and the most frequently spoken language was Spanish (88.4%). Univariate analysis revealed that all variables, except sex and primary educational level, were statistically significant. After adjustment, sex, area of residence, and language were insignificant, whereas the remaining variables were statistically significant. Conclusions: Wealth index, caregivers’ education level, natural region of residence, age, and type of health insurance are factors that determine access to oral health services among children aged <12 years in Peru. These factors should be considered when devising strategies to mitigate against inequities in access to oral health services. PMID:29527289

Further Evidence of Auditory Extinction in Aphasia

ERIC Educational Resources Information Center

Marshall, Rebecca Shisler; Basilakos, Alexandra; Love-Myers, Kim

2013-01-01

Purpose: Preliminary research ( Shisler, 2005) suggests that auditory extinction in individuals with aphasia (IWA) may be connected to binding and attention. In this study, the authors expanded on previous findings on auditory extinction to determine the source of extinction deficits in IWA. Method: Seventeen IWA (M[subscript age] = 53.19 years)…

Aging Affects Identification of Vocal Emotions in Semantically Neutral Sentences

ERIC Educational Resources Information Center

Dupuis, Kate; Pichora-Fuller, M. Kathleen

2015-01-01

Purpose: The authors determined the accuracy of younger and older adults in identifying vocal emotions using the Toronto Emotional Speech Set (TESS; Dupuis & Pichora-Fuller, 2010a) and investigated the possible contributions of auditory acuity and suprathreshold processing to emotion identification accuracy. Method: In 2 experiments, younger…

Potential transport and degradation of “Aged” pesticide residues in soil

USDA-ARS?s Scientific Manuscript database

“Aging” has been shown to affect the sorption-desorption of pesticides in the soil, which in turn can control transport and degradation processes. Aging effects have been characterized by batch sequential extraction methods, in which sorption coefficients (i.e. Kd) are determined for the chemical re...

Observing Children's Stress Behaviors in a Kindergarten Classroom

ERIC Educational Resources Information Center

Jackson, Lori A.

2009-01-01

This study used qualitative methods to determine whether kindergarten children exhibited stress behaviors during the academic work period of the day. Sixteen children (8 male, 8 female) ages 5-6 years were observed. The data consisted of classroom observations by the researcher, open-ended interviews with teachers, artifacts collected from the…