Demographic analysis from summaries of an age-structured population
Link, William A.; Royle, J. Andrew; Hatfield, Jeff S.
2003-01-01
Demographic analyses of age-structured populations typically rely on life history data for individuals, or when individual animals are not identified, on information about the numbers of individuals in each age class through time. While it is usually difficult to determine the age class of a randomly encountered individual, it is often the case that the individual can be readily and reliably assigned to one of a set of age classes. For example, it is often possible to distinguish first-year from older birds. In such cases, the population age structure can be regarded as a latent variable governed by a process prior, and the data as summaries of this latent structure. In this article, we consider the problem of uncovering the latent structure and estimating process parameters from summaries of age class information. We present a demographic analysis for the critically endangered migratory population of whooping cranes (Grus americana), based only on counts of first-year birds and of older birds. We estimate age and year-specific survival rates. We address the controversial issue of whether management action on the breeding grounds has influenced recruitment, relating recruitment rates to the number of seventh-year and older birds, and examining the pattern of variation through time in this rate.
Global stability of an age-structure epidemic model with imperfect vaccination and relapse
NASA Astrophysics Data System (ADS)
Cao, Bin; Huo, Hai-Feng; Xiang, Hong
2017-11-01
A new age-structured epidemic model with imperfect vaccination and relapse is proposed. The total population of our model is partitioned into five subclasses: susceptible class S, vaccinated class V, exposed class E, infectious class I and removed class R. Age-structures are equipped with in exposed and recovered classes. Furthermore, imperfect vaccination is also introduced in our model. The basic reproduction number R0 is defined and proved as a threshold parameter of the model. Asymptotic smoothness of solutions and uniform persistence of the system are showed via reformulating the system as a system of Volterra integral equation. Furthermore, by constructing proper Volterra-type Lyapunov functional we get when R0 < 1, the disease-free equilibrium is globally asymptotically stable. When R0 > 1, the endemic equilibrium is globally stable. Our results show that to increase the efficiency of vaccination and reduce influence of relapse are vital essential for controlling epidemic.
ERIC Educational Resources Information Center
Lopez Castillo, Maria A.; Carlson, Jordan A.; Cain, Kelli L.; Bonilla, Edith A.; Chuang, Emmeline; Elder, John P.; Sallis, James F.
2015-01-01
Purpose: The study aims were to determine: (a) how class structure varies by dance type, (b) how moderate-to-vigorous physical activity (MVPA) and sedentary behavior vary by dance class segments, and (c) how class structure relates to total MVPA in dance classes. Method: Participants were 291 boys and girls ages 5 to 18 years old enrolled in 58…
Uncertainty in age-specific harvest estimates and consequences for white-tailed deer management
Collier, B.A.; Krementz, D.G.
2007-01-01
Age structure proportions (proportion of harvested individuals within each age class) are commonly used as support for regulatory restrictions and input for deer population models. Such use requires critical evaluation when harvest regulations force hunters to selectively harvest specific age classes, due to impact on the underlying population age structure. We used a stochastic population simulation model to evaluate the impact of using harvest proportions to evaluate changes in population age structure under a selective harvest management program at two scales. Using harvest proportions to parameterize the age-specific harvest segment of the model for the local scale showed that predictions of post-harvest age structure did not vary dependent upon whether selective harvest criteria were in use or not. At the county scale, yearling frequency in the post-harvest population increased, but model predictions indicated that post-harvest population size of 2.5 years old males would decline below levels found before implementation of the antler restriction, reducing the number of individuals recruited into older age classes. Across the range of age-specific harvest rates modeled, our simulation predicted that underestimation of age-specific harvest rates has considerable influence on predictions of post-harvest population age structure. We found that the consequence of uncertainty in harvest rates corresponds to uncertainty in predictions of residual population structure, and this correspondence is proportional to scale. Our simulations also indicate that regardless of use of harvest proportions or harvest rates, at either the local or county scale the modeled SHC had a high probability (>0.60 and >0.75, respectively) of eliminating recruitment into >2.5 years old age classes. Although frequently used to increase population age structure, our modeling indicated that selective harvest criteria can decrease or eliminate the number of white-tailed deer recruited into older age classes. Thus, we suggest that using harvest proportions for management planning and evaluation should be viewed with caution. In addition, we recommend that managers focus more attention on estimation of age-specific harvest rates, and modeling approaches which combine harvest rates with information from harvested individuals to further increase their ability to effectively manage deer populations under selective harvest programs. ?? 2006 Elsevier B.V. All rights reserved.
Lopez Castillo, Maria A; Carlson, Jordan A; Cain, Kelli L; Bonilla, Edith A; Chuang, Emmeline; Elder, John P; Sallis, James F
2015-01-01
The study aims were to determine: (a) how class structure varies by dance type, (b) how moderate-to-vigorous physical activity (MVPA) and sedentary behavior vary by dance class segments, and (c) how class structure relates to total MVPA in dance classes. Participants were 291 boys and girls ages 5 to 18 years old enrolled in 58 dance classes at 21 dance studios in Southern California. MVPA and sedentary behavior were assessed with accelerometry, with data aggregated to 15-s epochs. Percent and minutes of MVPA and sedentary behavior during dance class segments and percent of class time and minutes spent in each segment were calculated using Freedson age-specific cut points. Differences in MVPA (Freedson 3 Metabolic Equivalents of Tasks age-specific cut points) and sedentary behavior ( < 100 counts/min) were examined using mixed-effects linear regression. The length of each class segment was fairly consistent across dance types, with the exception that in ballet, more time was spent in technique as compared with private jazz/hip-hop classes and Latin-flamenco and less time was spent in routine/practice as compared with Latin-salsa/ballet folklorico. Segment type accounted for 17% of the variance in the proportion of the segment spent in MVPA. The proportion of the segment in MVPA was higher for routine/practice (44.2%) than for technique (34.7%). The proportion of the segment in sedentary behavior was lowest for routine/practice (22.8%). The structure of dance lessons can impact youths' physical activity. Working with instructors to increase time in routine/practice during dance classes could contribute to physical activity promotion in youth.
Engen, Steinar; Lee, Aline Magdalena; Sæther, Bernt-Erik
2018-02-01
We analyze a spatial age-structured model with density regulation, age specific dispersal, stochasticity in vital rates and proportional harvesting. We include two age classes, juveniles and adults, where juveniles are subject to logistic density dependence. There are environmental stochastic effects with arbitrary spatial scales on all birth and death rates, and individuals of both age classes are subject to density independent dispersal with given rates and specified distributions of dispersal distances. We show how to simulate the joint density fields of the age classes and derive results for the spatial scales of all spatial autocovariance functions for densities. A general result is that the squared scale has an additive term equal to the squared scale of the environmental noise, corresponding to the Moran effect, as well as additive terms proportional to the dispersal rate and variance of dispersal distance for the age classes and approximately inversely proportional to the strength of density regulation. We show that the optimal harvesting strategy in the deterministic case is to harvest only juveniles when their relative value (e.g. financial) is large, and otherwise only adults. With increasing environmental stochasticity there is an interval of increasing length of values of juveniles relative to adults where both age classes should be harvested. Harvesting generally tends to increase all spatial scales of the autocovariances of densities. Copyright © 2017. Published by Elsevier Inc.
Riley, Kathryn N; Browne, Robert A
2011-01-01
We examined diversity, community composition, and wing-state of Carabidae as a function of forest age in Piedmont North Carolina. Carabidae were collected monthly from 396 pitfall traps (12×33 sites) from March 2009 through February 2010, representing 5 forest age classes approximately 0, 10, 50, 85, and 150 years old. A total of 2,568 individuals, representing 30 genera and 63 species, were collected. Carabid species diversity, as estimated by six diversity indices, was significantly different between the oldest and youngest forest age classes for four of the six indices. Most carabid species were habitat generalists, occurring in all or most of the forest age classes. Carabid species composition varied across forest age classes. Seventeen carabid species were identified as potential candidates for ecological indicators of forest age. Non-metric multidimensional scaling (NMDS) showed separation among forest age classes in terms of carabid beetle community composition. The proportion of individuals capable of flight decreased significantly with forest age.
Riley, Kathryn N.; Browne, Robert A.
2011-01-01
Abstract We examined diversity, community composition, and wing-state of Carabidae as a function of forest age in Piedmont North Carolina. Carabidae were collected monthly from 396 pitfall traps (12×33 sites) from March 2009 through February 2010, representing 5 forest age classes approximately 0, 10, 50, 85, and 150 years old. A total of 2,568 individuals, representing 30 genera and 63 species, were collected. Carabid species diversity, as estimated by six diversity indices, was significantly different between the oldest and youngest forest age classes for four of the six indices. Most carabid species were habitat generalists, occurring in all or most of the forest age classes. Carabid species composition varied across forest age classes. Seventeen carabid species were identified as potential candidates for ecological indicators of forest age. Non-metric multidimensional scaling (NMDS) showed separation among forest age classes in terms of carabid beetle community composition. The proportion of individuals capable of flight decreased significantly with forest age. PMID:22371677
Terry-McElrath, Yvonne M; O'Malley, Patrick M; Johnston, Lloyd D
2017-12-13
Effective cigarette smoking prevention and intervention programming is enhanced by accurate understanding of developmental smoking pathways across the life span. This study investigated within-person patterns of cigarette smoking from ages 18 to 50 among a US national sample of high school graduates, focusing on identifying ages of particular importance for smoking involvement change. Using data from approximately 15,000 individuals participating in the longitudinal Monitoring the Future study, trichotomous measures of past 30-day smoking obtained at 11 time points were modeled using repeated-measures latent class analyses. Sex differences in latent class structure and membership were examined. Twelve latent classes were identified: three characterized by consistent smoking patterns across age (no smoking; smoking < pack per day; smoking pack + per day); three showing uptake to a higher category of smoking across age; four reflecting successful quit behavior by age 50; and two defined by discontinuous shifts between smoking categories. The same latent class structure was found for both males and females, but membership probabilities differed between sexes. Although evidence of increases or decreases in smoking behavior was observed at virtually all ages through 35, 21/22 and 29/30 appeared to be particularly key for smoking category change within class. This examination of latent classes of cigarette smoking among a national US longitudinal sample of high school graduates from ages 18 to 50 identified unique patterns and critical ages of susceptibility to change in smoking category within class. Such information may be of particular use in developing effective smoking prevention and intervention programming. This study examined cigarette smoking among a national longitudinal US sample of high school graduates from ages 18 to 50 and identified distinct latent classes characterized by patterns of movement between no cigarette use, light-to-moderate smoking, and the conventional definition of heavy smoking at 11 time points via repeated-measures latent class analysis. Membership probabilities for each smoking class were estimated, and critical ages of susceptibility to change in smoking behaviors were identified. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
NASA Technical Reports Server (NTRS)
Sader, Steven A.; Waide, Robert B.; Lawrence, William T.; Joyce, Armond T.
1989-01-01
Forest stand structure and biomass data were collected using conventional forest inventory techniques in tropical, subtropical, and warm temperate forest biomes. The feasibility of detecting tropical forest successional age class and total biomass differences using Landsat-Thematic mapper (TM) data, was evaluated. The Normalized Difference Vegetation Index (NDVI) calculated from Landsat-TM data were not significantly correlated with forest regeneration age classes in the mountain terrain of the Luquillo Experimental Forest, Puerto Rico. The low sun angle and shadows cast on steep north and west facing slopes reduced spectral reflectance values recorded by TM orbital altitude. The NDVI, calculated from low altitude aircraft scanner data, was significatly correlated with forest age classes. However, analysis of variance suggested that NDVI differences were not detectable for successional forests older than approximately 15-20 years. Also, biomass differences in young successional tropical forest were not detectable using the NDVI. The vegetation index does not appear to be a good predictor of stand structure variables (e.g., height, diameter of main stem) or total biomass in uneven age, mixed broadleaf forest. Good correlation between the vegetation index and low biomass in even age pine plantations were achieved for a warm temperate study site. The implications of the study for the use of NDVI for forest structure and biomass estimation are discussed.
Building Structure into a Class for Emotionally Disturbed Children: One Teacher's Experience.
ERIC Educational Resources Information Center
Cambone, Joseph
The paper is a description of how one teacher structured a classroom for five seriously disturbed violent boys (ages 5.5 to 8 years) at a private residential and day school for emotionally disturbed students. Anecdotes are reported as well as the teacher's reflections. Changes in the teacher's original planned class structure while maintaining the…
Social class and workplace harassment during the transition to adulthood.
McLaughlin, Heather; Uggen, Christopher; Blackstone, Amy
2008-01-01
Young disadvantaged workers are especially vulnerable to harassment due to their age and social class position. As young people enter the workforce, their experiences of, and reactions to, harassment may vary dramatically from those of older adult workers. Three case studies introduce theory and research on the relationship between social class and harassment of young workers. We suggest two mechanisms through which class may structure harassment experiences: (1) extremely vulnerable youth are directly targeted based on their social class origins, and (2) the type and condition of youth employment, which is structured by class background, indirectly affect experiences of harassment.
J.E. Smith; R. Molina; M.M.P. Huso; D.L. Luoma; D. McKay; M.A. Castellano; T. Lebel; Y. Valachovic
2002-01-01
Knowledge of the community structure of ectomycorrhizal fungi among successional forest age-classes is critical for conserving fungal species diversity. Hypogeous and epigeous sporocarps were collected from three replicate stands in each of three forest age-classes (young, rotation-age, and old-growth) of Douglas-fir (Pseudotsuga menziesii (Mirb.)...
Samuel, Michael D.; Storm, Daniel J.; Rolley, Robert E.; Beissel, Thomas; Richards, Bryan J.; Van Deelen, Timothy R.
2014-01-01
The age structure of harvested animals provides the basis for many demographic analyses. Ages of harvested white-tailed deer (Odocoileus virginianus) and other ungulates often are estimated by evaluating replacement and wear patterns of teeth, which is subjective and error-prone. Few previous studies however, examined age- and sex-specific error rates. Counting cementum annuli of incisors is an alternative, more accurate method of estimating age, but factors that influence consistency of cementum annuli counts are poorly known. We estimated age of 1,261 adult (≥1.5 yr old) white-tailed deer harvested in Wisconsin and Illinois (USA; 2005–2008) using both wear-and-replacement and cementum annuli. We compared cementum annuli with wear-and-replacement estimates to assess misclassification rates by sex and age. Wear-and-replacement for estimating ages of white-tailed deer resulted in substantial misclassification compared with cementum annuli. Age classes of females were consistently underestimated, while those of males were underestimated for younger age classes but overestimated for older age classes. Misclassification resulted in an impression of a younger age-structure than actually was the case. Additionally, we obtained paired age-estimates from cementum annuli for 295 deer. Consistency of paired cementum annuli age-estimates decreased with age, was lower in females than males, and decreased as age estimates became less certain. Our results indicated that errors in the wear-and-replacement techniques are substantial and could impact demographic analyses that use age-structure information.
Reichert, Brian E.; Kendall, William L.; Fletcher, Robert J.; Kitchens, Wiley M.
2016-01-01
While variation in age structure over time and space has long been considered important for population dynamics and conservation, reliable estimates of such spatio-temporal variation in age structure have been elusive for wild vertebrate populations. This limitation has arisen because of problems of imperfect detection, the potential for temporary emigration impacting assessments of age structure, and limited information on age. However, identifying patterns in age structure is important for making reliable predictions of both short- and long-term dynamics of populations of conservation concern. Using a multistate superpopulation estimator, we estimated region-specific abundance and age structure (the proportion of individuals within each age class) of a highly endangered population of snail kites for two separate regions in Florida over 17 years (1997–2013). We find that in the southern region of the snail kite—a region known to be critical for the long-term persistence of the species—the population has declined significantly since 1997, and during this time, it has increasingly become dominated by older snail kites (> 12 years old). In contrast, in the northern region—a region historically thought to serve primarily as drought refugia—the population has increased significantly since 2007 and age structure is more evenly distributed among age classes. Given that snail kites show senescence at approximately 13 years of age, where individuals suffer higher mortality rates and lower breeding rates, these results reveal an alarming trend for the southern region. Our work illustrates the importance of accounting for spatial structure when assessing changes in abundance and age distribution and the need for monitoring of age structure in imperiled species.
ERIC Educational Resources Information Center
Quan-McGimpsey, Sharon; Marziliano, Sarah Carmen; Hassen, Trevor Gregory; Brown, Allison Sandra; Kuczynski, Leon
2015-01-01
This study investigated teachers' experiences of closeness during interactions with the group of children in child care. Structured interviews were conducted with 24 female teachers who were teaching children between the ages of three and five (mean age = 3.9) regarding their perceptions of closeness with the group of children in the class.…
Guffanti, Guia; Geronazzo-Alman, Lupo; Fan, Bin; Duarte, Cristiane S; Musa, George J; Hoven, Christina W
2016-10-01
Patients with a posttraumatic stress disorder (PTSD) diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM-IV; American Psychiatric Association, 1994) will very likely not share all of the same symptoms, a consequence of the polythetic approach used in the DSM. We examined heterogeneity in the latent structure of PTSD symptoms using data from a previously published sample of 8,236 youth a subset of which had been exposed to the September 11, 2001 attacks (N = 6,670; Hoven et al., 2005). Latent class analysis was applied (a) to PTSD symptoms alone, (b) to symptoms in combination with impairment indicators, and (c) to PTSD symptoms when stratified by age and gender, as well as by empirically defined classes of exposure. We identified 4 symptom classes: no disturbance (49.4%), intermediate disturbance (2 classes; 21.5% and 18.6%, respectively), and severe disturbance (10.5%). These classes varied not only in the severity of symptoms, but also in the configuration of symptoms. We observed a high probability of endorsing both PTSD symptoms and indicators of impairment only in the severe disturbance class. A similar 4-class structure was found when the data were stratified by age, gender, and exposure classes. There were no significant differences as a function of age, gender, or exposure in the presence of severe PTSD. Heterogeneity was observed at intermediate levels of PTSD symptom severity. The specific PTSD symptoms that defined the severe PTSD profile could constitute the pathogenic aspects of a largely invariant and clinically meaningful PTSD syndrome. Copyright © 2016 International Society for Traumatic Stress Studies.
Age at Immigration and Education: Further Explorations.
ERIC Educational Resources Information Center
Jones, Frank E.
1987-01-01
Presents evidence for a social structure explanation, instead of an age explanation, of variations in educational attainment among immigrants to Canada. Social status or class structure is the fundamental determinant of variation in the distribution of resources necessary to educational achievement for immigrants as well as for native-born…
Simulated cavity tree dynamics under alternative timber harvest regimes
Zhaofei Fan; Stephen R Shifley; Frank R Thompson; David R Larsen
2004-01-01
We modeled cavity tree abundance on a landscape as a function of forest stand age classes and as a function of aggregate stand size classes.We explored the impact of five timber harvest regimes on cavity tree abundance on a 3261 ha landscape in southeast Missouri, USA, by linking the stand level cavity tree distribution model to the landscape age structure simulated by...
Mannon, Susan E; Kemp, Eagan
2010-01-01
This article explores how young men in Costa Rica negotiate ideas of manhood under neoliberalism. We draw on interview data involving 23 men, ages 15–35, residing in one Costa Rican city. Comparing men across three different class locations, we find diverse "markers of manhood." Our data suggest an emerging globally dominant masculine ideal among an elite class of men, a declining locally dominant masculine ideal among working-class men, and a cynical, possibly counter-cultural masculine ideal among poor men. We conclude that masculinities are not only fluid, but tied to changing economic circumstances and class structures.
ERIC Educational Resources Information Center
Ambridge, Ben; Pine, Julian M.; Rowland, Caroline F.; Young, Chris R.
2008-01-01
Participants (aged 5-6 yrs, 9-10 yrs and adults) rated (using a five-point scale) grammatical (intransitive) and overgeneralized (transitive causative) uses of a high frequency, low frequency and novel intransitive verb from each of three semantic classes [Pinker, S. (1989a). "Learnability and cognition: the acquisition of argument structure."…
Engen, Steinar; Lande, Russell; Saether, Bernt-Erik
2011-10-01
We analyze weak fluctuating selection on a quantitative character in an age-structured population not subject to density regulation. We assume that early in the first year of life before selection, during a critical state of development, environments exert a plastic effect on the phenotype, which remains constant throughout the life of an individual. Age-specific selection on the character affects survival and fecundity, which have intermediate optima subject to temporal environmental fluctuations with directional selection in some age classes as special cases. Weighting individuals by their reproductive value, as suggested by Fisher, we show that the expected response per year in the weighted mean character has the same form as for models with no age structure. Environmental stochasticity generates stochastic fluctuations in the weighted mean character following a first-order autoregressive model with a temporally autocorrelated noise term and stationary variance depending on the amount of phenotypic plasticity. The parameters of the process are simple weighted averages of parameters used to describe age-specific survival and fecundity. The "age-specific selective weights" are related to the stable distribution of reproductive values among age classes. This allows partitioning of the change in the weighted mean character into age-specific components. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
NASA Astrophysics Data System (ADS)
Kuttner, Benjamin George
Natural fire return intervals are relatively long in eastern Canadian boreal forests and often allow for the development of stands with multiple, successive cohorts of trees. Multi-cohort forest management (MCM) provides a strategy to maintain such multi-cohort stands that focuses on three broad phases of increasingly complex, post-fire stand development, termed "cohorts", and recommends different silvicultural approaches be applied to emulate different cohort types. Previous research on structural cohort typing has relied upon primarily subjective classification methods; in this thesis, I develop more comprehensive and objective methods for three common boreal mixedwood and black spruce forest types in northeastern Ontario. Additionally, I examine relationships between cohort types and stand age, productivity, and disturbance history and the utility of airborne LiDAR to retrieve ground-based classifications and to extend structural cohort typing from plot- to stand-levels. In both mixedwood and black spruce forest types, stand age and age-related deadwood features varied systematically with cohort classes in support of an age-based interpretation of increasing cohort complexity. However, correlations of stand age with cohort classes were surprisingly weak. Differences in site productivity had a significant effect on the accrual of increasingly complex multi-cohort stand structure in both forest types, especially in black spruce stands. The effects of past harvesting in predictive models of class membership were only significant when considered in isolation of age. As an age-emulation strategy, the three cohort model appeared to be poorly suited to black spruce forests where the accrual of structural complexity appeared to be more a function of site productivity than age. Airborne LiDAR data appear to be particularly useful in recovering plot-based cohort types and extending them to the stand-level. The main gradients of structural variability detected using LiDAR were similar between boreal mixedwood and black spruce forest types; the best LiDAR-based models of cohort type relied upon combinations of tree size, size heterogeneity, and tree density related variables. The methods described here to measure, classify, and predict cohort-related structural complexity assist in translating the conceptual three cohort model to a more precise, measurement-based management system. In addition, the approaches presented here to measure and classify stand structural complexity promise to significantly enhance the detail of structural information in operational forest inventories in support of a wide array of forest management and conservation applications.
Motivating Students to Be Active outside of Class: A Hierarchy for Independent Physical Activity
ERIC Educational Resources Information Center
Hill, Grant
2009-01-01
Despite the fact that children have an extraordinary amount of leisure time, students of all ages engage in too little physical activity. Opportunities for physical activity should be provided through recesses, lunch periods, organized fitness breaks, before- and after-school activity programs, and structured physical education classes. However,…
ERIC Educational Resources Information Center
Grundmann, Matthias
This longitudinal study investigated the influence of social class and family socialization on the development of cognitive competence, educational performance, and academic attainment; the interdependencies between the development of cognitive competence and educational performance; and the impact of social class, family socialization, cognitive…
DNA-based approach to aging martens (Martes americana and M. caurina)
Jonathan N. Pauli; John P. Whiteman; Bruce G. Marcot; Terry M. McClean; Merav Ben-David
2011-01-01
Demographic structure is central to understanding the dynamics of animal populations. However, determining the age of free-ranging mammals is difficult, and currently impossible when sampling with noninvasive, genetic-based approaches. We present a method to estimate age class by combining measures of telomere lengths with other biologically meaningful covariates in a...
Familiar, Itziar; Murray, Laura; Gross, Alden; Skavenski, Stephanie; Jere, Elizabeth; Bass, Judith
2014-11-01
Scant information exists on PTSD symptoms and structure in youth from developing countries. We describe the symptom profile and exposure to trauma experiences among 343 orphan and vulnerable children and adolescents from Zambia. We distinguished profiles of post-traumatic stress symptoms using latent class analysis. Average number of trauma-related symptoms (21.6; range 0-38) was similar across sex and age. Latent class model suggested 3 classes varying by level of severity: low (31% of the sample), medium (45% of the sample), and high (24% of the sample) symptomatology. Results suggest that PTSD is a continuously distributed latent trait.
Brooks, Billy; McBee, Matthew; Pack, Robert; Alamian, Arsham
2017-05-01
Rates of accidental overdose mortality from substance use disorder (SUD) have risen dramatically in the United States since 1990. Between 1999 and 2004 alone rates increased 62% nationwide, with rural overdose mortality increasing at a rate 3 times that seen in urban populations. Cultural differences between rural and urban populations (e.g., educational attainment, unemployment rates, social characteristics, etc.) affect the nature of SUD, leading to disparate risk of overdose across these communities. Multiple-groups latent class analysis with covariates was applied to data from the 2011 and 2012 National Survey on Drug Use and Health (n=12.140) to examine potential differences in latent classifications of SUD between rural and urban adult (aged 18years and older) populations. Nine drug categories were used to identify latent classes of SUD defined by probability of diagnosis within these categories. Once the class structures were established for rural and urban samples, posterior membership probabilities were entered into a multinomial regression analysis of socio-demographic predictors' association with the likelihood of SUD latent class membership. Latent class structures differed across the sub-groups, with the rural sample fitting a 3-class structure (Bootstrap Likelihood Ratio Test P value=0.03) and the urban fitting a 6-class model (Bootstrap Likelihood Ratio Test P value<0.0001). Overall the rural class structure exhibited less diversity in class structure and lower prevalence of SUD in multiple drug categories (e.g. cocaine, hallucinogens, and stimulants). This result supports the hypothesis that different underlying elements exist in the two populations that affect SUD patterns, and thus can inform the development of surveillance instruments, clinical services, and prevention programming tailored to specific communities. Copyright © 2017 Elsevier Ltd. All rights reserved.
Callister, Kate E.; Griffioen, Peter A.; Avitabile, Sarah C.; Haslem, Angie; Kelly, Luke T.; Kenny, Sally A.; Nimmo, Dale G.; Farnsworth, Lisa M.; Taylor, Rick S.; Watson, Simon J.; Bennett, Andrew F.; Clarke, Michael F.
2016-01-01
Understanding the age structure of vegetation is important for effective land management, especially in fire-prone landscapes where the effects of fire can persist for decades and centuries. In many parts of the world, such information is limited due to an inability to map disturbance histories before the availability of satellite images (~1972). Here, we describe a method for creating a spatial model of the age structure of canopy species that established pre-1972. We built predictive neural network models based on remotely sensed data and ecological field survey data. These models determined the relationship between sites of known fire age and remotely sensed data. The predictive model was applied across a 104,000 km2 study region in semi-arid Australia to create a spatial model of vegetation age structure, which is primarily the result of stand-replacing fires which occurred before 1972. An assessment of the predictive capacity of the model using independent validation data showed a significant correlation (rs = 0.64) between predicted and known age at test sites. Application of the model provides valuable insights into the distribution of vegetation age-classes and fire history in the study region. This is a relatively straightforward method which uses widely available data sources that can be applied in other regions to predict age-class distribution beyond the limits imposed by satellite imagery. PMID:27029046
Familiar, Itziar; Murray, Laura; Gross, Alden; Skavenski, Stephanie; Jere, Elizabeth; Bass, Judith
2014-01-01
Background Scant information exists on PTSD symptoms and structure in youth from developing countries. Methods We describe the symptom profile and exposure to trauma experiences among 343 orphan and vulnerable children and adolescents from Zambia. We distinguished profiles of post-traumatic stress symptoms using latent class analysis. Results Average number of trauma-related symptoms (21.6; range 0-38) was similar across sex and age. Latent class model suggested 3 classes varying by level of severity: low (31% of the sample), medium (45% of the sample), and high (24% of the sample) symptomatology. Conclusions Results suggest that PTSD is a continuously distributed latent trait. PMID:25382359
Structural and Cultural Factors in Successful Aging Among Older Hispanics
Angel, Ronald J.
2014-01-01
Successful or healthful aging are terms that draw attention to life course issues related to individual, physical, and psychologic development and maturation, but they also draw attention to the material basis of successful aging and the social structures that determine one’s place in the social hierarchy. This article focuses on barriers to optimal aging for Hispanics, especially those of Mexican origin, and argues that cultural factors and social class are closely associated. The reduction of health disparities and equity in medical and long-term care requires an understanding of both cultural and material sources of differential health levels. PMID:19065093
Caria, Maria Paola; Faggiano, Fabrizio; Bellocco, Rino; Galanti, Maria Rosaria
2013-12-01
Partial implementation may explain modest effectiveness of many school-based preventive programmes against substance use. We studied whether specific characteristics of the class could predict the level of implementation of a curriculum delivered by class teachers in schools from some European countries. Secondary analysis of data from an evaluation trial. In seven European countries, 78 schools (173 classes) were randomly assigned to a 12-unit, interactive, standardized programme based on the comprehensive social influence model. Curriculum completeness, application fidelity, average unit duration and use of role-play were monitored using structured report forms. Predictors of implementation were measured by aggregating at class level information from the baseline student survey. Class size, gender composition, mean age, factors related to substance use and to affection to school were analysed, with associations estimated by multilevel regression models. Implementation was not significantly predicted by mean age, proportion of students with positive academic expectation or liking school. Proportion of boys was associated with a shorter time devoted to each unit [β = -0.19, 95% confidence intervals (CI) -0.32 to -0.06]. Class size was inversely related to application fidelity [Odds ratio (OR) 0.92, 95% CI 0.85 to 0.99]. Prevalence of substance use was associated with a decreased odds of implementing all the curriculum units (OR 0.81, 95% CI 0.65 to 0.99). Students' connectedness to their class was associated with increased odds of teachers using role-play (OR 1.52, 95% CI 1.03 to 2.29). Teachers' implementation of preventive programmes may be affected by structural and social characteristics of classes and therefore benefit from organizational strategies and teachers' training in class management techniques.
Sousa, Carlos; Mateus, Nuno; Perez-Alonso, Joaquín; Santos-Buelga, Celestino; Freitas, Victor de
2005-11-16
Several structurally related pigments were found to result from the reaction between catechin and coniferaldehyde/sinapaldehyde extracted from oak wood. Their structures were tentatively identified by mass spectrometry, and their formation was studied in different pH and temperature conditions for several days. They were all found to have a characteristic catechinpyrylium core, thereby constituting a new class of compounds named as oaklins. One of the main oaklins was also detected in a commercial table red wine aged in oak barrels.
Population characteristics and the suppression of nonnative Burbot
Klein, Zachary B.; Quist, Michael C.; Rhea, Darren T.; Senecal, Anna C.
2016-01-01
Burbot Lota lota were illegally introduced into the Green River, Wyoming, drainage and have since proliferated throughout the system. Burbot in the Green River pose a threat to native species and to socially, economically, and ecologically important recreational fisheries. Therefore, managers of the Green River are interested in implementing a suppression program for Burbot. We collected demographic data on Burbot in the Green River (summer and autumn 2013) and used the information to construct an age-based population model (female-based Leslie matrix) to simulate the population-level response of Burbot to the selective removal of different age-classes. Burbot in the Green River grew faster, matured at relatively young ages, and were highly fecund compared with other Burbot populations within the species’ native distribution. The age-structured population model, in conjunction with demographic information, indicated that the Burbot population in the Green River could be expected to increase under current conditions. The model also indicated that the Burbot population in the Green River would decline once total annual mortality reached 58%. The population growth of Burbot in the Green River was most sensitive to age-0 and age-1 mortality. The age-structured population model indicated that an increase in mortality, particularly for younger age-classes, would result in the effective suppression of the Burbot population in the Green River.
Developing Structural Specification: Productivity in Early Hebrew Verb Usage
ERIC Educational Resources Information Center
Lustigman, Lyle
2013-01-01
The study investigates acquisition of verb inflections by four monolingual Hebrew-acquiring children from middle-class backgrounds, audio-recorded in longitudinal, weekly samples at a mean age-range of between 18 and 26 months. Productive use of inflectional morphology is shown to manifest increasing structural specification, as a function of…
Supporting Girls' Motivation in Science: A Study of Peer- and Self-Assessment in a Girls-Only Class
ERIC Educational Resources Information Center
Johnson, Nadine; Winterbottom, Mark
2011-01-01
This study examines how the use of self- and peer-assessment within a girls-only biology class can support students' motivation. The study took place over 22 weeks in a rural comprehensive school, and the participants were girls between 15 and 16 years of age. Data included questionnaires, semi-structured interviews, notes from lesson observations…
Ecologic Reformulation of Pediatric Social Illness.
ERIC Educational Resources Information Center
Newberger, Eli H.; Marx, Thomas J.
Members of a group of hospitalized children under 4 years of age (48 under care for child abuse, 97 for accidents, 41 for failure to thrive, and 23 for ingestions) were matched individually on age, social class, and race with controls suffering from comparable acute medical conditions. A structured maternal and paternal interview yielded 63…
Allan, Nicholas P.; Raines, Amanda M.; Capron, Daniel W.; Norr, Aaron M.; Zvolensky, Michael J.; Schmidt, Norman B.
2014-01-01
Anxiety sensitivity (AS), a multidimensional construct, has been implicated in the development and maintenance of anxiety and related disorders. Recent evidence suggests that AS is a dimensional-categorical construct within individuals. Factor mixture modeling was conducted in a sample of 579 adult smokers (M age = 36.87 years, SD = 13.47) to examine the underlying structure. Participants completed the Anxiety Sensitivity Index-3 and were also given a Structured Clinical Interview for DSM-IV-TR. Three classes of individuals emerged, a high AS (5.2% of the sample), a moderate AS (19.0%), and a normative AS class (75.8%). A cut-score of 23 to identify high AS individuals, and a cut-score of 17 to identify moderate-to-high AS individuals were supported in this study. In addition, the odds of having a concurrent anxiety disorder (controlling for other Axis I disorders) were the highest in the high AS class and the lowest in the normative AS class. PMID:25128664
Cost-effective age structure and geographical distribution of boreal forest reserves.
Lundström, Johanna; Ohman, Karin; Perhans, Karin; Rönnqvist, Mikael; Gustafsson, Lena; Bugman, Harald
2011-02-01
1. Forest reserves are established to preserve biodiversity, and to maintain natural functions and processes. Today there is heightened focus on old-growth stages, with less attention given to early successional stages. The biodiversity potential of younger forests has been overlooked, and the cost-effectiveness of incorporating different age classes in reserve networks has not yet been studied.2. We performed a reserve selection analysis in boreal Sweden using the Swedish National Forest Inventory plots. Seventeen structural variables were used as biodiversity indicators, and the cost of protecting each plot as a reserve was assessed using the Heureka system. A goal programming approach was applied, which allowed inclusion of several objectives and avoided a situation in which common indicators affected the result more than rare ones. The model was limited either by budget or area.3. All biodiversity indicators were found in all age classes, with more than half having the highest values in ages ≥ 100 years. Several large-tree indicators and all deadwood indicators had higher values in forests 0-14 years than in forests 15-69 years.4. It was most cost-effective to protect a large proportion of young forests since they generally have a lower net present value compared to older forests, but still contain structures of importance for biodiversity. However, it was more area-effective to protect a large proportion of old forests since they have a higher biodiversity potential per area.5. The geographical distribution of reserves selected with the budget-constrained model was strongly biassed towards the north-western section of boreal Sweden, with a large proportion of young forest, whereas the area-constrained model focussed on the south-eastern section, with dominance by the oldest age class.6.Synthesis and applications. We show that young forests with large amounts of structures important to biodiversity such as dead wood and remnant trees are cheap and cost-efficient to protect. This suggests that reserve networks should incorporate sites with high habitat quality of different forest ages. Since young forests are generally neglected in conservation, our approach is of interest also to other forest biomes where biodiversity is adapted to disturbance regimes resulting in open, early successional stages.
Simmons, J.W.; Layzer, J.B.; Smith, D.D.
2008-01-01
The bluemask darter Etheostoma (Doration) sp. is an endangered fish endemic to the upper Caney Fork system in the Cumberland River drainage in central Tennessee. Darters (Etheostoma spp.) are typically short-lived and exhibit rapid growth that quickly decreases with age. Consequently, estimating age of darters from length-frequency distributions can be difficult and subjective. We used a nonparametric kernel density estimator to reduce subjectivity in estimating ages of bluemask darters. Data were collected from a total of 2926 bluemask darters from the Collins River throughout three growing seasons. Additionally, data were collected from 842 bluemask darters from the Rocky River during one growing season. Analysis of length-frequencies indicated the presence of four age classes in both rivers. In each river, the majority of the population was comprised of fish 0.05). In both rivers, females were more abundant than males.
Pettay, Jenni E.; Helle, Samuli; Jokela, Jukka; Lummaa, Virpi
2007-01-01
Life-history theory predicts that resource scarcity constrains individual optimal reproductive strategies and shapes the evolution of life-history traits. In species where the inherited structure of social class may lead to consistent resource differences among family lines, between-class variation in resource availability should select for divergence in optimal reproductive strategies. Evaluating this prediction requires information on the phenotypic selection and quantitative genetics of life-history trait variation in relation to individual lifetime access to resources. Here, we show using path analysis how resource availability, measured as the wealth class of the family, affected the opportunity and intensity of phenotypic selection on the key life-history traits of women living in pre-industrial Finland during the 1800s and 1900s. We found the highest opportunity for total selection and the strongest selection on earlier age at first reproduction in women of the poorest wealth class, whereas selection favoured older age at reproductive cessation in mothers of the wealthier classes. We also found clear differences in female life-history traits across wealth classes: the poorest women had the lowest age-specific survival throughout their lives, they started reproduction later, delivered fewer offspring during their lifetime, ceased reproduction younger, had poorer offspring survival to adulthood and, hence, had lower fitness compared to the wealthier women. Our results show that the amount of wealth affected the selection pressure on female life-history in a pre-industrial human population. PMID:17622351
Justin S. Crotteau; Christopher R. Keyes; Elaine K. Sutherland; David K. Wright; Joel M. Egan
2016-01-01
Variable-retention harvesting in lodgepole pine offers an alternative to conventional, even-aged management. This harvesting technique promotes structural complexity and age-class diversity in residual stands and promotes resilience to disturbance. We examined fuel loads and potential fire behaviour 12 years after two modes of variable-retention harvesting (...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-29
... uncharacteristicly high-severity wild fires, which can lead to loss of entire stands during one fire event. About 67..., fire, and wind. The purpose of the project is to restore forest health, move forests toward an uneven-aged forest structure with all age classes represented, and restore frequent, periodic surface fire as...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Higuchi, Aya E.; Saito, Masao; Mauersberger, Rainer
2013-03-10
We present maps of seven young massive molecular clumps within five target regions in C{sup 18}O (J = 1-0) line emission, using the Nobeyama 45 m telescope. These clumps, which are not associated with clusters, lie at distances between 0.7 and 2.1 kpc. We find C{sup 18}O clumps with radii of 0.5-1.7 pc, masses of 470-4200 M{sub Sun }, and velocity widths of 1.4-3.3 km s{sup -1}. All of the clumps are massive and approximately in virial equilibrium, suggesting they will potentially form clusters. Three of our target regions are associated with H II regions (CWHRs), while the other twomore » are unassociated with H II regions (CWOHRs). The C{sup 18}O clumps can be classified into two morphological types: CWHRs with a filamentary or shell-like structure and spherical CWOHRs. The two CWOHRs have systematic velocity gradients. Using the publicly released WISE database, Class I and Class II protostellar candidates are identified within the C{sup 18}O clumps. The fraction of Class I candidates among all YSO candidates (Class I+Class II) is {>=}50% in CWHRs and {<=}50% in CWOHRs. We conclude that effects from the H II regions can be seen in (1) the spatial distributions of the clumps: filamentary or shell-like structure running along the H II regions; (2) the velocity structures of the clumps: large velocity dispersion along shells; and (3) the small age spreads of YSOs. The small spreads in age of the YSOs show that the presence of H II regions tends to trigger coeval cluster formation.« less
Cho, Gun-Sang; Kim, Dae-Sung; Yi, Eun-Surk
2015-12-01
The purpose of this study is to verification of relationship model between Korean new elderly class's recovery resilience and productive aging. As of 2013, this study sampled preliminary elderly people in Gyeonggi-do and other provinces nationwide. Data from a total of effective 484 subjects was analyzed. The collected data was processed using the IBM SPSS 20.0 and AMOS 20.0, and underwent descriptive statistical analysis, confirmatory factor analysis, and structure model verification. The path coefficient associated with model fitness was examined. The standardization path coefficient between recovery resilience and productive aging is β=0.975 (t=14.790), revealing a statistically significant positive effect. Thus, it was found that the proposed basic model on the direct path of recovery resilience and productive aging was fit for the model.
ERIC Educational Resources Information Center
Papageorgiou, George; Markos, Angelos; Zarkadis, Nikolaos
2016-01-01
The current study aims to investigate students' representations of the atomic structure in a number of student cohorts with specific characteristics concerning age, grade, class curriculum and some individual differences, such as formal reasoning and field dependence/independence. Two specific task contexts, which were designed in accordance with…
ERIC Educational Resources Information Center
Hong, Song-Iee; Hasche, Leslie; Bowland, Sharon
2009-01-01
Purpose: This study examines the structural relationships between social activities and trajectories of late-life depression. Design and Methods: Latent class analysis was used with a nationally representative sample of older adults (N = 5,294) from the Longitudinal Study on Aging II to classify patterns of social activities. A latent growth curve…
The effect of excluding juveniles on apparent adult olive baboons (Papio anubis) social networks
Fedurek, Piotr; Lehmann, Julia
2017-01-01
In recent years there has been much interest in investigating the social structure of group living animals using social network analysis. Many studies so far have focused on the social networks of adults, often excluding younger, immature group members. This potentially may lead to a biased view of group social structure as multiple recent studies have shown that younger group members can significantly contribute to group structure. As proof of the concept, we address this issue by investigating social network structure with and without juveniles in wild olive baboons (Papio anubis) at Gashaka Gumti National Park, Nigeria. Two social networks including all independently moving individuals (i.e., excluding dependent juveniles) were created based on aggressive and grooming behaviour. We used knockout simulations based on the random removal of individuals from the network in order to investigate to what extent the exclusion of juveniles affects the resulting network structure and our interpretation of age-sex specific social roles. We found that juvenile social patterns differed from those of adults and that the exclusion of juveniles from the network significantly altered the resulting overall network structure. Moreover, the removal of juveniles from the network affected individuals in specific age-sex classes differently: for example, including juveniles in the grooming network increased network centrality of adult females while decreasing centrality of adult males. These results suggest that excluding juveniles from the analysis may not only result in a distorted picture of the overall social structure but also may mask some of the social roles of individuals belonging to different age-sex classes. PMID:28323851
The effect of excluding juveniles on apparent adult olive baboons (Papio anubis) social networks.
Fedurek, Piotr; Lehmann, Julia
2017-01-01
In recent years there has been much interest in investigating the social structure of group living animals using social network analysis. Many studies so far have focused on the social networks of adults, often excluding younger, immature group members. This potentially may lead to a biased view of group social structure as multiple recent studies have shown that younger group members can significantly contribute to group structure. As proof of the concept, we address this issue by investigating social network structure with and without juveniles in wild olive baboons (Papio anubis) at Gashaka Gumti National Park, Nigeria. Two social networks including all independently moving individuals (i.e., excluding dependent juveniles) were created based on aggressive and grooming behaviour. We used knockout simulations based on the random removal of individuals from the network in order to investigate to what extent the exclusion of juveniles affects the resulting network structure and our interpretation of age-sex specific social roles. We found that juvenile social patterns differed from those of adults and that the exclusion of juveniles from the network significantly altered the resulting overall network structure. Moreover, the removal of juveniles from the network affected individuals in specific age-sex classes differently: for example, including juveniles in the grooming network increased network centrality of adult females while decreasing centrality of adult males. These results suggest that excluding juveniles from the analysis may not only result in a distorted picture of the overall social structure but also may mask some of the social roles of individuals belonging to different age-sex classes.
Yield Tables and Stand Structure for Unthinned Longleaf Pine Plantations in Louisiana and Texas
Richard E. Longrey; Robert L. Bailey
1977-01-01
A system of equations is developed to forecast number of trees per acre, basal area, and cubic foot yields in eight volume categories by l-inch diameter classes for several combinations of site index, age from planting, and either number of trees planted, number of trees surviving, or basal area at a given age.
The evolution of antibiotic resistance in a structured host population.
Blanquart, François; Lehtinen, Sonja; Lipsitch, Marc; Fraser, Christophe
2018-06-01
The evolution of antibiotic resistance in opportunistic pathogens such as Streptococcus pneumoniae , Escherichia coli or Staphylococcus aureus is a major public health problem, as infection with resistant strains leads to prolonged hospital stay and increased risk of death. Here, we develop a new model of the evolution of antibiotic resistance in a commensal bacterial population adapting to a heterogeneous host population composed of untreated and treated hosts, and structured in different host classes with different antibiotic use. Examples of host classes include age groups and geographic locations. Explicitly modelling the antibiotic treatment reveals that the emergence of a resistant strain is favoured by more frequent but shorter antibiotic courses, and by higher transmission rates. In addition, in a structured host population, localized transmission in host classes promotes both local adaptation of the bacterial population and the global maintenance of coexistence between sensitive and resistant strains. When transmission rates are heterogeneous across host classes, resistant strains evolve more readily in core groups of transmission. These findings have implications for the better management of antibiotic resistance: reducing the rate at which individuals receive antibiotics is more effective to reduce resistance than reducing the duration of treatment. Reducing the rate of treatment in a targeted class of the host population allows greater reduction in resistance, but determining which class to target is difficult in practice. © 2018 The Authors.
Allan, Nicholas P; Raines, Amanda M; Capron, Daniel W; Norr, Aaron M; Zvolensky, Michael J; Schmidt, Norman B
2014-10-01
Anxiety sensitivity (AS), a multidimensional construct, has been implicated in the development and maintenance of anxiety and related disorders. Recent evidence suggests that AS is a dimensional-categorical construct within individuals. Factor mixture modeling was conducted in a sample of 579 adult smokers (M age=36.87 years, SD=13.47) to examine the underlying structure. Participants completed the Anxiety Sensitivity Index-3 and were also given a Structured Clinical Interview for DSM-IV-TR. Three classes of individuals emerged, a high AS (5.2% of the sample), a moderate AS (19.0%), and a normative AS class (75.8%). A cut-score of 23 to identify high AS individuals, and a cut-score of 17 to identify moderate-to-high AS individuals were supported in this study. In addition, the odds of having a concurrent anxiety disorder (controlling for other Axis I disorders) were the highest in the high AS class and the lowest in the normative AS class. Copyright © 2014 Elsevier Ltd. All rights reserved.
Shaw, S. L.; Chipps, Steven R.; Windels, Steve K.; Webb, M.A.H.; McLeod, D. T.; Willis, D.W.
2012-01-01
Quantified were the age, growth, mortality and reproductive structure of lake sturgeon (Acipenser fulvescens) collected in the US and Canadian waters of the Namakan Reservoir. The hypotheses were tested that (i) age and growth of lake sturgeon in the Namakan Reservoir would differ by sex and reproductive stage of maturity, and (ii) that the relative strength of year-classes of lake sturgeon in the reservoir would be affected by environmental variables. To quantify age, growth and mortality of the population, existing data was used from a multi-agency database containing information on all lake sturgeon sampled in the reservoir from 2004 to 2009. Lake sturgeon were sampled in the Minnesota and Ontario waters of the Namakan Reservoir using multi-filament gillnets 1.8 m high and 30–100 m long and varying in mesh size from 178 to 356 mm stretch. Reproductive structure of the lake sturgeon was assessed only during spring 2008 and 2009 using plasma testosterone and estradiol-17β concentrations. Ages of lake sturgeon >75 cm ranged from 9 to 86 years (n = 533, mean = 36 years). A catch-curve analysis using the 1981–1953 year classes estimated total annual mortality of adults to be 4.8% and annual survival as 95.2%. Using logistic regression analysis, it was found that total annual precipitation was positively associated with lake sturgeon year-class strength in the Namakan Reservoir. A 10 cm increase in total annual precipitation was associated with at least a 39% increase in the odds of occurrence of a strong year class of lake sturgeon in the reservoir. Plasma steroid analysis revealed a sex ratio of 2.4 females: 1 male and, on average, 10% of female and 30% of male lake sturgeon were reproductively mature each year (i.e. potential spawners). Moreover, there was evidence based on re-captured male fish of both periodic and annual spawning, as well as the ability of males to rapidly undergo gonadal maturation prior to spawning. Knowledge of lake sturgeon reproductive structure and factors influencing recruitment success contribute to the widespread conservation efforts for this threatened species.
The role of population inertia in predicting the outcome of stage-structured biological invasions.
Guiver, Chris; Dreiwi, Hanan; Filannino, Donna-Maria; Hodgson, Dave; Lloyd, Stephanie; Townley, Stuart
2015-07-01
Deterministic dynamic models for coupled resident and invader populations are considered with the purpose of finding quantities that are effective at predicting when the invasive population will become established asymptotically. A key feature of the models considered is the stage-structure, meaning that the populations are described by vectors of discrete developmental stage- or age-classes. The vector structure permits exotic transient behaviour-phenomena not encountered in scalar models. Analysis using a linear Lyapunov function demonstrates that for the class of population models considered, a large so-called population inertia is indicative of successful invasion. Population inertia is an indicator of transient growth or decline. Furthermore, for the class of models considered, we find that the so-called invasion exponent, an existing index used in models for invasion, is not always a reliable comparative indicator of successful invasion. We highlight these findings through numerical examples and a biological interpretation of why this might be the case is discussed. Copyright © 2015. Published by Elsevier Inc.
Ramirez-Valles, J; Zimmerman, M A; Newcomb, M D
1998-09-01
Sexual activity among high-school-aged youths has steadily increased since the 1970s, emerging as a significant public health concern. Yet, patterns of youth sexual risk behavior are shaped by social class, race, and gender. Based on sociological theories of financial deprivation and collective socialization, we develop and test a model of the relationships among neighborhood poverty; family structure and social class position; parental involvement; prosocial activities; race; and gender as they predict youth sexual risk behavior. We employ structural equation modeling to test this model on a cross-sectional sample of 370 sexually active high-school students from a midwestern city; 57 percent (n = 209) are males and 86 percent are African American. We find that family structure indirectly predicts sexual risk behavior through neighborhood poverty, parental involvement, and prosocial activities. In addition, family class position indirectly predicts sexual risk behavior through neighborhood poverty and prosocial activities. We address implications for theory and health promotion.
Parental monitoring trajectories and gambling among a longitudinal cohort of urban youth
Lee, Grace P.; Stuart, Elizabeth A.; Ialongo, Nicholas S.; Martins, Silvia S.
2013-01-01
Aim To test the strength of the association between parental monitoring trajectories throughout early adolescence (ages 11–14) and gambling behaviors by young adulthood (age 22). Design Longitudinal cohort design. Setting Baltimore, Maryland. Participants The sample of 514 participants with gambling data between ages 16–22 and parental monitoring data between ages 11–14, were predominantly African American and received subsidized lunches at age 6. Measurements The South Oaks Gambling Screen and South Oaks Gambling Screen-Revised for Adolescents collected self-reports on annual gambling and gambling problems between ages 16–22. The Parental Monitoring Subscale of the Structured Interview of Parent Management Skills and Practices-Youth Version collected self-reports on annual parental monitoring between ages 11–14. Findings General growth mixture modeling identified two parental monitoring trajectories: 1) “Stable” class (84.9%) began with a high level of parental monitoring at age 11 that remained steady through age 14; 2) “Declining” class (15.1%) began with a significantly lower level of parental monitoring at age 11 and experienced a significant decline through age 14. The Declining class had significantly increased unadjusted (OR=1.91; 95% CI=1.59,2.23; p=<.001) and adjusted (aOR=1.57; 95% CI=1.24,1.99; p=.01) odds of problem gambling as compared with nongambling. Conclusion Low and/or declining parental monitoring of children between the ages of 11 and 14 is significantly associated with problem gambling when those children reach young adulthood. PMID:24321006
Mike Hillis; Vick Applegate; Steve Slaughter; Michael G. Harrington; Helen Smith
2001-01-01
Forest Service land managers, with the collaborative assistance from research, applied a disturbance based restoration strategy to rehabilitate a greatly-altered, high risk Northern Rocky Mountain old-forest ponderosa pine-Douglas-fir stand. Age-class structure and fire history for the site have been documented in two research papers (Arno and others 1995, 1997)....
Effect of seedbed preparation on natural reproduction of spruce and hemlock under dense shade
Grant Davis; Arthur C. Hart
1961-01-01
The cutting practices commonly recommended for spruce-fir stands in the Northeast involve uneven-aged management. The success of this type of management is predicated upon stand structures that have a range of size classes from seedlings to mature trees in intimate mixture. This kind of stand structure requires a continuous supply of reproduction of desirable species....
Spatial characteristics of early successional habitat across the Upper Great Lakes states
Brian G. Tavernia; Mark D. Nelson; James D. Garner; Charles H. (Hobie) Perry
2016-01-01
Creation and management of early successional forest (ESF) is needed to halt and reverse declines of bird species dependent on pioneering plant species or young forests. ESF-dependent bird species require specific structural forest classes and are sensitive to forest age (a surrogate for forest structure), patch size, proximity to patch edges, and the juxtaposition of...
Historical range of variability in live and dead wood biomass: a regional-scale simulation study
Etsuko Nonaka; Thomas A. Spies; Michael C. Wimberly; Janet L. Ohmann
2007-01-01
The historical range of variability (HRV) in landscape structure and composition created by natural disturbance can serve as a general guide for evaluating ecological conditions of managed landscapes. HRV approaches to evaluating landscapes have been based on age classes or developmental stages, which may obscure variation in live and dead stand structure. Developing...
Cost-effective age structure and geographical distribution of boreal forest reserves
Lundström, Johanna; Öhman, Karin; Perhans, Karin; Rönnqvist, Mikael; Gustafsson, Lena; Bugman, Harald
2011-01-01
1. Forest reserves are established to preserve biodiversity, and to maintain natural functions and processes. Today there is heightened focus on old-growth stages, with less attention given to early successional stages. The biodiversity potential of younger forests has been overlooked, and the cost-effectiveness of incorporating different age classes in reserve networks has not yet been studied. 2. We performed a reserve selection analysis in boreal Sweden using the Swedish National Forest Inventory plots. Seventeen structural variables were used as biodiversity indicators, and the cost of protecting each plot as a reserve was assessed using the Heureka system. A goal programming approach was applied, which allowed inclusion of several objectives and avoided a situation in which common indicators affected the result more than rare ones. The model was limited either by budget or area. 3. All biodiversity indicators were found in all age classes, with more than half having the highest values in ages ≥ 100 years. Several large-tree indicators and all deadwood indicators had higher values in forests 0–14 years than in forests 15–69 years. 4. It was most cost-effective to protect a large proportion of young forests since they generally have a lower net present value compared to older forests, but still contain structures of importance for biodiversity. However, it was more area-effective to protect a large proportion of old forests since they have a higher biodiversity potential per area. 5. The geographical distribution of reserves selected with the budget-constrained model was strongly biassed towards the north-western section of boreal Sweden, with a large proportion of young forest, whereas the area-constrained model focussed on the south-eastern section, with dominance by the oldest age class. 6. Synthesis and applications. We show that young forests with large amounts of structures important to biodiversity such as dead wood and remnant trees are cheap and cost-efficient to protect. This suggests that reserve networks should incorporate sites with high habitat quality of different forest ages. Since young forests are generally neglected in conservation, our approach is of interest also to other forest biomes where biodiversity is adapted to disturbance regimes resulting in open, early successional stages. PMID:22879680
The contribution of social behaviour to the transmission of influenza A in a human population.
Kucharski, Adam J; Kwok, Kin O; Wei, Vivian W I; Cowling, Benjamin J; Read, Jonathan M; Lessler, Justin; Cummings, Derek A; Riley, Steven
2014-06-01
Variability in the risk of transmission for respiratory pathogens can result from several factors, including the intrinsic properties of the pathogen, the immune state of the host and the host's behaviour. It has been proposed that self-reported social mixing patterns can explain the behavioural component of this variability, with simulated intervention studies based on these data used routinely to inform public health policy. However, in the absence of robust studies with biological endpoints for individuals, it is unclear how age and social behaviour contribute to infection risk. To examine how the structure and nature of social contacts influenced infection risk over the course of a single epidemic, we designed a flexible disease modelling framework: the population was divided into a series of increasingly detailed age and social contact classes, with the transmissibility of each age-contact class determined by the average contacts of that class. Fitting the models to serologically confirmed infection data from the 2009 Hong Kong influenza A/H1N1p pandemic, we found that an individual's risk of infection was influenced strongly by the average reported social mixing behaviour of their age group, rather than by their personal reported contacts. We also identified the resolution of social mixing that shaped transmission: epidemic dynamics were driven by intense contacts between children, a post-childhood drop in risky contacts and a subsequent rise in contacts for individuals aged 35-50. Our results demonstrate that self-reported social contact surveys can account for age-associated heterogeneity in the transmission of a respiratory pathogen in humans, and show robustly how these individual-level behaviours manifest themselves through assortative age groups. Our results suggest it is possible to profile the social structure of different populations and to use these aggregated data to predict their inherent transmission potential.
The second missing link: Bible nursing in 19th century London.
Denny, E
1997-12-01
The London Bible and Domestic Female Mission was founded in 1857 by Ellen Ranyard. A nursing mission was added in 1868. The structure and work of the mission can be used to exemplify three strategies utilized in Victorian philanthropy. First, the use of working class women in the maintenance of social order, secondly the utilization of the middle class household to exemplify relations between the social classes, and thirdly the creation of districts in an attempt to recreate a 'golden age' of rural communities. Ranyard created a women's mission to women. As such it did not display the gender division of labour apparent in much health and caring work, but a hierarchical division of labour based on social class is evident.
Yavarifard, Roya; Ghavi Hossein-Zadeh, Navid; Shadparvar, Abdol Ahad
2014-01-01
The objective of this study was to describe the population structure and inbreeding, and to quantify their effects on weights at different ages of Mehraban sheep in Iran. The analysis was based on the pedigree information of 26990 animals and 10278 body weight records from birth to yearling age. Data and pedigree information were collected during 1994 to 2011 by the breeding station of Mehraban sheep. The population structure was analyzed using the CFC program. Inbreeding of all animals was calculated by INBUPGF90 program. All animals were grouped into three classes according to their inbreeding coefficients: the first class included non-inbred animals (F=0); and the second and third classes included inbred animals (0
Gualtieri, Fulvio; Manetti, Dina; Romanelli, Maria Novella; Ghelardini, Carla
2002-01-01
Cognition enhancers are drugs able to facilitate attentional abilities and acquisition, storage and retrieval of information, and to attenuate the impairment of cognitive functions associated with head traumas, stroke, age and age-related pathologies. Development of cognition enhancers is still a difficult task because of complexity of the brain functions, poor predictivity of animal tests and lengthy and expensive clinical trials. After the early serendipitous discovery of first generation cognition enhancers, current research is based on a variety of working hypotheses, derived from the progress of knowledge in the neurobiopathology of cognitive processes. Among other classes of drugs, piracetam-like cognition enhancers (nootropics) have never reached general acceptance, in spite of their excellent tolerability and safety. In the present review, after a general discussion of the problems connected with the design and development of cognition enhancers, the class is examined in more detail. Reasons for the problems encountered by nootropics, compounds therapeutically available and those in development, their structure activity relationships and mechanisms of action are discussed. Recent developments which hopefully will lead to a revival of the class are reviewed.
Histological determination of the human origin from dry bone: a cautionary note for subadults.
Caccia, Giulia; Magli, Francesca; Tagi, Veronica Maria; Porta, Davide Guido Ampelio; Cummaudo, Marco; Márquez-Grant, Nicholas; Cattaneo, Cristina
2016-01-01
Anthropologists are frequently required to confirm or exclude the human origin of skeletal remains; DNA and protein radioimmunoassays are useful in confirming the human origin of bone fragments but are not always successful. Histology may be the solution, but the young subadult structure could create misinterpretation. Histological tests were conducted on femur and skull of 31 human subjects. Each sample was observed focusing on presence or absence of fibrous bone, lamellar bone, radial lamellar bone, plexiform bone, reticular pattern, osteon banding, Haversian bone, primary osteons, secondary osteon and osteon fragments. Samples were divided into five age classes; 1 (<1 year), 2 (1-5 years), 3 (6-10 years), 4 (11-15 years) and 5 (16-20 years). Regarding femurs, class 1 presented the following: 87.5% fibrous bone, 37.5% plexiform bone, 12.5% reticular pattern and 12.5% lamellar bone radially oriented. Class 2 showed 37.5% of fibrous bone, 12.5% of reticular pattern and 37.5% of osteon banding. In the higher age classes, the classical human structures, lamellar bone and osteons were frequently visible, except for one case of reticular pattern, generally considered a distinctive non-human structure. The situation appeared different for the skull, where there was a lack of similar information, both in human and non-human. An analysis of the percentage of lamellar bone and osteons was conducted on femur and skull fragments. A trend of increase of primary osteon number and a decrease of the lamellar bone area has been detected in the femur. The present study has therefore shed some light on further pitfalls in species determination of subadult bone.
BIOACCUMULATION AND AQUATIC SYSTEM SIMULATOR (BASS) USER'S MANUAL BETA TEST VERSION 2.1
BASS (Bioaccumulation and Aquatic System Simulator) is a Fortran 95 simulation program that predicts the population and bioaccumulation dynamics of age-structured fish assemblages that are exposed to hydrophobic organic pollutants and class B and borderline metals that complex wi...
Selvi, Yavuz; Boysan, Murat; Kandeger, Ali; Uygur, Omer F; Sayin, Ayca A; Akbaba, Nursel; Koc, Basak
2018-08-01
The current study aimed at investigating the latent dimensional structure of sleep quality as indexed by the seven components of the Pittsburgh Sleep Quality Index (PSQI), as well as latent covariance structure between sleep quality, circadian preferences and depressive symptoms. Two hundred twenty-five patients with major depressive disorder (MDD), with an average age of 29.92 ± 10.49 years (aged between 17 and 63), participated in the study. The PSQI, Morningness-Eveningness Questionnaire (MEQ) and Beck Depression Inventory (BDI) were administered to participants. Four sets of latent class analyses were subsequently run to obtain optimal number of latent classes best fit to the data. Mixture models revealed that sleep quality is multifaceted in MDD. The data best fit to four-latent-class model: Poor Habitual Sleep Quality (PHSQ), Poor Subjective Sleep Quality (PSSQ), Intermediate Sleep Quality (ISQ), and Good Sleep Quality (GSQ). MDD patients classified into GSQ latent class (23.6%) reported the lowest depressive symptoms and were more prone to morningness diurnal preferences compared to other three homogenous sub-groups. Finally, the significant association between eveningness diurnal preferences and depressive symptomatology was significantly mediated by poor sleep quality. The cross-sectional nature of the study and the lack of an objective measurement of sleep such as polysomnography recordings was the most striking limitation of the study. We concluded sleep quality in relation to circadian preferences and depressive symptoms has a heterogeneous nature in MDD. Copyright © 2018. Published by Elsevier B.V.
Rathmann, Katharina; Herke, Max G; Hurrelmann, Klaus; Richter, Matthias
2018-01-01
The aim of this study is to examine the impact of class-level class climate on school-aged children's life satisfaction. Data was derived from the German National Educational Panel Study (NEPS) using sixth grade school-aged children (n = 4,764, 483 classes). Class climate includes indicators of teachers' care and monitoring, demands, interaction, autonomy, as well as school-aged children's attitudes towards schoolwork at the class- and individual-level. Results showed that individual perceived class climate in terms of teachers' care and monitoring and autonomy was positively related to life satisfaction, whereas school-related demands were related to lower life satisfaction. Besides teachers' care and monitoring at class-level, indicators of class climate were not associated with school-aged children's life satisfaction, while the individual perceived class climate is more important for life satisfaction.
Herke, Max G.; Hurrelmann, Klaus; Richter, Matthias
2018-01-01
The aim of this study is to examine the impact of class-level class climate on school-aged children’s life satisfaction. Data was derived from the German National Educational Panel Study (NEPS) using sixth grade school-aged children (n = 4,764, 483 classes). Class climate includes indicators of teachers' care and monitoring, demands, interaction, autonomy, as well as school-aged children's attitudes towards schoolwork at the class- and individual-level. Results showed that individual perceived class climate in terms of teachers' care and monitoring and autonomy was positively related to life satisfaction, whereas school-related demands were related to lower life satisfaction. Besides teachers' care and monitoring at class-level, indicators of class climate were not associated with school-aged children’s life satisfaction, while the individual perceived class climate is more important for life satisfaction. PMID:29420540
Making the Invisible Visible: Things Aren't What They Seem to Be!
ERIC Educational Resources Information Center
Gikopoulou, Rania
2017-01-01
Rania Gikopoulou is a primary school teacher and post-doctoral researcher at the National and Kapodistrian University of Athens. In this article she describes how her 5th grade class (Age 11) learned about abstract phenomena through models of their microscopic structure.
Dynamics of two-strain influenza model with cross-immunity and no quarantine class.
Chung, K W; Lui, Roger
2016-12-01
The question about whether a periodic solution can exists for a given epidemiological model is a complicated one and has a long history (Hethcote and Levin, Applied math. ecology, biomathematics, vol 18. Springer, Berlin, pp 193-211, 1989). For influenza models, it is well known that a periodic solution can exists for a single-strain model with periodic contact rate (Aron and Schwartz, J Math Biol 110:665-679, 1984; Kuznetsov and Piccardi, J Math Biol 32:109-121, 1994), or a multiple-strain model with cross-immunity and quarantine class or age-structure (Nuño et al., Mathematical epidemiology. Lecture notes in mathematics, vol 1945. Springer, Berlin, 2008, chapter 13). In this paper, we prove the local asymptotic stability of the interior steady-state of a two-strain influenza model with sufficiently close cross-immunity and no quarantine class or age-structure. We also show that if the cross-immunity between two strains are far apart; then it is possible for the interior steady-state to lose its stability and bifurcation of periodic solutions can occur. Our results extend those obtained by Nuño et.al. (SIAM J Appl Math 65:964-982, 2005). This problem is important because understanding the reasons behind periodic outbreaks of seasonal flu is an important issue in public health.
Heilmann, Monika; Wellner, Anne; Gadermaier, Gabriele; Ilchmann, Anne; Briza, Peter; Krause, Maren; Nagai, Ryoji; Burgdorf, Sven; Scheurer, Stephan; Vieths, Stefan; Henle, Thomas; Toda, Masako
2014-01-01
The Maillard reaction (also referred to as “glycation”) takes place between reducing sugars and compounds with free amino groups during thermal processing of foods. In the final stage of the complex reaction cascade, the so-called advanced glycation end products (AGEs) are formed, including proteins with various glycation structures. It has been suggested that some AGEs could have immunostimulatory effects. Here, we aimed to identify specific glycation structure(s) that could influence the T-cell immunogenicity and potential allergenicity of food allergens, using ovalbumin (OVA, an egg white allergen) as a model allergen. OVA was specifically modified with representative glycation structures: Nϵ-carboxymethyl lysine (CM-OVA), Nϵ-carboxyethyl lysine (CE-OVA), pyrraline (Pyr-OVA), or methylglyoxal-derived arginine derivatives (MGO-OVA). As well as AGE-OVA, a crude glycation product in thermal incubation of OVA with glucose, only Pyr-OVA, and not other modified OVAs, was efficiently taken up by bone marrow-derived murine dendritic cells (BMDCs). The uptake of Pyr-OVA was reduced in scavenger receptor class A (SR-A)-deficient BMDCs, but not in cells treated with inhibitors of scavenger receptor class B, galectin-3, or blocking antibodies against CD36, suggesting that pyrraline binds to SR-A. Compared with other modified OVAs, Pyr-OVA induced higher activation of OVA-specific CD4+ T-cells in co-culture with BMDCs. Furthermore, compared with native OVA, AGE-OVA and Pyr-OVA induced higher IgE production in mice. Pyrraline could induce better allergen uptake by DCs via association with SR-A and subsequently enhance CD4+ T-cell activation and IgE production. Our findings help us to understand how Maillard reaction enhances the potential allergenicity of food allergens. PMID:24505139
Truong, C; Palmé, A E; Felber, F
2007-01-01
Mountain birch, Betula pubescens ssp. tortuosa, forms the treeline in northern Sweden. A recent shift in the range of the species associated with an elevation of the treeline is commonly attributed to climate warming. Using microsatellite markers, we explored the genetic structure of populations along an altitudinal gradient close to the treeline. Low genetic differentiation was found between populations, whereas high genetic diversity was maintained within populations. High level of gene flow compensated for possible losses of genetic diversity at higher elevations and dissipated the founding effect of newly established populations above the treeline. Spatial autocorrelation analysis showed low spatial genetic structure within populations because of extensive gene flow. At the treeline, significant genetic structure within the juvenile age class at small distances did not persist in the adult age class, indicating recent expansion of young recruits due to the warming of the climate. Finally, seedling performance above the treeline was positively correlated with parameters related to temperature. These data confirm the high migration potential of the species in response to fluctuating environmental conditions and indicate that it is now invading higher altitudes due to the recent warming of the climate.
Hasking, Penelope Anne; Scheier, Lawrence M; Abdallah, Arbi Ben
2011-01-01
This study used latent class analysis to examine subpopulation membership based on self-reports of delinquent behaviors obtained from Australian youth. Three discrete identifiable classes were derived based on 51 indicators of physical violence, property damage, minor infractions, drug use, and social delinquency. One class of youth engaged in primarily rule breaking and norm violations including underage alcohol use, typical of this age period. A second class was more actively delinquent emphasizing drug use, trespassing, and various forms of disobedience. A third class of highly delinquent youth differed from their counterparts by endorsing drug use, thievery that involved stealing money, goods, and cars, property damage, gambling, precocious sexual experiences, involvement with pornographic materials, and fighting. Multinomial logistic regression predicting class membership indicated highly delinquent youth were more likely to be older males, use venting coping strategies, and be fun or novelty seeking compared with rule breakers. Findings are discussed in terms of refining current taxonomic arguments regarding the structure of delinquency and implications for prevention of early-stage antisocial behavior. © 2010 Wiley-Liss, Inc.
Jiang, Ronghuan; Liu, Ru-De; Ding, Yi; Zhen, Rui; Sun, Yan; Fu, Xinchen
2018-01-01
For school-age adolescents, teacher justice plays an important role in their learning and social outcomes. The present study examined the relation between teacher justice and students’ class identification in 1735 Chinese school-age adolescents by considering belief in a just world (BJW) and teacher–student relationship as mediators. Structure equation modeling (SEM) was used to reveal the direct and indirect effects. The analyses showed that all the direct and indirect effects were significant. These findings indicated that teacher justice had a positive effect on students’ class identification. In addition, teacher justice impacted students’ class identification through students’ just-world belief and teacher–student relationships. These results suggested that for adolescents, teacher justice played an important role in shaping their just-world belief system and their interpersonal relationships with teachers, which in turn affected their sense of belonging and values in relation to their class. Thus, it is important for teachers to be aware that their injustice may negatively impact their relationships with students, students’ belief systems, and their psychological engagement at school. There is a need to develop teacher-training programs to help teachers to establish classroom reward-punishment systems with the consideration of social justice, to communicate with students through an unbiased approach, and to increase student participation in the important decision making of the whole class. PMID:29875726
Jiang, Ronghuan; Liu, Ru-De; Ding, Yi; Zhen, Rui; Sun, Yan; Fu, Xinchen
2018-01-01
For school-age adolescents, teacher justice plays an important role in their learning and social outcomes. The present study examined the relation between teacher justice and students' class identification in 1735 Chinese school-age adolescents by considering belief in a just world (BJW) and teacher-student relationship as mediators. Structure equation modeling (SEM) was used to reveal the direct and indirect effects. The analyses showed that all the direct and indirect effects were significant. These findings indicated that teacher justice had a positive effect on students' class identification. In addition, teacher justice impacted students' class identification through students' just-world belief and teacher-student relationships. These results suggested that for adolescents, teacher justice played an important role in shaping their just-world belief system and their interpersonal relationships with teachers, which in turn affected their sense of belonging and values in relation to their class. Thus, it is important for teachers to be aware that their injustice may negatively impact their relationships with students, students' belief systems, and their psychological engagement at school. There is a need to develop teacher-training programs to help teachers to establish classroom reward-punishment systems with the consideration of social justice, to communicate with students through an unbiased approach, and to increase student participation in the important decision making of the whole class.
Burger, L K; Miller, P J
1999-02-01
This study contributes to our understanding of sociocultural variation in children's early storytelling by comparing co-narrations produced by children and their families from two European-American communities, one working-class and one middle-class. Six children from each community were observed in their homes at 2;6 and 3;0 years of age, yielding a corpus of nearly 400 naturally-occurring co-narrations of past experience. Analyses of generic properties, content, and emotion talk revealed a complex configuration of similarities and differences. Working-class and middle-class families produced co-narrations that were similar in referential/evaluative functions and temporal structure, with a preponderance of positive content. Working-class families produced twice as many co-narrations as their middle-class counterparts, produced more negative emotion talk, and used more dramatic language for conveying negative emotional experience. These findings suggest that (1) differentiation between working-class and middle-class communities in the content of early narratives may occur primarily with respect to negative experience and (2) researchers need to go beyond emotion state terms in order to accurately represent sociocultural variation in personal storytelling.
Glendon W. Smalley; Robert L. Bailey
1974-01-01
Detailed schedules of trees per acre, basal area, mean tree height, and cubic-foot yields in eight volume categories by l-inch diameter classes are presented for all combinations of four site indexes, seven ages from seed, and nine planting densities.
ERIC Educational Resources Information Center
Dodge, Tonya; Jaccard, James
2002-01-01
Compared sexual risk behavior of female athletes and nonathletes. Examined mediation, reverse mediation, spurious effects, and moderated causal models, using as potential mediators physical development, educational aspirations, self-esteem, attitudes toward pregnancy, involvement in a romantic relationship, age, ethnicity, and social class. Found…
Franceschini, M C; de Wysiecki, M L; Poi, A
2013-08-01
We aimed to evaluate the variation in the age structure of Cornops aquaticum (Bruner) population and its relation to the host plant biomass and the feeding of the different age classes of this grasshopper on the water hyacinth Eichhornia crassipes along 2 years, in a Paraná River floodplain lake (Chaco, Argentina). Individuals of C. aquaticum were captured with a 70-cm diameter sweep and separated in nymphs A (instars I and II), nymphs B (instars III to VI), adult females, and adult males; host plant biomass was sampled using a ring with a 0.30-m(2) diameter. Relative daily feeding of C. aquaticum population was calculated by multiplying the number of individuals captured per minute by the daily consumption by individual obtained in each age classes. We found that the age structure and the relative daily feeding of C. aquaticum varied between seasons and years. The highest values of grasshopper abundance, leaf biomass, and relative daily feeding of C. aquaticum population were observed in summer 2006. Plant biomass was directly correlated with nymph abundance and not correlated with adult abundance. Plant biomass available as refuge (leaves), food (laminas), and oviposition site (petioles) to C. aquaticum represented up to 62% of the total plant biomass. The results obtained in C. aquaticum show the importance of considering total plant biomass and plant biomass available for herbivores separately. Our study highlights the need to find an adequate method to estimate the density of C. aquaticum and other semiaquatic grasshoppers in the Paraná River floodplain involving different seasons, years, and water phases (rising and falling).
An Evaluation of Select Physical Activity Exercise Classes on Bone Metabolism.
Stone, Tori M; Wingo, Jonathan E; Young, John C; Navalta, James W
2018-01-01
Weight-bearing physical activity can optimize bone mass early in life and prevent the development of osteoporosis. However, less is known about the potential benefits of non-weight-bearing activities. The purpose of this study was to assess the efficacy of structured physical activity classes on bone metabolism. Twenty-eight premenopausal women, aged 18-35 years who were either enrolled in a yoga class (n=14) or cardio-kickboxing class (n=14) voluntarily consented to participate. Both classes were introductory classes meeting twice per week for 50 min per session for 12 weeks. Anteroposterior spine (L1-L4), hip (dual femur), and total body bone mineral density (BMD) was measured in both groups pre and post intervention using dual-energy X-ray absorptiometry (DXA). Pre and post blood samples were drawn for measurement of serum osteocalcin (OC) by enzyme-linked immunosorbent assay (ELISA) in each group. Baseline subject characteristics including age, height, weight, body fat percentage, and lean body mass did not differ between groups. BMD levels did not increase but were held stable over the course of the intervention. Yoga increased OC by 68% (P < 0.001) and cardio-kickboxing increased OC by 67% (P < 0.001) over the course of the 12-week classes. While 12 weeks of yoga and cardio-kickboxing were insufficient to induce BMD changes, OC levels reflect the bone formation process was initiated, but not yet complete. Increased OC levels suggest the selected physical activity classes provided enough of a stimulus to precipitate a future response of bone growth, assuming exercise training remains constant.
Development of structural health monitoring techniques using dynamics testing
DOE Office of Scientific and Technical Information (OSTI.GOV)
James, G.H. III
Today`s society depends upon many structures (such as aircraft, bridges, wind turbines, offshore platforms, buildings, and nuclear weapons) which are nearing the end of their design lifetime. Since these structures cannot be economically replaced, techniques for structural health monitoring must be developed and implemented. Modal and structural dynamics measurements hold promise for the global non-destructive inspection of a variety of structures since surface measurements of a vibrating structure can provide information about the health of the internal members without costly (or impossible) dismantling of the structure. In order to develop structural health monitoring for application to operational structures, developments inmore » four areas have been undertaken within this project: operational evaluation, diagnostic measurements, information condensation, and damage identification. The developments in each of these four aspects of structural health monitoring have been exercised on a broad range of experimental data. This experimental data has been extracted from structures from several application areas which include aging aircraft, wind energy, aging bridges, offshore structures, structural supports, and mechanical parts. As a result of these advances, Sandia National Laboratories is in a position to perform further advanced development, operational implementation, and technical consulting for a broad class of the nation`s aging infrastructure problems.« less
Age, year‐class strength variability, and partial age validation of Kiyis from Lake Superior
Lepak, Taylor A.; Ogle, Derek H.; Vinson, Mark
2017-01-01
ge estimates of Lake Superior Kiyis Coregonus kiyi from scales and otoliths were compared and 12 years (2003–2014) of length frequency data were examined to assess year‐class strength and validate age estimates. Ages estimated from otoliths were precise and were consistently older than ages estimated from scales. Maximum otolith‐derived ages were 20 years for females and 12 years for males. Age estimates showed high numbers of fish of ages 5, 6, and 11 in 2014, corresponding to the 2009, 2008, and 2003 year‐classes, respectively. Strong 2003 and 2009 year‐classes, along with the 2005 year‐class, were also evident based on distinct modes of age‐1 fish (<110 mm) in the length frequency distributions from 2004, 2010, and 2006, respectively. Modes from these year‐classes were present as progressively larger fish in subsequent years. Few to no age‐1 fish (<110 mm) were present in all other years. Ages estimated from otoliths were generally within 1 year of the ages corresponding to strong year‐classes, at least for age‐5 and older fish, suggesting that Kiyi age may be reliably estimated to within 1 year by careful examination of thin‐sectioned otoliths.
Faculty and Student Attitudes toward the Mixed-Age College Class.
ERIC Educational Resources Information Center
Mishler, Carol; Davenport, Margaret
Attitudes held by younger and older students in mixed-age college classes were surveyed, as were the attitudes of teachers toward the mixed-age classes. Seven campuses in the University of Wisconsin system participated in the survey. Findings for the faculty included the following: faculty preferred an age-mix in class; almost all faculty…
33 CFR 67.25-1 - Class “B” structures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Class âBâ structures. 67.25-1... NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âBâ Requirements § 67.25-1 Class “B” structures. Class “B” structures shall be the structures erected in an area where Class “B...
Intercohort density dependence drives brown trout habitat selection
NASA Astrophysics Data System (ADS)
Ayllón, Daniel; Nicola, Graciela G.; Parra, Irene; Elvira, Benigno; Almodóvar, Ana
2013-01-01
Habitat selection can be viewed as an emergent property of the quality and availability of habitat but also of the number of individuals and the way they compete for its use. Consequently, habitat selection can change across years due to fluctuating resources or to changes in population numbers. However, habitat selection predictive models often do not account for ecological dynamics, especially density dependent processes. In stage-structured population, the strength of density dependent interactions between individuals of different age classes can exert a profound influence on population trajectories and evolutionary processes. In this study, we aimed to assess the effects of fluctuating densities of both older and younger competing life stages on the habitat selection patterns (described as univariate and multivariate resource selection functions) of young-of-the-year, juvenile and adult brown trout Salmo trutta. We observed all age classes were selective in habitat choice but changed their selection patterns across years consistently with variations in the densities of older but not of younger age classes. Trout of an age increased selectivity for positions highly selected by older individuals when their density decreased, but this pattern did not hold when the density of younger age classes varied. It suggests that younger individuals are dominated by older ones but can expand their range of selected habitats when density of competitors decreases, while older trout do not seem to consider the density of younger individuals when distributing themselves even though they can negatively affect their final performance. Since these results may entail critical implications for conservation and management practices based on habitat selection models, further research should involve a wider range of river typologies and/or longer time frames to fully understand the patterns of and the mechanisms underlying the operation of density dependence on brown trout habitat selection.
ERIC Educational Resources Information Center
Santo, Jonathan Bruce; Bukowski, William M.; Stella-Lopez, Luz; Carmago, Gina; Mayman, Shari B.; Adams, Ryan E.
2013-01-01
Multilevel modeling was used to examine contextual variations in the structure of the "self" in a sample of 918 lower- and upper-middle class early adolescents (M age = 10.37 years, SD = 1.19) from a "majority" cultural context (i.e., Barranquilla in the Caribbean region of Colombia) and a "nonmajority" context (i.e.,…
Evaluation of cervical posture of children in skeletal class I, II, and III.
D'Attilio, Michele; Caputi, Sergio; Epifania, Ettore; Festa, Felice; Tecco, Simona
2005-07-01
Previous studies on the relationship between morphological structure of the face and cervical posture have predominantly focused on vertical dimensions of the face. The aim of this study was to investigate whether there are significant differences in cervical posture in subjects with a different sagittal morphology of the face, i.e., a different skeletal class. One hundred twenty (120) children (60 males and 60 females, average age 9.5 yrs., SD+/-0.5) were admitted for orthodontic treatment. Selection criteria was: European ethnic origin, date of birth, considerable skeletal growth potential remaining and an absence of temporomandibular joint dysfunction (TMD). Lateral skull radiographs were taken in mirror position. Subjects were divided into three groups based on their skeletal class. The cephalometric tracings included postural variables. The most interesting findings were: 1. children in skeletal class III showed a significantly lower cervical lordosis angle (p<0.001) than the children in skeletal class I and skeletal class II; 2. children in skeletal class II showed a significantly higher extension of the head upon the spinal column compared to children in skeletal class I and skeletal class III (p<0.001 and p<0.01, respectively). This is probably because the lower part of their spinal column was straighter than those of subjects in skeletal class I and II (p<0.01 and p<0.001, respectively). Significant differences among the three groups were also observed in the inclination of maxillary and mandibular bases to the spinal column. The posture of the neck seems to be strongly associated with the sagittal as well as the vertical structure of the face.
Mustanski, Brian; Andrews, Rebecca; Puckett, Jae A
2016-03-01
To examine the effects of the cumulative victimization experienced by lesbian, gay, bisexual, and transgender youths on mental disorders. We recruited 248 participants from the Chicago, Illinois, area in 7 waves of data collected over 4 years, beginning in 2007 (83.1% retention rate). Mean age at enrollment was 18.7 years, and 54.7% were Black. We measured depression and posttraumatic stress disorder using structured psychiatric interviews. Latent class analyses of victimization over time identified a 4-class solution. Class 1 (65.4%) had low, decreasing victimization. Class 2 (10.3%) had moderate, increasing victimization. Class 3 (5.1%) had high, steady victimization. Class 4 (19.2%) had high, decreasing victimization. Controlling for baseline diagnoses and birth sex, lesbian, gay, bisexual, and transgender youths in classes 2 and 3 were at higher risk for depression than were those in class 1; youths in classes 2, 3, and 4 were at elevated risk for posttraumatic stress disorder. Lesbian, gay, bisexual, and transgender youths with steadily high or increasing levels of victimization from adolescence to early adulthood are at higher risk for depression and posttraumatic stress disorder.
Andrews, Rebecca; Puckett, Jae A.
2016-01-01
Objectives. To examine the effects of the cumulative victimization experienced by lesbian, gay, bisexual, and transgender youths on mental disorders. Methods. We recruited 248 participants from the Chicago, Illinois, area in 7 waves of data collected over 4 years, beginning in 2007 (83.1% retention rate). Mean age at enrollment was 18.7 years, and 54.7% were Black. We measured depression and posttraumatic stress disorder using structured psychiatric interviews. Results. Latent class analyses of victimization over time identified a 4-class solution. Class 1 (65.4%) had low, decreasing victimization. Class 2 (10.3%) had moderate, increasing victimization. Class 3 (5.1%) had high, steady victimization. Class 4 (19.2%) had high, decreasing victimization. Controlling for baseline diagnoses and birth sex, lesbian, gay, bisexual, and transgender youths in classes 2 and 3 were at higher risk for depression than were those in class 1; youths in classes 2, 3, and 4 were at elevated risk for posttraumatic stress disorder. Conclusions. Lesbian, gay, bisexual, and transgender youths with steadily high or increasing levels of victimization from adolescence to early adulthood are at higher risk for depression and posttraumatic stress disorder. PMID:26794175
Generalized fish life-cycle poplulation model and computer program
DOE Office of Scientific and Technical Information (OSTI.GOV)
DeAngelis, D. L.; Van Winkle, W.; Christensen, S. W.
1978-03-01
A generalized fish life-cycle population model and computer program have been prepared to evaluate the long-term effect of changes in mortality in age class 0. The general question concerns what happens to a fishery when density-independent sources of mortality are introduced that act on age class 0, particularly entrainment and impingement at power plants. This paper discusses the model formulation and computer program, including sample results. The population model consists of a system of difference equations involving age-dependent fecundity and survival. The fecundity for each age class is assumed to be a function of both the fraction of females sexuallymore » mature and the weight of females as they enter each age class. Natural mortality for age classes 1 and older is assumed to be independent of population size. Fishing mortality is assumed to vary with the number and weight of fish available to the fishery. Age class 0 is divided into six life stages. The probability of survival for age class 0 is estimated considering both density-independent mortality (natural and power plant) and density-dependent mortality for each life stage. Two types of density-dependent mortality are included. These are cannibalism of each life stage by older age classes and intra-life-stage competition.« less
Zuo, Changyan; Cong, Chao; Wang, Shihui; Gu, Yan
2015-10-01
To compare the difference of corresponding age at cervical vertebral maturation (CVM) stages among different skeletal malocclusions and provide clinic guideline on optimal treatment timing for skeletal malocclusion. Based on ANB angle, 2 575 cephalograms collected from Department of Orthodontics, Peking University School and Hospital of Stomatology from May, 2006 to November, 2014 were classified into skeletal Class I (ANB 0°~5°, 1 317 subjects), Class II (ANB > 5°, 685 subjects) and Class III (ANB < 0°, 573 subjects) groups. CVM stages were evaluated with the modified version of CVM method. Independent sample t test was performed to analyze the difference of age at different CVM stages among various skeletal groups. Significant gender difference of age was found at CS3 to CS6 for skeletal Class I group (P < 0.05), at CS5 and CS6 for skeletal Class II group (P < 0.05), and at CS3 and CS5 for skeletal Class III group (P < 0.05). At CS3 stage, the average age of male in skeletal Class II and skeletal Class III groups was (11.6 ± 1.5) years old and (10.3 ± 1.9) years old, respectively; the average age of females in those two groups was (11.7 ± 1.3) years old and (9.3 ± 1.5) years old, respectively, and significant difference was found in both comparisons (P < 0.05). Compared average age at CS5 and CS6 between skeletal Class II and skeletal Class III groups [the ages of male was (15.1 ± 1.7) and (16.8 ± 1.6) years old, the ages of male was (14.6 ± 1.2) and (15.7 ± 2.5) years old], significant difference was also found (P < 0.05). Significant gender differences were found when evaluated CVM stage and age in skeletal Class I, II and III groups. Significant differences of age at different CVM stage was noted when skeletal Class II was compared with skeletal Class III groups.
Lecture classes in human anatomy: the students' perceptions.
Kar, Maitreyee; Roy, Hironmoy; Ghosh, Anasuya; Tapadar, Arunabha; Chowdhury, Subhramoy; Mukherjee, Pranab; Jana, Tapan Kumar
2013-06-01
The human anatomy, or in brief, the body structure has fascinated man for ages. Due to the information explosion and the increase in specializations, this knowledge is available in a very sketchy manner in high school biology courses. The first comprehensive course on the human anatomy is taught to the first year medical students in medical colleges. This is in keeping with the regulations of the Medical Council of India. The anatomy lecture classes occupy a considerable time of the course, to provide the students with an effective knowledge of the gross anatomy, histology, embryology and the clinical anatomy. On the other hand, the students' feedback regarding the lecture methods and the teaching environment is crucial in judging the efficacy of the present curriculum. To obtain the students' feedback about the environment of the lecture classes, as regards the venue, the teaching and learning aids which are used, the lecture class schedule of the university (the number of classes per week, the durations of the lecture classes, etc.) and the existing departmental practices (display of the class routine in advance, synchronization between the lecture and the practical classes), so that their suggestions could help the faculty in planning the most effective teaching procedures. A semi structured questionnaire was supplied to the students to get their feedback. Most of the students found the air conditioned seminar room's environment to be more comfortable and they supported the existing durations of the lecture hours with the combined use of chalk and a board and overhead projectors (OHPs). The perceptions of the learners helped in modifying the departmental practice in the desired way.
Ilchmann, Anne; Burgdorf, Sven; Scheurer, Stephan; Waibler, Zoe; Nagai, Ryoji; Wellner, Anne; Yamamoto, Yasuhiko; Yamamoto, Hiroshi; Henle, Thomas; Kurts, Christian; Kalinke, Ulrich; Vieths, Stefan; Toda, Masako
2010-01-01
The Maillard reaction occurs between reducing sugars and proteins during thermal processing of foods. It produces chemically glycated proteins termed advanced glycation end products (AGEs). The glycation structures of AGEs are suggested to function as pathogenesis-related immune epitopes in food allergy. This study aimed at defining the T-cell immunogenicity of food AGEs by using ovalbumin (OVA) as a model allergen. AGE-OVA was prepared by means of thermal processing of OVA in the presence of glucose. Activation of OVA-specific CD4(+) T cells by AGE-OVA was evaluated in cocultures with bone marrow-derived murine myeloid dendritic cells (mDCs) as antigen-presenting cells. The uptake mechanisms of mDCs for AGE-OVA were investigated by using inhibitors of putative cell-surface receptors for AGEs, as well as mDCs deficient for these receptors. Compared with the controls (native OVA and OVA thermally processed without glucose), AGE-OVA enhanced the activation of OVA-specific CD4(+) T cells on coculture with mDCs, indicating that the glycation of OVA enhanced the T-cell immunogenicity of the allergen. The mDC uptake of AGE-OVA was significantly higher than that of the controls. We identified scavenger receptor class A type I and II (SR-AI/II) as a mediator of the AGE-OVA uptake, whereas the receptor for AGEs and galectin-3 were not responsible. Importantly, the activation of OVA-specific CD4(+) T cells by AGE-OVA was attenuated on coculture with SR-AI/II-deficient mDCs. SR-AI/II targets AGE-OVA to the MHC class II loading pathway in mDCs, leading to an enhanced CD4(+) T-cell activation. The Maillard reaction might thus play an important role in the T-cell immunogenicity of food allergens. Copyright 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.
Benson, Michaela; Jackson, Emma
2017-06-01
This paper argues that shifts in access to housing - both in relation to rental and ownership - disrupt middle-class reproduction in ways that fundamentally influence class formation. While property ownership has had a long association with middle-class identities, status and distinction, an increasingly competitive rental market alongside inflated property prices has impacted on expectations and anxieties over housing futures. In this paper, we consider two key questions: (1) What happens to middle-class identities under the conditions of this wider structural change? (2) How do the middle classes variously manoeuvre within this? Drawing on empirical research conducted in London, we demonstrate that becoming an owner-occupier may be fractured along lines of class but also along the axes of age, wealth and timing, particularly as this relates to the housing market. It builds on understandings of residential status and place as central to the formation of class, orienting this around the recognition of both people and place as mutable, emphasizing that changing economic and social processes generate new class positionalities and strategies for class reproduction. We argue that these processes are writ large in practices of belonging and claims to place, with wider repercussions within the urban landscape. © London School of Economics and Political Science 2017.
[Age structure and genetic diversity of Homatula pycnolepis in the Nujiang River basin].
Yue, Xing-Jian; Liu, Shao-Ping; Liu, Ming-Dian; Duan, Xin-Bin; Wang, Deng-Qiang; Chen, Da-Qing
2013-08-01
This study examined the age structure of the Loach, Homatula pycnolepis through the otolith growth rings in 204 individual specimens collected from the Xiaomengtong River of the Nujiang River (Salween River) basin in April, 2008. There were only two different age classes, 1 and 2 years of age-no 3 year olds were detected. The age structure of H. pycnolepis was simple. The complete mitochondrial DNA cytochrome b gene sequences (1140) of 80 individuals from 4 populations collected in the Nujiang River drainage were sequenced and a total of 44 variable sites were found among 4 different haplotypes. The global haplotype diversity (Hd) and nucleotide diversity (Pi) were calculated at 0.7595, 0.0151 respectively, and 0, 0 in each population, indicating a consistent lack of genetic diversity in each small population. There was obvious geographic structure in both the Nujiang River basin (NJB) group, and the Nanding River (NDR) group. The genetic distance between NJB and NDR was calculated at 0.0356, suggesting that genetic divergence resulted from long-term isolation of individual population. Such a simple age structure and a lack of genetic diversity in H. pycnolepis may potentially be due to small populations and locale fishing pressures. Accordingly, the results of this study prompt us to recommend that the NJB, NDR and Lancang River populations should be protected as three different evolutionary significant units or separated management units.
Characterizing dispersal patterns in a threatened seabird with limited genetic structure
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...
A method for determining fire history in coniferous forests in the Mountain West
Stephen F. Arno; Kathy M. Sneck
1977-01-01
Describes a method for determining historic fire frequency, intensity, and size from cross sections collected from fire-scarred trees and tree age classes determined through increment borings. Tells how to interpret the influence of fire in stand composition and structure and how to identify effects of modern fire suppression.
A Study: The Relationship of Personality Type to Vocabulary Development.
ERIC Educational Resources Information Center
Covner, Thelma Crockin
To test the hypothesis that aspects of one's personality are associated with expansion of his or her vocabulary, a study focused on thirteen students of various ages who constituted a vocabulary development class. Students were taught techniques for discovering meaning through context or extracting meaning through word structure. Considerable time…
Applied chemical ecology of the mountain pine beetle
Robert A. Progar; Nancy Gillette; Christopher J. Fettig; Kathryn Hrinkevich
2014-01-01
Mountain pine beetle, Dendroctonus ponderosae Hopkins, is a primary agent of forest disturbance in western North America. Episodic outbreaks occur at the convergence of favorable forest age and size class structure and climate patterns. Recent outbreaks have exceeded the historic range of variability of D. ponderosae-caused tree mortality affecting ecosystem goods and...
Elementary Students' Accounts of Optimal Challenge in Physical Education
ERIC Educational Resources Information Center
Mandigo, James L.; Holt, Nicholas L.
2006-01-01
The purpose of this study was to examine elementary school students' accounts of optimal challenge. Twenty-seven children (aged 7-9 years) participated in semi-structured interviews during which they were shown a video-recording of their participation in a physical education class and invited to describe their experiences of optimally challenging…
Using Visual Methods to Understand Physical Activity Maintenance following Cardiac Rehabilitation
Hardcastle, Sarah J.
2015-01-01
Few studies have explored the factors associated with long-term maintenance of exercise following cardiac rehabilitation. The present study used auto-photography and interviews to explore the factors that influence motivation and continued participation in physical activity among post cardiac rehabilitation patients. Twenty-three semi-structured interviews were conducted alongside participant-selected photographs or drawings with participants that had continued participation in physical activity for at least two years following the cardiac rehabilitation programme. Participants were recruited from circuit training classes in East Sussex in the UK. Thematic content analysis revealed seven main themes: fear of death and ill health avoidance, critical incidents, overcoming aging, social influences, being able to enjoy life, provision of routine and structure, enjoyment and psychological well-being. Fear of death, illness avoidance, overcoming aging, and being able to enjoy life were powerful motives for continued participation in exercise. The social nature of the exercise class was also identified as a key facilitator of continued participation. Group-based exercise suited those that continued exercise participation post cardiac rehabilitation and fostered adherence. PMID:26381147
Effect of a fish stock's demographic structure on offspring survival and sensitivity to climate.
Stige, Leif Christian; Yaragina, Natalia A; Langangen, Øystein; Bogstad, Bjarte; Stenseth, Nils Chr; Ottersen, Geir
2017-02-07
Commercial fishing generally removes large and old individuals from fish stocks, reducing mean age and age diversity among spawners. It is feared that these demographic changes lead to lower and more variable recruitment to the stocks. A key proposed pathway is that juvenation and reduced size distribution causes reduced ranges in spawning period, spawning location, and egg buoyancy; this is proposed to lead to reduced spatial distribution of fish eggs and larvae, more homogeneous ambient environmental conditions within each year-class, and reduced buffering against negative environmental influences. However, few, if any, studies have confirmed a causal link from spawning stock demographic structure through egg and larval distribution to year class strength at recruitment. We here show that high mean age and size in the spawning stock of Barents Sea cod (Gadus morhua) is positively associated with high abundance and wide spatiotemporal distribution of cod eggs. We find, however, no support for the hypothesis that a wide egg distribution leads to higher recruitment or a weaker recruitment-temperature correlation. These results are based on statistical analyses of a spatially resolved data set on cod eggs covering a period (1959-1993) with large changes in biomass and demographic structure of spawners. The analyses also account for significant effects of spawning stock biomass and a liver condition index on egg abundance and distribution. Our results suggest that the buffering effect of a geographically wide distribution of eggs and larvae on fish recruitment may be insignificant compared with other impacts.
Parr, Russell T.; Bringolf, Robert B.; Jennings, Cecil A.
2018-01-01
The Atlantic Tripletail Lobotes surinamensis is a popular sport fish for which age and growth data are scarce in general and nonexistent for Georgia (GA), USA, waters. These data are necessary to ensure that management regulations are adequate to protect this species, especially given its popularity as a sport fish. We evaluated whether otoliths and spines were suitable for determining the estimated age (hereafter, “age”) and growth rates of Atlantic Tripletails, and we ascertained whether one method was more accurate than the other. Atlantic Tripletails were sampled by angling and trawling during March 30–August 10, 2009, and March 14–August 6, 2010, in nearshore GA waters of the Atlantic Ocean. During the study, 243 Atlantic Tripletails were captured and sampled for aging structures. Sagittal otoliths and the first dorsal spine were removed from each fish and used to estimate the age and growth rate. Mean differences in TL at age for spine and otolith data were evaluated with ANOVA. Estimated ages for males and females ranged from 1 to 5 years based on otoliths and spines. Both otolith and spine mean TLs at ages 1 and 2 were significantly different from each other as well as all other age‐classes, whereas mean TLs for ages 3–5 were not significantly different. Differences in Atlantic Tripletail TL among the otolith‐ and spine‐derived age‐classes were not significant. Each method used to age Atlantic Tripletails had advantages and disadvantages. Otoliths had higher initial reader agreement than spines, although agreement between the structures was 84.1%. However, otoliths require sacrifice of the fish, whereas a spine can be taken without sacrificing the fish. The lack of concrete life history data and population estimates suggests that when feasible, nonlethal aging methods would be preferred over lethal methods to ensure the survival of Atlantic Tripletail populations.
Capodieci, Agnese; Rivetti, Thomas; Cornoldi, Cesare
2016-08-31
The hypothesis behind this study was that trained teachers using cooperative learning procedures with children in their classroom (aged from 6 to 10 years) can influence the social skills of children with ADHD symptoms and their acceptance by their peers. The study involved 30 children with ADHD symptoms attending 12 different classes, where cooperative learning was adopted in some, and standard practices in others. ADHD children's symptoms, social skills, and cooperative behavior were assessed by means of a teacher's questionnaire, and the social preferences of the children in their class were collected. Changes emerged in teachers' assessments of the children's cooperative behavior in the experimental classes. Improvements in the sociometric status of children with ADHD symptoms were only seen in the cooperative learning classes. These results show the importance of well-structured intervention in classes that include children with ADHD symptoms. Implications of these findings for future intervention are discussed. © The Author(s) 2016.
Lay Americans' views of why scientists disagree with each other.
Johnson, Branden B; Dieckmann, Nathan F
2017-10-01
A survey experiment assessed response to five explanations of scientific disputes: problem complexity, self-interest, values, competence, and process choices (e.g. theories and methods). A US lay sample ( n = 453) did not distinguish interests from values, nor competence from process, as explanations of disputes. Process/competence was rated most likely and interests/values least; all, on average, were deemed likely to explain scientific disputes. Latent class analysis revealed distinct subgroups varying in their explanation preferences, with a more complex latent class structure for participants who had heard of scientific disputes in the past. Scientific positivism and judgments of science's credibility were the strongest predictors of latent class membership, controlling for scientific reasoning, political ideology, confidence in choice, scenario, education, gender, age, and ethnicity. The lack of distinction observed overall between different explanations, as well as within classes, raises challenges for further research on explanations of scientific disputes people find credible and why.
Saint or sinner? Teacher perceptions of a child with traumatic brain injury.
Hawley, C A
2005-01-01
To examine influences on classroom performance and behaviour following traumatic brain injury (TBI). A case-study of one child who suffered a moderate TBI, with frontal brain damage, aged 8, followed up at ages 12 and 13 years. Parents and child were interviewed to establish pre- and post-injury behaviour and functioning. All 19 teachers who taught the child reported on classroom performance, behaviour and educational achievement in each of their subjects. The child completed a comprehensive neuropsychological assessment battery including the Weschler Intelligence Scale for Children (WISC-III(UK)), Children's Memory Scale (CMS) and Vineland Adaptive Behaviour Scales (VABS). This child demonstrated above-average intelligence and good attention/concentration on the CMS. However, he was unable to focus or maintain attention in most classroom situations. His behaviour was erratic and disruptive in class and at home. At 5-year follow-up, his behaviour had deteriorated in both home and school situations, particularly in less structured environments. Teachers of more structured subjects (maths and science) perceived the child as excitable but performing at average or above-average levels, whereas teachers of less structured subjects (art, drama, music) perceived him to be 'attention-seeking' and very disruptive in class. The influences of environmental factors are discussed.
Nomaguchi, Kei; House, Amanda N.
2013-01-01
Although researchers contend that racial-ethnic minorities experience more stress than whites, knowledge of racial-ethnic disparities in parenting stress is limited. Using a pooled time-series analysis of data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998–99 (n = 11,324), we examine racial-ethnic differences in maternal parenting stress, with a focus on structural and cultural explanations and variations by nativity and child age. In kindergarten, black mothers, albeit U.S.-born only, report more parenting stress than white mothers due to structural disadvantages and authoritarian parenting values. The black-white gap increases from kindergarten to third grade, and in third grade, U.S.-born black mothers’ higher stress than white mothers’ persists after controlling for structural and parenting factors. Hispanic and Asian mothers, albeit foreign-born only, report more stress than white mothers at both ages due to structural disadvantages and authoritarian values. Despite structural disadvantages, American Indian mothers report less stress. PMID:24026535
Nomaguchi, Kei; House, Amanda N
2013-01-01
Although researchers contend that racial-ethnic minorities experience more stress than whites, knowledge of racial-ethnic disparities in parenting stress is limited. Using a pooled time-series analysis of data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (n = 11,324), we examine racial-ethnic differences in maternal parenting stress, with a focus on structural and cultural explanations and variations by nativity and child age. In kindergarten, black mothers, albeit U.S.-born only, report more parenting stress than white mothers due to structural disadvantages and authoritarian parenting values. The black-white gap increases from kindergarten to third grade, and in third grade, U.S.-born black mothers' higher stress than white mothers' persists after controlling for structural and parenting factors. Hispanic and Asian mothers, albeit foreign-born only, report more stress than white mothers at both ages due to structural disadvantages and authoritarian values. Despite structural disadvantages, American Indian mothers report less stress.
Consumptive and nonconsumptive effects of cannibalism in fluctuating age-structured populations.
Wissinger, Scott A; Whiteman, Howard H; Denoël, Mathieu; Mumford, Miranda L; Aubee, Catherine B
2010-02-01
Theory and empirical studies suggest that cannibalism in age-structured populations can regulate recruitment depending on the intensity of intraspecific competition between cannibals and victims and the nature of the cannibalism window, i.e., which size classes interact as cannibals and victims. Here we report on a series of experiments that quantify that window for age-structured populations of salamander larvae and paedomorphic adults. We determined body size limits on cannibalism in microcosms and then the consumptive and nonconsumptive (injuries, foraging and activity, diet, growth) effects on victims in mesocosms with seminatural levels of habitat complexity and alternative prey. We found that cannibalism by the largest size classes (paedomorphs and > or = age 3+ yr larvae) occurs mainly on young-of-the-year (YOY) victims. Surviving YOY and other small larvae had increased injuries, reduced activity levels, and reduced growth rates in the presence of cannibals. Data on YOY survival in an experiment in which we manipulated the density of paedomorphs combined with historical data on the number of cannibals in natural populations indicate that dominant cohorts of paedomorphs can cause observed recruitment failures. Dietary data indicate that ontogenetic shifts in diet should preclude strong intraspecific competition between YOY and cannibals in this species. Thus our results are consistent with previous empirical and theoretical work that suggests that recruitment regulation by cannibalism is most likely when YOY are vulnerable to cannibalism but have low dietary overlap with cannibals. Understanding the role of cannibalism in regulating recruitment in salamander populations is timely, given the widespread occurrences of amphibian decline. Previous studies have focused on extrinsic (including anthropogenic) factors that affect amphibian population dynamics, whereas the data presented here combined with long-term field observations suggest the potential for intrinsically driven population cycles.
NASA Technical Reports Server (NTRS)
Cohen, Warren B.; Spies, Thomas A.
1992-01-01
Relationships between spectral and texture variables derived from SPOT HRV 10 m panchromatic and Landsat TM 30 m multispectral data and 16 forest stand structural attributes is evaluated to determine the utility of satellite data for analysis of hemlock forests west of the Cascade Mountains crest in Oregon and Washington, USA. Texture of the HRV data was found to be strongly related to many of the stand attributes evaluated, whereas TM texture was weakly related to all attributes. Data analysis based on regression models indicates that both TM and HRV imagery should yield equally accurate estimates of forest age class and stand structure. It is concluded that the satellite data are a valuable source for estimation of the standard deviation of tree sizes, mean size and density of trees in the upper canopy layers, a structural complexity index, and stand age.
Bilgiç, Fundagül; Hamamci, Orhan; Başaran, Güvenç
2011-11-01
To compare and analyse the effects of activator and Forsus FRD EZ appliances in the treatment of skeletal Class II division I malocclusion. Lateral cephalograms and hand-wrist radiographs were collected from 24 Class II division I growing patients (14 females, 10 males). The patients were randomly divided into two equal groups and either treated with an activator appliance (Mean age 12.67 +/- 1.24 years) or with a Forsus FRD EZ appliance (Mean age 12.31 +/- 1.09 years). Pretreatment and posttreatment cephalometric radiographs were obtained, traced, superimposed and data analysed using paired t-tests and the Wilcoxon signed rank test. The results demonstrated that the Forsus FRD EZ effectively corrected the Class II malocclusion, but the changes were mainly dentoalveolar. The Forsus FRD EZ appliance induced a clockwise rotation of the occlusal plane without significant alteration in the vertical facial dimension. Skeletally, maxillary growth was restricted and pogonion moved forward which improved the profile. The Forsus FRD EZ appliance may be an effective dentoalveolar treatment method to manage a skeletal imbalance and improve the profile in growing patients.
Aging commuter aeroplanes: Fatigue evaluation and control methods
NASA Technical Reports Server (NTRS)
Emmerson, A. J.
1992-01-01
The loss of reliability in aircraft is caused by two broad classes of problems. There are those problems which are self evident and hazardous rather than catastrophic. These are the problem areas where characteristically there have been multiple overhauls, repairs, and replacements, and where aging really means the results of repair ineffectiveness that accumulates. The other class of the problem is the insidious and potentially catastrophic class. It includes the progressive deterioration of items that are not maintained, and often cannot be maintained because the deterioration cannot be seen. It includes the loss of physical properties in adhesives and other organic compounds, corrosion, and the response of repeated loads. Dealt with here is a currently unnecessarily troublesome aspect of that response. Although we must remain concerned about those types of aircraft which have been certified under a design standard or operational rule which embodies the elementary fail-safe concept and which have not been subjected to a subsequent structural audit, the focus here is on types of aircraft for which fatigue and damage tolerance evaluation was not required as a condition of certification.
Child Conduct Problems across Home and School Contexts: A Person-Centered Approach
Sulik, Michael J.; Blair, Clancy; Greenberg, Mark
2018-01-01
To examine patterns of conduct problems across the home and school context, we used latent class analysis to analyze primary caregivers' and teachers' ratings on the conduct problems subscale of the Strengths and Difficulties Questionnaire (R. Goodman, 1997) in the Family Life Project (N = 1,292), a prospective study of child development in rural and small town contexts. We found a similar four-class solution at five and seven years of age. In decreasing prevalence, the following classes were identified: (1) low symptoms reported by both informants (low cross-context); (2) high parent-reported symptoms, low teacher-reported symptoms (home context); (3) low parent-reported symptoms, moderate teacher-reported symptoms (school context); and (4) high symptoms reported by both informants (high cross-context). Classes exhibited stability from age five to age seven: children were more likely to remain in the same class than to transition to a different class, and longitudinal stability was especially high for children in the low cross-context class at age 5. A number of child and family characteristics measured in early childhood (executive function, verbal ability, poverty-related risk, sensitive parenting, and parental depressive symptoms) were associated with class membership at age five and age seven, but were generally not associated with longitudinal transitions between classes. PMID:29720784
Choe, Daniel Ewon; Olson, Sheryl L.; Sameroff, Arnold J.
2013-01-01
This study examined bidirectional associations between mothers’ depressive symptoms and children’s externalizing behavior and whether they were moderated by preschool-age effortful control and gender. Mothers and teachers reported on 224 primarily White, middle-class children at ages 3, 5, and 10. Effortful control was assessed via behavioral battery and mother ratings. Structural equation modeling indicated that maternal depressive symptoms at child age 3 predicted more externalizing behavior at age 10 among children with low effortful control and among boys. Externalizing behavior at age 3 predicted fewer depressive symptoms at the age 10 assessments among mothers of children with high effortful control. Boys with suboptimal self-regulation exposed to high levels of maternal depressive symptoms were at greatest risk for school-age behavioral problems. PMID:23668713
ERIC Educational Resources Information Center
Pratt, Michael W.; Norris, Joan E.; Alisat, Susan; Bisson, Elise
2013-01-01
Erikson's construct of generative concern for future generations seems a plausible structure for supporting environmental behavior and socialization in the family. The present study of 44 Canadian middle-class families with a focal child aged 14-16 years, examined variations in generative concern among parents and their children and tested how…
Peer Review and Nuanced Power Structures: Writing and Learning within the Age of Connectivism
ERIC Educational Resources Information Center
Abrams, Sandra Schamroth
2013-01-01
Through a Foucauldian lens, this article examines the affordances and constraints of an online peer-review program in four special education English language arts classes in two New York City middle schools. Data from classroom observations, teacher interviews, and online student spaces and artifacts provide insight into the technologies of power…
Exploring Children's Thinking with and about Numbers from a Resources-Based Approach
ERIC Educational Resources Information Center
Scheuer, Nora; Santamaria, Flavia Irene; Echenique, Mónica Haydée
2017-01-01
The aim of this study is to achieve a deeper understanding of the repertoire of cognitive resources children can display in the process of learning numbers. Forty-two children attending Age 4 Kindergarten Class or Year-One in Argentina were individually interviewed, based on a semi-structured script requiring them to represent definite and…
Calvo, Esteban; Madero-Cabib, Ignacio; Staudinger, Ursula M
2017-06-06
A destandardization of labor-force patterns revolving around retirement has been observed in recent literature. It is unclear, however, to which degree and of which kind. This study looked at sequences rather than individual statuses or transitions and argued that differentiating older Americans' retirement sequences by type, order, and timing and considering gender, class, and race differences yields a less destandardized picture. Sequence analysis was employed to analyze panel data from the Health and Retirement Study (HRS) for 7,881 individuals observed 6 consecutive times between ages 60-61 and 70-71. As expected, types of retirement sequences were identified that cannot be subsumed under the conventional model of complete retirement from full-time employment around age 65. However, these retirement sequences were not entirely destandardized, as some irreversibility and age-grading persisted. Further, the degree of destandardization varied along gender, class, and race. Unconventional sequences were archetypal for middle-level educated individuals and Blacks. Also, sequences for women and individuals with lower education showed more unemployment and part-time jobs, and less age-grading. A sequence-analytic approach that models group differences uncovers misjudgments about the degree of destandardization of retirement sequences. When a continuous process is represented as individual transitions, the overall pattern of retirement sequences gets lost and appears destandardized. These patterns get further complicated by differences in social structures by gender, class, and race in ways that seem to reproduce advantages that men, more highly educated individuals, and Whites enjoy in numerous areas over the life course. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Habitat selection by breeding waterbirds at ponds with size-structured fish populations
NASA Astrophysics Data System (ADS)
Kloskowski, Janusz; Nieoczym, Marek; Polak, Marcin; Pitucha, Piotr
2010-07-01
Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size structure of common carp ( Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural system of monocultured ponds, where three fish age classes were separately stocked. Fish age corresponded to a distinct fish size gradient. Fish age and total biomass, macroinvertebrate and amphibian abundance, and emergent vegetation best explained the differences in bird density between ponds. Abundance of animal prey other than fish (aquatic macroinvertebrates and larval amphibians) decreased with increasing carp age in the ponds. Densities of ducks and smaller grebes were strongly negatively associated with fish age/size gradient. The largest of the grebes, the piscivorous great crested grebe ( Podiceps cristatus), was the only species that preferred ponds with medium-sized fish and was positively associated with total fish biomass. Habitat selection by bitterns and most rallids was instead strongly influenced by the relative amount of emergent vegetation cover in the ponds. Our results show that fish size structure may be an important cue for breeding habitat choice and a factor affording an opportunity for niche diversification in avian communities.
Monotone Approximation for a Nonlinear Size and Class Age Structured Epidemic Model
2006-02-22
information if it does not display a currently valid OMB control number. 1. REPORT DATE 22 FEB 2006 2. REPORT TYPE 3. DATES COVERED 00-00-2006 to 00...follows from standard results, given the fact that they are all linear problems with local boundary conditions for Sinko-Streifer type systems. We...model, J. Franklin Inst., 297 (1974), 325-333. [14] K. E. Howard, A size and maturity structured model of cell dwarfism exhibiting chaotic be- havior
Smoking in Scottish youths: personal income, parental social class and the cost of smoking
West, Patrick; Sweeting, Helen; Young, Robert
2007-01-01
Objective To examine the relation of young people's personal income and parental social class with smoking from early to mid adolescence. Design Longitudinal, school based, study of a cohort of 2586 eleven year‐olds followed up at ages 13 and 15. Setting West of Scotland. Participants 93% baseline participation, reducing to 79% at age 15. Main outcome measures Ever smoked (age 11), current and daily smoking (ages 13 and 15) and the proportion of income spent on tobacco (13 and 15) based on recommended retail prices of usual brands. Results Strong independent effects of parental social class and personal income were found at 11 years, both reducing with age. The higher incomes of lower class participants attenuated the social class effect on smoking at ages 11 and 13, but not at 15. Analysis within class groups showed variation in the effect of income on smoking, being strongest among higher class youths and weak or non‐existent among lower class youths. This was despite the fact that the proportion of weekly income apparently spent on tobacco was greater among lower class youths. Conclusions The results confirm the importance of personal income and parental social class for youth smoking, but they also show that personal income matters more for those from higher class backgrounds. This suggests both that lower class youths have greater access to tobacco from family and friends and to cheaper sources of cigarettes from illegal sources. This complicates the relation between fiscal policies and smoking and might have the unintended consequence of increasing class differentials in youth smoking rather than the reverse. PMID:17897992
Barriers to oral health care amongst different social classes in India.
Garcha, V; Shetiya, S H; Kakodkar, P
2010-09-01
To investigate and compare the influence of social and cultural factors as access barriers to oral health care amongst people from various social classes. A cross sectional survey in Pimpri, was conducted using a pilot tested 15 item-structured, close-ended and self-administered questionnaire. Two hundred and fifty people aged 35-45 years (50 participants each in five social classes as per British Registrar's General classification of occupation) were selected. The chi-square test was applied to check statistical differences between social classes at 5% level of significance. Overall, it was observed that irrespective of the social class difference 88% participants wished to seek only expert/professional advice for the dental treatment. Unavailability of services on Sunday (63%), going to dentist only when in pain (57%), trying self care or home remedy (54%), inadequate government policies (50%), budgetary constraints (40%) were among the major access barriers. Statistically significant difference in the access barriers among the social classes were found related to: Inadequate government policies, budgetary constraints, appointment schedules, far-off located clinics, myths and fear about dental treatment. Social and cultural factors act as access barriers to oral health care and social class differences have a significant influence on the access barriers.
[Socioeconomic inequalities and age and gender differences in cardiovascular risk factors].
López-González, Ángel A; Bennasar-Veny, Miquel; Tauler, Pedro; Aguilo, Antoni; Tomàs-Salvà, Matias; Yáñez, Aina
2015-01-01
To describe the cardiovascular risk factors in a working population in the Balearic Islands and to examine whether differences by social class vary according to age and gender. A cross-sectional study was carried out in a sample of active workers aged 20-65 years in the Balearic Islands. The participants were included in the study during their annual work health assessment in 2011. The following variables were collected: occupation, social class, age, gender, height, weight, smoking, blood pressure, lipid profile, and glucose levels. Cardiovascular risk was calculated using two different equations (Framingham and REGICOR). Differences by social class were observed for most cardiovascular risk factors. The pattern of these differences differed depending on age group and gender. Differences in obesity by social class increased with age in women but decreased in men. More differences in hypertension by social class were found among women than among men, with differences increasing with age in both genders. Significant differences by social class were found among women in lipid profile, and these differences increased with age, mainly for low levels of high-density lipoprotein-cholesterol. Inequalities in cardiovascular risk factors by social class were higher among women than among men. Some cardiovascular risk factors such as smoking and obesity showed significant inequalities from a very early age. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.
Dong, Aishu; Chen, Sisi; Zhu, Lianlian; Shi, Lingmin; Cai, Yueli; Zeng, Jingni; Guo, Wenjian
2017-08-01
Chronic heart failure (CHF), a major public health problem worldwide, seriously limits health-related quality of life (HRQOL). How to evaluate HRQOL in older patients with CHF remains a problem. To evaluate the reliability and validity of the Chinese version of the Medical Outcomes Study Short Form version 2 (SF-36v2) in CHF patients. From September 2012 to June 2014, we assessed QOL using the SF-36v2 in 171 aging participants with CHF in four cardiology departments. Convergent and discriminant validity, factorial validity, sensitivity among different NYHA classes and between different age groups, and reliability were determined using standard measurement methods. A total of 150 participants completed a structured questionnaire including general information and the Chinese SF-36v2; 132 questionnaires were considered valid, while 21 patients refused to take part. 25 of the 50 participants invited to complete the 2-week test-retest questionnaires returned completed questionnaires. The internal consistency reliability (Cronbach's α) of the total SF-36v2 was 0.92 (range 0.74-0.93). All hypothesized item-subscale correlations showed satisfactory convergent and discriminant validity. Sensitivity was measured in different NYHA classes and age groups. Comparison of different NYHA classes showed statistical significance, but there was no significant difference between age groups. We confirmed the SF-36v2 as a valid instrument for evaluating HRQOL Chinese CHF patients. Both reliability and validity were strongly satisfactory, but there was divergence in understanding subscales such as "social functioning" because of differing cultural background. The reliability, validity, and sensitivity of SF-36v2 in aging patients with CHF were acceptable.
The influence of a yoga exercise program for young adults with intellectual disabilities.
Hawkins, Brent L; Stegall, Joanna B; Weber, Madalyn F; Ryan, Joseph B
2012-07-01
Individuals with intellectual disabilities (ID) have an increased risk of obesity and are significantly less likely to engage in physical activity compared to their nondisabled peers. A growing body of research supports the physical and mental health benefits of yoga. While the benefits of yoga have been studied across a host of populations with varying ages and physical disabilities, no studies could be identified investigating the benefits of yoga for young adults with ID. This study investigated the impact of participating in yoga classes on the amount of exercise behavior and perception of physical exertion when compared to non-structured exercise sessions between two young adults with ID in a post-secondary education setting. A single subject multiple baseline research design was implemented across two young adults with mild ID to determine the effects of a yoga exercise class on frequency of exercise behavior and perception of physical exertion when compared to non-structured exercise sessions. Partial interval recording, the Eston-Parfitt curvilinear rating of perceived exertion scale, and the physical activity enjoyment scale were implemented to collect data on dependent variables and consumer satisfaction during each non-structured exercise session and each yoga class. indicated that percentage of exercise behavior and perceived exertion levels during yoga group exercise sharply increased with large effect sizes when compared to non-structured exercise sessions.
A pilot yoga physical education curriculum to promote positive body image.
Cox, Anne E; Ullrich-French, Sarah; Howe, Holly S; Cole, Amy N
2017-12-01
We examined the effects of a pilot yoga-based physical education (PE) curriculum by testing for change in trait body surveillance, physical self-worth, and body appreciation. Further, we examined the relationships among change in body image variables and the role of state mindfulness in predicting state body surveillance during classes. Adolescents participated in 12 weeks of yoga-based (n=20; M age =16.45, 90% female) or traditional (n=23;M age =14.52, 57% female) PE. Results showed significant (p=.004), moderate decreases in trait body surveillance and minimal nonsignificant (p=.11) increases in physical self-worth. Change in trait body surveillance was inversely related to change in physical self-worth and body appreciation in yoga participants. Multi-level modeling analyses revealed that more mindful students also surveyed their body less during class. Intentionally structured yoga participation may support positive body image among adolescents. Copyright © 2017 Elsevier Ltd. All rights reserved.
Effect of a fish stock's demographic structure on offspring survival and sensitivity to climate
Stige, Leif Christian; Yaragina, Natalia A.; Langangen, Øystein; Bogstad, Bjarte; Stenseth, Nils Chr.; Ottersen, Geir
2017-01-01
Commercial fishing generally removes large and old individuals from fish stocks, reducing mean age and age diversity among spawners. It is feared that these demographic changes lead to lower and more variable recruitment to the stocks. A key proposed pathway is that juvenation and reduced size distribution causes reduced ranges in spawning period, spawning location, and egg buoyancy; this is proposed to lead to reduced spatial distribution of fish eggs and larvae, more homogeneous ambient environmental conditions within each year-class, and reduced buffering against negative environmental influences. However, few, if any, studies have confirmed a causal link from spawning stock demographic structure through egg and larval distribution to year class strength at recruitment. We here show that high mean age and size in the spawning stock of Barents Sea cod (Gadus morhua) is positively associated with high abundance and wide spatiotemporal distribution of cod eggs. We find, however, no support for the hypothesis that a wide egg distribution leads to higher recruitment or a weaker recruitment–temperature correlation. These results are based on statistical analyses of a spatially resolved data set on cod eggs covering a period (1959−1993) with large changes in biomass and demographic structure of spawners. The analyses also account for significant effects of spawning stock biomass and a liver condition index on egg abundance and distribution. Our results suggest that the buffering effect of a geographically wide distribution of eggs and larvae on fish recruitment may be insignificant compared with other impacts. PMID:28115694
Koppenol-Gonzalez, Gabriela V; Bouwmeester, Samantha; Vermunt, Jeroen K
2014-10-01
In studies on the development of cognitive processes, children are often grouped based on their ages before analyzing the data. After the analysis, the differences between age groups are interpreted as developmental differences. We argue that this approach is problematic because the variance in cognitive performance within an age group is considered to be measurement error. However, if a part of this variance is systematic, it can provide very useful information about the cognitive processes used by some children of a certain age but not others. In the current study, we presented 210 children aged 5 to 12 years with serial order short-term memory tasks. First we analyze our data according to the approach using age groups, and then we apply latent class analysis to form latent classes of children based on their performance instead of their ages. We display the results of the age groups and the latent classes in terms of serial position curves, and we discuss the differences in results. Our findings show that there are considerable differences in performance between the age groups and the latent classes. We interpret our findings as indicating that the latent class analysis yielded a much more meaningful way of grouping children in terms of cognitive processes than the a priori grouping of children based on their ages. Copyright © 2014 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Yi, K.; Park, C.; Ryu, S.; Lee, K.; Yi, M.; Kim, C.; Park, G.; Kim, R.; Son, Y.
2011-12-01
Soil carbon (C) stocks of Pinus densiflora forests in Korea were estimated using a generic forest soil C dynamics model based on the process of dead organic matter input and decomposition. Annual input of dead organic matter to the soil was determined by stand biomass and turnover rates of tree components (stem, branch, twig, foliage, coarse root, and fine root). The model was designed to have a simplified structure consisting of three dead organic matter C (DOC) pools (aboveground woody debris (AWD), belowground woody debris (BWD), and litter (LTR) pool) and one soil organic C (SOC) pool. C flows in the model were regulated by six turnover rates of stem, branch, twig, foliage, coarse root, and fine root, and four decay rates of AWD, BWD, LTR, and SOC. To simulate the soil C stocks of P. densiflora forests, statistical data of forest land area (1,339,791 ha) and growing stock (191,896,089 m3) sorted by region (nine provinces and seven metropolitan cities) and stand age class (11 to 20- (II), 21 to 30- (III), 31 to 40- (IV), 41 to 50- (V), and 51 to 60-year-old (VI)) were used. The growing stock of each stand age class was calculated for every region and representable site index was also determined by consulting the yield table. Other model parameters related to the stand biomass, annual input of dead organic matter and decomposition were estimated from previous studies conducted on P. densiflora forests in Korea, which were also applied for model validation. As a result of simulation, total soil C stock of P. densiflora forests were estimated as 53.9 MtC and soil C stocks per unit area ranged from 28.71 to 47.81 tC ha-1 within the soil depth of 30 cm. Also, soil C stocks in the P. densiflora forests of age class II, III, IV, V, and VI were 16,780,818, 21,450,812, 12,677,872, 2,366,939, and 578,623 tC, respectively, and highly related to the distribution of age classes. Soil C stocks per unit area initially decreased with stand age class and started to increase after the stand age class of V. Regional soil C stocks ranged from 9,805 to 15,595,802 tC, and were generally proportional to the forest land area. Our results suggest an approach to estimate soil C stock on a national scale by using a computer model and manipulating the existing statistical data.
ERIC Educational Resources Information Center
Burger, Lisa K.; Miller, Peggy J.
1999-01-01
Investigated personal storytelling among young working-class and middle-class children, observing them at home at age 2; age 6 and 3; and under-one year. Analysis of generic properties, narrative content, and emotion talk revealed a complex configuration of similarities and differences. Differentiation between working-class and middle-class…
Learning science in small multi-age groups: the role of age composition
NASA Astrophysics Data System (ADS)
Kallery, Maria; Loupidou, Thomais
2016-06-01
The present study examines how the overall cognitive achievements in science of the younger children in a class where the students work in small multi-age groups are influenced by the number of older children in the groups. The context of the study was early-years education. The study has two parts: The first part involved classes attended by pre-primary children aged 4-6. The second part included one primary class attended by students aged 6-8 in addition to the pre-primary classes. Students were involved in inquiry-based science activities. Two sources of data were used: Lesson recordings and children's assessments. The data from both sources were separately analyzed and the findings plotted. The resulting graphs indicate a linear relationship between the overall performance of the younger children in a class and the number of older ones participating in the groups in each class. It seems that the age composition of the groups can significantly affect the overall cognitive achievements of the younger children and preferentially determines the time within which this factor reaches its maximum value. The findings can be utilized in deciding the age composition of small groups in a class with the aim of facilitating the younger children's learning in science.
Hossack, B.R.; Corn, P.S.; Fagre, D.B.
2006-01-01
Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphus montanus Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams in northwestern Montana to determine the effects of wildfire on A. montanus. All streams were initially sampled in 2001, 2 years before four of them burned in a large wildfire, and were resampled during the 2 years following the fire. Counts of tadpoles were similar in the two groups of streams before the fire. After the fire, tadpoles were almost twice as abundant in unburned streams than in burned streams. The fire seemed to have the greatest negative effect on abundance of age-1 tadpoles, which was reflected in the greater variation in same-stream age-class structure compared with those in unburned streams. Despite the apparent effect on tadpoles, we do not expect the wildfire to be an extirpation threat to populations in the streams that we sampled. Studies spanning a chronosequence of fires, as well as in other areas, are needed to assess the effects of fires on streams with A. montanus and to determine the severity and persistence of these effects.
Blake R. Hossack; Paul Stephen Corn; Daniel B. Fagre
2006-01-01
Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphus montanus Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams in northwestern...
ERIC Educational Resources Information Center
Stirrup, Julie; Evans, John; Davies, Brian
2017-01-01
Drawing on the theoretical work of the British sociologist Basil Bernstein, this paper documents how learning is structured and organised through play in three Early Years Education (EYE) settings catering for children aged three to five in England, UK. Its data address current issues raised within EYE research relating to "quality and high…
Wolfgang G. Glasser; Timothy G. Rials; Stephen S. Kelly; Vipul Dave
1998-01-01
Wood and dietary fiber products all belong to a class of biomolecular composites that are rich in cellulose and lignin. The interaction between cellulose and lignin determines such properties as mechanical strength (wood); creep, durability, and aging; cellulose purity (pulp); and digestibility (nutrients). The understanding of the interaction between cellulose and...
Deferred rotation harvests in central Appalachia: 20- and 25-year results
Melissa Thomas-Van Gundy; Thomas M. Schuler
2008-01-01
In deferment harvest, two distinct age classes are created and the residual trees remain after establishment of the second cohort. The 20- or 25-year preliminary results from four deferment areas are described. For each area, volume and growth in the residual trees and new cohort, and structure and composition of the new cohort are presented. We also address whether...
Brin, Ilana; Camasuvi, Semin; Dali, Nasser; Aizenbud, Dror
2006-12-01
The eruptive positions of the second molars in Class I and Class II malocclusions were studied. Pretreatment records of 221 patients with a mean age of 11.3 years were evaluated. About 19% of them had skeletal Class I, 31% had skeletal maxillary Class II, and 50% had skeletal mandibular Class II malocclusions. The mean values of the dental and chronologic ages of the subjects were similar. The eruptive positions in relation to a reference line, the developmental stages of the patients' second molars and dental ages were recorded from the panoramic roentgenograms. The distribution of the various developmental stages in each malocclusion group was similar, and no association between skeletal malocclusion and dental developmental stage of the second molars was encountered. The eruptive position of the maxillary second molars was more occlusal only in the oldest maxillary Class II group, above 12 years of age (P = .02). These results support, in part, previous reports suggesting that the maxillary second molars may erupt earlier in patients with skeletal maxillary Class II malocclusions.
Subjective Wellbeing, Objective Wellbeing and Inequality in Australia
Western, Mark
2016-01-01
In recent years policy makers and social scientists have devoted considerable attention to wellbeing, a concept that refers to people’s capacity to live healthy, creative and fulfilling lives. Two conceptual approaches dominate wellbeing research. The objective approach examines the objective components of a good life. The subjective approach examines people’s subjective evaluations of their lives. In the objective approach how subjective wellbeing relates to objective wellbeing is not a relevant research question. The subjective approach does investigate how objective wellbeing relates to subjective wellbeing, but has focused primarily on one objective wellbeing indicator, income, rather than the comprehensive indicator set implied by the objective approach. This paper attempts to contribute by examining relationships between a comprehensive set of objective wellbeing measures and subjective wellbeing, and by linking wellbeing research to inequality research by also investigating how subjective and objective wellbeing relate to class, gender, age and ethnicity. We use three waves of a representative state-level household panel study from Queensland, Australia, undertaken from 2008 to 2010, to investigate how objective measures of wellbeing are socially distributed by gender, class, age, and ethnicity. We also examine relationships between objective wellbeing and overall life satisfaction, providing one of the first longitudinal analyses linking objective wellbeing with subjective evaluations. Objective aspects of wellbeing are unequally distributed by gender, age, class and ethnicity and are strongly associated with life satisfaction. Moreover, associations between gender, ethnicity, class and life satisfaction persist after controlling for objective wellbeing, suggesting that mechanisms in addition to objective wellbeing link structural dimensions of inequality to life satisfaction. PMID:27695042
Subjective Wellbeing, Objective Wellbeing and Inequality in Australia.
Western, Mark; Tomaszewski, Wojtek
2016-01-01
In recent years policy makers and social scientists have devoted considerable attention to wellbeing, a concept that refers to people's capacity to live healthy, creative and fulfilling lives. Two conceptual approaches dominate wellbeing research. The objective approach examines the objective components of a good life. The subjective approach examines people's subjective evaluations of their lives. In the objective approach how subjective wellbeing relates to objective wellbeing is not a relevant research question. The subjective approach does investigate how objective wellbeing relates to subjective wellbeing, but has focused primarily on one objective wellbeing indicator, income, rather than the comprehensive indicator set implied by the objective approach. This paper attempts to contribute by examining relationships between a comprehensive set of objective wellbeing measures and subjective wellbeing, and by linking wellbeing research to inequality research by also investigating how subjective and objective wellbeing relate to class, gender, age and ethnicity. We use three waves of a representative state-level household panel study from Queensland, Australia, undertaken from 2008 to 2010, to investigate how objective measures of wellbeing are socially distributed by gender, class, age, and ethnicity. We also examine relationships between objective wellbeing and overall life satisfaction, providing one of the first longitudinal analyses linking objective wellbeing with subjective evaluations. Objective aspects of wellbeing are unequally distributed by gender, age, class and ethnicity and are strongly associated with life satisfaction. Moreover, associations between gender, ethnicity, class and life satisfaction persist after controlling for objective wellbeing, suggesting that mechanisms in addition to objective wellbeing link structural dimensions of inequality to life satisfaction.
The Effect of Mixed-Age Classes in Sweden
ERIC Educational Resources Information Center
Lindstrom, Elly-Ann; Lindahl, Erica
2011-01-01
Mixed-aged (MA) classes are a common phenomenon around the world. In Sweden, these types of classes increased rapidly during the 1980s and 1990s, despite the fact that existing empirical support for MA classes is weak. In this paper, the effect of attending an MA class during grades 4-6 on students' cognitive skills is estimated. Using a unique…
Age-specific productivity and nest site characteristics of Cooper's hawks (Accipiter cooperii)
Moore, K.R.; Henny, C.J.
1984-01-01
Nesting Cooper's Hawks (Accipiter cooperii) were studied in northeastern Oregon. Second-year (SY) males did not breed, but 22 percent of the breeding females were SY's. Mean clutch size (P = 0.012) and mean number of young fledged per pair that laid eggs (P < 0.10) were lower for SY females than for adult (after second year [ASY}) females; however, an equal percentage of the eggs (excluding a collected sample egg) yielded fledged young for each age class. Stepwise discriminant analysis suggested differences in structural characteristics of the nest site habitat for ASY and SY females, i.e., SY female nest sites were associated with younger successional stages than ASY female nest sites. Nests of both age groups were built in trees with high crown volume, but ASY females utilized mistletoe (Arceuthobium sp.) for nest structures more frequently (P < 0.01) than SY females.
Armstrong, D; Strogatz, D; Barnett, E; Wang, R
2003-01-01
Study objective: Occupational structure represents the unequal geographical distribution of more desirable jobs among communities (for example, white collar jobs). This study examines joint effects of social class, race, and county occupational structure on coronary mortality rates for men, ages 35–64 years, 1988–92, in upstate New York. Design: Upstate New York's 57 counties were classified into three occupational structure categories; counties with the lowest percentages of the labour force in managerial, professional, and technical occupations were classified in category I, counties with the highest percentages were in category III. Age adjusted coronary heart disease (CHD) mortality rates, 35–64 years, (from vital statistics and census data) were calculated for each occupational structure category. Main results: An inverse association between CHD mortality and occupational structure was observed among blue collar and white collar workers, among black men and white men, with the lowest CHD mortality observed among white collar, white men in category III (135/100 000). About two times higher mortality was observed among blue collar than white collar workers. Among blue collar workers, mortality was 1.3–1.8 times higher among black compared with white workers, and the highest rates were observed among black, blue collar workers (689/100 000). Also, high residential race segregation was shown in all areas. Conclusions: Results suggest the importance of community conditions in coronary health of local populations; however, differential impact on subpopulations was shown. Blue collar and black workers may especially lack economic and other resources to use available community services and/or may experience worse working and living conditions compared with white collar and white workers in the same communities. PMID:12700223
Environmental factors and the age at onset in first episode psychosis.
O'Donoghue, Brian; Lyne, John; Madigan, Kevin; Lane, Abbie; Turner, Niall; O'Callaghan, Eadbhard; Clarke, Mary
2015-10-01
Factors that influence the age at onset in psychotic disorders could provide valuable insights into precipitating or causative factors of the disorder. Despite being established risk factors, it is not yet known whether migration status, place of birth, social class at birth and season of birth influence the age at onset of psychotic disorders. This study aimed to determine whether these environmental factors, in addition to cannabis abuse and obstetric complications, influence the age at onset. Additionally, we investigated whether environmental factors could have a cumulative effect on the age at onset. Data was obtained from two first episode of psychosis (FEP) cohort studies. Diagnosis was established using the Structured Clinical Interview for DSM IV diagnoses. The age at onset was determined for 555 individuals with a FEP and the median age at onset was 27.3years. Individuals with a history of cannabis abuse had an earlier age at onset by nearly six years. There was a trend for a history of obstetric complications to be associated with a younger age at onset by 2.7years and this was significant in the subgroup with a family history of psychosis. Social class at birth, migration status, place of birth and season of birth were not associated with the age at onset. Exposure to a higher number of environmental factors was associated with an earlier age at onset. Cannabis and obstetric complications are associated with an earlier age at onset and there appears to be a cumulative effect of exposure to multiple environmental factors. Copyright © 2015 Elsevier B.V. All rights reserved.
Mixed-Age Grouping in Nongraded Primary Classes.
ERIC Educational Resources Information Center
Pasemko, Judy Guthrie
This study examined teachers' and parents' perceptions of pedagogical successes in, and problems with, the implementation of mixed-age classes in primary education. Questionnaires were completed by 44 teachers in 2 British Columbia school districts, and by 41 parents of children in mixed-age classes in those districts. Some of the teachers were…
A 2-d classification of diseases based on age-specific death rates
NASA Astrophysics Data System (ADS)
Richmond, Peter; Roehner, Bertrand M.
2018-02-01
Age specific mortality curves exhibit an age tc (about 10 years) which plays a crucial role in that the mortality curve decreases hyperbolically in the age interval A before tc and increases exponentially in the interval B following tc. For those familiar with reliability theory, region A is called the "burn in" phase and B is the "wear out" phase. Using the exponents of the hyperbolic and exponential phases, we introduce a new 2 dimensional map of diseases. This permits the classification of diseases into three broad classes: AS1, AS2 and S. Class AS1 includes all diseases arising from congenital malformations which dominate infant and child mortality; class AS2 includes degenerative diseases such as dementia and Alzheimer's which dominate old age mortality. In class S, which includes most infectious and metabolic diseases, the exponents from both aging phases contribute to positions on the map. Cancer is one of these mixed cases but is closer to class AS2 than AS1. A second line classification is needed to resolve S cases and to this end we introduce a 3rd dimension, namely (calendar) time. Using historical data we show that in their response to treatment (particularly vaccination), S diseases fall into three sub-classes. (i) Class E diseases (e.g. measles or meningococcal disease) which have been almost eliminated at all ages (ii) class C diseases (e.g. tuberculosis) which can be cured but whose cure becomes less effective at old age. (iii) Class U diseases for which radical cures are still unknown. Regarding the future, the fact that the wear-out process of numerous diseases already starts around the age of 25 means that a major extension of the human lifespan beyond 120 certainly also requires to uncover the secret of the "elixir of eternal youth" which has driven timeless human efforts and still seems unlikely in the foreseeable future.
González, Antonio; Faílde Garrido, José María; Rodríguez Castro, Yolanda; Carrera Rodríguez, María Victoria
2015-09-14
The aim of this study was to assess the relationships between class-related anxiety with perceived control, teacher-reported behavioral engagement, behavioral disaffection, and academic performance. Participants were 355 compulsory secondary students (9th and 10th grades; Mean age = 15.2 years; SD = 1.8 years). Structural equation models revealed performance was predicted by perceived control, anxiety, disaffection, and engagement. Perceived control predicted anxiety, disaffection, and engagement. Anxiety predicted disaffection and engagement, and partially mediated the effects from control on disaffection (β = -.277, p < .005; CI = -.378, -.197) and engagement (β = .170, p < .002; CI = .103 .258). The negative association between anxiety and performance was mediated by engagement and disaffection (β = -.295, p < .002; CI = -.439, -.182). Anxiety, engagement, and disaffection mediated the effects of control on performance (β = .352, p < .003; CI = .279, .440). The implications of these results are discussed in the light of current theory and educational interventions.
Leinonen, Taina; Viikari-Juntura, Eira; Husgafvel-Pursiainen, Kirsti; Solovieva, Svetlana
2018-01-01
Objectives We aimed to provide previously unestablished information on population-based differences in cause-specific sickness absence trends between occupational classes and further between four large industrial sectors within the different occupational classes while controlling for other socioeconomic factors and employment patterns. We focused on the period 2005–2013, during which the labour market underwent large economic and structural changes in many countries. Design Register-based panel data study. Setting Large representative datasets on Finnish wage earners aged 25–59 years. Outcome measure Annual risk of sickness absence (>10 working days) based on repeated logistic regression. Results Between 2005 and 2013, the proportion of employees with sickness absence decreased. Occupational class differences in sickness absence trends varied by disease group. Overall, the decrease in absences was smallest among lower non-manual employees. Sickness absence levels were highest in the health and social work sector and in the manufacturing sector within the non-manual and manual classes, respectively. Absences due to musculoskeletal diseases decreased temporarily during the peak of the economic recession in 2009, particularly in the manufacturing sector within the manual class. The decrease in absences due to musculoskeletal diseases was smallest in the trade sector within the lower occupational classes. Overall, education, income and employment patterns partly explained the differences in the absence levels, but not in the trends. Conclusions We found a complex interplay between the associations of occupational class and industrial sector with sickness absence trends. During the economic recession, absences due to musculoskeletal diseases decreased temporarily in a segment of wage earners who were known to have been hit hard by the recession. However, the trend differences were not explained by the measured structural changes in the characteristics of the study population. Both occupational class and industrial sector should be taken into account when tackling problems of work disability. PMID:29627810
Stand structure and dynamics of sand pine differ between the Florida panhandle and peninsula
Drewa, P.B.; Platt, W.J.; Kwit, C.; Doyle, T.W.
2008-01-01
Size and age structures of stand populations of numerous tree species exhibit uneven or reverse J-distributions that can persist after non-catastrophic disturbance, especially windstorms. Among disjunct populations of conspecific trees, alternative distributions are also possible and may be attributed to more localized variation in disturbance. Regional differences in structure and demography among disjunct populations of sand pine (Pinus clausa (Chapm. ex Engelm.) Vasey ex Sarg.) in the Florida panhandle and peninsula may result from variation in hurricane regimes associated with each of these populations. We measured size, age, and growth rates of trees from panhandle and peninsula populations and then compiled size and age class distributions. We also characterized hurricanes in both regions over the past century. Size and age structures of panhandle populations were unevenly distributed and exhibited continuous recruitment; peninsula populations were evenly sized and aged and exhibited only periodic recruitment. Since hurricane regimes were similar between regions, historical fire regimes may have been responsible for regional differences in structure of sand pine populations. We hypothesize that fires were locally nonexistent in coastal panhandle populations, while periodic high intensity fires occurred in peninsula populations over the past century. Such differences in local fire regimes could have resulted in the absence of hurricane effects in the peninsula. Increased intensity of hurricanes in the panhandle and current fire suppression patterns in the peninsula may shift characteristics of sand pine stands in both regions. ?? 2007 Springer Science+Business Media B.V.
Microscopic origin of resistance drift in the amorphous state of the phase-change compound GeTe
NASA Astrophysics Data System (ADS)
Gabardi, S.; Caravati, S.; Sosso, G. C.; Behler, J.; Bernasconi, M.
2015-08-01
Aging is a common feature of the glassy state. In the case of phase-change chalcogenide alloys the aging of the amorphous state is responsible for an increase of the electrical resistance with time. This phenomenon called drift is detrimental in the application of these materials in phase-change nonvolatile memories, which are emerging as promising candidates for storage class memories. By means of combined molecular dynamics and electronic structure calculations based on density functional theory, we have unraveled the atomistic origin of the resistance drift in the prototypical phase-change compound GeTe. The drift results from a widening of the band gap and a reduction of Urbach tails due to structural relaxations leading to the removal of chains of Ge-Ge homopolar bonds. The same structural features are actually responsible for the high mobility above the glass transition which boosts the crystallization speed exploited in the device.
Frappart, Sören; Raijmakers, Maartje; Frède, Valérie
2014-04-01
Children's understanding of universal gravitation starts at an early age but changes until adulthood, which makes it an interesting topic for studying the development and structure of knowledge. Children's understanding of gravitation was tested for a variety of contexts and across a wide age range (5-18 years, N=144). We analyzed children's predictions and justifications for the trajectory of a stone dropped on the earth, on the moon, in a spaceship orbiting the earth, on a planet with air, on a planet with no air, and in a lift (i.e., an elevator) in free fall. Results showed that performances were related to the context and to the children's age. U-shaped developmental curves were identified for predictions for three contexts. These curves could be explained by analyzing the structure of the children's knowledge using latent class analysis. We identified three coherent patterns of predictions that were related to specific justifications. With age, children produced more scientific predictions. Children's cognitive structures, as reflected in their predictions of dropped stone trajectories, seem to be coherently built given that there were only a limited number of prediction patterns. Even by Grade 12, students had not achieved a scientific understanding of universal gravitation. Copyright © 2013 Elsevier Inc. All rights reserved.
Torok, Michelle; Darke, Shane; Shand, Fiona; Kaye, Sharlene
2016-09-01
Violence is a major burden of harm among injecting drug users (IDU), however, the liability to violent offending is not well understood. The current study aimed to better understand differences in the liability to violence by determining whether IDU could be disaggregated into distinct violent offending classes, and determining the correlates of class membership. A total of 300 IDU from Sydney, Australia were administered a structured interview examining the prevalence and severity of drug use and violent offending histories, as well as early life risk factors (maltreatment, childhood mental disorder, trait personality). IDU were disaggregated into four distinct latent classes, comprising a non-violent class (24%), an adolescent-onset persistent class (33%), an adult-onset transient class (24%) and an early-onset, chronic class (19%). Pairwise and group comparisons of classes on predispositional and substance use risks showed that the EARLY class had the poorest psychosocial risk profile, while the NON class had the most favourable. Multinomial logistic regression revealed that higher trait impulsivity and aggression scores, having a history of conduct disorder, frequent childhood abuse, and more problematic alcohol use, were independently associated with more temporally stable and severe violent offending. The model explained 67% of variance in class membership (χ(2)=207.7, df=51, p<0.001). IDU can be meaningfully disaggregated into distinct violent offending classes using developmental criteria. The age of onset of violence was indicative of class membership insomuch as that the extent of early life risk exposure was differentially associated with greater long-term liability to violence and drug use. Copyright © 2016 Elsevier Ltd. All rights reserved.
Johal, Ama; Chaggar, Amrit; Zou, Li Fong
2018-03-01
The present study used the optical surface laser scanning technique to compare the facial features of patients aged 8-18 years presenting with Class I and Class III incisor relationship in a case-control design. Subjects with a Class III incisor relationship, aged 8-18 years, were age and gender matched with Class I control and underwent a 3-dimensional (3-D) optical surface scan of the facial soft tissues. Landmark analysis revealed Class III subjects displayed greater mean dimensions compared to the control group most notably between the ages of 8-10 and 17-18 years in both males and females, in respect of antero-posterior (P = 0.01) and vertical (P = 0.006) facial dimensions. Surface-based analysis, revealed the greatest difference in the lower facial region, followed by the mid-face, whilst the upper face remained fairly consistent. Significant detectable differences were found in the surface facial features of developing Class III subjects.
Treatment outcome of bimaxillary surgery for asymmetric skeletal class II deformity.
Chen, Yun-Fang; Liao, Yu-Fang; Chen, Yin-An; Chen, Yu-Ray
2018-05-04
Facial asymmetry is one of the main concerns in patients with a dentofacial deformity. The aims of the study were to (1) evaluate the changes in facial asymmetry after bimaxillary surgery for asymmetric skeletal class II deformity and (2) compare preoperative and postoperative facial asymmetry of class II patients with normal controls. The facial asymmetry was assessed for 30 adults (21 women and 9 men, mean age: 29.3 years) who consecutively underwent bimaxillary surgery for asymmetric skeletal class II deformity using cone-beam computed tomography before and at least 6 months after surgery. Thirty soft tissue and two dental landmarks were identified on each three-dimensional facial image, and the asymmetry index of each landmark was calculated. Results were compared with those of 30 normal control subjects (21 women and 9 men, mean age: 26.2 years) with skeletal class I structure. Six months after surgery, the asymmetric index of the lower face and total face decreased significantly (17.8 ± 29.4 and 16.6 ± 29.5 mm, respectively, both p < 0.01), whereas the asymmetric index of the middle face increased significantly (1.2 ± 2.2 mm, p < 0.01). Postoperatively, 53% of the class II patients had residual chin asymmetry. The postoperative total face asymmetric index was positively correlated with the preoperative asymmetric index (r = 0.37, p < 0.05). Bimaxillary surgery for patients with asymmetric class II deformity resulted in a significant improvement in lower face asymmetry. However, approximately 50% of the patients still had residual chin asymmetry. The total face postoperative asymmetry was moderately related to the initial severity of asymmetry. These findings could help clinicians better understand orthognathic outcomes on different facial regions for patients with asymmetric class II deformity.
Hildebrandt, Tom; Epstein, Elizabeth E.; Sysko, Robyn; Bux, Donald A.
2017-01-01
Background The type A/B classification model for alcohol use disorders (AUDs) has received considerable empirical support. However, few studies examine the underlying latent structure of this subtyping model, which has been challenged as a dichotomization of a single drinking severity dimension. Type B, relative to type A, alcoholics represent those with early age of onset, greater familial risk, and worse outcomes from alcohol use. Method We examined the latent structure of the type A/B model using categorical, dimensional, and factor mixture models in a mixed gender community treatment-seeking sample of adults with an AUD. Results Factor analytic models identified 2-factors (drinking severity/externalizing psychopathology and internalizing psychopathology) underlying the type A/B indicators. A factor mixture model with 2-dimensions and 3-classes emerged as the best overall fitting model. The classes reflected a type A class and two type B classes (B1 and B2) that differed on the respective level of drinking severity/externalizing pathology and internalizing pathology. Type B1 had a greater prevalence of women and more internalizing pathology and B2 had a greater prevalence of men and more drinking severity/externalizing pathology. The 2-factor, 3-class model also exhibited predictive validity by explaining significant variance in 12-month drinking and drug use outcomes. Conclusions The model identified in the current study may provide a basis for examining different sources of heterogeneity in the course and outcome of AUDs. PMID:28247423
Trask, Amanda E; Bignal, Eric M; McCracken, Davy I; Piertney, Stuart B; Reid, Jane M
2017-09-01
A population's effective size (N e ) is a key parameter that shapes rates of inbreeding and loss of genetic diversity, thereby influencing evolutionary processes and population viability. However, estimating N e , and identifying key demographic mechanisms that underlie the N e to census population size (N) ratio, remains challenging, especially for small populations with overlapping generations and substantial environmental and demographic stochasticity and hence dynamic age-structure. A sophisticated demographic method of estimating N e /N, which uses Fisher's reproductive value to account for dynamic age-structure, has been formulated. However, this method requires detailed individual- and population-level data on sex- and age-specific reproduction and survival, and has rarely been implemented. Here, we use the reproductive value method and detailed demographic data to estimate N e /N for a small and apparently isolated red-billed chough (Pyrrhocorax pyrrhocorax) population of high conservation concern. We additionally calculated two single-sample molecular genetic estimates of N e to corroborate the demographic estimate and examine evidence for unobserved immigration and gene flow. The demographic estimate of N e /N was 0.21, reflecting a high total demographic variance (σ2dg) of 0.71. Females and males made similar overall contributions to σ2dg. However, contributions varied among sex-age classes, with greater contributions from 3 year-old females than males, but greater contributions from ≥5 year-old males than females. The demographic estimate of N e was ~30, suggesting that rates of increase of inbreeding and loss of genetic variation per generation will be relatively high. Molecular genetic estimates of N e computed from linkage disequilibrium and approximate Bayesian computation were approximately 50 and 30, respectively, providing no evidence of substantial unobserved immigration which could bias demographic estimates of N e . Our analyses identify key sex-age classes contributing to demographic variance and thus decreasing N e /N in a small age-structured population inhabiting a variable environment. They thereby demonstrate how assessments of N e can incorporate stochastic sex- and age-specific demography and elucidate key demographic processes affecting a population's evolutionary trajectory and viability. Furthermore, our analyses show that N e for the focal chough population is critically small, implying that management to re-establish genetic connectivity may be required to ensure population viability. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.
Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario
Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.
2006-01-01
Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.
Body Image Disturbance in 1000 Male Appearance and Performance Enhancing Drug Users
Hildebrandt, Tom; Alfano, Lauren; Langenbucher, James W.
2010-01-01
Body image disturbance (BID) among men has only recently become a phenomenon of clinical significance with noted heterogeneity in the behavioral consequences of these disturbances. The degree of heterogeneity among appearance and performance enhancing drug (APED) users is unknown and an empirically derived framework for studying BID is necessary. 1000 APED users were recruited via the Internet and they completed a comprehensive online assessment APED use patterns, motivations, consequences, and BID. Data were evaluated using latent trait, latent class, and factor mixture models. Model results were validated using a range of covariates including cycle characteristics, age, APED history, and APED risk. A 1-Factor, 4-Class model provided the best fit to the data with Class 1 scoring the highest on all measures of BID and Class 4 the lowest on all measures. Class 2 differed in their preference for being lean over muscular and Class 3 preferred adding mass and size. Each class was associated with unique risks, APED history, and training identity. Not all APED users suffer from significant BID and there are unique profiles for those with elevated BID. Future research on male BID should account for this structure in order to better define relevant diagnostic categories and evaluate the clinical significance of BID. PMID:20110092
Harris, Mathew A; Brett, Caroline E; Starr, John M; Deary, Ian J; Johnson, Wendy
2016-01-01
Recent observations that personality traits are related to later-life health and wellbeing have inspired considerable interest in exploring the mechanisms involved. Other factors, such as cognitive ability and education, also show longitudinal influences on health and wellbeing, but it is not yet clear how all these early-life factors together contribute to later-life health and wellbeing. In this preliminary study, we assessed hypothesised relations among these variables across the life course, using structural equation modelling in a sample assessed on dependability (a personality trait related to conscientiousness) in childhood, cognitive ability and social class in childhood and older age, education, and health and subjective wellbeing in older age. Our models indicated that both health and subjective wellbeing in older age were influenced by childhood IQ and social class, via education. Some older-age personality traits mediated the effects of early-life variables, on subjective wellbeing in particular, but childhood dependability did not show significant associations. Our results therefore did not provide evidence that childhood dependability promotes older-age health and wellbeing, but did highlight the importance of other early-life factors, particularly characteristics that contribute to educational attainment. Further, personality in later life may mediate the effects of early-life factors on health and subjective wellbeing. © 2016 The Authors. European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology.
Choi, Young; Kim, Jae-Hyun; Park, Eun-Cheol
2016-01-01
Several previous studies have established the relationship between the effects of socioeconomic status or subjective social strata on life satisfaction. However, no previous study has examined the relationship between social class and life satisfaction in terms of a disparity between subjective and objective social status. To investigate the relationship between differences in subjective and objective social class and life satisfaction. Data from the Korean Longitudinal Study of Aging with 8252 participants aged 45 or older was used. Life satisfaction was measured by the question, "How satisfied are you with your quality of life?" The main independent variable was differences in objective (income and education) and subjective social class, which was classified according to nine categories (ranging from high-high to low-low). This association was investigated by linear mixed model due to two waves data nested within individuals. Lower social class (income, education, subjective social class) was associated with dissatisfaction. The impact of objective and subjective social class on life satisfaction varied according to the level of differences in objective and subjective social class. Namely, an individual's life satisfaction declined as objective social classes decreased at the same level of subjective social class (i.e., HH, MH, LH). In both dimensions of objective social class (education and income), an individual's life satisfaction declined as subjective social class decreased by one level (i.e., HH, HM, HL). Our findings indicated that social supports is needed to improve the life satisfaction among the population aged 45 or more with low social class. The government should place increased focus on policies that encourage not only the life satisfaction of the Korean elderly with low objective social class, but also subjective social class. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Mark A. Rumble; R. Scott Gamo
2011-01-01
Timber management is the most prominent land management activity in the Black Hills National Forest in the northcentral United States. Management units are stands 4-32 ha in size and are described using a hierarchal vegetative description including vegetation type, size class (age), and overstory canopy cover. For the most part, these stands are relatively homogeneous...
Adult Learning and the Teaching of Evaluation: A Study of an Experiential Learning Project.
ERIC Educational Resources Information Center
Preskill, Hallie
The paper describes the development of a course on evaluation in business and industry, offered as part of a Master's program in Human Resource Development. Since the average age of the students was 36, special emphasis was placed on structuring the class to increase relevance to the students' working lives and to ways adults learn best. A brief…
ERIC Educational Resources Information Center
McLean, Monica; Abbas, Andrea; Ashwin, Paul
2015-01-01
This article places itself in conversation with literature about how the experience and outcomes of university education are structured by intersections between social class, ethnicity, gender, age and type of university attended. It addresses undergraduate students' acquisition of sociological knowledge in four diverse university settings. Basil…
Carmel, S; Lazar, A
1998-01-01
The purpose of the study was to compare three groups of Israeli elderly that differ in social class and immigration status on measures of health and psycho-social well-being, and assess the factors which explain their self-rated health (SRH). Based on a random sample of Israeli Jewish elderly (70 +), data were collected from 1138 persons during 1994 by structured home interviews. Social class differences among Israeli veterans were mainly found with regard to psycho-social characteristics. They were less conspicuous in health measures. New immigrants, who had a higher level of education than the veterans, but ranked lower on economic status, reported lower levels of health and psycho-social well-being than the veterans. Self-rated health among the immigrants was mainly explained by objective measures of health, and economic status, while in the higher social class of veterans it was also explained by education and psycho-social variables such as self-esteem and social support. These findings indicate that in contradiction to the convergence hypothesis, social class and immigration status affect health and well-being also in old age. It is suggested that the immigration crisis and factors related to the standard of living and health services in the countries of origin, as well as the lower social and economic status of the immigrants in Israel, outweigh their relative advantage in age and education in influencing their health and well-being. The differences found among the three groups in the factors that explain self-rated health have implications for the use of economic status as a relevant indicator of social class when considering health status among the elderly, and for the interpretation of SRH, as a global measure of health, in different socio-cultural groups.
Lennox, Jemma; Emslie, Carol; Sweeting, Helen; Lyons, Antonia
2018-05-04
Research suggests young women view drinking as a pleasurable aspect of their social lives but that they face challenges in engaging in a traditionally 'masculine' behaviour whilst maintaining a desirable 'femininity'. Social network sites such as Facebook make socialising visible to a wide audience. This paper explores how young people discuss young women's drinking practices, and how young women construct their identities through alcohol consumption and its display on social media. We conducted 21 friendship-based focus groups (both mixed and single sex) with young adults aged 18-29 years and 13 individual interviews with a subset of focus group respondents centred on their Facebook practices. We recruited a purposive sample in Glasgow, Scotland (UK) which included 'middle class' (defined as students and those in professional jobs) and 'working class' respondents (employed in manual/service sector jobs), who participated in a range of venues in the night time economy. Young women's discussions revealed a difficult 'balancing act' between demonstrating an 'up for it' sexy (but not too sexy) femininity through their drinking and appearance, while still retaining control and respectability. This 'balancing act' was particularly precarious for working class women, who appeared to be judged more harshly than middle class women both online and offline. While a gendered double standard around appearance and alcohol consumption is not new, a wider online audience can now observe and comment on how women look and behave. Social structures such as gender and social class remain central to the construction of identity both online and offline. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.
The Effect of ACP₁-ADA₁ Genetic Interaction on Human Life Span.
Lucarini, Nazzareno; Napolioni, Valerio; Magrini, Andrea; Gloria, Fulvia
2012-12-01
Acid phosphatase (ACP₁) is a polymorphic enzyme that catalyzes the conversion of flavin-mononucleotide (FMN) to riboflavin and regulates the cellular concentration of flavin-adenine-dinucleotide (FAD) and, consequently, energy metabolism. Its activity is modulated by adenosine deaminase locus 1 (ADA₁) genotype. The aim of our work is to verify whether individuals with a high proportion of ACP₁ f-isozyme and carrying the ADA₁*2 allele, displaying the highest phosphatase activity, may have a higher life expectancy. Genomic DNA was extracted from the peripheral blood of 569 females and 509 males (18 to 106 years of age) randomly recruited from Central Italy. These samples were subdivided into three sex-specific age groups (the ages of women are in square bracket): Class 1: age <66 [<73]; Class 2: ages 66 to 88 [73 to 91]; Class 3: age >88 [>91]. ACP₁and ADA₁ singlenucleotide polymorphisms (SNPs) were genotyped by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) methods and statistical analyses were performed with SPSS 14.0. The results showed a larger proportion of Class 3 individuals displaying high ACP₁ f-isozyme concentration and carrying the ADA₁*2 allele than those individuals of Class 2 and Class 2 plus Class 1. Thus, we postulate that in Class 3 individuals the high phosphatase activity, resulting from the combined presence of high ACP₁ f-isozyme concentration and the ADA₁*2 allele, lowers the rate of glycolysis that may reduce the amount of metabolic calories and, in turn, activate Sirtuin genes that protect cells against age-related diseases. Copyright © 2013 Wayne State University Press, Detroit, Michigan 48201-1309.
Education of Social Skills among Senior High School Age Students in Physical Education Classes
ERIC Educational Resources Information Center
Akelaitis, Arturas V.; Malinauskas, Romualdas K.
2016-01-01
Research aim was to reveal peculiarities of the education of social skills among senior high school age students in physical education classes. We hypothesized that after the end of the educational experiment the senior high school age students will have more developed social skills in physical education classes. Participants in the study were 51…
Eccentric preformative molt in the spotted Towhee
Fettig, Stephen M.; Hathcock, Charles Dean
2016-11-04
Examination of wing-feather molt often provides information essential for aging birds in the hand (Mulvihill 1993, pyle 1997b, 2008). Correctly aging birds is important for understanding the causal relationships between age-class survival rates and population changes (DeSante et al. 2005). For example, correctly aging birds facilitates understanding of climate effects on reproduction better than merely moni- toring population numbers because reproduction varies widely with annual weather patterns (DeSante and O’grady 2000). Age-class information can also provide a clear measure of habitat quality without confounding effects such as population sources and sinks (Van horne 1983) or misleading habitat-quality information based onmore » relative abundance or population size (pulliam 1988). Changes in bird populations often lag changes in the survival rate of an age class, while environmental changes often affect one age class immediately or after a short lag (Temple and Wiens 1989)« less
Affective, Biological, and Cognitive Predictors of Depressive Symptom Trajectories in Adolescence
Salk, Rachel; Hyde, Janet Shibley; Priess-Groben, Heather A.; Simonson, Jordan L.
2013-01-01
Heterogeneity in the longitudinal course of depressive symptoms was examined using latent growth mixture modeling among a community sample of 382 U.S. youth from ages 11 to 18 (52.1% female). Three latent trajectory classes were identified: Stable Low (51%; displayed low depressive symptoms at all assessments), Increasing (37%; reported low depressive symptoms at age 11, but then significantly higher depressive symptoms than the Stable Low class at ages 13, 15, and 18), and Early High (12%; reported high early depressive symptoms at age 11, followed by symptoms that declined over time yet remained significantly higher than those of the Stable Low class at ages 13, 15, and 18). By age 15, rates of Major Depressive Disorder diagnoses among the Early High (25.0%) and Increasing (20.4%) classes were more than twice that observed among the Stable Low class (8.8%). Affective (negative affectivity), biological (pubertal timing, sex) and cognitive (cognitive style, rumination) factors were examined as predictors of class membership. Results indicated general risk factors for both high-risk trajectories as well as specific risk factors unique to each trajectory. Being female and high infant negative affectivity predicted membership in the Increasing class. Early puberty, high infant negative affectivity for boys, and high rumination for girls predicted membership in the Early High class. Results highlight the importance of examining heterogeneity in depression trajectories in adolescence as well as simultaneously considering risk factors across multiple domains. PMID:24158642
The Impact Of Middle Class Consumption On Democratization In Northeast Asia
2016-03-01
middle-class Koreans. This consumption disparity caused the structurally disadvantaged working-class Koreans to join national protests that ultimately...inequality and a mobility-restraining household registration system. There exists a key political tension around structurally disadvantaged Chinese migrant...lower middle-class Koreans. This consumption disparity caused the structurally disadvantaged working-class Koreans to join national protests that
Zhao, Tian; Villéger, Sébastien; Lek, Sovan; Cucherousset, Julien
2014-01-01
Investigations on the functional niche of organisms have primarily focused on differences among species and tended to neglect the potential effects of intraspecific variability despite the fact that its potential ecological and evolutionary importance is now widely recognized. In this study, we measured the distribution of functional traits in an entire population of largemouth bass (Micropterus salmoides) to quantify the magnitude of intraspecific variability in functional traits and niche (size, position, and overlap) between age classes. Stable isotope analyses (δ13C and δ15N) were also used to determine the association between individual trophic ecology and intraspecific functional trait variability. We observed that functional traits were highly variable within the population (mean coefficient variation: 15.62% ± 1.78% SE) and predominantly different between age classes. In addition, functional and trophic niche overlap between age classes was extremely low. Differences in functional niche between age classes were associated with strong changes in trophic niche occurring during ontogeny while, within age classes, differences among individuals were likely driven by trophic specialization. Each age class filled only a small portion of the total functional niche of the population and age classes occupied distinct portions in the functional space, indicating the existence of ontogenetic specialists with different functional roles within the population. The high amplitude of intraspecific variability in functional traits and differences in functional niche position among individuals reported here supports the recent claims for an individual-based approach in functional ecology. PMID:25558359
Johnson, Sarah E; Abrams, Marc D
2009-11-01
This study uses data from the International Tree-Ring Data Bank website and tree cores collected in the field to explore growth rate (basal area increment, BAI) relationships across age classes (from young to old) for eight tree species in the eastern US. These species represent a variety of ecological traits and include those in the genera Populus, Quercus, Pinus, Tsuga and Nyssa. We found that most trees in all age classes and species exhibit an increasing BAI throughout their lives. This is particularly unusual for trees in the older age classes that we expected to have declining growth in the later years, as predicted by physiological growth models. There exists an inverse relationship between growth rate and increasing age class. The oldest trees within each species have consistently slow growth throughout their lives, implying an inverse relationship between growth rate and longevity. Younger trees (< 60 years of age) within each species are consistently growing faster than the older trees when they are of the same age resulting from a higher proportion of fast-growing trees in these young age classes. Slow, but increasing, BAI in the oldest trees in recent decades is a continuation of their growth pattern established in previous centuries. The fact that they have not shown a decreasing growth rate in their old age contradicts physiological growth models and may be related to the stimulatory effects of global change phenomenon (climate and land-use history).
NASA Technical Reports Server (NTRS)
Leake, M. A.
1982-01-01
The relative ages of various geologic units and structures place tight constraints on the origin of the Moon and the planet Mercury, and thus provide a better understanding of the geologic histories of these bodies. Crater statistics, a reexamination of lunar geologic maps, and the compilation of a geologic map of a quarter of Mercury's surface based on plains units dated relative to crater degradation classes were used to determine relative ages. This provided the basis for deducing the origin of intercrater plains and their role in terrestrial planet evolution.
Díaz, Mario; Fabelo, Noemí; Ferrer, Isidre; Marín, Raquel
2018-07-01
Lipid rafts are highly dynamic membrane domains featured by distinctive biochemical composition and physicochemical properties compared with the surrounding plasma membrane. These microstructures are associated not only with cellular signaling and communication in normal nerve cells but also with pathological processing of amyloid precursor protein in Alzheimer's disease. Using lipid rafts isolated from human frontal cortex in nondemented subjects aging 24 to 85 years, we demonstrate here that lipid structure of lipid rafts undergo significant alterations of specific lipid classes and phospholipid-bound fatty acids as brain cortex correlating with aging. Main changes affect levels of plasmalogens, polyunsaturated fatty acids (especially docosahexaenoic acid and arachidonic acid), total polar lipids (mainly phosphatidylinositol, sphingomyelin, sulfatides, and cerebrosides), and total neutral lipids (particularly cholesterol and sterol esters). Besides, relevant relationships between main fatty acids and/or lipid classes were altered in an age-related manner. This "lipid raft aging" exhibits clear gender differences and appear to be more pronounced in women than in men, especially in older (postmenopausal) women. The outcomes led us to conclude that human cortical lipid rafts are modified by aging in a gender-dependent fashion. Given the central role of bilayer lipid matrix in lipid rafts functionality and neuronal signaling, we hypothesize that these findings might underlie the higher prevalence of cognitive decline evolving toward Alzheimer's disease in postmenopausal women. Copyright © 2018 Elsevier Inc. All rights reserved.
Body mass and social class: a comparison of Finland and Sweden in the 1990s.
Rahkonen, O; Lundberg, O; Lahelma, E; Huuhka, M
1998-01-01
High physical weight affects public health as well as people's social relations. This study seeks to examine the distribution of physical weight across the social structure in Finland and Sweden in the early 1990s. We compare physical weight, classified by overweight and obesity, 1) between men and women, 2) between different age groups, and 3) between social classes in these two countries. Comparable interview surveys were conducted in Finland 1994 (N = 8,650, response rate 73%) and in Sweden 1991 (N = 5,306, response rate 79%). Physical weight, overweight and obesity of populations are described in terms of body mass index (BMI = weight (kg)/height (m2)). The average BMI is higher in Finnish men (25.6) and women (24.6) than in their Swedish counterparts (24.6 and 23.2, respectively). In both countries, the average BMI is higher in men than in women below the age of about 55-64 years. In both countries and in both genders the average BMI is higher, the higher the age. The level of overweight as well as obesity is lower in Sweden than in Finland. Social class differences can be found in both countries. The odds ratio for overweight is higher in Finnish male and female farmers (OR = 1.57 and 1.94, respectively) as compared to upper white collars (OR = 1.0). In Sweden, high odds ratio for overweight can be found among male entrepreneurs (OR = 1.80) and female unskilled manuals (OR = 2.65). Obesity varies by social class in Swedish men and women as well as in Finnish women, but not in Finnish men. The results show that Finnish men and women are more often overweight and obese than their Swedish counterparts, but social class differences in overweight and obesity are larger in Sweden than in Finland.
Zenebe, Mastewal; Gebremedhin, Samson; Henry, Carol J; Regassa, Nigatu
2018-01-23
School Feeding Program (SFP) is a targeted safety net program designed to provide educational and health benefits to vulnerable children. However, limited evidence exists regarding the effect of the intervention on the nutritional status and school attendance of children. The study is aimed at examining the effects of SFP on dietary diversity, nutritional status and class attendance of school children in Boricha district, Southern Ethiopia. The study was conducted based on a representative data collected from 290 students drawn from the district. A school-based comparative cross-sectional study was conducted on school children aged 10-14 years. Data were collected using structured pretested questionnaire. The effects of SFP on dietary diversity score (DDS), class attendance rate, body-mass-index for age (BAZ) and height-for-age (HAZ) Z-scores were assessed using multivariable linear regression model. The finding showed significantly higher mean (±SD) of DDS in SFP beneficiaries (5.8 ± 1.1) than the non-beneficiaries (3.5 ± 0.7) (P < 0.001). BAZ and HAZ of the beneficiaries were also higher than their counterparts, which were (0.07 ± 0.93), (- 0.50 ± 0.86) and (- 1.45 ± 1.38), (- 2.17 ± 1.15) respectively (P < 0.001). The mean (±SD) days of absence from school for non-beneficiaries (2.6 ± 1.6) was significantly higher than that of the beneficiaries (1.3 ± 1.7) (P < 0.05). Given the positive effects of the program in improving the DDS, nutritional status, and class attendance of school children, we strongly recommend scaling up the program to other food insecure areas.
York, Larry M; Silberbush, Moshe; Lynch, Jonathan P
2016-06-01
Increasing maize nitrogen acquisition efficiency is a major goal for the 21st century. Nitrate uptake kinetics (NUK) are defined by I max and K m, which denote the maximum uptake rate and the affinity of transporters, respectively. Because NUK have been studied predominantly at the molecular and whole-root system levels, little is known about the functional importance of NUK variation within root systems. A novel method was created to measure NUK of root segments that demonstrated variation in NUK among root classes (seminal, lateral, crown, and brace). I max varied among root class, plant age, and nitrate deprivation combinations, but was most affected by plant age, which increased I max, and nitrate deprivation time, which decreased I max K m was greatest for crown roots. The functional-structural simulation SimRoot was used for sensitivity analysis of plant growth to root segment I max and K m, as well as to test interactions of I max with root system architectural phenes. Simulated plant growth was more sensitive to I max than K m, and reached an asymptote near the maximum I max observed in the empirical studies. Increasing the I max of lateral roots had the largest effect on shoot growth. Additive effects of I max and architectural phenes on nitrate uptake were observed. Empirically, only lateral root tips aged 20 d operated at the maximum I max, and simulations demonstrated that increasing all seminal and lateral classes to this maximum rate could increase plant growth by as much as 26%. Therefore, optimizing I max for all maize root classes merits attention as a promising breeding goal. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Cosco, T D; Cooper, R; Kuh, D; Stafford, M
2018-05-01
ABSTRACTBackground:Aging is associated with declines in physical capability; however, some individuals demonstrate high well-being despite this decline, i.e. they are "resilient." We examined socioeconomic position (SEP) and resilience and the influence of potentially modifiable behavioral resources, i.e. social support and leisure time physical activity (LTPA), on these relationships. Data came from the Medical Research Council National Survey of Health and Development, a nationally-representative birth cohort study. Resilience-vulnerability at age 60-64 years (n = 1,756) was operationalized as the difference between observed and expected levels of well-being, captured by the Warwick-Edinburgh Mental Well-being Scale (WEMWBS), given the level of performance-based physical capability. SEP was assessed by father's and own social class, parental education, and intergenerational social mobility. PA and structural/functional social support were reported at ages 53 years and 60-64 years. Path analysis was used to examine mediation of SEP and resilience-vulnerability through LTPA and social support. Participants in the highest social class had scores on the resilience to vulnerability continuum that were an average of 2.3 units (β = 0.46, 95% CI 0.17, 0.75) higher than those in the lowest social class. Greater LTPA (β = 0.58, 95% CI 0.31, 0.85) and social support (β = 3.27, 95% CI 2.90, 3.63) were associated with greater resilience; LTPA partly mediated participant social class and resilience (23.4% of variance). Adult socioeconomic advantage was associated with greater resilience. Initiatives to increase LTPA may contribute to reducing socioeconomic inequalities in this form of resilience in later life.
Heider balance, asymmetric ties, and gender segregation
NASA Astrophysics Data System (ADS)
Krawczyk, Małgorzata J.; del Castillo-Mussot, Marcelo; Hernández-Ramírez, Eric; Naumis, Gerardo G.; Kułakowski, Krzysztof
2015-12-01
To remove a cognitive dissonance in interpersonal relations, people tend to divide their acquaintances into friendly and hostile parts, both groups internally friendly and mutually hostile. This process is modeled as an evolution toward the Heider balance. A set of differential equations have been proposed and validated (Kułakowski et al., 2005) to model the Heider dynamics of this social and psychological process. Here we generalize the model by including the initial asymmetry of the interpersonal relations and the direct reciprocity effect which removes this asymmetry. Our model is applied to the data on enmity and friendship in 37 school classes and 4 groups of teachers in México. For each class, a stable balanced partition is obtained into two groups. The gender structure of the groups reveals stronger gender segregation in younger classes, i.e. of age below 12 years, a fact consistent with other general empirical results.
Age- and gender-specific epistasis between ADA and TNF-α influences human life-expectancy.
Napolioni, Valerio; Carpi, Francesco M; Giannì, Paola; Sacco, Roberto; Di Blasio, Luca; Mignini, Fiorenzo; Lucarini, Nazzareno; Persico, Antonio M
2011-11-01
Aging is a complex phenotype with multiple determinants but a strong genetic component significantly impacts on survival to extreme ages. The dysregulation of immune responses occurring with increasing age is believed to contribute to human morbidity and mortality. Conversely, some genetic determinants of successful aging might reside in those polymorphisms for the immune system genes regulating immune responses. Here we examined the main effects of single loci and multi-locus interactions to test the hypothesis that the adenosine deaminase (ADA) and tumor necrosis factor alpha (TNF-α) genes may influence human life-expectancy. ADA (22G>A, rs73598374) and TNF-α (-308G>A, rs1800629; -238G>A, rs361525) functional SNPs have been determined for 1071 unrelated healthy individuals from Central Italy (18-106 years old) divided into three gender-specific age classes defined according to demographic information and accounting for the different survivals between sexes: for men (women), the first class consists of individuals<66 years old (<73 years old), the second class of individuals 66-88 years old (73-91 years old), and the third class of individuals>88 years old (>91 years old). Single-locus analysis showed that only ADA 22G>A is significantly associated with human life-expectancy in males (comparison 1 (age class 2 vs. age class 1), O.R. 1.943, P=0.036; comparison 2 (age class 3 vs. age class 2), O.R. 0.320, P=0.0056). Age- and gender-specific patterns of epistasis between ADA and TNF-α were found using Generalized Multifactor Dimensionality Reduction (GMDR). In comparison 1, a significant two-loci interaction occurs in females between ADA 22G>A and TNF-α -238G>A (Sign Test P=0.011). In comparison 2, both two-loci and three-loci interaction are significant associated with increased life-expectancy over 88 years in males. In conclusion, we report that a combination of functional SNPs within ADA and TNF-α genes can influence life-expectancy in a gender-specific manner and that males and females follow different pathways to attain longevity. Copyright © 2011 Elsevier Ltd. All rights reserved.
Empirically derived subtypes of serious emotional disturbance in a large adolescent sample.
Peiper, Nicholas; Clayton, Richard; Wilson, Richard; Illback, Robert; O'Brien, Elizabeth; Kerber, Richard; Baumgartner, Richard; Hornung, Carlton
2015-06-01
The heterogeneity of serious emotional disturbance has been thoroughly documented among adolescents with nationally representative data derived from structured interviews, although use of these interviews may not be feasible within the context of brief and self-administered school surveys. This study seeks to identify distinct subtypes of serious emotional disturbance in a large school-based sample. A total of 108,736 students fully completed the K6 scale that was included on the 2012 Kentucky Incentives for Prevention Survey. Latent class analysis was used to derive subtypes of serious emotional disturbance among students receiving a positive screen (n = 15,147). To determine significant predictors of class membership, adjusted rate ratios and 95 % confidence intervals were calculated using multinomial logistic regression. A four-class model was the most parsimonious, with four distinct subtypes emerging that varied by both symptom type and severity: comorbid moderate severity, comorbid high severity, anxious moderate severity, and depressed high severity. Age, gender, race/ethnicity, family structure, substance use, antisocial behavior, role impairments, and peer victimization were significant predictors of class membership, although the magnitude of these effects was stronger for the two high severity groups. Our results suggest heterogeneity of serious emotional disturbance by both symptom type and severity. Prevention programs may benefit by shifting focus from specific disorders to the core features of serious emotional disturbance, including psychological distress, high comorbidity, and role impairments.
Xerostomia is associated with old age and poor appetite in patients on chronic hemodialysis.
Bossola, Maurizio; Di Stasio, Enrico; Giungi, Stefania; Vulpio, Carlo; Papa, Valerio; Rosa, Fausto; Tortorelli, Antonio; Tazza, Luigi
2013-11-01
The objective of this study was to assess variables associated with xerostomia in patients on chronic hemodialysis (HD). This was a cross-sectional study of 75 HD patients at an outpatient HD service. Demographic, clinical (renal disease, HD regimen/duration, Charlson comorbidity index, activities of daily living, instrumental activities of daily living [IADL], body mass index), and laboratory (hemoglobin, albumin, interleukin-6 [IL-6], and parathyroid hormone) parameters were recorded. We assessed the appetite through the Hemodialysis Study Appetite questionnaire and xerostomia through the Xerostomia Inventory (XI). A single question ("How often does your mouth feel dry?"; never = Class 1, almost never = Class 2, occasionally = Class 3, often = Class 4, very often = Class 5) was also included in the study questionnaire. The main outcome measure was factors correlated with XI. The median XI score was 18 (min-max = 11-33). Forty patients had an XI score of 18 or less (Group 1) and between 18 and 35 (Group 2). In Group 2, age, Charlson comorbidity index score, and number of patients with poor/very poor appetite were significantly higher. At the univariate analysis, the score of the XI was significantly associated with age, appetite, IADL, Charlson comorbidity index, and serum IL-6 levels. Multiple linear regression analysis showed that the XI was independently associated with age and appetite. Thirty-one patients were in Class 1 to 2, 23 were in Class 3, and 21 were in Class 4 to 5. In Classes 4 to 5, age and the number of patients with poor/very poor appetite were higher (P = .012 and .09, respectively). Xerostomia is associated with old age and poor appetite in patients on chronic HD. Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
David S. Graves; James W. Burns
1970-01-01
Yields of juvenile steelhead rainbow trout Salmo gairdnerii gairdnerii) and silver salmon (Oncorhynchus kisutch) emigrants were compared in South Fork Caspar Creek, a small coastal stream in Mendocino County, California, before and after construction of a logging road along the stream in the summer of 1967. Numbers, lengths, and age class structures were compared....
Gaylord-Harden, Noni K; Dickson, Daniel; Pierre, Cynthia
2016-07-01
The current study employed latent class analysis (LCA) to identify distinct profiles of community violence exposure and their associations to desensitization outcomes in 241 African American early adolescents (M age = 12.86, SD = 1.28) in the sixth through eighth grade from under-resourced urban communities. Participants self-reported on their exposure to community violence, as well as on depressive and anxiety symptoms. The LCA revealed three distinct classes: a class exposed to low levels of violence (low exposure class), a class exposed to moderately high levels of victimization (victimization class), and a class exposed to high levels of all types of violence (high exposure class). Consistent with predictions, the high exposure class showed the lowest levels of depressive symptoms, suggesting a desensitization outcome. Gender and age were also examined in relation to the classes, and age was significantly associated with an increased risk of being a member of the high exposure class relative to the low exposure class. Using person-based analyses to examine desensitization outcomes provides useful information for prevention and intervention efforts, as it helps to identify a specific subgroup of youth that may be more likely to show desensitization outcomes in the context of community violence. © The Author(s) 2015.
Kasmel, Jaan; Kaarma, Helje; Koskel, Säde; Tiit, Ene-Margit
2004-03-01
A total of 462 schoolgirls aged 7-8 and 17-18 years were examined anthropometrically (45 body measurements and 10 skinfolds) in a cross-sectional study. The data were processed in two age groups: 7-8-year-olds (n = 205) and 17-18-year-olds (n = 257). Relying on average height and weight in the groups, both groups were divided into five body build classes: small, medium, large, pyknomorphous and leptomorphous. In these classes, the differences in all other body measurements were compared, and in both age groups, analogous systematic differences were found in length, width and depth measurements and circumferences. This enabled us to compare proportional changes in body measurements during ten years, using for this ratios of averages of basic measurements and measurement groups in the same body build classes. Statistical analysis by the sign test revealed statistically significant differences between various body build classes in the growth of averages. Girls belonging to the small class differed from the girls of the large class by an essentially greater increase in their measurements. Our results suggest that the growth rate of body measurements of girls with different body build can be studied by the help of body build classification.
Ontology for Structural Geology
NASA Astrophysics Data System (ADS)
Zhong, J.; McGuinness, D. L.; Antonellini, M.; Aydin, A.
2005-12-01
We present our comprehensive process-based ontology for Structural Geology. This ontology covers major domain concepts, especially those related to geological structure type, properties of these structures, their deformation mechanisms, and the factors that control which deformation mechanisms may operate under certain conditions. The structure class in our ontology extends the planetary structure class of the SWEET ontology by providing additional information required for use in the structural geology domain. The classification followed the architectures of structures, such as structure element, set, zone, and pattern. Our deformation mechanism class does not have a corresponding class in SWEET. In our ontology, it has two subclasses, Macro- and Micro- mechanisms. The property class and the factor class are both subclasses of the physical property class of SWEET. Relationships among those concepts are also included in our ontology. For example, the class structure element has properties associated with the deformation mechanisms, descriptive properties such as geometry and morphology, and physical properties of rocks such as strength, compressibility, seismic velocity, porosity, and permeability. The subject matter expertise was provided by domain experts. Additionally, we surveyed text books and journal articles with the goal of evaluating the completeness and correctness of the domain terms and we used logical reasoners and validators to eliminate logical problems. We propose that our ontology provides a reusable extension to the SWEET ontology that may be of value to scientists and lay people interested in structural geology issues. We have also implemented prototype services that utilize this ontology for search.
Hart, Carole L; McCartney, Gerry; Watt, Graham C M
2015-05-01
population ageing challenges the sustainability of healthcare provision. to investigate occupational class differences in hospital use in women aged 80+ years. a total of 8,353 female residents, aged 45-64, took part in the Renfrew and Paisley prospective cohort study in 1972-76. Information on general and mental health hospital discharges was provided from computerised linkage with the Scottish Morbidity Records data to 31 December 2012. Numbers of admissions and bed-days after the 80th birthday were calculated for all and specific causes. Rate ratios by occupational class were calculated using negative binomial regression analysis, adjusting for age and a range of risk factors. four thousand and four hundred and seven (56%) women survived to age 80 and had 17,563 general admissions thereafter, with a mean stay of 19.4 days. There were no apparent relationships with occupational class for all general admissions, but lower occupational class was associated with higher rate ratios for coronary heart disease and stroke and lower rate ratios for cancer. Adjustment for risk factors could not fully explain the raised rate ratios. Bed-day use was higher in lower occupational classes, especially for stroke. There were strong associations with mental health admissions, especially dementia. Compared with the highest occupational class, admission rate ratios for dementia were higher for the lowest occupational class (adjusted rate ratio = 2.60, 95% confidence interval 1.79-3.77). in this population, there were no socio-economic gradients seen in hospital utilisation for general admissions in old age. However, occupational class was associated with mental health admissions, coronary heart disease, stroke and cancer. © The Author 2014. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
James M. Vose; Paul V. Bolstad
2007-01-01
We measured forest floor CO2 flux in three age classes of forest in the southern Appalachians: 20-year-old, 85-year-old, and old-growth. Our objectives were to quantify differences in forest floor CO2 flux among age classes, and determine the relative importance of abiotic and biotic driving variables. Forest floor CO
Madsen, Vinni; Dabelsteen, Torben; Osorio, Daniel; Osorno, José Luis
2007-01-01
Male magnificent frigatebird (Fregata magnificens) ornamentation includes bright iridescent plumage and a red inflatable gular pouch. These signals are displayed during courtship, along with a drumming sound produced through specialized beak clackings resonating in the gular pouch. The extent of white in the plumage identifies three age classes of nonjuvenile male. Here we investigate how morphological and secondary sexual traits correlate with age class and mating status. Even though several age class-related differences in morphology and visual appearance can be identified, the only features that significantly predict mating success are acoustic components of courtship display. Specifically, males that mate drum at lower fundamental frequencies--that is, they have larger gular pouches--and have a quicker and more constant drumming cadence than unsuccessful males. The fundamental frequency decreases with age class, reflecting an increase in gular pouch size. This implies that females prefer older or possibly more experienced or viable males. Drumming cadence speed and stability might reflect male stamina. Apart from the acoustic differences with mating status, there is a nonsignificant tendency for back-feather iridescence to be of shorter reflectance wavelength spectra in mated than in unmated males, which, when combined with acoustic variables, improves prediction of age class and mating status.
Gasull, Magda; Pumarega, José; Rovira, Gemma; López, Tomàs; Alguacil, Juan; Porta, Miquel
2013-10-01
Scant evidence is available worldwide on the relative influence of occupational social class and educational level on body concentrations of persistent organic pollutants (POPs) in the general population. The objective was to analyse such influence in a representative sample of the general population of Catalonia, Spain. Participants in the Catalan Health Interview Survey aged 18-74 were interviewed face-to-face, gave blood, and underwent a physical exam. The role of age, body mass index (BMI), and parity was analysed with General Linear Models, and adjusted geometric means (GMs) were obtained. Crude (unadjusted) concentrations were higher in women and men with lower education, and in women, but not men, in the less affluent social class. After adjusting for age, in women there were no associations between POP levels and social class or education. After adjusting for age and BMI, men in the less affluent class had higher p,p'-DDE concentrations than men in class I (p-value=0.016), while men in class IV had lower HCB than men in the upper class (p-value<0.03). Also in contrast with some expectations, positive associations between education and POP levels were observed after adjusting for age and BMI in men; e.g., men with university studies had higher HCB concentrations than men with first stage of primary schooling (adjusted GM 153.9 and 80.5ng/g, respectively) (p-value<0.001). When education and social class were co-adjusted for, some positive associations with education in men remained statistically significant, whereas class remained associated only with p,p'-DDE. Educational level influenced blood concentrations of POPs more than occupational social class, especially in men. In women, POP concentrations were mainly explained by age/birth cohort, parity and BMI. In men, while concentrations were also mainly explained by age/birth cohort and BMI, both social class and education showed positive associations. Important characteristics of socioeconomic groups as age and BMI may largely explain crude differences among such groups in internal contamination by POPs. The absence of clear patterns of relationships between blood concentrations of POPs and indicators of socioeconomic position may fundamentally be due to the widespread, lifelong, and generally invisible contamination of human food webs. Decreasing historical trends would also partly explain crude socioeconomic differences apparently due to birth cohort effects. © 2013 Elsevier Ltd. All rights reserved.
Spatio-temporal dynamics of pneumonia in bighorn sheep
Cassirer, E. Frances; Plowright, Raina K.; Manlove, Kezia R.; Cross, Paul C.; Dobson, Andrew P.; Potter, Kathleen A.; Hudson, Peter J.
2013-01-01
Bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western North America, but management has been constrained by an incomplete understanding of the disease. We analysed patterns of pneumonia-caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes. 2. We observed four age-structured classes of annual pneumonia mortality patterns: all-age, lamb-only, secondary all-age and adult-only. Although there was considerable variability within classes, overall they differed in persistence within and impact on populations. Years with pneumonia-induced mortality occurring simultaneously across age classes (i.e. all-age) appeared to be a consequence of pathogen invasion into a naïve population and resulted in immediate population declines. Subsequently, low recruitment due to frequent high mortality outbreaks in lambs, probably due to association with chronically infected ewes, posed a significant obstacle to population recovery. Secondary all-age events occurred in previously exposed populations when outbreaks in lambs were followed by lower rates of pneumonia-induced mortality in adults. Infrequent pneumonia events restricted to adults were usually of short duration with low mortality. 3. Acute pneumonia-induced mortality in adults was concentrated in fall and early winter around the breeding season when rams are more mobile and the sexes commingle. In contrast, mortality restricted to lambs peaked in summer when ewes and lambs were concentrated in nursery groups. 4. We detected weak synchrony in adult pneumonia between adjacent populations, but found no evidence for landscape-scale extrinsic variables as drivers of disease. 5. We demonstrate that there was a >60% probability of a disease event each year following pneumonia invasion into bighorn sheep populations. Healthy years also occurred periodically, and understanding the factors driving these apparent fade-out events may be the key to managing this disease. Our data and modelling indicate that pneumonia can have greater impacts on bighorn sheep populations than previously reported, and we present hypotheses about processes involved for testing in future investigations and management.
Parikh, Shanti A.
2011-01-01
In 1990 women’s rights activists in Uganda successfully lobbied to amend the Defilement Law, raising the age of sexual consent for adolescent females from fourteen to eighteen years old and increasing the maximum sentence to death by hanging. The amendment can be considered a macro-level intervention designed to address the social and health inequalities affecting young women and girls, particularly their disproportionately high rate of HIV as compared to their male counterparts. While the intention of the law and aggressive campaign was to prosecute “sugar daddies” and “pedophiles,” the average age of men charged with defilement was twenty-one years old and many were believe to be “boyfriends” in consensual sexual liaisons with the alleged victims. This article uses court records, case studies, and longitudinal ethnographic data gathered in central-eastern Uganda to examine the impact of the age of consent law at national and local levels, and specifically what the disjunctures between national intentions and local uses reveal about conflicting views about the sexual privilege and rights. I argue that existing class, gender, and age hierarchies have shaped how the Defilement Law has been applied locally, such that despite the stated aim of “protecting” young women, the law reinstates patriarchal privilege (especially against men of lower social class) while simultaneously increasing the regulation of adolescent female sexuality and undermining their autonomy. This paper demonstrates how ethnography and gender theory—which emphasizes the intersectionality of gender, age, and class in the (re)production of inequalities—can be used to examine consequences of macro-level interventions in ways that may be undetected in conventional public health evaluation techniques but that are crucial for designing and modifying effective interventions. PMID:21824700
Parikh, Shanti A
2012-06-01
In 1990 women's rights activists in Uganda successfully lobbied to amend the Defilement Law, raising the age of sexual consent for adolescent females from fourteen to eighteen years old and increasing the maximum sentence to death by hanging. The amendment can be considered a macro-level intervention designed to address the social and health inequalities affecting young women and girls, particularly their disproportionately high rate of HIV as compared to their male counterparts. While the intention of the law and aggressive campaign was to prosecute "sugar daddies" and "pedophiles," the average age of men charged with defilement was twenty-one years old and many were believe to be "boyfriends" in consensual sexual liaisons with the alleged victims. This article uses court records, case studies, and longitudinal ethnographic data gathered in east-central Uganda to examine the impact of the age of consent law at national and local levels, and specifically what the disjunctures between national intentions and local uses reveal about conflicting views about sexual privilege and rights. I argue that existing class, gender, and age hierarchies have shaped how the Defilement Law has been applied locally, such that despite the stated aim of "protecting" young women, the law reinstates patriarchal privilege (especially against men of lower social class) while simultaneously increasing the regulation of adolescent female sexuality and undermining their autonomy. This paper demonstrates how ethnography and critical gender theory-which emphasizes the intersectionality of gender, age, and class in the (re)production of inequalities-can be used to examine consequences of macro-level interventions in ways that may be undetected in conventional public health evaluation techniques but that are crucial for designing and modifying effective interventions. Copyright © 2011 Elsevier Ltd. All rights reserved.
Liu, Jiankang; Zhang, Kebin
2018-05-09
Enclosure is an effective practice for restoring and rehabilitating the degraded grassland ecosystem caused by overgrazing. Shrub species, which are dominant in most desert grasslands in arid and semiarid regions, have some beneficial ecological functions for grassland restoration. However, how the population structure and spatial pattern of the Artemisia ordosica shrub changes in a grassland ecosystem under enclosed practice is not well understood. This study, conducted in the Mu Us desert in northwest China, was designed to measure the A. ordosica population according to the chronosequence of enclosure (enclosure periods ranged from 5 years, 10 years, 15 years, and 25 years), contrasting this with an adjacent continuously grazed grassland. The results showed that the enclosed grasslands had a higher number of individuals of different age classes (seedling, adult, aging, and dead group) and greater population coverage, but shrubs had significant lower ( p < 0.05) crown diameter and height in comparison with those in continuously grazed grassland. Further, enclosed grasslands had a significantly higher ( p < 0.05) Shannon-Wiener index (H) and Evenness index (E), but a significantly lower ( p < 0.05) Richness index (R) than continuously grazed grassland. The crown of A. ordosica showed a significant linear positive correlation with height in all plots across succession, indicating that it was feasible to analyze the age structure by crown. The crown-class distribution structure of the A. ordosica population approximated a Gaussian distribution model in all survey plots. Within the population, seedling and adult groups exhibited aggregated spatial distribution at small scales, while aging and dead A. ordosica groups showed random distribution at almost all scales in different plots. The seedling A. ordosica group showed a positive correlation with adults at small scales in all plots except in 10 years of enclosure. However, it showed independent correlation with aging and dead groups at almost all scales. In long-term enclosed plots, the mortality rate of the A. ordosica population increased, therefore assistance management practices, such as fertilization, mowing, interval grazing, and seasonal grazing, must be employed to maintain population stability after long-term enclosure. This study can improve understanding and clarify the effects of enclosures in the desert grasslands of northwest China.
Lemasson, Alban; Nagumo, Sumiharu; Masataka, Nobuo
2012-01-01
Despite not knowing the exact age of individuals, humans can estimate their rough age using age-related physical features. Nonhuman primates show some age-related physical features; however, the cognitive traits underlying their recognition of age class have not been revealed. Here, we tested the ability of two species of Old World monkey, Japanese macaques (JM) and Campbell's monkeys (CM), to spontaneously discriminate age classes using visual paired comparison (VPC) tasks based on the two distinct categories of infant and adult images. First, VPCs were conducted in JM subjects using conspecific JM stimuli. When analyzing the side of the first look, JM subjects significantly looked more often at novel images. Based on analyses of total looking durations, JM subjects looked at a novel infant image longer than they looked at a familiar adult image, suggesting the ability to spontaneously discriminate between the two age classes and a preference for infant over adult images. Next, VPCs were tested in CM subjects using heterospecific JM stimuli. CM subjects showed no difference in the side of their first look, but looked at infant JM images longer than they looked at adult images; the fact that CMs were totally naïve to JMs suggested that the attractiveness of infant images transcends species differences. This is the first report of visual age class recognition and a preference for infant over adult images in nonhuman primates. Our results suggest not only species-specific processing for age class recognition but also the evolutionary origins of the instinctive human perception of baby cuteness schema, proposed by the ethologist Konrad Lorenz. PMID:22685529
Sato, Anna; Koda, Hiroki; Lemasson, Alban; Nagumo, Sumiharu; Masataka, Nobuo
2012-01-01
Despite not knowing the exact age of individuals, humans can estimate their rough age using age-related physical features. Nonhuman primates show some age-related physical features; however, the cognitive traits underlying their recognition of age class have not been revealed. Here, we tested the ability of two species of Old World monkey, Japanese macaques (JM) and Campbell's monkeys (CM), to spontaneously discriminate age classes using visual paired comparison (VPC) tasks based on the two distinct categories of infant and adult images. First, VPCs were conducted in JM subjects using conspecific JM stimuli. When analyzing the side of the first look, JM subjects significantly looked more often at novel images. Based on analyses of total looking durations, JM subjects looked at a novel infant image longer than they looked at a familiar adult image, suggesting the ability to spontaneously discriminate between the two age classes and a preference for infant over adult images. Next, VPCs were tested in CM subjects using heterospecific JM stimuli. CM subjects showed no difference in the side of their first look, but looked at infant JM images longer than they looked at adult images; the fact that CMs were totally naïve to JMs suggested that the attractiveness of infant images transcends species differences. This is the first report of visual age class recognition and a preference for infant over adult images in nonhuman primates. Our results suggest not only species-specific processing for age class recognition but also the evolutionary origins of the instinctive human perception of baby cuteness schema, proposed by the ethologist Konrad Lorenz.
Sumanen, Hilla; Lahelma, Eero; Pietiläinen, Olli; Rahkonen, Ossi
2017-06-09
Background : Our aim was to examine the magnitude of relative occupational class differences in sickness absence (SA) days over a 15-year period among female and male municipal employees in two age-groups. Methods : 18-34 and 35-59-year-old employees of the City of Helsinki from 2002 to 2016 were included in our data ( n = ~37,500 per year). Occupational class was classified into four groups. The magnitude of relative occupational class differences in SA was studied using the relative index of inequality (RII). Results : The relative occupational class differences were larger among older than younger employees; the largest differences were among 35-59-year-old men. Among women in both age-groups the relative class differences remained stable during 2002-2016. Among younger and older men, the differences were larger during the beginning of study period than in the end. Among women in both age-groups the RII values were between 2.19 (95% confidence intervals (CI) 1.98, 2.42) and 3.60 (95% CI 3.28, 3.95). The corresponding differences varied from 3.74 (95% CI 3.13, 4.48) to 1.68 (95% CI 1.44, 1.97) among younger and from 6.43 (95% CI 5.85, 7.06) to 3.31 (95% CI 2.98, 3.68) among older men. Relative occupational class differences were persistent among employees irrespective of age group and gender. Preventive measures should be started at young age.
Mizianty, Marcin J; Kurgan, Lukasz
2009-12-13
Knowledge of structural class is used by numerous methods for identification of structural/functional characteristics of proteins and could be used for the detection of remote homologues, particularly for chains that share twilight-zone similarity. In contrast to existing sequence-based structural class predictors, which target four major classes and which are designed for high identity sequences, we predict seven classes from sequences that share twilight-zone identity with the training sequences. The proposed MODular Approach to Structural class prediction (MODAS) method is unique as it allows for selection of any subset of the classes. MODAS is also the first to utilize a novel, custom-built feature-based sequence representation that combines evolutionary profiles and predicted secondary structure. The features quantify information relevant to the definition of the classes including conservation of residues and arrangement and number of helix/strand segments. Our comprehensive design considers 8 feature selection methods and 4 classifiers to develop Support Vector Machine-based classifiers that are tailored for each of the seven classes. Tests on 5 twilight-zone and 1 high-similarity benchmark datasets and comparison with over two dozens of modern competing predictors show that MODAS provides the best overall accuracy that ranges between 80% and 96.7% (83.5% for the twilight-zone datasets), depending on the dataset. This translates into 19% and 8% error rate reduction when compared against the best performing competing method on two largest datasets. The proposed predictor provides accurate predictions at 58% accuracy for membrane proteins class, which is not considered by majority of existing methods, in spite that this class accounts for only 2% of the data. Our predictive model is analyzed to demonstrate how and why the input features are associated with the corresponding classes. The improved predictions stem from the novel features that express collocation of the secondary structure segments in the protein sequence and that combine evolutionary and secondary structure information. Our work demonstrates that conservation and arrangement of the secondary structure segments predicted along the protein chain can successfully predict structural classes which are defined based on the spatial arrangement of the secondary structures. A web server is available at http://biomine.ece.ualberta.ca/MODAS/.
2009-01-01
Background Knowledge of structural class is used by numerous methods for identification of structural/functional characteristics of proteins and could be used for the detection of remote homologues, particularly for chains that share twilight-zone similarity. In contrast to existing sequence-based structural class predictors, which target four major classes and which are designed for high identity sequences, we predict seven classes from sequences that share twilight-zone identity with the training sequences. Results The proposed MODular Approach to Structural class prediction (MODAS) method is unique as it allows for selection of any subset of the classes. MODAS is also the first to utilize a novel, custom-built feature-based sequence representation that combines evolutionary profiles and predicted secondary structure. The features quantify information relevant to the definition of the classes including conservation of residues and arrangement and number of helix/strand segments. Our comprehensive design considers 8 feature selection methods and 4 classifiers to develop Support Vector Machine-based classifiers that are tailored for each of the seven classes. Tests on 5 twilight-zone and 1 high-similarity benchmark datasets and comparison with over two dozens of modern competing predictors show that MODAS provides the best overall accuracy that ranges between 80% and 96.7% (83.5% for the twilight-zone datasets), depending on the dataset. This translates into 19% and 8% error rate reduction when compared against the best performing competing method on two largest datasets. The proposed predictor provides accurate predictions at 58% accuracy for membrane proteins class, which is not considered by majority of existing methods, in spite that this class accounts for only 2% of the data. Our predictive model is analyzed to demonstrate how and why the input features are associated with the corresponding classes. Conclusions The improved predictions stem from the novel features that express collocation of the secondary structure segments in the protein sequence and that combine evolutionary and secondary structure information. Our work demonstrates that conservation and arrangement of the secondary structure segments predicted along the protein chain can successfully predict structural classes which are defined based on the spatial arrangement of the secondary structures. A web server is available at http://biomine.ece.ualberta.ca/MODAS/. PMID:20003388
Mapping Successional Stages in a Wet Tropical Forest Using Landsat ETM+ and Forest Inventory Data
NASA Technical Reports Server (NTRS)
Goncalves, Fabio G.; Yatskov, Mikhail; dos Santos, Joao Roberto; Treuhaft, Robert N.; Law, Beverly E.
2010-01-01
In this study, we test whether an existing classification technique based on the integration of Landsat ETM+ and forest inventory data enables detailed characterization of successional stages in a wet tropical forest site. The specific objectives were: (1) to map forest age classes across the La Selva Biological Station in Costa Rica; and (2) to quantify uncertainties in the proposed approach in relation to field data and existing vegetation maps. Although significant relationships between vegetation height entropy (a surrogate for forest age) and ETM+ data were detected, the classification scheme tested in this study was not suitable for characterizing spatial variation in age at La Selva, as evidenced by the error matrix and the low Kappa coefficient (12.9%). Factors affecting the performance of the classification at this particular study site include the smooth transition in vegetation structure between intermediate and advanced successional stages, and the low sensitivity of NDVI to variations in vertical structure at high biomass levels.
Brett, Caroline E.; Starr, John M.; Deary, Ian J.
2016-01-01
Abstract Recent observations that personality traits are related to later‐life health and wellbeing have inspired considerable interest in exploring the mechanisms involved. Other factors, such as cognitive ability and education, also show longitudinal influences on health and wellbeing, but it is not yet clear how all these early‐life factors together contribute to later‐life health and wellbeing. In this preliminary study, we assessed hypothesised relations among these variables across the life course, using structural equation modelling in a sample assessed on dependability (a personality trait related to conscientiousness) in childhood, cognitive ability and social class in childhood and older age, education, and health and subjective wellbeing in older age. Our models indicated that both health and subjective wellbeing in older age were influenced by childhood IQ and social class, via education. Some older‐age personality traits mediated the effects of early‐life variables, on subjective wellbeing in particular, but childhood dependability did not show significant associations. Our results therefore did not provide evidence that childhood dependability promotes older‐age health and wellbeing, but did highlight the importance of other early‐life factors, particularly characteristics that contribute to educational attainment. Further, personality in later life may mediate the effects of early‐life factors on health and subjective wellbeing. © 2016 The Authors. European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology PMID:27867259
Wolf, T E; Bennett, N C; Burroughs, R; Ganswindt, A
2018-01-01
One of the primary sources of perceived stress is the social environment of an animal and the interactions with conspecifics. An essential component of the response to a stressor is the activation of the hypothalamic-pituitary-adrenocortical axis, which results amongst others in a temporal increase in circulating glucocorticoid (GC) levels. Giraffes occur in a highly flexible fission-fusion social system and group compositions can change on a daily basis, with bulls establishing an age-related dominance hierarchy and showing a roaming strategy in the search for fertile females. The aim of this study was to non-invasively monitor the influence of different group compositions (mixed sex groups vs. all-male groups) on GC concentrations in free ranging giraffe bulls of different age classes. We collected fecal samples from free-ranging giraffe bulls for 12months in a South African Private Game Reserve to examine age- and social context-related patterns of fecal GC metabolite (fGCM) concentrations. We found that fGCM levels in giraffe bulls are age-class dependent, as well asassociated with changes in the social environment. Independently of the social setting, bulls of the youngest age class exhibited the highest fGCM levels compared to bulls of the other two older age-classes, with differences most pronounced when the bulls are associated in all-male groups. In contrast, an almost reversed picture appears when looking at the fGCM levels of sexually active individuals in mixed sex groups, where highest levels were found for the bulls in the oldest age-class, and the lowest for the bulls in the youngest age-class. The study stresses the importance to taking factors such asage-related status and social settings into account, when interpreting fGCM levels in free ranging giraffes. Copyright © 2017 Elsevier Inc. All rights reserved.
Leinonen, Taina; Viikari-Juntura, Eira; Husgafvel-Pursiainen, Kirsti; Solovieva, Svetlana
2018-04-07
We aimed to provide previously unestablished information on population-based differences in cause-specific sickness absence trends between occupational classes and further between four large industrial sectors within the different occupational classes while controlling for other socioeconomic factors and employment patterns. We focused on the period 2005-2013, during which the labour market underwent large economic and structural changes in many countries. Register-based panel data study. Large representative datasets on Finnish wage earners aged 25-59 years. Annual risk of sickness absence (>10 working days) based on repeated logistic regression. Between 2005 and 2013, the proportion of employees with sickness absence decreased. Occupational class differences in sickness absence trends varied by disease group. Overall, the decrease in absences was smallest among lower non-manual employees. Sickness absence levels were highest in the health and social work sector and in the manufacturing sector within the non-manual and manual classes, respectively. Absences due to musculoskeletal diseases decreased temporarily during the peak of the economic recession in 2009, particularly in the manufacturing sector within the manual class. The decrease in absences due to musculoskeletal diseases was smallest in the trade sector within the lower occupational classes. Overall, education, income and employment patterns partly explained the differences in the absence levels, but not in the trends. We found a complex interplay between the associations of occupational class and industrial sector with sickness absence trends. During the economic recession, absences due to musculoskeletal diseases decreased temporarily in a segment of wage earners who were known to have been hit hard by the recession. However, the trend differences were not explained by the measured structural changes in the characteristics of the study population. Both occupational class and industrial sector should be taken into account when tackling problems of work disability. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
McGowan, C.P.; Millspaugh, J.J.; Ryan, M.R.; Kruse, C.D.; Pavelka, G.
2009-01-01
Estimating reproductive success for birds with precocial young can be difficult because chicks leave nests soon after hatching and individuals or broods can be difficult to track. Researchers often turn to estimating survival during the prefledging period and, though effective, mark-recapture based approaches are not always feasible due to cost, time, and animal welfare concerns. Using a threatened population of Piping Plovers (Charadrius melodus) that breeds along the Missouri River, we present an approach for estimating chick survival during the prefledging period using long-term (1993-2005), count-based, age-class data. We used a modified catch-curve analysis, and data collected during three 5-day sampling periods near the middle of the breeding season. The approach has several ecological and statistical assumptions and our analyses were designed to minimize the probability of violating those assumptions. For example, limiting the sampling periods to only 5 days gave reasonable assurance that population size was stable during the sampling period. Annual daily survival estimates ranged from 0.825 (SD = 0.03) to 0.931 (0.02) depending on year and sampling period, with these estimates assuming constant survival during the prefledging period and no change in the age structure of the population. The average probability of survival to fledging ranged from 0.126 to 0.188. Our results are similar to other published estimates for this species in similar habitats. This method of estimating chick survival may be useful for a variety of precocial bird species when mark-recapture methods are not feasible and only count-based age class data are available. ?? 2009 Association of Field Ornithologists.
Social class difference in catch up growth in a national British cohort
Teranishi, H; Nakagawa, H; Marmot, M
2001-01-01
AIM—To examine the influence of socioeconomic status on growth pattern in height from age 7 to 23years. METHODS—Prospective cohort study. A total of 10 200 white singleton born children from the 1958 British birth cohort (National Child Development Study) were analysed. RESULTS—Differences in height by birth weight persisted throughout the follow up period. However, the mean differences in height between low birth weight infants (<2500 g) and adequate birth weight infants (⩾2500 g) were less notable in social classes I and II than in the lower social classes. The catching up of growth in height of low birth weight infants was also more pronounced in social classes I and II than in other social classes. That is, the mean height deficits of low birth weight infants were decreased from 2.9 cm at age 7, to 1.6 cm at age 16, and 2.5 cm at age 23; the significant difference disappeared after age 16 in social classes I and II. Although such improving tendency was more pronounced among the preterm born infants, a similar growth pattern was observed among the term infants. Such improvement was not observed in the other social classes. CONCLUSION—The growth retardation in height by birth weight can be overcome by improved social conditions and proper health care from childhood to adulthood. PMID:11207167
Green, M J; Benzeval, M
2011-03-01
Understanding how common mental disorders such as anxiety and depression vary with socio-economic circumstances as people age can help to identify key intervention points. However, much research treats these conditions as a single disorder when they differ significantly in terms of their disease burden. This paper examines the socio-economic pattern of anxiety and depression separately and longitudinally to develop a better understanding of their disease burden for key social groups at different ages. The Twenty-07 Study has followed 4510 respondents from three cohorts in the West of Scotland for 20 years and 3846 respondents had valid data for these analyses. Hierarchical repeated-measures models were used to investigate the relationship between age, social class and the prevalence of anxiety and depression over time measured as scores of 8 or more out of 21 on the relevant subscale of the Hospital Anxiety and Depression Scale (HADS). Social class differences in anxiety and depression widened with age. For anxiety there was a nonlinear decrease in prevalence with age, decreasing more slowly for those from manual classes compared to non-manual, whereas for depression there was a non-linear increase in prevalence with age, increasing more quickly for those from manual classes compared to non-manual. This relationship is robust to cohort, period and attrition effects. The more burdensome disorder of depression occurs more frequently at ages where socio-economic inequalities in mental health are greatest, representing a 'double jeopardy' for older people from a manual class.
Body mass trajectories, diabetes mellitus, and mortality in a large cohort of Austrian adults.
Peter, Raphael Simon; Keller, Ferdinand; Klenk, Jochen; Concin, Hans; Nagel, Gabriele
2016-12-01
There are only few studies on latent trajectories of body mass index (BMI) and their association with diabetes incidence and mortality in adults.We used data of the Vorarlberg Health Monitoring & Prevention Program and included individuals (N=24,875) with BMI measurements over a 12-year period. Trajectory classes were identified using growth mixture modeling for predefined age groups (<50, 50-65, >65 years of age) and men, women separately. Poisson models were applied to estimate incidence and prevalence of diabetes for each trajectory class. Relative all-cause mortality and diabetes-related mortality was estimated using Cox proportional hazard regression.We identified 4 trajectory classes for the age groups <50 years and 50 to 65 years, and 3 for age groups >65 years. For all age groups, a stable BMI trajectory class was the largest, with about 90% of men and 70% to 80% of women. For the low stable BMI classes, the corresponding fasting glucose levels were the lowest. The highest diabetes prevalences were observed for decreasing trajectories. During subsequent follow-up of mean 8.1 (SD 2.0) years, 2741 individuals died. For men <50 years, highest mortality was observed for steady weight gainers. For all other age-sex groups, mortality was the highest for decreasing trajectories.We found considerably heterogeneity in BMI trajectories by sex and age. Stable weight, however, was the largest class over all age and sex groups, and was associated with the lowest diabetes incidence and mortality suggesting that maintaining weight at a moderate level is an important public health goal.
Structural (Performance) class Potential for North America
Eric Jones; David E. Kretschmann; Kevin Cheung
2014-01-01
Structural class systems are species-independent product classification systems for structural timber. They are used throughout the world to reduce the number of species and grade choices that face the designer of wood construction projects. Structural class systems offer an opportunity to simplify timber specification in North America and to encourage more effective...
Persistence versus extinction for a class of discrete-time structured population models.
Jin, Wen; Smith, Hal L; Thieme, Horst R
2016-03-01
We provide sharp conditions distinguishing persistence and extinction for a class of discrete-time dynamical systems on the positive cone of an ordered Banach space generated by a map which is the sum of a positive linear contraction A and a nonlinear perturbation G that is compact and differentiable at zero in the direction of the cone. Such maps arise as year-to-year projections of population age, stage, or size-structure distributions in population biology where typically A has to do with survival and individual development and G captures the effects of reproduction. The threshold distinguishing persistence and extinction is the principal eigenvalue of (II−A)(−1)G'(0) provided by the Krein-Rutman Theorem, and persistence is described in terms of associated eigenfunctionals. Our results significantly extend earlier persistence results of the last two authors which required more restrictive conditions on G. They are illustrated by application of the results to a plant model with a seed bank.
Chambers, Robert S.; Tandon, Rajan; Stavig, Mark E.
2015-07-07
In this study, to analyze the stresses and strains generated during the solidification of glass-forming materials, stress and volume relaxation must be predicted accurately. Although the modeling attributes required to depict physical aging in organic glassy thermosets strongly resemble the structural relaxation in inorganic glasses, the historical modeling approaches have been distinctly different. To determine whether a common constitutive framework can be applied to both classes of materials, the nonlinear viscoelastic simplified potential energy clock (SPEC) model, developed originally for glassy thermosets, was calibrated for the Schott 8061 inorganic glass and used to analyze a number of tests. A practicalmore » methodology for material characterization and model calibration is discussed, and the structural relaxation mechanism is interpreted in the context of SPEC model constitutive equations. SPEC predictions compared to inorganic glass data collected from thermal strain measurements and creep tests demonstrate the ability to achieve engineering accuracy and make the SPEC model feasible for engineering applications involving a much broader class of glassy materials.« less
ERIC Educational Resources Information Center
Thomas, Sally A.
A study was conducted to investigate the impact certain cognitive styles or structures have in mediating the influence of aggressive television on young boys. Ss were 143 white middle class boys: 36 were 5 1/2-year-old kindergarteners; 30 were 6 1/2-year-old first graders; 36 were 7 1/2-year-old second graders; and 41 were 8 1/2-year-old third…
Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J.; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin
2014-01-01
Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha−1 in 1980 to 31.0 Mg ha−1 in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations. PMID:24586881
Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin
2014-01-01
Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha(-1) in 1980 to 31.0 Mg ha(-1) in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations.
Gender and the Construction of Class.
ERIC Educational Resources Information Center
Acker, Joan
Only by recognizing that class is not gender neutral can the processes of class formation and reproduction be understood. Class is defined as a process in which human beings take an active part, rather than a structure of categories into which individuals may be inserted. Gender organizes or structures class in many different ways. For example,…
Krustrup, P; Hansen, P R; Nielsen, C M; Larsen, M N; Randers, M B; Manniche, V; Hansen, L; Dvorak, J; Bangsbo, J
2014-08-01
The present study investigated the cardiac effects of a 10-week football training intervention for school children aged 9-10 years using comprehensive transthoracic echocardiography as a part of a larger ongoing study. A total of 97 pupils from four school classes were cluster-randomized into a control group that maintained their usual activities (CON; two classes, n = 51, 21 boys and 30 girls) and a football training group that performed an additional 3 × 40 min of small-sided football training per week (FT; two classes, n = 46, 23 boys and 23 girls). No baseline differences were observed in age, body composition, or echocardiographic variables between FT and CON. After the 10-week intervention, left ventricular posterior wall diameter was increased in FT compared with CON [0.4 ± 0.7 vs -0.1 ± 0.6 (± SD) mm; P < 0.01] as was the interventricular septum thickness (0.2 ± 0.7 vs -0.2 ± 0.8 mm; P < 0.001). Global isovolumetric relaxation time increased more in FT than in CON (3.8 ± 10.4 vs -0.9 ± 6.6 ms, P < 0.05) while the change in ventricular systolic ejection fraction tended to be higher (1.4 ± 8.0 vs -1.1 ± 5.5%; P = 0.08). No changes were observed in resting heart rate or blood pressure. In conclusion, a short-term, school-based intervention comprising small-sided football sessions resulted in significant structural and functional cardiac adaptations in pre-adolescent children. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Baldi, F; Albuquerque, L G; Alencar, M M
2010-08-01
The objective of this work was to estimate covariance functions for direct and maternal genetic effects, animal and maternal permanent environmental effects, and subsequently, to derive relevant genetic parameters for growth traits in Canchim cattle. Data comprised 49,011 weight records on 2435 females from birth to adult age. The model of analysis included fixed effects of contemporary groups (year and month of birth and at weighing) and age of dam as quadratic covariable. Mean trends were taken into account by a cubic regression on orthogonal polynomials of animal age. Residual variances were allowed to vary and were modelled by a step function with 1, 4 or 11 classes based on animal's age. The model fitting four classes of residual variances was the best. A total of 12 random regression models from second to seventh order were used to model direct and maternal genetic effects, animal and maternal permanent environmental effects. The model with direct and maternal genetic effects, animal and maternal permanent environmental effects fitted by quadric, cubic, quintic and linear Legendre polynomials, respectively, was the most adequate to describe the covariance structure of the data. Estimates of direct and maternal heritability obtained by multi-trait (seven traits) and random regression models were very similar. Selection for higher weight at any age, especially after weaning, will produce an increase in mature cow weight. The possibility to modify the growth curve in Canchim cattle to obtain animals with rapid growth at early ages and moderate to low mature cow weight is limited.
Blomberg, Marie
2011-05-01
To estimate whether weight loss or low gestational weight gain in class I-III obese women is associated with adverse maternal and neonatal outcomes compared with gestational weight gain within the new Institute of Medicine recommendations. This was a population-based cohort study, which included 32,991 obesity class I, 10,068 obesity class II, and 3,536 obesity class III women who were divided into four gestational weight gain categories. Women with low (0-4.9 kg) or no gestational weight gain were compared with women gaining the recommended 5-9 kg concerning obstetric and neonatal outcome after suitable adjustments. Women in obesity class III who lost weight during pregnancy had a decreased risk of cesarean delivery (24.4%; odds ratio [OR] 0.77, 95% confidence interval [CI] 0.60-0.99), large-for-gestational-age births (11.2%, OR 0.64, 95% CI 0.46-0.90), and no significantly increased risk for pre-eclampsia, excessive bleeding during delivery, instrumental delivery, low Apgar score, or fetal distress compared with obese (class III) women gaining within the Institute of Medicine recommendations. There was an increased risk for small for gestational age, 3.7% (OR 2.34, 95% CI 1.15-4.76) among women in obesity class III losing weight, but there was no significantly increased risk of small for gestational age in the same group with low weight gain. Obese women (class II and III) who lose weight during pregnancy seem to have a decreased or unaffected risk for cesarean delivery, large for gestational age, pre-eclampsia, excessive postpartum bleeding, instrumental delivery, low Apgar score, and fetal distress. The twofold increased risk of small for gestational age in obesity class III and weight loss (3.7%) is slightly above the overall prevalence of small-for-gestational-age births in Sweden (3.6%).
Classes of conduct disorder symptoms and their life course correlates in a US national sample.
Breslau, J; Saito, N; Tancredi, D J; Nock, M; Gilman, S E
2012-05-01
Population data on conduct disorder (CD) symptoms can help determine whether hypothesized subtypes of CD are sufficiently disparate in their familial, psychiatric and life course correlates to distinguish separate diagnostic entities. Latent class analysis (LCA) of CD symptoms occurring before age 15 was conducted in a national sample of adults aged 18-44 years from the National Epidemiological Study of Alcohol and Related Conditions. Associations of latent class membership with parental behavior problems, onset of psychiatric disorders and anti-social behaviors after age 15, adolescent life events (e.g. high school drop-out), and past-year life events (e.g. divorce/separation, bankruptcy) were estimated. LCA identified a no-CD class with low prevalence of all symptoms, three intermediate classes - deceit/theft, rule violations, aggression - and a severe class. The prevalence of CD, according to DSM-IV criteria, was 0% in the no-CD class, between 13.33% and 33.69% in the intermediate classes and 62.20% in the severe class. Latent class membership is associated with all the familial, psychiatric and life course outcomes examined. Among the intermediate classes, risk for subsequent mood/anxiety disorders and anti-social behavior was higher in the deceit/theft and aggressive classes than in the rule violations class. However, risk for adolescent life events is highest in the rule violations class. CD symptoms tend to occur in a partially ordered set of classes in the general population. Prognostically meaningful distinctions can be drawn between classes, but only at low levels of symptoms.
Tsakonas, Georgios; Hellman, Fatou; Gubanski, Michael; Friesland, Signe; Tendler, Salomon; Lewensohn, Rolf; Ekman, Simon; de Petris, Luigi
2018-02-01
Whole-brain radiotherapy (WBRT) has been the standard of care for multiple NSCLC brain metastases but due to its toxicity and lack of survival benefit, its use in the palliative setting is being questioned. This was a single institution cohort study including brain metastasized lung cancer patients who received WBRT at Karolinska University Hospital. Information about Recursive Partitioning Analysis (RPA) and Graded Prognostic Assessment (GPA) scores, demographics, histopathological results and received oncological therapy were collected. Predictors of overall survival (OS) from the time of received WBRT were identified by Cox regression analyses. OS between GPA and RPA classes were compared by pairwise log rank test. A subgroup OS analysis was performed stratified by RPA class. The cohort consisted of 280 patients. RPA 1 and 2 classes had better OS compared to class 3, patients with GPA <1.5 points had better OS compared to GPA≥ 1.5 points and age >70 years was associated with worse OS (p< .0001 for all comparisons). In RPA class 2 subgroup analysis GPA ≥1.5 points, age ≤70 years and CNS surgery before salvage WBRT were independent positive prognostic factors. RPA class 3 patients should not receive WBRT, whereas RPA class 1 patients should receive WBRT if clinically indicated. RPA class 2 patients with age ≤70 years and GPA ≥1.5 points should be treated as RPA 1. WBRT should be omitted in RPA 2 patients with age >70. In RPA 2 patients with age ≤70 years and GPA <1.5 points WBRT could be a reasonable option.
D.A. Marquis
1991-01-01
Many studies have shown that initial tree diameter is closely correlated with subsequent tree growth. But initial tree diameter is actually a confounded variable, incorporating both competitive position (crown class) and age.
Family structure and childhood anthropometry in Saint Paul, Minnesota in 1918
Warren, John Robert
2017-01-01
Concern with childhood nutrition prompted numerous surveys of children’s growth in the United States after 1870. The Children’s Bureau’s 1918 “Weighing and Measuring Test” measured two million children to produce the first official American growth norms. Individual data for 14,000 children survives from the Saint Paul, Minnesota survey whose stature closely approximated national norms. As well as anthropometry the survey recorded exact ages, street address and full name. These variables allow linkage to the 1920 census to obtain demographic and socioeconomic information. We matched 72% of children to census families creating a sample of nearly 10,000 children. Children in the entire survey (linked set) averaged 0.74 (0.72) standard deviations below modern WHO height-for-age standards, and 0.48 (0.46) standard deviations below modern weight-for-age norms. Sibship size strongly influenced height-for-age, and had weaker influence on weight-for-age. Each additional child six or underreduced height-for-age scores by 0.07 standard deviations (95% CI: −0.03, 0.11). Teenage siblings had little effect on height-forage. Social class effects were substantial. Children of laborers averaged half a standard deviation shorter than children of professionals. Family structure and socio-economic status had compounding impacts on children’s stature. PMID:28943749
DOE Office of Scientific and Technical Information (OSTI.GOV)
Himanen, J.; Goldgur, Y; Miao, H
2009-01-01
Ephrin (Eph) receptor tyrosine kinases fall into two subclasses (A and B) according to preferences for their ephrin ligands. All published structural studies of Eph receptor/ephrin complexes involve B-class receptors. Here, we present the crystal structures of an A-class complex between EphA2 and ephrin-A1 and of unbound EphA2. Although these structures are similar overall to their B-class counterparts, they reveal important differences that define subclass specificity. The structures suggest that the A-class Eph receptor/ephrin interactions involve smaller rearrangements in the interacting partners, better described by a 'lock-and-key'-type binding mechanism, in contrast to the 'induced fit' mechanism defining the B-class molecules.more » This model is supported by structure-based mutagenesis and by differential requirements for ligand oligomerization by the two subclasses in cell-based Eph receptor activation assays. Finally, the structure of the unligated receptor reveals a homodimer assembly that might represent EphA2-specific homotypic cell adhesion interactions.« less
Bastos, João Luiz; Barros, Aluisio J D; Celeste, Roger Keller; Paradies, Yin; Faerstein, Eduardo
2014-01-01
Although research on discrimination and health has progressed significantly, it has tended to focus on racial discrimination and US populations. This study explored different types of discrimination, their interactions and associations with common mental disorders among Brazilian university students, in Rio de Janeiro in 2010. Associations between discrimination and common mental disorders were examined using multiple logistic regression models, adjusted for confounders. Interactions between discrimination and socio-demographics were tested. Discrimination attributed to age, class and skin color/race were the most frequently reported. In a fully adjusted model, discrimination attributed to skin color/race and class were both independently associated with increased odds of common mental disorders. The simultaneous reporting of skin color/race, class and age discrimination was associated with the highest odds ratio. No significant interactions were found. Skin color/race and class discrimination were important, but their simultaneous reporting, in conjunction with age discrimination, were associated with the highest occurrence of common mental disorders.
ERIC Educational Resources Information Center
Park, Jungkyu; Yu, Hsiu-Ting
2016-01-01
The multilevel latent class model (MLCM) is a multilevel extension of a latent class model (LCM) that is used to analyze nested structure data structure. The nonparametric version of an MLCM assumes a discrete latent variable at a higher-level nesting structure to account for the dependency among observations nested within a higher-level unit. In…
Jay R. Law; Craig G. Lorimer
1989-01-01
Maintaining uneven-aged stands involves cutting trees from a range of diameter classes in such a way that the residual stand has a balanced, steeply descending diameter distribution curve (fig. 1). The objective is to distribute trees by diameter classes so that over time the stand contains trees of different ages and sizes.
Bottomley, Matthew J.; Lo Surdo, Paola; Di Giovine, Paolo; Cirillo, Agostino; Scarpelli, Rita; Ferrigno, Federica; Jones, Philip; Neddermann, Petra; De Francesco, Raffaele; Steinkühler, Christian; Gallinari, Paola; Carfí, Andrea
2008-01-01
Histone deacetylases (HDACs) regulate chromatin status and gene expression, and their inhibition is of significant therapeutic interest. To date, no biological substrate for class IIa HDACs has been identified, and only low activity on acetylated lysines has been demonstrated. Here, we describe inhibitor-bound and inhibitor-free structures of the histone deacetylase-4 catalytic domain (HDAC4cd) and of an HDAC4cd active site mutant with enhanced enzymatic activity toward acetylated lysines. The structures presented, coupled with activity data, provide the molecular basis for the intrinsically low enzymatic activity of class IIa HDACs toward acetylated lysines and reveal active site features that may guide the design of class-specific inhibitors. In addition, these structures reveal a conformationally flexible structural zinc-binding domain conserved in all class IIa enzymes. Importantly, either the mutation of residues coordinating the structural zinc ion or the binding of a class IIa selective inhibitor prevented the association of HDAC4 with the N-CoR·HDAC3 repressor complex. Together, these data suggest a key role of the structural zinc-binding domain in the regulation of class IIa HDAC functions. PMID:18614528
Bottomley, Matthew J; Lo Surdo, Paola; Di Giovine, Paolo; Cirillo, Agostino; Scarpelli, Rita; Ferrigno, Federica; Jones, Philip; Neddermann, Petra; De Francesco, Raffaele; Steinkühler, Christian; Gallinari, Paola; Carfí, Andrea
2008-09-26
Histone deacetylases (HDACs) regulate chromatin status and gene expression, and their inhibition is of significant therapeutic interest. To date, no biological substrate for class IIa HDACs has been identified, and only low activity on acetylated lysines has been demonstrated. Here, we describe inhibitor-bound and inhibitor-free structures of the histone deacetylase-4 catalytic domain (HDAC4cd) and of an HDAC4cd active site mutant with enhanced enzymatic activity toward acetylated lysines. The structures presented, coupled with activity data, provide the molecular basis for the intrinsically low enzymatic activity of class IIa HDACs toward acetylated lysines and reveal active site features that may guide the design of class-specific inhibitors. In addition, these structures reveal a conformationally flexible structural zinc-binding domain conserved in all class IIa enzymes. Importantly, either the mutation of residues coordinating the structural zinc ion or the binding of a class IIa selective inhibitor prevented the association of HDAC4 with the N-CoR.HDAC3 repressor complex. Together, these data suggest a key role of the structural zinc-binding domain in the regulation of class IIa HDAC functions.
Barrett, Dominic A.; Leslie, David M.
2012-01-01
Examination of age structures and sex ratios is useful in the management of northern river otters (Lontra canadensis) and other furbearers. Reintroductions and subsequent recolonizations of river otters have been well documented, but changes in demographics between expanding and established populations have not been observed. As a result of reintroduction efforts, immigration from Arkansas and northeastern Texas, and other efforts, river otters have become partially reestablished throughout eastern and central Oklahoma. Our objective was to examine age structures of river otters in Oklahoma and identify trends that relate to space (watersheds, county) and time (USDA Animal and Plant Health Inspection Service county trapping records). We predicted that river otters in western areas of the state were younger than river otters occurring farther east. From 2005–2007, we obtained salvaged river otter carcasses from federal and state agencies, and we live-captured other river otters using leg hold traps. Seventy-two river otters were sampled. Overall, sex ratios were skewed toward females (1F∶0.8M), but they did not differ among spatiotemporal scales examined. Teeth were removed from salvaged and live-captured river otters (n = 63) for aging. One-year old river otters represented the largest age class (30.2%). Proportion of juveniles (<1 y old) in Oklahoma (19.0%) was less than other states. Mean age of river otters decreased from east-to-west in the Arkansas River and its tributaries. Mean age of river otters differed between the Canadian River Watershed (0.8 y) and the Arkansas River Watershed (2.9 y) and the Canadian River Watershed and the Red River Watershed (2.4 y). Proportion of juveniles did not differ among spatiotemporal scales examined. Similar to age structure variations in other mammalian carnivores, colonizing or growing western populations of river otters in Oklahoma contained younger ages than more established eastern populations.
Growth, Persistence, and Desistance of Alcohol Use for At-Risk Men in Their 30s
Capaldi, Deborah M.; Tiberio, Stacey S.; Washburn, Isaac J.; Yoerger, Karen; Feingold, Alan
2015-01-01
Background Little is known about heterogeneity in men's drinking behaviors and their related consequences across midadulthood, and moreover, whether individual or social factors may predict such differences. The present study examined 3 indicators of alcohol use; namely, alcohol volume, heavy episodic drinking (HED), and drinking-related problems for men in their 30s. Methods Participants were 197 at-risk men from the Oregon Youth Study assessed 5 times across ages 29–38 years. Growth mixture modeling with count outcomes was used to examine unobserved heterogeneity in alcohol trajectories. Associations of latent classes of alcohol users with (i) classes for the other alcohol indicators, (ii) alcohol use by peers and romantic partners, (iii) alcohol classes previously extracted from ages 18–29 years, and (iv) past year alcohol use disorder (AUD) diagnostic status at ages 35–36 years was examined. Results A 3-class solution afforded the best fit for each alcohol indicator. Alcohol problems were relatively established in the 30s, with an ascending use class found only for volume. Although relatively few men were in higher classes for all 3 indicators, 45% of the sample was in the highest class on at least 2 indicators of use. Peer drunkenness was a robust predictor of the alcohol classes. Concordance among classes of alcohol users was seen from the 20s to the 30s, with prior desistance likely to be maintained for alcohol volume and HED. AUD diagnoses at ages 35–36 years were more common in the higher classes obtained for alcohol volume and alcohol problems. Conclusions Many men in their 30s engaged in high volume of alcohol without frequent engagement in HED, likely relating to continuing alcohol problems. The convergence of men's alcohol use with that of their peers found at younger ages was maintained into early midadulthood. PMID:26010338
Barton, Allen W; Brody, Gene H; Zapolski, Tamika C B; Goings, Trenette C; Kogan, Steven M; Windle, Michael; Yu, Tianyi
2018-02-17
To inform research on the etiology and prevention of substance use among rural African American youth by (a) identifying developmental trajectory classes of cannabis use and heavy drinking across adolescence and young adulthood and (b) examining associations between trajectory class membership and multi-level assessments of risk factors. A prospective study spanning 9 years with assessments of cannabis use and heavy drinking, the catecholamines epinephrine and norepinephrine, perceived stress and psychosocial risk factors. Rural communities in the southeastern United States. African American youth (n = 518). Participants were assessed for cannabis use and heavy drinking at seven assessments beginning at 16 years of age and continuing to 25 years of age. At age 19, participants provided overnight urine voids that were assayed for catecholamines, a biological marker of life stress resulting from sympathetic nervous system activation. At ages 16 and 19, participants provided information on malleable psychosocial risk factors. Latent class growth models revealed three distinct trajectory classes for cannabis use and for heavy drinking. Higher levels of circulating stress hormones and perceived stress were associated with classes reporting greater substance use over time (all Ps < 0.05). A composite of selected risk factors discriminated class membership (all Ps < 0.05). Trajectory classes characterized by rapid usage increases in early adulthood exhibited the greatest increase in deviant peer affiliations between ages 16 and 19 years. Rural African American youth's cannabis use and heavy drinking across adolescence and young adulthood demonstrate distinct developmental courses; a small number of risk factors and measures of biological and perceived stress differentiate class membership prognostically. Variability over time in these measures, specifically an increase in deviant peer affiliation, may help to account for steep increases in young adulthood. © 2018 Society for the Study of Addiction.
Skinner, Martie L.; Hong, Seunghye; Herrenkohl, Todd I.; Brown, Eric C.; Lee, Jungeun Olivia; Jung, Hyunzee
2016-01-01
Objective: This study tested a developmental model in which subtypes of childhood maltreatment were hypothesized to have direct and indirect effects on co-occurring depression, anxiety, and substance misuse in adulthood. Indirect effects involved adolescent alcohol use and depression, which were included as mediators in the tested models. Method: This prospective longitudinal study (N = 332; 52.4% male) followed the participants from childhood (18 months to 6 years of age) to adulthood (31–41 years old, M = 36.21). Maltreatment subtypes included parent-reported physical and emotional abuse and child-reported sexual abuse. Adult outcomes included measures of substance misuse and mental health (i.e., depression and anxiety). Latent class analysis and structural equation models were used to identify classes of substance misuse and mental health co-occurrence and to test mediating effects of adolescent alcohol use and depression. Results: Three classes were identified: (a) low risk of substance misuse and low mental health symptoms, (b) moderate substance misuse risk and mild depression and anxiety, and (c) moderate substance misuse risk and moderate to high depression and anxiety. Structural models showed that effects of childhood sexual abuse were fully mediated by adolescent alcohol use and depression. Physical abuse increased adolescent depression but did not have direct or indirect effects on adult outcome classes. Emotional abuse had a direct effect on the adult classes. Conclusions: Children exposed to severe emotional abuse are at higher risk for comorbid substance misuse, depression, and anxiety into their mid-30s, after taking into account evidence of alcohol use and depression during adolescence. Sexual and physical abuse have more proximal effects on adolescent alcohol use and depression, which then influence the risk of adult problems. PMID:27172579
Automated compound classification using a chemical ontology.
Bobach, Claudia; Böhme, Timo; Laube, Ulf; Püschel, Anett; Weber, Lutz
2012-12-29
Classification of chemical compounds into compound classes by using structure derived descriptors is a well-established method to aid the evaluation and abstraction of compound properties in chemical compound databases. MeSH and recently ChEBI are examples of chemical ontologies that provide a hierarchical classification of compounds into general compound classes of biological interest based on their structural as well as property or use features. In these ontologies, compounds have been assigned manually to their respective classes. However, with the ever increasing possibilities to extract new compounds from text documents using name-to-structure tools and considering the large number of compounds deposited in databases, automated and comprehensive chemical classification methods are needed to avoid the error prone and time consuming manual classification of compounds. In the present work we implement principles and methods to construct a chemical ontology of classes that shall support the automated, high-quality compound classification in chemical databases or text documents. While SMARTS expressions have already been used to define chemical structure class concepts, in the present work we have extended the expressive power of such class definitions by expanding their structure-based reasoning logic. Thus, to achieve the required precision and granularity of chemical class definitions, sets of SMARTS class definitions are connected by OR and NOT logical operators. In addition, AND logic has been implemented to allow the concomitant use of flexible atom lists and stereochemistry definitions. The resulting chemical ontology is a multi-hierarchical taxonomy of concept nodes connected by directed, transitive relationships. A proposal for a rule based definition of chemical classes has been made that allows to define chemical compound classes more precisely than before. The proposed structure-based reasoning logic allows to translate chemistry expert knowledge into a computer interpretable form, preventing erroneous compound assignments and allowing automatic compound classification. The automated assignment of compounds in databases, compound structure files or text documents to their related ontology classes is possible through the integration with a chemical structure search engine. As an application example, the annotation of chemical structure files with a prototypic ontology is demonstrated.
Automated compound classification using a chemical ontology
2012-01-01
Background Classification of chemical compounds into compound classes by using structure derived descriptors is a well-established method to aid the evaluation and abstraction of compound properties in chemical compound databases. MeSH and recently ChEBI are examples of chemical ontologies that provide a hierarchical classification of compounds into general compound classes of biological interest based on their structural as well as property or use features. In these ontologies, compounds have been assigned manually to their respective classes. However, with the ever increasing possibilities to extract new compounds from text documents using name-to-structure tools and considering the large number of compounds deposited in databases, automated and comprehensive chemical classification methods are needed to avoid the error prone and time consuming manual classification of compounds. Results In the present work we implement principles and methods to construct a chemical ontology of classes that shall support the automated, high-quality compound classification in chemical databases or text documents. While SMARTS expressions have already been used to define chemical structure class concepts, in the present work we have extended the expressive power of such class definitions by expanding their structure-based reasoning logic. Thus, to achieve the required precision and granularity of chemical class definitions, sets of SMARTS class definitions are connected by OR and NOT logical operators. In addition, AND logic has been implemented to allow the concomitant use of flexible atom lists and stereochemistry definitions. The resulting chemical ontology is a multi-hierarchical taxonomy of concept nodes connected by directed, transitive relationships. Conclusions A proposal for a rule based definition of chemical classes has been made that allows to define chemical compound classes more precisely than before. The proposed structure-based reasoning logic allows to translate chemistry expert knowledge into a computer interpretable form, preventing erroneous compound assignments and allowing automatic compound classification. The automated assignment of compounds in databases, compound structure files or text documents to their related ontology classes is possible through the integration with a chemical structure search engine. As an application example, the annotation of chemical structure files with a prototypic ontology is demonstrated. PMID:23273256
Miao, Ning; Liu, Shi-Rong; Shi, Zuo-Min; Yu, Hong; Liu, Xing-Liang
2009-06-01
Based on the investigation in a 4 hm2 Betula-Abies forest plot in sub-alpine area in West Sichuan of China, and by using point pattern analysis method in terms of O-ring statistics, the spatial patterns of dominant species Betula albo-sinensis and Abies faxoniana in different age classes in study area were analyzed, and the intra- and inter-species associations between these age classes were studied. B. albo-sinensis had a unimodal distribution of its DBH frequency, indicating a declining population, while A. faxoniana had a reverse J-shaped pattern, showing an increasing population. All the big trees of B. albo-sinensis and A. faxoniana were spatially in random at all scales, while the medium age and small trees were spatially clumped at small scales and tended to be randomly or evenly distributed with increasing spatial scale. The maximum aggregation degree decreased with increasing age class. Spatial association mainly occurred at small scales. A. faxoniana generally showed positive intra-specific association, while B. albo-sinensis generally showed negative intra-specific association. For the two populations, big and small trees had no significant spatial association, but middle age trees had negative spatial association. Negative inter-specific associations of the two populations were commonly found in different age classes. The larger the difference of age class, the stronger the negative inter-specific association.
Sustaining corporate class consciousness across the new liquid managerial elite in Britain.
Davis, Aeron
2017-06-01
This article asks: how is class consciousness and cohesiveness amongst the UK business elite maintained in the twenty-first century? Elite studies traditionally sought to account for the construction and circulation of dominant ideology through exclusive education systems, institutional board interlocks and club memberships. The problem is that business elite membership of all these institutions has been steady declining in recent decades. Contemporary corporate elites now appear more mobile and fragmented in an age of globalization. However, class cohesion amongst business leaders appears as strong as ever after decades of neoliberal policy hegemony. So, how are such ideas, norms and values circulated and maintained? This study tried to answer this question drawing on a set of 30 semi-structured interviews with top UK CEOs and a demographic audit of current FTSE 100 CEOs. The findings suggest that three additional means of achieving business elite coherence have become more significant: professional business education, semi-formal but regular meeting sites, and specialist business media. © London School of Economics and Political Science 2017.
Breuer, Thomas; Hockemba, Mireille Breuer-Ndoundou; Olejniczak, Claudia; Parnell, Richard J; Stokes, Emma J
2009-02-01
Physical maturation and life-history parameters are seen as evolutionary adaptations to different ecological and social conditions. Comparison of life-history patterns of closely related species living in diverse environments helps to evaluate the validity of these assumptions but empirical data are lacking. The two gorilla species exhibit substantial differences in their environment, which allows investigation into the role of increased frugivory in shaping western gorilla life histories. We present behavioral and morphological data on western gorilla physical maturation and life-history parameters from a 12.5-year study at Mbeli Bai, a forest clearing in the Nouabalé-Ndoki National Park in northern Congo. We assign photographs of known individuals to different life-history classes and propose new age boundaries for life-history classes in western gorillas, which can be used and tested at other western gorilla research sites. Our results show that western gorillas are weaned at a later age compared with mountain gorillas and indicate slower physical maturation of immatures. These findings support the risk-aversion hypothesis for more frugivorous species. However, our methods need to be applied and tested with other gorilla populations. The slow life histories of western gorillas could have major consequences for social structure, mortality patterns and population growth rates that will affect recovery from population crashes of this critically endangered species. We emphasize that long-term studies can provide crucial demographic and life-history data that improve our understanding of life-history evolution and adaptation and help to refine conservation strategies. (c) 2008 Wiley-Liss, Inc.
Zuidema, Pieter A; Brienen, Roel J W; During, Heinjo J; Güneralp, Burak
2009-11-01
Plants and animals often exhibit strong and persistent growth variation among individuals within a species. Persistently fast-growing individuals have a higher chance of reaching reproductive size, do so at a younger age, and therefore contribute disproportionately to population growth (lambda). Here we introduce a new approach to quantify this "fast-growth effect." We propose using age-size-structured matrix models in which persistently fast and slow growers are distinguished as they occur in relatively young and old age classes for a given size category. Life-cycle pathways involving fast growth can then be identified, and their contribution to lambda is quantified through loop analysis. We applied this approach to an example species, the tropical rainforest tree Cedrela odorata, that shows persistent growth variation among individuals. Loop analysis showed that juvenile trees reaching the 10-cm diameter class at below-median age contributed twice as much to lambda as slow juvenile growers. Fast growth to larger-diameter categories also contributed disproportionately to lambda. The results were robust to changes in parameter values and life-history trade-offs. These results show that the fast-growth effect can be strong in long-lived species. Persistent growth differences among individuals should therefore be accommodated for in demographic models and life-history studies.
Class Inclusion and Role-Taking: Structural Mediation.
ERIC Educational Resources Information Center
Gash, Hugh
The mediational linkage between class inclusion and role-taking skills was investigated by studying the effects of a successive perspective-taking training technique on the consolidation of class inclusion structures. Sixty preoperational Irish boys were given two pretest measures of class inclusion and two of role-taking. They were then grouped…
20 CFR 404.1210 - Optionally excluded services.
Code of Federal Regulations, 2010 CFR
2010-04-01
... Section 404.1210 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND... selectively by coverage groups. They are: (a) Services in any class or classes of elective positions; (b) Services in any class or classes of part-time positions; (c) Services in any class or classes of positions...
Student performance and attitudes in a collaborative and flipped linear algebra course
NASA Astrophysics Data System (ADS)
Murphy, Julia; Chang, Jen-Mei; Suaray, Kagba
2016-07-01
Flipped learning is gaining traction in K-12 for enhancing students' problem-solving skills at an early age; however, there is relatively little large-scale research showing its effectiveness in promoting better learning outcomes in higher education, especially in mathematics classes. In this study, we examined the data compiled from both quantitative and qualitative measures such as item scores on a common final and attitude survey results between a flipped and a traditional Introductory Linear Algebra class taught by two individual instructors at a state university in California in Fall 2013. Students in the flipped class were asked to watch short video lectures made by the instructor and complete a short online quiz prior to each class attendance. The class time was completely devoted to problem solving in group settings where students were prompted to communicate their reasoning with proper mathematical terms and structured sentences verbally and in writing. Examination of the quality and depth of student responses from the common final exam showed that students in the flipped class produced more comprehensive and well-explained responses to the questions that required reasoning, creating examples, and more complex use of mathematical objects. Furthermore, students in the flipped class performed superiorly in the overall comprehension of the content with a 21% increase in the median final exam score. Overall, students felt more confident about their ability to learn mathematics independently, showed better retention of materials over time, and enjoyed the flipped experience.
Öhlén, Joakim; Russell, Lara; Håkanson, Cecilia; Alvariza, Anette; Fürst, Carl Johan; Årestedt, Kristofer; Sawatzky, Richard
2017-01-01
Symptom relief is a key goal of palliative care. There is a need to consider complexities in symptom relief patterns for groups of people to understand and evaluate symptom relief as an indicator of quality of care at end of life. The aims of this study were to distinguish classes of patients who have different symptom relief patterns during the last week of life and to identify predictors of these classes in an adult register population. In a cross-sectional retrospective design, data were used from 87,026 decedents with expected deaths registered in the Swedish Register of Palliative Care in 2011 and 2012. Study variables were structured into patient characteristics, and processes and outcomes of quality of care. A latent class analysis was used to identify symptom relief patterns. Multivariate multinomial regression analyses were used to identify predictors of class membership. Five latent classes were generated: "relieved pain," "relieved pain and rattles," "relieved pain and anxiety," "partly relieved shortness of breath, rattles and anxiety," and "partly relieved pain, anxiety and confusion." Important predictors of class membership were age, sex, cause of death, and having someone present at death, individual prescriptions as needed (PRN) and expert consultations. Interindividual variability and complexity in symptom relief patterns may inform quality of care and its evaluation for dying people across care settings. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.
Fors, Stefan; Lennartsson, Carin; Lundberg, Olle
2011-03-01
The aim of the present study was to investigate the impact of childhood living conditions, marital status, and social class in adulthood on the risk of mortality during mid-life. Two questions were addressed: Is there an effect of childhood living conditions on mortality risk during mid-life and if so, is the effect mediated or modified by social class and/or marital status in adulthood? A nationally representative, Swedish, level of living survey from 1968 was used as baseline. The study included those aged 25-69 at baseline (n = 4082). Social conditions in childhood and adulthood were assessed using self-reports. These individuals were then followed for 39 years using registry data on mortality. The results showed associations between childhood living conditions, marital status, social class in adulthood and mortality during mid life. Social class and familial conditions during childhood as well as marital status and social class in adulthood all contributed to the risk of mortality during mid-life. Individuals whose father's were manual workers, who grew up in broken homes, who were unmarried, and/or were manual workers in adulthood had an increased risk of mortality during mid life. The effects of childhood conditions were, in part, both mediated and modified by social class in adulthood. The findings of this study suggest that there are structural, social conditions experienced at different stages of the life course that affect the risk of mortality during mid-life.
Fesharaki, Nooshin Jafari; Pourghassem, Hossein
2013-07-01
Due to the daily mass production and the widespread variation of medical X-ray images, it is necessary to classify these for searching and retrieving proposes, especially for content-based medical image retrieval systems. In this paper, a medical X-ray image hierarchical classification structure based on a novel merging and splitting scheme and using shape and texture features is proposed. In the first level of the proposed structure, to improve the classification performance, similar classes with regard to shape contents are grouped based on merging measures and shape features into the general overlapped classes. In the next levels of this structure, the overlapped classes split in smaller classes based on the classification performance of combination of shape and texture features or texture features only. Ultimately, in the last levels, this procedure is also continued forming all the classes, separately. Moreover, to optimize the feature vector in the proposed structure, we use orthogonal forward selection algorithm according to Mahalanobis class separability measure as a feature selection and reduction algorithm. In other words, according to the complexity and inter-class distance of each class, a sub-space of the feature space is selected in each level and then a supervised merging and splitting scheme is applied to form the hierarchical classification. The proposed structure is evaluated on a database consisting of 2158 medical X-ray images of 18 classes (IMAGECLEF 2005 database) and accuracy rate of 93.6% in the last level of the hierarchical structure for an 18-class classification problem is obtained.
ERIC Educational Resources Information Center
Meyer, William J.; Goldstein, David
The relative difficulty levels of Stanford-Binet items between the ages of four and six among prekindergarten Head Start children were studied. A comparison sample of prekindergarten white middle class children was included to evaluate the age norms on a culturally typical sample of children and to assess performance on the Binet as it might…
Physical Activity among Men and Women in Midlife: Variations by Class and Employment Status.
ERIC Educational Resources Information Center
Phillips, Mark; Arber, Sarah; Ginn, Jay
2001-01-01
Analysis of data on British midlife adults indicated that being out of the work force between age 50 and state pension age has a different impact on participation in physical activity according to class and gender. Highest levels of inactivity are found among the unemployed working class and relate to low levels of education, poor health, and…
A Way Forward: Nurturing the Imagination at the Intersection of Race, Class, Gender, and Age
ERIC Educational Resources Information Center
Lockhart-Gilroy, Annie A.
2016-01-01
Those who are oppressed often find themselves internalizing voices that limit their ability. This article focuses on a population that falls on the non-hegemonic side of the intersection of race, class, gender, and age: Black girls from poor and working-class backgrounds. From my work with youth, I have noticed that internalizing these limiting…
Allan, Nicholas P; Felton, Julia W; Lejuez, Carl W; MacPherson, Laura; Schmidt, Norman B
2016-05-01
Anxiety sensitivity (AS), the belief that anxious arousal is harmful, is a malleable risk factor that has been implicated in anxiety and depression symptoms in adolescents. Although there is some evidence that adolescents possess distinct developmental trajectories, few studies have explored this topic. This study examined the developmental trajectory of AS in 248 adolescents (M age = 11.0 years, SD = 0.82; 56% male) across 6 years, beginning when children were age 11. This study also examined the influence of AS trajectories on anxiety and depression at age 16. Finally, this study examined the utility of AS classes in identifying anxiety and depression growth. Three AS classes were found, described by normative-stable, high-stable, and high-unstable trajectories. Adolescents in the high-stable and the high-unstable AS classes had higher levels of anxiety and depression at age 16 than did adolescents in the normative-stable AS class. In addition, the anxiety and depression trajectories fit by AS class mirrored the AS class trajectories. These findings suggest three AS trajectories can be identified in adolescents. These trajectories are discussed in relation to a developmental perspective of AS.
Joensuu, Matti; Mattila-Holappa, Pauliina; Ahola, Kirsi; Ervasti, Jenni; Kivimäki, Mika; Kivekäs, Teija; Koskinen, Aki; Vahtera, Jussi; Virtanen, Marianna
2016-02-01
Mental disorders are the leading cause of work disability among young adults. This study examined whether distinct classes could be identified among young adults on the basis of medical history before receiving a disability pension due to a mental disorder. Medical history was obtained from pension applications and attached medical certificates for 1163 individuals aged 18-34 years who, in 2008, received a disability pension due to a mental disorder. Using latent class analysis, 10 clinical and individual adversities and their associations with sex, age and diagnostic category were examined. Three classes were identified: childhood adversity (prevalence, 33%), comorbidity (23%), and undefined (44%). The childhood adversity class was characterized by adverse events and symptoms reported during childhood and it associated with depressive disorders. The comorbidity class was characterized by comorbid mental disorders, suicide attempts and substance abuse and associated with younger age and bipolar disorder. The undefined class formed no distinct profile; individuals in this class had the lowest number of adversities and it associated with psychotic disorders. The identification of subgroups characterized by childhood circumstances and comorbidity may help planning of prevention and support practices for young adults with mental disorders and risk of work disability.
Rhodes, Darson L; Kirchofer, Gregg; Hammig, Bart J; Ogletree, Roberta J
2013-05-01
This study examined the impact of professional preparation and class structure on sexuality topics taught and use of practice-based instructional strategies in US middle and high school health classes. Data from the classroom-level file of the 2006 School Health Policies and Programs were used. A series of multivariable logistic regression models were employed to determine if sexuality content taught was dependent on professional preparation and /or class structure (HE only versus HE/another subject combined). Additional multivariable logistic regression models were employed to determine if use of practice-based instructional strategies was dependent upon professional preparation and/or class structure. Years of teaching health topics and size of the school district were included as covariates in the multivariable logistic regression models. Findings indicated professionally prepared health educators were significantly more likely to teach 7 of the 13 sexuality topics as compared to nonprofessionally prepared health educators. There was no statistically significant difference in the instructional strategies used by professionally prepared and nonprofessionally prepared health educators. Exclusively health education classes versus combined classes were significantly more likely to have included 6 of the 13 topics and to have incorporated practice-based instructional strategies in the curricula. This study indicated professional preparation and class structure impacted sexuality content taught. Class structure also impacted whether opportunities for students to practice skills were made available. Results support the need for continued advocacy for professionally prepared health educators and health only courses. © 2013, American School Health Association.
Rössler, Wulf; AjdacicGross, Vladeta; Glozier, Nick; Rodgers, Stephanie; Haker, Helene; Müller, Mario
2017-10-01
Previous research suggests that sleep disorders are highly associated with other mental health problems. However, sleep problems even below the diagnostic threshold of sleep disorders are very common in the general population, which highly affects wellbeing and functioning. In order to broaden the focus beyond those severe cases we explored empirical patterns across the whole spectrum of sleep problems as well as associated clinical and other factors. A representative community sample of N=1274 residents from the canton of Zurich was interviewed for sleep problems and diagnostic criteria for mental disorders as well as was given a number of mental health-related psychometrical checklists. Based on a broader spectrum of sleep problems we conducted a latent class analysis (LCA) to derive distinct classes of such disturbances. Classes were compared regarding their associations to mental health-relevant and other risk factors. The LCA revealed four classes - no sleep disturbances (72.6%), difficulties initiating and maintaining sleep (15.8%), delayed sleep (5.3%), and severe sleep problems (6.4%). Severe sleep problems were related to female gender and generalized anxiety disorder, while depression was linked to all sleep problem classes. Persons with difficulties initiating and maintaining sleep and severe sleep problems reported higher levels of psychopathology, burnout and neuroticism, while all sleep problem types were tied to stress-related variables, but not alcohol use disorder. Sleep problems are highly prevalent among the young and middle-aged adults in our representative sample of young and middle-aged adults and as such represent a serious public mental health problem. Our findings indicate sleep problems to have a multi-dimensional structure with some differential associations. While all subtypes were associated with poorer mental health and particularly more depression, severe sleep problems appeared to be the sleep subtype seen in agoraphobia and GAD, while delayed sleep had no specific associations. The variety of associations assessed leads one to assume that likewise a variety of sleep interventions is required. Copyright © 2017 Elsevier Inc. All rights reserved.
Demography, life history, and the evolution of age-dependent social behaviour.
Rodrigues, António M M
2018-06-14
Since the inception of modern social evolution theory, a vast majority of studies have sought to explain cooperation using relatedness-driven hypotheses. Natural populations, however, show a substantial amount of variation in social behaviour that is uncorrelated with relatedness. Age offers a major alternative explanation for variation in behaviour that remains unaccounted for. Most natural populations are structured into age-classes, with ageing being a nearly universal feature of most major taxa, including eukaryotic and prokaryotic organisms. Despite this, the theoretical underpinnings of age-dependent social behaviour remain limited. Here, we investigate how group age-composition, demography, and life history shape trajectories of age-dependent behaviours that are expressed conditionally on an actor and recipient's age. We show that demography introduces novel age-dependent selective pressures acting on social phenotypes. Furthermore, we find that life history traits influence the costs and benefits of cooperation directly, but also indirectly. Life history has a strong impact not only on the genetic structure of the population but also on the distribution of group age-compositions, with both of these processes influencing the expression of age-dependent cooperation. Age of peak reproductive performance, in particular, is of chief importance for the evolution of cooperation, as this will largely determine the age and relatedness of social partners. Moreover, our results suggest that later-life reproductive senescence may occur because of demographic effects alone, which opens new vistas on the evolution of menopause and related phenomena. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Dereymaeker, Anneleen; Pillay, Kirubin; Vervisch, Jan; Van Huffel, Sabine; Naulaers, Gunnar; Jansen, Katrien; De Vos, Maarten
2017-09-01
Sleep state development in preterm neonates can provide crucial information regarding functional brain maturation and give insight into neurological well being. However, visual labeling of sleep stages from EEG requires expertise and is very time consuming, prompting the need for an automated procedure. We present a robust method for automated detection of preterm sleep from EEG, over a wide postmenstrual age ([Formula: see text] age) range, focusing first on Quiet Sleep (QS) as an initial marker for sleep assessment. Our algorithm, CLuster-based Adaptive Sleep Staging (CLASS), detects QS if it remains relatively more discontinuous than non-QS over PMA. CLASS was optimized on a training set of 34 recordings aged 27-42 weeks PMA, and performance then assessed on a distinct test set of 55 recordings of the same age range. Results were compared to visual QS labeling from two independent raters (with inter-rater agreement [Formula: see text]), using Sensitivity, Specificity, Detection Factor ([Formula: see text] of visual QS periods correctly detected by CLASS) and Misclassification Factor ([Formula: see text] of CLASS-detected QS periods that are misclassified). CLASS performance proved optimal across recordings at 31-38 weeks (median [Formula: see text], median MF 0-0.25, median Sensitivity 0.93-1.0, and median Specificity 0.80-0.91 across this age range), with minimal misclassifications at 35-36 weeks (median [Formula: see text]). To illustrate the potential of CLASS in facilitating clinical research, normal maturational trends over PMA were derived from CLASS-estimated QS periods, visual QS estimates, and nonstate specific periods (containing QS and non-QS) in the EEG recording. CLASS QS trends agreed with those from visual QS, with both showing stronger correlations than nonstate specific trends. This highlights the benefit of automated QS detection for exploring brain maturation.
Three separate classes of bacterial ice nucleation structures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Turner, M.A.; Arellano, F.; Kozloff, L.M.
1990-05-01
Studies of the properties of the ice nucleation structure exposed on the surfaces of various bacteria such as Pseudomonas syringae, Erwinia herbicola, or various strains of Ice+ recombinant Escherichia coli have shown that there are clearly three major related but chemically distinct types of structures on these cells. First, the ability of Ice+ cells to nucleate super-cooled D2O has been examined, and it has been found that this ability (relative to the ability of the same cells to nucleate super-cooled H2O) exhibited three characteristic nucleating patterns. The rarest structure, called class A, is found on only a small fraction ofmore » cells in a culture, nucleates H2O at temperatures above -4.4 degrees C, and is an effective nucleator of super-cooled D2O. A second class of structure, called class B, is found on a larger portion of the cells, nucleates H2O between -4.8 and -5.7 degrees C, and is a relatively poor nucleator of super-cooled D2O. The class C structure is found on almost all cells and nucleates at -7.6 degrees C or colder. These three classes of structures were also differentiated by their sensitivities to low concentrations of water-miscible organic solvents such as dioxane or dimethyl sulfoxide. Depending on the specific bacterial strain, the addition of these solvents to bacterial suspensions lowered the nucleation activity of the class A structure by 1,000-fold or more. The nucleation activities of class B structures in the same culture were highly resistant to these compounds and were lowered only by 20 to 40%.« less
Effects of lunar phase on sleep in men and women in Surrey.
Della Monica, Ciro; Atzori, Giuseppe; Dijk, Derk-Jan
2015-12-01
Recently, evidence has emerged that the phases of the moon may modulate subjective sleep quality and polysomnographically assessed sleep structure in humans. We aimed to explore further the putative effects of circa-lunar periodicity (~29.5 days) on subjective and objective parameters of human sleep in a retrospective analysis. The baseline sleep recordings of 205 (91 males and 114 females; mean age = 47.47 years, standard deviation =19.01; range: 20-84 years) healthy and carefully screened participants who participated in two clinical trials in the Surrey Clinical Research Centre were included in the analyses. Sleep was recorded in windowless sleep laboratories. For each study night, we calculated the distance, in days, to the date of the closest full moon phase and based on this distance, classified sleep records in three lunar classes. Univariate analysis of variance with factors lunar class, age and sex was applied to each of 21 sleep parameters. No significant main effect for the factor lunar class was observed for any of the objective sleep parameters and subjective sleep quality but some significant interactions were observed. The interaction between lunar class and sex was significant for total sleep time, Stage 4 sleep and rapid eye movement (REM) sleep. Separate analyses for men and women indicated that in women total sleep time, Stage 4 sleep and REM sleep were reduced when sleep occurred close to full moon, whereas in men REM duration increased around full moon. These data provide limited evidence for an effect of lunar phase on human sleep. © 2015 European Sleep Research Society.
ERIC Educational Resources Information Center
Huf, Christina; Raggl, Andrea
2015-01-01
The article synthesises data from two ethnographic projects, which both explore interactions of children in age-mixed groups in primary schools. It illuminates critical perspectives on social orders and children's interactions in age-mixed classes by showing how pupils in age-mixed groups become involved in power relations and how the teacher's…
33 CFR 67.30-1 - Class “C” structures.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Class âCâ structures. 67.30-1 Section 67.30-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âCâ Requirements § 67.30-1...
33 CFR 67.30-1 - Class “C” structures.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Class âCâ structures. 67.30-1 Section 67.30-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âCâ Requirements § 67.30-1...
33 CFR 67.30-1 - Class “C” structures.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Class âCâ structures. 67.30-1 Section 67.30-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âCâ Requirements § 67.30-1...
33 CFR 67.30-1 - Class “C” structures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Class âCâ structures. 67.30-1 Section 67.30-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âCâ Requirements § 67.30-1...
33 CFR 67.30-1 - Class “C” structures.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Class âCâ structures. 67.30-1 Section 67.30-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âCâ Requirements § 67.30-1...
33 CFR 67.20-1 - Class “A” structures.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Class âAâ structures. 67.20-1 Section 67.20-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âAâ Requirements § 67.20-1...
33 CFR 67.20-1 - Class “A” structures.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Class âAâ structures. 67.20-1 Section 67.20-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âAâ Requirements § 67.20-1...
33 CFR 67.20-1 - Class “A” structures.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Class âAâ structures. 67.20-1 Section 67.20-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âAâ Requirements § 67.20-1...
33 CFR 67.20-1 - Class “A” structures.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Class âAâ structures. 67.20-1 Section 67.20-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âAâ Requirements § 67.20-1...
33 CFR 67.25-1 - Class “B” structures.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Class âBâ structures. 67.25-1 Section 67.25-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âBâ Requirements § 67.25-1...
33 CFR 67.20-1 - Class “A” structures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Class âAâ structures. 67.20-1 Section 67.20-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Class âAâ Requirements § 67.20-1...
Tavanti, Michele; Porter, Joanne L; Levy, Colin W; Gómez Castellanos, J Rubén; Flitsch, Sabine L; Turner, Nicholas J
2018-07-02
The first crystal structure of a class VII P450, CYP116B46 from Tepidiphilus thermophilus, has been solved at 1.9 Å resolution. The structure reveals overall conservation of the P450-fold and a water conduit around the I-helix. Active site residues have been identified and sequence comparisons have been made with other class VII enzymes. A structure similarity search demonstrated that the P450-TT structure is similar to enzymes capable of oxy-functionalization of fatty acids, terpenes, macrolides, steroids and statins. The insight gained from solving this structure will provide a guideline for future engineering and modelling studies on this catalytically promiscuous class of enzymes. Copyright © 2018 Elsevier Inc. All rights reserved.
Long-term effects of Class II orthodontic treatment on oral health.
Bock, N C; Saffar, M; Hudel, H; Evälahti, M; Heikinheimo, K; Rice, D P C; Ruf, S
2018-03-01
To investigate the long-term (≥15 years) benefit of orthodontic Class II treatment (Tx) on oral health (OH). All patients (Department of Orthodontics, University of Giessen, Giessen, Germany) who underwent Class II correction (Herbst-multibracket Tx, end of active Tx ≥ 15 years ago) and agreed to participate in a recall (clinical examination, interview, impressions, and photographs) were included. Records after active Tx were used to assess the long-term OH effects. Data were compared to corresponding population-representative age-cohorts as well as to untreated Class I controls without orthodontic Tx need during adolescence. Of 152 treated Class II patients, 75 could be located and agreed to participate at 33.7 ± 3.0 years of age (pre-Tx age: 14.0 ± 2.7 years). The majority (70.8%) were fully satisfied with their teeth and with their masticatory system. The Decayed, Missing, Filled Teeth Index (DMFT) was 7.1 ± 4.8 and, thus, almost identical to that of the untreated Class I controls (7.9 ± 3.6). In contrast, the DMFT in the population-representative age-cohort was 56% higher. The determined mean Community Periodontal Index (CPI) maximum score (1.6 ± 0.6) was also comparable to the untreated Class I controls (1.7 ± 0.9) but in the corresponding population-representative age-cohort it was 19-44% higher. The extent of lower incisor gingival recessions did not differ significantly between the treated Class II participants and the untreated Class I controls (0.1 ± 0.2 vs. 0.0 ± 0.1 mm). Patients with orthodontically treated severe Class II malocclusions had a lower risk for oral health impairment than the general population. The risk corresponded to that of untreated Class I controls (without orthodontic Tx need during adolescence).
Brewer, Shannon K.
2013-01-01
This study examined how spring-flow (SF) contributions to streams related to the distribution and abundance of smallmouth bass Micropterus dolomieu in a predominately pasture landscape in Missouri, USA. Stream segments (N=13) with similar landscape characters were classified by SF volume into high SF (HSF) or low SF (LSF) groups. The densities of smallmouth bass, channel unit (CU) use and temperature-selection patterns were assessed for several life stages and frequency distributions for age 0 fish. More smallmouth bass were present in stream segments with HSF influence. Age 0 fish were twice as likely to be present in HSF stream segments. Older age classes were present in stream reaches independent of SF contribution. For all age classes, the use of particular CUs did not depend on SF influence. All age classes were more likely to be present in pools than other CUs. Microhabitat temperature selection differed among age classes. Age 0 fish selected warmer temperatures with a gradual shift towards cooler temperatures for older age classes. The length frequency of age 0 fish was skewed towards larger individuals in streams with limited SF influence, whereas the length frequency in HSF stream segments was skewed towards smaller individuals. The benefits of significant groundwater via SF influence seem to be related to increased hatch or survival of age 0 fish and the availability of optimal temperatures for adult smallmouth bass growth. Thermal refugia and stable flows provided by springs should be recognised for their biological potential to provide suitable habitat as climate change and other land-use alterations increase temperature regimes and alter flow patterns.
NASA Astrophysics Data System (ADS)
Liang, Yingjie; Chen, Wen
2018-03-01
Ultraslow diffusion has been observed in numerous complicated systems. Its mean squared displacement (MSD) is not a power law function of time, but instead a logarithmic function, and in some cases grows even more slowly than the logarithmic rate. The distributed-order fractional diffusion equation model simply does not work for the general ultraslow diffusion. Recent study has used the local structural derivative to describe ultraslow diffusion dynamics by using the inverse Mittag-Leffler function as the structural function, in which the MSD is a function of inverse Mittag-Leffler function. In this study, a new stretched logarithmic diffusion law and its underlying non-local structural derivative diffusion model are proposed to characterize the ultraslow diffusion in aging dense colloidal glass at both the short and long waiting times. It is observed that the aging dynamics of dense colloids is a class of the stretched logarithmic ultraslow diffusion processes. Compared with the power, the logarithmic, and the inverse Mittag-Leffler diffusion laws, the stretched logarithmic diffusion law has better precision in fitting the MSD of the colloidal particles at high densities. The corresponding non-local structural derivative diffusion equation manifests clear physical mechanism, and its structural function is equivalent to the first-order derivative of the MSD.
Pybus, O G; Perrins, C M; Choudhury, B; Manvell, R J; Nunez, A; Schulenburg, B; Sheldon, B C; Brown, I H
2012-12-01
The first UK epizootic of highly pathogenic (HP) H5N1 influenza in wild birds occurred in 2008, in a population of mute swans that had been the subject of ornithological study for decades. Here we use an innovative combination of ornithological, phylogenetic and immunological approaches to investigate the ecology and age structure of HP H5N1 in nature. We screened samples from swans and waterbirds using PCR and sequenced HP H5N1-positive samples. The outbreak's origin was investigated by linking bird count data with a molecular clock analysis of sampled virus sequences. We used ringing records to reconstruct the age-structure of outbreak mortality, and we estimated the age distribution of prior exposure to avian influenza. Outbreak mortality was low and all HP H5N1-positive mute swans in the affected population were <3 years old. Only the youngest age classes contained an appreciable number of individuals with no detectable antibody responses to viral nucleoprotein. Phylogenetic analysis indicated that the outbreak strain circulated locally for ~1 month before detection and arrived when the immigration rate of migrant waterbirds was highest. Our data are consistent with the hypothesis that HP H5N1 epizootics in wild swans exhibit limited mortality due to immune protection arising from previous exposure. Our study population may represent a valuable resource for investigating the natural ecology and epidemiology of avian influenza.
Ariansen, Anja M S
2014-01-01
Objective Western women increasingly delay having children to advance their career, and pregnancy is considered to be riskier among older women. In Norway, this development surprisingly coincides with increased sickness absence among young pregnant women, rather than their older counterparts. This paper tests the hypothesis that young pregnant women have a higher number of sick days because this age group includes a higher proportion of working class women, who are more prone to sickness absence. Design A zero-inflated Poisson regression was conducted on the Norwegian population registry. Participants All pregnant employees giving birth in 2004–2008 were included in the study. A total number of 216 541 pregnancies were observed among 180 483 women. Outcome measure Number of sick days. Results Although the association between age and number of sick days was U-shaped, pregnant women in their early 20s had a higher number of sick days than those in their mid-40s. This was particularly the case for pregnant women with previous births. In this group, 20-year-olds had 12.6 more sick days than 45-year-olds; this age difference was reduced to 6.3 after control for class. Among women undergoing their first pregnancy, 20-year-olds initially had 1.2 more sick days than 45-year-olds, but control for class altered this age difference. After control for class, 45-year-old first-time pregnant women had 2.9 more sick days than 20-year-olds with corresponding characteristics. Conclusions The negative association between age and sickness absence was partly due to younger age groups including more working class women, who were more prone to sickness absence. Young pregnant women's needs for job adjustments should not be underestimated. PMID:24793246
PreSSAPro: a software for the prediction of secondary structure by amino acid properties.
Costantini, Susan; Colonna, Giovanni; Facchiano, Angelo M
2007-10-01
PreSSAPro is a software, available to the scientific community as a free web service designed to provide predictions of secondary structures starting from the amino acid sequence of a given protein. Predictions are based on our recently published work on the amino acid propensities for secondary structures in either large but not homogeneous protein data sets, as well as in smaller but homogeneous data sets corresponding to protein structural classes, i.e. all-alpha, all-beta, or alpha-beta proteins. Predictions result improved by the use of propensities evaluated for the right protein class. PreSSAPro predicts the secondary structure according to the right protein class, if known, or gives a multiple prediction with reference to the different structural classes. The comparison of these predictions represents a novel tool to evaluate what sequence regions can assume different secondary structures depending on the structural class assignment, in the perspective of identifying proteins able to fold in different conformations. The service is available at the URL http://bioinformatica.isa.cnr.it/PRESSAPRO/.
Revisiting Parametric Types and Virtual Classes
NASA Astrophysics Data System (ADS)
Madsen, Anders Bach; Ernst, Erik
This paper presents a conceptually oriented updated view on the relationship between parametric types and virtual classes. The traditional view is that parametric types excel at structurally oriented composition and decomposition, and virtual classes excel at specifying mutually recursive families of classes whose relationships are preserved in derived families. Conversely, while class families can be specified using a large number of F-bounded type parameters, this approach is complex and fragile; and it is difficult to use traditional virtual classes to specify object composition in a structural manner, because virtual classes are closely tied to nominal typing. This paper adds new insight about the dichotomy between these two approaches; it illustrates how virtual constraints and type refinements, as recently introduced in gbeta and Scala, enable structural treatment of virtual types; finally, it shows how a novel kind of dynamic type check can detect compatibility among entire families of classes.
Nizam, Shadab; Gazara, Rajesh Kumar; Verma, Sandhya; Singh, Kunal; Verma, Praveen Kumar
2014-01-01
Old Yellow Enzyme (OYE1) was the first flavin-dependent enzyme identified and characterized in detail by the entire range of physical techniques. Irrespective of this scrutiny, true physiological role of the enzyme remains a mystery. In a recent study, we systematically identified OYE proteins from various fungi and classified them into three classes viz. Class I, II and III. However, there is no information about the structural organization of Class III OYEs, eukaryotic Class II OYEs and Class I OYEs of filamentous fungi. Ascochyta rabiei, a filamentous phytopathogen which causes Ascochyta blight (AB) in chickpea possesses six OYEs (ArOYE1-6) belonging to the three OYE classes. Here we carried out comparative homology modeling of six ArOYEs representing all the three classes to get an in depth idea of structural and functional aspects of fungal OYEs. The predicted 3D structures of A. rabiei OYEs were refined and evaluated using various validation tools for their structural integrity. Analysis of FMN binding environment of Class III OYE revealed novel residues involved in interaction. The ligand para-hydroxybenzaldehyde (PHB) was docked into the active site of the enzymes and interacting residues were analyzed. We observed a unique active site organization of Class III OYE in comparison to Class I and II OYEs. Subsequently, analysis of stereopreference through structural features of ArOYEs was carried out, suggesting differences in R/S selectivity of these proteins. Therefore, our comparative modeling study provides insights into the FMN binding, active site organization and stereopreference of different classes of ArOYEs and indicates towards functional differences of these enzymes. This study provides the basis for future investigations towards the biochemical and functional characterization of these enigmatic enzymes.
Automatic segmentation of brain MRIs and mapping neuroanatomy across the human lifespan
NASA Astrophysics Data System (ADS)
Keihaninejad, Shiva; Heckemann, Rolf A.; Gousias, Ioannis S.; Rueckert, Daniel; Aljabar, Paul; Hajnal, Joseph V.; Hammers, Alexander
2009-02-01
A robust model for the automatic segmentation of human brain images into anatomically defined regions across the human lifespan would be highly desirable, but such structural segmentations of brain MRI are challenging due to age-related changes. We have developed a new method, based on established algorithms for automatic segmentation of young adults' brains. We used prior information from 30 anatomical atlases, which had been manually segmented into 83 anatomical structures. Target MRIs came from 80 subjects (~12 individuals/decade) from 20 to 90 years, with equal numbers of men, women; data from two different scanners (1.5T, 3T), using the IXI database. Each of the adult atlases was registered to each target MR image. By using additional information from segmentation into tissue classes (GM, WM and CSF) to initialise the warping based on label consistency similarity before feeding this into the previous normalised mutual information non-rigid registration, the registration became robust enough to accommodate atrophy and ventricular enlargement with age. The final segmentation was obtained by combination of the 30 propagated atlases using decision fusion. Kernel smoothing was used for modelling the structural volume changes with aging. Example linear correlation coefficients with age were, for lateral ventricular volume, rmale=0.76, rfemale=0.58 and, for hippocampal volume, rmale=-0.6, rfemale=-0.4 (allρ<0.01).
Custer, Jenny E; Goddard, Bryan D; Matter, Stephen F; Kaneshiro, Edna S
2014-06-01
The oral cariogenic bacterial pathogen Streptococcus mutans strain UA159 has become an important research organism strain since its genome was sequenced. However, there is a paucity of information on its lipidome using direct analytical biochemical approaches. We here report on comprehensive analyses of the major lipid classes and their fatty acids in cells grown in batch standing cultures. Using 2-D high-performance thin-layer chromatography lipid class composition changes were detected with culture age. More lipid components were detected in the stationary-phase compared to log-phase cells. The major lipids identified included 1,3-bis(sn-3'-phosphatidyl)-sn-glycerol (phosphatidylglycerol), 1,3-diphosphatidylglycerol (cardiolipin), aminoacyl-phosphatidylglycerol, monoglucosyldiacylglycerol, diglucosyldiacylglycerol, diglucosylmonoacylglycerol and, glycerophosphoryldiglucosyldiacylglycerol. Culture age also affected the fatty acid composition of the total polar lipid fraction. Thus, the major lipid classes detected in log-phase and stationary-phase cells were isolated and their fatty acids were analyzed by gas-liquid chromatography to determine the basis for the fatty acid compositional changes in the total polar lipid fraction. The analyses showed that the relative proportions of these acids changed with culture age within individual lipid classes. Hence fatty acid changes in the total polar lipid fraction reflected changes in both lipid class composition and fatty acid compositions within individual lipid classes.
Campbell, Susan B.; Morgan-Lopez, Antonio A.; Cox, Martha J.; McLoyd, Vonnie C.
2009-01-01
We used data from the NICHD Study of Early Child Care and Youth Development and latent class analysis to model patterns of maternal depressive symptoms from infant age 1 month to the transition to adolescence (age 12), and then examined adolescent adjustment at age 15 as a function of the course and severity of maternal symptoms. We identified five latent classes of symptoms in these 1357 women while also taking into account sociodemographic measures: never depressed; stable subclinical; early-decreasing; moderately elevated; chronic. Women with few symptoms were more likely to be married, better educated, and in better physical health than women with more elevated symptoms. Family size and whether the pregnancy was planned also differentiated among classes. At age 15, adolescents whose mothers were in the chronic, elevated, and stable subclinical latent classes reported more internalizing and externalizing problems and acknowledged engaging in more risky behavior than did children of never-depressed mothers. Latent class differences in self-reported loneliness and dysphoria were also found. Finally, several significant interactions between sex and latent class suggested that girls whose mothers reported elevated symptoms of depression over time experienced more internalizing distress and dysphoric mood relative to their male counterparts. Discussion focuses on adolescent adjustment, especially among offspring whose mothers report stable symptoms of depression across their childhoods. PMID:19685946
Prevalence of depressive disorders in Rasht, Iran: A community based study.
Modabernia, Mohamad Jafar; Tehrani, Hossein Shodjai; Fallahi, Mahnaz; Shirazi, Maryam; Modabbernia, Amir Hossein
2008-07-04
Depression is a well known health problem worldwide. Prevalence of depressive disorders varies in different societies. to determine the prevalence of depressive disorders and some associated factors in Rasht City (Northern part of Iran). 4020 subjects were selected among 394925 residents of Rasht aged between 18-70 during 2003 - 2004. In the first phase, subjects were screened by Beck's Depression Inventory. In the second phase, those who scored more than 15 were assessed through semi-structured psychiatric interview (DSMIV-TR). Socio-demographic characteristics including age, gender, marital status, educational level, and socio-economic class were recorded as well. 9.5% of samples (63% female and 37% male) were diagnosed by depressive disorders. The prevalence of minor depressive disorder, dysthymia and major depressive disorder was 5%, 2/5%, and 1% respectively. Socio-economic class was significantly associated with both depressive symptoms based on BDI score (p < 0.001) and depressive disorders based on clinical interview (p < 0.001). Comparing to other studies, this study revealed that prevalence of dysthymic and minor depressive disorder were more than major depressive disorder, and low socio-economic class was the most significant risk factor associated with depression. Regarding our study limitations, researchers and policy makers should not consider our findings as conclusive results. Findings of this study could be applied by researchers using analytical methodology to assess relationship between depressive disorders and associated factors.
Elovainio, Marko; Sommerlad, Andrew; Hakulinen, Christian; Pulkki-Råback, Laura; Virtanen, Marianna; Kivimäki, Mika; Singh-Manoux, Archana
2017-11-07
Social relations are important for health, particularly at older ages. We examined the salience of frequency of social contacts and marital status for cognitive ageing trajectories over 21 years, from midlife to early old age. Data are from the Whitehall II cohort study, including 4290 men and 1776 women aged 35-55 years at baseline (1985-88). Frequency of social contacts and marital status were measured in 1985-88 and 1989-90. Assessment of cognitive function on five occasions (1991-94, 1997-99, 2003-04, 2007-09 and 2012-13) included the following tests: short-term memory, inductive reasoning, verbal fluency (phonemic and semantic) and a combined global score. Cognitive trajectories over the study period were analysed using longitudinal latent growth class analyses, and the associations of these latent classes (trajectory memberships) with social relations were analysed using multinominal logistic regression. More frequent social contacts [relative risk (RRR) 0.96, 95% confidence interval (CI) 0.94 - 0.98] and being married (RRR 0.70, 95% CI 0.58 - 0.84) were associated with lower probability of being on a low rather than high cognitive performance trajectory over the subsequent 21 years. These associations persisted after adjustment for covariates. Of the sub-tests, social relations variables had the strongest association with phonemic fluency (RRR 0.95, 95% CI 0.94 - 0.97 for frequent contact; RRR 0.59, 95% CI 0.48 - 0.71 for being married). More frequent social contacts and having a spouse were associated with more favourable cognitive ageing trajectories. Further studies are needed to examine whether interventions designed to improve social connections affect cognitive ageing. © The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association
Protein glycation, diabetes, and aging.
Ulrich, P; Cerami, A
2001-01-01
Biological amines react with reducing sugars to form a complex family of rearranged and dehydrated covalent adducts that are often yellow-brown and/or fluorescent and include many cross-linked structures. Food chemists have long studied this process as a source of flavor, color, and texture changes in cooked, processed, and stored foods. During the 1970s and 1980s, it was realized that this process, called the Maillard reaction or advanced glycation, also occurs slowly in vivo. Advanced glycation endproducts (AGEs) that form are implicated, causing the complications of diabetes and aging, primarily via adventitious and crosslinking of proteins. Long-lived proteins such as structural collagen and lens crystallins particularly are implicated as pathogenic targets of AGE processes. AGE formation in vascular wall collagen appears to be an especially deleterious event, causing crosslinking of collagen molecules to each other and to circulating proteins. This leads to plaque formation, basement membrane thickening, and loss of vascular elasticity. The chemistry of these later-stage, glycation-derived crosslinks is still incompletely understood but, based on the hypothesis that AGE formation involves reactive carbonyl groups, the authors introduced the carbonyl reagent aminoguanidine hydrochloride as an inhibitor of AGE formation in vivo in the mid 1980s. Subsequent studies by many researchers have shown the effectiveness of aminoguanidine in slowing or preventing a wide range of complications of diabetes and aging in animals and, recently, in humans. Since, the authors have developed a new class of agents, exemplified by 4,5-dimethyl-3-phenacylthiazolium chloride (DPTC), which can chemically break already-formed AGE protein-protein crosslinks. These agents are based on a new theory of AGE crosslinking that postulates that alpha-dicarbonyl structures are present in AGE protein-protein crosslinks. In studies in aged animals, DPTC has been shown to be capable of reverting indices of vascular compliance to levels seen in younger animals. Human clinical trials are underway.
Anthropology for the nuclear age
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mandelbaum, D.G.
An anthropological approach to preparing for a turning point in the nuclear age as a result of a large-scale accident or act of terrorism suggests three areas for preliminary study: institutional changes that would reinforce international structures to be more effective in preserving the peace and would redirect military institutions toward that end; cultural changes that would deal with the fears and perceptions of citizens within each nation to find new ways of communication and conflict resolution, but keeping in mind the major class, religious, regional, and ethnic groupings; and global forces that would deal with population pressures. These preliminarymore » studies would need revision after the nuclear event to incorporate the new circumstances. 15 references.« less
Comparing inequalities in women's and men's health: Britain in the 1990s.
Arber, S
1997-03-01
Data on over 20,000 women and men aged 20-59 are analysed from the British General Household Survey for 1991 and 1992, showing the importance of separately analysing educational qualifications, occupational class and employment status for both women and men. Own occupational class and employment status are the key structural factors associated with limiting long-standing illness, but educational qualifications are particularly good predictors of women's self-assessed health. Class inequalities in health are less pronounced among women who are not in paid work. Women's limiting long-standing illness relates solely to their own labour market characteristics, whereas self-assessed health relates to wider aspects of women's everyday lives, including their household material conditions, and for married women, their partner's occupational class and employment status. Men's unemployment has adverse consequences for the health of their wives, which occurs through the mechanism of the family living in disadvantaged material circumstances. Women's labour market position and role in the family have undergone substantial changes since the 1970s. Approaches to measuring inequalities in women's health need to reflect changes in women's employment participation and changes in marital status and living arrangements.
Upper airway changes after Xbow appliance therapy evaluated with cone beam computed tomography.
Erbas, Banu; Kocadereli, Ilken
2014-07-01
To determine the treatment effects of the Xbow appliance on the upper airway dimensions and volume using cone-beam computed tomography (CBCT); to evaluate the cephalometric changes in the skeletal and dental structures of the skeletal Class II patients. The sample consisted of 25 Class II patients (11 male, 14 female) with a mean age of 11.1 ± 1.1 years. CBCT images were obtained at the beginning of the treatment (T0) and after the debonding of the Xbow (T1). Changes in superior, middle, and inferior parts of the oropharynx in the retroglossal region and changes in the oropharyngeal airway volume were statistically significant (P < .05, P < .01). The differences favoring the Xbow for the changes in the direction of Class II correction included SNA, SNB, ANB, maxillary depth angles, and point A-NPg and Co-B distances. Data of the dental parameters showed palatal tipping and extrusion of the maxillary incisors, labial tipping of the mandibular incisors, and mesial movement and extrusion of the mandibular molars. Treatment with the Xbow appliance in Class II patients resulted in favorable increase in the oropharyngeal airway dimensions and volume. Further studies with larger study samples and with control groups are needed.
Bohora, Som; Chaffin, Mark; Shaboltas, Alla; Bonner, Barbara; Isurina, Galina; Batluk, Julia; Bard, David; Tsvetkova, Larissa; Skitnevskaya, Larissa; Volkova, Elena; Balachova, Tatiana
2017-11-01
The number of HIV cases attributed to heterosexual contact and the proportion of women among HIV positive individuals has increased worldwide. Russia is a country with the highest rates of newly diagnosed HIV infections in the region, and the infection spreads beyond traditional risk groups. While young women are affected disproportionately, knowledge of HIV risk behaviors in women in the general population remains limited. The objectives of this study were to identify patterns of behaviors that place women of childbearing age at high risk for HIV transmission and determine whether socio-demographic characteristics and alcohol use are predictive of the risk pattern. A total of 708 non-pregnant women, aged between 18 and 44 years, who were at risk for an alcohol-exposed pregnancy were enrolled in two regions in Russia. Participants completed a structured interview focused on HIV risk behaviors, including risky sexual behavior and alcohol and drug use. Latent class analysis was utilized to examine associations between HIV risk and other demographic and alcohol use characteristics and to identify patterns of risk among women. Three classes were identified. 34.93% of participants were at high risk, combining their risk behaviors, e.g., having multiple sexual partners, with high partner's risk associated with partner's drug use (class I). Despite reporting self-perceived risk for HIV/STI, this class of participants was unlikely to utilize adequate protection (i.e., condom use). The second high risk class included 13.19% of participants who combined their risky sexual behaviors, i.e., multiple sexual partners and having STDs, with partner's risk that included partner's imprisonment and partner's sex with other women (class II). Participants in this class were likely to utilize protection/condoms. Finally, 51.88% of participants were at lower risk, which was associated primarily with their partners' risk, and these participants utilized protection (class III). The odds of being in class I compared with class III were 3.3 (95% CI [1.06, 10.38]) times higher for those women who had Alcohol Use Disorders Identification Test scores ≥ 8 than those who had lower scores, and were 3.9 (95% CI [1.69, 8.97]) times higher for those who used alcohol before sex than those who did not. In addition, women who drank more days per week were 1.36 times more likely to be in class II than in class III. The study informs prevention by identifying specific population groups and targets for interventions. Alcohol use is a significant predictor and an overarching factor of HIV risk in women. Since at-risk drinking is common among young Russian women, alcohol risk reduction should be an essential component of HIV prevention efforts.
Fundamental Principles of Network Formation among Preschool Children1
Schaefer, David R.; Light, John M.; Fabes, Richard A.; Hanish, Laura D.; Martin, Carol Lynn
2009-01-01
The goal of this research was to investigate the origins of social networks by examining the formation of children’s peer relationships in 11 preschool classes throughout the school year. We investigated whether several fundamental processes of relationship formation were evident at this age, including reciprocity, popularity, and triadic closure effects. We expected these mechanisms to change in importance over time as the network crystallizes, allowing more complex structures to evolve from simpler ones in a process we refer to as structural cascading. We analyzed intensive longitudinal observational data of children’s interactions using the SIENA actor-based model. We found evidence that reciprocity, popularity, and triadic closure all shaped the formation of preschool children’s networks. The influence of reciprocity remained consistent, whereas popularity and triadic closure became increasingly important over the course of the school year. Interactions between age and endogenous network effects were nonsignificant, suggesting that these network formation processes were not moderated by age in this sample of young children. We discuss the implications of our longitudinal network approach and findings for the study of early network developmental processes. PMID:20161606
Flexible Organisation of Educational Work in Kindergarten.
ERIC Educational Resources Information Center
Plestenjak, Majda
This study examined the attitudes of 140 children ages 2 through 7 toward mixed-age grouping in a Slovenian kindergarten (preschool) setting. On four consecutive Friday mornings the children, normally grouped in classes aged 2-3 years, 3-4 years, 4-5 years, and 5-7 years, were given the opportunity to switch classes and play among children of…
Structural insights into ligand recognition and selectivity for class A, B, and C GPCRs
Lee, Sang-Min; Booe, Jason M.; Pioszak, Augen A.
2015-01-01
The G protein-coupled receptor (GPCR) superfamily constitutes the largest collection of cell surface signaling proteins with approximately 800 members in the human genome. GPCRs regulate virtually all aspects of physiology and they are an important class of drug targets with ~30% of drugs on the market targeting a GPCR. Breakthroughs in GPCR structural biology in recent years have significantly expanded our understanding of GPCR structure and function and ushered in a new era of structure-based drug design for GPCRs. Crystal structures for nearly thirty distinct GPCRs are now available including receptors from each of the major classes, A, B, C, and F. These structures provide a foundation for understanding the molecular basis of GPCR pharmacology. Here, we review structural mechanisms of ligand recognition and selectivity of GPCRs with a focus on selected examples from classes A, B, and C, and we highlight major unresolved questions for future structural studies. PMID:25981303
Borst, G; Poirel, N; Pineau, A; Cassotti, M; Houdé, O
2013-07-01
Most children under 7 years of age presented with 10 daisies and 2 roses fail to indicate that there are more flowers than daisies. Instead of the appropriate comparison of the relative numerosities of the superordinate class (flowers) to its subordinate class (daisies), they perform a direct perceptual comparison of the extensions of the 2 subordinate classes (daisies vs. roses). In our experiment, we investigated whether increasing efficiency in solving the Piagetian class-inclusion task is related to increasing efficiency in the ability to resist (inhibit) this direct comparison of the subordinate classes' extensions. Ten-year-old and young adult participants performed a computerized priming version of a Piaget-like class-inclusion task. The experimental design was such that the misleading perceptual strategy to inhibit on the prime (in which a superordinate class had to be compared with a subordinate class) became a congruent strategy to activate on the probe (in which the two subordinate classes' extensions were directly compared). We found a negative priming effect of 291 ms in children and 129 ms in adults. These results provide evidence for the first time (a) that adults still need to inhibit the comparison of the subordinate classes' extensions in class-inclusion tasks and (b) that the ability to inhibit this heuristic increases with age (resulting in a lower executive cost). Taken together, these findings provide additional support for the neo-Piagetian approach of cognitive development that suggests that the acquisition of increasingly complex knowledge is based on the ability to resist (inhibit) heuristics and previously acquired knowledge.
Short vs. Long: Cognitive Load, Retention and Changing Class Structures
ERIC Educational Resources Information Center
Sheridan, Brandon; Smith, Ben; Pleggenkuhle-Miles, Erin
2017-01-01
University class structure is changing. To accommodate working students, programmes are increasing their offerings of long night classes--some lasting as long as six hours. While these long classes may be more convenient for students, they have unintended consequences as a result of cognitive load. Using a panel of 124 students (372 observations)…
Factors affecting unintentional harvesting selectivity in a monomorphic species.
Bunnefeld, Nils; Baines, David; Newborn, David; Milner-Gulland, E J
2009-03-01
1. Changes in the abundance of populations have always perplexed ecologists but long-term studies are revealing new insights into population dynamic processes. Long-term data are often derived from harvest records although many wild populations face high harvesting pressures leading to overharvesting and extinction. Additionally, harvest records used to describe population processes such as fluctuations in abundance and reproductive success often assume a random off-take. 2. Selective harvesting based on phenotypic characteristics occurs in many species (e.g. trophy hunting, fisheries) and has important implications for population dynamics, conservation and management. 3. In species with no marked morphological differences between the age and sex classes, such as the red grouse Lagopus lagopus scoticus during the shooting season, hunters cannot consciously select for a specific sex or age class during the shooting process but harvest records could still give a biased reflection of the population structure because of differences in behaviour between age and sex classes. 4. This study compared age and sex ratios in the bag with those in the population before shooting for red grouse at different points in the shooting season and different densities, which has rarely been tested before. 5. More young than old grouse were shot at large bag sizes and vice versa for small bag sizes than would be expected from the population composition before shooting. The susceptibility of old males to shooting compared to females increased with bag size and was high at the first time the area was shot but decreased with the number of times an area was harvested. 6. These findings stress that the assumption made in many studies that harvest records reflect the age and sex ratio of the population and therefore reflect productivity can be misleading. 7. In this paper, as in the literature, it is also shown that number of grouse shot reflects grouse density and therefore that hunting selectivity might influence population dynamics in a cyclic species. 8. The study is not only relevant for red grouse but applies to systems showing interactions between selective harvesting and wider ecological processes, such as age- and sex-related parasitism and territoriality, which may drive population fluctuations.
Spatio-temporal dynamics of pneumonia in bighorn sheep.
Cassirer, E Frances; Plowright, Raina K; Manlove, Kezia R; Cross, Paul C; Dobson, Andrew P; Potter, Kathleen A; Hudson, Peter J
2013-05-01
1. Bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western North America, but management has been constrained by an incomplete understanding of the disease. We analysed patterns of pneumonia-caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes. 2. We observed four age-structured classes of annual pneumonia mortality patterns: all-age, lamb-only, secondary all-age and adult-only. Although there was considerable variability within classes, overall they differed in persistence within and impact on populations. Years with pneumonia-induced mortality occurring simultaneously across age classes (i.e. all-age) appeared to be a consequence of pathogen invasion into a naïve population and resulted in immediate population declines. Subsequently, low recruitment due to frequent high mortality outbreaks in lambs, probably due to association with chronically infected ewes, posed a significant obstacle to population recovery. Secondary all-age events occurred in previously exposed populations when outbreaks in lambs were followed by lower rates of pneumonia-induced mortality in adults. Infrequent pneumonia events restricted to adults were usually of short duration with low mortality. 3. Acute pneumonia-induced mortality in adults was concentrated in fall and early winter around the breeding season when rams are more mobile and the sexes commingle. In contrast, mortality restricted to lambs peaked in summer when ewes and lambs were concentrated in nursery groups. 4. We detected weak synchrony in adult pneumonia between adjacent populations, but found no evidence for landscape-scale extrinsic variables as drivers of disease. 5. We demonstrate that there was a >60% probability of a disease event each year following pneumonia invasion into bighorn sheep populations. Healthy years also occurred periodically, and understanding the factors driving these apparent fade-out events may be the key to managing this disease. Our data and modelling indicate that pneumonia can have greater impacts on bighorn sheep populations than previously reported, and we present hypotheses about processes involved for testing in future investigations and management. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.
NASA Astrophysics Data System (ADS)
Nguyen, B. V.; Challagulla, K. S.; Venkatesh, T. A.; Hadjiloizi, D. A.; Georgiades, A. V.
2016-12-01
Unit-cell based finite element models are developed to completely characterize the role of porosity distribution and porosity volume fraction in determining the elastic, dielectric and piezoelectric properties as well as relevant figures of merit of 3-3 type piezoelectric foam structures. Eight classes of foam structures which represent structures with different types and degrees of uniformity of porosity distribution are identified; a Base structure (Class I), two H-type foam structures (Classes II, and III), a Cross-type foam structure (Class IV) and four Line-type foam structures (Classes V, VI, VII, and VIII). Three geometric factors that influence the electromechanical properties are identified: (i) the number of pores per face, pore size and the distance between the pores; (ii) pore orientation with respect to poling direction; (iii) the overall symmetry of the pore distribution with respect to the center of the face of the unit cell. To assess the suitability of these structures for such applications as hydrophones, bone implants, medical imaging and diagnostic devices, five figures of merit are determined via the developed finite element model; the piezoelectric coupling constant (K t ), the acoustic impedance (Z), the piezoelectric charge coefficient (d h ), the hydrostatic voltage coefficient (g h ), and the hydrostatic figure of merit (d h g h ). At high material volume fractions, foams with non-uniform Line-type porosity (Classes V and VII) where the pores are preferentially distributed perpendicular to poling direction, are found to exhibit the best combination of desirable piezoelectric figures of merit. For example, at about 50% volume fraction, the d h , g h , and d h g h figures of merit are 55%, 1600% and 2500% higher, respectively, for Classes V and VII of Line-like foam structures compared with the Base structure.
Demographic drivers of age-dependent sexual selection.
Martin, A M; Festa-Bianchet, M; Coltman, D W; Pelletier, F
2016-07-01
Sexual selection has a critical role in evolution, and it is fundamental to identify what ecological factors drive its variation. Disentangling the ecological correlates of sexual selection over the long term, however, is challenging and has rarely been done in nature. We sought to assess how demographic changes influenced the intensity, direction and form of sexual selection and whether selective pressures varied with age. We tested whether breeder sex ratio, number of competitors and age structure influenced selection differentials on horn length of wild bighorn rams (Ovis canadensis) of different age classes on Ram Mountain, Alberta. We used 21 years of data including a detailed pedigree, demographic parameters and repeated morphological measurements. Sexual selection on horn length of males of all ages was directional and positive. Selection intensity increased with the number of competitors, reflecting male-male encounter rate during the rut, but was independent of breeder sex ratio or age structure. This result can also be linked to changes in population size because the number of competitors was highly correlated to total number of sheep. This demographic effect likely arises from age-dependent mating tactics. Males aged 2-4 years are weakly competitive and experienced stronger sexual selection as they accounted for a greater proportion of all males. Selection experienced by mature males appeared independent of demography. Our study provides a rare description of the demographic determinants of sexual selection in nature. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.
ERIC Educational Resources Information Center
Borst, G.; Poirel, N.; Pineau, A.; Cassotti, M.; Houdé, O.
2013-01-01
Most children under 7 years of age presented with 10 daisies and 2 roses fail to indicate that there are more flowers than daisies. Instead of the appropriate comparison of the relative numerosities of the superordinate class (flowers) to its subordinate class (daisies), they perform a direct perceptual comparison of the extensions of the 2…
ERIC Educational Resources Information Center
Çetinkaya, Seher
2017-01-01
In Turkey due to changes in the age starting school implemented during the 2012-2013 academic year, children ages from 60 months to 84 months were subject to the same educational program in the same class. By the 2015-2016 academic year these children were at the end of 4th class. This research aimed to investigate the Turkish and mathematic…
Population heterogeneity in trajectories of midlife blood pressure
Wills, Andrew K; Lawlor, Debbie A; Muniz-Terrera, Graciela; Matthews, Fiona; Cooper, Rachel; Ghosh, Arjun K; Kuh, Diana; Hardy, Rebecca
2012-01-01
Background We investigated whether there are subgroups with different underlying (latent) trajectories of midlife systolic blood pressure (BP), diastolic BP and pulse pressure in a UK cohort. Methods Data are from 1840 men and 1819 women with BP measured at age 36, 43 and 53years. We used unconditional growth mixture models to test for the presence of latent trajectory classes. Extracted classes were described in terms of a number of known lifetime risk factors, and linked to the risk of undiagnosed angina (Rose questionnaire) at age 53 years. Results In both sexes for systolic BP, diastolic BP and pulse pressure, there was a large “normative” class (>90% of the sample) characterized by gentle annual increases (eg an increase in male systolic BP of 0.9mmHg/year [95% confidence interval = 0.9 to1.0]), with a smaller class for whom the rate of increase was high (e.g. an increase in male systolic BP of 3.1mmHg/year [2.8 to3.4]). In women there was an additional class for whom BP was high at age 36 and remained high. Persons in the “normative” classes were, on average, heavier at birth and taller at age 7 years, had a lower midlife body mass index, and were less likely to be on antihypertensive medication compared with those in other classes. Among those with no diagnosed cardiovascular disease, those in the classes with more strongly increasing systolic BP and pulse pressure were at greatest risk of angina. Conclusion Our study suggests that in midlife the majority of the population have a gentle underlying increase in BP, but that there also exists an important subgroup in whom BP increases much more markedly. These classes may be useful for identifying those most at risk of cardiovascular disease. PMID:22249241
Brown, J L; Bush, M; Packer, C; Pusey, A E; Monfort, S L; O'Brien, S J; Janssen, D L; Wildt, D E
1991-01-01
Pituitary-gonadal function was examined in male lions free-ranging in the Serengeti Plains or geographically isolated in the Ngorongoro Crater of Tanzania. Lions were classified by age as adult (6.1-9.8 years), young adult (3.3-4.5 years) or prepubertal (1.4-1.6 years, Serengeti Plains only). Each animal was anaesthetized and then bled at 5-min intervals for 100 min before and 140 min after i.v. administration of saline or GnRH (1 micrograms/kg body weight). Basal serum LH and FSH concentrations were similar (P greater than 0.05) among age classes and between locations. In Serengeti Plains lions, net LH peak concentrations after GnRH were approximately 35% greater (P less than 0.05) in prepubertal than in either adult or young adult animals. GnRH-stimulated LH release was similar (P greater than 0.05) between adult and young adult lions, and these responses were similar (P greater than 0.05) to those measured in Ngorongoro Crater lions. Basal and GnRH-stimulated testosterone secretion was higher (P less than 0.05) in adult than in young adult lions and lowest (P less than 0.05) in prepubertal lions. Age-class differences in testosterone production were related directly to the concentrations of LH receptors in the testis (P less than 0.05). Basal and GnRH-stimulated testosterone secretion and gonadotrophin receptor concentrations within age classes were similar (P greater than 0.05) between lions of the Serengeti Plains and Ngorongoro Crater. Lower motility and higher percentages of structurally abnormal spermatozoa were observed in electroejaculates of young adult compared to adult Serengeti Plains males (P less than 0.05) and were associated with decreased steroidogenic activity. In contrast, there were no age-related differences in ejaculate characteristics of Ngorongoro Crater lions. Seminal quality in the Crater population was poor in adult and young adult animals and was unrelated to alterations in pituitary or testicular function. In summary, only seminal quality in adult male lions was affected by location, whereas age significantly affected both basal and GnRH-stimulated testosterone secretion and seminal quality (Serengeti Plains only) in sexually mature males. The striking seminal/endocrine differences among pride (breeding) males of different ages raises questions about the impact of age on individual reproductive performance in this species.
Bergen, Gwen; West, Bethany A; Luo, Feijun; Bird, Donna C; Freund, Katherine; Fortinsky, Richard H; Staplin, Loren
2017-06-01
Motor-vehicle crashes were the second leading cause of injury death for adults aged 65-84years in 2014. Some older drivers choose to self-regulate their driving to maintain mobility while reducing driving risk, yet the process remains poorly understood. Data from 729 older adults (aged ≥60years) who joined an older adult ride service program between April 1, 2010 and November 8, 2013 were analyzed to define and describe classes of driving self-regulation. Latent class analysis was employed to characterize older adult driving self-regulation classes using driving frequency and avoidance of seven driving situations. Logistic regression was used to explore associations between characteristics affecting mobility and self-regulation class. Three classes were identified (low, medium, and high self-regulation). High self-regulating participants reported the highest proportion of always avoiding seven risky driving situations and the lowest driving frequency followed by medium and low self-regulators. Those who were female, aged 80years or older, visually impaired, assistive device users, and those with special health needs were more likely to be high self-regulating compared with low self-regulating. Avoidance of certain driving situations and weekly driving frequency are valid indicators for describing driving self-regulation classes in older adults. Understanding the unique characteristics and mobility limitations of each class can guide optimal transportation strategies for older adults. Published by Elsevier Ltd.
[Change in short-term memory in pupils of 5-7th classes in the process of class work].
Rybakov, V P; Orlova, N I
2014-01-01
The subject of this study was the investigation of the short-term memory (STM) of visual (SVM) and auditory (SAM) modality in boys and girls of the middle school age, as in the daytime, and during the course of the school week. The obtained data show that in pupils from the 5th to the 7th class SVM and SAM playback volume in children of both genders is significantly increased, while SVM productivity in boys from 6 - 7th classes is higher than in girls of the same age. The amplitude of day changes in SVM and SAM was found to decrease significantly with the age. In all age groups the range of daily fluctuations in short-term memory of both modalities in boys appears to be higher than in girls. In all age groups a significant part of schoolchildren was revealed to possess optimal forms of temporal organization of short-term memory: morning, day and morning-day types, in that while during the school week in pupils of 5th to 7th classes of both genders the number of optimal waveforms of curves of daily dynamics of short-term memory increases, which contributes to the optimization of their mental performance.
Mapping a sensory-motor network onto a structural and functional ground plan in the hindbrain.
Koyama, Minoru; Kinkhabwala, Amina; Satou, Chie; Higashijima, Shin-ichi; Fetcho, Joseph
2011-01-18
The hindbrain of larval zebrafish contains a relatively simple ground plan in which the neurons throughout it are arranged into stripes that represent broad neuronal classes that differ in transmitter identity, morphology, and transcription factor expression. Within the stripes, neurons are stacked continuously according to age as well as structural and functional properties, such as axonal extent, input resistance, and the speed at which they are recruited during movements. Here we address the question of how particular networks among the many different sensory-motor networks in hindbrain arise from such an orderly plan. We use a combination of transgenic lines and pairwise patch recording to identify excitatory and inhibitory interneurons in the hindbrain network for escape behaviors initiated by the Mauthner cell. We map this network onto the ground plan to show that an individual hindbrain network is built by drawing components in predictable ways from the underlying broad patterning of cell types stacked within stripes according to their age and structural and functional properties. Many different specialized hindbrain networks may arise similarly from a simple early patterning.
Gubéran, E; Usel, M
1998-12-01
The objective of this retrospective cohort study was to investigate the burden of disability and death in men, from middle age to age of retirement, among occupational groups and classes in Geneva. Men were included if they resided in the Canton of Geneva, were 45 years of age in 1970-1972, and were not receiving a disability pension at the start of the follow-up. The cohort of 5137 men was followed up for 20 years and linked to national registers of disability pension allowance and of causes of death. There was a steep upward trend in incidence of permanent work incapacity with lower social class for all causes as well as for the seven causes of disability studied. Compared with professional occupations (social class I), the relative risk (RR) of permanent work incapacity was 11.4 for partly skilled and unskilled occupations (class IV+V) (95% confidence interval [CI]: 5.2-28.0). The social class gradient in mortality was in the same direction as that in work incapacity although much less steep (RR class IV+V to class I = 1.6, 95% CI : 1.1-2.2). Survival without work incapacity at the time of the 65th birthday ranged from only 57% in construction workers and labourers to 89% in science and related professionals. Unemployment in Geneva was below 1.5% during almost all the study period. Medically-ascertained permanent work incapacity and survival without work incapacity have shown considerably greater socioeconomic differentials than the mortality differentials.
Thin-plate spline analysis of the cranial base in subjects with Class III malocclusion.
Singh, G D; McNamara, J A; Lozanoff, S
1997-08-01
The role of the cranial base in the emergence of Class III malocclusion is not fully understood. This study determines deformations that contribute to a Class III cranial base morphology, employing thin-plate spline analysis on lateral cephalographs. A total of 73 children of European-American descent aged between 5 and 11 years of age with Class III malocclusion were compared with an equivalent group of subjects with a normal, untreated, Class I molar occlusion. The cephalographs were traced, checked and subdivided into seven age- and sex-matched groups. Thirteen points on the cranial base were identified and digitized. The datasets were scaled to an equivalent size, and statistical analysis indicated significant differences between average Class I and Class III cranial base morphologies for each group. Thin-plate spline analysis indicated that both affine (uniform) and non-affine transformations contribute toward the total spline for each average cranial base morphology at each age group analysed. For non-affine transformations, Partial warps 10, 8 and 7 had high magnitudes, indicating large-scale deformations affecting Bolton point, basion, pterygo-maxillare, Ricketts' point and articulare. In contrast, high eigenvalues associated with Partial warps 1-3, indicating localized shape changes, were found at tuberculum sellae, sella, and the frontonasomaxillary suture. It is concluded that large spatial-scale deformations affect the occipital complex of the cranial base and sphenoidal region, in combination with localized distortions at the frontonasal suture. These deformations may contribute to reduced orthocephalization or deficient flattening of the cranial base antero-posteriorly that, in turn, leads to the formation of a Class III malocclusion.
Vogel, Erin R; Alavi, Shauhin E; Utami-Atmoko, Sri Suci; van Noordwijk, Maria A; Bransford, Timothy D; Erb, Wendy M; Zulfa, Astri; Sulistyo, Fransiska; Farida, Wartika Rosa; Rothman, Jessica M
2017-04-01
The spatial and temporal variation in food abundance has strong effects on wildlife feeding and nutrition. This variation is exemplified by the peatland forests of Central Kalimantan, which are characterized by unpredictable fruiting fluctuations, relatively low levels of fruit availability, and low fruit periods (<3% of trees fruiting) that can last nearly a year. Challenged by these environments, large, arboreal frugivores like orangutans must periodically rely on non-preferred, lower-quality foods to meet their nutritional needs. We examined variation in nutrient intake among age-sex classes and seasons over a 7-year period at the Tuanan Orangutan Research Station in Central Kalimantan. We conducted 2,316 full-day focal follows on 62 habituated orangutans (Pongo pygmaeus wurmbii). We found differences in total energy and macronutrient intake across age-sex classes, controlling for metabolic body mass. Intake of both total energy and macronutrients varied with fruit availability, and preference of dietary items increased with their nutritional quality. Foraging-related variables, such as day journey length, travel time, and feeding time, also varied among age-sex classes and with fruit availability. Our results add to the growing body of literature suggesting that great variation in foraging strategies exists among species, populations, and age-sex classes and in response to periods of resource scarcity. The spatial and temporal variation in food abundance has strong effects on wildlife feeding and nutrition. Here we present the first long term study of the effects of variation in fruit availability and age/sex class on nutritional ecology of wild Bornean orangutans. We examined variation in nutrient intake of wild orangutans in living in a peat swamp habitat over a 7-year period at the Tuanan Orangutan Research Station in Central Kalimantan. We conducted 2,316 full-day focal follows on 62 habituated orangutans (Pongo pygmaeus wurmbii). We found differences in total energy and macronutrient intake across age-sex classes, controlling for metabolic body mass. Intake of both total energy and macronutrients varied with fruit availability, and preference of dietary items increased with their nutritional quality. Foraging-related variables, such as day journey length, travel time, and feeding time, also varied among age-sex classes and with fruit availability. Our results add to the growing body of literature suggesting that great variation in foraging strategies exists among species, populations, and age-sex classes and in response to periods of resource scarcity. © 2016 Wiley Periodicals, Inc.
Braga, Heitor O; Azeiteiro, Ulisses M; Oliveira, Henrique M F; Pardal, Miguel A
2017-05-05
European sardines are an important fishing resource in the North Atlantic. Recognized for its great commercial and economic value in southern Europe, this resource currently has low stock indices. From this perspective, fishers' local ecological knowledge (LEK) is appreciated as an auxiliary tool in the management of sardines in this region. Our goal is to evaluate the LEK and attitudes towards the conservation of Sardina pilchardus in the typical fishing village of Peniche, Portugal. From June to September 2016, we carried out 87 semi-structured interviews. The four main points of the interviews were interviewee profile, fishing structure, fishermen's LEK and attitudes towards sardine conservation. The interviews were qualitatively and quantitatively analyzed using a 3-point Likert scale. An LEK index and an attitude index were generated. Comparison analyses and correlations were made between the indices and variables of the interviewee profile and the fishing structure. The mean LEK index was 0.55 and was classified as moderate. The attitudes index in relation to conservation was 0.76 and was classified as positive. This index had a positive and significant correlation with the LEK index and a significant negative correlation with the fishermen's age. When the LEK index was compared with the educational level, significant differences were observed only between class A and class C. The result showed that the differences in the attitudes index were statistically significant when the three educational classes were compared. The fishermen of Peniche in Portugal present moderate informal knowledge about the biology and ecology of sardines. Attitudes towards conservation were predominantly positive. Fishermen with greater LEK, with a higher educational level and at a younger age presented more positive attitudes in relation to environmental conservation issues in the present case of the sardine population. The LEK is not necessarily related to the educational level of the fishermen. We suggest environmental education programs for the communities that depend on this resource. The use of LEK and fishermen's perceptions can help in the management of the European sardine fishery in Portugal.
Boosting structured additive quantile regression for longitudinal childhood obesity data.
Fenske, Nora; Fahrmeir, Ludwig; Hothorn, Torsten; Rzehak, Peter; Höhle, Michael
2013-07-25
Childhood obesity and the investigation of its risk factors has become an important public health issue. Our work is based on and motivated by a German longitudinal study including 2,226 children with up to ten measurements on their body mass index (BMI) and risk factors from birth to the age of 10 years. We introduce boosting of structured additive quantile regression as a novel distribution-free approach for longitudinal quantile regression. The quantile-specific predictors of our model include conventional linear population effects, smooth nonlinear functional effects, varying-coefficient terms, and individual-specific effects, such as intercepts and slopes. Estimation is based on boosting, a computer intensive inference method for highly complex models. We propose a component-wise functional gradient descent boosting algorithm that allows for penalized estimation of the large variety of different effects, particularly leading to individual-specific effects shrunken toward zero. This concept allows us to flexibly estimate the nonlinear age curves of upper quantiles of the BMI distribution, both on population and on individual-specific level, adjusted for further risk factors and to detect age-varying effects of categorical risk factors. Our model approach can be regarded as the quantile regression analog of Gaussian additive mixed models (or structured additive mean regression models), and we compare both model classes with respect to our obesity data.
Relaxation and physical aging in network glasses: a review.
Micoulaut, Matthieu
2016-06-01
Recent progress in the description of glassy relaxation and aging are reviewed for the wide class of network-forming materials such as GeO2, Ge x Se1-x , silicates (SiO2-Na2O) or borates (B2O3-Li2O), all of which have an important usefulness in domestic, geological or optoelectronic applications. A brief introduction of the glass transition phenomenology is given, together with the salient features that are revealed both from theory and experiments. Standard experimental methods used for the characterization of the slowing down of the dynamics are reviewed. We then discuss the important role played by aspects of network topology and rigidity for the understanding of the relaxation of the glass transition, while also permitting analytical predictions of glass properties from simple and insightful models based on the network structure. We also emphasize the great utility of computer simulations which probe the dynamics at the molecular level, and permit the calculation of various structure-related functions in connection with glassy relaxation and the physics of aging which reveal the non-equilibrium nature of glasses. We discuss the notion of spatial variations of structure which leads to the concept of 'dynamic heterogeneities', and recent results in relation to this important topic for network glasses are also reviewed.
Learning Science in Small Multi-Age Groups: The Role of Age Composition
ERIC Educational Resources Information Center
Kallery, Maria; Loupidou, Thomais
2016-01-01
The present study examines how the overall cognitive achievements in science of the younger children in a class where the students work in small multi-age groups are influenced by the number of older children in the groups. The context of the study was early-years education. The study has two parts: The first part involved classes attended by…
ERIC Educational Resources Information Center
Rubin, Mark; Wright, Chrysalis L.
2015-01-01
The present research tested the hypotheses that (a) working-class students have fewer friends at university than middle-class students and (b) this social class difference occurs because working-class students tend to be older than middle-class students. A sample of 376 first-year undergraduate students from an Australian university completed an…
Cofactor specificity motifs and the induced fit mechanism in class I ketol-acid reductoisomerases.
Cahn, Jackson K B; Brinkmann-Chen, Sabine; Spatzal, Thomas; Wiig, Jared A; Buller, Andrew R; Einsle, Oliver; Hu, Yilin; Ribbe, Markus W; Arnold, Frances H
2015-06-15
Although most sequenced members of the industrially important ketol-acid reductoisomerase (KARI) family are class I enzymes, structural studies to date have focused primarily on the class II KARIs, which arose through domain duplication. In the present study, we present five new crystal structures of class I KARIs. These include the first structure of a KARI with a six-residue β2αB (cofactor specificity determining) loop and an NADPH phosphate-binding geometry distinct from that of the seven- and 12-residue loops. We also present the first structures of naturally occurring KARIs that utilize NADH as cofactor. These results show insertions in the specificity loops that confounded previous attempts to classify them according to loop length. Lastly, we explore the conformational changes that occur in class I KARIs upon binding of cofactor and metal ions. The class I KARI structures indicate that the active sites close upon binding NAD(P)H, similar to what is observed in the class II KARIs of rice and spinach and different from the opening of the active site observed in the class II KARI of Escherichia coli. This conformational change involves a decrease in the bending of the helix that runs between the domains and a rearrangement of the nicotinamide-binding site. © The Authors Journal Compilation © 2015 Biochemical Society.
Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases
Haupt, V. Joachim; Schroeder, Michael; Labudde, Dirk
2018-01-01
The origin of the machinery that realizes protein biosynthesis in all organisms is still unclear. One key component of this machinery are aminoacyl tRNA synthetases (aaRS), which ligate tRNAs to amino acids while consuming ATP. Sequence analyses revealed that these enzymes can be divided into two complementary classes. Both classes differ significantly on a sequence and structural level, feature different reaction mechanisms, and occur in diverse oligomerization states. The one unifying aspect of both classes is their function of binding ATP. We identified Backbone Brackets and Arginine Tweezers as most compact ATP binding motifs characteristic for each Class. Geometric analysis shows a structural rearrangement of the Backbone Brackets upon ATP binding, indicating a general mechanism of all Class I structures. Regarding the origin of aaRS, the Rodin-Ohno hypothesis states that the peculiar nature of the two aaRS classes is the result of their primordial forms, called Protozymes, being encoded on opposite strands of the same gene. Backbone Brackets and Arginine Tweezers were traced back to the proposed Protozymes and their more efficient successors, the Urzymes. Both structural motifs can be observed as pairs of residues in contemporary structures and it seems that the time of their addition, indicated by their placement in the ancient aaRS, coincides with the evolutionary trace of Proto- and Urzymes. PMID:29659563
2013-01-01
Background Falls among the elderly are a major public health concern. Therefore, the possibility of a modeling technique which could better estimate fall probability is both timely and needed. Using biomedical, pharmacological and demographic variables as predictors, latent class analysis (LCA) is demonstrated as a tool for the prediction of falls among community dwelling elderly. Methods Using a retrospective data-set a two-step LCA modeling approach was employed. First, we looked for the optimal number of latent classes for the seven medical indicators, along with the patients’ prescription medication and three covariates (age, gender, and number of medications). Second, the appropriate latent class structure, with the covariates, were modeled on the distal outcome (fall/no fall). The default estimator was maximum likelihood with robust standard errors. The Pearson chi-square, likelihood ratio chi-square, BIC, Lo-Mendell-Rubin Adjusted Likelihood Ratio test and the bootstrap likelihood ratio test were used for model comparisons. Results A review of the model fit indices with covariates shows that a six-class solution was preferred. The predictive probability for latent classes ranged from 84% to 97%. Entropy, a measure of classification accuracy, was good at 90%. Specific prescription medications were found to strongly influence group membership. Conclusions In conclusion the LCA method was effective at finding relevant subgroups within a heterogenous at-risk population for falling. This study demonstrated that LCA offers researchers a valuable tool to model medical data. PMID:23705639
Nartey, Richard K; Arntzen, Erik; Fields, Lanny
2015-12-01
In the present study, equivalence class formation was influenced by the temporal point of inclusion of a meaningful stimulus when baseline relations were serially or sequentially trained, and much less so by the location of the meaningful stimulus in the nodal structure of the class. In Experiment 1, participants attempted to form three 3-node, 5-member classes (A→B→C→D→E) under the simultaneous protocol. After serially training the baseline relations AB, BC, CD, and DE, in that order, the emergence of all emergent relations was tested concurrently. In the A-as-PIC condition, A was meaningful stimulus and B to E were meaningless stimulus, and 60 % of the participants formed classes. In addition, classes were formed by 40 %, 70 %, 40 %, and 20 % of the participants in the B-as-PIC, C-as-PIC, D-as-PIC, and E-as-PIC groups, respectively. Thus, the likelihood of class formation could have been influenced by the location of a meaningful stimulus in the class structure and/or by its order of introduction during training. In Experiment 2, we controlled for any effect of order of introduction by the concurrent training of all of the baseline relations. Regardless of the location of the meaningful stimulus, 0-20 % of participants formed classes. Thus, the temporal order of introducing a meaningful stimulus was the primary modulator of the class-enhancing property of meaningful stimuli, and not the location of the meaningful stimulus in the class structure.
Higher stability in forest-atmosphere exchange observed in a structurally diverse forest.
NASA Astrophysics Data System (ADS)
Tamrakar, R.; Rayment, M.; Moyano, F.; Herbst, M.; Mund, M.; Knohl, A.
2016-12-01
We tested the hypothesis that structurally diverse forests have greater stability on exchange processes with the atmosphere compared to forests with less diverse structure. In a case study, we assessed how net ecosystem exchange (NEE) and normalized maximum assimilation (Amax) varied over time in two forests in Germany based on 11 years of continuous eddy flux measurements. The two sites differ in structure as well as in species composition: one (Hainich) is an unmanaged, uneven-aged and heterogeneous mixed beech forest (65% beech), the other (Leinefelde) is a managed, even-aged and homogeneous pure beech stand. The two selected forests are of similar mean ages (about 130 years old) and exposed to similar air temperatures and vapour pressure deficits. Even though Hainich (the unmanaged forest) received higher rainfall (720 ± 134 mm vs 599±166 mm), the soil water availability showed no significant difference between both sites. Based on detailed biomass inventory, trees in Hainich are well distributed in all diameter at breast height (dbh) classes (10 to 90cm dbh) whereas in Leinefelde (the managed forest) trees are mostly confined to dbh classes of 40 to 55 cm. Our results showed a strong difference in inter-annual variability of NEE, which was lower in the unmanaged than in the managed site (coefficient of variation (CV) of 0.13 and 0.27, respectively). The lowest NEE was observed in both sites in 2004, a mast year and a year after the strong summer drought of 2003. The variation in the inter-annual normalized maximum assimilation (Amax) was lower in Hainich (standard deviation of 2.5 compared to 3.9 µmol m-2 s-1). Also, the seasonal course of Amax differed between the two forests which could explain why the mixed forest was more affected by the late summer drought of 2003, despite showing a more conservative carbon budget than the pure stand in the long term. The interannual anomaly in Amax was correlated with fruit production, the latter being larger in Leinefelde (CV of 1.37 vs. 1.18). Our data provide evidence from a case study that exchange processes with the atmosphere are more stable in structurally diverse forests, yet a confirmation covering multiple sites is still pending.
NASA Astrophysics Data System (ADS)
Wilder, T. F.
2013-05-01
Over the past century western United States have experienced drastic anthropogenic land use change from practices such as agriculture, fire exclusion, and timber harvesting. These changes have complex social, cultural, economic, and ecological interactions and consequences. This research studied landscapes patterns of watersheds with similar LANDFIRE potential vegetation in the Southern Washington Cascades physiographic province, within the Yakama Nation Tribal Forest (YTF) and Okanogan-Wenatchee National Forest, Naches Ranger District (NRD). In the selected watersheds, vegetation-mapping units were delineated and populated based on physiognomy of homogeneous areas of vegetative composition and structure using high-resolution aerial photos. Cover types and structural classes were derived from the raw, photo-interpreted vegetation attributes for individual vegetation mapping units and served as individual and composite response variables to quantify and assess spatial patterns and forest health conditions between the two ownerships. Structural classes in both the NRD and YTF were spatially clustered (Z-score 3.1, p-value 0.01; Z-score 2.3, p-value 0.02, respectively), however, ownership and logging type both explained a significant amount of variance in structural class composition. Based on FRAGSTATS landscape metrics, structural classes in the NRD displayed greater clustering and fragmentation with lower interspersion relative to the YTF. The NRD landscape was comprised of 47.4% understory reinitiation structural class type and associated high FRAGASTAT class metrics demonstrated high aggregation with moderate interspersion. Stem exclusion open canopy displayed the greatest dispersal of structural class types throughout the NRD, but adjacencies were correlated to other class types. In the YTF, stem exclusion open canopy comprised 37.7% of the landscape and displayed a high degree of aggregation and interspersion about clusters throughout the YTF. Composite cover type-structural class spatial autocorrelation was clustered in the NRD (Z-score 5.1, p-value 0.01), while the YTF exhibited a random spatial pattern. After accounting for location effects, logging type was the most significant factor explaining variation in composite cover-structure composition. FRAGSTATS landscape metrics identified composite cover-structure classes in the NRD displayed greater aggregation and fragmentation with lower interspersion relative to the YTF. The NRD landscape was comprised of 30.5% Pinus ponderosa-understory reinitiation and associated class metrics demonstrated a high degree of aggregation and fragmentation with low interspersion. Pinus ponderosa-stem exclusion open canopy comprised 24.6% of the YTF landscape and associated class metrics displayed moderate aggregation and fragmentation with high interspersion. A discussion integrating the results and existing relevant literature was indited to assess management regime influences on landscape patterns and, in turn, forest health attributes. This dialog is in provision of enhancing collaboration to optimize forest-health restoration activities across ownerships throughout the study area.
Microbial diversity in Paris polyphylla var. yunnanensis rhizomes of varying ages.
Yang, Y; Yang, S C; Zhao, J; Udikeri, S; Liu, T
2015-12-21
Endophyte microorganisms live inside plants without causing them any apparent damage. Recently, endophytic microorganisms have attracted attention because they can produce bioactive compounds of biotechnological interest. The endophytic microorganisms in Paris polyphylla var. yunnanensis (Liliaceae) - a species used since antiquity in traditional Chinese medicine - are under scrutiny because they may be responsible for producing the bioactive metabolites associated with the plant. The levels of bioactive metabolites in the rhizomes of P. polyphylla increase with rhizome age. To elucidate the roles played by endophytes in the accumulation of bioactive metabolites, we investigated the community structure and diversity of the endophytic microorganisms in P. polyphylla rhizomes of different ages (4, 6, and 8 years) using 16S rRNA and internal transcribed spacer (ITS) sequence analysis. 16S rDNA amplicon pyrosequencing revealed that the number of operational taxonomic units was lower in the 8-year-old samples than in the other samples. A total of 28 phyla were observed in the P. polyphylla samples and the predominant bacteria were of the Cyanobacteria and Proteobacteria phyla. Moreover, the percentage of Cyanobacteria increased with rhizome age. Similarly, ITS1 amplicon pyrosequencing identified developmental changes in the most abundant fungal classes; some classes were more prevalent in the 8-year-old rhizomes than in younger rhizomes, indicating the importance in secondary metabolism in older rhizomes. Our study showed that endophyte microorganism diversity and prevalence depend on P. polyphylla rhizome age. There was also an indication that some endophyte microorganisms contribute to the higher saponin content in older P. polyphylla specimens.
NASA Technical Reports Server (NTRS)
Middleton, Elizabeth M.; Rascher, Uwe; Corp, Lawrence A.; Huemmrich, K. Fred; Cook, Bruce D.; Noormets, Asko; Schickling, Anke; Pinto, Francisco; Alonso, Luis; Damm, Alexander;
2017-01-01
The first European Space Agency (ESA) and NASA collaboration in an airborne campaign to support ESA's FLuorescence EXplorer (FLEX) mission was conducted in North Carolina, USA during September-October 2013 (FLEX-US 2013) at the Parker Tract Loblolly Pine (LP) Plantation (Plymouth, NC, USA). This campaign combined two unique airborne instrument packages to obtain simultaneous observations of solar-induced fluorescence (SIF), LiDAR-based canopy structural information, visible through shortwave infrared (VSWIR) reflectance spectra, and surface temperature, to advance vegetation studies of carbon cycle dynamics and ecosystem health. We obtained statistically significant results for fluorescence, canopy temperature, and tower fluxes from data collected at four times of day over two consecutive autumn days across an age class chronosequence. Both the red fluorescence (F685) and far-red fluorescence (F740) radiances had highest values at mid-day, but their fluorescence yields exhibited different diurnal responses across LP age classes. The diurnal trends for F685 varied with forest canopy temperature difference (canopy minus air), having a stronger daily amplitude change for young vs. old canopies. The Photochemical Reflectance Index (PRI) was positively correlated with this temperature variable over the diurnal cycle. Tower measurements from mature loblolly stand showed the red/far-red fluorescence ratio was linearly related to canopy light use efficiency (LUE) over the diurnal cycle, but performed even better for the combined morning/afternoon (without midday) observations. This study demonstrates the importance of diurnal observations for interpretation of fluorescence dynamics, the need for red fluorescence to understand canopy physiological processes, and the benefits of combining fluorescence, reflectance, and structure information to clarify canopy function versus structure characteristics for a coniferous forest.
NASA Astrophysics Data System (ADS)
Henderson, Jean Foster
The purpose of this study was to assess the effect of classroom restructuring involving computer laboratories on student achievement and student attitudes toward computers and computer courses. The effects of the targeted student attributes of gender, previous programming experience, math background, and learning style were also examined. The open lab-based class structure consisted of a traditional lecture class with a separate, unscheduled lab component in which lab assignments were completed outside of class; the closed lab-based class structure integrated a lab component within the lecture class so that half the class was reserved for lecture and half the class was reserved for students to complete lab assignments by working cooperatively with each other and under the supervision and guidance of the instructor. The sample consisted of 71 students enrolled in four intact classes of Computer Science I during the fall and spring semesters of the 2006--2007 school year at two southern universities: two classes were held in the fall (one at each university) and two classes were held in the spring (one at each university). A counterbalanced repeated measures design was used in which all students experienced both class structures for half of each semester. The order of control and treatment was rotated among the four classes. All students received the same amount of class and instructor time. A multivariate analysis of variance (MANOVA) via a multiple regression strategy was used to test the study's hypotheses. Although the overall MANOVA model was statistically significant, independent follow-up univariate analyses relative to each dependent measure found that the only significant research factor was math background: Students whose mathematics background was at the level of Calculus I or higher had significantly higher student achievement than students whose mathematics background was less than Calculus I. The results suggest that classroom structures that incorporate an open laboratory setting are just as effective on student achievement and attitudes as classroom structures that incorporate a closed laboratory setting. The results also suggest that math background is a strong predictor of student achievement in CS 1.
Lake trout status in the main basin of Lake Huron, 1973-2010
He, Ji X.; Ebener, Mark P.; Riley, Stephen C.; Cottrill, Adam; Kowalski, Adam; Koproski, Scott; Mohr, Lloyd; Johnson, James E.
2012-01-01
We developed indices of lake trout Salvelinus namaycush status in the main basin of Lake Huron (1973-2010) to understand increases in the relative abundance of wild year-classes during 1995-2010. Sea lamprey Petromyzon marinus wounds per 100 lake trout declined from 23.63 in 2000 to 5.86-10.64 in 2002-2010. The average age-7 lake trout catch per effort per recruitment (CPE/R; fish•305mof gill net-1•million stocked yearlings-1) increased from 0.56 for the 1973-1990 year-classes to 0.92 for the 1991-2001 year-classes. Total CPE (fish/305 m of gill net) declined from 16.4 fish in 1996 to 4.1 fish in 2010, but the percentage of age-5 and younger lake trout steadily decreased from more than 70% before 1996 to less than 10% by 2009. The modal age in gill-net catches increased from age 5 before 1996 to age 7 by 2005. The average adult CPE increased from 2.8 fish/305 m of gill net during 1978-1995 to 5.34 fish/305 m of gill net during 1996-2010. The 1995-2010 year-classes of wild fish weremore abundant than previous year-classes and were associated with the relatively high adult abundance during 1996-2010. Until the 2002 year-class, there was no decline in age-7 CPE/R; until 2008, there was no decline in adult CPE. Low survival of the 2002 and 2003 year-classes of stocked fish was related to the event of alewife Alosa pseudoharengus population collapse in 2003-2004. Lake trout in the main basin of Lake Huron are undergoing a transition from a hatchery stock to a wild stock, accompanied by an increased uncertainty in delayed recruitment. Future management should pay more attention to the protection of wild recruitment and the abundance of the spawning stock.
Mota, L F M; Martins, P G M A; Littiere, T O; Abreu, L R A; Silva, M A; Bonafé, C M
2018-04-01
The objective was to estimate (co)variance functions using random regression models (RRM) with Legendre polynomials, B-spline function and multi-trait models aimed at evaluating genetic parameters of growth traits in meat-type quail. A database containing the complete pedigree information of 7000 meat-type quail was utilized. The models included the fixed effects of contemporary group and generation. Direct additive genetic and permanent environmental effects, considered as random, were modeled using B-spline functions considering quadratic and cubic polynomials for each individual segment, and Legendre polynomials for age. Residual variances were grouped in four age classes. Direct additive genetic and permanent environmental effects were modeled using 2 to 4 segments and were modeled by Legendre polynomial with orders of fit ranging from 2 to 4. The model with quadratic B-spline adjustment, using four segments for direct additive genetic and permanent environmental effects, was the most appropriate and parsimonious to describe the covariance structure of the data. The RRM using Legendre polynomials presented an underestimation of the residual variance. Lesser heritability estimates were observed for multi-trait models in comparison with RRM for the evaluated ages. In general, the genetic correlations between measures of BW from hatching to 35 days of age decreased as the range between the evaluated ages increased. Genetic trend for BW was positive and significant along the selection generations. The genetic response to selection for BW in the evaluated ages presented greater values for RRM compared with multi-trait models. In summary, RRM using B-spline functions with four residual variance classes and segments were the best fit for genetic evaluation of growth traits in meat-type quail. In conclusion, RRM should be considered in genetic evaluation of breeding programs.
Voutilainen, Liina; Savola, Sakeri; Kallio, Eva Riikka; Laakkonen, Juha; Vaheri, Antti; Vapalahti, Olli; Henttonen, Heikki
2012-01-01
Intensive management of Fennoscandian forests has led to a mosaic of woodlands in different stages of maturity. The main rodent host of the zoonotic Puumala hantavirus (PUUV) is the bank vole (Myodes glareolus), a species that can be found in all woodlands and especially mature forests. We investigated the influence of forest age structure on PUUV infection dynamics in bank voles. Over four years, we trapped small mammals twice a year in a forest network of different succession stages in Northern Finland. Our study sites represented four forest age classes from young (4 to 30 years) to mature (over 100 years) forests. We show that PUUV-infected bank voles occurred commonly in all forest age classes, but peaked in mature forests. The probability of an individual bank vole to be PUUV infected was positively related to concurrent host population density. However, when population density was controlled for, a relatively higher infection rate was observed in voles trapped in younger forests. Furthermore, we found evidence of a “dilution effect” in that the infection probability was negatively associated with the simultaneous density of other small mammals during the breeding season. Our results suggest that younger forests created by intensive management can reduce hantaviral load in the environment, but PUUV is common in woodlands of all ages. As such, the Fennoscandian forest landscape represents a significant reservoir and source of hantaviral infection in humans. PMID:22745755
Large-scale changes in bloater growth and condition in Lake Huron
Prichard, Carson G.; Roseman, Edward F.; Keeler, Kevin M.; O'Brien, Timothy P.; Riley, Stephen C.
2016-01-01
Native Bloaters Coregonus hoyi have exhibited multiple strong year-classes since 2005 and now are the most abundant benthopelagic offshore prey fish in Lake Huron, following the crash of nonnative AlewivesAlosa pseudoharengus and substantial declines in nonnative Rainbow Smelt Osmerus mordax. Despite recent recoveries in Bloater abundance, marketable-size (>229 mm) Bloaters remain scarce. We used annual survey data to assess temporal and spatial dynamics of Bloater body condition and lengths at age in the main basin of Lake Huron from 1973 to 2014. Basinwide lengths at age were modeled by cohort for the 1973–2003 year-classes using a von Bertalanffy growth model with time-varying Brody growth coefficient (k) and asymptotic length () parameters. Median Bloater weights at selected lengths were estimated to assess changes in condition by modeling weight–length relations with an allometric growth model that allowed growth parameters to vary spatially and temporally. Estimated Bloater lengths at age declined 14–24% among ages 4–8 for all year-classes between 1973 and 2004. Estimates of declined from a peak of 394 mm (1973 year-class) to a minimum of 238 mm (1998 year-class). Observed mean lengths at age in 2014 were at all-time lows, suggesting that year-classes comprising the current Bloater population would have to follow growth trajectories unlike those characterizing the 1973–2003 year-classes to attain marketable size. Furthermore, estimated weights of 250-mm Bloaters (i.e., a large, commercially valuable size-class) declined 17% among all regions from 1976 to 2007. Decreases in body condition of large Bloaters are associated with lower lipid content and may be linked to marked declines in abundance of the amphipodsDiporeia spp. in Lake Huron. We hypothesize that since at least 1976, large Bloaters have become more negatively buoyant and may have incurred an increasingly greater metabolic cost performing diel vertical migrations to prey upon the opossum shrimp Mysis diluviana and zooplankton.
Jaspard, Emmanuel; Macherel, David; Hunault, Gilles
2012-01-01
Late Embryogenesis Abundant Proteins (LEAPs) are ubiquitous proteins expected to play major roles in desiccation tolerance. Little is known about their structure - function relationships because of the scarcity of 3-D structures for LEAPs. The previous building of LEAPdb, a database dedicated to LEAPs from plants and other organisms, led to the classification of 710 LEAPs into 12 non-overlapping classes with distinct properties. Using this resource, numerous physico-chemical properties of LEAPs and amino acid usage by LEAPs have been computed and statistically analyzed, revealing distinctive features for each class. This unprecedented analysis allowed a rigorous characterization of the 12 LEAP classes, which differed also in multiple structural and physico-chemical features. Although most LEAPs can be predicted as intrinsically disordered proteins, the analysis indicates that LEAP class 7 (PF03168) and probably LEAP class 11 (PF04927) are natively folded proteins. This study thus provides a detailed description of the structural properties of this protein family opening the path toward further LEAP structure - function analysis. Finally, since each LEAP class can be clearly characterized by a unique set of physico-chemical properties, this will allow development of software to predict proteins as LEAPs. PMID:22615859
Wodtke, Geoffrey T
2015-12-01
This study investigates changes in the American class structure-defined in terms of workplace ownership and authority relations-and trends in status group disparities in class attainment from 1972 to 2010. Although theory and prior research suggest a variety of appreciable changes in class structure and class attainment, data from the General Social Survey indicate that the sizes of different classes remained fairly stable during this time period and that status group disparities in access to ownership and authority persisted largely intact. The 1970s witnessed a decline in the proportion of workers and growth in the proportion of managers and proprietors, but these trends reversed in the 1980s. As a result, by the late 2000s, the ownership and authority structure of the U.S. economy closely resembled that of the early 1970s. Racial and gender disparities in class attainment also did not change significantly over time: blacks and women remained underrepresented (relative to whites and men) in positions of ownership and authority throughout this period. Even after controlling for an extensive set of human capital characteristics, family constraints, and structural economic factors, there is little evidence of status group integration across these key dimensions of economic power.
Barnett, Lisa M; Ridgers, Nicola D; Zask, Avigdor; Salmon, Jo
2015-01-01
To determine reliability and face validity of an instrument to assess young children's perceived fundamental movement skill competence. Validation and reliability study. A pictorial instrument based on the Test Gross Motor Development-2 assessed perceived locomotor (six skills) and object control (six skills) competence using the format and item structure from the physical competence subscale of the Pictorial Scale of Perceived Competence and Acceptance for Young Children. Sample 1 completed object control items in May (n=32) and locomotor items in October 2012 (n=23) at two time points seven days apart. Children were asked at the end of the test-retest their understanding of what was happening in each picture to determine face validity. Sample 2 (n=58) completed 12 items in November 2012 on a single occasion to test internal reliability only. Sample 1 children were aged 5-7 years (M=6.0, SD=0.8) at object control assessment and 5-8 years at locomotor assessment (M=6.5, SD=0.9). Sample 2 children were aged 6-8 years (M=7.2, SD=0.73). Intra-class correlations assessed in Sample 1 children were excellent for object control (intra-class correlation=0.78), locomotor (intra-class correlation=0.82) and all 12 skills (intra-class correlations=0.83). Face validity was acceptable. Internal consistency was adequate in both samples for each subscale and all 12 skills (alpha range 0.60-0.81). This study has provided preliminary evidence for instrument reliability and face validity. This enables future alignment between the measurement of perceived and actual fundamental movement skill competence in young children. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.
Obesity Cardiometabolic Comorbidity Prevalence in Children in a Rural Weight-Management Program.
O'Hara, Valerie; Browne, Nancy; Fathima, Samreen; Sorondo, Barbara; Bayleran, Janet; Johnston, Starr; Hastey, Kathrin
2017-01-01
This descriptive study examines the prevalence of obesity-related cardiometabolic (CM) risk factors using CM laboratory metrics, in 3 to 19 year olds presenting to a rural American Academy of Pediatrics stage 3 multidisciplinary weight management clinic based on gender, age ranges, and obesity classes. From 2009 to 2016, 382 children (body mass index ≥85th percentile) enrolled. Multiple logistic regression determined the effects of age, gender, or obesity class on CM risk factors. Odds of elevated insulin were more significant in 15 to 19 year olds than in 3 to 5 year olds, or in 6 to 11 year olds. Obesity class III had higher odds than class II, class I, and overweight in having elevated insulin; twice likely than class II for having low high-density lipoprotein; and twice as likely than class I for high triglycerides. Adolescents and obesity class III categories have significant CM risk but the burden in younger and less severe obesity cohorts cannot be underestimated.
Nilsen, Erlend B; Strand, Olav
2018-01-01
We developed a model for estimating demographic rates and population abundance based on multiple data sets revealing information about population age- and sex structure. Such models have previously been described in the literature as change-in-ratio models, but we extend the applicability of the models by i) using time series data allowing the full temporal dynamics to be modelled, by ii) casting the model in an explicit hierarchical modelling framework, and by iii) estimating parameters based on Bayesian inference. Based on sensitivity analyses we conclude that the approach developed here is able to obtain estimates of demographic rate with high precision whenever unbiased data of population structure are available. Our simulations revealed that this was true also when data on population abundance are not available or not included in the modelling framework. Nevertheless, when data on population structure are biased due to different observability of different age- and sex categories this will affect estimates of all demographic rates. Estimates of population size is particularly sensitive to such biases, whereas demographic rates can be relatively precisely estimated even with biased observation data as long as the bias is not severe. We then use the models to estimate demographic rates and population abundance for two Norwegian reindeer (Rangifer tarandus) populations where age-sex data were available for all harvested animals, and where population structure surveys were carried out in early summer (after calving) and late fall (after hunting season), and population size is counted in winter. We found that demographic rates were similar regardless whether we include population count data in the modelling, but that the estimated population size is affected by this decision. This suggest that monitoring programs that focus on population age- and sex structure will benefit from collecting additional data that allow estimation of observability for different age- and sex classes. In addition, our sensitivity analysis suggests that focusing monitoring towards changes in demographic rates might be more feasible than monitoring abundance in many situations where data on population age- and sex structure can be collected.
Fe-12Ni-4Co-2Mo-.05Ti alloy for use at 77°K and below
DOE Office of Scientific and Technical Information (OSTI.GOV)
Whitaker, Bradley Watford
A variant of the maraging class of steels is proposed for application at 77°K and below where a combination of very high strength and good toughness is required. The alloy has a composition of Fe-12Ni-4Co-2Mo-0.05Ti where low interstitial content. The as quenched and quenched and aged structures were completely martensitic with a prior austenitic grain size of 10 to 12 μm. This structure had a Y.S. of 138.5 ksi and 154 ksi before and after aging respectively. All aging was done at 444°C for 4 hours. The DBTT was shown to lie above 77°K as measured by C v testing.more » Based on dilatometric studies of the α $Yields$ γ and γ → α transformation temperatures a cycling treatment consisting of reportedly heating to above the A f temperature followed by a water quench was utilized to further reduce the prior γ grain size to approximately 4 to 6 μm. The structure was completely martensitic and possessed a Y.S. of 151 ksi at 77°K in the unaged condition with a Y.S./K IC ratio of 1.9 while the aged structure showed a Y.S. of 162 ksi with a Y.S./K IC ratio of 1.3. C v testing showed the DBTT to lie between 77°K and 4.2°K. Further grain refinement was accomplished by a 2 phase decomposition procedure which resulted in a grain size of 1 to 2 μm. The structure which contained decreasing amounts of austenite with temperature (3.0 percent at R.T. to 1.0 percent at 4.2°K) showed the best combination of strength and ductility at 4.2°K. A Y.S. of 205 ksi with a Y.S./K IC ratio of 0.84 was achieved before aging. The aged structure was brittle at 4.2°K with a Y.S. of 218 ksi and a Y.S./K IC ratio of 0.425.« less
Changes in occupational class differences in leisure-time physical activity: a follow-up study.
Seiluri, Tina; Lahti, Jouni; Rahkonen, Ossi; Lahelma, Eero; Lallukka, Tea
2011-03-01
Physical activity is known to have health benefits across population groups. However, less is known about changes over time in socioeconomic differences in leisure-time physical activity and the reasons for the changes. We hypothesised that class differences in leisure-time physical activity would widen over time due to declining physical activity among the lower occupational classes. We examined whether occupational class differences in leisure-time physical activity change over time in a cohort of Finnish middle-aged women and men. We also examined whether a set of selected covariates could account for the observed changes. The data were derived from the Helsinki Health Study cohort mail surveys; the respondents were 40-60-year-old employees of the City of Helsinki at baseline in 2000-2002 (n = 8960, response rate 67%). Follow-up questionnaires were sent to the baseline respondents in 2007 (n = 7332, response rate 83%). The outcome measure was leisure-time physical activity, including commuting, converted to metabolic equivalent tasks (MET). Socioeconomic position was measured by occupational class (professionals, semi-professionals, routine non-manual employees and manual workers). The covariates included baseline age, marital status, limiting long-lasting illness, common mental disorders, job strain, physical and mental health functioning, smoking, body mass index, and employment status at follow-up. Firstly the analyses focused on changes over time in age adjusted prevalence of leisure-time physical activity. Secondly, logistic regression analysis was used to adjust for covariates of changes in occupational class differences in leisure-time physical activity. At baseline there were no occupational class differences in leisure-time physical activity. Over the follow-up leisure-time physical activity increased among those in the higher classes and decreased among manual workers, suggesting the emergence of occupational class differences at follow-up. Women in routine non-manual and manual classes and men in the manual class tended to be more often physically inactive in their leisure-time (<14 MET hours/week) and to be less often active (>30 MET hours/week) than those in the top two classes. Adjustment for the covariates did not substantially affect the observed occupational class differences in leisure-time physical activity at follow-up. Occupational class differences in leisure-time physical activity emerged over the follow-up period among both women and men. Leisure-time physical activity needs to be promoted among ageing employees, especially among manual workers.
ERIC Educational Resources Information Center
Ada, Elif Nilay; Cetinkalp, Zisan Kazak; Altiparmak, M. Ersin; Asci, F. Hülya
2018-01-01
The purpose of this study was to determine the role of perceived motivational climate and situational motivation levels on dispositional flow in physical education classes. 242 boys (M[subscript age] = 13.38; SD = 0.95) and 251 girls (M[subscript age] = 13.27; SD = 0.88) a total of 493 secondary school students (M[subscript age] = 13.32; SD =…
ERIC Educational Resources Information Center
Jang, Yuri; Yoon, Hyunwoo; Marti, C. Nathan; Kim, Miyong T.
2015-01-01
Using the translated contents of the National Institute on Aging (NIA)'s Aging IQ, an educational intervention was delivered to older Korean Americans. The educational program was delivered via two different modalities, Internet-based education (n = 12) and in-class education (n = 11), and the overall feasibility and efficacy were evaluated by the…
NASA Astrophysics Data System (ADS)
Petrillo, Marta; Cherubini, Paolo; Fravolini, Giulia; Marchetti, Marco; Ascher-Jenull, Judith; Schärer, Michael; Synal, Hans-Arno; Bertoldi, Daniela; Camin, Federica; Larcher, Roberto; Egli, Markus
2016-03-01
Due to the large size (e.g. sections of tree trunks) and highly heterogeneous spatial distribution of deadwood, the timescales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the chronosequence approach and the five-decay class system that is based on a macromorphological assessment. For the decay classes 1-3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) radiocarbon dating was used. In addition, density, cellulose, and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model, a regression approach, and the stage-based matrix model. In the decay classes 1-3, the ages of the CWD were similar and varied between 1 and 54 years for spruce and 3 and 40 years for larch, with no significant differences between the classes; classes 1-3 are therefore not indicative of deadwood age. This seems to be due to a time lag between the death of a standing tree and its contact with the soil. We found distinct tree-species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were estimated to be in the range 0.018 to 0.022 y-1 for spruce and to about 0.012 y-1 for larch. Snapshot sampling (chronosequences) may overestimate the age and mean residence time of CWD. No sampling bias was, however, detectable using the stage-based matrix model. Cellulose and lignin time trends could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 years for spruce and 50 years for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD. Consequently, the decay of Picea abies and Larix decidua is very low. Several uncertainties, however, remain: 14C dating of CWD from decay classes 4 and 5 and having a pre-bomb age is often difficult (large age range due to methodological constraints) and fall rates of both European larch and Norway spruce are missing.
Lebigre, Christophe; Arcese, Peter; Reid, Jane M
2013-07-01
Age-specific variances and covariances in reproductive success shape the total variance in lifetime reproductive success (LRS), age-specific opportunities for selection, and population demographic variance and effective size. Age-specific (co)variances in reproductive success achieved through different reproductive routes must therefore be quantified to predict population, phenotypic and evolutionary dynamics in age-structured populations. While numerous studies have quantified age-specific variation in mean reproductive success, age-specific variances and covariances in reproductive success, and the contributions of different reproductive routes to these (co)variances, have not been comprehensively quantified in natural populations. We applied 'additive' and 'independent' methods of variance decomposition to complete data describing apparent (social) and realised (genetic) age-specific reproductive success across 11 cohorts of socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia). We thereby quantified age-specific (co)variances in male within-pair and extra-pair reproductive success (WPRS and EPRS) and the contributions of these (co)variances to the total variances in age-specific reproductive success and LRS. 'Additive' decomposition showed that within-age and among-age (co)variances in WPRS across males aged 2-4 years contributed most to the total variance in LRS. Age-specific (co)variances in EPRS contributed relatively little. However, extra-pair reproduction altered age-specific variances in reproductive success relative to the social mating system, and hence altered the relative contributions of age-specific reproductive success to the total variance in LRS. 'Independent' decomposition showed that the (co)variances in age-specific WPRS, EPRS and total reproductive success, and the resulting opportunities for selection, varied substantially across males that survived to each age. Furthermore, extra-pair reproduction increased the variance in age-specific reproductive success relative to the social mating system to a degree that increased across successive age classes. This comprehensive decomposition of the total variances in age-specific reproductive success and LRS into age-specific (co)variances attributable to two reproductive routes showed that within-age and among-age covariances contributed substantially to the total variance and that extra-pair reproduction can alter the (co)variance structure of age-specific reproductive success. Such covariances and impacts should consequently be integrated into theoretical assessments of demographic and evolutionary processes in age-structured populations. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.
McCullough, Michael E; Enders, Craig K; Brion, Sharon L; Jain, Andrea R
2005-07-01
The authors used growth mixture models to study religious development during adulthood (ages 27-80) in a sample of individuals who were identified during childhood as intellectually gifted. The authors identified 3 discrete trajectories of religious development: (a) 40% of participants belonged to a trajectory class characterized by increases in religiousness until midlife and declines in later adulthood; (b) 41% of participants belonged to a trajectory class characterized by very low religiousness in early adulthood and age-related decline; and (c) 19% of participants belonged to a trajectory class characterized by high religiousness in early adulthood and age-related increases. Gender, strength of religious upbringing, number of children, marrying, and agreeableness predicted membership in the trajectory classes. Results were largely consistent with the rational choice theory of religious involvement.
NASA Astrophysics Data System (ADS)
Bauer, J. E.; Canuel, E. A.; McIntosh, H.; Barrett, A.; Ferer, E.; Hossler, K.
2013-12-01
Limited previous studies have shown major differences in the natural 14C and 13C isotopic signatures and radiocarbon ages of different biochemical classes (e.g., proteins, carbohydrates, lipid, etc.) in river, estuarine and marine dissolved and particulate organic matter (DOM and POM, respectively). Of particular note are the much greater radiocarbon ages of lipophilic materials than other compound classes. Possible explanations for these findings include greater-than-expected inputs of fossil and highly aged lipid-containing organic matter to rivers and estuaries, extended sorptive-protection of lipophilic materials from degradation and/or lower overall reactivities of lipids vs. other major biochemical classes. We measured the Delta 14C and del 13C signatures and 14C ages of lipid classes in DOM and POM in a major temperate estuary, Delaware Bay (USA) over two years. Changes in DOM were also followed during large volume dark and light incubations to assess the microbial and photochemical reactivity and processing of DOM and lipids. Neutral lipids in DOM were among the most highly aged (> 30,000 yrs BP) of any materials measured in natural waters to date, and were significantly older than co-occurring polar lipids (~4,000-5,000 yrs BP). In general, DOM lipid ages were significantly greater than POM lipid ages across the river-estuary transect, arguing against sorptive protection as the major factor explaining greater ages of lipid than those of other compound classes. Both dark and light incubations of DOM resulted in losses of very highly aged material (30-50,000 y BP), with the remnant exported lipids being correspondingly younger. The microbial and photochemical alterations were most pronounced for lipids from freshwater reaches of the system (i.e., the Delaware River). These findings suggest that a) dissolved vs. particulate lipids have fundamentally different sources and/or physico-chemical partitioning, b) different lipid classes (e.g., neutral vs. polar) derive from uniquely aged sources and/or are processed at dissimilar rates, and c) biological and photochemical alteration and physical mixing during estuarine transport of DOM and POM can result in significant changes to the composition and ages of the exported materials. The implications of these findings for land-to-ocean fluxes of carbon and organic matter and impacts on oceanic DOM and POM are also examined.
Abu Alhaija, Elham S J; Al-Khateeb, Susan N
2011-05-01
Mild Class III malocciusions can be treated by upper incisor proclination and lower incisor retroclination following extraction of the lower first premolars. To compare the skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances, Class III traction and lower first premolar extractions with the changes in a group of untreated Class III patients. The Treatment group consisted of 30 Class III patients (Mean age 13.69 +/- 1.48 years) who were treated by upper and lower fixed appliances, Class III intermaxillary traction and lower first premolar extractions for 2.88 +/- 1.12 years. The Control group consisted of 20 untreated Class III patients (Mean age 13.51 +/- 0.95) matched for age and gender. The T1 to T2 changes in the treated and untreated groups were compared using a paired t-test while differences between the two groups were compared with an independent t-test. During treatment, the upper incisors were proclined about 1 degree and the lower incisors were retroclined 8 degrees. Small, but statistically significant changes in SNB, Wits and the overlying soft tissues accompanied the changes in incisor inclination. At the end of treatment a positive overbite and overjet were achieved. The increase in lower facial height in the Treatment group was comparable with the change in the Control group. A range of mild to moderate Class III malocclusions can be treated by dentoalveolar compensation.
Social background, bullying, and physical inactivity: National study of 11- to 15-year-olds.
Henriksen, P W; Rayce, S B; Melkevik, O; Due, P; Holstein, B E
2016-10-01
More children from lower social backgrounds are physically inactive than those from higher ones. We studied whether bullying was a mediating factor between lower social background and physical inactivity. We also examined the combined effect of low social class and exposure to bullying on physical inactivity. The Danish sample of the Health Behaviour in School-aged Children (HBSC) study 2006 included 6269 schoolchildren in three age groups: 11-, 13-, and 15-year-olds from a random sample of 80 schools. The students answered the internationally standardized HBSC questionnaire. The applied definition leaves 4.0% in the category physically inactive. The sex and age-adjusted OR (95% CI) for physical inactivity was 2.10 (1.39-3.18) among students with low social class and unclassifiable 3.53 (2.26-5.53). Exposure to bullying was associated with physical inactivity, sex and age-adjusted OR = 2.39 (1.67-3.41). Exposure to bullying did not explain the association between social class and physical inactivity. The association between social class and physical inactivity was more pronounced among participants also exposed to bullying. In conclusion, there was a significantly increased odds ratio for physical inactivity among students from lower social classes and for students exposed to bullying. There was a combined effect of low social class and bullying on physical inactivity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Integrated controls-structures design methodology development for a class of flexible spacecraft
NASA Technical Reports Server (NTRS)
Maghami, P. G.; Joshi, S. M.; Walz, J. E.; Armstrong, E. S.
1990-01-01
Future utilization of space will require large space structures in low-Earth and geostationary orbits. Example missions include: Earth observation systems, personal communication systems, space science missions, space processing facilities, etc., requiring large antennas, platforms, and solar arrays. The dimensions of such structures will range from a few meters to possibly hundreds of meters. For reducing the cost of construction, launching, and operating (e.g., energy required for reboosting and control), it will be necessary to make the structure as light as possible. However, reducing structural mass tends to increase the flexibility which would make it more difficult to control with the specified precision in attitude and shape. Therefore, there is a need to develop a methodology for designing space structures which are optimal with respect to both structural design and control design. In the current spacecraft design practice, it is customary to first perform the structural design and then the controller design. However, the structural design and the control design problems are substantially coupled and must be considered concurrently in order to obtain a truly optimal spacecraft design. For example, let C denote the set of the 'control' design variables (e.g., controller gains), and L the set of the 'structural' design variables (e.g., member sizes). If a structural member thickness is changed, the dynamics would change which would then change the control law and the actuator mass. That would, in turn, change the structural model. Thus, the sets C and L depend on each other. Future space structures can be roughly divided into four mission classes. Class 1 missions include flexible spacecraft with no articulated appendages which require fine attitude pointing and vibration suppression (e.g., large space antennas). Class 2 missions consist of flexible spacecraft with articulated multiple payloads, where the requirement is to fine-point the spacecraft and each individual payload while suppressing the elastic motion. Class 3 missions include rapid slewing of spacecraft without appendages, while Class 4 missions include general nonlinear motion of a flexible spacecraft with articulated appendages and robot arms. Class 1 and 2 missions represent linear mathematical modeling and control system design problems (except for actuator and sensor nonlinearities), while Class 3 and 4 missions represent nonlinear problems. The development of an integrated controls/structures design approach for Class 1 missions is addressed. The performance for these missions is usually specified in terms of (1) root mean square (RMS) pointing errors at different locations on the structure, and (2) the rate of decay of the transient response. Both of these performance measures include the contributions of rigid as well as elastic motion.
Frequency of CPV infection in vaccinated puppies that attended puppy socialization classes.
Stepita, Meredith E; Bain, Melissa J; Kass, Philip H
2013-01-01
Socialization is one method of preventing behavior problems in dogs; however, some oppose socialization before 16 wk of age due to the risk of contracting infectious diseases. The objectives of this study were to determine if puppies that attended puppy socialization classes and were vaccinated by a veterinarian at least once were at an increased risk of confirmed canine parvovirus (CPV) infection compared with puppies that did not attend classes and to determine the frequency of suspected CPV infection in puppies vaccinated at least once that attended classes with trainers. Twenty-one clinics in four cities in the United States provided information regarding demographics, vaccination, CPV diagnosis, and class attendance for puppies ≤ 16 wk of age. In addition, 24 trainers in those same cities collected similar information on puppies that attended their classes. In total, 279 puppies attended socialization classes and none were suspected of or diagnosed with CPV infection. Results indicated that vaccinated puppies attending socialization classes were at no greater risk of CPV infection than vaccinated puppies that did not attend those classes.
Ivanova, A A; Ivanov, A A; Oliferenko, A A; Palyulin, V A; Zefirov, N S
2005-06-01
An improved strategy of quantitative structure-property relationship (QSPR) studies of diverse and inhomogeneous organic datasets has been proposed. A molecular connectivity term was successively corrected for different structural features encoded in fragmental descriptors. The so-called solvation index 1chis (a weighted Randic index) was used as a "leading" variable and standardized molecular fragments were employed as "corrective" class-specific variables. Performance of the new approach was illustrated by modelling a dataset of experimental normal boiling points of 833 organic compounds belonging to 20 structural classes. Firstly, separate QSPR models were derived for each class and for eight groups of structurally similar classes. Finally, a general model formed by combining all the classes together was derived (r2=0.957, s=12.9degreesC). The strategy outlined can find application in QSPR analyses of massive, highly diverse databases of organic compounds.
Measurement and Structural Model Class Separation in Mixture CFA: ML/EM versus MCMC
ERIC Educational Resources Information Center
Depaoli, Sarah
2012-01-01
Parameter recovery was assessed within mixture confirmatory factor analysis across multiple estimator conditions under different simulated levels of mixture class separation. Mixture class separation was defined in the measurement model (through factor loadings) and the structural model (through factor variances). Maximum likelihood (ML) via the…
Kurgan, Lukasz; Cios, Krzysztof; Chen, Ke
2008-05-01
Protein structure prediction methods provide accurate results when a homologous protein is predicted, while poorer predictions are obtained in the absence of homologous templates. However, some protein chains that share twilight-zone pairwise identity can form similar folds and thus determining structural similarity without the sequence similarity would be desirable for the structure prediction. The folding type of a protein or its domain is defined as the structural class. Current structural class prediction methods that predict the four structural classes defined in SCOP provide up to 63% accuracy for the datasets in which sequence identity of any pair of sequences belongs to the twilight-zone. We propose SCPRED method that improves prediction accuracy for sequences that share twilight-zone pairwise similarity with sequences used for the prediction. SCPRED uses a support vector machine classifier that takes several custom-designed features as its input to predict the structural classes. Based on extensive design that considers over 2300 index-, composition- and physicochemical properties-based features along with features based on the predicted secondary structure and content, the classifier's input includes 8 features based on information extracted from the secondary structure predicted with PSI-PRED and one feature computed from the sequence. Tests performed with datasets of 1673 protein chains, in which any pair of sequences shares twilight-zone similarity, show that SCPRED obtains 80.3% accuracy when predicting the four SCOP-defined structural classes, which is superior when compared with over a dozen recent competing methods that are based on support vector machine, logistic regression, and ensemble of classifiers predictors. The SCPRED can accurately find similar structures for sequences that share low identity with sequence used for the prediction. The high predictive accuracy achieved by SCPRED is attributed to the design of the features, which are capable of separating the structural classes in spite of their low dimensionality. We also demonstrate that the SCPRED's predictions can be successfully used as a post-processing filter to improve performance of modern fold classification methods.
Kurgan, Lukasz; Cios, Krzysztof; Chen, Ke
2008-01-01
Background Protein structure prediction methods provide accurate results when a homologous protein is predicted, while poorer predictions are obtained in the absence of homologous templates. However, some protein chains that share twilight-zone pairwise identity can form similar folds and thus determining structural similarity without the sequence similarity would be desirable for the structure prediction. The folding type of a protein or its domain is defined as the structural class. Current structural class prediction methods that predict the four structural classes defined in SCOP provide up to 63% accuracy for the datasets in which sequence identity of any pair of sequences belongs to the twilight-zone. We propose SCPRED method that improves prediction accuracy for sequences that share twilight-zone pairwise similarity with sequences used for the prediction. Results SCPRED uses a support vector machine classifier that takes several custom-designed features as its input to predict the structural classes. Based on extensive design that considers over 2300 index-, composition- and physicochemical properties-based features along with features based on the predicted secondary structure and content, the classifier's input includes 8 features based on information extracted from the secondary structure predicted with PSI-PRED and one feature computed from the sequence. Tests performed with datasets of 1673 protein chains, in which any pair of sequences shares twilight-zone similarity, show that SCPRED obtains 80.3% accuracy when predicting the four SCOP-defined structural classes, which is superior when compared with over a dozen recent competing methods that are based on support vector machine, logistic regression, and ensemble of classifiers predictors. Conclusion The SCPRED can accurately find similar structures for sequences that share low identity with sequence used for the prediction. The high predictive accuracy achieved by SCPRED is attributed to the design of the features, which are capable of separating the structural classes in spite of their low dimensionality. We also demonstrate that the SCPRED's predictions can be successfully used as a post-processing filter to improve performance of modern fold classification methods. PMID:18452616
Dynamic analysis of a hepatitis B model with three-age-classes
NASA Astrophysics Data System (ADS)
Zhang, Suxia; Zhou, Yicang
2014-07-01
Based on the fact that the likelihood of becoming chronically infected is dependent on age at primary infection Kane (1995) [2], Edmunds et al. (1993) [3], Medley et al. (2001) [4], and Ganem and Prince (2004) [6], we formulate a hepatitis B transmission model with three age classes. The reproduction number, R0 is defined and the dynamical behavior of the model is analyzed. It is proved that the disease-free equilibrium is globally stable if R0<1, and there exists at least one endemic equilibrium and that the disease is uniformly persistent if R0>1. The unique endemic equilibrium and its global stability is obtained in a special case. Simulations are also conducted to compare the dynamical behavior of the model with and without age classes.
Age- and sex-specific mortality and population structure in sea otters
Bodkin, James L.; Burdin, A.M.; Ryazanov, D.A.
2000-01-01
We used 742 beach-cast carcasses to characterize age- and sex-specific sea otter mortality during the winter of 1990-1991 at Bering Island, Russia. We also examined 363 carcasses recovered after the 1989 grounding of the T/V Exxon Valdez, to characterize age and sex composition in the living western Prince William Sound (WPWS) sea otter population. At Bering Island, mortality was male-biased (81%), and 75% were adults. The WPWS population was female-biased (59%) and most animals were subadult (79% of the males and 45% of the females). In the decade prior to 1990-1991 we found increasing sea otter densities (particularly among males), declining prey resources, and declining weights in adult male sea otters at Bering Island. Our findings suggest the increased mortality at Bering Island in 1990-1991 was a density-dependent population response. We propose male-maintained breeding territories and exclusion of juvenile females by adult females, providing a mechanism for maintaining densities in female areas below densities in male areas and for potentially moderating the effects of prey reductions on the female population. Increased adult male mortality at Bering Island in 1990-1991 likely modified the sex and age class structure there toward that observed in Prince William Sound.
Agency Amidst Formidable Structures: How Girls Perform Gender in Science Class
ERIC Educational Resources Information Center
Carlone, Heidi B.; Johnson, Angela; Scott, Catherine M.
2015-01-01
Larger social structures such as race, class, gender, and sexuality and classroom structures like narrowly defined participation practices constrain individuals' agency to engage in untroubled and sustained science identity work. This article explores the central dilemma of attending to structure and agency in settings where inequities are…
ERIC Educational Resources Information Center
Mouratidis, Athanasios A.; Vansteenkiste, Maarten; Sideridis, Georgios; Lens, Willy
2011-01-01
In 2 quasi-experimental field studies in a real-life physical education (PE) setting, the authors investigated whether the interest-enjoyment and vitality of Greek pupils (age range, 10-12 years) varied from class to class as a function of the class-to-class variation in the manipulated motivational environment (Studies 1 and 2) and pupils'…
Age, Gender and Social Class in ELT Coursebooks: A Critical Study
ERIC Educational Resources Information Center
Arikan, Arda
2004-01-01
Recent trends in English Language Teaching (ELT) research necessitates the study of course books and instructional materials from various perspectives including but not limited to their cultural, social, and psychological qualities and effects (Kramsch 2000). Age, social class, and gender, as represented in course books are studied because…
Plethodontid salamander response to Silvilcultural Practices in Missouri Ozark forests
Laura A. Herbeck; David R. Larsen
1999-01-01
There is little information on the effects of tree harvest on salamander populations in the midwestern United States. We present data on plethodontid salamander densities in replicated stands of three forest age classes in the southeastern Ozarks of Missouri. Forest age classes consisted of regeneration-cut sites
7 CFR 457.107 - Florida citrus fruit crop insurance provisions.
Code of Federal Regulations, 2014 CFR
2014-01-01
...; (2) Remained on the tree after damage occurred; (3) Except as provided in (b), was missing, damaged... policies: Florida Citrus Fruit Crop Insurance Provisions 1. Definitions Age class. Trees in the unit are... applicable combination of commodity type, intended use, and age class of trees, within a citrus fruit...
Age, Gender and Social Class in ELT Coursebooks: A Critical Study
ERIC Educational Resources Information Center
Arikan, Arda
2005-01-01
Recent trends in English Language Teaching (ELT) research necessitates the study of coursebooks and instructional materials from various perspectives including but not limited to their cultural, social, and psychological qualities and effects (Kramsch 2000). Age, social class, and gender, as represented in coursebooks are studied because teachers…
Prevalence of depressive disorders in Rasht, Iran: A community based study
2008-01-01
Introduction Depression is a well known health problem worldwide. Prevalence of depressive disorders varies in different societies. Aim to determine the prevalence of depressive disorders and some associated factors in Rasht City (Northern part of Iran). Materials and methods 4020 subjects were selected among 394925 residents of Rasht aged between 18–70 during 2003 – 2004. In the first phase, subjects were screened by Beck's Depression Inventory. In the second phase, those who scored more than 15 were assessed through semi-structured psychiatric interview (DSMIV-TR). Socio-demographic characteristics including age, gender, marital status, educational level, and socio-economic class were recorded as well. Results 9.5% of samples (63% female and 37% male) were diagnosed by depressive disorders. The prevalence of minor depressive disorder, dysthymia and major depressive disorder was 5%, 2/5%, and 1% respectively. Socio-economic class was significantly associated with both depressive symptoms based on BDI score (p < 0.001) and depressive disorders based on clinical interview (p < 0.001). Conclusion Comparing to other studies, this study revealed that prevalence of dysthymic and minor depressive disorder were more than major depressive disorder, and low socio-economic class was the most significant risk factor associated with depression. Regarding our study limitations, researchers and policy makers should not consider our findings as conclusive results. Findings of this study could be applied by researchers using analytical methodology to assess relationship between depressive disorders and associated factors. PMID:18601715
Pilot study on infant swimming classes and early motor development.
Dias, Jorge A B de S; Manoel, Edison de J; Dias, Roberta B de M; Okazaki, Victor H A
2013-12-01
Alberta Infant Motor Scale (AIMS) scores were examined before and after four months of swimming classes in 12 babies (ages 7 to 9 mo.) assigned to Experimental (n = 6) and Control (n = 6) groups matched on age and developmental status. Infants from both groups improved their developmental status from pre- to post-test; the Experimental group improved on mean percentile rank. The sample size and the discriminative power of the AIMS do not allow conclusive judgments on these group differences, hence on the effect of infant swimming classes. Nevertheless, a number of recommendations are made for future studies on the effect of swimming classes on infant motor development.
Tully, Lucy A; Moffitt, Terrie E; Caspi, Avshalom; Taylor, Alan; Kiernan, Helena; Andreou, Penny
2004-04-01
We investigated the effects of classroom separation on twins' behavior, progress at school, and reading abilities. This investigation was part of a longitudinal study of a nationally-representative sample of twins (the E-risk Study) who were assessed at the start of school (age 5) and followed up (age 7). We examined three groups of twins: pairs who were in the same class at both ages; pairs who were in separate classes at both ages; and pairs who were in the same class at age 5, but separated by age 7. When compared to those not separated, those separated early had significantly more teacher-rated internalizing problems and those separated later showed more internalizing problems and lower reading scores. Monozygotic (MZ) twins showed more problems as a result of separation than dizygotic (DZ) twins. No group differences emerged for externalizing problems, ADHD or prosocial behaviors. The implications of the findings for parents and teachers of twins, and for school practices about separating twins, are discussed.
Ekeus, Cecilia; Christensson, Kyllike
2003-06-01
to describe and compare sexual and reproductive history as well as reactions to the pregnancy and attendance in antenatal care, family classes and childbirth of fathers of babies born to teenage mothers and fathers of babies born to average aged mothers. a descriptive comparative study using a structured questionnaire for data collection. eleven postnatal wards at the five obstetric and gynaecological departments in the Stockholm area. 132 fathers of babies born to primiparous teenage mothers (Group A) and the same number of fathers of babies born to primiparous women aged between 25-29 years (Group B) who were present in the postnatal wards. 43 of Group A compared to 17% of the Group B fathers had their first intercourse before 15 years of age. This early sexual debut was related to other health hazard, such as use of illicit drugs and cigarette smoking. The majority of the pregnancies in Group A were unplanned but most fathers reacted positively to the pregnancy and participated in the antenatal care. In contrast, only half of these fathers attended family classes. fathers of babies born to teenage mothers differed from fathers of babies to older mothers regarding reproductive background as well as involvement during pregnancy. The findings of this study challenge midwives to organise clinical practice in order to meet the specific needs of this group.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Williams, Greg D.; Evans, Nathan R.; Pearson, Walter H.
2001-10-30
The primary goal of our research this spring/ summer was to refine techniques and examine scenarios under which a standardized protocol could be applied to assess juvenile coho salmon (O. kisutch) passage through road culverts. Field evaluations focused on capture-mark- recapture methods that allowed analysis of fish movement patterns, estimates of culvert passability, and potential identification of cues inducing these movements. At this stage, 0+ age coho salmon fry 30 mm to 65 mm long (fork length) were the species and age class of interest. Ultimately, the protocol will provide rapid, statistically rigorous methods for trained personnel to perform standardizedmore » biological assessments of culvert passability to a number of juvenile salmon species. Questions to be addressed by the research include the following: ? Do hydraulic structures such as culverts restrict habitat for juvenile salmonids? ? How do existing culverts and retrofits perform relative to juvenile salmonid passage? ? Do some culvert characteristics and hydraulic conditions provide better passage than others? ? Does the culvert represent a barrier to certain size classes of fish? Recommendations addressed issues of study site selection, initial capture, marking, recapture/observations, and estimating movement.« less
New perspectives on the Popigai impact structure
NASA Technical Reports Server (NTRS)
Garvin, J. B.; Deino, A. L.
1992-01-01
The record of large-scale cratering on Earth is scant, and the only currently 'proven' 100-km-class impact structure known to have formed within the Cenozoic is Popigai, located in the Siberian Arctic at 71.5 deg N, 111 deg E. Popigai is clearly a multiringed impact basin formed within the crystalline shield rocks (Anabar) and platform sediments of the Siberian taiga, and estimates of the volume of preserved impact melt typically exceed 1700 cu km, which is within a factor of 2-3 of what would be predicted using scaling relationships. We present the preliminary results of an analysis of the present-day topography of the Popigai structure, together with refined absolute age estimates, in order to reconstruct the pre-erosional morphology of the basin, as well as to quantify the erosion or sediment infill rates in the Popigai region.
Crucial HSP70 co–chaperone complex unlocks metazoan protein disaggregation
Nillegoda, Nadinath B.; Kirstein, Janine; Szlachcic, Anna; Berynskyy, Mykhaylo; Stank, Antonia; Stengel, Florian; Arnsburg, Kristin; Gao, Xuechao; Scior, Annika; Aebersold, Ruedi; Guilbride, D. Lys; Wade, Rebecca C.; Morimoto, Richard I.; Mayer, Matthias P.; Bukau, Bernd
2016-01-01
Protein aggregates are the hallmark of stressed and ageing cells, and characterize several pathophysiological states1,2. Healthy metazoan cells effectively eliminate intracellular protein aggregates3,4, indicating that efficient disaggregation and/or degradation mechanisms exist. However, metazoans lack the key heat-shock protein disaggregase HSP100 of non-metazoan HSP70-dependent protein disaggregation systems5,6, and the human HSP70 system alone, even with the crucial HSP110 nucleotide exchange factor, has poor disaggregation activity in vitro4,7. This unresolved conundrum is central to protein quality control biology. Here we show that synergic cooperation between complexed J-protein co-chaperones of classes A and B unleashes highly efficient protein disaggregation activity in human and nematode HSP70 systems. Metazoan mixed-class J-protein complexes are transient, involve complementary charged regions conserved in the J-domains and carboxy-terminal domains of each J-protein class, and are flexible with respect to subunit composition. Complex formation allows J-proteins to initiate transient higher order chaperone structures involving HSP70 and interacting nucleotide exchange factors. A network of cooperative class A and B J-protein interactions therefore provides the metazoan HSP70 machinery with powerful, flexible, and finely regulatable disaggregase activity and a further level of regulation crucial for cellular protein quality control. PMID:26245380
Skeletal pattern in subjects with temporomandibular joint disorders
Almăşan, Oana Cristina; Almăşan, Horea Artimoniu; Bran, Simion; Lascu, Liana; Iancu, Mihaela; Băciuţ, Grigore
2013-01-01
Introduction To establish the skeletal pattern in subjects with malocclusions and temporomandibular disorders (TMD); to assess the relationship between craniofacial skeletal structures and TMD in subjects with malocclusions. Material and methods Sixty-four subjects with malocclusions, over 18 years of age, were included in the study. Temporomandibular disorders were clinically assessed according to the Helkimo Anamnestic Index. Subjects underwent a lateral cephalogram. Subjects were grouped according to the sagittal skeletal pattern (ANB angle) into class I, II and III. Parametric Student tests with equal or unequal variations were used (variations were previously tested with Levene test). Results Twenty-four patients with TMD (experimental sample); 40 patients without TMD (control group); interincisal angle was higher in class I and II (p < 0.05) experimental subjects; overjet was larger in experimental subjects; midline shift and Wits appraisal were broader in the experimental group in all three classes. In class III subjects, the SNB angle was higher in the experimental group (p = 0.01). Joint noises followed by reduced mandible mobility, muscular pain and temporomandibular joint (TMJ) pain were the most frequent symptoms in subjects with TMD and malocclusions. Conclusions Temporomandibular joint status is an important factor to consider when planning orthodontic treatment in patients with severe malocclusions; midline shift, large overjet and deep overbite have been associated with signs and symptoms of TMD. PMID:23515361
Code of Federal Regulations, 2011 CFR
2011-10-01
... serviceability of freight containers and vehicles carrying Class 1 (explosive) materials on ships. (a) Except for... 49 Transportation 2 2011-10-01 2011-10-01 false Structural serviceability of freight containers and vehicles carrying Class 1 (explosive) materials on ships. 176.172 Section 176.172 Transportation...
Code of Federal Regulations, 2013 CFR
2013-10-01
... serviceability of freight containers and vehicles carrying Class 1 (explosive) materials on ships. (a) Except for... 49 Transportation 2 2013-10-01 2013-10-01 false Structural serviceability of freight containers and vehicles carrying Class 1 (explosive) materials on ships. 176.172 Section 176.172 Transportation...
Code of Federal Regulations, 2014 CFR
2014-10-01
... serviceability of freight containers and vehicles carrying Class 1 (explosive) materials on ships. (a) Except for... 49 Transportation 2 2014-10-01 2014-10-01 false Structural serviceability of freight containers and vehicles carrying Class 1 (explosive) materials on ships. 176.172 Section 176.172 Transportation...
ERIC Educational Resources Information Center
Jackson, Charles C.
2006-01-01
A multicultural curriculum is one that includes all cultures that make up the United States, and social class is one factor to address when considering such a curriculum. Social class is often misperceived as the middle class social strata, because it is the core structure within the United States. Culture is a social personality structure, and it…
The year-class phenomenon and the storage effect in marine fishes
NASA Astrophysics Data System (ADS)
Secor, David H.
2007-02-01
Factors contributing to population growth through strong year-class formation have driven a century of directed research in fisheries science. A central discovery of Hjort's paradigm was that multiple generations overlap and longevity is matched with frequency of strong recruitments. Here, I elaborate on this tenet by examining how intra-population modalities in spawning and early habitat use favour population resiliency. A modern theory that has application is the storage effect [Warner, R.R., Chesson, P.L., 1985. Coexistence mediated by recruitment fluctuations - a field guide to the storage effect. Am. Nat. 125, 769-787], whereby spawning stock biomass accumulates each year so that when early survival conditions are favourable, stored egg production can result in explosive population growth. I review two early life history behaviours that contribute to the storage effect: split cohorts (i.e., seasonal pulses of eggs and larvae) and contingent behaviour (i.e., dispersive and retentive patterns in early dispersal). Episodic and pulsed production of larvae is a common feature for marine fishes, well documented through otolith microstructure and hatch-date analyses. In temperate and boreal fishes, early and late spawned cohorts of larvae and juveniles may have differing fates dependent upon seasonal and inter-annual fluctuations in weather and climate. Often, a coastal fish may spawn for a protracted period, yet only a few days' egg production will result in successful recruitment. In these and other instances, it is clear that diversity in spawning behaviour can confer resilience against temporal variations in early survival conditions. Although many factors contribute to intra-population spawning modalities, size and age structure of adults play an important role. Contingent structure, an idea dating to Hjort (herring contingents) and Gilbert (salmon contingents), has been resurrected to describe the diversity of intra-population modalities observed through otolith microchemical and electronic tagging approaches. Retentive and dispersive behaviours confer resiliency against early survival conditions that vary spatially. Examples of contingent structure are increasingly numerous for diadromous fishes. Here, a nursery habitat associated with a contingent behaviour may make a small contribution in a given year, but over a decade contribute significantly to spawning stock biomass. For flatfish and other marine fishes, contingent structure is probable but not well documented. Proximate factors leading to contingent structure are poorly known, but for diadromous fishes, time of spawning and early life history energetic thresholds is hypothesized to lead to alternative life cycles. Here again time of spawning may lead to the storage effect by hedging against spatial variance in early vital rates. Managing for the storage effect will be promoted by conservation of adult age structure and early habitats upon which both strong and weak year-classes rely.
Using Latent Class Analysis to Model Temperament Types.
Loken, Eric
2004-10-01
Mixture models are appropriate for data that arise from a set of qualitatively different subpopulations. In this study, latent class analysis was applied to observational data from a laboratory assessment of infant temperament at four months of age. The EM algorithm was used to fit the models, and the Bayesian method of posterior predictive checks was used for model selection. Results show at least three types of infant temperament, with patterns consistent with those identified by previous researchers who classified the infants using a theoretically based system. Multiple imputation of group memberships is proposed as an alternative to assigning subjects to the latent class with maximum posterior probability in order to reflect variance due to uncertainty in the parameter estimation. Latent class membership at four months of age predicted longitudinal outcomes at four years of age. The example illustrates issues relevant to all mixture models, including estimation, multi-modality, model selection, and comparisons based on the latent group indicators.
Cohen, Bradley S.; Miller, Karl V.
2017-01-01
Prey species must balance predator avoidance behavior with other essential activities including foraging, breeding, and social interactions. Anti-predator behaviors such as vigilance can impede resource acquisition rates by altering foraging behavior. However, in addition to predation risk, foraging behavior may also be affected by socio-sexual factors including breeding chronology and social interactions. Therefore, we investigated how time-of-day, distance-to-forest, group size, social interactions (presence of different sex-age class), and breeding chronology (pre-breeding, breeding, post-breeding seasons) affected probability of feeding (hereafter: feeding) for different sex and age-classes (mature males, immature males, adult females, and juveniles) of white-tailed deer at feed sites. We developed a set of candidate models consisting of social, habitat, reproductive, and abiotic factors and combinations of these factors. We then used generalized linear mixed models (GLMMs) to estimate the probability of feeding and used model averaging of competing models for multimodel inference. Each adult sex-age class’ feeding was influenced by breeding chronology. Juveniles were more likely to be feeding than adults in all seasons. Feeding increased with group size for all sex-age classes. The presence of a mature male negatively influenced the feeding of immature males and juveniles were more likely to be feeding when an adult female was present. Feeding decreased with increasing distance-to-forest for mature males but not for other sex-age classes. Our results indicate that each sex-age class modulates vigilance levels in response to socio-sexual factors according to the unique pressures placed upon them by their reproductive status and social rank. PMID:28591136
Jester, Jennifer M; Buu, Anne; Zucker, Robert A
2016-11-01
Alcoholism is a heterogeneous disorder; however, characterization of life-course variations in symptomatology is almost nonexistent, and developmentally early predictors of variations are very poorly characterized. In this study, the course of alcoholic symptomatology over 32 years is differentiated, and predictors and covariates of trajectory class membership are identified. A community sample of alcoholic and neighborhood matched control families, 332 men and 336 women, was recruited based on alcoholism in the men. Symptoms were assessed retrospectively at baseline (mean age = 32) back to age 15 and prospectively from baseline every 3 years for 15 years. Trajectory classes were established using growth mixture modeling. Men and women had very similarly shaped trajectory classes: developmentally limited (men: 29%, women: 42%), developmentally cumulative (men: 26%, women: 38%), young adult onset (men: 31%, women: 21%), and early onset severe (men: 13%). Three factors at age 15 predicted class membership: family history of alcoholism, age 15 symptoms, and level of childhood antisocial behavior. Numerous measures of drinking and other psychopathology were also associated with class membership. The findings suggest that clinical assessments can be crafted where the profile of current and historical information can predict not only severity of prognosis but also future moderation of symptoms and/or remission over intervals as long as decades.
Zhao, Yingming; Kocovsky, Patrick M.; Madenjian, Charles P.
2013-01-01
We developed an updated stock–recruitment relationship for Lake Erie Walleye Sander vitreus using the Akaike information criterion model selection approach. Our best stock–recruitment relationship was a Ricker spawner–recruit function to which spring warming rate was added as an environmental variable, and this regression model explained 39% of the variability in Walleye recruitment over the 1978 through 2006 year-classes. Thus, most of the variability in Lake Erie Walleye recruitment appeared to be attributable to factors other than spawning stock size and spring warming rate. The abundance of age-0 Gizzard Shad Dorosoma cepedianum, which was an important term in previous models, may still be an important factor for Walleye recruitment, but poorer ability to monitor Gizzard Shad since the late 1990s could have led to that term failing to appear in our best model. Secondly, we used numerical simulation to demonstrate how to use the stock recruitment relationship to characterize the population dynamics (such as stable age structure, carrying capacity, and maximum sustainable yield) and some biological reference points (such as fishing rates at different important biomass or harvest levels) for an age-structured population in a deterministic way.
Royle, J. Andrew; Sutherland, Christopher S.; Fuller, Angela K.; Sun, Catherine C.
2015-01-01
We develop a likelihood analysis framework for fitting spatial capture-recapture (SCR) models to data collected on class structured or stratified populations. Our interest is motivated by the necessity of accommodating the problem of missing observations of individual class membership. This is particularly problematic in SCR data arising from DNA analysis of scat, hair or other material, which frequently yields individual identity but fails to identify the sex. Moreover, this can represent a large fraction of the data and, given the typically small sample sizes of many capture-recapture studies based on DNA information, utilization of the data with missing sex information is necessary. We develop the class structured likelihood for the case of missing covariate values, and then we address the scaling of the likelihood so that models with and without class structured parameters can be formally compared regardless of missing values. We apply our class structured model to black bear data collected in New York in which sex could be determined for only 62 of 169 uniquely identified individuals. The models containing sex-specificity of both the intercept of the SCR encounter probability model and the distance coefficient, and including a behavioral response are strongly favored by log-likelihood. Estimated population sex ratio is strongly influenced by sex structure in model parameters illustrating the importance of rigorous modeling of sex differences in capture-recapture models.
SVM-Fold: a tool for discriminative multi-class protein fold and superfamily recognition
Melvin, Iain; Ie, Eugene; Kuang, Rui; Weston, Jason; Stafford, William Noble; Leslie, Christina
2007-01-01
Background Predicting a protein's structural class from its amino acid sequence is a fundamental problem in computational biology. Much recent work has focused on developing new representations for protein sequences, called string kernels, for use with support vector machine (SVM) classifiers. However, while some of these approaches exhibit state-of-the-art performance at the binary protein classification problem, i.e. discriminating between a particular protein class and all other classes, few of these studies have addressed the real problem of multi-class superfamily or fold recognition. Moreover, there are only limited software tools and systems for SVM-based protein classification available to the bioinformatics community. Results We present a new multi-class SVM-based protein fold and superfamily recognition system and web server called SVM-Fold, which can be found at . Our system uses an efficient implementation of a state-of-the-art string kernel for sequence profiles, called the profile kernel, where the underlying feature representation is a histogram of inexact matching k-mer frequencies. We also employ a novel machine learning approach to solve the difficult multi-class problem of classifying a sequence of amino acids into one of many known protein structural classes. Binary one-vs-the-rest SVM classifiers that are trained to recognize individual structural classes yield prediction scores that are not comparable, so that standard "one-vs-all" classification fails to perform well. Moreover, SVMs for classes at different levels of the protein structural hierarchy may make useful predictions, but one-vs-all does not try to combine these multiple predictions. To deal with these problems, our method learns relative weights between one-vs-the-rest classifiers and encodes information about the protein structural hierarchy for multi-class prediction. In large-scale benchmark results based on the SCOP database, our code weighting approach significantly improves on the standard one-vs-all method for both the superfamily and fold prediction in the remote homology setting and on the fold recognition problem. Moreover, our code weight learning algorithm strongly outperforms nearest-neighbor methods based on PSI-BLAST in terms of prediction accuracy on every structure classification problem we consider. Conclusion By combining state-of-the-art SVM kernel methods with a novel multi-class algorithm, the SVM-Fold system delivers efficient and accurate protein fold and superfamily recognition. PMID:17570145
A Survey of Musculoskeletal Injuries Associated with Zumba
Nichols, Andrew; Maskarinec, Gregory; Tseng, Chien-Wen
2013-01-01
Zumba is a highly popular Latin-inspired dance fitness program with ∼14 million participants in 150 countries. However, there is little published data on the rates or types of injuries among participants. We surveyed a convenience sample of 49 adults (100% participation) in 5 Zumba classes in Hawai‘i. Participants described any prior Zumba-related injuries. We used t-tests and logistic regression to determine if participant demographics or intensity of Zumba classes were associated with injuries. Participants were mostly female (82%), averaged 43.9 years of age (range 19 to 69 years), and took an average of 3 classes/week (1–2 hours/class) for an average of 11 months. Fourteen participants (29%) reported 21 prior Zumba-related injuries. Half of the 14 injured sought care from medical providers for their injuries. Of the 21 injuries, the most frequently injured sites were knees (42%), ankles (14%), and shoulders (14%). Participants with Zumba-related injuries did not differ significantly in age, months of Zumba, or hours/class compared to those who did not experience injuries. However, participants who reported injuries took significantly more classes/week (3.8 versus 2.7 classes, P = .006) than non-injured participants. In logistic regression, taking more classes/week remained significantly associated with injuries (odds ratio 3.6 [95% confidence interval 1.5 – 8.9, P = .006]) after controlling for age, gender, months of Zumba, and hours/class. Given Zumba's health benefits, our finding that 1 in 4 Zumba participants have experienced injuries indicates the need to improve Zumba routines, instructor training, and health provider counseling to reduce injury risk. PMID:24377078
ERIC Educational Resources Information Center
Fanti, Kostas A.; Henrich, Christopher C.
2010-01-01
How and why do internalizing and externalizing problems, psychopathological problems from different diagnostic classes representing separate forms of psychopathology, co-occur in children? We investigated the development of pure and co-occurring internalizing and externalizing problems from ages 2 to 12 with the use of latent class growth…
Kitaoku, Yoshihito; Umemoto, Naoyuki; Ohnuma, Takayuki; Numata, Tomoyuki; Taira, Toki; Sakuda, Shohei; Fukamizo, Tamo
2015-10-01
We first solved the crystal structure of class III catalytic domain of a chitinase from fern (PrChiA-cat), and found a structural difference between PrChiA-cat and hevamine. PrChiA-cat was found to have reduced affinities to chitin oligosaccharides and allosamidin. Plant class III chitinases are subdivided into enzymes with three disulfide bonds and those without disulfide bonds. We here referred to the former enzymes as class IIIa chitinases and the latter as class IIIb chitinases. In this study, we solved the crystal structure of the class IIIb catalytic domain of a chitinase from the fern Pteris ryukyuensis (PrChiA-cat), and compared it with that of hevamine, a class IIIa chitinase from Hevea brasiliensis. PrChiA-cat was found to adopt an (α/β)8 fold typical of GH18 chitinases in a similar manner to that of hevamine. However, PrChiA-cat also had two large loops that extruded from the catalytic site, and the corresponding loops in hevamine were markedly smaller than those of PrChiA-cat. An HPLC analysis of the enzymatic products revealed that the mode of action of PrChiA-cat toward chitin oligosaccharides, (GlcNAc) n (n = 4-6), differed from those of hevamine and the other class IIIa chitinases. The binding affinities of (GlcNAc)3 and (GlcNAc)4 toward the inactive mutant of PrChiA-cat were determined by isothermal titration calorimetry, and were markedly lower than those toward other members of the GH18 family. The affinity and the inhibitory activity of allosamidin toward PrChiA-cat were also lower than those toward the GH18 chitinases investigated to date. Several hydrogen bonds found in the crystal structure of hevamine-allosamidin complex were missing in the modeled structure of PrChiA-cat-allosamidin complex. The structural findings for PrChiA-cat successfully interpreted the functional data presented.
Micali, Nadia; Horton, N J; Crosby, R D; Swanson, S A; Sonneville, K R; Solmi, F; Calzo, J P; Eddy, K T; Field, A E
2017-02-01
Diagnostic criteria for eating disorders (ED) remain largely based on clinical presentations, but do not capture the full range of behaviours in the population. We aimed to derive an empirically based ED behaviour classification using behavioural and body mass index (BMI) indicators at three time-points in adolescence, and to validate classes investigating prospective associations with adverse outcomes. Adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC) provided data on ED at age 14 (n = 6615), 16 (n = 5888), and 18 years (n = 5100), and had weight and height measured. Psychological and behavioural outcomes were assessed at 15.5/16 and 17.5/18 years. We fit gender- and age-stratified latent class models, and employed logistic regression to investigate associations between classes and later outcomes. One asymptomatic and two symptomatic (largely representing higher and lower frequency ED behaviours) classes were observed at each time-point, although their relative prevalence varied by age and gender. The majority of girls in symptomatic classes remained symptomatic at subsequent assessments. Girls in symptomatic classes had higher odds of subsequent anxiety and depressive disorders, binge drinking, drug use, and deliberate self-harm. Data analyses were underpowered amongst boys. The presence of two symptomatic classes (characterised by different ED behaviour frequency) and their prospective association with adverse outcomes suggest a need to refine diagnostic thresholds based on empirical data. Despite some instability of classes, particularly in mid-adolescence, evidence that half of girls in symptomatic classes remained symptomatic suggests persistence of ED behaviours in adolescence, and highlights a need for early identification to reduce chronicity.
45 CFR 1306.32 - Center-based program option.
Code of Federal Regulations, 2011 CFR
2011-10-01
... Center-based program option. (a) Class size. (1) Head Start classes must be staffed by a teacher and an aide or two teachers and, whenever possible, a volunteer. (2) Grantees must determine their class size based on the predominant age of the children who will participate in the class and whether or not a...
The Quality and Effectiveness of Confirmation Classes in Finland
ERIC Educational Resources Information Center
Niemela, Kati
2006-01-01
Every year some 90% of 15-year-olds in Finland attend confirmation classes in the Evangelical Lutheran Church of Finland, which is greater than the percentage of that age group belonging to the Church. What is behind the popularity of Finnish confirmation classes? This article scrutinizes the quality and effectiveness of confirmation classes.…
Code of Federal Regulations, 2010 CFR
2010-04-01
... Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950... class or classes of employees to whose wages this method of computing contributions applies. For example... any class or classes of employees identified in an agreement or modification. In its notification, the...
Estimating age ratios and size of pacific walrus herds on coastal haulouts using video imaging.
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
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
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
Chemical Space Mapping and Structure-Activity Analysis of the ChEMBL Antiviral Compound Set.
Klimenko, Kyrylo; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre
2016-08-22
Curation, standardization and data fusion of the antiviral information present in the ChEMBL public database led to the definition of a robust data set, providing an association of antiviral compounds to seven broadly defined antiviral activity classes. Generative topographic mapping (GTM) subjected to evolutionary tuning was then used to produce maps of the antiviral chemical space, providing an optimal separation of compound families associated with the different antiviral classes. The ability to pinpoint the specific spots occupied (responsibility patterns) on a map by various classes of antiviral compounds opened the way for a GTM-supported search for privileged structural motifs, typical for each antiviral class. The privileged locations of antiviral classes were analyzed in order to highlight underlying privileged common structural motifs. Unlike in classical medicinal chemistry, where privileged structures are, almost always, predefined scaffolds, privileged structural motif detection based on GTM responsibility patterns has the decisive advantage of being able to automatically capture the nature ("resolution detail"-scaffold, detailed substructure, pharmacophore pattern, etc.) of the relevant structural motifs. Responsibility patterns were found to represent underlying structural motifs of various natures-from very fuzzy (groups of various "interchangeable" similar scaffolds), to the classical scenario in medicinal chemistry (underlying motif actually being the scaffold), to very precisely defined motifs (specifically substituted scaffolds).
Ontogenetic shifts in habitat use by the endangered Roanoke logperch (Percina rex)
Amanda Rosenberger; Paul L. Angermeier
2003-01-01
1. Conservation of the federally endangered Roanoke logperch (Percina rex, Jordan and Evermann) necessitates protection of habitat that is critical for all age classes. We examined habitat use patterns of individual logperch to determine: (1) if age classes of logperch in the Nottoway and Roanoke Rivers exhibit habitat selectivity, (2) if...
Decision Processes Among the Elderly: Do They Differ?
ERIC Educational Resources Information Center
Goodchilds, Jacqueline D.; Bikson, Tora K.
Decision making processes among older adults were investigated within the context of grocery selection, using a stimulus array involving two product classes (bread and cheese) with 10 items per class. The sample (N=580) was stratified by sex, household status (living alone or with spouse), and age, employing three age groupings: 25-34 (young),…
Clarke, Philippa J; O'Malley, Patrick M; Schulenberg, John E; Johnston, Lloyd D
2010-09-01
The health consequences of obesity and overweight have been well documented, but less research has examined their social and economic consequences. This paper examines the long-term consequences of early adult overweight for midlife health and socioeconomic attainment using prospective nationally representative panel data from American adults in the Monitoring the Future Study (1986-2008). Growth mixture models identified 2 distinct latent classes of trajectories of body mass index (BMI) from age 19 to 35 years: a persistently overweight class (BMI >25 kg/m(2)) and a second class exhibiting more moderate growth in BMI to age 35 years. Women (odds ratio (OR) = 2.16, 95% confidence interval (CI): 1.39, 3.36) and those from a lower childhood socioeconomic position (OR = 1.71, 95% CI: 1.30, 2.24) were more likely to be in the persistently overweight class. Compared with those in the moderately increasing BMI class, those in the persistently overweight class were more likely to have a chronic health problem at age 40 years (OR = 2.74, 95% CI: 2.20, 3.43), to have no further education beyond high school (OR = 1.33, 95% CI: 1.04, 1.69), and to have a higher odds of receiving welfare or unemployment compensation at age 40 years (OR = 1.76, 95% CI: 1.49, 2.04). These findings highlight the importance of addressing persistent obesity and overweight early in the life course.
[Self-concept of school-age children: the norm in Kaohsiung].
Chin, C C; Liu, Y Y; Ka, J K
1989-05-01
This study has two objectives: (1) to establish the norm of three graphical projective tests (Children's Social-Self Test, Children's Attitude Inventory and Children's Self-Concept Inventory), and (2) to explore the influence of sex, order of birth, social economic status of family, and leadership of class that effect self-concept of the school-age children. These subjects are selected from elementary schools in Kaohsiung, twenty-two classes are drawn out from each grade by systemic-random sampling. Then two classes are drawn out from 22 classes at random to arrange retest for reliability. The total subjects are 6207 students. From October 1987 to June 1988, six researchers are divided into three group to conduct the test. Besides establishing the norm, we find results from analysis of data as follow: 1. The reliability and validity of three graphical projective tests are good, they can be used for assessing the self-concept of school-age children. 2. The grade, sex, order of birth, social economic status of family, leadership of class all influence the self-concept of school-age children. 3. The self-concept and the grade has negative correlation. 4. The self-concept and the social economic status of family has positive correlation. 5. The girls have higher self-concept than the boys. 6. The order of first-born or second-born has higher self-concept than the others. 7. The ones who are leaders of class have higher self-concept than the others.
ERIC Educational Resources Information Center
Lins-Dyer, Maria Tereza; Nucci, Larry
2007-01-01
The impact of social class was explored on Brazilian mothers' and daughters' conceptions of who should, and who actually would control decisions regarding the daughters' actions. Participants were 126 middle class and 126 lower class girls aged 11-16 years, and their mothers. No social class differences were found in daughters' judgments about who…
The social class gradient in health in Spain and the health status of the Spanish Roma.
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.
Bennett, Pamela R; Lutz, Amy; Jayaram, Lakshmi
2012-01-01
We investigate cultural and structural sources of class differences in youth activity participation with interview, survey, and archival data. We find working- and middle-class parents overlap in parenting logics about participation, though differ in one respect: middle-class parents are concerned with customizing children's involvement in activities, while working-class parents are concerned with achieving safety and social mobility for children through participation. Second, because of financial constraints, working-class families rely on social institutions for participation opportunities, but few are available. Schools act as an equalizing institution by offering low-cost activities, allowing working-class children to resemble middle-class youth in school activities, but they remain disadvantaged in out-of-school activities. School influences are complex, however, as they also contribute to class differences by offering different activities to working- and middle-class youth. Findings raise questions about the extent to which differences in participation reflect class culture rather than the objective realities parents face.
Bennett, Pamela R.; Lutz, Amy; Jayaram, Lakshmi
2014-01-01
We investigate cultural and structural sources of class differences in youth activity participation with interview, survey, and archival data. We find working- and middle-class parents overlap in parenting logics about participation, though differ in one respect: middle-class parents are concerned with customizing children’s involvement in activities, while working-class parents are concerned with achieving safety and social mobility for children through participation. Second, because of financial constraints, working-class families rely on social institutions for participation opportunities, but few are available. Schools act as an equalizing institution by offering low-cost activities, allowing working-class children to resemble middle-class youth in school activities, but they remain disadvantaged in out-of-school activities. School influences are complex, however, as they also contribute to class differences by offering different activities to working- and middle-class youth. Findings raise questions about the extent to which differences in participation reflect class culture rather than the objective realities parents face. PMID:25328250
Sport, how people choose it: A network analysis approach.
Ferreri, Luca; Ivaldi, Marco; Daolio, Fabio; Giacobini, Mario; Rainoldi, Alberto; Tomassini, Marco
2015-01-01
In order to investigate the behaviour of athletes in choosing sports, we analyse data from part of the We-Sport database, a vertical social network that links athletes through sports. In particular, we explore connections between people sharing common sports and the role of age and gender by applying "network science" approaches and methods. The results show a disassortative tendency of athletes in choosing sports, a negative correlation between age and number of chosen sports and a positive correlation between age of connected athletes. Some interesting patterns of connection between age classes are depicted. In addition, we propose a method to classify sports, based on the analyses of the behaviour of people practising them. Thanks to this brand new classifications, we highlight the links of class of sports and their unexpected features. We emphasise some gender dependency affinity in choosing sport classes.
Variation in body mass of wild canvasback and redhead ducklings
Austin, Jane E.; Serie, Jerome R.
1994-01-01
We assessed variation in body mass of ducklings in single- and mixed-species broods of wild Canvasbacks (Aythya valisineria) and Redheads (Aythya americana) 20-50 days old. Body mass of canvasback ducklings was not affected by year and season (early vs. late hatch date) despite changes in water conditions. Mean body mass of male and female Canvasbacks did not differ in Class IIA but did differ in older age classes. Within-brood differences in body mass tended to be higher in Class IIA ducklings (6-7% of mean body mass for Canvasbacks, 9-11% in Redheads) and generally declined to 4-6% in Class IIC and older ducklings. Some within-brood differences were as high as 20-30% of mean body mass. Tests to assess sources of within-brood variation (age, sex, and season) in body mass for Canvasbacks were inconclusive. Variation within broods was generally less than that among broods for both Canvasbacks and Redheads. The lack of differences in duckling body mass between single- and mixed-species broods for any age class, sex, or species suggests that mass was not affected by interspecific brood parasitism.
Galich, L V; Kuroedova, V; Lakhtin, Yu; Galich, L B; Moskalenko, P
2017-03-01
The aim of the work was to study the structure of dentofacial anomalies in children and adolescents in Sumy city and Sumy oblast, to identify dentoalveolar morphological peculiarities of the occlusion in 10-13 years old patients with class ІІ1 anomalies according to Angle's classification with different types of lower jaw bone growth. A retrospective analysis of 2236 outpatient dental cards of urban and rural patients with orthodontic pathology was conducted. Patients were divided into three age groups: 6-9 years old (early mixed occlusion) - 592 children; 10-13 years old (late mixed occlusion) - 1180 children; over 13 years old (permanent occlusion) - 464 persons; besides 76 patients with class ІІ1 anomalies according to Angle's classification aged 10-13 years were examined. To determine the type of lower jaw growth, the children underwent orthopantomographic examination, diagnostic models were made and biometric indicators were calculated to determine the severity of the morphological changes. It was established that anomalies of individual teeth and dental curve dominated in all age groups (71.24%). Among the occlusion anomalies, a large part falls to class ІІ anomalies according to Angle's classification (19.18%). A third of these patients have a neutral type of lower jaw growth (36.84±5.53%), horizontal and vertical types of growth reach 18.42±4.47% and 19.74±4.56%, respectively. The combination of neutral and vertical type of growth of the lower jaw occurs in 1.7 times more than the combination of neutral and horizontal. The most pronounced morphological changes were observed in the group of patients with a horizontal type of lower jaw growth. When planning treatment and prophylactic measures among patients of the orthodontic profile, it is necessary to take into account the peculiarities of both the prevalence of pathology in the region and the morphological changes of different severity in the dental curves of the jaws.
DOCKING OF STRUCTURALLY RELATED DIOLEPOXIDES OF BENZO(GHI)FLUORANTHENE WITH DNA
Docking of structurally-related diolepoxides of benzo{ghi}fluoranthene and benzo{c}phenanthrene with DNA
Polycyclic aromatic hydrocarbons are a class of chemicals found in the environment. Some class members are potent carcinogens while others with similar structures show litt...
Structural Validity of CLASS K-3 in Primary Grades: Testing Alternative Models
ERIC Educational Resources Information Center
Sandilos, Lia E.; Shervey, Sarah Wollersheim; DiPerna, James C.; Lei, Puiwa; Cheng, Weiyi
2017-01-01
This study examined the internal structure of the Classroom Assessment Scoring System (CLASS; K-3 version). The original CLASS K-3 model (Pianta, La Paro, & Hamre, 2008) and 5 alternative models were tested using confirmatory factor analysis with a sample of first- and second-grade classrooms (N = 141). Findings indicated that a slightly…
Masuda, Taro; Zhao, Guanghua; Mikami, Bunzo
2015-01-01
Chitinase hydrolyzes the β-1,4-glycosidic bond in chitin. In higher plants, this enzyme has been regarded as a pathogenesis-related protein. Recently, we identified a class III chitinase, which functions as a calcium storage protein in pomegranate (Punica granatum) seed (PSC, pomegranate seed chitinase). Here, we solved a crystal structure of PSC at 1.6 Å resolution. Although its overall structure, including the structure of catalytic site and non-proline cis-peptides, was closely similar to those of other class III chitinases, PSC had some unique structural characteristics. First, there were some metal-binding sites with coordinated water molecules on the surface of PSC. Second, many unconserved aspartate residues were present in the PSC sequence which rendered the surface of PSC negatively charged. This acidic electrostatic property is in contrast to that of hevamine, well-characterized plant class III chitinase, which has rather a positively charged surface. Thus, the crystal structure provides a clue for metal association property of PSC.
Keeley, Jon E; Zedler, Paul H
2009-01-01
We evaluate the fine-grain age patch model of fire regimes in southern California shrublands. Proponents contend that the historical condition was characterized by frequent small to moderate size, slow-moving smoldering fires, and that this regime has been disrupted by fire suppression activities that have caused unnatural fuel accumulation and anomalously large and catastrophic wildfires. A review of more than 100 19th-century newspaper reports reveals that large, high-intensity wildfires predate modern fire suppression policy, and extensive newspaper coverage plus first-hand accounts support the conclusion that the 1889 Santiago Canyon Fire was the largest fire in California history. Proponents of the fine-grain age patch model contend that even the very earliest 20th-century fires were the result of fire suppression disrupting natural fuel structure. We tested that hypothesis and found that, within the fire perimeters of two of the largest early fire events in 1919 and 1932, prior fire suppression activities were insufficient to have altered the natural fuel structure. Over the last 130 years there has been no significant change in the incidence of large fires greater than 10,000 ha, consistent with the conclusion that fire suppression activities are not the cause of these fire events. Eight megafires (> or = 50,000 ha) are recorded for the region, and half have occurred in the last five years. These burned through a mosaic of age classes, which raises doubts that accumulation of old age classes explains these events. Extreme drought is a plausible explanation for this recent rash of such events, and it is hypothesized that these are due to droughts that led to increased dead fine fuels that promoted the incidence of firebrands and spot fires. A major shortcoming of the fine-grain age patch model is that it requires age-dependent flammability of shrubland fuels, but seral stage chaparral is dominated by short-lived species that create a dense surface layer of fine fuels. Results from the Behave Plus fire model with a custom fuel module for young chaparral shows that there is sufficient dead fuel to spread fire even under relatively little winds. Empirical studies of fuel ages burned in recent fires illustrate that young fuels often comprise a major portion of burned vegetation, and there is no difference between evergreen chaparral and semi-deciduous sage scrub. It has also been argued that the present-day fire size distribution in northern Baja California is a model of the historical patterns that were present on southern California landscapes. Applying this model with historical fire frequencies shows that the Baja model is inadequate to maintain these fire-prone ecosystems and further demonstrates that fire managers in southern California are not likely to learn much from studying modern Baja California fire regimes. Further supporting this conclusion are theoretical cellular automata models of fire spread, which show that, even in systems with age dependent flammability, landscapes evolve toward a complex age mosaic with a plausible age structure only when there is a severe stopping rule that constrains fire size, and only if ignitions are saturating.
Keeley, J.E.; Zedler, P.H.
2009-01-01
We evaluate the fine-grain age patch model of fire regimes in southern California shrublands. Proponents contend that the historical condition was characterized by frequent small to moderate size, slow-moving smoldering fires, and that this regime has been disrupted by fire suppression activities that have caused unnatural fuel accumulation and anomalously large and catastrophic wildfires. A review of more than 100 19th-century newspaper reports reveals that large, high-intensity wildfires predate modern fire suppression policy, and extensive newspaper coverage plus first-hand accounts support the conclusion that the 1889 Santiago Canyon Fire was the largest fire in California history. Proponents of the fine-grain age patch model contend that even the very earliest 20th-century fires were the result of fire suppression disrupting natural fuel structure. We tested that hypothesis and found that, within the fire perimeters of two of the largest early fire events in 1919 and 1932, prior fire suppression activities were insufficient to have altered the natural fuel structure. Over the last 130 years there has been no significant change in the incidence of large fires greater than 10000 ha, consistent with the conclusion that fire suppression activities are not the cause of these fire events. Eight megafires (???50 000 ha) are recorded for the region, and half have occurred in the last five years. These burned through a mosaic of age classes, which raises doubts that accumulation of old age classes explains these events. Extreme drought is a plausible explanation for this recent rash of such events, and it is hypothesized that these are due to droughts that led to increased dead fine fuels that promoted the incidence of firebrands and spot fires. A major shortcoming of the fine-grain age patch model is that it requires age-dependent flammability of shrubland fuels, but seral stage chaparral is dominated by short-lived species that create a dense surface layer of fine fuels. Results from the Behave Plus fire model with a custom fuel module for young chaparral shows that there is sufficient dead fuel to spread fire even under relatively little winds. Empirical studies of fuel ages burned in recent fires illustrate that young fuels often comprise a major portion of burned vegetation, and there is no difference between evergreen chaparral and semi-deciduous sage scrub. It has also been argued that the present-day fire size distribution in northern Baja California is a model of the historical patterns that were present on southern California landscapes. Applying this model with historical fire frequencies shows that the Baja model is inadequate to maintain these fire-prone ecosystems and further demonstrates that fire managers in southern California are not likely to learn much from studying modern Baja California fire regimes. Further supporting this conclusion are theoretical cellular automata models of fire spread, which show that, even in systems with age dependent flammability, landscapes evolve toward a complex age mosaic with a plausible age structure only when there is a severe stopping rule that constrains fire size, and only if ignitions are saturating. ?? 2009 by the Ecological Society of America.
Sahatçiu-Meka, Vjollca; Rexhepi, Sylejman; Manxhuka-Kerliu, Suzana; Pallaska, Kelmend; Murtezani, Ardiana; Osmani-Vllasolli, Teuta; Rexhepi, Mjellma; Rexhepi, Blerta
2015-01-01
The purpose of this study was to explore the relationship between disability status and duration of morning stiffness in hands with regard to age, level of education, and gender in patients with rheumatoid arthritis (RA). Also, the authors wanted to investigate this relationship with regard to the presence of rheumatoid factor, i.e., the serological status. A retrospective study was conducted in 250 patients with the classic form of RA (186 females, s64 males, mean age Xb = 49.96 y ears, range 25-60 years, disease duration 1-27 years, Xb = 6.41) previously diagnosed with RA according to the ACR (American College of Rheumatology 1987 criteria). All patients were in Steinbrocker functional classes II and III. The probability level was expressed by p < 0.01 and p < 0.05. The relationship between the variables was measured by point-biserial correlation. The correlation between duration of morning stiffness and functional class was positive but low [(r = 0.10, y = 0.00x + 2.37, p > 0.05) seronegative, (r = 0.12, y = 0.00x + 2.30, p > 0.05) seropositive]. High positive values were obtained for the linear correlation coefficient between duration of the disease and functional class (p < 0.01). Also, high values were obtained regarding the coefficient of correlation between age and functional class [(r = 0.29, p < 0.01) seronegative, (r = 0.47, p < 0.01) seropositive]. Uneducated patients were significantly more represented in functional class III [ 23 (50%) seronegative, 19 (42.2%) seropositive] than in functional class II [16 (20.3%) seronegative, 22 (27.5%) seropositive]. In conclusion, in this study of patients with rheumatoid arthritis, increased duration of morning stiffness was associated with functional disability. Functional disability increased with the duration of the disease, depended on age and educational level, and was more pronounced in older age, regardless of RA serological status. With regard to serological status and sex, the differences were non-significant.
Wodtke, Geoffrey T.
2016-01-01
This study investigates changes in the American class structure—defined in terms of workplace ownership and authority relations—and trends in status group disparities in class attainment from 1972 to 2010. Although theory and prior research suggest a variety of appreciable changes in class structure and class attainment, data from the General Social Survey indicate that the sizes of different classes remained fairly stable during this time period and that status group disparities in access to ownership and authority persisted largely intact. The 1970s witnessed a decline in the proportion of workers and growth in the proportion of managers and proprietors, but these trends reversed in the 1980s. As a result, by the late 2000s, the ownership and authority structure of the U.S. economy closely resembled that of the early 1970s. Racial and gender disparities in class attainment also did not change significantly over time: blacks and women remained underrepresented (relative to whites and men) in positions of ownership and authority throughout this period. Even after controlling for an extensive set of human capital characteristics, family constraints, and structural economic factors, there is little evidence of status group integration across these key dimensions of economic power. PMID:27134335
Zammit, Andrea R; Hall, Charles B; Lipton, Richard B; Katz, Mindy J; Muniz-Terrera, Graciela
2018-05-01
The aim of this study was to identify natural subgroups of older adults based on cognitive performance, and to establish each subgroup's characteristics based on demographic factors, physical function, psychosocial well-being, and comorbidity. We applied latent class (LC) modeling to identify subgroups in baseline assessments of 1345 Einstein Aging Study (EAS) participants free of dementia. The EAS is a community-dwelling cohort study of 70+ year-old adults living in the Bronx, NY. We used 10 neurocognitive tests and 3 covariates (age, sex, education) to identify latent subgroups. We used goodness-of-fit statistics to identify the optimal class solution and assess model adequacy. We also validated our model using two-fold split-half cross-validation. The sample had a mean age of 78.0 (SD=5.4) and a mean of 13.6 years of education (SD=3.5). A 9-class solution based on cognitive performance at baseline was the best-fitting model. We characterized the 9 identified classes as (i) disadvantaged, (ii) poor language, (iii) poor episodic memory and fluency, (iv) poor processing speed and executive function, (v) low average, (vi) high average, (vii) average, (viii) poor executive and poor working memory, (ix) elite. The cross validation indicated stable class assignment with the exception of the average and high average classes. LC modeling in a community sample of older adults revealed 9 cognitive subgroups. Assignment of subgroups was reliable and associated with external validators. Future work will test the predictive validity of these groups for outcomes such as Alzheimer's disease, vascular dementia and death, as well as markers of biological pathways that contribute to cognitive decline. (JINS, 2018, 24, 511-523).
Aging: It's Interpersonal! Reflections From Two Life Course Migrants.
Hagestad, Gunhild O; Settersten, Richard A
2017-02-01
We start with the observation that aging gerontologists often engage in two distinct discourses on aging-one public and one private. This separation entails "othering," which reproduces agism and stigma. Based on personal experience, insight from colleagues and writers, and concepts from symbolic interaction perspectives, we argue that becoming old to some degree involves becoming a stranger. Before reaching old age, both of us have been in the position of strangers due to social experiences that left us "off the line" or "on the margins." Examples are crossing social borders related to nations, class structures, gender, race, health status, and generations. Our stories illustrate how aging is more than personal. It is interpersonal-shaped by social history, policies, interdependence in relationships, and the precariousness of old age. Such phenomena often show sharp contrasts in the interpersonal worlds and social experiences of women and men. Reflecting on our own journeys as life course migrants leaves us acutely aware of both the social problems and potential promises of aging. © The Author 2016. 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.
Cytoprotective Polyphenols Against Chronological Skin Aging and Cutaneous Photodamage.
Davinelli, Sergio; Bertoglio, Juan Carlos; Polimeni, Ascanio; Scapagnini, Giovanni
2018-01-01
Skin aging is a complex biological process influenced by a combination of intrinsic and extrinsic factors, leading to cumulative alterations of skin structure, function and appearance. Polyphenols, which are secondary plant metabolites, represent one of the largest classes of compounds used in dermatology and nutricosmetics to combat skin aging. The main objective is to provide an overview of the existing literature linking skin aging and the ability of polyphenols as regulatory elements able to maintain skin homeostasis. In this review, we discuss recent progress in understanding the molecular bases of skin aging, with specific emphasis on some well known and extensively studied polyphenols which have significant anti-aging influences and photoprotective effects. Although no relevant clinical data exist and standard delivery systems have not been established, promising results have been obtained in many in vitro and animal models. A wide variety of polyphenols may minimize mechanisms underlying the functional manifestations of photoaging and chronological skin aging. Polyphenols exert their influence mostly through their antioxidant and anti-inflammatory effects, thereby abrogating collagen degradation and/or increasing procollagen synthesis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
ERIC Educational Resources Information Center
Useem, Michael
1981-01-01
Discusses how social class origins of age-eligible men have affected their likelihood of being drafted into military service since the Civil War. Holds that class bias in any future system must be considered a major social cost accompanying the revival of conscription. (Author/GC)
Topological phonon modes in filamentary structures
NASA Astrophysics Data System (ADS)
Berg, Nina; Joel, Kira; Koolyk, Miriam; Prodan, Emil
2011-02-01
This work describes a class of topological phonon modes, that is, mechanical vibrations localized at the edges of special structures that are robust against the deformations of the structures. A class of topological phonons was recently found in two-dimensional structures similar to that of microtubules. The present work introduces another class of topological phonons, this time occurring in quasi-one-dimensional filamentary structures with inversion symmetry. The phenomenon is exemplified using a structure inspired from that of actin microfilaments, present in most live cells. The system discussed here is probably the simplest structure that supports topological phonon modes, a fact that allows detailed analysis in both time and frequency domains. We advance the hypothesis that the topological phonon modes are ubiquitous in the biological world and that living organisms make use of them during various processes.
Wood, Natasha; Bann, David; Hardy, Rebecca; Gale, Catharine; Goodman, Alissa; Crawford, Claire; Stafford, Mai
2017-01-01
There is much evidence showing that childhood socioeconomic position is associated with physical health in adulthood; however existing evidence on how early life disadvantage is associated with adult mental wellbeing is inconsistent. This paper investigated whether childhood socioeconomic position (SEP) is associated with adult mental wellbeing and to what extent any association is explained by adult SEP using harmonised data from four British birth cohort studies. The sample comprised 20,717 participants with mental wellbeing data in the Hertfordshire Cohort Study (HCS), the MRC National Survey of Health and Development (NSHD), the National Child Development Study (NCDS), and the British Cohort Study (BCS70). Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) scores at age 73 (HCS), 60-64 (NSHD), 50 (NCDS), or 42 (BCS70) were used. Harmonised socioeconomic position (Registrar General's Social Classification) was ascertained in childhood (age 10/11) and adulthood (age 42/43). Associations between childhood SEP, adult SEP, and wellbeing were tested using linear regression and multi-group structural equation models. More advantaged father's social class was associated with better adult mental wellbeing in the BCS70 and the NCDS. This association was independent of adult SEP in the BCS70 but fully mediated by adult SEP in the NCDS. There was no evidence of an association between father's social class and adult mental wellbeing in the HCS or the NSHD. Socioeconomic conditions in childhood are directly and indirectly, through adult socioeconomic pathways, associated with adult mental wellbeing, but findings from these harmonised data suggest this association may depend on cohort or age.
Mechanical properties of geopolymer lightweight brick with styrofoam pellet
NASA Astrophysics Data System (ADS)
Abdullah, Mohd Mustafa Al Bakri; Tahir, Muhammad Faheem Mohd; Kadir, Aeslina Abdul; Hussin, Kamarudin; Samson, W. Saiful Iskandar W.
2017-09-01
The utilization of fly ash in brick as partial replacement of cement is gaining immense importance today, mainly on account of the improvement in the long-term durability of brick combined with ecological benefits. In this research, the lightweight brick was produced by using fly ash (class F) as a main material to replace Ordinary Portland Cement (OPC) in the composition of brick. Class F Fly Ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and styrofoam pellet was added to the geopolymer mixture to produce lightweight brick. The brick was prepared in two methods that is wet method and dry method due to different brick composition which is dry method for composition with sand and wet method for composition without sand. The bricks were cured in room temperature at 7 aging days. After 7 days, the compressive strength, water absorption, and density of the brick were investigated, where the optimum ratio for the best bricks has been determined from the lightweight density and has compressive strength more than minimum standard requirement. The best bricks are further produce for curing at 60°C in oven at 28 aging days. Those bricks also were characterized using optical microscope to measure the distribution of styrofoam in brick structure. From the result obtained, the brick that cured at 60°C in oven at 28 aging days has high strength compare to brick that cured in room temperature and at 7 day cured. The water absorption is decreasing as the curing temperature and aging days increased whereas density is increasing.
Health selection operating between classes and across employment statuses.
Ki, Myung; Sacker, Amanda; Kelly, Yvonne; Nazroo, James
2011-12-01
The debate on health selection which describes the influence of health on subsequent social mobility is highly contested. The authors set out to examine the effect of health selection by looking at the effect of previous health status on changes in socio-economic position (SEP) over two time periods. Data were pooled from 13 waves (1991-2003) of the British Household Panel Survey (BHPS). Using a multilevel multinomial approach, the presence of health selection between classes and into/out of employment was concurrently tested and compared. In the descriptive analysis, poor health was consistently associated with moving downward, while the outcome was inverse for upward movement. After accounting for the data structure using multilevel analysis, health was a predictor for social mobility when leaving and entering employment, but the effect was minimal for transitions between classes for both men and women. The non-significant impact of health on mobility inside employment may reflect the presence of the significant impact of health on mobility between employment and non-employment. This implies that the effect of health was not evenly spread over all social mobility, but rather tends to concentrate on some types of mobility. The effect of each predictor on social mobility is more concentrated among specific transitions, and health and age were likely to be substantial in moving into/out of the labour force, whereas education was a relevant predictor for mobility into/out of upper classes, in particular, classes I/II.
The first crystal structures of a family 19 class IV chitinase: the enzyme from Norway spruce.
Ubhayasekera, Wimal; Rawat, Reetika; Ho, Sharon Wing Tak; Wiweger, Malgorzata; Von Arnold, Sara; Chye, Mee-Len; Mowbray, Sherry L
2009-10-01
Chitinases help plants defend themselves against fungal attack, and play roles in other processes, including development. The catalytic modules of most plant chitinases belong to glycoside hydrolase family 19. We report here x-ray structures of such a module from a Norway spruce enzyme, the first for any family 19 class IV chitinase. The bi-lobed structure has a wide cleft lined by conserved residues; the most interesting for catalysis are Glu113, the proton donor, and Glu122, believed to be a general base that activate a catalytic water molecule. Comparisons to class I and II enzymes show that loop deletions in the class IV proteins make the catalytic cleft shorter and wider; from modeling studies, it is predicted that only three N-acetylglucosamine-binding subsites exist in class IV. Further, the structural comparisons suggest that the family 19 enzymes become more closed on substrate binding. Attempts to solve the structure of the complete protein including the associated chitin-binding module failed, however, modeling studies based on close relatives indicate that the binding module recognizes at most three N-acetylglucosamine units. The combined results suggest that the class IV enzymes are optimized for shorter substrates than the class I and II enzymes, or alternatively, that they are better suited for action on substrates where only small regions of chitin chain are accessible. Intact spruce chitinase is shown to possess antifungal activity, which requires the binding module; removing this module had no effect on measured chitinase activity.
Plasma biochemistry RIs and age effect in European Strigiformes.
Agusti Montolio, Susana; Cuenca Valera, Rafaela; Lavín González, Santiago; Cray, Carolyn; Molina López, Rafael; Ferron, Emmanuel Serrano; Francisco, Olga Nicolás; Marco Sánchez, Ignasi; Casas-Díaz, Encarna
2018-03-01
Blood biochemistry and hematology are essential in the laboratory diagnosis of disease. In Strigiformes, little information regarding reference values and influence of different preanalytic factors is available, while age is known to have an effect on some biochemistry analytes, especially in early life characterized by a rapid growth rate and increase in body mass. The objective of this study was to determine baseline data for 29 blood biochemistry variables in 5 species of Iberian Strigiformes assigned to different age classes. Healthy nocturnal birds living in wildlife health centers of Catalonia, Northeastern Spain were assigned to different age classes (chicks, juveniles, adults where possible and available) and their blood was collected and analyzed for different standard biochemistry variables. Species included Tawny owls, Little owls, Long-eared owls, Scop owls, and Barn owls. A total of 276 clinically healthy animals were sampled, including between 179 chicks, 52 juveniles, and 45 adults. The RIs of cholesterol, albumin, and osmolality were the only variables that did not show interspecific variability. Common trends between age class groups were observed in 4 species. Phosphorus and calcium concentrations and ALP activities decreased with increasing age, while concentrations of sodium and γ-globulins tended to increase in the Strigidae family. Differences were concentrated in chicks and no differences were observed between juveniles and adults in any variable. Our results demonstrate the importance of defining biochemical RIs specific for certain age classes. © 2018 American Society for Veterinary Clinical Pathology.
ERIC Educational Resources Information Center
Ostrowski, Patricia Maslin
Many schools across the United States have created a new grade between kindergarten and first grade, called transition classes, to deal with low-achieving kindergarten and first-grade students. Upon completion of the transition class, students return to a regular class, where they usually remain a year behind their age cohorts. This paper presents…
Varje, Pekka; Kouvonen, Anne; Kokkinen, Lauri; Koskinen, Aki; Väänänen, Ari
2018-02-01
This study aimed to examine the long-term changes and socioeconomic disparities in hospitalization for affective and neurotic disorders among the Finnish working-age population from 1976 to 2010. Register-based study, consisting of a 5-year follow-up of 3,223,624 Finnish working-age (18-64-year old) individuals in seven consecutive cohorts. We calculated the hazard ratios of psychiatric hospitalization for different occupational classes using Cox regression models. The risk of hospitalization for affective and neurotic disorders increased in all occupational classes after the economic recession in the 1990s, and then decreased in the 2000s. Before the 2000s, the risk was the highest among manual workers. In the 2000s the disparities between upper-level non-manual employees and other occupational classes increased. Hospitalization rates remained high among female manual workers and non-manual lower-level employees. This study revealed important similarities and differences between occupational classes in terms of long-term changes in hospitalization for affective and neurotic disorders. The results suggest that the labor market changes and healthcare reforms during the 1990s and 2000s in Finland have been more beneficial for higher than for lower occupational classes.
Age, academic performance, and stimulant prescribing for ADHD: a nationwide cohort study.
Zoëga, Helga; Valdimarsdóttir, Unnur A; Hernández-Díaz, Sonia
2012-12-01
We evaluated whether younger age in class is associated with poorer academic performance and an increased risk of being prescribed stimulants for attention-deficit/hyperactivity disorder (ADHD). This was a nationwide population-based cohort study, linking data from national registries of prescribed drugs and standardized scholastic examinations. The study population comprised all children born in 1994-1996 who took standardized tests in Iceland at ages 9 and 12 (n = 11 785). We estimated risks of receiving low test scores (0-10th percentile) and being prescribed stimulants for ADHD. Comparisons were made according to children's relative age in class. Mean test scores in mathematics and language arts were lowest among the youngest children in the fourth grade, although the gap attenuated in the seventh grade. Compared with the oldest third, those in the youngest third of class had an increased relative risk of receiving a low test score at age 9 for mathematics (1.9; 95% confidence interval [CI] 1.6-2.2) and language arts (1.8; 95% CI 1.6-2.1), whereas at age 12, the relative risk was 1.6 in both subjects. Children in the youngest third of class were 50% more likely (1.5; 95% CI 1.3-1.8) than those in the oldest third to be prescribed stimulants between ages 7 and 14. Relative age among classmates affects children's academic performance into puberty, as well as their risk of being prescribed stimulants for ADHD. This should be taken into account when evaluating children's performance and behavior in school to prevent unnecessary stimulant treatment.
Feichtinger, Philip; Höner, Oliver
2015-01-01
Adolescence is regarded as a key developmental phase in the course of talented football players' careers. The present study focuses on early adolescent players' development of achievement motives, volitional components, and self-referential cognitions. Based on the multidimensional and dynamic nature of talent, the development of multifaceted personality characteristics is an important issue in the context of sports talent research. According to previous findings in psychology, personality characteristics' development is defined by both stability and change, and the current study analyses four different types: differential stability (I), mean-level change (II), individual-level change (III), and structural stability (IV). The sample consists of 151 male players in the talent development programme of the German Football Association. Psychological diagnostics of the personality characteristics are implemented across longitudinal sections over a time period of three seasons, from the U12 to U14 age classes. The results reveal that the personality characteristics show (I) moderate test-retest correlations over one-year intervals (.43 ≤ rtt ≤ .62), and lower coefficients for a two-year period (.26 ≤ rtt ≤ .53). (II) Most of the personality characteristics' mean values differ significantly across the age classes with small effect sizes (.01 ≤ [Formula: see text] ≤ .03). (III) Only minor individual-level changes in the football players' development are found. (IV) The personality characteristics' associations within a two-factor structure do not stay invariant over time. From the results of the present study, conclusions are drawn regarding the talent identification and development process.
Unimodularity criteria for Poisson structures on foliated manifolds
NASA Astrophysics Data System (ADS)
Pedroza, Andrés; Velasco-Barreras, Eduardo; Vorobiev, Yury
2018-03-01
We study the behavior of the modular class of an orientable Poisson manifold and formulate some unimodularity criteria in the semilocal context, around a (singular) symplectic leaf. Our results generalize some known unimodularity criteria for regular Poisson manifolds related to the notion of the Reeb class. In particular, we show that the unimodularity of the transverse Poisson structure of the leaf is a necessary condition for the semilocal unimodular property. Our main tool is an explicit formula for a bigraded decomposition of modular vector fields of a coupling Poisson structure on a foliated manifold. Moreover, we also exploit the notion of the modular class of a Poisson foliation and its relationship with the Reeb class.
Lande, Russell; Engen, Steinar; Sæther, Bernt-Erik
2017-10-31
We analyze the stochastic demography and evolution of a density-dependent age- (or stage-) structured population in a fluctuating environment. A positive linear combination of age classes (e.g., weighted by body mass) is assumed to act as the single variable of population size, [Formula: see text], exerting density dependence on age-specific vital rates through an increasing function of population size. The environment fluctuates in a stationary distribution with no autocorrelation. We show by analysis and simulation of age structure, under assumptions often met by vertebrate populations, that the stochastic dynamics of population size can be accurately approximated by a univariate model governed by three key demographic parameters: the intrinsic rate of increase and carrying capacity in the average environment, [Formula: see text] and [Formula: see text], and the environmental variance in population growth rate, [Formula: see text] Allowing these parameters to be genetically variable and to evolve, but assuming that a fourth parameter, [Formula: see text], measuring the nonlinearity of density dependence, remains constant, the expected evolution maximizes [Formula: see text] This shows that the magnitude of environmental stochasticity governs the classical trade-off between selection for higher [Formula: see text] versus higher [Formula: see text] However, selection also acts to decrease [Formula: see text], so the simple life-history trade-off between [Formula: see text]- and [Formula: see text]-selection may be obscured by additional trade-offs between them and [Formula: see text] Under the classical logistic model of population growth with linear density dependence ([Formula: see text]), life-history evolution in a fluctuating environment tends to maximize the average population size. Published under the PNAS license.
ERIC Educational Resources Information Center
Flores, Jairo; Salguero, Alfonso; Marquez, Sara
2008-01-01
This study examined the relationships of achievement goal orientations and perceptions of the motivational climate in physical education classes among Colombian students, and tested gender and age differences in goal orientations and perceived motivational climate. Participants (1378 boys and 1615 girls, ranging in age from 9 to 18 yr) completed…
ERIC Educational Resources Information Center
Stefanek, Elisabeth; Strohmeier, Dagmar; van de Schoot, Rens
2015-01-01
This study was an investigation of individual and contextual predictors for same-cultural friendship preferences among non-immigrant (N = 125), Turkish (N = 196) and former Yugoslavian (N = 256) immigrant youths (M age = 14.39 years) in 36 multicultural classes. At the individual level age, gender, cultural group, number of friends, and…
"Special Educational Needs" of the Elderly: A Trap for the Unwary? Research Study.
ERIC Educational Resources Information Center
Ageing International, 1989
1989-01-01
A British study of mainstreamed and special needs classes for older adults found that the special education approach encourages a narrow perspective of aging and an emphasis on disability. At Simon Fraser University, a certificate program for senior citizens determined that seniors like age-integrated classes and instructors need training in…
Mbizah, Moreangels M; Steenkamp, Gerhard; Groom, Rosemary J
2016-01-01
African wild dogs (Lycaon pictus) are endangered and their population continues to decline throughout their range. Given their conservation status, more research focused on their population dynamics, population growth and age specific mortality is needed and this requires reliable estimates of age and age of mortality. Various age determination methods from teeth and skull measurements have been applied in numerous studies and it is fundamental to test the validity of these methods and their applicability to different species. In this study we assessed the accuracy of estimating chronological age and age class of African wild dogs, from dental age measured by (i) counting cementum annuli (ii) pulp cavity/tooth width ratio, (iii) tooth wear (measured by tooth crown height) (iv) tooth wear (measured by tooth crown width/crown height ratio) (v) tooth weight and (vi) skull measurements (length, width and height). A sample of 29 African wild dog skulls, from opportunistically located carcasses was analysed. Linear and ordinal regression analysis was done to investigate the performance of each of the six age determination methods in predicting wild dog chronological age and age class. Counting cementum annuli was the most accurate method for estimating chronological age of wild dogs with a 79% predictive capacity, while pulp cavity/tooth width ratio was also a reliable method with a 68% predictive capacity. Counting cementum annuli and pulp cavity/tooth width ratio were again the most accurate methods for separating wild dogs into three age classes (6-24 months; 25-60 months and > 60 months), with a McFadden's Pseudo-R2 of 0.705 and 0.412 respectively. The use of the cementum annuli method is recommended when estimating age of wild dogs since it is the most reliable method. However, its use is limited as it requires tooth extraction and shipping, is time consuming and expensive, and is not applicable to living individuals. Pulp cavity/tooth width ratio is a moderately reliable method for estimating both chronological age and age class. This method gives a balance between accuracy, cost and practicability, therefore it is recommended when precise age estimations are not paramount.
Steenkamp, Gerhard; Groom, Rosemary J.
2016-01-01
African wild dogs (Lycaon pictus) are endangered and their population continues to decline throughout their range. Given their conservation status, more research focused on their population dynamics, population growth and age specific mortality is needed and this requires reliable estimates of age and age of mortality. Various age determination methods from teeth and skull measurements have been applied in numerous studies and it is fundamental to test the validity of these methods and their applicability to different species. In this study we assessed the accuracy of estimating chronological age and age class of African wild dogs, from dental age measured by (i) counting cementum annuli (ii) pulp cavity/tooth width ratio, (iii) tooth wear (measured by tooth crown height) (iv) tooth wear (measured by tooth crown width/crown height ratio) (v) tooth weight and (vi) skull measurements (length, width and height). A sample of 29 African wild dog skulls, from opportunistically located carcasses was analysed. Linear and ordinal regression analysis was done to investigate the performance of each of the six age determination methods in predicting wild dog chronological age and age class. Counting cementum annuli was the most accurate method for estimating chronological age of wild dogs with a 79% predictive capacity, while pulp cavity/tooth width ratio was also a reliable method with a 68% predictive capacity. Counting cementum annuli and pulp cavity/tooth width ratio were again the most accurate methods for separating wild dogs into three age classes (6–24 months; 25–60 months and > 60 months), with a McFadden’s Pseudo-R2 of 0.705 and 0.412 respectively. The use of the cementum annuli method is recommended when estimating age of wild dogs since it is the most reliable method. However, its use is limited as it requires tooth extraction and shipping, is time consuming and expensive, and is not applicable to living individuals. Pulp cavity/tooth width ratio is a moderately reliable method for estimating both chronological age and age class. This method gives a balance between accuracy, cost and practicability, therefore it is recommended when precise age estimations are not paramount. PMID:27732663
Influence of artificial aging in marginal adaptation of mixed class V cavities.
Tonetto, Mateus Rodrigues; Bandéca, Matheus Coelho; Barud, Hélida Gomes de Oliveira; Pinto, Shelon Cristina Souza; Lima, Darlon Martins; Borges, Alvaro Henrique; de Campos, Edson Alves; de Andrade, Marcelo Ferrarezi
2013-03-01
The aim of this study was to investigate whether the artificial aging by thermal cycling had influenced the marginal adaptation of class V restorations with/without chlorhexidine application in the bond process. Twelve intact human third molars were used. Class V cavity preparations were performed on the buccal surface and the teeth received 35% phosphoric acid-etching procedure (Ultradent Products Inc., South Jordan, Utah, USA). Subsequently, the samples were divided in two groups: Untreated acid-etched dentin and chlorhexidine application as an adjunct in the bond process. The adhesive Single Bond 2 (3M ESPE, St. Paul, MN, USA) was used after 2% chlorhexidine application, and the restorations were performed with Filtek™ Z350 XT (3M ESPE) composite resin. The specimens were submitted to artificial aging by thermal cycling with 3,000 cycles. Analyzes were performed on scanning electron microscopy using replicas of marginal adaptation in percentage of continuous margin before and after the artificial aging. The data were analyzed by paired test and the results showed statistically significant differences in the percentage of continuous margin with/without chlorhexidine treatment before and after thermal cycling. This study concluded that the artificial aging by thermal cycling influenced the marginal adaptation of mixed class V composite restorations.
The 'robust' capture-recapture design allows components of recruitment to be estimated
Pollock, K.H.; Kendall, W.L.; Nichols, J.D.; Lebreton, J.-D.; North, P.M.
1993-01-01
The 'robust' capture-recapture design (Pollock 1982) allows analyses which combine features of closed population model analyses (Otis et aI., 1978, White et aI., 1982) and open population model analyses (Pollock et aI., 1990). Estimators obtained under these analyses are more robust to unequal catch ability than traditional Jolly-Seber estimators (Pollock, 1982; Pollock et al., 1990; Kendall, 1992). The robust design also allows estimation of parameters for population size, survival rate and recruitment numbers for all periods of the study unlike under Jolly-Seber type models. The major advantage of this design that we emphasize in this short review paper is that it allows separate estimation of immigration and in situ recruitment numbers for a two or more age class model (Nichols and Pollock, 1990). This is contrasted with the age-dependent Jolly-Seber model (Pollock, 1981; Stokes, 1984; Pollock et L, 1990) which provides separate estimates for immigration and in situ recruitment for all but the first two age classes where there is at least a three age class model. The ability to achieve this separation of recruitment components can be very important to population modelers and wildlife managers as many species can only be separated into two easily identified age classes in the field.
ERIC Educational Resources Information Center
Hammig, Bart; Ogletree, Roberta; Wycoff-Horn, Marcie R.
2011-01-01
Background: The aim of the present study was to examine the impact of professional preparation and class structure on health content delivery and time spent delivering content among required health education classes in the United States. Methods: Data from the classroom-level file of the 2006 School Health Policies and Programs Study were…
Schuetz, Anja; Min, Jinrong; Allali-Hassani, Abdellah; Schapira, Matthieu; Shuen, Michael; Loppnau, Peter; Mazitschek, Ralph; Kwiatkowski, Nick P.; Lewis, Timothy A.; Maglathin, Rebecca L.; McLean, Thomas H.; Bochkarev, Alexey; Plotnikov, Alexander N.; Vedadi, Masoud; Arrowsmith, Cheryl H.
2008-01-01
Histone deacetylases (HDACs) are protein deacetylases that play a role in repression of gene transcription and are emerging targets in cancer therapy. Here, we characterize the structure and enzymatic activity of the catalytic domain of human HDAC7 (cdHDAC7). Although HDAC7 normally exists as part of a multiprotein complex, we show that cdHDAC7 has a low level of deacetylase activity which can be inhibited by known HDAC inhibitors. The crystal structures of human cdHDAC7 and its complexes with two hydroxamate inhibitors are the first structures of the catalytic domain of class IIa HDACs and demonstrate significant differences with previously reported class I and class IIb-like HDAC structures. We show that cdHDAC7 has an additional class IIa HDAC-specific zinc binding motif adjacent to the active site which is likely to participate in substrate recognition and protein-protein interaction and may provide a site for modulation of activity. Furthermore, a different active site topology results in modified catalytic properties and in an enlarged active site pocket. Our studies provide mechanistic insights into class IIa HDACs and facilitate the design of specific modulators. PMID:18285338
Barik, Sailen
2017-12-01
A significant number of proteins in all living species contains amino acid repeats (AARs) of various lengths and compositions, many of which play important roles in protein structure and function. Here, I have surveyed select homopolymeric single [(A)n] and double [(AB)n] AARs in the human proteome. A close examination of their codon pattern and analysis of RNA structure propensity led to the following set of empirical rules: (1) One class of amino acid repeats (Class I) uses a mixture of synonymous codons, some of which approximate the codon bias ratio in the overall human proteome; (2) The second class (Class II) disregards the codon bias ratio, and appears to have originated by simple repetition of the same codon (or just a few codons); and finally, (3) In all AARs (including Class I, Class II, and the in-betweens), the codons are chosen in a manner that precludes the formation of RNA secondary structure. It appears that the AAR genes have evolved by orchestrating a balance between codon usage and mRNA secondary structure. The insights gained here should provide a better understanding of AAR evolution and may assist in designing synthetic genes.
Schuetz, Anja; Min, Jinrong; Allali-Hassani, Abdellah; Schapira, Matthieu; Shuen, Michael; Loppnau, Peter; Mazitschek, Ralph; Kwiatkowski, Nick P; Lewis, Timothy A; Maglathin, Rebecca L; McLean, Thomas H; Bochkarev, Alexey; Plotnikov, Alexander N; Vedadi, Masoud; Arrowsmith, Cheryl H
2008-04-25
Histone deacetylases (HDACs) are protein deacetylases that play a role in repression of gene transcription and are emerging targets in cancer therapy. Here, we characterize the structure and enzymatic activity of the catalytic domain of human HDAC7 (cdHDAC7). Although HDAC7 normally exists as part of a multiprotein complex, we show that cdHDAC7 has a low level of deacetylase activity which can be inhibited by known HDAC inhibitors. The crystal structures of human cdHDAC7 and its complexes with two hydroxamate inhibitors are the first structures of the catalytic domain of class IIa HDACs and demonstrate significant differences with previously reported class I and class IIb-like HDAC structures. We show that cdHDAC7 has an additional class IIa HDAC-specific zinc binding motif adjacent to the active site which is likely to participate in substrate recognition and protein-protein interaction and may provide a site for modulation of activity. Furthermore, a different active site topology results in modified catalytic properties and in an enlarged active site pocket. Our studies provide mechanistic insights into class IIa HDACs and facilitate the design of specific modulators.
NASA Astrophysics Data System (ADS)
Petrillo, M.; Cherubini, P.; Fravolini, G.; Ascher, J.; Schärer, M.; Synal, H.-A.; Bertoldi, D.; Camin, F.; Larcher, R.; Egli, M.
2015-09-01
Due to the large size and highly heterogeneous spatial distribution of deadwood, the time scales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests have been poorly investigated and are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the five-decay class system commonly employed for forest surveys, based on a macromorphological and visual assessment. For the decay classes 1 to 3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) and some others not having enough tree rings, radiocarbon dating was used. In addition, density, cellulose and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model. In the decay classes 1 to 3, the ages of the CWD were similar varying between 1 and 54 years for spruce and 3 and 40 years for larch with no significant differences between the classes; classes 1-3 are therefore not indicative for deadwood age. We found, however, distinct tree species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were 0.012 to 0.018 yr-1 for spruce and 0.005 to 0.012 yr-1 for larch. Cellulose and lignin time trends half-lives (using a multiple-exponential model) could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 yr for spruce and 50 yr for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chang, C.; Coggill, P.; Bateman, A.
Many Gram-positive lactic acid bacteria (LAB) produce anti-bacterial peptides and small proteins called bacteriocins, which enable them to compete against other bacteria in the environment. These peptides fall structurally into three different classes, I, II, III, with class IIa being pediocin-like single entities and class IIb being two-peptide bacteriocins. Self-protective cognate immunity proteins are usually co-transcribed with these toxins. Several examples of cognates for IIa have already been solved structurally. Streptococcus pyogenes, closely related to LAB, is one of the most common human pathogens, so knowledge of how it competes against other LAB species is likely to prove invaluable. Wemore » have solved the crystal structure of the gene-product of locus Spy-2152 from S. pyogenes, (PDB: 2fu2), and found it to comprise an anti-parallel four-helix bundle that is structurally similar to other bacteriocin immunity proteins. Sequence analyses indicate this protein to be a possible immunity protein protective against class IIa or IIb bacteriocins. However, given that S. pyogenes appears to lack any IIa pediocin-like proteins but does possess class IIb bacteriocins, we suggest this protein confers immunity to IIb-like peptides. Combined structural, genomic and proteomic analyses have allowed the identification and in silico characterization of a new putative immunity protein from S. pyogenes, possibly the first structure of an immunity protein protective against potential class IIb two-peptide bacteriocins. We have named the two pairs of putative bacteriocins found in S. pyogenes pyogenecin 1, 2, 3 and 4.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yarrow, M.N.
1982-01-01
This study explores how working-class people apprehend and analyze the class dynamics of their social world. As an exploratory empirical study of the structure and dynamics of working-class consciousness, it seeks to develop the theory of actual class consciousness by bringing previous theories into dialogue with the articulated analyses of coal miners in central Appalachia. Although changing conditions are shown to have a powerful effect on class consciousness, the respondents were found to respond differently to the changing context and to remain loyal to important elements of their earlier perspectives. Suggestions are made for how the theory could be developedmore » further. The data for the study are flexibly structured interviews which were conducted with active, retired, and disabled miners in southern West Virginia and western Virginia. A dozen miners were interviewed during the 1978 strike and again the following summer; during the summer of 1978, nineteen additional miners were interviewed.« less
Evaluation of reforested areas using LANDSAT imagery
NASA Technical Reports Server (NTRS)
Dejesusparada, N. (Principal Investigator); Filho, P. H.; Shimabukuro, Y. E.
1978-01-01
The author has identified the following significant results. Visual and automatic interpretation of LANDSAT imagery was used to classify the general Pinus and Eucalyptus according to their age and species. A methodology was derived, based on training areas, to define the legend and spectral characteristics of the analyzed classes. Imager analysis of the training areas show that Pinus taeda is separable from the other Pinus species based on JM distance measurement. No difference of JM measurements was observed among Eucalyptus species. Two classes of Eucalyptus were separated according to their ages: those under and those over two years of age. Channel 6 and 7 were suitable for the discrimination of the reforested classes. Channel 5 was efficient to separated reforested areas from nonforested targets in the region. The automatic analysis shows the highest classification precision was obtained for Eucalyptus over two years of age (95.12 percent).
Influence of homology and node age on the growth of protein-protein interaction networks
NASA Astrophysics Data System (ADS)
Bottinelli, Arianna; Bassetti, Bruno; Lagomarsino, Marco Cosentino; Gherardi, Marco
2012-10-01
Proteins participating in a protein-protein interaction network can be grouped into homology classes following their common ancestry. Proteins added to the network correspond to genes added to the classes, so the dynamics of the two objects are intrinsically linked. Here we first introduce a statistical model describing the joint growth of the network and the partitioning of nodes into classes, which is studied through a combined mean-field and simulation approach. We then employ this unified framework to address the specific issue of the age dependence of protein interactions through the definition of three different node wiring or divergence schemes. A comparison with empirical data indicates that an age-dependent divergence move is necessary in order to reproduce the basic topological observables together with the age correlation between interacting nodes visible in empirical data. We also discuss the possibility of nontrivial joint partition and topology observables.
Rönnberg, Jerker; Lunner, Thomas; Ng, Elaine Hoi Ning; Lidestam, Björn; Zekveld, Adriana Agatha; Sörqvist, Patrik; Lyxell, Björn; Träff, Ulf; Yumba, Wycliffe; Classon, Elisabet; Hällgren, Mathias; Larsby, Birgitta; Signoret, Carine; Pichora-Fuller, M. Kathleen; Rudner, Mary; Danielsson, Henrik; Stenfelt, Stefan
2016-01-01
Abstract Objective: The aims of the current n200 study were to assess the structural relations between three classes of test variables (i.e. HEARING, COGNITION and aided speech-in-noise OUTCOMES) and to describe the theoretical implications of these relations for the Ease of Language Understanding (ELU) model. Study sample: Participants were 200 hard-of-hearing hearing-aid users, with a mean age of 60.8 years. Forty-three percent were females and the mean hearing threshold in the better ear was 37.4 dB HL. Design: LEVEL1 factor analyses extracted one factor per test and/or cognitive function based on a priori conceptualizations. The more abstract LEVEL 2 factor analyses were performed separately for the three classes of test variables. Results: The HEARING test variables resulted in two LEVEL 2 factors, which we labelled SENSITIVITY and TEMPORAL FINE STRUCTURE; the COGNITIVE variables in one COGNITION factor only, and OUTCOMES in two factors, NO CONTEXT and CONTEXT. COGNITION predicted the NO CONTEXT factor to a stronger extent than the CONTEXT outcome factor. TEMPORAL FINE STRUCTURE and SENSITIVITY were associated with COGNITION and all three contributed significantly and independently to especially the NO CONTEXT outcome scores (R2 = 0.40). Conclusions: All LEVEL 2 factors are important theoretically as well as for clinical assessment. PMID:27589015
Rönnberg, Jerker; Lunner, Thomas; Ng, Elaine Hoi Ning; Lidestam, Björn; Zekveld, Adriana Agatha; Sörqvist, Patrik; Lyxell, Björn; Träff, Ulf; Yumba, Wycliffe; Classon, Elisabet; Hällgren, Mathias; Larsby, Birgitta; Signoret, Carine; Pichora-Fuller, M Kathleen; Rudner, Mary; Danielsson, Henrik; Stenfelt, Stefan
2016-11-01
The aims of the current n200 study were to assess the structural relations between three classes of test variables (i.e. HEARING, COGNITION and aided speech-in-noise OUTCOMES) and to describe the theoretical implications of these relations for the Ease of Language Understanding (ELU) model. Participants were 200 hard-of-hearing hearing-aid users, with a mean age of 60.8 years. Forty-three percent were females and the mean hearing threshold in the better ear was 37.4 dB HL. LEVEL1 factor analyses extracted one factor per test and/or cognitive function based on a priori conceptualizations. The more abstract LEVEL 2 factor analyses were performed separately for the three classes of test variables. The HEARING test variables resulted in two LEVEL 2 factors, which we labelled SENSITIVITY and TEMPORAL FINE STRUCTURE; the COGNITIVE variables in one COGNITION factor only, and OUTCOMES in two factors, NO CONTEXT and CONTEXT. COGNITION predicted the NO CONTEXT factor to a stronger extent than the CONTEXT outcome factor. TEMPORAL FINE STRUCTURE and SENSITIVITY were associated with COGNITION and all three contributed significantly and independently to especially the NO CONTEXT outcome scores (R(2) = 0.40). All LEVEL 2 factors are important theoretically as well as for clinical assessment.
Lopez-Arana, S; Avendano, M; van Lenthe, F J; Burdorf, A
2014-01-01
There has been an increase in overweight among women in low- and middle-income countries but whether these trends differ for women in different occupations is unknown. We examined trends by occupational class among women from 33 low- and middle-income countries in four regions. Cross-national study with repeated cross-sectional demographic health surveys. Height and weight were assessed at least twice between 1992 and 2009 in 248,925 women aged 25-49 years. Interviews were conducted to assess occupational class, age, place of residence, educational level, household wealth index, parity, age at first birth and breastfeeding. We used logistic and linear regression analyses to assess the annual percent change in overweight (body mass index >25 kg m(-2)) by occupational class. The prevalence of overweight ranged from 2.2% in Nepal in 1992-1997 to 75% in Egypt in 2004-2009. In all the four regions, women working in agriculture had consistently lower prevalence of overweight, while women from professional, technical, managerial as well as clerical occupational classes had higher prevalence. Although the prevalence of overweight increased in all the occupational classes in most regions, women working in agriculture and production experienced the largest increase in overweight over the study period, while women in higher occupational classes experienced smaller increases. To illustrate, overweight increased annually by 0.5% in Latin America and the Caribbean and by 0.7% in Sub-Saharan Africa among women from professional, technical and managerial classes, as compared with 2.8% and 3.7%, respectively, among women in agriculture. The prevalence of overweight has increased in most low- and middle-income countries, but women working in agriculture and production have experienced larger increases than women in higher occupational classes.
Differentiation of plant age in grasses using remote sensing
NASA Astrophysics Data System (ADS)
Knox, Nichola M.; Skidmore, Andrew K.; van der Werff, Harald M. A.; Groen, Thomas A.; de Boer, Willem F.; Prins, Herbert H. T.; Kohi, Edward; Peel, Mike
2013-10-01
Phenological or plant age classification across a landscape allows for examination of micro-topographical effects on plant growth, improvement in the accuracy of species discrimination, and will improve our understanding of the spatial variation in plant growth. In this paper six vegetation indices used in phenological studies (including the newly proposed PhIX index) were analysed for their ability to statistically differentiate grasses of different ages in the sequence of their development. Spectra of grasses of different ages were collected from a greenhouse study. These were used to determine if NDVI, NDWI, CAI, EVI, EVI2 and the newly proposed PhIX index could sequentially discriminate grasses of different ages, and subsequently classify grasses into their respective age category. The PhIX index was defined as: (AVNIRn+log(ASWIR2n))/(AVNIRn-log(ASWIR2n)), where AVNIRn and ASWIR2n are the respective normalised areas under the continuum removed reflectance curve within the VNIR (500-800 nm) and SWIR2 (2000-2210 nm) regions. The PhIX index was found to produce the highest phenological classification accuracy (Overall Accuracy: 79%, and Kappa Accuracy: 75%) and similar to the NDVI, EVI and EVI2 indices it statistically sequentially separates out the developmental age classes. Discrimination between seedling and dormant age classes and the adult and flowering classes was problematic for most of the tested indices. Combining information from the visible near infrared (VNIR) and shortwave infrared region (SWIR) region into a single phenological index captures the phenological changes associated with plant pigments and the ligno-cellulose absorption feature, providing a robust method to discriminate the age classes of grasses. This work provides a valuable contribution into mapping spatial variation and monitoring plant growth across savanna and grassland ecosystems.
Mantzicopoulos, Panayota; French, Brian F; Maller, Susan J
2004-01-01
Competing models of the factorial structure of the Pictorial Scale of Perceived Competence and Social Acceptance (PSPCSA) were tested for fit using multisample confirmatory factor analysis. The best fitting model was tested for invariance (a) across samples of middle-class (n = 251) and economically disadvantaged (Head Start, n = 117) kindergarten children (whose ages ranged from 67 to 86 months), and (b) over time (at the end of preschool and kindergarten) for the Head Start sample. For kindergarten children, regardless of socioeconomic status, the factor structure of the PSPCSA was consistent with the 2-factor model of Competence and Acceptance. This model also fit reasonably well for Head Start children at the end of their preschool year. However, in addition to providing broad support for the dimensionality of the measure, our findings highlight important concerns about the PSPCSA. Copyright 2004 Society for Research in Child Development, Inc.
A Statistical Study of Rapid Sunspot Structure Change Associated with Flares
NASA Astrophysics Data System (ADS)
Chen, Wei-Zhong; Liu, Chang; Song, Hui; Deng, Na; Tan, Chang-Yi; Wang, Hai-Min
2007-10-01
We reported recently some rapid changes of sunspot structure in white-light (WL) associated with major flares. We extend the study to smaller events and present here results of a statistical study of this phenomenon. In total, we investigate 403 events from 1998 May 9 to 2004 July 17, including 40 X-class, 174 M-class, and 189 C-class flares. By monitoring the structure of the flaring active regions using the WL observations from the Transition Region and Coronal Explorer (TRACE), we find that segments in the outer sunspot structure decayed rapidly right after many flares; and that, on the other hand, the central part of sunspots near the flare-associated magnetic neutral line became darkened. These rapid and permanent changes are evidenced in the time profiles of WL mean intensity and are not likely resulted from the flare emissions. Our study further shows that the outer sunspot structure decay as well as the central structure darkening are more likely to be detected in larger solar flares. For X-class flares, over 40% events show distinct sunspot structure change. For M- and C-class flares, this percentage drops to 17% and 10%, respectively. The results of this statistical study support our previously proposed reconnection picture, i.e., the flare-related magnetic fields evolve from a highly inclined to a more vertical configuration.
Childhood eczema: disease of the advantaged?
Williams, H. C.; Strachan, D. P.; Hay, R. J.
1994-01-01
OBJECTIVE--To determine whether the increased prevalence of childhood eczema in advantaged socioeconomic groups is due to increased parental reporting. DESIGN--Comparison of parental reports of eczema with visible eczema recorded by medical officers during a detailed physical examination. SETTING--National birth cohort study. SUBJECTS--8279 children from England, Wales, and Scotland born during 3-9 March 1958 and followed up at the ages of 7, 11, and 16. MAIN OUTCOME MEASURES--Prevalence of eczema according to parental report compared with medical officer's examination at the ages of 7, 11, and 16. RESULTS--Prevalence of both reported and examined eczema increased with rising social class at the ages of 7, 11, and 16 years. The point prevalence of examined eczema at age 7 was 4.8%, 3.6%, 3.6%, 2.4%, 2.2%, and 2.4% in social classes I, II, III non-manual, III manual, IV, and V respectively (chi 2 value for linear trend 12.6, P < 0.001). This trend persisted after adjustment for potential confounders such as region and family size and was not present for examined psoriasis or acne. CONCLUSIONS--Eczema is more prevalent among British schoolchildren in social classes I and II than those in lower classes. Exposures associated with social class are probably at least as important as genetic factors in the expression of childhood eczema. PMID:8173454
Getting By on the Minimum: The Lives of Working-Class Women.
ERIC Educational Resources Information Center
Johnson, Jennifer
The lives of working-class women were explored through interviews with 63 middle-aged women, most of whom were employed in working-class jobs and living working-class lives in Baltimore, Maryland. The following were among the areas covered in the interviews: the women's lives on and off the job; their job satisfaction; the reasons they work and…
Li, Liqi; Cui, Xiang; Yu, Sanjiu; Zhang, Yuan; Luo, Zhong; Yang, Hua; Zhou, Yue; Zheng, Xiaoqi
2014-01-01
Protein structure prediction is critical to functional annotation of the massively accumulated biological sequences, which prompts an imperative need for the development of high-throughput technologies. As a first and key step in protein structure prediction, protein structural class prediction becomes an increasingly challenging task. Amongst most homological-based approaches, the accuracies of protein structural class prediction are sufficiently high for high similarity datasets, but still far from being satisfactory for low similarity datasets, i.e., below 40% in pairwise sequence similarity. Therefore, we present a novel method for accurate and reliable protein structural class prediction for both high and low similarity datasets. This method is based on Support Vector Machine (SVM) in conjunction with integrated features from position-specific score matrix (PSSM), PROFEAT and Gene Ontology (GO). A feature selection approach, SVM-RFE, is also used to rank the integrated feature vectors through recursively removing the feature with the lowest ranking score. The definitive top features selected by SVM-RFE are input into the SVM engines to predict the structural class of a query protein. To validate our method, jackknife tests were applied to seven widely used benchmark datasets, reaching overall accuracies between 84.61% and 99.79%, which are significantly higher than those achieved by state-of-the-art tools. These results suggest that our method could serve as an accurate and cost-effective alternative to existing methods in protein structural classification, especially for low similarity datasets.
Belek, I
2000-02-01
The aim of this study is to determine the separate effects of social class, income, education and area of residence on psychological distress. The study also assesses whether the association between prevalence of high score on the 12-item General Health Questionnaire (GHQ 12) and social class is independent of other variables. Psychological distress was assessed by means of the GHQ 12. The study covered 1,092 adults aged 15 years or more living in two different quarters of Antalya. Social class status was defined by occupational position, with income, education and area of residence treated as confounders. Chi-square and logistic regression analyses were used to evaluate the data. Large inequalities in psychological distress by all variables were observed. Psychological distress was significantly associated with class status, after adjusting for income, education, area of residence and other potential confounders (age, sex and marital status). Class inequalities in psychological distress were observed between blue-collar workers/unqualified employees and bourgeoisie. These findings support the view that the recent widening of inequalities among social classes in Turkey pose a substantial threat to health.
Waitzman, N J; Smith, K R
1994-01-01
OBJECTIVES. This study was undertaken to examine how the interaction between occupational class transitions and race affects the incidence of hypertension. METHODS. A cohort of 1982 men (183 Black), ages 25 to 55, received a baseline medical exam between 1971 and 1975 and a follow-up between 1982 and 1984. Logistic regressions were estimated for hypertension at follow-up controlling for hypertension at baseline, other risk factors associated with blood pressure, and interaction terms identifying specific occupational class transitions among Blacks and Whites. The occupational class matrix was based largely on scores of US Census Bureau occupations from the Dictionary of Occupational Titles. RESULTS. Relative to Whites who remained in professional and technical jobs between baseline and follow-up, Blacks and Whites who remained in lower occupational classes or made specific transitions--notably into the lowest class--had significantly higher incidence rates of hypertension. These differences were greater among Blacks, who are also more concentrated in and less likely to move upward from the lower end of the occupational class matrix. CONCLUSIONS. Widening racial disparities in high blood pressure over the period of study may be partly attributable to characteristics associated with occupational class position and dynamics. PMID:8203691
Accretions Disks Around Class O Protostars: The Case of VLA 1623
NASA Astrophysics Data System (ADS)
Pudritz, Ralph E.; Wilson, Christine D.; Carlstrom, John E.; Lay, Oliver P.; Hills, Richard E.; Ward-Thompson, Derek
1996-10-01
Continuum emission at 220 and 355 GHz from the prototype class 0 source VLA 1623 has been detected using the James Clerk Maxwell Telescope-Caltech Submillimeter Observatory interferometer. Gaussian fits to the data place an upper limit of 70 AU on the half-width at half-maximum radius of the emission, which implies an upper limit of ~175 AU for the cutoff radius of the circumstellar disk in the system. In the context of existing collapse models, this disk could be magnetically supported on the largest scales and have an age of ~6 x 104 yr, consistent with previous suggestions that class 0 sources are quite young. The innermost region of the disk within ~6 AU is likely to be in centrifugal support, which is likely large enough to provide a drive for the outflow according to current theoretical models. Alternatively, if 175 AU corresponds to the centrifugal radius of the disk, the age of the system is ~2 x 105 yr, closer to age estimates for class I sources.
Local Structural Differences in Homologous Proteins: Specificities in Different SCOP Classes
Joseph, Agnel Praveen; Valadié, Hélène; Srinivasan, Narayanaswamy; de Brevern, Alexandre G.
2012-01-01
The constant increase in the number of solved protein structures is of great help in understanding the basic principles behind protein folding and evolution. 3-D structural knowledge is valuable in designing and developing methods for comparison, modelling and prediction of protein structures. These approaches for structure analysis can be directly implicated in studying protein function and for drug design. The backbone of a protein structure favours certain local conformations which include α-helices, β-strands and turns. Libraries of limited number of local conformations (Structural Alphabets) were developed in the past to obtain a useful categorization of backbone conformation. Protein Block (PB) is one such Structural Alphabet that gave a reasonable structure approximation of 0.42 Å. In this study, we use PB description of local structures to analyse conformations that are preferred sites for structural variations and insertions, among group of related folds. This knowledge can be utilized in improving tools for structure comparison that work by analysing local structure similarities. Conformational differences between homologous proteins are known to occur often in the regions comprising turns and loops. Interestingly, these differences are found to have specific preferences depending upon the structural classes of proteins. Such class-specific preferences are mainly seen in the all-β class with changes involving short helical conformations and hairpin turns. A test carried out on a benchmark dataset also indicates that the use of knowledge on the class specific variations can improve the performance of a PB based structure comparison approach. The preference for the indel sites also seem to be confined to a few backbone conformations involving β-turns and helix C-caps. These are mainly associated with short loops joining the regular secondary structures that mediate a reversal in the chain direction. Rare β-turns of type I’ and II’ are also identified as preferred sites for insertions. PMID:22745680
Class I Microcins: Their Structures, Activities, and Mechanisms of Resistance
NASA Astrophysics Data System (ADS)
Severinov, Konstantin; Semenova, Ekaterina; Kazakov, Teymur
Microcin J25, microcin B17, and microcin C7-C51 are the three known members of class I posttranslationally modified microcins (heavily posttranslationally modified antibacterial peptides produced by Enterobacteriaceae with molecular weights of less than 5 kDa). The three microcins are unrelated to each other; they have structures that are highly atypical for ribosomally synthesized peptides and target essential molecular machines that are validated drug targets. In this chapter, available data on mechanisms of action, structure-activity relationships, and immunity mechanisms for class I microcins and related compounds are discussed.
NASA Astrophysics Data System (ADS)
Liu, J.; Lan, T.; Qin, H.
2017-10-01
Traditional data cleaning identifies dirty data by classifying original data sequences, which is a class-imbalanced problem since the proportion of incorrect data is much less than the proportion of correct ones for most diagnostic systems in Magnetic Confinement Fusion (MCF) devices. When using machine learning algorithms to classify diagnostic data based on class-imbalanced training set, most classifiers are biased towards the major class and show very poor classification rates on the minor class. By transforming the direct classification problem about original data sequences into a classification problem about the physical similarity between data sequences, the class-balanced effect of Time-Domain Global Similarity (TDGS) method on training set structure is investigated in this paper. Meanwhile, the impact of improved training set structure on data cleaning performance of TDGS method is demonstrated with an application example in EAST POlarimetry-INTerferometry (POINT) system.
Silverwood, Richard J.; Nitsch, Dorothea; Pierce, Mary; Kuh, Diana; Mishra, Gita D.
2011-01-01
The authors aimed to describe how longitudinal patterns of physical activity during mid-adulthood (ages 31–53 years) can be characterized using latent class analysis in a population-based birth cohort study, the Medical Research Council’s 1946 National Survey of Health and Development. Three different types of physical activity—walking, cycling, and leisure-time physical activity—were analyzed separately using self-reported data collected from questionnaires between 1977 and 1999; 3,847 study members were included in the analysis for one or more types of activity. Patterns of activity differed by sex, so stratified analyses were conducted. Two walking latent classes were identified representing low (52.8% of males in the cohort, 33.5% of females) and high (47.2%, 66.5%) levels of activity. Similar low (91.4%, 82.1%) and high (8.6%, 17.9%) classes were found for cycling, while 3 classes were identified for leisure-time physical activity: “low activity” (46.2%, 48.2%), “sports and leisure activity” (31.0%, 35.3%), and “gardening and do-it-yourself activities” (22.8%, 16.5%). The classes were reasonably or very well separated, with the exception of walking in females. Latent class analysis was found to be a useful tool for characterizing longitudinal patterns of physical activity, even when the measurement instrument differs slightly across ages, which added value in comparison with observed activity at a single age. PMID:22074812
ERIC Educational Resources Information Center
Bennett, Pamela R.; Lutz, Amy C.; Jayaram, Lakshmi
2012-01-01
We investigate class differences in youth activity participation with interview, survey, and archival data from a diverse sample of parents (n = 51) in two schools. Findings point toward structural rather than cultural explanations. Working- and middle-class parents overlap in parenting logics about participation, though differ in one respect:…
ERIC Educational Resources Information Center
Horvat, Erin McNamara
Our schools are environments of race and class and these school environments structure opportunity based on race and class. This paper explores how students' lives and their access to postsecondary education are framed and structured by the influences of race and class. The college choice decision process of three female Black students from a…
Crystal structure of the YDR533c S. cerevisiae protein, a class II member of the Hsp31 family.
Graille, Marc; Quevillon-Cheruel, Sophie; Leulliot, Nicolas; Zhou, Cong-Zhao; Li de la Sierra Gallay, Ines; Jacquamet, Lilian; Ferrer, Jean-Luc; Liger, Dominique; Poupon, Anne; Janin, Joel; van Tilbeurgh, Herman
2004-05-01
The ORF YDR533c from Saccharomyces cerevisiae codes for a 25.5 kDa protein of unknown biochemical function. Transcriptome analysis of yeast has shown that this gene is activated in response to various stress conditions together with proteins belonging to the heat shock family. In order to clarify its biochemical function, we determined the crystal structure of YDR533c to 1.85 A resolution by the single anomalous diffraction method. The protein possesses an alpha/beta hydrolase fold and a putative Cys-His-Glu catalytic triad common to a large enzyme family containing proteases, amidotransferases, lipases, and esterases. The protein has strong structural resemblance with the E. coli Hsp31 protein and the intracellular protease I from Pyrococcus horikoshii, which are considered class I and class III members of the Hsp31 family, respectively. Detailed structural analysis strongly suggests that the YDR533c protein crystal structure is the first one of a class II member of the Hsp31 family.
ERIC Educational Resources Information Center
Roth, Dana; Rimmerman, Arie
2009-01-01
This exploratory research studied middle-class mother's primary reason for registering their young children, mean age 6.9 years, in adapted motor and sports programs and their perceptions of their children upon entering the program and upon completion. Analyses also examined the possible relationship between mothers' age, education or children's…
ERIC Educational Resources Information Center
Hoover, Jill R.
2018-01-01
Purpose: The purpose of the current study was to determine the effect of neighborhood density and syntactic class on word recognition in children with specific language impairment (SLI) and typical development (TD). Method: Fifteen children with SLI ("M" age = 6;5 [years;months]) and 15 with TD ("M" age = 6;4) completed a…
ERIC Educational Resources Information Center
Strand, Steve
2014-01-01
Perhaps the most prevailing inequalities in educational achievement in England are those associated with socio-economic status (SES), ethnicity and gender. However, little research has sought to compare the relative size of these gaps or to explore interactions between these factors. This paper analyses the educational achievement at age 11, 14…
ERIC Educational Resources Information Center
Onyeaso, Adedamola Olutoyin; Onyeaso, Chukwudi Ochi
2016-01-01
Background: The need for training of schoolchildren on cardiopulmonary resuscitation (CPR) as potential bystander CPR providers is growing globally but Nigeria is still behind and lacks basic necessary data. Purpose: The purpose of this study was to investigate the effects of age, gender and school class on CPR skills of Nigerian secondary school…
ERIC Educational Resources Information Center
Charles, Richard F.
The 106 community colleges in California were surveyed by questionnaire to determine their current level of commitment to the aged in terms of programs and courses available, adult participation, and methods used to conduct programs. Eighty-three questionnaires (78%) were returned. Of the responding colleges, 43% were currently offering classes or…
Effects of a Regular Motor Activity on Somatic and Fitness Variables in Boys Aged 17-18 Years
ERIC Educational Resources Information Center
Piotrowska, Joanna
2011-01-01
Study aim: To assess the somatic and fitness changes in semisedentary boys persuaded to undertake Nordic Walking activities throughout a school year. Material and methods: Two groups of schoolboys aged 17-18 years were studied: regularly attending physical education (PE) classes (Group A; n = 46) and those who avoided PE classes by submitting sick…
Lima, Adriano Fonseca; Soares, Giulliana Panfiglio; Vasconcellos, Pedro Henrique; Ambrosano, Gláucia Maria; Marchi, Giselle Maria; Lovadino, José Roberto; Aguiar, Flávio Henrique
2011-06-01
To evaluate interface degradation leading to marginal microleakeage in Class II restorations that had received an application of surface sealant at the tooth/restoration interface or not. Eighty bovine incisors were used, and the teeth were split obliquely, 10 mm from the amelodentinal proximal junction, and finished with water abrasive papers to obtain a smooth, flat incisal surface. Cavities were made to simulate Class II preparations (8 mm high, 4 mm wide and 1.5 mm deep), and the restorations were performed with a composite resin. Teeth were then randomly allocated into 8 groups according to the surface sealant (none, Fortify, Single Bond 2, or Scothbond MP Plus) and aging process (none or thermocycling and storage for 6 months). Microleakage was then evaluated using a dye penetration method immediately after the restoration or after aging. The samples were triturated and assessed by spectrophotometer. Microleakage was statistically similar in all groups when assessed immediately after the restorative procedure. After aging, teeth sealed with Fortify presented better results than the other groups. Aging causes interface degradation and increased microleakage. Surface sealant can reduce these effects and decrease microleakage in Class II restorations.
A Latent Class Analysis of Family Characteristics Linked to Youth Offending Outcomes.
Chng, Grace S; Chu, Chi Meng; Zeng, Gerald; Li, Dongdong; Ting, Ming Hwa
2016-11-01
There were two aims to this study: firstly, to identify family subtypes of Singaporean youth offenders based on eight family variables. Secondly, the associations of these family subtypes with youth offending outcomes were tested. With a sample of 3,744 youth, a latent class analysis was first conducted based on eight family variables. Multivariate analyses and a Cox regression were subsequently performed to analyze the associations of the family classes with age at first arrest, age at first charge, and recidivism. A three-class solution was found to have the best fit to the data: (1) intact functioning families had little family risk; (2) families with criminality had higher probabilities of family criminality, of drug/alcohol abuse, and of being nonintact; and (3) poorly managed families received the poorest parenting and were more likely to be nonintact. Youth offenders from the latter two classes were arrested and charged at younger ages. Additionally, they reoffended at a quicker rate. Family backgrounds matter for youth offending outcomes. Interventions have to be multifaceted and targeted at the family in order to mitigate the risk of young offenders from developing into pathological adult criminals.
A Latent Class Analysis of Family Characteristics Linked to Youth Offending Outcomes
Chu, Chi Meng; Zeng, Gerald; Li, Dongdong; Ting, Ming Hwa
2016-01-01
Objectives: There were two aims to this study: firstly, to identify family subtypes of Singaporean youth offenders based on eight family variables. Secondly, the associations of these family subtypes with youth offending outcomes were tested. Methods: With a sample of 3,744 youth, a latent class analysis was first conducted based on eight family variables. Multivariate analyses and a Cox regression were subsequently performed to analyze the associations of the family classes with age at first arrest, age at first charge, and recidivism. Results: A three-class solution was found to have the best fit to the data: (1) intact functioning families had little family risk; (2) families with criminality had higher probabilities of family criminality, of drug/alcohol abuse, and of being nonintact; and (3) poorly managed families received the poorest parenting and were more likely to be nonintact. Youth offenders from the latter two classes were arrested and charged at younger ages. Additionally, they reoffended at a quicker rate. Conclusions: Family backgrounds matter for youth offending outcomes. Interventions have to be multifaceted and targeted at the family in order to mitigate the risk of young offenders from developing into pathological adult criminals. PMID:28736458
Occupational accidents in the Finnish local government sector: utilisation of national statistics.
Nenonen, Noora
2011-12-01
Occupational accidents in the Finnish local government sector in 2004 are analysed by gender, age and occupation class in order to identify particular risk groups. The accident data are compared with data concerning the number of employees, using frequency distributions and accident incidence rates. The possibilities of providing occupation class-specific accident incidence rates are also discussed. According to the results, commuting accidents are more common and severe in the local government sector than in general in Finland. In the local public sector occupational accidents more often involved women than men. Compared to other age groups and occupational classes, occupational accidents are more common in the age band of 45-54 and in the occupational class of medical and nursing work. However, compared to the employees' data, men and younger employees had an increased workplace accident risk, while women and older employees had an increased risk of commuting accidents. The highest accident incidence rate was in farming and animal husbandry work. Currently, the calculation of occupation class-specific accident incidence rates is difficult. Improving the consistency of the occupation classifications used in the various data sources would facilitate more reliable calculation of rates.
Rank in Self-Defense Forces and risk factors for atherosclerotic disease.
Sakuta, Hidenari; Suzuki, Takashi
2005-10-01
Socioeconomic status is associated with prevalence of and risk for atherosclerotic disease. We investigated the relationship between rank in the Self-Defense Forces (SDFs) and risk factors for atherosclerotic disease among middle-aged, male, SDFs personnel. Subjects were classified into five groups according to their ranks in the SDFs, i.e., class 1 (lowest, n = 289), class 2 (low, n = 170), class 3 (middle, n = 229), class 4 (high, n = 197), and class 5 (highest, n = 89). Low rank was associated with current cigarette smoking, alcohol abstaining, and poorer vegetable consumption. It was also associated with prevalence of type 2 diabetes, elevated gamma-glutamyltransferase activity, and high white blood cell counts. Prevalence of obesity, hypertension, hypercholesterolemia, hypertriglyceridemia, or hyperuricemia was not associated with rank in this population. Rank may be regarded as one of the markers that reflect individual health states among middle-aged male personnel.
RACE-SPECIFIC TRANSITION PATTERNS AMONG ALCOHOL USE CLASSES IN ADOLESCENT GIRLS
Dauber, Sarah E.; Paulson, James F.; Leiferman, Jenn A.
2010-01-01
We used data from the National Longitudinal Study of Adolescent Health to examine transitions among alcohol use classes in 2225 White and African American adolescent girls, and race differences in predictors of transition into and out of problematic drinking classes. Latent class analysis confirmed four classes for White girls and three for AA girls, defined in a previous study. Latent transition analysis revealed more stable abstainers and decreasing alcohol use among AA girls, and more increasing alcohol use among White girls, though stable abstainers were the largest group among both races. Increasing use was predicted by delinquency, academic misbehavior, substance use, and peer support for White girls, and by older age and delinquency for AA girls. Decreasing use was predicted by older age and depressive symptoms for White girls, and by family relationship quality and substance use for AA girls. Study limitations and implications of findings are discussed. PMID:20708254
ERIC Educational Resources Information Center
Ohio State Univ., Columbus. National Center for Research in Vocational Education.
This self-paced, individualized course, adapted from military curriculum materials for use in vocational and technical education, teaches students the skills needed to become aviation structural mechanics (second class). The course materials consist of five pamphlets covering the structural maintenance and repair of aircraft. The first pamphlet…
Warner, D.M.; Kiley, C.S.; Claramunt, R.M.; Clapp, D.F.
2008-01-01
We used growth and diet data from a fishery-independent survey of Chinook salmon Oncorhynchus tshawytscha, acoustic estimates of prey density and biomass, and statistical catch-at-age modeling to study the influence of the year-class strength of alewife Alosa pseudoharengus on the prey selection and abundance of age-1 Chinook salmon in Lake Michigan during the years 1992-1996 and 2001-2005. Alewives age 2 or younger were a large part of age-1 Chinook salmon diets but were not selectively fed upon by age-1 Chinook salmon in most years. Feeding by age-1 Chinook salmon on alewives age 2 or younger became selective as the biomass of alewives in that young age bracket increased, and age-1 Chinook salmon also fed selectively on young bloaters Coregonus hoyi when bloater density was high. Selection of older alewives decreased at high densities of alewives age 2 or younger and, in some cases, high densities of bloater. The weight and condition of age-1 Chinook salmon were not related to age-1 Chinook salmon abundance or prey abundance, but the abundance of age-1 Chinook salmon in year t was positively related to the density of age-0 alewives in year t - 1. Our results suggest that alewife year-class strength exerts a positive bottom-up influence on age-1 Chinook salmon abundance, prey switching behavior by young Chinook salmon contributing to the stability of the predator-prey relationship between Chinook salmon and alewives. ?? Copyright by the American Fisheries Society 2008.
Fan, Ming; Zheng, Bin; Li, Lihua
2015-10-01
Knowledge of the structural class of a given protein is important for understanding its folding patterns. Although a lot of efforts have been made, it still remains a challenging problem for prediction of protein structural class solely from protein sequences. The feature extraction and classification of proteins are the main problems in prediction. In this research, we extended our earlier work regarding these two aspects. In protein feature extraction, we proposed a scheme by calculating the word frequency and word position from sequences of amino acid, reduced amino acid, and secondary structure. For an accurate classification of the structural class of protein, we developed a novel Multi-Agent Ada-Boost (MA-Ada) method by integrating the features of Multi-Agent system into Ada-Boost algorithm. Extensive experiments were taken to test and compare the proposed method using four benchmark datasets in low homology. The results showed classification accuracies of 88.5%, 96.0%, 88.4%, and 85.5%, respectively, which are much better compared with the existing methods. The source code and dataset are available on request.
Adjusting for case mix and social class in examining variation in home visits between practices.
Sullivan, Caoimhe O; Omar, Rumana Z; Forrest, Christopher B; Majeed, Azeem
2004-08-01
The purpose of this study was to investigate whether adjusting for clinical case mix and social class explains more of the variation in home visits between general practices than adjusting for age and sex alone. The setting was 60 general practices in England and Wales taking part in the 1 year Fourth National Morbidity Survey. The participants comprised 349 505 patients who were registered with one of the participating general practices for at least 180 days, and who had at least one consultation during the period. The outcome measure is whether or not a patient received a home visit in that year. A clinical case mix category (morbidity class) based on 1 year's diagnostic information was assigned to each patient using the Johns Hopkins Adjusted Clinical Groups (ACG) Case Mix System. The social class measure was derived from occupation and employment status and is similar to that of the 1991 UK census. Variations in home visits between practices were examined using multilevel logistic regression models. The variability between practices before and after adjusting for clinical case mix and social class was estimated using the intracluster correlation coefficient (ICC). The overall percentage of patients receiving a home visit over the 1 year study period was 17%, and this varied from 7 to 31% across the 60 practices. The percentage of the total variation in home visits attributable to differences between practices was 2.5% [95% confidence interval (CI) 1.4-3.2%] after adjusting for age and sex. This reduced to 1.6% (95% CI 1.1-2.4%) after taking into account morbidity class. The results were similar when social class was included instead of morbidity class. Morbidity and social class together reduced variation in home visits between practices to 1.5% (95% CI 1.1-2.2%). Age, sex, social class and clinical case mix are strong determinants of home visits in the UK. Adjusting for morbidity and social class results in a small improvement in explaining the variability in home visits between practices compared with adjusting for age and sex alone. There is far more variation between patients within practices; however, it is not straightforward to examine the factors influencing this variation. In addition to morbidity and social class, there could also be other unmeasured factors such as varying patient demand for home visits, disability or differences in GP home visiting practice style that could influence the large within-practice variability observed in this study.
Kong, Kyoung Ae; Khang, Young-Ho; Cho, Hong-Jun; Jang, Sung-Mi; Jung-Choi, Kyunghee
2017-04-20
The aim of this study was to examine the pattern of social inequality in self-rated health among the employed using the Wright's social class location indicator, and to assess the roles of material, behavioral, psychosocial, and workplace environmental factors as mediating factors in explaining the social class inequality in self-rated health in South Korea. This study used data from the 4th Korea National Health and Nutrition Examination Survey from 2007 to 2009. Study subjects included the employed population of 4392 men and 3309 women aged 19-64 years. Subjects were classified into twelve social class positions based on the Wright's social class map. The health outcome was self-rated health. Material, psychosocial, behavioral, and workplace environmental factors were considered as potential mediators in explaining social class health inequality. We calculated prevalence ratios of poor self-rated health according to social class, adjusted for age and mediating factors using Poisson regression models. Nonskilled workers and petty bourgeoisie reported worse self-rated health than other social classes among men. The age-adjusted prevalence of petty bourgeoisie and nonskilled workers were about four-fold greater than that of managers. Expert supervisors in the contradictory class location had a greater prevalence of poor self-rated health than experts in men. In women, the prevalence of poor self-rated health was greater in most social classes than their male counterparts, while the differences among social classes within women were not statistically significant. Workplace environmental factors explained the social class inequality by from 24 to 31% in nonskilled and skilled workers and nonskilled supervisors, respectively, and material factors showed an explanatory ability of about 8% for both nonskilled workers and petty bourgeoisie in men. We showed the inequality in self-rated health according to the Wright's social class in an industrialized Asian country. Policy efforts to improve workplace environments in nonskilled and skilled workers and nonskilled supervisors would have a moderate effect on reducing the magnitude of social class inequality in self-rated health. Furthermore, the means to improve power relations in the workplace should be devised to further reduce the social class inequalities in health.
Stress and Multiple Substance Use Behaviors Among Hispanic Adolescents.
Cardoso, Jodi Berger; Goldbach, Jeremy T; Cervantes, Richard C; Swank, Paul
2016-02-01
Hispanic adolescents reported a higher annual prevalence of use of nearly all major drugs compared to non-Hispanic White and African American adolescents. Cultural or minority stressors, such as those related to the acculturation process, discrimination, immigration, poverty, and community violence, have been implicated in these outcomes. Unfortunately, few studies have examined how these stressors may have a differential or additive effect when considered simultaneously. The current study examined the relation between stress and multiple substance use behaviors in a sample of Hispanic adolescents (n = 1036), age 11-19 years old. Latent class analysis identified subgroups of Hispanic adolescents based on combinations of substance use behaviors. General linear models were used to examine mean differences by class among the eight domains of stress. Fit statistics revealed a six-class structure: no substance use risk, predominately alcohol use, low polysubstance use, high polysubstance use, illicit drug use, and predominately marijuana use. Differences in stress across the six classes were identified for four of the eight domains: family economic, acculturation gap, community and gang, and family and drug stress. The effect sizes revealed the largest mean differences in stress between the no substance use group and the two polysubstance use groups and between the no risk group and alcohol use group. The findings from this study support the use of interventions that target stress to affect multiple substance use behaviors in Hispanic adolescents.
Binding pose and affinity prediction in the 2016 D3R Grand Challenge 2 using the Wilma-SIE method
NASA Astrophysics Data System (ADS)
Hogues, Hervé; Sulea, Traian; Gaudreault, Francis; Corbeil, Christopher R.; Purisima, Enrico O.
2018-01-01
The Farnesoid X receptor (FXR) exhibits significant backbone movement in response to the binding of various ligands and can be a challenge for pose prediction algorithms. As part of the D3R Grand Challenge 2, we tested Wilma-SIE, a rigid-protein docking method, on a set of 36 FXR ligands for which the crystal structures had originally been blinded. These ligands covered several classes of compounds. To overcome the rigid protein limitations of the method, we used an ensemble of publicly available structures for FXR from the PDB. The use of the ensemble allowed Wilma-SIE to predict poses with average and median RMSDs of 2.3 and 1.4 Å, respectively. It was quite clear, however, that had we used a single structure for the receptor the success rate would have been much lower. The most successful predictions were obtained on chemical classes for which one or more crystal structures of the receptor bound to a molecule of the same class was available. In the absence of a crystal structure for the class, observing a consensus binding mode for the ligands of the class using one or more receptor structures of other classes seemed to be indicative of a reasonable pose prediction. Affinity prediction proved to be more challenging with generally poor correlation with experimental IC50s (Kendall tau 0.3). Even when the 36 crystal structures were used the accuracy of the predicted affinities was not appreciably improved. A possible cause of difficulty is the internal energy strain arising from conformational differences in the receptor across complexes, which may need to be properly estimated and incorporated into the SIE scoring function.
Retinal Laminar Architecture in Human Retinitis Pigmentosa Caused by Rhodopsin Gene Mutations
Aleman, Tomas S.; Cideciyan, Artur V.; Sumaroka, Alexander; Windsor, Elizabeth A. M.; Herrera, Waldo; White, D. Alan; Kaushal, Shalesh; Naidu, Anjani; Roman, Alejandro J.; Schwartz, Sharon B.; Stone, Edwin M.; Jacobson, Samuel G.
2008-01-01
Purpose. To determine the underlying retinal micropathology in subclasses of autosomal dominant retinitis pigmentosa (ADRP) caused by rhodopsin (RHO) mutations. Methods. Patients with RHO-ADRP (n = 17, ages 6–73 years), representing class A (R135W and P347L) and class B (P23H, T58R, and G106R) functional phenotypes, were studied with optical coherence tomography (OCT), and colocalized visual thresholds were determined by dark- and light-adapted chromatic perimetry. Autofluorescence imaging was performed with near-infrared light. Retinal histology in hT17M-rhodopsin mice was compared with the human results. Results. Class A patients had only cone-mediated vision. The outer nuclear layer (ONL) thinned with eccentricity and was not detectable within 3 to 4 mm of the fovea. Scotomatous extracentral retina showed loss of ONL, thickening of the inner retina, and demelanization of RPE. Class B patients had superior–inferior asymmetry in function and structure. The superior retina could have normal rod and cone vision, normal lamination (including ONL) and autofluorescence of the RPE melanin; laminopathy was found in the scotomas. With Fourier-domain-OCT, there was apparent inner nuclear layer (INL) thickening in regions with ONL thinning. Retinal regions without ONL had a thick hyporeflective layer that was continuous with the INL from neighboring regions with normal lamination. Transgenic mice had many of the laminar abnormalities found in patients. Conclusions. Retinal laminar abnormalities were present in both classes of RHO-ADRP and were related to the severity of colocalized vision loss. The results in human class B and the transgenic mice support the following disease sequence: ONL diminution with INL thickening; amalgamation of residual ONL with the thickened INL; and progressive retinal remodeling with eventual thinning. PMID:18385078
Pagliaccio, David; Pine, Daniel S; Barch, Deanna M; Luby, Joan L; Leibenluft, Ellen
2018-05-01
Cross-sectional, longitudinal, and genetic associations exist between irritability and depression. Prior studies have examined developmental trajectories of irritability, clinical outcomes, and associations with child and familial depression. However, studies have not integrated neurobiological measures. The present study examined developmental trajectories of irritability, clinical outcomes, and cortical structure among preschoolers oversampled for depressive symptoms. Beginning at 3 to 5 years old, a sample of 271 children enriched for early depressive symptoms were assessed longitudinally by clinical interview. Latent class mixture models identified trajectories of irritability severity. Risk factors, clinical outcomes, and cortical thickness were compared across trajectory classes. Cortical thickness measures were extracted from 3 waves of magnetic resonance imaging at 7 to 12 years of age. Three trajectory classes were identified among these youth: 53.50% of children exhibited elevated irritability during preschool that decreased longitudinally, 30.26% exhibited consistently low irritability, and 16.24% exhibited consistently elevated irritability. Compared with other classes, the elevated irritability class exhibited higher rates of maternal depression, early life adversity, later psychiatric diagnoses, and functional impairment. Further, elevated baseline irritability predicted later depression beyond adversity and personal and maternal depression history. The elevated irritability class exhibited a thicker cortex in the left superior frontal and temporal gyri and the right inferior parietal lobule. Irritability manifested with specific developmental trajectories in this sample enriched for early depression. Persistently elevated irritability predicted poor psychiatric outcomes, higher risk for later depression, and decreased overall function later in development. Greater frontal, temporal, and parietal cortical thickness also was found, providing neural correlates of this risk trajectory. Copyright © 2018 American Academy of Child and Adolescent Psychiatry. All rights reserved.
Fluvial-deltaic sedimentation and stratigraphy of the ferron sandstone
Anderson, P.B.; Chidsey, T.C.; Ryer, T.A.
1997-01-01
East-central Utah has world-class outcrops of dominantly fluvial-deltaic Turonian to Coniacian aged strata deposited in the Cretaceous foreland basin. The Ferron Sandstone Member of the Mancos Shale records the influences of both tidal and wave energy on fluvial-dominated deltas on the western margin of the Cretaceous western interior seaway. Revisions of the stratigraphy are proposed for the Ferron Sandstone. Facies representing a variety of environments of deposition are well exposed, including delta-front, strandline, marginal marine, and coastal-plain. Some of these facies are described in detail for use in petroleum reservoir characterization and include permeability structure.
Kurczynska, Monika; Kotulska, Malgorzata
2018-01-01
Mirror protein structures are often considered as artifacts in modeling protein structures. However, they may soon become a new branch of biochemistry. Moreover, methods of protein structure reconstruction, based on their residue-residue contact maps, need methodology to differentiate between models of native and mirror orientation, especially regarding the reconstructed backbones. We analyzed 130 500 structural protein models obtained from contact maps of 1 305 SCOP domains belonging to all 7 structural classes. On average, the same numbers of native and mirror models were obtained among 100 models generated for each domain. Since their structural features are often not sufficient for differentiating between the two types of model orientations, we proposed to apply various energy terms (ETs) from PyRosetta to separate native and mirror models. To automate the procedure for differentiating these models, the k-means clustering algorithm was applied. Using total energy did not allow to obtain appropriate clusters-the accuracy of the clustering for class A (all helices) was no more than 0.52. Therefore, we tested a series of different k-means clusterings based on various combinations of ETs. Finally, applying two most differentiating ETs for each class allowed to obtain satisfying results. To unify the method for differentiating between native and mirror models, independent of their structural class, the two best ETs for each class were considered. Finally, the k-means clustering algorithm used three common ETs: probability of amino acid assuming certain values of dihedral angles Φ and Ψ, Ramachandran preferences and Coulomb interactions. The accuracies of clustering with these ETs were in the range between 0.68 and 0.76, with sensitivity and selectivity in the range between 0.68 and 0.87, depending on the structural class. The method can be applied to all fully-automated tools for protein structure reconstruction based on contact maps, especially those analyzing big sets of models.
Kurczynska, Monika
2018-01-01
Mirror protein structures are often considered as artifacts in modeling protein structures. However, they may soon become a new branch of biochemistry. Moreover, methods of protein structure reconstruction, based on their residue-residue contact maps, need methodology to differentiate between models of native and mirror orientation, especially regarding the reconstructed backbones. We analyzed 130 500 structural protein models obtained from contact maps of 1 305 SCOP domains belonging to all 7 structural classes. On average, the same numbers of native and mirror models were obtained among 100 models generated for each domain. Since their structural features are often not sufficient for differentiating between the two types of model orientations, we proposed to apply various energy terms (ETs) from PyRosetta to separate native and mirror models. To automate the procedure for differentiating these models, the k-means clustering algorithm was applied. Using total energy did not allow to obtain appropriate clusters–the accuracy of the clustering for class A (all helices) was no more than 0.52. Therefore, we tested a series of different k-means clusterings based on various combinations of ETs. Finally, applying two most differentiating ETs for each class allowed to obtain satisfying results. To unify the method for differentiating between native and mirror models, independent of their structural class, the two best ETs for each class were considered. Finally, the k-means clustering algorithm used three common ETs: probability of amino acid assuming certain values of dihedral angles Φ and Ψ, Ramachandran preferences and Coulomb interactions. The accuracies of clustering with these ETs were in the range between 0.68 and 0.76, with sensitivity and selectivity in the range between 0.68 and 0.87, depending on the structural class. The method can be applied to all fully-automated tools for protein structure reconstruction based on contact maps, especially those analyzing big sets of models. PMID:29787567
The macular photostress test in diabetes, glaucoma, and cataract
NASA Astrophysics Data System (ADS)
Baptista, António M. G.; Sousa, Raul A. R. C.; Rocha, Filomena A. S. Q.; Fernandes, Paula Sepúlveda; Macedo, António F.
2013-11-01
Purpose. The photostress recovery time test (PSRT) has been widely reported as a helpful screening clinical tool. However, the poor standardization of its measurement technique remains to be a limitation among clinicians. The purpose of this study is to apply a recommended clinical technique to measure the PSRT in some of the most commons eye diseases to ascertain whether these diseases affect the PSRT values. Methods. One hundred and one controls and 105 patients, with diagnosed diabetes (without visible signs of diabetic retinopathy), primary open angle glaucoma (POAG) or cataracts underwent photostress testing. The test was performed with a direct ophthalmoscope for illuminating the macula for 30 seconds. Participants belonged to three age classes: A, B and C; and were divided into four groups: control, diabetic, POAG and cataract. The age range for A, B and C classes were respectively 43-54, 55-64 and 65-74 years. The groups were also further compared within each age class. In addition, the influence of age on PSRT was evaluated using the control group. Results. Results demonstrate that PSRT changes with age (p<0.02). In class A, diabetic group had a faster PSRT than control group, (mean +/- standard deviation) 20.22+/-7.51 and 26.14+/-8.34 seconds. The difference between these groups was statistical significant (t-test, p=0.012). Cataract and POAG groups did not affect the PSRT significantly. Conclusions. The technique used for the Photostress showed that diabetics, younger than 54 years, may have faster PSRT and that, aging delays PSRT.
Arriaza, Mari Carmen; Domínguez-Rodrigo, Manuel; Martínez-Maza, Cayetana; Mabulla, Audax; Baquedano, Enrique
2015-01-01
Age and sex selection of prey is an aspect of predator ecology which has been extensively studied in both temperate and African ecosystems. This dimension, along with fecundity, survival rates of prey and mortality factors other than predation are important in laying down the population dynamics of prey and have important implications in the management of species. A carnivore den located in the short-grassland ecological unit of the Serengeti was studied. Sex- and age- class (using five age categories) of the wildebeest remains recovered were analyzed through horn morphology, biometrics of the bones and tooth wear patterns. We compared our results with previous studies from lion and hyaena kills through multivariate analyses. Seasonality of the accumulation was analyzed through tooth histology. PCA and CVA results show that age class selection by predators depends on season, habitat-type, and growth rate of the wildebeest population. Female-biased predation was found to contradict classical hypotheses based on territorial male behaviour. The lion and spotted hyaena showed strong selection on age classes, contrary to previous studies. Migratory wildebeest sex ratio is regulated through differential predation by seasons and female deaths in the wet season are a trade-off for population stability. These data are crucial for an effective management of the species and the new method created may be useful for different carnivore species and their prey. PMID:26017363
Pigois, J.-P.; Groves, D.I.; Fletcher, I.R.; McNaughton, N.J.; Snee, L.W.
2003-01-01
Two major epigenetic gold-forming events are recorded in the world-class gold province of southwest Ghana. A pre-Tarkwaian event was the source of the world-class Tarkwa palaeoplacers whereas post-Birimian and Tarkwaian deformation, which was related to the Eburnean orogeny, gave rise to the world-class (e.g. Prestea) to giant (e.g. Obuasi) orogenic gold deposits which have made the region famous for more than 2,500 years. A maximum age of 2133 ?? 4 Ma for Tarkwaian sedimentation is provided by 71 of 111 concordant SHRIMP II U Pb dates from detrital zircons in Tarkwaian clastic rocks from Damang and Bippo Bin, northeast of Tarkwa. The overall data distribution broadly overlaps the relatively poorly constrained ages of Birimian volcanism and associated Dixcove-type granitoid emplacement, indicating syntectonic development of the Tarkwaian sedimentary basin. These zircon ages argue against derivation of the palaeoplacer gold from an orogenic gold source related to the compressional phase of an orogeny significantly older than the Eburnean orogeny. Instead, they suggest that the gold source was either orogenic gold lodes related to an earlier compressional phase of a diachronous Eburnean orogeny or ca. 2200-2100 Ma intrusion-related gold lode. The CO2-rich fluid inclusions in associated vein-quartz pebbles are permissive of either source. At the Damang deposit, an epigenetic, orogenic lode-gold system clearly overprinted, and sulphidised low-grade palaeoplacer hematite magnetite gold occurrences in the Banket Series conglomerate within the Tarkwaian sedimentary sequence. Gold mineralisation is demonstrably post-peak metamorphism, as gold-related alteration assemblages overprint metamorphic assemblages in host rocks. In alteration zones surrounding the dominant, subhorizontal auriferous quartz veins, there are rare occurrences of hydrothermal xenotime which give a SHRIMP U Pb age of 2063 ?? 9 Ma for gold mineralisation. The similar structural timing of epigenetic gold mineralisation in Tarkwaian host rocks at Damang to that in mainly Birimian host rocks elsewhere in southwest Ghana, particularly at Obuasi, suggests that 2063 ?? 9 Ma is the best available age estimate for widespread orogenic gold mineralisation in the region. Argon-argon ages of 2029 ?? 4 and 2034 ?? 4 Ma for hydrothermal biotite from auriferous quartz veins appear to represent uplift and cooling of the region below about 300??C, as estimates of the temperature of gold mineralisation are higher, at around 400??C. If peak metamorphism, with temperatures of about 550??C, is assumed to have occurred at about 2100 Ma, the biotite ages, in combination with the xenotime age, suggest a broadly constant uplift rate for the region of about 1 km per 10 million years from about 2100 to 2025 Ma.
The effect of drug use on the age at onset of psychotic disorders in an Australian cohort.
Stefanis, Nikos C; Dragovic, Milan; Power, Brian D; Jablensky, Assen; Castle, David; Morgan, Vera A
2014-07-01
We aimed to examine the association between illicit substance use and age at onset in psychotic disorders in an Australian cohort. Retrospectively acquired information on substance use during the year prior to illness onset was collected from 1642 participants enrolled in the Australian National 2010 Survey of High Impact Psychosis study (SHIP), with an ICD-10 diagnosis of schizophrenia spectrum or affective psychosis. Latent class analysis was performed according to illicit substance use, using age as an active covariate; identified classes were subsequently validated. Cox regression was used to examine the independent contribution of the identified substance use classes and several confounding variables to the prediction of age at onset of psychosis. Three classes according to substance use were identified: non-users (n=803), cannabis predominant users (n=582), and polysubstance users (n=257). For participants with schizophrenia spectrum disorders, cannabis predominant users had a higher hazard of earlier age at onset than for non-users (adjusted HR=1.38, 95% CI=1.2-1.6); polysubstance users had an even higher hazard (adjusted HR=1.95, 95% CI=1.5-2.4). In contrast, for participants with affective psychosis, cannabis predominant users (adjusted HR=1.10, 95% CI=0.8-1.4) and polysubstance users (adjusted HR=0.87, 95% CI=0.6-1.3) did not have a higher hazard of earlier age at onset compared with non-users. Illicit substance use in the 12 months prior to psychosis onset has a differential effect on age at onset in schizophrenia spectrum and affective psychotic disorders. Our findings are compatible with the notion that illicit drugs bring forward age at onset in schizophrenia spectrum disorders but not affective psychotic disorders. Copyright © 2014. Published by Elsevier B.V.
Proust, Hélène; Honkanen, Suvi; Jones, Victor A S; Morieri, Giulia; Prescott, Helen; Kelly, Steve; Ishizaki, Kimitsune; Kohchi, Takayuki; Dolan, Liam
2016-01-11
The colonization of the land by plants, sometime before 470 million years ago, was accompanied by the evolution tissue systems [1-3]. Specialized structures with diverse functions-from nutrient acquisition to reproduction-derived from single cells in the outermost layer (epidermis) were important sources of morphological innovation at this time [2, 4, 5]. In extant plants, these structures may be unicellular extensions, such as root hairs or rhizoids [6-9], or multicellular structures, such as asexual propagules or secretory hairs (papillae) [10-12]. Here, we show that a ROOTHAIR DEFECTIVE SIX-LIKE (RSL) class I basic helix-loop-helix transcription factor positively regulates the development of the unicellular and multicellular structures that develop from individual cells that expand out of the epidermal plane of the liverwort Marchantia polymorpha; mutants that lack MpRSL1 function do not develop rhizoids, slime papillae, mucilage papillae, or gemmae. Furthermore, we discovered that RSL class I genes are also required for the development of multicellular axillary hairs on the gametophyte of the moss Physcomitrella patens. Because class I RSL proteins also control the development of rhizoids in mosses and root hairs in angiosperms [13, 14], these data demonstrate that the function of RSL class I genes was to control the development of structures derived from single epidermal cells in the common ancestor of the land plants. Class I RSL genes therefore controlled the generation of adaptive morphological diversity as plants colonized the land from the water. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Proust, Hélène; Honkanen, Suvi; Jones, Victor A.S.; Morieri, Giulia; Prescott, Helen; Kelly, Steve; Ishizaki, Kimitsune; Kohchi, Takayuki; Dolan, Liam
2016-01-01
Summary The colonization of the land by plants, sometime before 470 million years ago, was accompanied by the evolution tissue systems [1, 2, 3]. Specialized structures with diverse functions—from nutrient acquisition to reproduction—derived from single cells in the outermost layer (epidermis) were important sources of morphological innovation at this time [2, 4, 5]. In extant plants, these structures may be unicellular extensions, such as root hairs or rhizoids [6, 7, 8, 9], or multicellular structures, such as asexual propagules or secretory hairs (papillae) [10, 11, 12]. Here, we show that a ROOTHAIR DEFECTIVE SIX-LIKE (RSL) class I basic helix-loop-helix transcription factor positively regulates the development of the unicellular and multicellular structures that develop from individual cells that expand out of the epidermal plane of the liverwort Marchantia polymorpha; mutants that lack MpRSL1 function do not develop rhizoids, slime papillae, mucilage papillae, or gemmae. Furthermore, we discovered that RSL class I genes are also required for the development of multicellular axillary hairs on the gametophyte of the moss Physcomitrella patens. Because class I RSL proteins also control the development of rhizoids in mosses and root hairs in angiosperms [13, 14], these data demonstrate that the function of RSL class I genes was to control the development of structures derived from single epidermal cells in the common ancestor of the land plants. Class I RSL genes therefore controlled the generation of adaptive morphological diversity as plants colonized the land from the water. PMID:26725198
Cronin, Matthew A.; Amstrup, Steven C.; Durner, George M.; Noel, Lynn E.; McDonald, Trent L.; Ballard, Warren B.
1998-01-01
There is concern that caribou (Rangifer tarandus) may avoid roads and facilities (i.e., infrastructure) in the Prudhoe Bay oil field (PBOF) in northern Alaska, and that this avoidance can have negative effects on the animals. We quantified the relationship between caribou distribution and PBOF infrastructure during the post-calving period (mid-June to mid-August) with aerial surveys from 1990 to 1995. We conducted four to eight surveys per year with complete coverage of the PBOF. We identified active oil field infrastructure and used a geographic information system (GIS) to construct ten 1 km wide concentric intervals surrounding the infrastructure. We tested whether caribou distribution is related to distance from infrastructure with a chi-squared habitat utilization-availability analysis and log-linear regression. We considered bulls, calves, and total caribou of all sex/age classes separately. The habitat utilization-availability analysis indicated there was no consistent trend of attraction to or avoidance of infrastructure. Caribou frequently were more abundant than expected in the intervals close to infrastructure, and this trend was more pronounced for bulls and for total caribou of all sex/age classes than for calves. Log-linear regression (with Poisson error structure) of numbers of caribou and distance from infrastructure were also done, with and without combining data into the 1 km distance intervals. The analysis without intervals revealed no relationship between caribou distribution and distance from oil field infrastructure, or between caribou distribution and Julian date, year, or distance from the Beaufort Sea coast. The log-linear regression with caribou combined into distance intervals showed the density of bulls and total caribou of all sex/age classes declined with distance from infrastructure. Our results indicate that during the post-calving period: 1) caribou distribution is largely unrelated to distance from infrastructure; 2) caribou regularly use habitats in the PBOF; 3) caribou often occur close to infrastructure; and 4) caribou do not appear to avoid oil field infrastructure.
Children's Understanding of Social Class Differences.
ERIC Educational Resources Information Center
Naimark, Hedwin
Investigated were school children's recognition of social class distinctions, cues they used, and the relationship of their ideas about social class to other beliefs and attitudes about the social world. An ethnically mixed group of 201 male and female subjects participated in the study. Five age groups were represented: second, fifth, and sixth…
Salazar-Lazo, Rodrigo; Arriola-Guillén, Luis E; Flores-Mir, Carlos
2014-01-01
The aim of the present work was to determine the duration of the adolescent peak growth spurt using cervical vertebral maturation analysis in class I and II malocclusion subjects. The study was conducted on a sample which consisted of 154 lateral cephalograms of children and adolescents aged 9-15 years (84 females and 70 males). The evaluation of skeletal maturation stage was performed using a visual morphological analysis of CS3 and CS4 cervical vertebrae. The sagittal skeletal relation was evaluated according to Steiner analysis. Descriptive statistics were used to summarize chronological age in each malocclusion group and for each CS3 and CS4 skeletal maturation stage. Due to a lack of normal distribution, comparisons of CS3 and CS4 age intervals on class I and II subjects were compared using the Mann-Whitney U test for independent samples. The results show that the mean duration of the adolescent peak growth spurt was 10 months between CS3 and CS4 stages in class I malocclusion subjects, whereas in class II malocclusion patients the duration was 6 months. This difference of 4 months was statistically significant (p<0.001). Finally, a clinically significant difference of 4 months in the duration of the adolescent peak growth spurt for class I and II malocclusion subjects was identified.
Class and Health Inequality in Later Life: Patterns, Mechanisms and Implications for Policy
Nazroo, James
2017-01-01
The growth of the post-retirement population, which has occurred as a result of rapid growth in life expectancy coupled with the ageing of the baby boomer cohort, has led to significant concern. This concern, however, typically neglects the heterogeneity of later life experiences and how these are patterned by inequalities that reflect how process of social stratification continue to operate into later life. This paper draws on a programme of work, based on analysis of the English Longitudinal Study of Ageing, to empirically examine questions of inequality in later life. It begins by illustrating the patterning of health inequality. It then investigates the importance of later life contexts and events in shaping inequality through and after the retirement process. In doing so it examines the extent to which later life continues to reflect stable social structures that shape inequalities and, consequently, health and wellbeing in later life. The paper then illustrates how the effects of socioeconomic position on health in later life can be theorised as a product of class processes, borrowing in part from Bourdieu. Other dimensions of inequality, such as gender, ethnicity, area and sexuality, are not discussed here. The paper concludes with a discussion of the need for a close focus on inequalities in later life in research, policy and practice. PMID:29292775
David R. Woodruff; Frederick C. Meinzer
2011-01-01
We analyzed concentrations of starch, sucrose, glucose and fructose in upper branch wood, foliage and trunk sapwood of Douglas-fir trees in height classes ranging from ~2 to ~57 m. Mean concentrations of non-structural carbohydrates (NSC) for all tissues were highest in the tallest height class and lowest in the lowest height class, and height-related trends in NSC...
Jefferis, Barbara J M H; Power, Chris; Hertzman, Clyde
2002-01-01
Objectives To examine the combined effect of social class and weight at birth on cognitive trajectories during school age and the associations between birth weight and educational outcomes through to 33 years. Design Longitudinal, population based, birth cohort study. Participants 10 845 males and females born during 3-9 March 1958 with information on birth weight, social class, and cognitive tests. Main outcome measures Reading, maths, draw a man, copying designs, verbal and non-verbal ability tests at ages 7, 11, and 16, highest qualifications achieved by 33, and trajectories of maths standardised scores at 7-16 years. Results The outcome of all childhood cognitive tests and educational achievements improved significantly with increasing birth weight. Analysis of maths scores at 7 and of highest qualifications achieved by 33 showed that the relations were robust to adjustment for potential confounding factors. For each kilogram increase in birth weight, maths z score increased by 0.17 (adjusted estimate 0.15, 95% confidence interval 0.10 to 0.21) for males and 0.21 (0.20, 0.14 to 0.25) for females. Trajectories of maths z scores between 7 and 16 years diverged for different social class groups: participants from classes I and II increased their relative position on the score with increasing age, whereas classes IV and V showed a relative decline with increasing age. Birth weight explained much less of the variation in cognition than did social class (range 0.5-1.5% v 2.9-12.5%). Conclusions The postnatal environment has an overwhelming influence on cognitive function through to early adulthood, but these strong effects do not explain the weaker but independent association with birth weight. What is already known on this topicWeight at birth is associated with later cognitive developmentThis is maintained across the range of normal birth weightsWhat this study addsSocial class at birth and birth weight have independent effects on maths scores in childhood, but social class at birth explains more of the variation in the scoresThe relation between maths scores and birth weight persists across birth weights after adjustment for gestational age, parental education, and other potential confounding factorsTrajectories of maths attainment diverge, with more affluent social groups increasing their relative advantage whereas the effect of birth weight remains constant over time PMID:12169505
Developmental trajectories of irritability and bidirectional associations with maternal depression.
Wiggins, Jillian Lee; Mitchell, Colter; Stringaris, Argyris; Leibenluft, Ellen
2014-11-01
Irritability is a dimensional trait in typical development and a common presenting symptom in many psychiatric disorders, including depression. However, little is known about the developmental trajectory of irritability or how child irritability interacts with maternal depression. The present study identifies classes of irritability trajectories from toddlerhood to middle childhood; characterizes maternal depression and other family, social environment, and child variables within each irritability trajectory class; and, as a more exploratory analysis, examines bidirectional associations between maternal depression and child irritability. A total of 4,898 families from the Fragile Families and Child Wellbeing Study reported on irritability symptoms at ages 3, 5, and 9 years, assessed with items from the Child Behavior Checklist. Parental major depressive episode was assessed using the Composite International Diagnostic Interview-Short Form at child ages 1, 3, 5, and 9 years. A latent class growth analysis identified 5 irritability classes: low decreasing; moderate decreasing; high steady; initially very high, then decreasing; and high increasing. Children with more severe irritability trajectories are more likely to have mothers with recurrent depression, and, with the exception of the most severe (high increasing irritability) class, were more likely to have mothers who were exposed to violence. Moreover, paternal depression and alcohol abuse, as well as maternal drug and alcohol abuse, were also risk factors for membership in the more severe irritability classes. A latent auto-regressive cross-lag model showed that child irritability at ages 3 and 5 years is associated with increased mother depression at ages 5 and 9, respectively. Conversely, mother depression at child ages 1 and 3 years is associated with increased child irritability at 3 and 5. Irritability development across toddlerhood and middle childhood has 5 main trajectory types, which differ on maternal depression recurrence and exposure to violence. Maternal depression and child irritability influence each other bidirectionally, particularly early in development. Understanding irritability development and its bidirectional relationship with maternal depression and association with violence exposure may help identify intervention targets. Published by Elsevier Inc.
Lintsi, Mart; Kaarma, Helje; Aunapuu, Marina; Arend, Andres
2007-03-01
A study of 739 conscripts aged 17 years from the town of Tartu and from the Tartu county was performed. Height, weight, 33 anthropometric measurements and 12 skinfolds were measured. The data were classified into five height-weight mean and SD-classes applying the Estonian reference values for this age and sex (Grünberg et al. 1998). There were 3 classes with conformity between height and weight class: 1--small (small height and small weight), 2--medium (medium height and medium weight), 3--large (large height and large weight), 4--weight class dominating (pyknomorphic) and 5--height class dominating (leptomorphic). It was found, that in classes 1, 2 and 3 the height and weight increase was in accordance with the increase in all heights, breadths and depths, circumferences, skinfolds, body fat, muscle and bone mass. In class 4 circumferences, skinfolds, body fat and muscle mass were bigger. In class 5 all heights and the relative bone mass were bigger. The present investigation confirms the assumption that the five height-weight mean and SD five-class system applying the Estonian reference values for classifying the anthropometric variables is suitable for seventeen-year-old conscripts. As well the border values of 5%, 50% and 95% for every anthropometrical variable in the five-classes were calculated, which may be helpful for practical classifying.
Yilmaz, Zeynep; Javaras, Kristin N; Baker, Jessica H; Thornton, Laura M; Lichtenstein, Paul; Bulik, Cynthia M; Larsson, Henrik
2017-08-01
Disordered eating is more prevalent among adolescents with attention deficit/hyperactivity disorder. Both inattention and hyperactivity/impulsivity symptoms show strong associations with disordered eating, but few investigations of these associations have been longitudinal. Thus, we examined the effect of childhood to adolescent inattention and hyperactivity/impulsivity symptom trajectories on late adolescent disordered eating. We used growth mixture modeling to identify distinct inattention and hyperactivity/impulsivity symptom trajectories (called "classes") across three time points (ages 8-9, 13-14, and 16-17 years) in the Swedish Twin study of CHild and Adolescent Development. The resulting classes were used to predict Eating Disorder Inventory-2 Bulimia, Drive for Thinness, and Body Dissatisfaction subscales at age 16-17 years, with adjustment for sex and body mass index at age 16-17 years. The combined inattention and hyperactivity/impulsivity symptom trajectory classes included: a "low symptom" class characterized by low inattention and hyperactivity/impulsivity throughout childhood/adolescence; a "predominantly inattention" class characterized by elevated inattention, but not hyperactivity/impulsivity, throughout childhood/adolescence; a "predominantly hyp/imp" class characterized by elevated hyperactivity/impulsivity, but not inattention, throughout childhood/adolescence; and a "both inattention and hyp/imp" class characterized by elevated inattention and hyperactivity/impulsivity throughout childhood/adolescence. After adjusting for sex and body mass index or sex and anxiety/depression symptoms, the "both inattention and hyp/imp" (vs. "low symptom") class predicted significantly higher Eating Disorder Inventory-2 subscale scores during late adolescence. Increased vigilance for disordered eating among children who have both inattention and hyperactivity/impulsivity symptoms throughout childhood and adolescence could aid in early identification of eating disorders. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
Pelham, William E; Dishion, Thomas J; Tein, Jenn-Yun; Shaw, Daniel S; Wilson, Melvin N
2017-11-01
This study applied latent class analysis to a family-centered prevention trial in early childhood to identify subgroups of families with differential responsiveness to the Family Check-Up (FCU) intervention. The sample included 731 families with 2-year-olds randomized to the FCU or control condition and followed through age 5 with yearly follow-up assessments. A two-step mixture model was used to examine whether specific constellations of family characteristics at age 2 (baseline) were related to intervention response across ages 3, 4, and 5. The first step empirically identified latent classes of families based on several family risk and adjustment variables selected on the basis of previous research. The second step modeled the effect of the FCU on longitudinal change in children's problem behavior in each of the empirically derived latent classes. Results suggested a five-class solution, where a significant intervention effect of moderate to large size was observed in one of the five classes-the class characterized by child neglect, legal problems, and parental mental health issues. Pairwise comparisons revealed that the intervention effect was significantly greater in this class of families than in two other classes that were generally less at risk for the development of child disruptive behavior problems, albeit still low-income. Thus, findings suggest that (a) the FCU is most successful in reducing child problem behavior in more highly distressed, low-income families, and (b) the FCU may have little impact for relatively low-risk, low-income families. Future directions include the development of a brief screening process that can triage low-income families into groups that should be targeted for intervention, redirected to other services, monitored prospectively, or left alone.
ERIC Educational Resources Information Center
Hansen, Pernille
2017-01-01
This article analyses how a set of psycholinguistic factors may account for children's lexical development. Age of acquisition is compared to a measure of lexical development based on vocabulary size rather than age, and robust regression models are used to assess the individual and joint effects of word class, frequency, imageability and…
ERIC Educational Resources Information Center
Francis, Leslie J.; Gibson, Harry M.
1993-01-01
Describes a study that was conducted to investigate the influence of age, sex, social class, and religion on total television viewing time and program preferences among a large sample of Scottish secondary school students. Four main program types are examined, i.e., soap, sport, light entertainment, and current awareness. (50 references) (LRW)
Jingjing Liang; J. Buongiorno; R.A. Monserud
2005-01-01
A growth model for uneven-aged mixed-conifer stands in California was developed with data from 205 permanent plots. The model predicts the number of softwood and hardwood trees in nineteen diameter classes, based on equations for diameter growth rates, mortality arid recruitment. The model gave unbiased predictions of the expected number of trees by diameter class and...
Simulating historical variability in the amount of old forests in the Oregon Coast Range.
M.C. Wimberly; T.M. Spies; C.J. Long; C. Whitlock
2000-01-01
We developed the landscape age-class demographics simulator (LADS) to model historical variability in the amount of old-growth and late-successional forest in the Oregon Coast Range over the past 3,000 years. The model simulated temporal and spatial patterns of forest fires along with the resulting fluctuations in the distribution of forest age classes across the...
Teaching the Structure of Immunoglobulins by Molecular Visualization and SDS-PAGE Analysis
ERIC Educational Resources Information Center
Rižner, Tea Lanišnik
2014-01-01
This laboratory class combines molecular visualization and laboratory experimentation to teach the structure of the immunoglobulins (Ig). In the first part of the class, the three-dimensional structures of the human IgG and IgM molecules available through the RCSB PDB database are visualized using freely available software. In the second part, IgG…
ERIC Educational Resources Information Center
Nosow, Sigmund
This study is concerned with attitudes of family members, and whether such attitudes indeed vary with different family structures. The increasing sociological and psychiatric evidence seems to support the existence of family strengths in families which have been defined as unstable because of structural attributes. Given the historical character…
ERIC Educational Resources Information Center
Law, Yin-Kum
2014-01-01
The present study aimed to compare the effectiveness of two types of cooperative learning groups used in reciprocal teaching (RT) classes (i.e. high-structured vs. low-structured groups) for enhancing students' reading comprehension. The participants were 235 Hong Kong Chinese Grade 6 students in nine classes. Reading comprehension tests and…
A simple approach to optimal control of invasive species.
Hastings, Alan; Hall, Richard J; Taylor, Caz M
2006-12-01
The problem of invasive species and their control is one of the most pressing applied issues in ecology today. We developed simple approaches based on linear programming for determining the optimal removal strategies of different stage or age classes for control of invasive species that are still in a density-independent phase of growth. We illustrate the application of this method to the specific example of invasive Spartina alterniflora in Willapa Bay, WA. For all such systems, linear programming shows in general that the optimal strategy in any time step is to prioritize removal of a single age or stage class. The optimal strategy adjusts which class is the focus of control through time and can be much more cost effective than prioritizing removal of the same stage class each year.
Jefferis, Barbara J M H; Power, Chris; Hertzman, Clyde
2002-08-10
To examine the combined effect of social class and weight at birth on cognitive trajectories during school age and the associations between birth weight and educational outcomes through to 33 years. Longitudinal, population based, birth cohort study. 10 845 males and females born during 3-9 March 1958 with information on birth weight, social class, and cognitive tests. Reading, maths, draw a man, copying designs, verbal and non-verbal ability tests at ages 7, 11, and 16, highest qualifications achieved by 33, and trajectories of maths standardised scores at 7-16 years. The outcome of all childhood cognitive tests and educational achievements improved significantly with increasing birth weight. Analysis of maths scores at 7 and of highest qualifications achieved by 33 showed that the relations were robust to adjustment for potential confounding factors. For each kilogram increase in birth weight, maths z score increased by 0.17 (adjusted estimate 0.15, 95% confidence interval 0.10 to 0.21) for males and 0.21 (0.20, 0.14 to 0.25) for females. Trajectories of maths z scores between 7 and 16 years diverged for different social class groups: participants from classes I and II increased their relative position on the score with increasing age, whereas classes IV and V showed a relative decline with increasing age. Birth weight explained much less of the variation in cognition than did social class (range 0.5-1.5% v 2.9-12.5%). The postnatal environment has an overwhelming influence on cognitive function through to early adulthood, but these strong effects do not explain the weaker but independent association with birth weight.