Dental occlusion analysis in the Mesolithic-Neolithic Age, Bronze Age, and Roman to Medieval times in Serbia: Tooth size comparison in skeletal samples.

PubMed

Pajević, Tina; Glišić, Branislav

2017-05-01

Anthropological studies have reported that tooth size decreases in the context of diet changes. Some investigations have found a reverse trend in tooth size from the prehistoric to the modern times. The aims of this study were to analyze tooth size in skeletal samples from Mesolithic-Neolithic Age, Bronze Age, and Roman to Medieval times to determine sex differences and establish a temporal trend in tooth size in the aforementioned periods. Well-preserved permanent teeth were included in the investigation. The mesiodistal (MD) diameter of all teeth and buccolingual (BL) diameter of the molars were measured. Effects of sex and site were tested by one-way ANOVA, and the combined effect of these factors was analyzed by UNIANOVA. Sexual dimorphism was present in the BL diameters of all molars and MD diameters of the upper first and the lower third molar. The lower canine was the most dimorphic tooth in the anterior region. The MD diameter of most teeth showed no significant difference between the groups, (sample from: Mesolithic-Neolithic Age-group 1; Bronze Age-group 2; Roman times-group 3; Medieval times-group 4), whereas the BL diameters of the upper second and the lower first molar were the largest in the first group. Multiple comparisons revealed a decrease in the BL diameter of the upper second and the lower first molar from the first to the later groups. Lower canine MD diameter exhibited an increase in the fourth group compared to the second group. On the basis of the MD diameter, a temporal trend could not be observed for most of the teeth. The lower canine exhibited an increase in the MD diameter from the prehistoric to the Medieval times. Changes of BL diameter were more homogeneous, suggesting that the temporal trend of molar size decreased from the Mesolithic-Neolithic to Medieval times in Serbia. Copyright © 2017. Published by Elsevier Ltd.

Infant size at 8 months of age: relationship to maternal use of alcohol, nicotine, and caffeine during pregnancy.

PubMed

Barr, H M; Streissguth, A P; Martin, D C; Herman, C S

1984-09-01

To examine the relationship of maternal alcohol consumption, caffeine use, and smoking to infant size at 8 months of age, a follow-up cohort of 453 infants was examined at birth and again at their 8-month birthday. Even after adjustment for other relevant variables, maternal alcohol use during early pregnancy (average ounces of absolute alcohol by self-report) was significantly related to infant weight and length at 8 months of age but not as strongly related to head circumference. Maternal smoking and caffeine use during pregnancy were not significantly related to infant size at 8 months, although nicotine use had been highly related to the birth size in this sample. Maternal use of marijuana was significantly and negatively related to infant length at 8 months of age, but not to weight or head circumference. The magnitude of the growth retardation is smaller at 8 months than at birth in this sample of infants whose mothers are primarily white, married, and well-educated, and who report a variety of alcohol use patterns. Significance was tested using multiple regression analyses that adjusted for the effects of nicotine use, caffeine use, birth order, maternal height, and gestational age as well as sex and age of infant at examination.

Influence of tree spatial pattern and sample plot type and size on inventory

Treesearch

John-Pascall Berrill; Kevin L. O' Hara

2012-01-01

Sampling with different plot types and sizes was simulated using tree location maps and data collected in three even-aged coast redwood (Sequoia sempervirens) stands selected to represent uniform, random, and clumped spatial patterns of tree locations. Fixed-radius circular plots, belt transects, and variable-radius plots were installed by...

THE ROLE OF QUENCHING TIME IN THE EVOLUTION OF THE MASS–SIZE RELATION OF PASSIVE GALAXIES FROM THE WISP SURVEY

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

Zanella, A.; Scarlata, C.; Rutkowski, M. J.

2016-06-20

We analyze how passive galaxies at z ∼ 1.5 populate the mass–size plane as a function of their stellar age, to understand if the observed size growth with time can be explained with the appearance of larger quenched galaxies at lower redshift. We use a sample of 32 passive galaxies extracted from the Wide Field Camera 3 Infrared Spectroscopic Parallel (WISP) survey with spectroscopic redshift 1.3 ≲ z ≲ 2.05, specific star formation rates lower than 0.01 Gyr{sup −1}, and stellar masses above 4.5 × 10{sup 10} M {sub ⊙}. All galaxies have spectrally determined stellar ages from fitting ofmore » their rest-frame optical spectra and photometry with stellar population models. When dividing our sample into young (age ≤2.1 Gyr) and old (age >2.1 Gyr) galaxies we do not find a significant trend in the distributions of the difference between the observed radius and that predicted by the mass–size relation. This result indicates that the relation between the galaxy age and its distance from the mass–size relation, if it exists, is rather shallow, with a slope α ≳ −0.6. At face value, this finding suggests that multiple dry and/or wet minor mergers, rather than the appearance of newly quenched galaxies, are mainly responsible for the observed time evolution of the mass–size relation in passive galaxies.« less

Seasonal variation in size-dependent survival of juvenile Atlantic salmon (Salmo salar): Performance of multistate capture-mark-recapture models

USGS Publications Warehouse

Letcher, B.H.; Horton, G.E.

2008-01-01

We estimated the magnitude and shape of size-dependent survival (SDS) across multiple sampling intervals for two cohorts of stream-dwelling Atlantic salmon (Salmo salar) juveniles using multistate capture-mark-recapture (CMR) models. Simulations designed to test the effectiveness of multistate models for detecting SDS in our system indicated that error in SDS estimates was low and that both time-invariant and time-varying SDS could be detected with sample sizes of >250, average survival of >0.6, and average probability of capture of >0.6, except for cases of very strong SDS. In the field (N ??? 750, survival 0.6-0.8 among sampling intervals, probability of capture 0.6-0.8 among sampling occasions), about one-third of the sampling intervals showed evidence of SDS, with poorer survival of larger fish during the age-2+ autumn and quadratic survival (opposite direction between cohorts) during age-1+ spring. The varying magnitude and shape of SDS among sampling intervals suggest a potential mechanism for the maintenance of the very wide observed size distributions. Estimating SDS using multistate CMR models appears complementary to established approaches, can provide estimates with low error, and can be used to detect intermittent SDS. ?? 2008 NRC Canada.

Altitudinal variation in age and body size in Yunnan pond frog (Pelophylax pleuraden).

PubMed

Lou, Shang Ling; Jin, Long; Liu, Yan Hong; Mi, Zhi Ping; Tao, Gang; Tang, Yu Mei; Liao, Wen Bo

2012-08-01

Large-scale systematic patterns of body size are a basic concern of evolutionary biology. Identifying body size variation along altitudinal gradients may help us to understand the evolution of life history of animals. In this study, we investigated altitudinal variation in body size, age and growth rate in Chinese endemic frog, Pelophylax pleuraden. Data sampled from five populations covering an altitudinal span of 1413 to 1935 m in Sichuan province revealed that body size from five populations did not co-vary with altitudes, not following Bergmann's rule. Average adult SVL differed significantly among populations in males, but not in females. For both sexes, average adult age differed significantly among populations. Post-metamorphic growth rate did not co-vary with altitude, and females grew faster than males in all populations. When controlling the effect of age, body size did not differ among populations in both sexes, suggesting that age did not affect variation in body size among populations. For females, there may be other factors, such as the allocation of energy between growth and reproduction, that eliminated the effect of age on body size. To our minds, the major reason of body size variation among populations in male frogs may be related to individual longevity. Our findings also suggest that factors other than age and growth rate may contribute to size differences among populations.

Dynamics and structure of an aging binary colloidal glass

NASA Astrophysics Data System (ADS)

Lynch, Jennifer M.; Cianci, Gianguido C.; Weeks, Eric R.

2008-09-01

We study aging in a colloidal suspension consisting of micron-sized particles in a liquid. This system is made glassy by increasing the particle concentration. We observe samples composed of particles of two sizes, with a size ratio of 1:2.1 and a volume fraction ratio 1:6, using fast laser scanning confocal microscopy. This technique yields real-time, three-dimensional movies deep inside the colloidal glass. Specifically, we look at how the size, motion, and structural organization of the particles relate to the overall aging of the glass. Particles move in spatially heterogeneous cooperative groups. These mobile regions tend to be richer in small particles, and these small particles facilitate the motion of nearby particles of both sizes.

Evidence for age-associated cognitive decline from Internet game scores.

PubMed

Geyer, Jason; Insel, Philip; Farzin, Faraz; Sternberg, Daniel; Hardy, Joseph L; Scanlon, Michael; Mungas, Dan; Kramer, Joel; Mackin, R Scott; Weiner, Michael W

2015-06-01

Lumosity's Memory Match (LMM) is an online game requiring visual working memory. Change in LMM scores may be associated with individual differences in age-related changes in working memory. Effects of age and time on LMM learning and forgetting rates were estimated using data from 1890 game sessions for users aged 40 to 79 years. There were significant effects of age on baseline LMM scores (β = -.31, standard error or SE = .02, P < .0001) and lower learning rates (β = -.0066, SE = .0008, P < .0001). A sample size of 202 subjects/arm was estimated for a 1-year study for subjects in the lower quartile of game performance. Online memory games have the potential to identify age-related decline in cognition and to identify subjects at risk for cognitive decline with smaller sample sizes and lower cost than traditional recruitment methods.

Intrafamilial clustering of anti-ATLA-positive persons.

PubMed

Kajiyama, W; Kashiwagi, S; Hayashi, J; Nomura, H; Ikematsu, H; Okochi, K

1986-11-01

A total of 1,333 persons in 627 families were surveyed for presence of antibody to adult T-cell leukemia-associated antigen (anti-ATLA). Each person was classified according to the anti-ATLA status (positive for sample 1, negative for sample 2) of the head of household of his or her family. In sample 1, the sex- and age-standardized prevalence of anti-ATLA was 38.5%. This was five times as high as the standardized prevalence in sample 2 (7.8%). There were significant differences in prevalence of anti-ATLA between males in samples 1 and 2 and between females in samples 1 and 2. In every age group, prevalence in sample 1 was greater than that in sample 2 except for males aged 60-69 years. In each of four subareas, families in sample 1 had higher standardized prevalence (29.6-42.5%) than families in sample 2 (6.0-9.7%). Although crude prevalence decreased with family size in sample 1 (62.1-25.4%) as well as in sample 2, indirectly standardized prevalence was almost equal within each sample, regardless of number of family members. The degree of aggregation was independent of locality and family size. These data suggest that anti-ATLA-positive persons aggregate in family units.

Apatite (U-Th-Sm)/He age dispersion arising from analysis of variable grain sizes and broken crystals - examples from the Scottish Southern Uplands

NASA Astrophysics Data System (ADS)

Łuszczak, Katarzyna; Persano, Cristina; Stuart, Finlay; Brown, Roderick

2016-04-01

Apatite (U-Th-Sm)/He (AHe) thermochronometry is a powerful technique for deciphering denudation of the uppermost crust. However, the age dispersion of single grains from the same rock is typical, and this hampers establishing accurate thermal histories when low grain numbers are analysed. Dispersion arising from the analysis of broken crystal fragments[1] has been proposed as an important cause of age dispersion, along with grain size and radiation damage. A new tool, Helfrag[2], allows constraints to be placed on the low temperature history derived from the analysis of apatite crystal fragments. However, the age dispersion model has not been fully tested on natural samples yet. We have performed AHe analysis of multiple (n = 20-25) grains from four rock samples from the Scottish Southern Uplands, which were subjected to the same exhumation episodes, although, the amount of exhumation varied between the localities. This is evident from the range of AFT ages (˜60 to ˜200 Ma) and variable thermal histories showing either strong, moderate and no support for a rapid cooling event at ˜60 Ma. Different apatite size and fragment geometry were analysed in order to maximise age dispersion. In general, the age dispersion increases with increasing AFT age (from 47% to 127%), consistent with the prediction from the fragmentation model. Thermal histories obtained using Helfrag were compared with those obtained by standard codes based on the spherical approximation. In one case, the Helfrag model was capable of resolving the higher complexity of the thermal history of the rock, constraining several heating/cooling events that are not predicted by the standard models, but are in good agreement with the regional geology. In other cases, the thermal histories are similar for both Helfrag and standard models and the age predictions for the Helfrag are only slightly better than for standard model, implying that the grain size has the dominant role in generating the age dispersion. Rather than suggesting that grain size is the predominant factor in controlling age dispersion in all data sets, our results may be linked to the actual size of the picked grains; for grain widths smaller than 100 μm, the He profile within the crystal may not be differentiated enough to produce a dispersion measureable outside the uncertainty associated with the age. It is also easier for long-thin and short-thick than long-thick and short-thin grains to be preserved; this minimises the age dispersion that can be generated from fragmentation. We suggest, that in order to obtain valuable information from both fragmentation and grain size >20 large (width >100 μm) grain fragments of variable length have to be analyzed, together with a few smaller grains. Our results point to a strategy that favours multiple single-grain AHe ages determinations on carefully selected samples, with good quality apatite crystals of variable dimensions rather than fewer determinations on many samples. [1] Brown, R. et al. 2013.Geochim. Cosmochim. Acta.122, 478-497 [2] Beucher, R. et al. 2013.Geochim. Cosmochim. Acta. 120, 395-416.

Inert gases in a terra sample - Measurements in six grain-size fractions and two single particles from Lunar 20.

NASA Technical Reports Server (NTRS)

Heymann, D.; Lakatos, S.; Walton, J. R.

1973-01-01

Review of the results of inert gas measurements performed on six grain-size fractions and two single particles from four samples of Luna 20 material. Presented and discussed data include the inert gas contents, element and isotope systematics, radiation ages, and Ar-36/Ar-40 systematics.

XRD-based 40Ar/39Ar age correction for fine-grained illite, with application to folded carbonates in the Monterrey Salient (northern Mexico)

NASA Astrophysics Data System (ADS)

Fitz-Díaz, Elisa; Hall, Chris M.; van der Pluijm, Ben A.

2016-05-01

Due to their minute size, 40Ar/39Ar analysis of illite faces significant analytical challenges, including mineral characterization and, especially, effects of grain size and crystallography on 39Ar recoil. Quantifying the effects of 39Ar recoil requires the use of sample vacuum encapsulation during irradiation, which permits the measurement of the fraction of recoiled 39Ar as well as the 39Ar and 40Ar∗ retained within illite crystals that are released during step heating. Total-Gas Ages (TGA) are calculated by using both recoiled and retained argon, which is functionally equivalent to K-Ar ages, while Retention Ages (RA) only involve retained Ar in the crystal. Natural applications have shown that TGA fits stratigraphic constraints of geological processes when the average illite crystallite thickness (ICT) is smaller than 10 nm, and that RA matches these constraints for ICTs larger than 50 nm. We propose a new age correction method that takes into account the average ICT and corresponding recoiled 39Ar for a sample, with X-ray Corrected Ages (XCA) lying between Total-Gas and Retention Ages depending on ICT. This correction is particularly useful in samples containing authigenic illite formed in the anchizone, with typical ICT values between 10 and 50 nm. In three samples containing authigenic illite from Cretaceous carbonates in the Monterrey Salient in northern Mexico, there is a range in TGAs among the different size-fractions of 46-49, 36-43 and 40-52 Ma, while RAs range from 54-64, 47-52 and 53-54 Ma, respectively. XCA calculations produce tighter age ranges for these samples of 52.5-56, 45.5-48.5 and 49-52.5 Ma, respectively. In an apparent age vs ICT or %2M 1illite plot, authigenic illite grains show a slope that is in general slightly positive for TGA, slightly negative for RA, but close to zero for XCA, with thinner crystallites showing more dispersion than thicker ones. In order to test if dispersion is due to a different formation history or the result of retention capability, degassing spectra were modeled for site XCA averages and overall XCA average. Modeling shows that local site age average best match the measured spectra, instead of a global average age, indicating that illite growth reflects local deformation, and is not the result of regional metamorphism. Modeling also shows that Ar-degassing spectra are very sensitive to grain size, such that age interpretation based on Ar-plateaus is meaningless for most fine-grained clays.

Whole Brain Size and General Mental Ability: A Review

PubMed Central

Rushton, J. Philippe; Ankney, C. Davison

2009-01-01

We review the literature on the relation between whole brain size and general mental ability (GMA) both within and between species. Among humans, in 28 samples using brain imaging techniques, the mean brain size/GMA correlation is 0.40 (N = 1,389; p < 10−10); in 59 samples using external head size measures it is 0.20 (N = 63,405; p < 10−10). In 6 samples using the method of correlated vectors to distill g, the general factor of mental ability, the mean r is 0.63. We also describe the brain size/GMA correlations with age, socioeconomic position, sex, and ancestral population groups, which also provide information about brain–behavior relationships. Finally, we examine brain size and mental ability from an evolutionary and behavior genetic perspective. PMID:19283594

Forestry inventory based on multistage sampling with probability proportional to size

NASA Technical Reports Server (NTRS)

Lee, D. C. L.; Hernandez, P., Jr.; Shimabukuro, Y. E.

1983-01-01

A multistage sampling technique, with probability proportional to size, is developed for a forest volume inventory using remote sensing data. The LANDSAT data, Panchromatic aerial photographs, and field data are collected. Based on age and homogeneity, pine and eucalyptus classes are identified. Selection of tertiary sampling units is made through aerial photographs to minimize field work. The sampling errors for eucalyptus and pine ranged from 8.34 to 21.89 percent and from 7.18 to 8.60 percent, respectively.

Pediatric anthropometrics are inconsistent with current guidelines for assessing rider fit on all-terrain vehicles.

PubMed

Bernard, Andrew C; Mullineaux, David R; Auxier, James T; Forman, Jennifer L; Shapiro, Robert; Pienkowski, David

2010-07-01

This study sought to establish objective anthropometric measures of fit or misfit for young riders on adult and youth-sized all-terrain vehicles and use these metrics to test the unproved historical reasoning that age alone is a sufficient measure of rider-ATV fit. Male children (6-11 years, n=8; and 12-15 years, n=11) were selected by convenience sampling. Rider-ATV fit was quantified by five measures adapted from published recommendations: (1) standing-seat clearance, (2) hand size, (3) foot vs. foot-brake position, (4) elbow angle, and (5) handlebar-to-knee distance. Youths aged 12-15 years fit the adult-sized ATV better than the ATV Safety Institute recommended age-appropriate youth model (63% of subjects fit all 5 measures on adult-sized ATV vs. 20% on youth-sized ATV). Youths aged 6-11 years fit poorly on ATVs of both sizes (0% fit all 5 parameters on the adult-sized ATV vs 12% on the youth-sized ATV). The ATV Safety Institute recommends rider-ATV fit according to age and engine displacement, but no objective data linking age or anthropometrics with ATV engine or frame size has been previously published. Age alone is a poor predictor of rider-ATV fit; the five metrics used offer an improvement compared to current recommendations. Copyright 2010 Elsevier Ltd. All rights reserved.

Influence of Sample Size of Polymer Materials on Aging Characteristics in the Salt Fog Test

NASA Astrophysics Data System (ADS)

Otsubo, Masahisa; Anami, Naoya; Yamashita, Seiji; Honda, Chikahisa; Takenouchi, Osamu; Hashimoto, Yousuke

Polymer insulators have been used in worldwide because of some superior properties; light weight, high mechanical strength, good hydrophobicity etc., as compared with porcelain insulators. In this paper, effect of sample size on the aging characteristics in the salt fog test is examined. Leakage current was measured by using 100 MHz AD board or 100 MHz digital oscilloscope and separated three components as conductive current, corona discharge current and dry band arc discharge current by using FFT and the current differential method newly proposed. Each component cumulative charge was estimated automatically by a personal computer. As the results, when the sample size increased under the same average applied electric field, the peak values of leakage current and each component current increased. Especially, the cumulative charges and the arc discharge length of dry band arc discharge increased remarkably with the increase of gap length.

Size and modal analyses of fines and ultrafines from some Apollo 17 samples

NASA Technical Reports Server (NTRS)

Greene, G. M.; King, D. T., Jr.; Banholzer, G. S., Jr.; King, E. A.

1975-01-01

Scanning electron and optical microscopy techniques have been used to determine the grain-size frequency distributions and morphology-based modal analyses of fine and ultrafine fractions of some Apollo 17 regolith samples. There are significant and large differences between the grain-size frequency distributions of the less than 10-micron size fraction of Apollo 17 samples, but there are no clear relations to the local geologic setting from which individual samples have been collected. This may be due to effective lateral mixing of regolith particles in this size range by micrometeoroid impacts. None of the properties of the frequency distributions support the idea of selective transport of any fine grain-size fraction, as has been proposed by other workers. All of the particle types found in the coarser size fractions also occur in the less than 10-micron particles. In the size range from 105 to 10 microns there is a strong tendency for the percentage of regularly shaped glass to increase as the graphic mean grain size of the less than 1-mm size fraction decreases, both probably being controlled by exposure age.

Behavioral and Emotional Problems Reported by Parents of Children Ages 6 to 16 in 31 Societies

ERIC Educational Resources Information Center

Rescorla, Leslie; Achenbach, Thomas; Ivanova, Masha Y.; Dumenci, Levent; Almqvist, Fredrik; Bilenberg, Niels; Bird, Hector; Chen, Wei; Dobrean, Anca; Dopfner, Manfred; Erol, Nese; Fombonne, Eric; Fonseca, Antonio; Frigerio, Alessandra; Grietens, Hans; Hannesdottir, Helga; Kanbayashi, Yasuko; Lambert, Michael; Larsson, Bo; Leung, Patrick; Liu, Xianchen; Minaei, Asghar; Mulatu, Mesfin S.; Novik, Torunn S.; Oh, Kyung-Ja; Roussos, Alexandra; Sawyer, Michael; Simsek, Zeynep; Steinhausen, Hans-Christoph; Weintraub, Sheila; Weisz, John; Metzke, Christa Winkler; Wolanczyk, Tomasz; Yang, Hao-Jan; Zilber, Nelly; Zukauskiene, Rita; Verhulst, Frank

2007-01-01

This study compared parents' ratings of behavioral and emotional problems on the "Child Behavior Checklist" (Achenbach, 1991; Achenbach & Rescorla, 2001) for general population samples of children ages 6 to 16 from 31 societies (N = 55,508). Effect sizes for society ranged from 0.03 to 0.14. Effect sizes for gender were less than or…

Simulation analyses of space use: Home range estimates, variability, and sample size

USGS Publications Warehouse

Bekoff, Marc; Mech, L. David

1984-01-01

Simulations of space use by animals were run to determine the relationship among home range area estimates, variability, and sample size (number of locations). As sample size increased, home range size increased asymptotically, whereas variability decreased among mean home range area estimates generated by multiple simulations for the same sample size. Our results suggest that field workers should ascertain between 100 and 200 locations in order to estimate reliably home range area. In some cases, this suggested guideline is higher than values found in the few published studies in which the relationship between home range area and number of locations is addressed. Sampling differences for small species occupying relatively small home ranges indicate that fewer locations may be sufficient to allow for a reliable estimate of home range. Intraspecific variability in social status (group member, loner, resident, transient), age, sex, reproductive condition, and food resources also have to be considered, as do season, habitat, and differences in sampling and analytical methods. Comparative data still are needed.

A new study of shower age distribution in near vertical showers by EAS air shower array

NASA Technical Reports Server (NTRS)

Chaudhuri, N.; Basak, D. K.; Goswami, G. C.; Ghosh, B.

1984-01-01

The air shower array has been developed since it started operation in 1931. The array covering an area of 900 sq m now incorporates 21 particle density sampling detectors around two muon magnetic spectrographs. The air showers are detected in the size range 10 to the 4th power to 10 to the 6th power particles. A total of 11000 showers has so far been detected. Average values of shower age have been obtained in various shower size ranges to study the dependence of shower age on shower size. The core distance dependence of shower age parameter has also been analyzed for presentation.

Alterations of intrinsic tongue muscle properties with aging.

PubMed

Cullins, Miranda J; Connor, Nadine P

2017-12-01

Age-related decline in the intrinsic lingual musculature could contribute to swallowing disorders, yet the effects of age on these muscles is unknown. We hypothesized there is reduced muscle fiber size and shifts to slower myosin heavy chain (MyHC) fiber types with age. Intrinsic lingual muscles were sampled from 8 young adult (9 months) and 8 old (32 months) Fischer 344/Brown Norway rats. Fiber size and MyHC were determined by fluorescent immunohistochemistry. Age was associated with a reduced number of rapidly contracting muscle fibers, and more slowly contracting fibers. Decreased fiber size was found only in the transverse and verticalis muscles. Shifts in muscle composition from faster to slower MyHC fiber types may contribute to age-related changes in swallowing duration. Decreasing muscle fiber size in the protrusive transverse and verticalis muscles may contribute to reductions in maximum isometric tongue pressure found with age. Differences among regions and muscles may be associated with different functional demands. Muscle Nerve 56: E119-E125, 2017. © 2017 Wiley Periodicals, Inc.

The Role of Quenching Time in the Evolution of the Mass-size Relation of Passive Galaxies from the Wisp Survey

NASA Astrophysics Data System (ADS)

Zanella, A.; Scarlata, C.; Corsini, E. M.; Bedregal, A. G.; Dalla Bontà, E.; Atek, H.; Bunker, A. J.; . Colbert, J.; Dai, Y. S.; Henry, A.; Malkan, M.; Martin, C.; Rafelski, M.; Rutkowski, M. J.; Siana, B.; Teplitz, H.

2016-06-01

We analyze how passive galaxies at z ˜ 1.5 populate the mass-size plane as a function of their stellar age, to understand if the observed size growth with time can be explained with the appearance of larger quenched galaxies at lower redshift. We use a sample of 32 passive galaxies extracted from the Wide Field Camera 3 Infrared Spectroscopic Parallel (WISP) survey with spectroscopic redshift 1.3 ≲ z ≲ 2.05, specific star formation rates lower than 0.01 Gyr-1, and stellar masses above 4.5 × 1010 M ⊙. All galaxies have spectrally determined stellar ages from fitting of their rest-frame optical spectra and photometry with stellar population models. When dividing our sample into young (age ≤2.1 Gyr) and old (age >2.1 Gyr) galaxies we do not find a significant trend in the distributions of the difference between the observed radius and that predicted by the mass-size relation. This result indicates that the relation between the galaxy age and its distance from the mass-size relation, if it exists, is rather shallow, with a slope α ≳ -0.6. At face value, this finding suggests that multiple dry and/or wet minor mergers, rather than the appearance of newly quenched galaxies, are mainly responsible for the observed time evolution of the mass-size relation in passive galaxies. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Measuring Successful Aging in Southern Black Older Adults

ERIC Educational Resources Information Center

Troutman, Meredith; Nies, Mary A.; Bentley, Monica

2011-01-01

With the growing size of the population of aging Black individuals, it is important to understand successful aging in this group. This study, therefore, piloted the Successful Aging Inventory (SAI) with a convenience sample of Black older adults. Participants completed a demographic form, the SAI, Purpose in Life Test, Life Satisfaction…

Size at emergence improves accuracy of age estimates in forensically-useful beetle Creophilus maxillosus L. (Staphylinidae).

PubMed

Matuszewski, Szymon; Frątczak-Łagiewska, Katarzyna

2018-02-05

Insects colonizing human or animal cadavers may be used to estimate post-mortem interval (PMI) usually by aging larvae or pupae sampled on a crime scene. The accuracy of insect age estimates in a forensic context is reduced by large intraspecific variation in insect development time. Here we test the concept that insect size at emergence may be used to predict insect physiological age and accordingly to improve the accuracy of age estimates in forensic entomology. Using results of laboratory study on development of forensically-useful beetle Creophilus maxillosus (Linnaeus, 1758) (Staphylinidae) we demonstrate that its physiological age at emergence [i.e. thermal summation value (K) needed for emergence] fall with an increase of beetle size. In the validation study it was found that K estimated based on the adult insect size was significantly closer to the true K as compared to K from the general thermal summation model. Using beetle length at emergence as a predictor variable and male or female specific model regressing K against beetle length gave the most accurate predictions of age. These results demonstrate that size of C. maxillosus at emergence improves accuracy of age estimates in a forensic context.

Grain Growth and Precipitation Behavior of Iridium Alloy DOP-26 During Long Term Aging

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

Pierce, Dean T.; Muralidharan, Govindarajan; Fox, Ethan E.

The influence of long term aging on grain growth and precipitate sizes and spatial distribution in iridium alloy DOP-26 was studied. Samples of DOP-26 were fabricated using the new process, recrystallized for 1 hour (h) at 1375 C, then aged at either 1300, 1400, or 1500 C for times ranging from 50 to 10,000 h. Grain size measurements (vertical and horizontal mean linear intercept and horizontal and vertical projection) and analyses of iridium-thorium precipitates (size and spacing) were made on the longitudinal, transverse, and rolling surfaces of the as-recrystallized and aged specimens from which the two-dimensional spatial distribution and meanmore » sizes of the precipitates were obtained. The results obtained from this study are intended to provide input to grain growth models.« less

Nutrition labeling and value size pricing at fast-food restaurants: a consumer perspective.

PubMed

O'Dougherty, Maureen; Harnack, Lisa J; French, Simone A; Story, Mary; Oakes, J Michael; Jeffery, Robert W

2006-01-01

This pilot study examined nutrition-related attitudes that may affect food choices at fast-food restaurants, including consumer attitudes toward nutrition labeling of fast foods and elimination of value size pricing. A convenience sample of 79 fast-food restaurant patrons aged 16 and above (78.5% white, 55% female, mean age 41.2 [17.1]) selected meals from fast-food restaurant menus that varied as to whether nutrition information was provided and value pricing included and completed a survey and interview on nutrition-related attitudes. Only 57.9% of participants rated nutrition as important when buying fast food. Almost two thirds (62%) supported a law requiring nutrition labeling on restaurant menus. One third (34%) supported a law requiring restaurants to offer lower prices on smaller instead of bigger-sized portions. This convenience sample of fast-food patrons supported nutrition labels on menus. More research is needed with larger samples on whether point-of-purchase nutrition labeling at fast-food restaurants raises perceived importance of nutrition when eating out.

The social class gradient in health in Spain and the health status of the Spanish Roma.

PubMed

La Parra Casado, Daniel; Gil González, Diana; de la Torre Esteve, María

2016-10-01

To determine the social class gradient in health in general Spain population and the health status of the Spanish Roma. The National Health Survey of Spanish Roma 2006 (sample size = 993 people; average age: 33.6 years; 53.1% women) and the National Health Surveys for Spain 2003 (sample size: 21,650 people; average age: 45.5 years; 51.2% women) and 2006 (sample size: 29,478 people; average age: 46 years; 50.7% women) are compared. Several indicators were chosen: self-perceived health, activity limitation, chronic diseases, hearing and sight problems, caries, and obesity. Analysis was based on age-standardised rates and logistic regression models. According to most indicators, Roma's health is worse than that of social class IV-V (manual workers). Some indicators show a remarkable difference between Roma and social class IV-V: experiencing three or more health problems, sight problems, and caries, in both sexes, and hearing problems and obesity, in women. Roma people are placed on an extreme position on the social gradient in health, a situation of extreme health inequality.

Distribution of molar mass and branching index of natural rubber from Hevea brasiliensis trees of different age by size exclusion chromatography coupled with online viscometry.

PubMed

Phan, T N; Lan, N T; Nga, N T

2004-05-01

Natural rubber from hevea brasiliensis trees (Thailand, RRIM 600 clone) of different age (8, 20, and 35 years) were characterized by size exclusion chromatography coupled with online viscometry according to their distribution of molar mass and branching index at a temperature of 70 degrees C using cyclohexane as solvent. Washing with an aqueous solution of sodium dodecylsulfate and subsequent saponification purified the natural rubber samples. With this procedure physical branching points caused by phospholipids, proteins and hydrophobic terminal units, mainly fatty acids, of the natural rubber (cis-1,4-polyisoprene) molecule, could be removed leading to completely soluble polymer samples. All samples investigated possess a very broad (10 to 50,000 kg/mol) and distinct bimodal molar mass distribution. With increasing age the peak area in the low molar mass region decreases favoring the peak area in the high molar mass region. By plotting the branching index as a function of the both, the molar mass and the age of the trees.

Long‐term trends in fall age ratios of black brant

USGS Publications Warehouse

Ward, David H.; Amundson, Courtney L.; Stehn, Robert A.; Dau, Christian P.

2018-01-01

Accurate estimates of the age composition of populations can inform past reproductive success and future population trajectories. We examined fall age ratios (juveniles:total birds) of black brant (Branta bernicla nigricans; brant) staging at Izembek National Wildlife Refuge near the tip of the Alaska Peninsula, southwest Alaska, USA, 1963 to 2015. We also investigated variation in fall age ratios associated with sampling location, an index of flock size, survey effort, day of season, observer, survey platform (boat‐ or land‐based) and tide stage. We analyzed data using logistic regression models implemented in a Bayesian framework. Mean predicted fall age ratio controlling for survey effort, day of year, and temporal and spatial variation was 0.24 (95% CL = 0.23, 0.25). Overall trend in age ratios was −0.6% per year (95% CL = −1.3%, 0.2%), resulting in an approximate 26% decline in the proportion of juveniles over the study period. We found evidence for variation across a range of variables implying that juveniles are not randomly distributed in space and time within Izembek Lagoon. Age ratios varied by location within the study area and were highly variable among years. They decreased with the number of birds aged (an index of flock size) and increased throughout September before leveling off in early October and declining in late October. Age ratios were similar among tide stages and observers and were lower during boat‐based (offshore) than land‐based (nearshore) surveys. Our results indicate surveys should be conducted annually during early to mid‐October to ensure the entire population is present and available for sampling, and throughout Izembek Lagoon to account for spatiotemporal variation in age ratios. Sampling should include a wide range of flock sizes representative of their distribution and occur in flocks located near and off shore. Further research evaluating the cause of declining age ratios in the fall population is necessary to inform management and predict long‐term population dynamics of brant.

Sexual dimorphism in human cranial trait scores: effects of population, age, and body size.

PubMed

Garvin, Heather M; Sholts, Sabrina B; Mosca, Laurel A

2014-06-01

Sex estimation from the skull is commonly performed by physical and forensic anthropologists using a five-trait scoring system developed by Walker. Despite the popularity of this method, validation studies evaluating its accuracy across a variety of samples are lacking. Furthermore, it remains unclear what other intrinsic or extrinsic variables are related to the expression of these traits. In this study, cranial trait scores and postcranial measurements were collected from four diverse population groups (U.S. Whites, U.S. Blacks, medieval Nubians, and Arikara Native Americans) following Walker's protocols (total n = 499). Univariate and multivariate analyses were utilized to evaluate the accuracy of these traits in sex estimation, and to test for the effects of population, age, and body size on trait expressions. Results revealed significant effects of population on all trait scores. Sample-specific correct sex classification rates ranged from 74% to 94%, with an overall accuracy of 85% for the pooled sample. Classification performance varied among the traits (best for glabella and mastoid scores and worst for nuchal scores). Furthermore, correlations between traits were weak or nonsignificant, suggesting that different factors may influence individual traits. Some traits displayed correlations with age and/or postcranial size that were significant but weak, and within-population analyses did not reveal any consistent relationships between these traits across all groups. These results indicate that neither age nor body size plays a large role in trait expression, and thus does not need to be incorporated into sex estimation methods. Copyright © 2014 Wiley Periodicals, Inc.

Grey Tienshan Urumqi Glacier No.1 and light-absorbing impurities.

PubMed

Ming, Jing; Xiao, Cunde; Wang, Feiteng; Li, Zhongqin; Li, Yamin

2016-05-01

The Tienshan Urumqi Glacier No.1 (TUG1) usually shows "grey" surfaces in summers. Besides known regional warming, what should be responsible for largely reducing its surface albedo and making it look "grey"? A field campaign was conducted on the TUG1 on a selected cloud-free day of 2013 after a snow fall at night. Fresh and aged snow samples were collected in the field, and snow densities, grain sizes, and spectral reflectances were measured. Light-absorbing impurities (LAIs) including black carbon (BC) and dust, and number concentrations and sizes of the insoluble particles (IPs) in the samples were measured in the laboratory. High temperatures in summer probably enhanced the snow ageing. During the snow ageing process, the snow density varied from 243 to 458 kg m(-3), associated with the snow grain size varying from 290 to 2500 μm. The concentrations of LAIs in aged snow were significantly higher than those in fresh snow. Dust and BC varied from 16 ppm and 25 ppb in fresh snow to 1507 ppm and 1738 ppb in aged snow, respectively. Large albedo difference between the fresh and aged snow suggests a consequent forcing of 180 W m(-2). Simulations under scenarios show that snow ageing, BC, and dust were responsible for 44, 25, and 7 % of the albedo reduction in the accumulation zone, respectively.

X-ray studies of aluminum alloy of the Al-Mg-Si system subjected to SPD processing

NASA Astrophysics Data System (ADS)

Sitdikov, V. D.; Murashkin, M. Yu; Khasanov, M. R.; Kasatkin, I. A.; Chizhov, P. S.; Bobruk, E. V.

2014-08-01

Recently it has been established that during high pressure torsion dynamic aging takes place in aluminum Al-Mg-Si alloys resulting in formation of nanosized particles of strengthening phases in the aluminum matrix, which greatly improves the electrical conductivity and strength properties. In the present paper structural characterization of ultrafine-grained (UFG) samples of aluminum 6201 alloy produced by severe plastic deformation (SPD) was performed using X-ray diffraction analysis. As a result, structure features (lattice parameter, size of coherent scattering domains) after dynamic aging of UFG samples were determined. The size and distribution of second- phase particles in the Al matrix were assessed with regard to HPT regimes. Impact of the size and distribution of the formed secondary phases on the strength, ductility and electrical conductivity is discussed.

Infraocclusion: Dental development and associated dental variations in singletons and twins.

PubMed

Odeh, Ruba; Townsend, Grant; Mihailidis, Suzanna; Lähdesmäki, Raija; Hughes, Toby; Brook, Alan

2015-09-01

The aim of this study was to investigate the prevalence of selected dental variations in association with infraocclusion, as well as determining the effects of infraocclusion on dental development and tooth size, in singletons and twins. Two samples were analysed. The first sample comprised 1454 panoramic radiographs of singleton boys and girls aged 8-11 years. The second sample comprised dental models of 202 pairs of monozygotic and dizygotic twins aged 8-11 years. Adobe Photoshop CS5 was used to construct reference lines and measure the extent of infraocclusion (in mm) of primary molars on the panoramic radiographs and on 2D images obtained from the dental models. The panoramic radiographs were examined for the presence of selected dental variations and to assess dental development following the Demirjian and Willems systems. The twins' dental models were measured to assess mesiodistal crown widths. In the singleton sample there was a significant association of canines in an altered position during eruption and the lateral incisor complex (agenesis and/or small tooth size) with infraocclusion (P<0.001), but there was no significant association between infraocclusion and agenesis of premolars. Dental age assessment revealed that dental development was delayed in individuals with infraocclusion compared to controls. The primary mandibular canines were significantly smaller in size in the infraoccluded group (P<0.05). The presence of other dental variations in association with infraocclusion, as well as delayed dental development and reduced tooth size, suggests the presence of a pleiotropic effect. The underlying aetiological factors may be genetic and/or epigenetic. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of temperature and aging time on HA synthesized by the hydrothermal method.

PubMed

Kothapalli, C R; Wei, M; Legeros, R Z; Shaw, M T

2005-05-01

The influence of temperature and aging time on the morphology and mechanical properties of nano-sized hydroxyapatite (HA) synthesized by a hydrothermal method is reported here. The pre-mixed reactants were poured into a stirred autoclave and reacted at temperatures between 25-250 degrees C for 2-10 h. HA powders thus obtained were examined using X-ray diffraction (XRD), high-resolution field emission scanning electron microscopy (FESEM) and a particle size analyzer. It was found that the aspect ratio of the particles increased with the reaction temperature. The length of the HA particles increased with the reaction temperature below 170 degrees C, but it decreased when the temperature was raised above 170 degrees C. The agglomerates of HA particles were formed during synthesis, and their sizes were strongly dependent on reaction temperatures. As the reaction temperature increased, the agglomerate size decreased (p = 0.008). The density of the discs pressed from these samples reached 85-90% of the theoretical density after sintering at 1200 degrees C for 1 h. No decomposition to other calcium phosphates was detected at this sintering temperature. A correlation existed (p = 0.05) between the agglomerate sizes of HA particles synthesized at various conditions and their sintered densities. With the increase of the agglomerate size, the sintered density of the HA compact decreased. It was found that both the sintered density and flexural strength increased with increasing aging time and reaction temperature. A maximum flexural strength of 78 MPa was observed for the samples synthesized at 170 degrees C for 5 h with the predicted average at these conditions being 65 MPa. These samples attained an average sintered density of 88%.

Sample size estimation for alternating logistic regressions analysis of multilevel randomized community trials of under-age drinking.

PubMed

Reboussin, Beth A; Preisser, John S; Song, Eun-Young; Wolfson, Mark

2012-07-01

Under-age drinking is an enormous public health issue in the USA. Evidence that community level structures may impact on under-age drinking has led to a proliferation of efforts to change the environment surrounding the use of alcohol. Although the focus of these efforts is to reduce drinking by individual youths, environmental interventions are typically implemented at the community level with entire communities randomized to the same intervention condition. A distinct feature of these trials is the tendency of the behaviours of individuals residing in the same community to be more alike than that of others residing in different communities, which is herein called 'clustering'. Statistical analyses and sample size calculations must account for this clustering to avoid type I errors and to ensure an appropriately powered trial. Clustering itself may also be of scientific interest. We consider the alternating logistic regressions procedure within the population-averaged modelling framework to estimate the effect of a law enforcement intervention on the prevalence of under-age drinking behaviours while modelling the clustering at multiple levels, e.g. within communities and within neighbourhoods nested within communities, by using pairwise odds ratios. We then derive sample size formulae for estimating intervention effects when planning a post-test-only or repeated cross-sectional community-randomized trial using the alternating logistic regressions procedure.

One Size Fits All? Applying Theoretical Predictions about Age and Emotional Experience to People with Functional Disabilities

PubMed Central

Piazza, Jennifer R.; Charles, Susan T.; Luong, Gloria; Almeida, David M.

2015-01-01

The current study examined whether commonly observed age differences in affective experience among community samples of healthy adults would generalize to a group of adults who live with significant functional disability. Age differences in daily affect and affective reactivity to daily stressors among a sample of participants with spinal cord injury were compared to a non-injured sample. Results revealed that patterns of affective experience varied by sample. Among non-injured adults, older age was associated with lower levels of daily negative affect (NA), higher levels of daily positive affect (PA), and less negative affective reactivity in response to daily stressors. In contrast, among participants with spinal cord injury, no age differences emerged. Findings, which support the model of Strength and Vulnerability Integration (SAVI), underscore the importance of taking life context into account when predicting age differences in affective well-being. PMID:26322552

Effect of retrogression duration on the grain boundary microstructure and microchemistry of AA7010

NASA Astrophysics Data System (ADS)

Nandana, M. S.; Bhat, K. Udaya; Manjunatha, C. M.

2018-04-01

The paper presents the microstructural characterization of the aluminium alloy 7010 in retrogression and re- ageing (RRA) condition by using Transmission Electron Microscope (TEM). The grain boundary microstructure is analyzed with the focus on variation of GBP's (grain boundary precipitate) size and PFZ (precipitate free zone) size during retrogression performed at 200 °C for duration of 10-60 min. The microchemistry of the GBP's is analyzed by using TEM-EDS (Energy Dispersive X-ray spectroscopy). The results reveal the coarsening of discrete GBP's along with enrichment of the Cu in them. The average size of the GBP's in RRA treated sample vary from 30 nm during 10 min of retrogression to 59 nm at 60 min of retrogression. The PFZ size varied from 35 nm to 51 nm for 10 min and 60 min of retrogression time, respectively. The Cu content of the GBP's increased from 3.54 wt% for 10 min of retrogression to 5.27 wt% for 60 min of retrogression and re-aged sample.

Age differences in the use of serving size information on food labels: numeracy or attention?

PubMed

Miller, Lisa M Soederberg; Applegate, Elizabeth; Beckett, Laurel A; Wilson, Machelle D; Gibson, Tanja N

2017-04-01

The ability to use serving size information on food labels is important for managing age-related chronic conditions such as diabetes, obesity and cancer. Past research suggests that older adults are at risk for failing to accurately use this portion of the food label due to numeracy skills. However, the extent to which older adults pay attention to serving size information on packages is unclear. We compared the effects of numeracy and attention on age differences in accurate use of serving size information while individuals evaluated product healthfulness. Accuracy and attention were assessed across two tasks in which participants compared nutrition labels of two products to determine which was more healthful if they were to consume the entire package. Participants' eye movements were monitored as a measure of attention while they compared two products presented side-by-side on a computer screen. Numeracy as well as food label habits and nutrition knowledge were assessed using questionnaires. Sacramento area, California, USA, 2013-2014. Stratified sample of 358 adults, aged 20-78 years. Accuracy declined with age among those older adults who paid less attention to serving size information. Although numeracy, nutrition knowledge and self-reported food label use supported accuracy, these factors did not influence age differences in accuracy. The data suggest that older adults are less accurate than younger adults in their use of serving size information. Age differences appear to be more related to lack of attention to serving size information than to numeracy skills.

Improving size estimates of open animal populations by incorporating information on age

USGS Publications Warehouse

Manly, Bryan F.J.; McDonald, Trent L.; Amstrup, Steven C.; Regehr, Eric V.

2003-01-01

Around the world, a great deal of effort is expended each year to estimate the sizes of wild animal populations. Unfortunately, population size has proven to be one of the most intractable parameters to estimate. The capture-recapture estimation models most commonly used (of the Jolly-Seber type) are complicated and require numerous, sometimes questionable, assumptions. The derived estimates usually have large variances and lack consistency over time. In capture–recapture studies of long-lived animals, the ages of captured animals can often be determined with great accuracy and relative ease. We show how to incorporate age information into size estimates for open populations, where the size changes through births, deaths, immigration, and emigration. The proposed method allows more precise estimates of population size than the usual models, and it can provide these estimates from two sample occasions rather than the three usually required. Moreover, this method does not require specialized programs for capture-recapture data; researchers can derive their estimates using the logistic regression module in any standard statistical package.

Random vs. systematic sampling from administrative databases involving human subjects.

PubMed

Hagino, C; Lo, R J

1998-09-01

Two sampling techniques, simple random sampling (SRS) and systematic sampling (SS), were compared to determine whether they yield similar and accurate distributions for the following four factors: age, gender, geographic location and years in practice. Any point estimate within 7 yr or 7 percentage points of its reference standard (SRS or the entire data set, i.e., the target population) was considered "acceptably similar" to the reference standard. The sampling frame was from the entire membership database of the Canadian Chiropractic Association. The two sampling methods were tested using eight different sample sizes of n (50, 100, 150, 200, 250, 300, 500, 800). From the profile/characteristics, summaries of four known factors [gender, average age, number (%) of chiropractors in each province and years in practice], between- and within-methods chi 2 tests and unpaired t tests were performed to determine whether any of the differences [descriptively greater than 7% or 7 yr] were also statistically significant. The strengths of the agreements between the provincial distributions were quantified by calculating the percent agreements for each (provincial pairwise-comparison methods). Any percent agreement less than 70% was judged to be unacceptable. Our assessments of the two sampling methods (SRS and SS) for the different sample sizes tested suggest that SRS and SS yielded acceptably similar results. Both methods started to yield "correct" sample profiles at approximately the same sample size (n > 200). SS is not only convenient, it can be recommended for sampling from large databases in which the data are listed without any inherent order biases other than alphabetical listing by surname.

Moderating the Covariance Between Family Member’s Substance Use Behavior

PubMed Central

Eaves, Lindon J.; Neale, Michael C.

2014-01-01

Twin and family studies implicitly assume that the covariation between family members remains constant across differences in age between the members of the family. However, age-specificity in gene expression for shared environmental factors could generate higher correlations between family members who are more similar in age. Cohort effects (cohort × genotype or cohort × common environment) could have the same effects, and both potentially reduce effect sizes estimated in genome-wide association studies where the subjects are heterogeneous in age. In this paper we describe a model in which the covariance between twins and non-twin siblings is moderated as a function of age difference. We describe the details of the model and simulate data using a variety of different parameter values to demonstrate that model fitting returns unbiased parameter estimates. Power analyses are then conducted to estimate the sample sizes required to detect the effects of moderation in a design of twins and siblings. Finally, the model is applied to data on cigarette smoking. We find that (1) the model effectively recovers the simulated parameters, (2) the power is relatively low and therefore requires large sample sizes before small to moderate effect sizes can be found reliably, and (3) the genetic covariance between siblings for smoking behavior decays very rapidly. Result 3 implies that, e.g., genome-wide studies of smoking behavior that use individuals assessed at different ages, or belonging to different birth-year cohorts may have had substantially reduced power to detect effects of genotype on cigarette use. It also implies that significant special twin environmental effects can be explained by age-moderation in some cases. This effect likely contributes to the missing heritability paradox. PMID:24647834

Aged boreal biomass-burning aerosol size distributions from BORTAS 2011

NASA Astrophysics Data System (ADS)

Sakamoto, K. M.; Allan, J. D.; Coe, H.; Taylor, J. W.; Duck, T. J.; Pierce, J. R.

2015-02-01

Biomass-burning aerosols contribute to aerosol radiative forcing on the climate system. The magnitude of this effect is partially determined by aerosol size distributions, which are functions of source fire characteristics (e.g. fuel type, MCE) and in-plume microphysical processing. The uncertainties in biomass-burning emission number-size distributions in climate model inventories lead to uncertainties in the CCN (cloud condensation nuclei) concentrations and forcing estimates derived from these models. The BORTAS-B (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellite) measurement campaign was designed to sample boreal biomass-burning outflow over eastern Canada in the summer of 2011. Using these BORTAS-B data, we implement plume criteria to isolate the characteristic size distribution of aged biomass-burning emissions (aged ~ 1-2 days) from boreal wildfires in northwestern Ontario. The composite median size distribution yields a single dominant accumulation mode with Dpm = 230 nm (number-median diameter) and σ = 1.5, which are comparable to literature values of other aged plumes of a similar type. The organic aerosol enhancement ratios (ΔOA / ΔCO) along the path of Flight b622 show values of 0.09-0.17 μg m-3 ppbv-1 (parts per billion by volume) with no significant trend with distance from the source. This lack of enhancement ratio increase/decrease with distance suggests no detectable net OA (organic aerosol) production/evaporation within the aged plume over the sampling period (plume age: 1-2 days), though it does not preclude OA production/loss at earlier stages. A Lagrangian microphysical model was used to determine an estimate of the freshly emitted size distribution corresponding to the BORTAS-B aged size distributions. The model was restricted to coagulation and dilution processes based on the insignificant net OA production/evaporation derived from the ΔOA / ΔCO enhancement ratios. We estimate that the young-plume median diameter was in the range of 59-94 nm with modal widths in the range of 1.7-2.8 (the ranges are due to uncertainty in the entrainment rate). Thus, the size of the freshly emitted particles is relatively unconstrained due to the uncertainties in the plume dilution rates.

Growth in Head Size during Infancy: Implications for Sound Localization.

ERIC Educational Resources Information Center

Clifton, Rachel K.; And Others

1988-01-01

Compared head circumference and interaural distance in infants between birth and 22 weeks of age and in a small sample of preschool children and adults. Calculated changes in interaural time differences according to age. Found a large shift in distance. (SKC)

Exploring the age of intracranial aneurysms using carbon birth dating: preliminary results.

PubMed

Etminan, Nima; Dreier, Rita; Buchholz, Bruce A; Bruckner, Peter; Steiger, Hans-Jakob; Hänggi, Daniel; Macdonald, R Loch

2013-03-01

There is a controversy about the time span over which cerebral aneurysms develop. In particular, it is unknown whether collagen in ruptured aneurysms undergoes more rapid turnover than in unruptured aneurysms.(14)C birth dating of collagen could be used to address this question. Aneurysmal domes from patients undergoing surgical treatment for ruptured or unruptured aneurysms were excised. Aneurysmal collagen was isolated and purified after pepsin digestion. Collagen from mouse tendons served as controls. F(14)C levels in collagen were analyzed by accelerator mass spectrometry and correlated with patient age and aneurysm size. Analysis of 10 aneurysms from 9 patients (6 ruptured, 3 unruptured) revealed an average aneurysm collagen age of <5 years, generally irrespective of patient age and aneurysm size or rupture status. Interestingly, F(14)C levels correlated with patient age as well as aneurysm size in ruptured aneurysm collagen samples. Our preliminary data suggest that collagen extracted from intracranial aneurysms generally has a high turnover, associated with aneurysm size and patient age. The correlation of patient age and aneurysm F(14)C levels could explain models of aneurysm development. Although preliminary, our findings may have implications for the biological and structural stability of ruptured and unruptured intracranial aneurysms.

Molecular size and molecular size distribution affecting traditional balsamic vinegar aging.

PubMed

Falcone, Pasquale Massimiliano; Giudici, Paolo

2008-08-27

A first attempt at a semiquantitative study of molecular weight (MW) and molecular weight distribution (MWD) in cooked grape must and traditional balsamic vinegar (TBV) with increasing well-defined age was performed by high-performance liquid size exclusion chromatography (SEC) using dual detection, that is, differential refractive index (DRI) and absorbance (UV-vis) based detectors. With this aim, MW and MWD, including number- and weight-average MW and polydispersity, were determined with respect to a secondary standard and then analyzed. All investigated vinegar samples were recognized as compositionally and structurally heterogeneous blends of copolymers (melanoidins) spreading over a wide range of molecular sizes: the relative MW ranged from 2 to >2000 kDa. The extent of the polymerization reactions was in agreement with the TBV browning kinetics. MWD parameters varied asymptotically toward either upper or lower limits during aging, reflecting a nonequilibrium status of the balance between polymerization and depolymerization reactions in TBV. MWD parameters were proposed as potential aging markers of TBV.

When bigger is not better: selection against large size, high condition and fast growth in juvenile lemon sharks.

PubMed

Dibattista, J D; Feldheim, K A; Gruber, S H; Hendry, A P

2007-01-01

Selection acting on large marine vertebrates may be qualitatively different from that acting on terrestrial or freshwater organisms, but logistical constraints have thus far precluded selection estimates for the former. We overcame these constraints by exhaustively sampling and repeatedly recapturing individuals in six cohorts of juvenile lemon sharks (450 age-0 and 255 age-1 fish) at an enclosed nursery site (Bimini, Bahamas). Data on individual size, condition factor, growth rate and inter-annual survival were used to test the 'bigger is better', 'fatter is better' and 'faster is better' hypotheses of life-history theory. For age-0 sharks, selection on all measured traits was weak, and generally acted against large size and high condition. For age-1 sharks, selection was much stronger, and consistently acted against large size and fast growth. These results suggest that selective pressures at Bimini may be constraining the evolution of large size and fast growth, an observation that fits well with the observed small size and low growth rate of juveniles at this site. Our results support those of some other recent studies in suggesting that bigger/fatter/faster is not always better, and may often be worse.

Accounting for body size deviations when reporting bone mineral density variables in children.

PubMed

Webber, C E; Sala, A; Barr, R D

2009-01-01

In a child, bone mineral density (BMD) may differ from an age-expected normal value, not only because of the presence of disease, but also because of deviations of height or weight from population averages. Appropriate adjustment for body size deviations simplifies interpretation of BMD measurements. For children, a bone mineral density (BMD) measurement is normally expressed as a Z score. Interpretation is complicated when weight or height distinctly differ from age-matched children. We develop a procedure to allow for the influence of body size deviations upon measured BMD. We examined the relation between body size deviation and spine, hip and whole body BMD deviation in 179 normal children (91 girls). Expressions were developed that allowed derivation of an expected BMD based on age, gender and body size deviation. The difference between measured and expected BMD was expressed as a HAW score (Height-, Age-, Weight-adjusted score). In a second independent sample of 26 normal children (14 girls), measured spine, total femur and whole body BMD all fell within the same single normal range after accounting for age, gender and body size deviations. When traditional Z scores and HAW scores were compared in 154 children, 17.5% showed differences of more than 1 unit and such differences were associated with height and weight deviations. For almost 1 in 5 children, body size deviations influence BMD to an extent that could alter clinical management.

Factors Associated with the Performance and Cost-Effectiveness of Using Lymphatic Filariasis Transmission Assessment Surveys for Monitoring Soil-Transmitted Helminths: A Case Study in Kenya

PubMed Central

Smith, Jennifer L.; Sturrock, Hugh J. W.; Assefa, Liya; Nikolay, Birgit; Njenga, Sammy M.; Kihara, Jimmy; Mwandawiro, Charles S.; Brooker, Simon J.

2015-01-01

Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8–10 years of age to assess STH but suggest that key consideration is given to evaluation unit size. PMID:25487730

Is Political Activism on Social Media an initiator of Psychological Stress?

PubMed

Hisam, Aliya; Safoor, Iqra; Khurshid, Nawal; Aslam, Aakash; Zaid, Farhan; Muzaffar, Ayesha

2017-01-01

To find out the association of psychological stress with political activism on social networking sites (SNS) in adults. To find association of psychological stress and political activism with age, gender and occupational status. A descriptive cross-sectional study of 8 months (Aug 2014 to March 2015) was conducted on young adults between age group of 20-40 years of different universities of Rawalpindi, Pakistan. Closed ended standardized questionnaires (i.e. Cohen Perceived Stress-10) were distributed via non-probability convenient sampling among a total sample size of 237. Sample size was calculated using WHO sample size calculator and data was analyzed in STATA version 12. The mean age of participants was 21.06±1.425 years. Out of the 237 participants, 150 (63.3%) were males and 87 (36.7%) females. Regarding their occupation, 13 (51.9%) were military cadets, 8 (3.4%) were consultant, 47 (19.8%) medical officer, 3 (1.3%) PG students and 56 (23.6%) MBBS students. Significant association of occupation was established with both political activism and psychological stress (p=0.4 and p=0.002 respectively). Among 237 individuals, 91 (38.4%) were stressed out and 146 (61.6%) were not. Among whole sample, political activists on SNS were found to be 23 (9.7%). Out of these 23 individuals who were politically active, 15 (65.2%) were stressed out and 8 (34.7%) were not. A significant association between stress and political activism was established (p=0.005). Political activism via social networking sites is playing significant role on adult person's mental health in terms of stress among different occupation.

Adaptive significance of small body size: strength and motor performance of school children in Mexico and Papua New Guinea.

PubMed

Malina, R M; Little, B B; Shoup, R F; Buschang, P H

1987-08-01

The postulated superior functional efficiency in association with reduced body size under conditions of chronic protein-energy undernutrition was considered in school children from rural Mexico and coastal Papua New Guinea. Grip strength and three measures of motor performance were measured in cross-sectional samples of children 6-16 years of age from a rural agricultural community in Oaxaca, Mexico, and from the coastal community Pere on Manus Island, Papua New Guinea. The strength and performance of a mixed-longitudinal sample of well nourished children from Philadelphia was used as a reference. The Oaxaca and Pere children are significantly shorter and lighter and are not as strong as the well nourished children. Motor performances of Pere children compare favorably to those of the better-nourished Philadelphia children, whereas those of the Oaxaca children are poorer. Throwing performance is more variable. When expressed relative to body size, strength is similar in the three samples, but the running and jumping performances of Pere children per unit body size are better than the relative performances of Oaxaca and Philadelphia children. Throwing performance per unit body size is better in the undernourished children. The influence of age, stature, and weight on the performance of Oaxaca and Pere children is generally similar to that for well nourished children. These results suggest that the hypothesized adaptive significance of small body size for the functional efficiency of populations living under conditions of chronic undernutrition varies between populations and with performance tasks.

Size exclusion chromatography for analyses of fibroin in silk: optimization of sampling and separation conditions

NASA Astrophysics Data System (ADS)

Pawcenis, Dominika; Koperska, Monika A.; Milczarek, Jakub M.; Łojewski, Tomasz; Łojewska, Joanna

2014-02-01

A direct goal of this paper was to improve the methods of sample preparation and separation for analyses of fibroin polypeptide with the use of size exclusion chromatography (SEC). The motivation for the study arises from our interest in natural polymers included in historic textile and paper artifacts, and is a logical response to the urgent need for developing rationale-based methods for materials conservation. The first step is to develop a reliable analytical tool which would give insight into fibroin structure and its changes caused by both natural and artificial ageing. To investigate the influence of preparation conditions, two sets of artificially aged samples were prepared (with and without NaCl in sample solution) and measured by the means of SEC with multi angle laser light scattering detector. It was shown that dialysis of fibroin dissolved in LiBr solution allows removal of the salt which destroys stacks chromatographic columns and prevents reproducible analyses. Salt rich (NaCl) water solutions of fibroin improved the quality of chromatograms.

Age as a Risk Factor for Burnout Syndrome in Nursing Professionals: A Meta-Analytic Study.

PubMed

Gómez-Urquiza, José L; Vargas, Cristina; De la Fuente, Emilia I; Fernández-Castillo, Rafael; Cañadas-De la Fuente, Guillermo A

2017-04-01

Although past research has highlighted the possibility of a direct relationship between the age of nursing professionals and burnout syndrome, results have been far from conclusive. The aim of this study was to conduct a wider analysis of the influence of age on the three dimensions of burnout syndrome (emotional exhaustion, depersonalization, and personal accomplishment) in nurses. We performed a meta-analysis of 51 publications extracted from health sciences and psychology databases that fulfilled the inclusion criteria. There were 47 reports of information on emotional exhaustion in 50 samples, 39 reports on depersonalization for 42 samples, and 31 reports on personal accomplishment in 34 samples. The mean effect sizes indicated that younger age was a significant factor in the emotional exhaustion and depersonalization of nurses, although it was somewhat less influential in the dimension of personal accomplishment. Because of heterogeneity in the effect sizes, moderating variables that might explain the association between age and burnout were also analyzed. Gender, marital status, and study characteristics moderated the relationship between age and burnout and may be crucial for the identification of high-risk groups. More research is needed on other variables for which there were only a small number of studies. Identification of burnout risk factors will facilitate establishment of burnout prevention programs for nurses. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Bayesian Optimization for Neuroimaging Pre-processing in Brain Age Classification and Prediction

PubMed Central

Lancaster, Jenessa; Lorenz, Romy; Leech, Rob; Cole, James H.

2018-01-01

Neuroimaging-based age prediction using machine learning is proposed as a biomarker of brain aging, relating to cognitive performance, health outcomes and progression of neurodegenerative disease. However, even leading age-prediction algorithms contain measurement error, motivating efforts to improve experimental pipelines. T1-weighted MRI is commonly used for age prediction, and the pre-processing of these scans involves normalization to a common template and resampling to a common voxel size, followed by spatial smoothing. Resampling parameters are often selected arbitrarily. Here, we sought to improve brain-age prediction accuracy by optimizing resampling parameters using Bayesian optimization. Using data on N = 2003 healthy individuals (aged 16–90 years) we trained support vector machines to (i) distinguish between young (<22 years) and old (>50 years) brains (classification) and (ii) predict chronological age (regression). We also evaluated generalisability of the age-regression model to an independent dataset (CamCAN, N = 648, aged 18–88 years). Bayesian optimization was used to identify optimal voxel size and smoothing kernel size for each task. This procedure adaptively samples the parameter space to evaluate accuracy across a range of possible parameters, using independent sub-samples to iteratively assess different parameter combinations to arrive at optimal values. When distinguishing between young and old brains a classification accuracy of 88.1% was achieved, (optimal voxel size = 11.5 mm3, smoothing kernel = 2.3 mm). For predicting chronological age, a mean absolute error (MAE) of 5.08 years was achieved, (optimal voxel size = 3.73 mm3, smoothing kernel = 3.68 mm). This was compared to performance using default values of 1.5 mm3 and 4mm respectively, resulting in MAE = 5.48 years, though this 7.3% improvement was not statistically significant. When assessing generalisability, best performance was achieved when applying the entire Bayesian optimization framework to the new dataset, out-performing the parameters optimized for the initial training dataset. Our study outlines the proof-of-principle that neuroimaging models for brain-age prediction can use Bayesian optimization to derive case-specific pre-processing parameters. Our results suggest that different pre-processing parameters are selected when optimization is conducted in specific contexts. This potentially motivates use of optimization techniques at many different points during the experimental process, which may improve statistical sensitivity and reduce opportunities for experimenter-led bias. PMID:29483870

Molecular Subtypes of Indonesian Breast Carcinomas - Lack of Association with Patient Age and Tumor Size

PubMed Central

Rahmawati, Yeni; Setyawati, Yunita; Widodo, Irianiwati; Ghozali, Ahmad; Purnomosari, Dewajani

2018-01-01

Objective: Breast carcinoma (BC) is a heterogeneous disease that exhibits variation in biological behaviour, prognosis and response to therapy. Molecular classification is generally into Luminal A, Luminal B, HER2+ and triple negative/basal-like, depending on receptor characteristics. Clinical factors that determined the BC prognosis are age and tumor size. Since information on molecular subtypes of Indonesian BCs is limited, the present study was conducted, with attention to subtypes in relation to age and tumor size. Methods: A retrospective cross-sectional study of 247 paraffin-embedded samples of invasive BC from Dr. Sardjito General Hospital Yogyakarta in the year 2012- 2015 was performed. Immunohistochemical staining using anti- ER, PR, HER2, Ki-67 and CK 5/6 antibodies was applied to classify molecular subtypes. Associations with age and tumor size were analyzed using the Chi Square Test. Results: The Luminal A was the most common subtype of Indonesian BC (41.3%), followed by triple negative (25.5%), HER2 (19.4%) and luminal B (13.8%). Among the triple negative lesions, the basal-like subtype was more frequent than the non basal-like (58.8 % vs 41.2%). Luminal B accounted for the highest percentage of younger age cases (< 40 years old) while HER2+ was most common in older age (> 50 years old) patients. Triple negative/basal-like were commonly large in size. Age (p = 0.080) and tumor size (p = 0.462) were not significantly associated with molecular subtypes of BC. Conclusion: The most common molecular subtype of Indonesian BC is luminal A, followed by triple-negative, HER2+ and luminal B. The majority of triple-negative lesions are basal-like. There are no association between age and tumor size with molecular subtypes of Indonesian BCs. PMID:29373908

Molecular Subtypes of Indonesian Breast Carcinomas - Lack of Association with Patient Age and Tumor Size

PubMed

Rahmawati, Yeni; Setyawati, Yunita; Widodo, Irianiwati; Ghozali, Ahmad; Purnomosari, Dewajani

2018-01-27

Objective: Breast carcinoma (BC) is a heterogeneous disease that exhibits variation in biological behaviour, prognosis and response to therapy. Molecular classification is generally into Luminal A, Luminal B, HER2+ and triple negative/basal-like, depending on receptor characteristics. Clinical factors that determined the BC prognosis are age and tumor size. Since information on molecular subtypes of Indonesian BCs is limited, the present study was conducted, with attention to subtypes in relation to age and tumor size. Methods: A retrospective cross-sectional study of 247 paraffin-embedded samples of invasive BC from Dr. Sardjito General Hospital Yogyakarta in the year 2012- 2015 was performed. Immunohistochemical staining using anti- ER, PR, HER2, Ki-67 and CK 5/6 antibodies was applied to classify molecular subtypes. Associations with age and tumor size were analyzed using the Chi Square Test. Results: The Luminal A was the most common subtype of Indonesian BC (41.3%), followed by triple negative (25.5%), HER2 (19.4%) and luminal B (13.8%). Among the triple negative lesions, the basal-like subtype was more frequent than the non basal-like (58.8 % vs 41.2%). Luminal B accounted for the highest percentage of younger age cases (< 40 years old) while HER2+ was most common in older age (> 50 years old) patients. Triple negative/basal-like were commonly large in size. Age (p = 0.080) and tumor size (p = 0.462) were not significantly associated with molecular subtypes of BC. Conclusion: The most common molecular subtype of Indonesian BC is luminal A, followed by triple-negative, HER2+ and luminal B. The majority of triple-negative lesions are basal-like. There are no association between age and tumor size with molecular subtypes of Indonesian BCs. Creative Commons Attribution License

Body Size Estimation from Early to Middle Childhood: Stability of Underestimation, BMI, and Gender Effects.

PubMed

Steinsbekk, Silje; Klöckner, Christian A; Fildes, Alison; Kristoffersen, Pernille; Rognsås, Stine L; Wichstrøm, Lars

2017-01-01

Individuals who are overweight are more likely to underestimate their body size than those who are normal weight, and overweight underestimators are less likely to engage in weight loss efforts. Underestimation of body size might represent a barrier to prevention and treatment of overweight; thus insight in how underestimation of body size develops and tracks through the childhood years is needed. The aim of the present study was therefore to examine stability in children's underestimation of body size, exploring predictors of underestimation over time. The prospective path from underestimation to BMI was also tested. In a Norwegian cohort of 6 year olds, followed up at ages 8 and 10 (analysis sample: n = 793) body size estimation was captured by the Children's Body Image Scale, height and weight were measured and BMI calculated. Overall, children were more likely to underestimate than overestimate their body size. Individual stability in underestimation was modest, but significant. Higher BMI predicted future underestimation, even when previous underestimation was adjusted for, but there was no evidence for the opposite direction of influence. Boys were more likely than girls to underestimate their body size at ages 8 and 10 (age 8: 38.0% vs. 24.1%; Age 10: 57.9% vs. 30.8%) and showed a steeper increase in underestimation with age compared to girls. In conclusion, the majority of 6, 8, and 10-year olds correctly estimate their body size (prevalence ranging from 40 to 70% depending on age and gender), although a substantial portion perceived themselves to be thinner than they actually were. Higher BMI forecasted future underestimation, but underestimation did not increase the risk for excessive weight gain in middle childhood.

Assessing Disfluencies in School-Age Children Who Stutter: How Much Speech Is Enough?

ERIC Educational Resources Information Center

Gregg, Brent A.; Sawyer, Jean

2015-01-01

The question of what size speech sample is sufficient to accurately identify stuttering and its myriad characteristics is a valid one. Short samples have a risk of over- or underrepresenting disfluency types or characteristics. In recent years, there has been a trend toward using shorter samples because they are less time-consuming for…

Potential for adult-based epidemiological studies to characterize overall cancer risks associated with a lifetime of CT scans.

PubMed

Shuryak, Igor; Lubin, Jay H; Brenner, David J

2014-06-01

Recent epidemiological studies have suggested that radiation exposure from pediatric CT scanning is associated with small excess cancer risks. However, the majority of CT scans are performed on adults, and most radiation-induced cancers appear during middle or old age, in the same age range as background cancers. Consequently, a logical next step is to investigate the effects of CT scanning in adulthood on lifetime cancer risks by conducting adult-based, appropriately designed epidemiological studies. Here we estimate the sample size required for such studies to detect CT-associated risks. This was achieved by incorporating different age-, sex-, time- and cancer type-dependent models of radiation carcinogenesis into an in silico simulation of a population-based cohort study. This approach simulated individual histories of chest and abdominal CT exposures, deaths and cancer diagnoses. The resultant sample sizes suggest that epidemiological studies of realistically sized cohorts can detect excess lifetime cancer risks from adult CT exposures. For example, retrospective analysis of CT exposure and cancer incidence data from a population-based cohort of 0.4 to 1.3 million (depending on the carcinogenic model) CT-exposed UK adults, aged 25-65 in 1980 and followed until 2015, provides 80% power for detecting cancer risks from chest and abdominal CT scans.

Aging of a Binary Colloidal Glass

NASA Astrophysics Data System (ADS)

Lynch, Jennifer M.; Cianci, Gianguido C.; Weeks, Eric R.

2008-03-01

After having undergone a glass transition, a glass is in a non-equilibrium state, and its properties depend on the time elapsed since vitrification. We study this phenomenon, known as aging. In particular, we study a colloidal suspension consisting of micron-sized particles in a liquid --- a good model system for studying the glass transition. In this system, the glass transition is approached by increasing the particle concentration, instead of decreasing the temperature. We observe samples composed of particles of two sizes (d1= 1.0μm and d2= 2.0μm) using fast laser scanning confocal microscopy, which yields real-time, three-dimensional movies deep inside the colloidal glass. We then analyze the trajectories of several thousand particles as the glassy suspension ages. Specifically, we look at how the size, motion and structural organization of the particles relate to the overall aging of the glass. We find that areas richer in small particles are more mobile and therefore contribute more to the structural changes found in aging glasses.

A closer look at 40Ar/39Ar systematics of illite, recoil, retention ages, total gas ages, and a new correction method

NASA Astrophysics Data System (ADS)

Fitz-Diaz, E.; Hall, C. M.; van der Pluijm, B.

2013-12-01

One of the fundamentals of 40Ar-39Ar systematics of illite considers the effects of 39Ar recoil (ejection of 39Ar from tiny illite crystallites during the nuclear reaction 39K(n,p)39Ar), for which sample vacuum encapsulation prior to irradiation has been used since the 1990's. This technique separately measures the fraction of recoiled 39Ar and the Ar (39Ar and 40Ar) retained within illite crystals as they degas during step heating in vacuum. Total-gas ages (TGA) are calculated by using both recoiled and retained argon, while retention ages (RA) only involve retained Ar. Observations in numerous natural examples have shown that TGA fit stratigraphic constraints of geological processes when the average illite crystallite thickness (ICT) is smaller than 10nm, and that RA better matches these constrains for larger ICTs. Illite crystals with ICT >50nm show total gas and retention ages within a few My and they are identical, within analytical error, when ICT exceeds 150nm. We propose a new age correction that takes into account the average ICT and corresponding recoil for a sample , with such corrected ages (XCA) lying between the TGA and RA end-member ages. We apply this correction to samples containing one generation of illite and it particularly affects illite populations formed in the anchizone, with typical ICT values between 10-40nm. We analyzed bentonitic samples (S1, S2 and S3) from sites in Cretaceous carbonates in the front of the Monterrey salient in northern Mexico. Four size fractions (<0.05, 0.05-0.2, 0.2-1 & 1-2 μm) were separated, analyzed with XRD and dated by Ar-Ar. XRD analysis provides mineralogic characterization, illite polytype quantification, and illite crystallite thickness (ICT) determination using half-height peak width (illite crystallinity) and the Scherrer equation. All samples contain illite as the main mineral phase, ICT values between 8-27nm, from fine to coarser grain size fractions. Ages show a range in TGA among the different size fractions of S1, S2 and S3, respectively: 46-49, 36-43 and 40-52 My) and RA (54-64, 47-52 and 53-54 My. XCA calculations produce tighter constrained ranges (53-57, 45.5-48.5 and 49-52 My) with an overall average 51.1Ma×3.9 My. In the ICT vs. apparent age plot, authigenic illite grains show a greater slope that is in general slightly positive for TGA, slightly negative for RA, but close to zero for XCA. In the ICT vs. XCA plot thinner crystallites shows more dispersion than thicker ones. In order to test if such dispersion in the age of the finer/thinner illite is due to a different formation history in each site or the result of retention capability, degassing spectra were modeled for site XCA averages and overall XCA average. The modeling shows that local site ages best match the measured spectra, instead of a single age for the combined sites. The closeness between experimental and artificial degassing patterns also supports the hypothesis that each sample preserves a single age population. All illite grains in these samples grew progressively during folding in a time window that is constrained by the three sites. Small and large grains represent the same population in each sample, representing progressive degrees of grain growth (Ostwald ripening).

High-resolution observations of low-luminosity gigahertz-peaked spectrum and compact steep-spectrum sources

NASA Astrophysics Data System (ADS)

Collier, J. D.; Tingay, S. J.; Callingham, J. R.; Norris, R. P.; Filipović, M. D.; Galvin, T. J.; Huynh, M. T.; Intema, H. T.; Marvil, J.; O'Brien, A. N.; Roper, Q.; Sirothia, S.; Tothill, N. F. H.; Bell, M. E.; For, B.-Q.; Gaensler, B. M.; Hancock, P. J.; Hindson, L.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kapińska, A. D.; Lenc, E.; Morgan, J.; Procopio, P.; Staveley-Smith, L.; Wayth, R. B.; Wu, C.; Zheng, Q.; Heywood, I.; Popping, A.

2018-06-01

We present very long baseline interferometry observations of a faint and low-luminosity (L1.4 GHz < 1027 W Hz-1) gigahertz-peaked spectrum (GPS) and compact steep-spectrum (CSS) sample. We select eight sources from deep radio observations that have radio spectra characteristic of a GPS or CSS source and an angular size of θ ≲ 2 arcsec, and detect six of them with the Australian Long Baseline Array. We determine their linear sizes, and model their radio spectra using synchrotron self-absorption (SSA) and free-free absorption (FFA) models. We derive statistical model ages, based on a fitted scaling relation, and spectral ages, based on the radio spectrum, which are generally consistent with the hypothesis that GPS and CSS sources are young and evolving. We resolve the morphology of one CSS source with a radio luminosity of 10^{25} W Hz^{-1}, and find what appear to be two hotspots spanning 1.7 kpc. We find that our sources follow the turnover-linear size relation, and that both homogeneous SSA and an inhomogeneous FFA model can account for the spectra with observable turnovers. All but one of the FFA models do not require a spectral break to account for the radio spectrum, while all but one of the alternative SSA and power-law models do require a spectral break to account for the radio spectrum. We conclude that our low-luminosity sample is similar to brighter samples in terms of their spectral shape, turnover frequencies, linear sizes, and ages, but cannot test for a difference in morphology.

Application of K-Ar Dating to the Chronology of Young Volcanic Centers

NASA Astrophysics Data System (ADS)

Lanphere, M. A.

2003-12-01

K-Ar dating and a derivative technique, 40Ar/39Ar dating, are methods of high-precision chronology applicable to young volcanic centers. Cascade volcanoes studied in detail by several USGS volcanologists, Duane Champion paleomagetist, and me include Mt. Baker, WA; Mt. Rainier, WA; Mt. Adams, WA; Mt. Hood, OR; Crater Lake, OR; and Medicine Lake, CA. For Mt. Adams using detailed geologic mapping by Hildreth and Fierstein and 74 K-Ar ages for 63 mapped units, Hildreth and Lanphere established a detailed chronology for the stratovolcano. Good agreement has been achieved for K-Ar ages and 40Ar/39Ar ages of rocks from Mt. Adams as young as 36 ka. A similar detailed chronology has been established for other Cascade volcanoes using andesites, in particular. These chronologies often take 10 years or more to develop. Major advantages of the 40Ar/39Ar technique are the ability to work with small sample sizes and the possibility to push the technique to very young ages. The Campanian Ignimbrite erupted from the Campi Flegrei crater near Naples, Italy is an example of the use of small samples. Nine incremental-heating ages were determined on samples of sanidine ranging in size from 47 mg to 67 mg. These samples yielded ages for the Campanian Ignimbrite ranging from 37.1 +/- 0.75 ka to 39.5 +/- 0.62 ka and averaging 38.1 +/- 0.8 ka. Other workers have proposed 40Ar/39Ar ages for the Campanian Ignimbrite of 37.1 +/- 0.4 ka and 39.3 +/- 0.1 ka. An example of the use of 40Ar/39Ar dating of very young samples is the Christian Era (CE) age of the Vesuvius eruption of year 79. Eight packets of sanidine weighing 213-296 mg from two localities, Casti Amanti in Pompeii and Villa Poppea in nearby Oplontis, yielded a weighted-mean incremental-heating age of 1924 +/- 66 years. The known age for the CE 79 eruption of Vesuvius is 1924 years. Earlier studies of Vesuvius by other workers yielded an 40Ar/39Ar age for the Villa Poppea locality of 1922 +/- 72 years.

Microstructural changes in steel 10Kh9V2MFBR during creep for 40000 hours at 600°C

NASA Astrophysics Data System (ADS)

Fedoseeva, A. E.; Kozlov, P. A.; Dudko, V. A.; Skorobogatykh, V. N.; Shchenkova, I. A.; Kaibyshev, R. O.

2015-10-01

In this work, we have investigated microstructural changes in steel 10Kh9V2MFBR (analog of P02 steel) after long-term creep tests at a temperature of 600°C under an initial stress of 137 MPa. Time to rupture was found to be more than 40000 h. It has been established that, in the zone of grips and in the neck region of the sample, the size of the particles of the M 23C6 carbides increases from 85 nm to 152 nm and 182 nm, respectively. In addition, large particles of the Laves phase with an average size of 295 nm are separated. The particles of these phases are located along high-angle boundaries. During prolonged aging and creep, the transformation of the M(C,N) particles enriched in V into the Z phase occurs. The average size of particles of the Z phase after prolonged ageing was 48 nm; after creep, it reached 97 nm. The size of M(C,N) particles enriched by Nb increases from 26 nm after tempering to 55 nm after prolonged aging and creep. It has been established that, in spite of an increase in the transverse size of the laths of tempered martensite from 0.4 to 0.9 µm in the neck of the sample, the misorientation of the lath boundaries does not increase. No recrystallization processes were found to develop in the steel during creep.

Magnetic properties of Apollo samples and implications for regolith formation

NASA Technical Reports Server (NTRS)

Pearce, G. W.; Strangway, D. W.; Gose, W. A.

1974-01-01

The magnetic properties of a number of Apollo 17 samples have been measured and confirm that regoliths of mare sites (Apollo 11, 12, 15 valley, and 17 valley) differ markedly from those of highland sites (Apollo 14, 16, and 17 massif) in the ratio of content of metallic to ferrous iron and in the grain size of metallic iron. The ratio of metallic to ferrous iron is correlated with mean particle size, a parameter representing maturity, for soils of Apollo 16 and roughly correlated with the age of the sites for soils of different sites. It is suggested that the ratio of metallic to ferrous iron may be an effective indicator of relative soil maturity for any one site and of the age of the soil material for any sites.

Annealing effects in plated-wire memory elements. II - Recrystallization in Permalloy films.

NASA Technical Reports Server (NTRS)

Marquardt, S. J.; Kench, J. R.

1971-01-01

Results of grain-size measurements in Permalloy platings suggest that recrystallization is possible at temperatures as low as 200 C, but that it is an extremely heterogeneous process. No worthwhile correlation was found to exist between observed grain size and magnetic dispersion in samples aged in the temperature range from 180 to 230 C. It is suggested that the magnetic aging which occurs under these conditions may be due to some other diffusion-controlled process than recrystallization; a process such as chemical homogenization is tentatively preferred.

The Influence of Lath, Block and Prior Austenite Grain (PAG) Size on the Tensile, Creep and Fatigue Properties of Novel Maraging Steel

PubMed Central

McAdam, Steven; Hill, Paul; Rawson, Martin; Perkins, Karen

2017-01-01

The influence of martensitic microstructure and prior austenite grain (PAG) size on the mechanical properties of novel maraging steel was studied. This was achieved by looking at two different martensitic structures with PAG sizes of approximately 40 µm and 80 µm, produced by hot rolling to different reductions. Two ageing heat-treatments were considered: both heat-treatments consisted of austenisation at 960 °C, then aging at 560 °C for 5 h, but while one was rapidly cooled the other was slow cooled and then extended aged at 480 °C for 64 h. It is shown that for the shorter ageing treatment the smaller PAG size resulted in significant improvements in strength (increase of more than 150 MPa), ductility (four times increase), creep life (almost four times increase in creep life) and fatigue life (almost doubled). Whereas, the extended aged sample showed similar changes in the fatigue life, elongation and hardness it displayed yet showed no difference in tensile strength and creep. These results display the complexity of microstructural contributions to mechanical properties in maraging steels. PMID:28773086

Social Relations in Lebanon: Convoys Across the Life Course

PubMed Central

Antonucci, Toni C.; Ajrouch, Kristine J.; Abdulrahim, Sawsan

2015-01-01

Objectives: This study systematically analyzed convoys of social relations to investigate the ways in which gender and income shape patterns of social relations across the life course in Lebanon. Methods: Data were drawn from a representative sample of adults aged 18 and older in Greater Beirut, Lebanon (N = 500). Multiple linear regression and multilevel models were conducted to examine main and interactive effects of age, gender, and income on social relations. Results: Findings indicate main effects of age, income, and gender on network structure and relationship quality. Older age was associated with larger network size, greater proportion of kin in network, higher positive and lower negative relationship quality. Higher income was associated with larger network size and decreased contact frequency. Female gender was also associated with decreased contact frequency. Gender interacted with income to influence network size and network composition. Higher income was associated with a larger network size and higher proportion of kin for women. Discussion: Findings suggest diversity in the experience of social relations. Such nuance is particularly relevant to the Lebanese context where family is the main source of support in old age. Policy makers and program planners may need to refrain from viewing social relations simplistically. PMID:24501252

Are Parents' Gender Schemas Related to Their Children's Gender-Related Cognitions? A Meta-Analysis.

ERIC Educational Resources Information Center

Tenenbaum, Harriet R.; Leaper, Campbell

2002-01-01

Used meta-analysis to examine relationship of parents' gender schemas and their offspring's gender-related cognitions, with samples ranging in age from infancy through early adulthood. Found a small but meaningful effect size (r=.16) indicating a positive correlation between parent gender schema and offspring measures. Effect sizes were influenced…

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

Uzun, Suzan; Ilavsky, Jan; Padua, Graciela Wild

Zein, a protein of corn, has an amphiphilic molecule capable of self-assembly into distinctly different structures. In this work, ultra-small-angle X-ray scattering (USAXS) was applied to investigate the formation of self-assembled zein structures in binary solvent systems of ethanol and water. Our study included observing structural changes due to aging. Three hierarchical structures were identified in zein-solvent systems, molecular zein 2D films, believed to be formed by zein rods assembled first into one-dimensional fibers and then into two-dimensional films, and 3D spherical aggregates. Aging did not change the size or shape of primary units, but promoted their self-assembly into intermediatemore » 2D structures and shaped 3D structures into well19 defined spheres. We found that the rheological parameters, consistency index (K) and behavior index (n), storage and loss moduli (G’ and G”) were also measured. K and n, changed markedly with aging, from nearly Newtonian low consistency fresh samples to highly viscous pseudoplastic aged samples. G’ and G” increased with aging for all samples reflecting increased interactions among zein self-assembled structures. Furthermore, viscoelastic parameters indicated that zein dispersions formed gels upon aging. It was observed that USAX reported on molecular scale self-assembly processes, while rheological measurements reported on the macroscale interaction between self-assembled particles. Raman spectra suggested that α-helix to β-sheet transformations prompted zein self-assembly, which influenced the size and morphology of molecular assemblies and ultimately the rheological properties of zein dispersions.« less

Structural Features of Sibling Dyads and Attitudes toward Sibling Relationships in Young Adulthood

ERIC Educational Resources Information Center

Riggio, Heidi R.

2006-01-01

This study examined sibling-dyad structural variables (sex composition, age difference, current coresidence, position adjacency, family size, respondent and/or sibling ordinal position) and attitudes toward adult sibling relationships. A sample of 1,053 young adults (M age = 22.1 years) described one sibling using the Lifespan Sibling Relationship…

Can Burt's Theory of Structural Holes be Applied to Study Social Support Among Mid-Age Female Sex Workers? A Multi-Site Egocentric Network Study in China.

PubMed

Liu, Hongjie

2017-12-01

The epidemic of HIV/AIDS continues to spread among older adults and mid-age female sex workers (FSWs) over 35 years old. We used egocentric network data collected from three study sites in China to examine the applicability of Burt's Theory of Social Holes to study social support among mid-age FSWs. Using respondent-driven sampling, 1245 eligible mid-age FSWs were interviewed. Network structural holes were measured by network constraint and effective size. Three types of social networks were identified: family networks, workplace networks, and non-FSW networks. A larger effective size was significantly associated with a higher level of social support [regression coefficient (β) 5.43-10.59] across the three study samples. In contrast, a greater constraint was significantly associated with a lower level of social support (β -9.33 to -66.76). This study documents the applicability of the Theory of Structural Holes in studying network support among marginalized populations, such as FSWs.

Synthesizing Information From Language Samples and Standardized Tests in School-Age Bilingual Assessment

PubMed Central

Pham, Giang

2017-01-01

Purpose Although language samples and standardized tests are regularly used in assessment, few studies provide clinical guidance on how to synthesize information from these testing tools. This study extends previous work on the relations between tests and language samples to a new population—school-age bilingual speakers with primary language impairment—and considers the clinical implications for bilingual assessment. Method Fifty-one bilingual children with primary language impairment completed narrative language samples and standardized language tests in English and Spanish. Children were separated into younger (ages 5;6 [years;months]–8;11) and older (ages 9;0–11;2) groups. Analysis included correlations with age and partial correlations between language sample measures and test scores in each language. Results Within the younger group, positive correlations with large effect sizes indicated convergence between test scores and microstructural language sample measures in both Spanish and English. There were minimal correlations in the older group for either language. Age related to English but not Spanish measures. Conclusions Tests and language samples complement each other in assessment. Wordless picture-book narratives may be more appropriate for ages 5–8 than for older children. We discuss clinical implications, including a case example of a bilingual child with primary language impairment, to illustrate how to synthesize information from these tools in assessment. PMID:28055056

Maternal characteristics associated with milk leptin content in a sample of Filipino women and associations with infant weight for age.

PubMed

Quinn, Elizabeth A; Largado, Fe; Borja, Judith B; Kuzawa, Christopher W

2015-05-01

Human milk contains many metabolic hormones that may influence infant growth. Milk leptin is positively associated with maternal adiposity and inversely associated with infant growth. Most research has been conducted in populations with higher leptin levels; it is not well understood how milk leptin may vary in lean populations or the associations that reduced leptin may have with infant size for age. It is also largely unknown if associations between maternal body composition and milk leptin persist past 1 year of age. We investigated the association between maternal body composition and milk leptin content in a sample of lean Filipino women and the association between milk leptin content and infant size for age. Milk samples were collected at in-home visits from 113 mothers from Cebu, Philippines. Milk leptin content was measured using EIA techniques; anthropometric data, dietary recalls, and household information were also collected. Mean ± standard deviation (SD) milk leptin in this sample was 300.7 ± 293.6 pg/mL, among the lowest previously reported. Mean ± SD maternal percentage body fat was 24.8% ± 3.5%. Mean ± SD infant age was 9.9 ± 7.0 months, and mean ± SD weight for age z-score was -0.98 ± 1.06. Maternal percentage body fat was a significant, positive predictor of milk leptin content. Milk leptin was a significant, inverse predictor of infant weight and body mass index z-scores in infants 1 year old or younger. The association between maternal body composition, milk leptin, and infant growth persists in mothers with lean body composition. Milk leptin is not associated with growth in older infants. © The Author(s) 2014.

Age and Growth of Endangered Smalltooth Sawfish (Pristis pectinata) Verified with LA-ICP-MS Analysis of Vertebrae

PubMed Central

Scharer, Rachel M.; Patterson III, William F.; Carlson, John K.; Poulakis, Gregg R.

2012-01-01

Endangered smalltooth sawfish (Pristis pectinata) were opportunistically sampled in south Florida and aged by counting opaque bands in sectioned vertebrae (n = 15). Small sample size precluded traditional age verification, but fish collected in spring and summer had translucent vertebrae margins, while fish collected in winter had opaque margins. Trends in Sr:Ca measured across vertebrae with laser ablation-inductively coupled plasma-mass spectrometry corresponded well to annual salinity trends observed in sawfish estuarine nursery habitats in south Florida, thus serve as a chemical marker verifying annual formation of opaque bands. Based on that finding and assumptions about mean birth date and timing of opaque band formation, estimated age ranged from 0.4 y for a 0.60 m total length (TL) male to 14.0 y for a 4.35 m TL female. Von Bertalanffy growth parameters computed from size at age data were 4.48 m for L∞, 0.219 y−1for k, and −0.81 y for t0. Results of this study have important implications for sawfish conservation as well as for inferring habitat residency of euryhaline elasmobranchs via chemical analysis of vertebrae. PMID:23082225

In vitro inflammatory and cytotoxic effects of size-segregated particulate samples collected during long-range transport of wildfire smoke to Helsinki.

PubMed

Jalava, Pasi I; Salonen, Raimo O; Hälinen, Arja I; Penttinen, Piia; Pennanen, Arto S; Sillanpää, Markus; Sandell, Erik; Hillamo, Risto; Hirvonen, Maija-Riitta

2006-09-15

The impact of long-range transport (LRT) episodes of wildfire smoke on the inflammogenic and cytotoxic activity of urban air particles was investigated in the mouse RAW 264.7 macrophages. The particles were sampled in four size ranges using a modified Harvard high-volume cascade impactor, and the samples were chemically characterized for identification of different emission sources. The particulate mass concentration in the accumulation size range (PM(1-0.2)) was highly increased during two LRT episodes, but the contents of total and genotoxic polycyclic aromatic hydrocarbons (PAH) in collected particulate samples were only 10-25% of those in the seasonal average sample. The ability of coarse (PM(10-2.5)), intermodal size range (PM(2.5-1)), PM(1-0.2) and ultrafine (PM(0.2)) particles to cause cytokine production (TNFalpha, IL-6, MIP-2) reduced along with smaller particle size, but the size range had a much smaller impact on induced nitric oxide (NO) production and cytotoxicity or apoptosis. The aerosol particles collected during LRT episodes had a substantially lower activity in cytokine production than the corresponding particles of the seasonal average period, which is suggested to be due to chemical transformation of the organic fraction during aging. However, the episode events were associated with enhanced inflammogenic and cytotoxic activities per inhaled cubic meter of air due to the greatly increased particulate mass concentration in the accumulation size range, which may have public health implications.

Relationships between media use, body fatness and physical activity in children and youth: a meta-analysis.

PubMed

Marshall, S J; Biddle, S J H; Gorely, T; Cameron, N; Murdey, I

2004-10-01

To review the empirical evidence of associations between television (TV) viewing, video/computer game use and (a) body fatness, and (b) physical activity. Meta-analysis. Published English-language studies were located from computerized literature searches, bibliographies of primary studies and narrative reviews, and manual searches of personal archives. Included studies presented at least one empirical association between TV viewing, video/computer game use and body fatness or physical activity among samples of children and youth aged 3-18 y. The mean sample-weighted corrected effect size (Pearson r). Based on data from 52 independent samples, the mean sample-weighted effect size between TV viewing and body fatness was 0.066 (95% CI=0.056-0.078; total N=44,707). The sample-weighted fully corrected effect size was 0.084. Based on data from six independent samples, the mean sample-weighted effect size between video/computer game use and body fatness was 0.070 (95% CI=-0.048 to 0.188; total N=1,722). The sample-weighted fully corrected effect size was 0.128. Based on data from 39 independent samples, the mean sample-weighted effect size between TV viewing and physical activity was -0.096 (95% CI=-0.080 to -0.112; total N=141,505). The sample-weighted fully corrected effect size was -0.129. Based on data from 10 independent samples, the mean sample-weighted effect size between video/computer game use and physical activity was -0.104 (95% CI=-0.080 to -0.128; total N=119,942). The sample-weighted fully corrected effect size was -0.141. A statistically significant relationship exists between TV viewing and body fatness among children and youth although it is likely to be too small to be of substantial clinical relevance. The relationship between TV viewing and physical activity is small but negative. The strength of these relationships remains virtually unchanged even after correcting for common sources of bias known to impact study outcomes. While the total amount of time per day engaged in sedentary behavior is inevitably prohibitive of physical activity, media-based inactivity may be unfairly implicated in recent epidemiologic trends of overweight and obesity among children and youth. Relationships between sedentary behavior and health are unlikely to be explained using single markers of inactivity, such as TV viewing or video/computer game use.

Kinetic analysis of cooking losses from beef and other animal muscles heated in a water bath--effect of sample dimensions and prior freezing and ageing.

PubMed

Oillic, Samuel; Lemoine, Eric; Gros, Jean-Bernard; Kondjoyan, Alain

2011-07-01

Cooking loss kinetics were measured on cubes and parallelepipeds of beef Semimembranosus muscle ranging from 1 cm × 1 cm × 1 cm to 7 cm × 7 cm × 28 cm in size. The samples were water bath-heated at three different temperatures, i.e. 50°C, 70°C and 90°C, and for five different times. Temperatures were simulated to help interpret the results. Pre-freezing the sample, difference in ageing time, and in muscle fiber orientation had little influence on cooking losses. At longer treatment times, the effects of sample size disappeared and cooking losses depended only on the temperature. A selection of the tests was repeated on four other beef muscles and on veal, horse and lamb Semimembranosus muscle. Kinetics followed similar curves in all cases but resulted in different final water contents. The shape of the kinetics curves suggests first-order kinetics. Copyright © 2011 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Cosmic ray exposure ages of iron meteorites, complex irradiation and the constancy of cosmic ray flux in the past

NASA Technical Reports Server (NTRS)

Marti, K.; Lavielle, B.; Regnier, S.

1984-01-01

While previous calculations of potassium ages assumed a constant cosmic ray flux and a single stage (no change in size) exposure of iron meteorites, present calculations relaxed these constancy assumptions and the results reveal multistage irradiations for some 25% of the meteorites studied, implying multiple breakup in space. The distribution of exposure ages suggests several major collisions (based on chemical composition and structure), although the calibration of age scales is not yet complete. It is concluded that shielding-corrected (corrections which depend on size and position of sample) production rates are consistent for the age bracket of 300 to 900 years. These production rates differ in a systematic way from those calculated for present day fluxes of cosmic rays (such as obtained for the last few million years).

Superficial and deep changes of histology, texture and particle size distribution in broiler wooden breast muscle during refrigerated storage.

PubMed

Soglia, Francesca; Gao, Jingxian; Mazzoni, Maurizio; Puolanne, Eero; Cavani, Claudio; Petracci, Massimiliano; Ertbjerg, Per

2017-09-01

Recently the poultry industry faced an emerging muscle abnormality termed wooden breast (WB), the prevalence of which has dramatically increased in the past few years. Considering the incomplete knowledge concerning this condition and the lack of information on possible variations due to the intra-fillet sampling locations (superficial vs. deep position) and aging of the samples, this study aimed at investigating the effect of 7-d storage of broiler breast muscles on histology, texture, and particle size distribution, evaluating whether the sampling position exerts a relevant role in determining the main features of WB. With regard to the histological observations, severe myodegeneration accompanied by accumulation of connective tissue was observed within the WB cases, irrespective of the intra-fillet sampling position. No changes in the histological traits took place during the aging in either the normal or the WB samples. As to textural traits, although a progressive tenderization process took place during storage (P ≤ 0.001), the differences among the groups were mainly detected when raw meat rather than cooked was analyzed, with the WB samples exhibiting the highest (P ≤ 0.001) 80% compression values. In spite of the increased amount of connective tissue components in the WB cases, their thermally labile cross-links will account for the similar compression and shear-force values as normal breast cases when measured on cooked samples. Similarly, the enlargement of extracellular matrix and fibrosis might contribute in explaining the different fragmentation patterns observed between the superficial and the deep layer in the WB samples, with the superficial part exhibiting a higher amount of larger particles and an increase in particles with larger size during storage, compared to normal breasts. © 2017 Poultry Science Association Inc.

Estimating population sizes for elusive animals: the forest elephants of Kakum National Park, Ghana.

PubMed

Eggert, L S; Eggert, J A; Woodruff, D S

2003-06-01

African forest elephants are difficult to observe in the dense vegetation, and previous studies have relied upon indirect methods to estimate population sizes. Using multilocus genotyping of noninvasively collected samples, we performed a genetic survey of the forest elephant population at Kakum National Park, Ghana. We estimated population size, sex ratio and genetic variability from our data, then combined this information with field observations to divide the population into age groups. Our population size estimate was very close to that obtained using dung counts, the most commonly used indirect method of estimating the population sizes of forest elephant populations. As their habitat is fragmented by expanding human populations, management will be increasingly important to the persistence of forest elephant populations. The data that can be obtained from noninvasively collected samples will help managers plan for the conservation of this keystone species.

24-Month-Old Children with Larger Oral Vocabularies Display Greater Academic and Behavioral Functioning at Kindergarten Entry

ERIC Educational Resources Information Center

Morgan, Paul L.; Farkas, George; Hillemeier, Marianne M.; Hammer, Carol Scheffner; Maczuga, Steve

2015-01-01

Data were analyzed from a population-based, longitudinal sample of 8,650 U.S. children to (a) identify factors associated with or predictive of oral vocabulary size at 24 months of age and (b) evaluate whether oral vocabulary size is uniquely predictive of academic and behavioral functioning at kindergarten entry. Children from higher…

Corpus Callosum Size, Reaction Time Speed and Variability in Mild Cognitive Disorders and in a Normative Sample

ERIC Educational Resources Information Center

Anstey, Kaarin J.; Mack, Holly A.; Christensen, Helen; Li, Shu-Chen; Reglade-Meslin, Chantal; Maller, Jerome; Kumar, Rajeev; Dear, Keith; Easteal, Simon; Sachdev, Perminder

2007-01-01

Intra-individual variability in reaction time increases with age and with neurological disorders, but the neural correlates of this increased variability remain uncertain. We hypothesized that both faster mean reaction time (RT) and less intra-individual RT variability would be associated with larger corpus callosum (CC) size in older adults, and…

Indexing the relative abundance of age-0 white sturgeons in an impoundment of the lower Columbia River from highly skewed trawling data

USGS Publications Warehouse

Counihan, T.D.; Miller, Allen I.; Parsley, M.J.

1999-01-01

The development of recruitment monitoring programs for age-0 white sturgeons Acipenser transmontanus is complicated by the statistical properties of catch-per-unit-effort (CPUE) data. We found that age-0 CPUE distributions from bottom trawl surveys violated assumptions of statistical procedures based on normal probability theory. Further, no single data transformation uniformly satisfied these assumptions because CPUE distribution properties varied with the sample mean (??(CPUE)). Given these analytic problems, we propose that an additional index of age-0 white sturgeon relative abundance, the proportion of positive tows (Ep), be used to estimate sample sizes before conducting age-0 recruitment surveys and to evaluate statistical hypothesis tests comparing the relative abundance of age-0 white sturgeons among years. Monte Carlo simulations indicated that Ep was consistently more precise than ??(CPUE), and because Ep is binomially rather than normally distributed, surveys can be planned and analyzed without violating the assumptions of procedures based on normal probability theory. However, we show that Ep may underestimate changes in relative abundance at high levels and confound our ability to quantify responses to management actions if relative abundance is consistently high. If data suggest that most samples will contain age-0 white sturgeons, estimators of relative abundance other than Ep should be considered. Because Ep may also obscure correlations to climatic and hydrologic variables if high abundance levels are present in time series data, we recommend ??(CPUE) be used to describe relations to environmental variables. The use of both Ep and ??(CPUE) will facilitate the evaluation of hypothesis tests comparing relative abundance levels and correlations to variables affecting age-0 recruitment. Estimated sample sizes for surveys should therefore be based on detecting predetermined differences in Ep, but data necessary to calculate ??(CPUE) should also be collected.

The late Neandertal supraorbital fossils from Vindija Cave, Croatia: a biased sample?

PubMed

Ahern, James C M; Lee, Sang-Hee; Hawks, John D

2002-09-01

The late Neandertal sample from Vindija (Croatia) has been described as transitional between the earlier Central European Neandertals from Krapina (Croatia) and modern humans. However, the morphological differences indicating this transition may rather be the result of different sex and/or age compositions between the samples. This study tests the hypothesis that the metric differences between the Krapina and Vindija supraorbital samples are due to sampling bias. We focus upon the supraorbital region because past studies have posited this region as particularly indicative of the Vindija sample's transitional nature. Furthermore, the supraorbital region varies significantly with both age and sex. We analyzed four chords and two derived indices of supraorbital torus form as defined by Smith & Ranyard (1980, Am. J. phys. Anthrop.93, pp. 589-610). For each variable, we analyzed relative sample bias of the Krapina and Vindija samples using three sampling methods. In order to test the hypothesis that the Vindija sample contains an over-representation of females and/or young while the Krapina sample is normal or also female/young biased, we determined the probability of drawing a sample of the same size as and with a mean equal to or less than Vindija's from a Krapina-based population. In order to test the hypothesis that the Vindija sample is female/young biased while the Krapina sample is male/old biased, we determined the probability of drawing a sample of the same size as and with a mean equal or less than Vindija's from a generated population whose mean is halfway between Krapina's and Vindija's. Finally, in order to test the hypothesis that the Vindija sample is normal while the Krapina sample contains an over-representation of males and/or old, we determined the probability of drawing a sample of the same size as and with a mean equal to or greater than Krapina's from a Vindija-based population. Unless we assume that the Vindija sample is female/young and the Krapina sample is male/old biased, our results falsify the hypothesis that the metric differences between the Krapina and Vindija samples are due to sample bias.

Topical anesthesia for rubber dam clamp placement in sealant placement: comparison of lidocaine/prilocaine gel and benzocaine.

PubMed

Yoon, Richard K; Chussid, Steven

2009-01-01

The purpose of this prospective study was to compare the efficacy of Oraqix to benzocaine while placing a rubber dam clamp during sealant placement on children. A sample size of 45 7- to 12-year-old patients who presented for bilateral sealants on permanent first molars participated in this study. A split-mouth design was implemented with Oraqix applied to one side and 20 percent benzocaine gel applied to the other. After placing the topical anesthetic and the rubber dam clamp, patients completed a Feces Pain Scale (FPS) to rate the level of discomfort after clamp placement. Twenty-seven subjects (60%) were female and 18 subjects (40%) were mole; 15 (33%) were younger than 9 years old and 30 (67%) were at least 9 years old. The overall difference in mean FPS ratings was not statistically significant (P = .27). Regarding gender, there was no statistically significant difference in males (P = .65) or females (P = .26). There was also no difference in mean FPS ratings when looking at age groups younger than 9 years old with P=.77 In the 9 years and older age groups, however there was a statistically significant difference, with P = .04. Application of Oraqix did not reduce discomfort when compared to benzocaine in this small sample size. Oraqix was more effective than benzocaine in the age group 9 and older. A larger sample size is needed to determine its efficacy in children younger than 9years old.

[Estimated prevalence of autism spectrum disorders in the Canary Islands].

PubMed

Fortea Sevilla, M S; Escandell Bermúdez, M O; Castro Sánchez, J J

2013-12-01

To make an initial estimate of the prevalence of autism spectrum disorders (ASDs) among children in the province of Las Palmas (Spain). Descriptive study was conducted on 1,796 children between the ages of 18 and 30 months of age, all part of the Child Health Surveillance of the Canary Islands, more specifically the province of Las Palmas, with a population of 1,090,605. The parents of children involved completed the Spanish version of the Modified Checklist for Autism in Toddlers (M-CHAT/ES) in the paediatric clinic. The positive cases were then diagnosed by experts by means of the Autism Diagnostic Interview-Revised (ADIR) and the Autism Diagnostic Observation Schedule (ADOS). A 0.61% prevalence of ASDs was determined, similar to that reported in previous studies using the same tools. The ratio was six girls for every five boys. This was contrary to the results of previous studies which suggested more boys than girls were affected. This may have been due to the sample size, which will have to be increased in future studies to confirm this outcome. An increased sample size and also spread to other age ranges should be used in order to obtain a more reliable estimate of prevalence. As regards the gender ratio, this could be a result of the small size of the sample researched, and should therefore be confirmed by further studies. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Pupil size in Jewish theological seminary students.

PubMed

Shemesh, G; Kesler, A; Lazar, M; Rothkoff, L

2004-01-01

To investigate the authors' clinical impression that pupil size among myopic Jewish theological seminary students is different from pupil size of similar secular subjects. This cross-sectional study was conducted on 28 male Jewish theological seminary students and 28 secular students or workers who were matched for age and refraction. All participants were consecutively enrolled. Scotopic and photopic pupil size was measured by means of a Colvard pupillometer. Comparisons of various parameters between the groups were performed using the two-sample t-test, Fisher exact test, a paired-sample t-test, a two-way analysis of variance, and Pearson correlation coefficients as appropriate. The two groups were statistically matched for age, refraction, and visual acuity. The seminary students were undercorrected by an average of 2.35 diopters (D), while the secular subjects were undercorrected by only 0.65 D (p<0.01). The average pupil size was larger in the religious group under both scotopic and photopic luminance. This difference was maintained when the two groups were compared according to iris color under both conditions, reaching a level of statistical significance (p<0.0001). There was a significant difference in photopic pupil size between dark and light irises (p=0.049), but this difference was not maintained under scotopic conditions. The average pupil size of young ultraorthodox seminary students was significantly larger than that of matched secular subjects. Whether this is the result of intensive close-up work or of apparently characteristic undercorrection of the myopia is undetermined.

Height-age relationships for regeneration-size trees in the northern Rocky Mountains, USA

Treesearch

Dennis E. Ferguson; Clinton E. Carlson

2010-01-01

Regression equations were developed to predict heights of 10 conifer species inregenerating stands in central and northern Idaho, western Montana, and eastern Washington. Most sample trees were natural regeneration that became established after conventional harvest and site preparation methods. Heights are predicted as a function of tree age, residual overstory density...

Age-related differences in morphological characteristics of residual skin surface components collected from the surface of facial skin of healthy male volunteers.

PubMed

Chalyk, N E; Bandaletova, T Y; Kyle, N H; Petyaev, I M

2017-05-01

Global increase of human longevity results in the emergence of previously ignored ageing-related problems. Skin ageing is a well-known phenomenon, but active search for scientific approaches to its prevention and even skin rejuvenation is a relatively new area. Although the structure and composition of the stratum corneum (SC), the superficial layer of epidermis, is well studied, relatively little is known about the residual skin surface components (RSSC) that overlay the surface of the SC. The aim of this study was to examine morphological features of RSSC samples non-invasively collected from the surface of human facial skin for the presence of age-related changes. Residual skin surface component samples were collected by swabbing from the surface of facial skin of 60 adult male volunteers allocated in two age groups: 34 subjects aged in the range 18-32 years and 26 subjects aged in the range 58-72 years. The collected samples were analysed microscopically: the size of the lipid droplets was measured; desquamated corneocytes and lipid crystals were counted; and microbial presence was assessed semi-quantitatively. Age-related changes were revealed for all studied components of the RSSC. There was a significant (P = 0.0126) decrease in the size of lipid droplets among older men. Likewise, significantly (P = 0.0252) lower numbers of lipid crystals were present in this group. In contrast, microbial presence in the RSSC was significantly (P = 0.0019) increased in the older group. There was also a trend towards more abundant corneocyte desquamation among older men, but the difference has not reached statistical significance (P = 0.0636). Non-invasively collected RSSC samples present an informative material for studying age-related changes on the surface of the SC of human facial skin. The results of this study confirm earlier observations regarding age-associated decline of the efficiency of the epidermal barrier and can be used for testing new approaches to skin ageing prevention. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Trap elimination and reduction of size dispersion due to aging in CdS x Se1- x quantum dots

NASA Astrophysics Data System (ADS)

Verma, Abhishek; Nagpal, Swati; Pandey, Praveen K.; Bhatnagar, P. K.; Mathur, P. C.

2007-12-01

Quantum Dots of CdS x Se1- x embedded in borosilicate glass matrix have been grown using Double-Step annealing method. Optical characterization of the quantum dots has been done through the combinative analysis of optical absorption and photoluminescence spectroscopy at room temperature. Decreasing trend of photoluminescence intensity with aging has been observed and is attributed to trap elimination. The changes in particle size, size distribution, number of quantum dots, volume fraction, trap related phenomenon and Gibbs free energy of quantum dots, has been explained on the basis of the diffusion-controlled growth process, which continues with passage of time. For a typical case, it was found that after 24 months of aging, the average radii increased from 3.05 to 3.12 nm with the increase in number of quantum dots by 190% and the size-dispersion decreased from 10.8% to 9.9%. For this sample, the initial size range of the quantum dots was 2.85 to 3.18 nm. After that no significant change was found in these parameters for the next 12 months. This shows that the system attains almost a stable nature after 24 months of aging. It was also observed that the size-dispersion in quantum dots reduces with the increase in annealing duration, but at the cost of quantum confinement effect. Therefore, a trade off optimization has to be done between the size-dispersion and the quantum confinement.

Impact of Thermal Aging on the Microstructure Evolution and Mechanical Properties of Lanthanum-Doped Tin-Silver-Copper Lead-Free Solders

NASA Astrophysics Data System (ADS)

Sadiq, Muhammad; Pesci, Raphaël; Cherkaoui, Mohammed

2013-03-01

An extensive study is made to analyze the impact of pure lanthanum on the microstructure and mechanical properties of Sn-Ag-Cu (SAC) alloys at high temperatures. Different compositions are tested; the temperature applied for the isothermal aging is 150°C, and aging times of 10 h, 25 h, 50 h, 100 h, and 200 h are studied. Optical microscopy with cross-polarized light is used to follow the grain size, which is refined from 8 mm to 1 mm for as-cast samples and is maintained during thermal aging. Intermetallic compounds (IMCs) present inside the bulk Sn matrix affect the mechanical properties of the SAC alloys. Due to high-temperature exposure, these IMCs grow and hence their impact on mechanical properties becomes more significant. This growth is followed by scanning electron microscopy, and energy-dispersive spectroscopy is used for elemental mapping of each phase. A significant refinement in the average size of IMCs of up to 40% is identified for the as-cast samples, and the coarsening rate of these IMCs is slowed by up to 70% with no change in the interparticle spacing. Yield stress and tensile strength are determined through tensile testing at 20°C for as-cast samples and after thermal aging at 150°C for 100 h and 200 h. Both yield stress and tensile strength are increased by up to 20% by minute lanthanum doping.

The Emotions of Socialization-Related Learning: Understanding Workplace Adaptation as a Learning Process.

ERIC Educational Resources Information Center

Reio, Thomas G., Jr.

The influence of selected discrete emotions on socialization-related learning and perception of workplace adaptation was examined in an exploratory study. Data were collected from 233 service workers in 4 small and medium-sized companies in metropolitan Washington, D.C. The sample members' average age was 32.5 years, and the sample's racial makeup…

Characterization of zein assemblies by ultra-small-angle X-ray scattering

DOE PAGES

Uzun, Suzan; Ilavsky, Jan; Padua, Graciela Wild

2017-03-23

Zein, a protein of corn, has an amphiphilic molecule capable of self-assembly into distinctly different structures. In this work, ultra-small-angle X-ray scattering (USAXS) was applied to investigate the formation of self-assembled zein structures in binary solvent systems of ethanol and water. Our study included observing structural changes due to aging. Three hierarchical structures were identified in zein-solvent systems, molecular zein 2D films, believed to be formed by zein rods assembled first into one-dimensional fibers and then into two-dimensional films, and 3D spherical aggregates. Aging did not change the size or shape of primary units, but promoted their self-assembly into intermediatemore » 2D structures and shaped 3D structures into well19 defined spheres. We found that the rheological parameters, consistency index (K) and behavior index (n), storage and loss moduli (G’ and G”) were also measured. K and n, changed markedly with aging, from nearly Newtonian low consistency fresh samples to highly viscous pseudoplastic aged samples. G’ and G” increased with aging for all samples reflecting increased interactions among zein self-assembled structures. Furthermore, viscoelastic parameters indicated that zein dispersions formed gels upon aging. It was observed that USAX reported on molecular scale self-assembly processes, while rheological measurements reported on the macroscale interaction between self-assembled particles. Raman spectra suggested that α-helix to β-sheet transformations prompted zein self-assembly, which influenced the size and morphology of molecular assemblies and ultimately the rheological properties of zein dispersions.« less

Modelling detrital coral grain-size and age: Insights from sediment abrasion process of Yongle Atoll of South China Sea

NASA Astrophysics Data System (ADS)

Li, Y.; Zou, X.; Ge, C.; Tan, M.; Wang, C.

2017-12-01

Reef islands situated on the rims of atolls are composed almost exclusively of bioclastic materials locally supplied from adjacent coral reefs. Major skeletal component of these islands include coral, coralline algae, mollusks and foraminifera, produced in adjacent reefs. As the island builder, the bioclastic material is the sedimentary products, which also is the point of penetration to decipher the process. The bioclast of coral islands decrease in size with the transportation process. The grain-size provides a proxy record for the abrasion history of the unconsolidated sediment. The 230Th age of coral record the abrasion time. We hereby present a model to calculate the abrasion rate based on the data of 230Th age and grain-size of Yongle Atoll of Xisha Island, South China Sea. The grain size pattern in Yongle Atoll environment have confirm that the coral article diminution behave exponentially. The sediment composition of Yongle Atoll is identified, coral is dominant sediment constituent and the Th230 age is shown to exert an age distribution characteristics of coral detritus. We illustrate this approach by calculate the coral debris age of Xude Atoll, which located near the Yongle Atoll and then by comparing actual measured age and calculated age and to explore the dependence of the model. Observed 230 Th ages are well matched by predicted ages for medium age sediment. A poorer match for young and old sediment may result from some combination of large analytical uncertainties in the detrital ages and inhomogeneous erosion rates within the atoll. Such mismatches emphasize the need for more accurate kinematic models and for sampling strategies that are adapted to atoll-specific geologic and geomorphic conditions. Results presented constitute important new insights into regional sediment abrasion processed and on the evolution of coral atoll islands.

Post-breeding bird responses to canopy tree retention, stand size, and edge in regenerating Appalachian hardwood stands

USGS Publications Warehouse

McDermott, Molly E.; Wood, Petra B.

2011-01-01

Avian use of even-aged timber harvests is likely affected by stand attributes such as size, amount of edge, and retained basal area, all characteristics that can easily be manipulated in timber harvesting plans. However, few studies have examined their effects during the post-breeding period. We studied the impacts of clearcut, low-leave two-age, and high-leave two-age harvesting on post-breeding birds using transect sampling and mist-netting in north-central West Virginia. In our approach, we studied the effects of these harvest types as well as stand size and edge on species characteristic of both early-successional and mature forest habitats. In 2005–2006, 13 stands ranging from 4 to 10 years post-harvest and 4–21 ha in size were sampled from late June through mid-August. Capture rates and relative abundance were similar among treatments for generalist birds. Early-successional birds had the lowest capture rates and fewer species (∼30% lower), and late-successional birds reached their highest abundance and species totals (double the other treatments) in high-leave two-age stands. Area sensitivity was evident for all breeding habitat groups. Both generalist and late-successional bird captures were negatively related to stand size, but these groups showed no clear edge effects. Mean relative abundance decreased to nearly zero for the latter group in the largest stands. In contrast, early-successional species tended to use stand interiors more often and responded positively to stand size. Capture rates for this group tripled as stand size increased from 4 to 21 ha. Few birds in the forest periphery responded to harvest edge types despite within-stand edge effects evident for several species. To create suitable habitat for early-successional birds, large, non-linear openings with a low retained basal area are ideal, while smaller harvests and increased residual tree retention would provide habitat for more late-successional birds post-breeding. Although our study has identified habitat use patterns for different species in timber harvests, understanding habitat-specific bird survival is needed to help determine the quality of silvicultural harvests for post-breeding birds.

In vitro inflammatory and cytotoxic effects of size-segregated particulate samples collected during long-range transport of wildfire smoke to Helsinki

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

Jalava, Pasi I.; Salonen, Raimo O.; Haelinen, Arja I.

2006-09-15

The impact of long-range transport (LRT) episodes of wildfire smoke on the inflammogenic and cytotoxic activity of urban air particles was investigated in the mouse RAW 264.7 macrophages. The particles were sampled in four size ranges using a modified Harvard high-volume cascade impactor, and the samples were chemically characterized for identification of different emission sources. The particulate mass concentration in the accumulation size range (PM{sub 1-0.2}) was highly increased during two LRT episodes, but the contents of total and genotoxic polycyclic aromatic hydrocarbons (PAH) in collected particulate samples were only 10-25% of those in the seasonal average sample. The abilitymore » of coarse (PM{sub 10-2.5}), intermodal size range (PM{sub 2.5-1}), PM{sub 1-0.2} and ultrafine (PM{sub 0.2}) particles to cause cytokine production (TNF{alpha}, IL-6, MIP-2) reduced along with smaller particle size, but the size range had a much smaller impact on induced nitric oxide (NO) production and cytotoxicity or apoptosis. The aerosol particles collected during LRT episodes had a substantially lower activity in cytokine production than the corresponding particles of the seasonal average period, which is suggested to be due to chemical transformation of the organic fraction during aging. However, the episode events were associated with enhanced inflammogenic and cytotoxic activities per inhaled cubic meter of air due to the greatly increased particulate mass concentration in the accumulation size range, which may have public health implications.« less

Observational studies of patients in the emergency department: a comparison of 4 sampling methods.

PubMed

Valley, Morgan A; Heard, Kennon J; Ginde, Adit A; Lezotte, Dennis C; Lowenstein, Steven R

2012-08-01

We evaluate the ability of 4 sampling methods to generate representative samples of the emergency department (ED) population. We analyzed the electronic records of 21,662 consecutive patient visits at an urban, academic ED. From this population, we simulated different models of study recruitment in the ED by using 2 sample sizes (n=200 and n=400) and 4 sampling methods: true random, random 4-hour time blocks by exact sample size, random 4-hour time blocks by a predetermined number of blocks, and convenience or "business hours." For each method and sample size, we obtained 1,000 samples from the population. Using χ(2) tests, we measured the number of statistically significant differences between the sample and the population for 8 variables (age, sex, race/ethnicity, language, triage acuity, arrival mode, disposition, and payer source). Then, for each variable, method, and sample size, we compared the proportion of the 1,000 samples that differed from the overall ED population to the expected proportion (5%). Only the true random samples represented the population with respect to sex, race/ethnicity, triage acuity, mode of arrival, language, and payer source in at least 95% of the samples. Patient samples obtained using random 4-hour time blocks and business hours sampling systematically differed from the overall ED patient population for several important demographic and clinical variables. However, the magnitude of these differences was not large. Common sampling strategies selected for ED-based studies may affect parameter estimates for several representative population variables. However, the potential for bias for these variables appears small. Copyright © 2012. Published by Mosby, Inc.

Phonological skills and their role in learning to read: a meta-analytic review.

PubMed

Melby-Lervåg, Monica; Lyster, Solveig-Alma Halaas; Hulme, Charles

2012-03-01

The authors report a systematic meta-analytic review of the relationships among 3 of the most widely studied measures of children's phonological skills (phonemic awareness, rime awareness, and verbal short-term memory) and children's word reading skills. The review included both extreme group studies and correlational studies with unselected samples (235 studies were included, and 995 effect sizes were calculated). Results from extreme group comparisons indicated that children with dyslexia show a large deficit on phonemic awareness in relation to typically developing children of the same age (pooled effect size estimate: -1.37) and children matched on reading level (pooled effect size estimate: -0.57). There were significantly smaller group deficits on both rime awareness and verbal short-term memory (pooled effect size estimates: rime skills in relation to age-matched controls, -0.93, and reading-level controls, -0.37; verbal short-term memory skills in relation to age-matched controls, -0.71, and reading-level controls, -0.09). Analyses of studies of unselected samples showed that phonemic awareness was the strongest correlate of individual differences in word reading ability and that this effect remained reliable after controlling for variations in both verbal short-term memory and rime awareness. These findings support the pivotal role of phonemic awareness as a predictor of individual differences in reading development. We discuss whether such a relationship is a causal one and the implications of research in this area for current approaches to the teaching of reading and interventions for children with reading difficulties.

Is family size related to adolescence mental hospitalization?

PubMed

Kylmänen, Paula; Hakko, Helinä; Räsänen, Pirkko; Riala, Kaisa

2010-05-15

The aim of this study was to investigate the association between family size and psychiatric disorders of underage adolescent psychiatric inpatients. The study sample consisted of 508 adolescents (age 12-17) admitted to psychiatric impatient care between April 2001 and March 2006. Diagnostic and Statistical Manual of Mental Disorders, fourth edition-based psychiatric diagnoses and variables measuring family size were obtained from the Schedule for Affective Disorder and Schizophrenia for School-Age Children Present and Lifetime (K-SADS-PL). The family size of the general Finnish population was used as a reference population. There was a significant difference between the family size of the inpatient adolescents and the general population: 17.0% of adolescents came from large families (with 6 or more children) while the percentage in the general population was 3.3. A girl from a large family had an about 4-fold risk of psychosis other than schizophrenia. However, large family size was not associated with a risk for schizophrenia. Large family size was overrepresented among underage adolescents admitted for psychiatric hospitalization in Northern Finland. Copyright 2009 Elsevier Ltd. All rights reserved.

Malaria prevalence metrics in low- and middle-income countries: an assessment of precision in nationally-representative surveys.

PubMed

Alegana, Victor A; Wright, Jim; Bosco, Claudio; Okiro, Emelda A; Atkinson, Peter M; Snow, Robert W; Tatem, Andrew J; Noor, Abdisalan M

2017-11-21

One pillar to monitoring progress towards the Sustainable Development Goals is the investment in high quality data to strengthen the scientific basis for decision-making. At present, nationally-representative surveys are the main source of data for establishing a scientific evidence base, monitoring, and evaluation of health metrics. However, little is known about the optimal precisions of various population-level health and development indicators that remains unquantified in nationally-representative household surveys. Here, a retrospective analysis of the precision of prevalence from these surveys was conducted. Using malaria indicators, data were assembled in nine sub-Saharan African countries with at least two nationally-representative surveys. A Bayesian statistical model was used to estimate between- and within-cluster variability for fever and malaria prevalence, and insecticide-treated bed nets (ITNs) use in children under the age of 5 years. The intra-class correlation coefficient was estimated along with the optimal sample size for each indicator with associated uncertainty. Results suggest that the estimated sample sizes for the current nationally-representative surveys increases with declining malaria prevalence. Comparison between the actual sample size and the modelled estimate showed a requirement to increase the sample size for parasite prevalence by up to 77.7% (95% Bayesian credible intervals 74.7-79.4) for the 2015 Kenya MIS (estimated sample size of children 0-4 years 7218 [7099-7288]), and 54.1% [50.1-56.5] for the 2014-2015 Rwanda DHS (12,220 [11,950-12,410]). This study highlights the importance of defining indicator-relevant sample sizes to achieve the required precision in the current national surveys. While expanding the current surveys would need additional investment, the study highlights the need for improved approaches to cost effective sampling.

Interventions targeting substance abuse among women survivors of intimate partner abuse: a meta-analysis.

PubMed

Fowler, Dawnovise N; Faulkner, Monica

2011-12-01

In this article, meta-analytic techniques are used to examine existing intervention studies (n = 11) to determine their effects on substance abuse among female samples of intimate partner abuse (IPA) survivors. This research serves as a starting point for greater attention in research and practice to the implementation of evidence-based, integrated services to address co-occurring substance abuse and IPA victimization among women as major intersecting public health problems. The results show greater effects in three main areas. First, greater effect sizes exist in studies where larger numbers of women experienced current IPA. Second, studies with a lower mean age also showed greater effect sizes than studies with a higher mean age. Lastly, studies with smaller sample sizes have greater effects. This research helps to facilitate cohesion in the knowledge base on this topic, and the findings of this meta-analysis, in particular, contribute needed information to gaps in the literature on the level of promise of existing interventions to impact substance abuse in this underserved population. Published by Elsevier Inc.

A Meta-analytic Review of Non-specific Effects in Randomized Controlled Trials of Cognitive Remediation for Schizophrenia.

PubMed

Radhakrishnan, Rajiv; Kiluk, Brian D; Tsai, Jack

2016-03-01

Cognitive remediation (CR) has been found to improve cognitive performance among adults with schizophrenia in randomized controlled trials (RCTs). However, improvements in cognitive performance are often observed in the control groups of RCTs as well. There has been no comprehensive examination of change in control groups for CR, which may inform trial methodology and improve our understanding of measured outcomes for cognitive remediation. In this meta-analysis, we calculated pre-post change in cognitive test performance within control groups of RCTs in 32 CR trials (n = 794 participants) published between 1970 and 2011, and examined the association between pre-post change and sample size, duration of treatment, type of control group, and participants' age, intelligence, duration of illness, and psychiatric symptoms. Results showed that control groups in CR trials showed small effect size changes (Cohen's d = 0.12 ± 0.16) in cognitive test performance over the trial duration. Study characteristics associated with pre-post change included participant age and sample size. These findings suggest attention to change in control groups may help improve detection of cognitive remediation effects for schizophrenia.

Functional modular architecture underlying attentional control in aging.

PubMed

Monge, Zachary A; Geib, Benjamin R; Siciliano, Rachel E; Packard, Lauren E; Tallman, Catherine W; Madden, David J

2017-07-15

Previous research suggests that age-related differences in attention reflect the interaction of top-down and bottom-up processes, but the cognitive and neural mechanisms underlying this interaction remain an active area of research. Here, within a sample of community-dwelling adults 19-78 years of age, we used diffusion reaction time (RT) modeling and multivariate functional connectivity to investigate the behavioral components and whole-brain functional networks, respectively, underlying bottom-up and top-down attentional processes during conjunction visual search. During functional MRI scanning, participants completed a conjunction visual search task in which each display contained one item that was larger than the other items (i.e., a size singleton) but was not informative regarding target identity. This design allowed us to examine in the RT components and functional network measures the influence of (a) additional bottom-up guidance when the target served as the size singleton, relative to when the distractor served as the size singleton (i.e., size singleton effect) and (b) top-down processes during target detection (i.e., target detection effect; target present vs. absent trials). We found that the size singleton effect (i.e., increased bottom-up guidance) was associated with RT components related to decision and nondecision processes, but these effects did not vary with age. Also, a modularity analysis revealed that frontoparietal module connectivity was important for both the size singleton and target detection effects, but this module became central to the networks through different mechanisms for each effect. Lastly, participants 42 years of age and older, in service of the target detection effect, relied more on between-frontoparietal module connections. Our results further elucidate mechanisms through which frontoparietal regions support attentional control and how these mechanisms vary in relation to adult age. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Gilbertson, Robert D.; Patterson, Brian M.; Smith, Zachary

An accelerated aging study of BKC 44306-10 rigid polyurethane foam was carried out. Foam samples were aged in a nitrogen atmosphere at three different temperatures: 50 °C, 65 °C, and 80 °C. Foam samples were periodically removed from the aging canisters at 1, 3, 6, 9, 12, and 15 month intervals when FT-IR spectroscopy, dimensional analysis, and mechanical testing experiments were performed. Micro Computed Tomography imaging was also employed to study the morphology of the foams. Over the course of the aging study the foams the decreased in size by a magnitude of 0.001 inches per inch of foam. Micromore » CT showed the heterogeneous nature of the foam structure likely resulting from flow effects during the molding process. The effect of aging on the compression and tensile strength of the foam was minor and no cause for concern. FT-IR spectroscopy was used to follow the foam chemistry. However, it was difficult to draw definitive conclusions about the changes in chemical nature of the materials due to large variability throughout the samples.« less

Assessing the role of detrital zircon sorting on provenance interpretations in an ancient fluvial system using paleohydraulics - Permian Cutler Group, Paradox Basin, Utah and Colorado

NASA Astrophysics Data System (ADS)

Findlay, C. P., III; Ewing, R. C.; Perez, N. D.

2017-12-01

Detrital zircon age signatures used in provenance studies are assumed to be representative of entire catchments from which the sediment was derived, but the extent to which hydraulic sorting can bias provenance interpretations is poorly constrained. Sediment and mineral sorting occurs with changes in hydraulic conditions driven by both allogenic and autogenic processes. Zircon is sorted from less dense minerals due to the difference in density, and any age dependence on zircon size could potentially bias provenance interpretations. In this study, a coupled paleohydraulic and geochemical provenance approach is used to identify changes in paleohydraulic conditions and relate them to spatial variations in provenance signatures from samples collected along an approximately time-correlative source-to-sink pathway in the Permian Cutler Group of the Paradox Basin. Samples proximal to the uplift have a paleoflow direction to the southwest. In the medial basin, paleocurrent direction indicates salt movement caused fluvial pathways divert to the north and northwest on the flanks of anticlines. Channel depth, flow velocity, and discharge calculations were derived from field measurements of grain size and dune and bar cross-stratification indicate that competency of the fluvial system decreased from proximal to the medial basin by up to a factor of 12. Based upon the paleohydraulic calculations, zircon size fractionation would occur along the transect such that the larger zircons are removed from the system prior to reaching the medial basin. Analysis of the size and age distribution of zircons from the proximal and distal fluvial system of the Cutler Group tests if this hydraulic sorting affects the expected Uncompahgre Uplift age distribution.

SDSS-IV MaNGA: global stellar population and gradients for about 2000 early-type and spiral galaxies on the mass-size plane

NASA Astrophysics Data System (ADS)

Li, Hongyu; Mao, Shude; Cappellari, Michele; Ge, Junqiang; Long, R. J.; Li, Ran; Mo, H. J.; Li, Cheng; Zheng, Zheng; Bundy, Kevin; Thomas, Daniel; Brownstein, Joel R.; Roman Lopes, Alexandre; Law, David R.; Drory, Niv

2018-05-01

We perform full spectrum fitting stellar population analysis and Jeans Anisotropic modelling of the stellar kinematics for about 2000 early-type galaxies (ETGs) and spiral galaxies from the MaNGA DR14 sample. Galaxies with different morphologies are found to be located on a remarkably tight mass plane which is close to the prediction of the virial theorem, extending previous results for ETGs. By examining an inclined projection (`the mass-size' plane), we find that spiral and early-type galaxies occupy different regions on the plane, and their stellar population properties (i.e. age, metallicity, and stellar mass-to-light ratio) vary systematically along roughly the direction of velocity dispersion, which is a proxy for the bulge fraction. Galaxies with higher velocity dispersions have typically older ages, larger stellar mass-to-light ratios and are more metal rich, which indicates that galaxies increase their bulge fractions as their stellar populations age and become enriched chemically. The age and stellar mass-to-light ratio gradients for low-mass galaxies in our sample tend to be positive (centre < outer), while the gradients for most massive galaxies are negative. The metallicity gradients show a clear peak around velocity dispersion log10 σe ≈ 2.0, which corresponds to the critical mass ˜3 × 1010 M⊙ of the break in the mass-size relation. Spiral galaxies with large mass and size have the steepest gradients, while the most massive ETGs, especially above the critical mass Mcrit ≳ 2 × 1011 M⊙, where slow rotator ETGs start dominating, have much flatter gradients. This may be due to differences in their evolution histories, e.g. mergers.

Crown structure and growth efficiency of red spruce in uneven-aged, mixed-species stands in Maine

Treesearch

Douglas A. Maguire; John C. Brissette; Lianhong. Gu

1998-01-01

Several hypotheses about the relationships among individual tree growth, tree leaf area, and relative tree size or position were tested with red spruce (Picea rubens Sarg.) growing in uneven-aged, mixed-species forests of south-central Maine, U.S.A. Based on data from 65 sample trees, predictive models were developed to (i)...

The Role of Pubertal Timing in What Adolescent Boys Do Online

ERIC Educational Resources Information Center

Skoog, Therese; Stattin, Hakan; Kerr, Margaret

2009-01-01

The aim of this study was to investigate associations between pubertal timing and boys' Internet use, particularly their viewing of pornography. We used a sample comprising of 97 boys in grade 8 (M age, 14.22 years) from two schools in a medium-sized Swedish town. This age should be optimal for differentiating early, on-time, and later-maturing…

Analysis of work ability and work-related physical activity of employees in a medium-sized business.

PubMed

Wilke, Christiane; Ashton, Philip; Elis, Tobias; Biallas, Bianca; Froböse, Ingo

2015-12-18

Work-related physical activity (PA) and work ability are of growing importance in modern working society. There is evidence for age- and job-related differences regarding PA and work ability. This study analyses work ability and work-related PA of employees in a medium-sized business regarding age and occupation. The total sample consists of 148 employees (116 men-78.38% of the sample-and 32 women, accounting for 21.62%; mean age: 40.85 ± 10.07 years). 100 subjects (67.57%) are white-collar workers (WC), and 48 (32.43%) are blue-collar workers (BC). Work ability is measured using the work ability index, and physical activity is obtained via the Global Physical Activity Questionnaire. Work ability shows significant differences regarding occupation (p = 0.001) but not regarding age. Further, significant differences are found for work-related PA concerning occupation (p < 0.0001), but again not for age. Overall, more than half of all subjects meet the current guidelines for physical activity. Work ability is rated as good, yet, a special focus should lie on the promotion during early and late working life. Also, there is still a lack of evidence on the level of work-related PA. Considering work-related PA could add to meeting current activity recommendations.

The Complex Nature of Family Support across the Lifespan: Implications for Psychological Well-being

PubMed Central

Fuller-Iglesias, Heather R.; Webster, Noah J.; Antonucci, Toni C.

2015-01-01

This study examines the complex role of family networks in shaping adult psychological well-being over time. We examine the unique and interactive longitudinal influences of family structure (i.e., composition and size) and negative family relationship quality on psychological well-being among young (aged 18-34), middle-aged (aged 35-49), and older adults (aged 50+). A sample of 881 adults (72% White; 26% Black) was drawn from the longitudinal Social Relations, Age and Health Study. Structural equation modeling indicated that among young and middle-aged adults, increasing family negativity was associated with increases in depressive symptoms over time. In contrast, among older adults, lowered proportion of family in network and an increasing number of family members in the network (i.e. family size) were associated with decreases in depressive symptoms. These findings were moderated by family negativity. Among older adults with low family negativity, having a lower proportion family and larger family size were associated with decreasing depressive symptoms, but there was no effect among those reporting high family negativity. Overall, these results contribute to an increased understanding of the complex, developmental nature of how family support influences well-being across the lifespan and highlights unique age differences. PMID:25602936

Lack of association between ectoparasite intensities and rabies virus neutralizing antibody seroprevalence in wild big brown bats (Eptesicus fuscus), Fort Collins, Colorado

USGS Publications Warehouse

Pearce, R.D.; O'Shea, T.J.; Shankar, V.; Rupprecht, C.E.

2007-01-01

Recently, bat ectoparasites have been demonstrated to harbor pathogens of potential importance to humans. We evaluated antirabies antibody seroprevalence and the presence of ectoparasites in big brown bats (Eptesicus fuscus) sampled in 2002 and 2003 in Colorado to investigate if an association existed between ectoparasite intensity and exposure to rabies virus (RV). We used logistic regression and Akaike's Information Criteria adjusted for sample size (AICc) in a post-hoc analysis to investigate the relative importance of three ectoparasite species, as well as bat colony size, year sampled, age class, colony size, and year interaction on the presence of rabies virus neutralizing antibodies (VNA) in serum of wild E. fuscus. We obtained serum samples and ectoparasite counts from big brown bats simultaneously in 2002 and 2003. Although the presence of ectoparasites (Steatonyssus occidentalis and Spinturnix bakeri) were important in elucidating VNA seroprevalence, their intensities were higher in seronegative bats than in seropositive bats, and the presence of a third ectoparasite (Cimex pilosellus) was inconsequential. Colony size and year sampled were the most important variables in these AICc models. These findings suggest that these ectoparasites do not enhance exposure of big brown bats to RV. ?? 2007 Mary Ann Liebert, Inc.

A New Approach of Juvenile Age Estimation using Measurements of the Ilium and Multivariate Adaptive Regression Splines (MARS) Models for Better Age Prediction.

PubMed

Corron, Louise; Marchal, François; Condemi, Silvana; Chaumoître, Kathia; Adalian, Pascal

2017-01-01

Juvenile age estimation methods used in forensic anthropology generally lack methodological consistency and/or statistical validity. Considering this, a standard approach using nonparametric Multivariate Adaptive Regression Splines (MARS) models were tested to predict age from iliac biometric variables of male and female juveniles from Marseilles, France, aged 0-12 years. Models using unidimensional (length and width) and bidimensional iliac data (module and surface) were constructed on a training sample of 176 individuals and validated on an independent test sample of 68 individuals. Results show that MARS prediction models using iliac width, module and area give overall better and statistically valid age estimates. These models integrate punctual nonlinearities of the relationship between age and osteometric variables. By constructing valid prediction intervals whose size increases with age, MARS models take into account the normal increase of individual variability. MARS models can qualify as a practical and standardized approach for juvenile age estimation. © 2016 American Academy of Forensic Sciences.

Reduction of Racial Disparities in Prostate Cancer

DTIC Science & Technology

2005-12-01

erectile dysfunction , and female sexual dysfunction ). Wherever possible, the questions and scales employed on BACH were selected from published...Methods. A racially and ethnically diverse community-based survey of adults aged 30-79 years in Boston, Massachusetts. The BACH survey has...recruited adults in three racial/ethnic groups: Latino, African American, and White using a stratified cluster sample. The target sample size is equally

Tree Data (TD)

Treesearch

Robert E. Keane

2006-01-01

The Tree Data (TD) methods are used to sample individual live and dead trees on a fixed-area plot to estimate tree density, size, and age class distributions before and after fire in order to assess tree survival and mortality rates. This method can also be used to sample individual shrubs if they are over 4.5 ft tall. When trees are larger than the user-specified...

Maintenance of phenotypic variation: Repeatability, heritability and size-dependent processes in a wild brook trout population

USGS Publications Warehouse

Letcher, B.H.; Coombs, J.A.; Nislow, K.H.

2011-01-01

Phenotypic variation in body size can result from within-cohort variation in birth dates, among-individual growth variation and size-selective processes. We explore the relative effects of these processes on the maintenance of wide observed body size variation in stream-dwelling brook trout (Salvelinus fontinalis). Based on the analyses of multiple recaptures of individual fish, it appears that size distributions are largely determined by the maintenance of early size variation. We found no evidence for size-dependent compensatory growth (which would reduce size variation) and found no indication that size-dependent survival substantially influenced body size distributions. Depensatory growth (faster growth by larger individuals) reinforced early size variation, but was relatively strong only during the first sampling interval (age-0, fall). Maternal decisions on the timing and location of spawning could have a major influence on early, and as our results suggest, later (>age-0) size distributions. If this is the case, our estimates of heritability of body size (body length=0.25) will be dominated by processes that generate and maintain early size differences. As a result, evolutionary responses to environmental change that are mediated by body size may be largely expressed via changes in the timing and location of reproduction. Published 2011. This article is a US Government work and is in the public domain in the USA.

Maternal characteristics versus egg size and energy density: do stocked lake trout in Lake Ontario experience premature reproductive senescence?

USGS Publications Warehouse

Lantry, B.F.; O'Gorman, R.; Machut, L.S.

2008-01-01

Observations from September 1994 and 1997 collections of hatchery-origin, mature female lake trout (Salvelinus namaycush) from Lake Ontario indicated that egg mass decreased with age, fueling the notion that stocked fish experienced premature reproductive senescence. Supplemental collections during September 2002 and November 2002-2004 were combined with the 1994 and 1997 samples to examine whether sample date or maternal age, body mass, condition (K), egg count, or strain were related to egg mass or energy content (percentage dry mass [%DM]). Body mass was correlated with egg mass for age ≥ 8 lake trout sampled in September, and egg count was correlated with egg mass for September age-6 lake trout only. Within each month, egg mass was not related to K or egg %DM, however, egg %DM was 1.52% greater (P ≤ 0.0247) in November than in September which is equivalent to a 110 cal/g difference. Samples were grouped for the three most abundant strains (Seneca, Superior, and Ontario) after finding no strain or year effects from our 1994 and 1997 samples and based on life history data from the literature and our assessment sampling. Further analysis indicated that September egg masses were greater for fish ages ≤ 6 than for fish ages ≥ 8. The age effect disappeared in November when mean egg mass across all ages (0.078 g) was greater than September means (P < 0.0005) for ages -5 (0.054 g), -6 (0.057 g) and ≥ 8 (0.041 g). Our results indicate that the decrease in egg mass with female age in September was not due to senescence, but to oogenesis being closer to completion in young age-5 and -6 fish than in older individuals.

The Violent Early Solar System, as Told by Sample Geochronology

NASA Technical Reports Server (NTRS)

Cohen, Barbara

2013-01-01

One of the legacies of the samples collected by the Apollo and Luna missions is the link forged between radiometric ages of rocks and relative ages according to stratigraphic relationships and impact crater size-frequency distributions. Our current understanding of the history of the inner solar system is based on the relative chronology of individual planets, tied to the absolute geochronology of the Moon via these important samples. Sample ages have enabled us to infer that impact-melt breccias from Apollo 14 and 15 record the formation of the Imbrium Basin, those from the highland massifs at Apollo 17 record the age of Serenitatis, those from the KREEP-poor Apollo 16 site record the age of Nectaris, and materials from Luna 24 record the age of Crisium. Ejecta from smaller and younger craters Copernicus and Tycho were sampled at Apollo 12 and 17, respectively, and local craters such as Cone at Apollo 14, and North Ray and South Ray at Apollo 16 were also sampled and ages determined for those events. Much of what we understand about the lunar impact flux is based on these ages. Samples from these nearside locations reveal a preponderance of impact-disturbed or recrystallized ages between 3.75 and 3.95 billion years. Argon and lead loss (and correlated disturbances in the Rb-Sr system) have been attributed to metamorphism of the lunar crust by an enormous number of impacts in a brief pulse of time, called the Lunar Cataclysm or Late Heavy Bombardment. Subsequent high-precision geochronometric analyses of Apollo samples and lunar highlands meteorites show a wider range of ages, but very few older than 4 Ga. The paucity of ancient impact melt rocks has been interpreted to mean that either that most impact basins formed at this time, or that ejecta from the large, near-side, young basins dominates the Apollo samples.

Evaluating change in bruise colorimetry and the effect of subject characteristics over time.

PubMed

Scafide, Katherine R N; Sheridan, Daniel J; Campbell, Jacquelyn; Deleon, Valerie B; Hayat, Matthew J

2013-09-01

Forensic clinicians are routinely asked to estimate the age of cutaneous bruises. Unfortunately, existing research on noninvasive methods to date bruises has been mostly limited to relatively small, homogeneous samples or cross-sectional designs. The purpose of this prospective, foundational study was to examine change in bruise colorimetry over time and evaluate the effects of bruise size, skin color, gender, and local subcutaneous fat on that change. Bruises were created by a controlled application of a paintball pellet to 103 adult, healthy volunteers. Daily colorimetry measures were obtained for four consecutive days using the Minolta Chroma-meter(®). The sample was nearly equal by gender and skin color (light, medium, dark). Analysis included general linear mixed modeling (GLMM). Change in bruise colorimetry over time was significant for all three color parameters (L*a*b*), the most notable changes being the decrease in red (a*) and increase in yellow (b*) starting at 24 h. Skin color was a significant predictor for all three colorimetry values but sex or subcutaneous fat levels were not. Bruise size was a significant predictor and moderator and may have accounted for the lack of effect of gender or subcutaneous fat. Study results demonstrated the ability to model the change in bruise colorimetry over time in a diverse sample of healthy adults. Multiple factors, including skin color and bruise size must be considered when assessing bruise color in relation to its age. This study supports the need for further research that could build the science to allow more accurate bruise age estimations.

Recent trend in family households in Beijing.

PubMed

Guo, Z; Guo, L

1997-01-01

This study examined trends in household size and age structure in Beijing, China, in 1995. Data were reliably obtained from the 1% sample survey of China. Findings indicate that the average size of a family household was 3.15 persons, that is, 0.050 persons fewer than the 3.20 from the 1990 Census. Children aged 0-14 years in each household averaged 0.04 fewer children during 1990-95. 80% of the decline in household size was due to decreases in the number of children. The percentage of single-family and single-person households declined. Three-person households were the only size group that increased (23.2-40.7%). The household headship (HH) rate for males increased dramatically between the ages of 20 and 30 years and stabilized after 35 years. The HH rate for women grew slowly and continuously until age 50 years and then stabilized. The gender gap in HH appeared at an early age and remained thereafter. The HH rate declined at older ages. The HH rate in Beijing, compared to the national rate, suggests relative gender equity in Beijing. As a child ages, the percentage of three-generation households declines and the percentage of two-generation households rises. As a child becomes an adult, the percentages of single-person households and single-couple households increase. Single-couple households decreased among the middle-aged. 67.4% of the elderly lived in two- or three-generation households. 31.4% of elderly lived in single-person/couple households. The percentage of elderly living with their children declined by 2 points during 1990-95.

Meta-analysis and systematic review of factors biasing the observed prevalence of congenitally missing teeth in permanent dentition excluding third molars.

PubMed

Rakhshan, Vahid

2013-10-01

No meta-analyses or systematic reviews have been conducted to evaluate numerous potential biasing factors contributing to the controversial results on congenitally missing teeth (CMT). We aimed to perform a rather comprehensive meta-analysis and systematic review on this subject. A thorough search was performed during September 2012 until April 2013 to find the available literature regarding CMT prevalence. Besides qualitatively discussing the literature, the meta-sample homogeneity, publication bias, and the effects of sample type, sample size, minimum and maximum ages of included subjects, gender imbalances, and scientific credit of the publishing journals on the reported CMT prevalence were statistically analyzed using Q-test, Egger regression, Spearman coefficient, Kruskal-Wallis, Welch t test (α=0.05), and Mann-Whitney U test (α=0.016, α=0.007). A total of 111 reports were collected. Metadata were heterogeneous (P=0.000). There was not a significant publication bias (Egger Regression P=0.073). Prevalence rates differed in different types of populations (Kruskal-Wallis P=0.001). Studies on orthodontic patients might report slightly (about 1%) higher prevalence (P=0.009, corrected α=0.016). Non-orthodontic dental patients showed a significant 2% decline [P=0.007 (Mann-Whitney U)]. Enrolling more males in researches might significantly reduce the observed prevalence (Spearman ρ=-0.407, P=0.001). Studies with higher minimums of subjects' age showed always slightly less CMT prevalence. This reached about -1.6% around the ages 10 to 13 and was significant for ages 10 to 12 (Welch t test P<0.05). There seems to be no limit over the maximum age (Welch t test P>0.2). Studies' sample sizes were correlated negatively with CMT prevalence (ρ=-0.250, P=0.009). It was not verified whether higher CMT rates have better chances of being published (ρ=0.132, P=0.177). CMT definition should be unified. Samples should be sex-balanced. Enrolling both orthodontic and dental patients in similar proportions might be preferable over sampling from each of those groups. Sampling from children over 12 years seems advantageous. Two or more observers should examine larger samples to reduce the false negative error tied with such samples.

POLYBROMINATED DIPHENYL ETHER (PBDE) LEVELS IN AN EXPANDED MARKET BASKET SURVEY OF UNITED STATES (U.S) FOOD AND ESTIMATED PBDE DIETARY INTAKE BY AGE AND SEX

EPA Science Inventory

This study enhances a previously reported U.S. market basket survey of food for polybrominated diphenyl ether (PBDE) levels with a larger sample size of 62 individual analyses for 13 congeners. In addition, it estimates levels of PBDE intake from food by gender and age for the U....

Young Children's Drawings of Plant Life: A Study Concerning the Use of Colours and Its Relationship with Age

ERIC Educational Resources Information Center

Villarroel, José Domingo

2016-01-01

This study examines the drawings that elementary grade school children make on the subject of plant life. More specifically, the pictorial elements drawn by children are analysed together with their colour choices and the size of coloured surfaces. Furthermore, the results are put into perspective with the age of the children in the sample. The…

Social Relations in Lebanon: Convoys Across the Life Course.

PubMed

Antonucci, Toni C; Ajrouch, Kristine J; Abdulrahim, Sawsan

2015-10-01

This study systematically analyzed convoys of social relations to investigate the ways in which gender and income shape patterns of social relations across the life course in Lebanon. Data were drawn from a representative sample of adults aged 18 and older in Greater Beirut, Lebanon (N = 500). Multiple linear regression and multilevel models were conducted to examine main and interactive effects of age, gender, and income on social relations. Findings indicate main effects of age, income, and gender on network structure and relationship quality. Older age was associated with larger network size, greater proportion of kin in network, higher positive and lower negative relationship quality. Higher income was associated with larger network size and decreased contact frequency. Female gender was also associated with decreased contact frequency. Gender interacted with income to influence network size and network composition. Higher income was associated with a larger network size and higher proportion of kin for women. Findings suggest diversity in the experience of social relations. Such nuance is particularly relevant to the Lebanese context where family is the main source of support in old age. Policy makers and program planners may need to refrain from viewing social relations simplistically. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pre-aging time dependence of microstructure and mechanical properties in nanostructured Al-2wt%Cu alloy

NASA Astrophysics Data System (ADS)

Azad, Bahram; Borhani, Ehsan

2016-03-01

This work is focused on the effect of pre-aging time on the properties of Al-2wt%Cu alloy processed by accumulative roll bonding (ARB) process. Following aged at 190 °C for 10 or 30 min, the samples were deformed up to a strain of 4.8 by the ARB process. The microstructure evolution was investigated by transmission electron microscope and electron backscattering diffraction analyzes. The results showed that the Al2Cu precipitates were formed with different sizes due to the different pre-aging times and the finer precipitates were more effective on the formation of high angle grain boundaries during the ARB process. The grain size of Aged-10 min and Aged-30 min specimens decreased to 400 nm and 420 nm, respectively, after 6 cycles of the ARB process. Also, the final texture after 6 cycles of the ARB process, shown in the {111} pole figure, were different depending on the starting microstructures. The mechanical properties of specimens were investigated by the Vickers microhardness measurements and the tensile tests. The results showed that the mechanical properties are affected by the starting microstructure. The mechanical properties of Aged-10 min specimen were different compared to Aged-30 min specimen due to the different size of the pre-existing precipitates. Although by continuing process, the precipitates were probably dissolved due to the heavy deformation.

College athletics, body size, and cancer mortality

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

Polednak, A.P.

Data are presented on mortality from neoplasms as determined from death certificates in a cohort of 8393 college men, according to athletic status in college. Major athletes (lettermen) died significantly more often from neoplasms than nonathletes. Mean age at death from neoplasms (underlying cause) was significantly lower in major athletes than in both minor athletes and nonathletes. After matching major athletes with nonathletes of comparable body size (height and weight), differences in proportional mortality and mean age at death from neoplasms persisted, although not statistically significant for the smaller samples. Correlation coefficients (Pearson r) and partial r's between weight inmore » college and age at death from neoplasms were negative but of low magnitude. Some possible explanations for the differences between major athletes and nonathletes are discussed.« less

National population size estimation of illicit drug users through the network scale-up method in 2013 in Iran.

PubMed

Nikfarjam, Ali; Shokoohi, Mostafa; Shahesmaeili, Armita; Haghdoost, Ali Akbar; Baneshi, Mohammad Reza; Haji-Maghsoudi, Saiedeh; Rastegari, Azam; Nasehi, Abbas Ali; Memaryan, Nadereh; Tarjoman, Termeh

2016-05-01

For a better understanding of the current situation of drug use in Iran, we utilized the network scale-up approach to estimate the prevalence of illicit drug use in the entire country. We implemented a self-administered, street-based questionnaire to 7535 passersby from the general public over 18 years of age by street based random walk quota sampling (based on gender, age and socio-economic status) from 31 provinces in Iran. The sample size in each province was approximately 400, ranging from 200 to 1000. In each province 75% of sample was recruited from the capital and the remaining 25% was recruited from one of the large cities of that province through stratified sampling. The questionnaire comprised questions on demographic information as well as questions to measure the total network size of participants as well as the network size in each of seven drug use groups including Opium, Shire (combination of Opium residue and pure opium), Crystal Methamphetamine, heroin/crack (which in Iranian context is a cocaine-free drug that mostly contains heroin, codeine, morphine and caffeine with or without other drugs), Hashish, Methamphetamine/LSD/ecstasy, and injecting drugs. The estimated size for each group was adjusted for transmission and barrier ratios. The most common type of illicit drug used was opium with the prevalence of 1500 per 100,000 population followed by shire (660), crystal methamphetamine (590), hashish (470), heroin/crack (350), methamphetamine, LSD and ecstasy (300) and injecting drugs (280). All types of substances were more common among men than women. The use of opium, shire and injecting drugs was more common in individuals over 30 whereas the use of stimulants and hashish was largest among individuals between 18 and 30 years of age. It seems that younger individuals and women are more desired to use new synthetic drugs such as crystal methamphetamine. Extending the preventive programs especially in youth as like as scaling up harm reduction services would be the main priorities in prevention and control of substance use in Iran. Because of poor service coverage and high stigma in women, more targeted programs in this affected population are needed. Copyright © 2016 Elsevier B.V. All rights reserved.

Synchrotron-based XRD from rat bone of different age groups.

PubMed

Rao, D V; Gigante, G E; Cesareo, R; Brunetti, A; Schiavon, N; Akatsuka, T; Yuasa, T; Takeda, T

2017-05-01

Synchrotron-based XRD spectra from rat bone of different age groups (w, 56 w and 78w), lumber vertebra at early stages of bone formation, Calcium hydroxyapatite (HAp) [Ca 10 (PO 4 ) 6 (OH) 2 ] bone fill with varying composition (60% and 70%) and bone cream (35-48%), has been acquired with 15keV synchrotron X-rays. Experiments were performed at Desy, Hamburg, Germany, utilizing the Resonant and Diffraction beamline (P9), with 15keV X-rays (λ=0.82666 A 0 ). Diffraction data were quantitatively analyzed using the Rietveld refinement approach, which allowed us to characterize the structure of these samples in their early stages. Hydroxyapatite, received considerable attention in medical and materials sciences, since these materials are the hard tissues, such as bone and teeth. Higher bioactivity of these samples gained reasonable interest for biological application and for bone tissue repair in oral surgery and orthopedics. The results obtained from these samples, such as phase data, crystalline size of the phases, as well as the degree of crystallinity, confirm the apatite family crystallizing in a hexagonal system, space group P6 3 /m with the lattice parameters of a=9.4328Å and c=6.8842Å (JCPDS card #09-0432). Synchrotron-based XRD patterns are relatively sharp and well resolved and can be attributed to the hexagonal crystal form of hydroxyapatite. All the samples were examined with scanning electron microscope at an accelerating voltage of 15kV. The presence of large globules of different sizes is observed, in small age groups of the rat bone (8w) and lumber vertebra (LV), as distinguished from, large age groups (56 and 78w) in all samples with different magnification, reflects an amorphous phase without significant traces of crystalline phases. Scanning electron microscopy (SEM) was used to characterize the morphology and crystalline properties of Hap, for all the samples, from 2 to 100μm resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Sampling Recommendations From the Influenza Virologic Surveillance Right Size Roadmap for Idaho.

PubMed

Rosenthal, Mariana; Anderson, Katey; Tengelsen, Leslie; Carter, Kris; Hahn, Christine; Ball, Christopher

2017-08-24

The Right Size Roadmap was developed by the Association of Public Health Laboratories and the Centers for Disease Control and Prevention to improve influenza virologic surveillance efficiency. Guidelines were provided to state health departments regarding representativeness and statistical estimates of specimen numbers needed for seasonal influenza situational awareness, rare or novel influenza virus detection, and rare or novel influenza virus investigation. The aim of this study was to compare Roadmap sampling recommendations with Idaho's influenza virologic surveillance to determine implementation feasibility. We calculated the proportion of medically attended influenza-like illness (MA-ILI) from Idaho's influenza-like illness surveillance among outpatients during October 2008 to May 2014, applied data to Roadmap-provided sample size calculators, and compared calculations with actual numbers of specimens tested for influenza by the Idaho Bureau of Laboratories (IBL). We assessed representativeness among patients' tested specimens to census estimates by age, sex, and health district residence. Among outpatients surveilled, Idaho's mean annual proportion of MA-ILI was 2.30% (20,834/905,818) during a 5-year period. Thus, according to Roadmap recommendations, Idaho needs to collect 128 specimens from MA-ILI patients/week for situational awareness, 1496 influenza-positive specimens/week for detection of a rare or novel influenza virus at 0.2% prevalence, and after detection, 478 specimens/week to confirm true prevalence is ≤2% of influenza-positive samples. The mean number of respiratory specimens Idaho tested for influenza/week, excluding the 2009-2010 influenza season, ranged from 6 to 24. Various influenza virus types and subtypes were collected and specimen submission sources were representative in terms of geographic distribution, patient age range and sex, and disease severity. Insufficient numbers of respiratory specimens are submitted to IBL for influenza laboratory testing. Increased specimen submission would facilitate meeting Roadmap sample size recommendations. ©Mariana Rosenthal, Katey Anderson, Leslie Tengelsen, Kris Carter, Christine Hahn, Christopher Ball. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 24.08.2017.

Evaluation of Sampling Recommendations From the Influenza Virologic Surveillance Right Size Roadmap for Idaho

PubMed Central

2017-01-01

Background The Right Size Roadmap was developed by the Association of Public Health Laboratories and the Centers for Disease Control and Prevention to improve influenza virologic surveillance efficiency. Guidelines were provided to state health departments regarding representativeness and statistical estimates of specimen numbers needed for seasonal influenza situational awareness, rare or novel influenza virus detection, and rare or novel influenza virus investigation. Objective The aim of this study was to compare Roadmap sampling recommendations with Idaho’s influenza virologic surveillance to determine implementation feasibility. Methods We calculated the proportion of medically attended influenza-like illness (MA-ILI) from Idaho’s influenza-like illness surveillance among outpatients during October 2008 to May 2014, applied data to Roadmap-provided sample size calculators, and compared calculations with actual numbers of specimens tested for influenza by the Idaho Bureau of Laboratories (IBL). We assessed representativeness among patients’ tested specimens to census estimates by age, sex, and health district residence. Results Among outpatients surveilled, Idaho’s mean annual proportion of MA-ILI was 2.30% (20,834/905,818) during a 5-year period. Thus, according to Roadmap recommendations, Idaho needs to collect 128 specimens from MA-ILI patients/week for situational awareness, 1496 influenza-positive specimens/week for detection of a rare or novel influenza virus at 0.2% prevalence, and after detection, 478 specimens/week to confirm true prevalence is ≤2% of influenza-positive samples. The mean number of respiratory specimens Idaho tested for influenza/week, excluding the 2009-2010 influenza season, ranged from 6 to 24. Various influenza virus types and subtypes were collected and specimen submission sources were representative in terms of geographic distribution, patient age range and sex, and disease severity. Conclusions Insufficient numbers of respiratory specimens are submitted to IBL for influenza laboratory testing. Increased specimen submission would facilitate meeting Roadmap sample size recommendations. PMID:28838883

Some effects of sex, age, and household structure on family drawings of Barbadian children.

PubMed

Payne, M A

1996-10-01

An analysis of the family drawings of a nonclinical sample of 502 Barbadian children aged 7-11 years is reported. The inclusion or omission of figures and the size and positioning of the figures of parents and self were examined with reference to sex, age, and household structure. The view that cultural values about the structure of the family unit and parental roles are reflected in children's representations of their parents in family drawings was supported.

Resource Input, Service Process and Resident Activity Indicators in a Welsh National Random Sample of Staffed Housing Services for People with Intellectual Disabilities

ERIC Educational Resources Information Center

Felce, David; Perry, Jonathan

2004-01-01

Background: The aims were to: (i) explore the association between age and size of setting and staffing per resident; and (ii) report resident and setting characteristics, and indicators of service process and resident activity for a national random sample of staffed housing provision. Methods: Sixty settings were selected randomly from those…

Evaluating morphometric body mass prediction equations with a juvenile human test sample: accuracy and applicability to small-bodied hominins.

PubMed

Walker, Christopher S; Yapuncich, Gabriel S; Sridhar, Shilpa; Cameron, Noël; Churchill, Steven E

2018-02-01

Body mass is an ecologically and biomechanically important variable in the study of hominin biology. Regression equations derived from recent human samples allow for the reasonable prediction of body mass of later, more human-like, and generally larger hominins from hip joint dimensions, but potential differences in hip biomechanics across hominin taxa render their use questionable with some earlier taxa (i.e., Australopithecus spp.). Morphometric prediction equations using stature and bi-iliac breadth avoid this problem, but their applicability to early hominins, some of which differ in both size and proportions from modern adult humans, has not been demonstrated. Here we use mean stature, bi-iliac breadth, and body mass from a global sample of human juveniles ranging in age from 6 to 12 years (n = 530 age- and sex-specific group annual means from 33 countries/regions) to evaluate the accuracy of several published morphometric prediction equations when applied to small humans. Though the body proportions of modern human juveniles likely differ from those of small-bodied early hominins, human juveniles (like fossil hominins) often differ in size and proportions from adult human reference samples and, accordingly, serve as a useful model for assessing the robustness of morphometric prediction equations. Morphometric equations based on adults systematically underpredict body mass in the youngest age groups and moderately overpredict body mass in the older groups, which fall in the body size range of adult Australopithecus (∼26-46 kg). Differences in body proportions, notably the ratio of lower limb length to stature, influence predictive accuracy. Ontogenetic changes in these body proportions likely influence the shift in prediction error (from under- to overprediction). However, because morphometric equations are reasonably accurate when applied to this juvenile test sample, we argue these equations may be used to predict body mass in small-bodied hominins, despite the potential for some error induced by differing body proportions and/or extrapolation beyond the original reference sample range. Copyright © 2017 Elsevier Ltd. All rights reserved.

Morphology Dependence of Stellar Age in Quenched Galaxies at Redshift ˜1.2: Massive Compact Galaxies Are Older than More Extended Ones

NASA Astrophysics Data System (ADS)

Williams, Christina C.; Giavalisco, Mauro; Bezanson, Rachel; Cappelluti, Nico; Cassata, Paolo; Liu, Teng; Lee, Bomee; Tundo, Elena; Vanzella, Eros

2017-04-01

We report the detection of morphology-dependent stellar age in massive quenched galaxies (QGs) at z ˜ 1.2. The sense of the dependence is that compact QGs are 0.5-2 Gyr older than normal-sized ones. The evidence comes from three different age indicators—{D}n4000, {{{H}}}δ , and fits to spectral synthesis models—applied to their stacked optical spectra. All age indicators consistently show that the stellar populations of compact QGs are older than those of their normal-sized counterparts. We detect weak [O II] emission in a fraction of QGs, and the strength of the line, when present, is similar between the two samples; however, compact galaxies exhibit a significantly lower frequency of [O II] emission than normal ones. Fractions of both samples are individually detected in 7 Ms Chandra X-ray images (luminosities ˜1040-1041 erg s-1). The 7 Ms stacks of nondetected galaxies show similarly low luminosities in the soft band only, consistent with a hot gas origin for the X-ray emission. While both [O II] emitters and nonemitters are also X-ray sources among normal galaxies, no compact galaxy with [O II] emission is an X-ray source, arguing against an active galactic nucleus (AGN) powering the line in compact galaxies. We interpret the [O II] properties as further evidence that compact galaxies are older and further along in the process of quenching star formation and suppressing gas accretion. Finally, we argue that the older age of compact QGs is evidence of progenitor bias: compact QGs simply reflect the smaller sizes of galaxies at their earlier quenching epoch, with stellar density most likely having nothing directly to do with cessation of star formation.

Estimating age of sea otters with cementum layers in the first premolar

USGS Publications Warehouse

Bodkin, James L.; Ames, J.A.; Jameson, R.J.; Johnson, A.M.; Matson, G.M.

1997-01-01

We assessed sources of variation in the use of tooth cementum layers to determine age by comparing counts in premolar tooth sections to known ages of 20 sea otters (Enhydra lutris). Three readers examined each sample 3 times, and the 3 readings of each sample were averaged by reader to provide the mean estimated age. The mean (SE) of known age sample was 5.2 years (1.0) and the 3 mean estimated ages were 7.0 (1.0), 5.9 (1.1) and, 4.4 (0.8). The proportion of estimates accurate to within +/- 1 year were 0.25, 0.55, and 0.65 and to within +/- 2 years 0.65, 0.80, and 0.70, by reader. The proportions of samples estimated with >3 years error were 0.20, 0.10, and 0.05. Errors as large as 7, 6, and 5 years were made among readers. In few instances did all readers uniformly provide either accurate (error 1 yr) counts. In most cases (0.85), 1 or 2 of the readers provided accurate counts. Coefficients of determination (R2) between known ages and mean estimated ages were 0.81, 0.87, and 0.87, by reader. The results of this study suggest that cementum layers within sea otter premolar teeth likely are deposited annually and can be used for age estimation. However, criteria used in interpreting layers apparently varied by reader, occasionally resulting in large errors, which were not consistent among readers. While large errors were evident for some individual otters, there were no differences between the known and estimated age-class distribution generated by each reader. Until accuracy can be improved, application of this ageing technique should be limited to sample sizes of at least 6-7 individuals within age classes of >/=1 year.

Association between Early Marriage and Intimate Partner Violence in India: A Focus on Youth from Bihar and Rajasthan

PubMed Central

Speizer, Ilene S.; Pearson, Erin

2013-01-01

The relationship between intimate partner violence (IPV) and early marriage is explored using the 2005-2006 India National Family Health Survey (NFHS-3). The NFHS-3 collected data from a representative sample of women and men in India with a large enough sample size to have a representative sample at the state level. The focus is on youth from Bihar and Rajasthan, two states with high IPV and early marriage. Multivariate logistic regression analyses demonstrate that women ages 20-24 who married before age eighteen, the legal age at marriage in India, are more likely to have ever experienced IPV in their lifetime and recently experienced IPV (in the last 12 months) than their counterparts who married later. The results were significant in Rajasthan but not in Bihar. To reduce IPV, targeted efforts must be made to decrease the proportion of India’s girls who are married under the legal age of marriage. PMID:20587462

Conodont (U Th)/He thermochronology: Initial results, potential, and problems

NASA Astrophysics Data System (ADS)

Peppe, Daniel J.; Reiners, Peter W.

2007-06-01

We performed He diffusion experiments and (U-Th)/He age determinations on conodonts from a variety of locations to explore the potential of conodont (U-Th)/He thermochronology to constrain thermal and exhumation histories of some sedimentary-rock dominated terrains. Based on two diffusion experiments and age results from some specimens, He diffusion in conodont elements appears to be similar to that in Durango apatite fragments of similar size, and closure temperatures are approximately 60-70 °C (for cooling rates of ˜ 10 °C/m.y.). (U-Th)/He ages of conodonts from some locations yield reproducible ages consistent with regional thermal history constraints and, in at least two cases, require a closure temperature lower than ˜ 80 °C. Other samples however, yield irreproducible ages, and in one case yield ages much younger than expected based on regional geologic considerations. These irreproducible samples show inverse correlations between parent nuclides and age consistent with late-stage open-system U-Th behavior.

The human urinary microbiome; bacterial DNA in voided urine of asymptomatic adults

PubMed Central

Lewis, Debbie A.; Brown, Richard; Williams, Jon; White, Paul; Jacobson, S. Kim; Marchesi, Julian R.; Drake, Marcus J.

2013-01-01

The urinary microbiome of healthy individuals and the way it alters with ageing have not been characterized and may influence disease processes. Conventional microbiological methods have limited scope to capture the full spectrum of urinary bacterial species. We studied the urinary microbiota from a population of healthy individuals, ranging from 26 to 90 years of age, by amplification of the 16S rRNA gene, with resulting amplicons analyzed by 454 pyrosequencing. Mid-stream urine (MSU) was collected by the “clean-catch” method. Quantitative PCR of 16S rRNA genes in urine samples, allowed relative enumeration of the bacterial loads. Analysis of the samples indicates that females had a more heterogeneous mix of bacterial genera compared to the male samples and generally had representative members of the phyla Actinobacteria and Bacteroidetes. Analysis of the data leads us to conclude that a “core” urinary microbiome could potentially exist, when samples are grouped by age with fluctuation in abundance between age groups. The study also revealed age-specific genera Jonquetella, Parvimonas, Proteiniphilum, and Saccharofermentans. In conclusion, conventional microbiological methods are inadequate to fully identify around two-thirds of the bacteria identified in this study. Whilst this proof-of-principle study has limitations due to the sample size, the discoveries evident in this sample data are strongly suggestive that a larger study on the urinary microbiome should be encouraged and that the identification of specific genera at particular ages may be relevant to pathogenesis of clinical conditions. PMID:23967406

The human urinary microbiome; bacterial DNA in voided urine of asymptomatic adults.

PubMed

Lewis, Debbie A; Brown, Richard; Williams, Jon; White, Paul; Jacobson, S Kim; Marchesi, Julian R; Drake, Marcus J

2013-01-01

The urinary microbiome of healthy individuals and the way it alters with ageing have not been characterized and may influence disease processes. Conventional microbiological methods have limited scope to capture the full spectrum of urinary bacterial species. We studied the urinary microbiota from a population of healthy individuals, ranging from 26 to 90 years of age, by amplification of the 16S rRNA gene, with resulting amplicons analyzed by 454 pyrosequencing. Mid-stream urine (MSU) was collected by the "clean-catch" method. Quantitative PCR of 16S rRNA genes in urine samples, allowed relative enumeration of the bacterial loads. Analysis of the samples indicates that females had a more heterogeneous mix of bacterial genera compared to the male samples and generally had representative members of the phyla Actinobacteria and Bacteroidetes. Analysis of the data leads us to conclude that a "core" urinary microbiome could potentially exist, when samples are grouped by age with fluctuation in abundance between age groups. The study also revealed age-specific genera Jonquetella, Parvimonas, Proteiniphilum, and Saccharofermentans. In conclusion, conventional microbiological methods are inadequate to fully identify around two-thirds of the bacteria identified in this study. Whilst this proof-of-principle study has limitations due to the sample size, the discoveries evident in this sample data are strongly suggestive that a larger study on the urinary microbiome should be encouraged and that the identification of specific genera at particular ages may be relevant to pathogenesis of clinical conditions.

Estimating age ratios and size of pacific walrus herds on coastal haulouts using video imaging.

PubMed

Monson, Daniel H; Udevitz, Mark S; Jay, Chadwick V

2013-01-01

During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance) to classify the sex and age of walruses hauled out on Alaska beaches in 2010-2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m(2) (std. err. = 0.02), herd size ranged from 8,300 to 19,400 (CV 0.03-0.06) and we documented ∼30,000 animals along ∼1 km of beach in 2011. Within the herds, dependent walruses (0-2 yr-olds) tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying) will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species.

Estimating age ratios and size of Pacific walrus herds on coastal haulouts using video imaging

USGS Publications Warehouse

Monson, Daniel H.; Udevitz, Mark S.; Jay, Chadwick V.

2013-01-01

During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance) to classify the sex and age of walruses hauled out on Alaska beaches in 2010–2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m2 (std. err. = 0.02), herd size ranged from 8,300 to 19,400 (CV 0.03–0.06) and we documented ~30,000 animals along ~1 km of beach in 2011. Within the herds, dependent walruses (0–2 yr-olds) tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying) will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species.

Estimating Age Ratios and Size of Pacific Walrus Herds on Coastal Haulouts using Video Imaging

PubMed Central

Monson, Daniel H.; Udevitz, Mark S.; Jay, Chadwick V.

2013-01-01

During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance) to classify the sex and age of walruses hauled out on Alaska beaches in 2010–2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m2 (std. err. = 0.02), herd size ranged from 8,300 to 19,400 (CV 0.03–0.06) and we documented ∼30,000 animals along ∼1 km of beach in 2011. Within the herds, dependent walruses (0–2 yr-olds) tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying) will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species. PMID:23936106

Considerations for successful cosmogenic 3He dating in accessory phases

NASA Astrophysics Data System (ADS)

Amidon, W. H.; Farley, K. A.; Rood, D. H.

2008-12-01

We have been working to develop cosmogenic 3He dating of phases other than the commonly dated olivine and pyroxene, especially apatite and zircon. Recent work by Dunai et al. underscores that cosmogenic 3He dating is complicated by 3He production via 6Li(n,α) 3H --> 3He. The reacting thermal neutrons can be produced from three distinct sources; nucleogenic processes (3Henuc), muon interactions (3Hemu), and by high-energy "cosmogenic" neutrons (3Hecn). Accurate cosmogenic 3He dating requires determination of the relative fractions of Li-derived and spallation derived 3He. An important complication for the fine-grained phases we are investigating is that both spallation and the 6Li reaction eject high energy particles, with consequences for redistribution of 3He among phases in a rock. Although shielded samples can be used to estimate 3Henuc, they do not conatin the 3Hecn component produced in the near surface. To calculate this component, we propose a procedure in which the bulk rock chemistry, helium closure age, 3He concentration, grain size and Li content of the target mineral are measured in a shielded sample. The average Li content of the adjacent minerals can then be calculated, which in turn allows calculation of the 3Hecn component in surface exposed samples of the same lithology. If identical grain sizes are used in the shielded and surface exposed samples, then "effective" Li can be calculated directly from the shielded sample, and it may not be necessary to measure Li at all. To help validate our theoretical understanding of Li-3He production, and to constrain the geologic contexts in which cosmogenic 3He dating with zircon and apatite is likely to be successful, results are presented from four different field locations. For example, results from ~18 Ky old moraines in the Sierra Nevada show that the combination of low Li contents and high closure ages (>50 My) creates a small 3Hecn component (2%) but a large 3Henuc component (40-70%) for zircon and apatite. In contrast the combination of high Li contents and a young closure age (0.6 My) in rhyolite from the Coso volcanic field leads to a large 3Hecn component (30%) and small 3Henuc component (5%) in zircon. Analysis of samples from a variety of lithologies shows that zircon and apatite tend to be low in Li (1-10 ppm), but are vulnerable to implantation of 3He from adjacent minerals due to their small grain size, especially from minerals like biotite and hornblende. This point is well illustrated by data from both the Sierra Nevada and Coso examples, in which there is a strong correlation between grain size and 3He concentration for zircons due to implantation. In contrast, very large zircons (150>125 um width) obtained from shielded samples of the Shoshone Falls rhyolite (SW Idaho) do not contain a significant implanted component. Thus, successful 3He dating of accessory phases requires low Li content (<10 ppm) in the target mineral and either 1) low Li in adjacent minerals, or 2) the use of large grain sizes (>100 um). In high-Li cases, the fraction of 3Henuc is minimized in samples with young helium closure ages or longer duration of exposure. However because the 3Hecn/3Hespall ratio is fixed for a given Li content, longer exposure will not reduce the fraction of 3Hecn.

Size-selective mortality of steelhead during freshwater and marine life stages related to freshwater growth in the Skagit River, Washington

USGS Publications Warehouse

Thompson, Jamie N.; Beauchamp, David A.

2014-01-01

We evaluated freshwater growth and survival from juvenile (ages 0–3) to smolt (ages 1–5) and adult stages in wild steelhead Oncorhynchus mykiss sampled in different precipitation zones of the Skagit River basin, Washington. Our objectives were to determine whether significant size-selective mortality (SSM) in steelhead could be detected between early and later freshwater stages and between each of these freshwater stages and returning adults and, if so, how SSM varied between these life stages and mixed and snow precipitation zones. Scale-based size-at-annulus comparisons indicated that steelhead in the snow zone were significantly larger at annulus 1 than those in the mixed rain–snow zone. Size at annuli 2 and 3 did not differ between precipitation zones, and we found no precipitation zone × life stage interaction effect on size at annulus. Significant freshwater and marine SSM was evident between the juvenile and adult samples at annulus 1 and between each life stage at annuli 2 and 3. Rapid growth between the final freshwater annulus and the smolt migration did not improve survival to adulthood; rather, it appears that survival in the marine environment may be driven by an overall higher growth rate set earlier in life, which results in a larger size at smolt migration. Efforts for recovery of threatened Puget Sound steelhead could benefit by considering that SSM between freshwater and marine life stages can be partially attributed to growth attained in freshwater habitats and by identifying those factors that limit growth during early life stages.

Body size of young Australians aged five to 16 years.

PubMed

Hitchcock, N E; Maller, R A; Gilmour, A I

1986-10-20

In 1983-1984, 4578 Perth primary and secondary schoolchildren were studied. The selected sample was broadly representative of the ethnic groups that make up the Perth population and of the different social ranks within that population. The age, sex, weight, height, country of birth of the child and the parents, and occupation of the father were recorded for each subject. Weight, height and body mass index (BMI) increased with age. Age and sex were the most important determinants of body size. However, children of lower social rank and those with a southern European background were over-represented among the overweight children (greater than the 90th centile for BMI), particularly in adolescence. Children with an Asian background who were 11 years of age and younger were over-represented among the underweight children (less than or equal to the 10th centile for BMI). Results from this study indicate a continuing, though small (1.5 cm to 1.6 cm), secular increase in height over the past 13 to 14 years.

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.

Generalist genes analysis of DNA markers associated with mathematical ability and disability reveals shared influence across ages and abilities

PubMed Central

2010-01-01

Background The Generalist Genes Hypothesis is based upon quantitative genetic findings which indicate that many of the same genes influence diverse cognitive abilities and disabilities across age. In a recent genome-wide association study of mathematical ability in 10-year-old children, 43 SNP associations were nominated from scans of pooled DNA, 10 of which were validated in an individually genotyped sample. The 4927 children in this genotyped sample have also been studied at 7, 9 and 12 years of age on measures of mathematical ability, as well as on other cognitive and learning abilities. Results Using these data we have explored the Generalist Genes Hypothesis by assessing the association of the available measures of ability at age 10 and other ages with two composite 'SNP-set' scores, formed from the full set of 43 nominated SNPs and the sub-set of 10 SNPs that were previously found to be associated with mathematical ability at age 10. Both SNP sets yielded significant associations with mathematical ability at ages 7, 9 and 12, as well as with reading and general cognitive ability at age 10. Conclusions Although effect sizes are small, our results correspond with those of quantitative genetic research in supporting the Generalist Genes Hypothesis. SNP sets identified on the basis of their associations with mathematical ability at age 10 show associations with mathematical ability at earlier and later ages and show associations of similar magnitude with reading and general cognitive ability. With small effect sizes expected in such complex traits, future studies may be able to capitalise on power by searching for 'generalist genes' using longitudinal and multivariate approaches. PMID:20602751

Increase in iodine deficiency disorder due to inadequate sustainability of supply of iodized salt in District Solan, Himachal Pradesh.

PubMed

Kapil, Umesh; Pandey, R M; Jain, Vandana; Kabra, Madhulika; Sareen, Neha; Bhadoria, Ajeet Singh; Vijay, Jyoti; Nigam, Sukirty; Khenduja, Preetika

2013-12-01

Himachal Pradesh is a known endemic area for iodine deficiency disorders. A study was conducted in district Solan with the objective of assessing the prevalence of iodine deficiency disorders in school-age children. Thirty clusters were selected by using the probability-proportionate-to-size cluster sampling methodology. Clinical examination of the thyroid of 1898 children in the age-group of 6-12 years was conducted. Urine and salt samples were collected. The total goiter rate was found to be 15.4%. Median urinary iodine excretion level was 62.5 μg/l. Only 39% of the salt samples had iodine content of ≥15 ppm. Mild iodine deficiency was present in the subjects studied.

A Scoping Review of Digital Gaming Research Involving Older Adults Aged 85 and Older.

PubMed

Marston, Hannah R; Freeman, Shannon; Bishop, Kristen A; Beech, Christian L

2016-06-01

Interest in the use of digital game technologies by older adults is growing across disciplines from health and gerontology to computer science and game studies. The objective of this scoping review was to examine research evidence involving the oldest old (persons 85 years of age or greater) and digital game technology. PubMed, CINHAL, and Scopus were searched, and 46 articles were included in this review. Results highlighted that 60 percent of articles were published in gerontological journals, whereas only 8.7 percent were published in computer science journals. No studies focused directly on the oldest old population. Few studies included sample sizes greater than 100 participants. Seven primary and 34 secondary themes were identified, of which Hardware Technology and Assessment were the most common. Existing evidence demonstrates the paucity of studies engaging older adults 85 years of age and above regarding the use of digital gaming and highlights a new understudied cohort for further research focus. Recommendations for future research include intentional recruitment and proportionate representation of participants ≥85 years of age, large sample sizes, and explicit mention of specific numbers of participants ≥85 years of age, which are necessary to advance knowledge in this area. Integrating a rigorous and robust mixed-methods approach including theoretical perspectives would lend itself to further in-depth understanding and knowledge generation in this field.

Management implications of long-term tree growth and mortality rates: A modeling study of big-leaf mahogany (Swietenia macrophylla) in the Brazilian Amazon

Treesearch

C.M. Free; R.M. Landis; J. Grogan; M.D. Schulze; M. Lentini; O. Dunisch; NO-VALUE

2014-01-01

Knowledge of tree age-size relationships is essential towards evaluating the sustainability of harvest regulations that include minimum diameter cutting limits and fixed-length cutting cycles. Although many tropical trees form annual growth rings and can be aged from discs or cores, destructive sampling is not always an option for valuable or threatened species. We...

Complement pathway biomarkers and age-related macular degeneration

PubMed Central

Gemenetzi, M; Lotery, A J

2016-01-01

In the age-related macular degeneration (AMD) ‘inflammation model', local inflammation plus complement activation contributes to the pathogenesis and progression of the disease. Multiple genetic associations have now been established correlating the risk of development or progression of AMD. Stratifying patients by their AMD genetic profile may facilitate future AMD therapeutic trials resulting in meaningful clinical trial end points with smaller sample sizes and study duration. PMID:26493033

Age-dependent changes of the normal human spine during adulthood.

PubMed

Rühli, F J; Müntener, M; Henneberg, M

2005-01-01

The impact of aging on the morphology of the osseous spine is still debated. Clinical studies usually record combined aging effects, as well as age-related degenerative changes. The aim of this study was to determine the impact of (degeneration-independent) aging on the morphology of the osseous human spine during adulthood. Various osseous dimensions of human spinal landmarks at all major vertebral levels have been assessed in macroscopically normal Swiss skeletons (N = 71), with historically known sex and age at death, as well as in larger Central European skeletal samples (N = 277) with anthropologically determined individual age and sex. All measurements were correlated with individual age (or age group) by linear regression and analyzed separately for each sex. Only few osseous spinal dimensions, and only in men, correlate significantly with individual age. Generally, the significant dimensions show an increase in size during adulthood. Similar tendencies, but with significant alterations of spinal measurements in women as well, can be found in the larger samples with anthropologically determined sex and age group. Increase of certain spinal dimensions found in this study may be a reflection of an increase in the robustness of individuals with age. Because of the absence of a significant secular alteration of stature within the well-recorded sample, we exclude secular change in body dimensions as a major bias. Copyright 2005 Wiley Periodicals, Inc

Age and growth of the whitefish in Lake Superior

USGS Publications Warehouse

Dryer, William R.

1963-01-01

The average annual commercial production of whitefish in the U.S. waters of Lake Superior dropped from 2,194,000 pounds in 1879-1908 to 504,000 pounds in 1911-59. The modern production, though far below the earlier, has accounted for more than 10 percent of the total value of the fishery in all but one of the last 20 years. Data are given on growth rate, age and year-class composition, size distribution, and length-weight relation of 1,800 fish collected in 1957-59 at Bayfield, Wis., and Marquette, Whitefish Point, and Dollar Settlement, Mich. Studies of the body-scale relation, sex ratio, and age and size at maturity were limited to fish collected at Bayfield. The age composition and mean age varied widely by port and year of capture. Oldest fish were those of the 1957 Bayfield samples which were dominated by age group VII and averaged 5.5 years old. The youngest were from Whitefish Point in 1959; age-group III was dominant, and the mean age was 3.2 years. The evidence on the strength of year classes was not clear-cut, but it was obvious that fluctuations in stocks of different areas were largely independent. The percentage of legal-size fish (17 inches or longer) in age groups ranged widely; only 8.6 percent of the V group were legal in the 1957 Bayfield collections, whereas 100 percent of fish of the same age were legal in the 1957-59 collections from Whitefish Point. The weight of whitefish in the combined samples increased as the 3.2408 power of the length. The growth rate from the fastest to the slowest growing stocks ranked as follows: Whitefish Point; Dollar Settlement and Marquette (fish from the two ports reversed ranks after 3 years); Bayfield. The major differences in growth in length among the various stocks occurred during the first years of life. Beyond the fifth year the annual increments were nearly the same in all stocks. The whitefish from Whitefish Point, Dollar Settlement, and Marquette are among the fastest growing in the Great Lakes. The differences among the Lake Superior stocks in age and year-class composition, and in growth rate offer convincing evidence that populations of different areas are entirely independent. The sexes were almost equally represented (51.5 percent males) in the combined Bayfield samples, but males were scarce in age groups older than VIII. Whitefish from Bayfield shorter than 14.5 inches were immature and those larger than 17.4 inches were mature. The youngest mature fish belonged to age-group V,and all older than the VII group were mature.

Normal limits in relation to age, body size and gender of two-dimensional echocardiographic aortic root dimensions in persons ≥15 years of age.

PubMed

Devereux, Richard B; de Simone, Giovanni; Arnett, Donna K; Best, Lyle G; Boerwinkle, Eric; Howard, Barbara V; Kitzman, Dalane; Lee, Elisa T; Mosley, Thomas H; Weder, Alan; Roman, Mary J

2012-10-15

Nomograms to predict normal aortic root diameter for body surface area (BSA) in broad ranges of age have been widely used but are limited by lack of consideration of gender effects, jumps in upper limits of aortic diameter among age strata, and data from older teenagers. Sinus of Valsalva diameter was measured by American Society of Echocardiography convention in normal-weight, nonhypertensive, nondiabetic subjects ≥15 years old without aortic valve disease from clinical or population-based samples. Analyses of covariance and linear regression with assessment of residuals identified determinants and developed predictive models for normal aortic root diameter. In 1,207 apparently normal subjects ≥15 years old (54% women), aortic root diameter was 2.1 to 4.3 cm. Aortic root diameter was strongly related to BSA and height (r = 0.48 for the 2 comparisons), age (r = 0.36), and male gender (+2.7 mm adjusted for BSA and age, p <0.001 for all comparisons). Multivariable equations using age, gender, and BSA or height predicted aortic diameter strongly (R = 0.674 for the 2 comparisons, p <0.001) with minimal relation of residuals to age or body size: for BSA 2.423 + (age [years] × 0.009) + (BSA [square meters] × 0.461) - (gender [1 = man, 2 = woman] × 0.267), SEE 0.261 cm; for height 1.519 + (age [years] × 0.010) + (height [centimeters] × 0.010) - (gender [1 = man, 2 = woman] × 0.247), SEE 0.215 cm. In conclusion, aortic root diameter is larger in men and increases with body size and age. Regression models incorporating body size, age, and gender are applicable to adolescents and adults without limitations of previous nomograms. Copyright © 2012 Elsevier Inc. All rights reserved.

No Association between Variation in Longevity Candidate Genes and Aging-related Phenotypes in Oldest-old Danes.

PubMed

Soerensen, Mette; Nygaard, Marianne; Debrabant, Birgit; Mengel-From, Jonas; Dato, Serena; Thinggaard, Mikael; Christensen, Kaare; Christiansen, Lene

2016-06-01

In this study we explored the association between aging-related phenotypes previously reported to predict survival in old age and variation in 77 genes from the DNA repair pathway, 32 genes from the growth hormone 1/ insulin-like growth factor 1/insulin (GH/IGF-1/INS) signalling pathway and 16 additional genes repeatedly considered as candidates for human longevity: APOE, APOA4, APOC3, ACE, CETP, HFE, IL6, IL6R, MTHFR, TGFB1, SIRTs 1, 3, 6; and HSPAs 1A, 1L, 14. Altogether, 1,049 single nucleotide polymorphisms (SNPs) were genotyped in 1,088 oldest-old (age 92-93 years) Danes and analysed with phenotype data on physical functioning (hand grip strength), cognitive functioning (mini mental state examination and a cognitive composite score), activity of daily living and self-rated health. Five SNPs showed association to one of the phenotypes; however, none of these SNPs were associated with a change in the relevant phenotype over time (7 years of follow-up) and none of the SNPs could be confirmed in a replication sample of 1,281 oldest-old Danes (age 94-100). Hence, our study does not support association between common variation in the investigated longevity candidate genes and aging-related phenotypes consistently shown to predict survival. It is possible that larger sample sizes are needed to robustly reveal associations with small effect sizes. Copyright © 2016 Elsevier Inc. All rights reserved.

Size variation in early human mandibles and molars from Klasies River, South Africa: comparison with other middle and late Pleistocene assemblages and with modern humans.

PubMed

Royer, Danielle F; Lockwood, Charles A; Scott, Jeremiah E; Grine, Frederick E

2009-10-01

Previous studies of the Middle Stone Age human remains from Klasies River have concluded that they exhibited more sexual dimorphism than extant populations, but these claims have not been assessed statistically. We evaluate these claims by comparing size variation in the best-represented elements at the site, namely the mandibular corpora and M(2)s, to that in samples from three recent human populations using resampling methods. We also examine size variation in these same elements from seven additional middle and late Pleistocene sites: Skhūl, Dolní Vestonice, Sima de los Huesos, Arago, Krapina, Shanidar, and Vindija. Our results demonstrate that size variation in the Klasies assemblage was greater than in recent humans, consistent with arguments that the Klasies people were more dimorphic than living humans. Variation in the Skhūl, Dolní Vestonice, and Sima de los Huesos mandibular samples is also higher than in the recent human samples, indicating that the Klasies sample was not unusual among middle and late Pleistocene hominins. In contrast, the Neandertal samples (Krapina, Shanidar, and Vindija) do not evince relatively high mandibular and molar variation, which may indicate that the level of dimorphism in Neandertals was similar to that observed in extant humans. These results suggest that the reduced levels of dimorphism in Neandertals and living humans may have developed independently, though larger fossil samples are needed to test this hypothesis.

Accurate aging of juvenile salmonids using fork lengths

USGS Publications Warehouse

Sethi, Suresh; Gerken, Jonathon; Ashline, Joshua

2017-01-01

Juvenile salmon life history strategies, survival, and habitat interactions may vary by age cohort. However, aging individual juvenile fish using scale reading is time consuming and can be error prone. Fork length data are routinely measured while sampling juvenile salmonids. We explore the performance of aging juvenile fish based solely on fork length data, using finite Gaussian mixture models to describe multimodal size distributions and estimate optimal age-discriminating length thresholds. Fork length-based ages are compared against a validation set of juvenile coho salmon, Oncorynchus kisutch, aged by scales. Results for juvenile coho salmon indicate greater than 95% accuracy can be achieved by aging fish using length thresholds estimated from mixture models. Highest accuracy is achieved when aged fish are compared to length thresholds generated from samples from the same drainage, time of year, and habitat type (lentic versus lotic), although relatively high aging accuracy can still be achieved when thresholds are extrapolated to fish from populations in different years or drainages. Fork length-based aging thresholds are applicable for taxa for which multiple age cohorts coexist sympatrically. Where applicable, the method of aging individual fish is relatively quick to implement and can avoid ager interpretation bias common in scale-based aging.

[Sequential sampling plans to Orthezia praelonga Douglas (Hemiptera: Sternorrhyncha, Ortheziidae) in citrus].

PubMed

Costa, Marilia G; Barbosa, José C; Yamamoto, Pedro T

2007-01-01

The sequential sampling is characterized by using samples of variable sizes, and has the advantage of reducing sampling time and costs if compared to fixed-size sampling. To introduce an adequate management for orthezia, sequential sampling plans were developed for orchards under low and high infestation. Data were collected in Matão, SP, in commercial stands of the orange variety 'Pêra Rio', at five, nine and 15 years of age. Twenty samplings were performed in the whole area of each stand by observing the presence or absence of scales on plants, being plots comprised of ten plants. After observing that in all of the three stands the scale population was distributed according to the contagious model, fitting the Negative Binomial Distribution in most samplings, two sequential sampling plans were constructed according to the Sequential Likelihood Ratio Test (SLRT). To construct these plans an economic threshold of 2% was adopted and the type I and II error probabilities were fixed in alpha = beta = 0.10. Results showed that the maximum numbers of samples expected to determine control need were 172 and 76 samples for stands with low and high infestation, respectively.

Seasonal dynamics in community structure, abundance, body size and sex ratio in two species of Neotropical annual fishes.

PubMed

Lanés, L E K; Godoy, R S; Maltchik, L; Polačik, M; Blažek, R; Vrtílek, M; Reichard, M

2016-11-01

Seven ephemeral pools on the coastal plain of southern Brazil were found to be inhabited by three annual and 22 non-annual fish species. Two common annual species (Austrolebias minuano and Cynopoecilus fulgens) exhibited clear seasonal dynamics, with the appearance of young fishes in the austral autumn (May to June) and a decline in abundance over the seasonal cycle. The third annual species, Austrolebias wolterstorffii, was rare. No seasonal dynamics were observed in non-annual fishes. The relative abundance of non-annual fishes compared with annual fishes increased over the seasonal cycle, but they coexisted widely. The size structure of annual fishes suggested the presence of a single age cohort in most pools though a second age cohort was registered in one pool in August, coinciding with a large flooding. Strong sexual dimorphism in body size was found in C. fulgens throughout the seasonal cycle, while no sexual dimorphism in body size was found in A. minuano. Female-biased sex ratios were recorded in both common annual fish species in the last three sampling dates (in spring), but not during the first two sampling dates (in winter). The natural lifespan of annual fishes was <8 months. Annual fishes disappeared before habitat desiccation in half of the pools, while non-annual fishes were still present. © 2016 The Fisheries Society of the British Isles.

Validation of daily ring deposition in the otoliths of age-0 channel catfish

USGS Publications Warehouse

Sakaris, P.C.; Irwin, E.R.

2008-01-01

We developed and validated methods for estimating the daily age of age-0 channel catfish Ictalurus punctatus. Two clutches of channel catfish eggs were hatched in the laboratory; subsequently, one was stocked in a 186-m2 earthen nursery pond and the other in a 757-L outdoor circular tank. Before stocking, subsamples of fish were collected at swim-up and 3 d after swim-up to evaluate early ring formation. Fish were sampled from the pond and tank on eight occasions ranging from 30 to 119 d posthatch. Distinct differences in early ring formation were found between yolk sac and free-swimming larval stages. Mean ring count and known age were closely related for tank- and pond-raised fish, indicating that daily ring deposition occurred in the otoliths of age-0 channel catfish up to 119 d posthatch. The accuracy of daily age estimation was similar between tank and pond samples, and daily ring counts were considerably accurate up to 60 d posthatch. Pond-raised fish were more difficult to age than tank-raised fish, which we attributed to ring compression resulting from slower growth among pond-raised fish after 30 d. The total length of tank- and pond-raised fish was positively related to otolith size; however, the slopes of the relationships between fish length and otolith radius were different between treatments. Therefore, we could not confirm that the relationship between fish length and otolith size was directly proportional for age-0 channel catfish. We encourage researchers to use this aging technique to determine how abiotic and biotic factors influence early life history characteristics and ultimately the population dynamics of catfishes (Ictaluridae). ?? Copyright by the American Fisheries Society 2008.

Deliberate self-harm in older adults: a review of the literature from 1995 to 2004.

PubMed

Chan, Jenifer; Draper, Brian; Banerjee, Sube

2007-08-01

The prevention of suicide is a national and international policy priority. Old age is an important predictor of completed suicide. Suicide rates in old age differ markedly from country to country but there is a general trend towards increasing rates with increasing age. In 1996 Draper reviewed critically the evidence on attempted suicide in old age in the 10 years between 1985 and 1994. The review highlighted a need for prospective controlled studies in older people with more representative samples as well as studies examining the interaction of risk factors, precipitants, motivations, psychopathology and response to treatment. The aim of this paper is to update this review and to summarise the advances in our understanding of DSH in later life. We have critically reviewed relevant studies published between 1995 and 2004 to summarise the advances in our understanding of factors associated with deliberate self-harm in later life. The main advances in understanding have been to clarify the effect of personality and cultural factors, service utilisation pre and post attempt, and the (lesser) impact of socio-economic status and physical illness. Methodological weaknesses continue to include inadequate sample sizes performed on highly selected populations, inconsistent age criteria and lack of informant data on studies relating to role of personality. Future studies should include prospective, cross-cultural research with adequate sample sizes and which are population-based. Such approaches might confirm or refute the results generated to date and improve knowledge on factors such as the biological correlates of deliberate self-harm, service utilisation, costs and barriers to health care, and the interaction of these factors. Intervention studies to elucidate the impact of modifying these factors and of specific treatment packages are also needed.

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.

Age-Related Changes in Pharyngeal Lumen Size: A Retrospective MRI Analysis.

PubMed

Molfenter, Sonja M; Amin, M R; Branski, R C; Brumm, J D; Hagiwara, M; Roof, S A; Lazarus, C L

2015-06-01

Age-related loss of muscle bulk and strength (sarcopenia) is often cited as a potential mechanism underlying age-related changes in swallowing. Our goal was to explore this phenomenon in the pharynx, specifically, by measuring pharyngeal wall thickness and pharyngeal lumen area in a sample of young versus older women. MRI scans of the neck were retrospectively reviewed from 60 women equally stratified into three age groups (20s, 60s, 70+). Four de-identified slices were extracted per scan for randomized, blinded analysis: one mid-sagittal and three axial slices were selected at the anterior inferior border of C2 and C3, and at the pit of the vallecula. Pixel-based measures of pharyngeal wall thickness and pharyngeal lumen area were completed using ImageJ and then converted to metric units. Measures of pharyngeal wall thickness and pharyngeal lumen area were compared between age groups with one-way ANOVAs using Sidak adjustments for post-hoc pairwise comparisons. A significant main effect for age was observed across all variables whereby pharyngeal wall thickness decreased and pharyngeal lumen area increased with advancing age. Pairwise comparisons revealed significant differences between 20s versus 70+ for all variables and 20s versus 60s for all variables except those measured at C2. Effect sizes ranged from 0.54 to 1.34. Consistent with existing sacropenia literature, the pharyngeal muscles appear to atrophy with age and consequently, the size of the pharyngeal lumen increases.

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.

Trophy Hunting and Sustainability: Temporal Dynamics in Trophy Quality and Harvesting Patterns of Wild Herbivores in a Tropical Semi-Arid Savanna Ecosystem.

PubMed

Muposhi, Victor K; Gandiwa, Edson; Bartels, Paul; Makuza, Stanley M; Madiri, Tinaapi H

2016-01-01

The selective nature of trophy hunting may cause changes in desirable phenotypic traits in harvested species. A decline in trophy size of preferred species may reduce hunting destination competitiveness thus compromising the sustainability of trophy hunting as a conservation tool. We explored the trophy quality and trends in harvesting patterns (i.e., 2004-2015) of Cape buffalo (Syncerus caffer), African elephant (Loxodonta africana), greater kudu (Tragelaphus strepsiceros) and sable (Hippotragus niger) in Matetsi Safari Area, northwest Zimbabwe. We used long-term data on horn and tusk size, age, quota size allocation and offtake levels of selected species. To analyse the effect of year, area and age on the trophy size, quota size and offtake levels, we used linear mixed models. One sample t-test was used to compare observed trophy size with Safari Club International (SCI) minimum score. Trophy sizes for Cape buffalo and African elephant were below the SCI minimum score. Greater kudu trophy sizes were within the minimum score threshold whereas sable trophy sizes were above the SCI minimum score between 2004 and 2015. Age at harvest for Cape buffalo, kudu and sable increased whilst that of elephant remained constant between 2004 and 2015. Quota size allocated for buffalo and the corresponding offtake levels declined over time. Offtake levels of African elephant and Greater kudu declined whilst the quota size did not change between 2004 and 2015. The quota size for sable increased whilst the offtake levels fluctuated without changing for the period 2004-2015. The trophy size and harvesting patterns in these species pose a conservation and management dilemma on the sustainability of trophy hunting in this area. We recommend: (1) temporal and spatial rotational resting of hunting areas to create refuge to improve trophy quality and maintenance of genetic diversity, and (2) introduction of variable trophy fee pricing system based on trophy size.

Development of food photographs for use with children aged 18 months to 16 years: Comparison against weighed food diaries - The Young Person's Food Atlas (UK).

PubMed

Foster, Emma; Hawkins, Adrian; Barton, Karen L; Stamp, Elaine; Matthews, John N S; Adamson, Ashley J

2017-01-01

Traditional dietary assessment methods, used in the UK, such as weighed food diaries impose a large participant burden, often resulting in difficulty recruiting representative samples and underreporting of energy intakes. One approach to reducing the burden placed on the participant is to use portion size assessment tools to obtain an estimate of the amount of food consumed, removing the need to weigh all foods. An age range specific food atlas was developed for use in assessing children's dietary intakes. The foods selected and portion sizes depicted were derived from intakes recorded during the UK National Diet and Nutrition Surveys of children aged 1.5 to 16 years. Estimates of food portion sizes using the food atlas were compared against 4-day weighed intakes along with in-school / nursery observations, by the research team. Interviews were conducted with parents the day after completion of the diary, and for children aged 4 to 16 years, also with the child. Mean estimates of portion size consumed were within 7% of the weight of food recorded in the weighed food diary. The limits of agreement were wide indicating high variability of estimates at the individual level but the precision increased with increasing age. For children 11 years and over, agreement with weighed food diaries, was as good as that of their parents in terms of total weight of food consumed and of intake of energy and key nutrients. The age appropriate food photographs offer an alternative to weighed intakes for dietary assessment with children.

Effects of the aging temperature and stress relaxation conditions on γ‧ precipitation in Inconel X-750

NASA Astrophysics Data System (ADS)

Ha, Jeong Won; Seong, Baek Seok; Jeong, Hi Won; Choi, Yoon Suk; Kang, Namhyun

2015-02-01

Inconel X-750 is a Ni-based precipitation-hardened superalloy typically used in springs designed for high-temperature applications such as the hold-down springs in nuclear power plants. γ‧ is a major precipitate in X-750 alloys which affects the strength, creep resistance, and stress relaxation properties of the spring. In this study, a solution-treated X-750 wire coiled into a spring was used that was aged at various temperatures and submitted to stress relaxation tests with and without loading. Small angle neutron scattering was employed to quantify the size and volume fraction of γ‧ phase in the springs as a function of the aging temperature and the application of a load during stress relaxation. The volume fraction of γ‧ precipitates increased in the specimen aged at 732 °C following stress relaxation at 500 °C for 300 h. However, the mean size of the precipitates in the samples was not affected by stress relaxation. The specimen aged at the lower temperature (620 °C) contained a smaller γ‧ volume fraction and gained a smaller fraction of γ‧ during stress relaxation compared with the sample aged at the higher temperature (732 °C). The smaller increase in the γ‧ volume fraction for the sample aged at 620 °C was associated with a larger increase in the M23C6 secondary carbide content during relaxation. The Cr depletion zone around the secondary carbides raises the solubility of γ‧ thereby decreasing the volume fraction of γ‧ precipitates in Inconel X-750. In terms of stress relaxation, a larger increase in the γ‧ volume fraction was measured with loading rather than without. This is probably associated with the dislocation accumulation generated under loading that facilitate the nucleation and growth of heterogeneous γ‧ phase due to enhanced diffusion.

Relative age and birthplace effect in Japanese professional sports: a quantitative evaluation using a Bayesian hierarchical Poisson model.

PubMed

Ishigami, Hideaki

2016-01-01

Relative age effect (RAE) in sports has been well documented. Recent studies investigate the effect of birthplace in addition to the RAE. The first objective of this study was to show the magnitude of the RAE in two major professional sports in Japan, baseball and soccer. Second, we examined the birthplace effect and compared its magnitude with that of the RAE. The effect sizes were estimated using a Bayesian hierarchical Poisson model with the number of players as dependent variable. The RAEs were 9.0% and 7.7% per month for soccer and baseball, respectively. These estimates imply that children born in the first month of a school year have about three times greater chance of becoming a professional player than those born in the last month of the year. Over half of the difference in likelihoods of becoming a professional player between birthplaces was accounted for by weather conditions, with the likelihood decreasing by 1% per snow day. An effect of population size was not detected in the data. By investigating different samples, we demonstrated that using quarterly data leads to underestimation and that the age range of sampled athletes should be set carefully.

The Violent Early Solar System, as Told by Lunar Sample Geochronology

NASA Technical Reports Server (NTRS)

Cohen, Barbara

2012-01-01

One of the legacies of the samples collected by the Apollo and Luna missions is the link forged between radiometric ages of rocks and relative ages according to stratigraphic relationships and impact crater size-frequency distributions. Our current understanding of the history of the inner solar system is based on the relative chronology of individual planets, tied to the absolute geochronology of the Moon via these important samples. Samples from these nearside locations reveal a preponderance of impact-disturbed or recrystallized ages between 3.75 and 3.95 billion years. Argon and lead loss (and correlated disturbances in the Rb-Sr system) have been attributed to metamorphism of the lunar crust by an enormous number of impacts in a brief pulse of time, called the Lunar Cataclysm or Late Heavy Bombardment. Subsequent high-precision geochronometric analyses of Apollo samples and lunar highlands meteorites show a wider range of ages, but very few older than 4 Ga. The paucity of ancient impact melt rocks has been interpreted to mean that either that most impact basins formed at this time, or that ejecta from the large, near-side, young basins dominates the Apollo samples. Selenochronology is getting more complicated: new results question meaning of sample ages, crater counts, crater production functions, and the solar system itself. Improved geological mapping of lunar geologic units and boundaries using multiple remote sensing datasets. High-resolution image-based crater counting of discrete geologic units and relating them to location. Improved understanding of the regolith thickness and its global variation (GRAIL). Tying the sampling of impact-melt rocks to the lunar impact flux. Using improved techniques (magnetic fields, diffusion studies, isotopic analysis) on existing samples. New sample return from benchmark craters, particularly SPA, which appears in 2013 Decadal Survey.

2009 Spawning cisco investigations in the Canadian waters of Lake Superior

USGS Publications Warehouse

Yule, Daniel L.; Cholwek, Gary A.; Evrard, Lori M.; E. Berglund,; K.I. Cullis,

2010-01-01

We sampled with acoustics (AC) and midwater trawls (MT) to determine cisco abundance in Lake Superior’s Thunder and Black bays during 8-14 November, 2009. Total abundance of spawning-size (≥ 250 mm total length) ciscoes was estimated at 6.25 million in Thunder Bay and 1.12 million in Black Bay. Exploitation fractions of market-size (≥ age 6) females from Thunder and Black bays for 2009 were estimated at 7.1% and 11.3%, respectively; below the recommended maximum annual harvest of 15% recently adopted by Lake Superior fisheries managers. Given Thunder Bay spawner densities are on a downward trajectory, and recruitment since the 2003 year-class has been low, it is likely the exploitation fractions will increase in the future. After 2010, the Ontario Ministry of Natural Resources (OMNR) will carry on the AC program as a management activity. It is likely suspended experimental gill net (GN) samples will be used to ground truth future AC samples. In 2009, we characterized the length and age structure of Thunder Bay ciscoes using both MT samples and GN samples. Females represented 49% of the MT catch, but only 39% in GN samples. Catching a smaller proportion of females in GN samples resulted in a lower female population estimate and a higher estimated exploitation fraction (10.4%) compared to MT samples (7.1%). Experimental gill net effort was limited to 10-11.8 m water column depths where midwater trawl samples also caught roughly 40% females. Ciscoes ≥ age 17 (≥ 1992 year class) were common in Black Bay, but rare in Thunder Bay suggesting: 1) the stocks may be distinct; and 2) total mortality of ciscoes returning to spawn in Black Bay in recent years has been lower than ciscoes returning to Thunder Bay. Our mid-November 2009 effort to assess the Black Bay stock by sampling outside of the 3 bay in the lake proper was deemed successful, but this should be confirmed by sampling the Black Bay region during both mid- and late-November 2010.

Biomass of open-grown Virginia pine

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

Madgwick, H.A.I.; Olah, F.D.; Burkhart, H.E.

1977-03-01

Five open-grown Pinus virginiana trees ranging from 1.05 to 15.78 m tall were destructively sampled and the data used to obtain relationships between tree size and biomass to estimate dry matter production. The ratio of foliage to above-ground woody biomass decreased with tree age from 0.4 for a 7-year-old tree to 0.05 for a 39-year-old tree. Needle longevity increased with tree age. 5 references.

Demographic Structure, Sex Ratio and Growth Rates of Southern Bluefin Tuna (Thunnus maccoyii) on the Spawning Ground

PubMed Central

Farley, Jessica H.; Eveson, J. Paige; Davis, Tim L. O.; Andamari, Retno; Proctor, Craig H.; Nugraha, Budi; Davies, Campbell R.

2014-01-01

The demographics of the southern bluefin tuna (SBT) Thunnus maccoyii spawning stock were examined through a large-scale monitoring program of the Indonesian longline catch on the spawning ground between 1995 and 2012. The size and age structure of the spawning population has undergone significant changes since monitoring began. There has been a reduction in the relative abundance of larger/older SBT in the catch since the early 2000s, and a corresponding decrease in mean length and age, but there was no evidence of a significant truncation of the age distribution. Pulses of young SBT appear in the catches in the early- and mid-2000s and may be the first evidence of increased recruitment into the spawning stock since 1995. Fish in these two recruitment pulses were spawned around 1991 and 1997. Size-related variations in sex ratio were also observed with female bias for fish less than 170 cm FL and male bias for fish greater than 170 cm FL. This trend of increasing proportion of males with size above 170 cm FL is likely to be related to sexual dimorphism in growth rates as male length-at-age is greater than that for females after age 10 years. Mean length-at-age of fish aged 8–10 years was greater for both males and females on the spawning ground than off the spawning ground, suggesting that size may be the dominant factor determining timing of maturation in SBT. In addition to these direct results, the data and samples from this program have been central to the assessment and management of this internationally harvested stock. PMID:24797529

Exercise-associated DNA methylation change in skeletal muscle and the importance of imprinted genes: a bioinformatics meta-analysis.

PubMed

Brown, William M

2015-12-01

Epigenetics is the study of processes--beyond DNA sequence alteration--producing heritable characteristics. For example, DNA methylation modifies gene expression without altering the nucleotide sequence. A well-studied DNA methylation-based phenomenon is genomic imprinting (ie, genotype-independent parent-of-origin effects). We aimed to elucidate: (1) the effect of exercise on DNA methylation and (2) the role of imprinted genes in skeletal muscle gene networks (ie, gene group functional profiling analyses). Gene ontology (ie, gene product elucidation)/meta-analysis. 26 skeletal muscle and 86 imprinted genes were subjected to g:Profiler ontology analysis. Meta-analysis assessed exercise-associated DNA methylation change. g:Profiler found four muscle gene networks with imprinted loci. Meta-analysis identified 16 articles (387 genes/1580 individuals) associated with exercise. Age, method, sample size, sex and tissue variation could elevate effect size bias. Only skeletal muscle gene networks including imprinted genes were reported. Exercise-associated effect sizes were calculated by gene. Age, method, sample size, sex and tissue variation were moderators. Six imprinted loci (RB1, MEG3, UBE3A, PLAGL1, SGCE, INS) were important for muscle gene networks, while meta-analysis uncovered five exercise-associated imprinted loci (KCNQ1, MEG3, GRB10, L3MBTL1, PLAGL1). DNA methylation decreased with exercise (60% of loci). Exercise-associated DNA methylation change was stronger among older people (ie, age accounted for 30% of the variation). Among older people, genes exhibiting DNA methylation decreases were part of a microRNA-regulated gene network functioning to suppress cancer. Imprinted genes were identified in skeletal muscle gene networks and exercise-associated DNA methylation change. Exercise-associated DNA methylation modification could rewind the 'epigenetic clock' as we age. CRD42014009800. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

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

K-Ar constraints on fluid-rock interaction and dissolution-precipitation events within the actively creeping shear zones from SAFOD cores

NASA Astrophysics Data System (ADS)

Ali, S.; Hemming, S. R.; Torgersen, T.; Fleisher, M. Q.; Cox, S. E.; Stute, M.

2009-12-01

The San Andreas Fault Observatory at Depth (SAFOD) was drilled to study the physical and chemical processes responsible for faulting and earthquake generation along an active, plate-bounding fault at depth. SAFOD drill cores show multiple zones of alteration and deformation due to fluid-rock interaction in the fault rocks(Schleicher et al. 2008). In context of fluid studies in the SAFZ, noble gas and potassium measurements were performed on solid samples of sedimentary rocks obtained from drill cores across the fault (3050-4000m-MD). We used a combination of 40Ar/39Ar and K-Ar methods on crushed samples of mudrock with variable amounts of visible slickensides to constrain the degree of resetting of the K-Ar system across the San Andreas Fault zone. 40Ar/39Ar was analyzed from small fragments (sand sized grains) while K-Ar was measured in crushed bulk rock samples (100-250 mg for Ar, and 5-10 mg for K analyses). The apparent 40Ar/39Ar ages based on single step laser fusion of small fragments corresponding to the detrital component in the coarse fraction, show varying ages ranging from the provenance age to <13Ma. Although more data are needed to make detailed comparisons, the apparent K-Ar ages of bulk samples in the fault zone are biased toward authigenic materials contained in the fine fraction, similar to the 40Ar/39Ar ages reported for mineralogical separates from very fine size fractions of samples obtained from 3065.98m-MD and 3294.89m-MD (Schleicher et al., submitted to Geology). The small samples measured for 40Ar/39Ar show scatter in the apparent ages, generally bracketing the bulk ages. However they are picked from sieved portions of the samples, and it is likely that there may be a loss of the younger (finer) material. Detrital provenance ages appear to be 50-60Ma in the Pacific Plate, and 100Ma in the North American Plate. 40Ar/39Ar ages within the SAFZ, as defined by geophysical logs (3200-3400m MD), are dominated by apparent detrital ages of ˜100Ma. More work is needed to test whether this is a real provenance age, or if there could be some systematic process that could lead to age bias towards older values. We observe nearly complete resetting of K-Ar ages, indicating that the K content is dominated by newly formed authigenic minerals as a result of fluid rock interaction in the SAFZ. Because the authigenic minerals are subject to successive dissolution-precipitation events over a range of time (3 to 0 Ma) and because the detrital component may not be fully reset, the K-Ar apparent ages (<300,000 years) in the SAFZ provide a maximum age on the resetting event. Similar trends of relatively young ages across the SAFZ compared to the surrounding country rock in the Pacific and North American Plates are also observed in the apparent fluid ‘ages’, corresponding to the fluid event responsible for the fluid-rock interaction in the fault (Ali et al. this session).

Airframe integrity based on Bayesian approach

NASA Astrophysics Data System (ADS)

Hurtado Cahuao, Jose Luis

Aircraft aging has become an immense challenge in terms of ensuring the safety of the fleet while controlling life cycle costs. One of the major concerns in aircraft structures is the development of fatigue cracks in the fastener holes. A probabilistic-based method has been proposed to manage this problem. In this research, the Bayes' theorem is used to assess airframe integrity by updating generic data with airframe inspection data while such data are compiled. This research discusses the methodology developed for assessment of loss of airframe integrity due to fatigue cracking in the fastener holes of an aging platform. The methodology requires a probability density function (pdf) at the end of SAFE life. Subsequently, a crack growth regime begins. As the Bayesian analysis requires information of a prior initial crack size pdf, such a pdf is assumed and verified to be lognormally distributed. The prior distribution of crack size as cracks grow is modeled through a combined Inverse Power Law (IPL) model and lognormal relationships. The first set of inspections is used as the evidence for updating the crack size distribution at the various stages of aircraft life. Moreover, the materials used in the structural part of the aircrafts have variations in their properties due to their calibration errors and machine alignment. A Matlab routine (PCGROW) is developed to calculate the crack distribution growth through three different crack growth models. As the first step, the material properties and the initial crack size are sampled. A standard Monte Carlo simulation is employed for this sampling process. At the corresponding aircraft age, the crack observed during the inspections, is used to update the crack size distribution and proceed in time. After the updating, it is possible to estimate the probability of structural failure as a function of flight hours for a given aircraft in the future. The results show very accurate and useful values related to the reliability and integrity of airframes in aging aircrafts. Inspection data shown in this dissertation are not the actual data from known aircrafts and are only used to demonstrate the methodologies.

African Baobabs with False Inner Cavities: The Radiocarbon Investigation of the Lebombo Eco Trail Baobab

PubMed Central

Patrut, Adrian; Woodborne, Stephan; von Reden, Karl F.; Hall, Grant; Hofmeyr, Michele; Lowy, Daniel A.; Patrut, Roxana T.

2015-01-01

The article reports the radiocarbon investigation results of the Lebombo Eco Trail tree, a representative African baobab from Mozambique. Several wood samples collected from the large inner cavity and from the outer part of the tree were investigated by AMS radiocarbon dating. According to dating results, the age values of all samples increase from the sampling point with the distance into the wood. For samples collected from the cavity walls, the increase of age values with the distance into the wood (up to a point of maximum age) represents a major anomaly. The only realistic explanation for this anomaly is that such inner cavities are, in fact, natural empty spaces between several fused stems disposed in a ring-shaped structure. We named them false cavities. Several important differences between normal cavities and false cavities are presented. Eventually, we dated other African baobabs with false inner cavities. We found that this new architecture enables baobabs to reach large sizes and old ages. The radiocarbon date of the oldest sample was 1425 ± 24 BP, which corresponds to a calibrated age of 1355 ± 15 yr. The dating results also show that the Lebombo baobab consists of five fused stems, with ages between 900 and 1400 years; these five stems build the complete ring. The ring and the false cavity closed 800–900 years ago. The results also indicate that the stems stopped growing toward the false cavity over the past 500 years. PMID:25621989

Efficacy and safety of tadalafil 5 mg once daily in the treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia in men aged ≥75 years: integrated analyses of pooled data from multinational, randomized, placebo-controlled clinical studies.

PubMed

Oelke, Matthias; Wagg, Adrian; Takita, Yasushi; Büttner, Hartwig; Viktrup, Lars

2017-05-01

To assess efficacy and safety of tadalafil in men aged ≥75 years with lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH) and additional safety in men aged ≥75 years with erectile dysfunction (ED). We conducted an integrated analysis of 12 phase II-III randomized, double-blind and/or open-label extension studies to evaluate short-term (12-26 weeks) efficacy and short- and longer-term (42-52 weeks) safety in men aged <75 years vs men aged ≥75 years. All men received once-daily tadalafil 5 mg or placebo. The efficacy outcome was International Prostate Symptom Score (IPSS). Safety measurements included treatment-emergent adverse events (TEAEs), adverse events (AEs) leading to discontinuation, serious AEs (SAEs), and cardiovascular AEs. All analyses were intention-to-treat. Changes from baseline to efficacy endpoint and differences in changes between treatment groups were estimated as least-squares means using analysis of covariance models. Change in the mean IPSS was significantly different in men aged <75 years vs those aged ≥75 years across tadalafil and placebo groups (treatment-by-age interaction P = 0.034). Tadalafil was not statistically significantly better than placebo in men aged ≥75 years, but effect size varied between studies. Maintenance of efficacy with tadalafil was observed across age groups. Short-term tadalafil safety findings for men aged <75 vs ≥75 years included: TEAEs (52 [33.8%] vs 503 [30.1%]), AEs leading to discontinuation (3 [1.9%] vs 50 [3.0%]), SAEs (4 [2.6%] vs 15 [0.9%]) and cardiovascular AEs (4 [2.6%] vs 30 [1.8%]). Long-term tadalafil safety data did not reveal clinically relevant differences between age groups. Limitations include exclusion of men with serious co-existing conditions and limited sample sizes of men aged ≥75 years. Efficacy with once-daily tadalafil 5 mg in the treatment of LUTS/BPH differed between men aged <75 vs ≥75 years, with significant efficacy in the <75-year age group. The older age group had more concomitant diseases and used more drugs, which may have reduced efficacy. The small sample size precluded uni-/multivariate analyses to assess plausible interference from confounding factors. Tadalafil had a reassuring safety profile and no evidence of increased cardiovascular AEs in aging men. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.

Stochastic Sampling in the IMF of Galactic Open Clusters

NASA Astrophysics Data System (ADS)

Kay, Christina; Hancock, M.; Canalizo, G.; Smith, B. J.; Giroux, M. L.

2010-01-01

We sought observational evidence of the effects of stochastic sampling of the initial mass function by investigating the integrated colors of a sample of Galactic open clusters. In particular we looked for scatter in the integrated (V-K) color as previous research resulted in little scatter in the (U-B) and (B-V) colors. Combining data from WEBDA and 2MASS we determined three different colors for 287 open clusters. Of these clusters, 39 have minimum uncertainties in age and formed a standard set. A plot of the (V-K) color versus age showed much more scatter than the (U-B) versus age. We also divided the sample into two groups based on a lowest luminosity limit which is a function of age and V magnitude. We expected the group of clusters fainter than this limit to show more scatter than the brighter group. Assuming the published ages, we compared the reddening corrected observed colors to those predicted by Starburst99. The presence of stochastic sampling should increase scatter in the distribution of the differences between observed and model colors of the fainter group relative to the brighter group. However, we found that K-S tests cannot rule out that the distribution of color difference for the brighter and fainter sets come from the same parent distribution. This indistinguishabilty may result from uncertainties in the parameters used to define the groups. This result constrains the size of the effects of stochastic sampling of the initial mass function.

Implications of Extreme Life Span in Clonal Organisms: Millenary Clones in Meadows of the Threatened Seagrass Posidonia oceanica

PubMed Central

Arnaud-Haond, Sophie; Duarte, Carlos M.; Diaz-Almela, Elena; Marbà, Núria; Sintes, Tomas; Serrão, Ester A.

2012-01-01

The maximum size and age that clonal organisms can reach remains poorly known, although we do know that the largest natural clones can extend over hundreds or thousands of metres and potentially live for centuries. We made a review of findings to date, which reveal that the maximum clone age and size estimates reported in the literature are typically limited by the scale of sampling, and may grossly underestimate the maximum age and size of clonal organisms. A case study presented here shows the occurrence of clones of slow-growing marine angiosperm Posidonia oceanica at spatial scales ranging from metres to hundreds of kilometres, using microsatellites on 1544 sampling units from a total of 40 locations across the Mediterranean Sea. This analysis revealed the presence, with a prevalence of 3.5 to 8.9%, of very large clones spreading over one to several (up to 15) kilometres at the different locations. Using estimates from field studies and models of the clonal growth of P. oceanica, we estimated these large clones to be hundreds to thousands of years old, suggesting the evolution of general purpose genotypes with large phenotypic plasticity in this species. These results, obtained combining genetics, demography and model-based calculations, question present knowledge and understanding of the spreading capacity and life span of plant clones. These findings call for further research on these life history traits associated with clonality, considering their possible ecological and evolutionary implications. PMID:22312426

The Relationship of Age to Personal Network Size, Relational Multiplexity, and Proximity to Alters in the Western United States

PubMed Central

Smith, Emily J.; Marcum, Christopher S.; Boessen, Adam; Almquist, Zack W.; Hipp, John R.; Nagle, Nicholas N.

2015-01-01

Objectives. This study examines the association of age and other sociodemographic variables with properties of personal networks; using samples of individuals residing in the rural western United States and the City of Los Angeles, we evaluate the degree to which these associations vary with geographical context. For both samples, we test the hypothesis that age is negatively associated with network size (i.e., degree) and positively associated with network multiplexity (the extent of overlap) on 6 different relations: core discussion members, social activity participants, emergency contacts, neighborhood safety contacts, job informants, and kin. We also examine the relationship between age and spatial proximity to alters. Method. Our data consist of a large-scale, spatially stratified egocentric network survey containing information about respondents and those to whom they are tied. We use Poisson regression to test our hypothesis regarding degree while adjusting for covariates, including education, gender, race, and self-reported sense of neighborhood belonging. We use multiple linear regression to test our hypotheses on multiplexity and distance to alters. Results. For both rural and urban populations, we find a nonmonotone association between age and numbers of core discussants and emergency contacts, with rural populations also showing nonmonotone associations for social activity partners and kin. These nonmonotone relationships show a peak in expected degree at midlife, followed by an eventual decline. We find a decline in degree among the elderly for all relations in both populations. Age is positively associated with distance to nonhousehold alters for the rural population, although residential tenure is associated with shorter ego-alter distances in both rural and urban settings. Additionally, age is negatively associated with network multiplexity for both populations. Discussion. Although personal network size ultimately declines with age, we find that increases for some relations extend well into late-midlife and most elders still maintain numerous contacts across diverse relations. The evidence we present suggests that older people tap into an wider variety of different network members for different types of relations than do younger people. This is true even for populations in rural settings, for whom immediate access to potential alters is more limited. PMID:25324292

Particle Morphology and Size Results from the Smoke Aerosol Measurement Experiment-2

NASA Technical Reports Server (NTRS)

Urban, David L.; Ruff, Gary A.; Greenberg, Paul S.; Fischer, David; Meyer, Marit; Mulholland, George; Yuan, Zeng-Guang; Bryg, Victoria; Cleary, Thomas; Yang, Jiann

2012-01-01

Results are presented from the Reflight of the Smoke Aerosol Measurement Experiment (SAME-2) which was conducted during Expedition 24 (July-September 2010). The reflight experiment built upon the results of the original flight during Expedition 15 by adding diagnostic measurements and expanding the test matrix. Five different materials representative of those found in spacecraft (Teflon, Kapton, cotton, silicone rubber and Pyrell) were heated to temperatures below the ignition point with conditions controlled to provide repeatable sample surface temperatures and air flow. The air flow past the sample during the heating period ranged from quiescent to 8 cm/s. The smoke was initially collected in an aging chamber to simulate the transport time from the smoke source to the detector. This effective transport time was varied by holding the smoke in the aging chamber for times ranging from 11 to 1800 s. Smoke particle samples were collected on Transmission Electron Microscope (TEM) grids for post-flight analysis. The TEM grids were analyzed to observe the particle morphology and size parameters. The diagnostics included a prototype two-moment smoke detector and three different measures of moments of the particle size distribution. These moment diagnostics were used to determine the particle number concentration (zeroth moment), the diameter concentration (first moment), and the mass concentration (third moment). These statistics were combined to determine the diameter of average mass and the count mean diameter and, by assuming a log-normal distribution, the geometric mean diameter and the geometric standard deviations can also be calculated. Overall the majority of the average smoke particle sizes were found to be in the 200 nm to 400 nm range with the quiescent cases producing some cases with substantially larger particles.

Italy of censuses.

PubMed

Rey, G M

1983-06-01

To supplement census data on Italy's economy, Istat conducted a sample survey of 2% of households. This paper reports survey findings in 3 areas: age structure of the population, employment and unemployment patterns by region, and structure of the productive system. Those over age 65 years have increased from 11% of the population in 1971 to 13% in 1981 and are forecast to constitute 14.5% in 1991. Women accounted for 51.3% of the total population in 1981 but 58.5% of those over age 65. 12% of households have a member over age 75. The 0-14 year age group has declined from 24.4% of the population in 1971 to 21.5% in 1981 and is projected to comprise 17.4% in 1991. The labor force activity rate was 39.8% in 1981. Unemployment was set at 14.7% in the census sample compared with 9.1% in Istat's quarterly survey of the labor force. 60% of the difference between these 2 figures was accounted for by Campania, Sicily, Puglia, Calabria, and Latium. These 5 regions, which account for only 30% of total employment, are the areas with the most acute employment problems and highest proportions of casual employment in agriculture and traditional services. Agriculture accounted for 22% of total unemployment, construction for 18.5%, and traditional industry for 14%--percentages that are higher than the share of total employment represented by these sectors. In the South, 20.4% of employment is in agriculture, 18.1% in industry, 12.6% in construction, and 48.9% in services. The average worker in the South supports 3.3 persons compared with 2.5 persons in the North. Survey results indicate a substantial shift in the sectoral composition of employment as well as a change in the size of productive units. There has been an increase in the highly specialized components of the economy, including services to firms. The average size of factories has declined, with a proliferation of small and medium sized units. These findings suggest a need to broaden and deepen Italy's industrial base. Also needed is a consistent plan for labor and capital accumulation. The growth of medium sized firms should be supported until they reach a size compatible with investment and technical progress, thereby permitting greater employment and productivity.

Herbivorous insect response to group selection cutting in a southeastern bottomland hardwood forest

Treesearch

Michael D. Ulyshen; James L. Hanula; Scott Horn; John C. Kilgo; Christopher E. Moorman

2005-01-01

Malaise and pitfall traps were used to sample herbivorous insects in canopy gaps created by group-selection cutting in a bottomland hardwood forest in South Carolina. The traps were placed at the centers, edges, and in the forest adjacent to gaps of different sizes (0.13, 0.26, and 0.50 ha) and ages (1 and 7 yr old) during four sampling periods in 2001. Overall, the...

Molecular-Size-Separated Brown Carbon Absorption for Biomass-Burning Aerosol at Multiple Field Sites.

PubMed

Di Lorenzo, Robert A; Washenfelder, Rebecca A; Attwood, Alexis R; Guo, Hongyu; Xu, Lu; Ng, Nga L; Weber, Rodney J; Baumann, Karsten; Edgerton, Eric; Young, Cora J

2017-03-21

Biomass burning is a known source of brown carbon aerosol in the atmosphere. We collected filter samples of biomass-burning emissions at three locations in Canada and the United States with transport times of 10 h to >3 days. We analyzed the samples with size-exclusion chromatography coupled to molecular absorbance spectroscopy to determine absorbance as a function of molecular size. The majority of absorption was due to molecules >500 Da, and these contributed an increasing fraction of absorption as the biomass-burning aerosol aged. This suggests that the smallest molecular weight fraction is more susceptible to processes that lead to reduced light absorption, while larger-molecular-weight species may represent recalcitrant brown carbon. We calculate that these large-molecular-weight species are composed of more than 20 carbons with as few as two oxygens and would be classified as extremely low volatility organic compounds (ELVOCs).

Combined effect of pulse density and grid cell size on predicting and mapping aboveground carbon in fast‑growing Eucalyptus forest plantation using airborne LiDAR data

Treesearch

Carlos Alberto Silva; Andrew Thomas Hudak; Carine Klauberg; Lee Alexandre Vierling; Carlos Gonzalez‑Benecke; Samuel de Padua Chaves Carvalho; Luiz Carlos Estraviz Rodriguez; Adrian Cardil

2017-01-01

LiDAR measurements can be used to predict and map AGC across variable-age Eucalyptus plantations with adequate levels of precision and accuracy using 5 pulses m− 2 and a grid cell size of 5 m. The promising results for AGC modeling in this study will allow for greater confidence in comparing AGC estimates with varying LiDAR sampling densities for Eucalyptus plantations...

Early lexical characteristics of toddlers with cleft lip and palate.

PubMed

Hardin-Jones, Mary; Chapman, Kathy L

2014-11-01

Objective : To examine development of early expressive lexicons in toddlers with cleft palate to determine whether they differ from those of noncleft toddlers in terms of size and lexical selectivity. Design : Retrospective. Patients : A total of 37 toddlers with cleft palate and 22 noncleft toddlers. Main Outcome Measures : The groups were compared for size of expressive lexicon reported on the MacArthur Communicative Development Inventory and the percentage of words beginning with obstruents and sonorants produced in a language sample. Differences between groups in the percentage of word initial consonants correct on the language sample were also examined. Results : Although expressive vocabulary was comparable at 13 months of age for both groups, size of the lexicon for the cleft group was significantly smaller than that for the noncleft group at 21 and 27 months of age. Toddlers with cleft palate produced significantly more words beginning with sonorants and fewer words beginning with obstruents in their spontaneous speech samples. They were also less accurate when producing word initial obstruents compared with the noncleft group. Conclusions : Toddlers with cleft palate demonstrate a slower rate of lexical development compared with their noncleft peers. The preference that toddlers with cleft palate demonstrate for words beginning with sonorants could suggest they are selecting words that begin with consonants that are easier for them to produce. An alternative explanation might be that because these children are less accurate in the production of obstruent consonants, listeners may not always identify obstruents when they occur.

Fertility desires and fertility outcomes.

PubMed

Bracher, M; Santow, G

1991-05-01

An Australian 1-in-1000 national probability sample conducted in 1986 yielded 2547 women aged 20-59 who provided detailed life histories on marital unions, childbearing, and contraception. Age specific fertility rates, desired family size, differentials in desired family size, desired fertility and achieved fertility, and sequential family building are examined. The results indicate that the desired family size at 1st marriage has declined only slightly over the past 30 years. 3 children are generally desired, and ver few desire 2. The constance of fertility desires in contrasted with the fertilitydecline to below replacement levels. Several reasons are suggested for the desired family size: the desire is for a family size within the family tradition and modified by the desire to have 1 of each sex, the desire reflects less on intentions but more on normative pressure to become a parent. Marrying is self selecting on the desire for a traditional family of at least 2 children. There is a rising age at marriage as well as a decline in marriages. Desired family size exceeds completed fertility. Period factors and personal circumstances affect fertility intentions. Future inquires should explore the multiple factors relating to fertility, rather than in comparing fertility desires and actual fertility. The data collected on age specific fertility were comparable to official estimates. The fertility decline was evidenced in all groups except teenagers. The decline was nearly 50% for those 20-24 years between the 1050's-80's, 33% for ages 25-29. Marriage patterns explain this decline in part. Between 1971-76, women aged 20-25 were married 37 months out of 60 months in 1971-76 versus 25 out of 60 months in 1981-86. Within the 25 year age group, marital fertility has declined and unmarried fertility, which is low, has risen, Women in a marital union of any kind has remained stable. Fertility within de facto unions, which is lower than within marriage, is higher than fertility outside a marital union, and highest in the teens. Distributions of desired children were strongly bimodel with concentrations of 2 and 4 children.

Marine sources of ice nucleating particles: results from phytoplankton cultures and samples collected at sea

NASA Astrophysics Data System (ADS)

Wilbourn, E.; Thornton, D.; Brooks, S. D.; Graff, J.

2016-12-01

The role of marine aerosols as ice nucleating particles is currently poorly understood. Despite growing interest, there are remarkably few ice nucleation measurements on representative marine samples. Here we present results of heterogeneous ice nucleation from laboratory studies and in-situ air and sea water samples collected during NAAMES (North Atlantic Aerosol and Marine Ecosystems Study). Thalassiosira weissflogii (CCMP 1051) was grown under controlled conditions in batch cultures and the ice nucleating activity depended on the growth phase of the cultures. Immersion freezing temperatures of the lab-grown diatoms were determined daily using a custom ice nucleation apparatus cooled at a set rate. Our results show that the age of the culture had a significant impact on ice nucleation temperature, with samples in stationary phase causing nucleation at -19.9 °C, approximately nine degrees warmer than the freezing temperature during exponential growth phase. Field samples gathered during the NAAMES II cruise in May 2016 were also tested for ice nucleating ability. Two types of samples were gathered. Firstly, whole cells were fractionated by size from surface seawater using a BD Biosciences Influx Cell Sorter (BD BS ISD). Secondly, aerosols were generated using the SeaSweep and subsequently size-selected using a PIXE Cascade Impactor. Samples were tested for the presence of ice nucleating particles (INP) using the technique described above. There were significant differences in the freezing temperature of the different samples; of the three sample types the lab-grown cultures tested during stationary phase froze at the warmest temperatures, followed by the SeaSweep samples (-25.6 °C) and the size-fractionated cell samples (-31.3 °C). Differences in ice nucleation ability may be due to size differences between the INP, differences in chemical composition of the sample, or some combination of these two factors. Results will be presented and atmospheric implications discussed.

AFLP markers reveal high clonal diversity and extreme longevity in four key arctic-alpine species.

PubMed

de Witte, Lucienne C; Armbruster, Georg F J; Gielly, Ludovic; Taberlet, Pierre; Stöcklin, Jürg

2012-03-01

We investigated clonal diversity, genet size structure and genet longevity in populations of four arctic-alpine plants (Carex curvula, Dryas octopetala, Salix herbacea and Vaccinium uliginosum) to evaluate their persistence under past climatic oscillations and their potential resistance to future climate change. The size and number of genets were determined by an analysis of amplified fragment length polymorphisms and a standardized sampling design in several European arctic-alpine populations, where these species are dominant in the vegetation. Genet age was estimated by dividing the size by the annual horizontal size increment from in situ growth measurements. Clonal diversity was generally high but differed among species, and the frequency distribution of genet size was strongly left-skewed. The largest C. curvula genet had an estimated minimum age of c. 4100 years and a maximum age of c. 5000 years, although 84.8% of the genets in this species were <200 years old. The oldest genets of D. octopetala, S. herbacea and V. uliginosum were found to be at least 500, 450 and 1400 years old, respectively. These results indicate that individuals in the studied populations have survived pronounced climatic oscillations, including the Little Ice Age and the postindustrial warming. The presence of genets in all size classes and the dominance of presumably young individuals suggest repeated recruitment over time, a precondition for adaptation to changing environmental conditions. Together, persistence and continuous genet turnover may ensure maximum ecosystem resilience. Thus, our results indicate that long-lived clonal plants in arctic-alpine ecosystems can persist, despite considerable climatic change. © 2011 Blackwell Publishing Ltd.

Optimized mtDNA Control Region Primer Extension Capture Analysis for Forensically Relevant Samples and Highly Compromised mtDNA of Different Age and Origin

PubMed Central

Eduardoff, Mayra; Xavier, Catarina; Strobl, Christina; Casas-Vargas, Andrea; Parson, Walther

2017-01-01

The analysis of mitochondrial DNA (mtDNA) has proven useful in forensic genetics and ancient DNA (aDNA) studies, where specimens are often highly compromised and DNA quality and quantity are low. In forensic genetics, the mtDNA control region (CR) is commonly sequenced using established Sanger-type Sequencing (STS) protocols involving fragment sizes down to approximately 150 base pairs (bp). Recent developments include Massively Parallel Sequencing (MPS) of (multiplex) PCR-generated libraries using the same amplicon sizes. Molecular genetic studies on archaeological remains that harbor more degraded aDNA have pioneered alternative approaches to target mtDNA, such as capture hybridization and primer extension capture (PEC) methods followed by MPS. These assays target smaller mtDNA fragment sizes (down to 50 bp or less), and have proven to be substantially more successful in obtaining useful mtDNA sequences from these samples compared to electrophoretic methods. Here, we present the modification and optimization of a PEC method, earlier developed for sequencing the Neanderthal mitochondrial genome, with forensic applications in mind. Our approach was designed for a more sensitive enrichment of the mtDNA CR in a single tube assay and short laboratory turnaround times, thus complying with forensic practices. We characterized the method using sheared, high quantity mtDNA (six samples), and tested challenging forensic samples (n = 2) as well as compromised solid tissue samples (n = 15) up to 8 kyrs of age. The PEC MPS method produced reliable and plausible mtDNA haplotypes that were useful in the forensic context. It yielded plausible data in samples that did not provide results with STS and other MPS techniques. We addressed the issue of contamination by including four generations of negative controls, and discuss the results in the forensic context. We finally offer perspectives for future research to enable the validation and accreditation of the PEC MPS method for final implementation in forensic genetic laboratories. PMID:28934125

K/Ar dating of lunar soils. II

NASA Technical Reports Server (NTRS)

Alexander, E. C., Jr.; Bates, A.; Coscio, M. R., Jr.; Dragon, J. C.; Murthy, V. R.; Pepin, R. O.; Venkatesan, T. R.

1976-01-01

An attempt is made to identify those K/Ar techniques which extract the most reliable chronological information from lunar soils and to define the situations in which the best data are obtainable. Results are presented for determinations of the exposure and K/Ar ages of five lunar soil samples, which were performed by applying correlation techniques for a two-component argon structure to stepwise-heated and neutron-irradiated aliquots of grain-sized separates. It is found that ages deduced from Ar-40/surface-correlated Ar-36 vs K-40/surface-correlated Ar-36 and analogous plots of data from grain-sized separates appear to be the best available K/Ar ages of submature to mature lunar soils, that ages deduced from Ar-40 vs Ar-36 and analogous plots which assume a uniform K content can be significantly in error, and that stepwise-heating (Ar-40)-(Ar-39) experiments yield useful information only for simple immature soils where the K-Ar systematics are dominated by a single component.

Anisotropic growth and formation mechanism investigation of 1D ZnO nanorods in spin-coating sol-gel process.

PubMed

Song, Yijian; Zheng, Maojun; Ma, Li; Shen, Wenzhong

2010-01-01

ZnO nanorods are fabricated on glass substrate by spin-coating sol-gel process using non-basic aged solution and annealing. Sample solutions reserved in room temperature for different time (one day, one month, two months and four months) are prepared for the experiment. The morphology study indicates that the aging time has direct influence on the final products. This is verified by the Transmission Electron Microscopy and Photon Correlation Spectroscopy study. Small crystalline nanoparticles would gradually nucleate and aggregate in the sol during the aging process. They act as nucleation site for the secondary crystal growth into nanorods during anneal. Both the size of crystalline particles in the sol and the size of nanorods will grow bigger as the aging time increases. The products' structure and optical property are further studied by X-ray diffraction spectroscopy, Photoluminescence and Raman spectroscopy. This work also helps to further clarify the formation mechanism of ZnO nanorods by solution-based method.

Titanium dioxide nanoparticles: Impact of increasing ionic strength during synthesis, reflux, and hydrothermal aging

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

Isley, Sara L.; Jordan, David S.; Penn, R. Lee

2009-01-08

This work investigates the role of ionic strength during synthesis, reflux, and hydrothermal aging of sol-gel synthesized titanium dioxide. Research presented here uses X-ray diffraction data and Rietveld refinements to quantify anatase, brookite, and rutile phases as functions of synthetic and aging variables. In addition, the Scherrer equation is used to obtain average crystallite sizes for each phase quantified. Results presented in this work demonstrate that the most control over the sol-gel products can be obtained by modifying the pH during hydrolysis. In addition, while varying the ionic strength during reflux and hydrothermal aging can result in enhanced control overmore » the crystalline phase and crystallite size, the most control can be achieved by varying the ionic strength during synthesis. Finally, sol-gel synthesis at low pH (-0.6) and high-chloride concentration (3 M NaCl) produced a heterogeneous sample composed of nanocrystalline anatase (3.8 nm) and rutile (2.9 nm)« less

Proteoglycan depletion and size reduction in lesions of early grade chondromalacia of the patella.

PubMed

Väätäinen, U; Häkkinen, T; Kiviranta, I; Jaroma, H; Inkinen, R; Tammi, M

1995-10-01

To determine the content and molecular size of proteoglycans (PGs) in patellar chondromalacia (CM) and control cartilages as a first step in investigating the role of matrix alterations in the pathogenesis of this disease. Chondromalacia tissue from 10 patients was removed with a surgical knife. Using identical techniques, apparently healthy cartilage of the same site was obtained from 10 age matched cadavers (mean age 31 years in both groups). Additional pathological cartilage was collected from 67 patients with grades II-IV CM (classified according to Outerbridge) using a motorised shaver under arthroscopic control. The shaved cartilage chips were collected with a dense net from the irrigation fluid of the shaver. The content of tissue PGs was determined by Safranin O precipitation or uronic acid content, and the molecular size by mobility on agarose gel electrophoresis. The mean PG content of the CM tissue samples with a knife was dramatically reduced, being only 15% of that in controls. The cartilage chips collected from shaving operations of grades II, III, and IV CM showed a decreasing PG content: 9%, 5%, and 1% of controls, respectively. Electrophoretic analysis of PGs extracted with guanidium chloride from the shaved tissue samples suggested a significantly reduced size of aggrecans in the mild (grade II) lesions. These data show that there is already a dramatic and progressive depletion of PGs in CM grade II lesions. This explains the softening of cartilage, a typical finding in the arthroscopic examination of CM. The PG size reduction observed in grade II implicates proteolytic attack as a factor in the pathogenesis of CM.

Shape, size, and maturity trajectories of the human ilium.

PubMed

Wilson, Laura A B; Ives, Rachel; Cardoso, Hugo F V; Humphrey, Louise T

2015-01-01

Morphological traits of the ilium have consistently been more successful for juvenile sex determination than have techniques applied to other skeletal elements, however relatively little is known about the ontogeny and maturation of size and shape dimorphism in the ilium. We use a geometric morphometric approach to quantitatively separate the ontogeny of size and shape of the ilium, and analyze interpopulation differences in the onset, rate and patterning of sexual dimorphism. We captured the shape of three traits for a total of 191 ilia from Lisbon (Portugal) and London (UK) samples of known age and sex (0-17 years). Our results indicate that a) there is a clear dissociation between the ontogeny of size and shape in males and females, b) the ontogeny of size and shape are each defined by non-linear trajectories that differ between the sexes, c) there are interpopulation differences in ontogenetic shape trajectories, which point to population-specific patterning in the attainment of sexual dimorphism, and d) the rate of shape maturation and size maturation is typically higher for females than males. Male and female shape differences in the ilium are brought about by trajectory divergence. Differences in size and shape maturation between the sexes suggest that maturity may confound our ability to discriminate between the sexes by introducing variation not accounted for in age-based groupings. The accuracy of sex determination methods using the ilium may be improved by the use of different traits for particular age groups, to capture the ontogenetic development of shape in both sexes. © 2014 Wiley Periodicals, Inc.

Age & reproduction in three reef - dwelling serranid fishes of the northeastern Gulf of Mexico outer continental shelf: Pronotogrammus martinicensis, Hemanthias vivanus & Serranus phoebe (with preliminary observations on the Pomacentrid fish, Chromis enchrysurus)

USGS Publications Warehouse

Thurman, Paul E.; McBride, Richard S.; Sulak, Kenneth J.; Dennis, George D.

2004-01-01

Specimens of the four study species were collected during cruises to outer-continental shelf reefs of the northeastern Gulf of Mexico. Age was estimated for all serranid species using whole otoliths and C. enchrysurus ages were determined from transverse sections of sagittal otoliths. Ring structure observed on otoliths was validated as having an annual periodicity for P. martinicensis using marginal increment analysis. Ring structure on remaining species was assumed to correspond to age (years). Pronotogrammus martinicensis, H. vivanus, S. phoebe, and C. enchrysurus exhibited maximum ages of 9, 8, 5, and 11, respectively. Spatial variations in size-at-age were observed in P. martinicensis populations. Individuals inhabiting reefs in the Madison-Swanson Reserve area on the West Florida Shelf edge exhibited the fastest growth rates, while the slowest growing P. martinicensis were collected from the Alabama Alps Reef, the farthest west study reef. Pronotogrammus martinicensis and H. vivanus are both protogynous hermaphrodites. Evidence of active spawning was observed in the months from February through July for P. martinicensis, and March and May for H. vivanus. Serranus phoebe was observed to be a simultaneous hermaphroditic capable of spawning year-round. Batch fecundity estimates for P. martinicensis ranged from 149-394 oocytes per fish. Size selectivity was evident in our primary sampling method, hook and line using small tandem bait hooks. Smaller size-classes of all species examined were under-represented in our samples, hindering accurate growth modeling. Due to the protogynous nature of P. martinicensis and H. vivanus, hook and line sampling also tended to select for males. Future descriptions of the reproductive biology of both protogynous species would be more complete if less selective sampling methods could be successfully employed. The data presented here contribute to a better assessment of the fish community of the northeastern Gulf of Mexico. Little information on age and reproduction was previously available for the serranid and pomacentrid species investigated in the present study. These species are important links between both planktonic or benthic food resources and economically-valuable groupers, snappers, and amberjacks. If a catastrophic natural or anthropogenic event occurred in these outer continental shelf reef habitats, the resultant loss of these forage species would immediately impact regional fish production via the food chain. This would be particularly true for reef-resident commercial and recreational fish species that depend extensively upon a diet of small forage fish species. Recovery to a stable community, fully repopulated with small forage fish species, would require at least a decade, possibly longer if the habitat had been substantially degraded during the initial disturbance.

Satisfaction with social networks: an examination of socioemotional selectivity theory across cohorts.

PubMed

Lansford, J E; Sherman, A M; Antonucci, T C

1998-12-01

This study examines L. L. Carstensen's (1993, 1995) socioemotional selectivity theory within and across three cohorts spanning 4 decades. Socioemotional selectivity theory predicts that as individuals age, they narrow their social networks to devote more emotional resources to fewer relationships with close friends and family. Data from 3 cohorts of nationally representative samples were analyzed to determine whether respondents' satisfaction with the size of their social networks differed by age, cohort, or both. Results support socioemotional selectivity theory: More older adults than younger adults were satisfied with the current size of their social networks rather than wanting larger networks. These findings are consistent across all cohorts. Results are discussed with respect to social relationships across the life course.

Microcrater investigations on lunar rock 12002

NASA Technical Reports Server (NTRS)

Hartung, J. B.; Hodges, F.; Horz, F.; Storzer, D.

1975-01-01

Relative ages of 26 submillimeter-sized pits from an equilibrium population in rock 12002 were measured by determining the densities of pits 0.7 microns in diameter and larger on the submillimeter-sized pits. Production rates for 0.7 micron diameter pits were determined from solar-flare track exposure age measurements, and the data for rock 12002 are consistent with previously obtained data for sample 15205 if a lower meteoroid flux prevailed in the past. Metal mounds or spherules within a microcrater pit glass were found to have a meteoritic composition, and an impact lining consisting of protruding crystals was observed. The crystals apparently developed during exposure to space immediately after the 200-micron diameter pit was formed by impact into an olivine grain.

Combined Bisulfite Restriction Analysis for brain tissue identification.

PubMed

Samsuwan, Jarunya; Muangsub, Tachapol; Yanatatsaneejit, Pattamawadee; Mutirangura, Apiwat; Kitkumthorn, Nakarin

2018-05-01

According to the tissue-specific methylation database (doi: 10.1016/j.gene.2014.09.060), methylation at CpG locus cg03096975 in EML2 has been preliminarily proven to be specific to brain tissue. In this study, we enlarged sample size and developed a technique for identifying brain tissue in aged samples. Combined Bisulfite Restriction Analysis-for EML2 (COBRA-EML2) technique was established and validated in various organ samples obtained from 108 autopsies. In addition, this technique was also tested for its reliability, minimal DNA concentration detected, and use in aged samples and in samples obtained from specific brain compartments and spinal cord. COBRA-EML2 displayed 100% sensitivity and specificity for distinguishing brain tissue from other tissues, showed high reliability, was capable of detecting minimal DNA concentration (0.015ng/μl), could be used for identifying brain tissue in aged samples. In summary, COBRA-EML2 is a technique to identify brain tissue. This analysis is useful in criminal cases since it can identify the vital organ tissues from small samples acquired from criminal scenes. The results from this analysis can be counted as a medical and forensic marker supporting criminal investigations, and as one of the evidences in court rulings. Copyright © 2018 Elsevier B.V. All rights reserved.

Behavioral Phenotype in Adults with Prader-Willi Syndrome

ERIC Educational Resources Information Center

Sinnema, Margje; Einfeld, Stewart L.; Schrander-Stumpel, Constance T. R. M.; Maaskant, Marian A.; Boer, Harm; Curfs, Leopold M. G.

2011-01-01

Prader-Willi syndrome (PWS) is characterized by temper tantrums, impulsivity, mood fluctuations, difficulty with change in routine, skinpicking, stubbornness and aggression. Many studies on behavior in PWS are limited by sample size, age range, a lack of genetically confirmed diagnosis of PWS and inconsistent assessment of behavior. The aim of…

Early-type galaxies: mass-size relation at z ˜ 1.3 for different environments

NASA Astrophysics Data System (ADS)

Raichoor, A.; Mei, S.; Stanford, S. A.; Holden, B. P.; Nakata, F.; Rosati, P.; Shankar, F.; Tanaka, M.; Ford, H.; Huertas-Company, M.; Illingworth, G.; Kodama, T.; Postman, M.; Rettura, A.; Blakeslee, J. P.; Demarco, R.; Jee, M. J.; White, R. L.

2011-12-01

We combine multi-wavelength data of the Lynx superstructure and GOODS/CDF-S to build a sample of 75 visually selected early-type galaxies (ETGs), spanning different environments (cluster/group/field) at z ˜ 1.3. By estimating their mass, age (SED fitting, with a careful attention to the stellar population model used) and size, we are able to probe the dependence on the environment of the mass-size relation. We find that, for ETGs with 10^{10} < M / M_⊙ < 10^{11.5}, (1) the mass-size relation in the field did not evolve overall from z ˜ 1.3 to present; (2) the mass-size relation in cluster/group environments at z ˜ 1.3 lies at smaller sizes than the local mass-size relation (R_{e,z ˜ 1.3}/R_{e,z = 0} ˜ 0.6-0.8).

Prevalence of Overweight and Obesity among Female Adolescents in Jordan: A comparison between Two International Reference Standards

PubMed Central

O. Musaiger, Abdulrahman; Al-Mannai, Mariam; Tayyem, Reema

2013-01-01

Objective: To find out the prevalence of overweight and obesity among female adolescents in Jordan. Methodology: A cross-sectional survey on females aged 15–18 in Amman, Jordan, was carried out using a multistage stratified random sampling method. The total sample size was 475 girls. Weight and height were measured and body mass index for age was used to determine overweight and obesity using the IOTF and WHO international standards. Results: The prevalence of overweight and obesity decreased with age. The highest prevalence of overweight and obesity was reported at age 15 (24.4% and 8.9%, respectively). The WHO standard showed a higher prevalence of obesity than the IOTF standard in all age groups. Conclusions: Overweight and obesity are serious public health problems among adolescents in Jordan, using both international standards. A program to combat obesity among schoolchildren, therefore, should be given a high priority in school health policy in Jordan. PMID:24353605

Are we using the appropriate reference samples to develop juvenile age estimation methods based on bone size? An exploration of growth differences between average children and those who become victims of homicide.

PubMed

Spake, Laure; Cardoso, Hugo F V

2018-01-01

The population on which forensic juvenile skeletal age estimation methods are applied has not been critically considered. Previous research suggests that child victims of homicide tend to be from socioeconomically disadvantaged contexts, and that these contexts impair linear growth. This study investigates whether juvenile skeletal remains examined by forensic anthropologists are short for age compared to their normal healthy peers. Cadaver lengths were obtained from records of autopsies of 1256 individuals, aged birth to eighteen years at death, conducted between 2000 and 2015 in Australia, New Zealand, and the U.S. Growth status of the forensic population, represented by homicide victims, and general population, represented by accident victims, were compared using height for age Z-scores and independent sample t-tests. Cadaver lengths of the accident victims were compared to growth references using one sample t-tests to evaluate whether accident victims reflect the general population. Homicide victims are shorter for age than accident victims in samples from the U.S., but not in Australia and New Zealand. Accident victims are more representative of the general population in Australia and New Zealand. Different results in Australia and New Zealand as opposed to the U.S. may be linked to socioeconomic inequality. These results suggest that physical anthropologists should critically select reference samples when devising forensic juvenile skeletal age estimation methods. Children examined in forensic investigations may be short for age, and thus methods developed on normal healthy children may yield inaccurate results. A healthy reference population may not necessarily constitute an appropriate growth comparison for the forensic anthropology population. Copyright © 2017 Elsevier B.V. All rights reserved.

Prediction of Precipitation Strengthening in the Commercial Mg Alloy AZ91 Using Dislocation Dynamics

DOE PAGES

Aagesen, L. K.; Miao, J.; Allison, J. E.; ...

2018-03-05

In this paper, dislocation dynamics simulations were used to predict the strengthening of a commercial magnesium alloy, AZ91, due to β-Mg 17Al 12 formed in the continuous precipitation mode. The precipitate distributions used in simulations were determined based on experimental characterization of the sizes, shapes, and number densities of the precipitates for 10-hour aging and 50-hour aging. For dislocations gliding on the basal plane, which is expected to be the dominant contributor to plastic deformation at room temperature, the critical resolved shear stress to bypass the precipitate distribution was 3.5 MPa for the 10-hour aged sample and 16.0 MPa formore » the 50-hour aged sample. The simulation results were compared to an analytical model of strengthening in this alloy, and the analytical model was found to predict critical resolved shear stresses that were approximately 30 pct lower. A model for the total yield strength was developed and compared with experiment for the 50-hour aged sample. Finally, the predicted yield strength, which included the precipitate strengthening contribution from the DD simulations, was 132.0 MPa, in good agreement with the measured yield strength of 141 MPa.« less

Indian parents prefer vaccinating their daughters against HPV at older ages.

PubMed

Madhivanan, Purnima; Srinivas, Vijaya; Marlow, Laura; Mukherjee, Soumyadeep; Narayanappa, Doddaiah; Mysore, Shekar; Arun, Anjali; Krupp, Karl

2014-01-01

Increasing uptake of human papillomavirus (HPV) vaccine should be a priority in developing countries since they suffer 88% of the world's cervical cancer burden. In many countries studies show that age at vaccination is an important determinate of parental acceptability. This study explores parental preferences on age-to-vaccinate for adolescent school-going girls. The sample was selected using a two-stage probability proportional to size cluster sampling methodology. Questionnaires were sent home with a random sample of 800 adolescent girls attending 12 schools in Mysore to be completed by parents. Descriptive statistics including frequencies, percentages and proportions were generated for independent variables and bivariate analyses (Chi square test) were used to assess the relationship between independent and appropriate age-to-vaccinate. HPV vaccination acceptability was high at 71%. While 5.3% of parents felt girls should be vaccinated by 10 years or younger; 38.3% said 11-15 years; 14.8% said 16-18 years; 5.8% suggested over 19 years; and 33% didn't know. Only 2.8% of parents would not vaccinate their daughters. Delaying HPV vaccination until later ages may significantly increase uptake of the HPV vaccine in India.

Prediction of Precipitation Strengthening in the Commercial Mg Alloy AZ91 Using Dislocation Dynamics

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

Aagesen, L. K.; Miao, J.; Allison, J. E.

In this paper, dislocation dynamics simulations were used to predict the strengthening of a commercial magnesium alloy, AZ91, due to β-Mg 17Al 12 formed in the continuous precipitation mode. The precipitate distributions used in simulations were determined based on experimental characterization of the sizes, shapes, and number densities of the precipitates for 10-hour aging and 50-hour aging. For dislocations gliding on the basal plane, which is expected to be the dominant contributor to plastic deformation at room temperature, the critical resolved shear stress to bypass the precipitate distribution was 3.5 MPa for the 10-hour aged sample and 16.0 MPa formore » the 50-hour aged sample. The simulation results were compared to an analytical model of strengthening in this alloy, and the analytical model was found to predict critical resolved shear stresses that were approximately 30 pct lower. A model for the total yield strength was developed and compared with experiment for the 50-hour aged sample. Finally, the predicted yield strength, which included the precipitate strengthening contribution from the DD simulations, was 132.0 MPa, in good agreement with the measured yield strength of 141 MPa.« less

Prediction of Precipitation Strengthening in the Commercial Mg Alloy AZ91 Using Dislocation Dynamics

NASA Astrophysics Data System (ADS)

Aagesen, L. K.; Miao, J.; Allison, J. E.; Aubry, S.; Arsenlis, A.

2018-03-01

Dislocation dynamics simulations were used to predict the strengthening of a commercial magnesium alloy, AZ91, due to β-Mg17Al12 formed in the continuous precipitation mode. The precipitate distributions used in simulations were determined based on experimental characterization of the sizes, shapes, and number densities of the precipitates for 10-hour aging and 50-hour aging. For dislocations gliding on the basal plane, which is expected to be the dominant contributor to plastic deformation at room temperature, the critical resolved shear stress to bypass the precipitate distribution was 3.5 MPa for the 10-hour aged sample and 16.0 MPa for the 50-hour aged sample. The simulation results were compared to an analytical model of strengthening in this alloy, and the analytical model was found to predict critical resolved shear stresses that were approximately 30 pct lower. A model for the total yield strength was developed and compared with experiment for the 50-hour aged sample. The predicted yield strength, which included the precipitate strengthening contribution from the DD simulations, was 132.0 MPa, in good agreement with the measured yield strength of 141 MPa.

The effects of cold rolling and the subsequent heat treatments on the shape memory and the superelasticity characteristics of Cu73Al16Mn11 shape memory alloy

NASA Astrophysics Data System (ADS)

Babacan, N.; Ma, J.; Turkbas, O. S.; Karaman, I.; Kockar, B.

2018-01-01

In the present study, the effect of thermo-mechanical treatments on the shape memory and the superelastic characteristics of Cu73Al16Mn11 (at%) shape memory alloy were investigated. 10%, 50% and 70% cold rolling and subsequent heat treatment processes were conducted to achieve strengthening via grain size refinement. 70% grain size reduction compared to the homogenized condition was obtained using 70% cold rolling and subsequent recrystallization heat treatment technique. Moreover, 10% cold rolling was applied to homogenized specimen to reveal the influence of the low percentage cold rolling reduction with no heat treatment on shape memory properties of Cu73Al16Mn11 (at%) alloy. Stress free transformation temperatures, monotonic tension and superelasticity behaviors of these samples were compared with those of the as-aged sample. Isobaric heating-cooling experiments were also conducted to see the dimensional stability of the samples as a function of applied stress. The 70% grain-refined sample exhibited better dimensional stability showing reduced residual strain levels upon thermal cycling under constant stress compared with the as-aged material. However, no improvement was achieved with grain size reduction in the superelasticity experiments. This distinctive observation was attributed to the difference in the magnitude of the stress levels achieved during two different types of experiments which were the isobaric heating-cooling and superelasticity tests. Intergranular fracture due to the stress concentration overcame the strengthening effect via grain refinement in the superelasticity tests at higher stress values. On the other hand, the strength of the material and resistance of material against plastic deformation upon phase transformation were increased as a result of the grain refinement at lower stress values in the isobaric heating-cooling experiments.

Self-objectification and disordered eating: A meta-analysis.

PubMed

Schaefer, Lauren M; Thompson, J Kevin

2018-06-01

Objectification theory posits that self-objectification increases risk for disordered eating. The current study sought to examine the relationship between self-objectification and disordered eating using meta-analytic techniques. Data from 53 cross-sectional studies (73 effect sizes) revealed a significant moderate positive overall effect (r = .39), which was moderated by gender, ethnicity, sexual orientation, and measurement of self-objectification. Specifically, larger effect sizes were associated with female samples and the Objectified Body Consciousness Scale. Effect sizes were smaller among heterosexual men and African American samples. Age, body mass index, country of origin, measurement of disordered eating, sample type and publication type were not significant moderators. Overall, results from the first meta-analysis to examine the relationship between self-objectification and disordered eating provide support for one of the major tenets of objectification theory and suggest that self-objectification may be a meaningful target in eating disorder interventions, though further work is needed to establish temporal and causal relationships. Findings highlight current gaps in the literature (e.g., limited representation of males, and ethnic and sexual minorities) with implications for guiding future research. © 2018 Wiley Periodicals, Inc.

Effect sizes and cut-off points: a meta-analytical review of burnout in latin American countries.

PubMed

García-Arroyo, Jose; Osca Segovia, Amparo

2018-05-02

Burnout is a highly prevalent globalized health issue that causes significant physical and psychological health problems. In Latin America research on this topic has increased in recent years, however there are no studies comparing results across countries, nor normative reference cut-offs. The present meta-analysis examines the intensity of burnout (emotional exhaustion, cynicism and personal accomplishment) in 58 adult nonclinical samples from 8 countries (Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Peru and Venezuela). We found low intensity of burnout but there are significant differences between countries in emotional exhaustion explained by occupation and language. Social and human service professionals (police officers, social workers, public administration staff) are more exhausted than health professionals (physicians, nurses) or teachers. The samples with Portuguese language score higher in emotional exhaustion than Spanish, supporting the theory of cultural relativism. Demographics (sex, age) and study variables (sample size, instrument), were not found significant to predict burnout. The effect size and confidence intervals found are proposed as a useful baseline for research and medical diagnosis of burnout in Latin American countries.

Mercury in fishes from Wrangell-St. Elias National Park and Preserve, Alaska

USGS Publications Warehouse

Kowalski, Brandon M.; Willacker, James J.; Zimmerman, Christian E.; Eagles-Smith, Collin A.

2014-01-01

In this study, mercury (Hg) concentrations were examined in fishes from Wrangell-St. Elias National Park and Preserve, Alaska, the largest and one of the most remote units in the national park system. The goals of the study were to (1) examine the distribution of Hg in select lakes of Wrangell-St. Elias National Park and Preserve; (2) evaluate the differences in Hg concentrations among fish species and with fish age and size; and (3) assess the potential ecological risks of Hg to park fishes, wildlife, and human consumers by comparing Hg concentrations to a series of risk benchmarks. Total Hg concentrations ranged from 17.9 to 616.4 nanograms per gram wet weight (ng/g ww), with a mean (± standard error) of 180.0 ±17.9 across the 83 individuals sampled. Without accounting for the effects of size, Hg concentrations varied by a factor of 10.9 across sites and species. After accounting for the effects of size, Hg concentrations were even more variable, differing by a factor of as much as 13.2 within a single species sampled from two lakes. Such inter-site variation suggests that site characteristics play an important role in determining fish Hg concentrations and that more intensive sampling may be necessary to adequately characterize Hg contamination in the park. Size-normalized Hg concentrations also differed among three species sampled from Tanada Lake, and Hg concentrations were strongly correlated with age. Furthermore, potential risks to park fish, wildlife, and human users were variable across lakes and species. Although no fish from two of the lakes studied (Grizzly Lake and Summit Lake) had Hg concentrations exceeding any of the benchmarks used, concentrations in Copper Lake and Tanada Lake exceeded conservative benchmarks for bird (90 ng/g ww in whole-body) and human (150 ng/g ww in muscle) consumption. In Tanada Lake, concentrations in most fishes also exceeded benchmarks for risk to moderate- and low-sensitivity avian consumers (180 and 270 ng/g ww in whole-body, respectively), as well as the concentration at which Alaska State guidelines suggest at-risk groups limit fish consumption to 3 meals per week (320 ng/g). However, the relationship between Hg concentrations and fish size in Tanada Lake suggests that consumption of smaller-sized fishes could reduce Hg exposure in human consumers.

Development of a Simple Positron Age-Momentum Setup

NASA Astrophysics Data System (ADS)

Sheffield, Thomas; Quarles, C. A.

2009-04-01

A positron age-momentum setup that uses NIM Bin electronic modules and a conventional multichannel analyzer (MCA) is described. The essential idea is to accumulate a Doppler broadened spectrum (sensitive to the annihilation electron momentum) using a high purity Germanium detector in coincidence with a BaF2 scintillation counter, which also serves as the stop signal in a conventional positron lifetime setup. The MCA that collects the Doppler spectrum is gated by a selected region of the lifetime spectrum. Thus we can obtain Doppler broadening spectra as a function of positron lifetime: an age-momentum spectrum. The apparatus has been used so far to investigate a ZnO sample where the size of different vacancy trapping sites may affect the positron lifetime and the Doppler broadening spectrum. We are also looking at polymer and rubber carbon-black composite samples where differences in the Doppler spectrum may arise from positron trapping or positronium formation in the samples. Correction for background and contribution from the positron source itself to the Doppler spectrum will be discussed.

A repeatable geometric morphometric approach to the analysis of hand entheseal three-dimensional form.

PubMed

Karakostis, Fotios Alexandros; Hotz, Gerhard; Scherf, Heike; Wahl, Joachim; Harvati, Katerina

2018-05-01

The purpose of this study was to put forth a precise landmark-based technique for reconstructing the three-dimensional shape of human entheseal surfaces, to investigate whether the shape of human entheses is related to their size. The effects of age-at-death and bone length on entheseal shapes were also assessed. The sample comprised high-definition three-dimensional models of three right hand entheseal surfaces, which correspond to 45 male adult individuals of known age. For each enthesis, a particular landmark configuration was introduced, whose precision was tested both within and between observers. The effect of three-dimensional size, age-at-death, and bone length on shape was investigated through shape regression. The method presented high intra-observer and inter-observer repeatability. All entheses showed significant allometry, with the area of opponens pollicis demonstrating the most substantial relationship. This was particularly due to variation related to its proximal elongated ridge. The effect of age-at-death and bone length on entheses was limited. The introduced methodology can set a reliable basis for further research on the factors affecting entheseal shape. Using both size and shape, variables can provide further information on entheseal variation and its biomechanical implications. The low entheseal variation by age verifies that specimens under 50 years of age are not substantially affected by age-related changes. The lack of correlation between entheseal shape and bone length or age implies that other factors may regulate entheseal surfaces. Future research should focus on multivariate shape patterns among entheses and their association with occupation. © 2018 Wiley Periodicals, Inc.

Development of food photographs for use with children aged 18 months to 16 years: Comparison against weighed food diaries – The Young Person’s Food Atlas (UK)

PubMed Central

Hawkins, Adrian; Barton, Karen L.; Stamp, Elaine; Matthews, John N. S.; Adamson, Ashley J.

2017-01-01

Traditional dietary assessment methods, used in the UK, such as weighed food diaries impose a large participant burden, often resulting in difficulty recruiting representative samples and underreporting of energy intakes. One approach to reducing the burden placed on the participant is to use portion size assessment tools to obtain an estimate of the amount of food consumed, removing the need to weigh all foods. An age range specific food atlas was developed for use in assessing children’s dietary intakes. The foods selected and portion sizes depicted were derived from intakes recorded during the UK National Diet and Nutrition Surveys of children aged 1.5 to 16 years. Estimates of food portion sizes using the food atlas were compared against 4-day weighed intakes along with in-school / nursery observations, by the research team. Interviews were conducted with parents the day after completion of the diary, and for children aged 4 to 16 years, also with the child. Mean estimates of portion size consumed were within 7% of the weight of food recorded in the weighed food diary. The limits of agreement were wide indicating high variability of estimates at the individual level but the precision increased with increasing age. For children 11 years and over, agreement with weighed food diaries, was as good as that of their parents in terms of total weight of food consumed and of intake of energy and key nutrients. The age appropriate food photographs offer an alternative to weighed intakes for dietary assessment with children. PMID:28199319

Pressuring and restrictive feeding styles influence infant feeding and size among a low-income African-American sample.

PubMed

Thompson, Amanda L; Adair, Linda S; Bentley, Margaret E

2013-03-01

The prevalence of overweight among infants and toddlers has increased dramatically in the past three decades, highlighting the importance of identifying factors contributing to early excess weight gain, particularly in high-risk groups. Parental feeding styles and the attitudes and behaviors that characterize parental approaches to maintaining or modifying children's eating behavior are an important behavioral component shaping early obesity risk. Using longitudinal data from the Infant Care and Risk of Obesity Study, a cohort study of 217 African-American mother-infant pairs with feeding styles, dietary recalls, and anthropometry collected from 3 to 18 months of infant age, we examined the relationship between feeding styles, infant diet, and weight-for-age and sum of skinfolds. Longitudinal mixed models indicated that higher pressuring and indulgent feeding style scores were positively associated with greater infant energy intake, reduced odds of breastfeeding, and higher levels of age-inappropriate feeding of liquids and solids, whereas restrictive feeding styles were associated with lower energy intake, higher odds of breastfeeding, and reduced odds of inappropriate feeding. Pressuring and restriction were also oppositely related to infant size with pressuring associated with lower infant weight-for-age and restriction with higher weight-for-age and sum of skinfolds. Infant size also predicted maternal feeding styles in subsequent visits indicating that the relationship between size and feeding styles is likely bidirectional. Our results suggest that the degree to which parents are pressuring or restrictive during feeding shapes the early feeding environment and, consequently, may be an important environmental factor in the development of obesity. Copyright © 2012 The Obesity Society.

Pressuring and restrictive feeding styles influence infant feeding and size among a low-income African-American sample

PubMed Central

Thompson, Amanda L; Adair, Linda S; Bentley, Margaret E

2012-01-01

The prevalence of overweight among infants and toddlers has increased dramatically in the past three decades, highlighting the importance of identifying factors contributing to early excess weight gain, particularly in high-risk groups. Parental feeding styles, the attitudes and behaviors that characterize parental approaches to maintaining or modifying children’s eating behavior, are an important behavioral component shaping early obesity risk. Using longitudinal data from the Infant Care and Risk of Obesity Study, a cohort study of 217 African-American mother-infant pairs with feeding styles, dietary recalls and anthropometry collected from 3-18 months of infant age, we examined the relationship between feeding styles, infant diet and weight–for-age and sum of skinfolds. Longitudinal mixed models indicated that higher pressuring and indulgent feeding style scores were positively associated with greater infant energy intake, reduced odds of breastfeeding and higher levels of age-inappropriate feeding of liquids and solids while restrictive feeding styles were associated with lower energy intake, higher odds of breastfeeding and reduced odds of inappropriate feeding. Pressuring and restriction were also oppositely related to infant size with pressuring associated with lower infant weight-for-age and restriction with higher weight-for-age and sum of skinfolds. Infant size also predicted maternal feeding styles in subsequent visits indicating that the relationship between size and feeding styles is likely bidirectional. Our results suggest that the degree to which parents are pressuring or restrictive during feeding shapes the early feeding environment and, consequently, may be an important environmental factor in the development of obesity. PMID:23592664

A prospective study of autistic-like traits in unaffected siblings of probands with autism spectrum disorder.

PubMed

Georgiades, Stelios; Szatmari, Peter; Zwaigenbaum, Lonnie; Bryson, Susan; Brian, Jessica; Roberts, Wendy; Smith, Isabel; Vaillancourt, Tracy; Roncadin, Caroline; Garon, Nancy

2013-01-01

The presence of autistic-like traits in relatives of individuals with autism spectrum disorder (ASD) is well recognized, but, to our knowledge, the emergence of these traits early in development has not been studied. To prospectively investigate the emergence of autistic-like traits in unaffected (no ASD diagnosis) infant siblings of probands diagnosed as having ASD. Two groups of children unaffected with ASD were assessed prospectively-siblings of probands diagnosed as having ASD (high risk [HR]) and control subjects with no family history of ASD (low risk [LR]). Scores on a measure of autistic-like traits at 12 months of age were used in a cluster analysis of the entire sample. A prospective study of infant siblings of probands with ASD from 3 diagnostic centers in Canada. The study included 170 HR and 90 LR children, none of whom was diagnosed as having ASD at age 3 years. The Autism Observation Scale for Infants was used to measure autistic-like traits and derive clusters at 12 months of age. Clusters were compared on ASD symptoms, cognitive abilities, and social-emotional difficulties at age 3 years. Two clusters were identified. Cluster 1 (n = 37; 14.2% of total sample) had significantly higher levels of autistic-like traits compared with cluster 2. Within cluster 1, 33 children came from the siblings (19.4% of HR group) and only 4 came from the control subjects (4.5% of LR group). At age 3 years, children from cluster 1 had more social-communication impairment (effect size > 0.70; P < .001), lower cognitive abilities (effect size = -0.59; P < .005), and more internalizing problems (effect size = 0.55; P = .01). Compared with control subjects, HR siblings had a relative risk of 4.3 (95% CI,1.6-11.9) for membership in cluster 1. Study findings suggest the emergence of autistic-like traits resembling a broader autism phenotype by 12 months of age in approximately 19% of HR siblings who did not meet ASD diagnostic criteria at age 3 years.

Photochemical aging of aerosol particles in different air masses arriving at Baengnyeong Island, Korea

NASA Astrophysics Data System (ADS)

Kang, Eunha; Lee, Meehye; Brune, William H.; Lee, Taehyoung; Park, Taehyun; Ahn, Joonyoung; Shang, Xiaona

2018-05-01

Atmospheric aerosol particles are a serious health risk, especially in regions like East Asia. We investigated the photochemical aging of ambient aerosols using a potential aerosol mass (PAM) reactor at Baengnyeong Island in the Yellow Sea during 4-12 August 2011. The size distributions and chemical compositions of aerosol particles were measured alternately every 6 min from the ambient air or through the highly oxidizing environment of a potential aerosol mass (PAM) reactor. Particle size and chemical composition were measured by using the combination of a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Inside the PAM reactor, O3 and OH levels were equivalent to 4.6 days of integrated OH exposure at typical atmospheric conditions. Two types of air masses were distinguished on the basis of the chemical composition and the degree of aging: air transported from China, which was more aged with a higher sulfate concentration and O : C ratio, and the air transported across the Korean Peninsula, which was less aged with more organics than sulfate and a lower O : C ratio. For both episodes, the particulate sulfate mass concentration increased in the 200-400 nm size range when sampled through the PAM reactor. A decrease in organics was responsible for the loss of mass concentration in 100-200 nm particles when sampled through the PAM reactor for the organics-dominated episode. This loss was especially evident for the m/z 43 component, which represents less oxidized organics. The m/z 44 component, which represents further oxidized organics, increased with a shift toward larger sizes for both episodes. It is not possible to quantify the maximum possible organic mass concentration for either episode because only one OH exposure of 4.6 days was used, but it is clear that SO2 was a primary precursor of secondary aerosol in northeast Asia, especially during long-range transport from China. In addition, inorganic nitrate evaporated in the PAM reactor as sulfate was added to the particles. These results suggest that the chemical composition of aerosols and their degree of photochemical aging, particularly for organics, are also crucial in determining aerosol mass concentrations.

A single-cell assay for telomere DNA content shows increasing telomere length heterogeneity, as well as increasing mean telomere length in human spermatozoa with advancing age.

PubMed

Antunes, Danielle M F; Kalmbach, Keri H; Wang, Fang; Dracxler, Roberta C; Seth-Smith, Michelle L; Kramer, Yael; Buldo-Licciardi, Julia; Kohlrausch, Fabiana B; Keefe, David L

2015-11-01

The effect of age on telomere length heterogeneity in men has not been studied previously. Our aims were to determine the relationship between variation in sperm telomere length (STL), men's age, and semen parameters in spermatozoa from men undergoing in vitro fertilization (IVF) treatment. To perform this prospective cross-sectional pilot study, telomere length was estimated in 200 individual spermatozoa from men undergoing IVF treatment at the NYU Fertility Center. A novel single-cell telomere content assay (SCT-pqPCR) measured telomere length in individual spermatozoa. Telomere length among individual spermatozoa within an ejaculate varies markedly and increases with age. Older men not only have longer STL but also have more variable STL compared to younger men. STL from samples with normal semen parameters was significantly longer than that from samples with abnormal parameters, but STL did not differ between spermatozoa with normal versus abnormal morphology. The marked increase in STL heterogeneity as men age is consistent with a role for ALT during spermatogenesis. No data have yet reported the effect of age on STL heterogeneity. Based on these results, future studies should expand this modest sample size to search for molecular evidence of ALT in human testes during spermatogenesis.

Jasper Seamount: seven million years of volcanism

USGS Publications Warehouse

Pringle, M.S.; Staudigel, H.; Gee, J.

1991-01-01

Jasper Seamount is a young, mid-sized (690 km3) oceanic intraplate volcano located about 500 km west-southwest of San Diego, California. Reliable 40Ar/39Ar age data were obtained for several milligram-sized samples of 4 to 10 Ma plagioclase by using a defocused laser beam to clean the samples before fusion. Gee and Staudigel suggested that Jasper Seamount consists of a transitional to tholeiitic shield volcano formed by flank transitional series lavas, overlain by flank alkalic series lavas and summit alkalic series lavas. Twenty-nine individual 40Ar/39Ar laser fusion analyses on nine samples confirm the stratigraphy: 10.3-10.0 Ma for the flank transitional series, 8.7-7.5 Ma for the flank alkalic series, and 4.8-4.1 Ma for the summit alkalic series. The alkalinity of the lavas clearly increases with time, and there appear to be 1 to 3 m.y. hiatuses between each series. -from Authors

Population structure and the evolution of sexual size dimorphism and sex ratios in an insular population of Florida box turtles (Terrapene carolina bauri)

USGS Publications Warehouse

Dodd, C.K.

1997-01-01

Hypotheses in the chelonian literature suggest that in species with sexual size dimorphism, the smaller sex will mature at a smaller size and a younger age than the larger sex, sex ratios should be biased in favor of the earlier maturing sex, and deviations from a 1:1 sex ratio result from maturation of the smaller sex at a younger age. I tested these hypotheses using data collected from 1991 to 1995 on an insular (Egmont Key) population of Florida box turtles, Terrapene carolina bauri. Contrary to predictions, the earlier maturing sex (males) grew to larger sizes than the late maturing sex. Males were significantly larger than females in mean carapace length but not mean body mass. Sex ratios were not balanced, favoring the earlier maturing sex (1.6 males:1 female), but the sex-ratio imbalance did not result from faster maturation of the smaller sex. The imbalance in the sex ratio in Egmont Key's box turtles is not the result of sampling biases; it may result from nest placement. Size-class structure and sex ratios can provide valuable insights into the status and trends of populations of long-lived turtles.

Just the right age: well-clustered exposure ages from a global glacial 10Be compilation

NASA Astrophysics Data System (ADS)

Heyman, Jakob; Margold, Martin

2017-04-01

Cosmogenic exposure dating has been used extensively for defining glacial chronologies, both in ice sheet and alpine settings, and the global set of published ages today reaches well beyond 10,000 samples. Over the last few years, a number of important developments have improved the measurements (with well-defined AMS standards) and exposure age calculations (with updated data and methods for calculating production rates), in the best case enabling high precision dating of past glacial events. A remaining problem, however, is the fact that a large portion of all dated samples have been affected by prior and/or incomplete exposure, yielding erroneous exposure ages under the standard assumptions. One way to address this issue is to only use exposure ages that can be confidently considered as unaffected by prior/incomplete exposure, such as groups of samples with statistically identical ages. Here we use objective statistical criteria to identify groups of well-clustered exposure ages from the global glacial "expage" 10Be compilation. Out of ˜1700 groups with at least 3 individual samples ˜30% are well-clustered, increasing to ˜45% if allowing outlier rejection of a maximum of 1/3 of the samples (still requiring a minimum of 3 well-clustered ages). The dataset of well-clustered ages is heavily dominated by ages <30 ka, showing that well-defined cosmogenic chronologies primarily exist for the last glaciation. We observe a large-scale global synchronicity in the timing of the last deglaciation from ˜20 to 10 ka. There is also a general correlation between the timing of deglaciation and latitude (or size of the individual ice mass), with earlier deglaciation in lower latitudes and later deglaciation towards the poles. Grouping the data into regions and comparing with available paleoclimate data we can start to untangle regional differences in the last deglaciation and the climate events controlling the ice mass loss. The extensive dataset and the statistical analysis enables an unprecedented global view on the last deglaciation.

Evaluation of Ages in the Lunar Highlands with Implications for the Evolution of the Moon

NASA Astrophysics Data System (ADS)

Borg, L. E.; Gaffney, A. M.; Carlson, R. W.

2012-12-01

The lunar highlands are composed of rocks from the ferroan anorthosite (FAN) and Mg-suites. These samples have been extensively studied because they record most of the major events associated with the formation and evolution of the Earth's Moon. Despite their potential to constrain the timing of these events, chronologic investigations are often ambiguous; in most cases because absolute ages and/or initial isotopic compositions are inconsistent with stratigraphic and petrologic relationships of various rock suites inferred from mineralogical and geochemical studies. The problem is exacerbated by the fact that most samples are difficult to date due to their small size and nearly monomineralic nature, as well as isotopic disturbances associated with impacts. Here several criteria are used to assess the reliability of lunar ages, including: (1) concordance between multiple chronometers, (2) linearity of individual isochrons, (3) resistance of the chronometers to disruption by impact or contamination, (4) consistency between initial isotopic compositions and the petrogenisis of samples, and (5) reasonableness of the elemental concentrations of mineral fractions. If only those samples that meet 4 out of 5 of these criteria are used to constrain lunar chronology many of the apparent conflicts between chronometry and petrology disappear. For example, this analysis demonstrates that the most ancient ages reported for lunar samples are some of the least reliable. The oldest ages determined on both FAN and Mg-suite highland rocks with confidence are in fact ~4.35 Ga. This age is concordant with 142Nd mare source formation ages and a peak in zircon ages, suggesting it represents a major event at ~4.35 Ga. In contrast, several apparently reliable KREEP model ages are older at ~4.48 Ga. If these older model ages are correct, they may represent the solidification age of the Moon, whereas the 4.35 Ga event could reflect secondary magmatism and cumulate re-equilibration associated with density overturn of primordial magma ocean cumulates.

Low-temperature thermochronology of the Laramide Ranges and eastward translation of shortening in the Sevier Belt, Wyoming, Utah and Montana

NASA Astrophysics Data System (ADS)

Peyton, Sara Lynn

This dissertation contains two studies that use very different techniques to investigate the Mesozoic and Cenozoic tectonics of the western USA. The first study investigates shortening in the Sevier thrust belt of northeast Utah and southwest Wyoming using cross sections and seismic reflection data. The second study investigates the low-temperature thermochronology of the Laramide Ranges using apatite (U-Th)/He dating. We used cross sections and seismic reflection data to investigate bed length discrepancies within the hanging wall of the Absaroka thrust in the Sevier thrust belt of northeast Utah and southwest Wyoming. Restoration of cross sections suggests that there was ˜8-14 km of pre-Absaroka-thrust shortening above the Jurassic Preuss salt detachment, but not below it, in the hanging wall of the Absaroka thrust. Reflection seismic data over the hanging wall of the Crawford thrust show that the Crawford thrust is not offset along the Preuss salt detachment, indicating that the additional shortening on the Absaroka plate was transferred east before main movement on the Crawford thrust. Although early displacement on the Crawford thrust cannot be ruled out as the cause of the extra shortening, surface and subsurface geology suggests slip from the western thrust system (Willard and Lost Creek thrusts) was transferred several tens of kilometers east along the Jurassic Preuss salt detachment between ˜102-90 Ma, to the future location of the Absaroka thrust hanging wall. The lack of deformation of the Crawford thrust on the seismic data, along with shortening and extension estimates from cross sections, also indicate that the magnitude of Paleocene and post-early Eocene shortening on the Medicine Butte thrust was essentially offset by subsequent extension on the middle Eocene to late Oligocene Almy-Acocks normal-fault system. For the second study in this dissertation, we dated 91 borehole and surface samples from Laramide-age, basement-cored uplifts of the Rocky Mountain foreland (Wind River, Beartooth, Bighorn and Laramie Ranges) and the Uncompahgre Uplift using the apatite (U-Th)/He system. Apatite (U-Th)/He ages generally decrease with increasing subsurface depth (decreasing elevation) and most samples show age dispersion ranging from tens to hundreds of Myr. Additionally, several samples show correlations between apatite (U-Th)/He age and effective U concentration (eU = [U] + 0.235[Th]) of the crystal, indicating that radiation damage has affected He diffusivity, and hence (U-Th)/ He age. Many surface and near-surface samples have apatite (U-Th)/He ages that are older than corresponding apatite fission-track ages. Forward modeling of Laramide-type thermal histories using a radiation damage diffusion model showed that (U-Th)/He ages may be widely dispersed, and may be older than corresponding apatite fission-track ages within a fossil He partial retention zone. Most of our samples, however, do not show the correlation between (U-Th)/He age and eU predicted by radiation damage diffusion models. We investigated the influence of both grain size and eU content and show that the effects of grain size can obscure (U-Th)/ He age-eU correlations and, similarly, the effect of eU variation can obscure (U-Th)/ He age-grain size correlations. (U-Th)/He ages that are older than fission-track ages from high peaks in the Wind River Range, and from some samples from the Beartooth Range, are most likely the result of He implantation from high eU phases. Best-fit thermal histories from the inversion of age-eU pairs were extrapolated to other elevations to create model age-elevation profiles for a range of eU concentrations. These model profiles approximate our real data. Inverse modeling of (U-Th)/He age data suggests that rapid exhumation within the Laramide province likely began earlier in the Bighorn Mountains (before ˜71 Ma) than the Beartooth Range (before ˜58 Ma), and that the borehole at the northern end of the Laramie Range penetrated a fault sliver at depth.

Iodine deficiency in children: A comparative study in two districts of south-interior Karnataka, India.

PubMed

Ahmed, Mansoor; Zama, Syed Y; Nagarajarao, Vadiraja; Khan, Mudassir A

2014-01-01

Iodine is an essential component of the hormones produced by the thyroid gland that are essential for mammalian life. Although goiter is the most visible sequelae of iodine deficiency, the major impact of hypothyroidism as a result of iodine deficiency is impaired neurodevelopment, particularly early in life. According to the World Health Organization, it is the single most preventable cause of mental retardation and brain damage. The simplest, most effective and inexpensive preventive method is the consumption of iodized salt. The objective of the following study is to estimate the prevalence of goiter in children in the rural areas of Mysore and Coorg districts in India and estimate iodine levels in salt samples. A cross-sectional study in the age group of 6-12 years, using population proportionate to size systematic sampling method. The total sample size was 10,082: out of which 5337 was from Mysore and the rest from Coorg district. Clinical examination of the thyroid gland was done and salt samples collected for the estimation of Iodine. The total prevalence of goiter was 19.01% in children of 6-12 years in Coorg district and 8.77% in Mysore district and it was more in females than in males. It was observed that iodine deficiency disorders is endemic in both districts, with a prevalence of 19.01% in children aged 6-12 years in Coorg district and 8.77% in Mysore district. Analysis of salt samples suggested that most of the samples were inadequately iodised (73.92% in Coorg and 45.92% in Mysore).

Risk factors for persistent gestational trophoblastic neoplasia.

PubMed

Kuyumcuoglu, Umur; Guzel, Ali Irfan; Erdemoglu, Mahmut; Celik, Yusuf

2011-01-01

This retrospective study evaluated the risk factors for persistent gestational trophoblastic disease (GTN) and determined their odds ratios. This study included 100 cases with GTN admitted to our clinic. Possible risk factors recorded were age, gravidity, parity, size of the neoplasia, and beta-human chorionic gonadotropin levels (beta-hCG) before and after the procedure. Statistical analyses consisted of the independent sample t-test and logistic regression using the statistical package SPSS ver. 15.0 for Windows (SPSS, Chicago, IL, USA). Twenty of the cases had persistent GTN, and the differences between these and the others cases were evaluated. The size of the neoplasia and histopathological type of GTN had no statistical relationship with persistence, whereas age, gravidity, and beta-hCG levels were significant risk factors for persistent GTN (p < 0.05). The odds ratios (95% confidence interval (CI)) for age, gravidity, and pre- and post-evacuation beta-hCG levels determined using logistic regression were 4.678 (0.97-22.44), 7.315 (1.16-46.16), 2.637 (1.41-4.94), and 2.339 (1.52-3.60), respectively. Patient age, gravidity, and beta-hCG levels were risk factors for persistent GTN, whereas the size of the neoplasia and histopathological type of GTN were not significant risk factors.

Size-Frequency Distribution of Small Lunar Craters: Widening with Degradation and Crater Lifetime

NASA Astrophysics Data System (ADS)

Ivanov, B. A.

2018-01-01

The review and new measurements are presented for depth/diameter ratio and slope angle evolution during small ( D < 1 km) lunar impact craters aging (degradation). Comparative analysis of available data on the areal cratering density and on the crater degradation state for selected craters, dated with returned Apollo samples, in the first approximation confirms Neukum's chronological model. The uncertainty of crater retention age due to crater degradational widening is estimated. The collected and analyzed data are discussed to be used in the future updating of mechanical models for lunar crater aging.

Radiographic analysis of vocal tract length and its relation to overall body size in two canid species.

PubMed

Plotsky, K; Rendall, D; Riede, T; Chase, K

2013-09-01

Body size is an important determinant of resource and mate competition in many species. Competition is often mediated by conspicuous vocal displays, which may help to intimidate rivals and attract mates by providing honest cues to signaler size. Fitch proposed that vocal tract resonances (or formants) should provide particularly good, or honest, acoustic cues to signaler size because they are determined by the length of the vocal tract, which in turn, is hypothesized to scale reliably with overall body size. There is some empirical support for this hypothesis, but to date, many of the effects have been either mixed for males compared with females, weaker than expected in one or the other sex, or complicated by sampling issues. In this paper, we undertake a direct test of Fitch's hypothesis in two canid species using large samples that control for age- and sex-related variation. The samples involved radiographic images of 120 Portuguese water dogs Canis lupus familiaris and 121 Russian silver foxes Vulpes vulpes . Direct measurements were made of vocal tract length from X-ray images and compared against independent measures of body size. In adults of both species, and within both sexes, overall vocal tract length was strongly and significantly correlated with body size. Effects were strongest for the oral component of the vocal tract. By contrast, the length of the pharyngeal component was not as consistently related to body size. These outcomes are some of the clearest evidence to date in support of Fitch's hypothesis. At the same time, they highlight the potential for elements of both honest and deceptive body signaling to occur simultaneously via differential acoustic cues provided by the oral versus pharyngeal components of the vocal tract.

Radiographic analysis of vocal tract length and its relation to overall body size in two canid species

PubMed Central

Plotsky, K.; Rendall, D.; Riede, T.; Chase, K.

2013-01-01

Body size is an important determinant of resource and mate competition in many species. Competition is often mediated by conspicuous vocal displays, which may help to intimidate rivals and attract mates by providing honest cues to signaler size. Fitch proposed that vocal tract resonances (or formants) should provide particularly good, or honest, acoustic cues to signaler size because they are determined by the length of the vocal tract, which in turn, is hypothesized to scale reliably with overall body size. There is some empirical support for this hypothesis, but to date, many of the effects have been either mixed for males compared with females, weaker than expected in one or the other sex, or complicated by sampling issues. In this paper, we undertake a direct test of Fitch’s hypothesis in two canid species using large samples that control for age- and sex-related variation. The samples involved radiographic images of 120 Portuguese water dogs Canis lupus familiaris and 121 Russian silver foxes Vulpes vulpes. Direct measurements were made of vocal tract length from X-ray images and compared against independent measures of body size. In adults of both species, and within both sexes, overall vocal tract length was strongly and significantly correlated with body size. Effects were strongest for the oral component of the vocal tract. By contrast, the length of the pharyngeal component was not as consistently related to body size. These outcomes are some of the clearest evidence to date in support of Fitch’s hypothesis. At the same time, they highlight the potential for elements of both honest and deceptive body signaling to occur simultaneously via differential acoustic cues provided by the oral versus pharyngeal components of the vocal tract. PMID:24363497

Empirical test of an illite/muscovite 40Ar/39Ar thermochronometer

NASA Astrophysics Data System (ADS)

Verdel, C.; van der Pluijm, B. A.; Niemi, N. A.; Hall, C. M.

2010-12-01

Minerals which both preserve age information and indicate metamorphic conditions are particularly useful in thermochronology. Variations in sub-greenschist facies metamorphism have traditionally been quantified in terms of the illite to muscovite transition, a transformation which involves the growth of crystallites of increasing thickness at higher metamorphic temperatures. Thickness variations may influence Ar retention within these K-rich minerals, both in nature and during neutron irradiation. Along a transect in the southwestern US from the Grand Canyon to Death Valley, metamorphic conditions of a stratigraphic interval (the Middle Cambrian Bright Angel Shale and laterally equivalent Carrara Fm.) range from zeolite facies in the east to greenschist facies in the west, as determined by estimating illite crystallite thickness with X-ray diffraction. 40Ar/39Ar step-heating experiments were conducted on illite/muscovite-rich, micron to submicron grain sizes of these shales that were encapsulated in quartz tubes prior to irradiation. The proportion of 39Ar expelled during irradiation decreases in these samples as both crystallite thickness and grain size increases. Spectra from the least metamorphosed samples (diagenetic zone) are staircase-shaped and reach maximum ages that appear to reflect the age of detrital muscovite. Spectra from the highest grade samples (epizone) display partial plateaus and yield much younger maximum ages. Based on these findings we conclude that Ar can escape from illite via two processes: loss from low retention sites on crystallite edges and c-axis perpendicular volume diffusion. Based on our empirical data, the closure temperature of illite appears to lie at or near the anchizone-epizone bounday, or roughly 200-300 °C. Illite/muscovite thickness and 40Ar/39Ar data may therefore be useful for studies of detrital muscovite geochronology in very low grade shales and as a thermochronometer for higher grade pelites.

Sizing for the apparel industry using statistical analysis - a Brazilian case study

NASA Astrophysics Data System (ADS)

Capelassi, C. H.; Carvalho, M. A.; El Kattel, C.; Xu, B.

2017-10-01

The study of the body measurements of Brazilian women used the Kinect Body Imaging system for 3D body scanning. The result of the study aims to meet the needs of the apparel industry for accurate measurements. Data was statistically treated using the IBM SPSS 23 system, with 95% confidence (P<0,05) for the inferential analysis, with the purpose of grouping the measurements in sizes, so that a smaller number of sizes can cover a greater number of people. The sample consisted of 101 volunteers aged between 19 and 62 years. A cluster analysis was performed to identify the main body shapes of the sample. The results were divided between the top and bottom body portions; For the top portion, were used the measurements of the abdomen, waist and bust circumferences, as well as the height; For the bottom portion, were used the measurements of the hip circumference and the height. Three sizing systems were developed for the researched sample from the Abdomen-to-Height Ratio - AHR (top portion): Small (AHR < 0,52), Medium (AHR: 0,52-0,58), Large (AHR > 0,58) and from the Hip-to-Height Ratio - HHR (bottom portion): Small (HHR < 0,62), Medium (HHR: 0,62-0,68), Large (HHR > 0,68).

Age, maturation, and population structure of the Humboldt squid Dosidicus gigas off the Peruvian Exclusive Economic Zones

NASA Astrophysics Data System (ADS)

Liu, Bilin; Chen, Xinjun; Chen, Yong; Tian, Siquan; Li, Jianhua; Fang, Zhou; Yang, Mingxia

2013-01-01

Age, maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones (EEZ) during 2008-2010. Estimated ages ranged from 144 to 633 days, confirming that the squid is a short-lived species with longevity no longer than 2 years. Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round. Back-calculated hatching dates for the samples were from January 22nd, 2008 to April 22nd, 2010 with a peak between January and March. Two size-based and two hatching date-based populations could be defined from mantle length (ML) at maturity and back-calculated hatching dates, respectively. Females matured at a larger size than males, and there was a significant difference in ML at maturity between the two hatching groups ( P <0.05). The waters adjacent to 11°S off the Peruvian EEZ may be a potential spawning ground. This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ, which should be considered in the assessment and management of this important resource.

Exploring how to increase response rates to surveys of older people.

PubMed

Palonen, Mira; Kaunonen, Marja; Åstedt-Kurki, Päivi

2016-05-01

To address the special considerations that need to be taken into account when collecting data from older people in healthcare research. An objective of all research studies is to ensure there is an adequate sample size. The final sample size will be influenced by methods of recruitment and data collection, among other factors. There are some special considerations that need to be addressed when collecting data among older people. Quantitative surveys of people aged 60 or over in 2009-2014 were analysed using statistical methods. A quantitative study of patients aged 75 or over in an emergency department was used as an example. A methodological approach to analysing quantitative studies concerned with older people. The best way to ensure high response rates in surveys involving people aged 60 or over is to collect data in the presence of the researcher; response rates are lowest in posted surveys and settings where the researcher is not present when data are collected. Response rates do not seem to vary according to the database from which information about the study participants is obtained or according to who is responsible for recruitment to the survey. Implications for research/practice To conduct coherent studies with older people, the data collection process should be carefully considered.

Effects of aging time and temperature of Fe-1wt.%Cu on magnetic Barkhausen noise and FORC

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

Saleh, Muad; Cao, Yue; Edwards, Danny J.

Magnetic Barkhausen noise (MBN), hysteresis measurements, first order reversal curves (FORC), Vickers microhardness, and Transmission Electron Microscopy (TEM) analyses were performed on Fe-1wt.%Cu (Fe-Cu) samples isothermally aged at 700°C for 0.5 – 25 hours to obtain samples with different sized Cu precipitates and dislocation structures. Fe-Cu is used to simulate the thermal and irradiation-induced defects in copper-containing nuclear reactor materials such as cooling system pipes and pressure vessel materials. The sample series showed an initial increase followed by a decrease in hardness and coercivity with aging time, which is explained by Cu precipitates formation and growth as observed by TEMmore » measurements. Further, the MBN envelope showed a continuous decrease in its magnitude and the appearance of a second peak with aging. Also, FORC diagrams showed multiple peaks whose intensity and location changed for different aging time. The changes in FORC diagrams are attributed to combined changes of the magnetic behavior due to Cu precipitate characteristics and dislocation structure. A second series of samples aged at 850°C, which is above the solid solution temperature of Fe-Cu, was studied to isolate the effects of dislocations. These samples showed a continuous decrease in MBN amplitude with aging time although the coercivity and hardness did not change significantly. The decrease of MBN amplitude and the appearance of the second MBN envelope peak are attributed to the changes in dislocation density and structure. This study shows that the effect of dislocations on MBN and FORC of Fe-Cu materials can vary significantly and should be considered in interpreting magnetic signatures.« less

Lexical development in Korean: vocabulary size, lexical composition, and late talking.

PubMed

Rescorla, Leslie; Lee, Youn Mi Cathy; Lee, Youn Min Cathy; Oh, Kyung Ja; Kim, Young Ah

2013-04-01

In this study, the authors aimed to compare vocabulary size, lexical composition, and late talking in large samples of Korean and U.S. children ages 18-35 months. Data for 2,191 Korean children (211 children recruited "offline" through preschools, and 1,980 recruited "online" via the Internet) and 274 U.S. children were obtained using the Language Development Survey (LDS). Mean vocabulary size was slightly larger in the offline than the online group, but the groups were acquiring almost identical words. Mean vocabulary size did not differ by country; girls and older children had larger vocabularies in both countries. The Korean-U.S. Q correlations for percentage use of LDS words (.53 and .56) indicated considerable concordance across countries in lexical composition. Noun dominance was as large in Korean lexicons as in U.S. lexicons. About half of the most commonly reported words for the Korean and U.S. children were identical. Lexicons of late talkers resembled those of typically developing younger children in the same sample. Despite linguistic and discourse differences between Korean and English, LDS findings indicated considerable cross-linguistic similarity with respect to vocabulary size, lexical composition, and late talking.

Enhanced positron trapping by Ag nanoclusters at low temperatures: A challenge of positron sensitivity to quantum dots

NASA Astrophysics Data System (ADS)

Zou, B.; Qi, N.; Liu, Z. W.; Chen, Z. Q.; Liu, H. Q.; Yi, D. Q.; Tang, Z.

2017-03-01

Microstructure evolution of three Al-Ag alloys with different Ag contents (1 wt. % Ag, 5 wt. % Ag, and 15 wt. % Ag) was studied by positron annihilation spectroscopy during the aging process. In situ measurements of the positron lifetime and Doppler broadening of annihilation radiation indicate the fast formation of Ag-rich clusters during natural aging of the alloys. The formation of Ag-rich clusters was further confirmed by coincidence Doppler broadening measurements. The Ag signal reflected by the Coincidence Doppler broadening spectrum increases with increasing Ag content and is further enhanced after subsequent artificial aging at 140 °C. This might be due to the increase in the size of Ag clusters. The temperature dependence of the Doppler broadening spectra between 10 K and 290 K was measured for the Al-Ag alloys after natural and artificial aging. Detrapping of positrons from Ag clusters with increasing temperature was observed for all the three Al-Ag alloys after natural aging and for the Al-1 wt. % Ag after artificial aging. This indicates that Ag clusters act as shallow positron trapping centers. The thermal detrapping of positrons becomes ambiguous with increasing Ag content in the alloy and is nearly invisible in the artificially aged Al-5 wt. % Ag and Al-15 wt. % Ag. The positron binding energy of the Ag cluster is roughly estimated to be about 18.8 meV and 50 meV in the Al-1 wt. % Ag sample after natural aging and artificial aging at 140 °C, respectively, which suggests that the confinement of positrons in the quantum-dot like state depends on the size or chemical composition of clusters. Theoretical calculations confirm positron trapping by Ag nanoclusters, and the confinement of positrons is enhanced with increasing Ag cluster size.

Hemoglobin status of non-school going adolescent girls in three districts of Orissa, India.

PubMed

Bulliyy, Gandham; Mallick, Gitanjali; Sethy, Girija Sankar; Kar, Santanu Kumar

2007-01-01

Anemia is a major public health problem in young children and pregnant women in SouthEast Asia, but a paucity of data on anemia in adolescent girls in India. Studies are lacking on the entire non-school going adolescent population. To determine the prevalence of anemia in non-school going adolescent girls and the association between hemoglobin (Hb) concentration and socioeconomic and nutritional factors. A cross-sectional community study conducted on a sample of 1937 healthy adolescent girls aged 11-19 years from three districts of Orissa, India. Sample size was determined using a probability proportionate to size cluster sampling. The adolescent girls were interviewed and anthropometric measurements were collected. The Hb estimation was carried out in capillary blood samples using the cyanmethemoglobin method. Anemia and nutritional status were evaluated according to standard procedures. The mean Hb concentration was 9.7 +/- 1.4 g/dL (range, 4.5-13.4 g/dL). Of the total adolescent girls, 1869 (96.5%) were anemic (Hb < 12.0 g/dL), of which, 45.2%, 46.9% and 4.4% had mild, moderate, and severe anemia, respectively. A significant curvilinear relation was found between Hb concentration and age, with the nadir of the curve occurring in the 12-14 years age group. Girls from Bargarh district had significantly lower mean Hb levels than those from the Jajpur and Khurda districts. Significant positive associations were found between Hb concentration and pre-menarche, community, education levels of girls and their parents' family income, body mass index, and mid-upper arm circumference. This study revealed that prevalence of anemia was extremely high in non-school going adolescent girls (most were moderately anemic) and stressed the need for more research and public health interventions.

Forest Health Monitoring in Vermont, 1996-1999

Treesearch

Northeastern Research Station

2002-01-01

Vermont forests vary in size and age class. Trees are distributed evenly between hardwood and softwood species but hardwood dominated the seedling sample. Most of the trees are healthy, with full crowns (low transparency, high density), little dieback and little damage. White and green ash had higher transparencies and lower crown densities possibly explained by the...

Children's Ideas of Animals' Internal Structures

ERIC Educational Resources Information Center

Prokop, Pavol; Prokop, Matej; Tunnicliffe, Sue Dale; Diran, Carla

2007-01-01

Children's understanding about animal internal structure can be affected by several factors which are poorly understood by teachers. We conducted a large sample study (n=702) of children aged 6-16 years (Grades 1-9) examining children's responses to animals of various size, species and dimensions (2D and 3D objects), and exploring factors which…

Correlates of Sexual Abuse and Smoking among French Adults

ERIC Educational Resources Information Center

King, Gary; Guilbert, Philippe; Ward, D. Gant; Arwidson, Pierre; Noubary, Farzad

2006-01-01

Objective: The goal of this study was to examine the association between sexual abuse (SA) and initiation, cessation, and current cigarette smoking among a large representative adult population in France. Method: A random sample size of 12,256 adults (18-75 years of age) was interviewed by telephone concerning demographic variables, health…

The King Pre-Retirement Checklist: Assessing Differences in Pre-Retirement Planning.

ERIC Educational Resources Information Center

Zitzow, Darryl; King, Donald N.

In an effort to assess the retirement preparedness of Midwestern populations above the age of 28, the King Pre-Retirement Checklist was administered to a sampling of 458 persons randomly selected and proportionally stratified by geographic location and community size. Factors examined were financial, social, family cohesion, mobility/health,…

Analyzing International Students' Study Anxiety in Higher Education

ERIC Educational Resources Information Center

Khoshlessan, Rezvan; Das, Kumer Pial

2017-01-01

The purpose of this study is to explore international students' study anxiety in a mid-sized public four-year university in Southeast Texas by comparing their existing study anxiety along lines of nationality, gender, age, major, degree, and stage of education. The subjects were selected using a convenience sample during the Spring of 2013. The…

Characterizing dispersal patterns in a threatened seabird with limited genetic structure

Treesearch

Laurie A. Hall; Per J. Palsboll; Steven R. Beissinger; James T. Harvey; Martine Berube; Martin G. Raphael; Kim Nelson; Richard T. Golightly; Laura McFarlane-Tranquilla; Scott H. Newman; M. Zachariah Peery

2009-01-01

Genetic assignment methods provide an appealing approach for characterizing dispersal patterns on ecological time scales, but require sufficient genetic differentiation to accurately identify migrants and a large enough sample size of migrants to, for example, compare dispersal between sexes or age classes. We demonstrate that assignment methods can be rigorously used...

Corpus Callosum Area in Children and Adults with Autism

ERIC Educational Resources Information Center

Prigge, Molly B. D.; Lange, Nicholas; Bigler, Erin D.; Merkley, Tricia L.; Neeley, E. Shannon; Abildskov, Tracy J.; Froehlich, Alyson L.; Nielsen, Jared A.; Cooperrider, Jason R.; Cariello, Annahir N.; Ravichandran, Caitlin; Alexander, Andrew L.; Lainhart, Janet E.

2013-01-01

Despite repeated findings of abnormal corpus callosum structure in autism, the developmental trajectories of corpus callosum growth in the disorder have not yet been reported. In this study, we examined corpus callosum size from a developmental perspective across a 30-year age range in a large cross-sectional sample of individuals with autism…

The Relationships among Adult Affective Factors, Engagement in Science, and Scientific Competencies

ERIC Educational Resources Information Center

Tsai, Chun-Yen; Li, Yuh-Yuh; Cheng, Ying-Yao

2017-01-01

This study investigated the relationship among adult affective factors, engagement in science, and scientific competencies. Probability proportional to size sampling was used to select 504 participants between the ages of 18 and 70 years. Data were collected through individual face-to-face interviews. The results of hierarchical regression…

Developmental Stuttering in Children Who Are Hard of Hearing

ERIC Educational Resources Information Center

Arena, Richard M.; Walker, Elizabeth A.; Oleson, Jacob J.

2017-01-01

Purpose: A number of studies with large sample sizes have reported lower prevalence of stuttering in children with significant hearing loss compared to children without hearing loss. This study used a parent questionnaire to investigate the characteristics of stuttering (e.g., incidence, prevalence, and age of onset) in children who are hard of…

White sucker (Catostomus commersoni) growth and sexual maturation in pulp mill-contaminated and reference rivers

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

Gagnon, M.M.; Bussieres, D.; Dodson, J.J.

1995-02-01

Induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity and accumulation of chlorophenolic compounds typical of bleached-kraft mill effluent (BKME) in fish sampled downstream of a pulp mill on the St. Maurice River, Quebec, Canada, provided evidence of chemical exposure to BKME. In comparison, fish sampled over the same distances and in similar habitats in a noncontaminated reference river, the Gatineau River, demonstrated low EROD activity and contamination levels. Accelerated growth of white suckers occurred between 2 and 10 years of age in both rivers at downstream stations relative to upstream stations, suggesting the existence of gradients of nutrient enrichment independent of BKMEmore » contamination. The impact of BKME exposure was expressed as reduced investment in reproduction, as revealed by greater length at maturity, reduced gonad size, and more variable fecundity. These effects were not obvious in simple upstream-downstream comparisons, but became evident when fish from the uncontaminated Gatineau River showed increased gonadal development and reduced age and size at maturity in response to enhanced growth rates.« less

Geology and description of thorium and rare-earth deposits in the southern Bear Lodge Mountains, northeastern Wyoming

USGS Publications Warehouse

Staatz, M.H.

1983-01-01

The Bear Lodge Mountains are a small northerly trending range approximately 16 km northwest of the Black Hills in the northeast corner of Wyoming. Thorium and rare-earth deposits occur over an area of 16 km 2 in the southern part of these mountains. These deposits occur in the core of the Bear Lodge dome in a large multiple intrusive body made up principally of trachyte and phonolite. Two types of deposits are recognized: disseminated deposits and veins. The disseminated deposits are made up of altered igneous rocks cut by numerous crisscrossing veinlets. The disseminated deposits contain thorium and rare-earth minerals in a matrix consisting principally of potassium feldspar, quartz, and iron and manganese oxides. Total rare-earth content of these deposits is about 27 times that of the thorium content. The general size and shape of the disseminated deposits were outlined by making a radiometric map using a scintillation counter of the entire Bear Lodge core, an area of approximately 30 km 2 . The most favorable part of this area, which was outlined by the 40 countJs (count-per-second) isograd on the radiometric map, was sampled in detail. A total of 341 samples were taken over an area of 10.6 km 2 and analyzed for as many as 60 elements. Rare earths and thorium are the principal commodities of interest in these deposits. Total rare-earth content of these samples ranged from 47 to 27,145 ppm (parts per million), and the thorium content from 9.3 to 990 ppm. The amount of total rare earths of individual samples shows little correlation with that of thorium. Contour maps were constructed using the analytical data for total rare earths, thorium, uranium, and potassium. The total rare-earth and thorium maps can be used to define the size of the deposits based on what cut-off grade may be needed during mining. The size is large as the 2,000 ppm total rare-earth isograd encloses several areas that total 3.22 km 2 in size, and the 200 ppm thorium isograd encloses several areas that total 1.69 km 2 . These deposits could be mined by open pit. The Bear Lodge disseminated deposits have one of the largest resources of both total rare earths and thorium in the United States, and although the grade of both commodities is lower than some other deposits, their large size and relative cheapness of mining make them an important future resource. Vein deposits in the Bear Lodge Mountains include all tabular bodies at least 5 cm thick. Twenty-six veins were noted in this area. These veins are thin and short; the longest vein was traced for only 137 m. Minerals vary greatly in the amount present. Gangue minerals are commonly potassium feldspar, quartz, or cristobalite intermixed with varying amounts of limonite, hematite, and various manganese oxides. Rare earths and thorium occur in the minerals monazite, brockite, and bastnaesite. Thorium content of 35 samples ranged from 0.01 to 1.2 percent, and the total rare-earth content of 21 samples from 0.23 to 9.8 percent. Indicated reserves were calculated to a depth of one-third the exposed length of the vein. Inferred reserves lie in a block surrounding indicated reserves. Indicated reserves of all veins are only 50 t of Th0 2 and 1,360 t of total rare-earth oxides; inferred reserves are 250 t of Th0 2 and 6,810 t of total rare-earth oxides. The Bear Lodge dome, which underlies the greater part of this area, is formed by multiple intrusive bodies of Tertiary age that dome up the surrounding sedimentary rocks. In the southern part of the core, the younger intrusive bodies surround and partly replace a granite of Precambrian age. This granite is approximately 2.6 b.y. old. The sedimentary rocks around the core are (from oldest to youngest): Deadwood Formation of Late Cambrian and Early Ordovician age, Whitewood Limestone of Late Ordovician age, Pahasapa Limestone of Early Mississippian age, Minnelusa Sandstone of Pennsylvanian and Early Permian age, Opeche Formation of Permian age, Minnek

Constraints on Exposure Ages of Lunar and Asteroidal Regolith Particles

NASA Technical Reports Server (NTRS)

Berger, Eve L.; Keller, Lindsay P

2014-01-01

Mineral grains in lunar and asteroidal regolith samples provide a unique record of their interaction with the space environment. Exposure to the solar wind results in implantation effects that are preserved in the rims of grains (typically the outermost 100 nm), while impact processes result in the accumulation of vapor-deposited elements, impact melts and adhering grains on particle surfaces. These processes are collectively referred to as space weathering. A critical element in the study of these processes is to determine the rate at which these effects accumulate in the grains during their space exposure. For small particulate samples, one can use the density of solar flare particle tracks to infer the length of time the particle was at the regolith surface (i.e., its exposure age). We have developed a new technique that enables more accurate determination of solar flare particle track densities in mineral grains <50 micron in size that utilizes focused ion beam (FIB) sample preparation combined with transmission electron microscopy (TEM) imaging. We have applied this technique to lunar soil grains from the Apollo 16 site (soil 64501) and most recently to samples from asteroid 25143 Itokawa returned by the Hayabusa mission. Our preliminary results show that the Hayabusa grains have shorter exposure ages compared to typical lunar soil grains. We will use these techniques to re-examine the track density-exposure age calibration from lunar samples reported by Blanford et al. (1975).

BODY SIZE-SPECIFIC EFFECTIVE DOSE CONVERSION COEFFICIENTS FOR CT SCANS.

PubMed

Romanyukha, Anna; Folio, Les; Lamart, Stephanie; Simon, Steven L; Lee, Choonsik

2016-12-01

Effective dose from computed tomography (CT) examinations is usually estimated using the scanner-provided dose-length product and using conversion factors, also known as k-factors, which correspond to scan regions and differ by age according to five categories: 0, 1, 5, 10 y and adult. However, patients often deviate from the standard body size on which the conversion factor is based. In this study, a method for deriving body size-specific k-factors is presented, which can be determined from a simple regression curve based on patient diameter at the centre of the scan range. Using the International Commission on Radiological Protection reference paediatric and adult computational phantoms paired with Monte Carlo simulation of CT X-ray beams, the authors derived a regression-based k-factor model for the following CT scan types: head-neck, head, neck, chest, abdomen, pelvis, abdomen-pelvis (AP) and chest-abdomen-pelvis (CAP). The resulting regression functions were applied to a total of 105 paediatric and 279 adult CT scans randomly sampled from patients who underwent chest, AP and CAP scans at the National Institutes of Health Clinical Center. The authors have calculated and compared the effective doses derived from the conventional age-specific k-factors with the values computed using their body size-specific k-factor. They found that by using the age-specific k-factor, paediatric patients tend to have underestimates (up to 3-fold) of effective dose, while underweight and overweight adult patients tend to have underestimates (up to 2.6-fold) and overestimates (up to 4.6-fold) of effective dose, respectively, compared with the effective dose determined from their body size-dependent factors. The authors present these size-specific k-factors as an alternative to the existing age-specific factors. The body size-specific k-factor will assess effective dose more precisely and on a more individual level than the conventional age-specific k-factors and, hence, improve awareness of the true exposure, which is important for the clinical community to understand. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Age-related effects in the neocortical organization of chimpanzees: gray and white matter volume, cortical thickness, and gyrification.

PubMed

Autrey, Michelle M; Reamer, Lisa A; Mareno, Mary Catherine; Sherwood, Chet C; Herndon, James G; Preuss, Todd; Schapiro, Steve J; Hopkins, William D

2014-11-01

Among primates, humans exhibit the most profound degree of age-related brain volumetric decline in particular regions, such as the hippocampus and the frontal lobe. Recent studies have shown that our closest living relatives, the chimpanzees, experience little to no volumetric decline in gray and white matter over the adult lifespan. However, these previous studies were limited with a small sample of chimpanzees of the most advanced ages. In the present study, we sought to further test for potential age-related decline in cortical organization in chimpanzees by expanding the sample size of aged chimpanzees. We used the BrainVisa software to measure total brain volume, gray and white matter volumes, gray matter thickness, and gyrification index in a cross-sectional sample of 219 captive chimpanzees (8-53 years old), with 38 subjects being 40 or more years of age. Mean depth and cortical fold opening of 11 major sulci of the chimpanzee brains were also measured. We found that chimpanzees showed increased gyrification with age and a cubic relationship between age and white matter volume. For the association between age and sulcus depth and width, the results were mostly non-significant with the exception of one negative correlation between age and the fronto-orbital sulcus. In short, results showed that chimpanzees exhibit few age-related changes in global cortical organization, sulcus folding and sulcus width. These findings support previous studies and the theory that the age-related changes in the human brain is due to an extended lifespan. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of Microvascularity by CD34 Expression in Esophagus and Oral Squamous Cell Carcinoma.

PubMed

Shahsavari, Fatemeh; Farhadi, Sareh; Sadri, Donia; Sedehi, Marzieh

2015-06-01

The present study was scheduled to evaluate microvascularity by CD34 expression in esophagus and oral squamous cell carcinoma. This study was scheduled using 40 paraffin blocked samples including 20 of oral SCC and 20 of esophagus ones and Immunohistochemical staining was conducted using CD34 monoclonal antibody. Exact fisher test was used to evaluate frequency of expression between two studied groups. There was significant correlation between age and tumor size with CD34 expression in oral SCC samples (p < 0.05) and no significant correlation between sex and tumor differentiation level (grading) (p > 0.05). Also, there was no significant correlation between age, sex, tumor size and tumor differentiation level (grading) with CD34 expression in esophagus SCC samples (p > 0.05). There was no significant difference of CD34 expression frequency in oral and esophagus SCC (p = 0/583). Finally, CD34 expression was reported 'high' for major cases of esophagus and oral SCCs. It seems, other angiogenetic or nonangiogenetic factors except CD34 may play more important role and explain the different clinical behavior of SCC at recent different locations. Other factors would be considered along with CD34 expression to interpret different clinical behavior of SCC at recent different locations.

Descartes region - Evidence for Copernican-age volcanism.

NASA Technical Reports Server (NTRS)

Head, J. W., III; Goetz, A. F. H.

1972-01-01

A model that suggests that the high-albedo central region of the Descartes Formation was formed by Copernican-age volcanism was developed from Orbiter photography, Apollo 12 multispectral photography, earth-based spectrophotometry, and thermal IR and radar data. The bright surface either is abundant in centimeter-sized rocks or is formed from an insulating debris layer overlying a surface with an abundance of rocks in the 1- to 20-cm size range. On the basis of these data, the bright unit is thought to be a young pyroclastic deposit mantling older volcanic units of the Descartes Formation. Since the Apollo 16 target point is only 50 km NW of the central part of this unit, evidence for material associated with this unique highland formation should be searched for in returned soil and rock samples.

Comorbid Visual and Psychiatric Disabilities Among the Chinese Elderly: A National Population-Based Survey.

PubMed

Guo, Chao; Wang, Zhenjie; Li, Ning; Chen, Gong; Zheng, Xiaoying

2017-12-01

To estimate the prevalence of, and association between, co-morbid visual and psychiatric disabilities among elderly (>65 years-of-age) persons in China. Random representative samples were obtained using multistage, stratified, cluster sampling, with probabilities proportional to size. Standard weighting procedures were used to construct sample weights that reflected this multistage, stratified cluster sampling survey scheme. Logistic regression models were used to elucidate associations between visual and psychiatric disabilities. Among the Chinese elderly, >160,000 persons have co-morbid visual and psychiatric disabilities. The weighted prevalence among this cohort is 123.7 per 100,000 persons. A higher prevalence of co-morbid visual and psychiatric disabilities was found in the oldest-old (p<0.001); women (65-79 years-of-age, p=0.001; ≥80 years-of-age, p=0.004); illiterate (65-79 years-of-age, p<0.001; ≥80 years-of-age, p=0.02); and single elders (65-79 years-of-age, p=0.01; ≥80 years-of-age, p=0.001). Presence of a visual disability was significantly associated with a higher risk of having a psychiatric disability among persons aged ≥80 years-of-age [adjusted odds ratio, 1.24; 95% confidence interval (CI), 1.03-1.54]. A significant number of Chinese elderly persons were living with co-morbid visual and psychiatric disabilities. To address the challenge of these co-morbid disorders among Chinese elders, it is incumbent upon the government to implement additional and more comprehensive prevention and rehabilitation strategies for health-care systems, reinforce health promotion among the elderly, and improve accessibility to health-care services.

Sociobehavioral Factors Associated with Caries Increment: A Longitudinal Study from 24 to 36 Months Old Children in Thailand

PubMed Central

Peltzer, Karl; Mongkolchati, Aroonsri; Satchaiyan, Gamon; Rajchagool, Sunsanee; Pimpak, Taksin

2014-01-01

The aim of this study is to investigate sociobehavioral risk factors from the prenatal period until 36 months of age, and the caries increment from 24 to 36 months of the child in Thailand. The data utilized in this study come from the prospective cohort study of Thai children (PCTC) from prenatal to 36 months of the child in Mueang Nan district, Northern Thailand. The total sample size recruited was 783 infants. The sample size with dental caries data was 603 and 597, at 24 months and at 36 months, respectively. The sample size of having two assessment points with a dental examination (at 24 months and at 36 months) was 597. Results indicate that the caries increment was 52.9%, meaning from 365 caries free children at 24 months 193 had developed dental caries at 36 months. The prevalence of dental caries was 34.2% at 24 months (n = 206) and 68.5% at 36 months of age (n = 409). In bivariate analysis, higher education of the mother, lower household income, bottle feeding of the infant, frequent sweet candy consumptions, and using rain or well water as drinking water were associated with dental caries increment, while in multivariate conditional logistic regression analysis lower household income, higher education of the mother, and using rain or well water as drinking water remained associated with dental caries increment. In conclusion, a very significant increase in caries development was observed, and oral health may be influenced by sociobehavioural risk factors. PMID:25329535

Modifications of the Mesoscopic Structure of Cellulose in Paper Degradation

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

Missori, Mauro; Bicchieri, Marina; Mondelli, Claudia

2006-12-08

Paper is the main component of a huge quantity of cultural heritage. It is primarily composed of cellulose that undergoes significant degradation with the passage of time. By using small angle neutron scattering (SANS), we investigated cellulose's supramolecular structure, which allows access to degradation agents, in ancient and modern samples. For the first time, SANS data were interpreted in terms of water-filled pores, with their sizes increasing from 1.61 nm up to 1.97 nm in natural and artificially aged papers. The protective effect of gelatine sizing was also observed.

Modifications of the Mesoscopic Structure of Cellulose in Paper Degradation

NASA Astrophysics Data System (ADS)

Missori, Mauro; Mondelli, Claudia; de Spirito, Marco; Castellano, Carlo; Bicchieri, Marina; Schweins, Ralf; Arcovito, Giuseppe; Papi, Massimiliano; Castellano, Agostina Congiu

2006-12-01

Paper is the main component of a huge quantity of cultural heritage. It is primarily composed of cellulose that undergoes significant degradation with the passage of time. By using small angle neutron scattering (SANS), we investigated cellulose’s supramolecular structure, which allows access to degradation agents, in ancient and modern samples. For the first time, SANS data were interpreted in terms of water-filled pores, with their sizes increasing from 1.61 nm up to 1.97 nm in natural and artificially aged papers. The protective effect of gelatine sizing was also observed.

Proteoglycan depletion and size reduction in lesions of early grade chondromalacia of the patella.

PubMed Central

Väätäinen, U; Häkkinen, T; Kiviranta, I; Jaroma, H; Inkinen, R; Tammi, M

1995-01-01

OBJECTIVE--To determine the content and molecular size of proteoglycans (PGs) in patellar chondromalacia (CM) and control cartilages as a first step in investigating the role of matrix alterations in the pathogenesis of this disease. METHODS--Chondromalacia tissue from 10 patients was removed with a surgical knife. Using identical techniques, apparently healthy cartilage of the same site was obtained from 10 age matched cadavers (mean age 31 years in both groups). Additional pathological cartilage was collected from 67 patients with grades II-IV CM (classified according to Outerbridge) using a motorised shaver under arthroscopic control. The shaved cartilage chips were collected with a dense net from the irrigation fluid of the shaver. The content of tissue PGs was determined by Safranin O precipitation or uronic acid content, and the molecular size by mobility on agarose gel electrophoresis. RESULTS--The mean PG content of the CM tissue samples with a knife was dramatically reduced, being only 15% of that in controls. The cartilage chips collected from shaving operations of grades II, III, and IV CM showed a decreasing PG content: 9%, 5%, and 1% of controls, respectively. Electrophoretic analysis of PGs extracted with guanidium chloride from the shaved tissue samples suggested a significantly reduced size of aggrecans in the mild (grade II) lesions. CONCLUSION--These data show that there is already a dramatic and progressive depletion of PGs in CM grade II lesions. This explains the softening of cartilage, a typical finding in the arthroscopic examination of CM. The PG size reduction observed in grade II implicates proteolytic attack as a factor in the pathogenesis of CM. Images PMID:7492223

Improved sample preparation and counting techniques for enhanced tritium measurement sensitivity

NASA Astrophysics Data System (ADS)

Moran, J.; Aalseth, C.; Bailey, V. L.; Mace, E. K.; Overman, C.; Seifert, A.; Wilcox Freeburg, E. D.

2015-12-01

Tritium (T) measurements offer insight to a wealth of environmental applications including hydrologic tracking, discerning ocean circulation patterns, and aging ice formations. However, the relatively short half-life of T (12.3 years) limits its effective age dating range. Compounding this limitation is the decrease in atmospheric T content by over two orders of magnitude (from 1000-2000 TU in 1962 to < 10 TU currently) since the cessation of above ground nuclear testing in the 1960's. We are developing sample preparation methods coupled to direct counting of T via ultra-low background proportional counters which, when combined, offer improved T measurement sensitivity (~4.5 mmoles of H2 equivalent) and will help expand the application of T age dating to smaller sample sizes linked to persistent environmental questions despite the limitations above. For instance, this approach can be used to T date ~ 2.2 mmoles of CH4 collected from sample-limited systems including microbial communities, soils, or subsurface aquifers and can be combined with radiocarbon dating to distinguish the methane's formation age from C age in a system. This approach can also expand investigations into soil organic C where the improved sensitivity will permit resolution of soil C into more descriptive fractions and provide direct assessments of the stability of specific classes of organic matter in soils environments. We are employing a multiple step sample preparation system whereby organic samples are first combusted with resulting CO2 and H2O being used as a feedstock to synthesize CH4. This CH4 is mixed with Ar and loaded directly into an ultra-low background proportional counter for measurement of T β decay in a shallow underground laboratory. Analysis of water samples requires only the addition of geologic CO2 feedstock with the sample for methane synthesis. The chemical nature of the preparation techniques enable high sample throughput with only the final measurement requiring T decay with total sample analysis time ranging from 2 -5 weeks depending on T content.

Earthquake-ponded sediments as a high-resolution archive of Anthropocene climate change on the Fuyun Fault (Xinjiang, China).

NASA Astrophysics Data System (ADS)

Chua, Stephen; Gouramanis, Chris; Etchebes, Marie; Klinger, Yann; Gao, Mingxing; Switzer, Adam; Tapponnier, Paul

2016-04-01

High-resolution, late-Holocene climate patterns in arid central Asia, in particular the behaviour of the Asian Monsoon and occurrences of precipitation events, are not yet fully understood. In particular, few high-resolution palaeoenvironmental and palaeoclimate studies are available from the Junggar-Altay region in the Xinjiang Province, northwestern China. This area is tectonically active and the last large earthquake (Mw 7.9) occurred along the Fuyun strike-slip fault in 1931, resulting in ˜6m of right-lateral movement. South of the epicentre at Karaxingar, this earthquake resulted in the construction of large scarp-bounded ponds (46o43'N, 89o55'E) now filled with sediment. Sediment samples were collected every centimetre at a two-meter deep trench where the main pond was the deepest. The majority of the AMS 14C ages of charcoal and plant fibre samples are modern (56±34 to 171±34 yr BP) with the exception of a few much older carbon (842±26 to 2017±26 yr BP) at the base of the trench. The post-1931 age of the pond is validated by the 137Cs and 210Pb age-depth chronology. Each sediment sample was analysed for organic, carbonate and clastic contents and particle-size. This high-resolution analysis revealed eleven upward-fining sequences, with three prominent grain size peaks at depths of 1.7m, 0.95m and 0.6m below ground surface, suggesting three major modern precipitation events. The 11 grain-size peaks since 1931 in the pond coincide with 11 periods of increased precipitation measured in high-elevation tree-ring records ˜50 km north of the pond. Thus, low-altitude post-seismic sedimentary depocentres provide excellent high-resolution palaeoclimate archives that can fill a significant data gap where other proxy records are not available.

Tracing the Origins of Coarse Sediment in Steep Mountain Catchments

NASA Astrophysics Data System (ADS)

Lukens, C. E.; Riebe, C. S.; Shuster, D. L.; Sklar, L. S.; Beyeler, J. D.

2011-12-01

Where does coarse sediment come from? How long does it persist in channels? What can the origins of sediment tell us about erosional processes and particle comminution in hillslope soils and mountain streams? To address these questions, we present new apatite-helium (AHe) ages from coarse sediment in steep streams of the Sierra Nevada, California. The evolution of grain size in sediment reflects both the physical and chemical breakdown of particles as they travel downstream. It also should reflect the dominant mechanisms of landscape evolution within a watershed. Previous studies have exploited detrital thermochronology in tracing the origins of sand-sized particles; the approach uses AHe age distributions in the sand as a geochemical fingerprint that can be compared with age-elevation relationships in bedrock as an indicator of provenance. In steep catchments, however, sand-sized particles comprise only a fraction of the sediment on the bed, and therefore tell only part of the erosional story. Much can be learned by examining age distributions of coarser grain sizes. Source elevations of coarse particles, for instance, may help reveal the relative importance of erosional mechanisms. For example, if boulders are sourced at high elevations, rock fall and debris flows likely dominate their transport. Conversely, if boulders are sourced only at lower elevations (nearer the sample location), they are more likely produced locally, and thus break down in place. We show how hypotheses such as these can be tested using detrital thermochronology on coarse sediment. We show how our analysis of detrital apatite can be coupled with a numerical model of the evolution of grain-size distributions by particle breakdown and input from slopes. We elaborate on how this approach can shed new quantitative light on processes of sediment production, transport, and breakdown in mountainous settings.

Growth dynamics of Saffron cod (Eleginus gracilis) and Arctic cod (Boreogadus saida) in the Northern Bering and Chukchi Seas

NASA Astrophysics Data System (ADS)

Helser, T.; Anderl, D.

2016-02-01

Saffron cod (Eleginus gracilis) and Arctic cod (Boreogadus saida) are two circumpolar gadids that serve as critically important species responsible for energy transfer in Arctic food webs of the northern Bering and Chukchi Seas. To understand the potential effects of sea ice loss and warming temperatures on these species' basic life history, information such as growth is needed. Yet to date, limited effort has been dedicated to the study of their growth dynamics. Based on a large sample of otoliths collected in the first comprehensive ecosystem integrated survey in the northern Bering and Chukchi Seas, procedures were developed to reliably estimate age from otolith microstructure and were used to study the growth dynamics of saffron and Arctic cod. Saffron cod attained larger asymptotic sizes (L∞ = 363 mm) and achieved their maximum size at a faster rate (K = 0.378) than Arctic cod (L∞ = 209 mm; K = 0.312). For both species, regional differences in growth were found (p<0.01). Saffron cod grew to a significantly larger size at age in the northern Bering Sea when compared to the Chukchi Sea, particularly at younger ages. Arctic cod grew to smaller a asymptotic size but at faster rates in the more northerly central (L∞ = 197 mm; K = 0.324) and southern Chukchi Sea (L∞ = 221 mm; K = 0.297) when compared to the northern Bering Sea (L∞ = 266 mm; K = 0.171), suggesting a possible cline in growth rates with more northerly latitudes. A 30 year retrospective comparison of age data indicate that both species exhibited a decline is maximum size accompanied by higher instantaneous rates growth in more recent years.

Sex, age, spleen size, and kidney fat of red deer relative to infection intensities of the lungworm Elaphostrongylus cervi

NASA Astrophysics Data System (ADS)

Vicente, J.; Pérez-Rodríguez, L.; Gortazar, C.

2007-07-01

We analyzed the relationships among spleen size, body condition (measured as kidney fat), and larval counts of the nematode Elaphostrongylus cervi in red deer ( Cervus elaphus). The aim was to investigate the interaction between host body condition and intensity of infection with parasites. As red deer are highly polygynous, we also tested whether these relationships varied with sex and age of the hosts. Kidney fat and spleen size were positively correlated in subadults (2-3 years old) and adults (>3 years old), but not in calves (<1 year old) or yearlings (1-2 years old). Spleen size was negatively associated with nematode load in subadult females and in adult males. These two age classes are potentially the most nutritionally stressed, as subadult hinds are still growing and often engaging in rearing their first calf, and adult stags were sampled just after the rut, which is recognized as a substantial energy drain in this age-sex class, as they compete to hold females during the mating season. Body condition related negatively to parasite count only in adult males. In the context of red deer life history, these findings suggest that spleen size is dependent on body condition and that it could be affected by variation in resource partitioning among immune defense, growth, and reproductive effort in red deer. For the first time in a wild mammal, the spleen mass is shown to be positively related to body condition and negatively related to parasite infection. We conclude that elucidating whether spleen mass reflects immune defense investment or a measure of general body condition should contribute to understanding topical issues in mammal ecology.

Body-size stigmatization by preschool girls: in a doll's world, it is good to be "Barbie".

PubMed

Worobey, John; Worobey, Harriet S

2014-03-01

A number of studies have measured body size stigmatization, that is, the assigning of negative characteristics to individuals who are considered fat, in samples of children as young as preschool-age. The results of such studies are fairly consistent, but may be criticized for the abstract nature of the line drawings typically used as test stimuli. In the present study the utility of using toy dolls to gauge young girls' views toward different body shapes was assessed. Forty girls ages 3½-5½ were asked to assign various traits to one of three dolls (thin, average, and fat). As with previous work, responses fell out in a stereotypical pattern, with the positive characteristics attributed most often to the thin or average doll and all of the negative characteristics most often to the fat doll. The strengths and weaknesses of this doll paradigm in studies of body-size stigmatization by young children are discussed. Copyright © 2014. Published by Elsevier Ltd.

A Model Based Approach to Sample Size Estimation in Recent Onset Type 1 Diabetes

PubMed Central

Bundy, Brian; Krischer, Jeffrey P.

2016-01-01

The area under the curve C-peptide following a 2-hour mixed meal tolerance test from 481 individuals enrolled on 5 prior TrialNet studies of recent onset type 1 diabetes from baseline to 12 months after enrollment were modelled to produce estimates of its rate of loss and variance. Age at diagnosis and baseline C-peptide were found to be significant predictors and adjusting for these in an ANCOVA resulted in estimates with lower variance. Using these results as planning parameters for new studies results in a nearly 50% reduction in the target sample size. The modelling also produces an expected C-peptide that can be used in Observed vs. Expected calculations to estimate the presumption of benefit in ongoing trials. PMID:26991448

Cosmic-Ray-Exposure Ages of Diogenites and the Collisional History of the HED Parent Body or Bodies

NASA Technical Reports Server (NTRS)

Welten, K. C.; Lindner, L.; vanderBorg, K.; Loeken, T.; Scherer, P.; Schultz, L.

1996-01-01

Cosmic-ray-exposure ages of meteorites provide information on the collisional history of their parent bodies and the delivery mechanism of meteorites to Earth. The exposure-age distributions of ordinary chondrites show distinct patterns for H, L, and LL types, consistent with their origin on different parent bodies. The exposure-age distributions of howardites, eucrites. and diogenites (HEDS) show a common pattern with major peaks at 22 Ma and 38 Ma This provides additional evidence for a common origin of the HED meteorites, possibly 4 Vesta, although orbital dynamics calculations showed that the delivery of meteorites from Vesta to Earth is difficult. However, the discovery of several kilometer-sized Vesta-like asteroids in the region between Vesta and the 3:1 resonance suggested that these seem more likely parent bodies of the HEDs than Vesta itself. This implies that the exposure-age clusters may represent samples of several parent bodies. Therefore, the near-absence of diogenites with ages <20 Ma might be of interest for the composition of these kilometer-sized fragments of Vesta. Here we present cosmic-ray-exposure ages of 20 diogenites, including 9 new meteorites. In addition, we calculate the probability for each peak to occur by chance, assuming a constant production rate of HED fragments.

Effects of aging on sleep structure throughout adulthood: a population-based study.

PubMed

Moraes, Walter; Piovezan, Ronaldo; Poyares, Dalva; Bittencourt, Lia Rita; Santos-Silva, Rogerio; Tufik, Sergio

2014-04-01

Although many studies have shown the evolution of sleep parameters across the lifespan, not many have included a representative sample of the general population. The objective of this study was to describe age-related changes in sleep structure, sleep respiratory parameters and periodic limb movements of the adult population of São Paulo. We selected a representative sample of the city of São Paulo, Brazil that included both genders and an age range of 20-80 years. Pregnant and lactating women, people with physical or mental impairments that prevent self-care and people who work every night were not included. This sample included 1024 individuals who were submitted to polysomnography and structured interviews. We subdivided our sample into five-year age groups. One-way analysis of variance was used to compare age groups. Pearson product-moment was used to evaluate correlation between age and sleep parameters. Total sleep time, sleep efficiency, percentage of rapid eye movement (REM) sleep and slow wave sleep showed a significant age-related decrease (P<0.05). WASO (night-time spent awake after sleep onset), arousal index, sleep latency, REM sleep latency, and the percentage of stages 1 and 2 showed a significant increase (P<0.05). Furthermore, apnea-hypopnea index increased and oxygen saturation decreased with age. The reduction in the percentage of REM sleep significantly correlated with age in women, whereas the reduction in the percentage of slow wave sleep correlated with age in men. The periodic limb movement (PLM) index increased with age in men and women. Sleep structure and duration underwent significant alterations throughout the aging process in the general population. There was an important correlation between age, sleep respiratory parameters and PLM index. In addition, men and women showed similar trends but with different effect sizes. Copyright © 2014 Elsevier B.V. All rights reserved.

Soil data from Picea mariana stands near delta junction, Alaska of different ages and soil drainage type

USGS Publications Warehouse

Manies, Kristen L.; Harden, Jennifer W.; Silva, Steven R.; Briggs, Paul H.; Schmid, Brian M.

2004-01-01

The U.S. Geological Survey project Fate of Carbon in Alaskan Landscapes (FOCAL) is studying the effect of fire and soil drainage on soil carbon storage in the boreal forest. This project has selected several sites to study within central Alaska of varying ages (time since fire) and soil drainage types. This report describes the location of these sampling sites, as well as the procedures used to describe, sample, and analyze the soils. This report also contains data tables with this information, including, but not limited to field descriptions, bulk density, particle size distribution, moisture content, carbon (C) concentration, nitrogen (N) concentration, isotopic data for C, and major, minor and trace elemental concentration.

Updating histological data on crown initiation and crown completion ages in southern Africans.

PubMed

Reid, Donald J; Guatelli-Steinberg, Debbie

2017-04-01

To update histological data on crown initiation and completion ages in southern Africans. To evaluate implications of these data for studies that: (a) rely on these data to time linear enamel hypoplasias (LEHs), or, (b) use these data for comparison to fossil hominins. Initiation ages were calculated on 67 histological sections from southern Africans, with sample sizes ranging from one to 11 per tooth type. Crown completion ages for southern Africans were calculated in two ways. First, actual derived initiation ages were added to crown formation times for each histological section to obtain direct information on the crown completion ages of individuals. Second, average initiation ages from this study were added to average crown formation times of southern Africans from the Reid and coworkers previous studies that were based on larger samples. For earlier-initiating tooth types (all anterior teeth and first molars), there is little difference in ages of initiation and crown completion between this and previous studies. Differences increase as a function of initiation age, such that the greatest differences between this and previous studies for both initiation and crown completion ages are for the second and third molars. This study documents variation in initiation ages, particularly for later-initiating tooth types. It upholds the use of previously published histological aging charts for LEHs on anterior teeth. However, this study finds that ages of crown initiation and completion in second and third molars for this southern African sample are earlier than previously estimated. These earlier ages reduce differences between modern humans and fossil hominins for these developmental events in second and third molars. © 2017 Wiley Periodicals, Inc.

Genome flux and stasis in a five millennium transect of European prehistory

PubMed Central

Gamba, Cristina; Jones, Eppie R.; Teasdale, Matthew D.; McLaughlin, Russell L.; Gonzalez-Fortes, Gloria; Mattiangeli, Valeria; Domboróczki, László; Kővári, Ivett; Pap, Ildikó; Anders, Alexandra; Whittle, Alasdair; Dani, János; Raczky, Pál; Higham, Thomas F. G.; Hofreiter, Michael; Bradley, Daniel G; Pinhasi, Ron

2014-01-01

The Great Hungarian Plain was a crossroads of cultural transformations that have shaped European prehistory. Here we analyse a 5,000-year transect of human genomes, sampled from petrous bones giving consistently excellent endogenous DNA yields, from 13 Hungarian Neolithic, Copper, Bronze and Iron Age burials including two to high (~22 × ) and seven to ~1 × coverage, to investigate the impact of these on Europe’s genetic landscape. These data suggest genomic shifts with the advent of the Neolithic, Bronze and Iron Ages, with interleaved periods of genome stability. The earliest Neolithic context genome shows a European hunter-gatherer genetic signature and a restricted ancestral population size, suggesting direct contact between cultures after the arrival of the first farmers into Europe. The latest, Iron Age, sample reveals an eastern genomic influence concordant with introduced Steppe burial rites. We observe transition towards lighter pigmentation and surprisingly, no Neolithic presence of lactase persistence. PMID:25334030

Genome flux and stasis in a five millennium transect of European prehistory.

PubMed

Gamba, Cristina; Jones, Eppie R; Teasdale, Matthew D; McLaughlin, Russell L; Gonzalez-Fortes, Gloria; Mattiangeli, Valeria; Domboróczki, László; Kővári, Ivett; Pap, Ildikó; Anders, Alexandra; Whittle, Alasdair; Dani, János; Raczky, Pál; Higham, Thomas F G; Hofreiter, Michael; Bradley, Daniel G; Pinhasi, Ron

2014-10-21

The Great Hungarian Plain was a crossroads of cultural transformations that have shaped European prehistory. Here we analyse a 5,000-year transect of human genomes, sampled from petrous bones giving consistently excellent endogenous DNA yields, from 13 Hungarian Neolithic, Copper, Bronze and Iron Age burials including two to high (~22 × ) and seven to ~1 × coverage, to investigate the impact of these on Europe's genetic landscape. These data suggest genomic shifts with the advent of the Neolithic, Bronze and Iron Ages, with interleaved periods of genome stability. The earliest Neolithic context genome shows a European hunter-gatherer genetic signature and a restricted ancestral population size, suggesting direct contact between cultures after the arrival of the first farmers into Europe. The latest, Iron Age, sample reveals an eastern genomic influence concordant with introduced Steppe burial rites. We observe transition towards lighter pigmentation and surprisingly, no Neolithic presence of lactase persistence.

A Modern Analog to the Depositional Age Problem: Zircon and Apatite Fission Track and U-Pb Age Distributions by LA-ICP-MS

NASA Astrophysics Data System (ADS)

Donelick, H. M.; Donelick, M. B.; Donelick, R. A.

2012-12-01

Sand from three river systems in North Idaho (Snake River near Lewiston, Clearwater River near Lewiston and the Salmon River near White Bird) and two regional ash fall events (Mt. Mazama and Mt. St. Helens) were collected for zircon U-Pb detrital age analysis. Up to 120 grains of zircon per sample were ablated using a Resonetics M-50 193 nm ArF Excimer laser ablation (LA) system and the Pb, Th, and U isotopic signals were quantified using an Agilent 7700x quadrupole inductively coupled plasma-mass spectrometer (ICP-MS). Isotopic signals for major, minor, and trace elements, including all REEs, were also monitored. The youngest zircon U-Pb ages from the river samples were approximately 44 Ma; Cenozoic Idaho Batholith and Precambrian Belt Supergroup ages were well represented. Significant common Pb contamination of the Clearwater River sample (e.g., placer native Cu was observed in the sample) precluded detailed analysis of the zircon U-Pb ages but no interpretable ages <44 Ma were observed. Interestingly, not one of the river samples yielded zircon U-Pb ages near 0 Ma, despite all three catchment areas having received significant ash from Mt. St. Helens in 1980, and Mount Mazama 7,700 years ago, and no doubt other events during the Quaternary. Work currently in progress seeks to address bias against near 0 Ma ages in the catchment areas due to: a) small, local ash fall grain sizes and b) overwhelming number of older grains relative to the ash fall grains. Data from Mt. St. Helens ash from several localities near the mountain (Toutle River and Maple Flats, WA) and several far from the mountain (Spokane, WA; Princeton, ID; Kalispell, MT) and Mt. Mazama ash fall deposits near Lewiston, ID and Spokane, WA will be presented to address these possibilities. Additionally, fission track and U-Pb ages from apatites collected from these river and ash fall samples will also be shown to help constrain the problem.

Fine motor skills and interhemispheric transfer in treatment-naive male children with Tourette syndrome.

PubMed

Buse, Judith; August, Julia; Bock, Nathalie; Dörfel, Denise; Rothenberger, Aribert; Roessner, Veit

2012-07-01

This study addressed whether Tourette syndrome is associated with an impairment of fine motor skills or altered interhemispheric transfer. We additionally investigated the association between interhemispheric transfer and size of the corpus callosum. The sample, a subsample of our larger neuroimaging sample, included 27 treatment-naive males with 'pure' Tourette syndrome (age range 10y 2mo-14y 4mo; mean age 11y 10mo, SD 1y 2mo) and 26 matched healthy comparison children (age range 10y 2mo-14y 4mo; mean age 11y 10mo, SD 1y 1mo). A finger tapping task and the Purdue Pegboard were used to assess fine motor skills. Interhemispheric transfer time (ITT) was measured with the Poffenberger paradigm. The neuroanatomical data were derived from our previous neuroimaging study. ITT was negatively correlated with the size of callosal subregion 3 (r=-0.366, p=0.028), indicating that a shorter ITT was associated with a larger corpus callosum. Our findings support the assumption that previously reported impairment of motor skills in Tourette syndrome does not directly result from tics but from other factors such as medication or comorbidities. Following the assumption that callosal subregion 3 in Tourette syndrome grows as a consequence of tic performance over years, our preliminary results suggest that this growth might accelerate interhemispheric transfer in Tourette syndrome. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

Prevalence of any size adenomas and advanced adenomas in 40- to 49-year-old individuals undergoing screening colonoscopy because of a family history of colorectal carcinoma in a first-degree relative.

PubMed

Gupta, Akshay K; Samadder, Jewel; Elliott, Eric; Sethi, Saurabh; Schoenfeld, Philip

2011-07-01

Per current guidelines, patients with a first-degree relative (FDR) with colorectal cancer (CRC) should get screened at least at age 40. Data about the prevalence of adenomas and advanced adenomas (AAs) in these patients are lacking. To examine the prevalence of adenomas and AAs in 40- to 49-year-old individuals undergoing screening colonoscopy for family history of CRC. Retrospective chart review. Asymptomatic patients 40 to 49 years of age undergoing their first screening colonoscopy at the University of Michigan during the period 1999 to 2009 because of an FDR with CRC. Prevalence of adenomas (any size), AAs, and risk factors associated with adenomas. Among 640 study patients, the prevalence of adenomas (any size) was 15.4% and 3.3% for AAs. Adenoma prevalence was lower if the FDR with CRC was younger than 60 years of age versus an FDR with CRC older than 60 years of age (12.4% vs 19%, P = .034). Male sex (odds ratio 2.6; 95% CI, 1.06-4.4) and advancing age (odds ratio 1.16; 95% CI, 1.03-1.31) were associated with adenomas. Limited data on risk factor exposure and insufficient sample size to assess risk factors for AAs. Among 40- to 49-year-old patients undergoing screening colonoscopy because of an FDR with CRC, the prevalence of adenomas and AAs is low. Further research should determine whether these individuals have a higher prevalence of adenomas compared with average-risk individuals. Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Insulin Resistance Is Associated With Smaller Cortical Bone Size in Nondiabetic Men at the Age of Peak Bone Mass.

PubMed

Verroken, Charlotte; Zmierczak, Hans-Georg; Goemaere, Stefan; Kaufman, Jean-Marc; Lapauw, Bruno

2017-06-01

In type 2 diabetes mellitus, fracture risk is increased despite preserved areal bone mineral density. Although this apparent paradox may in part be explained by insulin resistance affecting bone structure and/or material properties, few studies have investigated the association between insulin resistance and bone geometry. We aimed to explore this association in a cohort of nondiabetic men at the age of peak bone mass. Nine hundred ninety-six nondiabetic men aged 25 to 45 years were recruited in a cross-sectional, population-based sibling pair study at a university research center. Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR), with insulin and glucose measured from fasting serum samples. Bone geometry was assessed using peripheral quantitative computed tomography at the distal radius and the radial and tibial shafts. In age-, height-, and weight-adjusted analyses, HOMA-IR was inversely associated with trabecular area at the distal radius and with cortical area, periosteal and endosteal circumference, and polar strength strain index at the radial and tibial shafts (β ≤ -0.13, P < 0.001). These associations remained essentially unchanged after additional adjustment for dual-energy X-ray absorptiometry-derived body composition, bone turnover markers, muscle size or function measurements, or adiponectin, leptin, insulin-like growth factor 1, or sex steroid levels. In this cohort of nondiabetic men at the age of peak bone mass, insulin resistance is inversely associated with trabecular and cortical bone size. These associations persist after adjustment for body composition, muscle size or function, or sex steroid levels, suggesting an independent effect of insulin resistance on bone geometry. Copyright © 2017 Endocrine Society

Age-related differences in muscle fatigue vary by contraction type: a meta-analysis.

PubMed

Avin, Keith G; Law, Laura A Frey

2011-08-01

During senescence, despite the loss of strength (force-generating capability) associated with sarcopenia, muscle endurance may improve for isometric contractions. The purpose of this study was to perform a systematic meta-analysis of young versus older adults, considering likely moderators (ie, contraction type, joint, sex, activity level, and task intensity). A 2-stage systematic review identified potential studies from PubMed, CINAHL, PEDro, EBSCOhost: ERIC, EBSCOhost: Sportdiscus, and The Cochrane Library. Studies reporting fatigue tasks (voluntary activation) performed at a relative intensity in both young (18-45 years of age) and old (≥ 55 years of age) adults who were healthy were considered. Sample size, mean and variance outcome data (ie, fatigue index or endurance time), joint, contraction type, task intensity (percentage of maximum), sex, and activity levels were extracted. Effect sizes were (1) computed for all data points; (2) subgrouped by contraction type, sex, joint or muscle group, intensity, or activity level; and (3) further subgrouped between contraction type and the remaining moderators. Out of 3,457 potential studies, 46 publications (with 78 distinct effect size data points) met all inclusion criteria. A lack of available data limited subgroup analyses (ie, sex, intensity, joint), as did a disproportionate spread of data (most intensities ≥ 50% of maximum voluntary contraction). Overall, older adults were able to sustain relative-intensity tasks significantly longer or with less force decay than younger adults (effect size=0.49). However, this age-related difference was present only for sustained and intermittent isometric contractions, whereas this age-related advantage was lost for dynamic tasks. When controlling for contraction type, the additional modifiers played minor roles. Identifying muscle endurance capabilities in the older adult may provide an avenue to improve functional capabilities, despite a clearly established decrement in peak torque.

Color Stability of Silicone or Acrylic Denture Liners: An in Vitro Investigation

PubMed Central

Ergun, Gulfem; Nagas, Isil Cekic

2007-01-01

Objectives The aim of this study was to compare the color stability of three acrylic based hard liners (Ufi gel hard, Dura-Liner II, Tokuso Rebase) and two silicone based soft liners (Ufi gel permanent, Molloplast B) by using the colorimeter. Methods Sixty disc-shaped samples, with uniform size of 10 mm diameter and 2 mm in thickness were fabricated for each material. Thirty samples were made as control group in distilled water and the remaining thirty samples were weathered in accelerated aging chamber. Color measurements were made before and after distilled water and aging. Data were statistically analyzed using nonparametric Kruskal-Wallis and Mann-Whitney U tests. Results Data showed that there are significant differences among materials in both after distilled water and aging treatments (P<.001). These results indicated that the most discolored liner material was Dura Liner II after aging (ΔE*=16.30) and the least discolored material was Ufi gel permanent after distilled water (ΔE*=0.41). Conclusions Based on the results of this study, silicone based liner materials are considered to be more color stable than acrylic based liner materials. PMID:19212558

Age-related invariance of abilities measured with the Wechsler Adult Intelligence Scale-IV.

PubMed

Sudarshan, Navaneetham J; Bowden, Stephen C; Saklofske, Donald H; Weiss, Lawrence G

2016-11-01

Assessment of measurement invariance across populations is essential for meaningful comparison of test scores, and is especially relevant where repeated measurements are required for educational assessment or clinical diagnosis. Establishing measurement invariance legitimizes the assumption that test scores reflect the same psychological trait in different populations or across different occasions. Examination of Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) U.S. standardization samples revealed that a first-order 5-factor measurement model was best fitting across 9 age groups from 16 years to 69 years. Strong metric invariance was found for 3 of 5 factors and partial intercept invariance for the remaining 2. Pairwise comparisons of adjacent age groups supported the inference that cognitive-trait group differences are manifested by group differences in the test scores. In educational and clinical settings these findings provide theoretical and empirical support to interpret changes in the index or subtest scores as reflecting changes in the corresponding cognitive abilities. Further, where clinically relevant, the subtest score composites can be used to compare changes in respective cognitive abilities. The model was supported in the Canadian standardization data with pooled age groups but the sample sizes were not adequate for detailed examination of separate age groups in the Canadian sample. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Cross-sectional study of height and weight in the population of Andalusia from age 3 to adulthood

PubMed Central

López-Siguero, Juan Pedro; García, Juan Manuel Fernández; Castillo, Juan de Dios Luna; Molina, Jose Antonio Moreno; Cosano, Carlos Ruiz; Ortiz, Antonio Jurado

2008-01-01

Background and objectives In Andalusia there were no studies including a representative sample of children and adolescent population assessing growth and weight increase. Our objectives were to develop reference standards for weight, height and BMI for the Andalusian pediatric population, from 3 to 18 years of age for both genders, and to identify the final adult height in Andalusia. Subjects and methods Two samples were collected. The first included individuals from 3 to 18 years of age (3592 girls and 3605 boys). They were stratified according type of study center, size of population of origin, age (32 categories of 0.5 years) and gender, using cluster sampling. Subjects from >18 to 23 years of age (947 women and 921 men) were sampled in 6 non-university educational centers and several university centers in Granada. Exclusion criteria included sons of non-Spanish mother or father, and individuals with chronic conditions and/or therapies affecting growth. Two trained fellows collected the data through February to December 2004, for the first sample, and through January to May 2005, for the second. Reference curves were adjusted using Cole's LMS method, and the quality of the adjustment was assessed using the tests proposed by Royston. In addition, a sensitivity analysis was applied to the final models obtained. Results Data for 9065 cases (4539 women and 4526 men) were obtained; 79.39% (n = 7197) in the up to 18 years of age group. In the first sampling only 0.07% (3 girls and 2 boys) refused to participate in the study. In addition, 327 students (4.5%) were absent when sampling was done. We present mean and standard deviation fort height, weight and BMI at 0.5 years intervals, from 3 to 23 years of age, for both genders. After adjustment with the different models, percentiles for height, weight (percentiles 3, 5, 10, 25, 50, 75, 90, 95, and 97) and BMI (percentiles 3, 5, 50, 85, 95, and 97) are presented for both genders. Conclusion This is the first study in Andalusia with a representative sample from the child-juvenile population to investigate weight, height and BMI in subjects from 3 to 23 years of age. The great variability observed in the values from sample of 18 to 23 years of age individuals, ensures the inclusion of extreme values, although random sampling was not used. There still is a lack of standard reference values for the Andalusian population younger done 3 years of age. PMID:18673524

The Laboratory Study of Shear Strength of the Overconsolidated and Quasi - Overconsolidated Fine - Grained Soil

NASA Astrophysics Data System (ADS)

Strozyk, Joanna

2017-12-01

The paper presents results of laboratory shear strength test conducted on fine-grained soil samples with different grain size distribution and with different geological age and stress history. The Triaxial Isotopic Consolidation Undrained Tests (TXCIU) were performed under different consolidation stress in normal and overconsolidadion stress state on the samples with natural structure. Soil samples were selected from soil series of different age and geological origins: overconsolidated sensu stricto Miopliocene silty clay (siCl) and quasi overconsolidated Pleistocene clayey silt (clSi). Paper pointed out that overconsolidated sensu stricto and quasi overconsolidated fine-grained soil in same stress and environmental condition could show almost similar behaviour, and in other condition could behave significantly different. The correct evaluation of geotechnical parameters, the possibility of predicting their time-correct ability is only possible with appropriately recognized geological past and past processes that accompanied the soil formation.

Phenotypic characterization of individuals with 30-40 CAG repeats in the Huntington disease (HD) gene reveals HD cases with 36 repeats and apparently normal elderly individuals with 36-39 repeats

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

Rubinsztein, D.C.; Leggo, J.; Whittaker, J.L.

1996-07-01

Abnormal CAG expansions in the IT-15 gene are associated with Huntington disease (HD). In the diagnostic setting it is necessary to define the limits of the CAG size ranges on normal and HD-associated chromosomes. Most large analyses that defined the limits of the normal and pathological size ranges employed PCR assays, which included the CAG repeats and a CCG repeat tract that was thought to be invariant. Many of these experiments found an overlap between the normal and disease size ranges. Subsequent findings that the CCG repeats vary by 9 trinucleotide lengths suggested that the limits of the normal andmore » disease size ranges should be reevaluated with assays that exclude the CCG polymorphism. Since patients with between 30 and 40 repeats are rare, a consortium was assembled to collect such individuals. All 178 samples were reanalyzed in Cambridge by using assays specific for the CAG repeats. We have optimized methods for reliable sizing of CAG repeats and show cases that demonstrate the dangers of using PCR assays that include both the CAG and CCG polymorphisms. Seven HD patients had 36 repeats, which confirms that this allele is associated with disease. Individuals without apparent symptoms or signs of HD were found at 36 repeats (aged 74, 78, 79, and 87 years), 37 repeats (aged 69 years), 38 repeats (aged 69 and 90 years), and 39 repeats (aged 67, 90, and 95 years). The detailed case histories of an exceptional case from this series will be presented: a 95-year-old man with 39 repeats who did not have classical features of HD. The apparently healthy survival into old age of some individuals with 36-39 repeats suggests that the HD mutation may not always be fully penetrant. 26 refs., 3 figs., 1 tab.« less

Goldeye, Hiodon alosoides, in Lake Oahe: abundance, age, growth, maturity, food, and the fishery, 1963-69

USGS Publications Warehouse

Miller, Grant L.; Nelson, William R.

1974-01-01

Reproductive success was relatively consistent, and adequate to maintain species abundance at a nearly constant level, during 1963-69. Both abundance and growth in length increased from the lower to the upper portion of the reservoir. In most characteristics -- growth in length, length-weight relation, age at maturity, and food -- goldeye in Lake Oahe were similar to those from other Missouri River impoundments. Experimental gill nets samples all lengths (range 80-460 mm; median, 320 mm) of goldeye, bottom trawls sampled mostly small fish, (median, 215 mm) and trap nets large ones (median, 345 mm). Commercial gill nets were highly size selective (median, 375 mm); fish of ages IV-VII made up 90% of the catch. Survival rates were 57 to 52% for ages II-X. Estimated survival rates for ages V-IX declined from 44 to 35% after the inception of the commercial fishery in 1966. The peak commercial catch was 151,432 kg (1.2 kg/hectare) in 1969. Unless recruitment declines, the population can support a fishery of that magnitude.

Emergent literacy profiles of preschool-age children with specific language impairment.

PubMed

Cabell, Sonia Q; Lomax, Richard G; Justice, Laura M; Breit-Smith, Allison; Skibbe, Lori E; McGinty, Anita S

2010-12-01

The primary aim of the present study was to explore the heterogeneity of emergent literacy skills among preschool-age children with specific language impairment (SLI) through examination of profiles of performance. Fifty-nine children with SLI were assessed on a battery of emergent literacy skills (i.e., alphabet knowledge, print concepts, emergent writing, rhyme awareness) and oral language skills (i.e., receptive/expressive vocabulary and grammar). Cluster analysis techniques identified three emergent literacy profiles: (1) Highest Emergent Literacy, Strength in Alphabet Knowledge; (2) Average Emergent Literacy, Strength in Print Concepts; and (3) Lowest Emergent Literacy across Skills. After taking into account the contribution of child age, receptive and expressive language skills made a small contribution to the prediction of profile membership. The present findings, which may be characterized as exploratory given the relatively modest sample size, suggest that preschool-age children with SLI display substantial individual differences with regard to their emergent literacy skills and that these differences cannot be fully determined by children's age or oral language performance. Replication of the present findings with a larger sample of children is needed.

Typography for Children May Be Inappropriately Designed

ERIC Educational Resources Information Center

Wilkins, Arnold; Cleave, Roanna; Grayson, Nicola; Wilson, Louise

2009-01-01

We present four studies indicating that the size and design of the typeface in textual material for children aged 7-9 may impair speed of reading and comprehension, and measurement of reading attainment. The first study compared the speed with which sample sentences were comprehended. The sentences were printed in Arial font with an x-height of…

What can child silhouette data tell us? Exploring links to parenting, food and activity behaviors, and maternal concerns

USDA-ARS?s Scientific Manuscript database

Purpose: A study of resiliency to overweight explored how child silhouettes (maternal perception of child’s body size) related to child BMI, maternal concerns, parenting styles and practices. Methods: In a diverse, multi-state sample, 175 low-income mother-child (ages 3-11) dyads were assessed for...

Attitudes towards smoking restrictions and tobacco advertisement bans in Georgia.

PubMed

Bakhturidze, George D; Mittelmark, Maurice B; Aarø, Leif E; Peikrishvili, Nana T

2013-11-25

This study aims to provide data on a public level of support for restricting smoking in public places and banning tobacco advertisements. A nationally representative multistage sampling design, with sampling strata defined by region (sampling quotas proportional to size) and substrata defined by urban/rural and mountainous/lowland settlement, within which census enumeration districts were randomly sampled, within which households were randomly sampled, within which a randomly selected respondent was interviewed. The country of Georgia, population 4.7 million, located in the Caucasus region of Eurasia. One household member aged between 13 and 70 was selected as interviewee. In households with more than one age-eligible person, selection was carried out at random. Of 1588 persons selected, 14 refused to participate and interviews were conducted with 915 women and 659 men. Respondents were interviewed about their level of agreement with eight possible smoking restrictions/bans, used to calculate a single dichotomous (agree/do not agree) opinion indicator. The level of agreement with restrictions was analysed in bivariate and multivariate analyses by age, gender, education, income and tobacco use status. Overall, 84.9% of respondents indicated support for smoking restrictions and tobacco advertisement bans. In all demographic segments, including tobacco users, the majority of respondents indicated agreement with restrictions, ranging from a low of 51% in the 13-25 age group to a high of 98% in the 56-70 age group. Logistic regression with all demographic variables entered showed that agreement with restrictions was higher with age, and was significantly higher among never smokers as compared to daily smokers. Georgian public opinion is normatively supportive of more stringent tobacco-control measures in the form of smoking restrictions and tobacco advertisement bans.

Monitoring the effective population size of a brown bear (Ursus arctos) population using new single-sample approaches.

PubMed

Skrbinšek, Tomaž; Jelenčič, Maja; Waits, Lisette; Kos, Ivan; Jerina, Klemen; Trontelj, Peter

2012-02-01

The effective population size (N(e) ) could be the ideal parameter for monitoring populations of conservation concern as it conveniently summarizes both the evolutionary potential of the population and its sensitivity to genetic stochasticity. However, tracing its change through time is difficult in natural populations. We applied four new methods for estimating N(e) from a single sample of genotypes to trace temporal change in N(e) for bears in the Northern Dinaric Mountains. We genotyped 510 bears using 20 microsatellite loci and determined their age. The samples were organized into cohorts with regard to the year when the animals were born and yearly samples with age categories for every year when they were alive. We used the Estimator by Parentage Assignment (EPA) to directly estimate both N(e) and generation interval for each yearly sample. For cohorts, we estimated the effective number of breeders (N(b) ) using linkage disequilibrium, sibship assignment and approximate Bayesian computation methods and extrapolated these estimates to N(e) using the generation interval. The N(e) estimate by EPA is 276 (183-350 95% CI), meeting the inbreeding-avoidance criterion of N(e) > 50 but short of the long-term minimum viable population goal of N(e) > 500. The results obtained by the other methods are highly consistent with this result, and all indicate a rapid increase in N(e) probably in the late 1990s and early 2000s. The new single-sample approaches to the estimation of N(e) provide efficient means for including N(e) in monitoring frameworks and will be of great importance for future management and conservation. © 2012 Blackwell Publishing Ltd.

A longitudinal study of the relationships between the Big Five personality traits and body size perception.

PubMed

Hartmann, Christina; Siegrist, Michael

2015-06-01

The present study investigated the longitudinal development of body size perception in relation to different personality traits. A sample of Swiss adults (N=2905, 47% men), randomly selected from the telephone book, completed a questionnaire on two consecutive years (2012, 2013). Body size perception was assessed with the Contour Drawing Rating Scale and personality traits were assessed with a short version of the Big Five Inventory. Longitudinal analysis of change indicated that men and women scoring higher on conscientiousness perceived themselves as thinner one year later. In contrast, women scoring higher on neuroticism perceived their body size as larger one year later. No significant effect was observed for men scoring higher on neuroticism. These results were independent of weight changes, body mass index, age, and education. Our findings suggest that personality traits contribute to body size perception among adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

Secular trends are associated with the demographic and epidemiologic transitions in an indigenous community in Oaxaca, Southern Mexico.

PubMed

Malina, Robert M; Little, Bertis B; Peña Reyes, Maria Eugenia

2018-01-01

To test the hypothesis that secular changes in body size and age at menarche are related to the demographic and epidemiologic transitions in an indigenous community in Oaxaca, southern Mexico. Data were derived from surveys of a Zapotec-speaking community conducted between 1968 and 2000. Segmented linear regressions of height, weight, BMI and recalled age at menarche on year of birth in cohorts of adults born before and after the demographic transition were used to evaluate secular changes. Corresponding comparisons of body size (MANCOVA controlling for age) and age at menarche (status quo, probit analysis) were done for samples of children and adolescents born before and after the epidemiological transition. Height and weight increased in adults born after the demographic transition (mid-1950s), and especially in children and adolescents born after the epidemiological transition (mid-1980s). Age at menarche also decreased significantly in women born after the demographic transition, but at a more rapid estimated rate in adolescents born after the epidemiological transition. Secular gains in body weight were proportional to those for height among children and adolescents, but adults, males more so than females, gained proportionally more weight. The secular trend in height in adults of both sexes was associated with the decade of the demographic transition in the mid-1950s. Significant secular gains in size attained and age at menarche occurred in children and youth born after the epidemiologic transition which likely reflected improved health and nutritional conditions since the mid-1980s. © 2017 Wiley Periodicals, Inc.

Immunization coverage and predictive factors for complete and age-appropriate vaccination among preschoolers in Athens, Greece: a cross--sectional study.

PubMed

Pavlopoulou, Ioanna D; Michail, Koralia A; Samoli, Evangelia; Tsiftis, George; Tsoumakas, Konstantinos

2013-10-02

In Greece, several new childhood vaccines were introduced recently but were reimbursed gradually and at different time points. The aim of this study was to assess immunization coverage and identify factors influencing complete and age-appropriate vaccination among children attending public nurseries in the municipal district of Athens. A cross-sectional study, using stratified sampling was performed. Immunization history was obtained from vaccination booklets. Demographic and socioeconomic data were obtained from school registries and telephone interviews. Vaccination rates were estimated by sample weighted proportions while associations between complete and age-appropriate immunization and potential determinants by logistic regression analysis. A total of 731 children (mean age: 46, median: 48, range: 10-65 months) were included. Overall immunization coverage with traditional vaccines (DTP, polio, Hib, HBV, 1st dose MMR) was satisfactory, exceeding 90%, but the administration of booster doses was delayed (range: 33.7- 97.4%, at 60 months of age). Complete vaccination rates were lower for new vaccines (Men C, PCV7, varicella, hepatitis A), ranging between 61-92%. In addition, a significant delay in timely administration of Men C, PCV7, as well as HBV was noted (22.9%, 16.0% and 27.7% at 12 months of age, respectively). Child's age was strongly associated with incomplete vaccination with all vaccines (p< 0.001), while as immigrant status was a predictor of incomplete (p=0.034) and delayed vaccination (p<0.001) with traditional vaccines. Increasing household size and higher maternal education were negatively associated with the receipt of all and newly licensed vaccines, respectively (p=0.035). Our findings highlight the need to monitor uptake of new vaccines and improve age- appropriate administration of booster doses as well as early vaccination against hepatitis B. Immigrant status, increased household size and high maternal education may warrant targeted intervention.

Immunization coverage and predictive factors for complete and age-appropriate vaccination among preschoolers in Athens, Greece: a cross- sectional study

PubMed Central

2013-01-01

Background In Greece, several new childhood vaccines were introduced recently but were reimbursed gradually and at different time points. The aim of this study was to assess immunization coverage and identify factors influencing complete and age-appropriate vaccination among children attending public nurseries in the municipal district of Athens. Methods A cross-sectional study, using stratified sampling was performed. Immunization history was obtained from vaccination booklets. Demographic and socioeconomic data were obtained from school registries and telephone interviews. Vaccination rates were estimated by sample weighted proportions while associations between complete and age-appropriate immunization and potential determinants by logistic regression analysis. Results A total of 731 children (mean age: 46, median: 48, range: 10–65 months) were included. Overall immunization coverage with traditional vaccines (DTP, polio, Hib, HBV, 1st dose MMR) was satisfactory, exceeding 90%, but the administration of booster doses was delayed (range: 33.7- 97.4%, at 60 months of age). Complete vaccination rates were lower for new vaccines (Men C, PCV7, varicella, hepatitis A), ranging between 61-92%. In addition, a significant delay in timely administration of Men C, PCV7, as well as HBV was noted (22.9%, 16.0% and 27.7% at 12 months of age, respectively). Child’s age was strongly associated with incomplete vaccination with all vaccines (p< 0.001), while as immigrant status was a predictor of incomplete (p=0.034) and delayed vaccination (p<0.001) with traditional vaccines. Increasing household size and higher maternal education were negatively associated with the receipt of all and newly licensed vaccines, respectively (p=0.035). Conclusions Our findings highlight the need to monitor uptake of new vaccines and improve age- appropriate administration of booster doses as well as early vaccination against hepatitis B. Immigrant status, increased household size and high maternal education may warrant targeted intervention. PMID:24083352

Study of Aging-Induced Degradation of Fracture Resistance of Alloy 617 Toward High-Temperature Applications

NASA Astrophysics Data System (ADS)

Singh, Aditya Narayan; Moitra, A.; Bhaskar, Pragna; Sasikala, G.; Dasgupta, Arup; Bhaduri, A. K.

2017-07-01

For the Alloy 617, the effect of aging on the fracture energy degradation has been investigated after aging for different time periods at 1023 K (750 °C). A sharp reduction in impact energy (by 55 pct vis-à-vis the as-received material) after 1000 hours of aging, as evaluated from room-temperature Charpy impact tests, has been observed. Further aging up to 10,000 hours has led to a degradation of fracture energy up to 78 pct. Fractographic examinations using scanning electron microscopy (SEM) have revealed a change in fracture mode from fibrous-ductile for the un-aged material to intergranular mode for the aged one. The extent of intergranular fracture increases with the increasing aging time, indicating a tendency of the material to undergo grain boundary embrittlement over long-term aging. Analysis of the transmission electron microscopy (TEM) micrographs along with selected area diffraction (SAD) patterns for the samples aged at 10,000 hours revealed finely dispersed γ' precipitates of size 30 to 40 nm, rich in Al and Ti, along with extensive precipitation of M23C6 at the grain boundaries. In addition, the presence of Ni3Si of size in the range of 110 to 120 nm also has been noticed. The extensive precipitation of M23C6 at the grain boundaries have been considered as a major reason for aging-induced embrittlement of this material.

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms.

PubMed

Deshaies, Eric M; Villwock, Mark R; Singla, Amit; Toshkezi, Gentian; Padalino, David J

2015-08-11

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients ≤55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged ≤55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges: $52,779 vs. $101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Loss of genetic connectivity and diversity in urban microreserves in a southern California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus n. sp. "santa monica")

USGS Publications Warehouse

Vandergast, A.G.; Lewallen, E.A.; Deas, J.; Bohonak, A.J.; Weissman, D.B.; Fisher, R.N.

2009-01-01

Microreserves may be useful in protecting native arthropod diversity in urbanized landscapes. However, species that do not disperse through the urban matrix may eventually be lost from these fragments. Population extinctions may be precipitated by an increase in genetic differentiation among fragments and loss of genetic diversity within fragments, and these effects should become stronger with time. We analyzed population genetic structure in the dispersal limited Jerusalem cricket Stenopelmatus n. sp. "santa monica" in the Santa Monica Mountains and Simi Hills north of Los Angeles, California (CA), to determine the impacts of fragmentation over the past 70 years. MtDNA divergence was greater among urban fragments than within contiguous habitat and was positively correlated with fragment age. MtDNA genetic diversity within fragments increased with fragment size and decreased with fragment age. Genetic divergence across 38 anonymous nuclear Inter-Simple Sequence Repeat (ISSR) loci was influenced by the presence of major highways and highway age, but there was no effect of additional urban fragmentation. ISSR diversity was not correlated with fragment size or age. Differing results between markers may be due to male-biased dispersal, or different effective population sizes, sorting rates, or mutation rates among sampled genes. Results suggest that genetic connectivity among populations has been disrupted by highways and urban development, prior to declines in local population sizes. We emphasize that genetic connectivity can rapidly erode in fragmented landscapes and that flightless arthropods can serve as sensitive indicators for these effects. ?? Springer Science+Business Media B.V. 2008.

Renal function and size at young adult age after intrauterine growth restriction and very premature birth.

PubMed

Keijzer-Veen, Mandy G; Kleinveld, Hilda A; Lequin, Maarten H; Dekker, Friedo W; Nauta, Jeroen; de Rijke, Yolanda B; van der Heijden, Bert J

2007-10-01

Premature birth and intrauterine growth restriction may increase the risk of developing renal disease at adult age. Renal function may already be impaired at young adult age. Cross-sectional study. Very premature individuals (gestational age < 32 weeks) recruited from Project on Premature and Small for Gestational Age Infants and full-term-born controls (37 to 42 weeks) recruited from a children's hospital in Rotterdam, The Netherlands. All individuals were 20 years of age at the time of study. Gestational age and birth weight: premature and small for gestational age (SGA; n = 23), premature and appropriate for gestational age (n = 29), and controls (n = 30). Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and filtration fraction before and after renal stimulation with low-dose dopamine infusion and oral amino-acid intake. Urine albumin and renal ultrasound. Height, weight, kidney length and volume, GFR, and ERPF were significantly lower in the SGA group than in controls. After adjustment for body surface area, GFR did not differ significantly among groups. Mean ERPF was 71 mL/min/1.73 m(2) (95% confidence interval [CI], 3 to 139) less, but filtration fraction was only 1.3% (95% CI, -0.3 to 3.0) greater, in the SGA group than controls. Renal stimulation significantly increased GFR and ERPF and decreased filtration fraction in all groups. After renal stimulation, ERPF was 130 mL/min/1.73 m(2) (95% CI, 21 to 238) greater in the SGA group than controls, but GFR and filtration fraction did not differ significantly among groups. Microalbuminuria was present in 2 patients (8.7%) in the SGA group, but none in the appropriate-for-gestational-age group or controls. Renal function correlated with renal size. Small sample size. Our findings do not fully support the hypothesis that preterm birth in combination with intrauterine growth restriction contributes to renal function alterations at young adult age. Larger studies are needed to evaluate this hypothesis.

Microbial utilization of nitrogen in cold core eddies: size does matter

NASA Astrophysics Data System (ADS)

McInnes, A.; Messer, L. F.; Laiolo, L.; Laverock, B.; Laczka, O.; Brown, M. V.; Seymour, J.; Doblin, M.

2016-02-01

As the base of the marine food web, and the first step in the biological carbon pump, understanding changes in microbial community composition is essential for predicting changes in the marine nitrogen (N) cycle. Climate change projections suggest that oligotrophic waters will become more stratified with a concomitant shift in microbial community composition based on changes in N supply. In regions of strong boundary currents, eddies could reduce this limitation through nutrient uplift and other forms of eddy mixing. Understanding the preference for different forms of N by microbes is essential for understanding and predicting shifts in the microbial community. This study aims to understand the utilization of different N species within different microbial size fractions as well as understand the preferred source of N to these groups across varying mesoscale and sub-mesoscale features in the East Australian Current (EAC). In June 2015 we sampled microbial communities from three depths (surface, chlorophyll-a maximum and below the mixed layer), in three mesoscale and sub-mesoscale eddy features, as well as two end-point water masses (coastal and oligotrophic EAC water). Particulate matter was analysed for stable C and N isotopes, and seawater incubations with trace amounts of 15NO3, 15NH4, 15N2, 15Urea and 13C were undertaken. All samples were size fractionated into 0.3-2.0 µm, 2.0-10 µm, and >10 µm size classes, encompassing the majority of microbes in these waters. Microbial community composition was also assessed (pigments, flow cytometry, DNA), as well as physical and chemical parameters, to better understand the drivers of carbon fixation and nitrogen utilization across a diversity of water masses and microbial size classes. We observed that small, young features have a greater abundance of larger size classes. We therefore predict that these microbes will preferentially draw down the recently pulsed NO3. Ultimately, the size and age of a feature will determine the N compound utilization and microbial community composition and as the feature grows in size and age a community succession will lead to differential more diverse N compound utilization.

Predicting crappie recruitment in Ohio reservoirs with spawning stock size, larval density, and chlorophyll concentrations

USGS Publications Warehouse

Bunnell, David B.; Hale, R. Scott; Vanni, Michael J.; Stein, Roy A.

2006-01-01

Stock-recruit models typically use only spawning stock size as a predictor of recruitment to a fishery. In this paper, however, we used spawning stock size as well as larval density and key environmental variables to predict recruitment of white crappies Pomoxis annularis and black crappies P. nigromaculatus, a genus notorious for variable recruitment. We sampled adults and recruits from 11 Ohio reservoirs and larvae from 9 reservoirs during 1998-2001. We sampled chlorophyll as an index of reservoir productivity and obtained daily estimates of water elevation to determine the impact of hydrology on recruitment. Akaike's information criterion (AIC) revealed that Ricker and Beverton-Holt stock-recruit models that included chlorophyll best explained the variation in larval density and age-2 recruits. Specifically, spawning stock catch per effort (CPE) and chlorophyll explained 63-64% of the variation in larval density. In turn, larval density and chlorophyll explained 43-49% of the variation in age-2 recruit CPE. Finally, spawning stock CPE and chlorophyll were the best predictors of recruit CPE (i.e., 74-86%). Although larval density and recruitment increased with chlorophyll, neither was related to seasonal water elevation. Also, the AIC generally did not distinguish between Ricker and Beverton-Holt models. From these relationships, we concluded that crappie recruitment can be limited by spawning stock CPE and larval production when spawning stock sizes are low (i.e., CPE , 5 crappies/net-night). At higher levels of spawning stock sizes, spawning stock CPE and recruitment were less clearly related. To predict recruitment in Ohio reservoirs, managers should assess spawning stock CPE with trap nets and estimate chlorophyll concentrations. To increase crappie recruitment in reservoirs where recruitment is consistently poor, managers should use regulations to increase spawning stock size, which, in turn, should increase larval production and recruits to the fishery.

Ventricular mass in relation to body size, composition, and skeletal age in adolescent athletes.

PubMed

Valente-Dos-Santos, João; Coelho-e-Silva, Manuel J; Vaz, Vasco; Figueiredo, António J; Castanheira, Joaquim; Leite, Neiva; Sherar, Lauren B; Baxter-Jones, Adam; Elferink-Gemser, Marije T; Malina, Robert M

2013-07-01

To examine the contribution of chronological age (CA), skeletal age (SA), stature, sitting stature, fat-free mass (FFM), and fat mass (FM) to interindividual variability in left ventricular mass (LVM) in male adolescent roller hockey players using allometric models. Cross sectional. Training and competitive sport during adolescence. Seventy-three Portuguese male roller hockey players aged 14.5 to 16.5 years. Stature, sitting stature, body mass, estimated FM and FFM, and SA assessed by the Fels method. Allometric modeling of LVM assessed in accordance with recommendations of the American Society of Echocardiography. Hockey players (CA: 15.4 ± 0.6 years; SA: 16.4 ± 1.5 years) showed an eccentric remodeling of LV structure within the reference range (ie, 0.24-0.42), a dilated LV chamber, but no LVM increase. Exponents for body size descriptors were 2.69 for stature (R(2) = 27%; P < 0.001), 2.49 for sitting stature (R(2) = 37%; P < 0.001), 0.76 for FFM (R(2) = 31%; P < 0.001), and 0.22 for FM (R(2) = 26%; P < 0.001). The combination of size descriptors with CA and SA increased the explained variance in LVM slightly (26%-45%). When stature and FM are used for indexing LVM in a sample of adolescent athletes, biological maturity status should also be considered.

Evaluation of effect of laser etching on shear bond strength between maxillofacial silicone and acrylic resin subjected to accelerated aging process.

PubMed

Rhea, Antonette; Ahila, S C; Kumar, B Muthu

2017-01-01

Maxillofacial prosthesis are supported by implants, require a retentive matrix to retain the suprastructure. The retentive matrix is made up of acrylic resin to which the silicone prostheses are anchored by micro-mechanical bond. The delamination of silicone away from the retentive matrix is a persisting problem in implant-supported maxillofacial prosthesis. This study aimed to evaluate the effect of laser etching on the shear bond strength (BS) between acrylic resin and maxillofacial silicone, after 24 h of fabrication and after 200 h of accelerated aging. The samples were prepared according to ISO/TR 11405:1994 in maxillofacial silicone and polymethyl methacrylate resin. The untreated samples were Group A (control), Group B (silicon carbide [SiC] paper abrasion 80 grit size), and Group C (erbium-doped yttrium aluminum garnet laser etching). Then, the samples were coated with primer and bonded to maxillofacial silicone. The samples were subjected to shear BS test in an universal testing machine after 24 h of fabrication and after 200 h of accelerated aging. The results were statistically analyzed using one-way ANOVA and Tukey's HSD post hoc test. The shear BS test after 24 h of fabrication showed better BS in SiC paper abrasion. The shear BS test after 200 h of accelerated aging showed better BS in laser etching compared to SiC abrasion. Laser etching produced better shear BS compared to conventional SiC paper abrasion after 200 h of accelerated aging process.

Initial Isotopic Heterogeneities in ZAGAMI: Evidence of a Complex Magmatic History

NASA Technical Reports Server (NTRS)

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

2006-01-01

Interpretations of Zagami s magmatic history range from complex [1,2] to relatively simple [3]. Discordant radiometric ages led to a suggestion that the ages had been reset [4]. In an attempt to identify the mechanism, Rb-Sr isochrons were individually determined for both fine-grained and coarse-grained Zagami [5]. Ages of approx.180 Ma were obtained from both lithologies, but the initial Sr-87/Sr-86 (ISr) of the fine-grained lithology was higher by 8.6+/-0.4 e-units. Recently, a much older age of approx.4 Ga has been advocated [6]. Here, we extend our earlier investigation [5]. Rb-Sr Data: In [5] we applied identical, simplified, procedures to both lithologies to test whether a grain-size dependent process such as thermally-driven subsolidus isotopic reequilibration had caused age-resetting. Minerals were separated only by density. In the present experiment, purer mineral separates were analysed with improved techniques. Combined Rb-Sr results give ages (T) = 166+/-12 Ma and 177+/-9 Ma and I(subSr) = 0.72174+/-9 and 0.72227+/-7 for the coarse-grained and fine-grained lithologies, respectively. ISr in the fine-grained sample is thus higher than in the coarse-grained sample by 7.3+/-1.6 e-units. The results for the coarse-grained lithology are in close agreement with T = 166+/-6 Ma, ISr = 0.72157+/-8 for an adjacent sample [7] and T = 178+/-4 Ma, ISr = 0.72151+/-5 [4, adjusted] for a separate sample. Thus, fine-grained Zagami appears on average to be less typical of the bulk than coarse-grained Zagami.

The impact of an unfavorable depression course on network size and loneliness in older people: a longitudinal study in the community.

PubMed

Houtjes, Wim; van Meijel, Berno; van de Ven, Peter M; Deeg, Dorly; van Tilburg, Theo; Beekman, Aartjan

2014-10-01

This work aims to gain insight into the long-term impact of depression course on social network size and perceived loneliness in older people living in the community. Within a large representative sample of older people in the community (Longitudinal Aging Study Amsterdam (LASA)), participants with clinically relevant levels of depressive symptoms (scores >16 on the Center for Epidemiological Studies Depression Scale) were followed up over a period of 13 years of the LASA study (five waves). General estimating equations were used to estimate the impact of depression course on network size and loneliness and the interaction with gender and age. An unfavorable course of depression was found to be associated with smaller network sizes and higher levels of loneliness over time, especially in men and older participants. The findings of this study stress the importance of clinical attention to the negative consequences of chronicity in depressed older people. Clinicians should assess possible erosion of the social network over time and be aware of increased feelings of loneliness in this patient group. Copyright © 2014 John Wiley & Sons, Ltd.

Pubertal development of the first cohort of young adults conceived by in-vitro fertilization in the United States

PubMed Central

Beydoun, Hind A.; Sicignano, Nicholas; Beydoun, May; Bocca, Silvina; Stadtmauer, Laurel; Oehninger, Sergio

2010-01-01

Objective To characterize pubertal development of the first generation of young adults born as a result of in-vitro fertilization (IVF). Demographic, clinical and body size characteristics were examined in relation to developmental milestones. Design Cross-sectional. Setting Academic center. Patients Young adults (18–26 years) conceived by IVF (no gamete/embryo manipulation), 1981–1990. Intervention Self-administered questionnaire. Main outcome measures Age at puberty onset, body size. Results Of 560 eligible young adults, 173 completed the survey (response rate=30.9%). We analyzed data on 166 respondents, 71 males and 95 females. No cases of delayed or precocious puberty were observed in the study sample. As expected, age at puberty onset was significantly higher (P < 0.0001) among males (12.3 years) compared to females (11.5 years). A few developmental milestones were predicted by maternal age and infertility diagnoses. For both genders, a direct association was noted between age at puberty onset and height achieved in young adulthood. Structural equations models suggested an inverse relationship of female gender with age at puberty onset and body mass index. Conclusions IVF-conceived young adults did not exhibit pubertal abnormalities. Female gender and age at puberty onset independently predicted body mass index of IVF offspring in young adulthood. PMID:20547390

The influence of social support and perceived stress on response time inconsistency.

PubMed

Phibbs, Sandi; Stawski, Robert S; MacDonald, Stuart W S; Munoz, Elizabeth; Smyth, Joshua M; Sliwinski, Martin J

2017-11-24

Lack of social support and high levels of stress represent potentially modifiable risk factors for cognitive aging. In this study we examined the relationships between these two risk factors and response time inconsistency (RTI), or trial-to-trial variability in choice response time tasks. RTI is an early indicator of declining cognitive health, and examining the influence of modifiable psychosocial risk factors on RTI is important for understanding and promoting cognitive health during adulthood and old age. Using data from a community sample study (n = 317; M age = 49, range = 19-83), we examined the effects of social support, including size of network and satisfaction with support, global perceived stress, and their interactions on RTI. Neither size of network nor satisfaction with support was associated with RTI independent of perceived stress. Stress was positively associated with increased RTI on all tasks, independent of social support. Perceived stress did not interact with either dimension of social support to predict RTI, and perceived stress effects were invariant across age and sex. Perceived stress, but not social support, may be a unique and modifiable risk factor for normal and pathological cognitive aging. Discussion focuses on the importance of perceived stress and its impact on RTI in supporting cognitive health in adulthood and old age.

Allometric modelling of peak oxygen uptake in male soccer players of 8-18 years of age.

PubMed

Valente-Dos-Santos, João; Coelho-E-Silva, Manuel J; Tavares, Óscar M; Brito, João; Seabra, André; Rebelo, António; Sherar, Lauren B; Elferink-Gemser, Marije T; Malina, Robert M

2015-03-01

Peak oxygen uptake (VO2peak) is routinely scaled as mL O2 per kilogram body mass despite theoretical and statistical limitations of using ratios. To examine the contribution of maturity status and body size descriptors to age-associated inter-individual variability in VO2peak and to present static allometric models to normalize VO2peak in male youth soccer players. Total body and estimates of total and regional lean mass were measured with dual energy X-ray absorptiometry in a cross-sectional sample of Portuguese male soccer players. The sample was divided into three age groups for analysis: 8-12 years, 13-15 years and 16-18 years. VO2peak was estimated using an incremental maximal exercise test on a motorized treadmill. Static allometric models were used to normalize VO2peak. The independent variables with the best statistical fit explained 72% in the younger group (lean body mass: k = 1.07), 52% in mid-adolescent players (lean body mass: k = 0.93) and 31% in the older group (body mass: k = 0.51) of variance in VO2peak. The inclusion of the exponential term pubertal status marginally increased the explained variance in VO2peak (adjusted R(2 )= 36-75%) and provided statistical adjustments to the size descriptors coefficients. The allometric coefficients and exponents evidenced the varying inter-relationship among size descriptors and maturity status with aerobic fitness from early to late-adolescence. Lean body mass, lean lower limbs mass and body mass combined with pubertal status explain most of the inter-individual variability in VO2peak among youth soccer players.

Comparison of hard tissues that are useful for DNA analysis in forensic autopsy.

PubMed

Kaneko, Yu; Ohira, Hiroshi; Tsuda, Yukio; Yamada, Yoshihiro

2015-11-01

Forensic analysis of DNA from hard tissues can be important when investigating a variety of cases resulting from mass disaster or criminal cases. This study was conducted to evaluate the most suitable tissues, method and sample size for processing of hard tissues prior to DNA isolation. We also evaluated the elapsed time after death in relation to the quantity of DNA extracted. Samples of hard tissues (37 teeth, 42 skull, 42 rib, and 39 nails) from 42 individuals aged between 50 and 83 years were used. The samples were taken from remains following forensic autopsy (from 2 days to 2 years after death). To evaluate the integrity of the nuclear DNA isolated, the percentage of allele calls for short tandem repeat profiles were compared between the hard tissues. DNA typing results indicated that until 1 month after death, any of the four hard tissue samples could be used as an alternative to teeth, allowing analysis of all of the loci. However, in terms of the sampling site, collection method and sample size adjustment, the rib appeared to be the best choice in view of the ease of specimen preparation. Our data suggest that the rib could be an alternative hard tissue sample for DNA analysis of human remains. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Seroprevalence and some correlates of Helicobacter pylori at adult ages in Gülveren Health District, Ankara, Turkey.

PubMed Central

Akin, L.; Tezcan, S.; Hascelik, G.; Cakir, B.

2004-01-01

The purpose of the study was to detect the frequency and distribution of Helicobacter pylori in the Gülveren Health Centre service area among residents aged between 25 and 64 years and to evaluate the relation of H. pylori infections with general health status, socioeconomic status, and some lifestyle habits. The study included a representative sample of Gülveren Health Centre residents, aged between 25 and 64 years. A stratified random sample of 1672 individuals was selected for study purposes out of 10,569 residents, stratified by age and gender. A standardized questionnaire was completed for all study participants using a face-to-face interview and all participants were invited to the local health centre for a thorough physical examination and blood tests. The overall prevalence of H. pylori was found to be 77.5 % among individuals aged between 25 and 64 years. The frequency of H. pylori was higher among individuals with low socioeconomic status; those who migrated to Ankara after the age of 20 years; members of large families (household size of 4 or above); non-alcohol drinkers; and those who regularly drink tea. PMID:15473147

Measurements of cloud condensation nuclei activity and droplet activation kinetics of wet processed regional dust samples and minerals

NASA Astrophysics Data System (ADS)

Kumar, P.; Sokolik, I. N.; Nenes, A.

2011-04-01

This study reports laboratory measurements of particle size distributions, cloud condensation nuclei (CCN) activity, and droplet activation kinetics of wet generated aerosols from clays, calcite, quartz, and desert soil samples from Northern Africa, East Asia/China, and Northern America. The dependence of critical supersaturation, sc, on particle dry diameter, Ddry, is used to characterize particle-water interactions and assess the ability of Frenkel-Halsey-Hill adsorption activation theory (FHH-AT) and Köhler theory (KT) to describe the CCN activity of the considered samples. Regional dust samples produce unimodal size distributions with particle sizes as small as 40 nm, CCN activation consistent with KT, and exhibit hygroscopicity similar to inorganic salts. Clays and minerals produce a bimodal size distribution; the CCN activity of the smaller mode is consistent with KT, while the larger mode is less hydrophilic, follows activation by FHH-AT, and displays almost identical CCN activity to dry generated dust. Ion Chromatography (IC) analysis performed on regional dust samples indicates a soluble fraction that cannot explain the CCN activity of dry or wet generated dust. A mass balance and hygroscopicity closure suggests that the small amount of ions (of low solubility compounds like calcite) present in the dry dust dissolve in the aqueous suspension during the wet generation process and give rise to the observed small hygroscopic mode. Overall these results identify an artifact that may question the atmospheric relevance of dust CCN activity studies using the wet generation method. Based on a threshold droplet growth analysis, wet generated mineral aerosols display similar activation kinetics compared to ammonium sulfate calibration aerosol. Finally, a unified CCN activity framework that accounts for concurrent effects of solute and adsorption is developed to describe the CCN activity of aged or hygroscopic dusts.

Uranium-series dating of pedogenic silica and carbonate, Crater Flat, Nevada

NASA Astrophysics Data System (ADS)

Ludwig, K. R.; Paces, J. B.

2002-02-01

A 230Th-234U-238U dating study on pedogenic silica-carbonate clast rinds and matrix laminae from alluvium in Crater Flat, Nevada was conducted using small-sample thermal-ionization mass spectrometry (TIMS) analyses on a large suite of samples. Though the 232Th content of these soils is not particularly low (mostly 0.1-9 ppm), the high U content of the silica component (mostly 4-26 ppm) makes them particularly suitable for 230Th/U dating on single, 10 to 200 mg totally-digested samples using TIMS. We observed that (1) both micro- (within-rind) and macro-stratigraphic (mappable deposit) order of the 230Th/U ages were preserved in all cases; (2) back-calculated initial 234U/238U fall in a restricted range (typically 1.67±0.19), so that 234U/238U ages with errors of about 100 kyr (2σ) could be reliably determined for the oldest, 400 to 1000 ka rinds; and (3) though 13 of the samples were >350 ka, only three showed evidence for an open-system history, even though the sensitivity of such old samples to isotopic disruption is very high. An attempt to use leach-residue techniques to separate pedogenic from detrital U and Th failed, yielding corrupt 230Th/U ages. We conclude that 230Th/U ages determined from totally dissolved, multiple sub-mm size subsamples provide more reliable estimates of soil chronology than methods employing larger samples, chemical enhancement of 238U/232Th, or isochrons.

Plasma asymmetric dimethylarginine, L-arginine and left ventricular structure and function in a community-based sample.

PubMed

Lieb, Wolfgang; Benndorf, Ralf A; Benjamin, Emelia J; Sullivan, Lisa M; Maas, Renke; Xanthakis, Vanessa; Schwedhelm, Edzard; Aragam, Jayashri; Schulze, Friedrich; Böger, Rainer H; Vasan, Ramachandran S

2009-05-01

Increasing evidence indicates that cardiac structure and function are modulated by the nitric oxide (NO) system. Elevated plasma concentrations of asymmetric dimethylarginine (ADMA; a competitive inhibitor of NO synthase) have been reported in patients with end-stage renal disease. It is unclear if circulating ADMA and L-arginine levels are related to cardiac structure and function in the general population. We related plasma ADMA and L-arginine (the amino acid precursor of NO) to echocardiographic left ventricular (LV) mass, left atrial (LA) size and fractional shortening (FS) using multivariable linear regression analyses in 1919 Framingham Offspring Study participants (mean age 57 years, 58% women). Overall, neither ADMA or L-arginine, nor their ratio was associated with LV mass, LA size and FS in multivariable models (p>0.10 for all). However, we observed effect modification by obesity of the relations of ADMA and LA size (p for interaction p=0.04): ADMA was positively related to LA size in obese individuals (adjusted-p=0.0004 for trend across ADMA quartiles) but not in non-obese people. In our large community-based sample, plasma ADMA and l-arginine concentrations were not related to cardiac structure or function. The observation of positive relations of LA size and ADMA in obese individuals warrants confirmation.

Ferromagnetic resonance studies of lunar core stratigraphy

NASA Technical Reports Server (NTRS)

Housley, R. M.; Cirlin, E. H.; Goldberg, I. B.; Crowe, H.

1976-01-01

We first review the evidence which links the characteristic ferromagnetic resonance observed in lunar fines samples with agglutinatic glass produced primarily by micrometeorite impacts and present new results on Apollo 15, 16, and 17 breccias which support this link by showing that only regolith breccias contribute significantly to the characteristic FMR intensity. We then provide a calibration of the amount of Fe metal in the form of uniformly magnetized spheres required to give our observed FMR intensities and discuss the theoretical magnetic behavior to be expected of Fe spheres as a function of size. Finally, we present FMR results on samples from every 5 mm interval in the core segments 60003, 60009, and 70009. These results lead us to suggest: (1) that secondary mixing may generally be extensive during regolith deposition so that buried regolith surfaces are hard to recognize or define; and (2) that local grinding of rocks and pebbles during deposition may lead to short scale fluctuations in grain size, composition, and apparent exposure age of samples.

Chi-Squared Test of Fit and Sample Size-A Comparison between a Random Sample Approach and a Chi-Square Value Adjustment Method.

PubMed

Bergh, Daniel

2015-01-01

Chi-square statistics are commonly used for tests of fit of measurement models. Chi-square is also sensitive to sample size, which is why several approaches to handle large samples in test of fit analysis have been developed. One strategy to handle the sample size problem may be to adjust the sample size in the analysis of fit. An alternative is to adopt a random sample approach. The purpose of this study was to analyze and to compare these two strategies using simulated data. Given an original sample size of 21,000, for reductions of sample sizes down to the order of 5,000 the adjusted sample size function works as good as the random sample approach. In contrast, when applying adjustments to sample sizes of lower order the adjustment function is less effective at approximating the chi-square value for an actual random sample of the relevant size. Hence, the fit is exaggerated and misfit under-estimated using the adjusted sample size function. Although there are big differences in chi-square values between the two approaches at lower sample sizes, the inferences based on the p-values may be the same.

A model-based approach to sample size estimation in recent onset type 1 diabetes.

PubMed

Bundy, Brian N; Krischer, Jeffrey P

2016-11-01

The area under the curve C-peptide following a 2-h mixed meal tolerance test from 498 individuals enrolled on five prior TrialNet studies of recent onset type 1 diabetes from baseline to 12 months after enrolment were modelled to produce estimates of its rate of loss and variance. Age at diagnosis and baseline C-peptide were found to be significant predictors, and adjusting for these in an ANCOVA resulted in estimates with lower variance. Using these results as planning parameters for new studies results in a nearly 50% reduction in the target sample size. The modelling also produces an expected C-peptide that can be used in observed versus expected calculations to estimate the presumption of benefit in ongoing trials. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The analysis of various size, visually selected and density and magnetically separated fractions of Luna 16 and 20 samples

NASA Technical Reports Server (NTRS)

Eglinton, G.; Gowar, A. P.; Jull, A. J. T.; Pillinger, C. T.; Agrell, S. O.; Agrell, J. E.; Long, J. V. P.; Bowie, S. H. U.; Simpson, P. R.; Beckinsale, R. D.

1977-01-01

Samples of Luna 16 and 20 have been separated according to size, visual appearance, density, and magnetic susceptibility. Selected aliquots were examined in eight British laboratories. The studies included mineralogy and petrology, selenochronology, magnetic characteristics, Mossbauer spectroscopy, oxygen isotope ratio determinations, cosmic ray track and thermoluminescence investigations, and carbon chemistry measurements. Luna 16 and 20 are typically mare and highland soils, comparing well with their Apollo counterparts, Apollo 11 and 16, respectively. Both soils are very mature (high free iron, carbide, and methane and cosmogenic Ar), while Luna 16, but not Luna 20, is characterized by a high content of glassy materials. An aliquot of anorthosite fragments, handpicked from Luna 20, had a gas retention age of about 4.3 plus or minus 0.1 Gy.

Does Static-99 predict recidivism among older sexual offenders?

PubMed

Hanson, R K

2006-10-01

Static-99 (Hanson & Thornton, 2000) is the most commonly used actuarial risk tool for estimating sexual offender recidivism risk. Recent research has suggested that its methods of accounting for the offenders' ages may be insufficient to capture declines in recidivism risk associated with advanced age. Using data from 8 samples (combined size of 3,425 sexual offenders), the present study found that older offenders had lower Static-99 scores than younger offenders and that Static-99 was moderately accurate in estimating relative recidivism risk in all age groups. Older offenders, however, had lower sexual recidivism rates than would be expected based on their Static-99 risk categories. Consequently, evaluators using Static-99 should considered advanced age in their overall estimate of risk.

A blood-based proteomic classifier for the molecular characterization of pulmonary nodules.

PubMed

Li, Xiao-jun; Hayward, Clive; Fong, Pui-Yee; Dominguez, Michel; Hunsucker, Stephen W; Lee, Lik Wee; McLean, Matthew; Law, Scott; Butler, Heather; Schirm, Michael; Gingras, Olivier; Lamontagne, Julie; Allard, Rene; Chelsky, Daniel; Price, Nathan D; Lam, Stephen; Massion, Pierre P; Pass, Harvey; Rom, William N; Vachani, Anil; Fang, Kenneth C; Hood, Leroy; Kearney, Paul

2013-10-16

Each year, millions of pulmonary nodules are discovered by computed tomography and subsequently biopsied. Because most of these nodules are benign, many patients undergo unnecessary and costly invasive procedures. We present a 13-protein blood-based classifier that differentiates malignant and benign nodules with high confidence, thereby providing a diagnostic tool to avoid invasive biopsy on benign nodules. Using a systems biology strategy, we identified 371 protein candidates and developed a multiple reaction monitoring (MRM) assay for each. The MRM assays were applied in a three-site discovery study (n = 143) on plasma samples from patients with benign and stage IA lung cancer matched for nodule size, age, gender, and clinical site, producing a 13-protein classifier. The classifier was validated on an independent set of plasma samples (n = 104), exhibiting a negative predictive value (NPV) of 90%. Validation performance on samples from a nondiscovery clinical site showed an NPV of 94%, indicating the general effectiveness of the classifier. A pathway analysis demonstrated that the classifier proteins are likely modulated by a few transcription regulators (NF2L2, AHR, MYC, and FOS) that are associated with lung cancer, lung inflammation, and oxidative stress networks. The classifier score was independent of patient nodule size, smoking history, and age, which are risk factors used for clinical management of pulmonary nodules. Thus, this molecular test provides a potential complementary tool to help physicians in lung cancer diagnosis.

The Association Between Social Skills and Mental Health in School-Aged Children with Autism Spectrum Disorder, With and Without Intellectual Disability.

PubMed

Ratcliffe, Belinda; Wong, Michelle; Dossetor, David; Hayes, Susan

2015-08-01

Autism Spectrum Disorder (ASD) is associated with social skills deficits and co-occurring mental health difficulties. ASD frequently co-occurs with Intellectual Disability (ID). There is scant literature exploring the association between social skills and mental health in children with ASD, with or without ID. Participants were 292 children aged six to 13 with ASD (217 without ID; 76 with Mild ID). Parents and teachers rated social skills and mental health using standardised questionnaires. Greater mental health difficulties were associated with greater social responsiveness difficulties and poorer social skills across the sample. Effect sizes were large. Social skills explained a significant proportion of the variance in mental health scores across the sample. The study has important implications for treatment and future research.

Validation of a fecal scoring scale in puppies during the weaning period.

PubMed

Grellet, Aurélien; Feugier, Alexandre; Chastant-Maillard, Sylvie; Carrez, Bruno; Boucraut-Baralon, Corine; Casseleux, Gregory; Grandjean, Dominique

2012-10-01

In puppies weaning is a high risk period. Fecal changes are frequent and can be signs of infection by digestive pathogens (bacteria, viruses, parasites) and indicators of nutritional and environmental stress. The aim of this study was to define a pathological fecal score for weaning puppies, and to study the impact on that score of two intestinal viruses (canine parvovirus type 2 and canine coronavirus). For this, the quality of stools was evaluated on 154 puppies between 4 and 8 weeks of age (100 from small breeds and 54 from large breeds). The scoring was performed immediately after a spontaneous defecation based on a 13-point scale (from 1; liquid to 13; dry and hard feces). Fecal samples were frozen for further viral analysis. Each puppy was weighed once a week during the study period. The fecal score regarded as pathological was the highest score associated with a significant reduction in average daily gain (ADG). Fecal samples were checked by semi-quantitative PCR or RT-PCR for canine parvovirus type 2 and canine coronavirus identification, respectively. The quality of feces was affected by both age and breed size. In small breeds, the ADG was significantly reduced under a fecal score of 6 and 7 for puppies at 4-5 and 6-8 weeks of age, respectively. In large breeds, the ADG was significantly reduced under a fecal score of 5 whatever the age of the puppy. Whereas a high viral load of canine parvovirus type 2 significantly impacted feces quality, no effect was recorded for canine coronavirus. This study provides an objective threshold for evaluation of fecal quality in weaning puppies. It also emphasizes the importance to be given to age and breed size in that evaluation. Copyright © 2012 Elsevier B.V. All rights reserved.

Fossil shrews from Honduras and their significance for late glacial evolution in body size (Mammalia: Soricidae: Cryptotis)

USGS Publications Warehouse

Woodman, N.; Croft, D.A.

2005-01-01

Our study of mammalian remains excavated in the 1940s from McGrew Cave, north of Copan, Honduras, yielded an assemblage of 29 taxa that probably accumulated predominantly as the result of predation by owls. Among the taxa present are three species of small-eared shrews, genus Cryptotis. One species, Cryptotis merriami, is relatively rare among the fossil remains. The other two shrews, Cryptotis goodwini and Cryptotis orophila, are abundant and exhibit morpho metrical variation distinguishing them from modern populations. Fossils of C. goodwini are distinctly and consistently smaller than modern members of the species. To quantify the size differences, we derived common measures of body size for fossil C. goodwini using regression models based on modern samples of shrews in the Cryptotis mexicana-group. Estimated mean length of head and body for the fossil sample is 72-79 mm, and estimated mean mass is 7.6-9.6 g. These numbers indicate that the fossil sample averaged 6-14% smaller in head and body length and 39-52% less in mass than the modern sample and that increases of 6-17% in head and body length and 65-108% in mass occurred to achieve the mean body size of the modern sample. Conservative estimates of fresh (wet) food intake based on mass indicate that such a size increase would require a 37-58% increase in daily food consumption. In contrast to C. goodwini, fossil C. orophila from the cave is not different in mean body size from modern samples. The fossil sample does, however, show slightly greater variation in size than is currently present throughout the modern geographical distribution of the taxon. Moreover, variation in some other dental and mandibular characters is more constrained, exhibiting a more direct relationship to overall size. Our study of these species indicates that North American shrews have not all been static in size through time, as suggested by some previous work with fossil soricids. Lack of stratigraphic control within the site and our failure to obtain reliable radiometric dates on remains restrict our opportunities to place the site in a firm temporal context. However, the morphometrical differences we document for fossil C. orophila and C. goodwini show them to be distinct from modern populations of these shrews. Some other species of fossil mammals from McGrew Cave exhibit distinct size changes of the magnitudes experienced by many northern North American and some Mexican mammals during the transition from late glacial to Holocene environmental conditions, and it is likely that at least some of the remains from the cave are late Pleistocene in age. One curious factor is that, whereas most mainland mammals that exhibit large-scale size shifts during the late glacial/postglacial transition experienced dwarfing, C. goodwini increased in size. The lack of clinal variation in modern C. goodwini supports the hypothesis that size evolution can result from local selection rather than from cline translocation. Models of size change in mammals indicate that increased size, such as that observed for C. goodwini, are a likely consequence of increased availability of resources and, thereby, a relaxation of selection during critical times of the year.

Radioactivities in returned lunar materials and in meteorites

NASA Technical Reports Server (NTRS)

Fireman, E. L.

1982-01-01

Carbon-14 measurements were made for meteorites with a Van der Graaf accelerator. Accelerator C-14 dating improved the precision by a factor of ten, allowed the use of smaller sample sizes, and gave speedier results than C-14 dating with counters. A methodology for determining the terrestrial ages of several antarctic meteorites is described and the results are listed.

Quality of Life in Autism across the Lifespan: A Meta-Analysis

ERIC Educational Resources Information Center

van Heijst, Barbara F. C.; Geurts, Hilde M.

2015-01-01

Autism is a lifelong neurodevelopmental disorder, with a known impact on quality of life. Yet the developmental trajectory of quality of life is not well understood. First, the effect of age on quality of life was studied with a meta-analysis. Our meta-analysis included 10 studies (published between 2004 and 2012) with a combined sample size of…

Barriers to Breast Cancer Screening Among Latinas in the U.S.-Mexico Border Region

DTIC Science & Technology

2009-05-01

Catholic religion, % 22.13 AHEAD cohort, % 51.53 Age, years 68.25 Education, years 12.26 Household wealth, US$ 100,000 2.99 Sample size 1143 AHEAD, Asset and...Methods Based on Ranks. San Francisco: Holden-Day; 1975. 13. Franses PH, Cramer M. On the number of categories in an ordered regression model. Erasmus

Diurnal Cortisol Secretion at Home and in Child Care: A Prospective Study of 2-Year-Old Toddlers

ERIC Educational Resources Information Center

Ouellet-Morin, Isabelle; Tremblay, Richard E.; Boivin, Michel; Meaney, Michael; Kramer, Michael; Cote, Sylvana M.

2010-01-01

Background: Previous studies indicate that children may experience disrupted cortisol secretion in child care. The extent to which this is a transient or long-term disruption is not known, as most studies have relied on cross-sectional designs, and age-heterogeneous small sample sizes. This study aims to (a) compare cortisol secretion measured at…

Nonmarital Fertility and the Effects of Divorce Rates on Youth Suicide Rates

ERIC Educational Resources Information Center

Messner, Steven F.; Bjarnason, Thoroddur; Raffalovich, Lawrence E.; Robinson, Bryan K.

2006-01-01

Using pooled, time-series data for a sample of 15 developed nations, we assess the effect of divorce rates on gender-specific suicide rates for youths aged 15-19 with models of relative cohort size, lagged nonmarital fertility, and an interaction term for divorce rates and nonmarital fertility. The results reveal that, for young men, relative…

Anomalous permittivity in fine-grain barium titanate

NASA Astrophysics Data System (ADS)

Ostrander, Steven Paul

Fine-grain barium titanate capacitors exhibit anomalously large permittivity. It is often observed that these materials will double or quadruple the room temperature permittivity of a coarse-grain counterpart. However, aside from a general consensus on this permittivity enhancement, the properties of the fine-grain material are poorly understood. This thesis examines the effect of grain size on dielectric properties of a self-consistent set of high density undoped barium titanate capacitors. This set included samples with grain sizes ranging from submicron to ˜20 microns, and with densities generally above 95% of the theoretical. A single batch of well characterized powder was milled, dry-pressed then isostatically-pressed. Compacts were fast-fired, but sintering temperature alone was used to control the grain size. With this approach, the extrinsic influences are minimized within the set of samples, but more importantly, they are normalized between samples. That is, with a single batch of powder and with identical green processing, uniform impurity concentration is expected. The fine-grain capacitors exhibited a room temperature permittivity of ˜5500 and dielectric losses of ˜2%. The Curie-temperature decreased by {˜}5sp°C from that of the coarse-grain material, and the two ferroelectric-ferroelectric phase transition temperatures increased by {˜}10sp°C. The grain size induced permittivity enhancement was only active in the tetragonal and orthorhombic phases. Strong dielectric anomalies were observed in samples with grain size as small as {˜}0.4\\ mum. It is suggested that the strong first-order character observed in the present data is related to control of microstructure and stoichiometry. Grain size effects on conductivity losses, ferroelectric losses, ferroelectric dispersion, Maxwell-Wagner dispersion, and dielectric aging of permittivity and loss were observed. For the fine-grain material, these observations suggest the suppression of domain wall motion below the Curie transition, and the suppression of conductivity above the Curie transition.

Our Health Counts Toronto: using respondent-driven sampling to unmask census undercounts of an urban indigenous population in Toronto, Canada.

PubMed

Rotondi, Michael A; O'Campo, Patricia; O'Brien, Kristen; Firestone, Michelle; Wolfe, Sara H; Bourgeois, Cheryllee; Smylie, Janet K

2017-12-26

To provide evidence of the magnitude of census undercounts of 'hard-to-reach' subpopulations and to improve estimation of the size of the urban indigenous population in Toronto, Canada, using respondent-driven sampling (RDS). Respondent-driven sampling. The study took place in the urban indigenous community in Toronto, Canada. Three locations within the city were used to recruit study participants. 908 adult participants (15+) who self-identified as indigenous (First Nation, Inuit or Métis) and lived in the city of Toronto. Study participants were generally young with over 60% of indigenous adults under the age of 45 years. Household income was low with approximately two-thirds of the sample living in households which earned less than $C20 000 last year. We collected baseline data on demographic characteristics, including indigenous identity, age, gender, income, household type and household size. Our primary outcome asked: 'Did you complete the 2011 Census Canada questionnaire?' Using RDS and our large-scale survey of the urban indigenous population in Toronto, Canada, we have shown that the most recent Canadian census underestimated the size of the indigenous population in Toronto by a factor of 2 to 4. Specifically, under conservative assumptions, there are approximately 55 000 (95% CI 45 000 to 73 000) indigenous people living in Toronto, at least double the current estimate of 19 270. Our indigenous enumeration methods, including RDS and census completion information will have broad impacts across governmental and health policy, potentially improving healthcare access for this community. These novel applications of RDS may be relevant for the enumeration of other 'hard-to-reach' populations, such as illegal immigrants or homeless individuals in Canada and beyond. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Serological survey of Neospora caninum infection in cattle herds from Western Romania.

PubMed

Imre, Kálmán; Morariu, Sorin; Ilie, Marius S; Imre, Mirela; Ferrari, Nicola; Genchi, Claudio; Dărăbuş, Gheorghe

2012-06-01

Serum samples from 376 randomly selected adult cattle, from 25 farms located in 3 counties (Arad, Bihor, and Timiş) from western Romania, were sampled for Neospora caninum antibodies using a commercial ELISA-kit. Seroprevalence values and risk factors for neosporosis (cow age, breed, herd size, farming system, previous abortion, and number of farm dogs) were examined using a generalized linear mixed model with a binomial distribution. Overall, the seroprevalence of N. caninum was 27.7% (104/376) with a prevalence of 27.9% (24/86) in Arad, 26.9% (25/93) in Bihor, and 27.9% (55/197) in Timiş. Of 25 cattle herds, 23 were seropositive with a prevalence ranging from 10.0 to 52.2%. No correlation was found between N. caninum seropositivity and age, breed, herd size, breeding system, and previous abortion. The number of farm dogs was the only factor (P(Wald)  =  0.03) positively associated with seroprevalence in cows and can be considered the risk factor in the acquiring of infection. The present work is the first regarding serological evidence of N. caninum infection in cattle from western Romania.

Variability of Phytoplankton Size Structure in Response to Changes in Coastal Upwelling Intensity in the Southwestern East Sea

NASA Astrophysics Data System (ADS)

Shin, Jung-Wook; Park, Jinku; Choi, Jang-Geun; Jo, Young-Heon; Kang, Jae Joong; Joo, HuiTae; Lee, Sang Heon

2017-12-01

The aim of this study was to examine the size structure of phytoplankton under varying coastal upwelling intensities and to determine the resulting primary productivity in the southwestern East Sea. Samples of phytoplankton assemblages were collected on five occasions from the Hupo Bank, off the east coast of Korea, during 2012-2013. Because two major surface currents have a large effect on water mass transport in this region, we first performed a Backward Particle Tracking Experiment (BPTE) to determine the coastal sea from which the collected samples originated according to advection time of BPTE particles, following which we used upwelling age (UA) to determine the intensity of coastal upwelling in the region of origin for each sample. Only samples that were affected by coastal upwelling in the region of origin were included in subsequent analyses. We found that as UA increased, there was a decreasing trend in the concentration of picophytoplankton, and increasing trends in the concentration of nanophytoplankton and microphytoplankton. We also examined the relationship between the size structure of phytoplankton and primary productivity in the Ulleung Basin (UB), which has experienced significant variation over the past decade. We found that primary productivity in UB was closely related to the strength of the southerly wind, which is the most important mechanism for coastal upwelling in the southwestern East Sea. Thus, the size structure of phytoplankton is determined by the intensity of coastal upwelling, which is regulated by the southerly wind, and makes an important contribution to primary productivity.

[MESGI50 study: description of a cohort on Maturity and Satisfactory Ageing].

PubMed

Corominas Barnadas, Josep María; López-Pousa, Secundino; Vilalta-Franch, Joan; Calvó-Perxas, Laia; Juvinyà Canal, Dolors; Garre-Olmo, Josep

To describe the demographic, health and socio-economic characteristics of the participants in the Study on Maturity and Satisfactory Ageing in Girona (MESGI50 study). Population-based Study linked to the Survey of Health, Ageing, and Retirement in Europe (SHARE). The reference population was the inhabitants of the province of Girona (Spain) aged 50 and over. A probabilistic two-stage stratified cluster sampling according to the number of inhabitants and the degree of ageing of the population was used. Twenty-eight municipalities were randomly selected according to their type (demographically aged or young), and then stratified by the population size. The response rate was 65% with a mean of 1.7 eligible individuals per household and a final sample of 2,065 households and 3,331 participants. The design effect was 1.27. 52.9% were women and the mean age was 66.9 years (SD=11.5). The self-rated health status, hand grip strength, restriction in daily life activities and depressive symptomatology increased with age and more markedly in women. There were differences in alcohol consumption and eating patterns depending on the area of residence. The demographic, health and socio-economic characteristics during the ageing process differ depending on age group, gender, and area of residence. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Clinical Trials Targeting Aging and Age-Related Multimorbidity

PubMed Central

Crimmins, Eileen M; Grossardt, Brandon R; Crandall, Jill P; Gelfond, Jonathan A L; Harris, Tamara B; Kritchevsky, Stephen B; Manson, JoAnn E; Robinson, Jennifer G; Rocca, Walter A; Temprosa, Marinella; Thomas, Fridtjof; Wallace, Robert; Barzilai, Nir

2017-01-01

Abstract Background There is growing interest in identifying interventions that may increase health span by targeting biological processes underlying aging. The design of efficient and rigorous clinical trials to assess these interventions requires careful consideration of eligibility criteria, outcomes, sample size, and monitoring plans. Methods Experienced geriatrics researchers and clinical trialists collaborated to provide advice on clinical trial design. Results Outcomes based on the accumulation and incidence of age-related chronic diseases are attractive for clinical trials targeting aging. Accumulation and incidence rates of multimorbidity outcomes were developed by selecting at-risk subsets of individuals from three large cohort studies of older individuals. These provide representative benchmark data for decisions on eligibility, duration, and assessment protocols. Monitoring rules should be sensitive to targeting aging-related, rather than disease-specific, outcomes. Conclusions Clinical trials targeting aging are feasible, but require careful design consideration and monitoring rules. PMID:28364543

A Meta-Analysis on Antecedents and Outcomes of Detachment from Work.

PubMed

Wendsche, Johannes; Lohmann-Haislah, Andrea

2016-01-01

Detachment from work has been proposed as an important non-work experience helping employees to recover from work demands. This meta-analysis (86 publications, k = 91 independent study samples, N = 38,124 employees) examined core antecedents and outcomes of detachment in employee samples. With regard to outcomes, results indicated average positive correlations between detachment and self-reported mental (i.e., less exhaustion, higher life satisfaction, more well-being, better sleep) and physical (i.e., lower physical discomfort) health, state well-being (i.e., less fatigue, higher positive affect, more intensive state of recovery), and task performance (small to medium sized effects). However, average relationships between detachment and physiological stress indicators and work motivation were not significant while associations with contextual performance and creativity were significant, but negative. Concerning work characteristics, as expected, job demands were negatively related and job resources were positively related to detachment (small sized effects). Further, analyses revealed that person characteristics such as negative affectivity/neuroticism (small sized effect) and heavy work investment (medium sized effect) were negatively related to detachment whereas detachment and demographic variables (i.e., age and gender) were not related. Moreover, we found a medium sized average negative relationship between engagement in work-related activities during non-work time and detachment. For most of the examined relationships heterogeneity of effect sizes was moderate to high. We identified study design, samples' gender distribution, and affective valence of work-related thoughts as moderators for some of these aforementioned relationships. The results of this meta-analysis point to detachment as a non-work (recovery) experience that is influenced by work-related and personal characteristics which in turn is relevant for a range of employee outcomes.

A Meta-Analysis on Antecedents and Outcomes of Detachment from Work

PubMed Central

Wendsche, Johannes; Lohmann-Haislah, Andrea

2017-01-01

Detachment from work has been proposed as an important non-work experience helping employees to recover from work demands. This meta-analysis (86 publications, k = 91 independent study samples, N = 38,124 employees) examined core antecedents and outcomes of detachment in employee samples. With regard to outcomes, results indicated average positive correlations between detachment and self-reported mental (i.e., less exhaustion, higher life satisfaction, more well-being, better sleep) and physical (i.e., lower physical discomfort) health, state well-being (i.e., less fatigue, higher positive affect, more intensive state of recovery), and task performance (small to medium sized effects). However, average relationships between detachment and physiological stress indicators and work motivation were not significant while associations with contextual performance and creativity were significant, but negative. Concerning work characteristics, as expected, job demands were negatively related and job resources were positively related to detachment (small sized effects). Further, analyses revealed that person characteristics such as negative affectivity/neuroticism (small sized effect) and heavy work investment (medium sized effect) were negatively related to detachment whereas detachment and demographic variables (i.e., age and gender) were not related. Moreover, we found a medium sized average negative relationship between engagement in work-related activities during non-work time and detachment. For most of the examined relationships heterogeneity of effect sizes was moderate to high. We identified study design, samples' gender distribution, and affective valence of work-related thoughts as moderators for some of these aforementioned relationships. The results of this meta-analysis point to detachment as a non-work (recovery) experience that is influenced by work-related and personal characteristics which in turn is relevant for a range of employee outcomes. PMID:28133454

The role of novelty seeking as a predictor of substance use disorder outcomes in early adulthood.

PubMed

Foulds, James A; Boden, Joseph M; Newton-Howes, Giles M; Mulder, Roger T; Horwood, L John

2017-09-01

There has been a great deal of evidence showing that high novelty seeking (NS) is a risk factor for the development of substance use disorders (SUDs). However, the possible causal role of NS in SUDs is unconfirmed. The aim of this study was to examine the associations between NS at age 16 and SUDs from ages 18 to 35 years, net of a series of covariate factors. Longitudinal study of a birth cohort. Christchurch, New Zealand. General community sample with sample sizes ranging from n = 1011 (age 21) to n = 962 (age 35). The Composite International Diagnostic Interview was used to derive DSM-IV diagnoses of alcohol, nicotine, cannabis and other illicit SUDs at four time intervals from ages 18 to 35. NS was measured at age 16 using the Tridimensional Personality Questionnaire. An increase in NS was associated with increases in the prevalence of all four SUDs at age 18-35. Following adjustment for a broad range of covariate factors, estimated effect sizes (odds ratios) were reducing in magnitude, but remained moderate to large. Adjusted odds ratios of SUDs for the highest NS quartile compared to with the lowest were 2.0 [95% confidence interval (CI) = 1.5, 2.7] for alcohol; 1.8 (95% CI = 1.3, 2.7) for nicotine; 3.6 (95% CI = 2.4, 5.6) for cannabis and 5.1 (95% CI = 2.9, 9.2) for other illicit substances. The association between high novelty seeking and substance use disorders is not explained by common underlying individual factors and environmental exposures. This is consistent with the view that novelty seeking may play a causal role in the development of substance use disorders. © 2017 Society for the Study of Addiction.

Sample survey methods as a quality assurance tool in a general practice immunisation audit.

PubMed

Cullen, R

1994-04-27

In a multidoctor family practice there are often just too many sets of patients records to make it practical to repeat an audit by census of even an age band of the practice on a regular basis. This paper attempts to demonstrate how sample survey methodology can be incorporated into the quality assurance cycle. A simple random sample (with replacement) of 120 from 580 children with permanent records who were aged between 6 weeks and 2 years old from an Auckland general practice was performed, with sample size selected to give a predetermined precision. The survey was then repeated after 4 weeks. Both surveys were able to be completed within the course of a normal working day. An unexpectedly low level of under 2 years olds that were recorded as not overdue for any immunisations was found (22.5%) with only a modest improvement after a standard telephone/letter catch up campaign. Seventy-two percent of the sample held a group one community services card. The advantages of properly conducted sample surveys in producing useful estimates of known precision without disrupting office routines excessively were demonstrated. Through some attention to methodology, the trauma of a practice census can be avoided.

Diet- and body size-related attitudes and behaviors associated with vitamin supplement use in a representative sample of fourth-grade students in Texas.

PubMed

George, Goldy C; Hoelscher, Deanna M; Nicklas, Theresa A; Kelder, Steven H

2009-01-01

To examine diet- and body size-related attitudes and behaviors associated with supplement use in a representative sample of fourth-grade students in Texas. Cross-sectional data from the School Physical Activity and Nutrition study, a probability-based sample of schoolchildren. Children completed a questionnaire that assessed supplement use, food choices, diet-related attitudes, and physical activity; height and weight were measured. School classrooms. Representative sample of fourth-grade students in Texas (n = 5967; mean age = 9.7 years standard error of the mean [SEM] = .03 years, 46% Hispanic, 11% African-American). Previous day vitamin supplement consumption, diet- and body size-related attitudes, food choices, demographic factors, and physical activity. Multivariable logistic regression models, P < .05. The prevalence of supplement use was 29%. Supplement intake was associated with physical activity. Girls who used supplements were more likely to report positive body image and greater interest in trying new food. Relative to nonusers, supplement users were less likely to perceive that they always ate healthful food, although supplement use was associated with more healthful food choices in boys and girls (P < .001). The widespread use of supplements and clustering of supplement use with healthful diet and greater physical activity in fourth graders suggest that supplement use be closely investigated in studies of diet-disease precursor relations and lifestyle factors in children.

Effects of age, maturity and body dimensions on match running performance in highly trained under-15 soccer players.

PubMed

Buchheit, Martin; Mendez-Villanueva, Alberto

2014-01-01

The aim of the present study was to compare, in 36 highly trained under-15 soccer players, the respective effects of age, maturity and body dimensions on match running performance. Maximal sprinting (MSS) and aerobic speeds were estimated. Match running performance was analysed with GPS (GPSport, 1 Hz) during 19 international friendly games (n = 115 player-files). Total distance and distance covered >16 km h(-1) (D > 16 km h(-1)) were collected. Players advanced in age and/or maturation, or having larger body dimensions presented greater locomotor (Cohen's d for MSS: 0.5-1.0, likely to almost certain) and match running performances (D > 16 km h(-1): 0.2-0.5, possibly to likely) than their younger, less mature and/or smaller teammates. These age-, maturation- and body size-related differences were of larger magnitude for field test measures versus match running performance. Compared with age and body size (unclear to likely), maturation (likely to almost certainly for all match variables) had the greatest impact on match running performance. The magnitude of the relationships between age, maturation and body dimensions and match running performance were position-dependent. Within a single age-group in the present player sample, maturation had a substantial impact on match running performance, especially in attacking players. Coaches may need to consider players' maturity status when assessing their on-field playing performance.

No cross-sectional evidence for an increased relation of cognitive and sensory abilities in old age.

PubMed

Ihle, Andreas; Oris, Michel; Fagot, Delphine; Kliegel, Matthias

2017-04-01

A key question in gerontological research concerns whether good functioning can be maintained in some cognitive abilities in old age, even if deficits occur in other cognitive or sensory abilities. Our goals were to investigate relations of cognitive and sensory abilities in old age, whether these relations differed in size across old age, and whether this was affected by general cognitive ability (processing speed), educational level, and/or general health status. Two thousand eight hundred and twelve older adults (aged 65-101, M = 77.9 years) from the Vivre-Leben-Vivere survey served as cross-sectional sample for the present study. We administered psychometric tests on processing speed (the speed of cognitive processing), cognitive flexibility (the ability to alternate between cognitive operations), and verbal abilities (vocabulary). In addition, we interviewed individuals on their hearing, eyesight, educational level, and general health status. We regressed sizes of relations between abilities (calculated within each 1-year age tranche) on mean age within the corresponding age tranche, with the number of participants within the corresponding age tranche as case weights. We observed a decrease in relations between processing speed and cognitive flexibility in old age that was particularly pronounced in individuals with high educational level (r = -.41). In contrast, we did not find differences in relations between other cognitive and sensory abilities across old age, which held for different levels of general cognitive ability, education, and general health status. Present data do not support the view of a generally increased relation of cognitive and sensory abilities in old age.

Strengthening of Cu–Ni–Si alloy using high-pressure torsion and aging

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

Lee, Seungwon, E-mail: chominamlsw@gmail.com; WPI, International Institute for Carbon-Neutral Energy Research; Matsunaga, Hirotaka

2014-04-01

An age-hardenable Cu–2.9%Ni–0.6%Si alloy was subjected to high-pressure torsion. Aging behavior was investigated in terms of hardness, electrical conductivity and microstructural features. Transmission electron microscopy showed that the grain size is refined to ∼ 150 nm and the Vickers microhardness was significantly increased through the HPT processing. Aging treatment of the HPT-processed alloy led to a further increase in the hardness. Electrical conductivity is also improved with the aging treatment. It was confirmed that the simultaneous strengthening by grain refinement and fine precipitation is achieved while maintaining high electrical conductivity. Three dimensional atom probe analysis including high-resolution transmission electron microscopymore » revealed that nanosized precipitates having compositions of a metastable Cu{sub 3}Ni{sub 5}Si{sub 2} phase and a stable NiSi phase were formed in the Cu matrix by aging of the HPT-processed samples and these particles are responsible for the additional increase in strength after the HPT processing. - Highlights: • Grain refinement is achieved in Corson alloy the size of ∼150nm by HPT. • Aging at 300°C after HPT leads to further increase in the mechanical property. • Electrical conductivity reaches 40% IACS after aging for 100 h. • 3D-APT revealed the formation of nanosized-precipitates during aging treatment. • Simultaneous hardening in both grain refinement and precipitation is achieved.« less

Annual age-grouping and athlete development: a meta-analytical review of relative age effects in sport.

PubMed

Cobley, Stephen; Baker, Joseph; Wattie, Nick; McKenna, Jim

2009-01-01

Annual age-grouping is a common organizational strategy in sport. However, such a strategy appears to promote relative age effects (RAEs). RAEs refer both to the immediate participation and long-term attainment constraints in sport, occurring as a result of chronological age and associated physical (e.g. height) differences as well as selection practices in annual age-grouped cohorts. This article represents the first meta-analytical review of RAEs, aimed to collectively determine (i) the overall prevalence and strength of RAEs across and within sports, and (ii) identify moderator variables. A total of 38 studies, spanning 1984-2007, containing 253 independent samples across 14 sports and 16 countries were re-examined and included in a single analysis using odds ratios and random effects procedures for combining study estimates. Overall results identified consistent prevalence of RAEs, but with small effect sizes. Effect size increased linearly with relative age differences. Follow-up analyses identified age category, skill level and sport context as moderators of RAE magnitude. Sports context involving adolescent (aged 15-18 years) males, at the representative (i.e. regional and national) level in highly popular sports appear most at risk to RAE inequalities. Researchers need to understand the mechanisms by which RAEs magnify and subside, as well as confirm whether RAEs exist in female and more culturally diverse contexts. To reduce and eliminate this social inequality from influencing athletes' experiences, especially within developmental periods, direct policy, organizational and practitioner intervention is required.

A Re-Evaluation of the Size of the White Shark (Carcharodon carcharias) Population off California, USA

PubMed Central

Burgess, George H.; Bruce, Barry D.; Cailliet, Gregor M.; Goldman, Kenneth J.; Grubbs, R. Dean; Lowe, Christopher G.; MacNeil, M. Aaron; Mollet, Henry F.; Weng, Kevin C.; O'Sullivan, John B.

2014-01-01

White sharks are highly migratory and segregate by sex, age and size. Unlike marine mammals, they neither surface to breathe nor frequent haul-out sites, hindering generation of abundance data required to estimate population size. A recent tag-recapture study used photographic identifications of white sharks at two aggregation sites to estimate abundance in “central California” at 219 mature and sub-adult individuals. They concluded this represented approximately one-half of the total abundance of mature and sub-adult sharks in the entire eastern North Pacific Ocean (ENP). This low estimate generated great concern within the conservation community, prompting petitions for governmental endangered species designations. We critically examine that study and find violations of model assumptions that, when considered in total, lead to population underestimates. We also use a Bayesian mixture model to demonstrate that the inclusion of transient sharks, characteristic of white shark aggregation sites, would substantially increase abundance estimates for the adults and sub-adults in the surveyed sub-population. Using a dataset obtained from the same sampling locations and widely accepted demographic methodology, our analysis indicates a minimum all-life stages population size of >2000 individuals in the California subpopulation is required to account for the number and size range of individual sharks observed at the two sampled sites. Even accounting for methodological and conceptual biases, an extrapolation of these data to estimate the white shark population size throughout the ENP is inappropriate. The true ENP white shark population size is likely several-fold greater as both our study and the original published estimate exclude non-aggregating sharks and those that independently aggregate at other important ENP sites. Accurately estimating the central California and ENP white shark population size requires methodologies that account for biases introduced by sampling a limited number of sites and that account for all life history stages across the species' range of habitats. PMID:24932483

A re-evaluation of the size of the white shark (Carcharodon carcharias) population off California, USA.

PubMed

Burgess, George H; Bruce, Barry D; Cailliet, Gregor M; Goldman, Kenneth J; Grubbs, R Dean; Lowe, Christopher G; MacNeil, M Aaron; Mollet, Henry F; Weng, Kevin C; O'Sullivan, John B

2014-01-01

White sharks are highly migratory and segregate by sex, age and size. Unlike marine mammals, they neither surface to breathe nor frequent haul-out sites, hindering generation of abundance data required to estimate population size. A recent tag-recapture study used photographic identifications of white sharks at two aggregation sites to estimate abundance in "central California" at 219 mature and sub-adult individuals. They concluded this represented approximately one-half of the total abundance of mature and sub-adult sharks in the entire eastern North Pacific Ocean (ENP). This low estimate generated great concern within the conservation community, prompting petitions for governmental endangered species designations. We critically examine that study and find violations of model assumptions that, when considered in total, lead to population underestimates. We also use a Bayesian mixture model to demonstrate that the inclusion of transient sharks, characteristic of white shark aggregation sites, would substantially increase abundance estimates for the adults and sub-adults in the surveyed sub-population. Using a dataset obtained from the same sampling locations and widely accepted demographic methodology, our analysis indicates a minimum all-life stages population size of >2000 individuals in the California subpopulation is required to account for the number and size range of individual sharks observed at the two sampled sites. Even accounting for methodological and conceptual biases, an extrapolation of these data to estimate the white shark population size throughout the ENP is inappropriate. The true ENP white shark population size is likely several-fold greater as both our study and the original published estimate exclude non-aggregating sharks and those that independently aggregate at other important ENP sites. Accurately estimating the central California and ENP white shark population size requires methodologies that account for biases introduced by sampling a limited number of sites and that account for all life history stages across the species' range of habitats.

Development of a Laser Probe for Argon Isotope Studies.

NASA Astrophysics Data System (ADS)

McConville, Paul

Available from UMI in association with The British Library. The first objective of this study was to develop a laser outgassing facility for argon isotope studies. Apart from the laser and construction of the laser sample port, existing vacuum and mass spectrometer systems were used. Laser performance and optimum operating conditions were investigated. The second objective was test and evaluate the laser extraction technique by studies of simple geological samples. Previous laser ^{40} Ar-^{39}Ar dating studies by other workers had not systematically established the basis or characteristics of the method. Results from laser and complementary stepped heating studies of the ^{40}Ar-^ {39}Ar dating standard hornblende, hb3gr; a phlogopite sample from the Palabora (Phalaborwa) Complex; and biotites in a thin section of the Hamlet Bjerg granite from East Greenland, verified that: (1) Laser extraction reproduced within experimental error the stepped heating ^{40}Ar-^ {39}Ar and K-Ar ages of simple samples. (2) The precision of the technique i.e. the amount of sample required to give reliable ages, was limited in the present experiments largely by the level of the blanks and backgrounds to 10-100 ug samples. (3) Sample outgassing appeared to be limited to the order of 10 um outside the physical size of the laser pit, consistent with other estimates of the spatial definition in the literature. This could be understood by thermal diffusion and the length of the laser pulse. (4) The efficiency of the laser pulse in melting and outgassing mineral samples was shown to be dependent on silicate latent heats and mineral absorption at the laser wavelength. In addition, the ^{40} Ar-^{39}Ar age of the geologically significant Palabora Complex was determined as (2053 +/- 5) Ma. Excess argon led to a discrepancy between the laser and stepped heating ages of biotite and muscovite, (405 +/- 5) Ma, and laser ages of feldspars (510 +/- 20) Ma in the Hamlet Bjerg granite. This illustrated one advantage of in situ laser age determinations on mineral grains in thin section. (Abstract shortened by UMI.).

Sex differences in visual-spatial working memory: A meta-analysis.

PubMed

Voyer, Daniel; Voyer, Susan D; Saint-Aubin, Jean

2017-04-01

Visual-spatial working memory measures are widely used in clinical and experimental settings. Furthermore, it has been argued that the male advantage in spatial abilities can be explained by a sex difference in visual-spatial working memory. Therefore, sex differences in visual-spatial working memory have important implication for research, theory, and practice, but they have yet to be quantified. The present meta-analysis quantified the magnitude of sex differences in visual-spatial working memory and examined variables that might moderate them. The analysis used a set of 180 effect sizes from healthy males and females drawn from 98 samples ranging in mean age from 3 to 86 years. Multilevel meta-analysis was used on the overall data set to account for non-independent effect sizes. The data also were analyzed in separate task subgroups by means of multilevel and mixed-effects models. Results showed a small but significant male advantage (mean d = 0.155, 95 % confidence interval = 0.087-0.223). All the tasks produced a male advantage, except for memory for location, where a female advantage emerged. Age of the participants was a significant moderator, indicating that sex differences in visual-spatial working memory appeared first in the 13-17 years age group. Removing memory for location tasks from the sample affected the pattern of significant moderators. The present results indicate a male advantage in visual-spatial working memory, although age and specific task modulate the magnitude and direction of the effects. Implications for clinical applications, cognitive model building, and experimental research are discussed.

Genealogies and ages of cultural traits: An application of the theory of duality to the research on cultural evolution.

PubMed

Kobayashi, Yutaka; Wakano, Joe Yuichiro; Ohtsuki, Hisashi

2018-05-09

A finite-population, discrete-generation model of cultural evolution is described, in which multiple discrete traits are transmitted independently. In this model, each newborn may inherit a trait from multiple cultural parents. Transmission fails with a positive probability unlike in population genetics. An ancestral process simulating the cultural genealogy of a sample of individuals is derived for this model. This ancestral process, denoted by M - , is shown to be dual to a process M + describing the change in the frequency of a trait. The age-frequency spectrum is defined as a two-dimensional array whose (i,k) element is the expected number of distinct cultural traits introduced k generations ago and now carried by i individuals in a sample of a particular size n. Numerical calculations reveal that the age-frequency spectrum and related metrics undergo a critical transition from a phase with a moderate number of young, rare traits to a phase with numerous very old, common traits when the expected number of cultural parents per individual exceeds one. It is shown that M + and M - converge to branching or deterministic processes, depending on the way population size tends to infinity, and these limiting processes bear some duality relationships. The critical behavior of the original processes M + and M - is explained in terms of a phase transition of the branching processes. Using the results of the limiting processes in combination, we derive analytical formulae that well approximate the age-frequency spectrum and also other metrics. Copyright © 2018 Elsevier Inc. All rights reserved.

Systematic review of proposed definitions of nocturnal polyuria and population-based evidence of their diagnostic accuracy.

PubMed

Olesen, Tine Kold; Denys, Marie-Astrid; Vande Walle, Johan; Everaert, Karel

2018-02-06

Background Evidence of diagnostic accuracy for proposed definitions of nocturnal polyuria is currently unclear. Purpose Systematic review to determine population-based evidence of the diagnostic accuracy of proposed definitions of nocturnal polyuria based on data from frequency-volume charts. Methods Seventeen pre-specified search terms identified 351 unique investigations published from 1990 to 2016 in BIOSIS, Embase, Embase Alerts, International Pharmaceutical Abstract, Medline, and Cochrane. Thirteen original communications were included in this review based on pre-specified exclusion criteria. Data were extracted from each paper regarding subject age, sex, ethnicity, health status, sample size, data collection methods, and diagnostic discrimination of proposed definitions including sensitivity, specificity, positive and negative predictive value. Results The sample size of study cohorts, participant age, sex, ethnicity, and health status varied considerably in 13 studies reporting on the diagnostic performance of seven different definitions of nocturnal polyuria using frequency-volume chart data from 4968 participants. Most study cohorts were small, mono-ethnic, including only Caucasian males aged 50 or higher with primary or secondary polyuria that were compared to a control group of healthy men without nocturia in prospective or retrospective settings. Proposed definitions had poor discriminatory accuracy in evaluations based on data from subjects independent from the original study cohorts with findings being similar regarding the most widely evaluated definition endorsed by ICS. Conclusions Diagnostic performance characteristics for proposed definitions of nocturnal polyuria show poor to modest discrimination and are not based on sufficient level of evidence from representative, multi-ethnic population-based data from both females and males of all adult ages.

Natural age dispersion arising from the analysis of broken crystals. Part I: Theoretical basis and implications for the apatite (U-Th)/He thermochronometer

NASA Astrophysics Data System (ADS)

Brown, Roderick W.; Beucher, Romain; Roper, Steven; Persano, Cristina; Stuart, Fin; Fitzgerald, Paul

2013-12-01

Over the last decade major progress has been made in developing both the theoretical and practical aspects of apatite (U-Th)/He thermochronometry and it is now standard practice, and generally seen as best practice, to analyse single grain aliquots. These individual prismatic crystals are often broken and are fragments of larger crystals that have broken during mineral separation along the weak basal cleavage in apatite. This is clearly indicated by the common occurrence of only 1 or no clear crystal terminations present on separated apatite grains, and evidence of freshly broken ends when grains are viewed using a scanning electron microscope. This matters because if the 4He distribution within the whole grain is not homogeneous, because of partial loss due to thermal diffusion for example, then the fragments will all yield ages different from each other and from the whole grain age. Here we use a numerical model with a finite cylinder geometry to approximate 4He ingrowth and thermal diffusion within hexagonal prismatic apatite crystals. This is used to quantify the amount and patterns of inherent, natural age dispersion that arises from analysing broken crystals. A series of systematic numerical experiments were conducted to explore and quantify the pattern and behaviour of this source of dispersion using a set of 5 simple thermal histories that represent a range of plausible geological scenarios. In addition some more complex numerical experiments were run to investigate the pattern and behaviour of grain dispersion seen in several real data sets. The results indicate that natural dispersion of a set of single fragment ages (defined as the range divided by the mean) arising from fragmentation alone varies from c. 7% even for rapid (c. 10 °C/Ma), monotonic cooling to over 50% for protracted, complex histories that cause significant diffusional loss of 4He. The magnitude of dispersion arising from fragmentation scales with the grain cylindrical radius, and is of a similar magnitude to dispersion expected from differences in absolute grain size alone (spherical equivalent radii of 40-150 μm). This source of dispersion is significant compared with typical analytical uncertainties on individual grain analyses (c. 6%) and standard deviations on multiple grain analyses from a single sample (c. 10-20%). Where there is a significant difference in the U and Th concentration of individual grains (eU), the effect of radiation damage accumulation on 4He diffusivity (assessed using the RDAAM model of Flowers et al. (2009)) is the primary cause of dispersion for samples that have experienced a protracted thermal history, and can cause dispersion in excess of 100% for realistic ranges of eU concentration (i.e. 5-100 ppm). Expected natural dispersion arising from the combined effects of reasonable variations in grain size (radii 40-125 μm), eU concentration (5-150 ppm) and fragmentation would typically exceed 100% for complex thermal histories. In addition to adding a significant component of natural dispersion to analyses, the effect of fragmentation also acts to decouple and corrupt expected correlations between grain ages and absolute grain size and to a lesser extent between grain age and effective uranium concentration (eU). Considering fragmentation explicitly as a source of dispersion and analysing how the different sources of natural dispersion all interact with each other provides a quantitative framework for understanding patterns of dispersion that otherwise appear chaotic. An important outcome of these numerical experiments is that they demonstrate that the pattern of age dispersion arising from fragmentation mimics the pattern of 4He distribution within the whole grains, thus providing an important source of information about the thermal history of the sample. We suggest that if the primary focus of a study is to extract the thermal history information from (U-Th)/He analyses then sampling and analytical strategies should aim to maximise the natural dispersion of grain ages, not minimise it, and should aim to analyse circa 20-30 grains from each sample. The key observations and conclusions drawn here are directly applicable to other thermochronometers, such as the apatite, rutile and titanite U-Pb systems, where the diffusion domain is approximated by the physical grain size.

Age, growth and fall diet of channel catfish in Cheat Lake, West Virginia

USGS Publications Warehouse

Hilling, Corbin D.; Welsh, Stuart A.; Smith, Dustin M.

2016-01-01

Acidification has historically impaired Cheat Lake's fish community, but recent mitigation efforts within the Cheat River watershed have improved water quality and species richness. Presently, channel catfish Ictalurus punctatus are abundant and attain desirable sizes for anglers. We evaluated the age, growth, and fall diet of the population. We collected a sample of 155 channel catfish from Cheat Lake from 5 August to 4 December 2014, a subset of which we aged (n = 148) using lapillus otoliths. We fit four growth models (von Bertalanffy, logistic, Gompertz, and power) to length-at-age data and compared models using an information theoretic approach. We collected fall diets from 55 fish sampled from 13 October to 4 December 2014. Total lengths of individuals in the sample ranged from 154 to 721 mm and ages ranged from 2 to 19 y. We AICc-selected the von Bertalanffy growth model as the best approximating model, and the power and Gompertz models also had considerable support. Diets were numerically dominated by Diptera larvae, specifically Chironomidae and Chaoboridae, while 39% of stomachs contained terrestrial food items. This study provides baseline data for management of Cheat Lake's channel catfish population. Further, this study fills a knowledge gap in the scientific literature on channel catfish, because few previously published studies have examined the population ecology of channel catfish in the Central Appalachian region.

Protection of obstetric dimensions in a small-bodied human sample.

PubMed

Kurki, Helen K

2007-08-01

In human females, the bony pelvis must find a balance between being small (narrow) for efficient bipedal locomotion, and being large to accommodate a relatively large newborn. It has been shown that within a given population, taller/larger-bodied women have larger pelvic canals. This study investigates whether in a population where small body size is the norm, pelvic geometry (size and shape), on average, shows accommodation to protect the obstetric canal. Osteometric data were collected from the pelves, femora, and clavicles (body size indicators) of adult skeletons representing a range of adult body size. Samples include Holocene Later Stone Age (LSA) foragers from southern Africa (n = 28 females, 31 males), Portuguese from the Coimbra-identified skeletal collection (CISC) (n = 40 females, 40 males) and European-Americans from the Hamann-Todd osteological collection (H-T) (n = 40 females, 40 males). Patterns of sexual dimorphism are similar in the samples. Univariate and multivariate analyses of raw and Mosimann shape-variables indicate that compared to the CISC and H-T females, the LSA females have relatively large midplane and outlet canal planes (particularly posterior and A-P lengths). The LSA males also follow this pattern, although with absolutely smaller pelves in multivariate space. The CISC females, who have equally small stature, but larger body mass, do not show the same type of pelvic canal size and shape accommodation. The results suggest that adaptive allometric modeling in at least some small-bodied populations protects the obstetric canal. These findings support the use of population-specific attributes in the clinical evaluation of obstetric risk. (c) 2007 Wiley-Liss, Inc.

Steep discounting of delayed monetary and food rewards in obesity: a meta-analysis.

PubMed

Amlung, M; Petker, T; Jackson, J; Balodis, I; MacKillop, J

2016-08-01

An increasing number of studies have investigated delay discounting (DD) in relation to obesity, but with mixed findings. This meta-analysis synthesized the literature on the relationship between monetary and food DD and obesity, with three objectives: (1) to characterize the relationship between DD and obesity in both case-control comparisons and continuous designs; (2) to examine potential moderators, including case-control v. continuous design, money v. food rewards, sample sex distribution, and sample age (18 years); and (3) to evaluate publication bias. From 134 candidate articles, 39 independent investigations yielded 29 case-control and 30 continuous comparisons (total n = 10 278). Random-effects meta-analysis was conducted using Cohen's d as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger tests, meta-regression of publication year and effect size, and imputation of missing studies. The primary analysis revealed a medium effect size across studies that was highly statistically significant (d = 0.43, p < 10-14). None of the moderators examined yielded statistically significant differences, although notably larger effect sizes were found for studies with case-control designs, food rewards and child/adolescent samples. Limited evidence of publication bias was present, although the Begg-Mazumdar test and meta-regression suggested a slightly diminishing effect size over time. Steep DD of food and money appears to be a robust feature of obesity that is relatively consistent across the DD assessment methodologies and study designs examined. These findings are discussed in the context of research on DD in drug addiction, the neural bases of DD in obesity, and potential clinical applications.

Optical properties of mineral dust aerosol including analysis of particle size, composition, and shape effects, and the impact of physical and chemical processing

NASA Astrophysics Data System (ADS)

Alexander, Jennifer Mary

Atmospheric mineral dust has a large impact on the earth's radiation balance and climate. The radiative effects of mineral dust depend on factors including, particle size, shape, and composition which can all be extremely complex. Mineral dust particles are typically irregular in shape and can include sharp edges, voids, and fine scale surface roughness. Particle shape can also depend on the type of mineral and can vary as a function of particle size. In addition, atmospheric mineral dust is a complex mixture of different minerals as well as other, possibly organic, components that have been mixed in while these particles are suspended in the atmosphere. Aerosol optical properties are investigated in this work, including studies of the effect of particle size, shape, and composition on the infrared (IR) extinction and visible scattering properties in order to achieve more accurate modeling methods. Studies of particle shape effects on dust optical properties for single component mineral samples of silicate clay and diatomaceous earth are carried out here first. Experimental measurements are modeled using T-matrix theory in a uniform spheroid approximation. Previous efforts to simulate the measured optical properties of silicate clay, using models that assumed particle shape was independent of particle size, have achieved only limited success. However, a model which accounts for a correlation between particle size and shape for the silicate clays offers a large improvement over earlier modeling approaches. Diatomaceous earth is also studied as an example of a single component mineral dust aerosol with extreme particle shapes. A particle shape distribution, determined by fitting the experimental IR extinction data, used as a basis for modeling the visible light scattering properties. While the visible simulations show only modestly good agreement with the scattering data, the fits are generally better than those obtained using more commonly invoked particle shape distributions. The next goal of this work is to investigate if modeling methods developed in the studies of single mineral components can be generalized to predict the optical properties of more authentic aerosol samples which are complex mixtures of different minerals. Samples of Saharan sand, Iowa loess, and Arizona road dust are used here as test cases. T-matrix based simulations of the authentic samples, using measured particle size distributions, empirical mineralogies, and a priori particle shape models for each mineral component are directly compared with the measured IR extinction spectra and visible scattering profiles. This modeling approach offers a significant improvement over more commonly applied models that ignore variations in particle shape with size or mineralogy and include only a moderate range of shape parameters. Mineral dust samples processed with organic acids and humic material are also studied in order to explore how the optical properties of dust can change after being aged in the atmosphere. Processed samples include quartz mixed with humic material, and calcite reacted with acetic and oxalic acid. Clear differences in the light scattering properties are observed for all three processed mineral dust samples when compared to the unprocessed mineral dust or organic salt products. These interactions result in both internal and external mixtures depending on the sample. In addition, the presence of these organic materials can alter the mineral dust particle shape. Overall, however, these results demonstrate the need to account for the effects of atmospheric aging of mineral dust on aerosol optical properties. Particle shape can also affect the aerodynamic properties of mineral dust aerosol. In order to account for these effects, the dynamic shape factor is used to give a measure of particle asphericity. Dynamic shape factors of quartz are measured by mass and mobility selecting particles and measuring their vacuum aerodynamic diameter. From this, dynamic shape factors in both the transition and vacuum regime can be derived. The measured dynamic shape factors of quartz agree quite well with the spheroidal shape distributions derived through studies of the optical properties.

Identification of missing variants by combining multiple analytic pipelines.

PubMed

Ren, Yingxue; Reddy, Joseph S; Pottier, Cyril; Sarangi, Vivekananda; Tian, Shulan; Sinnwell, Jason P; McDonnell, Shannon K; Biernacka, Joanna M; Carrasquillo, Minerva M; Ross, Owen A; Ertekin-Taner, Nilüfer; Rademakers, Rosa; Hudson, Matthew; Mainzer, Liudmila Sergeevna; Asmann, Yan W

2018-04-16

After decades of identifying risk factors using array-based genome-wide association studies (GWAS), genetic research of complex diseases has shifted to sequencing-based rare variants discovery. This requires large sample sizes for statistical power and has brought up questions about whether the current variant calling practices are adequate for large cohorts. It is well-known that there are discrepancies between variants called by different pipelines, and that using a single pipeline always misses true variants exclusively identifiable by other pipelines. Nonetheless, it is common practice today to call variants by one pipeline due to computational cost and assume that false negative calls are a small percent of total. We analyzed 10,000 exomes from the Alzheimer's Disease Sequencing Project (ADSP) using multiple analytic pipelines consisting of different read aligners and variant calling strategies. We compared variants identified by using two aligners in 50,100, 200, 500, 1000, and 1952 samples; and compared variants identified by adding single-sample genotyping to the default multi-sample joint genotyping in 50,100, 500, 2000, 5000 and 10,000 samples. We found that using a single pipeline missed increasing numbers of high-quality variants correlated with sample sizes. By combining two read aligners and two variant calling strategies, we rescued 30% of pass-QC variants at sample size of 2000, and 56% at 10,000 samples. The rescued variants had higher proportions of low frequency (minor allele frequency [MAF] 1-5%) and rare (MAF < 1%) variants, which are the very type of variants of interest. In 660 Alzheimer's disease cases with earlier onset ages of ≤65, 4 out of 13 (31%) previously-published rare pathogenic and protective mutations in APP, PSEN1, and PSEN2 genes were undetected by the default one-pipeline approach but recovered by the multi-pipeline approach. Identification of the complete variant set from sequencing data is the prerequisite of genetic association analyses. The current analytic practice of calling genetic variants from sequencing data using a single bioinformatics pipeline is no longer adequate with the increasingly large projects. The number and percentage of quality variants that passed quality filters but are missed by the one-pipeline approach rapidly increased with sample size.

Executive and Reward-Related Function in Pediatric Obesity: A Meta-Analysis.

PubMed

Pearce, Alaina L; Leonhardt, Christine A; Vaidya, Chandan J

2018-06-06

This study examined the effect of pediatric obesity on executive function and reward-related decision-making, cognitive processes that are relevant to obesogenic behaviors, and evaluated their association with sample (e.g., age, gender, intelligence, and socioeconomic status, SES) and study/task (e.g., categorical/continuous variable, food stimuli) characteristics. A random-effects meta-analysis was conducted using Hedge's g effect sizes of published studies from 1960 to 2016, limited to children younger than the age of 21 years without medical comorbidities. Analysis included estimation of heterogeneity (τ 2 ), publication bias (funnel-plot symmetry and fail-safe N), and sensitivity analyses for sample and study/task characteristics. Across 68 studies with 70 samples, obesity was associated with worse functioning overall (-0.24; 95CI: -0.30 to -0.19; p < 0.001) and for each component process (attention, switching, inhibition, interference, working memory, reward, delay of gratification: -0.19 to -0.38; p's < 0.017), except trait impulsivity (-0.06; 95CI: -0.18 to 0.07). Deficits increased with age and female composition of the sample for inhibition (p = 0.002). No other characteristics moderated effect of obesity. Small-to-moderate negative associations with obesity were observed for executive and reward-related performance, but not on reported impulsivity in studies with children younger than the age of 21 years. These results were not moderated by IQ, SES, and study/task characteristics. Age and gender moderated association with inhibition, with a larger obesity-related deficit in older and predominantly female samples. These results suggest cognitive and demographic intervention targets for prevention and mitigation of obesogenic behavior.

The prevalence of domestic violence within different socio-economic classes in Central Trinidad.

PubMed

Nagassar, R P; Rawlins, J M; Sampson, N R; Zackerali, J; Chankadyal, K; Ramasir, C; Boodram, R

2010-01-01

Domestic violence is a medical and social issue that often leads to negative consequences for society. This paper examines the association between the prevalence of domestic violence in relation to the different socio-economic classes in Central Trinidad. The paper also explores the major perceived causes of physical abuse in Central Trinidad. Participants were selected using a two-stage stratified sampling method within the Couva district. Households, each contributing one participant, were stratified into different socioeconomic classes (SES Class) and each stratum size (or its share in the sample) was determined by the portion of its size in the sampling frame to the total sample; then its members were randomly selected. The sampling method attempted to balance and then minimize racial, age, cultural biases and confounding factors. The participant chosen had to be older than 16-years of age, female and a resident of the household. If more than one female was at home, the most senior was interviewed. The study found a statistically significant relationship between verbal abuse (p = 0.0017), physical abuse (p = 0.0012) and financial abuse (p = 0.001) and socio-economic class. For all the socio-economic classes considered, the highest prevalence of domestic violence occurred amongst the working class and lower middle socio-economic classes. The most prominent reasons cited for the physical violence was drug and alcohol abuse (37%) and communication differences (16.3%). These were the other two main perceived causes of the violence. The power of the study was 0.78 and the all strata prevalence of domestic violence was 41%. Domestic violence was reported within all socio-economic class groupings but it was most prevalent within the working class and lower middle socio-economic classes. The major perceived cause of domestic violence was alcohol/drug abuse.

A cross sectional study on factors associated with harmful traditional practices among children less than 5 years in Axum town, north Ethiopia, 2013

PubMed Central

2014-01-01

Background Every social grouping in the world has its own cultural practices and beliefs which guide its members on how they should live or behave. Harmful traditional practices that affect children are Female genital mutilation, Milk teeth extraction, Food taboo, Uvula cutting, keeping babies out of exposure to sun, and Feeding fresh butter to new born babies. The objective of this study was to assess factors associated with harmful traditional practices among children less than 5 years of age in Axum town, North Ethiopia. Methods Community based cross sectional study was conducted in 752 participants who were selected using multi stage sampling; Simple random sampling method was used to select ketenas from all kebelles of Axum town. After proportional allocation of sample size, systematic random sampling method was used to get the study participants. Data was collected using interviewer administered Tigrigna version questionnaire, it was entered and analyzed using SPSS version 16. Descriptive statistics was calculated and logistic regressions were used to analyze the data. Results Out of the total sample size 50.7% children were females, the mean age of children was 26.28 months and majority of mothers had no formal education. About 87.8% mothers had performed at least one traditional practice to their children; uvula cutting was practiced on 86.9% children followed by milk teeth extraction 12.5% and eye borrows incision 2.4% children. Fear of swelling, pus and rapture of the uvula was the main reason to perform uvula cutting. Conclusion The factors associated with harmful traditional practices were educational status, occupation, religion of mothers and harmful traditional practices performed on the mothers. PMID:24952584

A cross sectional study on factors associated with harmful traditional practices among children less than 5 years in Axum town, north Ethiopia, 2013.

PubMed

Gebrekirstos, Kahsu; Abebe, Mesfin; Fantahun, Atsede

2014-06-21

Every social grouping in the world has its own cultural practices and beliefs which guide its members on how they should live or behave. Harmful traditional practices that affect children are Female genital mutilation, Milk teeth extraction, Food taboo, Uvula cutting, keeping babies out of exposure to sun, and Feeding fresh butter to new born babies. The objective of this study was to assess factors associated with harmful traditional practices among children less than 5 years of age in Axum town, North Ethiopia. Community based cross sectional study was conducted in 752 participants who were selected using multi stage sampling; Simple random sampling method was used to select ketenas from all kebelles of Axum town. After proportional allocation of sample size, systematic random sampling method was used to get the study participants. Data was collected using interviewer administered Tigrigna version questionnaire, it was entered and analyzed using SPSS version 16. Descriptive statistics was calculated and logistic regressions were used to analyze the data. Out of the total sample size 50.7% children were females, the mean age of children was 26.28 months and majority of mothers had no formal education. About 87.8% mothers had performed at least one traditional practice to their children; uvula cutting was practiced on 86.9% children followed by milk teeth extraction 12.5% and eye borrows incision 2.4% children. Fear of swelling, pus and rapture of the uvula was the main reason to perform uvula cutting. The factors associated with harmful traditional practices were educational status, occupation, religion of mothers and harmful traditional practices performed on the mothers.

Sample Design, Sample Augmentation, and Estimation for Wave 2 of the NSHAP

PubMed Central

English, Ned; Pedlow, Steven; Kwok, Peter K.

2014-01-01

Objectives. The sample for the second wave (2010) of National Social Life, Health, and Aging Project (NSHAP) was designed to increase the scientific value of the Wave 1 (2005) data set by revisiting sample members 5 years after their initial interviews and augmenting this sample where possible. Method. There were 2 important innovations. First, the scope of the study was expanded by collecting data from coresident spouses or romantic partners. Second, to maximize the representativeness of the Wave 2 data, nonrespondents from Wave 1 were again approached for interview in the Wave 2 sample. Results. The overall unconditional response rate for the Wave 2 panel was 74%; the conditional response rate of Wave 1 respondents was 89%; the conditional response rate of partners was 84%; and the conversion rate for Wave 1 nonrespondents was 26%. Discussion. The inclusion of coresident partners enhanced the study by allowing the examination of how intimate, household relationships are related to health trajectories and by augmenting the size of the NSHAP sample size for this and future waves. The uncommon strategy of returning to Wave 1 nonrespondents reduced potential bias by ensuring that to the extent possible the whole of the original sample forms the basis for the field effort. NSHAP Wave 2 achieved its field objectives of consolidating the panel, recruiting their resident spouses or romantic partners, and converting a significant proportion of Wave 1 nonrespondents. PMID:25360016

The influence of birth size on intelligence in healthy children.

PubMed

Broekman, Birit F P; Chan, Yiong-Huak; Chong, Yap-Seng; Quek, Swee-Chye; Fung, Daniel; Low, Yen-Ling; Ooi, Yoon-Phaik; Gluckman, Peter D; Meaney, Michael J; Wong, Tien-Yin; Saw, Seang-Mei

2009-06-01

Birth parameters have been hypothesized to have an influence on IQ. However, studies within the range of normal birth size have been sparse. With this study we examined the associations between birth length, birth weight, head circumference, and gestational age within the normal birth size range in relation to childhood IQ in Asian children. A cohort of 1979 of 2913 Asian children aged 7 to 9 years, recruited from 3 schools in Singapore, were followed yearly from 1999 onward. Birth parameters were recorded by health personnel. Childhood IQ was measured with the Raven's Standard Progressive Matrices at ages 8 to 12. The mean IQ score across the sample (n = 1645) was 114.2. After controlling for multiple confounders for every 1-cm increment in birth length, 1 kg in birth weight, or 1 cm in head circumference, there was a corresponding increase in IQ of 0.49 points (P for trend < .001), 2.19 points (P for trend = .007) and .62 points (P for trend = .003), respectively. These associations persisted even after exclusion of premature children and children with extreme weights and head circumferences. Longer birth length, higher birth weight, or larger head circumferences within the normal birth size range are associated with higher IQ scores in Asian children. Our results suggest that antenatal factors reflected in altered rates of growth but within the normative range of pregnancy experiences play a role in generating cognitive potential. This has implications for targeting early intervention and preventative programs.

Using an integral projection model to assess the effect of temperature on the growth of gilthead seabream Sparus aurata.

PubMed

Heather, F J; Childs, D Z; Darnaude, A M; Blanchard, J L

2018-01-01

Accurate information on the growth rates of fish is crucial for fisheries stock assessment and management. Empirical life history parameters (von Bertalanffy growth) are widely fitted to cross-sectional size-at-age data sampled from fish populations. This method often assumes that environmental factors affecting growth remain constant over time. The current study utilized longitudinal life history information contained in otoliths from 412 juveniles and adults of gilthead seabream, Sparus aurata, a commercially important species fished and farmed throughout the Mediterranean. Historical annual growth rates over 11 consecutive years (2002-2012) in the Gulf of Lions (NW Mediterranean) were reconstructed to investigate the effect of temperature variations on the annual growth of this fish. S. aurata growth was modelled linearly as the relationship between otolith size at year t against otolith size at the previous year t-1. The effect of temperature on growth was modelled with linear mixed effects models and a simplified linear model to be implemented in a cohort Integral Projection Model (cIPM). The cIPM was used to project S. aurata growth, year to year, under different temperature scenarios. Our results determined current increasing summer temperatures to have a negative effect on S. aurata annual growth in the Gulf of Lions. They suggest that global warming already has and will further have a significant impact on S. aurata size-at-age, with important implications for age-structured stock assessments and reference points used in fisheries.

230Th-U dating of surficial deposits using the ion microprobe (SHRIMP-RG): A microstratigraphic perspective

USGS Publications Warehouse

Maher, K.; Wooden, J.L.; Paces, J.B.; Miller, D.M.

2007-01-01

We used the sensitive high-resolution ion microprobe reverse-geometry (SHRIMP-RG) to date pedogenic opal using the 230Th-U system. Due to the high-spatial resolution of an ion microprobe (typically 30 ??m), regions of pure opal within a sample can be targeted and detrital material can be avoided. In addition, because the technique is non-destructive, the sample can be preserved for other types of analyses including electron microprobe or other stable isotope or trace element ion microprobe measurements. The technique is limited to material with U concentrations greater than ???50 ppm. However, the high spatial resolution, small sample requirements, and the ability to avoid detrital material make this technique a suitable technique for dating many Pleistocene deposits formed in semi-arid environments. To determine the versatility of the method, samples from several different deposits were analyzed, including silica-rich pebble coatings from pedogenic carbonate horizons, a siliceous sinter deposit, and opaline silica deposited as a spring mound. U concentrations for 30-??m-diameter spots ranged from 50 to 1000 ppm in these types of materials. The 230Th/232Th activity ratios also ranged from ???100 to 106, eliminating the need for detrital Th corrections that reduce the precision of traditional U-Th ages for many milligram- and larger-sized samples. In pedogenic material, layers of high-U opal (ca. 500 ppm) are commonly juxtaposed next to layers of calcite with much lower U concentrations (1-2 ppm). If these types of samples are not analyzed using a technique with the appropriate spatial resolution, the ages may be strongly biased towards the age of the opal. Comparison with standard TIMS (Thermal Ionization Mass Spectrometry) measurements from separate microdrilled samples suggests that although the analytical precision of the ion microprobe (SHRIMP-RG) measurements is less than TIMS, the high spatial resolution results in better accuracy in the age determination for finely layered or complex deposits. The ion microprobe approach also may be useful for pre-screening samples to determine the age and degree of post-depositional alteration, analyzing finely layered samples or samples with complex growth histories, and obtaining simultaneous measurements of trace elements.

Characterization of helium diffusion behavior from continuous heating experiments: Sample screening and identification of multiple 4He components

NASA Astrophysics Data System (ADS)

McDannell, K. T.; Idleman, B. D.; Zeitler, P. K.

2015-12-01

Old, slowly cooled apatites often yield overdispersed helium ages due to factors such as parent zonation, He implantation, radiation damage, crystal defects, and fluid inclusions. Careful mineral selection and many replicate analyses can mitigate the impact of some of these effects. However, this approach adds unnecessary costs in time and resources when dating well-behaved apatites and is generally ineffective at identifying the root cause of age dispersion and providing suitable age corrections for poorly behaved samples. We assess a new technique utilizing static-gas measurement during continuous heating as a means to rapidly screen apatite samples. In about the time required for a conventional total-gas analysis, this method can discriminate between samples showing the volume-diffusion behavior expected for apatite and those showing anomalous release patterns, inconsistent with their use in thermochronologic applications. This method may also have the potential to quantify and discriminate between the radiogenic and extraneous 4He fractions released by a sample. Continuously heated samples that outgas by volume diffusion during a linear heating schedule should produce a characteristic sigmoidal 4He fractional loss profile, with the exact shape and position of these profiles (in loss vs. heating time space) controlled by sample kinetics, grain size, and heating rate. Secondary factors such as sample zoning and alpha-loss distribution have a relatively minor impact on such profiles. Well-behaved examples such as the Durango standard and other apatites with good age reproducibility show the expected smooth, sigmoidal gas release with complete exhaustion by temperatures predicted for volume diffusion using typical apatite kinetics (e.g., by ~900˚C for linear heating at 20˚C/minute). In contrast, "bad actor" samples that do not replicate well show significant degrees of helium release deferred to higher temperatures. We report on screening results for a range of samples including a suite of slowly cooled Cretaceous apatites from the Hangay Dome in central Mongolia, assessing the degree to which screening using cumulative heating can reliably identify bad-actor grains, and possibly, correct their ages.

Vocabulary Knowledge of Children With Cochlear Implants: A Meta-Analysis

PubMed Central

2016-01-01

This article employs meta-analysis procedures to evaluate whether children with cochlear implants demonstrate lower spoken-language vocabulary knowledge than peers with normal hearing. Of the 754 articles screened and 52 articles coded, 12 articles met predetermined inclusion criteria (with an additional 5 included for one analysis). Effect sizes were calculated for relevant studies and forest plots were used to compare differences between groups of children with normal hearing and children with cochlear implants. Weighted effect size averages for expressive vocabulary measures (g = −11.99; p < .001) and for receptive vocabulary measures (g = −20.33; p < .001) indicated that children with cochlear implants demonstrate lower vocabulary knowledge than children with normal hearing. Additional analyses confirmed the value of comparing vocabulary knowledge of children with hearing loss to a tightly matched (e.g., socioeconomic status-matched) sample. Age of implantation, duration of implantation, and chronological age at testing were not significantly related to magnitude of weighted effect size. Findings from this analysis represent a first step toward resolving discrepancies in the vocabulary knowledge literature. PMID:26712811

[Prevalence of high blood pressure in children and adolescents from the city of Maceió, Brazil].

PubMed

Moura, Adriana A; Silva, Maria A M; Ferraz, Maria R M T; Rivera, Ivan R

2004-01-01

To define the prevalence of high blood pressure in a representative sample of children and adolescents from the city of Maceió, state of Alagoas, Brazil, and to investigate the association of high blood pressure with age, sex and nutritional status. This cross-sectional study was carried out from May 2000 to September 2002. Individuals between 7 and 17 years of age were selected among all the 185,702 students from public and private schools. The size of the sample was defined based on the expected prevalence of hypertension for the age group. After randomization, data were collected through a questionnaire. Blood pressure was measured twice. Weight and height were also measured. High blood pressure was defined as systolic and/or diastolic blood pressure over the 95th percentile in one or in both measures. The final sample included 1,253 students (706 females). One hundred and eighteen students had high blood pressure (mean age 13 years; 44% males). Risk of being overweight and excess weight were identified, respectively, in 9.3 and 4.5% of the students. These variables were significantly associated with high blood pressure. The prevalence of high blood pressure was 9.4%. High blood pressure was significantly more frequent among overweight students and among those at risk for being overweight.

Modulation of the age at onset in spinocerebellar ataxia by CAG tracts in various genes

PubMed Central

Durr, Alexandra; Bauer, Peter; Figueroa, Karla P.; Ichikawa, Yaeko; Brussino, Alessandro; Forlani, Sylvie; Rakowicz, Maria; Schöls, Ludger; Mariotti, Caterina; van de Warrenburg, Bart P.C.; Orsi, Laura; Giunti, Paola; Filla, Alessandro; Szymanski, Sandra; Klockgether, Thomas; Berciano, José; Pandolfo, Massimo; Boesch, Sylvia; Melegh, Bela; Timmann, Dagmar; Mandich, Paola; Camuzat, Agnès; Goto, Jun; Ashizawa, Tetsuo; Cazeneuve, Cécile; Tsuji, Shoji; Pulst, Stefan-M.; Brusco, Alfredo; Riess, Olaf; Stevanin, Giovanni

2014-01-01

Polyglutamine-coding (CAG)n repeat expansions in seven different genes cause spinocerebellar ataxias. Although the size of the expansion is negatively correlated with age at onset, it accounts for only 50–70% of its variability. To find other factors involved in this variability, we performed a regression analysis in 1255 affected individuals with identified expansions (spinocerebellar ataxia types 1, 2, 3, 6 and 7), recruited through the European Consortium on Spinocerebellar Ataxias, to determine whether age at onset is influenced by the size of the normal allele in eight causal (CAG)n-containing genes (ATXN1–3, 6–7, 17, ATN1 and HTT). We confirmed the negative effect of the expanded allele and detected threshold effects reflected by a quadratic association between age at onset and CAG size in spinocerebellar ataxia types 1, 3 and 6. We also evidenced an interaction between the expanded and normal alleles in trans in individuals with spinocerebellar ataxia types 1, 6 and 7. Except for individuals with spinocerebellar ataxia type 1, age at onset was also influenced by other (CAG)n-containing genes: ATXN7 in spinocerebellar ataxia type 2; ATXN2, ATN1 and HTT in spinocerebellar ataxia type 3; ATXN1 and ATXN3 in spinocerebellar ataxia type 6; and ATXN3 and TBP in spinocerebellar ataxia type 7. This suggests that there are biological relationships among these genes. The results were partially replicated in four independent populations representing 460 Caucasians and 216 Asian samples; the differences are possibly explained by ethnic or geographical differences. As the variability in age at onset is not completely explained by the effects of the causative and modifier sister genes, other genetic or environmental factors must also play a role in these diseases. PMID:24972706

An overall decline both in recollection and familiarity in healthy aging.

PubMed

Pitarque, Alfonso; Sales, Alicia; Meléndez, Juan C; Mayordomo, Teresa; Satorres, Encar

2015-01-01

In the area of recognition memory, the experimental data have been inconsistent about whether or not familiarity declines in healthy aging. A recent meta-analysis concluded that familiarity is impaired when estimated with the remember-know procedure, but not with the process-dissociation procedure. We present an associative recognition experiment with remember-know judgments that allow us to estimate both recollection and familiarity using both procedures in the same task and with the same participants (a sample of healthy older people and another sample of young people). Moreover, we performed a within-subjects manipulation of the type of materials (pairs of words or pairs of pictures), and the repetition or not of the pairs during the study phase. The results show that familiarity, estimated using both estimation procedures, declines significantly with age, although the effect size obtained with the process-dissociation procedure is significantly smaller than the one obtained with the remember-know procedure. Our results show that aging is associated with significant decreases both in recollection and, to a lesser extent, familiarity.

Spatial and mesoscopic fluctuations in glassy dynamics

NASA Astrophysics Data System (ADS)

Chamon, Claudio C.; Cugliandolo, Leticia F.

2004-05-01

One of the striking properties of a glassy system is that many material properties depend on its age, i.e., the time since the system entered its glassy phase. In this this talk we shall review some recent progress (work in collaboration with H. E. Castillo, P. Charbonneau, J. L. Iguain, M. P. Kennett, D. R. Reichman and M. Sellitto) in understanding local aging, through the study of local observable quantities, which reveal that there are spatial heterogeneities and fluctuations in the aging process of macroscopic systems. We show that a number of universal properties are shared by many non-equilibrium systems, both with and without quenched disorder, such as the 3D Edwards-Anderson model and some kinetically constrained non-interacting 2D and 3D spin models, for example. Similar scaling relations are found for mesoscopic sample-to-sample fluctuations of global quantities in small size systems. We discuss how the emergence of a symmetry in aging systems, time-reparametrization invariance, could be responsible for the observed universal behavior of the local and mesoscopic non-equilibrium fluctuations.

Psychometric properties of the Social Phobia and Anxiety Inventory for Children in a Spanish sample.

PubMed

Olivares, José; Sánchez-García, Raquel; López-Pina, José Antonio; Rosa-Alcázar, Ana Isabel

2010-11-01

The objectives of the present study were to adapt and analyze the factor structure, reliability, and validity of the Social Phobia and Anxiety Inventory for Children (SPAI-C; Beidel, Turner, & Morris, 1995) in a Spanish population. The SPAI-C was applied to a sample of 1588 children and adolescents with ages ranging from 10 to 17 years. The confirmatory factor analysis (CFA) showed a four-factor structure: Public performance, Assertiveness, Fear and avoidance/escape in social encounters, and Cognitive and psychophysiological interferences. Internal consistency was high (.90) and test-retest reliability was moderate (.56). Significant differences were found in the variables sex and age, although the effect size was small in both variables and their interaction. Overall, the increase of the age value was inversely proportional to that of social anxiety measured with the SPAI-C; in participants of the same age, values were higher for girls than for boys. Results suggest that the Social Phobia and Anxiety Inventory For Children is a valid and reliable instrument to assess social anxiety in Spanish children and adolescents.

Episodic memory and executive functioning in currently depressed patients compared to healthy controls.

PubMed

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

2015-01-01

At present, little is still known about the link between depression, memory and executive functioning. This study examined whether there are memory-related impairments in depressed patients and whether the size of such deficits depends on the age group and on specific types of cognitive measures. Memory performances of 215 clinically depressed patients were compared to the data of a matched control sample. Regression analyses were performed to determine the extent to which executive dysfunctions contributed to episodic memory impairments. When compared with healthy controls, significantly lower episodic memory and executive functioning performances were found for depressed patients of all age groups. Effect sizes appeared to vary across different memory and executive functioning measures. The extent to which executive dysfunctions could explain episodic memory impairments varied depending on the type of measure examined. These findings emphasise the need to consider memory-related functioning of depressed patients in the context of therapeutic treatments.

Sex differences in the adolescent brain and body: Findings from the saguenay youth study.

PubMed

Paus, Tomáš; Wong, Angelita Pui-Yee; Syme, Catriona; Pausova, Zdenka

2017-01-02

This Mini-Review describes sex differences in 66 quantitative characteristics of the brain and body measured in a community-based sample of 1,024 adolescents 12-18 years of age, members of the Saguenay Youth Study. Using an extensive phenotyping protocol, we have obtained measures in a number of domains, including brain structure, cognition, mental health, substance use, body composition, metabolism, cardiovascular reactivity, and life style. For each measure, we provide estimates of effect size (Cohen's d) and sex-specific correlations with age (Pearson R). In total 59 of the 66 characteristics showed sex differences (at a nominal P < 0.05), with small (32), medium-sized (13), and large (11) effects. Some, but not all, of these sex differences increase during adolescence; this appears to be the case mostly for anatomical and physiological measures. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A longitudinal examination of factors associated with social support satisfaction among HIV-positive young Black men who have sex with men.

PubMed

McCullagh, Charlotte; Quinn, Katherine; Voisin, Dexter R; Schneider, John

2017-12-01

This study examined the long-term predictors of social support satisfaction among HIV-positive young Black men who have sex with men (YBMSM). Data were collected across three waves between October 2012 and November 2014 as part of the baseline assessment from Project nGage, a preliminary efficacy randomized control study examining the role of social support in improving HIV care among YBMSM. The sample included 92 YBMSM aged 18-29. Major results controlling for age, education and intervention effects indicated that psychological health, social network size, and education at baseline predicted differences in social support satisfaction at Wave 3, with no significant effects based on length of HIV diagnosis. Therefore, interventions that are intended to promote the quality of life for YBMSM and their engagement and retention in HIV care must focus on their psychological health concerns and network size.

The Violent Early Solar System, as Told by Lunar Sample Geochronology

NASA Astrophysics Data System (ADS)

Cohen, B. A.

2012-12-01

One of the legacies of the samples collected by the Apollo and Luna missions is the link forged between radiometric ages of rocks and relative ages according to stratigraphic relationships and impact crater size-frequency distributions. Our current understanding of the history of the inner solar system is based on the relative chronology of individual planets, tied to the absolute geochronology of the Moon via these important samples. Sample ages have enabled us to infer that impact-melt breccias from Apollo 14 and 15 record the formation of the Imbrium Basin, those from the highland massifs at Apollo 17 record the age of Serenitatis, those from the KREEP-poor Apollo 16 site record the age of Nectaris, and materials from Luna 24 record the age of Crisium. Ejecta from smaller and younger craters Copernicus and Tycho were sampled at Apollo 12 and 17, respectively, and local craters such as Cone at Apollo 14, and North Ray and South Ray at Apollo 16 were also sampled and ages determined for those events. Much of what we understand about the lunar impact flux is based on these ages. Samples from these nearside locations reveal a preponderance of impact-disturbed or recrystallized ages between 3.75 and 3.95 billion years. Argon and lead loss (and correlated disturbances in the Rb-Sr system) have been attributed to metamorphism of the lunar crust by an enormous number of impacts in a brief pulse of time, called the Lunar Cataclysm or Late Heavy Bombardment. Subsequent high-precision geochronometric analyses of Apollo samples and lunar highlands meteorites show a wider range of ages, but very few older than 4 Ga. The paucity of ancient impact melt rocks has been interpreted to mean that either that most impact basins formed at this time, or that ejecta from the large, near-side, young basins dominates the Apollo samples. The impact history of the Moon has significant implications because the lunar bombardment history mirrors that of the Earth. During the cataclysm, 80% of the lunar surface was resurfaced; on Earth, this would scale to ~23,000 large impacts in a brief time. Impact ages in ordinary chondrites, HED meteorites, and the Martian meteorite ALH 84001 suggest that this early bombardment event affected the entire inner solar system. If true, the late heavy bombardment may have directly affected the evolution of life on Earth and our understanding of "habitable" planets. Lunar sample ages have also been used to drive large-scale dynamical modeling of solar system formation. These new models of planetary dynamics show a violent beginning to our solar system, where the late formation or outward migration of the gas giant planets destabilizes the Kuiper belt and main-belt asteroids, sending a cascade of impactors into the Moon and all the inner planets. The existence of an early bombardment has even been postulated in extrasolar planetary systems. Even after 40+ years of study, the provenance of returned lunar samples and ages of key events continue to be a focus of research and a topic of debate. One of the most important lessons learned from Apollo missions is that small samples yield a wealth of information and are gifts that keep on giving. The legacy of Apollo samples serves as a model and impetus for future sample return missions from the Moon, Mars, and asteroids.

The Power of Low Back Pain Trials: A Systematic Review of Power, Sample Size, and Reporting of Sample Size Calculations Over Time, in Trials Published Between 1980 and 2012.

PubMed

Froud, Robert; Rajendran, Dévan; Patel, Shilpa; Bright, Philip; Bjørkli, Tom; Eldridge, Sandra; Buchbinder, Rachelle; Underwood, Martin

2017-06-01

A systematic review of nonspecific low back pain trials published between 1980 and 2012. To explore what proportion of trials have been powered to detect different bands of effect size; whether there is evidence that sample size in low back pain trials has been increasing; what proportion of trial reports include a sample size calculation; and whether likelihood of reporting sample size calculations has increased. Clinical trials should have a sample size sufficient to detect a minimally important difference for a given power and type I error rate. An underpowered trial is one within which probability of type II error is too high. Meta-analyses do not mitigate underpowered trials. Reviewers independently abstracted data on sample size at point of analysis, whether a sample size calculation was reported, and year of publication. Descriptive analyses were used to explore ability to detect effect sizes, and regression analyses to explore the relationship between sample size, or reporting sample size calculations, and time. We included 383 trials. One-third were powered to detect a standardized mean difference of less than 0.5, and 5% were powered to detect less than 0.3. The average sample size was 153 people, which increased only slightly (∼4 people/yr) from 1980 to 2000, and declined slightly (∼4.5 people/yr) from 2005 to 2011 (P < 0.00005). Sample size calculations were reported in 41% of trials. The odds of reporting a sample size calculation (compared to not reporting one) increased until 2005 and then declined (Equation is included in full-text article.). Sample sizes in back pain trials and the reporting of sample size calculations may need to be increased. It may be justifiable to power a trial to detect only large effects in the case of novel interventions. 3.

Prevalence of Traumatic Dental Injuries to the Permanent Anterior Teeth among 9- to 14-year-old Schoolchildren of Navi Mumbai (Kharghar-Belapur Region), India.

PubMed

Hegde, Rahul; Agrawal, Geet

2017-01-01

To measure the prevalence of anterior teeth trauma in 9- to 14-year-old schoolchildren and their association with predisposing factors, such as lip competence, molar relationship, overjet, and variables, such as age, gender, and cause of trauma. Epidemiological cross-sectional study was carried out among 3,012 schoolchildren aged 9 to 14 years in Navi Mumbai (Kharghar-Belapur region). The sample size was derived using the stratified random sampling method; we picked six schools from the region. These schools had 3,000 students in the acceptable age group of the study which constituted our final sample size. All children were examined for traumatic dental injuries, and the children with positive findings were further examined for lip competence, Angle's molar relationship, and overjet. The results were statistically analyzed using cross-tabulation and Chi-square test. The prevalence of dental injuries was 7.3%, and the ratio of male to female children was found to be 1.6:1. The maximum number of traumatic dental injuries was found with class I molar relationship and overjet less than 3.5 mm in children with competent lips. Maximum number of injuries occurred in the age group of 13-14 years. The most predominant type of injury was the enamel fracture and the most common cause determined was due to fall. The present study is a collection of data on traumatic injuries to anterior teeth, which is seen very commonly in day-to-day practice. The frequency and cause of traumatic injuries to anterior teeth is important for identification of risk groups, treatment needs, and cost involved in order for establishing effective preventive measures. Hegde R, Agrawal G. Prevalence of Traumatic Dental Injuries to the Permanent Anterior Teeth among 9- to 14-year-old Schoolchildren of Navi Mumbai (Kharghar-Belapur Region), India. Int J Clin Pediatr Dent 2017;10(2):177-182.

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.

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms

PubMed Central

Deshaies, Eric M; Villwock, Mark R; Singla, Amit; Toshkezi, Gentian; Padalino, David J

2015-01-01

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients ≤55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged ≤55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges: $52,779 vs. $101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average. PMID:26325337

Nature and origin of basin-forming projectiles

NASA Astrophysics Data System (ADS)

Wetherill, G. W.

The formation of the observed lunar multi-ring basins is discussed in the context of current theories of terrestrial planet formation, particularly those in which these planets formed by the accumulation of large planetesimals. The observed number, size, and timing of lunar basin-forming impacts is in the range expected for such theories. Tidal disruption during close encounters to earth and Venus can provide a single mechanism that explains a number of details concerning the number, size distribution, and stochastic nature of the timing of these impacts. A basin time scale is suggested in which Nectaris is associated with the 4.1 b.y. age of the Apollo 16 light matrix breccias. In accordance with the present consensus, Serenitatis is 3.86 b.y., Imbrium and Orientale 3.80-3.82 b.y. in age. Other nearside circular basins (e.g., Humorum and Crisium) are intermediate in age between 3.86 and 4.12 b.y. The large number of 3.8-3.9 b.y. ages is attributed primarily to the magnitude of the Imbrium and Serenitatis impacts, and sampling bias resulting from concentration of collection sites in proximity to these basins.

Expression of EphA2 protein is positively associated with age, tumor size and Fuhrman nuclear grade in clear cell renal cell carcinomas.

PubMed

Wang, Longxin; Hu, Haibing; Tian, Feng; Zhou, Wenquan; Zhou, Shuigen; Wang, Jiandong

2015-01-01

The receptor tyrosine kinase of EphA2 has been shown frequently overexpressed in various types of human carcinomas, which implicated that it plays important roles in carcinogenesis. Although EphA2 protein expression has been investigated in many types of human carcinomas, the relationship between the expression of EphA2 protein in clear cell renal cell carcinoma was not well documented. In the present study, using specific anit-EphA2 polyclonal antibody and immunohistochemistry, we evaluated EphA2 protein expression levels in clear cell RCC specimens surgically resected from 90 patients. Our results shows that EphA2 protein was positively expressed in all normal renal tubes of 90 samples (100%, 3+), which was expressed at low levels in renal cortex but high levels in the collecting ducts of the renal medulla and papilla. EphA2 was negatively or weakly expressed in 30 out of 90 samples (33.3%, 0/1+), moderately expressed in 24 samples (26.7%, 2+) and strongly expressed in 36 samples (40%, 3+). Expression of EphA2 was positively associated with age (P=0.029), tumor diameters (P<0.001) and Fuhrman nuclear grade (P<0.001). Our results indicate that EphA2 variably expressed in clear cell renal cell carcinomas. High expression of EphA2 was more often found in big size and high nuclear grade tumors, which indicated EphA2 protein may be used as a new marker for the prognosis of clear cell renal cell carcinoma.

The Flynn Effect: A Meta-analysis

PubMed Central

Trahan, Lisa; Stuebing, Karla K.; Hiscock, Merril K.; Fletcher, Jack M.

2014-01-01

The “Flynn effect” refers to the observed rise in IQ scores over time, resulting in norms obsolescence. Although the Flynn effect is widely accepted, most approaches to estimating it have relied upon “scorecard” approaches that make estimates of its magnitude and error of measurement controversial and prevent determination of factors that moderate the Flynn effect across different IQ tests. We conducted a meta-analysis to determine the magnitude of the Flynn effect with a higher degree of precision, to determine the error of measurement, and to assess the impact of several moderator variables on the mean effect size. Across 285 studies (N = 14,031) since 1951 with administrations of two intelligence tests with different normative bases, the meta-analytic mean was 2.31, 95% CI [1.99, 2.64], standard score points per decade. The mean effect size for 53 comparisons (N = 3,951) (excluding three atypical studies that inflate the estimates) involving modern (since 1972) Stanford-Binet and Wechsler IQ tests (2.93, 95% CI [2.3, 3.5], IQ points per decade) was comparable to previous estimates of about 3 points per decade, but not consistent with the hypothesis that the Flynn effect is diminishing. For modern tests, study sample (larger increases for validation research samples vs. test standardization samples) and order of administration explained unique variance in the Flynn effect, but age and ability level were not significant moderators. These results supported previous estimates of the Flynn effect and its robustness across different age groups, measures, samples, and levels of performance. PMID:24979188

Convoys of Social Relations in Cross-National Context.

PubMed

Ajrouch, Kristine J; Fuller, Heather R; Akiyama, Hiroko; Antonucci, Toni C

2018-05-08

This study examines national variations in social networks among older adults across 4 countries in diverse regions of the world: Japan, Lebanon, Mexico, and the United States. The aim is to provide insights into universal as well as unique attributes of social networks in later life. The analyses examine convoy characteristics among adults aged 50+ in metropolitan areas of Japan (N = 557), Lebanon (N = 284), Mexico (N = 556), and the United States (N = 583). Data were collected using the hierarchical mapping technique on representative samples in each locale. Multilevel models were conducted by nation to examine whether convoy characteristics vary by age and closeness. Network size and geographic proximity were dimensions of social networks sensitive to national context. By contrast, how age and feelings of closeness varied with contact frequency and the presence of children in networks revealed universal patterns. Furthermore, feelings of closeness varied by age with regard to size and contact frequency in Lebanon, proximity in Japan, and composition in Mexico. Identifying universal and unique characteristics of social networks in later life provide a preliminary empirical basis upon which to advance a global perspective on convoys of social relations and how they inform policies that can facilitate health and well-being among middle-aged and older people around the world.

Analyzing the Formation, Physicochemical, and Optical Properties of Aging Biomass Burning Aerosol Using an Indoor Smog Chamber

NASA Astrophysics Data System (ADS)

Smith, D. M.; Fiddler, M. N.; Bililign, S.; Spann, M.

2017-12-01

Biomass burning (BB) is recognized as one of the largest sources of absorbing aerosols in the atmosphere and significantly influences the radiative properties of the atmosphere. The chemical composition and physical properties of particles evolve during their atmospheric lifetime due to condensation, oxidation reactions, etc., which alters their optical properties. To this end, an indoor smog chamber was constructed to study aging BB aerosol in a laboratory setting. Injections to the chamber, including NOx, O3, and various biogenic and anthropogenic VOCs, can simulate a variety of atmospheric conditions. These components and some of their oxidation products are monitored during the aging process. A tube furnace is used for combustion of biomass to be introduced to the chamber, while size distributions are taken as the aerosol ages. Online measurements of optical properties are determined using a Cavity Ring-down Spectrometry and Integrating Nephelometry system. Chemical properties are measured from samples captured on filters and analyzed using Ultra-Performance Liquid Chromatography coupled in-line to both a Diode Array Detector and High-Resolution Time-of-Flight Mass Spectrometer equipped with electrospray ionization. The measured changes in the optical properties as a function of particle size, aging, and chemical properties are presented for fuel sources used in Africa.

Socioeconomic Status (SES) and Children's Intelligence (IQ): In a UK-Representative Sample SES Moderates the Environmental, Not Genetic, Effect on IQ

PubMed Central

Hanscombe, Ken B.; Trzaskowski, Maciej; Haworth, Claire M. A.; Davis, Oliver S. P.; Dale, Philip S.; Plomin, Robert

2012-01-01

Background The environment can moderate the effect of genes - a phenomenon called gene-environment (GxE) interaction. Several studies have found that socioeconomic status (SES) modifies the heritability of children's intelligence. Among low-SES families, genetic factors have been reported to explain less of the variance in intelligence; the reverse is found for high-SES families. The evidence however is inconsistent. Other studies have reported an effect in the opposite direction (higher heritability in lower SES), or no moderation of the genetic effect on intelligence. Methods Using 8716 twin pairs from the Twins Early Development Study (TEDS), we attempted to replicate the reported moderating effect of SES on children's intelligence at ages 2, 3, 4, 7, 9, 10, 12 and 14: i.e., lower heritability in lower-SES families. We used a twin model that allowed for a main effect of SES on intelligence, as well as a moderating effect of SES on the genetic and environmental components of intelligence. Results We found greater variance in intelligence in low-SES families, but minimal evidence of GxE interaction across the eight ages. A power calculation indicated that a sample size of about 5000 twin pairs is required to detect moderation of the genetic component of intelligence as small as 0.25, with about 80% power - a difference of 11% to 53% in heritability, in low- (−2 standard deviations, SD) and high-SES (+2 SD) families. With samples at each age of about this size, the present study found no moderation of the genetic effect on intelligence. However, we found the greater variance in low-SES families is due to moderation of the environmental effect – an environment-environment interaction. Conclusions In a UK-representative sample, the genetic effect on intelligence is similar in low- and high-SES families. Children's shared experiences appear to explain the greater variation in intelligence in lower SES. PMID:22312423

Shoulder strength value differences between genders and age groups.

PubMed

Balcells-Diaz, Eudald; Daunis-I-Estadella, Pepus

2018-03-01

The strength of a normal shoulder differs according to gender and decreases with age. Therefore, the Constant score, which is a shoulder function measurement tool that allocates 25% of the final score to strength, differs from the absolute values but likely reflects a normal shoulder. To compare group results, a normalized Constant score is needed, and the first step to achieving normalization involves statistically establishing the gender differences and age-related decline. In this investigation, we sought to verify the gender difference and age-related decline in strength. We obtained a randomized representative sample of the general population in a small to medium-sized Spanish city. We then invited this population to participate in our study, and we measured their shoulder strength. We performed a statistical analysis with a power of 80% and a P value < .05. We observed a statistically significant difference between the genders and a statistically significant decline with age. To the best of our knowledge, this is the first investigation to study a representative sample of the general population from which conclusions can be drawn regarding Constant score normalization. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Identification of a protein with antioxidant activity that is important for the protection against beer ageing.

PubMed

Wu, Ming J; Clarke, Frank M; Rogers, Peter J; Young, Paul; Sales, Narelle; O'Doherty, Patrick J; Higgins, Vincent J

2011-01-01

This study was carried out with fresh Australian lager beer which was sampled directly off the production line, the same samples aged for 12 weeks at 30 °C, and the vintage beer which was kept at 20 °C for 5 years. Characteristic Australian lager flavour was maintained in the fresh and vintage beers but was lost in the aged beer. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and free thiol group labelling analyses of beer proteins found that this flavour stability correlated with the presence of an unknown 10 kilodaltons (kDa) protein with a higher level of free thiols. The protein was purified by size-exclusion chromatography, then peptide sequencing and database matching identified it as the barley lipid transfer protein (LTP1). Further characterisation using diphenylpicrylhydrazyl (DPPH) free radical scavenging and a Saccharomyces cerevisiae-based antioxidant screening assay demonstrated that the LTP1 protein was active in DPPH reduction and antioxidant activity. The absence of free thiol in the aged beer indicates that the thiol functional groups within the LTP1 protein were saturated and suggests that it is important in the flavour stability of beer by maintaining reduction capacity during the ageing process.

Pb-Pb systematics of lunar rocks: differentiation, magmatic and impact history of the Moon

NASA Astrophysics Data System (ADS)

Nemchin, A.; Martin, W.; Norman, M. D.; Snape, J.; Bellucci, J. J.; Grange, M.

2016-12-01

Two independent decay chains in U-Pb system allow the determination of both ages and initial isotope compositions by analyzing only Pb in the samples. A typical Pb analysis represents a mixture of radiogenic Pb produced from the in situ U decay, initial Pb and laboratory contamination. Utilizing the ability of ion probes to analyse 10-30 micrometer-sized spots in the samples while avoiding fractures and other imperfections that commonly host contamination, permits extraction of pure lunar Pb compositions from the three component mixtures. This results in both accurate and precise ages of the rocks and their initial compositions. Lunar Mare and KREEP basalts postdating the major lunar bombardment are likely to represent such three component mixtures and are therefore appropriate for this approach, also giving an opportunity to investigate Pb evolution in their sources. A source evolution model constrained using available data indicates a major differentiation on the Moon at 4376±18 Ma and very radiogenic lunar mantle at this time. This age is likely to reflect the mean time of KREEP formation during the last stage of Magma Ocean differentiation. Rocks older than about 3.9 Ga are more complex than basalts and may include an extra Pb component, if modified by impacts. An example of this is presented by Pb-Pb data obtained for the anorthosite sample 62236, where the age of the rock is determined as 4367±29 Ma from analyses of CPx lamellae inside the large Opx grains: however large plagioclase crystals do not contain Pb in quantities sufficient for ion probe analysis, precluding determination of the initial Pb composition of the sample. Most of Pb is found in the brecciated parts of the anorthosite between the large grains. The composition of this Pb is similar to the initial Pb of 3909±17 Ma Apollo 16 breccia 66095, suggesting that is was injected into the anorthosite during a 3.9 Ga impact. Similar ca 3.9 Ga ages were determined for 1-2 millimeter size feldspathic clasts from several Apollo 14 breccias, where they are likely to date Pb homogenization during the Imbrium impact. Combined with U-Pb data obtained previously using U-bearing minerals such as zircon and phosphates, the new Pb-Pb data sets open an opportunity for a detailed chronological and isotopic investigation of lunar differentiation, magmatic evolution and impact history.

Cumulative contextual and individual disadvantages over the life course and adult functional somatic symptoms in Sweden.

PubMed

Gustafsson, Per E; Hammarström, Anne; San Sebastian, Miguel

2015-08-01

Disadvantage, originating in one's residential context or in one's past life course, has been shown to impact on health in adulthood. There is however little research on the accumulated health impact of both neighbourhood and individual conditions over the life course. This study aims to examine whether the accumulation of contextual and individual disadvantages from adolescence to middle-age predicts functional somatic symptoms (FSS) in middle-age, taking baseline health into account. The sample is the age 16, 21, 30 and 42 surveys of the prospective Northern Swedish Cohort, with analytical sample size n = 910 (85% of the original cohort). FSS at age 16 and 42, and cumulative socioeconomic disadvantage, social adversity and material adversity between 16 and 42 years were operationalized from questionnaires, and cumulative neighbourhood disadvantage between 16 and 42 years from register data. Results showed accumulation of disadvantages jointly explained 9-12% of FSS variance. In the total sample, cumulative neighbourhood and socioeconomic disadvantage significantly predicted FSS at age 42 in the total sample. In women, neighbourhood disadvantage but not socioeconomic disadvantage contributed significantly, whereas in men, socioeconomic but not neighbourhood disadvantage contributed significantly. In all analyses, associations were largely explained by the parallel accumulation of social and material adversities, but not by symptoms at baseline. In conclusion, the accumulation of diverse forms of disadvantages together plays an important role for somatic complaints in adulthood, independently of baseline health. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Cognitive and Occupational Function in Survivors of Adolescent Cancer.

PubMed

Nugent, Bethany D; Bender, Catherine M; Sereika, Susan M; Tersak, Jean M; Rosenzweig, Margaret

2018-02-01

Adolescents with cancer have unique developmental considerations. These include brain development, particularly in the frontal lobe, and a focus on completing education and entering the workforce. Cancer and treatment at this stage may prove to uniquely affect survivors' experience of cognitive and occupational function. An exploratory, cross-sectional, descriptive comparative study was employed to describe cognitive and occupational function in adult survivors of adolescent cancer (diagnosed between the ages of 15 and 21 years) and explore differences in age- and gender-matched controls. In total, 23 survivors and 14 controls participated in the study. While significant differences were not found between the groups on measures of cognitive and occupational function, several small and medium effect sizes were found suggesting that survivors may have greater difficulty than controls. Two small effect sizes were found in measures of neuropsychological performance (the Digit Vigilance test [d = 0.396] and Stroop test [d = 0.226]). Small and medium effect sizes ranging from 0.269 to 0.605 were found for aspects of perceived and total cognitive function. A small effect size was also found in work output (d = 0.367). While we did not find significant differences in cognitive or occupational function between survivors and controls, the effect sizes observed point to the need for future research. Future work using a larger sample size and longitudinal design are needed to further explore cognitive and occupational function in this vulnerable and understudied population and assist in the understanding of patterns of change over time.

Overweight/obesity is associated with food choices related to rice and beans, colors of salads, and portion size among consumers at a restaurant serving buffet-by-weight in Brazil.

PubMed

Rodrigues, Alline Gouvea Martins; Proença, Rossana Pacheco da Costa; Calvo, Maria Cristina Marino; Fiates, Giovanna Medeiros Rataichesck

2012-10-01

The present study investigated the prevalence of overweight/obesity and its relationship with behavioral and food choice characteristics among consumers at a restaurant serving buffet-by-weight in the city of Florianopolis, southern Brazil, during lunch time. An analytical cross-sectional survey of 675 consumers aged 16-81 years was conducted. The measures included anthropometric, socio-demographic, and behavioral characteristics, as well as portion size and a photographic record of the plate chosen by the consumer. The results indicated a prevalence of overweight/obesity in the sample of 33.8%. Overall, after an adjustment for other variables (sex, age, schooling, marital status, and food choice variables), overweight/obesity was positively associated with not choosing rice and beans (PR=1.11) and larger portion sizes (PR=1.08 for a portion size of 347-462 g and PR=1.16 for a portion size of 463 g or more). Moreover, choosing 1-2 colors of salads showed a positive association when compared with choosing 3 or more colors of salads (PR=1.06). Efforts in helping consumers make healthier food choices when eating out and thereby possibly reduce weight gain should address those aspects along with socio-demographic factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Age differences in change-of-direction performance and its subelements in female football players.

PubMed

Hirose, Norikazu; Nakahori, Chikako

2015-05-01

To describe cross-sectional age differences in change-of-direction performance (CODp) in female football players and investigate the relationship between CODp and linear-sprint speed, muscle power, and body size. A sample of 135 well-trained female football players was divided into 8 age groups. Anthropometry (height, body mass, and lean body mass) and athletic performance (10-m sprint speed, 10-m×5-CODp, and 5-step bounding distance) were compared to determine interage differences using ANOVA. Then, the participants were divided into 3 age groups: 12- to 14-y-olds, 15- to 17-y-olds, and ≥18 y-olds. Simple- and multiple-regression analyses were conducted to determine the correlation between CODp and the other measurement variables in each age group. Age-related differences were found for CODp (F=10.41, P<.01), sprint speed (F=3.27, P<.01), and bounding distance (F=4.20, P<.01). Post hoc analysis revealed that the CODp of 17-y-old players was faster than that of 16-y-old players (P<.01), with no interage differences in sprint speed and bounding distance. Sprint speed and bounding distance were weakly correlated with CODp in 15- to ≥18-y-old players, but only sprint speed was correlated with CODp in 12- to 14-y-old players. CODp improves from 16 to 17 y of age in female players. Linear-sprint speed, muscle power, and body size were weakly correlated with the age differences in CODp.

Age affects sleep microstructure more than sleep macrostructure.

PubMed

Schwarz, Johanna F A; Åkerstedt, Torbjörn; Lindberg, Eva; Gruber, Georg; Fischer, Håkan; Theorell-Haglöw, Jenny

2017-06-01

It is well known that the quantity and quality of physiological sleep changes across age. However, so far the effect of age on sleep microstructure has been mostly addressed in small samples. The current study examines the effect of age on several measures of sleep macro- and microstructure in 211 women (22-71 years old) of the 'Sleep and Health in Women' study for whom ambulatory polysomnography was registered. Older age was associated with significantly lower fast spindle (effect size f 2  = 0.32) and K-complex density (f 2  = 0.19) during N2 sleep, as well as slow-wave activity (log) in N3 sleep (f 2  = 0.21). Moreover, total sleep time (f 2  = 0.10), N3 sleep (min) (f 2  = 0.10), rapid eye movement sleep (min) (f 2  = 0.11) and sigma (log) (f 2  = 0.05) and slow-wave activity (log) during non-rapid eye movement sleep (f 2  = 0.09) were reduced, and N1 sleep (f 2  = 0.03) was increased in older age. No significant effects of age were observed on slow spindle density, rapid eye movement density and beta power (log) during non-rapid eye movement sleep. In conclusion, effect sizes indicate that traditional sleep stage scoring may underestimate age-related changes in sleep. © 2017 European Sleep Research Society.

Publication Bias in Psychology: A Diagnosis Based on the Correlation between Effect Size and Sample Size

PubMed Central

Kühberger, Anton; Fritz, Astrid; Scherndl, Thomas

2014-01-01

Background The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias. Methods We investigate whether effect size is independent from sample size in psychological research. We randomly sampled 1,000 psychological articles from all areas of psychological research. We extracted p values, effect sizes, and sample sizes of all empirical papers, and calculated the correlation between effect size and sample size, and investigated the distribution of p values. Results We found a negative correlation of r = −.45 [95% CI: −.53; −.35] between effect size and sample size. In addition, we found an inordinately high number of p values just passing the boundary of significance. Additional data showed that neither implicit nor explicit power analysis could account for this pattern of findings. Conclusion The negative correlation between effect size and samples size, and the biased distribution of p values indicate pervasive publication bias in the entire field of psychology. PMID:25192357

Publication bias in psychology: a diagnosis based on the correlation between effect size and sample size.

PubMed

Kühberger, Anton; Fritz, Astrid; Scherndl, Thomas

2014-01-01

The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias. We investigate whether effect size is independent from sample size in psychological research. We randomly sampled 1,000 psychological articles from all areas of psychological research. We extracted p values, effect sizes, and sample sizes of all empirical papers, and calculated the correlation between effect size and sample size, and investigated the distribution of p values. We found a negative correlation of r = -.45 [95% CI: -.53; -.35] between effect size and sample size. In addition, we found an inordinately high number of p values just passing the boundary of significance. Additional data showed that neither implicit nor explicit power analysis could account for this pattern of findings. The negative correlation between effect size and samples size, and the biased distribution of p values indicate pervasive publication bias in the entire field of psychology.

Sarcopenia, dynapenia, and the impact of advancing age on human skeletal muscle size and strength; a quantitative review.

PubMed

Mitchell, W Kyle; Williams, John; Atherton, Philip; Larvin, Mike; Lund, John; Narici, Marco

2012-01-01

Changing demographics make it ever more important to understand the modifiable risk factors for disability and loss of independence with advancing age. For more than two decades there has been increasing interest in the role of sarcopenia, the age-related loss of muscle or lean mass, in curtailing active and healthy aging. There is now evidence to suggest that lack of strength, or dynapenia, is a more constant factor in compromised wellbeing in old age and it is apparent that the decline in muscle mass and the decline in strength can take quite different trajectories. This demands recognition of the concept of muscle quality; that is the force generating per capacity per unit cross-sectional area (CSA). An understanding of the impact of aging on skeletal muscle will require attention to both the changes in muscle size and the changes in muscle quality. The aim of this review is to present current knowledge of the decline in human muscle mass and strength with advancing age and the associated risk to health and survival and to review the underlying changes in muscle characteristics and the etiology of sarcopenia. Cross-sectional studies comparing young (18-45 years) and old (>65 years) samples show dramatic variation based on the technique used and population studied. The median of values of rate of loss reported across studies is 0.47% per year in men and 0.37% per year in women. Longitudinal studies show that in people aged 75 years, muscle mass is lost at a rate of 0.64-0.70% per year in women and 0.80-00.98% per year in men. Strength is lost more rapidly. Longitudinal studies show that at age 75 years, strength is lost at a rate of 3-4% per year in men and 2.5-3% per year in women. Studies that assessed changes in mass and strength in the same sample report a loss of strength 2-5 times faster than loss of mass. Loss of strength is a more consistent risk for disability and death than is loss of muscle mass.

Prepotent response inhibition and interference control in autism spectrum disorders: two meta-analyses.

PubMed

Geurts, Hilde M; van den Bergh, Sanne F W M; Ruzzano, Laura

2014-08-01

There is a substantial amount of data providing evidence for, but also against the hypothesis that individuals with autism spectrum disorders (ASD) encounter inhibitory control deficits. ASD is often associated with interference control deficits rather than prepotent response inhibition. Moreover, the developmental trajectory for these inhibitory control processes is hypothesized to differ in ASD as compared to typical development. In efforts to gain a more comprehensive perspective of inhibition in ASD, separate quantitative analysis for prepotent response inhibition studies and interference control studies were conducted. Together, these two meta-analyses included 41 studies with a combined sample size of 1,091 people with ASD (M age 14.8 years), and 1,306 typically developing (TD) controls (M age 13.8 years).The meta-analyses indicated that individuals with ASD show increased difficulties in prepotent response inhibition (effect size 0.55) and in interference control (effect size 0.31). In addition, age was a relevant moderator for prepotent response inhibition but not for interference control. Exploratory analyses revealed that when IQ was taken into account, heterogeneity considerably decreased among interference control studies but not among prepotent response inhibition. In contrast to the general belief, both prepotent response inhibition and interference control problems were observed in individuals with ASD. However, a large variation between studies was also found. Therefore, there remain factors beyond inhibition type, age, or IQ that significantly influence inhibitory control performance among individuals with ASD. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

Brain enlargement is associated with regression in preschool-age boys with autism spectrum disorders

PubMed Central

Nordahl, Christine Wu; Lange, Nicholas; Li, Deana D.; Barnett, Lou Ann; Lee, Aaron; Buonocore, Michael H.; Simon, Tony J.; Rogers, Sally; Ozonoff, Sally; Amaral, David G.

2011-01-01

Autism is a heterogeneous disorder with multiple behavioral and biological phenotypes. Accelerated brain growth during early childhood is a well-established biological feature of autism. Onset pattern, i.e., early onset or regressive, is an intensely studied behavioral phenotype of autism. There is currently little known, however, about whether, or how, onset status maps onto the abnormal brain growth. We examined the relationship between total brain volume and onset status in a large sample of 2- to 4-y-old boys and girls with autism spectrum disorder (ASD) [n = 53, no regression (nREG); n = 61, regression (REG)] and a comparison group of age-matched typically developing controls (n = 66). We also examined retrospective head circumference measurements from birth through 18 mo of age. We found that abnormal brain enlargement was most commonly found in boys with regressive autism. Brain size in boys without regression did not differ from controls. Retrospective head circumference measurements indicate that head circumference in boys with regressive autism is normal at birth but diverges from the other groups around 4–6 mo of age. There were no differences in brain size in girls with autism (n = 22, ASD; n = 24, controls). These results suggest that there may be distinct neural phenotypes associated with different onsets of autism. For boys with regressive autism, divergence in brain size occurs well before loss of skills is commonly reported. Thus, rapid head growth may be a risk factor for regressive autism. PMID:22123952

Predicting breeding bird occurrence by stand- and microhabitat-scale features in even-aged stands in the Central Appalachians

USGS Publications Warehouse

McDermott, M.E.; Wood, P.B.; Miller, G.W.; Simpson, B.T.

2011-01-01

Spatial scale is an important consideration when managing forest wildlife habitat, and models can be used to improve our understanding of these habitats at relevant scales. Our objectives were to determine whether stand- or microhabitat-scale variables better predicted bird metrics (diversity, species presence, and abundance) and to examine breeding bird response to clearcut size and age in a highly forested landscape. In 2004-2007, vegetation data were collected from 62 even-aged stands that were 3.6-34.6. ha in size and harvested in 1963-1990 on the Monongahela National Forest, WV, USA. In 2005-2007, we also surveyed birds at vegetation plots. We used classification and regression trees to model breeding bird habitat use with a suite of stand and microhabitat variables. Among stand variables, elevation, stand age, and stand size were most commonly retained as important variables in guild and species models. Among microhabitat variables, medium-sized tree density and tree species diversity most commonly predicted bird presence or abundance. Early successional and generalist bird presence, abundance, and diversity were better predicted by microhabitat variables than stand variables. Thus, more intensive field sampling may be required to predict habitat use for these species, and management may be needed at a finer scale. Conversely, stand-level variables had greater utility in predicting late-successional species occurrence and abundance; thus management decisions and modeling at this scale may be suitable in areas with a uniform landscape, such as our study area. Our study suggests that late-successional breeding bird diversity can be maximized long-term by including harvests >10. ha in size into our study area and by increasing tree diversity. Some harvesting will need to be incorporated regularly, because after 15 years, the study stands did not provide habitat for most early successional breeding specialists. ?? 2010 Elsevier B.V.

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

Majid, Z.A.; Mahmud, H.; Shaaban, M.G.

Stabilization/solidification of hazardous wastes is used to convert hazardous metal hydroxide waste sludge into a solid mass with better handling properties. This study investigated the pore size development of ordinary portland cement pastes containing metal hydroxide waste sludge and rice husk ash using mercury intrusion porosimetry. The effects of acre and the addition of rice husk ash on pore size development and strength were studied. It was found that the pore structures of mixes changed significantly with curing acre. The pore size shifted from 1,204 to 324 {angstrom} for 3-day old cement paste, and from 956 to 263 {angstrom} formore » a 7-day old sample. A reduction in pore size distribution for different curing ages was also observed in the other mixtures. From this limited study, no conclusion could be made as to any correlation between strength development and porosity. 10 refs., 6 figs., 3 tabs.« less

The size of an ethno-cultural community as a social determinant of health for Chinese seniors.

PubMed

Chau, Shirley; Lai, Daniel W L

2011-12-01

The present study investigated the link between the sizes of the Chinese community to the health of Chinese seniors in Canada. A secondary data analysis of survey data from a representative sample of 2,272 Chinese older adults aged 55 and over was conducted. Hierarchical regression analyses were performed to assess the effects of the size of Chinese communities in Chinese seniors' health. Chinese seniors residing in the community with a small Chinese population reported better physical and mental health than the Chinese seniors residing in communities with a larger Chinese population. The findings were contrary to expectations that health of Chinese seniors should be higher in cities with large Chinese communities. These findings raise new questions for future investigations into the dynamics and impact of ethnic community size, and the importance of studying intragroup differences within ethno-cultural groups to better understand health disparities in ethnic groups.

The State of Sleep among College Students at a Large Public University

ERIC Educational Resources Information Center

Orzech, Kathryn M.; Salafsky, David B.; Hamilton, Lee Ann

2011-01-01

Objective: Data about college student sleep were collected and used to develop an education campaign to improve sleep. Participants: On-campus residents at a large state university were surveyed on 4 occasions, October 2005 to April 2007. Sample size was 675 to 1,823 students. Fall 2005 mean age = 18.5 years, SD = 1.03 (range 18-30) years. Initial…

Body Size, Fatness, and Leanness of Mexican American Children in Brownsville, Texas: Changes Between 1972 and 1983.

ERIC Educational Resources Information Center

Malina, Robert M.; And Others

1987-01-01

Changes in physical dimensions of a sample of lower socioeconomic Mexican American children, ages 6 through 17, from Brownsville, TX, were documented on the basis of surveys done in 1972 and 1983. Results suggest that these youth are similar in growth to other Mexican American youth, and confirm large proportion of relatively short but heavy…

Size-fractionation and characterization of landfill leachate and the improvement of Cu{sup 2+} adsorption capacity in soil and aged refuse

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

Lou Ziyang; State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092; Chai Xiaoli

2009-01-15

Leachate was collected from an anaerobic lagoon at Shanghai Laogang refuse landfill, the largest landfill in China, and the sample was separated into six fractions using micro-filtration membranes, followed by ultra-filtration membranes. Several parameters of the samples were measured, including chemical oxygen demand (COD), total organic carbon (TOC), total solids (TS), pH, total phosphate (TP), total nitrogen (TN), fixed solids (FS), NH{sub 4}{sup +}, orthophosphate, color, turbidity, and conductivity. These parameters were then quantitatively correlated with the molecular weight cutoff of the membrane used. Organic matter in the dissolved fraction (MW < 1 kDa) predominated in the leachate, accounting formore » 65% of TOC. Thermal infrared spectroscopy was used to characterize the filter residues. Asymmetric and symmetric stretching of methyl and methylene groups, and of functional groups containing nitrogen and oxygen atoms, were observed. In addition, the ability of two different samples to adsorb heavy metals was tested. Cu{sup 2+} was chosen as the representative heavy metal in this study, and the samples were soil; aged refuse, which had spent 8 years in a conventional sanitary landfill; and samples of soil and aged refuse treated for 48 h with leachate in the ratio of 5 g of sample per 50 ml of leachate. Cu{sup 2+} uptake by the raw soil was {approx}4.60 {mu}g/g, while uptake by the leachate-contacted soil and leachate-contacted aged refuse were 5.66 and 5.11 {mu}g/g, respectively. These results show that the organic matter in the leachate enhanced the capacity of aqueous solutions to adsorb Cu{sup 2+}.« less

Optimum sample size allocation to minimize cost or maximize power for the two-sample trimmed mean test.

PubMed

Guo, Jiin-Huarng; Luh, Wei-Ming

2009-05-01

When planning a study, sample size determination is one of the most important tasks facing the researcher. The size will depend on the purpose of the study, the cost limitations, and the nature of the data. By specifying the standard deviation ratio and/or the sample size ratio, the present study considers the problem of heterogeneous variances and non-normality for Yuen's two-group test and develops sample size formulas to minimize the total cost or maximize the power of the test. For a given power, the sample size allocation ratio can be manipulated so that the proposed formulas can minimize the total cost, the total sample size, or the sum of total sample size and total cost. On the other hand, for a given total cost, the optimum sample size allocation ratio can maximize the statistical power of the test. After the sample size is determined, the present simulation applies Yuen's test to the sample generated, and then the procedure is validated in terms of Type I errors and power. Simulation results show that the proposed formulas can control Type I errors and achieve the desired power under the various conditions specified. Finally, the implications for determining sample sizes in experimental studies and future research are discussed.

Incidental Lewy Body Disease: Clinical Comparison to a Control Cohort

PubMed Central

Adler, Charles H.; Connor, Donald J.; Hentz, Joseph G.; Sabbagh, Marwan N.; Caviness, John N.; Shill, Holly A.; Noble, Brie; Beach, Thomas G.

2010-01-01

Limited clinical information has been published on cases pathologically diagnosed with incidental Lewy body disease (ILBD). Standardized, longitudinal movement and cognitive data was collected on a cohort of subjects enrolled in the Sun Health Research Institute Brain and Body Donation Program. Of 277 autopsied subjects who had antemortem clinical evaluations within the previous 3 years, 76 did not have Parkinson’s disease, a related disorder, or dementia of which 15 (20%) had ILBD. Minor extrapyramidal signs were common in subjects with and without ILBD. Cognitive testing revealed an abnormality in the ILBD group in the Trails B test only. ILBD cases had olfactory dysfunction; however, sample size was very small. This preliminary report revealed ILBD cases have movement and cognitive findings that for the most part were not out of proportion to similarly assessed and age-similar cases without Lewy bodies. Larger sample size is needed to have the power to better assess group differences. PMID:20175211

Detecting a Weak Association by Testing its Multiple Perturbations: a Data Mining Approach

NASA Astrophysics Data System (ADS)

Lo, Min-Tzu; Lee, Wen-Chung

2014-05-01

Many risk factors/interventions in epidemiologic/biomedical studies are of minuscule effects. To detect such weak associations, one needs a study with a very large sample size (the number of subjects, n). The n of a study can be increased but unfortunately only to an extent. Here, we propose a novel method which hinges on increasing sample size in a different direction-the total number of variables (p). We construct a p-based `multiple perturbation test', and conduct power calculations and computer simulations to show that it can achieve a very high power to detect weak associations when p can be made very large. As a demonstration, we apply the method to analyze a genome-wide association study on age-related macular degeneration and identify two novel genetic variants that are significantly associated with the disease. The p-based method may set a stage for a new paradigm of statistical tests.

The demographic consequences of growing older and bigger in oyster populations.

PubMed

Moore, Jacob L; Lipcius, Romuald N; Puckett, Brandon; Schreiber, Sebastian J

2016-10-01

Structured population models, particularly size- or age-structured, have a long history of informing conservation and natural resource management. While size is often easier to measure than age and is the focus of many management strategies, age-structure can have important effects on population dynamics that are not captured in size-only models. However, relatively few studies have included the simultaneous effects of both age- and size-structure. To better understand how population structure, particularly that of age and size, impacts restoration and management decisions, we developed and compared a size-structured integral projection model (IPM) and an age- and size-structured IPM, using a population of Crassostrea gigas oysters in the northeastern Pacific Ocean. We analyzed sensitivity of model results across values of local retention that give populations decreasing in size to populations increasing in size. We found that age- and size-structured models yielded the best fit to the demographic data and provided more reliable results about long-term demography. Elasticity analysis showed that population growth rate was most sensitive to changes in the survival of both large (>175 mm shell length) and small (<75 mm shell length) oysters, indicating that a maximum size limit, in addition to a minimum size limit, could be an effective strategy for maintaining a sustainable population. In contrast, the purely size-structured model did not detect the importance of large individuals. Finally, patterns in stable age and stable size distributions differed between populations decreasing in size due to limited local retention and populations increasing in size due to high local retention. These patterns can be used to determine population status and restoration success. The methodology described here provides general insight into the necessity of including both age- and size-structure into modeling frameworks when using population models to inform restoration and management decisions. © 2016 by the Ecological Society of America.

Life-history strategies of the rock hind grouper Epinephelus adscensionis at Ascension Island.

PubMed

Nolan, E T; Downes, K J; Richardson, A; Arkhipkin, A; Brickle, P; Brown, J; Mrowicki, R J; Shcherbich, Z; Weber, N; Weber, S B

2017-12-01

Epinephelus adscensionis sampled from Ascension Island, South Atlantic Ocean, exhibits distinct life-history traits, including larger maximum size and size at sexual maturity than previous studies have demonstrated for this species in other locations. Otolith analysis yielded a maximum estimated age of 25 years, with calculated von Bertalanffy growth parameters of: L ∞  = 55·14, K = 0·19, t 0  = -0·88. Monthly gonad staging and analysis of gonad-somatic index (I G ) provide evidence for spawning from July to November with an I G peak in August (austral winter), during which time somatic growth is also suppressed. Observed patterns of sexual development were supportive of protogyny, although further work is needed to confirm this. Mean size at sexual maturity for females was 28·9 cm total length (L T ; 95% C.I. 27·1-30·7 cm) and no females were found >12 years and 48·0 cm L T , whereas all confirmed males sampled were mature, >35·1 cm L T with an age range from 3 to 18 years. The modelled size at which 50% of individuals were male was 41·8 cm (95% C.I. 40·4-43·2 cm). As far as is known, this study represents the first comprehensive investigation into the growth and reproduction of E. adscensionis at its type locality of Ascension Island and suggests that the population may be affected less by fisheries than elsewhere in its range. Nevertheless, improved regulation of the recreational fishery and sustained monitoring of abundance, length frequencies and life-history parameters are needed to inform long-term management measures, which could include the creation of marine reserves, size or temporal catch limits and stricter export controls. © 2017 The Fisheries Society of the British Isles.

Specific-age group sex estimation of infants through geometric morphometrics analysis of pubis and ischium.

PubMed

Estévez Campo, Enrique José; López-Lázaro, Sandra; López-Morago Rodríguez, Claudia; Alemán Aguilera, Inmaculada; Botella López, Miguel Cecilio

2018-05-01

Sex determination of unknown individuals is one of the primary goals of Physical and Forensic Anthropology. The adult skeleton can be sexed using both morphological and metric traits on a large number of bones. The human pelvis is often used as an important element of adult sex determination. However, studies carried out about the pelvic bone in subadult individuals present several limitations due the absence of sexually dimorphic characteristics. In this study, we analyse the sexual dimorphism of the immature pubis and ischium bones, attending to their shape (Procrustes residuals) and size (centroid size), using an identified sample of subadult individuals composed of 58 individuals for the pubis and 83 for the ischium, aged between birth and 1year of life, from the Granada osteological collection of identified infants (Granada, Spain). Geometric morphometric methods and discriminant analysis were applied to this study. The results of intra- and inter-observer error showed good and excellent agreement in the location of coordinates of landmarks and semilandmarks, respectively. Principal component analysis performed on shape and size variables showed superposition of the two sexes, suggesting a low degree of sexual dimorphism. Canonical variable analysis did not show significant changes between the male and female shapes. As a consequence, discriminant analysis with leave-one-out cross validation provided low classification accuracy. The results suggested a low degree of sexual dimorphism supported by significant sexual dimorphism in the subadult sample and poor cross-validated classification accuracy. The inclusion of centroid size as a discriminant variable does not imply a significant improvement in the results of the analysis. The similarities found between the sexes prevent consideration of pubic and ischial morphology as a sex estimator in early stages of development. The authors suggest extending this study by analysing the different trajectories of shape and size in later ontogeny between males and females. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of valence state and particle size on NO oxidation in fresh and aged Pt-based diesel oxidation catalysts

NASA Astrophysics Data System (ADS)

Liang, Yanli; Ding, Xinmei; Zhao, Ming; Wang, Jianli; Chen, Yaoqiang

2018-06-01

To stabilize Pt, Magnesium-modified SiO2-Al2O3 materials was used to impregnate with Pt, which could strengthen the bonding effect between Pt and Mg. Before and after aging, both showed a higher dispersion. High valence state of Pt in fresh modified catalyst was unfavorable of NO oxidation, indicating that the valence state of Pt was the leader factor in fresh catalytic performance. While for the aged Mg-modified sample, its reaction temperature of 30% NO conversion lowered by around 30 °C. The Pt stabilization via interacting with Mg derives a relation that the variation of Pt valence state and its exposed sites played a significant role in fresh and aged catalytic NO activity, respectively.

The Age Conundrum: A Scoping Review of Younger Age or Adolescent and Young Adult as a Risk Factor for Clinical Distress, Depression, or Anxiety in Cancer

PubMed Central

David, Victoria; Giese-Davis, Janine

2015-01-01

This scoping review was conducted to understand the extent, range, and nature of current research on adolescents and young adults (AYA) with cancer and distress, depression, and anxiety (DDA). This information is necessary to find and aggregate valuable data on the AYA population embedded in generalized studies of DDA. Keyword searches of six relevant electronic databases identified 2156 articles, with 316 selected for abstract review and 40 for full text review. Full-text reviews and data extraction resulted in 34 studies being included, which ranged widely in design, sample size, age-range categorization, analysis methods, DDA measurement tool, overall study rigor, and quality of evidence. Studies very seldom reported using theory to guide their age categorization, with only four studies giving any rationale for their age-group definitions. All 34 studies found a significant association between at least one DDA construct and the younger age group relative to the older age groups at some point along the cancer trajectory. However, age as an independent risk factor for DDA is still unclear, as the relationship could be confounded by other age-related factors. Despite the wide range of definitions and effect sizes in the studies included in this review, one thing is clear: adolescents and young adults, however defined, are a distinct group within the cancer population with an elevated risk of DDA. Widespread adoption of a standard AYA age-range definition will be essential to any future meta-analytical psycho-oncology research in this population. PMID:26697266

The Age Conundrum: A Scoping Review of Younger Age or Adolescent and Young Adult as a Risk Factor for Clinical Distress, Depression, or Anxiety in Cancer.

PubMed

Lang, Michael J; David, Victoria; Giese-Davis, Janine

2015-12-01

This scoping review was conducted to understand the extent, range, and nature of current research on adolescents and young adults (AYA) with cancer and distress, depression, and anxiety (DDA). This information is necessary to find and aggregate valuable data on the AYA population embedded in generalized studies of DDA. Keyword searches of six relevant electronic databases identified 2156 articles, with 316 selected for abstract review and 40 for full text review. Full-text reviews and data extraction resulted in 34 studies being included, which ranged widely in design, sample size, age-range categorization, analysis methods, DDA measurement tool, overall study rigor, and quality of evidence. Studies very seldom reported using theory to guide their age categorization, with only four studies giving any rationale for their age-group definitions. All 34 studies found a significant association between at least one DDA construct and the younger age group relative to the older age groups at some point along the cancer trajectory. However, age as an independent risk factor for DDA is still unclear, as the relationship could be confounded by other age-related factors. Despite the wide range of definitions and effect sizes in the studies included in this review, one thing is clear: adolescents and young adults, however defined, are a distinct group within the cancer population with an elevated risk of DDA. Widespread adoption of a standard AYA age-range definition will be essential to any future meta-analytical psycho-oncology research in this population.

Synchrotron-induced X-ray fluorescence from rat bone and lumber vertebra of different age groups

NASA Astrophysics Data System (ADS)

Rao, Donepudi V.; Swapna, Medasani; Cesareo, Roberto; Brunetti, Antonio; Akatsuka, Tako; Yuasa, Tetsuya; Takeda, Tohoru; Tromba, Giuliana; Gigante, Giovanni E.

2009-02-01

The fluorescence spectra from rat bones of different age groups (8, 56 and 78 weeks) and lumber vertebra were measured with 8, 10 and 12 keV synchrotron X-rays. We have utilized the new hard X-ray micro-spectroscopy beamline facility, X27A, available at NSLS with a primary beam spot size of the order of ˜10 μm. With this spatial resolution and high flux throughput, X-ray fluorescent intensities for Ca and other trace elements were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. Regarding the lumber vertebra, we acquired the fluorescence spectra from the left, right and middle portions and calcium accumulation was evaluated and compared with the other samples. We have identified the major trace elements of Ca, Ni, Fe and Zn and minor trace elements of Ti, Cr and Mn in the sample. The percentage of scattered radiation and trace element contributions from these samples were highlighted at different energies.

Analysis of sexual behavior in adolescents.

PubMed

Teva, Inmaculada; Bermudez, M Paz; Ramiro, Maria T; Ramiro-Sanchez, Tamara

2013-10-01

The aim of this study was to describe some characteristics of vaginal, anal and oral sexual behavior in Spanish adolescents. It was a cross-sectional descriptive population study conducted using a probabilistic sample survey. The sample was composed of 4,612 male and female adolescents, of whom 1,686 reported having penetrative sexual experience. Sample size was established with a 97% confidence level and a 3% estimation error. Data collection took place in secondary education schools. Mean age of vaginal sex initiation was 15 years. Compared to females, males reported an earlier age of anal and oral sex initiation and a larger number of vaginal and anal sexual partners. Males also reported a higher frequency of penetrative sexual relations under the influence of alcohol or other drugs. A higher percentage of females than males reported not using a condom in their first anal sexual experience. This study provides a current overview of the sexual behavior of adolescents that can be useful for the design of future programs aimed at preventing HIV and sexually transmitted infections (STIs).

Theory of Positron Annihilation in Helium-Filled Bubbles in Plutonium

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

Sterne, P A; Pask, J E

2003-02-13

Positron annihilation lifetime spectroscopy is a sensitive probe of vacancies and voids in materials. This non-destructive measurement technique can identify the presence of specific defects in materials at the part-per-million level. Recent experiments by Asoka-Kumar et al. have identified two lifetime components in aged plutonium samples--a dominant lifetime component of around 182 ps and a longer lifetime component of around 350-400ps. This second component appears to increase with the age of the sample, and accounts for only about 5 percent of the total intensity in 35 year-old plutonium samples. First-principles calculations of positron lifetimes are now used extensively to guidemore » the interpretation of positron lifetime data. At Livermore, we have developed a first-principles finite-element-based method for calculating positron lifetimes for defects in metals. This method is capable of treating system cell sizes of several thousand atoms, allowing us to model defects in plutonium ranging in size from a mono-vacancy to helium-filled bubbles of over 1 nm in diameter. In order to identify the defects that account for the observed lifetime values, we have performed positron lifetime calculations for a set of vacancies, vacancy clusters, and helium-filled vacancy clusters in delta-plutonium. The calculations produced values of 143ps for defect-free delta-Pu and 255ps for a mono-vacancy in Pu, both of which are inconsistent with the dominant experimental lifetime component of 182ps. Larger vacancy clusters have even longer lifetimes. The observed positron lifetime is significantly shorter than the calculated lifetimes for mono-vacancies and larger vacancy clusters, indicating that open vacancy clusters are not the dominant defect in the aged plutonium samples. When helium atoms are introduced into the vacancy cluster, the positron lifetime is reduced due to the increased density of electrons available for annihilation. For a mono-vacancy in Pu containing one helium atom, the calculated lifetime is 190 ps, while a di-vacancy containing two helium atoms has a positron lifetime of 205 ps. In general, increasing the helium density in a vacancy cluster or He-filled bubble reduces the positron lifetime, so that the same lifetime value can arise fi-om a range of vacancy cluster sizes with different helium densities. In order to understand the variation of positron lifetime with vacancy cluster size and helium density in the defect, we have performed over 60 positron lifetime calculations with vacancy cluster sizes ranging from 1 to 55 vacancies and helium densities ranging fi-om zero to five helium atoms per vacancy. The results indicate that the experimental lifetime of 182 ps is consistent with the theoretical value of 190 ps for a mono-vacancy with a single helium atom, but that slightly better agreement is obtained for larger clusters of 6 or more vacancies containing 2-3 helium atoms per vacancy. For larger vacancy clusters with diameters of about 3-5 nm or more, the annihilation with helium electrons dominates the positron annihilation rate; the observed lifetime of 180ps is then consistent with a helium concentration in the range of 3 to 3.5 Hehacancy, setting an upper bound on the helium concentration in the vacancy clusters. In practice, the single lifetime component is most probably associated with a family of helium-filled bubbles rather than with a specific unique defect size. The longer 350-400ps lifetime component is consistent with a relatively narrow range of defect sizes and He concentration. At zero He concentration, the lifetime values are matched by small vacancy clusters containing 6-12 vacancies. With increasing vacancy cluster size, a small amount of He is required to keep the lifetime in the 350-400 ps range, until the value saturates for larger helium bubbles of more than 50 vacancies (bubble diameter > 1.3 nm) at a helium concentration close to 1 He/vacancy. These results, taken together with the experimental data, indicate that the features observed in TEM data by Schwartz et al are not voids, but are in fact helium-filled bubbles with a helium pressure of around 2-3 helium atoms per vacancy, depending on the bubble size. This is consistent with the conclusions of recently developed models of He-bubble growth in aged plutonium.« less

Growth dynamics of saffron cod (Eleginus gracilis) and Arctic cod (Boreogadus saida) in the Northern Bering and Chukchi Seas

NASA Astrophysics Data System (ADS)

Helser, Thomas E.; Colman, Jamie R.; Anderl, Delsa M.; Kastelle, Craig R.

2017-01-01

Saffron cod (Eleginus gracilis) and Arctic cod (Boreogadus saida) are two circumpolar gadids that serve as critically important species responsible for energy transfer in Arctic food webs of the northern Bering and Chukchi Seas. To understand the potential effects of sea ice loss and warming temperatures on these species' basic life history, information such as growth is needed. Yet to date, limited effort has been dedicated to the study of their growth dynamics. Based on a large sample of otoliths collected in the first comprehensive ecosystem integrated survey in the northern Bering and Chukchi Seas, procedures were developed to reliably estimate age from otolith growth zones and were used to study the growth dynamics of saffron and Arctic cod. Annual growth zone assignment was validated using oxygen isotope signatures in otoliths and otolith morphology analyzed and compared between species. Saffron cod attained larger asymptotic sizes (L∞=363 mm) and achieved their maximum size at a faster rate (K=0.378) than Arctic cod (L∞=209 mm; K=0.312). For both species, regional differences in growth were found (p<0.01). Saffron cod grew to a significantly larger size at age in the northern Bering Sea when compared to the Chukchi Sea, particularly at younger ages. Arctic cod grew to smaller asymptotic size but at faster rates in the more northerly central (L∞=197 mm;K=0.324) and southern Chukchi Sea (L∞=221 mm;K=0.297) when compared to the northern Bering Sea (L∞=266 mm;K=0.171), suggesting a possible cline in growth rates with more northerly latitudes. Comparison of growth to two periods separated by 30 years indicate that both species exhibited a decline in maximum size accompanied by higher instantaneous growth rates in more recent years.

Time Dependence of Aerosol Light Scattering Downwind of Forest Fires

NASA Astrophysics Data System (ADS)

Kleinman, L. I.; Sedlacek, A. J., III; Wang, J.; Lewis, E. R.; Springston, S. R.; Chand, D.; Shilling, J.; Arnott, W. P.; Freedman, A.; Onasch, T. B.; Fortner, E.; Zhang, Q.; Yokelson, R. J.; Adachi, K.; Buseck, P. R.

2017-12-01

In the first phase of BBOP (Biomass Burn Observation Project), a Department of Energy (DOE) sponsored study, wildland fires in the Pacific Northwest were sampled from the G-1 aircraft via sequences of transects that encountered emission whose age (time since emission) ranged from approximately 15 minutes to four hours. Comparisons between transects allowed us to determine the near-field time evolution of trace gases, aerosol particles, and optical properties. The fractional increase in aerosol concentration with plume age was typically less than a third of the fractional increase in light scattering. In some fires the increase in light scattering exceeded a factor of two. Two possible causes for the discrepancy between scattering and aerosol mass are i) the downwind formation of refractory tar balls that are not detected by the AMS and therefore contribute to scattering but not to aerosol mass and ii) changes to the aerosol size distribution. Both possibilities are considered. Our information on tar balls comes from an analysis of TEM grids. A direct determination of size changes is complicated by extremely high aerosol number concentrations that caused coincidence problems for the PCASP and UHSAS probes. We instead construct a set of plausible log normal size distributions and for each member of the set do Mie calculations to determine mass scattering efficiency (MSE), angstrom exponents, and backscatter ratios. Best fit size distributions are selected by comparison with observed data derived from multi-wavelength scattering measurements, an extrapolated FIMS size distribution, and mass measurements from an SP-AMS. MSE at 550 nm varies from a typical near source value of 2-3 to about 4 in aged air.

Age-related effects of body mass on fertility and litter size in roe deer.

PubMed

Flajšman, Katarina; Jerina, Klemen; Pokorny, Boštjan

2017-01-01

We analysed effects of females' body mass and age on reproductive capacity of European roe deer (Capreolus capreolus) in a large sample set of 1312 females (305 yearlings and 1007 adults), hunted throughout Slovenia, central Europe, in the period 2013-2015. Body mass positively affected probability of ovulation and potential litter size (number of corpora lutea), although its effect was more pronounced in yearlings than in adults. Between age groups, we found clear differences in responses of both reproductive parameters to body mass which influences primarily reproductive performance of younger, and in particular, lighter individuals: at the same body mass yearlings would at average have smaller litters than adults, and at lower body mass also young to middle-aged adults would have smaller litters than old ones. In addition, while yearlings have to reach a critical threshold body mass to attain reproductive maturity, adult females are fertile (produce ova) even at low body mass. However, at higher body mass also younger individuals shift their efforts into the reproduction, and after reaching an age-specific threshold the body mass does not have any further effects on the reproductive output of roe deer females. Increased reproductive capacity at more advanced age, combined with declining body mass suggests that old does allocate more of their resources in reproduction than in body condition.

Age-related effects of body mass on fertility and litter size in roe deer

PubMed Central

Jerina, Klemen; Pokorny, Boštjan

2017-01-01

We analysed effects of females’ body mass and age on reproductive capacity of European roe deer (Capreolus capreolus) in a large sample set of 1312 females (305 yearlings and 1007 adults), hunted throughout Slovenia, central Europe, in the period 2013–2015. Body mass positively affected probability of ovulation and potential litter size (number of corpora lutea), although its effect was more pronounced in yearlings than in adults. Between age groups, we found clear differences in responses of both reproductive parameters to body mass which influences primarily reproductive performance of younger, and in particular, lighter individuals: at the same body mass yearlings would at average have smaller litters than adults, and at lower body mass also young to middle-aged adults would have smaller litters than old ones. In addition, while yearlings have to reach a critical threshold body mass to attain reproductive maturity, adult females are fertile (produce ova) even at low body mass. However, at higher body mass also younger individuals shift their efforts into the reproduction, and after reaching an age-specific threshold the body mass does not have any further effects on the reproductive output of roe deer females. Increased reproductive capacity at more advanced age, combined with declining body mass suggests that old does allocate more of their resources in reproduction than in body condition. PMID:28403161

Cognitive development in children up to age 11 years born after ART-a longitudinal cohort study.

PubMed

Barbuscia, Anna; Mills, Melinda C

2017-07-01

How does the cognitive development of children conceived after ART (IVF and ICSI) - measured as cognitive skills at age 3, 5, 7 and 11 years - differ over time from those born after natural conception (NC)? Improved measures of cognitive development up to age 5 years were recorded in children conceived with ART compared to NC, which attenuates by 11 years, with ART children still scoring slightly better than NC children. Results on the cognitive outcomes of children conceived after ART have been highly contradictory. Some have shown that ART children have an impaired behavioural, socio-emotional and cognitive development and higher risk of mental disorders. Others have reported no increased risk or difference. Cognitive development has not been previously examined using latent growth curve models from ages 3 to 11 years, also including appropriate attention to confounding parental characteristics. Longitudinal data for the first five waves (2000-2012) of the UK Millennium Cohort Study were used, which is a two-stage sample of all infants born in 2000-2001 and resident in the UK at 9 months of age, drawn from the Department of Social Security Child Benefit Registers. A final sample of N = 15 218 children (125 IVF and 61 ICSI), from 14 816 families was used. Information was available for all waves for 8298 children. Four additional follow-up surveys were conducted in 2003, 2005, 2007 and 2012. Our sample includes children born within a union (married or cohabiting parents) and where information on cognitive scores was available for at least two measurement points. Cognitive development was assessed with the British Ability Scales. At age 3 and 5 years (wave 2 and 3), children completed the naming vocabulary component, which measures expressive verbal ability. At age 7 years (wave 4), verbal cognitive abilities were assessed through the word reading test, and at age 11 years (wave 5) through a verbal similarity test. Two-tailed Student's t-tests examined differences between ART and NC groups. Growth curve models (random-coefficient, latent trajectory models) were used to study the effect of ART, confounding parental characteristics and health outcomes at birth, both at a baseline level of cognitive ability at age 3 years and on its growth rate. At age 3 and 5 years, children conceived with the aid of ART have higher verbal cognitive abilities than NC children (P < 0.001) but this consistently decreases over time and diminishes by age 11 years. Parental environment and resources are pivotal in children's cognitive development. The sample size of the ART cohort of children is small across each time period (N = 150-180) in comparison with NC children (N = 10 496-11 955). Owing to a limited sample size, we are also unable to compare IVF versus ICSI treatment. With the increasing use of IVF and ICSI, these results indicate that there are no detrimental effects on children's early cognitive outcomes up to age 11 years, and highlight the importance of parental characteristics. Funding for this project was provided by the European Union's Seventh Framework Program (FP7 2007-2013) (No. 320116 Families and Societies), ESRC/NCRM SOCGEN Grant (ES/N0011856/1) and the SOCIOGENOME ERC Consolidator Grant (ERC-2013-CoG-615603) (to M.C.M.). The authors have no competing interests to declare. N/A. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

Bacterial Presence in Layered Rock Varnish-Possible Mars Analog?

NASA Astrophysics Data System (ADS)

Krinsley, D.; Rusk, B. G.

2000-08-01

Rock varnish from locations in Death Valley, California; Peru; Antarctica; and Hawaii reveal nanometer scale layering (less than 1 nm to about 75 nm) when studied with transmission electron microscopy (TEM). Parallel layers of clay minerals containing evidence of presumed bacteria were present in all samples. Samples range in age from a few thousand years to perhaps a million years. Diagenesis is relatively limited, as chemical composition is variable, both from top to bottom and along layers in these varnish samples. Also, occasional exotic minerals occur randomly in most varnish sections, and vary in size and hardness, again suggesting relative lack of diagenetic alteration. Additional information can be found in the original extended abstract.

How Thinking About the Donor Influences Post-traumatic Growth in Liver Transplant Recipients.

PubMed

Martín-Rodríguez, A; Pérez-San-Gregorio, M Á; Avargues-Navarro, M L; Borda-Mas, M; Pérez-Bernal, J; Gómez-Bravo, M Á

2018-03-01

The aim of this work was to find out whether thinking frequently about the donor influences post-traumatic growth of liver transplant recipients. The sample of 240 patients selected was made up of 185 men and 55 women with an overall mean age of 60.21 (SD 9.3) years. All of them had received liver transplants from cadaver donors. Transplant recipients were asked whether they thought frequently about the donor (yes or no) and filled out the Post-traumatic Growth Inventory. The t test for unpaired samples was applied to analyze how thinking frequently about the donor or not influenced post-traumatic growth. We also calculated the effect sizes by means of Cohen d or Cohen w depending on the nature of the variables analyzed (quantitative or qualitative). The liver transplant recipients who thought frequently about the donor, compared with those who did not, had higher total scores on post-traumatic growth (P = .000; d = 0.57; medium effect size). Furthermore, considering the effect sizes, the differences between the subgroups were more relevant on the following subscales: new possibilities (P = .000; d = 0.53; medium effect size), appreciation of life (P = .000; d = 0.60; medium effect size), and spiritual change (P = .000; d = 0.54; medium effect size). Patients who think frequently about the donor have more post-traumatic growth than those who do not. Copyright © 2017 Elsevier Inc. All rights reserved.

Small renal size in newborns with spina bifida: possible causes.

PubMed

Montaldo, Paolo; Montaldo, Luisa; Iossa, Azzurra Concetta; Cennamo, Marina; Caredda, Elisabetta; Del Gado, Roberto

2014-02-01

Previous studies reported that children with neural tube defects, but without any history of intrinsic renal diseases, have small kidneys when compared with age-matched standard renal growth. The aim of this study was to investigate the possible causes of small renal size in children with spina bifida by comparing growth hormone deficiency, physical limitations and hyperhomocysteinemia. The sample included 187 newborns with spina bifida. Renal sizes in the patients were assessed by using maximum measurement of renal length and the measurements were compared by using the Sutherland monogram. According to the results, the sample was divided into two groups--a group of 120 patients with small kidneys (under the third percentile) and a control group of 67 newborns with normal kidney size. Plasma total homocysteine was investigated in mothers and in their children. Serum insulin-like growth factor-1 (IGF-1) levels were measured. Serum IGF-1 levels were normal in both groups. Children and mothers with homocysteine levels >10 μmol/l were more than twice as likely to have small kidneys and to give to birth children with small kidneys, respectively, compared with newborns and mothers with homocysteine levels <10 μmol/l. An inverse correlation was also found between the homocysteine levels of mothers and kidney sizes of children (r = - 0.6109 P ≤ 0.01). It is highly important for mothers with hyperhomocysteinemia to be educated about benefits of folate supplementation in order to reduce the risk of small renal size and lower renal function in children.

[Study on the resilience internal factors in a sample of Puerto Rican centenarians].

PubMed

Rosado-Medina, José J; Rodríguez-Gómez, José R; Altieri-Ramirez, Gladys

2012-01-01

Old age is a stage that is usually characterized by lost at the physiological, psychological and social level that generates much distress to individuals. However, the centenaries have been identified as an example of successful aging, within other factors, because they have adequate managed skills that help them to deal with healthy normal losses. Resilience could be one of the factors that may help the Centennials to age successfully. It is necessary more studies with Puerto Rico Centennials since we lack such investigations. This study has an expo facto design; in addition we evaluate psychometrically the Symptoms Check List 90-R (SCL-90-R). The scale of Internal Resilience Factors (EFIR), a semi structured interview and the SCL-90-R were used to identify factors associated with successful aging in the centennials. In addition we explore if there exist gender differences in internal factors of resilience within the sample. 23 Centennials, 15 men and 8 women, of different parts of Puerto Rico (average age = 101. 5 years). Internal resilience factors associated with the aging process were identifying, those were: emotional stability, optimism, behavioral factor and behavioral and emotional skills component. These factors are consistent with the revised literature on positive emotions and adaptive ageing. On the other hand, no statistically significant difference was identified (p <. 05) for the internal factors of resilience on the basis of gender, a finding agreed with the revised literature. The multiple tests administered showed adequate internal consistency (EFIR: (=. 726); SCL-90-R: (=. 941). The Symptoms Check list 90-R (SCL-90-R) was valid with a Cronbach's alpha of. 941. We identified internal resilience factors that could be linked with successfully aging: those factors are encouraging the elderly population. In addition used tests showed adequate internal consistency. Limitations in relation to the size of the sample and the distribution of gender were identified, thus we suggest further research with larger samples.

Plasma asymmetric dimethylarginine, L-arginine and Left Ventricular Structure and Function in a Community-based Sample

PubMed Central

Lieb, Wolfgang; Benndorf, Ralf A.; Benjamin, Emelia J.; Sullivan, Lisa M.; Maas, Renke; Xanthakis, Vanessa; Schwedhelm, Edzard; Aragam, Jayashri; Schulze, Friedrich; Böger, Rainer H.; Vasan, Ramachandran S.

2009-01-01

Objective Increasing evidence indicates that cardiac structure and function are modulated by the nitric oxide (NO) system. Elevated plasma concentrations of asymmetric dimethylarginine (ADMA; a competitive inhibitor of NO synthase) have been reported in patients with end-stage renal disease. It is unclear if circulating ADMA and L-arginine levels are related to cardiac structure and function in the general population. Methods We related plasma ADMA and L-Arginine (the amino acid precursor of NO) to echocardiographic left ventricular (LV) mass, left atrial (LA) size and fractional shortening (FS) using multivariable linear regression analyses in 1,919 Framingham Offspring Study participants (mean age 57 years, 58 % women). Results Overall, neither ADMA or L-arginine, nor their ratio was associated with LV mass, LA size and FS in multivariable models (p>0.10 for all). However, we observed effect modification by obesity of the relations of ADMA and LA size (p for interaction p=0.04): ADMA was positively related to LA size in obese individuals (adjusted-p=0.0004 for trend across ADMA quartiles) but not in non-obese people. Conclusion In our large community-based sample, plasma ADMA and L-arginine concentrations were not related to cardiac structure or function. The observation of positive relations of LA size and ADMA in obese individuals warrants confirmation. PMID:18829028

Analysis of intrinsic and extrinsic factors influencing the dynamics of bovine Eimeria spp. from central-eastern Poland.

PubMed

Tomczuk, Krzysztof; Grzybek, Maciej; Szczepaniak, Klaudiusz; Studzińska, Maria; Demkowska-Kutrzepa, Marta; Roczeń-Karczmarz, Monika; Klockiewicz, Maciej

2015-11-30

Eimeria infections are common in cattle worldwide, however, little is known about the invasion dynamics of this unicellular parasite. Therefore, the aim of this study was to analyze intrinsic (host age) and extrinsic (herd size and management system) factors influencing the dynamics of Eimeria spp. found in calves from CE Poland. Fecal samples were collected from 356 calves from different types of management systems and from different herd sizes. Flotation and McMaster method were used for parasitological investigation. Oocysts were differentiated on the basis of morphological criteria. Eight Eimeria species were identified and mean species richness (MSR) was significantly affected by host age. The highest MSR was noted for middle age animals. There was an association between species, with a highly significant co-occurrence of Eimeria bovis with Eimeria zuernii. The presence of E. bovis significantly increased the percentage of individuals carrying E. zuernii. The presence of E. bovis significantly increased the percentage of individuals carrying Eimeria canadensis. The overall prevalence of Eimeria spp. reached 52.8% and was significantly affected by the age of cows, with the highest prevalence in animals between 5-10 months old. The most prevalent species were E. bovis (37.4%), E. zuernii (19.9%) and E. canadensis (12.1%). The prevalence of E. bovis was affected by host age (the highest prevalence in age class 2 animals) and management type (the highest prevalence in individuals raised in groups). The prevalence of E. zuernii was affected by age (the lowest prevalence was noted in the oldest individuals) and herd size (individuals infected were present only in the middle and large size herds), whereas the prevalence of E. canadensis was affected by all three factors. Overall, mean OPG of the combined Eimeria spp. was 458.84 (37.93) and differed significantly between age classes. Mean OPGs were generally low for young and mature animals but high for middle age class animals. There was no significant influence of extrinsic factors on OPG. Taking into consideration the presented results, it is necessary to underline the role of intrinsic and extrinsic factors affecting the prevalence and abundance of Eimeria spp. in calves. Understanding the dynamics of Eimeria infections in calves may help to overcome this most common bovine parasite. Copyright © 2015 Elsevier B.V. All rights reserved.

Age-Related Differences in Muscle Fatigue Vary by Contraction Type: A Meta-analysis

PubMed Central

Avin, Keith G.

2011-01-01

Background During senescence, despite the loss of strength (force-generating capability) associated with sarcopenia, muscle endurance may improve for isometric contractions. Purpose The purpose of this study was to perform a systematic meta-analysis of young versus older adults, considering likely moderators (ie, contraction type, joint, sex, activity level, and task intensity). Data Sources A 2-stage systematic review identified potential studies from PubMed, CINAHL, PEDro, EBSCOhost: ERIC, EBSCOhost: Sportdiscus, and The Cochrane Library. Study Selection Studies reporting fatigue tasks (voluntary activation) performed at a relative intensity in both young (18–45 years of age) and old (≥55 years of age) adults who were healthy were considered. Data Extraction Sample size, mean and variance outcome data (ie, fatigue index or endurance time), joint, contraction type, task intensity (percentage of maximum), sex, and activity levels were extracted. Data Synthesis Effect sizes were (1) computed for all data points; (2) subgrouped by contraction type, sex, joint or muscle group, intensity, or activity level; and (3) further subgrouped between contraction type and the remaining moderators. Out of 3,457 potential studies, 46 publications (with 78 distinct effect size data points) met all inclusion criteria. Limitations A lack of available data limited subgroup analyses (ie, sex, intensity, joint), as did a disproportionate spread of data (most intensities ≥50% of maximum voluntary contraction). Conclusions Overall, older adults were able to sustain relative-intensity tasks significantly longer or with less force decay than younger adults (effect size=0.49). However, this age-related difference was present only for sustained and intermittent isometric contractions, whereas this age-related advantage was lost for dynamic tasks. When controlling for contraction type, the additional modifiers played minor roles. Identifying muscle endurance capabilities in the older adult may provide an avenue to improve functional capabilities, despite a clearly established decrement in peak torque. PMID:21616932

Characterization of Large Structural Genetic Mosaicism in Human Autosomes

PubMed Central

Machiela, Mitchell J.; Zhou, Weiyin; Sampson, Joshua N.; Dean, Michael C.; Jacobs, Kevin B.; Black, Amanda; Brinton, Louise A.; Chang, I-Shou; Chen, Chu; Chen, Constance; Chen, Kexin; Cook, Linda S.; Crous Bou, Marta; De Vivo, Immaculata; Doherty, Jennifer; Friedenreich, Christine M.; Gaudet, Mia M.; Haiman, Christopher A.; Hankinson, Susan E.; Hartge, Patricia; Henderson, Brian E.; Hong, Yun-Chul; Hosgood, H. Dean; Hsiung, Chao A.; Hu, Wei; Hunter, David J.; Jessop, Lea; Kim, Hee Nam; Kim, Yeul Hong; Kim, Young Tae; Klein, Robert; Kraft, Peter; Lan, Qing; Lin, Dongxin; Liu, Jianjun; Le Marchand, Loic; Liang, Xiaolin; Lissowska, Jolanta; Lu, Lingeng; Magliocco, Anthony M.; Matsuo, Keitaro; Olson, Sara H.; Orlow, Irene; Park, Jae Yong; Pooler, Loreall; Prescott, Jennifer; Rastogi, Radhai; Risch, Harvey A.; Schumacher, Fredrick; Seow, Adeline; Setiawan, Veronica Wendy; Shen, Hongbing; Sheng, Xin; Shin, Min-Ho; Shu, Xiao-Ou; VanDen Berg, David; Wang, Jiu-Cun; Wentzensen, Nicolas; Wong, Maria Pik; Wu, Chen; Wu, Tangchun; Wu, Yi-Long; Xia, Lucy; Yang, Hannah P.; Yang, Pan-Chyr; Zheng, Wei; Zhou, Baosen; Abnet, Christian C.; Albanes, Demetrius; Aldrich, Melinda C.; Amos, Christopher; Amundadottir, Laufey T.; Berndt, Sonja I.; Blot, William J.; Bock, Cathryn H.; Bracci, Paige M.; Burdett, Laurie; Buring, Julie E.; Butler, Mary A.; Carreón, Tania; Chatterjee, Nilanjan; Chung, Charles C.; Cook, Michael B.; Cullen, Michael; Davis, Faith G.; Ding, Ti; Duell, Eric J.; Epstein, Caroline G.; Fan, Jin-Hu; Figueroa, Jonine D.; Fraumeni, Joseph F.; Freedman, Neal D.; Fuchs, Charles S.; Gao, Yu-Tang; Gapstur, Susan M.; Patiño-Garcia, Ana; Garcia-Closas, Montserrat; Gaziano, J. Michael; Giles, Graham G.; Gillanders, Elizabeth M.; Giovannucci, Edward L.; Goldin, Lynn; Goldstein, Alisa M.; Greene, Mark H.; Hallmans, Goran; Harris, Curtis C.; Henriksson, Roger; Holly, Elizabeth A.; Hoover, Robert N.; Hu, Nan; Hutchinson, Amy; Jenab, Mazda; Johansen, Christoffer; Khaw, Kay-Tee; Koh, Woon-Puay; Kolonel, Laurence N.; Kooperberg, Charles; Krogh, Vittorio; Kurtz, Robert C.; LaCroix, Andrea; Landgren, Annelie; Landi, Maria Teresa; Li, Donghui; Liao, Linda M.; Malats, Nuria; McGlynn, Katherine A.; McNeill, Lorna H.; McWilliams, Robert R.; Melin, Beatrice S.; Mirabello, Lisa; Peplonska, Beata; Peters, Ulrike; Petersen, Gloria M.; Prokunina-Olsson, Ludmila; Purdue, Mark; Qiao, You-Lin; Rabe, Kari G.; Rajaraman, Preetha; Real, Francisco X.; Riboli, Elio; Rodríguez-Santiago, Benjamín; Rothman, Nathaniel; Ruder, Avima M.; Savage, Sharon A.; Schwartz, Ann G.; Schwartz, Kendra L.; Sesso, Howard D.; Severi, Gianluca; Silverman, Debra T.; Spitz, Margaret R.; Stevens, Victoria L.; Stolzenberg-Solomon, Rachael; Stram, Daniel; Tang, Ze-Zhong; Taylor, Philip R.; Teras, Lauren R.; Tobias, Geoffrey S.; Viswanathan, Kala; Wacholder, Sholom; Wang, Zhaoming; Weinstein, Stephanie J.; Wheeler, William; White, Emily; Wiencke, John K.; Wolpin, Brian M.; Wu, Xifeng; Wunder, Jay S.; Yu, Kai; Zanetti, Krista A.; Zeleniuch-Jacquotte, Anne; Ziegler, Regina G.; de Andrade, Mariza; Barnes, Kathleen C.; Beaty, Terri H.; Bierut, Laura J.; Desch, Karl C.; Doheny, Kimberly F.; Feenstra, Bjarke; Ginsburg, David; Heit, John A.; Kang, Jae H.; Laurie, Cecilia A.; Li, Jun Z.; Lowe, William L.; Marazita, Mary L.; Melbye, Mads; Mirel, Daniel B.; Murray, Jeffrey C.; Nelson, Sarah C.; Pasquale, Louis R.; Rice, Kenneth; Wiggs, Janey L.; Wise, Anastasia; Tucker, Margaret; Pérez-Jurado, Luis A.; Laurie, Cathy C.; Caporaso, Neil E.; Yeager, Meredith; Chanock, Stephen J.

2015-01-01

Analyses of genome-wide association study (GWAS) data have revealed that detectable genetic mosaicism involving large (>2 Mb) structural autosomal alterations occurs in a fraction of individuals. We present results for a set of 24,849 genotyped individuals (total GWAS set II [TGSII]) in whom 341 large autosomal abnormalities were observed in 168 (0.68%) individuals. Merging data from the new TGSII set with data from two prior reports (the Gene-Environment Association Studies and the total GWAS set I) generated a large dataset of 127,179 individuals; we then conducted a meta-analysis to investigate the patterns of detectable autosomal mosaicism (n = 1,315 events in 925 [0.73%] individuals). Restricting to events >2 Mb in size, we observed an increase in event frequency as event size decreased. The combined results underscore that the rate of detectable mosaicism increases with age (p value = 5.5 × 10−31) and is higher in men (p value = 0.002) but lower in participants of African ancestry (p value = 0.003). In a subset of 47 individuals from whom serial samples were collected up to 6 years apart, complex changes were noted over time and showed an overall increase in the proportion of mosaic cells as age increased. Our large combined sample allowed for a unique ability to characterize detectable genetic mosaicism involving large structural events and strengthens the emerging evidence of non-random erosion of the genome in the aging population. PMID:25748358

The single grain fusion dating approach: Determining the factors that control white mica 40Ar/39Ar age formation during HP metamorphism of the Cycladic Blueschist Unit, Greece

NASA Astrophysics Data System (ADS)

Uunk, Bertram; Wijbrans, Jan; Brouwer, Fraukje

2017-04-01

White mica 40Ar/39Ar dating is a proven powerful tool for constraining the timing and rate of metamorphism, deformation and exhumation. However, for high-pressure metamorphic rocks dating often results in wide age ranges, which are not in agreement with constraints from other isotopic systems, indicating that geological and chemical processes complicate straightforward 40Ar/39Ar dating. Despite hosting one of the largest geochronological datasets in the world, the Cycladic Blueschist Unit in Greece is presently one of the focal areas in the discussion on the interpretation of metamorphic 40Ar/39Ar ages. Previous phengite multi grain step heating experiments commonly yielded undulating age spectra ranging between 20 - 60 Ma. While some studies attempt to assign geological significance to these ages, others argue the ages are geologically meaningless and the result of the interplay between partial diffusive resetting and continued crystallization. By taking an alternative approach of multiple single grain fusion experiments, this study investigates age heterogeneity between samples of contrasting metamorphic facies, rheology and strain from the Cycladic islands of Syros and Sifnos. Comparing the size and shape of single grain fusion age distributions at the grain, rock, outcrop and island scale allows determination of the scale at which different age-forming processes operate. Resulting ages show a previously unreported consistent variation between different outcrops, moving from the eclogite-blueschist facies (55-45 Ma) to greenschist overprinting (40-30 Ma). This indicates that outcrop scale homogeneous resetting is the dominant processes for age formation in the CBU. Single grain age variation at the sample and outcrop scale is only limited to 10 Ma, indicating a smaller but observable role for local age perturbing processes of incomplete resetting, continued (re)crystallization or infiltration of excess argon. Some of the partially overprinted samples show homogeneous single grain age populations, indicating at least a partial role for efficient resetting by thermally activated diffusion at the outcrop scale. Traditional multi grain step heating experiments on the same samples yield flat plateaus for various single grain age distributions, indicating that age heterogeneities resolved by single grain fusion dating are mixed to a meaningless average in step heating experiments. In contrast, our approach leads to a better understanding of the processes responsible for age formation during high pressure metamorphism.

Derivation of a Provisional, Age-dependent, AIS2+ Thoracic Risk Curve for the THOR50 Test Dummy via Integration of NASS Cases, PMHS Tests, and Simulation Data.

PubMed

Laituri, Tony R; Henry, Scott; El-Jawahri, Raed; Muralidharan, Nirmal; Li, Guosong; Nutt, Marvin

2015-11-01

A provisional, age-dependent thoracic risk equation (or, "risk curve") was derived to estimate moderate-to-fatal injury potential (AIS2+), pertaining to men with responses gaged by the advanced mid-sized male test dummy (THOR50). The derivation involved two distinct data sources: cases from real-world crashes (e.g., the National Automotive Sampling System, NASS) and cases involving post-mortem human subjects (PMHS). The derivation was therefore more comprehensive, as NASS datasets generally skew towards younger occupants, and PMHS datasets generally skew towards older occupants. However, known deficiencies had to be addressed (e.g., the NASS cases had unknown stimuli, and the PMHS tests required transformation of known stimuli into THOR50 stimuli). For the NASS portion of the analysis, chest-injury outcomes for adult male drivers about the size of the THOR50 were collected from real-world, 11-1 o'clock, full-engagement frontal crashes (NASS, 1995-2012 calendar years, 1985-2012 model-year light passenger vehicles). The screening for THOR50-sized men involved application of a set of newly-derived "correction" equations for self-reported height and weight data in NASS. Finally, THOR50 stimuli were estimated via field simulations involving attendant representative restraint systems, and those stimuli were then assigned to corresponding NASS cases (n=508). For the PMHS portion of the analysis, simulation-based closure equations were developed to convert PMHS stimuli into THOR50 stimuli. Specifically, closure equations were derived for the four measurement locations on the THOR50 chest by cross-correlating the results of matched-loading simulations between the test dummy and the age-dependent, Ford Human Body Model. The resulting closure equations demonstrated acceptable fidelity (n=75 matched simulations, R2≥0.99). These equations were applied to the THOR50-sized men in the PMHS dataset (n=20). The NASS and PMHS datasets were combined and subjected to survival analysis with event-frequency weighting and arbitrary censoring. The resulting risk curve--a function of peak THOR50 chest compression and age--demonstrated acceptable fidelity for recovering the AIS2+ chest injury rate of the combined dataset (i.e., IR_dataset=1.97% vs. curve-based IR_dataset=1.98%). Additional sensitivity analyses showed that (a) binary logistic regression yielded a risk curve with nearly-identical fidelity, (b) there was only a slight advantage of combining the small-sample PMHS dataset with the large-sample NASS dataset, (c) use of the PMHS-based risk curve for risk estimation of the combined dataset yielded relatively poor performance (194% difference), and (d) when controlling for the type of contact (lab-consistent or not), the resulting risk curves were similar.

Comparative metabolomics of aging in a long-lived bat: Insights into the physiology of extreme longevity

PubMed Central

levari-Shariati, Shiva; Cooper, Lisa Noelle; Aliani, Michel

2018-01-01

Vespertilionid bats (Mammalia: Order Chiroptera) live 3–10 times longer than other mammals of an equivalent body size. At present, nothing is known of how bat fecal metabolic profiles shift with age in any taxa. This study established the feasibility of using a non-invasive, fecal metabolomics approach to examine age-related differences in the fecal metabolome of young and elderly adult big brown bats (Eptesicus fuscus) as an initial investigation into using metabolomics for age determination. Samples were collected from captive, known-aged big brown bats (Eptesicus fuscus) from 1 to over 14 years of age: these two ages represent age groups separated by approximately 75% of the known natural lifespan of this taxon. Results showed 41 metabolites differentiated young (n = 22) and elderly (n = 6) Eptesicus. Significant differences in metabolites between young and elderly bats were associated with tryptophan metabolism and incomplete protein digestion. Results support further exploration of the physiological mechanisms bats employ to achieve exceptional longevity. PMID:29715267

The Utility of Discriminant Analysis for Predicting Farmers' Intentions to Participate in Farmer-Managed Irrigation Systems in Iran

NASA Astrophysics Data System (ADS)

Zarafshani, Kiumars; Hossien Alibaygi, Amir; Afshar, Nasrin

Participatory irrigation management has been problematic in most parts of the world and Iran has been no exception. The purpose of this study was to assess farmers' intentions to participate in irrigation management based on selected variables using discriminant analysis. A survey questionnaire was used to collect information from a sample of Water Cooperatives in Javanrood Townships using stratified random sampling (n = 106). Results indicated that age, educational level, attitude towards PIM, irrigation performance, landholding size, agricultural and non-agricultural income affected farmers' intentions to participate in irrigation management.

Characterization-curing-property studies of HBRF 55A resin formulations

NASA Technical Reports Server (NTRS)

Pearce, E. M.; Mijovic, J.

1985-01-01

Characterization curing property investigations on HBRF 55A resin formulations are reported. The initial studies on as received cured samples cut from a full-size FWC are reviewed. Inadequacies of as-received and aged samples are pointed out and additional electron microscopic evidence is offered. Characterization of as-received ingredients of HBRF 55A formulation is described. Specifically, Epon 826, Epon 828, EpiRez 5022, RD-2 and various amines, including Tonox and Tonox 60.40, were characterized. Cure kinetics of various formulations are investigated. Changes in physical/thermal properties (viscosity, specific heat, thermal conductivity and density) during cure are described.

Droplet-size distribution and stability of commercial injectable lipid emulsions containing fish oil.

PubMed

Gallegos, Críspulo; Valencia, Concepción; Partal, Pedro; Franco, José M; Maglio, Omay; Abrahamsson, Malin; Brito-de la Fuente, Edmundo

2012-08-01

The droplet size of commercial fish oil-containing injectable lipid emulsions, including conformance to United States Pharmacopeia (USP) standards on fat-globule size, was investigated. A total of 18 batches of three multichamber parenteral products containing the emulsion SMOFlipid as a component were analyzed. Samples from multiple lots of the products were evaluated to determine compliance with standards on the volume-weighted percentage of fat exceeding 0.05% (PFAT(5)) specified in USP chapter 729 to ensure the physical stability of i.v. lipid emulsions. The products were also analyzed to determine the effects of various storage times (3, 6, 9, and 12 months) and storage temperatures (25, 30, and 40 °C) on product stability. Larger-size lipid particles were quantified via single-particle optical sensing (SPOS). The emulsion's droplet-size distribution was determined via laser light scattering. SPOS and light-scattering analysis demonstrated mean PFAT(5) values well below USP-specified globule-size limits for all the tested products under all study conditions. In addition, emulsion aging at any storage temperature in the range studied did not result in a significant increase of PFAT(5) values, and mean droplet-size values did not change significantly during storage of up to 12 months at temperatures of 25-40 °C. PFAT(5) values were below the USP upper limits in SMOFlipid samples from multiple lots of three multichamber products after up to 12 months of storage at 25 or 30 °C or 6 months of storage at 40 °C.

Children's accuracy of portion size estimation using digital food images: effects of interface design and size of image on computer screen.

PubMed

Baranowski, Tom; Baranowski, Janice C; Watson, Kathleen B; Martin, Shelby; Beltran, Alicia; Islam, Noemi; Dadabhoy, Hafza; Adame, Su-heyla; Cullen, Karen; Thompson, Debbe; Buday, Richard; Subar, Amy

2011-03-01

To test the effect of image size and presence of size cues on the accuracy of portion size estimation by children. Children were randomly assigned to seeing images with or without food size cues (utensils and checked tablecloth) and were presented with sixteen food models (foods commonly eaten by children) in varying portion sizes, one at a time. They estimated each food model's portion size by selecting a digital food image. The same food images were presented in two ways: (i) as small, graduated portion size images all on one screen or (ii) by scrolling across large, graduated portion size images, one per sequential screen. Laboratory-based with computer and food models. Volunteer multi-ethnic sample of 120 children, equally distributed by gender and ages (8 to 13 years) in 2008-2009. Average percentage of correctly classified foods was 60·3 %. There were no differences in accuracy by any design factor or demographic characteristic. Multiple small pictures on the screen at once took half the time to estimate portion size compared with scrolling through large pictures. Larger pictures had more overestimation of size. Multiple images of successively larger portion sizes of a food on one computer screen facilitated quicker portion size responses with no decrease in accuracy. This is the method of choice for portion size estimation on a computer.

How Old is Cone Crater at the Apollo 14 Landing Site?

NASA Astrophysics Data System (ADS)

Hiesinger, Harald; Simon, Ina; van der Bogert, Carolyn H.; Robinson, Mark S.; Plescia, Jeff B.

2015-04-01

The Lunar Reconnaissance Orbiter (LRO) Narrow Angle Cameras (NAC) provides new opportunities to investigate crater size-frequency distributions (CSFDs) on individual geological units at key lunar impact craters. We performed new CSFD measurements for the Copernican-aged Cone crater at the Apollo 14 landing site because it is an anchor point for the lunar cratering chronology at young ages [1-4]. Cone crater (340 m diameter) is located about 1100 m NE of the Apollo 14 landing site on a 90 m high ridge of the Fra Mauro Formation, and exhibits a sharp rim [e.g., 5,6,7]. Samples from Cone crater were collected from four stations (Dg, C1, C2, C') during the Apollo 14 mission [7]. Exposure ages of those samples were used to date the formation of Cone crater. Although there is a considerable range of exposure ages (~12 Ma [8] to ~661 Ma [9]), several studies of Cone crater samples indicate an age of ~25-26 Ma [e.g., 2,10,11]. On the basis of our CSFD measurements we determined an absolute model age (AMA) for Cone crater of ~39 Ma, which is in the range of model ages derived by previous CSFD measurements that vary between ~24 Ma [12] and ~73 Ma [13]. However, we found a wide spread of model ages ranging from ~16 to ~82 Ma for individual areas on the crater ejecta blanket. Like [13], we find that the CSFD measurements on LROC images yield older AMAs than previous CSFDs [e.g., 12]. However, our results are closer to the older CSFDs than to those of [13] and are just within the error bars of [14]. Our derived N(1) = 3.26 x 10-5 km-2 is almost identical to the N(1) = 3.36 x 10-5 km-2 of [15]. Comparing the CSFD results to exposure ages of the returned samples we find somewhat older ages. However, at least two of our count areas produce AMAs that are within the error bars of the exposure ages [e.g., 10]. Six other areas show ages that are within two standard deviations to the exposure ages [e.g., 10]. For two count areas that were directly sampled, we obtained ages that are 10 and 23 Ma older than the exposure ages [e.g., 10]. We find that CSFD measurements performed on the ejecta blanket of Cone crater yield AMAs that agree well with the exposure ages, considering the relatively small count areas and the hummocky nature of the ejecta blanket. However, the AMAs are generally older than the exposure ages, which may be due to the small count area sizes [16], a possibly higher recent impact rate [17], some unidentified secondary craters [13], poor calibration of the production function, or inaccurate exposure ages. [1] Hiesinger et al. (2012) J. Geophys. Res. 117. [2] Stöffler and Ryder (2001) Chronology and Evolution of Mars. [3] Neukum (1983) Habil. thesis, U. of Munich. [4] Neukum et al. (2001) Space Sci. Rev. 96. [5] Swann et al. (1971) Apollo 14 Prelim. Sci. Rep. [6] Carlson (1978) NASA STI/Recon Technical Report. [7] Swann (1977) Washington US Govt. Print. Off. [8] Bhandari et al. (1972) Proc. Lunar Planet. Sci. Conf. 3. [9] Crozaz et al. (1972) Proc. Lunar Planet. Sci. Conf. 3. [10] Arvidson et al. (1975) Moon 13. [11] Stadermann et al. (1991) Geochim. Cosmochim. Acta 55. [12] Moore et al. (1980) Moon and Planets 23. [13] Plescia and Robinson (2011) LPSC 42. [14] Williams et al. (2014) Icarus 235. [15] Robbins (2014) Earth Planet. Sci. Lett. 403. [16] van der Bogert et al. (2015) LPSC 46. [17] McEwen et al. (2015) LPSC 46.

Can a Toy Encourage Lower Calorie Meal Bundle Selection in Children? A Field Experiment on the Reinforcing Effects of Toys on Food Choice.

PubMed

Reimann, Martin; Lane, Kristen

2017-01-01

The goal of this research was to test whether including an inexpensive nonfood item (toy) with a smaller-sized meal bundle (420 calories), but not with the regular-sized meal bundle version (580 calories), would incentivize children to choose the smaller-sized meal bundle, even among children with overweight and obesity. Logistic regression was used to evaluate the effect in a between-subjects field experiment of a toy on smaller-sized meal choice (here, a binary choice between a smaller-sized or regular-sized meal bundles). A random sample of 109 elementary school children from two schools in the Tucson, Arizona metropolitan area (55 females; Mage = 8.53 years, SDage = 2.14; MBMI = 18.30, SDBMI = 4.42) participated. Children's height and weight were measured and body-mass-index (BMI) was calculated, adjusting for age and sex. In our sample, 21 children were considered to be either overweight or obese. Logistic regression was used to evaluate the effect of a toy on smaller-sized meal choice. Results revealed that the inclusion of a toy with a smaller-sized meal, but not with the regular-sized version, predicted smaller-sized meal choice (P < .001), suggesting that children can be incentivized to choose less food when such is paired with a toy. BMI neither moderated nor nullified the effect of toy on smaller-sized meal choice (P = .125), suggesting that children with overweight and obesity can also be incentivized to choose less. This article is the first to suggest that fast-food restaurant chains may well utilize toys to motivate children to choose smaller-sized meal bundles. Our findings may be relevant for consumers, health advocates, policy makers, and marketers who would benefit from a strategy that presents healthier, but still desirable, meal bundle options.

Can a Toy Encourage Lower Calorie Meal Bundle Selection in Children? A Field Experiment on the Reinforcing Effects of Toys on Food Choice

PubMed Central

2017-01-01

The goal of this research was to test whether including an inexpensive nonfood item (toy) with a smaller-sized meal bundle (420 calories), but not with the regular-sized meal bundle version (580 calories), would incentivize children to choose the smaller-sized meal bundle, even among children with overweight and obesity. Logistic regression was used to evaluate the effect in a between-subjects field experiment of a toy on smaller-sized meal choice (here, a binary choice between a smaller-sized or regular-sized meal bundles). A random sample of 109 elementary school children from two schools in the Tucson, Arizona metropolitan area (55 females; Mage = 8.53 years, SDage = 2.14; MBMI = 18.30, SDBMI = 4.42) participated. Children’s height and weight were measured and body-mass-index (BMI) was calculated, adjusting for age and sex. In our sample, 21 children were considered to be either overweight or obese. Logistic regression was used to evaluate the effect of a toy on smaller-sized meal choice. Results revealed that the inclusion of a toy with a smaller-sized meal, but not with the regular-sized version, predicted smaller-sized meal choice (P < .001), suggesting that children can be incentivized to choose less food when such is paired with a toy. BMI neither moderated nor nullified the effect of toy on smaller-sized meal choice (P = .125), suggesting that children with overweight and obesity can also be incentivized to choose less. This article is the first to suggest that fast-food restaurant chains may well utilize toys to motivate children to choose smaller-sized meal bundles. Our findings may be relevant for consumers, health advocates, policy makers, and marketers who would benefit from a strategy that presents healthier, but still desirable, meal bundle options. PMID:28085904

Understanding the role of conscientiousness in healthy aging: where does the brain come in?

PubMed

Patrick, Christopher J

2014-05-01

In reviewing this impressive series of articles, I was struck by 2 points in particular: (a) the fact that the empirically oriented articles focused on analyses of data from very large samples, with the articles by Friedman, Kern, Hampson, and Duckworth (2014) and Kern, Hampson, Goldbert, and Friedman (2014) highlighting an approach to merging existing data sets through use of "metric bridges" to address key questions not addressable through 1 data set alone, and (b) the fact that the articles as a whole included limited mention of neuroscientific (i.e., brain research) concepts, methods, and findings. One likely reason for the lack of reference to brain-oriented work is the persisting gap between smaller sample size lab-experimental and larger sample size multivariate-correlational approaches to psychological research. As a strategy for addressing this gap and bringing a distinct neuroscientific component to the National Institute on Aging's conscientiousness and health initiative, I suggest that the metric bridging approach highlighted by Friedman and colleagues could be used to connect existing large-scale data sets containing both neurophysiological variables and measures of individual difference constructs to other data sets containing richer arrays of nonphysiological variables-including data from longitudinal or twin studies focusing on personality and health-related outcomes (e.g., Terman Life Cycle study and Hawaii longitudinal studies, as described in the article by Kern et al., 2014). (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Using random telephone sampling to recruit generalizable samples for family violence studies.

PubMed

Slep, Amy M Smith; Heyman, Richard E; Williams, Mathew C; Van Dyke, Cheryl E; O'Leary, Susan G

2006-12-01

Convenience sampling methods predominate in recruiting for laboratory-based studies within clinical and family psychology. The authors used random digit dialing (RDD) to determine whether they could feasibly recruit generalizable samples for 2 studies (a parenting study and an intimate partner violence study). RDD screen response rate was 42-45%; demographics matched those in the 2000 U.S. Census, with small- to medium-sized differences on race, age, and income variables. RDD respondents who qualified for, but did not participate in, the laboratory study of parents showed small differences on income, couple conflicts, and corporal punishment. Time and cost are detailed, suggesting that RDD may be a feasible, effective method by which to recruit more generalizable samples for in-laboratory studies of family violence when those studies have sufficient resources. (c) 2006 APA, all rights reserved.

Optimal flexible sample size design with robust power.

PubMed

Zhang, Lanju; Cui, Lu; Yang, Bo

2016-08-30

It is well recognized that sample size determination is challenging because of the uncertainty on the treatment effect size. Several remedies are available in the literature. Group sequential designs start with a sample size based on a conservative (smaller) effect size and allow early stop at interim looks. Sample size re-estimation designs start with a sample size based on an optimistic (larger) effect size and allow sample size increase if the observed effect size is smaller than planned. Different opinions favoring one type over the other exist. We propose an optimal approach using an appropriate optimality criterion to select the best design among all the candidate designs. Our results show that (1) for the same type of designs, for example, group sequential designs, there is room for significant improvement through our optimization approach; (2) optimal promising zone designs appear to have no advantages over optimal group sequential designs; and (3) optimal designs with sample size re-estimation deliver the best adaptive performance. We conclude that to deal with the challenge of sample size determination due to effect size uncertainty, an optimal approach can help to select the best design that provides most robust power across the effect size range of interest. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Body size in early life and risk of breast cancer.

PubMed

Shawon, Md Shajedur Rahman; Eriksson, Mikael; Li, Jingmei

2017-07-21

Body size in early life is inversely associated with adult breast cancer (BC) risk, but it is unclear whether the associations differ by tumor characteristics. In a pooled analysis of two Swedish population-based studies consisting of 6731 invasive BC cases and 28,705 age-matched cancer-free controls, we examined the associations between body size in early life and BC risk. Self-reported body sizes at ages 7 and 18 years were collected by a validated nine-level pictogram (aggregated into three categories: small, medium and large). Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated from multivariable logistic regression models in case-control analyses, adjusting for study, age at diagnosis, age at menarche, number of children, hormone replacement therapy, and family history of BC. Body size change between ages 7 and 18 were also examined in relation to BC risk. Case-only analyses were performed to test whether the associations differed by tumor characteristics. Medium or large body size at age 7 and 18 was associated with a statistically significant decreased BC risk compared to small body size (pooled OR (95% CI): comparing large to small, 0.78 (0.70-0.86), P trend <0.001 and 0.72 (0.64-0.80), P trend <0.001, respectively). The majority of the women (~85%) did not change body size categories between age 7 and 18 . Women who remained medium or large between ages 7 and 18 had significantly decreased BC risk compared to those who remained small. A reduction in body size between ages 7 and 18 was also found to be inversely associated with BC risk (0.90 (0.81-1.00)). No significant association was found between body size at age 7 and tumor characteristics. Body size at age 18 was found to be inversely associated with tumor size (P trend  = 0.006), but not estrogen receptor status and lymph node involvement. For all analyses, the overall inferences did not change appreciably after further adjustment for adult body mass index. Our data provide further support for a strong and independent inverse relationship between early life body size and BC risk. The association between body size at age 18 and tumor size could be mediated by mammographic density.

Rates of decline in Alzheimer disease decrease with age.

PubMed

Holland, Dominic; Desikan, Rahul S; Dale, Anders M; McEvoy, Linda K

2012-01-01

Age is the strongest risk factor for sporadic Alzheimer disease (AD), yet the effects of age on rates of clinical decline and brain atrophy in AD have been largely unexplored. Here, we examined longitudinal rates of change as a function of baseline age for measures of clinical decline and structural MRI-based regional brain atrophy, in cohorts of AD, mild cognitive impairment (MCI), and cognitively healthy (HC) individuals aged 65 to 90 years (total n = 723). The effect of age was modeled using mixed effects linear regression. There was pronounced reduction in rates of clinical decline and atrophy with age for AD and MCI individuals, whereas HCs showed increased rates of clinical decline and atrophy with age. This resulted in convergence in rates of change for HCs and patients with advancing age for several measures. Baseline cerebrospinal fluid densities of AD-relevant proteins, Aβ(1-42), tau, and phospho-tau(181p) (ptau), showed a similar pattern of convergence with advanced age across cohorts, particularly for ptau. In contrast, baseline clinical measures did not differ by age, indicating uniformity of clinical severity at baseline. These results imply that the phenotypic expression of AD is relatively mild in individuals older than approximately 85 years, and this may affect the ability to distinguish AD from normal aging in the very old. Our findings show that inclusion of older individuals in clinical trials will substantially reduce the power to detect disease-modifying therapeutic effects, leading to dramatic increases in required clinical trial sample sizes with age of study sample.

Agglomeration of Luminescent Porous Silicon Nanoparticles in Colloidal Solutions

NASA Astrophysics Data System (ADS)

Herynková, Kateřina; Šlechta, Miroslav; Šimáková, Petra; Fučíková, Anna; Cibulka, Ondřej

2016-08-01

We have prepared colloidal solutions of clusters composed from porous silicon nanoparticles in methanol, water and phosphate-buffered saline (PBS). Even if the size of the nanoclusters is between 60 and 500 nm, due to their highly porous "cauliflower"-like structure, the porous silicon nanoparticles are composed of interconnected nanocrystals having around 2.5 nm in size and showing strong visible luminescence in the orange-red spectral region (centred at 600-700 nm). Hydrophilic behaviour and good solubility of the nanoclusters in water and water-based solutions were obtained by adding hydrogen peroxide into the etching solution during preparation and 16 min long after-bath in hydrogen peroxide. By simple filtration of the solutions with syringe filters, we have extracted smaller nanoclusters with sizes of approx. 60-70 nm; however, these nanoclusters in water and PBS solution (pH neutral) are prone to agglomeration, as was confirmed by zeta potential measurements. When the samples were left at ambient conditions for several weeks, the typical nanocluster size increased to approx. 330-400 nm and then remained stable. However, both freshly filtered and aged samples (with agglomerated porous silicon nanoparticles) of porous silicon in water and PBS solutions can be further used for biological studies or as luminescent markers in living cells.

Composition of hydroponic lettuce: effect of time of day, plant size, and season.

PubMed

Gent, Martin P N

2012-02-01

The diurnal variation of nitrate and sugars in leafy green vegetables may vary with plant size or the ability of plants to buffer the uptake, synthesis, and use of metabolites. Bibb lettuce was grown in hydroponics in a greenhouse and sampled at 3 h intervals throughout one day in August 2007 and another day in November 2008 to determine fresh weight, dry matter, and concentration of nitrate and sugars. Plantings differing in size and age were sampled on each date. The dry/fresh weight ratio increased during the daylight period. This increase was greater for small compared to large plants. On a fresh weight basis, tissue nitrate of small plants was only half that of larger plants. The variation in concentration with time was much less for nitrate than for soluble sugars. Soluble sugars were similar for all plant sizes early in the day, but they increased far more for small compared to large plants in the long days of summer. The greatest yield on a fresh weight basis was obtained by harvesting lettuce at dawn. Although dry matter or sugar content increased later in the day, there is no commercial benefit to delaying harvest as consumers do not buy lettuce for these attributes. Copyright © 2011 Society of Chemical Industry.

Agglomeration of Luminescent Porous Silicon Nanoparticles in Colloidal Solutions.

PubMed

Herynková, Kateřina; Šlechta, Miroslav; Šimáková, Petra; Fučíková, Anna; Cibulka, Ondřej

2016-12-01

We have prepared colloidal solutions of clusters composed from porous silicon nanoparticles in methanol, water and phosphate-buffered saline (PBS). Even if the size of the nanoclusters is between 60 and 500 nm, due to their highly porous "cauliflower"-like structure, the porous silicon nanoparticles are composed of interconnected nanocrystals having around 2.5 nm in size and showing strong visible luminescence in the orange-red spectral region (centred at 600-700 nm). Hydrophilic behaviour and good solubility of the nanoclusters in water and water-based solutions were obtained by adding hydrogen peroxide into the etching solution during preparation and 16 min long after-bath in hydrogen peroxide. By simple filtration of the solutions with syringe filters, we have extracted smaller nanoclusters with sizes of approx. 60-70 nm; however, these nanoclusters in water and PBS solution (pH neutral) are prone to agglomeration, as was confirmed by zeta potential measurements. When the samples were left at ambient conditions for several weeks, the typical nanocluster size increased to approx. 330-400 nm and then remained stable. However, both freshly filtered and aged samples (with agglomerated porous silicon nanoparticles) of porous silicon in water and PBS solutions can be further used for biological studies or as luminescent markers in living cells.

The Consideration of Future Consequences and Health Behaviour: A Meta-Analysis.

PubMed

Murphy, Lisa; Dockray, Samantha

2018-06-14

The aim of this meta-analysis was to quantify the direction and strength of associations between the Consideration of Future Consequences (CFC) scale and intended and actual engagement in three categories of health-related behaviour: health risk, health promotive, and illness preventative/detective behaviour. A systematic literature search was conducted to identify studies that measured CFC and health behaviour. In total, sixty-four effect sizes were extracted from 53 independent samples. Effect sizes were synthesised using a random-effects model. Aggregate effect sizes for all behaviour categories were significant, albeit small in magnitude. There were no significant moderating effects of the length of CFC scale (long vs. short), population type (college students vs. non-college students), mean age, or sex proportion of study samples. CFC reliability and study quality score significantly moderated the overall association between CFC and health risk behaviour only. The magnitude of effect sizes is comparable to associations between health behaviour and other individual difference variables, such as the Big Five personality traits. The findings indicate that CFC is an important construct to consider in research on engagement in health risk behaviour in particular. Future research is needed to examine the optimal approach by which to apply the findings to behavioural interventions.

[Effect sizes, statistical power and sample sizes in "the Japanese Journal of Psychology"].

PubMed

Suzukawa, Yumi; Toyoda, Hideki

2012-04-01

This study analyzed the statistical power of research studies published in the "Japanese Journal of Psychology" in 2008 and 2009. Sample effect sizes and sample statistical powers were calculated for each statistical test and analyzed with respect to the analytical methods and the fields of the studies. The results show that in the fields like perception, cognition or learning, the effect sizes were relatively large, although the sample sizes were small. At the same time, because of the small sample sizes, some meaningful effects could not be detected. In the other fields, because of the large sample sizes, meaningless effects could be detected. This implies that researchers who could not get large enough effect sizes would use larger samples to obtain significant results.

Sample Size Estimation: The Easy Way

ERIC Educational Resources Information Center

Weller, Susan C.

2015-01-01

This article presents a simple approach to making quick sample size estimates for basic hypothesis tests. Although there are many sources available for estimating sample sizes, methods are not often integrated across statistical tests, levels of measurement of variables, or effect sizes. A few parameters are required to estimate sample sizes and…

Cross-seasonal effects on waterfowl productivity: Implications under climate change

USGS Publications Warehouse

Osnas, Erik; Zhao, Qing; Runge, Michael C.; Boomer, G Scott

2016-01-01

Previous efforts to relate winter-ground precipitation to subsequent reproductive success as measured by the ratio of juveniles to adults in the autumn failed to account for increased vulnerability of juvenile ducks to hunting and uncertainty in the estimated age ratio. Neglecting increased juvenile vulnerability will positively bias the mean productivity estimate, and neglecting increased vulnerability and estimation uncertainty will positively bias the year-to-year variance in productivity because raw age ratios are the product of sampling variation, the year-specific vulnerability, and year-specific reproductive success. Therefore, we estimated the effects of cumulative winter precipitation in the California Central Valley and the Mississippi Alluvial Valley on pintail (Anas acuta) and mallard (Anas platyrhnchos) reproduction, respectively, using hierarchical Bayesian methods to correct for sampling bias in productivity estimates and observation error in covariates. We applied the model to a hunter-collected parts survey implemented by the United States Fish and Wildlife Service and band recoveries reported to the United States Geological Survey Bird Banding Laboratory using data from 1961 to 2013. We compared our results to previous estimates that used simple linear regression on uncorrected age ratios from a smaller subset of years in pintail (1961–1985). Like previous analyses, we found large and consistent effects of population size and wetland conditions in prairie Canada on mallard productivity, and large effects of population size and mean latitude of the observed breeding population on pintail productivity. Unlike previous analyses, we report a large amount of uncertainty in the estimated effects of wintering-ground precipitation on pintail and mallard productivity, with considerable uncertainty in the sign of the estimated main effect, although the posterior medians of precipitation effects were consistent with past studies. We found more consistent estimates in the sign of an interaction effect between population size and precipitation, suggesting that wintering-ground precipitation has a larger effect in years of high population size, especially for pintail. When we used the estimated effects in a population model to derive a sustainable harvest and population size projection (i.e., a yield curve), there was considerable uncertainty in the effect of increased or decreased wintering-ground precipitation on sustainable harvest potential and population size. These results suggest that the mechanism of cross-seasonal effects between winter habitat and reproduction in ducks occurs through a reduction in the strength of density dependence in years of above-average wintering-ground precipitation. We suggest additional investigation of the underlying mechanisms and that habitat managers and decision-makers consider the level of uncertainty in these estimates when attempting to integrate habitat management and harvest management decisions. Collection of annual data on the status of wintering-ground habitat in a rigorous sampling framework would likely be the most direct way to improve understanding of mechanisms and inform management.

The Relationship between Sample Sizes and Effect Sizes in Systematic Reviews in Education

ERIC Educational Resources Information Center

Slavin, Robert; Smith, Dewi

2009-01-01

Research in fields other than education has found that studies with small sample sizes tend to have larger effect sizes than those with large samples. This article examines the relationship between sample size and effect size in education. It analyzes data from 185 studies of elementary and secondary mathematics programs that met the standards of…

Fast wettability transition from hydrophilic to superhydrophobic laser-textured stainless steel surfaces under low-temperature annealing

NASA Astrophysics Data System (ADS)

Ngo, Chi-Vinh; Chun, Doo-Man

2017-07-01

Recently, the fabrication of superhydrophobic metallic surfaces by means of pulsed laser texturing has been developed. After laser texturing, samples are typically chemically coated or aged in ambient air for a relatively long time of several weeks to achieve superhydrophobicity. To accelerate the wettability transition from hydrophilicity to superhydrophobicity without the use of additional chemical treatment, a simple annealing post process has been developed. In the present work, grid patterns were first fabricated on stainless steel by a nanosecond pulsed laser, then an additional low-temperature annealing post process at 100 °C was applied. The effect of 100-500 μm step size of the textured grid upon the wettability transition time was also investigated. The proposed post process reduced the transition time from a couple of months to within several hours. All samples showed superhydrophobicity with contact angles greater than 160° and sliding angles smaller than 10° except samples with 500 μm step size, and could be applied in several potential applications such as self-cleaning and control of water adhesion.

Characterization of size-resolved urban haze particles collected in summer and winter at Taiyuan City, China using quantitative electron probe X-ray microanalysis

NASA Astrophysics Data System (ADS)

Geng, Hong; Jin, Chun-Song; Zhang, Dong-Peng; Wang, Shu-Rong; Xu, Xiao-Tian; Wang, Xu-Ran; Zhang, Yuan; Wu, Li; Ro, Chul-Un

2017-07-01

The aim of the study is to characterize the size-resolved urban haze particles and investigate their modification in morphology and composition in summer and winter using the semi-quantitative electron probe X-ray microanalysis (EPMA) based on both scanning and transmission electron microscopies equipped with ultrathin-window energy dispersive X-ray spectrometers (SEM-EDX and TEM-EDX). The haze and non-haze particles were collected through a seven-stage May cascade impactor on Dec. 29-30, 2009 and Jan. 8-9 and July 11-14, 2010 in Taiyuan, a typical inland city in the North China Plain. Approximately 3752 atmospheric particles in the size ranges of 4-2 μm, 2-1 μm, 1-0.5 μm, and 0.5-0.25 μm in aerodynamic diameter were measured and identified according to their secondary electron or TEM images and elemental atomic concentrations calculated through a Monte Carlo simulation program. Results show that on the haze days many reacted or aged mineral dust particles were encountered, in which the sulfate-containing ones outnumbered the nitrate-containing ones in the winter samples while it was on the contrary in the summer samples, suggesting different haze formation and evolution mechanisms in summer and winter. Furthermore, in the haze events (especially in summer), many CNOS-rich particles, likely mixtures of water-soluble organic carbon with (NH4)2SO4 or NH4HSO4, were observed not only in the submicron but also in the super-micron fractions. The simultaneous observation of the fresh and aged CNOS-rich particles in the same SEM or TEM images implied that the status and components of secondary particles were complicated and changeable. The significant increase of both elemental concentration ratios of [N]/[S] and [C]/[S] in the aged ones compared to the fresh ones indicated that NH4NO3 and secondary organic matter were likely absorbed onto (NH4)2SO4 or NH4HSO4 particles and mixed with them. K-rich, Fe-rich, and heavy metal-containing particles in TEM-EDX measurement were detected more in the winter haze samples than in the summer ones, suggesting that they tend to be smaller in size and mainly derive from anthropogenic biomass burning and coal combustion. It was concluded that the combined use of SEM-EDX and TEM-EDX can identify both submicron and super-micron urban haze particles in a straightforward way and trace their modifications in size, shape, mixing state, and chemical compositions in different seasons, helping address their evolution processes and hazards on human health.

Body mass index in a US national sample of Asian Americans: effects of nativity, years since immigration and socioeconomic status.

PubMed

Lauderdale, D S; Rathouz, P J

2000-09-01

To examine body mass index (BMI) and the proportion overweight and obese among adults age 18-59 in the six largest Asian American ethnic groups (Chinese, Filipino, Asian Indian, Japanese, Korean, Vietnamese), and investigate whether BMI varies by nativity (foreign-vs native-born), years in US, or socioeconomic status. Cross-sectional interview data were pooled from the 1992-1995 National Health Interview Survey (NHIS). 254,153 persons aged 18-59 included in the 1992-1995 NHIS. Sample sizes range from 816 to 1940 for each of six Asian American ethnic groups. Self-reported height and weight used to calculate BMI and classify individuals as overweight (BMI > or = 25 kg/m2) or obese (BMI > or = 30 kg/m2), age, sex, years in the US, household income and household size. For men, the percentage overweight ranges from 17% of Vietnamese to 42% of Japanese, while the total male population is 57% overweight. For women, the percentage overweight ranges from 9% of Vietnamese and Chinese to 25% of Asian Indians, while the total female population is 38% overweight. The percentage of Asian Americans classified as obese is very low. Adjusted for age and ethnicity, the odds ratio for obese is 3.5 for women and 4.0 for men for US-vs foreign-born. Among the foreign-born, more years in the US is associated with higher risk of being overweight or obese. The association between household income for women is similar for US-born Asian Americans and Whites and Blacks, but is much weaker for foreign-born Asian Americans. While these data find low proportions of Asian Americans overweight at present, they also imply the proportion will increase with more US-born Asian Americans and longer duration in the US.

Maturity status of youth football players: a noninvasive estimate.

PubMed

Malina, Robert M; Cumming, Sean P; Morano, Peter J; Barron, Mary; Miller, Susan J

2005-06-01

To estimate the biological maturity status of youth football players 9-14 yr old using a noninvasive method and to compare the body size of players of contrasting status. Subjects were members of youth football teams in two central Michigan communities. Height and weight were measured on 653 boys 8.7-14.6 yr. Heights of biological parents of 582 boys were reported and subsequently adjusted for overestimation. Decimal age, height, and weight of the player and midparent height were used to predict mature (adult) height for the boy. Current height of each player was expressed as a percentage of his predicted mature height to provide an estimate of biological maturity status. Percentage of predicted mature height of each boy was expressed as a z-score to classify players into maturity groups. ANCOVA, controlling for age, was used to compare body size in contrasting maturity groups. Mean percentages of predicted mature height of the players matched those of longitudinal reference samples, but there was a trend for higher percentages among older players, suggesting advanced maturation. Overall, 405 boys were classified as on time/average in maturity status (69.6% [95%CI 65.7-73.3]), 154 were classified as early/advanced (25.5% [95%CI 23.0-30.3]), and only 23 were classified as late/delayed (3.9% [95%CI 2.6-6.0]). The gradient for height, weight, and BMI was as follows: early > on time > late, and differences were greater for weight and the BMI than for height. Percentage of predicted mature height attained at a given age appears to be a reasonable indicator of maturity status. The method needs to be validated with other more direct indicators (skeletal age, sexual maturation) and applied to other samples.

Age, size, and position of H ii regions in the Galaxy. Expansion of ionized gas in turbulent molecular clouds

NASA Astrophysics Data System (ADS)

Tremblin, P.; Anderson, L. D.; Didelon, P.; Raga, A. C.; Minier, V.; Ntormousi, E.; Pettitt, A.; Pinto, C.; Samal, M. R.; Schneider, N.; Zavagno, A.

2014-08-01

Aims: This work aims to improve the current understanding of the interaction between H ii regions and turbulent molecular clouds. We propose a new method to determine the age of a large sample of OB associations by investigating the development of their associated H ii regions in the surrounding turbulent medium. Methods: Using analytical solutions, one-dimensional (1D), and three-dimensional (3D) simulations, we constrained the expansion of the ionized bubble depending on the turbulence level of the parent molecular cloud. A grid of 1D simulations was then computed in order to build isochrone curves for H ii regions in a pressure-size diagram. This grid of models allowed us to date a large sample of OB associations that we obtained from the H ii Region Discovery Survey (HRDS). Results: Analytical solutions and numerical simulations showed that the expansion of H ii regions is slowed down by the turbulence up to the point where the pressure of the ionized gas is in a quasi-equilibrium with the turbulent ram pressure. Based on this result, we built a grid of 1D models of the expansion of H ii regions in a profile based on Larson's laws. We take the 3D turbulence into account with an effective 1D temperature profile. The ages estimated by the isochrones of this grid agree well with literature values of well known regions such as Rosette, RCW 36, RCW 79, and M 16. We thus propose that this method can be used to find ages of young OB associations through the Galaxy and also in nearby extra-galactic sources.

Life-history traits of the long-nosed skate Dipturus oxyrinchus.

PubMed

Bellodi, A; Porcu, C; Cannas, R; Cau, Al; Marongiu, M F; Mulas, A; Vittori, S; Follesa, M C

2017-03-01

This work investigates life-history traits of the long-nosed skate Dipturus oxyrinchus, which is a common by-catch in Sardinian waters. The reproductive variables were analysed from 979 specimens sampled during scientific and commercial hauls. Females (10·4-117·5 cm total length, L T ) attained larger sizes than males (14·5-99·5 cm L T ). To evaluate age and growth, a sub-sample of 130 individuals (76 females and 54 males) were used. The age was estimated by annuli counts of sectioned vertebral centra. Four models were used for the length-at-age data: the von Bertalanffy, the exponential, the Gompertz and the logistic functions. According to the Akaike's information criterion, the Gompertz model seemed to provide the best fitting curve (L ∞ mean ± s.e.: 127·55 ± 4·90 cm, k: 0·14 ± 0·09, IP: 3·97 ± 0·90 years). The oldest female and male were aged 17 (115·5 cm L T ) and 15 years (96·0 cm L T ), respectively. Lengths at maturity were 103·5 cm for females and 91·0 cm for males, corresponding to 90% of the maximum observed length in both sexes. The monthly distribution of maturity stages highlighted an extended reproductive cycle, with spawning females and active males being present almost throughout the year, as confirmed by the gonado-somatic index. Ovarian fecundity reached a maximum of 26 yolked follicles with a mean ± s.e. size of 19·7 ± 6·5 mm. © 2016 The Fisheries Society of the British Isles.

Phylogenetic effective sample size.

PubMed

Bartoszek, Krzysztof

2016-10-21

In this paper I address the question-how large is a phylogenetic sample? I propose a definition of a phylogenetic effective sample size for Brownian motion and Ornstein-Uhlenbeck processes-the regression effective sample size. I discuss how mutual information can be used to define an effective sample size in the non-normal process case and compare these two definitions to an already present concept of effective sample size (the mean effective sample size). Through a simulation study I find that the AICc is robust if one corrects for the number of species or effective number of species. Lastly I discuss how the concept of the phylogenetic effective sample size can be useful for biodiversity quantification, identification of interesting clades and deciding on the importance of phylogenetic correlations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Highly precise Re-Os dating for molybdenite using alkaline fusion and NTIMS.

PubMed

Markey, R; Stein, H; Morgan, J

1998-03-01

The technique described in this paper represents the modification and combination of two previously existing methods, alkaline fusion and negative thermal ion mass spectrometry (NTIMS). We have used this technique to analyze repeatedly a homogeneous molybdenite powder used as a reference standard in our laboratory. Analyses were made over a period of 18 months, using four different calibrations of two different spike solutions. The age of this standard reproduces at a level of +/-0.13%. Each individual age analysis carries an uncertainty of about 0.4% that includes the uncertainty in the decay constant for (187)Re. This new level of resolution has allowed us to recognize real differences in ages for two grain-size populations of molybdenite from some Archean samples.

Highly precise Re-Os dating for molybdenite using alkaline fusion and NTIMS

USGS Publications Warehouse

Markey, R.; Stein, H.; Morgan, J.

1998-01-01

The technique described in this paper represents the modification and combination of two previously existing methods, alkaline fusion and negative thermal ion mass spectrometry (NTIMS). We have used this technique to analyze repeatedly a homogeneous molybdenite powder used as a reference standard in our laboratory. Analyses were made over a period of 18 months, using four different calibrations of two different spike solutions. The age of this standard reproduces at a level of ?? 0.13%. Each individual age analysis carries an uncertainty of about 0.4% that includes the uncertainty in the decay constant for 187Re. This new level of resolution has allowed us to recognize real differences in ages for two grain-size populations of molybdenite from some Archean samples.

The interaction of glottal-pulse rate and vocal-tract length in judgements of speaker size, sex, and age

NASA Astrophysics Data System (ADS)

Smith, David R. R.; Patterson, Roy D.

2005-11-01

Glottal-pulse rate (GPR) and vocal-tract length (VTL) are related to the size, sex, and age of the speaker but it is not clear how the two factors combine to influence our perception of speaker size, sex, and age. This paper describes experiments designed to measure the effect of the interaction of GPR and VTL upon judgements of speaker size, sex, and age. Vowels were scaled to represent people with a wide range of GPRs and VTLs, including many well beyond the normal range of the population, and listeners were asked to judge the size and sex/age of the speaker. The judgements of speaker size show that VTL has a strong influence upon perceived speaker size. The results for the sex and age categorization (man, woman, boy, or girl) show that, for vowels with GPR and VTL values in the normal range, judgements of speaker sex and age are influenced about equally by GPR and VTL. For vowels with abnormal combinations of low GPRs and short VTLs, the VTL information appears to decide the sex/age judgement.

An Investigation of the Relationship of Achievement Motivation with Achievement in Mathematics for Students in the United States and Japan.

ERIC Educational Resources Information Center

Harnisch, Delwyn L.; Ryan, Katherine E.

A study was made of cross-cultural patterns of achievement motivation in relationship to the mathematics achievement of Japanese and American boys and girls approximately 16 years of age. Sample sizes were 9,582 for the United States subjects (specifically, from Illinois) and 1,700 for the participants from Japan. Data came from performance on the…

Kindergarten Children's Perception of Animals Focusing on the Look and Fear of Animals

ERIC Educational Resources Information Center

Kubiatko, Milan

2012-01-01

The study is focusing on the finding out the children's perceiving of animals from the view of look and fear. The additional aims were to find out the influence of gender and age on the perceiving of animals from the view of look and fear. The sample size was created by the 27 Czech kindergarten children from two kindergartens. The number of 5…

Chesapeake Bay impact structure: A blast from the past

USGS Publications Warehouse

Powars, David S.; Edwards, Lucy E.; Gohn, Gregory S.; Horton, J. Wright

2015-10-28

Since its discovery in the early 1990s, scientists have conducted deep drilling and geophysical surveys of the impact structure to find out more about its size, composition, structure, age, and biological effects and to understand its lingering influences on the regional groundwater system. These efforts culminated in the drilling of a 1-mile-deep, continuously sampled corehole in 2005 by an international group of scientists and agencies.

K-Ar dating and delta O-18-delta D characterization of nanometric illite from Ordovician K-bentonites of the Appalachians: illitization and the Acadian-Alleghenian tectonic activity

USGS Publications Warehouse

Clauer, Norbert; Fallick, Anthony E.; Eberl, Dennis D.; Honty, Miroslav; Huff, Warren D.; Auberti, Amelie

2013-01-01

Nanometric (2 diagram that illitization occurred in all fractions by simultaneous nucleation and crystal growth, except for one sample. In that sample, a period of growth without nucleation was detected on top of the nucleation and growth episode. The K-Ar ages organize into two isochrons, the first at 319.9 ± 2.0 Ma with an initial 40Ar/36Ar ratio of 271 ± 66 Ma, and the second at 284.9 ± 1.2 Ma with an initial 40Ar/36Ar ratio of 310 ± 44. One data point above the older isochron and three between the two isochrons suggest a detrital contamination for the former separate and a possible further generation of nanoparticles for the three others. The samples with the older crystallization age consist of illite and illite-rich mixed-layers, and those with the younger age contain smectite-rich mixed-layers without illite, or illite-enriched illite-smectite mixed-layers. The K-Ar ages fit the age trends published previously for similar K-bentonites with regional age patterns between 240 and 270 Ma in the southwestern region, between 270 and 300 Ma in the central zone and the southern Appalachians, and between 315 and 370 Ma in the northernmost. Each of the two generations of illite crystals yields very consistent δ18O (V-SMOW) values at 17 ± 1‰ for the older and at 21 ± 1‰ for the younger. If crystallization temperatures of the nanometric illite were between 100 and 200 °C, as suggested by microthermometric determinations, the hydrothermal fluids had δ18O values of 4 ± 1‰ in the Dalton district and of 8 ± 1‰ in the Lafayette, Trenton, and Dirtseller districts at 100 °C, and of 11 ± 1 and 15 ± 1‰ in the same locations at 200 °C, probably because the water-rock isotope exchanges at elevated temperature occurred in rock-dominated systems. The δ18O of the fluids remained unchanged during local crystal growth, but varied depending on the geographic location of the samples and timing of illitization. The δD (V-SMOW) values of the different size fractions do not provide consistent information; they range from −70 to −45‰ for most nanometric and micrometric fractions (V-SMOW), but with no apparent coherent pattern. Nanometric illite-rich crystals from K-bentonite that underwent tectono-thermal alteration yield constant ages, constant clay mineralogy, constant crystallite size distributions for all of the nucleating and growing illite-type crystals of each sample, as well as constant δ18O values implying constant fluid chemistry, all pointing to geologically sudden crystallization.

Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values

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

Ubeda, Carlos, E-mail: cubeda@uta.cl; Miranda, Patricia; Vano, Eliseo

Purpose: To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Methods: Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-areamore » product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Results: Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for <1 yr; 213 for 1 to <5 yr; 82 for 5 to <10 yr; and 102 for 10 to <16 yr. The third quartile values obtained for DAP by diagnostic and therapeutic procedures and age range were 1.17 and 1.11 Gy cm{sup 2} for <1 yr; 1.74 and 1.90 Gy cm{sup 2} for 1 to <5 yr; 2.83 and 3.22 Gy cm{sup 2} for 5 to <10 yr; and 7.34 and 8.68 Gy cm{sup 2} for 10 to <16 yr, respectively. The third quartile value obtained for the DAP/body weight ratio for the full sample of procedures was 0.17 (Gy cm{sup 2}/kg) for diagnostic and therapeutic procedures. Conclusions: The data presented in this paper are an initial attempt at establishing local DRLs in pediatric interventional cardiology, from a large sample of procedures for the standard age bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there may be large differences in child size. These DRLs were obtained at the largest pediatric hospital in Chile, with an active optimization program, and could be used by other hospitals in the Latin America region to compare their current patient dose values and determine whether corrective action is appropriate.« less

Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values.

PubMed

Ubeda, Carlos; Miranda, Patricia; Vano, Eliseo

2015-02-01

To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-area product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for <1 yr; 213 for 1 to <5 yr; 82 for 5 to <10 yr; and 102 for 10 to <16 yr. The third quartile values obtained for DAP by diagnostic and therapeutic procedures and age range were 1.17 and 1.11 Gy cm 2 for <1 yr; 1.74 and 1.90 Gy cm 2 for 1 to <5 yr; 2.83 and 3.22 Gy cm 2 for 5 to <10 yr; and 7.34 and 8.68 Gy cm 2 for 10 to <16 yr, respectively. The third quartile value obtained for the DAP/body weight ratio for the full sample of procedures was 0.17 (Gy cm 2 /kg) for diagnostic and therapeutic procedures. The data presented in this paper are an initial attempt at establishing local DRLs in pediatric interventional cardiology, from a large sample of procedures for the standard age bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there may be large differences in child size. These DRLs were obtained at the largest pediatric hospital in Chile, with an active optimization program, and could be used by other hospitals in the Latin America region to compare their current patient dose values and determine whether corrective action is appropriate. © 2015 American Association of Physicists in Medicine.

Prevalence of diseases and statistical power of the Japan Nurses' Health Study.

PubMed

Fujita, Toshiharu; Hayashi, Kunihiko; Katanoda, Kota; Matsumura, Yasuhiro; Lee, Jung Su; Takagi, Hirofumi; Suzuki, Shosuke; Mizunuma, Hideki; Aso, Takeshi

2007-10-01

The Japan Nurses' Health Study (JNHS) is a long-term, large-scale cohort study investigating the effects of various lifestyle factors and healthcare habits on the health of Japanese women. Based on currently limited statistical data regarding the incidence of disease among Japanese women, our initial sample size was tentatively set at 50,000 during the design phase. The actual number of women who agreed to participate in follow-up surveys was approximately 18,000. Taking into account the actual sample size and new information on disease frequency obtained during the baseline component, we established the prevalence of past diagnoses of target diseases, predicted their incidence, and calculated the statistical power for JNHS follow-up surveys. For all diseases except ovarian cancer, the prevalence of a past diagnosis increased markedly with age, and incidence rates could be predicted based on the degree of increase in prevalence between two adjacent 5-yr age groups. The predicted incidence rate for uterine myoma, hypercholesterolemia, and hypertension was > or =3.0 (per 1,000 women, per year), while the rate of thyroid disease, hepatitis, gallstone disease, and benign breast tumor was predicted to be > or =1.0. For these diseases, the statistical power to detect risk factors with a relative risk of 1.5 or more within ten years, was 70% or higher.

The endothelial sample size analysis in corneal specular microscopy clinical examinations.

PubMed

Abib, Fernando C; Holzchuh, Ricardo; Schaefer, Artur; Schaefer, Tania; Godois, Ronialci

2012-05-01

To evaluate endothelial cell sample size and statistical error in corneal specular microscopy (CSM) examinations. One hundred twenty examinations were conducted with 4 types of corneal specular microscopes: 30 with each BioOptics, CSO, Konan, and Topcon corneal specular microscopes. All endothelial image data were analyzed by respective instrument software and also by the Cells Analyzer software with a method developed in our lab. A reliability degree (RD) of 95% and a relative error (RE) of 0.05 were used as cut-off values to analyze images of the counted endothelial cells called samples. The sample size mean was the number of cells evaluated on the images obtained with each device. Only examinations with RE < 0.05 were considered statistically correct and suitable for comparisons with future examinations. The Cells Analyzer software was used to calculate the RE and customized sample size for all examinations. Bio-Optics: sample size, 97 ± 22 cells; RE, 6.52 ± 0.86; only 10% of the examinations had sufficient endothelial cell quantity (RE < 0.05); customized sample size, 162 ± 34 cells. CSO: sample size, 110 ± 20 cells; RE, 5.98 ± 0.98; only 16.6% of the examinations had sufficient endothelial cell quantity (RE < 0.05); customized sample size, 157 ± 45 cells. Konan: sample size, 80 ± 27 cells; RE, 10.6 ± 3.67; none of the examinations had sufficient endothelial cell quantity (RE > 0.05); customized sample size, 336 ± 131 cells. Topcon: sample size, 87 ± 17 cells; RE, 10.1 ± 2.52; none of the examinations had sufficient endothelial cell quantity (RE > 0.05); customized sample size, 382 ± 159 cells. A very high number of CSM examinations had sample errors based on Cells Analyzer software. The endothelial sample size (examinations) needs to include more cells to be reliable and reproducible. The Cells Analyzer tutorial routine will be useful for CSM examination reliability and reproducibility.

Humeral development from neonatal period to skeletal maturity--application in age and sex assessment.

PubMed

Rissech, Carme; López-Costas, Olalla; Turbón, Daniel

2013-01-01

The goal of the present study is to examine cross-sectional information on the growth of the humerus based on the analysis of four measurements, namely, diaphyseal length, transversal diameter of the proximal (metaphyseal) end of the shaft, epicondylar breadth and vertical diameter of the head. This analysis was performed in 181 individuals (90 ♂ and 91 ♀) ranging from birth to 25 years of age and belonging to three documented Western European skeletal collections (Coimbra, Lisbon and St. Bride). After testing the homogeneity of the sample, the existence of sexual differences (Student's t- and Mann-Whitney U-test) and the growth of the variables (polynomial regression) were evaluated. The results showed the presence of sexual differences in epicondylar breadth above 20 years of age and vertical diameter of the head from 15 years of age, thus indicating that these two variables may be of use in determining sex from that age onward. The growth pattern of the variables showed a continuous increase and followed first- and second-degree polynomials. However, growth of the transversal diameter of the proximal end of the shaft followed a fourth-degree polynomial. Strong correlation coefficients were identified between humeral size and age for each of the four metric variables. These results indicate that any of the humeral measurements studied herein is likely to serve as a useful means of estimating sub-adult age in forensic samples.

Meal size is a critical driver of weight gain in early childhood.

PubMed

Syrad, Hayley; Llewellyn, Clare H; Johnson, Laura; Boniface, David; Jebb, Susan A; van Jaarsveld, Cornelia H M; Wardle, Jane

2016-06-20

Larger serving sizes and more frequent eating episodes have been implicated in the rising prevalence of obesity at a population level. This study examines the relative contributions of meal size and frequency to weight gain in a large sample of British children. Using 3-day diet diaries from 1939 children aged 21 months from the Gemini twin cohort, we assessed prospective associations between meal size, meal frequency and weight gain from two to five years. Separate longitudinal analyses demonstrated that every 10 kcal increase in meal size was associated with 1.5 g/wk or 4% (p = 0.005) faster growth rate, while meal frequency was not independently associated with growth (β = 0.3 g/wk p = 0.20). Including both meal parameters in the model strengthened associations (meal size: β = 2.6 g/wk, p < 0.001; meal frequency: β = 1.0 g/wk, p = 0.001). Taken together, the implication is that meal size promotes faster growth regardless of frequency, but meal frequency has a significant effect only if meal size is assumed to be held constant. Clearer advice on meal size and frequency, especially advice on appropriate meal size, may help prevent excess weight gain.

Accounting for twin births in sample size calculations for randomised trials.

PubMed

Yelland, Lisa N; Sullivan, Thomas R; Collins, Carmel T; Price, David J; McPhee, Andrew J; Lee, Katherine J

2018-05-04

Including twins in randomised trials leads to non-independence or clustering in the data. Clustering has important implications for sample size calculations, yet few trials take this into account. Estimates of the intracluster correlation coefficient (ICC), or the correlation between outcomes of twins, are needed to assist with sample size planning. Our aims were to provide ICC estimates for infant outcomes, describe the information that must be specified in order to account for clustering due to twins in sample size calculations, and develop a simple tool for performing sample size calculations for trials including twins. ICCs were estimated for infant outcomes collected in four randomised trials that included twins. The information required to account for clustering due to twins in sample size calculations is described. A tool that calculates the sample size based on this information was developed in Microsoft Excel and in R as a Shiny web app. ICC estimates ranged between -0.12, indicating a weak negative relationship, and 0.98, indicating a strong positive relationship between outcomes of twins. Example calculations illustrate how the ICC estimates and sample size calculator can be used to determine the target sample size for trials including twins. Clustering among outcomes measured on twins should be taken into account in sample size calculations to obtain the desired power. Our ICC estimates and sample size calculator will be useful for designing future trials that include twins. Publication of additional ICCs is needed to further assist with sample size planning for future trials. © 2018 John Wiley & Sons Ltd.

Sex-Related Differences in the Developmental Morphology of the Atlas: A Computed Tomography Study.

PubMed

Asukai, Mitsuru; Fujita, Tomotada; Suzuki, Daisuke; Nishida, Tatsuya; Ohishi, Tsuyoshi; Matsuyama, Yukihiro

2018-05-15

A retrospective study. To elucidate sex-related differences in the age at synchondroses closure, the normative size of the atlas, and the ossification patterns of the atlas in Japanese children. The atlas develops from three ossification centers during childhood. The anterior and posterior synchondroses, which are separate ossification centers, mimic fracture lines on computed tomography (CT). Sex-related differences of age dependent morphological changes of the atlas in a large sample size have not been reported. This study analyzed data of 688 subjects (449 boys) between 0 and 18 years old who underwent CT examination of the head and/or neck between January 2010 and July 2016. The age at synchondroses closure, anteroposterior outer, inner, and spinal canal widths of the atlas, and variations of the ossification centers were examined. Anterior synchondroses closed by 10 years in boys and by 7 years in girls. Significant earlier closure of anterior synchondroses was observed in girls than in boys (P < 0.05 at 4 and 5 years old). Posterior synchondrosis closed by 6 years in boys and by 5 years in girls. The outer, inner, and spinal canal widths increased up to 10 to 15 years in both sexes, although all three parameters in girls peaked 3 years earlier than those in boys. All parameters in boys were significantly larger than those in girls, except in the 10- to 12-year-old age category. Two or more ossification centers in the anterior arch were observed in 18.3% subjects, and 6% had midline ossification centers in the posterior arch of the atlas. Distinct sex-related differences in the age at anterior synchondroses closure and the size of the atlas were observed in Japanese children. Knowledge of morphological features of the atlas could help distinguish fractures from synchondroses. 3.

Ontogenetic development of otoliths in Alligator Gar

USGS Publications Warehouse

Long, James M.; Snow, Richard A.

2016-01-01

The Alligator Gar Atractosteus spatula is a species of conservation concern throughout its range, and better definition of otoliths during early development would aid understanding its life history and ecology. We conducted X-ray computed tomography scans, scanning electron microscopy, and light microscopy to examine the three pairs of otoliths and how they developed over time in relation to fish size and age. The sagittae are the largest, possessing distinct dorsal and ventral lobes covered with small otoconia concentrated in the sulcul region. The sagittae exhibited allometric growth, increasing more rapidly in the ventral lobe than in the dorsal. The asterisci were smaller and also exhibited small otoconia on their surface, but much less than the sagittae. The lapilli were oriented laterally, in contrast to the sagittae and asterisci, which were oriented vertically, with a hump on the dorsum and very large otoconia on the lateral surface that appeared to fuse into the main otolith as the fish grew. Based on size measurements and ring counts in all three pairs of otoliths from 101 known-age Alligator Gar sampled weekly through 91 d after hatch, we developed regression models to examine otolith growth and predict age. All relationships were significant and highly explanatory, but the strongest relationships were between otolith and fish size (for measurements from sagittae) and for age predictions from the lapillus. Age prediction models all resulted in a slope near unity, indicating that ring deposition occurred approximately daily. The first ring in sagittae and lapilli corresponded to swim-up, whereas the first ring formed in asterisci approximately 8 d after swim-up. These results fill a gap in knowledge and can aid understanding of evolutionary processes as well as provide useful information for management and conservation.

Development of modern human subadult age and sex estimation standards using multi-slice computed tomography images from medical examiner's offices

NASA Astrophysics Data System (ADS)

Stock, Michala K.; Stull, Kyra E.; Garvin, Heather M.; Klales, Alexandra R.

2016-10-01

Forensic anthropologists are routinely asked to estimate a biological profile (i.e., age, sex, ancestry and stature) from a set of unidentified remains. In contrast to the abundance of collections and techniques associated with adult skeletons, there is a paucity of modern, documented subadult skeletal material, which limits the creation and validation of appropriate forensic standards. Many are forced to use antiquated methods derived from small sample sizes, which given documented secular changes in the growth and development of children, are not appropriate for application in the medico-legal setting. Therefore, the aim of this project is to use multi-slice computed tomography (MSCT) data from a large, diverse sample of modern subadults to develop new methods to estimate subadult age and sex for practical forensic applications. The research sample will consist of over 1,500 full-body MSCT scans of modern subadult individuals (aged birth to 20 years) obtained from two U.S. medical examiner's offices. Statistical analysis of epiphyseal union scores, long bone osteometrics, and os coxae landmark data will be used to develop modern subadult age and sex estimation standards. This project will result in a database of information gathered from the MSCT scans, as well as the creation of modern, statistically rigorous standards for skeletal age and sex estimation in subadults. Furthermore, the research and methods developed in this project will be applicable to dry bone specimens, MSCT scans, and radiographic images, thus providing both tools and continued access to data for forensic practitioners in a variety of settings.

Sample size determination for mediation analysis of longitudinal data.

PubMed

Pan, Haitao; Liu, Suyu; Miao, Danmin; Yuan, Ying

2018-03-27

Sample size planning for longitudinal data is crucial when designing mediation studies because sufficient statistical power is not only required in grant applications and peer-reviewed publications, but is essential to reliable research results. However, sample size determination is not straightforward for mediation analysis of longitudinal design. To facilitate planning the sample size for longitudinal mediation studies with a multilevel mediation model, this article provides the sample size required to achieve 80% power by simulations under various sizes of the mediation effect, within-subject correlations and numbers of repeated measures. The sample size calculation is based on three commonly used mediation tests: Sobel's method, distribution of product method and the bootstrap method. Among the three methods of testing the mediation effects, Sobel's method required the largest sample size to achieve 80% power. Bootstrapping and the distribution of the product method performed similarly and were more powerful than Sobel's method, as reflected by the relatively smaller sample sizes. For all three methods, the sample size required to achieve 80% power depended on the value of the ICC (i.e., within-subject correlation). A larger value of ICC typically required a larger sample size to achieve 80% power. Simulation results also illustrated the advantage of the longitudinal study design. The sample size tables for most encountered scenarios in practice have also been published for convenient use. Extensive simulations study showed that the distribution of the product method and bootstrapping method have superior performance to the Sobel's method, but the product method was recommended to use in practice in terms of less computation time load compared to the bootstrapping method. A R package has been developed for the product method of sample size determination in mediation longitudinal study design.

Cratering efficiency on coarse-grain targets: Implications for the dynamical evolution of asteroid 25143 Itokawa

NASA Astrophysics Data System (ADS)

Tatsumi, Eri; Sugita, Seiji

2018-01-01

Remote sensing observations made by the spacecraft Hayabusa provided the first direct evidence of a rubble-pile asteroid: 25143 Itokawa. Itokawa was found to have a surface structure very different from other explored asteroids; covered with coarse pebbles and boulders ranging at least from cm to meter size. The cumulative size distribution of small circular depressions on Itokawa, most of which may be of impact origin, has a significantly shallower slope than that on the Moon; small craters are highly depleted on Itokawa compared to the Moon. This deficiency of small circular depressions and other features, such as clustered fragments and pits on boulders, suggest that the boulders on Itokawa might behave like armor, preventing crater formation: the ;armoring effect;. This might contribute to the low number density of small crater candidates. In this study, the cratering efficiency reduction due to coarse-grained targets was investigated based on impact experiments at velocities ranging from ∼ 70 m/s to ∼ 6 km/s using two vertical gas gun ranges. We propose a scaling law extended for cratering on coarse-grained targets (i.e., target grain size ≳ projectile size). We have found that the crater efficiency reduction is caused by energy dissipation at the collision site where momentum is transferred from the impactor to the first-contact target grain, and that the armoring effect can be classified into three regimes: (1) gravity scaled regime, (2) reduced size crater regime, or (3) no apparent crater regime, depending on the ratio of the impactor size to the target grain size and the ratio of the impactor kinetic energy to the disruption energy of a target grain. We found that the shallow slope of the circular depressions on Itokawa cannot be accounted for by this new scaling law, suggesting that obliteration processes, such as regolith convection and migration, play a greater role in the depletion of circular depressions on Itokawa. Based on the new extended scaling law, we found that the crater retention age on Itokawa is 3-33 Myr in the main belt, which is in good agreement with the cosmic-ray-exposure ages for returned samples from Itokawa which may reflect the age of material a few meters beneath the surface. These ages strongly suggest that the global resurfacing that reset the 1-10 m deep surface layer may have occurred in the main belt long after the possible catastrophic disruption of a rigid parent body of Itokawa suggested by Ar degassing age ( ∼ 1.3 Gyr).

Assessment of resource selection models to predict occurrence of five juvenile flatfish species (Pleuronectidae) over the continental shelf in the western Gulf of Alaska

NASA Astrophysics Data System (ADS)

Wilson, Matthew T.; Mier, Kathryn L.; Cooper, Dan W.

2016-05-01

According to the nursery size hypothesis, flatfish recruitment is constrained by nursery area. Thus, if resource selection models can be shown to accurately predict the location and geographic extent of flatfish nursery areas, they will become important tools in the management and study of flatfish population dynamics. We demonstrate that some resource selection models derived previously to predict the presence and absence of juvenile flatfishes near shore were applicable to the broader continental shelf. For other age-species groups, derivation of new models for the continental shelf was necessary. Our study was conducted in the western Gulf of Alaska (GoA) during October 2011 on four groups of age-0 juvenile flatfishes: Pacific halibut (Hippoglossus stenolepis), arrowtooth flounder (Atheresthes stomias), northern rock sole (Lepidopsetta polyxystra), and flathead sole (Hippoglossoides elassodon); and three groups of age-1 juvenile flatfishes: northern rock sole, flathead sole, and yellowfin sole (Limanda aspera). Sampling occurred at 33 sites across the continental shelf. Fish were collected using a 3-m beam trawl, and a midwater trawl. Environmental data were collected on sediment composition and water temperature and depth. Many of the age-species groups co-occurred in the Shumagin and Barnabus sea valleys; however, age-0 arrowtooth flounder occurred at more locations than other juveniles, perhaps due to a relatively broad tolerance of environmental conditions and to the utilization of midwater habitat. Thus, the large nursery area of arrowtooth flounder may be one reason why they are currently the most abundant GoA flatfish. In fact, among all species, mean recruitment at age 3 increased with the percent occurrence of age-0 juveniles at the 33 sites, a proxy for relative nursery area, in accordance with the nursery size hypothesis, suggesting that mean recruitment among GoA flatfishes is structured by nursery size.

Red blood cells open promising avenues for longitudinal studies of ageing in laboratory, non-model and wild animals.

PubMed

Stier, Antoine; Reichert, Sophie; Criscuolo, Francois; Bize, Pierre

2015-11-01

Ageing is characterized by a progressive deterioration of multiple physiological and molecular pathways, which impair organismal performance and increase risks of death with advancing age. Hence, ageing studies must identify physiological and molecular pathways that show signs of age-related deterioration, and test their association with the risk of death and longevity. This approach necessitates longitudinal sampling of the same individuals, and therefore requires a minimally invasive sampling technique that provides access to the larger spectrum of physiological and molecular pathways that are putatively associated with ageing. The present paper underlines the interest in using red blood cells (RBCs) as a promising target for longitudinal studies of ageing in vertebrates. RBCs provide valuable information on the following six pathways: cell maintenance and turnover (RBC number, size, and heterogeneity), glucose homeostasis (RBC glycated haemoglobin), oxidative stress parameters, membrane composition and integrity, mitochondrial functioning, and telomere dynamics. The last two pathways are specific to RBCs of non-mammalian species, which possess a nucleus and functional mitochondria. We present the current knowledge about RBCs and age-dependent changes in these pathways in non-model and wild species that are especially suitable to address questions related to ageing using longitudinal studies. We discuss how the different pathways relate with survival and lifespan and give information on their genetic and environmental determinants to appraise their evolutionary potential. Copyright © 2015 Elsevier Inc. All rights reserved.

Public Opinion Polls, Chicken Soup and Sample Size

ERIC Educational Resources Information Center

Nguyen, Phung

2005-01-01

Cooking and tasting chicken soup in three different pots of very different size serves to demonstrate that it is the absolute sample size that matters the most in determining the accuracy of the findings of the poll, not the relative sample size, i.e. the size of the sample in relation to its population.

Sample size in studies on diagnostic accuracy in ophthalmology: a literature survey.

PubMed

Bochmann, Frank; Johnson, Zoe; Azuara-Blanco, Augusto

2007-07-01

To assess the sample sizes used in studies on diagnostic accuracy in ophthalmology. Design and sources: A survey literature published in 2005. The frequency of reporting calculations of sample sizes and the samples' sizes were extracted from the published literature. A manual search of five leading clinical journals in ophthalmology with the highest impact (Investigative Ophthalmology and Visual Science, Ophthalmology, Archives of Ophthalmology, American Journal of Ophthalmology and British Journal of Ophthalmology) was conducted by two independent investigators. A total of 1698 articles were identified, of which 40 studies were on diagnostic accuracy. One study reported that sample size was calculated before initiating the study. Another study reported consideration of sample size without calculation. The mean (SD) sample size of all diagnostic studies was 172.6 (218.9). The median prevalence of the target condition was 50.5%. Only a few studies consider sample size in their methods. Inadequate sample sizes in diagnostic accuracy studies may result in misleading estimates of test accuracy. An improvement over the current standards on the design and reporting of diagnostic studies is warranted.

Caution regarding the choice of standard deviations to guide sample size calculations in clinical trials.

PubMed

Chen, Henian; Zhang, Nanhua; Lu, Xiaosun; Chen, Sophie

2013-08-01

The method used to determine choice of standard deviation (SD) is inadequately reported in clinical trials. Underestimations of the population SD may result in underpowered clinical trials. This study demonstrates how using the wrong method to determine population SD can lead to inaccurate sample sizes and underpowered studies, and offers recommendations to maximize the likelihood of achieving adequate statistical power. We review the practice of reporting sample size and its effect on the power of trials published in major journals. Simulated clinical trials were used to compare the effects of different methods of determining SD on power and sample size calculations. Prior to 1996, sample size calculations were reported in just 1%-42% of clinical trials. This proportion increased from 38% to 54% after the initial Consolidated Standards of Reporting Trials (CONSORT) was published in 1996, and from 64% to 95% after the revised CONSORT was published in 2001. Nevertheless, underpowered clinical trials are still common. Our simulated data showed that all minimal and 25th-percentile SDs fell below 44 (the population SD), regardless of sample size (from 5 to 50). For sample sizes 5 and 50, the minimum sample SDs underestimated the population SD by 90.7% and 29.3%, respectively. If only one sample was available, there was less than 50% chance that the actual power equaled or exceeded the planned power of 80% for detecting a median effect size (Cohen's d = 0.5) when using the sample SD to calculate the sample size. The proportions of studies with actual power of at least 80% were about 95%, 90%, 85%, and 80% when we used the larger SD, 80% upper confidence limit (UCL) of SD, 70% UCL of SD, and 60% UCL of SD to calculate the sample size, respectively. When more than one sample was available, the weighted average SD resulted in about 50% of trials being underpowered; the proportion of trials with power of 80% increased from 90% to 100% when the 75th percentile and the maximum SD from 10 samples were used. Greater sample size is needed to achieve a higher proportion of studies having actual power of 80%. This study only addressed sample size calculation for continuous outcome variables. We recommend using the 60% UCL of SD, maximum SD, 80th-percentile SD, and 75th-percentile SD to calculate sample size when 1 or 2 samples, 3 samples, 4-5 samples, and more than 5 samples of data are available, respectively. Using the sample SD or average SD to calculate sample size should be avoided.

Simulated fissioning of uranium and testing of the fission-track dating method

USGS Publications Warehouse

McGee, V.E.; Johnson, N.M.; Naeser, C.W.

1985-01-01

A computer program (FTD-SIM) faithfully simulates the fissioning of 238U with time and 235U with neutron dose. The simulation is based on first principles of physics where the fissioning of 238U with the flux of time is described by Ns = ??f 238Ut and the fissioning of 235U with the fluence of neutrons is described by Ni = ??235U??. The Poisson law is used to set the stochastic variation of fissioning within the uranium population. The life history of a given crystal can thus be traced under an infinite variety of age and irradiation conditions. A single dating attempt or up to 500 dating attempts on a given crystal population can be simulated by specifying the age of the crystal population, the size and variation in the areas to be counted, the amount and distribution of uranium, the neutron dose to be used and its variation, and the desired ratio of 238U to 235U. A variety of probability distributions can be applied to uranium and counting-area. The Price and Walker age equation is used to estimate age. The output of FTD-SIM includes the tabulated results of each individual dating attempt (sample) on demand and/or the summary statistics and histograms for multiple dating attempts (samples) including the sampling age. An analysis of the results from FTD-SIM shows that: (1) The external detector method is intrinsically more precise than the population method. (2) For the external detector method a correlation between spontaneous track count, Ns, and induced track count, Ni, results when the population of grains has a stochastic uranium content and/or when the counting areas between grains are stochastic. For the population method no correlation can exist. (3) In the external detector method the sampling distribution of age is independent of the number of grains counted. In the population method the sampling distribution of age is highly dependent on the number of grains counted. (4) Grains with zero-track counts, either in Ns or Ni, are in integral part of fissioning theory and under certain circumstances must be included in any estimate of age. (5) In estimating standard error of age the standard error of Ns and Ni and ?? must be accurately estimated and propagated through the age equation. Several statistical models are presently available to do so. ?? 1985.

Lower levels of human milk adiponectin predict offspring weight for age: a study in a lean population of Filipinos.

PubMed

Anderson, Justine; McKinley, Kassielle; Onugha, Jason; Duazo, Paulita; Chernoff, Meytal; Quinn, Elizabeth A

2016-10-01

Prior studies have reported a significant, inverse association between adiponectin in human milk and offspring growth velocity. Less is known about this association in populations characterised by a loss of weight for age z-scores (WAZs) in early life. We investigated the association between maternal body composition and milk adiponectin in a sample of Filipino mothers. We then tested for an association between milk adiponectin and size for age in their infants. A total of 117 Filipino mothers nursing infants from 0 to 24 months were recruited from Cebu, Philippines. Anthropometrics, interviews and milk samples were collected and analysed using standard protocols. Mean milk adiponectin in this sample was 7.47 ± 5.75 ng mL(-1) . Mean infant WAZ and weight for length (WLZ) decreased with age. Maternal body composition was not associated with milk adiponectin content. Milk adiponectin had a significant, positive association with infant WAZ and WLZ. Prior reports have found an inverse association between milk adiponectin and infant WAZ. Here, we report that in lean populations with lower milk adiponectin, there is a positive association with infant WAZ, possibly reflecting pleiotropic biological functions of adiponectin for post-natal growth. This study increases the understanding of normal biological variation in milk adiponectin and the consequences of low levels of milk adiponectin for offspring growth. © 2015 John Wiley & Sons Ltd.

Household Food Insecurity, Underweight Status, and Associated Characteristics among Women of Reproductive Age Group in Assayita District, Afar Regional State, Ethiopia.

PubMed

Abdu, Jemal; Kahssay, Molla; Gebremedhin, Merhawi

2018-01-01

Poor nutritional status of women has been a serious problem in Ethiopia. Rural women are more likely to be undernourished than urban women. Afar region is the most likely to be undernourished (43.5%). Despite the humanitarian and food aid, food insecurity and maternal underweight are very high in the region. Household food insecurity is not adequately studied in Afar region. The aim of this study was to assess the prevalence of household food insecurity and underweight status and its association among reproductive age women. The study was conducted in Assayita district in June 2015. Community-based cross-sectional study design was used among nonpregnant women. Household data was collected using structured questionnaire. Multistage cluster sampling procedure was applied. Two pastoral and two agropastoral Kebeles have been selected by simple random sampling. Systematic random sampling was used to select respondents. The total sample size was 549 households. Household Food Insecurity Access Scale (HFIAS) and anthropometric data were used to determine food insecurity and underweight, respectively. Multivariate regression models were used to measure associations. Prevalence of HFIAS was 70.4 with a mean of 7.0 (3.6 ± SD); 26.1%, 30.20%, and 14.1% were mild, moderate, and severe food insecurity, respectively. Underweight prevalence (BMI < 18.5) was 41.1% with prevalence of mild, moderate, and severe underweight being 34.5%, 3.9%, and 2.7%, respectively. Age, parity, and having >2 children below five years of age were statistically associated with household food insecurity and maternal underweight. Household food insecurity and maternal underweight were very high. Age, parity, and having ≥2 children below five years of age were associated with household food insecurity. Maternal underweight was associated with maternal age, marital status, parity, number of children below 5 years, household food insecurity, and vocation of the respondents.