Symptom variability, affect and physical activity in ambulatory persons with multiple sclerosis: Understanding patterns and time-bound relationships.

PubMed

Kasser, Susan L; Goldstein, Amanda; Wood, Phillip K; Sibold, Jeremy

2017-04-01

Individuals with multiple sclerosis (MS) experience a clinical course that is highly variable with daily fluctuations in symptoms significantly affecting functional ability and quality of life. Yet, understanding how MS symptoms co-vary and associate with physical and psychological health is unclear. The purpose of the study was to explore variability patterns and time-bound relationships across symptoms, affect, and physical activity in individuals with MS. The study employed a multivariate, replicated, single-subject repeated-measures (MRSRM) design and involved four individuals with MS. Mood, fatigue, pain, balance confidence, and losses of balance were measured daily over 28 days by self-report. Physical activity was also measured daily over this same time period via accelerometry. Dynamic factor analysis (DFA) was used to determine the dimensionality and lagged relationships across the variables. Person-specific models revealed considerable time-dependent co-variation patterns as well as pattern variation across subjects. Results also offered insight into distinct variability structures at varying levels of disability. Modeling person-level variability may be beneficial for addressing the heterogeneity of experiences in individuals with MS and for understanding temporal and dynamic interrelationships among perceived symptoms, affect, and health outcomes in this group. Copyright © 2016 Elsevier Inc. All rights reserved.

Individual variation and the endocrine regulation of behaviour and physiology in birds: a cellular/molecular perspective.

PubMed

Ball, Gregory F; Balthazart, Jacques

2008-05-12

Investigations of the cellular and molecular mechanisms of physiology and behaviour have generally avoided attempts to explain individual differences. The goal has rather been to discover general processes. However, understanding the causes of individual variation in many phenomena of interest to avian eco-physiologists will require a consideration of such mechanisms. For example, in birds, changes in plasma concentrations of steroid hormones are important in the activation of social behaviours related to reproduction and aggression. Attempts to explain individual variation in these behaviours as a function of variation in plasma hormone concentrations have generally failed. Cellular variables related to the effectiveness of steroid hormone have been useful in some cases. Steroid hormone target sensitivity can be affected by variables such as metabolizing enzyme activity, hormone receptor expression as well as receptor cofactor expression. At present, no general theory has emerged that might provide a clear guidance when trying to explain individual variability in birds or in any other group of vertebrates. One strategy is to learn from studies of large units of intraspecific variation such as population or sex differences to provide ideas about variables that might be important in explaining individual variation. This approach along with the use of newly developed molecular genetic tools represents a promising avenue for avian eco-physiologists to pursue.

Multifactor leadership styles and new exposure to workplace bullying: a six-month prospective study

PubMed Central

TSUNO, Kanami; KAWAKAMI, Norito

2014-01-01

This study investigated the prospective association between supervisor leadership styles and workplace bullying. Altogether 404 civil servants from a local government in Japan completed baseline and follow-up surveys. The leadership variables and exposure to bullying were measured by Multifactor Leadership Questionnaire and Negative Acts Questionnaire-Revised, respectively. The prevalence of workplace bullying was 14.8% at baseline and 15.1% at follow-up. Among respondents who did not experience bullying at baseline (n=216), those who worked under the supervisors as higher in passive laissez-faire leadership had a 4.3 times higher risk of new exposure to bullying. On the other hand, respondents whose supervisors with highly considerate of the individual had a 70% lower risk of new exposure to bullying. In the entire sample (n=317), passive laissez-faire leadership was significantly and positively associated, while charisma/inspiration, individual consideration, and contingent reward were negatively associated both after adjusting for demographic and occupational characteristics at baseline, life events during follow-up, and exposure to workplace bullying at baseline. Results indicated that passive laissez-faire and low individual consideration leadership style at baseline were strong predictors of new exposure to bullying and high individual consideration leadership of supervisors/managers could be a preventive factor against bullying. PMID:25382384

Multifactor leadership styles and new exposure to workplace bullying: a six-month prospective study.

PubMed

Tsuno, Kanami; Kawakami, Norito

2015-01-01

This study investigated the prospective association between supervisor leadership styles and workplace bullying. Altogether 404 civil servants from a local government in Japan completed baseline and follow-up surveys. The leadership variables and exposure to bullying were measured by Multifactor Leadership Questionnaire and Negative Acts Questionnaire-Revised, respectively. The prevalence of workplace bullying was 14.8% at baseline and 15.1% at follow-up. Among respondents who did not experience bullying at baseline (n=216), those who worked under the supervisors as higher in passive laissez-faire leadership had a 4.3 times higher risk of new exposure to bullying. On the other hand, respondents whose supervisors with highly considerate of the individual had a 70% lower risk of new exposure to bullying. In the entire sample (n=317), passive laissez-faire leadership was significantly and positively associated, while charisma/inspiration, individual consideration, and contingent reward were negatively associated both after adjusting for demographic and occupational characteristics at baseline, life events during follow-up, and exposure to workplace bullying at baseline. Results indicated that passive laissez-faire and low individual consideration leadership style at baseline were strong predictors of new exposure to bullying and high individual consideration leadership of supervisors/managers could be a preventive factor against bullying.

Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour

PubMed Central

Vogel, David; Nicolis, Stamatios C.; Perez-Escudero, Alfonso; Nanjundiah, Vidyanand; Sumpter, David J. T.; Dussutour, Audrey

2015-01-01

Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum. We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: ‘slow–regular–social’, ‘fast–regular–social’ and ‘fast–irregular–asocial’. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms. PMID:26609088

Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour.

PubMed

Vogel, David; Nicolis, Stamatios C; Perez-Escudero, Alfonso; Nanjundiah, Vidyanand; Sumpter, David J T; Dussutour, Audrey

2015-11-22

Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum. We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: 'slow-regular-social', 'fast-regular-social' and 'fast-irregular-asocial'. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms. © 2015 The Author(s).

Host-dependent variables: The missing link to personalized medicine.

PubMed

Demlova, Regina; Zdrazilova-Dubska, Lenka; Sterba, Jaroslav; Stanta, Giorgio; Valik, Dalibor

2018-04-26

Individualized medicine has the potential to tailor anticancer therapy with the best response and highest safety margin to provide better patient care. However, modern targeted therapies are still being tested through clinical trials comparing preselected patient cohorts and assessed upon behaviour of group averages. Clinically manifesting malignant disease requires identification of host- and tumour-dependent variables such as biological characteristics of the tumour and its microenvironment including immune response features, and overall capacity of the host to receive, tolerate and efficiently utilize treatment. Contemporary medical oncology including clinical trial design need to refocus from assessing group averages to individuality taking into consideration time dependent host-associated characteristics and reinventing outliers to be appreciated as naturally occurring variables collectively determining the ultimate outcome of malignant disease. Copyright © 2018. Published by Elsevier Ltd.

Variability of perceptual multistability: from brain state to individual trait

PubMed Central

Kleinschmidt, Andreas; Sterzer, Philipp; Rees, Geraint

2012-01-01

Few phenomena are as suitable as perceptual multistability to demonstrate that the brain constructively interprets sensory input. Several studies have outlined the neural circuitry involved in generating perceptual inference but only more recently has the individual variability of this inferential process been appreciated. Studies of the interaction of evoked and ongoing neural activity show that inference itself is not merely a stimulus-triggered process but is related to the context of the current brain state into which the processing of external stimulation is embedded. As brain states fluctuate, so does perception of a given sensory input. In multistability, perceptual fluctuation rates are consistent for a given individual but vary considerably between individuals. There has been some evidence for a genetic basis for these individual differences and recent morphometric studies of parietal lobe regions have identified neuroanatomical substrates for individual variability in spontaneous switching behaviour. Moreover, disrupting the function of these latter regions by transcranial magnetic stimulation yields systematic interference effects on switching behaviour, further arguing for a causal role of these regions in perceptual inference. Together, these studies have advanced our understanding of the biological mechanisms by which the brain constructs the contents of consciousness from sensory input. PMID:22371620

Quantifying interindividual variability and asymmetry of face-selective regions: a probabilistic functional atlas.

PubMed

Zhen, Zonglei; Yang, Zetian; Huang, Lijie; Kong, Xiang-Zhen; Wang, Xu; Dang, Xiaobin; Huang, Yangyue; Song, Yiying; Liu, Jia

2015-06-01

Face-selective regions (FSRs) are among the most widely studied functional regions in the human brain. However, individual variability of the FSRs has not been well quantified. Here we use functional magnetic resonance imaging (fMRI) to localize the FSRs and quantify their spatial and functional variabilities in 202 healthy adults. The occipital face area (OFA), posterior and anterior fusiform face areas (pFFA and aFFA), posterior continuation of the superior temporal sulcus (pcSTS), and posterior and anterior STS (pSTS and aSTS) were delineated for each individual with a semi-automated procedure. A probabilistic atlas was constructed to characterize their interindividual variability, revealing that the FSRs were highly variable in location and extent across subjects. The variability of FSRs was further quantified on both functional (i.e., face selectivity) and spatial (i.e., volume, location of peak activation, and anatomical location) features. Considerable interindividual variability and rightward asymmetry were found in all FSRs on these features. Taken together, our work presents the first effort to characterize comprehensively the variability of FSRs in a large sample of healthy subjects, and invites future work on the origin of the variability and its relation to individual differences in behavioral performance. Moreover, the probabilistic functional atlas will provide an adequate spatial reference for mapping the face network. Copyright © 2015 Elsevier Inc. All rights reserved.

A Model of Effective Teaching in Arts, Humanities, and Social Sciences

ERIC Educational Resources Information Center

Tahir, Khazima; Ikram, Hamid; Economos, Jennifer; Morote, Elsa-Sophia; Inserra, Albert

2017-01-01

The purpose of this study was to examine how graduate students with undergraduate majors in arts, humanities, and social sciences perceived individualized consideration, Student-Professor Engagement in Learning (SPEL), intellectual stimulation, and student deep learning, and how these variables predict effective teaching. A sample of 251 graduate…

Genome-wide association study for feed efficiency traits using SNP and haplotype models

USDA-ARS?s Scientific Manuscript database

Feed costs comprise the majority of variable expenses in beef cattle systems making feed efficiency an important economic consideration within the beef industry. Due to the expense of recording individual feed intake phenotypes, a genomic-enabled approach could be advantageous towards improving this...

Adaptive Educational Hypermedia Accommodating Learning Styles: A Content Analysis of Publications from 2000 to 2011

ERIC Educational Resources Information Center

Akbulut, Yavuz; Cardak, Cigdem Suzan

2012-01-01

Implementing instructional interventions to accommodate learner differences has received considerable attention. Among these individual difference variables, the empirical evidence regarding the pedagogical value of learning styles has been questioned, but the research on the issue continues. Recent developments in Web-based implementations have…

Understanding Successful and Unsuccessful EFL Students in Chinese Universities

ERIC Educational Resources Information Center

Gan, Zhengdong; Humphreys, Gillian; Hamp-Lyons, Liz

2004-01-01

Unlike success in first language acquisition, success in learning a second or foreign language is considerably more variable. Recently, second language acquisition researchers have called for more integrative research on individual difference factors. With this goal in mind, this study followed a larger, quantitative study of the links between…

[Ethics and prevention: environmental and individual disparities].

PubMed

Ricciardi, Claudio

2004-01-01

The complex interactions which exist between environmental variabilities, genetic susceptibility of population subgroups, and high individual variability for age, sex, gender, ethnicity and general status of health, acquire an ever-increasing bioethical significance. Different risk conditions caused by toxic environmental agents and environmental inequities and inequalities are increasingly evident. "Social determinants" of health increase the probability of health effects and an effective intervention of prevision and prevention for environmental pathologies is needed. The debate on environmental inequalities caused by cultural, social and economic factors and the uncertainty about possible prevention emphasize the limits of the "bio-medical model". Ethics with its further anthropological and philosophical considerations may strongly help to understand the relationship between environmental pollution and health.

Functional Brain Networks Are Dominated by Stable Group and Individual Factors, Not Cognitive or Daily Variation.

PubMed

Gratton, Caterina; Laumann, Timothy O; Nielsen, Ashley N; Greene, Deanna J; Gordon, Evan M; Gilmore, Adrian W; Nelson, Steven M; Coalson, Rebecca S; Snyder, Abraham Z; Schlaggar, Bradley L; Dosenbach, Nico U F; Petersen, Steven E

2018-04-18

The organization of human brain networks can be measured by capturing correlated brain activity with fMRI. There is considerable interest in understanding how brain networks vary across individuals or neuropsychiatric populations or are altered during the performance of specific behaviors. However, the plausibility and validity of such measurements is dependent on the extent to which functional networks are stable over time or are state dependent. We analyzed data from nine high-quality, highly sampled individuals to parse the magnitude and anatomical distribution of network variability across subjects, sessions, and tasks. Critically, we find that functional networks are dominated by common organizational principles and stable individual features, with substantially more modest contributions from task-state and day-to-day variability. Sources of variation were differentially distributed across the brain and differentially linked to intrinsic and task-evoked sources. We conclude that functional networks are suited to measuring stable individual characteristics, suggesting utility in personalized medicine. Copyright © 2018 Elsevier Inc. All rights reserved.

The ribosomal subunit assembly line

PubMed Central

Dlakić, Mensur

2005-01-01

Recent proteomic studies in Saccharomyces cerevisiae have identified nearly 200 proteins, other than the structural ribosomal proteins, that participate in the assembly of ribosomal subunits and their transport from the nucleus. In a separate line of research, proteomic studies of mature plant ribosomes have revealed considerable variability in the protein composition of individual ribosomes. PMID:16207363

Exploring Prospective EFL Teachers' Perceived Self-Efficacy and Beliefs on English Language Learning

ERIC Educational Resources Information Center

Genç, Gülten; Kulusakli, Emine; Aydin, Savas

2016-01-01

Learners' perceived self-efficacy and beliefs on English language learning are important in education. Taking into consideration the important impact of individual variables on language learning, this study seeks to highlight the relationship between Turkish EFL learners' beliefs about language learning and their sense of self-efficacy. The…

Design of Experiments with Multiple Independent Variables: A Resource Management Perspective on Complete and Reduced Factorial Designs

PubMed Central

Collins, Linda M.; Dziak, John J.; Li, Runze

2009-01-01

An investigator who plans to conduct experiments with multiple independent variables must decide whether to use a complete or reduced factorial design. This article advocates a resource management perspective on making this decision, in which the investigator seeks a strategic balance between service to scientific objectives and economy. Considerations in making design decisions include whether research questions are framed as main effects or simple effects; whether and which effects are aliased (confounded) in a particular design; the number of experimental conditions that must be implemented in a particular design and the number of experimental subjects the design requires to maintain the desired level of statistical power; and the costs associated with implementing experimental conditions and obtaining experimental subjects. In this article four design options are compared: complete factorial, individual experiments, single factor, and fractional factorial designs. Complete and fractional factorial designs and single factor designs are generally more economical than conducting individual experiments on each factor. Although relatively unfamiliar to behavioral scientists, fractional factorial designs merit serious consideration because of their economy and versatility. PMID:19719358

Characterizing Individual Differences in Functional Connectivity Using Dual-Regression and Seed-Based Approaches

PubMed Central

Smith, David V.; Utevsky, Amanda V.; Bland, Amy R.; Clement, Nathan; Clithero, John A.; Harsch, Anne E. W.; Carter, R. McKell; Huettel, Scott A.

2014-01-01

A central challenge for neuroscience lies in relating inter-individual variability to the functional properties of specific brain regions. Yet, considerable variability exists in the connectivity patterns between different brain areas, potentially producing reliable group differences. Using sex differences as a motivating example, we examined two separate resting-state datasets comprising a total of 188 human participants. Both datasets were decomposed into resting-state networks (RSNs) using a probabilistic spatial independent components analysis (ICA). We estimated voxelwise functional connectivity with these networks using a dual-regression analysis, which characterizes the participant-level spatiotemporal dynamics of each network while controlling for (via multiple regression) the influence of other networks and sources of variability. We found that males and females exhibit distinct patterns of connectivity with multiple RSNs, including both visual and auditory networks and the right frontal-parietal network. These results replicated across both datasets and were not explained by differences in head motion, data quality, brain volume, cortisol levels, or testosterone levels. Importantly, we also demonstrate that dual-regression functional connectivity is better at detecting inter-individual variability than traditional seed-based functional connectivity approaches. Our findings characterize robust—yet frequently ignored—neural differences between males and females, pointing to the necessity of controlling for sex in neuroscience studies of individual differences. Moreover, our results highlight the importance of employing network-based models to study variability in functional connectivity. PMID:24662574

The influence of individualism and drinking identity on alcohol problems.

PubMed

Foster, Dawn W; Yeung, Nelson; Quist, Michelle C

2014-12-01

This study evaluated the interactive association between individualism and drinking identity predicting alcohol use and problems. Seven hundred and ten undergraduates (Mean age =22.84, SD = 5.31, 83.1% female) completed study materials. We expected that drinking identity and individualism would positively correlate with drinking variables. We further expected that individualism would moderate the association between drinking identity and drinking such that the relationship between drinking identity and alcohol outcomes would be positively associated, particularly among those high in individualism. Our findings supported our hypotheses. These findings better explain the relationship between drinking identity, individualism, and alcohol use. Furthermore, this research encourages the consideration of individual factors and personality characteristics in order to develop culturally tailored materials to maximize intervention efficacy across cultures.

Modelling the co-evolution of indirect genetic effects and inherited variability.

PubMed

Marjanovic, Jovana; Mulder, Han A; Rönnegård, Lars; Bijma, Piter

2018-03-28

When individuals interact, their phenotypes may be affected not only by their own genes but also by genes in their social partners. This phenomenon is known as Indirect Genetic Effects (IGEs). In aquaculture species and some plants, however, competition not only affects trait levels of individuals, but also inflates variability of trait values among individuals. In the field of quantitative genetics, the variability of trait values has been studied as a quantitative trait in itself, and is often referred to as inherited variability. Such studies, however, consider only the genetic effect of the focal individual on trait variability and do not make a connection to competition. Although the observed phenotypic relationship between competition and variability suggests an underlying genetic relationship, the current quantitative genetic models of IGE and inherited variability do not allow for such a relationship. The lack of quantitative genetic models that connect IGEs to inherited variability limits our understanding of the potential of variability to respond to selection, both in nature and agriculture. Models of trait levels, for example, show that IGEs may considerably change heritable variation in trait values. Currently, we lack the tools to investigate whether this result extends to variability of trait values. Here we present a model that integrates IGEs and inherited variability. In this model, the target phenotype, say growth rate, is a function of the genetic and environmental effects of the focal individual and of the difference in trait value between the social partner and the focal individual, multiplied by a regression coefficient. The regression coefficient is a genetic trait, which is a measure of cooperation; a negative value indicates competition, a positive value cooperation, and an increasing value due to selection indicates the evolution of cooperation. In contrast to the existing quantitative genetic models, our model allows for co-evolution of IGEs and variability, as the regression coefficient can respond to selection. Our simulations show that the model results in increased variability of body weight with increasing competition. When competition decreases, i.e., cooperation evolves, variability becomes significantly smaller. Hence, our model facilitates quantitative genetic studies on the relationship between IGEs and inherited variability. Moreover, our findings suggest that we may have been overlooking an entire level of genetic variation in variability, the one due to IGEs.

Nonsense-mediated mRNA decay: inter-individual variability and human disease

PubMed Central

Nguyen, Lam Son; Wilkinson, Miles; Gecz, Jozef

2013-01-01

Nonsense-Mediated mRNA Decay (NMD) is a regulatory pathway that functions to degrade transcripts containing premature termination codons (PTCs) and to maintain normal transcriptome homeostasis. Nonsense and frameshift mutations that generate PTCs cause approximately one-third of all known human genetic diseases and thus NMD has a potentially important role in human disease. In genetic disorders in which the affected genes carry PTC-generating mutations, NMD acts as a double-edge sword. While it can benefit the patient by degrading PTC-containing mRNAs that encode detrimental, dominant-negative truncated proteins, it can also make the disease worse when a PTC-containing mRNA is degraded that encodes a mutant but still functional protein. There is evidence that the magnitude of NMD varies between individuals, which, in turn, has been shown to correlate with both clinical presentations and the patients’ responses to drugs that promote read-through of PTCs. In this review, we examine the evidence supporting the existence of inter-individual variability in NMD efficiency and discuss the genetic factors that underlie this variability. We propose that inter-individual variability in NMD efficiency is a common phenomenon in human populations and that an individual’s NMD efficiency should be taken into consideration when testing, developing, and making therapeutic decisions for diseases caused by genes harboring PTCs. PMID:24239855

Individual and contextual factors related to dental caries in underprivileged Brazilian adolescents.

PubMed

Vazquez, Fabiana de Lima; Cortellazzi, Karine Laura; Kaieda, Armando Koichiro; Bulgareli, Jaqueline Vilela; Mialhe, Fabio Luiz; Ambrosano, Glaucia Maria Bovi; da Silva Tagliaferro, Elaine Pereira; Guerra, Luciane Miranda; de Castro Meneghim, Marcelo; Pereira, Antonio Carlos

2015-01-20

Investigate the individual and contextual variables related to caries in underprivileged adolescents, and the disparity in distribution of the disease. Cross-sectional analytical study, conducted in the city of Piracicaba, SP, Brazil, in 2012. The probabilistic sample was composed of 1,179 adolescents from 15-19 years of age, randomly selected from 21 state schools and 34 Primary Health Units--Family Health (PHU-FH). The dependent variables studied were number of decayed teeth and caries experience (DMFT). The independent variables were classified into individual (clinical, sociodemographic, psychosocial, self-perception, impact on oral health, access to services, and quality of life) and contextual (social exclusion index, total number of residents in suburb, literacy rate, and the following variables given in percentages: residences in the home ownership category, provision of domestic sewerage, trash collection, families with income of over 1 minimum wage per month, and families without monthly income) variables. The multilevel regression model was estimated by the PROC GLIMMIX (Generalized Linear Models-Mixed) procedure, considering the individual variables as Level 1 and the contextual variables of the suburbs as Level 2. Adjustment of the model was evaluated by -2 Res Log Likelihood with α = 0.05. As regards the individual variables, adolescents who declared having a prison inmate in the Family and resided in homes with a larger number of persons, showed a higher number of decayed teeth. There were a larger number of decayed teeth, a higher DMFT value, and worse self-perception as regards the health of their teeth and mouth. Other variables, such as being of the female gender, age and time since last visit to the dentist were related to the DMFT index. As regards the contextual variables, the DMFT was lower in suburbs with greater access to domestic sewage, and the number of decayed teeth was higher in suburbs with the worst social exclusion indices. Individual and contextual variables were associated with the presence of caries and DMFT index in underprivileged adolescents, indicating that they must be taken into consideration in the formulation of policies directed towards oral health promotion and prevention activities in this group.

The Effect of Working Memory Capacity Limitations on the Intuitive Assessment of Correlation: Amplification, Attenuation, or Both?

ERIC Educational Resources Information Center

Cahan, Sorel; Mor, Yaniv

2007-01-01

This article challenges Yaakov Kareev's (1995a, 2000) argument regarding the positive bias of intuitive correlation estimates due to working memory capacity limitations and its adaptive value. The authors show that, under narrow window theory's primacy effect assumption, there is a considerable between-individual variability of the effects of…

How Do Task Characteristics Affect Learning and Performance? The Roles of Variably Mapped and Dynamic Tasks

ERIC Educational Resources Information Center

Macnamara, Brooke N.; Frank, David J.

2018-01-01

For well over a century, scientists have investigated individual differences in performance. The majority of studies have focused on either differences in practice, or differences in cognitive resources. However, the predictive ability of either practice or cognitive resources varies considerably across tasks. We are the first to examine task…

Fluctuations in Unimanual Hand Preference in Infants Following the Onset of Duplicated Syllable Babbling.

ERIC Educational Resources Information Center

Ramsay, Douglas S.

1985-01-01

Infants were tested for unimanual handedness at weekly intervals for a 14-week period beginning with the week of onset of duplicated syllable babbling. Group analyses indicating effects of sex and/or birth order on fluctuations and date review for individual infants suggested considerable variability across infants in occurrence and/or timing of…

Covariates of the Rating Process in Hierarchical Models for Multiple Ratings of Test Items

ERIC Educational Resources Information Center

Mariano, Louis T.; Junker, Brian W.

2007-01-01

When constructed response test items are scored by more than one rater, the repeated ratings allow for the consideration of individual rater bias and variability in estimating student proficiency. Several hierarchical models based on item response theory have been introduced to model such effects. In this article, the authors demonstrate how these…

Discerning the impact of personal and situational variables in risk perception of coronary heart disease.

PubMed

Figueiras, Maria João; Maroco, João; Monteiro, Rita; Caeiro, Raúl; Neto, David D

2017-03-01

Research into how people perceive risk has highlighted the interaction between the available information and personal variables and their impact on judgement. This study sought to identify demographic and health variables that influenced risk and the influence of individual risk assessment, dispositional optimism and negative affect on judgement. A total of 476 participants were asked to make risks judgements of 24 vignettes depicting hypothetical risk scenarios. The findings showed that while people are able to correctly recognise, in others, relevant risk factors for coronary heart disease, risk perception is likely to imply a personal consideration of the same risk factors in themselves.

Analysis of the influences on plumage condition in laying hens: How suitable is a whole body plumage score as an outcome?

PubMed

Campe, A; Hoes, C; Koesters, S; Froemke, C; Bougeard, S; Staack, M; Bessei, W; Manton, A; Scholz, B; Schrader, L; Thobe, P; Knierim, U

2018-02-01

An important indicator of the health and behavior of laying hens is their plumage condition. Various scoring systems are used, and various risk factors for feather damage have been described. Often, a summarized score of different body parts is used to describe the overall condition of the plumage of a bird. However, it has not yet been assessed whether such a whole body plumage score is a suitable outcome variable when analyzing the risk factors for plumage deterioration. Data collected within a German project on farms keeping laying hens in aviaries were analyzed to investigate whether and the extent to which information is lost when summarizing the scores of the separate body parts. Two models were fitted using multiblock redundancy analysis, in which the first model included the whole body score as one outcome variable, while the second model included the scores of the individual body parts as multiple outcome variables. Although basically similar influences could be discovered with both models, the investigation of the individual body parts allowed for consideration of the influences on each body part separately and for the identification of additional influences. Furthermore, ambivalent influences (a factor differently associated with 2 different outcomes) could be detected with this approach, and possible dilutive effects were avoided. We conclude that influences might be underestimated or even missed when modeling their explanatory power for an overall score only. Therefore, multivariate methods that allow for the consideration of individual body parts are an interesting option when investigating influences on plumage condition. © 2017 Poultry Science Association Inc.

Population pharmacokinetic study of memantine: effects of clinical and genetic factors.

PubMed

Noetzli, Muriel; Guidi, Monia; Ebbing, Karsten; Eyer, Stephan; Wilhelm, Laurence; Michon, Agnès; Thomazic, Valérie; Alnawaqil, Abdel-Messieh; Maurer, Sophie; Zumbach, Serge; Giannakopoulos, Panteleimon; von Gunten, Armin; Csajka, Chantal; Eap, Chin B

2013-03-01

Memantine, a frequently prescribed anti-dementia drug, is mainly eliminated unchanged by the kidneys, partly via tubular secretion. Considerable inter-individual variability in plasma concentrations has been reported. We aimed to investigate clinical and genetic factors influencing memantine disposition. A population pharmacokinetic study was performed including data from 108 patients recruited in a naturalistic setting. Patients were genotyped for common polymorphisms in renal cation transporters (SLC22A1/2/5, SLC47A1, ABCB1) and nuclear receptors (NR1I2, NR1I3, RXR, PPAR) involved in transporter expression. The average clearance was 5.2 L/h with a 27 % inter-individual variability (percentage coefficient of variation). Glomerular filtration rate (p = 0.007) and sex (p = 0.001) markedly influenced memantine clearance. NR1I2 rs1523130 was identified as the unique significant genetic covariate for memantine clearance (p = 0.006), with carriers of the NR1I2 rs1523130 CT/TT genotypes presenting a 16 % slower memantine elimination than carriers of the CC genotype. The better understanding of inter-individual variability of memantine disposition might be beneficial in the context of individual dose optimization.

The influence of individualism and drinking identity on alcohol problems

PubMed Central

Foster, Dawn W.; Yeung, Nelson; Quist, Michelle C.

2014-01-01

This study evaluated the interactive association between individualism and drinking identity predicting alcohol use and problems. Seven hundred and ten undergraduates (Mean age =22.84, SD = 5.31, 83.1% female) completed study materials. We expected that drinking identity and individualism would positively correlate with drinking variables. We further expected that individualism would moderate the association between drinking identity and drinking such that the relationship between drinking identity and alcohol outcomes would be positively associated, particularly among those high in individualism. Our findings supported our hypotheses. These findings better explain the relationship between drinking identity, individualism, and alcohol use. Furthermore, this research encourages the consideration of individual factors and personality characteristics in order to develop culturally tailored materials to maximize intervention efficacy across cultures. PMID:25525420

Associations between dopamine D4 receptor gene variation with both infidelity and sexual promiscuity.

PubMed

Garcia, Justin R; MacKillop, James; Aller, Edward L; Merriwether, Ann M; Wilson, David Sloan; Lum, J Koji

2010-11-30

Human sexual behavior is highly variable both within and between populations. While sex-related characteristics and sexual behavior are central to evolutionary theory (sexual selection), little is known about the genetic bases of individual variation in sexual behavior. The variable number tandem repeats (VNTR) polymorphism in exon III of the human dopamine D4 receptor gene (DRD4) has been correlated with an array of behavioral phenotypes and may be predicatively responsible for variation in motivating some sexual behaviors, particularly promiscuity and infidelity. We administered an anonymous survey on personal history of sexual behavior and intimate relationships to 181 young adults. We also collected buccal wash samples and genotyped the DRD4 VNTR. Here we show that individuals with at least one 7-repeat allele (7R+) report a greater categorical rate of promiscuous sexual behavior (i.e., having ever had a "one-night stand") and report a more than 50% increase in instances of sexual infidelity. DRD4 VNTR genotype varies considerably within and among populations and has been subject to relatively recent, local selective pressures. Individual differences in sexual behavior are likely partially mediated by individual genetic variation in genes coding for motivation and reward in the brain. Conceptualizing these findings in terms of r/K selection theory suggests a mechanism for selective pressure for and against the 7R+ genotype that may explain the considerable global allelic variation for this polymorphism.

Associations between Dopamine D4 Receptor Gene Variation with Both Infidelity and Sexual Promiscuity

PubMed Central

Garcia, Justin R.; MacKillop, James; Aller, Edward L.; Merriwether, Ann M.; Wilson, David Sloan; Lum, J. Koji

2010-01-01

Background Human sexual behavior is highly variable both within and between populations. While sex-related characteristics and sexual behavior are central to evolutionary theory (sexual selection), little is known about the genetic bases of individual variation in sexual behavior. The variable number tandem repeats (VNTR) polymorphism in exon III of the human dopamine D4 receptor gene (DRD4) has been correlated with an array of behavioral phenotypes and may be predicatively responsible for variation in motivating some sexual behaviors, particularly promiscuity and infidelity. Methodology/Principal Findings We administered an anonymous survey on personal history of sexual behavior and intimate relationships to 181 young adults. We also collected buccal wash samples and genotyped the DRD4 VNTR. Here we show that individuals with at least one 7-repeat allele (7R+) report a greater categorical rate of promiscuous sexual behavior (i.e., having ever had a “one-night stand”) and report a more than 50% increase in instances of sexual infidelity. Conclusions/Significance DRD4 VNTR genotype varies considerably within and among populations and has been subject to relatively recent, local selective pressures. Individual differences in sexual behavior are likely partially mediated by individual genetic variation in genes coding for motivation and reward in the brain. Conceptualizing these findings in terms of r/K selection theory suggests a mechanism for selective pressure for and against the 7R+ genotype that may explain the considerable global allelic variation for this polymorphism. PMID:21152404

Reproducibility of Interferon Gamma (IFN-γ) Release Assays. A Systematic Review

PubMed Central

Tagmouti, Saloua; Slater, Madeline; Benedetti, Andrea; Kik, Sandra V.; Banaei, Niaz; Cattamanchi, Adithya; Metcalfe, John; Dowdy, David; van Zyl Smit, Richard; Dendukuri, Nandini

2014-01-01

Rationale: Interferon gamma (IFN-γ) release assays for latent tuberculosis infection result in a larger-than-expected number of conversions and reversions in occupational screening programs, and reproducibility of test results is a concern. Objectives: Knowledge of the relative contribution and extent of the individual sources of variability (immunological, preanalytical, or analytical) could help optimize testing protocols. Methods: We performed a systematic review of studies published by October 2013 on all potential sources of variability of commercial IFN-γ release assays (QuantiFERON-TB Gold In-Tube and T-SPOT.TB). The included studies assessed test variability under identical conditions and under different conditions (the latter both overall and stratified by individual sources of variability). Linear mixed effects models were used to estimate within-subject SD. Measurements and Main Results: We identified a total of 26 articles, including 7 studies analyzing variability under the same conditions, 10 studies analyzing variability with repeat testing over time under different conditions, and 19 studies reporting individual sources of variability. Most data were on QuantiFERON (only three studies on T-SPOT.TB). A considerable number of conversions and reversions were seen around the manufacturer-recommended cut-point. The estimated range of variability of IFN-γ response in QuantiFERON under identical conditions was ±0.47 IU/ml (coefficient of variation, 13%) and ±0.26 IU/ml (30%) for individuals with an initial IFN-γ response in the borderline range (0.25–0.80 IU/ml). The estimated range of variability in noncontrolled settings was substantially larger (±1.4 IU/ml; 60%). Blood volume inoculated into QuantiFERON tubes and preanalytic delay were identified as key sources of variability. Conclusions: This systematic review shows substantial variability with repeat IFN-γ release assays testing even under identical conditions, suggesting that reversions and conversions around the existing cut-point should be interpreted with caution. PMID:25188809

Characterizing individual differences in functional connectivity using dual-regression and seed-based approaches.

PubMed

Smith, David V; Utevsky, Amanda V; Bland, Amy R; Clement, Nathan; Clithero, John A; Harsch, Anne E W; McKell Carter, R; Huettel, Scott A

2014-07-15

A central challenge for neuroscience lies in relating inter-individual variability to the functional properties of specific brain regions. Yet, considerable variability exists in the connectivity patterns between different brain areas, potentially producing reliable group differences. Using sex differences as a motivating example, we examined two separate resting-state datasets comprising a total of 188 human participants. Both datasets were decomposed into resting-state networks (RSNs) using a probabilistic spatial independent component analysis (ICA). We estimated voxel-wise functional connectivity with these networks using a dual-regression analysis, which characterizes the participant-level spatiotemporal dynamics of each network while controlling for (via multiple regression) the influence of other networks and sources of variability. We found that males and females exhibit distinct patterns of connectivity with multiple RSNs, including both visual and auditory networks and the right frontal-parietal network. These results replicated across both datasets and were not explained by differences in head motion, data quality, brain volume, cortisol levels, or testosterone levels. Importantly, we also demonstrate that dual-regression functional connectivity is better at detecting inter-individual variability than traditional seed-based functional connectivity approaches. Our findings characterize robust-yet frequently ignored-neural differences between males and females, pointing to the necessity of controlling for sex in neuroscience studies of individual differences. Moreover, our results highlight the importance of employing network-based models to study variability in functional connectivity. Copyright © 2014 Elsevier Inc. All rights reserved.

The incidence of training responsiveness to cardiorespiratory fitness and cardiometabolic measurements following individualized and standardized exercise prescription: study protocol for a randomized controlled trial.

PubMed

Weatherwax, Ryan M; Harris, Nigel K; Kilding, Andrew E; Dalleck, Lance C

2016-12-19

There is individual variability to cardiorespiratory fitness (CRF) training, but the underlying cause is not well understood. Traditionally, a standardized approach to exercise prescription has utilized relative percentages of maximal heart rate, heart rate reserve (HRR), maximal oxygen uptake (VO 2 max), or VO 2 reserve to establish exercise intensity. However, this model fails to take into consideration individual metabolic responses to exercise and may attribute to the variability in training responses. It has been proposed that an individualized approach would take into consideration metabolic responses to exercises to increase responsiveness to training. In this randomized control trial, participants will undergo a 12-week exercise intervention using individualized (ventilatory thresholds) and standardized (HRR) methods to prescribe CRF training intensity. Following the intervention, participants will be categorized as responders or non-responders based on changes in maximal aerobic abilities. Participants who are non-responders will complete a second 12-week intervention in a crossover design to determine whether they can become responders with a differing exercise prescription. There are four main research outcomes: (1) determine the cohort-specific technical error to use in the categorization of response rate; (2) determine if an individualized intensity prescription is superior to a standard approach in regards to VO 2 max and cardiometabolic risk factors; (3) investigate the time course changes throughout 12 weeks of CRF training between the two intervention groups; and (4) determine if non-responders can become responders if the exercise prescription is modified. The findings from this research will provide evidence on the effectiveness of individualized exercise prescription related to training responsiveness of VO 2 max and cardiometabolic risk factors compared to a standardized approach and further our understanding of individual exercise responses. If the individualized approach proposed is deemed effective, it may change the way exercise specialists prescribe exercise intensity to enhance training responsiveness. ClinicalTrials.gov, NCT02868710 . Registered on 15 August 2016.

Individualized treatment with transcranial direct current stimulation in patients with chronic non-fluent aphasia due to stroke

PubMed Central

Shah-Basak, Priyanka P.; Norise, Catherine; Garcia, Gabriella; Torres, Jose; Faseyitan, Olufunsho; Hamilton, Roy H.

2015-01-01

While evidence suggests that transcranial direct current stimulation (tDCS) may facilitate language recovery in chronic post-stroke aphasia, individual variability in patient response to different patterns of stimulation remains largely unexplored. We sought to characterize this variability among chronic aphasic individuals, and to explore whether repeated stimulation with an individualized optimal montage could lead to persistent reduction of aphasia severity. In a two-phase study, we first stimulated patients with four active montages (left hemispheric anode or cathode; right hemispheric anode or cathode) and one sham montage (Phase 1). We examined changes in picture naming ability to address (1) variability in response to different montages among our patients, and (2) whether individual patients responded optimally to at least one montage. During Phase 2, subjects who responded in Phase 1 were randomized to receive either real-tDCS or to receive sham stimulation (10 days); patients who were randomized to receive sham stimulation first were then crossed over to receive real-tDCS (10 days). In both phases, 2 mA tDCS was administered for 20 min per real-tDCS sessions and patients performed a picture naming task during stimulation. Patients' language ability was re-tested after 2-weeks and 2-months following real and sham tDCS in Phase 2. In Phase 1, despite considerable individual variability, the greatest average improvement was observed after left-cathodal stimulation. Seven out of 12 subjects responded optimally to at least one montage as demonstrated by transient improvement in picture-naming. In Phase 2, aphasia severity improved at 2-weeks and 2-months following real-tDCS but not sham. Despite individual variability with respect to optimal tDCS approach, certain montages result in consistent transient improvement in persons with chronic post-stroke aphasia. This preliminary study supports the notion that individualized tDCS treatment may enhance aphasia recovery in a persistent manner. PMID:25954178

Sampling capacity underlies individual differences in human associative learning.

PubMed

Byrom, Nicola C; Murphy, Robin A

2014-04-01

Though much work has studied how external factors, such as stimulus properties, influence generalization of associative strength, there has been limited exploration of the influence that internal dispositions may contribute to stimulus processing. Here we report 2 studies using a modified negative patterning discrimination to test the relationship between global processing and generalization. Global processing was associated with stronger negative patterning discrimination, indicative of limited generalization between distinct stimulus compounds and their constituent elements. In Experiment 2, participants pretrained to adopt global processing similarly showed strong negative patterning discrimination. These results demonstrate considerable individual difference in capacity to engage in negative patterning discrimination and suggest that the tendency toward global processing may be one factor explaining this variability. The need for models of learning to account for this variability in learning is discussed.

[Individual characteristics of correction of the cosmonauts' vegetative status with a method of adaptive biofeedback

NASA Technical Reports Server (NTRS)

Kornilova, L. N.; Cowings, P.; Arlashchenko, N. I.; Korneev, D. Iu; Sagalovich, S. V.; Sarantseva, A. V.; Toscano, W.; Kozlovskaia, I. B.

2003-01-01

The ability of 4 cosmonauts to voluntarily control their physiological parameters during the standing test was evaluated following a series of the adaptive feedback (AF) training sessions. Vegetative status of the cosmonauts during voluntary "relaxation" and "straining" was different when compared with its indices determined before these sessions. In addition, there was a considerable individual variability in the intensity and direction of the AF effects, and the range of parameters responding to AF. It was GCR which was the easiest one for the AF control.

The influence of environmental variables on platelet concentration in horse platelet-rich plasma.

PubMed

Rinnovati, Riccardo; Romagnoli, Noemi; Gentilini, Fabio; Lambertini, Carlotta; Spadari, Alessandro

2016-07-04

Platelet-rich plasma (PRP) commonly refers to blood products which contain a higher platelet (PLT) concentration as compared to normal plasma. Autologous PRP has been shown to be safe and effective in promoting the natural processes of soft tissue healing or reconstruction in humans and horses. Variability in PLT concentration has been observed in practice between PRP preparations from different patients or from the same individual under different conditions. A change in PLT concentration could modify PRP efficacy in routine applications. The aim of this study was to test the influence of environmental, individual and agonistic variables on the PLT concentration of PRP in horses. Six healthy Standardbred mares were exposed to six different variables with a one-week washout period between variables, and PRP was subsequently obtained from each horse. The variables were time of withdrawal during the day (morning/evening), hydration status (overhydration/dehydration) treatment with anti-inflammatory drugs and training periods on a treadmill. The platelet concentration was significantly higher in horses treated with a non-steroidal anti-inflammatory drug (P = 0.03). The leukocyte concentration increased 2-9 fold with respect to whole blood in the PRP which was obtained after exposure to all the variable considered. Environmental variation in platelet concentration should be taken into consideration during PRP preparation.

Prioritizing Wetlands for Waterbirds in a Boom and Bust System: Waterbird Refugia and Breeding in the Murray-Darling Basin.

PubMed

Bino, Gilad; Kingsford, Richard T; Porter, John

2015-01-01

Dryland rivers have considerable flow variability, producing complex ecosystems, processes, and communities of organisms that vary over space and time. They are also among the more vulnerable of the world's ecosystems. A key strategy for conservation of dryland rivers is identifying and maintaining key sites for biodiversity conservation, particularly protecting the quantity and quality of flow and flooding regimes. Extreme variability considerably challenges freshwater conservation planning. We systematically prioritised wetlands for waterbirds (simultaneously for 52 species), across about 13.5% of the Murray-Darling Basin (1,061,469 km2), using a 30-year record of systematic aerial surveys of waterbird populations. Nine key wetlands in this area, primarily lakes, floodplains, and swamps, consistently contributed to a representation target (80%) of total abundances of all 52 waterbird species. The long temporal span of our data included dramatic availability (i.e., booms) and scarcity (i.e., busts) of water, providing a unique opportunity to test prioritisation at extremes of variation. These extremes represented periods when waterbirds were breeding or concentrating on refugia, varying wetland prioritisation. In dry years, important wetlands for waterbirds were riverine and lacustrine (12 wetlands) but this changed in wet years to lacustrine and palustrine (8 wetlands). Such variation in ecosystem condition substantially changes the relative importance of individual wetlands for waterbirds during boom and bust phases. Incorporating this variability is necessary for effective conservation of Murray-Darling Basin waterbirds, with considerable generality for other similarly variable systems around the world.

Team-level predictors of innovation at work: a comprehensive meta-analysis spanning three decades of research.

PubMed

Hülsheger, Ute R; Anderson, Neil; Salgado, Jesus F

2009-09-01

This article presents a meta-analysis of team-level antecedents of creativity and innovation in the workplace. Using a general input-process-output model, the authors examined 15 team-level variables researched in primary studies published over the last 30 years and their relation to creativity and innovation. An exhaustive search of the international innovation literature resulted in a final sample (k) of 104 independent studies. Results revealed that team process variables of support for innovation, vision, task orientation, and external communication displayed the strongest relationships with creativity and innovation (rhos between 0.4 and 0.5). Input variables (i.e., team composition and structure) showed weaker effect sizes. Moderator analyses confirmed that relationships differ substantially depending on measurement method (self-ratings vs. independent ratings of innovation) and measurement level (individual vs. team innovation). Team variables displayed considerably stronger relationships with self-report measures of innovation compared with independent ratings and objective criteria. Team process variables were more strongly related to creativity and innovation measured at the team than the individual level. Implications for future research and pragmatic ramifications for organizational practice are discussed in conclusion.

Individual differences in the day-to-day variability of pain, fatigue, and well-being in patients with rheumatic disease: Associations with psychological variables

PubMed Central

Schneider, Stefan; Junghaenel, Doerte U.; Keefe, Francis J.; Schwartz, Joseph E.; Stone, Arthur A.; Broderick, Joan E.

2012-01-01

This paper examines day-to-day variability in rheumatology patients' ratings of pain and related quality-of-life variables as well as predictors of that variability. Data from two studies were used. The hypothesis was that greater psychological distress (i.e., depression and anxiety) and poorer coping appraisals (i.e., higher pain catastrophizing and lower self-efficacy) are associated with more variability. Electronic daily diary ratings were collected from 106 patients from a community rheumatology practice across 28 days (Study 1), and from 194 osteoarthritis patients across 7 days (Study 2). In multilevel modeling analyses, substantial day-to-day variability was evident for all variables in both studies, andindividual patients differed considerably and somewhat reliably in the magnitude of their variability. Higher levels of depression significantly predicted greater variability in pain, as well as in happiness and frustration (Study 1). Lower self-efficacy was associated with more variability in patients' daily satisfaction with accomplishments and in the quality of their day (Study 2). Greater pain catastrophizing and higher depression predicted more variability in interference with social relationships (Study 2). Anxiety was not significantly associated with day-to-day variability. The results of these studies suggest that individual differences in the magnitude of symptom fluctuation may play a vital role in understanding patients' adjustment to pain. Future research will be needed to examine the clinical utility of measuring variability in patients' pain and well being, and to understand whether reducing variability may be an important treatment target. PMID:22349917

A 576-year Weber River streamflow reconstruction from tree rings for water resource risk assessment in the Wasatch Front, Utah

Treesearch

Matthew F. Bekker; R. Justin DeRose; Brendan M. Buckley; Roger K. Kjelgren; Nathan S. Gill

2014-01-01

We present a 576-year tree-ring-based reconstruction of streamflow for northern Utah's Weber River that exhibits considerable interannual and decadal-scale variability. While the 20th Century instrumental period includes several extreme individual dry years, it was the century with the fewest such years of the entire reconstruction. Extended droughts were more...

Spatial and temporal variability of microgeographic genetic structure in white-tailed deer

USGS Publications Warehouse

Scribner, Kim T.; Smith, Michael H.; Chesser, Ronald K.

1997-01-01

Techniques are described that define contiguous genetic subpopulations of white-tailed deer (Odocoileus virginianus) based on the spatial dispersion of 4,749 individuals that possessed discrete character values (alleles or genotypes) during each of 6 years (1974-1979). White-tailed deer were not uniformly distributed in space, but exhibited considerable spatial genetic structuring. Significant non-random clusters of individuals were documented during each year based on specific alleles and genotypes at the Sdh locus. Considerable temporal variation was observed in the position and genetic composition of specific clusters, which reflected changes in allele frequency in small geographic areas. The position of clusters did not consistently correspond with traditional management boundaries based on major discontinuities in habitat (swamp versus upland) and hunt compartments that were defined by roads and streams. Spatio-temporal stability of observed genetic contiguous clusters was interpreted relative to method and intensity of harvest, movements, and breeding ecology.

Tobacco smoking and depression: time to move on to a new research paradigm in medicine?

PubMed

de Jonge, Peter; Bos, Elisabeth Henriette

2013-05-24

A recent paper published in BMC Cardiovascular Disorders reported on a study into whether tobacco smoking may serve as a risk factor for depression in patients with heart disease. In the current paper, we discuss several limitations of that study, of which many apply not just to the study itself but to the nomothetic research design that was used. Particularly when bidirectionality between variables is expected, fluctuation in variables over time takes place, and/or inter-individual differences are considerable, a nomothetic research approach does not seem appropriate, and may lead to false conclusions. As an alternative, we describe an idiographic approach in which individuals are followed up over time using many repeated measurements, and from which individual models are estimated. Such intensive time-series studies are not common in medicine, but are well described in the fields of econometrics and meteorology. Combining idiographic research designs with more traditional nomothetic designs may lead to research findings that are not only useful for society but also valid in individuals. See related research article here http://www.biomedcentral.com/1471-2261/13/35.

Tobacco smoking and depression: time to move on to a new research paradigm in medicine?

PubMed Central

2013-01-01

A recent paper published in BMC Cardiovascular Disorders reported on a study into whether tobacco smoking may serve as a risk factor for depression in patients with heart disease. In the current paper, we discuss several limitations of that study, of which many apply not just to the study itself but to the nomothetic research design that was used. Particularly when bidirectionality between variables is expected, fluctuation in variables over time takes place, and/or inter-individual differences are considerable, a nomothetic research approach does not seem appropriate, and may lead to false conclusions. As an alternative, we describe an idiographic approach in which individuals are followed up over time using many repeated measurements, and from which individual models are estimated. Such intensive time-series studies are not common in medicine, but are well described in the fields of econometrics and meteorology. Combining idiographic research designs with more traditional nomothetic designs may lead to research findings that are not only useful for society but also valid in individuals. See related research article here http://www.biomedcentral.com/1471-2261/13/35. PMID:23705867

An Analysis of Individual Differences in Recognizing Monosyllabic Words Under the Speech Intelligibility Index Framework

PubMed Central

Shen, Yi; Kern, Allison B.

2018-01-01

Individual differences in the recognition of monosyllabic words, either in isolation (NU6 test) or in sentence context (SPIN test), were investigated under the theoretical framework of the speech intelligibility index (SII). An adaptive psychophysical procedure, namely the quick-band-importance-function procedure, was developed to enable the fitting of the SII model to individual listeners. Using this procedure, the band importance function (i.e., the relative weights of speech information across the spectrum) and the link function relating the SII to recognition scores can be simultaneously estimated while requiring only 200 to 300 trials of testing. Octave-frequency band importance functions and link functions were estimated separately for NU6 and SPIN materials from 30 normal-hearing listeners who were naïve to speech recognition experiments. For each type of speech material, considerable individual differences in the spectral weights were observed in some but not all frequency regions. At frequencies where the greatest intersubject variability was found, the spectral weights were correlated between the two speech materials, suggesting that the variability in spectral weights reflected listener-originated factors. PMID:29532711

Sampling Capacity Underlies Individual Differences in Human Associative Learning

PubMed Central

2014-01-01

Though much work has studied how external factors, such as stimulus properties, influence generalization of associative strength, there has been limited exploration of the influence that internal dispositions may contribute to stimulus processing. Here we report 2 studies using a modified negative patterning discrimination to test the relationship between global processing and generalization. Global processing was associated with stronger negative patterning discrimination, indicative of limited generalization between distinct stimulus compounds and their constituent elements. In Experiment 2, participants pretrained to adopt global processing similarly showed strong negative patterning discrimination. These results demonstrate considerable individual difference in capacity to engage in negative patterning discrimination and suggest that the tendency toward global processing may be one factor explaining this variability. The need for models of learning to account for this variability in learning is discussed. PMID:24446699

Profiling the repertoire of phenotypes influenced by environmental cues that occur during asexual reproduction.

PubMed

Dombrovsky, Aviv; Arthaud, Laury; Ledger, Terence N; Tares, Sophie; Robichon, Alain

2009-11-01

The aphid Acyrthosiphon pisum population is composed of different morphs, such as winged and wingless parthenogens, males, and sexual females. The combined effect of reduced photoperiodicity and cold in fall triggers the apparition of sexual morphs. In contrast they reproduce asexually in spring and summer. In our current study, we provide evidence that clonal individuals display phenotypic variability within asexual morph categories. We describe that clones sharing the same morphological features, which arose from the same founder mother, constitute a repertoire of variants with distinct behavioral and physiological traits. Our results suggest that the prevailing environmental conditions influence the recruitment of adaptive phenotypes from a cohort of clonal individuals exhibiting considerable molecular diversity. However, we observed that the variability might be reduced or enhanced by external factors, but is never abolished in accordance with a model of stochastically produced phenotypes. This overall mechanism allows the renewal of colonies from a few adapted individuals that survive drastic episodic changes in a fluctuating environment.

Profiling the repertoire of phenotypes influenced by environmental cues that occur during asexual reproduction

PubMed Central

Dombrovsky, Aviv; Arthaud, Laury; Ledger, Terence N.; Tares, Sophie; Robichon, Alain

2009-01-01

The aphid Acyrthosiphon pisum population is composed of different morphs, such as winged and wingless parthenogens, males, and sexual females. The combined effect of reduced photoperiodicity and cold in fall triggers the apparition of sexual morphs. In contrast they reproduce asexually in spring and summer. In our current study, we provide evidence that clonal individuals display phenotypic variability within asexual morph categories. We describe that clones sharing the same morphological features, which arose from the same founder mother, constitute a repertoire of variants with distinct behavioral and physiological traits. Our results suggest that the prevailing environmental conditions influence the recruitment of adaptive phenotypes from a cohort of clonal individuals exhibiting considerable molecular diversity. However, we observed that the variability might be reduced or enhanced by external factors, but is never abolished in accordance with a model of stochastically produced phenotypes. This overall mechanism allows the renewal of colonies from a few adapted individuals that survive drastic episodic changes in a fluctuating environment. PMID:19635846

Does intrinsic light heterogeneity in Ricinus communis L. monospecific thickets drive species' population dynamics?

PubMed

Goyal, Neha; Shah, Kanhaiya; Sharma, Gyan Prakash

2018-06-19

Ricinus communis L. colonizes heterogeneous urban landscapes as monospecific thickets. The ecological understanding on colonization success of R. communis population due to variable light availability is lacking. Therefore, to understand the effect of intrinsic light heterogeneity on species' population dynamics, R. communis populations exposed to variable light availability (low, intermediate, and high) were examined for performance strategies through estimation of key vegetative, eco-physiological, biochemical, and reproductive traits. Considerable variability existed in studied plant traits in response to available light. Individuals inhabiting high-light conditions exhibited high eco-physiological efficiency and reproductive performance that potentially confers population boom. Individuals exposed to low light showed poor performance in terms of eco-physiology and reproduction, which attribute to bust. However, individuals in intermediate light were observed to be indeterminate to light availability, potentially undergoing trait modulations with uncertainty of available light. Heterogeneous light availability potentially drives the boom and bust cycles in R. communis monospecific thickets. Such boom and bust cycles subsequently affect species' dominance, persistence, collapse, and/or resurgence as an aggressive colonizer in contrasting urban environments. The study fosters extensive monitoring of R. communis thickets to probe underlying mechanism(s) affecting expansions and/or collapses of colonizing populations.

The variability in adherence to dietary treatment and quality of weight loss: overweight and obesity.

PubMed

Reig García-Galbis, Manuel; Cortés Castell, Ernesto; Rizo Baeza, Mercedes; Gutiérrez Hervás, Ana

2015-05-01

Observation of weight loss and the maximum time that individualized dietary treatment qualitative and quantitative is shown to be effective. 4625 consultations were conducted with 616 patients over 25 years old, in the nutrition consultation, using the qualitative and quantitative individualized dietary treatment. As a result we controlled the weight loss, the fat and the quality and variability of the loss, monthly according to sex, age and BMI in an urban area of southeastern Spain. A low level of abandonment was proved in men, patients older than 45 years old compared to obese showed a higher degree. The quality of the loss was greater in men under 45 years old, overweight patients, however, more research is needed in this area. Measuring the waist and hips has led to an increasing interest in measuring indicators of body fat. The individualized dietary treatment has been proved to be effective for six months and then a multidisciplinary mode of this treatment is recommended. The use of new ways to assess weight loss is proposed taking into consideration the quality and variability of loss, regardless of the treatment used. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Determinants of 24-hour energy expenditure in man. Methods and results using a respiratory chamber.

PubMed Central

Ravussin, E; Lillioja, S; Anderson, T E; Christin, L; Bogardus, C

1986-01-01

Daily human energy requirements calculated from separate components of energy expenditure are inaccurate and usually in poor agreement with measured energy intakes. Measurement of energy expenditure over periods of 24 h or longer is needed to determine more accurately rates of daily energy expenditure in humans. We provide a detailed description of a human respiratory chamber and methods used to determine rates of energy expenditure over 24-h periods in 177 subjects. The results show that: fat-free mass (FFM) as estimated by densitometry is the best available determinant of 24-h energy expenditures (24EE) and explains 81% of the variance observed between individuals (24EE [kcal/d] = 597 + 26.5 FFM); 24EE in an individual is very reproducible (coefficient of variation = 2.4%); and even when adjusted for differences in FFM, there is still considerable interperson variability of the daily energy expenditure. A large portion of the variability of 24EE among individuals, independent of differences in body size, was due to variability in the degree of spontaneous physical activity, i.e., "fidgeting," which accounted for 100-800 kcal/d in these subjects. Images PMID:3782471

Case-Crossover Analysis of Air Pollution Health Effects: A Systematic Review of Methodology and Application

PubMed Central

Carracedo-Martínez, Eduardo; Taracido, Margarita; Tobias, Aurelio; Saez, Marc; Figueiras, Adolfo

2010-01-01

Background Case-crossover is one of the most used designs for analyzing the health-related effects of air pollution. Nevertheless, no one has reviewed its application and methodology in this context. Objective We conducted a systematic review of case-crossover (CCO) designs used to study the relationship between air pollution and morbidity and mortality, from the standpoint of methodology and application. Data sources and extraction A search was made of the MEDLINE and EMBASE databases. Reports were classified as methodologic or applied. From the latter, the following information was extracted: author, study location, year, type of population (general or patients), dependent variable(s), independent variable(s), type of CCO design, and whether effect modification was analyzed for variables at the individual level. Data synthesis The review covered 105 reports that fulfilled the inclusion criteria. Of these, 24 addressed methodological aspects, and the remainder involved the design’s application. In the methodological reports, the designs that yielded the best results in simulation were symmetric bidirectional CCO and time-stratified CCO. Furthermore, we observed an increase across time in the use of certain CCO designs, mainly symmetric bidirectional and time-stratified CCO. The dependent variables most frequently analyzed were those relating to hospital morbidity; the pollutants most often studied were those linked to particulate matter. Among the CCO-application reports, 13.6% studied effect modification for variables at the individual level. Conclusions The use of CCO designs has undergone considerable growth; the most widely used designs were those that yielded better results in simulation studies: symmetric bidirectional and time-stratified CCO. However, the advantages of CCO as a method of analysis of variables at the individual level are put to little use. PMID:20356818

Team versus individual sport participation as a modifying factor in the development of post-concussion syndrome after first concussion: A pilot study.

PubMed

Jeckell, Aaron S; Brett, Benjamin L; Totten, Douglas J; Solomon, Gary S

2018-01-19

Identification of modifying factors that influence the development of post-concussion syndrome (PCS) following sport-related concussion (SRC) has drawn considerable interest. In this pilot study, we investigate the effect of team vs. individual sport participation on the development of PCS in a sample of 136 high school and college student-athletes. Controlling for several confounding variables, we employed a binary logistic regression and chi-squared test. Results of this pilot study indicate that participation in team versus individual sport is not a significant factor in the development of PCS. The identification of other forms of protective mechanisms is discussed.

Consideration of immediate and future consequences, smoking status, and body mass index.

PubMed

Adams, Jean

2012-03-01

Health-related behaviors often involve immediate costs to achieve long-term benefits. How one considers the future outcomes of present day behaviors (e.g., temporal orientation) may play a role in engagement in healthy behaviors. The Consideration of Future Consequences Scale (CFCS) measures temporal orientation on a unidimensional continuum. Recently, 2 subscales of the CFCS have been reported: immediate (CFC-I) and future (CFC-F) consequences. These support a multidimensional conceptualization of temporal orientation. Confirmatory factor analysis was performed on CFCS data. The associations between 2 health-related variables [smoking and body mass index (BMI)] and each subscale were then explored, controlling for sociodemographic variables. A random sample of 2,000 individuals aged 18 years or over was selected from the edited electoral role for one English city and sent a postal questionnaire, including the CFCS and questions on age, gender, socioeconomic position, and self-reported current smoking status and BMI. Complete data was provided by 800 participants (response rate = 40.0%). The 2-factor model fitted CFCS data better than the 1-factor model. In multiple linear regression, CFC-I was positively associated with BMI, B (95% confidence interval [CI]) = 0.47 (0.06 to 0.88), p = .025; and odds of being a current smoker, odds ratio (95% CI) = 1.28 (1.02 to 1.60), p = .035; CFC-F was not associated with health-related variables. These data support the multidimensional conceptualization of temporal orientation. Consideration of immediate consequences may be a more important determinant of health-related behaviors than consideration of future consequences.

Addressing the inter-individual variation in response to consumption of plant food bioactives: Towards a better understanding of their role in healthy aging and cardiometabolic risk reduction.

PubMed

Manach, Claudine; Milenkovic, Dragan; Van de Wiele, Tom; Rodriguez-Mateos, Ana; de Roos, Baukje; Garcia-Conesa, Maria Teresa; Landberg, Rikard; Gibney, Eileen R; Heinonen, Marina; Tomás-Barberán, Francisco; Morand, Christine

2017-06-01

Bioactive compounds in plant-based foods have health properties that contribute to the prevention of age-related chronic diseases, particularly cardiometabolic disorders. Conclusive proof and understanding of these benefits in humans is essential in order to provide effective dietary recommendations but, so far, the evidence obtained from human intervention trials is limited and contradictory. This is partly due to differences between individuals in the absorption, distribution, metabolism and excretion of bioactive compounds, as well as to heterogeneity in their biological response regarding cardiometabolic health outcomes. Identifying the main factors underlying inter-individual differences, as well as developing new and innovative methodologies to account for such variability constitute an overarching goal to ultimately optimize the beneficial health effects of plant food bioactives for each and every one of us. In this respect, this position paper from the COST Action FA1403-POSITIVe examines the main factors likely to affect the individual responses to consumption of plant food bioactives and presents perspectives for assessment and consideration of inter-individual variability. © 2016 The Authors. Molecular Nutrition & Food Research published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Individualization and the Health Care Mosaic in Assisted Living.

PubMed

Kemp, Candace L; Ball, Mary M; Perkins, Molly M

2018-06-15

Assisted living (AL) is a popular residential long-term care option for frail older adults in the United States. Most residents have multiple comorbidities and considerable health care needs, but little is known about their health care arrangements, particularly over time. Our goal is to understand how health care is managed and experienced in AL by residents and their care network members. This grounded theory analysis focuses on the delivery of health care in AL. Qualitative data were gathered from 28 residents and 114 of their care network members followed over a 2-year period in 4 diverse settings as part of the larger study, "Convoys of Care: Developing Collaborative Care Partnerships in Assisted Living." Findings show that health care in AL involves routine, acute, rehabilitative, and end-of-life care, is provided by residents, formal and informal caregivers, and occurs on- and off-site. Our conceptual model derived from grounded theory analysis, "individualizing health care," reflects the variability found in care arrangements over time and the multiple, multilevel factors we identified related to residents and caregivers (e.g., age, health), care networks (e.g., size, composition), residences (e.g., ownership), and community and regulatory contexts. This variability leads to individualization and a mosaic of health care among AL residents and communities. Our consideration of health care and emphasis on care networks draw attention to the importance of communication and need for collaboration within care networks as key avenues for improving care for this and other frail populations.

How well can body size represent effects of the environment on demographic rates? Disentangling correlated explanatory variables.

PubMed

Brooks, Mollie E; Mugabo, Marianne; Rodgers, Gwendolen M; Benton, Timothy G; Ozgul, Arpat

2016-03-01

Demographic rates are shaped by the interaction of past and current environments that individuals in a population experience. Past environments shape individual states via selection and plasticity, and fitness-related traits (e.g. individual size) are commonly used in demographic analyses to represent the effect of past environments on demographic rates. We quantified how well the size of individuals captures the effects of a population's past and current environments on demographic rates in a well-studied experimental system of soil mites. We decomposed these interrelated sources of variation with a novel method of multiple regression that is useful for understanding nonlinear relationships between responses and multicollinear explanatory variables. We graphically present the results using area-proportional Venn diagrams. Our novel method was developed by combining existing methods and expanding upon them. We showed that the strength of size as a proxy for the past environment varied widely among vital rates. For instance, in this organism with an income breeding life history, the environment had more effect on reproduction than individual size, but with substantial overlap indicating that size encompassed some of the effects of the past environment on fecundity. This demonstrates that the strength of size as a proxy for the past environment can vary widely among life-history processes within a species, and this variation should be taken into consideration in trait-based demographic or individual-based approaches that focus on phenotypic traits as state variables. Furthermore, the strength of a proxy will depend on what state variable(s) and what demographic rate is being examined; that is, different measures of body size (e.g. length, volume, mass, fat stores) will be better or worse proxies for various life-history processes. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Audiometric correlates of the Hearing Handicap Inventory for the elderly.

PubMed

Weinstein, B E; Ventry, I M

1983-11-01

The self-assessment of hearing handicap has received considerable attention in recent years. The Hearing Handicap Inventory for the Elderly (HHIE) is a self-assessment technique designed to quantify the emotional and social effects of self-perceived hearing impairment in the noninstitutionalized elderly. The purpose of the present study was to examine the audiometric correlates of hearing handicap as measured by the HHIE. One hundred elderly subjects received complete audiometric evaluations as well as the HHIE. The results indicated that pure-tone sensitivity in the better ear was most highly correlated with the HHIE (r = .61) and that word recognition accounted for no more than 20% of the variance in HHIE scores. These results are similar to those reported for younger subjects and for other handicap assessment techniques. The results also indicated that there is considerable individual variability in the emotional and social response to hearing impairment, especially in individuals with mild (26-40 dB PTA in better ear) hearing impairment. The variability in response to impairment coupled with the fact that audiometric measures explain less than 50% of the variance in hearing handicap suggest that hearing handicap in the elderly will be measured more appropriately via a self-report format rather than as an inference from audiometric data.

Prioritizing Wetlands for Waterbirds in a Boom and Bust System: Waterbird Refugia and Breeding in the Murray-Darling Basin

PubMed Central

Bino, Gilad; Kingsford, Richard T.; Porter, John

2015-01-01

Dryland rivers have considerable flow variability, producing complex ecosystems, processes, and communities of organisms that vary over space and time. They are also among the more vulnerable of the world’s ecosystems. A key strategy for conservation of dryland rivers is identifying and maintaining key sites for biodiversity conservation, particularly protecting the quantity and quality of flow and flooding regimes. Extreme variability considerably challenges freshwater conservation planning. We systematically prioritised wetlands for waterbirds (simultaneously for 52 species), across about 13.5% of the Murray-Darling Basin (1,061,469 km2), using a 30-year record of systematic aerial surveys of waterbird populations. Nine key wetlands in this area, primarily lakes, floodplains, and swamps, consistently contributed to a representation target (80%) of total abundances of all 52 waterbird species. The long temporal span of our data included dramatic availability (i.e., booms) and scarcity (i.e., busts) of water, providing a unique opportunity to test prioritisation at extremes of variation. These extremes represented periods when waterbirds were breeding or concentrating on refugia, varying wetland prioritisation. In dry years, important wetlands for waterbirds were riverine and lacustrine (12 wetlands) but this changed in wet years to lacustrine and palustrine (8 wetlands). Such variation in ecosystem condition substantially changes the relative importance of individual wetlands for waterbirds during boom and bust phases. Incorporating this variability is necessary for effective conservation of Murray-Darling Basin waterbirds, with considerable generality for other similarly variable systems around the world. PMID:26161652

Auditory Multi-Stability: Idiosyncratic Perceptual Switching Patterns, Executive Functions and Personality Traits

PubMed Central

Farkas, Dávid; Denham, Susan L.; Bendixen, Alexandra; Tóth, Dénes; Kondo, Hirohito M.; Winkler, István

2016-01-01

Multi-stability refers to the phenomenon of perception stochastically switching between possible interpretations of an unchanging stimulus. Despite considerable variability, individuals show stable idiosyncratic patterns of switching between alternative perceptions in the auditory streaming paradigm. We explored correlates of the individual switching patterns with executive functions, personality traits, and creativity. The main dimensions on which individual switching patterns differed from each other were identified using multidimensional scaling. Individuals with high scores on the dimension explaining the largest portion of the inter-individual variance switched more often between the alternative perceptions than those with low scores. They also perceived the most unusual interpretation more often, and experienced all perceptual alternatives with a shorter delay from stimulus onset. The ego-resiliency personality trait, which reflects a tendency for adaptive flexibility and experience seeking, was significantly positively related to this dimension. Taking these results together we suggest that this dimension may reflect the individual’s tendency for exploring the auditory environment. Executive functions were significantly related to some of the variables describing global properties of the switching patterns, such as the average number of switches. Thus individual patterns of perceptual switching in the auditory streaming paradigm are related to some personality traits and executive functions. PMID:27135945

Cultural Variability in the Link Between Environmental Concern and Support for Environmental Action.

PubMed

Eom, Kimin; Kim, Heejung S; Sherman, David K; Ishii, Keiko

2016-10-01

Research on sustainability behaviors has been based on the assumption that increasing personal concerns about the environment will increase proenvironmental action. We tested whether this assumption is more applicable to individualistic cultures than to collectivistic cultures. In Study 1, we compared 47 countries ( N = 57,268) and found that they varied considerably in the degree to which environmental concern predicted support for proenvironmental action. National-level individualism explained the between-nation variability above and beyond the effects of other cultural values and independently of person-level individualism. In Study 2, we compared individualistic and collectivistic nations (United States vs. Japan; N = 251) and found culture-specific predictors of proenvironmental behavior. Environmental concern predicted environmentally friendly consumer choice among European Americans but not Japanese. For Japanese participants, perceived norms about environmental behavior predicted proenvironmental decision making. Facilitating sustainability across nations requires an understanding of how culture determines which psychological factors drive human action.

Modeling and parameterization of horizontally inhomogeneous cloud radiative properties

NASA Technical Reports Server (NTRS)

Welch, R. M.

1995-01-01

One of the fundamental difficulties in modeling cloud fields is the large variability of cloud optical properties (liquid water content, reflectance, emissivity). The stratocumulus and cirrus clouds, under special consideration for FIRE, exhibit spatial variability on scales of 1 km or less. While it is impractical to model individual cloud elements, the research direction is to model a statistical ensembles of cloud elements with mean-cloud properties specified. The major areas of this investigation are: (1) analysis of cloud field properties; (2) intercomparison of cloud radiative model results with satellite observations; (3) radiative parameterization of cloud fields; and (4) development of improved cloud classification algorithms.

Balancing precision and risk: should multiple detection methods be analyzed separately in N-mixture models?

USGS Publications Warehouse

Graves, Tabitha A.; Royle, J. Andrew; Kendall, Katherine C.; Beier, Paul; Stetz, Jeffrey B.; Macleod, Amy C.

2012-01-01

Using multiple detection methods can increase the number, kind, and distribution of individuals sampled, which may increase accuracy and precision and reduce cost of population abundance estimates. However, when variables influencing abundance are of interest, if individuals detected via different methods are influenced by the landscape differently, separate analysis of multiple detection methods may be more appropriate. We evaluated the effects of combining two detection methods on the identification of variables important to local abundance using detections of grizzly bears with hair traps (systematic) and bear rubs (opportunistic). We used hierarchical abundance models (N-mixture models) with separate model components for each detection method. If both methods sample the same population, the use of either data set alone should (1) lead to the selection of the same variables as important and (2) provide similar estimates of relative local abundance. We hypothesized that the inclusion of 2 detection methods versus either method alone should (3) yield more support for variables identified in single method analyses (i.e. fewer variables and models with greater weight), and (4) improve precision of covariate estimates for variables selected in both separate and combined analyses because sample size is larger. As expected, joint analysis of both methods increased precision as well as certainty in variable and model selection. However, the single-method analyses identified different variables and the resulting predicted abundances had different spatial distributions. We recommend comparing single-method and jointly modeled results to identify the presence of individual heterogeneity between detection methods in N-mixture models, along with consideration of detection probabilities, correlations among variables, and tolerance to risk of failing to identify variables important to a subset of the population. The benefits of increased precision should be weighed against those risks. The analysis framework presented here will be useful for other species exhibiting heterogeneity by detection method.

Predictors of alcohol abusers' inconsistent self-reports of their drinking and life events.

PubMed

Toneatto, T; Sobell, L C; Sobell, M B

1992-06-01

Although considerable research supports the veridicality of alcohol abusers' self-reports, all studies find that some proportion of self-reports are inaccurate. Recently, a few studies have examined variables predictive of inaccurate self-reports and found considerable intersubject variability. The present study examined predictors of alcohol abusers' inconsistent reports of life events and drinking using test-retest reliability data from two questionnaires. Results indicated that inconsistent self-reports were associated with the type (i.e., objective versus subjective) and amount (i.e., more drinking involvement at the first interview was associated with greater discrepant reports at the second interview) of information to be recalled. It appears that the nature of the questions asked may be as much or more of a contributing factor to inaccurate self-reports as subject or setting factors, especially for individuals who report high levels of alcohol use, for whom special efforts may be necessary to gather valid self-report data.

USSR Report, Life Sciences Biomedical and Behavioral Sciences

DTIC Science & Technology

1984-06-04

in Regulation of Ideomotor Movements U. G. Goryacheva and S. A. Kapustin- PSIKHOLOGICHESKIY ZHURNAL, No 1, Jan-Feb 84) 77 Perception of Binaural ...with considerable individual variability. The heart rate decreased from 116.6-124.1 beats /min, on days 2-4, to 89.9 beats /min, on day 5, for the...292-8586] PERCEPTION OF BINAURAL TEMPORAL SHIFTS Moscow PSIKHOLOGICHESKIY ZHURNAL in Russian Vol 5, No 1, Jan-Feb 84 (manuscript received 15

Cultural Differences in Opportunity Cost Consideration.

PubMed

Zhang, Ning; Ji, Li-Jun; Li, Ye

2017-01-01

Two studies were conducted to investigate cultural differences in opportunity cost consideration between Chinese and Euro-Canadians. Opportunity cost is defined as the cost of a benefit that must be forgone in order to pursue a better alternative (Becker et al., 1974). In both studies, participants read about hypothetical purchase scenarios, and then decided whether they would buy a certain product. Opportunity cost consideration was measured in two ways: (1) participants' thoughts pertaining to other (nonfocal) products while making decisions; (2) participants' decisions not to buy a focal product (Study 1) or a more expensive product (Study 2). Across both indexes, we found that after controlling for individual difference variables and amount of pocket money, Chinese participants in China considered financial opportunity cost more than Euro-Canadians in Study 1. Similar results were observed in Study 2 when comparing Chinese in Canada with Euro-Canadians However, the cultural effect on opportunity cost consideration was confounded by family income in Study 2. Implications for resource management, limitations of the current research and directions for future research are discussed.

Key External Influences Affecting Consumers’ Decisions Regarding Food

PubMed Central

Martínez-Ruiz, María Pilar; Gómez-Cantó, Carmen María

2016-01-01

Among the numerous internal and external forces that compete for consumers’ attention in the context in which they buy their food, this paper will seek to provide a review of the most important external influences, such as the variables related to food itself. To this end, in addition to the food attributes traditionally identified in fields such as consumer behavior, it will give special consideration to the classification of food values. Although the influence of these variables on consumer decisions depends on the individual, analyzing them will undoubtedly increase understanding of consumers’ decisions. Additionally, identifying and describing these variables will enable subsequent research on how they influence both consumer behavior and other key outcomes for producers, manufacturers, and retailers in the food industry, such as satisfaction, trust, and loyalty. PMID:27803686

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities.

PubMed

Saez, M; Figueiras, A; Ballester, F; Pérez-Hoyos, S; Ocaña, R; Tobías, A

2001-06-01

The objective of this paper is to introduce a different approach, called the ecological-longitudinal, to carrying out pooled analysis in time series ecological studies. Because it gives a larger number of data points and, hence, increases the statistical power of the analysis, this approach, unlike conventional ones, allows the complementation of aspects such as accommodation of random effect models, of lags, of interaction between pollutants and between pollutants and meteorological variables, that are hardly implemented in conventional approaches. The approach is illustrated by providing quantitative estimates of the short-term effects of air pollution on mortality in three Spanish cities, Barcelona, Valencia and Vigo, for the period 1992-1994. Because the dependent variable was a count, a Poisson generalised linear model was first specified. Several modelling issues are worth mentioning. Firstly, because the relations between mortality and explanatory variables were non-linear, cubic splines were used for covariate control, leading to a generalised additive model, GAM. Secondly, the effects of the predictors on the response were allowed to occur with some lag. Thirdly, the residual autocorrelation, because of imperfect control, was controlled for by means of an autoregressive Poisson GAM. Finally, the longitudinal design demanded the consideration of the existence of individual heterogeneity, requiring the consideration of mixed models. The estimates of the relative risks obtained from the individual analyses varied across cities, particularly those associated with sulphur dioxide. The highest relative risks corresponded to black smoke in Valencia. These estimates were higher than those obtained from the ecological-longitudinal analysis. Relative risks estimated from this latter analysis were practically identical across cities, 1.00638 (95% confidence intervals 1.0002, 1.0011) for a black smoke increase of 10 microg/m(3) and 1.00415 (95% CI 1.0001, 1.0007) for a increase of 10 microg/m(3) of sulphur dioxide. Because the statistical power is higher than in the individual analysis more interactions were statistically significant, especially those among air pollutants and meteorological variables. Air pollutant levels were related to mortality in the three cities of the study, Barcelona, Valencia and Vigo. These results were consistent with similar studies in other cities, with other multicentric studies and coherent with both, previous individual, for each city, and multicentric studies for all three cities.

Phenotypic assortment in wild primate networks: implications for the dissemination of information.

PubMed

Carter, Alecia J; Lee, Alexander E G; Marshall, Harry H; Ticó, Miquel Torrents; Cowlishaw, Guy

2015-05-01

Individuals' access to social information can depend on their social network. Homophily-a preference to associate with similar phenotypes-may cause assortment within social networks that could preclude information transfer from individuals who generate information to those who would benefit from acquiring it. Thus, understanding phenotypic assortment may lead to a greater understanding of the factors that could limit the transfer of information between individuals. We tested whether there was assortment in wild baboon (Papio ursinus) networks, using data collected from two troops over 6 years for six phenotypic traits-boldness, age, dominance rank, sex and the propensity to generate/exploit information-using two methods for defining a connection between individuals-time spent in proximity and grooming. Our analysis indicated that assortment was more common in grooming than proximity networks. In general, there was homophily for boldness, age, rank and the propensity to both generate and exploit information, but heterophily for sex. However, there was considerable variability both between troops and years. The patterns of homophily we observed for these phenotypes may impede information transfer between them. However, the inconsistency in the strength of assortment between troops and years suggests that the limitations to information flow may be quite variable.

The ethics of aggregation and hormone replacement therapy.

PubMed

Lyerly, A D; Myers, E R; Faden, R R

2001-01-01

The use of aggregated quality of life estimates in the formation of public policy and practice guidelines raises concerns about the moral relevance of variability in values in preferences for health care. This variability may reflect unique and deeply held beliefs that may be lost when averaged with the preferences of other individuals. Feminist moral theories which argue for attention to context and particularity underline the importance of ascertaining the extent to which differences in preferences for health states reveal information which is morally relevant to clinicians and policymakers. To facilitate these considerations, we present an empirical study of preferences for the timing and occurrence of health states associated with hormone replacement therapy (HRT). Sixteen women between the ages of 45 and 55 were enrolled in this pilot study. Their preferences regarding five health states associated with HRT (menopausal symptoms. side effects of HRT, breast cancer, myocardial infarction, and osteoporosis) were assessed in quantitative terms known as utilities. Two standard methods, the visual analog scale (VAS) and the standard gamble (SG), were used to assess utility and time preference (calculated as a discount rate). The wide variability of responses underlines the importance of tailoring health care to individual women's preferences. Policy guidelines which incorporate utility analysis must recognize the normative limitations of aggregated preferences, and the moral relevance of individual conceptions of health.

The Impact of Individual Differences on E-Learning System Behavioral Intention

NASA Astrophysics Data System (ADS)

Liao, Peiwen; Yu, Chien; Yi, Chincheh

This study investigated the impact of contingent variables on the relationship between four predictors and employees' behavioral intention with e-learning. Seven hundred and twenty-two employees in online training and education were asked to answer questionnaires about their learning styles, perceptions of the quality of the proposed predictors and behavioral intention with e-learning systems. The results of analysis showed that three contingent variables, gender, job title and industry, significantly influenced the perceptions of predictors and employees' behavioral intention with the e-learning system. This study also found a statistically significant moderating effect of two contingent variables, gender, job title and industry, on the relationship between predictors and e-learning system behavioral intention. The results suggest that a serious consideration of contingent variables is crucial for improving e-learning system behavioral intention. The implications of these results for the management of e-learning systems are discussed.

Predicting Use of Nurse Care Coordination by Older Adults With Chronic Conditions.

PubMed

Vanderboom, Catherine E; Holland, Diane E; Mandrekar, Jay; Lohse, Christine M; Witwer, Stephanie G; Hunt, Vicki L

2017-07-01

To be effective, nurse care coordination must be targeted at individuals who will use the service. The purpose of this study was to identify variables that predicted use of care coordination by primary care patients. Data on the potential predictor variables were obtained from patient interviews, the electronic health record, and an administrative database of 178 adults eligible for care coordination. Use of care coordination was obtained from an administrative database. A multivariable logistic regression model was developed using a bootstrap sampling approach. Variables predicting use of care coordination were dependence in both activities of daily living (ADL) and instrumental activities of daily living (IADL; odds ratio [OR] = 5.30, p = .002), independent for ADL but dependent for IADL (OR = 2.68, p = .01), and number of prescription medications (OR = 1.12, p = .002). Consideration of these variables may improve identification of patients to target for care coordination.

Gender roles, sociosexuality, and sexual behavior among US Black women

PubMed Central

Hall, Naomi M.; Pichon, Latrice C.

2014-01-01

This study examined the relationship between gender roles and sociosexuality (an individual difference variable describing attitudes about sexual permissiveness and promiscuity), and their predictive pattern of HIV-related sexual risk behaviors. A geographically diverse sample of 275 adult, heterosexual Black women (mean age = 33.60 years), participated in a self-administered survey. Significant relationships were found between feminine traits and sociosexuality, and between sociosexuality and four of the five risky sexual behavior variables. Neither masculine nor feminine gender roles were related to any risky sexual behavior variables. Sociosexuality emerged as an important correlate that requires further exploration of its relationship to the attitudes and behaviors of Black women, and its potential relationship to HIV risk-related sexual behavior. The need for more attention to psychosocial variables, and consideration of context, cultural norms, and values is discussed as an important undertaking in order to garner an accurate picture of sexual risk behavior. PMID:25614852

Estimating verbal fluency and naming ability from the test of premorbid functioning and demographic variables: Regression equations derived from a regional UK sample.

PubMed

Jenkinson, Toni-Marie; Muncer, Steven; Wheeler, Miranda; Brechin, Don; Evans, Stephen

2018-06-01

Neuropsychological assessment requires accurate estimation of an individual's premorbid cognitive abilities. Oral word reading tests, such as the test of premorbid functioning (TOPF), and demographic variables, such as age, sex, and level of education, provide a reasonable indication of premorbid intelligence, but their ability to predict other related cognitive abilities is less well understood. This study aimed to develop regression equations, based on the TOPF and demographic variables, to predict scores on tests of verbal fluency and naming ability. A sample of 119 healthy adults provided demographic information and were tested using the TOPF, FAS, animal naming test (ANT), and graded naming test (GNT). Multiple regression analyses, using the TOPF and demographics as predictor variables, were used to estimate verbal fluency and naming ability test scores. Change scores and cases of significant impairment were calculated for two clinical samples with diagnosed neurological conditions (TBI and meningioma) using the method in Knight, McMahon, Green, and Skeaff (). Demographic variables provided a significant contribution to the prediction of all verbal fluency and naming ability test scores; however, adding TOPF score to the equation considerably improved prediction beyond that afforded by demographic variables alone. The percentage of variance accounted for by demographic variables and/or TOPF score varied from 19 per cent (FAS), 28 per cent (ANT), and 41 per cent (GNT). Change scores revealed significant differences in performance in the clinical groups, particularity the TBI group. Demographic variables, particularly education level, and scores on the TOPF should be taken into consideration when interpreting performance on tests of verbal fluency and naming ability. © 2017 The British Psychological Society.

Research activities in the field of human factors: Evaluation and prospects

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

Larchier-Boulanger, J.; Grosdeva, T.

1988-01-01

The industrial systems are sociotechnical i.e., conceived, directed, checked, run, and repaired by individuals belonging to structured organizations for either individual or group work. Hence, a better understanding of how their behavior, competences, and know-how is a must. At the DER and ESF department human factors group is given the mission to enlarge, through a pluridisciplinary approach, the knowledge of human factors in complex systems. Human interventions are analyzed both for their positive aspects (competences and know-how to retrieve complex situations) and their negative aspects (human weaknesses). For safety reasons such analyses are mainly directed toward the nuclear plant operators,more » considered individually (intervening of one operator) or as a team (group behavior). The aims of the studies on human factors are various, and such studies justify the research in this field. They make it possible, through a better consideration of the variables specific to individuals, to bring to the enterprise means for: (1) increasing reliability and helping performance, (2) improving the adjustment of work demands to the real environment, and (3) creating a better energy between the individual and his/her enterprise. The variables specific to human factors that keep developing thus the perspectives for research, in this field, are to recenter and redefine the undertaken studies.« less

Intrinsic Functional Connectivity in the Adult Brain and Success in Second-Language Learning.

PubMed

Chai, Xiaoqian J; Berken, Jonathan A; Barbeau, Elise B; Soles, Jennika; Callahan, Megan; Chen, Jen-Kai; Klein, Denise

2016-01-20

There is considerable variability in an individual's ability to acquire a second language (L2) during adulthood. Using resting-state fMRI data acquired before training in English speakers who underwent a 12 week intensive French immersion training course, we investigated whether individual differences in intrinsic resting-state functional connectivity relate to a person's ability to acquire an L2. We focused on two key aspects of language processing--lexical retrieval in spontaneous speech and reading speed--and computed whole-brain functional connectivity from two regions of interest in the language network, namely the left anterior insula/frontal operculum (AI/FO) and the visual word form area (VWFA). Connectivity between the left AI/FO and left posterior superior temporal gyrus (STG) and between the left AI/FO and dorsal anterior cingulate cortex correlated positively with improvement in L2 lexical retrieval in spontaneous speech. Connectivity between the VWFA and left mid-STG correlated positively with improvement in L2 reading speed. These findings are consistent with the different language functions subserved by subcomponents of the language network and suggest that the human capacity to learn an L2 can be predicted by an individual's intrinsic functional connectivity within the language network. Significance statement: There is considerable variability in second-language learning abilities during adulthood. We investigated whether individual differences in intrinsic functional connectivity in the adult brain relate to success in second-language learning, using resting-state functional magnetic resonance imaging in English speakers who underwent a 12 week intensive French immersion training course. We found that pretraining functional connectivity within two different language subnetworks correlated strongly with learning outcome in two different language skills: lexical retrieval in spontaneous speech and reading speed. Our results suggest that the human capacity to learn a second language can be predicted by an individual's intrinsic functional connectivity within the language network. Copyright © 2016 the authors 0270-6474/16/360755-07$15.00/0.

A Study of the Effectiveness of the Army’s National Advertising Expenditures. Volume 3. Appendices.

DTIC Science & Technology

1981-08-31

N W Ayer Incorpor- ated to study the effectiveness of the Army’s national recruitment advertising . N W Ayer’s Marketing Services Department undertook...Army priorities for the quality of the recruit mix required investigating the differential impact of advertising on key market segments. Segmentation... market segment. Three key considerations in specifying the advertising variables are that 𔄃’ *individual media components were analyzed to account for

Microbiome Heterogeneity Characterizing Intestinal Tissue and Inflammatory Bowel Disease Phenotype.

PubMed

Tyler, Andrea D; Kirsch, Richard; Milgrom, Raquel; Stempak, Joanne M; Kabakchiev, Boyko; Silverberg, Mark S

2016-04-01

Inflammatory bowel disease has been associated with differential abundance of numerous organisms when compared to healthy controls (HCs); however, few studies have investigated variability in the microbiome across intestinal locations and how this variability might be related to disease location and phenotype. In this study, we have analyzed the microbiome of a large cohort of individuals recruited at Mount Sinai Hospital in Toronto, Canada. Biopsies were taken from subjects with Crohn's disease, ulcerative colitis, and HC, and also individuals having undergone ileal pouch-anal anastomosis for treatment of ulcerative colitis or familial adenomatous polyposis. Microbial 16S rRNA was sequenced using the Illumina MiSeq platform. We observed a great deal of variability in the microbiome characterizing different sampling locations. Samples from pouch and afferent limb were comparable in microbial composition. When comparing sigmoid and terminal ileum samples, more differences were observed. The greatest number of differentially abundant microbes was observed when comparing either pouch or afferent limb samples to sigmoid or terminal ileum. Despite these differences, we were able to observe modest microbial variability between inflammatory bowel disease phenotypes and HCs, even when controlling for sampling location and additional experimental factors. Most detected associations were observed between HCs and Crohn's disease, with decreases in specific genera in the families Ruminococcaceae and Lachnospiraceae characterizing tissue samples from individuals with Crohn's disease. This study highlights important considerations when analyzing the composition of the microbiome and also provides useful insight into differences in the microbiome characterizing these seemingly related phenotypes.

Isolated populations of a rare alpine plant show high genetic diversity and considerable population differentiation.

PubMed

Aegisdóttir, Hafdís Hanna; Kuss, Patrick; Stöcklin, Jürg

2009-12-01

Gene flow and genetic variability within and among alpine plant populations can be greatly influenced by the steep environmental gradients and heterogeneous topography of alpine landscapes. In this study, the effects are examined of natural isolation of alpine habitats on genetic diversity and geographic structure in populations of C. thyrsoides, a rare and isolated European Alpine monocarpic perennial with limited seed dispersal capacity. Molecular diversity was analysed for 736 individuals from 32 populations in the Swiss Alps and adjacent Jura mountains using five polymorphic microsatellite loci. Pollen flow was estimated using pollen grain-sized fluorescent powder. In addition, individual-based Bayesian approaches were applied to examine population structure. High within-population genetic diversity (H(E) = 0.76) and a relatively low inbreeding coefficient (F(IS) = 0.022) were found. Genetic differentiation among populations measured with a standardized measure was considerable (G'(ST) = 0.53). A significant isolation-by-distance relationship was found (r = 0.62, P < 0.001) and a significant geographic sub-structure, coinciding with proposed postglacial migration patterns. Altitudinal location and size of populations did not influence molecular variation. Direct measures of pollen flow revealed that insect-mediated pollen dispersal was restricted to short distances within a population. The natural isolation of suitable habitats for C. thyrsoides restricts gene flow among the populations as expected for a monocarpic species with very limited seed dispersal capacities. The observed high within-population genetic diversity in this rare monocarpic perennial is best explained by its outcrossing behaviour, long-lived individuals and overlapping generations. Despite the high within-population genetic diversity, the considerable genetic differentiation and the clear western-eastern differentiation in this species merits consideration in future conservation efforts.

Strength Asymmetry and Landing Mechanics at Return to Sport after ACL Reconstruction

PubMed Central

Schmitt, Laura C.; Paterno, Mark V.; Ford, Kevin R.; Myer, Gregory D.; Hewett, Timothy E.

2014-01-01

Purpose Evidence-based quadriceps femoris muscle (QF) strength guidelines for return to sport following anterior cruciate ligament (ACL) reconstruction are lacking. This study investigated the impact of QF strength asymmetry on knee landing biomechanics at the time of return to sport following ACL reconstruction. Methods Seventy-seven individuals (17.4 years) at the time of return to sport following primary ACL reconstruction (ACLR group) and 47 uninjured control individuals (17.0 years) (CTRL group) participated. QF strength was assessed and Quadriceps Index calculated (QI = [involved strength/uninvolved strength]*100%). The ACLR group was sub-divided based on QI: High Quadriceps (HQ, QI≥90%) and Low-Quadriceps (LQ, QI<85%). Knee kinematic and kinetic variables were collected during a drop vertical jump maneuver. Limb symmetry during landing, and discrete variables were compared among the groups with multivariate analysis of variance and linear regression analyses. Results The LQ group demonstrated worse asymmetry in all kinetic and ground reaction force variables compared to the HQ and CTRL groups, including reduced involved limb peak knee external flexion moments (p<.001), reduced involved limb (p=.003) and increased uninvolved limb (p=.005) peak vertical ground reaction forces, and higher uninvolved limb peak loading rates (p<.004). There were no differences in the landing patterns between the HQ and CTRL groups on any variable (p>.05). In the ACLR group, QF strength estimated limb symmetry during landing after controlling for graft type, meniscus injury, knee pain and symptoms. Conclusion At the time of return to sport, individuals post-ACL reconstruction with weaker QF demonstrate altered landing patterns. Conversely, those with nearly symmetrical QF strength demonstrate landing patterns similar to uninjured individuals. Consideration of an objective QF strength measure may aid clinical decision-making to optimize sports participation following ACL reconstruction. PMID:25373481

40 CFR 194.51 - Consideration of protected individual.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Consideration of protected individual... Individual and Ground-Water Protection Requirements § 194.51 Consideration of protected individual. Compliance assessments that analyze compliance with § 191.15 of this chapter shall assume that an individual...

Implementation of Duchenne Muscular Dystrophy Care Considerations.

PubMed

Andrews, Jennifer G; Conway, Kristin; Westfield, Christina; Trout, Christina; Meaney, F John; Mathews, Katherine; Ciafaloni, Emma; Cunniff, Christopher; Fox, Deborah J; Matthews, Dennis; Pandya, Shree

2018-06-20

Duchenne muscular dystrophy (DMD) is an X-linked disorder characterized by progressive muscle weakness and multisystem involvement. Recent advances in management of individuals with DMD have prolonged survival. Lack of standardized care spurred an international collaboration to develop consensus-based care considerations for diagnosis and management. In this study, we evaluate adherence to considerations at selected sites. We collaborated with the Muscular Dystrophy Surveillance, Tracking, and Research Network. Our sample included males with DMD and Becker muscular dystrophy <21 years as of December 31, 2010, with 1 health care encounter on or after January 1, 2012. We collected data from medical records on encounters occurring January 1, 2012, through December 31, 2014. Adherence was determined when frequency of visits or assessments were at or above recommendations for selected care considerations. Our analytic sample included 299 individuals, 7% of whom (20/299) were classified as childhood-onset Becker muscular dystrophy. Adherence for neuromuscular and respiratory clinician visits was 65% for the cohort; neuromuscular assessments and corticosteroid side effect monitoring measures ranged from 16% to 68%. Adherence was 83% for forced vital capacity and ≤58% for other respiratory diagnostics. Cardiologist assessments and echocardiograms were found for at least 84%. Transition planning for education or health care was documented for 31% of eligible males. Medical records data were used to identify areas in which practice aligns with the care considerations. However, there remains inconsistency across domains and insufficiency in critical areas. More research is needed to explain this variability and identify reliable methods to measure outcomes. Copyright © 2018 by the American Academy of Pediatrics.

A Cross-Language Study of Acoustic Predictors of Speech Intelligibility in Individuals With Parkinson's Disease

PubMed Central

Choi, Yaelin

2017-01-01

Purpose The present study aimed to compare acoustic models of speech intelligibility in individuals with the same disease (Parkinson's disease [PD]) and presumably similar underlying neuropathologies but with different native languages (American English [AE] and Korean). Method A total of 48 speakers from the 4 speaker groups (AE speakers with PD, Korean speakers with PD, healthy English speakers, and healthy Korean speakers) were asked to read a paragraph in their native languages. Four acoustic variables were analyzed: acoustic vowel space, voice onset time contrast scores, normalized pairwise variability index, and articulation rate. Speech intelligibility scores were obtained from scaled estimates of sentences extracted from the paragraph. Results The findings indicated that the multiple regression models of speech intelligibility were different in Korean and AE, even with the same set of predictor variables and with speakers matched on speech intelligibility across languages. Analysis of the descriptive data for the acoustic variables showed the expected compression of the vowel space in speakers with PD in both languages, lower normalized pairwise variability index scores in Korean compared with AE, and no differences within or across language in articulation rate. Conclusions The results indicate that the basis of an intelligibility deficit in dysarthria is likely to depend on the native language of the speaker and listener. Additional research is required to explore other potential predictor variables, as well as additional language comparisons to pursue cross-linguistic considerations in classification and diagnosis of dysarthria types. PMID:28821018

Effect of baseline plasma fatty acids on eicosapentaenoic acid levels in individuals supplemented with alpha-linolenic acid.

PubMed

DeFilippis, Andrew P; Harper, Charles R; Cotsonis, George A; Jacobson, Terry A

2009-01-01

We previously reported a >50% increase in mean plasma eicosapentaenoic acid levels in a general medicine clinic population after supplementation with alpha-linolenic acid. In the current analysis, we evaluate the variability of changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid and evaluated the impact of baseline plasma fatty acids levels on changes in eicosapentaenoic acid levels in these individuals. Changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid ranged from a 55% decrease to a 967% increase. Baseline plasma fatty acids had no statistically significant effect on changes in eicosapentaenoic levels acid after alpha-linolenic acid supplementation. Changes in eicosapentaenoic acid levels varied considerably in a general internal medicine clinic population supplemented with alpha-linolenic acid. Factors that may impact changes in plasma eicosapentaenoic acid levels after alpha-linolenic acid supplementation warrant further study.

VARIABILITY OF VISUAL FIELD MEASUREMENTS IS CORRELATED WITH THE GRADIENT OF VISUAL SENSITIVITY

PubMed Central

Wyatt, Harry J.; Dul, Mitchell W.; Swanson, William H.

2007-01-01

Conventional static automated perimetry provides important clinical information, but its utility is limited by considerable test-retest variability. Fixational eye movements during testing could contribute to variability. To assess this possibility, it is important to know how much sensitivity change would be caused by a given eye movement. To investigate this, we have evaluated the gradient, the rate at which sensitivity changes with location. We tested one eye each, twice within 3 weeks, of 29 patients with glaucoma, 17 young normal subjects and 13 older normal subjects. The 10-2 test pattern with the SITA Standard algorithm was used to assess sensitivity at locations with 2° spacing. Variability and gradient were calculated at individual test locations. Matrix correlations were determined between variability and gradient, and were substantial for the patients with glaucoma. The results were consistent with a substantial contribution to test-retest variability from small fixational eye movements interacting with visual field gradient. Successful characterization of the gradient of sensitivity appears to require sampling at relatively close spacing, as in the 10-2 test pattern. PMID:17320924

Variability of visual field measurements is correlated with the gradient of visual sensitivity.

PubMed

Wyatt, Harry J; Dul, Mitchell W; Swanson, William H

2007-03-01

Conventional static automated perimetry provides important clinical information, but its utility is limited by considerable test-retest variability. Fixational eye movements during testing could contribute to variability. To assess this possibility, it is important to know how much sensitivity change would be caused by a given eye movement. To investigate this, we have evaluated the gradient, the rate at which sensitivity changes with location. We tested one eye each, twice within 3 weeks, of 29 patients with glaucoma, 17 young normal subjects and 13 older normal subjects. The 10-2 test pattern with the SITA Standard algorithm was used to assess sensitivity at locations with 2 degrees spacing. Variability and gradient were calculated at individual test locations. Matrix correlations were determined between variability and gradient, and were substantial for the patients with glaucoma. The results were consistent with a substantial contribution to test-retest variability from small fixational eye movements interacting with visual field gradient. Successful characterization of the gradient of sensitivity appears to require sampling at relatively close spacing, as in the 10-2 test pattern.

Subjective response as a consideration in the pharmacogenetics of alcoholism treatment.

PubMed

Roche, Daniel Jo; Ray, Lara A

2015-01-01

Currently available pharmacological treatments for alcoholism have modest efficacy and high individual variability in treatment outcomes, both of which have been partially attributed to genetic factors. One path to reducing the variability and improving the efficacy associated with these pharmacotherapies may be to identify overlapping genetic contributions to individual differences in both subjective responses to alcohol and alcoholism pharmacotherapy outcomes. As acute subjective response to alcohol is highly predictive of future alcohol related problems, identifying such shared genetic mechanisms may inform the development of personalized treatments that can effectively target converging pathophysiological mechanisms that convey risk for alcoholism. The focus of this review is to revisit the association between subjective response to alcohol and the etiology of alcoholism while also describing genetic contributions to this relationship, discuss potential pharmacogenetic approaches to target subjective response to alcohol in order to improve the treatment of alcoholism and examine conceptual and methodological issues associated with these topics, and outline future approaches to overcome these challenges.

Emotional Understanding in School-Aged Children with Fetal Alcohol Spectrum Disorders: A Promising Target for Intervention

PubMed Central

Petrenko, Christie L. M.; Pandolfino, Mary E.; Quamma, Julie; Olson, Heather Carmichael

2017-01-01

Background Children with fetal alcohol spectrum disorders (FASD) are at high risk for secondary conditions, including mental health difficulties. Data on both children with typical development and other clinical conditions suggest that limited emotional understanding (EU) raises risk for psychopathology, but little is known about EU in FASD. Objective Determine if EU is a reasonable treatment target for children with FASD. Methods 56 children (6–13 years) with FASD completed the Kusche Affective Interview-Revised, a verbal interview measure of EU. Results Children showed striking delays in EU (2–5 years delay) relative to published normative data, despite mean IQ (IQ=94.56) within normal limits. Individual variability was considerable even after accounting for age and verbal IQ. Conclusions Despite variability in individual differences, treatments targeting EU may benefit children with FASD as components within a comprehensive, tailored intervention focused on child self-regulation and caregiver behavior management. PMID:28594481

Cultural and cognitive considerations in the prevention of American Indian adolescent suicide.

PubMed

LaFromboise, T D; Bigfoot, D S

1988-06-01

A description of cultural considerations associated with American Indian adolescent coping is presented within a transactional, cognitive-phenomenological framework. Select cultural values and cultural beliefs of American Indians associated with death are discussed in terms of person variables and situational demand characteristics that interplay in the transactional coping process. Three situational demand characteristics (ambiguity of identity, frequency of loss, and pervasiveness of hardships) are then presented to illustrate the reciprocal relationship between environmental contingencies and American Indian individual and community efforts at coping. The dynamic interdependence between person and environmental variables is emphasized and considered essential for inclusion in the design of interventions to prevent suicide. Existing intervention efforts with American Indian adolescent suicide attempters are reviewed and a school-wide cognitive behavioural approach based on the transactional model of coping with suicide is described. It is suggested that on-going cognitive restructuring, social skills training, and peer counselling training activities be culturally adapted and integrated into relevant areas of the school curricula in order that coping be enhanced and suicide ameliorated.

40 CFR 194.51 - Consideration of protected individual.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Consideration of protected individual. 194.51 Section 194.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION... Individual and Ground-Water Protection Requirements § 194.51 Consideration of protected individual...

40 CFR 194.51 - Consideration of protected individual.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Consideration of protected individual. 194.51 Section 194.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION... Individual and Ground-Water Protection Requirements § 194.51 Consideration of protected individual...

40 CFR 194.51 - Consideration of protected individual.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Consideration of protected individual. 194.51 Section 194.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION... Individual and Ground-Water Protection Requirements § 194.51 Consideration of protected individual...

40 CFR 194.51 - Consideration of protected individual.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Consideration of protected individual. 194.51 Section 194.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION... Individual and Ground-Water Protection Requirements § 194.51 Consideration of protected individual...

RELIABILITY CONCERNS IN THE REPEATED COMPUTERIZED ASSESSMENT OF ATTENTION IN CHILDREN

PubMed Central

Zabel, T. Andrew; von Thomsen, Christian; Cole, Carolyn; Martin, Rebecca; Mahone, E. Mark

2010-01-01

Assessment of attentional processes via computerized assessment is frequently used to quantify intra-individual cognitive improvement or decline in response to treatment. However, assessment of intra-individual change is highly dependent on sufficient test reliability. We examined the test–retest reliability of selected variables from one popular computerized continuous performance test (CPT)—i.e., the Conners’ CPT – Second Edition (CPT-II). Participants were 39 healthy children (20 girls) ages 6–18 without intellectual impairment (mean PPVT-III SS = 102.6), LD, or psychiatric disorders (DICA-IV). Test–retest reliability over the 3–8 month interval (mean = 6 months) was acceptable (Intraclass Correlations [ICC] = .82 to .92) on comparison measures (Beery Test of Visual Perception, WISC-IV Block Design, PPVT-III). In contrast, test–retest reliability was only modest for CPT-II raw scores (ICCs ranging from .62 to .82) and T-scores (ICCs ranging from .33 to .65) for variables of interest (Omissions, Commissions, Variability, Hit Reaction Time, and Attentiveness). Using test–retest reliability information published in the CPT-II manual, 90% confidence intervals based on reliable change index (RCI) methodology were constructed to examine the significance of test–retest difference/change scores. Of the participants in this sample of typically developing youth, 30% generated intra-individual changes in T-scores on the Omissions and Attentiveness variables that exceeded the 90% confidence intervals and qualified as “statistically rare” changes in score. These results suggest a considerable degree of normal variability in CPT-II test scores over extended test–retest intervals, and suggest a need for caution when interpreting test score changes in neurologically unstable clinical populations. PMID:19452302

To pair or not to pair: Sources of social variability with white-faced saki monkeys (Pithecia pithecia) as a case study.

PubMed

Thompson, Cynthia L

2016-05-01

Intraspecific variability in social systems is gaining increased recognition in primatology. Many primate species display variability in pair-living social organizations through incorporating extra adults into the group. While numerous models exist to explain primate pair-living, our tools to assess how and why variation in this trait occurs are currently limited. Here I outline an approach which: (i) utilizes conceptual models to identify the selective forces driving pair-living; (ii) outlines novel possible causes for variability in social organization; and (iii) conducts a holistic species-level analysis of social behavior to determine the factors contributing to variation in pair-living. A case study on white-faced sakis (Pithecia pithecia) is used to exemplify this approach. This species lives in either male-female pairs or groups incorporating "extra" adult males and/or females. Various conceptual models of pair-living suggest that high same-sex aggression toward extra-group individuals is a key component of the white-faced saki social system. Variable pair-living in white-faced sakis likely represents alternative strategies to achieve competency in this competition, in which animals experience conflicting selection pressures between achieving successful group defense and maintaining sole reproductive access to mates. Additionally, independent decisions by individuals may generate social variation by preventing other animals from adopting a social organization that maximizes fitness. White-faced saki inter-individual relationships and demographic patterns also lend conciliatory support to this conclusion. By utilizing both model-level and species-level approaches, with a consideration for potential sources of variation, researchers can gain insight into the factors generating variation in pair-living social organizations. © 2014 The Authors. American Journal of Primatology published by Wiley Periodicals, Inc.

Flight Investigation of the Cooling Characteristics of a Two-row Radial Engine Installation III : Engine Temperature Distribution

NASA Technical Reports Server (NTRS)

Rennak, Robert M; Messing, Wesley E; Morgan, James E

1946-01-01

The temperature distribution of a two-row radial engine in a twin-engine airplane has been investigated in a series of flight tests. The test engine was operated over a wide range of conditions at density altitudes of 5000 and 20,000 feet; quantitative results are presented showing the effects of flight and engine variables upon average engine temperature and over-all temperature spread. Discussions of the effect of the variables on the shape of the temperature patterns and on the temperature distribution of individual cylinders are also included. The results indicate that, for the tests conducted, the temperature distribution patterns were chiefly determined by the fuel-air ratio and cooling-air distributions. It was possible to calculate individual cylinder temperature, on the assumption of equal power distribution among cylinders, to within an average of plus or minus 14 degrees F. of the actual temperature. A considerable change occurred in either the spread or the thrust axis, the average engine fuel-air ratio, the engine speed, the power, or the blower ratio. Smaller effects on the temperature pattern were noticed with a change in cowl-flap opening and altitude. In most of the tests, a change in conditions affected the temperature of the barrels less than that of the heads. The variation of flight and engine variables had a negligible effect on the temperature distributions of the individual cylinders. (author)

Conservation physiology for applied management of marine fish: an overview with perspectives on the role and value of telemetry

PubMed Central

Metcalfe, J. D.; Le Quesne, W. J. F.; Cheung, W. W. L.; Righton, D. A.

2012-01-01

Physiological studies focus on the responses of cells, tissues and individuals to stressors, usually in laboratory situations. Conservation and management, on the other hand, focus on populations. The field of conservation physiology addresses the question of how abiotic drivers of physiological responses at the level of the individual alter requirements for successful conservation and management of populations. To achieve this, impacts of physiological effects at the individual level need to be scaled to impacts on population dynamics, which requires consideration of ecology. Successfully realizing the potential of conservation physiology requires interdisciplinary studies incorporating physiology and ecology, and requires that a constructive dialogue develops between these traditionally disparate fields. To encourage this dialogue, we consider the increasingly explicit incorporation of physiology into ecological models applied to marine fish conservation and management. Conservation physiology is further challenged as the physiology of an individual revealed under laboratory conditions is unlikely to reflect realized responses to the complex variable stressors to which it is exposed in the wild. Telemetry technology offers the capability to record an animal's behaviour while simultaneously recording environmental variables to which it is exposed. We consider how the emerging insights from telemetry can strengthen the incorporation of physiology into ecology. PMID:22566680

Long-Term Use and Perceived Benefits of Goal-Oriented Attentional Self-Regulation Training in Chronic Brain Injury.

PubMed

Loya, Fred; Novakovic-Agopian, Tatjana; Binder, Deborah; Rossi, Annemarie; Rome, Scott; Murphy, Michelle; Chen, Anthony J-W

2017-01-01

Primary Objective. To investigate the long-term use and perceived benefit(s) of strategies included in Goal-Oriented Attentional Self-Regulation (GOALS) training (Novakovic-Agopian et al., 2011) by individuals with acquired brain injury (ABI) and chronic executive dysfunction. Research Design. Longitudinal follow-up of training. Methods and Procedures. Sixteen participants with chronic ABI participated in structured telephone interviews 20 months (range 11 to 31 months) following completion of GOALS training. Participants responded to questions regarding the range of strategies they continued to utilize, perceived benefit(s) of strategy use, situations in which strategy use was found helpful, and functional changes attributed to training. Results. Nearly all participants (94%) reported continued use of at least one trained strategy in their daily lives, with 75% of participants also reporting improved functioning resulting from training. However, there was considerable variability with respect to the specific strategies individuals found helpful as well as the perceived impact of training on overall functioning. Conclusions. GOALS training shows promising long-term benefits for individuals in the chronic phase of brain injury. Identifying individual- and injury-level factors that account for variability in continued strategy use and the perceived long-term benefits of training will help with ongoing intervention development.

Long-Term Use and Perceived Benefits of Goal-Oriented Attentional Self-Regulation Training in Chronic Brain Injury

PubMed Central

Novakovic-Agopian, Tatjana; Binder, Deborah; Rossi, Annemarie; Rome, Scott; Murphy, Michelle; Chen, Anthony J.-W.

2017-01-01

Primary Objective. To investigate the long-term use and perceived benefit(s) of strategies included in Goal-Oriented Attentional Self-Regulation (GOALS) training (Novakovic-Agopian et al., 2011) by individuals with acquired brain injury (ABI) and chronic executive dysfunction. Research Design. Longitudinal follow-up of training. Methods and Procedures. Sixteen participants with chronic ABI participated in structured telephone interviews 20 months (range 11 to 31 months) following completion of GOALS training. Participants responded to questions regarding the range of strategies they continued to utilize, perceived benefit(s) of strategy use, situations in which strategy use was found helpful, and functional changes attributed to training. Results. Nearly all participants (94%) reported continued use of at least one trained strategy in their daily lives, with 75% of participants also reporting improved functioning resulting from training. However, there was considerable variability with respect to the specific strategies individuals found helpful as well as the perceived impact of training on overall functioning. Conclusions. GOALS training shows promising long-term benefits for individuals in the chronic phase of brain injury. Identifying individual- and injury-level factors that account for variability in continued strategy use and the perceived long-term benefits of training will help with ongoing intervention development. PMID:28265472

Cultural Differences in Opportunity Cost Consideration

PubMed Central

Zhang, Ning; Ji, Li-Jun; Li, Ye

2017-01-01

Two studies were conducted to investigate cultural differences in opportunity cost consideration between Chinese and Euro-Canadians. Opportunity cost is defined as the cost of a benefit that must be forgone in order to pursue a better alternative (Becker et al., 1974). In both studies, participants read about hypothetical purchase scenarios, and then decided whether they would buy a certain product. Opportunity cost consideration was measured in two ways: (1) participants' thoughts pertaining to other (nonfocal) products while making decisions; (2) participants' decisions not to buy a focal product (Study 1) or a more expensive product (Study 2). Across both indexes, we found that after controlling for individual difference variables and amount of pocket money, Chinese participants in China considered financial opportunity cost more than Euro-Canadians in Study 1. Similar results were observed in Study 2 when comparing Chinese in Canada with Euro-Canadians However, the cultural effect on opportunity cost consideration was confounded by family income in Study 2. Implications for resource management, limitations of the current research and directions for future research are discussed. PMID:28184202

Simple and multiple linear regression: sample size considerations.

PubMed

Hanley, James A

2016-11-01

The suggested "two subjects per variable" (2SPV) rule of thumb in the Austin and Steyerberg article is a chance to bring out some long-established and quite intuitive sample size considerations for both simple and multiple linear regression. This article distinguishes two of the major uses of regression models that imply very different sample size considerations, neither served well by the 2SPV rule. The first is etiological research, which contrasts mean Y levels at differing "exposure" (X) values and thus tends to focus on a single regression coefficient, possibly adjusted for confounders. The second research genre guides clinical practice. It addresses Y levels for individuals with different covariate patterns or "profiles." It focuses on the profile-specific (mean) Y levels themselves, estimating them via linear compounds of regression coefficients and covariates. By drawing on long-established closed-form variance formulae that lie beneath the standard errors in multiple regression, and by rearranging them for heuristic purposes, one arrives at quite intuitive sample size considerations for both research genres. Copyright © 2016 Elsevier Inc. All rights reserved.

The variable effects of stress on alcohol use from adolescence to early adulthood.

PubMed

Aseltine, R H; Gore, S L

2000-04-01

Despite evidence of a strong association between stress and level of drinking in adolescent populations, the role of stress in accounting for changes in drinking behavior throughout the adolescent years is unclear. This study uses a linear growth curve analysis to examine the determinants of within-individual changes in drinking frequency and binge drinking across five waves of data from a community sample of adolescents who were followed into young adulthood. Predictors of drinking include: stressful life events, parental and peer social support, and parental and peer relationship problems. Findings indicate significant effects of stressful life events and parental support and conflict on both the frequency and intensity of alcohol use. Although age-related changes in these variables coincide with changes in drinking behavior, they do not account for drinking variability over this period. Results from conditional models demonstrate that the impact of the stress is contingent on age, and that the strong associations between drinking and stress evidenced during the high school years weaken considerably as individuals move into their late teens and early twenties. Discussion centers on the complex motivations for and facilitators of drinking as young people mature and change environments over the adolescent years.

Relational-database model for improving quality assurance and process control in a composite manufacturing environment

NASA Astrophysics Data System (ADS)

Gentry, Jeffery D.

2000-05-01

A relational database is a powerful tool for collecting and analyzing the vast amounts of inner-related data associated with the manufacture of composite materials. A relational database contains many individual database tables that store data that are related in some fashion. Manufacturing process variables as well as quality assurance measurements can be collected and stored in database tables indexed according to lot numbers, part type or individual serial numbers. Relationships between manufacturing process and product quality can then be correlated over a wide range of product types and process variations. This paper presents details on how relational databases are used to collect, store, and analyze process variables and quality assurance data associated with the manufacture of advanced composite materials. Important considerations are covered including how the various types of data are organized and how relationships between the data are defined. Employing relational database techniques to establish correlative relationships between process variables and quality assurance measurements is then explored. Finally, the benefits of database techniques such as data warehousing, data mining and web based client/server architectures are discussed in the context of composite material manufacturing.

Rate of dehydration, state of subcellular organisation and nature of cryoprotection are critical factors contributing to the variable success of cryopreservation: studies on recalcitrant zygotic embryos of Haemanthus montanus.

PubMed

Sershen; Berjak, Patricia; Pammenter, N W; Wesley-Smith, James

2012-01-01

Effects of sequential procedures required for cryopreservation of embryos excised from the recalcitrant seeds of Haemanthus montanus were assessed ultrastructurally and in conjunction with respiratory activity and the rate of protein synthesis. Fresh material (water content, 5.05 ± 0.92 g g(-1) dry mass) afforded ultrastructural evidence of considerable metabolic activity, borne out by respiratory rates. Neither exposure to glycerol nor sucrose as penetrating and non-penetrating cryoprotectants, respectively, brought about degradative changes, although increased vacuolation and autophagy accompanied both, while respiratory and protein synthetic activity were not adversely affected. Glycerol-cryoprotected embryos flash dried to water contents >0.4 g g(-1) showed organised ultrastructural features and considerable autophagy consistent with metabolic activity, and although respiratory activity was lower, protein synthesis rate was enhanced relative to fresh material. However, at water contents <0.4 g g(-1), embryo tissue presented a mosaic of cells of variable density and ultrastructural status, but trends in rates of respiration and protein synthesis remained similar. Flash drying after sucrose exposure was accompanied by considerable ultrastructural abnormality particularly at water contents <0.4 g g(-1), lysis of individual and groups of cells and considerable depression of respiration, but not of protein synthesis. Success, assessed as ≥50% axes forming seedlings after cryogen exposure, was obtained only when glycerol-cryoprotected embryos at water contents >0.4 g g(-1)-in which the degree of vacuolation remained moderate-were rapidly cooled. The outcomes of this study are considered particularly in terms of the stresses imposed by prolonged, relatively slow dehydration and ultimate water contents, on embryos showing considerable metabolic activity.

Occam's shadow: levels of analysis in evolutionary ecology - where to next?

USGS Publications Warehouse

Cooch, E.G.; Cam, E.; Link, W.A.

2002-01-01

Evolutionary ecology is the study of evolutionary processes, and the ecological conditions that influence them. A fundamental paradigm underlying the study of evolution is natural selection. Although there are a variety of operational definitions for natural selection in the literature, perhaps the most general one is that which characterizes selection as the process whereby heritable variation in fitness associated with variation in one or more phenotypic traits leads to intergenerational change in the frequency distribution of those traits. The past 20 years have witnessed a marked increase in the precision and reliability of our ability to estimate one or more components of fitness and characterize natural selection in wild populations, owing particularly to significant advances in methods for analysis of data from marked individuals. In this paper, we focus on several issues that we believe are important considerations for the application and development of these methods in the context of addressing questions in evolutionary ecology. First, our traditional approach to estimation often rests upon analysis of aggregates of individuals, which in the wild may reflect increasingly non-random (selected) samples with respect to the trait(s) of interest. In some cases, analysis at the aggregate level, rather than the individual level, may obscure important patterns. While there are a growing number of analytical tools available to estimate parameters at the individual level, and which can cope (to varying degrees) with progressive selection of the sample, the advent of new methods does not reduce the need to consider carefully the appropriate level of analysis in the first place. Estimation should be motivated a priori by strong theoretical analysis. Doing so provides clear guidance, in terms of both (i) assisting in the identification of realistic and meaningful models to include in the candidate model set, and (ii) providing the appropriate context under which the results are interpreted. Second, while it is true that selection (as defined) operates at the level of the individual, the selection gradient is often (if not generally) conditional on the abundance of the population. As such, it may be important to consider estimating transition rates conditional on both the parameter values of the other individuals in the population (or at least their distribution), and population abundance. This will undoubtedly pose a considerable challenge, for both single- and multi-strata applications. It will also require renewed consideration of the estimation of abundance, especially for open populations. Thirdly, selection typically operates on dynamic, individually varying traits. Such estimation may require characterizing fitness in terms of individual plasticity in one or more state variables, constituting analysis of the norms of reaction of individuals to variable environments. This can be quite complex, especially for traits that are under facultative control. Recent work has indicated that the pattern of selection on such traits is conditional on the relative rates of movement among and frequency of spatially heterogeneous habitats, suggesting analyses of evolution of life histories in open populations can be misleading in some cases.

Analysis of cognitive variables and sexual risk behaviors among infected and HIV-uninfected people from Spain.

PubMed

Bermúdez, María de la Paz; Araújo, Ludgleydson Fernandes de; Reyes, Antonio Ortega; Hernández-Quero, José; Teva, Inmaculada

2016-07-01

The wider availability of anti-retroviral treatment has brought about an improvement in the immunological situation of human immunodeficiency virus (HIV)-positive individuals, which in turn has led to significant reductions in AIDS-related morbidity and mortality and better quality of life for patients. However, the rate of diagnosis of new cases of HIV among the adult population is on the increase due to high-risk sexual behavior practices, particularly not using condoms, sexual relations with a large number of partners and starting sexual relations at a younger age, with unplanned pregnancies and sexually transmitted infections (STIs), including HIV. For this reason, public health managers have invested considerable effort in recent years in creating STI and HIV prevention programs. Yet, in spite of the implementation of measures for reducing the rates of infection, few studies have been published in Spain comparing individuals living with HIV with the general population about cognitive variables and the link between these variables and high-risk sexual behavior. The objective was to compare a group of individuals living with HIV with another group from the general population in terms of cognitive variables (knowledge about STIs and HIV, concern about STI/HIV and pregnancy, self-efficacy to refuse sexual relations and resilience) and sexual behavior. The sample consisted of 318 adults, 159 were from the general population and 159 were individuals living with HIV. Individuals living with HIV had higher scores for concern about HIV/AIDS, STIs, pregnancy and knowledge of STI/HIV compared with the general population. We concluded that uninfected people who had low and high level of concern about HIV/AIDS began having anal sex at a younger age than those with a medium level of concern. Overall, results indicate that the concern about HIV/AIDS should be addressed in preventive health interventions to minimize the risks of sexual behavior.

Effects of a common transcranial direct current stimulation (tDCS) protocol on motor evoked potentials found to be highly variable within individuals over 9 testing sessions.

PubMed

Horvath, Jared Cooney; Vogrin, Simon J; Carter, Olivia; Cook, Mark J; Forte, Jason D

2016-09-01

Transcranial direct current stimulation (tDCS) uses a weak electric current to modulate neuronal activity. A neurophysiologic outcome measure to demonstrate reliable tDCS modulation at the group level is transcranial magnetic stimulation engendered motor evoked potentials (MEPs). Here, we conduct a study testing the reliability of individual MEP response patterns following a common tDCS protocol. Fourteen participants (7m/7f) each underwent nine randomized sessions of 1 mA, 10 min tDCS (3 anode; 3 cathode; 3 sham) delivered using an M1/orbito-frontal electrode montage (sessions separated by an average of ~5.5 days). Fifteen MEPs were obtained prior to, immediately following and in 5 min intervals for 30 min following tDCS. TMS was delivered at 130 % resting motor threshold using neuronavigation to ensure consistent coil localization. A number of non-experimental variables were collected during each session. At the individual level, considerable variability was seen among different testing sessions. No participant demonstrated an excitatory response ≥20 % to all three anodal sessions, and no participant demonstrated an inhibitory response ≥20 % to all three cathodal sessions. Intra-class correlation revealed poor anodal and cathodal test-retest reliability [anode: ICC(2,1) = 0.062; cathode: ICC(2,1) = 0.055] and moderate sham test-retest reliability [ICC(2,1) = 0.433]. Results also revealed no significant effect of tDCS at the group level. Using this common protocol, we found the effects of tDCS on MEP amplitudes to be highly variable at the individual level. In addition, no significant effects of tDCS on MEP amplitude were found at the group level. Future studies should consider utilizing a more strict experimental protocol to potentially account for intra-individual response variations.

Examining variations in health within rural Canada.

PubMed

Lavergne, M Ruth; Kephart, George

2012-01-01

Differences in health between urban and rural areas of Canada are well documented. Canadian rural communities are remarkably heterogeneous in terms of social, economic, and geographic characteristics. There is reason to believe that there is also considerable heterogeneity in health within rural Canada but existing literature has not given this adequate consideration. This article describes heterogeneity in health along the urban-rural continuum, both between and within categories of rural areas. Factors that may explain observed variations are then examined. The study population included all adult (>18 years) respondents on the Canadian Community Health Survey Cycle 1.1, linked to census subdivision-level data from the corresponding Canadian Census. Study areas were classified according to Metropolitan Influenced Zones (MIZ), which group rural areas based on their degree of connectivity with nearby urban areas. Dichotomized Health Utilities Index (HUI) scores were the outcome variable. Random-intercept logistic regression models investigated the associations of HUI with individual and area characteristics. To describe between-area variation in health, the proportion of the total variation accounted for by the area random effect (the intra-class correlation coefficient [ICC]) was estimated. To aid interpretation of the magnitude of the effect of area relative to other variables in the models, the ICC was also expressed as a median odds ratio (MOR), or the median amount by which the probability of disability will change for an individual who moves from one area to another. On a descriptive level, poorer health was observed in more remote rural areas, but the size of estimated effects for categories of rural areas was generally small compared with effects of other individual and area variables, and with the degree of heterogeneity between areas. The composition of rural areas is important in order to understand patterns in health. Individual income, education, and employment, and area characteristics such as Francophone or Aboriginal populations, and migration patterns help explain the gradient in health by MIZ, but considerable heterogeneity in health within categories of MIZ remains. In models stratified by MIZ, significant between-area heterogeneity was observed in all models, with MORs ranging from 1.18 to 1.53. It was observed that heterogeneity in health among rural areas is substantial, and generally larger than the effect of rurality, itself, on health. More attention is needed to understand the characteristics of Canada's heterogeneous rural communities, and the different processes by which disparities in health emerge and persist. The findings suggest that a focus on rurality alone, emphasizing urban versus rural disparities, or even continuum-based approaches like MIZ, may be less informative than finding ways to classify and examine different types of rural areas according to factors relevant to health.

[Crucial stages of embryogenesis of R. arvalis: Part 1. Linear measurements of embryonic structures].

PubMed

Severtsova, E A; Severtsov, A S

2011-01-01

Investigations of individual variability have allowed us to reveal the crucial (= nodal) stages in embryogenesis of the moor frog (Rana arvalis Nills.). These crucial stages are: the late gastrula stage (stages 18-20), the hatching stages (stages 32-33) and, apparently, early metamorphosis (stage 39). Moreover, we have found that each embryonic structure passes through its specific crucial stages. For example, stage 34 is crucial for the trait "tail width" but is internodal for all other embryonic traits. At this stage, larva passes from an attached to a free-swimming life style. We also found considerable differences between the different frog populations in the the level of developmental variability. These differences were associated with internodal developmental stages.

Oral contraceptive use and female genital arousal: methodological considerations.

PubMed

Seal, Brooke N; Brotto, Lori A; Gorzalka, Boris B

2005-08-01

This study explored effects of oral contraceptive pill (OCP) use on physiological sexual arousal as measured by a vaginal photoplethysmograph. Sixteen women aged 18-29 viewed audiovisual neutral and erotic stimuli before and an average of 6 weeks following the onset of OCP use. Although subjective measures of sexual arousal, including perceptions of genital arousal, significantly increased in response to erotic stimuli both before and after OCP onset, physiological sexual arousal only increased before OCP use. A comparison of individual responses before and after OCP onset reveals a much higher degree of intrasubject variability after OCP onset. We discuss these findings as they relate to OCP use as a confounding methodological variable to consider in future investigations employing vaginal photoplethysmography.

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities

PubMed Central

Saez, M; Figueiras, A; Ballester, F; Perez-Hoyos, S; Ocana, R; Tobias, A

2001-01-01

STUDY OBJECTIVE—The objective of this paper is to introduce a different approach, called the ecological-longitudinal, to carrying out pooled analysis in time series ecological studies. Because it gives a larger number of data points and, hence, increases the statistical power of the analysis, this approach, unlike conventional ones, allows the complementation of aspects such as accommodation of random effect models, of lags, of interaction between pollutants and between pollutants and meteorological variables, that are hardly implemented in conventional approaches.
DESIGN—The approach is illustrated by providing quantitative estimates of the short-term effects of air pollution on mortality in three Spanish cities, Barcelona, Valencia and Vigo, for the period 1992-1994. Because the dependent variable was a count, a Poisson generalised linear model was first specified. Several modelling issues are worth mentioning. Firstly, because the relations between mortality and explanatory variables were non-linear, cubic splines were used for covariate control, leading to a generalised additive model, GAM. Secondly, the effects of the predictors on the response were allowed to occur with some lag. Thirdly, the residual autocorrelation, because of imperfect control, was controlled for by means of an autoregressive Poisson GAM. Finally, the longitudinal design demanded the consideration of the existence of individual heterogeneity, requiring the consideration of mixed models.
MAIN RESULTS—The estimates of the relative risks obtained from the individual analyses varied across cities, particularly those associated with sulphur dioxide. The highest relative risks corresponded to black smoke in Valencia. These estimates were higher than those obtained from the ecological-longitudinal analysis. Relative risks estimated from this latter analysis were practically identical across cities, 1.00638 (95% confidence intervals 1.0002, 1.0011) for a black smoke increase of 10 µg/m3 and 1.00415 (95% CI 1.0001, 1.0007) for a increase of 10 µg/m3 of sulphur dioxide. Because the statistical power is higher than in the individual analysis more interactions were statistically significant, especially those among air pollutants and meteorological variables.
CONCLUSIONS—Air pollutant levels were related to mortality in the three cities of the study, Barcelona, Valencia and Vigo. These results were consistent with similar studies in other cities, with other multicentric studies and coherent with both, previous individual, for each city, and multicentric studies for all three cities.


Keywords: air pollution; mortality; longitudinal studies PMID:11351001

The Association Between Body Image and Smoking Cessation Among Individuals Living with HIV/AIDS

PubMed Central

Fingeret, Michelle Cororve; Vidrine, Damon J.; Arduino, Roberto C.; Gritz, Ellen R.

2007-01-01

Lower smoking cessation rates are associated with body image concerns in the general population. This relationship is particularly important to study in individuals living with HIV/AIDS due to alarmingly high smoking rates and considerable bodily changes experienced with HIV disease progression and treatment. The association between body image and smoking cessation rates was examined among individuals living with HIV/AIDS participating in a smoking cessation intervention. Body image concerns were significantly associated with depression, anxiety, stress, and social support, all variables known to affect cessation rates. However, reduced quit rates were found among individuals reporting elevated and low levels of body image concerns at the end of treatment. These findings suggest a unique relationship between smoking and body image among individuals living with HIV/AIDS. Further research is needed to examine these effects and whether moderate levels of body image concerns in this population reflect realistic body perceptions associated with positive mental health. PMID:18089265

Enhanced Requirements for Assessment in a Competency-Based, Time-Variable Medical Education System.

PubMed

Gruppen, Larry D; Ten Cate, Olle; Lingard, Lorelei A; Teunissen, Pim W; Kogan, Jennifer R

2018-03-01

Competency-based, time-variable medical education has reshaped the perceptions and practices of teachers, curriculum designers, faculty developers, clinician educators, and program administrators. This increasingly popular approach highlights the fact that learning among different individuals varies in duration, foundation, and goal. Time variability places particular demands on the assessment data that are so necessary for making decisions about learner progress. These decisions may be formative (e.g., feedback for improvement) or summative (e.g., decisions about advancing a student). This article identifies challenges to collecting assessment data and to making assessment decisions in a time-variable system. These challenges include managing assessment data, defining and making valid assessment decisions, innovating in assessment, and modeling the considerable complexity of assessment in real-world settings and richly interconnected social systems. There are hopeful signs of creativity in assessment both from researchers and practitioners, but the transition from a traditional to a competency-based medical education system will likely continue to create much controversy and offer opportunities for originality and innovation in assessment.

Informing family members of individuals with Lynch syndrome: a guideline for clinical geneticists.

PubMed

Menko, Fred H; Aalfs, Cora M; Henneman, Lidewij; Stol, Yrrah; Wijdenes, Miranda; Otten, Ellen; Ploegmakers, Marleen M J; Legemaate, Johan; Smets, Ellen M A; de Wert, Guido M W R; Tibben, Aad

2013-06-01

The diagnosis of Lynch syndrome can lead to the prevention of colorectal cancer through periodic colonoscopies and removal of premalignant lesions in susceptible individuals. Therefore, predisposed individuals identified by mutation analysis are advised to inform their at-risk relatives about the options of predictive DNA testing and preventive measures. However, it has now been established that more than half of these relatives do not receive the necessary information. Barriers in conveying information include family communication problems and variable attitudes and practice among clinical geneticists. In this complex field, both medical, psychological, ethical and juridical aspects deserve consideration. Here we summarize the development of a revised guideline for clinical geneticists that allows a more active role of the geneticist, aimed at improving procedures to inform family members in Lynch syndrome and other hereditary and familial cancer syndromes.

Stage effects on stalling and recovery of a high-speed 10-stage axial-flow compressor

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

Copenhaver, W.W.

1988-01-01

Results of a high-speed 10-stage axial-flow compressor test involving overall compressor and individual stage performance while stalling and operating in quasi-steady rotating stall are described. Test procedures and data-acquisition methods used to obtain the dynamic stalling and quasi-steady in-stall data are explained. Unstalled and in-stall time-averaged data obtained from the compressor operating at five different shaft speeds and one off-schedule variable vane condition are presented. Effects of compressor speed and variable geometry on overall compressor in-stall pressure rise and hysteresis extent are illustrated through the use of quasi-steady-stage temperature rise and pressure-rise characteristics. Results indicate that individual stage performance duringmore » overall compressor rotating stall operation varies considerably throughout the length of the compressor. The measured high-speed 10-stage test compressor individual stage pressure and temperature characteristics were input into a stage-by-stage dynamic compressor performance model. Comparison of the model results and measured pressures provided the additional validation necessary to demonstrate the model's ability to predict high-speed multistage compressor stalling and in-stall performance.« less

PREDICTING RECIDIVISM FOR RELEASED STATE PRISON OFFENDERS

PubMed Central

Stahler, Gerald J.; Mennis, Jeremy; Belenko, Steven; Welsh, Wayne N.; Hiller, Matthew L.; Zajac, Gary

2013-01-01

We examined the influence of individual and neighborhood characteristics and spatial contagion in predicting reincarceration on a sample of 5,354 released Pennsylvania state prisoners. Independent variables included demographic characteristics, offense type, drug involvement, various neighborhood variables (e.g., concentrated disadvantage, residential mobility), and spatial contagion (i.e., proximity to others who become reincarcerated). Using geographic information systems (GIS) and logistic regression modeling, our results showed that the likelihood of reincarceration was increased with male gender, drug involvement, offense type, and living in areas with high rates of recidivism. Older offenders and those convicted of violent or drug offenses were less likely to be reincarcerated. For violent offenders, drug involvement, age, and spatial contagion were particular risk factors for reincarceration. None of the neighborhood environment variables were associated with increased risk of reincarceration. Reentry programs need to particularly address substance abuse issues of ex-offenders as well as take into consideration their residential locations. PMID:24443612

Weaver syndrome and EZH2 mutations: Clarifying the clinical phenotype.

PubMed

Tatton-Brown, Katrina; Murray, Anne; Hanks, Sandra; Douglas, Jenny; Armstrong, Ruth; Banka, Siddharth; Bird, Lynne M; Clericuzio, Carol L; Cormier-Daire, Valerie; Cushing, Tom; Flinter, Frances; Jacquemont, Marie-Line; Joss, Shelagh; Kinning, Esther; Lynch, Sally Ann; Magee, Alex; McConnell, Vivienne; Medeira, Ana; Ozono, Keiichi; Patton, Michael; Rankin, Julia; Shears, Debbie; Simon, Marleen; Splitt, Miranda; Strenger, Volker; Stuurman, Kyra; Taylor, Clare; Titheradge, Hannah; Van Maldergem, Lionel; Temple, I Karen; Cole, Trevor; Seal, Sheila; Rahman, Nazneen

2013-12-01

Weaver syndrome, first described in 1974, is characterized by tall stature, a typical facial appearance, and variable intellectual disability. In 2011, mutations in the histone methyltransferase, EZH2, were shown to cause Weaver syndrome. To date, we have identified 48 individuals with EZH2 mutations. The mutations were primarily missense mutations occurring throughout the gene, with some clustering in the SET domain (12/48). Truncating mutations were uncommon (4/48) and only identified in the final exon, after the SET domain. Through analyses of clinical data and facial photographs of EZH2 mutation-positive individuals, we have shown that the facial features can be subtle and the clinical diagnosis of Weaver syndrome is thus challenging, especially in older individuals. However, tall stature is very common, reported in >90% of affected individuals. Intellectual disability is also common, present in ~80%, but is highly variable and frequently mild. Additional clinical features which may help in stratifying individuals to EZH2 mutation testing include camptodactyly, soft, doughy skin, umbilical hernia, and a low, hoarse cry. Considerable phenotypic overlap between Sotos and Weaver syndromes is also evident. The identification of an EZH2 mutation can therefore provide an objective means of confirming a subtle presentation of Weaver syndrome and/or distinguishing Weaver and Sotos syndromes. As mutation testing becomes increasingly accessible and larger numbers of EZH2 mutation-positive individuals are identified, knowledge of the clinical spectrum and prognostic implications of EZH2 mutations should improve. © 2013 Wiley Periodicals, Inc.

The biology of personalized cancer medicine: facing individual complexities underlying hallmark capabilities.

PubMed

De Palma, Michele; Hanahan, Douglas

2012-04-01

It is a time of great promise and expectation for the applications of knowledge about mechanisms of cancer toward more effective and enduring therapies for human disease. Conceptualizations such as the hallmarks of cancer are providing an organizing principle with which to distill and rationalize the abject complexities of cancer phenotypes and genotypes across the spectrum of the human disease. A countervailing reality, however, involves the variable and often transitory responses to most mechanism-based targeted therapies, returning full circle to the complexity, arguing that the unique biology and genetics of a patient's tumor will in the future necessarily need to be incorporated into the decisions about optimal treatment strategies, the frontier of personalized cancer medicine. This perspective highlights considerations, metrics, and methods that may prove instrumental in charting the landscape of evaluating individual tumors so to better inform diagnosis, prognosis, and therapy. Integral to the consideration is remarkable heterogeneity and variability, evidently embedded in cancer cells, but likely also in the cell types composing the supportive and interactive stroma of the tumor microenvironment (e.g., leukocytes and fibroblasts), whose diversity in form, regulation, function, and abundance may prove to rival that of the cancer cells themselves. By comprehensively interrogating both parenchyma and stroma of patients' cancers with a suite of parametric tools, the promise of mechanism-based therapy may truly be realized. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Engine design considerations for 2nd generation supersonic transports

NASA Technical Reports Server (NTRS)

Howlett, R. A.

1975-01-01

The environmental and economic goals projected for advanced supersonic transports will require revolutionary improvements in propulsion systems. Variable cycle engine concepts that incorporate unique components and advanced technologies show promise in meeting these goals. Pratt & Whitney Aircraft is conducting conceptual design studies of variable cycle engine concepts under NASA sponsorship. This paper reviews some of the design considerations for these engine concepts. Emphasis is placed on jet noise abatement, reduction of emissions, performance improvements, installation considerations, hot-section characteristics and control system requirements. Two representative variable cycle engine concepts that incorporate these basic design considerations are described.

Challenges in acute heart failure clinical management: optimizing care despite incomplete evidence and imperfect drugs.

PubMed

Teichman, Sam L; Maisel, Alan S; Storrow, Alan B

2015-03-01

Acute heart failure is a common condition associated with considerable morbidity, mortality, and cost. However, evidence-based data on treating heart failure in the acute setting are limited, and current individual treatment options have variable efficacy. The healthcare team must often individualize patient care in ways that may extend beyond available clinical guidelines. In this review, we address the question, "How do you do the best you can clinically with incomplete evidence and imperfect drugs?" Expert opinion is provided to supplement guideline-based recommendations and help address the typical challenges that are involved in the management of patients with acute heart failure. Specifically, we discuss 4 key areas that are important in the continuum of patient care: differential diagnosis and risk stratification; choice and implementation of initial therapy; assessment of the adequacy of therapy during hospitalization or observation; and considerations for discharge/transition of care. A case study is presented to highlight the decision-making process throughout each of these areas. Evidence is accumulating that should help guide patients and healthcare providers on a path to better quality of care.

Clinal variation in the juvenal plumage of American kestrels

USGS Publications Warehouse

Smallwood, J.A.; Natale, C.; Steenhof, K.; Meetz, M.; Marti, C.D.; Melvin, R.J.; Bortolotti, G.R.; Robertson, R.; Robertson, S.; Shuford, W.R.; Lindemann, S.A.; Tornwall, B.

1999-01-01

The American Kestrel(Falco sparverius) is a sexually dichromatic falcon that exhibits considerable individual plumage variability. For example, the anterior extent of the black dorsal barring in juvenile males has been used throughout North America as one of several aging criteria, but recent data demonstrate that the variability among individual Southeastern American Kestrels(E S. paulus)exceeds that accounted for by age. The objective of this study was to search for geographic patterns in the variability of juvenal plumage, particularly those characteristics considered indicative of age. Nestling kestrels (n = 610) were examined prior to fledging during the 1997 breeding season at nest box programs across a large portion of the North American breeding range. From south to north (1) the crown patches of both males and females become more completely rufous, and (2) shaft streaks on forehead and crown feathers become more pronounced, especially in males. Male Southeastern American Kestrels differed from other males (E s. sparverius) in that the anterior extent of dorsal barring averaged less but was more variable. The variability observed in North America appears to be part of a cline extending across the species range in the Western Hemisphere, where tropical subspecies are small and have reduced dorsal barring. Both body size and, especially in males, dorsal barring increases with increasing north and south latitude. We suggest that this geographic pattern is adaptive in terms of thermoregulation, and that differences in the sex roles may explain why males become less barred with maturity while females do not.

[Night-to-night variability of the obstructive sleep apnoea-hypopnoea syndrome].

PubMed

Mjid, M; Ouahchi, Y; Toujani, S; Snen, H; Ben Salah, N; Ben Hmida, A; Louzir, B; Mhiri, N; Cherif, J; Beji, M

2016-11-01

The apnoea-hypopnoea index (AHI) is the primary measurement used to characterize the obstructive sleep apnoea-hypopnoea syndrome (OSAHS). Despite its popularity, there are limiting factors to its application such as night-to-night variability. To evaluate the variability of AHI in the OSAHS. A prospective study was designed in our university hospital's sleep unit. Adults with clinical suspicion of OSAHS underwent 2 consecutive nights of polysomnographic recording. The population was divided in two groups according to an AHI>or<10. Patients with psychiatric disorders or professions that might result in sleep deprivation or an altered sleep/wake cycle were excluded. Twenty patients were enrolled. The mean age was 50.6±9.3 years. OSAHS was mild in 4 cases, moderate in 6 cases and severe in 8 cases. AHI was less than 5 in two cases. AHI values were not significantly altered throughout both recording nights (33.2 vs. 31.8 events/h). A significant positive correlation was found between AHI measured on the first and the second night. However, a significant individual variability was noted. Comparison between both patient's groups showed a correlation between AHI and the body mass index. This study demonstrates that the AHI in OSAHS patients is well correlated between two consecutive nights. However, a significant individual variability should be taken into consideration, especially when AHI is used in the classification of OSAHS or as a criterion of therapeutic success. Copyright © 2016. Published by Elsevier Masson SAS.

A matter of hand: Causal links between hand dominance, structural organization of fronto-parietal attention networks, and variability in behavioural responses to transcranial magnetic stimulation.

PubMed

Cazzoli, Dario; Chechlacz, Magdalena

2017-01-01

Considerable evidence suggests that, on a group level, human visuospatial attention is asymmetrically organized, with a right-hemispheric dominance. The asymmetrical organization of the superior longitudinal fasciculus (SLF) has been shown to account for the right-hemispheric dominance in visual attention. However, such account is by no means universal, and large individual differences in asymmetrical performance on visuospatial tasks have been reported. Furthermore, the variability in the SLF lateralization has been shown to correlate with behavioural asymmetries. Continuous theta burst stimulation (cTBS) enables to temporarily interfere with cortical activity. cTBS applied over the posterior parietal cortex (PPC) has been previously used to systematically study attentional asymmetries. Interestingly, large individual differences in the effectiveness of stimulation have been reported. In accordance with earlier both animal and human studies, one possible cause underlying these striking individual differences might lie in the structural organization of frontoparietal pathways subserving visuospatial attention. Thus, the current study employed diffusion tractography to examine the relationship between the variability in the structural organization of the SLF and the individual differences in attentional shifts induced by a modified cTBS (cTBS mod ; triplets of pulses at 30 Hz, repeated at 6 Hz) applied over the IPS, as measured by a line bisection task. Consistent with previous studies, on a group level, cTBS mod applied over the right intraparietal sulcus (IPS) triggered a rightward bisection bias shift, and there were no significant effects of cTBS mod applied over the left IPS. However, further analyses demonstrated that both handedness and structural variability (as assessed based on hindrance modulated orientational anisotropy) within the middle and the ventral branches of the SLF predicted individual differences in the cTBS mod -induced attentional shifts. Our study thus suggests that the effects of cTBS mod over the IPS may depend on intra-hemispheric interactions between cortical loci controlling visual attention. To conclude, our findings provide converging evidence for the notion put forward previously that inter-individual variability in the structural organization of intra-hemispheric frontoparietal connections has important implications for the functional models of human visual attention. Moreover, we hypothesize that this may also be relevant for the understanding of attentional disorders and their rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predator Persistence through Variability of Resource Productivity in Tritrophic Systems.

PubMed

Soudijn, Floor H; de Roos, André M

2017-12-01

The trophic structure of species communities depends on the energy transfer between trophic levels. Primary productivity varies strongly through time, challenging the persistence of species at higher trophic levels. Yet resource variability has mostly been studied in systems with only one or two trophic levels. We test the effect of variability in resource productivity in a tritrophic model system including a resource, a size-structured consumer, and a size-specific predator. The model complies with fundamental principles of mass conservation and the body-size dependence of individual-level energetics and predator-prey interactions. Surprisingly, we find that resource variability may promote predator persistence. The positive effect of variability on the predator arises through periods with starvation mortality of juvenile prey, which reduces the intraspecific competition in the prey population. With increasing variability in productivity and starvation mortality in the juvenile prey, the prey availability increases in the size range preferred by the predator. The positive effect of prey mortality on the trophic transfer efficiency depends on the biologically realistic consideration of body size-dependent and food-dependent functions for growth and reproduction in our model. Our findings show that variability may promote the trophic transfer efficiency, indicating that environmental variability may sustain species at higher trophic levels in natural ecosystems.

Evaluation of trace elements in lung samples from coal miners using neutron activation analysis.

PubMed

Saiki, M; Saldiva, P H; Alice, S H

1999-01-01

In this study, instrumental neutron activation analysis was applied to the determination of Sc, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Th, and U in lung samples from miners working in coal mines located in the state of Santa Catarina, Brazil. These results were compared to those from a control group constituted of healthy individuals. The results showed that the elements determined exhibit considerable intersubject variability within a single group of individuals and the mean values of concentrations in miners' lungs were higher than those of normal individuals. Lung samples presented U concentrations varying from 11 to 890 micrograms/kg. Therefore, for some samples, the contribution of the uranium fission products in the analysis of La, Ce, Nd, and Sm was considered by determining the interference correction factors. The accuracy of the results was evaluated by analyzing certified reference materials.

Returners and explorers dichotomy in human mobility

PubMed Central

Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

2015-01-01

The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions. PMID:26349016

Predictors of Outcomes in Autism Early Intervention: Why Don’t We Know More?

PubMed Central

Vivanti, Giacomo; Prior, Margot; Williams, Katrina; Dissanayake, Cheryl

2014-01-01

Response to early intervention programs in autism is variable. However, the factors associated with positive versus poor treatment outcomes remain unknown. Hence the issue of which intervention/s should be chosen for an individual child remains a common dilemma. We argue that lack of knowledge on “what works for whom and why” in autism reflects a number of issues in current approaches to outcomes research, and we provide recommendations to address these limitations. These include: a theory-driven selection of putative predictors; the inclusion of proximal measures that are directly relevant to the learning mechanisms demanded by the specific educational strategies; the consideration of family characteristics. Moreover, all data on associations between predictor and outcome variables should be reported in treatment studies. PMID:24999470

Effect of signal jitter on the spectrum of rotor impulsive noise

NASA Technical Reports Server (NTRS)

Brooks, Thomas F.

1987-01-01

The effect of randomness or jitter of the acoustic waveform on the spectrum of rotor impulsive noise is studied because of its importance for data interpretation. An acoustic waveform train is modelled representing rotor impulsive noise. The amplitude, shape, and period between occurrences of individual pulses are allowed to be randomized assuming normal probability distributions. Results, in terms of the standard deviations of the variable quantities, are given for the autospectrum as well as special processed spectra designed to separate harmonic and broadband rotor noise components. Consideration is given to the effect of accuracy in triggering or keying to a rotor one per revolution signal. An example is given showing the resultant spectral smearing at the high frequencies due to the pulse signal period variability.

Effect of signal jitter on the spectrum of rotor impulsive noise

NASA Technical Reports Server (NTRS)

Brooks, Thomas F.

1988-01-01

The effect of randomness or jitter of the acoustic waveform on the spectrum of rotor impulsive noise is studied because of its importance for data interpretation. An acoustic waveform train is modeled representing rotor impulsive noise. The amplitude, shape, and period between occurrences of individual pulses are allowed to be randomized assuming normal probability distributions. Results, in terms of the standard deviations of the variable quantities, are given for the autospectrum as well as special processed spectra designed to separate harmonic and broadband rotor noise components. Consideration is given to the effect of accuracy in triggering or keying to a rotor one per revolution signal. An example is given showing the resultant spectral smearing at the high frequencies due to the pulse signal period variability.

Software for Dosage Individualization of Voriconazole for Immunocompromised Patients

PubMed Central

VanGuilder, Michael; Donnelly, J. Peter; Blijlevens, Nicole M. A.; Brüggemann, Roger J. M.; Jelliffe, Roger W.; Neely, Michael N.

2013-01-01

The efficacy of voriconazole is potentially compromised by considerable pharmacokinetic variability. There are increasing insights into voriconazole concentrations that are safe and effective for treatment of invasive fungal infections. Therapeutic drug monitoring is increasingly advocated. Software to aid in the individualization of dosing would be an extremely useful clinical tool. We developed software to enable the individualization of voriconazole dosing to attain predefined serum concentration targets. The process of individualized voriconazole therapy was based on concepts of Bayesian stochastic adaptive control. Multiple-model dosage design with feedback control was used to calculate dosages that achieved desired concentration targets with maximum precision. The performance of the software program was assessed using the data from 10 recipients of an allogeneic hematopoietic stem cell transplant (HSCT) receiving intravenous (i.v.) voriconazole. The program was able to model the plasma concentrations with a high level of precision, despite the wide range of concentration trajectories and interindividual pharmacokinetic variability. The voriconazole concentrations predicted after the last dosages were largely concordant with those actually measured. Simulations provided an illustration of the way in which the software can be used to adjust dosages of patients falling outside desired concentration targets. This software appears to be an extremely useful tool to further optimize voriconazole therapy and aid in therapeutic drug monitoring. Further prospective studies are now required to define the utility of the controller in daily clinical practice. PMID:23380734

Data mining identifies Digit Symbol Substitution Test score and serum cystatin C as dominant predictors of mortality in older men and women.

PubMed

Swindell, William R; Cummings, Steven R; Sanders, Jason L; Caserotti, Paolo; Rosano, Caterina; Satterfield, Suzanne; Strotmeyer, Elsa S; Harris, Tamara B; Simonsick, Eleanor M; Cawthon, Peggy M

2012-08-01

Characterization of long-term health trajectory in older individuals is important for proactive health management. However, the relative prognostic value of information contained in clinical profiles of nonfrail older adults is often unclear. We screened 825 phenotypic and genetic measures evaluated during the Health, Aging, and Body Composition Study (Health ABC) baseline visit (3,067 men and women aged 70-79). Variables that best predicted mortality over 13 years of follow-up were identified using 10-fold cross-validation. Mortality was most strongly associated with low Digit Symbol Substitution Test (DSST) score (DSST<25; 21.9% of cohort; hazard ratio [HR]=1.87±0.06) and elevated serum cystatin C (≥1.30 mg/mL; 12.1% of cohort; HR=2.25±0.07). These variables predicted mortality better than 823 other measures, including baseline age and a 45-variable health deficit index. Given elevated cystatin C (≥1.30 mg/mL), mortality risk was further increased by high serum creatinine, high abdominal visceral fat density, and smoking history (2.52≤HR ≤3.73). Given a low DSST score (<25) combined with low-to-moderate cystatin C (<1.30 mg/mL), mortality risk was highest among those with elevated plasma resistin and smoking history (1.90≤HR≤2.02). DSST score and serum cystatin C warrant priority consideration for the evaluation of mortality risk in older individuals. Both variables, taken individually, predict mortality better than chronological age or a health deficit index in well-functioning older adults (ages 70-79). DSST score and serum cystatin C can thus provide evidence-based tools for geriatric assessment.

Revisiting gender, race, and ear differences in peripheral auditory function

NASA Astrophysics Data System (ADS)

Boothalingam, Sriram; Klyn, Niall A. M.; Stiepan, Samantha M.; Wilson, Uzma S.; Lee, Jungwha; Siegel, Jonathan H.; Dhar, Sumitrajit

2018-05-01

Various measures of auditory function are reported to be superior in females as compared to males, in African American compared to Caucasian individuals, and in right compared to left ears. We re-examined the influence of these subject variables on hearing thresholds and otoacoustic emissions (OAEs) in a sample of 887 human participants between 10 and 68 years of age. Even though the variables of interest here have been examined before, previous attempts have largely been limited to frequencies up to 8 kHz. We used state-of-the-art signal delivery and recording techniques that compensated for individual differences in ear canal acoustics, allowing us to measure hearing thresholds and OAEs up to 20 kHz. The use of these modern calibration and recording techniques provided the motivation for re-examining these commonly studied variables. While controlling for age, noise exposure history, and general health history, we attempted to isolate the effects of gender, race, and ear (left versus right) on hearing thresholds and OAEs. Our results challenge the notion of a right ear advantage and question the existence of a significant gender and race differences in both hearing thresholds and OAE levels. These results suggest that ear canal anatomy and acoustics should be important considerations when evaluating the influence of gender, race, and ear on peripheral auditory function.

Accumulating Data to Optimally Predict Obesity Treatment (ADOPT) Core Measures: Behavioral Domain.

PubMed

Lytle, Leslie A; Nicastro, Holly L; Roberts, Susan B; Evans, Mary; Jakicic, John M; Laposky, Aaron D; Loria, Catherine M

2018-04-01

The ability to identify and measure behaviors that are related to weight loss and the prevention of weight regain is crucial to understanding the variability in response to obesity treatment and the development of tailored treatments. The overarching goal of the Accumulating Data to Optimally Predict obesity Treatment (ADOPT) Core Measures Project is to provide obesity researchers with guidance on a set of constructs and measures that are related to weight control and that span and integrate obesity-related behavioral, biological, environmental, and psychosocial domains. This article describes how the behavioral domain subgroup identified the initial list of high-priority constructs and measures to be included, and it describes practical considerations for assessing the following four behavioral areas: eating, activity, sleep, and self-monitoring of weight. Challenges and considerations for advancing the science related to weight loss and maintenance behaviors are also discussed. Assessing a set of core behavioral measures in combination with those from other ADOPT domains is critical to improve our understanding of individual variability in response to adult obesity treatment. The selection of behavioral measures is based on the current science, although there continues to be much work needed in this field. © 2018 The Obesity Society.

Modelling approaches: the case of schizophrenia.

PubMed

Heeg, Bart M S; Damen, Joep; Buskens, Erik; Caleo, Sue; de Charro, Frank; van Hout, Ben A

2008-01-01

Schizophrenia is a chronic disease characterized by periods of relative stability interrupted by acute episodes (or relapses). The course of the disease may vary considerably between patients. Patient histories show considerable inter- and even intra-individual variability. We provide a critical assessment of the advantages and disadvantages of three modelling techniques that have been used in schizophrenia: decision trees, (cohort and micro-simulation) Markov models and discrete event simulation models. These modelling techniques are compared in terms of building time, data requirements, medico-scientific experience, simulation time, clinical representation, and their ability to deal with patient heterogeneity, the timing of events, prior events, patient interaction, interaction between co-variates and variability (first-order uncertainty). We note that, depending on the research question, the optimal modelling approach should be selected based on the expected differences between the comparators, the number of co-variates, the number of patient subgroups, the interactions between co-variates, and simulation time. Finally, it is argued that in case micro-simulation is required for the cost-effectiveness analysis of schizophrenia treatments, a discrete event simulation model is best suited to accurately capture all of the relevant interdependencies in this chronic, highly heterogeneous disease with limited long-term follow-up data.

CFD-Based Design Optimization for Single Element Rocket Injector

NASA Technical Reports Server (NTRS)

Vaidyanathan, Rajkumar; Tucker, Kevin; Papila, Nilay; Shyy, Wei

2003-01-01

To develop future Reusable Launch Vehicle concepts, we have conducted design optimization for a single element rocket injector, with overall goals of improving reliability and performance while reducing cost. Computational solutions based on the Navier-Stokes equations, finite rate chemistry, and the k-E turbulence closure are generated with design of experiment techniques, and the response surface method is employed as the optimization tool. The design considerations are guided by four design objectives motivated by the consideration in both performance and life, namely, the maximum temperature on the oxidizer post tip, the maximum temperature on the injector face, the adiabatic wall temperature, and the length of the combustion zone. Four design variables are selected, namely, H2 flow angle, H2 and O2 flow areas with fixed flow rates, and O2 post tip thickness. In addition to establishing optimum designs by varying emphasis on the individual objectives, better insight into the interplay between design variables and their impact on the design objectives is gained. The investigation indicates that improvement in performance or life comes at the cost of the other. Best compromise is obtained when improvements in both performance and life are given equal importance.

Memory bias for threatening information in anxiety and anxiety disorders: a meta-analytic review.

PubMed

Mitte, Kristin

2008-11-01

Although some theories suggest that anxious individuals selectively remember threatening stimuli, findings remain contradictory despite a considerable amount of research. A quantitative integration of 165 studies with 9,046 participants (clinical and nonclinical samples) examined whether a memory bias exists and which moderator variables influence its magnitude. Implicit memory bias was investigated in lexical decision/stimulus identification and word-stem completion paradigms; explicit memory bias was investigated in recognition and recall paradigms. Overall, effect sizes showed no significant impact of anxiety on implicit memory and recognition. Analyses indicated a memory bias for recall, whose magnitude depended on experimental study procedures like the encoding procedure or retention interval. Anxiety influenced recollection of previous experiences; anxious individuals favored threat-related information. Across all paradigms, clinical status was not significantly linked to effect sizes, indicating no qualitative difference in information processing between anxiety patients and high-anxious persons. The large discrepancy between study effects in recall and recognition indicates that future research is needed to identify moderator variables for avoidant and preferred remembering.

Training and overtraining markers in selected sport events.

PubMed

Hartmann, U; Mester, J

2000-01-01

Varieties of symptoms are supposed to detect overtraining (OT). Besides the problems of diagnosis and analysis in elite athletes, a daily monitoring of training status takes place with measurement of the parameters serum urea (SU) and serum creatine kinase (CK); therefore, their meaningfulness will be examined, with special respect inter- and intra-individually. Data were obtained from determinations during training from athletes in rowing and athletes of international level. For 6981 SU determinations (male, N = 717; female, N = 285), a slightly asymmetric normal distribution was found (male, 80%, 5-7 mmol x L(-1); female, 75%, 4-6 mmol x L(-1)). Values for women were approximately 1.5 mmol x L(-1) lower. Individual variability was enormous; there seems little point in setting fixed value as 8.3 mmol x L(-1) for men and 7.0 mmol x L(-1) for women as a critical limit for OT. CK has also been measured and evaluated in sports as an essential parameter for determination of muscular stress. Frequency distributions of CK in 2790 samples (male, N = 497; female, N = 350) presented an asymmetric normal distribution with distinct trend toward higher values being evident for the range between 100 and 250 U x L(-1). Conspicuously elevated values occurred in the ranges 250-350 U x L(-1) and 1000-2000 U x L(-1). Men's maximal values were 3000 U x L(-1) and 1150 U x L(-1) for women. Individual variability was enormous. Athletes with chronically low CK exhibited mainly low variability; those with chronically higher values exhibited considerable variability. Establishment of both parameters should be useful to determine individual baselines from a large number of samples. Determinations should be made at least every 3 d in standardized conditions. If a large increase is observed in combination with reduced exercise tolerance after a phase of exertion (2-4 d), then the possibility of a catabolic/metabolic activity or insufficient exercise tolerance becomes much more likely.

Impact of migration origin on individual protection strategies against sexual transmission of HIV in Paris metropolitan area, SIRS cohort study, France.

PubMed

Kesteman, Thomas; Lapostolle, Annabelle; Costagliola, Dominique; Massari, Véronique; Chauvin, Pierre

2015-08-20

The impact of migration and country or region of origin on sexual behaviours and prevention of the sexual transmission of HIV has been scarcely studied in France. The objective of this study was to evaluate if and how individual attitudes of prevention towards HIV infection are different according to country or region of origins in Paris area, France. 3006 individuals were interviewed in the Paris metropolitan area in 2010. Outcome variables were (i) the intention of the individual to protect oneself against HIV, and (ii) the adoption of a condom-based approach for protection against HIV. To explore factors associated with these outcomes, we constructed multivariate logistic regression models, first taking into account only demographic variables -including country of origin-, then successively adding socioeconomic variables and variables related to sexual behaviour and HIV perception and prevention behaviour. French and foreign people who have origins in Sub-Saharan Africa declared more intentions to protect themselves than French people with French parents (in foreign men, aOR = 3.43 [1.66-7.13]; in foreign women, aOR = 2.94 [1.65-5.23]), but did not declare more recourse to a condom-based approach for protection against HIV (in foreign men, aOR = 1.38 [0.38-4.93]; in foreign women, aOR = 0.93 [0.40-2.18]). Conversely, foreign women and French women from foreign origin, especially from Maghreb (Northern Africa), reported less intention of protection than French women with French parents. These results underline the importance of taking culture and origins of target populations into consideration when designing information, education and communication about HIV and sexually transmitted diseases. These results also draw attention to fractions of the general population that could escape from prevention messages.

Anthropological and palaeopathological analysis of the human remains from three "Tombs of the Nobles" of the necropolis of Thebes-west, upper Egypt.

PubMed

Nerlich, A; Zink, A; Hagedorn, H G; Szeimies, U; Weyss, C

2000-12-01

During several recent excavation campaigns at the necropolis of Sheikh-Abd-el-Gurna, Thebes-West, Upper Egypt, we investigated the human remains of three "Tombs of the Nobles" totalling at least 273 individuals. The investigation covered the human material (skeletons and mummy residues) from the tombs TT-84, TT-85 and TT-95. These tombs had been built in the New Kingdom (approx. 1500-1000 B.C.) and used until the Late period (up to 330 BC). All samples were analyzed macroscopically, isolated findings were further investigated by endoscopic and radiological techniques. The at least 273 individuals covered an age range from newborns to senile individuals with a main age of death between 20 and 40 years of age. The rate of infants and subadults was at 20.2% of all individuals and there was a slight male predominance comprising 54.5% of the adults. In this population a fairly high rate of pathological lesions was seen. Thus, dental conditions generally were poor with a high degree of dental abrasion, an also high rate of carious dental lesions (affecting between 13.8% and 27.7% of the yaws) and consequently a significant number of dental abscesses (mean 15.9%). Residues of trauma were observed in a considerable number of individuals ranging between 12.3% and 22.6% depending on the burial place (mean 15.8%). Inflammatory bone reactions (except the dental abscesses) were present to variable extent, in some locations ranging up to 6.8% of the cases (mean 5.1%). In addition, we noted several cases showing cribra orbitalia (mean 29.2%) and porotic hyperostosis (15.4% of cases), mild to severe osteopenia (7.5%) and in several cases subperiosteal new bone formation suggestive of chronic vitamin D-deficiency ("scurvy") (9.5%). The data support the notion of a significant impairment of living conditions in a high number of individuals. The rates of osteoarthrotic joint alterations were considerably variable depending on the burial places (between 1.9% and 18.5%) providing insight into the physical activities of subpopulations in different locations of the burial places. Similarly, the rate of spondylosis showed also variable extent ranging between 12% and 66.1% of vertebral bodies. In general, our analysis provides evidences that the living conditions in the ancient Egyptian population of one of the main necropoles of Thebes analyzed in this study were quite poor. This is somewhat in contrast to the usually assumed high standard of living of the socially higher population of the capital of ancient Egypt.

Education and trajectories of cognitive decline over 9 years in very old people: methods and risk analysis.

PubMed

Muniz-Terrera, Graciela; Matthews, Fiona; Dening, Tom; Huppert, Felicia A; Brayne, Carol

2009-05-01

the investigation of cognitive decline in the older population has been hampered by analytical considerations. Most studies of older people over prolonged periods suffer from loss to follow-up, yet this has seldom been investigated fully to date. Such considerations limit our understanding of how basic variables such as education can affect cognitive trajectories. we examined cognitive trajectories in a population-based cohort study in Cambridge, UK, of people aged 75 and over in whom multiple interviews were conducted over time. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Socio-demographic variables were measured, including educational level and social class. An age-based quadratic latent growth model was fitted to cognitive scores. The effect of socio-demographic variables was examined on all latent variables and the probability of death and dropout. at baseline, age, education, social class and mobility were associated with cognitive performance. Education and social class were not related to decline or its rate of change. In contrast, poor mobility was associated with lower cognitive performance, increased cognitive decline and increased rate of change of cognitive decline. Gender, age, mobility and cognitive ability predicted death and dropout contrary to much of the current literature, education was not related to rate of cognitive decline or change in this rate as measured by MMSE. Higher levels of education do not appear to protect against cognitive decline, though if the MMSE is used in the diagnostic process, individuals with less education may be diagnosed as having dementia somewhat earlier.

Unemployment among women with multiple sclerosis: the role of coping and perceived stress and support in the workplace.

PubMed

Strober, L B; Arnett, P A

2016-06-01

Unemployment is high among individuals with multiple sclerosis (MS). Certain disease variables and demographics have been found to distinguish employed and unemployed individuals. However, these variables only account for 14-20% of the variance. Other factors, such as coping, perceived stress and social support, in the workforce have been proposed, but not yet fully examined. The purpose of the present investigation was to examine the role of known factors associated with unemployment in MS, as well as coping and perceived work stress and social support. Sixty-eight women with MS were asked about their employment status and reasons for leaving. They completed a comprehensive assessment including measures of cognition, disease symptoms, psychological functioning, coping and stress. Consistent with previous findings, certain disease and demographic variables were associated with being unemployed. In particular, women who left work due to their MS were found to be older, had a longer disease duration and progressive course, reported greater disability and fatigue, and performed worse on a cognitive measure. However, we also found that coping style distinguished those who were employed from those who left work due to their MS. In particular, those who left work reported utilizing maladaptive coping mechanisms such as behavioral disengagement and substance use. With regard to perceived work stress and support, individuals who were employed reported that job security and fellow co-workers were more of an uplift than a hassle in their lives, suggesting some benefit in employment. These findings suggest that further consideration be given to role of coping and perception of the benefit of employment among individuals with MS when making recommendations regarding work decisions.

Extracting Behaviorally Relevant Traits from Natural Stimuli: Benefits of Combinatorial Representations at the Accessory Olfactory Bulb

PubMed Central

Kahan, Anat; Ben-Shaul, Yoram

2016-01-01

For many animals, chemosensation is essential for guiding social behavior. However, because multiple factors can modulate levels of individual chemical cues, deriving information about other individuals via natural chemical stimuli involves considerable challenges. How social information is extracted despite these sources of variability is poorly understood. The vomeronasal system provides an excellent opportunity to study this topic due to its role in detecting socially relevant traits. Here, we focus on two such traits: a female mouse’s strain and reproductive state. In particular, we measure stimulus-induced neuronal activity in the accessory olfactory bulb (AOB) in response to various dilutions of urine, vaginal secretions, and saliva, from estrus and non-estrus female mice from two different strains. We first show that all tested secretions provide information about a female’s receptivity and genotype. Next, we investigate how these traits can be decoded from neuronal activity despite multiple sources of variability. We show that individual neurons are limited in their capacity to allow trait classification across multiple sources of variability. However, simple linear classifiers sampling neuronal activity from small neuronal ensembles can provide a substantial improvement over that attained with individual units. Furthermore, we show that some traits are more efficiently detected than others, and that particular secretions may be optimized for conveying information about specific traits. Across all tested stimulus sources, discrimination between strains is more accurate than discrimination of receptivity, and detection of receptivity is more accurate with vaginal secretions than with urine. Our findings highlight the challenges of chemosensory processing of natural stimuli, and suggest that downstream readout stages decode multiple behaviorally relevant traits by sampling information from distinct but overlapping populations of AOB neurons. PMID:26938460

Extracting Behaviorally Relevant Traits from Natural Stimuli: Benefits of Combinatorial Representations at the Accessory Olfactory Bulb.

PubMed

Kahan, Anat; Ben-Shaul, Yoram

2016-03-01

For many animals, chemosensation is essential for guiding social behavior. However, because multiple factors can modulate levels of individual chemical cues, deriving information about other individuals via natural chemical stimuli involves considerable challenges. How social information is extracted despite these sources of variability is poorly understood. The vomeronasal system provides an excellent opportunity to study this topic due to its role in detecting socially relevant traits. Here, we focus on two such traits: a female mouse's strain and reproductive state. In particular, we measure stimulus-induced neuronal activity in the accessory olfactory bulb (AOB) in response to various dilutions of urine, vaginal secretions, and saliva, from estrus and non-estrus female mice from two different strains. We first show that all tested secretions provide information about a female's receptivity and genotype. Next, we investigate how these traits can be decoded from neuronal activity despite multiple sources of variability. We show that individual neurons are limited in their capacity to allow trait classification across multiple sources of variability. However, simple linear classifiers sampling neuronal activity from small neuronal ensembles can provide a substantial improvement over that attained with individual units. Furthermore, we show that some traits are more efficiently detected than others, and that particular secretions may be optimized for conveying information about specific traits. Across all tested stimulus sources, discrimination between strains is more accurate than discrimination of receptivity, and detection of receptivity is more accurate with vaginal secretions than with urine. Our findings highlight the challenges of chemosensory processing of natural stimuli, and suggest that downstream readout stages decode multiple behaviorally relevant traits by sampling information from distinct but overlapping populations of AOB neurons.

Climate-Driven Crop Yield and Yield Variability and Climate Change Impacts on the U.S. Great Plains Agricultural Production.

PubMed

Kukal, Meetpal S; Irmak, Suat

2018-02-22

Climate variability and trends affect global crop yields and are characterized as highly dependent on location, crop type, and irrigation. U.S. Great Plains, due to its significance in national food production, evident climate variability, and extensive irrigation is an ideal region of investigation for climate impacts on food production. This paper evaluates climate impacts on maize, sorghum, and soybean yields and effect of irrigation for individual counties in this region by employing extensive crop yield and climate datasets from 1968-2013. Variability in crop yields was a quarter of the regional average yields, with a quarter of this variability explained by climate variability, and temperature and precipitation explained these in singularity or combination at different locations. Observed temperature trend was beneficial for maize yields, but detrimental for sorghum and soybean yields, whereas observed precipitation trend was beneficial for all three crops. Irrigated yields demonstrated increased robustness and an effective mitigation strategy against climate impacts than their non-irrigated counterparts by a considerable fraction. The information, data, and maps provided can serve as an assessment guide for planners, managers, and policy- and decision makers to prioritize agricultural resilience efforts and resource allocation or re-allocation in the regions that exhibit risk from climate variability.

Secondary Students' Considerations of Variability in Measurement Activities Based on Authentic Practices

ERIC Educational Resources Information Center

Dierdorp, Adri; Bakker, Arthur; Ben-Zvi, Dani; Makar, Katie

2017-01-01

Measurement activities were designed in this study on the basis of authentic professional practices in which linear regression is used, to study considerations of variability by students in Grade 12 (aged 17-18). The question addressed in this article is: In what ways do secondary students consider variability within these measurement activities?…

Sterilization of granulomas is common in both active and latent tuberculosis despite extensive within-host variability in bacterial killing

PubMed Central

Lin, Philana Ling; Ford, Christopher B.; Coleman, M. Teresa; Myers, Amy J.; Gawande, Richa; Ioerger, Thomas; Sacchettini, James; Fortune, Sarah M.; Flynn, JoAnne L.

2013-01-01

Over 30% of the world’s population is infected with Mycobacterium tuberculosis (Mtb), yet only ~5–10% will develop clinical disease1. Despite considerable effort, we understand little about what distinguishes individuals who progress to active tuberculosis (TB) from those who remain latent for decades. The variable course of disease is recapitulated in cynomolgus macaques infected with Mtb2. Active disease in macaques is defined by clinical, microbiologic and immunologic signs and occurs in ~45% of animals, while the remaining are clinically asymptomatic2,3. Here, we use barcoded Mtb isolates and quantitative measures of culturable and cumulative bacterial burden to show that most lesions are likely founded by a single bacterium and reach similar maximum burdens. Despite common origins, the fate of individual lesions varies substantially within the same host. Strikingly, in active disease, the host sterilizes some lesions even while others progress. Our data suggest that lesional heterogeneity arises, in part, through differential killing of bacteria after the onset of adaptive immunity. Thus, individual lesions follow diverse and overlapping trajectories, suggesting critical responses occur at a lesional level to ultimately determine the clinical outcome of infection. Defining the local factors that dictate outcome will be important in developing effective interventions to prevent active TB. PMID:24336248

Evaluating methods for estimating space-time paths of individuals in calculating long-term personal exposure to air pollution

NASA Astrophysics Data System (ADS)

Schmitz, Oliver; Soenario, Ivan; Vaartjes, Ilonca; Strak, Maciek; Hoek, Gerard; Brunekreef, Bert; Dijst, Martin; Karssenberg, Derek

2016-04-01

Air pollution is one of the major concerns for human health. Associations between air pollution and health are often calculated using long-term (i.e. years to decades) information on personal exposure for each individual in a cohort. Personal exposure is the air pollution aggregated along the space-time path visited by an individual. As air pollution may vary considerably in space and time, for instance due to motorised traffic, the estimation of the spatio-temporal location of a persons' space-time path is important to identify the personal exposure. However, long term exposure is mostly calculated using the air pollution concentration at the x, y location of someone's home which does not consider that individuals are mobile (commuting, recreation, relocation). This assumption is often made as it is a major challenge to estimate space-time paths for all individuals in large cohorts, mostly because limited information on mobility of individuals is available. We address this issue by evaluating multiple approaches for the calculation of space-time paths, thereby estimating the personal exposure along these space-time paths with hyper resolution air pollution maps at national scale. This allows us to evaluate the effect of the space-time path and resulting personal exposure. Air pollution (e.g. NO2, PM10) was mapped for the entire Netherlands at a resolution of 5×5 m2 using the land use regression models developed in the European Study of Cohorts for Air Pollution Effects (ESCAPE, http://escapeproject.eu/) and the open source software PCRaster (http://www.pcraster.eu). The models use predictor variables like population density, land use, and traffic related data sets, and are able to model spatial variation and within-city variability of annual average concentration values. We approximated space-time paths for all individuals in a cohort using various aggregations, including those representing space-time paths as the outline of a persons' home or associated parcel of land, the 4 digit postal code area or neighbourhood of a persons' home, circular areas around the home, and spatial probability distributions of space-time paths during commuting. Personal exposure was estimated by averaging concentrations over these space-time paths, for each individual in a cohort. Preliminary results show considerable differences of a persons' exposure using these various approaches of space-time path aggregation, presumably because air pollution shows large variation over short distances.

Individual Differences in Well-Being in Older Breast Cancer Survivors

PubMed Central

Perkins, Elizabeth A.; Small, Brent J.; Balducci, Lodovico; Extermann, Martine; Robb, Claire; Haley, William E.

2007-01-01

Older women who survive breast cancer may differ significantly in their long-term well-being. Using a risk and protective factors model, we studied predictors of well-being in 127 women age 70 and above with a history of at least one year's survival of breast cancer. Mean post-cancer survivorship was 5.1 years. Using life satisfaction, depression and general health perceptions as outcome variables, we assessed whether demographic variables, cancer-related variables, health status and psychosocial resources predicted variability in well-being using correlational and hierarchical regression analyses. Higher age predicted increased depression but was not associated with life satisfaction or general health perceptions. Cancer-related variables, including duration of survival, and type of cancer treatment, were not significantly associated with survivors' well-being. Poorer health status was associated with poorer well-being in all three dependent variables. After controlling for demographics, cancer-related variables, and health status, higher levels of psychosocial resources including optimism, mastery, spirituality and social support predicted better outcome in all three dependent variables. While many older women survive breast cancer without severe sequelae, there is considerable variability in their well-being after survivorship. Successful intervention with older breast cancer survivors might include greater attention not only to cancer-specific concerns, but also attention to geriatric syndromes and functional impairment, and enhancement of protective psychosocial resources. PMID:17240157

Maintaining activity engagement: individual differences in the process of self-regulating motivation.

PubMed

Sansone, Carol; Thoman, Dustin B

2006-12-01

Typically, models of self-regulation include motivation in terms of goals. Motivation is proposed to differ among individuals as a consequence of the goals they hold as well as how much they value those goals and expect to attain them. We suggest that goal-defined motivation is only one source of motivation critical for sustained engagement. A second source is the motivation that arises from the degree of interest experienced in the process of goal pursuit. Our model integrates both sources of motivation within the goal-striving process and suggests that individuals may actively monitor and regulate them. Conceptualizing motivation in terms of a self-regulatory process provides an organizing framework for understanding how individuals might differ in whether they experience interest while working toward goals, whether they persist without interest, and whether and how they try to create interest. We first present the self-regulation of motivation model and then review research illustrating how the consideration of individual differences at different points in the process allows a better understanding of variability in people's choices, efforts, and persistence over time.

The street as an area of human exposure in an earthquake aftermath: the case of Lorca, Spain, 2011

NASA Astrophysics Data System (ADS)

Bertran Rojo, Marc; Beck, Elise; Lutoff, Céline

2017-04-01

The earthquake which struck the city of Lorca, Spain, on 11 May 2011 killed 9 people, injured over 300 and caused considerable damage, including one collapsed building. Streets near buildings were the main danger areas for people. This article proposes an dynamic ad hoc spatio-temporal method for studying individual evacuation after an earthquake. Its application to the Lorca case shows the spatial and temporal variability of individual exposure levels in the street during the hours following the shock. As yet little studied, human exposure deserves more attention, particularly in zones of moderate seismicity like the Euro-Mediterranean area. The results of this study could be helpful for enhancing the evacuation planning after an earthquake, stressing the specific dangers in the street.

MS in self-identified Hispanic/Latino individuals living in the US

PubMed Central

Amezcua, Lilyana; Oksenberg, Jorge R; McCauley, Jacob L

2017-01-01

Self-identified Hispanic/Latino individuals living with multiple sclerosis (MS) in the continental United States (US) are a diverse group that represents different cultural and ancestral backgrounds. A marked variability in the way MS affects various subgroups of Hispanics in the US has been observed. We reviewed and synthesized available data about MS in Hispanics in the US. There are likely a host of multifactorial elements contributing to these observations that could be explained by genetic, environmental, and social underpinnings. Barriers to adequate MS care in Hispanics are likely to include delivery of culturally competent care and social and economic disadvantages. Considerable efforts, including the formation of a national consortium known as the Alliance for Research in Hispanic Multiple Sclerosis (ARHMS), are underway to help further explore these various factors. PMID:28979795

The effect of working memory capacity limitations on the intuitive assessment of correlation: amplification, attenuation, or both?

PubMed

Cahan, Sorel; Mor, Yaniv

2007-03-01

This article challenges Yaakov Kareev's (1995a, 2000) argument regarding the positive bias of intuitive correlation estimates due to working memory capacity limitations and its adaptive value. The authors show that, under narrow window theory's primacy effect assumption, there is a considerable between-individual variability of the effects of capacity limitations on the intuitive assessment of correlation, in terms of both sign and magnitude: Limited capacity acts as an amplifier for some individuals and as a silencer for others. Furthermore, the average amount of attenuation exceeds the average amount of amplification, and the more so, the smaller the capacity. Implications regarding the applicability and contribution of the bias notion in this context and the evaluation of the adaptive value of capacity limitations are discussed.

STEM Education: An Incongruous Approach A Proposed Reform Model for a Large Suburban High School

NASA Astrophysics Data System (ADS)

Hughes, Patricia A.

It is unknown how the school can best influence the variables that determine pursuance of science study and career choice to bring about greater opportunity to learn challenging science curriculum for all students and promote Science Technology Engineering and Mathematics (STEM) education. Student decisions regarding the type of science class to elect in early secondary school years can impact their progression and academic success in subsequent rigorous and challenging offerings. Parents, counselors, peers, gender, socio-economic status and individual experience in previous coursework are variables of consideration. The purpose of this study is to examine these variables in a large suburban New Jersey School District aligned to STEM and Advanced Placement level course choice by students. Information regarding the influence of the variables can lead to a reform of the approach toward STEM education currently in place. The study will include a historical reflection of the approach to curriculum revision in the district. Increasing student enrollment in science courses beyond the required number stipulated for high school completion will open opportunities for entrance into STEM related careers or continued post secondary science study.

Stand, species, and individual traits impact transpiration in historically disturbed forests.

NASA Astrophysics Data System (ADS)

Blakely, B.; Rocha, A. V.; McLachlan, J. S.

2017-12-01

Historic logging disturbances have changed the structure and species composition of most Northern temperate forests. These changes impact the process of transpiration - which in turn impacts canopy surface temperature - but the links among structure, composition, and transpiration remain unclear. For this reason, ecosystem models typically use simplified structure and composition to simulate the impact of disturbances on forest transpiration. However, such simplifications ignore real variability among stands, species, and individual trees that may strongly influence transpiration across spatial and temporal scales. To capture this variability, we monitored transpiration in 48 individual trees of multiple species in both undisturbed (400+ yr) and historically logged (80 - 120 yr) forests. Using modern and historic forest surveys, we upscaled our observations to stand and regional scales to identify the key changes impacting transpiration. We extended these inferences by establishing a relationship between transpiration and measured surface temperature, linking disturbance-induced changes in structure and composition to local and regional climate. Despite greater potential evapotranspiration and basal area, undisturbed forest transpired less than disturbed (logged) forest. Transpiration was a strong predictor of surface temperature, and the canopy surface was warmer in undisturbed forest. Transpiration differences among disturbed and undisturbed forests resulted from (1) lesser transpiration and dampened seasonality in evergreen species (2) greater transpiration in younger individuals within a species, and (3) strong transpiration by large individuals. When transpiration was scaled to the stand or regional level in a simplified manner (e.g. a single transpiration rate for all deciduous individuals), the resulting estimates differed markedly from the original. Stand- species- and individual-level traits are therefore essential for understanding how transpiration and surface temperature respond to disturbance. Without consideration of such traits, current ecosystem models may struggle to capture the true impact of logging disturbances on forest transpiration.

Consideration of future safety consequences: a new predictor of employee safety.

PubMed

Probst, Tahira M; Graso, Maja; Estrada, Armando X; Greer, Sarah

2013-06-01

Compliance with safety behaviors is often associated with longer term benefits, but may require some short-term sacrifices. This study examines the extent to which consideration of future safety consequences (CFSC) predicts employee safety outcomes. Two field studies were conducted to evaluate the reliability and validity of the newly developed Consideration of Future Safety Consequences (CFSC) scale. Surveys containing the CFSC scale and other measures of safety attitudes, behaviors, and outcomes were administered during working hours to a sample of 128 pulp and paper mill employees; after revising the CFSC scale based on these initial results, follow-up survey data were collected in a second sample of 212 copper miners. In Study I, CFSC was predictive of employee safety knowledge and motivation, compliance, safety citizenship behaviors, accident reporting attitudes and behaviors, and workplace injuries - even after accounting for conscientiousness and demographic variables. Moreover, the effects of CFSC on the variables generally appear to be direct, as opposed to mediated by safety knowledge or motivation. These findings were largely replicated in Study II. CFSC appears to be an important personality construct that may predict those individuals who are more likely to comply with safety rules and have more positive safety outcomes. Future research should examine the longitudinal stability of CFSC to determine the extent to which this construct is a stable trait, rather than a safety attitude amenable to change over time or following an intervention. Copyright © 2013 Elsevier Ltd. All rights reserved.

Design considerations and rationale of a multi-center trial to sustain weight loss: the Weight Loss Maintenance Trial.

PubMed

Brantley, Phillip; Appel, Lawrence; Hollis, Jack; Stevens, Victor; Ard, Jamy; Champagne, Catherine; Elmer, Patricia; Harsha, David; Myers, Valerie; Proschan, Michael; William, Vollmer; Svetkey, Laura

2008-01-01

The Weight Loss Maintenance Trial (WLM) is a multi-center, randomized, controlled trial that compares the effects of two 30-month maintenance interventions, i.e., Personal Contact (PC) and Interactive Technology (IT) to a self-directed usual care control group (SD), in overweight or obese individuals who are at high risk for cardiovascular disease. This paper provides an overview of the design and methods, and design considerations and lessons learned from this trial. All participants received a 6-month behavioral weight loss program consisting of weekly group sessions. Participants who lost 4 kg were randomized to one of three conditions (PC, IT, or SD). The PC condition provided monthly contacts with an interventionist primarily via telephone and quarterly face-to-face visits. The IT condition provided frequent, individualized contact through a tailored, website system. Both the PC and IT maintenance programs encouraged the DASH dietary pattern and employed theory-based behavioral techniques to promote maintenance. Design considerations included choice of study population, frequency and type of intervention visits, and choice of primary outcome. Overweight or obese persons with CVD risk factors were studied. The pros and cons of studying this population while excluding others are presented. We studied intervention contact strategies that made fewer demands on participant time and travel, while providing frequent opportunities for interaction. The primary outcome variable for the trial was change in weight from randomization to end of follow-up (30 months). Limits to generalizability are discussed. Individuals in need of weight loss strategies may have been excluded due to barriers associated with internet use. Other participants may have been excluded secondary to a comorbid condition. This paper highlights the design and methods of WLM and informs readers of discussions of critical issues and lessons learned from the trial.

Some considerations concerning the challenge of incorporating social variables into epidemiological models of infectious disease transmission.

PubMed

Barnett, Tony; Fournié, Guillaume; Gupta, Sunetra; Seeley, Janet

2015-01-01

Incorporation of 'social' variables into epidemiological models remains a challenge. Too much detail and models cease to be useful; too little and the very notion of infection - a highly social process in human populations - may be considered with little reference to the social. The French sociologist Émile Durkheim proposed that the scientific study of society required identification and study of 'social currents'. Such 'currents' are what we might today describe as 'emergent properties', specifiable variables appertaining to individuals and groups, which represent the perspectives of social actors as they experience the environment in which they live their lives. Here we review the ways in which one particular emergent property, hope, relevant to a range of epidemiological situations, might be used in epidemiological modelling of infectious diseases in human populations. We also indicate how such an approach might be extended to include a range of other potential emergent properties to represent complex social and economic processes bearing on infectious disease transmission.

Individual Differences in the Alignment of Structural and Functional Markers of the V5/MT Complex in Primates

PubMed Central

Large, I.; Bridge, H.; Ahmed, B.; Clare, S.; Kolasinski, J.; Lam, W. W.; Miller, K. L.; Dyrby, T. B.; Parker, A. J.; Smith, J. E. T.; Daubney, G.; Sallet, J.; Bell, A. H.; Krug, K.

2016-01-01

Extrastriate visual area V5/MT in primates is defined both structurally by myeloarchitecture and functionally by distinct responses to visual motion. Myelination is directly identifiable from postmortem histology but also indirectly by image contrast with structural magnetic resonance imaging (sMRI). First, we compared the identification of V5/MT using both sMRI and histology in Rhesus macaques. A section-by-section comparison of histological slices with in vivo and postmortem sMRI for the same block of cortical tissue showed precise correspondence in localizing heavy myelination for V5/MT and neighboring MST. Thus, sMRI in macaques accurately locates histologically defined myelin within areas known to be motion selective. Second, we investigated the functionally homologous human motion complex (hMT+) using high-resolution in vivo imaging. Humans showed considerable intersubject variability in hMT+ location, when defined with myelin-weighted sMRI signals to reveal structure. When comparing sMRI markers to functional MRI in response to moving stimuli, a region of high myelin signal was generally located within the hMT+ complex. However, there were considerable differences in the alignment of structural and functional markers between individuals. Our results suggest that variation in area identification for hMT+ based on structural and functional markers reflects individual differences in human regional brain architecture. PMID:27371764

Theoretical and Methodological Considerations in Cross-Generational Research on Parenting and Child Aggressive Behavior

PubMed Central

Dubow, Eric F.; Huesmann, L. Rowell; Boxer, Paul

2015-01-01

The four studies in this special issue represent important advances in research on the intergenerational transmission of aggressive behavior. In this commentary, we review the key features and findings of these studies, as well as our own cross-generational study of aggression, the Columbia County Longitudinal Study. Next, we consider important theoretical issues (e.g., defining and operationalizing “aggression” and “parenting”; assessing reciprocal effects of parenting and child aggression; identifying the ages at which aggression should be assessed across generations; broadening the investigation of contextual and individual factors). We then discuss several methodological issues (e.g., determining the most informative measurement intervals for assessing prospective effects; sampling considerations; measuring potential moderating and mediating variables that might explain cross-generational continuities and discontinuities in parenting and aggression). Finally, we raise implications of cross-generational research for designing interventions targeting the reduction and prevention of child aggression. PMID:12735400

When love hurts: assessing the intersectionality of ethnicity, socio-economic status, parental connectedness, child abuse, and gender attitudes in juvenile violent delinquency.

PubMed

Lahlah, Esmah; Lens, Kim M E; Bogaerts, Stefan; van der Knaap, Leontien M

2013-11-01

Researchers have not yet reached agreement about the validity of several competing explanations that seek to explain ethnic differences in juvenile violent offending. Ethnicity cannot solely explain why boys with an ethnic minority background commit more (violent) crimes. By assessing the intersectionality of structural, cultural and individual considerations, both the independent effects as well as the interplay between different factors can be examined. This study shows that aforementioned factors cumulatively play a role in severe violent offending, with parental connectedness and child abuse having the strongest associations. However, since most variables interact and ethnicity is associated with those specific factors, a conclusion to be drawn is that ethnicity may be relevant as an additional variable predicting severe violent offending although indirectly. Copyright © 2013 Elsevier Ltd. All rights reserved.

The influence of acoustical and non-acoustical factors on short-term annoyance due to aircraft noise in the field - The COSMA study.

PubMed

Bartels, Susanne; Márki, Ferenc; Müller, Uwe

2015-12-15

Air traffic has increased for the past decades and is forecasted to continue to grow. Noise due to current airport operations can impair the physical and psychological well-being of airport residents. The field study investigated aircraft noise-induced short-term (i.e., within hourly intervals) annoyance in local residents near a busy airport. We aimed at examining the contribution of acoustical and non-acoustical factors to the annoyance rating. Across four days from getting up till going to bed, 55 residents near Cologne/Bonn Airport (M=46years, SD=14years, 34 female) rated their annoyance due to aircraft noise at hourly intervals. For each participant and each hour, 26 noise metrics from outdoor measurements and further 6 individualized metrics that took into account the sound attenuation due to each person's whereabouts in and around their homes were obtained. Non-acoustical variables were differentiated into situational factors (time of day, performed activity during past hour, day of the week) and personal factors (e.g., sensitivity to noise, attitudes, domestic noise insulation). Generalized Estimation Equations were applied for the development of a prediction model for annoyance. Acoustical factors explained only a small proportion (13.7%) of the variance in the annoyance ratings. The number of fly-overs predicted annoyance better than did equivalent and maximum sound pressure levels. The proportion of explained variance in annoyance rose considerably (to 27.6%) when individualized noise metrics as well as situational and personal variables were included in the prediction model. Consideration of noise metrics related to the number of fly-overs and individual adjustment of noise metrics can improve the prediction of short-term annoyance compared to models using equivalent outdoor levels only. Non-acoustical factors have remarkable impact not only on long-term annoyance as shown before but also on short-term annoyance judged in the home environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Response heterogeneity: Challenges for personalised medicine and big data approaches in psychiatry and chronic pain.

PubMed

Norbury, Agnes; Seymour, Ben

2018-01-01

Response rates to available treatments for psychological and chronic pain disorders are poor, and there is a substantial burden of suffering and disability for patients, who often cycle through several rounds of ineffective treatment. As individuals presenting to the clinic with symptoms of these disorders are likely to be heterogeneous, there is considerable interest in the possibility that different constellations of signs could be used to identify subgroups of patients that might preferentially benefit from particular kinds of treatment. To this end, there has been a recent focus on the application of machine learning methods to attempt to identify sets of predictor variables (demographic, genetic, etc.) that could be used to target individuals towards treatments that are more likely to work for them in the first instance. Importantly, the training of such models generally relies on datasets where groups of individual predictor variables are labelled with a binary outcome category - usually 'responder' or 'non-responder' (to a particular treatment). However, as previously highlighted in other areas of medicine, there is a basic statistical problem in classifying individuals as 'responding' to a particular treatment on the basis of data from conventional randomized controlled trials. Specifically, insufficient information on the partition of variance components in individual symptom changes mean that it is inappropriate to consider data from the active treatment arm alone in this way. This may be particularly problematic in the case of psychiatric and chronic pain symptom data, where both within-subject variability and measurement error are likely to be high. Here, we outline some possible solutions to this problem in terms of dataset design and machine learning methodology, and conclude that it is important to carefully consider the kind of inferences that particular training data are able to afford, especially in arenas where the potential clinical benefit is so large.

Using water to cool cattle: behavioral and physiological changes associated with voluntary use of cow showers.

PubMed

Legrand, A; Schütz, K E; Tucker, C B

2011-07-01

Water is commonly used to cool cattle in summer either at milking or over the feed bunk, but little research has examined how dairy cows voluntarily use water separate from these locations. The objectives were to describe how and when dairy cattle voluntarily used an overhead water source separate from other resources, such as feed, and how use of this water affected behavioral and physiological indicators of heat stress. Half of the 24 nonlactating cattle tested had access to a "cow shower" composed of 2 shower heads activated by a pressure-sensitive floor. All animals were individually housed to prevent competition for access to the shower. Over 5 d in summer (air temperature=25.3±3.3°C, mean ± standard deviation), cattle spent 3.0±2.1 h/24h in the shower, but considerable variability existed between animals (individual daily values ranged from 0.0 to 8.2 h/24h). A portion of this variation can be explained by weather; shower use increased by 0.3h for every 1°C increase in ambient temperature. Cows preferentially used the shower during the daytime, with 89±12% of the time spent in the shower between 1000 and 1900 h. Respiration rate and skin temperature did not differ between treatments [53 vs. 61 breaths/min and 35.0 vs. 35.4°C in shower and control cows, respectively; standard error of the difference (SED)=5.6 breaths/min and 0.49°C]. In contrast, body temperature of cows provided with a shower was 0.2°C lower than control cows in the evening (i.e., 1800 to 2100h; SED=0.11°C). Cows with access to a shower spent half as much time near the water trough than control animals, and this pattern became more pronounced as the temperature-humidity index increased. In addition, cattle showed other behavioral changes to increasing heat load; they spent less time lying when heat load index increased, but the time spent lying, feeding, and standing without feeding did not differ between treatments. Cows had higher respiration rate, skin temperature, and body temperature as heat load index increased, regardless of treatment. These data suggest that cattle, when given the opportunity, will make considerable use of a shower to reduce heat load, but that individuals are highly variable in their use of this resource. The variability between cows indicates that the behavioral response to water is likely an important, but poorly understood, consideration in the design of sprinkler systems used for summer cooling. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Clonal structure and variable fertilization success in Florida Keys broadcast-spawning corals

NASA Astrophysics Data System (ADS)

Miller, M. W.; Baums, I. B.; Pausch, R. E.; Bright, A. J.; Cameron, C. M.; Williams, D. E.; Moffitt, Z. J.; Woodley, C. M.

2018-03-01

Keystone reef-building corals in the Caribbean are predominantly self-incompatible broadcast spawners and a majority are threatened due to both acute adult mortality and poor recruitment. As population densities decline, concerns about fertilization limitation and effective population size in these species increase and would be further exacerbated by either high clonality or gametic incompatibility of parental genotypes. This study begins to address these concerns for two Caribbean broadcasting species by characterizing clonal structure and quantifying experimental pairwise fertilization success. Orbicella faveolata showed surprisingly high and contrasting levels of clonality between two sampled sites; Acropora palmata was previously known to be highly clonal. Individual pairwise crosses of synchronously spawning genotypes of each species were conducted by combining aliquots of gamete bundles immediately after spawning, and showed high and significant variability in fertilization success. Over half of the individual crosses of O. faveolata and about one-third of A. palmata crosses yielded ≤ 40% fertilization. Total sperm concentration was quantified in only a subset of O. faveolata crosses (range of 1-6 × 107 mL-1), but showed no correlation with fertilization success. We interpret that both parental incompatibility and individual genotypes with low-quality gametes are likely to have contributed to the variable fertilization observed with important implications for conservation. Differential fertilization success implies effective population size may be considerably smaller than hoped and population enhancement efforts need to incorporate many more parental genotypes at the patch scale to ensure successful larval production than indicated by estimates based simply on preserving levels of standing genetic diversity.

Variability in adherence to clinical practice guidelines and recommendations in COPD outpatients: a multi-level, cross-sectional analysis of the EPOCONSUL study.

PubMed

Calle Rubio, Myriam; López-Campos, José Luis; Soler-Cataluña, Juan J; Alcázar Navarrete, Bernardino; Soriano, Joan B; Rodríguez González-Moro, José Miguel; Fuentes Ferrer, Manuel E; Rodríguez Hermosa, Juan Luis

2017-12-02

Clinical audits have reported considerable variability in COPD medical care and frequent inconsistencies with recommendations. The objectives of this study were to identify factors associated with a better adherence to clinical practice guidelines and to explore determinants of this variability at the the hospital level. EPOCONSUL is a Spanish nationwide clinical audit that evaluates the outpatient management of COPD. Multilevel logistic regression with two levels was performed to assess the relationships between individual and disease-related factors, as well as hospital characteristics. A total of 4508 clinical records of COPD patients from 59 Spanish hospitals were evaluated. High variability was observed among hospitals in terms of medical care. Some of the patient's characteristics (airflow obstruction, degree of dyspnea, exacerbation risk, presence of comorbidities), the hospital factors (size and respiratory nurses available) and treatment at a specialized COPD outpatient clinic were identified as factors associated with a better adherence to recommendations, although this only explains a small proportion of the total variance. To be treated at a specialized COPD outpatient clinic and some intrinsic patient characteristics were factors associated with a better adherence to guideline recommendations, although these variables were only explaining part of the high variability observed among hospitals in terms of COPD medical care.

The association of external knee adduction moment with biomechanical variables in osteoarthritis: a systematic review.

PubMed

Foroughi, Nasim; Smith, Richard; Vanwanseele, Benedicte

2009-10-01

Osteoarthritis (OA) is a musculoskeletal disorder primarily affecting the older population and resulting in chronic pain and disability. Biomechanical variables, associated with OA severity such as external knee adduction moment (KAM) and joint malalignment, may affect the disease process by altering the bone-on-bone forces during gait. To investigate the association between biomechanical variables and KAM in knee OA. A systematic search for published studies' titles and abstracts was performed on Ovid Medline, Cumulative index to Nursing and Allied Health, PREMEDLINE, EBM reviews and SPORTDiscus. Fourteen studies met the inclusion criteria and were considered for the review. The magnitude and time course of KAM during gait appeared to be consistent across laboratories and computational methods. Only two of the included studies that compared patients with OA to a control group reported a higher peak KAM for the OA group. Knee adduction moment increased with OA severity and was directly proportional to varus malalignment. Classifying the patients on the basis of disease severity decreased the group variability, permitting the differences to be more detectable. Biomechanical variables such as varus malalignment are associated with KAM and therefore may affect the disease process. These variables should be taken into considerations when developing therapeutic interventions for individuals suffering from knee OA.

Risk-adjusted Outcomes of Clinically Relevant Pancreatic Fistula Following Pancreatoduodenectomy: A Model for Performance Evaluation.

PubMed

McMillan, Matthew T; Soi, Sameer; Asbun, Horacio J; Ball, Chad G; Bassi, Claudio; Beane, Joal D; Behrman, Stephen W; Berger, Adam C; Bloomston, Mark; Callery, Mark P; Christein, John D; Dixon, Elijah; Drebin, Jeffrey A; Castillo, Carlos Fernandez-Del; Fisher, William E; Fong, Zhi Ven; House, Michael G; Hughes, Steven J; Kent, Tara S; Kunstman, John W; Malleo, Giuseppe; Miller, Benjamin C; Salem, Ronald R; Soares, Kevin; Valero, Vicente; Wolfgang, Christopher L; Vollmer, Charles M

2016-08-01

To evaluate surgical performance in pancreatoduodenectomy using clinically relevant postoperative pancreatic fistula (CR-POPF) occurrence as a quality indicator. Accurate assessment of surgeon and institutional performance requires (1) standardized definitions for the outcome of interest and (2) a comprehensive risk-adjustment process to control for differences in patient risk. This multinational, retrospective study of 4301 pancreatoduodenectomies involved 55 surgeons at 15 institutions. Risk for CR-POPF was assessed using the previously validated Fistula Risk Score, and pancreatic fistulas were stratified by International Study Group criteria. CR-POPF variability was evaluated and hierarchical regression analysis assessed individual surgeon and institutional performance. There was considerable variability in both CR-POPF risk and occurrence. Factors increasing the risk for CR-POPF development included increasing Fistula Risk Score (odds ratio 1.49 per point, P < 0.00001) and octreotide (odds ratio 3.30, P < 0.00001). When adjusting for risk, performance outliers were identified at the surgeon and institutional levels. Of the top 10 surgeons (≥15 cases) for nonrisk-adjusted performance, only 6 remained in this high-performing category following risk adjustment. This analysis of pancreatic fistulas following pancreatoduodenectomy demonstrates considerable variability in both the risk and occurrence of CR-POPF among surgeons and institutions. Disparities in patient risk between providers reinforce the need for comprehensive, risk-adjusted modeling when assessing performance based on procedure-specific complications. Furthermore, beyond inherent patient risk factors, surgical decision-making influences fistula outcomes.

Imperfect physician assistant and physical therapist admissions processes in the United States

PubMed Central

2014-01-01

We compared and contrasted physician assistant and physical therapy profession admissions processes based on the similar number of accredited programs in the United States and the co-existence of many programs in the same school of health professions, because both professions conduct similar centralized application procedures administered by the same organization. Many studies are critical of the fallibility and inadequate scientific rigor of the high-stakes nature of health professions admissions decisions, yet typical admission processes remain very similar. Cognitive variables, most notably undergraduate grade point averages, have been shown to be the best predictors of academic achievement in the health professions. The variability of non-cognitive attributes assessed and the methods used to measure them have come under increasing scrutiny in the literature. The variance in health professions students’ performance in the classroom and on certifying examinations remains unexplained, and cognitive considerations vary considerably between and among programs that describe them. One uncertainty resulting from this review is whether or not desired candidate attributes highly sought after by individual programs are more student-centered or graduate-centered. Based on the findings from the literature, we suggest that student success in the classroom versus the clinic is based on a different set of variables. Given the range of positions and general lack of reliability and validity in studies of non-cognitive admissions attributes, we think that health professions admissions processes remain imperfect works in progress. PMID:24810020

Systems effects on family planning innovativeness.

PubMed

Lee, S B

1983-12-01

Data from Korea were used to explore the importance of community level variables in explaining family planning adoption at the individual level. An open system concept was applied, assuming that individual family planning behavior is influenced by both environmental and individual factors. The environmental factors were measured at the village level and designated as community characteristics. The dimension of communication network variables was introduced. Each individual was characterized in terms of the degree of her involvement in family planning communication with others in her village. It was assumed that the nature of the communication network linking individuals with each other effects family planning adoption at the individual level. Specific objectives were to determine 1) the relative importance of the specific independent variables in explaining family planning adoption and 2) the relative importance of the community level variables in comparison with the individual level variables in explaining family planning adoption at the individual level. The data were originally gathered in a 1973 research project on Korea's mothers' clubs. 1047 respondents were interviewed, comprising all married women in 25 sample villages having mothers' clubs. The dependent variable was family planning adoption behavior, defined as current use of any of the modern methods of family planning. The independent variables were defined at 3 levels: individual, community, and at a level intermediate between them involving communication links between individuals. More of the individual level independent variables were significantly correlated with the dependent variables than the community level variables. Among those variables with statistically significant correlations, the correlation coefficients were consistently higher for the individual level than for the community level variables. More of the variance in the dependent variable was explained by individual level than by community level variables. Community level variables accounted for only about 2.5% of the total variance in the dependent variable, in marked contrast to the result showing individual level variables accounting for as much as 19% of the total variance. When both individual and community level variables were entered into a multiple correlation analysis, a multiple correlation coefficient of .4714 was obtained together they explained about 20% of the total variance. The 2 communication network variables--connectedness and integrativeness--were correlated with the dependent variable at much higher levels than most of the individual or community level variables. Connectedness accounted for the greatest amount of the total variance. The communication network variables as a group explained as much of the total variance in the dependent variable as the individual level variables and greatly more that the community level variables.

Visual Predictive Check in Models with Time-Varying Input Function.

PubMed

Largajolli, Anna; Bertoldo, Alessandra; Campioni, Marco; Cobelli, Claudio

2015-11-01

The nonlinear mixed effects models are commonly used modeling techniques in the pharmaceutical research as they enable the characterization of the individual profiles together with the population to which the individuals belong. To ensure a correct use of them is fundamental to provide powerful diagnostic tools that are able to evaluate the predictive performance of the models. The visual predictive check (VPC) is a commonly used tool that helps the user to check by visual inspection if the model is able to reproduce the variability and the main trend of the observed data. However, the simulation from the model is not always trivial, for example, when using models with time-varying input function (IF). In this class of models, there is a potential mismatch between each set of simulated parameters and the associated individual IF which can cause an incorrect profile simulation. We introduce a refinement of the VPC by taking in consideration a correlation term (the Mahalanobis or normalized Euclidean distance) that helps the association of the correct IF with the individual set of simulated parameters. We investigate and compare its performance with the standard VPC in models of the glucose and insulin system applied on real and simulated data and in a simulated pharmacokinetic/pharmacodynamic (PK/PD) example. The newly proposed VPC performance appears to be better with respect to the standard VPC especially for the models with big variability in the IF where the probability of simulating incorrect profiles is higher.

Kinship and altruism: a cross-cultural experimental study.

PubMed

Madsen, Elainie A; Tunney, Richard J; Fieldman, George; Plotkin, Henry C; Dunbar, Robin I M; Richardson, Jean-Marie; McFarland, David

2007-05-01

Humans are characterized by an unusual level of prosociality. Despite this, considerable indirect evidence suggests that biological kinship plays an important role in altruistic behaviour. All previous reports of the influence of kin selection on human altruism have, however, used correlational (rather than experimental) designs, or imposed only a hypothetical or negligible time cost on participants. Since these research designs fail either to control for confounding variables or to meet the criteria required as a test of Hamilton's rule for kin selection (that the altruist pays a true cost), they fail to establish unequivocally whether kin selection plays a role. We show that individuals from two different cultures behave in accordance with Hamilton's rule by acting more altruistically (imposing a higher physical cost upon themselves) towards more closely related individuals. Three possible sources of confound were ruled out: generational effects, sexual attraction and reciprocity. Performance on the task however did not exhibit a perfect linear relationship with relatedness, which might reflect either the intrusion of other variables (e.g. cultural differences in the way kinship is costed) or that our behavioural measure is insufficiently sensitive to fine-tuned differences in the way individuals view their social world. These findings provide the first unequivocal experimental evidence that kinship plays a role in moderating altruistic behaviour. Kinship thus represents a baseline against which individuals pitch other criteria (including reciprocity, prosociality, obligation and a moral sense) when deciding how to behave towards others.

Individual set-point and gain of emmetropization in chickens.

PubMed

Tepelus, Tudor Cosmin; Schaeffel, Frank

2010-01-01

During the developmental process of emmetropization evidence shows that visual feedback guides the eye as it approaches a refractive state close to zero, or slightly hyperopic. How this "set-point" is internally defined, in the presence of continuous shifts of the focal plane with different viewing distances and accommodation, remains unclear. Minimizing defocus blur over time should produce similar end-point refractions in different individuals. However, we found that individual chickens display considerable variability in their set-point refractive states, despite that they all had the same visual experience. This variability is not random since the refractions in both eyes were highly correlated - even though it is known that they can emmetropize independently. Furthermore, if chicks underwent a period of experimentally induced ametropia, they returned to their individual set-point refractions during recovery (correlation of the refractions before treatment versus after recovery: n=19 chicks, 38 eyes, left eyes: slope 1.01, R=0.860; right eyes: slope 0.85, R=0.610, p<0.001, linear regression). Also, the induced deprivation myopia was correlated in both eyes (n=18 chicks, 36 eyes, p<0.01, orthogonal regression). If chicks were treated with spectacle lenses, the compensatory changes in refraction were, on average, appropriate but individual chicks displayed variable responses. Again, the refractions of both eyes remained correlated (negative lenses, n=18 chicks, 36 eyes, slope 0.89, R=0.504, p<0.01, positive lenses: n=21 chicks, 42 eyes, slope 1.14, R=0.791, p<0.001). The amount of deprivation myopia that developed in two successive treatment cycles, with an intermittent period of recovery, was not correlated; only vitreous chamber growth was almost significantly correlated in both cycles (n=7 chicks, 14 eyes; p<0.05). The amounts of ametropia and vitreous chamber changes induced in two successive cycles of treatment, first with lenses and then with diffusers, were also not correlated, suggesting that the "gains of lens compensation" are different from those in deprivation myopia. In summary, (1) there appears to be an endogenous, possibly genetic, definition of the set-point of emmetropization in each individual, which is similar in both eyes, (2) visual conditions that induce ametropia produce variable changes in refractions, with high correlations between both eyes, (3) overall, the "gain of emmetropization" appears only weakly controlled by endogenous factors.

FOXP2 variants in 14 individuals with developmental speech and language disorders broaden the mutational and clinical spectrum.

PubMed

Reuter, Miriam S; Riess, Angelika; Moog, Ute; Briggs, Tracy A; Chandler, Kate E; Rauch, Anita; Stampfer, Miriam; Steindl, Katharina; Gläser, Dieter; Joset, Pascal; Krumbiegel, Mandy; Rabe, Harald; Schulte-Mattler, Uta; Bauer, Peter; Beck-Wödl, Stefanie; Kohlhase, Jürgen; Reis, André; Zweier, Christiane

2017-01-01

Disruptions of the FOXP2 gene, encoding a forkhead transcription factor, are the first known monogenic cause of a speech and language disorder. So far, mainly chromosomal rearrangements such as translocations or larger deletions affecting FOXP2 have been reported. Intragenic deletions or convincingly pathogenic point mutations in FOXP2 have up to date only been reported in three families. We thus aimed at a further characterisation of the mutational and clinical spectrum. Chromosomal microarray testing, trio exome sequencing, multigene panel sequencing and targeted sequencing of FOXP2 were performed in individuals with variable developmental disorders, and speech and language deficits. We identified four different truncating mutations, two novel missense mutations within the forkhead domain and an intragenic deletion in FOXP2 in 14 individuals from eight unrelated families. Mutations occurred de novo in four families and were inherited from an affected parent in the other four. All index patients presented with various manifestations of language and speech impairment. Apart from two individuals with normal onset of speech, age of first words was between 4 and 7 years. Articulation difficulties such as slurred speech, dyspraxia, stuttering and poor pronunciation were frequently noted. Motor development was normal or only mildly delayed. Mild cognitive impairment was reported for most individuals. By identifying intragenic deletions or mutations in 14 individuals from eight unrelated families with variable developmental delay/cognitive impairment and speech and language deficits, we considerably broaden the mutational and clinical spectrum associated with aberrations in FOXP2. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Modeling individual exposures to ambient PM2.5 in the diabetes and the environment panel study (DEPS).

PubMed

Breen, Michael; Xu, Yadong; Schneider, Alexandra; Williams, Ronald; Devlin, Robert

2018-06-01

Air pollution epidemiology studies of ambient fine particulate matter (PM 2.5 ) often use outdoor concentrations as exposure surrogates, which can induce exposure error. The goal of this study was to improve ambient PM 2.5 exposure assessments for a repeated measurements study with 22 diabetic individuals in central North Carolina called the Diabetes and Environment Panel Study (DEPS) by applying the Exposure Model for Individuals (EMI), which predicts five tiers of individual-level exposure metrics for ambient PM 2.5 using outdoor concentrations, questionnaires, weather, and time-location information. Using EMI, we linked a mechanistic air exchange rate (AER) model to a mass-balance PM 2.5 infiltration model to predict residential AER (Tier 1), infiltration factors (F inf_home , Tier 2), indoor concentrations (C in , Tier 3), personal exposure factors (F pex , Tier 4), and personal exposures (E, Tier 5) for ambient PM 2.5 . We applied EMI to predict daily PM 2.5 exposure metrics (Tiers 1-5) for 174 participant-days across the 13 months of DEPS. Individual model predictions were compared to a subset of daily measurements of F pex and E (Tiers 4-5) from the DEPS participants. Model-predicted F pex and E corresponded well to daily measurements with a median difference of 14% and 23%; respectively. Daily model predictions for all 174 days showed considerable temporal and house-to-house variability of AER, F inf_home , and C in (Tiers 1-3), and person-to-person variability of F pex and E (Tiers 4-5). Our study demonstrates the capability of predicting individual-level ambient PM 2.5 exposure metrics for an epidemiological study, in support of improving risk estimation. Copyright © 2018. Published by Elsevier B.V.

Optimization of agricultural field workability predictions for improved risk management

USDA-ARS?s Scientific Manuscript database

Risks introduced by weather variability are key considerations in agricultural production. The sensitivity of agriculture to weather variability is of special concern in the face of climate change. In particular, the availability of workable days is an important consideration in agricultural practic...

Drug approval processes in Australian Paediatric Hospitals.

PubMed

Sinha, Y K; Craig, J C; Barclay, P; Taitz, J; South, M; Coulthard, K; Pearson, C; Erickson, S; Brien, J E

2010-09-01

To describe and evaluate the decision-making processes for drug approval in Australian paediatric hospitals. Multicentre descriptive study involving face-to-face interviews of drug and therapeutics committee chairs and secretaries, review of committee documents and drug submissions for all Australian paediatric hospital drug and therapeutics committees over a 1-year period. All eight paediatric hospitals in Australia. Eight committee chairs and seven secretaries or delegates. Total drug expenditure, number of formulary submissions, individual-patient use approvals and approval rates for each hospital from 1 July 2006 to 30 June 2007, stratified by therapeutic class. Qualitative description of the approval processes. Total drug expenditure varied from $A1.7 million (US$1.5 million) to $A11.1 million (US$9.8 million) per hospital. The number of formulary submissions also varied, from 7 to 21, but approval rate was high (76%-100%) and not significantly different among hospitals (p=0.17). Several committees approved identical submissions for five drugs. The number of individual-patient use applications varied considerably, ranging from 10 to 456 per hospital. Where estimable, individual-patient use approval was 76%-100% and variable (p=0.03). Quality of evidence relating to safety and efficacy of drugs being considered was regarded as the most important factors influencing decision making, with the cost less important. Most committees had poor infrastructural support for approval processes. No committee formally included a pharmaco-economic evaluation. Most drug submissions in tertiary paediatric hospitals are approved; however, workload, drug expenditure and individual-patient use schemes vary considerably. Duplication of effort occurs, and few committees are resourced sufficiently given their terms of reference.

Unknown Safety and Efficacy of Smartphone Bolus Calculator Apps Puts Patients at Risk for Severe Adverse Outcomes.

PubMed

Hirsch, Irl B; Parkin, Christopher G

2016-07-01

Manual calculation of bolus insulin dosages can be challenging for individuals treated with multiple daily insulin injections (MDI) therapy. Automated bolus calculator capability has recently been made available via enhanced blood glucose meters and smartphone apps. Use of this technology has been shown to improve glycemic control and reduce glycemic variability without changing hypoglycemia; however, the clinical utility of app-based bolus calculators has not been demonstrated. Moreover, recent evidence challenges the safety and efficacy of these smartphone apps. Although the ability to automatically calculate bolus insulin dosages addresses a critical need of MDI-treated individuals, this technology raises concerns about efficacy of treatment and the protection of patient safety. This article discusses key issues and considerations associated with automated bolus calculator use. © 2016 Diabetes Technology Society.

[Factors conditioning primary care services utilization. Empirical evidence and methodological inconsistencies].

PubMed

Sáez, M

2003-01-01

In Spain, the degree and characteristics of primary care services utilization have been the subject of analysis since at least the 1980s. One of the main reasons for this interest is to assess the extent to which utilization matches primary care needs. In fact, the provision of an adequate health service for those who most need it is a generally accepted priority. The evidence shows that individual characteristics, mainly health status, are the factors most closely related to primary care utilization. Other personal characteristics, such as gender and age, could act as modulators of health care need. Some family and/or cultural variables, as well as factors related to the health care professional and institutions, could explain some of the observed variability in primary care services utilization. Socioeconomic variables, such as income, reveal a paradox. From an aggregate perspective, income is the main determinant of utilization as well as of health care expenditure. When data are analyzed for individuals, however, income is not related to primary health utilization. The situation is controversial, with methodological implications and, above all, consequences for the assessment of the efficiency in primary care utilization. Review of the literature reveals certain methodological inconsistencies that could at least partly explain the disparity of the empirical results. Among others, the following flaws can be highlighted: design problems, measurement errors, misspecification, and misleading statistical methods.Some solutions, among others, are quasi-experiments, the use of large administrative databases and of primary data sources (design problems); differentiation between types of utilization and between units of analysis other than consultations, and correction of measurement errors in the explanatory variables (measurement errors); consideration of relevant explanatory variables (misspecification); and the use of multilevel models (statistical methods).

High intralocus variability and interlocus recombination promote immunological diversity in a minimal major histocompatibility system.

PubMed

Wilson, Anthony B; Whittington, Camilla M; Bahr, Angela

2014-12-20

The genes of the major histocompatibility complex (MHC/MH) have attracted considerable scientific interest due to their exceptional levels of variability and important function as part of the adaptive immune system. Despite a large number of studies on MH class II diversity of both model and non-model organisms, most research has focused on patterns of genetic variability at individual loci, failing to capture the functional diversity of the biologically active dimeric molecule. Here, we take a systematic approach to the study of MH variation, analyzing patterns of genetic variation at MH class IIα and IIβ loci of the seahorse, which together form the immunologically active peptide binding cleft of the MH class II molecule. The seahorse carries a minimal class II system, consisting of single copies of both MH class IIα and IIβ, which are physically linked and inherited in a Mendelian fashion. Both genes are ubiquitously expressed and detectible in the brood pouch of male seahorses throughout pregnancy. Genetic variability of the two genes is high, dominated by non-synonymous variation concentrated in their peptide-binding regions. Coding variation outside these regions is negligible, a pattern thought to be driven by intra- and interlocus recombination. Despite the tight physical linkage of MH IIα and IIβ loci, recombination has produced novel composite alleles, increasing functional diversity at sites responsible for antigen recognition. Antigen recognition by the adaptive immune system of the seahorse is enhanced by high variability at both MH class IIα and IIβ loci. Strong positive selection on sites involved in pathogen recognition, coupled with high levels of intra- and interlocus recombination, produce a patchwork pattern of genetic variation driven by genetic hitchhiking. Studies focusing on variation at individual MH loci may unintentionally overlook an important component of ecologically relevant variation.

Good genes, complementary genes and human mate preferences.

PubMed

Roberts, S Craig; Little, Anthony C

2008-03-01

The past decade has witnessed a rapidly growing interest in the biological basis of human mate choice. Here we review recent studies that demonstrate preferences for traits which might reveal genetic quality to prospective mates, with potential but still largely unknown influence on offspring fitness. These include studies assessing visual, olfactory and auditory preferences for potential good-gene indicator traits, such as dominance or bilateral symmetry. Individual differences in these robust preferences mainly arise through within and between individual variation in condition and reproductive status. Another set of studies have revealed preferences for traits indicating complementary genes, focussing on discrimination of dissimilarity at genes in the major histocompatibility complex (MHC). As in animal studies, we are only just beginning to understand how preferences for specific traits vary and inter-relate, how consideration of good and compatible genes can lead to substantial variability in individual mate choice decisions and how preferences expressed in one sensory modality may reflect those in another. Humans may be an ideal model species in which to explore these interesting complexities.

The role of non-need factors in individual GP utilisation analysis and their implications for the pursuance of equity: a cross-country comparison.

PubMed

McGregor, P; McKee, P; O'Neill, C

2008-05-01

A substantial amount of health care resources is allocated within the UK using formulae that relate funding to measures of population need. The aim of this paper is to demonstrate the importance of non-need factors in determining utilisation of services at an individual level and explore the implications inclusion of such factors has in the consideration of equity. In the paper we develop a utility model that accords a role to non-health factors in the determination of service use. A series of functions incorporating non-health factors as explanatory variables in GP utilisation functions are estimated using data from the British Household Panel Survey. The functions are decomposed to ascertain the role of service structure and examine the role of income across the four countries of the UK in explaining utilisation. The implications of our findings for the pursuance of equity in the NHS when individual choice has an explicit role are discussed.

Good genes, complementary genes and human mate preferences.

PubMed

Roberts, S Craig; Little, Anthony C

2008-09-01

The past decade has witnessed a rapidly growing interest in the biological basis of human mate choice. Here we review recent studies that demonstrate preferences for traits which might reveal genetic quality to prospective mates, with potential but still largely unknown influence on offspring fitness. These include studies assessing visual, olfactory and auditory preferences for potential good-gene indicator traits, such as dominance or bilateral symmetry. Individual differences in these robust preferences mainly arise through within and between individual variation in condition and reproductive status. Another set of studies have revealed preferences for traits indicating complementary genes, focussing on discrimination of dissimilarity at genes in the major histocompatibility complex (MHC). As in animal studies, we are only just beginning to understand how preferences for specific traits vary and inter-relate, how consideration of good and compatible genes can lead to substantial variability in individual mate choice decisions and how preferences expressed in one sensory modality may reflect those in another. Humans may be an ideal model species in which to explore these interesting complexities.

CHIT1 genetic defects in the Portuguese population.

PubMed

Duarte, Ana Joana; Ribeiro, Diogo; Amaral, Olga

2013-01-01

Chitotriosidase is an enzyme secreted by activated macrophages and a useful biomarker in several lysosomal and nonlysosomal diseases. However, chitotriosidase gene (CHIT1) mutations may lead to inaccuracy in the significance of this biomarker. Reports on the molecular spectrum of genetic variation in chitotriosidase are rare, and this is one of the few that focus on a specific population group. In this work we assessed the variation of CHIT1 mutations in ten normal controls and detected six missense alterations. G102S, a polymorphism with known altered catalytic properties, was the most frequent being detected in 4/10 individuals. Using allelic discrimination we tested 503 individuals, randomly sampled from the Portuguese population. Variant G102S was detected in 49.5% of the individuals and presented an allele frequency of 0.29. The results of this study showed that variability in CHIT1 gene is considerable and that G102S polymorphism presents a high frequency in the Portuguese. Copyright © 2012 Elsevier Inc. All rights reserved.

Evidence, Goals, and Outcomes in Stuttering Treatment: Applications With an Adolescent Who Stutters.

PubMed

Marcotte, Anne K

2018-01-09

The purpose of this clinical focus article is to summarize 1 possible process that a clinician might follow in designing and conducting a treatment program with John, a 14-year-old male individual who stutters. The available research evidence, practitioner experience, and consideration of individual preferences are combined to address goals, treatment procedures, and outcomes for John. The stuttering treatment research literature includes multiple well-designed reviews and individual studies that have shown the effectiveness of prolonged speech (and smooth speech and related variations) for improving stuttered speech and for improving social, emotional, cognitive, and related variables in adolescents who stutter. Based on that evidence, and incorporating the additional elements of practitioner experience and client preferences, this clinical focus article suggests that John would be likely to benefit from a treatment program based on prolonged speech. The basic structure of 1 possible such program is also described, with an emphasis on the goals and outcomes that John could be expected to achieve.

Vocal acoustic analysis as a biometric indicator of information processing: implications for neurological and psychiatric disorders.

PubMed

Cohen, Alex S; Dinzeo, Thomas J; Donovan, Neila J; Brown, Caitlin E; Morrison, Sean C

2015-03-30

Vocal expression reflects an integral component of communication that varies considerably within individuals across contexts and is disrupted in a range of neurological and psychiatric disorders. There is reason to suspect that variability in vocal expression reflects, in part, the availability of "on-line" resources (e.g., working memory, attention). Thus, understanding vocal expression is a potentially important biometric index of information processing, not only across but within individuals over time. A first step in this line of research involves establishing a link between vocal expression and information processing systems in healthy adults. The present study employed a dual attention experimental task where participants provided natural speech while simultaneously engaged in a baseline, medium or high nonverbal processing-load task. Objective, automated, and computerized analysis was employed to measure vocal expression in 226 adults. Increased processing load resulted in longer pauses, fewer utterances, greater silence overall and less variability in frequency and intensity levels. These results provide compelling evidence of a link between information processing resources and vocal expression, and provide important information for the development of an automated, inexpensive and uninvasive biometric measure of information processing. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sublethal effects of catch-and-release fishing: measuring capture stress, fish impairment, and predation risk using a condition index

USGS Publications Warehouse

Campbell, Matthew D.; Patino, Reynaldo; Tolan, J.M.; Strauss, R.E.; Diamond, S.

2009-01-01

The sublethal effects of simulated capture of red snapper (Lutjanus campechanus) were analysed using physiological responses, condition indexing, and performance variables. Simulated catch-and-release fishing included combinations of depth of capture and thermocline exposure reflective of environmental conditions experienced in the Gulf of Mexico. Frequency of occurrence of barotrauma and lack of reflex response exhibited considerable individual variation. When combined into a single condition or impairment index, individual variation was reduced, and impairment showed significant increases as depth increased and with the addition of thermocline exposure. Performance variables, such as burst swimming speed (BSS) and simulated predator approach distance (AD), were also significantly different by depth. BSSs and predator ADs decreased with increasing depth, were lowest immediately after release, and were affected for up to 15 min, with longer recovery times required as depth increased. The impairment score developed was positively correlated with cortisol concentration and negatively correlated with both BSS and simulated predator AD. The impairment index proved to be an efficient method to estimate the overall impairment of red snapper in the laboratory simulations of capture and shows promise for use in field conditions, to estimate release mortality and vulnerability to predation.

Neuroanatomical correlates of brain-computer interface performance.

PubMed

Kasahara, Kazumi; DaSalla, Charles Sayo; Honda, Manabu; Hanakawa, Takashi

2015-04-15

Brain-computer interfaces (BCIs) offer a potential means to replace or restore lost motor function. However, BCI performance varies considerably between users, the reasons for which are poorly understood. Here we investigated the relationship between sensorimotor rhythm (SMR)-based BCI performance and brain structure. Participants were instructed to control a computer cursor using right- and left-hand motor imagery, which primarily modulated their left- and right-hemispheric SMR powers, respectively. Although most participants were able to control the BCI with success rates significantly above chance level even at the first encounter, they also showed substantial inter-individual variability in BCI success rate. Participants also underwent T1-weighted three-dimensional structural magnetic resonance imaging (MRI). The MRI data were subjected to voxel-based morphometry using BCI success rate as an independent variable. We found that BCI performance correlated with gray matter volume of the supplementary motor area, supplementary somatosensory area, and dorsal premotor cortex. We suggest that SMR-based BCI performance is associated with development of non-primary somatosensory and motor areas. Advancing our understanding of BCI performance in relation to its neuroanatomical correlates may lead to better customization of BCIs based on individual brain structure. Copyright © 2015 Elsevier Inc. All rights reserved.

Pharmacokinetic and pharmacodynamic profile of supratherapeutic oral doses of Δ9-THC in cannabis users

PubMed Central

Lile, Joshua A.; Kelly, Thomas H.; Charnigo, Richard J.; Stinchcomb, Audra L.; Hays, Lon R.

2013-01-01

Oral Δ9-tetrahydrocannabinol (Δ9-THC) has been evaluated as a medication for cannabis dependence, but repeated administration of acute oral doses up to 40 mg has not been effective at reducing drug-taking behavior. Larger doses might be necessary to affect cannabis use. The purpose of the present study was therefore to determine the physiological and behavioral effects of oral Δ9-THC at acute doses higher than those tested previously. The pharmacokinetic and pharmacodynamic profile of oral Δ9-THC, administered in ascending order in 15 mg increments across separate sessions, up to a maximum of 90 mg, was determined in seven cannabis users. Five subjects received all doses and two experienced untoward side effects at lower doses. Δ9-THC produced a constellation of effects consistent with previous clinical studies. Low cannabinoid concentrations were associated with significant effects on drug- sensitive measures, although progressively greater levels did not lead to proportionately larger drug effects. Considerable variability in Cmax and tmax was observed. Doses of oral Δ9-THC larger than those tested previously can be administered to individuals with a history of cannabis use, although given the pharmacokinetic variability of oral Δ9-THC and individual differences in sensitivity, individualized dose adjustment is needed to avoid side effects and maximize therapeutic response. PMID:23754596

Climate change impacts on global food security.

PubMed

Wheeler, Tim; von Braun, Joachim

2013-08-02

Climate change could potentially interrupt progress toward a world without hunger. A robust and coherent global pattern is discernible of the impacts of climate change on crop productivity that could have consequences for food availability. The stability of whole food systems may be at risk under climate change because of short-term variability in supply. However, the potential impact is less clear at regional scales, but it is likely that climate variability and change will exacerbate food insecurity in areas currently vulnerable to hunger and undernutrition. Likewise, it can be anticipated that food access and utilization will be affected indirectly via collateral effects on household and individual incomes, and food utilization could be impaired by loss of access to drinking water and damage to health. The evidence supports the need for considerable investment in adaptation and mitigation actions toward a "climate-smart food system" that is more resilient to climate change influences on food security.

Fragile and Enduring Positive Affect: Implications for Adaptive Aging.

PubMed

Ong, Anthony D; Ram, Nilam

2017-01-01

There is robust evidence linking interindividual differences in positive affect (PA) with adaptive psychological and physical health outcomes. However, recent research has suggested that intraindividual variability or fluctuations in PA states over time may also be an important predictor of individual health outcomes. Here, we report on research that focuses on PA level and various forms of PA dynamics (variability, instability, inertia, and reactivity) in relation to health. PA level refers to the average level of positive feelings. In contrast, PA dynamics refer to short-term changes in PA that unfold over time. We discuss how consideration of both PA level and PA dynamics can provide a framework for reconciling when high PA is conducive or detrimental to health. We conclude that more work on PA dynamics is needed, especially in combination with PA level, and suggest productive questions for future inquiry in this area. © 2016 S. Karger AG, Basel.

Pediatric patients with common variable immunodeficiency: long-term follow-up.

PubMed

Mohammadinejad, P; Aghamohammadi, A; Abolhassani, H; Sadaghiani, M S; Abdollahzade, S; Sadeghi, B; Soheili, H; Tavassoli, M; Fathi, S M; Tavakol, M; Behniafard, N; Darabi, B; Pourhamdi, S; Rezaei, N

2012-01-01

Common variable immunodeficiency (CVID) is the most common form of symptomatic primary immunodeficiency disease. It is characterized by hypogammaglobulinemia, increased predisposition to infections, autoimmunity, and cancer. This study was performed to evaluate the clinical and immunological features of a group of pediatric patients with CVID. The study population comprised 69 individuals with CVID diagnosed during childhood. The patients were followed up for a mean (SD) period of 5.2 (4.3) years. The mean diagnostic delay was 4.4 (3.6) years, which was significantly lower in patients who were diagnosed recently. Children were classified according to 5 clinical phenotypes: infections only (n=39), polyclonal lymphocytic infiltration (n=17), autoimmunity (n=12), malignancy (n=7), and enteropathy (n=3). Postdiagnosis survival (10-year) was 71%. The high percentages of pediatric patients with CVID in Iran may be due to the considerable prevalence of parental consanguinity in the region and an underlying genetic background.

The origins of age of acquisition and typicality effects: Semantic processing in aphasia and the ageing brain.

PubMed

Räling, Romy; Schröder, Astrid; Wartenburger, Isabell

2016-06-01

Age of acquisition (AOA) has frequently been shown to influence response times and accuracy rates in word processing and constitutes a meaningful variable in aphasic language processing, while its origin in the language processing system is still under debate. To find out where AOA originates and whether and how it is related to another important psycholinguistic variable, namely semantic typicality (TYP), we studied healthy, elderly controls and semantically impaired individuals using semantic priming. For this purpose, we collected reaction times and accuracy rates as well as event-related potential data in an auditory category-member-verification task. The present results confirm a semantic origin of TYP, but question the same for AOA while favouring its origin at the phonology-semantics interface. The data are further interpreted in consideration of recent theories of ageing. Copyright © 2016 Elsevier Ltd. All rights reserved.

A cross-cultural comparison of the coexistence and domain superiority of individuating and relating autonomy.

PubMed

Yeh, Kuang-Hui; Bedford, Olwen; Yang, Yung-Jui

2009-06-01

The consensus definition of autonomy in the psychological literature emphasizes self-governance through free volition, not separation or independence from others. Since the concept of self may differ cross-culturally, several researchers have tried to incorporate types of self into the notion of autonomy; however, only the dual model of autonomy has been able to do this while retaining an emphasis on volition. The dual model describes two distinct forms of autonomy-individuating and relating-each with superior function in a specific domain of individual functioning. Individuating autonomy represents a volitional capacity to act against social constraints and offers a route to achieve an independent self-identity by expressing individualistic attributes and distinctions. Relating autonomy represents a volitional capacity to act by emphasizing the harmony of self-in-relation-to-others, the quality of interpersonal relationships, and self-transcendence. These two forms of autonomy have been shown to coexist at the individual level in a Taiwanese sample. This study takes the next step, with a cross-cultural test of the coexistence and domain superiority hypotheses of individuating and relating autonomy. Participants included 306 college students from Taiwan and 183 college students from the United States. Structural equation modelling by multigroup analyses confirmed the cross-cultural equivalence of the two-factor individuating autonomy and relating autonomy measurement model. Across both samples the two forms of autonomy were shown to be mutually inclusive and not exclusive or independent. The domain-superior function of each form of autonomy was also confirmed cross-culturally; each form of autonomy has a dominant, but not necessarily exclusive, domain of functioning. Specifically, individuating autonomy was more associated with intrapersonal than interpersonal domain dependent variables, while relating autonomy was more associated with interpersonal than intrapersonal domain dependent variables. Limitations of the study and considerations for future research are discussed.

Effective Assistive Technology Consideration and Implications for Diverse Students

ERIC Educational Resources Information Center

Jones, Vita L.; Hinesmon-Matthews, Lezlee J.

2014-01-01

Often the consideration of assistive technology devices and services during the individualized education program (IEP) process is overlooked. Because the Individuals with Disabilities Education Act (IDEA) authorized this consideration, IEP team members must be keenly aware of the importance they hold in providing this valuable input. Thus, IEP…

Von recklinghausens disease: a series of four cases with variable expression.

PubMed

Arun, K P; Thomas Joseph, P; Jaishankar, H P; Abhinethra, M S

2015-03-01

Though neurofibromatosis type I (NFI) is a fairly common condition, it has a variable expressivity and penetrance. Here we present a series of cases with striking differences in the presentation especially in the oral cavity. NFI, also known as von Recklinghausen's neurofibromatosis, is an autosomal dominantly inherited neurogenetic disorder affecting 1:3000 newborn (Bongiorno et al., Oral Dis 12:125-129, 2006). About 50 % of NFI patients have no family history of the disease. There is no prevalence for gender or race in NFI. Expressivity in NFI is tremendously variable, but subtle phenotypic patterns may exist within subgroups of affected patients. Furthermore, 50 % of cases are sporadic and arise from germ cell mutation (Bongiorno et al., Oral Dis 12:125-129, 2006). The precise constellation of findings in any one individual is extremely variable, both within a family and between different families (Batsakis, Tumors of the head and neck: clinical and pathological considerations, 2nd edn. Williams and Wilkins, Baltimore, pp 313-333, 1979). Only 4-7 % of patients affected by neurofibromatosis exhibit oral manifestations (Güneri et al., Turk J Pediatr 48(2):155-158, 2006).

Early Childhood Development Cultural Considerations--Commonalities, Variables, and Local Community Determinants for Program Modules.

ERIC Educational Resources Information Center

Taylor, Anne P.; Warren, Dave

The paper discusses cultural commonality and variability considerations of the Native American populations served by the Federation of Rocky Mountain States Educational Technical Development (ETD) Project. Section I explores important factors to consider when setting up an Early Childhood Development program module for Indian people, such as…

Intra-individual metameric variation expressed at the enamel-dentine junction of lower post-canine dentition of South African fossil hominins and modern humans.

PubMed

Pan, Lei; Thackeray, John Francis; Dumoncel, Jean; Zanolli, Clément; Oettlé, Anna; de Beer, Frikkie; Hoffman, Jakobus; Duployer, Benjamin; Tenailleau, Christophe; Braga, José

2017-08-01

The aim of this study is to compare the degree and patterning of inter- and intra-individual metameric variation in South African australopiths, early Homo and modern humans. Metameric variation likely reflects developmental and taxonomical issues, and could also be used to infer ecological and functional adaptations. However, its patterning along the early hominin postcanine dentition, particularly among South African fossil hominins, remains unexplored. Using microfocus X-ray computed tomography (µXCT) and geometric morphometric tools, we studied the enamel-dentine junction (EDJ) morphology and we investigated the intra- and inter-individual EDJ metameric variation among eight australopiths and two early Homo specimens from South Africa, as well as 32 modern humans. Along post-canine dentition, shape changes between metameres represented by relative positions and height of dentine horns, outlines of the EDJ occlusal table are reported in modern and fossil taxa. Comparisons of EDJ mean shapes and multivariate analyses reveal substantial variation in the direction and magnitude of metameric shape changes among taxa, but some common trends can be found. In modern humans, both the direction and magnitude of metameric shape change show increased variability in M 2 -M 3 compared to M 1 -M 2 . Fossil specimens are clustered together showing similar magnitudes of shape change. Along M 2 -M 3 , the lengths of their metameric vectors are not as variable as those of modern humans, but they display considerable variability in the direction of shape change. The distalward increase of metameric variation along the modern human molar row is consistent with the odontogenetic models of molar row structure (inhibitory cascade model). Though much remains to be tested, the variable trends and magnitudes in metamerism in fossil hominins reported here, together with differences in the scale of shape change between modern humans and fossil hominins may provide valuable information regarding functional morphology and developmental processes in fossil species. © 2017 Wiley Periodicals, Inc.

A method for determining haploid and triploid genotypes and their association with vascular phenotypes in Williams syndrome and 7q11.23 duplication syndrome.

PubMed

Gregory, Michael D; Kolachana, Bhaskar; Yao, Yin; Nash, Tiffany; Dickinson, Dwight; Eisenberg, Daniel P; Mervis, Carolyn B; Berman, Karen F

2018-04-04

Williams syndrome ([WS], 7q11.23 hemideletion) and 7q11.23 duplication syndrome (Dup7) show contrasting syndromic symptoms. However, within each group there is considerable interindividual variability in the degree to which these phenotypes are expressed. Though software exists to identify areas of copy number variation (CNV) from commonly-available SNP-chip data, this software does not provide non-diploid genotypes in CNV regions. Here, we describe a method for identifying haploid and triploid genotypes in CNV regions, and then, as a proof-of-concept for applying this information to explain clinical variability, we test for genotype-phenotype associations. Blood samples for 25 individuals with WS and 13 individuals with Dup7 were genotyped with Illumina-HumanOmni5M SNP-chips. PennCNV and in-house code were used to make genotype calls for each SNP in the 7q11.23 locus. We tested for association between the presence of aortic arteriopathy and genotypes of the remaining (haploid in WS) or duplicated (triploid in Dup7) alleles. Haploid calls in the 7q11.23 region were made for 99.0% of SNPs in the WS group, and triploid calls for 98.8% of SNPs in those with Dup7. The G allele of SNP rs2528795 in the ELN gene was associated with aortic stenosis in WS participants (p < 0.0049) while the A allele of the same SNP was associated with aortic dilation in Dup7. Commonly available SNP-chip information can be used to make haploid and triploid calls in individuals with CNVs and then to relate variability in specific genes to variability in syndromic phenotypes, as demonstrated here using aortic arteriopathy. This work sets the stage for similar genotype-phenotype analyses in CNVs where phenotypes may be more complex and/or where there is less information about genetic mechanisms.

Developmental Differences in Intra-Individual Variability in Children with ADHD and ASD

ERIC Educational Resources Information Center

Belle, Janna; van Hulst, Branko M.; Durston, Sarah

2015-01-01

Background: Intra-individual variability reflects temporal variation within an individual's performance on a cognitive task. Children with developmental disorders, such as ADHD and ASD show increased levels of intra-individual variability. In typical development, intra-individual variability decreases sharply between the ages 6 and 20. The tight…

Short-term quality of life after subthalamic stimulation depends on non-motor symptoms in Parkinson's disease.

PubMed

Dafsari, Haidar Salimi; Weiß, Luisa; Silverdale, Monty; Rizos, Alexandra; Reddy, Prashanth; Ashkan, Keyoumars; Evans, Julian; Reker, Paul; Petry-Schmelzer, Jan Niklas; Samuel, Michael; Visser-Vandewalle, Veerle; Antonini, Angelo; Martinez-Martin, Pablo; Ray-Chaudhuri, K; Timmermann, Lars

2018-02-24

Subthalamic nucleus (STN) deep brain stimulation (DBS) improves quality of life (QoL), motor, and non-motor symptoms (NMS) in advanced Parkinson's disease (PD). However, considerable inter-individual variability has been observed for QoL outcome. We hypothesized that demographic and preoperative NMS characteristics can predict postoperative QoL outcome. In this ongoing, prospective, multicenter study (Cologne, Manchester, London) including 88 patients, we collected the following scales preoperatively and on follow-up 6 months postoperatively: PDQuestionnaire-8 (PDQ-8), NMSScale (NMSS), NMSQuestionnaire (NMSQ), Scales for Outcomes in PD (SCOPA)-motor examination, -complications, and -activities of daily living, levodopa equivalent daily dose. We dichotomized patients into "QoL responders"/"non-responders" and screened for factors associated with QoL improvement with (1) Spearman-correlations between baseline test scores and QoL improvement, (2) step-wise linear regressions with baseline test scores as independent and QoL improvement as dependent variables, (3) logistic regressions using aforementioned "responders/non-responders" as dependent variable. All outcomes improved significantly on follow-up. However, approximately 44% of patients were categorized as "QoL non-responders". Spearman-correlations, linear and logistic regression analyses were significant for NMSS and NMSQ but not for SCOPA-motor examination. Post-hoc, we identified specific NMS (flat moods, difficulties experiencing pleasure, pain, bladder voiding) as significant contributors to QoL outcome. Our results provide evidence that QoL improvement after STN-DBS depends on preoperative NMS characteristics. These findings are important in the advising and selection of individuals for DBS therapy. Future studies investigating motor and non-motor PD clusters may enable stratifying QoL outcomes and help predict patients' individual prospects of benefiting from DBS. Copyright © 2018. Published by Elsevier Inc.

Use of Magnetic Resonance Imaging to Monitor Iron Overload

PubMed Central

Wood, John C.

2014-01-01

SYNOPSIS Treatment of iron overload requires robust estimates of total body iron burden and its response to iron chelation therapy. Compliance with chelation therapy varies considerably among patients and individual reporting is notoriously unreliable. Even with perfect compliance, intersubject variability in chelator effectiveness is extremely high, necessitating reliable iron estimates to guide dose titration. In addition, each chelator has a unique profile with respect to clearing iron stores from different organs. This chapter will present the tools available to clinicians monitoring their patients, focusing on non-invasive magnetic resonance imaging methods because they have become the de-facto standard of care. PMID:25064711

Human Milk and Allergic Diseases: An Unsolved Puzzle

PubMed Central

Peroni, Diego G.; Boix-Amorós, Alba; Hsu, Peter S.; Van’t Land, Belinda; Skevaki, Chrysanthi; Collado, Maria Carmen; Garssen, Johan; Geddes, Donna T.; Nanan, Ralph; Slupsky, Carolyn; Wegienka, Ganesa; Kozyrskyj, Anita L.; Warner, John O.

2017-01-01

There is conflicting evidence on the protective role of breastfeeding in relation to the development of allergic sensitisation and allergic disease. Studies vary in methodology and definition of outcomes, which lead to considerable heterogeneity. Human milk composition varies both within and between individuals, which may partially explain conflicting data. It is known that human milk composition is very complex and contains variable levels of immune active molecules, oligosaccharides, metabolites, vitamins and other nutrients and microbial content. Existing evidence suggests that modulation of human breast milk composition has potential for preventing allergic diseases in early life. In this review, we discuss associations between breastfeeding/human milk composition and allergy development. PMID:28817095

Human Milk and Allergic Diseases: An Unsolved Puzzle.

PubMed

Munblit, Daniel; Peroni, Diego G; Boix-Amorós, Alba; Hsu, Peter S; Van't Land, Belinda; Gay, Melvin C L; Kolotilina, Anastasia; Skevaki, Chrysanthi; Boyle, Robert J; Collado, Maria Carmen; Garssen, Johan; Geddes, Donna T; Nanan, Ralph; Slupsky, Carolyn; Wegienka, Ganesa; Kozyrskyj, Anita L; Warner, John O

2017-08-17

There is conflicting evidence on the protective role of breastfeeding in relation to the development of allergic sensitisation and allergic disease. Studies vary in methodology and definition of outcomes, which lead to considerable heterogeneity. Human milk composition varies both within and between individuals, which may partially explain conflicting data. It is known that human milk composition is very complex and contains variable levels of immune active molecules, oligosaccharides, metabolites, vitamins and other nutrients and microbial content. Existing evidence suggests that modulation of human breast milk composition has potential for preventing allergic diseases in early life. In this review, we discuss associations between breastfeeding/human milk composition and allergy development.

Factors governing the total rainfall yield from continental convective clouds

NASA Technical Reports Server (NTRS)

Rosenfeld, Daniel; Gagin, Abraham

1989-01-01

Several important factors that govern the total rainfall from continental convective clouds were investigated by tracking thousands of convective cells in Israel and South Africa. The rainfall volume yield (Rvol) of the individual cells that build convective rain systems has been shown to depend mainly on the cloud-top height. There is, however, considerable variability in this relationship. The following factors that influence the Rvol were parameterized and quantitatively analyzed: (1) cloud base temperature, (2)atmospheric instability, and (3) the extent of isolation of the cell. It is also shown that a strong low level forcing increases the duration of Rvol of clouds reaching the same vertical extent.

Facilitatory non-invasive brain stimulation in older adults: the effect of stimulation type and duration on the induction of motor cortex plasticity.

PubMed

Puri, Rohan; Hinder, Mark R; Canty, Alison J; Summers, Jeffery J

2016-12-01

Despite holding significant promise for counteracting the deleterious effects of ageing on cognitive and motor function, little is known of the effects of facilitatory non-invasive brain stimulation (NBS) techniques on corticospinal excitability (CSE) in older adults. Thirty-three older adults (≥60 years) participated in four NBS sessions on separate days, receiving 10- and 20-min anodal transcranial direct current stimulation (atDCS), and 300 and 600 pulses of intermittent theta burst stimulation (iTBS) over the left M1. Motor-evoked potentials measured in the contralateral hand served as a measure of CSE before and for 30 min following each NBS intervention. At the group level, generalized post-stimulation CSE increases were observed (p < 0.001) with no significant differences between the two durations of each stimulation type (atDCS: p = 0.5; iTBS: p = 0.9). For individuals exhibiting overall facilitatory change to atDCS ('responders', n = 10), 20-min atDCS resulted in longer lasting CSE facilitation than 10 min. No such difference was observed between the two iTBS protocols. Considerable variability was observed inter-individually, where 52-58 % of the cohort exhibited the expected facilitation after each of the NBS protocols-as well as intra-individually, where 45-48 % of the cohort maintained consistent post-stimulation responses across the varying durations and types of stimulation. In conclusion, as shown previously in young adults, older adults demonstrate substantial variability in response to different facilitatory NBS protocols. Studies to assess the intra-individual reliability of these protocols are critical to progress towards translation of appropriate protocols (i.e. those that elicit the greatest response for each individual) into clinical practice.

The association between patient attitudes and values and the strength of consideration for contralateral prophylactic mastectomy in a population-based sample of breast cancer patients.

PubMed

Hawley, Sarah T; Griffith, Kent A; Hamilton, Ann S; Ward, Kevin C; Morrow, Monica; Janz, Nancy K; Katz, Steven J; Jagsi, Reshma

2017-12-01

Little is known about how the individual decision styles and values of breast cancer patients at the time of treatment decision making are associated with the consideration of different treatment options and specifically with the consideration of contralateral prophylactic mastectomy (CPM). Newly diagnosed patients with early-stage breast cancer who were treated in 2013-2014 were identified through the Surveillance, Epidemiology, and End Results registries of Los Angeles and Georgia and were surveyed approximately 7 months after surgery (n = 2578; response rate, 71%). The primary outcome was the consideration of CPM (strong vs less strong). The association between patients' values and decision styles and strong consideration was assessed with multivariate logistic regression. Approximately one-quarter of women (25%) reported strong/very strong consideration of CPM, and another 29% considered it moderately/weakly. Decision styles, including a rational-intuitive approach to decision making, varied. The factors most valued by women at the time of treatment decision making were as follows: avoiding worry about recurrence (82%) and reducing the need for more surgery (73%). In a multivariate analysis, patients who preferred to make their own decisions, those who valued avoiding worry about recurrence, and those who valued avoiding radiation significantly more often strongly considered CPM (P < .05), whereas those who reported being more logical and those who valued keeping their breast did so less often. Many patients considered CPM, and the consideration was associated with both decision styles and values. The variability in decision styles and values observed in this study suggests that formally evaluating these characteristics at or before the initial treatment encounter could provide an opportunity for improving patient clinician discussions. Cancer 2017;123:4547-4555. © 2017 American Cancer Society. © 2017 American Cancer Society.

Nonsuicidal self-injury in community adolescents: A systematic review of prospective predictors, mediators and moderators.

PubMed

Valencia-Agudo, Fatima; Burcher, Georgina Corbet; Ezpeleta, Lourdes; Kramer, Tami

2018-06-01

Nonsuicidal self-injury (NSSI) usually starts during adolescence and is associated with an array of psychological and psychiatric symptoms and future suicide attempts. The aim of this study is to determine prospective predictors, mediators and moderators of NSSI in adolescent community samples in order to target prevention and treatment strategies. Two team members searched online databases independently. Thirty-nine studies were included in the review. Several variables were seen to prospectively predict NSSI: female gender, family-related variables, peer victimisation, depression, previous NSSI and self-concept. Few studies analysed mediators and moderators. Low self-concept was highlighted as a relevant moderator in the relationship between intra/interpersonal variables and NSSI. Implications of these findings are discussed. The considerable heterogeneity between studies posed a limitation to determine robust predictors of NSSI. Further prospective studies using standardised measures of predictors and outcomes are needed to ascertain the most at risk individuals and develop prevention strategies. Copyright © 2018 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Effects of constant and cyclical thermal regimes on growth and feeding of juvenile cutthroat trout of variable sizes

USGS Publications Warehouse

Meeuwig, M.H.; Dunham, J.B.; Hayes, J.P.; Vinyard, G.L.

2004-01-01

The effects of constant (12, 18, and 24 A?C) and cyclical (daily variation of 15a??21 and 12a??24 A?C) thermal regimes on the growth and feeding of Lahontan cutthroat trout (Oncorhynchus clarki henshawi) of variable sizes were examined. Higher constant temperatures (i.e., 24 A?C) and more variable daily temperatures (i.e., 12a??24 A?C daily cycle) negatively affected growth rates. As fish mass increased (from 0.24 to 15.52 g) the effects of different thermal regimes on mass growth became more pronounced. Following 14 days exposure to the thermal regimes, feeding rates of individual fish were assessed during acute exposure (40 min) to test temperatures of 12, 18, and 24 A?C. Feeding rate was depressed during acute exposure to 24 A?C, but was not significantly affected by the preceding thermal regime. Our results indicate that even brief daily exposure to higher temperatures (e.g., 24 A?C) can have considerable sublethal effects on cutthroat trout, and that fish size should be considered when examining the effects of temperature.

Risk and protective factors for structural brain ageing in the eighth decade of life.

PubMed

Ritchie, Stuart J; Tucker-Drob, Elliot M; Cox, Simon R; Dickie, David Alexander; Del C Valdés Hernández, Maria; Corley, Janie; Royle, Natalie A; Redmond, Paul; Muñoz Maniega, Susana; Pattie, Alison; Aribisala, Benjamin S; Taylor, Adele M; Clarke, Toni-Kim; Gow, Alan J; Starr, John M; Bastin, Mark E; Wardlaw, Joanna M; Deary, Ian J

2017-11-01

Individuals differ markedly in brain structure, and in how this structure degenerates during ageing. In a large sample of human participants (baseline n = 731 at age 73 years; follow-up n = 488 at age 76 years), we estimated the magnitude of mean change and variability in changes in MRI measures of brain macrostructure (grey matter, white matter, and white matter hyperintensity volumes) and microstructure (fractional anisotropy and mean diffusivity from diffusion tensor MRI). All indices showed significant average change with age, with considerable heterogeneity in those changes. We then tested eleven socioeconomic, physical, health, cognitive, allostatic (inflammatory and metabolic), and genetic variables for their value in predicting these differences in changes. Many of these variables were significantly correlated with baseline brain structure, but few could account for significant portions of the heterogeneity in subsequent brain change. Physical fitness was an exception, being correlated both with brain level and changes. The results suggest that only a subset of correlates of brain structure are also predictive of differences in brain ageing.

Cortisol and salivary alpha-amylase trajectories following a group social-evaluative stressor with adolescents.

PubMed

Katz, Deirdre A; Peckins, Melissa K

2017-12-01

Intraindividual variability in stress responsivity and the interrelationship of multiple neuroendocrine systems make a multisystem analytic approach to examining the human stress response challenging. The present study makes use of an efficient social-evaluative stress paradigm - the Group Public Speaking Task for Adolescents (GPST-A) - to examine the hypothalamic-pituitary-adrenocortical (HPA)-axis and Autonomic Nervous System (ANS) reactivity profiles of 54 adolescents with salivary cortisol and salivary alpha-amylase (sAA). First, we account for individuals' time latency of hormone concentrations between individuals. Second, we use a two-piece multilevel growth curve model with landmark registration to examine the reactivity and recovery periods of the stress response separately. This analytic approach increases the models' sensitivity to detecting trajectory differences in the reactivity and recovery phases of the stress response and allows for interindividual variation in the timing of participants' peak response following a social-evaluative stressor. The GPST-A evoked typical cortisol and sAA responses in both males and females. Males' cortisol concentrations were significantly higher than females' during each phase of the response. We found no gender difference in the sAA response. However, the rate of increase in sAA as well as overall sAA secretion across the study were associated with steeper rates of cortisol reactivity and recovery. This study demonstrates a way to model the response trajectories of salivary biomarkers of the HPA-axis and ANS when taking a multisystem approach to neuroendocrine research that enables researchers to make conclusions about the reactivity and recovery phases of the HPA-axis and ANS responses. As the study of the human stress response progresses toward a multisystem analytic approach, it is critical that individual variability in peak latency be taken into consideration and that accurate modeling techniques capture individual variability in the stress response so that accurate conclusions can be made about separate phases of the response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Specific-age group sex estimation of infants through geometric morphometrics analysis of pubis and ischium.

PubMed

Estévez Campo, Enrique José; López-Lázaro, Sandra; López-Morago Rodríguez, Claudia; Alemán Aguilera, Inmaculada; Botella López, Miguel Cecilio

2018-05-01

Sex determination of unknown individuals is one of the primary goals of Physical and Forensic Anthropology. The adult skeleton can be sexed using both morphological and metric traits on a large number of bones. The human pelvis is often used as an important element of adult sex determination. However, studies carried out about the pelvic bone in subadult individuals present several limitations due the absence of sexually dimorphic characteristics. In this study, we analyse the sexual dimorphism of the immature pubis and ischium bones, attending to their shape (Procrustes residuals) and size (centroid size), using an identified sample of subadult individuals composed of 58 individuals for the pubis and 83 for the ischium, aged between birth and 1year of life, from the Granada osteological collection of identified infants (Granada, Spain). Geometric morphometric methods and discriminant analysis were applied to this study. The results of intra- and inter-observer error showed good and excellent agreement in the location of coordinates of landmarks and semilandmarks, respectively. Principal component analysis performed on shape and size variables showed superposition of the two sexes, suggesting a low degree of sexual dimorphism. Canonical variable analysis did not show significant changes between the male and female shapes. As a consequence, discriminant analysis with leave-one-out cross validation provided low classification accuracy. The results suggested a low degree of sexual dimorphism supported by significant sexual dimorphism in the subadult sample and poor cross-validated classification accuracy. The inclusion of centroid size as a discriminant variable does not imply a significant improvement in the results of the analysis. The similarities found between the sexes prevent consideration of pubic and ischial morphology as a sex estimator in early stages of development. The authors suggest extending this study by analysing the different trajectories of shape and size in later ontogeny between males and females. Copyright © 2018 Elsevier B.V. All rights reserved.

Novel Biomarkers for Predicting Cardiovascular Disease in Patients With Diabetes.

PubMed

Retnakaran, Ravi

2018-05-01

It is generally acknowledged that patients with diabetes comprise a high-risk population for the development of cardiovascular disease. However, it is perhaps less well recognized that there actually exists considerable heterogeneity in vascular risk within this patient population, with a sizable subset of individuals seemingly at low risk for major cardiovascular events despite the presence of diabetes. Because traditional clinical risk calculators have shown wide variability in their performance in the setting of diabetes, there exists a need for additional risk predictors in this patient population. In this context, there has been considerable interest in the potential utility of circulating biomarkers as clinical tools that might facilitate risk stratification and thereby guide therapeutic and preventative decision-making. Coupled with the current era of dedicated cardiovascular outcome trials in type 2 diabetes, this interest has spawned a growing literature of recent studies that evaluated potential biomarkers. To date, these studies have identified N-terminal pro-B-type natriuretic peptide, high-sensitivity cardiac troponins, and growth differentiation factor-15 as cardiovascular biomarkers of particular potential in patients with diabetes. Furthermore, recognizing the potential benefit of collective consideration of different biomarkers reflecting distinct pathophysiologic processes that might contribute to the development of cardiovascular disease, there is emerging emphasis on the evaluation of combinations of biomarkers for optimal risk prediction. Although not currently ready for clinical practice, this rapidly-growing topic of biomarker research might ultimately facilitate the goal of individualized risk stratification and thereby enable truly personalized management of diabetes. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Integrating Behavioral Economics and Behavioral Genetics: Delayed Reward Discounting as an Endophenotype for Addictive Disorders

PubMed Central

MacKillop, James

2013-01-01

Delayed reward discounting is a behavioral economic index of impulsivity, referring to how much an individual devalues a reward based on its delay in time. As a behavioral process that varies considerably across individuals, delay discounting has been studied extensively as a model for self-control, both in the general population and in clinical samples. There is growing interest in genetic influences on discounting and, in particular, the prospect of discounting as an endophenotype for addictive disorders (i.e., a heritable mechanism partially responsible for conferring genetic risk). This review assembles and critiques the evidence supporting this hypothesis. Via numerous cross-sectional studies and a small number of longitudinal studies, there is considerable evidence that impulsive discounting is associated with addictive behavior and appears to play an etiological role. Moreover, there is increasing evidence from diverse methodologies that impulsive delay discounting is temporally stable, heritable, and that elevated levels are present in nonaffected family members. These findings suggest that impulsive discounting meets the criteria for being considered an endophenotype. In addition, recent findings suggest that genetic variation related to dopamine neurotransmission is significantly associated with variability in discounting preferences. A significant caveat, however, is that the literature is modest in some domains and, in others, not all the findings have been supportive or consistent. In addition, important methodological considerations are necessary in future studies. Taken together, although not definitive, there is accumulating support for the hypothesis of impulsive discounting as an endophenotype for addictive behavior and a need for further systematic investigation. PMID:23344986

Tailoring treatment of haemophilia B: accounting for the distribution and clearance of standard and extended half-life FIX concentrates.

PubMed

Iorio, Alfonso; Fischer, Kathelijn; Blanchette, Victor; Rangarajan, Savita; Young, Guy; Morfini, Massimo

2017-06-02

The prophylactic administration of factor IX (FIX) is considered the most effective treatment for haemophilia B. The inter-individual variability and complexity of the pharmacokinetics (PK) of FIX, and the rarity of the disease have hampered identification of an optimal treatment regimens. The recent introduction of extended half-life recombinant FIX molecules (EHL-rFIX), has prompted a thorough reassessment of the clinical efficacy, PK and pharmacodynamics of plasma-derived and recombinant FIX. First, using longer sampling times and multi-compartmental PK models has led to more precise (and favourable) PK for FIX than was appreciated in the past. Second, investigating the distribution of FIX in the body beyond the vascular space (which is implied by its complex kinetics) has opened a new research field on the role for extravascular FIX. Third, measuring plasma levels of EHL-rFIX has shown that different aPTT reagents have different accuracy in measuring different FIX molecules. How will this new knowledge reflect on clinical practice? Clinical decision making in haemophilia B requires some caution and expertise. First, comparisons between different FIX molecules must be assessed taking into consideration the comparability of the populations studied and the PK models used. Second, individual PK estimates must rely on multi-compartmental models, and would benefit from adopting a population PK approach. Optimal sampling times need to be adapted to the prolonged half-life of the new EHL FIX products. Finally, costs considerations may apply, which is beyond the scope of this manuscript but might be deeply connected with the PK considerations discussed in this communication.

Parent insights into atypicalities of social approach behaviour in Williams syndrome.

PubMed

Lough, E; Rodgers, J; Janes, E; Little, K; Riby, D M

2016-11-01

Individuals with Williams syndrome have been reported to show high levels of social interest and a desire to interact with others irrespective of their familiarity. This high social motivation, when combined with reduced intellectual capacity and a profile of atypical social behaviour, is important in terms of social vulnerability of individuals with the disorder. Therefore, social approach to unfamiliar people and the role of this behaviour within the Williams syndrome (WS) social phenotype warrant further research to inform social skills' intervention design. The current study used parent interviews (n = 21) to probe aspects of social behaviour and interactions with strangers, as well as the impact of such behaviour on the family. Using thematic analysis, it was possible to explore themes that emerged from the interviews, offering qualitatively rich insight into the variability of social approach behaviour in WS. Thematic analysis confirmed a significant desire to interact with strangers as well as a lack of awareness of appropriate social boundaries. However, parental reports about their child's social approach behaviour varied considerably. The within-syndrome variability of the sample was emphasised in parental reports of their child's personality characteristics (e.g. levels of impulsiveness), as well as the level of parental supervision employed. These in-depth parent insights can help target the needs of individuals with WS and emphasise that an individual approach to intervention will be essential because of the heterogeneity of the WS social profile. © 2016 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Ultrastructural diversity between centrioles of eukaryotes.

PubMed

Gupta, Akshari; Kitagawa, Daiju

2018-02-16

Several decades of centriole research have revealed the beautiful symmetry present in these microtubule-based organelles, which are required to form centrosomes, cilia, and flagella in many eukaryotes. Centriole architecture is largely conserved across most organisms, however, individual centriolar features such as the central cartwheel or microtubule walls exhibit considerable variability when examined with finer resolution. Here, we review the ultrastructural characteristics of centrioles in commonly studied organisms, highlighting the subtle and not-so-subtle differences between specific structural components of these centrioles. Additionally, we survey some non-canonical centriole structures that have been discovered in various species, from the coaxial bicentrioles of protists and lower land plants to the giant irregular centrioles of the fungus gnat Sciara. Finally, we speculate on the functional significance of these differences between centrioles, and the contribution of individual structural elements such as the cartwheel or microtubules towards the stability of centrioles.Centriole structure, cartwheel, triplet microtubules, SAS-6, centrosome.

Midsole material-related force control during heel-toe running.

PubMed

Kersting, Uwe G; Brüggemann, Gert-Peter

2006-01-01

The impact maximum and rearfoot eversion have been used as indicators of load on internal structures in running. The midsole hardness of a typical running shoe was varied systematically to determine the relationship between external ground reaction force (GRF), in-shoe force, and kinematic variables. Eight subjects were tested during overground running at 4 m/s. Rearfoot movement as well as in-shoe forces and external GRF varied nonsystematically with midsole hardness. Kinematic parameters such as knee flexion and foot velocity at touchdown (TD), also varied nonsystematically with altered midsole hardness. Results demonstrate that considerable variations of in-shoe loading occur that were not depicted by external GRF measurements alone. Individuals apparently use different strategies of mechanical and neuromuscular adaptation in response to footwear modifications. In conclusion, shoe design effects on impact forces or other factors relating to injuries depend on the individual and therefore cannot be generalized.

Creep-fatigue interaction at high temperature; Proceedings of the Symposium, 112th ASME Winter Annual Meeting, Atlanta, GA, Dec. 1-6, 1991

NASA Astrophysics Data System (ADS)

Haritos, George K.; Ochoa, O. O.

Various papers on creep-fatigue interaction at high temperature are presented. Individual topics addressed include: analysis of elevated temperature fatigue crack growth mechanisms in Alloy 718, physically based microcrack propagation laws for creep-fatigue-environment interaction, in situ SEM observation of short fatigue crack growth in Waspaloy at 700 C under cyclic and dwell conditions, evolution of creep-fatigue life prediction models, TMF design considerations in turbine airfoils of advanced turbine engines. Also discussed are: high temperature fatigue life prediction computer code based on the total strain version of strainrange partitioning, atomic theory of thermodynamics of internal variables, geometrically nonlinear analysis of interlaminar stresses in unsymmetrically laminated plates subjected to uniform thermal loading, experimental investigation of creep crack tip deformation using moire interferometry. (For individual items see A93-31336 to A93-31344)

Fine scale relationships between sex, life history, and dispersal of masu salmon

USGS Publications Warehouse

Kitanishi, Shigeru; Yamamoto, Toshiaki; Koizumi, Itsuro; Dunham, Jason B.; Higashi, Seigo

2012-01-01

Identifying the patterns and processes driving dispersal is critical for understanding population structure and dynamics. In many organisms, sex-biased dispersal is related to the type of mating system. Considerably less is known about the influence of life history variability on dispersal. Here we investigated patterns of dispersal in masu salmon (Oncorhynchus masou) to evaluate influences of sex and life history on dispersal. As expected, assignment tests and isolation by distance analysis revealed that dispersal of marine-migratory masu salmon was male-biased. However, dispersal of resident and migratory males did not follow our expectation and marine-migratory individuals dispersed more than residents. This may be because direct competition between marine-migratory and resident males is weak or that the cost of dispersal is smaller for marine-migratory individuals. This study revealed that both sex and migratory life history influence patterns of dispersal at a local scale in masu salmon.

Genome typing of nonhuman primate models: implications for biomedical research.

PubMed

Haus, Tanja; Ferguson, Betsy; Rogers, Jeffrey; Doxiadis, Gaby; Certa, Ulrich; Rose, Nicola J; Teepe, Robert; Weinbauer, Gerhard F; Roos, Christian

2014-11-01

The success of personalized medicine rests on understanding the genetic variation between individuals. Thus, as medical practice evolves and variation among individuals becomes a fundamental aspect of clinical medicine, a thorough consideration of the genetic and genomic information concerning the animals used as models in biomedical research also becomes critical. In particular, nonhuman primates (NHPs) offer great promise as models for many aspects of human health and disease. These are outbred species exhibiting substantial levels of genetic variation; however, understanding of the contribution of this variation to phenotypes is lagging behind in NHP species. Thus, there is a pivotal need to address this gap and define strategies for characterizing both genomic content and variability within primate models of human disease. Here, we discuss the current state of genomics of NHP models and offer guidelines for future work to ensure continued improvement and utility of this line of biomedical research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of clinical input variable uncertainties on ten-year atherosclerotic cardiovascular disease risk using new pooled cohort equations.

PubMed

Gupta, Himanshu; Schiros, Chun G; Sharifov, Oleg F; Jain, Apurva; Denney, Thomas S

2016-08-31

Recently released American College of Cardiology/American Heart Association (ACC/AHA) guideline recommends the Pooled Cohort equations for evaluating atherosclerotic cardiovascular risk of individuals. The impact of the clinical input variable uncertainties on the estimates of ten-year cardiovascular risk based on ACC/AHA guidelines is not known. Using a publicly available the National Health and Nutrition Examination Survey dataset (2005-2010), we computed maximum and minimum ten-year cardiovascular risks by assuming clinically relevant variations/uncertainties in input of age (0-1 year) and ±10 % variation in total-cholesterol, high density lipoprotein- cholesterol, and systolic blood pressure and by assuming uniform distribution of the variance of each variable. We analyzed the changes in risk category compared to the actual inputs at 5 % and 7.5 % risk limits as these limits define the thresholds for consideration of drug therapy in the new guidelines. The new-pooled cohort equations for risk estimation were implemented in a custom software package. Based on our input variances, changes in risk category were possible in up to 24 % of the population cohort at both 5 % and 7.5 % risk boundary limits. This trend was consistently noted across all subgroups except in African American males where most of the cohort had ≥7.5 % baseline risk regardless of the variation in the variables. The uncertainties in the input variables can alter the risk categorization. The impact of these variances on the ten-year risk needs to be incorporated into the patient/clinician discussion and clinical decision making. Incorporating good clinical practices for the measurement of critical clinical variables and robust standardization of laboratory parameters to more stringent reference standards is extremely important for successful implementation of the new guidelines. Furthermore, ability to customize the risk calculator inputs to better represent unique clinical circumstances specific to individual needs would be highly desirable in the future versions of the risk calculator.

Is rigorous retrospective harmonization possible? Application of the DataSHaPER approach across 53 large studies

PubMed Central

Fortier, Isabel; Doiron, Dany; Little, Julian; Ferretti, Vincent; L’Heureux, François; Stolk, Ronald P; Knoppers, Bartha M; Hudson, Thomas J; Burton, Paul R

2011-01-01

Background Proper understanding of the roles of, and interactions between genetic, lifestyle, environmental and psycho-social factors in determining the risk of development and/or progression of chronic diseases requires access to very large high-quality databases. Because of the financial, technical and time burdens related to developing and maintaining very large studies, the scientific community is increasingly synthesizing data from multiple studies to construct large databases. However, the data items collected by individual studies must be inferentially equivalent to be meaningfully synthesized. The DataSchema and Harmonization Platform for Epidemiological Research (DataSHaPER; http://www.datashaper.org) was developed to enable the rigorous assessment of the inferential equivalence, i.e. the potential for harmonization, of selected information from individual studies. Methods This article examines the value of using the DataSHaPER for retrospective harmonization of established studies. Using the DataSHaPER approach, the potential to generate 148 harmonized variables from the questionnaires and physical measures collected in 53 large population-based studies (6.9 million participants) was assessed. Variable and study characteristics that might influence the potential for data synthesis were also explored. Results Out of all assessment items evaluated (148 variables for each of the 53 studies), 38% could be harmonized. Certain characteristics of variables (i.e. relative importance, individual targeted, reference period) and of studies (i.e. observational units, data collection start date and mode of questionnaire administration) were associated with the potential for harmonization. For example, for variables deemed to be essential, 62% of assessment items paired could be harmonized. Conclusion The current article shows that the DataSHaPER provides an effective and flexible approach for the retrospective harmonization of information across studies. To implement data synthesis, some additional scientific, ethico-legal and technical considerations must be addressed. The success of the DataSHaPER as a harmonization approach will depend on its continuing development and on the rigour and extent of its use. The DataSHaPER has the potential to take us closer to a truly collaborative epidemiology and offers the promise of enhanced research potential generated through synthesized databases. PMID:21804097

Unilateral Hearing Loss: Understanding Speech Recognition and Localization Variability-Implications for Cochlear Implant Candidacy.

PubMed

Firszt, Jill B; Reeder, Ruth M; Holden, Laura K

At a minimum, unilateral hearing loss (UHL) impairs sound localization ability and understanding speech in noisy environments, particularly if the loss is severe to profound. Accompanying the numerous negative consequences of UHL is considerable unexplained individual variability in the magnitude of its effects. Identification of covariables that affect outcome and contribute to variability in UHLs could augment counseling, treatment options, and rehabilitation. Cochlear implantation as a treatment for UHL is on the rise yet little is known about factors that could impact performance or whether there is a group at risk for poor cochlear implant outcomes when hearing is near-normal in one ear. The overall goal of our research is to investigate the range and source of variability in speech recognition in noise and localization among individuals with severe to profound UHL and thereby help determine factors relevant to decisions regarding cochlear implantation in this population. The present study evaluated adults with severe to profound UHL and adults with bilateral normal hearing. Measures included adaptive sentence understanding in diffuse restaurant noise, localization, roving-source speech recognition (words from 1 of 15 speakers in a 140° arc), and an adaptive speech-reception threshold psychoacoustic task with varied noise types and noise-source locations. There were three age-sex-matched groups: UHL (severe to profound hearing loss in one ear and normal hearing in the contralateral ear), normal hearing listening bilaterally, and normal hearing listening unilaterally. Although the normal-hearing-bilateral group scored significantly better and had less performance variability than UHLs on all measures, some UHL participants scored within the range of the normal-hearing-bilateral group on all measures. The normal-hearing participants listening unilaterally had better monosyllabic word understanding than UHLs for words presented on the blocked/deaf side but not the open/hearing side. In contrast, UHLs localized better than the normal-hearing unilateral listeners for stimuli on the open/hearing side but not the blocked/deaf side. This suggests that UHLs had learned strategies for improved localization on the side of the intact ear. The UHL and unilateral normal-hearing participant groups were not significantly different for speech in noise measures. UHL participants with childhood rather than recent hearing loss onset localized significantly better; however, these two groups did not differ for speech recognition in noise. Age at onset in UHL adults appears to affect localization ability differently than understanding speech in noise. Hearing thresholds were significantly correlated with speech recognition for UHL participants but not the other two groups. Auditory abilities of UHLs varied widely and could be explained only in part by hearing threshold levels. Age at onset and length of hearing loss influenced performance on some, but not all measures. Results support the need for a revised and diverse set of clinical measures, including sound localization, understanding speech in varied environments, and careful consideration of functional abilities as individuals with severe to profound UHL are being considered potential cochlear implant candidates.

Developmental differences in intra-individual variability in children with ADHD and ASD.

PubMed

van Belle, Janna; van Hulst, Branko M; Durston, Sarah

2015-12-01

Intra-individual variability reflects temporal variation within an individual's performance on a cognitive task. Children with developmental disorders, such as ADHD and ASD show increased levels of intra-individual variability. In typical development, intra-individual variability decreases sharply between the ages 6 and 20. The tight link between intra-individual variability and age has led to the suggestion that it may be marker of neural development. As there is accumulating evidence that ADHD and ASD are characterised by atypical neurodevelopmental trajectories, we set out to explore developmental changes in intra-individual variability in subjects with ADHD and ASD. We used propensity score matching to match a cross-sectional sample of children with ADHD, ASD and control subjects (N = 405, aged 6-19 years old) for age, IQ and gender. We used ex-Gaussian distribution parameters to characterise intra-individual variability on fast responses (sigma) and slow responses (tau). Results showed that there was a similar decrease in mean response times with age across groups, and an interaction between age and group for measures of variability, where there was a much lower rate of change in the variability parameters (sigma and tau) for subjects with ASD compared with the other two groups. Subjects with ADHD had higher intra-individual variability, reflected by both sigma and tau, but the rate of decrease in variability with age was similar to that of the controls. These results suggest that subjects with ADHD, ASD and controls differ in the rate at which intra-individual variability decreases during development, and support the idea that intra-individual variability may be a marker of neural development, mimicking the neurodevelopmental changes in these disorders. © 2015 Association for Child and Adolescent Mental Health.

Unilateral Hearing Loss: Understanding Speech Recognition and Localization Variability - Implications for Cochlear Implant Candidacy

PubMed Central

Firszt, Jill B.; Reeder, Ruth M.; Holden, Laura K.

2016-01-01

Objectives At a minimum, unilateral hearing loss (UHL) impairs sound localization ability and understanding speech in noisy environments, particularly if the loss is severe to profound. Accompanying the numerous negative consequences of UHL is considerable unexplained individual variability in the magnitude of its effects. Identification of co-variables that affect outcome and contribute to variability in UHLs could augment counseling, treatment options, and rehabilitation. Cochlear implantation as a treatment for UHL is on the rise yet little is known about factors that could impact performance or whether there is a group at risk for poor cochlear implant outcomes when hearing is near-normal in one ear. The overall goal of our research is to investigate the range and source of variability in speech recognition in noise and localization among individuals with severe to profound UHL and thereby help determine factors relevant to decisions regarding cochlear implantation in this population. Design The present study evaluated adults with severe to profound UHL and adults with bilateral normal hearing. Measures included adaptive sentence understanding in diffuse restaurant noise, localization, roving-source speech recognition (words from 1 of 15 speakers in a 140° arc) and an adaptive speech-reception threshold psychoacoustic task with varied noise types and noise-source locations. There were three age-gender-matched groups: UHL (severe to profound hearing loss in one ear and normal hearing in the contralateral ear), normal hearing listening bilaterally, and normal hearing listening unilaterally. Results Although the normal-hearing-bilateral group scored significantly better and had less performance variability than UHLs on all measures, some UHL participants scored within the range of the normal-hearing-bilateral group on all measures. The normal-hearing participants listening unilaterally had better monosyllabic word understanding than UHLs for words presented on the blocked/deaf side but not the open/hearing side. In contrast, UHLs localized better than the normal hearing unilateral listeners for stimuli on the open/hearing side but not the blocked/deaf side. This suggests that UHLs had learned strategies for improved localization on the side of the intact ear. The UHL and unilateral normal hearing participant groups were not significantly different for speech-in-noise measures. UHL participants with childhood rather than recent hearing loss onset localized significantly better; however, these two groups did not differ for speech recognition in noise. Age at onset in UHL adults appears to affect localization ability differently than understanding speech in noise. Hearing thresholds were significantly correlated with speech recognition for UHL participants but not the other two groups. Conclusions Auditory abilities of UHLs varied widely and could be explained only in part by hearing threshold levels. Age at onset and length of hearing loss influenced performance on some, but not all measures. Results support the need for a revised and diverse set of clinical measures, including sound localization, understanding speech in varied environments and careful consideration of functional abilities as individuals with severe to profound UHL are being considered potential cochlear implant candidates. PMID:28067750

Spontaneous Fluctuations in Sensory Processing Predict Within-Subject Reaction Time Variability.

PubMed

Ribeiro, Maria J; Paiva, Joana S; Castelo-Branco, Miguel

2016-01-01

When engaged in a repetitive task our performance fluctuates from trial-to-trial. In particular, inter-trial reaction time variability has been the subject of considerable research. It has been claimed to be a strong biomarker of attention deficits, increases with frontal dysfunction, and predicts age-related cognitive decline. Thus, rather than being just a consequence of noise in the system, it appears to be under the control of a mechanism that breaks down under certain pathological conditions. Although the underlying mechanism is still an open question, consensual hypotheses are emerging regarding the neural correlates of reaction time inter-trial intra-individual variability. Sensory processing, in particular, has been shown to covary with reaction time, yet the spatio-temporal profile of the moment-to-moment variability in sensory processing is still poorly characterized. The goal of this study was to characterize the intra-individual variability in the time course of single-trial visual evoked potentials and its relationship with inter-trial reaction time variability. For this, we chose to take advantage of the high temporal resolution of the electroencephalogram (EEG) acquired while participants were engaged in a 2-choice reaction time task. We studied the link between single trial event-related potentials (ERPs) and reaction time using two different analyses: (1) time point by time point correlation analyses thereby identifying time windows of interest; and (2) correlation analyses between single trial measures of peak latency and amplitude and reaction time. To improve extraction of single trial ERP measures related with activation of the visual cortex, we used an independent component analysis (ICA) procedure. Our ERP analysis revealed a relationship between the N1 visual evoked potential and reaction time. The earliest time point presenting a significant correlation of its respective amplitude with reaction time occurred 175 ms after stimulus onset, just after the onset of the N1 peak. Interestingly, single trial N1 latency correlated significantly with reaction time, while N1 amplitude did not. In conclusion, our findings suggest that inter-trial variability in the timing of extrastriate visual processing contributes to reaction time variability.

Spontaneous Fluctuations in Sensory Processing Predict Within-Subject Reaction Time Variability

PubMed Central

Ribeiro, Maria J.; Paiva, Joana S.; Castelo-Branco, Miguel

2016-01-01

When engaged in a repetitive task our performance fluctuates from trial-to-trial. In particular, inter-trial reaction time variability has been the subject of considerable research. It has been claimed to be a strong biomarker of attention deficits, increases with frontal dysfunction, and predicts age-related cognitive decline. Thus, rather than being just a consequence of noise in the system, it appears to be under the control of a mechanism that breaks down under certain pathological conditions. Although the underlying mechanism is still an open question, consensual hypotheses are emerging regarding the neural correlates of reaction time inter-trial intra-individual variability. Sensory processing, in particular, has been shown to covary with reaction time, yet the spatio-temporal profile of the moment-to-moment variability in sensory processing is still poorly characterized. The goal of this study was to characterize the intra-individual variability in the time course of single-trial visual evoked potentials and its relationship with inter-trial reaction time variability. For this, we chose to take advantage of the high temporal resolution of the electroencephalogram (EEG) acquired while participants were engaged in a 2-choice reaction time task. We studied the link between single trial event-related potentials (ERPs) and reaction time using two different analyses: (1) time point by time point correlation analyses thereby identifying time windows of interest; and (2) correlation analyses between single trial measures of peak latency and amplitude and reaction time. To improve extraction of single trial ERP measures related with activation of the visual cortex, we used an independent component analysis (ICA) procedure. Our ERP analysis revealed a relationship between the N1 visual evoked potential and reaction time. The earliest time point presenting a significant correlation of its respective amplitude with reaction time occurred 175 ms after stimulus onset, just after the onset of the N1 peak. Interestingly, single trial N1 latency correlated significantly with reaction time, while N1 amplitude did not. In conclusion, our findings suggest that inter-trial variability in the timing of extrastriate visual processing contributes to reaction time variability. PMID:27242470

Free will in addictive behaviors: A matter of definition.

PubMed

Cox, W Miles; Klinger, Eric; Fadardi, Javad Salehi

2017-06-01

Certain people are at risk for using alcohol or other drugs excessively and for developing problems with their use. Their susceptibility might arise from a variety of factors, including their genetic make-up, brain chemistry, family background, personality and other psychological variables, and environmental and sociocultural variables. Moreover, after substance use has become established, there are additional cognitive-motivational variables (e.g., substance-related attentional bias) that contribute to enacting behaviors consistent with the person's motivation to acquire and use the substance. People who are at such risk are likely to choose to use addictive substances even though doing so entails negative consequences. In the sense of complete freedom from being determined by causal factors, we believe that there is no such thing as free will, but defined as ability to make choices from among multiple options, even though the choices are ultimately governed by natural processes, addicted individuals are free to choose. Although they might appear unable to exercise this kind of free will in decisions about their substance use, addictive behaviors are ultimately always goal-directed and voluntary. Such goal pursuits manifest considerable flexibility. Even some severely addicted individuals can cease their use when the value of continuing the use abruptly declines or when the subjective cost of continuing the use is too great with respect to the incentives in other areas of their lives. Formal treatment strategies (e.g., contingency management, Systematic Motivational Counseling, cognitive training) can also be used to facilitate this reversal.

[Assessment of factors associated with patients' comprehension of treatment at the start of antiretroviral therapy].

PubMed

Braga Ceccato, Maria das Graças; Acurcio, Francisco de Assis; Vallano, Antonio; Comini César, Cibele; Crosland Guimarães, Mark Drew

2009-01-01

The aim of this study was to evaluate factors associated with patients' comprehension of antiretroviral therapy (ART). Cross-sectional analysis in which patients at 2 HIV/AIDS public referral centers (Belo Horizonte, Brazil) were interviewed after initiating ART. Information was recorded on variables related to the patient's characteristics, the treatment prescribed, and the healthcare professional involved. A score indicating the patients' level of comprehension regarding the medications prescribed was obtained using a latent trait model estimated by the item response theory. A total of 406 patients were interviewed. Mean (SD) age was 35 (10) years, 227 were men (56%), 302 of Afro-American ethnicity (77%), and 213 had <8 years of education (53%). The regression model determined that 52.25% of the variability of comprehension was explained by the individual's characteristics. Variables associated (P<0.05) with poorest understanding about ART were lower education (<8 years), lack of knowledge about treatment duration and clinical severity, inadequate information provided by physicians, inability to understand pharmaceutical information, daily number of tablets, and the ART regimen prescribed. Comprehension of information about the ART regimen prescribed varies considerably between individuals. Nonetheless, several factors were found to be associated with the level of understanding: characteristics of the patient (education, clinical severity), characteristics of treatment (daily number of tablets, ART regimen prescribed), and contribution of healthcare professionals (information from physicians and pharmacists). Strategies to reinforce information about ART should be a priority for patients with a low level of understanding.

The role of impulse parameters in force variability

NASA Technical Reports Server (NTRS)

Carlton, L. G.; Newell, K. M.

1986-01-01

One of the principle limitations of the human motor system is the ability to produce consistent motor responses. When asked to repeatedly make the same movement, performance outcomes are characterized by a considerable amount of variability. This occurs whether variability is expressed in terms of kinetics or kinematics. Variability in performance is of considerable importance because for tasks requiring accuracy it is a critical variable in determining the skill of the performer. What has long been sought is a description of the parameter or parameters that determine the degree of variability. Two general experimental protocals were used. One protocal is to use dynamic actions and record variability in kinematic parameters such as spatial or temporal error. A second strategy was to use isometric actions and record kinetic variables such as peak force produced. What might be the important force related factors affecting variability is examined and an experimental approach to examine the influence of each of these variables is provided.

Anabolic Heterogeneity Following Resistance Training: A Role for Circadian Rhythm?

PubMed

Camera, Donny M

2018-01-01

It is now well established that resistance exercise stimulates muscle protein synthesis and promotes gains in muscle mass and strength. However, considerable variability exists following standardized resistance training programs in the magnitude of muscle cross-sectional area and strength responses from one individual to another. Several studies have recently posited that alterations in satellite cell population, myogenic gene expression and microRNAs may contribute to individual variability in anabolic adaptation. One emerging factor that may also explain the variability in responses to resistance exercise is circadian rhythms and underlying molecular clock signals. The molecular clock is found in most cells within the body, including skeletal muscle, and principally functions to optimize the timing of specific cellular events around a 24 h cycle. Accumulating evidence investigating the skeletal muscle molecular clock indicates that exercise-induced contraction and its timing may regulate gene expression and protein synthesis responses which, over time, can influence and modulate key physiological responses such as muscle hypertrophy and increased strength. Therefore, the circadian clock may play a key role in the heterogeneous anabolic responses with resistance exercise. The central aim of this Hypothesis and Theory is to discuss and propose the potential interplay between the circadian molecular clock and established molecular mechanisms mediating muscle anabolic responses with resistance training. This article begins with a current review of the mechanisms associated with the heterogeneity in muscle anabolism with resistance training before introducing the molecular pathways regulating circadian function in skeletal muscle. Recent work showing members of the core molecular clock system can regulate myogenic and translational signaling pathways is also discussed, forming the basis for a possible role of the circadian clock in the variable anabolic responses with resistance exercise.

Neuronal variability in orbitofrontal cortex during economic decisions.

PubMed

Conen, Katherine E; Padoa-Schioppa, Camillo

2015-09-01

Neuroeconomic models assume that economic decisions are based on the activity of offer value cells in the orbitofrontal cortex (OFC), but testing this assertion has proven difficult. In principle, the decision made on a given trial should correlate with the stochastic fluctuations of these cells. However, this correlation, measured as a choice probability (CP), is small. Importantly, a neuron's CP reflects not only its individual contribution to the decision (termed readout weight), but also the intensity and the structure of correlated variability across the neuronal population (termed noise correlation). A precise mathematical relation between CPs, noise correlations, and readout weights was recently derived by Haefner and colleagues (Haefner RM, Gerwinn S, Macke JH, Bethge M. Nat Neurosci 16: 235-242, 2013) for a linear decision model. In this framework, concurrent measurements of noise correlations and CPs can provide quantitative information on how a population of cells contributes to a decision. Here we examined neuronal variability in the OFC of rhesus monkeys during economic decisions. Noise correlations had similar structure but considerably lower strength compared with those typically measured in sensory areas during perceptual decisions. In contrast, variability in the activity of individual cells was high and comparable to that recorded in other cortical regions. Simulation analyses based on Haefner's equation showed that noise correlations measured in the OFC combined with a plausible readout of offer value cells reproduced the experimental measures of CPs. In other words, the results obtained for noise correlations and those obtained for CPs taken together support the hypothesis that economic decisions are primarily based on the activity of offer value cells. Copyright © 2015 the American Physiological Society.

Contribution of competition for light to within-species variability in stomatal conductance

NASA Astrophysics Data System (ADS)

Loranty, Michael M.; Mackay, D. Scott; Ewers, Brent E.; Traver, Elizabeth; Kruger, Eric L.

2010-05-01

Sap flux (JS) measurements were collected across two stands dominated by either trembling aspen or sugar maple in northern Wisconsin. Observed canopy transpiration (EC-obs) values derived from JS were used to parameterize the Terrestrial Regional Ecosystem Exchange Simulator ecosystem model. Modeled values of stomatal conductance (GS) were used to determine reference stomatal conductance (GSref), a proxy for GS that removes the effects of temporal responses to vapor pressure deficit (D) on spatial patterns of GS. Values of GSref were compared to observations of soil moisture, several physiological variables, and a competition index (CI) derived from a stand inventory, to determine the underlying cause of observed variability. Considerable variability in GSref between individual trees was found, with values ranging from 20 to 200 mmol m-2 s-1 and 20 to 100 mmol m-2 s-1 at the aspen and maple stands, respectively. Model-derived values of GSref and a sensitivity to D parameter (m) showed good agreement with a known empirical relationship for both stands. At both sites, GSref did not vary with topographic position, as indicated by surface soil moisture. No relationships were observed between GSref and tree height (HT), and a weak correlation with sapwood area (AS) was only significant for aspen. Significant nonlinear inverse relationships between GSref and CI were observed at both stands. Simulations with uniform reductions in incident photosynthetically active radiation (Q0) resulted in better agreement between observed and simulated EC. Our results suggest a link between photosynthesis and plant hydraulics whereby individual trees subject to photosynthetic limitation as a result of competitive shading exhibit a dynamic stomatal response resulting in a more conservative strategy for managing hydrologic resources.

Alcohol-Related Negative Consequences among Drinkers around the World

PubMed Central

Graham, Kathryn; Bernards, Sharon; Knibbe, Ronald; Kairouz, Sylvia; Kuntche, Sandra; Wilsnack, Sharon C.; Greenfield, Thomas K.; Dietze, Paul; Obot, Isidore; Gmel, Gerhard

2013-01-01

Aims This paper examines (1) gender and country differences in negative consequences related to drinking; (2) relative rates of different consequences; (3) country-level predictors of consequences. Design, setting and participants Multi-level analyses used survey data from the GENACIS collaboration. Measurements Measures included 17 negative consequences grouped into (a) high endorsement acute, (b) personal and (c) social. Country-level measures included average frequency and quantity of drinking, percent current drinkers, Gross Domestic Product (GDP) and Human Development Index (HDI). Findings Overall, the three groupings of consequences were reported by 44%, 12% and 7% of men and by 31%, 6% and 3% of women, respectively. More men than women endorsed all consequences but gender differences were greatest for consequences associated with chronic drinking and social consequences related to male roles. The highest prevalence of consequences was in Uganda, lowest in Uruguay. Personal and social consequences were more likely in countries with higher usual quantity, fewer current drinkers, and lower scores on GDP and HDI. However, significant interactions with individual-level quantity indicated a stronger relationship between consequences and usual quantity among drinkers in countries with lower quantity, more current drinkers and higher scores on GDP and HDI. Conclusions Both gender and country need to be taken into consideration when assessing adverse drinking consequences. Individual measures of alcohol consumption and country-level variables are associated with experiencing such consequences. Additionally, country-level variables affect the strength of the relationship between usual quantity consumed by individuals and adverse consequences. PMID:21395893

Laser system refinements to reduce variability in infarct size in the rat photothrombotic stroke model

PubMed Central

Alaverdashvili, Mariam; Paterson, Phyllis G.; Bradley, Michael P.

2015-01-01

Background The rat photothrombotic stroke model can induce brain infarcts with reasonable biological variability. Nevertheless, we observed unexplained high inter-individual variability despite using a rigorous protocol. Of the three major determinants of infarct volume, photosensitive dye concentration and illumination period were strictly controlled, whereas undetected fluctuation in laser power output was suspected to account for the variability. New method The frequently utilized Diode Pumped Solid State (DPSS) lasers emitting 532 nm (green) light can exhibit fluctuations in output power due to temperature and input power alterations. The polarization properties of the Nd:YAG and Nd:YVO4 crystals commonly used in these lasers are another potential source of fluctuation, since one means of controlling output power uses a polarizer with a variable transmission axis. Thus, the properties of DPSS lasers and the relationship between power output and infarct size were explored. Results DPSS laser beam intensity showed considerable variation. Either a polarizer or a variable neutral density filter allowed adjustment of a polarized laser beam to the desired intensity. When the beam was unpolarized, the experimenter was restricted to using a variable neutral density filter. Comparison with existing method(s) Our refined approach includes continuous monitoring of DPSS laser intensity via beam sampling using a pellicle beamsplitter and photodiode sensor. This guarantees the desired beam intensity at the targeted brain area during stroke induction, with the intensity controlled either through a polarizer or variable neutral density filter. Conclusions Continuous monitoring and control of laser beam intensity is critical for ensuring consistent infarct size. PMID:25840363

Mapping U.S. government tobacco control leadership: networked for success?

PubMed

Leischow, Scott J; Luke, Douglas A; Mueller, Nancy; Harris, Jenine K; Ponder, Paris; Marcus, Stephen; Clark, Pamela I

2010-09-01

In order to better understand how tobacco control efforts are coordinated across agencies of the Department of Health and Human Services (DHHS), we assessed tobacco control-related communication between tobacco control leaders across DHHS. Cross-sectional surveys were collected from individuals representing 11 DHHS agencies, and social network analyses were used to assess linkages and map agencies' tobacco control communication. Individuals within the Office of the Secretary and Centers for Disease Control and Prevention (CDC) were most central to the network, and those of highest rank were most likely to be central to the network (F = 4.03, p = .024). The Centers for Medicare and Medicaid Services, Food and Drug Administration, Health Resources and Services Administration, and Substance Abuse and Mental Health Services Administration had no or almost no contact with other agencies. There was considerable between-agency contact variability, and the CDC was the most central agency. Tobacco control communication across DHHS agencies was present but extremely variable. This inconsistency may compromise the ability of the DHHS to address tobacco use, a critical public health problem, in a coordinated and efficient fashion. In light of the new leadership at DHHS, this analysis describes a systems approach that can be reimplemented as a means of understanding and improving communication and collaboration to improve public health.

No Evidence of the Ego-Depletion Effect across Task Characteristics and Individual Differences: A Pre-Registered Study

PubMed Central

Lurquin, John H.; Michaelson, Laura E.; Barker, Jane E.; Gustavson, Daniel E.; von Bastian, Claudia C.; Carruth, Nicholas P.; Miyake, Akira

2016-01-01

Ego-depletion, a psychological phenomenon in which participants are less able to engage in self-control after prior exertion of self-control, has become widely popular in the scientific community as well as in the media. However, considerable debate exists among researchers as to the nature of the ego-depletion effect, and growing evidence suggests the effect may not be as strong or robust as the extant literature suggests. We examined the robustness of the ego-depletion effect and aimed to maximize the likelihood of detecting the effect by using one of the most widely used depletion tasks (video-viewing attention control task) and by considering task characteristics and individual differences that potentially moderate the effect. We also sought to make our research plan transparent by pre-registering our hypotheses, procedure, and planned analyses prior to data collection. Contrary to the ego-depletion hypothesis, participants in the depletion condition did not perform worse than control participants on the subsequent self-control task, even after considering moderator variables. These findings add to a growing body of evidence suggesting ego-depletion is not a reliable phenomenon, though more research is needed that uses large sample sizes, considers moderator variables, and pre-registers prior to data collection. PMID:26863227

Analysis of caries status development in relation to socio-economic variables using a case-based system.

PubMed

Swedberg, Y; Norén, J G

2001-01-01

The aim of this study was to detect, using case-based reasoning (CBR) induction methods in time series analysis, how measurable socio-economical adjustments were related to the caries status development. The study concerned the year classes leaving the organised dental care for the time period 1987-95, and had received dental care at the Public Dental Service of Göteborg. The results, as presented by a caries incidence index, indicated that at least one socioeconomical factor, individuals seeking employment, was of importance for the caries status development, a factor with an increase of considerable proportions since 1990. The findings indicated that the other socio-economic variables used did not have the same importance for the caries status development. One feasible explanation is that these factors reflect more upon the social family situation than the economical. If the caries status reflects the social situation of the individual more than the economical, this argument will elucidate the reasoning. Using CBR for the analysis of relationships between oral disease and parameters possibly influencing health development has proven to be a valuable tool and complement to more traditional statistical methods. The analysis can make relationships explicit through the hierarchic knowledge trees and also show redundant information, attributes not appearing in the trees.

Optical investigation of variability in body region dependent transcutaneous oxygen saturation

NASA Astrophysics Data System (ADS)

Philimon, Sheena P.; Huong, Audrey K. C.; Hafizah, W. M.; Ong, P. E.; Ngu, Xavier T. I.

2016-11-01

This paper presents the use of multispectral imaging system to investigate variability in transcutaneous oxygen saturation (StO2) amongst different individuals and at different skin sites. Noncontact reflectance data are collected from central forehead, posterior forearm, thenar region of palm and proximal ankle of three healthy Asians. The prediction of the required StO2 value is via fitting Extended Modified Lambert (EMLB) model to the measured attenuation data using extinction coefficient of hemoglobin components in the wavelength range of 520 - 600 nm as its priori knowledge. The obtained results revealed a relatively high mean StO2 of 54 ± 1.9% at the palm of the hand site. This is followed by measurement at foot ankle and forehead with StO2 of 52.3 ± 2.4% and 51.2 ± 7.7%, respectively. Meanwhile the lowest reading of StO2 of 48.8 ± 5.1% is observed at the posterior forearm. Based on these findings, this work concluded that palm of the hand would provide considerably consistent measurement of StO2 among individuals. This is largely owing to the higher density of circulatory anastomosis at this skin site. This implied viability of using the developed strategy in the studies of microcirculation mechanism especially on wound at this skin region.

No Evidence of the Ego-Depletion Effect across Task Characteristics and Individual Differences: A Pre-Registered Study.

PubMed

Lurquin, John H; Michaelson, Laura E; Barker, Jane E; Gustavson, Daniel E; von Bastian, Claudia C; Carruth, Nicholas P; Miyake, Akira

2016-01-01

Ego-depletion, a psychological phenomenon in which participants are less able to engage in self-control after prior exertion of self-control, has become widely popular in the scientific community as well as in the media. However, considerable debate exists among researchers as to the nature of the ego-depletion effect, and growing evidence suggests the effect may not be as strong or robust as the extant literature suggests. We examined the robustness of the ego-depletion effect and aimed to maximize the likelihood of detecting the effect by using one of the most widely used depletion tasks (video-viewing attention control task) and by considering task characteristics and individual differences that potentially moderate the effect. We also sought to make our research plan transparent by pre-registering our hypotheses, procedure, and planned analyses prior to data collection. Contrary to the ego-depletion hypothesis, participants in the depletion condition did not perform worse than control participants on the subsequent self-control task, even after considering moderator variables. These findings add to a growing body of evidence suggesting ego-depletion is not a reliable phenomenon, though more research is needed that uses large sample sizes, considers moderator variables, and pre-registers prior to data collection.

Inhibitory activity of aspirin on von Willebrand factor-induced platelet aggregation.

PubMed

Homoncik, M; Jilma, B; Eichelberger, B; Panzer, S

2000-09-01

The effect of aspirin (ASA) on vWF induced platelet - platelet interaction is unknown. We therefore tested the response of platelets to von Willebrand factor (vWF) coated beads induced platelet aggregation before and after i.v. and oral ASA. 1000 mg ASA was infused to 10 healthy individuals and after a wash-out period 7 volunteers received 100 mg ASA orally over a period of 11 days. Prior to ASA and in regular intervals thereafter we tested the reactivity to vWF-coated beads to assess platelet adhesion/aggregation and the fade-out time of ASA effects on platelets. Considerable interindividual variability in response to vWF-coated beads was observed, both before ASA and after treatment with ASA. The maximal response to vWF-coated beads (Tmax), the time lag, and the slope of the curve were significantly affected by i.v. ASA, whereas 100 mg of ASA had only inconstant effect on Tmax and slope. The absolute reduction of Tmax after ASA depended on the pre-ASA level, while the percentage of the reduction was similar in all individuals. Thus, platelet aggregation induced by vWF-coated beads is impaired by ASA. Furthermore, our data indicate a large interindividual variability of the response to ASA shortly after treatment induction, which becomes more constant after prolonged treatment.

A sensitive cytochemical staining method for glucose-6-phosphate dehydrogenase activity in individual erythrocytes. II. Further improvements of the staining procedure and some observations with glucose-6-phosphate dehydrogenase deficiency.

PubMed

Van Noorden, C J; Vogels, I M

1985-05-01

A cytochemical method for staining glucose-6-phosphate dehydrogenase (G6PD) activity in individual erythrocytes as reported previously has been optimized further by the incorporation of a number of technical improvements. Analysis of the enzyme content in erythrocytes of normal individuals as well as patients suffering from G6PD deficiency in the homozygous and heterozygous forms allows these three categories to be easily distinguished. Considerable formazan production occurs in most erythrocytes of a healthy person and only a small percentage of the cells appeared to be negative. Two cell populations of almost equal size could be discerned in heterozygotes for G6PD deficiency, one completely negative, the other with a variable amount of formazan per cell. Homozygous deficiency leads to a population of negative cells with a few positive ones after staining. It is concluded that a reliable method has been found for analysis of G6PD deficiency in erythrocytes at the single cell level.

Parenting dimensions and styles: a brief history and recommendations for future research.

PubMed

Power, Thomas G

2013-08-01

Over the last decade, researchers have uncovered relationships between general parenting styles and children's obesity. This is an emerging area of research, and there currently is a great deal of interest in the parent's role. This review was written to provide researchers entering this area with a historical introduction to parenting research and to point to some directions for future inquiry. Over the last 75 years, considerable insight has been gained into individual differences in parenting behavior, especially regarding the dimensions underlying individual differences in general parenting approach, and parenting styles resulting from individual differences on these dimensions. The history of empirical attempts to identify parenting dimensions and styles is reviewed briefly, followed by a review of more recent studies of parenting styles. Next is a discussion of data analytic approaches to measuring parenting, with a particular emphasis on variable-centered versus person-centered approaches. Because investigators have often disagreed about which of these approaches is the most appropriate, the advantages and disadvantages of each are considered, along with recommendations for future research.

Parenting Dimensions and Styles: A Brief History and Recommendations for Future Research

PubMed Central

2013-01-01

Abstract Over the last decade, researchers have uncovered relationships between general parenting styles and children's obesity. This is an emerging area of research, and there currently is a great deal of interest in the parent's role. This review was written to provide researchers entering this area with a historical introduction to parenting research and to point to some directions for future inquiry. Over the last 75 years, considerable insight has been gained into individual differences in parenting behavior, especially regarding the dimensions underlying individual differences in general parenting approach, and parenting styles resulting from individual differences on these dimensions. The history of empirical attempts to identify parenting dimensions and styles is reviewed briefly, followed by a review of more recent studies of parenting styles. Next is a discussion of data analytic approaches to measuring parenting, with a particular emphasis on variable-centered versus person-centered approaches. Because investigators have often disagreed about which of these approaches is the most appropriate, the advantages and disadvantages of each are considered, along with recommendations for future research. PMID:23944920

Midsagittal brain variation and MRI shape analysis of the precuneus in adult individuals.

PubMed

Bruner, Emiliano; Rangel de Lázaro, Gizéh; de la Cuétara, José Manuel; Martín-Loeches, Manuel; Colom, Roberto; Jacobs, Heidi I L

2014-04-01

Recent analyses indicate that the precuneus is one of the main centres of integration in terms of functional and structural processes within the human brain. This neuroanatomical element is formed by different subregions, involved in visuo-spatial integration, memory and self-awareness. We analysed the midsagittal brain shape in a sample of adult humans (n = 90) to evidence the patterns of variability and geometrical organization of this area. Interestingly, the major brain covariance pattern within adult humans is strictly associated with the relative proportions of the precuneus. Its morphology displays a marked individual variation, both in terms of geometry (mostly in its longitudinal dimensions) and anatomy (patterns of convolution). No patent differences are evident between males and females, and the allometric effect of size is minimal. However, in terms of morphology, the precuneus does not represent an individual module, being influenced by different neighbouring structures. Taking into consideration the apparent involvement of the precuneus in higher-order human brain functions and evolution, its wide variation further stresses the important role of these deep parietal areas in modern neuroanatomical organization. © 2014 Anatomical Society.

MobRISK: a model for assessing the exposure of road users to flash flood events

NASA Astrophysics Data System (ADS)

Shabou, Saif; Ruin, Isabelle; Lutoff, Céline; Debionne, Samuel; Anquetin, Sandrine; Creutin, Jean-Dominique; Beaufils, Xavier

2017-09-01

Recent flash flood impact studies highlight that road networks are often disrupted due to adverse weather and flash flood events. Road users are thus particularly exposed to road flooding during their daily mobility. Previous exposure studies, however, do not take into consideration population mobility. Recent advances in transportation research provide an appropriate framework for simulating individual travel-activity patterns using an activity-based approach. These activity-based mobility models enable the prediction of the sequence of activities performed by individuals and locating them with a high spatial-temporal resolution. This paper describes the development of the MobRISK microsimulation system: a model for assessing the exposure of road users to extreme hydrometeorological events. MobRISK aims at providing an accurate spatiotemporal exposure assessment by integrating travel-activity behaviors and mobility adaptation with respect to weather disruptions. The model is applied in a flash-flood-prone area in southern France to assess motorists' exposure to the September 2002 flash flood event. The results show that risk of flooding mainly occurs in principal road links with considerable traffic load. However, a lag time between the timing of the road submersion and persons crossing these roads contributes to reducing the potential vehicle-related fatal accidents. It is also found that sociodemographic variables have a significant effect on individual exposure. Thus, the proposed model demonstrates the benefits of considering spatiotemporal dynamics of population exposure to flash floods and presents an important improvement in exposure assessment methods. Such improved characterization of road user exposures can present valuable information for flood risk management services.

Unity and diversity of executive functions: Individual differences as a window on cognitive structure.

PubMed

Friedman, Naomi P; Miyake, Akira

2017-01-01

Executive functions (EFs) are high-level cognitive processes, often associated with the frontal lobes, that control lower level processes in the service of goal-directed behavior. They include abilities such as response inhibition, interference control, working memory updating, and set shifting. EFs show a general pattern of shared but distinct functions, a pattern described as "unity and diversity". We review studies of EF unity and diversity at the behavioral and genetic levels, focusing on studies of normal individual differences and what they reveal about the functional organization of these cognitive abilities. In particular, we review evidence that across multiple ages and populations, commonly studied EFs (a) are robustly correlated but separable when measured with latent variables; (b) are not the same as general intelligence or g; (c) are highly heritable at the latent level and seemingly also highly polygenic; and (d) activate both common and specific neural areas and can be linked to individual differences in neural activation, volume, and connectivity. We highlight how considering individual differences at the behavioral and neural levels can add considerable insight to the investigation of the functional organization of the brain, and conclude with some key points about individual differences to consider when interpreting neuropsychological patterns of dissociation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modelling personality, plasticity and predictability in shelter dogs

PubMed Central

2017-01-01

Behavioural assessments of shelter dogs (Canis lupus familiaris) typically comprise standardized test batteries conducted at one time point, but test batteries have shown inconsistent predictive validity. Longitudinal behavioural assessments offer an alternative. We modelled longitudinal observational data on shelter dog behaviour using the framework of behavioural reaction norms, partitioning variance into personality (i.e. inter-individual differences in behaviour), plasticity (i.e. inter-individual differences in average behaviour) and predictability (i.e. individual differences in residual intra-individual variation). We analysed data on interactions of 3263 dogs (n = 19 281) with unfamiliar people during their first month after arrival at the shelter. Accounting for personality, plasticity (linear and quadratic trends) and predictability improved the predictive accuracy of the analyses compared to models quantifying personality and/or plasticity only. While dogs were, on average, highly sociable with unfamiliar people and sociability increased over days since arrival, group averages were unrepresentative of all dogs and predictions made at the individual level entailed considerable uncertainty. Effects of demographic variables (e.g. age) on personality, plasticity and predictability were observed. Behavioural repeatability was higher one week after arrival compared to arrival day. Our results highlight the value of longitudinal assessments on shelter dogs and identify measures that could improve the predictive validity of behavioural assessments in shelters. PMID:28989764

[Caesarean sections in Mexico: tendencies, levels and associated factors].

PubMed

Puentes-Rosas, Esteban; Gómez-Dantés, Octavio; Garrido-Latorre, Francisco

2004-01-01

To describe the rate of caesarean sections in Mexico in the last 10 years and evaluate its relationship with several socioeconomic variables, type of health care services, and specialists' availability. The Ministry of Health's register of births was used as source of information. The dependent variable was the type of delivery (vaginal or caesarean). The independent variables were: gross domestic product, human development index, illiteracy percentage among women, social exclusion index and, gynecology and obstetrics specialists supply. Correlations between variables were evaluated using Pearson's parametric test and Spearman range test. A lineal multiple regression was used to model the national caesarean data of 1999. National caesarean percentage increased in the last 10 years at an annual rate of 1%. It was considerably higher in social security institutions and the private sector. Caesareans percentages in 1999 were slightly above 35%. The highest values were those of the private sector with 53%, followed by social security institutions, with 38.2%. The variables more strongly associated with C sections were GDP, specialists' availability and human development index. It seems reasonable to advocate for a widespread descent in caesarean sections in Mexico. Important declines in certain contexts have been witnessed by implementing measures such as a second opinion before any C-section, a precise definition of the reasons for using it, and the monitoring of individual caesarean percentage among hospital obstetricians.

Linking Inter-Individual Variability in Functional Brain Connectivity to Cognitive Ability in Elderly Individuals

PubMed Central

Li, Rui; Yin, Shufei; Zhu, Xinyi; Ren, Weicong; Yu, Jing; Wang, Pengyun; Zheng, Zhiwei; Niu, Ya-Nan; Huang, Xin; Li, Juan

2017-01-01

Increasing evidence suggests that functional brain connectivity is an important determinant of cognitive aging. However, the fundamental concept of inter-individual variations in functional connectivity in older individuals is not yet completely understood. It is essential to evaluate the extent to which inter-individual variability in connectivity impacts cognitive performance at an older age. In the current study, we aimed to characterize individual variability of functional connectivity in the elderly and to examine its significance to individual cognition. We mapped inter-individual variability of functional connectivity by analyzing whole-brain functional connectivity magnetic resonance imaging data obtained from a large sample of cognitively normal older adults. Our results demonstrated a gradual increase in variability in primary regions of the visual, sensorimotor, and auditory networks to specific subcortical structures, particularly the hippocampal formation, and the prefrontal and parietal cortices, which largely constitute the default mode and fronto-parietal networks, to the cerebellum. Further, the inter-individual variability of the functional connectivity correlated significantly with the degree of cognitive relevance. Regions with greater connectivity variability demonstrated more connections that correlated with cognitive performance. These results also underscored the crucial function of the long-range and inter-network connections in individual cognition. Thus, individual connectivity–cognition variability mapping findings may provide important information for future research on cognitive aging and neurocognitive diseases. PMID:29209203

Investigating Inter-Individual Differences in Short-Term Intra-Individual Variability

ERIC Educational Resources Information Center

Wang, Lijuan; Hamaker, Ellen; Bergeman, C. S.

2012-01-01

Intra-individual variability over a short period of time may contain important information about how individuals differ from each other. In this article we begin by discussing diverse indicators for quantifying intra-individual variability and indicate their advantages and disadvantages. Then we propose an alternative method that models…

Vaccine stabilization: research, commercialization, and potential impact.

PubMed

Kristensen, Debra; Chen, Dexiang; Cummings, Ray

2011-09-22

All vaccines are susceptible to damage by elevated temperatures and many are also damaged by freezing. The distribution, storage, and use of vaccines therefore present challenges that could be reduced by enhanced thermostability, with resulting improvements in vaccine effectiveness. Formulation and processing technologies exist that can improve the stability of vaccines at temperature extremes, however, customization is required for individual vaccines and results are variable. Considerations affecting decisions about stabilization approaches include development cost, manufacturing cost, and the ease of use of the final product. Public sector agencies can incentivize vaccine developers to prioritize stabilization efforts through advocacy and by implementing policies that increase demand for thermostable vaccines. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

Lopez, M.; Torres, L.; Cervantes, A.

Most individuals with the rare 46,XX male {open_quotes}syndrome{close_quotes} arise due to an unequal interchange between Xp and Yp termini during paternal meiosis. The pattern of Y-sequences in these patients varies considerably, but very few cases have been reported showing only SRY. The phenotype in these patients is also variable ranging from severe impairment of the external genitalia through hypospadias and/or cryptorchidism to occasional normal male phenotype. We report a Mexican 46,XX male patient without genital ambiguities in whom DNA analysis showed the presence of SRY and the absence of ZFY. We conclude that in this case SRY alone was enoughmore » for complete male sexual differentiation. 25 refs., 1 fig.« less

Posttraumatic Stress Disorder: Five Vicious Cycles that Inhibit Effective Treatment.

PubMed

Ghaffarzadegan, Navid; Larson, Richard C

2015-01-01

Despite a wide range of studies and medical progress, it seems that we are far from significantly mitigating the problem of posttraumatic stress disorder (PTSD). The problem has major social and behavioral components. Developing innovative and effective policies requires a broad scope of analysis and consideration of the highly interconnected social, behavioral, and medical variables. In this article, we take a systems approach and offer an illustrative causal loop diagram which includes individual and social dynamics. Based on the map, we discuss 5 major barriers for effective interventions in PTSD. These barriers work as vicious cycles in the system, reduce effectiveness and therefore value of PTSD treatment. We also discuss policy implications of this perspective.

Cell communities and robustness in development.

PubMed

Monk, N A

1997-11-01

The robustness of patterning events in development is a key feature that must be accounted for in proposed models of these events. When considering explicitly cellular systems, robustness can be exhibited at different levels of organization. Consideration of two widespread patterning mechanisms suggests that robustness at the level of cell communities can result from variable development at the level of individual cells; models of these mechanisms show how interactions between participating cells guarantee community-level robustness. Cooperative interactions enhance homogeneity within communities of like cells and the sharpness of boundaries between communities of distinct cells, while competitive interactions amplify small inhomogeneities within communities of initially equivalent cells, resulting in fine-grained patterns of cell specialization.

On the variability of alligator sex ratios

USGS Publications Warehouse

Nichols, J.D.; Chabreck, R.H.

1980-01-01

Samples of alligators from wild and 'farm' populations exhibited disproportionate sex ratios. Males predominated among young alligators from wild populations, whereas females were much more abundant than males in the farm population, where resources were superabundant. These results and other considerations lead us to hypothesize that environmental factors influence sex determination in alligators. During favorable environmental conditions natural selection is expected to favor a preponderance of the sex whose individuals exhibit the greater environmentally associated variation in relative fitness. We hypothesize that environmentally associated variation in age at sexual maturity of females produces sufficient variation in relative fitness of females to result in selection for low sex ratios during periods of resource abundance.

Lead exposure of the child population in Greece.

PubMed

Maravelias, C; Athanaselis, S; Poulos, L; Alevisopoulos, G; Ewers, U; Koutselinis, A

1994-12-18

Lead exposure of the child population was studied in three different areas in Greece: Kalamata which is a rural area of Southern Greece; Tavros, a district of Athens with a considerable industrial activity; and Lavrion, a small city near Athens where a lead-zinc mining and smelting industrial complex has existed for more than 90 years. The results were evaluated with respect to a number of individual, social and environmental variables (i.e. smelter, occupation of the father) especially those concerning the area of Lavrion which is the most heavily polluted area in Greece. The results of this study can be considered as an index for the extent of the lead pollution problem in the named areas of Greece.

Monitoring needs and goal-directed fluid therapy within an enhanced recovery program.

PubMed

Minto, Gary; Scott, Michael J; Miller, Timothy E

2015-03-01

Patients having major abdominal surgery need perioperative fluid supplementation; however, enhanced recovery principles mitigate against many of the factors that traditionally led to relative hypovolemia in the perioperative period. An estimate of fluid requirements for abdominal surgery can be made but individualization of fluid prescription requires consideration of clinical signs and hemodynamic variables. The literature supports goal-directed fluid therapy. Application of this evidence to justify stroke volume optimization in the setting of major surgery within an enhanced recovery program is controversial. This article places the evidence in context, reviews controversies, and suggests implications for current practice and future research. Copyright © 2015 Elsevier Inc. All rights reserved.

Relating residue in raccoon feces to food consumed

USGS Publications Warehouse

Greenwood, R.J.

1979-01-01

Feeding tests were conducted with captive raccoons (Procyon lotor) to permit more meaningful interpretation of food habit data obtained from fecal analysis. Ten diverse types of natural foods were offered in 20 tests. Digestibility coefficients were calculated that ranged from 3.6 for dry sunflowers, where considerable residue was recovered, to infinity for earthworms and boned meat where no residue was recovered. The influence of differences in both food and animal behavior on digestibility coefficients was significant (ANOVA, F<0.001). The use of digestibility coefficients to adjust quantitative estimates of fecal residue or to predict biomass consumed is of questionable value with raccoons due to variability in foods consumed and behavior of individual animals.

LandScape: a simple method to aggregate p-values and other stochastic variables without a priori grouping.

PubMed

Wiuf, Carsten; Schaumburg-Müller Pallesen, Jonatan; Foldager, Leslie; Grove, Jakob

2016-08-01

In many areas of science it is custom to perform many, potentially millions, of tests simultaneously. To gain statistical power it is common to group tests based on a priori criteria such as predefined regions or by sliding windows. However, it is not straightforward to choose grouping criteria and the results might depend on the chosen criteria. Methods that summarize, or aggregate, test statistics or p-values, without relying on a priori criteria, are therefore desirable. We present a simple method to aggregate a sequence of stochastic variables, such as test statistics or p-values, into fewer variables without assuming a priori defined groups. We provide different ways to evaluate the significance of the aggregated variables based on theoretical considerations and resampling techniques, and show that under certain assumptions the FWER is controlled in the strong sense. Validity of the method was demonstrated using simulations and real data analyses. Our method may be a useful supplement to standard procedures relying on evaluation of test statistics individually. Moreover, by being agnostic and not relying on predefined selected regions, it might be a practical alternative to conventionally used methods of aggregation of p-values over regions. The method is implemented in Python and freely available online (through GitHub, see the Supplementary information).

Individual thermal profiles as a basis for comfort improvement in space and other environments

NASA Technical Reports Server (NTRS)

Koscheyev, V. S.; Coca, A.; Leon, G. R.; Dancisak, M. J.

2002-01-01

BACKGROUND: The development of individualized countermeasures to address problems in thermoregulation is of considerable importance for humans in space and other extreme environments. A methodology is presented for evaluating minimal/maximal heat flux from the total human body and specific body zones, and for assessing individual differences in the efficiency of heat exchange from these body areas. The goal is to apply this information to the design of individualized protective equipment. METHODS: A multi-compartment conductive plastic tubing liquid cooling/warming garment (LCWG) was developed. Inlet water temperatures of 8-45 degrees C were imposed sequentially to specific body areas while the remainder of the garment was maintained at 33 degrees C. RESULTS: There were significant differences in heat exchange level among body zones in both the 8 degrees and 45 degrees C temperature conditions (p < 0.001). The greatest amount of heat was absorbed/released by the following areas: thighs (8 degrees C: -2.12 +/- 0.14 kcal min(-1); 45 degrees C: +1.58 +/- 0.23); torso (8 degrees C: -2.12 +/- 0.13 kcal min(-1); 45 degrees C: +1.31 +/- 0.27); calves (8 degrees C: -1.59 +/- 0.26 kcal min(-1); 45 degrees C: +1.53 +/- 0.24); and forearms (8 degrees C: -1.67 +/- 0.29 kcal x min(-1); 45 degrees C: +1.45 +/- 0.20). These are primarily zones with relatively large muscle mass and adipose tissue. Calculation of absorption/release heat rates standardized per unit tube length and flow rate instead of zonal surface area covered showed that there was significantly greater heat transfer in the head, hands, and feet (p < 0.001). The areas in which there was considerable between-subject variability in rates of heat transfer and thus most informative for individual profile design were the torso, thighs, shoulders, and calves or forearms. CONCLUSIONS: The methodology developed is sensitive to individual differences in the process of heat exchange and variations in different body areas, depending on their size and tissue mass content. The design of individual thermal profiles is feasible for better comfort of astronauts on long-duration missions and personnel in other extreme environments.

The process of cognitive behaviour therapy for chronic fatigue syndrome: which changes in perpetuating cognitions and behaviour are related to a reduction in fatigue?

PubMed

Heins, Marianne J; Knoop, Hans; Burk, William J; Bleijenberg, Gijs

2013-09-01

Cognitive behaviour therapy (CBT) can significantly reduce fatigue in chronic fatigue syndrome (CFS), but little is known about the process of change taking place during CBT. Based on a recent treatment model (Wiborg et al. J Psych Res 2012), we examined how (changes in) cognitions and behaviour are related to the decrease in fatigue. We included 183 patients meeting the US Centers for Disease Control criteria for CFS, aged 18 to 65 years, starting CBT. We measured fatigue and possible process variables before treatment; after 6, 12 and 18 weeks; and after treatment. Possible process variables were sense of control over fatigue, focusing on symptoms, self-reported physical functioning, perceived physical activity and objective (actigraphic) physical activity. We built multiple regression models, explaining levels of fatigue during therapy by (changes in) proposed process variables. We observed large individual variation in the patterns of change in fatigue and process variables during CBT for CFS. Increases in the sense of control over fatigue, perceived activity and self-reported physical functioning, and decreases in focusing on symptoms explained 20 to 46% of the variance in fatigue. An increase in objective activity was not a process variable. A change in cognitive factors seems to be related to the decrease in fatigue during CBT for CFS. The pattern of change varies considerably between patients, but changes in process variables and fatigue occur mostly in the same period. © 2013.

Age-associated and deslorelin-induced declines in serum anti-Müllerian hormone concentrations in female cheetahs, Acinonyx jubatus.

PubMed

Place, Ned J; Crosier, Adrienne E; Comizzoli, Pierre; Nagashima, Jennifer B; Haefele, Holly; Schmidt-Küntzel, Anne; Marker, Laurie L

2017-09-01

Anti-Müllerian hormone (AMH) is widely used in human medicine to non-invasively estimate the size of the ovarian follicle reserve and to predict the ovarian response to gonadotropin stimulation in the context of assisted reproductive technologies (e.g., IVF). These applications of AMH testing have recently expanded to non-human mammals, with production animals, such as cows, goats and sheep being the primary focus of AMH research. However, few investigations have involved exotic species, and in particular carnivores. In this study, we measured AMH concentrations (0.078-3.078ng/mL) in archived serum samples that had been collected from 36 adult female cheetahs across their reproductive lifespan (2-15years of age). Similar to other mammals, AMH concentration in cheetahs declined with age, and its variability among females of the same age was considerable. The rates at which AMH declined over time in individual cheetahs were also highly variable. Five cheetahs had been contracepted with the long-acting GnRH agonist deslorelin for 6-18months prior to sample collection, and their AMH concentrations were relatively low compared to untreated females. In this first study of AMH in an exotic carnivore, the findings demonstrate that the age-associated decline in AMH is highly variable and that deslorelin appears to suppress AMH concentration in serum. Owing to the increased use of assisted reproductive technologies in ex situ populations of threatened and endangered species, such as cheetahs, the present study's findings will need to be taken into consideration if AMH is to be used successfully to optimize breeding management decisions in exotic species. Copyright © 2017 Elsevier Inc. All rights reserved.

Modelling condom use: Does the theory of planned behaviour explain condom use in a low risk, community sample?

PubMed

Thomas, Joanna; Shiels, Chris; Gabbay, Mark B

2014-01-01

To date, most condom research has focused on young or high-risk groups, with little evidence about influences on condom use amongst lower-risk community samples. These groups are not risk free and may still wish to negotiate safer sex; yet the considerations involved could be different from those in higher-risk groups. Our research addresses this gap: We report a cross-sectional questionnaire study enquiring about recent condom use and future use intentions in community settings. Our sample (n = 311) purposively included couples in established relationships, known to be condom users. Items included demographics, sexual history and social-cognitive variables taken from the theory of planned behaviour. The strongest association with condom use/use intentions amongst our respondents was sexual partner's perceived willingness to use them. This applied across both univariate and multivariate analyses. Whilst most social-cognitive variables (attitudes; self-efficacy and peer social norms) were significant in univariate analyses, this was not supported in multivariate regression. Of the social-cognitive variables, only "condom-related attitudes" were retained in the model explaining recent condom use, whilst none of them entered the model explaining future use intentions. Further analysis showed that attitudes concerning pleasure, identity stigma and condom effectiveness were most salient for this cohort. Our results suggest that, in community samples, the decision to use a condom involves different considerations from those highlighted in previous research. Explanatory models for established couples should embrace interpersonal perspectives, emphasising couple-factors rather than individual beliefs. Messages to this cohort could usefully focus on negotiation skills, condom advantages (other than disease prevention) and reducing the stigma associated with use.

Hand preference for writing and associations with selected demographic and behavioral variables in 255,100 subjects: the BBC internet study.

PubMed

Peters, Michael; Reimers, Stian; Manning, John T

2006-11-01

In an Internet study unrelated to handedness, 134,317 female and 120,783 male participants answered a graded question as to which hand they preferred for writing. This allowed determination of hand preference patterns across 7 ethnic groups. Sex differences in left-handedness were found in 4 ethnic groups, favoring males, while no significant sex differences were found in three of the groups. Prevalence of left-handedness in the largest of the ethnic groups (self-labelled as "White") was comparable to contemporary hand preference data for this group [Gilbert, A. N., & Wysocki, C. J. (1992). Hand preference and age in the United states. Neuropsychologia, 30, 601-608] but the prevalence of left-handedness in individuals >70 years of age was considerably higher in the present study. Individuals who indicated "either" hand for writing preference had significantly lower spatial performance (mental rotation task) and significantly higher prevalence of hyperactivity, dyslexia, asthma than individuals who had clear left or right hand preferences, in support of Crow et al. [Crow, T., Crow, L., Done, D., & Leask, S. (1998). Relative hand skill predicts academic ability: global deficits at the point of hemispheric indecision. Neuropsychologia, 36, 1275-1282]. Similarly, an association of writing hand preference and non-heterosexual orientation was clearest for individuals with "either" writing hand responses. We conclude that contradictions in the literature as to whether or not these variables are linked to handedness stem largely from different definitions of hand preference. Due to a lack of statistical power in most studies in the literature, the "either" hand writing preference group that yielded the most salient results in this study is not normally available for analysis.

Initiation and continuation of smoking in iran: a qualitative content analysis.

PubMed

Ebrahimi, Hossein; Sahebihagh, Mohammad Hasan; Ghofranipour, Fazlollah; Sadegh Tabrizi, Jafar

2014-10-01

Smoking is the cause for many preventable deaths worldwide. The rate of smoking has not increased in Iran in the past two decades, but its increase among adolescents and young adults is a concern. This study investigates the risk factors of initiation and continuation of smoking in Iran using a qualitative approach. This is a qualitative content analysis study conducted on 12 smokers and 6 non-smokers in 4 selected cities in Iran. Data were collected with deep and semi-structured interviews, verbatim transcription and simultaneously coding. Then, they were analyzed through content analysis. Three themes and 16 subcategories emerged. The themes were personal inefficacy with 6 subgroups included inadequate information, low age, curiosity, consideration of smoking not as a major problem, wrong beliefs, and making reasons. Family inefficacy with 4 subgroups included poor authority, lack of reaction, existence of stressors, and history of smoking. Vulnerable social environment with 6 subgroups included poverty, social stressors, magnification of smoking, network of cigarette smoking, smoking as a norm and convenience of access. Recognition of smoking among children, modification of wrong beliefs about smoking, empowerment of the individuals against smoking from the very childhood, consideration of familial stress and crisis, and ultimately, paying attention to the role of social variables will play a major role in prevention of smoking and encouraging individuals to quit smoking.

High sequence variability among hemocyte-specific Kazal-type proteinase inhibitors in decapod crustaceans.

PubMed

Cerenius, Lage; Liu, Haipeng; Zhang, Yanjiao; Rimphanitchayakit, Vichien; Tassanakajon, Anchalee; Gunnar Andersson, M; Söderhäll, Kenneth; Söderhäll, Irene

2010-01-01

Crustacean hemocytes were found to produce a large number of transcripts coding for Kazal-type proteinase inhibitors (KPIs). A detailed study performed with the crayfish Pacifastacus leniusculus and the shrimp Penaeus monodon revealed the presence of at least 26 and 20 different Kazal domains from the hemocyte KPIs, respectively. Comparisons with KPIs from other taxa indicate that the sequences of these domains evolve rapidly. A few conserved positions, e.g. six invariant cysteines were present in all domain sequences whereas the position of P1 amino acid, a determinant for substrate specificity, varied highly. A study with a single crayfish animal suggested that even at the individual level considerable sequence variability among hemocyte KPIs produced exist. Expression analysis of four crayfish KPI transcripts in hematopoietic tissue cells and different hemocyte types suggest that some of these KPIs are likely to be involved in hematopoiesis or hemocyte release as they were produced in particular hemocyte types or maturation stages only.

Defining Autism: Variability in State Education Agency Definitions of and Evaluations for Autism Spectrum Disorders

PubMed Central

Pennington, Malinda L.; Cullinan, Douglas; Southern, Louise B.

2014-01-01

In light of the steady rise in the prevalence of students with autism, this study examined the definition of autism published by state education agencies (SEAs), as well as SEA-indicated evaluation procedures for determining student qualification for autism. We compared components of each SEA definition to aspects of autism from two authoritative sources: Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) and Individuals with Disabilities Education Improvement Act (IDEA-2004). We also compared SEA-indicated evaluation procedures across SEAs to evaluation procedures noted in IDEA-2004. Results indicated that many more SEA definitions incorporate IDEA-2004 features than DSM-IV-TR features. However, despite similar foundations, SEA definitions of autism displayed considerable variability. Evaluation procedures were found to vary even more across SEAs. Moreover, within any particular SEA there often was little concordance between the definition (what autism is) and evaluation procedures (how autism is recognized). Recommendations for state and federal policy changes are discussed. PMID:24987527

Morphology, morphometry and probability mapping of the pars opercularis of the inferior frontal gyrus: an in vivo MRI analysis.

PubMed

Tomaiuolo, F; MacDonald, J D; Caramanos, Z; Posner, G; Chiavaras, M; Evans, A C; Petrides, M

1999-09-01

The pars opercularis occupies the posterior part of the inferior frontal gyrus. Electrical stimulation or damage of this region interferes with language production. The present study investigated the morphology and morphometry of the pars opercularis in 108 normal adult human cerebral hemispheres by means of magnetic resonance imaging. The brain images were transformed into a standardized proportional steoreotaxic space (i.e. that of Talairach and Tournoux) in order to minimize interindividual brain size variability. There was considerable variability in the shape and location of the pars opercularis across brains and between cerebral hemispheres. There was no significant difference or correlation between left and right hemisphere grey matter volumes. There was also no significant difference between sex and side of asymmetry of the pars opercularis. A probability map of the pars opercularis was constructed by averaging its location and extent in each individual normalized brain into Talairach space to aid in localization of activity changes in functional neuroimaging studies.

Narrowing the gap: effects of intervention on developmental trajectories in autism.

PubMed

Klintwall, Lars; Eldevik, Sigmund; Eikeseth, Svein

2015-01-01

Although still a matter of some debate, there is a growing body of research supporting Early and Intensive Behavioral Intervention as the intervention of choice for children with autism. Learning rate is an alternative to change in standard scores as an outcome measure in studies of early intervention. Learning rates can be displayed graphically as developmental trajectories, which are easy to understand and avoid some of the counter-intuitive properties of changes in standard scores. The data used in this analysis were from 453 children with autism, previously described by Eldevik et al. Children receiving Early and Intensive Behavioral Intervention exhibited significantly steeper developmental trajectories than children in the control group, in both intelligence and adaptive behaviors. However, there was a considerable variability in individual learning rates within the group receiving Early and Intensive Behavioral Intervention. This variability could partly be explained by the intensity of the treatment, partly by children's intake intelligence quotient age-equivalents. Age at intake did not co-vary with learning rate. © The Author(s) 2013.

The Bilinear Product Model of Hysteresis Phenomena

NASA Astrophysics Data System (ADS)

Kádár, György

1989-01-01

In ferromagnetic materials non-reversible magnetization processes are represented by rather complex hysteresis curves. The phenomenological description of such curves needs the use of multi-valued, yet unambiguous, deterministic functions. The history dependent calculation of consecutive Everett-integrals of the two-variable Preisach-function can account for the main features of hysteresis curves in uniaxial magnetic materials. The traditional Preisach model has recently been modified on the basis of population dynamics considerations, removing the non-real congruency property of the model. The Preisach-function was proposed to be a product of two factors of distinct physical significance: a magnetization dependent function taking into account the overall magnetization state of the body and a bilinear form of a single variable, magnetic field dependent, switching probability function. The most important statement of the bilinear product model is, that the switching process of individual particles is to be separated from the book-keeping procedure of their states. This empirical model of hysteresis can easily be extended to other irreversible physical processes, such as first order phase transitions.

[Variables involved in the individual and collective practice of healthy habits].

PubMed

García-Ubaque, Juan C; García-Ubaque, César A; Vaca-Bohórquez, Martha L

2014-01-01

To conduct a descriptive review of the concepts related to the practice of healthy habits by identifying the main variables associated with their managment in terms of health promotion actions. In consultation with groups working in health promotion in the city of performed by consulting databases and documentary sources. The strategy and criteria for the selection of documents was previously defined. Finally, we proceeded to organizing and structuring the information. It was established that, to promote healthy habits, four groups of behavior are involved: a) consumption, b) phyisical activity and hygiene, c) safety, and d) social participation. All of these are reviewed in order to point out the main concepts contained in each. The promotion of healthy habits must involve not only the transmission of behaviors associated with them. It must also involve understanding and adapting these habits to the environments of life in which people operate, with consideration for the different roles that they perform and the psychological and cultural demands that each space implies.

A semi-empirical analysis of strong-motion peaks in terms of seismic source, propagation path, and local site conditions

NASA Astrophysics Data System (ADS)

Kamiyama, M.; Orourke, M. J.; Flores-Berrones, R.

1992-09-01

A new type of semi-empirical expression for scaling strong-motion peaks in terms of seismic source, propagation path, and local site conditions is derived. Peak acceleration, peak velocity, and peak displacement are analyzed in a similar fashion because they are interrelated. However, emphasis is placed on the peak velocity which is a key ground motion parameter for lifeline earthquake engineering studies. With the help of seismic source theories, the semi-empirical model is derived using strong motions obtained in Japan. In the derivation, statistical considerations are used in the selection of the model itself and the model parameters. Earthquake magnitude M and hypocentral distance r are selected as independent variables and the dummy variables are introduced to identify the amplification factor due to individual local site conditions. The resulting semi-empirical expressions for the peak acceleration, velocity, and displacement are then compared with strong-motion data observed during three earthquakes in the U.S. and Mexico.

Network Mendelian randomization: using genetic variants as instrumental variables to investigate mediation in causal pathways

PubMed Central

Burgess, Stephen; Daniel, Rhian M; Butterworth, Adam S; Thompson, Simon G

2015-01-01

Background: Mendelian randomization uses genetic variants, assumed to be instrumental variables for a particular exposure, to estimate the causal effect of that exposure on an outcome. If the instrumental variable criteria are satisfied, the resulting estimator is consistent even in the presence of unmeasured confounding and reverse causation. Methods: We extend the Mendelian randomization paradigm to investigate more complex networks of relationships between variables, in particular where some of the effect of an exposure on the outcome may operate through an intermediate variable (a mediator). If instrumental variables for the exposure and mediator are available, direct and indirect effects of the exposure on the outcome can be estimated, for example using either a regression-based method or structural equation models. The direction of effect between the exposure and a possible mediator can also be assessed. Methods are illustrated in an applied example considering causal relationships between body mass index, C-reactive protein and uric acid. Results: These estimators are consistent in the presence of unmeasured confounding if, in addition to the instrumental variable assumptions, the effects of both the exposure on the mediator and the mediator on the outcome are homogeneous across individuals and linear without interactions. Nevertheless, a simulation study demonstrates that even considerable heterogeneity in these effects does not lead to bias in the estimates. Conclusions: These methods can be used to estimate direct and indirect causal effects in a mediation setting, and have potential for the investigation of more complex networks between multiple interrelated exposures and disease outcomes. PMID:25150977

Subjective Probabilities in Household Surveys

PubMed Central

Hurd, Michael D.

2011-01-01

Subjective probabilities are now collected on a number of large household surveys with the objective of providing data to better understand inter-temporal decision making. Comparison of subjective probabilities with actual outcomes shows that the probabilities have considerable predictive power in situations where individuals have considerable private information such as survival and retirement. In contrast the subjective probability of a stock market gain varies greatly across individuals even though no one has private information and the outcome is the same for everyone. An explanation is that there is considerable variation in accessing and processing information. Further, the subjective probability of a stock market gain is considerably lower than historical averages, providing an explanation for the relatively low frequency of stock holding. An important research objective will be to understand how individuals form their subjective probabilities. PMID:21643535

Fine-Scale Spatial Variability of Precipitation, Soil, and Plant Water Isotopes

NASA Astrophysics Data System (ADS)

Goldsmith, G. R.; Braun, S.; Romero, C.; Engbersen, N.; Gessler, A.; Siegwolf, R. T.; Schmid, L.

2015-12-01

Introduction: The measurement of stable isotope ratios of water has become fundamental in advancing our understanding of environmental patterns and processes, particularly with respect to understanding the movement of water within the soil-plant-atmosphere continuum. While considerable research has explored the temporal variation in stable isotope ratios of water in the environment, our understanding of the spatial variability of these isotopes remains poorly understood. Methods: We collected spatially explicit samples of throughfall and soil water (n=150 locations) from a 1 ha plot delineated in a mixed deciduous forest in the northern Alps of Switzerland. We complemented this with fully sunlit branch and leaf samples (n = 60 individuals) collected from Picea abies and Fagus sylvatica between 14:00 and 16:00 on the same day by means of a helicopter. Soil and plant waters were extracted using cryogenic vacuum distillation and all samples were analyzed for δ18O using an isotope ratio mass spectrometer. Results: The mean δ18O of throughfall (-3.3 ± 0.8‰) indicated some evaporative enrichment associated with passage through the canopy, but this did not significantly differ from the precipitation collected in nearby open sites (-4.05‰). However, soil was depleted (-7.0 ± 1.8‰) compared to throughfall and there was no significant relationship between the two, suggesting that the sampling for precipitation inputs did not capture all the sources (e.g. stream water, which was -11.5‰) contributing to soil water δ18O ratios. Evaporative enrichment of δ18O was higher in leaves of Fagus (14.8 ± 1.8‰) than in leaves of Picea (11.8 ± 1.7‰). Sampling within crowns of each species (n = 5 branches each from 5 individuals) indicated that variability in a single individual is similar to that among individuals. Discussion: Stable isotopes of water are frequently engaged for studies of ecohydrology, plant ecophysiology, and paleoclimatology. Our results help constrain the variability within different water sources across space (e.g. when vizualized as isoscapes), as well as the extent of fractionation among those sources as water moves through the critical zone. In doing so, we also provide insight into how environment shapes this fine-scale variation in order to inform future applications of water isotopes.

Social and cultural sustainability: criteria, indicators, verifier variables for measurement and maps for visualization to support planning.

PubMed

Axelsson, Robert; Angelstam, Per; Degerman, Erik; Teitelbaum, Sara; Andersson, Kjell; Elbakidze, Marine; Drotz, Marcus K

2013-03-01

Policies on economic use of natural resources require considerations to social and cultural values. In order to make those concrete in a planning context, this paper aims to interpret social and cultural criteria, identify indicators, match these with verifier variables and visualize them on maps. Indicators were selected from a review of scholarly work and natural resource policies, and then matched with verifier variables available for Sweden's 290 municipalities. Maps of the spatial distribution of four social and four cultural verifier variables were then produced. Consideration of social and cultural values in the studied natural resource use sectors was limited. The spatial distribution of the verifier variables exhibited a general divide between northwest and south Sweden, and regional rural and urban areas. We conclude that it is possible to identify indicators and match them with verifier variables to support inclusion of social and cultural values in planning.

That's my teacher! Children's ability to recognize personally familiar and unfamiliar faces improves with age.

PubMed

Laurence, Sarah; Mondloch, Catherine J

2016-03-01

Most previous research on the development of face recognition has focused on recognition of highly controlled images. One of the biggest challenges of face recognition is to identify an individual across images that capture natural variability in appearance. We created a child-friendly version of Jenkins, White, Van Montford, and Burton's sorting task (Cognition, 2011, Vol. 121, pp. 313-323) to investigate children's recognition of personally familiar and unfamiliar faces. Children between 4 and 12years of age were presented with a familiar/unfamiliar teacher's house and a pile of face photographs (nine pictures each of the teacher and another identity). Each child was asked to put all the pictures of the teacher inside the house while keeping the other identity out. Children over 6years of age showed adult-like familiar face recognition. Unfamiliar face recognition improved across the entire age range, with considerable variability in children's performance. These findings suggest that children's ability to tolerate within-person variability improves with age and support a face-space framework in which faces are represented as regions, the size of which increases with age. Copyright © 2015 Elsevier Inc. All rights reserved.

Sexting prevalence and correlates: a systematic literature review.

PubMed

Klettke, Bianca; Hallford, David J; Mellor, David J

2014-02-01

Despite considerable controversy and speculation regarding sexting behaviour and its associated risks, to date there has been no integration and analysis of empirical literature on this topic. To collect and synthesise findings of the prevalence of sexting, its correlates, and the context in which it occurs, a systematic search of databases was conducted. Thirty-one studies, reporting on sexting prevalence and a diverse range of related variables, met inclusion criteria. The estimated mean prevalence weighted by sample size was calculated, with trends indicating sexting is more prevalent amongst adults than adolescents, older age is predictive of sexting for adolescents but not adults, and more individuals report receiving sexts than sending them. The correlates of sexting behaviour were grouped in terms of demographic variables, sexual and sexual risk behaviours, attitudes towards sexting, perceived outcomes of sexting, motivations for sexting, mental health and well-being variables, and attachment dimensions. Findings are discussed in terms of the trends indicated by the data, which provided substantiation that sexting behaviour is associated with numerous behavioural, psychological, and social factors. Limitations of the current research literature and future directions are also presented. Copyright © 2013 Elsevier Ltd. All rights reserved.

Visual bottle inspection performance in highly paced belt-conveyor systems.

PubMed

Saito, M; Tanaka, T

1977-12-01

The relation between visual work performance and a few variables with immediate effects, i.e, lighting, work speed, work spell, etc. was studied. At the same time, some physiological and behavioral variations obtained in the study were also discussed. Through experiments and surveys, the optimum conditions were found for each variable. Work performance, however, is affected in such a subtle, interactive and dynamic manner that the working conditions are to be adjusted by taking into account not only these variables having immediate effects but also those indirectly relating ones meeting real needs in the practical working fields. Improvement of some physical working conditions, such as lighting, produces only a transitory increase of performance which is very unstable unless other determinants of performance are simultaneously managed in a proper manner. The same applied to arrangement of the optimum work speed and work spell for highly paced visual inspection, variations in rejection rate and in physiological functions interacting with individual and other determinants. In order to maximize understanding of the integrated and synthesized manner of determinants, it is emphasized that work performance must be pursued in a considerably comprehensive framework from a long-term perspective.

Large-scale human skin lipidomics by quantitative, high-throughput shotgun mass spectrometry.

PubMed

Sadowski, Tomasz; Klose, Christian; Gerl, Mathias J; Wójcik-Maciejewicz, Anna; Herzog, Ronny; Simons, Kai; Reich, Adam; Surma, Michal A

2017-03-07

The lipid composition of human skin is essential for its function; however the simultaneous quantification of a wide range of stratum corneum (SC) and sebaceous lipids is not trivial. We developed and validated a quantitative high-throughput shotgun mass spectrometry-based platform for lipid analysis of tape-stripped SC skin samples. It features coverage of 16 lipid classes; total quantification to the level of individual lipid molecules; high reproducibility and high-throughput capabilities. With this method we conducted a large lipidomic survey of 268 human SC samples, where we investigated the relationship between sampling depth and lipid composition, lipidome variability in samples from 14 different sampling sites on the human body and finally, we assessed the impact of age and sex on lipidome variability in 104 healthy subjects. We found sebaceous lipids to constitute an abundant component of the SC lipidome as they diffuse into the topmost SC layers forming a gradient. Lipidomic variability with respect to sampling depth, site and subject is considerable, and mainly accredited to sebaceous lipids, while stratum corneum lipids vary less. This stresses the importance of sampling design and the role of sebaceous lipids in skin studies.

A Systems Approach to Explaining Teachers' Leadership Behavior.

ERIC Educational Resources Information Center

Peterson, Mark F.; Cooke, Robert A.

This paper focuses on identifying the way that individual and organizational variables affect the classroom leadership behavior of teachers. Measured are the effects of one individual-level variable and six organizational variables--three at the organization system level and three at the classroom subsystem level. The individual-level variable is…

Within- and between-laboratory precision in the measurement of body volume using air displacement plethysmography and its effect on body composition assessment.

PubMed

Collins, A L; Saunders, S; McCarthy, H D; Williams, J E; Fuller, N J

2004-01-01

To determine and compare the extent of within- and between-laboratory precision in body volume (BV) measurements using air displacement plethysmography (ADP), the BOD POD body composition system, and to interpret any such variability in terms of body composition estimates. Repeated test procedures of BV assessment using the BOD POD ADP were reproduced at two laboratories for the estimation of precision, both within and between laboratories. In total, 30 healthy adult volunteers, 14 men (age, 19-48 y; body mass index (BMI), 19.7-30.3 kg/m2) and 16 women (age, 19-40 y; BMI, 16.3-35.7 kg/m2), were each subjected to two test procedures at both laboratories. Two additional volunteers were independently subjected to 10 repeated test procedures at both laboratories. Repeated measurements of BV, uncorrected for the effects of isothermal air in the lungs and the surface area artifact, were obtained using the BOD POD ADP, with the identical protocol being faithfully applied at both laboratories. Uncorrected BV measurements were adjusted to give estimates of actual BV that were used to calculate body density (body weight (BWt)/actual BV) from which estimates of body composition were derived. The differences between repeated BV measurements or body composition estimates were used to assess within-laboratory precision (repeatability), as standard deviation (SD) and coefficient of variation; the differences between measurements reproduced at each laboratory were used to determine between-laboratory precision (reproducibility), as bias and 95% limits of agreement (from SD of the differences between laboratories). The extent of within-laboratory methodological precision for BV (uncorrected and actual) was variable according to subject, sample group and laboratory conditions (range of SD, 0.04-0.13 l), and was mostly due to within-individual biological variability (typically 78-99%) rather than to technical imprecision. There was a significant (P<0.05) bias between laboratories for the 10 repeats on the two independent subjects (up to 0.29 l). Although no significant bias (P=0.077) was evident for the sample group of 30 volunteers (-0.05 l), the 95% limits of agreement were considerable (-0.68 to 0.58 l). The effects of this variability in BV on body composition were relatively greater: for example, within-laboratory precision (SD) for body fat as % BWt was between 0.56 and 1.34% depending on the subject and laboratory; the bias (-0.59%) was not significant between laboratories, but there were large 95% limits of agreement (-3.67 to 2.50%). Within-laboratory precision for each BOD POD instrument was reasonably good, but was variable according to the prevailing conditions. Although the bias between the two instruments was not significant for the BV measurements, implying that they can be used interchangeably for groups of similar subjects, the relatively large 95% limits of agreement indicate that greater consideration may be needed for assessing individuals with different ADP instruments. Therefore, use of a single ADP instrument is apparently preferable when assessing individuals on a longitudinal basis.

Variability of dissolved organic carbon in precipitation during storms at the Shale Hills Critical Zone Observatory

USGS Publications Warehouse

Iavorivska , Lidiia; Boyer, Elizabeth W.; Grimm, Jeffrey W.; Miller, Matthew P.; DeWalle, David R.; Davis, Kenneth J.; Kaye, Margot W.

2017-01-01

Organic compounds are removed from the atmosphere and deposited to the earth's surface via precipitation. In this study, we quantified variations of dissolved organic carbon (DOC) in precipitation during storm events at the Shale Hills Critical Zone Observatory, a forested watershed in central Pennsylvania (USA). Precipitation samples were collected consecutively throughout the storm during 13 events, which spanned a range of seasons and synoptic meteorological conditions, including a hurricane. Further, we explored factors that affect the temporal variability by considering relationships of DOC in precipitation with atmospheric and storm characteristics. Concentrations and chemical composition of DOC changed considerably during storms, with the magnitude of change within individual events being comparable or higher than the range of variation in average event composition among events. While some previous studies observed that concentrations of other elements in precipitation typically decrease over the course of individual storm events, results of this study show that DOC concentrations in precipitation are highly variable. During most storm events concentrations decreased over time, possibly as a result of washing out of the below-cloud atmosphere. However, increasing concentrations that were observed in the later stages of some storm events highlight that DOC removal with precipitation is not merely a dilution response. Increases in DOC during events could result from advection of air masses, local emissions during breaks in precipitation, or chemical transformations in the atmosphere that enhance solubility of organic carbon compounds. This work advances understanding of processes occurring during storms that are relevant to studies of atmospheric chemistry, carbon cycling, and ecosystem responses.

Productivity losses associated with diabetes in the US.

PubMed

Ng, Y C; Jacobs, P; Johnson, J A

2001-02-01

The objective of this study was to estimate the cost of productivity losses in the U.S. attributable to diabetes, with regard to specific demographic and disease-related characteristics in the U.S.. We used the 1989 National Health Interview Survey, a random survey of individuals in the U.S. that included a diabetes supplement. Data on individuals were obtained for labor force participation, hours of work, demographic and occupational characteristics, self-reported health status, and several variables that indicated the presence, duration, and severity (complications) of diabetes. Using multivariate regression analyses, we estimated the association of independent variables (e.g., demographics, health, and diabetes status) with labor force participation, hours of work lost, and the economic value of lost work attributable to diabetes and its complications and duration. In general, the presence of diabetes and complications were found to be related to workforce participation variables. The magnitude of the lost-productivity costs depended on personal characteristics and on the presence and status of diabetes. In general, the loss of yearly earnings amounted to about a one-third reduction in earnings and ranged from $3,700 to $8,700 per annum. Diabetes has a considerable net effect on earnings, and the complications and duration of diabetes have compound effects. Our findings have implications for the cost-effectiveness of diabetes control; the presence of complicating factors is the single most important predictive factor in lost productivity costs attributable to diabetes, and thus the avoidance or retardation of complications will have an impact on indirect health-related costs.

High resolution spatio-temporal mapping of NO2 pollution for estimating personal exposures of the Dutch population

NASA Astrophysics Data System (ADS)

Soenario, Ivan; Helbich, Marco; Schmitz, Oliver; Strak, Maciek; Hoek, Gerard; Karssenberg, Derek

2017-04-01

Air pollution has been associated with adverse health effects (e.g., cardiovascular and respiration diseases) in the urban environments. Therefore, the assessment of people's exposure to air pollution is central in epidemiological studies. The estimation of exposures on an individual level can be done by combining location information across space and over time with spatio-temporal data on air pollution concentrations. When detailed information on peoples' space-time paths (e.g. commuting patterns calculated by means of spatial routing algorithms or tracked through GPS) and peoples' major activity locations (e.g. home location, work location) are available, it is possible to calculate more precise personal exposure levels depending on peoples' individual space-time mobility patterns. This requires air pollution values not only at a high level of spatial accuracy and high temporal granularity but such data also needs to be available on a nation-wide scale. As current data is seriously limited in this respect, we introduce a novel data set of NO2 levels across the Netherlands. The provided NO2 concentrations are accessible on hourly timestamps on a 5 meter grid cell resolution for weekdays and weekends, and each month of the year. We modeled a single Land Use Regression model using a five year average of NO2 data from the Dutch NO2 measurement network consisting of N=46 sampling locations distributed over the country. Predictor variables for this model were selected in a data-driven manner using an Elastic Net and Best Subset Selection procedure from 70 candidate predictors including traffic, industry, infrastructure and population-based variables. Subsequently, to model NO2 for each time scale (hour, week, month), the LUR coefficients were fitted using the NO2 data, aggregated per time scale. Model validation was grounded on independent data collected in an ad hoc measurement campaign. Our results show a considerable difference in urban concentrations between weekdays and weekend-days. We observe a diurnal variation in concentrations particularly during weekdays related to traffic intensity and considerable differences in concentrations between seasons. Considerable spatial variation occurs both within cities and urban areas where concentrations on roads are high and decrease rapidly with distance to roads. Both on-road and far-from-road concentrations are consistently higher in urban areas than in rural areas.

31 CFR Appendix C to Part 356 - Investment Considerations

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Investment Considerations C Appendix C..., App. C Appendix C to Part 356—Investment Considerations I. Inflation-Protected Securities A. Principal and Interest Variability An investment in securities with principal or interest determined by...

Strontium isotope evidence for a highly mobile population on the Pamir Plateau 2500 years ago

NASA Astrophysics Data System (ADS)

Wang, Xueye; Tang, Zihua; Wu, Jing; Wu, Xinhua; Wu, Yiqun; Zhou, Xinying

2016-10-01

Archeological researches have proposed arguments for human mobility and long-distance trading over the Eurasia before the Silk Roads. Here we utilize biologically available strontium isotope analysis to assess the extent of pre-Silk Road population movements and cultural communications across the Asian interior. From an early Iron Age cemetery (ca. 2500 yr B.P.) on the eastern Pamir Plateau, mean 87Sr/86Sr ratios from 34 individuals display considerable isotopic variability, and 10 individuals are distinguished as migrants based on the local strontium isotope range of 0.710296-0.710572 defined by 12 ovicaprine bones. Comparison of the proportion (10/34) with the regional census data completed in 1909 A.D. (3% non-locals) suggests a highly migratory behavior on the plateau 2500 years ago. Furthermore, exotic mortuary objects, such as silk fabrics from eastern China and angular harp originated from the Near East, clearly demonstrate an interaction between different cultures on the plateau before the establishment of the Silk Road.

Cross-cultural dataset for the evolution of religion and morality project.

PubMed

Purzycki, Benjamin Grant; Apicella, Coren; Atkinson, Quentin D; Cohen, Emma; McNamara, Rita Anne; Willard, Aiyana K; Xygalatas, Dimitris; Norenzayan, Ara; Henrich, Joseph

2016-11-08

A considerable body of research cross-culturally examines the evolution of religious traditions, beliefs and behaviors. The bulk of this research, however, draws from coded qualitative ethnographies rather than from standardized methods specifically designed to measure religious beliefs and behaviors. Psychological data sets that examine religious thought and behavior in controlled conditions tend to be disproportionately sampled from student populations. Some cross-national databases employ standardized methods at the individual level, but are primarily focused on fully market integrated, state-level societies. The Evolution of Religion and Morality Project sought to generate a data set that systematically probed individual level measures sampling across a wider range of human populations. The set includes data from behavioral economic experiments and detailed surveys of demographics, religious beliefs and practices, material security, and intergroup perceptions. This paper describes the methods and variables, briefly introduces the sites and sampling techniques, notes inconsistencies across sites, and provides some basic reporting for the data set.

Genetic and environmental contributions to children's prosocial behavior: brief review and new evidence from a reanalysis of experimental twin data.

PubMed

Knafo-Noam, Ariel; Vertsberger, Dana; Israel, Salomon

2018-04-01

Children's prosocial behaviors show considerable variability. Here we discuss the genetic and environmental contributions to individual differences in children's prosocial behavior. Twin research systematically shows, at least from the age of 3 years, a genetic contribution to individual differences in prosocial behavior, both questionnaire-based and observed. This finding is demonstrated across a wide variety of cultures. We discuss the possibility that different prosocial behaviors have different genetic etiologies. A re-analysis of past twin data shows that sharing and comforting are affected by overlapping genetic factors at age 3.5 years. In contrast, the association between helping and comforting is attributed to environmental factors. The few molecular genetic studies of children's prosocial behavior are reviewed, and we point out genome-wide and polygenic methods as a key future direction. Finally, we discuss the interplay of genetic and environmental factors, focusing on both gene×environment interactions and gene-environment correlations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hormonal mechanisms of cooperative behaviour

PubMed Central

Soares, Marta C.; Bshary, Redouan; Fusani, Leonida; Goymann, Wolfgang; Hau, Michaela; Hirschenhauser, Katharina; Oliveira, Rui F.

2010-01-01

Research on the diversity, evolution and stability of cooperative behaviour has generated a considerable body of work. As concepts simplify the real world, theoretical solutions are typically also simple. Real behaviour, in contrast, is often much more diverse. Such diversity, which is increasingly acknowledged to help in stabilizing cooperative outcomes, warrants detailed research about the proximate mechanisms underlying decision-making. Our aim here is to focus on the potential role of neuroendocrine mechanisms on the regulation of the expression of cooperative behaviour in vertebrates. We first provide a brief introduction into the neuroendocrine basis of social behaviour. We then evaluate how hormones may influence known cognitive modules that are involved in decision-making processes that may lead to cooperative behaviour. Based on this evaluation, we will discuss specific examples of how hormones may contribute to the variability of cooperative behaviour at three different levels: (i) within an individual; (ii) between individuals and (iii) between species. We hope that these ideas spur increased research on the behavioural endocrinology of cooperation. PMID:20679116

Caregiver Training in Mindfulness-Based Positive Behavior Supports (MBPBS): Effects on Caregivers and Adults with Intellectual and Developmental Disabilities

PubMed Central

Singh, Nirbhay N.; Lancioni, Giulio E.; Karazsia, Bryan T.; Myers, Rachel E.

2016-01-01

Caregivers often manage the aggressive behavior of individuals with intellectual and developmental disabilities that reside in community group homes. Sometimes this results in adverse outcomes for both the caregivers and the care recipients. We provided a 7-day intensive Mindfulness-Based Positive Behavior Support (MBPBS) training to caregivers from community group homes and assessed the outcomes in terms of caregiver variables, individuals’ behaviors, and an administrative outcome. When compared to pre-MBPBS training, the MBPBS training resulted in the caregivers using significantly less physical restraints, and staff stress and staff turnover were considerably reduced. The frequency of injury to caregivers and peers caused by the individuals was significantly reduced. A benefit-cost analysis showed substantial financial savings due to staff participation in the MBPBS program. This study provides further proof-of-concept for the effectiveness of MBPBS training for caregivers, and strengthens the call for training staff in mindfulness meditation. PMID:26903906

Variability in Foliar Ellagitannins of Hippophaë rhamnoides L. and Identification of a New Ellagitannin, Hippophaenin C.

PubMed

Suvanto, Jussi; Tähtinen, Petri; Valkamaa, Saku; Engström, Marica T; Karonen, Maarit; Salminen, Juha-Pekka

2018-01-24

Berries of common sea-buckthorn (Hippophaë rhamnoides L.) are well-known and used for their bioactive components, and while there is a considerable amount of research on the leaves as well, their ellagitannins (ETs) have not been a prominent focus of research. We identified and quantified ten major hydrophilic polyphenols, all ETs, in H. rhamnoides leaves and compared their abundance between 58 plant individuals. Of these compounds, hippophaenin C was characterized as a new ellagitannin by various spectrometric methods. The total concentrations of ETs ranged from 42.5 mg g -1 dry weight (DW) to 109.1 mg g -1 DW between individual plants. Among the ETs, hippophaenin C, stachyurin, and casuarinin were on average the most abundant compounds. Sexes did not differ significantly, while cultivars showed variation in some ETs. These results suggest that H. rhamnoides leaves could be a potential and rich source of several ETs.

Cross-cultural dataset for the evolution of religion and morality project

PubMed Central

Purzycki, Benjamin Grant; Apicella, Coren; Atkinson, Quentin D.; Cohen, Emma; McNamara, Rita Anne; Willard, Aiyana K.; Xygalatas, Dimitris; Norenzayan, Ara; Henrich, Joseph

2016-01-01

A considerable body of research cross-culturally examines the evolution of religious traditions, beliefs and behaviors. The bulk of this research, however, draws from coded qualitative ethnographies rather than from standardized methods specifically designed to measure religious beliefs and behaviors. Psychological data sets that examine religious thought and behavior in controlled conditions tend to be disproportionately sampled from student populations. Some cross-national databases employ standardized methods at the individual level, but are primarily focused on fully market integrated, state-level societies. The Evolution of Religion and Morality Project sought to generate a data set that systematically probed individual level measures sampling across a wider range of human populations. The set includes data from behavioral economic experiments and detailed surveys of demographics, religious beliefs and practices, material security, and intergroup perceptions. This paper describes the methods and variables, briefly introduces the sites and sampling techniques, notes inconsistencies across sites, and provides some basic reporting for the data set. PMID:27824332

Precision medicine and drug development in Alzheimer's disease: The importance of sexual dimorphism and patient stratification.

PubMed

Hampel, Harald; Vergallo, Andrea; Giorgi, Filippo Sean; Kim, Seung Hyun; Depypere, Herman; Graziani, Manuela; Saidi, Amira; Nisticò, Robert; Lista, Simone

2018-06-12

Neurodegenerative diseases (ND) are among the leading causes of disability and mortality. Considerable sex differences exist in the occurrence of the various manifestations leading to cognitive decline. Alzheimer's disease (AD) exhibits substantial sexual dimorphisms and disproportionately affects women. Women have a higher life expectancy compared to men and, consequently, have more lifespan to develop AD. The emerging precision medicine and pharmacology concepts - taking into account the individual genetic and biological variability relevant for disease risk, prevention, detection, diagnosis, and treatment - are expected to substantially enhance our knowledge and management of AD. Stratifying the affected individuals by sex and gender is an important basic step towards personalization of scientific research, drug development, and care. We hypothesize that sex and gender differences, extending from genetic to psychosocial domains, are highly relevant for the understanding of AD pathophysiology, and for the conceptualization of basic/translational research and for clinical therapy trial design. Copyright © 2018 Elsevier Inc. All rights reserved.

Social distance and stigma toward individuals with schizophrenia: findings in an urban, African-American community sample.

PubMed

Broussard, Beth; Goulding, Sandra M; Talley, Colin L; Compton, Michael T

2012-11-01

Because schizophrenia is arguably among the most stigmatized health conditions, research assessing correlates of stigma is essential. This study examined factors associated with stigma in predominantly Protestant, low-income, urban African Americans in the Southeastern United States. A survey was distributed to 282 patrons of an inner-city food court/farmers' market. Associations were assessed between two measures of stigma--an adapted version of the Social Distance Scale (SDS) and a Semantic Differential Measure (SDM) of attributes such as dangerousness, dirtiness, and worthlessness--and several key variables addressing sociodemographic characteristics and exposure to/familiarity with mental illnesses. Independent predictors of scores on the two measures were identified using linear regression modeling. Higher stigma (as measured by the SDM) was predicted by a family history of psychiatric treatment, whereas lower stigma (as indicated by the SDS) was predicted by personal psychiatric treatment history and higher annual income. The results suggest special considerations when working with disenfranchised populations, especially family members of individuals with mental illnesses, in treatment settings.

The importance of job autonomy, cognitive ability, and job-related skill for predicting role breadth and job performance.

PubMed

Morgeson, Frederick P; Delaney-Klinger, Kelly; Hemingway, Monica A

2005-03-01

Role theory suggests and empirical research has found that there is considerable variation in how broadly individuals define their jobs. We investigated the theoretically meaningful yet infrequently studied relationships between incumbent job autonomy, cognitive ability, job-related skill, role breadth, and job performance. Using multiple data sources and multiple measurement occasions in a field setting, we found that job autonomy, cognitive ability, and job-related skill were positively related to role breadth, accounting for 23% of the variance in role breadth. In addition, role breadth was positively related to job performance and was found to mediate the relationship between job autonomy, cognitive ability, job-related skill, and job performance. These results add to our understanding of the factors that predict role breadth, as well as having implications for how job aspects and individual characteristics are translated into performance outcomes and the treatment of variability in incumbent reports of job tasks.

High levels of wheel running protect against behavioral sensitization to cocaine.

PubMed

Renteria Diaz, Laura; Siontas, Dora; Mendoza, Jose; Arvanitogiannis, Andreas

2013-01-15

Although there is no doubt that the direct action of stimulant drugs on the brain is necessary for sensitization to their behavioral stimulating effects, several experiments indicate that drug action is often not sufficient to produce sensitization. There is considerable evidence that many individual characteristics and experiential variables can modulate the behavioral and neural changes that are seen following repeated exposure to stimulant drugs. In the work presented here, we examined whether chronic wheel running would modulate behavioral sensitization to cocaine, and whether any such influence was contingent on individual differences in wheel running. We found that a 5- or 10-week experience with wheel running protects against behavioral sensitization to cocaine but only in animals with a natural tendency to run the most. Understanding the mechanism underlying the modulating effect of wheel running on behavioral sensitization may have important implications for future studies on the link between drug-induced behavioral and neural adaptations. Copyright © 2012 Elsevier B.V. All rights reserved.

Alcohol-related negative consequences among drinkers around the world.

PubMed

Graham, Kathryn; Bernards, Sharon; Knibbe, Ronald; Kairouz, Sylvia; Kuntsche, Sandra; Wilsnack, Sharon C; Greenfield, Thomas K; Dietze, Paul; Obot, Isidore; Gmel, Gerhard

2011-08-01

This paper examines (i) gender and country differences in negative consequences related to drinking; (ii) relative rates of different consequences; and (iii) country-level predictors of consequences. Multi-level analyses used survey data from the Gender, Alcohol, and Culture: An International Study (GENACIS) collaboration. Measures included 17 negative consequences grouped into (i) high endorsement acute, (ii) personal and (iii) social. Country-level measures included average frequency and quantity of drinking, percentage who were current drinkers, gross domestic product (GDP) and Human Development Index (HDI). Overall, the three groupings of consequences were reported by 44%, 12% and 7% of men and by 31%, 6% and 3% of women, respectively. More men than women endorsed all consequences, but gender differences were greatest for consequences associated with chronic drinking and social consequences related to male roles. The highest prevalence of consequences was in Uganda and lowest in Uruguay. Personal and social consequences were more likely in countries with higher usual quantity, fewer current drinkers and lower scores on GDP and HDI. However, significant interactions with individual-level quantity indicated a stronger relationship between consequences and usual quantity among drinkers in countries with lower quantity, more current drinkers and higher scores on GDP and HDI. Both gender and country need to be taken into consideration when assessing adverse drinking consequences. Individual measures of alcohol consumption and country-level variables are associated with experiencing such consequences. Additionally, country-level variables affect the strength of the relationship between usual quantity consumed by individuals and adverse consequences. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

Genetic characterization of Strongyloides spp. from captive, semi-captive and wild Bornean orangutans (Pongo pygmaeus) in Central and East Kalimantan, Borneo, Indonesia.

PubMed

Labes, E M; Nurcahyo, W; Wijayanti, N; Deplazes, P; Mathis, A

2011-09-01

Orangutans (Pongo spp.), Asia's only great apes, are threatened in their survival due to habitat loss, hunting and infections. Nematodes of the genus Strongyloides may represent a severe cause of death in wild and captive individuals. In order to better understand which Strongyloides species/subspecies infect orangutans under different conditions, larvae were isolated from fecal material collected in Indonesia from 9 captive, 2 semi-captive and 9 wild individuals, 18 captive groups of Bornean orangutans and from 1 human working with wild orangutans. Genotyping was done at the genomic rDNA locus (part of the 18S rRNA gene and internal transcribed spacer 1, ITS1) by sequencing amplicons. Thirty isolates, including the one from the human, could be identified as S. fuelleborni fuelleborni with 18S rRNA gene identities of 98·5-100%, with a corresponding published sequence. The ITS1 sequences could be determined for 17 of these isolates revealing a huge variability and 2 main clusters without obvious pattern with regard to attributes of the hosts. The ITS1 amplicons of 2 isolates were cloned and sequenced, revealing considerable variability indicative of mixed infections. One isolate from a captive individual was identified as S. stercoralis (18S rRNA) and showed 99% identity (ITS1) with S. stercoralis sequences from geographically distinct locations and host species. The findings are significant with regard to the zoonotic nature of these parasites and might contribute to the conservation of remaining orangutan populations.

Phenological Variation Within and Among Populations of Plathymenia reticulata in Brazilian Cerrado, the Atlantic Forest and Transitional Sites

PubMed Central

GOULART, MAÍRA FIGUEIREDO; LEMOS FILHO, JOSÉ PIRES; LOVATO, MARIA BERNADETE

2005-01-01

• Background and Aims Plathymenia reticulata (Leguminosae) is a Brazilian tree that occurs in two biomes: Cerrado, a woody savanna vegetation, and the Atlantic Forest, a tropical forest. In this study, phenological patterns and their variability within and among populations located in these biomes and in transitional zones between them were assessed. • Methods During a 15-month period, individuals from two populations in Cerrado, two in the Atlantic Forest, and six in transitional zones (three in a cerrado-like environment and three in forest fragments) were evaluated in Minas Gerais State, Brazil. The individuals were evaluated monthly according to the proportion of the canopy in each vegetative phenophase (leaf fall, leaf flush and mature leaves) and each reproductive phenophase (floral buds, flowers, immature fruits and mature fruit/seed dispersal). In order to assess the phenological variability within and among populations, habitats and biomes, the Shannon–Wiener diversity index, the Morisita–Horn similarity index and genetic population approach of partitioning diversity were used. • Key Results Populations of P. reticulata, in general, showed similar phenology; the main differences were related to leaf fall, a process that starts months earlier in the Cerrado than in transitional sites, and even later in forest areas. Considerable synchrony was observed for reproductive phenology among populations and between biomes. Most phenological diversity was due to differences among individuals within populations. • Conclusion In spite of environmental differences, P. reticulata from the Atlantic Forest and Cerrado showed similar phenological behavior with only about 10 % of the total diversity being attributed to differences between biomes. PMID:15972799

Lung volume is a determinant of aerosol bolus dispersion.

PubMed

Schulz, Holger; Eder, Gunter; Heyder, Joachim

2003-01-01

The technique of inhaling a small volume element labeled with particles ("aerosol bolus") can be used to assess convective gas mixing in the lung. While a bolus undergoes mixing in the lung, particles are dispersed in an increasing volume of the respired air. However, determining factors of bolus dispersion are not yet completely understood. The present study tested the hypothesis that bolus dispersion is related, among others, to the total volume in which the bolus is allowed to mix--i.e., to the individual lung size. Bolus dispersion was measured in 32 anesthetized, mechanically ventilated dogs with total lung capacities (TLCs) of 1.1-2.5 L. Six-milliliter aerosol boluses were introduced at various preselected time-points during inspiration to probe different volumetric lung depths. Dispersion (SD) was determined by moment analysis of particle concentrations in the expired air. We found linear correlations between SD at a given lung depth and the individual end-inspiratory lung volume (V(L)). The relationship was tightest for boluses inhaled deepest into the lungs: SD(40) = 0.068 V(L) - 1.77, r(2) = 0.59. Normalizing SD to V(L) abolished this dependency and resulted in a considerable reduction of inter-individual variability as compared to the uncorrected measurements. These data indicate that lung size influences measurements of bolus dispersion. It therefore appears reasonable to apply a normalization procedure before interpreting the data. Apart from a reduction in measurement variability, this should help to separate the effects on bolus dispersion of altered lung volumes and altered mixing processes in diseased lungs.

Kinematic measures for assessing gait stability in elderly individuals: a systematic review

PubMed Central

Hamacher, D.; Singh, N.B.; Van Dieën, J.H.; Heller, M.O.; Taylor, W.R.

2011-01-01

Falls not only present a considerable health threat, but the resulting treatment and loss of working days also place a heavy economic burden on society. Gait instability is a major fall risk factor, particularly in geriatric patients, and walking is one of the most frequent dynamic activities of daily living. To allow preventive strategies to become effective, it is therefore imperative to identify individuals with an unstable gait. Assessment of dynamic stability and gait variability via biomechanical measures of foot kinematics provides a viable option for quantitative evaluation of gait stability, but the ability of these methods to predict falls has generally not been assessed. Although various methods for assessing gait stability exist, their sensitivity and applicability in a clinical setting, as well as their cost-effectiveness, need verification. The objective of this systematic review was therefore to evaluate the sensitivity of biomechanical measures that quantify gait stability among elderly individuals and to evaluate the cost of measurement instrumentation required for application in a clinical setting. To assess gait stability, a comparative effect size (Cohen's d) analysis of variability and dynamic stability of foot trajectories during level walking was performed on 29 of an initial yield of 9889 articles from four electronic databases. The results of this survey demonstrate that linear variability of temporal measures of swing and stance was most capable of distinguishing between fallers and non-fallers, whereas step width and stride velocity prove more capable of discriminating between old versus young (OY) adults. In addition, while orbital stability measures (Floquet multipliers) applied to gait have been shown to distinguish between both elderly fallers and non-fallers as well as between young and old adults, local stability measures (λs) have been able to distinguish between young and old adults. Both linear and nonlinear measures of foot time series during gait seem to hold predictive ability in distinguishing healthy from fall-prone elderly adults. In conclusion, biomechanical measurements offer promise for identifying individuals at risk of falling and can be obtained with relatively low-cost tools. Incorporation of the most promising measures in combined retrospective and prospective studies for understanding fall risk and designing preventive strategies is warranted. PMID:21880615

Kinematic measures for assessing gait stability in elderly individuals: a systematic review.

PubMed

Hamacher, D; Singh, N B; Van Dieën, J H; Heller, M O; Taylor, W R

2011-12-07

Falls not only present a considerable health threat, but the resulting treatment and loss of working days also place a heavy economic burden on society. Gait instability is a major fall risk factor, particularly in geriatric patients, and walking is one of the most frequent dynamic activities of daily living. To allow preventive strategies to become effective, it is therefore imperative to identify individuals with an unstable gait. Assessment of dynamic stability and gait variability via biomechanical measures of foot kinematics provides a viable option for quantitative evaluation of gait stability, but the ability of these methods to predict falls has generally not been assessed. Although various methods for assessing gait stability exist, their sensitivity and applicability in a clinical setting, as well as their cost-effectiveness, need verification. The objective of this systematic review was therefore to evaluate the sensitivity of biomechanical measures that quantify gait stability among elderly individuals and to evaluate the cost of measurement instrumentation required for application in a clinical setting. To assess gait stability, a comparative effect size (Cohen's d) analysis of variability and dynamic stability of foot trajectories during level walking was performed on 29 of an initial yield of 9889 articles from four electronic databases. The results of this survey demonstrate that linear variability of temporal measures of swing and stance was most capable of distinguishing between fallers and non-fallers, whereas step width and stride velocity prove more capable of discriminating between old versus young (OY) adults. In addition, while orbital stability measures (Floquet multipliers) applied to gait have been shown to distinguish between both elderly fallers and non-fallers as well as between young and old adults, local stability measures (λs) have been able to distinguish between young and old adults. Both linear and nonlinear measures of foot time series during gait seem to hold predictive ability in distinguishing healthy from fall-prone elderly adults. In conclusion, biomechanical measurements offer promise for identifying individuals at risk of falling and can be obtained with relatively low-cost tools. Incorporation of the most promising measures in combined retrospective and prospective studies for understanding fall risk and designing preventive strategies is warranted.

Effects of management tactics on meeting conservation objectives for Western North American groundfish fisheries.

PubMed

Melnychuk, Michael C; Banobi, Jeannette A; Hilborn, Ray

2013-01-01

There is considerable variability in the status of fish populations around the world and a poor understanding of how specific management characteristics affect populations. Overfishing is a major problem in many fisheries, but in some regions the recent tendency has been to exploit stocks at levels below their maximum sustainable yield. In Western North American groundfish fisheries, the status of individual stocks and management systems among regions are highly variable. In this paper, we show the current status of groundfish stocks from Alaska, British Columbia, and the U.S. West Coast, and quantify the influence on stock status of six management tactics often hypothesized to affect groundfish. These tactics are: the use of harvest control rules with estimated biological reference points; seasonal closures; marine reserves; bycatch constraints; individual quotas (i.e., 'catch shares'); and gear type. Despite the high commercial value of many groundfish and consequent incentives for maintaining stocks at their most productive levels, most stocks were managed extremely conservatively, with current exploitation rates at only 40% of management targets and biomass 33% above target biomass on average. Catches rarely exceeded TACs but on occasion were far below TACs (mean catch:TAC ratio of 57%); approximately $150 million of potential landed value was foregone annually by underutilizing TACs. The use of individual quotas, marine reserves, and harvest control rules with estimated limit reference points had little overall effect on stock status. More valuable fisheries were maintained closer to management targets and were less variable over time than stocks with lower catches or ex-vessel prices. Together these results suggest there is no single effective management measure for meeting conservation objectives; if scientifically established quotas are set and enforced, a variety of means can be used to ensure that exploitation rates and biomass levels are near to or more conservative than management targets.

Inter-Individual Differences in Neurobehavioural Impairment following Sleep Restriction Are Associated with Circadian Rhythm Phase

PubMed Central

Sletten, Tracey L.; Segal, Ahuva Y.; Flynn-Evans, Erin E.; Lockley, Steven W.; Rajaratnam, Shantha M. W.

2015-01-01

Although sleep restriction is associated with decrements in daytime alertness and neurobehavioural performance, there are considerable inter-individual differences in the degree of impairment. This study examined the effects of short-term sleep restriction on neurobehavioural performance and sleepiness, and the associations between individual differences in impairments and circadian rhythm phase. Healthy adults (n = 43; 22 M) aged 22.5 ± 3.1 (mean ± SD) years maintained a regular 8:16 h sleep:wake routine for at least three weeks prior to laboratory admission. Sleep opportunity was restricted to 5 hours time-in-bed at home the night before admission and 3 hours time-in-bed in the laboratory, aligned by wake time. Hourly saliva samples were collected from 5.5 h before until 5 h after the pre-laboratory scheduled bedtime to assess dim light melatonin onset (DLMO) as a marker of circadian phase. Participants completed a 10-min auditory Psychomotor Vigilance Task (PVT), the Karolinska Sleepiness Scale (KSS) and had slow eye movements (SEM) measured by electrooculography two hours after waking. We observed substantial inter-individual variability in neurobehavioural performance, particularly in the number of PVT lapses. Increased PVT lapses (r = -0.468, p < 0.01), greater sleepiness (r = 0.510, p < 0.0001), and more slow eye movements (r = 0.375, p = 0.022) were significantly associated with later DLMO, consistent with participants waking at an earlier circadian phase. When the difference between DLMO and sleep onset was less than 2 hours, individuals were significantly more likely to have at least three attentional lapses the following morning. This study demonstrates that the phase of an individual’s circadian system is an important variable in predicting the degree of neurobehavioural performance impairment in the hours after waking following sleep restriction, and confirms that other factors influencing performance decrements require further investigation. PMID:26043207

267 Spanish Exomes Reveal Population-Specific Differences in Disease-Related Genetic Variation

PubMed Central

Dopazo, Joaquín; Amadoz, Alicia; Bleda, Marta; Garcia-Alonso, Luz; Alemán, Alejandro; García-García, Francisco; Rodriguez, Juan A.; Daub, Josephine T.; Muntané, Gerard; Rueda, Antonio; Vela-Boza, Alicia; López-Domingo, Francisco J.; Florido, Javier P.; Arce, Pablo; Ruiz-Ferrer, Macarena; Méndez-Vidal, Cristina; Arnold, Todd E.; Spleiss, Olivia; Alvarez-Tejado, Miguel; Navarro, Arcadi; Bhattacharya, Shomi S.; Borrego, Salud; Santoyo-López, Javier; Antiñolo, Guillermo

2016-01-01

Recent results from large-scale genomic projects suggest that allele frequencies, which are highly relevant for medical purposes, differ considerably across different populations. The need for a detailed catalog of local variability motivated the whole-exome sequencing of 267 unrelated individuals, representative of the healthy Spanish population. Like in other studies, a considerable number of rare variants were found (almost one-third of the described variants). There were also relevant differences in allelic frequencies in polymorphic variants, including ∼10,000 polymorphisms private to the Spanish population. The allelic frequencies of variants conferring susceptibility to complex diseases (including cancer, schizophrenia, Alzheimer disease, type 2 diabetes, and other pathologies) were overall similar to those of other populations. However, the trend is the opposite for variants linked to Mendelian and rare diseases (including several retinal degenerative dystrophies and cardiomyopathies) that show marked frequency differences between populations. Interestingly, a correspondence between differences in allelic frequencies and disease prevalence was found, highlighting the relevance of frequency differences in disease risk. These differences are also observed in variants that disrupt known drug binding sites, suggesting an important role for local variability in population-specific drug resistances or adverse effects. We have made the Spanish population variant server web page that contains population frequency information for the complete list of 170,888 variant positions we found publicly available (http://spv.babelomics.org/), We show that it if fundamental to determine population-specific variant frequencies to distinguish real disease associations from population-specific polymorphisms. PMID:26764160

Using genetics to predict the natural history of asthma?

PubMed

Holloway, John W; Arshad, Syed H; Holgate, Stephen T

2010-08-01

Clinical practice reminds us that there is considerable variability in the course of asthma over time. Treatment of patients with asthma would be considerably improved if one could accurately predict the likely course of disease over the life course. Recently, with the advent of the era of genome-wide association studies, there has been a monumental shift in our understanding of the genetic factors that underlie inherited susceptibility to asthma. Genes have been identified that modulate many aspects of the natural history of asthma, such as susceptibility to atopy, altered lung development, and susceptibility to more severe disease. Heritability studies have even suggested a role for genetic factors in remission of asthma. However, although the discovery of novel genetic factors underlying disease susceptibility has undoubtedly improved our understanding of disease pathogenesis, whether these advances have improved the ability to predict the natural history in individual patients is questionable, and the application of genetic testing to clinical practice remains some way off. Copyright 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Repeatability and Heritability of Behavioural Types in a Social Cichlid

PubMed Central

Chervet, Noémie; Zöttl, Markus; Schürch, Roger; Taborsky, Michael; Heg, Dik

2011-01-01

Aim. The quantitative genetics underlying correlated behavioural traits (‘‘animal personality”) have hitherto been studied mainly in domesticated animals. Here we report the repeatability (R) and heritability (h2) of behavioural types in the highly social cichlid fish Neolamprologus pulcher. Methods. We tested 1779 individuals repeatedly and calculated the h2 of behavioural types by variance components estimation (GLMM REML), using 1327 offspring from 162 broods from 74 pairs. Results. Repeatability of behavioural types was significant and considerable (0.546), but declined from 0.83 between tests conducted on the same day, to 0.19 on tests conducted up to 1201 days apart. All h2 estimates were significant but low (e.g., pair identity h2 = 0.15 ± 0.03 SE). Additionally, we found significant variation between broods nested within the parent(s), but these were not related to several environmental factors tested. Conclusions. We conclude that despite a considerable R, h2 in this cichlid species is low, and variability in behavioural type appears to be strongly affected by other (non)genetic effects. PMID:21716729

Effects of a 12-Week Exercise Training Program on Physical Function in Institutionalized Frail Elderly

PubMed Central

Ferreira, Cristiane Batisti; Teixeira, Pâmela dos Santos; Alves dos Santos, Geiane; Dantas Maya, Athila Teles; Americano do Brasil, Paula; Souza, Vinícius Carolino; Córdova, Cláudio; Lima, Ricardo Moreno; Nóbrega, Otávio de Toledo

2018-01-01

With the increase in life expectancy, the Brazilian elderly population has risen considerably. However, longevity is usually accompanied by problems such as the loss of functional capacity, cognitive decline, frailty syndrome, and deterioration in anthropometric parameters, particularly among those living in long-term care facilities. This randomized controlled trial aimed to verify the effects of exercise training on biochemical, inflammatory, and anthropometric indices and functional performance in institutionalized frail elderly. The sample consisted of 37 elderly people of both genders, aged 76.1 ± 7.7 years, who were randomly allocated into 2 groups: 13 individuals in the exercise group (EG) and 24 in the control group (CG). Anthropometrics, clinical history, functional tests, and biochemical evaluation were measured before and after the completion of a physical exercise program, which lasted for 12 weeks. The 12-week exercise program for frail elderly residents in a long-term care facility was efficient in improving muscle strength, speed, agility, and biochemical variables, with reversal of the frailty condition in a considerable number. However, no effects in anthropometric and inflammatory parameters were noted. PMID:29593907

Exploring the critical quality attributes and models of smart homes.

PubMed

Ted Luor, Tainyi; Lu, Hsi-Peng; Yu, Hueiju; Lu, Yinshiu

2015-12-01

Research on smart homes has significantly increased in recent years owing to their considerably improved affordability and simplicity. However, the challenge is that people have different needs (or attitudes toward smart homes), and provision should be tailored to individuals. A few studies have classified the functions of smart homes. Therefore, the Kano model is first adopted as a theoretical base to explore whether the functional classifications of smart homes are attractive or necessary, or both. Second, three models and test user attitudes toward three function types of smart homes are proposed. Based on the Kano model, the principal results, namely, two "Attractive Quality" and nine "Indifferent Quality" items, are found. Verification of the hypotheses also indicates that the entertainment, security, and automation functions are significantly correlated with the variables "perceive useful" and "attitude." Cost consideration is negatively correlated with attitudes toward entertainment and automation. Results suggest that smart home providers should survey user needs for their product instead of merely producing smart homes based on the design of the builder or engineer. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Towards an Effective Health Interventions Design: An Extension of the Health Belief Model

PubMed Central

Orji, Rita; Vassileva, Julita; Mandryk, Regan

2012-01-01

Introduction The recent years have witnessed a continuous increase in lifestyle related health challenges around the world. As a result, researchers and health practitioners have focused on promoting healthy behavior using various behavior change interventions. The designs of most of these interventions are informed by health behavior models and theories adapted from various disciplines. Several health behavior theories have been used to inform health intervention designs, such as the Theory of Planned Behavior, the Transtheoretical Model, and the Health Belief Model (HBM). However, the Health Belief Model (HBM), developed in the 1950s to investigate why people fail to undertake preventive health measures, remains one of the most widely employed theories of health behavior. However, the effectiveness of this model is limited. The first limitation is the low predictive capacity (R2 < 0.21 on average) of existing HBM’s variables coupled with the small effect size of individual variables. The second is lack of clear rules of combination and relationship between the individual variables. In this paper, we propose a solution that aims at addressing these limitations as follows: (1) we extended the Health Belief Model by introducing four new variables: Self-identity, Perceived Importance, Consideration of Future Consequences, and Concern for Appearance as possible determinants of healthy behavior. (2) We exhaustively explored the relationships/interactions between the HBM variables and their effect size. (3) We tested the validity of both our proposed extended model and the original HBM on healthy eating behavior. Finally, we compared the predictive capacity of the original HBM model and our extended model. Methods: To achieve the objective of this paper, we conducted a quantitative study of 576 participants’ eating behavior. Data for this study were collected over a period of one year (from August 2011 to August 2012). The questionnaire consisted of validated scales assessing the HBM determinants – perceived benefit, barrier, susceptibility, severity, cue to action, and self-efficacy – using 7-point Likert scale. We also assessed other health determinants such as consideration of future consequences, self-identity, concern for appearance and perceived importance. To analyses our data, we employed factor analysis and Partial Least Square Structural Equation Model (PLS-SEM) to exhaustively explore the interaction/relationship between the determinants and healthy eating behavior. We tested for the validity of both our proposed extended model and the original HBM on healthy eating behavior. Finally, we compared the predictive capacity of the original HBM model and our extended model and investigated possible mediating effects. Results: The results show that the three newly added determinants are better predictors of healthy behavior. Our extended HBM model lead to approximately 78% increase (from 40 to 71%) in predictive capacity compared to the old model. This shows the suitability of our extended HBM for use in predicting healthy behavior and in informing health intervention design. The results from examining possible relationships between the determinants in our model lead to an interesting discovery of some mediating relationships between the HBM’s determinants, therefore, shedding light on some possible combinations of determinants that could be employed by intervention designers to increase the effectiveness of their design. Conclusion: Consideration of future consequences, self-identity, concern for appearance, perceived importance, self-efficacy, perceived susceptibility are significant determinants of healthy eating behavior that can be manipulated by healthy eating intervention design. Most importantly, the result from our model established the existence of some mediating relationships among the determinants. The knowledge of both the direct and indirect relationships sheds some light on the possible combination rules. PMID:23569653

Metabolism of psilocybin and psilocin: clinical and forensic toxicological relevance.

PubMed

Dinis-Oliveira, Ricardo Jorge

2017-02-01

Psilocybin and psilocin are controlled substances in many countries. These are the two main hallucinogenic compounds of the "magic mushrooms" and both act as agonists or partial agonists at 5-hydroxytryptamine (5-HT) 2A subtype receptors. During the last few years, psilocybin and psilocin have gained therapeutic relevance but considerable physiological variability between individuals that can influence dose-response and toxicological profile has been reported. This review aims to discuss metabolism of psilocybin and psilocin, by presenting all major and minor psychoactive metabolites. Psilocybin is primarily a pro-drug that is dephosphorylated by alkaline phosphatase to active metabolite psilocin. This last is then further metabolized, psilocin-O-glucuronide being the main urinary metabolite with clinical and forensic relevance in diagnosis.

Bovine immunity - a driver for diversity in Theileria parasites?

PubMed

McKeever, Declan J

2009-06-01

Theileria parva and Theileria annulata are tick-borne parasites of cattle that infect and transform leukocytes, causing severe and often fatal parasitic leukoses. Both species provoke strong immunity against subsequent infection. However, considerable diversity is observed in field populations of each parasite and protection is only assured against homologous challenge. The life cycles of these parasites are complex and involve prolonged exposure to host and vector defence mechanisms. Although the relevant vector mechanisms are poorly defined, protective responses of cattle seem to be tightly focused and variable in their specificity between individuals. This review considers whether bovine immunity acts as a driver for diversity in T. parva and T. annulata and explores other factors that might underlie genetic variation in these parasites.

State variations in Medicaid enrollment and utilization of substance use services: Results from a National Longitudinal Study.

PubMed

Mojtabai, Ramin; Feder, Kenneth A; Kealhofer, Marc; Krawczyk, Noa; Storr, Carla; Tormohlen, Kayla N; Young, Andrea S; Olfson, Mark; Crum, Rosa M

2018-06-01

Medicaid enrollment varies considerably among states. This study examined the association of Medicaid enrollment with the use of substance health services in the longitudinal National Epidemiologic Survey on Alcohol and Related Conditions of 2001-2005. Instrumental variable methods were used to assess endogeneity of individual-level Medicaid enrollment using state-level data as instruments. Compared to the uninsured, Medicaid covered adults were more likely to use substance use disorder treatment services over the next three years. States that have opted to expand Medicaid enrollment under the Affordable Care Act will likely experience further increases in the use of these service over the coming years. Copyright © 2018 Elsevier Inc. All rights reserved.

Popularity Trajectories and Substance Use in early Adolescence.

PubMed

Moody, James; Brynildsen, Wendy D; Osgood, D Wayne; Feinberg, Mark E; Gest, Scott

2011-05-01

This paper introduces new longitudinal network data from the "Promoting School-Community-University Partnerships to Enhance Resilience" or "PROSPER" peers project. In 28 communities, grade-level sociometric friendship nominations were collected from two cohorts of middle school students as they moved from 6(th), to 9(th) grade. As an illustration and description of these longitudinal network data, this paper describes the school popularity structure, changes in popularity position, and suggests linkages between popularity trajectory and substance use. In the cross-section, we find that the network is consistent with a hierarchical social organization, but exhibits considerable relational change in both particular friends and position at the individual level. We find that both the base level of popularity and the variability of popularity trajectories effect substance use.

Attitudes towards euthanasia in Iran: the role of altruism.

PubMed

Aghababaei, Naser

2014-03-01

Altruism is arguably the quintessential moral trait, involving willingness to benefit others and unwillingness to harm them. In this study, I explored how altruism and other personality variables relate to acceptance of euthanasia. In addition, I investigated the role of culture in attitudes to subcategorical distinctions of euthanasia. 190 Iranian students completed the Attitude Towards Euthanasia scale, the HEXACO Personality Inventory-Revised, and an interest in religion measure. Higher scores on altruism, Honesty-Humility, Agreeableness, Conscientiousness and religiousness were associated with viewing euthanasia as unacceptable. As expected, altruism explained unique variance in euthanasia attitude beyond gender, religiosity and broad personality factors. Cultural and individual differences should be taken into consideration in moral psychology research and end-of-life decision-making.

Intra-Individual Variability of Physical Activity in Older Adults With and Without Mild Alzheimer's Disease.

PubMed

Watts, Amber; Walters, Ryan W; Hoffman, Lesa; Templin, Jonathan

2016-01-01

Physical activity shows promise for protection against cognitive decline in older adults with and without Alzheimer's disease (AD). To better understand barriers to adoption of physical activity in this population, a clear understanding of daily and weekly activity patterns is needed. Most accelerometry studies report average physical activity over an entire wear period without considering the potential importance of the variability of physical activity. This study evaluated individual differences in the amount and intra-individual variability of physical activity and determined whether these differences could be predicted by AD status, day of wear, age, gender, education, and cardiorespiratory capacity. Physical activity was measured via accelerometry (Actigraph GT3X+) over one week in 86 older adults with and without AD (n = 33 and n = 53, respectively). Mixed-effects location-scale models were estimated to evaluate and predict individual differences in the amount and intra-individual variability of physical activity. Results indicated that compared to controls, participants with AD averaged 21% less activity, but averaged non-significantly greater intra-individual variability. Women and men averaged similar amounts of physical activity, but women were significantly less variable. The amount of physical activity differed significantly across days of wear. Increased cardiorespiratory capacity was associated with greater average amounts of physical activity. Investigation of individual differences in the amount and intra-individual variability of physical activity provided insight into differences by AD status, days of monitor wear, gender, and cardiovascular capacity. All individuals regardless of AD status were equally consistent in their physical activity, which may have been due to a highly sedentary sample and/or the early disease stage of those participants with AD. These results highlight the value of considering individual differences in both the amount and intra-individual variability of physical activity.

Intersubject Variability in Fearful Face Processing: The Link Between Behavior and Neural Activation

PubMed Central

Doty, Tracy J.; Japee, Shruti; Ingvar, Martin; Ungerleider, Leslie G.

2014-01-01

Stimuli that signal threat show considerable variability in the extent to which they enhance behavior, even among healthy individuals. However, the neural underpinning of this behavioral variability is not well understood. By manipulating expectation of threat in an fMRI study of fearful vs. neutral face categorization, we uncovered a network of areas underlying variability in threat processing in healthy adults. We explicitly altered expectation by presenting face images at three different expectation levels: 80%, 50%, and 20%. Subjects were instructed to report as fast and as accurately as possible whether the face was fearful (signaled threat) or not. An uninformative cue preceded each face by 4 seconds (s). By taking the difference between response times (RT) to fearful compared to neutral faces, we quantified an overall fear RT bias (i.e. faster to fearful than neutral faces) for each subject. This bias correlated positively with late trial fMRI activation (8 s after the face) during unexpected fearful face trials in bilateral ventromedial prefrontal cortex, the left subgenual cingulate cortex, and the right caudate nucleus and correlated negatively with early trial fMRI activation (4 s after the cue) during expected neutral face trials in bilateral dorsal striatum and the right ventral striatum. These results demonstrate that the variability in threat processing among healthy adults is reflected not only in behavior but also in the magnitude of activation in medial prefrontal and striatal regions that appear to encode affective value. PMID:24841078

Intersubject variability in fearful face processing: the link between behavior and neural activation.

PubMed

Doty, Tracy J; Japee, Shruti; Ingvar, Martin; Ungerleider, Leslie G

2014-12-01

Stimuli that signal threat show considerable variability in the extents to which they enhance behavior, even among healthy individuals. However, the neural underpinning of this behavioral variability is not well understood. By manipulating expectation of threat in an fMRI study of fearful versus neutral face categorization, we uncovered a network of areas underlying variability in threat processing in healthy adults. We explicitly altered expectations by presenting face images at three different expectation levels: 80 %, 50 %, and 20 %. Subjects were instructed to report as quickly and accurately as possible whether the face was fearful (signaled threat) or not. An uninformative cue preceded each face by 4 s. By taking the difference between reaction times (RTs) to fearful and neutral faces, we quantified an overall fear RT bias (i.e., faster to fearful than to neutral faces) for each subject. This bias correlated positively with late-trial fMRI activation (8 s after the face) during unexpected-fearful-face trials in bilateral ventromedial prefrontal cortex, the left subgenual cingulate cortex, and the right caudate nucleus, and correlated negatively with early-trial fMRI activation (4 s after the cue) during expected-neutral-face trials in bilateral dorsal striatum and the right ventral striatum. These results demonstrate that the variability in threat processing among healthy adults is reflected not only in behavior, but also in the magnitude of activation in medial prefrontal and striatal regions that appear to encode affective value.

The performance-variability paradox, financial decision making, and the curious case of negative Hurst exponents.

PubMed

Guastello, Stephen J; Reiter, Katherine; Shircel, Anton; Timm, Paul; Malon, Matthew; Fabisch, Megan

2014-07-01

This study examined the relationship between performance variability and actual performance of financial decision makers who were working under experimental conditions of increasing workload and fatigue. The rescaled range statistic, also known as the Hurst exponent (H) was used as an index of variability. Although H is defined as having a range between 0 and 1, 45% of the 172 time series generated by undergraduates were negative. Participants in the study chose the optimum investment out of sets of 3 to 5 options that were presented a series of 350 displays. The sets of options varied in both the complexity of the options and number of options under simultaneous consideration. One experimental condition required participants to make their choices within 15 sec, and the other condition required them to choose within 7.5 sec. Results showed that (a) negative H was possible and not a result of psychometric error; (b) negative H was associated with negative autocorrelations in a time series. (c) H was the best predictor of performance of the variables studied; (d) three other significant predictors were scores on an anagrams test and ratings of physical demands and performance demands; (e) persistence as evidenced by the autocorrelations was associated with ratings of greater time pressure. It was concluded, furthermore, that persistence and overall performance were correlated, that 'healthy' variability only exists within a limited range, and other individual differences related to ability and resistance to stress or fatigue are also involved in the prediction of performance.

The Influence of Individual Variability on Zooplankton Population Dynamics under Different Environmental Conditions

NASA Astrophysics Data System (ADS)

Bi, R.; Liu, H.

2016-02-01

Understanding how biological components respond to environmental changes could be insightful to predict ecosystem trajectories under different climate scenarios. Zooplankton are key components of marine ecosystems and changes in their dynamics could have major impact on ecosystem structure. We developed an individual-based model of a common coastal calanoid copepod Acartia tonsa to examine how environmental factors affect zooplankton population dynamics and explore the role of individual variability in sustaining population under various environmental conditions consisting of temperature, food concentration and salinity. Total abundance, egg production and proportion of survival were used to measure population success. Results suggested population benefits from high level of individual variability under extreme environmental conditions including unfavorable temperature, salinity, as well as low food concentration, and selection on fast-growers becomes stronger with increasing individual variability and increasing environmental stress. Multiple regression analysis showed that temperature, food concentration, salinity and individual variability have significant effects on survival of A. tonsa population. These results suggest that environmental factors have great influence on zooplankton population, and individual variability has important implications for population survivability under unfavorable conditions. Given that marine ecosystems are at risk from drastic environmental changes, understanding how individual variability sustains populations could increase our capability to predict population dynamics in a changing environment.

The number of neurons in specific amygdala regions is associated with boldness in mink: a study in animal personality.

PubMed

Wiese, Ann-Sophie; Needham, Esther Kjær; Noer, Christina Lehmkuhl; Balsby, Thorsten Johannes Skovbjerg; Dabelsteen, Torben; Pakkenberg, Bente

2018-05-01

Conspecifics vary consistently in their behavioural responses towards environment stimuli such as exposure to novel objects; ethologists often refer to this variability as animal personality. The neurological mechanisms underlying animal personality traits remain largely unknown, but linking the individual variation in emotional expression to brain structural and neurochemical factors is attracting renewed interest. While considerable research has focused on hormonal and neurotransmitter effects on behavioural responses, less is known about how individual variation in the number of specific neuron populations contributes to individual variation in behaviour. The basolateral amygdala (BLA) and the central nuclei of the amygdala (CeA) mediate emotional processing by regulating behavioural responses of animals in a potentially threatening situation. As such, these structures are good candidates for evaluating the relationship between neuronal populations and behavioural traits. We now show that individual American mink (Neovison vison) reacting more boldly towards novelty have more neurons in the BLA than do their more timid conspecifics, suggesting that a developmental pattern of the number of amygdala neurons can influence behavioural traits of an adult animal. Furthermore, post hoc correlations revealed that individuals performing with higher arousal, as reflected by their frequency of startle behaviour, have more CeA neurons. Our results support a direct link between the number of neurons in amygdala regions and aspects of animal personality.

The income elasticity of Willingness-To-Pay (WTP) revisited: A meta-analysis of studies for restoring Good Ecological Status (GES) of water bodies under the Water Framework Directive (WFD).

PubMed

Tyllianakis, Emmanouil; Skuras, Dimitris

2016-11-01

The income elasticity of Willingness-To-Pay (WTP) is ambiguous and results from meta-analyses are disparate. This may be because the environmental good or service to be valued is very broadly defined or because the income measured in individual studies suffers from extensive non-reporting or miss reporting. The present study carries out a meta-analysis of WTP to restore Good Ecological Status (GES) under the Water Framework Directive (WFD). This environmental service is narrowly defined and its aims and objectives are commonly understood among the members of the scientific community. Besides income reported by the individual studies, wealth and income indicators collected by Eurostat for the geographic entities covered by the individual studies are used. Meta-regression analyses show that income is statistically significant, explains a substantial proportion of WTP variability and its elasticity is considerable in magnitude ranging from 0.6 to almost 1.7. Results are robust to variations in the sample of the individual studies participating in the meta-analysis, the econometric approach and the function form of the meta-regression. The choice of wealth or income measure is not that important as it is whether this measure is Purchasing Power Parity (PPP) adjusted among the individual studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Individuals with Type 1 and Type 2 Diabetes Mellitus Trade Increased Hyperglycemia for Decreased Hypoglycemia When Glycemic Variability is not Improved.

PubMed

Jangam, Sujit R; Hayter, Gary; Dunn, Timothy C

2018-02-01

Glycemic variability refers to oscillations in blood glucose within a day and differences in blood glucose at the same time on different days. Glycemic variability is linked to hypoglycemia and hyperglycemia. The relationship among these three important metrics is examined here, specifically to show how reduction in both hypo- and hyperglycemia risk is dependent on changes in variability. To understand the importance of glycemic variability in the simultaneous reduction of hypoglycemia and hyperglycemia risk, we introduce the glycemic risk plot-estimated HbA1c % (eA1c) vs. minutes below 70 mg/dl (MB70) with constant variability contours for predicting post-intervention risks in the absence of a change in glycemic variability. The glycemic risk plot illustrates that individuals who do not reduce glycemic variability improve one of the two metrics (hypoglycemia risk or hyperglycemia risk) at the cost of the other. It is important to reduce variability to improve both risks. These results were confirmed by data collected in a randomized controlled trial consisting of individuals with type 1 and type 2 diabetes on insulin therapy. For type 1, a total of 28 individuals out of 35 (80%) showed improvement in at least one of the risks (hypo and/or hyper) during the 100-day course of the study. Seven individuals (20%) showed improvement in both. Similar data were observed for type 2 where a total of 36 individuals out of 43 (84%) showed improvement in at least one risk and 8 individuals (19%) showed improvement in both. All individuals in the study who showed improvement in both hypoglycemia and hyperglycemia risk also showed a reduction in variability. Therapy changes intended to improve an individual's hypoglycemia or hyperglycemia risk often result in the reduction of one risk at the expense of another. It is important to improve glucose variability to reduce both risks or at least maintain one risk while reducing the other. Abbott Diabetes Care.

Job stressors, personality and burnout in primary school teachers.

PubMed

Kokkinos, Constantinos M

2007-03-01

Teaching is considered a highly stressful occupation. Burnout is a negative affective response occurring as a result of chronic work stress. While the early theories of burnout focused exclusively on work-related stressors, recent research adopts a more integrative approach where both environmental and individual factors are studied. Nevertheless, such studies are scarce with teacher samples. The present cross-sectional study sought to investigate the association between burnout, personality characteristics and job stressors in primary school teachers from Cyprus. The study also investigates the relative contribution of these variables on the three facets of burnout - emotional exhaustion, depersonalization and reduced personal accomplishment. A representative sample of 447 primary school teachers participated in the study. Teachers completed measures of burnout, personality and job stressors along with demographic and professional data. Surveys were delivered by courier to schools, and were distributed at faculty meetings. Results showed that both personality and work-related stressors were associated with burnout dimensions. Neuroticism was a common predictor of all dimensions of burnout although in personal accomplishment had a different direction. Managing student misbehaviour and time constraints were found to systematically predict dimensions of burnout. Teachers' individual characteristics as well as job related stressors should be taken into consideration when studying the burnout phenomenon. The fact that each dimension of the syndrome is predicted by different variables should not remain unnoticed especially when designing and implementing intervention programmes to reduce burnout in teachers.

Orofacial functions and oral health associated with Treacher Collins syndrome.

PubMed

Asten, Pamela; Skogedal, Nina; Nordgarden, Hilde; Axelsson, Stefan; Akre, Harriet; Sjögreen, Lotta

2013-01-01

The aim of this study was to describe orofacial features and functions and oral health associated with Treacher Collins syndrome (TCS) in relation to the variable phenotypic expression of the condition. The Nordic Orofacial Test-Screening (NOT-S), MHC Questionnaire, MHC Observation chart and clinical examinations of nasal and pharyngeal conditions and chewing and swallowing function were used to assess 19 individuals aged 5-74 years (median 34 years). TCS severity scores were calculated by a clinical geneticist. Orofacial features characterizing the study group were altered profile, increased mandibular angle, narrow hypopharynx and facial asymmetry. Basic orofacial functions such as breathing, eating, facial expression and speech were affected in all subjects demonstrating orofacial dysfunction in at least two NOT-S domains (median NOT-S total score 4/12, range 2-7). Significant correlation was found between the TCS severity scores reflecting phenotypic expression and the NOT-S total scores reflecting orofacial function. Self-reported experience of dry oral mucosa was common. Overall, dental health was good with few carious lesions diagnosed, but considerable need for orthodontic treatment was documented. Altered orofacial features and functions in TCS are common and often persist into late adolescence and adulthood. The functional level was correlated with the phenotypic variability of the condition. The standard of oral health was satisfactory. The findings indicated that individuals with TCS are likely to require lifelong health services related to their oral condition.

Determinants of physiological and perceived physiological stress reactivity in children and adolescents.

PubMed

Evans, Brittany E; Greaves-Lord, Kirstin; Euser, Anja S; Tulen, Joke H M; Franken, Ingmar H A; Huizink, Anja C

2013-01-01

Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related) of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. In a stratified sample of 363 children (7-12 years) and 344 adolescents (13-20 years) from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness.

What do patients with epilepsy tell us about language dynamics? A review of fMRI studies.

PubMed

Baciu, Monica; Perrone-Bertolotti, Marcela

2015-01-01

The objective of this review is to resume major neuroimaging findings on language organization and plasticity in patients with focal and refractory epilepsy, to discuss the effect of modulatory variables that should be considered alongside patterns of reorganization, and to propose possible models of language reorganization. The focal and refractory epilepsy provides a real opportunity to investigate various types of language reorganization in different conditions. The 'chronic' condition (induced by the epileptogenic zone or EZ) is associated with either recruitment of homologous regions of the opposite hemisphere or recruitment of intrahemispheric, nonlinguistic regions. In the 'acute' condition (neurosurgery and EZ resection), the initial interhemispheric shift (induced by the chronic EZ) could follow a reverse direction, back to the initial hemisphere. These different patterns depend on several modulatory factors and are associated with various levels of language performance. As a neuroimaging tool, functional magnetic resonance imaging enables the detailed investigation of both hemispheres simultaneously and allows for comparison with healthy controls, potentially creating a more comprehensive and more realistic picture of brain-language relations. Importantly, functional neuroimaging approaches demonstrate a good degree of concordance on a theoretical level, but also a considerable degree of individual variability, attesting to the clinical importance with these methods to establish, empirically, language localization in individual patients. Overall, the unique features of epilepsy, combined with ongoing advances in technology, promise further improvement in understanding of language substrate.

Identifying Variations in Hydraulic Conductivity on the East River at Crested Butte, CO

NASA Astrophysics Data System (ADS)

Ulmer, K. N.; Malenda, H. F.; Singha, K.

2016-12-01

Slug tests are a widely used method to measure saturated hydraulic conductivity, or how easily water flows through an aquifer, by perturbing the piezometric surface and measuring the time the local groundwater table takes to re-equilibrate. Saturated hydraulic conductivity is crucial to calculating the speed and direction of groundwater movement. Therefore, it is important to document data variance from in situ slug tests. This study addresses two potential sources of data variability: different users and different types of slug used. To test for user variability, two individuals slugged the same six wells with water multiple times at a stream meander on the East River near Crested Butte, CO. To test for variations in type of slug test, multiple water and metal slug tests were performed at a single well in the same meander. The distributions of hydraulic conductivities of each test were then tested for variance using both the Kruskal-Wallis test and the Brown-Forsythe test. When comparing the hydraulic conductivity distributions gathered by the two individuals, we found that they were statistically similar. However, we found that the two types of slug tests produced hydraulic conductivity distributions for the same well that are statistically dissimilar. In conclusion, multiple people should be able to conduct slug tests without creating any considerable variations in the resulting hydraulic conductivity values, but only a single type of slug should be used for those tests.

Subcloning the RBL-2H3 mucosal mast cell line reduces Ca2+ response heterogeneity at the single-cell level.

PubMed

Kuchtey, J; Fewtrell, C

1996-03-01

Ca2+ imaging experiments have revealed that for a wide variety of cell types, including RBL-2H3 mucosal mast cells, there are considerable cell-to-cell differences of the Ca2+ responses of individual cells. This heterogeneity is evident in both the shape and latency of the responses. Mast cells within a single microscopic field of view, which have experienced identical culture conditions and experimental preparation, display a wide variety of responses upon antigen stimulation. We have subcloned the RBL-2H3 mucosal mast cell line to test the hypothesis that genetic heterogeneity within the population is the cause of the Ca2+ response heterogeneity. We found that cell-to-cell variability was significantly reduced in four of five clonal lines. The response heterogeneity remaining within the clones was not an experimental artifact caused by differences in the amount of fura-2 loaded by individual cells. Factors other than genetic heterogeneity must partly account for Ca2+ response heterogeneity. It is possible that the complex shapes and variability of the Ca2+ responses are reflections of the fact that there are multiple factors underlying the Ca2-response to antigen stimulation. Small differences from cell to cell in one or more of these factors could be a cause of the remaining Ca2+ response heterogeneity.

On X-Ray Variability in Seyfert Galaxies

NASA Technical Reports Server (NTRS)

Turner, T. J.; George, I. M.; Nandra, K.; Turcan, D.

1999-01-01

This paper presents a quantification of the X-ray variability amplitude for 79 ASCA observations of 36 Seyfert 1 galaxies. We find that consideration of sources with the narrowest permitted lines in the optical band introduces scatter into the established correlation between X-ray variability and nuclear luminosity. Consideration of the X-ray spectral index and variability properties together shows distinct groupings in parameter space for broad and narrow-line Seyfert 1 galaxies, confirming previous studies. A strong correlation is found between hard X-ray variability and FWHM Hbeta. A range of nuclear mass and accretion rate across the Seyfert population can explain the differences observed in X-ray and optical properties. An attractive alternative model, which does not depend on any systematic difference in central mass, is that the circumnuclear gas of NLSy1s is different to BLSy1s in temperature, optical depth, density or geometry.

Variables related to romanticism and self-esteem in pregnant teenagers.

PubMed

Medora, N P; Goldstein, A; von der Hellen, C

1993-01-01

In this study, the Dean Romanticism Scale and the Bachman Self-esteem Scale were administered to 121 teenagers between the ages of 12 and 19 in Southern California to investigate their degree of romanticism and self-esteem. The study also explored whether there was any relationship between the dependent variables of romanticism and self-esteem and ten independent variables--age, race, place of residence during pregnancy, age when first sexual intercourse occurred, age when pregnancy occurred, incidence of sexual abuse, incidence of abortion, adoption considerations, whether the subject was currently sexually active, and whether the teenager planned to have a child with the father of the baby. The results indicated that two variables were significantly related to feelings of romanticism--adoption considerations and whether the adolescent planned to have a child with the baby's father. In addition, two variables were significantly related to self-esteem--the incidence of sexual abuse and the incidence of abortion.

Shoulder pain and time dependent structure in wheelchair propulsion variability

PubMed Central

Jayaraman, Chandrasekaran; Moon, Yaejin; Sosnoff, Jacob J.

2016-01-01

Manual wheelchair propulsion places considerable repetitive mechanical strain on the upper limbs leading to shoulder injury and pain. While recent research indicates that the amount of variability in wheelchair propulsion and shoulder pain may be related. There has been minimal inquiry into the fluctuation over time (i.e. time-dependent structure) in wheelchair propulsion variability. Consequently the purpose of this investigation was to examine if the time-dependent structure in the wheelchair propulsion parameters are related to shoulder pain. 27 experienced wheelchair users manually propelled their own wheelchair fitted with a SMARTWheel on a roller at 1.1 m/s for 3 minutes. Time-dependent structure of cycle-to-cycle fluctuations in contact angle and inter push time interval was quantified using sample entropy (SampEn) and compared between the groups with/without shoulder pain using non-parametric statistics. Overall findings were, (1) variability observed in contact angle fluctuations during manual wheelchair propulsion is structured (Z=3.15;p<0.05), (2) individuals with shoulder pain exhibited higher SampEn magnitude for contact angle during wheelchair propulsion than those without pain (χ2(1)=6.12;p<0.05); and (3) SampEn of contact angle correlated significantly with self-reported shoulder pain (rs (WUSPI) =0.41;rs (VAS)=0.56;p<0.05). It was concluded that the time-dependent structure in wheelchair propulsion may provide novel information for tracking and monitoring shoulder pain. PMID:27134151

The nuclear 18S ribosomal RNA gene as a source of phylogenetic information in the genus Taenia.

PubMed

Yan, Hongbin; Lou, Zhongzi; Li, Li; Ni, Xingwei; Guo, Aijiang; Li, Hongmin; Zheng, Yadong; Dyachenko, Viktor; Jia, Wanzhong

2013-03-01

Most species of the genus Taenia are of considerable medical and veterinary significance. In this study, complete nuclear 18S rRNA gene sequences were obtained from seven members of genus Taenia [Taenia multiceps, Taenia saginata, Taenia asiatica, Taenia solium, Taenia pisiformis, Taenia hydatigena, and Taenia taeniaeformis] and a phylogeny inferred using these sequences. Most of the variable sites fall within the variable regions, V1-V5. We show that sequences from the nuclear 18S ribosomal RNA gene have considerable promise as sources of phylogenetic information within the genus Taenia. Furthermore, given that almost all the variable sites lie within defined variable portions of that gene, it will be appropriate and economical to sequence only those regions for additional species of Taenia.

Socioeconomic and Cultural Correlates of Diet Quality in the Canadian Arctic: Results from the 2007-2008 Inuit Health Survey.

PubMed

Galloway, Tracey; Johnson-Down, Louise; Egeland, Grace M

2015-09-01

We examined the impact of socioeconomic and cultural factors on dietary quality in adult Inuit living in the Canadian Arctic. Interviews and a 24-h dietary recall were administered to 805 men and 1292 women from Inuit regions in the Canadian Arctic. We examined the effect of age, sex, education, income, employment, and cultural variables on respondents' energy, macronutrient intake, sodium/potassium ratio, and healthy eating index. Logistic regression was used to assess the impact of socioeconomic status (SES) on diet quality indicators. Age was positively associated with traditional food (TF) consumption and greater energy from protein but negatively associated with total energy and fibre intake. Associations between SES and diet quality differed considerably between men and women and there was considerable regional variability in diet quality measures. Age and cultural variables were significant predictors of diet quality in logistic regression. Increased age and use of the Inuit language in the home were the most significant predictors of TF consumption. Our findings are consistent with studies reporting a nutrition transition in circumpolar Inuit. We found considerable variability in diet quality and complex interaction between SES and cultural variables producing mixed effects that differ by age and gender.

Operant Variability: Procedures and Processes

ERIC Educational Resources Information Center

Machado, Armando; Tonneau, Francois

2012-01-01

Barba's (2012) article deftly weaves three main themes in one argument about operant variability. From general theoretical considerations on operant behavior (Catania, 1973), Barba derives methodological guidelines about response differentiation and applies them to the study of operant variability. In the process, he uncovers unnoticed features of…

Sexual behavior of gender-dysphoric individuals before gender-confirming interventions: a European multicenter study.

PubMed

Cerwenka, Susanne; Nieder, Timo O; Cohen-Kettenis, Peggy; De Cuypere, Griet; Haraldsen, Ira R Hebold; Kreukels, Baudewijntje P C; Richter-Appelt, Hertha

2014-01-01

A transsexual course of development that starts before puberty (early onset) or during or after puberty, respectively (late onset), may lead to diverse challenges in coping with sexual activity. The authors explored the sexual behavior of 380 adult male-to-female and female-to-male individuals diagnosed according to DSM-IV-TR criteria who had not yet undergone gender-confirming interventions. Data originated from the European Network for the Investigation of Gender Incongruence Initiative, conducted in Belgium, Germany, The Netherlands, and Norway. Information on outcome variables was collected using self-administered questionnaires at first clinical presentation. Compared with late-onset male-to-females, early-onset individuals tended to show sexual attraction toward males more frequently (50.5%), involve genitals less frequently in partner-related sexual activity, and consider penile sensations and orgasm as more negative. Early-onset female-to-males predominantly reported sexual attraction toward females (84.0%), whereas those with a late-onset more frequently showed other sexual attractions (41.7%). The study (a) shows that early- and late-onset male-to-females differ considerably with regard to coping strategies involving their body during sexual relations and (b) reveals initial insights into developmental pathways of late-onset female-to-males.

Nicotine in environmental tobacco smoke (ETS): Comparison of mobile personal and stationary area sampling

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

Jenkins, R.A.; Moody, R.L.; Higgins, C.E.

1991-01-01

Previous investigations of personal vs. area sampling of ambient nicotine may not accurately reflect personal exposure to ETS nicotine in environments in which individuals are relatively mobile. The purpose of this study was to determine the extent to which a stationary area sampler could estimate actual personal exposure to ambient nicotine when the exposed individuals are moving in and through a field environment. For this study, personal samplers using Tenax, and area samplers using XAD-4, were employed. Evaluations of the two systems using controlled experimental atmospheres of ETS revealed no differences in the measured nicotine levels over a range ofmore » 1.0--150 {mu}g/m{sup 3}. Field studies were conductd at approximately 30 locations, including taverns, restaurants with salad bars, laundromats, gaming establishments, and transportation waiting areas. Ambient nicotine levels ranged from 0.0--90.6 {mu}g/m{sup 3}. There were considerable differences in individual nicotine levels over relatively short distances within a given environment, probably due to atmospheric inhomogeneities. The variability between duplicate samples of a particular type was such that no statistically significant difference between stationary area and mobile personal samplers could be discerned. 17 refs., 2 tabs.« less

Trajectories of autonomy development across the adolescent transition in children with spina bifida.

PubMed

Friedman, Deborah; Holmbeck, Grayson N; DeLucia, Christian; Jandasek, Barbara; Zebracki, Kathy

2009-02-01

The current study investigated individual growth in autonomy development across the adolescent transition, comparing the trajectories of children with and without spina bifida. Individual growth curve modeling procedures were utilized to describe the developmental course of autonomy across four waves of data collection, from ages 9 to 15, and to test whether illness status [spina bifida vs. matched comparison group (N = 68 for both groups at Time 1)] would significantly predict individual variability in autonomy development. Potential moderators [child gender, SES, and Peabody Picture Vocabulary Test (PPVT) score] of the association between illness status and autonomy development were also examined. Children with spina bifida demonstrated distinct developmental trajectories, though the nature of the group differences varied by type of autonomy development (emotional vs. behavioral), context (i.e. school vs. family), and reporter. Significant interactions with PPVT score and child gender were found. Overall, children with spina bifida show considerable developmental resiliency, but may lag behind their peers in specific areas of autonomy. Boys with spina bifida, and children with spina bifida who have lower than average levels of verbal intelligence, appear to be at greater risk for exhibiting delays in autonomy development.

Individualism and collectivism: what differences between Portuguese and Romanian adolescents?

PubMed

Ciochină, Laura; Faria, Luísa

2009-11-01

This article presents the results of a series of preliminary comparisons, between the Portuguese and Romanian cultural contexts, on the individualism-collectivism (IND/COL) cultural dimension. The IND/COL was evaluated with the Individualism-Collectivism Questionnaire - ICQ -, constructed in New Zealand by Shulruf, Hattie and Dixon (2003, Anonymous Questionnaire of Self-Attitudes - AQSA), and adapted to the Portuguese and Romanian contexts by Ciochină and Faria (2007), using studies of confirmatory factor analysis. The ICQ composed by 26 items, 15 evaluating the IND scale--with three subscales (Uniqueness, Competition and Responsibility)--, and 11 evaluating the COL scale--with two subscales (Harmony and Advice)--, was administered to 395 subjects, 200 Portuguese and 195 Romanian, 10th and 12th graders. On the whole, in the Portuguese and Romanian samples, the multivariate and univariate statistical analyses evidenced the existence of two independent variables--gender and cultural context--, with significant effects, main and of interaction, on the scales and subscales of the ICQ. The results were discussed taking into consideration the specificities of the educational systems in the two cultural contexts, which are inevitably shaped by socio-cultural factors characteristic of the two countries considered in the present study--Portugal and Romania.

Music therapy for chronic tinnitus: variability of tinnitus pitch in the course of therapy.

PubMed

Hutter, Elisabeth; Grapp, Miriam; Argstatter, Heike; Bolay, Hans Volker

2014-04-01

In general, tinnitus pitch has been observed to be variable across time for most patients experiencing tinnitus. Some tinnitus therapies relate to the dominant tinnitus pitch in order to adjust therapeutic interventions. As studies focusing on tinnitus pitch rarely conduct consecutive pitch matching in therapeutic settings, little is known about the course and variability of tinnitus pitch during therapeutic interventions. The purpose of this study was to investigate the variability and development of tinnitus pitch in the course of therapeutic interventions. Tinnitus pitch was suspected to be highly variable. The researchers conducted a descriptive, retrospective analysis of data. A total of 175 adult patients experiencing chronic tinnitus served as participants. All patients had received a neuro-music therapy according to the "Heidelberg Model of Music Therapy for Chronic Tinnitus." During therapeutic interventions lasting for 5 consecutive days, the individual tinnitus frequency was assessed daily by means of a tinnitus pitch-matching procedure. The extent of variability in tinnitus pitch was calculated by mean ratios of frequencies between subsequent tinnitus measurements. Analysis of variance of repeated measures and post hoc paired samples t-tests were used for comparison of means in tinnitus frequencies, and the test-retest reliability of measurements was obtained by the Pearson product-moment correlation coefficient. Tinnitus pitch displayed a variability of approximately 3/5 to 4/5 octaves per day. Overall, the mean frequency declined in the course of the therapy. Detailed analysis revealed three groups of patients with diverging tinnitus progression. The test-retest reliability between assessments turned out to be robust (r = 0.74 or higher). Considerable variation in tinnitus pitch was found. Consequently, a frequent rechecking of tinnitus frequency is suggested during frequency-specific acoustic stimulation in order to train appropriate frequency bands. American Academy of Audiology.

Animal social networks as substrate for cultural behavioural diversity.

PubMed

Whitehead, Hal; Lusseau, David

2012-02-07

We used individual-based stochastic models to examine how social structure influences the diversity of socially learned behaviour within a non-human population. For continuous behavioural variables we modelled three forms of dyadic social learning, averaging the behavioural value of the two individuals, random transfer of information from one individual to the other, and directional transfer from the individual with highest behavioural value to the other. Learning had potential error. We also examined the transfer of categorical behaviour between individuals with random directionality and two forms of error, the adoption of a randomly chosen existing behavioural category or the innovation of a new type of behaviour. In populations without social structuring the diversity of culturally transmitted behaviour increased with learning error and population size. When the populations were structured socially either by making individuals members of permanent social units or by giving them overlapping ranges, behavioural diversity increased with network modularity under all scenarios, although the proportional increase varied considerably between continuous and categorical behaviour, with transmission mechanism, and population size. Although functions of the form e(c)¹(m)⁻(c)² + (c)³(Log(N)) predicted the mean increase in diversity with modularity (m) and population size (N), behavioural diversity could be highly unpredictable both between simulations with the same set of parameters, and within runs. Errors in social learning and social structuring generally promote behavioural diversity. Consequently, social learning may be considered to produce culture in populations whose social structure is sufficiently modular. Copyright © 2011 Elsevier Ltd. All rights reserved.

Intra-individual variability in tinnitus patients : current thoughts and perspectives.

PubMed

Dauman, N; Erlandsson, S; Lundlin, L; Dauman, R

2015-04-01

Most tinnitus studies have attempted to compare groups of individuals, thus revealing inter-individuals differences, i.e., variations between compared subjects. For methodological reasons, inter-individual studies cannot take into account the variability of tinnitus experience, which has been known for decades to be relevant in daily practice with tinnitus patients. The concept of intra-individual variability has been promoted in the research literature, in order to shed light on this aspect of individual perception. In previous studies, unrelated to hearing, the concept of intra-individual variability implied inclusion of the environment (i.e., physical and social interactions) as a factor of individual performance. In tinnitus research, we believe that the concept of variability (within a person) could find a place beside the concept of variation (between groups of subjects). In this paper, four perspectives of tinnitus experiences from the clinical and research fields are described: (1) ENT consultation; (2) short-term group psychotherapy; (3) psychodynamic psychotherapy; and (4) clinical psychological research. Intra-individual variability stresses the importance of defining tinnitus in a dynamic way, contrary to the current definition of tinnitus as the perception of sound(s). In clinical practice, it is useful to embrace the perspective of the perceiver of tinnitus, and to include social and cultural circumstances as well as audiological/physical changes.

Short-term favorable weather conditions are an important control of interannual variability in carbon and water fluxes

Treesearch

Jakob Zscheischler; Simone Fatichi; Sebastian Wolf; Peter D. Blanken; Gil Bohrer; Ken Clark; Ankur R. Desai; David Hollinger; Trevor Keenan; Kimberly A. Novick; Sonia I. Seneviratne

2016-01-01

Ecosystem models often perform poorly in reproducing interannual variability in carbon and water fluxes, resulting in considerable uncertainty when estimating the land-carbon sink. While many aggregated variables (growing season length, seasonal precipitation, or temperature) have been suggested as predictors for interannual variability in carbon fluxes, their...

Extreme Response Style and the Measurement of Intra-Individual Variability

ERIC Educational Resources Information Center

Deng, Sien

2017-01-01

Psychologists have become increasingly interested in the intra-individual variability of psychological measures as a meaningful distinguishing characteristic of persons. Assessments of intra-individual variability are frequently based on the repeated administration of self-report rating scale instruments, and extreme response style (ERS) has the…

Some chronobiological considerations related to physical exercise.

PubMed

Reilly, T; Atkinson, G; Gregson, W; Drust, B; Forsyth, J; Edwards, B; Waterhouse, J

2006-01-01

Variables associated with physical activity show circadian rhythms in resting subjects; these rhythms have both exogenous (due to the individual's lifestyle and environment) and endogenous (due to the "body clock") components. During exercise, many of the rhythms persist, even though some show decreasing amplitude with increasing severity of exercise. Whilst the value of physical fitness is not disputed (for elite athletes, for individuals who just want to be physically fit, or for patients undertaking physical rehabilitation regimens), there are certain times of the day when special care is needed. These times are soon after waking--when there is the possibility of an increased risk of cardiovascular morbidity and damage to the spine--and late in the day--when there is an increased risk of respiratory difficulties. Since physical exercise is inextricably linked with thermoregulation, there are special considerations to bear in mind when exercise takes place in cold or hot environments. Further, due to the effects of the body clock, exercise and activity during night work and after time-zone transitions presents problems peculiar to these circumstances. In addition, the menstrual cycle affects physical performance, and these circatrigintan rhythms interact with the circadian ones. Bearing in mind these factors, advice that is based upon knowledge of circadian and circatrigintan rhythms can be given to all those contemplating physical activity. Chronobiologically, there is advantage in undertaking physical activity programmes towards the middle of the waking day and not at times when a sleep or nap has just been taken.

Warfarin Pharmacogenomics in Diverse Populations.

PubMed

Kaye, Justin B; Schultz, Lauren E; Steiner, Heidi E; Kittles, Rick A; Cavallari, Larisa H; Karnes, Jason H

2017-09-01

Genotype-guided warfarin dosing algorithms are a rational approach to optimize warfarin dosing and potentially reduce adverse drug events. Diverse populations, such as African Americans and Latinos, have greater variability in warfarin dose requirements and are at greater risk for experiencing warfarin-related adverse events compared with individuals of European ancestry. Although these data suggest that patients of diverse populations may benefit from improved warfarin dose estimation, the vast majority of literature on genotype-guided warfarin dosing, including data from prospective randomized trials, is in populations of European ancestry. Despite differing frequencies of variants by race/ethnicity, most evidence in diverse populations evaluates variants that are most common in populations of European ancestry. Algorithms that do not include variants important across race/ethnic groups are unlikely to benefit diverse populations. In some race/ethnic groups, development of race-specific or admixture-based algorithms may facilitate improved genotype-guided warfarin dosing algorithms above and beyond that seen in individuals of European ancestry. These observations should be considered in the interpretation of literature evaluating the clinical utility of genotype-guided warfarin dosing. Careful consideration of race/ethnicity and additional evidence focused on improving warfarin dosing algorithms across race/ethnic groups will be necessary for successful clinical implementation of warfarin pharmacogenomics. The evidence for warfarin pharmacogenomics has a broad significance for pharmacogenomic testing, emphasizing the consideration of race/ethnicity in discovery of gene-drug pairs and development of clinical recommendations for pharmacogenetic testing. © 2017 Pharmacotherapy Publications, Inc.

The association between time perspective and alcohol consumption in university students: cross-sectional study.

PubMed

Beenstock, Jane; Adams, Jean; White, Martin

2011-08-01

Heavy alcohol consumption is associated with significant morbidity and mortality. Levels of alcohol consumption among students and young people are particularly high. Time perspective describes the varying value individuals place on outcomes in the present and future. In general, it has been found that individuals prefer to receive a gain today rather than in the future. There is evidence that time perspective is associated with addictive health behaviours, including alcoholism and cigarette smoking, but less evidence of its association with non-addictive, but hazardous, levels of alcohol consumption. The objective was to determine if there is an association between time perspective and hazardous alcohol consumption. A cross-sectional survey using a self-completion questionnaire was administered to willing undergraduate students attending a convenience sample of lectures in two university faculties. Hazardous alcohol consumption was defined as a score of ≥8 on the Alcohol Use Disorders Identification Test (AUDIT) and time perspective was measured using the Consideration of Future Consequences Scale (CFCS). Participants were 322 undergraduate university students in two faculties at a university in Northern England, UK. Hazardous alcohol consumption was reported by 264 (82%) respondents. After controlling for potential confounding by socio-demographic variables, greater consideration of future consequences was associated with lower odds of reporting hazardous drinking [odds ratio = 0.28; 95% confidence interval 0.15-0.54]. Interventions aimed at increasing future orientated time perspective may be effective in decreasing hazardous alcohol consumption in students.

Intra- and inter-individual variation of BIS-index and Entropy during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers: an interventional study.

PubMed

Haenggi, Matthias; Ypparila-Wolters, Heidi; Hauser, Kathrin; Caviezel, Claudio; Takala, Jukka; Korhonen, Ilkka; Jakob, Stephan M

2009-01-01

We studied intra-individual and inter-individual variability of two online sedation monitors, BIS and Entropy, in volunteers under sedation. Ten healthy volunteers were sedated in a stepwise manner with doses of either midazolam and remifentanil or dexmedetomidine and remifentanil. One week later the procedure was repeated with the remaining drug combination. The doses were adjusted to achieve three different sedation levels (Ramsay Scores 2, 3 and 4) and controlled by a computer-driven drug-delivery system to maintain stable plasma concentrations of the drugs. At each level of sedation, BIS and Entropy (response entropy and state entropy) values were recorded for 20 minutes. Baseline recordings were obtained before the sedative medications were administered. Both inter-individual and intra-individual variability increased as the sedation level deepened. Entropy values showed greater variability than BIS(R) values, and the variability was greater during dexmedetomidine/remifentanil sedation than during midazolam/remifentanil sedation. The large intra-individual and inter-individual variability of BIS and Entropy values in sedated volunteers makes the determination of sedation levels by processed electroencephalogram (EEG) variables impossible. Reports in the literature which draw conclusions based on processed EEG variables obtained from sedated intensive care unit (ICU) patients may be inaccurate due to this variability. clinicaltrials.gov Nr. NCT00641563.

Hearing Assistive Technology Considerations for Older Individuals With Dual Sensory Loss

PubMed Central

Kricos, Patricia B.

2007-01-01

This article focuses on the current state of the science related to audiologic rehabilitation of individuals with dual sensory impairment, with an emphasis on considerations for provision of appropriate hearing assistive technology for this population. A substantial increase in the number of older adults is predicted in the coming years, many of whom will have significant age-related impairments in hearing and vision. Thus, hearing care professionals will be called on increasingly to attend to the special needs of people with dual sensory impairment to ensure maximal quality of life and independence for these individuals. Access to sound is critical for individuals who live with compromises in both vision and hearing. Hearing assistive technology may improve not only their speech perception but also their connection and orientation to the environment, as well as enable greater mobility. Thus, the audiologist's provision of appropriate and carefully selected hearing assistive technology may contribute dramatically to the quality of life of the individual with dual sensory loss. Prefitting, fitting, and postfitting considerations in providing hearing aids and other assistive technology to individuals with dual sensory impairment are reviewed. PMID:18080391

[Effects of situational and individual variables on critical thinking expression].

PubMed

Tanaka, Yuko; Kusumi, Takashi

2016-04-01

The present study examined when people decide to choose an expression that is based on critical thinking, and how situational and individual variables affect such a decision process. Given a conversation scenario including overgeneralization with two friends, participants decided whether to follow the conversation by a critical-thinking expression or not. The authors controlled purpose and topic as situational variables, and measured critical-thinking ability, critical-thinking disposition, and self-monitoring as individual variables. We conducted an experiment in which the situational variables were counterbalanced in a within-subject design with 60 university students. The results of logistic regression analysis showed differences within individuals in the decision process whether to choose a critical-thinking expression, and that some situational factors and some subscales of the individual measurements were related to the differences.

Influence of flexibility and variability of working hours on health and well-being.

PubMed

Costa, Giovanni; Sartori, Samantha; Akerstedt, Torbjorn

2006-01-01

Flexible working hours can have several meanings and can be arranged in a number of ways to suit the worker and/or employer. Two aspects of "flexible" arrangement of working hours were considered: one more subjected to company control and decision (variability) and one more connected to individual discretion and autonomy (flexibility). The aim of the study was to analyze these two dimensions in relation to health and well-being, taking into consideration the interaction with some relevant background variables related to demographics plus working and social conditions. The dataset of the Third European Survey on working conditions, conducted in 2000 and involving 21,505 workers, was used. Nineteen health disorders and four psycho-social conditions were tested by means of multiple logistic regression analysis, in which mutually adjusted odds ratios were calculated for age, gender, marital status, number of children, occupation, mode of employment, shift work, night work, time pressure, mental and physical workload, job satisfaction, and participation in work organization. The flexibility and variability of working hours appeared inversely related to health and psycho-social well-being: the most favorable effects were associated with higher flexibility and lower variability. The analysis of the interactions with the twelve intervening variables showed that physical work, age, and flexibility are the three most important factors affecting health and well-being. Flexibility resulted as the most important factor to influence work satisfaction; the second to affect family and social commitment and the ability to do the same job when 60 years old, as well as trauma, overall fatigue, irritability, and headache; and the third to influence heart disease, stomachache, anxiety, injury, and the feeling that health being at risk because of work. Variability was the third most important factor influencing family and social commitments. Moreover, shift and night work confirmed to have a significant influence on sleep, digestive and cardiovascular troubles, as well and health and safety at work. Time pressure also showed a relevant influence, both on individual stress and social life. Therefore, suitable arrangements of flexible working time, aimed at supporting workers' coping strategies, appear to have a clear beneficial effect on worker health and well-being, with positive consequences also at the company and social level, as evidenced by the higher "feeling to be able to work until 60 years of age".

A meta-analysis of variability in continuous-culture ruminal fermentation and digestibility data.

PubMed

Hristov, A N; Lee, C; Hristova, R; Huhtanen, P; Firkins, J L

2012-09-01

A meta-analysis was conducted to compare ruminal fermentation and digestibility data and variability between continuous-culture (CC) experiments and in vivo data. One hundred eighty CC studies representing 1,074 individual treatments, published in refereed journals between 1980 and 2010 were used in this analysis. Studies were classified into 2 groups based on the type of CC used: CC systems specified as rumen simulation techniques (RUSITEC) and non-RUSITEC CC systems (non-RUSITEC). The latter was a diverse group of systems, all of which were termed CC by the investigators. The CC data were compared with a data set of in vivo trials with ruminally cannulated lactating dairy cows (data from a total of 366 individual cows). The reported neutral detergent fiber (NDF) concentration of the diets fed in the 3 data sets was, on average (dry matter basis), 44, 34, and 32%, respectively. The average total volatile fatty acid (VFA) concentration for the RUSITEC and non-RUSITEC data sets was 67 and 80% (respectively) of the total VFA concentration in vivo. The average concentration of acetate was also lower for the CC data sets compared with in vivo and that of propionate was considerably lower for RUSITEC compared with in vivo, but butyrate concentrations were similar between the CC and in vivo data sets. Variability in the VFA data was generally the highest (higher coefficients of variation and variance) for the non-RUSITEC data set, followed by RUSITEC, and was the lowest for in vivo. Digestibilities of NDF and particularly organic matter were lower in the CC data sets compared with in vivo; the average NDF digestibility was 34.2, 45.5, and 53.0% for RUSITEC, non-RUSITEC, and in vivo, respectively. Variability in nutrient digestibility data followed the pattern of variability of the VFA data: highest variability for the non-RUSITEC data set, followed by RUSITEC, and the lowest for in vivo. This analysis showed that CC systems are generally characterized by lower total VFA and acetate concentrations, extremely low counts or lack of ruminal protozoa, and lower organic matter and NDF digestibilities than in vivo. Overall, variability was much greater for CC than for in vivo experimental data. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Nonlinearities, scale-dependence, and individualism of boreal forest trees to climate forcing

NASA Astrophysics Data System (ADS)

Wolken, J. M.; Mann, D. H.; Grant, T. A., III; Lloyd, A. H.; Hollingsworth, T. N.

2013-12-01

Our understanding of the climate-growth relationships of trees are complicated by the nonlinearity and variability of these responses through space and time. Furthermore, trees growing at the same site may exhibit opposing growth responses to climate, a phenomenon termed growth divergence. To date the majority of dendrochronological studies in Interior Alaska have involved white spruce growing at treeline, even though black spruce is the most abundant tree species. Although changing climate-growth relationships have been observed in black spruce, there is little known about the multivariate responses of individual trees to temperature and precipitation and whether or not black spruce exhibits growth divergences similar to those documented for white spruce. To evaluate the occurrence of growth divergences in black spruce, we collected cores from trees growing on a steep, north-facing toposequence having a gradient in environmental parameters. Our overall goal was to assess how the climate-growth relationships of black spruce change over space and time. Specifically, we evaluated how topography influences the climate-growth relationships of black spruce and if the growth responses to climate are homogeneous. At the site-level most trees responded negatively to temperature and positively to precipitation, while at the tree-level black spruce exhibited heterogenous growth responses to climate that varied in both space (i.e., between sites) and time (i.e., seasonally and annually). There was a dominant response-type at each site, but there was also considerable variability in the proportion of trees exhibiting each response-type combination. Even in a climatically extreme setting like Alaska's boreal forest, tree responses to climate variability are spatially and temporally complex, as well as highly nonlinear.

Climate and Water Vulnerability of the US Electricity Grid Under High Penetrations of Renewable Energy

NASA Astrophysics Data System (ADS)

Macknick, J.; Miara, A.; O'Connell, M.; Vorosmarty, C. J.; Newmark, R. L.

2017-12-01

The US power sector is highly dependent upon water resources for reliable operations, primarily for thermoelectric cooling and hydropower technologies. Changes in the availability and temperature of water resources can limit electricity generation and cause outages at power plants, which substantially affect grid-level operational decisions. While the effects of water variability and climate changes on individual power plants are well documented, prior studies have not identified the significance of these impacts at the regional systems-level at which the grid operates, including whether there are risks for large-scale blackouts, brownouts, or increases in production costs. Adequately assessing electric grid system-level impacts requires detailed power sector modeling tools that can incorporate electric transmission infrastructure, capacity reserves, and other grid characteristics. Here, we present for the first time, a study of how climate and water variability affect operations of the power sector, considering different electricity sector configurations (low vs. high renewable) and environmental regulations. We use a case study of the US Eastern Interconnection, building off the Eastern Renewable Generation Integration Study (ERGIS) that explored operational challenges of high penetrations of renewable energy on the grid. We evaluate climate-water constraints on individual power plants, using the Thermoelectric Power and Thermal Pollution (TP2M) model coupled with the PLEXOS electricity production cost model, in the context of broader electricity grid operations. Using a five minute time step for future years, we analyze scenarios of 10% to 30% renewable energy penetration along with considerations of river temperature regulations to compare the cost, performance, and reliability tradeoffs of water-dependent thermoelectric generation and variable renewable energy technologies under climate stresses. This work provides novel insights into the resilience and reliability of different configurations of the US electric grid subject to changing climate conditions.

Choice of surrogate tissue influences neonatal EWAS findings.

PubMed

Lin, Xinyi; Teh, Ai Ling; Chen, Li; Lim, Ives Yubin; Tan, Pei Fang; MacIsaac, Julia L; Morin, Alexander M; Yap, Fabian; Tan, Kok Hian; Saw, Seang Mei; Lee, Yung Seng; Holbrook, Joanna D; Godfrey, Keith M; Meaney, Michael J; Kobor, Michael S; Chong, Yap Seng; Gluckman, Peter D; Karnani, Neerja

2017-12-05

Epigenomes are tissue specific and thus the choice of surrogate tissue can play a critical role in interpreting neonatal epigenome-wide association studies (EWAS) and in their extrapolation to target tissue. To develop a better understanding of the link between tissue specificity and neonatal EWAS, and the contributions of genotype and prenatal factors, we compared genome-wide DNA methylation of cord tissue and cord blood, two of the most accessible surrogate tissues at birth. In 295 neonates, DNA methylation was profiled using Infinium HumanMethylation450 beadchip arrays. Sites of inter-individual variability in DNA methylation were mapped and compared across the two surrogate tissues at birth, i.e., cord tissue and cord blood. To ascertain the similarity to target tissues, DNA methylation profiles of surrogate tissues were compared to 25 primary tissues/cell types mapped under the Epigenome Roadmap project. Tissue-specific influences of genotype on the variable CpGs were also analyzed. Finally, to interrogate the impact of the in utero environment, EWAS on 45 prenatal factors were performed and compared across the surrogate tissues. Neonatal EWAS results were tissue specific. In comparison to cord blood, cord tissue showed higher inter-individual variability in the epigenome, with a lower proportion of CpGs influenced by genotype. Both neonatal tissues were good surrogates for target tissues of mesodermal origin. They also showed distinct phenotypic associations, with effect sizes of the overlapping CpGs being in the same order of magnitude. The inter-relationship between genetics, prenatal factors and epigenetics is tissue specific, and requires careful consideration in designing and interpreting future neonatal EWAS. This birth cohort is a prospective observational study, designed to study the developmental origins of health and disease, and was retrospectively registered on 1 July 2010 under the identifier NCT01174875 .

Biologic variability of cardiac troponin I in healthy dogs and dogs with different stages of myxomatous mitral valve disease using standard and high-sensitivity immunoassays.

PubMed

Winter, Randolph L; Saunders, Ashley B; Gordon, Sonya G; Miller, Matthew W; Fosgate, Geoffrey T; Suchodolski, Jan S; Steiner, Jörg M

2017-06-01

Biologic variability (BV) is one aspect of interpreting changes in biomarker concentrations known to be clinically important in people with cardiac disease, but it has not been adequately addressed in dogs so far. The purpose of the study was to determine BV of cardiac troponin I (cTnI) in healthy dogs and dogs with 3 stages of myxomatous mitral valve disease (MMVD). Healthy dogs and dogs with 3 stages of MMVD were prospectively assigned to groups based on comprehensive clinical evaluation using current guidelines. Concentrations of cTnI were measured hourly, daily, and weekly using standard and high-sensitivity immunoassays. Within- (CV I ) and between-subject (CV G ) coefficients of variability, percent reference change value (RCV), and index of individuality (IoI) were calculated. All 10 healthy dogs and 76/112 (68%) of samples from 28 MMVD dogs had cTnI concentrations below the limit of detection (LOD) using a standard sensitivity immunoassay. Only 49/160 (31%) of healthy dog samples and no MMVD samples had cTnI below the high-sensitivity immunoassay LOD. Data analysis for the high-sensitivity immunoassay revealed CV I of 48.1%, CV G of 60.1%, RCV of 134.0%, and IoI of 0.804 in healthy dogs. In MMVD dogs, CV I was 39.6%, CV G was 80.7%, RCV was 110%, and IoI was 0.494. Of all MMVD dogs, those with Stage B2 had the lowest RCV of 91%. Biologic variability affects cTnI concentrations in healthy dogs and dogs with MMVD. Consideration of BV may be clinically relevant when monitoring individual changes in cTnI values, using high-sensitivity immunoassays. © 2017 American Society for Veterinary Clinical Pathology.

In vitro screening for population variability in toxicity of pesticide-containing mixtures

PubMed Central

Abdo, Nour; Wetmore, Barbara A.; Chappell, Grace A.; Shea, Damian; Wright, Fred A.; Rusyna, Ivan

2016-01-01

Population-based human in vitro models offer exceptional opportunities for evaluating the potential hazard and mode of action of chemicals, as well as variability in responses to toxic insults among individuals. This study was designed to test the hypothesis that comparative population genomics with efficient in vitro experimental design can be used for evaluation of the potential for hazard, mode of action, and the extent of population variability in responses to chemical mixtures. We selected 146 lymphoblast cell lines from 4 ancestrally and geographically diverse human populations based on the availability of genome sequence and basal RNA-seq data. Cells were exposed to two pesticide mixtures – an environmental surface water sample comprised primarily of organochlorine pesticides and a laboratory-prepared mixture of 36 currently used pesticides – in concentration response and evaluated for cytotoxicity. On average, the two mixtures exhibited a similar range of in vitro cytotoxicity and showed considerable inter-individual variability across screened cell lines. However, when in vitroto-in vivo extrapolation (IVIVE) coupled with reverse dosimetry was employed to convert the in vitro cytotoxic concentrations to oral equivalent doses and compared to the upper bound of predicted human exposure, we found that a nominally more cytotoxic chlorinated pesticide mixture is expected to have greater margin of safety (more than 5 orders of magnitude) as compared to the current use pesticide mixture (less than 2 orders of magnitude) due primarily to differences in exposure predictions. Multivariate genome-wide association mapping revealed an association between the toxicity of current use pesticide mixture and a polymorphism in rs1947825 in C17orf54. We conclude that a combination of in vitro human population-based cytotoxicity screening followed by dosimetric adjustment and comparative population genomics analyses enables quantitative evaluation of human health hazard from complex environmental mixtures. Additionally, such an approach yields testable hypotheses regarding potential toxicity mechanisms. PMID:26386728

Variables Related to Romanticism and Self-Esteem in Pregnant Teenagers.

ERIC Educational Resources Information Center

Medora, Nilufer P.; And Others

1993-01-01

Administered Dean Romanticism Scale and Bachman Self-Esteem Scale to 121 pregnant adolescents (ages 12-21). Found that two variables were significantly related to feelings of romanticism: adoption considerations and whether adolescent planned to have child with the baby's father. Two variables were significantly related to self-esteem: incidence…

Maternal, social and abiotic environmental effects on growth vary across life stages in a cooperative mammal

PubMed Central

English, Sinead; Bateman, Andrew W; Mares, Rafael; Ozgul, Arpat; Clutton-Brock, Tim H

2014-01-01

Resource availability plays a key role in driving variation in somatic growth and body condition, and the factors determining access to resources vary considerably across life stages. Parents and carers may exert important influences in early life, when individuals are nutritionally dependent, with abiotic environmental effects having stronger influences later in development as individuals forage independently. Most studies have measured specific factors influencing growth across development or have compared relative influences of different factors within specific life stages. Such studies may not capture whether early-life factors continue to have delayed effects at later stages, or whether social factors change when individuals become nutritionally independent and adults become competitors for, rather than providers of, food. Here, we examined variation in the influence of the abiotic, social and maternal environment on growth across life stages in a wild population of cooperatively breeding meerkats. Cooperatively breeding vertebrates are ideal for investigating environmental influences on growth. In addition to experiencing highly variable abiotic conditions, cooperative breeders are typified by heterogeneity both among breeders, with mothers varying in age and social status, and in the number of carers present. Recent rainfall had a consistently marked effect on growth across life stages, yet other seasonal terms only influenced growth during stages when individuals were growing fastest. Group size and maternal dominance status had positive effects on growth during the period of nutritional dependence on carers, but did not influence mass at emergence (at 1 month) or growth at independent stages (>4 months). Pups born to older mothers were lighter at 1 month of age and subsequently grew faster as subadults. Males grew faster than females during the juvenile and subadult stage only. Our findings demonstrate the complex ways in which the external environment influences development in a cooperative mammal. Individuals are most sensitive to social and maternal factors during the period of nutritional dependence on carers, whereas direct environmental effects are relatively more important later in development. Understanding the way in which environmental sensitivity varies across life stages is likely to be an important consideration in predicting trait responses to environmental change. PMID:24102215

Variable developmental delays and characteristic facial features-A novel 7p22.3p22.2 microdeletion syndrome?

PubMed

Yu, Andrea C; Zambrano, Regina M; Cristian, Ingrid; Price, Sue; Bernhard, Birgitta; Zucker, Marc; Venkateswaran, Sunita; McGowan-Jordan, Jean; Armour, Christine M

2017-06-01

Isolated 7p22.3p22.2 deletions are rarely described with only two reports in the literature. Most other reported cases either involve a much larger region of the 7p arm or have an additional copy number variation. Here, we report five patients with overlapping microdeletions at 7p22.3p22.2. The patients presented with variable developmental delays, exhibiting relative weaknesses in expressive language skills and relative strengths in gross, and fine motor skills. The most consistent facial features seen in these patients included a broad nasal root, a prominent forehead a prominent glabella and arched eyebrows. Additional variable features amongst the patients included microcephaly, metopic ridging or craniosynostosis, cleft palate, cardiac defects, and mild hypotonia. Although the patients' deletions varied in size, there was a 0.47 Mb region of overlap which contained 7 OMIM genes: EIP3B, CHST12, LFNG, BRAT1, TTYH3, AMZ1, and GNA12. We propose that monosomy of this region represents a novel microdeletion syndrome. We recommend that individuals with 7p22.3p22.2 deletions should receive a developmental assessment and a thorough cardiac exam, with consideration of an echocardiogram, as part of their initial evaluation. © 2017 Wiley Periodicals, Inc.

Laurentide Ice Sheet Meltwater Geochemistry During the MIS 3 Warm Phase from Single-Shell Trace Element and Isotope Measurements

NASA Astrophysics Data System (ADS)

Branson, O.; Vetter, L.; Fehrenbacher, J. S.; Spero, H. J.

2016-12-01

The geochemical variability between individual foraminifera within single core intervals records both palaeo-oecanographic conditions and ecology. Within the biological context of foraminiferal species, this population variability may be interpreted to provide unparalleled paleoenvironmental information. For example, coupled trace element and stable isotope analyses of single O. universa offer a powerful tool for reconstructing the δ18O of Laurentide Ice Sheet (LIS) meltwater, by calculating the intercept between temperature-corrected δ18O water and Ba/Ca salinity estimates (Vetter et al., in review). This offers valuable insights into the dynamics of ice sheet melting at the end of the last glacial maximum. Here we apply similar coupled single-shell laser ablation (LA-ICP-MS) and isotope ratio mass spectrometry (IRMS) techniques to explore the δ18O of Laurentide meltwater during H4 and bracketing intervals. The application of these methods to down-core samples requires the development of robust LA-ICP-MS data processing techniques to identify primary signals within Ba contaminated samples, and careful consideration of palaeo Ba/Ca-salinity relationships. Our analyses offer a significant advance in systematic LA-ICP-MS data processing methods, offer constraints on the variability of riverine Ba fluxes, and ultimately provide δ18O estimates of LIS meltwater during H4.

Non-Equilibrium Thermodynamics of Transcriptional Bursts

NASA Astrophysics Data System (ADS)

Hernández-Lemus, Enrique

Gene transcription or Gene Expression (GE) is the process which transforms the information encoded in DNA into a functional RNA message. It is known that GE can occur in bursts or pulses. Transcription is irregular, with strong periods of activity, interspersed by long periods of inactivity. If we consider the average behavior over millions of cells, this process appears to be continuous. But at the individual cell level, there is considerable variability, and for most genes, very little activity at any one time. Some have claimed that GE bursting can account for the high variability in gene expression occurring between cells in isogenic populations. This variability has a big impact on cell behavior and thus on phenotypic conditions and disease. In view of these facts, the development of a thermodynamic framework to study gene expression and transcriptional regulation to integrate the vast amount of molecular biophysical GE data is appealing. Application of such thermodynamic formalism is useful to observe various dissipative phenomena in GE regulatory dynamics. In this chapter we will examine at some detail the complex phenomena of transcriptional bursts (specially of a certain class of anomalous bursts) in the context of a non-equilibrium thermodynamics formalism and will make some initial comments on the relevance of some irreversible processes that may be connected to anomalous transcriptional bursts.

Within-Family Variability in Representations of Past Relationships With Parents

PubMed Central

Tucker, Corinna Jenkins; Fingerman, Karen; Savla, Jyoti

2009-01-01

Background We examined within-family variation in siblings’ memories of experiences with parents and their associations with current positive and negative affect. Methods Participants were 1,369 adults with at least 1 sibling, aged 26–74 years from 498 families in the MacArthur Study of Midlife in the United States (Mage = 47 years, 59% women, 94% White). Results There was considerable variability in recalled maternal and paternal treatment across the dimensions of affection (intraclass correlation coefficients [ICCs] 0.33 and 0.41, respectively), discipline (ICCs 0.39 and 0.43), and conflict (ICCs 0.24 and 0.26). In turn, recalled parental treatment, particularly affection, made unique contributions to current positive (ICC 0.12) and negative affect (ICC 0.08) over and above individual and familial level characteristics such as offspring demographic characteristics, extraversion and neuroticism, family structure, recalled early family environment, and parents' current status. Conclusions Results link adults' memories of experiences with their parents in childhood to their current well-being and highlight the importance of considering within-family models for family theory. PMID:19176488

The development of loneliness from mid- to late adolescence: trajectory classes, personality traits, and psychosocial functioning.

PubMed

Vanhalst, Janne; Goossens, Luc; Luyckx, Koen; Scholte, Ron H J; Engels, Rutger C M E

2013-12-01

Although loneliness is a common problem across late adolescence, its developmental course has not been investigated in depth in this period of life. The present study aims to fill this gap by means of a five-wave cohort-sequential longitudinal study spanning ages 15 to 20 (N = 389). Both variable-centered (i.e., latent growth curve modeling) and person-centered (i.e., latent class growth analysis) approaches were used. Variable-centered analyses showed that loneliness generally decreased over time. Person-centered analyses pointed to considerable inter-individual differences in the development of loneliness, and identified five trajectory classes (i.e., stable low, low increasing, moderate decreasing, high increasing, and chronically high). These five trajectory classes were differentially related to personality traits at age 15 (i.e., extraversion, agreeableness, and emotional stability) and psychosocial functioning at age 20 (i.e., depressive symptoms, self-esteem, anxiety, and perceived stress). These findings underscore the additional value of studying subgroups regarding the development of loneliness. Copyright © 2012 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

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

Burin, M. J.; Simmons, G. G.; Ceja, H. G.

The filamentary discharge seen within commercial plasma globes is commonly enjoyed yet not well understood. Here, we investigate the discharge properties of a plasma globe using a variable high voltage amplifier. We find that increasing voltage magnitude increases the number of filaments while leaving their individual structure basically unchanged, a result typical of dielectric barrier discharges. The frequency of the voltage also affects filament population but more significantly changes filament structure, with more diffuse filaments seen at lower frequencies. Voltage polarity is observed to be important, especially at lower frequencies, where for negative-gradient voltages the discharge is more diffuse, notmore » filamentary. At late stages of the discharge circular structures appear and expand on the glass boundaries. We find no trend of discharge speed with respect to voltage variables, though this may be due to manufacturer sample-to-sample variation. Each voltage cycle the discharge expands outward at ∼10–15 km/s, a speed significantly higher than the estimated electron drift yet considerably lower than that observed for most streamers. We discuss the physics of these observations and their relation to similar discharges that can be found within nature and industry.« less

Modelling and Optimising the Value of a Hybrid Solar-Wind System

NASA Astrophysics Data System (ADS)

Nair, Arjun; Murali, Kartik; Anbuudayasankar, S. P.; Arjunan, C. V.

2017-05-01

In this paper, a net present value (NPV) approach for a solar hybrid system has been presented. The system, in question aims at supporting an investor by assessing an investment in solar-wind hybrid system in a given area. The approach follow a combined process of modelling the system, with optimization of major investment-related variables to maximize the financial yield of the investment. The consideration of solar wind hybrid supply presents significant potential for cost reduction. The investment variables concern the location of solar wind plant, and its sizing. The system demand driven, meaning that its primary aim is to fully satisfy the energy demand of the customers. Therefore, the model is a practical tool in the hands of investor to assess and optimize in financial terms an investment aiming at covering real energy demand. Optimization is performed by taking various technical, logical constraints. The relation between the maximum power obtained between individual system and the hybrid system as a whole in par with the net present value of the system has been highlighted.

Risk factors for autism: translating genomic discoveries into diagnostics.

PubMed

Scherer, Stephen W; Dawson, Geraldine

2011-07-01

Autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in communication and reciprocal social interaction, and the presence of restricted and repetitive behaviors. The spectrum of autistic features is variable, with severity of symptoms ranging from mild to severe, sometimes with poor clinical outcomes. Twin and family studies indicate a strong genetic basis for ASD susceptibility. Recent progress in defining rare highly penetrant mutations and copy number variations as ASD risk factors has prompted early uptake of these research findings into clinical diagnostics, with microarrays becoming a 'standard of care' test for any ASD diagnostic work-up. The ever-changing landscape of the generation of genomic data coupled with the vast heterogeneity in cause and expression of ASDs (further influenced by issues of penetrance, variable expressivity, multigenic inheritance and ascertainment) creates complexity that demands careful consideration of how to apply this knowledge. Here, we discuss the scientific, ethical, policy and communication aspects of translating the new discoveries into clinical and diagnostic tools for promoting the well-being of individuals and families with ASDs.

Considerations in representing human individuals in social ecological models

USGS Publications Warehouse

Manfredo, Michael J.; Teel, Tara L.; Gavin, Michael C.; Fulton, David C.

2017-01-01

In this chapter we focus on how to integrate the human individual into social-ecological systems analysis, and how to improve research on individual thought and action regarding the environment by locating it within the broader social-ecological context. We discuss three key questions as considerations for future research: (1) is human thought conceptualized as a dynamic and adaptive process, (2) is the individual placed in a multi-level context (including within-person levels, person-group interactions, and institutional and structural factors), and (3) is human thought seen as mutually constructed with the social and natural environment. Increased emphasis on the individual will be essential if we are to understand agency, innovation, and adaptation in social-ecological systems.

Determination of macular hole size in relation to individual variabilities of fovea morphology.

PubMed

Shin, J Y; Chu, Y K; Hong, Y T; Kwon, O W; Byeon, S H

2015-08-01

To determine the preoperative anatomic factors in macular holes and their correlation to hole closure. Forty-six eyes with consecutive unilateral macular hole who had undergone surgery and followed up for at least 6 months were enrolled. Optical coherence tomography images and best-corrected visual acuity (BCVA) within 2 weeks prior to operation and 6 months after surgery were analyzed. The maximal hole dimension, foveal degeneration factors (inner nuclear layer cysts, outer segment (OS) shortening) and the widest foveolar floor size of the fellow eyes were measured. For overcoming preoperative individual variability of foveal morphology, an 'adjusted' hole size parameter (the ratio between the hole size and the fellow eye foveolar floor size) was used based on the fact that both eyes were morphologically symmetrical. Mean preoperative BCVA (logMAR) was 1.03±0.43 and the mean postoperative BCVA was 0.50±0.38 at 6 months. Preoperative BCVA is significantly associated with postoperative BCVA (P=0.0002). The average hole diameter was 448.9±196.8 μm and the average fellow eye foveolar floor size was 461.3±128.4 μm. There was a correlation between hole diameter and the size of the fellow eye foveolar floor (Pearson's coefficient=0.608, P<0.0001). The adjusted hole size parameter was 0.979±0.358 (0.761-2.336), which was a strong predictor for both anatomic (P=0.0281) and visual (P=0.0016) outcome. When determining the extent of preoperative hole size, we have to take into consideration the foveal morphologic variations among individuals. Hole size may be related to the original foveal shape, especially in relation to the centrifugal retraction of the foveal tissues.

Spatial and Temporal Dynamics of Pacific Oyster Hemolymph Microbiota across Multiple Scales

PubMed Central

Lokmer, Ana; Goedknegt, M. Anouk; Thieltges, David W.; Fiorentino, Dario; Kuenzel, Sven; Baines, John F.; Wegner, K. Mathias

2016-01-01

Unveiling the factors and processes that shape the dynamics of host associated microbial communities (microbiota) under natural conditions is an important part of understanding and predicting an organism's response to a changing environment. The microbiota is shaped by host (i.e., genetic) factors as well as by the biotic and abiotic environment. Studying natural variation of microbial community composition in multiple host genetic backgrounds across spatial as well as temporal scales represents a means to untangle this complex interplay. Here, we combined a spatially-stratified with a longitudinal sampling scheme within differentiated host genetic backgrounds by reciprocally transplanting Pacific oysters between two sites in the Wadden Sea (Sylt and Texel). To further differentiate contingent site from host genetic effects, we repeatedly sampled the same individuals over a summer season to examine structure, diversity and dynamics of individual hemolymph microbiota following experimental removal of resident microbiota by antibiotic treatment. While a large proportion of microbiome variation could be attributed to immediate environmental conditions, we observed persistent effects of antibiotic treatment and translocation suggesting that hemolymph microbial community dynamics is subject to within-microbiome interactions and host population specific factors. In addition, the analysis of spatial variation revealed that the within-site microenvironmental heterogeneity resulted in high small-scale variability, as opposed to large-scale (between-site) stability. Similarly, considerable within-individual temporal variability was in contrast with the overall temporal stability at the site level. Overall, our longitudinal, spatially-stratified sampling design revealed that variation in hemolymph microbiota is strongly influenced by site and immediate environmental conditions, whereas internal microbiome dynamics and oyster-related factors add to their long-term stability. The combination of small and large scale resolution of spatial and temporal observations therefore represents a crucial but underused tool to study host-associated microbiome dynamics. PMID:27630625

Therapygenetics: Using genetic markers to predict response to psychological treatment for mood and anxiety disorders

PubMed Central

2013-01-01

Considerable variation is evident in response to psychological therapies for mood and anxiety disorders. Genetic factors alongside environmental variables and gene-environment interactions are implicated in the etiology of these disorders and it is plausible that these same factors may also be important in predicting individual differences in response to psychological treatment. In this article, we review the evidence that genetic variation influences psychological treatment outcomes with a primary focus on mood and anxiety disorders. Unlike most past work, which has considered prediction of response to pharmacotherapy, this article reviews recent work in the field of therapygenetics, namely the role of genes in predicting psychological treatment response. As this is a field in its infancy, methodological recommendations are made and opportunities for future research are identified. PMID:23388219

[Interspecies differences of noopept pharmacokinetics].

PubMed

Boĭko, S S; Korotkov, S A; Zherdev, V P; Gudasheva, T A; Ostrovskaia, R U; Voronina, T A

2004-01-01

Significant interspecific differences in the pharmacokinetics of noopept are manifested by a decrease in the drug elimination rate on the passage from rats to rabbits and humans. Very intensive metabolism of noopept was observed upon intravenous administration in rats. In these animals, presystemic elimination mechanisms lead to the formation of a specific metabolite representing a product of drug biotransformation hydroxylated at the phenyl ring. In rabbits, unchanged noopept circulates in the blood for a longer time upon both intravenous and peroral introduction, biotransformation proceeds at a much slower rate, and no metabolites analogous to that found in rats are detected. The noopept pharmacokinetics in humans differs from that in animals by still slower elimination and considerable individual variability. No drug metabolites are found in the human blood plasma, probably because of a relatively small dose and low concentration.

Making Inferences: Comprehension of Physical Causality, Intentionality, and Emotions in Discourse by High-Functioning Older Children, Adolescents, and Adults with Autism.

PubMed

Bodner, Kimberly E; Engelhardt, Christopher R; Minshew, Nancy J; Williams, Diane L

2015-09-01

Studies investigating inferential reasoning in autism spectrum disorder (ASD) have focused on the ability to make socially-related inferences or inferences more generally. Important variables for intervention planning such as whether inferences depend on physical experiences or the nature of social information have received less consideration. A measure of bridging inferences of physical causation, mental states, and emotional states was administered to older children, adolescents, and adults with and without ASD. The ASD group had more difficulty making inferences, particularly related to emotional understanding. Results suggest that individuals with ASD may not have the stored experiential knowledge that specific inferences depend upon or have difficulties accessing relevant experiences due to linguistic limitations. Further research is needed to tease these elements apart.

Popularity Trajectories and Substance Use in early Adolescence1

PubMed Central

Moody, James; Brynildsen, Wendy D.; Osgood, D. Wayne; Feinberg, Mark E.; Gest, Scott

2010-01-01

This paper introduces new longitudinal network data from the “Promoting School-Community-University Partnerships to Enhance Resilience” or “PROSPER” peers project. In 28 communities, grade-level sociometric friendship nominations were collected from two cohorts of middle school students as they moved from 6th, to 9th grade. As an illustration and description of these longitudinal network data, this paper describes the school popularity structure, changes in popularity position, and suggests linkages between popularity trajectory and substance use. In the cross-section, we find that the network is consistent with a hierarchical social organization, but exhibits considerable relational change in both particular friends and position at the individual level. We find that both the base level of popularity and the variability of popularity trajectories effect substance use. PMID:21765588

Mechanical ventilation strategies.

PubMed

Keszler, Martin

2017-08-01

Although only a small proportion of full term and late preterm infants require invasive respiratory support, they are not immune from ventilator-associated lung injury. The process of lung damage from mechanical ventilation is multifactorial and cannot be linked to any single variable. Atelectrauma and volutrauma have been identified as the most important and potentially preventable elements of lung injury. Respiratory support strategies for full term and late preterm infants have not been as thoroughly studied as those for preterm infants; consequently, a strong evidence base on which to make recommendations is lacking. The choice of modalities of support and ventilation strategies should be guided by the specific underlying pathophysiologic considerations and the ventilatory approach must be individualized for each patient based on the predominant pathophysiology at the time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Medical treatment of acquired nystagmus.

PubMed

Ehrhardt, David; Eggenberger, Eric

2012-11-01

This article synthesises recent findings and addresses relevant anatomy, pathophysiologic considerations, and current treatment options for common forms of acquired nystagmus including vestibular and gaze holding dysfunction. Some forms of nystagmus have relatively specific treatments, such as baclofen for periodic alternating nystagmus, and repositioning for benign paroxysmal positional vertigo. Recent studies have brought changes to many of the treatments of nystagmus variants. Additionally, other recent advances in nystagmus treatment, like the usage of 4-aminopyridine, have added potent medications to the physician's armamentarium. Nystagmus is a commonly encountered entity in clinical practice. However, evidence supported treatments are scarce. Medical treatment of nystagmus is difficult, with often limited and variable response to pharmacologic therapies. This mandates a continued re-evaluation of patients and creation of an individualized approach to this common clinical problem.

Too Materialistic to Get Married and Have Children?

PubMed Central

Li, Norman P.; Lim, Amy J. Y.; Tsai, Ming-Hong; O, Jiaqing

2015-01-01

We developed new materials to induce a luxury mindset and activate materialistic values, and examined materialism’s relationship to attitudes toward marriage and having children in Singapore. Path analyses indicated that materialistic values led to more negative attitudes toward marriage, which led to more negative attitudes toward children, which in turn led to a decreased number of children desired. Results across two studies highlight, at the individual level, the tradeoff between materialistic values and attitudes toward marriage and procreation and suggest that a consideration of psychological variables such as materialistic values may allow for a better understanding of larger-scale socioeconomic issues including low fertility rates among developed countries. We discuss implications and describe how psychological factors relating to low fertility fit within evolutionary mismatch and life history theory frameworks. PMID:25955502

Comparison of the nuclear organiser region activity in four taxa of the family Canidae.

PubMed

Pieńkowska, A; Zagalska, M

2001-01-01

Four species of the family Canidae were cytogenetically studied. The activity of NORs was detected with the use of silver staining. The number of NORs was characteristic for a given karyotype. For the dog found on autosomes 7, 17, 20 and on sex chromosome (Y), for the racoon dog on autosomes 1, 4, 13 and on sex chromosome (Y), for the silver fox only on autosomes 8, 9, 13 and for the blue fox on autosomes 13, 15, 17, 18, 20 and 22. The results demonstrate that NOR activity is similar in all the analysed species of the Canidae. Simultaneously, NOR activity for a medium-sized chromosome pair is distinctly higher than for two other autosome pairs (the longest and the smallest pair). Considerable variability was observed within individuals.

Noninvasive evaluation system of fractured bone based on speckle interferometry

NASA Astrophysics Data System (ADS)

Yamanada, Shinya; Murata, Shigeru; Tanaka, Yohsuke

2010-11-01

This paper presents a noninvasive evaluation system of fractured bone based on speckle interferometry using a modified evaluation index for higher performance, and the experiments are carried out to examine the feasibility in evaluating bone fracture healing and the influence of some system parameters on the performance. From experimental results, it is shown that the presence of fractured part of bone and the state of bone fracture healing are successfully estimated by observing fine speckle fringes on the object surface. The proposed evaluation index also can successfully express the difference between the cases with cut and without it. Since most system parameters are found not to affect the performance of the present technique, the present technique is expected to be applied to various patients that have considerable individual variability.

A practical measure of workplace resilience: developing the resilience at work scale.

PubMed

Winwood, Peter C; Colon, Rochelle; McEwen, Kath

2013-10-01

To develop an effective measure of resilience at work for use in individual work-related performance and emotional distress contexts. Two separate cross-sectional studies investigated: (1) exploratory factor analysis of 45 items putatively underpinning workplace resilience among 397 participants and (2) confirmatory factor analysis of resilience measure derived from Study 1 demonstrating a credible model of interaction, with performance outcome variables among 194 participants. A 20-item scale explaining 67% of variance, measuring seven aspects of workplace resilience, which are teachable and capable of conscious development, was achieved. A credible model of relationships with work engagement, sleep, stress recovery, and physical health was demonstrated in the expected directions. The new scale shows considerable promise as a reliable instrument for use in the area of employee support and development.

Too materialistic to get married and have children?

PubMed

Li, Norman P; Lim, Amy J Y; Tsai, Ming-Hong; O, Jiaqing

2015-01-01

We developed new materials to induce a luxury mindset and activate materialistic values, and examined materialism's relationship to attitudes toward marriage and having children in Singapore. Path analyses indicated that materialistic values led to more negative attitudes toward marriage, which led to more negative attitudes toward children, which in turn led to a decreased number of children desired. Results across two studies highlight, at the individual level, the tradeoff between materialistic values and attitudes toward marriage and procreation and suggest that a consideration of psychological variables such as materialistic values may allow for a better understanding of larger-scale socioeconomic issues including low fertility rates among developed countries. We discuss implications and describe how psychological factors relating to low fertility fit within evolutionary mismatch and life history theory frameworks.

Impacts of correcting the inter-variable correlation of climate model outputs on hydrological modeling

NASA Astrophysics Data System (ADS)

Chen, Jie; Li, Chao; Brissette, François P.; Chen, Hua; Wang, Mingna; Essou, Gilles R. C.

2018-05-01

Bias correction is usually implemented prior to using climate model outputs for impact studies. However, bias correction methods that are commonly used treat climate variables independently and often ignore inter-variable dependencies. The effects of ignoring such dependencies on impact studies need to be investigated. This study aims to assess the impacts of correcting the inter-variable correlation of climate model outputs on hydrological modeling. To this end, a joint bias correction (JBC) method which corrects the joint distribution of two variables as a whole is compared with an independent bias correction (IBC) method; this is considered in terms of correcting simulations of precipitation and temperature from 26 climate models for hydrological modeling over 12 watersheds located in various climate regimes. The results show that the simulated precipitation and temperature are considerably biased not only in the individual distributions, but also in their correlations, which in turn result in biased hydrological simulations. In addition to reducing the biases of the individual characteristics of precipitation and temperature, the JBC method can also reduce the bias in precipitation-temperature (P-T) correlations. In terms of hydrological modeling, the JBC method performs significantly better than the IBC method for 11 out of the 12 watersheds over the calibration period. For the validation period, the advantages of the JBC method are greatly reduced as the performance becomes dependent on the watershed, GCM and hydrological metric considered. For arid/tropical and snowfall-rainfall-mixed watersheds, JBC performs better than IBC. For snowfall- or rainfall-dominated watersheds, however, the two methods behave similarly, with IBC performing somewhat better than JBC. Overall, the results emphasize the advantages of correcting the P-T correlation when using climate model-simulated precipitation and temperature to assess the impact of climate change on watershed hydrology. However, a thorough validation and a comparison with other methods are recommended before using the JBC method, since it may perform worse than the IBC method for some cases due to bias nonstationarity of climate model outputs.

Variability in individual activity bursts improves ant foraging success.

PubMed

Campos, Daniel; Bartumeus, Frederic; Méndez, Vicenç; Andrade, José S; Espadaler, Xavier

2016-12-01

Using experimental and computational methods, we study the role of behavioural variability in activity bursts (or temporal activity patterns) for individual and collective regulation of foraging in A. senilis ants. First, foraging experiments were carried out under special conditions (low densities of ants and food and absence of external cues or stimuli) where individual-based strategies are most prevalent. By using marked individuals and recording all foraging trajectories, we were then able to precisely quantify behavioural variability among individuals. Our main conclusions are that (i) variability of ant trajectories (turning angles, speed, etc.) is low compared with variability of temporal activity profiles, and (ii) this variability seems to be driven by plasticity of individual behaviour through time, rather than the presence of fixed behavioural stereotypes or specialists within the group. The statistical measures obtained from these experimental foraging patterns are then used to build a general agent-based model (ABM) which includes the most relevant properties of ant foraging under natural conditions, including recruitment through pheromone communication. Using the ABM, we are able to provide computational evidence that the characteristics of individual variability observed in our experiments can provide a functional advantage (in terms of foraging success) to the group; thus, we propose the biological basis underpinning our observations. Altogether, our study reveals the potential utility of experiments under simplified (laboratory) conditions for understanding information-gathering in biological systems. © 2016 The Author(s).

267 Spanish Exomes Reveal Population-Specific Differences in Disease-Related Genetic Variation.

PubMed

Dopazo, Joaquín; Amadoz, Alicia; Bleda, Marta; Garcia-Alonso, Luz; Alemán, Alejandro; García-García, Francisco; Rodriguez, Juan A; Daub, Josephine T; Muntané, Gerard; Rueda, Antonio; Vela-Boza, Alicia; López-Domingo, Francisco J; Florido, Javier P; Arce, Pablo; Ruiz-Ferrer, Macarena; Méndez-Vidal, Cristina; Arnold, Todd E; Spleiss, Olivia; Alvarez-Tejado, Miguel; Navarro, Arcadi; Bhattacharya, Shomi S; Borrego, Salud; Santoyo-López, Javier; Antiñolo, Guillermo

2016-05-01

Recent results from large-scale genomic projects suggest that allele frequencies, which are highly relevant for medical purposes, differ considerably across different populations. The need for a detailed catalog of local variability motivated the whole-exome sequencing of 267 unrelated individuals, representative of the healthy Spanish population. Like in other studies, a considerable number of rare variants were found (almost one-third of the described variants). There were also relevant differences in allelic frequencies in polymorphic variants, including ∼10,000 polymorphisms private to the Spanish population. The allelic frequencies of variants conferring susceptibility to complex diseases (including cancer, schizophrenia, Alzheimer disease, type 2 diabetes, and other pathologies) were overall similar to those of other populations. However, the trend is the opposite for variants linked to Mendelian and rare diseases (including several retinal degenerative dystrophies and cardiomyopathies) that show marked frequency differences between populations. Interestingly, a correspondence between differences in allelic frequencies and disease prevalence was found, highlighting the relevance of frequency differences in disease risk. These differences are also observed in variants that disrupt known drug binding sites, suggesting an important role for local variability in population-specific drug resistances or adverse effects. We have made the Spanish population variant server web page that contains population frequency information for the complete list of 170,888 variant positions we found publicly available (http://spv.babelomics.org/), We show that it if fundamental to determine population-specific variant frequencies to distinguish real disease associations from population-specific polymorphisms. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Screening variability and change of soil moisture under wide-ranging climate conditions: Snow dynamics effects.

PubMed

Verrot, Lucile; Destouni, Georgia

2015-01-01

Soil moisture influences and is influenced by water, climate, and ecosystem conditions, affecting associated ecosystem services in the landscape. This paper couples snow storage-melting dynamics with an analytical modeling approach to screening basin-scale, long-term soil moisture variability and change in a changing climate. This coupling enables assessment of both spatial differences and temporal changes across a wide range of hydro-climatic conditions. Model application is exemplified for two major Swedish hydrological basins, Norrström and Piteälven. These are located along a steep temperature gradient and have experienced different hydro-climatic changes over the time period of study, 1950-2009. Spatially, average intra-annual variability of soil moisture differs considerably between the basins due to their temperature-related differences in snow dynamics. With regard to temporal change, the long-term average state and intra-annual variability of soil moisture have not changed much, while inter-annual variability has changed considerably in response to hydro-climatic changes experienced so far in each basin.

Variability of gastrointestinal transit in healthy women and men.

PubMed Central

Degen, L P; Phillips, S F

1996-01-01

BACKGROUND AND AIMS: Measurements of gastrointestinal transit are made in clinical and research gastroenterology, yet their intrinsic variability is not well characterised. In particular, an influence of hormones on transit has been proposed as the basis for gastrointestinal symptoms that vary with the menstrual cycle. Our aims were to quantify individual differences in transit during the menstrual cycle in healthy women and to compare these with the intrinsic variability in healthy men. METHODS: On two occasions, whole gut transit was assessed scintigraphically and colonic transit quantified by radio-opaque markers. Thirty two healthy volunteers (12 women, 20 men) were studied, women during the follicular and luteal phases, men twice within a similar four week period. Diets and exercise were standardised prior to and during both studies. RESULTS: Colonic transit was significantly faster in men, and postlag gastric emptying was also more rapid; other indices of regional transit were not different between the sexes. Total colonic transit time was equally well reflected by the scintigraphic and radio-opaque marker methods. Important intraindividual differences were noted in both sexes. The variances in our samples predicted an 80% chance of detecting (with 95% confidence) a mean effect of menstrual hormones on transit that was in the same range as the intrinsic variation in men. CONCLUSIONS: Colonic transit was faster in men than in women. Although group means in the two studies were almost identical, single assessments of transit in subjects sometimes exhibited considerable variability, implying broad biological variations. Given this intrinsic variability, the influence of menstrual hormones on gastrointestinal transit must be small and of doubtful clinical significance. PMID:8977347

Variability in platelet dense granule adenosine triphosphate release findings amongst patients tested multiple times as part of an assessment for a bleeding disorder.

PubMed

Badin, M S; Graf, L; Iyer, J K; Moffat, K A; Seecharan, J L; Hayward, C P M

2016-12-01

Lumi-aggregometry quantification of platelet dense granule adenosine triphosphate (ATP) release is commonly used for diagnosing platelet function disorders. As the test findings show considerable variability for healthy controls, we postulated that patient findings might also be variable and investigated patients who were assessed for dense granule ATP release defects more than once. Analyses were performed on prospectively collected data for first and second tests for subjects tested for dense granule ATP release defects more than once by the Hamilton Regional Laboratory Program (HRLMP) between January 2007 and June 2013 (cohort I). Similar analyses were performed for subjects who were recruited to a platelet disorder study (cohort II) and were assessed for ATP release defects more than once before October 2015. A total of 150 unique subjects had multiple ATP release tests. Results with individual agonists were variable for many subjects. While normal findings with all tested agonists were often confirmed by the second test (cohort I: 83%; cohort II: 100%), impaired release with multiple agonists was confirmed in only some subjects (cohort I: 34%; cohort II: 54%). Inconsistent findings were common (cohort I: 36%; cohort II: 39%). ISTH bleeding scores showed no relationship to the test findings. The finding of impaired ATP release with 2 or more agonists on both tests was not associated with an increased likelihood of a definite bleeding disorder. The variability in platelet dense granule ATP release findings amongst patients assessed for diagnostic purposes suggests that the test has limited value for diagnosing platelet disorders. © 2016 John Wiley & Sons Ltd.

The Potential for Differential Findings among Invariance Testing Strategies for Multisample Measured Variable Path Models

ERIC Educational Resources Information Center

Mann, Heather M.; Rutstein, Daisy W.; Hancock, Gregory R.

2009-01-01

Multisample measured variable path analysis is used to test whether causal/structural relations among measured variables differ across populations. Several invariance testing approaches are available for assessing cross-group equality of such relations, but the associated test statistics may vary considerably across methods. This study is a…

Capturing the dynamics of response variability in the brain in ADHD.

PubMed

van Belle, Janna; van Raalten, Tamar; Bos, Dienke J; Zandbelt, Bram B; Oranje, Bob; Durston, Sarah

2015-01-01

ADHD is characterized by increased intra-individual variability in response times during the performance of cognitive tasks. However, little is known about developmental changes in intra-individual variability, and how these changes relate to cognitive performance. Twenty subjects with ADHD aged 7-24 years and 20 age-matched, typically developing controls participated in an fMRI-scan while they performed a go-no-go task. We fit an ex-Gaussian distribution on the response distribution to objectively separate extremely slow responses, related to lapses of attention, from variability on fast responses. We assessed developmental changes in these intra-individual variability measures, and investigated their relation to no-go performance. Results show that the ex-Gaussian measures were better predictors of no-go performance than traditional measures of reaction time. Furthermore, we found between-group differences in the change in ex-Gaussian parameters with age, and their relation to task performance: subjects with ADHD showed age-related decreases in their variability on fast responses (sigma), but not in lapses of attention (tau), whereas control subjects showed a decrease in both measures of variability. For control subjects, but not subjects with ADHD, this age-related reduction in variability was predictive of task performance. This group difference was reflected in neural activation: for typically developing subjects, the age-related decrease in intra-individual variability on fast responses (sigma) predicted activity in the dorsal anterior cingulate gyrus (dACG), whereas for subjects with ADHD, activity in this region was related to improved no-go performance with age, but not to intra-individual variability. These data show that using more sophisticated measures of intra-individual variability allows the capturing of the dynamics of task performance and associated neural changes not permitted by more traditional measures.

Capturing the dynamics of response variability in the brain in ADHD

PubMed Central

van Belle, Janna; van Raalten, Tamar; Bos, Dienke J.; Zandbelt, Bram B.; Oranje, Bob; Durston, Sarah

2014-01-01

ADHD is characterized by increased intra-individual variability in response times during the performance of cognitive tasks. However, little is known about developmental changes in intra-individual variability, and how these changes relate to cognitive performance. Twenty subjects with ADHD aged 7–24 years and 20 age-matched, typically developing controls participated in an fMRI-scan while they performed a go-no-go task. We fit an ex-Gaussian distribution on the response distribution to objectively separate extremely slow responses, related to lapses of attention, from variability on fast responses. We assessed developmental changes in these intra-individual variability measures, and investigated their relation to no-go performance. Results show that the ex-Gaussian measures were better predictors of no-go performance than traditional measures of reaction time. Furthermore, we found between-group differences in the change in ex-Gaussian parameters with age, and their relation to task performance: subjects with ADHD showed age-related decreases in their variability on fast responses (sigma), but not in lapses of attention (tau), whereas control subjects showed a decrease in both measures of variability. For control subjects, but not subjects with ADHD, this age-related reduction in variability was predictive of task performance. This group difference was reflected in neural activation: for typically developing subjects, the age-related decrease in intra-individual variability on fast responses (sigma) predicted activity in the dorsal anterior cingulate gyrus (dACG), whereas for subjects with ADHD, activity in this region was related to improved no-go performance with age, but not to intra-individual variability. These data show that using more sophisticated measures of intra-individual variability allows the capturing of the dynamics of task performance and associated neural changes not permitted by more traditional measures. PMID:25610775

Urban bound migration and rural investment: the case of Mexico.

PubMed

Silvers, A L; Crosson, P

1983-02-01

The authors investigate an agriculturally based policy for improving rural incomes and for retarding the rural-urban migration flow. The production of agricultural goods is characterized by a production function in which output increases with increases in agricultural labor inputs, capital, public infrastructure, land, and technology. Differences among regions in agricultural technology will reflect regional differences in education, the institutionalized form of productive organization, and differences in access to technological information channeled through more technically advanced cities. To pick up the effect of out-migration changes in state agricultural labor supply and upon agricultural output, the state's agricultural out-migration rate is included together with the agricultural labor force. The gross migrant flow between 2 locations is hypothesized to depend upon a set of variables influencing the individual's perception of the economic rate of return to be gained by moving, a set of variables reflecting the individual's propensity to relocate, the labor displacement effects of investments, and the at risk population at 1 location available to migrate. It is also taken into account that individuals differ in their response to information about origin and destination wage differentials and that individuals may or may not perceive a new ecnomic gain from migration but may base the decision on other considerations. Results of a statistical analysis using data from the Mexican census of population for 1960 and 1970 are: 1) size of the rural labor force was negatively associated with agricultural wages, contrary to expectations; 2) small farmers have benefited from the expansion of irrigation in Mexico; and 3) higher urban wages attract migration, and higher growth rate of agricultural income retards rural-urban migration. With respect to the 1950-60 decade both agricultural income and rural out-migration impacts could have been substantial but both the impact on local urban growth and on the rate of in-migration to the primate city would have been slight.

Considerations for Assessing Maximum Critical Temperatures in Small Ectothermic Animals: Insights from Leaf-Cutting Ants

PubMed Central

Ribeiro, Pedro Leite; Camacho, Agustín; Navas, Carlos Arturo

2012-01-01

The thermal limits of individual animals were originally proposed as a link between animal physiology and thermal ecology. Although this link is valid in theory, the evaluation of physiological tolerances involves some problems that are the focus of this study. One rationale was that heating rates shall influence upper critical limits, so that ecological thermal limits need to consider experimental heating rates. In addition, if thermal limits are not surpassed in experiments, subsequent tests of the same individual should yield similar results or produce evidence of hardening. Finally, several non-controlled variables such as time under experimental conditions and procedures may affect results. To analyze these issues we conducted an integrative study of upper critical temperatures in a single species, the ant Atta sexdens rubropiosa, an animal model providing large numbers of individuals of diverse sizes but similar genetic makeup. Our specific aims were to test the 1) influence of heating rates in the experimental evaluation of upper critical temperature, 2) assumptions of absence of physical damage and reproducibility, and 3) sources of variance often overlooked in the thermal-limits literature; and 4) to introduce some experimental approaches that may help researchers to separate physiological and methodological issues. The upper thermal limits were influenced by both heating rates and body mass. In the latter case, the effect was physiological rather than methodological. The critical temperature decreased during subsequent tests performed on the same individual ants, even one week after the initial test. Accordingly, upper thermal limits may have been overestimated by our (and typical) protocols. Heating rates, body mass, procedures independent of temperature and other variables may affect the estimation of upper critical temperatures. Therefore, based on our data, we offer suggestions to enhance the quality of measurements, and offer recommendations to authors aiming to compile and analyze databases from the literature. PMID:22384147

Multi-centre diagnostic classification of individual structural neuroimaging scans from patients with major depressive disorder.

PubMed

Mwangi, Benson; Ebmeier, Klaus P; Matthews, Keith; Steele, J Douglas

2012-05-01

Quantitative abnormalities of brain structure in patients with major depressive disorder have been reported at a group level for decades. However, these structural differences appear subtle in comparison with conventional radiologically defined abnormalities, with considerable inter-subject variability. Consequently, it has not been possible to readily identify scans from patients with major depressive disorder at an individual level. Recently, machine learning techniques such as relevance vector machines and support vector machines have been applied to predictive classification of individual scans with variable success. Here we describe a novel hybrid method, which combines machine learning with feature selection and characterization, with the latter aimed at maximizing the accuracy of machine learning prediction. The method was tested using a multi-centre dataset of T(1)-weighted 'structural' scans. A total of 62 patients with major depressive disorder and matched controls were recruited from referred secondary care clinical populations in Aberdeen and Edinburgh, UK. The generalization ability and predictive accuracy of the classifiers was tested using data left out of the training process. High prediction accuracy was achieved (~90%). While feature selection was important for maximizing high predictive accuracy with machine learning, feature characterization contributed only a modest improvement to relevance vector machine-based prediction (~5%). Notably, while the only information provided for training the classifiers was T(1)-weighted scans plus a categorical label (major depressive disorder versus controls), both relevance vector machine and support vector machine 'weighting factors' (used for making predictions) correlated strongly with subjective ratings of illness severity. These results indicate that machine learning techniques have the potential to inform clinical practice and research, as they can make accurate predictions about brain scan data from individual subjects. Furthermore, machine learning weighting factors may reflect an objective biomarker of major depressive disorder illness severity, based on abnormalities of brain structure.

TECHNOLOGICAL CONSIDERATIONS FOR PLANNING THE GLOBAL CARBON FUTURE

EPA Science Inventory

The atmospheric level of carbon dioxide (CO2) is the dominant variable in the anthropogenic influence of future global climate change. Thus, it is critical to understand the long-term factors affecting its level, especially the longer-range technological considerations. Most rece...

Conflicting and complementary ethics of animal welfare considerations in reintroductions.

PubMed

Harrington, Lauren A; Moehrenschlager, Axel; Gelling, Merryl; Atkinson, Rob P D; Hughes, Joelene; Macdonald, David W

2013-06-01

Despite differences in focus, goals, and strategies between conservation biology and animal welfare, both are inextricably linked in many ways, and greater consideration of animal welfare, although important in its own right, also has considerable potential to contribute to conservation success. Nevertheless, animal welfare and animal ethics are not always considered explicitly within conservation practice. We systematically reviewed the recent scientific peer-reviewed and online gray literature on reintroductions of captive-bred and wild-caught animals (mammals, birds, amphibians, and reptiles) to quantify the occurrence of animal welfare issues. We considered monitoring that could be indicative of the animal's welfare status and supportive management actions that could improve animal welfare (regardless of whether the aim was explicitly animal-welfare orientated). Potential welfare issues (of variable nature and extent) were recorded in 67% of 199 projects reviewed; the most common were mortality >50%, dispersal or loss of animals, disease, and human conflict. Most (>70%) projects monitored survival, 18% assessed body condition, and 2% monitored stress levels. Animal welfare, explicitly, was referred to in 6% of projects. Supportive actions, most commonly use of on-site prerelease pens and provision of supplemental food or water, were implemented in 79% of projects, although the extent and duration of support varied. Practitioners can address animal-welfare issues in reintroductions by considering the potential implications for individual animals at all stages of the release process using the decision tree presented. We urge practitioners to report potential animal-welfare issues, describe mitigation actions, and evaluate their efficacy to facilitate transparent evaluation of common moral dilemmas and to advance communal strategies for dealing with them. Currently, comparative mortality rates, health risks, postrelease stress, effectiveness of supportive measures, and behavior of individuals warrant further research to improve animal welfare in reintroductions and to increase success of such projects. © 2013 Society for Conservation Biology.

Individual animal variability in ruminal bacterial communities and ruminal acidosis in primiparous Holstein cows during the periparturient period

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to investigate variability among individual cows for their susceptibility to ruminal acidosis (RA) pre- and postpartum, and determine whether this variability was related to differences in their ruminal bacterial community composition (BCC). Variability in susceptibilit...

Romanticism and self-esteem among teen mothers.

PubMed

Medora, N P; von der Hellen, C

1997-01-01

This study examined teen mothers' romanticism and self-esteem. The Dean Romanticism Scale and the Bachman Self-esteem Scale were administered to 94 mothers between the ages of 13 and 18 in Southern California. The study also investigated the relationship between the dependent variables--romanticism and self-esteem--and ten independent variables--age, age of mother when first child was born, incidence of sexual abuse, incidence of abortion, current sexual activity, adoption considerations, current use of birth control, whether paternity was denied by the baby's father, whether the mother's parents were living together, and the quality of the relationship between the mother's parents. Results indicated that five variables were significantly related to romanticism--whether the teenager had a previous abortion, adoption considerations, current sexual activity, whether the parents were living together, and the quality of the relationship between the parents. Two variables were significantly related to self-esteem--age and current use of birth control.

Who punishes? Personality traits predict individual variation in punitive sentiment.

PubMed

Roberts, S Craig; Vakirtzis, Antonios; Kristjánsdóttir, Lilja; Havlíček, Jan

2013-02-18

Cross-culturally, participants in public goods games reward participants and punish defectors to a degree beyond that warranted by rational, profit-maximizing considerations. Costly punishment, where individuals impose costs on defectors at a cost to themselves, is thought to promote the maintenance of cooperation. However, despite substantial variation in the extent to which people punish, little is known about why some individuals, and not others, choose to pay these costs. Here, we test whether personality traits might contribute to variation in helping and punishment behavior. We first replicate a previous study using public goods scenarios to investigate effects of sex, relatedness and likelihood of future interaction on willingness to help a group member or to punish a transgressor. As in the previous study, we find that individuals are more willing to help related than unrelated needy others and that women are more likely to express desire to help than men. Desire to help was higher if the probability of future interaction is high, at least among women. In contrast, among these variables, only participant sex predicted some measures of punitive sentiment. Extending the replication, we found that punitive sentiment, but not willingness to help, was predicted by personality traits. Most notably, participants scoring lower on Agreeableness expressed more anger towards and greater desire to punish a transgressor, and were more willing to engage in costly punishment, at least in our scenario. Our results suggest that some personality traits may contribute to underpinning individual variation in social enforcement of cooperation.

Are there individual and sibling differences in appraisals of interparental conflict?

PubMed

Lucas-Thompson, Rachel G; George, Melissa W

2017-10-01

Despite decades of empirical literature documenting the harmful effects of frequent, intense, violent, and unresolved interparental conflict on children's adjustment, there is considerable variability in the extent to which marital conflict contributes to the development of children's emotional and behavioral problems. Past research has documented links between properties of interparental conflict itself (e.g., intensity, frequency), children's appraisals of conflict, and children's outcomes, yet less is known about the role of individual and family characteristics in predicting children's conflict appraisals. Sibling studies may be especially helpful in understanding these individual differences yet are notably lacking in marital conflict research. The current study examines individual- and family-characteristic predictors of adolescents' appraisals of conflict in a study of 153 adolescents as well as sibling similarities in conflict appraisals in a subsample of 50 pairs of siblings. Controlling for parent reports of the frequency, intensity, and resolution of interparental conflict, parent-child relationship quality and stressful life events predicted conflict appraisals. In addition, there was nonindependence of sibling appraisals of conflict properties, but self-blame and threat appraisals appeared independent across siblings. Greater discrepancies in siblings' conflict appraisals were related to more negative marital conflict and discrepancies in parent-child relationship quality, and were found in mixed-sex sibling dyads. Implications for future studies on factors that impact children's appraisals of conflict and in particular making use of sibling studies to examine shared environmental and individual influences on appraisals is highlighted. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Characteristics of individuals meeting criteria for new onset panic attacks following exposure to a typhoon

PubMed Central

Roberson-Nay, Roxann; Berenz, Erin C.; Acierno, Ron; Tran, Trinh Luong; Trung, Lam Tu; Tam, Nguyen Thanh; Tuan, Tran; Buoi, La Thi; Ha, Tran Thu; Thach, Tran Duc; Amstadter, Ananda B.

2013-01-01

The association between trauma exposure and panic attacks has received increased attention over the past decade, with mounting evidence suggesting an overlapping etiologic pathway. This study examined the incidence of new onset panic attacks in 775 Vietnamese individuals in the 2–3 months following Typhoon Xangsane. Pre-typhoon (Wave 1) and post-typhoon (Wave 2) assessments were conducted, allowing for consideration of factors occurring prior to the typhoon in addition to typhoon-relevant responding. Of the 775 participants, 11.6% (n=90) met criteria for lifetime panic attack pre-typhoon and 2.8% (n=22) met post-typhoon panic attack criteria. Individuals with pre-typhoon panic were significantly older and reported less education compared to the no-panic group. Individuals in both panic groups were more likely to screen positive on a Wave1 psychiatric screening measure, endorse greater typhoon exposure and prior traumatic event exposure and were significantly more likely to meet DSM-IV criteria for posttraumatic stress disorder (PTSD) and major depression (MDD) post-typhoon compared with persons reporting no history of panic attacks. Pre and post-typhoon panic exhibited similar patterns across variables and both panic conditions were associated with the development of PTSD and MDD, suggesting that persons experiencing panic attacks may represent a vulnerable population in need of early intervention services. PMID:23778303

Micro-proteomics with iterative data analysis: Proteome analysis in C. elegans at the single worm level.

PubMed

Bensaddek, Dalila; Narayan, Vikram; Nicolas, Armel; Murillo, Alejandro Brenes; Gartner, Anton; Kenyon, Cynthia J; Lamond, Angus I

2016-02-01

Proteomics studies typically analyze proteins at a population level, using extracts prepared from tens of thousands to millions of cells. The resulting measurements correspond to average values across the cell population and can mask considerable variation in protein expression and function between individual cells or organisms. Here, we report the development of micro-proteomics for the analysis of Caenorhabditis elegans, a eukaryote composed of 959 somatic cells and ∼1500 germ cells, measuring the worm proteome at a single organism level to a depth of ∼3000 proteins. This includes detection of proteins across a wide dynamic range of expression levels (>6 orders of magnitude), including many chromatin-associated factors involved in chromosome structure and gene regulation. We apply the micro-proteomics workflow to measure the global proteome response to heat-shock in individual nematodes. This shows variation between individual animals in the magnitude of proteome response following heat-shock, including variable induction of heat-shock proteins. The micro-proteomics pipeline thus facilitates the investigation of stochastic variation in protein expression between individuals within an isogenic population of C. elegans. All data described in this study are available online via the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd), an open access, searchable database resource. © 2015 The Authors. PROTEOMICS Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Breast cancer risks and risk prediction models.

PubMed

Engel, Christoph; Fischer, Christine

2015-02-01

BRCA1/2 mutation carriers have a considerably increased risk to develop breast and ovarian cancer. The personalized clinical management of carriers and other at-risk individuals depends on precise knowledge of the cancer risks. In this report, we give an overview of the present literature on empirical cancer risks, and we describe risk prediction models that are currently used for individual risk assessment in clinical practice. Cancer risks show large variability between studies. Breast cancer risks are at 40-87% for BRCA1 mutation carriers and 18-88% for BRCA2 mutation carriers. For ovarian cancer, the risk estimates are in the range of 22-65% for BRCA1 and 10-35% for BRCA2. The contralateral breast cancer risk is high (10-year risk after first cancer 27% for BRCA1 and 19% for BRCA2). Risk prediction models have been proposed to provide more individualized risk prediction, using additional knowledge on family history, mode of inheritance of major genes, and other genetic and non-genetic risk factors. User-friendly software tools have been developed that serve as basis for decision-making in family counseling units. In conclusion, further assessment of cancer risks and model validation is needed, ideally based on prospective cohort studies. To obtain such data, clinical management of carriers and other at-risk individuals should always be accompanied by standardized scientific documentation.

Individual reactions to viewing preferred video representations of the natural environment: A comparison of mental and physical reactions.

PubMed

Tsutsumi, Masae; Nogaki, Hiroshi; Shimizu, Yoshihisa; Stone, Teresa Elizabeth; Kobayashi, Toshio

2017-01-01

Globally, awareness of the vital link between health and the natural environment is growing. This pilot study, based on the idea of "forest bathing," or shinrin-yoku, the mindful use of all five senses to engage with nature in a natural environment, was initiated in order to determine whether stimulation by viewing an individual's preferred video of sea or forest had an effect on relaxation. The participants were 12 healthy men in their twenties and they were divided into two groups based on their preference for sea or forest scenery by using the Visual Analogue Scale. The participants watched 90 min DVDs of sea with natural sounds and forest with natural sounds while their heart rate variability and Bispectral Index System value were measured by using MemCalc/Tawara and a Bispectral Index System monitor. The participants were divided into two groups of six based on their preference for sea or forest scenery and each indicator was compared between them. Significant differences in a decrease in heart rate, increase in high frequency, and sustained arousal level were observed while viewing the preferred video. These results indicated that the viewing individual's preferred video of sea or forest had a relaxation effect. This study suggests that individual preferences should be taken into consideration for video relaxation therapy. © 2016 Japan Academy of Nursing Science.

The state of the art and future opportunities for using longitudinal n-of-1 methods in health behaviour research: a systematic literature overview.

PubMed

McDonald, Suzanne; Quinn, Francis; Vieira, Rute; O'Brien, Nicola; White, Martin; Johnston, Derek W; Sniehotta, Falko F

2017-12-01

n-of-1 studies test hypotheses within individuals based on repeated measurement of variables within the individual over time. Intra-individual effects may differ from those found in between-participant studies. Using examples from a systematic review of n-of-1 studies in health behaviour research, this article provides a state of the art overview of the use of n-of-1 methods, organised according to key methodological considerations related to n-of-1 design and analysis, and describes future challenges and opportunities. A comprehensive search strategy (PROSPERO:CRD42014007258) was used to identify articles published between 2000 and 2016, reporting observational or interventional n-of-1 studies with health behaviour outcomes. Thirty-nine articles were identified which reported on n-of-1 observational designs and a range of n-of-1 interventional designs, including AB, ABA, ABABA, alternating treatments, n-of-1 randomised controlled trial, multiple baseline and changing criterion designs. Behaviours measured included treatment adherence, physical activity, drug/alcohol use, sleep, smoking and eating behaviour. Descriptive, visual or statistical analyses were used. We identify scope and opportunities for using n-of-1 methods to answer key questions in health behaviour research. n-of-1 methods provide the tools needed to help advance theoretical knowledge and personalise/tailor health behaviour interventions to individuals.

Parcellating an individual subject's cortical and subcortical brain structures using snowball sampling of resting-state correlations.

PubMed

Wig, Gagan S; Laumann, Timothy O; Cohen, Alexander L; Power, Jonathan D; Nelson, Steven M; Glasser, Matthew F; Miezin, Francis M; Snyder, Abraham Z; Schlaggar, Bradley L; Petersen, Steven E

2014-08-01

We describe methods for parcellating an individual subject's cortical and subcortical brain structures using resting-state functional correlations (RSFCs). Inspired by approaches from social network analysis, we first describe the application of snowball sampling on RSFC data (RSFC-Snowballing) to identify the centers of cortical areas, subdivisions of subcortical nuclei, and the cerebellum. RSFC-Snowballing parcellation is then compared with parcellation derived from identifying locations where RSFC maps exhibit abrupt transitions (RSFC-Boundary Mapping). RSFC-Snowballing and RSFC-Boundary Mapping largely complement one another, but also provide unique parcellation information; together, the methods identify independent entities with distinct functional correlations across many cortical and subcortical locations in the brain. RSFC parcellation is relatively reliable within a subject scanned across multiple days, and while the locations of many area centers and boundaries appear to exhibit considerable overlap across subjects, there is also cross-subject variability-reinforcing the motivation to parcellate brains at the level of individuals. Finally, examination of a large meta-analysis of task-evoked functional magnetic resonance imaging data reveals that area centers defined by task-evoked activity exhibit correspondence with area centers defined by RSFC-Snowballing. This observation provides important evidence for the ability of RSFC to parcellate broad expanses of an individual's brain into functionally meaningful units. © The Author 2013. Published by Oxford University Press.

49 CFR 37.147 - Considerations during FTA review.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Considerations during FTA review. 37.147 Section 37.147 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Paratransit as a Complement to Fixed Route Service § 37.147 Considerations...

Shoulder pain and time dependent structure in wheelchair propulsion variability.

PubMed

Jayaraman, Chandrasekaran; Moon, Yaejin; Sosnoff, Jacob J

2016-07-01

Manual wheelchair propulsion places considerable repetitive mechanical strain on the upper limbs leading to shoulder injury and pain. While recent research indicates that the amount of variability in wheelchair propulsion and shoulder pain may be related. There has been minimal inquiry into the fluctuation over time (i.e. time-dependent structure) in wheelchair propulsion variability. Consequently the purpose of this investigation was to examine if the time-dependent structure in the wheelchair propulsion parameters are related to shoulder pain. 27 experienced wheelchair users manually propelled their own wheelchair fitted with a SMARTWheel on a roller at 1.1m/s for 3min. Time-dependent structure of cycle-to-cycle fluctuations in contact angle and inter push time interval was quantified using sample entropy (SampEn) and compared between the groups with/without shoulder pain using non-parametric statistics. Overall findings were, (1) variability observed in contact angle fluctuations during manual wheelchair propulsion is structured (Z=3.15;p<0.05), (2) individuals with shoulder pain exhibited higher SampEn magnitude for contact angle during wheelchair propulsion than those without pain (χ(2)(1)=6.12;p<0.05); and (3) SampEn of contact angle correlated significantly with self-reported shoulder pain (rs (WUSPI) =0.41;rs (VAS)=0.56;p<0.05). It was concluded that the time-dependent structure in wheelchair propulsion may provide novel information for tracking and monitoring shoulder pain. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Fear of pain, pain catastrophizing, and acute pain perception: relative prediction and timing of assessment.

PubMed

Hirsh, Adam T; George, Steven Z; Bialosky, Joel E; Robinson, Michael E

2008-09-01

Pain-related fear and catastrophizing are important variables of consideration in an individual's pain experience. Methodological limitations of previous studies limit strong conclusions regarding these relationships. In this follow-up study, we examined the relationships between fear of pain, pain catastrophizing, and experimental pain perception. One hundred healthy volunteers completed the Fear of Pain Questionnaire (FPQ-III), Pain Catastrophizing Scale (PCS), and Coping Strategies Questionnaire-Catastrophizing scale (CSQ-CAT) before undergoing the cold pressor test (CPT). The CSQ-CAT and PCS were completed again after the CPT, with participants instructed to complete these measures based on their experience during the procedure. Measures of pain threshold, tolerance, and intensity were collected and served as dependent variables in separate regression models. Sex, pain catastrophizing, and pain-related fear were included as predictor variables. Results of regression analyses indicated that after controlling for sex, pain-related fear was a consistently stronger predictor of pain in comparison to catastrophizing. These results were consistent when separate measures (CSQ-CAT vs PCS) and time points (pretask vs "in vivo") of catastrophizing were used. These findings largely corroborate those from our previous study and are suggestive of the absolute and relative importance of pain-related fear in the experimental pain experience. Although pain-related fear has received less attention in the experimental literature than pain catastrophizing, results of the current study are consistent with clinical reports highlighting this variable as an important aspect of the experience of pain.

Modeling hydrologic and geomorphic hazards across post-fire landscapes using a self-organizing map approach

USGS Publications Warehouse

Friedel, Michael J.

2011-01-01

Few studies attempt to model the range of possible post-fire hydrologic and geomorphic hazards because of the sparseness of data and the coupled, nonlinear, spatial, and temporal relationships among landscape variables. In this study, a type of unsupervised artificial neural network, called a self-organized map (SOM), is trained using data from 540 burned basins in the western United States. The sparsely populated data set includes variables from independent numerical landscape categories (climate, land surface form, geologic texture, and post-fire condition), independent landscape classes (bedrock geology and state), and dependent initiation processes (runoff, landslide, and runoff and landslide combination) and responses (debris flows, floods, and no events). Pattern analysis of the SOM-based component planes is used to identify and interpret relations among the variables. Application of the Davies-Bouldin criteria following k-means clustering of the SOM neurons identified eight conceptual regional models for focusing future research and empirical model development. A split-sample validation on 60 independent basins (not included in the training) indicates that simultaneous predictions of initiation process and response types are at least 78% accurate. As climate shifts from wet to dry conditions, forecasts across the burned landscape reveal a decreasing trend in the total number of debris flow, flood, and runoff events with considerable variability among individual basins. These findings suggest the SOM may be useful in forecasting real-time post-fire hazards, and long-term post-recovery processes and effects of climate change scenarios.

A methodology for modeling regional terrorism risk.

PubMed

Chatterjee, Samrat; Abkowitz, Mark D

2011-07-01

Over the past decade, terrorism risk has become a prominent consideration in protecting the well-being of individuals and organizations. More recently, there has been interest in not only quantifying terrorism risk, but also placing it in the context of an all-hazards environment in which consideration is given to accidents and natural hazards, as well as intentional acts. This article discusses the development of a regional terrorism risk assessment model designed for this purpose. The approach taken is to model terrorism risk as a dependent variable, expressed in expected annual monetary terms, as a function of attributes of population concentration and critical infrastructure. This allows for an assessment of regional terrorism risk in and of itself, as well as in relation to man-made accident and natural hazard risks, so that mitigation resources can be allocated in an effective manner. The adopted methodology incorporates elements of two terrorism risk modeling approaches (event-based models and risk indicators), producing results that can be utilized at various jurisdictional levels. The validity, strengths, and limitations of the model are discussed in the context of a case study application within the United States. © 2011 Society for Risk Analysis.

Clinical and Rehabilitative Management of Retinitis Pigmentosa: Up-to-Date

PubMed Central

Parmeggiani, Francesco; Sato, Giovanni; De Nadai, Katia; Romano, Mario R; Binotto, Andrea; Costagliola, Ciro

2011-01-01

The term retinitis pigmentosa (RP) indicates a heterogeneous group of genetic rare ocular diseases in which either rods or cones are prevalently damaged. RP represents the most common hereditary cause of blindness in people from 20 to 60 years old. In general, the different RP forms consist of progressive photo-receptorial neuro-degenerations, which are characterized by variable visual disabilities and considerable socio-sanitary burden. Sometimes, RP patients do not become visually impaired or legally blind until their 40-50 years of age and/or maintain a quite acceptable sight for all their life. Other individuals with RP become completely blind very early or in middle childhood. Although there is no treatment that can effectively cure RP, in some case-series the disease’s progression seems to be reducible by specific preventive approaches. In the most part of RP patients, the quality of vision can be considerably increased by means of nanometer-controlled filters. In the present review, the main aspects of the routine clinical and rehabilitative managements for RP patients are described, particularly focusing on the importance of specific referral Centers to practice a real multidisciplinary governance of these dramatic diseases. PMID:22131870

Consideration of Cosmetic Surgery As Part of Women's Benefit-Provisioning Mate Retention Strategy.

PubMed

Atari, Mohammad; Barbaro, Nicole; Sela, Yael; Shackelford, Todd K; Chegeni, Razieh

2017-01-01

Individuals perform mate retention behaviors to minimize the risk of partner infidelity and relationship dissolution. The current study investigates whether consideration of cosmetic surgery can be conceptualized as part of a broader strategy of mate retention for women, but not men. We hypothesized that women's consideration of cosmetic surgery would be positively associated with performance frequencies of Benefit-Provisioning and Cost-Inflicting mate retention behaviors. We recruited 203 individuals (54% women) in committed heterosexual relationships from Tehran, Iran. Results indicate a positive association between consideration of cosmetic surgery and Benefit-Provisioning mate retention behaviors for women, but not men. There was no association between consideration of cosmetic surgery and Cost-Inflicting mate retention behaviors. Women therefore may consider cosmetic surgery to improve their physical attractiveness as part of a Benefit-Provisioning strategy to retain a long-term mate. We discuss limitations of the study and highlight future directions for research from an evolutionary perspective.

Ascertaining serum levels of trace elements in melanoma patients using PIXE and HR-ICPMS

NASA Astrophysics Data System (ADS)

Bernardes, S.; Tabacniks, M. H.; Santos, I. D. A. O.; Oliveira, A. F.; Shie, J. N.; Sarkis, J. E. S.; Oliveira, T.

2014-01-01

Melanoma is a serious and deadly form of skin cancer. However, patients' chances of survival and recovery are considerably increased when it is diagnosed and treated in its early stages. In this study, trace element concentrations in serum samples from patients with melanoma were measured using PIXE (Proton Induced X-ray Emission) and HR-ICPMS (High-Resolution Inductively Coupled Plasma Mass Spectrometry), with the purpose of correlating these concentrations with the disease. Blood samples from 30 melanoma patients and 116 healthy donors were collected at São Paulo Hospital (protocol CEP 1036/08 UNIFESP). Relevant clinical information on the patients has also been included in the statistical analysis. Analysis of the control group showed different P and Mg concentrations in individuals above and below 40 years of age. P, S, Ca, Cu and Zn concentrations in healthy individuals differed according to gender, highlighting the necessity to include age and gender variables in the case-control analysis. There were also differences in K, S, Ca and Se concentrations between the control and melanoma groups.

Effects of multiple levels of social organization on survival and abundance.

PubMed

Ward, Eric J; Semmens, Brice X; Holmes, Elizabeth E; Balcomb Iii, Ken C

2011-04-01

Identifying how social organization shapes individual behavior, survival, and fecundity of animals that live in groups can inform conservation efforts and improve forecasts of population abundance, even when the mechanism responsible for group-level differences is unknown. We constructed a hierarchical Bayesian model to quantify the relative variability in survival rates among different levels of social organization (matrilines and pods) of an endangered population of killer whales (Orcinus orca). Individual killer whales often participate in group activities such as prey sharing and cooperative hunting. The estimated age-specific survival probabilities and survivorship curves differed considerably among pods and to a lesser extent among matrilines (within pods). Across all pods, males had lower life expectancy than females. Differences in survival between pods may be caused by a combination of factors that vary across the population's range, including reduced prey availability, contaminants in prey, and human activity. Our modeling approach could be applied to demographic rates for other species and for parameters other than survival, including reproduction, prey selection, movement, and detection probabilities. Conservation Biology ©2010 Society for Conservation Biology. No claim to original US government works.

Spatial Variation in Body Size and Wing Dimorphism Correlates With Environmental Conditions in the Grasshopper Dichroplus vittatus (Orthoptera: Acrididae).

PubMed

Rosetti, Natalia; Remis, Maria I

2018-06-06

Wing dimorphism occurs widely in insects and involves discontinuous variation in a wide variety of traits involved in fight and reproduction. In the current study, we analyzed the spatial pattern of wing dimorphism and intraspecific morphometric variation in nine natural populations of the grasshopper Dichroplus vittatus (Bruner; Orthoptera: Acrididae) in Argentina. Considerable body size differences among populations, between sexes and wing morphs were detected. As a general trend, females were larger than males and macropterous individuals showed increased thorax length over brachypterous which can be explained by the morphological requirements for the development of flight muscles in the thoracic cavity favoring dispersal. Moreover, when comparing wing morphs, a higher phenotypic variability was detected in macropterous females. The frequency of macropterous individuals showed negative correlation with longitude and positive with precipitations, indicating that the macropterous morph is more frequent in the humid eastern part of the studied area. Our results provide valuable about spatial variation of fully winged morph and revealed geographic areas in which the species would experience greater dispersal capacity.

Molecular classification of idiopathic pulmonary fibrosis: personalized medicine, genetics and biomarkers.

PubMed

Hambly, Nathan; Shimbori, Chiko; Kolb, Martin

2015-10-01

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fibrotic lung disease associated with high morbidity and poor survival. Characterized by substantial disease heterogeneity, the diagnostic considerations, clinical course and treatment response in individual patients can be variable. In the past decade, with the advent of high-throughput proteomic and genomic technologies, our understanding of the pathogenesis of IPF has greatly improved and has led to the recognition of novel treatment targets and numerous putative biomarkers. Molecular biomarkers with mechanistic plausibility are highly desired in IPF, where they have the potential to accelerate drug development, facilitate early detection in susceptible individuals, improve prognostic accuracy and inform treatment recommendations. Although the search for candidate biomarkers remains in its infancy, attractive targets such as MUC5B and MPP7 have already been validated in large cohorts and have demonstrated their potential to improve clinical predictors beyond that of routine clinical practices. The discovery and implementation of future biomarkers will face many challenges, but with strong collaborative efforts among scientists, clinicians and the industry the ultimate goal of personalized medicine may be realized. © 2015 Asian Pacific Society of Respirology.

Reproducibility of manual pressure force on provocation of the sacroiliac joint.

PubMed

Levin, U; Nilsson-Wikmar, L; Stenström, C H; Lundeberg, T

1998-01-01

Previous studies of pain-provocation sacroiliac (SI) joint tests have revealed conflicting results. The aim of the present study was to evaluate the intra- and inter-test reliability of pressure force applied during distraction test, compression test and pressure on the apex sacralis. Seventeen physiotherapists (PTs), median age 43 years and median clinical experience 11 years, all experienced in musculoskeletal evaluation and therapy, participated in the study. Each PT performed each test on the same healthy volunteer for 20 s, on three separate occasions, at intervals of one week using a specially constructed examination table which registered pressure force. The PTs were capable of maintaining a relatively constant pressure force for 20 s. The intra-test reliability was acceptable even though there were individual differences on different occasions between those PTs who used the SI joint tests often and those who seldom or never used them. The inter-test reliability was insufficient. The findings indicate the advantage of registering pressure force as a complement for standardized methods for pain-provoking tests and when learning provocation tests, since individual variability was considerable.

Social relations or social capital? Individual and community health effects of bonding social capital.

PubMed

Poortinga, Wouter

2006-07-01

Social capital has become one of the most popular topics in public health research in recent years. However, even after a decade of conceptual and empirical work on this subject, there is still considerable disagreement about whether bonding social capital is a collective resource that benefits communities or societies, or whether its health benefits are associated with people, their personal networks and support. Using data from the 2000 and 2002 Health Survey for England this study found that, in line with earlier research, personal levels of social support contribute to a better self-reported health status. The study also suggests that social capital is additionally important for people's health. In both datasets the aggregate social trust variable was significantly related to self-rated health before and after controlling for differences in socio-demographics and/or individual levels of social support. The results were corroborated in the second dataset with an alternative indicator of social capital. These results show that bonding social capital collectively contributes to people's self-rated health over and above the beneficial effects of personal social networks and support.

A reappraisal of adult thoracic and abdominal surface anatomy in Iranians in vivo using computed tomography.

PubMed

Pak, Neda; Patel, Shilpan G; Hashemi Taheri, Amir P; Hashemi, Fariba; Eftekhari Vaghefi, Raana; Naybandi Atashi, Sara; Mirjalili, S Ali

2016-03-01

Surface anatomy is a core component of human anatomy in clinical practice. It allows clinicians to assess patients accurately and quickly; however, recent studies have revealed variability among individuals and ethnicities. The aim of this study is to investigate possible variations in adult thoracic and abdominal surface anatomy landmarks in an Iranian population. This study used 100 thoracoabdominal CT scans (mean age: 47 ± 17 years, age range: 20-77 years, 47% females), noted the most common locations of clinically relevant surface markings, and analyzed correlations between these variables and age or gender. While many common surface markings in Iranians were consistent with the evidence-based literature, there were some differences. In relation to the corresponding segments of the vertebral column, the superior vena cava formation and the lower border of the pleura adjacent to the vertebral column and right kidney tended to be at higher levels in adult Iranians than a Caucasian population. There were also discrepancies between the Iranian population and commonly-referenced medical textbooks and recent evidence-based literature concerning the vertebral levels of the diaphragmatic openings of the esophagus, aorta, and inferior vena cava. This study emphasizes the need to consider evidence-based reappraisals of surface anatomy to guide clinical practice. Much of our current knowledge of surface anatomy is based on older studies of cadavers rather than living people, and does not take ethnic and individual variations into consideration. © 2015 Wiley Periodicals, Inc.

Soil Fertilization Leads to a Decline in Between-Samples Variability of Microbial Community δ13C Profiles in a Grassland Fertilization Experiment

PubMed Central

Veresoglou, Stavros D.; Thornton, Barry; Menexes, George; Mamolos, Andreas P.; Veresoglou, Demetrios S.

2012-01-01

Gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure the 13C/12C ratios of PLFAs at natural abundance levels from a temperate grassland nitrogen (N) and phosphorus (P) factorial fertilization experiment in northern Greece. In each plot two rhizosphere samples were derived centred around individual Agrostis capillaris and Prunella vulgaris plants. It was hypothesized that the isotopic signal of microbes that preferentially feed on recalcitrant litter such as fungi would be modified by fertilization more strongly than that of opportunistic microbes using labile C. Microbial community δ13C was affected by both P and N fertilization regime and plant species identity. However, we have been unable to detect significant nutrient effects on individual groups of microbes when analyzed separately in contrast to our original hypothesis. Intra-treatment variability, as evaluated from Hartley’s F max tests in the five first PCA components axes as well as the size of the convex hulls in PCA scoreplots and Mahalanobis distances, was considerably higher in the non-fertilized controls. Moreover, a significant relationship was established between the change in PLFA abundances and their respective changes in δ13C for the aggregate of samples and those simultaneously fertilized with N and P. We conclude that use of compound specific isotope analysis in the absence of labelling represents a valuable and overlooked tool in obtaining an insight of microbial community functioning. PMID:22962602

Sexual behaviors and sexual risk in a prospective cohort of HIV-positive men and women in New York City, 1994-2002: implications for prevention.

PubMed

Aidala, Angela A; Lee, Gunjeong; Garbers, Samantha; Chiasson, Mary Ann

2006-02-01

As an ever-increasing number of people infected with HIV are living longer, healthier lives, concerns about continued transmission are growing along with an awareness of the need to develop "prevention for positives." This study of HIV-positive adults in New York City is the first examination of patterns of sexual behavior in a large, representative cohort of HIV-infected individuals followed over an extended time period. A total of 968 HIV-positive adults were interviewed every 6-12 months between 1994 and 2002 and reported considerable variability in sexual behaviors over time. Many persons were not sexually active at all for months at a time; some continued to have multiple partners. Over one third of the cohort had one or more periods when they had engaged in unprotected sex with a partner who was HIV-negative or status unknown (unsafe sex) and one in five reported exchanging sex. Periods of unsafe sex alternated with periods of safer sex. Predictors of sexual risk varied by gender, and among men who had sex with men, and men sexually active with women only. Contextual factors such as partner relations, housing status, and receipt of HIV services were as important as individual attributes as predictors of unsafe sex and sex exchange. The variability observed in sexual risk behavior reported over time provides new insight into the importance of engaging persons living with HIV in ongoing prevention programs.

Determinants of Physiological and Perceived Physiological Stress Reactivity in Children and Adolescents

PubMed Central

Evans, Brittany E.; Greaves-Lord, Kirstin; Euser, Anja S.; Tulen, Joke H. M.; Franken, Ingmar H. A.; Huizink, Anja C.

2013-01-01

Aims Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related) of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. Method In a stratified sample of 363 children (7–12 years) and 344 adolescents (13–20 years) from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. Results Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. Conclusions As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness. PMID:23620785

Evidence-based pathology in its second decade: toward probabilistic cognitive computing.

PubMed

Marchevsky, Alberto M; Walts, Ann E; Wick, Mark R

2017-03-01

Evidence-based pathology advocates using a combination of best available data ("evidence") from the literature and personal experience for the diagnosis, estimation of prognosis, and assessment of other variables that impact individual patient care. Evidence-based pathology relies on systematic reviews of the literature, evaluation of the quality of evidence as categorized by evidence levels and statistical tools such as meta-analyses, estimates of probabilities and odds, and others. However, it is well known that previously "statistically significant" information usually does not accurately forecast the future for individual patients. There is great interest in "cognitive computing" in which "data mining" is combined with "predictive analytics" designed to forecast future events and estimate the strength of those predictions. This study demonstrates the use of IBM Watson Analytics software to evaluate and predict the prognosis of 101 patients with typical and atypical pulmonary carcinoid tumors in which Ki-67 indices have been determined. The results obtained with this system are compared with those previously reported using "routine" statistical software and the help of a professional statistician. IBM Watson Analytics interactively provides statistical results that are comparable to those obtained with routine statistical tools but much more rapidly, with considerably less effort and with interactive graphics that are intuitively easy to apply. It also enables analysis of natural language variables and yields detailed survival predictions for patient subgroups selected by the user. Potential applications of this tool and basic concepts of cognitive computing are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Gray matter correlates of creative potential: A latent variable voxel-based morphometry study

PubMed Central

Jauk, Emanuel; Neubauer, Aljoscha C.; Dunst, Beate; Fink, Andreas; Benedek, Mathias

2015-01-01

There is increasing research interest in the structural and functional brain correlates underlying creative potential. Recent investigations found that interindividual differences in creative potential relate to volumetric differences in brain regions belonging to the default mode network, such as the precuneus. Yet, the complex interplay between creative potential, intelligence, and personality traits and their respective neural bases is still under debate. We investigated regional gray matter volume (rGMV) differences that can be associated with creative potential in a heterogeneous sample of N = 135 individuals using voxel-based morphometry (VBM). By means of latent variable modeling and consideration of recent psychometric advancements in creativity research, we sought to disentangle the effects of ideational originality and fluency as two independent indicators of creative potential. Intelligence and openness to experience were considered as common covariates of creative potential. The results confirmed and extended previous research: rGMV in the precuneus was associated with ideational originality, but not with ideational fluency. In addition, we found ideational originality to be correlated with rGMV in the caudate nucleus. The results indicate that the ability to produce original ideas is tied to default-mode as well as dopaminergic structures. These structural brain correlates of ideational originality were apparent throughout the whole range of intellectual ability and thus not moderated by intelligence. In contrast, structural correlates of ideational fluency, a quantitative marker of creative potential, were observed only in lower intelligent individuals in the cuneus/lingual gyrus. PMID:25676914

Failure mode and effects analysis: an empirical comparison of failure mode scoring procedures.

PubMed

Ashley, Laura; Armitage, Gerry

2010-12-01

To empirically compare 2 different commonly used failure mode and effects analysis (FMEA) scoring procedures with respect to their resultant failure mode scores and prioritization: a mathematical procedure, where scores are assigned independently by FMEA team members and averaged, and a consensus procedure, where scores are agreed on by the FMEA team via discussion. A multidisciplinary team undertook a Healthcare FMEA of chemotherapy administration. This included mapping the chemotherapy process, identifying and scoring failure modes (potential errors) for each process step, and generating remedial strategies to counteract them. Failure modes were scored using both an independent mathematical procedure and a team consensus procedure. Almost three-fifths of the 30 failure modes generated were scored differently by the 2 procedures, and for just more than one-third of cases, the score discrepancy was substantial. Using the Healthcare FMEA prioritization cutoff score, almost twice as many failure modes were prioritized by the consensus procedure than by the mathematical procedure. This is the first study to empirically demonstrate that different FMEA scoring procedures can score and prioritize failure modes differently. It found considerable variability in individual team members' opinions on scores, which highlights the subjective and qualitative nature of failure mode scoring. A consensus scoring procedure may be most appropriate for FMEA as it allows variability in individuals' scores and rationales to become apparent and to be discussed and resolved by the team. It may also yield team learning and communication benefits unlikely to result from a mathematical procedure.

Attitudine Linguistica e Memoria. Alcune Considerazioni sul MLAT. (Modern Language Aptitude Test). (Linguistic Aptitude and Memory. Some Considerations on the MLAT).

ERIC Educational Resources Information Center

Sorace, Antonella

1982-01-01

Examines the Modern Language Aptitude Test and identifies as the lowest common denominator in three of its four parts an individual's short-term Memory capability. Concludes that this test cannot indicate an individual's linguistic aptitude because it does not take into consideration the role of two key aspects of language learning: long-term…

40 CFR 194.52 - Consideration of exposure pathways.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Consideration of exposure pathways... Individual and Ground-Water Protection Requirements § 194.52 Consideration of exposure pathways. In compliance assessments that analyze compliance with § 191.15 of this chapter, all potential exposure pathways...

40 CFR 194.52 - Consideration of exposure pathways.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Consideration of exposure pathways... Individual and Ground-Water Protection Requirements § 194.52 Consideration of exposure pathways. In compliance assessments that analyze compliance with § 191.15 of this chapter, all potential exposure pathways...

40 CFR 194.52 - Consideration of exposure pathways.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Consideration of exposure pathways... Individual and Ground-Water Protection Requirements § 194.52 Consideration of exposure pathways. In compliance assessments that analyze compliance with § 191.15 of this chapter, all potential exposure pathways...

40 CFR 194.52 - Consideration of exposure pathways.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Consideration of exposure pathways. 194... Individual and Ground-Water Protection Requirements § 194.52 Consideration of exposure pathways. In compliance assessments that analyze compliance with § 191.15 of this chapter, all potential exposure pathways...

40 CFR 194.52 - Consideration of exposure pathways.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Consideration of exposure pathways... Individual and Ground-Water Protection Requirements § 194.52 Consideration of exposure pathways. In compliance assessments that analyze compliance with § 191.15 of this chapter, all potential exposure pathways...

Individual Variables, Literacy History, and ESL Progress Among Kurdish and Bosnian Immigrants.

ERIC Educational Resources Information Center

Gardner, Sheena; And Others

1996-01-01

Examines the relationship between individual variables and the progress in English as a Second Language (ESL) among Kurdish and Bosnian adult immigrants living in Canada. Findings reveal significant correlations between the dependent variables of oral and written progress and the independent variables of literacy level, years of schooling, and…

Individual and contextual factors related to binge drinking among adolescents in Spain: a multilevel approach.

PubMed

Teixidó-Compañó, Ester; Sordo, Luis; Bosque-Prous, Marina; Puigcorbé, Susanna; Barrio, Gregorio; Brugal, M Teresa; Belza, María José J; Espelt, Albert

2018-01-15

The aim of this study was to estimate the prevalence of binge drinking by regions in Spain and assess the effect of individual and contextual factors related to this drinking pattern in adolescents. A cross-sectional study was performed with data from the 2014 Spanish School Survey on Drug Use (ESTUDES) in students aged 14-18 years (N = 34,259). The outcome was binge drinking in adolescents during the last 30 days. Individual independent variables were socioeconomic variables and variables related to access to alcohol and its availability. Contextual variables consisted of adult alcohol consumption, public policies on alcohol, and socioeconomic factors. Multilevel Poisson regression models with robust variance were estimated, obtaining prevalence ratios (PR) and their 95% confidence intervals.  The results showed that the prevalence of youth binge drinking by region of residence was similar for both sexes (r = 0.72). At the individual level, binge drinking was mainly associated with the perception of easy access to alcohol (PR: 1.38; 95% CI: 1.23-1.55), consumption in open areas [(PR: 3.82; 95% CI: 3.44-4.24) < once a month and (PR: 6.57; 95% CI: 5.85-7.37) ≥ once a month], at least one parent allowing alcohol consumption (PR: 1.42; 95% CI: 1.37-1.47), and receiving >30 euros weekly (PR :1.51; 95% CI: 1.37-1.67). Contextual variables were not associated with youth binge drinking when individual variables were considered. In conclusion, youth binge drinking was associated with individual variables related to high alcohol accessibility and availability, regardless of contextual variables. These variables explained the variability in binge drinking among Spanish regions.

The Science of the Individual

ERIC Educational Resources Information Center

Rose, L. Todd; Rouhani, Parisa; Fischer, Kurt W.

2013-01-01

Our goal is to establish a science of the individual, grounded in dynamic systems, and focused on the analysis of individual variability. Our argument is that individuals behave, learn, and develop in distinctive ways, showing patterns of variability that are not captured by models based on statistical averages. As such, any meaningful attempt to…

On FIA Variables For Ecological Use

Treesearch

David C. Chojnacky

2001-01-01

The Forest Inventory and Analysis (FIA) program collects or calculates over 300 variables for its national network of permanent forest plots. However, considerable ecological analysis can be done with only a few key variables. Two examples--Mexican spotted owl habitat in New Mexico and down deadwood in Maine--are used to illustrate the potential of FIA data for...

Improvements and important considerations for the 5-choice serial reaction time task-An effective measurement of visual attention in rats.

PubMed

Bhandari, Jayant; Daya, Ritesh; Mishra, Ram K

2016-09-01

The 5-choice serial reaction time task (5-CSRTT) is an automated operant conditioning task that measures rodent attention. The task allows the measurement of several parameters such as response accuracy, speed of processing, motivation, and impulsivity. The task has been widely used to investigate attentional processes in rodents for attention deficit and hyperactivity disorder and has expanded to other illnesses such as Alzheimer's disease, depression, and schizophrenia. The 5-CSRTT is accompanied with two significant caveats: a time intensive training period and largely varied individual rat capability to learn and perform the task. Here we provide a regimented acquisition protocol to enhance training for the 5-CSRTT and discuss important considerations for researchers using the 5-CSRTT. We offer guidelines to ensure that inferences on performance in the 5-CSRTT are in fact a result of experimental manipulation rather than training differences, or individual animal capability. According to our findings only rats that have been trained successfully within a limited time frame should be used for the remainder of the study. Currently the 5-CSRTT employs a training period of variable duration and procedure, and its inferences on attention must overcome heterogeneous innate animal differences. The 5-CSRTT offers valuable and valid insights on various rodent attentional processes and their translation to the underpinnings of illnesses such as schizophrenia. The recommendations made here provide important criteria to ensure inferences made from this task are in fact relevant to the attentional processes being measured. Copyright © 2016 Elsevier B.V. All rights reserved.

[Professional burnout among university and high school teachers--comparative study].

PubMed

Swietochowski, Waldemar

2011-01-01

Professional burnout is a set of negative emotional and behavioral symptoms, observed in workers of widely understood human service occupations, including teachers. In spite of the considerable number of studies of burnout in teachers, a few of them concern university teachers. The aim of the article was to estimate the degree of burning threat in this professional group and to analyze individual determinants and dynamics of burning out in academic teachers. Gender, age, personality traits and temperament traits were given the status of main factors in the study. The role of the perceived social support was also analyzed. 97 academic workers of three state universities (University, Medical University and Technical University) in Łódź took part in the study; 100 teachers of high schools formed a comparative group. MBI General Survey was applied to measure dependent variables (burnout and its three components: Emotional Exhaustion, Cinicism and Professional Efficacy). The level of factors was measured with standard psychological tests: NEO-FFI and FCZ-KT. The Scale of Perceived Social Support was also applied. The results show considerably lower threat of the burning out syndrome in university than in high school teachers. Among individual factors only two temperament traits (emotional reactivity and perseveration) and one personality trait (extroversion) seem to be important determinants of professional burnout. The perceived social support does not prevent the progress of burnout syndrome. Based on the obtained results several practical conclusions were formulated. They refer mainly to preventive training for beginners in teaching and changes in the organization of academic teachers' work.

Brain-Behavior Participant Similarity Networks Among Youth and Emerging Adults with Schizophrenia Spectrum, Autism Spectrum, or Bipolar Disorder and Matched Controls.

PubMed

Stefanik, Laura; Erdman, Lauren; Ameis, Stephanie H; Foussias, George; Mulsant, Benoit H; Behdinan, Tina; Goldenberg, Anna; O'Donnell, Lauren J; Voineskos, Aristotle N

2018-04-01

There is considerable heterogeneity in social cognitive and neurocognitive performance among people with schizophrenia spectrum disorders (SSD), autism spectrum disorders (ASD), bipolar disorder (BD), and healthy individuals. This study used Similarity Network Fusion (SNF), a novel data-driven approach, to identify participant similarity networks based on relationships among demographic, brain imaging, and behavioral data. T1-weighted and diffusion-weighted magnetic resonance images were obtained for 174 adolescents and young adults (aged 16-35 years) with an SSD (n=51), an ASD without intellectual disability (n=38), euthymic BD (n=34), and healthy controls (n=51). A battery of social cognitive and neurocognitive tasks were administered. Data integration, cluster determination, and biological group formation were then obtained using SNF. We identified four new groups of individuals, each with distinct neural circuit-cognitive profiles. The most influential variables driving the formation of the new groups were robustly reliable across embedded resampling techniques. The data-driven groups showed considerably greater differentiation on key social and neurocognitive circuit nodes than groups generated by diagnostic analyses or dimensional social cognitive analyses. The data-driven groups were validated through functional outcome and brain network property measures not included in the SNF model. Cutting across diagnostic boundaries, our approach can effectively identify new groups of people based on a profile of neuroimaging and behavioral data. Our findings bring us closer to disease subtyping that can be leveraged toward the targeting of specific neural circuitry among participant subgroups to ameliorate social cognitive and neurocognitive deficits.

Why the Indian subcontinent holds the key to global tiger recovery.

PubMed

Mondol, Samrat; Karanth, K Ullas; Ramakrishnan, Uma

2009-08-01

With only approximately 3,000 wild individuals surviving restricted to just 7% of their historical range, tigers are now a globally threatened species. Therefore, conservation efforts must prioritize regions that harbor more tigers, as well try to capture most of the remaining genetic variation and habitat diversity. Only such prioritization based on demographic, genetic, and ecological considerations can ensure species recovery and retention of evolutionary flexibility in the face of ongoing global changes. Although scientific understanding of ecological and demographic aspects of extant wild tiger populations has improved recently, little is known about their genetic composition and variability. We sampled 73 individual tigers from 28 reserves spread across a diversity of habitats in the Indian subcontinent to obtain 1,263 bp of mitochondrial DNA and 10 microsatellite loci. Our analyses reveals that Indian tigers retain more than half of the extant genetic diversity in the species. Coalescent simulations attribute this high genetic diversity to a historically large population size of about 58,200 tigers for peninsular India south of the Gangetic plains. Furthermore, our analyses indicate a precipitous, possibly human-induced population crash approximately 200 years ago in India, which is in concordance with historical records. Our results suggest that only 1.7% (with an upper limit of 13% and a lower limit of 0.2%) of tiger numbers in historical times remain now. In the global conservation context our results suggest that, based on genetic, demographic, and ecological considerations, the Indian subcontinent holds the key to global survival and recovery of wild tigers.

An analysis of dental development in Pleistocene Homo using skeletal growth and chronological age.

PubMed

Šešelj, Maja

2017-07-01

This study takes a new approach to interpreting dental development in Pleistocene Homo in comparison with recent modern humans. As rates of dental development and skeletal growth are correlated given age in modern humans, using age and skeletal growth in tandem yields more accurate dental development estimates. Here, I apply these models to fossil Homo to obtain more individualized predictions and interpretations of their dental development relative to recent modern humans. Proportional odds logistic regression models based on three recent modern human samples (N = 181) were used to predict permanent mandibular tooth development scores in five Pleistocene subadults: Homo erectus/ergaster, Neanderthals, and anatomically modern humans (AMHs). Explanatory variables include a skeletal growth indicator (i.e., diaphyseal femoral length), and chronological age. AMHs Lagar Velho 1 and Qafzeh 10 share delayed incisor development, but exhibit considerable idiosyncratic variation within and across tooth types, relative to each other and to the reference samples. Neanderthals Dederiyeh 1 and Le Moustier 1 exhibit delayed incisor coupled with advanced molar development, but differences are reduced when femoral diaphysis length is considered. Dental development in KNM-WT 15,000 Homo erectus/ergaster, while advanced for his age, almost exactly matches the predictions once femoral length is included in the models. This study provides a new interpretation of dental development in KNM-WT 15000 as primarily reflecting his faster rates of skeletal growth. While the two AMH specimens exhibit considerable individual variation, the Neanderthals exhibit delayed incisor development early and advanced molar development later in ontogeny. © 2017 Wiley Periodicals, Inc.

A hierarchical model for spatial capture-recapture data

USGS Publications Warehouse

Royle, J. Andrew; Young, K.V.

2008-01-01

Estimating density is a fundamental objective of many animal population studies. Application of methods for estimating population size from ostensibly closed populations is widespread, but ineffective for estimating absolute density because most populations are subject to short-term movements or so-called temporary emigration. This phenomenon invalidates the resulting estimates because the effective sample area is unknown. A number of methods involving the adjustment of estimates based on heuristic considerations are in widespread use. In this paper, a hierarchical model of spatially indexed capture recapture data is proposed for sampling based on area searches of spatial sample units subject to uniform sampling intensity. The hierarchical model contains explicit models for the distribution of individuals and their movements, in addition to an observation model that is conditional on the location of individuals during sampling. Bayesian analysis of the hierarchical model is achieved by the use of data augmentation, which allows for a straightforward implementation in the freely available software WinBUGS. We present results of a simulation study that was carried out to evaluate the operating characteristics of the Bayesian estimator under variable densities and movement patterns of individuals. An application of the model is presented for survey data on the flat-tailed horned lizard (Phrynosoma mcallii) in Arizona, USA.

Breaking the routine: individual Cory's shearwaters shift winter destinations between hemispheres and across ocean basins

PubMed Central

Dias, Maria P.; Granadeiro, José P.; Phillips, Richard A.; Alonso, Hany; Catry, Paulo

2011-01-01

There is growing evidence that migratory species are particularly vulnerable to rapid environmental changes arising from human activity. Species are expected to vary in their capacity to respond to these changes: long-distance migrants and those lacking variability in migratory traits are probably at considerable disadvantage. The few studies that have assessed the degree of plasticity in behaviour of marine animals suggest that fidelity to non-breeding destinations is usually high. In the present study, we evaluated individual flexibility in migration strategy of a highly pelagic seabird, the Cory's shearwater Calonectris diomedea. Geolocation data from 72 different migrations, including 14 birds that were tracked for more than one non-breeding season, showed a remarkable capacity to change winter destinations between years. Although some birds exhibited high site fidelity, others shifted from the South to North Atlantic, from the western to eastern South Atlantic, and from the Atlantic to Indian Ocean. Individuals also showed flexibility in stopover behaviour and migratory schedule. Although their K-selected life-history strategy has the disadvantage that the chances of microevolution are slight if circumstances alter rapidly, these results suggest that Cory's shearwaters may be in a better position than many other long-distance migrants to face the consequences of a changing environment. PMID:21106591

The sex lives of parasites: investigating the mating system and mechanisms of sexual selection of the human pathogen Schistosoma mansoni.

PubMed

Steinauer, Michelle L

2009-08-01

The mating systems of internal parasites are inherently difficult to investigate although they have important implications for the evolutionary biology of the species, disease epidemiology, and are important considerations for control measures. Using parentage analyses, three topics concerning the mating biology of Schistosoma mansoni were investigated: the number of mates per adult male and female, variance in reproductive success among individuals, and the potential role for sexual selection on male body size and also mate choice for genetically dissimilar individuals. Results indicated that schistosomes were mostly monogamous, and evidence of only one mate change occurred over a period of 5-6 weeks. One male was polygynous and contained two females in its gynecophoral canal although offspring were only detected for one of the females. Even though they were primarily monogamous and the sex ratio near even, reproductive success was highly variable, indicating a potential role for sexual selection. Male body size was positively related to reproductive success, consistent with sexual selection via male-male competition and female choice for large males. However, relatedness of pairs was not associated with their reproductive success. Finally, genetically identical individuals differed significantly in their reproductive output and identical males in their body size, indicating important partner and environmental effects on these traits.

The Importance of Patient-Specific Factors for Hepatic Drug Response and Toxicity

PubMed Central

Lauschke, Volker M.; Ingelman-Sundberg, Magnus

2016-01-01

Responses to drugs and pharmacological treatments differ considerably between individuals. Importantly, only 50%–75% of patients have been shown to react adequately to pharmacological interventions, whereas the others experience either a lack of efficacy or suffer from adverse events. The liver is of central importance in the metabolism of most drugs. Because of this exposed status, hepatotoxicity is amongst the most common adverse drug reactions and hepatic liabilities are the most prevalent reason for the termination of development programs of novel drug candidates. In recent years, more and more factors were unveiled that shape hepatic drug responses and thus underlie the observed inter-individual variability. In this review, we provide a comprehensive overview of different principle mechanisms of drug hepatotoxicity and illustrate how patient-specific factors, such as genetic, physiological and environmental factors, can shape drug responses. Furthermore, we highlight other parameters, such as concomitantly prescribed medications or liver diseases and how they modulate drug toxicity, pharmacokinetics and dynamics. Finally, we discuss recent progress in the field of in vitro toxicity models and evaluate their utility in reflecting patient-specific factors to study inter-individual differences in drug response and toxicity, as this understanding is necessary to pave the way for a patient-adjusted medicine. PMID:27754327

Persistence of physical activity in middle age: a nonlinear dynamic panel approach.

PubMed

Kumagai, Narimasa; Ogura, Seiritsu

2014-09-01

No prior investigation has considered the effects of state dependence and unobserved heterogeneity on the relationship between regular physical activity (RPA) and latent health stock (LHS). Accounting for state dependence corrects the possible overestimation of the impact of socioeconomic factors. We estimated the degree of the state dependence of RPA and LHS among middle-aged Japanese workers. The 5 years' longitudinal data used in this study were taken from the Longitudinal Survey of Middle and Elderly Persons. Individual heterogeneity was found for both RPA and LHS, and the dynamic random-effects probit model provided the best specification. A smoking habit, low educational attainment, longer work hours, and longer commuting time had negative effects on RPA participation. RPA had positive effects on LHS, taking into consideration the possibility of confounding with other lifestyle variables. The degree of state dependence of LHS was positive and significant. Increasing the intensity of RPA had positive effects on LHS and caused individuals with RPA to exhibit greater persistence of LHS compared to individuals without RPA. This result implies that policy interventions that promote RPA, such as smoking cessation, have lasting consequences. We concluded that smoking cessation is an important health policy to increase both the participation in RPA and LHS.

Ergonomic Considerations for the Human Environment: Color Treatment, Lighting, and Furniture Selection.

ERIC Educational Resources Information Center

Robertson, Michelle M.

1992-01-01

Discusses ergonomic design considerations for library media centers. Specific design variables, including temperature and humidity, noise, illumination, color, and windows are discussed; and computer workstation design requirements are presented that address furniture and keyboard design, monitor and display features, software issues, and…

Cultural and Cognitive Considerations in the Prevention of American Indian Adolescent Suicide.

ERIC Educational Resources Information Center

La Framboise, Teresa D.; Big Foot, Delores Subia

1988-01-01

Describes cultural considerations associated with American Indian adolescents coping within a transactional, cognitive-phenomenological framework. Discusses select cultural values and beliefs of American Indians associated with death in terms of person variables and situational demand characteristics that interplay in coping process. Suggests…

Further evidence of self-medication: personality factors influencing drug choice in substance use disorders.

PubMed

McKernan, Lindsey Colman; Nash, Michael R; Gottdiener, William H; Anderson, Scott E; Lambert, Warren E; Carr, Erika R

2015-06-01

According to Khantzian's (2003) self-medication hypothesis (SMH), substance dependence is a compensatory means to modulate affects and self-soothe in response to distressing psychological states. Khantzian asserts: (1) Drugs become addicting because they have the power to alleviate, remove, or change human psychological suffering, and (2) There is a considerable degree of specificity in a person's choice of drugs because of unique psychological and physiological effects. The SMH has received criticism for its variable empirical support, particularly in terms of the drug-specificity aspect of Khantzian's hypothesis. We posit that previous empirical examinations of the SMH have been compromised by methodological limitations. Also, more recent findings supporting the SMH have yet to be replicated. Addressing previous limitations to the research, this project tested this theory in a treatment sample of treatment-seeking individuals with substance dependence (N = 304), using more heterogeneous, personality-driven measures that are theory-congruent. Using an algorithm based on medical records, individuals were reliably classified as being addicted to a depressant, stimulant, or opiate by two independent raters. Theory-based a priori predictions were that the three groups would exhibit differences in personality characteristics and emotional-regulation strategies. Specifically, our hypotheses entailed that when compared against each other: (1) Individuals with a central nervous system (CNS) depressant as drug of choice (DOC) will exhibit defenses of repression, over-controlling anger, and emotional inhibition to avoid acknowledging their depression; (2) Individuals with an opiate as DOC will exhibit higher levels of aggression, hostility, depression, and trauma, greater deficits in ego functioning, and externalizing/antisocial behavior connected to their use; and (3) Individuals with a stimulant as DOC will experience anhedonia, paranoia, have a propensity to mania, and display lower levels of emotional inhibition. MANOVAs were used to test three hypotheses regarding drug group differences on the personality variables that were in keeping with the SMH. The MANOVAs for Hypothesis I (Depressant group) and Hypothesis II (Opiate group) were statistically significant. Findings partially support the SMH, particularly in its characterization of personality functioning in those addicted to depressants and opiates.

Personality features in ultra-high risk for psychosis: a comparative study with schizophrenia and control subjects using the Temperament and Character Inventory-Revised (TCI-R).

PubMed

Fresán, Ana; León-Ortiz, Pablo; Robles-García, Rebeca; Azcárraga, Mariana; Guizar, Diana; Reyes-Madrigal, Francisco; Tovilla-Zárate, Carlos Alfonso; de la Fuente-Sandoval, Camilo

2015-02-01

Several variables have been identified as risk factors for conversion to overt psychosis in ultra-high risk for psychosis (UHR) individuals. Although almost two-thirds of them do not experience a transition to psychosis, they still exhibit functional disabilities. Other subjective developmental features may be useful for a more precise identification of individuals at UHR. Avoidant behaviors are consistently reported in schizophrenia and in UHR individuals and may be the reflection of a pattern of personality. Thus, personality features in UHR individuals deserves further research. The objective of the present study was to compare temperament and character dimensions between UHR individuals, patients with schizophrenia and healthy controls. One hundred participants (25 UHR individuals, 25 schizophrenia patients and 50 control subjects) where evaluated with the Temperament and Character Inventory-Revised (TCI-R). Univariate ANOVAs followed by Bonferroni tests were used. UHR individuals and schizophrenia patients exhibited higher levels of Harm Avoidance (HA) when compared to control subjects. For HA1 Anticipatory worry vs Uninhibited optimism and HA4 Fatigability & asthenia, UHR and schizophrenia groups showed similar scores and both groups were higher compared to control subjects. With respect to Cooperativeness (CO), UHR and schizophrenia reported lower scores than control subjects, in particular CO2 Empathy vs Social disinterest and CO3 Helpfulness vs unhelpfulness. This study replicates and extends the consideration of HA as a psychopathological related endophenotype and gives us further information of the possible role of personality features in the expression of some of the social dysfunctions observed both in prodromal subjects and schizophrenia patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

International variation in ethics committee requirements: comparisons across five Westernised nations

PubMed Central

Goodyear-Smith, Felicity; Lobb, Brenda; Davies, Graham; Nachson, Israel; Seelau, Sheila M

2002-01-01

Background Ethics committees typically apply the common principles of autonomy, nonmaleficence, beneficence and justice to research proposals but with variable weighting and interpretation. This paper reports a comparison of ethical requirements in an international cross-cultural study and discusses their implications. Discussion The study was run concurrently in New Zealand, UK, Israel, Canada and USA and involved testing hypotheses about believability of testimonies regarding alleged child sexual abuse. Ethics committee requirements to conduct this study ranged from nil in Israel to considerable amendments designed to minimise participant harm in New Zealand. Assessment of minimal risk is a complex and unreliable estimation further compounded by insufficient information on probabilities of particular individuals suffering harm. Estimating potential benefits/ risks ratio and protecting participants' autonomy similarly are not straightforward exercises. Summary Safeguarding moral/humane principles should be balanced with promotion of ethical research which does not impede research posing minimal risk to participants. In ensuring that ethical standards are met and research has scientific merit, ethics committees have obligations to participants (to meet their rights and protect them from harm); to society (to ensure good quality research is conducted); and to researchers (to treat their proposals with just consideration and respect). To facilitate meeting all these obligations, the preferable focus should be promotion of ethical research, rather than the prevention of unethical research, which inevitably results in the impediment of researchers from doing their work. How the ethical principles should be applied and balanced requires further consideration. PMID:11964190

Using Multigroup-Multiphase Latent State-Trait Models to Study Treatment-Induced Changes in Intra-Individual State Variability: An Application to Smokers' Affect.

PubMed

Geiser, Christian; Griffin, Daniel; Shiffman, Saul

2016-01-01

Sometimes, researchers are interested in whether an intervention, experimental manipulation, or other treatment causes changes in intra-individual state variability. The authors show how multigroup-multiphase latent state-trait (MG-MP-LST) models can be used to examine treatment effects with regard to both mean differences and differences in state variability. The approach is illustrated based on a randomized controlled trial in which N = 338 smokers were randomly assigned to nicotine replacement therapy (NRT) vs. placebo prior to quitting smoking. We found that post quitting, smokers in both the NRT and placebo group had significantly reduced intra-individual affect state variability with respect to the affect items calm and content relative to the pre-quitting phase. This reduction in state variability did not differ between the NRT and placebo groups, indicating that quitting smoking may lead to a stabilization of individuals' affect states regardless of whether or not individuals receive NRT.

Using Multigroup-Multiphase Latent State-Trait Models to Study Treatment-Induced Changes in Intra-Individual State Variability: An Application to Smokers' Affect

PubMed Central

Geiser, Christian; Griffin, Daniel; Shiffman, Saul

2016-01-01

Sometimes, researchers are interested in whether an intervention, experimental manipulation, or other treatment causes changes in intra-individual state variability. The authors show how multigroup-multiphase latent state-trait (MG-MP-LST) models can be used to examine treatment effects with regard to both mean differences and differences in state variability. The approach is illustrated based on a randomized controlled trial in which N = 338 smokers were randomly assigned to nicotine replacement therapy (NRT) vs. placebo prior to quitting smoking. We found that post quitting, smokers in both the NRT and placebo group had significantly reduced intra-individual affect state variability with respect to the affect items calm and content relative to the pre-quitting phase. This reduction in state variability did not differ between the NRT and placebo groups, indicating that quitting smoking may lead to a stabilization of individuals' affect states regardless of whether or not individuals receive NRT. PMID:27499744

In vivo measurements of the influence of the skin on cerebral oxygenation changes measured with near-infrared spectrophotometry (NIRS)

NASA Astrophysics Data System (ADS)

Klaessens, John H. G. M.; van Os, Sandra H. G.; Hopman, Jeroen C. W.; Liem, K. D.; van de Bor, Margot; Thijssen, Johan M.

2004-07-01

Goal: To investigate the influence of skin on the accuracy and precision of regional cerebral oxygenation measurements using CW-NIRS and to reduce the inter individual variability of NIRS measurements by normalization with data from an extra wavelength. Method: Three piglets (7.8-9.3 kg) were anesthetized, paralyzed and mechanically ventilated. Receiving optodes were placed over the left and right hemisphere (C3, C4 EEG placement code) and one emitting optode on Cz position (optode distance=1.8cm). Optical densities (OD) were measured for 3 wavelengths (767, 850, 905 nm) (OXYMON) during stable normoxic, mild and deep hypoxemic conditions (SaO2=100%, 80% and 60%) of one minute in each region. This was repeated 3 times: all optodes with skin (condition 1); one receiving optode directly on the skull (2); emitting and also receiving optode on the skull (3). The absolute cO2Hb, cHHb, ctHb concentrations (μmol/L) were calculated from the OD's and changes with respect to the SaO2=100% condition were estimated. Because ODs varied over a large range, the light intensity was externally attenuated to adapt to the range of the spectrophotometer. The data were then corrected for these attenuation effects and for pathlength changes caused by skin removal using the OD at the independent wavelength (λ=975nm). Results: Removal of the skin resulted in an increase of the absorption values (average 0.25 OD in condition 2 and 0.42 OD in condition 3 with respect to condition 1). The change from normoxic to medium, and to deep hypoxic conditions produced a decrease of cO2Hb (-15, and -29 μmol/L, respectively), an increase in cHHb (+16, and +35 μmol/L) and in ctHb (+1, and +5 μmol/L). Total skin removal yielded an extra change in cO2Hb (-5, -1 μmol/L), cHHb (+8, +9 μmol/L), and ctHb (+3, +8 μmol /L). The coefficient of variability of the absolute concentration changes was considerably decreased by the normalization of densities by the density obtained at 795 nm. Conclusion: Skin and subcutaneous layers influence the regional oxygenation measurements but the estimated concentration changes are dominated by changes of the oxygenation levels in the brain. Inter individual variability can be considerably reduced by the normalization.

Some Considerations Necessary for a Viable Theory of Human Memory.

ERIC Educational Resources Information Center

Sietsema, Douglas J.

Empirical research is reviewed in the area of cognitive psychology pertaining to models of human memory. Research evidence and theoretical considerations are combined to develop guidelines for future theory development related to the human memory. The following theoretical constructs and variables are discussed: (1) storage versus process…

Individual differences and time-varying features of modular brain architecture.

PubMed

Liao, Xuhong; Cao, Miao; Xia, Mingrui; He, Yong

2017-05-15

Recent studies have suggested that human brain functional networks are topologically organized into functionally specialized but inter-connected modules to facilitate efficient information processing and highly flexible cognitive function. However, these studies have mainly focused on group-level network modularity analyses using "static" functional connectivity approaches. How these extraordinary modular brain structures vary across individuals and spontaneously reconfigure over time remain largely unknown. Here, we employed multiband resting-state functional MRI data (N=105) from the Human Connectome Project and a graph-based modularity analysis to systematically investigate individual variability and dynamic properties in modular brain networks. We showed that the modular structures of brain networks dramatically vary across individuals, with higher modular variability primarily in the association cortex (e.g., fronto-parietal and attention systems) and lower variability in the primary systems. Moreover, brain regions spontaneously changed their module affiliations on a temporal scale of seconds, which cannot be simply attributable to head motion and sampling error. Interestingly, the spatial pattern of intra-subject dynamic modular variability largely overlapped with that of inter-subject modular variability, both of which were highly reproducible across repeated scanning sessions. Finally, the regions with remarkable individual/temporal modular variability were closely associated with network connectors and the number of cognitive components, suggesting a potential contribution to information integration and flexible cognitive function. Collectively, our findings highlight individual modular variability and the notable dynamic characteristics in large-scale brain networks, which enhance our understanding of the neural substrates underlying individual differences in a variety of cognition and behaviors. Copyright © 2017 Elsevier Inc. All rights reserved.

The Role of Individual Differences and Situational Variables in the Use of Workplace Sexual Identity Management Strategies.

PubMed

Reed, Louren; Leuty, Melanie E

2016-07-01

Examination of individual difference variables have been largely ignored within research on the use of workplace sexual identity management strategies. The current study examined personality traits (extraversion, openness, and neuroticism), facets of sexual identity development (identity confusion, internalized heterosexism), and situational variables (e.g., perceptions of workplace climate and heterosexism) in explaining the use of management strategies, as well as possible interactions between individual and situational factors. Perceptions of the workplace climate toward lesbian and gay individuals significantly related to the use each of the management strategies, and Internalized Heterosexism was found to significantly predict the use of the Explicitly Out strategy. Most interactions between individual difference and situational variables were not supported, with the exception of an interaction between workplace heterosexism and internalized homophobia in explaining the use of the Explicitly Out strategy.

Lunar sample analysis. [X-ray photoemission and Auger spectroscopy of lunar glass

NASA Technical Reports Server (NTRS)

Housley, R. M.; Grant, R. W.; Cirlin, E. H.

1979-01-01

The surface composition of two samples from the highly shocked, glass-coated lunar basalt (12054) and from four glass-coated fragments from the 1-2 mm (14161) fines were examined by X-ray photoemission spectroscopy to determine whether the agglutination process itself is responsible for the difference between their surface and bulk compositions. Auger electron spectroscopy of glass balls from the 15425 and 74001 fines were analyzed to understand the nature, extent, and behavior of volatile phases associated with lunar volcanism. Initial results indicate that (1) volatiles, in the outer few atomic layers sampled, vary considerably from ball to ball; (2) variability over the surface of individual balls is smaller; (3) the dominant volatiles on the balls are S and Zn; and (4) other volatiles commonly observed are P, Cl, and K.

Informative, Compare and Contrast, and Persuasive Essay Composing of Fifth and Seventh Graders: Not All Essay Writing Is the Same

PubMed Central

Davidson, Matt; Berninger, Virginia

2015-01-01

Typically developing writers in fifth (n = 110, M = 10 years 8 months) or seventh (n = 97, M = 12 years 7 months) grade wrote informative, compare and contrast, and persuasive essays for which the content was held constant—two mountains with a history of volcanic eruption. Relevant background knowledge was provided by reading text and showing colorful illustrations to the students before writing each genre. Results showed considerable variability between genre pairs within and across individual writers in content quality, organization quality, and length. Results, which support multiple expository genres, are consistent with prior research showing multiple genres (narrative vs. expository or even within narrative). Results are discussed in reference to the importance of assessing multiple genres in inferring composing expertise as emphasized by Olinghouse and colleagues. PMID:27418715

Final Syllable Lengthening (FSL) in infant vocalizations.

PubMed

Nathani, Suneeti; Oller, D Kimbrough; Cobo-Lewis, Alan B

2003-02-01

Final Syllable Lengthening (FSL) has been extensively examined in infant vocalizations in order to determine whether its basis is biological or learned. Findings suggest there may be a U-shaped developmental trajectory for FSL. The present study sought to verify this pattern and to determine whether vocal maturity and deafness influence FSL. Eight normally hearing infants, aged 0;3 to 1;0, and eight deaf infants, aged 0;8 to 4;0, were examined at three levels of prelinguistic vocal development: precanonical, canonical, and postcanonical. FSL was found at all three levels suggesting a biological basis for this phenomenon. Individual variability was, however, considerable. Reduction in the magnitude of FSL across the three sessions provided some support for a downward trend for FSL in infancy. Findings further indicated that auditory deprivation can significantly affect temporal aspects of infant speech production.

Isolation of microsatellite loci for Rhodiola alsia (Crassulaceae), an important ethno-medicinal herb endemic to the Qinghai-Tibetan plateau.

PubMed

Zhang, F Q; Lei, S Y; Gao, Q B; Khan, G; Xing, R; Yang, H L; Chen, S L

2015-05-18

Rhodiola alsia, which has been used widely in traditional Chinese medicine for a considerable time, grows on moist habitats at high altitude near the snow line. Microsatellite loci were developed for R. alsia to investigate its population genetics. In total, 17 polymorphic microsatellites were developed based on ESTs from the Illumina HiSeq(TM) 2000 platform. The microsatellite loci were checked for variability using 80 individuals of R. alsia sampled from four locations on the Qinghai-Tibet Plateau. The total number of alleles per locus ranged from 10 to 20, and the observed heterozygosity ranged from 0.000 to 1.000. The null allele frequency ranged from 0.000 to 0.324. These microsatellites are expected to be helpful in future studies of population genetics in R. alsia and related species.

Experience Modulates the Reproductive Response to Heat Stress in C. elegans via Multiple Physiological Processes

PubMed Central

Gouvêa, Devin Y.; Aprison, Erin Z.; Ruvinsky, Ilya

2015-01-01

Natural environments are considerably more variable than laboratory settings and often involve transient exposure to stressful conditions. To fully understand how organisms have evolved to respond to any given stress, prior experience must therefore be considered. We investigated the effects of individual and ancestral experience on C. elegans reproduction. We documented ways in which cultivation at 15°C or 25°C affects developmental time, lifetime fecundity, and reproductive performance after severe heat stress that exceeds the fertile range of the organism but is compatible with survival and future fecundity. We found that experience modulates multiple aspects of reproductive physiology, including the male and female germ lines and the interaction between them. These responses vary in their environmental sensitivity, suggesting the existence of complex mechanisms for coping with unpredictable and stressful environments. PMID:26713620

Future Directions in Sleep and Developmental Psychopathology.

PubMed

Meltzer, Lisa J

2017-01-01

It is critical for psychologists to gain a better understanding about the intersection between sleep and developmental psychopathology. However, while many strive to answer the question of whether sleep causes developmental psychopathology, or vice versa, ultimately the relationship between sleep and developmental psychopathology is complex and dynamic. This article considers future directions in the field of clinical child and adolescent psychology that go beyond this mechanistic question, highlighting areas important to address for clinicians and researchers who strive to better understand how best to serve children and adolescents with developmental psychopathology. Questions are presented about what is normal in terms of sleep across development, the role of individual variability in terms of sleep needs and vulnerability to sleep loss, and how sleep may serve as a risk or resilience factor for developmental psychopathology, concluding with considerations for interventions.

X-Ray Variability of BL Lac Objects

NASA Astrophysics Data System (ADS)

McHardy, Ian

I present an overview of the X-ray temporal and spectral variability of BL Lacs on both short and long timescales. The previously observed behaviour of short (~days) flares superimposed on a relatively steady `quiescent' level is still broadly correct. However, for the brighter BL Lacs, the well sampled lightcurves from the RXTE ASM show that the `quiescent' level also varies considerably on timescales of ~100 days in a manner similar to that seen in Optically Violently Variable Quasars (OVVs) such as 3C279 and 3C273. Possible reasons for this behaviour are discussed. For the large majority of BL Lacs the soft and medium energy X-ray bands are dominated by synchrotron emission and, unlike the case of OVVs, the emission mechanism is not in doubt. Most interest then centres on the structure of the emitting region, and the electron acceleration processes, particularly during outbursts. That structure, and the acceleration processes, can be investigated by consideration of the spectral variability during flares, which is not simple. I review the observations of spectral variability and consider the evidence for and against homogeneous models. I also briefly compare the X-ray spectral variability of BL Lacs with that of OVVs such as 3C273.

Small-scale temporal and spatial variability in the abundance of plastic pellets on sandy beaches: Methodological considerations for estimating the input of microplastics.

PubMed

Moreira, Fabiana Tavares; Prantoni, Alessandro Lívio; Martini, Bruno; de Abreu, Michelle Alves; Stoiev, Sérgio Biato; Turra, Alexander

2016-01-15

Microplastics such as pellets have been reported for many years on sandy beaches around the globe. Nevertheless, high variability is observed in their estimates and distribution patterns across the beach environment are still to be unravelled. Here, we investigate the small-scale temporal and spatial variability in the abundance of pellets in the intertidal zone of a sandy beach and evaluate factors that can increase the variability in data sets. The abundance of pellets was estimated during twelve consecutive tidal cycles, identifying the position of the high tide between cycles and sampling drift-lines across the intertidal zone. We demonstrate that beach dynamic processes such as the overlap of strandlines and artefacts of the methods can increase the small-scale variability. The results obtained are discussed in terms of the methodological considerations needed to understand the distribution of pellets in the beach environment, with special implications for studies focused on patterns of input. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

ERIC Educational Resources Information Center

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

2007-01-01

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

Plasticity of circadian activity and body temperature rhythms in golden spiny mice.

PubMed

Cohen, Rotem; Smale, Laura; Kronfeld-Schor, Noga

2009-04-01

Most animals can be categorized as nocturnal, diurnal, or crepuscular. However, rhythms can be quite plastic in some species and vary from one individual to another within a species. In the golden spiny mouse (Acomys russatus), a variety of rhythm patterns have been seen, and these patterns can change considerably as animals are transferred from the field into the laboratory. We previously suggested that these animals may have a circadian time-keeping system that is fundamentally nocturnal and that diurnal patterns seen in their natural habitat reflect mechanisms operating outside of the basic circadian time-keeping system (i.e., masking). In the current study, we further characterized plasticity evident in the daily rhythms of golden spiny mice by measuring effects of lighting conditions and access to a running wheel on rhythms in general activity (GA) and body temperature (Tb). Before the wheel was introduced, most animals were active mainly during the night, though there was considerable inter-individual variability and patterns were quite plastic. The introduction of the wheel caused an increase in the level of nighttime activity and Tb in most individuals. The periods of the rhythms in constant darkness (DD) were very similar, and even slightly longer in this study (24.1+/-0.2 h) than in an earlier one in which animals had not been provided with running wheels. We found no correlation between the distance animals ran in their wheels and the period of their rhythms in DD. Re-entrainment after phase delays of the LD cycle occurred more rapidly in the presence than absence of the running wheel. The characteristics of the rhythms of golden spiny mice seen in this study may be the product of natural selection favoring plasticity of the circadian system, perhaps reflecting what can happen during an evolutionary transition as animals move from a nocturnal to a diurnal niche.

Individual and contextual factors of influence on adherence to antiretrovirals among people attending public clinics in Rio de Janeiro, Brazil

PubMed Central

2013-01-01

Background There are inconsistencies in the determinants of adherence to antiretrovirals (ARVs) across settings as well as a lack of studies that take into consideration factors beyond the individual level. This makes it necessary to examine factors holistically in multiple settings and populations while taking into consideration the particularities of each context, in order to understand the patterns of ARV adherence. This research explored ARV adherence and individual, relational and environmental-structural factors. Methods A cross-sectional survey was conducted from August 2008 through July 2009 among participants currently on ARVs recruited from 6 public health clinics, selected to maximize diversity in terms of caseload and location, representing the range of clinics within Rio de Janeiro city, Brazil. Multivariate logistic regression analysis was used to assess the association between our multilevel factors with ARV adherence among participants with complete cases (n = 632). Results Eighty-four percent of respondents reported adherence to all of their ARV doses in the last 4 days. Of the socio-demographic variables, those who had one child were positively associated with adherence (AOR 2.29 CI [1.33-3.94]). On the relational level, those with high social support (AOR 2.85 CI [1.50-5.41]) were positively associated with adherence to ARVs. On the environmental-structural level, we found gender was significant with women negatively associated with adherence to ARVs (AOR 0.58 CI [0.38-0.88]) while those with a high asset index (AOR 2.47 CI [1.79-3.40]) were positively associated with adherence to ARVs. Conclusions This research highlights the importance of examining the multiple levels of influence on ARV adherence. Intervention research in lower and middle-income settings should address and evaluate the impact of attending to both gender and economic inequalities to improve ARV adherence, as well as relational areas such as the provision of social support. PMID:23758780

Meta-regression analysis of commensal and pathogenic Escherichia coli survival in soil and water.

PubMed

Franz, Eelco; Schijven, Jack; de Roda Husman, Ana Maria; Blaak, Hetty

2014-06-17

The extent to which pathogenic and commensal E. coli (respectively PEC and CEC) can survive, and which factors predominantly determine the rate of decline, are crucial issues from a public health point of view. The goal of this study was to provide a quantitative summary of the variability in E. coli survival in soil and water over a broad range of individual studies and to identify the most important sources of variability. To that end, a meta-regression analysis on available literature data was conducted. The considerable variation in reported decline rates indicated that the persistence of E. coli is not easily predictable. The meta-analysis demonstrated that for soil and water, the type of experiment (laboratory or field), the matrix subtype (type of water and soil), and temperature were the main factors included in the regression analysis. A higher average decline rate in soil of PEC compared with CEC was observed. The regression models explained at best 57% of the variation in decline rate in soil and 41% of the variation in decline rate in water. This indicates that additional factors, not included in the current meta-regression analysis, are of importance but rarely reported. More complete reporting of experimental conditions may allow future inference on the global effects of these variables on the decline rate of E. coli.

Airborne Laser Altimetry Mapping of the Greenland Ice Sheet: Application to Mass Balance Assessment

NASA Technical Reports Server (NTRS)

Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Wright, W.; Yungel, J.

2000-01-01

In 1998 and '99, the Arctic Ice Mapping (AIM) program completed resurveys of lines occupied 5 years earlier revealing elevation changes of the Greenland ice sheet and identifying areas of significant thinning, thickening and balance. In planning these surveys, consideration had to be given to the spatial constraints associated with aircraft operation, the spatial nature of ice sheet behavior, and limited resources, as well as temporal issues, such as seasonal and interannual variability in the context of measurement accuracy. This paper examines the extent to which the sampling and survey strategy is valid for drawing conclusions on the current state of balance of the Greenland ice sheet. The surveys covered the entire ice sheet with an average distance of 21.4 km between each location on the ice sheet and the nearest flight line. For most of the ice sheet, the elevation changes show relatively little spatial variability, and their magnitudes are significantly smaller than the observed elevation change signal. As a result, we conclude that the density of the sampling and the accuracy of the measurements are sufficient to draw meaningful conclusions on the state of balance of the entire ice sheet over the five-year survey period. Outlet glaciers, however, show far more spatial and temporal variability, and each of the major ones is likely to require individual surveys in order to determine its balance.

Solar Influences on El Nino/Southern Oscillation Dynamics Over the Last Millennium

NASA Astrophysics Data System (ADS)

Stevenson, S.; Capotondi, A.; Fasullo, J.; Otto-Bliesner, B. L.

2017-12-01

The El Niño/Southern Oscillation (ENSO) exhibits considerable differences between the evolution of individual El Nino and La Nina events (`ENSO diversity'), with significant implications for impacts studies. However, the degree to which external forcing may affect ENSO diversity is not well understood, due to both internal variability and potentially compensatory contributions from multiple forcings. The Community Earth System Model Last Millennium Ensemble (CESM LME) provides an ideal testbed for studying the sensitivity of twentieth century ENSO to forced climate changes, as it contains many realizations of the 850-2005 period with differing combinations of forcings. Metrics of ENSO amplitude and diversity are compared across LME simulations, and although forced changes to ENSO amplitude are generally small, forced changes to diversity are often detectable. Anthropogenic changes to greenhouse gas and ozone/aerosol emissions modify the persistence of Eastern and Central Pacific El Nino events, through shifts in the upwelling and zonal advective feedbacks; these influences generally cancel one another over the twentieth century. Natural forcings are generally small over the 20th century, but when epochs of high/low solar irradiance are compared, distinct shifts in the development and termination of El Nino events can be observed. This indicates that solar variability can indeed have a significant role to play in setting the characteristics of tropical Pacific climate variability. Implications for configuring and evaluating projections of future climate change will be discussed.

Impacts of climate variability and human colonization on the vegetation of the Galápagos Islands.

PubMed

Restrepo, Alejandra; Colinvaux, Paul; Bush, Mark; Correa-Metrio, Alexander; Conroy, Jessica; Gardener, Mark R; Jaramillo, Patricia; Steinitz-Kannan, Miriam; Overpeck, Jonathan

2012-08-01

A high-resolution (2-9 year sampling interval) fossil pollen record from the Galápagos Islands, which spans the last 2690 years, reveals considerable ecosystem stability. Vegetation changes associated with independently derived histories of El Niño Southern Oscillation variability provided evidence of shifts in the relative abundance of individual species rather than immigration or extinction. Droughts associated with the Medieval Climate Anomaly induced rapid ecological change that was followed by a reversion to the previous state. The paleoecological data suggested nonneutral responses to climatic forcing in this ecosystem prior to the period of human influence. Human impacts on the islands are evident in the record. A marked decline in long-term codominants of the pollen record, Alternanthera and Acalypha, produced a flora without modern analogue before 1930. Intensified animal husbandry after ca. 1930 may have induced the local extinction of Acalypha and Alternanthera. Reductions in populations of grazing animals in the 1970s and 1980s did not result in the return of the native flora, but in invasions by exotic species. After ca. 1970 the trajectory of habitat change accelerated, continuously moving the ecosystem away from the observed range of variability in the previous 2690 years toward a novel ecosystem. The last 40 years of the record also suggest unprecedented transport of lowland pollen to the uplands, consistent with intensified convection and warmer wet seasons.

Interobserver variability in identification of breast tumors in MRI and its implications for prognostic biomarkers and radiogenomics

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

Saha, Ashirbani, E-mail: as698@duke.edu; Grimm, La

Purpose: To assess the interobserver variability of readers when outlining breast tumors in MRI, study the reasons behind the variability, and quantify the effect of the variability on algorithmic imaging features extracted from breast MRI. Methods: Four readers annotated breast tumors from the MRI examinations of 50 patients from one institution using a bounding box to indicate a tumor. All of the annotated tumors were biopsy proven cancers. The similarity of bounding boxes was analyzed using Dice coefficients. An automatic tumor segmentation algorithm was used to segment tumors from the readers’ annotations. The segmented tumors were then compared between readersmore » using Dice coefficients as the similarity metric. Cases showing high interobserver variability (average Dice coefficient <0.8) after segmentation were analyzed by a panel of radiologists to identify the reasons causing the low level of agreement. Furthermore, an imaging feature, quantifying tumor and breast tissue enhancement dynamics, was extracted from each segmented tumor for a patient. Pearson’s correlation coefficients were computed between the features for each pair of readers to assess the effect of the annotation on the feature values. Finally, the authors quantified the extent of variation in feature values caused by each of the individual reasons for low agreement. Results: The average agreement between readers in terms of the overlap (Dice coefficient) of the bounding box was 0.60. Automatic segmentation of tumor improved the average Dice coefficient for 92% of the cases to the average value of 0.77. The mean agreement between readers expressed by the correlation coefficient for the imaging feature was 0.96. Conclusions: There is a moderate variability between readers when identifying the rectangular outline of breast tumors on MRI. This variability is alleviated by the automatic segmentation of the tumors. Furthermore, the moderate interobserver variability in terms of the bounding box does not translate into a considerable variability in terms of assessment of enhancement dynamics. The authors propose some additional ways to further reduce the interobserver variability.« less

Not accounting for interindividual variability can mask habitat selection patterns: a case study on black bears.

PubMed

Lesmerises, Rémi; St-Laurent, Martin-Hugues

2017-11-01

Habitat selection studies conducted at the population scale commonly aim to describe general patterns that could improve our understanding of the limiting factors in species-habitat relationships. Researchers often consider interindividual variation in selection patterns to control for its effects and avoid pseudoreplication by using mixed-effect models that include individuals as random factors. Here, we highlight common pitfalls and possible misinterpretations of this strategy by describing habitat selection of 21 black bears Ursus americanus. We used Bayesian mixed-effect models and compared results obtained when using random intercept (i.e., population level) versus calculating individual coefficients for each independent variable (i.e., individual level). We then related interindividual variability to individual characteristics (i.e., age, sex, reproductive status, body condition) in a multivariate analysis. The assumption of comparable behavior among individuals was verified only in 40% of the cases in our seasonal best models. Indeed, we found strong and opposite responses among sampled bears and individual coefficients were linked to individual characteristics. For some covariates, contrasted responses canceled each other out at the population level. In other cases, interindividual variability was concealed by the composition of our sample, with the majority of the bears (e.g., old individuals and bears in good physical condition) driving the population response (e.g., selection of young forest cuts). Our results stress the need to consider interindividual variability to avoid misinterpretation and uninformative results, especially for a flexible and opportunistic species. This study helps to identify some ecological drivers of interindividual variability in bear habitat selection patterns.

Variable ecological conditions promote male helping by changing banded mongoose group composition.

PubMed

Marshall, Harry H; Sanderson, Jennifer L; Mwanghuya, Francis; Businge, Robert; Kyabulima, Solomon; Hares, Michelle C; Inzani, Emma; Kalema-Zikusoka, Gladys; Mwesige, Kenneth; Thompson, Faye J; Vitikainen, Emma I K; Cant, Michael A

2016-01-01

Ecological conditions are expected to have an important influence on individuals' investment in cooperative care. However, the nature of their effects is unclear: both favorable and unfavorable conditions have been found to promote helping behavior. Recent studies provide a possible explanation for these conflicting results by suggesting that increased ecological variability, rather than changes in mean conditions, promote cooperative care. However, no study has tested whether increased ecological variability promotes individual-level helping behavior or the mechanisms involved. We test this hypothesis in a long-term study population of the cooperatively breeding banded mongoose, Mungos mungo , using 14 years of behavioral and meteorological data to explore how the mean and variability of ecological conditions influence individual behavior, body condition, and survival. Female body condition was more sensitive to changes in rainfall leading to poorer female survival and pronounced male-biased group compositions after periods of high rainfall variability. After such periods, older males invested more in helping behavior, potentially because they had fewer mating opportunities. These results provide the first empirical evidence for increased individual helping effort in more variable ecological conditions and suggest this arises because of individual differences in the effect of ecological conditions on body condition and survival, and the knock-on effect on social group composition. Individual differences in sensitivity to environmental variability, and the impacts this has on the internal structure and composition of animal groups, can exert a strong influence on the evolution and maintenance of social behaviors, such as cooperative care.

Automatic Evaluations and Exercising: Systematic Review and Implications for Future Research.

PubMed

Schinkoeth, Michaela; Antoniewicz, Franziska

2017-01-01

The general purpose of this systematic review was to summarize, structure and evaluate the findings on automatic evaluations of exercising. Studies were eligible for inclusion if they reported measuring automatic evaluations of exercising with an implicit measure and assessed some kind of exercise variable. Fourteen nonexperimental and six experimental studies (out of a total N = 1,928) were identified and rated by two independent reviewers. The main study characteristics were extracted and the grade of evidence for each study evaluated. First, results revealed a large heterogeneity in the applied measures to assess automatic evaluations of exercising and the exercise variables. Generally, small to large-sized significant relations between automatic evaluations of exercising and exercise variables were identified in the vast majority of studies. The review offers a systematization of the various examined exercise variables and prompts to differentiate more carefully between actually observed exercise behavior (proximal exercise indicator) and associated physiological or psychological variables (distal exercise indicator). Second, a lack of transparent reported reflections on the differing theoretical basis leading to the use of specific implicit measures was observed. Implicit measures should be applied purposefully, taking into consideration the individual advantages or disadvantages of the measures. Third, 12 studies were rated as providing first-grade evidence (lowest grade of evidence), five represent second-grade and three were rated as third-grade evidence. There is a dramatic lack of experimental studies, which are essential for illustrating the cause-effect relation between automatic evaluations of exercising and exercise and investigating under which conditions automatic evaluations of exercising influence behavior. Conclusions about the necessity of exercise interventions targeted at the alteration of automatic evaluations of exercising should therefore not be drawn too hastily.